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1

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

SciTech Connect

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.

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

2

A real space description of magnetic field induced melting in the charge ordered manganites: II. The disordered case  

NASA Astrophysics Data System (ADS)

We study the effect of A site disorder on magnetic field induced melting of charge order (CO) in half doped manganites using a Monte-Carlo technique. Strong A-site disorder destroys CO even without an applied field. At moderate disorder, the zero field CO state survives but has several intriguing features in its field response. Our spatially resolved results track the broadening of the field melting transition due to disorder and explain the unusual dependence of the melting scales on bandwidth and disorder. In combination with our companion paper on field melting of charge order in clean systems we provide an unified understanding of CO melting across all half doped manganites.

Mukherjee, Anamitra; Majumdar, Pinaki

2014-10-01

3

Antiferroquadrupolar ordering and magnetic-field-induced phase transition in the cage compound PrRh2Zn20  

NASA Astrophysics Data System (ADS)

To investigate the origin of a phase transition at TQ=0.06 K simultaneously occurring with a superconducting transition in a cage compound PrRh2Zn20, we carried out ultrasonic measurements on a single-crystalline sample. The transverse modulus (C11-C12)/2 is intimately coupled to the non-Kramers ground doublet ?3, and elastic softening is observed at low temperatures. Below TQ, the softening stops, suggesting the disappearance of quadrupole degrees of freedom. We clarified the negative quadrupole-quadrupole coupling constant and reentrant behavior of TQ(H) in a magnetic field H. These results reveal that the phase transition at TQ is antiferroquadrupolar ordering. The anisotropic magnetic field-temperature phase diagram is determined for H?[100], [110], and [111]. A magnetic-field-induced phase transition is newly found at high fields in all three field directions. We also observed ultrasonic dispersion at around 50 K owing to the rattling motion of Zn atoms at the 16c site, and pointed out the strong electron-phonon coupling in PrRh2Zn20.

Ishii, Isao; Muneshige, Hitoshi; Kamikawa, Shuhei; Fujita, Takahiro K.; Onimaru, Takahiro; Nagasawa, Naohiro; Takabatake, Toshiro; Suzuki, Takashi; Ano, Genki; Akatsu, Mitsuhiro; Nemoto, Yuichi; Goto, Terutaka

2013-05-01

4

Orientational microdynamics and magnetic-field-induced ordering of clay platelets detected by 2H NMR spectroscopy.  

PubMed

The orientation of montmorillonite clays induced by a static magnetic field is quantified by using (2)H NMR spectroscopy. Indeed, the residual quadrupolar splitting of the (2)H resonance line measured for heavy water is a direct consequence of the specific orientation of the clay platelets in the static magnetic field. In the dilute regime, this residual splitting increases linearly with clay concentration, which confirms that the clay/clay electrostatic repulsions remain negligible by comparison with the diamagnetic coupling of these anisotropic platelets. At higher concentration, the electrostatic repulsion between clay particles markedly enhances the detected splitting. Such enhancement is well predicted by numerical simulations. By varying the size of the clay platelets and the strength of the static magnetic field, it is possible to evaluate the order of magnitude of the diamagnetic susceptibility of these anisotropic colloids. PMID:20047274

Porion, Patrice; Faugère, Anne Marie; Michot, Laurent J; Paineau, Erwan; Delville, Alfred

2010-05-18

5

Magnetic field induced third order susceptibility of third order harmonic generation in a ZnMgSe strained quantum well  

NASA Astrophysics Data System (ADS)

Third order susceptibility of third order harmonic generation is investigated in a Zn0.1Mg0.9Se/Zn0.8Mg0.2Se/Zn0.1Mg0.9Se quantum well in the presence of magnetic field strength. The confinement potential is considered as the addition of energy offsets of the conduction band (or valence band) and the strain-induced potential in our calculations. The material dependent effective mass is followed throughout the computation because it has a high influence on the electron energy levels in low dimensional semiconductor systems.

Mark, J. Abraham Hudson; Peter, A. John

2014-04-01

6

Stability of magnetic field-induced dipolar order in a ferroelectric side-chain liquid crystal polymer  

Microsoft Academic Search

The stability of in-layer dipolar order in a side-chain ferroelectric liquid crystalline polymer has been investigated by probing the optical birefringence produced by aligning the mesogenic side groups with a high magnetic field. The temperature dependence of the decay time associated with the mesogen relaxation from a state of saturated alignment obeys an Arrhenius law, with an activation energy two

S. Sprunt; G. Nounesis; J. Naciri; B. R. Ratna; R. Shashidhar

1994-01-01

7

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

NASA Astrophysics Data System (ADS)

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.

Mukherjee, Anamitra; Majumdar, Pinaki

2014-10-01

8

Shear- and magnetic-field-induced ordering in magnetic nanoparticle dispersion from small-angle neutron scattering.  

PubMed

Small-angle neutron scattering experiments have been performed to investigate orientational ordering of a dispersion of rod-shaped ferromagnetic nanoparticles under the influence of shear flow and static magnetic field. In this experiment, the flow and flow gradient directions are perpendicular to the direction of the applied magnetic field. The scattering intensity is isotropic in zero-shear-rate or zero-applied-field conditions, indicating that the particles are randomly oriented. Anisotropic scattering is observed both in a shear flow and in a static magnetic field, showing that both flow and field induce orientational order in the dispersion. The anisotropy increases with the increase of field and with the increase of shear rate. Three states of order have been observed with the application of both shear flow and magnetic field. At low shear rates, the particles are aligned in the field direction. When increasing shear rate is applied, the particles revert to random orientations at a characteristic shear rate that depends on the strength of the applied magnetic field. Above the characteristic shear rate, the particles align along the flow direction. The experimental results agree qualitatively with the predictions of a mean field model. PMID:12786151

Krishnamurthy, V V; Bhandar, A S; Piao, M; Zoto, I; Lane, A M; Nikles, D E; Wiest, J M; Mankey, G J; Porcar, L; Glinka, C J

2003-05-01

9

Magnetic field induced dynamical chaos  

SciTech Connect

In this article, we have studied the dynamics of a particle having charge in the presence of a magnetic field. The motion of the particle is confined in the x–y plane under a two dimensional nonlinear potential. We have shown that constant magnetic field induced dynamical chaos is possible even for a force which is derived from a simple potential. For a given strength of the magnetic field, initial position, and velocity of the particle, the dynamics may be regular, but it may become chaotic when the field is time dependent. Chaotic dynamics is very often if the field is time dependent. Origin of chaos has been explored using the Hamiltonian function of the dynamics in terms of action and angle variables. Applicability of the present study has been discussed with a few examples.

Ray, Somrita; Baura, Alendu; Bag, Bidhan Chandra, E-mail: bidhanchandra.bag@visva-bharati.ac.in [Department of Chemistry, Visva-Bharati, Santiniketan 731 235 (India)

2013-12-15

10

Magnetic-field-induced charge order in the filled skutterudite SmRu4P12: Evidence from resonant and nonresonant x-ray diffraction  

NASA Astrophysics Data System (ADS)

The antiferromagnetic ordered phase in SmRu4P12 below the metal-insulator transition at TMI=16.5 K with an unresolved transition at T*˜14 K has been studied by resonant and nonresonant x-ray diffraction in magnetic fields. In the intermediate phase, a nonresonant Thomson scattering with q =(1,0,0) is induced by applying a magnetic field, which is presumably caused by atomic displacements reflecting the charge order in the p band, as predicted theoretically [R. Shiina, J. Phys. Soc. Jpn. 82, 083713 (2013), 10.7566/JPSJ.82.083713]. Simultaneously, the antiferromagnetic moment of Sm is enhanced along the field direction, which is considered to reflect the staggered ordering of the ?7-?8 crystal-field states (scalar or hexadecapole order). The present results show that the orbital-dependent p-f hybridization in association with the nesting instability in the p band gives rise to the unconventional charge order similarly with PrRu4P12 and PrFe4P12.

Matsumura, Takeshi; Michimura, Shinji; Inami, Toshiya; Hayashi, Yuya; Fushiya, Kengo; Matsuda, Tatsuma D.; Higashinaka, Ryuji; Aoki, Yuji; Sugawara, Hitoshi

2014-04-01

11

Magnetic-Field-Induced Electric Polarization in Multiferroic Nanostructures  

Microsoft Academic Search

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

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

2005-01-01

12

External power frequency magnetic field-induced jitter on computer monitors  

Microsoft Academic Search

Power frequency magnetic fields with flux densities greater than 0.5 ?T are not uncommon in offices. This level has been shown to induce jitter on VDT monitors. In the present project, these magnetic field-induced disturbances have been studied in the laboratory in order to establish a firm technical basis for future studies of the disturbance's influence on eye strain in

MONICA SANDSTRÖM; KJELL HANSSON MILD; MATTIAS SANDSTRÖM; ANDRÉ BERGLUND

1993-01-01

13

Separation of isotropic chemical and second-order quadrupolar shifts by multiple-quantum double rotation NMR  

NASA Astrophysics Data System (ADS)

Using a two-dimensional multiple-quantum (MQ) double rotation (DOR) experiment the contributions of the chemical shift and quadrupolar interaction to isotropic resonance shifts can be completely separated. Spectra were acquired using a three-pulse triple-quantum z-filtered pulse sequence and subsequently sheared along both the ?1 and ?2 dimensions. The application of this method is demonstrated for both crystalline (RbNO 3) and amorphous samples (vitreous B 2O 3). The existence of the two rubidium isotopes ( 85Rb and 87Rb) allows comparison of results for two nuclei with different spins ( I = 3/2 and 5/2), as well as different dipole and quadrupole moments in a single chemical compound. Being only limited by homogeneous line broadening and sample crystallinity, linewidths of approximately 0.1 and 0.2 ppm can be measured for 87Rb in the quadrupolar and chemical shift dimensions, enabling highly accurate determination of the isotropic chemical shift and the quadrupolar product, P Q. For vitreous B 2O 3, the use of MQDOR allows the chemical shift and electric field gradient distributions to be directly determined—information that is difficult to obtain otherwise due to the presence of second-order quadrupolar broadening.

Hung, Ivan; Wong, Alan; Howes, Andy P.; Anupõld, Tiit; Samoson, Ago; Smith, Mark E.; Holland, Diane; Brown, Steven P.; Dupree, Ray

2009-04-01

14

Magnetic field induced transition in vanadium spinels.  

PubMed

We study vanadium spinels AV2O4 (A = Cd,Mg) in pulsed magnetic fields up to 65 T. A jump in magnetization at ?0H?40??T is observed in the single-crystal MgV2O4, indicating a field induced quantum phase transition between two distinct magnetic orders. In the multiferroic CdV2O4, the field induced transition is accompanied by a suppression of the electric polarization. By modeling the magnetic properties in the presence of strong spin-orbit coupling characteristic of vanadium spinels, we show that both features of the field induced transition can be successfully explained by including the effects of the local trigonal crystal field. PMID:24483929

Mun, E D; Chern, Gia-Wei; Pardo, V; Rivadulla, F; Sinclair, R; Zhou, H D; Zapf, V S; Batista, C D

2014-01-10

15

Magnetic-Field Induced Quantum Phase Transitions in Triangular-Lattice Antiferromagnets  

E-print Network

Magnetic-Field Induced Quantum Phase Transitions in Triangular-Lattice Antiferromagnets T Ono1, H Department of Physics, Smith College, Northampton, Massachusetts 01063, USA 5 National High Magnetic Field a spatially anisotropic triangular lattice, successive magnetic-field induced quantum phase transitions

McQuade, D. Tyler

16

Impurities in magnetic-field-induced Luttinger liquid  

NASA Astrophysics Data System (ADS)

It has been shown recently(C. Biagini, D. L. Maslov, M. Yu. Reizer and L. I. Glazman, `` Magnetic-field-induced Luttinger liquid''), cond-mat/0006407. that a strong magnetic field applied to a bulk metal may induce a Luttinger liquid phase. This is a consequence of the reduced effective dimensionality of charge carriers from 3D to 1D, an effect which is most pronounced in the ultra-quantum limit, when only the lowest Landau level remains populated. We study the effect of impurities in this system. For the case of a point impurity, the calculation of the scattering cross section at a single impurity can be mapped exactly to a 1D problem of tunneling conductance through a barrier for interacting electrons, solved by Yue et al.(D. Yue, L. I. Glazman and K. A. Matveev, Phys. Rev. B 49) (1994) 1966.. Using this mapping, we find that the longitudinal (?=+1) and transverse (?=-1) Drude conductivities exhibit the scaling laws ?_?? T^??, where ?=2e^2|ln?l_B|/? v_F, and vF and ? are the B-dependent Fermi velocity and screening wavevector, respectively; lB is the magnetic length. The physical reason for such a behavior of the conductivity is the almost 1D form of the Friedel oscillation around a single point impurity in the strong magnetic field.

Tsai, Shan-Wen; Maslov, Dmitrii L.; Glazman, Leonid I.

2001-03-01

17

Nematic ordering of suspension of charged anisotropic colloids detected by multinuclear quadrupolar spectra and 1H PGSE-NMR measurements.  

PubMed

The structure of aqueous dispersion of charged anisotropic nano-composites (synthetic Laponite clays) have been studied by NMR and numerical simulations based on a multi-scale statistical analysis have been used to interpret the mobility of the confined water molecule diffusing within dense Laponite aqueous dispersions (29-52% w/w) prepared by uniaxial compression. Firstly, the lineshape detected by NMR quadrupolar spectroscopy of the counterions ((23)Na or (7)Li) exhibits a large residual splitting Delta nu which is the fingerprint of the macroscopic nematic ordering of the anisotropic particles. Secondly, these results are also confirmed by the anisotropy of the self-diffusion tensor of the water molecule measured by (1)H Pulsed Gradient Spin Echo NMR. This self-diffusion anisotropy increases with the suspension density. Thirdly, the multi-scale statistical analysis of the water mobility bridges the gap between the time-scale (ps) accessible by Molecular Dynamics simulations and the time-scale (micros) accessible by Brownian Dynamics, leading to macroscopic behaviour comparable with PGSE-NMR data measurements. PMID:15011007

Porion, P; Al-Mukhtar, M; Faugère, A-M; Meyer, S; Delville, A

2003-11-01

18

Magnetic-field-induced ferroelectric polarization reversal in the multiferroic Ge(1-x)Mn(x)Te semiconductor.  

PubMed

Ge(1-x)Mn(x)Te is shown to be a multiferroic semiconductor, exhibiting both ferromagnetic and ferroelectric properties. By ferromagnetic resonance we demonstrate that both types of order are coupled to each other. As a result, magnetic-field-induced ferroelectric polarization reversal is achieved. Switching of the spontaneous electric dipole moment is monitored by changes in the magnetocrystalline anisotropy. This also reveals that the ferroelectric polarization reversal is accompanied by a reorientation of the hard and easy magnetization axes. By tuning the GeMnTe composition, the interplay between ferromagnetism and ferroelectricity can be controlled. PMID:24580486

Przybyli?ska, H; Springholz, G; Lechner, R T; Hassan, M; Wegscheider, M; Jantsch, W; Bauer, G

2014-01-31

19

Effects of hole doping by neutron irradiation of magnetic field induced electronic phase transitions in graphite  

SciTech Connect

We have investigated effects of hole doping by fast-neutron irradiation on the magnetic-field induced phase transitions in graphite using specimens irradiated with fast neutrons. Resistance measurements have been done in magnetic fields of up to above 50 T and at temperatures down to about 1.5 K. The neutron irradiation creates lattice defects acting as acceptors, affecting the imbalance of the electron and hole densities and the Fermi level. We have found that the reentrant field from the field induced state back to the normal state shifts towards a lower field with hole doping, suggestive of the participation of electron subbands in the magnetic-field induced state.

Singleton, John [Los Alamos National Laboratory; Yaguchi, Hiroshi [TOKYO UNIV

2008-01-01

20

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

E-print Network

Magnetic-field-induced crystallographic texture enhancement in cold-deformed FePt nanostructured magnets B. Z. Cuia and K. Han National High Magnetic Field Laboratory, Florida State University Grenoble, France H. J. Schneider-Muntau National High Magnetic Field Laboratory, Florida State University

Garmestani, Hamid

21

Nanoengineered Magnetic-Field-Induced Superconductivity Martin Lange,* Margriet J. Van Bael, Yvan Bruynseraede, and Victor V. Moshchalkov  

E-print Network

Nanoengineered Magnetic-Field-Induced Superconductivity Martin Lange,* Margriet J. Van Bael, Yvan a nanoengineered lattice of magnetic dots (dipoles) on top of the film. Magnetic-field-induced super- conductivity between the dots by the stray field of the dipole array. By switching between different magnetic states

Moshchalkov, Victor V.

22

Magnetic-field-induced phases in anisotropic triangular antiferromagnets: Application to CuCrO2  

NASA Astrophysics Data System (ADS)

We introduce a minimal spin model for describing the magnetic properties of CuCrO2. Our Monte Carlo simulations of this model reveal a rich magnetic-field-induced phase diagram, which explains the measured field dependence of the electric polarization. The sequence of phase transitions between different multiferroic states arises from a subtle interplay between spatial and spin anisotropy, magnetic frustration, and thermal fluctuations. Our calculations are compared to new measurements up to 92 T.

Lin, Shi-Zeng; Barros, Kipton; Mun, Eundeok; Kim, Jae-Wook; Frontzek, Matthias; Barilo, S.; Shiryaev, S. V.; Zapf, Vivien S.; Batista, Cristian D.

2014-06-01

23

Electron correlations in semiconductors: Bulk cohesive properties and magnetic-field-induced Wigner crystal at heterojunctions  

SciTech Connect

A correlated wavefunction variational quantum Monte Carlo approach to the studies of electron exchange and correlation effects in semiconductors is presented. Applications discussed include the cohesive and structural properties of bulk semiconductors, and the magnetic-field-induced Wigner electron crystal in two dimensions. Landau level mixing is shown to be important in determining the transition between the quantum Hall liquid and the Wigner crystal states in the regime of relevant experimental parameters.

Louie, S.G.; Zhu, X.

1992-08-01

24

Magnetic-Field-Induced Delocalized to Localized Transformation in GaAs:N  

NASA Astrophysics Data System (ADS)

The use of a high magnetic field (57 T) to study the formation and evolution of nitrogen (N) cluster and supercluster states in GaAs:N is demonstrated. A magnetic field is used to lift the conduction band edge and expose resonant N cluster states so that they can be directly experimentally investigated. The reduction of the exciton Bohr radius also results in the fragmentation of N supercluster states, enabling a magnetic field induced delocalized to localized transition. The application of very high magnetic fields thus presents a powerful way to probe percolation phenomena in semiconductors with bound and resonant isoelectronic cluster states.

Alberi, K.; Crooker, S. A.; Fluegel, B.; Beaton, D. A.; Ptak, A. J.; Mascarenhas, A.

2013-04-01

25

Magnetic field induced quantum phase transitions in the two-impurity Anderson model  

SciTech Connect

In the two-impurity Anderson model, the inter-impurity spin exchange interaction favors a spin singlet state between two impurities leading to the localization of quasiparticles. We show that a local uniform magnetic field can delocalize the quasiparticies to restore the Kondo resonance. This transition is found to be continuous, accompanied by not only the divergence of the staggered (anti ferromagnetic) susceptibility, but also the divergence of the uniform spin susceptibility. This implies that the magnetic field induced quantum phase transitions in Kondo systems are in favor of the local critical type.

Zhu, Lujun [Los Alamos National Laboratory; Zhu, Jian - Xin [Los Alamos National Laboratory

2010-11-17

26

The modelling of the toroidal magnetic field induced by tidal ocean circulation  

NASA Astrophysics Data System (ADS)

Observations of the ocean-induced magnetic field by the CHAMP magnetic space mission have the potential to be used as a constraint when examining ocean dynamics. This has initiated theoretical studies on the prediction of the poloidal magnetic field induced by the horizontal ocean-circulation flow. This study deals with the computation and analysis of the toroidal magnetic field induced by the tidal ocean-circulation flow on the background of the main Earth's geomagnetic field. Since the induced toroidal magnetic field cannot be modelled by the single-layer approximation model used to predict the poloidal magnetic field, we treat the ocean as a spherical layer of a finite thickness and compute the toroidal magnetic field by a matrix-propagator technique with a source of electric currents in the ocean layer. Our numerical simulations based on the OMCT tidal ocean velocities show that the induced toroidal magnetic field is extremely sensitive to the vertical gradient of horizontal ocean flow. The larger this gradient, the stronger the induced toroidal magnetic field. Specifically, its magnitudes vary from 10-2 nT for barotropic flow to several nT for baroclinic flow. We show that the induced toroidal magnetic field generated by M2 tidal forcing is comparable in amplitude to the induced poloidal part of the field. The induced toroidal and poloidal magnetic fields differ, however, in their spatial behaviour.

Dostal, Jan; Martinec, Zden?k.; Thomas, Maik

2012-05-01

27

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

E-print Network

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.

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

2010-03-10

28

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

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

29

Model of Magnetic Field Induced Mitotic Apparatus Reorientation in Frog Eggs  

NASA Astrophysics Data System (ADS)

Studies of the response of living systems to symmetry breaking, uniform physical fields (i.e. electric, gravitational, and magnetic) have yielded novel insight into a variety of biological processes. Recent experiments have shown that intense static magnetic fields alter the geometry of the early cell cleavages of Xenopus laevis eggs^2. The changes depend on field orientation, strength and timing. We present a model that qualitatively accounts for these effects which presumes that 1) the structures involved in cell division are cylindrically symmetric and diamagnetically anisotropic and 2) the geometry of the centrosome replication and spreading processes dictates the nominal cleavage geometry. Within this model, the altered cleavage geometry results from the magnetic field induced realignment of mitotic structures, which causes a realignment of the centrosome replication and spreading processes^3. ^2 J. M. Valles, Jr. et al., Expt. Cell. Res. (under revision). ^3 J. M. Valles, Jr., Biophys. J. (under revision).

Valles, , Jr.

2002-03-01

30

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

NASA Astrophysics Data System (ADS)

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.

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

2014-06-01

31

Magnetic field-induced martensitic phase transformation in magnetic shape memory alloys: Modeling and experiments  

NASA Astrophysics Data System (ADS)

In this work, a continuum based model of the magnetic field induced phase transformation (FIPT) for magnetic shape memory alloys (MSMA) is developed. Hysteretic material behaviors are considered through the introduction of internal state variables. A Gibbs free energy is proposed using group invariant theory and the coupled constitutive equations are derived in a thermodynamically consistent way. An experimental procedure of FIPT in NiMnCoIn MSMA single crystals, which can operate under high blocking stress, is described. The model is then reduced to a 1-D form and the material parameter identification from the experimental results is discussed. Model predictions of magneto-thermo-mechanical loading conditions are presented and compared to experiments.

Haldar, Krishnendu; Lagoudas, Dimitris C.; Karaman, Ibrahim

2014-09-01

32

Magnetic field induced dielectric relaxation in the strain glass state of Pr0.6Ca0.4MnO3  

NASA Astrophysics Data System (ADS)

We present the dielectric and magnetodielectric properties of Pr0.6Ca0.4MnO3 polycrystalline sample. Dielectric permittivity (?') (and d?'/dT) portrays the charge order and other magnetic transitions observed in the magnetization measurement. Dielectric study has revealed a relaxation corresponding to ordering of polarons at ˜60 K that follows Arrhenius behavior both in the presence and absence of magnetic field, and another relaxation was noticed at ˜30 K only under a critical magnetic field (3.2 T) that shows critical slow down of electronic charges obeying power law. Further, the magnetic field induced relaxation shifts to low temperatures with the increase of magnetic field. The observed field induced dielectric relaxation below the reentered charge ordered state is linked with the rapid motions of boundaries of the coexisting phases towards the martensite phase transformation.

Chandrasekhar, K. Devi; Das, A. K.; Venimadhav, A.

2013-05-01

33

Direct evidence of phase segregation and magnetic-field-induced structural transition in Nd0.5Sr0.5MnO3 by neutron diffraction  

NASA Astrophysics Data System (ADS)

We present direct evidence of the phase segregation and magnetic-field-induced structural transition in Nd0.5Sr0.5MnO3 as proposed earlier [R. Mahendiran et al., Phys. Rev. Lett. 82, 2191 (1999)] for the collapse of the charge-ordered insulating state. The spontaneous (H=0) low-temperature phase at 125 K is found to be phase segregated into two different crystallographic structures and three magnetic phases: orthorhombic (Imma) ferromagnetic, orthorhombic (Imma) A-type antiferromagnetic, and monoclinic (P21/m) charge-ordered CE-type antiferromagnetic phases. Under a field of H=6 T, the charge-ordered monoclinic phase collapses and completely transforms into the metallic ferromagnetic orthorhombic phase.

Ritter, C.; Mahendiran, R.; Ibarra, M. R.; Morellon, L.; Maignan, A.; Raveau, B.; Rao, C. N. R.

2000-04-01

34

Phenomenology of giant magnetic-field-induced strain in ferromagnetic shape-memory materials (invited)  

SciTech Connect

Ferromagnetic shape-memory alloys have recently emerged as a new class of active materials showing very large magnetic-field-induced extensional strains. Recently, a single crystal of a tetragonally distorted Heusler alloy in the NiMnGa system has shown a 5% shear strain at room temperature in a field of 4 kOe. The magnetic and crystallographic aspects of the twin-boundary motion responsible for this effect are described. Ferromagnetic shape-memory alloys strain by virtue of the motion of the boundaries separating adjacent twin variants. The twin-boundary motion is driven by the Zeeman energy difference between the adjacent twins due to their nearly orthogonal magnetic easy axes and large magnetocrystalline anisotropy. The twin boundary constitutes a nearly 90 degree sign domain wall. Essentially, twin-boundary motion shorts out the more difficult magnetization rotation process. The field and stress dependence of the strain are reasonably well accounted for by minimization of a simple free energy expression including Zeeman energy, magnetic anisotropy energy, internal elastic energy, and external stress. Models indicate the limits to the magnitude of the field-induced strain and point to the material parameters that make the effect possible. The field-induced strain in ferromagnetic shape-memory alloys is contrasted with the more familiar phenomenon of magnetostriction. (c) 2000 American Institute of Physics.

O'Handley, R. C. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Murray, S. J. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Marioni, M. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Nembach, H. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Allen, S. M. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2000-05-01

35

Nanosize effects on the magnetic field induced transitions in La0.67-xEuxCa0.33MnO3 perovskite manganite  

NASA Astrophysics Data System (ADS)

The nanosize effects on magnetic field induced transitions in La0.67-xEuxCa0.33MnO3 (x=0.25 and 0.27) system are presented in this paper. The reduction in the particle size of the system shows drastic effects on the electrical transport properties leading to robustness of the charge ordering phenomenon. The metal-insulator transition found in bulk materials at low magnetic fields disappeared in nanoparticles of the same material and a high field induced metal-insulator transition emerged at lower temperatures. These results manifest a strong correlation between the chemical pressures induced by doping of various ions at A-site and nanosize related phenomenon.

Raju, N.; Roja Sree, D.; Reddy, S. Shravan Kumar; Reddy, Ch. Gopal; Reddy, P. Yadagiri; Reddy, K. Rama; Reddy, V. Raghavendra; Reddy Turpu, Goverdhan

2014-11-01

36

Magnetic-field induced type I to type II transition in ? multiple quantum well samples  

NASA Astrophysics Data System (ADS)

A series of four 0268-1242/12/10/011/img10 multiple quantum well samples with Mn concentrations x of about 7.5% and well widths ranging from 40 Å to 100 Å have been studied by below-bandgap photomodulated reflectivity (BPR) at a temperature of 1.5 K and in magnetic fields up to 6 T in the Faraday geometry. The band alignment in zero magnetic field is type I with the ZnTe being the quantum well material. The giant Zeeman splitting (due to the s, p - d exchange interaction between the 0268-1242/12/10/011/img11 ions and the free carriers) makes possible a magnetic-field induced transition of the band alignment from type I to type II: for the 0268-1242/12/10/011/img12 heavy-hole potential, the well region moves from the ZnTe layer to the 0268-1242/12/10/011/img13 layer when the magnetic field is increased sufficiently. This type I - type II transition can be monitored by the magnetic-field dependence of the excitonic transitions, particularly of those that involve the 0268-1242/12/10/011/img12 heavy-hole state, such as the 0268-1242/12/10/011/img15 excitonic transition in the quantum well. The magnetic field dependences of the heavy-hole excitonic transitions obtained from the BPR spectra were compared with calculations in which the effects of chemical valence band offset (VBO), strain, exciton binding energy, interface roughness and, most importantly, the enhanced paramagnetism at the interfaces were accounted for. It was found that a determination of the chemical VBO is independent of the state of the interface for the samples with wider well width (0268-1242/12/10/011/img16 Å), but that effects of interface roughness cannot be neglected for smaller well widths (<50 Å). Taking all these factors into account the best agreement between experiment and calculation was obtained for a chemical VBO of 0268-1242/12/10/011/img17.

Klar, P. J.; Watling, J. R.; Wolverson, D.; Davies, J. J.; Ashenford, D. E.; Lunn, B.

1997-10-01

37

Boundary conditions for quadrupolar metamaterials  

NASA Astrophysics Data System (ADS)

One of the long-standing problems in effective medium theories is using the knowledge of the bulk material response to predict the behavior of the electromagnetic fields at the material boundaries. Here, using a first principles approach, we derive the boundary conditions satisfied by the macroscopic fields at interfaces between reciprocal metamaterials with a quadrupolar-type response. Our analysis reveals that in addition to the usual Maxwellian-type boundary conditions for the tangential fields, in general—to ensure the conservation of the power flow and Lorentz reciprocity—it is necessary to enforce an additional boundary condition (ABC) at an interface between a quadrupolar material and a standard dielectric. It is shown that the ABC is related to the emergence of an additional wave in the bulk quadrupolar medium.

Silveirinha, Mário G.

2014-08-01

38

Tunable fringe magnetic fields induced by converse magnetoelectric coupling in a FeGa/PMN-PT multiferroic heterostructure  

NASA Astrophysics Data System (ADS)

The fringe magnetic field, induced by magnetoelectric coupling in a bilayer Fe-Ga/Pb(Mg1/3Nb2/3)O3_PbTiO3 (PMN-PT) multifunctional composite, was investigated. The induced external field is characterized as having a butterfly hysteresis loop when tuned by an applied electric field. A tuning coefficient of the electrically induced fringe magnetic field is derived from the piezoelectric and magnetostrictive properties of the composite. A measured maximum tuning coefficient, 4.5 Oe/(kV cm-1), is found to agree well with theoretical prediction. This work establishes a foundation in the design of transducers based on the magnetoelectric effect.

Fitchorov, Trifon; Chen, Yajie; Hu, Bolin; Gillette, Scott M.; Geiler, Anton; Vittoria, Carmine; Harris, Vincent G.

2011-12-01

39

Disorder and magnetic-field-induced breakdown of helical edge conduction in an inverted electron-hole bilayer  

NASA Astrophysics Data System (ADS)

We calculate the conductance of a two-dimensional bilayer with inverted electron-hole bands to study the sensitivity of the quantum spin Hall insulator (with helical edge conduction) to the combination of electrostatic disorder and a perpendicular magnetic field. The characteristic breakdown field for helical edge conduction splits into two fields with increasing disorder, a field Bc for the transition into a quantum Hall insulator (supporting chiral edge conduction) and a smaller field Bc' for the transition to bulk conduction in a quasimetallic regime. The spatial separation of the inverted bands, typical for broken-gap InAs/GaSb quantum wells, is essential for the magnetic-field-induced bulk conduction—there is no such regime in HgTe quantum wells.

Pikulin, D. I.; Hyart, T.; Mi, Shuo; Tworzyd?o, J.; Wimmer, M.; Beenakker, C. W. J.

2014-04-01

40

Light-induced nuclear quadrupolar relaxation in semiconductors  

E-print Network

Light excitation of a semiconductor, known to dynamically-polarize the nuclear spins by hyperfine contact interaction with the photoelectrons, also generates an intrinsic nuclear depolarization mechanism. This novel relaxation process arises from the modulation of the nuclear quadrupolar Hamiltonian by photoelectron trapping and recombination at nearby localized states. For nuclei near shallow donors, the usual diffusion radius is replaced by a smaller, quadrupolar, radius. If the light excitation conditions correspond to partial donor occupation by photoelectrons, the nuclear magnetization and the nuclear field can be decreased by more than one order of magnitude.

Paget, Daniel; Korb, J P

2008-01-01

41

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

E-print Network

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...

Karaca, Haluk Ersin

2009-05-15

42

Magnetic-Field-induced Transitions in Multiferroic TbMnO3 Probed by Resonant  

SciTech Connect

Multiferroic TbMnO3 is investigated using x-ray diffraction in high magnetic fields. Measurements on first and second harmonic structural reflections due to modulations induced by the Mn and Tb magnetic order are presented as function of temperature and field oriented along the a and b-directions of the crystal. The relation to changes in ordering of the rare earth moments in applied field is discussed. Observations below T{sub N}(Tb) without and with applied magnetic field point to a strong interaction of the rare earth order, the Mn moments and the lattice. Also, the incommensurate to commensurate transition of the wave vector at the critical fields is discussed with respect to the Tb and Mn magnetic order and a phase diagram on basis of these observations for magnetic fields H||a and H||b is presented. The observations point to a complicated and delicate magneto-elastic interaction as function of temperature and field.

Strempfer,J.; Bohnenbuck, B.; Zegkinoglou, I.; Aliouane, N.; Landsgesell, S.; Zimmermann, M.; Argyriou, D.

2008-01-01

43

Magnetic-field induced inequivalent vortex zero modes in strained graphene  

NASA Astrophysics Data System (ADS)

Zero energy states in the Dirac spectrum with U(1) symmetric massive vortices of various underlying insulating orders in strained graphene are constructed in the presence of the magnetic field. An easy-plane vortex of antiferromagnet and quantum spin Hall orders host two zero energy states, however, with two different length scales. Such inequivalent zero modes can lead to oscillatory charge and magnetization, and their usual quantizations get restored only far from the vortex core. Otherwise, these zero modes can be delocalized from each other by tuning the mutual strength of two fields. One can, therefore, effectively bind a single zero mode in the vortex core. A possible experimental setup to capture signature of this theory in real graphene as well as in optical honeycomb lattices is mentioned. Generalization of this scenario with underlying topological defects of Kekulé superconductors can localize a single Majorana mode in the vicinity of the defect core.

Roy, Bitan

2012-04-01

44

Magnetic-field-induced polarization and magnetocapacitance in quantum paraelectric EuTiO3  

NASA Astrophysics Data System (ADS)

EuTiO3 is a quantum paraelectric as well as an antiferromagnet. The most attractive property for EuTiO3 is the magnetoelectric coupling effect. In the present work, we investigate the influence of the external fields on EuTiO3, including the electric field E and magnetic field h. The application of the electric field counteracts the quantum fluctuation and forces the system into an electrically ordered state. The applied magnetic field directly induces the fluctuation of the spin-pair correlation and indirectly influences the dielectric behaviors through the magnetoelectric coupling. In addition, we notice that the contribution of the magnetic field depends closely on the temperature condition and the electric field background. The (p, h, E, T) and (, h, T) diagrams are presented showing the temperature, magnetic and electric field dependence of the polarization and the dielectric capacitance.

Gong, S. J.; Jiang, Q.

2004-11-01

45

Magnetic field-induced dissipation-free state in superconducting nanostructures.  

PubMed

A superconductor in a magnetic field acquires a finite electrical resistance caused by vortex motion. A quest to immobilize vortices and recover zero resistance at high fields made intense studies of vortex pinning one of the mainstreams of superconducting research. Yet, the decades of efforts resulted in a realization that even promising nanostructures, utilizing vortex matching, cannot withstand high vortex density at large magnetic fields. Here, we report a giant reentrance of vortex pinning induced by increasing magnetic field in a W-based nanowire and a TiN-perforated film densely populated with vortices. We find an extended range of zero resistance with vortex motion arrested by self-induced collective traps. The latter emerge due to order parameter suppression by vortices confined in narrow constrictions by surface superconductivity. Our findings show that geometric restrictions can radically change magnetic properties of superconductors and reverse detrimental effects of magnetic field. PMID:23385582

Córdoba, R; Baturina, T I; Sesé, J; Mironov, A Yu; De Teresa, J M; Ibarra, M R; Nasimov, D A; Gutakovskii, A K; Latyshev, A V; Guillamón, I; Suderow, H; Vieira, S; Baklanov, M R; Palacios, J J; Vinokur, V M

2013-01-01

46

Magnetic-field-induced strain in Ni2MnGa shape-memory alloy (abstract)  

NASA Astrophysics Data System (ADS)

Rare-earth/transition-metal alloys can exhibit magnetostrictive strains of order 0.17% in modest fields. Larger strains are of interest for many actuator applications. Certain alloys that undergo martensitic transformations exhibit a shape-memory effect that can yield strains up to 20% upon heating the deformed martensitic phase and they can show superelasticity upon application of a small stress. These methods of activation can be a disadvantage for many applications; magnetic activation of a shape-memory effect is desired. Several magnetic shape-memory alloys exist, among them intermetallics based on Ni2MnGa, which are the subject of this work. These materials experience a 6.6% c-axis contraction on cooling through the martensitic transition temperature, which is near 273 K; this strain is accommodated by formation of an ensemble of strained twin crystals separated by twin boundaries. Strains of several percent could be produced magnetically if the twin boundaries could be moved under application of a magnetic field. We report observations of strains of nearly 0.2% induced along [001] in unstressed crystals of Ni2MnGa with magnetic fields of 8 kOe applied at 265 K (Fig. 1). (This strain is an order of magnitude larger than the magnetostrictive strain we measure in the parent Heusler phase at 283 K.) Our data suggest that these giant strains are associated with the superelastic motion of twin boundaries in the martensitic phase, which is stable below about 274 K; the strength of the measured anisotropy energy density, MSHa/2 is comparable to the elastic energy density, e?/2, needed for superelastic twin boundary motion.1 The strains we observe are equivalent to those achieved in terfenol-D and represent only a small fraction of the strain available if the twin variants of the martensitic phase can be oriented prior to application of a field.

Ullakko, K.; Huang, J. K.; Kanter, C.; Kokorin, V. V.; O'Handley, R. C.

1997-04-01

47

Analytical expressions and lineshape simulations for Levitt-Suter-Ernst composite-pulse quadrupolar echo sequences  

NASA Astrophysics Data System (ADS)

Analytical expressions are derived for the Levitt-Suter-Emst composite quadrupolar echo sequences, allowing facile lineshape calculations for comparison with experiment. Large phase distortions in the lineshape obtained with the first-order sequence are significantly reduced with the second-order sequence. For 90° pulse lengths greater than ˜5?s, both sequences produce large phase errors for typical 2H quadrupolar coupling strengths in solids.

Barbara, Thomas M.

48

NMR heteronuclear correlation between quadrupolar nuclei in solids.  

PubMed

We show for the first time that it is possible to acquire high-resolution heteronuclear NMR correlation experiments in solid state between second-order-broadened half integer quadrupolar nuclei (i.e., 27Al and 17O) using the scalar J-coupling. The sensitivity of the experiment is dramatically improved at high fields (gain proportional to the fourth power of the principal field) with a combination of signal enhancement techniques. This turns a challenging experiment into a real tool. We apply this experiment to characterize a calcium aluminate glass in which we prove the presence of tricluster mu3 oxygen sites and describe the signature of their directly bonded aluminum sites. Applications involve a large range of possible pairs of quadrupolar nuclei in different materials, such as glasses, porous or mesoporous framework materials, zeolites, hybrid organic-inorganic, and bioinvolved materials. PMID:16104696

Iuga, Dinu; Morais, Claudia; Gan, Zhehong; Neuville, Daniel R; Cormier, Laurent; Massiot, Dominique

2005-08-24

49

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

NASA Astrophysics Data System (ADS)

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.

Jin, Tao; qichao, Wu; Ning, Zhang

2014-09-01

50

Direct evidence on magnetic-field-induced phase transition in a NiCoMnIn ferromagnetic shape memory alloy under a stress field.  

SciTech Connect

The magnetoelasticity and magnetoplasticity behaviors of a Ni-Co-Mn-In ferromagnetic shape memory alloy (FSMA) induced by the reverse phase transformation interplayed under multiple (temperature, magnetic, and stress) fields were captured directly by high-energy synchrotron x-ray diffraction technique. The experiments showed the direct experimental evidence of that a stress ({approx}50 MPa) applied to this material made a complete recovery of the original orientations of the martensite variants, showing a full shape memory effect. This finding offers the in-depth understanding the fundamental properties and applications of the Ni-Co-Mn-In FSMA with the magnetic-field-induced reverse transformation.

Wang, Y. D.; Ren, Y.; Huang, E. W.; Nie, Z. H.; Wang, G.; Liu, Y. D.; Deng, J. N.; Zuo, L.; Choo, H.; Liaw, P .K.; Brown, D. E.; Univ. of Tennessee; Northeastern Univ.; Northern Illinois Univ.

2007-01-01

51

Direct evidence on magnetic-field-induced phase transition in a NiCoMnIn ferromagnetic shape memory alloy under a stress field  

SciTech Connect

The magnetoelasticity and magnetoplasticity behaviors of a Ni-Co-Mn-In ferromagnetic shape memory alloy (FSMA) induced by the reverse phase transformation interplayed under multiple (temperature, magnetic, and stress) fields were captured directly by high-energy synchrotron x-ray diffraction technique. The experiments showed the direct experimental evidence of that a stress ({approx}50 MPa) applied to this material made a complete recovery of the original orientations of the martensite variants, showing a full shape memory effect. This finding offers the in-depth understanding the fundamental properties and applications of the Ni-Co-Mn-In FSMA with the magnetic-field-induced reverse transformation.

Wang, Y. D.; Ren Yang; Huang, E. W.; Nie, Z. H.; Wang, G.; Liu, Y. D.; Deng, J. N.; Zuo, L.; Choo, H.; Liaw, P. K.; Brown, D. E. [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110004 (China) and Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996 (United States); X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110004 (China); Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Department of Physics, Northern Illinois University, DeKalb, Illinois 60115 (United States)

2007-03-05

52

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

SciTech Connect

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.

Fernandez, Christian; Pruski, Marek

2011-06-08

53

Magnetic field induced lattice effects in a quasi-two-dimensional organic conductor close to the Mott metal-insulator transition  

NASA Astrophysics Data System (ADS)

We present ultra-high-resolution dilatometric studies in magnetic fields on a quasi-two-dimensional organic conductor ?-(D8-BEDT-TTF)2Cu[N(CN)2]Br, which is located close to the Mott metal-insulator (MI) transition. The obtained thermal expansion coefficient, ?(T), reveals two remarkable features: (i) the Mott MI transition temperature TMI=(13.6±0.6) K is insensitive to fields up to 10 T, the highest applied field; (ii) for fields along the interlayer b axis, a magnetic field induced (FI) phase transition at TFI=(9.5±0.5) K is observed above a threshold field Hc˜1 T, indicative of a spin reorientation with strong magnetoelastic coupling.

de Souza, Mariano; Brühl, Andreas; Strack, Christian; Schweitzer, Dieter; Lang, Michael

2012-08-01

54

Quantum manipulation on the Barium quadrupolar transition  

E-print Network

and stabilization of a new fiber laser system to ma- nipulate the Barium quadrupolar transition, with the aim . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3 Trapped ion coupled to a laser field 18 3.1 Light-matter interaction . . . . . . . . . . . . . . . 55 6 Spectroscopy and sideband cooling on a single 138 Ba+ 58 6.1 Quantum jumps using the fiber laser . . . . . . . . . . . . .

Blatt, Rainer

55

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

E-print Network

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.

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

56

Orientational quadrupolar glass in ortho-para hydrogen mixtures. II. Comparison with experiment  

SciTech Connect

A comparative analysis of experimental data on the orientational order parameter, heat capacity and Gruneisen parameter with those predicted by the mean-field microscopic theory given in the accompanying paper is carried out. The orientation-motion freezing mechanisms driven by the strain, quadrupolar and reaction fields are identified. It is proved that within the quadrupolar glass (QG) phase the random-site effects dominate over random-bond dilution effects. The entry to the QG phase is characterized by the freezing temperature, at which the total intrinsic field disappears. The QG ground-state distribution function known from NMR spectroscopy is proposed.

Kokshenev, V.B. [Universidade Federal de Minas Gerais (Brazil)

1996-07-01

57

Magnetic-field-induced spontaneous polarization reversal in multiferroic Mn0.85Co0.15WO4  

NASA Astrophysics Data System (ADS)

The magnetic and ferroelectric properties of the multiferroic system Mn1-xCoxWO4 (x =0.135, 0.15, and 0.17) are studied in magnetic fields Hc oriented along the monoclinic c axis. Mn0.85Co0.15WO4, which is right at the phase boundary between two helical spin structures, exhibits a spontaneous sign change of the ferroelectric polarization when cooled in fields Hc> 25 kOe. The origin of the ferroelectric polarization is studied and two magnetic exchange interactions contributing to the polarization are identified. In Mn0.85Co0.15WO4, domains of the characteristic helical spin structures, known for x <0.15 and x >0.15, coexist and form domain boundaries. The contributions of the different domains to the global polarization are determined. The polarization reversal in Mn0.85Co0.15WO4 can be explained by a combination of various contributions to the polarization and a strong correlation between magnetic domains of different helical spin orders resulting in a smooth transition across the domain walls, which preserves the chirality of the spin spiral.

Poudel, N.; Liang, K.-C.; Wang, Y.-Q.; Sun, Y. Y.; Lorenz, B.; Ye, F.; Fernandez-Baca, J. A.; Chu, C. W.

2014-02-01

58

Nature of magnetism and magnetic-field-induced transitions in non-collinear antiferromagnet Er2O3  

NASA Astrophysics Data System (ADS)

The nature of magnetism in Er2O3 is investigated by detailed studies of the temperature (2-300 K) and magnetic field (up to 90 kOe) dependence of the magnetization M of powder sample of Er2O3. The results show paramagnetic to antiferromagnetic (AFM) transition occurring at TN=3.3 K. For T>TN the magnetic susceptibility vs. temperature data follows the Curie-Weiss (?=C/(T-?)) variation with ?=-10.2 K and magnetic moment ?=6.68 ?B/Er ion determined from C. Molecular field model is used to determine the nn (nnn) exchange constants J1(J2)=-0.57 K (-3.38 K). The M vs. H data at 2 K analyzed in terms of dM/dH vs. H variations show two field-induced transitions, the first one at HSF?15 kOe and the second one at HS?31 kOe. Arguments and analysis are presented to show that HSF represents the spin-flop transition whereas for H>HS, the system is field-aligned ferromagnetically since the calculated value of HS for ferromagnetic ordering using the above magnitudes of J1 and J2 agrees well with the experimental HS. The temperature dependence of HSF is shown to follow the normalized Brillouin function variation for spin S=1/2 valid for Er2O3. The magnetic field dependence of TN is measured and shown to follow the equation: TN(H)=TN(0)-D1H2, expected for antiferromagnets.

Narang, V.; Korakakis, D.; Seehra, M. S.

2014-11-01

59

Peculiarities of Quadrupolar Relaxation in Electrolyte Solutions  

NASA Astrophysics Data System (ADS)

Peculiarities of quadrupolar relaxation in electrolyte solutions were established via comparison of the data obtained from proton and deuteron resonances. It has been shown that quadrupole coupling constants (QCC) of deuterons depend not only on internal electron structure of molecule or ion, but on solution structure as well. To interpret the experimental results quantum-chemical calculations of QCC of deuterons in different molecular complexes simulating different solution substructures were carried out. Density functional theory (DFT) method with hybrid B3LYP functional was used for all calculations.

Pavlova, Maria; Chizhik, Vladimir

2004-11-01

60

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

NASA Astrophysics Data System (ADS)

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.

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

2014-01-01

61

Separate-Local-Field NMR Spectroscopy on Half-Integer Quadrupolar Nuclei Julia Grinshtein, Christopher V. Grant, and Lucio Frydman*  

E-print Network

constituents in a variety of inorganic, organic, and biological structures.1 The strong first-order quadrupolar NMR experi- ments is that which combines relatively fast sample spinning, with a 2nÃ? magnification on this deoxycytosine salt. A visual analysis evidences the ongoing magnification of the effective dipolar couplings

Frydman, Lucio

62

SIMQUADNMR: a program for simulation and interpretation of multiple quantum-filtered NMR spectra of quadrupolar nuclei  

Microsoft Academic Search

In this paper, we present a computer program which simulates NMR multiple quantum-filtered spectra of quadrupolar nuclei as a function of physical parameters, of the type of experiment and experimental conditions. The program works by solving relaxation theory equations for the given system, and it can be useful in order to plan the ideal conditions to set up specific experiments

Nicola D’Amelio; Elena Gaggelli; Elena Molteni; Gianni Valensin

2005-01-01

63

Kn 26, a New Quadrupolar Planetary Nebula  

E-print Network

Once classified as an emission line source, the planetary nebula (PN) nature of the source Kn 26 has been only recently recognized in digital sky surveys. To investigate the spectral properties and spatio-kinematical structure of Kn 26, we have obtained high spatial-resolution optical and near-IR narrow-band images, high-dispersion long-slit echelle spectra, and intermediate-resolution spectroscopic observations. The new data reveal an hourglass morphology typical of bipolar PNe. A detailed analysis of its morphology and kinematics discloses the presence of a second pair of bipolar lobes, making Kn 26 a new member of the subclass of quadrupolar PNe. The time-lap between the ejection of the two pairs of bipolar lobes is much smaller than their dynamical ages, implying a rapid change of the preferential direction of the central engine. The chemical composition of Kn 26 is particularly unusual among PNe, with a low N/O ratio (as of type II PNe) and a high helium abundance (as of type I PNe), although not atypica...

Guerrero, Martin A; Ramos-Larios, Gerardo; Vazquez, Roberto

2013-01-01

64

A system for NMR stark spectroscopy of quadrupolar nuclei.  

PubMed

Electrostatic influences on NMR parameters are well accepted. Experimental and computational routes have been long pursued to understand and utilize such Stark effects. However, existing approaches are largely indirect informants on electric fields, and/or are complicated by multiple causal factors in spectroscopic change. We present a system to directly measure quadrupolar Stark effects from an applied electric (E) field. Our apparatus and applications are relevant in two contexts. Each uses a radiofrequency (rf) E field at twice the nuclear Larmor frequency (2omega(0)). The mechanism is a distortion of the E-field gradient tensor that is linear in the amplitude (E(0)) of the rf E field. The first uses 2omega(0) excitation of double-quantum transitions for times similar to T(1) (the longitudinal spin relaxation time). This perturbs the steady state distribution of spin population. Nonlinear analysis versus E(0) can be used to determine the Stark response rate. The second context uses POWER (perturbations observed with enhanced resolution) NMR. Here, coherent, short-time (quadrupolar multiplet with splitting proportional to E(0). The POWER sequence converts the 2omega(0) interaction from off-diagonal/nonsecular to the familiar diagonal form (I(z)(2)) of static quadrupole interactions. Meanwhile, background contributions to line width are averaged to zero, providing orders-of-magnitude resolution enhancement for correspondingly high sensitivity to the Stark effect. Using GaAs as a test case with well-defined Stark response, we provide the first demonstration of the 2omega(0) effect at high-field (14.1 T) and room temperature. This, along with the simplicity of our apparatus and spectral approach, may facilitate extensions to a wider array of material and molecular systems. The POWER context, which has not previously been tested, is detailed here with new design insights. Several key aspects are demonstrated here, while complete implementation is to be presented at a later time. At present, we (1) account for finite pulse times in pulse sequence design, (2) demonstrate two-channel phase coherence for magnetic (omega(0)) and electric (2omega(0)) excitation, and (3) provide line narrowing by a factor of 10(3). In addition, we find that certain anomalous contributions to the line shape, observed in previous low-field (250 mT) applications, are absent here. PMID:20394397

Tarasek, Matthew R; Kempf, James G

2010-05-13

65

Kn 26, a new quadrupolar planetary nebula  

NASA Astrophysics Data System (ADS)

Once classified as an emission line source, the planetary nebula (PN) nature of the source Kn 26 has only recently been recognized in digital sky surveys. To investigate the spectral properties and spatio-kinematical structure of Kn 26, we have obtained high spatial-resolution optical and near-IR narrow-band images, high-dispersion long-slit echelle spectra, and intermediate-resolution spectroscopic observations. The new data reveal an hourglass morphology typical of bipolar PNe. A detailed analysis of its morphology and kinematics discloses the presence of a second pair of bipolar lobes, making Kn 26 a new member of the subclass of quadrupolar PNe. The time lapse between the ejection of the two pairs of bipolar lobes is much shorter than their dynamical ages, implying a rapid change in the preferential direction of the central engine. The chemical composition of Kn 26 is particularly unusual among PNe, with a low N/O ratio (as for type II PNe) and a high helium abundance (as for type I PNe), although not atypical among symbiotic stars. Such an anomalous chemical composition may have resulted from the curtailment of the time in the asymptotic giant branch by the evolution of the progenitor star through a common envelope phase. Based on observations made with the Nordic Optical Telescope (NOT) and the William Herschel Telescope (WHT) on the island of La Palma in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias (IAC), the 2.1-m telescope of the Observatorio Astronómico Nacional at the Sierra de San Pedro Mártir (OAN-SPM), and the 1.5-m telescope at the Observatorio de Sierra Nevada (OSN), Granada, Spain. NOT is operated jointly by Denmark, Finland, Iceland, Norway, and Sweden. WHT is operated by the Isaac Newton Group. The 2.1-m telescope at the OAN-SPM is a national facility operated by the Instituto de Astronomía of the Universidad Nacional Autónoma de México. The 1.5-m telescope at the OSN is operated by the Instituto de Astrofísica de Andalucía (IAA).The data presented here were obtained in part with ALFOSC, which is provided by the IAA under a joint agreement with the University of Copenhagen and NOTSA.FITS files for spectra and images are available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr(130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/551/A53

Guerrero, M. A.; Miranda, L. F.; Ramos-Larios, G.; Vázquez, R.

2013-03-01

66

Infrared Spectra of Polar Diatomic Molecules in Quadrupolar Condensed Solvents  

Microsoft Academic Search

The present paper is devoted to the computation of the infrared spectral properties of couples containing a polar and a quadrupolar molecule located at fixed distances which are permanently realized in condensed media. A study of the orientational quantum states of such couples using an asymptotic method is presented. This method is particularly suited when the angle dependent variation of

C. Girardet; D. Robert; L. Galatry

1971-01-01

67

H_2 in the Quadrupolar Planetary Nebula NGC 6881  

Microsoft Academic Search

NGC 6881 is one of the very few quadrupolar PNe, which is constituted by 2 pairs of bipolar lobes oriented towards different directions. This morphology is indicative of changes in the direction of the ejection of material, suggesting the precession of the equatorial ring. The H_2 and optical morphology of NGC 6881 are very different. To investigate in detail the

G. Ramos-Larios; M. A. Guerrero; L. F. Miranda

2009-01-01

68

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

ERIC Educational Resources Information Center

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…

Patil, S. H.

2009-01-01

69

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

NASA Astrophysics Data System (ADS)

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.

Mandujano, Miguel G.; Maytorena, Jesús A.

2013-08-01

70

Magnetic field induced changes in the critical exponent {beta} of the chiral triangular antiferromagnet CsMnBr{sub 3} in the presence of an electric field (abstract)  

SciTech Connect

The magnetic moments in the triangular antiferromagnetic CsMnBr{sub 3} order at T{sub N}=8.3 K with a frustration of the magnetic moments in a 120{degree} type magnetic structure. The magnetic moments are either ordered in a clockwise or an anticlockwise direction resulting in a chirality ordering, which is characterized by the critical exponent of the magnetic sublattice magnetization {beta}=0.25. It has been shown that an electric field applied along the [110] direction removes the chiral ordering and a linear Ising-like phase will be established; consequently, the value of {beta} decreases. The subsequent application of a magnetic field of B=4 T along the [100] direction causes the critical exponent {beta} to increase. The magnetic phase diagram of CsMnBr{sub 3} does not change due to the introduction of an electric field.{copyright} {ital 1997 American Institute of Physics.}

Visser, D. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)] [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Monteith, A.R. [The Royal Institution of Great Britain, 21 Albemarle Street, London W1X 4BS (United Kingdom)] [The Royal Institution of Great Britain, 21 Albemarle Street, London W1X 4BS (United Kingdom); Bargawi, A.Y. [Department of Physics, Umm Al-Qura University, Makkah (Saudi Arabia)] [Department of Physics, Umm Al-Qura University, Makkah (Saudi Arabia); Zeiske, T. [BENSC, Hahn Meitner Institut, Glienecker Strasse 100, Berlin (Germany)] [BENSC, Hahn Meitner Institut, Glienecker Strasse 100, Berlin (Germany)

1997-04-01

71

SCAM-STMAS: satellite-transition MAS NMR of quadrupolar nuclei with self-compensation for magic-angle misset  

NASA Astrophysics Data System (ADS)

Several methods are available for the acquisition of high-resolution solid-state NMR spectra of quadrupolar nuclei with half-integer spin quantum number. Satellite-transition MAS (STMAS) offers an approach that employs only conventional MAS hardware and can yield substantial signal enhancements over the widely used multiple-quantum MAS (MQMAS) experiment. However, the presence of the first-order quadrupolar interaction in the satellite transitions imposes the requirement of a high degree of accuracy in the setting of the magic angle on the NMR probehead. The first-order quadrupolar interaction is only fully removed if the sample spinning angle, ?, equals cos-1(1/ 3) exactly and rotor synchronization is performed. The required level of accuracy is difficult to achieve experimentally, particularly when the quadrupolar interaction is large. If the magic angle is not set correctly, the first-order splitting is reintroduced and the spectral resolution is severely compromised. Recently, we have demonstrated a novel STMAS method (SCAM-STMAS) that is self-compensated for angle missets of up to ±1° via coherence transfer between the two different satellite transitions ST +( mI=+3/2?+1/2) and ST -( mI=-1/2?-3/2) midway through the t1 period. In this work we describe in more detail the implementation of SCAM-STMAS and demonstrate its wider utility through 23Na ( I=3/2), 87Rb ( I=3/2), 27Al ( I=5/2), and 59Co ( I=7/2) NMR. We discuss linewidths in SCAM-STMAS and the limits over which angle-misset compensation is achieved and we demonstrate that SCAM-STMAS is more tolerant of temporary spinning rate fluctuations than STMAS, resulting in less " t1 noise" in the two-dimensional spectrum. In addition, alternative correlation experiments, for example involving the use of double-quantum coherences, that similarly display self-compensation for angle misset are investigated. The use of SCAM-STMAS is also considered in systems where other high-order interactions, such as third-order quadrupolar effects or second-order quadrupole-CSA cross-terms, are present. Finally, we show that the sensitivity of the experiment can be improved through the use of amplitude-modulated pulses.

Ashbrook, Sharon E.; Wimperis, Stephen

2003-06-01

72

Rotor-synchronized acquisition of quadrupolar satellite-transition NMR spectra: practical aspects and double-quantum filtration  

NASA Astrophysics Data System (ADS)

The very broad resonances of quadrupolar (spin I > 1/2) nuclei are resolved by magic angle spinning (MAS) into a large number of spinning sidebands, each of which often remains anisotropically broadened. The quadrupolar interaction can be removed to a first-order approximation if the MAS NMR spectrum is acquired in a rotor-synchronized fashion, aliasing the spinning sidebands onto a centreband and thereby increasing the signal-to-noise ratio in the resulting, possibly second-order broadened, spectrum. We discuss the practical aspects of this rotor-synchronization in the direct ( t2) time domain, demonstrating that the audiofrequency filters in the receiver section of the spectrometer have a significant impact on the precise timings needed in the experiment. We also introduce a novel double-quantum filtered rotor-synchronized experiment for half-integer spin quadrupolar (spin I = 3/2, 5/2, etc.) nuclei that makes use of central-transition-selective inversion pulses to both excite and reconvert double-quantum coherences and yields a simplified spectrum containing only the ST 1 ( mI = ± 1/2 ? ± 3/2) satellite-transition lineshapes. For spin I = 5/2 nuclei, such as 17O and 27Al, this spectrum may exhibit a significant resolution increase over the conventional central-transition spectrum.

Ashbrook, Sharon E.; Wimperis, Stephen

2005-11-01

73

Cross polarization for quadrupolar nuclei—Proton to sodium-23  

NASA Astrophysics Data System (ADS)

The role of cross polarization in magic-angle spinning spectra of quadrupolar nuclei for solids is discussed, using the 1H ? 23Na case as an example. Suitable materials for spectrometer tuning in this mode are proposed and sample spectra presented. Some relaxation experiments on the 23Na signals for borax were carried out, and the selectivity of the cross-polarization experiment is shown for the layer mineral kenyaite.

Harris, Robin K.; Nesbitt, Geoffrey J.

74

Two-dimensional nuclear magnetic resonance of quadrupolar systems  

SciTech Connect

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.

Wang, Shuanhu

1997-09-17

75

Orientational quadrupolar glass in ortho-para hydrogen mixtures. I. Mean-field microscopic theory  

SciTech Connect

The mean-field theory of the quadrupolar glass (QG) is presented using a microscopic approach. It is shown that the reaction-polarization effects caused by short-range spatial correlations are well distinguished from those of random-bond spin glasses. They control the QG concentration threshold and result in an incomplete orientational order. The QG ground state (zero quadrupolization, unsaturated Edwards-Anderson-type orientational order parameter) is predicted. Thermodynamic characteristics, namely entropy, pressure and free energy as well as the related heat capacity and Gruneisen parameter are estimated. The ground-state findings (incomplete order, residual entropy) are similar to those of short-range Potts glasses. A correspondence between density matrix and mean field treatment to the QG problem is also discussed.

Kokshenev, V.B. [Inst. for Low Temperature Physics and Engineering of the Academy of Science of Ukraine, Kharkov (Ukraine)

1996-07-01

76

Magnetic-field-induced quantum critical point in YbPtIn and YbPt0.98In single crystals  

NASA Astrophysics Data System (ADS)

Detailed anisotropic ( H?ab and H?c ) resistivity and specific heat measurements were performed on on-line-grown YbPtIn and solution-grown YbPt0.98In single crystals for temperatures down to 0.4K and fields up to 140kG ; H?ab Hall resistivity was also measured on the YbPt0.98In system for the same temperature and field ranges. All these measurements indicate that the small change in stoichiometry between the two compounds drastically affects their ordering temperatures ( Tord?3.4K in YbPtIn and ˜2.2K in YbPt0.98In ). Furthermore, a field-induced quantum critical point is apparent in each of these heavy fermion systems, with the corresponding critical field values of YbPt0.98In ( Hcab around 35 45kG and Hcc?120kG ) also reduced compared to the analogous values for YbPtIn ( Hcab?60kG and Hcc>140kG ).

Morosan, E.; Bud'Ko, S. L.; Mozharivskyj, Y. A.; Canfield, P. C.

2006-05-01

77

Quadrupolar Kondo effect in uranium heavy-electron materials?  

NASA Technical Reports Server (NTRS)

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.

Cox, D. L.

1987-01-01

78

Quadrupolar and Chemical Shift Tensors Characterized by 2D Multiple-Quantum NMR Spectroscopy  

E-print Network

Quadrupolar and Chemical Shift Tensors Characterized by 2D Multiple-Quantum NMR Spectroscopy Ales The present work discusses a new 2D NMR method for char- acterizing the principal values and relative; multiple-quantum spectroscopy; 2D NMR correlations. 1. INTRODUCTION Quadrupolar nuclei with half

Frydman, Lucio

79

Quadrupolar interaction study of various cations confined in porous charged polymer film of sPI ionomers.  

PubMed

The structure of a sulfonated polyimide (sPI) ionomer membranes was investigated via the transport properties of various confined cations (7Li+, 23Na+, 87Rb+, 133Cs+). Their NMR spectra show large residual quadrupolar splitting depending on the orientation of the film in the static magnetic field B0. This behavior is the fingerprint of a macroscopic nematic ordering of charged interfaces. This is also confirmed by the anisotropy of the self-diffusion tensor measured by 1H and 7Li PGSE experiments on N(CH3)4+ and Li+ cations, respectively. PMID:15833649

Rollet, Anne-Laure; Porion, Patrice; Delville, Alfred; Diat, Olivier; Gebel, Gérard

2005-02-01

80

Spin squeezing in an ensemble of quadrupolar nuclei NMR system  

E-print Network

We have characterized spin-squeezed states produced at a temperature of $26^\\circ{\\mathrm C}$ on a Nuclear Magnetic Resonance (NMR) quadrupolar system. The implementation is carried out in an ensemble of $^{133}$Cs nuclei with spin $I=7/2$ of a lyotropic liquid crystal sample. We identify the source of spin squeezing due to the interaction between the quadrupole moment of the nuclei and the electric field gradients internally present in the molecules. We use the spin angular momentum representation to describe formally the nonlinear operators that produce the spin squeezing. The quantitative and qualitatively characterization of the spin squeezing phenomena is performed through a squeezing parameter and squeezing angle developed for the two-mode BEC system, and, as well, by the Wigner quasi-probability distribution function. The generality of the present experimental scheme indicates its potential applications on solid state physics.

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

2014-03-11

81

Quadrupolar Effect on Two Layered Thin Film Antiferroelectric Smectic Liquid Crystal  

SciTech Connect

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.

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

82

H_2 in the Quadrupolar Planetary Nebula NGC 6881  

NASA Astrophysics Data System (ADS)

NGC 6881 is one of the very few quadrupolar PNe, which is constituted by 2 pairs of bipolar lobes oriented towards different directions. This morphology is indicative of changes in the direction of the ejection of material, suggesting the precession of the equatorial ring. The H_2 and optical morphology of NGC 6881 are very different. To investigate in detail the spatial distribution of molecular and ionized material within NGC 6881 and to determine the prevalent excitation mechanism of the H[2] emission, we have obtained new near-IRBr? and H_2? = 2.1218~?m with WHT, optical H? and [NII] images with NOT, as well as intermediate resolution JHK spectra with TNG. These observations show that NGC 6881 has multiple bipolar lobes formed at different phases of the nebular evolution. The H_2 images show bipolar lobes resembling an hourglass. Although these lobes are oriented along the mayor axis of the ionized lobes, they are much less collimated. Additionally, the detected northeast lobe is 3-4 times more extended than the ionized lobes. The central region is resolved in our new H[2] images and show the spatial distribution expected for a ring lying outside the ionized material. The different spectral diagnostics indicate that the H[2] emission is produced by shock excitation in the molecule.

Ramos-Larios, G.; Guerrero, M. A.; Miranda, L. F.

2009-05-01

83

Charge ordering and magnetoresistance in Nd1-xCaxMnO3 due to reduced double exchange  

Microsoft Academic Search

Structural, transport, and magnetic properties of Nd1-xCaxMnO3 (0<=x<=1) have been studied to probe the consequence of strong lattice distortion and reduced double exchange. Charge ordering has been observed over a large composition range of 0.30<=x<=0.80. For 0.33<=x<=0.40, at low temperatures, a magnetic field induces a first-order antiferromagnetic semiconductor to ferromagnetic metal transition and reduces the resistance by several orders of

K. Liu; X. W. Wu; K. H. Ahn; T. Sulchek; C. L. Chien; John Q. Xiao

1996-01-01

84

2H2O quadrupolar splitting used to measure water exchange in erythrocytes.  

PubMed

The 2H NMR resonance from HDO (D=2H) in human red blood cells (RBCs) suspended in gelatin that was held stretched in a special apparatus was distinct from the two signals that were symmetrically arranged on either side of it, which were assigned to extracellular HDO. The large extracellular splitting is due to the interaction of the electric quadrupole moment of the 2H nuclei with the electric field gradient tensor of the stretched, partially aligned gelatin. Lack of resolved splitting of the intracellular resonance indicated greatly diminished or absent ordering of the HDO inside RBCs. The separate resonances enabled the application of a saturation transfer method to estimate the rate constants of transmembrane exchange of water in RBCs. However both the theory and the practical applications needed modifications because even in the absence of RBCs the HDO resonances were maximally suppressed when the saturating radio-frequency radiation was applied exactly at the central frequency between the two resonances of the quadrupolar HDO doublet. More statistically robust estimates of the exchange rate constants were obtained by applying two-dimensional exchange spectroscopy (2D EXSY), with back-transformation analysis. A monotonic dependence of the estimates of the efflux rate constants on the mixing time, tmix, used in the 2D EXSY experiment were seen. Extrapolation to tmix=0, gave an estimate of the efflux rate constant at 15 degrees C of 31.5+/-2.2 s(-1) while at 25 degrees C it was approximately 50 s(-1). These values are close to, but less than, those estimated by an NMR relaxation-enhancement method that uses Mn2+ doping of the extracellular medium. The basis for this difference is thought to include the high viscosity of the extracellular gel. At the abstract level of quantum mechanics we have used the quadrupolar Hamiltonian to provide chemical shift separation between signals from spin populations across cell membranes; this is the first time, to our knowledge, that this has been achieved. PMID:18291693

Kuchel, Philip W; Naumann, Christoph

2008-05-01

85

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

NASA Astrophysics Data System (ADS)

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.

Iuga, Dinu; Holland, Diane; Dupree, Ray

2014-09-01

86

Resolution enhancement using a new multiple-pulse decoupling sequence for quadrupolar nuclei  

NASA Astrophysics Data System (ADS)

A new decoupling composite pulse sequence is proposed to remove the broadening on spin S = 1/2 magic-angle spinning (MAS) spectra arising from the scalar coupling with a quadrupolar nucleus I. It is illustrated on the 31P spectrum of an aluminophosphate, AlPO 4-14, which is broadened by the presence of 27Al/ 31P scalar couplings. The multiple-pulse (MP) sequence has the advantage over the continuous wave (CW) irradiation to efficiently annul the scalar dephasing without reintroducing the dipolar interaction. The MP decoupling sequence is first described in a rotor-synchronised version (RS-MP) where one parameter only needs to be adjusted. It clearly avoids the dipolar recoupling in order to achieve a better resolution than using the CW sequence. In a second improved version, the MP sequence is experimentally studied in the vicinity of the perfect rotor-synchronised conditions. The linewidth at half maximum (FWHM) of 65 Hz using 27Al CW decoupling decreases to 48 Hz with RS-MP decoupling and to 30 Hz with rotor-asynchronised MP (RA-MP) decoupling. The main phenomena are explained using both experimental results and numerical simulations.

Delevoye, L.; Trébosc, J.; Gan, Z.; Montagne, L.; Amoureux, J.-P.

2007-05-01

87

Recent advances in solid-state NMR spectroscopy of quadrupolar nuclei.  

PubMed

Nuclear magnetic resonance (NMR) spectroscopy of quadrupolar nuclei (i.e., those with a spin quantum number I > 1/2) has always been viewed as "difficult" owing to the presence of an anisotropic broadening arising from the interaction of the nuclear electric quadrupole moment with the electric field gradient. This quadrupolar interaction can be considerable, resulting in broadening of the spectral resonances often over many MHz. Furthermore, magic-angle spinning (MAS), a conventional approach for increasing the resolution in solid-state NMR, is often unable to remove the broadening completely and high-resolution spectra are generally not obtained. Despite the vast amount of information contained in the anisotropic linewidths and lineshapes, the resolution and sensitivity challenges have, until recently, somewhat limited the application of solid-state NMR for quadrupolar nuclei. In general, structural information, such as that obtained through recoupling techniques or from two-dimensional correlation spectroscopy, is much more difficult to extract easily and accurately. However, recent advances in magnet design, probe hardware and pulse sequence development have significantly improved the ease with which quadrupolar spins can be studied and high-resolution spectra can be obtained, and recent applications are beginning to exploit the wealth of information available. In this discussion, we highlight just a few of the recent developments in this area, including new state-of-the art correlation experiments, the expanding study of nuclei with low gyromagnetic ratio, gamma, the increasing application of first-principles calculations in the solid state, and methods which exploit the quadrupolar broadening to provide information on dynamics. Whilst not a complete review, it is hoped that this brief overview of some of the more exciting recent developments can provide insight into the challenges, and the rewards, involved in the NMR study of quadrupolar nuclei. PMID:19652823

Ashbrook, Sharon E

2009-08-28

88

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

PubMed

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

Semchyschyn, Darlene J; Macdonald, Peter M

2004-02-01

89

Fundamentals of Multiple-Quantum Magic-Angle Spinning NMR on Half-Integer Quadrupolar Nuclei  

E-print Network

, these nuclei possess quadrupole moments and thus interact not only with external or internal magnetic fields the nuclear magnetic moment and the external mag- netic field Bo. If sufficiently small, quadrupole effectsFundamentals of Multiple-Quantum Magic-Angle Spinning NMR on Half-Integer Quadrupolar Nuclei Lucio

Frydman, Lucio

90

Two-photon transitions in triazole based quadrupolar and octupolar chromophores: a TD-DFT investigation.  

E-print Network

Two-photon transitions in triazole based quadrupolar and octupolar chromophores: a TD-photon properties of triazole-based chromophores. In fact, experimental data were shown to reveal quite different, NLO, time dependent density functional theory, TD-DFT, Frenkel exciton model, triazole, multibranched

Tretiak, Sergei

91

New methods and applications in solid-state NMR spectroscopy of quadrupolar nuclei.  

PubMed

Solid-state nuclear magnetic resonance (NMR) spectroscopy has long been established as offering unique atomic-scale and element-specific insight into the structure, disorder, and dynamics of materials. NMR spectra of quadrupolar nuclei (I > (1)/2) are often perceived as being challenging to acquire and to interpret because of the presence of anisotropic broadening arising from the interaction of the electric field gradient and the nuclear electric quadrupole moment, which broadens the spectral lines, often over several megahertz. Despite the vast amount of information contained in the spectral line shapes, the problems with sensitivity and resolution have, until very recently, limited the application of NMR spectroscopy of quadrupolar nuclei in the solid state. In this Perspective, we provide a brief overview of the quadrupolar interaction, describe some of the basic experimental approaches used for acquiring high-resolution NMR spectra, and discuss the information that these spectra can provide. We then describe some interesting recent examples to showcase some of the more exciting and challenging new applications of NMR spectra of quadrupolar nuclei in the fields of energy materials, microporous materials, Earth sciences, and biomaterials. Finally, we consider the possible directions that this highly informative technique may take in the future. PMID:25296129

Ashbrook, Sharon E; Sneddon, Scott

2014-11-01

92

Weak surface energy in nematic dispersions: Saturn ring defects and quadrupolar interactions  

Microsoft Academic Search

:   The role of surface energy in the behavior of colloidal particles in liquid crystalline phases is investigated. When the surface\\u000a energy dominates, a hedgehog defect is formed and, according to an electrostatic analogy, the distortions around the particles\\u000a exhibit a dipolar character. By contrast, for weaker anchoring, the configuration becomes quadrupolar as evidenced by the\\u000a structure of latex clusters

O. Mondain-Monval; J. C. Dedieu; T. Gulik-Krzywicki; P. Poulin

1999-01-01

93

High-Resolution NMR of Quadrupolar Nuclei in the Solid State  

SciTech Connect

This dissertation describes recent developments in solid state nuclear magnetic resonance (NMR), for the most part involving the use of dynamic-angle spinning (DAS) NMR to study quadrupolar nuclei. Chapter 1 introduces some of the basic concepts and theory that will be referred to in later chapters, such as the density operator, product operators, rotations, coherence transfer pathways, phase cycling, and the various nuclear spin interactions, including the quadrupolar interaction. Chapter 2 describes the theory behind motional averaging experiments, including DAS, which is a technique where a sample is spun sequentially about two axis oriented at different angles with respect to the external magnetic field such that the chemical shift and quadrupolar anisotropy are averaged to zero. Work done on various rubidium-87 salts is presented as a demonstration of DAS. Chapter 3 explains how to remove sidebands from DAS and magic-angle spinning (MAS) experiments, which result from the time-dependence of the Hamiltonian under sample spinning conditions, using rotor-synchronized {pi}-pulses. Data from these experiments, known as DAH-180 and MAH-180, respectively, are presented for both rubidium and lead salts. In addition, the applicability of this technique to double rotation (DOR) experiments is discussed. Chapter 4 concerns the addition of cross-polarization to DAS (CPDAS). The theory behind spin locking and cross polarizing quadrupolar nuclei is explained and a method of avoiding the resulting problems by performing cross polarization at 0{sup o} (parallel) with respect to the magnetic field is presented. Experimental results are shown for a sodium-23 compound, sodium pyruvate, and for oxygen-17 labeled L-akmine. In Chapter 5, a method for broadening the Hartmann-Hahn matching condition under MAS, called variable effective field cross-polarization (VEFCI?), is presented, along with experimental work on adamantane and polycarbonate.

Gann, Sheryl Lee

1995-11-30

94

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

PubMed

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

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

2014-10-22

95

Orbital-Ordering-Driven Multiferroicity and Magnetoelectric Coupling in GeV4S8  

NASA Astrophysics Data System (ADS)

We report here the discovery of multiferroicity and large magnetoelectric coupling in the type I orbital order system GeV4S8. Our study demonstrates that this clustered compound displays a para-ferroelectric transition at 32 K. This transition originates from an orbital ordering which reorganizes the charge within the transition metal clusters. Below the antiferromagnetic transition at 17 K, the application of a magnetic field significantly affects the ferroelectric polarization, revealing thus a large magnetoelectric coupling. Our study suggests that the application of a magnetic field induces a metamagnetic transition which significantly affects the ferroelectric polarization thanks to an exchange striction phenomenon.

Singh, Kiran; Simon, Charles; Cannuccia, Elena; Lepetit, Marie-Bernadette; Corraze, Benoit; Janod, Etienne; Cario, Laurent

2014-09-01

96

Orientational ordering and dynamics in the columnar phase of a discotic liquid crystal studied by deuteron NMR spectroscopy  

Microsoft Academic Search

We report on a deuteron NMR study of quadrupolar splittings and spin-lattice relaxation times T1Q and T1Z as a function of temperature and at two different Larmor frequencies in the columnar phase of hexakis(n-hexyloxy)triphenylene (HAT6). The additive potential method is used to model the quadrupolar splittings, from which the potential of mean torque is parameterized, and the order parameter tensor

X. Shen; Ronald Y. Dong; N. Boden; R. J. Bushby; P. S. Martin; A. Wood

1998-01-01

97

Magnetic field induced by vacuum polarization in de Sitter spacetime  

SciTech Connect

We derive the effective Lagrangian of a magnetic field in the context of amassless scalar QED coupled to gravity in de Sitter spacetime. It is found thatthe magnetic field is produced at the beginning of the inflation in a minimallycoupled scalar QED, and that the intensity /ital B/ is proportional to/ital eH//sup 2/ (/ital H/ is the Hubble constant). When/ital H/=10/sup 15/ GeV, /ital B//similar to/1.3/times/10/sup 47/ G.

Kawati, S.; Kokado, A.

1989-06-15

98

Magnetic-field-induced structural transitions in a ferrofluid emulsion  

NASA Astrophysics Data System (ADS)

A ferrofluid emulsion, subjected to a slowly increasing magnetic field, exhibits a complicated structural behavior: a gas of Brownian particles changes to columnar solid structures due to induced dipole interaction. Two transition (intermediate) structural regimes are observed: (i) randomly distributed chains and particles and (ii) distinct thin columns and randomly distributed chains and particles. Three structural transition magnetic fields are found, one marking each structural transition, from the initial to the final structural regime. A structural diagram of the structural transition magnetic fields, HC, versus particle volume fractions, ?, is constructed experimentally. Theoretical models of scaling calculations, based upon the dominant magnetic interaction in each structural regime, give the three structural transition magnetic-field relations as HC1~?-1/2, HC2~?-1/4, and HC3~(??/G2)exp(?G/ ?(?/2)), where ?=0.39 and G=0.29 for our sample. The final end shape of columns and the relative position between columns show that the end-end repulsion between chains is important in the structural formation.

Ivey, Mark; Liu, Jing; Zhu, Yun; Cutillas, Serge

2001-01-01

99

Magnetic-field-induced antiferromagnetism in the Kondo lattice  

E-print Network

The half-filled Kondo lattice model, augmented by a Zeeman term, serves as a useful model of a Kondo insulator in an applied magnetic field. A variational mean field analysis of this system on a square lattice, backed up ...

Beach, Kevin S. D. (Kevin Stuart David), 1975-

2004-01-01

100

Characterization of quantum algorithms by quantum process tomography using quadrupolar spins in solid-state nuclear magnetic resonance.  

PubMed

NMR quantum computing with qubit systems represented by nuclear spins (I=12) in small molecules in liquids has led to the most successful experimental quantum information processors so far. We use the quadrupolar spin-32 sodium nuclei of a NaNO3 single crystal as a virtual two-qubit system. The large quadrupolar coupling in comparison with the environmental interactions and the usage of strongly modulating pulses allow us to manipulate the system fast enough and at the same time keeping the decoherence reasonably slow. The experimental challenge is to characterize the "calculation" behavior of the quantum processor by process tomography which is here adapted to the quadrupolar spin system. The results of a selection of quantum gates and algorithms are presented as well as a detailed analysis of experimental results. PMID:15974729

Kampermann, H; Veeman, W S

2005-06-01

101

DFT 2H quadrupolar coupling constants of ruthenium complexes: a good probe of the coordination of hydrides in conjuction with experiments.  

PubMed

Transition metal (TM) hydrides are of great interest in chemistry because of their reactivity and their potential as catalysts for hydrogenation reactions. 2H solid-state NMR can be used in order to get information about the local environment of hydrogen atoms, and more particularly the coordination mode of hydrides in such complexes. In this work we will show that it is possible to establish at the level of density functional theory (DFT) a viable methodological strategy that allows the determination of 2H NMR parameters, namely the quadrupolar coupling constant (C(Q)) respectively the quadrupolar splitting (deltanuQ) and the asymmetry parameter (etaQ). The reliability of the method (B3PW91-DFT) and basis set effects have been first evaluated for simple organic compounds (benzene and fluorene). A good correlation between experimental and theoretical values is systematically obtained if the large basis set cc-pVTZ is used for the computations. 2H NMR properties of five mononuclear ruthenium complexes (namely Cp*RuD3(PPh3), Tp*RuD(THT)2, Tp*RuD(D2)(THT) and Tp*RuD(D2)2 and RuD2(D2)2(PCy3)2) which exhibit different ligands and hydrides involved in different coordination modes (terminal-H or eta2-H2), have been calculated and compared to previous experimental data. The results obtained are in excellent agreement with experiments. Although 2H NMR spectra are not always easy to analyze, assistance by quantum chemistry calculations allows unambiguous assignment of the signals of such spectra. As far as experiments can be achieved at very low temperatures in order to avoid dynamic effects, this hybrid theoretical/experimental tool may give useful insights in the context of the characterization of ruthenium surfaces or nanoparticles with solid-state NMR. PMID:19842483

del Rosal, Iker; Gutmann, Torsten; Maron, Laurent; Jolibois, Franck; Chaudret, Bruno; Walaszek, Bernadeta; Limbach, Hans-Heinrich; Poteau, Romuald; Buntkowsky, Gerd

2009-07-21

102

A NON-RADIAL ERUPTION IN A QUADRUPOLAR MAGNETIC CONFIGURATION WITH A CORONAL NULL  

SciTech Connect

We report one of the several homologous non-radial eruptions from NOAA active region (AR) 11158 that are strongly modulated by the local magnetic field as observed with the Solar Dynamic Observatory. A small bipole emerged in the sunspot complex and subsequently created a quadrupolar flux system. Nonlinear force-free field extrapolation from vector magnetograms reveals its energetic nature: the fast-shearing bipole accumulated {approx}2 Multiplication-Sign 10{sup 31} erg free energy (10% of AR total) over just one day despite its relatively small magnetic flux (5% of AR total). During the eruption, the ejected plasma followed a highly inclined trajectory, over 60 Degree-Sign with respect to the radial direction, forming a jet-like, inverted-Y-shaped structure in its wake. Field extrapolation suggests complicated magnetic connectivity with a coronal null point, which is favorable of reconnection between different flux components in the quadrupolar system. Indeed, multiple pairs of flare ribbons brightened simultaneously, and coronal reconnection signatures appeared near the inferred null. Part of the magnetic setting resembles that of a blowout-type jet; the observed inverted-Y structure likely outlines the open field lines along the separatrix surface. Owing to the asymmetrical photospheric flux distribution, the confining magnetic pressure decreases much faster horizontally than upward. This special field geometry likely guided the non-radial eruption during its initial stage.

Sun Xudong; Hoeksema, J. Todd; Liu Yang; Hayashi, Keiji [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States); Chen Qingrong, E-mail: xudong@sun.stanford.edu [Department of Physics, Stanford University, Stanford, CA 94305 (United States)

2012-10-01

103

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

NASA Astrophysics Data System (ADS)

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 (00\\frac{1}{2}) component of the magnetic order exhibits a Brillouin type increase below the orbital ordering temperature TQ, 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 TQ.

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

2012-02-01

104

Heteronuclear and quadrupolar second moment determination of the NQR line of 127I in NaIO4.  

PubMed

This work reports on a theoretical expression of the heteronuclear dipolar second moment (M2IS) of a NQR line of spin 5/2 nuclei. The result is applied to obtain M2IS for the resonance line of 127I in NaIO4, and in addition, an indirect determination of the quadrupolar second moment is given. PMID:10023847

Azurmendi, H F; Nagel, O A; Ramia, M E

1998-12-01

105

The Powering Source and Origin of the Quadrupolar Molecular Outflow in L723  

NASA Astrophysics Data System (ADS)

We present the results of single-dish observations of CS J = 2-1 and J = 3-2 and interferometric observations of CO J = 1-0 toward the center of the quadrupolar molecular outflow in L723. We have detected a compact CS condensation having a size of 0.04 pc and a mass of 0.55 M? toward the northeastern radio continuum source VLA 2 (AER91 2). The CO outflow also shows the distribution centered at VLA 2. These results suggest that the source VLA 2 is the young stellar object that is powering the conspicuous molecular outflow system. On the other hand, there is no enhancement in the CS intensity or the CO outflow distribution toward the southwestern radio continuum source VLA 1 (AER91 1), indicating that the source VLA 1 does not contribute to the morphology of the quadrupolar outflow in L723. The CO distribution observed with the interferometer delineates the western edge of the blue lobe and the northeastern edge of the red lobe revealed in the single-dish map, suggesting that the outflow in L723 is a single bipolar outflow with a wide opening angle of 120°-170° rather than two independent outflows. We found signs of interaction between the blueshifted outflow and the dense ambient gas: (1) there is a compact CS clump blueshifted by ~1 km s-1, the distribution of which shows anticorrelation with the blueshifted CO outflow; (2) both CS and NH3 spectra show the line broadening toward the blueshifted clump; and (3) there is a temperature enhancement at the boundary of the blueshifted clump of CS emission. It is likely that such interaction with the dense ambient gas has the increased opening angle of the outflow, which accounts for the quadrupolar morphology. Based on observations made at Nobeyama Radio Observatory (NRO). The Nobeyama Radio Observatory is a branch of the National Astronomical Observatory, an interuniversity research institute operated by the Ministry of Education, Science, Sport, and Culture, Japan.

Hirano, Naomi; Hayashi, Saeko S.; Umemoto, Tomofumi; Ukita, Nobuharu

1998-09-01

106

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

PubMed

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 (7)Li 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. PMID:23151490

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

2012-12-01

107

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

NASA Astrophysics Data System (ADS)

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.

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

1993-06-01

108

Bis-pyridinium quadrupolar derivatives. High Stokes shift selective probes for bio-imaging  

NASA Astrophysics Data System (ADS)

We describe the design, synthesis and characterization of five high Stokes shift quadrupolar heteroaryl compounds suitable as fluorescent probes in bio-imaging. In particular, we characterize the photophysical properties and the intracellular localization in Human Umbilical Vein Endothelial Cells (HUVEC) and Human Mesenchymal Stem Cells (HMSCs) for each dye. We show that, amongst all of the investigated derivatives, the 2,5-bis[1-(4-N-methylpyridinium)ethen-2-yl)]- N-methylpyrrole salt is the best candidates as selective mitochondrial tracker. Finally, we recorded the full emission spectrum of the most performing - exclusively mitochondrial selective - fluorescent probe directly from HUVEC stained cells. The emission spectrum collected from the stained mitochondria shows a remarkably more pronounced vibronic structure with respect to the emission of the free fluorophore in solution.

Salice, Patrizio; Versari, Silvia; Bradamante, Silvia; Meinardi, Francesco; Macchi, Giorgio; Pagani, Giorgio A.; Beverina, Luca

2013-11-01

109

Quadrupolar effects in PrCu{sub 2}Si{sub 2}  

SciTech Connect

As part of a systematic study of the crystal field (CF) potential in RCu{sub 2}Si{sub 2} compounds (R = Ce, Pr, Nd, Tb, Ho, Er) using inelastic neutron scattering, we have determined the CF level scheme and potential in the antiferromagnet PrCu{sub 2}Si{sub 2} both above and below T{sub N}. There have been recent speculations that the quadrupole moment of PrCu{sub 2}Si{sub 2} has been quenched by the quadrupolar Kondo effect. Using the CF potential derived from our results, we have calculated the quadrupole moment Q{sub 2} of PrCu{sub 2}Si{sub 2} and compared it to the other members of the RCu{sub 2}Si{sub 2} series. The temperature dependence of the quadrupole moment of PrCu{sub 2}Si{sub 2} is significantly weaker-than all the other compounds eg. it is approximately five times smaller than HoCu{sub 2}Si{sub 2}. Therefore, it is the CF potential which is responsible for quenching Q{sub 2} at low temperature rather than a quadrupolar Kondo effect. Furthermore, the CF Schottky contribution to C/T {nu} T{sup 2} is approximately linear above T{sub N} and explains the anomalously high linear term in the specific heat. However, the evolution of the CF potential across the rare earth series provides evidence of an enhanced hybridization contribution to the CF potential of PrCu{sub 2}Si{sub 2}, intermediate between the heavy fermion CeCu{sub 2}Si{sub 2} and the other rare earth compounds.

Osborn, R. [Argonne National Lab., IL (United States); Goremychkin, E.A. [Rutherford Appleton Lab., Chilton (United Kingdom). ISIS Science Div.

1994-05-01

110

Combining STMAS and CRAMPS NMR spectroscopy: High-resolution HETCOR NMR spectra of quadrupolar and 1H nuclei in solids  

NASA Astrophysics Data System (ADS)

High-resolution two-dimensional (2D) heteronuclear correlation spectra between half-integer quadrupolar and 1H nuclei have been obtained combining Satellite Transition Magic-Angle Spinning (STMAS) and wPMLG3 CRAMPS methods. The experiments use split-t 1 versions of DQ/DQF-STMAS adapted to 3/2 and 5/2 spins to obtain a 23Na and 27Al isotropic dimension, respectively. Transfer of magnetization from quadrupolar nuclei to protons has been achieved by cross-polarization, and high-resolution 1H spectra have been recorded using the wPMLG3 decoupling during the t 2 evolution period. The performance of the pulse sequences have been tested on the templated microporous aluminophosphate IST-1 and trisodium citrate employing a B0 field of 9.4 T.

Siegel, Renée; Rocha, João; Mafra, Luís

2009-03-01

111

Population and coherence transfer induced by double frequency sweeps in half-integer quadrupolar spin systems.  

PubMed

We have recently shown that the sensitivity of single- and multiple-quantum NMR experiments of half-integer (N/2) quadrupolar nuclei can be increased significantly by introducing so-called double frequency sweeps (DFS) in various pulse schemes. These sweeps consist of two sidebands generated by an amplitude modulation of the RF carrier. Using a time-dependent amplitude modulation the sidebands can be swept through a certain frequency range. Inspired by the work of Vega and Naor (J. Chem. Phys. 75, 75 (1981)), this is used to manipulate +/-(m - 1) <--> +/-m (3/2 < or = m < or = N/2) satellite transitions in half-integer spin systems simultaneously. For (23)Na (I = 3/2) and (27)Al (I = 5/2) spins in single crystals it proved possible to transfer the populations of the outer +/-m spin levels to the inner +/-1/2 spin levels. A detailed analysis shows that the efficiency of this process is a function of the adiabaticity with which the various spin transitions are passed during the sweep. In powders these sweep parameters have to be optimized to satisfy the appropriate conditions for a maximum of spins in the powder distribution. The effects of sweep rate, sweep range, and RF field strength are investigated both numerically and experimentally. Using a DFS as a preparation period leads to significantly enhanced central transition powder spectra under both static and MAS conditions, compared to single pulse excitation. DFSs prove to be very efficient tools not only for population transfer, but also for coherence transfer. This can be exploited for the multiple- to single-quantum transfer in MQMAS experiments. It is demonstrated, theoretically and experimentally, that DFSs are capable of transferring both quintuple-quantum and triple-quantum coherence into single-quantum coherence in I = 5/2 spin systems. This leads to a significant enhancement in signal-to-noise ratio and strongly reduces the RF power requirement compared to pulsed MQMAS experiments, thus extending their applicability. This is demonstrated by (27)Al 3QMAS experiments on 9Al(2)O(3). 2B(2)O(3) and the mineral andalusite. In the latter compound, Al experiences a quadrupolar-coupling constant of 15.3 MHz in one of the sites. Finally a 5QMAS spectrum on 9Al(2)O(3). 2B(2)O(3) demonstrates the sensitivity enhancement of this experiment using a double frequency sweep. PMID:11097810

Iuga, D; Schäfer, H; Verhagen, R; Kentgens, A P

2000-12-01

112

K-39 quadrupolar and chemical shift tensors for organic potassium complexes and diatomic molecules.  

PubMed

Solid-state potassium-39 NMR spectra of two potassium complexes of crown-ether-based organic ligands (1.KI and 2) have been acquired at 11.75 and 21.1 T and interpreted to provide information on the 39K quadrupolar and chemical shift tensors. The analyses reveal a large potassium chemical shift tensor span of 75+/-20 ppm for 1.KI. This appears to be the first such measurement for potassium in an organic complex, thereby suggesting the utility of potassium chemical shift tensors for characterizing organic and biomolecular K+ binding environments. Compound 2 exhibits a cation-pi interaction between K+ and a phenyl group, and therefore, the 39K NMR tensors obtained for this compound must be partly representative of this interaction. Analyses of potassium-39 spin-rotation data for gaseous 39K19F and 39K35Cl available from molecular beam experiments performed by Cederberg and co-workers reveal the largest potassium CS tensor spans known to date, 84.39 and 141 ppm, respectively. Collectively, the results obtained highlight the potential of ultrahigh-field potassium-39 solid-state NMR spectroscopy and, in particular, the wide range of the anisotropy of the potassium CS tensor when organic and diatomic systems are considered. PMID:18020321

Lee, Philip K; Chapman, Rebecca P; Zhang, Lei; Hu, Jiaxin; Barbour, Leonard J; Elliott, Elizabeth K; Gokel, George W; Bryce, David L

2007-12-20

113

Electrical Nuclear Quadrupolar Interaction of ZINC-67 in a Single Crystal of Zinc.  

NASA Astrophysics Data System (ADS)

The nuclear quadrupolar coupling of ('67)Zn in a single crystal of zinc has been studied using the techniques of nuclear acoustic resonance (NAR) and nuclear magnetic resonance (NMR) at low temperatures. NAR, which is an attractive way of doing resonance experiments, is analogous to NMR except in the fact that we use phonons instead of photons to induce transitions thereby avoiding the skin -depth problems met when we do NMR in single metallic crystal. While our NAR experiments were unfruitful mainly due to the large magnetoresistance effects shown by zinc at low temperatures, we were able to circumvent these problems in our NMR experiments by using a time-sharing spectrometer which did not require modulation of the magnetic field. This way, we studied the I(,z) = 1/2 to I(,z) = -1/2 magnetic resonance transition of the I = 5/2 ground state of ('67)Zn in a single crystal of zinc metal as a function of crystal orientation in a magnetic field of 72 kilogauss. The small frequency deviation versus crystal orientation has been used to evaluate the electric quadrupole interaction e('2)qQ/h as 12.19(2) Mhz, the isotropic Knight shift as 0.236(6)% and the anisotropic Knight shift as 0.013(2)% at 4.2(DEGREES)K.

Goyette, Jacques

114

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

E-print Network

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.

Don Melrose

2004-03-02

115

Structural Instability of the Charge Ordered Compound Nd0.5Sr0.5MnO3 under a Magnetic Field  

NASA Astrophysics Data System (ADS)

We report an anomalous magnetostriction behavior of the charge ordered compound Nd0.5Sr0.5MnO3. We have found that the applied magnetic field not only gives rise to a large negative magnetoresistance but also produces a huge positive magnetovolume effect. This unusual effect is explained considering that the applied magnetic field induces a structural transition at which the volume drastically increases. This effect is also seen in the anisotropic magnetostriction which shows clear anomalies at the field induced transition.

Mahendiran, R.; Ibarra, M. R.; Maignan, A.; Millange, F.; Arulraj, A.; Mahesh, R.; Raveau, B.; Rao, C. N. R.

1999-03-01

116

Spectroscopic characterization and modeling of quadrupolar charge-transfer dyes with bulky substituents.  

PubMed

Joint experimental and theoretical work is presented on two quadrupolar D-?-A-?-D chromophores characterized by the same bulky donor (D) group and two different central cores. The first chromophore, a newly synthesized species with a malononitrile-based acceptor (A) group, has a V-shaped structure that makes its absorption spectrum very broad, covering most of the visible region. The second chromophore has a squaraine-based core and therefore a linear structure, as also evinced from its absorption spectra. Both chromophores show an anomalous red shift of the absorption band upon increasing solvent polarity, a feature that is ascribed to the large, bulky structure of the molecules. For these molecules, the basic description of polar solvation in terms of a uniform reaction field fails. Indeed, a simple extension of the model to account for two independent reaction fields associated with the two molecular arms quantitatively reproduces the observed linear absorption and fluorescence as well as fluorescence anisotropy spectra, fully rationalizing their nontrivial dependence on solvent polarity. The model derived from the analysis of linear spectra is adopted to predict nonlinear spectra and specifically hyper-Rayleigh scattering and two-photon absorption spectra. In polar solvents, the V-shaped chromophore is predicted to have a large HRS response in a wide spectral region (approximately 600-1300 nm). Anomalously large and largely solvent-dependent HRS responses for the linear chromophores are ascribed to symmetry lowering induced by polar solvation and amplified in this bulky system by the presence of two reaction fields. PMID:22469003

Sissa, Cristina; Terenziani, Francesca; Painelli, Anna; Siram, Raja Bhaskar Kanth; Patil, Satish

2012-04-26

117

DFT-D study of 14N nuclear quadrupolar interactions in tetra-n-alkyl ammonium halide crystals.  

PubMed

The density functional theory-based method with periodic boundary conditions and addition of a pair-wised empirical correction for the London dispersion energy (DFT-D) was used to study the NMR quadrupolar interaction (coupling constant CQ and asymmetry parameter ?Q) of (14)N nuclei in a homologous series of tetra-n-alkylammonium halides (C(x)H(2x+1))4N(+)X(-) (x = 1-4), (X = Br, I). These (14)N quadrupolar properties are particularly challenging for the DFT-D computations because of their very high sensitivity to tiny geometrical changes, being negligible for other spectral property calculations as, for example, NMR (14)N chemical shift. In addition, the polarization effect of the halide anions in the considered crystal mesophases combines with interactions of van der Waals type between cations and anions. Comparing experimental and theoretical results, the performance of PBE-D functional is preferred over that of B3LYP-D. The results demonstrated a good transferability of the empirical parameters in the London dispersion formula for crystals with two or more carbons per alkyl group in the cations, whereas the empirical corrections in the tetramethylammonium halides appeared to be inappropriate for the quadrupolar interaction calculation. This is attributed to the enhanced cation-anion attraction, which causes a strong polarization at the nitrogen site. Our results demonstrated that the (14)N CQ and ?Q are predominantly affected by the molecular structures of the cations, adapted to the symmetry of the anion arrangements. The long-range polarization effect of the surrounding anions at the target nitrogen site becomes more important for cells with lower spatial symmetry. PMID:24758512

Dib, Eddy; Alonso, Bruno; Mineva, Tzonka

2014-05-15

118

Counterion surface diffusion in a lyotropic mesophase. A sup 23 Na two-dimensional quadrupolar echo NMR relaxation study  

SciTech Connect

In the first systematic application of the two-dimensional quadrupolar echo (2DQE) method, we study the {sup 23}Na NMR relaxation behavior of counterions in the reversed hexagonal mesophase of the AOT/D{sub 2}O/isooctane system, consisting of long cylindrical aggregates with the water and ions on the inside. Using a combination of relaxation experiments, performed on magnetically aligned samples, we determine the three spectral densities at two sample orientations. The orientational dependence of the spectra densities allows us to separate contributions from different types of molecular motion.

Furo, I.; Halle, B.; Quist, P.O.; Wong, Tuck C. (Univ. of Lund (Sweden))

1990-03-22

119

Application of static microcoils and WURST pulses for solid-state ultra-wideline NMR spectroscopy of quadrupolar nuclei  

NASA Astrophysics Data System (ADS)

The uses of microcoils and WURST pulses for acquiring ultra-wideline (UW) NMR spectra of half-integer quadrupolar nuclei are explored. Using large rf field strengths or frequency-swept pulses, UW spectra (breadth > 300 kHz) can be acquired without changing the transmitter frequency. The efficiency of UWNMR spectroscopy improves for both microcoil and WURST pulse experiments compared to rectangular-pulse experiments using a 4.0 mm coil. Microcoils are also used to acquire UW spectra of an unreceptive nucleus ( 91Zr) and a spectrum comprised of both central and satellite transitions ( 59Co).

Tang, Joel A.; O'Dell, Luke A.; Aguiar, Pedro M.; Lucier, Bryan E. G.; Sakellariou, Dimitris; Schurko, Robert W.

2008-12-01

120

Orbital Ordering and Magnetic Field Effect in MnV{sub 2}O{sub 4}  

SciTech Connect

We studied the structural properties of an orbital-spin-coupled spinel oxide, MnV{sub 2}O{sub 4}, mainly by single-crystal x-ray diffraction measurement. It was found that a structural phase transition from cubic to tetragonal and ferrimagnetic ordering occur at the same temperature (T{sub s},T{sub N}=57 K). The structural phase transition was induced also by magnetic field above T{sub s}. In addition, magnetic-field-induced alignment of tetragonal domains results in large magnetostriction below T{sub s}. We also found that the structural phase transition is caused by the antiferro-type ordering of the V t{sub 2g} orbitals.

Suzuki, T.; Katsumura, M. [Department of Physics, Waseda University, Tokyo 169-8555 (Japan); Taniguchi, K.; Arima, T. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Katsufuji, T. [Department of Physics, Waseda University, Tokyo 169-8555 (Japan); Kagami Memorial Laboratory for Material Science and Technology, Waseda University, Tokyo 169-0051 (Japan)

2007-03-23

121

Impurity model for Mn ions: Possibility of charge order and lattice distortions  

SciTech Connect

Mixed valent manganese ions play an important role in the magnetoresistance of LaMnO{sub 3}-based systems. We consider a Mn impurity with the Mn{sup 4+} represented by a spin S=3/2 (three localized 3d-t{sub 2g} electrons) and the Mn{sup 3+} configuration having an additional localized 3d-e{sub g} electron to form a total spin (S+1/2). The e{sub g} electron hybridizes with conduction electrons (representing the crystal), giving rise to a quadrupolar Kondo effect. The formation of the quadrupolar singlet interferes with the usual spin Kondo effect. Using the noncrossing diagram approximation, we calculate the ground state energy, valence, charge susceptibility, and the quadrupolar susceptibility as a function of the energy of the e{sub g} level for H{r_arrow}0 and compare it to results for H=0 and the ferromagnetic lattice. Both, the charge and quadrupolar susceptibilities, are larger in the spin-polarized limit, indicating that this state is more favorable for charge order and lattice distortions. {copyright} {ital 1999 American Institute of Physics.}

Schlottmann, P. [Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States)] [Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States)

1999-04-01

122

Efficient symmetry-based homonuclear dipolar recoupling of quadrupolar spins: double-quantum NMR correlations in amorphous solids.  

PubMed

We report novel symmetry-based pulse sequences for exciting double-quantum (2Q) coherences between the central transitions of half-integer spin quadrupolar nuclei in the NMR of rotating solids. Compared to previous 2Q-recoupling techniques, numerical simulations and 23Na and 27Al NMR experiments on Na2SO4 and the open-framework aluminophosphate AlPO-CJ19 verify that the new dipolar recoupling schemes display higher robustness to both radio-frequency field inhomogeneity and to spreads in resonance frequencies. These advances allowed for the first demonstration of 2Q-recoupling in an amorphous solid for revealing its intermediate-range structural features, in the context of mapping 27Al-27Al connectivities between the aluminium polyhedra (AlO4, AlO5 and AlO6) of a lanthanum aluminate glass (La0.18Al0.82O1.5). PMID:18989475

Lo, Andy Y H; Edén, Mattias

2008-11-28

123

Low Temperature Solid-State NMR Experiments of Half-Integer Quadrupolar Nuclides: Caveats and Data Analysis  

SciTech Connect

Solid-state NMR spectroscopy of half-integer quadrupolar metals has received a lot of interest recently with the advent of new methodologies and higher magnetic fields. We present here the extension of our previous low temperature method to an 18.8 T system. This new probe entailed a total redesign including a cross coil and variable capacitors that are operational at cryogenic temperatures. The limitations to sensitivity are also discussed; including a new diode network, the utilization of a cryogenic band pass filter, and the consequences of the RF profiles of the coil. Further, details of the spectroscopy of a spin 5/2 metal in a protein are discussed, such as the observation of the outer transitions and how to distinguish them from the desired {+-}1/2 transition

Lipton, Andrew S.; Heck, Robert W.; Sears, Jesse A.; Ellis, Paul D.

2004-03-01

124

A novel method for determining and improving the quality of a quadrupolar fiber gyro coil under temperature variations.  

PubMed

We introduce a parameter called pointing error thermal sensitivity (PETS) for quantitatively determining the quality of a quadrupolar (QAD) fiber coil under radial temperature variations. We show both analytically and experimentally that the pointing error of a fiber gyro incorporating the fiber coil is linearly proportional to the final radial thermal gradient on the coil, with PETS as the proportional constant. We further show that PETS is linearly proportional to another parameter called effective asymmetric length of the coil. By thermally inducing different radial thermal gradients on the fiber coil and measuring the corresponding pointing errors in a gyroscopic measurement setup, we can confidently determine the PETS of the fiber coil and its associated effective asymmetric length caused by imperfections in coil winding. Consequently, we are able to precisely trim the coil to achieve best thermal performance. PMID:23389233

Li, Zhihong; Meng, Zhuo; Liu, Tiegen; Yao, X Steve

2013-01-28

125

Spin-locking of half-integer quadrupolar nuclei in nuclear magnetic resonance of solids: creation and evolution of coherences.  

PubMed

Spin-locking of half-integer quadrupolar nuclei, such as 23Na (I=3/2) and 27Al (I=5/2), is of renewed interest owing to the development of variants of the multiple-quantum and satellite-transition magic angle spinning (MAS) nuclear magnetic resonance experiments that either utilize spin-locking directly or offer the possibility that spin-locked states may arise. However, the large magnitude and, under MAS, the time dependence of the quadrupolar interaction often result in complex spin-locking phenomena that are not widely understood. Here we show that, following the application of a spin-locking pulse, a variety of coherence transfer processes occur on a time scale of approximately 1/omegaQ before the spin system settles down into a spin-locked state which may itself be time dependent if MAS is performed. We show theoretically for both spin I=3/2 and 5/2 nuclei that the spin-locked state created by this initial rapid dephasing typically consists of a variety of single- and multiple-quantum coherences and nonequilibrium population states and we discuss the subsequent evolution of these under MAS. In contrast to previous work, we consider spin-locking using a wide range of radio frequency field strengths, i.e., a range that covers both the "strong-field" (omega1 > omegaQPAS and "weak-field" (omega1 < omegaQPAS limits. Single- and multiple-quantum filtered spin-locking experiments on NaNO2, NaNO3, and Al(acac)3, under both static and MAS conditions, are used to illustrate and confirm the results of the theoretical discussion. PMID:15268416

Ashbrook, Sharon E; Wimperis, Stephen

2004-02-01

126

Non-Spherical Source-Surface Model of the Corona and Heliosphere for a Quadrupolar Main Field of the Sun  

NASA Astrophysics Data System (ADS)

Different methods of modeling the coronal and heliospheric magnetic field are conveniently visualized and intercompared by applying them to ideally axisymmetric field models. Thus, for example, a dipolar main B field with its moment parallel to the Sun's rotation axis leads to a flat heliospheric current sheet. More general solar main B fields (still axisymmetric about the solar rotation axis for simplicity) typically lead to cone-shaped current sheets beyond the source surface (and presumably also in MHD models). As in the dipolar case [Schulz et al., Solar Phys., 60, 83-104, 1978], such conical current sheets can be made realistically thin by taking the source surface to be non-spherical in a way that reflects the underlying structure of the Sun's main B field. A source surface that seems to work well in this respect [Schulz, Ann. Geophysicae, 15, 1379-1387, 1997] is a surface of constant F = (1/r)kB, where B is the scalar strength of the Sun's main magnetic field and k (~ 1.4) is a shape parameter. This construction tends to flatten the source surface in regions where B is relatively weak. Thus, for example, the source surface for a dipolar B field is shaped somewhat like a Rugby football, whereas the source surface for an axisymmetric quadrupolar B field is similarly elongated but somewhat flattened (as if stuffed into a pair of co-axial cones) at mid-latitudes. A linear combination of co-axial dipolar and quadrupolar B fields generates a somewhat apple-shaped source surface. If the region surrounded by the source surface is regarded as current-free, then the source surface itself should be (as nearly as possible) an equipotential surface for the corresponding magnetic scalar potential (expanded, for example, in spherical harmonics). More generally, the mean-square tangential component of the coronal magnetic field over the source surface should be minimized with respect to any adjustable parameters of the field model. The solar wind should then flow not quite radially, but rather in a straight line along the outward normal to the source surface, and the heliospheric B field should follow a corresponding generalization of Parker's spiral [Levine et al., Solar Phys., 77, 363-392, 1982]. In this work the above program is implemented for a Sun with an axisymmetric but purely quadrupolar main magnetic field. Two heliospheric current sheets emanate from circular neutral lines at mid-latitudes on the corresponding source surface. However, because the source surface is relatively flattened in regions where these neutral lines appear, the radial component of the heliospheric B field at r ~ 1 AU and beyond is much more nearly latitude-independent in absolute value than one would expect from a model based on a spherical source surface.

Schulz, M.

2008-05-01

127

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

SciTech Connect

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.

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

128

Distinct origins of magnetic -field -induced resistivity irreversibility in two manganites with similar ground states : Pr0.5Sr0.41Ca0.09MnO3 and La0.5Ca0.5MnO3  

Microsoft Academic Search

Our investigation of the magnetotransport in two charge ordered mangan- ites with similar magnetic ground states reveals that the origin of magne- toresistance can not be concluded from the isofield resistivity, ?(T, con- stant H), measurements alone. Both Pr0.5Sr0.41Ca0.09MnO3 (PrSrCa) and La0.5Ca0.5MnO3 (LaCa) show a ferromagnetic transition (TC = 260 K for PrSrCa, 230 K for LaCa) followed by an

R. Mahendiran; A. Maignan; C. Martin; M. Hervieu; B. Raveau

129

Spin-orbit coupling in d2 ordered double perovskites  

NASA Astrophysics Data System (ADS)

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.

Chen, Gang; Balents, Leon

2011-09-01

130

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

E-print Network

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.

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

2014-08-21

131

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

E-print Network

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 d...

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

2014-01-01

132

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

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

133

Connectivity and proximity between quadrupolar nuclides in oxide glasses: insights from through-bond and through-space correlations in solid-state NMR.  

PubMed

The connectivity and proximity among framework cations and anions in covalent oxide glasses yields unique information whereby their various transport and thermodynamic properties can be predicted. Recent developments and advances in the reconstruction of anisotropic spin interactions among quadrupolar nuclides (spin > (1)/(2)) in solid-state NMR shed light on a new opportunity to explore local connectivity and proximity in amorphous solids. Here, we report the 2D through-bond (J-coupling) and through-space (dipolar coupling) correlation NMR spectra for oxide glasses where previously unknown structural details about the connectivity and proximity among quadrupolar nuclides ((27)Al, (17)O) are determined. Nonbridging oxygen peaks in Ca-aluminosilicate glasses with distinct connectivity, such as Ca-O-Al and Al-O-(Al, Si) are well distinguished in {(17)O}(27)Al solid HMQC NMR spectra. Both peaks shift to a lower frequency in direct and indirect dimensions upon the addition of Si to the Ca-aluminate glasses. The 2D (27)Al double quantum magic angle spinning NMR spectra for Mg-aluminoborate glasses indicate the preferential proximity between ([4])Al and ([5])Al leading to the formation of correlations peaks such as ([4])Al-([4])Al, ([4])Al-([5])Al, and ([5])Al-O-([5])Al. A fraction of the ([6])Al-([6])Al correlation peak is also noticeable while that of ([4,5])Al-([6])Al is missing. These results suggest that ([6])Al is likely to be isolated from the ([4])Al and ([5])Al species, forming ([6])Al clusters. The experimental realization of through-bond and through-space correlations among quadrupolar nuclides in amorphous materials suggests a significant deviation from the random distribution among framework cations and a spatial heterogeneity due to possible clustering of framework cations in the model oxide glasses. PMID:19296644

Lee, Sung Keun; Deschamps, Michael; Hiet, Julien; Massiot, Dominique; Park, Sun Young

2009-04-16

134

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

NASA Astrophysics Data System (ADS)

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.

Matt, S.; Balick, B.

2002-12-01

135

Magnetic Field-Induced Giant Enhancement of Electron-Phonon Energy Transfer in Strongly Disordered Conductors  

NASA Astrophysics Data System (ADS)

Relaxation of soft modes (e.g., charge density in gated semiconductor heterostructures, spin density in the presence of magnetic field) slowed down by disorder may lead to giant enhancement of energy transfer (cooling power) between overheated electrons and phonons at low bath temperature. We show that in strongly disordered systems with time-reversal symmetry broken by external or intrinsic exchange magnetic field the cooling power can be greatly enhanced. The enhancement factor as large as 102 at magnetic field B˜10T in 2D InSb films is predicted. A similar enhancement is found for the ultrasound attenuation.

Shtyk, A. V.; Feigel'man, M. V.; Kravtsov, V. E.

2013-10-01

136

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

E-print Network

that are several millimeters thick. r 2006 Elsevier Ltd. All rights reserved. Keywords: Collagen; Confocal, which vary in the length of helix and nature and size of the non-helical portions, exist in animal and supports animal cells. Type I collagen is the predominant form of collagen in animal tissue and is found

Kaufman, Laura

137

Magnetic field-induced giant enhancement of electron-phonon energy transfer in strongly disordered conductors.  

PubMed

Relaxation of soft modes (e.g., charge density in gated semiconductor heterostructures, spin density in the presence of magnetic field) slowed down by disorder may lead to giant enhancement of energy transfer (cooling power) between overheated electrons and phonons at low bath temperature. We show that in strongly disordered systems with time-reversal symmetry broken by external or intrinsic exchange magnetic field the cooling power can be greatly enhanced. The enhancement factor as large as 10(2) at magnetic field B~10 T in 2D InSb films is predicted. A similar enhancement is found for the ultrasound attenuation. PMID:24182289

Shtyk, A V; Feigel'man, M V; Kravtsov, V E

2013-10-18

138

External magnetic field-induced selective biodistribution of magnetoliposomes in mice  

NASA Astrophysics Data System (ADS)

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.

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

2012-08-01

139

Measurements of the Magnetic Field Induced by a Turbulent Flow of Liquid Metal  

E-print Network

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 is reconstructed from measurements both outside and within the flow. Differential rotation of the fluid generates a large mean toroidal magnetic field from an externally-generated axial field through the omega-effect. Mean poloidal magnetic flux is expelled from the fluid by the poloidal flow. Small-scale, time-varying magnetic field structures are generated by turbulence in the flow. The resulting magnetic power spectrum exhibits the characteristic power-law scalings expected from Kolmogorov-like turbulence with an apparent knee at the resistive dissipation scale. Large-scale velocity fluctuations create dynamic flow profiles that generate intermittent bursts of non-axisymmetric magnetic fields indicating that the transition from damped magnetic fields to growing magnetic fields is not smooth for a turbulent flow.

Nornberg, M D; Kendrick, R D; Forest, C B

2005-01-01

140

External magnetic field-induced selective biodistribution of magnetoliposomes in mice  

PubMed Central

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

2012-01-01

141

Weak extremely-low-frequency magnetic field-induced regeneration anomalies in the planarian, Dugesia tigrina  

Microsoft Academic Search

The authors recently reported that cephalic regeneration in the planarian Dugesia tigrina was significantly delayed in populations exposed continuously to combined parallel DC and AC magnetic fields. This effect was consistent with hypotheses suggesting an underlying resonance phenomenon. The authors report here, in a parallel series of investigations on the same model system, that the incidence of regeneration anomalies presenting

K. A. Jenrow; C. H. Smith; A. R. Liboff

1996-01-01

142

Magnetic Fields Induce Changes in Photosynthetic Pigments Content in Date Palm (Phoenix dactylifera L.) Seedlings  

Microsoft Academic Search

Growth, development and plants productivity are usually affected by photosynthetic pigments activity. Mag- netic fields are known to induce biochemical changes and could be used as a stimulator for growth related reactions in- cluding affecting photosynthetic pigments. The impact of magnetic field strengths on chlorophyll and carotenoids were investigated in this study through the use of date palm (Phoenix dactylifera

Faten Dhawi; Jameel M. Al-Khayri

2009-01-01

143

Polyelectrolyte Stabilized Nanowires from Fe3O4 Nanoparticles via Magnetic Field Induced  

E-print Network

effects,10,13 shape-selective14 as well as size-selective15,16 interactions, and template synthe- sis17 molecules were templated with metal nanoparticles; initially, giant DNA molecules20-22 and later "thin

Sokolov, Igor

144

Involvement of NMDA receptor in low-frequency magnetic field-induced anxiety in mice.  

PubMed

Abstract It had been reported that exposure to extremely low-frequency magnetic field (ELFMF) induces anxiety in human and rodents. Anxiety mediates via the activation of N-methyl-d-aspartate (NMDA) receptor, whereas activation of ?-aminobutyric acid (GABA) receptor attenuates the same. Hence, the present study was carried out to understand the contribution of NMDA and/or GABA receptors modulation in ELFMF-induced anxiety for which Swiss albino mice were exposed to ELFMF (50?Hz, 10?G) by subjecting them to Helmholtz coils. The exposure was for 8?h/day for 7, 30, 60, 90 and 120 days. Anxiety level was assessed in elevated plus maze, open field test and social interaction test, on 7th, 30th, 60th, 90th and 120th exposure day, respectively. Moreover, the role of GABA and glutamate in ELFMF-induced anxiety was assessed by treating mice with muscimol [0.25?mg/kg intraperitoneally (i.p.)], bicuculline (1.0?mg/kg i.p.), NMDA (15?mg/kg i.p.) and MK-801 (0.03?mg/kg i.p.), as a GABAA and NMDA receptor agonist and antagonist, respectively. Glutamate receptor agonist exacerbated while inhibitor attenuated the ELFMF-induced anxiety. In addition, levels of GABA and glutamate were determined in regions of the brain viz, cortex, striatum, hippocampus and hypothalamus. Experiments demonstrated significant elevation of GABA and glutamate levels in the hippocampus and hypothalamus. However, GABA receptor modulators did not produce significant effect on ELFMF-induced anxiety and elevated levels of GABA at tested dose. Together, these findings suggest that ELFMF significantly induced anxiety behavior, and indicated the involvement of NMDA receptor in its effect. PMID:24131395

Salunke, Balwant P; Umathe, Sudhir N; Chavan, Jagatpalsingh G

2014-12-01

145

Identification of superconducting phases in ceramic particles by magnetic field induced forces using a magnetized wire  

NASA Astrophysics Data System (ADS)

A new equipment for minority phase analysis of superconducting (SC) phases within chemically inhomogeneous ceramic grains using a high gradient magnetic field or field induced effect of torque is presented. Single grains down to 20 ?m are either captured by a magnetized iron wire or identified because of their torque movement in a pulsed magnetic field. An assembly of many hundreds of grains can be investigated for minor quantities of SC phases from 80 K up to room temperature. A maximum field of up to 100-140 mT allows us to reliably identify SC grains and evaluate their SC critical temperatures Tc. Localization of SC grains allows us to extract them for further analysis. Experiments with YBa2Cu3O2-? grains demonstrated that Tc values evaluated in such a way are rather close to those, which are determined by magnetization measurements.

Pérez, Daniel; Hulliger, Jürg

2010-06-01

146

Magnetic Field-induced Effects in Photon Scattering and Absorption by Crystals  

NASA Astrophysics Data System (ADS)

Electrons respond in a variety of ways to a steady magnetic field, and bulk material properties include helicon waves, Faraday rotation of the plane of polarization of photons and many other magneto-optic effects. Information about electrons at an atomic level of detail is obtained from Bragg diffraction, and diffraction enhanced by an atomic resonance provides information not available by any other technique in the science of materials, e.g., the direct observation of magnetic charge and anapoles. We formulate resonant Bragg diffraction from crystalline materials subject to a steady magnetic field. By way of illustration of our general findings for field-induced effects in diffraction enhanced by E1--E1 and E1--M1 resonances, we calculate unit-cell structure factors for diffraction from multiferroic gallium ferrate and anti-ferromagnetic copper oxide. In addition, we provide expressions for frequency-integrated dichroic signals conjugate to standard magneto-optic effects, such as Faraday rotation.

Lovesey, Stephen William; Balcar, Ewald

2011-06-01

147

Axion emission by magnetic-field induced conversion of longitudinal plasmons  

Microsoft Academic Search

Magnetic fields mix axions with photons, allowing for the cyclotron process e--->e-a by virtue of an intermediate plasmon even if axions do not couple to electrons at the tree level. The axion and longitudinal-plasmon dispersion relations always cross for a certain wave number, leading to a resonant enhancement of this process. Even then, however, it cannot quite compete with the

N. V. Mikheev; G. Raffelt; L. A. Vassilevskaya

1998-01-01

148

Axion emission by magnetic-field induced conversion of longitudinal plasmons  

Microsoft Academic Search

Magnetic fields mix axions with photons, allowing for the cyclotron process e\\u000a-> e + a by virtue of an intermediate plasmon even if axions do not couple to\\u000aelectrons at tree level. The axion and longitudinal-plasmon dispersion\\u000arelations always cross for a certain wave number, leading to a resonant\\u000aenhancement of this process. Even then, however, it cannot quite

N. V. Mikheev; L. A. Vassilevskaya

1998-01-01

149

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

E-print Network

Magnetic Shape Memory Alloys (MSMAs) combine shape-change/deformationrecovery abilities of heat driven conventional shape memory alloys (SMA) and magnetic field driven magnetostrictives through martensitic transformation. They are promising...

Basaran, Burak

2011-02-22

150

Magnetic-field-induced grain elongation in a medium carbon steel during its austenitic decomposition  

SciTech Connect

A 12-T magnetic field was applied during the austenitic decomposition in a medium plain carbon steel at a slow cooling rate. The magnetic field applied promotes proeutectoid ferrite grains to grow along the field direction and results in an elongated grain microstructure. The grain elongation is the result of the opposing contributions from the atomic dipolar interaction energy of Fe atoms and the interfacial energy.

Zhang, Y.D.; Esling, C.; Muller, J.; He, C.S.; Zhao, X.; Zuo, L. [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China) and LETAM, CNRS-UMR 7078, University of Metz, Ile du Saulcy, 57045 Metz (France); LETAM, CNRS-UMR 7078, University of Metz, Ile du Saulcy, 57045 Metz (France); School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China)

2005-11-21

151

Dynamo magnetic field-induced angular momentum transport in protostellar nebulae - The minimum mass protosolar nebula  

SciTech Connect

Magnetic torques can produce angular momentum redistribution in protostellar nebulas. Dynamo magnetic fields can be generated in differentially rotating and turbulent nebulas and can be the source of magnetic torques that transfer angular momentum from a protostar to a disk, as well as redistribute angular momentum within a disk. A magnetic field strength of 100-1000 G is needed to transport the major part of a protostar's angular momentum into a surrounding disk in a time characteristic of star formation, thus allowing formation of a solar-system size protoplanetary nebula in the usual minimum-mass model of the protosolar nebula. This paper examines the possibility that a dynamo magnetic field could have induced the needed angular momentum transport from the proto-Sun to the protoplanetary nebula. 32 refs.

Stepinski, T.F.; Levy, E.H. (Arizona Univ., Tucson (USA))

1990-02-01

152

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

NASA Astrophysics Data System (ADS)

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.

Brady, Megan; Laramee, Craig

2013-03-01

153

Magnetic-field-induced polarization and magnetocapacitance in quantum paraelectric EuTiO3  

Microsoft Academic Search

EuTiO3 is a quantum paraelectric as well as an antiferromagnet. The most attractive property for EuTiO3 is the magnetoelectric coupling effect. In the present work, we investigate the influence of the external fields on EuTiO3, including the electric field E and magnetic field h. The application of the electric field counteracts the quantum fluctuation and forces the system into an

S. J. Gong; Q. Jiang

2004-01-01

154

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

E-print Network

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.

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

2014-01-01

155

Magnetic-Field-Induced Stress-Birefringence in Laminate Composites of Terfenol-D and Polycarbonate  

NASA Astrophysics Data System (ADS)

The laminate composites that can show the magneto-birefringence effect are suggested and fabricated by the product of magnetostriction and stress-birefringence. Under a magnetic field no stronger than 1900 Oe, a phase difference of ~3.3? is observed for a trilayer composite Tb1-xDyxFe2-y/polycarbonate/Tb1-xDyxFe2-y with a polycarbonate layer at a size of 5 × 2.75 × 20 mm3 at room temperature, resulting in a half-wave magnetic field of no greater than 270 Oe.

Luo, Xiao-Bin; Wu, Dong; Zhang, Ning

2013-07-01

156

Magnetic field induced surface state study of conduction electron scattering in fast neutron irradiated copper  

SciTech Connect

Surface impedance oscillations were observed in fields in the range 0-45 G in the (111) plane of a high purity Cu single crystal. The experiment was conducted at a microwave frequency of 24 GHz and at liquid helium temperatures. The measured spectra showed resonances of considerable magnitude in comparison to those observed in previous works in the (111) plane of Cu. Upon accurately determining the necessary v{sub z} = 0 zone using the known Fermi surface geometry of Cu, a predetermined Fermi velocity distribution was used to identify the resonant electrons responsible for these signals. Based on this identification, a prediction was made of the resonant field peak locations as a function of magnetic field orientation. The measured peak locations differed from the predicted values by approximately 20%. To measure the change in electron-scattering rate due to a dilute concentration of Frenkel pairs, the sample was subjected to a fast-neutron fluence (E > 0.1 MeV) of 2 {times} 10{sup 15} n/cm{sup 2} and the resonance spectra remeasured. The measured anisotropy of the change in electron scattering rate induced by the Frenkel pairs has been compared to calculations from the Korringa-Kohn-Rostoker Green function extended-defect formalism. While general agreement between the scattering-rate anisotropies was found to exist, there was a marked exception to this at <111> neck point.

Gillen, T.J.

1991-01-01

157

Weak extremely-low-frequency magnetic field-induced regeneration anomalies in the planarian, Dugesia tigrina  

SciTech Connect

The authors recently reported that cephalic regeneration in the planarian Dugesia tigrina was significantly delayed in populations exposed continuously to combined parallel DC and AC magnetic fields. This effect was consistent with hypotheses suggesting an underlying resonance phenomenon. The authors report here, in a parallel series of investigations on the same model system, that the incidence of regeneration anomalies presenting as tumor-like protuberances also increases significantly (P < .001) in association with exposure to weak 60 Hz magnetic fields, with peak intensities ranging between 1.0 and 80.0 {micro}T. These anomalies often culminate in the complete disaggregation of the organism. Similar to regeneration rate effects, the incidence of regeneration anomalies is specifically dependent upon the planaria possessing a fixed orientation with respect to the applied magnetic field vectors. However, unlike the regeneration rate effects, the AC magnetic field alone, in the absence of any measurable DC field, is capable of producing these anomalies. Moreover, the incidence of regeneration anomalies follows a clear dose-response relationship as a function of AC magnetic field intensity, with the threshold for induced electric field intensity estimated at 5 {micro} V/m. The addition of either 51.1 or 78.4 {micro}T DC magnetic fields, applied in parallel combination with the AC field, enhances the appearance of anomalies relative to the 60 Hz AC field alone, but only at certain AC field intensities. Thus, whereas the previous study of regeneration rate effects appeared to involve exclusively resonance interactions, the regeneration anomalies reported here appear to result primarily from Faraday induction coupling.

Jenrow, K.A.; Smith, C.H.; Liboff, A.R. [Oakland Univ., Rochester, MI (United States). Dept. of Physics] [Oakland Univ., Rochester, MI (United States). Dept. of Physics

1996-12-31

158

Magnetic-field-induced binding of few-electron systems in shallow quantum dots  

E-print Network

Binding of few-electron systems in two-dimensional potential cavities in the presence of an external magnetic field is studied with the exact diagonalization approach. We demonstrate that for shallow cavities the few-electron system becomes bound only under the application of a strong magnetic field. The critical value of the depth of the cavity allowing the formation of a bound state decreases with magnetic field in a non-smooth fashion, due to the increasing angular momentum of the first bound state. In the high magnetic field limit the binding energies and the critical values for the depth of the potential cavity allowing the formation of a bound system tend to the classical values.

B. Szafran; S. Bednarek; F. M. Peeters

2006-06-20

159

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

Microsoft Academic Search

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

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

1999-01-01

160

Magnetic Field Induced Biochemical and Growth Changes in Date Palm Seedlings  

Microsoft Academic Search

\\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

F. Dhawi; J. M. Al-Khayri

161

Magnetic field induced ferroelectricity in copper doped CdI2 single crystals  

Microsoft Academic Search

We have discovered a new type of ferroelectricity in highly anisotropic CdI2 layered crystals doped with copper. A spontaneous electric polarization is created in result of interaction between long-range interlayer polar acoustical vibrations and magnetically oriented copper ions. The phenomenon is strongly enhanced after applying external magnetic field at liquid helium temperatures. The strongest effect has been observed in the

I. V. Kityk; S. A. Pyroha; T. Mydlarz; J. Kasperczyk; M. Czerwi?ski

1998-01-01

162

Magnetic Field-Induced Superconductivity in the Ferromagnet URhGe  

NASA Astrophysics Data System (ADS)

In several metals, including URhGe, superconductivity has recently been observed to appear and coexist with ferromagnetism at temperatures well below that at which the ferromagnetic state forms. However, the material characteristics leading to such a state of coexistence have not yet been fully elucidated. We report that in URhGe there is a magnetic transition where the direction of the spin axis changes when a magnetic field of 12 tesla is applied parallel to the crystal b axis. We also report that a second pocket of superconductivity occurs at low temperature for a range of fields enveloping this magnetic transition, well above the field of 2 tesla at which superconductivity is first destroyed. Our findings strongly suggest that excitations in which the spins rotate stimulate superconductivity in the neighborhood of a quantum phase transition under high magnetic field.

Lévy, F.; Sheikin, I.; Grenier, B.; Huxley, A. D.

2005-08-01

163

Electric and Magnetic Field Induced Insulating States in High Quality Bilayer Graphene pnp Junctions  

NASA Astrophysics Data System (ADS)

Band gap opening in bilayer graphene has generated significant interest in both technological application and fundamental research. By applying external electric and magnetic field, we observe an insulating state in our dual-gated bilayer graphene device. In addition, we also observe Quantum Hall plateaus with fractional values of e^2/h at large magnetic field, which arises from edge state equilibration at the interface of differentially doped regions, in agreement with theoretical predictions.

Jing, Lei; Velasco, Jairo; Kratz, Philip; Liu, Gang; Bao, Wenzhong; Bockrat, Marc; Lau, Chun Ning

2011-03-01

164

Transient and steady-state magnetic fields induce increased fluorodeoxyglucose uptake in the rat hindbrain.  

PubMed

We inquired into the biophysical basis of the ability of weak electromagnetic fields (EMFs) to trigger onset and offset evoked potentials, and to produce steady-state changes in the electroencephalogram (EEG). Rats were exposed to a 2.5-G, 60-Hz magnetic field and the neuroanatomical region of glucose activation associated with the effect of the field on the EEG was identified by positron emission tomography (PET) using fluorodeoxyglucose (FDG). Paired emission scans from the same animal with and without field treatment were differenced and averaged, and t values of the brain voxels computed using the pooled standard deviation were compared with a calculated critical t value to identify the field-activated voxels. Increased glucose utilization occurred in hindbrain voxels when the field was applied orthogonally to the sagittal plane, but not when the angle between the field and the sagittal plane varied randomly. Distinct FDG activation effects were observed in response to transient (both onset and offset) and steady-state magnetic stimuli. Observations of increased glucose utilization induced by magnetic stimuli and its dependence on the direction of the field suggested that signal transduction was mediated by a force detector and that the process and/or early post-transduction processing occurred in the hindbrain. PMID:21484881

Frilot, Clifton; Carrubba, Simona; Marino, Andrew A

2011-07-01

165

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

SciTech Connect

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.

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

166

Magnetic field-induced fracture changes in metastable austenites at 4. 2K  

SciTech Connect

Austenitic stainless steels have been used as structural alloys in high field superconducting magnets. Some of the candidate structural alloys for the next generation of magnetic confinement fusion reactors are of this type. In this application the alloys sustain high stresses in high strength magnetic fields at 4.2K. It is known that plastic deformation at low temperatures induces a martensitic transformation in some of these alloys and that the presence of a strong magnetic field enhances the transformation. If such potentially metastable alloys are selected for this application, their mechanical behavior under service conditions has to be examined closely. Work on the tensile behavior of 18-8 type stainless steels under conditions of cryogenic temperatures and high-strength magnetic fields indicates that the tensile behavior does not undergo large changes in an engineering sense. However, fatigue and fracture properties have not yet been examined closely. This work addresses the fracture behavior of 18-8 type austenitic alloys at 4.2K in an 8T magnetic field. The fracture toughness is found to change with the application of the magnetic field. The direction of the fracture toughness change is related to enhanced transformation due to the reduction in the stability of the alloy in the magnetic field. Materials of low stability decrease in toughness and materials of intermediate stability increase in toughness; fully stable alloys showed no change. Several mechanisms that contribute to the observed differences are identified. These include: formation of low toughness martensite regions, strain hardening rate increases due to the transformation, transformation toughening, magnetostatic interactions, and changes in the slip characteristics. The timing of the transformation influences the relative strength of the operative mechanisms and determines the direction and amount of fracture toughness change. 63 refs., 35 figs., 4 tabs.

Chan, Jin Wah.

1991-06-01

167

Examples of Hartmann-Hahn match conditions for CP/MAS between two half-integer quadrupolar nuclei.  

PubMed

Hartmann-Hahn match conditions for n2 --> M2 CP/MAS between two quadrupolar nuclei, spin-lock signal as a function of effective nutation frequency, and the correlation of effective nutation frequency and radiofrequency field strength are reported for three samples: sodium diborate (Na2B4O7), aluminum boride (AlB2), and lithiump aluminate (LiAlO2). Radiofrequency field strengths used for CP/MAS are both greater and less than the sample spinning speed of 10 kHz, resulting in the observation of both zero-quantum and double-quantum matches, which have signals of opposite sign. The match conditions for Na2B4O7 are as expected from published theory and CP/MAS experiments on spins 12 and n2 (n = 3 or 5) with quadrupole frequencies (omegaQ) large compared to the radiofrequency field strength of the CP contact pulse, consisting mainly of sideband matches at one and two times the sample spinning frequency, and the correlation of effective nutation frequency and radiofrequency field strength supports the conclusion that omegaQ is large for both 11B and 23Na. Aluminum-27 in AlB2 may have either small or intermediate omegaQ, and 7Li in LiAlO2 is proposed to have intermediate omegaQ in relation to the radiofrequency field strength, and both have curves of the spin-lock signal as a function of effective nutation frequency with central minima, differing from those of the nuclei with large omegaQ. The sign of the CP/MAS signal for AlB2 and LiAlO2 appears to vary with the CP field strengths for the two nuclei so that positive or negative signals cannot be consistently correlated with zero- or double-quantum matches. However, it is possible to assign at least some of the matches as close to integral multiples of the sample spinning frequency, and some of these are matches at greater than two times the sample spinning frequency. PMID:10388589

Eastman, M A

1999-07-01

168

Dephasing and relaxation of central hole spins by nuclear spin baths in InGaAs quantum dots: role of nuclear quadrupolar coupling  

NASA Astrophysics Data System (ADS)

Single electron or hole spins in III-V semiconductor quantum dots (QDs) are promising candidates for solid-state qubits. Their coherence properties are typically governed by the hyperfine coupling between these ``central'' electronic spins and the dense surrounding bath of lattice nuclear spins. Theoretically this is a challenging problem due to its many-body and strongly-correlated nature. Here we measure the spin dynamics of holes in InGaAs quantum dots by detecting their intrinsic, random spin fluctuations while in thermal equilibrium, which reveals the spin correlation time scales ?h and the functional form of bath-induced spin relaxation. In zero magnetic field, ?h is very long (˜400 ns) and decays exponentially, in marked contrast with recent theories. ?h increases to ˜5 ?s in small (100 G) longitudinal fields, and the spin dynamics evolve to a very slow ˜1/ln(t) decay [1]. We model the influence of nuclear quadrupolar coupling on spin dynamics in these strained QDs for both electrons and holes [2], and find a good agreement with experimental data when the quadrupolar coupling exceeds the hyperfine coupling strength. [1] Yan Li, N. Sinitsyn, et al., PRL 108, 186603 (2012). [2] N. Sinitsyn, Yan Li, et al., PRL 109, 166605 (2012).

Li, Yan; Sinitsyn, N. A.; Saxena, A.; Smith, D. L.; Reuter, D.; Wieck, A. D.; Yakovlev, D. R.; Manfred, B.; Crooker, S. A.

2013-03-01

169

Improper orientational ordering regime and tricritical behavior in a lyotropic liquid crystal.  

PubMed

Optical microscopy, deuteron quadrupolar NMR, x-ray diffraction, and electrical conductivity techniques have been used to map the phase diagram and to measure the nematic order parameter variation (S) in ternary mixtures of pentadecafluorooctanoate acid ammonium salt (APFO), heavy water (D2O), and ammonium chloride (NH4Cl). A phenomenological model with an isotropic parent phase and a single primary segregation order parameter is elaborated on to describe in consistent terms the linear dependence of S(T) through the whole nematic stability region as well as the existence of a tricritical point at the nematic-to-lamellar phase transition line. PMID:11969971

Dmitriev, V P; Ouriques, G R

1999-08-01

170

Magnetic order and superconductivity in electron doped Nd1.85Ce0.15CuO4  

NASA Astrophysics Data System (ADS)

Understanding the interplay between antiferromagnetism (AFM) and superconductivity (SC) in high-transition-temperature (high-Tc) superconductors is one of the most important outstanding problems in condensed matter physics. Theoretically, it was predicted that a magnetic field induces antiferromagnetic (AF) order in the vortex state of the high-Tc cuprates. Neutron scattering experiments on La2-xSrxCuO4 (LSCO) show enhanced AF order in the vortex state. Muon spin resonance (muSR) and Nuclear Magnetic Resonance (NMR) experiments in YBa2Cu3O6+x (YBCO) and Tl2Ba2CuO6+x compounds show similar enhanced AF order, predominantly originating from regions near the vortex core. However, none of these experiments have probed magnetic ordering of the state where SC is completely destroyed by the magnetic field. This question is especially important since transport measurements show peculiar behavior of such a state. Here we report results from neutron scattering experiments on the optimally electron-doped high-Tc superconductor Nd1.85Ce0.15CuO4 (NCCO), where the upper critical field (Bc2) can be reached. The applied field induces a novel commensurate and static AF order different from its parent compound. The induced AF moment increases approximately linearly with increasing field up to Bc2 and then saturates for B > Bc2, clearly establishing a direct connection between this novel magnetic structure and the SC.

Kang, Hye Jung; Dai, Pengcheng; Lynn, J. W.; Thompson, J. R.; Zhang, Shoucheng; Onose, Y.; Tokura, Y.

2003-03-01

171

Magnetic ordering in the frustrated J1-J2 Ising chain candidate BaNd2O4  

NASA Astrophysics Data System (ADS)

The AR2O4 family (R =rare earth) has recently been attracting interest as a new series of frustrated magnets, with the magnetic R atoms forming zigzag chains running along the c axis. We have investigated polycrystalline BaNd2O4 with a combination of magnetization, heat-capacity, and neutron powder diffraction measurements. Magnetic Bragg peaks are observed below TN=1.7K, and they can be indexed with a propagation vector of k?=(0,1/2,1/2). The signal from magnetic diffraction is well described by long-range ordering of only one of the two types of Nd zigzag chains, with collinear up-up-down-down intrachain spin configurations (double Néel state). Furthermore, low-temperature magnetization and heat-capacity measurements reveal two magnetic-field-induced spin transitions at 2.75 and 4 T for T =0.46K. The high-field phase is paramagnetic, while the intermediate-field state may arise from a spin transition of the long-range ordered Nd chains. One possible candidate for the field-induced ordered state corresponds to an up-up-down intrachain spin configuration, as predicted for a classical J1-J2 Ising chain with a double Néel ground state in zero field.

Aczel, A. A.; Li, L.; Garlea, V. O.; Yan, J.-Q.; Weickert, F.; Jaime, M.; Maiorov, B.; Movshovich, R.; Civale, L.; Keppens, V.; Mandrus, D.

2014-10-01

172

Dynamic Effects in MAS and MQMAS NMR Spectra of Half-Integer Quadrupolar Nuclei: Calculations and an  

E-print Network

and an Application to the Double Perovskite Cryolite Mrignayani Kotecha, Santanu Chaudhuri, Clare P. Grey, and Lucio in the double perovskite cryolite, Na3AlF6. Dynamic line shape simulations invoking a second-order broadening with predictions stemming from molecular dynamic simulations on this double perovskite. 1. Introduction Solid state

Frydman, Lucio

173

Order Up  

ERIC Educational Resources Information Center

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…

Gibeault, Michael

2005-01-01

174

Experimental and Theoretical Studies of Quadrupolar Oligothiophene-Cored Chromophores Containing Dimesitylboryl Moieties as ?-Accepting End-Groups: Syntheses, Structures, Fluorescence, and One- and Two-Photon Absorption.  

PubMed

Quadrupolar oligothiophene chromophores composed of four to five thiophene rings with two terminal (E)-dimesitylborylvinyl groups (4?V-5?V), and five thiophene rings with two terminal aryldimesitylboryl groups (5?B), as well as an analogue of 5?V with a central EDOT ring (5?VE), have been synthesized via Pd-catalyzed cross-coupling reactions in high yields (66-89?%). Crystal structures of 4?V, 5?B, bithiophene 2?V, and five thiophene-derived intermediates are reported. Chromophores 4?V, 5?V, 5?B and 5?VE have photoluminescence quantum yields of 0.26-0.29, which are higher than those of the shorter analogues 1?V-3?V (0.01-0.20), and short fluorescence lifetimes (0.50-1.05?ns). Two-photon absorption (TPA) spectra have been measured for 2?V-5?V, 5?B and 5?VE in the range 750-920?nm. The measured TPA cross-sections for the series 2?V-5?V increase steadily with length up to a maximum of 1930?GM. We compare the TPA properties of 2?V-5?V with the related compounds 5?B and 5?VE, giving insight into the structure-property relationship for this class of chromophore. DFT and TD-DFT results, including calculated TPA spectra, complement the experimental findings and contribute to their interpretation. A comparison to other related thiophene and dimesitylboryl compounds indicates that our design strategy is promising for the synthesis of efficient dyes for two-photon-excited fluorescence applications. PMID:25168267

Ji, Lei; Edkins, Robert M; Sewell, Laura J; Beeby, Andrew; Batsanov, Andrei S; Fucke, Katharina; Drafz, Martin; Howard, Judith A K; Moutounet, Odile; Ibersiene, Fatima; Boucekkine, Abdou; Furet, Eric; Liu, Zhiqiang; Halet, Jean-François; Katan, Claudine; Marder, Todd B

2014-10-13

175

Magnetic-field-induced dose effects in MR-guided radiotherapy systems: dependence on the magnetic field strength  

NASA Astrophysics Data System (ADS)

Several institutes are currently working on the development of a radiotherapy treatment system with online MR imaging (MRI) modality. The main difference between their designs is the magnetic field strength of the MRI system. While we have chosen a 1.5 Tesla (T) magnetic field strength, the Cross Cancer Institute in Edmonton will be using a 0.2 T MRI scanner and the company Viewray aims to use 0.3 T. The magnetic field strength will affect the severity of magnetic field dose effects, such as the electron return effect (ERE): considerable dose increase at tissue air boundaries due to returning electrons. This paper has investigated how the ERE dose increase depends on the magnetic field strength. Therefore, four situations where the ERE occurs have been simulated: ERE at the distal side of the beam, the lateral ERE, ERE in cylindrical air cavities and ERE in the lungs. The magnetic field comparison values were 0.2, 0.75, 1.5 and 3 T. Results show that, in general, magnetic field dose effects are reduced at lower magnetic field strengths. At the distal side, the ERE dose increase is largest for B = 0.75 T and depends on the irradiation field size for B = 0.2 T. The lateral ERE is strongest for B = 3 T but shows no effect for B = 0.2 T. Around cylindrical air cavities, dose inhomogeneities disappear if the radius of the cavity becomes small relative to the in-air radius of the secondary electron trajectories. At larger cavities (r > 1 cm), dose inhomogeneities exist for all magnetic field strengths. In water-lung-water phantoms, the ERE dose increase takes place at the water-lung transition and the dose decreases at the lung-water transition, but these effects are minimal for B = 0.2 T. These results will contribute to evaluating the trade-off between magnetic field dose effects and image quality of MR-guided radiotherapy systems.

Raaijmakers, A. J. E.; Raaymakers, B. W.; Lagendijk, J. J. W.

2008-02-01

176

Magnetic-field-induced dose effects in MR-guided radiotherapy systems: dependence on the magnetic field strength.  

PubMed

Several institutes are currently working on the development of a radiotherapy treatment system with online MR imaging (MRI) modality. The main difference between their designs is the magnetic field strength of the MRI system. While we have chosen a 1.5 Tesla (T) magnetic field strength, the Cross Cancer Institute in Edmonton will be using a 0.2 T MRI scanner and the company Viewray aims to use 0.3 T. The magnetic field strength will affect the severity of magnetic field dose effects, such as the electron return effect (ERE): considerable dose increase at tissue air boundaries due to returning electrons. This paper has investigated how the ERE dose increase depends on the magnetic field strength. Therefore, four situations where the ERE occurs have been simulated: ERE at the distal side of the beam, the lateral ERE, ERE in cylindrical air cavities and ERE in the lungs. The magnetic field comparison values were 0.2, 0.75, 1.5 and 3 T. Results show that, in general, magnetic field dose effects are reduced at lower magnetic field strengths. At the distal side, the ERE dose increase is largest for B = 0.75 T and depends on the irradiation field size for B = 0.2 T. The lateral ERE is strongest for B = 3 T but shows no effect for B = 0.2 T. Around cylindrical air cavities, dose inhomogeneities disappear if the radius of the cavity becomes small relative to the in-air radius of the secondary electron trajectories. At larger cavities (r > 1 cm), dose inhomogeneities exist for all magnetic field strengths. In water-lung-water phantoms, the ERE dose increase takes place at the water-lung transition and the dose decreases at the lung-water transition, but these effects are minimal for B = 0.2 T. These results will contribute to evaluating the trade-off between magnetic field dose effects and image quality of MR-guided radiotherapy systems. PMID:18263948

Raaijmakers, A J E; Raaymakers, B W; Lagendijk, J J W

2008-02-21

177

Magnetic-field-induced dose effects in MR-guided radiotherapy systems: dependence on the magnetic field strength  

Microsoft Academic Search

Several institutes are currently working on the development of a radiotherapy treatment system with online MR imaging (MRI) modality. The main difference between their designs is the magnetic field strength of the MRI system. While we have chosen a 1.5 Tesla (T) magnetic field strength, the Cross Cancer Institute in Edmonton will be using a 0.2 T MRI scanner and

A. J. E. Raaijmakers; B. W. Raaymakers; J. J. W. Lagendijk

2008-01-01

178

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...

179

Magnetic Field Induced Metal-Insulator in Mercury-Cadmium Alloy and Mercury Zinc Telluride Cadmium-Telluride Superlattice  

NASA Astrophysics Data System (ADS)

Resistivity measurements in high magnetic fields (0-12 T) and at low temperatures (1.2-30 K) on single crystal HgCdTe alloy and HgZnTe-CdTe superlattices indicate that, if the electron density is low, they exhibit a metal-insulator -transition, i.e., metallic at low magnetic field and insulating at high magnetic field. However, in heavily indium-doped alloy this is not observed. Heavily indium-doped alloys and a few unintentionally doped superlattices showed quantum oscillation (Shubnikov-de Haas oscillation) where the effective masses, Dingle temperature, and density are extracted. In low density alloys and superlattices, the analysis concluded that the transition to insulating by the bulk (three-dimensional-electron-gas) is shunted by the quasi -two-dimensional-electron gas at the buffer-layer interface or the top surface, i.e., parallel conduction. The presence of quasi-two-dimensional-electron-gas in an alloy has resulted in an anomalous behavior of the Hall coefficient with the magnetic field. The anomaly in the alloy is explained as due to the bulk three-dimensional-electron-gas exhibiting a Mott type metal-insulator-transition beyond the critical field and, eventually at high field, the quasi-two-dimensional -electron-gas becomes the dominant conducting channel. Therefore, the effective volume contributing to the charge transport is varying with the magnetic field. Similarly, in superlattices, parallel conduction is due to a few superlattice layers near the buffer-superlattice interface (or top surface) and the rest of the superlattice layers. However, in superlattices, both types of charge carriers have been found to exhibit Shubnikov-de Haas oscillations in different regimes of magnetic field. At high field only the quasi-two-dimensional -electron-gas contribute to the transport while the rest of the superlattice layers has exhibited a metal-insulator -transition at lower field.

Rafol, Sir B.

180

Vibronic coupling and a magnetic-field-induced avoided crossing in the S1<-- absorption spectrum of palladiumporphin  

Microsoft Academic Search

An avoided crossing of the 786 and 815 cm-1 vibronic bands in the absorption spectra of palladiumporphin (PdP) in n-alkane hosts in the presence of an external magnetic field is reported. A description of this effect is presented in terms of the Zeeman perturbation and intramolecular vibronic coupling. It appears to be closely connected with the orbital degeneracy of the

E. C. M. Kielman-van Luijt; G. W. Canters

1978-01-01

181

Vibronic coupling and a magnetic-field-induced avoided crossing in the S1?S0 absorption spectrum of palladiumporphin  

Microsoft Academic Search

An avoided crossing of the 786 and 815 cm vibronic bands in the absorption spectra of palladiumporphin (PdP) in n-alkane hosts in the presence of an external magnetic field is reported. A description of this effect is presented in terms of the Zeeman perturbation and intramolecular vibronic coupling. It appears to be closely connected with the orbital degeneracy of the

E. C. M. Kielman-van Luijt; G. W. Canters

1978-01-01

182

Quantitative photoacoustic depth profilometry of magnetic field-induced thermal diffusivity inhomogeneity in the liquid crystal octylcyanobiphenyl  

E-print Network

of thermal diffusivity decreases extending to 20-30 pm below the liquid crystal surface. These decaying depth inhomogeneity in the liquid crystal octylcyanobiphenyl Andreas Mandelisa) Photoacoustic and Photothermal in the nematic phase at 37 "C and 37.5 "C is reported. The application of a recent thermal-wave theory developed

Mandelis, Andreas

183

Study of molecular order and dynamics in calamitic and discotic liquid crystals by (2)H NMR  

NASA Astrophysics Data System (ADS)

Deuterium nuclear magnetic resonance (NMR) spectroscopy was used to explore molecular motions in the mesophases of calamatic liquid crystals 4- n- pentyloxybenzylidene-4'- heptylaniline(50.7), p- (methoxybenzylidine)-p-n- butylaniline(MBBA or 10.4), 4-n- hexyloxy-4'-cyanobiphenyl (60CB), a mixture of 60CB and 4-n-octyloxy-4'-cyanobiphenyl (80CB), and discotic liquid crystals hexakis(n-hexyloxy)triphenylene(HAT6). The Zeeman and quadrupolar spin-lattice relaxation times were measured as a function of temperature at 15.1 MHz and 46 MHz using a broadband multiple-pulse sequence. In addition, quadrupolar splittings were measured for 60CB, 60CB/80CB mixture and columnar phase of HAT6. The TZ model was used to interpret the deuteron relaxation of biaxial molecules in the uniaxial medium. For 50.7, the analysis of the relaxation data in the nematic and smectic A phases supports a model which includes director fluctuations and rotational diffusion of an asymmetric rigid rotor in a biaxial potential of mean torque. The molecular biaxiality of the molecule is found, based on the relaxation data, to give a small positive molecular biaxial order parameter S xx-Syy. In addition, the activation energy for the tumbling motion of the molecule is found to be larger than that for the spinning motion. For MBBA, the zero-frequency spectral densities J0(0) data is quantitatively interpreted using a model that includes director fluctuations and rotational diffusion of symmetric rotors in a nematic phase. The contribution to J0(0) from director fluctuations has mainly a second-order component, whereas the first-order contribution to J1(?) is suppressed in the megahertz region (Larmor frequencies are 15.1 and 46 MHz) due to the high-frequency cutoff, which is estimated to be around 3-10 MHz for MBBA. For 60CB and 60CB/80CB mixture, the data analyses were carried out for both samples in order to achieve a consistent physical picture. The additive potential method is employed to model the quadrupolar splittings of 60CB, from which the potential of mean torque is parametrized, and the order parameter tensor for an ``average'' conformer is determined. A decoupled model is used to describe correlated internal motions of the end chain, which are independent of the molecular reorientation. The latter motion is treated using the small-step rotational diffusion model of Tarroni and Zannoni, while the former motion is described using a master rate equation.

Shen, Xiaodong

1998-12-01

184

Enhancing the central-transition NMR signal of quadrupolar nuclei by spin population transfer using SW-FAM pulse trains with a tangent-shaped sweep profile.  

PubMed

Solid-state NMR of quadrupolar nuclei with half-integer spin, such as (25)Mg (I=5/2) or (43)Ca (I=7/2), suffers from low sensitivity, which may be improved using spin population transfer (SPT) from the satellite transitions. Effecting SPT with good efficiency is especially challenging under static conditions, and several techniques such as double-frequency sweeps (DFS), hyperbolic secant pulses (HS) and frequency-swept fast-amplitude modulated pulses (SW-FAM) have been suggested for achieving the necessary manipulations of the satellite transitions. We here investigate the SPT properties of an SW-FAM sequence with a tangent-shaped profile. The new SW(tan)-FAM pulse train is shown to possess superior SPT performance to the SW(1/?)-FAM sequence, which hitherto has been considered to be the best FAM method for signal enhancement of static spectra, by both numerical simulations on a (27)Al model system, and experimental results on aluminium acetyl acetonate, Al(acac)(3). In addition, the CT enhancement of individual crystallites from the polycrystalline sample with a defined angle between principal z-axis of the diagonal Q-tensor and the external field was considered by numerical simulations. In the vicinity of the magic angle ?(m)=54.7°, a region of zero enhancement exists. Use of the SW(tan)-FAM sequence allows extending the frequency sweep further into this region, with beneficial effects for the overall enhancement and the faithfulness of the line shape. In agreement with previously published studies, our numerical simulations on SPT for single crystals again evidence that the enhancement factors for a polycrystalline sample range from zero enhancement to the maximum gain of 2I, with the total enhancement factor of the full powder pattern being the summation of these strongly varying individual factors. This variation is the cause for line shape distortions in SPT-enhanced spectra. At the same time, these findings prove the capability of frequency sweeps (i.e., DFS and SW-FAM) to fully invert the satellite transitions under certain conditions. PMID:22578791

Bräuniger, Thomas

2012-01-01

185

Orientational ordering and dynamics in the columnar phase of a discotic liquid crystal studied by deuteron NMR spectroscopy  

NASA Astrophysics Data System (ADS)

We report on a deuteron NMR study of quadrupolar splittings and spin-lattice relaxation times T1Q and T1Z as a function of temperature and at two different Larmor frequencies in the columnar phase of hexakis(n-hexyloxy)triphenylene (HAT6). The additive potential method is used to model the quadrupolar splittings, from which the potential of mean torque is parameterized, and the order parameter tensor for an "average" conformer is determined. The small-step rotational diffusion model is used to find the rotational diffusion constants D? and D? for the spinning and tumbling motions of the molecular core. It is found that D? is slightly larger than D? in contrast with the findings in calamitic liquid crystals. The decoupled model of Dong for correlated internal rotations in the end chains is used for the first time in a discotic liquid crystal. Both jump constants for one- and three-bond motions are nearly independent of temperature, while the jump constant for two-bond motion is thermally activated. The rotational speeds D? and D? are some two orders of magnitude slower than a typical charge hopping frequency between the aromatic cores of adjacent molecules in the columns. Thus, to a migrating charge, the "lattice" appears static with disorder being due to the instantaneous displacement of the cores with respect to each other.

Shen, X.; Dong, Ronald Y.; Boden, N.; Bushby, R. J.; Martin, P. S.; Wood, A.

1998-03-01

186

Order Phasmatodea  

NSDL National Science Digital Library

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.

Moxey, Carl F.

2002-01-01

187

Continuous-time Monte Carlo and spatial ordering in driven lattice gases: Application to driven vortices in periodic superconducting networks  

E-print Network

Coulomb gas as a model for magnetic field induced vortices in 2D superconducting networks. Two different vortices in periodic superconducting networks Violeta Gotcheva,* Yanting Wang, Albert T. J. Wang, and S models.1 One advantage of a lattice gas model for numerical simulations of driven interacting many

Teitel, Stephen L.

188

Continuous-time Monte Carlo and spatial ordering in driven lattice gases: Application to driven vortices in periodic superconducting networks  

Microsoft Academic Search

We consider the two-dimensional (2D) classical lattice Coulomb gas as a model for magnetic field induced vortices in 2D superconducting networks. Two different dynamical rules are introduced to investigate driven diffusive steady states far from equilibrium as a function of temperature and driving force. The resulting steady states differ dramatically depending on which dynamical rule is used. We show that

Violeta Gotcheva; Yanting Wang; Albert T. J. Wang; S. Teitel

2005-01-01

189

Possible Antiferro-Octupolar Order in Antiferromagnetic TbB2C2 Examined by Gd Substitution  

NASA Astrophysics Data System (ADS)

We have examined the effects of Gd substitution on the anomalous antiferromagnetic (AFM) properties of TbB2C2 having field-induced antiferro-quadrupolar (AFQ) ordered phases. The Gd substitution induces drastic changes in the magnetic properties. The AFM structure characteristic to TbB2C2, the anomalous increase in magnetic susceptibility below TN, and the strong preference of AFM domains disappear with the substitution of low Gd content of less than 10%. We propose a promising assumption that an antiferro-octupolar (AFO) ordering occurs at TN simultaneously with AFM ordering in TbB2C2. The fragility of anomalous properties originates in the fragility of the antiferro-octupolar interaction against the substitution of Gd3+ ions with L=0.

Matsuoka, Eiichi; Sasaki, Yuta; Usui, Daichi; Nakagawa, Masaaki; Onodera, Hideya

2006-12-01

190

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

SciTech Connect

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.

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

2013-05-15

191

MACHINE LEARNING : The Necessity of Order (is order in order ?)  

E-print Network

- 1 - MACHINE LEARNING : The Necessity of Order (is order in order ?) A. Cornuéjols Laboratoire de to facilitate learning. Yet, when machine learners exhibited sequencing effects, showing that some data sampling is intended to present ideas and directions of research that are currently studied in the machine learning

Paris-Sud XI, Université de

192

Determination of the (17)O Quadrupolar Coupling Constant and of the (13)C Chemical Shielding Tensor Anisotropy of the CO Groups of Pentane-2,4-dione and beta-Diketonate Complexes in Solution. NMR Relaxation Study.  

PubMed

13C NMR relaxation times T(1) of the carbonyl groups of pentane-2,4-dione and beta-diketonate complexes Al(acac)(3) and Zr(acac)(4) (acac: pentanedionate anion) were measured for various magnetic field strengths, allowing a determination of the contribution of the chemical shift anisotropy mechanism to the total relaxation. NOE and T(1) measurements for the (13)C nucleus of the central methine carbon furnished the correlation time tau(c) for the reorientation of theses species. The chemical shift tensor anisotropy Deltasigma could be deduced and compared to the values obtained in the solid state. The quadrupolar coupling constant (QCC) of the (17)O nucleus could also be determined by measuring the line width of the (17)O NMR signal and using the tau(c) value. QCC values for the complexes are in the same range as for the pentane-2,4-dione molecule, indicating similar electronic distribution and symmetry around the oxygen atom of these different species. Deltasigma for the complexes are close together, and the values obtained in solution are approximately those obtained in the solid state. They are close to the value reported in the literature for tetraacetylethane, which can be considered as a dimer of a beta-diketone, but slight differences are observed for the individual components of the chemical shielding tensor. PMID:11666182

Champmartin, D.; Rubini, P.

1996-01-01

193

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

NASA Astrophysics Data System (ADS)

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.

Chen, Gang; Pereira, Rodrigo; Balents, Leon

2010-11-01

194

Variable Order and Distributed Order Fractional Operators  

NASA Technical Reports Server (NTRS)

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.

Lorenzo, Carl F.; Hartley, Tom T.

2002-01-01

195

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

E-print Network

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. ...

Peterson, Bradley William

2006-01-01

196

Magnetic field induced superconducting fluctuations in L{sub 2-x}Ce{sub x}CuO{sub 4-y} single crystals.  

SciTech Connect

Magnetization and electrical transport measurements under magnetic field H|c are reported for L{sub 2-x}Ce{sub x}CuO{sub 4} single crystals. Close to the upper critical field line a broad region is found were field induced fluctuations dominate the reversible electromagnetic response of the crystals. Excellent scalings of 2D nature are found for enhanced diamagnetism and excess conductivity, which in addition allow to extract a linear H{sub c2}(T) close to {Tc}.

Fabrega, L.; Crusellas, M. A.; Fontcuberta, J.; Obradors, X.; Pinol, S.; Welp, U.; Crabtree, G. W.; Materials Science Division; Inst. de Ciencia de Materials

1994-01-01

197

Large remnant polarization and magnetic field induced destruction of cycloidal spin structure in Bi1-xLaxFeO3 (0 ? x ? 0.2)  

NASA Astrophysics Data System (ADS)

We prepared a series of Bi1-xLaxFeO3 (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 Hc, which is attributed to the destruction of the cycloidal antiferromagnetic spin structure. The critical field Hc decreases substantially from ˜20 T for the x = 0 sample [Y. F. Popov et al., JETP Lett. 57, 69 (1993)] to ˜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 Hc increases with decreasing temperature. The variation of Hc 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 (2Pr) as high as ˜64 ?C/cm2 is obtained for the x = 0.15 sample. These results may be important for potential applications in BiFeO3-based magnetoelectric devices.

Yin, L. H.; Yang, J.; Zhao, B. C.; Liu, Y.; Tan, S. G.; Tang, X. W.; Dai, J. M.; Song, W. H.; Sun, Y. P.

2013-06-01

198

Mössbauer study on the magnetic field-induced insulator-to-metal transition in perovskite EU0.6Sr0.4MnO3  

NASA Astrophysics Data System (ADS)

We have investigated the spin dynamics of a distorted perovskite EU0.6Sr0.4MnO3 by means of Mössbauer spectroscopy. Below 70 K the exchange interaction grows gradually, and below 42 K the spins tum into a cluster glass state. The magnetic fieldinduced insulator-to-metal (IM) transition at low temperature is a transition from cluster glass to ferromagnet. The induced metallic phase seems to be still in non-uniform electronic state. On the other hand, at 80 K, just above T c of the induced ferromagnet, a metamagnetic transition was observed.

Nakamura, Shin; Sato, Masami; Morimoto, Shotaro; Nasu, Saburo; Tsunoda, Yorihiko

199

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

SciTech Connect

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.

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

200

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

NASA Astrophysics Data System (ADS)

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.

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

201

Understanding Invitational Travel Orders  

MedlinePLUS

... out how!. Apply Now Home » Deployment Understanding Invitational Travel Orders Invitational Travel Orders (ITOs) are issued when doctors determine that ... ITOs, you're eligible to receive money for travel, lodging, and daily food expenses. This daily expense ...

202

First-order inflation  

SciTech Connect

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.

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

1990-09-01

203

ASDC Order Tools  

... ASDC Web Ordering Tools Java Tool Help HTML Tool Help These tools allow users to search our data holdings ... The ordering tool is available in both Java and HTML versions. Reverb Search Tool Reverb Tutorial ...

2012-04-17

204

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.

205

Order of Operations  

NSDL National Science Digital Library

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 ...

Nieman, Mrs.

2008-10-05

206

Order and dynamics of a liquid crystalline dendrimer by means of 2H NMR spectroscopy.  

PubMed

A complete Deuterium NMR study performed on partially deuterated liquid crystalline carbosilane dendrimer is here reported. The dendrimer under investigation shows a SmA phase in a large temperature range from 381 to 293 K, and its mesophasic properties have been previously determined. However, in this work the occurrence of a biphasic region between the isotropic and SmA phases has been put in evidence. The orientational order of the dendrimer, labeled on its lateral mesogenic units, is here evaluated in the whole temperature range by means of (2)H NMR, revealing a peculiar trend at low temperatures (T < 326 K). This aspect has been further investigated by a detailed analysis of the (2)H NMR spectral features, such as the quadrupolar splitting, the line shape, and the line-width, as a function of temperature. In the context of a detailed NMR analysis, relaxation times (T(1) and T(2)) have also been measured, pointing out a slowing down of the dynamics by decreasing the temperature, which determines from one side the spectral changes observed in the NMR spectra, on the other the observation of a minimum in the T(1). PMID:18956837

Domenici, Valentina; Cifelli, Mario; Veracini, Carlo Alberto; Boiko, Natalia I; Agina, Elena V; Shibaev, Valery P

2008-11-27

207

Characterizing limit order prices  

NASA Astrophysics Data System (ADS)

A computational model of a limit order book is used to study the effect of different limit order distribution offsets. Reference prices such as same side/contra side best market prices and last traded price are considered in combination with different price offset distributions. We show that when characterizing limit order prices, varying the offset distribution only produces different behavior when the reference price is the contra side best price. Irrespective of the underlying mechanisms used in computing the limit order prices, the shape of the price graph and the behavior of the average order book profile distribution are strikingly similar in all the considered reference prices/offset distributions. This implies that existing averaging methods can cancel variabilities in limit order book shape/attributes and may be misleading.

Withanawasam, R. M.; Whigham, P. A.; Crack, Timothy Falcon

2013-11-01

208

Multiple ordering in magnetite.  

NASA Technical Reports Server (NTRS)

Results of a self-consistent band calculation of the ground-state energy and charge orderings based on a tight-binding scheme in magnetite are presented. They show that below a critical (about 2.2) value of the ratio of interatomic Coulomb energy to bandwidth the lowest energy state has no order. Between this critical value and 2.5, the preferred state is multiply ordered.

Cullen, J. R.; Callen, E. R.

1973-01-01

209

Exploring Order of Operations  

NSDL National Science Digital Library

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.

2012-08-06

210

Bioregions and World Order.  

ERIC Educational Resources Information Center

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:…

Breakthrough, 1985

1985-01-01

211

Three orders, three women  

Microsoft Academic Search

A truism of the Middle Ages of Western Europe was that society was naturally divided into three ordo, interdependent orders: those who pray, those who fight (and thus rule), and those who toil. Even as some people worried over changing gradations within the orders, few questioned that a three?part social structure was necessary for stability and in accordance with God's

Jane Eblen Keller

1999-01-01

212

Programming Languages: Marching Orders  

NSDL National Science Digital Library

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.

Bell, Tim; Witten, Ian; Fellows, Mike; Adams, Robyn; Mckenzie, Jane

2005-01-01

213

Order the Decimals  

NSDL National Science Digital Library

In this interactivity, students are required to order eight decimals from least to greatest by numbering them. Students can check answers and pieces of a picture are revealed behind their correct choices. Students can request a hint or to see all eight numbers in order and play again. Quia Web offers free shared activities with teacher-made content. Subscriptions allow members to create or alter the content of the games.

2011-01-01

214

Theory of ordered spaces  

NASA Astrophysics Data System (ADS)

This is the first of a planned series of investigations on the theory of ordered spaces based upon four axioms. Two of these, the order (I.1.1) and the local structure (II.5.1) axioms provide the structure of the theory, and the other two [the identification (I.1.11) and cone (I.2.7) axioms] eliminate pathologies or excessive generality. In the present paper the axioms are supplemented by the nontriviality conditions (I.1.9) and a regularity property (II.4.2). The starting point is a nonempty set M and a family of distinguished subsets, called light rays, which are totally ordered. The order axiom provides the properties of this order. Positive and negative cones at a point are defined in terms of increasing and decreasing subsets and are used to extend the total order on the light rays to a partial order over all of M. The first significant result is the polygon lemma (I.2.3) which provides an essential constructive tool. A non-topological definition is found for the interiors of the cones; it leads to a “more homogeneous” partial order relation on M. In Sect. II, subsets called D-sets (Def. II.2.2), possessing certain desirable properties, are studied. The key concept of perpendicularity of light rays is isolated (Def. II. 3.1) and used to derive the basic “separation properties,” provided that the interiors of cones are nonempty. It is shown that, in a D-set, “good” properties of one cone can be transported along light rays, so that the structure of a D-set is homogeneous. In particular, if one cone has nomempty interior, so have all others. However, the existence of even one cone with nomepty interior does not follow from the axioms, but has to be imposed as an additional regularity condition. The local structure axiom now states that every point lies in a regular D-set. It is proved that the family of regular D-sets is closed under finite intersections. The order topology is defined as the topology which has this family as a base. This topology is Hausdorff, and coincides with the usual topology for Minkowski spaces.

Borchers, H.-J.; Sen, R. N.

1990-09-01

215

Birth Order and Psychopathology  

PubMed Central

Context: Ordinal position the child holds within the sibling ranking of a family is related to intellectual functioning, personality, behavior, and development of psychopathology. Aim: To study the association between birth order and development of psychopathology in patients attending psychiatry services in a teaching hospital. Settings and Design: Hospital-based cross-sectional study. Materials and Methods: Retrospective file review of three groups of patients was carried out. Patient-related variables like age of onset, birth order, family type, and family history of mental illness were compared with psychiatry diagnosis (ICD-10) generated. Statistical Analysis: SPSS 13; descriptive statistics and one-way analysis of variance (ANOVA) were used. Results: Mean age of onset of mental illness among the adult general psychiatry patients (group I, n = 527) was found to be 33.01 ± 15.073, while it was 11.68 ± 4.764 among the child cases (group II, n = 47) and 26.74 ± 7.529 among substance abuse cases (group III, n = 110). Among group I patients, commonest diagnosis was depression followed by anxiety and somatoform disorders irrespective of birth order. Dissociative disorders were most prevalent in the first born child (36.7%) among group II patients. Among group III patients, alcohol dependence was maximum diagnosis in all birth orders. Conclusions: Depression and alcohol dependence was the commonest diagnosis in adult group irrespective of birth order. PMID:24479023

Risal, Ajay; Tharoor, Hema

2012-01-01

216

Templated quasicrystalline molecular ordering.  

PubMed

Quasicrystals are materials with long-range ordering but no periodicity. We report scanning tunneling microscopy (STM) observations of quasicrystalline molecular layers on 5-fold quasicrystal surfaces. The molecules adopt positions and orientations on the surface consistent with the quasicrystalline ordering of the substrate. Carbon-60 adsorbs atop sufficiently separated Fe atoms on icosahedral Al-Cu-Fe to form a unique quasicrystalline lattice, whereas further C60 molecules decorate remaining surface Fe atoms in a quasi-degenerate fashion. Pentacene (Pn) adsorbs at 10-fold symmetric points around surface-bisected rhombic triacontahedral clusters in icosahedral Ag-In-Yb. These systems constitute the first demonstrations of quasicrystalline molecular ordering on a template. PMID:24528205

Smerdon, J A; Young, K M; Lowe, M; Hars, S S; Yadav, T P; Hesp, D; Dhanak, V R; Tsai, A P; Sharma, H R; McGrath, R

2014-03-12

217

Sympathy and Social Order  

ERIC Educational Resources Information Center

Social order is possible only if individuals forgo the narrow pursuit of self-interest for the greater good. For over a century, social scientists have argued that sympathy mitigates self-interest and recent empirical work supports this claim. Much less is known about why actors experience sympathy in the first place, particularly in fleeting…

Irwin, Kyle; McGrimmon, Tucker; Simpson, Brent

2008-01-01

218

Order, topology and preference  

NASA Technical Reports Server (NTRS)

Some standard order-related and topological notions, facts, and methods are brought to bear on central topics in the theory of preference and the theory of optimization. Consequences of connectivity are considered, especially from the viewpoint of normally preordered spaces. Examples are given showing how the theory of preference, or utility theory, can be applied to social analysis.

Sertel, M. R.

1971-01-01

219

An ordering experiment  

Microsoft Academic Search

Binary comparison operators form the basis of consumer set theory. If humans could only perform binary comparisons, the most efficient procedure a human might employ to make a complete preference ordering of n items would be a nlog2n algorithm. But, if humans are capable of assigning each item an ordinal utility value, they are capable of implementing a more efficient

A. Norman; M. Ahmed; J. Chou; K. Fortson; C. Kurz; H. Lee; L. Linden; K. Meythaler; R. Rando; K. Sheppard; N Tantzen; I White; M Ziegler

2003-01-01

220

Order: Tylenchida Family: Heteroderidae  

E-print Network

in the soil in search of a suitable host plant (Figs. 2a, 2b). Root-knot nematode second-stage juvenilesOrder: Tylenchida Family: Heteroderidae Species: Meloidogyne incognita (southern root-knot nematode), M. arenaria (peanut root-knot nematode), M. javanica (Javanese root-knot nematode), M. hapla

Liskiewicz, Maciej

221

Comparing and Ordering Fractions  

NSDL National Science Digital Library

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.

2007-12-12

222

Land and World Order.  

ERIC Educational Resources Information Center

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…

Mische, Patricia, Ed.; And Others

1982-01-01

223

Operation Order Algebra Game  

NSDL National Science Digital Library

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.

2012-01-01

224

Blueberries Cost/ # Ordered Total  

E-print Network

.00 x _______ $ ________.00 TOTAL BLUEBERRIES AMOUNT: $ ________.00 Strawberries # Ordered Total x STRAWBERRIES AMOUNT: $ ________.00 Strawberries (see below) · Earliglow........................ · Honeoye plants & up = $16.00 per 100 Strawberry Information 75 plants = $18.00 There will be no individual sale

Liskiewicz, Maciej

225

Optimal Ordered Problem Solver  

Microsoft Academic Search

We introduce a general and in a certain sense time-optimal way of solving one problem after another, efficiently searching the space of programs that compute solution candidates, including those programs that organize and manage and adapt and reuse earlier acquired knowledge. The Optimal Ordered Problem Solver (OOPS) draws inspiration from Levin's Universal Search designed for single problems and universal Turing

Juergen Schmidhuber

2002-01-01

226

Majority voting on orders  

Microsoft Academic Search

We characterize two lexicographic-type preference extension rules from a set X to the set ? of all orders on this set. Elements of X are interpreted as basic economic policy decisions, whereas elements of ? are conceived as political programs among which a collectivity has to choose through majority voting. The main axiom is called tournament-consistency, and states that whenever

Gilbert Laffond; Jean Lainé

2000-01-01

227

Education and World Order  

ERIC Educational Resources Information Center

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…

Jones, Phillip W.

2007-01-01

228

From order to justice  

Microsoft Academic Search

We can observe in the progression of the work of Thomas Hobbes through David Hume to John Rawls a development from a focus on severe disorder to order under law and then to concern with distribution. This striking development is not due simply to changes of normative views, but is in large part about the technical or virtually technological capacities

Russell Hardin

2005-01-01

229

Microfluidics of ordered fluids  

NASA Astrophysics Data System (ADS)

Flow of ordered fluids (e.g. liquid crystals) is inherently complex due to the coupling between the flow and the long-range orientational order. Experiments carried out with nematic liquid crystals at micro scales further reveal the influence of surface properties on the static and dynamic outcomes. Microfluidics provide a convenient platform to tune one or more of the above competing components, and explore the resulting equilibrium states. The delicate but intricate balance between the viscous, elastic and surface forces was consequently used to devise optofluidic and micro-scale-transport applications. On one hand the novel applications complement the conventional microfluidic capabilities, and on the other hand, broaden the reach of isotropic microfluidics by offering competitive advantages. Standard microfluidic techniques and a combination of polarizing optical microscopy, fluorescence confocal polarizing microscopy and particle tracking methods were employed for the investigations.

Sengupta, Anupam

2013-03-01

230

Icosahedral order in liquids  

SciTech Connect

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.

Egami, Takeshi [ORNL

2007-01-01

231

Second order symmetry operators  

E-print Network

Using systematic calculations in spinor language, we obtain simple descriptions of the second order symmetry operators for the conformal wave equation, the Dirac-Weyl equation and the Maxwell equation on a curved four dimensional Lorentzian manifold. The conditions for existence of symmetry operators for the different equations are seen to be related. Computer algebra tools have been developed and used to systematically reduce the equations to a form which allows geometrical interpretation.

Lars Andersson; Thomas Bäckdahl; Pieter Blue

2014-02-25

232

Nematic Order on Foams  

NASA Astrophysics Data System (ADS)

We investigate the competition between nematic order and area minimization in nematic foams, in particular, how the structure is affected by the bending of the nematic director, and whether these systems will continue to obey Plateau's laws. We study the minimum energy configurations of the director field on a one parameter family of perturbed Reuleaux tetrahedra with special attention to the location of topological defects. We determine the energy distribution at the Plateau borders versus the film surface and relate the change in structure to changes in elastic constants and surface tension.

Chen, Bryan; Kamien, Randall

2008-03-01

233

Transverse nuclear spin relaxation due to director fluctuations in liquid crystals. II. Second-order contributions of the fluctuating director  

NASA Astrophysics Data System (ADS)

Recently, we have introduced a slow-motional theory for transverse nuclear spin relaxation due to director fluctuations [D. Frezzato, G. Kothe, and G. J. Moro, J. Phys. Chem. B 105, 1281 (2001)]. This method is now generalized to second-order contributions of the fluctuating director. We consider the specific case in which the director is aligned orthogonal to the magnetic field. By exploiting the Gaussian character of director fluctuations, the stochastic Liouville equation for the coupled spin and director dynamics is solved in terms of a characteristic function whose time dependence is determined by a nonlinear integral equation. A convenient solution of the integral equation is obtained by decomposing the characteristic function according to the relaxation rates of the director fluctuations. In a first application, we evaluate the free induction decay and the corresponding absorption spectrum for quadrupolar probe nuclei in nematic liquid crystals. It is shown that the transverse magnetization is well represented by a monoexponential decay, i.e., a Lorentzian lineshape in the frequency domain. Explicit relations are derived for the linewidths and frequency shifts under slow-motional conditions where the Redfield theory cannot be applied anymore.

Frezzato, Diego; Moro, Giorgio J.; Kothe, Gerd

2003-10-01

234

Computerized Physician Order Entry  

PubMed Central

Computerized physician order entry (CPOE) has been promoted as an important component of patient safety, quality improvement, and modernization of medical practice. In practice, however, CPOE affects health care delivery in complex ways, with benefits as well as risks. Every implementation of CPOE is associated with both generally recognized and unique local factors that can facilitate or confound its rollout, and neurohospitalists will often be at the forefront of such rollouts. In this article, we review the literature on CPOE, beginning with definitions and proceeding to comparisons to the standard of care. We then proceed to discuss clinical decision support systems, negative aspects of CPOE, and cultural context of CPOE implementation. Before concluding, we follow the experiences of a Chief Medical Information Officer and neurohospitalist who rolled out a CPOE system at his own health care organization and managed the resulting workflow changes and setbacks. PMID:24381708

Khanna, Raman; Yen, Tony

2014-01-01

235

Preparation and use of preconstructed orders, order sets, and order menus in a computerized provider order entry system  

Microsoft Academic Search

ObjectiveTo describe the configuration and use of the computerized provider order entry (CPOE) system used for inpatient and outpatient care at the authors' facility.DesignDescription of order configuration entities, use patterns, and configuration changes in a production CPOE system.MeasurementsThe authors extracted and analyzed the content of order configuration entities (order dialogs, preconfigured [quick] orders, order sets, and order menus) and determined

Thomas H Payne; Patty J Hoey; Paul Nichol; Christian Lovis

2003-01-01

236

Order without design  

PubMed Central

Experimental reality in molecular and cell biology, as revealed by advanced research technologies and methods, is manifestly inconsistent with the design perspective on the cell, thus creating an apparent paradox: where do order and reproducibility in living systems come from if not from design? I suggest that the very idea of biological design (whether evolutionary or intelligent) is a misconception rooted in the time-honored and thus understandably precious error of interpreting living systems/organizations in terms of classical mechanics and equilibrium thermodynamics. This error, introduced by the founders and perpetuated due to institutionalization of science, is responsible for the majority of inconsistencies, contradictions, and absurdities plaguing modern sciences, including one of the most startling paradoxes - although almost everyone agrees that any living organization is an open nonequilibrium system of continuous energy/matter flow, almost everyone interprets and models living systems/organizations in terms of classical mechanics, equilibrium thermodynamics, and engineering, i.e., in terms and concepts that are fundamentally incompatible with the physics of life. The reinterpretation of biomolecules, cells, organisms, ecosystems, and societies in terms of open nonequilibrium organizations of energy/matter flow suggests that, in the domain of life, order and reproducibility do not come from design. Instead, they are natural and inevitable outcomes of self-organizing activities of evolutionary successful, and thus persistent, organizations co-evolving on multiple spatiotemporal scales as biomolecules, cells, organisms, ecosystems, and societies. The process of self-organization on all scales is driven by economic competition, obeys empirical laws of nonequilibrium thermodynamics, and is facilitated and, thus, accelerated by memories of living experience persisting in the form of evolutionary successful living organizations and their constituents. PMID:20398287

2010-01-01

237

59Co NMR evidence for charge and orbital order in the kagome-like structure of Na2/3CoO2  

NASA Astrophysics Data System (ADS)

We report a complete set of 59Co NMR data taken on the x=2/3 phase of sodium cobaltates NaxCoO2 for which we have formerly established the in-plane Na ordering and its three-dimensional stacking from a combination of symmetry arguments taken from Na and Co NQR/NMR data. Here, we resolve all the parameters of the Zeeman and quadrupolar Hamiltonians for all cobalt sites in the unit cell and report the temperature dependencies of the NMR shift and spin lattice relaxation T1 data for these sites. We confirm that three nonmagnetic Co3+ (Co1) are in axially symmetric positions and that the doped holes are delocalized on the nine complementary magnetic cobalt sites (Co2) of the atomic unit cell. The moderately complicated atomic structure resumes then in a very simple electronic structure in which the electrons delocalize on the Co2 kagome sublattice of the triangular lattice of Co sites. The observation of a single temperature dependence of the spin susceptibilities indicates that a single band picture applies, and that the magnetic properties are dominated by the static and dynamic electronic properties at the Co2 sites. We evidence that they display a strong in-plane electronic anisotropy initially unexpected but which agrees perfectly with an orbital ordering along the kagome sublattice organization. These detailed data should now permit realistic calculations of the electronic properties of this compound in order to determine the incidence of electronic correlations.

Mukhamedshin, I. R.; Alloul, H.

2011-10-01

238

Higher Order Differential Attack Using Chosen Higher Order Differences  

Microsoft Academic Search

This paper introduces an improved higher order differential attack using chosen higher order differences. We can find a lower\\u000a order of the higher order differential by choosing higher order differences. It follows that the designers of a block cipher\\u000a can evaluate the lower bound of the number of chosen plaintexts and the complexity required for the higher order differential\\u000a attack.

Shiho Moriai; Takeshi Shimoyama; Toshinobu Kaneko

1998-01-01

239

Symmetry, shape, and order  

E-print Network

Packing problems have been of great interest in many diverse contexts for many centuries. The optimal packing of identical objects has been often invoked to understand the nature of low temperature phases of matter. In celebrated work, Kepler conjectured that the densest packing of spheres is realized by stacking variants of the face-centered cubic lattice and has a packing fraction of $\\pi/(3\\sqrt{2}) \\sim 0.7405$. Much more recently, an unusually high density packing of approximately 0.770732 was achieved for congruent ellipsoids. Such studies are relevant for understanding the structure of crystals, glasses, the storage and jamming of granular materials, ceramics, and the assembly of viral capsid structures. Here we carry out analytical studies of the stacking of close-packed planar layers of systems made up of truncated cones possessing uniaxial symmetry. We present examples of high density packing whose order is characterized by a {\\em broken symmetry} arising from the shape of the constituent objects. We find a biaxial arrangement of solid cones with a packing fraction of $\\pi/4$. For truncated cones, there are two distinct regimes, characterized by different packing arrangements, depending on the ratio $c$ of the base radii of the truncated cones with a transition at $c^*=\\sqrt{2}-1$.

Antonio Trovato; Trinh X. Hoang; Jayanth R. Banavar; Amos Maritan

2007-12-17

240

Order in spontaneous behavior.  

PubMed

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

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

2007-01-01

241

Preparation and Use of Preconstructed Orders, Order Sets, and Order Menus in a Computerized Provider Order Entry System  

PubMed Central

Objective: To describe the configuration and use of the computerized provider order entry (CPOE) system used for inpatient and outpatient care at the authors' facility. Design: Description of order configuration entities, use patterns, and configuration changes in a production CPOE system. Measurements: The authors extracted and analyzed the content of order configuration entities (order dialogs, preconfigured [quick] orders, order sets, and order menus) and determined the number of orders entered in their production order entry system over the previous three years. The authors measured use of these order configuration entities over a six-month period. They repeated the extract two years later to measure changes in these entities. Results: CPOE system configuration, conducted before and after first production use, consisted of preparing 667 order dialogs, 5,982 preconfigured (quick) orders, and 513 order sets organized in 703 order menus for particular contexts, such as admission for a particular diagnosis. Fifty percent of the order dialogs, 57% of the quick orders, and 13% of the order sets were used within a six-month period. Over the subsequent two years, the volume of order configuration entities increased by 26%. Conclusions: These order configuration steps were time-consuming, but the authors believe they were important to increase the ordering speed and acceptability of the order entry software. Lessons learned in the process of configuring the CPOE ordering system are given. Better understanding of ordering patterns may make order configuration more efficient because many of the order configuration entities that were created were not used by clinicians. PMID:12668686

Payne, Thomas H.; Hoey, Patty J.; Nichol, Paul; Lovis, Christian

2003-01-01

242

Orientational ordering and dynamics of the hydrate and exchangeable hydrogen atoms in crystalline crambin.  

PubMed

Deuterium nuclear magnetic resonance studies of crambin crystals grown from deuterated solvent (2H2O/CH3CH2O2H or H2O/C2H3CH2OH) are reported. The extent to which the hydrate and exchangeable hydrogen atoms are dynamically disordered are then determined from the size of the residual deuterium quadrupole couplings, qcc. Rapid molecular reorientation (tau c-1 greater than 10(5) s-1) reduces the magnitude of the quadrupole coupling from its static value (216 kHz for solid water). We find that the room temperature spectrum of crambin is dominated by two features: a sharp line with very small residual quadrupolar coupling less than 3 kHz, and a broad pattern with a quadrupolar coupling in the range 185 to 195 kHz. The former is indicative of very nearly isotropically reorienting deuterons, whereas the latter is somewhat narrower than that observed for the amide deuterons of poly-gamma-benzyl-L-glutamate and thus indicative of deuterons that are almost but not completely stationary. By considering the nuclear magnetic resonance spectrum intensities along with the amino acid sequence, X-ray structure and the manner in which quadrupole couplings are reduced by dynamics, we conclude that the nuclear magnetic resonance signal from most of the water molecules of hydration are contained in the sharp line, i.e. reorient nearly isotropically in the crystalline protein. Unlike bulk water, which freezes abruptly in the manner of a phase transition, the water of hydration in crambin has a broad freezing range from 180 to 250K, as evidenced by the decreasing intensity of the sharp line that disappears at 180K. At temperatures between 150 and 200K, a typical hydrate molecule reorients at a rate comparable to the quadrupole coupling, 10(4) s-1 to 10(5) s-1, a process that occurs in hexagonal ice in the range of 240 to 270K. At 140K, the hydrate is stationary, tau c-1 less than 10(3) s-1. Studies of the protein crystallized from solvent deuterated only at the non-exchangeable methyl group of ethanol confirm that ethanol is in the lattice and show that this solvate behaves in much the same way as the hydrate. The refined X-ray structure has identified four ethanol solvate molecules. The deuterium spectrum at room temperature has a well-defined residual pattern with qcc = 2.2 kHz, i.e. a small-order parameter consistent with nearly isotropically reorienting molecules. The spectrum width broadens substantially only at temperatures below 200K and achieves the characteristic spectrum of a rotating methyl group with stationary C-C axis at 140K.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2810359

Usha, M G; Wittebort, R J

1989-08-20

243

Time Ordering in Kicked Qubits  

E-print Network

We examine time ordering effects in strongly, suddenly perturbed two-state quantum systems (kicked qubits) by comparing results with time ordering to results without time ordering. Simple analytic expressions are given for state occupation amplitudes and probabilities for singly and multiply kicked qubits. We investigate the limit of no time ordering, which can differ in different representations.

L. Kaplan; Kh. Kh. Shakov; A. Chalastaras; M. Maggio; A. L. Burin; J. H. McGuire

2004-06-23

244

Extensional Higher-Order Datalog?  

Microsoft Academic Search

We deflne a higher-order extension of Datalog based on the Horn fragment of higher-order logic introduced in (Wad91). Programs of Higher-Order Datalog can be understood declaratively as formulas in extensional higher-order logic, in which (for example) a unary predicate of unary predicates is a set of sets of data objects. The language retains all the basic principles of flrst-order logic

Vassilis Kountouriotis; Panos Rondogiannis; William W. Wadge

245

A Total ACCompatible Reduction Ordering on HigherOrder Terms  

E-print Network

A Total AC­Compatible Reduction Ordering on Higher­Order Terms Daria Walukiewicz ? Institute of Informatics, Warsaw University Banacha 2, 02­097 Warsaw, Poland email: daria@mimuw.edu.pl Abstract. The higher

Walukiewicz-Chrz¹szcz, Daria

246

Protective orders: questions and conundrums.  

PubMed

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

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

2006-07-01

247

Order-order Nucleation in Copolymers: A String Method Approach  

NASA Astrophysics Data System (ADS)

The mechanism of nucleation in order-order phase transitions of block copolymers is an interesting problem presenting both theoretical and numerical challenges. In this talk we will introduce our recent work of applying the string method to the order-order nucleation in diblock copolymer. We use the self-consistent field model, and search for the saddle point of the free energy functional by solving a variational problem. We will also talk about a study of the epitaxial relation between ordered phases (work by Wang Chu et al.), which verifies one of the assumptions taken by the numerical method beforehand.

Cheng, Xiuyuan; E, Weinan; Zhang, Pingwen; Shi, Anchang; Wang, Chu

2012-02-01

248

Deuterium spin probes of backbone order in proteins: 2H NMR relaxation study of deuterated carbon alpha sites.  

PubMed

(2)H spin relaxation NMR experiments to study the dynamics of deuterated backbone alpha-positions, D(alpha), are developed. To date, solution-state (2)H relaxation measurements in proteins have been confined to side-chain deuterons-primarily (13)CH(2)D or (13)CHD(2) methyl groups. It is shown that quantification of (2)H relaxation rates at D(alpha) backbone positions and the derivation of associated order parameters of C(alpha)-D(alpha) bond vector motions in small [U-(15)N,(13)C,(2)H]-labeled proteins is feasible with reasonable accuracy. The utility of the developed methodology is demonstrated on a pair of proteins-ubiquitin (8.5 kDa) at 10, 27, and 40 degrees C, and a variant of GB1 (6.5 kDa) at 22 degrees C. In both proteins, the D(alpha)-derived parameters of the global rotational diffusion tensor are in good agreement with those obtained from (15)N relaxation rates. Semiquantitative solution-state NMR measurements yield an average value of the quadrupolar coupling constant, QCC, for D(alpha) sites in proteins equal to 174 kHz. Using a uniform value of QCC for all D(alpha) sites, we show that C(alpha)-D(alpha) bond vectors are motionally distinct from the backbone amide N-H bond vectors, with (2)H-derived squared order parameters of C(alpha)-D(alpha) bond vector motions, S(2)(CalphaDalpha), on average slightly higher than their N-H amides counterparts, S(2)(NH). For ubiquitin, the (2)H-derived backbone mobility compares well with that found in a 1-mus molecular dynamics simulation. PMID:19821582

Sheppard, Devon; Li, Da-Wei; Brüschweiler, Rafael; Tugarinov, Vitali

2009-11-01

249

Tame ordered structures Antongiulio Fornasiero  

E-print Network

Tame ordered structures Antongiulio Fornasiero antongiulio.fornasiero@googlemail.com University of Münster Logic Colloquium 2009 A. Fornasiero (University of Münster) Tame ordered structures LC 2009 1 / 25 #12;Introduction Introduction A definably complete (DC) structure is a linearly ordered structure K

Fornasiero, Antongiulio

250

A point of order 8  

E-print Network

A formula expressing a point of order 8 on an elliptic curve, in terms of the roots of the associated cubic polynomial, is given. Doubling such a point yields a point of order 4 distinct from the well-known points of order 4 given in standard references such as "A course of Modern Analysis" by Whittaker and Watson.

Semjon Adlaj

2011-10-03

251

Ordered Delinquency: The "Effects" of Birth Order On Delinquency  

PubMed Central

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

Cundiff, Patrick R.

2014-01-01

252

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

PubMed

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

Cundiff, Patrick R

2013-08-01

253

Simulation of order scheduling under hybrid order fulfillment strategy  

Microsoft Academic Search

In recent aggressive competition age, automobile manufacturing industries are trying to implement innovative strategies compare to traditional build-to-forecast to cut large order fulfillment time (lead times). The research work here concentrates on the discrete-event-simulation of order-scheduling process in automobile industry and try to explore the possibilities of innovative strategies for optimization of order scheduling and hence lead-times. It gives detailed

Uwe Clausen; Zhou Ling; Sandeep B. Khot; Bernhard Heimann

2007-01-01

254

Timing of Orders, Order Aggressiveness and the Order Book at the Paris Bourse  

Microsoft Academic Search

We offer a statistical model of the order flow and estimate it using high frequency data from the Paris Bourse. Our model jointly explains the duration between two consecutive orders and the relative aggressiveness of the orders, depending upon the past ordes and the state of the book. Our results offer evidence of information and liquidity effects, as put forward

Christophe BISIÈRE; Thierry KAMIONKA

2000-01-01

255

Counterbalancing for Serial Order Carryover Effects in Experimental Condition Orders  

ERIC Educational Resources Information Center

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…

Brooks, Joseph L.

2012-01-01

256

Surface melting of electronic order.  

SciTech Connect

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.

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

257

Prerequisites for chiral charge order  

NASA Astrophysics Data System (ADS)

The chiral charge density wave state which was recently discovered in TiSe2 can be understood as a combination of orbital and charge order. Here, we discuss the prerequisite material properties for this type of chiral charge order to emerge. We find that although both the lattice and orbital structure constrain the set of candidate materials, there remains a class of materials in which chiral charge order is expected to emerge.

van Wezel, Jasper

2012-06-01

258

Scrolling partially ordered event displays  

Microsoft Academic Search

Understanding the partial-order relationship between events is critical to understand the behaviour of a distributed or parallel application. Many problems need to be solved in order to provide an accurate and useful display of a large partial order, such as will occur during the execution of any non-trivial application. A display will most likely resemble a process-time diagram, but the

David Taylor

2005-01-01

259

Birth Order: Reconciling Conflicting Effects  

Microsoft Academic Search

Secular trends in test scores are accurately predicted by trends in aggregate birth orders. The trend data contradict individual-difference analyses that show birth order as a poor predictor of individual test scores. This article demonstrates why the 2 formulations of the problem the individually, distributed birth order analysis and aggregate-pattern analysis-generate different results. A meaningful interpretation is given by the

Robert B. Zajonc; Patricia R. Mullally

1997-01-01

260

Order-by-order Analytic Solution to the BFKL Equation  

E-print Network

We propose a regularization of the BFKL equation which allows for its solution in each order of perturbation theory by means of a sum over multiple poles. This sum can be presented in a rather simple formula for the Fourier transform in the azimuthal angle of the gluon Green function. In order to test our method, we have compared a few orders in the expansion to previous results by Del Duca, Dixon, Duhr and Pennington, finding agreement. Our formalism is general and can be applied to other, more complicated, kernels.

Ross, D A

2014-01-01

261

Introduction to Order of Operations  

NSDL National Science Digital Library

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.

2010-01-01

262

First order ball bearing kinematics  

NASA Technical Reports Server (NTRS)

Two first order equations are given connecting geometry and internal motions in an angular contact ball bearing. Total speed, kinematic equivalence, basic speed ratio, and modal speed ratio are defined and discussed; charts are given for the speed ratios covering all bearings and all rotational modes. Instances where specific first order assumptions might fail are discussed, and the resulting effects on bearing performance reviewed.

Kingbury, E.

1984-01-01

263

Automated ordering of fingerprinted clones  

Microsoft Academic Search

Motivation: A considerable amount of human intervention is currently required to produce high-quality fingerprint-based physical maps for genomic studies. Results: An algorithm has been developed and imple- mented to automatically order fingerprinted clones within con- tigs. The resulting software, named CORAL (Clone ORdering ALgorithm), has been tested on maps that have previously been manually edited and on maps derived from

Stephane Flibotte; Readman Chiu; Chris Fjell; Martin Krzywinski; Jacqueline E. Schein; Heesun Shin; Marco A. Marra

2004-01-01

264

Children's Order 10 Years on  

ERIC Educational Resources Information Center

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…

Kerr, Linda

2006-01-01

265

Birth Order: Reconciling Conflicting Effects.  

ERIC Educational Resources Information Center

Introduces the confluence model as a theory specifying the process by which the intellectual environment modifies intellectual development. Using this model, explores the contradiction between prediction of secular trends in test scores by trends in aggregate birth order and the lack of prediction of individual test scores by birth order using…

Zajonc, Robert B.; Mullally, Patricia R.

1997-01-01

266

Problem Order Implications for Learning  

ERIC Educational Resources Information Center

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…

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

2013-01-01

267

Post-Newtonian accurate parametric solution to the dynamics of spinning compact binaries in eccentric orbits: The leading order spin-orbit interaction  

E-print Network

We derive Keplerian-type parametrization for the solution of post-Newtonian (PN) accurate conservative dynamics of spinning compact binaries moving in eccentric orbits. The PN accurate dynamics that we consider consists of the third post-Newtonian accurate conservative orbital dynamics influenced by the leading order spin effects, namely the leading order spin-orbit interactions. The orbital elements of the representation are explicitly given in terms of the conserved orbital energy, angular momentum and a quantity that characterizes the leading order spin-orbit interactions in Arnowitt, Deser, and Misner-type coordinates. Our parametric solution is applicable in the following two distinct cases: (i) the binary consists of equal mass compact objects, having two arbitrary spins, and (ii) the binary consists of compact objects of arbitrary mass, where only one of them is spinning with an arbitrary spin. As an application of our parametrization, we present gravitational wave polarizations, whose amplitudes are restricted to the leading quadrupolar order, suitable to describe gravitational radiation from spinning compact binaries moving in eccentric orbits. The present parametrization will be required to construct `ready to use' reference templates for gravitational waves from spinning compact binaries in inspiralling eccentric orbits. Our parametric solution for the post-Newtonian accurate conservative dynamics of spinning compact binaries clearly indicates, for the cases considered, the absence of chaos in these systems. Finally, we note that our parametrization provides the first step in deriving a fully second post-Newtonian accurate `timing formula', that may be useful for the radio observations of relativistic binary pulsars like J0737-3039.

Christian Koenigsdoerffer; Achamveedu Gopakumar

2005-01-05

268

Scalar Order: Possible Candidate for Order Parameters in Skutterudites  

NASA Astrophysics Data System (ADS)

Phenomenological Landau analysis shows that the properties of ordered phases in some skutterudites are consistently accounted for by a scalar-order parameter which preserves the cubic symmetry, even in the ordered phase. A universal value is found for the anisotropy ratio of the transition temperature in a magnetic field, homogeneous magnetization, and induced staggered magnetization. The difference in magnetic behavior between PrFe4P12 and PrRu4P12 near their phase transitions is explained within a single framework. For the low-field phase of PrFe4P12, the scalar order with ?1g symmetry can explain (i) the absence of field-induced dipoles perpendicular to the magnetic field, (ii) isotropic magnetic susceptibility in the ordered phase, (iii) the field-angle dependence of the transition temperature, and (iv) the splitting pattern of the 31P nuclear magnetic resonance (NMR) spectra. It is proposed how the order parameter in SmRu4P12 is identified by NMR analysis of a single crystal.

Kiss, Annamária; Kuramoto, Yoshio

2006-10-01

269

7 CFR 1214.12 - Order.  

Code of Federal Regulations, 2012 CFR

...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....

2012-01-01

270

7 CFR 1221.18 - Order.  

Code of Federal Regulations, 2010 CFR

...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....

2010-01-01

271

Complex higher order derivative theories  

SciTech Connect

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.

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

272

Multiple order common path spectrometer  

NASA Technical Reports Server (NTRS)

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.

Newbury, Amy B. (Inventor)

2010-01-01

273

Chimera order in spin systems  

E-print Network

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.

Rajeev Singh; Subinay Dasgupta; Sitabhra Sinha

2010-11-23

274

Institutional Order, Interaction Order and Social Order: Administering Welfare, Disciplining the Poor1  

E-print Network

address as a president of the American Sociological Association, Erving Goffman returns to the relation: Interaction order; Social structures; Institutions; People-processing encounters; Welfare; Erving Goffman. 1, Erving Goffman returns to what he calls "the interaction order," and to its relation with social

Paris-Sud XI, Université de

275

Executive Order 1083 Attachment C  

E-print Network

Rev 2/2013 Executive Order 1083 Attachment C California Child Abuse and Neglect Reporting Act Penal, but not limited to, foster parents, group home personnel, and personnel of residential care facilities. (15

de Lijser, Peter

276

Order, Chaos and All That!  

ERIC Educational Resources Information Center

The evolution of ideas about the concept of chaos is surveyed. Discussed are chaos in deterministic, dynamic systems; order in dissipative systems; and thermodynamics and irreversibility. Included are logistic and bifurcation maps to illustrate points made in the discussion. (CW)

Glasser, L.

1989-01-01

277

Cation Ordering in Layered Nickelates  

NASA Astrophysics Data System (ADS)

The single layer Ruddlesden-Popper nickelates present a model system to understand how the effects of digital dopant cation ordering may affect the properties of 2-dimensional conducting sheets. We investigate the effects of aliovalent A-site cation order on LaSrNiO4 films. Using molecular beam epitaxy, we interleave full layers of SrO and LaO in a series of chemically equivalent films, varying the pattern of SrO and LaO layers relative to the NiO2 layers. Through synchrotron surface x-ray diffraction and Coherant Bragg Rod Analysis (COBRA), we directly investigate the A-site cation order and the resulting atomic displacements for each ordering pattern. We correlate these results with theoretical calculations and transport measurements of the layered nickelate films.

Nelson-Cheeseman, Brittany; Zhou, Hua; Cammarata, Antonio; Hoffman, Jason; Balachandran, Prasanna; Rondinelli, James; Bhattacharya, Anand

2013-03-01

278

Helicoidal ordering in iron perovskites.  

PubMed

We study the double exchange in transition metal oxides with itinerant and localized electrons. We show that the charge transfer energy Delta and the oxygen-oxygen hopping amplitude t(pp) have a strong effect on magnetic ordering: while for Delta>0 the ground state is ferromagnetic, for negative Delta and large t(pp) the double exchange gives rise to an incommensurate helicoidal ordering of local spins, observed, e.g., in the iron perovskites SrFeO3 and CaFeO3. For negative Delta, the metal-insulator transition into a charge-ordered state has little effect on magnetic ordering. This explains the difference in magnetic and transport properties of ferrates and manganites. PMID:15904026

Mostovoy, Maxim

2005-04-01

279

Online Ordering of Official Transcripts  

E-print Network

Operating Procedures Cost of Transcript Accounting #12;UMACRAO 2006 Overview System Modules Web Server Merchant Storefront Customer enters credit card info Transaction authorized or denied Order IT Project System modules Business Practices & Operating Procedures Cost of Transcript & Accounting Auth

Wisconsin at Madison, University of

280

Life from an orderly cosmos  

NASA Astrophysics Data System (ADS)

Recent astrophysical studies suggest a high degree of order in the inanimate universe, stemming from cosmic beginnings. This state is consistent with the nonrandomness observed experimentally in the thermal polymers of amino acids that figure as an early inanimate stage in organic evolution. The various stages in inanimate matter, protocells, and evolved cells and the degree of order that they represent comport with the second law of thermodynamics on a cosmic scale.

Fox, Sidney W.

1980-12-01

281

Birth Order, Schooling, and Earnings  

Microsoft Academic Search

Birth-order effects are posited by many to affect earnings and schooling. The authors show how such effects can be interpreted to shift either the earnings possibility frontier for siblings or parental preferences. The authors find empirical evidence for birth- order effects on (age-adjusted) schooling and on earnings for young U.S. adults, though the latter is not robust for all specifications.

Jere R. Behrman; Paul Taubman

1986-01-01

282

WORD ORDER, WORD ORDER FLEXIBILITY AND THE LEXICON  

E-print Network

, if any word of syntactic category C uniquely determines a phrasal mother node M, in accordance that a theoretical treatment of these issues must come in a single package, preferably not specific to word order in the form of a lexicalized grammar, or something akin to the c-structure of LFG) as a consequence

Bozsahin, Cem

283

Using High-Order Methods on Lower-Order Geometries  

NASA Technical Reports Server (NTRS)

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.

Casper, Jay

1997-01-01

284

Order in a multidimensional system  

PubMed Central

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

Roy Frieden, B.; Gatenby, Robert A.

2014-01-01

285

Order in a multidimensional system  

NASA Astrophysics Data System (ADS)

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.

Frieden, B. Roy; Gatenby, Robert A.

2011-07-01

286

Tree reconstruction from partial orders  

SciTech Connect

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.

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

1993-03-01

287

Tree reconstruction from partial orders  

SciTech Connect

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.

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

1993-01-01

288

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

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.

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

289

Magnetic-field-induced transition in a wide parabolic well superimposed with a superlattice G. M. Gusev,1 Yu. A. Pusep,2 A. K. Bakarov,3 A. I. Toropov,3 and J. C. Portal4,5,6  

E-print Network

More recently novel three-dimensional 3D fractional quantum Hall FQH states in multilayer systems have been theoretically predicted.6 A 3D multilayer fractional quantum Hall state with average filling =1 and developing fractional quantum Hall FQH states and by the enhanced slope of the Hall resistance. We attribute

Gusev, Guennady

290

NCI Mouse Repository - Ordering Information  

Cancer.gov

Mouse models are provided free of charge through the NCI Mouse Repository, however, the customer is responsible for shipping charges if the shipment must go by air or special truck. There is no charge for normal truck delivery. Up to three (3) breeder pairs are routinely supplied on an order. On occasion, larger numbers of breeder pairs may be available - please inquire.

291

Suffix Ordering and Morphological Processing  

ERIC Educational Resources Information Center

There is a long-standing debate about the principles constraining the combinatorial properties of suffixes. Hay 2002 and Hay & Plag 2004 proposed a model in which suffixes can be ordered along a hierarchy of processing complexity. We show that this model generalizes to a larger set of suffixes, and we provide independent evidence supporting the…

Plag, Ingo; Baayen, Harald

2009-01-01

292

Efficient Flexible Macroblock Ordering Technique  

NASA Astrophysics Data System (ADS)

The H.264/AVC standard provides several new error-resilient features to enable the reliable transmission of compressed video signals over lossy packet networks. Flexible Macroblock Ordering (FMO) is one of the most interesting resilient features within the H.264/AVC standard. Unlike former standards, in which slices were constructed out of consecutive raster scan macroblocks, FMO suggests new slices composed of spatially distributed Macroblocks (MBs), and organized in a mixed-up fashion. H.264/AVC specifies seven types of FMO. The standard defines also an explicit FMO type (Type 6), which allows explicitly assignment of each MB within the frame to any available slice groups. Therefore new FMO types can be used and integrated into H264/AVC without violating the standard. In this paper we propose a new Explicit Chessboard-Wipe (ECW) Flexible Macroblocks Ordering (FMO) technique, which outperforms all other FMO types. The new ECW ordering results in effective error scattering which maximizes the number of correctly received macroblocks located around corrupted macroblocks, leading to better error concealment. Performance evaluations demonstrate that the proposed Explicit FMO approach outperforms all the FMO types. Both subjective and objective visual quality comparative study has been also carried out in order to validate the proposed approach.

Psannis, Kostas; Ishibashi, Yutaka

293

Second-order algebraic theories  

E-print Network

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 7 SECOND-ORDER FUNCTORIAL SEMANTICS 93 7.1 Clone Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 7.2 Classifying Clones... and Bendix, 1970]; (iv) algebraic theories come with an associated notion of algebraic translation [Lawvere, 2004], whose syntactic counterpart provides the right notion of syntactic translation between equational presenta- tions [Fujiwara, 1959, Fujiwara...

Mahmoud, Ola

2011-11-08

294

Rihana Mungin Work Order Center  

E-print Network

Rihana Mungin Work Order Center Coordinator Jennifur Johnson Office Specialist 1 Anita Vermilya & Steam Fitter Steve Hiscoe HVAC Tech Brett Nance Plumber Lead Students (6) Carey Gibbar Trades Maint) Kevin Johnson Fire/Life Safety Electrician Students (2) Ashley Froelich- MacMillian Admin. Program

Latiolais, M. Paul

295

Rihana Mungin Work Order Center  

E-print Network

Rihana Mungin Work Order Center Coordinator Jennifur Johnson Office Specialist 1 Anita Vermilya & Steam Fitter Steve Hiscoe HVAC Tech Brett Nance Plumber Lead Students (6) Carey Gibbar Trades Maint Maint 2 Vacant Grounds Maint 1 Students (1) Norris, Beggs & Simpson Contract Students (5) Kevin Johnson

Bertini, Robert L.

296

Broadcasting in Partially Ordered Sets  

Microsoft Academic Search

Let be a partial order on a countable set V such that there exists a minimum element a2 V andfu2 V : u vg is nite for each v2 V. An item of information is to be broadcast to the elements ofV according to the policy in the following sense: a is initially informed and broadcasting to v 6= a

Kyle Siegrist

297

Graded infinite order jet manifolds  

E-print Network

The relevant material on differential calculus on graded infinite order jet manifolds and its cohomology is summarized. This mathematics provides the adequate formulation of Lagrangian theories of even and odd variables on smooth manifolds in terms of the Grassmann-graded variational bicomplex.

G. Sardanashvily

2007-08-17

298

Order computations in generic groups  

E-print Network

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 ...

Sutherland, Andrew V

2007-01-01

299

Weighted order statistic classifiers with large rank-order margin.  

SciTech Connect

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.

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

2003-01-01

300

Comparability Invariance Results for Tolerance Orders  

Microsoft Academic Search

We prove comparability invariance results for three classes of ordered sets: bounded tolerance orders (equivalent to parallel- ogram orders), unit bitolerance orders (equivalent to point-core bitolerance orders) and unit tolerance orders (equivalent to 50% tolerance orders). Each proof uses a different technique and relies on the alternate characterization.

Kenneth P. Bogart; Joshua D. Laison; Garth Isaak; Ann N. Trenk

2001-01-01

301

7 CFR 1220.608 - Order.  

Code of Federal Regulations, 2012 CFR

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

2012-01-01

302

7 CFR 1220.608 - Order.  

Code of Federal Regulations, 2010 CFR

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

2010-01-01

303

7 CFR 1220.608 - Order.  

Code of Federal Regulations, 2013 CFR

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

2013-01-01

304

7 CFR 1220.608 - Order.  

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

2014-01-01

305

7 CFR 1220.608 - Order.  

Code of Federal Regulations, 2011 CFR

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

2011-01-01

306

Ordered Magnesium-Lithium alloys  

Microsoft Academic Search

Emerging technologies increasingly depend on the production of ultra-lightweight materials. Magnesium-lithium (MgLi) alloys are the lightest metallic alloys, having densities near that of plastics, and are strong enough to be used in a variety of high- performance applications. Although considerable work has been done on the MgLi system, little is known regarding potential ordered phases. An analysis of the system

Richard Taylor; Stefano Curtarolo; Gus Hart

2009-01-01

307

Hidden order in the cuprates  

Microsoft Academic Search

We propose that the enigmatic pseudogap phase of cuprate superconductors is characterized by a hidden broken symmetry of d_x^2-y^2-type. The transition to this state is rounded by disorder, but in the limit that the disorder is made sufficiently small, the pseudogap crossover should reveal itself to be such a transition. The ordered state breaks time-reversal, translational, and rotational symmetries, but

Chetan Nayak; R. B. Laughlin; Dirk Morr

2001-01-01

308

Phylogenetic List of Insect Orders  

NSDL National Science Digital Library

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.

0002-11-30

309

The social order of markets  

Microsoft Academic Search

In this article I develop a proposal for the theoretical vantage point of the sociology of markets, focusing on the problem\\u000a of the social order of markets. The initial premise is that markets are highly demanding arenas of social interaction, which\\u000a can only operate if three inevitable coordination problems are resolved. I define these coordination problems as the value problem,

Jens Beckert

2009-01-01

310

Order stars and stability theorems  

Microsoft Academic Search

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.

G. Wanner; E. Hairer; S. P. Nørsett

1978-01-01

311

Higher Order City Voronoi Diagrams  

E-print Network

We investigate higher-order Voronoi diagrams in the city metric. This metric is induced by quickest paths in the L1 metric in the presence of an accelerating transportation network of axis-parallel line segments. For the structural complexity of kth-order city Voronoi diagrams of n point sites, we show an upper bound of O(k(n - k) + kc) and a lower bound of {\\Omega}(n + kc), where c is the complexity of the transportation network. This is quite different from the bound O(k(n - k)) in the Euclidean metric. For the special case where k = n - 1 the complexity in the Euclidean metric is O(n), while that in the city metric is {\\Theta}(nc). Furthermore, we develop an O(k^2(n + c) log n)-time iterative algorithm to compute the kth-order city Voronoi diagram and an O(nc log^2(n + c) log n)-time divide-and-conquer algorithm to compute the farthest-site city Voronoi diagram.

Gemsa, Andreas; Liu, Chih-Hung; Wagner, Dorothea

2012-01-01

312

RHO—Radiation Hybrid Ordering  

PubMed Central

Radiation hybrid (RH) mapping is a somatic cell technique that is used for ordering markers along a chromosome and estimating the physical distances between them. With the advent of this mapping technique, analyzing the experimental data is becoming a challenging and demanding computational task. In this paper we present the software package RHO (radiation hybrid ordering). The package implements a number of heuristics that attempt to order genomic markers along a chromosome, given as input the results of an RH experiment. The heuristics are based on reducing an appropriate optimization problem to the traveling salesman problem (TSP). The reduced optimization problem is either the nonparametric obligate chromosome breaks (OCBs) or the parametric maximum likelihood estimation (MLE). We tested our package on both simulated and publicly available RH data. For synthetic RH data, the reconstructed markers' permutation is very close to the original permutation, even with fairly high error rates. For real data we used the framework markers' data from the Whitehead Institute maps. For most of the chromosomes (18 out of 23), there is a perfect agreement or nearly perfect agreement (reversal of chromosome arm or arms) between our maps and the Whitehead framework maps. For the remaining five chromosomes, our maps improve on the Whitehead framework maps with respect to both optimization criteria, having higher likelihood and fewer breakpoints. For three chromosomes, the results differ significantly (lod score >1.75), with chromosome 2 having the largest improvement (lod score 3.776). PMID:10720577

Ben-Dor, Amir; Chor, Benny; Pelleg, Dan

2000-01-01

313

The Water Forcefield: Importance of Dipolar and Quadrupolar Interactions  

Microsoft Academic Search

It is widely recognized that dipolar interactions play a fundamental role in water. Less emphasis is put on the effects dues to the quadrupole moment. The recent calculation of the phase diagram for several rigid, nonpolarizable water models has shown that this is a rather severe test for water potentials. In this work, we analyze the results yielded by popular

J. L. F. Abascal; Carlos Vega

2007-01-01

314

8.EE Orders of Magnitude  

NSDL National Science Digital Library

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...

315

Crystalline order on the paraboloid  

NASA Astrophysics Data System (ADS)

We describe an experimental and theoretical investigation of crystalline order on a two-dimensional paraboloid. In contrast to the sphere, the paraboloid exhibits both variable Gaussian curvature and a boundary. Both these features must be treated for a thorough theoretical understanding. A macroscopic model of a parabolic crystal can be obtained in the laboratory by assembling a single layer of soap bubbles on the surface of a rotating liquid, thus extending the classic work of Bragg and Nye on planar arrays of soap bubbles.

Giomi, Luca; Bowick, Mark

2006-03-01

316

All Order Covariant Tubular Expansion  

NASA Astrophysics Data System (ADS)

We consider tubular neighborhood of an arbitrary submanifold embedded in a (pseudo-) Riemannian manifold. This can be described by Fermi normal coordinates (FNC) satisfying certain conditions as described by Florides and Synge in [15]. By generalizing the work of Muller et al. in [54] on Riemann normal coordinate expansion, we derive all order FNC expansion of vielbein in this neighborhood with closed form expressions for the curvature expansion coefficients. Our result is shown to be consistent with certain integral theorem for the metric proved in [15].

Mukhopadhyay, Partha

2014-11-01

317

Second order transport from anomalies  

NASA Astrophysics Data System (ADS)

We study parity odd transport at second order in derivative expansion for a non-conformal charged fluid. We see that there are 27 parity odd transport coefficients, of which 12 are non-vanishing in equilibrium. We use the equilibrium partition function method to express 7 of these in terms of the anomaly, shear viscosity, charge diffusivity and thermodynamic functions. The remaining 5 are constrained by 3 relations which also involve the anomaly. We derive Kubo formulae for 2 of the transport coefficients and show these agree with that derived from the equilibrium partition function.

Bhattacharyya, Sayantani; David, Justin R.; Thakur, Somyadip

2014-01-01

318

Superconductivity and Excitonic Charge Order  

NASA Astrophysics Data System (ADS)

It was suggested four decades ago that excitons as well as phonons could mediate superconductivity and that the temperature limits usually imposed by phonons could thus be avoided. In practice this form of excitonic pairing turned out to be elusive, because phonon softening typically causes a structural instability to occur before excitonic superconductivity has a chance to arise. Upon suppression of this CDW order however, superconductivity once again has an opportunity to materialise, as has recently been observed in for example pure TiSe2 under pressure. It is unclear what role is played by the excitons in such an environment of critical structural fluctuations, and whether they can have any effect on the pairing or indeed TC. Here we introduce a theoretical model to study the ways in which SC, CDW and excitonic order compete, coexist and even cooperate. Applying the model to TiSe2, we show that the hitherto elusive mechanism driving its CDW transition is a combination of excitonic and Jahn-Teller effects, and that under pressure it is likely to display an unusual type of superconductivity mediated by combinations of excitons and phonons.

van Wezel, Jasper; Nahai-Williamson, Paul; Saxena, Siddarth

2010-03-01

319

Neutralino annihilation beyond leading order  

NASA Astrophysics Data System (ADS)

High-precision measurements of the relic dark matter density and the calculation of dark matter annihilation branching fractions in the sun or the galactic halo today motivate the computation of the neutralino annihilation cross section beyond leading order. We consider neutralino annihilation via squark exchange and parameterize the effective annihilation vertex as a dimension-six operator suppressed by two powers of the squark mass and related to the divergence of the axial vector current of the final-state quarks. Since the axial vector current is conserved at tree level in the limit of massless quarks, this dimension-six operator contains a suppression by the quark mass. The quark mass suppression can be lifted in two ways: (1) by corrections to the dimension-six operator involving the anomalous triangle diagram, and (2) by going to dimension-eight. We address the first of these possibilities by evaluating the anomalous triangle diagram, which contributes to neutralino annihilation to gluon pairs. We relate the triangle diagram via the anomaly equation to the decay of a pseudoscalar into two gluons and use the Adler-Bardeen theorem to extract the next-to-leading order (NLO) QCD corrections to ???gg from the known corrections to pseudoscalar decay. The strong dependence of the dominant ???qqbar cross section on the relative velocity of the neutralinos makes these NLO corrections unimportant at ? decoupling but significant today.

Barger, Vernon; Keung, Wai-Yee; Logan, Heather E.; Shaughnessy, Gabe; Tregre, Adam

2006-02-01

320

Ordering Phenomena in Undercooled Alloys  

SciTech Connect

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].

Fultz, Brent

1997-07-17

321

Recent advances in ordered intermetallics  

SciTech Connect

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.

Liu, C.T.

1992-12-31

322

Quantum quenches and competing orders  

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

323

Quantum quenches and competing orders  

E-print Network

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, ( $\\boldsymbol{k}$, - $\\boldsymbol{k}$ ), in the Brillouin zone. We also study the nonequilibrium dynamics of a quantum generalization of a O(6) nonlinear $\\sigma$ model of competing orders in the underdoped cuprates [Hayward et al., Science $\\boldsymbol{343}$, 1336 (2014)]. 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.

Wenbo Fu; Ling-Yan Hung; Subir Sachdev

2014-02-04

324

Logistic equation of arbitrary order  

NASA Astrophysics Data System (ADS)

The paper is concerned with the new logistic equation of arbitrary order which describes the performance of complex executive systems X vs. number of tasks N, operating at limited resources K, at non-extensive, heterogeneous self-organization processes characterized by parameter f. In contrast to the classical logistic equation which exclusively relates to the special case of sub-extensive homogeneous self-organization processes at f=1, the proposed model concerns both homogeneous and heterogeneous processes in sub-extensive and super-extensive areas. The parameter of arbitrary order f, where -?

Grabowski, Franciszek

2010-08-01

325

29 CFR 2530.206 - Time and order of issuance of domestic relations orders.  

Code of Federal Regulations, 2010 CFR

...Time and order of issuance of domestic relations orders. 2530.206 Section 2530...Time and order of issuance of domestic relations orders. (a) Scope. This section...timing issues with respect to domestic relations orders and qualified domestic...

2010-07-01

326

Fourth order spatial derivative gravity  

NASA Astrophysics Data System (ADS)

In this work, we study a modified theory of gravity that contains up to fourth order spatial derivatives as a model for the Ho?ava-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.

Bemfica, F. S.; Gomes, M.

2011-10-01

327

Multilevel hierarchically ordered artificial biomineral.  

PubMed

Living organisms are known for creating complex organic-inorganic hybrid materials such as bone, teeth, and shells, which possess outstanding functions as compared to their simple mineral forms. This has inspired many attempts to mimic such structures, but has yielded few practical advances. In this study, a multilevel hierarchically ordered artificial biomineral (a composite of hydroxyapatite and gelatine) with favorable nanomechanical properties is reported. A typical optimized HAp/gelatin hybrid material in the perpendicular direction of the HAp c-axis has a modulus of 25.91 + 1.78 GPa and hardness of 0.90 + 0.10 GPa, which well matches that of human cortical bone (modulus 24.3 + 1.4 GPa, hardness 0.69 + 0.05 GPa). The bottom-up crystal constructions (from nano- to micro- to macroscale) of this material are achieved through a hard template approach by the phase transformation from DCP to HAp. The structural biomimetic material shows another way to mimic the complex hierarchical designs of sclerous tissues which have potential value for application in hard tissue engineering. PMID:23847156

Liu, Xiaoguo; Lin, Kaili; Wu, Chengtie; Wang, Yueyue; Zou, Zhaoyong; Chang, Jiang

2014-01-15

328

Advanced ordered intermetallic alloy deployment  

SciTech Connect

The need for high-strength, high-temperature, and light-weight materials for structural applications has generated a great deal of interest in ordered intermetallic alloys, particularly in {gamma}-based titanium aluminides {gamma}-based TiAl alloys offer an attractive mix of low density ({approximately}4g/cm{sup 3}), good creep resistance, and high-temperature strength and oxidation resistance. For rotating or high-speed components. TiAl also has a high damping coefficient which minimizes vibrations and noise. These alloys generally contain two phases. {alpha}{sub 2} (DO{sub 19} structure) and {gamma} (L 1{sub 0}), at temperatures below 1120{degrees}C, the euticoid temperature. The mechanical properties of TiAl-based alloys are sensitive to both alloy compositions and microstructure. Depending on heat-treatment and thermomechanical processing, microstructures with near equiaxed {gamma}, a duplex structure (a mix of the {gamma} and {alpha}{sub 2} phases) can be developed in TiAl alloys containing 45 to 50 at. % Al. The major concern for structural use of TiAl alloys is their low ductility and poor fracture resistance at ambient temperatures. The purpose of this project is to improve the fracture toughness of TiAl-based alloys by controlling alloy composition, microstructure and thermomechanical treatment. This work is expected to lead to the development of TiAl alloys with significantly improved fracture toughness and tensile ductility for structural use.

Liu, C.T.; Maziasz, P.J.; Easton, D.S. [Oak Ridge National Lab., TN (United States)

1997-04-01

329

Dislocation sources in ordered intermetallics  

SciTech Connect

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.

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

330

39 CFR 952.28 - Orders.  

Code of Federal Regulations, 2012 CFR

...Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PRACTICE IN PROCEEDINGS RELATIVE TO FALSE REPRESENTATION AND LOTTERY ORDERS § 952.28 Orders. (a) If an order is issued which prohibits delivery of mail to Respondent it...

2012-07-01

331

39 CFR 952.28 - Orders.  

Code of Federal Regulations, 2010 CFR

...Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PRACTICE IN PROCEEDINGS RELATIVE TO FALSE REPRESENTATION AND LOTTERY ORDERS § 952.28 Orders. (a) If an order is issued which prohibits delivery of mail to a respondent it...

2010-07-01

332

39 CFR 952.28 - Orders.  

Code of Federal Regulations, 2013 CFR

...Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PRACTICE IN PROCEEDINGS RELATIVE TO FALSE REPRESENTATION AND LOTTERY ORDERS § 952.28 Orders. (a) If an order is issued which prohibits delivery of mail to Respondent it...

2013-07-01

333

39 CFR 952.28 - Orders.  

Code of Federal Regulations, 2011 CFR

...Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PRACTICE IN PROCEEDINGS RELATIVE TO FALSE REPRESENTATION AND LOTTERY ORDERS (EFF. UNTIL 7-22-2011) § 952.28 Orders. (a) If an order is issued which prohibits delivery...

2011-07-01

334

40 CFR 89.503 - Test orders.  

Code of Federal Regulations, 2010 CFR

...NONROAD COMPRESSION-IGNITION ENGINES Selective Enforcement Auditing § 89.503 Test orders. (a) A test order addressed...may not issue to a manufacturer more Selective Enforcement Auditing (SEA) test orders than an annual limit determined to be...

2010-07-01

335

7 CFR 1212.15 - Order.  

Code of Federal Regulations, 2010 CFR

...COMMODITIES), DEPARTMENT OF AGRICULTURE HONEY PACKERS AND IMPORTERS RESEARCH, PROMOTION...EDUCATION AND INDUSTRY INFORMATION ORDER Honey Packers and Importers Research, Promotion...1212.15 Order. “Order” means the Honey Packers and Importers Research,...

2010-01-01

336

OFFPRINT ORDER FORM Return this form to  

E-print Network

# ________________________________________________ E-mail ________________________________________________ COMBUSTION AND FLAME Do Not Delay Ordering with us. Tax Exemption No._________________ Add $50 per 100 offprints ordered if color illustrations

Wooldridge, Margaret S.

337

Study of molecular order and dynamics in calamitic and discotic liquid crystals by (2)H NMR  

Microsoft Academic Search

Deuterium nuclear magnetic resonance (NMR) spectroscopy was used to explore molecular motions in the mesophases of calamatic liquid crystals 4- n- pentyloxybenzylidene-4'- heptylaniline(50.7), p- (methoxybenzylidine)-p-n- butylaniline(MBBA or 10.4), 4-n- hexyloxy-4'-cyanobiphenyl (60CB), a mixture of 60CB and 4-n-octyloxy-4'-cyanobiphenyl (80CB), and discotic liquid crystals hexakis(n-hexyloxy)triphenylene(HAT6). The Zeeman and quadrupolar spin-lattice relaxation times were measured as a function of temperature at 15.1 MHz

Xiaodong Shen

1998-01-01

338

ON HOMOGENEOUS ORDERED GRAPHS GREGORY CHERLIN  

E-print Network

ON HOMOGENEOUS ORDERED GRAPHS GREGORY CHERLIN Introduction We give a catalog of the known homogeneous ordered graphs. We believe this catalog is likely to be complete as it stands. We may classify.C: Linearly ordered homogeneous equivalence relations, with convex equivalence classes, each densely ordered

Cherlin, Gregory

339

Ordering molecular energies by moving boxes  

NASA Astrophysics Data System (ADS)

Structures such as isoprotonic-isoelectronic molecules can be mathematically represented by Young diagrams (or integer partitions), whose columns correspond to the different nuclear charges in a molecule. We found that these Young diagrams, when ordered by majorization, produce a partially ordered set, which is equivalent to the ordering of ground-state energies of the represented molecules. This result shows that the ordering of such energies can be derived by moving boxes in Young diagrams. The correspondence between majorization order and energy ordering opens the door for obtaining new general expressions for molecular properties.

Restrepo, Guillermo; Bernal, Andrés

2014-09-01

340

39 CFR 952.30 - Supplemental orders.  

Code of Federal Regulations, 2013 CFR

...Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PRACTICE IN PROCEEDINGS RELATIVE TO FALSE REPRESENTATION AND LOTTERY ORDERS § 952.30 Supplemental orders. When the Chief Postal Inspector or his or her designee, or the Chief Postal...

2013-07-01

341

39 CFR 952.30 - Supplemental orders.  

Code of Federal Regulations, 2011 CFR

...Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PRACTICE IN PROCEEDINGS RELATIVE TO FALSE REPRESENTATION AND LOTTERY ORDERS (EFF. UNTIL 7-22-2011) § 952.30 Supplemental orders. When the Chief Postal Inspector or...

2011-07-01

342

39 CFR 952.30 - Supplemental orders.  

Code of Federal Regulations, 2010 CFR

...Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PRACTICE IN PROCEEDINGS RELATIVE TO FALSE REPRESENTATION AND LOTTERY ORDERS § 952.30 Supplemental orders. When the Chief Postal Inspector or his or her designee or his...

2010-07-01

343

39 CFR 952.30 - Supplemental orders.  

Code of Federal Regulations, 2012 CFR

...Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PRACTICE IN PROCEEDINGS RELATIVE TO FALSE REPRESENTATION AND LOTTERY ORDERS § 952.30 Supplemental orders. When the Chief Postal Inspector or his or her designee, or the Chief Postal...

2012-07-01

344

40 CFR 305.24 - Default order.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Default order. 305.24 Section 305.24 Protection of Environment ENVIRONMENTAL PROTECTION...CLAIMS AGAINST THE SUPERFUND Prehearing Procedures § 305.24 Default order. (a) Default. A...

2010-07-01

345

48 CFR 1316.505 - Ordering.  

Code of Federal Regulations, 2012 CFR

...DEPARTMENT OF COMMERCE CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Indefinite-Delivery Contracts 1316.505 Ordering. The department's Task and Delivery Order Ombudsman is designated in CAM...

2012-10-01

346

48 CFR 1316.505 - Ordering.  

Code of Federal Regulations, 2011 CFR

...DEPARTMENT OF COMMERCE CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Indefinite-Delivery Contracts 1316.505 Ordering. The department's Task and Delivery Order Ombudsman is designated in CAM...

2011-10-01

347

40 CFR 91.604 - Test orders.  

Code of Federal Regulations, 2010 CFR

...CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Selective Enforcement Auditing Regulations § 91.604 Test orders. (a) A test order addressed to the manufacturer is required for any testing...

2010-07-01

348

Interrelationships of Fishes of the Order Stomiiformes  

E-print Network

The order Stomiiformes (Vertebrata: Actinopterygii) is composed of 417 of deep open ocean fishes, including some of the most abundant vertebrates on earth. The monophyly of the order is well established morphologically, ...

DeVaney, Shannon C.

2008-01-01

349

Inferring Temporal Ordering of Events in News  

Microsoft Academic Search

This paper describes a domain-independent, machine-learning based approach to temporally anchoring and ordering events in news. The approach achieves 84.6% accuracy in temporally anchoring events and 75.4% accuracy in partially ordering them.

Inderjeet Mani; Barry Schiffman; Jianping Zhang

2003-01-01

350

Birth order effects: A reply to Breland  

Microsoft Academic Search

Answers H. M. Breland's assertions concerning birth order effects in verbal achievement. It is argued that if birth order differences in intellectual functioning exist in childhood, they are very slight and exert at most minimal effects on adult functioning.

Carmi Schooler

1973-01-01

351

Order of the Engineer Iron Ring Ceremony  

E-print Network

of the Order . . . . . . . . . . . . . . . . . . . . . . Dr. Audra Morse Significance of the Ring . . . . . . . . . . . . . . . . . . . Dr. Jeff Woldstad Acceptance and Presentation of Obligation and Ring

Gelfond, Michael

352

Tunable fractional-order Fourier transformer  

SciTech Connect

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)

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

2006-01-31

353

Source of second order chromaticity in RHIC  

SciTech Connect

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.

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

2011-01-01

354

Scattering and order in thermotropic liquid crystals  

Microsoft Academic Search

The information on ordering in nematic and smectic liquid crystals provided by neutron and x-ray diffraction is discussed. Both orientational and positional molecular ordering is considered, the latter to a lesser extent. Theoretical treatments used to quantify molecular orientational order for rigid nematogens are introduced and the molecular field theories for nematics are described. The theory for neutron, x-ray, or

Ian William Hamley

1990-01-01

355

How to Profit from Special Orders  

ERIC Educational Resources Information Center

The Blank Check Order System was developed to cut paperwork and in-store processing costs for special order books. The customer pays in advance and the bookstore sends a blank check order to the publisher. The process and its advantages are described in detail including evaluation by publishers and college store managers. (JT)

Ollis, Don

1975-01-01

356

Order selection for vector autoregressive models  

Microsoft Academic Search

Order-selection criteria for vector autoregressive (AR) modeling are discussed. The performance of an order-selection criterion is optimal if the model of the selected order is the most accurate model in the considered set of estimated models: here vector AR models. Suboptimal performance can be a result of underfit or overfit. The Akaike (1969) information criterion (AIC) is an asymptotically unbiased

Stijn de Waele; Piet M. T. Broersen

2003-01-01

357

4 CFR 21.4 - Protective orders.  

Code of Federal Regulations, 2010 CFR

...request of a party or on its own initiative, GAO may issue a protective order...ordinarily be subject to a protective order. GAO will review in camera all information not...the order by submitting an application to GAO, with copies furnished...

2010-01-01

358

4 CFR 21.4 - Protective orders.  

Code of Federal Regulations, 2011 CFR

...request of a party or on its own initiative, GAO may issue a protective order...ordinarily be subject to a protective order. GAO will review in camera all information not...the order by submitting an application to GAO, with copies furnished...

2011-01-01

359

AIAA 99--1467 LOW ORDER AERODYNAMIC  

E-print Network

AIAA 99--1467 LOW ORDER AERODYNAMIC MODELS FOR AEROELASTIC CONTROL OF TURBOMACHINES K.E. Willcox, J of Aeronautics and Astronautics 1801 Alexander Bell Drive, Suite 500, Reston, VA 22091 #12; LOW ORDER AERODYNAMIC order aerodynamic model is developed for aeroelastic analysis of turbomachines. The proper or­ thogonal

Peraire, Jaime

360

76 FR 766 - Amtrak Emergency Routing Orders  

Federal Register 2010, 2011, 2012, 2013

...a designated e-mail address for this...Amtrak emergency routing order applications...filing an emergency routing order application...via facsimile, e-mail, or in person...filing an emergency routing order application...via facsimile, e-mail, or in...

2011-01-06

361

Cooperative Chiral Order in Random Copolymers  

Microsoft Academic Search

A new type of cooperative chiral order has been observed in polyisocyanates composed of a mixture of opposite enantiomers. The chiral order of the copolymer, measured by optical activity, is dominated by whichever enantiomer is in the majority. We present a quantitative theory for this cooperative chiral order, using a mapping of the random copolymer onto the random-field Ising model.

J. V. Selinger; R. L. B. Selinger

1996-01-01

362

A Taxonomy of Call Ordering Problems  

Microsoft Academic Search

The order of method calls in a program can present subtle problems in ensuring the program's correctness. Some of the problems have been known under different names in the open literature. These include protocols, synchronisation, re-entrance, mandatory calls, and the indirect invariant effect. However, all these problems relate to the temporal ordering of method calls. In essence, the orderings constrain

Nam Tran II; David Abramson; Christine Mingins

2004-01-01

363

Why Order Flow Explains Exchange Rates  

Microsoft Academic Search

Evans and Lyons (1999) find that order flow accounts for about two-thirds of varia- tion in the DM\\/$ rate. Though never tested, the underlying cause of order flow in their model is portfolio shifts unrelated to macroeconomic information (e.g., shifts in risk preferences or shifts in hedging demands). This paper tests whether order flow is caused (in part) by macroeconomic

Martin D. D. Evans; Richard K. Lyons

2001-01-01

364

Peculiar Ways of Ordering Commutative Rings  

Microsoft Academic Search

Henriksen and Isbell showed in 1962 that commutative rings that have nilpotent elements sometimes admit total orderings that vio- late equational laws (in the language of lattice-ordered rings) that are satisfied by all totally-ordered fields. In this paper, we construct and classify some instances of this peculiar phenomenon. We also introduce a certain construction reminiscent of algebra cohomology and show

James J. Madden

365

Introducing Word Order within the LSA Framework  

Microsoft Academic Search

The importance of word order in determining meaning is a hotly debated issue. The success of Latent Semantic Analysis (LSA) across a broad range of tasks that require semantic analysis is a testament to the importance of word choice as compared to word order. Nonetheless at the sentence level, where LSA has been less successful, word order is sometimes the

Simon Dennis

366

Lateralized temporal order judgement in dyslexia  

Microsoft Academic Search

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 temporal order of the stimuli than control participants, but did not

Elizabeth B. Liddle; Georgina M. Jackson; Chris Rorden; Stephen R. Jackson

2009-01-01

367

Birth order as a market segmentation variable  

Microsoft Academic Search

Birth order studies have an established history in the academic world just as demographics have an established history in marketing. Discusses how birth order may influence several socio-economic mechanisms and thereby influence select consumption behaviors. As a likely influence of certain consumption behaviors, birth order may be useful in segmenting certain markets. Offers a corporate advertising example to demonstrate the

Reid P. Claxton

1995-01-01

368

Methodology, Birth Order, Intelligence, and Personality.  

ERIC Educational Resources Information Center

Critiques recent research on the effects of birth order on intelligence and personality, which found that the between-family design revealed that birth order negatively related to intelligence, while the within-family design revealed that birth order was unrelated to intelligence. Suggests that it may not be intelligence that co-varies with birth…

Michalski, Richard L.; Shackelford, Todd K.

2001-01-01

369

Persisting topological order via geometric frustration  

NASA Astrophysics Data System (ADS)

We introduce a toric code model on the dice lattice which is exactly solvable and displays topological order at zero temperature. In the presence of a magnetic field, the flux dynamics is mapped to the highly frustrated transverse field Ising model on the kagome lattice. This correspondence suggests an intriguing disorder by disorder phenomenon in a topologically ordered system implying that the topological order is extremely robust due to the geometric frustration. Furthermore, a connection between fully frustrated transverse field Ising models and topologically ordered systems is demonstrated which opens an exciting physical playground due to the interplay of topological quantum order and geometric frustration.

Schmidt, Kai Phillip

2013-07-01

370

Binocular Combination of Second-Order Stimuli  

PubMed Central

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

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

2014-01-01

371

First-order inflation. [in cosmology  

NASA Technical Reports Server (NTRS)

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.

Kolb, Edward W.

1991-01-01

372

Ionic Conductivity of Block Copolymer Electrolytes in the Vicinity of Order?Disorder and Order?Order Transitions  

SciTech Connect

Order-order and order-disorder phase transitions in mixtures of poly(styrene-block-ethylene oxide) (SEO) copolymers and lithium bis(trifluoromethylsulfonimide) (LiTFSI), a common lithium salt used in polymer electrolytes, were studied using a combination of small-angle X-ray scattering (SAXS), birefringence, and ac impedance spectroscopy. The SEO/LiTFSI mixtures exhibit lamellar, hexagonally packed cylinders, and gyroid microphases. The molecular weight of the blocks and the salt concentration was adjusted to obtain order-order and order-disorder transition temperatures within the available experimental window. The ionic conductivities of the mixtures, normalized by the ionic conductivity of a 20 kg/mol homopolymer PEO sample at the salt concentration and temperature of interest, were independent of temperature, in spite of the presence of the above-mentioned phase transitions.

Wanakule, Nisita S.; Panday, Ashoutosh; Mullin, Scott A.; Gann, Eliot; Hexemer, Alex; Balsara, Nitash P.; (UCB); (LBNL)

2009-09-15

373

Tenth-Order QED Lepton Anomalous Magnetic Moment --- Eighth-Order Vertices Containing a Second-Order Vacuum Polarization  

Microsoft Academic Search

This paper reports the evaluation of the tenth-order QED contribution to the lepton g-2 from the gauge-invariant set of 2072 Feynman diagrams, called Set IV, which are obtained by inserting a second-order lepton vacuum-polarization loop into 518 eighth-order vertex diagrams of four-photon exchange type. The numerical evaluation is carried out by the adaptive-iterative Monte-Carlo integration routine vegas using the fortran

Tatsumi Aoyama; Masashi Hayakawa; Toichiro Kinoshita; Makiko Nio

2011-01-01

374

Existential Second Order Logic Expression With Horn First Order for Max Clique (Decision Version)  

E-print Network

We will show that the maximum clique problem (decision version) can be expressed in existential second order (ESO) logic, where the first order part is a Horn formula in second-order quantified predicates.

Manyem, Prabhu

2010-01-01

375

Control of Initialized Fractional-Order Systems  

NASA Technical Reports Server (NTRS)

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.

Hartly, Tom T.; Lorenzo, Carl F.

2002-01-01

376

Order Parameters for Two-Dimensional Networks  

NASA Astrophysics Data System (ADS)

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.

Kaatz, Forrest; Bultheel, Adhemar; Egami, Takeshi

2007-10-01

377

Properties of Higher Order Nonlinear Diffusion Filtering  

Microsoft Academic Search

This paper provides a mathematical analysis of higher order variational methods and nonlinear diffusion filtering for image\\u000a denoising. Besides the average grey value, it is shown that higher order diffusion filters preserve higher moments of the\\u000a initial data. While a maximum-minimum principle in general does not hold for higher order filters, we derive stability in\\u000a the 2-norm in the continuous

Stephan Didas; Joachim Weickert; Bernhard Burgeth

2009-01-01

378

Understanding fractional-order surface plasmons.  

PubMed

We show experimentally that diffraction-induced surface plasmon excitation can mimic enhanced transmission and cause a highly sensitive modulation by the coherent interference between zero-order and reflected first-order diffraction in select regions of the terahertz spectrum. Based on the study of a one-dimensional metallic grating, we obtain the physical mechanisms of the fractional-order surface plasmon resonances observed with the two-dimensional grating of the metallic hole array. PMID:22048370

Yang, Yuping; Grischkowsky, Daniel

2011-11-01

379

GEOMETRIC PRE-ORDERING ON C -ALGEBRAS  

Microsoft Academic Search

It has been a successful practice to define a canonical pre-ordering on a normed space using the inclusion of faces of its closed dual unit ball. This pre-ordering reflects some geometric property in a natural way. In this article, we will give an algebraic description of this pre-ordering in the case of com- plex C -algebras as well as that

CHI-WAI LEUNG; CHI-KEUNG NG; NGAI-CHING WONG

380

Chaos in a Fractional Order Chua System  

NASA Technical Reports Server (NTRS)

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.

Lorenzo, Carl F.; Hartley, Tom T.; Qammar, Helen Killory

1996-01-01

381

Optical method of atomic ordering estimation  

SciTech Connect

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.

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

382

Time, space, and memory for order.  

PubMed

Information about the order of items in a sequence can be conveyed either spatially or temporally. In the present investigation, we examined whether these different modes of presentation map onto compatible mental representations of serial order. We examined this issue in three immediate serial-recall experiments, in which participants recalled lists of letters in the temporal order in which they had appeared. Each letter in a to-be-remembered sequence was presented in a unique spatial position, with the order of these spatial positions progressing from either left to right or right to left. In this way, the visually presented lists contained both temporal and spatial order information. Recall of the temporal order information was more accurate with congruent spatial order information-that is, when the letters progressed from left to right, following the typical reading direction of English-than when the spatial order information was incongruent. These results suggest compatible representations of serial order when sequences are conveyed spatially and temporally. PMID:24647679

Fischer-Baum, Simon; Benjamin, Aaron S

2014-10-01

383

Bond-orientational order in liquid Si  

NASA Technical Reports Server (NTRS)

Bond-orientational order in liquid Si via Monte Carlo simulation in conjuncation with empirical two- and three-body potentials of the form proposed by Stillinger and Weber are studied. Bond-orientational order (BOO) is described in terms of combinations of spherical harmonic functions. Liquid Si is found to have pronounced short-range BOO corresponding to l = 3, as expected for a structure with local tetrahedral order. No long-range BOO is found either in the equilibrium or the supercooled liquid. When the three-body potential is artificially removed, the tetrahedral bond-orientation order disappears and the liquid assumes a close-packed structure.

Wang, Z. Q.; Stroud, D.

1991-01-01

384

Duplicate Orders: An Unintended Consequence of Computerized provider/physician order entry (CPOE) Implementation  

PubMed Central

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

Magid, S.; Forrer, C.; Shaha, S.

2012-01-01

385

Time and Order Effects on Causal Learning  

ERIC Educational Resources Information Center

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…

Alvarado, Angelica; Jara, Elvia; Vila, Javier; Rosas, Juan M.

2006-01-01

386

The Natural Order and the Human Mind  

Microsoft Academic Search

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

Steven Pimentel

387

The Ordering Analytic Approach to Hierarchical Analysis.  

ERIC Educational Resources Information Center

This state-of-the-art review describes the genesis, structure, methods, applications, limitations and goals of the ordering analytic approach to hierarchical analysis, with specific reference to its relevance and use in educational, psychology and behavioral sciences. Hierarchy is defined as an "ordering" of objects such that the relation defined…

Bart, William M.

388

OSCILLATION OF SECOND ORDER DELAY DYNAMIC EQUATIONS  

Microsoft Academic Search

In this paper we establish some sucien t con- ditions for oscillation of second order delay dynamic equations on time scales. Our results not only unify the oscillation of sec- ond order delay dieren tial and dierence equations but also are new for q-dierence equations and can be applied on any time scale. We illustrate our results with many examples.

R. P. AGARWAL; M. BOHNER; S. H. SAKER

389

Chemical Dosing and First-Order Kinetics  

ERIC Educational Resources Information Center

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,…

Hladky, Paul W.

2011-01-01

390

CHLOROPLAST GENE ORDER AND THE DIVERGENCE  

E-print Network

CHLOROPLAST GENE ORDER AND THE DIVERGENCE OF PLANTS AND ALGAE, FROM THE NORMALIZED NUMBER chloroplast genomes with known gene orders, with a focus on recently se- quenced members of the algal class and diversification of plants and algae, and their relationships with other chloroplast-containing organisms, are some

Bryant, David

391

Invariant Ordering of Item-Total Regressions  

ERIC Educational Resources Information Center

A new observable consequence of the property of invariant item ordering is presented, which holds under Mokken's double monotonicity model for dichotomous data. The observable consequence is an invariant ordering of the item-total regressions. Kendall's measure of concordance "W" and a weighted version of this measure are proposed as measures for…

Tijmstra, Jesper; Hessen, David J.; van der Heijden, Peter G. M.; Sijtsma, Klaas

2011-01-01

392

Few Fractional Order Derivatives and Their Computations  

ERIC Educational Resources Information Center

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…

Bhatta, D. D.

2007-01-01

393

A Moment Problem for Order Statistics  

Microsoft Academic Search

Necessary and sufficient conditions are given for a triangular array of numbers to be expectations of order statistics of some nonnegative random variable. Using well-known recurrence relations, the expectations of all order statistics of the largest sample size, $n$, in the triangular array, or the expectations of the smallest of every sample size up to and including $n$ are sufficient

Joseph B. Kadane

1971-01-01

394

Magnetically induced ferroelectric order in frustrated magnets  

NASA Astrophysics Data System (ADS)

Magnetoelectric coupling between magnetic and ferroelectric properties has been the object of intense study over the last four decades. Our understanding of magnetoelectric materials has been greatly enhanced by a rigorous exploration of the symmetry requirements for promoting magnetic and ferroelectric orders. Multiferroic materials, having simultaneous magnetic and ferroelectric order, have recently been proposed for incorporation into a range of spintronic devices. However, many of the multiferroics identified to date have different transition temperatures for ferroelectric and magnetic orders, leading to reduced magnetoelectric coupling strengths. I will discuss some recent experiments on several new multiferroics, including TbMnO3, DyMnO3, and Ni3V2O8. These compounds are notable because the ferroelectric transition is coincident with magnetic ordering which leads to very large magnetoelectric couplings and large magnetocapacitive effects. Furthermore, using external magnetic fields to tune the magnetic structure has a pronounced effect on ferroelectricity in these systems. This allows us to destroy or promote ferroelectric order magnetically. While similar effects have been observed previously, these multiferroics remain poorly understood. I will present a model developed to explain the multiferroic order in Ni3V2O8, in which the magnetic order spontaneously breaks inversion symmetry, allowing for the development of ferroelectricity. This magnetically-induced ferroelectric order is expected to appear in a wide range of antiferromagnets, and offers a new approach for designing and understanding multiferroic materials.

Lawes, Gavin

2005-03-01

395

A contamination model for approximate stochastic order.  

E-print Network

satisfy the stochastic ordering. The minimal level of contam- ination that makes this approximate modelA contamination model for approximate stochastic order. Pedro C. ´Alvarez-Esteban1 , E. del Barrio1 to believe that a certain variable is somehow smaller than other. Instead of considering this rigid model

Cuesta, Juan Antonio

396

Using Reflection to Develop Higher Order Processes  

ERIC Educational Resources Information Center

The main purpose of this study was to look at how we used specific writing assignments in our courses to encourage metacognitive reflection in order to increase the learning that takes place. The study also aimed to aid in the development of higher order processing skills through the development of student reflection. The students involved in the…

Lerch, Carol; Bilics, Andrea; Colley, Binta

2006-01-01

397

General frailty model and stochastic orderings  

Microsoft Academic Search

In this paper, we propose a general frailty model and develop its properties including some results for stochastic comparisons. More specifically, our main results lie in seeing how the well known stochastic orderings between distributions of two frailties translate into the orderings between the corresponding survival functions. These results are used to obtain the properties of the classical multiplicative frailty

Ramesh C. Gupta; Rameshwar D. Gupta

2009-01-01

398

Supramolecular approaches towards ordered polymer materials.  

PubMed

Controlled organization of polymer chains into ordered structures is highly important to tune or enhance the properties of the polymeric materials. A supramolecular approach using host-guest chemistry has allowed rational design of chain assemblies with many functional properties. Nanoporous materials with ordered channel structures are particularly useful for attaining precise assemblies of polymer chains through nanoconfinement. PMID:24443289

Uemura, Takashi

2014-02-01

399

40 CFR 90.503 - Test orders.  

Code of Federal Regulations, 2010 CFR

...SPARK-IGNITION ENGINES AT OR BELOW 19 KILOWATTS Selective Enforcement Auditing § 90.503 Test orders. (a) The Administrator shall...shall not issue to a manufacturer more Selective Enforcement Auditing (SEA) test orders than an annual limit determined by...

2010-07-01

400

Third Order Elastic Constants of Ammonium Chloride  

Microsoft Academic Search

Sound velocities along several directions in ammonium chloride crystals have been measured under hydrostatic and uniaxial pressures by means of an ultrasonic method. Second order elastic constants and their pressure derivatives were evaluated in the vicinity of the phase transition point in disordered phase, and third order elastic constants were calculated from the data. It was found that the absolute

Haruyasu Yamashita; Itaru Tatsuzaki

1984-01-01

401

Serial Order: A Parallel Distributed Processing Approach.  

ERIC Educational Resources Information Center

Human behavior shows a variety of serially ordered action sequences. This paper presents a theory of serial order which describes how sequences of actions might be learned and performed. In this theory, parallel interactions across time (coarticulation) and parallel interactions across space (dual-task interference) are viewed as two aspects of a…

Jordan, Michael I.

402

Signal processing with higher-order spectra  

Microsoft Academic Search

The strengths and limitations of correlation-based signal processing methods are discussed. The definitions, properties, and computation of higher-order statistics and spectra, with emphasis on the bispectrum and trispectrum are presented. Parametric and nonparametric expressions for polyspectra of linear and nonlinear processes are described. The applications of higher-order spectra in signal processing are discussed

C. L. Nikias; J. M. Mendel

1993-01-01

403

Efficient message ordering in dynamic networks  

Microsoft Academic Search

We present an algorithm for totally ordering messagesin the face of network partitions and site failures. Thealgorithm always allows a majority of connected processorsin the network to make progress (i.e. to order messages),if they remain connected for sufficiently long, regardless ofpast failures. Furthermore, our algorithm always allowsprocessors to initiate messages, even when they are notmembers of a connected majority component

Idit Keidar; Danny Dolev

1996-01-01

404

Lifted First-Order Probabilistic Inference  

Microsoft Academic Search

Most probabilistic inference algorithms are speci- fied and processed on a propositional level. In the last decade, many proposals for algorithms accept- ing first-order specifications have been presented, but in the inference stage they still operate on a mostly propositional representation level. (Poole, 2003) presented a method to perform inference di- rectly on the first-order level, but this method is

Rodrigo De Salvo Braz; Eyal Amir; Dan Roth

2005-01-01

405

Order completion accuracy - a pragmatic approach  

Microsoft Academic Search

The practice of measuring the efficacy and error rates in meeting customers’ orders is often restricted to the single activity of order picking. Extends the view that picking is just one of several activities undertaken in delivering goods to customers, and all activities need to be examined to give a true picture of error rates. To this end Vauxhall Aftersales

Michael Galley

1997-01-01

406

More Spectral Theory in Ordered Banach Algebras  

Microsoft Academic Search

We continue our development of spectral theory for positive elements in an ordered Banach algebra. In particular we provide a suitable version of the Krein-Rutman theorem, obtain some results concerning the peripheral spectrum of a positive element and provide a characterisation of positive quasi inessential elements, in the context of an ordered Banach algebra.

H. Raubenheimer

1997-01-01

407

Order Statistics Combiners For Neural Classifiers  

Microsoft Academic Search

: Several researchers have shown that linearly combining outputs of multiple neural classifiersresults in better performance for many applications. In this paper we introduce a family of order statisticscombiners as an alternative to linear combiners. We show analytically that the selection of the median, themaximum and in general, the ithorder statistic improves classification performance. Specifically, we showthat order statistics combiners

Kagan Tumer; Joydeep Ghosh

1995-01-01

408

Parallelizing and De-parallelizing Elimination Orders.  

National Technical Information Service (NTIS)

The order in which the variables of a linear system are processed determines the total amounts of fill and work to perform LU decomposition on the system. We identify a trade off between the amounts of fill and work for a given order and the parallelism i...

C. F. Bornstein

1998-01-01

409

Birth Order, Family Size and Educational Attainment  

Microsoft Academic Search

This paper investigates the effect of sibship size and birth order on educational attainment, for the United States and the Netherlands. An instrumental variables approach is used to identify the effect of sibship 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

Monique de Haan

2005-01-01

410

Birth Order, Family Size and Educational Attainment  

ERIC Educational Resources Information Center

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…

de Haan, Monique

2010-01-01

411

Birth order effects: Not here, not now  

Microsoft Academic Search

A review of birth order effects, which considers previously reported and unreported data and recently hypothesized biases arising from long-term population trends, reveals (a) almost no reliable evidence for birth order effects among males living in the United States in the middle 1960s, and (b) only a marginal increase in such evidence when restrictions on time, place, and sex are

Carmi Schooler

1972-01-01

412

Birth Order: How It Affects Children.  

ERIC Educational Resources Information Center

Examines the effect of birth order on child development, noting that spacing of children, gender, family size, and family configuration all play a role in determining what effect birth order will have. The article looks at various traits of firstborn, middle, lastborn, and only children. (SM)

Bauer, Karen L.

1992-01-01

413

Birth order, family size and educational attainment  

Microsoft Academic Search

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 with years

Monique de Haan

2010-01-01

414

Birth order effects: A reply to Schooler  

Microsoft Academic Search

Replies to C. Schooler's criticisms regarding birth order studies by presenting evidence to support Breland's contention that birth order effects on verbal achievement do exist, and that these are not caused by either population biases or socioeconomic status differences. (22 ref.)

Hunter M. Breland

1973-01-01

415

Perception of Serial Order in Infants  

ERIC Educational Resources Information Center

Serial order is fundamental to perception, cognition and behavioral action. Three experiments investigated infants' perception, learning and discrimination of serial order. Four- and 8-month-old infants were habituated to three sequentially moving objects making visible and audible impacts and then were tested on separate test trials for their…

Lewkowicz, David J.

2004-01-01

416

17 CFR 242.605 - Disclosure of order execution information.  

Code of Federal Regulations, 2010 CFR

...of information: (i) For market orders, marketable limit orders, inside-the-quote limit orders, at-the-quote limit orders, and near-the-quote limit orders: (A) The number of covered orders; (B) The cumulative...

2010-04-01

417

17 CFR 201.141 - Orders and decisions: Service of orders instituting proceedings and other orders and decisions.  

Code of Federal Regulations, 2011 CFR

...handing a copy of the order to the individual; or leaving a copy at the individual's...service is made in person, the certificate of service shall state, if...appointment to receive service, the certificate of service shall be...

2011-04-01

418

17 CFR 201.141 - Orders and decisions: Service of orders instituting proceedings and other orders and decisions.  

Code of Federal Regulations, 2010 CFR

...handing a copy of the order to the individual; or leaving a copy at the individual's...service is made in person, the certificate of service shall state, if...appointment to receive service, the certificate of service shall be...

2010-04-01

419

17 CFR 201.141 - Orders and decisions: Service of orders instituting proceedings and other orders and decisions.  

...handing a copy of the order to the individual; or leaving a copy at the individual's...service is made in person, the certificate of service shall state, if...appointment to receive service, the certificate of service shall be...

2014-04-01

420

17 CFR 201.141 - Orders and decisions: Service of orders instituting proceedings and other orders and decisions.  

Code of Federal Regulations, 2013 CFR

...handing a copy of the order to the individual; or leaving a copy at the individual's...service is made in person, the certificate of service shall state, if...appointment to receive service, the certificate of service shall be...

2013-04-01

421

17 CFR 201.141 - Orders and decisions: Service of orders instituting proceedings and other orders and decisions.  

Code of Federal Regulations, 2012 CFR

...handing a copy of the order to the individual; or leaving a copy at the individual's...service is made in person, the certificate of service shall state, if...appointment to receive service, the certificate of service shall be...

2012-04-01

422

Higher order equations of motion and gravity  

NASA Astrophysics Data System (ADS)

Standard fundamental equations of motion for point particles are of second order in the time derivative. Here we are exploring the consequences of fundamental equations of motion with an additional small even higher order term to the standard formulation. This is related to two issues: (i) higher order equations of motion will have influence on the definition of the structure of possible interactions and in particular of the gravitational interaction, and (ii) such equations of motion provide a framework to test the validity of Newton’s second law which is the basis for the definition of forces but which assumes from the very beginning that the fundamental equations of motion are of second order. We will show that starting with our generalized equations of motions it is possible to introduce the space-time metric describing the gravitational interaction by means of a standard gauge principle. Another main result within our model of even higher order derivatives is that for slowly varying and smooth fields the higher order derivatives either lead to runaway solutions or induces a zitterbewegung. We confront this higher order scheme with experimental data.

Lämmerzahl, Claus; Rademaker, Patricia

2012-12-01

423

Roughness in lattice ordered effect algebras.  

PubMed

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

Xin, Xiao Long; Hua, Xiu Juan; Zhu, Xi

2014-01-01

424

The second-order gravitational red shift  

NASA Technical Reports Server (NTRS)

The direct measurement of the nonlinear term of the gravitational field equations by using very stable clocks is discussed along with measuring the perhelion advance of a planet or satellite. These are considered measurements of the second-order gravitational red shift. The exact expression for the frequency shift of light in a gravitational field is derived. Other topics discussed include: The Doppler-cancelling technique; the second-order red shift in a spherically symmetric gravitational field; finite signal transit time; and the reality and interpretation of coordinates in the second-order red shift experiment.

Jaffe, J.

1973-01-01

425

Magnetic fields from second-order interactions  

E-print Network

It is well known that when two types of perturbations interact in cosmological perturbation theory, the interaction may lead to the generation of a third type. In this article we discuss the generation of magnetic fields from such interactions. We determine conditions under which the interaction of a first-order magnetic field with a first-order scalar-or vector-, or tensor-perturbations would lead to the generation of second order magnetic field. The analysis is done in a covariant-index-free approach, but could be done in the standard covariant indexed-approach.

Bob Osano

2014-03-21

426

Ranking Fuzzy Numbers Based on Lexicographical Ordering  

E-print Network

Abstract—Although so far, many methods for ranking fuzzy numbers have been discussed broadly, most of them contained some shortcomings, such as requirement of complicated calculations, inconsistency with human intuition and indiscrimination. The motivation of this study is to develop a model for ranking fuzzy numbers based on the lexicographical ordering which provides decision-makers with a simple and efficient algorithm to generate an ordering founded on a precedence. The main emphasis here is put on the ease of use and reliability. The effectiveness of the proposed method is finally demonstrated by including a comprehensive comparing different ranking methods with the present one. Keywords—Ranking fuzzy numbers, Lexicographical ordering. I.

B. Farhadinia

427

Make Your Own (Order of Operations)  

NSDL National Science Digital Library

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.

2010-01-01

428

Topological order following a quantum quench  

SciTech Connect

We determine the conditions under which topological order survives a rapid quantum quench. Specifically, we consider the case where a quantum spin system is prepared in the ground state of the toric code model and, after the quench, it evolves with a Hamiltonian that does not support topological order. We provide analytical results supported by numerical evidence for a variety of quench Hamiltonians. The robustness of topological order under nonequilibrium situations is tested by studying the topological entropy and a dynamical measure, which makes use of the similarity between partial density matrices obtained from different topological sectors.

Tsomokos, Dimitris I. [School of Physics and Astronomy, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom); Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy); Department of Mathematics, Royal Holloway, University of London, Egham TW20 0EX (United Kingdom); Hamma, Alioscia [Perimeter Institute for Theoretical Physics, 31 Caroline Street N, Waterloo, Ontario, Canada N2L 2Y5 (Canada); Zhang Wen; Haas, Stephan [Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089 (United States); Fazio, Rosario [Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy); Center for Quantum Technologies, National University of Singapore, Singapore (Singapore)

2009-12-15

429

Thermal Conductivity of Ordered Molecular Water  

SciTech Connect

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.

W Evans; J Fish; P Keblinski

2006-02-16

430

Local orientational order in the Stockmayer liquid  

E-print Network

Phase behaviour of the Stockmayer fluid is studied with a method similar to the Monte-Carlo annealing scheme. We introduce a novel order parameter which is sensitive to the local co-orientation of the dipoles of particles in the fluid. We exhibit a phase diagram based on the behaviour of the order parameter in the density region 0.1 \\leq {\\rho}\\ast \\leq 0.32. Specifically, we observe and analyse a second order locally disordered fluid \\rightarrow locally oriented fluid phase transition.

Veniamin Blinov

2012-03-07

431

First and Second Order Perturbations of Hypersurfaces  

E-print Network

In this paper we find the first and second order perturbations of the induced metric and the extrinsic curvature of a non-degenerate hypersurface $\\Sigma$ in a spacetime $(M,g)$, when the metric $g$ is perturbed arbitrarily to second order and the hypersurface itself is allowed to change perturbatively (i.e. to move within spacetime) also to second order. The results are fully general and hold in arbitrary dimensions and signature. An application of these results for the perturbed matching theory between spacetimes is presented.

Marc Mars

2005-07-01

432

Nucleation of Ordered Phases in Block Copolymers  

NASA Astrophysics Data System (ADS)

Nucleation of various ordered phases in block copolymers is studied by examining the free-energy landscape within the self-consistent field theory. The minimum energy path (MEP) connecting two ordered phases is computed using a recently developed string method. The shape, size, and free-energy barrier of critical nuclei are obtained from the MEP, providing information about the emergence of a stable ordered phase from a metastable phase. In particular, structural evolution of embryonic gyroid nucleus is predicted to follow two possible MEPs, revealing an interesting transition pathway with an intermediate perforated layered structure.

Cheng, Xiuyuan; Lin, Ling; E, Weinan; Zhang, Pingwen; Shi, An-Chang

2010-04-01

433

Order formation processes of complex systems including different parity order parameters  

NASA Astrophysics Data System (ADS)

In the present study, we focus on the parity of the order parameters and clarify the order formation process in a system including two order parameters. Each order parameter shows different parity under a gauge transformation, namely even and odd order parameters. For example, in a spin-glass model, the even order parameter corresponds to the spin-glass order parameter while the odd one corresponds to the magnetization. We introduce phenomenologically a set of Langevin equations to express the ordering process under a white Gaussian noise. Using two kinds of Fokker-Planck equations, we analyze the order formation process and the entropy production. Furthermore, we show the noise dependence of the onset time.

Hashizume, Yoichiro; Suzuki, Masuo; Okamura, Soichiro

2014-06-01

434

Order-splitting and long-memory in an order-driven market  

NASA Astrophysics Data System (ADS)

Recent empirical research has documented long-memories of trading volume, volatility, and order-signs in stock markets. We conjecture that traders' order-splitting is related to these empirical features. This study conducts simulations on an order-driven economy where agents split their orders into small pieces and execute piece by piece to reduce price impact. We demonstrate that we can replicate the long-memories in our order-splitting economy and conclude that order-splitting can be a possible cause for these empirical properties.

Yamamoto, R.; LeBaron, B.

2010-01-01

435

21 CFR 1315.62 - Final order.  

Code of Federal Regulations, 2010 CFR

...62 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE IMPORTATION AND PRODUCTION QUOTAS FOR EPHEDRINE, PSEUDOEPHEDRINE, AND PHENYLPROPANOLAMINE Hearings § 1315.62 Final order. As soon as practicable...

2010-04-01

436

21 CFR 1315.62 - Final order.  

...62 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE IMPORTATION AND PRODUCTION QUOTAS FOR EPHEDRINE, PSEUDOEPHEDRINE, AND PHENYLPROPANOLAMINE Hearings § 1315.62 Final order. As soon as practicable...

2014-04-01

437

21 CFR 1315.62 - Final order.  

Code of Federal Regulations, 2011 CFR

...62 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE IMPORTATION AND PRODUCTION QUOTAS FOR EPHEDRINE, PSEUDOEPHEDRINE, AND PHENYLPROPANOLAMINE Hearings § 1315.62 Final order. As soon as practicable...

2011-04-01

438

21 CFR 1315.62 - Final order.  

Code of Federal Regulations, 2013 CFR

...62 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE IMPORTATION AND PRODUCTION QUOTAS FOR EPHEDRINE, PSEUDOEPHEDRINE, AND PHENYLPROPANOLAMINE Hearings § 1315.62 Final order. As soon as practicable...

2013-04-01

439

21 CFR 1315.62 - Final order.  

Code of Federal Regulations, 2012 CFR

...62 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE IMPORTATION AND PRODUCTION QUOTAS FOR EPHEDRINE, PSEUDOEPHEDRINE, AND PHENYLPROPANOLAMINE Hearings § 1315.62 Final order. As soon as practicable...

2012-04-01

440

Low Order-Value Optimization and applications  

E-print Network

Oct 24, 2005 ... an interesting tool for robust estimation of parameters of nonlinear models. ... Key words: Order-Value Optimization, algorithms, convergence, robust ..... if xk+1 = xk + tkdk but, for enhancing the probability of convergence to.

2007-01-05

441

Critical dimensions and higher order Sobolev inequalities  

E-print Network

Critical dimensions and higher order Sobolev Abstract Pucci and Serrin [21] conjecture that certain space dimensions behave "critically* *he "presumably" critical dimensions. Crucial tools are positivity results a* *nd

Grunau, Hans-Christoph

442

Nonlinear spectroscopic studies of interfacial molecular ordering.  

National Technical Information Service (NTIS)

The second order nonlinear optical processes of second harmonic generation and sum frequency generation are powerful new probes of surfaces. They possess unusual surface sensitivity due to the symmetry properties of the nonlinear susceptibility. In partic...

R. Superfine

1991-01-01

443

10 CFR 2.202 - Orders.  

...COMMISSION AGENCY RULES OF PRACTICE AND PROCEDURE Procedure...immediate effectiveness, is not based on adequate evidence but on mere suspicion, unfounded...reasons why the order is not based on adequate evidence and must be accompanied...

2014-01-01

444

10 CFR 2.202 - Orders.  

Code of Federal Regulations, 2010 CFR

...REGULATORY COMMISSION RULES OF PRACTICE FOR DOMESTIC LICENSING PROCEEDINGS...immediate effectiveness, is not based on adequate evidence but on mere suspicion, unfounded...reasons why the order is not based on adequate evidence and must be accompanied...

2010-01-01

445

46 CFR 201.74 - Declaratory orders.  

Code of Federal Regulations, 2011 CFR

...a declaratory order to terminate a proceeding or to remove uncertainty. Petitions for the issuance thereof shall state clearly and concisely the nature of the controversy or uncertainty, shall cite the statutory authority involved, shall...

2011-10-01

446

36 CFR 261.50 - Orders.  

Code of Federal Regulations, 2010 CFR

...Orders. (a) The Chief, each Regional Forester, each Experiment Station Director, the Administrator of the Lake Tahoe...thereof. (b) The Chief, each Regional Forester, each Experiment Station Director, the Administrator of the Lake...

2010-07-01

447

36 CFR 261.50 - Orders.  

Code of Federal Regulations, 2011 CFR

...Orders. (a) The Chief, each Regional Forester, each Experiment Station Director, the Administrator of the Lake Tahoe...thereof. (b) The Chief, each Regional Forester, each Experiment Station Director, the Administrator of the Lake...

2011-07-01

448

7 CFR 29.1045 - Order (case).  

Code of Federal Regulations, 2010 CFR

...AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Official Standard Grades for Flue-Cured Tobacco (u.s. Types 11, 12, 13, 14 and Foreign Type 92) § 29.1045 Order (case). The state of...

2010-01-01

449

30 CFR 843.11 - Cessation orders.  

Code of Federal Regulations, 2010 CFR

...without a valid surface coal mining permit constitute a condition...exploration or surface coal mining and reclamation operations...exploration or surface coal mining and reclamation operation to...The order shall remain in effect until the condition,...

2010-07-01

450

30 CFR 843.11 - Cessation orders.  

Code of Federal Regulations, 2012 CFR

...without a valid surface coal mining permit constitute a condition...exploration or surface coal mining and reclamation operations...exploration or surface coal mining and reclamation operation to...The order shall remain in effect until the condition,...

2012-07-01

451

30 CFR 843.11 - Cessation orders.  

Code of Federal Regulations, 2013 CFR

...without a valid surface coal mining permit constitute a condition...exploration or surface coal mining and reclamation operations...exploration or surface coal mining and reclamation operation to...The order shall remain in effect until the condition,...

2013-07-01

452

30 CFR 843.11 - Cessation orders.  

...without a valid surface coal mining permit constitute a condition...exploration or surface coal mining and reclamation operations...exploration or surface coal mining and reclamation operation to...The order shall remain in effect until the condition,...

2014-07-01

453

30 CFR 843.11 - Cessation orders.  

Code of Federal Regulations, 2011 CFR

...without a valid surface coal mining permit constitute a condition...exploration or surface coal mining and reclamation operations...exploration or surface coal mining and reclamation operation to...The order shall remain in effect until the condition,...

2011-07-01

454

Splines of complex order: An introduction  

NASA Astrophysics Data System (ADS)

We give a short introduction to complex B-splines, highlight their relations to difference operators and Dirichlet means, and introduce complex B-spline surfaces. Finally, we present the new class of splines of complex order.

Massopust, Peter

2012-09-01

455

Synergism in Order Formation from Unstable Fluctuations  

NASA Astrophysics Data System (ADS)

The present paper reviews some general aspects of the stochastic analysis performed by the author in the field of statistical physics, particularly concerning the order formation from unstable states. First, a brief review and some new results are given on the generalization of the Itô-type and Stratonovich-type stochastic integrals. Their physical meaning is also discussed form the viewpoint of symmetry. Secondly, Kubo's stochastic Liouville equation is presented from the viewpoint of separation of procedures, to give a simple derivation of the Fokker-Planck equation. Thirdly, the scaling theory of order formation from the unstable point is re-formulated by introducing here a new order parameter to characterize macroscopic order formation and to clarify the synergetic effect of the initial fluctuation, random noise and nonlinearity. Finally, some discussions are given, particularly concerning applications of the Hida calculus based on the Gelfand triplet space.

Suzuki, Masuo

456

Metric Independent Analysis of Second Order Stresses  

E-print Network

A metric independent geometric analysis of second order stresses in continuum mechanics is presented. For a vector bundle $W$ over the $n$-dimensional space manifold, the value of a second order stress at a point $x$ in space is represented mathematically by a linear mapping between the second jet space of $W$ at $x$ and the space of $n$-alternating tensors at $x$. While only limited analysis can be performed on second order stresses as such, they may be represented by non-holonomic stresses, whose values are linear mapping defined on the iterated jet bundle, $J^{1}(J^{1}W)$, and for which an iterated analysis for first order stresses may be performed. As expected, we obtain the surface interactions on the boundaries of regions in space.

Reuven Segev

2014-02-13

457

45 CFR 32.6 - Withholding order.  

Code of Federal Regulations, 2012 CFR

...to Employer & Important Notice to Employer,” an SF-329B “Wage Garnishment Order,” an SF-329C “Wage Garnishment Worksheet,” and an SF-329D “Employer Certification,” to the debtor's employer within 30 days after the debtor fails to...

2012-10-01

458

45 CFR 32.6 - Withholding order.  

Code of Federal Regulations, 2010 CFR

...to Employer & Important Notice to Employer,” an SF-329B “Wage Garnishment Order,” an SF-329C “Wage Garnishment Worksheet,” and an SF-329D “Employer Certification,” to the debtor's employer within 30 days after the debtor fails to...

2010-10-01

459

Process, Order and Stability in Veblen  

E-print Network

of Veblen’s thinking on these and related matters. Keywords: Process, order, stability, history of thought, economic science, institution, habit, habituation, human nature, evolution, natural selection, Darwin, Spencer, Mendel. JEL Codes: A1, A...

Lawson, Tony

2014-01-01

460

High-order beam optics: An overview  

SciTech Connect

Beam-transport codes have been around for as long as thirty years and high-order codes, second-order at least, for close to twenty years. Before this period of design-code development, there was considerable high-order treatment, but it was almost entirely analytical. History has a way of repeating itself, and the current excitement in the field of high-order optics is based on the application of Lie algebra and the so-called differential algebra to beam-transport codes, both of which are highly analytical in foundation. Some of the main design tools available today will be described, giving a little of their history, and will conclude by trying to convey some of the excitement in the field through a brief description of Lie and differential algebra. 30 refs., 7 figs.

Heighway, E.A.

1988-01-01

461

Theoretical study on high order interior tomography  

PubMed Central

In this paper, we study a new type of high order interior problems characterized by high order differential phase shift measurement. This problem is encountered in local x-ray phase-contrast tomography. Here we extend our previous theoretical framework from interior CT to interior differential phase-contrast tomography, and establish the solution uniqueness in this context. We employ the analytic continuation method and high order total variation minimization which we developed in our previous work for interior CT, and prove that an image in a region of interest (ROI) can be uniquely reconstructed from truncated high order differential projection data if the image is known a priori in a sub-region of the ROI or the image is piecewise polynomial in the ROI. Preliminary numerical experiments support the theoretical finding. PMID:23324783

Yang, Jiansheng; Cong, Wenxiang; Jiang, Ming; Wang, Ge

2013-01-01

462

Order and chaos : articulating support, housing transformation  

E-print Network

This thesis presents an exploration on the theme of order and chaos, as a formal and social phenomenon, particularly as it relates to housing. The work stems from an attraction to the messy vitality we find in certain ...

Boehm, William Hollister

1990-01-01

463

20 CFR 901.71 - Special orders.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Special orders. 901.71 Section 901.71 Employees' Benefits JOINT BOARD FOR THE ENROLLMENT OF ACTUARIES REGULATIONS GOVERNING THE PERFORMANCE OF ACTUARIAL SERVICES UNDER THE EMPLOYEE RETIREMENT INCOME SECURITY ACT OF 1974...

2010-04-01

464

Creating atomic order in semiconductors quantum dots  

E-print Network

1 Creating atomic order in semiconductors quantum dots Peter Moeck Department of Physics (MC 273 in the invention of the integrated circuit" Jack S. Kilby (½): creating first integrated circuit in Ge, September

Moeck, Peter

465

7 CFR 966.110 - Order.  

Code of Federal Regulations, 2011 CFR

...AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE TOMATOES GROWN IN FLORIDA Rules and Regulations Definitions ...966 (§§ 966.1 to 966.92) regulating the handling of tomatoes grown in...

2011-01-01

466

7 CFR 966.110 - Order.  

Code of Federal Regulations, 2012 CFR

...AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE TOMATOES GROWN IN FLORIDA Rules and Regulations Definitions ...966 (§§ 966.1 to 966.92) regulating the handling of tomatoes grown in...

2012-01-01

467

7 CFR 966.110 - Order.  

Code of Federal Regulations, 2010 CFR

...AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE TOMATOES GROWN IN FLORIDA Rules and Regulations Definitions ...966 (§§ 966.1 to 966.92) regulating the handling of tomatoes grown in...

2010-01-01

468

77 FR 60379 - Order Denying Export Privileges  

Federal Register 2010, 2011, 2012, 2013

...Export Privileges In the Matter of: Phillip Andro Jamison currently incarcerated at: Register...Southern District of California, Phillip Andro Jamison (``Jamison'') was convicted...Ordered I. Until November 4, 2021, Phillip Andro Jamison, with last known addresses...

2012-10-03

469

Tensorial Calibration. 2. Second Order Tensorial Calibration.  

National Technical Information Service (NTIS)

Tensorial calibration provides a useful approach to calibration in general. For calibration of instruments that produce two dimensional (second order) data arrays of data per sample, tensorial concepts are a natural way of solving the calibration problems...

E. Sanchez, B. R. Kowalski

1987-01-01

470

High order difference methods for parabolic equations  

E-print Network

HIGH ORDER DIFFERENCE METHODS FOR PARABOLIC E(PATIONS A Thesis by Daniel Alan Matuska Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1971 Ma...)or Sub]ect: Mathematics HIGH ORDER DIFFERENCE METHODS FOR PARABOLIC EQUATIONS A Thesis by Daniel Alan Matuska Approved as to style and content by: Pc~ &~ (Chairman of Committee) (Head of Department) (Member) C . (Member) (Member) (Member...

Matuska, Daniel Alan

2012-06-07

471

4.NBT Ordering 4-digit numbers  

NSDL National Science Digital Library

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: Arrange these numbers in increasing order, beginning with the least. 2400 \\ 4002 \\ 2040 \\ 420 \\ 2004 Arrange these numbers in decreasing order, beginni...

472

First-order ball-bearing kinematics  

NASA Technical Reports Server (NTRS)

Two first-order equations are given connecting geometry and internal motions in an angular-contact ball bearing. Total speed, kinematic equivalence, basic speed ratio, and modal speed ratio are defined and discussed; charts are given for the speed ratios covering all bearings and all rotational modes. Instances where specific first-order assumptions might fail are discussed, and the resulting effects on bearing performance reviewed.

Kingsbury, E.

1985-01-01

473

Documentation of the Fourth Order Band Model  

NASA Technical Reports Server (NTRS)

A general circulation model is presented which uses quadratically conservative, fourth order horizontal space differences on an unstaggered grid and second order vertical space differences with a forward-backward or a smooth leap frog time scheme to solve the primitive equations of motion. The dynamic equations for motion, finite difference equations, a discussion of the structure and flow chart of the program code, a program listing, and three relevent papers are given.

Kalnay-Rivas, E.; Hoitsma, D.

1979-01-01

474

Higher-Order Knowledge in Computer Games  

Microsoft Academic Search

Our main aim is to raise awareness of higher-order knowledge, i.e. knowledge about knowledge, as an issue in simulating realistic non-player characters in computer games. We motivate the importance of higher-order knowledge with arguments, as well as a few examples.We survey existing games and literature to show that this issue is currently neglected. We also refer to our earlier work

Andreas Witzel; Jonathan A. Zvesper

2008-01-01

475

Third-Order Elastic Constants of Calcite  

Microsoft Academic Search

The third-order elastic constants of calcite at 0°C have been determined by measuring the stress and temperature dependence of sound velocities in it by means of an improved pulse-superposition method (average sensitivity of 2×10-7). Within the small temperature range considered (about 2°C), a nonlinear temperature dependence which varies with pressure has been clearly observed. Out of 14 independent third-order moduli,

H. Kaga

1968-01-01

476

Third-Order Elastic Constants of Aluminum  

Microsoft Academic Search

The complete set of six third-order elastic constants of single-crystal Al has been experimentally determined by measuring both hydrostatic-pressure and uniaxial-stress derivatives of the natural sound velocities using a two-specimen interferometric technique. The specimens were neutron-irradiated to eliminate dislocation effects from the uniaxial experiments. A self-consistent set of hydrostatic-pressure derivatives of the second-order elastic constants has been calculated from the

J. F. Thomas

1968-01-01

477

Gastric Cancer Data Mining with Ordered Information  

Microsoft Academic Search

\\u000a Ordered information is a kind of useful background knowledge to guide a discovery process toward finding different types of novel rules and improving\\u000a their quality for many real world data mining tasks. In the paper, we investigate ways of using ordered information for gastric\\u000a cancer data mining, based on rough set theory and granular computing. With respect to the notion

Ning Zhong; Ju-Zhen Dong; Yiyu Yao; Setsuo Ohsuga

2002-01-01

478

Order Flow and Exchange Rate Dynamics  

Microsoft Academic Search

Macroeconomic models of nominal exchange rates perform poorly. In sample, R2 statistics as high as 10 percent are rare. Out of sample, these models are typically out-forecast by a na‹ve random walk. This paper presents a model of a new kind. Instead of relying exclusively on macroeconomic determinants, the model includes a determinant from the field of microstructure-order flow. Order

Martin D. D. Evans; Richard K. Lyons

1999-01-01

479

CONFERENCES AND SYMPOSIA: Toroidal ordering in crystals  

NASA Astrophysics Data System (ADS)

Phase transitions to ordered states, which correspond to the toroidal family of multipoles known in electrodynamics, are discussed. The ordering of toroidal moments may either occur simultaneously with their formation (as in superconductivity) or may follow it (at lower temperatures). In addition to electrodynamic toroidal moments corresponding to either poloidal charge currents or a spin configuration, a toroidal state corresponding to poloidal spin currents is possible.

Kopaev, Yurii V.

2009-11-01

480

Higher-order awareness, misrepresentation and function  

PubMed Central

Conscious mental states are states we are in some way aware of. I compare higher-order theories of consciousness, which explain consciousness by appeal to such higher-order awareness (HOA), and first-order theories, which do not, and I argue that higher-order theories have substantial explanatory advantages. The higher-order nature of our awareness of our conscious states suggests an analogy with the metacognition that figures in the regulation of psychological processes and behaviour. I argue that, although both consciousness and metacognition involve higher-order psychological states, they have little more in common. One thing they do share is the possibility of misrepresentation; just as metacognitive processing can misrepresent one's cognitive states and abilities, so the HOA in virtue of which one's mental states are conscious can, and sometimes does, misdescribe those states. A striking difference between the two, however, has to do with utility for psychological processing. Metacognition has considerable benefit for psychological processing; in contrast, it is unlikely that there is much, if any, utility to mental states' being conscious over and above the utility those states have when they are not conscious. PMID:22492758

Rosenthal, David

2012-01-01

481

Effect upon universal order of Hubble expansion  

NASA Astrophysics Data System (ADS)

The level of order R in a spherical system of radius r0 with a probability amplitude function ?(x),x=r,?,? obeys R=(1/2)r02I, where I=4?dx| is its Fisher information level. We show that a flat space universe obeying the Robertson-Walker metric has an invariant value of the order as it undergoes either uniform Hubble expansion or contraction. This means that Hubble expansion per se does not cause a loss of universal order as time progresses. Instead, coarse graining processes characterizing decoherence and friction might cause a loss of order. Alternatively, looking backward in time, i.e. under Hubble contraction, as the big bang is approached and the Hubble radius r0 approaches small values, the structure in the amplitude function ?(x) becomes ever more densely packed, increasing all local slopes ?? and causing the Fisher information I to approach unboundedly large values. As a speculation, this ever-well locates the initial position of the universe in a larger, multiverse. We define a measure of order or complexity proportional to the Fisher information. The measure is applied to our flat-space, dust and gas dominated, universe. Despite the universe’s relentless, ever-accelerating Hubble expansion, its level of order is found to remain constant.

Frieden, B. R.; Plastino, A.; Plastino, A. R.

2012-01-01

482

Enhancement of Nematic Order and Global Phase Diagram of a Lattice Model for Coupled Nematic Systems  

NASA Astrophysics Data System (ADS)

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.

Liarte, Danilo Barbosa; Salinas, Silvio Roberto

2012-08-01

483

Order and healing: the concept of order and its importance in the conceptualization of healing.  

PubMed

This paper concerns the notion of order and its role in the conceptualization of healing, and therefore its importance to healing itself. It proposes a model of healing in which order is central. The paper begins with an example drawn from Javanese mystical practices which are based upon the concept of the unity of the human and natural orders. The Javanese case provides a metaphor for an expanded notion of order. This prefigures a consideration of the nature of the concept of order in medical anthropology, science, and medicine. The importance of the notion of analogy (and metaphor) in the concept of order and how order may be simultaneously conceptualized in both cognitive and biological domains is also discussed in the paper. The perspective on order and healing developed here goes beyond conventional biomedical categories and provides a basis for the fundamental reconceptualizations necessary for addressing contemporary developments in psychoneuroimmunology, for example. PMID:2233172

Lyon, M L

1990-08-01

484

76 FR 52347 - Public Land Order No. 7774; Extension of Public Land Order No. 6868; Oregon  

Federal Register 2010, 2011, 2012, 2013

...DEPARTMENT OF THE INTERIOR Bureau of Land Management [LLOR936000-14300000-ET0000; HAG-11-0195; OROR-16124] Public Land Order No. 7774; Extension of Public Land Order No. 6868; Oregon AGENCY: Bureau of...

2011-08-22

485

Approach for Analysis of Order Check Overrides in a Computerized Practitioner Order Entry System  

PubMed Central

SUMMARY While it has been established that computer practitioner order entry systems can prevent transcription errors and check orders for severe drug allergies and interactions[1], continuous monitoring of the effectiveness of order checks is important. The goal of this study is to examine the rate at which high severity order checks generated in the computer practitioner order entry system at VA Puget Sound are overridden by clinicians. We compare our results to those of a previous study[2] that found high override rates for Critical Drug Interaction and Allergy-Drug Interaction order check categories. We are interested in determining whether system changes addressing these high rates have been successful in reducing the overall override rate in these categories. Because the method used previously to extract orders is no longer available, the first step in our study was to develop a new procedure to gather order entry data. This procedure is the subject of our report. PMID:16779320

Lin, Ching-Ping; Nichol, W. Paul; Hoey, Patty; Roth, Terry L.; Anderson, Curtis; Gennari, John H.; Payne, Thomas H.

2005-01-01

486

FERC approves six Order 636 restructurings  

SciTech Connect

The Federal Energy Regulatory Commission (FERC) has approved six Order 636 restructuring orders. The orders are for Southern Natural Gas Co., Gulf States Transmission Corp., Williston Basin Interstate Pipeline Co., Michigan Gas Storage Co., Iroquois Gas Transmission Systems L.P., and Algonquin Gas Transmission Co. The February 10 FERC meeting where the action occurred was the first with Elizabeth Moler sitting as acting chairman. She took the opportunity to issue a dissenting opinion. Her action came during debate over the Iroquois Gas Transmission restructuring and rate design for the Selkirk Cogen Partners, a planned gas-fired cogeneration plant. The proposed order called for using the straight fixed-variable (SFV) rate design for natural gas deliveries to the plant as mandated by Order 636. In a footnote related to the order, the Commission would have allowed a modified fixed-variable (MFV) rate design upon evidence of financial difficulty. Commissioner Martin Allday opposed the footnote allowing the MFV to be used as an exception for a single customer, saying that Order 636 does not allow changes. He reminded his colleagues that consistency in this business is vital. Chairman Moler said she did not believe it would be unduly discriminatory to allow deviation from the SFV method, especially because Iroquois wanted to let other customers use that method. She remarked that MFV rates were critical to development of the Selkirk project, and that the entire project was based on the assumption that the MFV method would be used. She argued that the FERC was sending the wrong signal to the cogeneration and electric communities, and that she regretted the Commissioners were unwilling to offer a glimmer of hope to Selkirk.

Burkhart, L.A.

1993-03-15

487

Dynamical characterization Compactness arguments Approximation of orderings On Conrad's property for group orderings  

E-print Network

Dynamical characterization Compactness arguments Approximation of orderings On Conrad's property Approximation of orderings The word W (f , g) = g-1 fg2 Recall Conrad's theorem: given a finitely generated of orderings The word W (f , g) = g-1 fg2 Recall Conrad's theorem: given a finitely generated group and a C

Harizanov, Valentina S.

488

The First-Order Theory of Ordering Constraints over Feature Trees (Extended Abstract)  

Microsoft Academic Search

The system FT of ordering constraints over feature trees has been introduced as an extension of the system FT of equality constraints over feature trees. We in- vestigate the first-order theory of FT and its fragments in detail, both over finite trees and over possibly infi- nite trees. We prove that the first-order theory of FT is undecidable, in contrast

Martin Muller; Joachim Niehren; Ralf Treinen

489

Cosmological Perturbation Theory Beyond Linear Order  

NASA Astrophysics Data System (ADS)

This thesis presents theoretical studies in cosmology beyond linear order. In the first part of this thesis we discuss various aspects of the higher order corrections to linear theory both in the linear and in the non-linear regime. In Chapter 2 we derive the full set of second-order equations governing the evolution of cosmological perturbations, including the effects of the first-order electron density perturbations, deltae. We provide a detailed analysis of the perturbations to the recombination history of the universe and show that a perturbed version of the Peebles 3-level atom is sufficient for obtaining the evolution of deltae for comoving wavenumbers smaller than 1 Mpc-1. For modes longer than the photon diffusion scale, we find that deltae is enhanced during recombination by a factor of roughly 5 relative to other first-order quantities sourcing the Cosmic Microwave Background (CMB) anisotropies at second order. Using these results, in Chapter 3 we approximately compute the bi