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Sample records for spin texture similar

  1. Spin Transport in Ferromagnetic and Antiferromagnetic Textures

    KAUST Repository

    Akosa, Collins A.

    2016-12-07

    In this dissertation, we provide an accurate description of spin transport in magnetic textures and in particular, we investigate in detail, the nature of spin torque and magnetic damping in such systems. Indeed, as will be further discussed in this thesis, the current-driven velocity of magnetic textures is related to the ratio between the so-called non-adiabatic torque and magnetic damping. Uncovering the physics underlying these phenomena can lead to the optimal design of magnetic systems with improved efficiency. We identified three interesting classes of systems which have attracted enormous research interest (i) Magnetic textures in systems with broken inversion symmetry: We investigate the nature of magnetic damping in non-centrosymmetric ferromagnets. Based on phenomenological and microscopic derivations, we show that the magnetic damping becomes chiral, i.e. depends on the chirality of the magnetic texture. (ii) Ferromagnetic domain walls, skyrmions and vortices: We address the physics of spin transport in sharp disordered magnetic domain walls and vortex cores. We demonstrate that upon spin-independent scattering, the non-adiabatic torque can be significantly enhanced. Such an enhancement is large for vortex cores compared to transverse domain walls. We also show that the topological spin currents owing in these structures dramatically enhances the non-adiabaticity, an effect unique to non-trivial topological textures (iii) Antiferromagnetic skyrmions: We extend this study to antiferromagnetic skyrmions and show that such an enhanced topological torque also exist in these systems. Even more interestingly, while such a non-adiabatic torque inuences the undesirable transverse velocity of ferromagnetic skyrmions, in antiferromagnetic skyrmions, the topological non-adiabatic torque directly determines the longitudinal velocity. As a consequence, scaling down the antiferromagnetic skyrmion results in a much more efficient spin torque.

  2. Spin Hall effect-driven spin torque in magnetic textures

    KAUST Repository

    Manchon, Aurelien

    2011-07-13

    Current-induced spin torque and magnetization dynamics in the presence of spin Hall effect in magnetic textures is studied theoretically. The local deviation of the charge current gives rise to a current-induced spin torque of the form (1 - ΒM) × [(u 0 + αH u 0 M) ∇] M, where u0 is the direction of the injected current, H is the Hall angle and is the non-adiabaticity parameter due to spin relaxation. Since αH and ×can have a comparable order of magnitude, we show that this torque can significantly modify the current-induced dynamics of both transverse and vortex walls. © 2011 American Institute of Physics.

  3. Magnetization dynamics of imprinted non-collinear spin textures

    Energy Technology Data Exchange (ETDEWEB)

    Streubel, Robert, E-mail: r.streubel@ifw-dresden.de; Kopte, Martin; Makarov, Denys, E-mail: d.makarov@ifw-dresden.de [Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden (Germany); Fischer, Peter [Center for X-Ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Physics Department, UC Santa Cruz, Santa Cruz, California 95064 (United States); Schmidt, Oliver G. [Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden (Germany); Material Systems for Nanoelectronics, Chemnitz University of Technology, 09107 Chemnitz (Germany)

    2015-09-14

    We study the magnetization dynamics of non-collinear spin textures realized via imprint of the magnetic vortex state in soft permalloy into magnetically hard out-of-plane magnetized Co/Pd nanopatterned heterostructures. Tuning the interlayer exchange coupling between soft- and hard-magnetic subsystems provides means to tailor the magnetic state in the Co/Pd stack from being vortex- to donut-like with different core sizes. While the imprinted vortex spin texture leads to the dynamics similar to the one observed for vortices in permalloy disks, the donut-like state causes the appearance of two gyrofrequencies characteristic of the early and later stages of the magnetization dynamics. The dynamics are described using the Thiele equation supported by the full scale micromagnetic simulations by taking into account an enlarged core size of the donut states compared to magnetic vortices.

  4. Nanopatterning spin-textures: A route to reconfigurable magnonics

    Directory of Open Access Journals (Sweden)

    E. Albisetti

    2017-05-01

    Full Text Available Magnonics is envisioned to enable highly efficient data transport and processing, by exploiting propagating perturbations in the spin-texture of magnetic materials. Despite the demonstrations of a plethora of proof-of-principle devices, the efficient excitation, transport and manipulation of spin-waves at the nanoscale is still an open challenge. Recently, we demonstrated that the spin-wave excitation and propagation can be controlled by nanopatterning reconfigurable spin-textures in a continuous exchange biased ferromagnetic film. Here, we show that by patterning 90° stripe-shaped magnetic domains, we spatially modulate the spin-wave excitation in a continuous film, and that by applying an external magnetic field we can reversibly “switch-off” the spin-wave excitation. This opens the way to the use of nanopatterned spin-textures, such as domains and domain walls, for exciting and manipulating magnons in reconfigurable nanocircuits.

  5. Unconventional spin texture of a topologically nontrivial semimetal Sb(110)

    DEFF Research Database (Denmark)

    Strózecka, A.; Eiguren, A.; Bianchi, Marco

    2012-01-01

    of Sb(110). The existence of the unconventional spin texture is corroborated by the investigations of the electron scattering on this surface. The charge interference patterns formed around single scattering impurities, imaged by scanning tunneling microscopy, reveal the absence of direct backscattering......The surfaces of antimony are characterized by the presence of spin-split states within the projected bulk band gap and the Fermi contour is thus expected to exhibit a spin texture. Using spin-resolved density functional theory calculations, we determine the spin polarization of the surface bands...

  6. Reversible spin texture in ferroelectric Hf O2

    Science.gov (United States)

    Tao, L. L.; Paudel, Tula R.; Kovalev, Alexey A.; Tsymbal, Evgeny Y.

    2017-06-01

    Spin-orbit coupling effects occurring in noncentrosymmetric materials are known to be responsible for nontrivial spin configurations and a number of emergent physical phenomena. Ferroelectric materials may be especially interesting in this regard due to reversible spontaneous polarization making possible a nonvolatile electrical control of the spin degrees of freedom. Here, we explore a technologically relevant oxide material, Hf O2 , which has been shown to exhibit robust ferroelectricity in a noncentrosymmetric orthorhombic phase. Using theoretical modelling based on density-functional theory, we investigate the spin-dependent electronic structure of the ferroelectric Hf O2 and demonstrate the appearance of chiral spin textures driven by spin-orbit coupling. We analyze these spin configurations in terms of the Rashba and Dresselhaus effects within the k .p Hamiltonian model and find that the Rashba-type spin texture dominates around the valence-band maximum, while the Dresselhaus-type spin texture prevails around the conduction band minimum. The latter is characterized by a very large Dresselhaus constant λD= 0.578 eV Å, which allows using this material as a tunnel barrier to produce tunneling anomalous and spin Hall effects that are reversible by ferroelectric polarization.

  7. Self-similarity of contact line depinning from textured surfaces.

    Science.gov (United States)

    Paxson, Adam T; Varanasi, Kripa K

    2013-01-01

    The mobility of drops on surfaces is important in many biological and industrial processes, but the phenomena governing their adhesion, which is dictated by the morphology of the three-phase contact line, remain unclear. Here we describe a technique for measuring the dynamic behaviour of the three-phase contact line at micron length scales using environmental scanning electron microscopy. We examine a superhydrophobic surface on which a drop's adhesion is governed by capillary bridges at the receding contact line. We measure the microscale receding contact angle of each bridge and show that the Gibbs criterion is satisfied at the microscale. We reveal a hitherto unknown self-similar depinning mechanism that shows how some hierarchical textures such as lotus leaves lead to reduced pinning, and counter-intuitively, how some lead to increased pinning. We develop a model to predict adhesion force and experimentally verify the model's broad applicability on both synthetic and natural textured surfaces.

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

    KAUST Repository

    Ndiaye, Papa Birame

    2017-02-24

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

  9. Halbach Effect at the Nanoscale from Chiral Spin Textures.

    Science.gov (United States)

    Marioni, Miguel A; Penedo, Marcos; Baćani, Mirko; Schwenk, Johannes; Hug, Hans J

    2018-04-11

    Mallinson's idea that some spin textures in planar magnetic structures could produce an enhancement of the magnetic flux on one side of the plane at the expense of the other gave rise to permanent magnet configurations known as Halbach magnet arrays. Applications range from wiggler magnets in particle accelerators and free electron lasers to motors and magnetic levitation trains, but exploiting Halbach arrays in micro- or nanoscale spintronics devices requires solving the problem of fabrication and field metrology below a 100 μm size. In this work, we show that a Halbach configuration of moments can be obtained over areas as small as 1 μm × 1 μm in sputtered thin films with Néel-type domain walls of unique domain wall chirality, and we measure their stray field at a controlled probe-sample distance of 12.0 ± 0.5 nm. Because here chirality is determined by the interfacial Dyzaloshinkii-Moriya interaction, the field attenuation and amplification is an intrinsic property of this film, allowing for flexibility of design based on an appropriate definition of magnetic domains. Skyrmions (magnetic fields and mapping of the spin structure shows they funnel the field toward one specific side of the film given by the sign of the Dyzaloshinkii-Moriya interaction parameter D.

  10. Spin Texture And Magnetic Properties Of Fe-Si-Co Alloys

    International Nuclear Information System (INIS)

    Schneeweiss, O.; Zak, T.; Jiraskova, Y.; Havlicek, S.; Solyom, A.; Marko, P.

    1998-01-01

    The Fe-13at.%Si alloys with 1, 3, and 5 at.% of Co were investigated. Spin texture, atomic configuration, and Curie temperature were studied in dependence on chemical composition and heat treatment. Data on atomic arrangements derived form Moessbauer spectra and Curie temperatures showed that Co atoms substituted regular positions of Fe atoms in the bcc lattice. Spin texture was found to be only slightly dependent on the chemical composition of the alloys, however, it varies with heat treatment considerably. (Authors)

  11. Relaxations in spin glasses: Similarities and differences from ordinary glasses

    International Nuclear Information System (INIS)

    Ngai, K.L.; Rajagopal, A.K.; Huang, C.Y.

    1984-01-01

    Relaxation phenomena have become a major concern in the physics of spin glasses. There are certain resemblances of these relaxation properties to those of ordinary glasses. In this work, we compare the relaxation properties of spin glasses near the freezing temperature with those of glasses near the glass transition temperature. There are similarities between the two types of glasses. Moreover, the relaxation properties of many glasses and spin glasses are in conformity with two coupled ''universality'' relations predicted by a recent model of relaxations in condensed matter

  12. Self-Similarity Based Corresponding-Point Extraction from Weakly Textured Stereo Pairs

    Directory of Open Access Journals (Sweden)

    Min Mao

    2014-01-01

    Full Text Available For the areas of low textured in image pairs, there is nearly no point that can be detected by traditional methods. The information in these areas will not be extracted by classical interest-point detectors. In this paper, a novel weakly textured point detection method is presented. The points with weakly textured characteristic are detected by the symmetry concept. The proposed approach considers the gray variability of the weakly textured local regions. The detection mechanism can be separated into three steps: region-similarity computation, candidate point searching, and refinement of weakly textured point set. The mechanism of radius scale selection and texture strength conception are used in the second step and the third step, respectively. The matching algorithm based on sparse representation (SRM is used for matching the detected points in different images. The results obtained on image sets with different objects show high robustness of the method to background and intraclass variations as well as to different photometric and geometric transformations; the points detected by this method are also the complement of points detected by classical detectors from the literature. And we also verify the efficacy of SRM by comparing with classical algorithms under the occlusion and corruption situations for matching the weakly textured points. Experiments demonstrate the effectiveness of the proposed weakly textured point detection algorithm.

  13. Similar Symmetries: The Role of Wallpaper Groups in Perceptual Texture Similarity

    Directory of Open Access Journals (Sweden)

    Fraser Halley

    2011-05-01

    Full Text Available Periodic patterns and symmetries are striking visual properties that have been used decoratively around the world throughout human history. Periodic patterns can be mathematically classified into one of 17 different Wallpaper groups, and while computational models have been developed which can extract an image's symmetry group, very little work has been done on how humans perceive these patterns. This study presents the results from a grouping experiment using stimuli from the different wallpaper groups. We find that while different images from the same wallpaper group are perceived as similar to one another, not all groups have the same degree of self-similarity. The similarity relationships between wallpaper groups appear to be dominated by rotations.

  14. Skyrmions and Novel Spin Textures in FeGe Thin Films and Artificial B20 Heterostructures

    Science.gov (United States)

    Ahmed, Adam Saied

    Skyrmions are magnetic spin textures that have a non-zero topological winding number associated with them. They have attracted much interest recently since they can be as small as 1 nm and could be the next generation of magnetic memory and logic. First, we grow epitaxial films of FeGe by molecular beam epitaxy and characterized the skyrmion properties. This had led us to image skyrmions in real-space with Lorentz transmission electron microscopy for the first time in the United States. Next, from an extensive series of thin and thick films, we have experimentally shown the existence of a magnetic surface state in FeGe and, consequently, any skyrmion material for the first time. Complementary theoretical calculations supported the existence of chiral bobbers--a surface state only predicted in 2015. Next, we fabricated for the first time a new class of skyrmion materials: B20 superlattices. These novel heterostructures of [FeGe/MnGe/CrGe] have now opened the door for tunable skyrmion systems with both Dresselhaus and Rashba Dzyaloshinskii-Moriya interactions. Additionally, we perform resonant soft x-ray scattering to image magnetic spin textures in reciprocal space for FeGe thin films in transmission. We have accomplished the removal of substrate and left an isolated single-crystal FeGe film. Lastly, SrO is grown on graphene as a crystalline, atomically smooth, and pinhole free tunnel barrier for spin injection.

  15. Spin texturing in quantum wires with Rashba and Dresselhaus spin–orbit interactions and in-plane magnetic field

    International Nuclear Information System (INIS)

    Gisi, B; Sakiroglu, S; Sokmen, İ

    2016-01-01

    In this work, we investigate the effects of interplay of spin–orbit interaction and in-plane magnetic fields on the electronic structure and spin texturing of parabolically confined quantum wire. Numerical results reveal that the competing effects between Rashba and Dresselhaus spin–orbit interactions and the external magnetic field lead to a complicated energy spectrum. We find that the spin texturing owing to the coupling between subbands can be modified by the strength of spin–orbit couplings as well as the magnitude and the orientation angle of the external magnetic field. (paper)

  16. Unraveling skyrmion spin texture using resonant soft x-ray scattering

    Science.gov (United States)

    Roy, Sujoy

    2015-03-01

    The recent discovery of skyrmions, that were originally predicted in context of high energy physics, in magnetic materials has sparked tremendous interest in the research community due to its rich physics and potential in spintronics applications. Skyrmions have an unusual spin texture that manifests as magnetic knot and can be easily moved around. Understanding the fundamental physics and mechanisms for controlling their dynamical properties presents important scientific challenges. So far experimental verifications of the skyrmions in magnetic systems have come from neutron scattering and Lorentz transmission electron microscopy (TEM) measurements. In this talk we report the first observation of the skyrmions using resonant soft x-ray scattering. We have used soft x-rays tuned to the Cu L3 edge to diffract off the skyrmion lattice in a multiferroic Cu2OSeO3 compound. We show that in Cu2OSeO3 there exist two skyrmion lattices arising due to the two inequivalent Cu-O sublattices that have two different magnetically active d-orbitals. The two skyrmion sublattices are mutually rotated with respect to each other. The angle of rotation could be changed by an external magnetic field, thereby indicating possible existence of a new phase. We have also studied skyrmion spin texture in an ultra-thin Fe/Gd multilayer that shows perpendicular anisotropy. The Fe/Gd sample exhibits a near perfect aligned stripe phase. Within a small range of temperature and magnetic field we observe a hexagonal scattering pattern due to skyrmion bubbles. Analysis of the scattering pattern suggests that the skyrmion lattice unit cell contains two skyrmions. The biskyrmion state is also revealed by Lorentz TEM images. The near room temperature discovery of skyrmion in a technology relevant material is a significant step towards using skyrmions in magnetic devices. Work at LBNL was supported by the Office of Basic Energy Sciences of the U.S. Department of Energy (Contract No. DE-AC02-05CH11231).

  17. Electrohydrodynamic spinning of random-textured silver webs for electrodes embedded in flexible organic solar cells

    Science.gov (United States)

    Yoon, Dai Geon; Chin, Byung Doo; Bail, Robert

    2017-03-01

    A convenient process for fabricating a transparent conducting electrode on a flexible substrate is essential for numerous low-cost optoelectronic devices, including organic solar cells (OSCs), touch sensors, and free-form lighting applications. Solution-processed metal-nanowire arrays are attractive due to their low sheet resistance and optical clarity. However, the limited conductance at wire junctions and the rough surface topology still need improvement. Here, we present a facile process of electrohydrodynamic spinning using a silver (Ag) - polymer composite paste with high viscosity. Unlike the metal-nanofiber web formed by conventional electrospinning, a relatively thick, but still invisible-to-naked eye, Ag-web random pattern was formed on a glass substrate. The process parameters such as the nozzle diameter, voltage, flow rate, standoff height, and nozzle-scanning speed, were systematically engineered. The formed random texture Ag webs were embedded in a flexible substrate by in-situ photo-polymerization, release from the glass substrate, and post-annealing. OSCs with a donor-acceptor polymeric heterojunction photoactive layer were prepared on the Ag-web-embedded flexible films with various Ag-web densities. The short-circuit current and the power conversion efficiency of an OSC with a Ag-web-embedded electrode were not as high as those of the control sample with an indium-tin-oxide electrode. However, the Ag-web textures embedded in the OSC served well as electrodes when bent (6-mm radius), showing a power conversion efficiency of 2.06% (2.72% for the flat OSC), and the electrical stability of the Ag-web-textured patterns was maintained for up to 1,000 cycles of bending.

  18. The Occurrence of Anomalous Conductance Plateaus and Spin Textures in Quantum Point Contacts

    Science.gov (United States)

    Wan, J.; Cahay, M.; Debray, P.; Newrock, R.

    2010-03-01

    Recently, we used a NEGF formalism [1] to provide a theoretical explanation for the experimentally observed 0.5G0 (G0=2e^2/h) plateau in the conductance of side-gated quantum point contacts (QPCs) in the presence of lateral spin-orbit coupling (LSOC) [2]. We showed that the 0.5G0 plateau appears in the QPCs without any external magnetic field as a result of three ingredients: an asymmetric lateral confinement, a LSOC, and a strong electron-electron (e-e) interaction. In this report, we present the results of simulations for a wide range of QPC dimensions and biasing parameters showing that the same physics predicts the appearance of other anomalous plateaus at non-integer values of G0, including the well-known 0.7G0 anomaly. These features are related to a plethora of spin textures in the QPC that depend sensitively on material, device, biasing parameters, temperature, and the strength of the e-e interaction. [1] J. Wan, M. Cahay, P. Debray, and R.S. Newrock, Phys. Rev. B 80, 155440 (2009). [2] P. Debray, S.M. Rahman, J. Wan, R.S. Newrock, M. Cahay, A.T. Ngo, S.E. Ulloa, S.T. Herbert, M. Muhammad, and M. Johnson, Nature Nanotech. 4, 759 (2009).

  19. Spin polynomial similarity transformation for repulsive Hamiltonians: interpolating between coupled cluster and spin-projected unrestricted Hartree-Fock.

    Science.gov (United States)

    Gomez, John A; Degroote, Matthias; Zhao, Jinmo; Qiu, Yiheng; Scuseria, Gustavo E

    2017-08-23

    Our overarching goal is to be able to describe both weak and strong correlation with a single, computationally affordable method without sacrificing important qualities of the wavefunction, e.g. symmetries of the Hamiltonian. We know that coupled cluster theory with low-order excitations is excellent at describing weakly-correlated systems near equilibrium, but breaks down as systems become more strongly correlated. Projected Hartree-Fock on the other hand is inherently capable of describing multireference character, but misses weak correlation. We are thus exploring how best to combine coupled cluster and projected Hartree-Fock in our search for a computationally feasible method that is applicable across a wide range of correlation strengths. In this manuscript, we adapt our earlier work on the pairing Hamiltonian to repulsive Hamiltonians, resulting in the spin polynomial similarity transformation (SpinPoST) interpolation. SpinPoST parameterizes the wavefunction in order to interpolate between the coupled cluster and spin-projected unrestricted Hartree-Fock ansätze self consistently, and is a spin-symmetry adapted model which involves only single and double excitations. We employ a unique approach of optimizing the wavefunction by minimizing the effect of connected quadruple excitations, resulting in a method which is spin-symmetry adapted and is comparable energetically to coupled cluster with singles and doubles for weak correlation and spin-projected Hartree-Fock for strong correlation.

  20. Self-similar spectral structures and edge-locking hierarchy in open-boundary spin chains

    International Nuclear Information System (INIS)

    Haque, Masudul

    2010-01-01

    For an anisotropic Heisenberg (XXZ) spin chain, we show that an open boundary induces a series of approximately self-similar features at different energy scales, high up in the eigenvalue spectrum. We present a nonequilibrium phenomenon related to this fractal structure, involving states in which a connected block near the edge is polarized oppositely to the rest of the chain. We show that such oppositely polarized blocks can be 'locked' to the edge of the spin chain and that there is a hierarchy of edge-locking effects at various orders of the anisotropy. The phenomenon enables dramatic control of quantum-state transmission and magnetization control.

  1. Development of crystal texture in R-lean RFeCoNbB (R = Nd, Pr) alloy during melt spinning processes

    International Nuclear Information System (INIS)

    Li, Wei; Li, Lanlan; Liu, Yanguo; Zhang, Xiangyi

    2012-01-01

    Highlights: ► We study the texture development during the melt spinning processes of R-lean alloys. ► A strong (0 0 l) texture parallel to the ribbon plane for (Nd,Pr) 2 Fe 14 B is obtained. ► The texture for R 2 Fe 14 B crystals can develop by a seeding effect of α-Fe texture. ► The anisotropic nanocomposite magnet yields M r = 0.78M s and large (BH) max = 25.2 MGOe. - Abstract: The formation of crystal texture of R 2 Fe 14 B nanocrystals in R–Fe–B (R = rare earth) alloys with low R content ( 2 Fe 14 B nanocrystals during the melt spinning processes of Nd 3.6 Pr 5.4 Fe 80 Co 3 NbB 7 by effectively employing the seeding effect of α-Fe nanocrystal texture. The (Nd,Pr) 2 Fe 14 B nanocrystals produced from the R-lean alloy at a wheel speed of 18 m/s show a strong (0 0 l) texture parallel to the ribbon plane, which yields a high remanence M r = 0.78M s and a large energy product (BH) max = 25.2 MGOe for the α-Fe/(Nd,Pr) 2 Fe 14 B nanocomposite ribbons. The present study provides a promising approach to prepare anisotropic nanocomposite magnets from R-lean alloys.

  2. Proximity Band Structure and Spin Textures on Both Sides of Topological-Insulator/Ferromagnetic-Metal Interface and Their Charge Transport Probes.

    Science.gov (United States)

    Marmolejo-Tejada, Juan Manuel; Dolui, Kapildeb; Lazić, Predrag; Chang, Po-Hao; Smidstrup, Søren; Stradi, Daniele; Stokbro, Kurt; Nikolić, Branislav K

    2017-09-13

    The control of recently observed spintronic effects in topological-insulator/ferromagnetic-metal (TI/FM) heterostructures is thwarted by the lack of understanding of band structure and spin textures around their interfaces. Here we combine density functional theory with Green's function techniques to obtain the spectral function at any plane passing through atoms of Bi 2 Se 3 and Co or Cu layers comprising the interface. Instead of naively assumed Dirac cone gapped by the proximity exchange field spectral function, we find that the Rashba ferromagnetic model describes the spectral function on the surface of Bi 2 Se 3 in contact with Co near the Fermi level E F 0 , where circular and snowflake-like constant energy contours coexist around which spin locks to momentum. The remnant of the Dirac cone is hybridized with evanescent wave functions from metallic layers and pushed, due to charge transfer from Co or Cu layers, a few tenths of an electron-volt below E F 0 for both Bi 2 Se 3 /Co and Bi 2 Se 3 /Cu interfaces while hosting distorted helical spin texture wounding around a single circle. These features explain recent observation of sensitivity of spin-to-charge conversion signal at TI/Cu interface to tuning of E F 0 . Crucially for spin-orbit torque in TI/FM heterostructures, few monolayers of Co adjacent to Bi 2 Se 3 host spectral functions very different from the bulk metal, as well as in-plane spin textures (despite Co magnetization being out-of-plane) due to proximity spin-orbit coupling in Co induced by Bi 2 Se 3 . We predict that out-of-plane tunneling anisotropic magnetoresistance in Cu/Bi 2 Se 3 /Co vertical heterostructure can serve as a sensitive probe of the type of spin texture residing at E F 0 .

  3. Spin texture of Bi2Se3 thin films in the quantum tunneling limit.

    Science.gov (United States)

    Landolt, Gabriel; Schreyeck, Steffen; Eremeev, Sergey V; Slomski, Bartosz; Muff, Stefan; Osterwalder, Jürg; Chulkov, Evgueni V; Gould, Charles; Karczewski, Grzegorz; Brunner, Karl; Buhmann, Hartmut; Molenkamp, Laurens W; Dil, J Hugo

    2014-02-07

    By means of spin- and angle-resolved photoelectron spectroscopy we studied the spin structure of thin films of the topological insulator Bi2Se3 grown on InP(111). For thicknesses below six quintuple layers the spin-polarized metallic topological surface states interact with each other via quantum tunneling and a gap opens. Our measurements show that the resulting surface states can be described by massive Dirac cones which are split in a Rashba-like manner due to the substrate induced inversion asymmetry. The inner and the outer Rashba branches have distinct localization in the top and the bottom part of the film, whereas the band apices are delocalized throughout the entire film. Supported by calculations, our observations help in the understanding of the evolution of the surface states at the topological phase transition and provide the groundwork for the realization of two-dimensional spintronic devices based on topological semiconductors.

  4. Spin-transfer torques in antiferromagnetic textures: efficiency and quantification method

    Czech Academy of Sciences Publication Activity Database

    Yamane, Y.; Ieda, J.; Sinova, Jairo

    2016-01-01

    Roč. 94, č. 5 (2016), 1-8, č. článku 054409. ISSN 2469-9950 R&D Projects: GA ČR GB14-37427G Institutional support: RVO:68378271 Keywords : spin-transfer torques * antiferromagnets Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.836, year: 2016

  5. Magnetism, Spin Texture, and In-Gap States: Atomic Specialization at the Surface of Oxygen-Deficient SrTiO_{3}.

    Science.gov (United States)

    Altmeyer, Michaela; Jeschke, Harald O; Hijano-Cubelos, Oliver; Martins, Cyril; Lechermann, Frank; Koepernik, Klaus; Santander-Syro, Andrés F; Rozenberg, Marcelo J; Valentí, Roser; Gabay, Marc

    2016-04-15

    Motivated by recent spin- and angular-resolved photoemission (SARPES) measurements of the two-dimensional electronic states confined near the (001) surface of oxygen-deficient SrTiO_{3}, we explore their spin structure by means of ab initio density functional theory (DFT) calculations of slabs. Relativistic nonmagnetic DFT calculations display Rashba-like spin winding with a splitting of a few meV and when surface magnetism on the Ti ions is included, bands become spin-split with an energy difference ∼100  meV at the Γ point, consistent with SARPES findings. While magnetism tends to suppress the effects of the relativistic Rashba interaction, signatures of it are still clearly visible in terms of complex spin textures. Furthermore, we observe an atomic specialization phenomenon, namely, two types of electronic contributions: one is from Ti atoms neighboring the oxygen vacancies that acquire rather large magnetic moments and mostly create in-gap states; another comes from the partly polarized t_{2g} itinerant electrons of Ti atoms lying further away from the oxygen vacancy, which form the two-dimensional electron system and are responsible for the Rashba spin winding and the spin splitting at the Fermi surface.

  6. Perpendicular magnetic anisotropy, unconventional magnetization texture and extraordinary gradual spin reorientation transition of cobalt films in contact with graphene (Conference Presentation)

    Science.gov (United States)

    Rougemaille, Nicolas; Vu, Anh Duc; Chen, Gong; N'Diaye, Alpha T.; Schmid, Andreas K.; Coraux, Johann

    2016-10-01

    Owing to its peculiar electronic band structure, high carrier mobility and long spin diffusion length, graphene is a promising two-dimensional material for microelectronics and spintronics. Graphene also shows interesting magnetic properties when in contact with a ferromagnetic metal (FM). For instance, graphene carries a net magnetic moment when deposited on Fe/Ni(111), and a significant spin splitting can be induced in graphene due to proximity with a heavy element. While these results illustrate potential advantages of integrating graphene within a magnetic stack, the influence of graphene on the magnetic properties of a FM is still largely unexplored. In particular, non-magnetic overlayers generally affect the magnetic anisotropy energy (MAE) of thin layers, where interfaces play an important role. We can then wonder how an interface with graphene would influence the MAE of a thin FM film. Using spin-polarized low-energy electron microscopy, we study how a graphene overlayer affects the magnetic properties of atomically flat, nm-thick Co films grown on Ir(111). In this contribution, we report several astonishing magnetic properties of graphene-covered Co films: 1) Perpendicular magnetic anisotropy is favored over an unusually large thickness range, 2) Vectorial magnetic imaging reveals an extraordinarily gradual thickness-dependent spin reorientation transition (SRT), 3) During the SRT, cobalt films are characterized by an unconventional spin texture, 4) Spectroscopy measurements indicate that incident spin-polarized electrons do not suffer substantial spin-dependent collisions a few electron-Volts above the vacuum level. These properties strikingly differ from those of pristine cobalt films and could open new prospects in surface magnetism and spintronics.

  7. Two spin-canting textures in the antiferromagnetic phase AF1 of MnWO4 based on the new polar atomistic model in P2

    Science.gov (United States)

    Park, S.-H.; Liu, B.-Q.; Behal, D.; Pedersen, B.; Schneidewind, A.

    2018-04-01

    The low temperature antiferromagnetic (AF) phase of MnWO4 (the so-called AF1 phase) exhibits different spin-canting configurations at two Mn2+ sublattices of the (3  +  1)-dimensional magnetic structure. The suggested superspace group {{\\boldsymbol P}}2.1^\\prime(α, 1/2, γ)0s is a significant consequence of the polar space group {{\\boldsymbol P}} 2 true for the nuclear structure of MnWO4. Density functional theory calculations showed that its ground state prefers this two spin-canting system. The structural difference between two independent atomic sites for Mn (Mn a , Mn b ) is too small to allow microscopically detectable electric polarisation. However, this hidden intrinsic polar character allows AF1 two commensurately modulated spin-canting textures. This is considered as the prerequisite onset of the improper ferroelectricity enhanced by the helical spin order in the multiferroic phase AF2 of MnWO4.

  8. Self-similarity of proton spin and asymmetry of jet production

    Czech Academy of Sciences Publication Activity Database

    Tokarev, M. V.; Zborovský, Imrich

    2015-01-01

    Roč. 12, č. 2 (2015), s. 214-220 ISSN 1547-4771 R&D Projects: GA MŠk LG14004 Institutional support: RVO:61389005 Keywords : asymmetry * high energy * jets * polarization * proton-proton collisions * Self-similarity Subject RIV: BE - Theoretical Physics

  9. Attenuated coupled cluster: a heuristic polynomial similarity transformation incorporating spin symmetry projection into traditional coupled cluster theory

    Science.gov (United States)

    Gomez, John A.; Henderson, Thomas M.; Scuseria, Gustavo E.

    2017-11-01

    In electronic structure theory, restricted single-reference coupled cluster (CC) captures weak correlation but fails catastrophically under strong correlation. Spin-projected unrestricted Hartree-Fock (SUHF), on the other hand, misses weak correlation but captures a large portion of strong correlation. The theoretical description of many important processes, e.g. molecular dissociation, requires a method capable of accurately capturing both weak- and strong correlation simultaneously, and would likely benefit from a combined CC-SUHF approach. Based on what we have recently learned about SUHF written as particle-hole excitations out of a symmetry-adapted reference determinant, we here propose a heuristic coupled cluster doubles model to attenuate the dominant spin collective channel of the quadratic terms in the coupled cluster equations. Proof of principle results presented here are encouraging and point to several paths forward for improving the method further.

  10. Similarity transformed equation of motion coupled-cluster theory based on an unrestricted Hartree-Fock reference for applications to high-spin open-shell systems.

    Science.gov (United States)

    Huntington, Lee M J; Krupička, Martin; Neese, Frank; Izsák, Róbert

    2017-11-07

    The similarity transformed equation of motion coupled-cluster approach is extended for applications to high-spin open-shell systems, within the unrestricted Hartree-Fock (UHF) formalism. An automatic active space selection scheme has also been implemented such that calculations can be performed in a black-box fashion. It is observed that both the canonical and automatic active space selecting similarity transformed equation of motion (STEOM) approaches perform about as well as the more expensive equation of motion coupled-cluster singles doubles (EOM-CCSD) method for the calculation of the excitation energies of doublet radicals. The automatic active space selecting UHF STEOM approach can therefore be employed as a viable, lower scaling alternative to UHF EOM-CCSD for the calculation of excited states in high-spin open-shell systems.

  11. Similarity transformed equation of motion coupled-cluster theory based on an unrestricted Hartree-Fock reference for applications to high-spin open-shell systems

    Science.gov (United States)

    Huntington, Lee M. J.; Krupička, Martin; Neese, Frank; Izsák, Róbert

    2017-11-01

    The similarity transformed equation of motion coupled-cluster approach is extended for applications to high-spin open-shell systems, within the unrestricted Hartree-Fock (UHF) formalism. An automatic active space selection scheme has also been implemented such that calculations can be performed in a black-box fashion. It is observed that both the canonical and automatic active space selecting similarity transformed equation of motion (STEOM) approaches perform about as well as the more expensive equation of motion coupled-cluster singles doubles (EOM-CCSD) method for the calculation of the excitation energies of doublet radicals. The automatic active space selecting UHF STEOM approach can therefore be employed as a viable, lower scaling alternative to UHF EOM-CCSD for the calculation of excited states in high-spin open-shell systems.

  12. Symmetric textures

    International Nuclear Information System (INIS)

    Ramond, P.

    1993-01-01

    The Wolfenstein parametrization is extended to the quark masses in the deep ultraviolet, and an algorithm to derive symmetric textures which are compatible with existing data is developed. It is found that there are only five such textures

  13. TEXTURAL FRACTOGRAPHY

    Directory of Open Access Journals (Sweden)

    Hynek Lauschmann

    2011-05-01

    Full Text Available The reconstitution of the history of a fatigue process is based on the knowledge of any correspondences between the morphology of the crack surface and the velocity of the crack growth (crack growth rate - CGR. The textural fractography is oriented to mezoscopic SEM magnifications (30 to 500x. Images contain complicated textures without distinct borders. The aim is to find any characteristics of this texture, which correlate with CGR. Pre-processing of images is necessary to obtain a homogeneous texture. Three methods of textural analysis have been developed and realized as computational programs: the method based on the spectral structure of the image, the method based on a Gibbs random field (GRF model, and the method based on the idealization of light objects into a fibre process. In order to extract and analyze the fibre process, special methods - tracing fibres and a database-oriented analysis of a fibre process - have been developed.

  14. Improving the efficiency of copper indium gallium (Di-selenide (CIGS solar cells through integration of a moth-eye textured resist with a refractive index similar to aluminum doped zinc oxide

    Directory of Open Access Journals (Sweden)

    M. Burghoorn

    2014-12-01

    Full Text Available Textured transparent conductors are widely used in thin-film silicon solar cells. They lower the reflectivity at interfaces between different layers in the cell and/or cause an increase in the path length of photons in the Si absorber layer, which both result in an increase in the number of absorbed photons and, consequently, an increase in short-circuit current density (Jsc and cell efficiency. Through optical simulations, we recently obtained strong indications that texturing of the transparent conductor in copper indium gallium (di-selenide (CIGS solar cells is also optically advantageous. Here, we experimentally demonstrate that the Jsc and efficiency of CIGS solar cells with an absorber layer thickness (dCIGS of 0.85 μm, 1.00 μm and 2.00 μm increase through application of a moth-eye textured resist with a refractive index that is sufficiently similar to AZO (nresist = 1.792 vs. nAZO = 1.913 at 633 nm to avoid large optical losses at the resist-AZO interface. On average, Jsc increases by 7.2%, which matches the average reduction in reflection of 7.0%. The average relative increase in efficiency is slightly lower (6.0%. No trend towards a larger relative increase in Jsc with decreasing dCIGS was observed. Ergo, the increase in Jsc can be fully explained by the reduction in reflection, and we did not observe any increase in Jsc based on an increased photon path length.

  15. Crystallographic textures

    Directory of Open Access Journals (Sweden)

    Klosek Vincent

    2017-01-01

    Full Text Available In material science, crystallographic texture is an important microstructural parameter which directly determines the anisotropy degree of most physical properties of a polycrystalline material at the macro scale. Its characterization is thus of fundamental and applied importance, and should ideally be performed prior to any physical property measurement or modeling. Neutron diffraction is a tool of choice for characterizing crystallographic textures: its main advantages over other existing techniques, and especially over the X-ray diffraction techniques, are due to the low neutron absorption by most elements. The obtained information is representative of a large number of grains, leading to a better accuracy of the statistical description of texture.

  16. General relativistic collapse of textures

    International Nuclear Information System (INIS)

    Durrer, R.; Heusler, M.; Jetzer, P.; Straumann, N.

    1991-01-01

    We present an exact self-similar solution of the coupled Einstein-σ model equations which describes the general relativistic collapse of global textures. In one coordinate system the texture geometry has a simple interpretation in terms of a deficit solid angle. We also briefly discuss the behavior of matter and light in this geometry. In particular we show that the weak field approximation for the metric perturbations of flat space texture solutions is quantitatively quite reliable. (orig.)

  17. RotoTexture: automated tools for texturing raw video.

    Science.gov (United States)

    Fang, Hui; Hart, John C

    2006-01-01

    We propose a video editing system that allows a user to apply a time-coherent texture to a surface depicted in the raw video from a single uncalibrated camera, including the surface texture mapping of a texture image and the surface texture synthesis from a texture swatch. Our system avoids the construction of a 3D shape model and instead uses the recovered normal field to deform the texture so that it plausibly adheres to the undulations of the depicted surface. The texture mapping method uses the nonlinear least-squares optimization of a spring model to control the behavior of the texture image as it is deformed to match the evolving normal field through the video. The texture synthesis method uses a coarse optical flow to advect clusters of pixels corresponding to patches of similarly oriented surface points. These clusters are organized into a minimum advection tree to account for the dynamic visibility of clusters. We take a rather crude approach to normal recovering and optical flow estimation, yet the results are robust and plausible for nearly diffuse surfaces such as faces and t-shirts.

  18. Spin Hall and spin swapping torques in diffusive ferromagnets

    KAUST Repository

    Pauyac, C. O.

    2017-12-08

    A complete set of the generalized drift-diffusion equations for a coupled charge and spin dynamics in ferromagnets in the presence of extrinsic spin-orbit coupling is derived from the quantum kinetic approach, covering major transport phenomena, such as the spin and anomalous Hall effects, spin swapping, spin precession and relaxation processes. We argue that the spin swapping effect in ferromagnets is enhanced due to spin polarization, while the overall spin texture induced by the interplay of spin-orbital and spin precessional effects displays a complex spatial dependence that can be exploited to generate torques and nucleate/propagate domain walls in centrosymmetric geometries without use of external polarizers, as opposed to the conventional understanding of spin-orbit mediated torques.

  19. LOCAL TEXTURE DESCRIPTION FRAMEWORK FOR TEXTURE BASED FACE RECOGNITION

    Directory of Open Access Journals (Sweden)

    R. Reena Rose

    2014-02-01

    Full Text Available Texture descriptors have an important role in recognizing face images. However, almost all the existing local texture descriptors use nearest neighbors to encode a texture pattern around a pixel. But in face images, most of the pixels have similar characteristics with that of its nearest neighbors because the skin covers large area in a face and the skin tone at neighboring regions are same. Therefore this paper presents a general framework called Local Texture Description Framework that uses only eight pixels which are at certain distance apart either circular or elliptical from the referenced pixel. Local texture description can be done using the foundation of any existing local texture descriptors. In this paper, the performance of the proposed framework is verified with three existing local texture descriptors Local Binary Pattern (LBP, Local Texture Pattern (LTP and Local Tetra Patterns (LTrPs for the five issues viz. facial expression, partial occlusion, illumination variation, pose variation and general recognition. Five benchmark databases JAFFE, Essex, Indian faces, AT&T and Georgia Tech are used for the experiments. Experimental results demonstrate that even with less number of patterns, the proposed framework could achieve higher recognition accuracy than that of their base models.

  20. Strings, texture, and inflation

    International Nuclear Information System (INIS)

    Hodges, H.M.; Primack, J.R.

    1991-01-01

    We examine mechanisms, several of which are proposed here, to generate structure formation, or to just add large-scale features, through either gauged or global cosmic strings or global texture, within the framework of inflation. We first explore the possibility that strings or texture form if there is no coupling between the topological theory and the inflaton or spacetime curvature, via (1) quantum creation, and (2) a sufficiently high reheat temperature. In addition, we examine the prospects for the inflaton field itself to generate strings or texture. Then, models with the string/texture field coupled to the curvature, and an equivalent model with coupling to the inflaton field, are considered in detail. The requirement that inflationary density fluctuations are not so large as to conflict with observations leads to a number of constraints on model parameters. We find that strings of relevance for structure formation can form in the absence of coupling to the inflaton or curvature through the process of quantum creation, but only if the strings are strongly type I, or if they are global strings. If formed after reheating, naturalness suggests that gauged cosmic strings correspond to a type-I superconductor. Similarly, gauged strings formed during inflation via conformal coupling ξ=1/6 to the spacetime curvature (in a model suggested by Yokoyama in order to evade the millisecond pulsar constraint on cosmic strings) are expected to be strongly type I

  1. Improving the efficiency of copper indium gallium (Di-)selenide (CIGS) solar cells through integration of a moth-eye textured resist with a refractive index similar to aluminum doped zinc oxide

    NARCIS (Netherlands)

    Burghoorn, M.M.A.; Kniknie, B.J.; Deelen, J. van; Xu, M.; Vroon, Z.A.E.P.; Ee, R.J. van; Belt, R. van de; Buskens, P.J.P.

    2014-01-01

    Textured transparent conductors are widely used in thin-film silicon solar cells. They lower the reflectivity at interfaces between different layers in the cell and/or cause an increase in the path length of photons in the Si absorber layer, which both result in an increase in the number of absorbed

  2. Spontaneous spin textures in multiorbital mott systems

    Czech Academy of Sciences Publication Activity Database

    Kuneš, Jan; Geffroy, D.

    2016-01-01

    Roč. 116, č. 25 (2016), 1-5, č. článku 256403. ISSN 0031-9007 EU Projects: European Commission(XE) 646807 - EXMAG Institutional support: RVO:68378271 Keywords : liquid crystals Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 8.462, year: 2016

  3. Comments on "Steganography Using Reversible Texture Synthesis".

    Science.gov (United States)

    Zhou, Hang; Chen, Kejiang; Zhang, Weiming; Yu, Nenghai

    2017-04-01

    Message hiding in texture image synthesis is a novel steganography approach by which we resample a smaller texture image and synthesize a new texture image with a similar local appearance and an arbitrary size. However, the mirror operation over the image boundary is flawed and is easy to attack. We propose an attacking method on this steganography, which can not only detect the stego-images but can also extract the hidden messages.

  4. Influence of face-centered-cubic texturing of Co2Fe6B2 pinned layer on tunneling magnetoresistance ratio decrease in Co2Fe6B2/MgO-based p-MTJ spin valves stacked with a [Co/Pd](n)-SyAF layer.

    Science.gov (United States)

    Takemura, Yasutaka; Lee, Du-Yeong; Lee, Seung-Eun; Chae, Kyo-Suk; Shim, Tae-Hun; Lian, Guoda; Kim, Moon; Park, Jea-Gun

    2015-05-15

    The TMR ratio of Co2Fe6B2/MgO-based p-MTJ spin valves stacked with a [Co/Pd]n-SyAF layer decreased rapidly when the ex situ magnetic annealing temperature (Tex) was increased from 275 to 325 °C, and this decrease was associated with degradation of the Co2Fe6B2 pinned layer rather than the Co2Fe6B2 free layer. At a Tex above 325 °C the amorphous Co2Fe6B2 pinned layer was transformed into a face-centered-cubic (fcc) crystalline layer textured from [Co/Pd]n-SyAF, abruptly reducing the Δ1 coherence tunneling of perpendicular-spin-torque electrons between the (100) MgO tunneling barrier and the fcc Co2Fe6B2 pinned layer.

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

    KAUST Repository

    Ndiaye, Papa Birame

    2017-10-31

    In the search for low power operation of microelectronic devices, spin-based solutions have attracted undeniable increasing interest due to their intrinsic magnetic nonvolatility. The ability to electrically manipulate the magnetic order using spin-orbit interaction, associated with the recent emergence of topological spintronics with its promise of highly efficient charge-to-spin conversion in solid state, offer alluring opportunities in terms of system design. Although the related technology is still at its infancy, this thesis intends to contribute to this engaging field by investigating the nature of the charge and spin transport in spin-orbit coupled and topological systems using quantum transport methods. We identified three promising building blocks for next-generation technology, three classes of systems that possibly enhance the spin and charge transport efficiency: (i)- topological insulators, (ii)- spin-orbit coupled magnonic systems, (iii)- topological magnetic textures (skyrmions and 3Q magnetic state). Chapter 2 reviews the basics and essential concepts used throughout the thesis: the spin-orbit coupling, the mathematical notion of topology and its importance in condensed matter physics, then topological magnetism and a zest of magnonics. In Chapter 3, we study the spin-orbit torques at the magnetized interfaces of 3D topological insulators. We demonstrated that their peculiar form, compared to other spin-orbit torques, have important repercussions in terms of magnetization reversal, charge pumping and anisotropic damping. In Chapter 4, we showed that the interplay between magnon current jm and magnetization m in homogeneous ferromagnets with Dzyaloshinskii-Moriya (DM) interaction, produces a field-like torque as well as a damping-like torque. These DM torques mediated by spin wave can tilt the imeaveraged magnetization direction and are similar to Rashba torques for electronic systems. Moreover, the DM torque is more efficient when magnons are

  6. Fiber vs Rolling Texture: Stress State Dependence for Cold-Drawn Wire

    Science.gov (United States)

    Zorina, M. A.; Karabanalov, M. S.; Stepanov, S. I.; Demakov, S. L.; Loginov, Yu. N.; Lobanov, M. L.

    2018-02-01

    The texture of the cold-drawn copper wire was investigated along the radius using electron backscatter diffraction. The complex fiber texture of the central region of the wire was considered as the rolling texture consisting of a set of preferred orientations. The texture of the periphery region was revealed to be similar to the shear texture. The orientation-dependent properties of the wire were proven to be determined by the texture of the near-surface layers.

  7. Texture and neutron diffraction

    International Nuclear Information System (INIS)

    Szpunar, J.

    1976-01-01

    The neutron diffraction method has only recently become a tool for studying the structure of polycrystalline materials. There are some fields such as texture studies where this method offers several advantages over other more common methods. Texture is the main subject of the review. The current status of the theory or deformation and recrystallization texture is discussed briefly. Texture is then described with the aid of the ODF function. Finally, applications of the neutron diffraction method are discussed using several examples of textures measured in metals and in non-metallic materials. Other, less known applications of neutron diffraction are also given, e.g. in stress measurements. The neutron diffraction method is extremely useful for studying the texture of coarse-grained materials. This method provides information on the average texture in a large volume. This enables one to measure texture in the same specimen in which anisotropy of the physical roperties has been measured. Selected examples are provided in which correlations between elastic, plastic and magnetic properties of polycrystalline materials and their texture are pointed out. Texture was measured in all these cases using the neutron diffraction method. (author)

  8. Bayesian exploration for intelligent identification of textures

    Directory of Open Access Journals (Sweden)

    Jeremy A. Fishel

    2012-06-01

    Full Text Available In order to endow robots with humanlike abilities to characterize and identify objects, they must be provided with tactile sensors and intelligent algorithms to select, control and interpret data from useful exploratory movements. Humans make informed decisions on the sequence of exploratory movements that would yield the most information for the task, depending on what the object may be and prior knowledge of what to expect from possible exploratory movements. This study is focused on texture discrimination, a subset of a much larger group of exploratory movements and percepts that humans use to discriminate, characterize, and identify objects. Using a testbed equipped with a biologically inspired tactile sensor (the BioTac® we produced sliding movements similar to those that humans make when exploring textures. Measurement of tactile vibrations and reaction forces when exploring textures were used to extract measures of textural properties inspired from psychophysical literature (traction, roughness, and fineness. Different combinations of normal force and velocity were identified to be useful for each of these three properties. A total of 117 textures were explored with these three movements to create a database of prior experience to use for identifying these same textures in future encounters. When exploring a texture, the discrimination algorithm adaptively selects the optimal movement to make and property to measure based on previous experience to differentiate the texture from a set of plausible candidates, a process we call Bayesian exploration. Performance of 99.6% in correctly discriminating pairs of similar textures was found to exceed human capabilities. Absolute classification from the entire set of 117 textures generally required a small number of well-chosen exploratory movements (median=5 and yielded a 95.4% success rate. The method of Bayesian exploration developed and tested in this paper may generalize well to other

  9. Texture analyses of Sauropod dinosaur bones from Tendaguru

    International Nuclear Information System (INIS)

    Pyzalla, A.R.; Sander, P.M.; Hansen, A.; Ferreyro, R.; Yi, S.-B.; Stempniewicz, M.; Brokmeier, H.-G.

    2006-01-01

    The apatite texture of fossil Brachiosaurus brancai and Barosaurus africanus sauropod bones from the excavation site at Tendaguru, Tanzania, was characterized by neutron diffraction pole figures. The results obtained reveal predominantly -fibre textures of the apatite; the fibre direction coincides with the longitudinal direction of the long bones of the skeletons. Neutron pole figures further indicate that other texture types may also be present. Texture strength is similar to dinosaur tendons and contemporary turkey tendon studied by others. Variations of texture strength across the bone wall cross-sections are not significantly large

  10. Texture analyses of Sauropod dinosaur bones from Tendaguru

    Energy Technology Data Exchange (ETDEWEB)

    Pyzalla, A.R. [TU Wien, Institute of Material Science and Technology, Karlsplatz 13-308, A-1040 Vienna (Austria) and MPI fuer Eisenforschung GmbH, Max-Planck-Str. 1, D-40237 Duesseldorf (Germany)]. E-mail: pyzalla@mpie.de; Sander, P.M. [University of Bonn, Institute of Palaeontology, Nusseallee, D-53115 Bonn (Germany); Hansen, A. [TU Clausthal, Institute of Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processingnd GKSS Research Centre Geesthacht GmbH, Geesthacht, Max-Planck-Str.1, D-21502 Geesthacht (Germany); Ferreyro, R. [TU Wien, Institute of Material Science and Technology, Karlsplatz 13-308, A-1040 Vienna (Austria); Yi, S.-B. [TU Clausthal, Institute of Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processingnd GKSS Research Centre Geesthacht GmbH, Geesthacht, Max-Planck-Str.1, D-21502 Geesthacht (Germany); MPI fuer Eisenforschung GmbH, Max-Planck-Str. 1, D-40237 Duesseldorf (Germany); Stempniewicz, M. [TU Wien, Institute of Material Science and Technology, Karlsplatz 13-308, A-1040 Vienna (Austria); Brokmeier, H.-G. [TU Clausthal, Institute of Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processingnd GKSS Research Centre Geesthacht GmbH, Geesthacht, Max-Planck-Str.1, D-21502 Geesthacht (Germany)

    2006-11-10

    The apatite texture of fossil Brachiosaurus brancai and Barosaurus africanus sauropod bones from the excavation site at Tendaguru, Tanzania, was characterized by neutron diffraction pole figures. The results obtained reveal predominantly <0 0 0 1>-fibre textures of the apatite; the fibre direction coincides with the longitudinal direction of the long bones of the skeletons. Neutron pole figures further indicate that other texture types may also be present. Texture strength is similar to dinosaur tendons and contemporary turkey tendon studied by others. Variations of texture strength across the bone wall cross-sections are not significantly large.

  11. Spin wave spectrum of magnetic nanotubes

    International Nuclear Information System (INIS)

    Gonzalez, A.L.; Landeros, P.; Nunez, Alvaro S.

    2010-01-01

    We investigate the spin wave spectra associated to a vortex domain wall confined within a ferromagnetic nanotube. Basing our study upon a simple model for the energy functional we obtain the dispersion relation, the density of states and dissipation induced life-times of the spin wave excitations in presence of a magnetic domain wall. Our aim is to capture the basics spin wave physics behind the geometrical confinement of nobel magnetic textures.

  12. Measurement of Color Texture

    NARCIS (Netherlands)

    Hoang, M.A.; Geusebroek, J.M.; Deprettere, E.F.; Belloum, A.; Heijnsdijk, J.W.J.; van der Stappen, F.

    2002-01-01

    In computer vision, measurement of image properties such as color or texture is essential. However, existing methods for measuring color and texture in combination are not well-defined neither from a measurement theoretical basis nor from a physical point of view. We propose a solid framework for

  13. Textured perovskite cells

    NARCIS (Netherlands)

    Deelen, J. van; Tezsevin, Y.; Barink, M.

    2017-01-01

    Most research of texturization of solar cells has been devoted to Si based cells. For perovskites, it was assumed that texturization would not have much of an impact because of the relatively low refractive indexes lead to relatively low reflection as compared to the Si based cells. However, our

  14. Mimicking human texture classification

    NARCIS (Netherlands)

    Rogowitz, B.E.; van Rikxoort, Eva M.; van den Broek, Egon; Pappas, T.N.; Schouten, Theo E.; Daly, S.J.

    2005-01-01

    In an attempt to mimic human (colorful) texture classification by a clustering algorithm three lines of research have been encountered, in which as test set 180 texture images (both their color and gray-scale equivalent) were drawn from the OuTex and VisTex databases. First, a k-means algorithm was

  15. Electrical detection of spin-momentum locking in Bi2Se3(Conference Presentation)

    Science.gov (United States)

    Jonker, Berend T.; Li, Connie H.; van't Erve, Olaf M.; Liu, Y.; Li, Y. Y.; Li, Lian

    2016-10-01

    Topological insulators (TIs) exhibit topologically protected metallic surface states populated by massless Dirac fermions with spin-momentum locking - the carrier spin lies in-plane, locked at right angle to the carrier momentum. An unpolarized charge current should thus create a net spin polarization. Here we show direct electrical detection of this bias current induced spin polarization as a voltage measured on a ferromagnetic (FM) metal tunnel barrier surface contact [1]. The voltage measured at this contact is proportional to the projection of the TI spin polarization onto this axis, and similar data are obtained for two different FM contact structures, Fe/Al2O3 and Co/MgO/graphene. From measurements of the carrier type and sign of the spin voltage for n-Bi2Se3 and p-Sb2Te3, we show that transport measurements can be used to determine the chirality of the spin texture [2]. The chirality inverts as one crosses the Dirac point, so that the carrier spin-momentum locking follows a left-hand rule (clockwise chirality) when the Fermi level is above the Dirac point, and right-hand rule below (counter-clockwise chirality). These results demonstrate simple and direct electrical access to the TI Dirac surface state spin system, provide clear evidence for the spin-momentum locking and bias current-induced spin polarization, and enable utilization of these remarkable properties for future technological applications. [1] C. H. Li, O. M. J. van `t Erve, J. T. Robinson, Y. Liu, L. Li , and B. T. Jonker, Nature Nanotech. 9, 218 (2014). [2] C. H. Li, O. M. J. van `t Erve, Y. Y. Li, L. Li and B. T. Jonker, under review.

  16. Spin flexoelectricity and chiral spin structures in magnetic films

    OpenAIRE

    Pyatakov, A. P.; Sergeev, A. S.; Mikailzade, F. A.; Zvezdin, A. K.

    2015-01-01

    In this short review a broad range of chiral phenomena observed in magnetic films (spin cycloid and skyrmion structures formation as well as chirality dependent domain wall motion) is considered under the perspective of spin flexoelectricity, i.e. the relation between bending of magnetization pattern and electric polarization. The similarity and the difference between the spin flexoelectricity and the newly emerged notion of spin flexomagnetism is discussed. The phenomenological arguments bas...

  17. Textures and ores structure

    International Nuclear Information System (INIS)

    Khasanov, A.Kh.

    1988-01-01

    In this part of book author made conclusion that structural-texture particularities reflect the physical and chemical conditions, velocity of minerals crystallization, further tectonic situation, presence appearances of meta-somatic substitution, second decomposition and minerals leaching

  18. Spin current

    CERN Document Server

    Valenzuela, Sergio O; Saitoh, Eiji; Kimura, Takashi

    2012-01-01

    In a new branch of physics and technology called spin-electronics or spintronics, the flow of electrical charge (usual current) as well as the flow of electron spin, the so-called 'spin current', are manipulated and controlled together. This book provides an introduction and guide to the new physics and application of spin current.

  19. Methods of making textured catalysts

    Science.gov (United States)

    Werpy, Todd [West Richland, WA; Frye, Jr., John G.; Wang, Yong [Richland, WA; Zacher, Alan H [Kennewick, WA

    2010-08-17

    A textured catalyst having a hydrothermally-stable support, a metal oxide and a catalyst component is described. Methods of conducting aqueous phase reactions that are catalyzed by a textured catalyst are also described. The invention also provides methods of making textured catalysts and methods of making chemical products using a textured catalyst.

  20. The Tortoise Versus the Hare: Computer Simulation of Euendolithic Microbial Alteration Textures

    Science.gov (United States)

    Banerjee, N. R.; Lee, J.; Izawa, M. R. M.; Tiampo, K.

    2010-04-01

    A computer model has been developed to simulate the production of euendolithic microbial alteration textures in basalt glass; and produces textures that are qualitatively and quantitatively similar to those observed in natural glass bioalteration.

  1. Computer Texture Mapping for Laser Texturing of Injection Mold

    Directory of Open Access Journals (Sweden)

    Yongquan Zhou

    2014-04-01

    Full Text Available Laser texturing is a relatively new multiprocess technique that has been used for machining 3D curved surfaces; it is more flexible and efficient to create decorative texture on 3D curved surfaces of injection molds so as to improve the surface quality and achieve cosmetic surface of molded plastic parts. In this paper, a novel method of laser texturing 3D curved surface based on 3-axis galvanometer scanning unit has been presented to prevent the texturing of injection mold surface from much distortion which is often caused by traditional texturing processes. The novel method has been based on the computer texture mapping technology which has been developed and presented. The developed texture mapping algorithm includes surface triangulation, notations, distortion measurement, control, and numerical method. An interface of computer texture mapping has been built to implement the algorithm of texture mapping approach to controlled distortion rate of 3D texture math model from 2D original texture applied to curvature surface. Through a case study of laser texturing of a high curvature surface of injection mold of a mice top case, it shows that the novel method of laser texturing meets the quality standard of laser texturing of injection mold.

  2. A spin transfer torque magnetoresistance random access memory-based high-density and ultralow-power associative memory for fully data-adaptive nearest neighbor search with current-mode similarity evaluation and time-domain minimum searching

    Science.gov (United States)

    Ma, Yitao; Miura, Sadahiko; Honjo, Hiroaki; Ikeda, Shoji; Hanyu, Takahiro; Ohno, Hideo; Endoh, Tetsuo

    2017-04-01

    A high-density nonvolatile associative memory (NV-AM) based on spin transfer torque magnetoresistive random access memory (STT-MRAM), which achieves highly concurrent and ultralow-power nearest neighbor search with full adaptivity of the template data format, has been proposed and fabricated using the 90 nm CMOS/70 nm perpendicular-magnetic-tunnel-junction hybrid process. A truly compact current-mode circuitry is developed to realize flexibly controllable and high-parallel similarity evaluation, which makes the NV-AM adaptable to any dimensionality and component-bit of template data. A compact dual-stage time-domain minimum searching circuit is also developed, which can freely extend the system for more template data by connecting multiple NM-AM cores without additional circuits for integrated processing. Both the embedded STT-MRAM module and the computing circuit modules in this NV-AM chip are synchronously power-gated to completely eliminate standby power and maximally reduce operation power by only activating the currently accessed circuit blocks. The operations of a prototype chip at 40 MHz are demonstrated by measurement. The average operation power is only 130 µW, and the circuit density is less than 11 µm2/bit. Compared with the latest conventional works in both volatile and nonvolatile approaches, more than 31.3% circuit area reductions and 99.2% power improvements are achieved, respectively. Further power performance analyses are discussed, which verify the special superiority of the proposed NV-AM in low-power and large-memory-based VLSIs.

  3. Phase space representations for spin23

    International Nuclear Information System (INIS)

    Polubarinov, I.V.

    1991-01-01

    General properties of spin matrices and density ones are considered for any spin s. For spin 2 3 phase space representations are constructed. Representations, similar to the Bell one, for the correlator of projections of two spins 2 3 in the singlet state are found. Quantum analogs of the Bell inequality are obtained. 14 refs

  4. Ion-beam texturing of uniaxially textured Ni films

    International Nuclear Information System (INIS)

    Park, S.J.; Norton, D.P.; Selvamanickam, Venkat

    2005-01-01

    The formation of biaxial texture in uniaxially textured Ni thin films via Ar-ion irradiation is reported. The ion-beam irradiation was not simultaneous with deposition. Instead, the ion beam irradiates the uniaxially textured film surface with no impinging deposition flux, which differs from conventional ion-beam-assisted deposition. The uniaxial texture is established via a nonion beam process, with the in-plane texture imposed on the uniaxial film via ion beam bombardment. Within this sequential ion beam texturing method, grain alignment is driven by selective etching and grain overgrowth

  5. Progress in bulk texture measurement using neutron diffraction

    International Nuclear Information System (INIS)

    Xu, Pingguang; Suzuki, Hiroshi; Akita, Koichi; Harjo, Stefanus; Gong, Wu; Tomota, Yo; Ito, Takayoshi; Morii, Yukio; Suzuki, Tetsuya; Lutterotti, Luca

    2015-01-01

    The current status of bulk texture measurements both using angle dispersive neutron diffraction and time-of-flight neutron diffraction at JAEA was briefly reviewed, then the effect of sample orientation coverage in the time-of-flight neutron diffraction on the reliability of reconstructed pole figure on the reliability of reconstructed pole figure was simply compared after the simultaneous Rietveld texture analysis. The similar texture results obtained at different orientation coverage levels suggests that it is possible to reduce the sample rotation times reasonably during the bulk texture measurement. (author)

  6. Quantitative comparison between simulated and experimental FCC rolling textures

    DEFF Research Database (Denmark)

    Wronski, M.; Wierzbanowski, K.; Leffers, Torben

    2015-01-01

    The degree of similarity between simulated and experimental fcc rolling textures is characterized by a single scalar parameter. The textures are simulated with a relatively simple and efficient 1-point model which allows us to vary the strength of the interaction between the grains and the surrou...

  7. Spin flexoelectricity and chiral spin structures in magnetic films

    Science.gov (United States)

    Pyatakov, A. P.; Sergeev, A. S.; Mikailzade, F. A.; Zvezdin, A. K.

    2015-06-01

    In this short review a broad range of chiral phenomena observed in magnetic films (spin cycloid and skyrmion structures formation as well as chirality dependent domain wall motion) is considered under the perspective of spin flexoelectricity, i.e. the relation between bending of magnetization pattern and electric polarization. The similarity and the difference between the spin flexoelectricity and the newly emerged notion of spin flexomagnetism are discussed. The phenomenological arguments based on the geometrical idea of curvature-induced effects are supported by analysis of the microscopic mechanisms of spin flexoelectricity based on three-site ion indirect exchange and twisted RKKY interaction models.

  8. Texture analysis of

    NARCIS (Netherlands)

    Lubsch, A.; Timmermans, K.

    2017-01-01

    Texture analysis is a method to test the physical properties of a material by tension and compression. The growing interest in commercialisation of seaweeds for human food has stimulated research into the physical properties of seaweed tissue. These are important parameters for the survival of

  9. Texture affects color emotion

    NARCIS (Netherlands)

    Lucassen, M.P.; Gevers, T.; Gijsenij, A.

    2011-01-01

    Several studies have recorded color emotions in subjects viewing uniform color (UC) samples. We conduct an experiment to measure and model how these color emotions change when texture is added to the color samples. Using a computer monitor, our subjects arrange samples along four scales: warm-cool,

  10. Texture & Textiles, Together

    Science.gov (United States)

    Guhin, Paula

    2011-01-01

    Creating a painting with texture is easy, although using heavy gel medium or modeling paste may be pricey ways to go about it. High school artists generally like making collages and mixed-media. In this article, the author suggests ways to capitalize on that interest with inexpensive fabric in a painting project.

  11. Chameleons: Reptilian Texture

    Science.gov (United States)

    Petersen, Hugh

    2009-01-01

    This article presents an art project inspired by a drawing of a chameleon the author saw in an art-supply catalog. Chameleons prove to be a good subject to highlight shape, color and texture with eigth-graders. In this project, middle- and high-school students draw a chameleon, learn how to use shapes to add to their chameleon drawing, learn how…

  12. Texture studies using neutron diffraction

    International Nuclear Information System (INIS)

    Szpunar, J.A.

    1984-01-01

    Various aspects of the application of neutron scattering methods to texture studies are reviewed. The neutron method is compared with other methods of texture measurement and techniques of neutron diffraction registration of texture are discussed. Examples are presented of the use of neutron scattering for texture examination in materials having various grain sizes and degrees of structural inhomogeneity. It is also demonstrated that the information about texture can be used in the discussion of the deformation and recrystallization processes in metals. Neutron diffraction results are shown to be helpful in the examination of the influence of texture on the anisotropy of physical properties in materials. The possibility of neutron diffraction measurements of magnetic texture is reported. Finally the accuracy of texture measurements using the neutron method is discussed. (author)

  13. Space-optimized texture atlases

    OpenAIRE

    Martínez Bayona, Jonàs

    2009-01-01

    Texture atlas parameterization provides an effective way to map a variety of colour and data attributes from 2D texture domains onto polygonal surface meshes. Most of the existing literature focus on how to build seamless texture atlases for continuous photometric detail, but little e ort has been devoted to devise e cient techniques for encoding self-repeating, uncontinuous signals such as building facades. We present a perception-based scheme for generating space-optimized texture ...

  14. Parallel-Sequential Texture Analysis

    NARCIS (Netherlands)

    van den Broek, Egon; Singh, Sameer; Singh, Maneesha; van Rikxoort, Eva M.; Apte, Chid; Perner, Petra

    2005-01-01

    Color induced texture analysis is explored, using two texture analysis techniques: the co-occurrence matrix and the color correlogram as well as color histograms. Several quantization schemes for six color spaces and the human-based 11 color quantization scheme have been applied. The VisTex texture

  15. Nonlinear operator for oriented texture

    NARCIS (Netherlands)

    Kruizinga, Peter; Petkov, Nikolay

    1999-01-01

    Texture is an important part of the visual world of animals and humans and their visual systems successfully detect, discriminate, and segment texture. Relatively recently progress was made concerning structures in the brain that are presumably responsible for texture processing. Neurophysiologists

  16. Widespread spin polarization effects in photoemission from topological insulators

    Energy Technology Data Exchange (ETDEWEB)

    Jozwiak, C.; Chen, Y. L.; Fedorov, A. V.; Analytis, J. G.; Rotundu, C. R.; Schmid, A. K.; Denlinger, J. D.; Chuang, Y.-D.; Lee, D.-H.; Fisher, I. R.; Birgeneau, R. J.; Shen, Z.-X.; Hussain, Z.; Lanzara, A.

    2011-06-22

    High-resolution spin- and angle-resolved photoemission spectroscopy (spin-ARPES) was performed on the three-dimensional topological insulator Bi{sub 2}Se{sub 3} using a recently developed high-efficiency spectrometer. The topological surface state's helical spin structure is observed, in agreement with theoretical prediction. Spin textures of both chiralities, at energies above and below the Dirac point, are observed, and the spin structure is found to persist at room temperature. The measurements reveal additional unexpected spin polarization effects, which also originate from the spin-orbit interaction, but are well differentiated from topological physics by contrasting momentum and photon energy and polarization dependencies. These observations demonstrate significant deviations of photoelectron and quasiparticle spin polarizations. Our findings illustrate the inherent complexity of spin-resolved ARPES and demonstrate key considerations for interpreting experimental results.

  17. Spin motive forces due to magnetic vortices and domain walls

    NARCIS (Netherlands)

    Lucassen, M.E.; Kruis, G.C.F.L.; Lavrijsen, R.; Swagten, H.J.M.; Koopmans, B.; Duine, R.A.

    2011-01-01

    We study spin motive forces, that is, spin-dependent forces and voltages induced by time-dependent magnetization textures, for moving magnetic vortices and domain walls. First, we consider the voltage generated by a one-dimensional field-driven domain wall. Next, we perform detailed calculations on

  18. Characterization of changes in potato tissue during cooking in relation to texture development

    NARCIS (Netherlands)

    Marle, van N.

    1997-01-01

    Texture of cooked potatoes is an important quality aspect. The diversity in texture types was sensory evaluated. Most of the differences between texture types could be explained by differences between mealy and non-mealy characteristics. Furthermore, cultivars with similar mealy/non-mealy

  19. Spin interferometry in anisotropic spin-orbit fields

    Science.gov (United States)

    Saarikoski, Henri; Reynoso, Andres A.; Baltanás, José Pablo; Frustaglia, Diego; Nitta, Junsaku

    2018-03-01

    Electron spins in a two-dimensional electron gas can be manipulated by spin-orbit (SO) fields originating from either Rashba or Dresselhaus interactions with independent isotropic characteristics. Together, though, they produce anisotropic SO fields with consequences on quantum transport through spin interference. Here we study the transport properties of modeled mesoscopic rings subject to Rashba and Dresselhaus [001] SO couplings in the presence of an additional in-plane Zeeman field acting as a probe. By means of one- and two-dimensional quantum transport simulations we show that this setting presents anisotropies in the quantum resistance as a function of the Zeeman field direction. Moreover, the anisotropic resistance can be tuned by the Rashba strength up to the point to invert its response to the Zeeman field. We also find that a topological transition in the field texture that is associated with a geometric phase switching is imprinted in the anisotropy pattern. We conclude that resistance anisotropy measurements can reveal signatures of SO textures and geometric phases in spin carriers.

  20. Spin current

    CERN Document Server

    Valenzuela, Sergio O; Saitoh, Eiji; Kimura, Takashi

    2017-01-01

    Since the discovery of the giant magnetoresistance effect in magnetic multilayers in 1988, a new branch of physics and technology, called spin-electronics or spintronics, has emerged, where the flow of electrical charge as well as the flow of electron spin, the so-called “spin current,” are manipulated and controlled together. The physics of magnetism and the application of spin current have progressed in tandem with the nanofabrication technology of magnets and the engineering of interfaces and thin films. This book aims to provide an introduction and guide to the new physics and applications of spin current, with an emphasis on the interaction between spin and charge currents in magnetic nanostructures.

  1. Spin Electronics

    Science.gov (United States)

    2003-08-01

    applications, a ferromagnetic metal may be used as a source of spin-polarized electronics to be injected into a semiconductor, a superconductor or a...physical phenomena in II-VI and III-V semiconductors. In II-VI systems, the Mn2+ ions act to boost the electron spin precession up to terahertz ...conductors, proximity effect between ferromagnets and superconductors , and the effects of spin injection on the physical properties of the

  2. Spin doctoring

    OpenAIRE

    Vozková, Markéta

    2011-01-01

    1 ABSTRACT The aim of this text is to provide an analysis of the phenomenon of spin doctoring in the Euro-Atlantic area. Spin doctors are educated people in the fields of semiotics, cultural studies, public relations, political communication and especially familiar with the infrastructure and the functioning of the media industry. Critical reflection of manipulative communication techniques puts spin phenomenon in historical perspective and traces its practical use in today's social communica...

  3. Seismic texture classification. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Vinther, R.

    1997-12-31

    The seismic texture classification method, is a seismic attribute that can both recognize the general reflectivity styles and locate variations from these. The seismic texture classification performs a statistic analysis for the seismic section (or volume) aiming at describing the reflectivity. Based on a set of reference reflectivities the seismic textures are classified. The result of the seismic texture classification is a display of seismic texture categories showing both the styles of reflectivity from the reference set and interpolations and extrapolations from these. The display is interpreted as statistical variations in the seismic data. The seismic texture classification is applied to seismic sections and volumes from the Danish North Sea representing both horizontal stratifications and salt diapers. The attribute succeeded in recognizing both general structure of successions and variations from these. Also, the seismic texture classification is not only able to display variations in prospective areas (1-7 sec. TWT) but can also be applied to deep seismic sections. The seismic texture classification is tested on a deep reflection seismic section (13-18 sec. TWT) from the Baltic Sea. Applied to this section the seismic texture classification succeeded in locating the Moho, which could not be located using conventional interpretation tools. The seismic texture classification is a seismic attribute which can display general reflectivity styles and deviations from these and enhance variations not found by conventional interpretation tools. (LN)

  4. Texture Enhanced Appearance Models

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Stegmann, Mikkel Bille; Darkner, Sune

    2007-01-01

    Statistical region-based registration methods such as the Active Appearance Model (AAM) are used for establishing dense correspondences in images. At low resolution, images correspondences can be recovered reliably in real-time. However, as resolution increases this becomes infeasible due...... to excessive storage and computational requirements. We propose to reduce the dimensionality of the textural components by selecting a subset of basis functions from a larger dictionary, estimate regression splines and model only the coeffcients of the retained basis functions. We demonstrate the use of two...

  5. Spin glasses

    CERN Document Server

    Bovier, Anton

    2007-01-01

    Spin glass theory is going through a stunning period of progress while finding exciting new applications in areas beyond theoretical physics, in particular in combinatorics and computer science. This collection of state-of-the-art review papers written by leading experts in the field covers the topic from a wide variety of angles. The topics covered are mean field spin glasses, including a pedagogical account of Talagrand's proof of the Parisi solution, short range spin glasses, emphasizing the open problem of the relevance of the mean-field theory for lattice models, and the dynamics of spin glasses, in particular the problem of ageing in mean field models. The book will serve as a concise introduction to the state of the art of spin glass theory, usefull to both graduate students and young researchers, as well as to anyone curious to know what is going on in this exciting area of mathematical physics.

  6. Spin-Orbitronics at Transition Metal Interfaces

    KAUST Repository

    Manchon, Aurelien

    2017-11-09

    The presence of large spin–orbit interaction at transition metal interfaces enables the emergence of a variety of fascinating phenomena that have been at the forefront of spintronics research in the past 10 years. The objective of the present chapter is to offer a review of these various effects from a theoretical perspective, with a particular focus on spin transport, chiral magnetism, and their interplay. After a brief description of the orbital hybridization scheme at transition metal interfaces, we address the impact of spin–orbit coupling on the interfacial magnetic configuration, through the celebrated Dzyaloshinskii–Moriya interaction. We then discuss the physics of spin transport and subsequent torques occurring at these interfaces. We particularly address the spin Hall, spin swapping, and inverse spin-galvanic effects. Finally, the interplay between flowing charges and chiral magnetic textures and their induced dynamics are presented. We conclude this chapter by proposing some perspectives on promising research directions.

  7. Textural characterization of coals using fractal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mahamud, Manuel; Lopez, Oscar [Faculty of Chemistry, Department of Chemical and Environmental Engineering, University of Oviedo, Campus de El Cristo, 33071 Oviedo (Spain); Pis, Jose Juan; Pajares, Jesus Alberto [Instituto Nacional del Carbon (C.S.I.C.), Apartado 73, 33080 Oviedo (Spain)

    2003-05-15

    The aim of this study is to show how fractal analysis can be effectively used to characterize the texture of porous solids. The materials under study were series of coals oxidized in air at various temperatures for different time intervals. Data from mercury porosimetry determinations of samples was analyzed using fractal models. The methods employed were those proposed by Neimark, Friesen and Mikula and that developed by Zhang and Li. Some methods are able to supply a fractal profile or 'fractal fingerprint' of materials, i.e. ranges of pore sizes with different fractal dimensions are detected. These fractal profiles are very sensitive to the oxidation treatment. The average fractal dimension can also be used as a valid parameter to monitor the textural evolution of the coals as the treatment progresses, as this behaves in a similar way to other textural parameters. The use of fractal analysis in conjunction with the results of classical characterization methods leads to a better understanding of textural modifications in the processing of materials.

  8. Efficient rolling texture predictions and texture-sensitive thermomechanical properties of α-uranium foils

    Science.gov (United States)

    Steiner, Matthew A.; Klein, Robert W.; Calhoun, Christopher A.; Knezevic, Marko; Garlea, Elena; Agnew, Sean R.

    2017-11-01

    Finite element (FE) analysis was used to simulate the strain history of an α-uranium foil during cold straight-rolling, with the sheet modeled as an isotropic elastoplastic continuum. The resulting strain history was then used as input for a viscoplastic self-consistent (VPSC) polycrystal plasticity model to simulate crystallographic texture evolution. Mid-plane textures predicted via the combined FE→VPSC approach show alignment of the (010) poles along the rolling direction (RD), and the (001) poles along the normal direction (ND) with a symmetric splitting along RD. The surface texture is similar to that of the mid-plane, but with a shear-induced asymmetry that favors one of the RD split features of the (001) pole figure. Both the mid-plane and surface textures predicted by the FE→VPSC approach agree with published experimental results for cold straight-rolled α-uranium plates, as well as predictions made by a more computationally intensive full-field crystal plasticity based finite element model. α-uranium foils produced by cold-rolling must typically undergo a recrystallization anneal to restore ductility prior to their final application, resulting in significant texture evolution from the cold-rolled plate deformation texture. Using the texture measured from a foil in the final recrystallized state, coefficients of thermal expansion and the elastic stiffness tensors were calculated using a thermo-elastic self-consistent model, and the anisotropic yield loci and flow curves along the RD, TD, and ND were predicted using the VPSC code.

  9. Tape Textured Works of Art

    Science.gov (United States)

    Skophammer, Karen

    2009-01-01

    Texture is how things feel or how they look as though they might feel if one touches them. Some surfaces are rough and some are smooth to the touch. There are many other words, such as bumpy, used to describe texture when one feels or sees it. This article presents an art project in which elementary students explain how texture is used in art,…

  10. Texture determination by neutron diffraction

    International Nuclear Information System (INIS)

    Dervin, P.

    1981-02-01

    Application of neutron diffraction to crystallographic texture determination shows many advantages: possibility of an important grain size, the quantity of material contributing to diffraction is more important than with X rays, good accuracy and complete pole figures are obtained by transmission only eliminating corrections needed with X rays. Texture determination allows control and improvement of material quality. Texture studies give good informations on mechanisms occuring in deformation or recrystallization of polycrystals and on anisotropy of physical and mechanical properties [fr

  11. TOPICAL REVIEW: Spin current, spin accumulation and spin Hall effect

    Directory of Open Access Journals (Sweden)

    Saburo Takahashi and Sadamichi Maekawa

    2008-01-01

    Full Text Available Nonlocal spin transport in nanostructured devices with ferromagnetic injector (F1 and detector (F2 electrodes connected to a normal conductor (N is studied. We reveal how the spin transport depends on interface resistance, electrode resistance, spin polarization and spin diffusion length, and obtain the conditions for efficient spin injection, spin accumulation and spin current in the device. It is demonstrated that the spin Hall effect is caused by spin–orbit scattering in nonmagnetic conductors and gives rise to the conversion between spin and charge currents in a nonlocal device. A method of evaluating spin–orbit coupling in nonmagnetic metals is proposed.

  12. Wavelet transform analysis of chromatin texture changes during heat shock.

    Science.gov (United States)

    Herbomel, G; Grichine, A; Fertin, A; Delon, A; Vourc'h, C; Souchier, C; Usson, Y

    2016-06-01

    Texture analysis can be a useful tool to investigate the organization of chromatin. Approaches based on multiscale analysis and in particular the 'à trou' wavelet analysis has already been used for microscopy (Olivo Marin). In order to analyse texture changes, the statistical properties of the wavelet coefficient images were summarized by the first four statistical orders: mean, standard deviation, skewness and kurtosis of the coefficient image histogram. The 'à trou' transform provided a representation of the wavelet coefficients and texture parameters with the same statistical robustness throughout the scale spaces. It was applied for quantifying chromatin texture and heat-induced chromatin changes in living cells. We investigated the changes by both laser scanning and spinning disk confocal microscopies and compared the texture parameters before and after increasing duration of heat shock exposure (15 min, 30 min and 1 h). Furthermore, as activation of the heat shock response also correlates with a rapid localization of HSF1 within a few nuclear structures termed nuclear stress bodies (nSBs), we compared the dynamics of nSBs formation with that of textural changes during 1 h of continuous heat shock. Next, we studied the recovery phase following a 1-h heat shock. Significant differences were observed, particularly affecting the perinucleolar region, even for the shortest heat shock time affecting mostly the skewness and standard deviation. Furthermore, progressive changes could be observed according to the duration of heat shock, mostly affecting fine details (pixel-wise changes) as revealed by the parameters, obtained from the first- and second-order wavelet coefficients. 'A trou' wavelet texture analysis provided a sensitive and efficient tool to investigate minute changes of chromatin. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  13. Spin electronics

    CERN Document Server

    Buhrman, Robert; Daughton, James; Molnár, Stephan; Roukes, Michael

    2004-01-01

    This report is a comparative review of spin electronics ("spintronics") research and development activities in the United States, Japan, and Western Europe conducted by a panel of leading U.S. experts in the field. It covers materials, fabrication and characterization of magnetic nanostructures, magnetism and spin control in magnetic nanostructures, magneto-optical properties of semiconductors, and magnetoelectronics and devices. The panel's conclusions are based on a literature review and a series of site visits to leading spin electronics research centers in Japan and Western Europe. The panel found that Japan is clearly the world leader in new material synthesis and characterization; it is also a leader in magneto-optical properties of semiconductor devices. Europe is strong in theory pertaining to spin electronics, including injection device structures such as tunneling devices, and band structure predictions of materials properties, and in development of magnetic semiconductors and semiconductor heterost...

  14. Spin glasses

    International Nuclear Information System (INIS)

    Fischer, K.H.; Hertz, J.A.

    1993-01-01

    Spin glasses, simply defined by the authors as a collection of spins (i.e., magnetic moments) whose low-temperature state is a frozen disordered one, represent one of the fascinating new fields of study in condensed matter physics, and this book is the first to offer a comprehensive account of the subject. Included are discussions of the most important developments in theory, experimental work, and computer modeling of spin glasses, all of which have taken place essentially within the last two decades. The first part of the book gives a general introduction to the basic concepts and a discussion of mean field theory, while the second half concentrates on experimental results, scaling theory, and computer simulation of the structure of spin glasses

  15. Quantitative Characterisation of Surface Texture

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Lonardo, P.M.; Trumpold, H.

    2000-01-01

    This paper reviews the different methods used to give a quantitative characterisation of surface texture. The paper contains a review of conventional 2D as well as 3D roughness parameters, with particular emphasis on recent international standards and developments. It presents new texture...

  16. Emotional effects of dynamic textures

    NARCIS (Netherlands)

    Toet, A.; Henselmans, M.; Lucassen, M.P.; Gevers, T.

    2011-01-01

    This study explores the effects of various spatiotemporal dynamic texture characteristics on human emotions. The emotional experience of auditory (eg, music) and haptic repetitive patterns has been studied extensively. In contrast, the emotional experience of visual dynamic textures is still largely

  17. Cartoon+Texture Image Decomposition

    Directory of Open Access Journals (Sweden)

    Antoni Buades

    2011-09-01

    Full Text Available In this article we give a thorough description of the algorithm proposed in [A. Buades, T. Le, J.M. Morel and L. Vese, Fast cartoon + texture image filters, IEEE Transactions on Image Processing, 2010] for cartoon+texture decomposition using of a nonlinear low pass-high pass filter pair.

  18. Human versus artificial texture perception

    NARCIS (Netherlands)

    Petiet, Peter J.; van Erp, J.; Drullman, R.; van den Broek, Egon; Beintema, J.; van Wijngaarden, S.

    2006-01-01

    The performances of current texture analysis algorithms are still poor, especially when applied to a large, diffuse texture domain. Most of these purely computationally driven techniques are created to function within a highly restricted domain. When applied as computer vision techniques, frequently

  19. Emotional Effects of Dynamic Textures

    Directory of Open Access Journals (Sweden)

    Alexander Toet

    2011-12-01

    Full Text Available This study explores the effects of various spatiotemporal dynamic texture characteristics on human emotions. The emotional experience of auditory (eg, music and haptic repetitive patterns has been studied extensively. In contrast, the emotional experience of visual dynamic textures is still largely unknown, despite their natural ubiquity and increasing use in digital media. Participants watched a set of dynamic textures, representing either water or various different media, and self-reported their emotional experience. Motion complexity was found to have mildly relaxing and nondominant effects. In contrast, motion change complexity was found to be arousing and dominant. The speed of dynamics had arousing, dominant, and unpleasant effects. The amplitude of dynamics was also regarded as unpleasant. The regularity of the dynamics over the textures' area was found to be uninteresting, nondominant, mildly relaxing, and mildly pleasant. The spatial scale of the dynamics had an unpleasant, arousing, and dominant effect, which was larger for textures with diverse content than for water textures. For water textures, the effects of spatial contrast were arousing, dominant, interesting, and mildly unpleasant. None of these effects were observed for textures of diverse content. The current findings are relevant for the design and synthesis of affective multimedia content and for affective scene indexing and retrieval.

  20. Computational modeling of ring textures in mesophase carbon fibers

    Directory of Open Access Journals (Sweden)

    de Andrade Lima Luiz Rogério Pinho

    2003-01-01

    Full Text Available Carbon fibers are widely used in many industrial applications due the fact of their excellent properties. Carbonaceous mesophases are liquid crystalline precursor materials that can be spun into high performance carbon fibers using the melt spinning process, which is a flow cascade consisting of pressure driven flow-converging die flow-free surface extensional spinline flow that modifies the precursor molecular orientation structure. Carbon fiber property optimization requires a better understanding of the principles that control the structure development during the fiber formation processes and the rheological processing properties. This paper presents the elastic and continuum theory of liquid crystalsand computer simulations of structure formation for pressure-driven flow of carbonaceous liquid crystalline precursors used in the industrial carbon fiber spinning process. The simulations results capture the formation of characteristic fiber macro-textures and provide new knowledge on the role of viscous and elastic effects in the spinning process.

  1. Polar-core spin vortex of quasi-2D ferromagnetic spin-1 condensate in a flat-bottomed optical trap with a weak magnetic field

    Science.gov (United States)

    Zheng, Gong-Ping; Li, Pin; Li, Ting; Xue, Ya-Jie

    2018-02-01

    Motivated by the recent experiments realized in a flat-bottomed optical trap (Navon et al., 2015; Chomaz et al., 2015), we study the ground state of polar-core spin vortex of quasi-2D ferromagnetic spin-1 condensate in a finite-size homogeneous trap with a weak magnetic field. The exact spatial distribution of local spin is obtained with a variational method. Unlike the fully-magnetized planar spin texture with a zero-spin core, which was schematically demonstrated in previous studies for the ideal polar-core spin vortex in a homogeneous trap with infinitely large boundary, some plateaus and two-cores structure emerge in the distribution curves of spin magnitude in the polar-core spin vortex we obtained for the larger effective spin-dependent interaction. More importantly, the spin values of the plateaus are not 1 as expected in the fully-magnetized spin texture, except for the sufficiently large spin-dependent interaction and the weak-magnetic-field limit. We attribute the decrease of spin value to the effect of finite size of the system. The spin values of the plateaus can be controlled by the quadratic Zeeman energy q of the weak magnetic field, which decreases with the increase of q.

  2. Spin texture motion in antiferromagnetic and ferromagnetic nanowires

    Czech Academy of Sciences Publication Activity Database

    Rodrigues, D.R.; Everschor-Sitte, K.; Tretiakov, O.A.; Sinova, Jairo; Abanov, A.

    2017-01-01

    Roč. 95, č. 17 (2017), s. 1-7, č. článku 174408. ISSN 2469-9950 R&D Projects: GA ČR GB14-37427G EU Projects: European Commission(XE) 610115 - SC2 Institutional support: RVO:68378271 Keywords : orbit torques * magnetization * spintronics Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.836, year: 2016

  3. Texture dependent lattice strains and texture gradient in AI7020

    Science.gov (United States)

    Y Zhong, Z.; Brokmeier, H.-G.; Maawad, E.; Schell, N.

    2015-04-01

    Firstly, an Al7020 block was characterized by the texture gradient, which was remarkably strong. Texture sharpness in the center with about 30 mrd (multiple random distribution) shows typical plain strain texture components. On the surface and close to the surface the texture sharpness is much weaker showing also shear components. Strongest shear was not directly at the surface but 4 mm deeper. The texture analysis at HEMS Beamline (Petra III/DESY-Hamburg) was done with continuous scanning mode to include all grains to improve the grain statistics. Secondly, with an in situ synchrotron experiment the texture dependent lattice strain behavior was investigated using flat tensile samples oriented 0°, 45° and 90° to the rolling direction (RD). Texture induced anisotropy influenced on the lattice dependent yield strength and the lattice dependent stress-strain behavior, which will be discussed in detail. Due to the high energy synchrotron beam complete Debye-Scherrer rings were obtained so that the patterns, parallel and perpendicular to loading direction (LD), were obtained simultaneously.

  4. Spin transfer and spin pumping in disordered normal metal-antiferromagnetic insulator systems

    Science.gov (United States)

    Gulbrandsen, Sverre A.; Brataas, Arne

    2018-02-01

    We consider an antiferromagnetic insulator that is in contact with a metal. Spin accumulation in the metal can induce spin-transfer torques on the staggered field and on the magnetization in the antiferromagnet. These torques relate to spin pumping: the emission of spin currents into the metal by a precessing antiferromagnet. We investigate how the various components of the spin-transfer torque are affected by spin-independent disorder and spin-flip scattering in the metal. Spin-conserving disorder reduces the coupling between the spins in the antiferromagnet and the itinerant spins in the metal in a manner similar to Ohm's law. Spin-flip scattering leads to spin-memory loss with a reduced spin-transfer torque. We discuss the concept of a staggered spin current and argue that it is not a conserved quantity. Away from the interface, the staggered spin current varies around a 0 mean in an irregular manner. A network model explains the rapid decay of the staggered spin current.

  5. Spinning fluids reactor

    Science.gov (United States)

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

    2012-11-20

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

  6. Epitaxial hexagonal materials on IBAD-textured substrates

    Science.gov (United States)

    Matias, Vladimir; Yung, Christopher

    2017-08-15

    A multilayer structure including a hexagonal epitaxial layer, such as GaN or other group III-nitride (III-N) semiconductors, a oriented textured layer, and a non-single crystal substrate, and methods for making the same. The textured layer has a crystalline alignment preferably formed by the ion-beam assisted deposition (IBAD) texturing process and can be biaxially aligned. The in-plane crystalline texture of the textured layer is sufficiently low to allow growth of high quality hexagonal material, but can still be significantly greater than the required in-plane crystalline texture of the hexagonal material. The IBAD process enables low-cost, large-area, flexible metal foil substrates to be used as potential alternatives to single-crystal sapphire and silicon for manufacture of electronic devices, enabling scaled-up roll-to-roll, sheet-to-sheet, or similar fabrication processes to be used. The user is able to choose a substrate for its mechanical and thermal properties, such as how well its coefficient of thermal expansion matches that of the hexagonal epitaxial layer, while choosing a textured layer that more closely lattice matches that layer.

  7. Textures in Utopia Planitia

    Science.gov (United States)

    2002-01-01

    [figure removed for brevity, see original site] Bizarre textures cover the surface of eastern Utopia Planitia where there is a high probability that ground ice has played a role in the formation of this unusual landscape.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  8. Automatic Quality Measurement and Parameter Selection for Example-based Texture Synthesis

    DEFF Research Database (Denmark)

    Laursen, Lasse Farnung; Clemmensen, Line Katrine Harder; Bærentzen, Jakob Andreas

    synthesis compares to the original input. A good similarity measure will enable the search for the optimal texture synthesis parameters by maximizing the quality of the synthesis as a function of parameters. We apply presented methods to a state of the art texture synthesis algorithm, namely the one...... cover research to directly estimate specific texture synthesis parameters, such as patch size and iteration convergence, based on input textures. We also examine various similarity measures and evaluate their effectiveness. The goal for each measure is to properly evaluate how well the resulting...

  9. Symmetry realization of texture zeros

    International Nuclear Information System (INIS)

    Grimus, W.; Joshipura, A.S.; Lavoura, L.; Tanimoto, M.

    2004-01-01

    We show that it is possible to enforce texture zeros in arbitrary entries of the fermion mass matrices by means of Abelian symmetries; in this way, many popular mass-matrix textures find a symmetry justification. We propose two alternative methods which allow one to place zeros in any number of elements of the mass matrices that one wants. They are applicable simultaneously in the quark and lepton sectors. They are also applicable in grand unified theories. The number of scalar fields required by our methods may be large; still, in many interesting cases this number can be reduced considerably. The larger the desired number of texture zeros is, the simpler are the models which reproduce the texture. (orig.)

  10. Real-time texture experiments

    International Nuclear Information System (INIS)

    Juul Jensen, D.

    1985-01-01

    A technique for fast in-situ texture determination by neutron diffraction is described. The basic instrument is variable wavelength neutron spectrometer modified to incorporate a linear position-sensitive detector and a fully automatic Eulergoniometer. At present a complete textural analysis with an accuracy of 2-3% determined by counting statistics, requires from 15 to 30 minutes measuring time depending on the sample material. By on-line recording of the change in texture, which commonly accompanies such processes as deformation, recrystallization and grain growth in crystalline materials, information about the process and its kinetics is obtained. This is illustrated by in-situ kinetic investigations of recrystallization and grain growth in various polycrystalline metals; the potential of the technique for problems related to metallurgical practice is demonstrated by an approach of texture tailoring in commercially pure aluminium. (author)

  11. EUROMET SUPPLEMENTARY COMPARISON - SURFACE TEXTURE

    DEFF Research Database (Denmark)

    Koenders, L.; Andreasen, Jan Lasson; De Chiffre, Leonardo

    At the length meeting in Prague in Oct. 1999 a new comparison was suggested on surface texture. The last comparison on this field was finished in 1989. In the meantime the instrumentation, the standards and the written standards have been improved including some software filters. The pilot...... laboratories for this supplementary comparison on surface texture are the Centre for Geometrical Metrology at the Technical University of Denmark and the Micro- and Nanotopography laboratory at the Physikalisch-Technische Bundesanstalt, Germany....

  12. Spin Transport in a Unitary Fermi Gas

    Science.gov (United States)

    Thywissen, Joseph

    2015-03-01

    We study spin transport in a quantum degenerate Fermi gas of 40K near an s-wave interaction resonance. The starting point of our measurements is a transversely spin-polarized gas, where each atom is in a superposition of the lowest two Zeeman eigenstates. In the presence of an external gradient, a spin texture develops across the cloud, which drives diffusive spin currents. Spin transport is described with two coefficients: D0⊥, the transverse spin diffusivity, and γ, the Leggett-Rice parameter. Diffusion is a dissipative effect that increases the entropy of the gas, eventually creating a mixture of spin states. γ parameterizes the rate at which spin current precesses around the local magnetization. Using a spin-echo sequence, we measure these transport parameters for a range of interaction strengths and temperatures. At unitarity, for a normal-state gas initially at one fifth of the Fermi temperature, we find D0⊥ = 2 . 3 (4) ℏ / m and γ = 1 . 08 (9) , where m is the atomic mass. In the limit of zero temperature, γ and D0⊥ are scale-invariant universal parameters of the unitary Fermi gas. The value of D0⊥ reveals strong scattering and is near its proposed quantum limit, such that the inferred value of the transport lifetime τ⊥ is comparable to ℏ /ɛF . This raises the possibility that incoherent transport may play a role. The nonzero value of γ tells us that spin waves in unitary Fermi gas are dispersive, or in other words, that the gas has a spin stiffness in the long-wavelength limit. Time permitting, we will also discuss a time-resolved measurement of the contact, through which we observe the microscopic transformation of the gas from ideal to strongly correlated.

  13. Photoemission of Bi_{2}Se_{3} with Circularly Polarized Light: Probe of Spin Polarization or Means for Spin Manipulation?

    Directory of Open Access Journals (Sweden)

    J. Sánchez-Barriga

    2014-03-01

    Full Text Available Topological insulators are characterized by Dirac-cone surface states with electron spins locked perpendicular to their linear momenta. Recent theoretical and experimental work implied that this specific spin texture should enable control of photoelectron spins by circularly polarized light. However, these reports questioned the so far accepted interpretation of spin-resolved photoelectron spectroscopy. We solve this puzzle and show that vacuum ultraviolet photons (50–70 eV with linear or circular polarization indeed probe the initial-state spin texture of Bi_{2}Se_{3} while circularly polarized 6-eV low-energy photons flip the electron spins out of plane and reverse their spin polarization, with its sign determined by the light helicity. Our photoemission calculations, taking into account the interplay between the varying probing depth, dipole-selection rules, and spin-dependent scattering effects involving initial and final states, explain these findings and reveal proper conditions for light-induced spin manipulation. Our results pave the way for future applications of topological insulators in optospintronic devices.

  14. Interference Spins

    DEFF Research Database (Denmark)

    Popovski, Petar; Simeone, Osvaldo; Nielsen, Jimmy Jessen

    2015-01-01

    on traffic load and interference condition leads to performance gains. In this letter, a general network of multiple interfering two-way links is studied under the assumption of a balanced load in the two directions for each link. Using the notion of interference spin, we introduce an algebraic framework...

  15. Spinning worlds

    NARCIS (Netherlands)

    Schwarz, H.

    2017-01-01

    The thesis "Spinning Worlds" is about the characterisation of two types of gas-giant exoplanets: Hot Jupiters, with orbital periods of fewer than five days, and young, wide-orbit gas giants, with orbital periods as long as thousands of years. The thesis is based on near-infrared observations of 1

  16. Conjoint representation of texture ensemble and location in the parahippocampal place area.

    Science.gov (United States)

    Park, Jeongho; Park, Soojin

    2017-04-01

    Texture provides crucial information about the category or identity of a scene. Nonetheless, not much is known about how the texture information in a scene is represented in the brain. Previous studies have shown that the parahippocampal place area (PPA), a scene-selective part of visual cortex, responds to simple patches of texture ensemble. However, in natural scenes textures exist in spatial context within a scene. Here we tested two hypotheses that make different predictions on how textures within a scene context are represented in the PPA. The Texture-Only hypothesis suggests that the PPA represents texture ensemble (i.e., the kind of texture) as is, irrespective of its location in the scene. On the other hand, the Texture and Location hypothesis suggests that the PPA represents texture and its location within a scene (e.g., ceiling or wall) conjointly. We tested these two hypotheses across two experiments, using different but complementary methods. In experiment 1 , by using multivoxel pattern analysis (MVPA) and representational similarity analysis, we found that the representational similarity of the PPA activation patterns was significantly explained by the Texture-Only hypothesis but not by the Texture and Location hypothesis. In experiment 2 , using a repetition suppression paradigm, we found no repetition suppression for scenes that had the same texture ensemble but differed in location (supporting the Texture and Location hypothesis). On the basis of these results, we propose a framework that reconciles contrasting results from MVPA and repetition suppression and draw conclusions about how texture is represented in the PPA. NEW & NOTEWORTHY This study investigates how the parahippocampal place area (PPA) represents texture information within a scene context. We claim that texture is represented in the PPA at multiple levels: the texture ensemble information at the across-voxel level and the conjoint information of texture and its location at the within

  17. Audio Classification from Time-Frequency Texture

    OpenAIRE

    Yu, Guoshen; Slotine, Jean-Jacques

    2008-01-01

    Time-frequency representations of audio signals often resemble texture images. This paper derives a simple audio classification algorithm based on treating sound spectrograms as texture images. The algorithm is inspired by an earlier visual classification scheme particularly efficient at classifying textures. While solely based on time-frequency texture features, the algorithm achieves surprisingly good performance in musical instrument classification experiments.

  18. Food Texture Preferences in Infants Versus Toddlers.

    Science.gov (United States)

    Lundy, Brenda; And Others

    1998-01-01

    Compared food texture preferences during infancy and toddlerhood. Found that infants displayed more negative expressions and head and body movements in response to complex textures than to simple textures. Toddlers displayed more positive head and body movements and more eagerness in response to complex than to simple textures. Experience with…

  19. Competing Spin Liquids and Hidden Spin-Nematic Order in Spin Ice with Frustrated Transverse Exchange

    Directory of Open Access Journals (Sweden)

    Mathieu Taillefumier

    2017-12-01

    Full Text Available Frustration in magnetic interactions can give rise to disordered ground states with subtle and beautiful properties. The spin ices Ho_{2}Ti_{2}O_{7} and Dy_{2}Ti_{2}O_{7} exemplify this phenomenon, displaying a classical spin-liquid state, with fractionalized magnetic-monopole excitations. Recently, there has been great interest in closely related “quantum spin-ice” materials, following the realization that anisotropic exchange interactions could convert spin ice into a massively entangled, quantum spin liquid, where magnetic monopoles become the charges of an emergent quantum electrodynamics. Here we show that even the simplest model of a quantum spin ice, the XXZ model on the pyrochlore lattice, can realize a still-richer scenario. Using a combination of classical Monte Carlo simulation, semiclassical molecular-dynamics simulation, and analytic field theory, we explore the properties of this model for frustrated transverse exchange. We find not one, but three competing forms of spin liquid, as well as a phase with hidden, spin-nematic order. We explore the experimental signatures of each of these different states, making explicit predictions for inelastic neutron scattering. These results show an intriguing similarity to experiments on a range of pyrochlore oxides.

  20. Competing Spin Liquids and Hidden Spin-Nematic Order in Spin Ice with Frustrated Transverse Exchange

    Science.gov (United States)

    Taillefumier, Mathieu; Benton, Owen; Yan, Han; Jaubert, L. D. C.; Shannon, Nic

    2017-10-01

    Frustration in magnetic interactions can give rise to disordered ground states with subtle and beautiful properties. The spin ices Ho2 Ti2 O7 and Dy2 Ti2 O7 exemplify this phenomenon, displaying a classical spin-liquid state, with fractionalized magnetic-monopole excitations. Recently, there has been great interest in closely related "quantum spin-ice" materials, following the realization that anisotropic exchange interactions could convert spin ice into a massively entangled, quantum spin liquid, where magnetic monopoles become the charges of an emergent quantum electrodynamics. Here we show that even the simplest model of a quantum spin ice, the XXZ model on the pyrochlore lattice, can realize a still-richer scenario. Using a combination of classical Monte Carlo simulation, semiclassical molecular-dynamics simulation, and analytic field theory, we explore the properties of this model for frustrated transverse exchange. We find not one, but three competing forms of spin liquid, as well as a phase with hidden, spin-nematic order. We explore the experimental signatures of each of these different states, making explicit predictions for inelastic neutron scattering. These results show an intriguing similarity to experiments on a range of pyrochlore oxides.

  1. On soil textural classifications and soil-texture-based estimations

    Science.gov (United States)

    Ángel Martín, Miguel; Pachepsky, Yakov A.; García-Gutiérrez, Carlos; Reyes, Miguel

    2018-02-01

    The soil texture representation with the standard textural fraction triplet sand-silt-clay is commonly used to estimate soil properties. The objective of this work was to test the hypothesis that other fraction sizes in the triplets may provide a better representation of soil texture for estimating some soil parameters. We estimated the cumulative particle size distribution and bulk density from an entropy-based representation of the textural triplet with experimental data for 6240 soil samples. The results supported the hypothesis. For example, simulated distributions were not significantly different from the original ones in 25 and 85 % of cases when the sand-silt-clay and very coarse+coarse + medium sand - fine + very fine sand - silt+clay were used, respectively. When the same standard and modified triplets were used to estimate the average bulk density, the coefficients of determination were 0.001 and 0.967, respectively. Overall, the textural triplet selection appears to be application and data specific.

  2. Auditory Perception of Statistically Blurred Sound Textures

    DEFF Research Database (Denmark)

    McWalter, Richard Ian; MacDonald, Ewen; Dau, Torsten

    Sound textures have been identified as a category of sounds which are processed by the peripheral auditory system and captured with running timeaveraged statistics. Although sound textures are temporally homogeneous, they offer a listener with enough information to identify and differentiate...... sources. This experiment investigated the ability of the auditory system to identify statistically blurred sound textures and the perceptual relationship between sound textures. Identification performance of statistically blurred sound textures presented at a fixed blur increased over those presented...

  3. Texture classification using logical operators.

    Science.gov (United States)

    Manian, V; Vasquez, R; Katiyar, P

    2000-01-01

    In this paper, a new algorithm for texture classification based on logical operators is presented. Operators constructed from logical building blocks are convolved with texture images. An optimal set of six operators are selected based on their texture discrimination ability. The responses are then converted to standard deviation matrices computed over a sliding window. Zonal sampling features are computed from these matrices. A feature selection process is applied and the new set of features are used for texture classification. Classification of several natural and synthetic texture images are presented demonstrating the excellent performance of the logical operator method. The computational superiority and classification accuracy of the algorithm is demonstrated by comparison with other popular methods. Experiments with different classifiers and feature normalization are also presented. The Euclidean distance classifier is found to perform best with this algorithm. The algorithm involves only convolutions and simple arithmetic in the various stages which allows faster implementations. The algorithm is applicable to different types of classification problems which is demonstrated by segmentation of remote sensing images, compressed and reconstructed images and industrial images.

  4. Spin flexoelectricity and chiral spin structures in magnetic films

    International Nuclear Information System (INIS)

    Pyatakov, A.P.; Sergeev, A.S.; Mikailzade, F.A.; Zvezdin, A.K.

    2015-01-01

    In this short review a broad range of chiral phenomena observed in magnetic films (spin cycloid and skyrmion structures formation as well as chirality dependent domain wall motion) is considered under the perspective of spin flexoelectricity, i.e. the relation between bending of magnetization pattern and electric polarization. The similarity and the difference between the spin flexoelectricity and the newly emerged notion of spin flexomagnetism are discussed. The phenomenological arguments based on the geometrical idea of curvature-induced effects are supported by analysis of the microscopic mechanisms of spin flexoelectricity based on three-site ion indirect exchange and twisted RKKY interaction models. - Highlights: • Magnetic structure formation in thin films is analogous to flexoelectric phenomena in crystals. • The microscopic mechanism of spin flexoelectricity is the antisymmetric exchange. • Spin cycloid in thin film of metals can be the result of Rashba interaction in 2DEG. • The chirality-dependent Néel-type magnetic domain wall motion is observed in electric field

  5. Spin flexoelectricity and chiral spin structures in magnetic films

    Energy Technology Data Exchange (ETDEWEB)

    Pyatakov, A.P., E-mail: pyatakov@physics.msu.ru [M.V. Lomonosov Moscow State University, Leninskie gori, Moscow 119991 (Russian Federation); Sergeev, A.S. [M.V. Lomonosov Moscow State University, Leninskie gori, Moscow 119991 (Russian Federation); Mikailzade, F.A. [Department of Physics, Gebze Technical University, Gebze, 41400 Kocaeli (Turkey); Zvezdin, A.K. [A.M. Prokhorov General Physics Institute, Vavilova St., 38, Moscow 119991 (Russian Federation)

    2015-06-01

    In this short review a broad range of chiral phenomena observed in magnetic films (spin cycloid and skyrmion structures formation as well as chirality dependent domain wall motion) is considered under the perspective of spin flexoelectricity, i.e. the relation between bending of magnetization pattern and electric polarization. The similarity and the difference between the spin flexoelectricity and the newly emerged notion of spin flexomagnetism are discussed. The phenomenological arguments based on the geometrical idea of curvature-induced effects are supported by analysis of the microscopic mechanisms of spin flexoelectricity based on three-site ion indirect exchange and twisted RKKY interaction models. - Highlights: • Magnetic structure formation in thin films is analogous to flexoelectric phenomena in crystals. • The microscopic mechanism of spin flexoelectricity is the antisymmetric exchange. • Spin cycloid in thin film of metals can be the result of Rashba interaction in 2DEG. • The chirality-dependent Néel-type magnetic domain wall motion is observed in electric field.

  6. In a spin at Brookhaven spin physics

    CERN Document Server

    Makdisi, Y I

    2003-01-01

    The mysterious quantity that is spin took centre stage at Brookhaven for the SPIN2002 meeting last September. The 15th biennial International Spin Physics Symposium (SPIN2002) was held at Brookhaven National Laboratory on 9-14 September 2002. Some 250 spin enthusiasts attended, including experimenters and theorists in both nuclear and high-energy physics, as well as accelerator physicists and polarized target and polarized source experts. The six-day symposium included 23 plenary talks and 150 parallel talks. SPIN2002 was preceded by a one-day spin physics tutorial for students, postdocs, and anyone else who felt the need for a refresher course. (2 refs).

  7. Spin-Circuit Representation of Spin Pumping

    Science.gov (United States)

    Roy, Kuntal

    2017-07-01

    Circuit theory has been tremendously successful in translating physical equations into circuit elements in an organized form for further analysis and proposing creative designs for applications. With the advent of new materials and phenomena in the field of spintronics and nanomagnetics, it is imperative to construct the spin-circuit representations for different materials and phenomena. Spin pumping is a phenomenon by which a pure spin current can be injected into the adjacent layers. If the adjacent layer is a material with a high spin-orbit coupling, a considerable amount of charge voltage can be generated via the inverse spin Hall effect allowing spin detection. Here we develop the spin-circuit representation of spin pumping. We then combine it with the spin-circuit representation for the materials having spin Hall effect to show that it reproduces the standard results as in the literature. We further show how complex multilayers can be analyzed by simply writing a netlist.

  8. Spin correlations and spin-wave excitations in Dirac-Weyl semimetals

    Science.gov (United States)

    Araki, Yasufumi; Nomura, Kentaro

    We study correlations among magnetic dopants in three-dimensional Dirac and Weyl semimetals. Effective field theory for localized magnetic moments is derived by integrating out the itinerant electron degrees of freedom. We find that spin correlation in the spatial direction parallel to local magnetization is more rigid than that in the perpendicular direction, reflecting spin-momentum locking nature of the Dirac Hamiltonian. Such an anisotropy becomes stronger for Fermi level close to the Dirac points, due to Van Vleck paramagnetism triggered by spin-orbit coupling. One can expect topologically nontrivial spin textures under this anisotropy, such as a hedgehog around a single point, or a radial vortex around an axis, as well as a uniform ferromagnetic order. We further investigate the characteristics of spin waves in the ferromagnetic state. Spin-wave dispersion also shows a spatial anisotropy, which is less dispersed in the direction transverse to the magnetization than that in the longitudinal direction. The spin-wave dispersion anisotropy can be traced back to the rigidity and flexibility of spin correlations discussed above. This work was supported by Grant-in-Aid for Scientific Research (Grants No.15H05854, No.26107505, and No.26400308) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan.

  9. Spin Coherence in Semiconductor Nanostructures

    National Research Council Canada - National Science Library

    Flatte, Michael E

    2006-01-01

    ... dots, tuning of spin coherence times for electron spin, tuning of dipolar magnetic fields for nuclear spin, spontaneous spin polarization generation and new designs for spin-based teleportation and spin transistors...

  10. Di-uniform texture spaces

    Directory of Open Access Journals (Sweden)

    Selma Ozcag

    2003-04-01

    Full Text Available Textures were introduced by the second author as a point-based setting for the study of fuzzy sets, and have since proved to be an appropriate framework for the development of complement-free mathematical concepts. In this paper the authors lay the foundation for a theory of uniformities in a textural context. Analogues are given for both the diagonal and covering approaches to the classical theory of uniform structures, the notion of uniform topology is generalized and an analogue given for the well known result that a topological space is uniformizable if and only if it is completely regular. Finally a textural analogue of the classical interplay between uniformities and families of pseudo-metrics is presented.

  11. BREAD CRUMBS TEXTURE OF SPELT

    Directory of Open Access Journals (Sweden)

    Joanna Korczyk – Szabó

    2014-02-01

    Full Text Available Texture analysis is an objective physical examination of baked products and gives direct information on the product quality, oppositely to dough rheology tests what inform on the baking suitability of the flour, as raw material. Evaluation of the mechanical properties of bread crumb is important not only for quality assurance in the bakeries, but also for assessing the effects of changes in dough ingredients and processing condition and also for describing the changes in bread crumb during storage. Crumb cellular structure is an important quality criterion used in commercial baking and research laboratories to judge bread quality alongside taste, crumb colour and crumb physical texture. In the framework of our research during the years 2010 – 2011 were analyzed selected indicators of bread crumb for texture quality of three Triticum spelta L. cultivars – Altgold, Rubiota and Ostro grown in an ecological system. The bread texture quality was evaluated on texture analyzer TA.XT Plus (Stable Micro Systems, Surrey, UK, following the AACC (74-09 standard and expressed as crumb firmness (N, stiffness (N.mm-1 and relative elasticity (%. Our research proved that all selected indicators were significantly influenced by the year of growing and variety. The most soft bread was achieved in Rubiota, whereas bread crumb samples from Altgold and Ostro were the most firm and stiff. Correlation analysis showed strong negative correlation between relative elasticity and bread crumb firmness as well as bread stiffness (-0.65++, -0.66++. The spelt wheat bread crumb texture need further investigation as it can be a reliable quality parameter.

  12. Bridges between multiple-point geostatistics and texture synthesis: Review and guidelines for future research

    Science.gov (United States)

    Mariethoz, Gregoire; Lefebvre, Sylvain

    2014-05-01

    Multiple-Point Simulations (MPS) is a family of geostatistical tools that has received a lot of attention in recent years for the characterization of spatial phenomena in geosciences. It relies on the definition of training images to represent a given type of spatial variability, or texture. We show that the algorithmic tools used are similar in many ways to techniques developed in computer graphics, where there is a need to generate large amounts of realistic textures for applications such as video games and animated movies. Similarly to MPS, these texture synthesis methods use training images, or exemplars, to generate realistic-looking graphical textures. Both domains of multiple-point geostatistics and example-based texture synthesis present similarities in their historic development and share similar concepts. These disciplines have however remained separated, and as a result significant algorithmic innovations in each discipline have not been universally adopted. Texture synthesis algorithms present drastically increased computational efficiency, patterns reproduction and user control. At the same time, MPS developed ways to condition models to spatial data and to produce 3D stochastic realizations, which have not been thoroughly investigated in the field of texture synthesis. In this paper we review the possible links between these disciplines and show the potential and limitations of using concepts and approaches from texture synthesis in MPS. We also provide guidelines on how recent developments could benefit both fields of research, and what challenges remain open.

  13. Laser surface texturing of tool steel: textured surfaces quality evaluation

    Science.gov (United States)

    Šugár, Peter; Šugárová, Jana; Frnčík, Martin

    2016-05-01

    In this experimental investigation the laser surface texturing of tool steel of type 90MnCrV8 has been conducted. The 5-axis highly dynamic laser precision machining centre Lasertec 80 Shape equipped with the nano-second pulsed ytterbium fibre laser and CNC system Siemens 840 D was used. The planar and spherical surfaces first prepared by turning have been textured. The regular array of spherical and ellipsoidal dimples with a different dimensions and different surface density has been created. Laser surface texturing has been realized under different combinations of process parameters: pulse frequency, pulse energy and laser beam scanning speed. The morphological characterization of ablated surfaces has been performed using scanning electron microscopy (SEM) technique. The results show limited possibility of ns pulse fibre laser application to generate different surface structures for tribological modification of metallic materials. These structures were obtained by varying the processing conditions between surface ablation, to surface remelting. In all cases the areas of molten material and re-cast layers were observed on the bottom and walls of the dimples. Beside the influence of laser beam parameters on the machined surface quality during laser machining of regular hemispherical and elipsoidal dimple texture on parabolic and hemispherical surfaces has been studied.

  14. Physics and application of persistent spin helix state in semiconductor heterostructures

    Science.gov (United States)

    Kohda, Makoto; Salis, Gian

    2017-07-01

    In order to utilize the spin degree of freedom in semiconductors, control of spin states and transfer of the spin information are fundamental requirements for future spintronic devices and quantum computing. Spin orbit (SO) interaction generates an effective magnetic field for moving electrons and enables spin generation, spin manipulation and spin detection without using external magnetic field and magnetic materials. However, spin relaxation also takes place due to a momentum dependent SO-induced effective magnetic field. As a result, SO interaction is considered to be a double-edged sword facilitating spin control but preventing spin transport over long distances. The persistent spin helix (PSH) state solves this problem since uniaxial alignment of the SO field with SU(2) symmetry enables the suppression of spin relaxation while spin precession can still be controlled. Consequently, understanding the PSH becomes an important step towards future spintronic technologies for classical and quantum applications. Here, we review recent progress of PSH in semiconductor heterostructures and its device application. Fundamental physics of SO interaction and the conditions of a PSH state in semiconductor heterostructures are discussed. We introduce experimental techniques to observe a PSH and explain both optical and electrical measurements for detecting a long spin relaxation time and the formation of a helical spin texture. After emphasizing the bulk Dresselhaus SO coefficient γ, the application of PSH states for spin transistors and logic circuits are discussed.

  15. Height and Tilt Geometric Texture

    DEFF Research Database (Denmark)

    Andersen, Vedrana; Desbrun, Mathieu; Bærentzen, Jakob Andreas

    2009-01-01

    compromise between functionality and simplicity: it can efficiently handle and process geometric texture too complex to be represented as a height field, without having recourse to full blown mesh editing algorithms. The height-and-tilt representation proposed here is fully intrinsic to the mesh, making...

  16. Texture analysis using Gabor wavelets

    Science.gov (United States)

    Naghdy, Golshah A.; Wang, Jian; Ogunbona, Philip O.

    1996-04-01

    Receptive field profiles of simple cells in the visual cortex have been shown to resemble even- symmetric or odd-symmetric Gabor filters. Computational models employed in the analysis of textures have been motivated by two-dimensional Gabor functions arranged in a multi-channel architecture. More recently wavelets have emerged as a powerful tool for non-stationary signal analysis capable of encoding scale-space information efficiently. A multi-resolution implementation in the form of a dyadic decomposition of the signal of interest has been popularized by many researchers. In this paper, Gabor wavelet configured in a 'rosette' fashion is used as a multi-channel filter-bank feature extractor for texture classification. The 'rosette' spans 360 degrees of orientation and covers frequencies from dc. In the proposed algorithm, the texture images are decomposed by the Gabor wavelet configuration and the feature vectors corresponding to the mean of the outputs of the multi-channel filters extracted. A minimum distance classifier is used in the classification procedure. As a comparison the Gabor filter has been used to classify the same texture images from the Brodatz album and the results indicate the superior discriminatory characteristics of the Gabor wavelet. With the test images used it can be concluded that the Gabor wavelet model is a better approximation of the cortical cell receptive field profiles.

  17. Sensory memory and food texture

    NARCIS (Netherlands)

    Mojet, J.; Köster, E.P.

    2005-01-01

    Memory for texture plays an important role in food expectations. After fasting overnight, subjects (41 women, 35 men, age 19-60 years) received a breakfast including breakfast drink, biscuits and yoghurt. Subsequently, they rated their hunger feelings every hour, and returned for a taste experiment

  18. Colloidal aspects of texture perception

    NARCIS (Netherlands)

    Vliet, van T.

    2010-01-01

    The perception of complex textures in food is strongly related to the way food is processed during eating, and is modulated by other basic characteristics, such as taste and aroma. An understanding at the colloidal level of the basic processes in the mouth is essential in order to link the

  19. Sensory memory and food texture

    NARCIS (Netherlands)

    Mojet, J.; Koster, E.P.

    2005-01-01

    Memory for texture plays an important role in food expectations. After fasting overnight, subjects (41 women, 35 men, age 19¿60 years) received a breakfast including breakfast drink, biscuits and yoghurt. Subsequently, they rated their hunger feelings every hour, and returned for a taste experiment

  20. Euromet Comparison on Surface Texture

    DEFF Research Database (Denmark)

    Koenders, L.; Andreasen, Jan Lasson; De Chiffre, Leonardo

    2004-01-01

    In the region of EUROMET, we performed from 2001 to 2003 a comparison covering a number among the most interesting parameters in the field of surface texture, i.e. Pt, D, Ra, Rz, RSm, and the Rk-parameters. 16 institutes carried out measurements on typical roughness standards as described in ISO...

  1. Texture of lipid bilayer domains

    DEFF Research Database (Denmark)

    Jensen, Uffe Bernchou; Brewer, Jonathan R.; Midtiby, Henrik Skov

    2009-01-01

    We investigate the texture of gel (g) domains in binary lipid membranes composed of the phospholipids DPPC and DOPC. Lateral organization of lipid bilayer membranes is a topic of fundamental and biological importance. Whereas questions related to size and composition of fluid membrane domain...

  2. Colloidal aspects of texture perception

    NARCIS (Netherlands)

    Vliet, T. van; Aken, G.A. van; Jongh, H.H.J. de; Hamer, R.J.

    2009-01-01

    Recently, considerable attention has been given to the understanding of texture attributes that cannot directly be related to physical properties of food, such as creamy, crumbly and watery. The perception of these attributes is strongly related to the way the food is processed during food intake,

  3. Spin-orbit torques in magnetic bilayers

    Science.gov (United States)

    Haney, Paul

    2015-03-01

    Spintronics aims to utilize the coupling between charge transport and magnetic dynamics to develop improved and novel memory and logic devices. Future progress in spintronics may be enabled by exploiting the spin-orbit coupling present at the interface between thin film ferromagnets and heavy metals. In these systems, applying an in-plane electrical current can induce magnetic dynamics in single domain ferromagnets, or can induce rapid motion of domain wall magnetic textures. There are multiple effects responsible for these dynamics. They include spin-orbit torques and a chiral exchange interaction (the Dzyaloshinskii-Moriya interaction) in the ferromagnet. Both effects arise from the combination of ferromagnetism and spin-orbit coupling present at the interface. There is additionally a torque from the spin current flux impinging on the ferromagnet, arising from the spin hall effect in the heavy metal. Using a combination of approaches, from drift-diffusion to Boltzmann transport to first principles methods, we explore the relative contributions to the dynamics from these different effects. We additionally propose that the transverse spin current is locally enhanced over its bulk value in the vicinity of an interface which is oriented normal to the charge current direction.

  4. Sensory and instrumental texture analysis of Bulgarian commercial pates

    Directory of Open Access Journals (Sweden)

    M. Tonchev

    2017-09-01

    Full Text Available Abstract. The aim of this study was to characterize the textural differences between Bulgarian commercial pates with different ingredients and to adapt the used methods for later application in texture analysis of sterilized meat products. Texture parameters were studied by sensory and instrumental methods. The sensory panel was stated from students in similar age and was asked to fulfill a questionnaire about their likening the poultry pates bought from the commercial network. Nine points sensory scales were used, about appearance, colour, spreadability by knife to bread, flavor, consistency, taste, aftertaste and overall likening. The panelists were asked to rank the pates based on their colour, spreadability and consistency. Instrumental texture parameters – texture profile and spreadability work, were analyzed by Stable Micro Systems texture analyzer in Texture Profile Analysis (TPA and compression methods. For further analysis of spreadability, the probes were scanned by flatbed scanner before and after compression and their area ratio was measured by image analysis method. The results of sensory analysis show that, the pate with duck meat received the highest liking based on the overall liking, followed by pate with turkey meat and pate from chicken meat and liver and the lowest liked was the pate with goose meat. Based on the sensory spreadability and consistency the hardest was the pate with goose meat followed by pate with turkey meat and pate from chicken meat and liver and the softest was the pate with duck meat. The results from instrumental spreadability and hardness showed positive correlations with the results of the sensory analysis.

  5. Feature-aware natural texture synthesis

    KAUST Repository

    Wu, Fuzhang

    2014-12-04

    This article presents a framework for natural texture synthesis and processing. This framework is motivated by the observation that given examples captured in natural scene, texture synthesis addresses a critical problem, namely, that synthesis quality can be affected adversely if the texture elements in an example display spatially varied patterns, such as perspective distortion, the composition of different sub-textures, and variations in global color pattern as a result of complex illumination. This issue is common in natural textures and is a fundamental challenge for previously developed methods. Thus, we address it from a feature point of view and propose a feature-aware approach to synthesize natural textures. The synthesis process is guided by a feature map that represents the visual characteristics of the input texture. Moreover, we present a novel adaptive initialization algorithm that can effectively avoid the repeat and verbatim copying artifacts. Our approach improves texture synthesis in many images that cannot be handled effectively with traditional technologies.

  6. Heat and spin interconversion

    International Nuclear Information System (INIS)

    Ohnuma, Yuichi; Matsuo, Mamoru; Maekawa, Sadamichi; Saitoh, Eeiji

    2017-01-01

    Spin Seebeck and spin Peltier effects, which are mutual conversion phenomena of heat and spin, are discussed on the basis of the microscopic theory. First, the spin Seebeck effect, which is the spin-current generation due to heat current, is discussed. The recent progress in research on the spin Seebeck effect are introduced. We explain the origin of the observed sign changes of the spin Seebeck effect in compensated ferromagnets. Next, the spin Peltier effect, which is the heat-current generation due to spin current, is discussed. Finally, we show that the spin Seebeck and spin Peltier effects are summarized by Onsager's reciprocal relation and derive Kelvin's relation for the spin and heat transports. (author)

  7. A multi-resolution texture fusion algorithm

    Science.gov (United States)

    Li, Yu Qin; Zhou, Xiang; Guo, Jia Yu; Yang, Tao; Fei, Zi Xuan

    2017-09-01

    Texture fusion is essential for three-dimensional photo-realistic texture model reconstruction. Multi-resolution texture fusion mainly is applied to reconstruct three-dimensional models that the local texture is very realistic. This paper presents a multi-resolution texture fusion algorithm based on digital image processing. The technique utilizes the depth camera to obtain range data and the texture camera to obtain the local interested high-resolution texture of the object. And each point of the range images a pixel of the picture corresponding to this view should be found, so the map between high-resolution texture and local three-dimensional points could be obtained by calibrating texture camera and depth camera to register the local high-resolution texture with the low resolution texture collected by the depth camera or calibrating texture camera and depth camera. ICP is applied to register models, and mapping different-resolution textures onto three-dimensional models. Then the light source correction of textures is applied to remove the systematic differences such as lighting change which are achieved by computing linear regression correction mode. Finally, the global correction is applied to refine the observable variations in color that may still exist near the fusion boundaries. These corrections will utilize the grid triangle vertex color as a constraint to drive texture fusion to remove discontinuities from different resolutions. The advantage of this technique is that it utilizes the light source correction and global correction to fuse different resolutions textures. Experiments with this technique indicate that it significantly corrects the observable discontinuities within the overlapping areas, which are given from different resolutions, lighting change, non-lambertian object surface, etc.

  8. Control and characterization of textured, hydrophobic ionomer surfaces

    Science.gov (United States)

    Wang, Xueyuan

    Polymer thin films are of increasing interest in many industrial and technological applications. Superhydrophobic, self-cleaning surfaces have attracted a lot of attention for their application in self-cleaning, anti-sticking coatings, stain resistance, or anti-contamination surfaces in diverse technologies, including medical, transportation, textiles, electronics and paints. This thesis focuses on the preparation of nanometer to micrometer-size particle textured surfaces which are desirable for super water repellency. Textured surfaces consisting of nanometer to micrometer-sized lightly sulfonated polystyrene ionomer (SPS) particles were prepared by rapid evaporation of the solvent from a dilute polymer solution cast onto silica. The effect of the solvent used to spin coat the film, the molecular weight of the ionomer, and the rate of solvent evaporation were investigated. The nano-particle or micron-particle textured ionomer surfaces were prepared by either spin coating or solution casting ionomer solutions at controlled evaporation rates. The surface morphologies were consistent with a spinodal decomposition mechanism where the surface first existed as a percolated-like structure and then ripened into droplets if molecular mobility was retained for sufficient time. The SPS particles or particle aggregates were robust and resisted deformation even after annealing at 120°C for one week. The water contact angles on as-prepared surfaces were relatively low, ~ 90° since the polar groups in ionomer reduce the surface hydrophobicity. After chemical vapor deposition of 1H,1H,2H,2H-perfluorooctyltrichlorosilane, the surface contact angles increased to ~ 109° on smooth surfaces and ~140° on the textured surfaces. Water droplets stuck to these surfaces even when tilted 90 degrees. Superhydrophobic surfaces were prepared by spraying coating ionomer solutions and Chemical Vapor Deposition (CVD) of 1H,1H,2H,2H-perfluorooctyltrichlorosilane onto textured surfaces. The

  9. Texture analysis using Renyi's generalized entropies

    NARCIS (Netherlands)

    Grigorescu, SE; Petkov, N

    2003-01-01

    We propose a texture analysis method based on Renyi's generalized entropies. The method aims at identifying texels in regular textures by searching for the smallest window through which the minimum number of different visual patterns is observed when moving the window over a given texture. The

  10. Real-time Texture Error Detection

    Directory of Open Access Journals (Sweden)

    Dan Laurentiu Lacrama

    2008-01-01

    Full Text Available This paper advocates an improved solution for the real-time error detection of texture errors that occurs in the production process in textile industry. The research is focused on the mono-color products with 3D texture model (Jacquard fabrics. This is a more difficult task than, for example, 2D multicolor textures.

  11. Evaluation of color representation for texture analysis

    NARCIS (Netherlands)

    Verbrugge, R.; van den Broek, Egon; van Rikxoort, E.M.; Taatgen, N.; Schomaker, L.

    2004-01-01

    Since more than 50 years texture in image material is a topic of research. Hereby, color was ignored mostly. This study compares 70 different configurations for texture analysis, using four features. For the configurations we used: (i) a gray value texture descriptor: the co-occurrence matrix and a

  12. Texture Control: Theoretical and Practical Study

    DEFF Research Database (Denmark)

    Leffers, Torben; Gangli, P.

    1978-01-01

    The possibility of controlling the rolling texture by simple modifications to the rolling process is investigated. It is demonstrated that the computer programs developed for simulation of the normal rolling textures can also satisfactorily predict textures formed under new rolling conditions...

  13. Optimal Charge-to-Spin Conversion in Graphene on Transition-Metal Dichalcogenides

    Science.gov (United States)

    Offidani, Manuel; Milletarı, Mirco; Raimondi, Roberto; Ferreira, Aires

    2017-11-01

    When graphene is placed on a monolayer of semiconducting transition metal dichalcogenide (TMD) its band structure develops rich spin textures due to proximity spin-orbital effects with interfacial breaking of inversion symmetry. In this work, we show that the characteristic spin winding of low-energy states in graphene on a TMD monolayer enables current-driven spin polarization, a phenomenon known as the inverse spin galvanic effect (ISGE). By introducing a proper figure of merit, we quantify the efficiency of charge-to-spin conversion and show it is close to unity when the Fermi level approaches the spin minority band. Remarkably, at high electronic density, even though subbands with opposite spin helicities are occupied, the efficiency decays only algebraically. The giant ISGE predicted for graphene on TMD monolayers is robust against disorder and remains large at room temperature.

  14. Spin transport studies in encapsulated CVD graphene

    Science.gov (United States)

    Avsar, Ahmet; You Tan, Jun; Ho, Yuda; Koon, Gavin; Oezyilmaz, Barbaros

    2013-03-01

    Spin transport studies in exfoliated graphene on SiO2/Si substrates have shown spin relaxation times that are orders of magnitude shorter than the theoretical predictions. Similar to the charge transport case, the underlying substrate is expected to be the limiting factor. The recent work Zomer, P. J. et al. shows that spin transport over lengths up to 20um is possible in high mobility exfoliated graphene devices on boron nitride (BN) substrates. Here we discuss our initial attempts to repeat such spin transport experiments with CVD graphene on BN substrates. The effect of encapsulation of such devices with an extra BN layer will be also discussed.

  15. Positivity of spin foam amplitudes

    International Nuclear Information System (INIS)

    Baez, John C; Christensen, J Daniel

    2002-01-01

    The amplitude for a spin foam in the Barrett-Crane model of Riemannian quantum gravity is given as a product over its vertices, edges and faces, with one factor of the Riemannian 10j symbols appearing for each vertex, and simpler factors for the edges and faces. We prove that these amplitudes are always nonnegative for closed spin foams. As a corollary, all open spin foams going between a fixed pair of spin networks have real amplitudes of the same sign. This means one can use the Metropolis algorithm to compute expectation values of observables in the Riemannian Barrett-Crane model, as in statistical mechanics, even though this theory is based on a real-time (e iS ) rather than imaginary-time e -S path integral. Our proof uses the fact that when the Riemannian 10j symbols are nonzero, their sign is positive or negative depending on whether the sum of the ten spins is an integer or half-integer. For the product of 10j symbols appearing in the amplitude for a closed spin foam, these signs cancel. We conclude with some numerical evidence suggesting that the Lorentzian 10j symbols are always nonnegative, which would imply similar results for the Lorentzian Barrett-Crane model

  16. Spinning out a star.

    Science.gov (United States)

    Lord, Michael D; Mandel, Stanley W; Wager, Jeffrey D

    2002-06-01

    Spinouts rarely take off; most, in fact, fall into one or more of four traps that doom them from the start. Some companies spin out ventures that are too close to the core of their businesses, in effect selling off their crown jewels. Sometimes, a parent company uses the spinout primarily to pawn off debt or expenses or to quickly raise external capital for itself. Other times, a company may try to spin out an area of its business that lacks one or more of the critical legs of a successful company--a coherent business model, say, or a solid financial base. And in many cases, parent companies can't bring themselves to sever their ownership ties and give up control of their spinouts. R.J. Reynolds, the tobacco giant, managed to avoid these traps when it successfully spun out a most unlikely venture, the pharmaceutical company Targacept. As the story illustrates, the problem with spinouts is similar to the problem of rich children. Their parents have the wherewithal to spoil them or shelter them or cling to them, but what they need is tough love and discipline--much the same discipline that characterizes successful start-ups. R.J. Reynolds recognized that it didn't know that much about the pharmaceutical business and couldn't merely try to spin out a small clone of itself. It had to treat the venture as if it were essentially starting from scratch, with a passionate entrepreneurial leader, a solid business plan, help from outside partners in the industry, and ultimately substantial venture backing. That these lessons are less obvious to executives contemplating spinning out ventures closer to their core businesses may be why so many spinouts fail.

  17. Nuclear spin pumping and electron spin susceptibilities

    NARCIS (Netherlands)

    Danon, J.; Nazarov, Y.V.

    2011-01-01

    In this work we present a new formalism to evaluate the nuclear spin dynamics driven by hyperfine interaction with nonequilibrium electron spins. To describe the dynamics up to second order in the hyperfine coupling it suffices to evaluate the susceptibility and fluctuations of the electron spin.

  18. MRI texture heterogeneity in the optic nerve predicts visual recovery after acute optic neuritis

    Directory of Open Access Journals (Sweden)

    Yunyan Zhang

    2014-01-01

    Conclusions: Tissue heterogeneity may be a potential measure of functional outcome in ON patients and advanced analysis of the texture in standard MRI could provide insights into mechanisms of injury and recovery in patients with similar disorders.

  19. Interface-induced chiral domain walls, spin spirals and skyrmions revealed by spin-polarized scanning tunneling microscopy.

    Science.gov (United States)

    von Bergmann, Kirsten; Kubetzka, André; Pietzsch, Oswald; Wiesendanger, Roland

    2014-10-01

    The spin textures of ultra-thin magnetic layers exhibit surprising variety. The loss of inversion symmetry at the interface of the magnetic layer and substrate gives rise to the so-called Dzyaloshinskii-Moriya interaction which favors non-collinear spin arrangements with unique rotational sense. Here we review the application of spin-polarized scanning tunneling microscopy to such systems, which has led to the discovery of interface-induced chiral domain walls and spin spirals. Recently, different interface-driven skyrmion lattices have been found, and the writing as well as the deleting of individual skyrmions based on local spin-polarized current injection has been demonstrated. These interface-induced non-collinear magnetic states offer new exciting possibilities to study fundamental magnetic interactions and to tailor material properties for spintronic applications.

  20. High frequency spin torque oscillators with composite free layer spin valve

    International Nuclear Information System (INIS)

    Natarajan, Kanimozhi; Arumugam, Brinda; Rajamani, Amuda

    2016-01-01

    We report the oscillations of magnetic spin components in a composite free layer spin valve. The associated Landau–Lifshitz–Gilbert–Slonczewski (LLGS) equation is studied by stereographically projecting the spin on to a complex plane and the spin components were found. A fourth order Runge–Kutta numerical integration on LLGS equation also confirms the similar trajectories of the spin components. This study establishes the possibility of a Spin Torque Oscillator in a composite free layer spin valve, where the exchange coupling is ferromagnetic in nature. In-plane and out-of-plane precessional modes of magnetization oscillations were found in zero applied magnetic field and the frequencies of the oscillations were calculated from Fast Fourier Transform of the components of magnetization. Behavior of Power Spectral Density for a range of current density is studied. Finally our analysis shows the occurrence of highest frequency 150 GHz, which is in the second harmonics for the specific choice of system parameters.

  1. Watermarking textures in video games

    Science.gov (United States)

    Liu, Huajian; Berchtold, Waldemar; Schäfer, Marcel; Lieb, Patrick; Steinebach, Martin

    2014-02-01

    Digital watermarking is a promising solution to video game piracy. In this paper, based on the analysis of special challenges and requirements in terms of watermarking textures in video games, a novel watermarking scheme for DDS textures in video games is proposed. To meet the performance requirements in video game applications, the proposed algorithm embeds the watermark message directly in the compressed stream in DDS files and can be straightforwardly applied in watermark container technique for real-time embedding. Furthermore, the embedding approach achieves high watermark payload to handle collusion secure fingerprinting codes with extreme length. Hence, the scheme is resistant to collusion attacks, which is indispensable in video game applications. The proposed scheme is evaluated in aspects of transparency, robustness, security and performance. Especially, in addition to classical objective evaluation, the visual quality and playing experience of watermarked games is assessed subjectively in game playing.

  2. Visual perception of procedural textures: identifying perceptual dimensions and predicting generation models.

    Directory of Open Access Journals (Sweden)

    Jun Liu

    Full Text Available Procedural models are widely used in computer graphics for generating realistic, natural-looking textures. However, these mathematical models are not perceptually meaningful, whereas the users, such as artists and designers, would prefer to make descriptions using intuitive and perceptual characteristics like "repetitive," "directional," "structured," and so on. To make up for this gap, we investigated the perceptual dimensions of textures generated by a collection of procedural models. Two psychophysical experiments were conducted: free-grouping and rating. We applied Hierarchical Cluster Analysis (HCA and Singular Value Decomposition (SVD to discover the perceptual features used by the observers in grouping similar textures. The results suggested that existing dimensions in literature cannot accommodate random textures. We therefore utilized isometric feature mapping (Isomap to establish a three-dimensional perceptual texture space which better explains the features used by humans in texture similarity judgment. Finally, we proposed computational models to map perceptual features to the perceptual texture space, which can suggest a procedural model to produce textures according to user-defined perceptual scales.

  3. Magnetic Nanostructures Spin Dynamics and Spin Transport

    CERN Document Server

    Farle, Michael

    2013-01-01

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

  4. Spin-orbit interaction in multiple quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Ya-Fei, E-mail: haoyafei@zjnu.cn [Physics Department, Zhejiang Normal University, Zhejiang 321004 (China)

    2015-01-07

    In this paper, we investigate how the structure of multiple quantum wells affects spin-orbit interactions. To increase the interface-related Rashba spin splitting and the strength of the interface-related Rashba spin-orbit interaction, we designed three kinds of multiple quantum wells. We demonstrate that the structure of the multiple quantum wells strongly affected the interface-related Rashba spin-orbit interaction, increasing the interface-related Rashba spin splitting to up to 26% larger in multiple quantum wells than in a stepped quantum well. We also show that the cubic Dresselhaus spin-orbit interaction similarly influenced the spin relaxation time of multiple quantum wells and that of a stepped quantum well. The increase in the interface-related Rashba spin splitting originates from the relationship between interface-related Rashba spin splitting and electron probability density. Our results suggest that multiple quantum wells can be good candidates for spintronic devices.

  5. Spin-orbit interaction in multiple quantum wells

    International Nuclear Information System (INIS)

    Hao, Ya-Fei

    2015-01-01

    In this paper, we investigate how the structure of multiple quantum wells affects spin-orbit interactions. To increase the interface-related Rashba spin splitting and the strength of the interface-related Rashba spin-orbit interaction, we designed three kinds of multiple quantum wells. We demonstrate that the structure of the multiple quantum wells strongly affected the interface-related Rashba spin-orbit interaction, increasing the interface-related Rashba spin splitting to up to 26% larger in multiple quantum wells than in a stepped quantum well. We also show that the cubic Dresselhaus spin-orbit interaction similarly influenced the spin relaxation time of multiple quantum wells and that of a stepped quantum well. The increase in the interface-related Rashba spin splitting originates from the relationship between interface-related Rashba spin splitting and electron probability density. Our results suggest that multiple quantum wells can be good candidates for spintronic devices

  6. Texture Classification for 3D Urban Map

    Directory of Open Access Journals (Sweden)

    Inatsuka Hiroyuki

    2009-01-01

    Full Text Available This paper proposes a method to control texture resolution for rendering large-scale 3D urban maps. Since on the 3D maps texture data generally tend to be far larger than geometry information such as vertices and triangles, it is more effective to reduce the texture by exploiting the LOD (Level of Detail in order to decrease whole data size. For this purpose, we propose a new method to control the resolution of the texture. In our method we classify the textures to four classes based on their salient features. The appropriate texture resolutions are decided based on the classification resulsts, their rendered sizes on a display, and their level of importance. We verify the validity of our texture classification algorithm by applying it to the large-scale 3D urban map rendering.

  7. Crystallographic Textures and Morphologies of Solution Cast Ibuprofen Composite Films at Solid Surfaces

    Science.gov (United States)

    2014-01-01

    The preparation of thin composite layers has promising advantages in a variety of applications like transdermal, buccal, or sublingual patches. Within this model study the impact of the matrix material on the film forming properties of ibuprofen–matrix composite films is investigated. As matrix materials polystyrene, methyl cellulose, or hydroxyl-ethyl cellulose were used. The film properties were either varied by the preparation route, i.e., spin coating or drop casting, or via changes in the relative ratio of the ibuprofen and the matrix material. The resulting films were investigated via X-ray diffraction and atomic force microscope experiments. The results show that preferred (100) textures can be induced via spin coating with respect to the glass surface, while the drop casting results in a powder-like behavior. The morphologies of the films are strongly impacted by the ibuprofen amount rather than the preparation method. A comparison of the various matrix materials in terms of their impact on the dissolution properties show a two times faster zero order release from methyl cellulose matrix compared to a polystyrene matrix. The slowest rate was observed within the hydroxyl ethyl cellulose as the active pharmaceutical ingredients (APIs) release is limited by diffusion through a swollen matrix. The investigation reveals that the ibuprofen crystallization and film formation is only little effected by the selected matrix material than that compared to the dissolution. A similar experimental approach using other matrix materials may therefore allow to find an optimized composite layer useful for a defined application. PMID:25275801

  8. Birefringence (spin rotation and spin dichroism) of high-energy deuterons

    International Nuclear Information System (INIS)

    Baryshevskij, V.G.; Rovba, A.A.

    2016-01-01

    The phenomenon of birefringence (spin rotation and spin dichroism) of high-energy deuterons, currently observed in experiments, is the macroscopic quantum effect similar to the birefringence effect known in optics. This paper considers the contribution coming to the spin dichroism effect from the interaction of deuteron electric quadrupole moment and nuclear electric field. The effect proves to be responsive to the behavior of deuteron ground state wave functions at a small distance. [ru

  9. The neural substrate for working memory of tactile surface texture.

    Science.gov (United States)

    Kaas, Amanda L; van Mier, Hanneke; Visser, Maya; Goebel, Rainer

    2013-05-01

    Fine surface texture is best discriminated by touch, in contrast to macro geometric features like shape. We used functional magnetic resonance imaging and a delayed match-to-sample task to investigate the neural substrate for working memory of tactile surface texture. Blindfolded right-handed males encoded the texture or location of up to four sandpaper stimuli using the dominant or non-dominant hand. They maintained the information for 10-12 s and then answered whether a probe stimulus matched the memory array. Analyses of variance with the factors Hand, Task, and Load were performed on the estimated percent signal change for the encoding and delay phase. During encoding, contralateral effects of Hand were found in sensorimotor regions, whereas Load effects were observed in bilateral postcentral sulcus (BA2), secondary somatosensory cortex (S2), pre-SMA, dorsolateral prefrontal cortex (dlPFC), and superior parietal lobule (SPL). During encoding and delay, Task effects (texture > location) were found in central sulcus, S2, pre-SMA, dlPFC, and SPL. The Task and Load effects found in hand- and modality-specific regions BA2 and S2 indicate involvement of these regions in the tactile encoding and maintenance of fine surface textures. Similar effects in hand- and modality-unspecific areas dlPFC, pre-SMA and SPL suggest that these regions contribute to the cognitive monitoring required to encode and maintain multiple items. Our findings stress both the particular importance of S2 for the encoding and maintenance of tactile surface texture, as well as the supramodal nature of parieto-frontal networks involved in cognitive control. Copyright © 2012 Wiley Periodicals, Inc.

  10. Possible evidence for spin-transfer torque induced by spin-triplet supercurrent

    KAUST Repository

    Li, Lailai

    2017-10-04

    Cooper pairs in superconductors are normally spin singlet. Nevertheless, recent studies suggest that spin-triplet Cooper pairs can be created at carefully engineered superconductor-ferromagnet interfaces. If Cooper pairs are spin-polarized they would transport not only charge but also a net spin component, but without dissipation, and therefore minimize the heating effects associated with spintronic devices. Although it is now established that triplet supercurrents exist, their most interesting property - spin - is only inferred indirectly from transport measurements. In conventional spintronics, it is well known that spin currents generate spin-transfer torques that alter magnetization dynamics and switch magnetic moments. The observation of similar effects due to spin-triplet supercurrents would not only confirm the net spin of triplet pairs but also pave the way for applications of superconducting spintronics. Here, we present a possible evidence for spin-transfer torques induced by triplet supercurrents in superconductor/ferromagnet/superconductor (S/F/S) Josephson junctions. Below the superconducting transition temperature T_c, the ferromagnetic resonance (FMR) field at X-band (~ 9.0 GHz) shifts rapidly to a lower field with decreasing temperature due to the spin-transfer torques induced by triplet supercurrents. In contrast, this phenomenon is absent in ferromagnet/superconductor (F/S) bilayers and superconductor/insulator/ferromagnet/superconductor (S/I/F/S) multilayers where no supercurrents pass through the ferromagnetic layer. These experimental observations are discussed with theoretical predictions for ferromagnetic Josephson junctions with precessing magnetization.

  11. Quasi spin pairing and the structure of the Lipkin model

    International Nuclear Information System (INIS)

    Cambiaggio, M.C.; Plastino, A.

    1978-01-01

    By introducing the concepts of quasi-spin pairing and quasi-spin seniority, the Lipkin model is extended to a variable number of particles. The properties of quasi-spin pairing are seen to be quite similar to those of ordinary pairing. The quasi-spin seniority allows one to obtain a simple classification of excited multiplets. A 'pairing plus monopole' model is studied in connection with the Hartree-Fock theory. (orig.) [de

  12. Decoherence dynamics of a single spin versus spin ensemble

    NARCIS (Netherlands)

    Dobrovitski, V.V.; Feiguin, A.E.; Awschalom, D.D.; Hanson, R.

    2008-01-01

    We study decoherence of central spins by a spin bath, focusing on the difference between measurement of a single central spin and measurement of a large number of central spins (as found in typical spin-resonance experiments). For a dilute spin bath, the single spin demonstrates Gaussian

  13. Aesthetic Perception of Visual Textures: A Holistic Exploration using Texture Analysis, Psychological Experiment and Perception Modeling

    Directory of Open Access Journals (Sweden)

    Jianli eLiu

    2015-11-01

    Full Text Available Modeling human aesthetic perception of visual textures is important and valuable in numerous industrial domains, such as product design, architectural design and decoration. Based on results from a semantic differential rating experiment, we modeled the relationship between low-level basic texture features and aesthetic properties involved in human aesthetic texture perception. First, we compute basic texture features from textural images using four classical methods. These features are neutral, objective and independent of the socio-cultural context of the visual textures. Then, we conduct a semantic differential rating experiment to collect from evaluators their aesthetic perceptions of selected textural stimuli. In semantic differential rating experiment, eights pairs of aesthetic properties are chosen, which are strongly related to the socio-cultural context of the selected textures and to human emotions. They are easily understood and connected to everyday life. We propose a hierarchical feed-forward layer model of aesthetic texture perception and assign 8 pairs of aesthetic properties to different layers. Finally, we describe the generation of multiple linear and nonlinear regression models for aesthetic prediction by taking dimensionality-reduced texture features and aesthetic properties of visual textures as dependent and independent variables, respectively. Our experimental results indicate that the relationships between each layer and its neighbors in the hierarchical feed-forward layer model of aesthetic texture perception can be fitted well by linear functions, and the models thus generated can successfully bridge the gap between computational texture features and aesthetic texture properties.

  14. Spin-polarized spin excitation spectroscopy

    International Nuclear Information System (INIS)

    Loth, Sebastian; Lutz, Christopher P; Heinrich, Andreas J

    2010-01-01

    We report on the spin dependence of elastic and inelastic electron tunneling through transition metal atoms. Mn, Fe and Cu atoms were deposited onto a monolayer of Cu 2 N on Cu(100) and individually addressed with the probe tip of a scanning tunneling microscope. Electrons tunneling between the tip and the substrate exchange energy and spin angular momentum with the surface-bound magnetic atoms. The conservation of energy during the tunneling process results in a distinct onset threshold voltage above which the tunneling electrons create spin excitations in the Mn and Fe atoms. Here we show that the additional conservation of spin angular momentum leads to different cross-sections for spin excitations depending on the relative alignment of the surface spin and the spin of the tunneling electron. For this purpose, we developed a technique for measuring the same local spin with a spin-polarized and a non-spin-polarized tip by exchanging the last apex atom of the probe tip between different transition metal atoms. We derive a quantitative model describing the observed excitation cross-sections on the basis of an exchange scattering process.

  15. Magnons, Spin Current and Spin Seebeck Effect

    Science.gov (United States)

    Maekawa, Sadamichi

    2012-02-01

    When metals and semiconductors are placed in a temperature gradient, the electric voltage is generated. This mechanism to convert heat into electricity, the so-called Seebeck effect, has attracted much attention recently as the mechanism for utilizing wasted heat energy. [1]. Ferromagnetic insulators are good conductors of spin current, i.e., the flow of electron spins [2]. When they are placed in a temperature gradient, generated are magnons, spin current and the spin voltage [3], i.e., spin accumulation. Once the spin voltage is converted into the electric voltage by inverse spin Hall effect in attached metal films such as Pt, the electric voltage is obtained from heat energy [4-5]. This is called the spin Seebeck effect. Here, we present the linear-response theory of spin Seebeck effect based on the fluctuation-dissipation theorem [6-8] and discuss a variety of the devices. [4pt] [1] S. Maekawa et al, Physics of Transition Metal Oxides (Springer, 2004). [0pt] [2] S. Maekawa: Nature Materials 8, 777 (2009). [0pt] [3] Concept in Spin Electronics, eds. S. Maekawa (Oxford University Press, 2006). [0pt] [4] K. Uchida et al., Nature 455, 778 (2008). [0pt] [5] K. Uchida et al., Nature Materials 9, 894 (2010) [0pt] [6] H. Adachi et al., APL 97, 252506 (2010) and Phys. Rev. B 83, 094410 (2011). [0pt] [7] J. Ohe et al., Phys. Rev. B (2011) [0pt] [8] K. Uchida et al., Appl. Phys. Lett. 97, 104419 (2010).

  16. Anisotropic spin motive force in multi-layered Dirac fermion system, α-(BEDT-TTF)2I3

    International Nuclear Information System (INIS)

    Kubo, K; Morinari, T

    2015-01-01

    We investigate the anisotropic spin motive force in α-(BEDT-TTF) 2 I 3 , which is a multi-layered massless Dirac fermion system under pressure. Assuming the interlayer antiferromagnetic interaction and the interlayer anisotropic ferromagnetic interaction, we numerically examine the spin ordered state of the ground state using the steepest descent method. The anisotropic interaction leads to the anisotropic spin ordered state. We calculate the spin motive force produced by the anisotropic spin texture. The result quantitatively agrees with the experiment. (paper)

  17. Colour and texture associations in voice-induced synaesthesia

    Directory of Open Access Journals (Sweden)

    Anja eMoos

    2013-09-01

    Full Text Available Voice-induced synaesthesia, a form of synaesthesia in which synaesthetic perceptions are induced by the sounds of people’s voices, appears to be relatively rare and has not been systematically studied. In this study we investigated the synaesthetic colour and visual texture perceptions experienced in response to different types of voice quality (e.g. nasal, whisper, falsetto. Experiences of three different groups – self-reported voice synaesthetes, phoneticians and controls – were compared using both qualitative and quantitative analysis in a study conducted online. Whilst, in the qualitative analysis, synaesthetes used more colour and texture terms to describe voices than either phoneticians or controls, only weak differences, and many similarities, between groups were found in the quantitative analysis. Notable consistent results between groups were the matching of higher speech fundamental frequencies with lighter and redder colours, the matching of whispery voices with smoke-like textures and the matching of harsh and creaky voices with textures resembling dry cracked soil. These data are discussed in the light of current thinking about definitions and categorizations of synaesthesia, especially in cases where individuals apparently have a range of different synaesthetic inducers.

  18. Dry texturing of solar cells

    Science.gov (United States)

    Sopori, Bhushan L.

    1994-01-01

    A textured backside of a semiconductor device for increasing light scattering and absorption in a semiconductor substrate is accomplished by applying infrared radiation to the front side of a semiconductor substrate that has a metal layer deposited on its backside in a time-energy profile that first produces pits in the backside surface and then produces a thin, highly reflective, low resistivity, epitaxial alloy layer over the entire area of the interface between the semiconductor substrate and a metal contact layer. The time-energy profile includes ramping up to a first energy level and holding for a period of time to create the desired pit size and density and then rapidly increasing the energy to a second level in which the entire interface area is melted and alloyed quickly. After holding the second energy level for a sufficient time to develop the thin alloy layer over the entire interface area, the energy is ramped down to allow epitaxial crystal growth in the alloy layer. The result is a textured backside an optically reflective, low resistivity alloy interface between the semiconductor substrate and the metal electrical contact layer.

  19. Cascaded Amplitude Modulations in Sound Texture Perception

    Directory of Open Access Journals (Sweden)

    Richard McWalter

    2017-09-01

    Full Text Available Sound textures, such as crackling fire or chirping crickets, represent a broad class of sounds defined by their homogeneous temporal structure. It has been suggested that the perception of texture is mediated by time-averaged summary statistics measured from early auditory representations. In this study, we investigated the perception of sound textures that contain rhythmic structure, specifically second-order amplitude modulations that arise from the interaction of different modulation rates, previously described as “beating” in the envelope-frequency domain. We developed an auditory texture model that utilizes a cascade of modulation filterbanks that capture the structure of simple rhythmic patterns. The model was examined in a series of psychophysical listening experiments using synthetic sound textures—stimuli generated using time-averaged statistics measured from real-world textures. In a texture identification task, our results indicated that second-order amplitude modulation sensitivity enhanced recognition. Next, we examined the contribution of the second-order modulation analysis in a preference task, where the proposed auditory texture model was preferred over a range of model deviants that lacked second-order modulation rate sensitivity. Lastly, the discriminability of textures that included second-order amplitude modulations appeared to be perceived using a time-averaging process. Overall, our results demonstrate that the inclusion of second-order modulation analysis generates improvements in the perceived quality of synthetic textures compared to the first-order modulation analysis considered in previous approaches.

  20. NMR in an electric field: A bulk probe of the hidden spin and orbital polarizations

    OpenAIRE

    Ramírez-Ruiz, Jorge; Boutin, Samuel; Garate, Ion

    2017-01-01

    Recent theoretical work has established the presence of hidden spin and orbital textures in non-magnetic materials with inversion symmetry. Here, we propose that these textures can be detected by nuclear magnetic resonance (NMR) measurements carried out in the presence of an electric field. In crystals with hidden polarizations, a uniform electric field produces a staggered magnetic field that points to opposite directions at atomic sites related by spatial inversion. As a result, the NMR res...

  1. Spin-Mechatronics

    Science.gov (United States)

    Matsuo, Mamoru; Saitoh, Eiji; Maekawa, Sadamichi

    2017-01-01

    We investigate the interconversion phenomena between spin and mechanical angular momentum in moving objects. In particular, the recent results on spin manipulation and spin-current generation by mechanical motion are examined. In accelerating systems, spin-dependent gauge fields emerge, which enable the conversion from mechanical angular momentum into spins. Such a spin-mechanical effect is predicted by quantum theory in a non-inertial frame. Experiments which confirm the effect, i.e., the resonance frequency shift in nuclear magnetic resonance, the stray field measurement of rotating metals, and electric voltage generation in liquid metals, are discussed.

  2. Interfacial spin-orbit splitting and current-driven spin torque in anisotropic tunnel junctions

    KAUST Repository

    Manchon, Aurelien

    2011-05-17

    Spin transport in magnetic tunnel junctions comprising a single magnetic layer in the presence of interfacial spin-orbit interaction (SOI) is investigated theoretically. Due to the presence of interfacial SOI, a current-driven spin torque can be generated at the second order in SOI, even in the absence of an external spin polarizer. This torque possesses two components, one in plane and one perpendicular to the plane of rotation, that can induce either current-driven magnetization switching from an in-plane to out-of-plane configuration or magnetization precessions, similar to spin transfer torque in spin valves. Consequently, it appears that it is possible to control the magnetization steady state and dynamics by either varying the bias voltage or electrically modifying the SOI at the interface.

  3. Snakes and spin rotators

    International Nuclear Information System (INIS)

    Lee, S.Y.

    1990-01-01

    The generalized snake configuration offers advantages of either shorter total snake length and smaller orbit displacement in the compact configuration or the multi-functions in the split configuration. We found that the compact configuration can save about 10% of the total length of a snake. On other hand, the spilt snake configuration can be used both as a snake and as a spin rotator for the helicity state. Using the orbit compensation dipoles, the spilt snake configuration can be located at any distance on both sides of the interaction point of a collider provided that there is no net dipole rotation between two halves of the snake. The generalized configuration is then applied to the partial snake excitation. Simple formula have been obtained to understand the behavior of the partial snake. Similar principle can also be applied to the spin rotators. We also estimate the possible snake imperfections are due to various construction errors of the dipole magnets. Accuracy of field error of better than 10 -4 will be significant. 2 refs., 5 figs

  4. Two-dimensional spin diffusion in multiterminal lateral spin valves

    Science.gov (United States)

    Saha, D.; Basu, D.; Holub, M.; Bhattacharya, P.

    2008-01-01

    The effects of two-dimensional spin diffusion on spin extraction in lateral semiconductor spin valves have been investigated experimentally and theoretically. A ferromagnetic collector terminal of variable size is placed between the ferromagnetic electron spin injector and detector of a conventional lateral spin valve for spin extraction. It is observed that transverse spin diffusion beneath the collector terminal plays an important role along with the conventional longitudinal spin diffusion in describing the overall transport of spin carriers. Two-dimensional spin diffusion reduces the perturbation of the channel electrochemical potentials and improves spin extraction.

  5. Contrast-negation and texture synthesis differentially disrupt natural texture appearance

    Directory of Open Access Journals (Sweden)

    Benjamin J Balas

    2012-11-01

    Full Text Available Natural textures have characteristic image statistics that make them discriminable from unnatural textures. For example, both contrast-negation and texture synthesis alter the appearance of natural textures even though each manipulation preserves some features while disrupting others. Here, we examined the extent to which contrast-negation and texture synthesis each introduce or remove critical perceptual features for discriminating unnatural textures from natural textures. We find that both manipulations remove information that observers use for distinguishing natural textures from transformed versions of the same patterns, but do so in different ways. Texture synthesis removes information that is relevant for discrimination in both abstract patterns and ecologically valid textures, and we also observe a category-dependent asymmetry for identifying an oddball real texture among synthetic distractors. Contrast negation exhibits no such asymmetry, and also does not impact discrimination performance in abstract patterns. We discuss our results in the context of the visual system’s tuning to ecologically relevant patterns and other results describing sensitivity to higher-order statistics in texture patterns.

  6. Crystallographic Texture in Ceramics and Metals.

    Science.gov (United States)

    Vaudin, M D

    2001-01-01

    Preferred crystallographic orientation, or texture, occurs almost universally, both in natural and man-made systems. Many components and devices in electronic and magnetic systems are fabricated from materials that have crystallographic texture. With the rapidly increasing use of thin film technology, where sharp axisymmetric crystallographic texture normal to the film plane is frequently observed, the occurrence and impact of texture are rising. Thin film applications in which the texture of the material plays a key role in determining properties and performance are broad: complex oxides in random access memory devices, ZnO thin film resonators for cell phone applications, metallic alloys in magnetic recording media, and Al and Cu interconnects in integrated circuits are but a few examples. Texture is established during the synthesis or post-synthesis heat treatment of a material and thus has a strong dependence upon processing history. Accurate measurement of texture is not simple and a variety of tools and approaches are being actively employed in texture studies. X-ray, neutron and electron diffraction based techniques are practiced around the world at varying levels of complexity with regard to equipment and analysis methods. Despite the well-documented existence of these varied approaches, many reported texture measurements on electronic materials are based solely on the relative intensities of conventional θ-2θ x-ray diffraction peaks, which typically yield inaccurate results. NIST has developed quantitative texture measurement techniques that employ equipment commonly available in most industrial and academic settings. A number of examples of texture measurement in ceramic and metal systems will be presented, taken from the historical development and application of these techniques at NIST over the past 7 years.

  7. Dynamic nuclear spin polarization

    Energy Technology Data Exchange (ETDEWEB)

    Stuhrmann, H.B. [GKSS-Forschungszentrum Geesthacht GmbH (Germany)

    1996-11-01

    Polarized neutron scattering from dynamic polarized targets has been applied to various hydrogenous materials at different laboratories. In situ structures of macromolecular components have been determined by nuclear spin contrast variation with an unprecedented precision. The experiments of selective nuclear spin depolarisation not only opened a new dimension to structural studies but also revealed phenomena related to propagation of nuclear spin polarization and the interplay of nuclear polarisation with the electronic spin system. The observation of electron spin label dependent nuclear spin polarisation domains by NMR and polarized neutron scattering opens a way to generalize the method of nuclear spin contrast variation and most importantly it avoids precontrasting by specific deuteration. It also likely might tell us more about the mechanism of dynamic nuclear spin polarisation. (author) 4 figs., refs.

  8. Assessment of Multibeam Backscatter Texture Analysis for Seafloor Sediment Classification

    Science.gov (United States)

    Samsudin, S. A.; Hasan, R. C.

    2017-10-01

    Recently, there have been many debates to analyse backscatter data from multibeam echosounder system (MBES) for seafloor classifications. Among them, two common methods have been used lately for seafloor classification; (1) signal-based classification method which using Angular Range Analysis (ARA) and Image-based texture classification method which based on derived Grey Level Co-occurrence Matrices (GLCMs). Although ARA method could predict sediment types, its low spatial resolution limits its use with high spatial resolution dataset. Texture layers from GLCM on the other hand does not predict sediment types, but its high spatial resolution can be useful for image analysis. The objectives of this study are; (1) to investigate the correlation between MBES derived backscatter mosaic textures with seafloor sediment type derived from ARA method, and (2) to identify which GLCM texture layers have high similarities with sediment classification map derived from signal-based classification method. The study area was located at Tawau, covers an area of 4.7 km2, situated off the channel in the Celebes Sea between Nunukan Island and Sebatik Island, East Malaysia. First, GLCM layers were derived from backscatter mosaic while sediment types (i.e. sediment map with classes) was also constructed using ARA method. Secondly, Principal Component Analysis (PCA) was used determine which GLCM layers contribute most to the variance (i.e. important layers). Finally, K-Means clustering algorithm was applied to the important GLCM layers and the results were compared with classes from ARA. From the results, PCA has identified that GLCM layers of Correlation, Entropy, Contrast and Mean contributed to the 98.77 % of total variance. Among these layers, GLCM Mean showed a good agreement with sediment classes from ARA sediment map. This study has demonstrated different texture layers have different characterisation factors for sediment classification and proper analysis is needed before

  9. Mechanical seal with textured sidewall

    Energy Technology Data Exchange (ETDEWEB)

    Khonsari, Michael M.; Xiao, Nian

    2017-02-14

    The present invention discloses a mating ring, a primary ring, and associated mechanical seal having superior heat transfer and wear characteristics. According to an exemplary embodiment of the present invention, one or more dimples are formed onto the cylindrical outer surface of a mating ring sidewall and/or a primary ring sidewall. A stationary mating ring for a mechanical seal assembly is disclosed. Such a mating ring comprises an annular body having a central axis and a sealing face, wherein a plurality of dimples are formed into the outer circumferential surface of the annular body such that the exposed circumferential surface area of the annular body is increased. The texture added to the sidewall of the mating ring yields superior heat transfer and wear characteristics.

  10. On the electrodynamics of spinning particles

    International Nuclear Information System (INIS)

    Holten, J.W. van

    1990-01-01

    The electrodynamics of spinning point particles is considered. A modification of the Lorentz force law is introduced which can be interpreted as a classical limit of the Dirac-Klein-Gordon equation. An improved version of the inhomogeneous Maxwell equations is constructed to describe the classical fields of spinning particles. Both classical and quantum electrodynamics are shown to predict relativistic time-dilatation effects for spinning particles in an electromagnetic field, even in the limit of zero velocity. The life-time of unstable charged particles moving in a Coulomb field is computed for both spin-zero and spin-half particles. Comparison shows spin effects to be present but relatively small. The magnitude of further spin-dependent correction from hyperfine interactions is computed. A measurement of the life-time of muons in atomic bound states separated by such spin-dependent hyperfine interactions would provide a clean test for the effect predicted. Similar effects are shown to arise in non-abelian gauge theories such as QCD. (author). 18 refs

  11. A New Spin on Photoemission Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jozwiak, Chris [Univ. of California, Berkeley, CA (United States)

    2008-12-01

    The electronic spin degree of freedom is of general fundamental importance to all matter. Understanding its complex roles and behavior in the solid state, particularly in highly correlated and magnetic materials, has grown increasingly desirable as technology demands advanced devices and materials based on ever stricter comprehension and control of the electron spin. However, direct and efficient spin dependent probes of electronic structure are currently lacking. Angle Resolved Photoemission Spectroscopy (ARPES) has become one of the most successful experimental tools for elucidating solid state electronic structures, bolstered by-continual breakthroughs in efficient instrumentation. In contrast, spin-resolved photoemission spectroscopy has lagged behind due to a lack of similar instrumental advances. The power of photoemission spectroscopy and the pertinence of electronic spin in the current research climate combine to make breakthroughs in Spin and Angle Resolved Photoemission Spectroscopy (SARPES) a high priority . This thesis details the development of a unique instrument for efficient SARPES and represents a radical departure from conventional methods. A custom designed spin polarimeter based on low energy exchange scattering is developed, with projected efficiency gains of two orders of magnitude over current state-of-the-art polarimeters. For energy analysis, the popular hemispherical analyzer is eschewed for a custom Time-of-Flight (TOF) analyzer offering an additional order of magnitude gain in efficiency. The combined instrument signifies the breakthrough needed to perform the high resolution SARPES experiments necessary for untangling the complex spin-dependent electronic structures central to today's condensed matter physics.

  12. Cool Polar Bears: Dabbing on the Texture

    Science.gov (United States)

    O'Connell, Jean

    2011-01-01

    In this article, the author describes how her second-graders created their cool polar bears. The students used the elements of shape and texture to create the bears. They used Monet's technique of dabbing paint so as to give the bear some texture on his fur.

  13. On the origin of recrystallization textures

    Indian Academy of Sciences (India)

    Unknown

    specially oriented grains have a high mobility boundary and thus can migrate faster and grow to a larger size as compared to random orientations thus contributing to the final recrystallization texture. In FCC metals and alloys like aluminium, cube orientation [(001) 〈100〉] is the recrystallization texture component.

  14. On texture formation of chromium electrodeposits

    DEFF Research Database (Denmark)

    Nielsen, Christian Bergenstof; Leisner, Peter; Horsewell, Andy

    1998-01-01

    The microstructure, texture and hardness of electrodeposited hard, direct current (DC) chromium and pulsed reversed chromium has been investigated. These investigations suggest that the growth and texture of hard chromium is controlled by inhibition processes and reactions. Further, it has been...... established that codeposition of Cr2O3 nanoparticles is a general feature of DC chromium electrodeposition....

  15. Friction tensor concept for textured surfaces

    Indian Academy of Sciences (India)

    Depending on the sliding direction the coefficient of friction varies between maximum and minimum for textured surfaces. For random surfaces without any texture the friction coefficient becomes independent of the sliding direction. This paper proposes the concept of a friction tensor analogous to the heat conduction tensor ...

  16. On the origin of recrystallization textures

    Indian Academy of Sciences (India)

    Unknown

    specially oriented grains have a high mobility boundary and thus can migrate faster and grow to a larger size as compared to random orientations thus contributing to the final recrystallization texture. In FCC metals and alloys like aluminium, cube orientation [(001) 〈100〉] is the recrystallization texture component. In the ...

  17. Cascaded Amplitude Modulations in Sound Texture Perception

    DEFF Research Database (Denmark)

    McWalter, Richard Ian; Dau, Torsten

    2017-01-01

    Sound textures, such as crackling fire or chirping crickets, represent a broad class of sounds defined by their homogeneous temporal structure. It has been suggested that the perception of texture is mediated by time-averaged summary statistics measured from early auditory representations...

  18. Texture design for light touch perception

    NARCIS (Netherlands)

    Zhang, S.; Zeng, X.; Matthews, D.T.A.; Igartua, A.; Rodriguez Vidal, E.; Fortes, J. Contreras; Van Der Heide, E.

    This study focused on active light touch with predefined textures specially-designed for tactile perception. The counter-body material is stainless steel sheet. Three geometric structures (grid, crater and groove) were fabricated by pulsed laser surface texturing. A total number of twenty volunteers

  19. Spin-Hall nano-oscillator: A micromagnetic study

    Energy Technology Data Exchange (ETDEWEB)

    Giordano, A.; Azzerboni, B.; Finocchio, G. [Department of Electronic Engineering, Industrial Chemistry and Engineering, University of Messina, C.da di Dio, I-98166 Messina (Italy); Carpentieri, M. [Department of Electrical and Information Engineering, Politecnico of Bari, via E. Orabona 4, I-70125 Bari (Italy); Laudani, A. [Department of Engineering, University of Roma Tre, via V. Volterra 62, I-00146 Roma (Italy); Gubbiotti, G. [Istituto Officina dei Materiali del CNR (CNR-IOM), Unità di Perugia c/o Dipartimento di Fisica e Geologia, Via A. Pascoli, 06123 Perugia (Italy)

    2014-07-28

    This Letter studies the dynamical behavior of spin-Hall nanoscillators from a micromagnetic point of view. The model parameters have been identified by reproducing recent experimental data quantitatively. Our results indicate that a strongly localized mode is observed for in-plane bias fields such as in the experiments, while predict the excitation of an asymmetric propagating mode for large enough out-of plane bias field similarly to what observed in spin-torque nanocontact oscillators. Our findings show that spin-Hall nanoscillators can find application as spin-wave emitters for magnonic applications where spin waves are used for transmission and processing information on nanoscale.

  20. Spin at Lausanne

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    From 25 September to 1 October, some 150 spin enthusiasts gathered in Lausanne for the 1980 International Symposium on High Energy Physics with Polarized Beams and Polarized Targets. The programme was densely packed, covering physics interests with spin as well as the accelerator and target techniques which make spin physics possible

  1. Spin-torque transistor

    NARCIS (Netherlands)

    Bauer, G.E.W.; Brataas, A.; Tserkovnyak, Y.; Van Wees, B.J.

    2003-01-01

    A magnetoelectronic thin-film transistor is proposed that can display negative differential resistance and gain. The working principle is the modulation of the soure–drain current in a spin valve by the magnetization of a third electrode, which is rotated by the spin-torque created by a control spin

  2. Spin Orbit Torque in Ferromagnetic Semiconductors

    KAUST Repository

    Li, Hang

    2016-06-21

    Electrons not only have charges but also have spin. By utilizing the electron spin, the energy consumption of electronic devices can be reduced, their size can be scaled down and the efficiency of `read\\' and `write\\' in memory devices can be significantly improved. Hence, the manipulation of electron spin in electronic devices becomes more and more appealing for the advancement of microelectronics. In spin-based devices, the manipulation of ferromagnetic order parameter using electrical currents is a very useful means for current-driven operation. Nowadays, most of magnetic memory devices are based on the so-called spin transfer torque, which stems from the spin angular momentum transfer between a spin-polarized current and the magnetic order parameter. Recently, a novel spin torque effect, exploiting spin-orbit coupling in non-centrosymmetric magnets, has attracted a massive amount of attention. This thesis addresses the nature of spin-orbit coupled transport and torques in non-centrosymmetric magnetic semiconductors. We start with the theoretical study of spin orbit torque in three dimensional ferromagnetic GaMnAs. Using the Kubo formula, we calculate both the current-driven field-like torque and anti-damping-like torque. We compare the numerical results with the analytical expressions in the model case of a magnetic Rashba two-dimensional electron gas. Parametric dependencies of the different torque components and similarities to the analytical results of the Rashba two-dimensional electron gas in the weak disorder limit are described. Subsequently we study spin-orbit torques in two dimensional hexagonal crystals such as graphene, silicene, germanene and stanene. In the presence of staggered potential and exchange field, the valley degeneracy can be lifted and we obtain a valley-dependent Berry curvature, leading to a tunable antidamping torque by controlling the valley degree of freedom. This thesis then addresses the influence of the quantum spin Hall

  3. FCC Rolling Textures Reviewed in the Light of Quantitative Comparisons between Simulated and Experimental Textures

    DEFF Research Database (Denmark)

    Wierzbanowski, Krzysztof; Wroński, Marcin; Leffers, Torben

    2014-01-01

    The crystallographic texture of metallic materials has a very strong effect on the properties of the materials. In the present article, we look at the rolling textures of fcc metals and alloys, where the classical problem is the existence of two different types of texture, the "copper-type texture......} slip without or with deformation twinning, but we also consider slip on other slip planes and slip by partial dislocations. We consistently make quantitative comparison of the simulation results and the experimental textures by means of a scalar correlation factor. We find that the development...

  4. High spin spectroscopy of Pr

    Indian Academy of Sciences (India)

    2001-07-31

    Jul 31, 2001 ... High spin states; nuclear structure; gamma-ray spectroscopy;. ½¿. Pr energy levels. PACS Nos 21.10.-k; 23.20.-g; 27.60.+j; 29.30.Kv. 1. Introduction. The transitional nuclei in the A. ½ ¼ region with N between 77 and 81 are interesting as it offer good scope to look for possible shape changes, similar to ...

  5. Portfolios with nonlinear constraints and spin glasses

    Science.gov (United States)

    Gábor, Adrienn; Kondor, I.

    1999-12-01

    In a recent paper Galluccio, Bouchaud and Potters demonstrated that a certain portfolio problem with a nonlinear constraint maps exactly onto finding the ground states of a long-range spin glass, with the concomitant nonuniqueness and instability of the optimal portfolios. Here we put forward geometric arguments that lead to qualitatively similar conclusions, without recourse to the methods of spin glass theory, and give two more examples of portfolio problems with convex nonlinear constraints.

  6. The Honeycomb illusion: Uniform textures not perceived as such

    Directory of Open Access Journals (Sweden)

    Marco Bertamini

    2016-07-01

    Full Text Available We present a series of patterns, in which texture is perceived differently at fixation in comparison to the periphery, such that a physically uniform stimulus yields a nonuniform percept. We call this the Honeycomb illusion, and we discuss it in relation to the similar Extinction illusion (Ninio & Stevens, 2000. The effect remains strong despite multiple fixations, dynamic changes, and manipulations of the size of texture elements. We discuss the phenomenon in relation to how vision achieves a detailed and stable representation of the environment despite changes in retinal spatial resolution and dramatic changes across saccades. The Honeycomb illusion complements previous related observations in suggesting that this representation is not necessarily based on multiple fixations (i.e., memory or on extrapolation from information available to central vision.

  7. Multiresolution texture models for brain tumor segmentation in MRI.

    Science.gov (United States)

    Iftekharuddin, Khan M; Ahmed, Shaheen; Hossen, Jakir

    2011-01-01

    In this study we discuss different types of texture features such as Fractal Dimension (FD) and Multifractional Brownian Motion (mBm) for estimating random structures and varying appearance of brain tissues and tumors in magnetic resonance images (MRI). We use different selection techniques including KullBack - Leibler Divergence (KLD) for ranking different texture and intensity features. We then exploit graph cut, self organizing maps (SOM) and expectation maximization (EM) techniques to fuse selected features for brain tumors segmentation in multimodality T1, T2, and FLAIR MRI. We use different similarity metrics to evaluate quality and robustness of these selected features for tumor segmentation in MRI for real pediatric patients. We also demonstrate a non-patient-specific automated tumor prediction scheme by using improved AdaBoost classification based on these image features.

  8. Spin physics in semiconductors

    CERN Document Server

    2017-01-01

    This book offers an extensive introduction to the extremely rich and intriguing field of spin-related phenomena in semiconductors. In this second edition, all chapters have been updated to include the latest experimental and theoretical research. Furthermore, it covers the entire field: bulk semiconductors, two-dimensional semiconductor structures, quantum dots, optical and electric effects, spin-related effects, electron-nuclei spin interactions, Spin Hall effect, spin torques, etc. Thanks to its self-contained style, the book is ideally suited for graduate students and researchers new to the field.

  9. Textured Image Demoiréing via Signal Decomposition and Guided Filtering.

    Science.gov (United States)

    Yang, Jingyu; Liu, Fanglei; Yue, Huanjing; Fu, Xiaomei; Hou, Chunping; Wu, Feng

    2017-04-27

    Moir´e artifacts are generally caused by the interference between the overlap of the sensor's sampling grid and high-frequency (nearly) periodic textures, and heavily affect the image quality. However, it is difficult to effectively remove moir´e artifacts from textured images as the structure of moir´e patterns is similar to that of textures in some sense. In this paper, we propose a novel textured image demoir´eing method by signal decomposition and guided filtering. Given a textured image with moir´e artifacts, we first remove moir´e artifacts in the green (G) channel using the proposed low-rank and sparse matrix decomposition model. This model regularizes the texture layer by the low-rank prior in spatial domain and the moir´e layer by sparse representation in frequency domain. An alternating direction method under the augmented Lagrangian multiplier (ADM-ALM) framework is used to solve the matrix decomposition model. Then, since the red (R) and blue (B) channels are more heavily polluted by moir´e artifacts than the G channel, we propose to remove moir´e artifacts in its R and B channels via guided filtering by the obtained texture layer of the G channel. Experimental results demonstrate that our method outperforms state-of-the-art methods for both synthetic and real images.

  10. Chemometric approach to texture profile analysis of kombucha fermented milk products.

    Science.gov (United States)

    Malbaša, Radomir; Jevrić, Lidija; Lončar, Eva; Vitas, Jasmina; Podunavac-Kuzmanović, Sanja; Milanović, Spasenija; Kovačević, Strahinja

    2015-09-01

    In the present work, relationships between the textural characteristics of fermented milk products obtained by kombucha inoculums with various teas were investigated by using chemometric analysis. The presented data which describe numerically the textural characteristics (firmness, consistency, cohesiveness and index of viscosity) were analysed. The quadratic correlation was determined between the textural characteristics of fermented milk products obtained at fermentation temperatures of 40 and 43 °C, using milk with 0.8, 1.6 and 2.8% milk fat and kombucha inoculums cultivated on the extracts of peppermint, stinging nettle, wild thyme and winter savory. Hierarchical cluster analysis (HCA) was performed to identify the similarities among the fermented products. The best mathematical models predicting the textural characteristics of investigated samples were developed. The results of this study indicate that textural characteristics of sample based on winter savory have a significant effect on textural characteristics of samples based on peppermint, stinging nettle and wild thyme, which can be very useful in the determination of products texture profile.

  11. Spin matching conditions in large electron storage rings with purely horizontal beam polarization

    International Nuclear Information System (INIS)

    Rossmanith, R.

    1990-08-01

    In a storage ring with a purely horizontal spin and a Siberian Snake, the spin matching conditions are similar to the spin matching conditions for vertical polarization; a combination of beam bumps has to be found which compensate the depolarizing effects. These bumps compensate the random emission of synchrotron emission on the spin. The aim of this paper is to define spin matching conditions that compensate this effect

  12. Spin matching conditions in large electron storage rings with purely horizontal beam polarization

    Energy Technology Data Exchange (ETDEWEB)

    Rossmanith, R.

    1990-08-01

    In a storage ring with a purely horizontal spin and a Siberian Snake, the spin matching conditions are similar to the spin matching conditions for vertical polarization; a combination of beam bumps has to be found which compensate the depolarizing effects. These bumps compensate the random emission of synchrotron emission on the spin. The aim of this paper is to define spin matching conditions that compensate this effect.

  13. Solid-texture synthesis: a survey.

    Science.gov (United States)

    Pietroni, Nico; Cignoni, Paolo; Otaduy, Miguel; Scopigno, Roberto

    2010-01-01

    Solid textures are an efficient way to compactly represent 3D objects' external and internal appearance, providing practical advantages over classic 2D texturing. Two main methods exist for synthesizing solid textures. Procedural methods obtain colors through functions that algorithmically encode the texture's appearance and structural properties. Example-based methods capture and replicate the appearance as described by a set of input exemplars. These methods can also be classified as boundary independent or boundary dependent. For boundary-independent methods, the shape of the object to be textured is irrelevant, and texture information can be freely generated for each point in the space. Boundary-dependent methods conform the synthesis process to the object's actual shape so that they can exploit this information to orient and guide texture generation. This article reviews the different methodologies' strengths and weaknesses, the classes of appearances they can successfully synthesize, and failure cases. In particular, it focuses on boundary-independent methods' advantages and drawbacks compared to boundary-dependent methods.

  14. Probing Majorana neutrino textures at DUNE

    Science.gov (United States)

    Bora, Kalpana; Borah, Debasish; Dutta, Debajyoti

    2017-10-01

    We study the possibility of probing different texture zero neutrino mass matrices at the long baseline neutrino experiment DUNE, particularly focusing on its sensitivity to the octant of atmospheric mixing angle θ23 and leptonic Dirac C P phase δcp. Assuming a diagonal charged lepton basis and Majorana nature of light neutrinos, we first classify the possible light neutrino mass matrices with one and two texture zeros and then numerically evaluate the parameter space which satisfies the texture zero conditions. Apart from using the latest global fit 3 σ values of neutrino oscillation parameters, we also use the latest bound on the sum of absolute neutrino masses (∑i |mi|) from the Planck mission data and the updated bound on effective neutrino mass Me e from neutrinoless double beta decay (0 ν β β ) experiments to find the allowed Majorana texture zero mass matrices. For the allowed texture zero mass matrices from all these constraints, we then feed the corresponding light neutrino parameter values satisfying the texture zero conditions into the numerical analysis in order to study the capability of DUNE to allow or exclude them once it starts taking data. We find that DUNE will be able to exclude some of these texture zero mass matrices which restrict (θ23-δcp) to a very specific range of values, depending on the values of the parameters that nature has chosen.

  15. Fresh fruit: microstructure, texture, and quality

    Science.gov (United States)

    Wood, Delilah F.; Imam, Syed H.; Orts, William J.; Glenn, Gregory M.

    2009-05-01

    Fresh-cut produce has a huge following in today's supermarkets. The trend follows the need to decrease preparation time as well as the desire to follow the current health guidelines for consumption of more whole "heart-healthy" foods. Additionally, consumers are able to enjoy a variety of fresh produce regardless of the local season because produce is now shipped world-wide. However, most fruits decompose rapidly once their natural packaging has been disrupted by cutting. In addition, some intact fruits have limited shelf-life which, in turn, limits shipping and storage. Therefore, a basic understanding of how produce microstructure relates to texture and how microstructure changes as quality deteriorates is needed to ensure the best quality in the both the fresh-cut and the fresh produce markets. Similarities between different types of produce include desiccation intolerance which produces wrinkling of the outer layers, cracking of the cuticle and increased susceptibility to pathogen invasion. Specific examples of fresh produce and their corresponding ripening and storage issues, and degradation are shown in scanning electron micrographs.

  16. Role of spin diffusion in current-induced domain wall motion for disordered ferromagnets

    KAUST Repository

    Akosa, Collins Ashu

    2015-03-12

    Current-induced spin transfer torque and magnetization dynamics in the presence of spin diffusion in disordered magnetic textures is studied theoretically. We demonstrate using tight-binding calculations that weak, spin-conserving impurity scattering dramatically enhances the nonadiabaticity. To further explore this mechanism, a phenomenological drift-diffusion model for incoherent spin transport is investigated. We show that incoherent spin diffusion indeed produces an additional spatially dependent torque of the form ∼∇2[m×(u⋅∇)m]+ξ∇2[(u⋅∇)m], where m is the local magnetization direction, u is the direction of injected current, and ξ is a parameter characterizing the spin dynamics (precession, dephasing, and spin-flip). This torque, which scales as the inverse square of the domain wall width, only weakly enhances the longitudinal velocity of a transverse domain wall but significantly enhances the transverse velocity of vortex walls. The spatial-dependent spin transfer torque uncovered in this study is expected to have significant impact on the current-driven motion of abrupt two-dimensional textures such as vortices, skyrmions, and merons.

  17. Texture and wettability of metallic lotus leaves

    Science.gov (United States)

    Frankiewicz, C.; Attinger, D.

    2016-02-01

    Superhydrophobic surfaces with the self-cleaning behavior of lotus leaves are sought for drag reduction and phase change heat transfer applications. These superrepellent surfaces have traditionally been fabricated by random or deterministic texturing of a hydrophobic material. Recently, superrepellent surfaces have also been made from hydrophilic materials, by deterministic texturing using photolithography, without low-surface energy coating. Here, we show that hydrophilic materials can also be made superrepellent to water by chemical texturing, a stochastic rather than deterministic process. These metallic surfaces are the first analog of lotus leaves, in terms of wettability, texture and repellency. A mechanistic model is also proposed to describe the influence of multiple tiers of roughness on wettability and repellency. This demonstrated ability to make hydrophilic materials superrepellent without deterministic structuring or additional coatings opens the way to large scale and robust manufacturing of superrepellent surfaces.Superhydrophobic surfaces with the self-cleaning behavior of lotus leaves are sought for drag reduction and phase change heat transfer applications. These superrepellent surfaces have traditionally been fabricated by random or deterministic texturing of a hydrophobic material. Recently, superrepellent surfaces have also been made from hydrophilic materials, by deterministic texturing using photolithography, without low-surface energy coating. Here, we show that hydrophilic materials can also be made superrepellent to water by chemical texturing, a stochastic rather than deterministic process. These metallic surfaces are the first analog of lotus leaves, in terms of wettability, texture and repellency. A mechanistic model is also proposed to describe the influence of multiple tiers of roughness on wettability and repellency. This demonstrated ability to make hydrophilic materials superrepellent without deterministic structuring or additional

  18. Similarity transformations of MAPs

    Directory of Open Access Journals (Sweden)

    Andersen Allan T.

    1999-01-01

    Full Text Available We introduce the notion of similar Markovian Arrival Processes (MAPs and show that the event stationary point processes related to two similar MAPs are stochastically equivalent. This holds true for the time stationary point processes too. We show that several well known stochastical equivalences as e.g. that between the H 2 renewal process and the Interrupted Poisson Process (IPP can be expressed by the similarity transformations of MAPs. In the appendix the valid region of similarity transformations for two-state MAPs is characterized.

  19. Shaping drops with textured surfaces

    Science.gov (United States)

    Ehlinger, Quentin; Biance, Anne-Laure; Ybert, Christophe

    2017-11-01

    When a drop impacts a substrate, it can behave differently depending on the nature of the surface and of the liquid (spreading, bouncing, resting, splashing ...). Understanding these behaviors is crucial to predict the drop morphology during and after impact. Whereas surface wettability has extensively been studied, the effect of surface roughness remains hardly explored. In this work, we consider the impact of a drop in a pure non-wetting situation by using superheated substrates i.e. in the Leidenfrost regime. The surface texture consists of a well-controlled microscopic defect shaped with photolithography on a smooth silicon wafer. Different regimes are observed, depending on the distance between the defect and the impact point and the defect size. Comparing the lamella thickness versus the defect height proves relevant as the transition criteria between regimes. Others characteristics of the drop behavior (direction of satellite droplet ejection, lamella rupture) are also well captured by inertial/capillary models. Drop impacts on multiple defects are also investigated and drop shape well predicted considering the interactions between the local flow and the defects.

  20. Texture investigation by neutron diffraction

    International Nuclear Information System (INIS)

    Feldmann, K.

    1987-01-01

    In the conventional angle dispersive neutron diffraction a monochromatic neutron beam is used. The pole figures under investigation have to be scanned one after another. The commonly applied angle dispersive method is limited to the consideration of Bragg reflection being isolated in the diffraction pattern. The application of multidetectors or position sensitive detectors is discussed. In the neutron time-of-flight (TOF) diffraction a white pulsed neutron beam allows one to satisfy the Bragg law for all lattice spacing at a fixed scattering angle. The main charateristics of the TOF diffraction experiment are shortly outlined. In this method all non-forbidden Bragg reflections are recorded in one pattern simultaneously. The TOF technique is well-suited to study low symmetric or multiphased specimens, especially geological materials, requiring a large number of pole figures for mathematical texture analysis. Multidetector systems can be used to shorten the necessary time for experiments. The registration of all Bragg reflections of fixed scattering geometry is equivalent to the information of the inverse pole figure for the corresponding sample position. Having short exposition times this approach can be applied for in-situ investigations. The magnetic moments of neutrons can be used to study magnetic anisotropies in materials. Two different techniques are discussed

  1. Muon spin relaxation in random spin systems

    International Nuclear Information System (INIS)

    Toshimitsu Yamazaki

    1981-01-01

    The longitudinal relaxation function Gsub(z)(t) of the positive muon can reflect dynamical characters of local field in a unique way even when the correlation time is longer than the Larmor period of local field. This method has been applied to studies of spin dynamics in spin glass systems, revealing sharp but continuous temperature dependence of the correlation time. Its principle and applications are reviewed. (author)

  2. Heisenberg spin glass experiments and the chiral ordering scenario

    International Nuclear Information System (INIS)

    Campbell, Ian A.; Petit, Dorothee C.M.C.

    2010-01-01

    An overview is given of experimental data on Heisenberg spin glass materials so as to make detailed comparisons with numerical results on model Heisenberg spin glasses, with particular reference to the chiral driven ordering transition scenario due to Kawamura and collaborators. On weak anisotropy systems, experiments show critical exponents which are very similar to those estimated numerically for the model Heisenberg chiral ordering transition but which are quite different from those at Ising spin glass transitions. Again on weak anisotropy Heisenberg spin glasses, experimental torque data show well defined in-field transverse ordering transitions up to strong applied fields, in contrast to Ising spin glasses where fields destroy ordering. When samples with stronger anisotropies are studied, critical and in-field behavior tend progressively towards the Ising limit. It can be concluded that the essential physics of laboratory Heisenberg spin glasses mirrors that of model Heisenberg spin glasses, where chiral ordering has been demonstrated numerically. (author)

  3. Similarity Measure of Graphs

    Directory of Open Access Journals (Sweden)

    Amine Labriji

    2017-07-01

    Full Text Available The topic of identifying the similarity of graphs was considered as highly recommended research field in the Web semantic, artificial intelligence, the shape recognition and information research. One of the fundamental problems of graph databases is finding similar graphs to a graph query. Existing approaches dealing with this problem are usually based on the nodes and arcs of the two graphs, regardless of parental semantic links. For instance, a common connection is not identified as being part of the similarity of two graphs in cases like two graphs without common concepts, the measure of similarity based on the union of two graphs, or the one based on the notion of maximum common sub-graph (SCM, or the distance of edition of graphs. This leads to an inadequate situation in the context of information research. To overcome this problem, we suggest a new measure of similarity between graphs, based on the similarity measure of Wu and Palmer. We have shown that this new measure satisfies the properties of a measure of similarities and we applied this new measure on examples. The results show that our measure provides a run time with a gain of time compared to existing approaches. In addition, we compared the relevance of the similarity values obtained, it appears that this new graphs measure is advantageous and  offers a contribution to solving the problem mentioned above.

  4. New Similarity Functions

    DEFF Research Database (Denmark)

    Yazdani, Hossein; Ortiz-Arroyo, Daniel; Kwasnicka, Halina

    2016-01-01

    In data science, there are important parameters that affect the accuracy of the algorithms used. Some of these parameters are: the type of data objects, the membership assignments, and distance or similarity functions. This paper discusses similarity functions as fundamental elements in membership...

  5. Similarity after Goodman

    NARCIS (Netherlands)

    Decock, L.B.; Douven, I.

    2011-01-01

    In a famous critique, Goodman dismissed similarity as a slippery and both philosophically and scientifically useless notion. We revisit his critique in the light of important recent work on similarity in psychology and cognitive science. Specifically, we use Tversky's influential set-theoretic

  6. Judgments of brand similarity

    NARCIS (Netherlands)

    Bijmolt, THA; Wedel, M; Pieters, RGM; DeSarbo, WS

    This paper provides empirical insight into the way consumers make pairwise similarity judgments between brands, and how familiarity with the brands, serial position of the pair in a sequence, and the presentation format affect these judgments. Within the similarity judgment process both the

  7. Textural Characteristics Of Seven Different Yams Dioscorea Species Grown And Consumed In Ghana

    Directory of Open Access Journals (Sweden)

    Delali Polycarp

    2017-02-01

    Full Text Available Texture is one of the most important indexes of quality in food products. It encompasses the structural and mechanical properties of a food and its sensory perception in the hand and in the mouth. This study was designed to evaluate the textural properties of the most cultivated and consumed yam Dioscorea varieties in Ghana in order to assess their potential alternative food and industrial processing applications. Matured yam varieties were obtained from the Roots and Tuber Conservatory Division of the Council for Scientific and Industrial Research-Plant Genetic Resources Research Institute Bunso Ghana. Textural profile of the cooked yam cultivars was established using texture analyser TA-XT2i Stable Microsystem Godalming England with built-in Texture Expert Exceed software. Cluster observation and principal component analyses were used to characterize the varieties based on similarities and differences in properties. The study showed that signiamp64257cant variations existed p0.05 in the textural properties of different yam varieties. Cooked samples of D. esculenta had the least hardness and chewiness 5.05 N and 0.22 respectively and will be suitable for food applications that require mashing while D. praehensalis had highest values for hardness and chewiness 49.9 N and 4.36. There were no significant differences p0.05 in adhesiveness of the yam varieties examined. D. rotundata D. alata and D. bulbifera varieties had tolerable textural properties appropriate for efficient industrial and food process applications. This information may be helpful in breeding and varietal improvement programmes for selecting varieties with similar textural properties for further study.

  8. The susceptibilities in the spin-S Ising model

    International Nuclear Information System (INIS)

    Ainane, A.; Saber, M.

    1995-08-01

    The susceptibilities of the spin-S Ising model are evaluated using the effective field theory introduced by Tucker et al. for studying general spin-S Ising model. The susceptibilities are studied for all spin values from S = 1/2 to S = 5/2. (author). 12 refs, 4 figs

  9. Relating microstructure, sensory and instrumental texture of processed oat

    Directory of Open Access Journals (Sweden)

    M. SALMENKALLIO-MARTTILA

    2008-12-01

    Full Text Available This study is a part of a larger project aiming to produce new, healthy, and tasty food ingredients from oat. Germination and different heating processes can be used to improve the texture and flavour of cereals. In this study effects of germination and wet and dry heating on the microstructure, instrumental structure and sensory properties of two oat varieties were assessed. The microstructure of native, germinated, autoclaved and extruded grains of the hulled cv. Veli and hull-less cv. Lisbeth was examined by light microscopy, the texture was measured by determining the milling energy and hardness of the grains and sensory characteristics were evaluated with descriptive sensory profile analysis. In cv. Veli the cells of the starchy endosperm were smaller than in cv. Lisbeth and ß-glucan was concentrated in the subaleurone layer. In cv. Lisbeth ß-glucan was evenly distributed in the starchy endosperm. The grains of cv. Lisbeth were more extensively modified in the germination process than the grains of cv. Veli, otherwise the effects of processing on the grains of the two cultivars were similar. Germination caused cell wall degradation, autoclaving and extrusion cooking caused starch gelatinization. Autoclaving resulted in the hardest perceived texture in oat. Gelatinization of starch appeared to contribute more to the hardness of oat groats than the cell wall structure. Of the instrumental methods used in this study the milling energy measurement appeared to be the most useful method for the analysis of the effects of processing on grain structure.;

  10. SMAPVEX12 Soil Texture Map V001

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set consists of soil texture classification data derived from field surveys as part of the Soil Moisture Active Passive Validation Experiment 2012...

  11. Neutron diffraction texture analysis for industrial applications

    International Nuclear Information System (INIS)

    Brokmeier, H.G.

    1994-01-01

    Considering the high transmission of neutron radiation, neutron diffraction is an efficient tool for the analysis of various material parameters of bulk material in a non-destructive way. Industrial application of texture analysis by X-ray diffraction is well established, whereas neutron diffraction applications are seldom. Thus a brief description explains the main differences between X-ray and neutron diffraction regarding texture measurements such as the investigation of coarse-grained materials, of large sample volumes and of multi-phase materials. The investigation of average textures of large sample volumes allows directly a correlation to material properties (e.g. Young's modulus, electric conductivity, plastic deformability, strength), which were determined on a workpiece. Examples will be given to show some applications of neutron diffraction texture analysis for technological interests. (orig.)

  12. Evolution of solidification texture during additive manufacturing

    Science.gov (United States)

    Wei, H. L.; Mazumder, J.; DebRoy, T.

    2015-01-01

    Striking differences in the solidification textures of a nickel based alloy owing to changes in laser scanning pattern during additive manufacturing are examined based on theory and experimental data. Understanding and controlling texture are important because it affects mechanical and chemical properties. Solidification texture depends on the local heat flow directions and competitive grain growth in one of the six preferred growth directions in face centered cubic alloys. Therefore, the heat flow directions are examined for various laser beam scanning patterns based on numerical modeling of heat transfer and fluid flow in three dimensions. Here we show that numerical modeling can not only provide a deeper understanding of the solidification growth patterns during the additive manufacturing, it also serves as a basis for customizing solidification textures which are important for properties and performance of components. PMID:26553246

  13. The semantic similarity ensemble

    Directory of Open Access Journals (Sweden)

    Andrea Ballatore

    2013-12-01

    Full Text Available Computational measures of semantic similarity between geographic terms provide valuable support across geographic information retrieval, data mining, and information integration. To date, a wide variety of approaches to geo-semantic similarity have been devised. A judgment of similarity is not intrinsically right or wrong, but obtains a certain degree of cognitive plausibility, depending on how closely it mimics human behavior. Thus selecting the most appropriate measure for a specific task is a significant challenge. To address this issue, we make an analogy between computational similarity measures and soliciting domain expert opinions, which incorporate a subjective set of beliefs, perceptions, hypotheses, and epistemic biases. Following this analogy, we define the semantic similarity ensemble (SSE as a composition of different similarity measures, acting as a panel of experts having to reach a decision on the semantic similarity of a set of geographic terms. The approach is evaluated in comparison to human judgments, and results indicate that an SSE performs better than the average of its parts. Although the best member tends to outperform the ensemble, all ensembles outperform the average performance of each ensemble's member. Hence, in contexts where the best measure is unknown, the ensemble provides a more cognitively plausible approach.

  14. Higher spin gauge theories

    CERN Document Server

    Henneaux, Marc; Vasiliev, Mikhail A

    2017-01-01

    Symmetries play a fundamental role in physics. Non-Abelian gauge symmetries are the symmetries behind theories for massless spin-1 particles, while the reparametrization symmetry is behind Einstein's gravity theory for massless spin-2 particles. In supersymmetric theories these particles can be connected also to massless fermionic particles. Does Nature stop at spin-2 or can there also be massless higher spin theories. In the past strong indications have been given that such theories do not exist. However, in recent times ways to evade those constraints have been found and higher spin gauge theories have been constructed. With the advent of the AdS/CFT duality correspondence even stronger indications have been given that higher spin gauge theories play an important role in fundamental physics. All these issues were discussed at an international workshop in Singapore in November 2015 where the leading scientists in the field participated. This volume presents an up-to-date, detailed overview of the theories i...

  15. Spin caloritronics in graphene

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Angsula; Frota, H. O. [Department of Physics, Federal University of Amazonas, Av. Rodrigo Octavio 3000-Japiim, 69077-000 Manaus, AM (Brazil)

    2015-06-14

    Spin caloritronics, the combination of spintronics with thermoelectrics, exploiting both the intrinsic spin of the electron and its associated magnetic moment in addition to its fundamental electronic charge and temperature, is an emerging technology mainly in the development of low-power-consumption technology. In this work, we study the thermoelectric properties of a Rashba dot attached to two single layer/bilayer graphene sheets as leads. The temperature difference on the two graphene leads induces a spin current, which depends on the temperature and chemical potential. We demonstrate that the Rashba dot behaves as a spin filter for selected values of the chemical potential and is able to filter electrons by their spin orientation. The spin thermopower has also been studied where the effects of the chemical potential, temperature, and also the Rashba term have been observed.

  16. Spin caloritronics in graphene

    Science.gov (United States)

    Frota, H. O.; Ghosh, Angsula

    2014-08-01

    Spin caloritronics, the combination of spintronics with thermoelectrics, based on spin and heat transport has attracted a great attention mainly in the development of low-power-consumption technology. In this work we study the thermoelectric properties of a quantum dot attached to two single layer graphene sheets as leads. The temperature difference on the two graphene leads induces a spin current which depends on the temperature and chemical potential. We demonstrate that the quantum dot behaves as a spin filter for selected values of the chemical potential and is able to filter electrons by their spin orientation. The spin thermopower has also been studied where the effects of the chemical potential, temperature and also the Coulomb repulsion due to the double occupancy of an energy level have been observed.

  17. A parametric texture model based on deep convolutional features closely matches texture appearance for humans.

    Science.gov (United States)

    Wallis, Thomas S A; Funke, Christina M; Ecker, Alexander S; Gatys, Leon A; Wichmann, Felix A; Bethge, Matthias

    2017-10-01

    Our visual environment is full of texture-"stuff" like cloth, bark, or gravel as distinct from "things" like dresses, trees, or paths-and humans are adept at perceiving subtle variations in material properties. To investigate image features important for texture perception, we psychophysically compare a recent parametric model of texture appearance (convolutional neural network [CNN] model) that uses the features encoded by a deep CNN (VGG-19) with two other models: the venerable Portilla and Simoncelli model and an extension of the CNN model in which the power spectrum is additionally matched. Observers discriminated model-generated textures from original natural textures in a spatial three-alternative oddity paradigm under two viewing conditions: when test patches were briefly presented to the near-periphery ("parafoveal") and when observers were able to make eye movements to all three patches ("inspection"). Under parafoveal viewing, observers were unable to discriminate 10 of 12 original images from CNN model images, and remarkably, the simpler Portilla and Simoncelli model performed slightly better than the CNN model (11 textures). Under foveal inspection, matching CNN features captured appearance substantially better than the Portilla and Simoncelli model (nine compared to four textures), and including the power spectrum improved appearance matching for two of the three remaining textures. None of the models we test here could produce indiscriminable images for one of the 12 textures under the inspection condition. While deep CNN (VGG-19) features can often be used to synthesize textures that humans cannot discriminate from natural textures, there is currently no uniformly best model for all textures and viewing conditions.

  18. Viable textures for the fermion sector

    International Nuclear Information System (INIS)

    Hernández, A E Cárcamo; Varzielas, I de Medeiros

    2015-01-01

    We consider a modification of the Fukuyama–Nishiura texture and compare it to the precision quark flavour data, finding that it fits the data very well but at the cost of accidental cancelations between parameters. We then propose different viable textures for quarks, where only the Cabibbo mixing arises from the down sector, and extend to the charged leptons while constructing a complementary neutrino structure that leads to viable lepton masses and mixing. (paper)

  19. Spin and Maximal Acceleration

    Directory of Open Access Journals (Sweden)

    Giorgio Papini

    2017-12-01

    Full Text Available We study the spin current tensor of a Dirac particle at accelerations close to the upper limit introduced by Caianiello. Continual interchange between particle spin and angular momentum is possible only when the acceleration is time-dependent. This represents a stringent limit on the effect that maximal acceleration may have on spin physics in astrophysical applications. We also investigate some dynamical consequences of maximal acceleration.

  20. Spin Hall effect devices

    Czech Academy of Sciences Publication Activity Database

    Jungwirth, Tomáš; Wunderlich, Joerg; Olejník, Kamil

    2012-01-01

    Roč. 11, č. 5 (2012), s. 382-390 ISSN 1476-1122 EU Projects: European Commission(XE) 268066 - 0MSPIN; European Commission(XE) 215368 - SemiSpinNet Grant - others:AV ČR(CZ) AP0801 Program:Akademická prémie - Praemium Academiae Institutional research plan: CEZ:AV0Z10100521 Keywords : spin Hall effect * spintronics * spin transistor Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 35.749, year: 2012

  1. Spin coating apparatus

    Science.gov (United States)

    Torczynski, John R.

    2000-01-01

    A spin coating apparatus requires less cleanroom air flow than prior spin coating apparatus to minimize cleanroom contamination. A shaped exhaust duct from the spin coater maintains process quality while requiring reduced cleanroom air flow. The exhaust duct can decrease in cross section as it extends from the wafer, minimizing eddy formation. The exhaust duct can conform to entrainment streamlines to minimize eddy formation and reduce interprocess contamination at minimal cleanroom air flow rates.

  2. Similarity or difference?

    DEFF Research Database (Denmark)

    Villadsen, Anders Ryom

    2013-01-01

    While the organizational structures and strategies of public organizations have attracted substantial research attention among public management scholars, little research has explored how these organizational core dimensions are interconnected and influenced by pressures for similarity. In this p......While the organizational structures and strategies of public organizations have attracted substantial research attention among public management scholars, little research has explored how these organizational core dimensions are interconnected and influenced by pressures for similarity....... In this paper I address this topic by exploring the relation between expenditure strategy isomorphism and structure isomorphism in Danish municipalities. Different literatures suggest that organizations exist in concurrent pressures for being similar to and different from other organizations in their field...... of action. It is theorized that to meet this challenge organizations may substitute increased similarity on one core dimension for increased idiosyncrasy on another, but only after a certain level of isomorphism is reached. Results of quantitative analyses support this theory and show that an inverse U...

  3. Combining fine texture and coarse color features for color texture classification

    Science.gov (United States)

    Wang, Junmin; Fan, Yangyu; Li, Ning

    2017-11-01

    Color texture classification plays an important role in computer vision applications because texture and color are two fundamental visual features. To classify the color texture via extracting discriminative color texture features in real time, we present an approach of combining the fine texture and coarse color features for color texture classification. First, the input image is transformed from RGB to HSV color space to separate texture and color information. Second, the scale-selective completed local binary count (CLBC) algorithm is introduced to extract the fine texture feature from the V component in HSV color space. Third, both H and S components are quantized at an optimal coarse level. Furthermore, the joint histogram of H and S components is calculated, which is considered as the coarse color feature. Finally, the fine texture and coarse color features are combined as the final descriptor and the nearest subspace classifier is used for classification. Experimental results on CUReT, KTH-TIPS, and New-BarkTex databases demonstrate that the proposed method achieves state-of-the-art classification performance. Moreover, the proposed method is fast enough for real-time applications.

  4. Texture memory and strain-texture mapping in a NiTi shape memory alloy

    International Nuclear Information System (INIS)

    Ye, B.; Majumdar, B. S.; Dutta, I.

    2007-01-01

    The authors report on the near-reversible strain hysteresis during thermal cycling of a polycrystalline NiTi shape memory alloy at a constant stress that is below the yield strength of the martensite. In situ neutron diffraction experiments are used to demonstrate that the strain hysteresis occurs due to a texture memory effect, where the martensite develops a texture when it is cooled under load from the austenite phase and is thereafter ''remembered.'' Further, the authors quantitatively relate the texture to the strain by developing a calculated strain-texture map or pole figure for the martensite phase, and indicate its applicability in other martensitic transformations

  5. Fast Image Texture Classification Using Decision Trees

    Science.gov (United States)

    Thompson, David R.

    2011-01-01

    Texture analysis would permit improved autonomous, onboard science data interpretation for adaptive navigation, sampling, and downlink decisions. These analyses would assist with terrain analysis and instrument placement in both macroscopic and microscopic image data products. Unfortunately, most state-of-the-art texture analysis demands computationally expensive convolutions of filters involving many floating-point operations. This makes them infeasible for radiation- hardened computers and spaceflight hardware. A new method approximates traditional texture classification of each image pixel with a fast decision-tree classifier. The classifier uses image features derived from simple filtering operations involving integer arithmetic. The texture analysis method is therefore amenable to implementation on FPGA (field-programmable gate array) hardware. Image features based on the "integral image" transform produce descriptive and efficient texture descriptors. Training the decision tree on a set of training data yields a classification scheme that produces reasonable approximations of optimal "texton" analysis at a fraction of the computational cost. A decision-tree learning algorithm employing the traditional k-means criterion of inter-cluster variance is used to learn tree structure from training data. The result is an efficient and accurate summary of surface morphology in images. This work is an evolutionary advance that unites several previous algorithms (k-means clustering, integral images, decision trees) and applies them to a new problem domain (morphology analysis for autonomous science during remote exploration). Advantages include order-of-magnitude improvements in runtime, feasibility for FPGA hardware, and significant improvements in texture classification accuracy.

  6. Texture and Elastic Anisotropy of Mantle Olivine

    Science.gov (United States)

    Nikitin, A. N.; Ivankina, T. I.; Bourilitchev, D. E.; Klima, K.; Locajicek, T.; Pros, Z.

    Eight olivine rock samples from different European regions were collected for neu- tron texture analyses and for P-wave velocity measurements by means of ultrasonic sounding at various confining pressures. The orientation distribution functions (ODFs) of olivine were determined and pole figures of the main crystallographic planes were calculated. The spatial P-wave velocity distributions were determined at confining pressures from 0.1 to 400 MPa and modelled from the olivine textures. In dependence upon the type of rock (xenolith or dunite) different behavior of both the P-wave veloc- ity distributions and the anisotropy coefficients with various confining pressures was observed. In order to explain the interdependence of elastic anisotropy and hydrostatic pressure, a model for polycrystalline olivine rocks was suggested, which considers the influence of the crystallographic and the mechanical textures on the elastic behaviour of the polycrystal. Since the olivine texture depends upon the active slip systems and the deformation temperature, neutron texture analyses enable us to estimate depth and thermodynamical conditions during texture formation.

  7. A controllable spin prism

    International Nuclear Information System (INIS)

    Hakioglu, T

    2009-01-01

    Based on Khodas et al (2004 Phys. Rev. Lett. 92 086602), we propose a device acting like a controllable prism for an incident spin. The device is a large quantum well where Rashba and Dresselhaus spin-orbit interactions are present and controlled by the plunger gate potential, the electric field and the barrier height. A totally destructive interference can be manipulated externally between the Rashba and Dresselhaus couplings. The spin-dependent transmission/reflection amplitudes are calculated as the control parameters are changed. The device operates as a spin prism/converter/filter in different regimes and may stimulate research in promising directions in spintronics in analogy with linear optics.

  8. Quantum spin Hall phases

    International Nuclear Information System (INIS)

    Murakami, Shuichi

    2009-01-01

    We review our recent theoretical works on the quantum spin Hall effect. First we compare edge states in various 2D systems, and see whether they are robust or fragile against perturbations. Through the comparisons we see the robust nature of edge states in 2D quantum spin Hall phases. We see how it is protected by the Z 2 topological number, and reveal the nature of the Z 2 topological number by studying the phase transition between the quantum spin Hall and insulator phases. We also review our theoretical proposal of the ultrathin bismuth film as a candidate to the 2D quantum spin Hall system. (author)

  9. PREFACE: Spin Electronics

    Science.gov (United States)

    Dieny, B.; Sousa, R.; Prejbeanu, L.

    2007-04-01

    Conventional electronics has in the past ignored the spin on the electron, however things began to change in 1988 with the discovery of giant magnetoresistance in metallic thin film stacks which led to the development of a new research area, so called spin-electronics. In the last 10 years, spin-electronics has achieved a number of breakthroughs from the point of view of both basic science and application. Materials research has led to several major discoveries: very large tunnel magnetoresistance effects in tunnel junctions with crystalline barriers due to a new spin-filtering mechanism associated with the spin-dependent symmetry of the electron wave functions new magnetic tunnelling barriers leading to spin-dependent tunnelling barrier heights and acting as spin-filters magnetic semiconductors with increasingly high ordering temperature. New phenomena have been predicted and observed: the possibility of acting on the magnetization of a magnetic nanostructure with a spin-polarized current. This effect, due to a transfer of angular momentum between the spin polarized conduction electrons and the local magnetization, can be viewed as the reciprocal of giant or tunnel magnetoresistance. It can be used to switch the magnetization of a magnetic nanostructure or to generate steady magnetic excitations in the system. the possibility of generating and manipulating spin current without charge current by creating non-equilibrium local accumulation of spin up or spin down electrons. The range of applications of spin electronics materials and phenomena is expanding: the first devices based on giant magnetoresistance were the magnetoresistive read-heads for computer disk drives. These heads, introduced in 1998 with current-in plane spin-valves, have evolved towards low resistance tunnel magnetoresistice heads in 2005. Besides magnetic recording technology, these very sensitive magnetoresistive sensors are finding applications in other areas, in particular in biology. magnetic

  10. Local Noncollinear Spin Analysis.

    Science.gov (United States)

    Abate, Bayileyegn A; Joshi, Rajendra P; Peralta, Juan E

    2017-12-12

    In this work, we generalize the local spin analysis of Clark and Davidson [J. Chem. Phys. 2001 115 (16), 7382] for the partitioning of the expectation value of the molecular spin square operator, ⟨Ŝ 2 ⟩, into atomic contributions, ⟨Ŝ A ·Ŝ B ⟩, to the noncollinear spin case in the framework of density functional theory (DFT). We derive the working equations, and we show applications to the analysis of the noncollinear spin solutions of typical spin-frustrated systems and to the calculation of magnetic exchange couplings. In the former case, we employ the triangular H 3 He 3 test molecule and a Mn 3 complex to show that the local spin analysis provides additional information that complements the standard one-particle spin population analysis. For the calculation of magnetic exchange couplings, J AB , we employ the local spin partitioning to extract ⟨Ŝ A ·Ŝ B ⟩ as a function of the interatomic spin orientation given by the angle θ. This, combined with the dependence of the electronic energy with θ, provides a methodology to extract J AB from DFT calculations that, in contrast to conventional energy differences based methods, does not require the use of ad hoc S A and S B values.

  11. Spin glasses (II)

    International Nuclear Information System (INIS)

    Fischer, K.H.

    1985-01-01

    Experimental results of spin glass studies are reviewed and related to existing theories. Investigations of spin glasses are concentrated on atomic structure, metallurgical treatment, and high-temperature susceptibility of alloys, on magnetic properties at low temperature and near the freezing temperature, on anisotropy behaviour measured by ESR, NMR and torque, on specific heat, Moessbauer effect, neutron scattering and muon-spin depolarization experiments, ultrasound and transport properties. Some new theories of spin glasses are discussed which have been developed since Part I appeared

  12. Realistic Free-Spins Features Increase Preference for Slot Machines.

    Science.gov (United States)

    Taylor, Lorance F; Macaskill, Anne C; Hunt, Maree J

    2017-06-01

    Despite increasing research into how the structural characteristics of slot machines influence gambling behaviour there have been no experimental investigations into the effect of free-spins bonus features-a structural characteristic that is commonly central to the design of slot machines. This series of three experiments investigated the free-spins feature using slot machine simulations to determine whether participants allocate more wagers to a machine with free spins, and, which components of free-spins features drive this preference. In each experiment, participants were exposed to two computer-simulated slot machines-one with a free-spins feature or similar bonus feature and one without. Participants then completed a testing phase where they could freely switch between the two machines. In Experiment 1, participants did not prefer the machine with a simple free-spins feature. In Experiment 2 the free-spins feature incorporated additional elements such as sounds, animations, and an increased win frequency; participants preferred to gamble on this machine. The Experiment 3 "bonus feature" machine resembled the free spins machine in Experiment 2 except spins were not free; participants showed a clear preference for this machine also. These findings indicate that (1) free-spins features have a major influence over machine choice and (2) the "freeness" of the free-spins bonus features is not an important driver of preference, contrary to self-report and interview research with gamblers.

  13. Noise in tunneling spin current across coupled quantum spin chains

    OpenAIRE

    Aftergood, Joshua; Takei, So

    2017-01-01

    We theoretically study the spin current and its dc noise generated between two spin-1/2 spin chains weakly coupled at a single site in the presence of an over-population of spin excitations and a temperature elevation in one subsystem relative to the other, and compare the corresponding transport quantities across two weakly coupled magnetic insulators hosting magnons. In the spin chain scenario, we find that applying a temperature bias exclusively leads to a vanishing spin current and a conc...

  14. Texture transition in experimentally deformed quartzite

    Science.gov (United States)

    Kilian, Rüdiger; Heilbronner, Renée

    2017-04-01

    Quartz crystallographic preferred orientations (textures), most commonly presented in the form of pole figures, are often used to infer deformation processes or conditions - despite the fact that we still do not understand fully how the different types of texture are generated. Here, we re-analyse experimentally deformed Black Hills Quartzite using EBSD maps. Samples were deformed in general shear in the dislocation creep regimes 1 to 3 at temperatures ranging from 875 to 915°C, constant shear strain rates of 1e-5/s (Heilbronner & Tullis, 2006), and resulting flow stresses of (600 MPa ≥ Tau ≥ 100 MPa). Already at low strain, a strong alignment of in the shear plane and of {10-11} with the maximum principal stress direction is observed. [0001] pole figures of recrystallized grains in regime 1 exhibit a peripheral maximum, roughly perpendicular to the shear plane while in regime 3 two elongated maxima are formed very close to the kinematic y-direction. Regime 2 shows a mixture of these two texture types. In regime 1, dynamic recrystallization is dominated by bulging recrystallization (nucleation of new grains), and in regime 3 by subgrain rotation recrystallization. In regime 2, again a mixture of regime 1 and 3 can be observed. Texture strength increases with the amount of crystal plastic deformation and is generally the lowest for the texture type with peripheral [0001]. During crystal plastic deformation [0001] rotate towards the kinematic y-direction. The coexistence and transition from one to the other texture type is suggested to result from two different texture-forming processes. The first process is thought to be crystal plasticity by glide on various slip systems and associated rotation of the crystal lattice, with the attractor of [0001] close to - but not exactly parallel to - the kinematic y-direction. The second process is suggested to be the growth of oriented grains during bulging recrystallization and associated (fracturing and) grain boundary

  15. Effect of spin rotation coupling on spin transport

    International Nuclear Information System (INIS)

    Chowdhury, Debashree; Basu, B.

    2013-01-01

    We have studied the spin rotation coupling (SRC) as an ingredient to explain different spin-related issues. This special kind of coupling can play the role of a Dresselhaus like coupling in certain conditions. Consequently, one can control the spin splitting, induced by the Dresselhaus like term, which is unusual in a semiconductor heterostructure. Within this framework, we also study the renormalization of the spin-dependent electric field and spin current due to the k → ⋅p → perturbation, by taking into account the interband mixing in the rotating system. In this paper we predict the enhancement of the spin-dependent electric field resulting from the renormalized spin rotation coupling. The renormalization factor of the spin electric field is different from that of the SRC or Zeeman coupling. The effect of renormalized SRC on spin current and Berry curvature is also studied. Interestingly, in the presence of this SRC-induced SOC it is possible to describe spin splitting as well as spin galvanic effect in semiconductors. -- Highlights: •Studied effect of spin rotation coupling on the spin electric field, spin current and Berry curvature. •In the k → ⋅p → framework we study the renormalization of spin electric field and spin current. •For an inertial system we have discussed the spin splitting. •Expression for the Berry phase in the inertial system is discussed. •The inertial spin galvanic effect is studied

  16. Texture profile analyses in tench (Tinca tinca L., 1758 from extensive and intensive culture

    Directory of Open Access Journals (Sweden)

    František Vácha

    2013-01-01

    Full Text Available The aim of the study was to evaluate the differences in texture profile of tench flesh. Texture profile analyses in tench, two years old, (Tinca tinca L. was investigated using instrumental texture profile method, focused on hardness, springiness, cohesiveness, gumminess and chewiness performed with Texture Analyser TA.XTPlus. One group of fish was raised extensively in natural earth pond conditions; the other group was intensively cultured in a recirculation system, feeding on a commercial diet for 7 months. Twelve fish (6 females and 6 males from each group were used for analyses. Flesh of male tench in both groups was harder, more gummy and chewy, compared to female. Springiness was lower in tench male from intensive culture and cohesiveness lower in females from both groups. The result of texture analysis in the extensive culture group was 16.01 N for hardness and 0.72, 0.66, 10.73 and 7.69 for springiness, cohesiveness, gumminess and chewiness, respectively. In the intensive culture group it was 15.16 N for hardness and 0.59, 0.52, 8.06 and 4.96 for springiness, cohesiveness, gumminess and chewiness, respectively. The results proved that the flesh of fish raised extensively is harder, springier, more cohesive and more gummy, and thus more appealing to consumers. This is the first similar study of texture profile of tench.

  17. Predication of coke strength from textural analysis of stamp charged coke supported by coal petrography

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, R.; Dash, P.S.; Chakraborty, D.; Banerjee, P.K.; Kumar, D. [Tata Steel, Jamshedpur (India)

    2005-07-01

    Materials science tells us that defects or flaws in a solid material control the mechanical behaviour of that material. Similarly, in a coke, its strength is associated with the microstructure and texture. Optical microscopy is the most appropriate method for measuring these features. Attempts were made to correlate different types of textures with the strength of stamp charged coke at Tata Steel. The studies revealed that anisotropic carbon is less reactive to carbon dioxide compared to isotropic carbon. There may be two reasons for this: a lower surface area of the carbon available for reaction; the intrinsic reactivity may be lower for molecules which constitute anisotropic carbon. The strength after reaction depends on its anisotropic texture - the smaller size mosaic texture contributes to higher post strength. There are very few reports about use of micro textural analysis to predict cold strength of coke. Test results show that there exists an influence of isotropic carbon on M{sub 10} index. With an increase in isotropic texture, the M{sub 10} index deteriorates. The performance of coke in blast furnaces may be improved by improving room temperature and high temperature strength of coke by selecting coal with higher vitrinite distribution in the present blend through the stamp charging route. 18 refs., 12 figs., 3 tabs.

  18. The effects of texture and strain on the r-value of heavy gauge tantalum plate

    International Nuclear Information System (INIS)

    Michaluk, C.; Bingert, J.; Choi, C.S.

    1994-01-01

    Previous work by other researchers suggests that the r-value measured from thick-gauge tantalum plate do not correspond to the predicted r-values calculated from ODF coefficients. To understand this behavior, bulk texture analysis using neutron diffraction techniques was conducted on annealed samples of Ta and Ta-2.5W plate: the pure tantalum exhibited a primary {111} type texture whereas the alloy contained a cube texture. For the pure tantalum, the r-values calculated from the texture of as-annealed and the deformed specimens were similar and correlated well with measured data. The r-value of the Ta-2.5W exhibited a greater amount of strain-sensitivity, such that the calculated r-values based on the initial texture did not represent those calculated or measured after tensile deformation. The strain sensitivity of r-values in Ta and Ta-2.5W plates is shown to relate to the generation of a left angle anti 110 right angle fiber texture during deformation. (orig.)

  19. The effects of texture and strain on the r-value of heavy gauge tantalum plate

    Energy Technology Data Exchange (ETDEWEB)

    Michaluk, C. (Cabot Performance Materials, Boyertown, PA (United States)); Bingert, J. (Los Alamos National Lab., NM (United States)); Choi, C.S. (U.S. Army, ARDEC, Gaithersburg, MD (United States))

    1994-01-01

    Previous work by other researchers suggests that the r-value measured from thick-gauge tantalum plate do not correspond to the predicted r-values calculated from ODF coefficients. To understand this behavior, bulk texture analysis using neutron diffraction techniques was conducted on annealed samples of Ta and Ta-2.5W plate: the pure tantalum exhibited a primary [l brace]111[r brace] type texture whereas the alloy contained a cube texture. For the pure tantalum, the r-values calculated from the texture of as-annealed and the deformed specimens were similar and correlated well with measured data. The r-value of the Ta-2.5W exhibited a greater amount of strain-sensitivity, such that the calculated r-values based on the initial texture did not represent those calculated or measured after tensile deformation. The strain sensitivity of r-values in Ta and Ta-2.5W plates is shown to relate to the generation of a left angle anti 110 right angle fiber texture during deformation. (orig.)

  20. The effects of texture and strain on the r-value of heavy gauge tantalum plate

    Energy Technology Data Exchange (ETDEWEB)

    Michaluk, C. [Cabot Performance Materials, Boyertown, PA (United States); Bingert, J. [Los Alamos National Lab., NM (United States); Choi, C.S. [US Army, Gaithersburg, MD (United States). ARDEC

    1993-10-01

    Previous work by other researches suggest that the r-values measured from thick-gauge tantalum plate do not correspond to the predicted r-values calculated from ODF coefficients. To understand this behavior, bulk texture analysis using neutron diffraction techniques was conducted on annealed samples of Ta and Ta-2.5W plate: the pure tantalum exhibited a primary {l_brace}111{r_brace} type texture whereas the alloy contained a cube texture. For the pure tantalum, the r-values calculated from the texture of as-annealed and the deformed specimens were similar and correlated well with measured data. The r-value of the Ta-2.5W exhibited a greater degree of strain-sensitivity, such that the calculated r-values based on the initial texture did not represent those calculated or measured after tensile deformation. Strain sensitivity of r-values in Ta and Ta-2.5W plates is related to the generation of a <{bar 1}10> fiber texture during deformation.

  1. Spin labels. Applications in biology

    International Nuclear Information System (INIS)

    Frangopol, T.P.; Frangopol, M.; Ionescu, S.M.; Pop, I.V.; Benga, G.

    1980-11-01

    The main applications of spin labels in the study of biomembranes, enzymes, nucleic acids, in pharmacology, spin immunoassay are reviewed along with the fundamentals of the spin label method. 137 references. (author)

  2. Spin Switching via Quantum Dot Spin Valves

    Science.gov (United States)

    Gergs, N. M.; Bender, S. A.; Duine, R. A.; Schuricht, D.

    2018-01-01

    We develop a theory for spin transport and magnetization dynamics in a quantum dot spin valve, i.e., two magnetic reservoirs coupled to a quantum dot. Our theory is able to take into account effects of strong correlations. We demonstrate that, as a result of these strong correlations, the dot gate voltage enables control over the current-induced torques on the magnets and, in particular, enables voltage-controlled magnetic switching. The electrical resistance of the structure can be used to read out the magnetic state. Our model may be realized by a number of experimental systems, including magnetic scanning-tunneling microscope tips and artificial quantum dot systems.

  3. Texture development in Al-Mg alloys during high temperature annealing

    International Nuclear Information System (INIS)

    Saitou, T.; Inagaki, H.

    2001-01-01

    To clarify the effect of Mg content on annealing textures developed in Al-Mg alloys during high temperature annealing, Al-Mg alloys containing up to 9 wt.% Mg in supersaturated solid solution were cold rolled 95% and isothermally annealed at 450 C. Their textures were investigated with the orientation distribution function analysis. It was found that, in the recrystallization textures observed at complete recrystallization, addition of more than 1 wt.% Mg was sufficient to suppress the development of {100} left angle 001 right angle. With increasing Mg content, {100} left angle 001 right angle decreased remarkably, whereas {100} left angle 013 right angle and {103} left angle 321 right angle increased. Thus, {100} left angle 013 right angle and {103} left angle 321 right angle were found to be the main orientations of the recrystallization textures of Al-Mg alloys annealed at high temperatures. {100} left angle 013 right angle developed most remarkably at 4 wt.% Mg, while {103} left angle 321 right angle showed the maximum development at 7 wt.% Mg. During subsequent grain growth at 450 C, remarkable texture changes were observed only in the alloys containing Mg in the range between 2 and 4 wt.%. In these alloys, {100} left angle 013 right angle developed at the expense of {100} left angle 001 right angle at earlier stages of grain growth, whereas {103} left angle 321 right angle increased independently of these two orientations at later stages of grain growth. Reflecting these texture changes, grain growth occurred in these alloys discontinuously. Such a discontinuous grain growth with large texture changes is expected, if strong textures are already present before grain growth, and if recrystallized grains having similar orientations are distributed by forming large clusters before grain growth. (orig.)

  4. UAV Remote Sensing for Urban Vegetation Mapping Using Random Forest and Texture Analysis

    Directory of Open Access Journals (Sweden)

    Quanlong Feng

    2015-01-01

    Full Text Available Unmanned aerial vehicle (UAV remote sensing has great potential for vegetation mapping in complex urban landscapes due to the ultra-high resolution imagery acquired at low altitudes. Because of payload capacity restrictions, off-the-shelf digital cameras are widely used on medium and small sized UAVs. The limitation of low spectral resolution in digital cameras for vegetation mapping can be reduced by incorporating texture features and robust classifiers. Random Forest has been widely used in satellite remote sensing applications, but its usage in UAV image classification has not been well documented. The objectives of this paper were to propose a hybrid method using Random Forest and texture analysis to accurately differentiate land covers of urban vegetated areas, and analyze how classification accuracy changes with texture window size. Six least correlated second-order texture measures were calculated at nine different window sizes and added to original Red-Green-Blue (RGB images as ancillary data. A Random Forest classifier consisting of 200 decision trees was used for classification in the spectral-textural feature space. Results indicated the following: (1 Random Forest outperformed traditional Maximum Likelihood classifier and showed similar performance to object-based image analysis in urban vegetation classification; (2 the inclusion of texture features improved classification accuracy significantly; (3 classification accuracy followed an inverted U relationship with texture window size. The results demonstrate that UAV provides an efficient and ideal platform for urban vegetation mapping. The hybrid method proposed in this paper shows good performance in differentiating urban vegetation mapping. The drawbacks of off-the-shelf digital cameras can be reduced by adopting Random Forest and texture analysis at the same time.

  5. TEXTURAL, FLOW AND SENSORY PROPERTIES OF FIVE “FRUZELINA” WITH SOUR CHERRIES

    Directory of Open Access Journals (Sweden)

    Irena Bojdo Tomasiak

    2010-05-01

    Full Text Available Gel with sour cherries called “Fruzelina” is a new product in the Polish market widely used in food industry as a decorative element or filling for pastries, as an ingredient in fruit desserts, as an additive to ice creams, whipped cream and waffles. The cherry gels are the product prepared using different types of chemically modified starches. Starch is an additive used to ensure rich and short texture and high viscosity of “Fruzelina”. Food texture and viscosity may be measured by senses and instrumentally. Because of fact that sensory analysis is time consuming and very costly, it is easier and cheaper to determine food properties, especially their texture and flow behaviour by appropriate mechanical tests. The aim of this work was to study the rheological behavior of five cherry gels and evaluate the correlation between textural, flow and sensory properties of these gels measured instrumentally and by human senses. The back extrusion test has been found to be applicable to study the textural properties of cherry gels. There was high positive correlation between gel texture measured by senses and texture parameters measured in back extrusion test. Similar high correlation was identified for consistency coefficient K obtained in Ostwald de Waele model and gel texture assessed by sensory panel. It was found that values of sensory parameters such as taste and odour decreased as the rheological parameters increased. High negative correlations were observed in these cases. Therefore, instrumental measurements can be alternative for more expensive sensory methods. doi:10.5219/53

  6. Spin, mass, and symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Peskin, M.E. [Stanford Univ., CA (United States)

    1994-12-01

    When the strong interactions were a mystery, spin seemed to be just a complication on top of an already puzzling set of phenomena. But now that particle physicists have understood the strong, weak, and electromagnetic interactions, to be gauge theories, with matter built of quarks and leptons, it is recognized that the special properties of spin 1/2 and spin 1 particles have taken central role in the understanding of Nature. The lectures in this summer school will be devoted to the use of spin in unravelling detailed questions about the fundamental interactions. Thus, why not begin by posing a deeper question: Why is there spin? More precisely, why do the basic pointlike constituents of Nature carry intrinsic nonzero quanta of angular momentum? Though the authos has found no definite answer to this question, the pursuit of an answer has led through a wonderful tangle of speculations on the deep structure of Nature. Is spin constructed or is it fundamental? Is it the requirement of symmetry? In the furthest flights taken, it seems that space-time itself is too restrictive a notion, and that this must be generalized in order to gain a full appreciation of spin. In any case, there is no doubt that spin must play a central role in unlocking the mysteries of fundamental physics.

  7. Physics lab in spin

    CERN Multimedia

    Hawkes, N

    1999-01-01

    RAL is fostering commerical exploitation of its research and facilities in two main ways : spin-out companies exploit work done at the lab, spin-in companies work on site taking advantage of the facilities and the expertise available (1/2 page).

  8. More spinoff from spin

    International Nuclear Information System (INIS)

    Masaike, Akira

    1993-01-01

    Despite playing a major role in today's Standard Model, spin - the intrinsic angular momentum carried by particles - is sometimes dismissed as an inessential complication. However several major spin questions with important implications for the Standard Model remain unanswered, and recent results and new technological developments made the 10th International Symposium on High Energy Spin Physics, held in Nagoya, Japan, in November, highly topical. The symposium covered a wide range of physics, reflecting the diversity of spin effects, however four main themes were - the spin content of the nucleon, tests of symmetries and physics beyond standard models, intermediate energy physics, and spin technologies. Opening the meeting, T. Kinoshita reviewed the status of measurements of the anomalous magnetic moment (g-2) of the electron and the muon. The forthcoming experiment at Brookhaven (September 1991, page 23) will probe beyond the energy ranges open to existing electronpositron colliders. For example muon substructure will be opened up to 5 TeV and Ws to 2 TeV. R.L. Jaffe classified quark-parton distributions in terms of their spin dependence, pointing out their leftright attributes, and emphasized the importance of measuring transverse spin distributions through lepton pair production

  9. Spin Hall noise

    NARCIS (Netherlands)

    Kamra, A.; Witek, F.P.; Meyer, S.; Huebl, H.; Geprägs, S.; Gross, R.; Bauer, G.E.W.; Goennenwein, S.T.B.

    2014-01-01

    We measure the low-frequency thermal fluctuations of pure spin current in a platinum film deposited on yttrium iron garnet via the inverse spin Hall effect (ISHE)-mediated voltage noise as a function of the angle ? between the magnetization and the transport direction. The results are consistent

  10. Antiferromagnetic spin Seebeck effect.

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Stephen M.; Zhang, Wei; KC, Amit; Borisov, Pavel; Pearson, John E.; Jiang, J. Samuel; Lederman, David; Hoffmann, Axel; Bhattacharya, Anand

    2016-03-03

    We report on the observation of the spin Seebeck effect in antiferromagnetic MnF2. A device scale on-chip heater is deposited on a bilayer of MnF2 (110) (30nm)/Pt (4 nm) grown by molecular beam epitaxy on a MgF2(110) substrate. Using Pt as a spin detector layer, it is possible to measure the thermally generated spin current from MnF2 through the inverse spin Hall effect. The low temperature (2–80 K) and high magnetic field (up to 140 kOe) regime is explored. A clear spin-flop transition corresponding to the sudden rotation of antiferromagnetic spins out of the easy axis is observed in the spin Seebeck signal when large magnetic fields (>9T) are applied parallel to the easy axis of the MnF2 thin film. When the magnetic field is applied perpendicular to the easy axis, the spin-flop transition is absent, as expected.

  11. Spin, mass, and symmetry

    International Nuclear Information System (INIS)

    Peskin, M.E.

    1994-01-01

    When the strong interactions were a mystery, spin seemed to be just a complication on top of an already puzzling set of phenomena. But now that particle physicists have understood the strong, weak, and electromagnetic interactions, to be gauge theories, with matter built of quarks and leptons, it is recognized that the special properties of spin 1/2 and spin 1 particles have taken central role in the understanding of Nature. The lectures in this summer school will be devoted to the use of spin in unravelling detailed questions about the fundamental interactions. Thus, why not begin by posing a deeper question: Why is there spin? More precisely, why do the basic pointlike constituents of Nature carry intrinsic nonzero quanta of angular momentum? Though the authos has found no definite answer to this question, the pursuit of an answer has led through a wonderful tangle of speculations on the deep structure of Nature. Is spin constructed or is it fundamental? Is it the requirement of symmetry? In the furthest flights taken, it seems that space-time itself is too restrictive a notion, and that this must be generalized in order to gain a full appreciation of spin. In any case, there is no doubt that spin must play a central role in unlocking the mysteries of fundamental physics

  12. Incremental Similarity and Turbulence

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Hedevang, Emil; Schmiegel, Jürgen

    This paper discusses the mathematical representation of an empirically observed phenomenon, referred to as Incremental Similarity. We discuss this feature from the viewpoint of stochastic processes and present a variety of non-trivial examples, including those that are of relevance for turbulence...

  13. Spin Waves in Terbium

    DEFF Research Database (Denmark)

    Jensen, J.; Houmann, Jens Christian Gylden; Bjerrum Møller, Hans

    1975-01-01

    with increasing temperatures implies that the two-ion coupling is effectively isotropic above ∼ 150 K. We present arguments for concluding that, among the mechanisms which may introduce anisotropic two-ion couplings in the rare-earth metals, the modification of the indirect exchange interaction by the spin......The energies of spin waves propagating in the c direction of Tb have been studied by inelastic neutron scattering, as a function of a magnetic field applied along the easy and hard directions in the basal plane, and as a function of temperature. From a general spin Hamiltonian, consistent...... with the symmetry, we deduce the dispersion relation for the spin waves in a basal-plane ferromagnet. This phenomenological spin-wave theory accounts for the observed behavior of the magnon energies in Tb. The two q⃗-dependent Bogoliubov components of the magnon energies are derived from the experimental results...

  14. Spin-memory loss due to spin-orbit coupling at ferromagnet/heavy-metal interfaces: Ab initio spin-density matrix approach

    Science.gov (United States)

    Dolui, Kapildeb; Nikolić, Branislav K.

    2017-12-01

    Spin-memory loss (SML) of electrons traversing ferromagnetic-metal/heavy-metal (FM/HM), FM/normal-metal (FM/NM), and HM/NM interfaces is a fundamental phenomenon that must be invoked to explain consistently large numbers of spintronic experiments. However, its strength extracted by fitting experimental data to phenomenological semiclassical theory, which replaces each interface by a fictitious bulk diffusive layer, is poorly understood from a microscopic quantum framework and/or materials properties. Here we describe an ensemble of flowing spin quantum states using spin-density matrix, so that SML is measured like any decoherence process by the decay of its off-diagonal elements or, equivalently, by the reduction of the magnitude of polarization vector. By combining this framework with density functional theory, we examine how all three components of the polarization vector change at Co/Ta, Co/Pt, Co/Cu, Pt/Cu, and Pt/Au interfaces embedded within Cu/FM/HM/Cu vertical heterostructures. In addition, we use ab initio Green's functions to compute spectral functions and spin textures over FM, HM, and NM monolayers around these interfaces which quantify interfacial spin-orbit coupling and explain the microscopic origin of SML in long-standing puzzles, such as why it is nonzero at the Co/Cu interface; why it is very large at the Pt/Cu interface; and why it occurs even in the absence of disorder, intermixing and magnons at the interface.

  15. Spin Hall magnetoresistance in antiferromagnet/normal metal bilayers

    KAUST Repository

    Manchon, Aurelien

    2017-01-01

    We investigate the emergence of spin Hall magnetoresistance in a magnetic bilayer composed of a normal metal adjacent to an antiferromagnet. Based on a recently derived drift diffusion equation, we show that the resistance of the bilayer depends on the relative angle between the direction transverse to the current flow and the Néel order parameter. While this effect presents striking similarities with the spin Hall magnetoresistance recently reported in ferromagnetic bilayers, its physical origin is attributed to the anisotropic spin relaxation of itinerant spins in the antiferromagnet.

  16. Strong electron correlation in photoionization of spin-orbit doublets

    International Nuclear Information System (INIS)

    Amusia, M.Ya.; Chernysheva, L.V.; Manson, S.T.; Msezane, A.M.; Radojevic, V.

    2002-01-01

    A new and explicitly many-body aspect of the 'leveraging' of the spin-orbit interaction is demonstrated, spin-orbit activated interchannel coupling, which can significantly alter the photoionization cross section of a spin-orbit doublet. As an example, it is demonstrated via a modified version of the spin-polarized random phase approximation with exchange, that a recently observed unexplained structure in the Xe 3d 5/2 photoionization cross section [A. Kivimaeki et al., Phys. Rev. A 63, 012716 (2000)] is entirely due to this effect. Similar features are predicted for Cs 3d 5/2 and Ba 3d 5/2

  17. In situ texture analysis under applied load

    International Nuclear Information System (INIS)

    Brokmeier, H.G.

    2005-01-01

    The in-situ measurement of a crystallographic texture is a special type of a non-destructive measurement, which need special equipments. Due to the high photon flux and the excellent brilliance high energetic synchrotron radiations are a fantastic tool particular in fast experimentation. Moreover, a high penetration power allows the investigation of standard tensile sample of the DIN-norm. A loading device with a power up to 20 kN was installed at the hard wiggler beamline BW5 (HASYLAB-DESY) to perform in-situ strain and in-situ texture analysis. Using 100keV X-rays one gets short wavelength so that a 2D image-plate detector offers a wide range of diffraction pattern within the first 10 degree in 2 theta. Thermal neutron is another radiation with a high penetration power, which is the standard method for global texture analysis of bulk samples. As an example rectangular extruded Mg- Az31 was investigated by an in-situ. tensile experiment. Samples with 0 degree, 45 degree and 90 degree to the extrusion direction were cut. In-situ strain studies show the lattice dependent strains perpendicular and parallel to the loading direction. Moreover, in hexagonal Mg-Az31 a strong influence of the initial texture on the tensile behavior can be explained by the combination of texture simulation with in-situ measurements. (author)

  18. Spin polarisation with electron Bessel beams

    Energy Technology Data Exchange (ETDEWEB)

    Schattschneider, P., E-mail: schattschneider@ifp.tuwien.ac.at [Institut für Festkörperphysik, Technische Universität Wien, A-1040 Wien (Austria); USTEM, Technische Universität Wien, A-1040 Wien (Austria); Grillo, V. [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); CNR-IMEM, Parco delle Scienze 37a, I-43100 Parma (Italy); Aubry, D. [Centrale Supelec, MSSMast CNRS 8579, F-92295 Châtenay-Malabry (France)

    2017-05-15

    The theoretical possibility to use an electron microscope as a spin polarizer is studied. It turns out that a Bessel beam passing a standard magnetic objective lens is intrinsically spin polarized when post-selected on-axis. In the limit of infinitely small detectors, the spin polarisation tends to 100 %. Increasing the detector size, the polarisation decreases rapidly, dropping below 10{sup −4} for standard settings of medium voltage microscopes. For extremely low voltages, the Figure of Merit increases by two orders of magnitude, approaching that of existing Mott detectors. Our findings may lead to new desings of spin filters, an attractive option in view of its inherent combination with the electron microscope, especially at low voltage. - Highlights: • TEM round magnetic lenses can act as spin polarizers when a Bessel beam is sent through. • This is found on theoretical grounds and demonstrated numerically for a few cases. • The effect is small, but can reach a Figure of Merit similar to existing Mott detectors. • This opens the possibility to construct nanometer-sized spin filters or detectors.

  19. Direct evidence of hidden local spin polarization in a centrosymmetric superconductor LaO0.55F0.45BiS2.

    Science.gov (United States)

    Wu, Shi-Long; Sumida, Kazuki; Miyamoto, Koji; Taguchi, Kazuaki; Yoshikawa, Tomoki; Kimura, Akio; Ueda, Yoshifumi; Arita, Masashi; Nagao, Masanori; Watauchi, Satoshi; Tanaka, Isao; Okuda, Taichi

    2017-12-04

    Conventional Rashba spin polarization is caused by the combination of strong spin-orbit interaction and spatial inversion asymmetry. However, Rashba-Dresselhaus-type spin-split states are predicted in the centrosymmetric LaOBiS 2 system by recent theory, which stem from the local inversion asymmetry of active BiS 2 layer. By performing high-resolution spin- and angle-resolved photoemission spectroscopy, we have investigated the electronic band structure and spin texture of superconductor LaO 0.55 F 0.45 BiS 2 . Here we present direct spectroscopic evidence for the local spin polarization of both the valence band and the conduction band. In particular, the coexistence of Rashba-like and Dresselhaus-like spin textures has been observed in the conduction band. The finding is of key importance for fabrication of proposed dual-gated spin-field effect transistor. Moreover, the spin-split band leads to a spin-momentum locking Fermi surface from which superconductivity emerges. Our demonstration not only expands the scope of spintronic materials but also enhances the understanding of spin-orbit interaction-related superconductivity.

  20. Similarity and denoising.

    Science.gov (United States)

    Vitányi, Paul M B

    2013-02-13

    We can discover the effective similarity among pairs of finite objects and denoise a finite object using the Kolmogorov complexity of these objects. The drawback is that the Kolmogorov complexity is not computable. If we approximate it, using a good real-world compressor, then it turns out that on natural data the processes give adequate results in practice. The methodology is parameter-free, alignment-free and works on individual data. We illustrate both methods with examples.

  1. Spin chain for quantum strings

    International Nuclear Information System (INIS)

    Beisert, N.

    2005-01-01

    We review and compare the integrable structures in N=4 gauge theory and string theory on AdS 5 x S 5 . Recently, Bethe ansaetze for gauge theory/weak coupling and string theory/strong coupling were proposed to describe scaling dimensions in the su(2) subsector. Here we investigate the Bethe equations for quantum string theory, naively extrapolated to weak coupling. Excitingly, we find a spin chain Hamiltonian similar, but not equal, to the gauge theory dilatation operator. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  2. Electrical detection of magnetization dynamics via spin rectification effects

    Energy Technology Data Exchange (ETDEWEB)

    Harder, Michael, E-mail: michael.harder@umanitoba.ca; Gui, Yongsheng, E-mail: ysgui@physics.umanitoba.ca; Hu, Can-Ming, E-mail: hu@physics.umanitoba.ca

    2016-11-23

    The purpose of this article is to review the current status of a frontier in dynamic spintronics and contemporary magnetism, in which much progress has been made in the past decade, based on the creation of a variety of micro and nanostructured devices that enable electrical detection of magnetization dynamics. The primary focus is on the physics of spin rectification effects, which are well suited for studying magnetization dynamics and spin transport in a variety of magnetic materials and spintronic devices. Intended to be intelligible to a broad audience, the paper begins with a pedagogical introduction, comparing the methods of electrical detection of charge and spin dynamics in semiconductors and magnetic materials respectively. After that it provides a comprehensive account of the theoretical study of both the angular dependence and line shape of electrically detected ferromagnetic resonance (FMR), which is summarized in a handbook format easy to be used for analysing experimental data. We then review and examine the similarity and differences of various spin rectification effects found in ferromagnetic films, magnetic bilayers and magnetic tunnel junctions, including a discussion of how to properly distinguish spin rectification from the spin pumping/inverse spin Hall effect generated voltage. After this we review the broad applications of rectification effects for studying spin waves, nonlinear dynamics, domain wall dynamics, spin current, and microwave imaging. We also discuss spin rectification in ferromagnetic semiconductors. The paper concludes with both historical and future perspectives, by summarizing and comparing three generations of FMR spectroscopy which have been developed for studying magnetization dynamics.

  3. Texture and deformation mechanism of yttrium

    International Nuclear Information System (INIS)

    Adamesku, R.A.; Grebenkin, S.V.; Stepanenko, A.V.

    1992-01-01

    X-ray pole figure analysis was applied to study texture and deformation mechanism in pure and commercial polycrystalline yttrium on cold working. It was found that in cast yttrium the texture manifected itself weakly enough both for pure and commercial metal. Analysis of the data obtained made it possible to assert that cold deformation of pure yttrium in the initial stage occurred mainly by slip the role of which decreased at strains higher than 36%. The texture of heavily deformed commercial yttrium contained two components, these were an 'ideal' basic orientation and an axial one with the angle of inclination about 20 deg. Twinning mechanism was revealed to be also possible in commercial yttrium

  4. Road surface texture and skid resistance

    Science.gov (United States)

    Do, Minh-Tan; Cerezo, Veronique

    2015-12-01

    This paper deals with the relationship between road surface texture and skid resistance. Mechanisms underlying the tire/wet road friction are first described. Definitions of road surface irregularities scales are given. The rest of the paper is then focused on the macrotexture and microtexture scales and their respective roles in what happens at the tire/road interface. Existing methods to measure and characterize the road surface texture are presented. On the one hand, problems encountered when using sensors developed for machined surfaces for the measurement of road surface profiles or cartographies are discussed. On the other hand, potential improvements when applying characterization methods developed for machined surfaces to road surfaces are highlighted. The paper presents finally modeling approaches to calculate friction forces from road surface texture. The generalized form of the models is presented from which terms related respectively to the macrotexture and the microtexture are identified. Approaches used to calculate these terms, integrating eventually other variables, are presented.

  5. Resonant Tunneling Spin Pump

    Science.gov (United States)

    Ting, David Z.

    2007-01-01

    The resonant tunneling spin pump is a proposed semiconductor device that would generate spin-polarized electron currents. The resonant tunneling spin pump would be a purely electrical device in the sense that it would not contain any magnetic material and would not rely on an applied magnetic field. Also, unlike prior sources of spin-polarized electron currents, the proposed device would not depend on a source of circularly polarized light. The proposed semiconductor electron-spin filters would exploit the Rashba effect, which can induce energy splitting in what would otherwise be degenerate quantum states, caused by a spin-orbit interaction in conjunction with a structural-inversion asymmetry in the presence of interfacial electric fields in a semiconductor heterostructure. The magnitude of the energy split is proportional to the electron wave number. Theoretical studies have suggested the possibility of devices in which electron energy states would be split by the Rashba effect and spin-polarized currents would be extracted by resonant quantum-mechanical tunneling.

  6. Nuclear spins in nanostructures

    International Nuclear Information System (INIS)

    Coish, W.A.; Baugh, J.

    2009-01-01

    We review recent theoretical and experimental advances toward understanding the effects of nuclear spins in confined nanostructures. These systems, which include quantum dots, defect centers, and molecular magnets, are particularly interesting for their importance in quantum information processing devices, which aim to coherently manipulate single electron spins with high precision. On one hand, interactions between confined electron spins and a nuclear-spin environment provide a decoherence source for the electron, and on the other, a strong effective magnetic field that can be used to execute local coherent rotations. A great deal of effort has been directed toward understanding the details of the relevant decoherence processes and to find new methods to manipulate the coupled electron-nuclear system. A sequence of spectacular new results have provided understanding of spin-bath decoherence, nuclear spin diffusion, and preparation of the nuclear state through dynamic polarization and more general manipulation of the nuclear-spin density matrix through ''state narrowing.'' These results demonstrate the richness of this physical system and promise many new mysteries for the future. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  7. Extruded snacks from whole wheat supplemented with textured soy flour: Effect on instrumental and sensory textural characteristics.

    Science.gov (United States)

    Rodríguez-Vidal, Arturo; Martínez-Flores, Héctor Eduardo; González Jasso, Eva; Velázquez de la Cruz, Gonzalo; Ramírez-Jiménez, Aurea K; Morales-Sánchez, Eduardo

    2017-06-01

    The quality of extruded snacks can be affected not only by processing conditions, but also by some factors like the concentration and type of ingredients incorporated in their formulation and the working conditions used. Although the process conditions have been established with measurable textural properties, sensory qualities have not been correlated with these responses in expanded extruded snacks made with added functional ingredients. Therefore, in this study the effect of adding textured soy flour (TSF) and whole wheat flour (WWF) to refined wheat flour in the production of extruded snacks and expanded with hot air was evaluated. A response surface design using two levels with five central points was applied to obtain the best combinations of functional ingredients added, holding the parameters of the extrusion process and moisture of treatments. Some texture characteristics and sensory analysis were used as response variables, such as, hardness, fracturability, toughness, crispness, granularity, and chewiness. Likewise, the rate of expansion was evaluated. The results showed that the level of substitution of WWF, especially levels of 15%, had a significant effect on the hardness perceived by the panelist during sensory evaluation. The TSF at concentrations of ≥15%, favored the fracturability and crispness of the samples. It was found that the best expansion index was with the combination of 5% TSF and 15% WWF. Although a correlation between instrumental and sensory tests carried out on the extruded snacks expanded was not found. The physical characteristics of the extruded snacks such as expansion, hardness, and density are important parameters in terms of consumer acceptability of the final product as well as their functional properties. In other words, the appearance and texture are two of the most important attributes that can be seen in snack foods. In particular, the texture can be measured by intrinsic tests: objective (instrumental) and subjective

  8. Spin drift and spin diffusion currents in semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Idrish Miah, M [Nanoscale Science and Technology Centre and School of Biomolecular and Physical Sciences, Griffith University, Nathan, Brisbane, QLD 4111 (Australia)], E-mail: m.miah@griffith.edu.au

    2008-09-15

    On the basis of a spin drift-diffusion model, we show how the spin current is composed and find that spin drift and spin diffusion contribute additively to the spin current, where the spin diffusion current decreases with electric field while the spin drift current increases, demonstrating that the extension of the spin diffusion length by a strong field does not result in a significant increase in spin current in semiconductors owing to the competing effect of the electric field on diffusion. We also find that there is a spin drift-diffusion crossover field for a process in which the drift and diffusion contribute equally to the spin current, which suggests a possible method of identifying whether the process for a given electric field is in the spin drift or spin diffusion regime. Spin drift-diffusion crossover fields for GaAs are calculated and are found to be quite small. We derive the relations between intrinsic spin diffusion length and the spin drift-diffusion crossover field of a semiconductor for different electron statistical regimes. The findings resulting from this investigation might be important for semiconductor spintronics.

  9. Spin drift and spin diffusion currents in semiconductors

    Directory of Open Access Journals (Sweden)

    M Idrish Miah

    2008-01-01

    Full Text Available On the basis of a spin drift-diffusion model, we show how the spin current is composed and find that spin drift and spin diffusion contribute additively to the spin current, where the spin diffusion current decreases with electric field while the spin drift current increases, demonstrating that the extension of the spin diffusion length by a strong field does not result in a significant increase in spin current in semiconductors owing to the competing effect of the electric field on diffusion. We also find that there is a spin drift-diffusion crossover field for a process in which the drift and diffusion contribute equally to the spin current, which suggests a possible method of identifying whether the process for a given electric field is in the spin drift or spin diffusion regime. Spin drift-diffusion crossover fields for GaAs are calculated and are found to be quite small. We derive the relations between intrinsic spin diffusion length and the spin drift-diffusion crossover field of a semiconductor for different electron statistical regimes. The findings resulting from this investigation might be important for semiconductor spintronics.

  10. Spin drift and spin diffusion currents in semiconductors

    International Nuclear Information System (INIS)

    Idrish Miah, M

    2008-01-01

    On the basis of a spin drift-diffusion model, we show how the spin current is composed and find that spin drift and spin diffusion contribute additively to the spin current, where the spin diffusion current decreases with electric field while the spin drift current increases, demonstrating that the extension of the spin diffusion length by a strong field does not result in a significant increase in spin current in semiconductors owing to the competing effect of the electric field on diffusion. We also find that there is a spin drift-diffusion crossover field for a process in which the drift and diffusion contribute equally to the spin current, which suggests a possible method of identifying whether the process for a given electric field is in the spin drift or spin diffusion regime. Spin drift-diffusion crossover fields for GaAs are calculated and are found to be quite small. We derive the relations between intrinsic spin diffusion length and the spin drift-diffusion crossover field of a semiconductor for different electron statistical regimes. The findings resulting from this investigation might be important for semiconductor spintronics.

  11. Higher spins and holography

    Science.gov (United States)

    Kraus, Per; Ross, Simon F.

    2013-05-01

    The principles of quantum mechanics and relativity impose rigid constraints on theories of massless particles with nonzero spin. Indeed, Yang-Mills theory and General Relativity are the unique solution in the case of spin-1 and spin-2. In asymptotically flat spacetime, there are fundamental obstacles to formulating fully consistent interacting theories of particles of spin greater than 2. However, indications are that such theories are just barely possible in asymptotically anti-de Sitter or de Sitter spacetimes, where the non-existence of an S-matrix provides an escape from the theorems restricting theories in Minkowski spacetime. These higher spin gravity theories are therefore of great intrinsic interest, since they, along with supergravity, provide the only known field theories generalizing the local invariance principles of Yang-Mills theory and General Relativity. While work on higher spin gravity goes back several decades, the subject has gained broader appeal in recent years due to its appearance in the AdS/CFT correspondence. In three and four spacetime dimensions, there exist duality proposals linking higher spin gravity theories to specific conformal field theories living in two and three dimensions respectively. The enlarged symmetry algebra of the conformal field theories renders them exactly soluble, which makes them excellent laboratories for understanding in detail the holographic mechanism behind AdS/CFT duality. Steady progress is also being made on better understanding the space of possible higher spin gravity theories and their physical content. This work includes classifying the possible field multiplets and their interactions, constructing exact solutions of the nonlinear field equations, and relating higher spin theories to string theory. A full understanding of these theories will involve coming to grips with the novel symmetry principles that enlarge those of General Relativity and Yang-Mills theory, and one can hope that this will provide

  12. Magnetic resonance imaging texture analysis classification of primary breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Waugh, S.A.; Lerski, R.A. [Ninewells Hospital and Medical School, Department of Medical Physics, Dundee (United Kingdom); Purdie, C.A.; Jordan, L.B. [Ninewells Hospital and Medical School, Department of Pathology, Dundee (United Kingdom); Vinnicombe, S. [University of Dundee, Division of Imaging and Technology, Ninewells Hospital and Medical School, Dundee (United Kingdom); Martin, P. [Ninewells Hospital and Medical School, Department of Clinical Radiology, Dundee (United Kingdom); Thompson, A.M. [University of Texas MD Anderson Cancer Center, Department of Surgical Oncology, Houston, TX (United States)

    2016-02-15

    Patient-tailored treatments for breast cancer are based on histological and immunohistochemical (IHC) subtypes. Magnetic Resonance Imaging (MRI) texture analysis (TA) may be useful in non-invasive lesion subtype classification. Women with newly diagnosed primary breast cancer underwent pre-treatment dynamic contrast-enhanced breast MRI. TA was performed using co-occurrence matrix (COM) features, by creating a model on retrospective training data, then prospectively applying to a test set. Analyses were blinded to breast pathology. Subtype classifications were performed using a cross-validated k-nearest-neighbour (k = 3) technique, with accuracy relative to pathology assessed and receiver operator curve (AUROC) calculated. Mann-Whitney U and Kruskal-Wallis tests were used to assess raw entropy feature values. Histological subtype classifications were similar across training (n = 148 cancers) and test sets (n = 73 lesions) using all COM features (training: 75 %, AUROC = 0.816; test: 72.5 %, AUROC = 0.823). Entropy features were significantly different between lobular and ductal cancers (p < 0.001; Mann-Whitney U). IHC classifications using COM features were also similar for training and test data (training: 57.2 %, AUROC = 0.754; test: 57.0 %, AUROC = 0.750). Hormone receptor positive and negative cancers demonstrated significantly different entropy features. Entropy features alone were unable to create a robust classification model. Textural differences on contrast-enhanced MR images may reflect underlying lesion subtypes, which merits testing against treatment response. (orig.)

  13. More Similar Than Different

    DEFF Research Database (Denmark)

    Pedersen, Mogens Jin

    2018-01-01

    What role do employee features play into the success of different personnel management practices for serving high performance? Using data from a randomized survey experiment among 5,982 individuals of all ages, this article examines how gender conditions the compliance effects of different...... incentive treatments—each relating to the basic content of distinct types of personnel management practices. The findings show that males and females are more similar than different in terms of the incentive treatments’ effects: Significant average effects are found for three out of five incentive...

  14. A Noise Robust Statistical Texture Model

    DEFF Research Database (Denmark)

    Hilger, Klaus Baggesen; Stegmann, Mikkel Bille; Larsen, Rasmus

    2002-01-01

    This paper presents a novel approach to the problem of obtaining a low dimensional representation of texture (pixel intensity) variation present in a training set after alignment using a Generalised Procrustes analysis.We extend the conventional analysis of training textures in the Active...... Appearance Models segmentation framework. This is accomplished by augmenting the model with an estimate of the covariance of the noise present in the training data. This results in a more compact model maximising the signal-to-noise ratio, thus favouring subspaces rich on signal, but low on noise....... Differences in the methods are illustrated on a set of left cardiac ventricles obtained using magnetic resonance imaging....

  15. Martensitic textures: Multiscale consequences of elastic compatibility

    International Nuclear Information System (INIS)

    Shenoy, S.R.; Lookman, T.; Saxena, A.; Bishop, A.R.

    2001-03-01

    We show that a free energy entirely in the order-parameter strain variable(s), rather than the displacement field, provides a unified understanding of martensitic textures. We use compatibility equations, linking the strain tensor components in the bulk and at interfaces, that induce anisotropic order-parameter strain interactions. These two long-range bulk/interface potentials, together with local compositional fluctuations, drive the formation of global elastic textures. Relaxational simulations show the spontaneous formation (and evolution under stress/temperature quenches) of equal width parallel twins, branched twins, and tweed, including characteristic scaling of twin width with twin length. (author)

  16. Biaxially textured articles formed by powder metallurgy

    Science.gov (United States)

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2003-07-29

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100} orientation texture; and further having a Curie temperature less than that of pure Ni.

  17. Biaxially textured articles formed by power metallurgy

    Science.gov (United States)

    Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

    2003-08-26

    A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100} orientation texture; and further having a Curie temperature less than that of pure Ni.

  18. CNN based texture synthesize with Semantic segment

    OpenAIRE

    Liang, Xianye; Zhuo, Bocheng; Li, Peijie; He, Liangju

    2016-01-01

    Deep learning algorithm display powerful ability in Computer Vision area, in recent year, the CNN has been applied to solve problems in the subarea of Image-generating, which has been widely applied in areas such as photo editing, image design, computer animation, real-time rendering for large scale of scenes and for visual effects in movies. However in the texture synthesize procedure. The state-of-art CNN can not capture the spatial location of texture in image, lead to significant distorti...

  19. Spin transfer torque with spin diffusion in magnetic tunnel junctions

    KAUST Repository

    Manchon, Aurelien

    2012-08-09

    Spin transport in magnetic tunnel junctions in the presence of spin diffusion is considered theoretically. Combining ballistic tunneling across the barrier and diffusive transport in the electrodes, we solve the spin dynamics equation in the metallic layers. We show that spin diffusion mixes the transverse spin current components and dramatically modifies the bias dependence of the effective spin transfer torque. This leads to a significant linear bias dependence of the out-of-plane torque, as well as a nonconventional thickness dependence of both spin torque components.

  20. Electron spin and nuclear spin manipulation in semiconductor nanosystems

    International Nuclear Information System (INIS)

    Hirayama, Yoshiro; Yusa, Go; Sasaki, Satoshi

    2006-01-01

    Manipulations of electron spin and nuclear spin have been studied in AlGaAs/GaAs semiconductor nanosystems. Non-local manipulation of electron spins has been realized by using the correlation effect between localized and mobile electron spins in a quantum dot- quantum wire coupled system. Interaction between electron and nuclear spins was exploited to achieve a coherent control of nuclear spins in a semiconductor point contact device. Using this device, we have demonstrated a fully coherent manipulation of any two states among the four spin levels of Ga and As nuclei. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Spins in chemistry

    CERN Document Server

    McWeeny, Roy

    2004-01-01

    Originally delivered as a series of lectures, this volume systematically traces the evolution of the ""spin"" concept from its role in quantum mechanics to its assimilation into the field of chemistry. Author Roy McWeeny presents an in-depth illustration of the deductive methods of quantum theory and their application to spins in chemistry, following the path from the earliest concepts to the sophisticated physical methods employed in the investigation of molecular structure and properties. Starting with the origin and development of the spin concept, the text advances to an examination of sp

  2. Frustrated spin systems

    CERN Document Server

    2013-01-01

    This book covers all principal aspects of currently investigated frustrated systems, from exactly solved frustrated models to real experimental frustrated systems, going through renormalization group treatment, Monte Carlo investigation of frustrated classical Ising and vector spin models, low-dimensional systems, spin ice and quantum spin glass. The reader can - within a single book - obtain a global view of the current research development in the field of frustrated systems.This new edition is updated with recent theoretical, numerical and experimental developments in the field of frustrated

  3. Spin Hall effect transistor

    Czech Academy of Sciences Publication Activity Database

    Wunderlich, Joerg; Park, B.G.; Irvine, A.C.; Zarbo, Liviu; Rozkotová, E.; Němec, P.; Novák, Vít; Sinova, Jairo; Jungwirth, Tomáš

    2010-01-01

    Roč. 330, č. 6012 (2010), s. 1801-1804 ISSN 0036-8075 R&D Projects: GA AV ČR KAN400100652; GA MŠk LC510 EU Projects: European Commission(XE) 215368 - SemiSpinNet Grant - others:AV ČR(CZ) AP0801 Program:Akademická prémie - Praemium Academiae Institutional research plan: CEZ:AV0Z10100521 Keywords : spin Hall effect * spintronics * spin transistor Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 31.364, year: 2010

  4. Spin tracking in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Luccio, A.U. [Brookhaven National Lab., Upton, NY (United States); Katayama, T. [Univ. of Tokyo (Japan); Wu, H. [Riken Inst., Tokyo (Japan)

    1997-07-01

    In the acceleration of polarized protons in RHIC many spin depolarizing resonances are encountered. Helical Siberian snakes will be used to overcome depolarizing effects. The behavior of polarization can be studied by numerical tracking in a model accelerator. That allows one to check the strength of the resonances, to study the effect of snakes, to find safe lattice tune regions, and finally to study the operation of special devices like spin flippers. In this paper the authors describe numerical spin tracking. Results show that, for the design corrected distorted orbit and the design beam emittance, the polarization of the beam will be preserved in the whole range of proton energies in RHIC.

  5. SPINning parallel systems software

    International Nuclear Information System (INIS)

    Matlin, O.S.; Lusk, E.; McCune, W.

    2002-01-01

    We describe our experiences in using Spin to verify parts of the Multi Purpose Daemon (MPD) parallel process management system. MPD is a distributed collection of processes connected by Unix network sockets. MPD is dynamic processes and connections among them are created and destroyed as MPD is initialized, runs user processes, recovers from faults, and terminates. This dynamic nature is easily expressible in the Spin/Promela framework but poses performance and scalability challenges. We present here the results of expressing some of the parallel algorithms of MPD and executing both simulation and verification runs with Spin

  6. Quantitative texture determination in pressure tube (Zr-2.5 Wt% Nb alloy) material as a function of cold work

    International Nuclear Information System (INIS)

    Dey, G.K.; Tewari, R.; Srivastava, D.; De, P.K.; Banerjee, S.; Kiran Kumar, M.; Samajdar, I.

    2003-06-01

    The texture studies on the pressure tube Zr-2.5 Nb alloy have mainly been confined to the determination of the basal pole distribution along certain direction or the inverse pole presentation in the material. This information though useful does not provide an insight into micro-textural development upon cold working. In the present study, complete bulk as well as micro texture development as a function of cold work has been obtained by determining orientation distribution function. In this work, two distinct starting microstructures of Zr-2.5 wt% Nb have been used -(a) single-phase α(hcp) martensitic structure and (b) two-phase, β(bcc) + α, Widmanstaetten structure. In the second case, the α phase was present in lamellar morphology and β stringers were sandwiched between these a lamella. In some instances single-phase α were present. However, both microstructures had similar starting crystallographic texture. Samples were deformed by unidirectional and cross rolling at room temperature. In the two-phase structure the changes in the bulk texture on cold rolling was found to be insignificant, while in the single-phase material noticeable textural changes were observed. Taylor type deformation texture models predicted textural changes in single-phase structure but failed to predict the observed lack of textural development in the two-phase material. Microtexture observations showed that a plates remained approximately single crystalline after cold rolling, while the β matrix underwent significant orientational changes. Based on microstructural and microtextural observations, a simple model is proposed in which the plastic flow is mainly confined to the β matrix within which the α plates are subjected to in-plane rigid body rotation. The model explains the observed lack of textural developments in the two-phase structure. (author)

  7. Spin squeezing and quantum correlations

    Indian Academy of Sciences (India)

    2 states. A coherent spin-s state. (CSS) θ φ can then be thought of as having no quantum correlations as the constituent. 2s elementary spins point in the same direction ˆn(θ φ) which is the mean spin direction. 2. State classification and squeezing. In order to discuss squeezing, we begin with the squeezing condition itself.

  8. Geometry of spin coherent states

    Science.gov (United States)

    Chryssomalakos, C.; Guzmán-González, E.; Serrano-Ensástiga, E.

    2018-04-01

    Spin states of maximal projection along some direction in space are called (spin) coherent, and are, in many respects, the ‘most classical’ available. For any spin s, the spin coherent states form a 2-sphere in the projective Hilbert space \

  9. Coupling nitrogen-vacancy centers to a dynamic ferromagnetic vortex for fast, nanoscale spin addressability and control

    Science.gov (United States)

    Berezovsky, Jesse

    As we begin to look at how spin qubits might be integrated into a scalable platform, a promising strategy is to engineer the magnetic environment of the spins using micron- or nanometer-scale ferromagnetic (FM) elements, for functionalities such as nanoscale addressability, spin-wave mediated coupling, or enhanced sensing. The promise of these FM/spin interactions brings with it the question of how the coherence properties of the spin will be affected by coupling to these complex mesoscopic systems. To explore the physics of individual spins coupled to a proximal, dynamic ferromagnetic structure, we have studied interactions between individual nitrogen-vacancy (NV) spins and a model FM system - a vortex magnetization state. The complex, yet controllable, spin texture of a FM vortex, formed in a thin disk or nanowire, allows one to study different regimes of interaction with a nearby confined spin. The vortex core produces a large static dipole-like fringe field. The vortex state also displays discrete dynamic modes ranging from several 100 MHz to GHz. By applying an in-plane magnetic field, the position of the vortex core relative to the NV spin can be controlled with nanometer-scale resolution, and time resolution of 10s of nanoseconds. As the vortex core is translated into proximity with an NV spin, the fringe field from the core generates a large position-dependent spin splitting, permitting nanoscale spin addressability. We also find that the dynamic interaction of the vortex, NV spin, and applied microwave field results in amplification of the Rabi transition rate by more than an order of magnitude. Finally, we explore how spin decoherence and relaxation mechanisms are enhanced as the vortex core approaches the NVs, with implications for proposed technology incorporating coherent spins and proximal FM elements. We acknowledge support from DOE, Award No. DE-SC008148.

  10. The brass-type texture and its deviation from the copper-type texture

    DEFF Research Database (Denmark)

    Leffers, Torben; Ray, R.K.

    2009-01-01

    development of significant texture components with {1 1 1} approximately parallel to the rolling plane. (4) The deformation pattern during the later stages of the development of the brass-type texture is normally dominated by shear banding. (5) Copper–manganese alloys with more than 5% manganese develop...... results from a preliminary attempt to introduce the composite pattern in a complex model. We also suggest that more advanced models (like n-site models) are applied to the shear banding stage. As to the fundamental physical process governing the fcc rolling texture transition we quote recent...

  11. Spin Hall effect and spin swapping in diffusive superconductors

    Science.gov (United States)

    Espedal, Camilla; Lange, Peter; Sadjina, Severin; Mal'shukov, A. G.; Brataas, Arne

    2017-02-01

    We consider the spin-orbit-induced spin Hall effect and spin swapping in diffusive superconductors. By employing the nonequilibrium Keldysh Green's function technique in the quasiclassical approximation, we derive coupled transport equations for the spectral spin and particle distributions and for the energy density in the elastic scattering regime. We compute four contributions to the spin Hall conductivity, namely, skew scattering, side jump, anomalous velocity, and the Yafet contribution. The reduced density of states in the superconductor causes a renormalization of the spin Hall angle. We demonstrate that all four of these contributions to the spin Hall conductivity are renormalized in the same way in the superconducting state. In its simplest manifestation, spin swapping transforms a primary spin current into a secondary spin current with swapped current and polarization directions. We find that the spin-swapping coefficient is not explicitly but only implicitly affected by the superconducting gap through the renormalized diffusion coefficients. We discuss experimental consequences for measurements of the (inverse) spin Hall effect and spin swapping in four-terminal geometries. In our geometry, below the superconducting transition temperature, the spin-swapping signal is increased an order of magnitude while changes in the (inverse) spin Hall signal are moderate.

  12. Microscopic studies of nonlocal spin dynamics and spin transport (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Adur, Rohan; Du, Chunhui; Cardellino, Jeremy; Scozzaro, Nicolas; Wolfe, Christopher S.; Wang, Hailong; Herman, Michael; Bhallamudi, Vidya P.; Pelekhov, Denis V.; Yang, Fengyuan; Hammel, P. Chris, E-mail: hammel@physics.osu.edu [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States)

    2015-05-07

    Understanding the behavior of spins coupling across interfaces in the study of spin current generation and transport is a fundamental challenge that is important for spintronics applications. The transfer of spin angular momentum from a ferromagnet into an adjacent normal material as a consequence of the precession of the magnetization of the ferromagnet is a process known as spin pumping. We find that, in certain circumstances, the insertion of an intervening normal metal can enhance spin pumping between an excited ferromagnetic magnetization and a normal metal layer as a consequence of improved spin conductance matching. We have studied this using inverse spin Hall effect and enhanced damping measurements. Scanned probe magnetic resonance techniques are a complementary tool in this context offering high resolution magnetic resonance imaging, localized spin excitation, and direct measurement of spin lifetimes or damping. Localized magnetic resonance studies of size-dependent spin dynamics in the absence of lithographic confinement in both ferromagnets and paramagnets reveal the close relationship between spin transport and spin lifetime at microscopic length scales. Finally, detection of ferromagnetic resonance of a ferromagnetic film using the photoluminescence of nitrogen vacancy spins in neighboring nanodiamonds demonstrates long-range spin transport between insulating materials, indicating the complexity and generality of spin transport in diverse, spatially separated, material systems.

  13. Carbon Dioxide Sealing Capacity: Textural or Compositional Controls?

    Energy Technology Data Exchange (ETDEWEB)

    Cranganu, Constantin; Soleymani, Hamidreza; Sadiqua, Soleymani; Watson, Kieva

    2013-11-30

    This research project is aiming to assess the carbon dioxide sealing capacity of most common seal-rocks, such as shales and non-fractured limestones, by analyzing the role of textural and compositional parameters of those rocks. We hypothesize that sealing capacity is controlled by textural and/or compositional pa-rameters of caprocks. In this research, we seek to evaluate the importance of textural and compositional parameters affecting the sealing capacity of caprocks. The conceptu-al framework involves two testable end-member hypotheses concerning the sealing ca-pacity of carbon dioxide reservoir caprocks. Better understanding of the elements controlling sealing quality will advance our knowledge regarding the sealing capacity of shales and carbonates. Due to relatively low permeability, shale and non-fractured carbonate units are considered relatively imper-meable formations which can retard reservoir fluid flow by forming high capillary pres-sure. Similarly, these unites can constitute reliable seals for carbon dioxide capture and sequestration purposes. This project is a part of the comprehensive project with the final aim of studying the caprock sealing properties and the relationship between microscopic and macroscopic characteristics of seal rocks in depleted gas fields of Oklahoma Pan-handle. Through this study we examined various seal rock characteristics to infer about their respective effects on sealing capacity in special case of replacing reservoir fluid with super critical carbon dioxide (scCO{sub 2}). To assess the effect of textural and compositional properties on scCO{sub 2} maximum reten-tion column height we collected 30 representative core samples in caprock formations in three counties (Cimarron, Texas, Beaver) in Oklahoma Panhandle. Core samples were collected from various seal formations (e.g., Cherokee, Keys, Morrowan) at different depths. We studied the compositional and textural properties of the core samples using several techniques

  14. RIS4E at Kilauea's December 1974 Flow: Lava Flow Texture LiDAR Signatures

    Science.gov (United States)

    Whelley, P.; Garry, W. B.; Scheidt, S. P.; Bleacher, J. E.; Hamilton, C.

    2015-12-01

    High-resolution point clouds and digital terrain models (DTMs) are used to investigate lava textures on the Big Island of Hawaii. Lava texture (e.g., ´áā and pāhoehoe) depends significantly on eruption conditions, and it is therefore instructive, if accurately determined. In places where field investigations are prohibitive (e.g., on other planets and remote regions of Earth) lava texture must be assessed from remote sensing data. A reliable method for doing so remains elusive. The December 1974 flow from Kilauea, in the Kau desert, presents an excellent field site to develop techniques for identifying lava texture. The eruption is young and the textures are well preserved. We present results comparing properties of lava textures observed in Terrestrial Laser Scanning (TLS) data. The authors collected the TLS data during May 2014 and June 2015 field seasons. Scans are a quantitative representation of what a geologist, or robotic system, sees "on the ground" and provides "ground truth" for airborne or orbital remote sensing analysis by enabling key parameters of lava morphology to be quantified. While individual scans have a heterogeneous point density, multiple scans are merged such that sub-cm lava textures can be quantified. Results indicate that TLS-derived surface roughness (i.e., de-trended RMS roughness) is useful for differentiating lava textures and assists volcanologic interpretations. As many lava types are quite rough, it is not simply roughness that is the most advantageous parameter for differentiating lava textures; rather co-occurrence patterns in surface roughness are used. Gradually forming textures (e.g., pāhoehoe) are elevated in statistics that measure smoothness (e.g., homogeneity) while lava with disrupted crusts (e.g., slabby and platy flow) have more random distributions of roughness (i.e., high entropy). A similar technique will be used to analyze high-resolution DTMs of martian lava flows using High Resolution Imaging Science

  15. Higher Spins & Strings

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    The conjectured relation between higher spin theories on anti de-Sitter (AdS) spaces and weakly coupled conformal field theories is reviewed. I shall then outline the evidence in favour of a concrete duality of this kind, relating a specific higher spin theory on AdS3 to a family of 2d minimal model CFTs. Finally, I shall explain how this relation fits into the framework of the familiar stringy AdS/CFT correspondence.

  16. Quantum spin quadrumer

    Science.gov (United States)

    Khatua, Subhankar; Shankar, R.; Ganesh, R.

    2018-02-01

    A fundamental motif in frustrated magnetism is the fully mutually coupled cluster of N spins, with each spin coupled to every other spin. Clusters with N =2 and 3 have been extensively studied as building blocks of square and triangular lattice antiferromagnets. In both cases, large-S semiclassical descriptions have been fruitfully constructed, providing insights into the physics of macroscopic magnetic systems. Here, we develop a semiclassical theory for the N =4 cluster. This problem has rich mathematical structure with a ground-state space that has nontrivial topology. We show that ground states are appropriately parametrized by a unit vector order parameter and a rotation matrix. Remarkably, in the low-energy description, the physics of the cluster reduces to that of an emergent free spin-S spin and a rigid rotor. This successfully explains the spectrum of the quadrumer and its associated degeneracies. However, this mapping does not hold in the vicinity of collinear ground states due to a subtle effect that arises from the nonmanifold nature of the ground-state space. We demonstrate this by an analysis of soft fluctuations, showing that collinear states have a larger number of soft modes. Nevertheless, as these singularities only occur on a subset of measure zero, the mapping to a spin and a rotor provides a good description of the quadrumer. We interpret thermodynamic properties of the quadrumer that are accessible in molecular magnets, in terms of the rotor and spin degrees of freedom. Our study paves the way for field theoretic descriptions of systems such as pyrochlore magnets.

  17. Spider Spinning for Dummies

    Science.gov (United States)

    Bird, Richard S.

    Spider spinning is a snappy name for the problem of listing the ideals of a totally acyclic poset in such a way that each ideal is computed from its predecessor in constant time. Such an algorithm is said to be loopless. Our aim in these lectures is to show how to calculate a loopless algorithm for spider spinning. The calculation makes use of the fundamental laws of functional programming and the real purpose of the exercise is to show these laws in action.

  18. Spin-zero mesons and current algebras

    International Nuclear Information System (INIS)

    Wellner, M.

    1977-01-01

    Large chiral algebras, using the f and d coefficients of SU(3) can be constructed with spin-1/2 baryons. Such algebras have been found useful in some previous investigations. This article examines under what conditions similar or identical current algebras may be realized with spin-0 mesons. A curious lack of analogy emerges between meson and baryon currents. Second-class currents, made of mesons, are required in some algebras. If meson and baryon currents are to satisfy the same extended SU(3) algebra, four meson nonets are needed, in terms of which we give an explicit construction for the currents

  19. Spin-Precession Organic Magnetic Sensor

    Science.gov (United States)

    2012-09-26

    with the voltage and we get a value of ~200 per tesla for the quantity [V -1 (dV/dB)], which roughly translates into a sensitivity of 14 nT/Hz 1/2...Ideally, the response should be similar to the spin- valve measurements—the resistance changes as the magnetization of each of the contacts flips as we...strips. Typical spin- valve measurements employ strip widths of ~10-20 nm. However, the smallest width achievable in our FIB process is 500 nm, and the

  20. Wetting transitions on textured hydrophilic surfaces.

    Science.gov (United States)

    Ishino, C; Okumura, K

    2008-04-01

    We consider the quasi-static energy of a drop on a textured hydrophilic surface, with taking the contact angle hysteresis (CAH) into account. We demonstrate how energy varies as the contact state changes from the Cassie state (in which air is trapped at the drop bottom) to the Wenzel state (in which liquid fills the texture at the drop bottom) assuming that the latter state nucleates from the center of the drop bottom. When the textured substrate is hydrophilic enough to allow spontaneous penetration of liquid film of the texture thickness, the present theory asserts that the drop develops into an experimentally observed state in which a drop looks like an egg fried without flipped over (sunny-side up) with a well-defined radius of "the egg yolk." Otherwise, the final contact state of the drop becomes like a Wenzel state, but with the contact circle smaller than the original Wenzel state due to the CAH. We provide simple analytical estimations for the yolk radius of the "sunny-side-up" state and for the final radius of the contact circle of the pseudo-Wenzel state.

  1. AN ILLUMINATION INVARIANT TEXTURE BASED FACE RECOGNITION

    Directory of Open Access Journals (Sweden)

    K. Meena

    2013-11-01

    Full Text Available Automatic face recognition remains an interesting but challenging computer vision open problem. Poor illumination is considered as one of the major issue, since illumination changes cause large variation in the facial features. To resolve this, illumination normalization preprocessing techniques are employed in this paper to enhance the face recognition rate. The methods such as Histogram Equalization (HE, Gamma Intensity Correction (GIC, Normalization chain and Modified Homomorphic Filtering (MHF are used for preprocessing. Owing to great success, the texture features are commonly used for face recognition. But these features are severely affected by lighting changes. Hence texture based models Local Binary Pattern (LBP, Local Derivative Pattern (LDP, Local Texture Pattern (LTP and Local Tetra Patterns (LTrPs are experimented under different lighting conditions. In this paper, illumination invariant face recognition technique is developed based on the fusion of illumination preprocessing with local texture descriptors. The performance has been evaluated using YALE B and CMU-PIE databases containing more than 1500 images. The results demonstrate that MHF based normalization gives significant improvement in recognition rate for the face images with large illumination conditions.

  2. Geometric Total Variation for Texture Deformation

    DEFF Research Database (Denmark)

    Bespalov, Dmitriy; Dahl, Anders Lindbjerg; Shokoufandeh, Ali

    2010-01-01

    In this work we propose a novel variational method that we intend to use for estimating non-rigid texture deformation. The method is able to capture variation in grayscale images with respect to the geometry of its features. Our experimental evaluations demonstrate that accounting for geometry of...

  3. Physicochemical and textural properties of kombucha fermented ...

    African Journals Online (AJOL)

    The possibility of kombucha application cultivated on two different tea types in combination with probiotics for milk fermentation at different temperatures, as well as the physicochemical and textural properties of manufactured fermented milk products were investigated. Combination of probiotic starter culture and kombucha ...

  4. Friction tensor concept for textured surfaces

    Indian Academy of Sciences (India)

    This paper proposes the concept of a friction tensor analogous to the heat conduc- tion tensor in anisotropic media. This implies that there exists two principal friction coefficients μ1,2 analogous to the principal conductivities k1,2. For symmetrically textured surfaces the principal directions are orthogonal with atleast one ...

  5. Combinatorial design of textured mechanical metamaterials.

    Science.gov (United States)

    Coulais, Corentin; Teomy, Eial; de Reus, Koen; Shokef, Yair; van Hecke, Martin

    2016-07-28

    The structural complexity of metamaterials is limitless, but, in practice, most designs comprise periodic architectures that lead to materials with spatially homogeneous features. More advanced applications in soft robotics, prosthetics and wearable technology involve spatially textured mechanical functionality, which requires aperiodic architectures. However, a naive implementation of such structural complexity invariably leads to geometrical frustration (whereby local constraints cannot be satisfied everywhere), which prevents coherent operation and impedes functionality. Here we introduce a combinatorial strategy for the design of aperiodic, yet frustration-free, mechanical metamaterials that exhibit spatially textured functionalities. We implement this strategy using cubic building blocks-voxels-that deform anisotropically, a local stacking rule that allows cooperative shape changes by guaranteeing that deformed building blocks fit together as in a three-dimensional jigsaw puzzle, and three-dimensional printing. These aperiodic metamaterials exhibit long-range holographic order, whereby the two-dimensional pixelated surface texture dictates the three-dimensional interior voxel arrangement. They also act as programmable shape-shifters, morphing into spatially complex, but predictable and designable, shapes when uniaxially compressed. Finally, their mechanical response to compression by a textured surface reveals their ability to perform sensing and pattern analysis. Combinatorial design thus opens up a new avenue towards mechanical metamaterials with unusual order and machine-like functionalities.

  6. Multidimensional Texture Analysis for Unsupervised Pattern Classification

    OpenAIRE

    Hammouche, K.; Postaire, J.-G.

    2008-01-01

    After a series of adaptations of classical image processing tools to cluster analysis such as thresholding, edge detection, relaxation, Markov field models and mathematical morphology, this chapter shows how texture analysis concepts can be introduced in the field of pattern classification. A general-purpose clustering procedure has been presented,

  7. Rheological and textural properties of cosmetic emulsions

    Czech Academy of Sciences Publication Activity Database

    Morávková, Tereza; Štern, Petr

    2011-01-01

    Roč. 21, č. 3 (2011), č. článku 35200. ISSN 1430-6395 Institutional research plan: CEZ:AV0Z20600510 Keywords : cosmetic emulsions * rheology * texture * sensory analysis * psychorheology Subject RIV: BK - Fluid Dynamics Impact factor: 1.000, year: 2011

  8. On Texture and Geometry in Image Analysis

    DEFF Research Database (Denmark)

    Gustafsson, David Karl John

    2009-01-01

    -out of the captured scene will also change. At large viewing distances, the sky occupies a large region in the image and buildings, trees and lawns appear as uniformly colored regions. The following questions are addressed: How much of the visual appearance in terms of geometry and texture of an image can...

  9. THE CAUSAL TEXTURE OF TRADE UNION ENVIRONMENTS

    African Journals Online (AJOL)

    Admin

    This paper is an attempt to fill an important gap in the existing literature on trade unions by providing a more adequate theoretical formulation of trade union environments. The discussion suggests that unlike the environment of business and related organisations whose causal texture is understood in terms of uncertainty, ...

  10. Development of a texture averaged Reynolds equation

    NARCIS (Netherlands)

    Kraker, A. de; Ostayen, R.A.J. van; Rixen, D.J.

    2010-01-01

    The application of textured bearing surfaces results in a more complex lubricant flow pattern compared to smooth bearing surfaces. In order to capture the more complex flow pattern and possible inertia effects in the vicinity of the surface pockets, the NavierStokes equations should be used to model

  11. Mathematical modelling of dropwise condensation on textured ...

    Indian Academy of Sciences (India)

    The minimum drop radius is insensitive to surface texturing and does not provide controllability at larger length and timescales. A closer examination of droplet distribution over the substrate reveals that small drops are locations of high heat transfer rates, which diminishes with increasing drop radius. The largest drop ...

  12. On the origin of recrystallization textures

    Indian Academy of Sciences (India)

    In the ON model, it has been argued that a higher frequency of the special orientation (grains) than random occur, thus accounting for the texture. In the OG model, it has been argued that the specially oriented grains have a high mobility boundary and thus can migrate faster and grow to a larger size as compared to random ...

  13. Textural characterization of chars using fractal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mahamud, Manuel; Lopez, Oscar [Department of Chemical and Environmental Engineering, Faculty of Chemistry, University of Oviedo, Campus de El Cristo, 33071 Oviedo (Spain); Pis, Jose Juan; Pajares, Jesus Alberto [Instituto Nacional del Carbon C.S.I.C., Apartado 73, 33080 Oviedo (Spain)

    2004-11-25

    The aim of this study is to explore the potential of fractal analysis in helping to understand the textural changes of materials during the manufacture of active carbons. Textural characterization of the chars is carried out in order to obtain a better understanding of the phenomena underlying char formation. The materials selected for study were a series of chars obtained from coals oxidized in air at various temperatures for different periods of time. The data from mercury porosimetry were analyzed using fractal models. The average fractal dimensions for the chars were calculated by using the methods proposed by Friesen and Mikula and that of Zhang and Li. Fractal profiles of the chars obtained by the method of Neimark were compared with the corresponding fractal profiles of the precursor coals. Pore development during carbonization depends-among other factors that are kept constant in this study-on the textural properties of the precursor coal, the devolatilization process and the plastic properties of coals. The evolution of the fractal characteristics of the chars is also studied. At the same time pore volume development is analyzed. These analyses help to clarify the role that various phenomena occurring during carbonization have on the textural properties of the chars.

  14. Some Numerical Characteristics of Image Texture

    Directory of Open Access Journals (Sweden)

    O. Samarina

    2012-05-01

    Full Text Available Texture classification is one of the basic images processing tasks. In this paper we present some numerical characteristics to the images analysis and processing. It can be used at the solving of images classification problems, their recognition, problems of remote sounding, biomedical images analysis, geological researches.

  15. Prague texture segmentation data generator and benchmark

    Czech Academy of Sciences Publication Activity Database

    Mikeš, Stanislav; Haindl, Michal

    2006-01-01

    Roč. 2006, č. 64 (2006), s. 67-68 ISSN 0926-4981 R&D Projects: GA MŠk(CZ) 1M0572; GA AV ČR(CZ) 1ET400750407; GA AV ČR IAA2075302 Institutional research plan: CEZ:AV0Z10750506 Keywords : image segmentation * texture * benchmark * web Subject RIV: BD - Theory of Information

  16. Study of the texture and stored energy of stainless steels by using neutron diffraction

    International Nuclear Information System (INIS)

    Shin, Eunjoo; Seong, Baek-Seok; Park, Soo Ho; Kim, Hark-Rho

    2006-01-01

    The texture of 400 series stainless steels was investigated by using neutron diffraction and the calculated R-values from the texture were compared with the experimental R-values. Cold rolled samples with different reduction rates were used to investigate the effect of the cold rolling reduction rate on the formability. Also, the stored energies of the cold rolled samples were relatively evaluated by using neutron diffraction. The R-value of the recrystallized samples revealed similar values after an 80% reduction, and the stored energy of the cold rolled samples presented the same results

  17. Healthy food compositions having the texture of gel or foam and comprising hydrolysed egg products

    OpenAIRE

    Sandoval Huertas, Mario; Miguel, Marta; Garcés Rimón, M.; López-Fandiño, Rosina

    2014-01-01

    [EN] The invention relates to healthy food compositions having the texture of gel or foam, as well as being rich in proteins, having anti-oxidant properties, being low in fat, free from lactose and casein, and being easy to chew. The compositions comprise a neutral-tasting egg hydrolysate as a basic ingredient. The compositions are provided as an alternative to sweet and savoury dishes that use dairy products as a base, given that the compositions have a similar flavour, appearance and textur...

  18. Evaluation of pavement skid resistance using high speed texture measurement

    Directory of Open Access Journals (Sweden)

    Jay N. Meegoda

    2015-12-01

    Full Text Available Skid resistance is an important parameter for highway designs, construction, management, maintenance and safety. The purpose of this manuscript is to propose the correlation between skid resistance, which is measured as skid resistance trailer, and mean profile depth (MPD or the macro surface texture, which is measured by vehicle mounted laser, so that highway agencies can predict the skid resistance of pavement without the use of expensive and time consuming skid resistance trailer, which also causes disruption of traffic in use. In this research skid numbers and MPD from 5 new asphalt pavements and 4 old asphalt pavements were collected using a locked wheel skid trailer and a vehicle mounted laser. Using the data collected, a correlation between the skid number (SN40R collected by locked wheel skid tester and the texture data or MPD collected by a vehicle mounted laser operating at highway speeds was developed. The proposed correlation for new pavements was positive for MPD values less than 0.75 mm to reach a peak SN40R value, then there was a negative correlation as the MPD increases until the MPD value was equal to 1.1 mm and beyond the MPD value of 1.1 mm to the maximum value of 1.4 mm, SN40R value remained almost constant. There were significant data scatter for the MPD value of 0.8 mm. To explain these results, water film thickness during the friction test was calculated and the critical MPD was defined. The effect of sealed water pool on the SN40R was discussed. The test result showed a similar trend for older asphalt pavements, but with lower SN40R values due to the polishing of pavement micro-texture by traffic. Hence, a reduction factor was proposed for older pavements based on cumulative traffic volume for the above correlation to predict the skid resistance of older pavements.

  19. Spin-engineered quantum dots

    OpenAIRE

    Fleurov, V.; Ivanov, V. A.; Peeters, F. M.; Vagner, I. D.

    2001-01-01

    Spatially nonhomogeneously spin polarized nuclei are proposed as a new mechanism to monitor electron states in a nanostructure, or as a means to createn and, if necessary, reshape such nanostructures in the course of the experiment. We found that a polarization of nulear spins may lift the spin polarization of the electron states in a nanostructure and, if sufficiently strong, leads to a polarization of the electron spins. Polarized nuclear spins may form an energy landscape capable of bindin...

  20. Theory of spin Hall effect

    OpenAIRE

    Chudnovsky, Eugene M.

    2007-01-01

    An extension of Drude model is proposed that accounts for spin and spin-orbit interaction of charge carriers. Spin currents appear due to combined action of the external electric field, crystal field and scattering of charge carriers. The expression for spin Hall conductivity is derived for metals and semiconductors that is independent of the scattering mechanism. In cubic metals, spin Hall conductivity $\\sigma_s$ and charge conductivity $\\sigma_c$ are related through $\\sigma_s = [2 \\pi \\hbar...

  1. Retrieval and Mapping of Soil Texture Based on Land Surface Diurnal Temperature Range Data from MODIS.

    Science.gov (United States)

    Wang, De-Cai; Zhang, Gan-Lin; Zhao, Ming-Song; Pan, Xian-Zhang; Zhao, Yu-Guo; Li, De-Cheng; Macmillan, Bob

    2015-01-01

    Numerous studies have investigated the direct retrieval of soil properties, including soil texture, using remotely sensed images. However, few have considered how soil properties influence dynamic changes in remote images or how soil processes affect the characteristics of the spectrum. This study investigated a new method for mapping regional soil texture based on the hypothesis that the rate of change of land surface temperature is related to soil texture, given the assumption of similar starting soil moisture conditions. The study area was a typical flat area in the Yangtze-Huai River Plain, East China. We used the widely available land surface temperature product of MODIS as the main data source. We analyzed the relationships between the content of different particle soil size fractions at the soil surface and land surface day temperature, night temperature and diurnal temperature range (DTR) during three selected time periods. These periods occurred after rainfalls and between the previous harvest and the subsequent autumn sowing in 2004, 2007 and 2008. Then, linear regression models were developed between the land surface DTR and sand (> 0.05 mm), clay (soil texture. The spatial distribution of soil texture from the studied area was mapped based on the model with the minimum RMSE. A validation dataset produced error estimates for the predicted maps of sand, clay and physical clay, expressed as RMSE of 10.69%, 4.57%, and 12.99%, respectively. The absolute error of the predictions is largely influenced by variations in land cover. Additionally, the maps produced by the models illustrate the natural spatial continuity of soil texture. This study demonstrates the potential for digitally mapping regional soil texture variations in flat areas using readily available MODIS data.

  2. Building damage assessment from PolSAR data using texture parameters of statistical model

    Science.gov (United States)

    Li, Linlin; Liu, Xiuguo; Chen, Qihao; Yang, Shuai

    2018-04-01

    Accurate building damage assessment is essential in providing decision support for disaster relief and reconstruction. Polarimetric synthetic aperture radar (PolSAR) has become one of the most effective means of building damage assessment, due to its all-day/all-weather ability and richer backscatter information of targets. However, intact buildings that are not parallel to the SAR flight pass (termed oriented buildings) and collapsed buildings share similar scattering mechanisms, both of which are dominated by volume scattering. This characteristic always leads to misjudgments between assessments of collapsed buildings and oriented buildings from PolSAR data. Because the collapsed buildings and the intact buildings (whether oriented or parallel buildings) have different textures, a novel building damage assessment method is proposed in this study to address this problem by introducing texture parameters of statistical models. First, the logarithms of the estimated texture parameters of different statistical models are taken as a new texture feature to describe the collapse of the buildings. Second, the collapsed buildings and intact buildings are distinguished using an appropriate threshold. Then, the building blocks are classified into three levels based on the building block collapse rate. Moreover, this paper also discusses the capability for performing damage assessment using texture parameters from different statistical models or using different estimators. The RADARSAT-2 and ALOS-1 PolSAR images are used to present and analyze the performance of the proposed method. The results show that using the texture parameters avoids the problem of confusing collapsed and oriented buildings and improves the assessment accuracy. The results assessed by using the K/G0 distribution texture parameters estimated based on the second moment obtain the highest extraction accuracies. For the RADARSAT-2 and ALOS-1 data, the overall accuracy (OA) for these three types of

  3. Retrieval and Mapping of Soil Texture Based on Land Surface Diurnal Temperature Range Data from MODIS

    Science.gov (United States)

    Wang, De-Cai; Zhang, Gan-Lin; Zhao, Ming-Song; Pan, Xian-Zhang; Zhao, Yu-Guo; Li, De-Cheng; Macmillan, Bob

    2015-01-01

    Numerous studies have investigated the direct retrieval of soil properties, including soil texture, using remotely sensed images. However, few have considered how soil properties influence dynamic changes in remote images or how soil processes affect the characteristics of the spectrum. This study investigated a new method for mapping regional soil texture based on the hypothesis that the rate of change of land surface temperature is related to soil texture, given the assumption of similar starting soil moisture conditions. The study area was a typical flat area in the Yangtze-Huai River Plain, East China. We used the widely available land surface temperature product of MODIS as the main data source. We analyzed the relationships between the content of different particle soil size fractions at the soil surface and land surface day temperature, night temperature and diurnal temperature range (DTR) during three selected time periods. These periods occurred after rainfalls and between the previous harvest and the subsequent autumn sowing in 2004, 2007 and 2008. Then, linear regression models were developed between the land surface DTR and sand (> 0.05 mm), clay (estimate soil texture. The spatial distribution of soil texture from the studied area was mapped based on the model with the minimum RMSE. A validation dataset produced error estimates for the predicted maps of sand, clay and physical clay, expressed as RMSE of 10.69%, 4.57%, and 12.99%, respectively. The absolute error of the predictions is largely influenced by variations in land cover. Additionally, the maps produced by the models illustrate the natural spatial continuity of soil texture. This study demonstrates the potential for digitally mapping regional soil texture variations in flat areas using readily available MODIS data. PMID:26090852

  4. Texture of semi-solids : sensory flavor-texture interactions for custard desserts

    NARCIS (Netherlands)

    Wijk, de R.A.; Rasing, F.; Wilkinson, C.L.

    2003-01-01

    Possible interactions between flavor and oral texture sensations were investigated for four flavorants, diacetyl, benzaldehyde, vanillin, and caffeine, added in two concentrations to model vanilla custard desserts. The flavorants affected viscosities and resulted in corresponding changes in

  5. Solvent-induced textural changes of as-synthesized mesoporous alumina, as reported by spin probe electron spin resonance spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Caragheorgheopol, A.; Caldararu, H.; Ionita, G.; Savonea, F.; Žilková, Naděžda; Zukal, Arnošt; Čejka, Jiří

    2005-01-01

    Roč. 21, č. 6 (2005), s. 2591-2597 ISSN 0743-7463 R&D Projects: GA ČR(CZ) GA104/02/0571; GA AV ČR(CZ) IAA4040411 Grant - others:NATO in the framework "Science for Peace" SfP -974 217 Institutional research plan: CEZ:AV0Z40400503 Keywords : molecular-sieves * formation mechanism * catalysis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.705, year: 2005

  6. Spin-Current and Spin-Splitting in Helicoidal Molecules Due to Spin-Orbit Coupling

    Science.gov (United States)

    Caetano, R. A.

    2016-03-01

    The use of organic materials in spintronic devices has been seriously considered after recent experimental works have shown unexpected spin-dependent electrical properties. The basis for the confection of any spintronic device is ability of selecting the appropriated spin polarization. In this direction, DNA has been pointed out as a potential candidate for spin selection due to the spin-orbit coupling originating from the electric field generated by accumulated electrical charges along the helix. Here, we demonstrate that spin-orbit coupling is the minimum ingredient necessary to promote a spatial spin separation and the generation of spin-current. We show that the up and down spin components have different velocities that give rise to a spin-current. By using a simple situation where spin-orbit coupling is present, we provide qualitative justifications to our results that clearly point to helicoidal molecules as serious candidates to integrate spintronic devices.

  7. Spin Torques in Systems with Spin Filtering and Spin Orbit Interaction

    KAUST Repository

    Ortiz Pauyac, Christian

    2016-06-19

    In the present thesis we introduce the reader to the field of spintronics and explore new phenomena, such as spin transfer torques, spin filtering, and three types of spin-orbit torques, Rashba, spin Hall, and spin swapping, which have emerged very recently and are promising candidates for a new generation of memory devices in computer technology. A general overview of these phenomena is presented in Chap. 1. In Chap. 2 we study spin transfer torques in tunnel junctions in the presence of spin filtering. In Chap. 3 we discuss the Rashba torque in ferromagnetic films, and in Chap. 4 we study spin Hall effect and spin swapping in ferromagnetic films, exploring the nature of spin-orbit torques based on these mechanisms. Conclusions and perspectives are summarized in Chap. 5.

  8. Effects of pavement surface texture on noise and frictional characteristics.

    Science.gov (United States)

    1987-02-01

    An experimental modification of the transverse groove : surface texture of a section of an urban interstate highway was : performed by the Iowa Department of Transportation. Transverse : groove texturing is a design feature required by the Federal : ...

  9. Electron spin-lattice relaxation in fractals

    International Nuclear Information System (INIS)

    Shrivastava, K.N.

    1986-08-01

    We have developed the theory of the spin-fracton interaction for paramagnetic ions in fractal structures. The interaction is exponentially damped by the self-similarity length of the fractal and by the range dimensionality d Φ . The relaxation time of the spin due to the absorption and emission of the fracton has been calculated for a general dimensionality called the Raman dimensionality d R , which for the fractons differs from the Hausdorff (fractal) dimensionality, D, as well as from the Euclidean dimensionality, d. The exponent of the energy level separation in the relaxation rate varies with d R d Φ /D. We have calculated the spin relaxation rate due to a new type of Raman process in which one fracton is absorbed to affect a spin transition from one electronic level to another and later another fracton is emitted along with a spin transition such that the difference in the energies of the two fractons is equal to the electronic energy level separation. The temperature and the dimensionality dependence of such a process has been found in several approximations. In one of the approximations where the van Vleck relaxation rate for a spin in a crystal is known to vary with temperature as T 9 , our calculated variation for fractals turns out to be T 6.6 , whereas the experimental value for Fe 3+ in frozen solutions of myoglobin azide is T 6.3 . Since we used d R =4/3 and the fracton range dimensionality d Φ =D/1.8, we expect to measure the dimensionalities of the problem by measuring the temperature dependence of the relaxation times. We have also calculated the shift of the paramagnetic resonance transition for a spin in a fractal for general dimensionalities. (author)

  10. Spin coherence in phosphorescent triplet states

    International Nuclear Information System (INIS)

    Hof, C.A. van 't

    1977-01-01

    The electron spin echo is studied on the dephasing mechanism in the photo-excited triplet state of quinoline in a durene host. First, a comparative investigation of the merits of the different spin echo techniques is presented. It turns out that the rotary echo generally yields a longer phase memory time than the two-pulse echo, whereas in the Carr-Purcell experiment, the dephasing can even be largely suppressed. Secondly, it is shown that the dephasing mechanism is determined by the nuclear spins of the guest molecules as well as those in the host material. A theoretical basis for interpreting the effect of vibronic relaxation on the decay rate of the rotary echo, as observed in parabenzoquinone, is given. Similar experiments in aniline reveal also that in this molecule, two close-lying triplet states exist, which is attributed to an inversion vibration analogous to the well-known example in ammonia

  11. Self-organized rock textures and multiring structure in the Duolun crater

    Science.gov (United States)

    Wu, Siben; Zhang, Jiayun

    1992-01-01

    The Duolun impact crater is a multiring basin located 200 km north of Beijing. From the center to the edge of the crater there are innermost rim, inner ring, outer rim, and outermost ring. Recently, we have found some self-organized textures or chaos phenomena in shock-metamorphic rocks from the Duolun impact crater, such as turbulence in matrices of impact glass, oscillatory zoning, or chemical chaos of spherulites in spherulitic splashed breccia, fractal wavy textures or self-similar wavy textures with varied scaling in impact glass, and crystallite beams shaped like Lorentz strange attractors. The rare phenomena indicate that the shock-metamorphic rocks from Duolun crater are formed far from equilibrium. If impact cratering generates momentarily under high-pressure and superhigh-temperature, occurrence of those chaos phenomena in shock-metamorphic rock is not surprising.

  12. Experimental and ab initio investigations on textured Li–Mn–O spinel thin film cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, J., E-mail: Julian.Fischer@kit.edu [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials (IAM), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Music, D. [RWTH Aachen University, Materials Chemistry, Kopernikusstrasse 10, 52074 Aachen (Germany); Bergfeldt, T.; Ziebert, C.; Ulrich, S.; Seifert, H.J. [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials (IAM), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2014-12-01

    This paper describes the tailored preparation of nearly identical lithium–manganese–oxide thin film cathodes with different global grain orientations. The thin films were synthesized by rf magnetron sputtering from a LiMn{sub 2}O{sub 4}-target in a pure argon plasma. Under appropriate processing conditions, thin films with a cubic spinel structure and a nearly similar density and surface topography but different grain orientation, i.e. (111)- and (440)-textured films, were achieved. The chemical composition was determined by inductively coupled plasma optical emission spectroscopy and carrier gas hot extraction. The constitution- and microstructure were evaluated by X-ray diffraction and Raman spectroscopy. The surface morphology and roughness were investigated by scanning electron and atomic force microscopy. The differently textured films represent an ideal model system for studying potential effects of grain orientation on the lithium ion diffusion and electrochemical behavior in LiMn{sub 2}O{sub 4}-based thin films. They are nearly identical in their chemical composition, atomic bonding behavior, surface-roughness, morphology and thickness. Our initial ab initio molecular dynamics data indicate that Li ion transport is faster in (111)-textured structure than in (440)-textured one. - Highlights: • Thin film model system of differently textured cubic Li–Mn–O spinels. • Investigation of the Li–Mn–O thin film mass density by X-ray reflectivity. • Ab initio molecular dynamics simulation on Li ion diffusion in LiMn{sub 2}O{sub 4}.

  13. Alluvial substrate mapping by automated texture segmentation of recreational-grade side scan sonar imagery.

    Science.gov (United States)

    Hamill, Daniel; Buscombe, Daniel; Wheaton, Joseph M

    2018-01-01

    Side scan sonar in low-cost 'fishfinder' systems has become popular in aquatic ecology and sedimentology for imaging submerged riverbed sediment at coverages and resolutions sufficient to relate bed texture to grain-size. Traditional methods to map bed texture (i.e. physical samples) are relatively high-cost and low spatial coverage compared to sonar, which can continuously image several kilometers of channel in a few hours. Towards a goal of automating the classification of bed habitat features, we investigate relationships between substrates and statistical descriptors of bed textures in side scan sonar echograms of alluvial deposits. We develop a method for automated segmentation of bed textures into between two to five grain-size classes. Second-order texture statistics are used in conjunction with a Gaussian Mixture Model to classify the heterogeneous bed into small homogeneous patches of sand, gravel, and boulders with an average accuracy of 80%, 49%, and 61%, respectively. Reach-averaged proportions of these sediment types were within 3% compared to similar maps derived from multibeam sonar.

  14. Infant Preference for Natural Texture Statistics is Modulated by Contrast Polarity.

    Science.gov (United States)

    Balas, Benjamin; Woods, Rebecca

    2014-01-01

    Adult observers are sensitive to statistical regularities present in natural images. Developmentally, research has shown that children do not show sensitivity to these natural regularities until approximately 8-10 years of age. This finding is surprising given that even infants gradually encode a range of high-level statistical regularities of their visual environment in the first year of life, We suggest that infants may in fact exhibit sensitivity to natural image statistics under circumstances where images of complex, natural textures, such as a photograph of rocks, are used as experimental stimuli and natural appearance is substantially manipulated. We tested this hypothesis by examining how infants' visual preference for real versus computer-generated synthetic textures was modulated by contrast negation, which produces an image similar to a photographic negative. We observed that older infants' (9-months of age) preferential looking behavior in this task was affected by contrast polarity, suggesting that the infant visual system is sensitive to deviations from natural texture appearance, including (1) discrepancies in appearance that differentiate natural and synthetic textures from one another and (2) the disruption of contrast polarity following negation. We discuss our results in the context of adult texture processing and the "perceptual narrowing" of visual recognition during the first year of life.

  15. Model-Based Learning of Local Image Features for Unsupervised Texture Segmentation

    Science.gov (United States)

    Kiechle, Martin; Storath, Martin; Weinmann, Andreas; Kleinsteuber, Martin

    2018-04-01

    Features that capture well the textural patterns of a certain class of images are crucial for the performance of texture segmentation methods. The manual selection of features or designing new ones can be a tedious task. Therefore, it is desirable to automatically adapt the features to a certain image or class of images. Typically, this requires a large set of training images with similar textures and ground truth segmentation. In this work, we propose a framework to learn features for texture segmentation when no such training data is available. The cost function for our learning process is constructed to match a commonly used segmentation model, the piecewise constant Mumford-Shah model. This means that the features are learned such that they provide an approximately piecewise constant feature image with a small jump set. Based on this idea, we develop a two-stage algorithm which first learns suitable convolutional features and then performs a segmentation. We note that the features can be learned from a small set of images, from a single image, or even from image patches. The proposed method achieves a competitive rank in the Prague texture segmentation benchmark, and it is effective for segmenting histological images.

  16. The effect of textured ballet shoe insoles on ankle proprioception in dancers.

    Science.gov (United States)

    Steinberg, Nili; Waddington, Gordon; Adams, Roger; Karin, Janet; Tirosh, Oren

    2016-01-01

    Impaired ankle inversion movement discrimination (AIMD) can lead to ankle sprain injuries. The aim of this study was to explore whether wearing textured insoles improved AIMD compared with barefoot, ballet shoes and smooth insoles, among dancers. Forty-four adolescent male and female dancers, aged 13-19, from The Australian Ballet School were tested for AIMD while barefoot, wearing ballet shoes, smooth insoles, and textured insoles. No interaction was found between the four different footwear conditions, the two genders, or the two levels of dancers in AIMD (p > .05). An interaction was found between the four different footwear conditions and the three tertiles when tested in ballet shoes (p = .006). Although significant differences were found between the upper tertiles and the lower tertiles when tested with ballet shoes, barefoot and with smooth insoles (p < .001; p < .001; p = .047, respectively), when testing with textured insoles dancers in the lower tertile obtained similar scores to those obtained by dancers in the upper tertile (p = .911). Textured insoles improved the discrimination scores of dancers with low AIMD, suggesting that textured insoles may trigger the cutaneous receptors in the plantar surface, increasing the awareness of ankle positioning, which in turn might decrease the chance of ankle injury. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Experimental and ab initio investigations on textured Li–Mn–O spinel thin film cathodes

    International Nuclear Information System (INIS)

    Fischer, J.; Music, D.; Bergfeldt, T.; Ziebert, C.; Ulrich, S.; Seifert, H.J.

    2014-01-01

    This paper describes the tailored preparation of nearly identical lithium–manganese–oxide thin film cathodes with different global grain orientations. The thin films were synthesized by rf magnetron sputtering from a LiMn 2 O 4 -target in a pure argon plasma. Under appropriate processing conditions, thin films with a cubic spinel structure and a nearly similar density and surface topography but different grain orientation, i.e. (111)- and (440)-textured films, were achieved. The chemical composition was determined by inductively coupled plasma optical emission spectroscopy and carrier gas hot extraction. The constitution- and microstructure were evaluated by X-ray diffraction and Raman spectroscopy. The surface morphology and roughness were investigated by scanning electron and atomic force microscopy. The differently textured films represent an ideal model system for studying potential effects of grain orientation on the lithium ion diffusion and electrochemical behavior in LiMn 2 O 4 -based thin films. They are nearly identical in their chemical composition, atomic bonding behavior, surface-roughness, morphology and thickness. Our initial ab initio molecular dynamics data indicate that Li ion transport is faster in (111)-textured structure than in (440)-textured one. - Highlights: • Thin film model system of differently textured cubic Li–Mn–O spinels. • Investigation of the Li–Mn–O thin film mass density by X-ray reflectivity. • Ab initio molecular dynamics simulation on Li ion diffusion in LiMn 2 O 4

  18. Fabrication and thermoelectric properties of highly textured NaCo2O4 ceramic

    International Nuclear Information System (INIS)

    Cheng Jinguang; Sui Yu; Fu Haijin; Lu Zhe; Wei Bo; Qian Zhengnan; Miao Jipeng; Liu Zhiguo; Huang Xiqiang; Zhu Ruibin; Wang Xianjie; Su Wenhui

    2006-01-01

    Highly textured NaCo 2 O 4 polycrystalline sample was fabricated by means of the cold high-pressure compacting followed by the solid-state reaction. X-ray diffraction and scanning electron microscope were employed to show that the plate-like grains within the sample are aligned along the pressing direction. The resistivity ρ and thermoelectric power S along the preferred {0 0 1} plane were measured in the whole temperature range from 15 to 973 K in air and the correlation between thermoelectric properties and texture was investigated. It was found that both ρ and S exhibit metallic behavior in the whole temperature range and the above sample exhibits lower ρ and higher S due to high texture and density. The power factor exhibits a steep rise above 400 K and reaches 761 μW m -1 K -2 at 973 K, suggesting a promising candidate for thermoelectric application at higher temperature. The change of slope in both resistivity and thermoelectric power curves at about 450 K might arise from the spin-state transition of Co ions in the CoO 2 blocks

  19. Aluminum oxide passivated radial junction sub-micrometre pillar array textured silicon solar cells

    Science.gov (United States)

    Pudasaini, Pushpa Raj; Elam, David; Ayon, Arturo A.

    2013-06-01

    We report radial, p-n junction, sub-micrometre, pillar array textured solar cells, fabricated on an n-type Czochralski silicon wafer. Relatively simple processing schemes such as metal-assisted chemical etching and spin on dopant techniques were employed for the fabrication of the proposed solar cells. Atomic layer deposition (ALD) grown aluminum oxide (Al2O3) was employed as a surface passivation layer on the B-doped emitter surface. In spite of the fact that the sub-micrometre pillar array textured surface has a relatively high surface-to-volume ratio, we observed an open circuit voltage (VOC) and a short circuit current density (JSC) as high as 572 mV and 29.9 mA cm-2, respectively, which leads to a power conversion efficiency in excess of 11.30%, for the optimized structure of the solar cell described herein. Broadband omnidirectional antireflection effects along with the light trapping property of the sub-micrometre, pillar array textured surface and the excellent passivation quality of the ALD-grown Al2O3 on the B-doped emitter surface were responsible for the enhanced electrical performance of the proposed solar cells.

  20. Grain morphology of YBCO coated superconductors prepared by spin process on Ni substrate

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.F.; Du, S.J.; Yan, G.; Xi, W.; Wu, X.; Pang, Y.; Wang, F.Y.; Liu, X.H.; Feng, Y.; Zhang, P.X.; Wu, X.Z.; Zhou, L

    2003-04-15

    The YBCO thick films with c-axis preferred orientation were prepared by spin and printing processes on Ni substrates (including cold rolling Ni, cube textured Ni, and cube textured Ni+self-oxided NiO). The results show that the chrysanthemum (or spherulite) and polygon morphology grains dominate the microstructure of YBCO films. The chrysanthemum size is about 0.2-0.5 mm range, some reaches 1 mm, and polygon grains normally are placed in the center of the chrysanthemum grains. No chrysanthemum grains appear in the thick films prepared on the substrate with Ag or YBCO intermediate layers.

  1. Optical spin generation/detection and spin transport lifetimes

    International Nuclear Information System (INIS)

    Miah, M. Idrish

    2011-01-01

    We generate electron spins in semiconductors by optical pumping. The detection of them is also performed by optical technique using time-resolved pump-probe photoluminescence polarization measurements in the presence of an external magnetic field perpendicular to the generated spin. The spin polarization in dependences of the pulse length, pump-probe delay and external magnetic field is studied. From the dependence of spin-polarization on the delay of the probe, the electronic spin transport lifetimes and the spin relaxation frequencies as a function of the strength of the magnetic field are estimated. The results are discussed based on hyperfine effects for interacting electrons.

  2. Optical spin generation/detection and spin transport lifetimes

    Energy Technology Data Exchange (ETDEWEB)

    Miah, M. Idrish, E-mail: m.miah@griffith.edu.au [Department of Physics, University of Chittagong, Chittagong 4331 (Bangladesh)

    2011-02-25

    We generate electron spins in semiconductors by optical pumping. The detection of them is also performed by optical technique using time-resolved pump-probe photoluminescence polarization measurements in the presence of an external magnetic field perpendicular to the generated spin. The spin polarization in dependences of the pulse length, pump-probe delay and external magnetic field is studied. From the dependence of spin-polarization on the delay of the probe, the electronic spin transport lifetimes and the spin relaxation frequencies as a function of the strength of the magnetic field are estimated. The results are discussed based on hyperfine effects for interacting electrons.

  3. Drag reduction through self-texturing compliant bionic materials

    Science.gov (United States)

    Liu, Eryong; Li, Longyang; Wang, Gang; Zeng, Zhixiang; Zhao, Wenjie; Xue, Qunji

    2017-01-01

    Compliant fish skin is effectively in reducing drag, thus the design and application of compliant bionic materials may be a good choice for drag reduction. Here we consider the drag reduction of compliant bionic materials. First, ZnO and PDMS mesh modified with n-octadecane were prepared, the drag reduction of self-texturing compliant n-octadecane were studied. The results show that the mesh modified by ZnO and PDMS possess excellent lipophilic and hydrophobic, thus n-octadecane at solid, semisolid and liquid state all have good adhesion with modified mesh. The states of n-octadecane changed with temperature, thus, the surface contact angle and adhesive force all varies obviously at different state. The contact angle decreases with temperature, the adhesive force shows a lower value at semisolid state. Furthermore, the drag testing results show that the compliant n-octadecane film is more effectively in drag reduction than superhydrophobic ZnO/PDMS film, indicating that the drag reduction mechanism of n-octadecane is significantly different with superhydrophobic film. Further research shows that the water flow leads to self-texturing of semisolid state n-octadecane, which is similar with compliant fish skin. Therefore, the compliant bionic materials of semisolid state n-octadecane with regular bulge plays a major role in the drag reduction.

  4. Texture Analysis Using Rényi’s Generalized Entropies

    NARCIS (Netherlands)

    Grigorescu, S.E.; Petkov, N.

    2003-01-01

    We propose a texture analysis method based on Rényi’s generalized entropies. The method aims at identifying texels in regular textures by searching for the smallest window through which the minimum number of different visual patterns is observed when moving the window over a given texture. The

  5. A dynamical system approach to texel identification in regular textures

    NARCIS (Netherlands)

    Grigorescu, S.E.; Petkov, N.; Loncaric, S; Neri, A; Babic, H

    2003-01-01

    We propose a texture analysis method based on Rényi’s entropies. The method aims at identifying texels in regular textures by searching for the smallest window through which the minimum number of different visual patterns is observed when moving the window over a given texture. The experimental

  6. TEXTURE ANALYSIS OF EXTRUDED APPLE POMACE - WHEAT SEMOLINA BLENDS

    Directory of Open Access Journals (Sweden)

    Ivan Bakalov

    2016-03-01

    Full Text Available Apple pomace - wheat semolina blends were extruded in a laboratory single screw extruder (Brabender 20 DN, Germany. Effects apple pomace content, moisture content, screw speed, and temperature of final cooking zone on texture of extrudates were studied applying response surface methodology. The texture characteristics of the extrudates were measured using a TA.XT Plus Texture Analyser, Stable Micro Systems.

  7. Brightness perception in low resolution images of 3d textures

    NARCIS (Netherlands)

    Spreeuwers, Lieuwe Jan; van der Heijden, Ferdinand; Siteur, J.

    1996-01-01

    A first step towards the analysis of the appearance of 3 dimensional textures is presented in this paper. It is assumed that the scale of the texture is small relative to the resolution of the camera. Therefore, the texture itself is not distinguishable.However, the perceived brightness of the

  8. Evaluation of texture differences among varieties of cooked quinoa

    Science.gov (United States)

    Texture is one of the most significant factors for consumers’ experience of foods. Texture difference of cooked quinoa among thirteen different varieties was studied. Correlations between the texture and seed composition, seed characteristics, cooking qualities, flour pasting properties and flour th...

  9. Line Laser and Triple Laser Quantification of the Difference in International Roughness Index between Textured and Non-Textured Strips

    Science.gov (United States)

    2017-07-01

    Practitioners have often wondered whether, during ride measurement with inertial devices, the motion of the laser through pavement texture introduces non representative values of international roughness index (IRI), particularly in certain textures. ...

  10. Thermoelectric spin voltage in graphene.

    Science.gov (United States)

    Sierra, Juan F; Neumann, Ingmar; Cuppens, Jo; Raes, Bart; Costache, Marius V; Valenzuela, Sergio O

    2018-02-01

    In recent years, new spin-dependent thermal effects have been discovered in ferromagnets, stimulating a growing interest in spin caloritronics, a field that exploits the interaction between spin and heat currents 1,2 . Amongst the most intriguing phenomena is the spin Seebeck effect 3-5 , in which a thermal gradient gives rise to spin currents that are detected through the inverse spin Hall effect 6-8 . Non-magnetic materials such as graphene are also relevant for spin caloritronics, thanks to efficient spin transport 9-11 , energy-dependent carrier mobility and unique density of states 12,13 . Here, we propose and demonstrate that a carrier thermal gradient in a graphene lateral spin valve can lead to a large increase of the spin voltage near to the graphene charge neutrality point. Such an increase results from a thermoelectric spin voltage, which is analogous to the voltage in a thermocouple and that can be enhanced by the presence of hot carriers generated by an applied current 14-17 . These results could prove crucial to drive graphene spintronic devices and, in particular, to sustain pure spin signals with thermal gradients and to tune the remote spin accumulation by varying the spin-injection bias.

  11. Noise in tunneling spin current across coupled quantum spin chains

    Science.gov (United States)

    Aftergood, Joshua; Takei, So

    2018-01-01

    We theoretically study the spin current and its dc noise generated between two spin-1 /2 spin chains weakly coupled at a single site in the presence of an over-population of spin excitations and a temperature elevation in one subsystem relative to the other, and we compare the corresponding transport quantities across two weakly coupled magnetic insulators hosting magnons. In the spin chain scenario, we find that applying a temperature bias exclusively leads to a vanishing spin current and a concomitant divergence in the spin Fano factor, defined as the spin current noise-to-signal ratio. This divergence is shown to have an exact analogy to the physics of electron scattering between fractional quantum Hall edge states and not to arise in the magnon scenario. We also reveal a suppression in the spin current noise that exclusively arises in the spin chain scenario due to the fermion nature of the spin-1/2 operators. We discuss how the spin Fano factor may be extracted experimentally via the inverse spin Hall effect used extensively in spintronics.

  12. Overview of spin physics

    Energy Technology Data Exchange (ETDEWEB)

    Yokosawa, A.

    1992-12-23

    Spin physics activities at medium and high energies became significantly active when polarized targets and polarized beams became accessible for hadron-hadron scattering experiments. My overview of spin physics will be inclined to the study of strong interaction using facilities at Argonne ZGS, Brookhaven AGS (including RHIC), CERN, Fermilab, LAMPF, an SATURNE. In 1960 accelerator physicists had already been convinced that the ZGS could be unique in accelerating a polarized beam; polarized beams were being accelerated through linear accelerators elsewhere at that time. However, there was much concern about going ahead with the construction of a polarized beam because (i) the source intensity was not high enough to accelerate in the accelerator, (ii) the use of the accelerator would be limited to only polarized-beam physics, that is, proton-proton interaction, and (iii) p-p elastic scattering was not the most popular topic in high-energy physics. In fact, within spin physics, [pi]-nucleon physics looked attractive, since the determination of spin and parity of possible [pi]p resonances attracted much attention. To proceed we needed more data beside total cross sections and elastic differential cross sections; measurements of polarization and other parameters were urgently needed. Polarization measurements had traditionally been performed by analyzing the spin of recoil protons. The drawbacks of this technique are: (i) it involves double scattering, resulting in poor accuracy of the data, and (ii) a carbon analyzer can only be used for a limited region of energy.

  13. Current-induced spin-orbit torques in ferromagnetic and antiferromagnetic systems

    KAUST Repository

    Manchon, Aurelien

    2018-01-29

    Spin-orbit coupling in inversion-asymmetric magnetic crystals and structures has emerged as a powerful tool to generate complex magnetic textures, interconvert charge and spin under applied current, and control magnetization dynamics. Current-induced spin-orbit torques mediate the transfer of angular momentum from the lattice to the spin system, leading to sustained magnetic oscillations or switching of ferromagnetic as well as antiferromagnetic structures. The manipulation of magnetic order, domain walls and skyrmions by spin-orbit torques provides evidence of the microscopic interactions between charge and spin in a variety of materials and opens novel strategies to design spintronic devices with potentially high impact in data storage, nonvolatile logic, and magnonic applications. This paper reviews recent progress in the field of spin-orbitronics, focusing on theoretical models, material properties, and experimental results obtained on bulk noncentrosymmetric conductors and multilayer heterostructures, including metals, semiconductors, and topological insulator systems. Relevant aspects for improving the understanding and optimizing the efficiency of nonequilibrium spin-orbit phenomena in future nanoscale devices are also discussed.

  14. Identification of a melting type variant among peach (P. persica L. Batsch) fruit textures by a digital penetrometer.

    Science.gov (United States)

    Ciacciulli, Angelo; Chiozzotto, Remo; Attanasio, Giovanna; Cirilli, Marco; Bassi, Daniele

    2017-12-20

    The increase of peach (Prunus persica L. Batsch) fruit shelf-life is one of the most important objectives of breeding activities, as peach is a highly perishable fruit which undergoes rapid softening during ripening. The loss of fruit firmness is accompanied by a modification of textural properties. At least four distinct textures were described in peach: melting, non-melting, stony-hard, and slow-melting (better defined as "slow-softening"). Flesh textures are usually discriminated using different approaches, specific for each type. Objective of this work was the development of a reliable method to assess flesh texture variants in peach fruit, with special attention to the slow-softening type which is currently scored by sensorial evaluation. A puncture-based test using a digital penetrometer was performed on 20 accessions belonging to the four textural groups, obtaining a series of rheological measures related to mechanical flesh properties and including Young's Modulus, Upper Yield Point, and Slope of Yield Stress. Among the components of elasto-plastic behavior of the fruits, the texture dynamic index (TD) was shown to be a reliable parameter to distinguish the group of melting flesh texture from slow-softening, non-melting, and stony-hard, these last resulting characterized by similar mechanical properties. The TD index can be applied to discriminate slow-softening and melting fruits, although variability within the different texture groups suggests the existence of accessions with intermediate phenotypes and minor quantitative trait variation. The availability of an objective method to clearly distinguish the melting from the slow-softening phenotypes paves the road to phenotype segregating progenies in order to find molecular markers associated to the slow-softening trait. The TD index could be considered to determine different textures in fleshy fruits in preharvest and postharvest, to support evaluation of quality for the intended use. © 2017 Wiley

  15. Surface scaling analysis of textured MgO thin films fabricated by energetic particle self-assisted deposition

    Science.gov (United States)

    Feng, Feng; Zhang, Xiangsong; Qu, Timing; Liu, Binbin; Huang, Junlong; Li, Jun; Xiao, Shaozhu; Han, Zhenghe; Feng, Pingfa

    2018-04-01

    In the fabrication of a high-temperature superconducting coated conductor, the surface roughness and texture of buffer layers can significantly affect the epitaxially grown superconductor layer. A biaxially textured MgO buffer layer fabricated by ion beam assisted deposition (IBAD) is widely used in the coated conductor manufacture due to its low thickness requirement. In our previous study, a new method called energetic particle self-assisted deposition (EPSAD), which employed only a sputtering deposition apparatus without an ion source, was proposed for fabricating biaxially textured MgO films on non-textured substrates. In this study, our aim was to investigate the deposition mechanism of EPSAD-MgO thin films. The behavior of the surface roughness (evaluated by Rq) was studied using atomic force microscopy (AFM) measurements with three scan scales, while the in-plane and out-of-plane textures were measured using X-ray diffraction (XRD). It was found that the variations of surface roughness and textures along with the increase in the thickness of EPSAD-MgO samples were very similar to those of IBAD-MgO reported in the literature, revealing the similarity of their deposition mechanisms. Moreover, fractal geometry was utilized to conduct the scaling analysis of EPSAD-MgO film's surface. Different scaling behaviors were found in two scale ranges, and the indications of the fractal properties in different scale ranges were discussed.

  16. Role of the antiferromagnetic bulk spins in exchange bias

    Energy Technology Data Exchange (ETDEWEB)

    Schuller, Ivan K. [Center for Advanced Nanoscience and Physics Department, University of California San Diego, La Jolla, CA 92093 (United States); Morales, Rafael, E-mail: rafael.morales@ehu.es [Department of Chemical-Physics & BCMaterials, University of the Basque Country UPV/EHU (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain); Batlle, Xavier [Departament Física Fonamental and Institut de Nanociència i Nanotecnologia, Universitat de Barcelona, c/ Martí i Franqués s/n, 08028 Barcelona, Catalonia (Spain); Nowak, Ulrich [Department of Physics, University of Konstanz, 78464 Konstanz (Germany); Güntherodt, Gernot [Physics Institute (IIA), RWTH Aachen University, Campus RWTH-Melaten, 52074 Aachen (Germany)

    2016-10-15

    This “Critical Focused Issue” presents a brief review of experiments and models which describe the origin of exchange bias in epitaxial or textured ferromagnetic/antiferromagnetic bilayers. Evidence is presented which clearly indicates that inner, uncompensated, pinned moments in the bulk of the antiferromagnet (AFM) play a very important role in setting the magnitude of the exchange bias. A critical evaluation of the extensive literature in the field indicates that it is useful to think of this bulk, pinned uncompensated moments as a new type of a ferromagnet which has a low total moment, an ordering temperature given by the AFM Néel temperature, with parallel aligned moments randomly distributed on the regular AFM lattice. - Highlights: • We address the role of bulk antiferromagnetic spins in the exchange bias phenomenon. • Significant experiments on how bulk AFM spins determine exchange bias are highlighted. • We explain the model that accounts for experimental results.

  17. Spin-orbit coupling in ultracold Fermi gases of 173Yb atoms

    Science.gov (United States)

    Song, Bo; He, Chengdong; Hajiyev, Elnur; Ren, Zejian; Seo, Bojeong; Cai, Geyue; Amanov, Dovran; Zhang, Shanchao; Jo, Gyu-Boong

    2017-04-01

    Synthetic spin-orbit coupling (SOC) in cold atoms opens an intriguing new way to probe nontrivial topological orders beyond natural conditions. Here, we report the realization of the SOC physics both in a bulk system and in an optical lattice. First, we demonstrate two hallmarks induced from SOC in a bulk system, spin dephasing in the Rabi oscillation and asymmetric atomic distribution in the momentum space respectively. Then we describe the observation of non-trivial spin textures and the determination of the topological phase transition in a spin-dependent optical lattice dressed by the periodic Raman field. Furthermore, we discuss the quench dynamics between topological and trivial states by suddenly changing the band topology. Our work paves a new way to study non-equilibrium topological states in a controlled manner. Funded by Croucher Foundation and Research Grants Council (RGC) of Hong Kong (Project ECS26300014, GRF16300215, GRF16311516, and Croucher Innovation Grants).

  18. Tunable spin-orbit coupling for ultracold atoms in two-dimensional optical lattices

    Science.gov (United States)

    Grusdt, Fabian; Li, Tracy; Bloch, Immanuel; Demler, Eugene

    2017-06-01

    Spin-orbit coupling (SOC) is at the heart of many exotic band structures and can give rise to many-body states with topological order. Here we present a general scheme based on a combination of microwave driving and lattice shaking for the realization of two-dimensional SOC with ultracold atoms in systems with inversion symmetry. We show that the strengths of Rashba and Dresselhaus SOC can be independently tuned in a spin-dependent square lattice. More generally, our method can be used to open gaps between different spin states without breaking time-reversal symmetry. We demonstrate that this allows for the realization of topological insulators with nontrivial spin textures closely related to the Kane-Mele model.

  19. Atomic structure governed diversity of exchange-driven spin helices in Fe nanoislands: Experiment and theory

    Science.gov (United States)

    Fischer, Jeison A.; Sandratskii, Leonid M.; Phark, Soo-hyon; Sander, Dirk; Parkin, Stuart

    2017-10-01

    We combine spin-polarized scanning tunneling microscopy (SP-STM) and first-principles calculations to demonstrate the control of the wavelength of helical spin textures in Fe nanoislands by varying their atomic structure. We make use of the complexity of submonolayer growth of Fe on Cu(111) to prepare nanoislands characterized by different thickness and in-plane atomic structure. SP-STM results reveal that the magnetic states of different nanoislands are spin helices. The wavelength of the spin helices varies strongly. Calculations performed for Fe films with different thickness and in-plane atomic structure explain the strong variation of the wavelength by a subtle balance in the competition between ferromagnetic and antiferromagnetic exchange interactions. We identify the crucial role of the effectively enhanced weak antiferromagnetic exchange interactions between distant atoms.

  20. Phosphorus leaching in a soil textural gradient

    DEFF Research Database (Denmark)

    Glæsner, Nadia; Kjærgaard, Charlotte; Rubæk, Gitte Holton

    2009-01-01

    Texture is a major factor influencing mobilization and transport of P in soil owing partly to differences in adsorptive properties, and partly to differences in pore-size distribution and pore organization. Slurry application strategies may be important mitigation measures for reducing agricultural...... in soils with matrix dominated flow behaviour We tested these hypotheses on three textural soil classes (Olsen-P 1.6 mg P 100 g-1) on intact soil columns (20*20 cm) and compared them to in situ P leaching before slurry application. In a loamy sand P leaching with both slurry application techniques slightly...... exceeded the in situ leaching. However, the two application techniques did not vary significantly. In a sandy and a clay loam preferential flow paths within the soil columns caused high P leaching when slurry was applied at the soil surface. The effect increased with increasing clay content. Injection...

  1. Soil texture reclassification by an ensemble model

    Science.gov (United States)

    Cisty, Milan; Hlavcova, Kamila

    2015-04-01

    Many environmental problems in which soil data serves as an inputs to simulation models are not restricted to national boundaries and therefore require international cooperation if solutions are to be found. The classification of soils according to their texture is one of the basic methods used for soil description. The term "soil texture" indicates the distribution of soil particles in the soil according to their size (diameter). The most preferred representation of texture classification is a grading curve. Because not all countries use the same classification system, databases from these countries cannot provide us with uniform data, which can serve as the inputs for various computations or models. This study deals with a description of a texture system reclassification to USDA classification system by the proposed model on a data set from Slovakia originally labeled by Slovakian national classification system. However, the authors of the paper suppose that the methodology proposed could be used more generally and that the information provided is also applicable when dealing with other existing soil texture classification systems. Some researchers have already proposed to fit the measured PSDs by various continuous parametric grading curves. When gaining such a relationship, it is possible to obtain a granular fraction's percentage ratio in the sample under consideration for any size of the particle diameter, which means that it is possible to get the values necessary for accomplishing a translation from one texture classification system to another. Several authors have conducted comparative studies on various PSD models in order to determine the best model for the soil groups selected for their studies (Nemes et al., 1999; Hwang, 2004; Botula et al., 2013). The reported findings of the abovementioned works somewhat differ from each other, and there is no generally suitable PSD model available. Because the transformation of a soil texture system is usually only

  2. SURFACE TEXTURE ANALYSIS FOR FUNCTIONALITY CONTROL

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Andreasen, Jan Lasson; Tosello, Guido

    This document is used in connection with three exercises of 3 hours duration as a part of the course VISION ONLINE – One week course on Precision & Nanometrology. The exercises concern surface texture analysis for functionality control, in connection with three different case stories. This docume...... contains a short description of each case story, 3-D roughness parameters analysis and relation with the product’s functionality.......This document is used in connection with three exercises of 3 hours duration as a part of the course VISION ONLINE – One week course on Precision & Nanometrology. The exercises concern surface texture analysis for functionality control, in connection with three different case stories. This document...

  3. Probabilistic Discrete Mixtures Colour Texture Models

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Havlíček, Vojtěch; Grim, Jiří

    2008-01-01

    Roč. 2008, č. 5197 (2008), s. 675-682 ISSN 0302-9743. [Iberoamerican Congress on Pattern Recognition /13./. Havana, 09.092008-12.09.2008] R&D Projects: GA AV ČR 1ET400750407; GA MŠk 1M0572; GA ČR GA102/07/1594; GA ČR GA102/08/0593 Grant - others:GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : Discrete distribution mixtures * EM algorithm * texture modeling Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2008/RO/haindl-havlicek-grim-probabilistic%20discrete%20mixtures%20colour%20texture%20models.pdf

  4. Topological image texture analysis for quality assessment

    Science.gov (United States)

    Asaad, Aras T.; Rashid, Rasber Dh.; Jassim, Sabah A.

    2017-05-01

    Image quality is a major factor influencing pattern recognition accuracy and help detect image tampering for forensics. We are concerned with investigating topological image texture analysis techniques to assess different type of degradation. We use Local Binary Pattern (LBP) as a texture feature descriptor. For any image construct simplicial complexes for selected groups of uniform LBP bins and calculate persistent homology invariants (e.g. number of connected components). We investigated image quality discriminating characteristics of these simplicial complexes by computing these models for a large dataset of face images that are affected by the presence of shadows as a result of variation in illumination conditions. Our tests demonstrate that for specific uniform LBP patterns, the number of connected component not only distinguish between different levels of shadow effects but also help detect the infected regions as well.

  5. Dropwise condensation on inclined textured surfaces

    CERN Document Server

    Khandekar, Sameer

    2014-01-01

    Dropwise Condensation on Textured Surfaces presents a holistic framework for understanding dropwise condensation through mathematical modeling and meaningful experiments. The book presents a review of the subject required to build up models as well as to design experiments. Emphasis is placed on the effect of physical and chemical texturing and their effect on the bulk transport phenomena. Application of the model to metal vapor condensation is of special interest. The unique behavior of liquid metals, with their low Prandtl number and high surface tension, is also discussed. The model predicts instantaneous drop size distribution for a given level of substrate subcooling and derives local as well as spatio-temporally averaged heat transfer rates and wall shear stress.

  6. Texture-based analysis of COPD

    DEFF Research Database (Denmark)

    Sørensen, Lauge; Nielsen, Mads; Lo, Pechin Chien Pau

    2012-01-01

    This study presents a fully automatic, data-driven approach for texture-based quantitative analysis of chronic obstructive pulmonary disease (COPD) in pulmonary computed tomography (CT) images. The approach uses supervised learning where the class labels are, in contrast to previous work, based...... on measured lung function instead of on manually annotated regions of interest (ROIs). A quantitative measure of COPD is obtained by fusing COPD probabilities computed in ROIs within the lung fields where the individual ROI probabilities are computed using a k nearest neighbor (kNN ) classifier. The distance...... and subsequently applied to classify 200 independent images from the same screening trial. The texture-based measure was significantly better at discriminating between subjects with and without COPD than were the two most common quantitative measures of COPD in the literature, which are based on density...

  7. Composite biaxially textured substrates using ultrasonic consolidation

    Science.gov (United States)

    Blue, Craig A; Goyal, Amit

    2013-04-23

    A method of forming a composite sheet includes disposing an untextured metal or alloy first sheet in contact with a second sheet in an aligned opposing position; bonding the first sheet to the second sheet by applying an oscillating ultrasonic force to at least one of the first sheet and the second sheet to form an untextured intermediate composite sheet; and annealing the untextured intermediate composite sheet at a temperature lower than a primary re-crystallization temperature of the second sheet and higher than a primary re-crystallization temperature of the first sheet to convert the untextured first sheet into a cube textured sheet, wherein the cube texture is characterized by a .phi.-scan having a FWHM of no more than 15.degree. in all directions, the second sheet remaining untextured, to form a composite sheet.

  8. Quantum spin transistor with a Heisenberg spin chain

    Science.gov (United States)

    Marchukov, O. V.; Volosniev, A. G.; Valiente, M.; Petrosyan, D.; Zinner, N. T.

    2016-01-01

    Spin chains are paradigmatic systems for the studies of quantum phases and phase transitions, and for quantum information applications, including quantum computation and short-distance quantum communication. Here we propose and analyse a scheme for conditional state transfer in a Heisenberg XXZ spin chain which realizes a quantum spin transistor. In our scheme, the absence or presence of a control spin excitation in the central gate part of the spin chain results in either perfect transfer of an arbitrary state of a target spin between the weakly coupled input and output ports, or its complete blockade at the input port. We also discuss a possible proof-of-concept realization of the corresponding spin chain with a one-dimensional ensemble of cold atoms with strong contact interactions. Our scheme is generally applicable to various implementations of tunable spin chains, and it paves the way for the realization of integrated quantum logic elements. PMID:27721438

  9. Spin gating electrical current

    Science.gov (United States)

    Ciccarelli, C.; Zârbo, L. P.; Irvine, A. C.; Campion, R. P.; Gallagher, B. L.; Wunderlich, J.; Jungwirth, T.; Ferguson, A. J.

    2012-09-01

    The level of the chemical potential is a fundamental parameter of the electronic structure of a physical system, which consequently plays an important role in defining the properties of active electrical devices. We directly measure the chemical potential shift in the relativistic band structure of the ferromagnetic semiconductor (Ga,Mn)As, controlled by changes in its magnetic order parameter. Our device comprises a non-magnetic aluminum single electron channel capacitively coupled to the (Ga,Mn)As gate electrode. The chemical potential shifts of the gate are directly read out from the shifts in the Coulomb blockade oscillations of the single electron transistor. The experiments introduce a concept of spin gating electrical current. In our spin transistor spin manipulation is completely removed from the electrical current carrying channel.

  10. SPIN-selling

    CERN Document Server

    Rackham, Neil

    1995-01-01

    True or false? In selling high-value products or services: "closing" increases your chance of success; it is essential to describe the benefits of your product or service to the customer; objection handling is an important skill; and open questions are more effective than closed questions. All false, says Neil Rackham. He and his team studied more than 35,000 sales calls made by 10,000 sales people in 23 countries over 12 years. Their findings revealed that many of the methods developed for selling low-value goods just don't work for major sales. Rackham went on to introduce his SPIN-selling method, where SPIN describes the whole selling process - Situation questions, Problem questions, Implication questions, Need-payoff questions. SPIN-selling provides you with a set of simple and practical techniques which have been tried in many of today's leading companies with dramatic improvements to their sales performance.

  11. Chiral higher spin gravity

    Science.gov (United States)

    Krishnan, Chethan; Raju, Avinash

    2017-06-01

    We construct a candidate for the most general chiral higher spin theory with AdS3 boundary conditions. In the Chern-Simons language, on the left it has the Drinfeld-Sokolov reduced form, but on the right all charges and chemical potentials are turned on. Altogether (for the spin-3 case) these are 19 functions. Despite this, we show that the resulting metric has the form of the "most general" AdS3 boundary conditions discussed by Grumiller and Riegler. The asymptotic symmetry algebra is a product of a W3 algebra on the left and an affine s l (3 )k current algebra on the right, as desired. The metric and higher spin fields depend on all the 19 functions. We compare our work with previous results in the literature.

  12. Spin Waves in Terbium

    DEFF Research Database (Denmark)

    Jensen, J.; Houmann, Jens Christian Gylden

    1975-01-01

    The selection rules for the linear couplings between magnons and phonons propagating in the c direction of a simple basal-plane hcp ferromagnet are determined by general symmetry considerations. The acoustic-optical magnon-phonon interactions observed in the heavy-rare-earth metals have been...... explained by Liu as originating from the mixing of the spin states of the conduction electrons due to the spin-orbit coupling. We find that this coupling mechanism introduces interactions which violate the selection rules for a simple ferromagnet. The interactions between the magnons and phonons propagating...... in the c direction of Tb have been studied experimentally by means of inelastic neutron scattering. The magnons are coupled to both the acoustic- and optical-transverse phonons. By studying the behavior of the acoustic-optical coupling, we conclude that it is a spin-mixed-induced coupling as proposed...

  13. Recent advances in the spin Hall effect of light

    Science.gov (United States)

    Ling, Xiaohui; Zhou, Xinxing; Huang, Kun; Liu, Yachao; Qiu, Cheng-Wei; Luo, Hailu; Wen, Shuangchun

    2017-06-01

    The spin Hall effect (SHE) of light, as an analogue of the SHE in electronic systems, is a promising candidate for investigating the SHE in semiconductor spintronics/valleytronics, high-energy physics and condensed matter physics, owing to their similar topological nature in the spin-orbit interaction. The SHE of light exhibits unique potential for exploring the physical properties of nanostructures, such as determining the optical thickness, and the material properties of metallic and magnetic thin films and even atomically thin two-dimensional materials. More importantly, it opens a possible pathway for controlling the spin states of photons and developing next-generation photonic spin Hall devices as a fundamental constituent of the emerging spinoptics. In this review, based on the viewpoint of the geometric phase gradient, we give a detailed presentation of the recent advances in the SHE of light and its applications in precision metrology and future spin-based photonics.

  14. Exploring Sound-Motion Textures in drum set performance

    DEFF Research Database (Denmark)

    Godøy, Rolf Inge; song, minho; Dahl, Sofia

    2017-01-01

    A musical texture, be that of an ensemble or of a solo in- strumentalist, may be perceived as combinations of both simultaneous and sequential sound events. However, we believe that also sensations of the corresponding sound- producing events (e.g. hitting, stroking, bowing, blowing) contribute...... to our perceptions of musical textures. Musical textures could thus be understood as multimodal, with features of both sound and motion, hence the idea here of sound-motion textures in music. The study of such multi- modal sound-motion textures will necessitate collecting and analyzing data of both...

  15. Influence of texture on the physical properties of materials

    International Nuclear Information System (INIS)

    Penelle, R.; Baudin, T.

    1996-01-01

    The principles of crystallographic texture characterization by the means of X-ray or neutron diffraction statistical techniques are reviewed, and examples of their application to the study of the effects of texture on the properties of materials are presented: texture of magnetic steels, magneto-crystalline anisotropy, elasticity anisotropy and Young's modulus, plastic anisotropy (textural hardening), residual stresses. Neutron diffraction allows for the continuous monitoring of the recrystallization texture generation kinetics during in-situ annealing or for the follow-up of phase transformations. Backscattered electron diffraction allows for the quantification of the spatial distribution of grain and grain joint orientations and thus microstructure reconstruction

  16. Texture modelling by discrete distribution mixtures

    Czech Academy of Sciences Publication Activity Database

    Grim, Jiří; Haindl, Michal

    2003-01-01

    Roč. 41, 3-4 (2003), s. 603-615 ISSN 0167-9473 R&D Projects: GA ČR GA102/00/0030; GA AV ČR KSK1019101 Institutional research plan: CEZ:AV0Z1075907 Keywords : discrete distribution mixtures * EM algorithm * texture modelling Subject RIV: JC - Computer Hardware ; Software Impact factor: 0.711, year: 2003

  17. Colour texture segmentation using modelling approach

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Mikeš, Stanislav

    2005-01-01

    Roč. 3687, č. - (2005), s. 484-491 ISSN 0302-9743. [International Conference on Advances in Pattern Recognition /3./. Bath, 22.08.2005-25.08.2005] R&D Projects: GA MŠk 1M0572; GA AV ČR 1ET400750407; GA AV ČR IAA2075302 Institutional research plan: CEZ:AV0Z10750506 Keywords : colour texture segmentation * image models * segmentation benchmark Subject RIV: BD - Theory of Information

  18. Dynamic texture as foreground and background

    Czech Academy of Sciences Publication Activity Database

    Chetverikov, D.; Fazekas, S.; Haindl, Michal

    2011-01-01

    Roč. 22, č. 5 (2011), s. 741-750 ISSN 0932-8092 R&D Projects: GA ČR GA102/08/0593 EU Projects: European Commission(XE) 507752 - MUSCLE Institutional research plan: CEZ:AV0Z10750506 Keywords : Dynamic texture * Optical flow * SVD Subject RIV: BD - Theory of Information Impact factor: 1.009, year: 2011 http://library.utia.cas.cz/separaty/2011/RO/haindl-0345450.pdf

  19. Nominated Texture Based Cervical Cancer Classification

    Directory of Open Access Journals (Sweden)

    Edwin Jayasingh Mariarputham

    2015-01-01

    Full Text Available Accurate classification of Pap smear images becomes the challenging task in medical image processing. This can be improved in two ways. One way is by selecting suitable well defined specific features and the other is by selecting the best classifier. This paper presents a nominated texture based cervical cancer (NTCC classification system which classifies the Pap smear images into any one of the seven classes. This can be achieved by extracting well defined texture features and selecting best classifier. Seven sets of texture features (24 features are extracted which include relative size of nucleus and cytoplasm, dynamic range and first four moments of intensities of nucleus and cytoplasm, relative displacement of nucleus within the cytoplasm, gray level cooccurrence matrix, local binary pattern histogram, tamura features, and edge orientation histogram. Few types of support vector machine (SVM and neural network (NN classifiers are used for the classification. The performance of the NTCC algorithm is tested and compared to other algorithms on public image database of Herlev University Hospital, Denmark, with 917 Pap smear images. The output of SVM is found to be best for the most of the classes and better results for the remaining classes.

  20. Model for understanding consumer textural food choice.

    Science.gov (United States)

    Jeltema, Melissa; Beckley, Jacqueline; Vahalik, Jennifer

    2015-05-01

    The current paradigm for developing products that will match the marketing messaging is flawed because the drivers of product choice and satisfaction based on texture are misunderstood. Qualitative research across 10 years has led to the thesis explored in this research that individuals have a preferred way to manipulate food in their mouths (i.e., mouth behavior) and that this behavior is a major driver of food choice, satisfaction, and the desire to repurchase. Texture, which is currently thought to be a major driver of product choice, is a secondary factor, and is important only in that it supports the primary driver-mouth behavior. A model for mouth behavior is proposed and the qualitative research supporting the identification of different mouth behaviors is presented. The development of a trademarked typing tool for characterizing mouth behavior is described along with quantitative substantiation of the tool's ability to group individuals by mouth behavior. The use of these four groups to understand textural preferences and the implications for a variety of areas including product design and weight management are explored.

  1. Crystallographic texture and mechanical anisotropy of zircaloys

    International Nuclear Information System (INIS)

    Hussien, S.A.

    1987-01-01

    Hexagonal-closed-packed metals are inherently anisotropic, and deformation during processing leads to the development of preferred orientation or texture in the finished product. Tube Reduced Extrusions (TREXs) are an intermediate product in the production of zircaloy canning tubes for nuclear reactors. The objective of this research has been to study the mechanical anisotropy which has a direct relation to the formability of Zircaloy TREXs. Anisotropy parameters (R and P) in the modified Hills equation were investigated. The use of the impression test for measuring R and P under different annealing temperatures, test temperatures and strain rates, and the grid-analysis technique for measuring R and P gradients through the TREX thickness are demonstrated. The mechanical-test results are compared with the predictions of the Bishop-Hill model using the quantitative orientation distribution function. There is a good agreement between the model prediction and the mechanical-test data. The value of R was found to be insensitive to the strain rate, test temperature, annealing temperature, and texture gradient. The value of P was found to increase with the annealing temperature within the recrystallization range and to be relatively insensitive elsewhere, to decrease with increasing test temperature and to be considerable sensitive to texture gradient

  2. Calculation of skid resistance from texture measurements

    Directory of Open Access Journals (Sweden)

    Andreas Ueckermann

    2015-02-01

    Full Text Available There is a wide range of routine skid resistance measurement devices on the market. All of them are measuring the friction force between a rubber wheel and the wetted road surface. Common to all of them is that they are relatively complex and costly because generally a truck carrying a large water tank is needed to wet the surface with a defined water layer. Because of the limited amount of water they can carry they are limited in range. Besides that the measurement is depending on factors like water film thickness, temperature, measurement speed, rubber aging, rubber wear and even road evenness and curviness. All of these factors will affect the skid resistance and are difficult to control. We present a concept of contactless skid resistance measurement which is based on optical texture measurement and consists of two components: measurement of the pavement texture by means of an optical measuring system and calculation of the skid resistance based on the measured texture by means of a rubber friction model. The basic assumptions underlying the theoretical approach and the model itself based on the theory of Persson are presented. The concept is applied to a laboratory device called Wehner/Schulze (W/S machine to prove the theoretical approach. The results are very promising. A strong indication could be provided that skid resistance could be measured without contact in the future.

  3. Modelling Thermal Diffusivity of Differently Textured Soils

    Science.gov (United States)

    Lukiashchenko, K. I.; Arkhangelskaya, T. A.

    2018-02-01

    A series of models has been proposed for estimating thermal diffusivity of soils at different water contents. Models have been trained on 49 soil samples with the texture range from sands to silty clays. The bulk density of the studied soils varied from 0.86 to 1.82 g/cm3; the organic carbon was between 0.05 and 6.49%; the physical clay ranged from 1 to 76%. The thermal diffusivity of undisturbed soil cores measured by the unsteady-state method varied from 0.78×10-7 m2/s for silty clay at the water content of 0.142 cm3/cm3 to 10.09 × 10-7 m2/s for sand at the water content of 0.138 cm3/cm3. Each experimental curve was described by the four-parameter function proposed earlier. Pedotransfer functions were then developed to estimate the parameters of the thermal diffusivity vs. water content function from data on soil texture, bulk density, and organic carbon. Models were tested on 32 samples not included in the training set. The root mean square errors of the best-performing models were 17-38%. The models using texture data performed better than the model using only data on soil bulk density and organic carbon.

  4. Focal Conic Flower Textures at Curved Interfaces

    Directory of Open Access Journals (Sweden)

    Daniel A. Beller

    2013-12-01

    Full Text Available Focal conic domains (FCDs in smectic-A liquid crystals have drawn much attention, both for their exquisitely structured internal form and for their ability to direct the assembly of micromaterials and nanomaterials in a variety of patterns. A key to directing FCD assembly is control over the eccentricity of the domain. Here, we demonstrate a new paradigm for creating spatially varying FCD eccentricity by confining a hybrid-aligned smectic with curved interfaces. In particular, we manipulate interface behavior with colloidal particles in order to experimentally produce two examples of what has recently been dubbed the flower texture [C. Meyer et al., Focal Conic Stacking in Smectic A Liquid Crystals: Smectic Flower and Apollonius Tiling, Materials 2, 499, 2009MATEG91996-194410.3390/ma2020499], where the focal hyperbolæ diverge radially outward from the center of the texture, rather than inward as in the canonical éventail or fan texture. We explain how this unconventional assembly can arise from appropriately curved interfaces. Finally, we present a model for this system that applies the law of corresponding cones, showing how FCDs may be embedded smoothly within a “background texture” of large FCDs and concentric spherical layers, in a manner consistent with the qualitative features of the smectic flower. Such understanding could potentially lead to disruptive liquid-crystal technologies beyond displays, including patterning, smart surfaces, microlens arrays, sensors, and nanomanufacturing.

  5. Spinning geodesic Witten diagrams

    International Nuclear Information System (INIS)

    Dyer, Ethan; Freedman, Daniel Z.; Massachusetts Institute of Technology; Massachusetts Institute of Technology; Sully, James; McGill University, Montreal, QC

    2017-01-01

    We present an expression for the four-point conformal blocks of symmetric traceless operators of arbitrary spin as an integral over a pair of geodesics in Anti-de Sitter space, generalizing the geodesic Witten diagram formalism of Hijano et al. to arbitrary spin. As an intermediate step in the derivation, we identify a convenient basis of bulk threepoint interaction vertices which give rise to all possible boundary three point structures. Lastly, we highlight a direct connection between the representation of the conformal block as geodesic Witten diagram and the shadow operator formalism.

  6. Spin gating electrical current

    Czech Academy of Sciences Publication Activity Database

    Ciccarelli, C.; Zarbo, Liviu; Irvine, A.C.; Campion, R. P.; Gallagher, B. L.; Wunderlich, Joerg; Jungwirth, Tomáš; Ferguson, A.J.

    2012-01-01

    Roč. 101, č. 12 (2012), , , "122411-1"-"122411-4" ISSN 0003-6951 R&D Projects: GA AV ČR KJB100100802; GA AV ČR KAN400100652 EU Projects: European Commission(XE) 268066 - 0MSPIN; European Commission(XE) 215368 - SemiSpinNet Grant - others:AV ČR(CZ) AP0801 Program:Akademická prémie - Praemium Academiae Institutional research plan: CEZ:AV0Z10100521 Keywords : ferromagnetic resonance * spin-orbit coupling * nanodevices Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.794, year: 2012 http://arxiv.org/abs/1203.2439

  7. Spin echo in synchrotrons

    Directory of Open Access Journals (Sweden)

    Alexander W. Chao

    2007-01-01

    Full Text Available As a polarized beam is accelerated through a depolarization resonance, its polarization is reduced by a well-defined calculable reduction factor. When the beam subsequently crosses a second resonance, the final beam polarization is considered to be reduced by the product of the two reduction factors corresponding to the two crossings, each calculated independently of the other. This is a good approximation when the spread of spin precession frequency Δν_{spin} of the beam (particularly due to its energy spread is sufficiently large that the spin precession phases of individual particles smear out completely during the time τ between the two crossings. This approximate picture, however, ignores two spin dynamics effects: an interference-overlap effect and a spin echo effect. This paper is to address these two effects. The interference-overlap effect occurs when Δν_{spin} is too small, or when τ is too short, to complete the smearing process. In this case, the two resonance crossings overlap each other, and the final polarization exhibits constructive or destructive interference patterns depending on the exact value of τ. Typically, the beam’s energy spread is large and this interference-overlap effect does not occur. To study this effect, therefore, it is necessary to reduce the beam energy spread and to consider two resonance crossings very close to each other. The other mechanism, also due to the interplay between two resonance crossings, is spin echo. It turns out that even when the precession phases appear to be completely smeared between the two crossings, there will still be a sudden and short-lived echo signal of beam polarization at a time τ after the second crossing; the magnitude of which can be as large as 57%. This echo signal exists even when the beam has a sizable energy spread and when τ is very large, and could be a sensitive (albeit challenging way to experimentally test the intricate spin dynamics in a synchrotron

  8. Spin, gravity, and inertia.

    Science.gov (United States)

    Obukhov, Y N

    2001-01-08

    The gravitational effects in the relativistic quantum mechanics are investigated. The exact Foldy-Wouthuysen transformation is constructed for the Dirac particle coupled to the static spacetime metric. As a direct application, we analyze the nonrelativistic limit of the theory. The new term describing the specific spin (gravitational moment) interaction effect is recovered in the Hamiltonian. The comparison of the true gravitational coupling with the purely inertial case demonstrates that the spin relativistic effects do not violate the equivalence principle for the Dirac fermions.

  9. Analysis of partially textured slider and journal bearing

    Science.gov (United States)

    Rao, T. V. V. L. N.; Rani, A. M. A.; Nagarajan, T.; Hashim, F. M.

    2012-06-01

    The partial texturing of bearing surfaces with different shapes of textures and at different locations is an effective approach to improve the performance of bearings. The present study examines the effects of texture configuration on improvement in load capacity and reduction in friction coefficient for slider and journal bearing. This work presents nondimensional pressure expressions for the partially textured slider and journal bearing. The nondimensional pressure expressions are derived taking into consideration of texture geometry and extent of partial texture on the bearing surface. The Reynolds boundary conditions are used in the analysis to predict nondimensional load capacity and coefficient of friction. Even for nominally parallel surfaces, partial texturing of bearing surfaces has a potential to generate load carrying capacity and reduce coefficient of friction.

  10. Scale-Space Mutual Information for Textural-Patterns Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Seedahmed, Gamal H.; Ward, Andy L.

    2005-08-22

    The essence of image texture is typically understood by two aspects. First, within a texture-pattern there is a significant variation in intensity values between nearby pixels. Second, texture is a homogeneous property at some spatial scale larger than the spatial resolution of the image. Motivated by the essential aspects of image texture, this paper proposes a novel methodology that combines the use of scale-space and mutual information to characterize textural-patterns. Scale-space offers the mechanism for a multi-scale representation of the image, which will be used to address the scale aspect of texture. On the other hand, mutual information provides a measure to quantify the dependency relationship across the scale-space. It has been found that the proposed methodology has the potential to capture different properties of texture such as periodicity, scale, fineness, coarseness, and spatial extent or size. Practical examples are provided to demonstrate the applicability of the proposed methodology.

  11. A Novel Texture Classification Procedure by using Association Rules

    Directory of Open Access Journals (Sweden)

    L. Jaba Sheela

    2008-11-01

    Full Text Available Texture can be defined as a local statistical pattern of texture primitives in observer’s domain of interest. Texture classification aims to assign texture labels to unknown textures, according to training samples and classification rules. Association rules have been used in various applications during the past decades. Association rules capture both structural and statistical information, and automatically identify the structures that occur most frequently and relationships that have significant discriminative power. So, association rules can be adapted to capture frequently occurring local structures in textures. This paper describes the usage of association rules for texture classification problem. The performed experimental studies show the effectiveness of the association rules. The overall success rate is about 98%.

  12. Automatic Texture Optimization for 3D Urban Reconstruction

    Directory of Open Access Journals (Sweden)

    LI Ming

    2017-03-01

    Full Text Available In order to solve the problem of texture optimization in 3D city reconstruction by using multi-lens oblique images, the paper presents a method of seamless texture model reconstruction. At first, it corrects the radiation information of images by camera response functions and image dark channel. Then, according to the corresponding relevance between terrain triangular mesh surface model to image, implements occlusion detection by sparse triangulation method, and establishes the triangles' texture list of visible. Finally, combines with triangles' topology relationship in 3D triangular mesh surface model and means and variances of image, constructs a graph-cuts-based texture optimization algorithm under the framework of MRF(Markov random filed, to solve the discrete label problem of texture optimization selection and clustering, ensures the consistency of the adjacent triangles in texture mapping, achieves the seamless texture reconstruction of city. The experimental results verify the validity and superiority of our proposed method.

  13. Texture evolution during the recrystallization of a warm-rolled low-carbon steel

    International Nuclear Information System (INIS)

    Sanchez-Araiza, M.; Godet, S.; Jacques, P.J.; Jonas, J.J.

    2006-01-01

    The texture changes taking place during the recrystallization of a warm-rolled low-carbon steel were examined using electron backscattered diffraction. The deformation textures of the warm-rolled material are similar in shape to those of cold-rolled materials, but are somewhat more intense. The recrystallization textures resemble the deformation textures but with a more extended α fibre that includes the {1 1 3} orientation; the γ fibre extends to the {5 5 4} orientation. These two orientations are related to the {1 1 2} deformed grains by near 26 deg, rotations about selected axes. Nevertheless, both orientations appear in the early stages of recrystallization, an observation that does not support the oriented growth theory. The {1 1 1} orientations are the first to recrystallize while the α fibre is present until the end of recrystallization. It is finally consumed by all types of grains as well as by subgrain coalescence. The similarities in the growth rates for the {1 1 1} and random orientations and the late disappearance of the α fibre suggest that recrystallization takes place according to the high stored energy oriented nucleation concept

  14. Spin Superfluidity and Magnone BEC in He-3

    Science.gov (United States)

    Bunkov, Yury

    2011-03-01

    The spin superfluidity -- superfluidity in the magnetic subsystem of a condensed matter -- is manifested as the spontaneous phase-coherent precession of spins first discovered in 1984 in 3 He-B. This superfluid current of spins -- spin supercurrent -- is one more representative of superfluid currents known or discussed in other systems, such as the superfluid current of mass and atoms in superfluid 4 He; superfluid current of electric charge in superconductors; superfluid current of hypercharge in Standard Model of particle physics; superfluid baryonic current and current of chiral charge in quark matter; etc. Spin superfluidity can be described in terms of the Bose condensation of spin waves -- magnons. We discuss different states of magnon superfluidity with different types of spin-orbit coupling: in bulk 3 He-B; magnetically traped `` Q -balls'' at very low temperatures; in 3 He-A and 3 He-B immerged in deformed aerogel; etc. Some effects in normal 3 He can also be treated as a magnetic BEC of fermi liquid. A very similar phenomena can be observed also in a magnetic systems with dinamical frequensy shift, like MnC03 . We will discuss the main experimental signatures of magnons superfluidity: (i) spin supercurrent, which transports the magnetization on a macroscopic distance more than 1 cm long; (ii) spin current Josephson effect which shows interference between two condensates; (iii) spin current vortex -- a topological defect which is an analog of a quantized vortex in superfluids, of an Abrikosov vortex in superconductors, and cosmic strings in relativistic theories; (iv) Goldstone modes related to the broken U (1) symmetry -- phonons in the spin-superfluid magnon gas; etc. For recent review see Yu. M. Bunkov and G. E. Volovik J. Phys. Cond. Matter. 22, 164210 (2010) This work is partly supported by the Ministry of Education and Science of the Russian Federation (contract N 02.740.11.5217).

  15. A stochastic picture of spin

    International Nuclear Information System (INIS)

    Faris, W.G.

    1981-01-01

    Dankel has shown how to incorporate spin into stochastic mechanics. The resulting non-local hidden variable theory gives an appealing picture of spin correlation experiments in which Bell's inequality is violated. (orig.)

  16. Physical, chemical and texture characteristics of Aro cheese

    Directory of Open Access Journals (Sweden)

    González, M.L.

    2017-10-01

    Full Text Available In 2016, Mexico’s total annual production of cheese was 375,181 tons. Cheese is widely consumed among all socioeconomic groups, and the decision to purchase this product is based on income, with a wide variety of cheeses, brands, and styles available. The fresco cheese is the most popular type and is mostly produced according to traditional or artisanal methods in small family businesses, and small and medium-sized enterprises. It is made with the milk of the producers' livestock, giving it an added value. In Mexico, however, there is not enough scientific information related to the characterization of various dairy products of artisanal production, for example, Aro cheese. The aim of the present study was to define the physical, chemical, and rheological characteristics of the Aro cheese that is commercialized in Teotitlán de Flores Magón, Oaxaca, Mexico. Twenty-four samples of Aro cheese were collected in four establishments with high sales in Teotitlán de Flores Magón, Oaxaca, for analysis physical (Diameter, weight, height and color, chemical (pH, acidity, aw, chlorides, moisture, ashes, protein and fat, and texture (hardness, springiness, adhesiveness and cohesiveness. No difference was found in weight, diameter, height, and color (L* and b*. However, differences in hardness and cohesiveness were found. Although Aro cheese is characterized as an enzymatically coagulated cheese, pH values of 5.82 to 6.08 were recorded, and the data relating to moisture, protein, fat, and chlorides are similar to other Mexican fresh cheeses. The cheese of Aro that is commercialized in Teotitlán de Flores Magón, presents similar physical, chemical and texture characteristics to other fresh cheeses of artisanal production.

  17. Neurite development in PC12 cells on flexible micro-textured substrates under cyclic stretch.

    Science.gov (United States)

    Haq, Furqan; Keith, Charles; Zhang, Guigen

    2006-01-01

    We investigated the combined effect of micro-texture and mechanical strain on neuronal cell development such as neurite length and neurite density in a rat pheochromocytoma cell line (PC12 cells). Cells were seeded on flexible silicone substrates with micro-texture or no texture (smooth) and cultured under static and dynamic conditions. In the static condition substrates were not stretched and in the dynamic conditions substrates were subjected to cyclic uniaxial stretching at three different strain levels of 4%, 8%, and 16% with each at three different strain rates at 0.1, 0.5, and 1.0 Hz. Results showed that of all cell cultures there was no significant difference in neurite development between cells on smooth and textured substrates, except in the static and 4% at 0.1 Hz conditions, where micro-texture induced significantly longer neurites. With both types of substrates, a lower mechanical condition (4% at 1.0 Hz or 16% at 0.1 Hz) resulted in more and longer neurites and lower cell density, and a higher mechanical condition (16% at 1.0 Hz) resulted in fewer and shorter neurites and lower cell density as compared to the static condition. These findings suggest that the effect of the micro-texture on neurite development is more prominent in low mechanical conditions than in high mechanical conditions and that the strain level and strain rate have an interrelated effect on neurite development: a higher strain level at a lower strain rate has a similar effect as a lower strain level at a higher strain rate in terms of promoting neurite development.

  18. Unmixing of spectrally similar minerals

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2009-01-01

    Full Text Available techniques is complicated when considering very similar spectral signatures. Iron-bearing oxide/hydroxide/sulfate minerals have similar spectral signatures. The study focuses on how could estimates of abundances of spectrally similar iron-bearing oxide...

  19. Antiferromagnetic spin-orbitronics

    KAUST Repository

    Manchon, Aurelien

    2015-05-01

    Antiferromagnets have long remained an intriguing and exotic state of matter, whose application has been restricted to enabling interfacial exchange bias in metallic and tunneling spin-valves [1]. Their role in the expanding field of applied spintronics has been mostly passive and the in-depth investigation of their basic properties mostly considered from a fundamental perspective.

  20. " The Story of Spin

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 11. The Story of Spin - From Spectroscopy to Relativistic Quantum Mechanics. N Mukunda. Book Review Volume 3 Issue 11 November 1998 pp 89-90. Fulltext. Click here to view fulltext PDF. Permanent link:

  1. Spin and isospin modes

    International Nuclear Information System (INIS)

    Suzuki, T.; Sagawa, H.

    2000-01-01

    Complete text of publication follows. Spin and isospin modes in nuclei are investigated. We discuss some of the following topics. 1. Spin-dipole excitations in 12 C and 16 O are studied (1). Effects of tensor and spin-orbit interactions on the distribution of the strengths are investigated, and neutral current neutrino scattering cross sections in 16 O are obtained for heavy-flavor neutrinos from the supernovae. 2. Gamow-Teller (GT) and spin-dipole (SD) modes in 208 Bi are investigated. Quenching and fragmentation of the GT strength are discussed (2). SD excitations and electric dipole (E1) transitions between the GT and SD states are studied (3). Calculated E1 strengths are compared with the sum rule values obtained within the 1p-1h and 1p-1h + 2p-2h configuration spaces. 3. Coulomb displacement energy (CDE) of the IAS of 14 Be is calculated, and the effects of the halo on the CDE and the configuration of the halo state are investigated. 4. Spreading width of IAS and isospin dependence of the width are investigated (4). Our formula for the width explains very well the observed isospin dependence (5). (author)

  2. On "spinning" membrane models

    NARCIS (Netherlands)

    Bergshoeff, E.; Sezgin, E.; Townsend, P.K.

    1988-01-01

    Several alternative actions for a bosonic membrane have recently been proposed. We show that a linearly realized locally world-volume-supersymmetric (spinning membrane) extension of any of these actions implies an analogous extension of the standard Dirac membrane action. We further show that a

  3. Nuclear spin-off

    International Nuclear Information System (INIS)

    1981-11-01

    This booklet gives examples of 'nuclear spin off', from research programmes carried out for the UKAEA, under the following headings; non destructive testing; tribology; environmental protection; flow measurement; material sciences; mechanical engineering; marine services; biochemical technology; electronic instrumentation. (U.K.)

  4. The invariance of spin

    International Nuclear Information System (INIS)

    Bramson, B.D.

    1978-01-01

    An isolated system in general relativity makes a transition between stationary states. It is shown that the spin vectors of the system, long before and long after the emission of radiation, are supertranslation invariant and, hence, independent of the choice of Minkowski observation space. (author)

  5. High Performance of PEDOT:PSS/n-Si Solar Cells Based on Textured Surface with AgNWs Electrodes

    Science.gov (United States)

    Jiang, Xiangyu; Zhang, Pengbo; Zhang, Juan; Wang, Jilei; Li, Gaofei; Fang, Xiaohong; Yang, Liyou; Chen, Xiaoyuan

    2018-02-01

    Hybrid heterojunction solar cells (HHSCs) have gained extensive research and attention due to simple device structure and low-cost technological processes. Here, HHSCs are presented based on a highly transparent conductive polymer poly(3,4ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS) directly spin-coated on an n-type crystalline silicon with microscale surface textures, which are prepared by traditional chemical etching. We have studied interface properties between PEDOT:PSS and textured n-Si by varying coating conditions. Final power conversion efficiency (PCE) could arrive at 8.54% by these simple solution-based fabrication processes. The high conversion efficiency is attributed to the fully conformal contact between PEDOT:PSS film and textured silicon. Furthermore, the reflectance of the PEDOT:PSS layer on textured surface is analyzed by changing film thickness. In order to improve the performance of the device, silver nanowires were employed as electrodes because of its better optical transmittance and electrical conductivity. The highest PCE of 11.07% was achieved which displayed a 29.6% enhancement compared with traditional silver electrodes. These findings imply that the combination of PEDOT:PSS film and silver nanowire transparent electrodes pave a promising way for realizing high-efficiency and low-cost solar cells.

  6. Spin Injection in Indium Arsenide

    Directory of Open Access Journals (Sweden)

    Mark eJohnson

    2015-08-01

    Full Text Available In a two dimensional electron system (2DES, coherent spin precession of a ballistic spin polarized current, controlled by the Rashba spin orbit interaction, is a remarkable phenomenon that’s been observed only recently. Datta and Das predicted this precession would manifest as an oscillation in the source-drain conductance of the channel in a spin-injected field effect transistor (Spin FET. The indium arsenide single quantum well materials system has proven to be ideal for experimental confirmation. The 2DES carriers have high mobility, low sheet resistance, and high spin orbit interaction. Techniques for electrical injection and detection of spin polarized carriers were developed over the last two decades. Adapting the proposed Spin FET to the Johnson-Silsbee nonlocal geometry was a key to the first experimental demonstration of gate voltage controlled coherent spin precession. More recently, a new technique measured the oscillation as a function of channel length. This article gives an overview of the experimental phenomenology of the spin injection technique. We then review details of the application of the technique to InAs single quantum well (SQW devices. The effective magnetic field associated with Rashba spin-orbit coupling is described, and a heuristic model of coherent spin precession is presented. The two successful empirical demonstrations of the Datta Das conductance oscillation are then described and discussed.

  7. Spin tunnelling in mesoscopic systems

    Indian Academy of Sciences (India)

    Spin tunnelling; spin path integrals; discrete phase integral method; diabolical points. ... technologies. Our purpose in this article is rather different. The molecular systems have total spin of the order of 10, and magnetocrystalline anisotropies of few tens of Kelvin ...... The point С' is of this new type, and here it may be said to.

  8. Spin transport in graphene nanostructures

    NARCIS (Netherlands)

    Guimaraes, M. H. D.; van den Berg, J. J.; Vera-Marun, I. J.; Zomer, P. J.; van Wees, B. J.

    2014-01-01

    Graphene is an interesting material for spintronics, showing long spin relaxation lengths even at room temperature. For future spintronic devices it is important to understand the behavior of the spins and the limitations for spin transport in structures where the dimensions are smaller than the

  9. Spin Transport in Bose Gases

    NARCIS (Netherlands)

    van Driel, H.J.

    2012-01-01

    In this Thesis, we show that in a rotating two-component Bose mixture, the spin drag between the two different spin species shows a Hall effect. This spin drag Hall effect can be observed experimentally by studying the out-of-phase dipole mode of the mixture. We determine the damping of this mode

  10. Spin Transport in Semiconductor heterostructures

    International Nuclear Information System (INIS)

    Marinescu, Domnita Catalina

    2011-01-01

    The focus of the research performed under this grant has been the investigation of spin transport in magnetic semiconductor heterostructures. The interest in these systems is motivated both by their intriguing physical properties, as the physical embodiment of a spin-polarized Fermi liquid, as well as by their potential applications as spintronics devices. In our work we have analyzed several different problems that affect the spin dynamics in single and bi-layer spin-polarized two-dimensional (2D) systems. The topics of interests ranged from the fundamental aspects of the electron-electron interactions, to collective spin and charge density excitations and spin transport in the presence of the spin-orbit coupling. The common denominator of these subjects is the impact at the macroscopic scale of the spin-dependent electron-electron interaction, which plays a much more subtle role than in unpolarized electron systems. Our calculations of several measurable parameters, such as the excitation frequencies of magneto-plasma modes, the spin mass, and the spin transresistivity, propose realistic theoretical estimates of the opposite-spin many-body effects, in particular opposite-spin correlations, that can be directly connected with experimental measurements.

  11. Spinning Them Off: Entrepreneuring Practices in Corporate Spin-Offs

    Directory of Open Access Journals (Sweden)

    Katja Maria Hydle

    2016-01-01

    Full Text Available This paper focuses on the practices between parent and child firms in corporate spinoffs. We uncover the enacted aspects of knowledge, called knowing, through theories from seven cases of incumbent-backed spin-offs and find that the management of the parent firms are highly involved in the spin-offs. The practices associated with spinning off are solving problems, involving multidisciplinary expertise and entrepreneuring management at the parent firm. We contribute to the spin-off literature by discussing the knowledge required for successfully spinning off child firms and to practice theory by empirically uncovering the practical understanding involved in the origin and perpetuation of an organization.

  12. Effects of alkali on protein polymerization and textural characteristics of textured wheat protein.

    Science.gov (United States)

    Li, Ting; Guo, Xiao-Na; Zhu, Ke-Xue; Zhou, Hui-Ming

    2018-01-15

    The impact of alkali addition on the degree of gluten polymerization and textural characteristics of textured wheat protein was investigated. Results showed that the extrusion process increased the average molecular weight of gluten as evidenced by SDS-PAGE and SDS extractable protein. The addition of alkali not only promoted the degree of gluten polymerization, but also induced dehydroalanine-derived cross-linking. Alkali addition decreased the content of cystine and increased the contents of dehydroalanine and lanthionine. The obvious decrease of free SH showed that dehydroalanine-derived cross-linking was quantitatively less crucial than disulfide cross-linking. Furthermore, the protein cross-linking induced by alkali improved the texture properties of gluten extrudates. SEM analysis showed extrusion under alkaline condition conferred a more fibrous microstructure as a consequence of a compact gluten network. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Surface texture modification of spin-coated SiO2 xerogel thin films ...

    Indian Academy of Sciences (India)

    Condensation reaction: Si–OR + HO–Si → Si–O–Si + ROH. (b). Si–OH + HO–Si → Si–O–Si + H2O. (c). (Brinker and Scherrer 1990). The synthesized porous silica films usually are hydrophilic nature which can absorb moisture under the atmospheric con- dition due to the presence of the polar OH radical on the surface that ...

  14. Surface texture modification of spin-coated SiO2 xerogel thin films ...

    Indian Academy of Sciences (India)

    water and alcohol product formed in the hydrolysis reaction. ∗. Author for correspondence (ammahajan@nmu.ac.in; ammahajan.ele@rediffmail.com) get polymerized and form siloxane bonds. The microstruc- ture of the silica film can be easily modified by controlling the sol–gel process parameters. Hydrolysis reaction:.

  15. Pauli Spin Blockade and the Ultrasmall Magnetic Field Effect

    KAUST Repository

    Danon, Jeroen

    2013-08-06

    Based on the spin-blockade model for organic magnetoresistance, we present an analytic expression for the polaron-bipolaron transition rate, taking into account the effective nuclear fields on the two sites. We reveal the physics behind the qualitatively different magnetoconductance line shapes observed in experiment, as well as the ultrasmall magnetic field effect (USFE). Since our findings agree in detail with recent experiments, they also indirectly provide support for the spin-blockade interpretation of organic magnetoresistance. In addition, we predict the existence of a similar USFE in semiconductor double quantum dots tuned to the spin-blockade regime.

  16. The BANANA Survey: Spin-Orbit Alignment in Binary Stars

    Science.gov (United States)

    Albrecht, Simon; Winn, J. N.; Fabrycky, D. C.; Torres, G.; Setiawan, J.

    2012-04-01

    Binaries are not always neatly aligned. Previous observations of the DI Herculis system showed that the spin axes of both stars are highly inclined with respect to one another and the orbital axis. Here, we report on our ongoing survey to measure relative orientations of spin-axes in a number of eclipsing binary systems. These observations will hopefully lead to new insights into star and planet formation, as different formation scenarios predict different degrees of alignment and different dependencies on the system parameters. Measurements of spin-orbit angles in close binary systems will also create a basis for comparison for similar measurements involving close-in planets.

  17. Spin-noise spectroscopy of randomly moving spins in the model of light scattering: Two-beam arrangement

    Science.gov (United States)

    Kozlov, G. G.; Ryzhov, I. I.; Zapasskii, V. S.

    2018-01-01

    A strict analytical solution of the problem of spin-noise signal formation in a volume medium with randomly moving spin carriers is presented. The treatment is carried out in the model of light scattering in a medium with fluctuating inhomogeneity. Along with conventional single-beam geometry, we consider the two-beam arrangement, with the scattering field of the auxiliary (tilted) beam heterodyned on the photodetector illuminated by the main beam. It is shown that the spin-noise signal detected in the two-beam arrangement is highly sensitive to motion (diffusion) of the spin carriers within the illuminated volume and thus can provide additional information about the spin dynamics and spatial correlations of spin polarization in the volume media. Our quantitative estimates show that, under real experimental conditions, spin diffusion may strongly suppress the spin-noise signal in the two-beam geometry. The mechanism of this suppression is similar to that of the time-of-flight broadening with the critical distance determined by the period of two-beam spatial interference rather than by the beam diameter.

  18. Excitation of coherent propagating spin waves by pure spin currents.

    Science.gov (United States)

    Demidov, Vladislav E; Urazhdin, Sergei; Liu, Ronghua; Divinskiy, Boris; Telegin, Andrey; Demokritov, Sergej O

    2016-01-28

    Utilization of pure spin currents not accompanied by the flow of electrical charge provides unprecedented opportunities for the emerging technologies based on the electron's spin degree of freedom, such as spintronics and magnonics. It was recently shown that pure spin currents can be used to excite coherent magnetization dynamics in magnetic nanostructures. However, because of the intrinsic nonlinear self-localization effects, magnetic auto-oscillations in the demonstrated devices were spatially confined, preventing their applications as sources of propagating spin waves in magnonic circuits using these waves as signal carriers. Here, we experimentally demonstrate efficient excitation and directional propagation of coherent spin waves generated by pure spin current. We show that this can be achieved by using the nonlocal spin injection mechanism, which enables flexible design of magnetic nanosystems and allows one to efficiently control their dynamic characteristics.

  19. Spin-wave-induced spin torque in Rashba ferromagnets

    Science.gov (United States)

    Umetsu, Nobuyuki; Miura, Daisuke; Sakuma, Akimasa

    2015-05-01

    We study the effects of Rashba spin-orbit coupling on the spin torque induced by spin waves, which are the plane-wave dynamics of magnetization. The spin torque is derived from linear-response theory, and we calculate the dynamic spin torque by considering the impurity-ladder-sum vertex corrections. This dynamic spin torque is divided into three terms: a damping term, a distortion term, and a correction term for the equation of motion. The distorting torque describes a phenomenon unique to the Rashba spin-orbit coupling system, where the distorted motion of magnetization precession is subjected to the anisotropic force from the Rashba coupling. The oscillation mode of the precession exhibits an elliptical trajectory, and the ellipticity depends on the strength of the nesting effects, which could be reduced by decreasing the electron lifetime.

  20. Experimental Analysis of Grease Friction Properties on Sliding Textured Surfaces

    Directory of Open Access Journals (Sweden)

    Xijun Hua

    2017-10-01

    Full Text Available There is comprehensive work on the tribological properties and lubrication mechanisms of oil lubricant used on textured surfaces, however the use of grease lubrication on textured surfaces is rather new. This research article presents an experimental study of the frictional behaviours of grease lubricated sliding contact under mixed lubrication conditions. The influences of surface texture parameters on the frictional properties were investigated using a disc-on-ring tribometer. The results showed that the friction coefficient is largely dependent on texture parameters, with higher and lower texture density resulting in a higher friction coefficient at a fixed texture depth. The sample with texture density of 15% and texture depth of 19 μm exhibited the best friction properties in all experimental conditions because it can store more grease and trap wear debris. The reduction of friction is mainly attributable to the formation of a stable grease lubrication film composed of oil film, transfer film and deposited film, and the hydrodynamic pressure effect of the surface texture, which increases the mating gap and reduces the probability of asperity contact. This result will help in understanding the tribological behaviour of grease on a textured surface and in predicting the lubrication conditions of sliding bearings for better operation in any machinery.

  1. Forest Classification Based on Forest texture in Northwest Yunnan Province

    Science.gov (United States)

    Wang, Jinliang; Gao, Yan; Wang, Xiaohua; Fu, Lei

    2014-03-01

    Forest texture is an intrinsic characteristic and an important visual feature of a forest ecological system. Full utilization of forest texture will be a great help in increasing the accuracy of forest classification based on remote sensed data. Taking Shangri-La as a study area, forest classification has been based on the texture. The results show that: (1) From the texture abundance, texture boundary, entropy as well as visual interpretation, the combination of Grayscale-gradient co-occurrence matrix and wavelet transformation is much better than either one of both ways of forest texture information extraction; (2) During the forest texture information extraction, the size of the texture-suitable window determined by the semi-variogram method depends on the forest type (evergreen broadleaf forest is 3×3, deciduous broadleaf forest is 5×5, etc.). (3)While classifying forest based on forest texture information, the texture factor assembly differs among forests: Variance Heterogeneity and Correlation should be selected when the window is between 3×3 and 5×5 Mean, Correlation, and Entropy should be used when the window in the range of 7×7 to 19×19 and Correlation, Second Moment, and Variance should be used when the range is larger than 21×21.

  2. Forest Classification Based on Forest texture in Northwest Yunnan Province

    International Nuclear Information System (INIS)

    Wang, Jinliang; Gao, Yan; Fu, Lei; Wang, Xiaohua

    2014-01-01

    Forest texture is an intrinsic characteristic and an important visual feature of a forest ecological system. Full utilization of forest texture will be a great help in increasing the accuracy of forest classification based on remote sensed data. Taking Shangri-La as a study area, forest classification has been based on the texture. The results show that: (1) From the texture abundance, texture boundary, entropy as well as visual interpretation, the combination of Grayscale-gradient co-occurrence matrix and wavelet transformation is much better than either one of both ways of forest texture information extraction; (2) During the forest texture information extraction, the size of the texture-suitable window determined by the semi-variogram method depends on the forest type (evergreen broadleaf forest is 3×3, deciduous broadleaf forest is 5×5, etc.). (3)While classifying forest based on forest texture information, the texture factor assembly differs among forests: Variance Heterogeneity and Correlation should be selected when the window is between 3×3 and 5×5; Mean, Correlation, and Entropy should be used when the window in the range of 7×7 to 19×19; and Correlation, Second Moment, and Variance should be used when the range is larger than 21×21

  3. Use of digital image analysis combined with fractal theory to determine particle morphology and surface texture of quartz sands

    Directory of Open Access Journals (Sweden)

    Georgia S. Araujo

    2017-12-01

    Full Text Available The particle morphology and surface texture play a major role in influencing mechanical and hydraulic behaviors of sandy soils. This paper presents the use of digital image analysis combined with fractal theory as a tool to quantify the particle morphology and surface texture of two types of quartz sands widely used in the region of Vitória, Espírito Santo, southeast of Brazil. The two investigated sands are sampled from different locations. The purpose of this paper is to present a simple, straightforward, reliable and reproducible methodology that can identify representative sandy soil texture parameters. The test results of the soil samples of the two sands separated by sieving into six size fractions are presented and discussed. The main advantages of the adopted methodology are its simplicity, reliability of the results, and relatively low cost. The results show that sands from the coastal spit (BS have a greater degree of roundness and a smoother surface texture than river sands (RS. The values obtained in the test are statistically analyzed, and again it is confirmed that the BS sand has a slightly greater degree of sphericity than that of the RS sand. Moreover, the RS sand with rough surface texture has larger specific surface area values than the similar BS sand, which agree with the obtained roughness fractal dimensions. The consistent experimental results demonstrate that image analysis combined with fractal theory is an accurate and efficient method to quantify the differences in particle morphology and surface texture of quartz sands.

  4. Spin Structures in Magnetic Nanoparticles

    DEFF Research Database (Denmark)

    Mørup, Steen; Brok, Erik; Frandsen, Cathrine

    2013-01-01

    Spin structures in nanoparticles of ferrimagnetic materials may deviate locally in a nontrivial way from ideal collinear spin structures. For instance, magnetic frustration due to the reduced numbers of magnetic neighbors at the particle surface or around defects in the interior can lead to spin...... canting and hence a reduced magnetization. Moreover, relaxation between almost degenerate canted spin states can lead to anomalous temperature dependences of the magnetization at low temperatures. In ensembles of nanoparticles, interparticle exchange interactions can also result in spin reorientation...

  5. Identification and classification of similar looking food grains

    Science.gov (United States)

    Anami, B. S.; Biradar, Sunanda D.; Savakar, D. G.; Kulkarni, P. V.

    2013-01-01

    This paper describes the comparative study of Artificial Neural Network (ANN) and Support Vector Machine (SVM) classifiers by taking a case study of identification and classification of four pairs of similar looking food grains namely, Finger Millet, Mustard, Soyabean, Pigeon Pea, Aniseed, Cumin-seeds, Split Greengram and Split Blackgram. Algorithms are developed to acquire and process color images of these grains samples. The developed algorithms are used to extract 18 colors-Hue Saturation Value (HSV), and 42 wavelet based texture features. Back Propagation Neural Network (BPNN)-based classifier is designed using three feature sets namely color - HSV, wavelet-texture and their combined model. SVM model for color- HSV model is designed for the same set of samples. The classification accuracies ranging from 93% to 96% for color-HSV, ranging from 78% to 94% for wavelet texture model and from 92% to 97% for combined model are obtained for ANN based models. The classification accuracy ranging from 80% to 90% is obtained for color-HSV based SVM model. Training time required for the SVM based model is substantially lesser than ANN for the same set of images.

  6. Issues related to YIG spintronics - thin film growth, spin pumping efficiency, and spin current generation

    Science.gov (United States)

    Wu, Mingzhong

    2014-03-01

    If a magnetic field is applied to a magnetic material, the field produces a torque on the magnetization of the material and drives it to precess. This precession is similar to the motion of a spinning top where the gravitational field produces a torque, instead of the magnetic field. It turns out that magnetization precession in yttrium iron garnets (YIG) decays slower than in any other known magnetic materials. This fact gives rise to the recent birth of a new paradigm in the discipline of spintronics - ``spintronics using YIG.'' This talk will touch on several topics related to YIG spintronics. The first part will demonstrate the feasibility of the use of pulsed laser deposition and magnetron sputtering to grow low-damping, nanometer-thick YIG films. The second part will address the efficiency of spin angular momentum transfer across YIG/normal metal interfaces. The last part will report on the use of YIG thin films to produce pure spin currents; Detailed discussions will be provided on the comparison between spin current generations using traveling spin waves and uniform ferromagnetic resonance modes, the field dependence of spin current generation, and spin current enhancement in YIG/Pt structures via the use of a thin Cu spacer. This work was supported in part by U.S. National Science Foundation (No. ECCS-1231598), the U.S. Army Research Office (No. W911NF-12-1-0518, No. W911NF-11-C-0075), and the U.S. National Institute of Standards and Technology (No. 60NANB10D011).

  7. Evolution of foredune texture following dynamic restoration, Doughboy Bay, Stewart Island, New Zealand

    Science.gov (United States)

    Konlechner, T. M.; Ryu, W.; Hilton, M. J.; Sherman, D. J.

    2015-12-01

    Growing concern regarding the geomorphic and associated biotic effects of dune management practises has led to an increase in the number of dune restoration projects globally. Most recent projects aim to enhance the efficiency of aeolian sediment dynamics and increase dune mobility by decreasing vegetation cover, but we lack objective measures to evaluate such projects. Here we demonstrate the use of landscape metrics to quantify the evolution of foredune texture following the removal of vegetation. A long-term program of marram grass (Ammophila arenaria) eradication in southern New Zealand (Doughboy Bay, Stewart Island) is examined. Four metrics: bare sand area, patch adjacency, complexity, and the range of proximity, are used to classify a series of foredune textures beginning with the pre-restoration state through the phases of marram removal, to the current state. Foredune texture at Doughboy Bay has evolved from a semi-stable to an active state as the consequence of restoration. Two metrics, bare sand and adjacency, appear to be particularly good measures of change following marram removal. Patterns and rates of change for these metrics are consistent with ground observations of increased 'naturalness' (native plant communities, sand mobility) over the same period. The set of landscape metrics derived for Doughboy Bay were compared to similar sets measured for a nearby foredune system where marram invasion has not occurred, and where conditions presumably represent equilibrium foredune texture. Since the removal of marram at Doughboy Bay and the consequent remobilization of the sand surface, the foredune texture has increased in similarity to that of the reference site, indicating a favourable shift in plant cover as a result of the restoration program. We conclude that landscape metrics can be used to track changes in foredune morphology following restoration. Second, the planning, management, and monitoring of coastal dune restoration programs will benefit

  8. Texturing and modeling a procedural approach

    CERN Document Server

    Ebert, David S

    1994-01-01

    Congratulations to Ken Perlin for his 1997 Technical Achievement Award from the Academy of Motion Picture Arts and Science Board of Governors, given in recognition of the development of ""Turbulence"", Perlin Noise, a technique discussed in this book which is used to produce natural appearing textures on computer-generated surfaces for motion picture visual effects. Dr. Perlin joins Darwyn Peachey (co-developer of RenderMan(R), also discussed in the book) in being honored with this prestigious award.* * Written at a usable level by the developers of the techniques* Serves as a source book for

  9. Maya Studio Projects Texturing and Lighting

    CERN Document Server

    Lanier, Lee

    2011-01-01

    Learn to create realistic digital assets for film and games with this project-based guide Focused entirely on practical projects, this hands-on guide shows you how to use Maya's texturing and lighting tools in real-world situations. Whether you need to sharpen your skills or you're looking to break into the field for the first time, you'll learn top industry techniques for this important skill as you follow the instructions for several specific projects. You can even create your own version, using final Maya scene files to validate results. The companion DVD includes supplemental videos, proje

  10. Quantitative texture analysis of electrodeposited line patterns

    DEFF Research Database (Denmark)

    Pantleon, Karen; Somers, Marcel A.J.

    2005-01-01

    Free-standing line patterns of Cu and Ni were manufactured by electrochemical deposition into lithographically prepared patterns. Electrodeposition was carried out on top of a highly oriented Au-layer physically vapor deposited on glass. Quantitative texture analysis carried out by means of x......-ray diffraction for both the substrate layer and the electrodeposits yielded experimental evidence for epitaxy between Cu and Au. An orientation relation between film and substrate was discussed with respect to various concepts of epitaxy. While the conventional mode of epitaxy fails for the Cu...

  11. Graphene spin valve: An angle sensor

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Muhammad Zahir, E-mail: zahir.upc@gmail.com [Faculty of Engineering Sciences, GIK Institute of Engineering Sciences and Technology, Topi 23640, Khyber Pakhtunkhwa (Pakistan); Hussain, Ghulam [Faculty of Engineering Sciences, GIK Institute of Engineering Sciences and Technology, Topi 23640, Khyber Pakhtunkhwa (Pakistan); Siddique, Salma [Department of Bioscience & Biotechnology, Sejong University, Seoul 143-747 (Korea, Republic of); Iqbal, Muhammad Waqas [Department of Physics, Riphah Institute of Computing and Applied Sciences (RICAS), Riphah International University, Lahore (Pakistan)

    2017-06-15

    Graphene spin valves can be optimized for various spintronic applications by tuning the associated experimental parameters. In this work, we report the angle dependent magnetoresistance (MR) in graphene spin valve for different orientations of applied magnetic field (B). The switching points of spin valve signals show a clear shift towards higher B for each increasing angle of the applied field, thus sensing the response for respective orientation of the magnetic field. The angular variation of B shifts the switching points from ±95 G to ±925 G as the angle is varied from 0° to 90° at 300 K. The observed shifts in switching points become more pronounced (±165 G to ±1450 G) at 4.2 K for similar orientation. A monotonic increase in MR ratio is observed as the angle of magnetic field is varied in the vertical direction at 300 K and 4.2 K temperatures. This variation of B (from 0° to 90°) increases the magnitude of MR ratio from ∼0.08% to ∼0.14% at 300 K, while at 4.2 K it progresses to ∼0.39% from ∼0.14%. The sensitivity related to angular variation of such spin valve structure can be employed for angle sensing applications.

  12. Spin-diffusions and diffusive molecular dynamics

    Science.gov (United States)

    Farmer, Brittan; Luskin, Mitchell; Plecháč, Petr; Simpson, Gideon

    2017-12-01

    Metastable configurations in condensed matter typically fluctuate about local energy minima at the femtosecond time scale before transitioning between local minima after nanoseconds or microseconds. This vast scale separation limits the applicability of classical molecular dynamics (MD) methods and has spurned the development of a host of approximate algorithms. One recently proposed method is diffusive MD which aims at integrating a system of ordinary differential equations describing the likelihood of occupancy by one of two species, in the case of a binary alloy, while quasistatically evolving the locations of the atoms. While diffusive MD has shown itself to be efficient and provide agreement with observations, it is fundamentally a model, with unclear connections to classical MD. In this work, we formulate a spin-diffusion stochastic process and show how it can be connected to diffusive MD. The spin-diffusion model couples a classical overdamped Langevin equation to a kinetic Monte Carlo model for exchange amongst the species of a binary alloy. Under suitable assumptions and approximations, spin-diffusion can be shown to lead to diffusive MD type models. The key assumptions and approximations include a well-defined time scale separation, a choice of spin-exchange rates, a low temperature approximation, and a mean field type approximation. We derive several models from different assumptions and show their relationship to diffusive MD. Differences and similarities amongst the models are explored in a simple test problem.

  13. Interlayer quality dependent graphene spin valve

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Muhammad Zahir, E-mail: zahir.upc@gmail.com [Faculty of Engineering Sciences, GIK Institute of Engineering Sciences and Technology, Topi, Khyber Pakhtunkhwa, 23640 Pakistan (Pakistan); Hussain, Ghulam [Faculty of Engineering Sciences, GIK Institute of Engineering Sciences and Technology, Topi, Khyber Pakhtunkhwa, 23640 Pakistan (Pakistan); Siddique, Salma [Department of Bioscience & Biotechnology, Sejong University, Seoul, 143-747 (Korea, Republic of); Iqbal, Muhammad Waqas [Department of Physics, Riphah Institute of Computing and Applied Sciences (RICAS), Riphah International University, Lahore (Pakistan); Murtaza, Ghulam [Centre for Advanced Studies in Physics, Government College University, Lahore 54000 (Pakistan); Ramay, Shahid Mahmood [Physics & Astronomy Department, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia)

    2017-01-15

    It is possible to utilize the new class of materials for emerging two-dimensional (2D) spintronic applications. Here, the role of defects in the graphene interlayer and its influence on the spin valve signal is reported. The emergence of D peak in Raman spectrum reveals defects in the graphene layer. The linear I-V curve for defective and non-defective graphene samples indicate the ohmic nature of NiFe and graphene contact. A non-uniform magnetoresistive effect with a bump is persistently observed for defective graphene device at various temperatures, while a smooth and symmetric signal is detected for non-defective graphene spin valve. Parallel and antiparallel alignments of magnetization of magnetic materials shows low and high resistance states, respectively. The magnetoresistance (MR) ratio for defective graphene NiFe/graphene/NiFe spin valve is measured to be ~0.16% at 300 K which progresses to ~0.39% for non-defective graphene device at the same temperature. Similarly at 4.2 K the MR ratios are reported to be ~0.41% and ~0.78% for defective and non-defective graphene devices, respectively. Our investigation provides an evidence for relatively better response of the spin valve signal with high quality graphene interlayer.

  14. A novel representation of inter-site tumour heterogeneity from pre-treatment computed tomography textures classifies ovarian cancers by clinical outcome

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, Hebert Alberto; Micco, Maura; Lakhman, Yulia; Meier, Andreas A.; Sosa, Ramon; Hricak, Hedvig; Sala, Evis [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States); Veeraraghavan, Harini; Deasy, Joseph [Memorial Sloan Kettering Cancer Center, Department of Medical Physics, New York, NY (United States); Nougaret, Stephanie [Memorial Sloan Kettering Cancer Center, Department of Radiology, New York, NY (United States); Service de Radiologie, Institut Regional du Cancer de Montpellier, Montpellier (France); INSERM, U1194, Institut de Recherche en Cancerologie de Montpellier (IRCM), Montpellier (France); Soslow, Robert A.; Weigelt, Britta [Memorial Sloan Kettering Cancer Center, Department of Pathology, New York, NY (United States); Levine, Douglas A. [Memorial Sloan Kettering Cancer Center, Department of Surgery, New York, NY (United States); Aghajanian, Carol; Snyder, Alexandra [Memorial Sloan Kettering Cancer Center, Department of Medicine, New York, NY (United States)

    2017-09-15

    To evaluate the associations between clinical outcomes and radiomics-derived inter-site spatial heterogeneity metrics across multiple metastatic lesions on CT in patients with high-grade serous ovarian cancer (HGSOC). IRB-approved retrospective study of 38 HGSOC patients. All sites of suspected HGSOC involvement on preoperative CT were manually segmented. Gray-level correlation matrix-based textures were computed from each tumour site, and grouped into five clusters using a Gaussian Mixture Model. Pairwise inter-site similarities were computed, generating an inter-site similarity matrix (ISM). Inter-site texture heterogeneity metrics were computed from the ISM and compared to clinical outcomes. Of the 12 inter-site texture heterogeneity metrics evaluated, those capturing the differences in texture similarities across sites were associated with shorter overall survival (inter-site similarity entropy, similarity level cluster shade, and inter-site similarity level cluster prominence; p ≤ 0.05) and incomplete surgical resection (similarity level cluster shade, inter-site similarity level cluster prominence and inter-site cluster variance; p ≤ 0.05). Neither the total number of disease sites per patient nor the overall tumour volume per patient was associated with overall survival. Amplification of 19q12 involving cyclin E1 gene (CCNE1) predominantly occurred in patients with more heterogeneous inter-site textures. Quantitative metrics non-invasively capturing spatial inter-site heterogeneity may predict outcomes in patients with HGSOC. (orig.)

  15. A novel representation of inter-site tumour heterogeneity from pre-treatment computed tomography textures classifies ovarian cancers by clinical outcome

    International Nuclear Information System (INIS)

    Vargas, Hebert Alberto; Micco, Maura; Lakhman, Yulia; Meier, Andreas A.; Sosa, Ramon; Hricak, Hedvig; Sala, Evis; Veeraraghavan, Harini; Deasy, Joseph; Nougaret, Stephanie; Soslow, Robert A.; Weigelt, Britta; Levine, Douglas A.; Aghajanian, Carol; Snyder, Alexandra

    2017-01-01

    To evaluate the associations between clinical outcomes and radiomics-derived inter-site spatial heterogeneity metrics across multiple metastatic lesions on CT in patients with high-grade serous ovarian cancer (HGSOC). IRB-approved retrospective study of 38 HGSOC patients. All sites of suspected HGSOC involvement on preoperative CT were manually segmented. Gray-level correlation matrix-based textures were computed from each tumour site, and grouped into five clusters using a Gaussian Mixture Model. Pairwise inter-site similarities were computed, generating an inter-site similarity matrix (ISM). Inter-site texture heterogeneity metrics were computed from the ISM and compared to clinical outcomes. Of the 12 inter-site texture heterogeneity metrics evaluated, those capturing the differences in texture similarities across sites were associated with shorter overall survival (inter-site similarity entropy, similarity level cluster shade, and inter-site similarity level cluster prominence; p ≤ 0.05) and incomplete surgical resection (similarity level cluster shade, inter-site similarity level cluster prominence and inter-site cluster variance; p ≤ 0.05). Neither the total number of disease sites per patient nor the overall tumour volume per patient was associated with overall survival. Amplification of 19q12 involving cyclin E1 gene (CCNE1) predominantly occurred in patients with more heterogeneous inter-site textures. Quantitative metrics non-invasively capturing spatial inter-site heterogeneity may predict outcomes in patients with HGSOC. (orig.)

  16. Determination of the spin diffusion length in germanium by spin optical orientation and electrical spin injection

    Science.gov (United States)

    Rinaldi, C.; Bertoli, S.; Asa, M.; Baldrati, L.; Manzoni, C.; Marangoni, M.; Cerullo, G.; Bianchi, M.; Sordan, R.; Bertacco, R.; Cantoni, M.

    2016-10-01

    The measurement of the spin diffusion length and/or lifetime in semiconductors is a key issue for the realisation of spintronic devices, exploiting the spin degree of freedom of carriers for storing and manipulating information. In this paper, we address such parameters in germanium (0 0 1) at room temperature (RT) by three different measurement methods. Exploiting optical spin orientation in the semiconductor and spin filtering across an insulating MgO barrier, the dependence of the resistivity on the spin of photo-excited carriers in Fe/MgO/Ge spin photodiodes (spin-PDs) was electrically detected. A spin diffusion length of 0.9  ±  0.2 µm was obtained by fitting the photon energy dependence of the spin signal by a mathematical model. Electrical techniques, comprising non-local four-terminal and Hanle measurements performed on CoFeB/MgO/Ge lateral devices, led to spin diffusion lengths of 1.3  ±  0.2 µm and 1.3  ±  0.08 µm, respectively. Despite minor differences due to experimental details, the order of magnitude of the spin diffusion length is the same for the three techniques. Although standard electrical methods are the most employed in semiconductor spintronics for spin diffusion length measurements, here we demonstrate optical spin orientation as a viable alternative for the determination of the spin diffusion length in semiconductors allowing for optical spin orientation.

  17. Spin diffusion length of Permalloy using spin absorption in lateral spin valves

    Science.gov (United States)

    Sagasta, Edurne; Omori, Yasutomo; Isasa, Miren; Otani, YoshiChika; Hueso, Luis E.; Casanova, Fèlix

    2017-08-01

    We employ the spin absorption technique in lateral spin valves to extract the spin diffusion length of Permalloy (Py) as a function of temperature and resistivity. A linear dependence of the spin diffusion length with the conductivity of Py is observed, evidencing that the Elliott-Yafet mechanism is the dominant spin relaxation mechanism in Permalloy. Completing the dataset with additional data found in the literature, we obtain λPy = (0.91 ± 0.04) (fΩm2)/ρPy.

  18. Muon spin rotation studies

    Science.gov (United States)

    1984-01-01

    The bulk of the muon spin rotation research work centered around the development of the muon spin rotation facility at the Alternating Gradient Synchrotron (AGS) of Brookhaven National Laboratory (BNL). The collimation system was both designed and fabricated at Virginia State University. This improved collimation system, plus improvements in detectors and electronics enabled the acquisition of spectra free of background out to 15 microseconds. There were two runs at Brookhaven in 1984, one run was devoted primarily to beam development and the other run allowed several successful experiments to be performed. The effect of uniaxial strain on an Fe(Si) crystal at elevated temperature (360K) was measured and the results are incorporated herein. A complete analysis of Fe pulling data taken earlier is included.

  19. Spin and Madelung fluid

    International Nuclear Information System (INIS)

    Salesi, G.

    1995-07-01

    Starting from the Pauli current the decomposition of the non-relativistic local velocity has been obtained in two parts (in the ordinary tensorial language): one parallel and the other orthogonal to the impulse. The former is recognized to be the classical part, that is, the center-of-mass (CM) velocity, and the latter the quantum one, that is, the velocity of the motion in the CM frame (namely, the internal spin motion or Zitterbewegung). Inserting this complete, composite expression of the velocity into the kinetic energy term of the classical non-relativistic (i.e. Newtonian) Lagrangian, the author straightforwardly get the appearance of the so called quantum potential associates as it is known, to the Madelung fluid. In such a way, the quantum mechanical behaviour of particles appears to be strictly correlated to the existence of spin and Zitterbewegung

  20. Biochemical and molecular characterization of Avena indolines and their role in kernel texture.

    Science.gov (United States)

    Gazza, Laura; Taddei, Federica; Conti, Salvatore; Gazzelloni, Gloria; Muccilli, Vera; Janni, Michela; D'Ovidio, Renato; Alfieri, Michela; Redaelli, Rita; Pogna, Norberto E

    2015-02-01

    Among cereals, Avena sativa is characterized by an extremely soft endosperm texture, which leads to some negative agronomic and technological traits. On the basis of the well-known softening effect of puroindolines in wheat kernel texture, in this study, indolines and their encoding genes are investigated in Avena species at different ploidy levels. Three novel 14 kDa proteins, showing a central hydrophobic domain with four tryptophan residues and here named vromindoline (VIN)-1,2 and 3, were identified. Each VIN protein in diploid oat species was found to be synthesized by a single Vin gene whereas, in hexaploid A. sativa, three Vin-1, three Vin-2 and two Vin-3 genes coding for VIN-1, VIN-2 and VIN-3, respectively, were described and assigned to the A, C or D genomes based on similarity to their counterparts in diploid species. Expression of oat vromindoline transgenes in the extra-hard durum wheat led to accumulation of vromindolines in the endosperm and caused an approximate 50 % reduction of grain hardness, suggesting a central role for vromindolines in causing the extra-soft texture of oat grain. Further, hexaploid oats showed three orthologous genes coding for avenoindolines A and B, with five or three tryptophan residues, respectively, but very low amounts of avenoindolines were found in mature kernels. The present results identify a novel protein family affecting cereal kernel texture and would further elucidate the phylogenetic evolution of Avena genus.

  1. The Influence of Tool Texture on Friction and Lubrication in Strip Reduction Testing

    Directory of Open Access Journals (Sweden)

    Mohd Hafis Sulaiman

    2017-01-01

    Full Text Available While texturing of workpiece surfaces to promote lubrication in metal forming has been applied for several decades, tool surface texturing is rather new. In the present paper, tool texturing is studied as a method to prevent galling. A strip reduction test was conducted with tools provided with shallow, longitudinal pockets oriented perpendicular to the sliding direction. The pockets had small angles to the workpiece surface and the distance between them were varied. The experiments reveal that the distance between pockets should be larger than the pocket width, thereby creating a topography similar to flat table mountains to avoid mechanical interlocking in the valleys; otherwise, an increase in drawing load and pick-up on the tools are observed. The textured tool surface lowers friction and improves lubrication performance, provided that the distance between pockets is 2–4 times larger than the pocket width. Larger drawing speed facilitates escape of the entrapped lubricant in the pockets. Testing with low-to-medium viscosity oils leads to a low sheet roughness on the plateaus, but also local workpiece material pick-up on the tool plateaus. Large lubricant viscosity results in higher sheet plateau roughness, but also prevents pick-up and galling.

  2. Molar microwear textures and the diets of Australopithecus anamensis and Australopithecus afarensis.

    Science.gov (United States)

    Ungar, Peter S; Scott, Robert S; Grine, Frederick E; Teaford, Mark F

    2010-10-27

    Many researchers have suggested that Australopithecus anamensis and Australopithecus afarensis were among the earliest hominins to have diets that included hard, brittle items. Here we examine dental microwear textures of these hominins for evidence of this. The molars of three Au. anamensis and 19 Au. afarensis specimens examined preserve unobscured antemortem microwear. Microwear textures of these individuals closely resemble those of Paranthropus boisei, having lower complexity values than Australopithecus africanus and especially Paranthropus robustus. The microwear texture complexity values for Au. anamensis and Au. afarensis are similar to those of the grass-eating Theropithecus gelada and folivorous Alouatta palliata and Trachypithecus cristatus. This implies that these Au. anamensis and Au. afarensis individuals did not have diets dominated by hard, brittle foods shortly before their deaths. On the other hand, microwear texture anisotropy values for these taxa are lower on average than those of Theropithecus, Alouatta or Trachypithecus. This suggests that the fossil taxa did not have diets dominated by tough foods either, or if they did that directions of tooth-tooth movement were less constrained than in higher cusped and sharper crested extant primate grass eaters and folivores.

  3. Numerosity but not texture-density discrimination correlates with math ability in children.

    Science.gov (United States)

    Anobile, Giovanni; Castaldi, Elisa; Turi, Marco; Tinelli, Francesca; Burr, David C

    2016-08-01

    Considerable recent work suggests that mathematical abilities in children correlate with the ability to estimate numerosity. Does math correlate only with numerosity estimation, or also with other similar tasks? We measured discrimination thresholds of school-age (6- to 12.5-years-old) children in 3 tasks: numerosity of patterns of relatively sparse, segregatable items (24 dots); numerosity of very dense textured patterns (250 dots); and discrimination of direction of motion. Thresholds in all tasks improved with age, but at different rates, implying the action of different mechanisms: In particular, in young children, thresholds were lower for sparse than textured patterns (the opposite of adults), suggesting earlier maturation of numerosity mechanisms. Importantly, numerosity thresholds for sparse stimuli correlated strongly with math skills, even after controlling for the influence of age, gender and nonverbal IQ. However, neither motion-direction discrimination nor numerosity discrimination of texture patterns showed a significant correlation with math abilities. These results provide further evidence that numerosity and texture-density are perceived by independent neural mechanisms, which develop at different rates; and importantly, only numerosity mechanisms are related to math. As developmental dyscalculia is characterized by a profound deficit in discriminating numerosity, it is fundamental to understand the mechanism behind the discrimination. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  4. Numerical study of the collapse of a global texture

    Science.gov (United States)

    Barriola, Manuel

    1993-12-01

    We study the numerical solution to the full field equations describing the evolution of a spherically symmetric global texture. We concentrate on the evolution of the fields after the texture collapses. We compare this result with a previous analytical solution found by Turok and Spergel using the nonlinear σ model approximation. The energy produced in massive modes is of the order of 1016 GeV and is almost independent of the initial size of the texture.

  5. Texture development during recrystallization of aluminium containing large particles

    DEFF Research Database (Denmark)

    Juul Jensen, Dorte; Hansen, Niels; Humphreys, F. J.

    1985-01-01

    The recrystallization process in heavily deformed commercially pure aluminium containing large intermetallic particles was studied by in situ neutron diffraction texture measurements and various microscopical techniques including texture measurements in local areas and simultaneous determination...... of orientations takes place close to larger particles or clusters of particles early in the recrystallization process. The texture of fully recrystallized material, however, contains only a relatively weak random component showing that the randomisation effect of the particles was limited. This was ascribed...

  6. Pangaea, She No Spin

    Science.gov (United States)

    McDowell, M.

    2002-12-01

    Looking at lopsided Pangaea, shown imaginatively on many illustrated proposals, I wondered what would happen if the configuration were put in high relief on a globe and spun on axis. Then I wondered if the present configuration of land masses would itself balance as a spinning top. So I got two Replogle globes, two boxes of colored modeling clay sticks, and two fat knitting needles, to fit through the capped holes at the poles of the globes. The clay sticks I cut up into 3 mm. (1/8") slices, using a different color for each continent, and applied to the first globe, assuming the extreme exaggeration above the geoid, no matter how crude, would tell the story. Inserting one needle through the globe and securing it, I balanced the globe on the point of the needle and twirled it like a top. Result: Wobbly! Top end of needle gyrated unevenly, and here it was supposed to make a smooth precessional cone. Oh boy. For the second globe, I used a Scotese "free stuff" interpretation of Pangaea, which I had to augment considerably using USGS, DuToit, Irving and other references, fitting it on the globe and applying identical clay color slices to what I judged generally accepted land surfaces. Result: the thing would hardly stand up, let alone spin. Conclusion: Although a refinement of application on the "today" globe might eliminate nutation, creating a smoother spin, there is no way any refinement of Pangaea on the same size globe can come close. While the concept of a supercontinent may be viable, I theorize that it had to have evolved on a far smaller globe, where land mass could balance, and the "breakup" would not have caused us to wildly gyrate on our axis. Because Pangaea, she no spin.

  7. Spin Hall effect

    Czech Academy of Sciences Publication Activity Database

    Sinova, Jairo; Valenzuela, O.V.; Wunderlich, Joerg; Back, C.H.; Jungwirth, Tomáš

    2015-01-01

    Roč. 87, č. 4 (2015), s. 1213-1259 ISSN 0034-6861 R&D Projects: GA MŠk(CZ) LM2011026; GA ČR GB14-37427G EU Projects: European Commission(XE) 268066 - 0MSPIN Institutional support: RVO:68378271 Keywords : spin Hall effect * spintronics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 33.177, year: 2015

  8. Spin and gravitation

    Science.gov (United States)

    Ray, J. R.

    1982-01-01

    The fundamental variational principle for a perfect fluid in general relativity is extended so that it applies to the metric-torsion Einstein-Cartan theory. Field equations for a perfect fluid in the Einstein-Cartan theory are deduced. In addition, the equations of motion for a fluid with intrinsic spin in general relativity are deduced from a special relativistic variational principle. The theory is a direct extension of the theory of nonspinning fluids in special relativity.

  9. Spinning Disk Confocal System

    Science.gov (United States)

    2006-06-01

    high temporal resolution. An instrument has been developed for exactly this type of live-cell imaging. This new instrument scans 1000 microbeams across...Imaging System. Instead of scanning a single laser beam across the cell, this new instrument scans 1000 microbeams simultaneously using a spinning...multipoint-excitation, multipoint- emission characteristics of UltraView RS, which confers three main advantages over traditional beam scanning LSCMs for

  10. Three-electron spin qubits

    Science.gov (United States)

    Russ, Maximilian; Burkard, Guido

    2017-10-01

    The goal of this article is to review the progress of three-electron spin qubits from their inception to the state of the art. We direct the main focus towards the exchange-only qubit (Bacon et al 2000 Phys. Rev. Lett. 85 1758-61, DiVincenzo et al 2000 Nature 408 339) and its derived versions, e.g. the resonant exchange (RX) qubit, but we also discuss other qubit implementations using three electron spins. For each three-spin qubit we describe the qubit model, the envisioned physical realization, the implementations of single-qubit operations, as well as the read-out and initialization schemes. Two-qubit gates and decoherence properties are discussed for the RX qubit and the exchange-only qubit, thereby completing the list of requirements for quantum computation for a viable candidate qubit implementation. We start by describing the full system of three electrons in a triple quantum dot, then discuss the charge-stability diagram, restricting ourselves to the relevant subsystem, introduce the qubit states, and discuss important transitions to other charge states (Russ et al 2016 Phys. Rev. B 94 165411). Introducing the various qubit implementations, we begin with the exchange-only qubit (DiVincenzo et al 2000 Nature 408 339, Laird et al 2010 Phys. Rev. B 82 075403), followed by the RX qubit (Medford et al 2013 Phys. Rev. Lett. 111 050501, Taylor et al 2013 Phys. Rev. Lett. 111 050502), the spin-charge qubit (Kyriakidis and Burkard 2007 Phys. Rev. B 75 115324), and the hybrid qubit (Shi et al 2012 Phys. Rev. Lett. 108 140503, Koh et al 2012 Phys. Rev. Lett. 109 250503, Cao et al 2016 Phys. Rev. Lett. 116 086801, Thorgrimsson et al 2016 arXiv:1611.04945). The main focus will be on the exchange-only qubit and its modification, the RX qubit, whose single-qubit operations are realized by driving the qubit at its resonant frequency in the microwave range similar to electron spin resonance. Two different types of two-qubit operations are presented for the exchange

  11. Texture classification by texton: statistical versus binary.

    Directory of Open Access Journals (Sweden)

    Zhenhua Guo

    Full Text Available Using statistical textons for texture classification has shown great success recently. The maximal response 8 (Statistical_MR8, image patch (Statistical_Joint and locally invariant fractal (Statistical_Fractal are typical statistical texton algorithms and state-of-the-art texture classification methods. However, there are two limitations when using these methods. First, it needs a training stage to build a texton library, thus the recognition accuracy will be highly depended on the training samples; second, during feature extraction, local feature is assigned to a texton by searching for the nearest texton in the whole library, which is time consuming when the library size is big and the dimension of feature is high. To address the above two issues, in this paper, three binary texton counterpart methods were proposed, Binary_MR8, Binary_Joint, and Binary_Fractal. These methods do not require any training step but encode local feature into binary representation directly. The experimental results on the CUReT, UIUC and KTH-TIPS databases show that binary texton could get sound results with fast feature extraction, especially when the image size is not big and the quality of image is not poor.

  12. Surface texture measurement for additive manufacturing

    International Nuclear Information System (INIS)

    Triantaphyllou, Andrew; Tomita, Ben; Milne, Katherine A; Giusca, Claudiu L; Macaulay, Gavin D; Roerig, Felix; Hoebel, Matthias; Leach, Richard K

    2015-01-01

    The surface texture of additively manufactured metallic surfaces made by powder bed methods is affected by a number of factors, including the powder’s particle size distribution, the effect of the heat source, the thickness of the printed layers, the angle of the surface relative to the horizontal build bed and the effect of any post processing/finishing. The aim of the research reported here is to understand the way these surfaces should be measured in order to characterise them. In published research to date, the surface texture is generally reported as an Ra value, measured across the lay. The appropriateness of this method for such surfaces is investigated here. A preliminary investigation was carried out on two additive manufacturing processes—selective laser melting (SLM) and electron beam melting (EBM)—focusing on the effect of build angle and post processing. The surfaces were measured using both tactile and optical methods and a range of profile and areal parameters were reported. Test coupons were manufactured at four angles relative to the horizontal plane of the powder bed using both SLM and EBM. The effect of lay—caused by the layered nature of the manufacturing process—was investigated, as was the required sample area for optical measurements. The surfaces were also measured before and after grit blasting. (paper)

  13. Dynamic air layer on textured superhydrophobic surfaces

    KAUST Repository

    Vakarelski, Ivan Uriev

    2013-09-03

    We provide an experimental demonstration that a novel macroscopic, dynamic continuous air layer or plastron can be sustained indefinitely on textured superhydrophobic surfaces in air-supersaturated water by a natural gas influx mechanism. This type of plastron is an intermediate state between Leidenfrost vapor layers on superheated surfaces and the equilibrium Cassie-Baxter wetting state on textured superhydrophobic surfaces. We show that such a plastron can be sustained on the surface of a centimeter-sized superhydrophobic sphere immersed in heated water and variations of its dynamic behavior with air saturation of the water can be regulated by rapid changes of the water temperature. The simple experimental setup allows for quantification of the air flux into the plastron and identification of the air transport model of the plastron growth. Both the observed growth dynamics of such plastrons and millimeter-sized air bubbles seeded on the hydrophilic surface under identical air-supersaturated solution conditions are consistent with the predictions of a well-mixed gas transport model. © 2013 American Chemical Society.

  14. Three-dimensional magnetic spin-echo small-angle neutron scattering and neutron depolarization: A comparison

    International Nuclear Information System (INIS)

    Rekveldt, M. Theo; Dijk, Niels H. van; Grigoriev, Serguei V.; Kraan, Wicher H.; Bouwman, Wim G.

    2006-01-01

    The recently developed magnetic spin-echo small-angle neutron scattering (SANS) technique provides unique information about the distance correlation of the local vector magnetization as a function of the spin-echo length within a magnetic material. The technique probes the magnetic correlations on a length scale from 10 nm up to 10 μm within the bulk of a magnetic material by evaluating the Larmor precession of a polarized neutron beam in a spin-echo setup. The characteristics of the spin-echo SANS technique are discussed and compared to those of the more conventional neutron depolarization technique. Both of these techniques probe the average size of the magnetic inhomogeneities and the local magnetic texture. The magnetic spin-echo SANS technique gives information on the size distribution of these magnetic inhomogeneities perpendicular to the beam and, in principle, independent on the local magnetic induction. This information is not accessible by the neutron depolarization technique that gives the average size parallel to the beam multiplied with the square of the local magnetic induction. The basic possibilities of the magnetic spin-echo SANS technique are demonstrated by experiments on samples with a strong magnetic texture

  15. Spinning geometry = Twisted geometry

    International Nuclear Information System (INIS)

    Freidel, Laurent; Ziprick, Jonathan

    2014-01-01

    It is well known that the SU(2)-gauge invariant phase space of loop gravity can be represented in terms of twisted geometries. These are piecewise-linear-flat geometries obtained by gluing together polyhedra, but the resulting geometries are not continuous across the faces. Here we show that this phase space can also be represented by continuous, piecewise-flat three-geometries called spinning geometries. These are composed of metric-flat three-cells glued together consistently. The geometry of each cell and the manner in which they are glued is compatible with the choice of fluxes and holonomies. We first remark that the fluxes provide each edge with an angular momentum. By studying the piecewise-flat geometries which minimize edge lengths, we show that these angular momenta can be literally interpreted as the spin of the edges: the geometries of all edges are necessarily helices. We also show that the compatibility of the gluing maps with the holonomy data results in the same conclusion. This shows that a spinning geometry represents a way to glue together the three-cells of a twisted geometry to form a continuous geometry which represents a point in the loop gravity phase space. (paper)

  16. Spin Foam Models

    CERN Document Server

    Krasnov, K V

    1999-01-01

    The term ‘spin foam models’ was invented only a couple years ago by Baez to refer to a new approach to quantization of general relativity that appeared as an offsping of loop quantum gravity. Although this new approach was motivated, both logically and historically, by loop quantum gravity, it became clear by now that the two approaches are rather independent. While loop quantum gravity attempts to give a canonical quantization of general relativity, spin foam model approach is set to make sense of the path integral for gravity. Eventually, the two approaches will probably be shown to be equivalent, but no rigorous result to this effect exists as for now. In this thesis I develop the spin foam quantization of gravity from scratch, referring to results from loop quantum gravity only for comparison. I start from a review of 2 + 1 gravity and discuss different roots to quantize it. While some of them, as, for example, using Chern-Simons theory, only exist in 2 + 1, others can be generalized t...

  17. Shape-Tailored Features and their Application to Texture Segmentation

    KAUST Repository

    Khan, Naeemullah

    2014-04-01

    Texture Segmentation is one of the most challenging areas of computer vision. One reason for this difficulty is the huge variety and variability of textures occurring in real world, making it very difficult to quantitatively study textures. One of the key tools used for texture segmentation is local invariant descriptors. Texture consists of textons, the basic building block of textures, that may vary by small nuisances like illumination variation, deformations, and noise. Local invariant descriptors are robust to these nuisances making them beneficial for texture segmentation. However, grouping dense descriptors directly for segmentation presents a problem: existing descriptors aggregate data from neighborhoods that may contain different textured regions, making descriptors from these neighborhoods difficult to group, leading to significant errors in segmentation. This work addresses this issue by proposing dense local descriptors, called Shape-Tailored Features, which are tailored to an arbitrarily shaped region, aggregating data only within the region of interest. Since the segmentation, i.e., the regions, are not known a-priori, we propose a joint problem for Shape-Tailored Features and the regions. We present a framework based on variational methods. Extensive experiments on a new large texture dataset, which we introduce, show that the joint approach with Shape-Tailored Features leads to better segmentations over the non-joint non Shape-Tailored approach, and the method out-performs existing state-of-the-art.

  18. The Example of Texture Influence in Stress Analysis

    CERN Document Server

    Lychagina, T A

    2002-01-01

    Influence of texture on the stress-strain curves experimentally measured in the elastic region by neutron diffraction of an extruded Cu rod is shown. Texture information is obtained from the pole figures measured by neutron diffraction as well. Stress-strain curves are computed with elastic polycrystalline properties calculated with and without taking texture into account. Calculations of elastic polycrystalline properties with texture are carried out according to geometric mean model. The advantage of geometric mean averaging recently developed for diffraction elastic constant calculation is experimentally confirmed.

  19. Chemical composition and temperature influence on honey texture properties.

    Science.gov (United States)

    Oroian, Mircea; Paduret, Sergiu; Amariei, Sonia; Gutt, Gheorghe

    2016-01-01

    The aim of this study is to evaluate the chemical composition and temperatures (20, 30, 40, 50 and 60 °C) influence on the honey texture parameters (hardness, viscosity, adhesion, cohesiveness, springiness, gumminess and chewiness). The honeys analyzed respect the European regulation in terms of moisture content and inverted sugar concentration. The texture parameters are influenced negatively by the moisture content, and positively by the °Brix concentration. The texture parameters modelling have been made using the artificial neural network and the polynomial model. The polynomial model predicted better the texture parameters than the artificial neural network.

  20. Extreme Compression and Modeling of Bidirectional Texture Function

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Filip, Jiří

    2007-01-01

    Roč. 29, č. 10 (2007), s. 1859-1865 ISSN 0162-8828 R&D Projects: GA AV ČR 1ET400750407; GA MŠk 1M0572; GA AV ČR IAA2075302 EU Projects: European Commission(XE) 507752 - MUSCLE Grant - others:GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : Rough texture * 3D texture * BTF * texture synthesis * texture modeling * data compression Subject RIV: BD - Theory of Information Impact factor: 3.579, year: 2007 http://doi.ieeecomputersociety.org/10.1109/TPAMI.2007.1139

  1. Magnetic Snell's law and spin-wave fiber with Dzyaloshinskii-Moriya interaction

    Science.gov (United States)

    Yu, Weichao; Lan, Jin; Wu, Ruqian; Xiao, Jiang

    2016-10-01

    Spin waves are collective excitations propagating in the magnetic medium with ordered magnetizations. Magnonics, utilizing the spin wave (magnon) as an information carrier, is a promising candidate for low-dissipation computation and communication technologies. We discover that, due to the Dzyaloshinskii-Moriya interaction, the scattering behavior of the spin wave at a magnetic domain wall follows a generalized Snell's law, where two magnetic domains work as two different mediums. Similar to optical total reflection that occurs at water-air interfaces, spin waves may experience total reflection at the magnetic domain walls when their incident angle is larger than a critical value. We design a spin-wave fiber using a magnetic domain structure with two domain walls, and demonstrate that such a spin-wave fiber can transmit spin waves over long distances by total internal reflections, in analogy to an optical fiber.

  2. Frustrated spin-1/2 ladder with ferro- and antiferromagnetic legs

    Science.gov (United States)

    Maiti, Debasmita; Dey, Dayasindhu; Kumar, Manoranjan

    2018-01-01

    Two-leg spin-1/2 ladder systems consisting of a ferromagnetic leg and an antiferromagnetic leg are considered where the spins on the legs interact through antiferromagnetic rung couplings J1 . These ladders can have two geometrical arrangements either zigzag or normal ladder and these systems are frustrated irrespective of their geometry. This frustration gives rise to incommensurate spin density wave, dimer and spin fluid phases in the ground state. The magnetization in the systems decreases linearly with J12, and the systems show an incommensurate phase for 0.0 spin-spin correlation functions in the incommensurate phase follow power law decay which is very similar to Heisenberg antiferromagnetic chain in external magnetic field. In large J1 limit, the normal ladder behaves like a collection of singlet dimers, whereas the zigzag ladder behaves as a one dimensional spin-1/2 antiferromagnetic chain.

  3. Spinning particle approach to higher spin field theory

    International Nuclear Information System (INIS)

    Corradini, Olindo

    2011-01-01

    We shortly review on the connection between higher-spin gauge field theories and supersymmetric spinning particle models. In such approach the higher spin equations of motion are linked to the first-class constraint algebra associated with the quantization of particle models. Here we consider a class of spinning particle models characterized by local O(N)-extended supersymmetry since these models are known to provide an alternative approach to the geometric formulation of higher spin field theory. We describe the canonical quantization of the models in curved target space and discuss the obstructions that appear in presence of an arbitrarily curved background. We then point out the special role that conformally flat spaces appear to have in such models and present a derivation of the higher-spin curvatures for maximally symmetric spaces.

  4. Entanglement entropy in random quantum spin-S chains

    International Nuclear Information System (INIS)

    Saguia, A.; Boechat, B.; Continentino, M. A.; Sarandy, M. S.

    2007-01-01

    We discuss the scaling of entanglement entropy in the random singlet phase (RSP) of disordered quantum magnetic chains of general spin S. Through an analysis of the general structure of the RSP, we show that the entanglement entropy scales logarithmically with the size of a block, and we provide a closed expression for this scaling. This result is applicable for arbitrary quantum spin chains in the RSP, being dependent only on the magnitude S of the spin. Remarkably, the logarithmic scaling holds for the disordered chain even if the pure chain with no disorder does not exhibit conformal invariance, as is the case for Heisenberg integer-spin chains. Our conclusions are supported by explicit evaluations of the entanglement entropy for random spin-1 and spin-3/2 chains using an asymptotically exact real-space renormalization group approach

  5. Spin current through quantum-dot spin valves

    International Nuclear Information System (INIS)

    Wang, J; Xing, D Y

    2006-01-01

    We report a theoretical study of the influence of the Coulomb interaction on the equilibrium spin current in a quantum-dot spin valve, in which the quantum dot described by the Anderson impurity model is coupled to two ferromagnetic leads with noncollinear magnetizations. In the Kondo regime, electrons transmit through the quantum dot via higher-order virtual processes, in which the spin of either lead electrons or a localized electron on the quantum dot may reverse. It is found that the magnitude of the spin current decreases with increasing Coulomb interactions due to spin flip effects on the dot. However, the spatial direction of the spin current remains unchanged; it is determined only by the exchange coupling between two noncollinear magnetizations

  6. Spin-polarized current and shot noise in the presence of spin flip in a quantum dot via nonequilibrium Green's functions

    DEFF Research Database (Denmark)

    De Souza, Fabricio; Jauho, Antti-Pekka; Egues, J.C.

    2008-01-01

    Using nonequilibrium Green's functions we calculate the spin-polarized current and shot noise in a ferromagnet-quantum-dot-ferromagnet system. Both parallel (P) and antiparallel (AP) magnetic configurations are considered. Coulomb interaction and coherent spin flip (similar to a transverse magnet...

  7. Similarity measures for protein ensembles

    DEFF Research Database (Denmark)

    Lindorff-Larsen, Kresten; Ferkinghoff-Borg, Jesper

    2009-01-01

    Analyses of similarities and changes in protein conformation can provide important information regarding protein function and evolution. Many scores, including the commonly used root mean square deviation, have therefore been developed to quantify the similarities of different protein conformatio...

  8. Similarity measures for protein ensembles

    DEFF Research Database (Denmark)

    Lindorff-Larsen, Kresten; Ferkinghoff-Borg, Jesper

    2009-01-01

    Analyses of similarities and changes in protein conformation can provide important information regarding protein function and evolution. Many scores, including the commonly used root mean square deviation, have therefore been developed to quantify the similarities of different protein conformations...

  9. Spin Transfer Torque in Graphene

    Science.gov (United States)

    Lin, Chia-Ching; Chen, Zhihong

    2014-03-01

    Graphene is an idea channel material for spin transport due to its long spin diffusion length. To develop graphene based spin logic, it is important to demonstrate spin transfer torque in graphene. Here, we report the experimental measurement of spin transfer torque in graphene nonlocal spin valve devices. Assisted by a small external in-plane magnetic field, the magnetization reversal of the receiving magnet is induced by pure spin diffusion currents from the injector magnet. The magnetization switching is reversible between parallel and antiparallel configurations by controlling the polarity of the applied charged currents. Current induced heating and Oersted field from the nonlocal charge flow have also been excluded in this study. Next, we further enhance the spin angular momentum absorption at the interface of the receiving magnet and graphene channel by removing the tunneling barrier in the receiving magnet. The device with a tunneling barrier only at the injector magnet shows a comparable nonlocal spin valve signal but lower electrical noise. Moreover, in the same preset condition, the critical charge current density for spin torque in the single tunneling barrier device shows a substantial reduction if compared to the double tunneling barrier device.

  10. Similar Hamiltonian Between Avalanche-effect & Sociophysics

    Science.gov (United States)

    Maksoed, Ssi, Wh-

    2016-05-01

    Of similar Hamiltonian concerned in ``sociophysics'', there were RandomFieldIsingModel/RFIM in external field retrieved in S. Sabhapandit:``Hysteresis & Avalanche in RandomFieldIsingModel'',2002:'' ..in earthquake, it is an energy release and in case of ferromagnet, it is the size of the domain flips''. Following the extremes & compromises curve in Serge Galam: ``Sociophysics: a Review of Galam Model'', 2008 fig. 12, h 9 whereas it seems similar with ``heating curve''-Prof. Ir. Abdul Kadir: ``Mesin Arus Searah'', h 192 when the heat sources are continuous denote continuous opinion dynamics. Further, hysteresis as duties in ``Kajian Analisis Model Mikromagnetik dari Struktur Magnet Nanokomposit'', 2007 [ UI file no. S29286 ] also sought:'' calculate the probability that `one more site became unstable' causes an avalanche of the spin flips...'' usually found in Per Bak sand-pile fractal characters experiment exhibits. Great acknowledgment to HE. Mr. LieutGen-TNI[rtd]. H. TUK SETYOHADI, +62-21-7220385, Jl. Sriwijaya Raya 3, Kebayoran Baru, South-Jakarta.

  11. Spin waves and spin instabilities in quantum plasmas

    OpenAIRE

    Andreev, P. A.; Kuz'menkov, L. S.

    2014-01-01

    We describe main ideas of method of many-particle quantum hydrodynamics allows to derive equations for description of quantum plasma evolution. We also present definitions of collective quantum variables suitable for quantum plasmas. We show that evolution of magnetic moments (spins) in quantum plasmas leads to several new branches of wave dispersion: spin-electromagnetic plasma waves and self-consistent spin waves. Propagation of neutron beams through quantum plasmas is also considered. Inst...

  12. Hardy's argument and successive spin-s measurements

    International Nuclear Information System (INIS)

    Ahanj, Ali

    2010-01-01

    We consider a hidden-variable theoretic description of successive measurements of noncommuting spin observables on an input spin-s state. In this scenario, the hidden-variable theory leads to a Hardy-type argument that quantum predictions violate it. We show that the maximum probability of success of Hardy's argument in quantum theory is ((1/2)) 4s , which is more than in the spatial case.

  13. Breakdown of Spin-Waves in Anisotropic Magnets: Spin Dynamics in α-RuCl3

    Science.gov (United States)

    Winter, Stephen; Riedl, Kira; Honecker, Andreas; Valenti, Roser

    α -RuCl3 has recently emerged as a promising candidate for realizing the hexagonal Kitaev model in a real material. Similar to the related iridates (e.g. Na2IrO3), complex magnetic interactions arise from a competition between various similar energy scales, including spin-orbit coupling (SOC), Hund's coupling, and crystal-field splitting. Due to this complexity, the correct spin Hamiltonians for such systems remain hotly debated. For α-RuCl3, a combination of ab-initio calculations, microscopic considerations, and analysis of the static magnetic response have suggested off-diagonal couplings (Γ ,Γ') and long-range interactions in addition to the expected Kitaev exchange. However, the effect of such additional terms on the dynamic response remains unclear. In this contribution, we discuss the recently measured inelastic neutron scattering response in the context of realistic proposals for the microscopic spin Hamiltonian. We conclude that the observed scattering continuum, which has been taken as a signature of Kitaev spin liquid physics, likely persists over a broad range of parameters.

  14. On field theory for 1 and 3/2 spin

    International Nuclear Information System (INIS)

    Spehler, D.

    1979-01-01

    Bargmann-Wigner's theory is employed in studying fields with spin 1 and 3/2. It is shown that in the case of spin 1 this theory is equivalent to Proca's theory. Using the commutation relations for Proca's vector field it is possible to deduce similar relations for Bargmann-Wigner's field with spin 1. In the case of spin 3/2, a Lagrangian can be written only with auxiliary fields or in Rarita-Schwinger's form. Undorial equations like the Pauli-Fierz ones, are obtained from Bargmann-Wigner's equations employing a chirality operator. Projection operators for positive and negative energy are also obtained. A detailed study of the solutions of Bargmann-Wigner's equations for spin 1 and 3/2 is performed. The form of the matrix elements for the E.M.G. current of a particle with spin 3/2 is deduced. This is employed in the study of the E.M.G. interactions of this particle. Finally the general commutation rules for a Bargmann-Wigner field with arbitrary spin are given [fr

  15. Current-induced torques and interfacial spin-orbit coupling

    KAUST Repository

    Haney, Paul M.

    2013-12-19

    In bilayer systems consisting of an ultrathin ferromagnetic layer adjacent to a metal with strong spin-orbit coupling, an applied in-plane current induces torques on the magnetization. The torques that arise from spin-orbit coupling are of particular interest. Here we use first-principles methods to calculate the current-induced torque in a Pt-Co bilayer to help determine the underlying mechanism. We focus exclusively on the analog to the Rashba torque, and do not consider the spin Hall effect. The details of the torque depend strongly on the layer thicknesses and the interface structure, providing an explanation for the wide variation in results found by different groups. The torque depends on the magnetization direction in a way similar to that found for a simple Rashba model. Artificially turning off the exchange spin splitting and separately the spin-orbit coupling potential in the Pt shows that the primary source of the “fieldlike” torque is a proximate spin-orbit effect on the Co layer induced by the strong spin-orbit coupling in the Pt.

  16. Chiral higher spin theories and self-duality

    Science.gov (United States)

    Ponomarev, Dmitry

    2017-12-01

    We study recently proposed chiral higher spin theories — cubic theories of interacting massless higher spin fields in four-dimensional flat space. We show that they are naturally associated with gauge algebras, which manifest themselves in several related ways. Firstly, the chiral higher spin equations of motion can be reformulated as the self-dual Yang-Mills equations with the associated gauge algebras instead of the usual colour gauge algebra. We also demonstrate that the chiral higher spin field equations, similarly to the self-dual Yang-Mills equations, feature an infinite algebra of hidden symmetries, which ensures their integrability. Secondly, we show that off-shell amplitudes in chiral higher spin theories satisfy the generalised BCJ relations with the usual colour structure constants replaced by the structure constants of higher spin gauge algebras. We also propose generalised double copy procedures featuring higher spin theory amplitudes. Finally, using the light-cone deformation procedure we prove that the structure of the Lagrangian that leads to all these properties is universal and follows from Lorentz invariance.

  17. Regenerated collagen fibers with grooved surface texture: Physicochemical characterization and cytocompatibility.

    Science.gov (United States)

    Wang, Xiang; Wu, Tong; Wang, Wei; Huang, Chen; Jin, Xiangyu

    2016-01-01

    A novel type of protein fibers, regenerated collagen fibers (RC) from cattle skin, was prepared through wet-spinning. Due to the combined effect of solvent exchange and subsequent drawing process, the fibers were found to have a grooved surface texture. The grooves provided not only ordered topographical cues, but also increased surface area. Protein content of the RC fibers was confirmed by Fourier Transform infrared spectroscopy (FTIR) and ninhydrin color reaction. The fibers could be readily fabricated into nonwovens or other textiles, owning to their comparable physical properties to other commercialized fibers. Cell growth behavior on RC nonwovens suggested both early adhesion and prompt proliferation. The high moisture regain, good processability, along with the excellent cytocompatibility indicated that the RC fibers and nonwovens developed in this study might offer a good candidate for biomedical and healthcare applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Spin transport in spin filtering magnetic tunneling junctions.

    Science.gov (United States)

    Li, Yun; Lee, Eok Kyun

    2007-11-01

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

  19. Spin-orbit mediated control of spin qubits

    DEFF Research Database (Denmark)

    Flindt, Christian; Sørensen, A.S; Flensberg, Karsten

    2006-01-01

    We propose to use the spin-orbit interaction as a means to control electron spins in quantum dots, enabling both single-qubit and two-qubit operations. Very fast single-qubit operations may be achieved by temporarily displacing the electrons. For two-qubit operations the coupling mechanism is based...... on a combination of the spin-orbit coupling and the mutual long-ranged Coulomb interaction. Compared to existing schemes using the exchange coupling, the spin-orbit induced coupling is less sensitive to random electrical fluctuations in the electrodes defining the quantum dots....

  20. High-field spin dynamics of antiferromagnetic quantum spin chains

    DEFF Research Database (Denmark)

    Enderle, M.; Regnault, L.P.; Broholm, C.

    2000-01-01

    present recent work on the high-field spin dynamics of the S = I antiferromagnetic Heisenberg chains NENP (Haldane ground state) and CsNiCl3 (quasi-1D HAF close to the quantum critical point), the uniform S = 1/2 chain CTS, and the spin-Peierls system CuGeO3. (C) 2000 Elsevier Science B,V. All rights......The characteristic internal order of macroscopic quantum ground states in one-dimensional spin systems is usually not directly accessible, but reflected in the spin dynamics and the field dependence of the magnetic excitations. In high magnetic fields quantum phase transitions are expected. We...