Sample records for magnetic-field-induced quadrupolar ordering

  1. Magnetic field induced switching of the antiferromagnetic order parameter in thin films of magnetoelectric chromia

    NASA Astrophysics Data System (ADS)

    Fallarino, Lorenzo; Berger, Andreas; Binek, Christian

    2015-02-01

    A Landau-theoretical approach is utilized to model the magnetic field induced reversal of the antiferromagnetic order parameter in thin films of magnetoelectric antiferromagnets. A key ingredient of this peculiar switching phenomenon is the presence of a robust spin polarized state at the surface of the antiferromagnetic films. Surface or boundary magnetization is symmetry allowed in magnetoelectric antiferromagnets and experimentally established for chromia thin films. It couples rigidly to the antiferromagnetic order parameter and its Zeeman energy creates a pathway to switch the antiferromagnet via magnetic field application. In the framework of a minimalist Landau free energy expansion, the temperature dependence of the switching field and the field dependence of the transition width are derived. Least-squares fits to magnetometry data of (0001 ) textured chromia thin films strongly support this model of the magnetic reversal mechanism.

  2. Magnetic-field-induced orientational order in the isotropic phase of hard colloidal platelets

    SciTech Connect

    Beek, D. van der; Petukhov, A.V.; Vroege, G.J.; Lekkerkerker, H.N.W. [Van't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute, Utrecht University, Padualaan 8, 3584 CH Utrecht (Netherlands); Davidson, P.; Ferre, J.; Jamet, J.P. [Laboratoire de Physique des Solides, UMR 8502 CNRS, Universite Paris-Sud, Batiment 510, 91405 Orsay (France); Wensink, H.H. [Institut fuer Theoretische Physik II, Heinrich-Heine-Universitaet Duesseldorf, Universitaetsstrasse 1, Gebaeude 25.32, 40225 Duesseldorf (Germany); Bras, W. [Netherlands Organisation for Scientific Research (NWO), DUBBLE CRG, European Synchrotron Radiation Facility, BP 220, 38043 Grenoble Cedex (France)

    2006-04-15

    The magnetic-field-induced orientational order in the isotropic phase of colloidal gibbsite [Al(OH){sub 3}] platelets is studied by means of optical birefringence and small-angle x-ray scattering (SAXS) techniques. The suspensions display field-induced ordering at moderate field strengths (a few Tesla), which increases with increasing particle concentration. The gibbsite particles align their normals perpendicular to the magnetic field and hence possess a negative anisotropy of their diamagnetic susceptibility {delta}{chi}. The results can be described following a simple, Onsager-like approach. A simplified model is derived that allows one to obtain the orientational distribution function directly from the scattering data. However, it leads to an underestimate of the diamagnetic susceptibility anisotropy {delta}{chi}. This accounts for the difference between the {delta}{chi} values provided by the two experimental techniques (SAXS and magneto-optics). The order of magnitude {delta}{chi}{approx}10{sup -22} J/T{sup 2} lies in between that of goethite suspensions and that of suspensions of organic particles.

  3. Giant magnetic field-induced strain due to rearrangement of variants in an ordered Fe 3Pt

    Microsoft Academic Search

    Tatsuaki Sakamoto; Takashi Fukuda; Tomoyuki Kakeshita; Tetsuya Takeuchi; Kohji Kishio

    2004-01-01

    Magnetic field-induced strain due to rearrangement of martensite variants in a ferromagnetic Fe3Pt alloy single crystal with degree of order of about 0.8 has been investigated. The alloy exhibits a martensitic transformation from an ordered L12-type structure to a tetragonal one at 85 K. The tetragonality of the martensite decreases as temperature decreases, and is about 0.945 at 14 K.

  4. Magnetic field-induced ordering of a polymer-grafted biomembrane-mimetic hydrogel

    Microsoft Academic Search

    Millicent A. Firestone; David M. Tiede; Sönke Seifert

    2000-01-01

    A biomembrane-mimetic complex fluid that spontaneously orients in the presence of a magnetic field to yield a highly ordered lamellar structure is described. Macroscopically oriented lamellae were produced by exploiting the inverted thermoreversible phase transition of the material, that is, by aligning the sample below the phase transition temperature (<16 C)(i.e., in the fluid, hexagonal micellar phase) and warming to

  5. A real space description of magnetic field induced melting in the charge ordered manganites: I. The clean limit

    NASA Astrophysics Data System (ADS)

    Mukherjee, Anamitra; Majumdar, Pinaki

    2014-10-01

    We study the melting of charge order in the half doped manganites using a model that incorporates double exchange, antiferromagnetic superexchange, and Jahn-Teller coupling between electrons and phonons. We primarily use a real space Monte Carlo technique to study the phase diagram in terms of applied field (h) and temperature (T), exploring the melting of charge order with increasing h and its recovery on decreasing h. We observe hysteresis in this response, and discover that the "field melted" high conductance state can be spatially inhomogeneous even without extrinsic disorder. The hysteretic response plays out in the background of field driven equilibrium phase separation. Our results, exploring h, T, and the electronic parameter space, are backed up by analysis of simpler limiting cases and a Landau framework for the field response. This paper focuses on our results in the "clean" systems, a companion paper studies the effect of cation disorder on the melting phenomena.

  6. Disordered ground state and magnetic field-induced long-range order in an S=3/2 antiferromagnetic honeycomb lattice compound Bi3Mn4O12(NO3).

    PubMed

    Matsuda, M; Azuma, M; Tokunaga, M; Shimakawa, Y; Kumada, N

    2010-10-29

    Bi3Mn4O12(NO3), in which the Mn4+ ions carry S=3/2, is the first honeycomb lattice system that shows no long-range magnetic order. Using neutron scattering, we have determined that short-range antiferromagnetic correlations develop at low temperatures. Applied magnetic fields induce a magnetic transition, in which the short-range order abruptly expands into a long-range order. PMID:21231130

  7. Magnetic-field-induced shape recovery by reverse phase transformation

    Microsoft Academic Search

    R. Kainuma; Y. Imano; W. Ito; Y. Sutou; H. Morito; S. Okamoto; O. Kitakami; K. Oikawa; A. Fujita; T. Kanomata; K. Ishida

    2006-01-01

    Large magnetic-field-induced strains have been observed in Heusler alloys with a body-centred cubic ordered structure and have been explained by the rearrangement of martensite structural variants due to an external magnetic field. These materials have attracted considerable attention as potential magnetic actuator materials. Here we report the magnetic-field-induced shape recovery of a compressively deformed NiCoMnIn alloy. Stresses of over 100MPa

  8. Magnetic-Field Effects on Quadrupolar Ordering in a ? 8-Quartet System CeB 6

    NASA Astrophysics Data System (ADS)

    Shiina, Ryousuke; Shiba, Hiroyuki; Thalmeier, Peter

    1997-06-01

    A theory of the antiferro-quadrupolar ordering in CeB6 is developed in the framework of the ?8-quartet basis. Possible ordered phases under the external magnetic field are classified in terms of their symmetry properties, and the relations between quadrupolar order parameters and field-induced moments are established. Then we formulate a mean-field theory of Ohkawa's RKKY model based on the group-theoretical consideration. The stability of the possible phases and the resulting phase diagrams are analyzed in connection with the character of quadrupolar moments, the influence of induced moments and the form of Zeeman term. Considering available experimental results, we introduce an improved model with asymmetric interactions and discuss the phase diagram of CeB6. The connection between magnetostriction and uniform quadrupolar moments is discussed.

  9. Magnetic-Field-Induced Electric Polarization in Multiferroic Nanostructures

    Microsoft Academic Search

    Ce-Wen Nan; Gang Liu; Yuanhua Lin; Haydn Chen

    2005-01-01

    Magnetic-field-induced electric polarization in nanostructured multiferroic composite films was studied by using the Green's function approach. The calculations showed that large magnetic-field-induced polarization could be produced in multiferroic nanostructures due to enhanced elastic coupling interaction. Especially, the 1-3 type films with ferromagnetic nanopillars embedded in a ferroelectric matrix exhibited large magnetic-field-induced polarization responses, while the 2-2 type films with ferroelectric

  10. Structure and orientational ordering in a fluid of elongated quadrupolar molecules

    NASA Astrophysics Data System (ADS)

    Singh, Ram Chandra

    2013-01-01

    A second-order density-functional theory is used to study the effect of quadrupolar interactions on the isotropic-nematic transition in a system of fluids of elongated molecules interacting via the Gay-Berne potential. The direct pair-correlation functions of the coexisting isotropic fluid that enter in the theory as input information are obtained by solving the Ornstein-Zernike equation using the Percus-Yevick integral equation theory in the (reduced) temperature range of 1.6?T??3.0 for different densities, temperatures and quadrupole moments. Using the harmonic coefficients of the direct pair-correlation functions, isotropic-nematic phase coexistence and thermodynamic parameters have been calculated. The theoretical results have been compared with the available computer simulation results.

  11. Magnetic-field-induced nonequilibrium structures in a ferrofluid emulsion

    Microsoft Academic Search

    George A. Flores; Jing Liu; M. Mohebi; N. Jamasbi

    1999-01-01

    Using optical microscopy, we studied magnetic-field-induced structures in a confined ferrofluid emulsion where the magnetic field is applied quickly as a step function. Columnar, bent-wall-like, and labyrinthine structures in three dimensions are observed, corresponding to disks, ``worms,'' and branchlike patterns in cross-sectional area normal to the magnetic-field direction. These two-dimensional structures are characterized by both the ratio of worms to

  12. Magnetic-field-induced liquid metal droplet manipulation

    NASA Astrophysics Data System (ADS)

    Kim, Daeyoung; Lee, Jeong-Bong

    2015-01-01

    We report magnetic-field-induced liquid metal droplet on-demand manipulation by coating a liquid metal with ferromagnetic materials. The gallium-based liquid metal alloy has a challenging drawback that it is instantly oxidized in ambient air, resulting in surface wetting on most surfaces. When the oxidized surface of the droplet is coated with ferromagnetic materials, it is non-wettable and can be controlled by applying an external magnetic field. We coated the surface of a liquid metal droplet with either an electroplated CoNiMnP layer or an iron (Fe) particle by simply rolling the liquid metal droplet on an Fe particle bed. For a paper towel, the minimum required magnetic flux density to initiate movement of the ~8 ?L Fe-particle-coated liquid metal droplet was 50 gauss. Magnetic-field-induced liquid metal droplet manipulation was investigated under both horizontal and vertical magnetic fields. Compared to the CoNiMnP-electroplated liquid metal droplet, the Fe-particle-coated droplet could be well controlled because Fe particles were uniformly coated on the surface of the droplet. With a maximum applied magnetic flux density of ~1,600 gauss, the CoNiMnP layer on the liquid metal broke down, resulting in fragmentation of three smaller droplets, and the Fe particle was detached from the liquid metal surface and was re-coated after the magnetic field had been removed.

  13. Mössbauer Spectroscopy of the Magnetic-Field-Induced Ferroelectric Phase of CuFeO2

    NASA Astrophysics Data System (ADS)

    Nakamura, Shin; Kobayashi, Yasuhiro; Kitao, Shinji; Seto, Makoto; Fuwa, Akio; Terada, Noriki

    2015-02-01

    57Fe Mössbauer spectroscopy in an applied magnetic field has been conducted on single crystals of CuFeO2 and CuFe0.965Ga0.035O2 in order to investigate magnetic-field-induced ferroelectric states. The Mössbauer spectra observed under a magnetic field change significantly, corresponding to magnetic-field-induced phase transitions. In the ferroelectric incommensurate (FEIC) phase (7 < Hex < 13 T), the spectrum can be explained by a model with spins distributed at approximately 20, 95, and 160° from the c-axis in the (110) plane. This spin configuration resembles the "complex noncollinear spin configuration (CNC)" model proposed theoretically. In the FEIC phase, the isomer shift is larger, while the quadrupole splitting and average hyperfine field are smaller than those in the collinear four sublattice (4SL, 0 < Hex < 7 T) and five sublattice (5SL, Hex > 13 T) phases. In addition, a noticeable change in the hyperfine field is observed with varying magnetic field. We consider that these changes indicate the change in the electronic state of the Fe3+ ion, possibly modified by a spin-orbit interaction.

  14. Optical gyrotropy in quadrupolar Kondo systems

    NASA Astrophysics Data System (ADS)

    Lee, SungBin; Paramekanti, Arun; Kim, Yong Baek

    2015-01-01

    Recent experiments point to a variety of intermetallic systems which exhibit exotic quadrupolar orders driven by the Kondo coupling between conduction electrons and localized quadrupolar degrees of freedom. Using a Luttinger k .p Hamiltonian for the conduction electrons, we study the impact of such quadrupolar order on their energies and wave functions. We discover that such quadrupolar orders can induce a nontrivial Berry curvature for the conduction electron bands, leading to a nonvanishing optical gyrotropic effect. We estimate the magnitude of the gyrotropic response in a candidate quadrupolar material, PrPb3, and discuss the resulting Faraday rotation in thin films.

  15. 12% magnetic field-induced strain in Ni-Mn-Ga-based non-modulated martensite

    NASA Astrophysics Data System (ADS)

    Sozinov, A.; Lanska, N.; Soroka, A.; Zou, W.

    2013-01-01

    Magnetic field-induced strain (MFIS) of 12% is reported in ferromagnetic Ni46Mn24Ga22Co4Cu4 martensite exhibiting non-modulated (NM) tetragonal crystal structure with lattice parameter ratio c /a>1. The strain was measured at ambient temperature in a magnetic field of the order of 1 T. The twinning stress ?TW and the magnetic stress ?MAG were also measured and the condition for a giant MFIS observation ?TW

  16. Quadrupolar waves in uranium dioxide.

    PubMed

    Carretta, S; Santini, P; Caciuffo, R; Amoretti, G

    2010-10-15

    In presence of active orbital degrees of freedom, elementary excitations around a broken-symmetry state may include multipolar waves, but none of these exotic dispersive excitation branches has ever been identified. We show that quadrupolar waves constitute a major component of the dynamics of uranium dioxide in its magnetoquadrupolar ordered phase, and that many unexplained features in existing inelastic neutron scattering data, including a whole excitation branch, are associated with these propagating quadrupolar fluctuations. Our model permits us to separate the role of Jahn-Teller and superexchange mechanisms as sources of quadrupolar interactions. PMID:21231002

  17. Calorimetric Study of Magnetic Field-Induced Phase Transitions in - Fulvalenium) -

    NASA Astrophysics Data System (ADS)

    Fortune, Nathanael Alexander

    The particular class of organic conductors known as the Bechgaard salts exhibit a variety of highly anisotropic magnetic, thermal, and electrical phenomena. At low temperatures (below 10 kelvin), the application of a strong magnetic field establishes an effectively lower-dimensional anisotropic Fermi surface, as manifested in a variety of quasi one dimensional and quasi two dimensional thermodynamic and transport properties. Most dramatically, an increasing magnetic field--after suppression of superconductivity, induces a second order phase transition from a metallic to a spin density wave semimetal, followed by a series of first order phase transitions between density wave semimetallic states. This thesis concerns the thermodynamic nature of the low temperature magnetic field induced phase transitions in the Bechgaard charge-transfer salt (TMTSF)2-Cl(O)4. Presented here are the first measurements of the specific heat in magnetic fields up to 30 tesla, as well as the design and construction of a small sample calorimeter capable of operating at dilution refrigerator temperatures in the challenging environment of the high field resistive Bitter magnets. From transport measurements, the existence of a magnetic field induced reentrance into the metallic state has previously been inferred. In this thesis, the unambiguous bulk thermodynamic character of the reentrance is calorimetrically demonstrated. The behavior of the electronic specific heat at the reentrant transition is shown to be consistent with magnetic field enhanced localization. Additionally, quantum oscillations in the high field semimetallic state and the presence of additional structure above the reentrant field are observed. Although these oscillations have also been observed in magnetoresistance and magnetization, the magnitude of the oscillations in the specific heat calls into question all known models for the physical origin of these oscillations.

  18. Magnetic-field-induced nonequilibrium structures in a ferrofluid emulsion

    NASA Astrophysics Data System (ADS)

    Flores, George A.; Liu, Jing; Mohebi, M.; Jamasbi, N.

    1999-01-01

    Using optical microscopy, we studied magnetic-field-induced structures in a confined ferrofluid emulsion where the magnetic field is applied quickly as a step function. Columnar, bent-wall-like, and labyrinthine structures in three dimensions are observed, corresponding to disks, ``worms,'' and branchlike patterns in cross-sectional area normal to the magnetic-field direction. These two-dimensional structures are characterized by both the ratio of worms to total aggregates and the average complexity of the aggregates in a given image. ``Phase'' diagrams are obtained to characterize disk (columnar) to worm (bent-wall) structural transitions as a function of the thickness of the cell used to confine the sample along the field direction, the particle volume fraction, and the rate of the magnetic-field application. The distribution of aggregate complexity for a given image is characterized by the skewness and quality factor to describe the symmetry and width of complexity distribution. The results show that increasing either cell thickness L, particle volume fraction ?, or magnetic field ramping rate R increases the average complexity of the formed patterns as =1.8?3.11L+0.141 log10(R)+0.83, as well as the symmetry and the range of the complexity. This relation can be understood qualitatively. For fast ramping rate R or increasing ? (decreasing the interparticle distance and thus increasing the particle interaction), the strong magnetic interaction between particles does not allow particles enough time to explore the lowest-energy state (columnar structures) before being locked into local energy minima (labyrinthine structures). The L dependence of the complexity supports molecular dynamics simulation results: Chains form first and then aggregate to form complex structures; longer chains have a larger range of attraction.

  19. Magnetic field-induced excitation and optical detection of mechanical modes of microspheres

    E-print Network

    �tügen, Volkan

    Magnetic field-induced excitation and optical detection of mechanical modes of microspheres T We propose a method to excite and detect the mechanical modes of dielectric microspheres In this paper, we propose a method to excite and detect the mechanical modes of dielectric microspheres using

  20. Magnetic field-induced phase transformation & power harvesting capabilities in magnetic shape memory alloys

    E-print Network

    Basaran, Burak

    2011-02-22

    the macroscopic MTM testing system to reveal how these conventional properties were linked to magnetic-field-induced actuation. An actuation stress of 5 MPa and a work output of 157 kJm?3 were obtained by the field-induced martensite variant reorientation (VR...

  1. Magnetic field induced insulator to metal transition in amorphous-GdxSi1 x

    E-print Network

    Hellman, Frances

    Magnetic field induced insulator to metal transition in amorphous-GdxSi1 x W. Teizer*, F. Hellman resistance and magnetoresistance near the metal­insulator transition in films of the amorphous alloys GdxSi1 of magnitude at low T, crosses through an insulator to metal transition and approaches the conductivity of a

  2. Magnetic field-induced deformation in single- and poly-crystalline Ni2MnGa

    Microsoft Academic Search

    S. J. Jeong; B. K. Min; D. W. Shin

    2002-01-01

    Summary form only given. The shape changes of ferromagnetic shape memory alloys (FMSMAs) induced by magnetic field associated with structural and magnetic properties have been investigated to understand the relation between martensite transformation and magnetic properties. In the present study, two mechanisms explaining magnetic field-induced strain behavior and their related energy terms were introduced and shape change under magnetic field

  3. Biomaterials 28 (2007) 11051114 Flow and magnetic field induced collagen alignment

    E-print Network

    Kaufman, Laura

    Biomaterials 28 (2007) 1105­1114 Flow and magnetic field induced collagen alignment Cheng Guo structural protein in the complex microenvironment, known as extracellular matrix (ECM), that surrounds-modified magnetic beads, a small magnet, and an incubator. As such, this is the only collagen alignment technique

  4. Magnetic field induced irreversibility in UNiAl

    SciTech Connect

    Sechovsky, V.; Prokes, K.; Svoboda, P.; Syshchenko, O.; Chernyavski, O.; Sato, H.; Fujita, T.; Suzuki, T.; Doerr, M.; Rotter, M. (and others)

    2001-06-01

    We report on low-temperature measurements of magnetization, magnetoresistivity, Hall resistivity, magnetostriction, and elastic moduli on a UNiAl single crystal in magnetic fields up to 14 T applied along the c axis of the hexagonal structure. UNiAl is an itinerant 5f-electron antiferromagnet below T{sub N}=19.3K. At temperatures below 7 K ({similar_to}0.3T{sub N}), it exhibits a first-order metamagnetic transition (MT) at a critical field {mu}{sub 0}H{sub c}{approximately}11.35T between the low-field antiferromagnetic state and the high-field ferromagnetic one. The transition is accompanied by a sharp anomaly in transport and lattice properties. A striking observation is that the {open_quotes}virgin{close_quotes} curves expressing the field dependence of the various electronic properties clearly differ from those observed on a sample that has once appeared in the high-field state. This irreversibility in bulk properties corresponds to an irreversible change of the magnetic-structure propagation vector within the basal plane observed by neutron diffraction. The different shapes of M(H), {rho}(H), and {rho}{sub H}(H) curves are strongly suggestive of field-induced changes in the spectrum of spin fluctuations, which play a substantial role in the physics of UNiAl. This seems to be corroborated by the effect of {open_quotes}high-field annealing{close_quotes} on the low-temperature specific-heat data. The irreversibility vanishes at temperatures T{ge}7K where the MT loses its first-order character. {copyright} 2001 American Institute of Physics.

  5. Artificial magnetic field induced by an evanescent wave

    NASA Astrophysics Data System (ADS)

    Mochol, Ma?gorzata; Sacha, Krzysztof

    2015-01-01

    Cold atomic gases are perfect laboratories for realization of quantum simulators. In order to simulate solid state systems in the presence of magnetic fields special effort has to be made because atoms are charge neutral. There are different methods for realization of artificial magnetic fields, that is the creation of specific conditions so that the motion of neutral particles mimics the dynamics of charged particles in an effective magnetic field. Here, we consider adiabatic motion of atoms in the presence of an evanescent wave. Theoretical description of the adiabatic motion involves artificial vector and scalar potentials related to the Berry phases. Due to the large gradient of the evanescent field amplitude, the potentials can be strong enough to induce measurable effects in cold atomic gases. We show that the resulting artificial magnetic field is able to induce vortices in a Bose-Einstein condensate trapped close to a surface of a prism where the evanescent wave is created. We also analyze motion of an atomic cloud released from a magneto-optical trap that falls down on the surface of the prism. The artificial magnetic field is able to reflect falling atoms that can be observed experimentally.

  6. Artificial magnetic field induced by an evanescent wave

    PubMed Central

    Mochol, Ma?gorzata; Sacha, Krzysztof

    2015-01-01

    Cold atomic gases are perfect laboratories for realization of quantum simulators. In order to simulate solid state systems in the presence of magnetic fields special effort has to be made because atoms are charge neutral. There are different methods for realization of artificial magnetic fields, that is the creation of specific conditions so that the motion of neutral particles mimics the dynamics of charged particles in an effective magnetic field. Here, we consider adiabatic motion of atoms in the presence of an evanescent wave. Theoretical description of the adiabatic motion involves artificial vector and scalar potentials related to the Berry phases. Due to the large gradient of the evanescent field amplitude, the potentials can be strong enough to induce measurable effects in cold atomic gases. We show that the resulting artificial magnetic field is able to induce vortices in a Bose-Einstein condensate trapped close to a surface of a prism where the evanescent wave is created. We also analyze motion of an atomic cloud released from a magneto-optical trap that falls down on the surface of the prism. The artificial magnetic field is able to reflect falling atoms that can be observed experimentally. PMID:25567430

  7. Artificial magnetic field induced by an evanescent wave.

    PubMed

    Mochol, Ma?gorzata; Sacha, Krzysztof

    2015-01-01

    Cold atomic gases are perfect laboratories for realization of quantum simulators. In order to simulate solid state systems in the presence of magnetic fields special effort has to be made because atoms are charge neutral. There are different methods for realization of artificial magnetic fields, that is the creation of specific conditions so that the motion of neutral particles mimics the dynamics of charged particles in an effective magnetic field. Here, we consider adiabatic motion of atoms in the presence of an evanescent wave. Theoretical description of the adiabatic motion involves artificial vector and scalar potentials related to the Berry phases. Due to the large gradient of the evanescent field amplitude, the potentials can be strong enough to induce measurable effects in cold atomic gases. We show that the resulting artificial magnetic field is able to induce vortices in a Bose-Einstein condensate trapped close to a surface of a prism where the evanescent wave is created. We also analyze motion of an atomic cloud released from a magneto-optical trap that falls down on the surface of the prism. The artificial magnetic field is able to reflect falling atoms that can be observed experimentally. PMID:25567430

  8. Effect of crystal structure on magnetic-field-induced strain in Ni-Mn-Ga

    Microsoft Academic Search

    Alexei Sozinov; Alexander A. Likhachev; Nataliya Lanska; Outi Söderberg; Kari Ullakko; Veikko K. Lindroos

    2003-01-01

    Magnetic shape memory materials are expected to have a high potential in practical applications. Several ferromagnetic materials exhibiting the large magnetic-field-induced strain have been found in recent years. The largest field-induced strain is observed in Ni-Mn-Ga system. The most important experimental results on crystal structure, magnetic anisotropy and twinning stress of martensitic phases in Ni-Mn-Ga having tetragonal five-layered, orthorhombic seven-layered

  9. Crystal structures and magnetic anisotropy properties of Ni-Mn-Ga martensitic phases with giant magnetic-field-induced strain

    Microsoft Academic Search

    A. Sozinov; A. A. Likhachev; K. Ullakko

    2002-01-01

    Summary form only given. Magnetic shape memory materials are expected to have potential for a variety of actuating devices and sensors. Magnetic-field-induced rearrangement of the crystallographic domains (twin variants) can produce a large strain similar to a stress-induced one. We have found a giant magnetic field-induced strain approximately 10% at ambient temperature in a magnetic field less then 1 T

  10. Magnetic field induced tailoring of mechanical behavior of fluid filled micro porous carbon nanotube foam

    NASA Astrophysics Data System (ADS)

    Reddy, Siva Kumar; Mukherjee, Anwesha; Misra, Abha

    2014-06-01

    Compressive loading of the carbon nanotube (CNT) has attracted much attention due to its entangled cellular like structure (CNT foam). This report investigates the mechanical behavior of magnetorheological fluid impregnated micro porous CNT foam that has not been realized before at this scale. Compressive behavior of CNT foam is found to greatly depend on the variation in both fluid viscosity as well as magnetic field intensity. Moreover, maximum achieved stress and energy absorption in CNT foam followed a power law behavior with the magnetic field intensity. Magnetic field induced movement of both CNT and iron oxide particles along the field direction is shown to dominate compressive behavior of CNT foam over highly attractive van der Waals forces between individual CNT. Therefore, this study demonstrates a method for tailoring the mechanical behavior of the fluid impregnated CNT foam.

  11. Magnetic-Field-Induced insulator-conductor transition in SU(2) quenched lattice gauge theory

    E-print Network

    P. V. Buividovich; M. N. Chernodub; D. E. Kharzeev; T. Kalaydzhyan; E. V. Luschevskaya; M. I. Polikarpov

    2010-09-30

    We study the correlator of two vector currents in quenched $SU\\lr{2}$ lattice gauge theory with a chirally invariant lattice Dirac operator with a constant external magnetic field. It is found that in the confinement phase the correlator of the components of the current parallel to the magnetic field decays much slower than in the absence of a magnetic field, while for other components the correlation length slightly decreases. We apply the maximal entropy method to extract the corresponding spectral function. In the limit of zero frequency this spectral function yields the electric conductivity of the quenched theory. We find that in the confinement phase the external magnetic field induces nonzero electric conductivity along the direction of the field, transforming the system from an insulator into an anisotropic conductor. In the deconfinement phase the conductivity does not exhibit any sizable dependence on the magnetic field.

  12. Magnetic-field-induced ferroelectric polarization reversal in magnetoelectric composites revealed by piezoresponse force microscopy.

    PubMed

    Miao, Hongchen; Zhou, Xilong; Dong, Shuxiang; Luo, Haosu; Li, Faxin

    2014-08-01

    Controlling electric polarization (or magnetization) in multiferroic materials with external magnetic fields (or electric fields) is very important for fundamental physics and spintronic devices. Although there has been some progress on magnetic-field-induced polarization reversal in single-phase multiferroics, such behavior has so far never been realized in composites. Here we show that it is possible to reverse ferroelectric polarization using magnetic fields in a bilayer Terfenol-D/PMN-33%PT composite. We realized this by ferroelectric domain imaging using piezoresponse force microscopy (PFM) under applied magnetic field loading. The internal electric field caused by the magnetoelectric (ME) effect in the PMN-PT crystal is considered as the driving force for the 180° polarization switching, and its existence is verified by switching spectroscopy PFM testing under a series of external magnetic fields. A quantitative method is further suggested to estimate the local ME coefficient based on the switching spectroscopy PFM testing results. PMID:24953042

  13. Possible quantum Hall effect in a magnetic-field-induced phase transition in the quasi-one-dimensional CDW organic conductor, HMTSF-TCNQ

    NASA Astrophysics Data System (ADS)

    Murata, Keizo; Fukumoto, Yuhei; Yokogawa, Keiichi; Kang, Woun; Takaoka, Ryo; Tada, Ryota; Hirayama, H.; Brooks, James S.; Graf, David; Yoshino, Harukazu; Sasaki, Takahiko; Kato, Reizo

    2015-03-01

    We have studied the angular dependence of magnetoresistance and Hall effect of the CDW organic conductor, HMTSF-TCNQ in order to see whether a magnetic-field-induced phase exists in the charge density wave (CDW) system, similarly to the magnetic-field-induced SDW phases in (TMTSF)2X. The anomaly in magnetoresistance was observed only around the pressure where the CDW is almost suppressed, i.e. around 0.8-1.1 GPa, but neither at low pressures (0 and 0.5 GPa) nor at high pressure above 2 GPa. This behavior is quite similar to that of (TMTSF)2X. At 1.1 GPa anomalies were found at fields of 0.2 T and 10 T. We speculate that at 1.1 GPa the field-induced phase is located between 0.2 T and 10 T, where 1D Fermi surface sheet and 2D Fermi-surface pocket are present. The Rxy shows plateau structure and Rxx was very small in the same region, suggestive of quantum Hall effect.

  14. Magnetic-field-induced orientation of superconducting MgB2 crystallites determined by x-ray diffraction

    E-print Network

    Vakni, David

    Magnetic-field-induced orientation of superconducting MgB2 crystallites determined by x-ray; published 4 August 2006 X-ray diffraction studies of fine polycrystalline samples of MgB2 the isotropic value =1 see Fig. 4 in Ref. 14 . Some experi- mental studies claim that the H T,H = T,H .12

  15. Dynamic-angle spinning and double rotation of quadrupolar nuclei

    SciTech Connect

    Mueller, K.T. (Lawrence Berkeley Lab., CA (United States) California Univ., Berkeley, CA (United States). Dept. of Chemistry)

    1991-07-01

    Nuclear magnetic resonance (NMR) spectroscopy of quadrupolar nuclei is complicated by the coupling of the electric quadrupole moment of the nucleus to local variations in the electric field. The quadrupolar interaction is a useful source of information about local molecular structure in solids, but it tends to broaden resonance lines causing crowding and overlap in NMR spectra. Magic- angle spinning, which is routinely used to produce high resolution spectra of spin-{1/2} nuclei like carbon-13 and silicon-29, is incapable of fully narrowing resonances from quadrupolar nuclei when anisotropic second-order quadrupolar interactions are present. Two new sample-spinning techniques are introduced here that completely average the second-order quadrupolar coupling. Narrow resonance lines are obtained and individual resonances from distinct nuclear sites are identified. In dynamic-angle spinning (DAS) a rotor containing a powdered sample is reoriented between discrete angles with respect to high magnetic field. Evolution under anisotropic interactions at the different angles cancels, leaving only the isotropic evolution of the spin system. In the second technique, double rotation (DOR), a small rotor spins within a larger rotor so that the sample traces out a complicated trajectory in space. The relative orientation of the rotors and the orientation of the larger rotor within the magnetic field are selected to average both first- and second-order anisotropic broadening. The theory of quadrupolar interactions, coherent averaging theory, and motional narrowing by sample reorientation are reviewed with emphasis on the chemical shift anisotropy and second-order quadrupolar interactions experienced by half-odd integer spin quadrupolar nuclei. The DAS and DOR techniques are introduced and illustrated with application to common quadrupolar systems such as sodium-23 and oxygen-17 nuclei in solids.

  16. High Magnetic Field-Induced Birefringence in Lyotropic Chromonic Liquid Crystals

    NASA Astrophysics Data System (ADS)

    Ostapenko, T.; Nastishin, Yu.; Gleeson, J. T.; Sprunt, S. N.; Lavrentovich, O. D.; Collings, P. J.

    2009-03-01

    We studied the effect of magnetic-field induced birefringence of a 14% solution of disodium cromoglycate (DSCG) in water at temperatures above the nematic-isotropic coexistence region. According to Landau-deGennes mean field theory, we expect to find a linear relationship between the inverse of the induced birefringence, ?n, and the quantity (T-T*), where T* is the stability limit of the isotropic phase. Using the 31 T resistive magnet at the National High Magnetic Field Laboratory, we observed that, as we increase the temperature above the coexistence region, we deviate from this linear dependence. Our data shows that ?n goes to zero, whereas Landau-deGennes predicts that ?n should decrease asymptotically. This may be due to the lack of isodesmic aggregate formation at a finite temperature above the coexistence region.Supported by NSF (DMR-0710544 and DMR-0606160). Work performed at NHMFL, supported by NSF cooperative agreements DMR-0084173, the State of Florida and the DOE.

  17. Magnetic-field-induced DNA strand breaks in brain cells of the rat.

    PubMed Central

    Lai, Henry; Singh, Narendra P

    2004-01-01

    In previous research, we found that rats acutely (2 hr) exposed to a 60-Hz sinusoidal magnetic field at intensities of 0.1-0.5 millitesla (mT) showed increases in DNA single- and double-strand breaks in their brain cells. Further research showed that these effects could be blocked by pretreating the rats with the free radical scavengers melatonin and N-tert-butyl-alpha-phenylnitrone, suggesting the involvement of free radicals. In the present study, effects of magnetic field exposure on brain cell DNA in the rat were further investigated. Exposure to a 60-Hz magnetic field at 0.01 mT for 24 hr caused a significant increase in DNA single- and double-strand breaks. Prolonging the exposure to 48 hr caused a larger increase. This indicates that the effect is cumulative. In addition, treatment with Trolox (a vitamin E analog) or 7-nitroindazole (a nitric oxide synthase inhibitor) blocked magnetic-field-induced DNA strand breaks. These data further support a role of free radicals on the effects of magnetic fields. Treatment with the iron chelator deferiprone also blocked the effects of magnetic fields on brain cell DNA, suggesting the involvement of iron. Acute magnetic field exposure increased apoptosis and necrosis of brain cells in the rat. We hypothesize that exposure to a 60-Hz magnetic field initiates an iron-mediated process (e.g., the Fenton reaction) that increases free radical formation in brain cells, leading to DNA strand breaks and cell death. This hypothesis could have an important implication for the possible health effects associated with exposure to extremely low-frequency magnetic fields in the public and occupational environments. PMID:15121512

  18. Fast deswelling of nanocomposite polymer hydrogels via magnetic field-induced heating for emerging FO desalination.

    PubMed

    Razmjou, Amir; Barati, Mohammad Reza; Simon, George P; Suzuki, Kiyonori; Wang, Huanting

    2013-06-18

    Freshwater shortage is one of the most pressing global issues. Forward osmosis (FO) desalination technology is emerging for freshwater production from saline water, which is potentially more energy-efficient than the current reverse osmosis process. However, the lack of a suitable draw solute is the major hurdle for commercial implementation of the FO desalination technology. We have previously reported that thermoresponsive hydrogels can be used as the draw agent for a FO process, and this new hydrogel-driven FO process holds promise for further development for practical application. In the present work, magnetic field-induced heating is explored for the purpose of developing a more effective way to recover water from swollen hydrogel draw agents. The composite hydrogel particles are prepared by copolymerization of sodium acrylate and N-isopropylacrylamide in the presence of magnetic nanoparticles (?-Fe2O3, <50 nm). The results indicate that the magnetic heating is an effective and rapid method for dewatering of hydrogels by generating the heat more uniformly throughout the draw agent particles, and thus, a dense skin layer commonly formed via conventional heating from the outside of the particle is minimized. The FO dewatering performance is affected by the loading of magnetic nanoparticles and magnetic field intensity. Significantly enhanced liquid water recovery (53%) is achieved under magnetic heating, as opposed to only around 7% liquid water recovery obtained via convection heating. Our study shows that the magnetic heating is an attractive alternative stimulus for the extraction of highly desirable liquid water from the draw agent in the polymer hydrogel-driven forward osmosis process. PMID:23663180

  19. Novel electrochemical sensing platform based on magnetic field-induced self-assembly of Fe3O4@Polyaniline nanoparticles for clinical detection of creatinine.

    PubMed

    Wen, Tingting; Zhu, Wanying; Xue, Cheng; Wu, Jinhua; Han, Qing; Wang, Xi; Zhou, Xuemin; Jiang, Huijun

    2014-06-15

    A novel electrochemical sensing platform based on magnetic field-induced self-assembly of Fe3O4@Polyaniline nanoparticles (Fe3O4@PANI NPs) has been for the first time fabricated for the sensitive detection of creatinine in biological fluids. The template molecule, creatinine, was self-assembled on the surface of Fe3O4@PANI NPs together with the functional monomer aniline by the formation of N-H hydrogen bonds. After pre-assembled, through the magnetic-induction of the magnetic glassy carbon electrode (MGCE), the ordered structure of molecularly imprinted polymers (MIPs) were established by the electropolymerization and assembled on the surface of MGCE with the help of magnetic fields by a simple one-step approach. The structural controllability of the MIPs film established by magnetic field-induced self-assembly was further studied. The stable and hydrophilic Fe3O4@PANI can not only provide available functionalized sites with which the template molecule creatinine can form hydrogen bond by the abundant amino groups in PANI matrix, but also afford a promoting pathway for electron transfer. The as-prepared molecularly imprinted electrochemical sensor (MIES) shows good stability and reproducibility for the determination of creatinine with the detection limit reached 0.35 nmol L(-1) (S/N=3). In addition, the highly sensitive and selective MIES has been successfully used for the clinical determination of creatinine in human plasma and urine samples. The average recoveries were 90.8-104.9% with RSD lower than 2.7%. PMID:24487254

  20. Martensitic transformation and magnetic-field-induced strain in Ni-Mn-Ga magnetic shape memory alloys

    Microsoft Academic Search

    L. C. Zhao; Z. Y. Gao; W. Cai

    2003-01-01

    The present paper deals with the thermal- and stress-induced martensitic transformations, effects of bias magnetic field and external compressive stress on transformation- and magnetic-field-induced strain in Ni-Mn-Ga alloys. The effect of the external magnetic field and compressive stress on the reorientation of martensitic variants is discussed. It is found that the stress-induced spear-like martensitic crystal forms at the beginning of

  1. In situ neutron diffraction study of magnetic field induced martensite reorientation in Ni Mn Ga under constant stress

    Microsoft Academic Search

    P. Molnar; P. Sittner; V. Novak; J. Prokleska; V. Sechovsky; B. Ouladdiaf; S. P. Hanulla; O. Heczko

    2008-01-01

    The magnetic field induced reorientation of martensite twins as a function of a compressive stress and crystallographic direction was studied on a single-crystalline Ni49.7Mn29.3Ga21 magnetic shape memory alloy by the in situ neutron diffraction technique. The compressive stress 0-3 MPa and magnetic field 0-3.5 T were applied perpendicularly to each other along the [001] and [100] ([010]) crystallographic directions of

  2. Crystal structures and magnetic anisotropy properties of Ni-Mn-Ga martensitic phases with giant magnetic-field-induced strain

    Microsoft Academic Search

    A. Sozinov; A. A. Likhachev; K. Ullakko

    2002-01-01

    Several kinds of martensitic phases have been found in nonstoichiometric Ni2MnGa alloys in numerous recent studies. The structural, magnetic, and mechanical properties important for a giant magnetic-field-induced strain response in these alloys are presented. Depending on the martensite crystal structure Ni-Mn-Ga alloys are able to show a really giant (about 6% or 10%) strain response in a magnetic field less

  3. Magnetic field-induced phase transformation in NiMnCoIn magnetic shape memory alloys - a new actuation mechanism with large work output

    Microsoft Academic Search

    Haluk E. Karaca; Ibrahim Karaman; Burak Basaran; Yang Ren; Yuny I. Chumlyakov; Hans J. Maier

    2009-01-01

    Magnetic shape memory alloys (MSMAs) have recently been developed into a new class of functional materials that are capable of magnetic-field-induced actuation, mechanical sensing, magnetic refrigeration, and energy harvesting. In the present work, the magnetic field-induced martensitic phase transformation (FIPT) in NiMn{sub 36.5}CoIn{sub 13.5} MSMA single crystals is characterized as a new actuation mechanism with potential to result in ultra-high

  4. Thermodynamics of the magnetic-field-induced "normal" state in an underdoped high Tc superconductor

    NASA Astrophysics Data System (ADS)

    Riggs, Scott Chandler

    High magnetic fields are used to kill superconductivity and probe what happens to system when it cannot reach the ideal ground state, i.e. what is the normal-state ground state? Early work in High-Tc, where the application of magnetic field destroyed the zero resistance state and recovered a resistivity value that connected continuously with the zero field curve, lead people to believe this magnetic-field-induced-state had fully driven the system normal, revealing the true underlying ground state, without any vestige of superconductivity. Many experiments done in this region of phase space have results interpreted as coming from the low energy ground state excitations. With the emergence of ultra-clean crystals in a unique family of hole doped high-Tc superconductors, YBa2Cu3O 7-delta, YBCO, a new and highly unexpected phenomena of quantum oscillations were discovered, and they followed the standard Liftshitz-Kosevich (LK) theory for a normal metal. The results suddenly made the problem of high-T c appear to be analogous to superconductivity in the organics, which is brought about by a wave-vector nesting and Fermi surface reconstruction. The only problem, it appeared, that needed to be reconciled was with Angle Resolved Photo-Emission Spectroscopy (ARPES) and Scanning Tunneling Microscopy (STM) data that claimed to see no such Fermi surface, instead only "arcs", a set of disconnected segments in the Brillouin zone which quasiparticle peaks are observed at the Fermi energy, which in a mean field description does not allow for a continuous Fermi surface contour. These two discrepancies led to the "arc vs pocket" debate, which is still unresolved. The other kink in the quantum oscillation armor is that, to this date, quantum oscillations in the hole-doped cuprates have only been seen in YBCO, the only cuprate structure to have CuO chains, which conduct and are located in between two CuO2 superconducting planes in the unit cell. In an attempt to reconcile the "arc vs pocket" debate we measure specific heat on an ultra-clean de-twinned single crystal of underdoped YBCO 6.56 with a Tc = 60 K, up to fields twice irreversibility field, define as the onset of the resistive transition. The zero temperature extrapolation of the electronic contribution to the specific heat, gamma, is the total quasiparticle density of states. For a two-dimensional system with parabolic energy bands, gamma is simply the sum of each pocket multiplied by its effective mass. Therefore, by determining gamma at high fields and using previously determined values for the effective mass from quantum oscillation transport measurements we can simply play a counting game to determine the number of pockets in the Fermi surface. Furthermore, at low fields the response to the specific heat as a function of magnetic field in a d-wave superconductor is known to have a (H) dependence, and we can look for deviations from this (H) , which are expected to happen when the system is no longer in a superconducting state. Results from our specific heat experiment shed new light on the true nature of the magnetic field induced "normal" state, and should force reinterpretation of many experimental findings. The specific heat measurements foremost show a smooth evolution of gamma from low to high magnetic fields which follows a Ac (H) dependence, with the prefactor, Ac giving the correct magnitude for the anisotropy of the d-wave superconducting gap. This means with the application of magnetic fields strong enough to restore the resistive state, the superconducting gap still exits. Additionally, we see quantum oscillations that follow conventional LK formalism and can determine an effective mass uniquely, where no fitting parameters are required. Interestingly, these oscillations fit on top of the (H) finding. How can the (H) and quantum oscillation whose phenomena arise from very different physics be reconciled? Looking at our own zero field gamma value of 1.85 mJ mol-1 K-2, which is intrinsic for YBCO, allows the pocket counting game

  5. The magnetic-field-induced transition from an expanding plasma to a double layer containing expanding plasma

    SciTech Connect

    Charles, C.; Boswell, R. W. [Space Plasma, Power and Propulsion Group, Research School of Physical Sciences and Engineering, Australian National University, Australian Capital Territory 0200 (Australia)

    2007-11-12

    The magnetic-field-induced transition from a simple expansion to a double layer is experimentally investigated in an argon low pressure radio frequency helicon source plasma. When the magnetic field is increased from 30 to 140 G in the plasma source, an abrupt increase in the plasma density and upstream potential is measured at 50 G. In the downstream plasma, the plasma density and potential show a small decrease with increasing magnetic field and no abrupt change. When the upstream jump is measured, simultaneous measurements in the downstream plasma show an ion beam characteristic of a double layer near the source exit.

  6. Over 7% magnetic field-induced strain in a Ni-Mn-Ga five-layered martensite

    NASA Astrophysics Data System (ADS)

    Pagounis, E.; Chulist, R.; Szczerba, M. J.; Laufenberg, M.

    2014-08-01

    A Ni-Mn-Ga single crystal with a modulated five-layered martensite structure is reported, demonstrating giant magnetic field induced strain (MFIS) of 7.1% at room temperature and of 6% at temperatures close to the austenite transformation (TA = 71 °C). The room temperature MFIS clearly exceeds the best results of around 6% measured earlier in 10M martensites. The larger MFIS is connected to the huge (>1%) change in the lattice distortion of the 10M structure, obtained within a narrow temperature interval of 47 K, which has been previously observed only during intermartensitic transformation. The present material shall effectively reduce the size of magnetic shape memory actuators.

  7. Magnetic-field-induced spin flop transition and magnetoelectric effect in Ca2Fe2-xAlxO5

    NASA Astrophysics Data System (ADS)

    Abe, N.; Khanh, N. D.; Sasaki, T.; Arima, T.

    2014-02-01

    Magnetic-field-induced spin flop transition and magnetoelectric effect in noncentrosymmetric Ca2Fe2-xAlxO5 (0.5 ? x ? 1) single crystals have been investigated. Temperature dependence of magnetic susceptibility shows that the compounds have antiferromagnetic transition temperatures TN above room temperature. The spin easy axis varies from the c axis to the a axis with increasing Al content x. When a magnetic field is applied along the spin easy axis, a spin flop transition takes place, accompanied by anomalies in the electric polarization and dielectric constant. The anomalies can be ascribed to a noncollinear spin arrangement in the domain walls between two magnetic phases and/or the spin direction dependent modulation of the metal-ligand hybridization. Such a polarization change with a spin flop transition in polar antiferromagnets may provide a route to realize large magnetoelectric coupling at high temperatures.

  8. Magnetic field-induced phase transformation and variant reorientation in Ni2MnGa and NiMnCoIn magnetic shape memory alloys

    E-print Network

    Karaca, Haluk Ersin

    2009-05-15

    The purpose of this work is to reveal the governing mechanisms responsible for the magnetic field-induced i) martensite reorientation in Ni2MnGa single crystals, ii) stress-assisted phase transformation in Ni2MnGa single crystals and iii) phase...

  9. J. Phys. I Fance 7 (1997) 599-610 APRIL 1997, PAGE 599 Magnetic Field-Induced Phase Transition in the Quasi

    E-print Network

    Boyer, Edmond

    1997-01-01

    similar for all the members of this family and is composed of both a close 2D orbit and lD sheetsJ. Phys. I £Fance 7 (1997) 599-610 APRIL 1997, PAGE 599 Magnetic Field-Induced Phase Transition transition at ambient pressure which is destroyed by increases in pressure [7j while the compound ,vith &~ IX

  10. Phase equilibria in quadrupolar fluid binary mixtures

    NASA Astrophysics Data System (ADS)

    Scalise, O. H.; Gianotti, R. D.; Zarragoicoechea, G. J.; Rodriguez, A. E.

    1988-07-01

    Phase equilibria in fluid binary mixtures of nonpolar-quadrupolar and quadrupolar-quadrupolar fluids are investigated using the perturbation scheme of Scalise et al. (1987). It is found that a molecular model with a Lennard-Jones function and a quadrupole-quadrupole interaction as the perturbing potential to the hard-sphere fluid reference system is able to predict the shape of the coexistence curves observed in He-N2, H2-N2, and Ne-N2 mixtures.

  11. Angular dependence of magnetic-field-induced phase transitions in CeCoIn_5e

    NASA Astrophysics Data System (ADS)

    Fortune, Nathanael

    2003-03-01

    We present the first calorimetric evidence for a magnetic-field-angle-dependent Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) superconducting state in the quasi 2-D heavy fermion superconductor CeCoIn5 at low temperatures. With Hallel[001], we confirm the presence of a single (first-order) phase transitionfootnote[1]A. Bianchi et al., PRL 89 (2002) 137002. from the superconducting to normal state. With H?[001], however, we observe two phase transitions: a first-order phase transition at Hc2 plus an additional (higher-order) phase transition within the superconducting state. As the field is rotated away from this orientation, H_c2 decreases in field but the threshold field for the second transition remains unchanged. Once H_c2 falls below this threshold field, however, the second transition is no longer observed. These results are in good agreement with recent theoretical predictionsfootnote[2]S. Matsuo et al., J. Phys. Soc. Jpn 67(1998)280; M. Houzet and A. Buzdin, PRB 63(2001)184521. for a second order phase transition between a uniform superconducting phase (U) and a spatially modulated FFLO superconducing phase with increasing magnetic field, followed by a first-order phase transition between the FFLO to normal metal phase (N) at still higher fields. The phase boundary for this new, lower field transition decreases with decreasing temperature, in disagreement with traditional models but in agreement with calculationsfootnote[3]H. Burkhardt and D. Rainer, Ann. der Physik 3(1994)181. that include the effect of the spin-dependent exchange interaction.

  12. Magnetic field induced properties of manganite perovskites with colossal magnetoresistance (invited)

    SciTech Connect

    Xiao, G.; Gong, G.Q.; Canedy, C.L. [Department of Physics, Brown University, Providence, Rhode Island 02912 (United States)] [Department of Physics, Brown University, Providence, Rhode Island 02912 (United States); McNiff, E.J. , Jr. [Francis Bitter National Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Francis Bitter National Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Gupta, A. [IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States)] [IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States)

    1997-04-01

    We present a systematic study of the magnetotransport and magnetic properties of the half-doped La{sub 0.5}Ca{sub 0.5}MnO{sub 3+{delta}} system. The solid is a metamagnet which undergoes a first-order antiferromagnet (AFM) to ferromagnet (FM) phase transition under a field or by changing temperature. Associated with the AFM{endash}FM transition is an insulator to metal transition. A maximum 10{sup 9}-fold magnetoresistance ratio has been observed at 4.2 K between the least and the most conductive states. At low T ({le}50 K), we have also observed two additional metastable electronic states in the canted AFM state at certain fields. The resistivity of each state differs from one another by at least one order of magnitude. The existence of these multiple states may be related to the unique charge- and spin-ordered state of the half-doped manganite. {copyright} {ital 1997 American Institute of Physics.}

  13. Magnetic-field-induced ferroelectric polarization flop under pressure in TbMnO3

    NASA Astrophysics Data System (ADS)

    Aoyama, Takuya; Iyama, Ayato; Shimizu, Katsuya; Kimura, Tsuyoshi

    2015-03-01

    Magnetoelectric properties of multiferroic TbMnO3 with a cycloidal spiral spin order were investigated as functions of applied pressure and magnetic field. We found that a flop of ferroelectric polarization occurs by applying a magnetic field along the a axis under 2-3 GPa below the Néel temperature of Tb moments. A possible origin of the magnetoelectric transition is discussed based on the observed pressure and magnetic-field profiles of the ferroelectric polarization and the dielectric relaxation. This flop would originate from the 90° rotation of the cycloidal spiral plane from the bc plane to the ab plane.

  14. Magnetic-Field-Induced Insulator-Metal Transition in (Pr1?yYy)0.7Ca0.3CoO3 at Ultrahigh Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Lee, Suyeon; Matsuda, Yasuhiro H.; Naito, Tomoyuki; Nakamura, Daisuke; Takeyama, Shojiro

    2015-04-01

    The (Pr1?yYy)0.7Ca0.3CoO3 (y ? 0.0625) compounds show a first-order metal-insulator (MI) transition and simultaneous spin-state (SS) transition upon a change in the temperature. We have measured the electrical resistivity of the samples with y = 0.075 (the transition temperature, TMI = 64 K) and 0.10 (TMI = 93 K) in ultrahigh magnetic fields of up to 120 T using a contactless radio-frequency transmission technique. We observed a magnetic-field-induced insulator-metal (IM) transition with large hysteresis below TMI and obtained the temperature-magnetic field phase diagrams. A possible mechanism of the field-induced IM and SS transitions is discussed.

  15. Magnetic field induced polarization and magnetoelectric effect of Ba0.8Ca0.2TiO3-Ni0.2Cu0.3Zn0.5Fe2O4 nanomultiferroic

    NASA Astrophysics Data System (ADS)

    Sadhana, Katlakunta; Ramana Murthy, Sarabu; Jie, Shang; Xie, Yali; Liu, Yiwei; Zhan, Qingfeng; Li, Run-Wei

    2013-05-01

    The xBa0.8Ca0.2TiO3-(1 - x)NiCuZn ferrite (x = 0.1, 0.3, 0.5, 0.7, and 0.9) nanocomposites were prepared by using sol-gel method. The densification of these composites was carried out using microwave sintering method. The magnetic field induced changes in the ferroelectric polarization loop may support the possible magnetoelectric coupling between Ba0.8Ca0.2TiO3 and NiCuZn ferrite phases. The observed change in ferroelectric polarization with applied magnetic field proves the coupling between magnetic and ferroelectric order parameters. The loop change is observed with the composition and with magnetic field. The magnetoelectric coefficient of the nanocomposite with x = 0.3 shows a value of 280 mV/cm Oe is obtained.

  16. Quantum manipulation on the Barium quadrupolar transition

    E-print Network

    Blatt, Rainer

    Quantum manipulation on the Barium quadrupolar transition A diploma thesis in physics submitted and stabilization of a new fiber laser system to ma- nipulate the Barium quadrupolar transition, with the aim with a single Barium ion trapped in a linear Paul trap and Doppler cooled to the Lamb Dicke regime. The narrow

  17. Magnetic field induced enlargement of the regime of critical fluctuations in the classical superconductor V3Si from high-resolution specific heat experiments

    NASA Astrophysics Data System (ADS)

    Zheng, Y.; Liu, Y.; Toyota, N.; Lortz, R.

    2015-02-01

    We present high-resolution specific heat data from a high-purity single crystal of the classical superconductor V3Si, which reveal tiny lambda-shape anomalies at the superconducting transition superimposed onto the BCS specific heat jump in magnetic fields of 2 T and higher. The appearance of these anomalies is accompanied by a magnetic-field-induced broadening of the superconducting transition. We demonstrate, using scaling relations predicted by the fluctuation models of the 3d-XY and the 3d-lowest-Landau-level (3d-LLL) universality class that the effect of critical fluctuations becomes experimentally observable due to of a magnetic field-induced enlargement of the regime of critical fluctuations. The scaling indicates that a reduction of the effective dimensionality due to the confinement of quasiparticles into low Landau levels is responsible for this effect.

  18. Magnetic field induced enlargement of the regime of critical fluctuations in the classical superconductor V3Si from high-resolution specific heat experiments.

    PubMed

    Zheng, Y; Liu, Y; Toyota, N; Lortz, R

    2015-02-25

    We present high-resolution specific heat data from a high-purity single crystal of the classical superconductor V(3)Si, which reveal tiny lambda-shape anomalies at the superconducting transition superimposed onto the BCS specific heat jump in magnetic fields of 2 T and higher. The appearance of these anomalies is accompanied by a magnetic-field-induced broadening of the superconducting transition. We demonstrate, using scaling relations predicted by the fluctuation models of the 3d-XY and the 3d-lowest-Landau-level (3d-LLL) universality class that the effect of critical fluctuations becomes experimentally observable due to of a magnetic field-induced enlargement of the regime of critical fluctuations. The scaling indicates that a reduction of the effective dimensionality due to the confinement of quasiparticles into low Landau levels is responsible for this effect. PMID:25640214

  19. Magnetic field-induced phase transformation and variant reorientation in nickel-manganese-gallium and nickel-manganese-cobalt-indium magnetic shape memory alloys

    Microsoft Academic Search

    Haluk Ersin Karaca

    2007-01-01

    The purpose of this work is to reveal the governing mechanisms responsible for the magnetic field-induced (i) martensite reorientation in Ni 2MnGa single crystals, (ii) stress-assisted phase transformation in Ni2MnGa single crystals and (iii) phase transformation in NiMnCoIn alloys. The ultimate goal of utilizing these mechanisms is to increase the actuation stress levels in magnetic shape memory alloys (MSMAs). Extensive

  20. Understanding the quadrupolar structures of UPd3

    NASA Astrophysics Data System (ADS)

    McEwen, K. A.; Walker, H. C.; Le, M. D.; McMorrow, D. F.; Colineau, E.; Wastin, F.; Wilkins, S. B.; Park, J.-G.; Bewley, R. I.; Fort, D.

    2007-03-01

    UPd3 exhibits four phase transitions below T0=7.8 K, attributed to a succession of antiferroquadrupolar (AFQ) orderings of the 5f2 uranium ions localised on the quasi-cubic sites of the dhcp crystal structure. From earlier polarised neutron diffraction measurements in a magnetic field, we proposed that the order parameter of the phase below T0 is Q and a model for the order parameters of the four phases was subsequently developed. This model has now been tested experimentally with measurements of the azimuthal dependence of the intensities of the quadrupolar reflections in the different phases, by means of X-ray resonant scattering (XRS) studies at ESRF. The results indicate that the order parameter, in zero field, of the phase below T0 is Qzx. Our model provides an explanation for these apparently contradictory results. New measurements of the heat capacity of UPd3 at low temperatures have revealed the entropy changes at each of the four transitions. We find that the entropy changes ( ?S) at T0 and T+1=6.9 K are minimal, whereas ?S is large at T-1=6.7 K. From this information together with the new XRS results, we have extended our model to provide an explanation of the AFQ structures of UPd3.

  1. Probing Quadrupolar Nuclei by Solid-State NMR Spectroscopy: Recent Advances

    SciTech Connect

    Fernandez, Christian; Pruski, Marek

    2011-06-08

    Solid-state nuclear magnetic resonance (NMR) of quadrupolar nuclei has recently undergone remarkable development of capabilities for obtaining structural and dynamic information at the molecular level. This review summarizes the key achievements attained during the last couple of decades in solid-state NMR of both integer spin and half-integer spin quadrupolar nuclei. We provide a concise description of the first- and second-order quadrupolar interactions, and their effect on the static and magic angle spinning (MAS) spectra. Methods are explained for efficient excitation of single- and multiple-quantum coherences, and acquisition of spectra under low- and high-resolution conditions. Most of all, we present a coherent, comparative description of the high-resolution methods for half-integer quadrupolar nuclei, including double rotation (DOR), dynamic angle spinning (DAS), multiple-quantum magic angle spinning (MQMAS), and satellite transition magic angle spinning (STMAS). Also highlighted are methods for processing and analysis of the spectra. Finally, we review methods for probing the heteronuclear and homonuclear correlations between the quadrupolar nuclei and their quadrupolar or spin-1/2 neighbors.

  2. Magnetic field-induced elastic bending in bilayers of Tb1-xDyxFe2-y and Pb(Zr1-zTiz)O3

    NASA Astrophysics Data System (ADS)

    Jin, Tao; qichao, Wu; Ning, Zhang

    2014-09-01

    Magnetic field-induced strain in the magnetoelectric bilayers of Tb1-xDyxFe2-y and Pb(Zr1-zTiz)O3 was studied. A butterfly shaped strain curve was observed on the surface of Pb(Zr1-zTiz)O3. The shape of the strain curve was found to be related to the sample thickness and the volume fraction occupied by the ferroelectrics in the bilayer. Theoretical analysis and experimental results showed that magnetoelastic bending in the bilayer composites was largely responsible for the butterfly strain curve.

  3. Magnetic Field Induced Phase Transitions in Gd5(Si1.95Ge2.05)Single Crystal and the Anisotropic Magnetocaloric Effect

    SciTech Connect

    H. Tang; V.K. Pecharsky; A.O. Pecharsky; D.L. Schlagel; T.A. Lograsso; K.A. Gschneidner,jr.

    2004-09-30

    The magnetization measurements using a Gd{sub 5}(Si{sub 1.95}Ge{sub 2.05}) single crystal with the magnetic field applied along three crystallographic directions, [001], [010] and [100], were carried out as function of applied field (0-56 kOe) at various temperatures ({approx}5-320 K). The magnetic-field induced phase transformations at temperature above the zero-field critical temperature, i.e. the paramagnetic (PM) {leftrightarrow} ferromagnetic (FM) transitions with application or removal of magnetic field, are found to be temperature dependent and hysteretic. The corresponding critical fields increase with increasing temperature. The magnetic field (H)-temperature (T) phase diagrams have been constructed for the Gd{sub 5}(Si{sub 1.95}Ge{sub 2.05}) single crystal with field along the three directions. A small anisotropy has been observed. The magnetocaloric effect (MCE) has been calculated from the isothermal magnetization data, and the observed anisotropy correlates with H-T phase diagrams. The results are discussed in connection with the magnetic-field induced martensitic-like structural transition observed in the Gd{sub 5}(Si{sub 2}Ge{sub 2})-type compounds.

  4. Theoretical study of homonuclear J coupling between quadrupolar spins: Single-crystal, DOR, and J-resolved NMR

    NASA Astrophysics Data System (ADS)

    Perras, Frédéric A.; Bryce, David L.

    2014-05-01

    The theory describing homonuclear indirect nuclear spin-spin coupling (J) interactions between pairs of quadrupolar nuclei is outlined and supported by numerical calculations. The expected first-order multiplets for pairs of magnetically equivalent (A2), chemically equivalent (AA?), and non-equivalent (AX) quadrupolar nuclei are given. The various spectral changeovers from one first-order multiplet to another are investigated with numerical simulations using the SIMPSON program and the various thresholds defining each situation are given. The effects of chemical equivalence, as well as quadrupolar coupling, chemical shift differences, and dipolar coupling on double-rotation (DOR) and J-resolved NMR experiments for measuring homonuclear J coupling constants are investigated. The simulated J coupling multiplets under DOR conditions largely resemble the ideal multiplets predicted for single crystals, and a characteristic multiplet is expected for each of the A2, AA?, and AX cases. The simulations demonstrate that it should be straightforward to distinguish between magnetic inequivalence and equivalence using J-resolved NMR, as was speculated previously. Additionally, it is shown that the second-order quadrupolar-dipolar cross-term does not affect the splittings in J-resolved experiments. Overall, the homonuclear J-resolved experiment for half-integer quadrupolar nuclei is demonstrated to be robust with respect to the effects of first- and second-order quadrupolar coupling, dipolar coupling, and chemical shift differences.

  5. Optically detected nuclear quadrupolar interaction of 14N in nitrogen-vacancy centers in diamond

    E-print Network

    Chang S. Shin; Mark C. Butler; Hai-Jing Wang; Claudia E. Avalos; Scott J. Seltzer; Ren-Bao Liu; Alexander Pines; Vikram S. Bajaj

    2014-05-01

    We report sensitive detection of the nuclear quadrupolar interaction of the 14N nuclear spin of the nitrogen-vacancy (NV) center using the electron spin echo envelope modulation technique. We applied a weak transverse magnetic field to the spin system so that certain forbidden transitions became weakly allowed due to second-order effects involving the nonsecular terms of the hyperfine interaction. The weak transitions cause modulation of the electron spin-echo signal, and a theoretical analysis suggests that the modulation frequency is primarily determined by the nuclear quadrupolar frequency; numerical simulations confirm the analytical results and show excellent quantitative agreement with experiments. This is an experimentally simple method of detecting quadrupolar interactions, and it can be used to study spin systems with an energy structure similar to that of the nitrogen vacancy center.

  6. Fabrication and use of a nanoscale Hall probe for measurements of the magnetic field induced by MFM tips.

    PubMed

    Matveev, Victor N; Levashov, Vladimir I; Volkov, Vladimir T; Kononenko, Oleg V; Chernyh, Anatoly V; Knjazev, Maxim A; Tulin, Vyacheslav A

    2008-11-26

    Extraordinary Hall effect probes with 160 nm × 160 nm working area were fabricated using photo- and electron-beam lithographic procedures with the aim of direct measurements of MFM cantilever tip magnetic properties. The magnetic field sensitivity of the probes was 35 ? T(-1). Magnetic induction of the MFM cantilever tips coated by Co and SmCo films was measured with the probes. It was shown that the resolution of the probes was of the order of 10 nm. PMID:21836273

  7. Theory of magnetic-field-induced Bose-Einstein condensation of triplons in Ba3Cr2O8

    NASA Astrophysics Data System (ADS)

    Dodds, Tyler; Yang, Bohm-Jung; Kim, Yong Baek

    2010-02-01

    Motivated by recent experiments on Ba3Cr2O8 , a new spin-dimer compound with spin-1/2 moments of Cr5+ ions, we theoretically investigate the field-induced magnetic ordering in this material in view of the Bose-Einstein condensation (BEC) of triplet excitations (triplons). We apply the self-consistent Hartree-Fock-Popov (HFP) approach to a microscopic Hamiltonian, using the realistic triplon dispersion measured in an inelastic neutron-scattering experiment. In particular, we ask to what extent the BEC of dilute triplons near the critical field can explain the magnetic ordering in this material. For example, we investigate the temperature range where the BEC picture of triplons can be applied via the HFP approach. We also determine the temperature regime where a quadratic approximation of the triplon dispersion works. It is found that the strength of the effective repulsive interaction between triplons is much weaker in Ba3Cr2O8 than in the canonical spin-dimer compound TlCuCl3 . Small effective repulsive interaction in combination with the narrow band of triplons leads to higher density of triplons ncr at the critical point. The combined effect points to a bigger HFP correction Uncr in Ba3Cr2O8 than in TlCuCl3 . Nonetheless, the HFP approach provides a reasonable explanation of the transverse magnetization and the specific-heat data of Ba3Cr2O8 .

  8. Fabrication of one-dimensional Fe3O4/P(GMA-DVB) nanochains by magnetic-field-induced precipitation polymerization.

    PubMed

    Ma, Mingliang; Zhang, Qiuyu; Dou, Jinbo; Zhang, Hepeng; Yin, Dezhong; Geng, Wangchang; Zhou, Yanyang

    2012-05-15

    One-dimensional (1D) magnetic Fe(3)O(4)/P(GMA-DVB) peapod-like nanochains have been successfully synthesized by magnetic-field-induced precipitation polymerization using Fe(3)O(4) as building blocks and P(GMA-DVB) as linker. The Fe(3)O(4) microspheres without surface modification can be arranged with the direction of the external magnetic field in a line via the dipolar interaction between Fe(3)O(4) microspheres and linked permanently via P(GMA-DVB) coating during precipitation polymerization. The length of peapod-like nanochains can be controlled by magnetic field intensity, and the thickness of polymer shell can be tuned by the amount of monomers. Magnetic measurement revealed that these 1D peapod-like nanochains showed highly magnetic sensitivity. In the presence of magnetic field, 1D magnetic Fe(3)O(4)/P(GMA-DVB) peapod-like nanochains can be oriented and aligned along the direction of external magnetic field. PMID:22386309

  9. Theory of Magnetic Field-Induced Bose-Einstein Condensation of Triplons in Ba3Cr2O8

    NASA Astrophysics Data System (ADS)

    Dodds, Tyler; Yang, Bohm Jung; Kim, Yong Baek

    2010-03-01

    We report on a theoretical investigation of the spin-1/2-dimer compound Ba3Cr2O8 in view of the Bose-Einstein condensation (BEC) of triplet excitations under an applied magnetic field. We apply the self-consistent Hartree-Fock-Popov (HFP) approach to a microscopic Hamiltonian, using the realistic triplon dispersion measured in an inelastic neutron scattering experiment. We investigate the temperature range where the BEC picture of magnetic ordering can be applied in this approach. The effective repulsive interaction between triplons is much weaker in Ba3Cr2O8 than in the canonical spin-dimer compound TlCuCl3. Combined with a narrower triplon band, the smaller interaction in Ba3Cr2O8 leads to a higher density of triplons at the critical point and a larger HFP correction to the critical applied field. Nonetheless, the HFP approach provides a reasonable explanation of the transverse magnetization and specific heat data of Ba3Cr2O8.

  10. The origin of the magnetic-field-dependent quadrupolar splitting

    SciTech Connect

    Salsbury, F.R. , Jr. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)] [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Harris, R.A. [Department of Chemistry, University of California, Berkeley, California 94720 (United States)] [Department of Chemistry, University of California, Berkeley, California 94720 (United States)

    1998-11-01

    We confirm that the recently discovered field-dependent nuclear quadrupolar splitting of {sup 131}Xe [T. Meersmann and M. Haake, Phys. Rev. Lett. {bold 81}, 1211 (1998)] arises from a distortion of the electron density due to the applied magnetic field. This distortion depends both linearly and quadratically on the applied field. The existence of the former is due to the coupling to the field and the nuclear spin. The latter is a manifestation of the quadratic Zeeman effect. In addition to confirming the order of magnitude for the observed effect, we show that there should be an asymmetry introduced in the spectra due to the linear coupling with the nuclear spin. This effect has not been seen experimentally. {copyright} {ital 1998 American Institute of Physics.}

  11. Interactions of distinct quadrupolar nematic colloids

    E-print Network

    Z. Eskandari; N. M. Silvestre; M. Tasinkevych; M. M. Telo da Gama

    2012-05-03

    The effective interaction between spherical colloids in nematic liquid crystals is investigated in the framework of the Landau-de Gennes theory. The colloids differ through their interaction with the nematic. While both particles induce quadrupolar far-field distortions in the nematic matrix, with unlike quadrupole moments, one favours homeotropic and the other degenerate planar anchoring of the nematic director. In the strong anchoring regime the colloids with homeotropic anchoring are accompanied by an equatorial disclination line defect, known as "Saturn-ring", while the colloids with degenerate planar anchoring nucleate a pair of antipodal surface defects, called "Boojums". In the linear (large-distance) regime the colloidal interactions are of the quadrupolar type, where the quadrupoles have opposite signs. These are attractive when the colloids are aligned either parallel or perpendicular to the far-field director. At short distance, non-linear effects including "direct" interactions between defects give rise to a repulsion between the particles, which prevents them from touching. This finding supports the stability of nematic colloidal square crystallites the assembly of which has been reported recently.

  12. Temperature stability of magnetic field-induced strain and field-controlled shape memory effect on Ni52Mn16.4Fe8Ga23.6 single crystals

    Microsoft Academic Search

    Y. T. Cui; Z. H. Liu; M. Zhang; G. D. Liu; Y. X. Li; W. L. Wang; G. H. Wu

    2005-01-01

    The temperature dependence of the magnetic field-induced strain (MFIS) and the field-controlled shape memory effect in Ni52Mn16.4Fe8Ga23.6 single crystals were investigated by measuring the MFIS and measuring the magnetic field-enhanced transformation strain with a field bias applied in the [001] and [010] directions of the parent phase, respectively. The results show that such material combined with the martensitic transformation can

  13. Formation of ordered films of axially bridged aluminum phthalocyanine [(tBu){sub 4}PcAl]{sub 2}O via magnetic field-induced reaction

    SciTech Connect

    Basova, Tamara, E-mail: basova@niic.nsc.ru; Berezin, Aleksei; Nadolinny, Vladimir [Nikolaev Institute of Inorganic Chemistry, Russian Academy of Sciences, Lavrentiev Pr., 3, 630090 Novosibirsk (Russian Federation)] [Nikolaev Institute of Inorganic Chemistry, Russian Academy of Sciences, Lavrentiev Pr., 3, 630090 Novosibirsk (Russian Federation); Peisert, Heiko; Chassé, Thomas [Institute for Physical and Theoretical Chemistry, Auf der Morgenstelle 18, 72076 Tübingen (Germany)] [Institute for Physical and Theoretical Chemistry, Auf der Morgenstelle 18, 72076 Tübingen (Germany); Banimuslem, Hikmat; Hassan, Aseel [Materials and Engineering Research Institute, Sheffield Hallam University, Sheffield S1 1WB (United Kingdom)] [Materials and Engineering Research Institute, Sheffield Hallam University, Sheffield S1 1WB (United Kingdom)

    2013-11-28

    The ?-(oxo)bis[tetra-tert-butylphthalocyaninato] aluminum(III) [(tBu){sub 4}PcAl]{sub 2}O films with the crystallites oriented preferably in one direction were obtained via chemical transformation of tetra-tert-butylsubstituted chloroaluminum(III) phthalocyanine (tBu){sub 4}PcAlCl film upon its annealing in magnetic field. A comparative analysis of the influence of post-deposition annealing process without and under applied magnetic field of 1 T, on the orientation and morphology of (tBu){sub 4}PcAlCl and [(tBu){sub 4}PcAl]{sub 2}O films, has been carried out by the methods of UV-vis, Infrared and Raman spectroscopies, XRD as well as atomic force microscopy. The formation of [(tBu){sub 4}PcAl]{sub 2}O films with elongated crystallites having preferential orientation was observed upon heating of the films in magnetic field while annealing without magnetic field under the same conditions does not demonstrate any effect on the structure and morphology of these films. The reasons of the sensitivity of this reaction to the presence of such magnetic field is discussed and studied by electronic paramagnetic resonance spectroscopy.

  14. Quantum phases of quadrupolar Fermi gases in coupled one-dimensional systems

    NASA Astrophysics Data System (ADS)

    Huang, Wen-Min; Lahrz, M.; Mathey, L.

    2014-01-01

    Following the recent proposal to create quadrupolar gases [Bhongale et al., Phys. Rev. Lett. 110, 155301 (2013), 10.1103/PhysRevLett.110.155301], we investigate what quantum phases can be created in these systems in one dimension. We consider a geometry of two coupled one-dimensional (1D) systems, and derive the quantum phase diagram of ultracold fermionic atoms interacting via quadrupole-quadrupole interactions within a Tomonaga-Luttinger-liquid framework. We map out the phase diagram as a function of the distance between the two tubes and the angle between the direction of the tubes and the quadrupolar moments. The latter can be controlled by an external field. We show that there are two magic angles ?B,1c and ?B,2c between 0 and ? /2, where the intratube quadrupolar interactions vanish and change signs. Adopting a pseudospin language with regard to the two 1D systems, the system undergoes a spin-gap transition and displays a zigzag density pattern, above ?B,2c and below ?B,1c. Between the two magic angles, we show that polarized triplet superfluidity and a planar spin-density-wave order compete with each other. The latter corresponds to a bond-order solid in higher dimensions. We demonstrate that this order can be further stabilized by applying a commensurate periodic potential along the tubes.

  15. Evidence for hidden quadrupolar fluctuations behind the octupole order in Ce0.7La0.3B6 from resonant x-ray diffraction in magnetic fields

    NASA Astrophysics Data System (ADS)

    Matsumura, Takeshi; Michimura, Shinji; Inami, Toshiya; Otsubo, Toru; Tanida, Hiroshi; Iga, Fumitoshi; Sera, Masafumi

    2014-01-01

    The multipole ordered phase in Ce0.7La0.3B6, emerging below 1.5 K and named phase IV, has been studied by resonant x-ray diffraction in magnetic fields. By utilizing diamond x-ray phase plates to rotate the incident linear polarization and a conventional crystal analyzer system, full linear polarization analysis has been performed to identify the order parameters. The analysis shows that the ?5g(Oyz, Ozx, Oxy) quadrupoles are more induced by the field than the ?3g (O20 and O22) quadrupoles on the ?5u (Tx+y +z?) antiferro-octupole order in phase IV. The problem is that this result is contradictory to a mean-field calculation, which inevitably gives the ?3g quadrupole as the main induced moment. This result indicates that the ?5g quadrupole order is close in energy. We consider that a large fluctuation of the ?5g quadrupole is hidden behind the primary ordering of the ?5u octupole and that the multipolar fluctuation significantly affects the ordering phenomenon.

  16. Spin temperature applied to an inhomogeneously broadened pure quadrupolar resonance

    NASA Astrophysics Data System (ADS)

    Singh, Marsha A.; Armstrong, Robin L.

    1988-07-01

    The application of the spin-temperature hypothesis to inhomogeneously broadened pure quadrupolar resonances is dependent on the identification of appropriate quasi-invariants. Three models of inhomogeneity in the dominant quadrupolar spin coupling are discussed and employed to predict the spin response to the modified Jeener-Broekaert multiple-pulse sequence. The set of generators for the SU(4) Lie algebra is used to calculate the evolution of the quadrupolar spin system in the interaction representation in the presence of a pulsed radiofrequency perturbation. The theoretical predictions are compared to experimental observations of the response of the chlorine spin system in polycrystalline and single-crystal samples of the cubic antifluorite, K2OsCl6 at 295 and 77 K. A description of the inhomogeneity involving finite domains of spins with a common strength of the quadrupolar coupling is shown to be successful in accounting for the observations.

  17. Quadrupolar second-harmonic generation by helical beams and vectorial vortices with radial or azimuthal polarization

    NASA Astrophysics Data System (ADS)

    Mandujano, Miguel G.; Maytorena, Jesús A.

    2013-08-01

    We study the optical second-harmonic radiation (SHG) generated by scattering from a homogeneous centrosymmetric thin composite material illuminated by higher-order Gaussian laser beams. The induced second-order source polarization is taken as of quadrupolar type (E·?)E, which depends on the inhomogeneity of the incident electric field E. This nonlinear source has the same form as that responsible of the SH signal observed in a composite made of Si nanocrystals embedded uniformly in a SiO2 matrix and that calculated for a thin disordered array of nanospheres. We calculate the SH radiation angular patterns generated by several incident combinations of spatial modes and states of polarizations. In particular, excitation with radially and azimuthally polarized doughnut modes and helical beams carrying orbital angular momentum with linear or circular polarization are considered. We found that this quadrupolar SHG depends sensitively on the transverse structure and polarization of the driving field. The response to ?E introduces a factor E(E·K) in the Fourier component of the SH scattering amplitude, absent in electric-dipole-allowed SHG, that can give additional nodal lines or rings in the SH angular patterns, changes of the state of polarization, or additional azimuthal phases in the harmonic radiation. For circularly polarized beams with helical phase wave front, we found a selection rule according to which the nonlinear scattering of an optical vortex with charge l? and spin ?=±1 induces a SH vortex field with a spin-dependent charge doubling l2?=2l?+?. These features may be useful to identify SHG processes of quadrupolar nature and suggest a way to produce scattered SH radiation with a desired angular pattern and state of polarization.

  18. Quadrupolar, Triple [Delta]-Function Potential in One Dimension

    ERIC Educational Resources Information Center

    Patil, S. H.

    2009-01-01

    The energy and parity eigenstates for quadrupolar, triple [delta]-function potential are analysed. Using the analytical solutions in specific domains, simple expressions are obtained for even- and odd-parity bound-state energies. The Heisenberg uncertainty product is observed to have a minimum for a specific strength of the potential. The…

  19. The combined effect of quadrupolar and dipolar interactions on the excitation and evolution of triple quantum coherences in ?Li solid state magic angle spinning NMR.

    PubMed

    Eliav, Uzi; Goldbourt, Amir

    2013-05-01

    Magic-angle spinning triple-quantum NMR spectra of lithium-7 provide enhanced spectral dispersion for the inherent low chemical shift range of this nucleus, while maintaining linewidths, which are free of any quadrupolar broadening to first order. Since the quadrupolar interaction of (7)Li is very small, in the order of the radio frequency nutation frequencies and only moderately larger than the spinning rates, such spectra are also only marginally affected by the second order quadrupolar interaction under large magnetic fields. In the current study we demonstrate that the existence of two and more proximate (7)Li spins, as encountered in many materials, affects both excitation and evolution of triple-quantum coherences due to the combined effect of quadrupolar and homonuclear dipolar interactions. We show that the generation of (7)Li triple-quantum coherences using two ?/2 pulses separated by one-half rotor period is superior in such cases to a single pulse excitation since the excitation time is shorter; thus the maximum signal is only marginally affected by the homonuclear dipolar couplings. When the quadrupolar-dipolar cross terms dominate the spectra, single- and triple-quantum lineshapes are very similar and therefore a true gain in dispersion is maintained in the latter spectrum. The effects of quadrupolar-dipolar cross terms are experimentally demonstrated by comparing a natural abundance and a (6)Li-diluted samples of lithium acetate, resulting in the possibility of efficient excitation of triple quantum coherences over longer periods of time, and in longer life times of triple-quantum coherences. PMID:23481861

  20. Effect of an arbitrary spin orientation on the quadrupolar structure of an extended body in a Schwarzschild spacetime

    E-print Network

    Donato Bini; Andrea Geralico

    2014-12-24

    The influence of an arbitrary spin orientation on the quadrupolar structure of an extended body moving in a Schwarzschild spacetime is investigated. The body dynamics is described according to the Mathisson-Papapetrou-Dixon model without any restriction on the motion or simplifying assumption on the associated spin vector and quadrupole tensor, generalizing previous works. The equations of motion are solved analytically in the limit of small values of the characteristic length scales associated with the spin and quadrupole variables with respect to the characteristic length of the background curvature. The solution provides all corrections to the circular geodesic on the equatorial plane taken as the reference trajectory due to both dipolar and quadrupolar structure of the body as well as the conditions which the nonvanishing components of the quadrupole tensor must fulfill in order that the problem be self-consistent.

  1. Quantum phases of quadrupolar Fermi gases in optical lattices.

    PubMed

    Bhongale, S G; Mathey, L; Zhao, Erhai; Yelin, S F; Lemeshko, Mikhail

    2013-04-12

    We introduce a new platform for quantum simulation of many-body systems based on nonspherical atoms or molecules with zero dipole moments but possessing a significant value of electric quadrupole moments. We consider a quadrupolar Fermi gas trapped in a 2D square optical lattice, and show that the peculiar symmetry and broad tunability of the quadrupole-quadrupole interaction results in a rich phase diagram encompassing unconventional BCS and charge density wave phases, and opens up a perspective to create a topological superfluid. Quadrupolar species, such as metastable alkaline-earth atoms and homonuclear molecules, are stable against chemical reactions and collapse and are readily available in experiment at high densities. PMID:25167282

  2. Population transfer HMQC for half-integer quadrupolar nuclei

    NASA Astrophysics Data System (ADS)

    Wang, Qiang; Li, Yixuan; Trébosc, Julien; Lafon, Olivier; Xu, Jun; Hu, Bingwen; Feng, Ningdong; Chen, Qun; Amoureux, Jean-Paul; Deng, Feng

    2015-03-01

    This work presents a detailed analysis of a recently proposed nuclear magnetic resonance method [Wang et al., Chem. Commun. 49(59), 6653-6655 (2013)] for accelerating heteronuclear coherence transfers involving half-integer spin quadrupolar nuclei by manipulating their satellite transitions. This method, called Population Transfer Heteronuclear Multiple Quantum Correlation (PT-HMQC), is investigated in details by combining theoretical analyses, numerical simulations, and experimental investigations. We find that compared to instant inversion or instant saturation, continuous saturation is the most practical strategy to accelerate coherence transfers on half-integer quadrupolar nuclei. We further demonstrate that this strategy is efficient to enhance the sensitivity of J-mediated heteronuclear correlation experiments between two half-integer quadrupolar isotopes (e.g., 27Al-17O). In this case, the build-up is strongly affected by relaxation for small T2' and J coupling values, and shortening the mixing time makes a huge signal enhancement. Moreover, this concept of population transfer can also be applied to dipolar-mediated HMQC experiments. Indeed, on the AlPO4-14 sample, one still observes experimentally a 2-fold shortening of the optimum mixing time albeit with no significant signal gain in the 31P-{27Al} experiments.

  3. Quantum information processing by nuclear magnetic resonance on quadrupolar nuclei.

    PubMed

    Teles, João; DeAzevedo, Eduardo R; Freitas, Jair C C; Sarthour, Roberto S; Oliveira, Ivan S; Bonagamba, Tito J

    2012-10-13

    Nuclear magnetic resonance is viewed as an important technique for the implementation of many quantum information algorithms and protocols. Although the most straightforward approach is to use the two-level system composed of spin 1/2 nuclei as qubits, quadrupolar nuclei, which possess a spin greater than 1/2, are being used as an alternative. In this study, we show some unique features of quadrupolar systems for quantum information processing, with an emphasis on the ability to execute efficient quantum state tomography (QST) using only global rotations of the spin system, whose performance is shown in detail. By preparing suitable states and implementing logical operations by numerically optimized pulses together with the QST method, we follow the stepwise execution of Grover's algorithm. We also review some work in the literature concerning the relaxation of pseudo-pure states in spin 3/2 systems as well as its modelling in both the Redfield and Kraus formalisms. These data are used to discuss differences in the behaviour of the quantum correlations observed for two-qubit systems implemented by spin 1/2 and quadrupolar spin 3/2 systems, also presented in the literature. The possibilities and advantages of using nuclear quadrupole resonance experiments for quantum information processing are also discussed. PMID:22946040

  4. Two-dimensional nuclear magnetic resonance of quadrupolar systems

    SciTech Connect

    Wang, Shuanhu

    1997-09-17

    This dissertation describes two-dimensional nuclear magnetic resonance theory and experiments which have been developed to study quadruples in the solid state. The technique of multiple-quantum magic-angle spinning (MQMAS) is extensively reviewed and expanded upon in this thesis. Specifically, MQMAS is first compared with another technique, dynamic-angle spinning (DAS). The similarity between the two techniques allows us to extend much of the DAS work to the MQMAS case. Application of MQMAS to a series of aluminum containing materials is then presented. The superior resolution enhancement through MQMAS is exploited to detect the five- and six-coordinated aluminum in many aluminosilicate glasses. Combining the MQMAS method with other experiments, such as HETCOR, greatly expands the possibility of the use of MQMAS to study a large range of problems and is demonstrated in Chapter 5. Finally, the technique switching-angle spinning (SAS) is applied to quadrupolar nuclei to fully characterize a quadrupolar spin system in which all of the 8 NMR parameters are accurately determined. This dissertation is meant to demonstrate that with the combination of two-dimensional NMR concepts and new advanced spinning technologies, a series of multiple-dimensional NMR techniques can be designed to allow a detailed study of quadrupolar nuclei in the solid state.

  5. Population transfer HMQC for half-integer quadrupolar nuclei.

    PubMed

    Wang, Qiang; Li, Yixuan; Trébosc, Julien; Lafon, Olivier; Xu, Jun; Hu, Bingwen; Feng, Ningdong; Chen, Qun; Amoureux, Jean-Paul; Deng, Feng

    2015-03-01

    This work presents a detailed analysis of a recently proposed nuclear magnetic resonance method [Wang et al., Chem. Commun. 49(59), 6653-6655 (2013)] for accelerating heteronuclear coherence transfers involving half-integer spin quadrupolar nuclei by manipulating their satellite transitions. This method, called Population Transfer Heteronuclear Multiple Quantum Correlation (PT-HMQC), is investigated in details by combining theoretical analyses, numerical simulations, and experimental investigations. We find that compared to instant inversion or instant saturation, continuous saturation is the most practical strategy to accelerate coherence transfers on half-integer quadrupolar nuclei. We further demonstrate that this strategy is efficient to enhance the sensitivity of J-mediated heteronuclear correlation experiments between two half-integer quadrupolar isotopes (e.g., (27)Al-(17)O). In this case, the build-up is strongly affected by relaxation for small T2' and J coupling values, and shortening the mixing time makes a huge signal enhancement. Moreover, this concept of population transfer can also be applied to dipolar-mediated HMQC experiments. Indeed, on the AlPO4-14 sample, one still observes experimentally a 2-fold shortening of the optimum mixing time albeit with no significant signal gain in the (31)P-{(27)Al} experiments. PMID:25747074

  6. Vanillin-molecularly targeted extraction of stir bar based on magnetic field induced self-assembly of multifunctional Fe3O4@Polyaniline nanoparticles for detection of vanilla-flavor enhancers in infant milk powders.

    PubMed

    Wu, Jinhua; Yang, Zaiyue; Chen, Ning; Zhu, Wanying; Hong, Junli; Huang, Changgao; Zhou, Xuemin

    2015-03-15

    A molecularly imprinted stir bar was constructed based on Fe3O4@Polyaniline nanoparticles with magnetic field-induced self-assembly process. The monomer, methacrylic acid, was pre-assembled into the pre-polymers with vanillin as template by the formation of hydrogen bonds. After that, the magnetic complexes were generated by the hydrogen bonding, the hydrophobic and ?-? interaction between the pre-polymers and Fe3O4@Polyaniline. The complexes were adsorbed on the surface of magnetic stir bar under the magnetic induction, and the coating of vanillin-molecularly imprinted polymers was generated by the one-step copolymerization basing on the cross linking of ethylene glycol dimethacrylate. The molecular imprinting stir bar showed superior selectivity and fast binding kinetics for vanillin, and was used for the enrichment of vanilla-flavor enhancers (vanillin, ethyl maltol and methyl vanillin) in infant milk powders. The results measured by HPLC-UV exhibited good linear ranges of 0.01-100, 0.02-100 and 0.03-100?gmL(-1) with the limit of detection of 2.5-10.0ngmL(-1), and the recoveries were 94.7-98.9%, 82.1-96.7% and 84.5-93.2% with RSD<7.2% for the three enhancers, respectively. PMID:25514645

  7. Quadrupolar Kondo effect in uranium heavy-electron materials?

    NASA Technical Reports Server (NTRS)

    Cox, D. L.

    1987-01-01

    The possibility of an electric quadrupole Kondo effect for a non-Kramers doublet on a uranium (U) ion is a cubic metallic host is demonstrated by model calculations showing a Kondo upturn in the resistivity, universal quenching of the quadrupolar moment, and a heavy-electron anomaly in the electronic specific heat. With inclusion of excited crystal-field levels, some of the unusual magnetic-response data in the heavy-electron superconductor UBe13 may be understood. Structural phase transitions at unprecedented low temperatures may occur in U-based heavy-electron materials.

  8. On the relationship between quadrupolar magnetic field and collisionless reconnection

    SciTech Connect

    Smets, R., E-mail: roch.smets@lpp.polytechnique.fr; Belmont, G. [LPP, University P. and M. Curie, CNRS, Ecole Polytechnique, F-91128 Palaiseau (France); Aunai, N. [IRAP, University Paul Sabatier, F-31028 Toulouse (France); Boniface, C. [CEA/DAM, DIF, F-91297 Arpajon (France); Fuchs, J. [LULI, Ecole Polytechnique, CNRS, CEA, University P. and M. Curie, F-91128 Palaiseau (France)

    2014-06-15

    Using hybrid simulations, we investigate the onset of fast reconnection between two cylindrical magnetic shells initially close to each other. This initial state mimics the plasma structure in High Energy Density Plasmas induced by a laser-target interaction and the associated self-generated magnetic field. We clearly observe that the classical quadrupolar structure of the out-of-plane magnetic field appears prior to the reconnection onset. Furthermore, a parametric study reveals that, with a non-coplanar initial magnetic topology, the reconnection onset is delayed and possibly suppressed. The relation between the out-of-plane magnetic field and the out-of-plane electric field is discussed.

  9. Radio-frequency-mediated dipolar recoupling among half-integer quadrupolar spins

    E-print Network

    Griffin, Robert G.

    Radio-frequency-mediated dipolar recoupling among half-integer quadrupolar spins Marc Baldus quadrupolar spins in the presence of an appropriate radio-frequency field. Experimental and theoretical in close spatial proximity. Unfortunately, most spin-1/2 methods involving radio frequency rf irradiation

  10. Nuclear Magnetic Relaxation in METHYLENE-13 and METHYL-13 Coupled Spin Systems and Variable Angle Spinning Lineshape Analysis for Quadrupolar Nuclei with Half Integer Spins

    NASA Astrophysics Data System (ADS)

    Zheng, Zhiwen

    1992-01-01

    The carbon-13 multiplet spin-lattice relaxation in ^{13}CH_2 and ^{13}CH _3^in systems is studied in detail by various nonselective and selective pulse techniques. Simultaneous fitting of the resulting relaxation curves with various rates and initial conditions allows for the extraction of both auto- and cross-correlated dipolar spectral densities which can provide detailed information on the molecular anisotropic reorientation. In addition, the ^ {13}CH_3 coupled spin relaxation can characterize the methyl internal rotation dynamics. The cross-correlation between the dipolar and chemical shift anisotropy (CSA) interactions is found to be appreciable. Dipolar-CSA cross-correlated spectral densities introduce relaxation pathways that couple together magnetization modes with different spin inversion symmetries. Consideration of the dipolar-CSA cross-correlated spectral densities not only improves the accuracy of the measurement of dipolar spectral densities but also allows for the determination of the dipolar-CSA cross-correlated spectral densities themselves, providing a new measure of the anisotropy of the shielding tensor. NMR spectroscopy of quadrupolar nuclei in solids generally yields broad lines even when magic angle spinning is applied. Broadening of the central transition of quadrupolar nuclei with half integer spins is caused by the anisotropy of the second order quadrupolar interaction. A straightforward approach is presented that combines average Hamiltonian theory and a numerical solution of a classical banded matrix describing the equation of motion for a quadrupolar nucleus under variable angle sample spinning conditions. At either of two fourth rank magic angles, a simple three parameter lineshape is obtained, and the three breakpoints are related directly to the quadrupolar constant and its asymmetry parameter. The banded matrix method used in the simulations is computationally much more efficient than the standard method using Bessel functions.

  11. Fluctuating magnetic field induced resonant activation

    NASA Astrophysics Data System (ADS)

    Mondal, Shrabani; Das, Sudip; Baura, Alendu; Bag, Bidhan Chandra

    2014-12-01

    In this paper, we have studied the properties of a Brownian particle at stationary state in the presence of a fluctuating magnetic field. Time dependence of the field makes the system thermodynamically open. As a signature of that the steady state distribution function becomes function of damping strength, intensity of fluctuations and constant parts of the applied magnetic field. It also depends on the correlation time of the fluctuating magnetic field. Our another observation is that the random magnetic field can induce the resonant activation phenomenon. Here correlation time is increased under the fixed variance of the fluctuating field. But if the correlation time (?) increases under the fixed field strength then the mean first passage time rapidly grows at low ? and it almost converges at other limit. This is sharp contrast to the usual colored noise driven open system case where the mean first passage time diverges exponentially. We have also observed that a giant enhancement of barrier crossing rate occurs particularly at large strength of constant parts of the applied magnetic field even for very weak fluctuating magnetic field. Finally, break down of the Arrhenius result and disappearance of the Kramers' turn over phenomenon may occur in the presence of a fluctuating magnetic field.

  12. Thermodynamics of the Magnetic-Field-Induced \\

    Microsoft Academic Search

    Scott Chandler Riggs

    2010-01-01

    High magnetic fields are used to kill superconductivity and probe what happens to system when it cannot reach the ideal ground state, i.e. what is the normal-state ground state? Early work in High-Tc, where the application of magnetic field destroyed the zero resistance state and recovered a resistivity value that connected continuously with the zero field curve, lead people to

  13. Exotic roton excitations in quadrupolar Bose-Einstein condensates

    E-print Network

    M. Lahrz; Mikhail Lemeshko; L. Mathey

    2014-12-29

    We investigate the occurrence of rotons in a quadrupolar Bose-Einstein condensate confined to two dimensions. Depending on the particle density, the ratio of the contact and quadrupole-quadrupole interactions, and the alignment of the quadrupole moments with respect to the confinement plane, the dispersion relation features two or four point-like roton minima, or one ring-shaped minimum. We map out the entire parameter space of the roton behavior and identify the instability regions. We propose to observe the exotic rotons by monitoring the characteristic density wave dynamics resulting from a short local perturbation, and discuss the possibilities to detect the predicted effects in state-of-the-art experiments with ultracold homonuclear molecules.

  14. Spin Squeezing in a Quadrupolar Nuclei NMR System

    NASA Astrophysics Data System (ADS)

    Auccaise, R.; Araujo-Ferreira, A. G.; Sarthour, R. S.; Oliveira, I. S.; Bonagamba, T. J.; Roditi, I.

    2015-01-01

    We have produced and characterized spin-squeezed states at a temperature of 26 °C in a nuclear magnetic resonance quadrupolar system. The experiment was carried out on 133Cs nuclei of spin I =7 /2 in a sample of lyotropic liquid crystal. The source of spin squeezing was identified as the interaction between the quadrupole moment of the nuclei and the electric field gradients present within the molecules. We use the spin angular momentum representation to describe formally the nonlinear operators that produce the spin squeezing on a Hilbert space of dimension 2 I +1 =8 . The quantitative and qualitative characterization of this spin-squeezing phenomenon is expressed by a squeezing parameter and squeezing angle developed for the two-mode Bose-Einstein condensate system, as well as by the Wigner quasiprobability distribution function. The generality of the present experimental scheme points to potential applications in solid-state physics.

  15. Spin squeezing in a quadrupolar nuclei NMR system.

    PubMed

    Auccaise, R; Araujo-Ferreira, A G; Sarthour, R S; Oliveira, I S; Bonagamba, T J; Roditi, I

    2015-01-30

    We have produced and characterized spin-squeezed states at a temperature of 26?°C in a nuclear magnetic resonance quadrupolar system. The experiment was carried out on 133Cs nuclei of spin I=7/2 in a sample of lyotropic liquid crystal. The source of spin squeezing was identified as the interaction between the quadrupole moment of the nuclei and the electric field gradients present within the molecules. We use the spin angular momentum representation to describe formally the nonlinear operators that produce the spin squeezing on a Hilbert space of dimension 2I+1=8. The quantitative and qualitative characterization of this spin-squeezing phenomenon is expressed by a squeezing parameter and squeezing angle developed for the two-mode Bose-Einstein condensate system, as well as by the Wigner quasiprobability distribution function. The generality of the present experimental scheme points to potential applications in solid-state physics. PMID:25679893

  16. The Percus-Yevick approximation for quadrupolar molecular fluids

    NASA Astrophysics Data System (ADS)

    Singh, Ram Chandra; Mohan Singh, Braj; Ram, Jokhan

    2009-03-01

    The Percus-Yevick integral equation theory has been solved to study the equilibrium and structural properties of quadrupolar Gay-Berne fluids. The method used involves an expansion of angle-dependent functions appearing in the integral equations in terms of spherical harmonics and the harmonic coefficients are obtained by an iterative algorithm. All the terms of harmonic coefficients which involve l indices up to less than or equal to 6 have been considered. Molecules with length-to-breadth ratios 3.0 and 4.0 have been considered and results are reported for different densities, temperatures, and quadrupole moments. The values of pair correlation functions have been compared with the available computer simulation results.

  17. Structural transition and atomic ordering of Ni49.8Mn28.5Ga21.7 ferromagnetic shape memory alloy powders prepared by ball milling

    E-print Network

    Zheng, Yufeng

    Elsevier B.V. All rights reserved. Keywords: NiMnGa; Shape memory alloy; Phase transformations; Crystal promising are the Ni2MnGa alloys, in which magnetic field induced strain as large as several percent hasStructural transition and atomic ordering of Ni49.8Mn28.5Ga21.7 ferromagnetic shape memory alloy

  18. Quadrupolar Effect on Two Layered Thin Film Antiferroelectric Smectic Liquid Crystal

    SciTech Connect

    Lum, Chia-Yuee; Ong, Lye-Hock [School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Cepic, Mojca [Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia, Faculty of Education, University of Ljubljana, Kardeljeva pl. 16. 1000 Ljubljana (Slovenia)

    2011-03-30

    Within the framework of the discrete Landau phenomenological model, the free energy of an antiferroelectric smectic liquid crystal is analyzed. This model considers the interactions between the liquid crystal molecules within the nearest and the next nearest layers. Electrostatic quadrupolar interaction up to the nearest layers is included. This quadrupolar term, b{sub q{xi}}???{sub i{center_dot}{xi}}???{sub i+1}{sup 2} is positive, thus favouring a perpendicular orientation in the adjacent layer respectively. We show how quadrupolar interaction can affects the planar regions of the phase diagram of a two layered thin antiferroelectric smectic liquid crystal film.

  19. A 3D experiment that provides isotropic homonuclear correlations of half-integer quadrupolar nuclei

    NASA Astrophysics Data System (ADS)

    Iuga, Dinu; Holland, Diane; Dupree, Ray

    2014-09-01

    Two 3D experiments, capable of producing enhanced resolution two-spin double-quantum (DQ) homonuclear correlations for half-integer quadrupolar nuclei, are described. The first uses a split-t1 MQMAS sequence followed by a sandwiched oR3 symmetry-based dipolar recoupling sequence to directly excite DQ coherences. In this case an isotropic single-quantum (SQ) coherence starts the homonuclear DQ excitation. In the second experiment a single strong pulse is used to create triple quantum (TQ) coherence followed by a further single pulse conversion to zero-order before a non-sandwiched oR3 DQ sequence. The first experiment is demonstrated using 87Rb in RbNO3, with three Rb sites in a ?5 ppm range, and the second to 11B in caesium triborate, CsB3O5, with two three-coordinated sites separated by ?2 ppm and one four-coordinated boron site. In both cases, all sites are clearly resolved and their connections observed. The second experiment has higher sensitivity and a good signal to noise is obtained in a reasonable time despite the long T1 relaxation time of 11B in this material.

  20. Gravitational quadrupolar coupling to equivalence principle test masses: the general case

    NASA Astrophysics Data System (ADS)

    Lockerbie, N. A.

    2002-04-01

    This paper discusses the significance of the quadrupolar gravitational force in the context of test masses destined for use in equivalence principle (EP) experiments, such as STEP and MICROSCOPE. The relationship between quadrupolar gravity and rotational inertia for an arbitrary body is analysed, and the special, gravitational, role of a body's principal axes of inertia is revealed. From these considerations the gravitational quadrupolar force acting on a cylindrically symmetrical body, due to a point-like attracting source mass, is derived in terms of the body's mass quadrupole tensor. The result is shown to be in agreement with that obtained from MacCullagh's formula (as the starting point). The theory is then extended to cover the case of a completely arbitrary solid body, and a compact formulation for the quadrupolar force on such a body is derived. A numerical example of a dumb-bell's attraction to a local point-like gravitational source is analysed using this theory. Close agreement is found between the resulting quadrupolar force on the body and the difference between the net and the monopolar forces acting on it, underscoring the utility of the approach. A dynamical technique for experimentally obtaining the mass quadrupole tensors of EP test masses is discussed, and a means of validating the results is noted.

  1. Quadrupolar spectra of nuclear spins in strained InGaAs quantum dots

    E-print Network

    Ceyhun Bulutay

    2012-05-01

    Self-assembled quantum dots (QDs) are born out of lattice mismatched ingredients where strain plays an indispensable role. Through the electric quadrupolar coupling, strain affects the magnetic environment as seen by the nuclear spins. To guide prospective single-QD nuclear magnetic resonance (NMR) as well as dynamic nuclear spin polarization experiments, an atomistic insight to the strain and quadrupolar field distributions is presented. A number of implications of the structural and compositional profile of the QD have been identified. A high aspect ratio of the QD geometry enhances the quadrupolar interaction. The inclined interfaces introduce biaxiality and the tilting of the major quadrupolar principal axis away from the growth axis; the alloy mixing of gallium into the QD enhances both of these features while reducing the quadrupolar energy. Regarding the NMR spectra, both Faraday and Voigt geometries are investigated, unraveling in the first place the extend of inhomogeneous broadening and the appearance of the normally-forbidden transitions. Moreover, it is shown that from the main extend of the NMR spectra the alloy mole fraction of a single QD can be inferred. By means of the element-resolved NMR intensities it is found that In nuclei has a factor of five dominance over those of As. In the presence of an external magnetic field, the borderlines between the quadrupolar and Zeeman regimes are extracted as 1.5 T for In and 1.1 T for As nuclei. At these values the nuclear spin depolarization rates of the respective nuclei get maximized due to the noncollinear secular hyperfine interaction with a resident electron in the QD.

  2. AB initio calculations of 2H and 14N quadrupolar coupling constants in hydrogen bonded dimers

    NASA Astrophysics Data System (ADS)

    Pettitt, Brian A.; Boyd, Russell J.; Edgecombe, Kenneth E.

    1982-07-01

    SCF MO calculations at the 6-31G ** level of approximation are reported for 2H and 14N electric field gradients in HCN⋯HCN, HCN⋯HF, and CH 3CN⋯HF dimers, with emphasis on the configurational dependence of these quantities in (HCN) 2. In comparison with available experimental nuclear quadrupolar coupling constants, the calculated values for the monomers and dimers exhibit an accuracy of ? 10%, which is comparable to that of other spectroscopic parameters. The implications of hydrogen bonding for quadrupolar spin-lattice relaxation rates are briefly discussed.

  3. Conformational response of the phosphatidylcholine headgroup to bilayer surface charge: torsion angle constraints from dipolar and quadrupolar couplings in bicelles.

    PubMed

    Semchyschyn, Darlene J; Macdonald, Peter M

    2004-02-01

    The effects of bilayer surface charge on the conformation of the phosphocholine group of phosphatidylcholine were investigated using a torsion angle analysis of quadrupolar and dipolar splittings in, respectively, (2)H and (13)C NMR spectra of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) labelled in the phosphocholine group with either deuterons (POPC-alpha-d(2), POPC-beta-d(2) and POPC-gamma-d(9)) or carbon-13 (POPC-alpha-(13)C and POPC-alphabeta-(13)C(2)) and incorporated into magnetically aligned bicelles containing various amounts of either the cationic amphiphile 1,2-dimyristoyl-3-trimethylammoniumpropane (DMTAP) or the anionic amphiphile 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol (DMPG). Three sets of quadrupolar splittings, one from each of the three deuteron labelling positions, and three sets of dipolar splittings ((13)C(alpha)-(31)P, (13)C(alpha)-(13)C(beta), (13)C(beta)-(14)N), were measured at each surface charge, along with the (31)P residual chemical shift anisotropy. The torsion angle analysis assumed fast anisotropic rotation of POPC about its long molecular axis, thus projecting all NMR interactions onto that director axis of motion. Dipolar, quadrupolar and chemical shift anisotropies were calculated as a function of the phosphocholine internal torsion angles by first transforming into a common reference frame affixed to the phosphocholine group prior to motional averaging about the director axis. A comparison of experiment and calculation provided the two order parameters specifying the director orientation relative to the molecule, plus the torsion angles alpha(3), alpha(4) and alpha(5). Surface charge was found to have little effect on the torsion angle alpha(5) (rotations about C(alpha)-C(beta)), but to have large and inverse effects on torsion angles alpha(3) [rotations about P-O(11)] and alpha(4) [rotations about O(11)-C(alpha)], yielding a net upwards tilt of the P-N vector in the presence of cationic surface charge, and a downwards tilt in the presence of anionic surface charge, relative to neutrality. PMID:14745788

  4. Nuclear magnetic relaxation in [sup 13]CH[sub 2] and [sup 13]CH[sub 3] coupled spin systems and variable angle spinning lineshape analysis for quadrupolar nuclei with half integer spins

    SciTech Connect

    Zheng, Z.

    1992-01-01

    The carbon-13 multiplet spin-lattice relaxation in [sup 13]CH[sub 2] and [sup 13]CH[sub 3] spin systems is studied in detail by various nonselective and selective pulse techniques. Simultaneous fitting of the resulting relaxation curves with various rates and initial conditions allows for the extraction of both auto- and cross-correlated dipolar spectral densities which can provide detailed information on the molecular anisotropic reorientation. In addition, the [sup 13]CH[sub 3] coupled spin relaxation can characterize the methyl internal rotation dynamics. The cross-correlation between the dipolar and chemical shift anisotropy (CSA) interactions is found to be appreciable. Dipolar-CSA cross-correlated spectral densities introduce relaxation pathways that couple together magnetization modes with different spin inversion symmetries. Consideration of the dipolar-CSA cross-correlated spectral densities not only improves the accuracy of the measurement of dipolar spectral densities but also allows for the determination of the dipolar-CSA cross-correlated spectral densities themselves, providing a new measure of the anisotropy of the shielding tensor. NMR spectroscopy of quadrupolar nuclei in solids generally yields broad lines even when magic angle spinning is applied. Broadening of the central transition of quadrupolar nuclei with half integer spins is caused by the anisotropy of the second order quadrupolar interaction. A straightforward approach is presented that combines average Hamiltonian theory and a numerical solution of a classical banded matrix describing the equation of motion for a quadrupolar nucleus under variable angle sample spinning conditions. At either of two fourth rank magic angles, a simple three parameter lineshape is obtained, and the three breakpoints are related directly to the quadrupolar constant and its asymmetry parameter.

  5. Benzene quadrupolarity and arene-arene interactions Zhengyu Wu and Rainer Glaser*

    E-print Network

    Glaser, Rainer

    1 Benzene quadrupolarity and arene-arene interactions Zhengyu Wu and Rainer Glaser* Department in employing benzenes as lateral synthons in crystal engineering. We recently synthesized a series of perfectly organic NLO crystals. The benzene-benzene T-contact plays a critical role in stabilizing the crystal

  6. Long-Range Electron Binding to Quadrupolar Molecules C. Desfrancois, Y. Bouteiller, and J. P. Schermann

    E-print Network

    Simons, Jack

    Long-Range Electron Binding to Quadrupolar Molecules C. Desfranc¸ois, Y. Bouteiller, and J. P electron can be bound to a molecule in a very diffuse orbital as a result of the long-range contributions be trapped in the molecular potential well essentially created by the long-range at- tractive fields plus

  7. Long-range electron binding to quadrupolar molecules C. Desfranois,1

    E-print Network

    Boyer, Edmond

    Long-range electron binding to quadrupolar molecules C. Desfrançois,1 Y. Bouteiller,1 J, Tennessee, 37996 An excess electron can be bound to a molecule in a very diffuse orbital as a result electron affinities of 20 and 138 meV, respectively. PACS numbers: 3315. Ry, 3360-q, 3460+z #12;An excess

  8. Indirect measurement of N-14 quadrupolar coupling for NH3 intercalated in potassium graphite

    NASA Technical Reports Server (NTRS)

    Tsang, T.; Fronko, R. M.; Resing, H. A.

    1987-01-01

    A method for indirect measurement of the nuclear quadrupolar coupling was developed and applied to NH3 molecules in the graphite intercalation compound K(NH3)4.3C24, which has a layered structure with alternating carbon and intercalant layers. Three triplets were observed in the H-1 NMR spectra of the compound. The value of the N-14 quadrupolar coupling constant of NH3 (3.7 MHz), determined indirectly from the H-1 NMR spectra, was intermediate between the gas value of 4.1 MHz and the solid-state value of 3.2 MHz. The method was also used to deduce the (H-1)-(H-1) and (N-14)-(H-1) dipolar interactions, the H-1 chemical shifts, and the molecular orientations and motions of NH3.

  9. Two-dimensional one-component plasma in a quadrupolar field

    Microsoft Academic Search

    P. J. Forrester; B. Jancovici

    1995-01-01

    The classical two-dimensional one-component plasma is an exactly solvable\\u000amodel, at some special temperature, even when the one-body potential acting on\\u000athe particles has a quadrupolar term. As a supplement to a recent work of Di\\u000aFrancesco, Gaudin, Itzykson, and Lesage [{\\\\it Int. J. Mod. Phys.} {\\\\bf A9},\\u000a4257 (1994)] about an $N$-particle system ($N$ large but finite), a macroscopic

  10. Cross polarization from (1)H to quadrupolar (6)Li nuclei for dissolution DNP.

    PubMed

    Perez Linde, Angel J; Bornet, Aurélien; Milani, Jonas; Vuichoud, Basile; Melzi, Roberto; Jannin, Sami; Bodenhausen, Geoffrey

    2014-12-01

    Cross polarization from protons to quadrupolar (6)Li nuclei is combined with dynamic nuclear polarization of protons at 1.2 K and 6.7 T using TEMPOL as a polarizing agent followed by rapid dissolution. Compared to direct (6)Li DNP without cross-polarization, a higher nuclear spin polarization P((6)Li) can be obtained in a shorter time. A double resonance (1)H-(6)Li probe was designed that is equipped for Longitudinally Detected Electron Spin Resonance. PMID:25319311

  11. Photoinduced symmetry-breaking intramolecular charge transfer in a quadrupolar pyridinium derivative.

    PubMed

    Carlotti, Benedetta; Benassi, Enrico; Spalletti, Anna; Fortuna, Cosimo G; Elisei, Fausto; Barone, Vincenzo

    2014-07-21

    We report here a joint experimental and theoretical study of a quadrupolar, two-branched pyridinium derivative of interest as a potential non-linear optical material. The spectral and photophysical behaviour of this symmetric system is greatly affected by the polarity of the medium. A very efficient photoinduced intramolecular charge transfer, surprisingly more efficient than in the dipolar asymmetric analogue, is found to occur by femtosecond resolved transient absorption spectroscopy. TD-DFT calculations are in excellent agreement with these experimental findings and predict large charge displacements in the molecular orbitals describing the ground state and the lowest excited singlet state. The theoretical study also revealed that in highly polar media the symmetry of the excited state is broken giving a possible explanation to the fluorescence and transient absorption spectra resembling those of the one-branched analogous compound in the same solvents. The present study may give an important insight into the excited state deactivation mechanism of cationic (donor-?-acceptor-?-donor)(+) quadrupolar compounds characterised by negative solvatochromism, which are expected to show significant two-photon absorption (TPA). Moreover, the water solubility of the investigated quadrupolar system may represent an added value in view of the most promising applications of TPA materials in biology and medicine. PMID:24898848

  12. Close-packed two-dimensional silver nanoparticle arrays: quadrupolar and dipolar surface plasmon resonance coupling.

    PubMed

    Yun, Sukang; Hong, Soonchang; Acapulco, Jesus A I; Jang, Ho Young; Ham, Songyi; Lee, Kyungeun; Kim, Seong Kyu; Park, Sungho

    2015-04-13

    Silver nanoparticles (NPs) ranging in size from 40 to 100?nm were prepared in high yield by using an improved seed-mediated method. The homogeneous Ag?NPs were used as building blocks for 2D assembled Ag?NP arrays by using an oil/water interface. A close-packed 2D array of Ag?NPs was fabricated by using packing molecules (3-mercaptopropyltrimethoxysilane) to control the interparticle spacing. The homogeneous 2D Ag?NP array exhibited a strong quadrupolar cooperative plasmon mode resonance and a dipolar red-shift relative to individual Ag?NPs suspended in solution. A well-arranged 2D Ag?NP array was embedded in polydimethylsiloxane film and, with biaxial stretching to control the interparticle distance, concomitant variations of the quadrupolar and dipolar couplings were observed. As the interparticle distance increased, the intensity of the quadrupolar cooperative plasmon mode resonance decreased and dipolar coupling completely disappeared. The local electric field of the 2D Ag?NP array was calculated by using finite difference time domain simulation and qualitatively showed agreement with the experimental measurements. PMID:25739448

  13. Nuclear magnetic resonance studies of quadrupolar nuclei and dipolar field effects

    SciTech Connect

    Urban, Jeffry Todd

    2004-12-21

    Experimental and theoretical research conducted in two areas in the field of nuclear magnetic resonance (NMR) spectroscopy is presented: (1) studies of the coherent quantum-mechanical control of the angular momentum dynamics of quadrupolar (spin I > 1/2) nuclei and its application to the determination of molecular structure; and (2) applications of the long-range nuclear dipolar field to novel NMR detection methodologies.The dissertation is organized into six chapters. The first two chapters and associated appendices are intended to be pedagogical and include an introduction to the quantum mechanical theory of pulsed NMR spectroscopy and the time dependent theory of quantum mechanics. The third chapter describes investigations of the solid-state multiple-quantum magic angle spinning (MQMAS) NMR experiment applied to I = 5/2 quadrupolar nuclei. This work reports the use of rotary resonance-matched radiofrequency irradiation for sensitivity enhancement of the I = 5/2 MQMAS experiment. These experiments exhibited certain selective line narrowing effects which were investigated theoretically.The fourth chapter extends the discussion of multiple quantum spectroscopy of quadrupolar nuclei to a mostly theoretical study of the feasibility of enhancing the resolution of nitrogen-14 NMR of large biomolecules in solution via double-quantum spectroscopy. The fifth chapter continues to extend the principles of multiple quantum NMR spectroscopy of quadrupolar nuclei to make analogies between experiments in NMR/nuclear quadrupolar resonance (NQR) and experiments in atomic/molecular optics (AMO). These analogies are made through the Hamiltonian and density operator formalism of angular momentum dynamics in the presence of electric and magnetic fields.The sixth chapter investigates the use of the macroscopic nuclear dipolar field to encode the NMR spectrum of an analyte nucleus indirectly in the magnetization of a sensor nucleus. This technique could potentially serve as an encoding module for the recently developed NMR remote detection experiment. The feasibility of using hyperpolarized xenon-129 gas as a sensor is discussed. This work also reports the use of an optical atomic magnetometer to detect the nuclear magnetization of Xe-129 gas, which has potential applicability as a detection module for NMR remote detection experiments.

  14. Magnetic field-induced electric quadrupole moment in the ground state of the relativistic hydrogen-like atom: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function

    Microsoft Academic Search

    Radoslaw Szmytkowski; Patrycja Stefanska

    2011-01-01

    We consider a Dirac one-electron atom placed in a weak, static, uniform magnetic field. We show that, to the first order in the strength $B$ of the perturbing field, the only electric multipole moment induced by the field in the ground state of the atom is the quadrupole one. Using the Sturmian expansion of the generalized Dirac-Coulomb Green function [R.

  15. A Conduction Cooled High Temperature Superconductor Quadrupolar Superferric Magnet, Design and Construction

    NASA Astrophysics Data System (ADS)

    Dobrin, I.; Morega, A. M.; Nedelcu, A.; Morega, M.; Neamtu, J.

    2014-05-01

    The paper presents the prototype of an YBCO superferric quadrupolar magnet for high gradient magnetic field generation, design and construction. The temperature of the superconducting coil has to be kept within safe limits or the HTS would exit the superconductive state. Of particular concern is the "warm" beam tube that passes through the magnet. Cryogenic conduction cooling with a closed cycle G-M Cooler may ensure the removal of the ambient heat influx. Numerical simulation results on the magnetic field and heat transfer problems are then discussed. The computational domain is abstracted out of the CAD design of the system. The design solution is presented and compared with the numerical simulations results.

  16. Lineshapes of a Spin- {1}/{2} Nucleus with Scalar Coupling to a Quadrupolar Nucleus Subject to Random Field Relaxation

    NASA Astrophysics Data System (ADS)

    Kofod, Pauli

    The lineshapes in solution of a spin- {1}/{2} nucleus with scalar coupling to one quadrupolar nucleus which is subject to random-field relaxation have been calculated using a relaxation matrix treatment. For the case of the quadrupolar nucleus having I= 1, a lineshape expression has been derived. For I> 1, lineshapes have been calculated numerically. As an example of the use of these calculations, the 13C NMR spectra of the hexacyanocobaltate(III) anion in aqueous solution were recorded at various temperatures and these spectra were simulated invoking contributions from both quadrupolar relaxation and spin-rotation relaxation to the total spin-lattice relaxation rate of the 59Co nucleus. At 360 K, spin-rotation relaxation constitutes 28% of the total 59Co nuclear relaxation rate.

  17. Multi-rank nuclear magnetic resonance studies of half-integer quadrupolar nuclei in solids by three-dimensional dynamic-angle

    E-print Network

    Frydman, Lucio

    Multi-rank nuclear magnetic resonance studies of half-integer quadrupolar nuclei in solids by three-integer quadrupolar nuclei in solids. The method is based on the multi-rank expansion of the high-field NMR, as well as by second- and fourth-rank anisotropies depending on the principal values and relative

  18. Magnetic-field-induced intermittency in spin-wave experiments

    NASA Astrophysics Data System (ADS)

    de Aguiar, Flavio M.; Azevedo, Antonio; Rezende, Sergio M.

    1993-05-01

    Chaotic behavior in spin-wave systems is usually observed with the variation of the driving parameter, namely, the incident microwave power. A variety of interesting phenomena can occur if one keeps the power fixed beyond the auto-oscillation threshold and varies another available parameter. We demonstrate this with X-band subsidiary-resonance experiments in an yttrium iron garnet (YIG) sphere with varying dc magnetic field. Besides period-doubling bifurcations, intermittent temporal bursting resulting from the collision of neighbouring period-I and chaotic attractors has been observed. These phenomena are qualitatively investigated in the light of the theory of crisis in dissipative systems due to Grebogi, Ott, Romeiras, and Yorke. In addition, for fixed magnetic field and varying microwave power, we observe that transient periods prior to auto-oscillation have a power-law dependence on the driving parameter, similarly to crisis-induced phenomena at higher power levels.

  19. Magnetic field-induced alignment of steel microstructures

    Microsoft Academic Search

    K. Maruta; M. Shimotomai

    2002-01-01

    It is well established that dipolar interactions in colloidal magnetic fluids are the mechanism of the pattern formation such as chains or columns. We report the first observation of structure formation in steels exposed to a magnetic field. A magnetic field higher than 2T is found to align the microstructure of steels parallel to the field during the transformation from

  20. Magnetic field induced differential neutron phase contrast imaging

    SciTech Connect

    Strobl, M.; Treimer, W.; Walter, P.; Keil, S.; Manke, I. [Department of Physical Chemistry, Ruprecht Karls University Heidelberg, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany and Hahn-Meitner Institute Berlin, SF1, Glienickerstr. 100, 14109 Berlin (Germany); Hahn-Meitner Institute Berlin, Glienickerstr. 100, 14109 Berlin, Germany and University of Applied Sciences (TFH) Berlin, Luxemburger Str. 10, 13353 Berlin (Germany); Hahn-Meitner Institute Berlin, Glienickerstr. 100, 14109 Berlin (Germany)

    2007-12-17

    Besides the attenuation of a neutron beam penetrating an object, induced phase changes have been utilized to provide contrast in neutron and x-ray imaging. In analogy to differential phase contrast imaging of bulk samples, the refraction of neutrons by magnetic fields yields image contrast. Here, it will be reported how double crystal setups can provide quantitative tomographic images of magnetic fields. The use of magnetic air prisms adequate to split the neutron spin states enables a distinction of field induced phase shifts and these introduced by interaction with matter.

  1. On magnetic-field-induced dissipationless electric current in nanowires

    E-print Network

    M. N. Chernodub

    2013-05-15

    We propose a general design of a metallic double-nanowire structure which may support an equilibrium dissipationless electric current in the presence of magnetic field. The structure consists of a compact wire element of a specific shape, which is periodically extended in one spatial dimension. Topologically, each wire element is equivalent to a ring, which supports a dissipationless current in the presence of magnetic flux similarly to the persistent electric current in a normal metal nanoring. Geometrically, each wire element breaks spatial inversion symmetry so that the equilibrium electric current through the device becomes nonzero. We also argue that the same effect should exist in long planar chiral nanoribbons subjected to external magnetic field.

  2. Magnetic-field induced screening effect and collective excitations

    SciTech Connect

    Fukushima, Kenji [Department of Physics, Keio University, Kanagawa 223-8522 (Japan)

    2011-06-01

    We explicitly construct the fermion propagator in a magnetic field background B to take the lowest Landau-level approximation. We analyze the energy and momentum dependence in the polarization tensor and discuss the collective excitations. We find there appear two branches of collective modes in one of two transverse gauge particles; one represents a massive and attenuated gauge particle and the other behaves similar to the zero sound at finite density.

  3. High-order Ho multipoles in HoB2C2 observed with soft resonant x-ray diffraction.

    PubMed

    Princep, A J; Mulders, A M; Schierle, E; Weschke, E; Hester, J; Hutchison, W D; Tanaka, Y; Terada, N; Narumi, Y; Nakamura, T

    2012-02-22

    Soft resonant x-ray Bragg diffraction (SRXD) at the Ho M4,5 edges has been used to study Ho 4f multipoles in the combined magnetic and orbitally ordered phase of HoB2C2. A full description of the energy dependence for both ? and ? incident x-rays at two different azimuthal angles, as well as the ratio I(?)/I(?) as a function of azimuthal angle for a selection of energies, allows a determination of the higher order multipole moments of rank 1 (dipole) to 6 (hexacontatetrapole). The Ho 4f multipole moments have been estimated, indicating a dominant hexadecapole (rank 4) order with an almost negligible influence from either the dipole or the octupole magnetic terms. The analysis incorporates both the intra-atomic magnetic and quadrupolar interactions between the 3d core and 4f valence shells as well as the interference of contributions to the scattering that behave differently under time reversal. Comparison of SRXD, neutron diffraction and non-resonant x-ray diffraction shows that the magnetic and quadrupolar order parameters are distinct. The (00½) component of the magnetic order exhibits a Brillouin type increase below the orbital ordering temperature T(Q), while the quadrupolar order increases more sharply. We conclude that the quadrupolar interaction is strong, but quadrupolar order only occurs when the magnetic order gives rise to a quasi-doublet ground state, which results in a lock-in of the orbitals at T(Q). PMID:22301486

  4. Hydrogen atom in the presence of uniform magnetic and quadrupolar electric fields: Integrability, bifurcations, and chaotic behavior

    Microsoft Academic Search

    M. Iñarrea; J. P. Salas; V. Lanchares

    2002-01-01

    We investigate the classical dynamics of a hydrogen atom in the presence of uniform magnetic and quadrupolar electric fields. After some reductions, the system is described by a two degree of freedom Hamiltonian depending on two parameters. On the one hand, it depends on the z component of the canonical angular momentum Pphi, which is an integral because the system

  5. Complete description of the interactions of a quadrupolar nucleus with a radiofrequency field. Implications for data fitting.

    PubMed

    Spencer, T Leigh; Goward, Gillian R; Bain, Alex D

    2013-06-01

    We present a theory, with experimental tests, that treats exactly the effect of radiofrequency (RF) fields on quadrupolar nuclei, yet retains the symbolic expressions as much as possible. This provides a mathematical model of these interactions that can be easily connected to state-of-the-art optimization methods, so that chemically-important parameters can be extracted from fits to experimental data. Nuclei with spins >1/2 typically experience a Zeeman interaction with the (possibly anisotropic) local static field, a quadrupole interaction and are manipulated with RF fields. Since RF fields are limited by hardware, they seldom dominate the other interactions of these nuclei and so the spectra show unusual dependence on the pulse width used. The theory is tested with (23)Na NMR nutation spectra of a single crystal of sodium nitrate, in which the RF is comparable with the quadrupole coupling and is not necessarily on resonance with any of the transitions. Both the intensity and phase of all three transitions are followed as a function of flip angle. This provides a more rigorous trial than a powder sample where many of the details are averaged out. The formalism is based on a symbolic approach which encompasses all the published results, yet is easily implemented numerically, since no explicit spin operators or their commutators are needed. The classic perturbation results are also easily derived. There are no restrictions or assumptions on the spin of the nucleus or the relative sizes of the interactions, so the results are completely general, going beyond the standard first-order treatments in the literature. PMID:23611427

  6. Method to determine the optimal layer number for the quadrupolar fiber coil

    NASA Astrophysics Data System (ADS)

    Gao, Zhongxing; Zhang, Yonggang; Gao, Wei

    2014-08-01

    For a high precision interferometric fiber optic gyroscope (IFOG) under temperature control, a short start-up time and small temperature drift are important for its applications. The start-up time and the temperature drift of IFOG with the same fiber length but with a different fiber coil layer number are investigated and compared. Simulation by finite difference time domain method is done to illustrate the existence of optimal layer number for the fiber coil wound by the quadrupolar method. Theoretical analysis is then provided and a closed-form formulation is given to calculate the optimal layer number of the fiber coil, which can effectively reduce both the start-up time and temperature drift of IFOG. Our study is meaningful in improving the thermal performance of the fiber coil.

  7. Solid-state STRAFI NMR probe for material imaging of quadrupolar nuclei

    NASA Astrophysics Data System (ADS)

    Tang, Joel A.; Zhong, Guiming; Dugar, Sneha; Kitchen, Jason A.; Yang, Yong; Fu, Riqiang

    2012-12-01

    Stray field imaging (STRAFI) has provided an alternative imaging method to study solid materials that are typically difficult to obtain using conventional MRI methods. For small volume samples, image resolution is a challenge since extremely strong gradients are required to examine narrow slices. Here we present a STRAFI probe for imaging materials with quadrupolar nuclei. Experiments were performed on a 19.6 T magnet which has a fringe field gradient strength of 72 T/m, nearly 50 times stronger than commercial microimagers. We demonstrate the ability to acquire 7Li 1D profiles of liquid and solid state lithium phantoms with clearly resolved features in the micrometer scale and as a practical example a Li ion battery electrode material is also examined.

  8. From bipolar to quadrupolar - The collimation processes of the Cepheus A outflow

    NASA Technical Reports Server (NTRS)

    Torrelles, Jose M.; Verdes-Montenegro, Lourdes; Ho, Paul T. P.; Rodriguez, Luis F.; Canto, Jorge

    1993-01-01

    Results of new K-band observations of the (1, 1) and (2, 2) ammonia lines toward Cepheus A are reported. The lines are mapped with approximately 2 arcsec of angular resolution and 0.3 km/s of velocity resolution. A sensitivity of 10 mJy has been achieved. The observations reveal details of the spatial and kinematics structure of the ambient high-density gas. It is suggested that the interstellar high-density gas is diverting and redirecting the outflow in the sense that the quadrupolar structure of the molecular outflow is produced by the interaction with the ammonia condensationss, with Cep A-1 and Cep A-3 splitting in two halves, respectively the blue- and redshifted lobes of an east-west bipolar molecular outflow.

  9. Pulmonary MRI contrast using Surface Quadrupolar Relaxation (SQUARE) of hyperpolarized 83Kr?

    PubMed Central

    Six, Joseph S.; Hughes-Riley, Theodore; Lilburn, David M.L.; Dorkes, Alan C.; Stupic, Karl F.; Shaw, Dominick E.; Morris, Peter G.; Hall, Ian P.; Pavlovskaya, Galina E.; Meersmann, Thomas

    2014-01-01

    Hyperpolarized 83Kr has previously been demonstrated to enable MRI contrast that is sensitive to the chemical composition of the surface in a porous model system. Methodological advances have lead to a substantial increase in the 83Kr hyperpolarization and the resulting signal intensity. Using the improved methodology for spin exchange optical pumping of isotopically enriched 83Kr, internal anatomical details of ex vivo rodent lung were resolved with hyperpolarized 83Kr MRI after krypton inhalation. Different 83Kr relaxation times were found between the main bronchi and the parenchymal regions in ex vivo rat lungs. The T1 weighted hyperpolarized 83Kr MRI provided a first demonstration of surface quadrupolar relaxation (SQUARE) pulmonary MRI contrast. PMID:24144493

  10. Pulmonary MRI contrast using Surface Quadrupolar Relaxation (SQUARE) of hyperpolarized (83)Kr.

    PubMed

    Six, Joseph S; Hughes-Riley, Theodore; Lilburn, David M L; Dorkes, Alan C; Stupic, Karl F; Shaw, Dominick E; Morris, Peter G; Hall, Ian P; Pavlovskaya, Galina E; Meersmann, Thomas

    2014-01-01

    Hyperpolarized (83)Kr has previously been demonstrated to enable MRI contrast that is sensitive to the chemical composition of the surface in a porous model system. Methodological advances have lead to a substantial increase in the (83)Kr hyperpolarization and the resulting signal intensity. Using the improved methodology for spin exchange optical pumping of isotopically enriched (83)Kr, internal anatomical details of ex vivo rodent lung were resolved with hyperpolarized (83)Kr MRI after krypton inhalation. Different (83)Kr relaxation times were found between the main bronchi and the parenchymal regions in ex vivo rat lungs. The T1 weighted hyperpolarized (83)Kr MRI provided a first demonstration of surface quadrupolar relaxation (SQUARE) pulmonary MRI contrast. PMID:24144493

  11. Triplet superconductivity through quadrupolar exciton exchange in PrOs 4Sb 12

    NASA Astrophysics Data System (ADS)

    Thalmeier, P.

    2006-05-01

    Superconducting pair formation in heavy fermion (HF) compounds is usually attributed to the exchange of over-damped bosonic spin fluctuation modes in the itinerant quasiparticle system. A different mechanism based on the exchange of propagating CEF excitations, i.e., magnetic excitons has previously been identified for UPd 2Al 3 [Sato, et al., Nature 410 (2001) 340; McHale, et al., Phys. Rev. B 70 (2004) 014513]. We propose a similar model for the tetrahedral (T h) HF superconductor PrOs 4Sb 12. There low energy singlet-triplet CEF excitations exist which disperse into quadrupolar exciton bands as observed in inelastic neutron scattering (INS). Virtual exchange of these collective modes due to aspherical Coulomb scattering leads to Cooper pair formation. Calculations of the effective pairing interactions in non-retarded weak coupling approximation for the irreducible T h channels are presented. The triplet T u symmetry is favored for the gap function.

  12. JOURNAL OF MAGNETIC RESONANCE 58,62-75 (1984) The Quadrupolar Spectrum of a Spin I = 1 in a Lipid Bilayer

    E-print Network

    Brown, Michael F.

    JOURNAL OF MAGNETIC RESONANCE 58,62-75 (1984) The Quadrupolar Spectrum of a Spin I = 1 in a Lipid-2364184 $3.00 Copyright Q 1984 by Academic Press, Inc. All rights of reproduction in any form reserved. 62

  13. NMR of group 2 element quadrupolar nuclei and some applications in materials science and biology

    NASA Astrophysics Data System (ADS)

    Li, Xiaohua

    1999-11-01

    For many years, NMR has provided an easy access for chemists to perform structural and kinetic studies on a whole variety of systems. To a great extent, these investigations have been restricted to non-quadrupolar nuclei. The study of quadrupolar nuclei (I > 1/2) offers the potential to gain insight into important problems in material science and biology. In addition to the large quadrupole moment associated with the spin active nuclei of interest, several of the most interesting species also possess an extremely low natural abundance. My recent research focuses on 87Sr NMR, which has been cited by earlier workers as being limited to only ionic species. Several strontium-containing compounds have been synthesized and characterized by single crystal x-ray diffraction. 87Sr NMR signals were determined for these compounds in a series of aprotic polar solvents. The chemical shift variation was found to be consistent with linen free energy relationship, which can be very useful in helping to elucidate mechanism, in predicting reaction rates, and the extent of reaction at equilibrium, and in discovering under what conditions a change in mechanism occurs. Control over symmetry of the compound was found to be the key to obtain the good NMR signals. One application of the new technique that has been developed was in the area of material science. An observation relative to sol-gel derived ionic conductors (La0.8Sr0.2Co0.8Fe0.2O 3.2) was that films often formed cracks upon pyrolysis. By careful examination of the sol-gel process by 87Sr NMR, a model for the structure of the sol was developed. Through the relaxation rate study of the strontium sites, the polymerization mechanism was determined to be predominantly bimolecular within the concentration region studied. The kinetic study of the fast cation exchange between two strontium sites indicated that the inhomogeneity of the polymeric network lads to the film cracking during pyrolysis. As a consequence of understanding the fundamental coordination chemistry of strontium present in the sol, the homogeneity of the ceramic was substantially enhanced, and the resulting electronic properties were improved. In another application of the new technique which have been developed, 87Sr NMR was employed to study the metal ion binding properties of alpha-Lactalbumin. The NMR data was fitted into a model with one high affinity and one low affinity site in alpha-Lactalbumin. The calculation of the correlation time, quadrupolar coupling constant provided the opportunity to study the location and the structure of the binding sites. In the application of the new technique in the area of biology, 25Mg NMR was employed to study the metal ion binding properties of bacteriorhodopsin. We presented the results of our studies regarding to two important questions in the photo conversion process: (1) The number of metal binding sites and their binding constants; and (2) What is the role of metal cations in the proton dissociation process/proton transfer (e.g., the key issue of the switch of the proton pump)? 113Cd NM of metal-bR complexes was employed as a probe of the chemical structure of bR calcium binding sites. We discuss the results in terms of the possible involvement of the metal cations in the bR function.

  14. Conservation of both current and helicity in a quadrupolar model for solar flares

    E-print Network

    Don Melrose

    2004-03-02

    A model for a solar flare, involving magnetic reconnection transferring flux and current between current-carrying magnetic loops connecting two pairs of footpoints, is generalized to include conservation of magnetic helicity during reconnection, as well as conservation of current at all four footpoints. For a set of force-free loops, with the $i$th loop having flux $F_i$ and current $I_i$, the self and mutual helicities are proportional to the self and mutual inductances with the constant of proportionality determined by $\\alpha_i=F_i/\\mu_0I_i$. In a constant-$\\alpha$ model, the change in magnetic energy is proportional to the change in helicity, and conservation of helicity implies conservation of magnetic energy, so that a flare cannot occur. In a quadrupolar model, with $\\alpha_1>\\alpha_2$ initially, $\\alpha_1$ increases and $\\alpha_2$ decreases when flux and current are transferred from loops~1 and~2 to loops~3 and~4. A model that conserves both current and helicity is constructed; it depends on the initial $\\alpha$s, and otherwise is somewhat simpler than when helicity is neglected.

  15. Order, Order!

    NSDL National Science Digital Library

    This activity helps students develop a sense of the relative size of quantities in time, length and mass. Learners rank their estimates of given measures in order from least to greatest and justify their decisions. The Teachers' Notes page includes suggestions for implementation, discussion questions, ideas for extension and support, printable cards (pdf), and a link to a related problem, "In Order" (cataloged separately). The solutions page shows that students used standard units of measure to make their comparisons.

  16. Two-Photon Absorption Properties of Proquinoidal D-A-D and A-D-A Quadrupolar Chromophores

    PubMed Central

    Susumu, Kimihiro; Fisher, Jonathan A. N.; Zheng, Jieru

    2011-01-01

    We report the synthesis, one- and two-photon absorption spectroscopy, fluorescence, and electrochemical properties of a series of quadrupolar molecules that feature proquinoidal ?-aromatic acceptors. These quadrupolar molecules possess either donor-acceptor-donor (D–A–D) or acceptor-donor-acceptor (A–D–A) electronic motifs, and feature 4-N,N-dihexylaminophenyl, 4-dodecyloxyphenyl, 4-(N,N-dihexylamino)benzo[c][1,2,5]thiadiazolyl or 2,5-dioctyloxyphenyl electron donor moieties and benzo[c][1,2,5]thiadiazole (BTD) or 6,7-bis(3’,7’-dimethyloctyl)[1,2,5]thiadiazolo[3,4-g]quinoxaline (TDQ) electron acceptor units. These conjugated structures are highly emissive in nonpolar solvents and exhibit large spectral red-shifts of their respective lowest energy absorption bands relative to analogous reference compounds that incorporate phenylene components in place of BTD and TDQ moieties. BTD-based D-A-D and A-D-A chromophores exhibit increasing fluorescence emission red-shifts, and a concomitant decrease of the fluorescence quantum yield (?f) with increasing solvent polarity; these data indicate that electronic excitation augments benzothiadiazole electron density via an internal charge transfer mechanism. The BTD- and TDQ-containing structures exhibit blue-shifted two-photon absorption (TPA) spectra relative to their corresponding one-photon absorption (OPA) spectra, and display high TPA cross-sections (>100 GM) within these spectral windows. D-A-D and A-D-A structures that feature more extensive conjugation within this series of compounds exhibit larger TPA cross-sections consistent with computational simulation. Factors governing TPA properties of these quadrupolar chromophores are discussed within the context of a three-state model. PMID:21568299

  17. Theory of Relaxation of Quadrupolar Nuclei in Deformable Molecules in Isotropic Solutions. Application to DNA

    NASA Astrophysics Data System (ADS)

    Schurr, J. M.; Fujimoto, B. S.; Nuutero, S.

    Expressions are derived for the longitudinal ( RQ1) and transverse ( RQ2) relaxation rates of quadrupolar nuclei in deformable molecules in isotropic solution. These rates are expressed in terms of principal spectral densities, which are all Fourier transforms of the same principal correlation function. These results are specialized to molecules that exhibit mean local cylindrical symmetry and explicitly evaluated for the case when the equilibrium orientation of the principal axis of the electric field gradient (efg) tensor is perpendicular to the local symmetry axis. Proper account is taken of collective twisting and bending deformations, uniform (rigid-body) twisting and tumbling motions, and local angular motions of the efg tensor within its subunit. Analytical expressions for the internal correlation functions, which reflect the local angular motions, are derived for a model in which the efg tensor frame undergoes small amplitudes of overdamped libration in a harmonic potential that governs each of its three rotational degrees of freedom. Sample calculations of ( RQ1) are presented for a range of possible rms angular displacements and relaxation times of the internal motions for the particular case of deuterons at the H8 positions of adenine and guanine in a 12 bp duplex DNA. Somewhat simpler analytical expressions for the long-time limits of the internal correlation functions are derived for the case when the efg tensor frame undergoes an arbitrary amplitude of overdamped libration in an isotropic harmonic deflection potential. A particularly simple expression is obtained when the efg tensor undergoes small amplitudes of motion in a completely isotropic deflection potential with arbitrary orientation. These simpler expressions can be used to calculate RQ1 and RQ2, when the local angular motions relax in a time much less than the inverse Larmor frequency (? -1), and their contribution to the integrated area under the principal correlation function is negligible compared to the Fourier cosine transform of the principal correlation function. Corresponding results for relaxation by pure chemical-shift anisotropy and by pure-dipolar interactions are presented in the present notation.

  18. Symmetry-Amplified J Splittings for Quadrupolar Spin Pairs: A Solid-State NMR Probe of Homoatomic Covalent Bonds

    PubMed Central

    2013-01-01

    Chemically informative J couplings between pairs of quadrupolar nuclei in dimetallic and dimetalloid coordination motifs are measured using J-resolved solid-state NMR experiments. It is shown that the application of a double-quantum filter is necessary to observe the J splittings and that, under these conditions, only a simple doublet is expected. Interestingly, the splitting is amplified if the spins are magnetically equivalent, making it possible to measure highly precise J couplings and unambiguously probe the symmetry of the molecule. This is demonstrated experimentally by chemically breaking the symmetry about a pair of boron spins by reaction with an N-heterocyclic carbene to form a ?-borylation reagent. The results show that the J coupling is a sensitive probe of bonding in diboron compounds and that the J values quantify the weakening of the B–B bond which occurs when forming an sp2–sp3 diboron compound, which is relevant to their reactivity. Due to the prevalence of quadrupolar nuclei among transition metals, this work also provides a new approach to probe metal–metal bonding; results for Mn2(CO)10 are provided as an example. PMID:23919916

  19. From bipolar to quadrupolar electrode structures: an application of bond-detach lithography for dielectrophoretic particle assembly.

    PubMed

    Menad, Samia; El-Gaddar, Amal; Haddour, Naoufel; Toru, Sylvain; Brun, Mathieu; Buret, François; Frenea-Robin, Marie

    2014-05-20

    We describe a new, simple process for fabricating transparent quadrupolar electrode arrays enabling large-scale particle assembly by means of dielectrophoresis. In the first step, interdigitated electrode arrays are made by chemical wet etching of indium tin oxide (ITO). Then, the transition from a bipolar to a quadrupolar electrode arrangement is obtained by covering the electrode surface with a thin poly(dimethylsiloxane) (PDMS) film acting as an electrical insulation layer in which selective openings are formed using bond-detach lithography. The PDMS insulating layer thickness was optimized and controlled by adjusting experimental parameters such as the PDMS viscosity (modulated by the addition of heptane) and the PDMS spin-coating velocity. The insulating character of the PDMS membrane was successfully demonstrated by performing a dielectrophoretic assembly of polystyrene particles using interdigitated electrodes with and without a PDMS layer. The results show that the patterned PDMS film functions properly as an electrical insulation layer and allows the reconfiguration of the electric field cartography. Electric field simulations were performed in both configurations to predict the dielectrophoretic behavior of the particles. The simulation results are in perfect agreement with experiments, in which we demonstrated the formation of concentrated clusters of polystyrene particles and living cells of regular size and shape. PMID:24758738

  20. Relevance of Triple Coupling of Multipolar Order Parameters in URu_2Si_2

    NASA Astrophysics Data System (ADS)

    Koga, M.; Cox, D. L.

    2000-03-01

    We investigate stability of the tiny staggered magnetic dipole moment observed in URu_2Si_2, provided that an antiferroquadrupolar ordering takes place as a primary effect. A ferromagnetic octupolar ordering plays an important role in stabilizing the moment, and the stability conditions are very sensitive to the crystalline-electronic-field (CEF) energy levels of U and the RKKY couplings between the U sites. Our mean-field solution shows that the tiny dipolar ordering is hardly realized for the three lowest-lying CEF singlets proposed by Santini and Amoretti. Alternatively, we stress relevance of the non-Kramers doublets to obtain the tiny moment at low temperatures. We suggest that by combining short range quadrupolar order with the two-channel Kondo effect we can explain the magnetic susceptibility above the quadrupolar ordering temperature.

  1. Off-resonance NMR on nitrogen-15 in guanosine and phase cycling of quadrupolar nmr on oxygen-17 in silica

    NASA Astrophysics Data System (ADS)

    Malave, Peter Lorenzo

    Nuclear magnetic resonance in the solid state provides a wealth of inter- and intramolecular interactions that can be utilized to provide useful physical information. Chemical shift, dipolar, J-coupling, and quadrupolar interactions are all present in the solid state and provide complementary information on molecular structure and dynamics. In this work, dipolar, J-coupling, and quadrupolar interactions are studied. Lee-Goldburg off-resonance excitation is employed on a sample of 15N enriched guanosine to determine inter and intramolecular nitrogen-hydrogen distances and the scalar J-coupling constant. Satellite transition magic angle spinning is employed on an 17O enriched sample in silica to experimentally study phase cycling effects. Lee-Goldburg decoupling on guanosine is employed to determine scalar coupling in 15N bonded to 1H in guanosine. Experimental results are compared to theoretically predicted results. Results show scaling factors of 0.47 +/- 0.03 and 0.39 +/- 0.13 compared to theoretical values of 0.58. Also, a hydrogen bond shift in the resonance frequencies is postulated. Lee-Goldburg cross polarization on guanosine is used to probe inter-nuclear distances of 15N bonded to 1H in guanosine. Results are compared to x-ray crystal structures where positions of protons are energetically optimized. Simulation of experimental results is also used to compare x-ray bond lengths to Lee-Goldburg cross polarization results. The Lee-Goldburg results for N-H and N-H2 bonds show stronger agreement with simulation than x-ray results. Differences in distances range from 0.01 to 0.05 A N-H hydrogen bond distances are also compared. Finally, phase cycling effects are studied in satellite transition magic angle spinning experiments on 17O in silica. Results show that a variety of phase cycles for the final pulse in the pulse sequence can be employed to give quantitatively the same result. On the other hand, phase cycles for the first and second pulses may significantly alter the spectrum, showing more coherences for smaller numbers of phase cycles.

  2. SMA CO(2-1) Observations of CG30: A Protostellar Binary System with a High-Velocity Quadrupolar Molecular Outflow

    E-print Network

    Xuepeng Chen; Tyler L. Bourke; Ralf Launhardt; Thomas Henning

    2008-09-15

    We present interferometric observations in the 12CO (2-1) line and at 1.3 mm dust continuum of the low-mass protostellar binary system in the cometary globule CG30, using the Submillimeter Array. The dust continuum images resolve two compact sources (CG30N and CG30S), with a linear separation of ~8700 AU and total gas masses of ~1.4 and ~0.6 M_sun, respectively. With the CO images, we discover two high-velocity bipolar molecular outflows, driven by the two sources. The two outflows are nearly perpendicular to each other, showing a quadrupolar morphology. The northern bipolar outflow extends along the southeast (redshifted, with a velocity up to ~23 km/s) and northwest (blueshifted, velocity up to ~30 km/s) directions, while the southern pair has an orientation from southwest (blueshifted, velocity up to 13 km/s) to northeast (redshifted, velocity up to ~41 km/s). The outflow mass of the northern pair, driven by the higher mass source CG30N, is ~9 times larger than that of the southern pair. The discovery of the quadrupolar molecular outflow in the CG30 protobinary system, as well as the presence of other quadrupolar outflows associated with binary systems, demonstrate that the disks in (wide) binary systems are not necessarily co-aligned after fragmentation.

  3. AN ENVELOPE DISRUPTED BY A QUADRUPOLAR OUTFLOW IN THE PRE-PLANETARY NEBULA IRAS 19475+3119

    SciTech Connect

    Hsu, Ming-Chien; Lee, Chin-Fei, E-mail: mchsu@asiaa.sinica.edu.tw, E-mail: cflee@asiaa.sinica.edu.tw [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China)

    2011-07-20

    IRAS 19475+3119 is a quadrupolar pre-planetary nebula (PPN), with two bipolar lobes, one in the east-west (E-W) direction and one in the southeast-northwest (SE-NW) direction. We have observed it in CO J = 2-1 with the Submillimeter Array at {approx}1'' resolution. The E-W bipolar lobe is known to trace a bipolar outflow and it is detected at high velocity. The SE-NW bipolar lobe appears at low velocity, and could trace a bipolar outflow moving in the plane of the sky. Two compact clumps are seen at low velocity around the common waist of the two bipolar lobes, spatially coincident with the two emission peaks in the NIR, tracing dense envelope material. They are found to trace the two limb-brightened edges of a slowly expanding torus-like circumstellar envelope produced in the late asymptotic giant branch phase. This torus-like envelope originally could be either a torus or a spherical shell, and it appears as it is now because of the two pairs of cavities along the two bipolar lobes. Thus, the envelope appears to be disrupted by the two bipolar outflows in the PPN phase.

  4. Effect of strongly coupled plasma on the magnetic dipolar and quadrupolar transitions of two-electron ions

    SciTech Connect

    Saha, Jayanta K.; Mukherjee, T. K. [Department of Physics, Narula Institute of Technology, Agarpara, Kolkata 700 109, West Bengal (India); Mukherjee, P. K. [Department of Physics, Ramakrishna Mission Vivekananda University, Belur Math, Howrah 711202, West Bengal (India); Department of Mathematics, Visva Bharati, Santiniketan 731235, West Bengal (India); Fricke, B. [Institute fur Physik, Universitat Kassel, 34109 Kassel (Germany)

    2013-04-15

    Effect of strongly coupled plasma on the excitation energies and transition probabilities for the respective transitions 1s{sup 2}:{sup 1}S{sup e}{yields} 1sns:{sup 3}S{sup e} (n = 2, 3, 4) and 1s{sup 2}:{sup 1}S{sup e}{yields} 1snp:{sup 3}P{sup o} (n = 2, 3, 4) allowed by magnetic dipolar and quadrupolar excitations have been analyzed for the first time for the two-electron ions C{sup 4+}, O{sup 6+}, Ne{sup 8+}, Mg{sup 10+}, Si{sup 12+}, and S{sup 14+}. Time dependent Hatree-Fock theory within variational approach has been adopted for such a study. The effect of surrounding plasma has been treated through the standard Ion-Sphere (IS) model of the plasma where the plasma density is varied systematically from a low value to a pretty high value such that the respective excited states go over to continuum due to such a confinement. The effect of external pressure generated due to plasma confinement on the estimated spectral properties has been analyzed systematically.

  5. Magnetic dipolar and quadrupolar transitions in two-electron atoms under exponential-cosine-screened Coulomb potential

    NASA Astrophysics Data System (ADS)

    Modesto-Costa, Lucas; Canuto, Sylvio; Mukherjee, Prasanta K.

    2015-03-01

    A detailed investigation of the magnetic dipolar and quadrupolar excitation energies and transition probabilities of helium isoelectronic He, Be2+, C4+, and O6+ have been performed under exponential cosine screened Coulomb potential generated in a plasma environment. The low-lying excited states 1s2:1Se ? 1sns:3Se0, and 1snp:3Po2 (n = 2, 3, 4, and 5) are considered. The variational time-dependent coupled Hartree-Fock scheme has been used. The effect of the confinement produced by the potential on the structural properties is investigated for increasing coupling strength of the plasma. It is noted that there is a gradual destabilization of the energy of the system with the reduction of the ionization potential and the number of excited states. The effect of the screening enhancement on the excitation energies and transition probabilities has also been investigated and the results compared with those available for the free systems and under the simple screened Coulomb potential.

  6. Spin-orbit coupling in d2 ordered double perovskites

    NASA Astrophysics Data System (ADS)

    Chen, Gang; Balents, Leon

    2011-09-01

    We construct and analyze a microscopic model for insulating rock-salt ordered double perovskites, with the chemical formula A2BB'O6, where the magnetic ion B' has a 4d2 or 5d2 electronic configuration and forms a face-centered cubic lattice. For these B' ions, the combination of the triply degenerate antisymmetric two-electron orbital states and strong spin-orbit coupling forms local quintuplets with an effective spin moment j=2. Moreover, due to strongly orbital-dependent exchange, the effective spins have substantial biquadratic and bicubic interactions (fourth and sixth order in the spins, respectively). This leads, at the mean-field level, to a rich ground-state phase diagram, which includes seven different phases: a uniform ferromagnetic phase with an ordering wave vector p=0 and uniform magnetization along the [111] direction, four two-sublattice phases with an ordering wave vector p=2?(001), and two four-sublattice antiferromagnetic phases. Among the two-sublattice phases, there is a quadrupolar ordered phase that preserves time-reversal symmetry. By extending the mean-field theory to finite temperatures, we find 10 different magnetization processes with different magnetic thermal transitions. In particular, we find that thermal fluctuations stabilize the two-sublattice quadrupolar ordered phase in a large portion of the phase diagram. Existing and possible future experiments are discussed in light of these theoretical predictions.

  7. Molecular modelling and simulation of the surface tension of real quadrupolar fluids

    E-print Network

    Stephan Werth; Katrin Stöbener; Peter Klein; Karl-Heinz Küfer; Martin Horsch; Hans Hasse

    2014-08-21

    Molecular modelling and simulation of the surface tension of fluids with force fields is discussed. 29 real fluids are studied, including nitrogen, oxygen, carbon dioxide, carbon monoxide, fluorine, chlorine, bromine, iodine, ethane, ethylene, acetylene, propyne, propylene, propadiene, carbon disulfide, sulfur hexafluoride, and many refrigerants. The fluids are represented by two-centre Lennard-Jones plus point quadrupole models from the literature. These models were adjusted only to experimental data of the vapour pressure and saturated liquid density so that the results for the surface tension are predictions. The deviations between the predictions and experimental data for the surface tension are of the order of 20 percent. The surface tension is usually overestimated by the models. For further improvements, data on the surface tension can be included in the model development. A suitable strategy for this is multi-criteria optimization based on Pareto sets. This is demonstrated using the model for carbon dioxide as an example.

  8. Quantum Stark broadening of Ar XV lines. Strong collision and quadrupolar potential contributions

    NASA Astrophysics Data System (ADS)

    Elabidi, H.; Sahal-Bréchot, S.; Dimitrijevi?, M. S.

    2014-10-01

    We present in this paper electron impact broadening for six Ar XV lines using our quantum mechanical formalism and the semiclassical perturbation one. Additionally, our calculations of the corresponding atomic structure data (energy levels and oscillator strengths) and collision strengths are given as well. The lines considered here are divided into two sets: a first set of four lines involving the ground level: 1s22s21S0- 1s22snp 1P1o where 2?n?5 and a second set of two lines involving excited levels: 1s22s2p 1P1o-1s22s3s 1S0 and 1s22s2p 3P0o-1s22s3s 3S1. An extensive comparison between the quantum and the semiclassical results was performed in order to analyze the reason for differences between quantum and semiclassical results up to the factor of two. It has been shown that the difference between the two results may be due to the evaluation of strong collision contributions by the semiclassical formalism. Except few semiclassical results, the present results are the first to be published. After the recent discovery of the far UV lines of Ar VII in the spectra of very hot central stars of planetary nebulae and white dwarfs, the present -and may be further- results can be used also for the corresponding future spectral analysis.

  9. Quadrupolar Outflow: A Single-Wind Model for the ? Carinae Nebula

    NASA Astrophysics Data System (ADS)

    Matt, S.; Balick, B.

    2002-12-01

    During an outburst beginning in 1837, the luminous blue variable ? Carinae ejected at least one solar mass of material. That ejected material has been well studied and is highly structured, consisting of an outflowing equatorial ``skirt'' and bipolar lobes (the hourglass-shaped ``homunculus''). Recent proper motion measurements of Morse et al. (2001, ApJ, 548, 207L) suggest that at least some of the material in the skirt has the same dynamical age as the lobes, contrary to the assumptions of interacting winds models for the ? Car nebula. In the context of the ? Car eruption, and relying on time-dependent, numerical, magnetohydrodynamic simulations, we present a simple stellar wind model that produces an outflowing disk and bipolar lobes in a single wind. The shape of the wind bears a remarkable resemblance to the overall shape of the ? Car nebulae. The basic model consists of a pressure-driven wind from a rotating star with an axis-aligned dipole magnetic field. In the wind, the azimuthal component of the magnetic field (generated by the rotation of the dipolar field) compresses the wind toward the equator and also toward the rotation axis, simultaneously producing an outflowing disk and jet. In order to produce wide angle lobes similar to the homunculus (which have roughly a 30o opening angle), a high-speed polar wind from the star is required. We will present both steady-state and time-dependent wind models. This research was supported by NASA grant GO 9050 awarded from STScI, by NSF grant AST-9729096, and by NSERC, McMaster University, and CITA through a CITA National Fellowship.

  10. Unusual anisotropic magnetoresistance in charge-orbital ordered Nd0.5Sr0.5MnO3 polycrystals

    NASA Astrophysics Data System (ADS)

    Yang, Huali; Wang, Baomin; Liu, Yiwei; Yang, Zhihuan; Zhu, Xiaojian; Xie, Yali; Zuo, Zhenghu; Chen, Bin; Zhan, Qingfeng; Wang, Junling; Li, Run-Wei

    2014-12-01

    Due to its potential application in magnetic recording and sensing technologies, the anisotropic magnetoresistance (AMR) effect has attracted lasting attention. Despite the long history, AMR effect has not been fully understood especially in the unconventional materials, such as perovskite manganites. Here, we report an unusual AMR effect in the charge-orbital ordered (COO) Nd0.5Sr0.5MnO3 polycrystals, which is observed when the magnetic field rotates in the plane that is perpendicular to the current (out-of-plane AMR). Despite being a polycrystalline sample where no anisotropy is expected, the resistivity shows a large irreversible drop with rotating magnetic field. A model has been proposed based on anisotropic magnetic field induced the melting of COO phase to explain the unusual out-of-plane AMR successfully. Our results demonstrate a new way for understanding the close relationship between phase separation and AMR effect in COO manganites.

  11. The magnetic field induced metal-insulator transition in n-type InP

    Microsoft Academic Search

    A. P. Long; M. Pepper

    1984-01-01

    The metal-insulator transition in n-type InP doped in excess of the Mott criterion has been induced by the application of a magnetic field. In the metallic regime the authors have investigated the corrections due to quantum interference and the electron-electron interaction. The interaction effect increases with decreasing temperature with a consequent reduction in the negative magnetoresistance. In the absence of

  12. Phonon spectrum of the QCD vacuum in a magnetic-field-induced superconducting phase

    NASA Astrophysics Data System (ADS)

    Chernodub, M. N.; Van Doorsselaere, Jos; Verschelde, Henri

    2014-05-01

    In the background of a sufficiently strong magnetic field the vacuum was suggested to become an ideal electric conductor (highly anisotropic superconductor) due to an interplay between the strong and electromagnetic forces. The superconducting ground state resembles an Abrikosov lattice state in an ordinary type-II superconductor: it is an inhomogeneous structure made of a (charged vector) quark-antiquark condensate pierced by vortices. In this paper the acoustic (phonon) vibrational modes of the vortex lattice are studied at zero temperature. Using an effective model based on a vector meson dominance, we show that in the infrared limit the longitudinal (transverse) acoustic vibrations of the vortex lattice possess a linear (quadratic) dispersion relation corresponding to type-I (type-II) Nambu-Goldstone modes.

  13. Magnetic Field Induced Biochemical and Growth Changes in Date Palm Seedlings

    Microsoft Academic Search

    F. Dhawi; J. M. Al-Khayri

    \\u000a The long life cycle of date palm (Phoenix dactylifera L.) makes genetic improvement through traditional breeding methods a tedious endeavor. Biotech­nology offers advanced tools\\u000a to augment genetic improvement efforts. In vitro selection technique, a major application of plant biotechnology, allows the isolation of mutant cells and the regeneration\\u000a of plants exhibiting desired new traits. Mutations can be induced chemically and

  14. An Experimental Determination of Static Magnetic Fields Induced Noise in Living Systems

    NASA Astrophysics Data System (ADS)

    Brady, Megan; Laramee, Craig

    2013-03-01

    Living systems are constantly exposed to static magnetic fields (SMFs) from both natural and man-made sources. Exposures vary in dose and duration ranging from geomagnetic (˜50?T) to residential and industrial (˜10s of mT) fields. Efforts to characterize responses to SMFs have yielded conflicting results, showing a dependence on experimental variables used. Here we argue that low to moderate SMF exposure is a sub-threshold perturbation operating below thermal noise, and assays that evaluate statistical characteristics of a single cell may identify responses not consistently found by population averaging approaches. Recent studies of gene expression show that it is a stochastic process capable of producing bursting dynamics. Moreover, theoretical and experimental methods have also been developed to allow quantitative estimates of the associated biophysical parameters. These developments provide a new way to assess responses of living systems to SMFs. In this work, we report on our efforts to use single molecule fluorescence in situ hybridization to assess responses of NIH-3T3 cells to SMF exposure at flux densities ranging from 1 to 440 mT for 48 hours. Results will contribute to determining mechanisms by which SMF exposure influences gene expression.

  15. Glass-ceramic-mediated, magnetic-field-induced localized hyperthermia: response of a murine mammary carcinoma

    SciTech Connect

    Luderer, A.A. (Corning Glass Works, Corning, NY); Borrelli, N.F.; Panzarino, J.N.; Mansfield, G.R.; Hess, D.M.; Brown, J.L.; Barnett, E.H.; Hahn, E.W.

    1983-04-01

    Hyperthermia has found to be a useful modality for cancer therapy. In this report, a biocompatible, ferrimagnetic glass-ceramic capable of inducing localized hyperthermia by hysteresis heating upon exposure to an alternating magnetic field is presented. When the glass-ceramic was placed in the region of a subcutaneously transplanted, weakly antigenic breast carcinoma and subjected to the magnetic field, sufficient temperature rise was obtained to cause significant (approx.50%) tumor regrowth delay and a 12% permanent control. The data demonstrate that glass-ceramic-mediated hysteresis heating may be a useful therapeutic approach in the treatment of cancer which offers the advantage of producing a highly localized and predictable tumor volume hyperthermia.

  16. Glass-ceramic-mediated, magnetic-field-induced localized hyperthermia: response of a murine mammary carcinoma

    Microsoft Academic Search

    A. A. Luderer; N. F. Borrelli; J. N. Panzarino; G. R. Mansfield; D. M. Hess; J. L. Brown; E. H. Barnett; E. W. Hahn

    1983-01-01

    Hyperthermia has found to be a useful modality for cancer therapy. In this report, a biocompatible, ferrimagnetic glass-ceramic capable of inducing localized hyperthermia by hysteresis heating upon exposure to an alternating magnetic field is presented. When the glass-ceramic was placed in the region of a subcutaneously transplanted, weakly antigenic breast carcinoma and subjected to the magnetic field, sufficient temperature rise

  17. Magnetic field induced discontinuous spin reorientation in ErFeO{sub 3} single crystal

    SciTech Connect

    Shen, Hui [School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai 201418 (China) [School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai 201418 (China); Institute for Superconducting and Electronic Materials, University of Wollongong, NSW 2500 (Australia); Cheng, Zhenxiang, E-mail: cheng@uow.edu.au; Hong, Fang; Wang, Xiaolin [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW 2500 (Australia)] [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW 2500 (Australia); Xu, Jiayue [School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai 201418 (China)] [School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai 201418 (China); Yuan, Shujuan; Cao, Shixun [Department of Physics, Shanghai University, Shanghai 200444 (China)] [Department of Physics, Shanghai University, Shanghai 200444 (China)

    2013-11-04

    The spin reorientation of ErFeO{sub 3} that spontaneously occurs at low temperature has been previously determined to be a process involving the continuous rotation of Fe{sup 3+} spins. In this work, the dynamic process of spin reorientation in ErFeO{sub 3} single crystal has been investigated by AC susceptibility measurements at various frequencies and static magnetic fields. Interestingly, two completely discontinuous steps are induced by a relatively large static magnetic field due to the variation in the magnetic anisotropy during this process. It provides deeper insights into the intriguing magnetic exchange interactions which dominate the sophisticated magnetic phase transitions in the orthoferrite systems.

  18. Phonon spectrum of QCD vacuum in magnetic-field-induced superconducting phase

    E-print Network

    M. N. Chernodub; Jos Van Doorsselaere; Henri Verschelde

    2014-06-16

    In the background of a sufficiently strong magnetic field the vacuum was suggested to become an ideal electric conductor (highly anisotropic superconductor) due to an interplay between the strong and electromagnetic forces. The superconducting ground state resembles an Abrikosov lattice state in an ordinary type--II superconductor: it is an inhomogeneous structure made of a (charged vector) quark-antiquark condensate pierced by vortices. In this paper the acoustic (phonon) vibrational modes of the vortex lattice are studied at zero temperature. Using an effective model based on a vector meson dominance, we show that in the infrared limit the longitudinal (transverse) acoustic vibrations of the vortex lattice possess a linear (quadratic) dispersion relation corresponding to type I (type II) Nambu--Goldstone modes.

  19. Magnetic-field-induced microstructural features in a high carbon steel during diffusional phase transformation

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoxue; Zhang, Yudong; Gong, Minglong; Esling, Claude; Zhao, Xiang; Zuo, Liang

    2012-12-01

    In this work, a high purity, high carbon steel was heat treated without and with a 12-T magnetic field. The microstructural features induced by magnetic field during its diffusion-controlled austenite decomposition were investigated by means of optical microscopy and SEM/EBSD. It is found that the magnetic field increases the amount of the abnormal structure, which is composed of proeutectoid cementite along the prior austenite boundaries and ferrite around it, because magnetic field increases the austenite grain size and promotes the transformation of carbon-depleted austenite to ferrite. No specific orientation relationship between abnormal ferrite and cementite has been found in the non-field- or the field-treated specimens. Magnetic field evidently promotes the spheroidization of pearlite, due to its effect of enhancing carbon diffusion through raising the transformation temperature and its effect of increasing the relative ferrite/cementite interface energy. As magnetic field favors the nucleation of the high magnetization phase-pearlitic ferrite, the occurrence of the P-P2 OR that corresponds to the situation that ferrite nucleates prior to cementite during pearlitic transformation is enhanced by the magnetic field.

  20. Particle size and magnetic field-induced optical properties of magnetic fluid nanoparticles.

    PubMed

    Rao, G Narsinga; Yao, Y D; Chen, Y L; Wu, K T; Chen, J W

    2005-09-01

    Magnetite nanoparticles with diameters of 7, 9, and 12 nm have been prepared by a chemical coprecipitation method. The transmission of light through magnetic fluid containing these nanoparticles has been investigated as a function of film thickness with wavelength between 400 and 750 nm, and applied magnetic fields up to 275 Oe. The transmission threshold shifts to the lower wavelength side with decreasing magnetic fluid film thickness as well as the particle size. For a given film thickness, the transmittance increases with increasing magnetic field for films with a particle size of 7 and 9 nm, but decreases in the 12-nm film. This is attributed to the competition between the van der Waals and dipole-dipole interaction. PMID:16241436

  1. Theory of the magnetic-field-induced insulator in neutral graphene sheets

    NASA Astrophysics Data System (ADS)

    Jung, J.; MacDonald, A. H.

    2009-12-01

    Recent experiments have demonstrated that neutral graphene sheets have an insulating ground state in the presence of an external magnetic field. We report on a ? -band tight-binding-model Hartree-Fock calculation which examines the competition between distinct candidate insulating ground states. We conclude that for graphene sheets on substrates the ground state is most likely a field-induced spin-density wave and that a charge-density-wave state is possible for suspended samples. Neither of these density-wave states support gapless edge excitations.

  2. Extremely Low Frequency Magnetic Fields Induce Spermatogenic Germ Cell Apoptosis: Possible Mechanism

    PubMed Central

    Lee, Sang-Kon; Park, Sungman; Gimm, Yoon-Myoung; Kim, Yoon-Won

    2014-01-01

    The energy generated by an extremely low frequency electromagnetic field (ELF-EMF) is too weak to directly induce genotoxicity. However, it is reported that an extremely low frequency magnetic field (ELF-MF) is related to DNA strand breakage and apoptosis. The testes that conduct spermatogenesis through a dynamic cellular process involving meiosis and mitosis seem vulnerable to external stress such as heat, MF exposure, and chemical or physical agents. Nevertheless the results regarding adverse effects of ELF-EMF on human or animal reproductive functions are inconclusive. According to the guideline of the International Commission on Non-Ionizing Radiation Protection (ICNIRP; 2010) for limiting exposure to time-varying MF (1?Hz to 100?kHz), overall conclusion of epidemiologic studies has not consistently shown an association between human adverse reproductive outcomes and maternal or paternal exposure to low frequency fields. In animal studies there is no compelling evidence of causal relationship between prenatal development and ELF-MF exposure. However there is increasing evidence that EL-EMF exposure is involved with germ cell apoptosis in testes. Biophysical mechanism by which ELF-MF induces germ cell apoptosis has not been established. This review proposes the possible mechanism of germ cell apoptosis in testes induced by ELF-MF. PMID:25025060

  3. Magnetic-field-induced tunneling and minigap transport in double quantum wells

    SciTech Connect

    Lyo, S.K.; Simmons, J.A.; Harff, N.E.; Eiles, T.M.; Klem, J.F.

    1995-08-01

    We review recent theoretical and experimental results on low- temperature tunneling and in-plane transport properties in double quantum wells (DQWs) in an in-plane magnetic field B{parallel}. These properties arise from combined effect of B{parallel}-induced relative displacement of the wave vectors in the two QWs and the interwell tunneling. In weakly coupled DQWs, the tunneling conductance has two sharp maxima as a function of B{parallel}. In strongly coupled DQWs, a partial minigap is formed due to anticrossing of the two QW dispersion curves, yielding sharp B{parallel}-dependent structures in the density of states and in- plane transport properties. Excellent agreement is obtained between theory and data from GaAs/AlGaAs DQWs.

  4. External magnetic field-induced selective biodistribution of magnetoliposomes in mice

    PubMed Central

    2012-01-01

    This study looked at the effect of an external magnet on the biodistribution of magnetoliposomes intravenously administrated in mice (8?mg iron/kg) with and without induced acute inflammation. Our results showed that due to enhanced vascular permeability, magnetoliposomes accumulated at the site of inflammation in the absence of an external magnetic field, but the amount of iron present increased under the effect of a magnet located at the inflammation zone. This increase was dependent on the time (20 or 60?min) of exposure of the external magnetic field. It was also observed that the presence of the magnet was associated with lower amounts of iron in the liver, spleen, and plasma than was found in mice in which a magnet had not been applied. The results of this study confirm that it is possible to target drugs encapsulated in magnetic particles by means of an external magnet. PMID:22883385

  5. Magnetic-field-induced dielectric anomaly and electric polarization in Mn4Nb2O9

    NASA Astrophysics Data System (ADS)

    Fang, Y.; Zhou, W. P.; Yan, S. M.; Bai, R.; Qian, Z. H.; Xu, Q. Y.; Wang, D. H.; Du, Y. W.

    2015-05-01

    Magnetic, dielectric, and magnetoelectric properties have been investigated in the polycrystalline Mn4Nb2O9. Under zero magnetic fields, no dielectric anomaly and electric polarization are observed in this compound. When the sample is exposed in magnetic field, finite dielectric peaks and electric polarization are induced, which increase with increasing magnetic field, showing magneto-dielectric and magnetoelectric effects. The origin of magnetoelectric coupling of this compound has been discussed.

  6. Giant magnetic-field-induced strains in Heusler alloy NiMnGa with modified composition

    E-print Network

    Zheng, Yufeng

    with the twin boundary motion. The martensitic self-strain has been found to be 2%, implying a preferential.95%. Grown crystals were annealed at 850 °C for four days and then were quenched in ice water. It is believed in the range of 30­50 °C without ap- plied field. All strain-H loops were measured just after the sample

  7. External magnetic field-induced selective biodistribution of magnetoliposomes in mice

    NASA Astrophysics Data System (ADS)

    García-Jimeno, Sonia; Escribano, Elvira; Queralt, Josep; Estelrich, Joan

    2012-08-01

    This study looked at the effect of an external magnet on the biodistribution of magnetoliposomes intravenously administrated in mice (8 mg iron/kg) with and without induced acute inflammation. Our results showed that due to enhanced vascular permeability, magnetoliposomes accumulated at the site of inflammation in the absence of an external magnetic field, but the amount of iron present increased under the effect of a magnet located at the inflammation zone. This increase was dependent on the time (20 or 60 min) of exposure of the external magnetic field. It was also observed that the presence of the magnet was associated with lower amounts of iron in the liver, spleen, and plasma than was found in mice in which a magnet had not been applied. The results of this study confirm that it is possible to target drugs encapsulated in magnetic particles by means of an external magnet.

  8. Measurements of the magnetic field induced by a turbulent flow of liquid metal

    SciTech Connect

    Nornberg, M.D.; Spence, E.J.; Kendrick, R.D.; Jacobson, C.M.; Forest, C.B. [Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States)

    2006-05-15

    Initial results from the Madison Dynamo Experiment provide details of the inductive response of a turbulent flow of liquid sodium to an applied magnetic field. The magnetic field structure is reconstructed from both internal and external measurements. A mean toroidal magnetic field is induced by the flow when an axial field is applied, thereby demonstrating the omega effect. Poloidal magnetic flux is expelled from the fluid by the poloidal flow. Small-scale magnetic field structures are generated by turbulence in the flow. The resulting magnetic power spectrum exhibits a power-law scaling consistent with the equipartition of the magnetic field with a turbulent velocity field. The magnetic power spectrum has an apparent knee at the resistive dissipation scale. Large-scale eddies in the flow cause significant changes to the instantaneous flow profile resulting in intermittent bursts of nonaxisymmetric magnetic fields, demonstrating that the transition to a dynamo is not smooth for a turbulent flow.

  9. Magnetic-field-induced crystallographic texture enhancement in cold-deformed FePt nanostructured magnets

    E-print Network

    Garmestani, Hamid

    with crystal- lographic texture of the hard phase: severe plastic deforma- tion SPD, cyclic cold rolling in certain crystal orientations so that the magnetic properties are improved. II. EXPERIMENTAL PROCEDURE increases 001 out-of-plane texture of the FePt hard phase by 50% and introduces magnetic anisotropy

  10. Magnetic-field-induced twin boundary motion in magnetic shape-memory alloys

    Microsoft Academic Search

    Harsh Deep Chopra; Chunhai Ji; V. V. Kokorin

    2000-01-01

    This paper reports direct microscopic evidence of magnetoelastic coupling between ferroelastic twin domains and ferromagnetic Weiss domains in magnetic shape memory alloys, using the Ni-Mn-Ga Heusler alloys. In a martensitically transformed Ni2+xMn1-xGa single crystal, the magnetic domains were found to be superimposed upon the martensite twin domains. Simultaneous observation of magnetic domains and twin domains as a function of applied

  11. Two-channel R-matrix analysis of magnetic-field-induced Feshbach resonances

    SciTech Connect

    Nygaard, Nicolai; Schneider, Barry I.; Julienne, Paul S. [Danish National Research Foundation Center for Quantum Optics, Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Physics Division, National Science Foundation, Arlington, Virginia 22230 (United States) and Electron and Optical Physics Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Atomic Physics Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

    2006-04-15

    A Feshbach resonance arises in cold atom scattering due to the complex interplay between several coupled channels. However, the essential physics of the resonance may be encapsulated in a simplified model consisting of just two coupled channels. In this paper we describe in detail how such an effective Feshbach model can be constructed from knowledge of a few key parameters, characterizing the atomic Born-Oppenheimer potentials and the low energy scattering near the resonance. These parameters may be obtained either from experiment or full coupled-channel calculations. Using R-matrix theory we analyze the bound state spectrum and the scattering properties of the two-channel model, and find it to be in good agreement with exact calculations.

  12. Terahertz probes of magnetic field induced spin reorientation in YFeO3 single crystal

    NASA Astrophysics Data System (ADS)

    Lin, Xian; Jiang, Junjie; Jin, Zuanming; Wang, Dongyang; Tian, Zhen; Han, Jiaguang; Cheng, Zhenxiang; Ma, Guohong

    2015-03-01

    Using the terahertz time-domain spectroscopy, we demonstrate the spin reorientation of a canted antiferromagnetic YFeO3 single crystal, by evaluating the temperature and magnetic field dependence of resonant frequency and amplitude for the quasi-ferromagnetic (FM) and quasi-antiferromagnetic modes (AFM), a deeper insight into the dynamics of spin reorientation in rare-earth orthoferrites is established. Due to the absence of 4f-electrons in Y ion, the spin reorientation of Fe sublattices can only be induced by the applied magnetic field, rather than temperature. In agreement with the theoretical predication, the frequency of FM mode decreases with magnetic field. In addition, an obvious step of spin reorientation phase transition occurs with a relatively large applied magnetic field of 4 T. By comparison with the family members of RFeO3 (R = Y3+ or rare-earth ions), our results suggest that the chosen of R would tailor the dynamical rotation properties of Fe ions, leading to the designable spin switching in the orthoferrite antiferromagnetic systems.

  13. Pressure-magnetic field induced phase transformation in Ni46Mn41In13 Heusler alloy

    NASA Astrophysics Data System (ADS)

    Rama Rao, N. V.; Manivel Raja, M.; Esakki Muthu, S.; Arumugam, S.; Pandian, S.

    2014-12-01

    The effect of hydrostatic pressure and magnetic field on the magnetic properties and phase transformation in Ni46Mn41In13 Heusler alloy was investigated. Pressure (P)-magnetic field (H)-temperature (T) phase diagram has been constructed from experimental results. In the P-T contour of the phase diagram, the slope of the austenite-martensite phase boundary line appears positive (dT/dP > 0), while it appears negative (dT/dH < 0) in the H-T contour. The results revealed that pressure and magnetic field have opposite effect on phase stabilization. The combined effect of pressure and magnetic field on martensitic transition has led to two important findings: (i) pressure dependent shift of austenite start temperature (As) is higher when larger field is applied, and (ii) field dependent shift of As is lowered when a higher pressure is applied. The pressure and magnetic field dependent shift observed in the martensitic transformation has been explained on the basis of thermodynamic calculations. Curie temperature of the phases was found to increase with pressure at a rate of 0.6 K/kbar.

  14. On magnetic-field-induced dissipationless electric current in helicoidal graphene nanoribbons

    E-print Network

    M. N. Chernodub

    2013-04-11

    We argue that twisted (helicoidal) graphene nanoribbons may support dissipationless electric current in the presence of static uniform magnetic field. The non-resistive charge transfer in this parity-odd system should be enhanced by thermal fluctuations.

  15. Magnetic fluid hyperthermia (MFH): Cancer treatment with AC magnetic field induced excitation of biocompatible superparamagnetic nanoparticles

    Microsoft Academic Search

    Andreas Jordan; Regina Scholz; Peter Wust; Horst Fähling; Roland Felix

    1999-01-01

    The story of hyperthermia with small particles in AC magnetic fields started in the late 1950s, but most of the studies were unfortunately conducted with inadequate animal systems, inexact thermometry and poor AC magnetic field parameters, so that any clinical implication was far behind the horizon.More than three decades later, it was found, that colloidal dispersions of superparamagnetic (subdomain) iron

  16. Fine structure in the quadrupolar transition of the Ho L{sub 3} pre-edge observed by lifetime-broadening-suppressed XANES spectroscopy

    SciTech Connect

    Hayashi, Hisashi; Kawata, Masaki; Sato, Atsushi; Udagawa, Yasuo; Inami, Toshiya; Ishii, Kenji; Ogasawara, Haruhiko; Nanao, Susumu [IMRAM, Tohoku University, Katahira 2-1-1, Sendai 980-8577, Japan and PRESTO, JST, 4-1-8 Honcho Kawaguchi, Saitama, 332-0012 (Japan); SRRC, JAERI, Mikazuki, Hyogo, 679-5148 (Japan); Department of Physics, Northern Illinois University, DeKalb, Illinois 60115 (United States) and APS, Argonne National Laboratory, 9700, South Cass Avenue, Illinois 60439 (United States); IIS, University of Tokyo, Komaba 4-6-1, Meguro, Tokyo 153-8505 (Japan)

    2005-07-15

    The 2p3d resonant inelastic x-ray-scattering spectra of Ho{sub 2}O{sub 3} are measured under 0.7 eV resolution and analyzed in terms of an equation based on the Kramers-Heisenberg formula. Broadening due to core-hole lifetime (4.26 eV) is completely suppressed to give sharp absorption bands with width of <0.5 eV together with energy position uncertainty {approx}0.3 eV. Observed bands are assigned to be well-known 2p{yields}4f quadrupolar transitions that are otherwise buried under lifetime-broadened intense 2p{yields}5d dipole transition. The present work opens up an opportunity to study 4f-5d interactions more accurately.

  17. Collective Mode in a Superconductor with Mixed-Symmetry Order Parameter Components

    SciTech Connect

    Balatsky, A. V. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kumar, P. [Department of Physics, University of Florida, P.O. Box 118440, Gainesville, Florida 32611 (United States)] [Department of Physics, University of Florida, P.O. Box 118440, Gainesville, Florida 32611 (United States); Schrieffer, J. R. [NHMFL, Florida State University, 1800 E. Paul Dirac Drive, Tallahassee, Florida 32310 (United States)] [NHMFL, Florida State University, 1800 E. Paul Dirac Drive, Tallahassee, Florida 32310 (United States)

    2000-05-08

    We consider a superconducting state with mixed-symmetry order parameter components, e.g., d+is or d+id{sup '} with d{sup '}=d{sub xy} . We argue for the existence of a new orbital magnetization mode which corresponds to oscillations of relative phase {phi} between two components around an equilibrium value of {phi}=({pi}/2) . It is similar to the ''clapping'' mode in superfluid {sup 3}He- A . We estimate the frequency of this mode {omega}{sub 0}(B, T) depending on the field and temperature for the specific case of magnetic field induced d{sup '}=d{sub xy} state. This mode is tunable with a magnetic field with {omega}{sub 0}(B, T)(propor to)B{delta}{sub 0} , where {delta}{sub 0} is the magnitude of the d -wave order parameter. We also estimate the velocity s(B, T) of this mode. (c) 2000 The American Physical Society.

  18. Heavy-fermion superconductivity in the quadrupole ordered state of PrV2Al20.

    PubMed

    Tsujimoto, Masaki; Matsumoto, Yosuke; Tomita, Takahiro; Sakai, Akito; Nakatsuji, Satoru

    2014-12-31

    PrV2Al20 is a rare example of a heavy-fermion system based on strong hybridization between conduction electrons and nonmagnetic quadrupolar moments of the cubic ?3 ground doublet. Here, we report that a high-quality single crystal of PrV2Al20 exhibits superconductivity at Tc=50??mK in the antiferroquadrupole-ordered state under ambient pressure. The heavy-fermion character of the superconductivity is evident from the specific heat jump of ?C/T?0.3??J/mol?K(2) and the effective mass m*/m0?140 estimated from the temperature dependence of the upper critical field. Furthermore, the high-quality single crystals exhibit double transitions at TQ=0.75??K and T*=0.65??K associated with quadrupole and octupole degrees of freedom of the ?3 doublet. In the ordered state, the specific heat C/T shows a T(3) dependence, indicating the gapless mode associated with the quadrupole order, the octupole order, or both. The strong sensitivity to impurity of the superconductivity suggests unconventional character due to significant quadrupolar fluctuations. PMID:25615375

  19. Heavy-Fermion Superconductivity in the Quadrupole Ordered State of PrV2Al20

    NASA Astrophysics Data System (ADS)

    Tsujimoto, Masaki; Matsumoto, Yosuke; Tomita, Takahiro; Sakai, Akito; Nakatsuji, Satoru

    2014-12-01

    PrV2Al20 is a rare example of a heavy-fermion system based on strong hybridization between conduction electrons and nonmagnetic quadrupolar moments of the cubic ?3 ground doublet. Here, we report that a high-quality single crystal of PrV2Al20 exhibits superconductivity at Tc=50 mK in the antiferroquadrupole-ordered state under ambient pressure. The heavy-fermion character of the superconductivity is evident from the specific heat jump of ? C /T ˜0.3 J /mol K2 and the effective mass m*/m0˜140 estimated from the temperature dependence of the upper critical field. Furthermore, the high-quality single crystals exhibit double transitions at TQ=0.75 K and T*=0.65 K associated with quadrupole and octupole degrees of freedom of the ?3 doublet. In the ordered state, the specific heat C /T shows a T3 dependence, indicating the gapless mode associated with the quadrupole order, the octupole order, or both. The strong sensitivity to impurity of the superconductivity suggests unconventional character due to significant quadrupolar fluctuations.

  20. Towards homonuclear J solid-state NMR correlation experiments for half-integer quadrupolar nuclei: experimental and simulated 11B MAS spin-echo dephasing and calculated 2J(BB) coupling constants for lithium diborate.

    PubMed

    Barrow, Nathan S; Yates, Jonathan R; Feller, Steven A; Holland, Diane; Ashbrook, Sharon E; Hodgkinson, Paul; Brown, Steven P

    2011-04-01

    Magic-angle spinning (MAS) NMR spin-echo dephasing is systematically investigated for the spin I = 3/2 (11)B nucleus in lithium diborate, Li(2)O·2B(2)O(3). A clear dependence on the quadrupolar frequency (?(Q)(PAS)/2? = 3C(Q)/[4I(2I- 1)]) is observed: the B3 (larger C(Q)) site dephases more slowly than the B4 site at all investigated MAS frequencies (5 to 20 kHz) at 14.1 T. Increasing the MAS frequency leads to markedly slower dephasing for the B3 site, while there is a much less evident effect for the B4 site. Considering samples at 5, 25, 80 (natural abundance) and 100% (11)B isotopic abundance, dephasing becomes faster for both sites as the (11)B isotopic abundance increases. The experimental behaviour is rationalised using density matrix simulations for two and three dipolar-coupled (11)B nuclei. The experimentally observed slower dephasing for the larger C(Q) (B3) site is reproduced in all simulations and is explained by the reintroduction of the dipolar coupling by the so-called "spontaneous quadrupolar-driven recoupling mechanism" having a different dependence on the MAS frequency for different quadrupolar frequencies. Specifically, isolated spin-pair simulations show that the spontaneous quadrupolar-driven recoupling mechanism is most efficient when the quadrupolar frequency is equal to twice the MAS frequency. While for isolated spin-pair simulations, increasing the MAS frequency leads to faster dephasing, agreement with experiment is observed for three-spin simulations which additionally include the homogeneous nature of the homonuclear dipolar coupling network. First-principles calculations, using the GIPAW approach, of the (2)J(11B-11B) couplings in lithium diborate, metaborate and triborate are presented: a clear trend is revealed whereby the (2)J(11B-11B) couplings increase with increasing B-O-B bond angle and B-B distance. However, the calculated (2)J(11B-11B) couplings are small (0.95, 1.20 and 2.65 Hz in lithium diborate), thus explaining why no zero crossing due to J modulation is observed experimentally, even for the sample at 25% (11)B where significant spin-echo intensity remains out to durations of ?200 ms. PMID:21321719

  1. Pseudogap, charge order, and pairing density wave at the hot spots in cuprate superconductors

    NASA Astrophysics Data System (ADS)

    Pépin, C.; de Carvalho, V. S.; Kloss, T.; Montiel, X.

    2014-11-01

    We address the timely issue of the presence of charge ordering at the hot spots in the pseudogap phase of cuprate superconductors in the context of an emergent SU(2) symmetry which relates the charge and pairing sectors. Performing the Hubbard-Stratonovich decoupling such that the free energy stays always real and physically meaningful, we exhibit three solutions of the spin-fermion model at hot spots. A careful examination of their stability and free energy shows that, at low temperatures, the system tends towards the coexistence of a charge density wave (CDW) and the composite order parameter made up of the diagonal quadrupolar density wave and pairing fluctuations of K. B. Efetov et al. [Nat. Phys. 9, 442 (2013), 10.1038/nphys2641]. The CDW is sensitive to the shape of the Fermi surface, in contrast to the diagonal quadrupolar order, which is immune to it. SU(2) symmetry within the pseudogap phase also applies to the CDW state, which therefore admits a pairing density p -wave counterpart breaking time-reversal symmetry.

  2. Ab initio calculations of external-field shifts of the 661-nm quadrupolar clock transition in neutral Ag atoms

    SciTech Connect

    Topcu, Suat; Nasser, Jamil; Daku, Latevi Max Lawson; Fritzsche, Stephan [Laboratoire LIS Versailles, 45 Avenue des Etats-Unis 78035 Versailles (France); Universite de Geneve, Sciences II, CH-1211 Geneva 4 (Switzerland); Institute fuer Physik, Universitaet Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel (Germany)

    2006-04-15

    Frequency shifts of the Ag I 4d{sup 10}5s {sup 2}S{sub 1/2}(F=0,M{sub F}=0) to 4d{sup 9}5s{sup 2} {sup 2}D{sub 5/2}(F{sup '}=2,M{sub F{sup '}}=0) electric-quadrupole transition at 330.6 nm due to external fields are calculated using multiconfigurational self-consistent field methods. As this forbidden transition is free from first order Doppler and Zeeman effects, it is under investigation for the realization of an atomic optical clock. The calculated perturbations are the light shift, the blackbody frequency shift, and the quadratic Zeeman shift. Results show that a total uncertainty of 10{sup -18} could be reach without confining the atoms in a Lamb-Dicke regime in an optical lattice.

  3. Soil Orders

    NSDL National Science Digital Library

    Developed by the US Department of Agriculture's Soil Survey Division (SSD), here is a high resolution poster with brief descriptions of the soil orders. Photos of soil profiles accompany descriptions of each order. The soil orders include: Alfisols, Andisols, Aridisols, Entisols, Gelisols, Histosols, Inceptisols, Mollisols, Oxisols, Spodusols, Ultisols, and Vertisols.

  4. Order Up

    ERIC Educational Resources Information Center

    Gibeault, Michael

    2005-01-01

    Change orders. The words can turn the stomachs of administrators. Horror stories about change orders create fear and distrust among school officials, designers and builders. Can change orders be avoided? If car manufacturers can produce millions of intricately designed vehicles, why can't the same quality control be achieved on a construction…

  5. Static Magnetic Field Induces Changes in Behavior and Electrical Activity of the Nervous System of the Crayfish

    NASA Astrophysics Data System (ADS)

    Alvarado-Alvarez, R.; Godina-Nava, J. J.; Serrano, G.; Suaste, E.; Rodríguez-Segura, M. A.; Toledo-Ramos, F.

    2002-08-01

    The influence of static magnetic fields over the behaviour of crayfish was studied. Under this condition, the response tendency of the crayfish was observed either toward north-west or north-east direction according the local magnetic north. This behaviour was concurrent with neural discharges recorded from the cerebral ganglia.

  6. INFLUENCE OF DIFFERENT INCUBATOR MODELS ON MAGNETIC FIELD-INDUCED CHANGES IN NEURITE OUTGROWTH IN PC-12 CELLS

    EPA Science Inventory

    OBJECTIVE: Devise a method to standardize responses of cells to MF-exposure in different incubator environments. METHODS: We compared the cell responses to generated MF in a standard cell-culture incubator (Forma, model #3158) with cell responses to the same exposure when a mu-m...

  7. INFLUENCE OF TEMPERATURE DURING THE ELECTRIC AND MAGNETIC FIELD-INDUCED ALTERATION OF CALCIUM RELEASE FROM BRAIN TISSUE, IN VITRO

    EPA Science Inventory

    The release of calcium ions from in vitro preparation of chicken brain-tissue has been used by several investigators to demonstrate the interaction of electric and magnetic (EM) fields with biological systems. or exposures with radiofrequency radiation amplitude modulated at extr...

  8. Magnetic Field-Induced T Cell Receptor Clustering by Nanoparticles Enhances T Cell Activation and Stimulates Antitumor Activity

    PubMed Central

    2015-01-01

    Iron–dextran nanoparticles functionalized with T cell activating proteins have been used to study T cell receptor (TCR) signaling. However, nanoparticle triggering of membrane receptors is poorly understood and may be sensitive to physiologically regulated changes in TCR clustering that occur after T cell activation. Nano-aAPC bound 2-fold more TCR on activated T cells, which have clustered TCR, than on naive T cells, resulting in a lower threshold for activation. To enhance T cell activation, a magnetic field was used to drive aggregation of paramagnetic nano-aAPC, resulting in a doubling of TCR cluster size and increased T cell expansion in vitro and after adoptive transfer in vivo. T cells activated by nano-aAPC in a magnetic field inhibited growth of B16 melanoma, showing that this novel approach, using magnetic field-enhanced nano-aAPC stimulation, can generate large numbers of activated antigen-specific T cells and has clinically relevant applications for adoptive immunotherapy. PMID:24564881

  9. Modulated spin structure responsible for the magnetic-field-induced polarization switching in multiferroic TbMn2O5

    NASA Astrophysics Data System (ADS)

    Lee, Jung-Hoon; Jang, Hyun Myung

    2015-01-01

    Orthorhombic TbMn2O5 (o -TMO ) is a well-known multiferroic manganite with the remarkable property of polarization switching at 3 K under a bias magnetic (H) field along the a axis of P b 21m . To theoretically account for this outstanding observation, we have proposed a modulated spin structure under the saturated bias H field by considering the relative strength of the three relevant exchange parameters in o -TMO . The proposed modulated structure based on density-functional theory (DFT) calculations is described in terms of the spin angle ? between the neighboring M n4 +-Mn3 + spin moments on the a-b plane. We have shown that the computed DFT polarization plotted as a function of ? satisfactorily accounts for the observed H -field-induced polarization switching. We have further theoretically shown that the square of the critical field strength (Hc) needed for the polarization switching is inversely proportional to the degree of the extrinsic magnetoelectric coupling. The computed partial charge density demonstrates that the H -field-induced polarization switching also accompanies with the switching in the sign of the excess valence-electron density.

  10. Hysteretic behavior of diamagnetic molecular assembly: Magnetic field-induced deformation of tubular self-assemblies composed of amphiphilic molecules

    Microsoft Academic Search

    Kentaro Suzuki; Takuya Tomita; Taro Toyota; Masakazu Iwasaka; Tadashi Sugawara

    2009-01-01

    Real-time observation of a morphologies of a multi-component tubular giant vesicle (tGV), which is a self-assembly composed of plural amphiphiles with different packing parameters, was carried out under application of a magnetic field. A tGV, one of the terminals of which was fixed to a bottom of a cell, exhibited the bending deformation under a magnetic field along the perpendicular

  11. Computation of the electric and magnetic fields induced in a plasma created by ionization lasting a finite interval of time

    SciTech Connect

    Banos, A. Jr.; Mori, W.B.; Dawson, J.M. (Univ. of California, Los Angeles (United States))

    1993-02-01

    It has been shown that when an infinite expanse of gas, carrying a linearly polarized electromagnetic wave, is instantly ionized, the initial wave is frequency upshifted. This phenomenon of frequency up-conversion through flash ionization gives rise to steady-state transmitted and reflected electromagnetic waves and, most notably, to a time-independent magnetic field. Here the authors study the case in which the final state of ionization is achieved not instantly but in a finite turn-on time, 0 [le] t [le] t[sub 0], which is followed by the steady-state t[sub 0] [le] t < [infinity]. The authors show that the electric field is obtained from the one-dimensional wave equation F[sup 11](t) + w[sub 0][sup 2]g(t)F(t) = 0 if electrons are born at rest when they are created during ionization. As a result, the instantaneous frequency of the upshifted radiation is w(t) = w[sub 0][radical]g(t). The electric field can be solved exactly for specific choices of g(t). The authors solve for the electric field using WKB approximations for arbitrary g(t). The authors then solve for the magnetic field by integrating Faraday's law. The authors find that the steady-state electric field amplitude depends on the steady-state value of g(t) but does not depend on the ionization time t[sub 0]. Conversely, the static magnetic field amplitude decreases with increasing turn-on time

  12. Magnetic Field-Induced Spectroscopy of Forbidden Optical Transitions with Application to Lattice-Based Optical Atomic Clocks

    Microsoft Academic Search

    A. V. Taichenachev; V. I. Yudin; C. W. Oates; C. W. Hoyt; Z. W. Barber; L. Hollberg

    2006-01-01

    We develop a method of spectroscopy that uses a weak static magnetic field to enable direct optical excitation of forbidden electric-dipole transitions that are otherwise prohibitively weak. The power of this scheme is demonstrated using the important application of optical atomic clocks based on neutral atoms confined to an optical lattice. The simple experimental implementation of this method---a single clock

  13. Resonant alteration of propagation in guiding structures with complex Robin parameter and its magnetic-field-induced restoration

    E-print Network

    Oleg Olendski

    2011-04-12

    Solutions of the scalar Helmholtz wave equation are derived for the analysis of the transport and thermodynamic properties of the two-dimensional disk and three-dimensional infinitely long straight wire in the external uniform longitudinal magnetic field $\\bf B$ under the assumption that the Robin boundary condition contains extrapolation length $\\Lambda$ with nonzero imaginary part $\\Lambda_i$. As a result of this complexity, the self-adjointness of the Hamiltonian is lost, its eigenvalues $E$ become complex too and the discrete bound states of the disk characteristic for the real $\\Lambda$ turn into the corresponding quasibound states with their lifetime defined by the eigenenergies imaginary parts $E_i$. Accordingly, the longitudinal flux undergoes an alteration as it flows along the wire with its attenuation/amplification being $E_i$-dependent too. It is shown that, for zero magnetic field, the component $E_i$ as a function of the Robin imaginary part exhibits a pronounced sharp extremum with its magnitude being the largest for the zero real part $\\Lambda_r$ of the extrapolation length. Increasing magnitude of $\\Lambda_r$ quenches the $E_i-\\Lambda_i$ resonance and at very large $\\Lambda_r$ the eigenenergies $E$ approach the asymptotic real values independent of $\\Lambda_i$. The extremum is also wiped out by the magnetic field when, for the large $B$, the energies tend to the Landau levels. Mathematical and physical interpretations of the obtained results are provided; in particular, it is shown that the finite lifetime of the disk quasibound states stems from the $\\Lambda_i$-induced currents flowing through the sample boundary. Possible experimental tests of the calculated effect are discussed; namely, it is argued that it can be observed in superconductors by applying to them the external electric field $\\cal E$ normal to the surface.

  14. In-plane gradient-magnetic-field-induced vortex lattices in spin-orbit-coupled Bose-Einstein condensations

    NASA Astrophysics Data System (ADS)

    Zhou, Xiang-Fa; Zhou, Zheng-Wei; Wu, Congjun; Guo, Guang-Can

    2015-03-01

    We consider the ground-state properties of the two-component spin-orbit-coupled ultracold bosons subject to a rotationally symmetric in-plane gradient magnetic field. In the noninteracting case, the ground state supports giant vortices carrying large angular momenta without rotating the trap. The vorticity is highly tunable by varying the amplitudes and orientations of the magnetic field. Interactions drive the system from a giant-vortex state to various configurations of vortex lattice states along a ring. Vortices exhibit ellipse-shaped envelopes with the major and minor axes determined by the spin-orbit coupling and healing lengths, respectively. Phase diagrams of vortex lattice configurations are constructed and their stabilities are analyzed.

  15. Magnetic field induced alignmentorientation conversion: Nonlinear energy shift and predissociation in Te2 B1u state

    E-print Network

    Auzinsh, Marcis

    effect of quadratic terms in Zeeman energy shift and magnetic predissociation PD , producing asymmetry crossing signals caused by B2 terms in Zeeman energy shift. © 1996 American Institute of Physics. S0021 Zeeman sublevels M,M with ener- gies EM ,EM , while MM M M 2 3 is the rate of relaxation of coherence

  16. Magnetic-Field-Induced V-Shaped Quantized Conductance Staircase in a Double-Layer Quantum Point Contact

    SciTech Connect

    Lyo, S.K.

    1999-01-04

    We show that the low-temperature conductance (G) of a quantum point contact consisting of ballistic tunnel-coupled double-layer quantum well wires is modulated by an in-layer magnetic field B{sub {parallel}} perpendicular to the wires due to the anticrossing. In a system with a small g factor, B{sub {parallel}} creates a V-shaped quantum staircase for G, causing it to decrease in steps of 2e{sup 2}/{Dirac_h} to a minimum and then increase to a maximum value, where G may saturate or decrease again at higher B{sub {parallel}}'s. The effect of B{sub {parallel}}-induced mass enhancement and spin splitting is studied. The relevance of the results to recent data is discussed.

  17. 50 Hz-Sinusoidal magnetic field induced effects on the bioelectric activity of single unit neurone cells

    NASA Astrophysics Data System (ADS)

    Azanza, María. J.; Calvo, Ana C.; del Moral, A.

    2001-05-01

    Neurones recruiting and synchronized bioelectric activity recorded from Helix aspersa brain ganglia, under exposure to 50 Hz sinusoidal magnetic fields of 1-15 mT intensity, is reported. We show recruiting responses from single neurones and the synchronization of pairs of neurones activity. Experimental evidence and model theoretical explanation for the spreading of synchronization are presented.

  18. Magnetic-Field-Induced Martensitic Transformation of Off-Stoichiometric Single-Crystal Ni2MnGa

    Microsoft Academic Search

    Kazuko Inoue; Yasuo Yamaguchi; Yoshinobu Ishii; Hiroki Yamauchi; Toetsu Shishido

    2009-01-01

    The effect of a magnetic field on the martensitic transformation of an off-stoichiometric Heusler type Ni2.16Mn0.78Ga1.06 single crystal has been revealed by neutron diffraction. The alloy undergoes a martensitic transformation at room temperature, which is nearly coincident with its Curie temperature. Splitting of the cubic (020) peak on the reciprocal lattice cubic c*-plane was traced at 293 K by a

  19. Muon Spin Relaxation Studies of Magnetic-Field-Induced Effects in High-Tc Superconductors A. T. Savici,1

    E-print Network

    Weston, Ken

    :875Ba0:125CuO4, existing well above Tc and TN. The susceptibility counterpart of Cu spin polarization the presence of dynamic antiferromagnetic spin correlations inside vortex cores. There remain, however, many it occur ex- clusively in vortex cores or everywhere in the system? Is this phenomenon generic to all

  20. Order Nidovirales

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter, entitled "Order Nidovirales", is for inclusion in the Ninth Report of the International Committee on Taxonomy of Viruses (ICTV), to be published as both a single volume text and online. The chapter details the taxonomy of members of the Nidovirus order, including family Arteriviridae o...

  1. Social orders

    Microsoft Academic Search

    Norman Schofield

    2010-01-01

    This review discusses the stability of social orders in light of the recent work Violence and Social Orders by Douglass North, John Wallis and Barry Weingast (hereafter NWW). The purpose of this book was to understand the two great\\u000a transitions that have occurred in human society. The first, the agricultural revolution, resulted in a transition from hunter–gather society to what

  2. Spin-orbit coupling in octamers in the spinel sulfide CuIr2S4: Competition between spin-singlet and quadrupolar states and its relevance to remnant paramagnetism

    NASA Astrophysics Data System (ADS)

    Nasu, Joji; Motome, Yukitoshi

    2014-07-01

    We theoretically investigate magnetic properties in the low-temperature phase with the formation of eight-site clusters, octamers, in the spinel compound CuIr2S4. The octamer state was considered to be a spin-singlet state induced by a Peierls instability through the strong anisotropy of d orbitals, the so-called orbital Peierls state. We reexamine this picture by taking into account the spin-orbit coupling, which was ignored in the previous study. We derive a low-energy effective model between jeff=1/2 quasispins on Ir4+ cations in an octamer from the multiorbital Hubbard model with the strong spin-orbit coupling by performing the perturbation expansion from the strong correlation limit. The effective Hamiltonian is in the form of the Kitaev-Heisenberg model but with an additional interaction, a symmetric off-diagonal exchange interaction originating from the perturbation process including both d-d and d-p-d hoppings. Analyzing the effective Hamiltonian on two sites and the octamer by the exact diagonalization, we find that there is competition between a spin-singlet state and a quadrupolar state. The former singlet state is a conventional one, adiabatically connected to the orbital Peierls state. On the other hand, the latter quadrupolar state is stabilized by the additional interaction, which consists of a linear combination of different total spin momenta along the spin quantization axis. In the competing region, the model exhibits paramagnetic behavior with a renormalized small effective moment at low temperature. This peculiar remnant paramagnetism is not obtained in the Kitaev-Heisenberg model without the additional interaction. Our results renew the picture of the octamer state and provide a scenario for the intrinsic paramagnetic behavior recently observed in a muon spin rotation experiment [K. M. Kojima et al., Phys. Rev. Lett. 112, 087203 (2014)]., 10.1103/PhysRevLett.112.087203

  3. Theory and computation of directional nematic phase ordering.

    PubMed

    Soulé, Ezequiel R; Abukhdeir, Nasser Mohieddin; Rey, Alejandro D

    2009-02-01

    A computational study of morphological instabilities of a two-dimensional nematic front under directional growth was performed using a Landau-de Gennes-type quadrupolar tensor order parameter model for the first-order isotropic-nematic transition of 5CB (pentyl-cyanobiphenyl). A previously derived energy balance, taking anisotropy into account, was utilized to account for latent heat and an imposed morphological gradient in the time-dependent model. Simulations were performed using an initially homeotropic isotropic-nematic interface. Thermal instabilities in both the linear and nonlinear regimes were observed and compared to past experimental and theoretical observations. A sharp-interface model for the study of linear morphological instabilities, taking into account additional complexity resulting from liquid-crystalline order, was derived. Results from the sharp-interface model were compared to those from full two-dimensional simulation identifying the specific limitations of simplified sharp-interface models for this liquid-crystal system. In the nonlinear regime, secondary instabilities were observed to result in the formation of defects, interfacial heterogeneities, and bulk texture dynamics. PMID:19391760

  4. In Order

    NSDL National Science Digital Library

    This activity helps students develop a sense of the relative size of quantities in the categories of temperature, speed, time duration and loudness. Learners rank their estimates of given measures in order from least to greatest and justify their decisions. Students are encouraged to do research and carry out experiments when possible. The Teachers' Notes page includes suggestions for implementation, discussion questions, ideas for extension and support, and links to related activities.

  5. Neutron-diffraction study of stripe order in La{sub 2}NiO{sub 4+{delta}} with {delta}= (2) /(15)

    SciTech Connect

    Wochner, P.; Tranquada, J.M. [Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)] [Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Buttrey, D.J. [Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716 (United States)] [Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716 (United States); Sachan, V. [Materials Science Program, University of Delaware, Newark, Delaware 19716 (United States)] [Materials Science Program, University of Delaware, Newark, Delaware 19716 (United States)

    1998-01-01

    We report a detailed neutron-scattering study of the ordering of spins and holes in oxygen-doped La{sub 2}NiO{sub 4.133}. The single-crystal sample exhibits the same oxygen-interstitial order but better defined charge-stripe order than that studied previously in crystals with {delta}=0.125. In particular, charge order is observed up to a temperature at least twice that of the magnetic transition, T{sub m}=110.5 K. On cooling through T{sub m}, the wave vector {epsilon}, equal to half the charge-stripe density within an NiO{sub 2} layer, jumps discontinuously from (1) /(3) to 0.2944. It continues to decrease with further cooling, showing several lock-in transitions on the way down to low temperature. To explain the observed lock-ins, a model is proposed in which each charge stripe is centered on either a row of Ni or a row of O ions. The model is shown to be consistent with the l dependence of the magnetic peak intensities and with the relative intensities of the higher-order magnetic satellites. Analysis of the latter also provides evidence that the magnetic domain walls (charge stripes) are relatively narrow. In combination with a recent study of magnetic-field-induced effects, we find that the charge stripes are all O centered at T{gt}T{sub m}, with a shift towards Ni centering at T{lt}T{sub m}. Inferences concerning the competing interactions responsible for the temperature dependence of {epsilon} and the localization of charge within the stripes are discussed. {copyright} {ital 1998} {ital The American Physical Society}

  6. Order Phasmatodea

    NSDL National Science Digital Library

    Moxey, Carl F.

    Carl Moxey of Northeastern University has created this work-in-progress Web site to provide "a comprehensive archive of information on the systematics and morphology of the insects belonging to the Order Phasmatodea." Carefully designed and easy to navigate, this Web site allows users to browse a collapsible classification tree, locate information by genera or species, view descriptions of phasmatid morphology, and more. Even though only a few translations available so far, some links provided for described genera and species lead to a related German Web site. Moxey encourages users to contribute illustrations and literature citations not already included in the site.

  7. Hyperfine interactions in titanates: Study of orbital ordering and local magnetic properties

    SciTech Connect

    Agzamova, P. A., E-mail: polina_agzamova@usu.ru; Leskova, Yu. V.; Nikiforov, A. E. [Ural Federal University (Russian Federation)

    2013-05-15

    Hyperfine magnetic fields induced on the nuclei of nonmagnetic ions {sup 139}La and {sup 89}Y in LaTiO{sub 3} and YTiO{sub 3}, respectively, have been microscopically calculated. The dependence of the hyperfine fields on the orbital and magnetic structures of the compounds under study has been analyzed. The comparative analysis of the calculated and known experimental data confirms the existence of the static orbital structure in lanthanum and yttrium titanates.

  8. Exotic phases induced by strong spin-orbit coupling in ordered double perovskites

    NASA Astrophysics Data System (ADS)

    Chen, Gang; Pereira, Rodrigo; Balents, Leon

    2010-11-01

    We construct and analyze a microscopic model for insulating rocksalt ordered double perovskites, with the chemical formula A2BB'O6 , where the B' atom has a 4d1 or 5d1 electronic configuration and forms a face-centered-cubic lattice. The combination of the triply degenerate t2g orbital and strong spin-orbit coupling forms local quadruplets with an effective spin moment j=3/2 . Moreover, due to strongly orbital-dependent exchange, the effective spins have substantial biquadratic and bicubic interactions (fourth and sixth order in the spins, respectively). This leads, at the mean-field level, to three main phases: an unusual antiferromagnet with dominant octupolar order, a ferromagnetic phase with magnetization along the [110] direction, and a nonmagnetic but quadrupolar ordered phase, which is stabilized by thermal fluctuations and intermediate temperatures. All these phases have a two-sublattice structure described by the ordering wave vector Q=2?(001) . We consider quantum fluctuations and argue that in the regime of dominant antiferromagnetic exchange, a nonmagnetic valence-bond solid or quantum-spin-liquid state may be favored instead. Candidate quantum-spin-liquid states and their basic properties are described. We also address the effect of single-site anisotropy driven by lattice distortions. Existing and possible future experiments are discussed in light of these results.

  9. Acoustic assisted actuation of Ni-Mn-Ga ferromagnetic shape memory alloys

    E-print Network

    Peterson, Bradley William

    2006-01-01

    Ferromagnetic shape memory alloys (FSMA) have been shown in recent work to exhibit large magnetic field induced strains. The material generally requires a large threshold field (of order 3-4 kOe) to initiate the strain. ...

  10. Variable Order and Distributed Order Fractional Operators

    NASA Technical Reports Server (NTRS)

    Lorenzo, Carl F.; Hartley, Tom T.

    2002-01-01

    Many physical processes appear to exhibit fractional order behavior that may vary with time or space. The continuum of order in the fractional calculus allows the order of the fractional operator to be considered as a variable. This paper develops the concept of variable and distributed order fractional operators. Definitions based on the Riemann-Liouville definitions are introduced and behavior of the operators is studied. Several time domain definitions that assign different arguments to the order q in the Riemann-Liouville definition are introduced. For each of these definitions various characteristics are determined. These include: time invariance of the operator, operator initialization, physical realization, linearity, operational transforms. and memory characteristics of the defining kernels. A measure (m2) for memory retentiveness of the order history is introduced. A generalized linear argument for the order q allows the concept of "tailored" variable order fractional operators whose a, memory may be chosen for a particular application. Memory retentiveness (m2) and order dynamic behavior are investigated and applications are shown. The concept of distributed order operators where the order of the time based operator depends on an additional independent (spatial) variable is also forwarded. Several definitions and their Laplace transforms are developed, analysis methods with these operators are demonstrated, and examples shown. Finally operators of multivariable and distributed order are defined in their various applications are outlined.

  11. Na order and Co charge disproportionation in NaxCoO2

    NASA Astrophysics Data System (ADS)

    Mukhamedshin, I. R.; Alloul, H.

    2015-03-01

    We have synthesized and characterized different stable phases of sodium cobaltates NaxCoO2 with sodium content 0.65 < x < 0.80. We demonstrate that 23Na NMR allows us to determine the difference in the susceptibility of the phases and reveals the presence of Na order in each phase. 59Co NMR experiments give clear evidence that Co charge disproportionation is a dominant feature of Na cobaltates. Only a small fraction (?25%) of cobalt are in a non-magnetic Co3+ charge state whereas electrons delocalize on the other cobalt. The magnetic and charge properties of the different Co sites are highly correlated with each other as their magnetic shift KZZ scales linearly with their quadrupolar frequency ?Q. This reflects the fact that the hole content on the Co orbitals varies from site to site. The unusual charge differentiation found in this system calls for better theoretical understanding of the incidence of the Na atomic order on the electronic structures of these compounds.

  12. High magnetic field induced spin flip/flop behavior and magnetic phase diagram of CuFe1-xGaxO2

    NASA Astrophysics Data System (ADS)

    Shi, L. R.; Xia, Z. C.; Jin, Z.; Wei, M.; Huang, J. W.; Chen, B. R.; Xiao, L. X.; Zuo, H. K.; Ouyang, Z. W.

    2014-11-01

    The structure and magnetic properties of non-magnetic Ga3+ ion doped CuFe1-xGaxO2 (x=0, 0.03, and 0.05) single crystal samples were investigated. X-ray diffraction patterns analysis confirms that the samples are single-phase crystallizing. Doping effect on the magnetic behavior of the ground state and the field-induced spin flip/flop transitions were detected. The transition temperatures and critical magnetic fields of the spin flip/flop, as well as the magnetic hysteresis directly depend on the Ga3+ doping level. Such doping effects may associate with the competition between dilution effect (partial release of spin frustration) and the induced local magnetic moment, which is the result of the changed magnetic coupling both inter- and intra-planes of Fe ions. Based on the experimental results, the effects of Ga3+ doping on the spin flip/flop behavior and a detailed high field magnetic diagram were assumed.

  13. PHYSICAL REVIEW B 89, 165120 (2014) Magnetic-field-induced shift of the optical band gap in Ni3V2O8

    E-print Network

    reveal field-induced blue shifts of the band gap that are much larger than that of the Zeeman effect in the optical properties requires reaching beyond traditional mechanisms like the Zeeman effect to include]. The magnetic field also drives changes in the electronic properties. This effect can be as simple

  14. Magnetic-field-induced exchange effects between Mn ions and free carriers in ZnSe quantum wells through the intermediate nonmagnetic barrier studied by photoluminescence

    NASA Astrophysics Data System (ADS)

    Zayachuk, D. M.; Slobodskyy, T.; Astakhov, G. V.; Slobodskyy, A.; Gould, C.; Schmidt, G.; Ossau, W.; Molenkamp, L. W.

    2011-02-01

    Photoluminescence (PL) of 50 nm Zn0.9Be0.05Mn0.05Se/d nm Zn0.943Be0.057Se/2.5 nm ZnSe/30 nm Zn0.943Be0.057Se structures is investigated as a function of magnetic field (B) and thickness (d) of an intermediate Zn0.943Be0.057Se nonmagnetic barrier between the Zn0.9Be0.05Mn0.05Se semimagnetic barrier and the ZnSe quantum well at a temperature of 1.2 K. The rate of the shift of different PL bands of the structures under study is estimated in low and high magnetic fields. The causes of the shift rate increase under a pass from low to high magnetic fields are interpreted. The peculiarities of the effect of the intermediate barrier on the luminescence properties of the structures are presented. It is shown that deformation of adjacent layers by the barrier plays a crucial role in the formation of these properties, especially in forming the Mn complexes in the Zn0.9Be0.05Mn0.05Se layer. The change of the band gap as well as of the donor and acceptor level energies under the effect of biaxial compression of the Zn0.9Be0.05Mn0.05Se layer by the Zn0.943Be0.057Se are estimated. It is concluded that the Zn0.943Be0.057Se intermediate barrier also appreciably changes the effect of giant Zeeman splitting of the semimagnetic Zn0.9Be0.05Mn0.05Se barrier energy levels on the movement of the energy levels of the ZnSe quantum well in a magnetic field and on the polarization of the quantum-well exciton emission.

  15. Magnetic field-induced exchange effects between Mn ions and free carriers in ZnSe quantum well through the intermediate nonmagnetic barrier studied by photoluminescence

    Microsoft Academic Search

    D. M. Zayachuk; T. Slobodskyy; G. V. Astakhov; A. Slobodskyy; C. Gould; G. Schmidt; W. Ossau; L. W. Molenkamp

    2010-01-01

    Photoluminescence (PL) of the 50 nm $Zn_{0.9}Be_{0.05}Mn_{0.05}Se$\\/ $d$ nm\\u000a$Zn_{0.943}Be_{0.057}Se$\\/ 2.5 nm $ZnSe$\\/ 30 nm $Zn_{0.943}Be_{0.057}Se$\\u000astructures is investigated as a function of magnetic field ($B$) and thickness\\u000a($d$) of intermediate $Zn_{0.943}Be_{0.057}Se$ nonmagnetic barrier between the\\u000a$Zn_{0.9}Be_{0.05}Mn_{0.05}Se$ semimagnetic barrier and $ZnSe$ quantum well at\\u000athe temperature 1.2 K. The rate of the shift of different PL bands of the\\u000astructures

  16. Magnetic-field-induced exchange effects between Mn ions and free carriers in ZnSe quantum wells through the intermediate nonmagnetic barrier studied by photoluminescence

    Microsoft Academic Search

    D. M. Zayachuk; T. Slobodskyy; G. V. Astakhov; A. Slobodskyy; C. Gould; G. Schmidt; W. Ossau; L. W. Molenkamp

    2011-01-01

    Photoluminescence (PL) of 50 nm Zn0.9Be0.05Mn0.05Se\\/d nm Zn0.943Be0.057Se\\/2.5 nm ZnSe\\/30 nm Zn0.943Be0.057Se structures is investigated as a function of magnetic field (B) and thickness (d) of an intermediate Zn0.943Be0.057Se nonmagnetic barrier between the Zn0.9Be0.05Mn0.05Se semimagnetic barrier and the ZnSe quantum well at a temperature of 1.2 K. The rate of the shift of different PL bands of the structures under

  17. Magnetic Field-Induced Precipitation Behaviors of Alloy Carbides M2C, M3C, and M6C in a Molybdenum-Containing Steel

    NASA Astrophysics Data System (ADS)

    Hou, T. P.; Li, Y.; Zhang, Y. D.; Wu, K. M.

    2014-05-01

    The effect of a 12-T high magnetic field on alloy carbide precipitation in an Fe-C-Mo alloy during tempering at an intermediate temperature was investigated. Thin foils and carbon extraction replicas of the treated specimens were examined by transmission electron microscopy (TEM). The results show that the applied high field effectively promoted the precipitation of (Fe,Mo)6C alloy carbide. The concentration of Fe atom in Fe6- x Mo x C carbide is increased whereas that of Mo atom decreased when the high magnetic field was applied. However, the high magnetic field almost had no detectable influence on the atom concentration in (Fe,Mo)2C and (Fe,Mo)3C carbides. First principle calculations have been performed to calculate the magnetic moment per iron atom of the carbides to explore the origin of the effect of the magnetic field. The influence of the high magnetic field on the precipitation behaviors of alloy carbides was closely related to the magnetic moment of (Fe,Mo)2C, (Fe,Mo)3C, and (Fe,Mo)6C. The magnetic field promotes the formation of the carbides with high total magnetic moment. The effect of the high magnetic field on the substitutional solute atom (Fe and Mo) concentration change in the three alloy carbides was attributed to their magnetization differences per Fe atom.

  18. Neutron diffraction study of magnetic field induced behavior in the heavy Fermion Ce3Co4Sn13

    SciTech Connect

    Christianson, Andrew D [ORNL; Goremychkin, E. A. [ISIS Facility, Rutherford Appleton Laboratory; Gardner, J. S. [Indiana University; Kang, H. J. [National Institute of Standards and Technology (NIST); Chung, J.-H. [National Institute of Standards and Technology (NIST); Manuel, P. [ISIS Facility, Rutherford Appleton Laboratory; Thompson, J. D. [Los Alamos National Laboratory (LANL); Sarrao, J. L. [Los Alamos National Laboratory (LANL); Lawrence, J. M. [University of California, Irvine

    2008-01-01

    The specific heat of Ce3Co4Sn13 exhibits a crossover from heavy Fermion behavior with antiferromagnetic correlations at low field to single impurity Kondo behavior above 2 T. We have performed neutron diffraction measurements in magnetic fields up to 6 Tesla on single crystal samples. The (001) position shows a dramatic increase in intensity in field which appears to arise from static polarization of the 4f level and which at 0.14 K also exhibits an anomaly near 2T reflecting the crossover to single impurity behavior.

  19. Magnetic-field-induced cavity polariton linewidth reduction in a GaAs\\/Al0.1Ga0.9As microcavity

    Microsoft Academic Search

    R. Harel; E. Cohen; Arza Ron; E. Linder; L. N. Pfeiffer

    1999-01-01

    The magnetic-field (B<=7 T) effect on the cavity polaritons linewidth is studied by reflection spectroscopy at T=2-5 K. The structure under study consists of a single 160-Å GaAs\\/AlAs quantum well (QW) embedded in a lambda-wide Al0.1Ga0.9As microcavity (MC) that is cladded by Al0.1Ga0.9As\\/AlAs distributed Bragg reflectors. The QW absorption above the QW band gap, E>E(e1-hh1), is flat and it transforms

  20. Magnetic field-induced shift of the optical band gap in Ni3V2O8 B. S. Holinsworth,1

    E-print Network

    -induced blue shifts of the band gap that are much larger than that of the Zeeman effect in isolation properties. This effect can be as simple as the textbook case of Zeeman splitting of an isolated atom10-induced changes in the optical properties requires reaching beyond traditional mechanisms like the Zeeman effect

  1. Magnetic-Field Induced Phase Transitions in a Weakly Coupled s=1/2 Quantum Spin Dimer System Ba3Cr2O8

    NASA Astrophysics Data System (ADS)

    Kofu, M.; Ueda, H.; Nojiri, H.; Oshima, Y.; Zenmoto, T.; Rule, K. C.; Gerischer, S.; Lake, B.; Batista, C. D.; Ueda, Y.; Lee, S.-H.

    2009-05-01

    By using bulk magnetization, electron spin resonance (ESR), heat capacity, and neutron scattering techniques, we characterize the thermodynamic and quantum phase diagrams of Ba3Cr2O8. Our ESR measurements indicate that the low field paramagnetic ground state is a mixed state of the singlet and the Sz=0 triplet for H?c. This suggests the presence of an intradimer Dzyaloshinsky-Moriya (DM) interaction with a DM vector perpendicular to the c axis.

  2. Higher order decompositions of ordered operator exponentials

    NASA Astrophysics Data System (ADS)

    Wiebe, Nathan; Berry, Dominic; Høyer, Peter; Sanders, Barry C.

    2010-01-01

    We present a decomposition scheme based on Lie-Trotter-Suzuki product formulae to approximate an ordered operator exponential with a product of ordinary operator exponentials. We show, using a counterexample, that Lie-Trotter-Suzuki approximations may be of a lower order than expected when applied to problems that have singularities or discontinuous derivatives of appropriate order. To address this problem, we present a set of criteria that is sufficient for the validity of these approximations, prove convergence and provide upper bounds on the approximation error. This work may shed light on why related product formulae fail to be as accurate as expected when applied to Coulomb potentials.

  3. Minimal Orderings Revisited

    SciTech Connect

    Peyton, B.W.

    1999-07-01

    When minimum orderings proved too difficult to deal with, Rose, Tarjan, and Leuker instead studied minimal orderings and how to compute them (Algorithmic aspects of vertex elimination on graphs, SIAM J. Comput., 5:266-283, 1976). This paper introduces an algorithm that is capable of computing much better minimal orderings much more efficiently than the algorithm in Rose et al. The new insight is a way to use certain structures and concepts from modern sparse Cholesky solvers to re-express one of the basic results in Rose et al. The new algorithm begins with any initial ordering and then refines it until a minimal ordering is obtained. it is simple to obtain high-quality low-cost minimal orderings by using fill-reducing heuristic orderings as initial orderings for the algorithm. We examine several such initial orderings in some detail.

  4. First-order inflation

    NASA Technical Reports Server (NTRS)

    Kolb, Edward W.

    1991-01-01

    In the original proposal, inflation occurred in the process of a strongly first-order phase transition. This model was soon demonstrated to be fatally flawed. Subsequent models for inflation involved phase transitions that were second-order, or perhaps weakly first-order; some even involved no phase transition at all. Recently the possibility of inflation during a strongly first-order phase transition has been revived. In this talk I will discuss some models for first-order inflation, and emphasize unique signatures that result if inflation is realized in a first-order transition. Before discussing first-order inflation, I will briefly review some of the history of inflation to demonstrate how first-order inflation differs from other models.

  5. Order Statistic Experiment

    NSDL National Science Digital Library

    Kyle Siegrist

    This resource consists of a Java applet and expository text. The applet simulates the order statistics of a random sample from a given distribution. The sample size, order, and sampling distribution can be specified.

  6. First-order inflation

    SciTech Connect

    Kolb, E.W. (Fermi National Accelerator Lab., Batavia, IL (USA) Chicago Univ., IL (USA). Enrico Fermi Inst.)

    1990-09-01

    In the original proposal, inflation occurred in the process of a strongly first-order phase transition. This model was soon demonstrated to be fatally flawed. Subsequent models for inflation involved phase transitions that were second-order, or perhaps weakly first-order; some even involved no phase transition at all. Recently the possibility of inflation during a strongly first-order phase transition has been revived. In this talk I will discuss some models for first-order inflation, and emphasize unique signatures that result in inflation is realized in a first-order transition. Before discussing first-order inflation, I will briefly review some of the history of inflation to demonstrate how first-order inflation differs from other models. 58 refs., 3 figs.

  7. ASDC Order Tools

    Atmospheric Science Data Center

    2012-04-17

    ... grid format. ASDC Web Ordering Tools Java Tool Help HTML Tool Help These tools allow users to ... or time range. The ordering tool is available in both Java and HTML versions. Reverb Search Tool Reverb ...

  8. Ordered Simple Plot

    NSDL National Science Digital Library

    Plot ordered pairs on the graph, and they will be connected in the order that they are input. This enables you to decide how the pairs should be connected, rather than having the computer connect them from left to right.

  9. Order of Operations Quiz

    NSDL National Science Digital Library

    This activity allows the user to practice order of operations with addition/subtraction, multiplication/division, exponents, and parentheses. Order of Operations Quiz is one of the Interactivate assessment quizzes.

  10. Order of Operations

    NSDL National Science Digital Library

    Mrs. Nieman

    2008-10-05

    Students will learn order of operations. PEMDAS will become a helpful acronym for successfully mastering order of operations. Students will learn the importance of solving problems using order of operations. An acronym will be introduced that will help them remember the order of operations. Interactive guidance and practice will be available for students to access. This tutorial will include the following learning modules: 1) motivation and ...

  11. Order of Operations Four

    NSDL National Science Digital Library

    Students play a generalized version of connect four, gaining the chance to place a piece on the board by answering order of operations questions (addition/subtraction, multiplication/division, exponents, and parentheses). Parameters: time, difficulty level, types of questions. Order of Operations Four is one of the Interactivate assessment games.

  12. Finite Order Statistic Experiment

    NSDL National Science Digital Library

    Kyle Siegrist

    This resource consists of a Java applet and expository text. The applet is a simulation of the experiment of selecting n objects at random from the first m positive integers. The random variables of interest are the order statistics. The applet illustrates the distributions of the order statistics.

  13. Exploring Order of Operations

    NSDL National Science Digital Library

    2012-08-06

    This interactive activity demonstrates the order of operations. The game asks students to click on the correct operation in a series of mathematical problems. Correct answers will increase the user's time for the next game. Students should have some knowledge of the order of operations prior to doing this activity. Two worksheets are also available for print or download in PDF file format.

  14. Bioregions and World Order.

    ERIC Educational Resources Information Center

    Breakthrough, 1985

    1985-01-01

    What bioregions can do to contribute to world order and security is discussed in this newsletter. A bioregion is defined as an identifiable geographical area of interacting life-systems that is relatively self-sustaining in the ever-renewing processes of nature. Articles included are: "Bioregionalism and World Order" (Gerald Mische); "Bioregions:…

  15. Programming Languages: Marching Orders

    NSDL National Science Digital Library

    Tim Bell

    2005-01-01

    In this activity about computer programming, learners follow instructions in a variety of ways in order to successfully draw figures. Through these exercises, learners will experience some of the often frustrating aspects of computer programming.

  16. Court Ordered Desegregation

    ERIC Educational Resources Information Center

    Reber, Sarah J.

    2005-01-01

    The effect of the court ordered desegregation plans, on trends in segregation and white flight, are estimated. The effect of availability of school districts and other factors on the white flight across districts is also mentioned.

  17. Do-not-resuscitate order

    MedlinePLUS

    No code; End-of-life; Do not resuscitate; Do not resuscitate order; DNR; DNR order ... A do-not-resuscitate order, or DNR order, is a medical order written by a doctor. It instructs health care providers ...

  18. Superconductors with Topological Order

    E-print Network

    M. C. Diamantini; P. Sodano; C. A. Trugenberger

    2005-11-18

    We propose a mechanism of superconductivity in which the order of the ground state does not arise from the usual Landau mechanism of spontaneous symmetry breaking but is rather of topological origin. The low-energy effective theory is formulated in terms of emerging gauge fields rather than a local order parameter and the ground state is degenerate on topologically non-trivial manifolds. The simplest example of this mechanism of superconductivty is concretely realized as global superconductivty in Josephson junction arrays.

  19. Compare and Order

    NSDL National Science Digital Library

    Amanda Hayler and Dan Bunker

    2004-01-01

    This interactive Flash applet helps students learn to compare and order objects according to size and weight attributes. The text and voice prompts ask students to compare three objects to find the longest, tallest, shortest, and so on. It then asks them to place three objects in a specified order, such as narrowest to widest. Correct responses are rewarded with a cheer and a summary of the results. One concern for users might be the British accents of the readers.

  20. 19 CFR 210.75 - Proceedings to enforce exclusion orders, cease and desist orders, consent orders, and other...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...exclusion orders, cease and desist orders, consent orders, and other Commission orders...exclusion orders, cease and desist orders, consent orders, and other Commission orders...exclusion order, cease and desist order, or consent order. Such matters may be...

  1. 19 CFR 210.75 - Proceedings to enforce exclusion orders, cease and desist orders, consent orders, and other...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...exclusion orders, cease and desist orders, consent orders, and other Commission orders...exclusion orders, cease and desist orders, consent orders, and other Commission orders...exclusion order, cease and desist order, or consent order. Such matters may be...

  2. 19 CFR 210.75 - Proceedings to enforce exclusion orders, cease and desist orders, consent orders, and other...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...exclusion orders, cease and desist orders, consent orders, and other Commission orders...exclusion orders, cease and desist orders, consent orders, and other Commission orders...exclusion order, cease and desist order, or consent order. Such matters may be...

  3. Ductile ordered intermetallic alloys.

    PubMed

    Liu, C T; Stiegler, J O

    1984-11-01

    Many ordered intermetallic alloys have attractive high-temperature properties; however, low ductility and brittle fracture limit their use for structural applications. The embrittlement in these alloys is mainly caused by an insufficient number of slip systems (bulk brittleness) and poor grain-boundary cohesion. Recent studies have shown that the ductility and fabricability of ordered intermetallics can be substantially improved by alloying processes and control of microstructural features through rapid solidification and thermomechanical treatments. These results demonstrate that the brittleness problem associated with ordered intermetallics can be overcome by using physical metallurgical principles. Application of these principles will be illustrated by results on Ni(3)Al and Ni(3)V-Co(3)V-Fe(3)V. The potential for developing these alloys as a new class of high-temperature structural materials is discussed. PMID:17774926

  4. The cephalopod order Discosorida

    E-print Network

    Flower, R. H.; Teichert, C.

    1957-07-01

    o 1 I UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS MOLLUSCA ARTICLE 6 Pages 1-144, Plates 1-43, Figures 1-34 THE CEPHALOPOD ORDER DISCOSORIDA By ROUSSEAU H. FLOWER and CURT TEICHERT UNIVERSITY OF KANSAS PUBLICATIONS JULY 1, 1957 PRINTED... comprises CONTRIBUTION 21. A list of previously published issues appears at the end of this report. UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS MOLLUSCA, ARTICLE 6, PAGES 1-144, PLATES 1-43, FIGURES 1-34 THE CEPHALOPOD ORDER DISCOSORIDA By ROUSSEAU H...

  5. Education and World Order

    ERIC Educational Resources Information Center

    Jones, Phillip W.

    2007-01-01

    The impact on educational analysis of mainstream international relations (IR) theories is yet to realize its full potential. The problem of education in relation to the construction of world order is considered in relation to core developments in IR theory since the Second World War. In particular, the global architecture of education is seen as a…

  6. Comparing and Ordering Fractions

    NSDL National Science Digital Library

    2007-12-12

    Use area models to compare and order fractions. Also see a visual representation of the least common denominator of two fractions. With the visual representation of the LCD, this Gizmo can be an introduction to adding and subtracting fractions with unlike denominators.

  7. Land and World Order.

    ERIC Educational Resources Information Center

    Mische, Patricia, Ed.; And Others

    1982-01-01

    The papers in this publication discuss the land and how what happens to the land affects us. The publication is one in a series of monographs that examine the linkages between local and global concerns and explore alternative world futures. Examples of topics discussed in the papers follow. The paper "Land and World Order" examines implications of…

  8. Operation Order Algebra Game

    NSDL National Science Digital Library

    2012-01-01

    This interactive game reinforces the importance of the order of operations within equations. Players enter the three numbers on the rocks in the correct box to make a true closed equation. A check answer button provides feedback and there are three levels of difficulty to provide challenge at the student's skill level.

  9. Order: Homoptera Family: Aphididae

    E-print Network

    Liskiewicz, Maciej

    Order: Homoptera Family: Aphididae DESCRIPTION Aphids, or plant lice, are small, soft-bodied insects. There are hundreds of different species of aphids, some of which attack only one host plant while others attack numerous hosts. Most aphids are about 1/10 inch long (2.54 mm), and though green and black

  10. Fractional order junctions

    NASA Astrophysics Data System (ADS)

    Machado, J. Tenreiro

    2015-01-01

    Gottfried Leibniz generalized the derivation and integration, extending the operators from integer up to real, or even complex, orders. It is presently recognized that the resulting models capture long term memory effects difficult to describe by classical tools. Leon Chua generalized the set of lumped electrical elements that provide the building blocks in mathematical models. His proposal of the memristor and of higher order elements broadened the scope of variables and relationships embedded in the development of models. This paper follows the two directions and proposes a new logical step, by generalizing the concept of junction. Classical junctions interconnect system elements using simple algebraic restrictions. Nevertheless, this simplistic approach may be misleading in the presence of unexpected dynamical phenomena and requires including additional “parasitic” elements. The novel ?-junction includes, as special cases, the standard series and parallel connections and allows a new degree of freedom when building models. The proposal motivates the search for experimental and real world manifestations of the abstract conjectures.

  11. Icosahedral order in liquids

    SciTech Connect

    Egami, Takeshi [ORNL

    2007-01-01

    The possibility of icosahedral order in liquids and its role in glass transition is discussed in a broad context of statistical mechanics of liquid. It is pointed out that the structures of glasses and liquids are described both in terms of the topology of atomic bond networks as well as the local distortion of the atomic bonds. While topology plays a dominant role in covalent glasses, local distortion is likely to be more important for metallic glasses.

  12. Higher order Bezier circles

    NASA Technical Reports Server (NTRS)

    Chou, Jin

    1993-01-01

    Rational Bezier and B-spline representations of circles have been heavily publicized. However, all the literature assumes the rational Bezier segments in the homogeneous space are both planar and (equivalent to) quadratic. This creates the illusion that circles can only be achieved by planar and quadratic curves. Circles that are formed by higher order rational Bezier curves which are nonplanar in the homogeneous space are shown. The problem of whether it is possible to represent a complete circle with one Bezier curve is investigated. In addition, some other interesting properties of cubic Bezier arcs are discussed.

  13. Birth order and myopia

    PubMed Central

    Guggenheim, Jeremy A.; McMahon, George; Northstone, Kate; Mandel, Yossi; Kaiserman, Igor; Stone, Richard A.; Lin, Xiaoyu; Saw, Seang Mei; Forward, Hannah; Mackey, David A.; Yazar, Seyhan; Young, Terri L.; Williams, Cathy

    2013-01-01

    Purpose An association between birth order and reduced unaided vision (a surrogate for myopia) has been observed previously. We examined the association between birth order and myopia directly in 4 subject groups. Methods Subject groups were participants in 1) the Avon Longitudinal Study of Parents and Children (ALSPAC; UK; age 15 years; N=4,401), 2) the Singapore Cohort Study of Risk Factors for Myopia (SCORM; Singapore; age 13 years; N=1,959), 3) the Raine Eye Health Study (REHS; Australia; age 20 years; N=1,344), and 4) Israeli Defense Force recruitment candidates (IDFC; Israel; age 16-22 years; N=888,277). Main outcome: Odds ratio (OR) for myopia in first born versus non-first born individuals after adjusting for potential risk factors. Results The prevalence of myopia was numerically higher in first-born versus non-first-born individuals in all study groups, but the strength of evidence varied widely. The adjusted ORs (95% CI) were: ALSPAC, 1.31 (1.05-1.64); SCORM, 1.25 (0.89-1.77); REHS, 1.18 (0.90-1.55); IDFC, 1.04 (1.03-1.06). In the large IDFC sample, the effect size was greater (a) for the first born versus fourth or higher born comparison than for the first born versus second/third born comparison (P<0.001) and (b) with increasing myopia severity (P<0.001). Conclusions Across all studies, the increased risk of myopia in first born individuals was low (OR <1.3). Indeed, only the studies with >4000 participants provided strong statistical support for the association. The available evidence suggested the relationship was independent of established risk factors such as time outdoors/reading, and thus may arise through a different causal mechanism. PMID:24168726

  14. Order in Spontaneous Behavior

    PubMed Central

    Maye, Alexander; Hsieh, Chih-hao; Sugihara, George; Brembs, Björn

    2007-01-01

    Brains are usually described as input/output systems: they transform sensory input into motor output. However, the motor output of brains (behavior) is notoriously variable, even under identical sensory conditions. The question of whether this behavioral variability merely reflects residual deviations due to extrinsic random noise in such otherwise deterministic systems or an intrinsic, adaptive indeterminacy trait is central for the basic understanding of brain function. Instead of random noise, we find a fractal order (resembling Lévy flights) in the temporal structure of spontaneous flight maneuvers in tethered Drosophila fruit flies. Lévy-like probabilistic behavior patterns are evolutionarily conserved, suggesting a general neural mechanism underlying spontaneous behavior. Drosophila can produce these patterns endogenously, without any external cues. The fly's behavior is controlled by brain circuits which operate as a nonlinear system with unstable dynamics far from equilibrium. These findings suggest that both general models of brain function and autonomous agents ought to include biologically relevant nonlinear, endogenous behavior-initiating mechanisms if they strive to realistically simulate biological brains or out-compete other agents. PMID:17505542

  15. Order in dense hydrogen at low temperatures

    PubMed Central

    Edwards, B.; Ashcroft, N. W.

    2004-01-01

    By increase in density, impelled by pressure, the electronic energy bands in dense hydrogen attain significant widths. Nevertheless, arguments can be advanced suggesting that a physically consistent description of the general consequences of this electronic structure can still be constructed from interacting but state-dependent multipoles. These reflect, in fact self-consistently, a disorder-induced localization of electron states partially manifesting the effects of proton dynamics; they retain very considerable spatial inhomogeneity (as they certainly do in the molecular limit). This description, which is valid provided that an overall energy gap has not closed, leads at a mean-field level to the expected quadrupolar coupling, but also for certain structures to the eventual emergence of dipolar terms and their coupling when a state of broken charge symmetry is developed. A simple Hamiltonian incorporating these basic features then leads to a high-density, low-temperature phase diagram that appears to be in substantial agreement with experiment. In particular, it accounts for the fact that whereas the phase I–II phase boundary has a significant isotope dependence, the phase II–III boundary has very little. PMID:15028839

  16. Visibility-ordering meshed polyhedra

    Microsoft Academic Search

    Peter L. Williams

    1992-01-01

    A visibility-ordering of a set of objects from some viewpoint is an ordering such that if object a obstructs object b, then b precedes a in the ordering. An algorithm is presented that generates a visibility-ordering of an acyclic convex set of meshed convex polyhedra. This algorithm takes time linear in the size of the mesh. Modifications to this algorithm

  17. Course Syllabus Model Order Reduction

    E-print Network

    Noelle, Sebastian

    Course Syllabus Model Order Reduction Motivation Reduced Basis Method Model Order Reduction Sommersemester 2013 1 / 64 #12;Course Syllabus Model Order Reduction Motivation Reduced Basis Method General Credits) Final exam (oral) Date to be determined 2 / 64 #12;Course Syllabus Model Order Reduction

  18. Protective orders: questions and conundrums.

    PubMed

    Logan, T K; Shannon, Lisa; Walker, Robert; Faragher, Teri Marie

    2006-07-01

    Current media portrayal of protective orders is often negative, focusing on weaknesses in how protective orders are obtained and enforced. This review of research findings on protective orders examines issues and suggests areas in need of future research to clarify and improve public policy. More specifically, this review has five main objectives: (a) to provide background information about partner violence and the need for protective orders; (b) to describe what protective orders are, how many women obtain them, and the advantages and disadvantages of obtaining protective orders; (c) to examine characteristics of women who seek protective orders; (d) to explore research on whether protective orders actually increase women's safety; and (e) to highlight opportunities and gaps in the practice and research literature regarding the use of protective orders for women with violent partners or ex-partners. PMID:16785286

  19. Topology in Ordered Phases

    NASA Astrophysics Data System (ADS)

    Tanda, Satoshi; Matsuyama, Toyoki; Oda, Migaku; Asano, Yasuhiro; Yakubo, Kousuke

    2006-08-01

    I. Topology as universal concept. Optical vorticulture / M. V. Berry. On universality of mathematical structure in nature: topology / T. Matsuyama. Topology in physics / R. Jackiw. Isoholonomic problem and holonomic quantum computation / S. Tanimura -- II. Topological crystals. Topological crystals of NbSe[symbol] / S. Tanda ... [et al.]. Superconducting states on a Möbius strip / M. Hayashi ... [et al.]. Structure analyses of topological crystals using synchrotron radiation / Y. Nogami ... [et al.]. Transport measurement for topological charge density waves / T. Matsuura ... [et al.]. Theoretical study on Little-Parks oscillation in nanoscale superconducting ring / T. Suzuki, M. Hayashi and H. Ebisawa. Frustrated CDW states in topological crystals / K. Kuboki ... [et al.]. Law of growth in topological crystal / M. Tsubota ... [et al.]. Synthesis and electric properties of NbS[symbol]: possibility of room temperature charge density wave devices / H. Nobukane ... [et al.]. How does a single crystal become a Möbius strip? / T. Matsuura ... [et al.]. Development of X-ray analysis method for topological crystals / K. Yamamoto ... [et al.] -- III. Topological materials. Femtosecond-timescale structure dynamics in complex materials: the case of (NbSe[symbol])[symbol]I / D. Dvorsek and D. Mihailovic. Ultrafast dynamics of charge-density-wave in topological crystals / K. Shimatake ... [et al.]. Topology in morphologies of a folded single-chain polymer / Y. Takenaka, D. Baigl and K. Yoshikawa. One to two-dimensional conversion in topological crystals / T. Toshima, K. Inagaki and S. Tanda. Topological change of Fermi surface in Bismuth under high pressure / M. Kasami ... [et al.]. Topological change of 4, 4'-bis[9-dicarbazolyl]-2, 2'-biphenyl (CBP) by international rearrangement / K. S. Son ... [et al.]. Spin dynamics in Heisenberg triangular system VI5 cluster studied by [symbol]H-NMR / Y. Furukawa ... [et al.]. STM/STS on NbSe[symbol] nanotubes / K. Ichimura ...[et al.]. Nanofibers of hydrogen storage alloy / I. Saita ... [et al.]. Synthesis of stable icosahedral quasicrystals in Zn-Sc based alloys and their magnetic properties / S. Kashimoto and T. Ishimasa. One-armed spiral wave excited by eam pressure in accretion disks in Be/X-Ray binaries / K. Hayasaki and A. T. Okazaki -- IV. Topological defects and excitations. Topological excitations in the ground state of charge density wave systems / P. Monceau. Soliton transport in nanoscale charge-density-wave systems / K. Inagaki, T. Toshima and S. Tanda. Topological defects in triplet superconductors UPt3, Sr[symbol]RuO[symbol], etc. / K. Maki ... [et al.]. Microscopic structure of vortices in type II superconductors / K. Machida ... [et al.]. Microscopic neutron investigation of the Abrikosov state of high-temperature superconductors / J. Mesot. Energy dissipation at nano-scale topological defects of high-Tc superconductors: microwave study / A. Maeda. Pressure induced topological phase transition in the heavy Fermion compound CeAl[symbol] / H. Miyagawa ... [et al.]. Explanation for the unusual orientation of LSCO square vortex lattice in terms of nodal superconductivity / M. Oda. Local electronic states in Bi[symbol]Sr[symbol]CaCu[symbol]O[symbol] / A. Hashimoto ... [et al.] -- V. Topology in quantum phenomena. Topological vortex formation in a Bose-Einstein condensate of alkali-metal atoms / M. Nakahara. Quantum phase transition of [symbol]He confined in nano-porous media / K. Shirahama, K. Yamamoto and Y. Shibayama. A new mean-field theory for Bose-Einstein condensates / T. Kita. Spin current in topological cristals / Y. Asano. Antiferromagnetic defects in non-magnetic hidden order of the heavy-electron system URu[symbol]Si[symbol] / H. Amitsuka, K. Tenya and M. Yokoyama. Magnetic-field dependences of thermodynamic quantities in the vortex state of Type-II superconductors / K. Watanabe, T. Kita and M. Arai. Three-magnon-mediated nuclear spin relaxation in quantum ferrimagnets of topological origin / H. Hori and S, Yamamoto. Topological aspects of wave function statistics at t

  20. Nielsen-Thurston orderings and the space of braid orderings

    E-print Network

    Navas, Andres

    2009-01-01

    We study the topological space of left-orderings of the braid group, and its subspace of Nielsen-Thurston orderings. Our main result is that no Nielsen-Thurston ordering is isolated in the space of braid orderings. In the course of the proof, we classify the convex subgroups and calculate the Conradian soul for any Nielsen-Thurston ordering of B_n. We also prove that for a large class of Nielsen-Thurston orderings, including all those of infinite type, a stronger result holds: they are approximated by their own conjugates. On the other hand, we suggest an example of a Nielsen-Thurston ordering which may not be approximated by its conjugates.

  1. Order Handling in Convergent Environments

    E-print Network

    Vrtanoski, Jordan

    2012-01-01

    The rapid development of IT&T technology had big impact on the traditional telecommunications market, transforming it from monopolistic market to highly competitive high-tech market where new services are required to be created frequently. This paper aims to describe a design approach that puts order management process (as part of enterprise application integration) in function of rapid service creation. In the text we will present a framework for collaborative order handling supporting convergent services. The design splits the order handling processes in convergent environments in three business process groups: order capture, order management and order fulfillment. The paper establishes abstract framework for order handling and provides design guidelines for transaction handling implementation based on the checkpoint and inverse command strategy. The proposed design approach is based in a convergent telecommunication environment. Same principles are applicable in solving problems of collaboration in fun...

  2. Default settings of computerized physician order entry system order sets drive ordering habits

    PubMed Central

    Olson, Jordan; Hollenbeak, Christopher; Donaldson, Keri; Abendroth, Thomas; Castellani, William

    2015-01-01

    Background: Computerized physician order entry (CPOE) systems are quickly becoming ubiquitous, and groups of orders (“order sets”) to allow for easy order input are a common feature. This provides a streamlined mechanism to view, modify, and place groups of related orders. This often serves as an electronic equivalent of a specialty requisition. A characteristic, of these order sets is that specific orders can be predetermined to be “preselected” or “defaulted-on” whenever the order set is used while others are “optional” or “defaulted-off” (though there is typically the option is to “deselect” defaulted-on tests in a given situation). While it seems intuitive that the defaults in an order set are often accepted, additional study is required to understand the impact of these “default” settings in an order set on ordering habits. This study set out to quantify the effect of changing the default settings of an order set. Methods: For quality improvement purposes, order sets dealing with transfusions were recently reviewed and modified to improve monitoring of outcome. Initially, the order for posttransfusion hematocrits and platelet count had the default setting changed from “optional” to “preselected.” The default settings for platelet count was later changed back to “optional,” allowing for a natural experiment to study the effect of the default selections of an order set on clinician ordering habits. Results: Posttransfusion hematocrit values were ordered for 8.3% of red cell transfusions when the default order set selection was “off” and for 57.4% of transfusions when the default selection was “preselected” (P < 0.0001). Posttransfusion platelet counts were ordered for 7.0% of platelet transfusions when the initial default order set selection was “optional,” increased to 59.4% when the default was changed to “preselected” (P < 0.0001), and then decreased to 7.5% when the default selection was returned to “optional.” The posttransfusion platelet count rates during the two “optional” periods: 7.0% versus 7.5% – were not statistically different (P = 0.620). Discussion: Default settings in CPOE order sets can significantly influence physician selection of laboratory tests. Careful consideration by all stakeholders, including clinicians and pathologists, should be obtained when establishing default settings in order sets.

  3. Ordered delinquency: the "effects" of birth order on delinquency.

    PubMed

    Cundiff, Patrick R

    2013-08-01

    Juvenile delinquency has long been associated with birth order in popular culture. While images of the middle child acting out for attention or the rebellious youngest child readily spring to mind, little research has attempted to explain why. Drawing from Adlerian birth order theory and Sulloway's born-to-rebel hypothesis, I examine the relationship between birth order and a variety of delinquent outcomes during adolescence. Following some recent research on birth order and intelligence, I use new methods that allow for the examination of between-individual and within-family differences to better address the potential spurious relationship. My findings suggest that contrary to popular belief, the relationship between birth order and delinquency is spurious. Specifically, I find that birth order effects on delinquency are spurious and largely products of the analytic methods used in previous tests of the relationship. The implications of this finding are discussed. PMID:23719623

  4. Ordered Delinquency: The “Effects” of Birth Order On Delinquency

    PubMed Central

    Cundiff, Patrick R.

    2014-01-01

    Juvenile delinquency has long been associated with birth order in popular culture. While images of the middle child acting out for attention or the rebellious youngest child readily spring to mind, little research has attempted to explain why. Drawing from Adlerian birth order theory and Sulloway's born to rebel hypothesis I examine the relationship between birth order and a variety of delinquent outcomes during adolescence. Following some recent research on birth order and intelligence, I use new methods that allow for the examination of both between-individual and within-family differences to better address the potential spurious relationship. My findings suggest that contrary to popular belief the relationship between birth order and delinquency is spurious. Specifically, I find that birth order effects on delinquency are spurious and largely products of the analytic methods used in previous tests of the relationship. The implications of this finding are discussed. PMID:23719623

  5. Direct near-field optical imaging of higher order plasmonic resonances.

    PubMed

    Esteban, R; Vogelgesang, R; Dorfmüller, J; Dmitriev, A; Rockstuhl, C; Etrich, C; Kern, K

    2008-10-01

    We map in real space and by purely optical means near-field optical information of localized surface plasmon polariton (LSPP) resonances excited in nanoscopic particles. We demonstrate that careful polarization control enables apertureless scanning near-field optical microscopy (aSNOM) to image dipolar and quadrupolar LSPPs of the bare sample with high fidelity in both amplitude and phase. This establishes a routine method for in situ optical microscopy of plasmonic and other resonant structures under ambient conditions. PMID:18788785

  6. Surface melting of electronic order.

    SciTech Connect

    Wilkins, S. B.; Liu, X.; Wakabayashi, Y.; Kim, J.-W.; Ryan, P. J.; Mitchell, J. F.; Hill, J. P. (Materials Science Division); ( XSD); (BNL); (Osaka Univ.)

    2011-01-01

    We report temperature-dependent surface x-ray scattering studies of the orbital ordered surface in La{sub 0.5}Sr{sub 1.5}MnO{sub 4}. We find that as the bulk ordering temperature is approached from below the thickness of the interface between the electronically ordered and electronically disordered regions at the surface grows, though the bulk correlation length remains unchanged. Close to the transition, the surface is so rough that there is no well-defined electronic surface, despite the presence of bulk electronic order. That is, the electronic ordering at the surface has melted. Above the bulk transition, long-range ordering in the bulk is destroyed but finite-sized isotropic fluctuations persist, with a correlation length roughly equal to that of the low-temperature in-plane surface correlation length.

  7. Counterbalancing for Serial Order Carryover Effects in Experimental Condition Orders

    ERIC Educational Resources Information Center

    Brooks, Joseph L.

    2012-01-01

    Reactions of neural, psychological, and social systems are rarely, if ever, independent of previous inputs and states. The potential for serial order carryover effects from one condition to the next in a sequence of experimental trials makes counterbalancing of condition order an essential part of experimental design. Here, a method is proposed…

  8. s-order nondiagonal quasiprobabilities

    NASA Astrophysics Data System (ADS)

    de Oliveira, Fernando A. M.

    1992-04-01

    This paper presents a correspondence between the annihilation a^ and creation a^° operators and two independent complex variables ? and ?, which makes possible the definition of positive nondiagonal quasiprobabilities for any Cahill-Glauber s order. A generalized version of the Cahill and Glauber s-ordered displacement operator displacing the annihilation and creation operators by ? and ? is defined. Corresponding to this n/Inondiagonal displacement, a nondiagonal ordering operator is introduced so that a map of s-ordered operators into c numbers a^-->?, a^°-->? can be defined. The Drummond-Gardiner projector and the Cahill-Glauber diagonal ordering operator are obtained as particular cases. In order to use the nondiagonal correspondence in the determination of quantum expectation values of observables, several families of quasiprobabilities are defined, generalizing Drummond-Gardiner (normal order and nondiagonal) positive-P-function and Cahill-Glauber (s-order and diagonal) quasiprobabilities. It is demonstrated that these nondiagonal quasiprobabilities exist as well-behaved functions where at least one is non-negative, for any state and any order. The time evolution of these quasiprobabilities is discussed both in the Schrödinger and in the Heisenberg pictures. In the Heisenberg picture, a method for obtaining c-number stochastic differential equations (SDE's) directly from operator equations using the s-order nondiagonal correspondence is described. The main difference between this method and the Langevin approach is that in the latter a diagonal correspondence is used, leading eventually to wrong results. The use of these SDE's to solve quantum optical problems is discussed, and an application to the nonlinearly damped degenerate parametric oscillator is made. In order to obtain the SDE, various (inequivalent) truncation schemes are necessary.

  9. 7 CFR 1214.12 - Order.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE CHRISTMAS TREE PROMOTION, RESEARCH, AND INFORMATION ORDER Christmas Tree Promotion, Research, and Information Order Definitions § 1214.12 Order....

  10. 7 CFR 1214.12 - Order.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE CHRISTMAS TREE PROMOTION, RESEARCH, AND INFORMATION ORDER Christmas Tree Promotion, Research, and Information Order Definitions § 1214.12 Order....

  11. 7 CFR 1214.12 - Order.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE CHRISTMAS TREE PROMOTION, RESEARCH, AND INFORMATION ORDER Christmas Tree Promotion, Research, and Information Order Definitions § 1214.12 Order....

  12. 7 CFR 1221.18 - Order.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SORGHUM PROMOTION, RESEARCH, AND INFORMATION ORDER Sorghum Promotion, Research, and Information Order Definitions § 1221.18 Order....

  13. 7 CFR 1221.18 - Order.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SORGHUM PROMOTION, RESEARCH, AND INFORMATION ORDER Sorghum Promotion, Research, and Information Order Definitions § 1221.18 Order....

  14. 7 CFR 1221.18 - Order.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SORGHUM PROMOTION, RESEARCH, AND INFORMATION ORDER Sorghum Promotion, Research, and Information Order Definitions § 1221.18 Order....

  15. 7 CFR 1221.18 - Order.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SORGHUM PROMOTION, RESEARCH, AND INFORMATION ORDER Sorghum Promotion, Research, and Information Order Definitions § 1221.18 Order....

  16. 7 CFR 1221.18 - Order.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SORGHUM PROMOTION, RESEARCH, AND INFORMATION ORDER Sorghum Promotion, Research, and Information Order Definitions § 1221.18 Order....

  17. Magnetic-field-induced reduction of singlet binding energies of off-well-center negative donor ions in GaAs/Al 0.3Ga 0.7As multiple quantum wells

    NASA Astrophysics Data System (ADS)

    Jiang, Z. X.; McCombe, B. D.; Zhu, J.-L.; Schaff, W.

    1998-02-01

    Far-infrared Fourier transform magnetotransmission spectroscopy has been carried out on two GaAs/Al0.3Ga0.7As multiple-quantum-well (MQW) samples with ?-doped Si donors located away from the well centers. Temperature and magnetic field dependence studies have been used to identify the features in the spectra. In contrast to well-center D-ions, the off-well-center D-singlet binding energy decreases with increasing magnetic field between 5.5 T and 15 T as reflected by the decreasing strength of the D- - singlet transition. The D01s-2p+transition increases in strength at the expense of the D-singlet in this field range. These results reflect directly the importance of the repulsive electron-electron interaction in this unique system, where the balance between the electron-electron repulsion and the attractive interactions of the electrons with the positively charged impurity center can be 'tuned' by magnetic field. The experimental results are in good agreement with theoretical predictions.

  18. Magnetic-Field-Induced Reduction of Singlet Binding Energies of Off-Well-Center Negative Donor Ions in GaAs/Al_0.3Ga_0.7As Multiple Quantum Wells

    NASA Astrophysics Data System (ADS)

    Jiang, Z. X.; McCombe, B. D.; Zhu, Jia-Lin; Schaff, W.

    1997-03-01

    Far-infrared Fourier transform magneto-transmission spectroscopy has been carried out on two GaAs/Al_0.3Ga_0.7As multiple-quantum-well (MQW) samples with planar-doped Si donors located away from the well centers. Temperature- and magnetic-field-dependence studies have been used to identify the features in the spectra. In contrast to well-center D^- ions, the off-well-center D^--singlet binding energy decreases with increasing magnetic field between 5.5T and 15T as reflected by the decreasing strength of the D^--singlet transition. The D^0 1s-2p^+ transition increases in strength in this field range. These results reflect directly the importance of the repulsive electron-electron interaction in this unique system, where the balance between the electron-electron repulsion and the attractive interactions of the electrons with the positively charged impurity center can be "tuned" by the magnetic field. Experimental results are in good agreement with theoretical predictions ^1. [1ex] Supported in part by ONR and NSF. [1ex] ^1 Zhu et al. (1994), J. Phys.: Condens. Matter 6, L299-L304.

  19. Large remnant polarization and magnetic field induced destruction of cycloidal spin structure in Bi{sub 1-x}La{sub x}FeO{sub 3} (0 {<=} x {<=} 0.2)

    SciTech Connect

    Yin, L. H.; Yang, J.; Zhao, B. C.; Liu, Y.; Tan, S. G.; Tang, X. W.; Dai, J. M.; Song, W. H. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei 230031, People's Republic of China (China)] [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei 230031, People's Republic of China (China); Sun, Y. P. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei 230031, People's Republic of China (China) [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei 230031, People's Republic of China (China); High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, People's Republic of China (China)

    2013-06-07

    We prepared a series of Bi{sub 1-x}La{sub x}FeO{sub 3} (0 {<=} x {<=} 0.2) ceramics with a sol-gel method and find that both the magnetization and dielectric constant show an abrupt anomaly near a critical field H{sub c}, which is attributed to the destruction of the cycloidal antiferromagnetic spin structure. The critical field H{sub c} decreases substantially from {approx}20 T for the x = 0 sample [Y. F. Popov et al., JETP Lett. 57, 69 (1993)] to {approx}2.8 T for the x = 0.17 sample and finally to 0 T for the x = 0.2 sample at room temperature (RT). It is also found that H{sub c} increases with decreasing temperature. The variation of H{sub c} with La substitution and temperature can be ascribed to the change in the magnetic anisotropy and isotropic superexchange interaction, respectively. We have also discussed the magnetodielectric effects in these samples in terms of the Ginzburg-Landau theory and the spin-phonon model. Moreover, increasing the doping level of La to 0.15 greatly improves the RT leakage-current and ferroelectric (FE) properties. A RT square-shaped FE hysteresis loop with remnant polarization (2P{sub r}) as high as {approx}64 {mu}C/cm{sup 2} is obtained for the x = 0.15 sample. These results may be important for potential applications in BiFeO{sub 3}-based magnetoelectric devices.

  20. Children's Order 10 Years on

    ERIC Educational Resources Information Center

    Kerr, Linda

    2006-01-01

    Ten years ago I wrote an article on the Children's Order, which was coming into force in Northern Ireland in October 1996. I examined the principles behind the Children's Order and considered how these principles interacted with the practice of family mediation (at that stage I was Coordinator of the Family Mediation service). Since that date…

  1. Lepidosauria I. Tuataras (Order Rhynochephalia)

    E-print Network

    Dever, Jennifer A.

    Xenosauridae #12;10 Helodermatidae the only venomous lizards The Gila monster Heloderma suspectum far southwest1 Lepidosauria I. Tuataras (Order Rhynochephalia) II. Order Squamata, phylogeny III. Lizard Have acrodont teeth. Draco Moloch horridus Agama III. Lizard Families ~44 native California lizard

  2. Altera Corporation 1 Ordering Information

    E-print Network

    Berns, Hans-Gerd

    , and the most current on-line and printed documentation. Table 1 explains the ordering codes for the Altera Customer Marketing at (408) 544-7104. Figure 1. Device Package Ordering Information for APEX 20K, APEX 20KE Subscription Program. For information on specific products, contact Altera Customer Marketing at (408) 544

  3. Problem Order Implications for Learning

    ERIC Educational Resources Information Center

    Li, Nan; Cohen, William W.; Koedinger, Kenneth R.

    2013-01-01

    The order of problems presented to students is an important variable that affects learning effectiveness. Previous studies have shown that solving problems in a blocked order, in which all problems of one type are completed before the student is switched to the next problem type, results in less effective performance than does solving the problems…

  4. Introduction to Order of Operations

    NSDL National Science Digital Library

    2010-01-01

    This video demonstration introduces order of operations for pre-algebra level learners. The presenter explains the correct order of operations (parentheses, exponents, multiplication/division, addition/subtraction) using a simple math problem as an introductory example. Flash is required to view the video. Running time for the video is 9:39.

  5. Higher-order Carmichael numbers

    NASA Astrophysics Data System (ADS)

    Howe, Everett W.

    We define a Carmichael number of order m to be a composite integer n such that nth-power raising defines an endomorphism of every Z/nZ-algebra that can be generated as a Z/nZ-module by m elements. We give a simple criterion to determine whether a number is a Carmichael number of order m, and we give a heuristic argument (based on an argument of Erdos for the usual Carmichael numbers) that indicates that for every m there should be infinitely many Carmichael numbers of order m. The argument suggests a method for finding examples of higher-order Carmichael numbers; we use the method to provide examples of Carmichael numbers of order 2.

  6. Order batching in walk-and-pick order picking systems

    Microsoft Academic Search

    Y. A. Bozer; J. W. Kile

    2008-01-01

    This paper investigates the order-batching problem both as a theoretical problem, including its special variants, and as a practical problem, with possible heuristic solution procedures. It shows that certain special cases or variants of the order batching problem are solvable, while other cases of the problem are NP-hard. It also develops a new Mixed-Integer Programming (MIP) model to obtain near-exact

  7. Multiple order common path spectrometer

    NASA Technical Reports Server (NTRS)

    Newbury, Amy B. (Inventor)

    2010-01-01

    The present invention relates to a dispersive spectrometer. The spectrometer allows detection of multiple orders of light on a single focal plane array by splitting the orders spatially using a dichroic assembly. A conventional dispersion mechanism such as a defraction grating disperses the light spectrally. As a result, multiple wavelength orders can be imaged on a single focal plane array of limited spectral extent, doubling (or more) the number of spectral channels as compared to a conventional spectrometer. In addition, this is achieved in a common path device.

  8. Chimera order in spin systems

    E-print Network

    Rajeev Singh; Subinay Dasgupta; Sitabhra Sinha

    2010-11-23

    Homogeneous populations of oscillators have recently been shown to exhibit stable coexistence of coherent and incoherent regions. Generalizing the concept of chimera states to the context of order-disorder transition in systems at thermal equilibrium, we show analytically that such complex ordering can appear in a system of Ising spins, possibly the simplest physical system exhibiting this phenomenon. We also show numerically the existence of chimera ordering in 3-dimensional spin systems that model layered magnetic materials, suggesting possible means of experimentally observing such states.

  9. Complex higher order derivative theories

    SciTech Connect

    Margalli, Carlos A.; Vergara, J. David [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico 04510 DF (Mexico)

    2012-08-24

    In this work is considered a complex scalar field theory with higher order derivative terms and interactions. A procedure is developed to quantize consistently this system avoiding the presence of negative norm states. In order to achieve this goal the original real scalar high order field theory is extended to a complex space attaching a complex total derivative to the theory. Next, by imposing reality conditions the complex theory is mapped to a pair of interacting real scalar field theories without the presence of higher derivative terms.

  10. Higher-order Fibonacci numbers

    Microsoft Academic Search

    Milan Randi?; Daniel A. Morales; Oswaldo Araujo

    1996-01-01

    We consider a generalization of Fibonacci numbers that was motivated by the relationship of the HosoyaZ topological index to the Fibonacci numbers. In the case of the linear chain structures the new higher order Fibonacci numbershFn are directly related to the higher order Hosoya-typeZ numbers. We investigate the limitsFn\\/Fn-1 and the corresponding equations, the roots of which allow one to

  11. The concept of bond order

    NASA Astrophysics Data System (ADS)

    Elliott, Robert J.; Richards, W. Graham

    A method for obtaining precise charge densities in defined regions of space from ab initio molecular wavefunctions is employed to place the concept of bond order on a firm theoretical footing. The bond orders obtained for carbon—carbon bonds in a range of organic compounds are assessed: those for buta-1,3-diene confirm that it consists of essentially localised double and single bonds.

  12. John F. Kennedy Executive Orders

    NSDL National Science Digital Library

    Kennedy, John F. (John Fitzgerald), 1917-1963.

    The 214 Executive Orders signed by the 35th President have been scanned and converted to HTML by Maria E. Schieda of the University of Michigan School of Information. These include the orders to establish the Peace Corps (E.O. 10924), to establish the President's Committee on Equal Employment (E.O. 10925), and emergency instructions to government agencies during the Cuban Missile Crisis (E.O. 11051, 11058, 11087-11095). The collection is indexed by date, keyword, number, and title.

  13. Order in a multidimensional system

    PubMed Central

    Roy Frieden, B.; Gatenby, Robert A.

    2014-01-01

    We show that any convex K-dimensional system has a level of order R that is proportional to its level of Fisher information I. The proportionality constant is 1/8 the square of the longest chord connecting two surface points of the system. This result follows solely from the requirement that R decrease under small perturbations caused by a coarse graining of the system. The form for R is generally unitless, allowing the order for different phenomena, or different representations (e.g., using time vs frequency) of a given phenomenom, to be compared objectively. Order R is also invariant to uniform magnification of the system. The monotonic contraction properties of R and I define an arrow of time and imply that they are entropies, in addition to their usual status as informations. This also removes the need for data, and therefore an observer, in derivations of nonparticipatory phenomena that utilize I. Simple graphical examples of the new order measure show that it measures as well the level of “complexity” in the system. Finally, an application to cell growth during enforced distortion shows that a single hydrocarbon chain can be distorted into a membrane having equal order or complexity. Such membranes are prime constituents of living cells. PMID:21867134

  14. Using High-Order Methods on Lower-Order Geometries

    NASA Technical Reports Server (NTRS)

    Casper, Jay

    1997-01-01

    The desire to obtain acoustic information from the numerical solution of a nonlinear system of equations is a demanding proposition for a computational algorithm. High-order accuracy is required for the propagation of high-frequency, low-amplitude waves. The accuracy of an algorithm can be compromised by low-order errors that naturally occur in the solution of a particular problem. Such errors arise from two sources: the presence of discontinuities in the flow field or because the geometry on which the problem is defined is not everywhere smooth to the order of the scheme. The performance of high-order accurate essentially non-oscillatory (ENO) schemes on piecewise smooth solutions is well documented. Herein, the performance of these methods on smooth solutions defined on piecewise smooth geometries is investigated. The propagation of sound in a quasi-one-dimensional nozzle is considered as a test case. Some of the issues involved in the extension to two spatial dimensions are discussed.

  15. 77 FR 48960 - Order Renewing Order Temporarily Denying Export Privileges

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-15

    ...Airways and Zarand Aviation worked in concert, along with Kerman Aviation, to de-register...orders, Zarand Aviation has acted in concert with Mahan Airways in an effort to evade...and those related to them or acting in concert with them, such as Kerman...

  16. A Law of Order: Word Order Change in Classical Aztec

    ERIC Educational Resources Information Center

    Steele, Susan M.

    1976-01-01

    The verb in Classical Aztec is slowly moving from the end of the sentence to the beginning due to the attraction of sentence initial modal particles to the verb. Not only the function but also the position of elements should be examined to account for word-order change. (SCC)

  17. Tree reconstruction from partial orders

    SciTech Connect

    Kannan, S.K. (Arizona Univ., Tucson, AZ (United States)); Warnow, T.J. (Sandia National Labs., Albuquerque, NM (United States))

    1993-01-01

    The problem of constructing trees given a matrix of interleaf distances is motivated by applications in computational evolutionary biology and linguistics. The general problem is to find an edge-weighted tree which most closely approximates the distance matrix. Although the construction problem is easy when the tree exactly fits the distance matrix, optimization problems under all popular criteria are either known or conjectured to be NP-complete. In this paper we consider the related problem where we are given a partial order on the pairwise distances, and wish to construct (if possible) an edge-weighted tree realizing the partial order. In particular we are interested in partial orders which arise from experiments on triples of species, which determine either a linear ordering of the three pairwise distances (called Total Order Model or TOM experiments) or only the pair(s) of minimum distance apart (called Partial Order Model or POM experiments). The POM and TOM experimental model is inspired by the model proposed by Kannan, Lawler, and Warnow for constructing trees from experiments which determine the rooted topology for any triple of species. We examine issues of construction of trees and consistency of TOM and POM experiments, where the trees may either be weighted or unweighted. Using these experiments to construct unweighted trees without nodes of degree two is motivated by a similar problem studied by Winkler, called the Discrete Metric Realization problem, which he showed to be strongly NP-hard. We have the following results: Determining consistency of a set of TOM or POM experiments is NP-Complete whether the tree is weighted or constrained to be unweighted and without degree two nodes. We can construct unweighted trees without degree two nodes from TOM experiments in optimal O(n[sup 3]) time and from POM experiments in O(n[sup 4]) time.

  18. Tree reconstruction from partial orders

    SciTech Connect

    Kannan, S.K. [Arizona Univ., Tucson, AZ (United States); Warnow, T.J. [Sandia National Labs., Albuquerque, NM (United States)

    1993-03-01

    The problem of constructing trees given a matrix of interleaf distances is motivated by applications in computational evolutionary biology and linguistics. The general problem is to find an edge-weighted tree which most closely approximates the distance matrix. Although the construction problem is easy when the tree exactly fits the distance matrix, optimization problems under all popular criteria are either known or conjectured to be NP-complete. In this paper we consider the related problem where we are given a partial order on the pairwise distances, and wish to construct (if possible) an edge-weighted tree realizing the partial order. In particular we are interested in partial orders which arise from experiments on triples of species, which determine either a linear ordering of the three pairwise distances (called Total Order Model or TOM experiments) or only the pair(s) of minimum distance apart (called Partial Order Model or POM experiments). The POM and TOM experimental model is inspired by the model proposed by Kannan, Lawler, and Warnow for constructing trees from experiments which determine the rooted topology for any triple of species. We examine issues of construction of trees and consistency of TOM and POM experiments, where the trees may either be weighted or unweighted. Using these experiments to construct unweighted trees without nodes of degree two is motivated by a similar problem studied by Winkler, called the Discrete Metric Realization problem, which he showed to be strongly NP-hard. We have the following results: Determining consistency of a set of TOM or POM experiments is NP-Complete whether the tree is weighted or constrained to be unweighted and without degree two nodes. We can construct unweighted trees without degree two nodes from TOM experiments in optimal O(n{sup 3}) time and from POM experiments in O(n{sup 4}) time.

  19. Irrational charge from topological order

    E-print Network

    R. Moessner; S. L. Sondhi

    2010-04-13

    Topological or deconfined phases of matter exhibit emergent gauge fields and quasiparticles that carry a corresponding gauge charge. In systems with an intrinsic conserved U(1) charge, such as all electronic systems where the Coulombic charge plays this role, these quasiparticles are also characterized by their intrinsic charge. We show that one can take advantage of the topological order fairly generally to produce periodic Hamiltonians which endow the quasiparticles with continuously variable, generically irrational, intrinsic charges. Examples include various topologically ordered lattice models, the three dimensional RVB liquid on bipartite lattices as well as water and spin ice. By contrast, the gauge charges of the quasiparticles retain their quantized values.

  20. Magnetic Ordering in Carbon Nanotubes

    E-print Network

    Yerchuck, Dmitri; Dovlatova, Alla; Yerchak, Yauhen; Alexandrov, Andrey

    2012-01-01

    The physical origin of the mechanism of the formation of ferromagnetic ordering in carbon nanotubes (NTs) produced by high energy ion beam modification of diamond single crystals in $$ and $$ directions has been found. It is determined by asymmetry of spin density distribution of Su-Schrieffer-Heeger topological soliton lattice formed in 1D Fermi quantum liquid state of $\\pi$-electronic subsystem of given NTs. The phenomenon of formation of antiferromagnetic ordering coexisting with superconductivity at room temperature in carbon NTs, produced by high energy ion beam modification of diamond single crystals in $$ direction is discussed.

  1. 7 CFR 1220.608 - Order.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SOYBEAN PROMOTION, RESEARCH, AND CONSUMER INFORMATION Procedures... Definitions § 1220.608 Order. Order means the Soybean Promotion and Research...

  2. 7 CFR 1219.17 - Order.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE HASS AVOCADO PROMOTION, RESEARCH, AND INFORMATION Hass Avocado Promotion, Research, and Information Order Definitions § 1219.17 Order....

  3. 7 CFR 1219.17 - Order.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE HASS AVOCADO PROMOTION, RESEARCH, AND INFORMATION Hass Avocado Promotion, Research, and Information Order Definitions § 1219.17 Order....

  4. 7 CFR 1219.17 - Order.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE HASS AVOCADO PROMOTION, RESEARCH, AND INFORMATION Hass Avocado Promotion, Research, and Information Order Definitions § 1219.17 Order....

  5. Octupolar order in two dimensions

    E-print Network

    Epifanio G. Virga

    2015-03-16

    Octupolar order is described in two space dimensions in terms of the maxima (and conjugated minima) of the probability density associated with a third-rank, fully symmetric and traceless tensor. Such a representation is shown to be equivalent to diagonalizing the relevant third-rank tensor, an equivalence which however is only valid in the two-dimensional case.

  6. Executive Order 1083 Attachment C

    E-print Network

    Eirinaki, Magdalini

    ) An administrative officer or supervisor of child welfare and attendance, or a certificated pupil personnel employee, or local child support agency caseworker, unless the investigator, inspector, or caseworker is workingExecutive Order 1083 Attachment C California Child Abuse and Neglect Reporting Act Penal Code

  7. PBVE Calls for Orderly Transition

    ERIC Educational Resources Information Center

    West, B. R.

    1976-01-01

    In this article, one of five concerning trends in vocational education, performance-based vocational education (PBVE) is viewed as the wave of the near future, permeating every aspect of the program. The author notes that in an orderly transition, personnel development should take the lead to produce change agents as well as the practioners who…

  8. Order computations in generic groups

    E-print Network

    Sutherland, Andrew V

    2007-01-01

    We consider the problem of computing the order of an element in a generic group. The two standard algorithms, Pollard's rho method and Shanks' baby-steps giant-steps technique, both use [theta](N^1/2) group operations to ...

  9. Birth order and intellectual development

    Microsoft Academic Search

    R. B. Zajonc; Gregory B. Markus

    1975-01-01

    Describes a confluence model that explains the effects of birth order and family size on intelligence. Intellectual development within the family context is conceived of as depending on the cumulative effects of the intellectual environment, which consists primarily of the siblings' and parents' intelligence. Mutual influences, through time, on the intellectual development of the siblings are described by the growth

  10. PEMDAS: Algebraic Order of Operations

    NSDL National Science Digital Library

    2009-03-15

    Watch this music video to help you learn about PEMDAS (Please Excuse My Dear Aunt Sally). Does this sound familiar? If not, this is an excellent device to memorize the algebraic order of operations. This video is produced by Mr. Davis Productions and plays music by Odyssey Sound Lab.

  11. Destabilizing the American Racial Order

    Microsoft Academic Search

    Jennifer L. Hochschild; Vesla M. Weaver; Traci Burch

    2011-01-01

    Are racial disparities in the United States just as deep-rooted as they were before the 2008 presidential election, largely eliminated, or persistent but on the decline? One can easily find all of these pronouncements; rather than trying to adjudicate among them, this essay seeks to identify what is changing in the American racial order, what persists or is becoming even

  12. JOB ORDER CONTRACT Technical Specifications

    E-print Network

    Gelfond, Michael

    JOB ORDER CONTRACT Technical Specifications BOOK 1 OF 5 CSI SECTIONS 01 - 07 January 2013 TM Texas Tech University TOC - 1 01 General Requirements 01 22 16 00 No Specification Required 01 32 33 00 00 Architecturally Exposed Structural Steel Framing 01 95 23 00a HVAC Instrumentation And Controls 01

  13. Weighted order statistic classifiers with large rank-order margin.

    SciTech Connect

    Porter, R. B. (Reid B.); Hush, D. R. (Donald R.); Theiler, J. P. (James P.); Gokhale, M. (Maya)

    2003-01-01

    We describe how Stack Filters and Weighted Order Statistic function classes can be used for classification problems. This leads to a new design criteria for linear classifiers when inputs are binary-valued and weights are positive . We present a rank-based measure of margin that can be directly optimized as a standard linear program and investigate its effect on generalization error with experiment. Our approach can robustly combine large numbers of base hypothesis and easily implement known priors through regularization.

  14. Low Order Discontinuous Galerkin Methods for Second Order Elliptic Problems

    Microsoft Academic Search

    Erik Burman; Benjamin Stamm

    2008-01-01

    Abstract. We consider DG-methods for 2nd order scalar elliptic problems using piecewise affine approximation,in two or three space dimensions. We prove that both the symmetric,and the non- symmetric,version of the DG-method are well-posed also without penalization of the interelement solution jumps provided boundary,conditions are imposed weakly. Optimal convergence is proved for sufficiently regular meshes and data. We then propose a

  15. The Copyright (International Conventions) (Amendment) Order 1986 

    E-print Network

    Her Majesty's Stationary Office

    1986-01-01

    This Order corrects an error In the Copyright (International Conventions) (Amendment) Order 1984, which amended the Copyright (International Conventions) Order 1979. The 1984 Order applied the Copyright Act 1956 to copyright ...

  16. Orientational ordering of charged colloids

    NASA Astrophysics Data System (ADS)

    Eggen, E. J.

    2010-02-01

    This thesis studies orientational ordering of charged colloidal particles, which appears if the particles are not spherically symmetric. Generally, this is the case. The nonspherical aspects of colloidal particles can be either due to shape or to chemical surface properties. The question we address is: when do such nonspherical properties become important in the collective behavior of colloidal particles? To answer this question, we theoretically investigate the equilibrium properties of charged colloidal particles. We have chosen charge particles for three reasons. First, electrostatic effects are generally present in colloidal suspensions. Second, there were, and still are, many opportunities in this field to answer existing questions or raise new ones. Third, the effective interactions between charged colloidal particles are relatively easy to describe. In the end, we hope to describe collective properties that can be obtained through the equilibration of a system. The way we treat particle orientations is through orientational distributions. Analogous to particle-position distributions, we find configurations that minimize the free energy, thereby predicting the equilibrium state. We distinguish four types of phases that describe equilibrium configurations: isotropic fluid, liquid crystal, plastic crystal, and aligned crystal. The isotropic-fluid phase is characterized by a lack of both positional and orientational ordering. Fluids that display orientational ordering but no (complete) positional ordering are denoted liquid crystals. Conversely, in the case of a plastic crystal there is complete positional ordering but no orientational ordering. The aligned-crystal phase exhibits both orientational and positional ordering. We view particles of different orientation as particles belonging to different species. Such a description is easily implemented in a grand-canonical ensemble to find the most favorable distribution of particle orientations in a system. In this thesis, we apply the description to systems of colloidal particles that are either rodlike in shape and homogeneously charged, or heterogeneously charged and spherical. In chapter 2, we treat the phase behavior of short charged rods. We construct a mapping onto systems of hard rods with effective dimensions. The liquid-crystal phases that are predicted in these systems are no longer present for rods of sufficiently high charge, because their interactions are essentially isotropic. Chapter 3 is based on a charge renormalization scheme, which defines a relation between the nonlinear and linearized descriptions of electrostatic interactions between charged colloidal particles. This scheme is traditionally applied to spherical particles with homogeneous surface charge, but we apply it to colloidal spheres of heterogeneous surface charge. Finally, we present two models in which we apply bifurcation theory to a linearized description for heterogeneously charged spheres. In chapter 4 we introduce a cell model, which we employ in chapter 5 to describe fluid phases, as it lacks any positional ordering of the colloidal particles. The second model is treated in chapter 6 and puts the particles on a fixed lattice, which characterizes the positional ordering in solids. In both cases we investigate the possibility of an isotropic-to-aligned transition of the orientational distribution. In the fluid phase we find none, whereas the solid phase exhibits two possible transitions.

  17. Correlation of electric polarization and magnetic ordering in cobalt chloride thiourea

    NASA Astrophysics Data System (ADS)

    Mun, Eundeok; Wilcox, Jason; Manson, Jamie; Scott, Brian; Tobash, Paul; Bauer, Eric; Zapf, Vivien

    2011-03-01

    The coupling between electricity and magnetism in magneto-electric multiferroics has been intensively investigated in a wide range of transition metal oxides. Recently the material classes have been extended to organo-metallic insulators (sometimes known as metal-organic frameworks or molecular magnets) such as NiCl2-4[SC(NH2)2], which provides a new arena for designing magneto-electric multiferroics. We have grown single crystals of cobalt chloride thiourea, CoCl2-n[SC(NH2)2], which forms two different crystal structures with n = 2 and 4. The compound CoCl2-2[SC(NH2)2] has a triclinic crystal structure with strong magnetic anisotropy and ˜ 3 ?B/Co ion, indicating S = 3/2 Co spins, and the compound CoCl2-4[SC(NH2)2] has a tetragonal structure with almost no magnetic anisotropy and 1 ?B/Co ion, indicating S = 1/2 Co spins. We will present details of the magnetic field-induced electric polarizations and magnetic properties of these compounds.

  18. Perturbative gadgets at arbitrary orders

    NASA Astrophysics Data System (ADS)

    Jordan, Stephen P.; Farhi, Edward

    2008-06-01

    Adiabatic quantum algorithms are often most easily formulated using many-body interactions. However, experimentally available interactions are generally two-body. In 2004, Kempe, Kitaev, and Regev introduced perturbative gadgets, by which arbitrary three-body effective interactions can be obtained using Hamiltonians consisting only of two-body interactions. These three-body effective interactions arise from the third order in perturbation theory. Since their introduction, perturbative gadgets have become a standard tool in the theory of quantum computation. Here we construct generalized gadgets so that one can directly obtain arbitrary k -body effective interactions from two-body Hamiltonians. These effective interactions arise from the k th order in perturbation theory.

  19. Order stars and stability theorems

    Microsoft Academic Search

    G. Wanner; E. Hairer; S. P. Nørsett

    1978-01-01

    This paper clears up to the following three conjectures:1.The conjecture of Ehle [1] on theA-acceptability of Padé approximations toez, which is true;2.The conjecture of Nørsett [5] on the zeros of the “E-polynomial”, which is false;3.The conjecture of Daniel and Moore [2] on the highest attainable order of certainA-stable multistep methods, which is true, generalizing the well-known Theorem of Dahlquist.

  20. Torn Shirts Inc: Telephone Orders

    NSDL National Science Digital Library

    High School Operations Research

    1996-01-01

    A challenging but well-guided activity, Torn Shirts has students analyze data to reach a decision on a business question. They first determine the probability that a customer calling to order a shirt gets a busy signal, then estimate the amount of money the company might lose when customers get a busy signal. Work with graphs and averages, especially the median, helps students reach a conclusion.

  1. Linear Functions of Order Statistics

    Microsoft Academic Search

    Stephen Mack Stigler

    1969-01-01

    The purpose of this paper is to investigate the asymptotic normality of linear combinations of order statistics; that is, to find conditions under which a statistic of the form $S_n = \\\\mathbf{\\\\sum}^n_{i=1} c_{in}X_{in}$ has a limiting normal distribution as $n$ becomes infinite, where the $c_{in}$'s are constants and $X_{1n}, X_{2n}, \\\\cdots, X_{nn}$ are the observations of a sample of size

  2. International nuclear order: a rejoinder

    Microsoft Academic Search

    WILLIAM WALKER

    2007-01-01

    The article‘Nuclear enlightenment and counter-enlightenment by William Walker opened the special issue of International Affairs which was published in May 2007. In it, he claimed that the United States departed in the late 1990s and early 2000s, at the height of its hegemonic influence, from a conception of international nuclear order that it had held to, with few interruptions, over

  3. Phylogenetic List of Insect Orders

    NSDL National Science Digital Library

    0000-00-00

    from editor: this table doesn't have any link back to the webpage it is linked to, which puts the reader at a dead end and doesn't give the context of the parent site. They should just submit the parent webpage instead of the lists of terms and Orders separately. I already approved the .pdf list of terms, but we should consider just posting the parent site instead: http://entnemdept.ifas.ufl.edu/choate/insecpdf.htm.

  4. Second-order Darboux displacements

    NASA Astrophysics Data System (ADS)

    Samsonov, B. F.; Glasser, M. L.; Negro, J.; Nieto, L. M.

    2003-10-01

    The potentials for a one-dimensional Schrödinger equation that are displaced along the x-axis under second-order Darboux transformations, called 2-SUSY invariant, are characterized in terms of a differential-difference equation. The solutions of the Schrödinger equation with such potentials are given analytically for any value of the energy. The method is illustrated by a two-soliton potential. It is proved that a particular case of the periodic Lamé-Ince potential is 2-SUSY invariant. Both Bloch solutions of the corresponding Schrödinger equation are found for any value of the energy. A simple analytic expression for a family of two-gap potentials is derived.

  5. 8.EE Orders of Magnitude

    NSDL National Science Digital Library

    2013-09-06

    This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: It is said that the average person blinks about 1000 times an hour. This is an order-of-magnitude estimate, that is, it is an estimate given as a power...

  6. Multiferroicity due to Charge Ordering

    NASA Astrophysics Data System (ADS)

    van den Brink, Jeroen

    2012-02-01

    In this contribution I discuss multiferroicity that is driven by different forms of charge ordering, presenting first the generic mechanisms by which charge ordering can induce ferroelectricity in magnetic systems. In type-I multiferroics [1], ferroelectricity and magnetism have different origins and occur at different temperatures. There is a number of specific classes of materials for which this is relevant. Discussed will be in some detail (i) perovskite manganites of the type (PrCa)MnO3 [2,3], (ii) the complex and interesting situation in magnetite Fe3O4, (iii) strongly ferroelectric frustrated LuFe2O4 and (iv) an example of a quasi-one-dimensional organic system [4]. In type-II multiferroics [1], ferroelectricity is completely due to magnetism, but with charge ordering playing an important role [5], such as (v) multiferroic Ca3CoMnO6, (vi) possible ferroelectricity in rare earth perovskite nickelates of the type RNiO3 [6,7], (vii) multiferroic properties of manganites of the type RMn2O5 [8], (viii) perovskite manganites with magnetic E-type ordering. [4pt] [1] J. van den Brink and D. Khomskii, J. Phys.: Condens. Matter 20, 434217 (2008).[0pt] [2] D.V. Efremov, J. van den Brink and D.I. Khomskii, Nature Materials 3, 853 (2004).[0pt] [3] G. Giovannetti, S. Kumar, J. van den Brink, S. Picozzi, Phys. Rev. Lett. 103, 037601 (2009).[0pt] [4] G. Giovannetti, S. Kumar, A. Stroppa, J. van den Brink and S. Picozzi, Phys. Rev. Lett. 103, 266401 (2009). [0pt] [5] J. Betouras G. Giovannetti and J. van den Brink, Phys. Rev. Lett. 98, 257602 (2007).[0pt] [6] G. Giovannetti, S. Kumar, D. Khomskii, S. Picozzi and J. van den Brink, Phys. Rev. Lett. 103, 156401 (2009).[0pt] [7] S. Kumar, G. Giovannetti, J. van den Brink and S. Picozzi, Phys. Rev. B 82, 134429 (2010).[0pt] [8] G. Giovannetti and J. van den Brink, Phys. Rev. Lett. 100, 227603 (2008).

  7. 19 CFR 210.75 - Proceedings to enforce exclusion orders, cease and desist orders, consent orders, and other...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...desist orders, consent orders, and other Commission orders. 210.75 Section 210.75...Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT...

  8. The Fitness of Genomic Order

    NASA Astrophysics Data System (ADS)

    Zhang, Qiucen; Vyawahare, Saurabh; Austin, Robert

    2012-02-01

    Most bacteria have a single circular chromosome that can range in size from 160,000 to 12,200,000 base pairs. Considering the typical gene density, i.e. 1 gene per 1,000 base pairs, both the number of genes and the ways to arrange are huge. Intuitively, the arrangement of genes on the circle is not important if all of them can be replicated. However, there is typically one origin of replication, and when bacteria is attacked by genotoxic stress during replication, the whole replication process can not be finished. As a result, which gene is replicated first, which is second, ..., becomes very important. Experimentally, we found a broad increase of DNA copy number near the origin of replication (OriC) of bacteria E.coli (˜3200 genes) under genotoxic stress. Since the genes near OriC are mostly efflux pump genes, we propose that there is fitness advantage for those rapid stress response genes got replicated first, because they can facilitate the replication of the rest of genome. Similar to bacterial evolution to present genomic order, in the somatic evolution of cancer, genomic shuffling was also frequently observed, especially under genotoxic chemotherapy. Such re-arrangement of genome can be viewed as a journey to optimal point in the rugged fitness landscape of genomic order.

  9. Biocatalytic induction of supramolecular order

    NASA Astrophysics Data System (ADS)

    Hirst, Andrew R.; Roy, Sangita; Arora, Meenakshi; Das, Apurba K.; Hodson, Nigel; Murray, Paul; Marshall, Stephen; Javid, Nadeem; Sefcik, Jan; Boekhoven, Job; van Esch, Jan H.; Santabarbara, Stefano; Hunt, Neil T.; Ulijn, Rein V.

    2010-12-01

    Supramolecular gels, which demonstrate tunable functionalities, have attracted much interest in a range of areas, including healthcare, environmental protection and energy-related technologies. Preparing these materials in a reliable manner is challenging, with an increased level of kinetic defects observed at higher self-assembly rates. Here, by combining biocatalysis and molecular self-assembly, we have shown the ability to more quickly access higher-ordered structures. By simply increasing enzyme concentration, supramolecular order expressed at molecular, nano- and micro-levels is dramatically enhanced, and, importantly, the gelator concentrations remain identical. Amphiphile molecules were prepared by attaching an aromatic moiety to a dipeptide backbone capped with a methyl ester. Their self-assembly was induced by an enzyme that hydrolysed the ester. Different enzyme concentrations altered the catalytic activity and size of the enzyme clusters, affecting their mobility. This allowed structurally diverse materials that represent local minima in the free energy landscape to be accessed based on a single gelator structure.

  10. Well-partial orders, equivariant Grobner Bases,

    E-print Network

    California at Berkeley, University of

    Well-partial orders, equivariant Gr¨obner Bases, and applications Jan Draisma TU Eindhoven Berkeley, RTG workshop, September 2012 #12;Well-partial orders Definition on S is well-partial-order if s0, s1, s2, . . . S i Well-partial orders Definition on S is well-partial-order if s0, s

  11. A concept of generalized order statistics

    Microsoft Academic Search

    Udo Kamps

    1995-01-01

    A form of the joint distribution of n ordered random variables is presented that enables a unified approach to a variety of models of ordered random variables, e.g. order statistics and record values. Several other models are shown. In particular, sequential order statistics are introduced as a modification of order statistics which is naturally suggested by a statistical application in

  12. Ordering Phenomena in Undercooled Alloys

    SciTech Connect

    Fultz, Brent

    1997-07-17

    Much of the work performed under this grant was devoted to using modern ideas in kinetics to understand atom movements in metallic alloys far from thermodynamic equilibrium. Kinetics arguments were based explicitly on the vacancy mechanism for atom movements. The emphasis was on how individual atom movements are influenced by the local chemical environment of the moving atom, and how atom movements cause changes in the local chemical environments. The author formulated a kinetic master equation method to treat atom movements on a crystal lattice with a vacancy mechanism. Some of these analyses [3,10,16] are as detailed as any treatment of the statistical kinetics of atom movements in crystalline alloys. Three results came from this work. Chronologically they were (1) A recognition that tracking time dependencies is not necessarily the best way to study kinetic phenomena. If multiple order parameters can be measured in a material, the ''kinetic path'' through the space spanned by these order parameters maybe just as informative about the chemical factors that affect atom movements [2,3,5-7,9-11,14-16,18,19,21,23,24,26,36,37]. (2) Kinetic paths need not follow the steepest gradient of the free energy function (this should be well-known), and for alloys far from equilibrium the free energy function can be almost useless in describing kinetic behavior. This is why the third result surprised me. (3) In cluster approximations with multiple order parameters, saddle points are common features of free energy functions. Interestingly, kinetic processes stall or change time scale when the kinetic path approaches a state at a saddle point in the free energy function, even though these states exist far from thermodynamic equilibrium. The author calls such a state a ''pseudostable'' (falsely stable) state [6,21,26]. I have also studied these phenomena by more ''exact'' Monte Carlo simulations. The kinetic paths showed features similar to those found in analytical theories. The author found that a microstructure with interfaces arranged in space as a periodic minimal surface is a probably an alloy at a saddle point in its free energy function [21,26,37].

  13. Recent advances in ordered intermetallics

    SciTech Connect

    Liu, C.T.

    1992-12-31

    This paper briefly summarizes recent advances in intermetallic research and development. Ordered intermetallics based on aluminides and silicides possess attractive properties for structural applications at elevated temperatures in hostile environments; however, brittle fracture and poor fracture resistance limit their use as engineering materials in many cases. In recent years, considerable efforts have been devoted to the study of the brittle fracture behavior of intermetallic alloys; as a result, both intrinsic and extrinsic factors governing brittle fracture have been identified. Recent advances in first-principles calculations and atomistic simulations further help us in understanding atomic bonding, dislocation configuration, and alloying effects in intermetallics. The basic understanding has led to the development of nickel, iron, and titanium aluminide alloys with improved mechanical and metallurgical properties for structural use. Industrial interest in ductile intermetallic alloys is high, and several examples of industrial involvement are mentioned.

  14. Ordered structures and jet noise

    NASA Technical Reports Server (NTRS)

    Petersen, R. A.; Kaplan, R. E.; Laufer, J.

    1974-01-01

    A series of measurements of near field pressures and turbulent velocity fluctuations were made in a jet having a Reynolds number of about 50,000 in order to investigate more quantitatively the character and behavior of the large scale structures, and to ascertain their importance to the jet noise problem. It was found that the process of interaction between vortices can be inhibited by artificially exciting the shear layers with periodic disturbances of certain frequency. The turbulent fluctuation amplitudes measured at four diameters downstream decreased considerably. Finally, it was observed that the passage frequency of the structures decreased with x in a similar manner as the frequency corresponding to the maximum intensity radiation emanating from the same value of x.

  15. Dependency Ordering of Atomic Observables

    NASA Astrophysics Data System (ADS)

    C?rulis, J?nis

    2015-01-01

    The notion of atomic observable was introduced by S.Gudder for effect test spaces in 1997. In this paper an observable is a ?-homomorphism from the Borel algebra on a line to some logic. Roughly, an observable on a logic is atomic, if it is completely determined by its restriction to one-element subsets of its point spectrum. In particular, every discrete observable is atomic. We study some elementary properties of such observables, and discuss a possible notion of functional dependency between them. Algebraically, a dependency is a certain preorder relation on the set of all atomic observables, which induces an order relation on the set of all maximal orthogonal subsets of the logic. Several properties, as well as characteristics in terms of the underlying logic, of these relations are stated.

  16. Quantum quenches and competing orders

    NASA Astrophysics Data System (ADS)

    Fu, Wenbo; Hung, Ling-Yan; Sachdev, Subir

    2014-07-01

    We study the nonequilibrium dynamics of an electronic model of competition between an unconventional charge density wave (a bond density wave) and d-wave superconductivity. In a time-dependent Hartree-Fock+BCS approximation, the dynamics reduces to the equations of motion of operators realizing the generators of SU(4) at each pair of momenta, (k,-k), in the Brillouin zone. We also study the nonequilibrium dynamics of a quantum generalization of a O(6) nonlinear ? model of competing orders in the underdoped cuprates [Hayward et al., Science 343, 1336 (2014), 10.1126/science.1246310]. We obtain results, in the large N limit of a O(N) model, on the time dependence of correlation functions following a pulse disturbance. We compare our numerical studies with recent picosecond optical experiments. We find that, generically, the oscillatory responses in our models share various qualitative features with the experiments.

  17. Frustrated order on extrinsic geometries

    E-print Network

    Badel L. Mbanga; Gregory M. Grason; Christian D. Santangelo

    2011-08-07

    We study, analytically and theoretically, defects in a nematically-ordered surface that couple to the extrinsic geometry of a surface. Though the intrinsic geometry tends to confine topological defects to regions of large Gaussian curvature, extrinsic couplings tend to orient the nematic in the local direction of maximum or minimum bending. This additional frustration is unavoidable and most important on surfaces of negative Gaussian curvature, where it leads to a complex ground state thermodynamics. We show, in contradistinction to the well-known effects of intrinsic geometry, that extrinsic curvature expels disclinations from the region of maximum curvature above a critical coupling threshold. On catenoids lacking an "inside-outside" symmetry, defects are expelled altogether.

  18. Deriving Laws from Ordering Relations

    NASA Technical Reports Server (NTRS)

    Knuth, Kevin H.

    2003-01-01

    It took much effort in the early days of non-Euclidean geometry to break away from the mindset that all spaces are flat and that two distinct parallel lines do not cross. Up to that point, all that was known was Euclidean geometry, and it was difficult to imagine anything else. We have suffered a similar handicap brought on by the enormous relevance of Boolean algebra to the problems of our age-logic and set theory. Previously, I demonstrated that the algebra of questions is not Boolean, but rather is described by the free distributive algebra. To get to this stage took much effort, as many obstacles-most self-placed-had to be overcome. As Boolean algebras were all I had ever known, it was almost impossible for me to imagine working with an algebra where elements do not have complements. With this realization, it became very clear that the sum and product rules of probability theory at the most basic level had absolutely nothing to do with the Boolean algebra of logical statements. Instead, a measure of degree of inclusion can be invented for many different partially ordered sets, and the sum and product rules fall out of the associativity and distributivity of the algebra. To reinforce this very important idea, this paper will go over how these constructions are made, while focusing on the underlying assumptions. I will derive the sum and product rules for a distributive lattice in general and demonstrate how this leads to probability theory on the Boolean lattice and is related to the calculus of quantum mechanical amplitudes on the partially ordered set of experimental setups. I will also discuss the rules that can be derived from modular lattices and their relevance to the cross-ratio of projective geometry.

  19. 10 CFR 820.23 - Consent order.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Consent order. 820.23 Section 820.23...ACTIVITIES Enforcement Process § 820.23 Consent order. (a) Settlement policy. ...there shall be no transcript. (b) Consent order. Notwithstanding any...

  20. 10 CFR 820.23 - Consent order.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Consent order. 820.23 Section 820.23...ACTIVITIES Enforcement Process § 820.23 Consent order. (a) Settlement policy. ...there shall be no transcript. (b) Consent order. Notwithstanding any...

  1. 10 CFR 820.23 - Consent order.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Consent order. 820.23 Section 820.23...ACTIVITIES Enforcement Process § 820.23 Consent order. (a) Settlement policy. ...there shall be no transcript. (b) Consent order. Notwithstanding any...

  2. 10 CFR 820.23 - Consent order.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Consent order. 820.23 Section 820.23...ACTIVITIES Enforcement Process § 820.23 Consent order. (a) Settlement policy. ...there shall be no transcript. (b) Consent order. Notwithstanding any...

  3. 10 CFR 820.23 - Consent order.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Consent order. 820.23 Section 820.23...ACTIVITIES Enforcement Process § 820.23 Consent order. (a) Settlement policy. ...there shall be no transcript. (b) Consent order. Notwithstanding any...

  4. 1 CFR 8.2 - Orderly development.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Orderly development. 8.2 Section 8.2 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER SPECIAL EDITIONS OF THE FEDERAL REGISTER CODE OF FEDERAL REGULATIONS § 8.2 Orderly development. To assure orderly development...

  5. Linearisable Third Order Ordinary Differential Equations

    E-print Network

    Wolf, Thomas

    words and phrases: Nonlinear ordinary differential equations, Linearisation, Invertible Transformations Linearisable Third Order Ordinary Differential Equations and M. Euler, Linearisable Third Order Ordinary Differential Equations and Generalised Sundman

  6. Deriving Laws from Ordering Relations

    NASA Technical Reports Server (NTRS)

    Knuth, Kevin H.

    2004-01-01

    The effect of Richard T. Cox's contribution to probability theory was to generalize Boolean implication among logical statements to degrees of implication, which are manipulated using rules derived from consistency with Boolean algebra. These rules are known as the sum rule, the product rule and Bayes Theorem, and the measure resulting from this generalization is probability. In this paper, I will describe how Cox s technique can be further generalized to include other algebras and hence other problems in science and mathematics. The result is a methodology that can be used to generalize an algebra to a calculus by relying on consistency with order theory to derive the laws of the calculus. My goals are to clear up the mysteries as to why the same basic structure found in probability theory appears in other contexts, to better understand the foundations of probability theory, and to extend these ideas to other areas by developing new mathematics and new physics. The relevance of this methodology will be demonstrated using examples from probability theory, number theory, geometry, information theory, and quantum mechanics.

  7. Boundary Degeneracy of Topological Order

    E-print Network

    Juven Wang; Xiao-Gang Wen

    2015-01-15

    We introduce the concept of boundary degeneracy of topologically ordered states on a compact orientable spatial manifold with boundaries, and emphasize that the boundary degeneracy provides richer information than the bulk degeneracy. Beyond the bulk-edge correspondence, we find the ground state degeneracy of the fully gapped edge modes depends on boundary gapping conditions. By associating different types of boundary gapping conditions as different ways of particle or quasiparticle condensations on the boundary, we develop an analytic theory of gapped boundaries. By Chern-Simons theory, this allows us to derive the ground state degeneracy formula in terms of boundary gapping conditions, which encodes more than the fusion algebra of fractionalized quasiparticles. We apply our theory to Kitaev's toric code and Levin-Wen string-net models. We predict that the $Z_2$ toric code and $Z_2$ double-semion model (more generally, the $Z_k$ gauge theory and the $U(1)_k \\times U(1)_{-k}$ non-chiral fractional quantum Hall state at even integer $k$) can be numerically and experimentally distinguished, by measuring their boundary degeneracy on an annulus or a cylinder.

  8. Boundary degeneracy of topological order

    NASA Astrophysics Data System (ADS)

    Wang, Juven C.; Wen, Xiao-Gang

    2015-03-01

    We introduce the concept of boundary degeneracy, as the ground state degeneracy of topologically ordered states on a compact orientable spatial manifold with gapped boundaries. We emphasize that the boundary degeneracy provides richer information than the bulk degeneracy. Beyond the bulk-edge correspondence, we find the ground state degeneracy of the fully gapped edge modes depends on boundary gapping conditions. By associating different types of boundary gapping conditions as different ways of particle or quasiparticle condensations on the boundary, we develop an analytic theory of gapped boundaries. By Chern-Simons theory, this allows us to derive the ground state degeneracy formula in terms of boundary gapping conditions, which encodes more than the fusion algebra of fractionalized quasiparticles. We apply our theory to Kitaev's toric code and Levin-Wen string-net models. We predict that the Z2 toric code and Z2 double-semion model [more generally, the Zk gauge theory and the U (1) k×U (1) -k nonchiral fractional quantum Hall state at even integer k ] can be numerically and experimentally distinguished, by measuring their boundary degeneracy on an annulus or a cylinder.

  9. Order, chaos and nuclear dynamics

    NASA Astrophysics Data System (ADS)

    Blocki, J.; Shi, J.-J.; Swiatecki, W. J.

    1993-03-01

    The relation between the order-to-chaos transition in the dynamics of independent classical particles in a container, and the transition from an elastic to a dissipative response of the container to shape changes, is studied by means of computer simulations. The validity of the wall formula for energy dissipation is confirmed in the case of containers whose surfaces are rippled according to Legendre polynomials P3, P4, P5, P6, in which case the particle trajectories are largely chaotic, as revealed by Poincaré sections in phase space. The opposite limit of an elastic response is illustrated by means of spheroidal containers of various eccentricities, for which the particle trajectories are integrable and the phase space is foliated by tori. Fission-like deformations are also considered, for which the response of the container changes from elastic to dissipative with increasing deformation. Idealized giant-dipole oscillations of the gas are studied for spherical as well as deformed containers. A generalization of the wall formula valid for long times (i.e., for arbitrarily large excitations of the gas) is constructed. The principal lesson of these studies is that a gas of independent particles in a time-dependent container does not behave at all like a gas.

  10. Dislocation sources in ordered intermetallics

    SciTech Connect

    Yoo, M.H. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.; Appel, F.; Wagner, R. [GKSS-Research Centre, Geesthacht (Germany). Inst. for Materials Research; Mecking, H. [Technical Univ. Hamburg-Harburg, Hamburg (Germany)

    1996-09-01

    An overview on the current understanding of dislocation sources and multiplication mechanisms is made for ordered intermetallic alloys of the L1{sub 2}, B2, and D0{sub 19} structures. In L1{sub 2} alloys, a large disparity of edge/screw segments in their relative mobility reduces the efficiency of a Frank-Read Type multiplication mechanism. In Fe-40%Al of the B2 structure, a variety of dislocation sources are available for <111> slip, including ones resulting from condensation of thermal vacancies. In NiAl with the relatively high APB energy, <100> dislocations may result from the dislocation decomposition reactions, the prismatic punching out from inclusion particles, and/or steps and coated layers of the surface. Internal interfaces often provide sites for dislocation multiplication, e.g., grain boundaries, sub-boundaries in Ni{sub 3}Ga, NiAl and Ti{sub 3}Al, and antiphase domain boundaries in Ti{sub 3}Al. As for the crack tip as a dislocation source, extended SISFs trailed by super-Shockley partials emanating form the cracks in Ni{sub 3}Al and Co{sub 3}Ti are discussed in view of a possible toughening mechanism.

  11. Liquid crystalline order in mucus

    NASA Technical Reports Server (NTRS)

    Viney, C.; Huber, A. E.; Verdugo, P.

    1993-01-01

    Mucus plays an exceptionally wide range of important biological roles. It operates as a protective, exchange, and transport medium in the digestive, respiratory, and reproductive systems of humans and other vertebrates. Mucus is a polymer hydrogel. It is secreted as discrete packages (secretory granules) by specialized secretory cells. Mucus hydrogel is stored in a condensed state inside the secretory granules. Depending upon the architecture of their constituent macromolecules and on the composition of the solvent, polymer gels can form liquid crystalline microstructures, with orientational order being exhibited over optically resolvable distances. Individual mucin molecules consist of alternating rigid segments (heavily glycosylated; hydrophilic) and flexible segments (nonglycosylated; hydrophobic). Polymer molecules consisting of rigid units linked by flexible spacers are frequently associated with liquid crystalline behavior, which again raises the possibility that mucus could form anisotropic fluid phases. Suggestions that mucins may be self-associating in dilute solution have previously been challenged on the basis of sedimentation-equilibrium studies performed on mucus in which potential sites of association were competitively blocked with inhibitors. However, the formation of stable liquid crystalline phases does not depend on the existence of inter- or intramolecular associations; these phases can form on the basis of steric considerations alone.

  12. Fourth order spatial derivative gravity

    SciTech Connect

    Bemfica, F. S.; Gomes, M. [Instituto de Fisica, Universidade de Sao Paulo Caixa Postal 66318, 05315-970, Sao Paulo, SP (Brazil)

    2011-10-15

    In this work, we study a modified theory of gravity that contains up to fourth order spatial derivatives as a model for the Horava-Lifshitz gravity. The propagator is evaluated and, as a result, one extra pole is obtained, corresponding to a spin-2 nonrelativistic massless particle, an extra term which jeopardizes renormalizability, besides the unexpected general relativity unmodified propagator. Then unitarity is proved at the tree level, where the general relativity pole has been shown to have no dynamics, remaining only the 2 degrees of freedom of the new pole. Next, the nonrelativistic effective potential is determined from a scattering process of two identical massive gravitationally interacting bosons. In this limit, Newton's potential is obtained, together with a Darwin-like term that comes from the extra nonpole term in the propagator. Regarding renormalizability, this extra term may be harmful by power counting, but it can be eliminated by adjusting the free parameters of the model. This adjustment is in accord with the detailed balance condition suggested in the literature and shows that the way in which extra spatial derivative terms are added is of fundamental importance.

  13. 14 CFR 16.243 - Consent orders.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Consent orders. 16.243 Section 16.243...Decisions, Orders and Appeals § 16.243 Consent orders. (a) The agency attorney...to dispose of the case by issuance of a consent order. Good faith efforts to...

  14. 14 CFR 16.243 - Consent orders.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Consent orders. 16.243 Section 16.243...Decisions, Orders and Appeals § 16.243 Consent orders. (a) The agency attorney...to dispose of the case by issuance of a consent order. Good faith efforts to...

  15. 14 CFR 16.243 - Consent orders.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Consent orders. 16.243 Section 16.243...Decisions, Orders and Appeals § 16.243 Consent orders. (a) The agency attorney...to dispose of the case by issuance of a consent order. Good faith efforts to...

  16. 14 CFR 16.243 - Consent orders.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Consent orders. 16.243 Section 16.243...Decisions, Orders and Appeals § 16.243 Consent orders. (a) The agency attorney...to dispose of the case by issuance of a consent order. Good faith efforts to...

  17. Free Triangle Orders Joshua D. Laison

    E-print Network

    Laison, Josh

    Free Triangle Orders Joshua D. Laison Department of Mathematics Colorado College 14 E. Cache La triangle orders. These are ordered sets represented by a left-to-right ordering on geometric objects con- tained in a horizontal strip in the plane. The objects are called "free triangles," and have one vertex

  18. Generalized structure of higher order nonclassicality

    E-print Network

    Amit Verma; Anirban Pathak

    2009-01-21

    A generalized notion of higher order nonclassicality (in terms of higher order moments) is introduced. Under this generalized framework of higher order nonclassicality, conditions of higher order squeezing and higher order subpoissonian photon statistics are derived. A simpler form of the Hong-Mandel higher order squeezing criterion is derived under this framework by using an operator ordering theorem introduced by us in [J. Phys. A. 33 (2000) 5607]. It is also generalized for multi-photon Bose operators of Brandt and Greenberg. Similarly, condition for higher order subpoissonian photon statistics is derived by normal ordering of higher powers of number operator. Further, with the help of simple density matrices, it is shown that the higher order antibunching (HOA) and higher order subpoissonian photon statistics (HOSPS) are not the manifestation of the same phenomenon and consequently it is incorrect to use the condition of HOA as a test of HOSPS. It is also shown that the HOA and HOSPS may exist even in absence of the corresponding lower order phenomenon. Binomial state, nonlinear first order excited squeezed state (NLESS) and nonlinear vacuum squeezed state (NLVSS) are used as examples of quantum state and it is shown that these states may show higher order nonclssical characteristics. It is observed that the Binomial state which is always antibunched, is not always higher order squeezed and NLVSS which shows higher order squeezing does not show HOSPS and HOA. The opposite is observed in NLESS and consequently it is established that the HOSPS and HOS are two independent signatures of higher order nonclassicality

  19. Petroleum: The Petroleum (Carbon Disulphide) Order, 1958 

    E-print Network

    Agnew, W.G.

    1958-01-01

    The Order in Council now revoked by Article 2 of this Order when originally made applied to bisulphide of carbon the provisions of the Acts repealed and replaced by the Petroleum (Consolidation) Act, 1928, relating to the ...

  20. 40 CFR 90.503 - Test orders.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...19 KILOWATTS Selective Enforcement Auditing § 90.503 Test orders. ...by the manufacturer, pursuant to the requirements of the applicable section of subpart...manufacturer more Selective Enforcement Auditing (SEA) test orders than an annual...

  1. 40 CFR 89.503 - Test orders.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...COMPRESSION-IGNITION ENGINES Selective Enforcement Auditing § 89.503 Test orders. (a...by the manufacturer, pursuant to the requirements of the applicable section of subpart...manufacturer more Selective Enforcement Auditing (SEA) test orders than an annual...

  2. 40 CFR 164.123 - Emergency order.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... RULES OF PRACTICE GOVERNING HEARINGS, UNDER THE FEDERAL INSECTICIDE, FUNGICIDE, AND RODENTICIDE ACT, ARISING FROM REFUSALS...121 and 164.122, but the suspension order shall remain in effect during the hearing pending the issuance of a final order...

  3. 40 CFR 164.123 - Emergency order.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... RULES OF PRACTICE GOVERNING HEARINGS, UNDER THE FEDERAL INSECTICIDE, FUNGICIDE, AND RODENTICIDE ACT, ARISING FROM REFUSALS...121 and 164.122, but the suspension order shall remain in effect during the hearing pending the issuance of a final order...

  4. 40 CFR 164.123 - Emergency order.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... RULES OF PRACTICE GOVERNING HEARINGS, UNDER THE FEDERAL INSECTICIDE, FUNGICIDE, AND RODENTICIDE ACT, ARISING FROM REFUSALS...121 and 164.122, but the suspension order shall remain in effect during the hearing pending the issuance of a final order...

  5. ?1 Minimization via Randomized First Order Algorithms

    E-print Network

    2011-06-05

    Abstract. In this paper we propose randomized first-order algorithms for solving ... This paper is motivated by the desire to develop efficient randomized first-order methods ...... indeed are conservative when thinking how large could St ?St?1.

  6. 20 CFR 355.24 - Protective order.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...order. 355.24 Section 355.24 Employees' Benefits RAILROAD RETIREMENT BOARD ADMINISTRATIVE REMEDIES FOR FRAUDULENT...contents of discovery or evidence be sealed; (7) That a deposition after being sealed be opened only by order of the...

  7. 20 CFR 355.24 - Protective order.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...order. 355.24 Section 355.24 Employees' Benefits RAILROAD RETIREMENT BOARD ADMINISTRATIVE REMEDIES FOR FRAUDULENT...contents of discovery or evidence be sealed; (7) That a deposition after being sealed be opened only by order of the...

  8. 20 CFR 355.24 - Protective order.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...order. 355.24 Section 355.24 Employees' Benefits RAILROAD RETIREMENT BOARD ADMINISTRATIVE REMEDIES FOR FRAUDULENT...contents of discovery or evidence be sealed; (7) That a deposition after being sealed be opened only by order of the...

  9. 20 CFR 355.24 - Protective order.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...order. 355.24 Section 355.24 Employees' Benefits RAILROAD RETIREMENT BOARD ADMINISTRATIVE REMEDIES FOR FRAUDULENT...contents of discovery or evidence be sealed; (7) That a deposition after being sealed be opened only by order of the...

  10. 20 CFR 355.24 - Protective order.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...order. 355.24 Section 355.24 Employees' Benefits RAILROAD RETIREMENT BOARD ADMINISTRATIVE REMEDIES FOR FRAUDULENT...contents of discovery or evidence be sealed; (7) That a deposition after being sealed be opened only by order of the...

  11. Prioritization and control of order picking system

    E-print Network

    Kanburapa, Prachyathit

    2013-01-01

    Order Picking System (OPS) efficiency at a warehouse was studied with the goal of reducing production order lead time to 8 hours. Current material flow system and strategy were studied through interviews with personnel ...

  12. 10 CFR 490.602 - Special orders.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... false Special orders. 490.602 Section 490.602 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Investigations and Enforcement § 490.602 Special orders. (a) DOE may...

  13. 10 CFR 490.602 - Special orders.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... false Special orders. 490.602 Section 490.602 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Investigations and Enforcement § 490.602 Special orders. (a) DOE may...

  14. 28 CFR 2.58 - Prior orders.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS, YOUTH OFFENDERS, AND JUVENILE DELINQUENTS United States Code Prisoners and Parolees § 2.58 Prior orders. Any order of...

  15. 28 CFR 2.58 - Prior orders.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS, YOUTH OFFENDERS, AND JUVENILE DELINQUENTS United States Code Prisoners and Parolees § 2.58 Prior orders. Any order of...

  16. 28 CFR 2.58 - Prior orders.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS, YOUTH OFFENDERS, AND JUVENILE DELINQUENTS United States Code Prisoners and Parolees § 2.58 Prior orders. Any order of...

  17. 46 CFR Sec. 7 - Job order numbering.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 7 Job order numbering. (a) The NSA-LUMPSUMREP Contract number shall be inserted in every job order and supplemental job...

  18. 46 CFR Sec. 7 - Job order numbering.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 7 Job order numbering. (a) The NSA-LUMPSUMREP Contract number shall be inserted in every job order and supplemental job...

  19. 46 CFR Sec. 7 - Job order numbering.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 7 Job order numbering. (a) The NSA-LUMPSUMREP Contract number shall be inserted in every job order and supplemental job...

  20. 46 CFR Sec. 7 - Job order numbering.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 7 Job order numbering. (a) The NSA-LUMPSUMREP Contract number shall be inserted in every job order and supplemental job...

  1. 46 CFR Sec. 7 - Job order numbering.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...ACCOMPLISHMENT OF VESSEL REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 7 Job order numbering. (a) The NSA-LUMPSUMREP Contract number shall be inserted in every job order and supplemental job...

  2. Tunable fractional-order Fourier transformer

    SciTech Connect

    Malyutin, A A [A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2006-01-31

    A fractional two-dimensional Fourier transformer whose orders are tuned by means of optical quadrupoles is described. It is shown that in the optical scheme considered, the Fourier-transform order a element of [0,1] in one of the mutually orthogonal planes corresponds to the transform order (2-a) in another plane, i.e., to inversion and inverse Fourier transform of the order a. (laser modes and beams)

  3. Source of second order chromaticity in RHIC

    SciTech Connect

    Luo, Y.; Gu, X.; Fischer, W.; Trbojevic, D.

    2011-01-01

    In this note we will answer the following questions: (1) what is the source of second order chromaticities in RHIC? (2) what is the dependence of second order chromaticity on the on-momentum {beta}-beat? (3) what is the dependence of second order chromaticity on {beta}* at IP6 and IP8? To answer these questions, we use the perturbation theory to numerically calculate the contributions of each quadrupole and sextupole to the first, second, and third order chromaticities.

  4. 14 CFR 16.243 - Consent orders.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Consent orders. 16.243 Section 16.243...PROCEEDINGS Hearings § 16.243 Consent orders. (a) The agency attorney...to dispose of the case by issuance of a consent order. Good faith efforts to...

  5. Ordering Tax Transcripts A. Online Request

    E-print Network

    Wagner, Diane

    Ordering Tax Transcripts A. Online Request Go to: www.irs.gov In the "Online Services" section, select "Order a Tax Return or Account Transcript". Click "Order a Transcript" Provide tax filer's SSN "Return Transcript" and the appropriate year in "Tax Year" field. If successfully linked, tax filers can

  6. A new ordered bed modular reactor concept

    Microsoft Academic Search

    Jiafu Tian

    2007-01-01

    The Ordered Bed Modular Reactor (OBMR) is an advanced modular HTGR design in which the annular reactor core is filled with an ordered bed of fuel spheres. This arrangement allows fuel elements to be poured into the core cavity which is shaped so that an ordered bed is formed and to be discharged from the core through the opening holes

  7. Spontaneous order: Michael Polanyi and Friedrich Hayek

    Microsoft Academic Search

    Struan Jacobs

    2000-01-01

    This paper compares Hayek and Polanyi on spontaneous social order. Although Hayek is widely believed to have first both coined the name and explicated the idea of ‘spontaneous order’, it is in fact Michael Polanyi who did so. Numerous differences emerge between the two thinkers. The characterisation of spontaneous order in Hayek, for example, involves different types of freedom to

  8. Asymptotic linear prediction of extreme order statistics

    Microsoft Academic Search

    H. N. Nagaraja

    1984-01-01

    Summary  We consider the problem of predicting thesth order statistic using the lowestr order statistics from a large sample of sizen under the assumption that the sample minimum, appropriately normalized, has a non-degenerate limit distribution asn??. Assumingr, s fixed andn?? we obtain asymptotically best linear unbiased as well as asymptotically best linear invariant predictors of thesth order statistic.

  9. Natural Language Syntax First Order Inference

    E-print Network

    Givan, Bob

    Natural Language Syntax and First Order Inference David McAllester and Robert Givan MIT Artificial­standard syntax for first order logic. In this paper we define a syntax for first order logic based than analogous procedures based on either classical or taxonomic syntax. This paper appeared

  10. The Interval Order Polytope of a Digraph

    E-print Network

    Rudolf Müller; Andreas S. Schulz

    1995-01-01

    . We introduce the interval order polytope of a digraph D as the convex hull of interval order inducing arc subsets of D. Two general schemes for producing valid inequalities are presented. These schemes have been used implicitly for several polytopes and they are applied here to the interval order

  11. Ordering methods for multivariate RCRS filters

    Microsoft Academic Search

    Heikki Huttunen; Marius Tico; Corneliu Rusu; Pauli Kuosmanen

    1999-01-01

    Different types of mappings for ordering of multivariate data are considered. The resulting orderings are then used to ex- tend the rank conditioned rank selection (RCRS) filters such that they operate on multivariate data, such as color images. Experimental results and comparison of different ordering strategies are then presented.

  12. Half Orders of Magnitude Jerry R. Hobbs

    E-print Network

    Hobbs, Jerry R.

    Half Orders of Magnitude Jerry R. Hobbs USC Information Sciences Institute Marina del Rey with precise values for quantities we encounter in everyday life. We can easily come up with order­of­magnitude. However, people find it nearly as easy to come up with half­order­of­ magnitude estimates

  13. Half Orders of Magnitude Jerry R. Hobbs

    E-print Network

    Hobbs, Jerry R.

    Half Orders of Magnitude Jerry R. Hobbs USC Information Sciences Institute Marina del Rey with precise values for quantities we encounter in everyday life. We can easily come up with order-of-magnitude. However, people find it nearly as easy to come up with half-order-of- magnitude estimates

  14. Ordered Intermetallics as Electrocatalysts for Fuel Cell

    E-print Network

    Ordered Intermetallics as Electrocatalysts for Fuel Cell Applications Héctor D. Abruña) plane Pt-Pt 4.32 Å #12;Alloys vs. Ordered Intermetallics (A) Alloy; e.g. Pt/Ru (1:1) (B) Ordered Intermetallic e.g. BiPt #12;Bismuth Platinum (BiPt) Intermetallic Phase Powder Refinement for Bi

  15. NUFinancials SubmitRequestChangePurchaseOrder

    E-print Network

    Shull, Kenneth R.

    make changes to a Purchase Order using the PO Change Order Request Center in NUFinancials (when you can you be able to: · Identify the status of a Requisition/PO in Manage Requisitions to determine if you can create a PO Change Request. · Submit a PO Change Request using the PO Change Order Request Center

  16. Topology of electronic bands and Topological Order

    E-print Network

    Topology of electronic bands and Topological Order R. Shankar The Institute of Mathematical Sciences, Chennai TIFR, 26th April, 2011 #12;Outline IQHE and the Chern Invariant Topological insulators and the Z2 invariant Topological order Exactly solved models with topological order A model with everything

  17. Telecommunications VoIP Work Order

    E-print Network

    Telecommunications VoIP Work Order 1. Fax the completed form to 979.847.1111. 2. **After you submit the work order via fax, please email a Word copy (non pdf) of this work order to voip@tamu.edu. 3. If you

  18. Order Forecast of Cigarette Distribution Center

    Microsoft Academic Search

    Yaohua Wu; Zuoling Song; Danyu Zhang

    2007-01-01

    The thesis forecasts order of Cigarette Distribution Center by period, brand, district, from several dimensions. The thesis uses different models and analyses forecast results. When forecasting year's order amount, the mean accuracy of Logarithm Regression Model is highest, gets 98.45%. When forecasting month's order amount of cigarette, the thesis uses Genetic Algorithm (GA) to optimize BP neural networks, and overcomes

  19. Abel's Theorem Simplifies Reduction of Order

    ERIC Educational Resources Information Center

    Green, William R.

    2011-01-01

    We give an alternative to the standard method of reduction or order, in which one uses one solution of a homogeneous, linear, second order differential equation to find a second, linearly independent solution. Our method, based on Abel's Theorem, is shorter, less complex and extends to higher order equations.

  20. Second-order magnetoelectric susceptibility in the optical region: The case of boracite Cu3B7O13Br

    NASA Astrophysics Data System (ADS)

    Krichevtsov, B. B.; Zyuzin, A. Yu.; Weber, H.-J.

    2003-11-01

    In the cubic phase of boracite Cu3B7O13Br (symmetry class Td) the anisotropy and dispersion of nonreciprocal linear dichroism (ND) and nonreciprocal linear birefringence (NB) have been studied. The two magnetic-field-induced effects belong to the class of spatial dispersion phenomena. They have been observed near to the two strong absorption bands at the photon energies E01=1.5 eV and E02=1.2 eV. E01 and E02 are assigned to electronic transitions from the singlet ground state 2B2 to states of the doublet 2E. The analysis of dispersion of ND and NB is based on the crystal-field theory whereby spin-orbit coupling and Zeeman interaction have been included. An adequate description is obtainable only if the symmetry of the crystal field at Cu2+ ions is lower than tetragonal. Two mechanisms are discussed as the origin of symmetry reduction. At first, a structural disorder of halogen and/or metal ions in the boracite crystal lattice produces low-symmetry components of the crystal field and these components split the excited state 2E. Second, symmetry is reduced by the dynamic Jahn-Teller effect.

  1. Higher-order artificial neural networks

    SciTech Connect

    Bengtsson, M.

    1990-12-01

    The report investigates the storage capacity of an artificial neural network where the state of each neuron depends on quadratic correlations of all other neurons, i.e. a third order network. This is in contrast to a standard Hopfield network where the state of each single neuron depends on the state on every other neuron, without any correlations. The storage capacity of a third order network is larger than that for standard Hopfield by one order of N. However, the number of connections is also larger by an order of N. It is shown that the storage capacity per connection is identical for standard Hopfield and for this third order network.

  2. The role of order in distributed programs

    NASA Technical Reports Server (NTRS)

    Birman, Kenneth P.; Marzullo, Keith

    1989-01-01

    The role of order in building distributed systems is discussed. It is the belief that a principle of event ordering underlies the wide range of operating systems mechanisms that were put forward for building robust distributed software. Stated concisely, this principle achieves correct distributed behavior by ordering classes of distributed events that conflict with one another. By focusing on order, simplified descriptions can be obtained and convincingly correct solutions to problems that might otherwise have looked extremely complex. Moreover, it is observed that there are a limited number of ways to obtain order, and that the choice made impacts greatly on performance.

  3. Binocular Combination of Second-Order Stimuli

    PubMed Central

    Zhou, Jiawei; Liu, Rong; Zhou, Yifeng; Hess, Robert F.

    2014-01-01

    Phase information is a fundamental aspect of visual stimuli. However, the nature of the binocular combination of stimuli defined by modulations in contrast, so-called second-order stimuli, is presently not clear. To address this issue, we measured binocular combination for first- (luminance modulated) and second-order (contrast modulated) stimuli using a binocular phase combination paradigm in seven normal adults. We found that the binocular perceived phase of second-order gratings depends on the interocular signal ratio as has been previously shown for their first order counterparts; the interocular signal ratios when the two eyes were balanced was close to 1 in both first- and second-order phase combinations. However, second-order combination is more linear than previously found for first-order combination. Furthermore, binocular combination of second-order stimuli was similar regardless of whether the carriers in the two eyes were correlated, anti-correlated, or uncorrelated. This suggests that, in normal adults, the binocular phase combination of second-order stimuli occurs after the monocular extracting of the second-order modulations. The sensory balance associated with this second-order combination can be obtained from binocular phase combination measurements. PMID:24404180

  4. First-order inflation. [in cosmology

    NASA Technical Reports Server (NTRS)

    Kolb, Edward W.

    1991-01-01

    In the original proposal, inflation occurred in the process of a strongly first-order phase transition. This model was soon demonstrated to be fatally flawed. Subsequent models for inflation involved phase transitions that were second-order, or perhaps weakly first-order; some even involved no phase transition at all. Recently the possibility of inflation during a strongly first-order phase transition has been revived. In this paper, some models for first-order inflation are discussed, and unique signatures that result if inflation is realized in a first-order transition are emphasized. Some of the history of inflation is reviewed to demonstrate how first-order inflation differs from other models.

  5. 19 CFR 351.211 - Antidumping order and countervailing duty order.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...duty order. (a) Introduction. The Secretary issues an order when both the Secretary and the...general, as well as special rules for orders where the Commission has found a regional industry to exist. (b) In...

  6. 19 CFR 351.211 - Antidumping order and countervailing duty order.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...duty order. (a) Introduction. The Secretary issues an order when both the Secretary and the...general, as well as special rules for orders where the Commission has found a regional industry to exist. (b) In...

  7. 19 CFR 351.211 - Antidumping order and countervailing duty order.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...duty order. (a) Introduction. The Secretary issues an order when both the Secretary and the...general, as well as special rules for orders where the Commission has found a regional industry to exist. (b) In...

  8. 19 CFR 351.211 - Antidumping order and countervailing duty order.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...duty order. (a) Introduction. The Secretary issues an order when both the Secretary and the...general, as well as special rules for orders where the Commission has found a regional industry to exist. (b) In...

  9. 19 CFR 351.211 - Antidumping order and countervailing duty order.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...duty order. (a) Introduction. The Secretary issues an order when both the Secretary and the...general, as well as special rules for orders where the Commission has found a regional industry to exist. (b) In...

  10. Order Parameters for Two-Dimensional Networks

    NASA Astrophysics Data System (ADS)

    Kaatz, Forrest; Bultheel, Adhemar; Egami, Takeshi

    2007-10-01

    We derive methods that explain how to quantify the amount of order in ``ordered'' and ``highly ordered'' porous arrays. Ordered arrays from bee honeycomb and several from the general field of nanoscience are compared. Accurate measures of the order in porous arrays are made using the discrete pair distribution function (PDF) and the Debye-Waller Factor (DWF) from 2-D discrete Fourier transforms calculated from the real-space data using MATLAB routines. An order parameter, OP3, is defined from the PDF to evaluate the total order in a given array such that an ideal network has the value of 1. When we compare PDFs of man-made arrays with that of our honeycomb we find OP3=0.399 for the honeycomb and OP3=0.572 for man's best hexagonal array. The DWF also scales with this order parameter with the least disorder from a computer-generated hexagonal array and the most disorder from a random array. An ideal hexagonal array normalizes a two-dimensional Fourier transform from which a Debye-Waller parameter is derived which describes the disorder in the arrays. An order parameter S, defined by the DWF, takes values from [0, 1] and for the analyzed man-made array is 0.90, while for the honeycomb it is 0.65. This presentation describes methods to quantify the order found in these arrays.

  11. Odd orders in Shor's factoring algorithm

    NASA Astrophysics Data System (ADS)

    Lawson, Thomas

    2015-03-01

    Shor's factoring algorithm (SFA) finds the prime factors of a number, , exponentially faster than the best known classical algorithm. Responsible for the speedup is a subroutine called the quantum order finding algorithm (QOFA) which calculates the order—the smallest integer, , satisfying , where is a randomly chosen integer coprime to (meaning their greatest common divisor is one, ). Given , and with probability not 1/2, the factors are given by and . For odd , it is assumed that the factors cannot be found (since is not generally integer) and the QOFA is relaunched with a different value of . But a recent paper (Martin-Lopez et al. Nat. Photonics 6:773, 2012) noted that the factors can sometimes be found from odd orders if the coprime is square. This raises the question of improving SFA's success probability by considering odd orders. We show that an improvement is possible, though it is small. We present two techniques for retrieving the order from apparently useless runs of the QOFA: not discarding odd orders; and looking out for new order finding relations in the case of failure. In terms of efficiency, using our techniques is equivalent to avoiding square coprimes and disregarding odd orders, which is simpler in practice. Even still, our techniques may be useful in the near future, while demonstrations are restricted to factoring small numbers. The most convincing demonstrations of the QOFA are those that return a non-power-of-two order, making odd orders that lead to the factors attractive to experimentalists.

  12. Control of Initialized Fractional-Order Systems

    NASA Technical Reports Server (NTRS)

    Hartly, Tom T.; Lorenzo, Carl F.

    2002-01-01

    Due to the importance of historical effects in fractional-order systems, this paper presents a general fractional-order control theory that includes the time-varying initialization response. Previous studies have not properly accounted for these historical effects. The initialization response, along with the forced response, for fractional-order systems is determined. Stability properties of fractional-order systems are presented in the complex Airplane, which is a transformation of the s-plane. Time responses are discussed with respect to pole positions in the complex Airplane and frequency response behavior is included. A fractional-order vector space representation, which is a generalization of the state space concept, is presented including the initialization response. Control methods for vector representations of initialized fractional-order systems are shown. Nyquist, root-locus, and other input-output control methods are adapted to the control of fractional-order systems. Finally, the fractional-order differintegral is generalized to continuous order-distributions that have the possibility of including a continuum of fractional orders in a system element.

  13. Two variants of minimum discarded fill ordering

    SciTech Connect

    D'Azevedo, E.F. (Oak Ridge National Lab., TN (USA)); Forsyth, P.A.; Tang, Wei-Pai (Waterloo Univ., ON (Canada). Dept. of Computer Science)

    1991-01-01

    It is well known that the ordering of the unknowns can have a significant effect on the convergence of Preconditioned Conjugate Gradient (PCG) methods. There has been considerable experimental work on the effects of ordering for regular finite difference problems. In many cases, good results have been obtained with preconditioners based on diagonal, spiral or natural row orderings. However, for finite element problems having unstructured grids or grids generated by a local refinement approach, it is difficult to define many of the orderings for more regular problems. A recently proposed Minimum Discarded Fill (MDF) ordering technique is effective in finding high quality Incomplete LU (ILU) preconditioners, especially for problems arising from unstructured finite element grids. Testing indicates this algorithm can identify a rather complicated physical structure in an anisotropic problem and orders the unknowns in the preferred'' direction. The MDF technique may be viewed as the numerical analogue of the minimum deficiency algorithm in sparse matrix technology. At any stage of the partial elimination, the MDF technique chooses the next pivot node so as to minimize the amount of discarded fill. In this work, two efficient variants of the MDF technique are explored to produce cost-effective high-order ILU preconditioners. The Threshold MDF orderings combine MDF ideas with drop tolerance techniques to identify the sparsity pattern in the ILU preconditioners. These techniques identify an ordering that encourages fast decay of the entries in the ILU factorization. The Minimum Update Matrix (MUM) ordering technique is a simplification of the MDF ordering and is closely related to the minimum degree algorithm. The MUM ordering is especially for large problems arising from Navier-Stokes problems. Some interesting pictures of the orderings are presented using a visualization tool. 22 refs., 4 figs., 7 tabs.

  14. Variable-order fuzzy fractional PID controller.

    PubMed

    Liu, Lu; Pan, Feng; Xue, Dingyu

    2015-03-01

    In this paper, a new tuning method of variable-order fractional fuzzy PID controller (VOFFLC) is proposed for a class of fractional-order and integer-order control plants. Fuzzy logic control (FLC) could easily deal with parameter variations of control system, but the fractional-order parameters are unable to change through this way and it has confined the effectiveness of FLC. Therefore, an attempt is made in this paper to allow all the five parameters of fractional-order PID controller vary along with the transformation of system structure as the outputs of FLC, and the influence of fractional orders ? and ? on control systems has been investigated to make the fuzzy rules for VOFFLC. Four simulation results of different plants are shown to verify the availability of the proposed control strategy. PMID:25440947

  15. Symmetry, ordering and arranging compulsive behaviour.

    PubMed

    Radomsky, A S; Rachman, S

    2004-08-01

    Compulsive ordering and arranging, and a preoccupation with symmetry are features of obsessive-compulsive disorder (OCD) that have not been examined experimentally. Three connected studies were conducted to examine this phenomenon: a self-report measure of this behaviour was developed and validated, participants were asked to engage in tasks designed to assess preferences for order, and to assess the interference of disorderly surroundings in the completion of a stressful activity. The self-report measure has sound psychometric properties and validity. Participants with a strong preference for order were made more anxious by having to complete a difficult task in a disorganized environment. Participants without this preference did not show this effect. The results are discussed in terms of the phenomenology of compulsive ordering and arranging, and its relationships with both OCD and normal human behaviour. It is suggested that compulsive ordering and a drive for symmetry are extreme manifestations of the common preference for order and symmetry. PMID:15178465

  16. Duplicate Orders: An Unintended Consequence of Computerized provider/physician order entry (CPOE) Implementation

    PubMed Central

    Magid, S.; Forrer, C.; Shaha, S.

    2012-01-01

    Objective Computerized provider/physician order entry (CPOE) with clinical decision support (CDS) is designed to improve patient safety. However, a number of unintended consequences which include duplicate ordering have been reported. The objective of this time-series study was to characterize duplicate orders and devise strategies to minimize them. Methods Time series design with systematic weekly sampling for 84 weeks. Each week we queried the CPOE database, downloaded all active orders onto a spreadsheet, and highlighted duplicate orders. We noted the following details for each duplicate order: time, order details (e.g. drug, dose, route and frequency), ordering prescriber, including position and role, and whether the orders originated from a single order or from an order set (and the name of the order set). This analysis led to a number of interventions, including changes in: order sets, workflow, prescriber training, pharmacy procedures, and duplicate alerts. Results Duplicates were more likely to originate from different prescribers than from same prescribers; and from order sets than from single orders. After interventions, there was an 84.8% decrease in the duplication rate from weeks 1 to 84 and a 94.6% decrease from the highest (1) to the lowest week (75). Currently, we have negligible duplicate orders. Conclusions Duplicate orders can be a significant unintended consequence of CPOE. By analyzing these orders, we were able to devise and implement generalizable strategies that significantly reduced them. The incidence of duplicate orders before CPOE implementation is unknown, and our data originate from a weekly snapshot of active orders, which serves as a sample of total active orders. Thus, it should be noted that this methodology likely under-reports duplicate orders. PMID:23646085

  17. On k?ordered Hamiltonian graphs

    Microsoft Academic Search

    Gabor N. Sarkozy; Stanley Selkow

    1999-01-01

    A Hamiltonian graph $G$ of order $n$ is $k$-ordered, $2\\\\leq k \\\\leq n$, if\\u000afor every sequence $v_1, v_2, \\\\ldots ,v_k$ of $k$ distinct vertices of $G$,\\u000athere exists a Hamiltonian cycle that encounters $v_1, v_2, \\\\ldots , v_k$ in\\u000athis order. In this paper, answering a question of Ng and Schultz, we give a\\u000asharp bound for the minimum

  18. Formation of nematic ordered cellulose and chitin

    Microsoft Academic Search

    Tetsuo Kondo; Wakako Kasai; R. Malcolm Brown

    2004-01-01

    We proposed in a previous paper a unique form of ß-glucan association, nematic ordered cellulose (NOC) that is molecularly ordered, yet non-crystalline. NOC has unique characteristics; in particular, its surface properties provide with a function of tracks or scaffolds for regulated movements and fiber-production of Acetobacter xylinum [Kondo et al. 2002. Proc. Natl. Acad. Sci. USA 99: 14008–14013]. In order

  19. The Twelve Soil Orders - Soil Taxonomy

    NSDL National Science Digital Library

    This University of Idaho website discusses the twelve orders of soils, and provides images that illustrate the distribution, properties, and use of the soil orders. It provides general information on each of the twelve orders with a description, a U.S. map showing soil locations, and pictures of the soil type. A Global Distribution Map indicates locations of each soil type throughout the world.

  20. Model-checking higher-order functions

    Microsoft Academic Search

    Naoki Kobayashi

    2009-01-01

    We propose a novel type-based model checking algorithm for higher-order recursion schemes. As shown by Kobayashi, verifi- cation problems of higher-order functional programs can easily be translated into model checking problems of recursion schemes. Thus, the model checking algorithm serves as a basis for verifica- tion of higher-order functional programs. To our knowledge, this is the first practical algorithm for

  1. An overview of task order 10

    SciTech Connect

    Rousculp, Christopher L [Los Alamos National Laboratory

    2011-01-12

    Task Order 10 formalizes a collaboration in high explosive pulsed power (HEPP) experiments between LANL and VNIIEF. The focus is the VNIIEF disk explosive magnetic generator (DEMG) technology. The task order outlines a sequence of tasks and deliverables culminating in an experiment which takes place in the US utilizing US explosives and a Russian DEMG. This talk summarizes task order 10. It gives a brief history and present status in terms of the proposed high pressure EOS experiment (ALT-3).

  2. Marketing Milk Under Federal Orders in Texas.

    E-print Network

    Stelly, Randall

    1960-01-01

    ITIN 959 JULY 1960 llarketinff Milk un er Federal Orders in Texas order ZAIm includes Beckman county, Oklahoma. 3Also includes eight counties in Oklahoma. TEXAS AGRICULTURAL EXPERIMENT STATION R. D. LEWIS, DIRECTOR. COLLEGE STATION, TEXAS... SUMMARY Some Texas dairy farmers have been market- ing milk under federal orders since October 1951. In December 1959, 5,270, or 68 percent of Texas producers sold milk under the seven federal or- ders. In 1959 these producers marketed more than 1...

  3. Metric Semantics from Partial Order Semantics

    Microsoft Academic Search

    Christel Baier; Mila E. Majster-cederbaum

    1997-01-01

    .   In dealing with denotational semantics of programming languages partial orders resp. metric spaces have been used with great\\u000a benefit in order to provide a meaning to recursive and repetitive constructs. This paper presents two methods to define a\\u000a metric on a subset of a complete partial order such that is a complete metric spaces and the metric semantics on

  4. Executive Orders and Historical Order: Implications of the Evolution of U.S. Executive Orders for Political Science and Politics

    Microsoft Academic Search

    Graham G. Dodds

    This paper sketches several implications of my recently completed study of the development of U.S. presidential executive orders for broader debates in scholarship on the American presidency, American political development, and American politics in general. I suggest that an understanding of the evolution of executive orders indicates that (1) the true roots of presidential power are legal and constitutional rather

  5. Optical method of atomic ordering estimation

    SciTech Connect

    Prutskij, T. [Instituto de Ciencias, BUAP, Privada 17 Norte, No 3417, col. San Miguel Huyeotlipan, Puebla, Pue. (Mexico); Attolini, G. [IMEM/CNR, Parco Area delle Scienze 37/A - 43010, Parma (Italy); Lantratov, V.; Kalyuzhnyy, N. [Ioffe Physico-Technical Institute, 26 Polytekhnicheskaya, St Petersburg 194021, Russian Federation (Russian Federation)

    2013-12-04

    It is well known that within metal-organic vapor-phase epitaxy (MOVPE) grown semiconductor III-V ternary alloys atomically ordered regions are spontaneously formed during the epitaxial growth. This ordering leads to bandgap reduction and to valence bands splitting, and therefore to anisotropy of the photoluminescence (PL) emission polarization. The same phenomenon occurs within quaternary semiconductor alloys. While the ordering in ternary alloys is widely studied, for quaternaries there have been only a few detailed experimental studies of it, probably because of the absence of appropriate methods of its detection. Here we propose an optical method to reveal atomic ordering within quaternary alloys by measuring the PL emission polarization.

  6. Some inequalities for orderings of acyclic digraphs

    E-print Network

    Bier, Thomas

    2011-01-01

    For any acyclic ordering $g$ of a finite acyclic digraph $D$ we obtain a lower bound inequality for the inner product of its $e-$vector and $g.$ Here the $e-$vector is defined to be the difference of the indegree and the outdegree of the underlying acyclic digraph. This gives a lower bound on the functional $ T_e(f) = ,$ defined on the set of all acyclic orderings of $D.$ The class of acyclic digraphs which admit an acyclic ordering attaining the lower bound is determined as the class of posets of order dimension two.

  7. Second-Order Gravitational Self-Force

    NASA Astrophysics Data System (ADS)

    Pound, Adam

    2015-01-01

    In order to extract physical parameters from the waveform of an extreme-mass-ratio binary, one requires a second-order-accurate description of the motion of the smaller of the two objects in the binary. Using a method of matched asymptotic expansions, I derive the second-order equation of motion of a small, nearly spherical and non-rotating compact object in an arbitrary vacuum spacetime. I find that the motion is geodesic in a certain locally defined effective metric satisfying the vacuum Einstein equation through second order, and I outline a method of numerically determining this effective metric.

  8. Chaos in a Fractional Order Chua System

    NASA Technical Reports Server (NTRS)

    Lorenzo, Carl F.; Hartley, Tom T.; Qammar, Helen Killory

    1996-01-01

    This report studies the effects of fractional dynamics in chaotic systems. In particular, Chua's system is modified to include fractional order elements. Varying the total system order incrementally from 2.6 to 3.7 demonstrates that systems of 'order' less than three can exhibit chaos as well as other nonlinear behavior. This effectively forces a clarification of the definition of order which can no longer be considered only by the total number of differentiations or by the highest power of the Laplace variable.

  9. Paths and stochastic order in open systems

    E-print Network

    Umberto Lucia

    2011-01-07

    The principle of maximum irreversible is proved to be a consequence of a stochastic order of the paths inside the phase space; indeed, the system evolves on the greatest path in the stochastic order. The result obtained is that, at the stability, the entropy generation is maximum and, this maximum value is consequence of the stochastic order of the paths in the phase space, while, conversely, the stochastic order of the paths in the phase space is a consequence of the maximum of the entropy generation at the stability.

  10. An Empirical Analysis of the Limit Order Book and the Order Flow in the Paris Bourse

    Microsoft Academic Search

    Bruno Biais; Pierre Hillion; Chester Spatt

    1995-01-01

    As a centralized, computerized, limit order market, the Paris Bourse is particularly appropriate for studying the interaction between the order book and order flow. Descriptive methods capture the richness of the data and distinctive aspects of the market structure. Order flow is concentrated near the quote, while the depth of the book is somewhat larger at nearby valuations. We analyze

  11. Symmetry Properties of Second Order Hyperpolarizabilities

    Microsoft Academic Search

    J. W. Wu

    1994-01-01

    Time-reversal symmetry property of a second order nonlinear optical hyperpolarizability is examined in terms of the Manley-Rowe power relation to find relationship to the overall permutation symmetry. An extended symmetry relation is discovered reducing the independent number of the hyperpolarizability tensor components describing the second order nonlinear optical processes. Experimental implications are discussed.

  12. Texas Union Pizza Order Form ROOM RESERVED ______________________________________________________

    E-print Network

    Jefferys, William

    #12;#12;Texas Union Pizza Order Form ROOM RESERVED: ________________________________________________________________________________________________ ________________________________________________________________________________________________ ________________________________________________________________________________________________ ________________________________________________________________________________________________ ________________________________________________________________________________________________ ________________________________________________________________________________________________ ________________________________________________________________________________________________ ________________________________________________________________________________________________ Pick-up All orders are to be picked up at the Texas Union Hospitality Center desk in the south end West with the Texas Union Policies and Procedures. I understand that I will be held responsible for any debts incurred

  13. 48 CFR 16.505 - Ordering.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    (1) In general, the contracting officer does not synopsize orders under indefinite-delivery contracts; but see 16.505(a)(10) for orders funded in whole or in part by the American Recovery and Reinvestment Act of 2009 (Pub. L....

  14. Axiomatizing first order consequences in dependence logic

    E-print Network

    Väänänen, Jouko

    Axiomatizing first order consequences in dependence logic Juha Kontinen Jouko V¨a¨an¨anen May 18, 2012 Abstract Dependence logic, introduced in [8], cannot be axiomatized. However, first-order consequences of dependence logic sentences can be axiomatized, and this is what we shall do in this paper. We

  15. Nematic Ordered Cellulose: Its Structure and Properties

    Microsoft Academic Search

    Tetsuo Kondo

    The authors developed a unique form of ?-glucan association, “nematic ordered cellulose” (NOC) that is molecularly ordered, yet noncrystalline. NOC has unique characteristics; in particular, its surface properties provide with a function of tracks or scaffolds for regulated movements and fiber production of Acetobacter xylinum (=Gluconacetobacter xylinus), which produces cellulose ribbon-like nanofibers with 40–60 nm in width and moves due

  16. Seismic imaging using higher order statistics

    E-print Network

    Srinivasan, Karthik

    1999-01-01

    the resulting algorithm is a cross-correlation (second order statistics) operation whose region of support is limited to the bandwidth of the source signal. This is not the case for non-vanishing higher order cumulates where the support region can be extended...

  17. Pedophilia, Sexual Orientation, and Birth Order

    Microsoft Academic Search

    Anthony F. Bogaert; Scott Bezeau; Michael Kuban; Ray Blanchard

    1997-01-01

    This study extended research on birth order and erotic preferences by examining birth order in a sample of pedophiles. Charts of 338 pedophiles, assessed from 1980–1994 in the Behavioural Sexology Department of the Clarke Institute of Psychiatry in Toronto, were reviewed for family–demographic information. In total, 170 (57 heterosexual pedophiles, 68 homosexual pedophiles, and 45 bisexual pedophiles) of these men

  18. Higher-Order Logic Programming Gopalan Nadathur

    E-print Network

    Miller, Dale

    in Artificial Intelligence and Logic Programming, D. Gabbay, C. Hogger and A. Robinson (eds.), Oxford UniversityHigher-Order Logic Programming Gopalan Nadathur Computer Science Department, Duke University 7 Examples of Higher-Order Programming 45 7.1 A Concrete Syntax for Programs

  19. Higher-Order Neural Networks Recognize Patterns

    NASA Technical Reports Server (NTRS)

    Reid, Max B.; Spirkovska, Lilly; Ochoa, Ellen

    1996-01-01

    Networks of higher order have enhanced capabilities to distinguish between different two-dimensional patterns and to recognize those patterns. Also enhanced capabilities to "learn" patterns to be recognized: "trained" with far fewer examples and, therefore, in less time than necessary to train comparable first-order neural networks.

  20. A Note on Canonical Word Order

    ERIC Educational Resources Information Center

    O'Grady, William; Yamashita, Yoshie; Lee, Sun-Young

    2005-01-01

    In this brief report, we summarize the results of an experiment on the interpretation of English word order patterns by adult Korean- and Japanese-speaking second language learners. Our results suggest that a direct relationship between a construction's word order and the structure of the corresponding event has a greater facilitative effect on…

  1. Bounding Functions via Nth order Hankel Transform

    Microsoft Academic Search

    Nikolaos E. Myridis; Christodoulos Chamzas

    In this presentation we establish new bounds on functions, which have their n-th order Hankel Transform bandlimited. This class of functions is proved to be also Fourier Transform bandlimited. N-th order Hankel Transforms and the consequent bounds are important for the reconstruction in CAT, MRI (Magnetic Resonance Imaging) etc. Indeed many algorithms of modern tomography use the appropriate forms of

  2. Human motion perception: Higher-order organization

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary K.; Proffitt, Dennis R.

    1990-01-01

    An overview is given of higher-order motion perception and organization. It is argued that motion is sufficient to fully specify a number of environmental properties, including: depth order, three-dimensional form, object displacement, and dynamics. A grammar of motion perception is proposed; applications of this work for display design are discussed.

  3. Reaction Order Ambiguity in Integrated Rate Plots

    ERIC Educational Resources Information Center

    Lee, Joe

    2008-01-01

    Integrated rate plots are frequently used in reaction kinetics to determine orders of reactions. It is often emphasised, when using this methodology in practice, that it is necessary to monitor the reaction to a substantial fraction of completion for these plots to yield unambiguous orders. The present article gives a theoretical and statistical…

  4. Lateralized Temporal Order Judgement in Dyslexia

    ERIC Educational Resources Information Center

    Liddle, Elizabeth B.; Jackson, Georgina M.; Rorden, Chris; Jackson, Stephen R.

    2009-01-01

    Temporal and spatial attentional deficits in dyslexia were investigated using a lateralized visual temporal order judgment (TOJ) paradigm that allowed both sensitivity to temporal order and spatial attentional bias to be measured. Findings indicate that adult participants with a positive screen for dyslexia were significantly less sensitive to the…

  5. Entomology 201 Identification of Insecta orders

    E-print Network

    Eubanks, Micky

    Bedbugs (Hemiptera): -head tucked back in pronotum -antennae w/ 4-5 long (moniliform) segments #12;Order Hemiptera True bugs, cicadas & hoppers, aphids & scale bugs Piercing-sucking mouthparts! #12;· Unique) Order Hemiptera True bugs, cicadas & hoppers, aphids & scale bugs #12;Know the Suborders

  6. Few Fractional Order Derivatives and Their Computations

    ERIC Educational Resources Information Center

    Bhatta, D. D.

    2007-01-01

    This work presents an introductory development of fractional order derivatives and their computations. Historical development of fractional calculus is discussed. This paper presents how to obtain computational results of fractional order derivatives for some elementary functions. Computational results are illustrated in tabular and graphical…

  7. The need for a universal humanitarian order

    Microsoft Academic Search

    Michel Veuthey

    2005-01-01

    Purpose – Within the context of an international conference dealing with global challenges, the Atlantic Community and the outlook for international order organized by Webster University, Geneva (Switzerland), to propose an approach to strengthening the international order by reviving the global responsibility to abide by fundamental humanitarian rules. Design\\/methodology\\/approach – The twentieth century presented a very disturbing catalog of violations

  8. Birth Order, Family Size and Educational Attainment

    ERIC Educational Resources Information Center

    de Haan, Monique

    2010-01-01

    This paper investigates the effect of family size and birth order on educational attainment. An instrumental variables approach is used to identify the effect of family size. Instruments for the number of children are twins at last birth and the sex mix of the first two children. The effect of birth order is identified, by examining the relation…

  9. Science Orders Systems and Operations Manual.

    ERIC Educational Resources Information Center

    Kriz, Harry M.

    This manual describes the implementation and operation of SCIENCE ORDERS, an online orders management system used by the Science and Technology Department of Newman Library at Virginia Polytechnic Institute and State University. Operational since January 1985, the system is implemented using the SPIRES database management system and is used to (1)…

  10. Retrieval Strategies for Linearly Ordered Information

    ERIC Educational Resources Information Center

    Polich, John M.; Potts, George R.

    1977-01-01

    Subjects responded to pairs of test items from learned linear orderings (e.g., Tom is taller than Dick; Dick is taller than Sam, etc.). Results are compared with previous studies of ordered linguistic, perceptual, and numerical information. (Editor/RK)

  11. The Natural Order and the Human Mind

    Microsoft Academic Search

    Steven Pimentel

    From the evolution of galaxies to the development of the smallest flower, nature exhibits exquisitely intricate and complex patterns of order. Throughout history, humanity has been amazed and fascinated by these patterns. The progress of science has only deepened our aware- ness of the order of nature by extending our ability to observe natural phenomena and systemati- cally describe their

  12. Time and Order Effects on Causal Learning

    ERIC Educational Resources Information Center

    Alvarado, Angelica; Jara, Elvia; Vila, Javier; Rosas, Juan M.

    2006-01-01

    Five experiments were conducted to explore trial order and retention interval effects upon causal predictive judgments. Experiment 1 found that participants show a strong effect of trial order when a stimulus was sequentially paired with two different outcomes compared to a condition where both outcomes were presented intermixed. Experiment 2…

  13. A High Performance Totally Ordered Multicast Protocol

    Microsoft Academic Search

    Brian Whetten; Todd Montgomery; Simon M. Kaplan

    1994-01-01

    This paper presents the Reliable Multicast Protocol (RMP). RMP provides a totally ordered, reliable, atomic multicast service on top of an unreliable multicast datagram service such as IP Multicasting. RMP is fully and symmetrically distributed so that no site bears an undue portion of the communication load. RMP provides a wide range of guarantees, from unreliable delivery to totally ordered

  14. On Distributions of Generalized Order Statistics

    Microsoft Academic Search

    Udo Kamps; Erhard Cramer

    In a wide subclass of generalized order statistics, representations of marginal density and distribution functions are developed. The results are applied to obtain several rela- tions, such as recurrence relations, and explicit expressions for the moments of generalized order statistics from Pareto, power function and Weibull distributions. Moreover, charac- terizations of exponential distributions are shown by means of a distributional

  15. High-Order Digital Parametric Equalizer Design

    Microsoft Academic Search

    Sophocles J. Orfanidis

    2005-01-01

    A family of digital parametric audio equalizers based on high-order Butterworth, Chebyshev, and elliptic analog prototype filters is derived that generalizes the con- ventional biquadratic designs and provides flatter passbands and sharper bandedges. The equalizer filter coefficients are computable in terms of the center frequency, peak gain, bandwidth, and bandwidth gain. We consider the issues of filter order and bandwidth

  16. Review essay \\/ What kind of order?

    Microsoft Academic Search

    Robert Jackall

    2003-01-01

    Bernard E. Harcourt, Illusion of Order: The False Promise of Broken Windows Policing Cambridge, MA: Harvard University Press, 2001, x + 294 pp.David Garland, The Culture of Control: Crime and Social Order in Contemporary Society Chicago: University of Chicago Press, 2001, xiii + 307 pp.Andrea McArdle and Tanya Erzen (eds.), Zero Tolerance: Quality of Life and the New Police Brutality

  17. Order, chaos and nuclear dynamics: An introduction

    SciTech Connect

    Swiatecki, W.J.

    1990-08-01

    This is an introductory lecture illustrating by simple examples the anticipated effect on collective nuclear dynamics of a transition from order to chaos in the motions of nucleons inside an idealized nucleus. The destruction of order is paralleled by a transition from a rubber-like to a honey-like behaviour of the independent-particle nuclear model. 10 refs., 6 figs.

  18. Enhanced ordering temperatures in antiferromagnetic manganite superlattices.

    PubMed

    May, S J; Ryan, P J; Robertson, J L; Kim, J-W; Santos, T S; Karapetrova, E; Zarestky, J L; Zhai, X; te Velthuis, S G E; Eckstein, J N; Bader, S D; Bhattacharya, A

    2009-11-01

    The disorder inherent to doping by cation substitution in the complex oxides can have profound effects on collective-ordered states. Here, we demonstrate that cation-site ordering achieved through digital-synthesis techniques can dramatically enhance the antiferromagnetic ordering temperatures of manganite films. Cation-ordered (LaMnO3)m/(SrMnO3)2m superlattices show Néel temperatures (TN) that are the highest of any La(1-x)Sr(x)MnO3 compound, approximately 70 K greater than compositionally equivalent randomly doped La(1/3)Sr(2/3)MnO3. The antiferromagnetic order is A-type, consisting of in-plane double-exchange-mediated ferromagnetic sheets coupled antiferromagnetically along the out-of-plane direction. Through synchrotron X-ray scattering, we have discovered an in-plane structural modulation that reduces the charge itinerancy and hence the ordering temperature within the ferromagnetic sheets, thereby limiting TN. This modulation is mitigated and driven to long wavelengths by cation ordering, enabling the higher TN values of the superlattices. These results provide insight into how cation-site ordering can enhance cooperative behaviour in oxides through subtle structural phenomena. PMID:19838186

  19. Enhanced ordering temperatures in antiferromagnetic manganite superlattices

    NASA Astrophysics Data System (ADS)

    May, S. J.; Ryan, P. J.; Robertson, J. L.; Kim, J.-W.; Santos, T. S.; Karapetrova, E.; Zarestky, J. L.; Zhai, X.; Te Velthuis, S. G. E.; Eckstein, J. N.; Bader, S. D.; Bhattacharya, A.

    2009-11-01

    The disorder inherent to doping by cation substitution in the complex oxides can have profound effects on collective-ordered states. Here, we demonstrate that cation-site ordering achieved through digital-synthesis techniques can dramatically enhance the antiferromagnetic ordering temperatures of manganite films. Cation-ordered (LaMnO3)m/(SrMnO3)2m superlattices show Néel temperatures (TN) that are the highest of any La1-xSrxMnO3 compound, ~70K greater than compositionally equivalent randomly doped La1/3Sr2/3MnO3. The antiferromagnetic order is A-type, consisting of in-plane double-exchange-mediated ferromagnetic sheets coupled antiferromagnetically along the out-of-plane direction. Through synchrotron X-ray scattering, we have discovered an in-plane structural modulation that reduces the charge itinerancy and hence the ordering temperature within the ferromagnetic sheets, thereby limiting TN. This modulation is mitigated and driven to long wavelengths by cation ordering, enabling the higher TN values of the superlattices. These results provide insight into how cation-site ordering can enhance cooperative behaviour in oxides through subtle structural phenomena.

  20. Enhanced ordering temperatures in antiferromagnetic manganite superlattices

    SciTech Connect

    May, Stephen J. [Argonne National Laboratory (ANL); Robertson, Lee [ORNL; Ryan, P J [Ames Laboratory; Kim, J.-W. [Ames Laboratory; Santos, Tiffany S. [Argonne National Laboratory (ANL); Karapetrova, Evgenia [University of Illinois, Urbana-Champaign; Zarestky, Jerel L. [Ames Laboratory; Zhai, X. [University of Illinois, Urbana-Champaign; Te velthuis, Suzanne G. [Argonne National Laboratory (ANL); Eckstein, James N. [University of Illinois, Urbana-Champaign; Bader, S. D. [Argonne National Laboratory (ANL); Bhattacharya, Anand [Argonne National Laboratory (ANL)

    2009-01-01

    The disorder inherent to doping by cation substitution in the complex oxides can have profound effects on collective ordered states. Here, we demonstrate that cation-site ordering achieved via digital synthesis techniques can dramatically enhance the antiferromagnetic ordering temperatures of manganite films. Cation-ordered (LaMnO3)m/(SrMnO3)2m superlattices exhibit N el temperatures (TN) that are the highest of any La1-xSrxMnO3 compound, ~70 K greater than compositionally equivalent randomly doped La1/3Sr2/3MnO3. The antiferromagnetic order is A-type, consisting of in-plane double-exchange-mediated ferromagnetic sheets coupled antiferromagnetically along the out-of-plane direction. Via synchrotron x-ray scattering, we have discovered an in-plane structural modulation that reduces the charge itinerancy and hence the ordering temperature within the ferromagnetic sheets, thereby limiting TN. This modulation is mitigated and driven to long wavelengths by cation ordering, enabling the higher TN values of the superlattices. These results provide insight into how cation-site ordering can enhance cooperative behavior in oxides through subtle structural phenomena.

  1. Chemical Dosing and First-Order Kinetics

    ERIC Educational Resources Information Center

    Hladky, Paul W.

    2011-01-01

    College students encounter a variety of first-order phenomena in their mathematics and science courses. Introductory chemistry textbooks that discuss first-order processes, usually in conjunction with chemical kinetics or radioactive decay, stop at single, discrete dose events. Although single-dose situations are important, multiple-dose events,…

  2. Propagation Plane waves -High order Modes

    E-print Network

    Berlin,Technische Universität

    1 Propagation · Plane waves - High order Modes y x a One wave: p(x,y,t)=p0 cos(k y)e-jk x e j t vy(y,t)= 0 ; y=0,a xy } ky = n a Propagation · Plane waves - High order Modes x n a p(x,y,t)=pn cos( y

  3. Propagation Plane waves -High order Modes

    E-print Network

    Berlin,Technische Universität

    1 Propagation · Plane waves - High order Modes y x a ky = n a One wave: p(x,y,t)=p0 cos(k y)e-jk x e j t vy(y,t)= 0 ; y=0,a xy } Propagation · Plane waves - High order Modes x n a p(x,y,t)=pn cos( y

  4. Decomposition Orders another generalisation of the fundamental

    E-print Network

    Luttik, Bas

    Decomposition Orders another generalisation of the fundamental theorem of arithmetic Bas Luttik a, The Netherlands Abstract We discuss unique decomposition in partial commutative monoids. Inspired by a result from process theory, we propose the notion of decomposition order for partial commutative monoids, and prove

  5. Experiments on magnetically-ordered superconductors

    NASA Astrophysics Data System (ADS)

    Maple, M. B.

    1983-02-01

    Certain ternary rare earth compounds exhibit long-range magnetic order in the superconducting state. Superconductivity coexists with antiferromagnetic order, but is destroyed by the onset of ferromagnetic order at a second transition temperature Tc2 ? TM, where TM is the Curie temperature. In antiferromagnetic superconductors, the antiferromagnetic order modifies superconducting properties such as the curve of the upper critical magnetic field which exhibits a feature in the vicinity of the Néel temperature. In ferromagnetic superconductors, a long wavelength ( ? 10 2 Å) sinusoidally modulated magnetic state develops in the superconducting state as a result of the superconducting-ferromagnetic interactions. Recent experiments on magnetically-ordered ternary and pseudoternary rare earth superconductors are briefly reviewed.

  6. New Existence Conditions for Order Complementarity Problems

    NASA Astrophysics Data System (ADS)

    Németh, S. Z.

    2009-09-01

    Complementarity problems are mathematical models of problems in economics, engineering and physics. A special class of complementarity problems are the order complementarity problems [2]. Order complementarity problems can be applied in lubrication theory [6] and economics [1]. The notion of exceptional family of elements for general order complementarity problems in Banach spaces will be introduced. It will be shown that for general order complementarity problems defined by completely continuous fields the problem has either a solution or an exceptional family of elements (for other notions of exceptional family of elements see [1, 2, 3, 4] and the related references therein). This solves a conjecture of [2] about the existence of exceptional family of elements for order complementarity problems. The proof can be done by using the Leray-Schauder alternative [5]. An application to integral operators will be given.

  7. Constraints on topological order in mott insulators.

    PubMed

    Zaletel, Michael P; Vishwanath, Ashvin

    2015-02-20

    We point out certain symmetry induced constraints on topological order in Mott insulators (quantum magnets with an odd number of spin 1/2 moments per unit cell). We show, for example, that the double-semion topological order is incompatible with time reversal and translation symmetry in Mott insulators. This sharpens the Hastings-Oshikawa-Lieb-Schultz-Mattis theorem for 2D quantum magnets, which guarantees that a fully symmetric gapped Mott insulator must be topologically ordered, but is silent about which topological order is permitted. Our result applies to the kagome lattice quantum antiferromagnet, where recent numerical calculations of the entanglement entropy indicate a ground state compatible with either toric code or double-semion topological order. Our result rules out the latter possibility. PMID:25763971

  8. Arbitrary order permanent Cartesian multipolar electrostatic interactions

    NASA Astrophysics Data System (ADS)

    Boateng, H. A.; Todorov, I. T.

    2015-01-01

    Recently, there has been a concerted effort to implement advanced classical potential energy surfaces by adding higher order multipoles to fixed point charge electrostatics in a bid to increase the accuracy of simulations of condensed phase systems. One major hurdle is the unwieldy nature of the expressions which in part has limited developers mostly to including only dipoles and quadrupoles. In this paper, we present a generalization of the Cartesian formulation of electrostatic multipolar interactions that enables the specification of an arbitrary order of multipoles. Specifically, we derive formulas for arbitrary order implementation of the particle mesh Ewald method and give a closed form formula for the stress tensor in the reciprocal space. In addition, we provide recurrence relations for common electrostatic potentials employed in molecular simulations, which allows for the generalization to arbitrary order and guarantees a computational cost that scales as O(p3) for Cartesian multipole interactions of order p.

  9. First-order Dyson coordinates and geometry.

    PubMed

    Hermes, Matthew R; Hirata, So

    2013-08-15

    The mathematical constructs of the Dyson coordinates and geometry are introduced. The former are a unitary transformation of the normal coordinates and the anharmonic vibrational counterpart of the Dyson orbitals in electronic structure theory. The first-order Dyson coordinates bring the sums of the harmonic force constants and their first-order diagrammatic perturbation corrections (the first-order Dyson self-energy) to a diagonal form. The first-order Dyson geometry has no counterpart in electronic structure theory. It is the point on the potential energy surface at which the sums of the energy gradients and their first-order diagrammatic perturbation corrections vanish. It agrees with the vibrationally averaged geometry of vibrational self-consistent field (VSCF) theory in the bulk limit. These constructs provide a unified view of the relationship of VSCF and its diagrammatically size-consistent modifications as well as the self-consistent phonon method widely used in solid-state physics. PMID:23577671

  10. Constraints on topological order in Mott Insulators

    E-print Network

    Michael P. Zaletel; Ashvin Vishwanath

    2014-10-10

    We point out certain symmetry induced constraints on topological order in Mott Insulators (quantum magnets with an odd number of spin $\\tfrac{1}{2}$ per unit cell). We show, for example, that the double semion topological order is incompatible with time reversal and translation symmetry in Mott insulators. This sharpens the Hastings-Oshikawa-Lieb-Schultz-Mattis theorem for 2D quantum magnets, which guarantees that a fully symmetric gapped Mott insulator must be topologically ordered, but is silent on which topological order is permitted. An application of our result is the Kagome lattice quantum antiferromagnet where recent numerical calculations of entanglement entropy indicate a ground state compatible with either toric code or double semion topological order. Our result rules out the latter possibility.

  11. On fractional order of an oscillatory system

    NASA Astrophysics Data System (ADS)

    David, S. A.; Valentim, C. A., Jr.

    2013-10-01

    In this paper, we applied the Riemann-Liouville approach and the fractional Euler-Lagrange equations in order to obtain the fractional nonlinear dynamic equations involving the classical physical application "Spring-Mass-Dumper System" to both, integer order calculus (IOC) and fractional order calculus (FOC) approaches. After the numerical simulations, we outlined the main results through time histories and the investigation of phase portraits. Thereafter, we believe that the results showed on this paper are pertinent enough to be thoroughly analyzed and maybe it can be the very beginning of a stride towards more realistic and more precise results about fractional-order models when compared to the integer order models in these applications.

  12. Odd orders in Shor's factoring algorithm

    E-print Network

    Thomas Lawson

    2015-01-13

    Shor's factoring algorithm (SFA) finds the prime factors of a number, $N=p_1 p_2$, exponentially faster than the best known classical algorithm. Responsible for the speed-up is a subroutine called the quantum order finding algorithm (QOFA) which calculates the order -- the smallest integer, $r$, satisfying $a^r \\mod N =1$, where $a$ is a randomly chosen integer coprime to $N$ (meaning their greatest common divisor is one, $\\gcd(a, N) =1$). Given $r$, and with probability not less than $1/2$, the factors are given by $p_1 = \\gcd (a^{\\frac{r}{2}} - 1, N)$ and $p_2 = \\gcd (a^{\\frac{r}{2}} + 1, N)$. For odd $r$ it is assumed the factors cannot be found (since $a^{\\frac{r}{2}}$ is not generally integer) and the QOFA is relaunched with a different value of $a$. But a recent paper [E. Martin-Lopez: Nat Photon {\\bf 6}, 773 (2012)] noted that the factors can sometimes be found from odd orders if the coprime is square. This raises the question of improving SFA's success probability by considering odd orders. We show that an improvement is possible, though it is small. We present two techniques for retrieving the order from apparently useless runs of the QOFA: not discarding odd orders; and looking out for new order finding relations in the case of failure. In terms of efficiency, using our techniques is equivalent to avoiding square coprimes and disregarding odd orders, which is simpler in practice. Even still, our techniques may be useful in the near future, while demonstrations are restricted to factoring small numbers. The most convincing demonstrations of the QOFA are those that return a non-power-of-two order, making odd orders that lead to the factors attractive to experimentalists.

  13. Enhancement of Nematic Order and Global Phase Diagram of a Lattice Model for Coupled Nematic Systems

    NASA Astrophysics Data System (ADS)

    Liarte, Danilo Barbosa; Salinas, Silvio Roberto

    2012-08-01

    We use an infinite-range Maier-Saupe model, with two sets of local quadrupolar variables and restricted orientations, to investigate the global phase diagram of a coupled system of two nematic subsystems. The free energy and the equations of state are exactly calculated by standard techniques of statistical mechanics. The nematic-isotropic transition temperature of system A increases with both the interaction energy among mesogens of system B, and the two-subsystem coupling J. This enhancement of the nematic phase is manifested in a global phase diagram in terms of the interaction parameters and the temperature T. We make some comments on the connections of these results with experimental findings for a system of diluted ferroelectric nanoparticles embedded in a nematic liquid-crystalline environment.

  14. Collective character of spin excitations in a system of Mn2+ spins coupled to a two-dimensional electron gas.

    PubMed

    Teran, F J; Potemski, M; Maude, D K; Plantier, D; Hassan, A K; Sachrajda, A; Wilamowski, Z; Jaroszynski, J; Wojtowicz, T; Karczewski, G

    2003-08-15

    We have studied the low energy spin excitations in n-type CdMnTe based dilute magnetic semiconductor quantum wells. For magnetic fields for which the energies for the excitation of free carriers and Mn spins are almost identical, an anomalously large Knight shift is observed. Our findings suggest the existence of a magnetic-field-induced ferromagnetic order in these structures, which is in agreement with recent theoretical predictions [Phys. Rev. Lett. 91, 077202 (2003)

  15. Martensitic transformation in Fe-based shape memory alloys under magnetic field

    Microsoft Academic Search

    T. Kakeshita; T. Fukuda; T. Terai; T. Takeuchi; K. Kishio

    2003-01-01

    Effects of magnetic field on martensitic transformations have been examined in order to know a magnetic field-induced martensitic transformation by using Fe3Pt and Fe-Ni-Co-Ti shape memory alloys and an Fe-Ni alloy polycrystals, and control of variants by magnetic field by using Fe-Pd, Ni2MnGa and Fe3Pt shape memory alloy single crystals. Following results were obtained: (i) The effects of magnetic field

  16. Dimensional crossover in a spin liquid to helimagnet quantum phase transition.

    SciTech Connect

    Garlea, Vasile O [ORNL; Zheludev, Andrey I [ORNL; Habicht, Klaus [Hahn-Meitner Institut, Berlin, Germany; Meissner, Michael [Hahn-Meitner Institut, Berlin, Germany; Grenier, B. [CEA, Grenoble, France; Regnault, L.-P. [CEA, Grenoble, France; Ressouche, E. [CEA, Grenoble, France

    2009-01-01

    Neutron scattering is used to study magnetic field induced ordering in the quasi-1D quantum spin-tube compound Sul-Cu2Cl4 that in zero field has a non-magnetic spin-liquid ground state. The experiments reveal an incommensurate chiral high-field phase stabilized by a geometric frustration of the magnetic interactions. The measured critical exponents \\beta= 0.235 and \

  17. Magnetic field enhancement of non-local spin signal in Ni{<_80}Fe{<_20}/Ag lateral spin valves.

    SciTech Connect

    Mihajlovic, G.; Erlingsson, S. I.; Vyborny, K.; Pearson, J. E.; Bader, S. D.; Hoffmann, A. (Center for Nanoscale Materials); ( MSD); (Hitachi Global Storage Tech.); (Reykjavik Univ.); (Acad. Sci. Czech Republic)

    2011-01-01

    We observe a magnetic-field-induced enhancement of the nonlocal spin signal in Ni{sub 80}Fe{sub 20}/Ag lateral spin valves. The enhancement depends on the bias current polarity but not on the field direction. We present a theoretical model that explains our experimental results, taking into account the electron-spin relaxation of magnetic impurities. We find that the relaxation is about an order of magnitude weaker than Elliott-Yafet relaxation.

  18. Fourth order difference methods for hyperbolic IBVP's

    NASA Technical Reports Server (NTRS)

    Gustafsson, Bertil; Olsson, Pelle

    1994-01-01

    Fourth order difference approximations of initial-boundary value problems for hyperbolic partial differential equations are considered. We use the method of lines approach with both explicit and compact implicit difference operators in space. The explicit operator satisfies an energy estimate leading to strict stability. For the implicit operator we develop boundary conditions and give a complete proof of strong stability using the Laplace transform technique. We also present numerical experiments for the linear advection equation and Burgers' equation with discontinuities in the solution or in its derivative. The first equation is used for modeling contact discontinuities in fluid dynamics, the second one for modeling shocks and rarefaction waves. The time discretization is done with a third order Runge-Kutta TVD method. For solutions with discontinuities in the solution itself we add a filter based on second order viscosity. In case of the non-linear Burger's equation we use a flux splitting technique that results in an energy estimate for certain different approximations, in which case also an entropy condition is fulfilled. In particular we shall demonstrate that the unsplit conservative form produces a non-physical shock instead of the physically correct rarefaction wave. In the numerical experiments we compare our fourth order methods with a standard second order one and with a third order TVD-method. The results show that the fourth order methods are the only ones that give good results for all the considered test problems.

  19. Order Metrics for Semantic Knowledge Systems

    NASA Astrophysics Data System (ADS)

    Joslyn, Cliff; Hogan, Emilie

    Knowledge systems technologies, as derived from AI methods and used in the modern Semantic Web movement, are dominated by graphical knowledge structures such as ontologies and semantic graph databases. A critical but typically overlooked aspect of all of these structures is their admission to analyses in terms of formal hierarchical relations. The partial order representations of whatever hierarchy is present within a knowledge structure afford opportunities to exploit these hierarchical constraints to facilitate a variety of tasks, including ontology analysis and alignment, visual layout, and anomaly detection. We introduce the basic concepts of order metrics and address the impact of a hierarchical (order-theoretical) analysis on knowledge systems tasks.

  20. Benchmarking ordering techniques for nonserial dynamic programming

    E-print Network

    Sviridenko, Alexander

    2011-01-01

    Five ordering algorithms for the nonserial dynamic programming algorithm for solving sparse discrete optimization problems are compared in this paper. The benchmarking reveals that the ordering of the variables has a significant impact on the run-time of these algorithms. In addition, it is shown that different orderings are most effective for different classes of problems. Finally, it is shown that, amongst the algorithms considered here, heuristics based on maximum cardinality search and minimum fill-in perform best for solving the discrete optimization problems considered in this paper.

  1. Thermal conductivity of ordered molecular water.

    PubMed

    Evans, William; Fish, Jacob; Keblinski, Pawel

    2007-04-21

    The authors use molecular dynamics simulation to investigate the thermal transport characteristics of water with various degree of orientational and translational orders induced by the application of an electric field. The authors observe that the orientational ordering of the water dipole moments has a minor effect on the thermal conductivity. However, electric-field-induced crystallization and associated translational order result in approximately a three fold increase of thermal conductivity with respect to the base water, i.e., to values comparable with those characterizing ice crystal structures. PMID:17461644

  2. Roughness in Lattice Ordered Effect Algebras

    PubMed Central

    Xin, Xiao Long; Hua, Xiu Juan; Zhu, Xi

    2014-01-01

    Many authors have studied roughness on various algebraic systems. In this paper, we consider a lattice ordered effect algebra and discuss its roughness in this context. Moreover, we introduce the notions of the interior and the closure of a subset and give some of their properties in effect algebras. Finally, we use a Riesz ideal induced congruence and define a function e(a, b) in a lattice ordered effect algebra E and build a relationship between it and congruence classes. Then we study some properties about approximation of lattice ordered effect algebras. PMID:25170523

  3. 5 Dice: Order of Operations Game

    NSDL National Science Digital Library

    Josh Holladay

    2013-01-31

    This math app intended for upper elementary students using the addition and subtraction level and middle school students using all four operations helps players practice their order of operations. This interactive game encourages students to use higher order thinking to use the five numbers and given operations to solve the "target" number by working backwards given the answer but not the equation. The best feature about this math game is that teachers are able to receive immediate feedback of their students’ progress through email. Students do not have to provide an email address in order to play.

  4. Make Your Own (Order of Operations)

    NSDL National Science Digital Library

    2010-01-01

    To give them practice with order of operations, students make up and solve their own order of operations problems. This activity can be done two ways. 1. Students get into groups of two or three and make up about 3 different type of order of operations problems and then solve each of them. 2. Each student finds a partner, creates their own question, and trades it with their partner for them to try. Then they grade each other's work. Either way, they get extra practice, hopefully catch their mistakes with some help from another student, and take a more active approach to problem solving.

  5. Thermal Conductivity of Ordered Molecular Water

    SciTech Connect

    W Evans; J Fish; P Keblinski

    2006-02-16

    We use molecular dynamics simulation to investigate thermal transport characteristics of water with various degree of orientational and translational order induced by the application of an electric field. We observe that orientational ordering of the water dipole moments has a minor effect on the thermal conductivity. However, electric-field induced crystallization and associated translational order results in approximately a 3-fold increase of thermal conductivity with respect to the base water, i.e., to values comparable with those characterizing ice crystal structures.

  6. 50 CFR 300.97 - Inseason orders.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...INTERNATIONAL FISHERIES REGULATIONS Fraser River Sockeye and Pink Salmon Fisheries § 300.97 Inseason orders. (a) During...procedures section of the annual management measures for West Coast Salmon Fisheries, published in the Federal Register ; Treaty...

  7. 50 CFR 300.97 - Inseason orders.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...INTERNATIONAL FISHERIES REGULATIONS Fraser River Sockeye and Pink Salmon Fisheries § 300.97 Inseason orders. (a) During...procedures section of the annual management measures for West Coast Salmon Fisheries, published in the Federal Register ; Treaty...

  8. 50 CFR 300.97 - Inseason orders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...INTERNATIONAL FISHERIES REGULATIONS Fraser River Sockeye and Pink Salmon Fisheries § 300.97 Inseason orders. (a) During...procedures section of the annual management measures for West Coast Salmon Fisheries, published in the Federal Register ; Treaty...

  9. 50 CFR 300.97 - Inseason orders.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...INTERNATIONAL FISHERIES REGULATIONS Fraser River Sockeye and Pink Salmon Fisheries § 300.97 Inseason orders. (a) During...procedures section of the annual management measures for West Coast Salmon Fisheries, published in the Federal Register ; Treaty...

  10. 50 CFR 300.97 - Inseason orders.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...INTERNATIONAL FISHERIES REGULATIONS Fraser River Sockeye and Pink Salmon Fisheries § 300.97 Inseason orders. (a) During...procedures section of the annual management measures for West Coast Salmon Fisheries, published in the Federal Register ; Treaty...

  11. Higher order intertwining approach to quasinormal modes

    E-print Network

    T. Jana; P. Roy

    2007-05-23

    Using higher order intertwining operators we obtain new exactly solvable potentials admitting quasinormal mode (QNMs) solutions of the Klein-Gordon equation. It is also shown that different potentials exhibiting QNMs can be related through nonlinear supersymmetry.

  12. High-Order Energy Stable WENO Schemes

    NASA Technical Reports Server (NTRS)

    Yamaleev, Nail K.; Carpenter, Mark H.

    2009-01-01

    A third-order Energy Stable Weighted Essentially Non-Oscillatory (ESWENO) finite difference scheme developed by Yamaleev and Carpenter was proven to be stable in the energy norm for both continuous and discontinuous solutions of systems of linear hyperbolic equations. Herein, a systematic approach is presented that enables 'energy stable' modifications for existing WENO schemes of any order. The technique is demonstrated by developing a one-parameter family of fifth-order upwind-biased ESWENO schemes; ESWENO schemes up to eighth order are presented in the appendix. New weight functions are also developed that provide (1) formal consistency, (2) much faster convergence for smooth solutions with an arbitrary number of vanishing derivatives, and (3) improved resolution near strong discontinuities.

  13. Petroleum: The Petroleum (Liquid Methane) Order, 1957 

    E-print Network

    Agnew, W.G.

    1957-01-01

    This Order applies to liquid methane the provisions of the Petroleum (Consolidation) Act, 1928, except those which are inappropriate; in particular provisions appropriate only in the case of fuel for vehicles are not ...

  14. 46 CFR 5.567 - Order.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...admonition, suspension with or without probation, or revocation . (b...for a specified period, but placed on probation for a specific period; or (4) Suspended...by a specified period of suspension on probation. (d) The order will normally...

  15. 40 CFR 91.604 - Test orders.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...FROM MARINE SPARK-IGNITION ENGINES Selective Enforcement Auditing Regulations § 91.604 Test orders. (a) A test...certification submitted by the manufacturer, pursuant to the requirements of the applicable section of subpart B of this part....

  16. 47 CFR 54.511 - Ordering services.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...SERVICE Universal Service Support for Schools and Libraries § 54.511 Ordering services. (a) Selecting...selecting a provider of eligible services, schools, libraries, library consortia, and consortia including any...

  17. 47 CFR 54.511 - Ordering services.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...SERVICE Universal Service Support for Schools and Libraries § 54.511 Ordering services. (a) Selecting...selecting a provider of eligible services, schools, libraries, library consortia, and consortia including any...

  18. 47 CFR 54.511 - Ordering services.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...SERVICE Universal Service Support for Schools and Libraries § 54.511 Ordering services. (a) Selecting...selecting a provider of eligible services, schools, libraries, library consortia, and consortia including any...

  19. 47 CFR 54.511 - Ordering services.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...SERVICE Universal Service Support for Schools and Libraries § 54.511 Ordering services. (a) Selecting...selecting a provider of eligible services, schools, libraries, library consortia, and consortia including any...

  20. 33 CFR 156.112 - Suspension order.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...POLLUTION OIL AND HAZARDOUS MATERIAL TRANSFER OPERATIONS Oil and Hazardous Material Transfer Operations § 156.112 Suspension...issue a suspension order to suspend transfer operations to the vessel or facility operator when the COTP or OCMI...