WorldWideScience

Sample records for high spins isomers

  1. High spin isomer beam line at RIKEN

    Energy Technology Data Exchange (ETDEWEB)

    Kishida, T.; Ideguchi, E.; Wu, H.Y. [Institute of Physical and Chemical Research, Saitama (Japan)] [and others

    1996-12-31

    Nuclear high spin states have been the subject of extensive experimental and theoretical studies. For the production of high spin states, fusion reactions are usually used. The orbital angular momentum brought in the reaction is changed into the nuclear spin of the compound nucleus. However, the maximum induced angular momentum is limited in this mechanism by the maximum impact parameter of the fusion reaction and by the competition with fission reactions. It is, therefore, difficult to populate very high spin states, and as a result, large {gamma}-detector arrays have been developed in order to detect subtle signals from such very high spin states. The use of high spin isomers in the fusion reactions can break this limitation because the high spin isomers have their intrinsic angular momentum, which can bring the additional angular momentum without increasing the excitation energy. There are two methods to use the high spin isomers for secondary reactions: the use of the high spin isomers as a target and that as a beam. A high spin isomer target has already been developed and used for several experiments. But this method has an inevitable shortcoming that only {open_quotes}long-lived{close_quotes} isomers can be used for a target: {sup 178}Hf{sup m2} (16{sup +}) with a half-life of 31 years in the present case. By developing a high spin isomer beam, the authors can utilize various short-lived isomers with a short half-life around 1 {mu}s. The high spin isomer beam line of RIKEN Accelerator Facility is a unique apparatus in the world which provides a high spin isomer as a secondary beam. The combination of fusion-evaporation reaction and inverse kinematics are used to produce high spin isomer beams; in particular, the adoption of `inverse kinematics` is essential to use short-lived isomers as a beam.

  2. Island of high-spin isomers near N = 82

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, J.; Back, B.B.; Bernthal, F.M.; Bjornholm, S.; Borggreen, J.; Christensen, O.; Folkmann, F.; Herskind, B.; Khoo, T.L.; Neiman, M.; Puehlhofer, F.; Sletten, G.

    1977-10-17

    Experiments aimed at testing for the existence of yrast traps are reported. A search for delayed ..gamma.. radiation of lifetimes longer than approx. 10 ns and of high multiplicity has been performed by producing more than 100 compound nuclei between Ba and Pb in bombardments with /sup 40/Ar, /sup 50/Ti, and /sup 65/Cu projectiles. An island of high-spin isomers is found to exist in the region 64 < or approx. = Z > or approx. = 71 and N < or approx. = 82.

  3. A new high-spin isomer in {sup 195}Bi

    Energy Technology Data Exchange (ETDEWEB)

    Roy, T.; Mukherjee, G.; Rana, T.K.; Bhattacharya, Soumik; Asgar, Md.A.; Bhattacharya, C.; Bhattacharya, S.; Bhattacharyya, S.; Pai, H. [Variable Energy Cyclotron Centre, Kolkata (India); Madhavan, N.; Bala, I.; Gehlot, J.; Gurjar, R.K.; Jhingan, A.; Kumar, R.; Muralithar, S.; Nath, S.; Singh, R.P.; Varughese, T. [Inter University Acclerator Centre, New Delhi (India); Basu, K.; Bhattacharjee, S.S.; Ghugre, S.S.; Raut, R.; Sinha, A.K. [UGC-DAE-CSR Kolkata Centre, Kolkata (India); Palit, R. [Tata Institute of Fundamental Research, Department of Nuclear and Atomic Physics, Mumbai (India)

    2015-11-15

    A new high-spin isomer has been identified in {sup 195}Bi at the focal plane of the HYbrid Recoil mass Analyser (HYRA) used in the gas-filled mode. The fusion evaporation reactions {sup 169}Tm ({sup 30}Si, x n) {sup 193,} {sup 195}Bi were used with the beam energies on targets of 168 and 146MeV for 6n and 4n channels, respectively. The evaporation residues, separated from the fission fragments, and their decays were detected at the focal plane of HYRA using MWPC, Si-Pad and clover HPGe detectors. The half-life of the new isomer in {sup 195}Bi has been measured to be 1.6(1) μs. The configuration of the new isomer has been proposed and compared with the other isomers in this region. The Total Routhian Surface (TRS) calculations for the three-quasiparticle configurations corresponding to the new isomer suggest an oblate deformation for this isomeric state. The same calculations for different configurations in {sup 195}Bi and for the even-even {sup 194}Pb core indicate that the proton i{sub 13/2} orbital has a large shape driving effect towards oblate shape in these nuclei. (orig.)

  4. A new high-spin isomer in 195Bi

    Science.gov (United States)

    Roy, T.; Mukherjee, G.; Madhavan, N.; Rana, T. K.; Bhattacharya, Soumik; Asgar, Md. A.; Bala, I.; Basu, K.; Bhattacharjee, S. S.; Bhattacharya, C.; Bhattacharya, S.; Bhattacharyya, S.; Gehlot, J.; Ghugre, S. S.; Gurjar, R. K.; Jhingan, A.; Kumar, R.; Muralithar, S.; Nath, S.; Pai, H.; Palit, R.; Raut, R.; Singh, R. P.; Sinha, A. K.; Varughese, T.

    2015-11-01

    A new high-spin isomer has been identified in 195Bi at the focal plane of the HYbrid Recoil mass Analyser (HYRA) used in the gas-filled mode. The fusion evaporation reactions 169Tm (30Si, x n) 193, 195Bi were used with the beam energies on targets of 168 and 146MeV for 6n and 4n channels, respectively. The evaporation residues, separated from the fission fragments, and their decays were detected at the focal plane of HYRA using MWPC, Si-Pad and clover HPGe detectors. The half-life of the new isomer in 195Bi has been measured to be 1.6(1)μs. The configuration of the new isomer has been proposed and compared with the other isomers in this region. The Total Routhian Surface (TRS) calculations for the three-quasiparticle configurations corresponding to the new isomer suggest an oblate deformation for this isomeric state. The same calculations for different configurations in 195Bi and for the even-even 194Pb core indicate that the proton i 13/2 orbital has a large shape driving effect towards oblate shape in these nuclei.

  5. Properties of neutron-rich hafnium high-spin isomers

    CERN Multimedia

    Tungate, G; Walker, P M; Neyens, G; Billowes, J; Flanagan, K; Koester, U H; Litvinov, Y

    It is proposed to study highly-excited multi-quasiparticle isomers in neutron-rich hafnium (Z=72) isotopes. Long half-lives have already been measured for such isomers in the storage ring at GSI, ensuring their accessibility with ISOL production. The present proposal focuses on:\\\\ (i) an on-line experiment to measure isomer properties in $^{183}$Hf and $^{184}$Hf, and\\\\ (ii) an off-line molecular breakup test using REXTRAP, to provide Hf$^{+}$ beams for future laser spectroscopy and greater sensitivity for the future study of more neutron-rich isotopes.

  6. Theoretical studies of possible toroidal high-spin isomers in the light-mass region

    Directory of Open Access Journals (Sweden)

    Staszczak Andrzej

    2016-01-01

    Full Text Available We review our theoretical knowledge of possible toroidal high-spin isomers in the light mass region in 28≤A≤52 obtained previously in cranked Skyrme-Hartree-Fock calculations. We report additional toroidal high-spin isomers in 56Ni with I=114ħ and 140ħ, which follow the same (multi-particle–(multi-hole systematics as other toroidal high-spin isomers. We examine the production of these exotic nuclei by fusion of various projectiles on 20Ne or 28Si as an active target in time-projection-chamber (TPC experiments.

  7. High spin states above the 28{sup {minus}} isomer in {sup 152}Ho

    Energy Technology Data Exchange (ETDEWEB)

    Rizzutto, M.A.; Ribas, R.V.; Cybulska, E.W.; Oliveira, J.R.; Zahn, G.S.; Medina, N.H. [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil); Bazzacco, D.; Medina, N.H.; Brandolini, F.; Burch, R.; Lunardi, S.; Pavan, P.; Alvarez, C.R. [Dipartimento di Fisica and INFN, Sezione di Padova, Padova (Italy); Spolaore, P. [INFN, Laboratori Nazionali di Legnaro (Italy)

    1997-03-01

    The structure of the high spin states above the 28{sup {minus}} isomer in the odd-odd {sup 152}Ho nucleus was investigated using the GASP {gamma}-ray spectrometer coupled to the recoil mass spectrometer CAMEL. The {sup 152}Ho nucleus was populated through the {sup 120}Sn({sup 37}Cl,5n) fusion reaction at a beam energy of 187 MeV. A complex level scheme above that isomer was established up to an excitation energy of 13 MeV and I{approx} 40{h_bar}. No rotational bands were observed. {copyright} {ital 1997} {ital The American Physical Society}

  8. Preequilibrium spin effects in Feshbach-Kerman-Koonin and exciton models and application to high-spin isomer production

    Science.gov (United States)

    Chadwick, M. B.; Young, P. G.; Oblozinsky, P.; Marcinkowski, A.

    1994-06-01

    We describe how the Feshbach-Kerman-Koonin (FKK) theory can be used to obtain residual nucleus spin distributions following preequilibrium decay, by removing the assumption of zero intrinsic spins in multistep direct reactions. By making use of parallels between the exciton model and the FKK multistep direct theory we also obtain a straightforward method for determining spin distributions in the exciton model. We compare these two approaches and apply them to high-spin isomer production cross sections in 14 MeV neutron reactions on hafnium. We obtain reasonable agreement with measurements, though there is evidence that the FKK theory underpredicts high spin transfer reactions. Comparisions with the exciton model suggest that multistep processes in FKK are underestimated, and that an FKK formulation incorporating non-normal DWBA transitions may yield results in closer agreement with the exciton model, and with experiment.

  9. Beta decay of medium and high spin isomers in sup 9 sup 4 Ag

    CERN Document Server

    La Commara, M; Döring, J; Galanopoulos, S; Grawe, H; Harissopoulos, S V; Hellström, M; Janas, Z; Kirchner, R; Mazzocchi, C; Ostrowski, A N; Plettner, C; Rainovski, G; Roeckl, E; Schmidt, K

    2002-01-01

    The very neutron-deficient isotope sup 9 sup 4 Ag was produced at the GSI on-line mass separator by using the reaction sup 5 sup 8 Ni( sup 4 sup 0 Ca, p3n). The beta-decay properties of sup 9 sup 4 Ag were studied by detecting for the first time beta-delayed gamma rays and beta-gamma-gamma coincidences. Both the population of excited levels in the daughter nucleus sup 9 sup 4 Pd and the beta-decay half-life of sup 9 sup 4 Ag were investigated. The major part of the feeding was assigned to the decay of an I suppi=(7 sup +) isomer with a half-life of (0.36+-0.03) s. A weak beta-decay branch was found to populate high-spin levels in the sup 9 sup 4 Pd daughter with I>=18. It is tentatively assigned to the decay of a high-spin parent state in sup 9 sup 4 Ag with I>=17 and a half-life (0.3+-0.2) s. The measured beta-decay properties as well as the level structure of sup 9 sup 4 Ag and sup 9 sup 4 Pd are discussed in comparison with shell-model predictions.

  10. Study of the odd-${A}$, high-spin isomers in neutron-deficient trans-lead nuclei with ISOLTRAP

    CERN Multimedia

    Herfurth, F; Blaum, K; Beck, D; Kowalska, M; Schwarz, S; Stanja, J; Huyse, M L; Wienholtz, F

    We propose to measure the excitation energy of the $\\frac{13^{+}}{2}$ isomers in the neutron-deficient isotopes $^{193,195,197}$Po with the ISOLTRAP mass spectrometer. The assignment of the low- and high-spin isomers will be made by measuring the energy of the $\\alpha$- particles emitted in the decay of purified beams implanted in a windmill system. Using $\\alpha$-decay information, it is then also possible to determine the excitation energy of the similar isomers in the $\\alpha$-daughter nuclei $^{189,191,193}$Pb, $\\alpha$-parent nuclei $^{197,199,201}$Rn, and $\\alpha$-grand-parent nuclei $^{201,203,205}$Ra. The polonium beams are produced with a UC$_{\\textrm{x}}$ target and using the RILIS.

  11. New high spin states and isomers in the {sup 208}Pb and {sup 207}Pb nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Broda, R.; Wrzesinski, J.; Pawlat, T. [and others

    1996-12-31

    The two most prominent examples of the heavy doubly closed shell (DCS) nuclei, {sup 208}Pb and {sup 132}Sn, are not accessible by conventional heavy-ion fusion processes populating high-spin states. This experimental difficulty obscured for a long time the investigation of yrast high-spin states in both DCS and neighboring nuclei and consequently restricted the study of the shell model in its most attractive regions. Recent technical development of multidetector gamma arrays opened new ways to exploit more complex nuclear processes which populate the nuclei of interest with suitable yields for gamma spectroscopy and involve population of moderately high spin states. This new possibility extended the range of accessible spin values and is a promising way to reach new yrast states. Some of these states are expected to be of high configurational purity and can be a source of important shell model parameters which possibly can be used later to check the validity of the spherical shell model description at yet higher spin and higher excitation energy. The nuclei in the closest vicinity of {sup 132}Sn are produced in spontaneous fission and states with spin values up to I=14 can be reached in fission gamma spectroscopy studies with the presently achieved sensitivity of gamma arrays. New results on yrast states in the {sup 134}Te and {sup 135}I nuclei populated in fission of the {sup 248}Cm presented at this conference illustrate such application of the resolving power offered by modern gamma techniques.

  12. Influence of pairing on the ({ital p},{ital t}) transition strength between high-spin {ital K} isomers of Hf isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmenko, N.K. [V. G. Khlopin Radium Institute, 2nd Murinsky Prosp. 28, St. Petersburg 194021 (Russian Federation); Mikhajlov, V.M. [Institute of Physics, St. Petersburg State University, St. Petersburg 19804 (Russian Federation)

    1995-05-01

    The influence of pairing on the probability of the two-nucleon-transfer transition between high-spin {ital K} isomers of Hf isotopes is discussed. Calculations of energies and cross sections are performed by using the particle number projection (FBCS method). In contrast with BCS, the FBCS method predicts that the pairing in many-quasiparticles states does not disappear.

  13. New decay modes of the high-spin isomer of {sup 124}Cs

    Energy Technology Data Exchange (ETDEWEB)

    Radich, A.J.; Garrett, P.E.; Bianco, L.; Bildstein, V.; Chagnon-Lessard, S.; Demand, G.A.; Diaz Varela, A.; Dunlop, R.; Finlay, P.; Hadinia, B.; Jigmeddorj, B.; Laffoley, A.T.; Leach, K.G.; McGee, E.; Michetti-Wilson, J.; Rand, E.T.; Svensson, C.E.; Wong, J. [University of Guelph, Department of Physics, Guelph, ON (Canada); Andreoiu, C.; Cross, D.S.; Starosta, K. [Simon Fraser University, Department of Chemistry, Burnaby, BC (Canada); Ball, G.C.; Garnsworthy, A.B.; Hackman, G.; Rajabali, M.M. [TRIUMF, Vancouver, BC (Canada); Orce, J.N. [TRIUMF, Vancouver, BC (Canada); University of the Western Cape, Department of Physics, Bellville (South Africa); Sumithrarachchi, C.S. [University of Guelph, Department of Physics, Guelph, ON (Canada); Michigan State University, National Superconducting Cyclotron Laboratory, East Lansing, MI (United States); Triambak, S. [TRIUMF, Vancouver, BC (Canada); University of the Western Cape, Department of Physics, Bellville (South Africa); iThemba LABS, Somerset West (South Africa); Wang, Z.M. [Simon Fraser University, Department of Chemistry, Burnaby, BC (Canada); TRIUMF, Vancouver, BC (Canada); Williams, S.J. [TRIUMF, Vancouver, BC (Canada); Michigan State University, National Superconducting Cyclotron Laboratory, East Lansing, MI (United States); Wood, J.L. [Georgia Institute of Technology, School of Physics, Atlanta, GA (United States); Yates, S.W. [University of Kentucky, Departments of Chemistry and Physics and Astronomy, Lexington, KY (United States)

    2017-09-15

    A new β{sup +}/EC branch of 0.11 ± 0.02 % from the (7){sup +} isomer of {sup 124}Cs was identified in a measurement of the decay of {sup 124}Cs using the 8 π spectrometer at TRIUMF. Combinations of γ-γ, γ-e{sup -}, and e{sup -}-e{sup -} coincidence data were used to further investigate the isomeric decay. Six new transitions were observed and their branching ratios were measured. (orig.)

  14. De-excitation of high spin isomers in the sup 1 sup 9 sup 1 Pb isotope

    CERN Document Server

    Lagrange, J M; Dionisio, J S; Vieu, C; Vanhorenbeeck, J

    1999-01-01

    The sup 1 sup 9 sup 1 Pb isotope, produced through different A (b,xn) sup 1 sup 9 sup 1 Pb reactions, where b stands for nuclei such as sup 1 sup 6 O, sup 2 sup 0 Ne, and sup 3 sup 1 P, is studied. The half-life of some excited levels being greater than 10 ns, the recoil catcher method is suitable to look into the de-excitation gamma ray and conversion electron spectra of these states. The conversion coefficients are deduced and e sup - -gamma and gamma-gamma coincidence measurements lead to the part of the level scheme de-exciting these isomers. This level scheme is compared to theoretical predictions obtained through a microscopic calculation in a three quasi-particle approximation, using a surface delta interaction with a reduced pairing component. The conclusions are very similar to those previously obtained for sup 1 sup 9 sup 3 Pb.

  15. General form of intramolecular nuclear spin isomers mixing in C3v -symmetry

    Science.gov (United States)

    Il'ichov, L. V.

    2017-10-01

    Molecules with identical nuclei exist in nature in the form of nuclear spin isomers. In general, spin isomers are not the eigenstates of total molecular Hamiltonian. It also contains parts able to transform spin isomers one into another. Recently, nuclear spin isomers relaxation induced by such a quantum mixing was successfully demonstrated in experiment. That motivates the search for general intramolecular interactions able to mix spin isomers. In the work, the general forms of the possible mixing interactions are found for C3v-type of molecules using generalized Jordan-Schwinger approach to the theory of quantum angular momentum.

  16. Nuclear Spin Isomers: Engineering a Et4 N[DyPc2 ] Spin Qudit.

    Science.gov (United States)

    Moreno-Pineda, Eufemio; Damjanović, Marko; Fuhr, Olaf; Wernsdorfer, Wolfgang; Ruben, Mario

    2017-08-07

    Two dysprosium isotopic isomers were synthesized: Et4 N[163 DyPc2 ] (1) with I=5/2 and Et4 N[164 DyPc2 ] (2) with I=0 (where Pc=phthalocyaninato). Both isotopologues are single-molecule magnets (SMMs); however, their relaxation times as well as their magnetic hystereses differ considerably. Quantum tunneling of the magnetization (QTM) at the energy level crossings is found for both systems via ac-susceptibility and μ-SQUID measurements. μ-SQUID studies of 1(I=5/2) reveal several nuclear-spin-driven QTM events; hence determination of the hyperfine coupling and the nuclear quadrupole splitting is possible. Compound 2(I=0) shows only strongly reduced QTM at zero magnetic field. 1(I=5/2) could be used as a multilevel nuclear spin qubit, namely qudit (d=6), for quantum information processing (QIP) schemes and provides an example of novel coordination-chemistry-discriminating nuclear spin isotopes. Our results show that the nuclear spin of the lanthanide must be included in the design principles of molecular qubits and SMMs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. High-spin structures in Xe132 and Xe133 and evidence for isomers along the N=79 isotones

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, A.; Siciliano, M.; Birkenbach, B.; Reiter, P.; Hadyńska-Klęk, K.; Wheldon, C.; Valiente-Dobón, J. J.; Teruya, E.; Yoshinaga, N.; Arnswald, K.; Bazzacco, D.; Blazhev, A.; Bracco, A.; Bruyneel, B.; Chakrawarthy, R. S.; Chapman, R.; Cline, D.; Corradi, L.; Crespi, F. C. L.; Cromaz, M.; de Angelis, G.; Eberth, J.; Fallon, P.; Farnea, E.; Fioretto, E.; Fransen, C.; Freeman, S. J.; Fu, B.; Gadea, A.; Gelletly, W.; Giaz, A.; Görgen, A.; Gottardo, A.; Hayes, A. B.; Hess, H.; Hetzenegger, R.; Hirsch, R.; Hua, H.; John, P. R.; Jolie, J.; Jungclaus, A.; Karayonchev, V.; Kaya, L.; Korten, W.; Lee, I. Y.; Leoni, S.; Liang, X.; Lunardi, S.; Macchiavelli, A. O.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Mijatović, T.; Montagnoli, G.; Montanari, D.; Müller-Gatermann, C.; Napoli, D.; Pearson, C. J.; Podolyák, Zs.; Pollarolo, G.; Pullia, A.; Queiser, M.; Recchia, F.; Regan, P. H.; Régis, J. -M.; Saed-Samii, N.; Şahin, E.; Scarlassara, F.; Seidlitz, M.; Siebeck, B.; Sletten, G.; Smith, J. F.; Söderström, P. -A.; Stefanini, A. M.; Stezowski, O.; Szilner, S.; Szpak, B.; Teng, R.; Ur, C.; Warner, D. D.; Wolf, K.; Wu, C. Y.; Zell, K. O.

    2017-08-01

    The transitional nuclei 132 Xe and 133 Xe are investigated after multinucleon-transfer (MNT) and fusion-evaporation reactions. Both nuclei are populated (i) in 136 Xe + 208 Pb MNT reactions employing the high-resolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA, (ii) in the 136 Xe + 198 Pt MNT reaction employing the GAMMASPHERE spectrometer in combination with the gas-detector array CHICO, and (iii) as an evaporation residue after a 130 Te ( α , x n ) 134 - x n Xe fusion-evaporation reaction employing the HORUS γ -ray array at the University of Cologne. The high-spin level schemes are considerably extended above the J π = ( 7 - ) and ( 10 + ) isomers in 132 Xe and above the 11 / 2 - isomer in 133 Xe . The results are compared to the high-spin systematics of the Z = 54 as well as the N = 78 and N = 79 chains. Furthermore, evidence is found for a long-lived ( T 1 / 2 >> 1 μ s ) isomer in 133 Xe which closes a gap along the N = 79 isotones. Shell-model calculations employing the SN100PN and PQM130 effective interactions reproduce the experimental findings and provide guidance to the interpretation of the observed high-spin features.

  18. Production of isomers by neutron-induced inelastic scattering on 193Ir and influence of spin distribution in the pre-equilibrium process

    Science.gov (United States)

    Kawano, Toshihiko; Talou, Patrick; Chadwick, Mark B.

    2006-06-01

    We present calculations of the production cross-section of isomeric-state for 193Ir. The isomer was produced by neutron inelastic scattering, and several γ-ray production cross-sections were measured at LANSCE with the GEANIE detector. The total isomer production cross-section is then inferred by combining the experimental data with the GNASH statistical model calculations. The spin distribution is calculated with the Feshbach-Kerman-Koonin (FKK) quantum mechanical pre-equilibrium theory, and it is incorporated with the GNASH results. We found that the inclusion of FKK has a significant impact on the isomer production cross-sections at high energies.

  19. Production of isomers by neutron-induced inelastic scattering on {sup 193}Ir and influence of spin distribution in the pre-equilibrium process

    Energy Technology Data Exchange (ETDEWEB)

    Kawano, Toshihiko [Los Alamos National Laboratory, NM 87545 (United States)]. E-mail: kawano@lanl.gov; Talou, Patrick [Los Alamos National Laboratory, NM 87545 (United States); Chadwick, Mark B. [Los Alamos National Laboratory, NM 87545 (United States)

    2006-06-23

    We present calculations of the production cross-section of isomeric-state for {sup 193}Ir. The isomer was produced by neutron inelastic scattering, and several {gamma}-ray production cross-sections were measured at LANSCE with the GEANIE detector. The total isomer production cross-section is then inferred by combining the experimental data with the GNASH statistical model calculations. The spin distribution is calculated with the Feshbach-Kerman-Koonin (FKK) quantum mechanical pre-equilibrium theory, and it is incorporated with the GNASH results. We found that the inclusion of FKK has a significant impact on the isomer production cross-sections at high energies.

  20. Discrimination of nuclear spin isomers exploiting the excited state dynamics of a quinodimethane derivative

    Energy Technology Data Exchange (ETDEWEB)

    Obaid, Rana [Institut für Theoretische Chemie, Universität Wien, Währinger Str. 17, 1090 Wien (Austria); Faculty of Pharmacy, Al-Quds University, Abu Dis, Palestine (Country Unknown); Kinzel, Daniel; Oppel, Markus, E-mail: markus.oppel@univie.ac.at; González, Leticia [Institut für Theoretische Chemie, Universität Wien, Währinger Str. 17, 1090 Wien (Austria)

    2014-10-28

    Despite the concept of nuclear spin isomers (NSIs) exists since the early days of quantum mechanics, only few approaches have been suggested to separate different NSIs. Here, a method is proposed to discriminate different NSIs of a quinodimethane derivative using its electronic excited state dynamics. After electronic excitation by a laser field with femtosecond time duration, a difference in the behavior of several quantum mechanical operators can be observed. A pump-probe experimental approach for separating these different NSIs is then proposed.

  1. Pulse-fluence-specified optimal control simulation with applications to molecular orientation and spin-isomer-selective molecular alignment

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Masataka; Nakashima, Kaoru; Ohtsuki, Yukiyoshi [Department of Chemistry, Graduate School of Science, Tohoku University 6-3 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8578 (Japan)

    2015-12-31

    We propose an optimal control simulation with specified pulse fluence and amplitude. The simulation is applied to the orientation control of CO molecules to examine the optimal combination of THz and laser pulses, and to discriminate nuclear-spin isomers of {sup 14}N{sub 2} as spatially anisotropic distributions.

  2. High spin states in Cu

    Indian Academy of Sciences (India)

    up of high-spin configurations outlined above, a detailed and careful study of the medium spin, near yrast states in this nucleus is important for reliable assignments of spins and parities to states in superdeformed bands [1,6] in mass region 60. Also, the observation of direct proton decay from excited states in Cu nuclei [14] ...

  3. The role of core excitations in the structure and decay of the 16+ spin-gap isomer in 96Cd

    Directory of Open Access Journals (Sweden)

    P.J. Davies

    2017-04-01

    Full Text Available The first evidence for β-delayed proton emission from the 16+ spin gap isomer in 96Cd is presented. The data were obtained from the Rare Isotope Beam Factory, at the RIKEN Nishina Center, using the BigRIPS spectrometer and the EURICA decay station. βp branching ratios for the ground state and 16+ isomer have been extracted along with more precise lifetimes for these states and the lifetime for the ground state decay of 95Cd. Large scale shell model (LSSM calculations have been performed and WKB estimates made for ℓ=0,2,4 proton emission from three resonance-like states in 96Ag, that are populated by the β decay of the isomer, and the results compared to the new data. The calculations suggest that ℓ=2 proton emission from the resonance states, which reside ∼5 MeV above the proton separation energy, dominates the proton decay. The results highlight the importance of core-excited wavefunction components for the 16+ state.

  4. Non-collective high-spin states in /sup 148/Dy

    Energy Technology Data Exchange (ETDEWEB)

    Dines, E.L.

    1985-04-01

    General physical concepts regarding nuclear high-spin states are given. The high-spin states in /sup 148/Dy(Z = 66, N = 82) were produced via the reaction /sup 112/Cd(Pb-backed)(/sup 40/Ar,4n) at E/sub lab/ = 175, at the 88-inch Cyclotron at Lawrence Berkeley Laboratory. Methods for placing gates on various transitions above and below the 480 nsec isomer at 10/sup +/(known from previous work), as well as for calculating transition intensities and their associated errors, are given. Calculations of angular correlations for multiple ..gamma..-ray cascades, assuming non-zero-width distributions in m-states for some given spin state, were done and compared to experimental values. Analysis of RF - Ge and Ge - Ge TAC spectra for transitions above the 480 nsec isomer implied lifetimes of less than or equal to 5 nsec (except for the 327.2 keV transition). Using such analysis, some 19 new ..gamma..-ray transitions were discovered above the isomer, thereby extending the /sup 148/Dy level scheme up to spin I = 31 h-bar. Assignments of spins and parities for the new levels are made based on information obtained from angular correlations and the lifetime limits. Previous work on the 11 transitions below the 480 nsec isomer is confirmed.

  5. High-spin nuclear spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Diamond, R.M.

    1986-07-01

    High-spin spectroscopy is the study of the changes in nuclear structure, properties, and behavior with increasing angular momentum. It involves the complex interplay between collective and single-particle motion, between shape and deformation changes, particle alignments, and changes in the pairing correlations. A review of progress in theory, experimentation, and instrumentation in this field is given. (DWL)

  6. Spins and magnetic moments of 58;60;62;64Mn ground states and isomers

    CERN Document Server

    Heylen, H; Billowes, J; Bissell, M L; Blaum, K; Campbell, P; Cheal, B; Ruiz, R F Garcia; Geppert, Ch; Gins, W; Kowalska, M; Kreim, K; Lenzi, S M; Moore, I D; Neugart, R; Neyens, G; Nörtershäuser, W; Papuga, J; Yordanov, D T

    2015-01-01

    The odd-odd 54;56;58;60;62;64Mn isotopes (Z = 25) were studied using bunched-beam collinear laser spectroscopy at ISOLDE, CERN. From the measured hyperfine spectra the spins and magnetic moments of Mn isotopes up to N = 39 were extracted. The previous tentative ground state spin assignments of 58;60;62;64Mn are now firmly determined to be I = 1 along with an I = 4 assignment for the isomeric states in 58;60;62Mn. The I = 1 magnetic moments show a decreasing trend with increasing neutron number while the I = 4 moments remain quite constant between N = 33 and N = 37. The results are compared to large-scale shell-model calculations using the GXPF1A and LNPS effective interactions. The excellent agreement of the ground state moments with the predictions from the LNPS calculations illustrates the need for an increasing amount of proton excitations across Z = 28 and neutron excitations across N = 40 in the ground state wave functions from N = 37 onwards.

  7. High-field spin dynamics of antiferromagnetic quantum spin chains

    DEFF Research Database (Denmark)

    Enderle, M.; Regnault, L.P.; Broholm, C.

    2000-01-01

    The characteristic internal order of macroscopic quantum ground states in one-dimensional spin systems is usually not directly accessible, but reflected in the spin dynamics and the field dependence of the magnetic excitations. In high magnetic fields quantum phase transitions are expected. We...... present recent work on the high-field spin dynamics of the S = I antiferromagnetic Heisenberg chains NENP (Haldane ground state) and CsNiCl3 (quasi-1D HAF close to the quantum critical point), the uniform S = 1/2 chain CTS, and the spin-Peierls system CuGeO3. (C) 2000 Elsevier Science B,V. All rights...

  8. A high-temperature quantum spin liquid with polaron spins

    Science.gov (United States)

    Klanjšek, Martin; Zorko, Andrej; Žitko, Rok; Mravlje, Jernej; Jagličić, Zvonko; Biswas, Pabitra Kumar; Prelovšek, Peter; Mihailovic, Dragan; Arčon, Denis

    2017-11-01

    The existence of a quantum spin liquid (QSL) in which quantum fluctuations of spins are sufficiently strong to preclude spin ordering down to zero temperature was originally proposed theoretically more than 40 years ago, but its experimental realization turned out to be very elusive. Here we report on an almost ideal spin liquid state that appears to be realized by atomic-cluster spins on the triangular lattice of a charge-density wave state of 1T-TaS2. In this system, the charge excitations have a well-defined gap of ~0.3 eV, while nuclear quadrupole resonance and muon-spin-relaxation experiments reveal that the spins show gapless QSL dynamics and no long-range magnetic order at least down to 70 mK. Canonical T2 power-law temperature dependence of the spin relaxation dynamics characteristic of a QSL is observed from 200 K to Tf = 55 K. Below this temperature, we observe a new gapless state with reduced density of spin excitations and high degree of local disorder signifying new quantum spin order emerging from the QSL.

  9. High-K isomers in transactinide nuclei close to N = 162

    Energy Technology Data Exchange (ETDEWEB)

    Prassa, V., E-mail: vprassa@phy.hr; Nikšić, T.; Vretenar, D. [Physics Department, Faculty of science, University of Zagreb, 10000 Zagreb (Croatia); Lu, Bing-Nan [Institut fur Kernphysik, Institute for Advanced Simulation, and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); Ackermann, D. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt (Germany)

    2015-10-15

    Transactinide nuclei around neutron number N = 162 display axially deformed equilibrium shapes, as shown in our previous analysis [1] of constrained mean-field energy surfaces and collective excitation spectra. In the present study we are particularly interested in the occurrence of high-K isomers in the axially deformed isotopes of Rf (Z = 104), Sg (Z = 106), Hs (Z = 108), and Ds (Z = 110), with neutron number N = 160 − 166 and the effect of the N=162 closure on the structure and distribution of two-quasiparticle (2qp) states. The evolution of high-K isomers is analysed in a self-consistent axially-symmetric relativistic Hartree-Bogoliubov calculation using the blocking approximation with time-reversal symmetry breaking.

  10. g Factor of the 7{sup -} isomer in {sup 126}Sn and first observation of spin-alignment in relativistic fission

    Energy Technology Data Exchange (ETDEWEB)

    Ilie, G., E-mail: gabriela.ilie@yale.ed [IKP, Universitaet zu Koeln, 50937 Koeln (Germany); National Institute for Physics and Nuclear Engineering, 76900 Bucharest (Romania); Neyens, G. [Instituut voor Kern- en Stralingsfysica, K.U. Leuven, 3001 Leuven (Belgium); Simpson, G.S. [ILL, 38042 Grenoble Cedex (France); LPSC, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, INPG, 38026 Grenoble Cedex (France); Jolie, J.; Blazhev, A. [IKP, Universitaet zu Koeln, 50937 Koeln (Germany); Grawe, H. [GSI, 64291 Darmstadt (Germany); Lozeva, R.L. [Instituut voor Kern- en Stralingsfysica, K.U. Leuven, 3001 Leuven (Belgium); Faculty of Physics, University of Sofia ' St. Kl. Ohridski' , 1164 Sofia (Bulgaria); Vermeulen, N. [Instituut voor Kern- en Stralingsfysica, K.U. Leuven, 3001 Leuven (Belgium); Atanasova, L. [Faculty of Physics, University of Sofia ' St. Kl. Ohridski' , 1164 Sofia (Bulgaria); Balabanski, D.L. [Dipartimento di Fisica, Universita di Camerino, 62032 Camerino (Italy); INRNE, Bulgarian Academy of Sciences, 1784 Sofia (Bulgaria); Becker, F. [GSI, 64291 Darmstadt (Germany); Bednarczyk, P. [GSI, 64291 Darmstadt (Germany); The Henryk Niewodniczanski Institute of Nuclear Physics, PAN, 31342 Krakow (Poland); Brandau, C. [GSI, 64291 Darmstadt (Germany); Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Caceres, L. [GSI, 64291 Darmstadt (Germany); Departamento de Fisica Teorica, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Chamoli, S.K. [Department of Particle Physics, Weizmann Institute of Science, 76100 Rehovot (Israel); Daugas, J.M. [CEA, DAM, DIF, 91297 Arpajon Cedex (France); Doornenbal, P.; Gerl, J.; Gorska, M. [GSI, 64291 Darmstadt (Germany); Grebosz, J. [GSI, 64291 Darmstadt (Germany); The Henryk Niewodniczanski Institute of Nuclear Physics, PAN, 31342 Krakow (Poland)

    2010-04-19

    We report on the g factor measurement of the isomeric 7{sup -} state (E{sup *}=2219 keV, T{sub 1/2}=5.9(8) mus) in the neutron-rich {sup 126}Sn nucleus. The nucleus was produced by the fission of a relativistic {sup 238}U beam and reaction products were selected by the FRS fragment separator at GSI. For the first time, spin-alignment was observed after relativistic fission. It was used to deduce the g factor of the 7{sup -} isomeric state, g(7{sup -})=-0.098(9), from the measured perturbed angular distribution of its gamma decay using the RISING Cluster detectors. The observed value confirms the suggested nu(h{sub 11/2}{sup -1}d{sub 3/2}{sup -1}) dominant configuration, which has been proposed for the 7{sup -} isomers in neutron-rich Sn isotopes. The failure of the g factor additivity rule and the importance of core polarization evolution with increasing distance from the doubly-magic {sup 132}Sn is discussed. The first observation of 18(8)% of spin-alignment produced by the relativistic fission of a {sup 238}U beam paves the way to study moments of neutron-rich (sub-)microsecond isomers, which are difficult to align by other means.

  11. High-spin yrast structure of {sup 43}Sc

    Energy Technology Data Exchange (ETDEWEB)

    Morikawa, T [Department of Physics, Kyushu University, Hakozaki, Fukuoka 812-8581 (Japan); Nakamura, M [Department of Physics, Kyushu University, Hakozaki, Fukuoka 812-8581 (Japan); Sugimitsu, T [Department of Physics, Kyushu University, Hakozaki, Fukuoka 812-8581 (Japan); Kusakari, H [Faculty of Education, Chiba University, Chiba 263-8522 (Japan); Oshima, M [Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Toh, Y [Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Koizumi, M [Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Kimura, A [Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Goto, J [Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Hatsukawa, Y [Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195 (Japan); Sugawara, M [Chiba Institute of Technology, Narashino, Chiba 275-0023 (Japan)

    2005-01-01

    High-spin yrast states in {sup 43}Sc were investigated by using in-beam {gamma}-ray technique with the {sup 27}Al({sup 19}F,p2n) reaction at 50 MeV. The positive-parity rotational band built on the 152-keV J{sup {pi}} = 3/2{sup +} state has been extended up to the terminating J{sup {pi}} = (27/2{sup +}) state. Several fast transitions feeding to the oblate-deformed J{sup {pi}} = 19/2{sup -} isomer have been also identified. the character of the observed levels and transition rates were discussed in comparison with the shell-model calculations.

  12. High spin properties of Ba

    Indian Academy of Sciences (India)

    Abstract. The 124Ba nucleus is investigated on the basis of the method of statistical mechanics by assuming the nucleons to move in triaxially deformed Nilsson potential. The variation in the Fermi energies of protons and neutrons is studied as a function of spin and temperature. The Fermi energies determined as a function ...

  13. g-factors of isomers around N approx 40, Z approx 28 from time-dependent Larmor precession on spin-aligned projectile-like fragments

    CERN Document Server

    Neyens, G; Grzywacz, R; Hass, M; De Oliveira-Santos, F; Lewitowicz, M; Balabanski, D L; Bingham, C; Borcea, C; Coulier, N; Coussement, R; Daugas, J M; De France, G; Goldring, G; aGórska, M; Grawe, H; Oleari, C; Macovei, I; Mach, H; Page, R; Pfützner, M; Penionzhkevich, Yu E; Podolyák, Z; Regan, P H; Rykaczewski, K; Sawicka, M; Smirnova, N A; Sobolev, Y; Teughels, S; Vyvey, K

    2002-01-01

    First and preliminary results of an experiment aimed at measuring g-factors of isomeric states in neutron-rich nuclei in the vicinity of sup 6 sup 8 Ni are reported. Isomers near the predicted N=40 sub-shell closure in sup 6 sup 9 Cu, sup 6 sup 7 Ni and sup 6 sup 6 Co have been populated in the fragmentation of a sup 7 sup 6 Ge, 61.4 MeV/u beam onto a 145 mg/cm sup 2 sup 9 Be target at GANIL. Here we report the results for the 357(2) ns, I suppi=13/2 sup + isomer in sup 6 sup 9 Cu for which a preliminary gyromagnetic ratio of |g|=0.195(9) was derived. The Larmor precession of the spin-oriented isomeric ensemble was measured by recording gamma-ion correlations in a 20 mu s time window. This pioneering experiment has indicated interesting nuclear structure information and shows promising possibilities for future studies of this kind.

  14. Spin-alignment and g-factor measurement of the I{sup {pi}}=12{sup +} isomer in {sup 192}Pb produced in the relativistic-energy fragmentation of a {sup 238}U beam

    Energy Technology Data Exchange (ETDEWEB)

    Kmiecik, M.; Maj, A.; Ciemala, M.; Grebosz, J.; Lach, M.; Maier, K.H.; Mazurek, K.; Meczynski, W.; Myalski, S.; Styczen, J.; Zieblinski, M. [H. Niewodniczanski Inst. of Nuclear Physics PAN, Krakow (Poland); Gerl, J.; Becker, F.; Caceres, L.; Doornenbal, P.; Gorska, M.; Grawe, H.; Kojuharov, I.; Prokopowicz, W.; Saito, N.; Saito, T.R.; Wollersheim, H.J. [GSI, Darmstadt (Germany); Neyens, G.; Mallion, S.; Vermeulen, N. [Inst. voor Kern- en Stralingsfysica, K.U. Leuven (Belgium); Atanasova, L.; Detistov, P. [Univ. of Sofia ' St. Kl. Ohridski' (Bulgaria). Faculty of Physics; Balabanski, D.L. [Univ. degli Studi di Camerino (Italy); INFN sez. Perugia, Dipt. di Fisica, Camerino (Italy); Bulgarian Academy of Sciences, Inst. for Nuclear Research and Nuclear Energy, Sofia (Bulgaria); Bednarczyk, P. [H. Niewodniczanski Inst. of Nuclear Physics PAN, Krakow (Poland); GSI, Darmstadt (Germany); Benzoni, G.; Blasi, N.; Brambilla, S.; Million, B.; Wieland, O. [INFN Sez. di Milano (Italy); Bracco, A.; Camera, F.; Crespi, F.C.L.; Leoni, S.; Montanari, D. [INFN Sez. di Milano (Italy); Univ. degli Studi di Milano (Italy); Chamoli, S.K.; Hass, M.; Lakshmi, S. [Weizman Inst. of Science, Rehovot (Israel); Chmel, S. [Fraunhofer INT, Euskirchen (Germany); Daugas, J.M. [CEA, DAM, DIF, Arpajon Cedex (France); Georgiev, G. [Univ. Paris-Sud 11, CNRS/IN2P3, CSNSM, Orsay-Campus (France); Gladnishki, K. [Univ. of Sofia ' St. Kl. Ohridski' (Bulgaria). Faculty of Physics; Univ. degli Studi di Camerino (Italy); INFN sez. Perugia, Dipt. di Fisica, Camerino (Italy); Hoischen, R.; Rudolph, D. [Lund Univ., Dept. of Physics, Lund (Sweden); Ilie, G. [Univ. zu Koeln, Inst. fuer Kernphysik, Koeln (Germany); National Inst. for Physics and Nuclear Engineering, Bucharest (Romania); Ionescu-Bujor, M. [National Inst. for Physics and Nuclear Engineering, Bucharest (Romania); Jolie, J. [Univ. zu Koeln, Institut fuer Kernphysik, Koeln (Germany)] [and others

    2010-08-15

    The feasibility of measuring g -factors using the TDPAD method applied to high-energy, heavy fragmentation products is explored. The 2623keV I{sup {pi}}=12{sup +} isomer in {sup 192}Pb with {tau}=1.57{mu}s has been produced using the fragmentation of a 1A GeV {sup 238}U beam. The results presented demonstrate for the first time that such heavy nuclei produced in a fragmentation reaction with a relativistic beam are sufficiently well spin-aligned. Moreover, the rather large value of the alignment, 28(10)% of the maximum possible, is preserved during the separation process allowing the determination of magnetic moments. The measured values of the lifetime, {tau}=1.54(9) {mu}s, and the g-factor, g=-0.175(20), agree with the results of previous investigations using fusion-evaporation reactions. (orig.)

  15. Resolution of triacylglycerol positional isomers by reversed-phase high-performance liquid chromatography.

    Science.gov (United States)

    Momchilova, Svetlana; Tsuji, Koichiro; Itabashi, Yutaka; Nikolova-Damyanova, Boryana; Kuksis, Arnis

    2004-08-01

    The ability of reversed-phase high-performance liquid chromatography (RP-HPLC) to separate some positionally isomeric disaturated and monounsaturated triacylglycerols (TAGs) as intact species is demonstrated for the first time. Mobile phases of acetonitrile modified with methanol, ethanol, 2-propanol, 1-propanol, 1-butanol, acetone, or dichloromethane were tested for the separation of POP-PPO, PLP-PPL, PEP-PPE, and PDP-PPD (P-palmitic, O-oleic, L-linoleic, E-eicosapentaenoic, D-docosahexaenoic acid residue) on a single RP-HPLC column. The resolution improved with increasing number of double bonds in the acyl residues. While POP and PPO were only partially resolved, PDP and PPD were fully separated with all tested mobile phases, except those containing methanol. Also separated were the four TAGs having the same equivalent carbon number (ECN = 42), PEP, PPE, PDP, and PPD, on a single RP-HPLC column with mobile phase acetonitrile-2-propanol (70:30, v/v) at 0.8 mL/min. In all cases the isomer with the unsaturated acyl residue in either 1- or 3-position was retained more strongly than the respective 2-isomer.

  16. High-K isomers as probes of octupole collectivity in heavy nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Walker, P.M., E-mail: p.walker@surrey.ac.u [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Minkov, N. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Institute of Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, BG-1784 Sofia (Bulgaria)

    2010-11-01

    The influence of the octupole deformation on the structure of high-K isomeric states in the region of heavy even-even actinide nuclei is studied through a reflection asymmetric deformed shell model (DSM). Two-quasiparticle states with high-K values are constructed by taking into account the pairing effect through a DSM + BCS procedure with constant pairing interaction. The behaviour of two-quasiparticle energies and magnetic dipole moments of K{sup {pi}=}6{sup +}, 6{sup -} and 8{sup -} configurations, applicable to mass numbers in the range A=234-252, was examined over a wide range of quadrupole and octupole deformations. A pronounced sensitivity of the magnetic moments to the octupole deformation is found. The result suggests a possibly important role for high-K isomers in determining the degree of octupole deformation in heavy actinide nuclei.

  17. High-Spin Cobalt Hydrides for Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Holland, Patrick L. [Univ. of Rochester, NY (United States)

    2013-08-29

    Organometallic chemists have traditionally used catalysts with strong-field ligands that give low-spin complexes. However, complexes with a weak ligand field have weaker bonds and lower barriers to geometric changes, suggesting that they may lead to more rapid catalytic reactions. Developing our understanding of high-spin complexes requires the use of a broader range of spectroscopic techniques, but has the promise of changing the mechanism and/or selectivity of known catalytic reactions. These changes may enable the more efficient utilization of chemical resources. A special advantage of cobalt and iron catalysts is that the metals are more abundant and cheaper than those currently used for major industrial processes that convert unsaturated organic molecules and biofeedstocks into useful chemicals. This project specifically evaluated the potential of high-spin cobalt complexes for small-molecule reactions for bond rearrangement and cleavage reactions relevant to hydrocarbon transformations. We have learned that many of these reactions proceed through crossing to different spin states: for example, high-spin complexes can flip one electron spin to access a lower-energy reaction pathway for beta-hydride elimination. This reaction enables new, selective olefin isomerization catalysis. The high-spin cobalt complexes also cleave the C-O bond of CO2 and the C-F bonds of fluoroarenes. In each case, the detailed mechanism of the reaction has been determined. Importantly, we have discovered that the cobalt catalysts described here give distinctive selectivities that are better than known catalysts. These selectivities come from a synergy between supporting ligand design and electronic control of the spin-state crossing in the reactions.

  18. Atlas of Nuclear Isomers

    Science.gov (United States)

    Jain, Ashok Kumar; Maheshwari, Bhoomika; Garg, Swati; Patial, Monika; Singh, Balraj

    2015-09-01

    We present an atlas of nuclear isomers containing the experimental data for the isomers with a half-life ≥ 10 ns together with their various properties such as excitation-energy, half-life, decay mode(s), spin-parity, energies and multipolarities of emitted gamma transitions, etc. The ENSDF database complemented by the XUNDL database has been extensively used in extracting the relevant data. Recent literature from primary nuclear physics journals, and the NSR bibliographic database have been searched to ensure that the compiled data Table is as complete and current as possible. The data from NUBASE-12 have also been checked for completeness, but as far as possible original references have been cited. Many interesting systematic features of nuclear isomers emerge, some of them new; these are discussed and presented in various graphs and figures. The cutoff date for the extraction of data from the literature is August 15, 2015.

  19. Atlas of Nuclear Isomers

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Ashok Kumar, E-mail: ajainfph@iitr.ac.in [Department of Physics, Indian Institute of Technology, Roorkee-247667 (India); Maheshwari, Bhoomika; Garg, Swati; Patial, Monika [Department of Physics, Indian Institute of Technology, Roorkee-247667 (India); Singh, Balraj [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario-L8S 4M1 (Canada)

    2015-09-15

    We present an atlas of nuclear isomers containing the experimental data for the isomers with a half-life ≥ 10 ns together with their various properties such as excitation-energy, half-life, decay mode(s), spin-parity, energies and multipolarities of emitted gamma transitions, etc. The ENSDF database complemented by the XUNDL database has been extensively used in extracting the relevant data. Recent literature from primary nuclear physics journals, and the NSR bibliographic database have been searched to ensure that the compiled data Table is as complete and current as possible. The data from NUBASE-12 have also been checked for completeness, but as far as possible original references have been cited. Many interesting systematic features of nuclear isomers emerge, some of them new; these are discussed and presented in various graphs and figures. The cutoff date for the extraction of data from the literature is August 15, 2015.

  20. Spinnability Investigation of High Strength Steel in Draw-spinning and Flow-spinning

    Science.gov (United States)

    Shi, L.; Xiao, H.; Xu, D. K.

    2017-09-01

    High strength steels are difficult to process in spinning due to their high yield and tensile strength, poor ductility and large springback. In this paper, formability of dual phase steel has been investigated on the basis of spinnability evaluation in draw-spinning and flow-spinning processes. The influences of key process parameters such as feed ratio and wheel fillet radius on forming limit coefficient in draw-spinning and maximum thinning ratio in flow-spinning are studied in detail.

  1. Spin structure in high energy processes

    Science.gov (United States)

    Deporcel, L.; Dunwoodie, C.

    1994-12-01

    This report contains papers of the following topics: Spin, Mass, and Symmetry; physics with polarized Z(sup 0)s; spin and precision electroweak physics; polarized electron sources; polarization phenomena in quantum chromodynamics; polarized lepton-nucleon scattering; polarized targets in high energy physics; spin dynamics in storage rings and linear accelerators; spin formalism and applications to new physics searches; precision electroweak physics at LEP; recent results on heavy flavor physics from LEP experiments using 1990--1992 data; precise measurement of the left-right cross section asymmetry in Z boson production by electron-positron collisions; preliminary results on heavy flavor physics at SLD; QCD tests with SLD and polarized beams; recent results from TRISTAN at KEK; recent B physics results from CLEO; searching for the H dibaryon at Brookhaven; recent results from the compton observatory; the spin structure of the deuteron; spin structure of the neutron ((sup 3)HE) and the Bjoerken sum rule; a consumer's guide to lattice QCD results; top ten models constrained by b yields sy; a review of the Fermilab fixed target program; results from the D0 experiment; results from CDF at FNAL; quantum-mechanical suppression of bremsstrahlung; report from the ZEUS collaboration at HERA; physics from the first year of H1 at HERA, and hard diffraction. These papers have been cataloged separately elsewhere.

  2. Spin structure in high energy processes: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    DePorcel, L.; Dunwoodie, C. [eds.

    1994-12-01

    This report contains papers as the following topics: Spin, Mass, and Symmetry; physics with polarized Z{sup 0}s; spin and precision electroweak physics; polarized electron sources; polarization phenomena in quantum chromodynamics; polarized lepton-nucleon scattering; polarized targets in high energy physics; spin dynamics in storage rings and linear accelerators; spin formalism and applications to new physics searches; precision electroweak physics at LEP; recent results on heavy flavor physics from LEP experiments using 1990--1992 data; precise measurement of the left-right cross section asymmetry in Z boson production by electron-positron collisions; preliminary results on heavy flavor physics at SLD; QCD tests with SLD and polarized beams; recent results from TRISTAN at KEK; recent B physics results from CLEO; searching for the H dibaryon at Brookhaven; recent results from the compton observatory; the spin structure of the deuteron; spin structure of the neutron ({sup 3}HE) and the Bjoerken sum rule; a consumer`s guide to lattice QCD results; top ten models constrained by b {yields} sy; a review of the Fermilab fixed target program; results from the D0 experiment; results from CDF at FNAL; quantum-mechanical suppression of bremsstrahlung; report from the ZEUS collaboration at HERA; physics from the first year of H1 at HERA, and hard diffraction. These papers have been cataloged separately elsewhere.

  3. Separation of Opiate Isomers Using Electrospray Ionization and Paper Spray Coupled to High-Field Asymmetric Waveform Ion Mobility Spectrometry

    Science.gov (United States)

    Manicke, Nicholas E.; Belford, Michael

    2015-05-01

    One limitation in the growing field of ambient or direct analysis methods is reduced selectivity caused by the elimination of chromatographic separations prior to mass spectrometric analysis. We explored the use of high-field asymmetric waveform ion mobility spectrometry (FAIMS), an ambient pressure ion mobility technique, to separate the closely related opiate isomers of morphine, hydromorphone, and norcodeine. These isomers cannot be distinguished by tandem mass spectrometry. Separation prior to MS analysis is, therefore, required to distinguish these compounds, which are important in clinical chemistry and toxicology. FAIMS was coupled to a triple quadrupole mass spectrometer, and ionization was performed using either a pneumatically assisted heated electrospray ionization source (H-ESI) or paper spray, a direct analysis method that has been applied to the direct analysis of dried blood spots and other complex samples. We found that FAIMS was capable of separating the three opiate structural isomers using both H-ESI and paper spray as the ionization source.

  4. Decays of the Y-97 isomers to the single neutron nucleus Zr-97

    NARCIS (Netherlands)

    Lhersonneau, G; Dendooven, P; Hankonen, S; Honkanen, A; Huhta, M; Julin, R; Juutinen, S; Oinonen, M; Penttila, H; Savelius, A; Tormanen, S; Aysto, J; Butler, PA; Cocks, JFC; Jones, PM; Smith, JF

    The decays of the 9/2(+) and of the three-quasiparticle high spin isomer in Y-97 have been investigated following on-line mass separation with the ion-guide technique. Spins and parities for several of the lowest-lying levels in the daughter nucleus Zr-97 are revised and configurations are proposed.

  5. High resolution spin- and angle-resolved photoelectron spectroscopy for 3D spin vectorial analysis

    Science.gov (United States)

    Okuda, Taichi; Miyamoto, Koji; Kimura, Akio; Namatame, Hirofumi; Taniguchi, Masaki

    2013-03-01

    Spin- and angle-resolved photoelectron spectroscopy (SARPES) is the excellent tool which can directly observe the band structure of crystals with separating spin-up and -down states. Recent findings of new class of materials possessing strong spin orbit interaction such as Rashba spin splitting systems or topological insulators stimulate to develop new SARPES apparatuses and many sophisticated techniques have been reported recently. Here we report our newly developed a SARPES apparatus for spin vectorial analysis with high precision at Hiroshima Synchrotron Radiation Center. Highly efficient spin polarimeter utilizing very low energy electron diffraction (VLEED) makes high resolution (ΔE Japan Society for the Promotion of Science.

  6. High spin spectroscopy of 139 Pr

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 57; Issue 1. High spin spectroscopy of 139Pr. S Chanda Sarmishtha Bhattacharyya Tumpa Bhattacharjee S S Ghugre Swapan Kumar Basu S Muralithar R P Singh B Mukherjee R K Bhowmik S N Ray. Contributed Papers : Nuclear spectroscopy Volume 57 Issue 1 July ...

  7. High spin rotational bands in Zn

    Indian Academy of Sciences (India)

    July 2001 physics pp. 181–184. High spin rotational bands in. 65. Zn. B MUKHERJEE, S MURALITHAR, R P SINGH, R KUMAR, K RANI and. R K BHOWMIK. Nuclear Science Centre, Aruna Asaf Ali Marg, P.B. No. .... resolved due to poor resolution of the detectors used. The measured DCO ratios for the 835,. 988, 1074 ...

  8. Nuclear structure of Ra at high spin

    Indian Academy of Sciences (India)

    However, nuclear structure at high spin and excitation energies (∼ 6 MeV) would require a coupling of excited 1p–1h with 208Pb core. The coupling between single- particle orbitals and collective vibrations of core complicates the simple shell model picture. With increasing neutron number, Ra isotopes show an abrupt ...

  9. Spin Transport in High-Quality Suspended Graphene Devices

    NARCIS (Netherlands)

    Guimaraes, Marcos H. D.; Veligura, A.; Zomer, P. J.; Maassen, T.; Vera-Marun, I. J.; Tombros, N.; van Arees, B. J.; Wees, B.J. van

    We measure spin transport in high mobility suspended graphene (mu approximate to 10(5)cm(2)/(V s)), obtaining a (spin) diffusion coefficient of 0.1 m(2)/s and giving a lower bound on the spin relaxation time (tau(s) approximate to 150 ps) and spin relaxation length (lambda(s) = 4.7 mu m) for

  10. Simultaneous quantification of retinol, retinal, and retinoic acid isomers by high-performance liquid chromatography with a simple gradiation.

    Science.gov (United States)

    Miyagi, M; Yokoyama, H; Shiraishi, H; Matsumoto, M; Ishii, H

    2001-06-15

    A new method of high-performance liquid chromatography (HPLC) analysis to quantify isomers of retinol, retinal and retinoic acid simultaneously was established. The HPLC system consisted of a silica gel absorption column and a linear gradient with two kinds of solvents containing n-Hexane, 2-propanol, and glacial acetic acid in different ratios. It separated six retinoic acid isomers (13-cis, 9-cis, all-trans, all-trans-4-oxo, 9-cis-4-oxo, 13-cis-4-oxo), three retinal isomers (13-cis-, 9-cis-, and all-trans) and two retinol isomers (13-cis- and all-trans). Human serum samples were subjected to this HPLC analysis and at least, all-trans retinol, 13-cis retinol, and all-trans retinoic acid were detectable. This HPLC system is useful for evaluating retinoic acid formation from retinol via a two-step oxidation pathway. Moreover, it could be applied to monitoring the concentrations of various retinoids, including all-trans retinoic acid in human sera.

  11. Strontium Oxide Tunnel Barriers for High Quality Spin Transport and Large Spin Accumulation in Graphene.

    Science.gov (United States)

    Singh, Simranjeet; Katoch, Jyoti; Zhu, Tiancong; Wu, Ryan J; Ahmed, Adam S; Amamou, Walid; Wang, Dongying; Mkhoyan, K Andre; Kawakami, Roland K

    2017-11-16

    The quality of the tunnel barrier at the ferromagnet/graphene interface plays a pivotal role in graphene spin valves by circumventing the impedance mismatch problem, decreasing interfacial spin dephasing mechanisms and decreasing spin absorption back into the ferromagnet. It is thus crucial to integrate superior tunnel barriers to enhance spin transport and spin accumulation in graphene. Here, we employ a novel tunnel barrier, strontium oxide (SrO), onto graphene to realize high quality spin transport as evidenced by room-temperature spin relaxation times exceeding a nanosecond in graphene on silicon dioxide substrates. Furthermore, the smooth and pinhole-free SrO tunnel barrier grown by molecular beam epitaxy (MBE), which can withstand large charge injection current densities, allows us to experimentally realize large spin accumulation in graphene at room temperature. This work puts graphene on the path to achieve efficient manipulation of nanomagnet magnetization using spin currents in graphene for logic and memory applications.

  12. High spin ↔ low spin ultrafast excitation and relaxation of an isolated iron(II complex.

    Directory of Open Access Journals (Sweden)

    Létard J.F.

    2013-03-01

    Full Text Available Picosecond and femtosecond time resolved pump-probe experiments make it possible to study both the low spin (LS to high spin (HS and high spin to low spin excitation and relaxation processes in the same isolated iron(II complex. We demonstrate that both LS → HS and HS → LS can be recorded by changing the pump wavelength and occur on the same time scale.

  13. Deep inelastic reactions and isomers in neutron-rich nuclei across the perimeter of the A = 180-190 deformed region

    Directory of Open Access Journals (Sweden)

    Dracoulis G.D.

    2014-03-01

    Full Text Available Recent results on high-spin isomers populated in deep-inelastic reactions in the transitional tungsten-osmium region are outlined with a focus on 190Os, 192Os and 194Os. As well as the characterization of several two-quasinutron isomers, the 12+ and 20+ isomers in 192Os are interpreted as manifestations of maximal rotation alignment within the neutron i13/2 and possibly proton h11/2 shells at oblate deformation.

  14. High-spin structure in 40K

    Science.gov (United States)

    Söderström, P.-A.; Recchia, F.; Nyberg, J.; Gadea, A.; Lenzi, S. M.; Poves, A.; Ataç, A.; Aydin, S.; Bazzacco, D.; Bednarczyk, P.; Bellato, M.; Birkenbach, B.; Bortolato, D.; Boston, A. J.; Boston, H. C.; Bruyneel, B.; Bucurescu, D.; Calore, E.; Cederwall, B.; Charles, L.; Chavas, J.; Colosimo, S.; Crespi, F. C. L.; Cullen, D. M.; de Angelis, G.; Désesquelles, P.; Dosme, N.; Duchêne, G.; Eberth, J.; Farnea, E.; Filmer, F.; Görgen, A.; Gottardo, A.; Grębosz, J.; Gulmini, M.; Hess, H.; Hughes, T. A.; Jaworski, G.; Jolie, J.; Joshi, P.; Judson, D. S.; Jungclaus, A.; Karkour, N.; Karolak, M.; Kempley, R. S.; Khaplanov, A.; Korten, W.; Ljungvall, J.; Lunardi, S.; Maj, A.; Maron, G.; Męczyński, W.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Molini, P.; Napoli, D. R.; Nolan, P. J.; Norman, M.; Obertelli, A.; Podolyak, Zs.; Pullia, A.; Quintana, B.; Redon, N.; Regan, P. H.; Reiter, P.; Robinson, A. P.; Şahin, E.; Simpson, J.; Salsac, M. D.; Smith, J. F.; Stézowski, O.; Theisen, Ch.; Tonev, D.; Unsworth, C.; Ur, C. A.; Valiente-Dobón, J. J.; Wiens, A.

    2012-11-01

    High-spin states of 40K have been populated in the fusion-evaporation reaction 12C(30Si,np)40K and studied by means of γ-ray spectroscopy techniques using one triple-cluster detector of the Advanced Gamma Tracking Array at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro. Several states with excitation energy up to 8 MeV and spin up to 10- have been discovered. These states are discussed in terms of J=3 and T=0 neutron-proton hole pairs. Shell-model calculations in a large model space have shown good agreement with the experimental data for most of the energy levels. The evolution of the structure of this nucleus is here studied as a function of excitation energy and angular momentum.

  15. 16th Workshop on High Energy Spin Physics

    CERN Document Server

    2016-01-01

    The Workshop will cover a wide range of spin phenomena at high and intermediate energies such as: recent experimental data on spin physics the nucleon spin structure and GPD's spin physics and QCD spin physics in the Standard Model and beyond T-odd spin effects polarization and heavy ion physics spin in gravity and astrophysics the future spin physics facilities spin physics at NICA polarimeters for high energy polarized beams acceleration and storage of polarized beams the new polarization technology related subjects The Workshop will be held in the Bogoliubov Laboratory of Theoretical Physics of the Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia. The program of the workshop will include plenary and parallel (if necessary) sessions. Plenary sessions will be held in the Conference Hall. Parallel sections will take place in the same building. There will be invited talks (up to 40 min) and original reports (20 min). The invited speakers will present new experimental and theoretical re...

  16. Observation of Proton Radioactivity of the (21+) High-Spin Isomerin 94Ag

    Energy Technology Data Exchange (ETDEWEB)

    Mukha, I.; Roeckl, E.; Doring, J.; Batist, L.; Blazhev, A.; Grawe, H.; Hoffman, C.R.; Huyse, M.; Janas, Z.; Kirchner, R.; La Commara,M.; Mazzocchi, C.; Plettner, C.; Tabor, S.L.; Van Duppen, P.; Wiedeking, M.

    2005-07-05

    We have observed direct one-proton decay of the (21{sup +}) isomer in the N=Z nuclide {sup 94}Ag into high-spin states in {sup 93}Pd by detecting protons in coincidence with {gamma}-{gamma} correlations and applying {gamma} gates based on known {sup 93}Pd levels. Two decay branches have been identified, with proton energies of 0.79(3) and 1.01(3) MeV and branching ratios of 1.9(5)% and 2.2(4)%, respectively. The corresponding partial half-life values are 21(6) and 18(4) s. The Q value of the direct proton decay of the (21{sup +}) isomer was found to be 5.78(3) MeV. The very small reduced widths of the observed proton decays might reflect dominating collective configurations in the (21{sup +}) isomer, and the fine structure of the proton spectrum might indicate a strong deformation of this state.

  17. High spin-filter efficiency and Seebeck effect through spin-crossover iron-benzene complex.

    Science.gov (United States)

    Yan, Qiang; Zhou, Liping; Cheng, Jue-Fei; Wen, Zhongqian; Han, Qin; Wang, Xue-Feng

    2016-04-21

    Electronic structures and coherent quantum transport properties are explored for spin-crossover molecule iron-benzene Fe(Bz)2 using density functional theory combined with non-equilibrium Green's function. High- and low-spin states are investigated for two different lead-molecule junctions. It is found that the asymmetrical T-shaped contact junction in the high-spin state behaves as an efficient spin filter while it has a smaller conductivity than that in the low-spin state. Large spin Seebeck effect is also observed in asymmetrical T-shaped junction. Spin-polarized properties are absent in the symmetrical H-shaped junction. These findings strongly suggest that both the electronic and contact configurations play significant roles in molecular devices and metal-benzene complexes are promising materials for spintronics and thermo-spintronics.

  18. Population of high-spin isomeric states following fragmentation of 238U

    Science.gov (United States)

    Bowry, M.; Podolyák, Zs.; Pietri, S.; Kurcewicz, J.; Bunce, M.; Regan, P. H.; Farinon, F.; Geissel, H.; Nociforo, C.; Prochazka, A.; Weick, H.; Al-Dahan, N.; Alkhomashi, N.; Allegro, P. R. P.; Benlliure, J.; Benzoni, G.; Boutachkov, P.; Bruce, A. M.; Denis Bacelar, A. M.; Farrelly, G. F.; Gerl, J.; Górska, M.; Gottardo, A.; Grębosz, J.; Gregor, N.; Janik, R.; Knöbel, R.; Kojouharov, I.; Kubo, T.; Kurz, N.; Litvinov, Yu. A.; Merchan, E.; Mukha, I.; Naqvi, F.; Pfeiffer, B.; Pfützner, M.; Plaß, W.; Pomorski, M.; Riese, B.; Ricciardi, M. V.; Schmidt, K.-H.; Schaffner, H.; Scheidenberger, C.; Simpson, E. C.; Sitar, B.; Spiller, P.; Stadlmann, J.; Strmen, P.; Sun, B.; Tanihata, I.; Terashima, S.; Valiente Dobón, J. J.; Winfield, J. S.; Wollersheim, H.-J.; Woods, P. J.

    2013-08-01

    Isomeric ratios have been determined for 23 metastable states identified in A≈200 nuclei from Pt to Rn near the valley of stability following fragmentation of 238U. This includes high-spin states with angular momenta ranging from (39/2)ℏ to 25ℏ. The experimental results are discussed together with those of similar experiments performed in this mass region. Isomeric ratios are compared with theoretical predictions where the angular momentum of the fragment arises purely due to the angular momentum of nucleons removed from the projectile. The theoretical yield of low-spin states is generally overestimated. In these cases the assumption of 100% feeding of the isomer may require modification. However, the yield of high-spin isomeric states [Im ≥ (39/2)ℏ] is significantly underestimated and highlights the requirement for a more complete theoretical framework in relation to the generation of fragment angular momentum. The enhanced population of high-spin states reported here is advantageous to future studies involving isomeric beams at fragmentation facilities such as the Rikagaku Kenkyusho RI Beam Factory (Japan) and next-generation facilities at the Facility for Antiproton and Ion Research (Germany) and Facility for Rare Isotope Beams (USA).

  19. Projected shell model analysis of multi-quasiparticle high-K isomers in sup 1 sup 7 sup 4 Hf

    CERN Document Server

    Zhou Xian Rong; Sun Yang; Long Gui Lu

    2002-01-01

    Multi-quasiparticle high-K states in sup 1 sup 7 sup 4 Hf are studied in the framework of the projected shell model. The calculation reproduces well the observed ground-state band as well as most of the two- and four-quasiparticle rotational bands. Some as yet unobserved high-K isomeric states in sup 1 sup 7 sup 4 Hf are predicted. Possible reasons for the existing discrepancies between calculation and experiment are discussed. It is suggested that the projected shell model may be a useful method for studying multi-quasiparticle high-K isomers and the K-mixing phenomenon in heavy deformed nuclei

  20. Highly sensitive method for the quantification of trans-linolenic acid isomers in trilinolenin of edible oils using an ionic liquid capillary column.

    Science.gov (United States)

    Guo, Qin; Jiang, Fan; Jin, Jing; Li, Qingpeng; Wang, Feng; Wang, Qiang; Ha, Yiming

    2017-11-01

    The polarities of linolenic acid isomers are very similar, and only a few studies to date have attempted to separate α-linolenic acid (ALA) isomers completely. The aim of this study was to fill this gap by developing and validating an accurate method for the analysis of ALA isomers in trilinolenin at 200, 220 and 240 °C using a gas chromatograph-flame ionization detector equipped with an SLB-IL111 capillary column. Results showed that eight ALA isomer standards were separated effectively using these optimized gas chromatographic conditions. The coefficient of determination was r(2) > 0.9994 in the linear range of each ALA isomer. The obtained limits of detection and limits of quantification of the ALA isomers were 0.02-0.08 ppm and 0.05-0.22 ppm, respectively. A high degree of reproducibility and percent recoveries between 96.2% and 106.5%, with coefficients of variation ranging from 0.82% to 0.97%, were achieved. The developed method has been successfully applied to the analysis of ALA isomers in heated pure trilinolenin as well as to trilinolenin in various edible oils, and the TALA isomerization pathways in heated trilinolenin were verified. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  1. High spins in gamma-soft nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Leander, G.A.; Frauendorf, S.; May, F.R.

    1982-01-01

    Nuclei which are soft with respect to the ..gamma.. shape degree of freedom are expected to have many different structures coexisting in the near-yrast regime. In particular, the lowest rotational quasi-particle in a high-j shell exerts a strong polarizing effect on ..gamma... The ..gamma.. to which it drives is found to vary smoothly over a 180/sup 0/ range as the position of the Fermi level varies. This simple rule is seen to have a direct connection with the energy staggering of alternate spin states in rotational bands. A diagram is presented which provides a general theoretical reference for experimental tests of the relation between ..gamma.., spin staggering, configuration, and nucleon number. In a quasicontinuum spectrum, the coexistence of different structures are expected to make several unrelated features appear within any one slice of sum energy and multiplicity. However, it is also seen that the in-band moment of inertia may be similar for many bands of different ..gamma...

  2. Direct transitions from high-K isomers to low-K bands -- {gamma} softness or coriolis coupling

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Yoshifumi R.; Narimatsu, Kanako; Ohtsubo, Shin-Ichi [Kyushu Univ., Fukuoka (Japan)] [and others

    1996-12-31

    Recent measurements of direct transitions from high-K isomers to low-K bands reveal severe break-down of the K-selection rule and pose the problem of how to understand the mechanism of such K-violation. The authors recent systematic calculations by using a simple {gamma}-tunneling model reproduced many of the observed hindrances, indicating the importance of the {gamma} softness. However, there are some data which cannot be explained in terms of the {gamma}-degree of freedom. In this talk, the authors also discuss the results of conventional Coriolis coupling calculations, which is considered to be another important mechanism.

  3. Structure of high-spin states in A {approx} 60 region

    Energy Technology Data Exchange (ETDEWEB)

    Nakada, Hitoshi [Chiba Univ. (Japan); Furutaka, K.; Hatsukawa, Y. [and others

    1998-03-01

    High-spin states in the proton-rich Cu-Zn nuclei are investigated by the experiments at JAERI. New levels and {gamma}-rays are identified by the particle-{gamma}-{gamma} coincidence, and J{sup P} assignments are made via the DCO ratio analysis. Yrast sequences are observed up to J {approx} 18 for {sup 62}Zn, and {sup 64}Zn, J {approx} 27/2 for {sup 61}Cu and J {approx} 23/2 for {sup 63}Cu. Though we cannot settle new J{sup P} values for {sup 61,63}Zn, their yrast sequence is also extended. In {sup 64}Zn, a doublet of {gamma}-rays is discovered at 1315 keV, clarifying the similarity in the level scheme between {sup 62}Zn and {sup 64}Zn. We reproduce the yrast levels by a shell-model calculation, by which structure of the high-spin states is further studied. A parity change in the yrast sequence is established, in which the unique-parity orbit 0g{sub 9/2} plays an essential role; one nucleon excitation to g{sub 9/2} gains high angular momentum with low seniority, at the cost of the single-parity energy. Second parity-change is also suggested by the calculation. Such parity change seems characteristic to spherical or nearly spherical nuclei. In {sup 61}Cu, concentration of the {gamma}-ray intensity is observed. This happens because a stretched 3-quasiparticle configuration including 0g{sub 9/2} is relatively stable, similarly to some isomers. Thus, by studying the structure of the high-spin states of the A {approx} 60 nuclei, we have clarified the role of unique-parity orbit in high-spin states, which may be generic to spherical and nearly spherical nuclei. (J.P.N.)

  4. High Spin Baryons in Quantum Mechanical Chromodynamics

    Science.gov (United States)

    Kirchbach, M.; Compean, C. B.

    2009-04-01

    A framework of quantum mechanical chromodynamics (QMCD) is developed with the aim to place the description of the nucleon on a comparable footing with Schrödinger's quantum mechanical treatment of the hydrogen atom. Such indeed turns out to be possible upon replacing the (e--p) by a (q-qq) system, on the one hand, and the Coulomb potential by the recently reported by us exactly solvable trigonometric extension of the Cornell (TEC) potential, on the other. The TEC potential translates the inverse distance potential in ordinary flat space to a space of constant positive curvature, the 3D hypersphere, a reason for which both potentials have the SO(4) and SO(2, 1) symmetries in common. In effect, the nucleon spectrum, inclusive its Δ branch, acquire the degeneracy patterns of the electron excitations with spin in 1H without copying them, however. There are two essential differences between the N(Δ) and H atom spectra. The first concerns the parity of the states which can be unnatural for the N and Δ excitations due to compositeness of the diquark, the second refers to the level splittings in the baryon spectra which contain besides the Balmer term also its inverse of opposite sign. Our scheme reproduces the complete number of states (except the hybrid Δ(1600)), predicts a total of 33 new resonances, and explains the splittings of the N and Δ levels containing high-spin resonances. It also describes accurately the proton electric charge form factor. We here calculate the potential in momentum space (instantaneous effective gluon propagator) as a Fourier transform of the TEC potential and show that the concept of curvature allows to avoid the integral divergences suffered by schemes based on power potentials. We find a propagator that is finite at origin, likely to produce confinement. The advocated new potential picture allows for deconfinement too as effect of space flattening in the limit of infinite radius of the 3D hypersphere. The potential's SO(4)/SO(2, 1

  5. The Creation and Destruction of Hf-178m2 Isomer by Neutron Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hsiao-Hua [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); TechSource, Inc. Los Alamos, NM (United States); Talbert, Willard L. [TechSource, Inc. Los Alamos, NM (United States); Ward, Tom [TechSource, Inc. Los Alamos, NM (United States)

    2017-03-06

    The property of the isomer state in 178m2Hf was an interesting topic in nuclear structure studies during the time period 1970 to 1980. The state at 2.446 MeV with spin and parity Kπ = 16+, has a half-life of 31 years. The isomer is described as a four-quasi-particle state. The K forbidden deexcitatiion by gamma emission is the reason for long half-life. During 1980, the isomer became a troublesome issue for radiation safety workers, because this isomer can also be produced in the first wall of a fussion reactor containing tungsten and also in a tungsten beam stop of a high-energy accelerator.

  6. High spin properties of 124 Ba

    Indian Academy of Sciences (India)

    The 124Ba nucleus is investigated on the basis of the method of statistical mechanics by assuming the nucleons to move in triaxially deformed Nilsson potential. The variation in the Fermi energies of protons and neutrons is studied as a function of spin and temperature. The Fermi energies determined as a function of ...

  7. K-isomers in Hf nuclei at and beyond the neutron-rich edge of beta-stability

    CERN Document Server

    Chowdhury, P; Seabury, E H; Walker, P M; Wheldon, C; Ahmad, I; Carpenter, M P; Hackman, G; Janssens, R V F; Khoo, T L; Nisius, D; Reiter, P

    1999-01-01

    New high-K isomers are populated in sup 1 sup 8 sup 0 sup , sup 1 sup 8 sup 1 sup , sup 1 sup 8 sup 2 Hf nuclei via inelastic excitation and transfer reactions, using pulsed sup 2 sup 3 sup 8 U beams on Hf targets. The new data explore K-hindrances for different multipolarities and the role of residual spin-spin interactions for multi-quasiparticle (qp) configurations at the neutron-rich edge of the beta-stability line. The mapping of 4-qp K-isomers in the A approx 180 region is extended into neutron-rich territory.

  8. Isomer probes of nuclear structure following deep inelastic collisions

    CERN Document Server

    Al-Garni, S A; Walker, P

    2002-01-01

    Deep-inelastic collisions of sup 1 sup 3 sup 6 Xe ions with tantalum, tungsten and rhenium targets have been used to study beta-decays and high-spin isomers in neutron-rich A approx 180 nuclei at the GSI on-line mass separator. In particular, gamma rays -associated with the decay of the previously identified K suppi = 37/2 sup - , T sub 1 sub / sub 2 = 51 min isomer in sup 1 sup 7 sup 7 Hf have been observed, but with an unexpectedly high yield considering the release efficiency for short-lived hafnium isotopes from a thermal ion source. These results may be interpreted as possible evidence for a hitherto unrecognised, high-spin beta-decaying isomer in sup 1 sup 7 sup 7 Lu. A two-component half-life analysis of the sup 1 sup 7 sup 7 Hf gamma-ray intensities gives an upper-lying component of 6 + 3 - 2 min, when the lower-lying component half-life is fixed at 51 min. Nilsson multi-quasiparticle calculations with BCS pairing predict a favoured K suppi = 39/2 sup - state in sup 1 sup 7 sup 7 Lu, which is a candid...

  9. Observational Signature of High Spin at the Event Horizon Telescope

    Science.gov (United States)

    Gralla, Samuel E.; Lupsasca, Alexandru; Strominger, Andrew

    2018-01-01

    We analytically compute the observational appearance of an isotropically emitting point source orbiting near a rapidly spinning black hole. The primary image moves on a vertical line segment, in contrast to the primarily horizontal motion of the spinless case. Secondary images, also on the vertical line, display a rich caustic structure. If detected, this unique signature could serve as a "smoking gun" for a high spin black hole in nature.

  10. Synthesis of a new cyclosporine-based stationary phase and separation behaviors toward aromatic positional isomers by high-performance liquid chromatography.

    Science.gov (United States)

    Liu, Wen-na; Fan, Jun; Lin, Chun; Zheng, Sheng-run; Zhang, Wei-guang

    2015-04-01

    A new cyclosporine-bonded stationary phase has been synthesized through the Staudinger reaction between azido cyclosporine A (CsA) and aminopropyl silica gel and applied in separations of six disubstituted aromatic analytes by high-performance liquid chromatography. For dimethyl phthalate, nitroaniline and chloronitrobenzene, their positional isomers were well-separated on this CsA stationary phase, in which the separation factor for m-/o-dimethyl phthalates was the biggest. For nitrotoluene, dichlorobenzene and benzenediol, the m-/o-isomers were co-eluted. Then, effects of chromatographic conditions (such as types and content of alcoholic modifiers) on separation of nitroaniline positional isomers have been investigated. Retention behaviors of nitroaniline isomers on the column exhibited the strengthening trend along with increasing carbon number of alcohols, from ethanol to 1-propanol, and to 1-butanol. A similar phenomenon was observed by lowering the content of alcohol. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Determination of Sudan I and a newly synthesized Sudan III positional isomer in the color additive D&C Red No. 17 using high-performance liquid chromatography.

    Science.gov (United States)

    Weisz, Adrian; James, India C; Tae, Christian J; Ridge, Clark D; Ito, Yoichiro

    2017-11-01

    Specifications in the Code of Federal Regulations for the color additive D&C Red No. 17 (Colour Index 26100) limit the levels of two subsidiary colors, 1-(phenylazo)-2-naphthol (Sudan I) and 1-[[2-(phenylazo)phenyl]azo]-2-naphthalenol (Sudan III o-isomer), to 3% and 2%, respectively. The present work reports the development of a high-performance liquid chromatography (HPLC) method for the quantitative determination of these subsidiary colors. Since Sudan III o-isomer needed to be synthesized for use as a reference material, a two-step procedure was devised: (i) preparative-scale synthesis of the intermediate 2-aminoazobenzene (2AAB) and its purification by counter-current chromatography and (ii) diazotization of 2AAB and coupling with 2-naphthol. Characterization of the newly synthesized Sudan III o-isomer is also reported. Sudan I and Sudan III o-isomer were quantified by using five-point calibration curves with data points ranging from 0.108 to 3.240% and 0.077 to 2.227% by weight, respectively. The HPLC method is rapid (14 min for the total analysis cycle) and simple to implement. It was applied to the analysis of test portions from 25 batches of D&C Red No. 17 submitted to the U.S. Food and Drug Administration (USFDA) for certification, and it has recently been implemented by USFDA for routine batch certification of that color additive.

  12. Safety assessment of a natural tomato oleoresin containing high amounts of Z-isomers of lycopene prepared with supercritical carbon dioxide.

    Science.gov (United States)

    Honda, Masaki; Higashiura, Takuma; Fukaya, Tetsuya

    2017-02-01

    Z-isomers of lycopene, which are abundantly present in processed tomato products, are more bioavailable than (all-E)-lycopene found predominantly in raw tomatoes. Despite extensive studies on the bioavailability and biological activities of Z-isomers of lycopene, detailed studies on their safety and toxicology are limited. The geno-, acute and subacute toxicities of tomato oleoresin that contained high amounts of lycopene Z-isomers (10.9% lycopene with 66.3% Z-isomer content) and had been prepared with supercritical carbon dioxide were investigated. The oleoresin was non-mutagenic in the Ames test with and without metabolic activation (S9 mix). The medial lethal dose (LD50 ) of the oleoresin in rats, as determined by a single-dose oral test, was more than 5000 mg kg body weight-1 (bw) [361 mg (Z)-lycopene kg bw-1 ]. In the 4-week repeated-dose oral toxicity test, rats were administered oleoresin at 4500 mg kg-1 day-1 [325 mg (Z)-lycopene kg bw-1 day-1 ]. There were no clinically significant changes with respect to vital signs, physical examination outcomes and laboratory test values during the test period. Based on our findings and as supported by its long history of consumption, tomato oleoresin that contains high amounts of Z-isomers of lycopene prepared with supercritical carbon dioxide can be considered as safe for human consumption. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  13. High resolution separations of charge variants and disulfide isomers of monoclonal antibodies and antibody drug conjugates using ultra-high voltage capillary electrophoresis with high electric field strength.

    Science.gov (United States)

    Henley, W Hampton; He, Yan; Mellors, J Scott; Batz, Nicholas G; Ramsey, J Michael; Jorgenson, James W

    2017-11-10

    Ultra-high voltage capillary electrophoresis with high electric field strength has been applied to the separation of the charge variants, drug conjugates, and disulfide isomers of monoclonal antibodies. Samples composed of many closely related species are difficult to resolve and quantify using traditional analytical instrumentation. High performance instrumentation can often save considerable time and effort otherwise spent on extensive method development. Ideally, the resolution obtained for a given CE buffer system scales with the square root of the applied voltage. Currently available commercial CE instrumentation is limited to an applied voltage of approximately 30kV and a maximum electric field strength of 1kV/cm due to design limitations. The instrumentation described here is capable of safely applying potentials of at least 120kV with electric field strengths over 2000V/cm, potentially doubling the resolution of the best conventional CE buffer/capillary systems while decreasing analysis time in some applications. Separations of these complex mixtures using this new instrumentation demonstrate the potential of ultra-high voltage CE to identify the presence of previously unresolved components and to reduce analysis time for complex mixtures of antibody variants and drug conjugates. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. High-spin rotational bands in 123I

    Science.gov (United States)

    Singh, Purnima; Singh, A. K.; Wilson, A. N.; Ragnarsson, I.; Hübel, H.; Bürger, A.; Carpenter, M. P.; Chmel, S.; Fallon, P.; Hagemann, G. B.; Herskind, B.; Ha, Hoa; Janssens, R. V. F.; Juhász, K.; Kardan, A.; Khoo, T. L.; Kondev, G.; Korichi, A.; Lauritsen, T.; Nyakó, B. M.; Rogers, J.; Sletten, G.; Timár, J.; Zhu, S.

    2012-12-01

    High-spin states in 123I were populated in the reaction 80Se(48Ca,p4n)123I at a beam energy of 207 MeV and γ-ray coincidence events were measured using the Gammasphere spectrometer. Three weakly populated, high-spin rotational bands have been discovered with characteristics similar to those of the long collective bands recently observed in other nuclei of this mass region. Configuration assignments are proposed based on calculations within the framework of the cranked Nilsson-Strutinsky approach.

  15. High-power 95 GHz pulsed electron spin resonance spectrometer

    Science.gov (United States)

    Hofbauer, W.; Earle, K. A.; Dunnam, C. R.; Moscicki, J. K.; Freed, J. H.

    2004-05-01

    High-field/high-frequency electron spin resonance (ESR) offers improved sensitivity and resolution compared to ESR at conventional fields and frequencies. However, most high-field/high-frequency ESR spectrometers suffer from limited mm-wave power, thereby requiring long mm-wave pulses. This precludes their use when relaxation times are short, e.g., in fluid samples. Low mm-wave power is also a major factor limiting the achievable spectral coverage and thereby the multiplex advantage of Fourier transform ESR (FTESR) experiments. High-power pulses are needed to perform two-dimensional (2D) FTESR experiments, which can unravel the dynamics of a spin system in great detail, making it an excellent tool for studying spin and molecular dynamics. We report on the design and implementation of a high-power, high-bandwidth, pulsed ESR spectrometer operating at 95 GHz. One of the principal design goals was the ability to investigate dynamic processes in aqueous samples at physiological temperatures with the intent to study biological systems. In initial experiments on aqueous samples at room temperature, we achieved 200 MHz spectral coverage at a sensitivity of 1.1×1010√s spins and a dead time of less than 50 ns. 2D-electron-electron double resonance experiments on aqueous samples are discussed to demonstrate the practical application of such a spectrometer.

  16. UTSA-74: A MOF-74 Isomer with Two Accessible Binding Sites per Metal Center for Highly Selective Gas Separation.

    Science.gov (United States)

    Luo, Feng; Yan, Changsheng; Dang, Lilong; Krishna, Rajamani; Zhou, Wei; Wu, Hui; Dong, Xinglong; Han, Yu; Hu, Tong-Liang; O'Keeffe, Michael; Wang, Lingling; Luo, Mingbiao; Lin, Rui-Biao; Chen, Banglin

    2016-05-04

    A new metal-organic framework Zn2(H2O)(dobdc)·0.5(H2O) (UTSA-74, H4dobdc = 2,5-dioxido-1,4-benzenedicarboxylic acid), Zn-MOF-74/CPO-27-Zn isomer, has been synthesized and structurally characterized. It has a novel four coordinated fgl topology with one-dimensional channels of about 8.0 Å. Unlike metal sites in the well-established MOF-74 with a rod-packing structure in which each of them is in a five coordinate square pyramidal coordination geometry, there are two different Zn(2+) sites within the binuclear secondary building units in UTSA-74 in which one of them (Zn1) is in a tetrahedral while another (Zn2) in an octahedral coordination geometry. After activation, the two axial water molecules on Zn2 sites can be removed, generating UTSA-74a with two accessible gas binding sites per Zn2 ion. Accordingly, UTSA-74a takes up a moderately high and comparable amount of acetylene (145 cm(3)/cm(3)) to Zn-MOF-74. Interestingly, the accessible Zn(2+) sites in UTSA-74a are bridged by carbon dioxide molecules instead of being terminally bound in Zn-MOF-74, so UTSA-74a adsorbs a much smaller amount of carbon dioxide (90 cm(3)/cm(3)) than Zn-MOF-74 (146 cm(3)/cm(3)) at room temperature and 1 bar, leading to a superior MOF material for highly selective C2H2/CO2 separation. X-ray crystal structures, gas sorption isotherms, molecular modeling, and simulated and experimental breakthroughs comprehensively support this result.

  17. UTSA-74: A MOF-74 Isomer with Two Accessible Binding Sites per Metal Center for Highly Selective Gas Separation

    KAUST Repository

    Luo, Feng

    2016-04-26

    A new metal-organic framework Zn2(H2O)-(dobdc)·0.5(H2O) (UTSA-74, H4dobdc = 2,5-dioxido-1,4-benzenedicarboxylic acid), Zn-MOF-74/CPO-27-Zn isomer, has been synthesized and structurally characterized. It has a novel four coordinated fgl topology with one-dimensional channels of about 8.0 Å. Unlike metal sites in the wellestablished MOF-74 with a rod-packing structure in which each of them is in a five coordinate square pyramidal coordination geometry, there are two different Zn2+ sites within the binuclear secondary building units in UTSA-74 in which one of them (Zn1) is in a tetrahedral while another (Zn2) in an octahedral coordination geometry. After activation, the two axial water molecules on Zn2 sites can be removed, generating UTSA-74a with two accessible gas binding sites per Zn2 ion. Accordingly, UTSA-74a takes up a moderately high and comparable amount of acetylene (145 cm3/cm3) to Zn-MOF-74. Interestingly, the accessible Zn2+ sites in UTSA-74a are bridged by carbon dioxide molecules instead of being terminally bound in Zn-MOF-74, so UTSA-74a adsorbs a much smaller amount of carbon dioxide (90 cm3/cm3) than Zn-MOF-74 (146 cm3/cm3) at room temperature and 1 bar, leading to a superior MOF material for highly selective C2H2/CO2 separation. X-ray crystal structures, gas sorption isotherms, molecular modeling, and simulated and experimental breakthroughs comprehensively support this result. © 2016 American Chemical Society.

  18. Spins in the vortices of a high-temperature superconductor

    DEFF Research Database (Denmark)

    Lake, B.; Aeppli, G.; Clausen, K.N.

    2001-01-01

    Neutron scattering is used to characterize the magnetism of the vortices for the optimally doped high-temperature superconductor La2-xSrxCuO4 (x = 0.163) in an applied magnetic field. As temperature is reduced, Low-frequency spin fluctuations first disappear with the loss of vortex mobility......, but then reappear. We find that the vortex state can be regarded as an inhomogeneous mixture of a superconducting spin fluid and a material containing a nearly ordered antiferromagnet. These experiments show that as for many other properties of cuprate superconductors, the important underlying microscopic forces...

  19. High spin polarization and spin splitting in equiatomic quaternary CoFeCrAl Heusler alloy

    Energy Technology Data Exchange (ETDEWEB)

    Bainsla, Lakhan; Mallick, A.I. [Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India); Coelho, A.A. [Instituto de Física “Gleb Wataghin”, Universidade Estadual de Campinas-UNICAMP, SP 6165, Campinas 13 083-859, Sao Paulo (Brazil); Nigam, A.K. [DCMPMS, Tata Institute of Fundamental Research, Mumbai 4000052 (India); Varaprasad, B.S.D.Ch.S.; Takahashi, Y.K. [Magnetic Materials Unit, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Alam, Aftab [Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India); Suresh, K.G., E-mail: suresh@phy.iitb.ac.in [Department of Physics, Indian Institute of Technology Bombay, Mumbai 400076 (India); Hono, K. [Magnetic Materials Unit, National Institute for Materials Science, Tsukuba 305-0047 (Japan)

    2015-11-15

    In this paper, we investigate CoFeCrAl alloy by means of ab-initio electronic structure calculations and various experimental techniques. The alloy is found to exist in the B2-type cubic Heusler structure, which is very similar to Y-type (or LiMgPdSn prototype) structure with space group F-43m (#216). Saturation magnetization (M{sub S}) of about 2 µ{sub B}/f.u. is observed at 8 K under ambient pressure, which is in good agreement with the Slater–Pauling rule. M{sub S} values are found to be independent of pressure, which is a prerequisite for half-metals. The ab-initio electronic structure calculations predict half-metallicity for the alloy with a spin slitting energy of 0.31 eV. Importantly, this system shows a high current spin polarization value of 0.67±0.02, as deduced from the point contact Andreev reflection measurements. Linear dependence of electrical resistivity with temperature indicates the possibility of reasonably high spin polarization at elevated temperatures (~150 K) as well. All these suggest that CoFeCrAl is a promising material for the spintronic devices. - Highlights: • The ab-initio calculations predict half-metallic nature for the alloy. • Saturation magnetization (M{sub S}) gives characteristics of half-metallic nature. • Current spin polarization (P) value of 0.67±0.02 is deduced from PCAR measurements. • Deduced P is higher than those obtained for many ternary and/or quaternary alloys. • Resistivity behavior gives signature of high P at elevated temperatures.

  20. High-spin structure of neutron-rich Dy isotopes

    Indian Academy of Sciences (India)

    Abstract. In view of recent experimental progress on production and spectroscopy of neutron-rich isotopes of Dy with mass number A. 166 and 168, we have made theoretical investigations on the structure of high spin states of164 170Dy isotopes in the cranked Hartree–Fock–Bogoliubov (CHFB) theory employing a ...

  1. High-spin structure of yrast-band in Kr

    Indian Academy of Sciences (India)

    are in good agreement with the earlier measurements. [4]. The lifetimes measured and the transition quadrupole measurements can be seen in table 1. The present measurements show a drop in transition quadrupole moments at high-spins. (. 16 ). It is shown that the bandcrossing frequencies and the variation in t values ...

  2. Observation of high spin levels in Cs from Ba decay

    Indian Academy of Sciences (India)

    Abstract. The γ- and conversion electron spectra following 131Ba ε-decay are investigated, using. HPGe detector and mini-orange electron spectrometer. Attention is particularly focussed on iden- tifying weak transitions associated with low energy high spin levels in 131Cs level scheme earlier inferred in reaction studies but ...

  3. Determination of fucoxanthin isomers in microalgae (Isochrysis sp.) by high-performance liquid chromatography coupled with diode-array detector multistage mass spectrometry coupled with positive electrospray ionization.

    Science.gov (United States)

    Crupi, Pasquale; Toci, Aline Theodore; Mangini, Silvio; Wrubl, Federico; Rodolfi, Liliana; Tredici, Mario R; Coletta, Antonio; Antonacci, Donato

    2013-05-15

    Due to their health benefits, there is growing interest in the production and use of carotenoids from natural sources, e.g. microalgae. To date, only Haematococcus pluvialis and Dunaliella, that accumulate, respectively, astaxanthin and β-carotene in large quantities, are grown commercially. However, interest is also being focused on other xanthophylls, such as (all-E)-fucoxanthin characterized by anti-obesity and anti-carcinogenic effects. In this regard, rigorous chemical and analytical techniques following preparative isolation of components are needed to unequivocally identify individual carotenoids in microalgae. The carotenoid profile of Isochrysis sp. biomass, produced in closed photobioreactors, was determined by reversed-phase C30 (RP-30) high-performance liquid chromatography coupled with diode-array detector mass spectrometry using positive electrospray ionization (HPLC/DAD-MS/ESI(+) ) analysis. Additionally, multistage mass spectrometry (MS(n) ) analyses, together with fine structures of the UV-vis spectra, were used to differentiate structural and geometrical isomers. This technique allowed the simultaneous determination of geometrical, isomers of fucoxanthin (all-E-fucoxanthin, 13Z-, 13'Z- and 9'Z-fucoxanthin), diatoxanthin and 5,8-epoxydiadinoxanthin diasteroisomers (R/S). The analyzed extracts contained fucoxanthin isomers as the major carotenoids and, in particular, (all-E)-fucoxanthin was the main geometrical isomer (~85%) found at a concentration of 17 mg/g of the lyophilized biomass. Considering the high content of fucoxanthin in Isochrysis sp. biomass, the microalga could be proposed as a source of this compound for nutraceutical and pharmaceutical applications. Copyright © 2013 John Wiley & Sons, Ltd.

  4. Spin relaxation in high-spin iron(III) complexes of tretraphenylporphine

    Energy Technology Data Exchange (ETDEWEB)

    Ohya, Toshie; Sato, Mitsuo (Biophysics Div., Faculty of Pharmaceutical Sciences, Teikyo Univ., Sagamiko, Kanagawa (Japan))

    1993-04-01

    The Moessbauer spectra of Fe(por)X (por=tetraphenylporphinato, TPP, and tetrakis(p-chlorophenyl)porphinato, Tp-CIPP, dianions; X=Cl, Br and I) have been measured. They show varying quadrupolar pattern depending on the temperature: Asymmetric broadening of the high-velocity line at higher temperatures, a symmetric doublet at a temperature T[sub r], and a reversal in asymmetry below T[sub r]. The temperature dependence results from temperature-dependent spin-spin relaxation in high-spin iron(III) and the off-diagonal terms of the hyperfine operator, and reflects the ionic zero-field splitting. For a given X, T[sub r] is higher and the quadrupole splitting, [Delta]E[sub Q], is larger for Tp-CIPP derivatives than for TPP derivatives. The result is explained on the basis of the resonance effect of the p-chloro substituents of the meso-phenyl groups. When por is fixed, both the values of T[sub r] and [Delta]E[sub Q] are in the order Cl

  5. Benzene and its Isomers

    Indian Academy of Sciences (India)

    Compared to our present vast knowledge of extremely complex structures of thousands of organic compounds, the struc- .... None of the isomers, except benzene, has much practical applica- tion. Yet the fascination of both synthetic and theoretical chemists for the isomers of benzene is so great that even after about 140 ...

  6. First example of a high-level correlated calculation of the indirect spin-spin coupling constants involving tellurium

    DEFF Research Database (Denmark)

    Rusakov, Yury Yu; Krivdin, Leonid B.; Østerstrøm, Freja From

    2013-01-01

    This paper documents a very first example of a high-level correlated calculation of spin-spin coupling constants involving tellurium taking into account relativistic effects, vibrational corrections and solvent effects for the medium sized organotellurium molecules. The 125Te-1H spin-spin coupling...... constants of tellurophene and divinyl telluride were calculated at the SOPPA and DFT levels in a good agreement with experiment. A new full-electron basis set av3z-J for tellurium derived from the "relativistic" Dyall's basis set, dyall.av3z, and specifically optimized for the correlated calculations...

  7. Spin polarization in high density quark matter

    DEFF Research Database (Denmark)

    Bohr, Henrik; Panda, Prafulla K.; Providênci, Constanca

    2013-01-01

    We investigate the occurrence of a ferromagnetic phase transition in high density hadronic matter (e.g., in the interior of a neutron star). This could be induced by a four-fermion interaction analogous to the one which is responsible for chiral symmetry breaking in the Nambu-Jona-Lasinio model, ...

  8. Molecular structure of the trans and cis isomers of metal-free phthalocyanine studied by gas-phase electron diffraction and high-level quantum chemical calculations: NH tautomerization and calculated vibrational frequencies.

    Science.gov (United States)

    Strenalyuk, Tatyana; Samdal, Svein; Volden, Hans Vidar

    2008-05-29

    The molecular structure of the trans isomer of metal-free phthalocyanine (H2Pc) is determined using the gas electron diffraction (GED) method and high-level quantum chemical calculations. B3LYP calculations employing the basis sets 6-31G**, 6-311++G**, and cc-pVTZ give two tautomeric isomers for the inner H atoms, a trans isomer having D2h symmetry and a cis isomer having C2v symmetry. The trans isomer is calculated to be 41.6 (B3LYP/6-311++G**, zero-point corrected) and 37.3 kJ/mol (B3LYP/cc-pVTZ, not zero-point corrected) more stable than the cis isomer. However, Hartree-Fock (HF) calculations using different basis sets predict that cis is preferred and that trans does not exist as a stable form of the molecule. The equilibrium composition in the gas phase at 471 degrees C (the temperature of the GED experiment) calculated at the B3LYP/6-311++G** level is 99.8% trans and 0.2% cis. This is in very good agreement with the GED data, which indicate that the mole fraction of the cis isomer is close to zero. The transition states for two mechanisms of the NH tautomerization have been characterized. A concerted mechanism where the two H atoms move simultaneously yields a transition state of D2h symmetry and an energy barrier of 95.8 kJ/mol. A two-step mechanism where a trans isomer is converted to a cis isomer, which is converted into another trans isomer, proceeds via two transition states of C(s) symmetry and an energy barrier of 64.2 kJ/mol according to the B3LYP/6-311++G** calculation. The molecular geometry determined from GED is in very good agreement with the geometry obtained from the quantum chemical calculations. Vibrational frequencies, IR, and Raman intensities have been calculated using B3LYP/6-311++G**. These calculations indicate that the molecule is rather flexible with six vibrational frequencies in the range of 20-84 cm(-1) for the trans isomer. The cis isomer might be detected by infrared matrix spectroscopy since the N-H stretching frequencies are

  9. High temperature resistant nanofiber by bubbfil-spinning

    Directory of Open Access Journals (Sweden)

    Li Ya

    2015-01-01

    Full Text Available Heat-resisting nanofibers have many potential applications in various industries, and the bubbfil spinning is the best candidate for mass-production of such materials. Polyether sulfone/zirconia solution with a bi-solvent system is used in the experiment. Experimental result reveals that polyether sulfone/zirconia nanofibers have higher resistance to high temperature than pure polyether sulfone fibers, and can be used as high-temperature-resistant filtration materials.

  10. Collective high spin states in {sup 45}Sc

    Energy Technology Data Exchange (ETDEWEB)

    Bednarczyk, P. [Institute of Nuclear Physics, Krakow (Poland)]|[INFN, Laboratori Nazionali di Legnaro, Legnaro (Italy); Styczen, J. [Institute of Nuclear Physics, Krakow (Poland); Broda, R. [Institute of Nuclear Physics, Krakow (Poland); Lach, M. [Institute of Nuclear Physics, Krakow (Poland); Meczynski, W. [Institute of Nuclear Physics, Krakow (Poland); Bazzacco, D. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Brandolini, F. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); De Angelis, G. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Italy); Lunardi, S. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Mueller, L. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Medina, N. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Petrache, C. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Italy); Rossi-Alvarez, C. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Scarlassara, F. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Segato, G.F. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Signorini, C. [Dipartimento di Fisica dell`Universita and INFN, Padova (Italy); Soramel, F. [Dipartimento di Fisica dell`Universita and INFN, Udine (Italy)

    1995-02-06

    The high-spin states in {sup 45}Sc were studied with the GASP multidetector array. The nuclei were excited by the {sup 30}Si({sup 18}O,p2n){sup 45}Sc reaction at E{sub LAB}=60 MeV and separated with the Recoil Mass Spectrometer. Several new high-spin levels extending the known single-particle and collective structures were observed. Energies of the negative-parity states agree with the shell model predictions whereas the positive-parity-intruder rotational band extends up to very high rotational frequencies and continues beyond the maximum angular momentum available from the single-particle f{sub 7/2} configuration. ((orig.)).

  11. Metal-Ligand Multiple Bonds in High-Spin Complexes

    OpenAIRE

    King, Evan

    2012-01-01

    The chemistry of late first row transition metals supported by dipyrromethane and dipyrromethene ligands bearing sterically bulky substituents was explored. Transition metal complexes (Mn, Fe, Co, Ni, Zn) of the dipyrromethane ligand 1,9-dimesityl-5,5-dimethyldipyrromethane (dpma) were prepared. Structural and magnetic characterization (SQUID, EPR) of the bis-pyridine adducts \\((dpma)Mn(py)_2\\), \\((dpma)Fe(py)_2\\), and \\((dpma)Co(py)_2\\) showed each tetrahedral divalent ion to be high-spin, w...

  12. GHG effects of spinning reserve for high penetration renewables

    Energy Technology Data Exchange (ETDEWEB)

    Louis Wibberley; Peter Scaife; Joe Winsen

    2008-03-15

    This study gives a high level assessment of the greenhouse gas cost implications of providing additional backup for intermittent renewable power at a high level (20%) of penetration. The report considers international experience with higher levels of renewable generation, the Australian electricity system, and the current and likely future levels of renewables on the grids. To enable coal to provide back up/spinning reserve with a high degree of flexibility it is proposed that direct injected coal engines and novel gasification/gas engine combinations be considered. 31 refs., 17 figs., 6 tabs.

  13. High Frequency QPOs due to Black Hole Spin

    Science.gov (United States)

    Kazanas, Demos; Fukumura, K.

    2009-01-01

    We present detailed computations of photon orbits emitted by flares at the innermost stable circular orbit (ISCO) of accretion disks around rotating black holes. We show that for sufficiently large spin parameter, i.e. a > 0.94 M, flare a sufficient number of photons arrive at an observer after multiple orbits around the black hole, to produce an "photon echo" of constant lag, i.e. independent of the relative phase between the black hole and the observer, of T approximates 14 M. This constant time delay, then, leads to a power spectrum with a QPO at a frequency nu approximates 1/14M, even for a totally random ensemble of such flares. Observation of such a QPO will provide incontrovertible evidence for the high spin of the black hole and a very accurate, independent, measurement of its mass.

  14. High-spin states in sup 183 Pt

    Energy Technology Data Exchange (ETDEWEB)

    Nyberg, J. (Manne Siegbahn Inst. of Physics, Stockholm (Sweden) Royal Inst. of Tech., Stockholm (Sweden). Physics Dept. 1 Niels Bohr Inst., Roskilde (Denmark). Tandem Accelerator Lab.); Johnson, A. (Manne Siegbahn Inst. of Physics, Stockholm (Sweden) Royal Inst. of Tech., Stockholm (Sweden). Physics Dept. 1); Carpenter, M.P.; Bingham, C.R.; Courtney, L.H.; Janzen, V.P.; Juutinen, S.; Larabee, A.J.; Liu, Z.M.; Riedinger, L.L. (Tennessee Univ., Knoxville (USA). Dept. of Physics); Baktash, C.; Halbert, M.L.; Johnson, N.R.; Lee, I.Y.; Schutz, Y. (Oak Ridge National Lab., TN (USA). Holifield Heavy Ion Research Facility); Waddington, J.C.; Popescu, D.G. (McMaster Univ., Hamilton, Ontario (Canada). Tandem Accelerator Lab.)

    1990-04-30

    High-spin states in {sup 183}Pt have been studied for the first time using the reactions {sup 154}Sm({sup 34}S, 5n) and {sup 170}Yb({sup 16}O,3n). Rotational bands built on the Nilsson configurations 1/2{sup -}(521), 7/2{sup -}(514) and 9/2{sup +}(624) were observed up to spin values of 39/2-49/2{Dirac h}. Quasiparticle alignments and band crossing frequencies were investigated in these bands. A large signature splitting was observed in the {nu}i{sub 13/2}-band structure. The experimental results were compared with total routhian surface calculations, in which the shape of the nucleus could be followed as a function of rotational frequency for different quasiparticle configurations. (orig.).

  15. High current gain silicon-based spin transistor

    CERN Document Server

    Dennis, C L; Ensell, G J; Gregg, J F; Thompson, S M

    2003-01-01

    A silicon-based spin transistor of novel operating principle has been demonstrated in which the current gain at room temperature is 1.4 (n-type) and 0.97 (p-type). This high current gain was obtained from a hybrid metal/semiconductor analogue to the bipolar junction transistor which functions by tunnel-injecting carriers from a ferromagnetic emitter into a diffusion driven silicon base and then tunnel-collecting them via a ferromagnetic collector. The switching of the magnetic state of the collector ferromagnet controls the collector efficiency and the current gain. Furthermore, the magnetocurrent, which is determined to be 98% (140%) for p-type (n-type) in -110 Oe, is attributable to the spin-polarized base diffusion current.

  16. Summary of the 9th international symposium on high energy spin-physics

    Energy Technology Data Exchange (ETDEWEB)

    Prescott, C.Y.

    1990-11-01

    Summarizing an international conference in high energy spin physics is never an easy task, because of the wide-ranging subjects in physics and technology that are involved. I have chosen to organize the topics of this conference into three broad categories relating to spin; intrinsic spin; composite spin; and spin, the experimental tool. In the first category, I will briefly revisit some historical and recent developments to set a background. In the second category, composite spin, I will discuss the status and developments in several areas, including magnetic moments of baryons, hyperon polarization in high energy high p {perpendicular} production, transverse polarization and asymmetries from transversely polarized targets in high p {perpendicular} scattering, spin structure of the proton, and the Bjorken sum rule. In the third category, I will discuss the steady, and at times rapid, progress in spin technology. In this part I include recent progress in high energy facilities, and comment on the highlights of the Workshops.

  17. An efficient method for high-purity anthocyanin isomers isolation from wild blueberries and their radical scavenging activity.

    Science.gov (United States)

    Chorfa, Nasima; Savard, Sylvain; Belkacemi, Khaled

    2016-04-15

    An efficient process for the purification of anthocyanin monomeric isomers from wild blueberries of Lake Saint-Jean region (Quebec, Canada) was developed and easy scalable at industrial purpose. The blueberries were soaked in acidified ethanol, filtered, and the filtrate was cleaned by solid phase extraction using silica gel C-18 and DSC-SCX cation-exchange resin. Anthocyanin-enriched elutes (87 wt.%) were successfully fractionated by preparative liquid chromatography. The major anthocyanins mono-galactoside, -glucoside and -arabinoside isomers of delphinidin, cyanidin, petunidin, peonidin and malvidin were isolated with a purity up to 100% according to their LC-MS and (1)H NMR spectra. The oxygen radical absorbance capacity (ORAC) of the obtained pure anthocyanins was evaluated. Delphinidin-3-galactoside has the highest capacity (13.062 ± 2.729 μmol TE/μmol), and malvidin-3-glucoside the lowest (0.851 ± 0.032 μmol TE/μmol). A mechanistic pathway preview is suggested for the anthocyanins scavenging free radical activity by hydrogen transfer. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Medium and high spin structure in the 94Y isotope produced in fission induced by cold neutrons

    Science.gov (United States)

    Iskra, Ł. W.; Fornal, B.; Leoni, S.; Bocchi, G.; Blanc, A.; Bottoni, S.; Cieplicka-Oryńczak, N.; Jentschel, M.; Köster, U.; Michelagnoli, C.; Mutti, P.; Soldner, T.; de France, G.; Simpson, G. S.; Ur, C. A.; Urban, W.

    2017-10-01

    The level scheme of the neutron-rich 94Y isotope has been extended up to the 5324 keV excitation energy. During the analysis, a structure above the previously known (5+) isomer, at 1202 keV, was extended by employing multifold gamma-ray coincidence relationships measured with the EXILL array. For some of the new states, the spin-parity assignment has been proposed on the basis of gamma angular correlations and shell-model considerations. The newly identified structure is characteristic of spherical or nearly spherical configurations and no evidence for new isomers and rotational patterns was found.

  19. Monopole-Driven Shell Evolution below the Doubly Magic Nucleus Sn132 Explored with the Long-Lived Isomer in Pd126

    Science.gov (United States)

    Watanabe, H.; Lorusso, G.; Nishimura, S.; Otsuka, T.; Ogawa, K.; Xu, Z. Y.; Sumikama, T.; Söderström, P.-A.; Doornenbal, P.; Li, Z.; Browne, F.; Gey, G.; Jung, H. S.; Taprogge, J.; Vajta, Zs.; Wu, J.; Yagi, A.; Baba, H.; Benzoni, G.; Chae, K. Y.; Crespi, F. C. L.; Fukuda, N.; Gernhäuser, R.; Inabe, N.; Isobe, T.; Jungclaus, A.; Kameda, D.; Kim, G. D.; Kim, Y. K.; Kojouharov, I.; Kondev, F. G.; Kubo, T.; Kurz, N.; Kwon, Y. K.; Lane, G. J.; Moon, C.-B.; Montaner-Pizá, A.; Moschner, K.; Naqvi, F.; Niikura, M.; Nishibata, H.; Nishimura, D.; Odahara, A.; Orlandi, R.; Patel, Z.; Podolyák, Zs.; Sakurai, H.; Schaffner, H.; Simpson, G. S.; Steiger, K.; Suzuki, H.; Takeda, H.; Wendt, A.; Yoshinaga, K.

    2014-07-01

    A new isomer with a half-life of 23.0(8) ms has been identified at 2406 keV in Pd126 and is proposed to have a spin and parity of 10+ with a maximally aligned configuration comprising two neutron holes in the 1h11/2 orbit. In addition to an internal-decay branch through a hindered electric octupole transition, β decay from the long-lived isomer was observed to populate excited states at high spins in Ag126. The smaller energy difference between the 10+ and 7- isomers in Pd126 than in the heavier N =80 isotones can be interpreted as being ascribed to the monopole shift of the 1h11/2 neutron orbit. The effects of the monopole interaction on the evolution of single-neutron energies below Sn132 are discussed in terms of the central and tensor forces.

  20. Development of a high performance liquid chromatography method for quantification of isomers β-caryophyllene and α-humulene in copaiba oleoresin using the Box-Behnken design.

    Science.gov (United States)

    de Almeida Borges, Vinícius Raphael; Ribeiro, Ana Ferreira; de Souza Anselmo, Carina; Cabral, Lúcio Mendes; de Sousa, Valéria Pereira

    2013-12-01

    The sesquiterpene isomers, β-Cariofileno (CAR) and α-Humuleno (HUM) are the primary constituents of the copaiba oleoresin species. These natural products are primarily used by the Amazonian population and marketed as phytotherapies and cosmetics. The aim of this study was to develop and validate a method that simultaneously assays the isomers present in copaiba oleoresins by high performance liquid chromatography using the Box-Behnken design. After preliminary studies, the reverse phase chromatographic system was selected using a cyano column and a mobile phase consisting of acetonitrile and phosphate buffer. The Box-Behnken design was applied at three levels and with four independent variables: flow rate (X1), gradient slope time (X2), proportion of organic compounds at the end of the gradient (X3) and at the beginning of the gradient (X4). Also, the responses of the dependent variables: CAR retention time (Y1) and the resolution between the CAR and HUM peaks (Y2) was assessed. The mathematical model obtained from the regression results was satisfactory (R(2)>0.98, n=27) and showed a quadratic relationship where the effects of interactions between the variables, was observed by response surface graphs. The simultaneous optimization method was used to establish the best compromise of the resolution between the CAR and HUM isomers while adjusting the retention time of CAR. This method was successfully optimized by BBD obtaining chromatographic peaks with good symmetry, resolution and separation efficiency. The validation of the developed method confirmed its specificity, precision, accuracy and linearity in the range of 5.0-11.0 and 0.4-1.0μg/mL for CAR and HUM, respectively, and is considered suitable for routine applications which assure quality control. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Identification of Apo- Carotenoids' Crocin and Crocetin Isomers in Saffron Crude Extracts by HPLC Coupled to Atmospheric Pressure Chemical Ionization and High Resolution Orbitrap Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Noraddin Hosseinpour azad

    2017-01-01

    Full Text Available The main metabolites in saffron are the Apo- carotenoids’ Crocin and Crocetin. Color intensity and quality of saffron mostly depend on the presence of Crocins that are glycosylated steric form of Crocetin by glycosyltransferase enzyme. The aim of this study is the characterization of these metabolites in methanolic and chloroformic extracts of saffron stigmas during anthesis stage by LC-APCI-MS. Identification of cis and trans isomers of Crocin and Crocetin was done by three parameters such as mass spectra registered in the negative ion mode, retention time and absorption ratio related to each metabolites. The variability of these parameters made it possible to detect the Crocins isomer with regard to the attached position and the number of UDP- glucose and Gentiobiosyl molecules to Crocetin structure. Crocins was the mainly detected components as there are polar components that are classified in the carotenoeids groups and the strified form of Crocetin Glucose (β-D-Glucopyranosyl and Gentiobiose (β-D-Glucopyranosyl-D-Glucose. Also doubly charged ions were found for trans-isomers of Crocin-4, due to the high symmetry of their molecules. Based on the data gathered, the applied chromatograph Machin in this project is accurate and it is most sensitive tools to investigate about plants’ natural components like saffron, also the used APCI-MS in negative ions mode is the most efficient method to distinguish different steric forms of Crocin based on the ion’s fragments related to united reduction of glycosyl and gentiobiosyl as well as molecular fractions.

  2. Thermodynamical analysis of spin-state transitions in LaCo O3 : Negative energy of mixing to assist thermal excitation to the high-spin excited state

    Science.gov (United States)

    Kyômen, Tôru; Asaka, Yoshinori; Itoh, Mitsuru

    2005-01-01

    Magnetic susceptibility and heat capacity due to the spin-state transition in LaCoO3 were calculated by a molecular-field model in which the energy-level diagram of high-spin state reported by Ropka and Radwanski [Phys. Rev. B 67, 172401 (2003)] is assumed for the excited state, and the energy and entropy of mixing of high-spin Co ions and low-spin Co ions are introduced phenomenologically. The experimental data below 300K were well reproduced by this model, which proposes that the high-spin excited state can be populated even if the energy of high-spin state is much larger than that of low-spin state, because the negatively large energy of mixing reduces the net excitation energy. The stability of each spin state including the intermediate-spin state is discussed based on the present results and other reports.

  3. Characterization of cis- and trans-octadecenoic acid positional isomers in edible fat and oil using gas chromatography-flame ionisation detector equipped with highly polar ionic liquid capillary column.

    Science.gov (United States)

    Yoshinaga, Kazuaki; Asanuma, Masaharu; Mizobe, Hoyo; Kojima, Koichi; Nagai, Toshiharu; Beppu, Fumiaki; Gotoh, Naohiro

    2014-10-01

    In this study, the characterisation of all cis- and trans-octadecenoic acid (C18:1) positional isomers in partially hydrogenated vegetable oil (PHVO) and milk fat, which contain several cis- and trans-C18:1 positional isomers, was achieved by gas chromatography-flame ionisation detector equipped with a highly polar ionic liquid capillary column (SLB-IL111). Prior to analysis, the cis- and trans-C18:1 fractions in PHVO and milk fat were separated using a silver-ion cartridge. The resolution of all cis-C18:1 positional isomers was successfully accomplished at the optimal isothermal column temperature of 120 °C. Similarly, the positional isomers of trans-C18:1, except for trans-6-C18:1 and trans-7-C18:1, were separated at 120 °C. The resolution of trans-6-C18:1 and trans-7-C18:1 isomers was made possible by increasing the column temperature to 160 °C. This analytical method is suitable for determining the cis- and trans-C18:1 positional isomers in edible fats and oils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Sub-picosecond time resolved infrared spectroscopy of high-spin state formation in Fe(II) spin crossover complexes

    DEFF Research Database (Denmark)

    Døssing, Anders Rørbæk; Wolf, Matthias M. N.; Gross, Ruth

    2008-01-01

      The photoinduced low-spin (S = 0) to high-spin (S = 2) transition of the iron(II) spin-crossover systems [Fe(btpa)](PF6)2 and [Fe(b(bdpa))](PF6)2 in solution have been studied for the first time by means of ultrafast transient infrared spectroscopy at room temperature. Negative and positive...... infrared difference bands between 1000 and 1065 cm-1 that appear within the instrumental system response time of 350 fs after excitation at 387 nm display the formation of the vibrationally unrelaxed and hot high-spin 5T2 state. Vibrational relaxation is observed and characterized by the time constants 9.......4 ± 0.7 ps for [Fe(btpa)](PF6)2/acetone and 12.7 ± 0.7 ps for both [Fe(btpa)](PF6)2/acetonitrile and [Fe(b(bdpa)](PF6)2/acetonitrile. Vibrational analysis has been performed via DFT calculations of the low-spin and high-spin state normal modes of both compounds as well as their respective infrared...

  5. Enhanced lipid isomer separation in human plasma using reversed-phase UPLC with ion-mobility/high-resolution MS detection.

    Science.gov (United States)

    Damen, Carola W N; Isaac, Giorgis; Langridge, James; Hankemeier, Thomas; Vreeken, Rob J

    2014-08-01

    An ultraperformance LC (UPLC) method for the separation of different lipid molecular species and lipid isomers using a stationary phase incorporating charged surface hybrid (CSH) technology is described. The resulting enhanced separation possibilities of the method are demonstrated using standards and human plasma extracts. Lipids were extracted from human plasma samples with the Bligh and Dyer method. Separation of lipids was achieved on a 100 × 2.1 mm inner diameter CSH C18 column using gradient elution with aqueous-acetonitrile-isopropanol mobile phases containing 10 mM ammonium formate/0.1% formic acid buffers at a flow rate of 0.4 ml/min. A UPLC run time of 20 min was routinely used, and a shorter method with a 10 min run time is also described. The method shows extremely stable retention times when human plasma extracts and a variety of biofluids or tissues are analyzed [intra-assay relative standard deviation (RSD) mobility cell. Besides demonstrating the separation for different lipids using the chromatographic method, we demonstrate the use of the ion-mobility MS platform for the structural elucidation of lipids. The method can now be used to elucidate structures of a wide variety of lipids in biological samples of different matrices. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc.

  6. High-spin research with HERA (High Energy-Resolution Array)

    Energy Technology Data Exchange (ETDEWEB)

    Diamond, R.M.

    1987-06-01

    The topic of this report is high spin research with the High Energy Resolution Array (HERA) at Lawrence Berkeley Laboratory. This is a 21 Ge detector system, the first with bismuth germanate (BGO) Compton suppression. The array is described briefly and some of the results obtained during the past year using this detector facility are discussed. Two types of studies are described: observation of superdeformation in the light Nd isotopes, and rotational damping at high spin and excitation energy in the continuum gamma ray spectrum.

  7. Storing quantum information in spins and high-sensitivity ESR.

    Science.gov (United States)

    Morton, John J L; Bertet, Patrice

    2018-02-01

    Quantum information, encoded within the states of quantum systems, represents a novel and rich form of information which has inspired new types of computers and communications systems. Many diverse electron spin systems have been studied with a view to storing quantum information, including molecular radicals, point defects and impurities in inorganic systems, and quantum dots in semiconductor devices. In these systems, spin coherence times can exceed seconds, single spins can be addressed through electrical and optical methods, and new spin systems with advantageous properties continue to be identified. Spin ensembles strongly coupled to microwave resonators can, in principle, be used to store the coherent states of single microwave photons, enabling so-called microwave quantum memories. We discuss key requirements in realising such memories, including considerations for superconducting resonators whose frequency can be tuned onto resonance with the spins. Finally, progress towards microwave quantum memories and other developments in the field of superconducting quantum devices are being used to push the limits of sensitivity of inductively-detected electron spin resonance. The state-of-the-art currently stands at around 65 spins per Hz, with prospects to scale down to even fewer spins. Copyright © 2017. Published by Elsevier Inc.

  8. High-spin states in sup 166 Lu

    Energy Technology Data Exchange (ETDEWEB)

    Hojman, D.; Kreiner, A.J.; Davidson, M.; Davidson, J.; Debray, M.; Cybulska, E.W.; Pascholati, P.; Seale, W.A. (Departamento de Fisica, Comision Nacional de Energia Atomica, 1429 Buenos Aires, Buenos Aires (Argentina) Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires (Argentina) Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil))

    1992-01-01

    High-spin states belonging to {sup 166}Lu have been studied through the {sup 159}Tb({sup 12}C,5{ital n}) fusion-evaporation reaction in the energy range {ital E}({sup 12}C)=75--90 MeV. In-beam and activity singles spectra and {gamma}-{gamma}-{ital t} coincidences have been measured. A completely new level scheme is proposed. Each rotational band is interpreted on the basis of coupling scheme systematics. {ital g}-{ital S} crossing frequencies and alignments have been extracted. {ital B}({ital M}1)/{ital B}({ital E}2) reduced transition probability ratios have been calculated using a semiclassical method and compared to the experimental values.

  9. High-frequency EPR on high-spin transition-metal sites

    NARCIS (Netherlands)

    Mathies, Guinevere

    2012-01-01

    The electronic structure of transition-metal sites can be probed by electron-paramagnetic-resonance (EPR) spectroscopy. The study of high-spin transition-metal sites benefits from EPR spectroscopy at frequencies higher than the standard 9.5 GHz. However, high-frequency EPR is a developing field. In

  10. Control of Spinning Sidebands in High Resolution NMR Spectroscopy

    Science.gov (United States)

    Borer; Maple

    1998-04-01

    The presence of spinning sidebands can severely compromise the detection of low molarity analytes. Spinning sidebands have traditionally been minimized by improving the magnetic field homogeneity and by varying the spinning of the sample in a linear fashion during data acquisition. The effect of the latter is to spread the spinning sideband intensity over a range of frequencies so that the final result is a spinning sideband whose shape reflects the distribution of spinning speeds. We have designed a customized profile of spinner speed variation that optimizes the reduction of spinning sidebands. The customized profile is based on theoretical considerations of how the intensity of sidebands vary with the rate of sample rotation and also compensates for the mechanical design of the spinner mechanism. The result is a unique combination of an exponential increase in gas flow rate to balance the theoretical considerations coupled with a strategically placed rapid change in air flow to annul the sluggish response of the spinning mechanism to acceleration. The resulting sideband shape is a broad, flat, square step in the baseline that is least likely to interfere with low molarity analyte peaks. Copyright 1998 Academic Press.

  11. Complex narrow-line Seyfert 1s : high spin or high inclination?

    OpenAIRE

    Gardner, E.; Done, C.

    2015-01-01

    Complex narrow-line Seyfert 1s (NLS1s), such as 1H 0707−495, differ from simple NLS1s like PG 1244+026 by showing stronger broad spectral features at Fe K and larger amplitude flux variability. These are correlated: the strongest Fe K features are seen during deep dips in the light curves of complex NLS1s. There are two competing explanations for these features, one where a compact X-ray source on the spin axis of a highly spinning black hole approaches the horizon and the consequent strong r...

  12. Interplay between spin polarization and color superconductivity in high density quark matter

    DEFF Research Database (Denmark)

    Tsue, Yasuhiko; da Providência, João; Providência, Constança

    2013-01-01

    Here, it is suggested that a four-point interaction of the tensor type may lead to spin polarization in quark matter at high density. It is found that the two-flavor superconducting phase and the spin polarized phase correspond to distinct local minima of a certain generalized thermodynamical...... potential. It follows that a transition from one to the other phase occurs, passing through true minima with both a spin polarization and a color superconducting gap. It is shown that the quark spin polarized phase is realized at rather high density, while the two-flavor color superconducting phase...

  13. Tunable Dirac points and high spin polarization in ferromagnetic-strain graphene superlattices.

    Science.gov (United States)

    Wu, Qing-Ping; Liu, Zheng-Fang; Chen, Ai-Xi; Xiao, Xian-Bo; Miao, Guo-Xing

    2017-11-07

    Spin-dependent energy bands and transport properties of ferromagnetic-strain graphene superlattices are studied. The high spin polarization appears at the Dirac points due to the presence of spin-dependent Dirac points in the energy band structure. A gap can be induced in the vicinity of Dirac points by strain and the width of the gap is enlarged with increasing strain strength, which is beneficial for enhancing spin polarization. Moreover, a full spin polarization can be achieved at large strain strength. The position and number of the Dirac points corresponding to high spin polarization can be effectively manipulated with barrier width, well width and effective exchange field, which reveals a remarkable tunability on the wavevector filtering behavior.

  14. Assignment of Ferriheme Resonances for High- and Low-Spin Forms of Nitrophorin 3 by H and C NMR Spectroscopy and Comparison to Nitrophorin 2: Heme Pocket Structural Similarities and Differences.

    Science.gov (United States)

    Shokhireva, Tatiana Kh; Berry, Robert E; Zhang, Hongjun; Shokhirev, Nikolai V; Walker, F Ann

    2008-03-03

    Nitrophorin 3 (NP3) is the only one of the four major NO-binding heme proteins found in the saliva of the blood-sucking insect Rhodnius prolixus (also called the Kissing Bug) for which it has not been possible to obtain crystals of diffraction quality for structure determination by X-ray crystallography. Thus we have used NMR spectroscopy, mainly of the hyperfine-shifted ferriheme substituent resonances, to learn about the similarities and differences in the heme pocket and the iron active site of NP3 as compared to NP2, which has previously been well-characterized by both X-ray crystallography and NMR spectroscopy. Only one residue in the heme pocket differs between the two, F27 of NP2 is Y27 for NP3; in both cases this residue is expected to interact strongly with the 2-vinyl side chain of the B heme rotational isomer or the 4-vinyl of the A heme rotational isomer. Both the high-spin (S = 5/2) aquo complex, NP3-H(2)O, and the low-spin (S = 1/2) N-methylimidazole (NMeIm) complex of NP3 have been studied. It is found that the chemical shifts of the protons of both forms are similar to those of the corresponding NP2 complexes, but with minor differences that indicate a slightly different angle for the proximal histidine (H57) ligand plane. The B heme rotational isomer is preferred by both NP3 and NP2 in both spin states, but to a greater extent when phenylalanine is present at position 27 (A:B = 1:8 for NP2, 1:6 for NP3-Y27F, 1:4 for NP3, and 1:3 for NP2-F27Y). Careful analysis of the 5Me and 8Me shifts of the A and B isomers of the two high-spin nitrophorins leads to the conclusion that the heme environment for the two isomers differs in some way that cannot be explained at the present time. The kinetics of deprotonation of the high-spin complexes of NP2 and NP3 are very different, with NP2 giving well-resolved high-spin aquo and "low-spin" hydroxo proton NMR spectra until close to the end of the titration, while NP3 exhibits broadened (1)H NMR spectra indicative

  15. Spin-offs of high energy physics to society

    CERN Document Server

    Amaldi, Ugo

    2000-01-01

    Scientists are more and more frequently asked about the spin-offs of fundamental research. To answer effectively, it is important to organise the multiple aspects of knowledge and technology transfer in a coherent scheme. In this paper the spin-offs of particle physics to other fields of science and to industries are grouped in four streams: usable knowledge, people, methods and technologies. After treating these four items, with examples and suggestions of ways to improve the quality and quantity of the spin-offs, the pathways through which the results and the techniques of fundamental science percolate to society are discussed. (33 refs).

  16. Individual CLA Isomers, c9t11 and t10c12, Prevent Excess Liver Glycogen Storage and Inhibit Lipogenic Genes Expression Induced by High-Fructose Diet in Rats

    Directory of Open Access Journals (Sweden)

    Edyta Maslak

    2015-01-01

    Full Text Available This study assessed the effects of individual conjugated linoleic acid isomers, c9t11-CLA and t10c12-CLA, on nonalcoholic fatty liver disease (NAFLD and systemic endothelial dysfunction in rats fed for four weeks with control or high-fructose diet. The high-fructose diet hampered body weight gain (without influencing food intake, increased liver weight and glycogen storage in hepatocytes, upregulated expression of fatty acid synthase (FAS and stearoyl-CoA desaturase-1 (SCD-1, and increased saturated fatty acid (SFA content in the liver. Both CLA isomers prevented excessive accumulation of glycogen in the liver. Specifically, t10c12-CLA decreased concentration of serum triacylglycerols and LDL + VLDL cholesterol, increased HDL cholesterol, and affected liver lipid content and fatty acid composition by downregulation of liver SCD-1 and FAS expression. In turn, the c9t11-CLA decreased LDL+VLDL cholesterol in the control group and downregulated liver expression of FAS without significant effects on liver weight, lipid content, and fatty acid composition. In summary, feeding rats with a high-fructose diet resulted in increased liver glycogen storage, indicating the induction of gluconeogenesis despite simultaneous upregulation of genes involved in de novo lipogenesis. Although both CLA isomers (c9t11 and t10c12 display hepatoprotective activity, the hypolipemic action of the t10c12-CLA isomer proved to be more pronounced than that of c9t11-CLA.

  17. Isomer shift and magnetic moment of the long-lived 1/2$^{+}$ isomer in $^{79}_{30}$Zn$_{49}$: signature of shape coexistence near $^{78}$Ni

    CERN Document Server

    Yang, X.F.; Xie, L.; Babcock, C.; Billowes, J.; Bissell, M.L.; Blaum, K.; Cheal, B.; Flanagan, K.T.; Garcia Ruiz, R. F.; Gins, W.; Gorges, C.; Grob, L.K.; Heylen, H.; Kaufmann, S.; Kowalska, M.; Kraemer, J.; Malbrunot-Ettenauer, S.; Neugart, R.; Neyens, G.; Nörtershäuser, W.; Papuga, J.; Sánchez, R.; Yordanov, D.T.

    2016-01-01

    Collinear laser spectroscopy has been performed on the $^{79}_{30}$Zn$_{49}$ isotope at ISOLDE-CERN. The existence of a long-lived isomer with a few hundred milliseconds half-life was confirmed, and the nuclear spins and moments of the ground and isomeric states in $^{79}$Zn as well as the isomer shift were measured. From the observed hyperfine structures, spins $I = 9/2$ and $I = 1/2$ are firmly assigned to the ground and isomeric states. The magnetic moment $\\mu$ ($^{79}$Zn) = $-$1.1866(10) $\\mu_{\\rm{N}}$, confirms the spin-parity $9/2^{+}$ with a $\

  18. Anaerobic Degradation of Lindane and Other HCH Isomers

    NARCIS (Netherlands)

    Mehboob, F.; Langenhoff, A.A.M.; Schraa, G.; Stams, A.J.M.

    2013-01-01

    Lindane (¿-HCH) is a pesticide that has mainly been used in agriculture. Lindane and the other HCH isomers are highly chlorinated hydrocarbons. The presence of a large number of electron withdrawing chlorine groups makes some of the HCH isomers rather recalcitrant in oxic environments. Especially

  19. High-spin states of the neutron-rich nucleus sup 1 sup 2 sup 5 Sb

    CERN Document Server

    Liu Zhong; Ma Yin Gjun; Sasaki, Y; Yamada, K; Oshima, H; Yokose, S; Ishizuka, M; Komatsubara, T; Furuno, K

    2002-01-01

    High spin states of sup 1 sup 2 sup 5 Sb have been investigated for the first time by means of in-beam gamma-ray spectroscopy techniques via the sup 1 sup 2 sup 4 Sn( sup 7 Li, alpha 2n) reaction at 32 MeV beam energy. Based on the measurements of gamma-gamma coincidence and gamma-ray anisotropies, a level scheme including 21 new gamma-transitions and 14 new excited levels was established up to 23/2 sup +. Three isomers at 1970, 2110 and 2471 keV levels have been identified and proposed as three-quasiparticle pi g sub 7 sub / sub 2 nu(h sub 1 sub 1 sub / sub 2 s sub 1 sub / sub 2), pi g sub 7 sub / sub 2 nu(h sub 1 sub 1 sub / sub 2 d sub 3 sub / sub 2) and pi g sub 7 sub / sub 2 nu(h sub 1 sub 1 sub / sub 2 sup 2) configurations, respectively. The level structure of sup 1 sup 2 sup 5 Sb is discussed in terms of particle-core coupling

  20. Assignment of Ferriheme Resonances for High- and Low-Spin Forms of Nitrophorin 3 by 1H and 13C NMR Spectroscopy and Comparison to Nitrophorin 2: Heme Pocket Structural Similarities and Differences

    Science.gov (United States)

    Shokhireva, Tatiana Kh.; Berry, Robert E.; Zhang, Hongjun; Shokhirev, Nikolai V.; Walker, F. Ann

    2008-01-01

    Nitrophorin 3 (NP3) is the only one of the four major NO-binding heme proteins found in the saliva of the blood-sucking insect Rhodnius prolixus (also called the Kissing Bug) for which it has not been possible to obtain crystals of diffraction quality for structure determination by X-ray crystallography. Thus we have used NMR spectroscopy, mainly of the hyperfine-shifted ferriheme substituent resonances, to learn about the similarities and differences in the heme pocket and the iron active site of NP3 as compared to NP2, which has previously been well-characterized by both X-ray crystallography and NMR spectroscopy. Only one residue in the heme pocket differs between the two, F27 of NP2 is Y27 for NP3; in both cases this residue is expected to interact strongly with the 2-vinyl side chain of the B heme rotational isomer or the 4-vinyl of the A heme rotational isomer. Both the high-spin (S = 5/2) aquo complex, NP3-H2O, and the low-spin (S = 1/2) N-methylimidazole (NMeIm) complex of NP3 have been studied. It is found that the chemical shifts of the protons of both forms are similar to those of the corresponding NP2 complexes, but with minor differences that indicate a slightly different angle for the proximal histidine (H57) ligand plane. The B heme rotational isomer is preferred by both NP3 and NP2 in both spin states, but to a greater extent when phenylalanine is present at position 27 (A:B = 1:8 for NP2, 1:6 for NP3-Y27F, 1:4 for NP3, and 1:3 for NP2-F27Y). Careful analysis of the 5Me and 8Me shifts of the A and B isomers of the two high-spin nitrophorins leads to the conclusion that the heme environment for the two isomers differs in some way that cannot be explained at the present time. The kinetics of deprotonation of the high-spin complexes of NP2 and NP3 are very different, with NP2 giving well-resolved high-spin aquo and “low-spin” hydroxo proton NMR spectra until close to the end of the titration, while NP3 exhibits broadened 1H NMR spectra indicative

  1. Shape evolution in 76, 78Kr nuclei at high spins in tilted axis ...

    Indian Academy of Sciences (India)

    A two-dimensional tilted axis cranking Hartree–Fock–Bogoliubov (CHFB) calculation is performed for 76Kr and 78Kr nuclei up to high spins = 30 employing a pairing-plus-quadrupole (PPQ) model interaction Hamiltonian. Intricate details of the evolution of single particle structures and shapes as a function of spin have ...

  2. Shape evolution in 76,78Kr nuclei at high spins in tilted axis ...

    Indian Academy of Sciences (India)

    CHFB) calculation is performed for 76Kr and 78Kr nuclei up to high spins J = 30 employing a pairing-plus-quadrupole (PPQ) model interaction Hamiltonian. Intricate details of the evolution of single particle structures and shapes as a function of spin ...

  3. Yield of Radionuclides and Isomers Measured in Fragmentation of the ^{nat}W and ^{186}W (97%) Targets with Protons at 630, 420 and 270 MeV

    CERN Document Server

    Karamian, S A; Chaloun, P; Filossofov, D V; Henzl, V; Henzlova, D; Kalinnikov, V G; Korolev, N A; Lebedev, N A; Novgorodov, A F; Collins, C B; Popescu, I I; Ur, C A

    2004-01-01

    Yields and cross sections of the radioactive nuclide formation have been measured via induced activity gamma-spectra after irradiation of the natural composition W and enriched ^{186)W targets at Dubna synchrocyclotron. Spallation and fission products have been represented among the detected nuclides. The high-spin isomers of Hf and Lu were produced and the isomer-to-ground state ratios could be estimated. The nuclide yields have also been calculated using the LAHET code at 6 values of proton energy in the range from 100 to 800 MeV both for ^{nat)W and for enriched ^{186)W targets. Measured isotope yields are generally in agreement with the calculations, however, the code is incapable to predict the isomer-to-ground state ratios. In experiment, it has been shown that the ^{177m}Lu, ^{178m2}Hf and ^{179m2}Hf high-spin isomers are produced with 2.5 times higher yield in the 97% enriched ^{186)W target as compared to the ^{nat)W target at identical irradiations. This makes significance for the creation of high-a...

  4. Spin Torque Oscillator for High Performance Magnetic Memory

    Directory of Open Access Journals (Sweden)

    Rachid Sbiaa

    2015-06-01

    Full Text Available A study on spin transfer torque switching in a magnetic tunnel junction with perpendicular magnetic anisotropy is presented. The switching current can be strongly reduced under a spin torque oscillator (STO, and its use in addition to the conventional transport in magnetic tunnel junctions (MTJ should be considered. The reduction of the switching current from the parallel state to the antiparallel state is greater than in  the opposite direction, thus minimizing the asymmetry of the resistance versus current in the hysteresis loop. This reduction of both switching current and asymmetry under a spin torque oscillator occurs only during the writing process and does not affect the thermal stability of the free layer.

  5. Application of ultrasound-assisted emulsification microextraction for simultaneous determination of aminophenol isomers in human urine, hair dye, and water samples using high-performance liquid chromatography.

    Science.gov (United States)

    Asghari, Alireza; Fazl-Karimi, Hamidreza; Barfi, Behruz; Rajabi, Maryam; Daneshfar, Ali

    2014-08-01

    Aminophenol isomers (2-, 3-, and 4-aminophenols) are typically classified as industrial pollutants with genotoxic and mutagenic effects due to their easy penetration through the skin and membranes of human, animals, and plants. In the present study, a simple and efficient ultrasound-assisted emulsification microextraction procedure coupled with high-performance liquid chromatography with ultraviolet detector was developed for preconcentration and determination of these compounds in human fluid and environmental water samples. Effective parameters (such as type and volume of extraction solvent, pH and ionic strength of sample, and ultrasonication and centrifuging time) were investigated and optimized. Under optimum conditions (including sample volume: 5 mL; extraction solvent: chloroform, 80 µL; pH: 6.5; without salt addition; ultrasonication: 3.5 min; and centrifuging time: 3 min, 5000 rpm min(-1)), the enrichment factors and limits of detection were ranged from 42 to 51 and 0.028 to 0.112 µg mL(-1), respectively. Once optimized, analytical performance of the method was studied in terms of linearity (0.085-157 µg mL(-1), r (2) > 0.998), accuracy (recovery = 88.6- 101.7%), and precision (repeatability: intraday precision extraction and determination of these compounds in human urine, hair dye, and real water samples. © The Author(s) 2014.

  6. Problems and Progress in Covariant High Spin Description

    Science.gov (United States)

    Kirchbach, Mariana; Banda Guzmán, Víctor Miguel

    2016-10-01

    A universal description of particles with spins j > 1, transforming in (j, 0) ⊕ (0, j), is developed by means of representation specific second order differential wave equations without auxiliary conditions and in covariant bases such as Lorentz tensors for bosons, Lorentz-tensors with Dirac spinor components for fermions, or, within the basis of the more fundamental Weyl- Van-der-Waerden sl(2,C) spinor-tensors. At the root of the method, which is free from the pathologies suffered by the traditional approaches, are projectors constructed from the Casimir invariants of the spin-Lorentz group, and the group of translations in the Minkowski space time.

  7. Lutein and zeaxanthin isomers modulates lipid metabolism and the inflammatory state of retina in obesity-induced high-fat diet rodent model.

    Science.gov (United States)

    Tuzcu, Mehmet; Orhan, Cemal; Muz, Omer Ersin; Sahin, Nurhan; Juturu, Vijaya; Sahin, Kazım

    2017-07-24

    Several studies associated high-fat intakes with a high incidence of age-related macular degeneration (AMD). Lutein and Zeaxanthin isomers (L/Zi) may counteract reactive oxygen species produced by oxidative stress. The present study was conducted to determine the possible effects of L/Zi administration on lipid profile, protein genes associated with oxidative stress and inflammation pathways in the obesity induced by a high-fat diet (HFD) in rodents. Twenty-eight male Wistar rats were allocated into four groups as follows: (i) Control, (ii) Control + L/Zi, (iii) High Fat Diet (HFD), and (iv) HFD+ L/Z. L/Zi was administrated for 8 weeks at a daily dose of 100 mg/kg BW. L/Zi administration significantly reduced insulin and free fatty acid (FFA) levels (P < 0.001) and ameliorated the oxidative damage by reducing malondialdehyde (MDA) concentration and increasing antioxidant enzymes activities of retina induced by HFD. In addition, supplementation decreased the levels of vascular endothelial growth factor (VEGF), inducible nitric oxide synthase (iNOS), nuclear factor-kappa B (NF-κB) and intercellular adhesion molecule-1 (ICAM) (P < 0.001, respectively) and improved nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) gene proteins in retinal tissues (P < 0.001). Rats fed with HFD exhibited increased oxidative stress and upregulation of inflammatory indicators. However, L/Zi supplementation modulates genes involved oxidative stress and inflammation including NF-κB and Nrf2 signaling pathways in the retina which may contribute to ameliorating retinal damage induced by HFD.

  8. Isomer separation of $^{70g}Cu$ and $^{70m}Cu$ with a resonance ionization laser ion source

    CERN Document Server

    Köster, U; Mishin, V I; Weissman, L; Huyse, M; Kruglov, K; Müller, W F; Van Duppen, P; Van Roosbroeck, J; Thirolf, P G; Thomas, H C; Weisshaar, D W; Schulze, W; Borcea, R; La Commara, M; Schatz, H; Schmidt, K; Röttger, S; Huber, G; Sebastian, V; Kratz, K L; Catherall, R; Georg, U; Lettry, Jacques; Oinonen, M; Ravn, H L; Simon, H

    2000-01-01

    Radioactive copper isotopes were ionized with the resonance ionization laser ion source at the on-line isotope separator ISOLDE (CERN). Using the different hyperfine structure in the 3d/sup 10/ 4s /sup 2/S/sub 1/2/-3d/sup 10/ 4p /sup 2/P/sub 1/2//sup 0/ transition the low- and high-spin isomers of /sup 70/Cu were selectively enhanced by tuning the laser wavelength. The light was provided by a narrow-bandwidth dye laser pumped by copper vapor lasers and frequency doubled in a BBO crystal. The ground state to isomeric state intensity ratio could be varied by a factor of 30, allowing to assign gamma transitions unambiguously to the decay of the individual isomers. It is shown that the method can also be used to determine magnetic moments. In a first experiment for the 1/sup +/ ground state of /sup 70/Cu a magnetic moment of (+)1.8(3) mu /sub N/ and for the high-spin isomer of /sup 70/Cu a magnetic moment of (+or-)1.2(3) mu /sub N/ could be deduced. (20 refs).

  9. Analysis of terpenoid aldehydes related to insect herbivory in new germplasm line with a high (+)-to(-)- gossypol isomer ratio

    Science.gov (United States)

    Gossypol is present in cotton plants in two enantiomeric forms, (+)- and (-)-gossypol. The ratios of these enantiomers vary considerably among Gossypium species and between different plant tissues. Cotton seeds are commonly used as animal feed only for ruminants because (-)-gossypol is highly toxi...

  10. High spin injection polarization at an elevated dc bias in tunnel-junction-based lateral spin valves

    Science.gov (United States)

    Wang, X. J.; Zou, H.; Ocola, L. E.; Ji, Y.

    2009-07-01

    Submicron metallic lateral spin valves are fabricated with AlOx tunnel junctions as spin injection and detection barriers. The spin polarization is estimated to be ˜20%, determined by both Hanle effect and variations of device dimensions. The polarization is maintained at a large dc injection current density >2×106 A/cm2. Both the spin polarization and spin diffusion length are weakly temperature dependent.

  11. High-resolution NMR spectroscopy of biological tissues usingprojected Magic Angle Spinning

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Rachel W.; Jachmann, Rebecca C.; Sakellariou, Dimitris; Nielsen, Ulla Gro; Pines, Alexander

    2005-01-27

    High-resolution NMR spectra of materials subject toanisotropic broadening are usually obtained by rotating the sample aboutthe magic angle, which is 54.7 degrees to the static magnetic field. Inprojected Magic Angle Spinning (p-MAS), the sample is spun about twoangles, neither of which is the magic angle. This provides a method ofobtaining isotropic spectra while spinning at shallow angles. The p-MASexperiment may be used in situations where spinning the sample at themagic angle is not possible due to geometric or other constraints,allowing the choice of spinning angle to be determined by factors such asthe shape of the sample, rather than by the spin physics. The applicationof this technique to bovine tissue samples is demonstrated as a proof ofprinciple for future biological or medical applications.

  12. Determination of semi-volatile and particle-associated polycyclic aromatic hydrocarbons in Stockholm air with emphasis on the highly carcinogenic dibenzopyrene isomers

    Science.gov (United States)

    Masala, Silvia; Lim, Hwanmi; Bergvall, Christoffer; Johansson, Christer; Westerholm, Roger

    2016-09-01

    The concentrations of polycyclic aromatic hydrocarbons (PAHs) have been determined in the gaseous phase and in various particulate matter (PM) size fractions at different locations in and outside of Stockholm, Sweden, representative of street level, urban and rural background. The focus has been on the seldom determined but highly carcinogenic dibenzopyrene isomers (DBPs) dibenzo[a,l]pyrene, dibenzo[a,e]pyrene, dibenzo[a,i]pyrene and dibenzo[a,h]pyrene. PAHs with 3 rings were found to be mainly associated with the vapor phase (>90%) whereas PAHs with 5-6 rings were mostly associated with particulate matter (>92%) and the 4-ringed PAHs partitioned between the two phases. PAH abundance was determined to be in the order street level > urban background > rural background with the PM10 street level 2010 mean of benzo[a]pyrene (B[a]P) reaching 0.24 ng/m3, well below the EU annual limit value of 1 ng/m3. In addition, higher PAH concentrations were found in the sub-micron particle fraction (PM1) as compared to the super-micron fraction (PM1-10) with the abundance in PM1 varying between 57 and 86% of the total PAHs. The B[a]P equivalent concentrations derived for DB[a,l]P and total DBPs exceeded 1-2 and 2-4 times, respectively, that of B[a]P at the four sampling sites; therefore underestimation of the cancer risk posed by PAHs in air could be made if the DBPs were not considered in risk assessment using the toxic equivalency approach, whilst the high correlation (p carcinogenic risk associated to PAHs. However, the big difference in concentration ratios of B[a]P and the DBPs between the present study and some literature data calls for further research to evaluate the temporal and spatial invariance of the B[a]P/DBP ratios.

  13. Recent trends in high spin sensitivity magnetic resonance

    Science.gov (United States)

    Blank, Aharon; Twig, Ygal; Ishay, Yakir

    2017-07-01

    new ideas, show how these limiting factors can be mitigated to significantly improve the sensitivity of induction detection. Finally, we outline some directions for the possible applications of high-sensitivity induction detection in the field of electron spin resonance.

  14. High spin states in odd-odd {sup 132}Cs

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Takehito [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Lu, J.; Furuno, K. [and others

    1998-03-01

    Excited states with spin larger than 5 {Dirac_h} were newly established in the {sup 132}Cs nucleus via the {sup 124}Sn({sup 11}B,3n) reaction. Rotational bands built on the {nu}h{sub 11/2} x {pi}d{sub 5/2}, {nu}h{sub 11/2} x {pi}g{sub 7/2} and {nu}h{sub 11/2} x {pi}h{sub 11/2} configurations were observed up to spin I {approx} 16 {Dirac_h}. The {nu}h{sub 11/2} x {pi}h{sub 11/2} band shows inverted signature splitting below I < 14 {Dirac_h}. A dipole band was firstly observed in doubly odd Cs nuclei. (author)

  15. High-spin level structure of the neutron-rich nucleus 91Y

    CERN Document Server

    He, Xiao-Feng; Fang, Yong-De; Liu, Min-Liang; Zhang, Yu-Hu; Wang, Kai-Long; Wang, Jian-Guo; Guo, Song; Qiang, Yun-Hua; Zheng, Yong; Zhang, Ning-Tao; Li, Guang-Shun; Gao, Bing-Shui; Wu, Xiao-Guang; He, Chuang-Ye; Zheng, Yun

    2015-01-01

    High-spin level structure of the neutron-rich nucleus 91Y has been reinvestigated via the 82Se(13C, p3n)91Y reaction. A newly constructed level scheme including several key levels clarifies the uncertainties in the earlier studies. These levels are characterized by the breaking of the Z=38 and N=56 subshell closures, which involves in the spin-isospin dependent central force and tensor force.

  16. X-ray Absorption Spectroscopic Studies of High-Spin Nonheme (Alkylperoxo)iron(III) Intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Shan,X.; Rohde, J.; Koehntop, K.; Zhou, Y.; Bukowski, M.; Costas, M.; Fujisawa, K.; Que, Jr., L.

    2007-01-01

    The reactions of iron(II) complexes [Fe(Tpt-Bu,i-Pr)(OH)] (1a, Tpt-Bu,i-Pr = hydrotris(3-tert-butyl-5-isopropyl-1-pyrazolyl)borate), [Fe(6-Me2BPMCN)(OTf)2] (1b, 6-Me2BPMCN = N,N'-bis((2-methylpyridin-6-yl)methyl)-N,N'-dimethyl-trans-1,2-diaminocyclohexane), and [Fe(L8Py2)(OTf)](OTf) (1c, L8Py2 = 1,5-bis(pyridin-2-ylmethyl)-1,5-diazacyclooctane) with tert-BuOOH give rise to high-spin FeIII-OOR complexes. X-ray absorption spectra (XAS) of these high-spin species show characteristic features, distinct from those of low-spin Fe-OOR complexes. These include (1) an intense 1s {yields} 3d preedge feature, with an area around 20 units, (2) an edge energy, ranging from 7122 to 7126 eV, that is affected by the coordination environment, and (3) a 1.86-1.96 Angstroms Fe-OOR bond, compared to the 1.78 Angstroms Fe-OOR bond in low-spin complexes. These unique features likely arise from a flexible first coordination sphere in those complexes. The difference in Fe-OOR bond length may rationalize differences in reactivity between low-spin and high-spin FeIII-OOR species.

  17. Persistent high-energy spin excitations in iron-pnictide superconductors.

    Science.gov (United States)

    Zhou, Ke-Jin; Huang, Yao-Bo; Monney, Claude; Dai, Xi; Strocov, Vladimir N; Wang, Nan-Lin; Chen, Zhi-Guo; Zhang, Chenglin; Dai, Pengcheng; Patthey, Luc; van den Brink, Jeroen; Ding, Hong; Schmitt, Thorsten

    2013-01-01

    Motivated by the premise that superconductivity in iron-based superconductors is unconventional and mediated by spin fluctuations, an intense research effort has been focused on characterizing the spin-excitation spectrum in the magnetically ordered parent phases of the Fe pnictides and chalcogenides. For these undoped materials, it is well established that the spin-excitation spectrum consists of sharp, highly dispersive magnons. The fate of these high-energy magnetic modes upon sizable doping with holes is hitherto unresolved. Here we demonstrate, using resonant inelastic X-ray scattering, that optimally hole-doped superconducting Ba(0.6)K(0.4)Fe(2)As(2) retains well-defined, dispersive high-energy modes of magnetic origin. These paramagnon modes are softer than, though as intense as, the magnons of undoped antiferromagnetic BaFe(2)As(2). The persistence of spin excitations well into the superconducting phase suggests that the spin fluctuations in Fe-pnictide superconductors originate from a distinctly correlated spin state. This connects Fe pnictides to cuprates, for which, in spite of fundamental electronic structure differences, similar paramagnons are present.

  18. Fabrication of highly aligned fibrous scaffolds for tissue regeneration by centrifugal spinning technology

    Energy Technology Data Exchange (ETDEWEB)

    Loordhuswamy, Amalorpava Mary [Department of Textile Technology, Anna University, Chennai 600025 (India); Krishnaswamy, Venkat Raghavan; Korrapati, Purna Sai [Department of Biomaterials, CSIR-Central Leather Research Institute, Chennai 600020 (India); Thinakaran, Senthilram [Department of Textile Technology, Anna University, Chennai 600025 (India); Rengaswami, Giri Dev Venkateshwarapuram, E-mail: vrgiridev@yahoo.com [Department of Textile Technology, Anna University, Chennai 600025 (India)

    2014-09-01

    Centrifugal spinning (C-Spin) is an emerging technology which uses centrifugal force to produce ultrafine fibers. Being a voltage free technique it can overcome the limitations of electrospinning. Owing to the unique characteristic features such as high surface area to volume ratio, porosity, mechanical strength and fiber alignment, centrifugal spun (C-spun) fibrous mat has a wide range of scope in various biomedical applications. Higher degree of fiber alignment can be effortlessly achieved by the C-Spin process. In order to prove the versatility of C-Spin system with respect to fiber alignment, Polycaprolactone (PCL) and gelatin were spun taking them as model polymers. The morphological analysis revealed that highly aligned ultrafine fibers with smooth surface are achieved by C-Spinning. Hydrophilicity, porosity and mechanical property results confirm that the C-spun mat is more suitable for tissue engineering applications. In vitro and in vivo experiments proved that the scaffolds are biocompatible and can be efficiently used as a wound dressing material. - Highlights: • Highly aligned PCL/gelatin fibrous scaffolds were prepared by C-Spinning system. • Degree of fiber alignment was influenced by the proportion of gelatin in the blends. • Direction of cell growth was parallel to the direction of fiber alignment. • C-Spun matrices can efficiently accelerate faster wound healing.

  19. Spin Seebeck effect and spin Hall magnetoresistance at high temperatures for a Pt/yttrium iron garnet hybrid structure.

    Science.gov (United States)

    Wang, Shuanhu; Zou, Lvkuan; Zhang, Xu; Cai, Jianwang; Wang, Shufang; Shen, Baogen; Sun, Jirong

    2015-11-14

    Based on unique experimental setups, the temperature dependences of the longitudinal spin Seebeck effect (LSSE) and spin Hall magnetoresistance (SMR) of the Pt/yttrium iron garnet (Pt/YIG) hybrid structure are determined in a wide temperature range up to the Curie temperature of YIG. From a theoretical analysis of the experimental relationship between the SMR and temperature, the spin mixing conductance of the Pt/YIG interface is deduced as a function of temperature. Adopting the deduced spin mixing conductance, the temperature dependence of the LSSE is well reproduced based on the magnon spin current theory. Our research sheds new light on the controversy about the theoretical models for the LSSE.

  20. Projected shell model description for nuclear isomers

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Y. [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, Popular Republic (China)

    2008-12-15

    The study of nuclear isomer properties is a current research focus. To describe isomers, we present a method based on the Projected Shell Model. Two kinds of isomers, {kappa}-isomers and shape isomers, are discussed. For the {kappa}-isomer treatment, {kappa}-mixing is properly implemented in the model. It is found however that in order to describe the strong {kappa}-violation more efficiently, it may be necessary to further introduce triaxiality into the shell model basis. To treat shape isomers, a scheme is outlined which allows mixing those configurations belonging to different shapes. (Author)

  1. Spiral spin state in high-temperature copper-oxide superconductors: Evidence from neutron scattering measurements

    DEFF Research Database (Denmark)

    Lindgård, Per-Anker

    2005-01-01

    An effective spiral spin phase ground state provides a new paradigm for the high-temperature superconducting cuprates. It accounts for the recent neutron scattering observations of spin excitations regarding both the energy dispersion and the intensities, including the "universal" rotation by 45...... degrees around the resonance energy E-res. The intensity has a 2D character even in a single twin crystal. The value of E-res is related to the nesting properties of the Fermi surface. The excitations above E-res are shown to be due to in-plane spin fluctuations, a testable difference from the stripe...... model. The form of the exchange interaction function reveals the effects of the Fermi surface, and the unique shape predicts large quantum spin fluctuations in the ground state....

  2. Redox thermodynamics of high-spin and low-spin forms of chlorite dismutases with diverse subunit and oligomeric structures.

    Science.gov (United States)

    Hofbauer, Stefan; Bellei, Marzia; Sündermann, Axel; Pirker, Katharina F; Hagmüller, Andreas; Mlynek, Georg; Kostan, Julius; Daims, Holger; Furtmüller, Paul G; Djinović-Carugo, Kristina; Oostenbrink, Chris; Battistuzzi, Gianantonio; Obinger, Christian

    2012-11-27

    Chlorite dismutases (Clds) are heme b-containing oxidoreductases that convert chlorite to chloride and dioxygen. In this work, the thermodynamics of the one-electron reduction of the ferric high-spin forms and of the six-coordinate low-spin cyanide adducts of the enzymes from Nitrobacter winogradskyi (NwCld) and Candidatus "Nitrospira defluvii" (NdCld) were determined through spectroelectrochemical experiments. These proteins belong to two phylogenetically separated lineages that differ in subunit (21.5 and 26 kDa, respectively) and oligomeric (dimeric and pentameric, respectively) structure but exhibit similar chlorite degradation activity. The E°' values for free and cyanide-bound proteins were determined to be -119 and -397 mV for NwCld and -113 and -404 mV for NdCld, respectively (pH 7.0, 25 °C). Variable-temperature spectroelectrochemical experiments revealed that the oxidized state of both proteins is enthalpically stabilized. Molecular dynamics simulations suggest that changes in the protein structure are negligible, whereas solvent reorganization is mainly responsible for the increase in entropy during the redox reaction. Obtained data are discussed with respect to the known structures of the two Clds and the proposed reaction mechanism.

  3. Devices and process for high-pressure magic angle spinning nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Hoyt, David W.; Sears, Jesse A.; Turcu, Romulus V. F.; Rosso, Kevin M.; Hu, Jian Zhi

    2017-12-05

    A high-pressure magic angle spinning (MAS) rotor is detailed that includes a high-pressure sample cell that maintains high pressures exceeding 150 bar. The sample cell design minimizes pressure losses due to penetration over an extended period of time.

  4. Dispersive high-energy spin excitations in iron pnictide superconductors investigated with RIXS

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Thorsten; Zhou, Kejin; Monney, C.; Strocov, V.N. [Paul Scherrer Institut, Villigen (Switzerland); Huang, Y.B. [Paul Scherrer Institut, Villigen (Switzerland); IOP, CAS, Beijing (China); Brink, J. van den [IFW Dresden (Germany); Ding, H. [IOP, CAS, Beijing (China)

    2012-07-01

    The discovery of iron-based high temperature superconductivity has triggered tremendous research efforts in searching for novel high-T{sub c} superconductors. Unlike cuprates, which have long-range ordered antiferromagnetic Mott insulators as parent compounds, the parent compounds of iron-based superconductors are spin-density wave metals with delocalized electronic structure and more itinerant magnetism. Recent developments of the high-resolution resonant inelastic X-ray scattering (RIXS) technique have enabled investigations of magnetic excitations in cuprates, which show excellent agreement with results from Inelastic Neutron Scattering. In this presentation we demonstrate that RIXS can be used to measure collective magnetic excitations in iron-based superconductors despite their much stronger itinerancy compared to cuprates. The persistence of high-energy spin excitations even in optimally doped pnictide superconductors in a wide range of temperatures strongly suggests a spin-mediated Cooper pairing mechanism as proposed in cuprate superconductors.

  5. Magnetic moment of the fragmentation-aligned 61Fe (9/2(+)) isomer.

    Science.gov (United States)

    Matea, I; Georgiev, G; Daugas, J M; Hass, M; Neyens, G; Astabatyan, R; Baby, L T; Balabanski, D L; Bélier, G; Borremans, D; Goldring, G; Goutte, H; Himpe, P; Lewitowicz, M; Lukyanov, S; Méot, V; Santos, F de Oliveira; Penionzhkevich, Yu E; Roig, O; Sawicka, M

    2004-10-01

    We report on the g factor measurement of an isomer in the neutron-rich (61)(26)Fe (E(*)=861 keV and T(1/2)=239(5) ns). The isomer was produced and spin aligned via a projectile-fragmentation reaction at intermediate energy, the time dependent perturbed angular distribution method being used for the measurement of the g factor. For the first time, due to significant improvements of the experimental technique, an appreciable residual alignment of the nuclear spin ensemble has been observed, allowing a precise determination of its g factor, including the sign: g=-0.229(2). In this way we open the possibility to study moments of very neutron-rich short-lived isomers, not accessible via other production and spin-orientation methods.

  6. Generating highly polarized nuclear spins in solution using dynamic nuclear polarization

    DEFF Research Database (Denmark)

    Wolber, J.; Ellner, F.; Fridlund, B.

    2004-01-01

    and other low-γ nuclei. Subsequent to the DNP process, the solid sample is dissolved rapidly with a warm solvent to create a solution of molecules with highly polarized nuclear spins. Two main applications are proposed: high-resolution liquid state NMR with enhanced sensitivity, and the use...

  7. High resolution x-ray fluorescence spectroscopy - a new technique for site- and spin-selectivity

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin [Univ. of California, Davis, CA (United States). Dept. of Applied Science

    1996-12-01

    X-ray spectroscopy has long been used to elucidate electronic and structural information of molecules. One of the weaknesses of x-ray absorption is its sensitivity to all of the atoms of a particular element in a sample. Through out this thesis, a new technique for enhancing the site- and spin-selectivity of the x-ray absorption has been developed. By high resolution fluorescence detection, the chemical sensitivity of K emission spectra can be used to identify oxidation and spin states; it can also be used to facilitate site-selective X-ray Absorption Near Edge Structure (XANES) and site-selective Extended X-ray Absorption Fine Structure (EXAFS). The spin polarization in K fluorescence could be used to generate spin selective XANES or spin-polarized EXAFS, which provides a new measure of the spin density, or the nature of magnetic neighboring atoms. Finally, dramatic line-sharpening effects by the combination of absorption and emission processes allow observation of structure that is normally unobservable. All these unique characters can enormously simplify a complex x-ray spectrum. Applications of this novel technique have generated information from various transition-metal model compounds to metalloproteins. The absorption and emission spectra by high resolution fluorescence detection are interdependent. The ligand field multiplet model has been used for the analysis of K{alpha} and K{beta} emission spectra. First demonstration on different chemical states of Fe compounds has shown the applicability of site selectivity and spin polarization. Different interatomic distances of the same element in different chemical forms have been detected using site-selective EXAFS.

  8. Electron magnetic resonance data on high-spin Mn(III; S=2) ions in porphyrinic and salen complexes modeled by microscopic spin Hamiltonian approach.

    Science.gov (United States)

    Tadyszak, Krzysztof; Rudowicz, Czesław; Ohta, Hitoshi; Sakurai, Takahiro

    2017-10-01

    The spin Hamiltonian (SH) parameters experimentally determined by EMR (EPR) may be corroborated or otherwise using various theoretical modeling approaches. To this end semiempirical modeling is carried out for high-spin (S=2) manganese (III) 3d 4 ions in complex of tetraphenylporphyrinato manganese (III) chloride (MnTPPCl). This modeling utilizes the microscopic spin Hamiltonians (MSH) approach developed for the 3d 4 and 3d 6 ions with spin S=2 at orthorhombic and tetragonal symmetry sites in crystals, which exhibit an orbital singlet ground state. Calculations of the zero-field splitting (ZFS) parameters and the Zeeman electronic (Ze) factors (g || =g z , g ⊥ =g x =g y ) are carried out for wide ranges of values of the microscopic parameters using the MSH/VBA package. This enables to examine the dependence of the theoretically determined ZFS parameters b k q (in the Stevens notation) and the Zeeman factors g i on the spin-orbit (λ), spin-spin (ρ) coupling constant, and the ligand-field energy levels (Δ i ) within the 5 D multiplet. The results are presented in suitable tables and graphs. The values of λ, ρ, and Δ i best describing Mn(III) ions in MnTPPCl are determined by matching the theoretical second-rank ZFSP b 2 0 (D) parameter and the experimental one. The fourth-rank ZFS parameters (b 4 0 , b 4 4 ) and the ρ (spin-spin)-related contributions, which have been omitted in previous studies, are considered for the first time here and are found important. Semiempirical modeling results are compared with those obtained recently by the density functional theory (DFT) and/or ab initio methods. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Observation of high-spin oblate band structures in Pm141

    Science.gov (United States)

    Gu, L.; Zhu, S. J.; Wang, J. G.; Yeoh, E. Y.; Xiao, Z. G.; Zhang, S. Q.; Meng, J.; Zhang, M.; Liu, Y.; Ding, H. B.; Xu, Q.; Zhu, L. H.; Wu, X. G.; He, C. Y.; Li, G. S.; Wang, L. L.; Zheng, Y.; Zhang, B.

    2011-06-01

    The high-spin states of Pm141 have been investigated through the reaction Te126(F19,4n) at a beam energy of 90 MeV. A previous level scheme has been updated with spins up to 49/2ℏ. Six collective bands at high spins are newly observed. Based on the systematic comparison, one band is proposed as a decoupled band; two bands with strong ΔI=1 M1 transitions inside the bands are suggested as the oblate bands with γ ~-60°; three other bands with large signature splitting have been proposed with the oblate-triaxial deformation with γ~ -90°. The triaxial n-particle-n-hole particle rotor model calculations for one of the oblate bands in Pm141 are in good agreement with the experimental data. The other characteristics for these bands have been discussed.

  10. Complex narrow-line Seyfert 1s: high spin or high inclination?

    Science.gov (United States)

    Gardner, Emma; Done, Chris

    2015-04-01

    Complex narrow-line Seyfert 1s (NLS1s), such as 1H 0707-495, differ from simple NLS1s like PG 1244+026 by showing stronger broad spectral features at Fe K and larger amplitude flux variability. These are correlated: the strongest Fe K features are seen during deep dips in the light curves of complex NLS1s. There are two competing explanations for these features, one where a compact X-ray source on the spin axis of a highly spinning black hole approaches the horizon and the consequent strong relativistic effects focus the intrinsic flux on to the inner edge of a thin disc, giving a dim, reflection-dominated spectrum. The other is that the deep dips are caused by complex absorption by clumps close to the hard X-ray source. The reflection-dominated model is able to reproduce the very short 30 s soft lag from reverberation seen in the complex NLS1 1H 0707-495. However, it does not explain the characteristic switch to hard lags on longer time-scales. Instead, a full model of propagating fluctuations coupled to reverberation can explain the switch in the simple NLS1 PG 1244+026 using a low spin black hole. However, PG 1244+026 has a longer reverberation lag of ˜200 s. Here we extend the successful propagation-reverberation model for the simple NLS1 PG 1244+026 to include the effect of absorption from clumps in a turbulent region above the disc. The resulting occultations of the inner accretion flow can introduce additional hard lags when relativistic effects are taken into account. This dilutes the soft lag from reverberation and shifts it to higher frequencies, making a smooth transition between the 200 s lags seen in simple NLS1s to the 30 s lags in complex NLS1s. These two classes of NLS1 could then be determined by inclination angle with respect to a clumpy, probably turbulent, failed wind structure on the disc.

  11. Quantification of levoglucosan and its isomers by High Performance Liquid Chromatography - Electrospray Ionization tandem Mass Spectrometry and its applications to atmospheric and soil samples

    Science.gov (United States)

    Piot, C.; Jaffrezo, J.-L.; Cozic, J.; Pissot, N.; El Haddad, I.; Marchand, N.; Besombes, J.-L.

    2012-01-01

    The determination of atmospheric concentrations of levoglucosan and its two isomers, unambiguous tracers of biomass burning emissions, became even more important with the development of wood as renewable energy for domestic heating. Many researches demonstrated the increase during recent years of atmospheric particulate matter load due to domestic biomass combustion in developed countries. Analysis of biomass burning tracers is traditionally performed with Gas Chromatography-Mass Spectrometry (GC-MS) technique after derivatization and requires an organic solvent extraction. A simpler and faster technique using Liquid Chromatography - Electrospray Ionisation - tandem Mass Spectrometry (LC-ESI-MS/MS) was optimized for the analysis of levoglucosan, mannosan and galactosan isomers after an aqueous extraction. This technique allows a good separation between the three compounds in a very reduced time (runtime ~5 min). LOD and LOQ of this method are 30 μg l-1 and 100 μg l-1 respectively, allowing the use of filters from low-volume sampler (as commonly used in routine campaigns). A comparison of simultaneous levoglucosan measurements by GC-MS and LC-ESI-MS/MS for about 50 samples coming from different types of sampling sites and seasons was realized and shows very good agreement between the two methods. Therefore LC-ESI-MS/MS method can be used as an alternative to GC-MS particularly for measurement campaigns in routine where analysis time is important and detection limit is reduced. This paper shows that this method is also applicable to other environmental sample types like soil.

  12. Unexpected Spin-Crossover and a Low-Pressure Phase Change in an Iron(II)/Dipyrazolylpyridine Complex Exhibiting a High-Spin Jahn-Teller Distortion.

    Science.gov (United States)

    Kershaw Cook, Laurence J; Thorp-Greenwood, Flora L; Comyn, Tim P; Cespedes, Oscar; Chastanet, Guillaume; Halcrow, Malcolm A

    2015-07-06

    The synthesis of 4-methyl-2,6-di(pyrazol-1-yl)pyridine (L) and four salts of [FeL2]X2 (X(-) = BF4(-), 1; X(-) = ClO4(-), 2; X(-) = PF6(-), 3; X(-) = CF3SO3(-), 4) are reported. Powder samples of 1 and 2 both exhibit abrupt, hysteretic spin-state transitions on cooling, with T1/2↓ = 204 and T1/2↑ = 209 K (1), and T1/2↓ = 175 and T1/2↑ = 193 K (2). The 18 K thermal hysteresis loop for 2 is unusually wide for a complex of this type. Single crystal structures of 2 show it to exhibit a Jahn-Teller-distorted six-coordinate geometry in its high-spin state, which would normally inhibit spin-crossover. Bulk samples of 1 and 2 are isostructural by X-ray powder diffraction, and undergo a crystallographic phase change during their spin-transitions. At temperatures below T1/2, exposing both compounds to 10(-5) Torr pressure inside the powder diffractometer causes a reversible transformation back to the high-temperature crystal phase. Consideration of thermodynamic data implies this cannot be accompanied by a low → high spin-state change, however. Both compounds also exhibit the LIESST effect, with 2 exhibiting an unusually high T(LIESST) of 112 K. The salts 3 and 4 are respectively high-spin and low-spin between 3 and 300 K, with crystalline 3 exhibiting a more pronounced version of the same Jahn-Teller distortion.

  13. X-Ray Absorption Spectroscopic Studies of High-Spin Nonheme (Alkylperoxo)Iron(III) Intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Shan, X.; Rohde, J.-U.; Koehntop, K.D.; Zhou, Y.; Bukowski, M.R.; Costas, M.; Fujisawa, K.; Que, L.; Jr.

    2009-06-04

    The reactions of iron(II) complexes [Fe(Tp{sup t-Bu,i-Pr})(OH)] (1a, Tp{sup t-Bu,i-Pr} = hydrotris(3-tert-butyl-5-isopropyl-1-pyrazolyl)borate), [Fe(6-Me{sub 2}BPMCN)(OTf){sub 2}] (1b, 6-Me{sub 2}BPMCN = N,N'-bis((2-methylpyridin-6-yl)methyl)-N,N'-dimethyl-trans-1,2-diaminocyclohexane), and [Fe(L{sup 8}Py{sub 2})(OTf)](OTf) (1c, L{sup 8}Py{sub 2} = 1,5-bis(pyridin-2-ylmethyl)-1,5-diazacyclooctane) with tert-BuOOH give rise to high-spin Fe{sup III}-OOR complexes. X-ray absorption spectra (XAS) of these high-spin species show characteristic features, distinct from those of low-spin Fe-OOR complexes (Rohde, J.-U.; et al. J. Am. Chem. Soc. 2004, 126, 16750--16761). These include (1) an intense 1s {yields} 3d preedge feature, with an area around 20 units, (2) an edge energy, ranging from 7122 to 7126 eV, that is affected by the coordination environment, and (3) a 1.86--1.96 {angstrom} Fe-OOR bond, compared to the 1.78 {angstrom} Fe-OOR bond in low-spin complexes. These unique features likely arise from a flexible first coordination sphere in those complexes. The difference in Fe-OOR bond length may rationalize differences in reactivity between low-spin and high-spin Fe{sup III}-OOR species.

  14. Universality, maximum radiation, and absorption in high-energy collisions of black holes with spin.

    Science.gov (United States)

    Sperhake, Ulrich; Berti, Emanuele; Cardoso, Vitor; Pretorius, Frans

    2013-07-26

    We explore the impact of black hole spins on the dynamics of high-energy black hole collisions. We report results from numerical simulations with γ factors up to 2.49 and dimensionless spin parameter χ=+0.85, +0.6, 0, -0.6, -0.85. We find that the scattering threshold becomes independent of spin at large center-of-mass energies, confirming previous conjectures that structure does not matter in ultrarelativistic collisions. It has further been argued that in this limit all of the kinetic energy of the system may be radiated by fine tuning the impact parameter to threshold. On the contrary, we find that only about 60% of the kinetic energy is radiated for γ=2.49. By monitoring apparent horizons before and after scattering events we show that the "missing energy" is absorbed by the individual black holes in the encounter, and moreover the individual black-hole spins change significantly. We support this conclusion with perturbative calculations. An extrapolation of our results to the limit γ→∞ suggests that about half of the center-of-mass energy of the system can be emitted in gravitational radiation, while the rest must be converted into rest-mass and spin energy.

  15. Spin-polarized high-energy scattering of charged leptons on nucleons

    Energy Technology Data Exchange (ETDEWEB)

    Burkardt, M. [New Mexico State Univ., Las Cruces, NM (United States). Dept. of Physics; Miller, C.A. [TRIUMF, Vancouver, BC (Canada); Nowak, W.D. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2009-08-15

    The proton is a composite object with spin one-half, understood to contain highly relativistic spin one-half quarks exchanging spin-one gluons, each possibly with significant orbital angular momenta. While their fundamental interactions are well described by Quantum ChromoDynamics (QCD), our standard theory of the strong interaction, nonperturbative calculations of the internal structure of the proton based directly on QCD are beginning to provide reliable results. Most of our present knowledge of the structure of the proton is based on experimental measurements interpreted within the rich framework of QCD. An area presently attracting intense interest, both experimental and theoretical, is the relationship between the spin of the proton and the spins and orbital angular momenta of its constituents. While remarkable progress has been made, especially in the last decade, the discovery and investigation of new concepts have revealed that much more remains to be learned. This progress is reviewed and an outlook for the future is offered. (orig.)

  16. Physical limitations to efficient high-speed spin-torque switching in magnetic tunnel junctions

    Science.gov (United States)

    Heindl, R.; Rippard, W. H.; Russek, S. E.; Kos, A. B.

    2011-02-01

    We have investigated the physical limitations to efficient high-speed spin-torque switching by means of write error rates both experimentally as well as through macrospin simulations. The spin-torque-induced write operations were performed on in-plane MgO magnetic tunnel junctions. The write error rates were determined from up to 106 switching events as a function of pulse amplitude and duration (5 to 100 ns) for devices with different thermal stability factors. Both experiments and simulations show qualitatively similar results. In particular, the write error rates as a function of pulse voltage amplitude increase at higher rates for pulse durations below ≈50 ns. Simulations show that the write error rates can be reduced only to some extent by the use of materials with perpendicular anisotropy and reduced damping, whereas noncollinear orientation of the spin current polarization and the magnetic easy axis increases the write error rates. The cause for the write error rates is related to the underlying physics of spin-torque switching and the occurrence of the stagnation point on the magnetization switching trajectory where the spin-torque disappears and the device loses the energy needed to switch. The stagnation point can be accessed either during the initial magnetization distribution or by thermal diffusion during the switching process.

  17. Highly mobile gapless excitations in a two-dimensional candidate quantum spin liquid.

    Science.gov (United States)

    Yamashita, Minoru; Nakata, Norihito; Senshu, Yoshinori; Nagata, Masaki; Yamamoto, Hiroshi M; Kato, Reizo; Shibauchi, Takasada; Matsuda, Yuji

    2010-06-04

    The nature of quantum spin liquids, a novel state of matter where strong quantum fluctuations destroy the long-range magnetic order even at zero temperature, is a long-standing issue in physics. We measured the low-temperature thermal conductivity of the recently discovered quantum spin liquid candidate, the organic insulator EtMe3Sb[Pd(dmit)2]2. A sizable linear temperature dependence term is clearly resolved in the zero-temperature limit, indicating the presence of gapless excitations with an extremely long mean free path, analogous to excitations near the Fermi surface in pure metals. Its magnetic field dependence suggests a concomitant appearance of spin-gap-like excitations at low temperatures. These findings expose a highly unusual dichotomy that characterizes the low-energy physics of this quantum system.

  18. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP CIRCUM-PAN-PACIFIC RIKEN SYMPOSIUM ON HIGH ENERGY SPIN PHYSICS, VOLUME 25

    Energy Technology Data Exchange (ETDEWEB)

    KUMANO,S.; SHIBATA,T.A.; YAZAKI,K.

    2000-06-28

    The Circum-Pan-Pacific Riken Symposium on High Energy Spin Physics was held at Oukouchi Memorial Hall in Riken from November 3 through 6, 1999. It was held as a joint meeting of the 2nd Circum-Pan-Pacific Symposium on High Energy Spin Physics and the 3rd of the series of Riken Symposia related to the RHIC-SPIN. The 1st Circum-Pan-Pacific Symposium on High Energy Spin Physics was held at Kobe in 1996 and the RHIC-SPIN Riken Symposia had been held every two years since 1995. As Prof. Ozaki mentioned in his talk at the beginning of this meeting, the RHIC was ready for the first beam, physics experiments scheduled in 2000, and the RHIC-SPIN would start in 2001. It was therefore considered to be very timely for the researchers in the field of high energy spin physics to get together, clarifying the present status of the field and discussing interesting and important topics as well as experimental subjects to be pursued. It is especially important for the success of the RHIC-SPIN project that the researchers in the neighboring countries surrounding the Pacific are actively involved in it. This is why the above two series were joined in this. symposium. The subjects discussed in the symposium include: Hard processes probing spin-structure functions, polarization mechanisms in high energy reactions, lattice studies of polarized structure functions, theoretical models for the nucleon and its spin structure, RHIC and RHIC-SPIN projects, results and future projects of existing experimental facilities. Totally 73 scientists participated in the symposium, 27 from abroad and 46 from Japan. it consisted of 13 main sessions, with 33 invited and contributed talks, and 4 discussion sessions covering recent experimental and theoretical developments and important topics in high energy spin physics and closely related fields.

  19. Effect of high-frequency excitation on natural frequencies of spinning discs

    DEFF Research Database (Denmark)

    Hansen, Morten Hartvig

    2000-01-01

    The effect of high-frequency, non-resonant parametric excitation on the low-frequency response of spinning discs is considered. The parametric excitation is obtained through a non-constant rotation speed, where the frequency of the pulsating overlay is much higher than the lowest natural frequenc...

  20. Spin polarization versus color–flavor locking in high-density quark matter

    DEFF Research Database (Denmark)

    Tsue, Yasuhiko; da Providência, João; Providência, Constança

    2015-01-01

    It is shown that spin polarization with respect to each flavor in three-flavor quark matter occurs instead of color–flavor locking at high baryon density by using the Nambu–Jona-Lasinio model with four-point tensor-type interaction. Also, it is indicated that the order of phase transition between...

  1. Ill-defined block-spin transformations at arbitrarily high temperatures

    NARCIS (Netherlands)

    Enter, Aernout C.D. van

    Examples are presented of block-spin transformations which map the Gibbs measures of the Ising model in two or more dimensions at temperature intervals extending to arbitrarily high temperatures onto non-Gibbsian measures. In this way we provide the first example of this kind of pathology for very

  2. High-dimensional quantum state transfer through a quantum spin chain

    Science.gov (United States)

    Qin, Wei; Wang, Chuan; Long, Gui Lu

    2013-01-01

    In this paper, we investigate a high-dimensional quantum state transfer protocol. An arbitrary unknown high-dimensional state can be transferred with high fidelity between two remote registers through an XX coupling spin chain of arbitrary length. The evolution of the state transfer is determined by the natural dynamics of the chain without external modulation and coupling strength engineering. As a consequence, entanglement distribution with a high efficiency can be achieved. Also the strong field and high spin quantum number can partly counteract the effect of finite temperature to ensure the high fidelity of the protocol when the quantum data bus is in the thermal equilibrium state under an external magnetic field.

  3. Quantification of levoglucosan and its isomers by High Performance Liquid Chromatography – Electrospray Ionization tandem Mass Spectrometry and its applications to atmospheric and soil samples

    Directory of Open Access Journals (Sweden)

    N. Marchand

    2012-01-01

    Full Text Available The determination of atmospheric concentrations of levoglucosan and its two isomers, unambiguous tracers of biomass burning emissions, became even more important with the development of wood as renewable energy for domestic heating. Many researches demonstrated the increase during recent years of atmospheric particulate matter load due to domestic biomass combustion in developed countries. Analysis of biomass burning tracers is traditionally performed with Gas Chromatography-Mass Spectrometry (GC-MS technique after derivatization and requires an organic solvent extraction. A simpler and faster technique using Liquid Chromatography – Electrospray Ionisation – tandem Mass Spectrometry (LC-ESI-MS/MS was optimized for the analysis of levoglucosan, mannosan and galactosan isomers after an aqueous extraction. This technique allows a good separation between the three compounds in a very reduced time (runtime ~5 min. LOD and LOQ of this method are 30 μg l−1 and 100 μg l−1 respectively, allowing the use of filters from low-volume sampler (as commonly used in routine campaigns. A comparison of simultaneous levoglucosan measurements by GC-MS and LC-ESI-MS/MS for about 50 samples coming from different types of sampling sites and seasons was realized and shows very good agreement between the two methods. Therefore LC-ESI-MS/MS method can be used as an alternative to GC-MS particularly for measurement campaigns in routine where analysis time is important and detection limit is reduced. This paper shows that this method is also applicable to other environmental sample types like soil.

  4. Perpendicular spin transfer torque magnetic random access memories with high spin torque efficiency and thermal stability for embedded applications (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Luc, E-mail: luc.thomas@headway.com; Jan, Guenole; Zhu, Jian; Liu, Huanlong; Lee, Yuan-Jen; Le, Son; Tong, Ru-Ying; Pi, Keyu; Wang, Yu-Jen; Shen, Dongna; He, Renren; Haq, Jesmin; Teng, Jeffrey; Lam, Vinh; Huang, Kenlin; Zhong, Tom; Torng, Terry; Wang, Po-Kang [TDK-Headway Technologies, Inc., Milpitas, California 95035 (United States)

    2014-05-07

    Magnetic random access memories based on the spin transfer torque phenomenon (STT-MRAMs) have become one of the leading candidates for next generation memory applications. Among the many attractive features of this technology are its potential for high speed and endurance, read signal margin, low power consumption, scalability, and non-volatility. In this paper, we discuss our recent results on perpendicular STT-MRAM stack designs that show STT efficiency higher than 5 k{sub B}T/μA, energy barriers higher than 100 k{sub B}T at room temperature for sub-40 nm diameter devices, and tunnel magnetoresistance higher than 150%. We use both single device data and results from 8 Mb array to demonstrate data retention sufficient for automotive applications. Moreover, we also demonstrate for the first time thermal stability up to 400 °C exceeding the requirement of Si CMOS back-end processing, thus opening the realm of non-volatile embedded memory to STT-MRAM technology.

  5. Environmentally friendly and highly productive bi-component melt spinning of thermoregulated smart polymer fibres with high latent heat capacity

    Directory of Open Access Journals (Sweden)

    Ch. Cherif

    2018-03-01

    Full Text Available A stable and reproducible bi-component melt spinning process on an industrial scale incorporating Phase Change Material (PCM into textile fibres has been successfully developed and carried out using a melt spinning machine. The key factor for a successful bi-component melt spinning process is that a deep insight into the thermal and rheological behaviour of PCM using Difference Scanning Calorimetry (DSC, Thermogravimetric Analysis (TGA, and an oscillatory rheological investigation. PCM is very sensitive to the temperature and residence time of the melt spinning process. It is found that the optimal process temperature of PCM is 210 °C. The textile-physical properties and the morphology of the melt spun and further drawn bi-component core and sheath fibres (bico fibres were investigated and interpreted. The heat capacities of PCM incorporated in bico fibres were also determined by means of DSC. The melt spun bico fibres integrating PCM provide a high latent heat of up to 22 J/g, which is three times higher than that of state-of-the-art fibres, which were also obtained using the melt spinning process. Therefore, they have the potential to be used as smart polymer fibres for textile and other technical applications.

  6. Endohedral Metallofullerene as Molecular High Spin Qubit: Diverse Rabi Cycles in Gd2@C79N.

    Science.gov (United States)

    Hu, Ziqi; Dong, Bo-Wei; Liu, Zheng; Liu, Jun-Jie; Su, Jie; Yu, Changcheng; Xiong, Jin; Shi, Di-Er; Wang, Yuanyuan; Wang, Bing-Wu; Ardavan, Arzhang; Shi, Zujin; Jiang, Shang-Da; Gao, Song

    2018-01-24

    An anisotropic high-spin qubit with long coherence time could scale the quantum system up. It has been proposed that Grover's algorithm can be implemented in such systems. Dimetallic aza[80]fullerenes M 2 @C 79 N (M = Y or Gd) possess an unpaired electron located between two metal ions, offering an opportunity to manipulate spin(s) protected in the cage for quantum information processing. Herein, we report the crystallographic determination of Gd 2 @C 79 N for the first time. This molecular magnet with a collective high-spin ground state (S = 15/2) generated by strong magnetic coupling (J Gd-Rad = 350 ± 20 cm -1 ) has been unambiguously validated by magnetic susceptibility experiments. Gd 2 @C 79 N has quantum coherence and diverse Rabi cycles, allowing arbitrary superposition state manipulation between each adjacent level. The phase memory time reaches 5 μs at 5 K by dynamic decoupling. This molecule fulfills the requirements of Grover's searching algorithm proposed by Leuenberger and Loss.

  7. A rapid method for the determination of perfluoroalkyl substances including structural isomers of perfluorooctane sulfonic acid in human serum using 96-well plates and column-switching ultra-high performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Salihovic, Samira; Kärrman, Anna; Lindström, Gunilla; Lind, P Monica; Lind, Lars; van Bavel, Bert

    2013-08-30

    To facilitate high-throughput analysis suitable for large epidemiological studies we developed an automated column-switching ultra-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for determination of perfluorocarboxylic acids (PFCAs; C5, C6, C7, C8, C9, C10, C11, C12, and C13), perfluoroalkyl sulfonic acids (PFSAs; C4, C6, C8, and C10), perfluorooctane sulfonamide (PFOSA), and five groups of structural perfluorooctane sulfonic acid (PFOS) isomers in human serum or plasma. The analytical procedure involves rapid protein precipitation using 96-well plates followed by an automated sample clean-up using an on-line trap column removing many potentially interfering sample components while through the mobile phase gradient the target analytes are eluted onto the analytical column for further separation and subsequent mass detection. The method was linear (R(2)determination of perfluoroalkyl substances including structural PFOS isomers in human plasma from an epidemiological study. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Entanglement and magnetism in high-spin graphene nanodisks

    Science.gov (United States)

    Hagymási, I.; Legeza, Ö.

    2018-01-01

    We investigate the ground-state properties of triangular graphene nanoflakes with zigzag edge configurations. The description of zero-dimensional nanostructures requires accurate many-body techniques since the widely used density-functional theory with local density approximation or Hartree-Fock methods cannot handle the strong quantum fluctuations. Applying the unbiased density-matrix renormalization group algorithm we calculate the magnetization and entanglement patterns with high accuracy for different interaction strengths and compare them to the mean-field results. With the help of quantum information analysis and subsystem density matrices we reveal that the edges are strongly entangled with each other. We also address the effect of electron and hole doping and demonstrate that the magnetic properties of triangular nanoflakes can be controlled by an electric field, which reveals features of flat-band ferromagnetism. This may open up new avenues in graphene based spintronics.

  9. Spin conversion of cytochrome b559 in photosystem II induced by exogenous high potential quinone

    Science.gov (United States)

    Kropacheva, Tatyana N.; Feikema, W. Onno; Mamedov, Fikret; Feyziyev, Yashar; Styring, Stenbjorn; Hoff, Arnold J.

    2003-11-01

    The spin-state of cytochrome b559 (Cyt b559) was studied in photosystem II (PSII) membrane fragments by low-temperature EPR spectroscopy. Treatment of the membranes with 2,3-dichloro-5,6-dicyano- p-benzoquinone (DDQ) converts the native low-spin (LS) form of Cyt b559 to the high-spin (HS) form characterized with the g= 6.19 and g= 5.95 split signal. The HS Cyt b559 was pH dependent with the amplitude increasing toward more acidic pH values (pH 5.5-8.5). The HS state was not photochemically active upon 77 and 200 K continuous illumination under our conditions and was characterized by a low reduction potential (⩽0 V). It was also demonstrated that DDQ treatment damages the oxygen evolving complex, leading to inhibition of oxygen evolution, decrease of the S 2-state EPR multiline signal and release of Mn 2+. In parallel, studies of model systems containing iron(III) protoporphyrin IX chloride (Fe IIIPor), which is a good model compound for the Cyt b559 prosthetic group, were performed by using optical and EPR spectroscopy. The interaction of Fe IIIPor with imidazole (Im) in weakly polar solvent results in formation of bis-imidazole coordinated heme iron (Fe IIIPor Im 2) which mimic the bis-histidine axial ligation of Cyt b559. The reaction of DDQ with the LS Fe IIIPor Im 2 complex leads to its transformation into the HS state ( g⊥=5.95, g∥=2.00). It was shown that the spin conversion occurs due to the donor-acceptor interaction of coordinated imidazole with this high-potential quinone causing the displacement of imidazole from the axial position. The similar mechanism of DDQ-induced spin change is assumed to be valid for the native membrane Cyt b559 in PSII centers.

  10. Observation of high-spin bands with large moments of inertia in 124Xe

    Science.gov (United States)

    Nag, Somnath; Singh, A. K.; Hagemann, G. B.; Sletten, G.; Herskind, B.; Døssing, T.; Ragnarsson, I.; Hübel, H.; Bürger, A.; Chmel, S.; Wilson, A. N.; Rogers, J.; Carpenter, M. P.; Janssens, R. V. F.; Khoo, T. L.; Kondev, F. G.; Lauritsen, T.; Zhu, S.; Korichi, A.; Stefanova, E. A.; Fallon, P.; Nyakó, B. M.; Timár, J.; Juhász, K.

    2016-09-01

    High-spin states in 124Xe have been populated using the 80Se(48Ca,4 n ) reaction at a beam energy of 207 MeV and high-multiplicity, γ -ray coincidence events were measured using the Gammasphere spectrometer. Six high-spin bands with large moments of inertia, similar to those observed in neighboring nuclei, have been observed. The experimental results are compared with calculations within the framework of the cranked Nilsson-Strutinsky model. It is suggested that the configurations of the bands involve excitations of protons across the Z =50 shell gap coupled to neutrons within the N =50 -82 shell or excited across the N =82 shell closure.

  11. Detection and characterization of twenty-eight isomers of fumonisin B1 (FB1) mycotoxin in a solid rice culture infected with Fusarium verticillioides by reversed-phase high-performance liquid chromatography/electrospray ionization time-of-flight and ion trap mass spectrometry.

    Science.gov (United States)

    Bartók, Tibor; Tölgyesi, László; Szekeres, András; Varga, Mónika; Bartha, Richárd; Szécsi, Arpád; Bartók, Mihály; Mesterházy, Akos

    2010-01-01

    Fumonisin mycotoxins which are hazardous to humans and animals were produced in a Fusarium verticillioides-infected solid rice culture. To decrease the possibility of the formation of artifacts, the fumonisins were analysed by reversed-phase high-performance liquid chromatography/electrospray ionization time-of-flight (RP-HPLC/ESI-TOFMS) and ion trap mass spectrometry (RP-HPLC/ESI-ITMS) immediately after the extraction of the culture material, without any further sample clean-up. The fumonisin isomers were separated by using a flat gradient on a special, high-coverage C(18), narrow-bore HPLC column (YMC-Pack J'sphere ODS H80) suggested for the separation of structural isomers by the manufacturer. Exact mass measurements (TOFMS) of the protonated molecules and extraction of the ion chromatogram corresponding to the empirical formula (C(34)H(59)NO(15)) of FB(1) toxins led to the identification of 29 peaks and shoulders, including those of FB(1). The FB(1) toxin and 28 of its isomers were also detected by ITMS after separation with RP-HPLC. The characteristic m/z values of the product ions, including the backbones obtained by ITMS(2), undoubtedly indicated the structures of the FB(1) isomers for 28 peaks and shoulders. In the MS(2) spectra of the protonated molecules of the FB(1) isomers, with some exceptions, 15 characteristic product ions including the hydrocarbon backbone at m/z 299 were observed. The abundance ratio of the cation at m/z 299 ranged up to 5.8%. The relative quantities of the isomers found in the sample extract were expressed as percentages of the FB(1) content (0.001-0.579%). The total amount of the 28 FB(1) isomers was 2.803% of the quantity of FB(1) that is important from the aspect of food and feed safety. Copyright 2009 John Wiley & Sons, Ltd.

  12. Nuclear size isomers

    Directory of Open Access Journals (Sweden)

    Ogloblin Alexey

    2016-01-01

    Full Text Available Developing of methods of measuring the radii of nuclei in their highly excited states led to observation of those with dimensions enhanced and, probably, diminished in comparison with the corresponding ground states. Experimental data including very recent ones demonstrating that such “size isomers” belong to two groups: excited states having neutron halos (in 13C, 11Be and 9Be and some specific cluster states (in 12C, 13C and 11B, are discussed.

  13. Atomic spectroscopy studies of short-lived isotopes and nuclear isomer separation with the ISOLDE RILIS

    CERN Document Server

    Fedosseev, V; Weissman, L; Mishin, V I; Federov, D V; Seliverstov, D M; Horn, R; Huber, G; Lassen, J; Wendt, K

    2003-01-01

    The Resonance Ionization Laser Ion Source (RILIS) at the ISOLDE on-line isotope separator is based on the selective excitation of atomic transitions by tunable laser radiation. Ion beams of isotopes of 20 elements have been produced using the RILIS setup. Together with the mass separator and a particle detection system it represents a tool for high-sensitive laser spectroscopy of short-lived isotopes. By applying narrow-bandwidth lasers for the RILIS one can study isotope shifts (IS) and hyperfine structure (HFS) of atomic optical transitions. Such measurements are capable of providing data on nuclear charge radii, spins and magnetic moments of exotic nuclides far from stability. Although the Doppler broadening of the optical absorption lines limits the resolution of the technique, the accuracy of the HFS measurements examined in experiments with stable Tl isotopes approaches a value of 100 MHz. Due to the hyperfine splitting of atomic lines the RILIS gives an opportunity to separate nuclear isomers. Isomer s...

  14. Nuclear spectroscopy of very proton rich nuclei through HI induced reactions; the 14s high spin isomer in /sup 95/Pd

    CERN Document Server

    Nolte, E; Geier, R; Gui, S Z; Heim, U; Hick, H; Komninos, P; Korschinek, G; Kubik, P; Morinaga, H; Schollmeier, W

    1981-01-01

    /sup 40/Ca, /sup 58/Ni and /sup 60/Ni beams from the Munich tandem and the Munich heavy ion postaccelerator have been used to produce very proton rich nuclei in the N=50 N=82 regions. The residual nuclei have been studied with the help of gamma and particle spectroscopy. The level schemes of /sup 95/Rh, /sup 146/Dy and /sup 150/Er and the beta -decay schemes, /sup 95/Pd/sup m/ to /sup 95/Rh, /sup 144/Tb to /sup 144/Gd, /sup 146/Ho to /sup 146/Dy to /sup 146/Tb to /sup 146/Gd, /sup 148/Er to /sup 148/Ho to /sup 148/Dy and /sup 150/Tm to /sup 150/Er to /sup 150/Dy have been investigated. beta delayed proton emission from a J/sup pi / approximately=21/sup +/ isomeric state in /sup 95/Pd has been observed. (12 refs).

  15. High frequency magnetic eigen excitations in a spin valve submitted to CPP DC current

    Energy Technology Data Exchange (ETDEWEB)

    Mistral, Q. [Institut d' Electronique Fondamentale, CNRS UMR 8622, Bat 220, Universite Paris-Sud, Centre d' Orsay, F91405 Orsay Cedex (France)]. E-mail: mistral@ief.u-psud.fr; Deac, A. [SPINTEC, URA CEA/CNRS, CEA Grenoble/DRFMC, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Grollier, J. [Institut d' Electronique Fondamentale, CNRS UMR 8622, Bat 220, Universite Paris-Sud, Centre d' Orsay, F91405 Orsay Cedex (France); Redon, O. [SPINTEC, URA CEA/CNRS, CEA Grenoble/DRFMC, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Liu, Y. [Headway, 678 Hillview Dr., Milpitas, CA 95035 (United States); Li, M. [Headway, 678 Hillview Dr., Milpitas, CA 95035 (United States); Wang, P. [Headway, 678 Hillview Dr., Milpitas, CA 95035 (United States); Dieny, B. [SPINTEC, URA CEA/CNRS, CEA Grenoble/DRFMC, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Devolder, T. [Institut d' Electronique Fondamentale, CNRS UMR 8622, Bat 220, Universite Paris-Sud, Centre d' Orsay, F91405 Orsay Cedex (France)

    2006-01-25

    We study the magnetization dynamics induced at low field by spin-transfer in a pillar-shaped spin valve. The spin valve is a square of 150 nmx 150 nm patterned from a film of IrMn 7 nm/CoFe, 2.4 nm/Ru, 0.8 nm/CoFe, 4.4 nm/Cu, 2.6 nm/CoFe, and 3.6 nm. The spin valve is studied in its anti-parallel state at 50 K. The high frequency voltage noise generated by the DC current flowing through the magneto-resistive device is used to identify the excitations induced by spin-transfer. Between an instability current of 1.72 mA and the switching current of 1.89 mA, we demonstrate the existence of pre-switch steady-state excitations, i.e. low amplitude precession. We study the frequency (10 GHz, red shift -1.46 GHz/mA) of this excitation, its line width (78-246 MHz), the power it carries (113 nW), and the current dependance thereof. We discuss those experimental findings using the formalism of Sun et al. and Valet et al., and show that the experimental behavior can be described by a macrospin approximation only at the very onset of the pre-switch excitations. The early saturation of the excitation power and the non-monotonic switching probability with the current are experimental indications that the pre-switch excitations are strongly non-uniform when approaching the switching current.

  16. Equation-of-motion coupled cluster method for high spin double electron attachment calculations

    Energy Technology Data Exchange (ETDEWEB)

    Musiał, Monika, E-mail: musial@ich.us.edu.pl; Lupa, Łukasz; Kucharski, Stanisław A. [Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice (Poland)

    2014-03-21

    The new formulation of the equation-of-motion (EOM) coupled cluster (CC) approach applicable to the calculations of the double electron attachment (DEA) states for the high spin components is proposed. The new EOM equations are derived for the high spin triplet and quintet states. In both cases the new equations are easier to solve but the substantial simplification is observed in the case of quintets. Out of 21 diagrammatic terms contributing to the standard DEA-EOM-CCSDT equations for the R{sub 2} and R{sub 3} amplitudes only four terms survive contributing to the R{sub 3} part. The implemented method has been applied to the calculations of the excited states (singlets, triplets, and quintets) energies of the carbon and silicon atoms and potential energy curves for selected states of the Na{sub 2} (triplets) and B{sub 2} (quintets) molecules.

  17. Spin-orbital nature of the high-field magnetic state in the Sr4Ru3O10

    Science.gov (United States)

    Granata, Veronica; Capogna, Lucia; Forte, Filomena; Lepetit, Marie-Bernadette; Fittipaldi, Rosalba; Stunault, Anne; Cuoco, Mario; Vecchione, Antonio

    2016-03-01

    We perform a spin-polarized neutron-diffraction study to investigate the nature of the high-field magnetic state of the trilayered Sr4Ru3O10 . The analysis indicates that a high field applied within the a b plane leads to an unbalance of the spin and orbital moments with a spatial profile that is strongly tied to the layers where the electrons are located in the unit cell. We provide evidence of a layer dependent magnetic anisotropy with the inner layers having larger spin and orbital magnetic moments than the outer ones and show that such behavior is robust to temperature variation being persistent above the Curie temperature. By means of an effective model that includes the coupling between the spin-orbital degrees of freedom at inequivalent Ru sites we ascribe the origin of the layer anisotropy to the cooperative effects between octahedral distortions, spin orbit, and Coulomb interactions.

  18. Spin-Circuit Representation of Spin Pumping

    Science.gov (United States)

    Roy, Kuntal

    2017-07-01

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

  19. Rhenium-phthalocyanine molecular nanojunction with high magnetic anisotropy and high spin filtering efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Li, J. [State Key Laboratory of Surface Physics, Key Laboratory of Computational Physical Sciences, and Department of Physics, Fudan University, Shanghai 200433 (China); Institute of Nanomaterial and Nanostructure, Changsha University of Science and Technology, Changsha 410114 (China); Hu, J. [School of Physical Science and Technology, Soochow University, Suzhou, Jiangsu 215006 (China); Wang, H. [State Key Laboratory of Surface Physics, Key Laboratory of Computational Physical Sciences, and Department of Physics, Fudan University, Shanghai 200433 (China); Wu, R. Q., E-mail: wur@uci.edu [State Key Laboratory of Surface Physics, Key Laboratory of Computational Physical Sciences, and Department of Physics, Fudan University, Shanghai 200433 (China); Department of Physics and Astronomy, University of California, Irvine, California 92697-4575 (United States)

    2015-07-20

    Using the density functional and non-equilibrium Green's function approaches, we studied the magnetic anisotropy and spin-filtering properties of various transition metal-Phthalocyanine molecular junctions across two Au electrodes. Our important finding is that the Au-RePc-Au junction has both large spin filtering efficiency (>80%) and large magnetic anisotropy energy, which makes it suitable for device applications. To provide insights for the further experimental work, we discussed the correlation between the transport property, magnetic anisotropy, and wave function features of the RePc molecule, and we also illustrated the possibility of controlling its magnetic state.

  20. Study of superdeformation at zero spin with Skyrme-Hartree-Fock method

    Energy Technology Data Exchange (ETDEWEB)

    Takahara, S.; Tajima, N.; Onishi, N. [Tokyo Univ. (Japan)

    1998-03-01

    Superdeformed (SD) bands have been studied extensively both experimentally and theoretically in the last decade. Since the first observation in {sup 152}Dy in 1986, SD bands have been found in four mass regions, i.e., A {approx} 80, 130, 150 and 190. While these SD bands have been observed only at high spins so far, they may also be present at zero spin like fission isomers in actinide nuclei: The familiar generic argument on the strong shell effect at axis ratio 2:1 does not assume rotations. If non-fissile SD isomers exist at zero spin, they may be utilized to develop new experimental methods to study exotic states, in a similar manner as short-lived high-spin isomers are planned to be utilized as projectiles of fusion reactions in order to populate very high-spin near-yrast states. They will also be useful to test theoretical models whether the models can describe correctly the large deformations of rare-earth nuclei without further complications due to rotations. In this report, we employ the Skyrme-Hartree-Fock method to study the SD states at zero spin. First, we compare various Skyrme force parameter sets to test whether they can reproduce the extrapolated excitation energy of the SD band head of {sup 194}Hg. Second, we systematically search large-deformation solutions with the SkM{sup *} force. The feature of our calculations is that the single-particle wavefunctions are expressed in a three-dimensional-Cartesian-mesh representation. This representation enables one to obtain solutions of various shapes (including SD) without preparing a basis specific to each shape. Solving the mean-field equations in this representation requires, however, a large amount of computation which can be accomplished only with present supercomputers. (author)

  1. High-spin chloro mononuclear MnIII complexes: a multifrequency high-field EPR study.

    Science.gov (United States)

    Mantel, Claire; Chen, Hongyu; Crabtree, Robert H; Brudvig, Gary W; Pécaut, Jacques; Collomb, Marie-Noëlle; Duboc, Carole

    2005-03-01

    The isolation, structural characterization, and electronic properties of two six-coordinated chloromanganese (III) complexes, [Mn(terpy)(Cl)3] (1) and [Mn(Phterpy)(Cl)3] (2), are reported (terpy = 2,2':6'2"-terpyridine, Phterpy = 4'-phenyl-2,2':6',2"-terpyridine). These complexes complement a series of mononuclear azide and fluoride Mn(lll) complexes synthesized with neutral N-tridentate ligands, [Mn(L)(X)3] (X = F- or N3 and L = terpy or bpea [N,N-bis(2-pyridylmethyl)-ethylamine)], previously described. Similar to these previous complexes, 1 and 2 exhibit a Jahn-Teller distortion of the octahedron, characteristic of a high-spin Mn(III) complex (S = 2). The analysis of the crystallographic data shows that, in both cases, the manganese ion lies in the center of a distorted octahedron characterized by an elongation along the tetragonal axis. Their electronic properties were investigated by multifrequency EPR (190-475 GHz) performed in the solid state at different temperatures (5-15 K). This study confirms our previous results and further shows that: i) the sign of D is correlated with the nature of the tetragonal distortion; ii) the magnitude of D is not sensitive to the nature of the anions in our series of rhombic complexes, contrary to the porphyrinic systems; iii) the [E/D] values (0.124 for 1 and 0.085 for 2) are smaller compared to those found for the [Mn(L)(X)3] complexes (in the range of 0.146 to 0.234); and iv) the E term increases when the ligand-field strength of the equatorial ligands decreases.

  2. High-efficiency resonant rf spin rotator with broad phase space acceptance for pulsed polarized cold neutron beams

    Directory of Open Access Journals (Sweden)

    P.-N. Seo

    2008-08-01

    Full Text Available High precision fundamental neutron physics experiments have been proposed for the intense pulsed spallation neutron beams at JSNS, LANSCE, and SNS to test the standard model and search for new physics. Certain systematic effects in some of these experiments have to be controlled at the few ppb level. The NPDGamma experiment, a search for the small parity-violating γ-ray asymmetry A_{γ} in polarized cold neutron capture on parahydrogen, is one example. For the NPDGamma experiment we developed a radio-frequency resonant spin rotator to reverse the neutron polarization in a 9.5  cm×9.5  cm pulsed cold neutron beam with high efficiency over a broad cold neutron energy range. The effect of the spin reversal by the rotator on the neutron beam phase space is compared qualitatively to rf neutron spin flippers based on adiabatic fast passage. We discuss the design of the spin rotator and describe two types of transmission-based neutron spin-flip efficiency measurements where the neutron beam was both polarized and analyzed by optically polarized ^{3}He neutron spin filters. The efficiency of the spin rotator was measured at LANSCE to be 98.8±0.5% for neutron energies from 3 to 20 meV over the full phase space of the beam. Systematic effects that the rf spin rotator introduces to the NPDGamma experiment are considered.

  3. High-efficiency Resonant rf Spin Rotator with Broad Phase Space Acceptance for Pulsed Polarized Cold Neutron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Seo, P. -N. [Los Alamos National Laboratory (LANL); Barron-Palos, L. [Arizona State University; Bowman, J. D. [Los Alamos National Laboratory (LANL); Chupp, T. E. [University of Michigan; Crawford, C. [University of Tennessee, Knoxville (UTK); Dabaghyan, M. [University of New Hampshire; Dawkins, M. [Indiana University; Freedman, S. J. [University of California; Gentile, T. R. [National Institute of Standards and Technology (NIST); Gericke, M. T. [University of Manitoba, Canada; Gillis, R. C. [University of Manitoba, Canada; Greene, G. L. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Hersman, F. W. [University of New Hampshire; Jones, G. L. [Hamilton College, New York; Kandes, M. [University of Michigan; Lamoreaux, S. [Los Alamos National Laboratory (LANL); Lauss, B. [University of California, Berkeley; Leuschner, M. B. [Indiana University; Mahurin, R. [University of Tennessee, Knoxville (UTK); Mason, M. [University of New Hampshire; Mei, J. [Indiana University; Mitchell, G. S. [Los Alamos National Laboratory (LANL); Nann, H. [Indiana University; Page, S. A. [University of Manitoba, Canada; Penttila, S. I. [Los Alamos National Laboratory (LANL); Ramsay, W. D. [University of Manitoba & TRIUMF, Canada; Salas Bacci, A. [Los Alamos National Laboratory (LANL); Santra, S. [Indiana University; Sharma, M. [University of Michigan; Smith, T. B. [University of Dayton, Ohio; Snow, W. [Indiana University; Wilburn, W. S. [Los Alamos National Laboratory (LANL); Zhu, H. [University of New Hampshire

    2008-01-01

    High precision fundamental neutron physics experiments have been proposed for the intense pulsed spallation neutron beams at JSNS, LANSCE, and SNS to test the standard model and search for new physics. Certain systematic effects in some of these experiments have to be controlled at the few ppb level. The NPD Gamma experiment, a search for the small parity-violating {gamma}-ray asymmetry A{sub Y} in polarized cold neutron capture on parahydrogen, is one example. For the NPD Gamma experiment we developed a radio-frequency resonant spin rotator to reverse the neutron polarization in a 9.5 cm x 9.5 cm pulsed cold neutron beam with high efficiency over a broad cold neutron energy range. The effect of the spin reversal by the rotator on the neutron beam phase space is compared qualitatively to rf neutron spin flippers based on adiabatic fast passage. We discuss the design of the spin rotator and describe two types of transmission-based neutron spin-flip efficiency measurements where the neutron beam was both polarized and analyzed by optically polarized {sup 3}He neutron spin filters. The efficiency of the spin rotator was measured at LANSCE to be 98.8 {+-} 0.5% for neutron energies from 3 to 20 meV over the full phase space of the beam. Systematic effects that the rf spin rotator introduces to the NPD Gamma experiment are considered.

  4. Spin dephasing and photoinduced spin diffusion in a high-mobility two-dimensional electron system embedded in a GaAs-(Al,Ga)As quantum well grown in the [110] direction

    Science.gov (United States)

    Völkl, R.; Griesbeck, M.; Tarasenko, S. A.; Schuh, D.; Wegscheider, W.; Schüller, C.; Korn, T.

    2011-06-01

    We have studied spin dephasing and spin diffusion in a high-mobility two-dimensional electron system, embedded in a GaAs/AlGaAs quantum well grown in the [110] direction, by a two-beam Hanle experiment. For very low excitation density, we observe spin lifetimes of more than 16 ns, which rapidly decrease as the pump intensity is increased. Two mechanisms contribute to this decrease: The optical excitation produces holes, which lead to a decay of electron spin via the Bir-Aronov-Pikus mechanism and recombination with spin-polarized electrons. By scanning the distance between the pump and probe beams, we observe the diffusion of spin-polarized electrons over more than 20 μm. For high pump intensity, the spin polarization in a distance of several micrometers from the pump beam is larger than at the pump spot, due to the reduced influence of photogenerated holes.

  5. High-pressure, high-temperature magic angle spinning nuclear magnetic resonance devices and processes for making and using same

    Science.gov (United States)

    Hu, Jian Zhi; Hu, Mary Y.; Townsend, Mark R.; Lercher, Johannes A.; Peden, Charles H. F.

    2015-10-06

    Re-usable ceramic magic angle spinning (MAS) NMR rotors constructed of high-mechanic strength ceramics are detailed that include a sample compartment that maintains high pressures up to at least about 200 atmospheres (atm) and high temperatures up to about least about 300.degree. C. during operation. The rotor designs minimize pressure losses stemming from penetration over an extended period of time. The present invention makes possible a variety of in-situ high pressure, high temperature MAS NMR experiments not previously achieved in the prior art.

  6. PELDOR and RIDME Measurements on a High-Spin Manganese(II) Bisnitroxide Model Complex.

    Science.gov (United States)

    Meyer, Andreas; Schiemann, Olav

    2016-05-26

    A homoleptic bisnitroxide complex of manganese(II) was synthesized as a model system for EPR spectroscopic distance determinations involving high-spin metal ions and more than one distance. The performance of the RIDME experiment is compared with that of the more frequently used PELDOR experiment. It is shown that the PELDOR experiment yields both distances, Mn(II)-nitroxide and nitroxide-nitroxide, and that they can be separated to a certain extent, whereas the RIDME experiment yields only the Mn(II)-nitroxide distance. Both pulse sequences yield artifacts, either due to multispin effects or higher electron-spin transitions. Orientation selection is mostly introduced by the nitroxide signal and can be averaged out by variation of the observer field in the RIDME experiment. Thus, both methods might be used complementarily to obtain a reliable picture of an unknown system.

  7. High spin-polarization in ultrathin Co{sub 2}MnSi/CoPd multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Galanakis, I., E-mail: galanakis@upatras.gr

    2015-03-01

    Half-metallic Co{sub 2}MnSi finds a broad spectrum of applications in spintronic devices either in the form of thin films or as spacer in multilayers. Using state-of-the-art ab-initio electronic structure calculations we exploit the electronic and magnetic properties of ultrathin Co{sub 2}MnSi/CoPd multilayers. We show that these heterostructures combine high values of spin-polarization at the Co{sub 2}MnSi spacer with the perpendicular magnetic anisotropy of binary compounds such as CoPd. Thus they could find application in spintronic/magnetoelectronic devices. - Highlights: • Ab-initio study of ultrathin Co{sub 2}MnSi/CoPd multilayers. • Large values of spin-polarization at the Fermi are retained. • Route for novel spintronic/magnetoelectronic devices.

  8. Spin polarization in high density quark matter under a strong external magnetic field

    DEFF Research Database (Denmark)

    Tsue, Yasuhiko; Da Providência, João; Providência, Constança

    2016-01-01

    In high density quark matter under a strong external magnetic field, possible phases are investigated by using the two-flavor Nambu-Jona-Lasinio (NJL) model with tensor-type four-point interaction between quarks, as well as the axial-vector-type four-point interaction. In the tensor......-type interaction under the strong external magnetic field, it is shown that a quark spin polarized phase is realized in all regions of the quark chemical potential under consideration within the lowest Landau level approximation. In the axial-vector-type interaction, it is also shown that the quark spin polarized...... phase appears in the wide range of the quark chemical potential. In both the interactions, the quark mass in zero and small chemical potential regions increases which indicates that the chiral symmetry breaking is enhanced, namely the magnetic catalysis occurs....

  9. Strongly Deformed Nuclear Shapes at Ultra-High Spin and Shape Coexistence in Nsim 90 Nuclei

    Science.gov (United States)

    Riley, M. A.; Aguilar, A.; Evans, A. O.; Hartley, D. J.; Lagergren, K.; Ollier, J.; Paul, E. S.; Pipidis, A.; Simpson, J.; Teal, C.; Twin, P. J.; Wang, X.; Appelbe, D. E.; Campbell, D. B.; Carpenter, M. P.; Clark, R. M.; Cromaz, M.; Darby, I. G.; Fallon, P.; Garg, U.; Janssens, R. V. F.; Joss, D. T.; Kondev, F. G.; Lauritsen, T.; Lee, I. Y.; Lister, C. J.; Macchiavelli, A. O.; Nolan, P. J.; Petri, M.; Rigby, S. V.; Thompson, J.; Unsworth, C.; Ward, D.; Zhu, S.; Ragnarsson, I.

    2009-03-01

    The N sim 90 region of the nuclear chart has featured prominently as the spectroscopy of nuclei at extreme spin has progressed. This talk will present recent discoveries from investigations of high spin behavior in the N sim 90 Er, Tm and Yb nuclei utilizing the Gammasphere gamma-ray spectrometer. In particular it will include discussion of the beautiful shape evolution and coexistence observed in these nuclei along with the identification of a remarkable new family of band structures. The latter are very weakly populated rotational sequences with high moment of inertia that bypass the classic terminating configurations near spin 40-50 hbar, marking a return to collectivity that extends discrete gamma -ray spectroscopy to well over 60 hbar. Establishing the nature of the yrast states in these nuclei beyond the oblate band-termination states has been a major goal for the past two decades. Cranking calculations suggest that these new structures most likely represent stable triaxial strongly deformed bands that lie in a valley of favored shell energy in deformation and particle-number space.

  10. Metal-biradical chains from a high-spin ligand and bis(hexafluoroacetylacetonato)copper(II).

    Science.gov (United States)

    Rajadurai, Chandrasekar; Enkelmann, Volker; Ikorskii, Vladimir; Ovcharenko, Victor I; Baumgarten, Martin

    2006-11-27

    The synthesis, X-ray crystal structure, and magnetic studies of a rare example of organic/inorganic spin hybrid clusters extended in infinite ladder-type chain [Cu(C5F6HO2)2]7(C35H35N5O4)2 ([Cu(hfac)2]7(pyacbisNN)2, 2) formed by the reaction of a high spin nitronylnitroxide biradical C35H35N5O4 (pyacbisNN, 1) and bis(hexafluroacetylacetonate)copper(II) = Cu(hfac)2 are described. Single-crystal X-ray structure analysis revealed the triclinic P1 space group of 2 with the following parameters: a = 10.6191(4) A, b = 19.6384(7) A, c = 21.941(9) A, alpha = 107.111(7) degrees, beta = 95.107(8) degrees, gamma = 94.208(0) degrees , Z = 2. Each repeating unit in 2 carries a centrosymmetric cyclic six spin and a linear five spin cluster with four different copper coordination environments having octahedral and square planar geometries. These clusters are interconnected to form infinite chains which are running along the crystallographic b axis. The magnetic measurements show nearly paramagnetic behavior with very small variations over a large temperature range. The magnetic properties are thus result of complex competitions of many weak ferro- and antiferromagnetic interactions, which appear as small deviations from quite linear mu(eff) vs T dependence at low temperature. At high temperature (300-14 K), antiferromagnetic behavior dominates a little, while at very low temperature (14-2 K), a small increase of mu(eff) was observed. The magnetic susceptibility data are described by the Curie-Weiss law [chi = C/(T - theta)] with the optimal parameters C = 4.32 +/- 0.01 emuK/mol and theta = - 0.6 +/- 0.3 K, where C is the Curie constant and theta is the Weiss temperature.

  11. Ultrathin Epitaxial Ferromagneticγ-Fe2O3Layer as High Efficiency Spin Filtering Materials for Spintronics Device Based on Semiconductors

    KAUST Repository

    Li, Peng

    2016-06-01

    In spintronics, identifying an effective technique for generating spin-polarized current has fundamental importance. The spin-filtering effect across a ferromagnetic insulating layer originates from unequal tunneling barrier heights for spin-up and spin-down electrons, which has shown great promise for use in different ferromagnetic materials. However, the low spin-filtering efficiency in some materials can be ascribed partially to the difficulty in fabricating high-quality thin film with high Curie temperature and/or partially to the improper model used to extract the spin-filtering efficiency. In this work, a new technique is successfully developed to fabricate high quality, ferrimagnetic insulating γ-Fe2O3 films as spin filter. To extract the spin-filtering effect of γ-Fe2O3 films more accurately, a new model is proposed based on Fowler–Nordheim tunneling and Zeeman effect to obtain the spin polarization of the tunneling currents. Spin polarization of the tunneled current can be as high as −94.3% at 2 K in γ-Fe2O3 layer with 6.5 nm thick, and the spin polarization decays monotonically with temperature. Although the spin-filter effect is not very high at room temperature, this work demonstrates that spinel ferrites are very promising materials for spin injection into semiconductors at low temperature, which is important for development of novel spintronics devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  12. Highly efficient polymer solar cells with printed photoactive layer: rational process transfer from spin-coating

    KAUST Repository

    Zhao, Kui

    2016-09-05

    Scalable and continuous roll-to-roll manufacturing is at the heart of the promise of low-cost and high throughput manufacturing of solution-processed photovoltaics. Yet, to date the vast majority of champion organic solar cells reported in the literature rely on spin-coating of the photoactive bulk heterojunction (BHJ) layer, with the performance of printed solar cells lagging behind in most instances. Here, we investigate the performance gap between polymer solar cells prepared by spin-coating and blade-coating the BHJ layer for the important class of modern polymers exhibiting no long range crystalline order. We find that thickness parity does not always yield performance parity even when using identical formulations. Significant differences in the drying kinetics between the processes are found to be responsible for BHJ nanomorphology differences. We propose an approach which benchmarks the film drying kinetics and associated BHJ nanomorphology development against those of the champion laboratory devices prepared by spin-coating the BHJ layer by adjusting the process temperature. If the optimization requires the solution concentration to be changed, then it is crucial to maintain the additive-to-solute volume ratio. Emulating the drying kinetics of spin-coating is also shown to help achieve morphological and performance parities. We put this approach to the test and demonstrate printed PTB7:PC71BM polymer solar cells with efficiency of 9% and 6.5% PCEs on glass and flexible PET substrates, respectively. We further demonstrate performance parity for two other popular donor polymer systems exhibiting rigid backbones and absence of a long range crystalline order, achieving a PCE of 9.7%, the highest efficiency reported to date for a blade coated organic solar cell. The rational process transfer illustrated in this study should help the broader and successful adoption of scalable printing methods for these material systems.

  13. TOPICAL REVIEW: Highly spin-polarized materials and devices for spintronics

    Directory of Open Access Journals (Sweden)

    Koichiro Inomata et al.

    2008-01-01

    Full Text Available The performance of spintronics depends on the spin polarization of the current. In this study half-metallic Co-based full-Heusler alloys and a spin filtering device (SFD using a ferromagnetic barrier have been investigated as highly spin-polarized current sources. The multilayers were prepared by magnetron sputtering in an ultrahigh vacuum and microfabricated using photolithography and Ar ion etching. We investigated two systems of Co-based full-Heusler alloys, Co2Cr1 ? xFexAl (CCFA(x and Co2FeSi1 ? xAlx (CFSA(x and revealed the structure and magnetic and transport properties. We demonstrated giant tunnel magnetoresistance (TMR of up to 220% at room temperature and 390% at 5 K for the magnetic tunnel junctions (MTJs using Co2FeSi0.5Al0.5 (CFSA(0.5 Heusler alloy electrodes. The 390% TMR corresponds to 0.81 spin polarization for CFSA(0.5 at 5 K. We also investigated the crystalline structure and local structure around Co atoms by x-ray diffraction (XRD and nuclear magnetic resonance (NMR analyses, respectively, for CFSA films sputtered on a Cr-buffered MgO (001 substrate followed by post-annealing at various temperatures in an ultrahigh vacuum. The disordered structures in CFSA films were clarified by NMR measurements and the relationship between TMR and the disordered structure was discussed. We clarified that the TMR of the MTJs with CFSA(0.5 electrodes depends on the structure, and is significantly higher for L21 than B2 in the crystalline structure. The second part of this paper is devoted to a SFD using a ferromagnetic barrier. The Co ferrite is investigated as a ferromagnetic barrier because of its high Curie temperature and high resistivity. We demonstrate the strong spin filtering effect through an ultrathin insulating ferrimagnetic Co-ferrite barrier at a low temperature. The barrier was prepared by the surface plasma oxidization of a CoFe2 film deposited on a MgO (001 single crystal substrate, wherein the spinel structure of CoFe2O4 (CFO

  14. Monitoring and data acquisition of the high speed hydrogen pellet in SPINS

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Samiran Shanti, E-mail: samiran@ipr.res.in; Mishra, Jyotishankar; Gangradey, Ranjana; Dutta, Pramit; Rastogi, Naveen; Panchal, Paresh; Nayak, Pratik; Agarwal, Jyoti; Bairagi, Pawan; Patel, Haresh; Sharma, Hardik

    2016-11-15

    Highlights: • Pellet INjector System with monitoring and data acquisition is described. • A high speed camera was used to view pellet size, and its flight trajectory. • PXI based high speed control system is used data acquisition. • Pellets of length 2–4.8 mm and speed 250–750 m/s were obtained. - Abstract: Injection of solid hydrogen pellets is an efficient way of replenishing the spent fuel in high temperature plasmas. Aiming that, a Single Pellet INjector System (SPINS) is developed at Institute for Plasma Research (IPR), India, to initiate pellet injection related research in SST-1. The pellet injector is controlled by a PXI system based data acquisition and control (DAC) system for pellet formation, precise firing control, data collection and diagnostics. The velocity of high speed moving pellets is estimated by using two sets of light gate diagnostic. Apart from light gate, a fast framing camera is used to measure the pellet size and its speed. The pellet images are captured at a frame rate of ∼200,000 frames per second at (128 × 64) pixel resolution with an exposure time of 1 μs. Using these diagnostic, various cylindrical pellets of length ranging from 2 to 4.8 mm and speed 250–750 m/s were successfully obtained. This paper describes the control and data acquisition system of SPINS, the techniques for measurement of pellet velocity and capturing images of high speed moving pellet.

  15. Octupole shapes and shape changes at high spins in the Z approx 58, N approx 88 nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Nazarewicz, W. (Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States) Joint Institute for Heavy Ion Research, Holifield Heavy Ion Research Facility, P.O. Box 2008, Oak Ridge, Tennessee 37831 (United States)); Tabor, S.L. (Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States))

    1992-05-01

    The shapes of rotating Xe, Ba, Ce, Nd, and Sm nuclei (84{le}{ital N}{le}94) are calculated using the cranking model with the Woods-Saxon average potential and pairing. The lightest isotopes of Xe and Ba have nearly spherical ground states, but develop octupole and quadrupole deformations under rotation which remain up to very high spins. The ground states of the heavier isotopes have octupole and quadrupole deformations which persist up to medium spins ({ital I}{approx}12{h bar}). At higher spins, a shape transition is predicted to reflection-symmetric aligned many-quasiparticle configurations.

  16. Solution spinning of high-? oxide superconductors: part VII. The effect of polyvinyl alcohol spinning medium on the sintering of ? superconducting filaments

    Science.gov (United States)

    Tomita, Hisayo; Goto, Tomoko; Takahashi, Kiyohisa

    1996-05-01

    As basic research for the solution spinning of high-0953-2048/9/5/005/img8 oxide superconductor, the effect of poly(vinyl alcohol) (PVA) spinning medium on the sintering of 0953-2048/9/5/005/img9 filament was examined. A precursor filament was produced by dry-spinning starting from a homogeneous aqueous PVA solution of Y, Ba and Cu acetates. The as-drawn filament was pyrolysed to remove volatile components and sintered to generate a superconducting phase. The degree of polymerization (DP) of PVA and the content of acetates in the precursor filament affected the 0953-2048/9/5/005/img10 of the sintered filament. Although most filaments exhibited high 0953-2048/9/5/005/img10 greater than 0953-2048/9/5/005/img12 at 77 K and 0 T, superconductivity above 77 K was not observed for the filament spun from PVA solution of DP=2450 with [acetates]/[PVA]=2 and sintered at 900 and 0953-2048/9/5/005/img13C for 15 min. The filament had a dense structure due to liquid phase sintering. The filament with high 0953-2048/9/5/005/img10 had a skin - core structure, and the highest 0953-2048/9/5/005/img10 of 0953-2048/9/5/005/img16 at 77 K and 0 T was attained for the filament from DP=3500 with [acetates]/[PVA]=4.

  17. Resonance Raman frequencies and core size for low- and high-spin nickel porphyrins

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D.; Su, Y.O.; Spiro, T.G.

    1986-10-22

    Resonance Raman (RR) spectra are reported with B- and Q-band excitation for nickel(II) complexes of octaethylporphyrin (OEP), protoporphyrin IX dimethyl ester (PP), and meso-tetraphenylporphine (TPP) in methylene chloride (4-coordinate, low spin) and piperidine (pip) (6-coordinate, high spin). The large core size expansion accompanying the formation of the 6-coordinate species (1.96-2.04 A) is reflected in large decreases, up to 40 cm/sup -1/ in the positions of high-frequency porphyrin skeletal modes. For NiOEP and NiPP, these are in near-quantitative accord with the core size correlations obtained previously for iron porphyrin complexes, although certain deviations due to differential coupling with the vinyl modes of protoporphyrin are noted. Contributions of a minority 5-coordinate complex to the RR spectrum of NiTPP in piperidine, previously noted on the basis of photolysis effects, are evaluated quantitatively from titration data. Formation of a monopiperidine adduct, detected previously via a RR study of NiTPP(pip)/sub 2/ photolysis, is examined for nickel meso-tetrakis(p-cyanophenyl)porphine. Equilibrium constants for successive addition of piperidine ligands, K/sub 1/ = 0.4 and K/sub 2/ = 2.5 M/sup -1/, are evaluated from optical titration data, and the absorptivities of the 5- and 6-coordinate species are found to be nearly the same, consistent with both having a high-spin configuration. The frequency of the 5-coordinate nu/sub 4/ RR band is likewise found to be much closer to the 6-coordinate than to the 4-coordinate frequency.

  18. Spin-on metal oxide materials with high etch selectivity and wet strippability

    Science.gov (United States)

    Yao, Huirong; Mullen, Salem; Wolfer, Elizabeth; McKenzie, Douglas; Rahman, Dalil; Cho, JoonYeon; Padmanaban, Munirathna; Petermann, Claire; Hong, SungEun; Her, YoungJun

    2016-03-01

    Metal oxide or metal nitride films are used as hard mask materials in semiconductor industry for patterning purposes due to their excellent etch resistances against the plasma etches. Chemical vapor deposition (CVD) or atomic layer deposition (ALD) techniques are usually used to deposit the metal containing materials on substrates or underlying films, which uses specialized equipment and can lead to high cost-of-ownership and low throughput. We have reported novel spin-on coatings that provide simple and cost effective method to generate metal oxide films possessing good etch selectivity and can be removed by chemical agents. In this paper, new spin-on Al oxide and Zr oxide hard mask formulations are reported. The new metal oxide formulations provide higher metal content compared to previously reported material of specific metal oxides under similar processing conditions. These metal oxide films demonstrate ultra-high etch selectivity and good pattern transfer capability. The cured films can be removed by various chemical agents such as developer, solvents or wet etchants/strippers commonly used in the fab environment. With high metal MHM material as an underlayer, the pattern transfer process is simplified by reducing the number of layers in the stack and the size of the nano structure is minimized by replacement of a thicker film ACL. Therefore, these novel AZ® spinon metal oxide hard mask materials can potentially be used to replace any CVD or ALD metal, metal oxide, metal nitride or spin-on silicon-containing hard mask films in 193 nm or EUV process.

  19. Spin-symmetry conversion and internal rotation in high J molecular systems

    Science.gov (United States)

    Mitchell, Justin; Harter, William

    2006-05-01

    Dynamics and spectra of molecules with internal rotation or rovibrational coupling is approximately modeled by rigid or semi-rigid rotors with attached gyroscopes. Using Rotational Energy (RE)^1 surfaces, high resolution molecular spectra for high angular momentum show two distinct but related phenomena; spin-symmetry conversion and internal rotation. For both cases the high total angular momentum allows for transitions that would otherwise be forbidden. Molecular body-frame J-localization effects associated with tight energy level-clusters dominate the rovibronic spectra of high symmetry molecules, particularly spherical tops at J>10. ^2 The effects include large and widespread spin-symmetry mixing contrary to conventional wisdom^3 about weak nuclear moments. Such effects are discussed showing how RE surface plots may predict them even at low J. Classical dynamics of axially constrained rotors are approximated by intersecting rotational-energy-surfaces (RES) that have (J-S).B.(J-S) forms in the limit of constraints that do no work. Semi-classical eigensolutions are compared to those found by direct diagonalization. ^1 W.G Hater, in Handbook of Atomic, Molecular and Optical Physics, edited by G.W.F Drake (Springer, Germany 2006) ^2 W. G. Harter, Phys. Rev. A24,192-262(1981). ^3 G. Herzberg, Infrared and Raman Spectra (VanNostrand 1945) pp. 458,463.

  20. RHIC SPIN FLIPPER

    Energy Technology Data Exchange (ETDEWEB)

    BAI,M.; ROSER, T.

    2007-06-25

    This paper proposes a new design of spin flipper for RHIC to obtain full spin flip with the spin tune staying at half integer. The traditional technique of using an rf dipole or solenoid as spin flipper to achieve full spin flip in the presence of full Siberian snake requires one to change the snake configuration to move the spin tune away from half integer. This is not practical for an operational high energy polarized proton collider like RHIC where beam lifetime is sensitive to small betatron tune change. The design of the new spin flipper as well as numerical simulations are presented.

  1. High precision measurements of the neutron spin structure in Hall A at Jlab

    Energy Technology Data Exchange (ETDEWEB)

    Annand, R M; Cates, G; Cisbani, E; Franklin, G B; Liyanage, N; Puckett, A; Rosner, G; Wojtsekhowski, B

    2012-04-01

    Conclusions of this presentation are: (1) JLab energy upgrade will offer new exciting opportunities to study the nucleon (spin) structure such as high precision, unexplored phase space, flavor decomposition; (2) Large technological efforts is in progress to optimally exploit these opportunities; (3) HallA will be the first hall to get the new beam, first experiment expected to run in 2014; (4) A1n likely one of the first experiments to take data in the new 12 GeV era; and (5) SIDIS exp. will follow in couple of years.

  2. Configuration assignments of yrare high-spin structures in sup 1 sup 2 sup 6 Cs

    CERN Document Server

    Li, X F; Lu, J B; Zhao, G Y; Yin, L C; Meng, R; Zhang, Z L; Wen, L J; Liu, Y Z; Zhou, X H; Guo, Y X; Lei, X G; Liu, Z; Zheng, Y; He, J J

    2003-01-01

    High-spin states in sup 1 sup 2 sup 6 Cs were populated in the reaction sup 1 sup 1 sup 6 Cd( sup 1 sup 4 N,4n) at a beam energy of 65 MeV. About 50 new transitions were placed in a level scheme that consists of six rotational structures, three of which have been observed for the first time. The newly observed bands and a previously reported but uninterpreted band were assigned configurations based on their population, aligned angular momentum, energy signature splitting and B(M1)/B(E2) ratios (for the strongly coupled bands). (orig.)

  3. Atomic masses above /sup 146/Gd derived from a shell model analysis of high spin states

    CERN Document Server

    Blomqvist, J; Daly, P J; Kleinheinz, P

    1981-01-01

    Using extensive spectroscopic data on high spin states involving aligned valence nucleons in very neutron deficient nuclei above /sup 146/Gd the authors have derived the ground state masses of /sup 146 /Gd, /sup 147,148/Tb, /sup 148,149,150/Dy, /sup 149,150,151/Ho, and /sup 150,151,152/Er from a shell model analysis. The mass values show a pronounced irregularity in the two-proton separation energies at /sup 146/Gd. The results also link nine alpha -decay chains to the known masses. (0 refs).

  4. E/Z Isomers and Isomerization

    Science.gov (United States)

    Liaaen-Jensen, Synnøve; Lutnœes, Bjart Frode

    The natural occurrence of several carotenoid cis isomers and their biological significance were not anticipated in 1962, when the classical monograph on cis-trans isomeric carotenoids [1] was published. More recent research has demonstrated that various cis isomers occur naturally in bacteria plants, algae and invertebrate animals, and are present in human blood and tissues. The participation of cis isomers in the biosynthethic route to coloured carotenoids is well established (Volume 3, Chapter 2). Important biological functions of (15Z)-carotenoids in photosynthesis have been revealed [2]. In relation to health aspects of carotenoids, the bioavailability of cis isomers may be higher than that of the all-trans isomer [3], and accumulated evidence suggests that cis/trans isomerization may occur in biological tissues, particularly of lycopene (31) in human serum [4] (Volume 5, Chapter 7).

  5. Optical absorption spectra of Ag-11 isomers

    DEFF Research Database (Denmark)

    Martinez, Jose Ignacio; Fernandez, E. M.

    2009-01-01

    The optical absorption spectra of the three most; stable structural isomers of the Ag-11 cluster were calculated using the time-dependent, density functional theory within the Casida formalism. The slightly different, spectra, of the isomers may permit the identification of the ground-stale confi......The optical absorption spectra of the three most; stable structural isomers of the Ag-11 cluster were calculated using the time-dependent, density functional theory within the Casida formalism. The slightly different, spectra, of the isomers may permit the identification of the ground......-stale configuration predominantly present in the laboratory beams based on a direct comparison between the calculated photoabsorptiou response for the Ag-11 isomers and the measured spectra of medium-size silver clusters trapped in noble gas Ar and Ne matrices at different, temperatures. This assignment is confirmed...

  6. Spin crossover and Mott—Hubbard transition under high pressure and high temperature in the low mantle of the Earth

    Science.gov (United States)

    Ovchinnikov, S. G.; Ovchinnikova, T. M.; Plotkin, V. V.; Dyad'kov, P. G.

    2015-11-01

    Effect of high pressure induced spin crossover on the magnetic, electronic and structural properties of the minerals forming the Earth's low mantle is discussed. The low temperature P, T phase diagram of ferropericlase has the quantum phase transition point Pc = 56 GPa at T = 0 confirmed recently by the synchrotron Mössbauer spectroscopy. The LDA+GTB calculated phase diagram describes the experimental data. Its extension to the high temperature resulted earlier in prediction of the metallic properties of the Earth's mantle at the depth 1400 km insulator transition and compare them with the experimental seismic and geomagnetic field data.

  7. "Star" morphologies of charged nanodrops comprised of conformational isomers.

    Science.gov (United States)

    In Oh, Myong; Paliy, Maxim; Consta, Styliani

    2018-01-14

    We study the spatial distribution of conformational isomers surrounding a central macroion in a charged droplet with linear dimensions in the nanometer range. Dimethyl carbonate and formic acid are selected as typical solvents that undergo isomerization and a charged buckyball (C60) is selected as a representative example of a macroion. The study is performed by atomistic molecular dynamics simulations. We find that when the charge of the buckyball is above a threshold value, it induces the formation of concentric shells of different conformational isomers surrounding the macroion. The presence of layers with different dielectric properties necessitates the use of different state equations for the solvent polarization in each layer. We find that at a high charge state of the buckyball, the nearest layer to the macroion comprises the conformers with the highest dipole moment. The interface of the outer layers of conformers is characterized by "ray"-forming structures of the higher dielectric constant isomers penetrating into the layer of the lowest dielectric constant isomers. For high values of the solvent dielectric constant, the charged droplet acquires a "star"-like global shape. We demonstrate that these distinct droplet structures are a manifestation of charge-induced instability. We describe this simulation-based phenomenology by an analytical theory that supports this conclusion. The findings suggest new experimental research venues that may explore the reactivity and assembly of molecules within regions of different dielectric properties in droplets.

  8. New μs isomers in the neutron-rich 210Hg nucleus

    Science.gov (United States)

    Gottardo, A.; Valiente-Dobón, J. J.; Benzoni, G.; Gadea, A.; Lunardi, S.; Boutachkov, P.; Bruce, A. M.; Górska, M.; Grebosz, J.; Pietri, S.; Podolyák, Zs.; Pfützner, M.; Regan, P. H.; Weick, H.; Alcántara Núñez, J.; Algora, A.; Al-Dahan, N.; de Angelis, G.; Ayyad, Y.; Alkhomashi, N.; Allegro, P. R. P.; Bazzacco, D.; Benlliure, J.; Bowry, M.; Bracco, A.; Bunce, M.; Camera, F.; Casarejos, E.; Cortes, M. L.; Crespi, F. C. L.; Corsi, A.; Denis Bacelar, A. M.; Deo, A. Y.; Domingo-Pardo, C.; Doncel, M.; Dombradi, Zs.; Engert, T.; Eppinger, K.; Farrelly, G. F.; Farinon, F.; Farnea, E.; Geissel, H.; Gerl, J.; Goel, N.; Gregor, E.; Habermann, T.; Hoischen, R.; Janik, R.; John, P. R.; Klupp, S.; Kojouharov, I.; Kurz, N.; Lenzi, S. M.; Leoni, S.; Mandal, S.; Menegazzo, R.; Mengoni, D.; Million, B.; Modamio, V.; Morales, A. I.; Napoli, D. R.; Naqvi, F.; Nicolini, R.; Nociforo, C.; Prochazka, A.; Prokopowicz, W.; Recchia, F.; Ribas, R. V.; Reed, M. W.; Rudolph, D.; Sahin, E.; Schaffner, H.; Sharma, A.; Sitar, B.; Siwal, D.; Steiger, K.; Strmen, P.; Swan, T. P. D.; Szarka, I.; Ur, C. A.; Walker, P. M.; Wieland, O.; Wollersheim, H.-J.

    2013-10-01

    Neutron-rich nuclei in the lead region, beyond N = 126, have been studied at the FRS-RISING setup at GSI, exploiting the fragmentation of a primary uranium beam. Two isomeric states have been identified in 210Hg: the 8+ isomer expected from the seniority scheme in the νg9/2 shell and a second one at low spin and low excitation energy. The decay strength of the 8+ isomer confirms the need of effective three-body forces in the case of neutron-rich lead isotopes. The other unexpected low-lying isomer has been tentatively assigned as a 3- state, although this is in contrast with theoretical expectations.

  9. New μs isomers in the neutron-rich {sup 210}Hg nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Gottardo, A., E-mail: andrea.gottardo@lnl.infn.it [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro, 35020 (Italy); Dipartimento di Fisica dell' Università degli Studi di Padova, Padova, 35131 (Italy); Valiente-Dobón, J.J. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro, 35020 (Italy); Benzoni, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano, 20133 (Italy); Gadea, A. [Instituto de Física Corpuscular, CSIC-Universitat de València, València, E-46980 (Spain); Lunardi, S. [Dipartimento di Fisica dell' Università degli Studi di Padova, Padova, 35131 (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Padova, 35131 (Italy); Boutachkov, P. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, D-64291 (Germany); Bruce, A.M. [School of Computing, Engineering and Mathematics, University of Brighton, Brighton, BN2 4GJ (United Kingdom); Górska, M. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, D-64291 (Germany); Grebosz, J. [Niewodniczanski Institute of Nuclear Physics, Polish Academy of Science, Krakow, PL-31-342 (Poland); Pietri, S. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, D-64291 (Germany); Podolyák, Zs. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Pfützner, M. [Faculty of Physics, University of Warsaw, Warsaw, PL-00681 (Poland); Regan, P.H. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Weick, H. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, D-64291 (Germany); Alcántara Núñez, J. [Universidade de Santiago de Compostela, Santiago de Compostela, E-175706 (Spain); and others

    2013-10-01

    Neutron-rich nuclei in the lead region, beyond N=126, have been studied at the FRS-RISING setup at GSI, exploiting the fragmentation of a primary uranium beam. Two isomeric states have been identified in {sup 210}Hg: the 8{sup +} isomer expected from the seniority scheme in the νg{sub 9/2} shell and a second one at low spin and low excitation energy. The decay strength of the 8{sup +} isomer confirms the need of effective three-body forces in the case of neutron-rich lead isotopes. The other unexpected low-lying isomer has been tentatively assigned as a 3{sup −} state, although this is in contrast with theoretical expectations.

  10. Optimal control of fast and high-fidelity quantum state transfer in spin-1/2 chains

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiong-Peng [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Shao, Bin, E-mail: sbin610@bit.edu.cn [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Hu, Shuai; Zou, Jian [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Wu, Lian-Ao [Department of Theoretical Physics and History of Science, The Basque Country University (EHU/UPV), PO Box 644, 48080 Bilbao (Spain); Ikerbasque, Basque Foundation for Science, 48011 Bilbao (Spain)

    2016-12-15

    Spin chains are promising candidates for quantum communication and computation. Using quantum optimal control (OC) theory based on the Krotov method, we present a protocol to perform quantum state transfer with fast and high fidelity by only manipulating the boundary spins in a quantum spin-1/2 chain. The achieved speed is about one order of magnitude faster than that is possible in the Lyapunov control case for comparable fidelities. Additionally, it has a fundamental limit for OC beyond which optimization is not possible. The controls are exerted only on the couplings between the boundary spins and their neighbors, so that the scheme has good scalability. We also demonstrate that the resulting OC scheme is robust against disorder in the chain.

  11. High spin levels populated in multinucleon-transfer reactions with 480 MeV /sup 12/C

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, L.; Boucenna, A.; Linck, I.; Lott, B.; Rebmeister, R.; Schulz, N.; Sens, J.C.; Mermaz, M.C.; Berthier, B.; Lucas, R.; and others

    1988-06-01

    Two- and three-nucleon stripping reactions induced by 480 MeV /sup 12/C have been studied on /sup 12/C, /sup 16/O, /sup 28/Si, /sup 40/Ca, and /sup 54/Fe target nuclei. Discrete levels are fed with cross sections up to 1 mbsr for d-transfer reactions and 1 order and 2 orders of magnitude less for 2p- and /sup 3/He-transfer reactions, respectively. These reactions preferentially populate high spin states with stretched configurations. Several spin assignments were known from transfer reactions induced by lighter projectiles at incident energies well above the Coulomb barrier. In the case of two-nucleon transfer reactions, the energy of these states is well reproduced by crude shell model calculations. Such estimates are of use in proposing spins of newly observed states especially as the shapes of the measured angular distributions are independent of the final spin of the residual nucleus.

  12. High-spin states and lifetime measurements in sup 1 sup 7 sup 1 Hf

    CERN Document Server

    Cullen, D M; Appelbe, D E; Wilson, A N; Paul, E S; Bergström, M H; Sharpey-Schafer, J F; Baktash, C; Frosch, I; Lee, I Y; Macchiavelli, A O; MacLeod, R W; Prevost, D; Theisen, C; Curien, D

    2000-01-01

    This paper describes the results of two complementary experiments which studied the properties of the well-deformed nucleus sup 1 sup 7 sup 1 Hf. The first experiment, with a thin self-supporting target, extended the rotational bands built upon the [633]7/2, [512]5/2 and [521]1/2 configurations up to spins of 73/2-85/2 Planck constant. The configurations of these bands and observed band crossings are discussed within the framework of the cranked-shell model. The second experiment employed a backed target in order to measure the lifetimes, by the Doppler Shift Attenuation method, and thereby establish deformations for some of the states in the collective rotational bands. The extracted deformations are found to be consistent with those predicted from theoretical Total Routhian Surface calculations. These deformations provide strong evidence that the high-spin states in sup 1 sup 7 sup 1 Hf, and perhaps more importantly, in the region where the high-K (K suppi=19/2 sup + and K suppi=23/2 sup -) isomeric states ...

  13. Study of spin-exchange optically pumped 3He cells with high polarisation and long lifetimes

    Science.gov (United States)

    Parnell, S. R.; Babcock, E.; Nünighoff, K.; Skoda, M. W. A.; Boag, S.; Masalovich, S.; Chen, W. C.; Georgii, R.; Wild, J. M.; Frost, C. D.

    2009-01-01

    We present a detailed investigation into 3He neutron spin filter cells polarised by spin exchange optical pumping (SEOP). We include measurements of the absolute 3He polarisation using neutron transmission and characterisation of both the X-factor and 3He relaxation times ( T1) for a number of cells. For one cell we calculated a maximum 3He polarisation of 79% with a T1 of 633 h. The measured X-factor of this cell, X=0.17±0.01, is low. For all cells polarisations of >71% are observed. In addition we present 3He relaxation data for a new design of magneto-static cavity with a field of high homogeneity ΔB/B0≈3.5×10-4 cm-1. This compact device provides a magnetic field in an orientation suitable for in situ optical pumping that minimises the field inhomogeneity contribution to the T1 to 930 h in a 1 bar cell, the longest reported on beam thus far. The results suggest that high 3He polarisation with long relaxation times can now be routinely obtained with SEOP, enabling time independent incident beam polarisation to be easily implemented across many different neutron scattering instruments.

  14. High-spin states and lifetime measurements in {sup 171}Hf

    Energy Technology Data Exchange (ETDEWEB)

    Cullen, D.M.; Reed, A.T.; Appelbe, D.E.; Wilson, A.N.; Paul, E.S.; Bergstroem, M.H.; Sharpey-Schafer, J.F.; Baktash, C.; Frosch, I.; Lee, I.Y.; Macchiavelli, A.O.; MacLeod, R.W.; Prevost, D.; Theisen, Ch.; Curien, D

    2000-06-19

    This paper describes the results of two complementary experiments which studied the properties of the well-deformed nucleus {sup 171}Hf. The first experiment, with a thin self-supporting target, extended the rotational bands built upon the [633]7/2, [512]5/2 and [521]1/2 configurations up to spins of 73/2-85/2{Dirac_h}. The configurations of these bands and observed band crossings are discussed within the framework of the cranked-shell model. The second experiment employed a backed target in order to measure the lifetimes, by the Doppler Shift Attenuation method, and thereby establish deformations for some of the states in the collective rotational bands. The extracted deformations are found to be consistent with those predicted from theoretical Total Routhian Surface calculations. These deformations provide strong evidence that the high-spin states in {sup 171}Hf, and perhaps more importantly, in the region where the high-K (K{sup {pi}}=19/2{sup +} and K{sup {pi}}=23/2{sup -}) isomeric states decay, retain their well-deformed axial symmetry.

  15. Preparation of CNTs rope by electrostatic and airflow field carding with high speed rotor spinning

    Science.gov (United States)

    Dai, J. F.; Liu, J. F.; Zou, J. T.; Dai, Y. L.

    2015-12-01

    The large-scale preparation of disorderly CNTs with a length larger than 3 mm using CVD method were aligned in polymer monomer airflow fields in a quartz tube with an internal diameter of 200 μm and a length of 1.5 m. The airflow aligned CNTs at the output end of the pipe connects to a copper nozzle with an electrostatic field of applied voltage 5x105 V/m and space length of 0.03 m, which were further realigned using via electrostatic spinning. End to end spray into the high speed rotor twisted single-stranded carbon nanotubes threads via rotor spinning technology. The essential component of this technique was the use of carbon nanotubes at a high rotory speed (200000 r/min) combined with the double twisting of filaments that were twisted together to increase the radial friction of the entire section. SEM micrography showed that carbon nanotube thread has a uniform diameter of approximately 200 μm. Its tensile strength was tested up to 2.7 Gpa, with a length of several meters.

  16. Fabrication of highly oriented nanoporous fibers via airflow bubble-spinning

    Science.gov (United States)

    Liu, Fujuan; Li, Shaokai; Fang, Yue; Zheng, Fangfang; Li, Junhua; He, Jihuan

    2017-11-01

    Highly oriented Poly(lactic acid) (PLA) nanofibers with nanoporous structures has been successfully fabricated via airflow bubble-spinning without electrostatic hazard. In this work, the volatile solvent was necessary for preparing the nanoporous fiber, which was attributed to the competition between phase separation and solvent evaporation. The interconnected porous structures were affected by the processing variables of solution concentration, airflow temperature, collecting distance and relative humidity (RH). Besides, the rheological properties of solutions were studied and the highly oriented PLA nanofibers with nanoporous structure were also completely characterized using scanning electron microscope (SEM). This study provided a novel technique that successfully gets rid of the potential safety hazards caused by unexpected static to prepare highly oriented nanoporous fibers, which would demonstrate an impressive prospect for the fields of adsorption and filtration.

  17. Return of K selection at high spin: Decay of bandheads in {sup 178}W

    Energy Technology Data Exchange (ETDEWEB)

    Walker, P.M.; Purry, C.S.; Gelletly, W. [Univ. of Surrey, Guildford (United Kingdom)] [and others

    1996-12-31

    In contrast to the de-excitation of the low-seniority states in {sup 178}W, the decay of the K{sup {pi}} = 25{sup +}, 8-quasiparticle isomer is strongly hindered. This is seen to be related to its yrast status.

  18. Identification of isomers of organometallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Mbue, Sona Peter; Cho, Kwang Hwi [Dept. of Bioinformatics and Life Science, School of Systems Biomedical Science, Soongsil University,Seoul (Korea, Republic of)

    2015-06-15

    The yaChI is a newly suggested chemical naming system. However, yaChI is a derivative of the IUPAC InChI with a modified algorithm that includes additional layers of chemical structure information. Consequently, yaChI string contains more structure details while preserving the original structure file information and can distinctively identify very closely related compounds reducing the chances of ambiguity in chemical compound databases as opposed to the general SMILES, InChI, and InChIKey. This study examines the relative performances of yaChI, SMILES, InChI, and InChIKey in duplication check for isomers. For simplicity, a small data set of 28 organometallic compounds (structural isomers of Rh-containing compounds) subdivided into three major groups (A, B, and C) based on the number and the type of ligands attached to the center atom was used to study the performances of each encoding scheme in describing chemical structures. SMILES, InChI, and InChIKey were generated using Openbabel and RDkit, whereas yaChI strings were generated with in-house program. Strings generated from SMILES, InChI, and InChIKey though different, resulted to only three unique chemical identifiers, with each belonging to one group indicating the presence of only three unique compounds in the study data. However, yaChI results depicted that all structures in each group are indeed unique and differ among themselves as well as those from other groups, mapping each structure with a unique identifier given a total number of 28 unique structures in the study data. This high perception of yaChI probe justifies its accuracy and reliability in duplication check among closely related compounds especially structures exhibiting stereo properties.

  19. High Resolution Magic Angle Spinning 1H-NMR Metabolic Profiling of Nanoliter Biological Tissues at High Magnetic Field

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Ju; Hu, Jian Z.; Burton, Sarah D.; Hoyt, David W.

    2013-03-05

    It is demonstrated that a high resolution magic angle spinning 1H-NMR spectrum of biological tissue samples with volumes as small as 150 nanoliters, or 0.15 mg in weight, can be acquired in a few minutes at 21.1 T magnetic field using a commercial 1.6 mm fast-MAS probe with minor modification of the MAS rotor. The strategies of sealing the samples inside the MAS rotor to avoid fluid leakage as well as the ways of optimizing the signal to noise are discussed.

  20. Structure of high-spin states in sup 1 sup 0 sup 0 Pd

    CERN Document Server

    Pérez, G E; Algora, A; Dombrádi, Z; Nyakó, B M; Timar, J; Zolnai, L; Wyss, R; Cederkäll, J; Johnson, A; Kérek, A; Klamra, W; Norlin, L O; Lipoglavsek, M; Fahlander, C; Likar, A; Palacz, M; Atac, A; Nyberg, J; Persson, J; Gizon, A; Gizon, J; Boston, A J; Paul, E S; Grawe, H; Schubart, R; Joss, D T; Juutinen, S; Maekelae, E; Kownacki, J P; De Poli, M; Bednarczyk, P; De Angelis, G; Seweryniak, D; Foltescu, D; Roth, H A; Skeppstedt, Ö; Jerrestam, D; Shizuma, T; Sletten, G; Toermaenen, S

    2001-01-01

    High-spin states of the neutron deficient sup 1 sup 0 sup 0 Pd nucleus have been investigated via the sup 5 sup 0 Cr( sup 5 sup 8 Ni, 4p alpha) and sup 7 sup 0 Zn( sup 3 sup 6 S,6n) heavy-ion induced reactions. For the detection of evaporated particles and gamma rays the NORDBALL array equipped with ancillary detectors and the EUROGAM II detector system were utilized. By the use of in-beam spectroscopic methods 89 transitions belonging to sup 1 sup 0 sup 0 Pd have been observed, 49 of which were identified for the first time. The level scheme has been extended up to E sub x approx 16 MeV excitation energy and I approx 25 Planck constant. The experimental results were compared with the predictions of cranked shell model calculations. Maximal spin alignments were found in the (pi g sub 9 sub / sub 2) sup - sup 4 sub 1 sub 2 sub sup + (nu d sub 5 sub / sub 2 ,g sub 7 sub / sub 2 sup 3 h sub 1 sub 1 sub / sub 2) sub 1 sub 3 sub sup - and (pi g sub 9 sub / sub 2 sup - sup 3 p sub 1 sub / sub 2) sub 1 sub 1 sub sup...

  1. Enhanced Central System of the Traversing Rod for High-Performance Rotor Spinning Machines

    Directory of Open Access Journals (Sweden)

    Valtera Jan

    2017-03-01

    Full Text Available The paper deals with the improvement of central traversing system on rotor spinning machines, where rectilinear motion with variable stroke is used. A new system of traversing rod with implemented set of magnetic-mechanical energy accumulators is described. Mathematical model of this system is analysed in the MSC. Software Adams/View and verified by an experimental measurement on a real-length testing rig. Analysis results prove the enhancement of devised traversing system, where the overall dynamic force is reduced considerably. At the same time, the precision of the traversing movement over the machine length is increased. This enables to increase machine operating speed while satisfying both the maximal tensile strength of the traversing rod and also output bobbin size standards. The usage of the developed mathematical model for determination of the optimal number and distribution of accumulators over the traversing rod of optional parameters is proved. The potential of the devised system for high-performance rotor spinning machines with longer traversing rod is also discussed.

  2. Equation-of-motion coupled cluster method for the description of the high spin excited states

    Energy Technology Data Exchange (ETDEWEB)

    Musiał, Monika, E-mail: musial@ich.us.edu.pl; Lupa, Łukasz; Kucharski, Stanisław A. [Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice (Poland)

    2016-04-21

    The equation-of-motion (EOM) coupled cluster (CC) approach in the version applicable for the excitation energy (EE) calculations has been formulated for high spin components. The EE-EOM-CC scheme based on the restricted Hartree-Fock reference and standard amplitude equations as used in the Davidson diagonalization procedure yields the singlet states. The triplet and higher spin components require separate amplitude equations. In the case of quintets, the relevant equations are much simpler and easier to solve. Out of 26 diagrammatic terms contributing to the R{sub 1} and R{sub 2} singlet equations in the case of quintets, only R{sub 2} operator survives with 5 diagrammatic terms present. In addition all terms engaging three body elements of the similarity transformed Hamiltonian disappear. This indicates a substantial simplification of the theory. The implemented method has been applied to the pilot study of the excited states of the C{sub 2} molecule and quintet states of C and Si atoms.

  3. Evolution of spin excitations in a gapped antiferromagnet from the quantum to the high-temperature limit

    DEFF Research Database (Denmark)

    Kenzelmann, M.; Cowley, R.A.; Buyers, W.J.L.

    2002-01-01

    We have mapped from the quantum to the classical limit the spin excitation spectrum of the antiferromagnetic spin-1 Heisenberg chain system CsNiCl3 in its paramagnetic phase from T=5 to 200 K. Neutron scattering shows that the excitations are resonant and dispersive up to at least T=70 Ksimilar o...... and the experiment is not consistent with the random phase approximation for coupled quantum chains. At T=200 K, the structure factor and second energy moment of the excitation spectrum are in excellent agreement with the high-temperature series expansion.......We have mapped from the quantum to the classical limit the spin excitation spectrum of the antiferromagnetic spin-1 Heisenberg chain system CsNiCl3 in its paramagnetic phase from T=5 to 200 K. Neutron scattering shows that the excitations are resonant and dispersive up to at least T=70 Ksimilar...... is in agreement with quantum Monte Carlo calculations for the spin-1 chain. xi is also consistent with the single mode approximation, suggesting that the excitations are short-lived single particle excitations. Below T=12 K where three-dimensional spin correlations are important, xi is shorter than predicted...

  4. Observation of isomeric decays and the high spin states in doubly-odd 208Fr

    CERN Document Server

    Kanjilal, D; Goswami, A; Kshetri, R; Raut, R; Saha, S; Bhowmik, R K; Gehlot, J; Muralithar, S; Singh, R P; Jnaneswari, G; Mukherjee, G; Mukherjee, B

    2009-01-01

    Neutron deficient isotopes of Francium (Z=87, N=121-123) as excited nuclei were produced in the fusion-evaporation reaction: 197Au(16O,xn)[213-x]Fr at 100 MeV. The gamma-rays from the residues were observed through the high sensitivity Germanium Clover detector array INGA. The decay of the high spin states and the isomeric states of the doubly-odd 208Fr nuclei, identified from the known sequence of ground state transitions, were observed. The half lives of the 194(2) keV isomeric transition, known from earlier observations, was measured to be 233(18) ns. A second isomeric transition at 383(2) keV and half life of 33(7) ns was also found. The measured half lives were compared with the corresponding single particle estimates, based on a the level scheme obtained from the experiment.

  5. High spin states and isomeric decays in doubly-odd 208Fr

    Science.gov (United States)

    Kanjilal, D.; Bhattacharya, S.; Goswami, A.; Kshetri, R.; Raut, R.; Saha, S.; Bhowmik, R. K.; Gehlot, J.; Muralithar, S.; Singh, R. P.; Jnaneswari, G.; Mukherjee, G.; Mukherjee, B.

    2010-10-01

    Neutron deficient isotopes of francium ( Z=87, N˜121-123) as excited nuclei were produced in the fusion-evaporation reaction: 197Au( 16O, xn) 213 - xFr at 100 MeV. The γ rays from the residues were observed through the high sensitivity Germanium Clover detector array INGA. The decay of the high spin states and the isomeric states of the doubly-odd 208Fr nuclei, identified from the known sequence of ground state transitions, were observed. The half-lives of the E=194(2) keV isomeric transition, known from earlier observations, was measured to be T=233(18) ns. A second isomeric transition at E=383(2) keV and T=33(7) ns was also found. The measured half-lives were compared with the corresponding single particle estimates, based on the level scheme obtained from the experiment.

  6. A Study of Particle Beam Spin Dynamics for High Precision Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Fiedler, Andrew J. [Northern Illinois Univ., DeKalb, IL (United States)

    2017-05-01

    In the search for physics beyond the Standard Model, high precision experiments to measure fundamental properties of particles are an important frontier. One group of such measurements involves magnetic dipole moment (MDM) values as well as searching for an electric dipole moment (EDM), both of which could provide insights about how particles interact with their environment at the quantum level and if there are undiscovered new particles. For these types of high precision experiments, minimizing statistical uncertainties in the measurements plays a critical role. \\\\ \\indent This work leverages computer simulations to quantify the effects of statistical uncertainty for experiments investigating spin dynamics. In it, analysis of beam properties and lattice design effects on the polarization of the beam is performed. As a case study, the beam lines that will provide polarized muon beams to the Fermilab Muon \\emph{g}-2 experiment are analyzed to determine the effects of correlations between the phase space variables and the overall polarization of the muon beam.

  7. Highly Nuclear-Spin-Polarized Deuterium Atoms from the UV Photodissociation of Deuterium Iodide

    Science.gov (United States)

    Sofikitis, Dimitris; Glodic, Pavle; Koumarianou, Greta; Jiang, Hongyan; Bougas, Lykourgos; Samartzis, Peter C.; Andreev, Alexander; Rakitzis, T. Peter

    2017-06-01

    We report a novel highly spin-polarized deuterium (SPD) source, via the photodissociation of deuterium iodide at 270 nm. I (P2 3 /2) photofragments are ionized with m -state selectivity, and their velocity distribution measured via velocity-map slice imaging, from which the D polarization is determined. The process produces ˜100 % electronically polarized D at the time of dissociation, which is then converted to ˜60 % nuclear D polarization after ˜1.6 ns . These production times for SPD allow collision-limited densities of ˜1 018 cm-3 and at production rates of ˜1 021 s-1 which are 1 06 and 1 04 times higher than conventional (Stern-Gerlach separation) methods, respectively. We discuss the production of SPD beams, and combining high-density SPD with laser fusion, to investigate polarized D-T, D -He 3 , and D-D fusion.

  8. Summary: symmetries and spin

    Energy Technology Data Exchange (ETDEWEB)

    Haxton, W.C. (Institute for Nuclear Theory, Department of Physcis, FM-15, University of Washington, Seattle, Washington 98195 (US))

    1989-05-01

    I discuss a number of the themes of the Symmetries and Spin session of the 8th International Symposium on High Energy Spin Physics: parity non-conservation, CP/T nonconservation, and tests of charge symmetry and charge independence.

  9. Sensitive determination of nitrophenol isomers by reverse-phase high-performance liquid chromatography in conjunction with liquid-liquid extraction

    Science.gov (United States)

    A method for the highly sensitive determination of 2-, 3- and 4- nitrophenols was developed using reverse-phase high-performance liquid chromatography (RP-HPLC) with a UV photodiode array detector. Using a reverse-phase column and 40% aqueous acetonitrile as an eluent (i.e. isocratic elution), the i...

  10. Determination and separation of bisphenol A, phthalate metabolites and structural isomers of parabens in human urine with conventional high-pressure liquid chromatography combined with electrospray ionisation tandem mass spectrometry.

    Science.gov (United States)

    Myridakis, Antonis; Balaska, Eirini; Gkaitatzi, Christina; Kouvarakis, Antonis; Stephanou, Euripides G

    2015-03-01

    Phthalates, bisphenol A (BPA) and parabens (PBs), organic chemicals widely used in everyday products, are considered to be endocrine disruptors. We propose a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of seven phthalate metabolites, six PBs and BPA in human urine. All three categories of the above endocrine disruptors were simultaneously extracted from 1 mL of human urine using solid phase extraction. In addition, with a conventional reversed phase LC column, we achieved for the first time the separation of three pairs of structural isomers, namely iso-/n-butyl paraben, propyl paraben and monobutyl phthalate. LC-MS/MS was operated and tested in both electrospray ionisation (ESI) and atmospheric pressure chemical ionisation (APCI). ESI was selected for the analysis due to its superior stability and repeatability. The method limit of detection (mLOD), achieved for a single set of high-performance LC conditions, ranged from 0.01 to 0.84 ng/mL for phthalate metabolites, from 0.06 to 0.24 ng/mL for PBs and was 2.01 ng/mL for BPA. Derivatisation of BPA with dansyl chloride lowered its mLOD to 0.007 ng/mL. Blank contamination was non-detectable. The present method was successfully applied for the analysis of the above-mentioned compounds in 80 male human urine samples.

  11. Spin dynamics in high-T{sub C} superconducting cuprates; Dynamique de spins dans les oxydes de cuivre supraconducteurs a haute temperature critique

    Energy Technology Data Exchange (ETDEWEB)

    Bourges, Ph

    2003-07-01

    This work is dedicated to the detailed investigations of the magnetic resonance peak in the superconducting state of cuprates. The existence of such a peak could be the signature of a mechanism linked to magnetism that could explain high critical temperature superconductivity. Inelastic neutron scattering is an adequate tool for the understanding of cuprate properties because it reveals magnetic fluctuations whose behaviour and variety depend strongly on temperature and on the level of doping. The last part of this work is dedicated to the study of spin dynamics in YBa{sub 2}Cu{sub 3}O{sub 6+x} system.

  12. An auto-balancer device for high spin-drying frequencies (LoWash Project

    Directory of Open Access Journals (Sweden)

    Clerc Christian

    2015-01-01

    Full Text Available Auto-balancing or active control balancing can be efficient solutions for high speed rotors with changing out-of-balance loads like washing machines in spin-drying mode. In the LoWash EU project, Vibratec is in charge to design, to build and to validate a balancing system for reducing the vibrations at high spin-drying speeds. The system is based on two trolleys rolling in a ring linked to the drum. The trolley shape allows a ring cross section optimization and they are equipped with a mechanism for escaping the disadvantage encountered at low speeds by similar devices. Analytical and multi-body models are first made for understanding the mechanisms, highlighting the driving parameters and drawing the final design of a first prototype which is inserted in a washing machine drum. Different tests are carried out for different initial unbalances and different rotation speeds: the residual unbalance is measured by means of a set of accelerometers mounted on the tub, while the mobile masses behaviour is observed by means of a large aperture swift camera. The test results highlight the auto-balancer high efficiency but also the sensitivity to geometrical defects which should be corrected in the next systems. According the theory, the balancing is efficient when the rotation frequency is significantly greater than the hanging frequencies. The multi-body model relevance is also demonstrated. A washer-dryer prototype including an auto-balancer second prototype and two other innovations, regarding thermal exchange efficiency and drum insulation, will be tested in operating conditions.

  13. New Isomers in the Neutron-Rich Region Beyond 208Pb

    Science.gov (United States)

    Gottardo, A.; Valiente-Dobón, J. J.; Benzoni, G.; Gadea, A.; Lunardi, S.; Boutachkov, P.; Bruce, A. M.; Górska, M.; Grebosz, J.; Pietri, S.; Podolyák, Zs.; Pfützner, M.; Regan, P. H.; Weick, H.; Alcántara Núñez, J.; Algora, A.; Al-Dahan, N.; de Angelis, G.; Ayyad, Y.; Alkhomashi, N.; Allegro, P. R. P.; Bazzacco, D.; Benlliure, J.; Bowry, M.; Bracco, A.; Bunce, M.; Camera, F.; Casarejos, E.; Cortes, M. L.; Crespi, F. C. L.; Corsi, A.; Bacelar, A. M. Denis; Deo, A. Y.; Domingo-Pardo, C.; Doncel, M.; Dombradi, Zs.; Engert, T.; Eppinger, K.; Farrelly, G. F.; Farinon, F.; Farnea, E.; Geissel, H.; Gerl, J.; Goel, N.; Gregor, E.; Habermann, T.; Hoischen, R.; Janik, R.; John, P. R.; Klupp, S.; Kojouharov, I.; Kurz, N.; Lenzi, S. M.; Leoni, S.; Mandal, S.; Menegazzo, R.; Mengoni, D.; Million, B.; Modamio, V.; Morales, A. I.; Napoli, D. R.; Naqvi, F.; Nicolini, R.; Nociforo, C.; Prochazka, A.; Prokopowicz, W.; Recchia, F.; Ribas, R. V.; Reed, M. W.; Rudolph, D.; Sahin, E.; Schaffner, H.; Sharma, A.; Sitar, B.; Siwal, D.; Steiger, K.; Strmen, P.; Swan, T. P. D.; Szarka, I.; Ur, C. A.; Walker, P. M.; Wieland, O.; Wollersheim, H.-J.

    2014-03-01

    The region of neutron-rich nuclei beyond 208Pb has been very difficult to explore due to its high mass and exoticity. However, recent experimental improvements allowed one to perform a quite extended isomer decay spectroscopy of these nuclei.

  14. Quantum interference distinguishes between constitutional isomers

    OpenAIRE

    Tüxen, Jens; Gerlich, Stefan; Eibenberger, Sandra; Arndt, Markus; Mayor, Marcel

    2014-01-01

    Matter waves, as introduced by de Broglie in 1923, are a fundamental quantum phenomenon, describing the delocalized center of mass motion of massive bodies and we show here their sensitivity to the molecular structure of constitutional isomers.

  15. High-resolution electron microscopy in spin pumping NiFe/Pt interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ley Domínguez, D., E-mail: david.ley@cimav.edu.mx; Sáenz-Hernández, R. J.; Faudoa Arzate, A.; Arteaga Duran, A. I.; Ornelas Gutiérrez, C. E.; Solís Canto, O.; Botello-Zubiate, M. E.; Rivera-Gómez, F. J.; Matutes-Aquino, J. A. [Centro de Investigación en Materiales Avanzados, S.C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua 31109 (Mexico); Azevedo, A.; Silva, G. L. da; Rezende, S. M. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil)

    2015-05-07

    In order to understand the effect of the interface on the spin pumping and magnetic proximity effects, high resolution transmission electron microscopy and ferromagnetic resonance (FMR) were used to analyze Py/Pt bilayer and Pt/Py/Pt trilayer systems. The samples were deposited by dc magnetron sputtering at room temperature on Si (001) substrates. The Py layer thickness was fixed at 12 nm in all the samples and the Pt thickness was varied in a range of 0–23 nm. A diffusion zone of approximately 8 nm was found in the Py/Pt interfaces and confirmed by energy dispersive X-ray microanalysis. The FMR measurements show an increase in the linewidth and a shift in the ferromagnetic resonance field, which reach saturation.

  16. Spin-Orbit Torque from a Magnetic Heterostructure of High-Entropy Alloy

    Science.gov (United States)

    Chen, Tian-Yue; Chuang, Tsao-Chi; Huang, Ssu-Yen; Yen, Hung-Wei; Pai, Chi-Feng

    2017-10-01

    High-entropy alloy (HEA) is a family of metallic materials with nearly equal partitions of five or more metals, which might possess mechanical and transport properties that are different from conventional binary or tertiary alloys. In this work, we demonstrate current-induced spin-orbit torque (SOT) magnetization switching in a Ta-Nb-Hf-Zr-Ti HEA-based magnetic heterostructure with perpendicular magnetic anisotropy. The maximum dampinglike SOT efficiency from this particular HEA-based magnetic heterostructure is further determined to be |ζDLHEA | ≈0.033 by hysteresis-loop-shift measurements, while that for the Ta control sample is |ζDLTa | ≈0.04 . Our results indicate that HEA-based magnetic heterostructures can serve as an alternative group of potential candidates for SOT device applications due to the possibility of tuning buffer-layer properties with more than two constituent elements.

  17. Quantitative Temperature Dependence of Longitudinal Spin Seebeck Effect at High Temperatures

    Directory of Open Access Journals (Sweden)

    Ken-ichi Uchida

    2014-11-01

    Full Text Available We report temperature-dependent measurements of longitudinal spin Seebeck effects (LSSEs in Pt/Y_{3}Fe_{5}O_{12} (YIG/Pt systems in a high temperature range from room temperature to above the Curie temperature of YIG. The experimental results show that the magnitude of the LSSE voltage in the Pt/YIG/Pt systems rapidly decreases with increasing the temperature and disappears above the Curie temperature. The critical exponent of the LSSE voltage in the Pt/YIG/Pt systems at the Curie temperature is estimated to be 3, which is much greater than that for the magnetization curve of YIG. This difference highlights the fact that the mechanism of the LSSE cannot be explained in terms of simple static magnetic properties in YIG.

  18. Nuclear inelastic scattering study of a dinuclear iron(II) complex showing a direct spin transition

    Energy Technology Data Exchange (ETDEWEB)

    Wolny, J. A., E-mail: wolny@physik.uni-kl.de [University of Kaiserslautern, Department of Physics (Germany); Garcia, Y. [Université Catholique de Louvain, Institute of Condensed Matter and Nanosciences, Molecules, Solids and Reactivity (IMCN/MOST) (Belgium); Faus, I.; Rackwitz, S. [University of Kaiserslautern, Department of Physics (Germany); Schlage, K.; Wille, H.-C. [DESY (Germany); Schünemann, V. [University of Kaiserslautern, Department of Physics (Germany)

    2016-12-15

    The results of the nuclear inelastic scattering (NIS)/nuclear resonance vibrational spectroscopy (NRVS) for the powder spectra of dimeric [Fe {sub 2}L{sub 5}(NCS) {sub 4}] (L = N-salicylidene-4-amino-1,2,4-triazole) complex are presented. This system is spin crossover (SCO) material tagged with a fluorophore that can sense or “feel” the SCO signal ripping through the molecular network and thereby providing an opportunity to register the SCO transition. The spectra have been measured for the low-spin and high-spin phases of the complex. The high-spin isomer reveals one broad band above 200 cm {sup −1}, while the low-spin one displays two intense bands in the range from 390 to 430 cm {sup −1}, accompanied by a number of weaker bands below this area and one at ca. 490 cm {sup −1}. A normal coordinate analysis based on density functional calculations yields the assignment of the spin marker bands to particular molecular modes. In addition the vibrational contribution to the spin transition has been estimated.

  19. Interpulse phase corrections for unbalanced pseudo-continuous arterial spin labeling at high magnetic field.

    Science.gov (United States)

    Hirschler, Lydiane; Debacker, Clément S; Voiron, Jérôme; Köhler, Sascha; Warnking, Jan M; Barbier, Emmanuel L

    2017-06-06

    To evaluate a prescan-based radiofrequency phase-correction strategy for unbalanced pseudo-continuous arterial spin labeling (pCASL) at 9.4 T in vivo and to test its robustness toward suboptimal shim conditions. Label and control interpulse phases were optimized separately by means of two prescans in rats. The mean perfusion as well as the interhemispherical symmetry were measured for several phase combinations (optimized versus theoretical phases) to evaluate the correction quality. Interpulse phases were also optimized under degraded shim conditions (i.e., up to four times the study shim values) to test the strategy's robustness. For all tested shim conditions, the full arterial spin labeling (ASL) signal could be restored. Without any correction, the relative ASL signal was 1.4 ± 1.7%. It increased to 3.6 ± 1.4% with an optimized label phase and to 5.3 ± 1.2% with optimized label and control phases. Moreover, asymmetry between brain hemispheres, which could be as high as 100% without phase optimization, was dramatically reduced to 1 ± 3% when applying optimized label and control phases. Pseudo-continuous ASL at high magnetic field is very sensitive to shim conditions. Label and control radiofrequency phase optimization based on prescans robustly maximizes the ASL signal obtained with unbalanced pCASL and minimizes the asymmetry between hemispheres. Magn Reson Med, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  20. A debranching enzyme IsoM of Corallococcus sp. strain EGB with potential in starch processing.

    Science.gov (United States)

    Li, Zhoukun; Ji, Kai; Zhou, Jie; Ye, Xianfeng; Wang, Ting; Luo, Xue; Huang, Yan; Cao, Hui; Cui, Zhongli; Kong, Yi

    2017-12-01

    Interest in use of resistant starch and maltooligosaccharides as functional foods and biopreservatives has grown in recent years. In this research, a novel debranching enzyme IsoM from Corallococcus sp. strain EGB was identified and expressed in P. pastoris GS115. Sequence alignments showed that IsoM was typical isoamylase with the specific activity up to 70,600U/mg, which belongs to glycoside hydrolase family 13 (GH 13). Enzymatic reaction pattern demonstrated that IsoM has high debranching efficiency against α-1,6-glycosidic bond of branched starch, and exhibited no activity towards α-1,4-glycosidic bond. The potential application of IsoM in starch processing was determined. IsoM was a potential candidate for the production of RS (70.9%) from raw starch, which was comparable with the commercial pullulanase (Promozyme(®)D2). IsoM also improved the maltohexaose yield in combination with maltohexaose-producing α-amylase AmyM (KM114206), the maltohexaose yield was improved by 63.3% compared with 21.9% improvement of Promozyme(®)D2. The results of RS production and combination with other amylases suggesting that IsoM is a potential candidate for the efficient conversion of starch. Copyright © 2017. Published by Elsevier B.V.

  1. Tuning the Spin State in LaCoO3 Thin Films for Enhanced High-Temperature Oxygen Electrocatalysis.

    Science.gov (United States)

    Hong, Wesley T; Gadre, Milind; Lee, Yueh-Lin; Biegalski, Michael D; Christen, Hans M; Morgan, Dane; Shao-Horn, Yang

    2013-08-01

    The slow kinetics of oxygen surface exchange hinders the efficiency of high-temperature oxygen electrocatalytic devices such as solid oxide fuel cells and oxygen separation membranes. Systematic investigations of material properties that link to catalytic activity can aid in the rational design of highly active cathode materials. Here, we explore LaCoO3 thin films as a model system for tuning catalytic activity through strain-induced changes in the Co spin state. We demonstrate that Raman spectroscopy can be used to probe the Co-O bond strength at different temperatures to determine the relative spin occupancies of LaCoO3. We find that strain can be used to reduce the spin transition temperature and promote the occupation of higher spin states that weaken the Co-O bond. The decrease in Co-O bond strength and increased spin moment of the thin films result in significant enhancements of the oxygen surface exchange kinetics by up to 2 orders of magnitude.

  2. Advances in large, transportable, highly spin-polarized, solid HD targets operable in the frozen-spin mode in a 1-4K temperature environment

    Science.gov (United States)

    Lewis, Aaron Paul

    The development of large, portable highly spin-polarized solid HD targets has been in progress at Syracuse University for the past 5 years. These targets are scheduled for deployment at Brookhaven National Laboratory, bearing the acronym SPHICE (Spin-Polarized Hydrogen Ice), for studies of the electro-magnetic spin structure of the nucleus via scattering of polarized gammas from the HD polarized protons and deuterons. The target work has just reached the milestone demonstration of the complete system, including polarization of triple targets containing 4 moles of solid HD, aging of these targets so that they retain their polarization for months under storage at a temperature of 1.3K and in an 8 Tesla field, and for at least a week at operational conditions of 1.3K and 0.7 Tesla in an in-beam cryostat. Cold-transfers of the polarized targets to a storage cryostat have been successfully carried out, and the storage cryostat has been trucked from Syracuse to BNL with one polarized target, sufficient to test the in-beam operations there. The complete system is presented here, with emphasis on innovations for engagement and disengagement of multiple targets, a solution to the challenge of attaining sufficiently strong RF fields in the large volume probe coils at acceptable power dissipation in the cables, and the polarization production and monitoring in the highly inhomogeneous magnetic fields owing to the multiple targets and the large dimensions of the targets. In this first multiple target production and extraction-to-storage cycle, air-ice accumulation in the dilution refrigerator due to repetitive use of cold sliding o-ring seals resulted in a rupture of one of the inserted targets, and a consequent partial thermal short from a solid HD ice bridge. The o-ring fault was cured with double evacuatable o-ring seals, and the air-ice was successfully cleaned out. However, the refrigerator operating base temperature was substantially higher than that normally obtained

  3. A high performance ceria based interdiffusion barrier layer prepared by spin-coating

    DEFF Research Database (Denmark)

    Plonczak, Pawel; Joost, Mario; Hjelm, Johan

    2011-01-01

    . The decomposition of the polymer precursor used in the spin-coating process was studied. The depositions were performed on anode supported half cells. By controlling the sintering temperature between each spin-coating process, dense and crack-free CGO films with a thickness of approximately 1 μm were obtained...

  4. Orientation and thickness dependence of magnetization at the interfacesof highly spin-polarized manganite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chopdekar, Rajesh V.; Arenholz, Elke; Suzuki, Y.

    2008-08-18

    We have probed the nature of magnetism at the surface of (001), (110) and (111)-oriented La{sub 0.7}Sr{sub 0.3}MnO{sub 3} thin films. The spin polarization of La{sub 0.7}Sr{sub 0.3}MnO{sub 3} thin films is not intrinsically suppressed at all surfaces and interfaces but is highly sensitive to both the epitaxial strain state as well as the substrate orientation. Through the use of soft x-ray spectroscopy, the magnetic properties of (001), (110) and (111)-oriented La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/SrTiO{sub 3} interfaces have been investigated and compared to bulk magnetometry and resistivity measurements. The magnetization of (110) and (111)-oriented La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/SrTiO{sub 3} interfaces are more bulk-like as a function of thickness whereas the magnetization at the (001)-oriented La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/SrTiO{sub 3} interface is suppressed significantly below a layer thickness of 20 nm. Such findings are correlated with the biaxial strain state of the La{sub 0.7}Sr{sub 0.3}MnO{sub 3} films; for a given film thickness it is the tetragonal distortion of (001) La{sub 0.7}Sr{sub 0.3}MnO{sub 3} that severely impacts the magnetization, whereas the trigonal distortion for (111)-oriented films and monoclinic distortion for (110)-oriented films have less of an impact. These observations provide evidence that surface magnetization and thus spin polarization depends strongly on the crystal surface orientation as well as epitaxial strain.

  5. Highly Stretchable Core-Sheath Fibers via Wet-Spinning for Wearable Strain Sensors.

    Science.gov (United States)

    Tang, Zhenhua; Jia, Shuhai; Wang, Fei; Bian, Changsheng; Chen, Yuyu; Wang, Yonglin; Li, Bo

    2018-02-12

    Lightweight, stretchable, and wearable strain sensors have recently been widely studied for the development of health monitoring systems, human-machine interfaces, and wearable devices. Herein, highly stretchable polymer elastomer-wrapped carbon nanocomposite piezoresistive core-sheath fibers are successfully prepared using a facile and scalable one-step coaxial wet-spinning assembly approach. The carbon nanotube-polymeric composite core of the stretchable fiber is surrounded by an insulating sheath, similar to conventional cables, and shows excellent electrical conductivity with a low percolation threshold (0.74 vol %). The core-sheath elastic fibers are used as wearable strain sensors, exhibiting ultra-high stretchability (above 300%), excellent stability (>10 000 cycles), fast response, low hysteresis, and good washability. Furthermore, the piezoresistive core-sheath fiber possesses bending-insensitiveness and negligible torsion-sensitive properties, and the strain sensing performance of piezoresistive fibers maintains a high degree of stability under harsh conditions. On the basis of this high level of performance, the fiber-shaped strain sensor can accurately detect both subtle and large-scale human movements by embedding it in gloves and garments or by directly attaching it to the skin. The current results indicate that the proposed stretchable strain sensor has many potential applications in health monitoring, human-machine interfaces, soft robotics, and wearable electronics.

  6. Development of neutron resonance spin flipper for high resolution NRSE spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Kitaguchi, Masaaki [Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494 (Japan)]. E-mail: kitaguch@rri.kyoto-u.ac.jp; Hino, Masahiro [Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494 (Japan); Kawabata, Yuji [Research Reactor Institute, Kyoto University, Kumatori, Osaka 590-0494 (Japan); Hayashida, Hirotoshi [Faculty of Engineering, Kyoto University, Kyoto 606-8501 (Japan); Tasaki, Seiji [Faculty of Engineering, Kyoto University, Kyoto 606-8501 (Japan); Maruyama, Ryuji [JAEA, Tokai, Ibaraki 319-1195 (Japan); Yamazaki, Dai [JAEA, Tokai, Ibaraki 319-1195 (Japan); Ebisawa, Toru [JAEA, Tokai, Ibaraki 319-1195 (Japan); Torikai, Naoya [KEK, Tsukuba, Ibaraki 305-0801 (Japan)

    2006-11-15

    Neutron spin echo (NSE) is one of the techniques with the highest energy resolution for measurement of quasi-elastic scattering. In neutron resonance spin echo (NRSE), two separated neutron resonance spin flippers (RSFs) replace a homogeneous static magnetic field for spin precession in a conventional NSE. We have made a new type of RSF with pure aluminum wires in order to reduce the scattering from the surface. Test experiments have been performed at cold neutron beam line MINE1 at JRR-3M reactor in JAERI and the beam line CN3 at KUR The spin-flip probability was higher than 0.95 at a neutron wavelength of 0.81 nm and a RSF frequency of 100 kHz.

  7. High-efficiency control of spin-wave propagation in ultra-thin yttrium iron garnet by the spin-orbit torque

    Energy Technology Data Exchange (ETDEWEB)

    Evelt, M.; Demidov, V. E., E-mail: demidov@uni-muenster.de [Institute for Applied Physics and Center for Nanotechnology, University of Muenster, 48149 Muenster (Germany); Bessonov, V. [M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, Yekaterinburg 620041 (Russian Federation); Demokritov, S. O. [Institute for Applied Physics and Center for Nanotechnology, University of Muenster, 48149 Muenster (Germany); M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, Yekaterinburg 620041 (Russian Federation); Prieto, J. L. [Instituto de Sistemas Optoelectrónicos y Microtecnologa (UPM), Ciudad Universitaria, Madrid 28040 (Spain); Muñoz, M. [IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), PTM, E-28760 Tres Cantos, Madrid (Spain); Ben Youssef, J. [Laboratoire de Magnétisme de Bretagne CNRS, Université de Bretagne Occidentale, 29285 Brest (France); Naletov, V. V. [Service de Physique de l' État Condensé, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette (France); Institute of Physics, Kazan Federal University, Kazan 420008 (Russian Federation); Loubens, G. de [Service de Physique de l' État Condensé, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette (France); Klein, O. [INAC-SPINTEC, CEA/CNRS and Univ. Grenoble Alpes, 38000 Grenoble (France); Collet, M.; Garcia-Hernandez, K.; Bortolotti, P.; Cros, V.; Anane, A. [Unité Mixte de Physique CNRS, Thales, Univ. Paris Sud, Université Paris-Saclay, 91767 Palaiseau (France)

    2016-04-25

    We study experimentally with submicrometer spatial resolution the propagation of spin waves in microscopic waveguides based on the nanometer-thick yttrium iron garnet and Pt layers. We demonstrate that by using the spin-orbit torque, the propagation length of the spin waves in such systems can be increased by nearly a factor of 10, which corresponds to the increase in the spin-wave intensity at the output of a 10 μm long transmission line by three orders of magnitude. We also show that, in the regime, where the magnetic damping is completely compensated by the spin-orbit torque, the spin-wave amplification is suppressed by the nonlinear scattering of the coherent spin waves from current-induced excitations.

  8. Preparation and structural characterization of the Ih and the D5h isomers of the endohedral fullerenes Tm3N@C80: icosahedral C80 cage encapsulation of a trimetallic nitride magnetic cluster with three uncoupled Tm3+ ions.

    Science.gov (United States)

    Zuo, Tianming; Olmstead, Marilyn M; Beavers, Christine M; Balch, Alan L; Wang, Guangbin; Yee, Gordon T; Shu, Chunying; Xu, Liaosa; Elliott, Bevan; Echegoyen, Luis; Duchamp, James C; Dorn, Harry C

    2008-06-16

    We report an efficient method for the preparation and purification of the Ih and the D5h isomers of Tm3N@C80. Following preparation in a Kratschmer-Huffman electric-arc generator, the Tm3N@C80 isomers were obtained by a chemical separation process followed by a one-stage isomer selective chromatographic high-performance liquid chromatography (HPLC) separation (pyrenyl, 5PYE column). The HPLC chromatographic retention behavior on a pentabromobenzyl (5PBB) column suggests a charge transfer of approximately 6 electrons; [M3N] 6+@C80(6-) and the chromatographic retention mechanisms of the Ih and the D5h isomers of Tm3N@C80 on both 5PBB and 5PYE columns are discussed. Single-crystal X-ray diffraction data demonstrate that the Tm3N cluster has a planar structure but represents a tight fit for trapping the Tm3N cluster inside the I h - and the D 5h -C 80 cages. Specifically, the Tm atoms punch out the cage carbon atoms adjacent to them. The "punched out" effect can be demonstrated by cage radii and pyramidal angles at cage carbon atoms near the Tm atoms. The magnetic susceptibility (chiT) for Tm3N@ Ih -C80 was found to exhibit Curie-Weiss behavior with C = 23.4 emu.K/mol, which is consistent with the calculated value for three uncoupled Tm3+ ions by considering the spin and orbital contributions with no quenching of the orbital angular momentum ( L = 5, S = 1, and J = 6; Ccalcd = 23.3 emu.K/mol). The electrochemical measurements demonstrate that both the Ih and the D5h isomers of Tm3N@C80 have a large electrochemical gap.

  9. Quantum Spin Liquids

    OpenAIRE

    Savary, Lucile; Balents, Leon

    2016-01-01

    Quantum spin liquids may be considered "quantum disordered" ground states of spin systems, in which zero point fluctuations are so strong that they prevent conventional magnetic long range order. More interestingly, quantum spin liquids are prototypical examples of ground states with massive many-body entanglement, of a degree sufficient to render these states distinct phases of matter. Their highly entangled nature imbues quantum spin liquids with unique physical aspects, such as non-local e...

  10. High-Frequency and -Field Electron Paramagnetic Resonance of High-Spin Manganese(III) in Porphyrinic Complexes.

    Science.gov (United States)

    Krzystek, J.; Telser, Joshua; Pardi, Luca A.; Goldberg, David P.; Hoffman, Brian M.; Brunel, Louis-Claude

    1999-12-27

    High-field and -frequency electron paramagnetic resonance (HFEPR) spectroscopy has been used to study two complexes of high-spin manganese(III), d(4), S = 2. The complexes studied were (tetraphenylporphyrinato)manganese(III) chloride and (phthalocyanato)manganese(III) chloride. Our previous HFEPR study (Goldberg, D. P.; Telser, J.; Krzystek, J.; Montalban, A. G.; Brunel, L.-C.; Barrett, A. G. M.; Hoffman, B. M. J. Am. Chem. Soc. 1997, 119, 8722-8723) included results on the porphyrin complex; however, we were unable to obtain true powder pattern HFEPR spectra, as the crystallites oriented in the intense external magnetic field. In this work we are now able to immobilize the powder, either in an n-eicosane mull or KBr pellet and obtain true powder pattern spectra. These spectra have been fully analyzed using spectral simulation software, and a complete set of spin Hamiltonian parameters has been determined for each complex. Both complexes are rigorously axial systems, with relatively low magnitude zero-field splitting: D approximately -2.3 cm(-)(1) and g values quite close to 2.00. Prior to this work, no experimental nor theoretical data exist for the metal-based electronic energy levels in Mn(III) complexes of porphyrinic ligands. This lack of information is in contrast to other transition metal complexes and is likely due to the dominance of ligand-based transitions in the absorption spectra of Mn(III) complexes of this type. We have therefore made use of theoretical values for the electronic energy levels of (phthalocyanato)copper(II), which electronically resembles these Mn(III) complexes. This analogy works surprisingly well in terms of the agreement between the calculated and experimentally determined EPR parameters. These results show a significant mixing of the triplet (S = 1) excited state with the quintet (S = 2) ground state in Mn(III) complexes with porphyrinic ligands. This is in agreement with the experimental observation of lower spin ground states in

  11. Use of spin labels to study membrane proteins by high-frequency electron nuclear double resonance spectroscopy

    NARCIS (Netherlands)

    Orlinkskii, S.B.; Borovykh, I.V.; Zielke, V.; Steinhoff, H.J.

    2007-01-01

    The applicability of spin labels to study membrane proteins by high-frequency electron nuclear double resonance spectroscopy is demonstrated. With the use of bacteriorhodopsin embedded in a lipid membrane as an example, the spectra of protons of neighboring amino acids are recorded, electric field

  12. Entrepreneurship and prior experience as antecedents of absorptive capacity of high-tech academic spin-offs

    NARCIS (Netherlands)

    Khodaei, H.; Scholten, V.; Wubben, E.F.M.; Omta, S.W.F.

    2016-01-01

    We investigate the influence of entrepreneurial orientation and team efficacy, in addition to the impact of domain-specific industry and research experience of spin-off management teams, on absorptive capacity, both potential and realised. A multiple regression analysis in 95 Dutch high-tech

  13. Ultrafast high harmonics for probing the fastest spin and charge dynamics in magnetic materials

    Science.gov (United States)

    Grychtol, Patrick

    2015-03-01

    Ultrafast light based on the high-harmonic up-conversion of femtosecond laser pulses have been successfully employed to access resonantly enhanced magnetic contrast at the Mabsorption edges of the 3d ferromagnets Fe, Co and Ni in a table-top setup. Thus, it has been possible to study element-specific dynamics in magnetic materials at femtosecond time scales in a laboratory environment, providing a wealth of opportunities for a greater fundamental understanding of correlated phenomena in solid-state matter. However, these investigations have so far been limited to linear polarized harmonics, since most techniques by which circular soft x-rays can be generated are highly inefficient reducing the photon flux to a level unfit for scientific applications. Besides presenting key findings of our ultrafast studies on charge and spin dynamics, we introduce a simple setup which allows for the efficient generation of circular harmonics bright enough for XMCD experiments. Our work thus represents a critical advance that enables element-specific imaging and spectroscopy of multiple elements simultaneously in magnetic and other chiral media with very high spatial and temporal resolution on the tabletop. In collboration with Ronny Knut, Emrah Turgut, Dmitriy Zusin, Christian Gentry, Henry Kapteyn, Margaret Murnane, JILA, University of Colorado, Boulder; Justin Shaw, Hans Nembach, Tom Silva, Electromagnetics Division, NIST, Boulder, CO; and Ofer Kfir, Avner Fleischer, Oren Cohen, Extreme Nonlinear Optics Group, Solid State Institute, Technion, Israel.

  14. Characteristics of Butanol Isomers Oxidation in a Micro Flow Reactor

    KAUST Repository

    Bin Hamzah, Muhamad Firdaus

    2017-05-01

    Ignition and combustion characteristics of n-butanol/air, 2-butanol.air and isobutanol/air mixtures at stoichiometric (ϕ = 1) and lean (ϕ = 0.5) conditions were investigated in a micro flow reactor with a controlled temperature profile from 323 K to 1313 K, under atmospheric pressure. Sole distinctive weak flame was observed for each mixture, with inlet fuel/air mixture velocity set low at 2 cm/s. One-dimensional computation with comprehensive chemistry and transport was conducted. At low mixture velocities, one-stage oxidation was confirmed from heat release rate profiles, which was broadly in agreement with the experimental results. The weak flame positions were congruent with literature describing reactivity of the butanol isomers. These weak flame responses were also found to mirror the trend in Anti-Knock Indexes of the butanol isomers. Flux and sensitivity analyses were performed to investigate the fuel oxidation pathways at low and high temperatures. Further computational investigations on oxidation of butanol isomers at higher pressure of 5 atm indicated two-stage oxidation through the heat release rate profiles. Low temperature chemistry is accentuated in the region near the first weak cool flame for oxidation under higher pressure, and its impact on key species – such as hydroxyl radical, hydrogen peroxide and carbon monoxide – were considered. Both experimental and computational findings demonstrate the advantage of employing the micro flow reactor in investigating oxidation processes in the temperature region of interest along the reactor channel. By varying physical conditions such as pressure, the micro flow reactor system is proven to be highly beneficial in elucidating oxidation behavior of butanol isomers in conditions in engines such as those that mirror HCCI operations.

  15. Isomers of nitric acid and chlorine nitrate

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, M.P.; Francl, M.M.; Rowland, F.S.; Hehre, W.J.

    1988-09-22

    Ab initio molecular orbital calculations at the HF/6-31G* and MP2/6-31G* levels have been performed on nitric acid and chlorine nitrate. Equilibrium geometries and electric dipole moments obtained from the MP2/6-31G* calculations are in good agreement with the respective experimental values, normal-mode (harmonic) vibrational frequencies and frequency shifts due to isotopic substitution calculated at this level support the most recent gas-phase infrared assignments for chlorine nitrate but suggest a reversal in the assignment of v/sub 5/ and v/sub 6/ for nitric acid. Calculations at the same levels of theory were also performed on peroxynitrous acid (HOONO) and chlorine peroxynitrite (ClOONO). The former is found to be 35 kcal/mol less stable than nitric acid at the MP2/6-31G* level; chlorine peroxynitrite is 30 kcal/mol higher in energy than chlorine nitrate. The possible role of these high-energy isomers in atmospheric processes is discussed.

  16. Electron spin resonance spectroscopy of high purity crystals at millikelvin temperatures

    Science.gov (United States)

    Farr, Warrick G.; Creedon, Daniel L.; Goryachev, Maxim; Benmessai, Karim; Tobar, Michael E.

    2013-12-01

    Progress in the emerging field of engineered quantum systems requires the development of devices that can act as quantum memories. The realisation of such devices by doping solid state cavities with paramagnetic ions imposes a trade-off between ion concentration and cavity coherence time. Here, we investigate an alternative approach involving interactions between photons and naturally occurring impurity ions in ultra-pure crystalline microwave cavities exhibiting exceptionally high quality factors. We implement a hybrid Whispering Gallery/Electron Spin Resonance method to perform rigorous spectroscopy of an undoped single-crystal sapphire resonator over the frequency range 8{19 GHz, and at external applied DC magnetic fields up to 0.9 T. Measurements of a high purity sapphire cooled close to 100 mK reveal the presence of Fe3+, Cr3+, and V2+ impurities. A host of electron transitions are measured and identified, including the two-photon classically forbidden quadrupole transition (Δms = 2) for Fe3+, as well as hyperfine transitions of V2+.

  17. Highly spin-polarized deuterium atoms from the UV dissociation of Deuterium Iodide

    CERN Document Server

    Sofikitis, D; Koumarianou, G; Jiang, H; Bougas, L; Samartzis, P C; Andreev, A; Rakitzis, T P

    2016-01-01

    Hyperpolarisation of deuterium (D) and tritium (T) nuclear spins increases the D-T fusion reaction rate by ~50%, thus lowering the breakeven limit for the achievement of self-sustained fusion, and controls the emission direction of the reaction products for improved reactor efficiency. However, the important D-D polarization-dependent fusion reaction has not yet been measured, due to the low density of conventional polarized deuterium beams of ~10$^{12}$ cm$^{-3}$, limited by collisions on the ms-timescale of production. Here we demonstrate that hyperpolarised D atoms are produced by the 270 nm photodissociation of deuterium iodide (DI), yielding ~60% nuclear D polarization after ~1.6 ns, ~10$^6$ times faster than conventional methods, allowing collision-limited densities of ~10$^{18}$ cm$^{-3}$. Such ultrahigh densities of polarized D atoms open the way for the study of high-signal polarized D-D reactions. We discuss the possibility of the production of high-density pulsed polarized beams, and of polarized D...

  18. High dynamic range magnetometry with a single nuclear spin in diamond

    Energy Technology Data Exchange (ETDEWEB)

    Waldherr, Gerald; Beck, Johannes; Neumann, Philipp; Nitsche, Matthias; Wrachtrup, Joerg [3. Physikalisches Institut, Universitaet Stuttgart, 70569 Stuttgart (Germany); Said, Ressa S. [Institut fuer Quanten-Informationsverarbeitung, Universitaet Ulm, 89081 Ulm (Germany); Twamley, Jason [Centre for Engineered Quantum Systems, Faculty of Science, Macquarie University, Sydney (Australia); Jelezko, Fedor [Institut fuer Quantenoptik, Universitaet Ulm, 89073 Ulm (Germany)

    2012-07-01

    Sensors based on the nitrogen-vacancy (NV) defect in diamond are being developed to measure weak magnetic and electric fields at nanoscale. However, such sensors rely on measurements of a shift in the Lamor frequency of the defect, so an accumulation of quantum phase causes the measurement signal to exhibit a periodic modulation. This means that the measurement time is either restricted to half of one oscillation period, which limits accuracy, or that the magnetic field range must be known in advance. Moreover, the precision increases only slowly, as T{sup -0.5}, with the measurement time T. We implement a quantum phase estimation algorithm on a single nuclear spin in diamond to combine both high sensitivity and high dynamic range. By achieving a scaling of the precision with time to T{sup -0.85}, we improve the sensitivity by a factor of 7.4, for an accessible field range of 16 mT, or alternatively, we improve the dynamic range by a factor of 130 for a sensitivity of 2.5 {mu}T/Hz{sup 0.5}. These methods are applicable to a variety of field detection schemes, and do not require entanglement.

  19. High-fidelity spin measurement on the nitrogen-vacancy center

    Science.gov (United States)

    Hanks, Michael; Trupke, Michael; Schmiedmayer, Jörg; Munro, William J.; Nemoto, Kae

    2017-10-01

    Nitrogen-vacancy (NV) centers in diamond are versatile candidates for many quantum information processing tasks, ranging from quantum imaging and sensing through to quantum communication and fault-tolerant quantum computers. Critical to almost every potential application is an efficient mechanism for the high fidelity readout of the state of the electronic and nuclear spins. Typically such readout has been achieved through an optically resonant fluorescence measurement, but the presence of decay through a meta-stable state will limit its efficiency to the order of 99%. While this is good enough for many applications, it is insufficient for large scale quantum networks and fault-tolerant computational tasks. Here we explore an alternative approach based on dipole induced transparency (state-dependent reflection) in an NV center cavity QED system, using the most recent knowledge of the NV center’s parameters to determine its feasibility, including the decay channels through the meta-stable subspace and photon ionization. We find that single-shot measurements above fault-tolerant thresholds should be available in the strong coupling regime for a wide range of cavity-center cooperativities, using a majority voting approach utilizing single photon detection. Furthermore, extremely high fidelity measurements are possible using weak optical pulses.

  20. The spin-half XXZ antiferromagnet on the square lattice revisited: A high-order coupled cluster treatment

    Science.gov (United States)

    Bishop, R. F.; Li, P. H. Y.; Zinke, R.; Darradi, R.; Richter, J.; Farnell, D. J. J.; Schulenburg, J.

    2017-04-01

    We use the coupled cluster method (CCM) to study the ground-state properties and lowest-lying triplet excited state of the spin-half XXZ antiferromagnet on the square lattice. The CCM is applied to it to high orders of approximation by using an efficient computer code that has been written by us and which has been implemented to run on massively parallelized computer platforms. We are able therefore to present precise data for the basic quantities of this model over a wide range of values for the anisotropy parameter Δ in the range - 1 ≤ Δ 1) regimes, where Δ → ∞ represents the Ising limit. We present results for the ground-state energy, the sublattice magnetization, the zero-field transverse magnetic susceptibility, the spin stiffness, and the triplet spin gap. Our results provide a useful yardstick against which other approximate methods and/or experimental studies of relevant antiferromagnetic square-lattice compounds may now compare their own results. We also focus particular attention on the behaviour of these parameters for the easy-axis system in the vicinity of the isotropic Heisenberg point (Δ = 1) , where the model undergoes a phase transition from a gapped state (for Δ > 1) to a gapless state (for Δ ≤ 1), and compare our results there with those from spin-wave theory (SWT). Interestingly, the nature of the criticality at Δ = 1 for the present model with spins of spin quantum number s =1/2 that is revealed by our CCM results seems to differ qualitatively from that predicted by SWT, which becomes exact only for its near-classical large-s counterpart.

  1. Multi-quasiparticle isomers and rotational bands in sup 1 sup 8 sup 1 Re

    CERN Document Server

    Pearson, C J; Purry, C S; Dracoulis, G D; Bayer, S; Byrne, A P; Kibedi, T; Kondev, F G

    2000-01-01

    High-spin states in sup 1 sup 8 sup 1 Re have been populated using the sup 1 sup 7 sup 6 Yb( sup 1 sup 1 B, 6n) reaction and their decays studied using the CAESAR gamma -ray spectrometer. Thirteen bands of rotational states have been observed based on 1-, 3- and 5-quasiparticle structures, including two new 5-quasiparticle isomers, with half-lives of 1.2 mu s and 22 ns. Angular correlation and distribution coefficients were obtained and gamma -ray intensity ratios were used to extract |g sub K -g sub R |/Q sub 0 ratios. Three K -forbidden decays were observed and their reduced hindrance factors were obtained and found to be consistent with known systematic behaviour. Band crossings were observed between 1- and 3-quasiparticle bands. These rotation-aligned 3-quasiparticle bands appear to have high K , and are identified as t -bands. Band mixing calculations support the assigned K -values. A unique degeneracy was observed for two I suppi=23/2 sup - states at 1883 keV.

  2. High-Frequency Dynamics Modulated by Collective Magnetization Reversal in Artificial Spin Ice

    Energy Technology Data Exchange (ETDEWEB)

    Jungfleisch, Matthias B.; Sklenar, Joseph; Ding, Junjia; Park, Jungsik; Pearson, John E.; Novosad, Valentine; Schiffer, Peter; Hoffmann, Axel

    2017-12-01

    Spin-torque ferromagnetic resonance arises in heavy metal-ferromagnet heterostructures when an alternating charge current is passed through the bilayer stack. The methodology to detect the resonance is based on the anisotropic magnetoresistance, which is the change in the electrical resistance due to different orientations of the magnetization. In connected networks of ferromagnetic nanowires, known as artificial spin ice, the magnetoresistance is rather complex owing to the underlying collective behavior of the geometrically frustrated magnetic domain structure. Here, we demonstrate spin-torque ferromagnetic resonance investigations in a square artificial spin-ice system and correlate our observations to magneto-transport measurements. The experimental findings are described using a simulation approach that highlights the importance of the correlated dynamics response of the magnetic system. Our results open the possibility of designing reconfigurable microwave oscillators and magnetoresistive devices based on connected networks of nanomagnets.

  3. FY1995 study of high density near-contact magnetic recording using spin valve head; 1995 nendo spin valve head ni yoru chokomitsudo near contact jiki kiroku no kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Development of high performance spin valves formed by amorphous magnetic layer and head-medium interface with nano-thickness molecular film for realizing an ultra-high density of 20 Gbit/in{sup 2} using contact recording. The giant magnetoresistance effect was investigated for spin valves using very thin amorphous magnetic layer. In amorphous-CoFeB/Cu/ Co spin valves, the maximum MR ratio of 6% was achieved at the thickness of the amorphous layer of 2 nm. The spin valves with the amorphous layer exhibit very good thermal stability. Design guideline for molecularly thin lubricant was established using newly derived lubrication equation considering lubricant porosity. Novel method for accurately measuring surface force due to molecularly thin lubricant was developed by using Michelson interferometry to detect cantilever displacement, which enabled two-dimensional transient force measurement. (NEDO)

  4. Optical cooling and trapping highly magnetic atoms: The benefits of a spontaneous spin polarization

    CERN Document Server

    Dreon, Davide; Bouazza, Chayma; Maineult, Wilfried; Dalibard, Jean; Nascimbene, Sylvain

    2016-01-01

    From the study of long-range-interacting systems to the simulation of gauge fields, open-shell Lanthanide atoms with their large magnetic moment and narrow optical transitions open novel directions in the field of ultracold quantum gases. As for other atomic species, the magneto-optical trap (MOT) is the working horse of experiments but its operation is challenging, due to the large electronic spin of the atoms. Here we present an experimental study of narrow-line Dysprosium MOTs. We show that the combination of radiation pressure and gravitational forces leads to a spontaneous polarization of the electronic spin. The spin composition is measured using a Stern-Gerlach separation of spin levels, revealing that the gas becomes almost fully spin-polarized for large laser frequency detunings. In this regime, we reach the optimal operation of the MOT, with samples of typically $3\\times 10^8$ atoms at a temperature of 20$\\,\\mu$K. The spin polarization reduces the complexity of the radiative cooling description, whi...

  5. High power all-metal spin torque oscillator using full Heusler Co{sub 2}(Fe,Mn)Si

    Energy Technology Data Exchange (ETDEWEB)

    Seki, Takeshi, E-mail: go-sai@imr.tohoku.ac.jp; Sakuraba, Yuya; Ueda, Masaki; Okura, Ryo; Takanashi, Koki [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Arai, Hiroko; Imamura, Hiroshi [Spintronics Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568 (Japan)

    2014-09-01

    We showed the high rf power (P{sub out}) emission from an all-metal spin torque oscillator (STO) with a Co{sub 2}Fe{sub 0.4}Mn{sub 0.6}Si (CFMS)/Ag/CFMS giant magnetoresistance (GMR) stack, which was attributable to the large GMR effect thanks to the highly spin-polarized CFMS. The oscillation spectra were measured by varying the magnetic field direction, and the perpendicular magnetic field was effective to increase P{sub out} and the Q factor. We simultaneously achieved a high output efficiency of 0.013%, a high Q of 1124, and large frequency tunability. CFMS-based all-metal STO is promising for overcoming the difficulties that conventional STOs are confronted with.

  6. Spin dynamics in high-mobility two-dimensional electron systems embedded in GaAs/AlGaAs quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Griesbeck, Michael

    2012-11-22

    Since many years there has been great effort to explore the spin dynamics in low-dimensional electron systems embedded in GaAs/AlGaAs based heterostructures for the purpose of quantum computation and spintronics applications. Advances in technology allow for the design of high quality and well-defined two-dimensional electron systems (2DES), which are perfectly suited for the study of the underlying physics that govern the dynamics of the electron spin system. In this work, spin dynamics in high-mobility 2DES is studied by means of the all-optical time-resolved Kerr/Faraday rotation technique. In (001)-grown 2DES, a strong in-plane spin dephasing anisotropy is studied, resulting from the interference of comparable Rashba and Dresselhaus contributions to the spin-orbit field (SOF). The dependence of this anisotropy on parameters like the confinement length of the 2DES, the sample temperature, as well as the electron density is demonstrated. Furthermore, coherent spin dynamics of an ensemble of ballistically moving electrons is studied without and within an applied weak magnetic field perpendicular to the sample plane, which forces the electrons to move on cyclotron orbits. Finally, strongly anisotropic spin dynamics is investigated in symmetric (110)-grown 2DES, using the resonant spin amplification method. Here, extremely long out-of-plane spin dephasing times can be achieved, in consequence of the special symmetry of the Dresselhaus SOF.

  7. High-Resolution Spin-on-Patterning of Perovskite Thin Films for a Multiplexed Image Sensor Array.

    Science.gov (United States)

    Lee, Woongchan; Lee, Jongha; Yun, Huiwon; Kim, Joonsoo; Park, Jinhong; Choi, Changsoon; Kim, Dong Chan; Seo, Hyunseon; Lee, Hakyong; Yu, Ji Woong; Lee, Won Bo; Kim, Dae-Hyeong

    2017-10-01

    Inorganic-organic hybrid perovskite thin films have attracted significant attention as an alternative to silicon in photon-absorbing devices mainly because of their superb optoelectronic properties. However, high-definition patterning of perovskite thin films, which is important for fabrication of the image sensor array, is hardly accomplished owing to their extreme instability in general photolithographic solvents. Here, a novel patterning process for perovskite thin films is described: the high-resolution spin-on-patterning (SoP) process. This fast and facile process is compatible with a variety of spin-coated perovskite materials and perovskite deposition techniques. The SoP process is successfully applied to develop a high-performance, ultrathin, and deformable perovskite-on-silicon multiplexed image sensor array, paving the road toward next-generation image sensor arrays. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Gas chromatography and silver-ion high-performance liquid chromatography analysis of conjugated linoleic acid isomers in free fatty acid form using sulphuric acid in methanol as catalyst.

    Science.gov (United States)

    Luna, Pilar; Juárez, Manuela; de la Fuente, Miguel Angel

    2008-09-12

    This study used GC and silver-ion HPLC to examine the effects of temperature and time on methylation of individual and mixtures of conjugated linoleic acid (CLA) isomers in free fatty acid form using sulphuric acid as catalyst. In the conditions tested (temperatures between 20 and 50 degrees C and times between 10 and 60 min) methylation was complete while avoiding isomerization of conjugated dienes and the formation of artefacts that could interfere with chromatographic determinations. An analytical method using solvent extraction of the lipids followed by selective elution of the free fatty acids from aminopropyl bonded phase columns and methylation with H(2)SO(4) in mild conditions was then applied to determine the CLA isomers in free fatty acid form in rumen fluid, and the results were evaluated.

  9. Spin State as a Marker for the Structural Evolution of Nature's Water-Splitting Catalyst.

    Science.gov (United States)

    Krewald, Vera; Retegan, Marius; Neese, Frank; Lubitz, Wolfgang; Pantazis, Dimitrios A; Cox, Nicholas

    2016-01-19

    In transition-metal complexes, the geometric structure is intimately connected with the spin state arising from magnetic coupling between the paramagnetic ions. The tetramanganese-calcium cofactor that catalyzes biological water oxidation in photosystem II cycles through five catalytic intermediates, each of which adopts a specific geometric and electronic structure and is thus characterized by a specific spin state. Here, we review spin-structure correlations in Nature's water-splitting catalyst. The catalytic cycle of the Mn4O5Ca cofactor can be described in terms of spin-dependent reactivity. The lower "inactive" S states of the catalyst, S0 and S1, are characterized by low-spin ground states, SGS = 1/2 and SGS = 0. This is connected to the "open cubane" topology of the inorganic core in these states. The S2 state exhibits structural and spin heterogeneity in the form of two interconvertible isomers and is identified as the spin-switching point of the catalytic cycle. The first S2 state form is an open cubane structure with a low-spin SGS = 1/2 ground state, whereas the other represents the first appearance of a closed cubane topology in the catalytic cycle that is associated with a higher-spin ground state of SGS = 5/2. It is only this higher-spin form of the S2 state that progresses to the "activated" S3 state of the catalyst. The structure of this final metastable catalytic state was resolved in a recent report, showing that all manganese ions are six-coordinate. The magnetic coupling is dominantly ferromagnetic, leading to a high-spin ground state of SGS = 3. The ability of the Mn4O5Ca cofactor to adopt two distinct structural and spin-state forms in the S2 state is critical for water binding in the S3 state, allowing spin-state crossing from the inactive, low-spin configuration of the catalyst to the activated, high-spin configuration. Here we describe how an understanding of the magnetic properties of the catalyst in all S states has allowed conclusions on

  10. Spin-sprayed ferrite films with high resistivity and high-frequency magnetic loss for GHz conducted noise suppressors

    Energy Technology Data Exchange (ETDEWEB)

    Subramani, A.K. [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama (Japan)], E-mail: subramani.aa@m.titech.ac.jp; Matsushita, N. [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama (Japan)], E-mail: matsushita@msl.titech.ac.jp; Watanabe, T. [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama (Japan); Tada, M.; Abe, M. [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8552 (Japan); Kondo, K. [NEC Tokin Corporation, 6-7-1 Koriyama, Taihaku-ku, Sendai, Miyagi 982-8510 (Japan); Yoshimura, M. [Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori, Yokohama (Japan)

    2008-02-25

    In the present study, crystallized ferrite (an intermediate between Fe{sub 3}O{sub 4} and {gamma}-Fe{sub 2}O{sub 3}) films prepared by spin-spray technique exhibited strong magnetic losses at high frequencies and are applicable as GHz conducted noise suppressors. The reaction (metal ions) and oxidizing (pH buffers and oxidizing agent) solutions were separately sprayed onto the substrates (90 deg. C) mounted on a rotating disc. Two types of films were prepared on the basis of the different oxidizing solutions; CH{sub 3}COONa + NaNO{sub 2} in the case of film-A and CH{sub 3}COONa + (NH{sub 4}){sub 2}CO{sub 3} + NaNO{sub 2} + NaOH for film-B. The as-prepared films were heat-treated under a condition similar to that of the reflow soldering process (265 deg. C). The effects of the preparation conditions and film morphology on the electrical and magnetic properties before and after the heat treatment were studied. The results revealed that film-B had a relatively smaller initial permeability ({mu}') compared to film-A. However, it had a high-imaginary permeability ({mu}''), resonance frequency (f{sub r}) and surface resistivity ({rho}{sub s}) even after heat treatment. Also, the noise suppressing properties of film-B were relatively good, hence ideal for use as conducted noise suppressors.

  11. Feeding of the 1 1/2- isomers in stable Ir and Au isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Fotiadis, Nikolaos [Los Alamos National Laboratory; Nelson, Ronald O [Los Alamos National Laboratory; Devlin, Matthew [Los Alamos National Laboratory; Holloway, Shannon T [Los Alamos National Laboratory; Kawano, Toshihiko [Los Alamos National Laboratory; Talou, Patrick [Los Alamos National Laboratory; Chadwick, Mark B [Los Alamos National Laboratory; Becker, John A [LLNL; Garrett, Paul E [U GUELPH, CANADA

    2008-01-01

    Excited states were studied and absolute partial {gamma}-ray cross sections were measured using the ({eta}, {eta}'{gamma}) reaction in {sup 191}Ir, {sup 193}Ir and {sup 197}Au. A Compton-suppressed germanium-detector array (GEANIE) for {gamma}-ray spectroscopy and the broad-spectrum pulsed neutron source of the Los Alamos Neutron Science Center's WNR facility were used for the measurement. The energy of the incident neutrons was determined using the time-of-flight technique. Absolute partial {gamma}-ray cross sections were measured up to incident neutron energy of 20 MeV for several transitions feeding directly the 1 1/2- isomers and ground states in {sup 191}Ir, {sup 193}Ir and {sup 197}Au. The feeding of the 1 1/2- isomers, which originate from the odd proton occupying the h{sub 1 1/2} orbital, was found for the three targets to be very similar and increasing relative to the feeding of the corresponding ground state with increasing neutron energy up to E{sub n} {approx} 10 MeV. Above this neutron energy the opening of the (n, 2{sub n}) reaction channel strongly affects the population of the isomers and leads to a decrease of their relative population compared to the population of the ground states. The experimental results are compared with theoretical predictions from the GNASH reaction model calculation implementing a version of the spin distribution for the pre-equilibrium reaction piece with either a compound nucleus spin distribution (CN-GNASH) or a Feshbach-Kerman-Koonin (FKK-GNASH) quantum mechanical spin distribution. The effects of the spin cutoff parameter values on the population of states are examined. Evidence is presented that FKK-GNASH provides a description of the experimental data that mitigates the need for adjustment of the level density parameter to fit the data.

  12. Feeding of the 11/2- isomers in stable Ir and Au isotopes

    Science.gov (United States)

    Fotiades, N.; Nelson, R. O.; Devlin, M.; Holloway, S.; Kawano, T.; Talou, P.; Chadwick, M. B.; Becker, J. A.; Garrett, P. E.

    2009-10-01

    Excited states in Ir191, Ir193, and Au197 were studied and absolute partial γ-ray cross sections were measured using the (n,n'γ) reaction. A Compton-suppressed germanium-detector array (GEANIE) for γ-ray spectroscopy was used for the measurement and the broad-spectrum pulsed neutron source of the Los Alamos Neutron Science Center’s WNR facility provided energetic neutrons. The energy of the incident neutrons was determined using the time-of-flight technique. Absolute partial γ-ray cross sections were measured up to incident neutron energy of 20 MeV for several transitions feeding directly the 11/2- isomers and ground states in Ir191, Ir193, and Au197. The feeding of the 11/2- isomers, which originate from the odd proton occupying the h11/2 orbital, was found for the three targets to be very similar and increasing relative to the feeding of the corresponding ground state with increasing neutron energy up to En~10 MeV. Above this neutron energy the opening of the (n,2n) reaction channel strongly affects the population of the isomers and leads to a decrease of their relative population compared to the population of the ground states. The experimental results are compared with theoretical predictions from the GNASH reaction model calculation implementing a version of the spin distribution for the pre-equilibrium reaction piece with either a compound nucleus spin distribution (CN-GNASH) or a Feshbach-Kerman-Koonin (FKK-GNASH) quantum mechanical spin distribution. The effects of the spin cutoff parameter values on the population of states are examined. Evidence is presented that FKK-GNASH provides a description of the experimental data that mitigates the need for adjustment of the level density parameter to fit the data.

  13. Introduction of Branching Degrees of Octane Isomers.

    Science.gov (United States)

    Perdih, Anton

    2016-01-01

    The concept of branching degrees is introduced. In the case of octane isomers it is derived from the values of a set of their physicochemical properties, calculating for each isomer the average of the normalized values and these averages are defined as branching degrees of octane isomers. The sequence of these branching degrees of octane isomers does not differ much from the »regular« one defined earlier. 2,2-Dimethylhexane appears to be less branched than 3,4-dimethylhexane and 3-ethyl, 2-methylpentane, whereas 2,3,4-trimethylpentane appears to be less branched than 3-ethyl, 3-methylpentane. While the increasing number of branches gives rise to increasing branching degrees, the peripheral position of branches and the separation between branches decreases the value of the branching degree. The central position of branches increases it. A bigger branch increases it more than a smaller one. The quantification of these structural features and their correlations with few indices is given as well.

  14. High-field study of the spin-Peierls system CuGeO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Regnault, L.P. [CEA Centre d`Etudes de Grenoble, 38 (France)

    1997-04-01

    The one-dimensional spin-1/2 Heisenberg antiferromagnetic system coupled to a three-dimensional phonon field undergoes a structural distortion below a finite temperature T{sub sp} (spin-Peierls transition) which induces the formation of a non-magnetic singlet ground-state and the opening of a gap in the excitation spectrum at the antiferromagnetic point. The recent discovery of the germanate CuGeO{sub 3} as a spin-Peierls system has considerably renewed the interest is this fascinating phenomenon. Inelastic neutron scattering and neutron diffraction have brought very quantitative pieces of information which can be directly compared to the predictions of the standard model. (author). 6 refs.

  15. Table of superdeformed nuclear bands and fission isomers

    Energy Technology Data Exchange (ETDEWEB)

    Firestone, R.B. [Lawrence Berkeley Lab., CA (United States); Singh, B. [McMaster Univ., Hamilton, ON (Canada)

    1994-06-01

    A minimum in the second potential well of deformed nuclei was predicted and the associated shell gaps are illustrated in the harmonic oscillator potential shell energy surface calculations shown in this report. A strong superdeformed minimum in {sup 152}Dy was predicted for {beta}{sub 2}-0.65. Subsequently, a discrete set of {gamma}-ray transitions in {sup 152}DY was observed and, assigned to the predicted superdeformed band. Extensive research at several laboratories has since focused on searching for other mass regions of large deformation. A new generation of {gamma}-ray detector arrays is already producing a wealth of information about the mechanisms for feeding and deexciting superdeformed bands. These bands have been found in three distinct regions near A=l30, 150, and 190. This research extends upon previous work in the actinide region near A=240 where fission isomers were identified and also associated with the second potential well. Quadrupole moment measurements for selected cases in each mass region are consistent with assigning the bands to excitations in the second local minimum. As part of our committment to maintain nuclear structure data as current as possible in the Evaluated Nuclear Structure Reference File (ENSDF) and the Table of Isotopes, we have updated the information on superdeformed nuclear bands. As of April 1994, we have complied data from 86 superdeformed bands and 46 fission isomers identified in 73 nuclides for this report. For each nuclide there is a complete level table listing both normal and superdeformed band assignments; level energy, spin, parity, half-life, magneto moments, decay branchings; and the energies, final levels, relative intensities, multipolarities, and mixing ratios for transitions deexciting each level. Mass excess, decay energies, and proton and neutron separation energies are also provided from the evaluation of Audi and Wapstra.

  16. Spin spring behavior in exchange coupled soft and high-coercivity hard ferromagnets.

    Energy Technology Data Exchange (ETDEWEB)

    Shull, R. D.; Shapiro, A. J.; Gornakov, V. S.; Nikitenko, V. I.; Jiang, J. S.; Kaper, H.; Leaf, G.; Bader, S. D.

    2000-11-01

    The magnetization reversal processes in an epitaxial Fe/Sm{sub 2}Co{sub 7} structure were investigated using the magneto-optical indicator film technique. The dependence of the magnitude and the orientation of the structure average magnetization have been studied on both cycling and rotating the external magnetic field. It was discovered that the magnetization reversal of the soft ferromagnet can proceed by formation of not only one-dimensional, but also two-dimensional, exchange spin springs. Experimental data is compared with a theoretical estimation of the rotational hysteresis loop for a spin system containing a one-dimensional exchange spring.

  17. Absence of high-temperature ballistic transport in the spin-1/2 XXX chain within the grand-canonical ensemble

    Science.gov (United States)

    Carmelo, J. M. P.; Prosen, T.

    2017-01-01

    Whether in the thermodynamic limit, vanishing magnetic field h → 0, and nonzero temperature the spin stiffness of the spin-1/2 XXX Heisenberg chain is finite or vanishes within the grand-canonical ensemble remains an unsolved and controversial issue, as different approaches yield contradictory results. Here we provide an upper bound on the stiffness and show that within that ensemble it vanishes for h → 0 in the thermodynamic limit of chain length L → ∞, at high temperatures T → ∞. Our approach uses a representation in terms of the L physical spins 1/2. For all configurations that generate the exact spin-S energy and momentum eigenstates such a configuration involves a number 2S of unpaired spins 1/2 in multiplet configurations and L - 2 S spins 1/2 that are paired within Msp = L / 2 - S spin-singlet pairs. The Bethe-ansatz strings of length n = 1 and n > 1 describe a single unbound spin-singlet pair and a configuration within which n pairs are bound, respectively. In the case of n > 1 pairs this holds both for ideal and deformed strings associated with n complex rapidities with the same real part. The use of such a spin 1/2 representation provides useful physical information on the problem under investigation in contrast to often less controllable numerical studies. Our results provide strong evidence for the absence of ballistic transport in the spin-1/2 XXX Heisenberg chain in the thermodynamic limit, for high temperatures T → ∞, vanishing magnetic field h → 0 and within the grand-canonical ensemble.

  18. Method for estimating spin-spin interactions from magnetization curves

    Science.gov (United States)

    Tamura, Ryo; Hukushima, Koji

    2017-02-01

    We develop a method to estimate the spin-spin interactions in the Hamiltonian from the observed magnetization curve by machine learning based on Bayesian inference. In our method, plausible spin-spin interactions are determined by maximizing the posterior distribution, which is the conditional probability of the spin-spin interactions in the Hamiltonian for a given magnetization curve with observation noise. The conditional probability is obtained with the Markov chain Monte Carlo simulations combined with an exchange Monte Carlo method. The efficiency of our method is tested using synthetic magnetization curve data, and the results show that spin-spin interactions are estimated with a high accuracy. In particular, the relevant terms of the spin-spin interactions are successfully selected from the redundant interaction candidates by the l1 regularization in the prior distribution.

  19. High accuracy of arterial spin labeling perfusion imaging in differentiation of pilomyxoid from pilocytic astrocytoma

    Energy Technology Data Exchange (ETDEWEB)

    Nabavizadeh, S.A.; Assadsangabi, R.; Hajmomenian, M.; Vossough, A. [Perelman School of Medicine of the University of Pennsylvania, Department of Radiology, Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Santi, M. [Perelman School of Medicine of the University of Pennsylvania, Department of Pathology, Children' s Hospital of Philadelphia, Philadelphia, PA (United States)

    2015-05-01

    Pilomyxoid astrocytoma (PMA) is a relatively new tumor entity which has been added to the 2007 WHO Classification of tumors of the central nervous system. The goal of this study is to utilize arterial spin labeling (ASL) perfusion imaging to differentiate PMA from pilocytic astrocytoma (PA). Pulsed ASL and conventional MRI sequences of patients with PMA and PA in the past 5 years were retrospectively evaluated. Patients with history of radiation or treatment with anti-angiogenic drugs were excluded. A total of 24 patients (9 PMA, 15 PA) were included. There were statistically significant differences between PMA and PA in mean tumor/gray matter (GM) cerebral blood flow (CBF) ratios (1.3 vs 0.4, p < 0.001) and maximum tumor/GM CBF ratio (2.3 vs 1, p < 0.001). Area under the receiver operating characteristic (ROC) curves for differentiation of PMA from PA was 0.91 using mean tumor CBF, 0.95 using mean tumor/GM CBF ratios, and 0.89 using maximum tumor/GM CBF. Using a threshold value of 0.91, the mean tumor/GM CBF ratio was able to diagnose PMA with 77 % sensitivity, 100 % specificity, and a threshold value of 0.7, provided 88 % sensitivity and 86 % specificity. There was no statistically significant difference between the two tumors in enhancement pattern (p = 0.33), internal architecture (p = 0.15), or apparent diffusion coefficient (ADC) values (p = 0.07). ASL imaging has high accuracy in differentiating PMA from PA. The result of this study may have important applications in prognostication and treatment planning especially in patients with less accessible tumors such as hypothalamic-chiasmatic gliomas. (orig.)

  20. Spin current

    CERN Document Server

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

    2012-01-01

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

  1. IN15 ultra-high-resolution spin-echo project. First experiment

    Energy Technology Data Exchange (ETDEWEB)

    Schleger, P.; Hayes, C. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); Kollmar, A. [Forschungszentrum Juelich GmbH (Germany)

    1997-04-01

    The IN15 project is a collaboration between the ILL, HMI (Berlin), and FZ (Juelich) to construct a spin-echo spectrometer with a fourier time-range surpassing half a microsecond. Three different operational modes are possible: normal, with neutron focusing, and time-of-flight. Present status of the project is described. (author). 3 refs.

  2. Structure of high spin states of 76Kr and 78Kr nuclei

    Indian Academy of Sciences (India)

    Following a fully self-consistent cranked Hartree-Fock-Bogoliubov (CHFB) approach with a pairing+quadrupole+hexadecapole model interaction Hamiltonian the structure of the yrast states of 76,78Kr nuclei is studied up to angular momentum = 24. Evolution of the shape with spin, and rotation alignment of proton as well ...

  3. Probing spin-polarized tunneling at high bias and temperature with a magnetic tunnel transistor

    NARCIS (Netherlands)

    Park, B.G.; Banerjee, T.; Min, B.C.; Sanderink, Johannes G.M.; Lodder, J.C.; Jansen, R.

    2005-01-01

    The magnetic tunnel transistor (MTT) is a three terminal hybrid device that consists of a tunnel emitter, a ferromagnetic (FM) base, and a semiconductor collector. In the MTT with a FM emitter and a single FM base, spin-polarized hot electrons are injected into the base by tunneling. After

  4. Estimating the spin diffusion length and the spin Hall angle from spin pumping induced inverse spin Hall voltages

    Science.gov (United States)

    Roy, Kuntal

    2017-11-01

    There exists considerable confusion in estimating the spin diffusion length of materials with high spin-orbit coupling from spin pumping experiments. For designing functional devices, it is important to determine the spin diffusion length with sufficient accuracy from experimental results. An inaccurate estimation of spin diffusion length also affects the estimation of other parameters (e.g., spin mixing conductance, spin Hall angle) concomitantly. The spin diffusion length for platinum (Pt) has been reported in the literature in a wide range of 0.5-14 nm, and in particular it is a constant value independent of Pt's thickness. Here, the key reasonings behind such a wide range of reported values of spin diffusion length have been identified comprehensively. In particular, it is shown here that a thickness-dependent conductivity and spin diffusion length is necessary to simultaneously match the experimental results of effective spin mixing conductance and inverse spin Hall voltage due to spin pumping. Such a thickness-dependent spin diffusion length is tantamount to the Elliott-Yafet spin relaxation mechanism, which bodes well for transitional metals. This conclusion is not altered even when there is significant interfacial spin memory loss. Furthermore, the variations in the estimated parameters are also studied, which is important for technological applications.

  5. CMOS patterning over high-aspect ratio topographies for N10/N7 using spin-on carbon hardmasks

    Science.gov (United States)

    Hopf, Toby; Ercken, Monique; Mannaert, Geert; Kunnen, Eddy; Tao, Zheng; Vandenbroeck, Nadia; Sebaai, Farid; Kikuchi, Yoshiaki; Mertens, Hans; Kubicek, Stefan; Demuynck, Steven; Horiguchi, Naoto

    2017-03-01

    In this paper proof-of-principle demonstrations of spin-on carbon (SOC)/spin-on glass (SOG)-based lithography processes which could replace standard patterning stacks within the FEOL for upcoming advanced nodes like N10/N7 are presented. At these dimensions the standard lithography approaches that have been utilized within the previous nodes will begin to run into fundamental limitations as a result of the extremely high aspect ratios of the device topography, requiring both new materials as well as new patterning flows in order to allow for continued device scaling. Here, novel SOC/SOG-based patterning flows have been demonstrated which could be applied to implement Source Drain Extension implantations and epitaxial growth processes for CMOS FinFET device architectures even down at N10/N7 dimensions.

  6. High-resolution resonant inelastic extreme ultraviolet scattering from orbital and spin excitations in a Heisenberg antiferromagnet

    Science.gov (United States)

    Caretta, Antonio; Dell'Angela, Martina; Chuang, Yi-De; Kalashnikova, Alexandra M.; Pisarev, Roman V.; Bossini, Davide; Hieke, Florian; Wurth, Wilfried; Casarin, Barbara; Ciprian, Roberta; Parmigiani, Fulvio; Wexler, Surge; Wray, L. Andrew; Malvestuto, Marco

    2017-11-01

    We report a high-resolution resonant inelastic extreme ultraviolet (EUV) scattering study of the quantum Heisenberg antiferromagnet KCoF3. By tuning the EUV photon energy to the cobalt M23 edge, a complete set of low-energy 3 d spin-orbital excitations is revealed. These low-lying electronic excitations are modeled using an extended multiplet-based mean-field calculation to identify the roles of lattice and magnetic degrees of freedom in modifying the resonant inelastic x-ray scattering (RIXS) spectral line shape. We have demonstrated that the temperature dependence of RIXS features upon the antiferromagnetic ordering transition enables us to probe the energetics of short-range spin correlations in this material.

  7. High-spin Mn-oxo complexes and their relevance to the oxygen-evolving complex within photosystem II.

    Science.gov (United States)

    Gupta, Rupal; Taguchi, Taketo; Lassalle-Kaiser, Benedikt; Bominaar, Emile L; Yano, Junko; Hendrich, Michael P; Borovik, A S

    2015-04-28

    The structural and electronic properties of a series of manganese complexes with terminal oxido ligands are described. The complexes span three different oxidation states at the manganese center (III-V), have similar molecular structures, and contain intramolecular hydrogen-bonding networks surrounding the Mn-oxo unit. Structural studies using X-ray absorption methods indicated that each complex is mononuclear and that oxidation occurs at the manganese centers, which is also supported by electron paramagnetic resonance (EPR) studies. This gives a high-spin Mn(V)-oxo complex and not a Mn(IV)-oxy radical as the most oxidized species. In addition, the EPR findings demonstrated that the Fermi contact term could experimentally substantiate the oxidation states at the manganese centers and the covalency in the metal-ligand bonding. Oxygen-17-labeled samples were used to determine spin density within the Mn-oxo unit, with the greatest delocalization occurring within the Mn(V)-oxo species (0.45 spins on the oxido ligand). The experimental results coupled with density functional theory studies show a large amount of covalency within the Mn-oxo bonds. Finally, these results are examined within the context of possible mechanisms associated with photosynthetic water oxidation; specifically, the possible identity of the proposed high valent Mn-oxo species that is postulated to form during turnover is discussed.

  8. High-spin Mn–oxo complexes and their relevance to the oxygen-evolving complex within photosystem II

    Science.gov (United States)

    Gupta, Rupal; Taguchi, Taketo; Lassalle-Kaiser, Benedikt; Bominaar, Emile L.; Yano, Junko; Hendrich, Michael P.; Borovik, A. S.

    2015-01-01

    The structural and electronic properties of a series of manganese complexes with terminal oxido ligands are described. The complexes span three different oxidation states at the manganese center (III–V), have similar molecular structures, and contain intramolecular hydrogen-bonding networks surrounding the Mn–oxo unit. Structural studies using X-ray absorption methods indicated that each complex is mononuclear and that oxidation occurs at the manganese centers, which is also supported by electron paramagnetic resonance (EPR) studies. This gives a high-spin MnV–oxo complex and not a MnIV–oxy radical as the most oxidized species. In addition, the EPR findings demonstrated that the Fermi contact term could experimentally substantiate the oxidation states at the manganese centers and the covalency in the metal–ligand bonding. Oxygen-17–labeled samples were used to determine spin density within the Mn–oxo unit, with the greatest delocalization occurring within the MnV–oxo species (0.45 spins on the oxido ligand). The experimental results coupled with density functional theory studies show a large amount of covalency within the Mn–oxo bonds. Finally, these results are examined within the context of possible mechanisms associated with photosynthetic water oxidation; specifically, the possible identity of the proposed high valent Mn–oxo species that is postulated to form during turnover is discussed. PMID:25852147

  9. Production cross sections for Lee-Wick massive electromagnetic bosons and for spin-zero and spin-one W bosons at high energies.

    Science.gov (United States)

    Linsker, R.

    1972-01-01

    Production cross sections for three types of hypothetical particles are calculated in the presented paper. Several (Z, Z') cases were studied corresponding to elastic scattering off protons and neutrons (either free or embedded within a Fermi sea), coherent scattering off a nucleus, and inelastic scattering off a proton (in which case Z' denotes a nucleon resonance or hadronic system in the continuum). Detailed structure-function data are used to improve the accuracy of the inelastic scattering calculation. Results of calculations are given for beam energies between 50 and 10,000 GeV, and masses between 5 and 40 GeV for the massive Lee-Wick spin-1 boson. Cross sections were computed for resonant and semiweak processes. The production cross section of spin-zero weak intermediate bosons was found to be at least one order of magnitude smaller than for spin-1 weak bosons in nearly all regions of interest. The production cross section of spin-zero weak intermediate bosons for inelastic scattering off protons compares with that for elastic scattering in the regions of interest. In the case of massive spin-1 bosons and spin-1 weak intermediates, the main contribution to total production cross section off protons is elastic.

  10. High-energy excited states in {sup 98}Cd

    Energy Technology Data Exchange (ETDEWEB)

    Blazhev, A; Braun, N; Jolie, J [Universitaet zu Koeln, Cologne (Germany); Grawe, H; Boutachkov, P; Gorska, M; Pietri, S; Domingo-Pardo, C; Kojouharov, I; Caceres, L; Engert, T; Farinon, F; Gerl, J; Goel, N [GSI, Darmstadt (Germany); Singh, B S Nara; Brock, T; Wadsworth, R [University of York, York (United Kingdom); Liu, Zh [University of Edinburgh, Edinburgh (United Kingdom); Nowacki, F [IPHC, Strasbourg (France); Grebosz, J, E-mail: a.blazhev@ikp.uni-koeln.d [IFJ PAN, Krakow (Poland)

    2010-01-01

    In {sup 98}Cd a new high-energy isomeric {gamma}-ray transition was identified, which confirms previous spin-parity assignments and enables for the first time the measurement of the E2 and E4 strength for the two decay branches of the isomer. Preliminary results on the {sup 98}Cd high-excitation level scheme are presented. A comparison to shell-model calculations as well as implications for the nuclear structure around {sup 100}Sn are discussed.

  11. High spin exotic states and new method for pairing energy; Etats exotiques a hauts spins et nouvelle methode pour l`energie d`appariement nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Molique, H.

    1996-01-19

    We present a new method called `PSY-MB`, initially developed in the framework of abstract group theory for the solution of the problem of strongly interacting multi-fermionic systems with particular to systems in an external rotating field. The validity of the new method (PSY-MB) is tested on model Hamiltonians. A detailed comparison between the obtained solutions and the exact ones is performed. The new method is used in the study of realistic nuclear Hamiltonians based on the Woods-Saxon potential within the cranking approximation to study the influence of residual monopole pairing interactions in the rare-earth mass region. In parallel with this new technique we present original results obtained with the Woods-Saxon mean-field and the self-consistent Hartree-Fock approximation in order to investigate such exotic effects as octupole deformations and hexadecapole C{sub 4}-polarizing deformations in the framework of high-spin physics. By developing these three approaches in one single work we prepare the ground for the nuclear structure calculations of the new generation - where the residual two-body interactions are taken into account also in the weak pairing limit. (author). 2370refs.

  12. High-spin {gamma}-ray spectroscopy of {sup 124}Ba, {sup 124}Xe and {sup 125}Xe

    Energy Technology Data Exchange (ETDEWEB)

    Al-Khatib, Ali

    2008-08-18

    Rotational spectra had been observed for the first time in excited atomic nuclei in 1938. This observation was attributed to the deviation from spherical shape. In quantum mechanics, when a perfectly spherical system rotates, it appears identical when it is viewed from any direction and no point of reference exists to which the change in position can be identified. Therefore, rotation cannot be defined for spherical nuclei. If the shape deviates from spherical symmetry, the nucleus can rotate and rotational spectra are observed. Many nucleons contribute to the rotation which is referred to as collective excitation. Depending on the mass region, nuclei have different deformations and, therefore, different shapes. Many nuclei show larger deformation with increasing excitation energy. Transitional nuclei between spherical and strongly deformed regions of the nuclear chart are usually soft with respect to deformation changes. In the mass region around A{proportional_to}125, which is the subject of this thesis, nuclei are predicted to be soft with respect to deformation. Rotational motion leads to Coriolis-induced alignments of high-j nucleons, which are in this mass region predominantly protons and neutrons from the h{sub 11/2} unique-parity intruder subshells. The proton Fermi level lies in the lower part of the h{sub 11/2} subshell which favours prolate shape whereas the neutron Fermi level lies in the upper part of the h{sub 11/2} subshell which favours oblate shape. According to the opposite shape-driving forces of protons and neutrons, shape co-existence is expected and the interplay between the h{sub 11/2} proton and neutron orbitals is of great interest for spectroscopic investigations. In addition, superdeformation has been established in this mass region. An interesting observation in this mass region is that nuclei undergo a shape-change from collective prolate to non-collective oblate states at high spins. In this spin range the transitions within the

  13. Solvent selectivity studies using isomers of polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    Men, L.C.; Na, H.; Rogers, L.B.

    1984-01-01

    The order of elution of isomeric trimers of polystyrene has been found to be independent of the dominant solvent-solute interaction as indicated by the location of the solvent in a Snyder triangle. The pure solvents were nitromethane, propylene carbonate, N-methylformamide, acetonitrile, the mixtures were trifluoroethanol with chloroform, methylene chloride and trichlorotrifluoroethane and also one of 2-methoxyethanol with water. Likewise, mixtures of acetonitrile with solvents near each of the corners of that triangle (chloroform, methylene chloride, and trifluoroethanol did not change the order of isomer elution). Substitution of trifluoroethanol for ethanol in mixtures with chloroform, methylene chloride, or trichlorotrifluoroethane led to improved isomer fractionations. 3 references, 5 figures, 2 tables.

  14. Comparison of 14 MeV isomer production of Hf-178m1 and Hf-179m2 using Feshbach-Kerman-Koonin and exciton preequilibrium models

    Science.gov (United States)

    Chadwick, M. B.; Young, P. G.

    The Hf-178m2(16+) isomeric state has a 31-yr half life and could pose serious radioactive problems in nuclear fusion reactors if its production in 14 MeV neutron-induced reactions is significant. We present statistical/pre-equilibrium model calculations for the production of this isomer in the Hf-179(n, 2n) Hf-178m2 reaction, as well as the 25-days 12.5(-) isomer in the Hf-179(n,n')Hf-179m2 reaction, using two different preequilibrium models: the exciton model and the Feshbach-Kerman-Koonin (FKK) theory. Our calculations which use the exciton model agree well with measurements, but those with the FKK theory underestimate measurements. Our calculations are the first to probe angular momentum transfer effects in the FKK theory and suggest that, as it is presently applied, high spin-transfer reactions are underestimated. We suggest modifications to the FKK statistical averaging procedure which may result in an improved agreement with experiment.

  15. Photon Self-Induced Spin to Orbital Conversion in TGG crystal at high laser power

    CERN Document Server

    Mosca, S; Karimi, E; Piccirillo, B; Marrucci, L; De Rosa, R; Genin, E; Milano, L; Santamato, E

    2010-01-01

    In this paper, we present experimental evidence of a newly discovered third-order nonlinear optical process Self-Induced Spin-to-Orbital Conversion (SISTOC) of the photon angular momentum. This effect is the physical mechanism at the origin of the depolarization of very intense laser beams propagating in isotropic materials. The SISTOC process, like self-focusing, is triggered by laser heating leading to a radial temperature gradient in the medium. In this work we tested the occurrence of SISTOC in a terbium gallium garnet (TGG) rod for an impinging laser power of about 100~W. To study the SISTOC process we used different techniques: polarization analysis, interferometry and tomography of the photon orbital angular momentum. Our results confirm, in particular, that the apparent depolarization of the beam is due to the occurrence of maximal entanglement between the spin and orbital angular momentum of the photons undergoing the SISTOC process. This explanation of the true nature of the depolarization mechanism...

  16. Spinning Them Off: Entrepreneuring practices in Corporate Spin-Offs

    National Research Council Canada - National Science Library

    Hydle, Katja Maria; Meland, Kjersti Vikse; Haus-Reve, Silje

    2016-01-01

    .... We uncover the enacted aspects of knowledge, called knowing, through theories from seven cases of incumbent-backed spin-offs and find that the management of the parent firms are highly involved in the spin-offs...

  17. Point contact Andreev reflection and the measurement of spin polarization: high fields and novel materials (Conference Presentation)

    Science.gov (United States)

    Stamenov, Plamen; Borisov, Kiril

    2016-10-01

    Point Contact Andreev Reflection (PCAR) is one of the few available methods for the determination of the Fermi level spin polarisation in metals and degenerate semiconductors. It has traditionally been applied at fixed (liquid He) temperatures, using pure niobium as the superconductor, and at essentially zero applied magnetic fields, all of which limit the amount of information that it can provide - i.e. do not allow for the extraction of the sign of the spin polarisation and make the assignment of the transport regime to ballistic or diffusive almost impossible. Here a series of experiments is described, aimed at the expansion of this parameter space to higher magnetic fields and to higher temperatures. These require redesigned experimental setups and the use of higher performance superconductors. Demonstrations are described of the determination of the sign of the spin polarisation, at fields of more than 5 Tesla using a low-Z superconductor, as well as operations beyond 9.2 K. Doubts about the practical reliability of the PCAR technique are dispersed using systematic series of samples - the heavy rare-earths and comparisons with alternatives, such as spin-polarised field emission, photo-emission and Tedrow-Meservey tunnelling. The specific material examples presented include 3d-metals, order-disorder transition alloys and zero-moment half-metals - Fe, FeAl and MnRuGa, alternative low-Z and high-Z superconductors - MgB2 and NbTi, and magnetic topological insulators, such as Cr- and V-doped (Bi1-xSbx)2Te3.

  18. Probing the Impact of Solvation on Photoexcited Spin Crossover Complexes with High-Precision X-ray Transient Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Cunming; Zhang, Jianxin [State; Lawson Daku, Latévi M. [Département; Gosztola, David; Canton, Sophie E. [ELI-ALPS, ELI-HU Non-Profit Ltd., Dugonics ter 13, Szeged 6720, Hungary; Attosecond; Zhang, Xiaoyi

    2017-11-17

    Investigating the photoinduced electronic and structural response of bistable molecular building blocks incorporating transition metals in solution phase constitutes a necessary stepping stone for steering their properties towards applications and perfomance optimizations. This work presents a detailed X-ray transient absorption (XTA) spectroscopy study of a prototypical spin crossover (SCO) complex [FeII(mbpy)3]2+ (where mbpy=4,4’-dimethyl-2,2’-bipyridine) with a [FeIIN6] first coordination shell in water (H2O) and acetonitrile (CH3CN). The unprecedented data quality of the XTA spectra together with the direct fitting of the difference spectra in k space using a large number of scattering paths enables resolving the subtle difference in the photoexcited structures of an FeII complex in two solvents for the first time. Compared to the low spin (LS) 1A1 state, the average Fe-N bond elongations for the photoinduced high spin (HS) 5T2 state are found to be 0.181 . 0.003 Å in H2O and 0.199 . 0.003 Å in CH3CN. This difference in structural response is attributed to ligand-solvent interactions that are stronger in H2O than in CH3CN for the HS excited state. Our studies demonstrate that, although the metal center of [FeII(mbpy)3]2+ could have been expected to be rather shielded by the three bidentate ligands with quasi-octahedral-coordination, the ligand field strength in the HS excited state is nevertheless indirectly affected by solvation that modifies the charge distribution within the Fe-N covalent bonds. More generally, this work highlights the importance of including solvation effects in order to develop a generalized understanding of the spin-state switching at the atomic level.

  19. Fabrication of highly spin-polarized Co2FeAl0.5Si0.5 thin-films

    Directory of Open Access Journals (Sweden)

    M. Vahidi

    2014-04-01

    Full Text Available Ferromagnetic Heusler Co2FeAl0.5Si0.5 epitaxial thin-films have been fabricated in the L21 structure with saturation magnetizations over 1200 emu/cm3. Andreev reflection measurements show that the spin polarization is as high as 80% in samples sputtered on unheated MgO (100 substrates and annealed at high temperatures. However, the spin polarization is considerably smaller in samples deposited on heated substrates.

  20. High-order standing spin wave modes in Fe{sub 19}Ni{sub 81} micron wire observed by homodyne method

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, A; Motoi, K; Miyajima, H [Department of Physics, Keio University, Hiyoshi, Yokohama 223-8522 (Japan); Uchiyama, T [Department of Electrical Engineering and Computer, Nagoya University, Chikusaku, Nagoya 464-8603 (Japan); Utsumi, Y, E-mail: yamaguch@phys.keio.ac.jp [Laboratory of Advanced Science and Technology fro Industry, University of Hyogo, Koto, Ako, Hyogo 678-1205 (Japan)

    2011-01-01

    The broadband spin dynamics of patterned ferromagnetic Fe{sub 19}Ni{sub 81} microwire with thickness of 80 nm has been investigated experimentally using broadband rectifying method. The rectifying effect provides a highly sensitive method to detect the high-order perpendicular standing spin wave (PSSW) mode. Present analytical calculation reproduces the observed relation between resonance frequency and applied magnetic field. The effective thickness is explained by the pinning condition of magnetic moment at the surface of the wire.

  1. Characterization of free radicals by electron spin resonance spectroscopy in biochars from pyrolysis at high heating rates and at high temperatures

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Jensen, Peter Arendt; Jensen, Anker Degn

    2016-01-01

    The concentration and type of free radicals from the decay (termination stage) of pyrolysis at slow and fast heating rates and at high temperatures (above 1000°C) in biomass char have been studied. A room temperature electron spin resonance spectroscopy study was conducted on original wood......, herbaceous biomass, holocelluloses, lignin and their chars, prepared at high temperatures in a wire mesh reactor, an entrained flow reactor, and a tubular reactor. The radical concentrations in the chars from the decay stage range up between 7·1016 and 1.5·1018 spins g -1. The results indicated....... The results show that at high temperatures, mostly aliphatic radicals (g = 2.0026-2.0028) and PAH radicals (g = 2.0027e2.0031) were formed....

  2. Higher Spin Matrix Models

    Directory of Open Access Journals (Sweden)

    Mauricio Valenzuela

    2017-10-01

    Full Text Available We propose a hybrid class of theories for higher spin gravity and matrix models, i.e., which handle simultaneously higher spin gravity fields and matrix models. The construction is similar to Vasiliev’s higher spin gravity, but part of the equations of motion are provided by the action principle of a matrix model. In particular, we construct a higher spin (gravity matrix model related to type IIB matrix models/string theory that have a well defined classical limit, and which is compatible with higher spin gravity in A d S space. As it has been suggested that higher spin gravity should be related to string theory in a high energy (tensionless regime, and, therefore to M-Theory, we expect that our construction will be useful to explore concrete connections.

  3. Spin conversion of cytochrome b{sub 559} in photosystem II induced by exogenous high potential quinone

    Energy Technology Data Exchange (ETDEWEB)

    Kropacheva, Tatyana N.; Feikema, W. Onno; Mamedov, Fikret; Feyziyev, Yashar; Styring, Stenbjorn; Hoff, Arnold J

    2003-11-01

    The spin-state of cytochrome b{sub 559} (Cyt b{sub 559}) was studied in photosystem II (PSII) membrane fragments by low-temperature EPR spectroscopy. Treatment of the membranes with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) converts the native low-spin (LS) form of Cyt b{sub 559} to the high-spin (HS) form characterized with the g= 6.19 and g= 5.95 split signal. The HS Cyt b{sub 559} was pH dependent with the amplitude increasing toward more acidic pH values (pH 5.5-8.5). The HS state was not photochemically active upon 77 and 200 K continuous illumination under our conditions and was characterized by a low reduction potential ({<=}0 V). It was also demonstrated that DDQ treatment damages the oxygen evolving complex, leading to inhibition of oxygen evolution, decrease of the S{sub 2}-state EPR multiline signal and release of Mn{sup 2+}. In parallel, studies of model systems containing iron(III) protoporphyrin IX chloride (Fe{sup III}Por), which is a good model compound for the Cyt b{sub 559} prosthetic group, were performed by using optical and EPR spectroscopy. The interaction of Fe{sup III}Por with imidazole (Im) in weakly polar solvent results in formation of bis-imidazole coordinated heme iron (Fe{sup III}Por Im{sub 2}) which mimic the bis-histidine axial ligation of Cyt b{sub 559}. The reaction of DDQ with the LS Fe{sup III}Por Im{sub 2} complex leads to its transformation into the HS state (g{sub perpendicular}=5.95, g{sub parallel}=2.00). It was shown that the spin conversion occurs due to the donor-acceptor interaction of coordinated imidazole with this high-potential quinone causing the displacement of imidazole from the axial position. The similar mechanism of DDQ-induced spin change is assumed to be valid for the native membrane Cyt b{sub 559} in PSII centers.

  4. Chemical profile of beans cultivars (Phaseolus vulgaris) by 1H NMR - high resolution magic angle spinning (HR-MAS);Perfil quimico de cultivares de feijao (Phaseolus vulgaris) pela tecnica de high resolution magic angle spinning (HR-MAS)

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Luciano Morais; Choze, Rafael; Cavalcante, Pedro Paulo Araujo; Santos, Suzana da Costa; Ferri, Pedro Henrique, E-mail: luciano@quimica.ufg.b [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Inst. de Quimica; Ferreira, Antonio Gilberto [Universidade Federal de Sao Carlos (UFScar), SP (Brazil). Dept. de Quimica

    2010-07-01

    The application of one-dimensional proton high-resolution magic angle spinning ({sup 1}H HR-MAS) NMR combined with a typical advantages of solid and liquid-state NMR techniques was used as input variables for the multivariate statistical analysis. In this paper, different cultivars of beans (Phaseolus vulgaris) developed and in development by EMBRAPA - Arroz e Feijao were analyzed by {sup 1}H HR-MAS, which have been demonstrated to be a valuable tool in its differentiation according chemical composition and avoid the manipulation of the samples as used in other techniques. (author)

  5. Fixed-bed adsorption separation of xylene isomers over sio2/silicallite-1 core-shell adsorbents

    KAUST Repository

    Khan, Easir A.

    2013-12-29

    SiO2/Silicalite-1 core-shell material has been demonstrated as potential shape selective adsorbent in gas phase separation of p-xylene from a mixture of p/o-xylene isomers. The core-shell composite comprised of large silica core and thin polycrystalline silicalite-1 shell which was synthesized via a self-assembly of silicalite-1 nanocrystals on core silica surface followed by a secondary seeded growth method. The core materials, SiO2 used in this study has mesoporosity with an average pore diameter of 60Å and hence offers no shape selectivity for xylene isomers. However, the shell, silicalite-1 contains rigid pore structures and preferentially adsorbs p-xylene from their isomers mixtures. A series of adsorption fixed bed breakthrough adsorption/desorption experiment was performed to obtain the equilibrium isotherms and adsorption isotherm parameters of xylene isomers. The equilibrium isotherms of xylene isomers follow the Langmuir\\'s model. A chromatographic adsorption model has been used to describe the fixed-bed breakthrough profiles of xylene isomers. The model has successfully predicted the responses of the binary mixtures of p/o-xylene isomers. The SiO2/silicalite-1 core-shell adsorbents have shown para-selectivity as high as 15. © Bangladesh Uni. of Engg. & Tech.

  6. Measurements of nuclear spin dynamics by spin-noise spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhov, I. I.; Poltavtsev, S. V.; Kozlov, G. G.; Zapasskii, V. S. [Spin Optics Laboratory, St. Petersburg State University, 1 Ul' anovskaya, Peterhof, St. Petersburg 198504 (Russian Federation); Kavokin, K. V.; Glazov, M. M. [Spin Optics Laboratory, St. Petersburg State University, 1 Ul' anovskaya, Peterhof, St. Petersburg 198504 (Russian Federation); Ioffe Institute, Russian Academy of Sciences, 26 Polytechnicheskaya, St.-Petersburg 194021 (Russian Federation); Vladimirova, M.; Scalbert, D.; Cronenberger, S. [Laboratoire Charles Coulomb UMR 5221 CNRS/Université de Montpellier, Place Eugene Bataillon, 34095 Montpellier Cedex 05 (France); Kavokin, A. V. [Spin Optics Laboratory, St. Petersburg State University, 1 Ul' anovskaya, Peterhof, St. Petersburg 198504 (Russian Federation); School of Physics and Astronomy, University of Southampton, SO17 1NJ Southampton (United Kingdom); Lemaître, A.; Bloch, J. [Laboratoire de Photonique et de Nanostructures, UPR CNRS, Route de Nozay, 91460 Marcoussis (France)

    2015-06-15

    We exploit the potential of the spin noise spectroscopy (SNS) for studies of nuclear spin dynamics in n-GaAs. The SNS experiments were performed on bulk n-type GaAs layers embedded into a high-finesse microcavity at negative detuning. In our experiments, nuclear spin polarisation initially prepared by optical pumping is monitored in real time via a shift of the peak position in the electron spin noise spectrum. We demonstrate that this shift is a direct measure of the Overhauser field acting on the electron spin. The dynamics of nuclear spin is shown to be strongly dependent on the electron concentration.

  7. Theoretical studies on nuclear spin selective quantum dynamics of non-linear molecules; Theoretische Untersuchung zur Quantendynamik der Kernspinisomere nicht-linearer Molekuele

    Energy Technology Data Exchange (ETDEWEB)

    Grohmann, Thomas

    2012-05-31

    In this thesis the wave packet dynamics of nuclear spin isomers of polyatomic molecules after interaction with static and time-dependent magnetic fields and moderate intense nonresonant laser pulses is investigated. In particular, the process of inducing (internal) molecular rotation as well as alignment of molecules by manipulating their rotational or rotational-torsional degrees of freedom is studied. In the first part of the thesis all theoretical concepts for identifying nuclear spin isomers and for describing their quantum dynamics will be discussed. Especially the symmetrization postulate and themolecular symmetry group will be introduced and illustrated for some examples of molecules. These concepts will be extended to the case of identifying nuclear spin isomers in the presence of an external field. In the second part it is shown for nitromethane that magnetic fields are able to induce unidirectional rotations in opposite directions for different nuclear spin isomers of molecules containing methyl groups if the dipolar interaction is included. Additionally, it is demonstrated that different nuclear spin isomers of a chemical compound may show different alignment after the interaction with a moderate intense laser pulse. As shown for the rigid symmetric top propadien and the rigid asymmetric tops ethene and analogues, distinct pairs of nuclear spin isomers show at certain points in time a complementary behavior: while one isomer is showing alignment the partner isomer is showing anti-alignment. Moreover, it is illustrated that not every nuclear spin isomer can be aligned equally efficient. The alignment of non-rigid molecules is considered as well. As an example for a molecule with feasible torsion in the electronic ground state, the alignment of diboron tetrafluoride is investigated. It becomes apparent that not only rotational but also the torsional dynamics of the molecules is nuclear spin selective; different nuclear spin isomers have at distinct points

  8. Coexistence of magnetic fluctuations and superconductivity in the pnictide high temperature superconductor SmFeAsO1-xFx measured by muon spin rotation.

    Science.gov (United States)

    Drew, A J; Pratt, F L; Lancaster, T; Blundell, S J; Baker, P J; Liu, R H; Wu, G; Chen, X H; Watanabe, I; Malik, V K; Dubroka, A; Kim, K W; Rössle, M; Bernhard, C

    2008-08-29

    Muon spin rotation experiments were performed on the pnictide high temperature superconductor SmFeAsO1-xFx with x=0.18 and 0.3. We observed an unusual enhancement of slow spin fluctuations in the vicinity of the superconducting transition which suggests that the spin fluctuations contribute to the formation of an unconventional superconducting state. An estimate of the in-plane penetration depth lambda ab(0)=190(5) nm was obtained, which confirms that the pnictide superconductors obey an Uemura-style relationship between Tc and lambda ab(0);(-2).

  9. Isomer profiles of perfluoroalkyl substances in water and soil surrounding a chinese fluorochemical manufacturing park.

    Science.gov (United States)

    Jin, Hangbiao; Zhang, Yifeng; Zhu, Lingyan; Martin, Jonathan W

    2015-04-21

    Despite that China is the largest global manufacturer of perfluoroalkyl substances (PFASs), the manufacturing methods and isomer purity of these chemicals are generally unknown. Here, sampling was conducted around a major fluorochemical manufacturing park in China in 2012, including soil and water collection inside the park, including from a wastewater treatment plant (WWTP), as well as in surrounding rivers and soil (∼15 km radius). Perfluoroalkyl sulfonates (PFSAs) were lower than perfluoroalkyl carboxylates (PFCAs) in all samples, and short-chain (C4-C6) PFCAs were predominant. Perfluoroalkyl phosphonates and phosphate diesters were occasionally detected, but at low detection frequency. Branched isomers of perfluorobutanesulfonate (PFBS) are reported for the first time, accounting for 15-27% of total PFBS in water. An enrichment of isopropyl-PFOA (28%) was found in WWTP influent, suggesting its manufacturing primarily by isopropyl telomerization. More numerous branched isomers were observed for the longer C9-C13 PFCAs (e.g., C12 PFCA had 16 branched isomers), including high proportions of one major branched isomer (likely isopropyl), possibly as impurities from isopropyl-PFOA manufacturing. Overall, short-chain perfluorinated acids were the predominant PFASs being released, but PFOA was still a major chemical in use at this site, primarily from isopropyl telomerization.

  10. Theoretical investigation on isomer formation probability and free energy of small C clusters

    Science.gov (United States)

    Lin, Zheng-Zhe

    2015-06-01

    Molecular dynamics simulations and free energy calculations are employed to investigate the evolution, formation probability, detailed balance, and isomerization rate of small C cluster isomer at 2500 K. For C10, the isomer formation probability predicted by free energy is in good agreement with molecular dynamics simulation. However, for C20, C30, and C36, the formation probabilities predicted by free energy are not in agreement with molecular dynamics simulations. Although the cluster systems are in equilibrium, detailed balance is not reached. Such results may be attributed to high transformation barriers between cage, bowl, and sheet isomers. In summary, for mesoscopic nanosystems the free energy criterion, which commonly holds for macroscopic systems in dynamic equilibrium, may not provide a good prediction for isomer formation probability. New theoretical criterion should be further investigated for predicting the isomer formation probability of a mesoscopic nanosystem. Project supported by the National Natural Science Foundation of China (Grant No. 11304239) and the Fundamental Research Funds for the Central Universities.

  11. Multiple-quantum magic-angle spinning: high-resolution solid state NMR spectroscopy of half-integer quadrupolar nuclei

    CERN Document Server

    Goldbourt, A

    2002-01-01

    Experimental and theoretical aspects of the multiple-quantum magic-angle spinning experiment (MQMAS) are discussed in this review. The significance of this experiment, introduced by Frydman and Harwood, is in its ability to provide high-resolution NMR spectra of half-integer quadrupolar nuclei (I /geq 3/2). This technique has proved to be useful in various systems ranging from inorganic materials to biological samples. This review addresses the development of various pulse schemes aimed at improving the signal-to-noise ratio and anisotropic lineshapes. Representative spectra are shown to underscore the importance and applications of the MQMAS experiment. Refs. 97 (author)

  12. Low-lying levels and high-spin band structures in sup 1 sup 0 sup 2 Rh

    CERN Document Server

    Gizon, J; Timar, J; Cata-Danil, G; Nyakó, B M; Zolnai, L; Boston, A J; Joss, D T; Paul, E S; Semple, A T; O'Brien, N J; Parry, C M; Bucurescu, D; Brant, S; Paar, V

    1999-01-01

    Levels in sup 1 sup 0 sup 2 Rh have been populated in the reaction sup 7 sup 0 Zn+ sup 3 sup 6 S at 130 MeV. The level structure of sup 1 sup 0 sup 2 Rh has been investigated using the EUROGAM II array. Low-lying states and four high-spin bands have been identified. The configurations of low-lying levels and two-quasiparticle bands are interpreted in the frame of the interacting boson-fermion-fermion model. The four observed band structures are also compared with cranked shell model calculations using a modified oscillator potential.

  13. Magic angle spinning nuclear magnetic resonance apparatus and process for high-resolution in situ investigations

    Science.gov (United States)

    Hu, Jian Zhi; Sears, Jr., Jesse A.; Hoyt, David W.; Mehta, Hardeep S.; Peden, Charles H. F.

    2015-11-24

    A continuous-flow (CF) magic angle sample spinning (CF-MAS) NMR rotor and probe are described for investigating reaction dynamics, stable intermediates/transition states, and mechanisms of catalytic reactions in situ. The rotor includes a sample chamber of a flow-through design with a large sample volume that delivers a flow of reactants through a catalyst bed contained within the sample cell allowing in-situ investigations of reactants and products. Flow through the sample chamber improves diffusion of reactants and products through the catalyst. The large volume of the sample chamber enhances sensitivity permitting in situ .sup.13C CF-MAS studies at natural abundance.

  14. Intra-arterial high signals on arterial spin labeling perfusion images predict the occluded internal carotid artery segment

    Energy Technology Data Exchange (ETDEWEB)

    Sogabe, Shu; Satomi, Junichiro; Tada, Yoshiteru; Kanematsu, Yasuhisa; Kuwayama, Kazuyuki; Yagi, Kenji; Yoshioka, Shotaro; Mizobuchi, Yoshifumi; Mure, Hideo; Yamaguchi, Izumi; Kitazato, Keiko T.; Nagahiro, Shinji [Tokushima University Graduate School, Department of Neurosurgery, Tokushima (Japan); Abe, Takashi; Harada, Masafumi [Tokushima University Graduate School, Department of Radiology, Tokushima (Japan); Yamamoto, Nobuaki; Kaji, Ryuji [Tokushima University Graduate School, Department of Clinical Neurosciences, Institute of Biomedical Biosciences, Tokushima (Japan)

    2017-06-15

    Arterial spin labeling (ASL) involves perfusion imaging using the inverted magnetization of arterial water. If the arterial arrival times are longer than the post-labeling delay, labeled spins are visible on ASL images as bright, high intra-arterial signals (IASs); such signals were found within occluded vessels of patients with acute ischemic stroke. The identification of the occluded segment in the internal carotid artery (ICA) is crucial for endovascular treatment. We tested our hypothesis that high IASs on ASL images can predict the occluded segment. Our study included 13 patients with acute ICA occlusion who had undergone angiographic and ASL studies within 48 h of onset. We retrospectively identified the high IAS on ASL images and angiograms and recorded the occluded segment and the number of high IAS-positive slices on ASL images. The ICA segments were classified as cervical (C1), petrous (C2), cavernous (C3), and supraclinoid (C4). Of seven patients with intracranial ICA occlusion, five demonstrated high IASs at C1-C2, suggesting that high IASs could identify stagnant flow proximal to the occluded segment. Among six patients with extracranial ICA occlusion, five presented with high IASs at C3-C4, suggesting that signals could identify the collateral flow via the ophthalmic artery. None had high IASs at C1-C2. The mean number of high IAS-positive slices was significantly higher in patients with intra- than extracranial ICA occlusion. High IASs on ASL images can identify slow stagnant and collateral flow through the ophthalmic artery in patients with acute ICA occlusion and help to predict the occlusion site. (orig.)

  15. Study of the separation method of structural isomer using Magneto-Archimedes method

    Energy Technology Data Exchange (ETDEWEB)

    Mori, T.; Kobayadhi, T.; Mishima, F.; Akiyama, Y.; Nishijima, Shigehiro [Osaka University, Osaka (Japan)

    2016-03-15

    Organic compounds have a problem that the separation of structural isomer in the preparation process requires high energy consumption. This study proposes a new separation method of structural isomer using Magneto- Archimedes method. Firstly, the levitation height of 1, 6-DDA and 1, 10-DDA was respectively calculated by simulation of the forces acting on the particles under magnetic field, and it was indicated that they could be separated by the difference of levitation height. To confirm the phenomenon experimentally, white powders of 1, 6-DDA and 1, 10-DDA were formed into pellets, and were soaked in manganese chloride solution. Then the solution was put on the center of the cryostat of HTS bulk magnet (maximum magnetic flux density is 3T). As a result, it was confirmed that the separation of structural isomer by difference of levitation height could be possible.

  16. Energy distributions at the high-spin ferric sites in myoglobin crystals.

    Science.gov (United States)

    Fiamingo, F G; Brill, A S; Hampton, D A; Thorkildsen, R

    1989-01-01

    The orientation and temperature dependence (4.2-2.5 K) of electron paramagnetic resonance (EPR) power saturation and spin-lattice relaxation rate, and the orientation dependence of signal linewidth, were measured in single crystals of the aquo complex of ferric sperm whale skeletal muscle myoglobin. The spin-packet linewidth was found to be temperature independent and to vary by a factor of seven within the heme plane. An analysis is presented which enables one to arrive at (a) hyperfine component line-widths and, from the in-plane angular variation of the latter, at (b) the widths of distributions in energy differences between low-lying electronic levels and (c) the angular spread in the in-plane principal g-directions. The values of the energy level distributions in crystals obtained from the measurements and analysis reported here are compared with those obtained by a different method for the same protein complex in frozen solution. The spread in the rhombic energy splitting is significantly greater in solution than in the crystal. PMID:2539208

  17. Analytical high-order post-Newtonian expansions for spinning extreme mass ratio binaries

    CERN Document Server

    Kavanagh, Chris; Wardell, Barry

    2016-01-01

    We present an analytic computation of Detweiler's redshift invariant for a point mass in a circular orbit around a Kerr black hole, giving results up to 8.5 post-Newtonian order while making no assumptions on the magnitude of the spin of the black hole. Our calculation is based on the functional series method of Mano, Suzuki and Takasugi, and employs a rigorous mode-sum regularization prescription based on the Detweiler-Whiting singular-regular decomposition. The approximations used in our approach are minimal; we use the standard self-force expansion to linear order in the mass ratio, and the standard post-Newtonian expansion in the separation of the binary. A key advantage of this approach is that it produces expressions that include contributions at all orders in the spin of the Kerr black hole. While this work applies the method to the specific case of Detweiler's redshift invariant, it can be readily extended to other gauge invariant quantities and to higher post-Newtonian orders.

  18. Effects of impurities and vortices on the low-energy spin excitations in high-Tc materials

    DEFF Research Database (Denmark)

    Andersen, Brian Møller; Graser, S.; Schmid, M.

    2011-01-01

    a quasi-long range ordered state. When correlations are sufficiently strong, disorder is unimportant for the generation of static magnetism but plays an additional role of pinning disordered stripe configurations. We calculate the spin excitations in a disordered spin-density wave phase, and show how...... disorder and/or applied magnetic fields lead to a slowing down of the dynamical spin fluctuations in agreement with neutron scattering and muon spin rotation (mSR) experiments....

  19. PREFACE: Spin Electronics

    Science.gov (United States)

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

    2007-04-01

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

  20. A Counterflow Diffusion Flame Study Of Branched Octane Isomers

    Science.gov (United States)

    2012-09-26

    public release; distribution is unlimited. A counterflow diffusion flame study of branched octane isomers The views, opinions and/or findings contained...MC 0934 La Jolla, CA 92093 -0934 ABSTRACT A counterflow diffusion flame study of branched octane isomers Report Title Conventional petroleum, Fischer...counterflow diffusion flame study of branched octane isomers Approved for public release; distribution is unlimited. 61657.7-EG REPORT DOCUMENTATION PAGE

  1. The interstellar chemistry of H2C3O isomers.

    Science.gov (United States)

    Loison, Jean-Christophe; Agúndez, Marcelino; Marcelino, Núria; Wakelam, Valentine; Hickson, Kevin M; Cernicharo, José; Gerin, Maryvonne; Roueff, Evelyne; Guélin, Michel

    2016-03-11

    We present the detection of two H2C3O isomers, propynal and cyclopropenone, toward various starless cores and molecular clouds, together with upper limits for the third isomer propadienone. We review the processes controlling the abundances of H2C3O isomers in interstellar media showing that the reactions involved are gas-phase ones. We show that the abundances of these species are controlled by kinetic rather than thermodynamic effects.

  2. Study of spin-exchange optically pumped {sup 3}He cells with high polarisation and long lifetimes

    Energy Technology Data Exchange (ETDEWEB)

    Parnell, S.R. [Academic Unit of Radiology, University of Sheffield, Sheffield S10 2JF (United Kingdom); ISIS Neutron and Muon Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom)], E-mail: s.r.parnell@sheffield.ac.uk; Babcock, E. [Insitut Laue-Langevin, 6, rue J. Horowitz, F-38042 Grenoble Cedex 9 (France); Nuenighoff, K. [Institut fuer Festkoerperforschung, Forschungszentrum Juelich, 52425 Juelich (Germany); Skoda, M.W.A.; Boag, S. [ISIS Neutron and Muon Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Masalovich, S. [Neutronenforschungsquelle Heinz Maier-Leibnitz, Technische Universitaet Muenchen, Lichtenbergstr, 1, 85747 Garching (Germany); Chen, W.C. [National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899 (United States); Georgii, R. [Neutronenforschungsquelle Heinz Maier-Leibnitz, Technische Universitaet Muenchen, Lichtenbergstr, 1, 85747 Garching (Germany); Wild, J.M. [Academic Unit of Radiology, University of Sheffield, Sheffield S10 2JF (United Kingdom); Frost, C.D. [ISIS Neutron and Muon Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom)

    2009-01-21

    We present a detailed investigation into {sup 3}He neutron spin filter cells polarised by spin exchange optical pumping (SEOP). We include measurements of the absolute {sup 3}He polarisation using neutron transmission and characterisation of both the X-factor and {sup 3}He relaxation times (T{sub 1}) for a number of cells. For one cell we calculated a maximum {sup 3}He polarisation of 79% with a T{sub 1} of 633 h. The measured X-factor of this cell, X=0.17{+-}0.01, is low. For all cells polarisations of >71% are observed. In addition we present {sup 3}He relaxation data for a new design of magneto-static cavity with a field of high homogeneity {delta}B/B{sub 0}{approx}3.5x10{sup -4}cm{sup -1}. This compact device provides a magnetic field in an orientation suitable for in situ optical pumping that minimises the field inhomogeneity contribution to the T{sub 1} to 930 h in a 1 bar cell, the longest reported on beam thus far. The results suggest that high {sup 3}He polarisation with long relaxation times can now be routinely obtained with SEOP, enabling time independent incident beam polarisation to be easily implemented across many different neutron scattering instruments.

  3. Longitudinal double spin asymmetries in single hadron quasi-real photoproduction at high pT

    Directory of Open Access Journals (Sweden)

    C. Adolph

    2016-02-01

    Full Text Available We measured the longitudinal double spin asymmetries ALL for single hadron muoproduction off protons and deuterons at photon virtuality Q2<1(GeV/c2 for transverse hadron momenta pT in the range 1 GeV/c to 4 GeV/c. They were determined using COMPASS data taken with a polarised muon beam of 160 GeV/c or 200 GeV/c impinging on polarised 6LiD or NH3 targets. The experimental asymmetries are compared to next-to-leading order pQCD calculations, and are sensitive to the gluon polarisation ΔG inside the nucleon in the range of the nucleon momentum fraction carried by gluons 0.05

  4. Longitudinal double spin asymmetries in single hadron quasi-real photoproduction at high $p_T$

    CERN Document Server

    Adolph, C; Alexeev, M G; Alexeev, G D; Amoroso, A; Andrieux, V; Anosov, V; Augustyniak, W; Austregesilo, A; Azevedo, C D R; Badełek, B; Balestra, F; Barth, J; Beck, R; Bedfer, Y; Bernhard, J; Bicker, K; Bielert, E R; Birsa, R; Bisplinghoff, J; Bodlak, M; Boer, M; Bordalo, P; Bradamante, F; Braun, C; Bressan, A; Büchele, M; Burtin, E; Chang, W-C; Chiosso, M; Choi, I; Chung, S U; Cicuttin, A; Crespo, M L; Curiel, Q; Dalla Torre, S; Dasgupta, S S; Dasgupta, S; Denisov, O Yu; Dhara, L; Donskov, S V; Doshita, N; Duic, V; Dünnweber, W; Dziewiecki, M; Efremov, A; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Finger, M; Finger jr , M; Fischer, H; Franco, C; du Fresne von Hohenesche, N; Friedrich, J M; Frolov, V; Fuchey, E; Gautheron, F; Gavrichtchouk, O P; Gerassimov, S; Giordano, F; Gnesi, I; Gorzellik, M; Grabmüller, S; Grasso, A; Grosse Perdekamp, M; Grube, B; Grussenmeyer, T; Guskov, A; Haas, F; Hahne, D; von Harrach, D; Hashimoto, R; Heinsius, F H; Herrmann, F; Hinterberger, F; Horikawa, N; d'Hose, N; Hsieh, C-Y; Huber, S; Ishimoto, S; Ivanov, A; Ivanshin, Yu; Iwata, T; Jahn, R; Jary, V; Joosten, R; Jörg, P; Kabuß, E; Ketzer, B; Khaustov, G V; Khokhlov, Yu A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koivuniemi, J H; Kolosov, V N; Kondo, K; Königsmann, K; Konorov, I; Konstantinov, V F; Kotzinian, A M; Kouznetsov, O; Krämer, M; Kremser, P; Krinner, F; Kroumchtein, Z V; Kuchinski, N; Kuhn, R; Kunne, F; Kurek, K; Kurjata, R P; Lednev, A A; Lehmann, A; Levillain, M; Levorato, S; Lichtenstadt, J; Longo, R; Maggiora, A; Magnon, A; Makins, N; Makke, N; Mallot, G K; Marchand, C; Marianski, B; Martin, A; Marzec, J; Matoušek, J; Matsuda, H; Matsuda, T; Meshcheryakov, G; Meyer, W; Michigami, T; Mikhailov, Yu V; Miyachi, Y; Montuenga, P; Nagaytsev, A; Nerling, F; Neyret, D; Nikolaenko, V I; Nový, J; Nowak, W-D; Nukazuka, G; Nunes, A S; Olshevsky, A G; Orlov, I; Ostrick, M; Panzieri, D; Parsamyan, B; Paul, S; Peng, J-C; Pereira, F; Pešek, M; Peshekhonov, D V; Platchkov, S; Pochodzalla, J; Polyakov, V A; Pretz, J; Quaresma, M; Quintans, C; Ramos, S; Regali, C; Reicherz, G; Riedl, C; Rossiyskaya, N S; Ryabchikov, D I; Rychter, A; Samoylenko, V D; Sandacz, A; Santos, C; Sarkar, S; Savin, I A; Sbrizzai, G; Schiavon, P; Schmidt, K; Schmieden, H; Schönning, K; Schopferer, S; Selyunin, A; Shevchenko, O Yu; Silva, L; Sinha, L; Sirtl, S; Slunecka, M; Sozzi, F; Srnka, A; Stolarski, M; Sulc, M; Suzuki, H; Szabelski, A; Szameitat, T; Sznajder, P; Takekawa, S; Tessaro, S; Tessarotto, F; Thibaud, F; Tosello, F; Tskhay, V; Uhl, S; Veloso, J; Virius, M; Weisrock, T; Wilfert, M; ter Wolbeek, J; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zink, A

    2016-01-01

    We measured the longitudinal double spin asymmetries $A_{LL}$ for single hadron muo-production off protons and deuterons at photon virtuality $Q^2$ < 1(GeV/$\\it c$)$^2$ for transverse hadron momenta $p_T$ in the range 0.7 GeV/$\\it c$ to 4 GeV/$\\it c$ . They were determined using COMPASS data taken with a polarised muon beam of 160 GeV/$\\it c$ or 200 GeV/$\\it c$ impinging on polarised $\\mathrm{{}^6LiD}$ or $\\mathrm{NH_3}$ targets. The experimental asymmetries are compared to next-to-leading order pQCD calculations, and are sensitive to the gluon polarisation $\\Delta G$ inside the nucleon in the range of the nucleon momentum fraction carried by gluons $0.05 < x_g < 0.2$.

  5. Pressure-induced hysteresis in the high spin {r_reversible} low spin transition in bis(2,4-bis(pyridin-2-yl)thiazole) iron(II) tetrafluoroborate

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, A; Ksenofontov, V; Guetlich, P [Institut fuer Anorganische Chemie und Analytische Chemie, Johannes-Gutenberg Universitaet, D-55099 Mainz (Germany); Goodwin, H A [School of Chemistry, University of New South Wales, Sydney, NSW 2052 (Australia)], E-mail: ashis.bhattacharjee@visva-bharati.ac.in, E-mail: guetlich@uni-mainz.de

    2009-01-14

    Studies of the spin transition behavior of the mononuclear compound [Fe(pythiaz){sub 2}](BF{sub 4}){sub 2} have been carried out under hydrostatic pressures up to 9.13 kbar in the 5-300 K temperature range. Under ambient pressure this compound exhibits an approximately half-step (incomplete) HS {r_reversible} LS transition with T{sub 1/2} = 146 K without any thermal hysteresis. At pressures up to 4.5 kbar the behavior remains similar but with an upward displacement of T{sub 1/2} and a slight decrease in the residual high spin fraction at low T. Application of higher pressures resulted in an almost complete two-step spin transition with several unusual pressure effects. Along with the expected pressure dependence of T{sub 1/2} the surprising appearance of hysteresis in the spin transition curves was observed. It is suggested that the likely origin of this unprecedented behavior is a pressure-induced structural change.

  6. Pressure-induced hysteresis in the high spin [Formula: see text] low spin transition in bis(2,4-bis(pyridin-2-yl)thiazole) iron(II) tetrafluoroborate.

    Science.gov (United States)

    Bhattacharjee, A; Ksenofontov, V; Goodwin, H A; Gütlich, P

    2009-01-14

    Studies of the spin transition behavior of the mononuclear compound [Fe(pythiaz)(2)](BF(4))(2) have been carried out under hydrostatic pressures up to 9.13 kbar in the 5-300 K temperature range. Under ambient pressure this compound exhibits an approximately half-step (incomplete) HS [Formula: see text] LS transition with T(1/2) = 146 K without any thermal hysteresis. At pressures up to 4.5 kbar the behavior remains similar but with an upward displacement of T(1/2) and a slight decrease in the residual high spin fraction at low T. Application of higher pressures resulted in an almost complete two-step spin transition with several unusual pressure effects. Along with the expected pressure dependence of T(1/2) the surprising appearance of hysteresis in the spin transition curves was observed. It is suggested that the likely origin of this unprecedented behavior is a pressure-induced structural change.

  7. New Isomers in the Neutron-Rich Region Beyond 208Pb

    Directory of Open Access Journals (Sweden)

    Gottardo A.

    2014-03-01

    Full Text Available The region of neutron-rich nuclei beyond 208Pb has been very difficult to explore due to its high mass and exoticity. However, recent experimental improvements allowed one to perform a quite extended isomer decay spectroscopy of these nuclei.

  8. Stability Computations for Isomers of La@Cn (n = 72, 74, 76

    Directory of Open Access Journals (Sweden)

    Ludwik Adamowicz

    2012-11-01

    Full Text Available Density-functional theory calculations are presented for low-energy La@C72, La@C74 and La@C76 isomers with IPR (isolated pentagon rule and non-IPR cages. The relative isomeric production yields at high temperatures are evaluated using the calculated terms, and the relationships to observations are discussed.

  9. Spin-flipping polarized electrons

    Directory of Open Access Journals (Sweden)

    V. S. Morozov

    2001-10-01

    Full Text Available We recently used a prototype rf dipole magnet to study the spin flipping of a 669 MeV horizontally polarized electron beam stored in the presence of a nearly full Siberian snake in the new MIT-Bates storage ring. We flipped the spin by ramping the rf dipole's frequency through an rf-induced depolarizing resonance. After optimizing the frequency ramp parameters, we used multiple spin flipping to measure a spin-flip efficiency of 94.5±2.5%. The spin-flip efficiency was apparently limited by the field strength in the air-core prototype rf dipole magnet. This unexpectedly high efficiency indicates that very efficient spin flipping of the ring's stored polarized electron beam should be possible using the much stronger ferrite spin flipper, which is now being built by the University of Michigan's Spin Physics Center.

  10. Control over the magnetism and transition between high- and low-spin states of an adatom on trilayer graphene.

    Science.gov (United States)

    Zheng, Anmin; Gao, Guoying; Huang, Hai; Gao, Jinhua; Yao, Kailun

    2017-05-31

    Using density-functional theory, we investigate the electronic and magnetic properties of an adatom (Na, Cu and Fe) on ABA- and ABC-stacked (Bernal and rhombohedral) trilayer graphenes. In particular, we study the influence of an applied gate voltage on magnetism, as it modifies the electronic states of the trilayer graphene (TLG) as well as changes the adatom spin states. Our study performed for a choice of three different adatoms (Na, Cu, and Fe) shows that the nature of adatom-graphene bonding evolves from ionic to covalent in moving from an alkali metal (Na) to a transition metal (Cu or Fe). Applying an external electric field (EEF) to TLG systems with different stacking orders results in the transition between high- and low-spin states in the latter case (Cu, Fe) and induces a little of magnetism in the former (Na) without magnetism in the absence of an external electric field. Our study would be useful for controlled adatom magnetism and (organic) spintronic applications in nanotechnology.

  11. Spin-glass behavior in YCo 10- xNi xSi 2 with high Ni content

    Science.gov (United States)

    Tang, H.; Qiao, G. W.; Liu, J. P.; Sellmyer, D. J.; de Boer, F. R.; Buschow, K. H. J.

    2001-02-01

    The magnetic properties and the structure of YCo 10- xNi xSi 2 alloys with high Ni content have been investigated by means of measurements of X-ray diffraction, dc magnetization and ac-susceptibility. The samples are basically of single phase (with x=6, 7, 8, 8.5, 9, 10) and adopt the ThMn 12 type structure. With x≤7.0, the samples show ferromagnetic behavior below the Curie temperatures. For compounds YCo 2Ni 8Si 2 and YCo 1.5Ni 8.5Si 2, the ac-susceptibility and dc zero-field cooling (ZFC) M( T) curve show a cusp with decreasing temperature, and the dc ZFC and field cooling (FC) M( T) curves in lower fields exhibit thermal irreversibility at low temperatures. The magnetization curves at temperatures below the cusp temperature on the ZFC branches do not saturate in the field range of H≤55 kOe. Furthermore, the hysteresis loops at temperatures below the cusp temperature exhibit no coercivity after ZFC. All these features suggest a spin-glass ordering of the compounds YCo 10- xNi xSi 2 with x equal to 8 and 8.5. The spin-glass behavior can be understood in terms of a competition between ferromagnetic interactions involving close Co-Co neighbors and antiferromagnetic interactions involving more remote Co-Co neighbors.

  12. Antiferromagnetic spin Seebeck effect.

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-03

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

  13. Antiferromagnetic Spin Seebeck Effect.

    Science.gov (United States)

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

    2016-03-04

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

  14. A simple and economical strategy for obtaining calibration plots for relative quantification of positional isomers of YYX/YXY triglycerides using high-performance liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Judge, Elizabeth J; Zheng, Dong; Chivukula, Swathilekha; Gakwaya, Robert; Schostarez, Sarah; Li, Xingwen; Liriano, Melissa; Evans, Jason J

    2017-10-30

    Positional analysis of intact triglycerides could provide greater insights into the link between fatty acid position and lipotoxic diseases. However, this methodology has been impeded by lack of commercial availability of positionally pure triglycerides. This work reports on a strategy for defining calibration plots for YXY/YYX triglyceride systems based on the product ion intensities in the collision-induced dissociation spectra of ammoniated precursor ions. A set of triglycerides were synthesized and analyzed by electrospray ionization tandem mass spectrometry using an ion trap mass spectrometer. The product ion spectra of the ammoniated precursor ions were collected for 42 triglyceride systems of the form YXY/YYX, where Y represents C16:0 , C18:1(c-9) and C20:4(cccc-5,8,11,14) . Three-point calibration plots were prepared by plotting the relative abundance of the YY(+) product ion vs. the relative abundance of the YYX positional isomer. The calibration plots were shown to give relative abundances of positional isomers accurate to within ±0.02 for most systems. Using an ion trap, under a controlled set of collision parameters, the slopes of the calibration plots can be used to compare the sensitivities of the product ion intensities to fatty acid position for various triglyceride systems. The average slopes of the calibration plots for the C16:0 , C18:1(c-9) and C20:4(cccc-5,8,11,14) systems were 0.29 ± 0.05, 0.21 ± 0.05 and 0.045 ± 0.005, respectively. While the presence of multiple unsaturated fatty acids tends to slightly decrease the slopes of the calibration plots, the data suggest that the sensitivities are sufficient for performing positional analysis of most triglyceride systems. However, the presence of unsaturated fatty acids that contain double bonds close to the carbonyl group, such as arachidonic acid, tends to dramatically decrease positional sensitivity. Copyright © 2017 John Wiley & Sons, Ltd.

  15. Synthesis and immune response of non-native isomers of vascular endothelial growth factor.

    Science.gov (United States)

    Jiang, Chuantao; Xiong, Wei; Lu, Bao-Yuan; Gonda, Matthew A; Chang, Jui-Yoa

    2010-08-10

    Native proteins often lack immunogenicity and thus limit vaccine and mAb development. We described here a unique method to enhance the immunogenicity of native proteins. This is achieved by creating non-native isomers of disulfide proteins (X-isomers) using the method of disulfide scrambling. X-isomers have the potential to be developed as vaccines and effective immunogens, as they are capable of breaking the immune tolerance and eliciting antibodies that cross-react with the native protein. In this report, we describe production of X-isomers of vascular endothelial growth factor (X-VEGF). The aim is to develop X-VEGF for cancer immunotherapy targeting reduction of VEGF. The production of mouse X-VEGF is achieved by expressing the short version of VEGF (1-110) commonly shared by all VEGF isoforms, with two Cys --> Ala mutations at Cys(51) and Cys(60) to generate R-VEGF(110) (R stands for fully reduced). R-VEGF(110) was then allowed to undergo oxidative folding in the absence of denaturant to form N-VEGF(110) (N stands for native) or in the presence of denaturant to generate five fractions of X-VEGF(110) isomers. While N-VEGF(110) exhibits only marginal immunogenicity in mice, all five fractions of X-VEGF(110) isomers were shown to elicit high titers of antibodies that cross-react with N-VEGF(110). In sera of immunized mice, the amounts of anti-N-VEGF antibodies elicited by X-VEGF(110) isomers range from 54 to 186 mug/mL, which are compatible with or greater than the concentration required for effective therapy using anti-VEGF MAbs. The underlying mechanism of enhanced immunogenicity of X-VEGF(110) is investigated and elaborated. These data suggest that X-VEGF(110) isomers are potential compounds in developing active immunotherapy for treatment of VEGFR bearing tumors and the wet form of age-related macular degeneration.

  16. Spin Injection in Indium Arsenide

    Directory of Open Access Journals (Sweden)

    Mark eJohnson

    2015-08-01

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

  17. Spin current

    CERN Document Server

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

    2017-01-01

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

  18. Evidences and perspectives in the utilization of CLNA isomers as bioactive compounds in foods.

    Science.gov (United States)

    Fontes, Ana L; Pimentel, Lígia L; Simões, Catarina D; Gomes, Ana M P; Rodríguez-Alcalá, Luís M

    2017-08-13

    Conjugated alpha linolenic acid (CLNA) isomers are promising lipids owing to their similarities with conjugated linoleic acid (CLA) but exerting their bioactivity at lower doses; some isomers also belong to omega 3 family. This review aims to summarize the state of the art about the utilization of CLNA as a functional ingredient. Indeed, in vitro and in vivo studies reported that CLNA exerted anticancer, anti-inflammatory, anti-obese, and antioxidant activities. However, CLNA has not been tested in humans. These compounds are naturally present in meat and milk fat from ruminants but the highest concentrations are found in vegetable oils. Their incorporation in foodstuffs is one of the most effective strategies to elaborate CLNA-enriched products together with the microbiological production. Lactobacilli, propionibacteria, and bifidobacteria strains have been assayed to produce CLNA isomers but at the current moment there are not high CLNA concentration products elaborated using these strains. Furthermore, it is known that CLNA isomers are highly prone to oxidation when compared with linoleic acid and CLA, but the possible effects of elaboration and storage on high CLNA productsare unknown.The utilization of CLNA as a functional compound still remains a challenge and requires more research to address all of its technological and bioactivity aspects.

  19. Magnetism and the spin state in cubic perovskite CaCo O3 synthesized under high pressure

    Science.gov (United States)

    Xia, Hailiang; Dai, Jianhong; Xu, Yuanji; Yin, Yunyu; Wang, Xiao; Liu, Zhehong; Liu, Min; McGuire, Michael A.; Li, Xiang; Li, Zongyao; Jin, Changqing; Yang, Yifeng; Zhou, Jianshi; Long, Youwen

    2017-07-01

    Cubic SrCo O3 with an intermediate spin state can only be stabilized by high pressure and high temperature (HPHT) treatment. It is metallic and ferromagnetic with the highest Curie temperature of the transition-metal perovskites. The chemical substitution by Ca on Sr sites would normally lower crystal symmetry from cubic to orthorhombic as seen in the perovskite family of Ca M O3 (M =M4 + of transition metals, G e4 + , S n4 + , and Z r4 + ) at room temperature. This structural change narrows the bandwidth, so as to further enhance the Curie temperature as the crossover to the localized electronic state is approached. We report a successful synthesis of the perovskite CaCo O3 with a HPHT treatment. Surprisingly, CaCo O3 crystallizes in a simple cubic structure that remains stable down to 20 K, the lowest temperature in the structural study. The new perovskite has been thoroughly characterized by a suite of measurements including transport, magnetization, specific heat, thermal conductivity, and thermoelectric power. Metallic CaCo O3 undergoes two successive magnetic transitions at 86 K and 54 K as temperature decreases. The magnetization at 5 K is compatible with the intermediate spin state t4e1 of C o4 + at the octahedral site. The thermal expansion of the Co-O bond length indicates that the population of high spin state t3e2 increases for T >100 K . The shortest Co-O bond length in cubic CaCo O3 is responsible for delocalizing electrons in the π*-band and itinerant-electron ferromagnetism at T <54 K . A comprehensive comparison between SrCo O3 and CaCo O3 and the justification of their physical properties by first-principles calculation have also been made in this report. Partially filled π* and σ* bands would make CaCo O3 suitable to study the Hund's coupling effect in a metal.

  20. Fundamental Issues Related to the Origin of Melatonin and Melatonin Isomers during Evolution: Relation to Their Biological Functions

    Directory of Open Access Journals (Sweden)

    Dun-Xian Tan

    2014-09-01

    Full Text Available Melatonin and melatonin isomers exist and/or coexist in living organisms including yeasts, bacteria and plants. The levels of melatonin isomers are significantly higher than that of melatonin in some plants and in several fermented products such as in wine and bread. Currently, there are no reports documenting the presence of melatonin isomers in vertebrates. From an evolutionary point of view, it is unlikely that melatonin isomers do not exist in vertebrates. On the other hand, large quantities of the microbial flora exist in the gut of the vertebrates. These microorganisms frequently exchange materials with the host. Melatonin isomers, which are produced by these organisms inevitably enter the host’s system. The origins of melatonin and its isomers can be traced back to photosynthetic bacteria and other primitive unicellular organisms. Since some of these bacteria are believed to be the precursors of mitochondria and chloroplasts these cellular organelles may be the primary sites of melatonin production in animals or in plants, respectively. Phylogenic analysis based on its rate-limiting synthetic enzyme, serotonin N-acetyltransferase (SNAT, indicates its multiple origins during evolution. Therefore, it is likely that melatonin and its isomer are also present in the domain of archaea, which perhaps require these molecules to protect them against hostile environments including extremely high or low temperature. Evidence indicates that the initial and primary function of melatonin and its isomers was to serve as the first-line of defence against oxidative stress and all other functions were acquired during evolution either by the process of adoption or by the extension of its antioxidative capacity.

  1. A practical chemo-enzymatic approach to highly enantio-enriched 10-ethyl-7,8-dihydro-γ-ionone isomers: a method for the synthesis of 4,5-didehydro-α-ionone.

    Science.gov (United States)

    Barakat, Assem; Al-Majid, Abdullah M; Mabkhot, Yahia Nasser; Al-Othman, Zeid Abdullah

    2012-01-01

    An efficient and convenient strategy for the enantioselective synthesis of enantiomerically enriched 10-ethyl-7,8-dihydro-γ-ionone isomers (R)-(+)-7, and (S)-(-)-7 are described utilizing a lipase mediated resolution protocol, and reductive elimination of the secondary allylic alcohol as the key step. The enantioselective and diastereoselective lipase kinetic acetylation of 4-hydroxy-γ-ionone derivatives 6a afforded the 4-acetyl-γ-ionone derivatives (-)-8, and the 4-hydrox-γ-ionone derivatives (+)-6a, which are suitable precursors of the desired products. Stereospecific palladium-mediated elimination of allylic acetate provides the target compounds with an excellent enantiomeric excess and yield. Additionally, the novel 4,5-didehydro-α-ionone 13 is obtained from readily prepared (2,6,6-trimethylcyclohexa-2,4-dien-1-yl) methanol 9. The structures of all newly synthesized compounds have been elucidated by (1)H, (13)C NMR, GC-MS, and IR spectrometry. These compounds represent a new class of odorants that may be of pivotal relevance in industrial perfumery.

  2. A Practical Chemo-enzymatic Approach to Highly Enantio-Enriched 10-Ethyl-7,8-dihydro-γ-ionone Isomers: A Method for the Synthesis of 4,5-Didehydro-α-Ionone

    Directory of Open Access Journals (Sweden)

    Zeid Abdullah Al-Othman

    2012-05-01

    Full Text Available An efficient and convenient strategy for the enantioselective synthesis of enantiomerically enriched 10-ethyl-7,8-dihydro-γ-ionone isomers (R-(+-7, and (S-(−-7 are described utilizing a lipase mediated resolution protocol, and reductive elimination of the secondary allylic alcohol as the key step. The enantioselective and diastereoselective lipase kinetic acetylation of 4-hydroxy-γ-ionone derivatives 6a afforded the 4-acetyl-γ-ionone derivatives (−-8, and the 4-hydrox-γ-ionone derivatives (+-6a, which are suitable precursors of the desired products. Stereospecific palladium-mediated elimination of allylic acetate provides the target compounds with an excellent enantiomeric excess and yield. Additionally, the novel 4,5-didehydro-α-ionone 13 is obtained from readily prepared (2,6,6-trimethylcyclohexa-2,4-dien-1-yl methanol 9. The structures of all newly synthesized compounds have been elucidated by 1H, 13C NMR, GC-MS, and IR spectrometry. These compounds represent a new class of odorants that may be of pivotal relevance in industrial perfumery.

  3. Spin multiplicities

    Energy Technology Data Exchange (ETDEWEB)

    Curtright, T.L., E-mail: curtright@miami.edu [Department of Physics, University of Miami, Coral Gables, FL 33124-8046 (United States); Van Kortryk, T.S., E-mail: vankortryk@gmail.com [Department of Physics, University of Miami, Coral Gables, FL 33124-8046 (United States); High Energy Physics Division, Argonne National Laboratory, Argonne, IL 60439-4815 (United States); Zachos, C.K., E-mail: zachos@anl.gov [Department of Physics, University of Miami, Coral Gables, FL 33124-8046 (United States); High Energy Physics Division, Argonne National Laboratory, Argonne, IL 60439-4815 (United States)

    2017-02-05

    The number of times spin s appears in the Kronecker product of n spin j representations is computed, and the large n asymptotic behavior of the result is obtained. Applications are briefly sketched. - Highlights: • We give a self-contained derivation of the spin multiplicities that occur in n-fold tensor products of spin-j representations. • We make use of group characters, properties of special functions, and asymptotic analysis of integrals. • We emphasize patterns that arise when comparing different values of j, and asymptotic behavior for large n. • Our methods and results should be useful for various statistical and quantum information theory calculations.

  4. Evidence for an isomer in {sup 76}Ni

    Energy Technology Data Exchange (ETDEWEB)

    Sawicka, M.; Pfuetzner, M. [Institute of Experimental Physics, Warsaw University, PL-00-681, Warszawa (Poland); Grzywacz, R. [Institute of Experimental Physics, Warsaw University, PL-00-681, Warszawa (Poland); Physics Division, ORNL, TN 37831-6371, Oak Ridge (United States); Daugas, J.M.; Belier, G.; Sauvestre, J.E. [CEA Bruyeres-le-Chatel DIF/DPTA/SPN, BP 12, F-91680, Bruyeres-le-Chatel (France); Matea, I.; Lewitowicz, M.; Georgiev, G. [GANIL, BP 5027, F-14021, Caen Cedex (France); Grawe, H.; Mayet, P. [GSI, Planckstrasse 1, D-64291, Darmstadt (Germany); Becker, F. [GANIL, BP 5027, F-14021, Caen Cedex (France); GSI, Planckstrasse 1, D-64291, Darmstadt (Germany); Bingham, C. [Department of Physics and Astronomy, University of Tennessee, TN 37996, Knoxville (United States); Borcea, R.; Hammache, F.; Ibrahim, F. [IPN, 91406, Orsay Cedex (France); Bouchez, E. [CEA Saclay, DSM/DAPNIA/SPhN, F-91191, Gif-sur-Yvette Cedex (France); Buta, A.; Dragulescu, E. [IFIN-HH, P.O. Box MG6, 76900, Bucharest-Magurele (Romania); Giovinazzo, J. [CENBG, BP 120, F-33175, Gradignan Cedex (France); Meot, V.; Negoita, F.; De Oliveira Santos, F.; Perru, O.; Roig, O.; Rykaczewski, K.P.; Saint-Laurent, M.G.; Sorlin, O.; Stanoiu, M.; Stefan, I.; Stodel, C.; Theisen, C.; Verney, D.

    2004-04-01

    In the experiment performed at the LISE2000 spectrometer at GANIL neutron-rich nickel isotopes were studied by microsecond isomer spectroscopy. Evidence for an isomer in {sup 76}Ni is found, consistently with the shell model prediction of an 8{sup +} state of {nu}(g{sub 9/2}){sup 2} structure. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Katja Maria Hydle

    2016-01-01

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

  6. Development of high heat resistant polyphenols applied to the spin-on carbon hardmask

    Science.gov (United States)

    Takigawa, Tomoaki; Horiuchi, Junya; Uchiyama, Naoya; Okada, Kana; Shimizu, Yoko; Makinoshima, Takashi; Sato, Takashi; Echigo, Masatoshi

    2017-03-01

    In this paper, we report on new polyphenols synthesized by the condensation compounds of phenols and aldehydes. The phenols were 4,4'-biphenol, 2,6-dihydroxynaphthalene and 2,7-dihydroxynaphthalene. The aldehydes were 4- phenylbenzaldehyde and 4,4'-biphenyldicarbaldehyde. And we evaluated basic properties for the Spin-On Carbon Hardmask [1]. We recognized 4,4'-biphenol was showed good applicability to the best raw material of the phenols for polyphenol, and 2,6-dihydroxynaphthalene was showed good applicability to better raw material for polyphenol than 2,7-dihydroxynaphthalene. 4,4'-biphenyldicaraldehyde was better raw material of the aldehydes for polyphenols than 4- phenylbenzaldehyde, in solubility. As for heat resistance, 2,6-dihydroxynaphthalene was the best raw material of the phenols for polyphenols, 2,7-dihydroxynaphthalene was better raw material for polyphenols than 4,4'-biphenol. However, NF7177 synthesized by the condensation of 4,4'-biphenol and 4-phenylbenzaldehyde and NF7A78 synthesized by the condensation of 4,4'-biphenol and 4,4'-biphenyldicarbaldehyde seem to be crosslinking by heating, whence the heat resistance of the polyphenols using 4,4'-biphenol might be improved by optimizing heating condition. These materials are low molecular weight of less than 1000, so we expected having good planarization and gap filling.

  7. High resolution magic angle spinning 1H NMR of childhood brain and nervous system tumours

    Directory of Open Access Journals (Sweden)

    Davies Nigel P

    2009-02-01

    Full Text Available Abstract Background Brain and nervous system tumours are the most common solid cancers in children. Molecular characterisation of these tumours is important for providing novel biomarkers of disease and identifying molecular pathways which may provide putative targets for new therapies. 1H magic angle spinning NMR spectroscopy (1H HR-MAS is a powerful tool for determining metabolite profiles from small pieces of intact tissue and could potentially provide important molecular information. Methods Forty tissue samples from 29 children with glial and primitive neuro-ectodermal tumours were analysed using HR-MAS (600 MHz Varian gHX nanoprobe. Tumour spectra were fitted to a library of individual metabolite spectra to provide metabolite values. These values were then used in a two tailed t-test and multi-variate analysis employing a principal component analysis and a linear discriminant analysis. Classification accuracy was estimated using a leave-one-out analysis and B632+ bootstrapping. Results Glial tumours had significantly (two tailed t-test p Conclusion HR-MAS identified key differences in the metabolite profiles of childhood brain and nervous system improving the molecular characterisation of these tumours. Further investigation of the underlying molecular pathways is required to assess their potential as targets for new agents.

  8. Double longitudinal spin asymmetries in single hadron photoproduction at high p_T at COMPASS

    CERN Document Server

    Levillain, Maxime

    This thesis presents a new study aiming at constraining the gluon contribution {\\Delta G} to the 1/2 nucleon spin. The collinear pQCD theoretical framework, on which it is based, deals with asymmetries calculated from cross-sections for single inclusive hadron in the regime of quasi-real photoproduction {Q^2 1 GeV/c). These calculations are done up to Next-to-Leading order with a foreseen inclusion of Next-to-Leading logarithm threshold gluon resummation, only performed for the unpolarised cross-sections yet. This makes the asymmetries sensitive to the gluon polarisation not only through Photon Gluon Fusion {\\gamma* g} but also through resolved {\\gamma*}g processes such as qg or gg. The measurement of the asymmetries is performed for all the COMPASS data available from 2002 to 2011 with a polarised muon beam at 160-200 GeV scattered off a longitudinally polarised target of deuteron ( {_6LiD} for 2002-2006) or proton ({NH_3} for 2007 and 2011). The asymmetries are presented in bins of pT and of pseudorapidity...

  9. High-field magnetic phase transitions and spin excitations in magnetoelectric LiNiPO4

    DEFF Research Database (Denmark)

    Toft-Petersen, Rasmus; Jensen, Jens; Jensen, Thomas Bagger Stibius

    2011-01-01

    The magnetically ordered phases and spin dynamics of magnetoelectric LiNiPO4 have been studied in fields up to 17.3 T along the c axis. Using neutron diffraction, we show that a previously proposed linearly polarized incommensurate (IC) structure exists only for temperatures just below the Neel...... temperature T-N. The ordered IC structure at the lowest temperatures is shown instead to be an elliptically polarized canted spiral for fields larger than 12 T. The transition between the two IC phases is of second order and takes place about 2 K below T-N. For mu H-0 > 16 T and temperatures below 10 K......, the spiral structure is found to lock in to a period of five crystallographic unit cells along the b axis. Based on the neutron-diffraction data, combined with detailed magnetization measurements along all three crystallographic axes, we establish the magnetic phase diagrams for fields up to 17.3 T along c...

  10. High frequency out-of-plane oscillation with large cone angle in mag-flip spin torque oscillators for microwave assisted magnetic recording

    Science.gov (United States)

    Bosu, S.; Sepehri-Amin, H.; Sakuraba, Y.; Kasai, S.; Hayashi, M.; Hono, K.

    2017-04-01

    We investigated spin torque induced magnetization dynamics in the mag-flip spin torque oscillators (STOs) of diameters D from 29 to 96 nm comprising of an in-plane magnetized field generation layer (FGL) Fe67Co33 (7 nm) with high saturation magnetization, μ0Ms ˜ 2.3 T, and perpendicular FePt(10 nm)/Co2FeGa0.5Ge0.5(3 nm) highly spin polarized spin injection layers. Out-of-plane high frequency, f ˜ 21-26 GHz, spin torque induced oscillation with a large cone angle in FGL was observed under nearly perpendicular external magnetic field μ0Hext of 1.1 T for the pillar D of 29 and 42 nm. Our micromagnetic simulation results indicated that ac magnetic fields of about 0.15 to 0.2 T are obtainable from the STOs having the same stacking structure and size as the experiment, which is large enough for the applications to microwave assisted magnetic recording technology.

  11. Lutein and Zeaxanthin Isomers in Eye Health and Disease.

    Science.gov (United States)

    Mares, Julie

    2016-07-17

    Current evidence suggests lutein and its isomers play important roles in ocular development in utero and throughout the life span, in vision performance in young and later adulthood, and in lowering risk for the development of common age-related eye diseases in older age. These xanthophyll (oxygen-containing) carotenoids are found in a wide variety of vegetables and fruits, and they are present in especially high concentrations in leafy green vegetables. Additionally, egg yolks and human milk appear to be bioavailable sources. The prevalence of lutein, zeaxanthin, and meso-zeaxanthin in supplements is increasing. Setting optimal and safe ranges of intake requires additional research, particularly in pregnant and lactating women. Accumulating evidence about variable interindividual response to dietary intake of these carotenoids, based on genetic or metabolic influences, suggests that there may be subgroups that benefit from higher levels of intake and/or alternate strategies to improve lutein and zeaxanthin status.

  12. Solution spinning of high-T{sub c} oxide superconductors: part VII. The effect of polyvinyl alcohol spinning medium on the sintering of YBa{sub 2}Cu{sub 3}O{sub x} superconducting filaments

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Hisayo [Suzuka Junior College, 1250 Shono, Suzuka, Mie 513 (Japan); Goto, Tomoko; Takahashi, Kiyohisa [Department of Material Science and Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466 (Japan)

    1996-05-01

    As basic research for the solution spinning of high-T{sub c} oxide superconductor, the effect of poly(vinyl alcohol) (PVA) spinning medium on the sintering of YBa{sub 2}Cu{sub 3}O{sub x} filament was examined. A precursor filament was produced by dry-spinning starting from a homogeneous aqueous PVA solution of Y, Ba and Cu acetates. The as-drawn filament was pyrolysed to remove volatile components and sintered to generate a superconducting phase. The degree of polymerization (DP) of PVA and the content of acetates in the precursor filament affected the J{sub c} of the sintered filament. Although most filaments exhibited high J{sub c} greater than 10{sup 3} A cm{sup -3} at 77 K and 0 T, superconductivity above 77 K was not observed for the filament spun from PVA solution of DP=2450 with [acetates]/[PVA]=2 and sintered at 900 and 920{sup 0}C for 15 min. The filament had a dense structure due to liquid phase sintering. The filament with high J{sub c} had a skin-core structure, and the highest J{sub c} of 4.3x10{sup 3} A cm{sup -2} at 77 K and 0 T was attained for the filament from DP=3500 with [acetates]/[PVA]=4. (author)

  13. A high-resolution fast spin-echo inversion-recovery sequence for preoperative localization of the internal globus pallidus.

    Science.gov (United States)

    Reich, C A; Hudgins, P A; Sheppard, S K; Starr, P A; Bakay, R A

    2000-05-01

    A fast spin-echo inversion-recovery (FSE-IR) sequence is described for its utility regarding surgical planning for patients with Parkinson's disease (PD) who are undergoing microelectrode-guided internal globus pallidus (GPi) ablation. Images from thirty-seven adult patients with PD were reviewed and visualization of the GPi, globus pallidus externa (GPe), and the intervening lamina was noted. High-resolution images were acquired from all patients despite the external hardware and the patients' movement disorder. In all cases, the conventional surgical trajectory, determined indirectly by a fixed measurement from the anteroposterior commissure line, was modified by the ability to visualize the GPi and optic tract directly. This sequence facilitated accurate stereotactic targeting.

  14. High-spin states and a new band based on the isomeric state in {sup 152}Nd

    Energy Technology Data Exchange (ETDEWEB)

    Yeoh, E.Y.; Wang, J.G.; Ding, H.B.; Gu, L.; Xu, Q.; Xiao, Z.G. [Tsinghua University, Department of Physics, Beijing (China); Zhu, S.J. [Tsinghua University, Department of Physics, Beijing (China); Vanderbilt University, Department of Physics, Nashville, TN (United States); Hamilton, J.H.; Ramayya, A.V.; Hwang, J.K.; Liu, S.H.; Li, K. [Vanderbilt University, Department of Physics, Nashville, TN (United States); Yang, Y.C.; Sun, Y. [Shanghai Jiao Tong University, Department of Physcis, Shanghai (China); Luo, Y.X. [Vanderbilt University, Department of Physics, Nashville, TN (United States); Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Rasmussen, J.O.; Lee, I.Y. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Ma, W.C. [Mississippi State University, Department of Physics, Mississippi State, MS (United States)

    2010-08-15

    High-spin states of the neutron-rich {sup 152}Nd nucleus have been reinvestigated by measuring the prompt {gamma} -rays in the spontaneous fission of {sup 252}Cf. The ground-state band and a side negative-parity band have been updated. A new band based on the 2243.7keV isomeric state has been identified. The half-life for the isomeric state has been measured to be 63(7)ns. The projected shell model is employed to study the band structure of this nucleus. The results show that the calculated levels of the bands are in good agreement with the experimental ones, and the isomeric state and the negative-parity band are based on the proton {pi} 5/2{sup -}[532] x {pi}9/2{sup +}[404] and neutron {nu} 3/2{sup -}[521] x {nu}5/2{sup +}[642] two-quasiparticles configurations, respectively. (orig.)

  15. High-Resolution Two-Dimensional Optical Spectroscopy of Electron Spins

    Directory of Open Access Journals (Sweden)

    M. Salewski

    2017-08-01

    Full Text Available Multidimensional coherent optical spectroscopy is one of the most powerful tools for investigating complex quantum mechanical systems. While it was conceived decades ago in magnetic resonance spectroscopy using microwaves and radio waves, it has recently been extended into the visible and UV spectral range. However, resolving MHz energy splittings with ultrashort laser pulses still remains a challenge. Here, we analyze two-dimensional Fourier spectra for resonant optical excitation of resident electrons to localized trions or donor-bound excitons in semiconductor nanostructures subject to a transverse magnetic field. Particular attention is devoted to Raman coherence spectra, which allow one to accurately evaluate tiny splittings of the electron ground state and to determine the relaxation times in the electron spin ensemble. A stimulated steplike Raman process induced by a sequence of two laser pulses creates a coherent superposition of the ground-state doublet which can be retrieved only optically because of selective excitation of the same subensemble with a third pulse. This provides the unique opportunity to distinguish between different complexes that are closely spaced in energy in an ensemble. The related experimental demonstration is based on photon-echo measurements in an n-type CdTe/(Cd,MgTe quantum-well structure detected by a heterodyne technique. The difference in the sub-μeV range between the Zeeman splittings of donor-bound electrons and electrons localized at potential fluctuations can be resolved even though the homogeneous linewidth of the optical transitions is larger by 2 orders of magnitude.

  16. Mn7 species with an S = 29/2 ground state: high-frequency EPR studies of a species at the classical/quantum spin interface.

    Science.gov (United States)

    Wang, Zhenxing; van Tol, Johan; Taguchi, Taketo; Daniels, Matthew R; Christou, George; Dalal, Naresh S

    2011-11-09

    A high spin (S) compound has been synthesized whose properties straddle the interface between the classical and quantum mechanical spin descriptions. The cluster [Mn(7)O(4)(pdpm)(6)(N(3))(4)](ClO(4))(2) (Mn(7)) has an unprecedented core structure comprising an octahedral [Mn(III)(6)(μ(4)-O)(μ(3)-O)(3)(μ(3)-N(3))(4)](6+) unit with one of its faces capped by a Mn(II) ion. Magnetization and susceptibility studies indicate an S = (29/2) ground state, the maximum possible. Variable-temperature, high-frequency electron paramagnetic resonance (HF-EPR) spectra on powder and single-crystal samples of Mn(7) exhibit sharp spectral features characteristic of a quantum spin that are well resolved in a certain temperature range but which transform to a continuum of peaks characteristic of a classical spin in another; these features have been well reproduced by computer simulations. A fast Fourier transform analysis of the sharp spectral features and the low temperature EPR spectra suggests that more than one spin state are involved.

  17. Spin Electronics

    Science.gov (United States)

    2003-08-01

    spin resonance of rare earth and transition metal impurities in chalcopyrite semiconductors. They also have worked in diluted magnetic...past, the ferromagnetic injector had been a ferromagnetic metal or alloy containing 3d transition elements with fractional spin polarization of the...polarized carriers. There have been numerous attempts to inject transition metals or their alloys into semiconductors, either directly (Johnson and

  18. Exotic spin phases in the one-dimensional spin-1/2 quantum magnet LiCuSbO{sub 4} as seen by high-field NMR and ESR spectroscopies

    Energy Technology Data Exchange (ETDEWEB)

    Iakovleva, Margarita [IFW Dresden, Dresden (Germany); TU Dresden, Dresden (Germany); Zavoisky Physical Technical Institute, Kazan (Russian Federation); Grafe, Hans-Joachim; Kataev, Vladislav; Alfonsov, Alexey; Sturza, Mihai I.; Wurmehl, Sabine [IFW Dresden, Dresden (Germany); Vavilova, Evgeniia [Zavoisky Physical Technical Institute, Kazan (Russian Federation); Nojiri, Hiroyuki [Institute of Materials Research, Sendai (Japan); Buechner, Bernd [IFW Dresden, Dresden (Germany); TU Dresden, Dresden (Germany)

    2016-07-01

    We will present our recent results of high-field NMR and sub-THz ESR studies of the quantum magnet LiCuSbO{sub 4} (LCSO) that presents an excellent model system of a one-dimensional spin-1/2 quantum magnet with frustrated exchange interactions. Such networks are predicted to exhibit a plethora of novel ground states beyond classical ferro- or antiferromagnetic phases. In LCSO the absence of a long-range magnetic order down to sub-Kelvin temperatures is suggestive of the realization of a quantum spin liquid state. Our NMR and ESR measurements in strong magnetic fields up to 16 Tesla reveal clear indications for the occurrence of an exotic field-induced hidden phase which we will discuss in terms of multipolar physics.

  19. Spin glasses

    CERN Document Server

    Bovier, Anton

    2007-01-01

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

  20. Occurrence and distribution of hexachlorocyclohexane isomers in vegetation samples from a contaminated area.

    Science.gov (United States)

    Abhilash, P C; Jamil, Sarah; Singh, Vandana; Singh, Amita; Singh, Nandita; Srivastava, S C

    2008-05-01

    The occurrence and distribution of four major hexachlorocyclohexane (HCH) isomers (alpha-, beta-, gamma- and delta-) were studied in vegetation samples of a highly contaminated area close to a small-scale industrial belt in Lucknow (North India). Eight species of plants were collected at different points of the contaminated area and different parts of the plants were separated in order to study the difference in uptake and accumulation. The samples were extracted by matrix solid-phase dispersion (MSPD) extraction and finally determined by a gas-chromatograph equipped with (63)Ni electron capture detector (ECD). HCH isomers were present in almost all samples and the concentration of total HCH in the plant sample analyzed varied between 13 and 44 mg kg(-1), being the main isomer of beta-HCH (8-22 mg kg(-1)). Lindane (gamma-HCH) was present in all samples (1-9 mg kg(-1)). Solanum torvum Sw., and Erianthus munja shows the highest and lowest capacity for accumulation of HCH, respectively with a significant difference at pSolanum torvum Sw., and Withania somnifera (L.) Dunal could accumulate considerable levels of HCH isomers (44 and 34 mg kg(-1), respectively). The results reflect the importance of plants in monitoring purposes and their potential for phytoremediation of HCH contaminated soils.

  1. Prospects for measuring the $^{229}$Th isomer energy using a metallic magnetic microcalorimeter

    CERN Document Server

    Kazakov, G A; Sterba, J H; Fleischmann, A; Enss, C; Schumm, T

    2013-01-01

    The Thorium-229 isotope features a nuclear isomer state with extremely low energy. The currently most accepted energy value, $7.8 \\pm 0.5$\\,eV, was obtained from an indirect measurements using a NASA x-ray microcalorimeter with instrumental resolution (FWHM) of 26\\,eV. We study, how state-of-the-art magnetic metallic microcalorimeters with an energy resolution down to a few eV can be used to measure the isomer energy. Resolving the 29.18\\,keV doublet in the $\\gamma$-spectrum following the $\\alpha$-decay of Uranium-233, corresponding to the decay into the ground and isomer state, allows to measure the isomer transition energy without additional theoretical input parameters and increase the energy accuracy. We study the dependence of the attainable precision of this measurement on the signal and background count rates and the instrumental energy resolution. Assuming realistic experimental parameters corresponding to the currently available detector technology, we show that such a measurement is highly feasable.

  2. Spin-inversion in nanoscale graphene sheets with a Rashba spin-orbit barrier

    Directory of Open Access Journals (Sweden)

    Somaieh Ahmadi

    2012-03-01

    Full Text Available Spin-inversion properties of an electron in nanoscale graphene sheets with a Rashba spin-orbit barrier is studied using transfer matrix method. It is found that for proper values of Rashba spin-orbit strength, perfect spin-inversion can occur in a wide range of electron incident angle near the normal incident. In this case, the graphene sheet with Rashba spin-orbit barrier can be considered as an electron spin-inverter. The efficiency of spin-inverter can increase up to a very high value by increasing the length of Rashba spin-orbit barrier. The effect of intrinsic spin-orbit interaction on electron spin inversion is then studied. It is shown that the efficiency of spin-inverter decreases slightly in the presence of intrinsic spin-orbit interaction. The present study can be used to design graphene-based spintronic devices.

  3. Evidence for Fast Electron Transfer between the High-Spin Haems in Cytochrome bd-I from Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Sergey A Siletsky

    Full Text Available Cytochrome bd-I is one of the three proton motive force-generating quinol oxidases in the O2-dependent respiratory chain of Escherichia coli. It contains one low-spin haem (b558 and the two high-spin haems (b595 and d as the redox-active cofactors. In order to examine the flash-induced intraprotein reverse electron transfer (the so-called ''electron backflow'', CO was photolyzed from the ferrous haem d in one-electron reduced (b5583+b5953+d2+-CO cytochrome bd-I, and the fully reduced (b5582+b5952+d2+-CO oxidase as a control. In contrast to the fully reduced cytochrome bd-I, the transient spectrum of one-electron reduced oxidase at a delay time of 1.5 μs is clearly different from that at a delay time of 200 ns. The difference between the two spectra can be modeled as the electron transfer from haem d to haem b595 in 3-4% of the cytochrome bd-I population. Thus, the interhaem electron backflow reaction induced by photodissociation of CO from haem d in one-electron reduced cytochrome bd-I comprises two kinetically different phases: the previously unnoticed fast electron transfer from haem d to haem b595 within 0.2-1.5 μs and the slower well-defined electron equilibration with τ ~16 μs. The major new finding of this work is the lack of electron transfer at 200 ns.

  4. Nuclear inelastic scattering of 1D polymeric Fe(II) complexes of 1,2,4-aminotriazole in their high-spin and low-spin state

    Energy Technology Data Exchange (ETDEWEB)

    Wolny, Juliusz A., E-mail: wolny@physik.uni-kl.de; Rackwitz, Sergej [University of Kaiserslautern, Department of Physics (Germany); Achterhold, Klaus [Technische Universitaet Muenchen, Department of Physics (Germany); Muffler, Kai; Schuenemann, Volker [University of Kaiserslautern, Department of Physics (Germany)

    2012-03-15

    The vibrational properties of Fe(II) 1D spin crossover polymers have been characterized by nuclear inelastic scattering (NIS). The complexes under study were the tosylate and perchlorate salts of ([Fe(4-amino-1,2,4-triazole){sub 3}] <{sup +2}){sub n} complexes. The complexes have LS (S = 0) marker bands in the range of 300-500 cm{sup - 1}, while the marker bands corresponding to the HS (S = 2) state are detected between 200 cm{sup - 1} and 300 cm{sup - 1}, in line with the decreasing Fe-N bond strengths during the transition from LS to HS. Accompanying DFT calculations using the functional B3LYP and the basis set CEP-31G confirm these assignments.

  5. Ultra-high mobility transparent organic thin film transistors grown by an off-centre spin-coating method

    Science.gov (United States)

    Yuan, Yongbo; Giri, Gaurav; Ayzner, Alexander L.; Zoombelt, Arjan P.; Mannsfeld, Stefan C. B.; Chen, Jihua; Nordlund, Dennis; Toney, Michael F.; Huang, Jinsong; Bao, Zhenan

    2014-01-01

    Organic semiconductors with higher carrier mobility and better transparency have been actively pursued for numerous applications, such as flat-panel display backplane and sensor arrays. The carrier mobility is an important figure of merit and is sensitively influenced by the crystallinity and the molecular arrangement in a crystal lattice. Here we describe the growth of a highly aligned meta-stable structure of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) from a blended solution of C8-BTBT and polystyrene by using a novel off-centre spin-coating method. Combined with a vertical phase separation of the blend, the highly aligned, meta-stable C8-BTBT films provide a significantly increased thin film transistor hole mobility up to 43 cm2 Vs-1 (25 cm2 Vs-1 on average), which is the highest value reported to date for all organic molecules. The resulting transistors show high transparency of >90% over the visible spectrum, indicating their potential for transparent, high-performance organic electronics.

  6. Assignment of the stereochemistry of the isomers of IQNP

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, D.W.; Knapp, F.F. Jr. [Oak Ridge National Lab., TN (United States)

    1996-05-01

    The isomers of 1-azabicyclo[2.2.2]oct-3-yl {alpha}-hydroxy-{alpha}-(1-iodo-1-propen-3-yl)-{alpha}-phenylacetate (IQNP) are attractive for in vivo imaging of muscarinic receptors (mAChR). Although the stereocenter of the quinuclidinyl ring has been studied, the isomers of IQNP are oils and the configuration of the acetate center has not been elucidated. An improved synthesis of the acetate moiety (3) via a chiral intermediate has been developed and allows assignment of the configuration of the acetate. 1,3-dioxolan-4-one (1), (condensation of R- or S-mandelic acid and pivaldehyde) was alkylated with propargyl bromide, treated with base and esterified to afford R-(-)- or S-(+)-3. R- and S-3 were prepared in a 94:6 and 98:2 enantiomeric excess, respectively (HPLC analysis). R- and S-3 were utilized to synthesize the various isomers of IQNP. By comparing the optical rotation, HPLC and NMR of these isomers to those prepared by classical resolution allows the assignment of E-R, R-IQNP as the isomer demonstrating binding to M{sub 1} mAChR subtype and Z-R, R-IQNP as the isomer binding to M{sub 1} and M{sub 2}mAChR subtypes. This route also permits a simplified route for the preparation of the isomers of IQNP.

  7. Adsorption and Diffusion of Xylene Isomers on Mesoporous Beta Zeolite

    Directory of Open Access Journals (Sweden)

    Aixia Song

    2015-12-01

    Full Text Available A systematic and detailed analysis of adsorption and diffusion properties of xylene isomers over Beta zeolites with different mesoporosity was conducted. Adsorption isotherms of xylene isomers over microporous and mesoporous Beta zeolites through gravimetric methods were applied to investigate the impact of mesopores inside Beta zeolites on the adsorption properties of xylene isomers in the pressure range of lower 20 mbar. It is seen that the adsorption isotherms of three xylene isomers over microporous and mesoporous Beta zeolites could be successfully described by the single-site Toth model and the dual-site Toth model, respectively. The enhanced adsorption capacities and decreased Henry’s constants (KH and the initial heats of adsorption (Qst for the all xylene isomers are observed after the introduction of mesopores in the zeolites. For three xylene isomers, the order of Henry’s constant is o-xylene > m-xylene > p-xylene, whereas the adsorption capacities of Beta zeolite samples for xylene isomers execute the following order of o-xylene > p-xylene > m-xylene, due to the comprehensive effects from the molecular configuration and electrostatic interaction. At the same time, the diffusion properties of xylene isomers in the mesoporous Beta zeolites were also studied through the desorption curves measured by the zero length column (ZLC method at 333–373 K. It turned out that the effective diffusion time constant (Deff/R2 is a growing trend with the increasing mesoporosity, whereas the tendency of the activation energy is just the reverse, indicating the contribution of mesopores to facilitate molecule diffusion by shortening diffusion paths and reducing diffusion resistances. Moreover, the diffusivities of three xylene isomers in all Beta zeolites follow an order of p-xylene > m-xylene > o-xylene as opposed to KH, conforming the significant effects of adsorbate-adsorbent interaction on the diffusion.

  8. High-spin states and lifetimes in 33S and shell-model interpretation in the s d -f p space

    Science.gov (United States)

    Aydin, S.; Ionescu-Bujor, M.; Gavrilov, G. Tz.; Dimitrov, B. I.; Lenzi, S. M.; Recchia, F.; Tonev, D.; Bouhelal, M.; Kavillioglu, F.; Pavlov, P.; Bazzacco, D.; Bizzeti, P. G.; Bizzeti-Sona, A. M.; de Angelis, G.; Deloncle, I.; Farnea, E.; Gadea, A.; Gottardo, A.; Goutev, N.; Haas, F.; Huyuk, T.; Laftchiev, H.; Lunardi, S.; Marinov, Tz. K.; Mengoni, D.; Menegazzo, R.; Michelagnoli, C.; Napoli, D. R.; Petkov, P.; Sahin, E.; Singh, P. P.; Stefanova, E. A.; Ur, C. A.; Valiente-Dobón, J. J.; Yavahchova, M. S.

    2017-08-01

    The structure of the 33S nucleus was investigated in the 24Mg(14N,α p ) fusion-evaporation reaction using a 40-MeV 14N beam. The level scheme was extended up to an excitation energy of 11.7 MeV and spin 19 /2+ . Lifetimes of the intermediate- and high-spin states have been investigated by the Doppler shift attenuation method. Data were compared with different shell-model calculations where effective interactions involving two main shells, the sd and the fp, are used.

  9. Model for the high-temperature oxygen-ordering thermodynamics in YBa2Cu3O6+x - inclusion of electron spin and charge degrees of freedom

    DEFF Research Database (Denmark)

    Schleger, P.; Hardy, W.N.; Casalta, H.

    1994-01-01

    A lattice-gas model for the high temperature oxygen-ordering thermodynamics in YBa2Cu3O6+x is presented, which assumes constant effective pair interactions between oxygen atoms and includes in a simple fashion the effect of the electron spin and charge degrees of freedom. This is done using...... a commonly utilized picture relating the creation of mobile electron holes and unpaired spins to the insertion of oxygen into the basal plane. The model is solved using the nearest-neighbor square approximation of the cluster-variation method. In addition, preliminary Monte Carlo results using next...

  10. A study of spin-lattice relaxation rates of glucose, fructose, sucrose and cherries using high-T c SQUID-based NMR in ultralow magnetic fields

    Science.gov (United States)

    Liao, Shu-Hsien; Wu, Pei-Che

    2017-08-01

    We study the concentration dependence of spin-lattice relaxation rates, T 1 -1, of glucose, fructose, sucrose and cherries by using high-T c SQUID-based NMR at magnetic fields of ˜97 μT. The detected NMR signal, Sy (T Bp), is fitted to [1 - exp(-T Bp/T 1)] to derive T 1 -1, where Sy (T Bp) is the strength of the NMR signal, T Bp is the duration of pre-polarization and T 1 -1 is the spin-lattice relaxation rate. It was found that T 1 -1 increases as the sugar concentrations increase. The increased T 1 -1 is due to the presence of more molecules in the surroundings, which increases the spin-lattice interaction and in turn enhances T 1 -1. The T 1 -1 versus degrees Brix curve provides a basis for determining unknown Brix values for cherries as well as other fruits.

  11. High-spin configuration of Mn in Bi{sub 2}Se{sub 3} three-dimensional topological insulator

    Energy Technology Data Exchange (ETDEWEB)

    Wolos, Agnieszka, E-mail: agnieszka.wolos@fuw.edu.pl [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw (Poland); Drabinska, Aneta [Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw (Poland); Borysiuk, Jolanta [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw (Poland); Sobczak, Kamil [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Kaminska, Maria [Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw (Poland); Hruban, Andrzej [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Institute of Electronic Materials Technology, ul. Wolczynska 133, 01-919 Warsaw (Poland); Strzelecka, Stanislawa G.; Materna, Andrzej; Piersa, Miroslaw; Romaniec, Magdalena; Diduszko, Ryszard [Institute of Electronic Materials Technology, ul. Wolczynska 133, 01-919 Warsaw (Poland)

    2016-12-01

    Electron paramagnetic resonance was used to investigate Mn impurity in Bi{sub 2}Se{sub 3} topological insulator grown by the vertical Bridgman method. Mn in high-spin S=5/2, Mn{sup 2+}, configuration was detected regardless of the conductivity type of the host material. This means that Mn{sup 2+}(d{sup 5}) energy level is located within the valence band, and Mn{sup 1+}(d{sup 6}) energy level is outside the energy gap of Bi{sub 2}Se{sub 3}. The electron paramagnetic resonance spectrum of Mn{sup 2+} in Bi{sub 2}Se{sub 3} is characterized by the isotropic g-factor |g|=1.91 and large axial parameter D=−4.20 GHz h. This corresponds to the zero-field splitting of the Kramers doublets equal to 8.4 GHz h and 16.8 GHz h, respectively, which is comparable to the Zeeman splitting for the X-band. Mn in Bi{sub 2}Se{sub 3} acts as an acceptor, effectively reducing native-high electron concentration, compensating selenium vacancies, and resulting in p-type conductivity. However, Mn-doping simultaneously favors formation of native donor defects, most probably selenium vacancies. For high Mn-doping it may lead to the resultant n-type conductivity related with strong non-stoichiometry and degradation of the crystal structure - switching from Bi{sub 2}Se{sub 3} to BiSe phase. - Highlights: • We studied electron paramagnetic resonance in Bi{sub 2}Se{sub 3}:Mn. • We found Mn in high-spin Mn{sup 2+} configuration in both n-type and p-type samples. • The g-factor for Mn{sup 2+} equals to 1.91 and axial parameter D=−4.20 GHz h. • Mn acts as an acceptor. • Mn substitution affects formation of native donors.

  12. Detection of Actinides via Nuclear Isomer De-Excitation

    Energy Technology Data Exchange (ETDEWEB)

    Francy, Christopher J. [Oregon State Univ., Corvallis, OR (United States)

    2009-07-01

    This dissertation discusses a data collection experiment within the Actinide Isomer Identification project (AID). The AID project is the investigation of an active interrogation technique that utilizes nuclear isomer production, with the goal of assisting in the interdiction of illicit nuclear materials. In an attempt to find and characterize isomers belonging to 235U and its fission fragments, a 232Th target was bombarded with a monoenergetic 6Li ion beam, operating at 45 MeV.

  13. Heme isomers substantially affect heme's electronic structure and function

    DEFF Research Database (Denmark)

    Kepp, Kasper Planeta

    2017-01-01

    to similar energy of the isomers but with a sizable (25 kJ mol-1) barrier to interconversion arising from restricted rotation around the conjugated bonds. The four isomers, EE, EZ, ZE, and ZZ, were then investigated as 4-coordinate hemes, as 5-coordinate deoxyhemes, in 6-coordinate O2-adducts of globins.......e. the effects are not method-dependent. Thus, the nature of the isomer state is an important but overlooked feature of heme chemistry and function, and previous and future studies of hemes may be reconsidered in this new context....

  14. Phenomena of spin rotation and oscillation of particles (atoms, molecules) containing in a trap blowing on by wind of high energy particles in storage ring

    OpenAIRE

    Baryshevsky, Vladimir

    2013-01-01

    Spin rotation and oscillation phenomena of particles captured in a gas target through which beam of high energy particles passes is discussed. Such experiment arrangement make it realizable for storage ring and allows to study zero-angle scattering amplitude at highest possible energies.

  15. Exploring helical folding of oligoureas during chain elongation by high-resolution magic-angle-spinning (HRMAS) NMR spectroscopy.

    Science.gov (United States)

    Violette, Aude; Lancelot, Nathalie; Poschalko, Alexander; Piotto, Martial; Briand, Jean-Paul; Raya, Jesus; Elbayed, Karim; Bianco, Alberto; Guichard, Gilles

    2008-01-01

    The development of novel folding oligomers (foldamers) for biological and biomedical applications requires both precise structural information and appropriate methods to detect folding propensity. However, the synthesis and the systematic conformational investigation of large arrays of oligomers to determine the influence of factors, such as chain length, side chains, and surrounding environment, on secondary structure can be quite tedious. Herein, we show for 2.5-helical N,N'-linked oligoureas (gamma-peptide lineage) that the whole process of foldamer characterization can be accelerated by using high-resolution magic-angle-spinning (HRMAS) NMR spectroscopy. This was achieved by monitoring a simple descriptor of conformational homogeneity (e.g., chemical shift difference between diastereotopic main chain CH2 protons) at different stages of oligourea chain growth on a solid support. HRMAS NMR experiments were conducted on two sets of oligoureas, ranging from dimer to hexamer, immobilized on DEUSS, a perdeuterated poly(oxyethylene)-based solid support swollen in solvents of low to high polarity. One evident advantage of the method is that only minute amount of material is required. In addition, the resonance of the deuterated resin is almost negligeable. On-bead NOESY spectra of high quality and with resolution comparable to that of liquid samples were obtained for longer oligomers, thus allowing detailed structural characterization.

  16. Spin Physics at COMPASS

    CERN Document Server

    Schill, C

    2012-01-01

    The COMPASS experiment is a fixed target experiment at the CERN SPS using muon and hadron beams for the investigation of the spin structure of the nucleon and hadron spectroscopy. The main objective of the muon physics program is the study of the spin of the nucleon in terms of its constituents, quarks and gluons. COMPASS has accumulated data during 6 years scattering polarized muons off a longitudinally or a transversely polarized deuteron (6LiD) or proton (NH3) target. Results for the gluon polarization are obtained from longitudinal double spin cross section asymmetries using two different channels, open charm production and high transverse momentum hadron pairs, both proceeding through the photon-gluon fusion process. Also, the longitudinal spin structure functions of the proton and the deuteron were measured in parallel as well as the helicity distributions for the three lightest quark flavors. With a transversely polarized target, results were obtained with proton and deuteron targets for the Collins an...

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

    Directory of Open Access Journals (Sweden)

    Saburo Takahashi and Sadamichi Maekawa

    2008-01-01

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

  18. Spin electronics

    CERN Document Server

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

    2004-01-01

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

  19. High-performance spinning device for DVD-based micromechanical signal transduction

    DEFF Research Database (Denmark)

    Hwu, En-Te; Chen, Ching-Hsiu; Bosco, Filippo

    2013-01-01

    mechanism, this device can simultaneously measure surface topography, mechanical deflections and resonance frequencies of several microfabricated beams at a high speed. In biochemical sensing applications, the OPU can measure bending changes of functionalized microcantilevers, providing a statistically...

  20. High-intensity polarized H- ion source for the RHIC SPIN physics

    Science.gov (United States)

    Zelenski, A.; Atoian, G.; Raparia, D.; Ritter, J.; Kolmogorov, A.; Davydenko, V.

    2017-08-01

    A novel polarization technique had been successfully implemented for the RHIC polarized H- ion source upgrade to higher intensity and polarization. In this technique a proton beam inside the high magnetic field solenoid is produced by ionization of the atomic hydrogen beam (from external source) in the He-gas ionizer cell. Further proton polarization is produced in the process of polarized electron capture from the optically-pumped Rb vapour. The use of high-brightness primary beam and large cross-sections of charge-exchange cross-sections resulted in production of high intensity H- ion beam of 85% polarization. High beam brightness and polarization resulted in 75% polarization at 23 GeV out of AGS and 60-65% beam polarization at 100-250 GeV colliding beams in RHIC. The status of un-polarized magnetron type (Cs-vapour loaded) BNL source is also discussed.

  1. Metabolomics approach to thyroid nodules: a high-resolution magic-angle spinning nuclear magnetic resonance-based study.

    Science.gov (United States)

    Miccoli, Paolo; Torregrossa, Liborio; Shintu, Laetitia; Magalhaes, Alviclér; Chandran, JimaNambiath; Tintaru, Aura; Ugolini, Clara; Minuto, Michele N; Miccoli, Mario; Basolo, Fulvio; Caldarelli, Stefano

    2012-12-01

    Proton magnetic resonance spectroscopy of operative specimens has been reported to successfully differentiate normal tissue from malignant thyroid tissue. We used a new high-resolution magnetic resonance spectroscopy technique for the differentiation of benign and malignant thyroid neoplasms. Histological specimens from 72 patients undergoing a total thyroidectomy were processed into a 4-mm ZrO(2) high-resolution magic angle spinning (HRMAS) rotor with 5 μL of D(2)O. A Bruker Avance spectrometer operating at 400 MHz for the (1)H frequency and equipped with a (1)H/(13)C/(31)P HRMAS probe was used. Normal and neoplastic thyroid tissues could be discriminated from each other by different relative concentrations of several amino acids and lipids, as well as benign and malignant neoplasms, that differed in terms of a greater lactate and taurine and a lesser lipid choline, phosphocholine, myo-inositol, and scyllo-inositol levels in malignant samples. A statistical analysis with a receiver operating characteristic curve revealed that 77% of the samples were accurately predicted. Similar results were obtained with specimens obtained from ex vivo aspirates. A further development of this project will be to use the metabolomics approach on specimens obtained from aspirates in vivo after the resolution of technical problems attributable to possible contamination. Copyright © 2012 Mosby, Inc. All rights reserved.

  2. Functionalized Solvents for Olefin Isomer Purification by Reactive Extractive Distillation

    NARCIS (Netherlands)

    Kuipers, N.J.M.; Wentink, A.E.; de Haan, A.B.; Scholtz, J.; Mulder, H.

    2007-01-01

    Olefin isomer separations are difficult, energy intensive and thus expensive. An overview is presented to investigate the feasibility of metal–ligand complexes as functionalized solvents applied in a novel separation technology, reactive extractive distillation, for the separation and purification

  3. N-Protonated Isomers as Gateways to Peptide Ion Fragmentation

    National Research Council Canada - National Science Library

    Haeffner, Fredrik; Merle, John K; Irikura, Karl K

    2011-01-01

    .... If the intrinsic barrier to dissociation is the same for all backbone sites, the fragmentation propensity at each amide bond should reflect the stability of the corresponding N-protonated isomer...

  4. Carotenoids and Their Isomers: Color Pigments in Fruits and Vegetables

    Directory of Open Access Journals (Sweden)

    Yueming Jiang

    2011-02-01

    Full Text Available Fruits and vegetables are colorful pigment-containing food sources. Owing to their nutritional benefits and phytochemicals, they are considered as ‘functional food ingredients’. Carotenoids are some of the most vital colored phytochemicals, occurring as all-trans and cis-isomers, and accounting for the brilliant colors of a variety of fruits and vegetables. Carotenoids extensively studied in this regard include β-carotene, lycopene, lutein and zeaxanthin. Coloration of fruits and vegetables depends on their growth maturity, concentration of carotenoid isomers, and food processing methods. This article focuses more on several carotenoids and their isomers present in different fruits and vegetables along with their concentrations. Carotenoids and their geometric isomers also play an important role in protecting cells from oxidation and cellular damages.

  5. Simultaneous Determination of Two Isomers of Asarone in Piper ...

    African Journals Online (AJOL)

    Simultaneous Determination of Two Isomers of Asarone in Piper sarmentosum Roxburgh (Piperaceae) Extracts using Different Chromatographic Columns. Mohd Shahrul Ridzuan Hamil, Abdul Hakeem Memon, Amin Malik Shah Abdul Majid, Zhari Ismail ...

  6. Reelfoot/Lake Isom National Wildlife Refuge: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Reelfoot and Lake Isom NWRs for the next 15 years. This plan outlines the refuges'...

  7. Reelfoot and Lake Isom National Wildlife Refuges : Wildlife Inventory Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This wildlife inventory plan for Reelfoot and Lake Isom National Wildlife Refuges includes survey procedure forms that represent cost effective inventory of the...

  8. Spin Funneling for Enhanced Spin Injection into Ferromagnets

    Science.gov (United States)

    Sayed, Shehrin; Diep, Vinh Q.; Camsari, Kerem Yunus; Datta, Supriyo

    2016-07-01

    It is well-established that high spin-orbit coupling (SOC) materials convert a charge current density into a spin current density which can be used to switch a magnet efficiently and there is increasing interest in identifying materials with large spin Hall angle for lower switching current. Using experimentally benchmarked models, we show that composite structures can be designed using existing spin Hall materials such that the effective spin Hall angle is larger by an order of magnitude. The basic idea is to funnel spins from a large area of spin Hall material into a small area of ferromagnet using a normal metal with large spin diffusion length and low resistivity like Cu or Al. We show that this approach is increasingly effective as magnets get smaller. We avoid unwanted charge current shunting by the low resistive NM layer utilizing the newly discovered phenomenon of pure spin conduction in ferromagnetic insulators via magnon diffusion. We provide a spin circuit model for magnon diffusion in FMI that is benchmarked against recent experiments and theory.

  9. Isomer beam elastic scattering: 26mAl(p, p) for astrophysics

    Science.gov (United States)

    Kahl, D.; Shimizu, H.; Yamaguchi, H.; Abe, K.; Beliuskina, O.; Cha, S. M.; Chae, K. Y.; Chen, A. A.; Ge, Z.; Hayakawa, S.; Imai, N.; Iwasa, N.; Kim, A.; Kim, D. H.; Kim, M. J.; Kubono, S.; Kwag, M. S.; Liang, J.; Moon, J. Y.; Nishimura, S.; Oka, S.; Park, S. Y.; Psaltis, A.; Teranishi, T.; Ueno, Y.; Yang, L.

    2018-01-01

    The advent of radioactive ground-state beams some three decades ago ultimately sparked a revolution in our understanding of nuclear physics. However, studies with radioactive isomer beams are sparse and have often required sophisticated apparatuses coupled with the technologies of ground-state beams due to typical mass differences on the order of hundreds of keV and vastly different lifetimes for isomers. We present an application of a isomeric beam of 26mAl to one of the most famous observables in nuclear astrophysics: galactic 26Al. The characteristic decay of 26Al in the Galaxy was the first such specific radioactivity to be observed originating from outside the Earth some four decades ago. We present a newly-developed, novel technique to probe the structure of low-spin states in 27Si. Using the Center for Nuclear Study low-energy radioisotope beam separator (CRIB), we report on the measurement of 26mAl proton resonant elastic scattering conducted with a thick target in inverse kinematics. The preliminary results of this on-going study are presented.

  10. Emergence of a 2d macro-spin liquid in a highly frustrated 3d quantum magnet

    Science.gov (United States)

    Sikkenk, Tycho; Coester, Kris; Buhrandt, Stefan; Fritz, Lars; Schmidt, Kai

    The classical Ising model on the frustrated 3d swedenborgite lattice has disordered spin liquid ground states for all ratios of inter- and intra-planar couplings. Quantum fluctuations due to a transverse field give rise to several exotic phenomena. In the limit of weakly coupled kagome layers we find a 3d version of disorder by disorder degeneracy lifting. For large out-of-plane couplings 1d macro-spins are formed, which realize a disordered macro-spin liquid phase on an emerging 2d triangular lattice. We speculate about a possibly exotic version of quantum criticality that connects the polarized phase to the macro-spin liquid. DFG FR 2627/3-1, D-ITP consortium.

  11. Slow Magic Angle Sample Spinning: A Non- or Minimally Invasive Method for High- Resolution 1H Nuclear Magnetic Resonance (NMR) Metabolic Profiling

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jian Z.

    2011-05-01

    High resolution 1H magic angle spinning nuclear magnetic resonance (NMR), using a sample spinning rate of several kHz or more (i.e., high resolution-magic angle spinning (hr-MAS)), is a well established method for metabolic profiling in intact tissues without the need for sample extraction. The only shortcoming with hr-MAS is that it is invasive and is thus unusable for non-destructive detections. Recently, a method called slow-MAS, using the concept of two dimensional NMR spectroscopy, has emerged as an alternative method for non- or minimal invasive metabolomics in intact tissues, including live animals, due to the slow or ultra-slow-sample spinning used. Although slow-MAS is a powerful method, its applications are hindered by experimental challenges. Correctly designing the experiment and choosing the appropriate slow-MAS method both require a fundamental understanding of the operation principles, in particular the details of line narrowing due to the presence of molecular diffusion. However, these fundamental principles have not yet been fully disclosed in previous publications. The goal of this chapter is to provide an in depth evaluation of the principles associated with slow-MAS techniques by emphasizing the challenges associated with a phantom sample consisting of glass beads and H2O, where an unusually large magnetic susceptibility field gradient is obtained.

  12. Crocus sativus Petals: Waste or Valuable Resource? The Answer of High-Resolution and High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance.

    Science.gov (United States)

    Righi, Valeria; Parenti, Francesca; Tugnoli, Vitaliano; Schenetti, Luisa; Mucci, Adele

    2015-09-30

    Intact Crocus sativus petals were studied for the first time by high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy, revealing the presence of kinsenoside (2) and goodyeroside A (3), together with 3-hydroxy-γ-butyrolactone (4). These findings were confirmed by HR-NMR analysis of the ethanol extract of fresh petals and showed that, even though carried out rapidly, partial hydrolysis of glucopyranosyloxybutanolides occurs during extraction. On the other hand, kaempferol 3-O-sophoroside (1), which is "NMR-silent" in intact petals, is present in extracts. These results suggest to evaluate the utilization of saffron petals for phytopharmaceutical and nutraceutical purposes to exploit a waste product of massive production of commercial saffron and point to the application of HR-MAS NMR for monitoring bioactive compounds directly on intact petals, avoiding the extraction procedure and the consequent hydrolysis reaction.

  13. Characterization of Free Radicals By Electron Spin Resonance Spectroscopy in Biochars from Pyrolysis at High Heating Rates and at High Temperatures

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Jensen, Anker Degn; Larsen Andresen, Mogens

    of mathematical models that can predict yields, composition and rates of product (char, tar, light gases) formation from fast pyrolysis. The modeling of cross-linking and polymerization reactions in biomass pyrolysis includes the formation of free radicals and their disappearance. Knowledge about these radical...... reactions is important in order to achieve the high fuel conversion at short residence times. However, little is known about the extent of free radical reactions in pulverized biomass at fast pyrolysis conditions.The concentration and type of free radicals from the decay (termination stage) of pyrolysis...... reactor, an entrained-flow reactor, and a tubular reactor. The radical concentrations in the chars from the decay stage range up between 7x1018 and 1.5x1019 spins g-1.The results indicated that any differences in the biomass major constituents (cellulose, hemicellulose, lignin) had a minor effect...

  14. Experimental Flight Characterization of Spin Stabilized Projectiles at High Angle of Attack

    Science.gov (United States)

    2017-08-07

    about 2 m from the spark range entrance. The propelling charge used 1.18 kg of M1 propellant with about 30 gr of black powder for the primer. These...along with some wake flow structures trailing the body. Approved for public release; distribution is unlimited. 7 Fig. 2 Orthogonal...continuous polynomial does not represent the underlying flow phenomena at high angle of attack. There is little data in the literature on the axial force for

  15. Alkylation of a bioinspired high spin Ni(II)N{sub 3}S{sub 2} complex with bifunctional reagents

    Energy Technology Data Exchange (ETDEWEB)

    Chohan, B. S., E-mail: bsc12@psu.edu [The Pennsylvania State University, Department of Chemistry (United States)

    2013-12-15

    Crystal structures of two S-alkylated complexes generated from the reaction of iodoacetamide and iodoethanol with an air and moisture sensitive high spin Ni(II) pentacoordinate triaminodithiolate complex, 1 are determined by X-ray structure analysis. Crystals of complex 2, [NiC{sub 16}H{sub 31}N{sub 5}O{sub 2}S{sub 2}]I{sub 2}, are triclinic, sp. gr. P-bar1 , Z = 2. Crystals of complex 3, [NiC{sub 16}H{sub 28}N{sub 3}O{sub 2}S{sub 2}]I{sub 2}, are monoclinic, sp. gr. P2{sub 1}/c, Z = 4. Structures of complexes 2 and 3 are very similar: one of the S-acetamide (2) or S-ethanol (3) groups coordinates to the Ni center through the oxygen atom forming N{sub 3}S{sub 2}O hexacoordination; the other group remains unbound to the Ni and left dangling. Crystal packing shows that complexes 2 and 3 interact with the iodide counterions, and that only complex 2 interact with neighboring molecules; some of these close intermolecular contacts include H-bonding interactions.

  16. A comparative study of the infrared and Raman spectra of aniline and o-, m-, p-phenylenediamine isomers.

    Science.gov (United States)

    Badawi, Hassan M; Förner, Wolfgang; Ali, Shaikh A

    2013-08-01

    The structural stabilities of o-, m- and p-phenylenediamine (PDA) isomers were investigated by DFT-B3LYP and ab initio MP2 calculations with the 6-311G(**) basis set. From the calculations the three isomers were predicted to exist predominantly in an anti (transoid) structure. In the o-isomer, the syn (cisoid) form is calculated to turn to the anti (transoid) form with the two HNCC torsional angles of about 44 and 10° and the NH2 inversion barrier of 3-4 kcal/mol. The CCNH torsional angles in the m-PDA and p-PDA isomers were calculated to be about 25-26° as compared to 20° in aniline. A comparison of the Raman spectra of the three PDA-s with those of aniline shows the high sensitivity of the ring breathing mode to the nature of substituents in the aniline ring. The vibrational wavenumbers were computed at the DFT-B3LYP for aniline and the o-, m- and p-PDA isomers for the purpose of comparison. Complete vibrational assignments were made on the basis of normal coordinate analyses and potential energy distributions for aniline and the o-, m- and p-PDA molecules. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Surface Interactions and Confinement of Methane: A High Pressure Magic Angle Spinning NMR and Computational Chemistry Study

    Energy Technology Data Exchange (ETDEWEB)

    Ok, Salim; Hoyt, David W.; Andersen, Amity; Sheets, Julie; Welch, Susan A.; Cole, David R.; Mueller, Karl T.; Washton, Nancy M.

    2017-01-18

    Characterization and modeling of the molecular-level behavior of simple hydrocarbon gases, such as methane, in the presence of both nonporous and nano-porous mineral matrices allows for predictive understanding of important processes in engineered and natural systems. In this study, changes in local electromagnetic environments of the carbon atoms in methane under conditions of high pressure (up to 130 bar) and moderate temperature (up to 346 K) were observed with 13C magic-angle spinning (MAS) NMR spectroscopy while the methane gas was mixed with two model solid substrates: a fumed non-porous, 12 nm particle size silica and a mesoporous silica with 200 nm particle size and 4 nm average pore diameter. Examination of the interactions between methane and the silica systems over temperatures and pressures that include the supercritical regime was allowed by a novel high pressure MAS sample containment system, which provided high resolution spectra collected under in situ conditions. For pure methane, no significant thermal effects were found for the observed 13C chemical shifts at all pressures studied here (28.2 bar, 32.6 bar, 56.4 bar, 65.1 bar, 112.7 bar, and 130.3 bar). However, the 13C chemical shifts of resonances arising from confined methane changed slightly with changes in temperature in mixtures with mesoporous silica. The chemical shift values of 13C nuclides in methane change measurably as a function of pressure both in the pure state and in mixtures with both silica matrices, with a more pronounced shift when meso-porous silica is present. Molecular-level simulations utilizing GCMC, MD and DFT confirm qualitatively that the experimentally measured changes are attributed to interactions of methane with the hydroxylated silica surfaces as well as densification of methane within nanopores and on pore surfaces.

  18. Crossover from Spin Accumulation into Interface States to Spin Injection in the Germanium Conduction Band

    Science.gov (United States)

    Rojas-Sanchez, Juan-Carlos; Jain, Abhinav; Cubukcu, Murat; Peiro, Julian; Le Breton, Jean-Christophe; Prestat, Eric; Vergnaud, Céline; Bayle-Guillemaud, Pascale; Vila, Laurent; Attané, Jean-Philippe; Augendre, Emmanuel; Gambarelli, Serge; Jaffrès, Henri; George, Jean-Marie; Jamet, Matthieu

    2013-03-01

    Spin injection into semiconductors is crucial for exploring spin physics and new spintronic devices. Ge is of great interest for high carrier mobilities, long spin diffusion length and large spin-orbit coupling to perform electric field spin manipulation. However the exact role of interface states in spin injection mechanism in n-Ge has not been clarified yet. Here we show a clear transition from spin accumulation into interface states to spin injection in the Ge conduction band. For this purpose, we have grown CoFeB/MgO as a spin injector on Germanium On Insulator. We observe spin signal amplification at low temperature due to spin accumulation into interface states. At 150 K, we find a clear transition to spin injection in the conduction band up to room temperature: the measured spin signal is compatible with the spin diffusion model. We could in particular demonstrate spin signal modulation applying a back gate voltage and spin-pumping by the ferromagnetic resonance of the CoFeB layer which are clear manifestations of spin accumulation in the Ge conduction band.

  19. Low energy nuclear spin excitations in Ho metal investigated by high resolution neutron spectroscopy.

    Science.gov (United States)

    Chatterji, Tapan; Jalarvo, Niina

    2013-04-17

    We have investigated the low energy excitations in metallic Ho by high resolution neutron spectroscopy. We found at T = 3 K clear inelastic peaks in the energy loss and energy gain sides, along with the central elastic peak. The energy of this low energy excitation, which is 26.59 ± 0.02 μeV at T = 3 K, decreased continuously and became zero at TN ≈ 130 K. By fitting the data in the temperature range 100-127.5 K with a power law we obtained the power-law exponent β = 0.37 ± 0.02, which agrees with the expected value β = 0.367 for a three-dimensional Heisenberg model. Thus the energy of the low energy excitations can be associated with the order parameter.

  20. Quantum Spin Models for Copper Oxide Chains in High-T{sub c} Superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haugerud, H.

    1996-12-31

    This doctoral thesis presents some of the most important features of high temperature superconductors, emphasizing the properties of YBa{sub 2}Cu{sub 3}O{sub 6+x} (YBCO). The family of Hubbard-like models is considered and a simplified version of the Emery model derived. This model is applied to fermions on a cyclic chain and solved analytically in the strong correlation limit. For realistic model parameter values the effects of an external magnetic field is investigated by numerical diagonalization. Applying the Emery model to finite cyclic Cu-O chains it is shown that the behaviour of the chains is typical for a 1D Fermi-liquid. The relatively small difference between the values of the local charge and the local magnetic moment indicates that the degree of correlation in this system is very high. The ground state of the Emery model is shown to be antiferromagnetic for half and quarter filling, resembling the ground state of the Heisenberg model. The role of the ensemble of Cu-O chain fragments of the oxygen deficient planes of YBCO is addressed. By applying the Emery model to short Cu-O chains and calculating the free energy of the chains, the parameters of an Ising like lattice gas model are estimated. Several thermodynamical quantities are calculated by applying Monte Carlo technique to the model. The charge transfer from the chains to the planes is shown to correspond to the measured values of T{sub c}. The phase diagram and the average chain length agree well with experiments. The model is also capable of explaining the behaviour of the REBCO series of superconductors, where RE are various rare earth ions. A framework for simultaneously visualizing and computing numerical quantities from lattice simulations is presented and illustrated. 195 refs., 69 figs., 4 tabs.

  1. High resolution NMR study of T1 magnetic relaxation dispersion. III. Influence of spin 1/2 hetero-nuclei on spin relaxation and polarization transfer among strongly coupled protons

    NARCIS (Netherlands)

    Korchak, S.E.; Ivanov, K.L.; Pravdivtsev, A.N.; Yurkovskaya, A.V.; Kaptein, R.|info:eu-repo/dai/nl/074334603; Vieth, H.-M.

    2012-01-01

    Effects of spin-spin interactions on the nuclear magnetic relaxation dispersion (NMRD) of protons were studied in a situation where spin ½ hetero-nuclei are present in the molecule. As in earlier works [K. L. Ivanov, A. V. Yurkovskaya, and H.-M. Vieth, J. Chem. Phys. 129, 234513

  2. Incipient- and Developed-Spin and Recovery Characteristics of a Modern High-Speed Fighter Design with Low Aspect Ratio as Determined from Dynamic-Model Tests

    Science.gov (United States)

    Lee, Henry A.; Libbey, Charles E.

    1961-01-01

    Incipient- and developed-spin and recovery characteristics of a modern high-speed fighter design with low aspect ratio have been investigated by means of dynamic model tests. A 1/7-scale radio-controlled model was tested by means of drop tests from a helicopter. Several 1/25-scale models with various configuration changes were tested in the Langley 20-foot free-spinning tunnel. Model results indicated that generally it would be difficult to obtain a developed spin with a corresponding airplane and that either the airplane would recover of its own accord from any poststall motion or the poststall motion could be readily terminated by proper control technique. On occasion, however, the results indicated that if a post-stall motion were allowed to continue, a fully developed spin might be obtainable from which recovery could range from rapid to no recovery at all, even when optimum control technique was used. Satisfactory recoveries could be obtained with a proper-size tail parachute or strake, application of pitching-, rolling-, or yawing-moment rockets, or sufficient differential deflection of the horizontal tail.

  3. Vaporization of Kitaev spin liquids.

    Science.gov (United States)

    Nasu, Joji; Udagawa, Masafumi; Motome, Yukitoshi

    2014-11-07

    The quantum spin liquid is an exotic quantum state of matter in magnets. This state is a spin analog of liquid helium that does not solidify down to the lowest temperature due to strong quantum fluctuations. In conventional fluids, the liquid and gas possess the same symmetry and adiabatically connect to each other by bypassing the critical end point. We find that the situation is qualitatively different in quantum spin liquids realized in a three-dimensional Kitaev model; both gapless and gapped quantum spin liquid phases at low temperatures are always distinguished from the high-temperature paramagnet (spin gas) by a phase transition. The results challenge the common belief that the absence of thermodynamic singularity down to the lowest temperature is a symptom of a quantum spin liquid.

  4. Spin liquids in frustrated magnets.

    Science.gov (United States)

    Balents, Leon

    2010-03-11

    Frustrated magnets are materials in which localized magnetic moments, or spins, interact through competing exchange interactions that cannot be simultaneously satisfied, giving rise to a large degeneracy of the system ground state. Under certain conditions, this can lead to the formation of fluid-like states of matter, so-called spin liquids, in which the constituent spins are highly correlated but still fluctuate strongly down to a temperature of absolute zero. The fluctuations of the spins in a spin liquid can be classical or quantum and show remarkable collective phenomena such as emergent gauge fields and fractional particle excitations. This exotic behaviour is now being uncovered in the laboratory, providing insight into the properties of spin liquids and challenges to the theoretical description of these materials.

  5. Postoperative arachnoiditis diagnosed by high resolution fast spin-echo MRI of the lumbar spine

    Energy Technology Data Exchange (ETDEWEB)

    Fitt, G.J. [St. Mary`s Hospital, London (United Kingdom). Dept. of Radiology; Stevens, J.M. [St. Mary`s Hospital, London (United Kingdom). Dept. of Radiology]|[National Hospital for Neurology and Neurosurgery, London (United Kingdom)

    1995-02-01

    Chronic adhesive arachnoiditis is cited as an important cause of recurrent pain and disability after extradural lumbar disc surgery. Myelography using oil-based or ionic water-soluble contrast media was a major contributing factor, and it was not possible to distinguish the prevalence of arachnoiditis probably due to surgery alone. Today it should be possible to make this distinction, which was the purpose of this study. Using high-resolution MRI in 129 patients symptomatic at least 1 year after surgery, a prevalence of arachnoiditis of 20% was found, which dropped to 3% when patients who had undergone oil-based myelography were excluded. Arachnoiditis was diffuse in 88% and focal in 12%. When oil-based media were involved it was focal in 13%, and when not, in one of three cases. It was concluded that arachnoiditis does occur after extradural lumbar disc surgery independently of the use of some myelographic contrast media, and that it may be diffuse or confined only to the operated level. Its prevalence was estimated at 4.6%, four cases focal and two cases diffuse. The causes and clinical significance can only be the subject of speculation. (orig.)

  6. Spin ejector

    Science.gov (United States)

    Andersen, John A.; Flanigan, John J.; Kindley, Robert J.

    1978-01-01

    The disclosure relates to an apparatus for spin ejecting a body having a flat plate base containing bosses. The apparatus has a base plate and a main ejection shaft extending perpendicularly from the base plate. A compressible cylindrical spring is disposed about the shaft. Bearings are located between the shaft and the spring. A housing containing a helical aperture releasably engages the base plate and surrounds the shaft bearings and the spring. A piston having an aperture follower disposed in the housing aperture is seated on the spring and is guided by the shaft and the aperture. The spring is compressed and when released causes the piston to spin eject the body.

  7. Molecular spinning by a chiral train of short laser pulses

    Science.gov (United States)

    Floß, Johannes; Averbukh, Ilya Sh.

    2012-12-01

    We provide a detailed theoretical analysis of molecular rotational excitation by a chiral pulse train, a sequence of linearly polarized pulses with the polarization direction rotating from pulse to pulse by a controllable angle. Molecular rotation with a preferential rotational sense (clockwise or counterclockwise) can be excited by this scheme. We show that the directionality of the rotation is caused by quantum interference of different excitation pathways. The chiral pulse train is capable of selective excitation of molecular isotopologs and nuclear spin isomers in a mixture. We demonstrate this using 14N2 and 15N2 as examples for isotopologs and para- and ortho-nitrogen as examples for nuclear-spin isomers.

  8. New shape isomer in the self-conjugate nucleus 72Kr.

    Science.gov (United States)

    Bouchez, E; Matea, I; Korten, W; Becker, F; Blank, B; Borcea, C; Buta, A; Emsallem, A; de France, G; Genevey, J; Hannachi, F; Hauschild, K; Hürstel, A; Le Coz, Y; Lewitowicz, M; Lucas, R; Negoita, F; de Oliveira Santos, F; Pantelica, D; Pinston, J; Rahkila, P; Rejmund, M; Stanoiu, M; Theisen, Ch

    2003-02-28

    A new isomeric 0(+) state was identified as the first excited state in the self-conjugate (N=Z) nucleus 72Kr. By combining for the first time conversion-electron and gamma-ray spectroscopy with the production of metastable states in high-energy fragmentation, the electric-monopole decay of the new isomer to the ground state was established. The new 0(+) state is understood as the band head of the known prolate rotational structure, which strongly supports the interpretation that 72Kr is one of the rare nuclei having an oblate-deformed ground state. This observation gives in fact the first evidence for a shape isomer in a N=Z nucleus.

  9. High resolution NMR study of T1 magnetic relaxation dispersion. III. Influence of spin 1/2 hetero-nuclei on spin relaxation and polarization transfer among strongly coupled protons.

    Science.gov (United States)

    Korchak, Sergey E; Ivanov, Konstantin L; Pravdivtsev, Andrey N; Yurkovskaya, Alexandra V; Kaptein, Robert; Vieth, Hans-Martin

    2012-09-07

    Effects of spin-spin interactions on the nuclear magnetic relaxation dispersion (NMRD) of protons were studied in a situation where spin ½ hetero-nuclei are present in the molecule. As in earlier works [K. L. Ivanov, A. V. Yurkovskaya, and H.-M. Vieth, J. Chem. Phys. 129, 234513 (2008); S. E. Korchak, K. L. Ivanov, A. V. Yurkovskaya, and H.-M. Vieth, ibid. 133, 194502 (2010)], spin-spin interactions have a pronounced effect on the relaxivity tending to equalize the longitudinal relaxation times once the spins become strongly coupled at a sufficiently low magnetic field. In addition, we have found influence of (19)F nuclei on the proton NMRD, although in the whole field range, studied protons and fluorine spins were only weakly coupled. In particular, pronounced features in the proton NMRD were found; but each feature was predominantly observed only for particular spin states of the hetero-nuclei. The features are explained theoretically; it is shown that hetero-nuclei can affect the proton NMRD even in the limit of weak coupling when (i) protons are coupled strongly and (ii) have spin-spin interactions of different strengths with the hetero-nuclei. We also show that by choosing the proper magnetic field strength, one can selectively transfer proton spin magnetization between spectral components of choice.

  10. Spin canting observation and cation distribution in CoFe{sub 2−x}In{sub x}O{sub 4} (0.0 ⩽ x ⩽ 1.0) ferrites through low temperature–high field Mössbauer spectral study

    Energy Technology Data Exchange (ETDEWEB)

    Pandit, Rabia, E-mail: rabiabest@gmail.com [Department of Physics, National Institute of Technology, Hamirpur (H.P) 177 005 (India); Sharma, K.K.; Kaur, Pawanpreet [Department of Physics, National Institute of Technology, Hamirpur (H.P) 177 005 (India); Reddy, V.R. [UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore 4520 17 (India); Kumar, Ravi [Centre for Material Science and Engineering, National Institute of Technology, Hamirpur (H.P) 177 005 (India); Shah, Jyoti [National Physical Laboratory, New Delhi 110 012 (India)

    2014-05-01

    Highlights: • Rietveld refinement of CoIn{sub x}Fe{sub 2−x}O{sub 4} samples confirm single phase spinel structure. • The in-field Mössbauer study reveals canted spin structures in CoIn{sub x}Fe{sub 2−x}O{sub 4} ferrites. • In-field Mössbauer study is in line with magnetization measurements. • Cation distribution matches well with experimental integrated intensity ratios. • Shifting of resonance peaks to high frequencies is useful for industrial purposes. - Abstract: In the present work, In{sup 3+} substituted cobalt ferrites (CoFe{sub 2−x}In{sub x}O{sub 4}, x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) have been synthesized via solid-state reaction technique. The Rietveld fitted X-ray diffraction patterns confirm the formation of single phase cubic spinel structure with space group Fd3{sup ¯}m for all the samples, with additional slight traces of secondary phase for x = 0.6, 0.8 and 1.0 samples. The low temperature (5 K)–high field Mössbauer (5T) spectra are analyzed in detail for probing the magnetic properties of Fe based In{sup 3+} substituted cobalt ferrites. The canted spin structures associated with Fe{sup 3+} ions both at A- and B-sites in the presence of external magnetic field of 5T have been noticed in all the samples. A fair agreement is obtained between the experimental integrated intensity ratios of {sup 57}Fe Mössbauer spectra at A- and B-sites and those calculated on the basis of cation distribution. The effect of In{sup 3+} substitution on various Mössbauer parameters viz hyperfine field distribution, isomer shift, quadrupole splitting and the line width has also been noticed. The magnetization measurements performed at low temperature also reveal the canted spin structures in all the samples. The variations in initial permeability over a wide range of frequency (125 kHz–30 MHz) at 300 K have also been recorded. The initial permeability study reveals the occurrence of resonance phenomenon at very high frequencies which widens the area

  11. High temperature spin state transitions in misfit-layered Ca{sub 3}Co{sub 4}O{sub 9}

    Energy Technology Data Exchange (ETDEWEB)

    Altin, S.; Aksan, M.A., E-mail: mehmet.aksan@inonu.edu.tr; Bayri, A.

    2014-02-25

    Highlights: • Ca{sub 3}Co{sub 4}O{sub 9} system has been fabricated using the solid-state technique. • There is an anomaly in magnetic the susceptibility χ between 680 and 920 K. • The anomaly is related to a critical threshold number of the high spin Co-ions. • The anomaly was also observed in the B and Sb-substituted Ca{sub 3}Co{sub 4}O{sub 9}. -- Abstract: This study reports high temperature magnetic properties of the unsubstituted one together with B and Sb-substituted Ca{sub 3}Co{sub 4}O{sub 9} system. The measured data indicated that there is an anomaly in the magnetic susceptibility, χ, between 680 and 920 K. It is believed that this anomaly is related to a critical threshold number of the high spin Co-ions such that when this threshold number is achieved, some exchange interactions between Co{sup 3+} and Co{sup 4+} take place which causes an abrupt increase in the χ–T curve. The anomaly was further investigated with B and Sb-substitutions. It is realized that both dopants promote more Co-ions in the rock salt unit cell to high spin state.

  12. Intrinsic parton motion soft mechanisms and the longitudinal spin asymmetry ALL in high energy pp → πX

    Science.gov (United States)

    Anselmino, M.; Boglione, M.; D'Alesio, U.; Leader, E.; Melis, S.; Murgia, F.

    2009-01-01

    The longitudinal double spin asymmetry ALL in the reaction pp → πX has been measured at RHIC with extremely interesting consequences. If the gluon polarization in a proton were as big as needed to resolve the famous 'spin crisis' then ALL would be large and positive. Latest RHIC results indicate that ALL is small and disfavour large positive values of the gluon polarization. We examine whether the soft mechanisms (Collins, Sivers, Boer-Mulders), essential for generating transverse single spin asymmetries, have any significant influence on ALL, and whether they could alter the conclusion that the gluon polarization is necessarily small. It turns out that the contribution from these effects is essentially negligible.

  13. Spin Superfluidity in Biaxial Antiferromagnetic Insulators

    Science.gov (United States)

    Qaiumzadeh, Alireza; Skarsvâg, Hans; Holmqvist, Cecilia; Brataas, Arne

    2017-03-01

    Antiferromagnets may exhibit spin superfluidity since the dipole interaction is weak. We seek to establish that this phenomenon occurs in insulators such as NiO, which is a good spin conductor according to previous studies. We investigate nonlocal spin transport in a planar antiferromagnetic insulator with a weak uniaxial anisotropy. The anisotropy hinders spin superfluidity by creating a substantial threshold that the current must overcome. Nevertheless, we show that applying a high magnetic field removes this obstacle near the spin-flop transition of the antiferromagnet. Importantly, the spin superfluidity can then persist across many micrometers, even in dirty samples.

  14. Quantitative ARG microimaging studies of two muscarinic antagonist isomers: Blocking and the effects of cocaine

    Energy Technology Data Exchange (ETDEWEB)

    Som, P.; Wang, G.J.; Oster, Z.H. [Oak Ridge National Lab., TN (United States)] [and others

    1994-05-01

    The distribution of the racemic mixture of IQNP(1-Azabicyclo [2-2-2] oct-3-yl alpha-hydroxy-alpha-(1-iodo-propen-3-yl)-alpha-phenylacetate), a muscarinic antagonist was described earlier. Recently, the radioiodinated Z and E-(R,R) IQNP isomers have been prepared. Quantitative ARG studies using the Z and E isomers were performed in control rats and after pretreatment with ({plus_minus}) QNB or cocaine. High uptake of (Z)-IQNP was seen in the heart and brain with GI and urinary excretion. Lung uptake was lower than with the racemic IQNP. (Z)-IQNP uptake was maximal at 15 min p.i. with homogeneous distribution in the heart. In the brain, highest uptake was in the caudate, cortex, hippocampus, pons and thalamus. (Z)-IQNP showed higher cerebellar uptake and lower cortical uptake compared to (E)-IQNP. Clearance from brain was slower than bean. Heart and brain uptake of (E)-IQNP were markedly lower than the Z isomer. After QNB pretreatment, almost complete blocking of (Z)-IQNP uptake in heart and brain occurred. Cocaine did not significantly affect the distribution of IQNP. These data indicate that (Z)-IQNP has high affinity for the M2 muscarinic receptor with potential for brain and heart imaging. Cocaine appears to have little effect on the muscarinic-cholinergic receptors in the brain and heart.

  15. L-valley electrons in SiGe heterostructures: highly anisotropic and tunable Zeeman and Rashba-like spin splittings

    Science.gov (United States)

    Kiselev, A. A.; Baron, F. A.; Kim, K. W.; Wang, K. L.; Yablonovitch, E.

    2005-06-01

    We have conducted a detailed and systematic analysis of Zeeman and Rashba-like (structure-asymmetry-induced) spin splittings in SiGe heterostructures. The calculations were performed in the framework of a relevant kp model, developed specifically for the L point states of the group IV semiconductors. Effects of the alloy composition, crystallographic orientation, spatial confinement, strain, and electric field are accounted for and documented for a realistic structure design. Notable Rashba effect, considerable anisotropy and deviation of the g tensor components from their respective bulk values make the SiGe structures a friendly choice for the effective spin manipulation.

  16. An Ion Gel as a Low-Cost, Spin-Coatable, High-Capacitance Dielectric for Electrowetting-on-Dielectric (EWOD).

    Science.gov (United States)

    Narasimhan, Vinayak; Park, Sung-Yong

    2015-08-04

    For many practical electrowetting-on-dielectric (EWOD) applications, the use of high-capacitance dielectric materials is critically demanded to induce a large surface tension modulation. Thin-film dielectric layers such as Parylene C, silicon dioxide (SiO2), and aluminum oxide (Al2O3) have been commonly used for EWOD. However, these dielectric materials are fabricated by conventional integrated circuit (IC) processes which are typically time-consuming and require complex and expensive laboratory setups such as high-vacuum facilities. In this article, a novel ion gel material was demonstrated as a spin-coatable and high-capacitance dielectric for low-cost EWOD applications. The ion gel offers a 2 or 3 order higher capacitance (c ≈ 10 μF/cm(2)) than conventional dielectrics commonly used for EWOD while being fabricated through a simple low-cost spin-coating process. We discuss the fundamentals of an ion gel dielectric, its fabrication process of spin coating, and the interaction with a hydrophobic layer for practical EWOD applications. The ion gel films, which consist of a copolymer, poly(vinylidene fluoride-co-hexafluoropropylene) [P(VDF-HFP)], and an ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM][TFSI], were successfully deposited on ITO substrates by using a simple spin-coating process. The experimental demonstrations validated the theoretical modeling of the ion gel layer as a high-capacitance dielectric. The EWOD performance of the ion gel samples was compared to that of other conventional dielectric materials to show the performance improvement.

  17. Comparison of three high-flow single-stage impaction-based air samplers for bacteria quantification: DUO SAS SUPER 360, SAMPL'AIR and SPIN AIR

    OpenAIRE

    Sánchez-Muñoz, Marta; Muñoz-Vicente, María; Cobas, Guillermo; Portela, Raquel; Amils, Ricardo; Sánchez, Benigno

    2012-01-01

    Indoor Air Quality (IAQ) can be significantly deteriorated by high levels of bioaerosols that may cause adverse health effects in building occupants. There is no standard method for the quantification of this kind of pollutants and several protocols and sampling devices are used. The aim of this work was to compare three commonly used portable air samplers available in the market. DUO SAS SUPER 360, SAMPL'AIR and SPIN AIR units were tested simultaneously for bacteria quantification in a labor...

  18. Spin rotation and oscillations for high energy particles in a crystal and possibility to measure the quadrupole moments and tensor polarizabilities of elementary particles and nuclei

    OpenAIRE

    Baryshevsky, V. G.; Gurinovich, A. A.

    2005-01-01

    It is shown that particle motion in a bent (straight) crystal is accompanied by particle spin rotation and oscillations that allows to measure the tensor electric and magnetic polarizabilities of nuclei and elementary particles. It is shown that channelling of particles in either straight or bent crystal with the polarized nuclei could be used both to analyze polarization of high energy particles and polarize them.

  19. Switching ferromagnetic spins by an ultrafast laser pulse: Emergence of giant optical spin-orbit torque

    Science.gov (United States)

    Zhang, G. P.; Bai, Y. H.; George, Thomas F.

    2016-09-01

    Faster magnetic recording technology is indispensable to massive data storage and big data sciences. All-optical spin switching offers a possible solution, but at present it is limited to a handful of expensive and complex rare-earth ferrimagnets. The spin switching in more abundant ferromagnets may significantly expand the scope of all-optical spin switching. Here by studying 40000 ferromagnetic spins, we show that it is the optical spin-orbit torque that determines the course of spin switching in both ferromagnets and ferrimagnets. Spin switching occurs only if the effective spin angular momentum of each constituent in an alloy exceeds a critical value. Because of the strong exchange coupling, the spin switches much faster in ferromagnets than weakly coupled ferrimagnets. This establishes a paradigm for all-optical spin switching. The resultant magnetic field (65 T) is so big that it will significantly reduce high current in spintronics, thus representing the beginning of photospintronics.

  20. Spinning worlds

    NARCIS (Netherlands)

    Schwarz, H.

    2017-01-01

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

  1. Magnetic moments of K isomers as indicators of octupole collectivity

    Energy Technology Data Exchange (ETDEWEB)

    Minkov, N. [Bulgarian Academy of Sciences, Institute of Nuclear Research and Nuclear Energy, Sofia (Bulgaria); University of Surrey, Department of Physics, Guildford (United Kingdom); Walker, P.M. [University of Surrey, Department of Physics, Guildford (United Kingdom); CERN, Geneva (Switzerland)

    2012-06-15

    The relation between the quadrupole-octupole deformation and the structure of high-K isomers in heavy even-even nuclei is studied through a reflection asymmetric deformed shell model including a BCS procedure with constant pairing interaction. Two-quasiparticle states with K{sup {pi}} = 4 {sup -}, 5 {sup -}, 6 {sup -}, 6 {sup +} and 7 {sup -} are considered in the region of actinide nuclei (U, Pu and Cm) and rare-earth nuclei (Nd, Sm and Gd). The behaviour of two-quasiparticle energies and magnetic dipole moments of these configurations is examined over a wide range in the plane of quadrupole and octupole deformations ({beta}{sub 2} and {beta}{sub 3}). In all considered actinide nuclei, the calculations show that there is pronounced sensitivity of the magnetic moments to the octupole deformation. In the rare-earth nuclei, the calculations for {sup 154,} {sup 156}Gd show stronger sensitivity of the magnetic moment to the octupole deformation than in the other considered cases. (orig.)

  2. Gate-tunable black phosphorus spin valve with nanosecond spin lifetimes

    Science.gov (United States)

    Avsar, Ahmet; Tan, Jun Y.; Kurpas, Marcin; Gmitra, Martin; Watanabe, Kenji; Taniguchi, Takashi; Fabian, Jaroslav; Özyilmaz, Barbaros

    2017-09-01

    Two-dimensional materials offer new opportunities for both fundamental science and technological applications, by exploiting the electron's spin. Although graphene is very promising for spin communication due to its extraordinary electron mobility, the lack of a bandgap restricts its prospects for semiconducting spin devices such as spin diodes and bipolar spin transistors. The recent emergence of two-dimensional semiconductors could help overcome this basic challenge. In this letter we report an important step towards making two-dimensional semiconductor spin devices. We have fabricated a spin valve based on ultrathin (~5 nm) semiconducting black phosphorus (bP), and established fundamental spin properties of this spin channel material, which supports all electrical spin injection, transport, precession and detection up to room temperature. In the non-local spin valve geometry we measure Hanle spin precession and observe spin relaxation times as high as 4 ns, with spin relaxation lengths exceeding 6 μm. Our experimental results are in a very good agreement with first-principles calculations and demonstrate that the Elliott-Yafet spin relaxation mechanism is dominant. We also show that spin transport in ultrathin bP depends strongly on the charge carrier concentration, and can be manipulated by the electric field effect.

  3. Design of a triple resonance magic angle sample spinning probe for high field solid state nuclear magnetic resonance

    Science.gov (United States)

    Martin, Rachel W.; Paulson, Eric K.; Zilm, Kurt W.

    2003-06-01

    Standard design and construction practices used in building nuclear magnetic resonance (NMR) probes for the study of solid state samples become difficult if not entirely impractical to implement as the 1H resonance frequency approaches the self resonance frequency of commercial capacitors. We describe an approach that utilizes short variable transmission line segments as tunable reactances. Such an approach effectively controls stray reactances and provides a higher Q alternative to ceramic chip capacitors. The particular probe described is built to accommodate a 2.5 mm magic angle spinning rotor system, and is triply tuned to 13C, 15N, and 1H frequencies for use at 18.8 T (200, 80, and 800 MHz, respectively). Isolation of the three radio frequency (rf) channels is achieved using both a rejection trap and a transmission line notch filter. The compact geometry of this design allows three channels with high power handling capability to fit in a medium bore (63 mm) magnet. Extended time variable temperature operation is integral to the mechanical design, enabling the temperature control necessary for investigation of biological macromolecules. Accurate measurement of the air temperature near the sample rotor is achieved using a fiber optic thermometer, which does not interfere with the rf electronics. We also demonstrate that acceptable line shapes are only readily achieved using zero magnetic susceptibility wire in construction of the sample coil. Computer simulation of the circuit aided in the physical design of the probe. Representative data illustrating the efficiency, rf homogeneity, and signal to noise factor of the probe are presented.

  4. New State of Matter: Heavy Fermion Systems, Quantum Spin Liquids, Quasicrystals, Cold Gases, and High-Temperature Superconductors

    Science.gov (United States)

    Shaginyan, V. R.; Stephanovich, V. A.; Msezane, A. Z.; Schuck, P.; Clark, J. W.; Amusia, M. Ya.; Japaridze, G. S.; Popov, K. G.; Kirichenko, E. V.

    2017-12-01

    We report on a new state of matter manifested by strongly correlated Fermi systems including various heavy fermion (HF) metals, two-dimensional quantum liquids such as ^3He films, certain quasicrystals, and systems behaving as quantum spin liquids. Generically, these systems can be viewed as HF systems or HF compounds, in that they exhibit typical behavior of HF metals. At zero temperature, such systems can experience a so-called fermion condensation quantum phase transition (FCQPT). Combining analytical considerations with arguments based entirely on experimental grounds, we argue and demonstrate that the class of HF systems is characterized by universal scaling behavior of their thermodynamic, transport, and relaxation properties. That is, the quantum physics of different HF compounds is found to be universal, emerging irrespective of the individual details of their symmetries, interactions, and microscopic structure. This observed universal behavior reveals the existence of a new state of matter manifest in HF compounds. We propose a simple, realistic model to study the appearance of flat bands in two-dimensional ensembles of ultracold fermionic atoms, interacting with coherent resonant light. It is shown that signatures of these flat bands may be found in peculiarities in their thermodynamic and spectroscopic properties. We also show that the FCQPT, in generating flat bands and altering Fermi surface topology, is an essential progenitor of the exotic behavior of the overdoped high-temperature superconductors represented by La_{2-x}SrxxCuO_4, whose superconductivity differs from that predicted by the classical Bardeen-Cooper-Schrieffer theory. The theoretical results presented are in good agreement with recent experimental observations, closing the colossal gap between these empirical findings and Bardeen-Cooper-Schrieffer-like theories.

  5. New State of Matter: Heavy Fermion Systems, Quantum Spin Liquids, Quasicrystals, Cold Gases, and High-Temperature Superconductors

    Science.gov (United States)

    Shaginyan, V. R.; Stephanovich, V. A.; Msezane, A. Z.; Schuck, P.; Clark, J. W.; Amusia, M. Ya.; Japaridze, G. S.; Popov, K. G.; Kirichenko, E. V.

    2017-08-01

    We report on a new state of matter manifested by strongly correlated Fermi systems including various heavy fermion (HF) metals, two-dimensional quantum liquids such as ^3 He films, certain quasicrystals, and systems behaving as quantum spin liquids. Generically, these systems can be viewed as HF systems or HF compounds, in that they exhibit typical behavior of HF metals. At zero temperature, such systems can experience a so-called fermion condensation quantum phase transition (FCQPT). Combining analytical considerations with arguments based entirely on experimental grounds, we argue and demonstrate that the class of HF systems is characterized by universal scaling behavior of their thermodynamic, transport, and relaxation properties. That is, the quantum physics of different HF compounds is found to be universal, emerging irrespective of the individual details of their symmetries, interactions, and microscopic structure. This observed universal behavior reveals the existence of a new state of matter manifest in HF compounds. We propose a simple, realistic model to study the appearance of flat bands in two-dimensional ensembles of ultracold fermionic atoms, interacting with coherent resonant light. It is shown that signatures of these flat bands may be found in peculiarities in their thermodynamic and spectroscopic properties. We also show that the FCQPT, in generating flat bands and altering Fermi surface topology, is an essential progenitor of the exotic behavior of the overdoped high-temperature superconductors represented by La_{2-x}SrxxCuO_4 , whose superconductivity differs from that predicted by the classical Bardeen-Cooper-Schrieffer theory. The theoretical results presented are in good agreement with recent experimental observations, closing the colossal gap between these empirical findings and Bardeen-Cooper-Schrieffer-like theories.

  6. Spin currents, spin torques, and the concept of spin superfluidity

    OpenAIRE

    Rückriegel, Andreas; Kopietz, Peter

    2017-01-01

    In magnets with non-collinear spin configuration the expectation value of the conventionally defined spin current operator contains a contribution which renormalizes an external magnetic field and hence affects only the precessional motion of the spin polarization. This term, which has been named angular spin current by Sun and Xie [Phys. Rev B 72, 245305 (2005)], does not describe the translational motion of magnetic moments. We give a prescription how to separate these two types of spin tra...

  7. Highly frustrated spin-lattice models of magnetism and their quantum phase transitions: A microscopic treatment via the coupled cluster method

    Science.gov (United States)

    Bishop, R. F.; Li, P. H. Y.; Campbell, C. E.

    2014-10-01

    We outline how the coupled cluster method of microscopic quantum many-body theory can be utilized in practice to give highly accurate results for the ground-state properties of a wide variety of highly frustrated and strongly correlated spin-lattice models of interest in quantum magnetism, including their quantum phase transitions. The method itself is described, and it is shown how it may be implemented in practice to high orders in a systematically improvable hierarchy of (so-called LSUBm) approximations, by the use of computer-algebraic techniques. The method works from the outset in the thermodynamic limit of an infinite lattice at all levels of approximation, and it is shown both how the "raw" LSUBm results are themselves generally excellent in the sense that they converge rapidly, and how they may accurately be extrapolated to the exact limit, m → ∞, of the truncation index m, which denotes the only approximation made. All of this is illustrated via a specific application to a two-dimensional, frustrated, spin-half J1XXZ-J2XXZ model on a honeycomb lattice with nearest-neighbor and next-nearest-neighbor interactions with exchange couplings J1 > 0 and J2 ≡ κJ1 > 0, respectively, where both interactions are of the same anisotropic XXZ type. We show how the method can be used to determine the entire zero-temperature ground-state phase diagram of the model in the range 0 ≤ κ ≤ 1 of the frustration parameter and 0 ≤ Δ ≤ 1 of the spin-space anisotropy parameter. In particular, we identify a candidate quantum spin-liquid region in the phase space.

  8. Evolution of spin and valence states of (Pr0.7Sm0.3)0.7Ca0.3CoO3 at high temperature and high pressure

    Science.gov (United States)

    Chen, J. M.; Lee, J. M.; Haw, S. C.; Chen, S. A.; Hardy, V.; Guillou, F.; Chen, S. W.; Kuo, C. Y.; Pao, C. W.; Lee, J. F.; Hiraoka, N.; Ishii, H.; Tsuei, K. D.; Hu, Z.

    2014-07-01

    The changes of physical properties occurring at a first-order-like transition among a wide family of (Pr1-yLny)1-xCaxCoO3 compounds (Ln being a lanthanide) are controversially discussed as a transition of Co3+ ions from states of low spin (LS) to intermediate spin (IS), or from LS to a mixture of LS and high spin (HS). The debate also includes the nature of the spin state of Co4+, as well as the degree of valence shift between Pr3+ and Pr4+ which accompanies this transition. In the present paper, we investigated the evolution of spin and valence states of Co ions and the valence state of Pr ions in (Pr0.7Sm0.3)0.7Ca0.3CoO3, at high temperature up to 750 K and under pressure up to 36.5 GPa. For this purpose, the data of three spectroscopic techniques were combined: high-resolution Co K-edge partial-fluorescence-yield x-ray absorption spectra, Pr L2-edge x-ray absorption spectra, and Co Kβ x-ray emission spectra. The spectral weight transfer of the pre-edge peaks of the Co K-edge spectra reveals a continuous redistribution of 3d electrons between the t2g and eg levels of Co ions, reflecting a gradual increase of the average Co spin state upon heating. This is further confirmed by Co Kβ x-ray emission spectra, which show an increase of HS Co3+ population when increasing temperature from 300 to 750 K. Applying high pressure at 300 K, the Co Kβ x-ray emission spectra indicate a relatively sharp increase of LS Co3+ population below 4 GPa. Pr L2-edge x-ray absorption spectra of (Pr0.7Sm0.3)0.7Ca0.3CoO3 exhibit a valence-state transition from Pr3+ to Pr3.26+, occurring predominantly upon applying pressure in the range ˜4 to ˜12 GPa. Owing to the charge balance, increasing pressure in this regime induces complex valence and spin-state transitions within the Co ions. Moreover, at high enough pressure, it is found that the Co4+ can also undergo a spin-state transition (from IS to LS), in addition to that affecting the Co3+ (HS to LS).

  9. The First Transverse Single Spin Measurement in High Energy Polarized Proton-Nucleus Collision at the PHENIX experiment at RHIC

    Science.gov (United States)

    Nakagawa, I.

    2016-08-01

    Large single spin asymmetries in very forward neutron production seen using the PHENIX zero-degree calorimeters are a long established feature of transversely polarized proton-proton collisions at RHIC. Neutron production near zero degrees is well described by the one-pion exchange framework. The absorptive correction to the OPE generates the asymmetry as a consequence of a phase shift between the spin flip and non-spin flip amplitudes. However, the amplitude predicted by the OPE is too small to explain the large observed asymmetries. A model introducing interference of pion and a 1-Reggeon exchanges has been successful in reproducing the experimental data. During the RHIC experiment in year 2015, RHIC delivered polarized proton collisions with Au and Al nuclei for the first time, enabling the exploration of the mechanism of transverse single-spin asymmetries with nuclear collisions. The observed asymmetries showed surprisingly strong A-dependence in the inclusive forward neutron production, while the existing framework which was successfull in p+p only predicts moderate A- dependence. Thus the observed data are absolutely unexpected and unpredicted. In this report, experimental and theoretical efforts are discussed to disentangle the observed A-dependence using somewhat semi-inclusive type measurements and Monte-Carlo study, respectively.

  10. SPIN-selling

    CERN Document Server

    Rackham, Neil

    1995-01-01

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

  11. Investigation of HNCO isomer formation in ice mantles by UV and thermal processing: An experimental approach

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez-Escobar, A.; Giuliano, B. M.; Caro, G. M. Muñoz; Cernicharo, J. [Centro de Astrobiología, INTA-CSIC, Carretera de Ajalvir, km 4, Torrejón de Ardoz, E-28850 Madrid (Spain); Marcelino, N., E-mail: bgiuliano@cab.inta-csic.es [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States)

    2014-06-10

    Current gas-phase models do not account for the abundances of HNCO isomers detected in various environments, suggesting their formation in icy grain mantles. We attempted to study a formation channel of HNCO and its possible isomers by vacuum-UV photoprocessing of interstellar ice analogs containing H{sub 2}O, NH{sub 3}, CO, HCN, CH{sub 3}OH, CH{sub 4}, and N{sub 2} followed by warm-up under astrophysically relevant conditions. Only the H{sub 2}O:NH{sub 3}:CO and H{sub 2}O:HCN ice mixtures led to the production of HNCO species. The possible isomerization of HNCO to its higher energy tautomers following irradiation or due to ice warm-up has been scrutinized. The photochemistry and thermal chemistry of H{sub 2}O:NH{sub 3}:CO and H{sub 2}O:HCN ices were simulated using the Interstellar Astrochemistry Chamber, a state-of-the-art ultra-high-vacuum setup. The ice was monitored in situ by Fourier transform mid-infrared spectroscopy in transmittance. A quadrupole mass spectrometer detected the desorption of the molecules in the gas phase. UV photoprocessing of H{sub 2}O:NH{sub 3}:CO and H{sub 2}O:HCN ices lead to the formation of OCN{sup –} as a main product in the solid state and a minor amount of HNCO. The second isomer HOCN has been tentatively identified. Despite its low efficiency, the formation of HNCO and the HOCN isomers by UV photoprocessing of realistic simulated ice mantles might explain the observed abundances of these species in photodissociation regions, hot cores, and dark clouds.

  12. Identification of the naturally occurring isomer of zearalenol produced by Fusarium roseum 'Gibbosum' in rice culture.

    Science.gov (United States)

    Hagler, W M; Mirocha, C J; Pathre, S V; Behrens, J C

    1979-01-01

    One diastereomer of trans-zearalenol [2,4-dihydroxy-6-(6,10-dihydroxy-trans-1-undecenyl)-benzoic acid-mu-lactone] was isolated from cultures of Fusarium roseum 'Gibbosum.' This strongly estrogenic metabolite was identified by analysis of its mass spectrum and its behavior in thin-layer, high-pressure liquid and gas-liquid chromatographic systems. The concentration of zearalenol in cultures was 563 mu g/g, or 7% of the 8,000-mu g/g zearalenone content, while the two diastereomers of 8'-hydroxyzearalenone each occurred at 3% of the zearalenone level. Of the two possible diastereomers of zearalenol, the one occurring in cultures was identical to the low-melting-point (171 degrees C) isomer (alpha) obtained by synthesis. In the rat uterus bioassay, the alpha zearalenol isomer was three times more estrogenic than zearalenone while the beta isomer was equal in activity in zearalenone. The two diastereomers of zearalenol can be distinguished from each other by the intensity of the m/e+ 302 fragment of the mass spectrum of the pure underivatized compound. PMID:485136

  13. Direct Observation of High-Spin States in Manganese Dimer and Trimer Cations by X-ray Magnetic Circular Dichroism Spectroscopy in an Ion Trap

    CERN Document Server

    Zamudio-Bayer, Vicente; Langenberg, Andreas; Kossick, Martin; Ławicki, Arkadiusz; Terasaki, Akira; von Issendorff, Bernd; Lau, J Tobias

    2015-01-01

    The electronic structure and magnetic moments of free Mn$_2^+$ and Mn$_3^+$ are characterized by $2p$ x-ray absorption and x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap that is coupled to a synchrotron radiation beamline. Our results show directly that localized magnetic moments of 5 $\\mu_B$ are created by $3d^5 (^6\\mathrm{S})$ states at each ionic core, which are coupled in parallel to form molecular high-spin states via indirect exchange that is mediated in both cases by a delocalized valence electron in a singly-occupied $4s$ derived orbital with an unpaired spin. This leads to total magnetic moments of 11 $\\mu_B$ for Mn$_2^+$ and 16 $\\mu_B$ for Mn$_3^+$, with no contribution of orbital angular momentum.

  14. Presence or absence of order by disorder in a highly frustrated region of the spin-1/2 Ising-Heisenberg model on triangulated Husimi lattices.

    Science.gov (United States)

    Strečka, Jozef; Ekiz, Cesur

    2015-05-01

    The geometrically frustrated spin-1/2 Ising-Heisenberg model on triangulated Husimi lattices is exactly solved by combining the generalized star-triangle transformation with the method of exact recursion relations. The ground-state and finite-temperature phase diagrams are rigorously calculated along with both sublattice magnetizations of the Ising and Heisenberg spins. It is evidenced that the Ising-Heisenberg model on triangulated Husimi lattices with two or three interconnected triangles-in-triangles units displays in a highly frustrated region a quantum disorder irrespective of temperature, whereas the same model on triangulated Husimi lattices with a greater connectivity of triangles-in-triangles units exhibits at low enough temperatures an outstanding quantum order due to the order-by-disorder mechanism. The quantum reduction of both sublattice magnetizations in the peculiar quantum ordered state gradually diminishes upon increasing the coordination number of the underlying Husimi lattice.

  15. Study of octupole-deformed K=1/2 bands in sup 2 sup 2 sup 7 Th High spin states

    CERN Document Server

    Hammond, N

    2002-01-01

    High spin states in sup 2 sup 2 sup 7 Th have been populated using the reaction sup 2 sup 2 sup 6 Ra(alpha,3n) sup 2 sup 2 sup 7 Th at a bombarding energy of 33 MeV. The high-spin rotational structures of this nucleus have been refined and extended. In addition, the linking of these structures with the low-spin states known from sup 2 sup 3 sup 1 U alpha decay has allowed a comprehensive decay scheme of this nucleus to be assembled for the first time. Four previously known rotational bands are interpreted as Coriolis-coupled K suppi = 1/2 sup + and K suppi = 1/2 sup - bands, in agreement with predictions using a reflection-asymmetric mean-field approach. The determination of decoupling parameters for these bands is consistent with the a(K suppi = 1/2 sup +) = -a(K suppi = 1/2 sup -) rigid-octupole-rotor expectation. A further rotational band is interpreted as having K suppi = 3/ sup - . Measured D sub 0 /Q sub 0 ratios are consistent with an interpolation, of the values given for neighbouring even-even nuclei...

  16. Evolution of nuclear structure in neutron-rich odd-Zn isotopes and isomers

    Directory of Open Access Journals (Sweden)

    C. Wraith

    2017-08-01

    Full Text Available Collinear laser spectroscopy was performed on Zn (Z=30 isotopes at ISOLDE, CERN. The study of hyperfine spectra of nuclei across the Zn isotopic chain, N=33–49, allowed the measurement of nuclear spins for the ground and isomeric states in odd-A neutron-rich nuclei up to N=50. Exactly one long-lived (>10 ms isomeric state has been established in each 69–79Zn isotope. The nuclear magnetic dipole moments and spectroscopic quadrupole moments are well reproduced by large-scale shell–model calculations in the f5pg9 and fpg9d5 model spaces, thus establishing the dominant term in their wave function. The magnetic moment of the intruder Iπ=1/2+ isomer in 79Zn is reproduced only if the νs1/2 orbital is added to the valence space, as realized in the recently developed PFSDG-U interaction. The spin and moments of the low-lying isomeric state in 73Zn suggest a strong onset of deformation at N=43, while the progression towards 79Zn points to the stability of the Z=28 and N=50 shell gaps, supporting the magicity of 78Ni.

  17. Non magnetic neutron spin quantum precession using multilayer spin splitter and a phase-spin echo interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Ebisawa, T.; Tasaki, S.; Kawai, T.; Akiyoshi, T. [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.; Achiwa, N.; Hino, M.; Otake, Y.; Funahashi, H.

    1996-08-01

    The authors have developed cold neutron optics and interferometry using multilayer mirrors. The advantages of the multilayer mirrors are their applicability to long wavelength neutrons and a great variety of the mirror performance. The idea of the present spin interferometry is based on nonmagnetic neutron spin quantum precession using multilayer spin splitters. The equation for polarized neutrons means that the polarized neutrons are equivalent to the coherent superposition of two parallel spin eigenstates. The structure and principle of a multilayer spin splitter are explained, and the nonmagnetic gap layer of the multilayer spin splitter gives rise to neutron spin quantum precession. The performance test of the multilayer spin splitter were made with a new spin interferometer, which is analogous optically to a spin echo system with vertical precession field. The spin interferometers were installed at Kyoto University research reactor and the JRR-3. The testing method and the results are reported. The performance tests on a new phase-spin echo interferometer are described, and its applications to the development of a high resolution spin echo system and a Jamin type cold neutron interferometer are proposed. (K.I.)

  18. Theoretical Study of the Diastereofacial Isomers of Aldrin and Dieldrin

    Directory of Open Access Journals (Sweden)

    Zoran Zdravkovski

    2006-02-01

    Full Text Available The Diels-Alder reaction of hexachlorocyclopentadiene with norbornadiene givesaldrin but theoretically three other diastereofacial isomers are possible. On oxidation theseisomers can generate eight adducts one of which is known as dieldrin. All these, as well asthe corresponding reactions with hexafluorocyclopenadiene were studied by semiempirical(AM1 and PM3 and hybrid density functional (B3LYP methods. Besides the energy levels,the transition states were calculated for the reactions leading to the diastereofacial isomers ofaldrin, which indicate that aldrin is the favored product of the reaction both fromthermodynamic and kinetic point of view.

  19. Static and dynamic first hyperpolarizabilities of azo-enaminone isomers

    Science.gov (United States)

    Fonseca, T. L.; Castro, M. A.; de Oliveira, H. C. B.; Cunha, S.

    2007-07-01

    The linear polarizabilities and first hyperpolarizabilities of two geometrical isomers ( Z, E) of donor-acceptor azo-enaminones have been calculated, taking into account frequency dispersion effects, through CPHF method. Static results were also obtained at the MP2 level and correlated dynamic values were estimated using the multiplicative correction scheme. Our results show that the diagonal component of the first hypepolarizability of E isomers is enhanced with increasing donor strength. Dispersion effects have a marked influence for the standard frequencies considered here ( ω = 0.0239 and 0.0428 a.u), specially for second harmonic generation.

  20. Transverse dipole spin modes in quantum dots

    Science.gov (United States)

    Lipparini, E.; Barranco, M.; Emperador, A.; Pi, M.; Serra, Ll.

    1999-09-01

    We have carried out a systematic analysis of the transverse dipole spin response of a large-size quantum dot within time-dependent current density functional theory. Results for magnetic fields corresponding to integer filling factors are reported, as well as a comparison with the longitudinal dipole spin response. As in the two-dimensional electron gas, the spin response at high-spin magnetization is dominated by a low-energy transverse mode.

  1. Isomers in 128Pd and 126Pd: evidence for a robust shell closure at the neutron magic number 82 in exotic palladium isotopes.

    Science.gov (United States)

    Watanabe, H; Lorusso, G; Nishimura, S; Xu, Z Y; Sumikama, T; Söderström, P-A; Doornenbal, P; Browne, F; Gey, G; Jung, H S; Taprogge, J; Vajta, Zs; Wu, J; Yagi, A; Baba, H; Benzoni, G; Chae, K Y; Crespi, F C L; Fukuda, N; Gernhäuser, R; Inabe, N; Isobe, T; Jungclaus, A; Kameda, D; Kim, G D; Kim, Y K; Kojouharov, I; Kondev, F G; Kubo, T; Kurz, N; Kwon, Y K; Lane, G J; Li, Z; Moon, C-B; Montaner-Pizá, A; Moschner, K; Naqvi, F; Niikura, M; Nishibata, H; Nishimura, D; Odahara, A; Orlandi, R; Patel, Z; Podolyák, Zs; Sakurai, H; Schaffner, H; Simpson, G S; Steiger, K; Suzuki, H; Takeda, H; Wendt, A; Yoshinaga, K

    2013-10-11

    The level structures of the very neutron-rich nuclei 128Pd and 126Pd have been investigated for the first time. In the r-process waiting-point nucleus 128Pd, a new isomer with a half-life of 5.8(8) μs is proposed to have a spin and parity of 8(+) and is associated with a maximally aligned configuration arising from the g(9/2) proton subshell with seniority υ=2. For 126Pd, two new isomers have been identified with half-lives of 0.33(4) and 0.44(3) μs. The yrast 2(+) energy is much higher in 128Pd than in 126Pd, while the level sequence below the 8(+) isomer in 128Pd is similar to that in the N=82 isotone 130Cd. The electric quadrupole transition that depopulates the 8(+) isomer in 128Pd is more hindered than the corresponding transition in 130Cd, as expected in the seniority scheme for a semimagic, spherical nucleus. These experimental findings indicate that the shell closure at the neutron number N=82 is fairly robust in the neutron-rich Pd isotopes.

  2. spin coating

    African Journals Online (AJOL)

    PROJET SOJA

    Intense UV photoluminescence is observed for intrinsic ZnO film. Keywords : thin films, oxidize zinc doped aluminium (ZnO:Al), sol-gel, spin coating, structural analysis, electric and optical properties. 1. Introduction. Depuis ces vingt dernières années les couches minces d'oxyde de zinc ont connu un intérêt croissant dans ...

  3. Efficient thermal spin injection in metallic nanostructures

    Science.gov (United States)

    Nomura, Tatsuya; Ariki, Taisei; Hu, Shaojie; Kimura, Takashi

    2017-11-01

    Thermal spin injection is a unique and fascinating method for generating spin current. If magnetization can be controlled by thermal spin injection, various advantages will be provided in spintronic devices, through its wireless controllability. However, the generation efficiency of thermal spin injection is believed to be lower than that of electrical spin injection. Here, we explore a suitable ferromagnetic metal for an efficient thermal spin injection, via systematic experiments based on diffusive spin transport under temperature gradients. Since a ferromagnetic metal with strong spin splitting is expected to have a large spin-dependent Seebeck coefficient, a lateral spin valve based on CoFe electrodes has been fabricated. However, the superior thermal spin injection property has not been observed, because the CoFe electrode retained its crystalline signature—where s-like electrons dominate the transport property in the ferromagnet. To suppress the crystalline signature, we adopt a CoFeAl electrode, in which the Al impurity significantly reduces the contribution from s-like electrons. Highly efficient thermal spin injection has been demonstrated using this CoFeAl electrode. Further optimization for thermal spin injection has been demonstrated by adjusting the Co and Fe composition.

  4. Effect of rice-straw biochar on selective biodegradation of nonylphenols in isomer specificity.

    Science.gov (United States)

    Yao, Lingdan; Wang, Lixiao; Cheng, Guanghuan; Huang, Qian; Hu, Baolan; Lu, Jingrang; Lou, Liping

    2017-09-01

    In a previous study, we found that rice-straw biochar degraded and removed hydrophobic organic contaminants (HOCs) through coupled adsorption-biodegradation. However, few studies have determined whether biochar affects HOC isomer degradation and isomer-selective biodegradation or whether biochar can alter HOC isomer features, resulting in changes to HOC isomer residues in water environments. In this study, the effects of biochar at two dosages (0.001 and 0.01 g) on the biodegradation of ten isomers of a typical xenoestrogen of nonylphenol (NP) were evaluated. The results revealed that there were no effects of biochar on the adsorption of NP isomers. However, biochar addition affected the biodegradation of a specific isomer without altering the features of the NP isomers. The treatment of NP isomers with Pseudoxanthomonas sp. yielded degradation ratios ranging from 60.7 to 100%. At 0.001 g biochar treatment, the degradation of eight NP isomers was enhanced (except for NP194 and NP193a+b) due to their bulky structures. The degradation of the ten NP isomers was inhibited when 0.01 g biochar was added. These findings characterized the effects of biochar on NP isomer contaminants and provided basic information for the application of biochar for the remediation of NP isomer contaminants.

  5. Cis-9, trans-11 and trans-10, cis-12 conjugated linoleic acid isomers do not modify body composition in adult sedentary or exercised rats.

    Science.gov (United States)

    Mirand, Philippe Patureau; Arnal-Bagnard, Marie-Agnès; Mosoni, Laurent; Faulconnier, Yannick; Chardigny, Jean-Michel; Chilliard, Yves

    2004-09-01

    Dietary CLA isomers were shown to reduce adipose tissues in growing animals, mainly in mice, but their effects in adult animals remain unclear. This study was conducted to determine whether these effects depend on the isomer fed, on physical activity, or on the initial level of body fat. Male Wistar rats (4 mo old) were fed for 6 wk diets containing either no CLA, the cis-9, trans-11 CLA isomer (10 g/kg), the trans-10, cis-12 CLA isomer (10 g/kg), or both isomers (10 g/kg each). Half of the rats were assigned to exercise by treadmill running (1 h/d, 22 m/min). The initial body fat level was normal (12.7%) in a first trial, and high (18.9%) in a second trial. Chemical and anatomical body compositions were determined by chemical analysis and organ dissection. In both trials, the CLA diets, whatever the isomer, had no effect on food intake and body weight changes, on body chemical composition (fat, protein and water contents or gains), or on the body anatomical composition (weights or gains in epididymal and perirenal adipose tissues, in liver and in 4 muscles). There was no interaction between CLA treatment and physical activity. In conclusion, adult male rats do not appear to be responsive to the fat-to-lean partitioning effect of CLA described in growing rats. This was not affected by exercise or initial body fat level.

  6. Geometric spin echo under zero field

    Science.gov (United States)

    Sekiguchi, Yuhei; Komura, Yusuke; Mishima, Shota; Tanaka, Touta; Niikura, Naeko; Kosaka, Hideo

    2016-05-01

    Spin echo is a fundamental tool for quantum registers and biomedical imaging. It is believed that a strong magnetic field is needed for the spin echo to provide long memory and high resolution, since a degenerate spin cannot be controlled or addressed under a zero magnetic field. While a degenerate spin is never subject to dynamic control, it is still subject to geometric control. Here we show the spin echo of a degenerate spin subsystem, which is geometrically controlled via a mediating state split by the crystal field, in a nitrogen vacancy centre in diamond. The demonstration reveals that the degenerate spin is protected by inherent symmetry breaking called zero-field splitting. The geometric spin echo under zero field provides an ideal way to maintain the coherence without any dynamics, thus opening the way to pseudo-static quantum random access memory and non-invasive biosensors.

  7. Super-spinning compact objects and models of high-frequency quasi-periodic oscillations observed in Galactic microquasars. II. Forced resonances

    Science.gov (United States)

    Kotrlová, A.; Šrámková, E.; Török, G.; Stuchlík, Z.; Goluchová, K.

    2017-11-01

    In our previous work (Paper I) we applied several models of high-frequency quasi-periodic oscillations (HF QPOs) to estimate the spin of the central compact object in three Galactic microquasars assuming the possibility that the central compact body is a super-spinning object (or a naked singularity) with external spacetime described by Kerr geometry with a dimensionless spin parameter a ≡ cJ/GM2 > 1. Here we extend our consideration, and in a consistent way investigate implications of a set of ten resonance models so far discussed only in the context of a five of these models that involve Keplerian and radial epicyclic oscillations we find the existence of a unique specific QPO excitation radius. Consequently, there is a simple behaviour of dimensionless frequency M × νU(a) represented by a single continuous function having solely one maximum close to a ≳ 1. Only one of these models is compatible with the expectation of a ≳ 1. The other five models that involve the radial and vertical epicyclic oscillations imply the existence of multiple resonant radii. This signifies a more complicated behaviour of M × νU(a) that cannot be represented by single functions. Each of these five models is compatible with the expectation of a ≳ 1.

  8. High-spin transition quadrupole moments in neutron-rich Mo and Ru nuclei: Testing γ softness?

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, J.B. [Physics Department, Washington University, St. Louis, MO 63130 (United States); Reviol, W., E-mail: reviol@wustl.edu [Chemistry Department, Washington University, St. Louis, MO 63130 (United States); Sarantites, D.G. [Chemistry Department, Washington University, St. Louis, MO 63130 (United States); Afanasjev, A.V. [Department of Physics and Astronomy, Mississippi State University, Starkville, MS 39762 (United States); Janssens, R.V.F. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Abusara, H. [Department of Physics, Faculty of Science, An-Najah National University, Nablus, Palestine (Country Unknown); Carpenter, M.P. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Chen, X. [Chemistry Department, Washington University, St. Louis, MO 63130 (United States); Chiara, C.J. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742 (United States); Greene, J.P.; Lauritsen, T. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); McCutchan, E.A. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973 (United States); Seweryniak, D.; Zhu, S. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2013-06-10

    The transition quadrupole moments, Q{sub t}, of rotational bands in the neutron-rich, even-mass {sup 102–108}Mo and {sup 108–112}Ru nuclei were measured in the 8–16 ℏ spin range with the Doppler-shift attenuation method. The nuclei were populated as fission fragments from {sup 252}Cf fission. The detector setup consisted of the Gammasphere spectrometer and the HERCULES fast-plastic array. At moderate spin, the Q{sub t} moments are found to be reduced with respect to the values near the ground states. Attempts to describe the observations in mean-field-based models, specifically cranked relativistic Hartree–Bogoliubov theory, illustrate the challenge theory faces and the difficulty to infer information on γ softness and triaxiality from the data.

  9. Black Hole Spin Measurement Uncertainty

    Science.gov (United States)

    Salvesen, Greg; Begelman, Mitchell C.

    2018-01-01

    Angular momentum, or spin, is one of only two fundamental properties of astrophysical black holes, and measuring its value has numerous applications. For instance, obtaining reliable spin measurements could constrain the growth history of supermassive black holes and reveal whether relativistic jets are powered by tapping into the black hole spin reservoir. The two well-established techniques for measuring black hole spin can both be applied to X-ray binaries, but are in disagreement for cases of non-maximal spin. This discrepancy must be resolved if either technique is to be deemed robust. We show that the technique based on disc continuum fitting is sensitive to uncertainties regarding the disc atmosphere, which are observationally unconstrained. By incorporating reasonable uncertainties into black hole spin probability density functions, we demonstrate that the spin measured by disc continuum fitting can become highly uncertain. Future work toward understanding how the observed disc continuum is altered by atmospheric physics, particularly magnetic fields, will further strengthen black hole spin measurement techniques.

  10. Flexible metal–organic supramolecular isomers for gas separation

    Energy Technology Data Exchange (ETDEWEB)

    Motkuri, Radha K.; Tian, Jian; Thallapally, Praveen K.; Fernandez, Carlos A.; Dalgarno, Scott J.; Warren, John E.; McGrail, B. Peter; Atwood, Jerry L.

    2010-01-01

    Here in we report three porous metal-organic supramolecular isomers (PtS, Diamondoid and Lonsdaleite networks) generated from a single building block (tetrakis[4-(carboxyphenyl)oxamethyl]methane, 1), with the differences in solid-state packing, amount of gas uptake and selectivity towards other gases and so on

  11. A study of the origin of chloramphenicol isomers in honey

    NARCIS (Netherlands)

    Yanovych, Dmytro; Berendsen, Bjorn; Zasadna, Zvenyslava; Rydchuk, Mariana; Czymai, Tobias

    2017-01-01

    Due to the unexpected detection of chloramphenicol isomer residues in honey, we have studied the hypothesis of unauthorized or unintended use of unregistered veterinary drug preparations. First, we have investigated honey samples in which a discrepancy was observed between the results of the

  12. Shape Isomer in 236U Populated by Thermal Neutron Capture

    DEFF Research Database (Denmark)

    Andersen, Verner; Christensen, Carl Jørgen; Borggreen, J.

    1976-01-01

    The 116 ns shape isomer in 236U was populated by thermal neutron capture. Conversion electrons and X-rays were detected simultaneously in delayed coincidence with fission. The ratio of delayed to prompt fission was measured with the result, σIIf/σf = (1.0±0.2) × 10−5. A branching of the isomeric...

  13. Spin currents, spin torques, and the concept of spin superfluidity

    Science.gov (United States)

    Rückriegel, Andreas; Kopietz, Peter

    2017-03-01

    In magnets with noncollinear spin configuration the expectation value of the conventionally defined spin current operator contains a contribution which renormalizes an external magnetic field and hence affects only the precessional motion of the spin polarization. This term, which has been named angular spin current by Sun and Xie [Phys. Rev. B 72, 245305 (2005)], 10.1103/PhysRevB.72.245305, does not describe the translational motion of magnetic moments. We give a prescription for how to separate these two types of spin transport and show that the translational movement of the spin is always polarized along the direction of the local magnetization. We also show that at vanishing temperature the classical magnetic order parameter in magnetic insulators cannot carry a translational spin current and elucidate how this affects the interpretation of spin supercurrents.

  14. Spin-torque switching of a nano-magnet using giant spin hall effect

    Directory of Open Access Journals (Sweden)

    Ashish V. Penumatcha

    2015-10-01

    Full Text Available The Giant Spin Hall Effect(GSHE in metals with high spin-orbit coupling is an efficient way to convert charge currents to spin currents, making it well-suited for writing information into magnets in non-volatile magnetic memory as well as spin-logic devices. We demonstrate the switching of an in-plane CoFeB magnet using a combination of GSHE and an external magnetic field. The magnetic field dependence of the critical current is used to estimate the spin hall angle with the help of a thermal activation model for spin-transfer torque switching of a nanomagnet.

  15. A study of spin isomer conversion kinetics in supercritical fluid hydrogen for cyrogenic fuel storage technologies

    Science.gov (United States)

    Matthews, Manyalibo J.; Petitpas, Guillaume; Aceves, Salvador M.

    2011-08-01

    A detailed kinetic study of para-ortho hydrogen conversion under supercritical conditions using rotational Raman scattering is presented. Isochoric measurements of initially low ortho concentrations over temperatures 32 hydrogen fuel tank dormancy performance for hydrogen-power vehicles.

  16. spin coating

    African Journals Online (AJOL)

    PROJET SOJA

    Dans ce travail nous avons préparé des couches minces de l'oxyde de zinc ZnO dopées à l'aluminium et non dopées par la technique Sol-Gel associée au « spin coating » sur des substrats en verre « pyrex » à partir de l'acétate de zinc dissous dans une solution de l'éthanol. Nous avons ensuite effectué des analyses ...

  17. Effects on thyroid hormone and retinoid metabolism in transthyretin-null mice by polychlorinated biphenyl isomers 118 and 114

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, N.; Yonemoto, J.; Takeuchi, Y.; Yokoi, C.; Tohyama, C. [National Inst. for Environmental Studies, Tsukuba (Japan)

    2004-09-15

    Some congeners/isomers of polychlorinated biphenyls (PCBs) and their metabolites are known to disturb thyroid and retinoid metabolism in laboratory animals and humans. Among 209 isomers of PCBs, 12 PCB isomers termed as the coplanar PCBs are grouped into dioxin-like chemicals based on their resemblance of toxic effects and mechanism(s) to dioxins. Mechanism(s) of toxicity by the dioxin-like chemicals have been established to be mediated through aryl hydrocarbon receptor (AhR). The toxic potency of each congener/isomer of dioxin-like chemicals has been evaluated by relative potency to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as the toxic equivalent factor (TEF). Because dioxins in environments are generally distributed as mixtures, the toxic equivalency (TEQ) concept has been adopted to evaluate the health risk of exposure to complex environmental mixtures. TEQ values are calculated by multiplication of the sum of the chemical concentrations by the corresponding TEF values. The present study was undertaken to investigate the effects of two coplanar PCBs, PCB118, highly detected in human tissues and milk (TEF value: 0.0001), and PCB114 (TEF value: 0.0005) on thyroid hormone and retinoid metabolism. Possible involvement of transthyretin (TTR), the principal carrier of thyroid hormone and retinol-binding protein in the rodent, in PCBs-induced disruption of thyroid and retinoid homeostasis was investigated.

  18. A QSAR for the Mutagenic Potencies of Twelve 2-Amino-trimethylimidazopyridine Isomers: Structural, Quantum Chemical,and Hydropathic Factors

    Energy Technology Data Exchange (ETDEWEB)

    Knize, M G; Hatch, F T; Tanga, M J; Lau, E V; Colvin, M E

    2005-04-23

    An isomeric series of heterocyclic amines related to one found in heated muscle meats was investigated for properties that predict their measured mutagenic potency. Eleven of the 12 possible 2-amino-trimethylimidazopyridine (TMIP) isomers were tested for mutagenic potency in the Ames/Salmonella test with bacterial strain TA98, and resulted in a 600-fold range in potency. Structural, quantum chemical and hydropathic data were calculated on the parent molecules and the corresponding nitrenium ions of all of the tested isomers to establish models for predicting the potency of the unknown isomer. The regression model accounting for the largest fraction of the total variance in mutagenic potency contains four predictor variables: dipole moment, a measure of the gap between amine LUMO and HOMO energies, percent hydrophilic surface, and energy of amine LUMO. The most important determinants of high mutagenic potency in these amines are: (1) a small dipole moment, (2) the combination of b-face ring fusion and N3-methyl group, and (3) a lower calculated energy of the {pi} electron system. Based on predicted potency from the average of five models, the isomer not yet synthesized and tested is expected to have a mutagenic potency of 0.84 revertants/{micro}g in test strain TA98.

  19. Regiospecific Distribution of trans-Octadecenoic Acid Positional Isomers in Triacylglycerols of Partially Hydrogenated Vegetable Oil and Ruminant Fat.

    Science.gov (United States)

    Yoshinaga, Kazuaki; Kawamura, Yoshinori; Kitayama, Takashi; Nagai, Toshiharu; Mizobe, Hoyo; Kojima, Koichi; Watanabe, Yomi; Sato, Shinichi; Beppu, Fumiaki; Gotoh, Naohiro

    2015-01-01

    It is revealed that binding position of fatty acid in triacylglycerol (TAG) deeply relates to the expression of its function. Therefore, we investigated the binding positions of individual trans-octadecenoic acid (trans-C18:1) positional isomers, known as unhealthy fatty acids, on TAG in partially hydrogenated canola oil (PHCO), milk fat (MF), and beef tallow (BT). The analysis was carried out by the sn-1(3)-selective transesterification of Candida antarctica Lipase B and by using a highly polar ionic liquid capillary column for gas chromatography-flame ionization detection. Trans-9-C18:1, the major trans-C18:1 positional isomer, was selectively located at the sn-2 position of TAG in PHCO, although considerable amounts of trans-9-C18:1 were also esterified at the sn-1(3) position. Meanwhile, trans-11-C18:1, the major isomer in MF and BT, was preferentially located at the sn-1(3) position. These results revealed that the binding position of trans-C18:1 positional isomer varies between various fats and oils.

  20. Polar-Core Spin Vortex of Quasi-2D Spin-2 Condensate in a Flat-Bottomed Optical Trap

    Science.gov (United States)

    Zheng, Gong-Ping; Chang, Gao-Zhan; Li, Pin; Li, Ting

    2017-10-01

    Motivated by the recent experiments realized in a flat-bottomed optical trap [Science 347 (2015) 167; Nat. Commun. 6 (2015) 6162], we study the ground state of polar-core spin vortex of quasi-2D spin-2 condensate in a homogeneous trap plus a weak magnetic field. The exact spatial distribution of local spin is obtained and the vortex core are observed to decrease with the growth of the effective spin-spin interaction. For the larger effective spin-spin interaction, the spatial distribution of spin magnitude in spin-2 condensate we obtained agrees well with that of spin-1 condensate in a homogeneous trap, where a polar-core spin vortex was schematically demonstrated as a fully-magnetized planar spin texture with a zero-spin core. The effective spin-spin interaction is proportional to both the bare spin-spin interaction and the radius of the homogeneous trap, simultaneously. Thus the polar-core spin vortex we obtained can be easily controlled by the radius of the trap. Supported by the National Natural Science Foundation of China under Grant No. 11274095, the Key Scientific Research Project of Henan Province of China under Grant No. 16A140011, and the High Performance Computing Center of Henan Normal University

  1. Mutagenic activity of surface soil and quantification of 1,3-, 1,6-, and 1,8-dinitropyrene isomers in soil in Japan.

    Science.gov (United States)

    Watanabe, T; Goto, S; Matsumoto, Y; Asanoma, M; Hirayama, T; Sera, N; Takahashi, Y; Endo, O; Sakai, S; Wakabayashi, K

    2000-04-01

    To clarify the mutagenic potential of nonagricultural surface soil in Japan, 110 soil samples were collected from five geographically different areas between November 1996 and March 1997, and organic extracts of the soil samples were examined by the Ames/Salmonella assay. Most of the soil extracts showed mutagenicity toward both strains TA98 and TA100 in the presence and/or absence of a mammalian metabolic activation system (S9 mix), suggesting that surface soil is largely contaminated with environmental mutagens. Soil samples collected at Hekinan, Kobe, and Osaka were highly mutagenic toward both strains, and their potencies toward TA98 without S9 mix were extremely high, inducing more than 12 000 revertants per gram of soil. On the other hand, soil samples from Muroran showed strong mutagenicity toward TA100 with S9 mix. Furthermore, 1, 3-dinitropyrene (DNP), 1,6-DNP, and 1,8-DNP in soil samples collected at 10 sampling sites in three metropolitan areas were quantified by fluorometric detection of the corresponding diaminopyrene isomers using high-performance liquid chromatography (HPLC). Three DNP isomers were detected in all soil samples, and the amounts of 1,3-, 1,6-, and 1,8-DNP isomers in the soil samples were 12-3270, 14-5587, and 13-6809 pg/g, respectively. The gross amount of three DNP isomers in surface soil collected at Hekinan was more than 10 ng per gram of soil. The highest contribution ratios of DNP isomers to the mutagenicity of soil extracts were observed for the samples collected at Osaka, and the total of the contribution ratios of three DNP isomers was about 50%. These results suggest that surface soil is largely contaminated with mutagenic compounds and that DNP isomers are one class of major mutagenic and carcinogenic compounds contaminating surface soil.

  2. Morphology-insensitive Performance Facilitates Transition from Spin-Coating to Roll-to-Roll Coating For High-Performance, Solution-Processed Solar Cells

    Science.gov (United States)

    Delongchamp, Dean

    Solution processing via roll-to-roll (R2R) coating promises a low cost, low thermal-budget, sustainable revolution for the production of solar cells. Yet virtually all high efficiency solution processed research cells have been demonstrated by spin-coating, a low-volume deposition process. We present detailed device and morphology studies of an organic photovoltaic (OPV) system deposited by a high volume manufacturing technique, blade-coating, that achieves greater than 9.5 % power conversion efficiency (PCE). The average crystal domain orientation and characteristic phase separation length distribution are markedly different when deposited by blade-coating rather than spin-coating,. This result allows us to determine which aspects of morphology are not relevant to the PCE of this system. Whether the crystallites are ``face on'' or ``edge on'' does not appear to impact the PCE of system, nor does the length scale or ``hierarchical'' nature of the phase length scale. Persistent morphological qualities that may be associated with high PCE in this system are relatively pure phases and relatively strong diffraction. We posit that OPV systems in which the PCE is less sensitive to morphology may also be less sensitive to film thickness, enabling some to maintain high PCE in active layers thicker than greater than ~200 nm. We confirm that blade-coating is a suitable prototyping technique for R2R coating by demonstrating nominally identical morphologies for both piece blade-coating and continuous-web, slot-die coating.

  3. Spin glass behavior in a highly oxygen deficient Perovskite BaBiO.28Co0.72O2.2

    Energy Technology Data Exchange (ETDEWEB)

    Klimczuk, Thomasz W [Los Alamos National Laboratory; Zandbergen, H [DELFT UNIV.; Huang, Q [NIST CENTER FOR NEUTRON; Mcqueen, T [PRINCETON U.

    2008-01-01

    A highly oxygen deficient perovskite, BaBio.28Coo.n02.2, was synthesized by solid state reaction. The crystal structure was determined by neutron and x-ray powder diffraction. The material exhlbits semiconducting behavior with an energy gap of 1.8 eV. Magnetic susceptibility studies reveal spin-glass ordering, which may have its origin in the frustration caused by the presence of competing antiferromagnetic and ferromagnetic interactions. The electron diffraction study shows the existence of short range ordering in thls phase.

  4. A Measurement of Spin Asymmetries in Quasi-Real Photo-Production of Hadrons with High Transverse Momentum at COMPASS

    CERN Document Server

    Kuhn, Roland

    2007-01-01

    During 2002–2004, the COMPASS experiment at the CERN SPS has recorded 1.5 fb−1 of deep inelastic scattering events with polarized muon beam and polarized deuterium target. The cross section for singleinclusive charged hadron production in dependence on the hadron’s transverse momentum pT is extracted. A PYTHIA and GEANT simulation is used to obtain the acceptance correction factors. The double spin asymmetry $A^{hd}_{LL}$ is measured in the region 1 GeV/c < pT < 3:5 GeV/c, the pT dependence of which is connected to the gluon polarization $\\DeltaG$.

  5. Impact of the spin state switching on the dielectric constant of iron (II) spin crossover nanoparticles

    OpenAIRE

    Iazzolino, Antonio; Galle, Geoffrey; Degert, Jérôme; Létard, Jean François; Freysz, Eric

    2015-01-01

    International audience; A simple model makes it possible to relate the dielectric constant of spin-crossover nanoparticles to the indices of refraction and the absorption coefficients of solutions containing such nanoparticles. Using this model we show that in the visible spectral range, the switching from a diamagnetic (low spin state) to a paramagnetic (high spin state) state results in a noticeable change of the dielectric constants of the spin crossover nanoparticles containing 3, 5 and 7...

  6. Proton radioactivity: The case for {sup 53m}Co proton-emitter isomer

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, O.A.P.; Medeiros, E.L. [Centro Brasileiro de Pesquisas Fisicas - CBPF/MCT, Rio de Janeiro-RJ (Brazil)

    2010-07-15

    The partial proton emission half-life for {sup 53m}Co unstable isomer is re-examined in the framework of a semiempirical model based on tunneling through a Coulomb-plus-centrifugal-plus-overlapping potential barrier within the spherical nucleus approximation. It is shown that the known measured half-life value of 17s is compatible with a large prolate shape for {sup 53m}Co proton emitter and a high angular momentum l=11 assigned to the proton transition to the ground state of {sup 52}Fe. (orig.)

  7. Proton radioactivity: the case for {sup 53m} Co proton-emitter isomer

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, O.A.P.; Medeiros, E.L., E-mail: emil@cbpf.b

    2010-07-01

    The partial proton emission half-life for {sup 53m}Co unstable isomer is re-examined in the framework of a semiempirical model based on tunneling through a Coulomb-plus centrifugal- plus-overlapping potential barrier within the spherical nucleus approximation. It is shown that the known measured half-life value of 17 s is compatible with a large prolate shape for {sup 53m}Co proton emitter and a high angular momentum {iota} = 11 assigned to the proton transition to the ground-state of {sup 52}Fe. (author)

  8. Spin Orbit Interaction Engineering for beyond Spin Transfer Torque memory

    Science.gov (United States)

    Wang, Kang L.

    Spin transfer torque memory uses electron current to transfer the spin torque of electrons to switch a magnetic free layer. This talk will address an alternative approach to energy efficient non-volatile spintronics through engineering of spin orbit interaction (SOC) and the use of spin orbit torque (SOT) by the use of electric field to improve further the energy efficiency of switching. I will first discuss the engineering of interface SOC, which results in the electric field control of magnetic moment or magneto-electric (ME) effect. Magnetic memory bits based on this ME effect, referred to as magnetoelectric RAM (MeRAM), is shown to have orders of magnitude lower energy dissipation compared with spin transfer torque memory (STTRAM). Likewise, interests in spin Hall as a result of SOC have led to many advances. Recent demonstrations of magnetization switching induced by in-plane current in heavy metal/ferromagnetic heterostructures have been shown to arise from the large SOC. The large SOC is also shown to give rise to the large SOT. Due to the presence of an intrinsic extraordinarily strong SOC and spin-momentum lock, topological insulators (TIs) are expected to be promising candidates for exploring spin-orbit torque (SOT)-related physics. In particular, we will show the magnetization switching in a chromium-doped magnetic TI bilayer heterostructure by charge current. A giant SOT of more than three orders of magnitude larger than those reported in heavy metals is also obtained. This large SOT is shown to come from the spin-momentum locked surface states of TI, which may further lead to innovative low power applications. I will also describe other related physics of SOC at the interface of anti-ferromagnetism/ferromagnetic structure and show the control exchange bias by electric field for high speed memory switching. The work was in part supported by ERFC-SHINES, NSF, ARO, TANMS, and FAME.

  9. Quantum spin liquids: a review.

    Science.gov (United States)

    Savary, Lucile; Balents, Leon

    2017-01-01

    Quantum spin liquids may be considered 'quantum disordered' ground states of spin systems, in which zero-point fluctuations are so strong that they prevent conventional magnetic long-range order. More interestingly, quantum spin liquids are prototypical examples of ground states with massive many-body entanglement, which is of a degree sufficient to render these states distinct phases of matter. Their highly entangled nature imbues quantum spin liquids with unique physical aspects, such as non-local excitations, topological properties, and more. In this review, we discuss the nature of such phases and their properties based on paradigmatic models and general arguments, and introduce theoretical technology such as gauge theory and partons, which are conveniently used in the study of quantum spin liquids. An overview is given of the different types of quantum spin liquids and the models and theories used to describe them. We also provide a guide to the current status of experiments in relation to study quantum spin liquids, and to the diverse probes used therein.

  10. Quantum spin liquids: a review

    Science.gov (United States)

    Savary, Lucile; Balents, Leon

    2017-01-01

    Quantum spin liquids may be considered ‘quantum disordered’ ground states of spin systems, in which zero-point fluctuations are so strong that they prevent conventional magnetic long-range order. More interestingly, quantum spin liquids are prototypical examples of ground states with massive many-body entanglement, which is of a degree sufficient to render these states distinct phases of matter. Their highly entangled nature imbues quantum spin liquids with unique physical aspects, such as non-local excitations, topological properties, and more. In this review, we discuss the nature of such phases and their properties based on paradigmatic models and general arguments, and introduce theoretical technology such as gauge theory and partons, which are conveniently used in the study of quantum spin liquids. An overview is given of the different types of quantum spin liquids and the models and theories used to describe them. We also provide a guide to the current status of experiments in relation to study quantum spin liquids, and to the diverse probes used therein.

  11. The effects of conjugated linoleic acid isomers cis-9,trans-11 and trans-10,cis-12 on in vitro bovine embryo production and cryopreservation.

    Science.gov (United States)

    Absalón-Medina, V A; Bedford-Guaus, S J; Gilbert, R O; Siqueira, L C; Esposito, G; Schneider, A; Cheong, S H; Butler, W R

    2014-10-01

    Conjugated linoleic acid (CLA) isomers can affect the lipid profile and signaling of cells and thereby alter their function. A total of 5,700 bovine oocytes were used in a structured series of experiments to test the effects of CLA cis-9,trans-11 and CLA trans-10,cis-12 in vitro. In experiment 1, high doses of each CLA isomer during in vitro maturation (IVM) were compared with high or low doses during the entire in vitro culture (IVC) of parthenogenetic embryos. High doses of the CLA isomers ranged from 50 to 200 μM and low doses were 15 and 25 μM. In experiment 2, the low doses of each CLA isomer were tested during IVM/IVC on embryos produced by in vitro fertilization (IVF). Experiment 3 compared the effects of 15 μM doses of each CLA isomer during IVM or IVC of IVF embryos. In experiment 4, post-rewarming survival rates and blastomere counts were assessed for embryos supplemented with each CLA isomer during IVM or for 36 h before vitrification. In experiment 1, when either CLA isomer was provided only during IVM, we observed no effects on overall rates of maturation, cleavage, or blastocysts (92.2 ± 1.6%, 78.3 ± 4.1%, and 28.9 ± 5.1%, respectively). However, high doses of each CLA isomer, but not low doses, during the entire embryo culture period decreased blastocyst rates (5-20%) in a dose-dependent manner. Cleavage rates improved with 15 or 50 μM CLA trans-10,cis-12. Progesterone concentrations in maturation media were significantly increased by high doses of each CLA isomer compared with control, but low doses of CLA isomers had no effect. In experiment 2 with IVF embryos, low doses of each CLA isomer did not alter cleavage rates (average 84.9 ± 1.9%) and only 25 μM CLA trans-10,cis-12 during IVC reduced blastocyst rates below those of controls (25.5 ± 2.1 vs. 38.2 ± 2.3%). The lipid content of embryos was increased and relative expression of the BIRC5 (baculoviral IAP repeat containing 5) gene was depressed by CLA trans-10,cis-12. In experiment 3

  12. The difference in transfer of all-rac-α-tocopherol stereo-isomers to milk from cows and the effect on its oxidative stability

    DEFF Research Database (Denmark)

    Slots, Tina; Skibsted, Leif H.; Nielsen, Jacob Holm

    2006-01-01

    .3% (experiment I) and 88.8% (experiment II) of the isomers, indicating that transfer of the synthetic stereo-isomers to the milk was low. The milk was further exposed to fluorescent light or added copper. Milk with a high content of unsaturated fatty acids and high concentrations of α-tocopherols was more......Experiments were conducted to study the effect of all-rac-α-tocopheryl acetate supplementation of the diet of dairy cows on the oxidative stability of milk. In experiment I the cows’ feed was supplemented with 2600 IU per day per cow and in experiment II with 3400 IU and high amounts of unsaturated...

  13. High mobility 2-dimensional electron gas at LaAlO3/SrTiO3 interface prepared by spin coating chemical methods

    Science.gov (United States)

    Khan, Tahira; Zhang, Hui; Zhang, Hongrui; Yan, Xi; Hong, Deshun; Han, Furong; Chen, Yuansha; Shen, Baogen; Sun, Jirong

    2017-10-01

    Highly mobile 2-dimensional electron gases (2DEGs) at the (001), (011) and (111)-oriented LaAlO3/SrTiO3 (LAO/STO) interfaces are obtained using spin coating chemical method, which is a gentle technique without plasma bombardment of the pulsed laser deposition. As revealed by x-ray diffraction spectrum and x-ray reflectivity analysis, the LAO over layer is epitaxially grown, and has a uniform thickness of ˜15 nm, ˜20 nm and ˜26 nm for (001), (011) and (111) orientations, respectively. The interfaces are well metallic down to 2 K. The carrier mobilities are ˜28 000 cm2 V-1 s-1, ˜22 000 cm2 V-1 s-1 and ˜8300 cm2 V-1 s-1 at 2 K for the (001), (011) and (111) LAO/STO interfaces, respectively, and ˜8 cm2 V-1 s-1, ˜4 cm2 V-1 s-1 and ˜4 cm2 V-1 s-1 at room temperature. The present work shows that the spin coating chemical method is a feasible approach to get high quality 2DEG at both the polar/non-polar and polar/polar interfaces.

  14. Multi-frequency and high-field EPR study of manganese(III) protoporphyrin IX reconstituted myoglobin with an S=2 integer electron spin.

    Science.gov (United States)

    Horitani, Masaki; Yashiro, Haruhiko; Hagiwara, Masayuki; Hori, Hiroshi

    2008-04-01

    We investigate the electronic state of Mn(III) center with an integer electron spin S=2 in the manganese(III) protoporphyrin IX reconstituted myoglobin, Mn(III)Mb, by means of multi-frequency electron paramagnetic resonance (MFEPR) spectroscopy. Using a bimodal cavity resonator, X-band EPR signal from Mn(III) center in the Mn(III)Mb was observed near zero-field region. The temperature dependence of this signal indicates a negative axial zero-field splitting value, DEPR analysis shows that this signal is attributed to the transition between the closely spaced M(s)=+/-2 energy levels for the z-axis, corresponding to the heme normal. To determine the zero-field splitting (ZFS) parameters, EPR experiments on the Mn(III)Mb were performed at various temperatures for some frequencies between 30GHz and 130GHz and magnetic fields up to 14T. We observed several EPR spectra which are analyzed with a spin Hamiltonian for S=2, yielding highly accurate ZFS parameters; D=-3.79cm(-1) and |E|=0.08cm(-1) for an isotropic g=2.0. These ZFS parameters are compared with those in some Mn(III) complexes and Mn(III) superoxide dismutase (SOD), and effects on these parameters by the coordination and the symmetry of the ligands are discussed. To the best of our knowledge, these EPR spectra in the Mn(III)Mb are the very first MFEPR spectra at frequencies higher than Q-band in a metalloprotein with an integer spin.

  15. Low-temperature carrier dynamics in high-mobility organic transistors of alkylated dinaphtho-thienothiophene as investigated by electron spin resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Yutaro; Tanaka, Hisaaki, E-mail: htanaka@nuap.nagoya-u.ac.jp; Kuroda, Shin-ichi [Department of Applied Physics, Nagoya University, Chikusa, Nagoya 464-8603 (Japan); Shimoi, Yukihiro [Nanosystem Research Institute (NRI), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Takimiya, Kazuo [Emergent Molecular Function Research Group, RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198 (Japan)

    2014-07-21

    Charge carriers in high-mobility organic thin-film transistors of alkylated dinaphtho-thienothiophene (C{sub 10}-DNTT) have been directly observed by field-induced electron spin resonance (FI-ESR) down to 4 K. FI-ESR spectra of π-electron hole carriers of C{sub 10}-DNTT exhibited clear anisotropy, indicating a highly organized end-on molecular orientation at the device interface. The intra-grain and inter-grain carrier motion were probed by the motional narrowing effect of the ESR spectra. The intra-grain motion was clearly observed even at 4 K, showing intrinsically high mobility of C{sub 10}-DNTT crystallites. On the other hand, significantly low activation energy of ∼10 meV for inter-grain carrier hopping, compared with pristine DNTT, was observed, which shows that the alkyl substitution drastically enhances the carrier mobility of DNTT system.

  16. Spin states of multielectron systems and the action of multi-spin bans

    Science.gov (United States)

    Arifullin, M. R.; Berdinskii, V. L.

    2013-07-01

    Magnetic and spin effects in chemical reactions are caused by the effect of spin bans, which control the elementary acts of radical and ion-radical reactions involving, as a rule, two paramagnetic particles. Any description of spin bans acting in chemical and enzymatic reactions, which is accompanied by transfer of several electrons, as well as in the reactions of high spin molecules, requires knowledge of spin states. It is shown that spin states of multi-electron states should be described by a spin density matrix; rules for their construction are given and their properties are described. As a first step, the construction of four-density matrix is described in detail. The application of four- and three-spin density matrixes is shown for analyzing the formation of superoxide anion in respiratory chains of mitochondria.

  17. Inhomogeneous Spin Diffusion in Traps with Cold Atoms

    DEFF Research Database (Denmark)

    Heiselberg, Henning

    2012-01-01

    The spin diusion and damped oscillations are studied in the collision of two spin polarized clouds of cold atoms with resonant interactions. The strong density dependence of the diusion coecient leads to inhomogeneous spin diusion that changes from central to surface spin ow as the temperature...... increases. The inhomogeneity and the smaller nite trap size signicantly reduce the spin diusion rate at low temperatures. The resulting spin diusion rates and spin drag at longer time scales are compatible with measurements at low to high temperatures for resonant attractive interactions...

  18. Electron attachment and detachment: Electron affinities of isomers of trifluoromethylbenzonitrile

    Science.gov (United States)

    Miller, Thomas M.; Viggiano, A. A.; Friedman, Jeffrey F.; Van Doren, Jane M.

    2004-11-01

    Rate constants for electron attachment to the three isomers of trifluoromethylbenzonitrile [(CF3)(CN)C6H4, or TFMBN] were measured over the temperature range of 303-463 K in a 133-Pa He buffer gas, using a flowing-afterglow Langmuir-probe apparatus. At 303 K, the measured attachment rate constants are 9.0×10-8 (o-TFMBN), 5.5×10-8 (m-TFMBN), and 8.9×10-8 cm3 s-1 (p-TFMBN), estimated accurate to ±25%. The attachment process formed only the parent anion in all three cases. Thermal electron detachment was observed for all three anion isomers, and rate constants for this reverse process were also measured. From the attachment and detachment results, the electron affinities of the three isomers of TFMBN were determined to be 0.70(o-TFMBN), 0.67(m-TFMBN), and 0.83 eV (p-TFMBN), all ±0.05 eV. G3(MP2) [Gaussian-3 calculations with reduced Møller-Plesset orders (MP2)] calculations were carried out for the neutrals and anions. Electron affinities derived from these calculations are in good agreement with the experimental values.

  19. Three bilindione isomers: synthesis, characterization and reactivity of biliverdin analogs.

    Science.gov (United States)

    Wang, Jun-Fei; Ma, Fang; Sun, Hao-Ling; Zhang, Jing; Zhang, Jun-Long

    2017-07-01

    Linear tetrapyrrole is the core structure of light-sensitive native cofactors such as phycocyanobilin, phytochromobilin and bile pigments, which attracts increasing attention in biomimetic chemistry, photochemistry and coordination chemistry. To decipher the relationship between structures and functions, in this work, we firstly reported the synthesis, isolation and characterization of three bilindione isomers (ZZZ, syn, syn, syn 1, EZE, syn, syn, anti 2 and EZE, anti, syn, anti 3) bearing meso-pentafluorophenyl groups. The structures were confirmed by X-ray diffraction and 2-D NMR spectroscopes. More importantly, the interconversion between three isomers under heating and light irradiation was investigated, and isomer 3 was found to be transformed to 1 and 2 more easily, which is in line with the results of DFT calculation. This work provides important insights for understanding the relationship between structures and functions and would be important to further construct metal complexes based on linear tetrapyrrole ligands, which are complementary to well-studied the cyclic analogs such as porphyrin and corroles.

  20. Borromean halo, Tango halo, and halo isomers in atomic nuclei

    Science.gov (United States)

    Izosimov, Igor

    2016-01-01

    Structure of the ground and excited states in halo-like nuclei is discussed. Both the Borromean and tango halo types can be observed for n-p configurations of atomic nuclei.Structure of the halo may be different for the different levels and resonances in atomic nuclei. Isobar analog, double isobar analog, configuration, and double configuration states can simultaneously have n-n, n-p, and p-p halo components in their wave functions. When the halo structure of the excited state differs from that of the ground state, or the ground state has non-halo structure, the γ-transition from the excited state to the ground state can be essentially hindered, i.e. the formation of a specific type of isomers (halo isomers) becomes possible. B(Mγ) and B(Eγ) values for γ-transitions in 6,7,8Li, 8,9,10Be, 8,10,11B, 10,11,12,13,14C, 13,14,15,16,17N, 15,16,17,19O, and 17F are analyzed. Special attention is given to nuclei which ground state does not exhibit halo structure but the excited state (halo isomer) may have one.

  1. Distinct carbon isotope fractionation during anaerobic degradation of dichlorobenzene isomers.

    Science.gov (United States)

    Liang, Xiaoming; Mundle, Scott O C; Nelson, Jennifer L; Passeport, Elodie; Chan, Calvin C H; Lacrampe-Couloume, Georges; Zinder, Stephen H; Sherwood Lollar, Barbara

    2014-05-06

    Chlorinated benzenes are ubiquitous organic contaminants found in groundwater and soils. Compound specific isotope analysis (CSIA) has been increasingly used to assess natural attenuation of chlorinated contaminants, in which anaerobic reductive dechlorination plays an essential role. In this work, carbon isotope fractionation of the three dichlorobenzene (DCB) isomers was investigated during anaerobic reductive dehalogenation in methanogenic laboratory microcosms. Large isotope fractionation of 1,3-DCB and 1,4-DCB was observed while only a small isotope effect occurred for 1,2-DCB. Bulk enrichment factors (εbulk) were determined from a Rayleigh model: -0.8 ± 0.1 ‰ for 1,2-DCB, -5.4 ± 0.4 ‰ for 1,3-DCB, and -6.3 ± 0.2 ‰ for 1,4-DCB. εbulk values were converted to apparent kinetic isotope effects for carbon (AKIE) in order to characterize the carbon isotope effect at the reactive positions for the DCB isomers. AKIE values are 1.005 ± 0.001, 1.034 ± 0.003, and 1.039 ± 0.001 for 1,2-DCB, 1,3-DCB, and 1,4-DCB, respectively. The large difference in AKIE values between 1,2-DCB and 1,3-DCB (or 1,4-DCB) suggests distinct reaction pathways may be involved for different DCB isomers during microbial reductive dechlorination by the methanogenic cultures.

  2. A measurement of spin asymmetries in quasi-real photo-production of hadrons with high transverse momentum at COMPASS

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, R.

    2007-07-15

    During 2002-2004, the COMPASS experiment at the CERN SPS has recorded 1.5 fb{sup -1} of deep inelastic scattering events with polarized muon beam and polarized deuterium target. The cross section for single-inclusive charged hadron production in dependence on the hadron's transverse momentum p{sub T} is extracted. A PYTHIA and GEANT simulation is used to obtain the acceptance correction factors. The double spin asymmetry A{sub LL}{sup b,d} is measured in the region 1 GeV/c

  3. Magnetic Nanostructures Spin Dynamics and Spin Transport

    CERN Document Server

    Farle, Michael

    2013-01-01

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

  4. Effect of conjugated linoleic acid isomers on lipoproteins and atherosclerosis in the Syrian Golden hamster.

    Science.gov (United States)

    Mitchell, Patricia L; Langille, Morgan A; Currie, Deborah L; McLeod, Roger S

    2005-06-01

    Conjugated linoleic acid (CLA) is a group of positional and geometric isomers of linoleic acid (LA, C18:2 cis-9, cis-12) that are reported to have important biological activities, including protection against atherosclerosis. In this study, the potential role of the individual cis-9, trans-11 and trans-10, cis-12 isomers of CLA in atherogenesis were compared with LA in the Syrian Golden hamster. Supplementation of a high-fat, high-cholesterol diet (HFHC) with 1% (w/w) cis-9, trans-11 CLA or trans-10, cis-12 CLA did not significantly affect plasma cholesterol levels compared to supplementation with 1% (w/w) LA. Very low density lipoprotein cholesterol (VLDL-C) was lower and plasma triglycerides (TG) were higher in diets where C18:2 fatty acid was added to the HFHC diet, but neither the cis-9, trans-11 CLA group nor trans-10, cis-12 CLA group was significantly different from the LA control group. CLA supplementation did not significantly affect low density lipoprotein cholesterol (LDL-C). Trans-10, cis-12 CLA increased high density lipoprotein cholesterol (HDL-C) levels compared to LA or cis-9, trans-11 CLA (Phamster, but when compared to LA, the apparent atheroprotective effects do not correlate with beneficial changes in lipoprotein profile.

  5. Toward the laboratory identification of the not-so-simple NS2 neutral and anion isomers

    Science.gov (United States)

    Fortenberry, Ryan C.; Thackston, Russell; Francisco, Joseph S.; Lee, Timothy J.

    2017-08-01

    The NS2 radical is a simple arrangement of atoms with a complex electronic structure. This molecule was first reported by Hassanzadeh and Andrew's group [J. Am. Chem. Soc. 114, 83 (1992)] through Ar matrix isolation experiments. In the quarter century since this seminal work was published, almost nothing has been reported about nitrogen disulfide even though NS2 is isovalent with the common NO2. The present study aims to shed new insight into possible challenges with the characterization of this radical. No less than three potential energy surfaces all intersect in the C2v region of the SNS radical isomer. A type-C Renner-Teller molecule is present for the linear 2Πu state where the potential energy surface is fully contained within the 2.05 kcal/mol lower energy X ˜ 2A1 state. A C2v, 1 2B1 state is present in this same region, but a double excitation is required to access this state from the X ˜ 2A1 state of SNS. Additionally, a 1 2A' NSS isomer is also present but with notable differences in the geometry from the global minimum. Consequently, the rovibronic spectrum of these NS2 isomers is quite complicated. While the present theory and previous Ar matrix experiments agree well on isotopic shifts, they differ notably for the absolute fundamental vibrational frequency transitions. These differences are likely a combination of matrix shifts and issues associated with the neglect of non-adiabatic coupling in the computations. In either case, it is clear that high-resolution gas phase experimental observations will be complicated to sort. The present computations should aid in their analysis.

  6. Occurrence, fluxes and sources of perfluoroalkyl substances with isomer analysis in the snow of northern China

    Energy Technology Data Exchange (ETDEWEB)

    Shan, Guoqiang; Chen, Xinwei; Zhu, Lingyan, E-mail: zhuly@nankai.edu.cn

    2015-12-15

    Highlights: • Relatively high levels of PFASs were present in the snow in northern China in 2013. • Particulate bound PFASs contributed 21.5–56.2% to the total PFASs in snow. • Particulate matters are vital for PFASs transport and deposition in urban atmosphere. • Partitioning of PFASs between particulate and dissolved phase was related to carbon chain length. • Isomer profiles in snow suggested that airborne PFASs were mainly from direct release. - Abstract: In this study, perfluoroalkyl substances (PFASs) and the isomers of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) were analyzed in fresh snow samples collected from 19 cities in northern China, 2013. The levels of total PFASs in the snow samples were 33.5–229 ng/L, suggesting heavy atmospheric pollution of PFASs in northern China. PFOA (9.08–107 ng/L), PFOS (3.52–54.3 ng/L), perfluoroheptanoate (PFHpA) (3.66–44.8 ng/L), and perfluorohexanoate (PFHxA) (3.21–23.6 ng/L) were predominant with a summed contribution of 82% to the total PFASs. The particulate matters (PMs) associated PFASs contributed 21.5–56.2% to the total PFASs in the snow, suggesting PMs are vital for the transport and deposition of airborne PFASs. Partitioning of PFASs between PM and dissolved phases was dependent on the carbon chain length and end functional groups. Isomer profiles of PFOA and PFOS in the snow were in agreement with the signature of the historical 3 M electrochemical fluorination (ECF) products, suggesting that the ECF products were still produced and used in China. Further source analysis showed that the airborne PFASs in urban area were mainly due to direct release rather than degradation of their precursors.

  7. High-pressure sequence of Ba3NiSb2O9 structural phases: new S = 1 quantum spin liquids based on Ni2+.

    Science.gov (United States)

    Cheng, J G; Li, G; Balicas, L; Zhou, J S; Goodenough, J B; Xu, Cenke; Zhou, H D

    2011-11-04

    Two new gapless quantum spin-liquid candidates with S = 1 (Ni(2+)) moments: the 6H-B phase of Ba(3)NiSb(2)O(9) with a Ni(2+)-triangular lattice and the 3C phase with a Ni(2/3)Sb(1/3)-three-dimensional edge-shared tetrahedral lattice were obtained under high pressure. Both compounds show no magnetic order down to 0.35 K despite Curie-Weiss temperatures θ(CW) of -75.5 (6H-B) and -182.5 K (3C), respectively. Below ~25 K, the magnetic susceptibility of the 6H-B phase saturates to a constant value χ(0) = 0.013 emu/mol, which is followed below 7 K by a linear-temperature-dependent magnetic specific heat (C(M)) displaying a giant coefficient γ = 168 mJ/mol K(2). Both observations suggest the development of a Fermi-liquid-like ground state. For the 3C phase, the C(M) perpendicular T(2) behavior indicates a unique S = 1, 3D quantum spin-liquid ground state.

  8. PROCEEDINGS OF RIKEN BNL RESEARCH CENTER WORKSHOP ON RHIC SPIN PHYSICS III AND IV, POLARIZED PARTONS AT HIGH Q2 REGION, AUGUST 3, 2000 AT BNL, OCTOBER 14, 2000 AT KYOTO UNIVERSITY.

    Energy Technology Data Exchange (ETDEWEB)

    BUNCE, G.; VIGDOR, S.

    2001-03-15

    International workshop on II Polarized Partons at High Q2 region 11 was held at the Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, Japan on October 13-14, 2000, as a satellite of the international conference ''SPIN 2000'' (Osaka, Japan, October 16-21,2000). This workshop was supported by RIKEN (The Institute of Physical and Chemical Research) and by Yukawa Institute. The scientific program was focused on the upcoming polarized collider RHIC. The workshop was also an annual meeting of RHIC Spin Collaboration (RSC). The number of participants was 55, including 28 foreign visitors and 8 foreign-resident Japanese participants, reflecting the international nature of the RHIC spin program. At the workshop there were 25 oral presentations in four sessions, (1) RHIC Spin Commissioning, (2) Polarized Partons, Present and Future, (3) New Ideas on Polarization Phenomena, (4) Strategy for the Coming Spin Running. In (1) the successful polarized proton commissioning and the readiness of the accelerator for the physics program impressed us. In (2) and (3) active discussions were made on the new structure function to be firstly measured at RHIC, and several new theoretical ideas were presented. In session (4) we have established a plan for the beam time requirement toward the first collision of polarized protons. These proceedings include the transparencies presented at the workshop. The discussion on ''Strategy for the Coming Spin Running'' was summarized by the chairman of the session, S. Vigdor and G. Bunce.

  9. High-T C fully compensated ferrimagnetic semiconductors as spin-filter materials: the case of CrVXAl (X = Ti, Zr, Hf) Heusler compounds.

    Science.gov (United States)

    Galanakis, I; Özdoğan, K; Şaşıoglu, E

    2014-02-26

    We extend our recent work on spin-filter materials (Galanakis et al 2013 Appl. Phys. Lett.103 142404) to the case of CrVXAl (X = Ti, Zr, Hf) compounds, for which, using ab initio electronic structure calculations, we show that p-d hybridization leads to the formation of a fully compensated ferrimagnetic semiconducting state with moderate exchange splitting. The magnetism is of covalent-type and the very strong antiferromagnetic Cr-V exchange interactions lead to extremely high Curie temperature, TC, values. Furthermore, all three compounds are thermodynamically and magnetically stable. The combination of very high TC values with a zero total net magnetization makes them promising materials for spintronics applications.

  10. 1H High Resolution Magic-Angle Coil Spinning (HR-MACS µNMR Metabolic Profiling of whole Saccharomyces cervisiae cells: A Demonstrative Study

    Directory of Open Access Journals (Sweden)

    Alan eWong

    2014-06-01

    Full Text Available The low sensitivity of Nuclear Magnetic Resonance (NMR is its prime shortcoming compared to other analytical methods for metabolomic studies. It relies on large sample volume (30–50 µl for HR-MAS for rich metabolic profiling, hindering high-throughput screening especially when the sample requires a labor-intensive preparation or is a sacred specimen. This is indeed the case for some living organisms. This study evaluates a 1H HR-MAS approach for metabolic profiling of small volume (250 nl whole bacterial cells, Saccharomyces cervisiae, using an emerging micro-NMR technology: high-resolution magic-angle coil spinning (HR-MACS. As a demonstrative study for whole cells, we perform two independent metabolomics studies identifying the significant metabolites associated with osmotic stress and aging.

  11. 1H High Resolution Magic-Angle Coil Spinning (HR-MACS) - NMR Metabolic Profiling of whole Saccharomyces cervisiae cells: A Demonstrative Study

    Science.gov (United States)

    Wong, Alan; Boutin, Celine; Aguiar, Pedro

    2014-06-01

    The low sensitivity of Nuclear Magnetic Resonance (NMR) is its prime shortcoming compared to other analytical methods for metabolomic studies. It relies on large sample volume (30-50 µl for HR-MAS) for rich metabolic profiling, hindering high-throughput screening especially when the sample requires a labor-intensive preparation or is a sacred specimen. This is indeed the case for some living organisms. This study evaluates a 1H HR-MAS approach for metabolic profiling of small volume (250 nl) whole bacterial cells, Saccharomyces cervisiae, using an emerging micro-NMR technology: high-resolution magic-angle coil spinning (HR-MACS). As a demonstrative study for whole cells, we perform two independent metabolomics studies identifying the significant metabolites associated with osmotic stress and aging.

  12. Decoherence dynamics of a single spin versus spin ensemble

    NARCIS (Netherlands)

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

    2008-01-01

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

  13. Characterization of Individual Isopropylated and tert-Butylated Triarylphosphate (ITP and TBPP) Isomers in Several Commercial Flame Retardant Mixtures and House Dust Standard Reference Material SRM 2585.

    Science.gov (United States)

    Phillips, Allison L; Hammel, Stephanie C; Konstantinov, Alex; Stapleton, Heather M

    2017-11-21

    Since the phase-out of pentaBDE in the early 2000s, replacement flame-retardant mixtures including Firemaster 550 (FM 550), Firemaster 600 (FM 600), and organophosphate aryl ester technical mixtures have been increasingly used to treat polyurethane foam in residential upholstered furniture. These mixtures contain isomers of isopropylated and tert-butylated triarylphosphate esters (ITPs and TBPPs), which have similar or greater neuro- and developmental toxicity compared to BDE 47 in high-throughput assays. Additionally, human exposure to ITPs and TBPPs has been demonstrated to be widespread in several recent studies; however, the relative composition of these mixtures has remained largely uncharacterized. Using available authentic standards, the present study quantified the contribution of individual ITP and TBPP isomers in four commercial flame retardant mixtures: FM 550, FM 600, an ITP mixture, and a TBPP mixture. Findings suggest similarities between FM 550 and the ITP mixture, with 2-isopropylphenyl diphenyl phosphate (2IPPDPP), 2,4-diisopropylphenyl diphenyl phosphate (24DIPPDPP), and bis(2-isopropylphenyl) phenyl phosphate (B2IPPPP) being the most prevalent ITP isomers in both mixtures. FM 600 differed from FM 550 in that it contained TBPP isomers instead of ITP isomers. These analytes were also detected and quantified in a house dust standard reference material, SRM 2585, demonstrating their environmental relevance.

  14. Spin dynamics on cyclic iron wheels in high magnetic fields; Spindynamik an zyklischen Eisen-Raedern in hohen magnetischen Feldern

    Energy Technology Data Exchange (ETDEWEB)

    Schnelzer, Lars

    2008-02-15

    In the present thesis the spin dynamics of cyclic spin-cluster compounds, the so called ''ferric wheels'' were studied by means of the NMR. In the iron wheels Li/Na rate at Fe{sub 6}(tea){sub 6} and Cs rate at Fe{sub 8}(tea){sub 8} as probes of NMR both the protons and the centrally lying alkali atoms {sup 7}Li, {sup 23}Na, and {sup 133}Cs were available. For this purpose measurements in the magnetic field region up to B=20 T and at temperatures between room temperature and T=50 mK were performed. The longitudinal relaxation rate was temperature dependently studied at two field values on the lithium cluster and a frequency independent maximum of the relaxation rate at a temperature of T{approx}30 K resulted. Different behaviour showed the measurement on the sodium cluster. the longitudinal relaxation rate slopes linearly with the temperature and shows no maximum. The two quadrupole satellites of the {sup 23}Na could be resolved. From the distance of the satellites to the central transition both on the field gradient of the iron ring and on the orientation of the symmetry axis to the external magnetic field could be concluded. The determined field gradient of the Na rate at Fe{sub 6}(tea){sub 6} of eq=4.78(11).10{sup 20} V/m{sup 2} was in very good agreement with the present theoretically calculated value. The orientation of the crystal was determined to {theta}(c,B)=62.8 . The very low splitting of the {sup 7}Li NMR spectrum of the lithium cluster allows to give as upper limit for the value of the field gradient eq=1.82(11).10{sup 20} V/m{sup 2}. From the seven lines of the cesium spectrum theoretically to be expected five were resolved. The evaluation yielded for the cesium ring a value of eq=-1.3(1).10{sup 21} V/m{sup 2}. The study of the field-dependent line position of the {sup 23}Na NMR line led to the determination of the parameter of the transferred hyperfine interaction to A{sub tHf}/2{pi}=140 kHz. For the first time on a cyclic iron

  15. Evidence for single-chain magnet behavior in a Mn(III)-Ni(II) chain designed with high spin magnetic units: a route to high temperature metastable magnets.

    Science.gov (United States)

    Clérac, Rodolphe; Miyasaka, Hitoshi; Yamashita, Masahiro; Coulon, Claude

    2002-10-30

    . This result indicates the presence of a metastable state without magnetic long-range order. This material is the first experimental design of a heterometallic chain with ST = 3 magnetic units showing a "single-chain magnet" behavior predicted in 1963 by R. J. Glauber for an Ising one-dimensional system. This work opens new perspectives for one-dimensional systems to obtain high temperature metastable magnets by combining high spin magnetic units, strong interunit interactions, and uniaxial anisotropy.

  16. Bias-independent spin signals in a tunnel-junction-based non-local spin valve

    Science.gov (United States)

    Wang, Xiaojun; Zou, Han; Ocola, L. E.; Divan, R.; Ji, Yi

    2009-03-01

    A pure spin current can be generated in the non-magnetic component of a non-local spin valve (NLSV). It has been demonstrated recently that the pure spin current can be used for spin transfer torque and spin-Hall effects. A high spin current density is desirable for realizing these effects, and therefore a large d.c. bias current will be applied. It is essential to maintain high degree of spin polarization at a high bias current. It has been previously reported that the spin polarization decreases drastically in a tunnel-junction-based CoFe/Al/NiFe NLSV. The goal of this study is to investigate the dependence of spin signals upon a d.c. bias current in tunnel-junction-based Co/Cu/Co NLSV's. Submicron Co/Cu/Co NLSV's are fabricated by e-beam lithography combined with angle deposition. A layer of 2 nm Al2O3 is deposited at the Co/Cu interface to form a tunnel barrier. A spin signal > 1mφ is observed at room temperature (RT). A d.c. current up to 1.0mA is applied at both 4.2 K and RT. No change of spin signal is observed for an injection current density > 10^6 A/cm^2.

  17. Spin transport properties in a double quantum ring with Rashba spin-orbit interaction

    Science.gov (United States)

    Naeimi, Azadeh S.; Eslami, Leila; Esmaeilzadeh, Mahdi; Abolhassani, Mohammad Reza

    2013-01-01

    We study spin-resolved electron transport in a double quantum ring in the presence of Rashba spin-orbit interaction and a magnetic flux using quantum waveguide theory. We show that, at the proper values of the system parameters such as the Rashba coupling constant, the radius of the rings, and the angle between the leads, the double quantum ring can act as a perfect electron spin-inverter with very high efficiency. Also, the double quantum ring can work as a spin switch. The spin polarization of transmitted electrons can be controlled and changed from -1 to +1 by using a magnetic flux.

  18. Direct observation of low energy nuclear spin excitations in HoCrO3 by high resolution neutron spectroscopy.

    Science.gov (United States)

    Chatterji, T; Jalarvo, N; Kumar, C M N; Xiao, Y; Brückel, Th

    2013-07-17

    We have investigated low energy nuclear spin excitations in the strongly correlated electron compound HoCrO3. We observe clear inelastic peaks at E = 22.18 ± 0.04 μeV in both energy loss and gain sides. The energy of the inelastic peaks remains constant in the temperature range 1.5-40 K at which they are observed. The intensity of the inelastic peak increases at first with increasing temperature and then decreases at higher temperatures. The temperature dependence of the energy and intensity of the inelastic peaks is very unusual compared to that observed in other Nd, Co, V and also simple Ho compounds. Huge quasielastic scattering appears at higher temperatures presumably due to the fluctuating electronic moments of the Ho ions that get increasingly disordered at higher temperatures. The strong quasielastic scattering may also originate in the first Ho crystal-field excitations at about 1.5 meV.

  19. Reaction between peroxynitrite and triphenylphosphonium-substituted arylboronic acid isomers: identification of diagnostic marker products and biological implications.

    Science.gov (United States)

    Sikora, Adam; Zielonka, Jacek; Adamus, Jan; Debski, Dawid; Dybala-Defratyka, Agnieszka; Michalowski, Bartosz; Joseph, Joy; Hartley, Richard C; Murphy, Michael P; Kalyanaraman, Balaraman

    2013-06-17

    Aromatic boronic acids react rapidly with peroxynitrite (ONOO(-)) to yield phenols as major products. This reaction was used to monitor ONOO(-) formation in cellular systems. Previously, we proposed that the reaction between ONOO(-) and arylboronates (PhB(OH)2) yields a phenolic product (major pathway) and a radical pair PhB(OH)2O(•-)···(•)NO2 (minor pathway). [Sikora, A. et al. (2011) Chem. Res. Toxicol. 24, 687-697]. In this study, we investigated the influence of a bulky triphenylphosphonium (TPP) group on the reaction between ONOO(-) and mitochondria-targeted arylboronate isomers (o-, m-, and p-MitoPhB(OH)2). Results from the electron paramagnetic resonance (EPR) spin-trapping experiments unequivocally showed the presence of a phenyl radical intermediate from meta and para isomers, and not from the ortho isomer. The yield of o-MitoPhNO2 formed from the reaction between o-MitoPhB(OH)2 and ONOO(-) was not diminished by phenyl radical scavengers, suggesting a rapid fragmentation of the o-MitoPhB(OH)2O(•-) radical anion with subsequent reaction of the resulting phenyl radical with (•)NO2 in the solvent cage. The DFT quantum mechanical calculations showed that the energy barrier for the dissociation of the o-MitoPhB(OH)2O(•-) radical anion is significantly lower than that of m-MitoPhB(OH)2O(•-) and p-MitoPhB(OH)2O(•-) radical anions. The nitrated product, o-MitoPhNO2, is not formed by the nitrogen dioxide radical generated by myeloperoxidase in the presence of the nitrite anion and hydrogen peroxide, indicating that this specific nitrated product may be used as a diagnostic marker product for ONOO(-). Incubation of o-MitoPhB(OH)2 with RAW 264.7 macrophages activated to produce ONOO(-) yielded the corresponding phenol o-MitoPhOH as well as the diagnostic nitrated product, o-MitoPhNO2. We conclude that the ortho isomer probe reported here is most suitable for specific detection of ONOO(-) in biological systems.

  20. Production of the $^{178m2}$Hf Isomer Using a 4.5-GeV Electron Accelerator

    CERN Document Server

    Karamian, S A; Adam, J; Demekhina, N A

    2004-01-01

    High-productivity methods are required for the accumulation of long-lived isomers in amounts that are sufficient for the creation of experimental targets. A tantalum sample was activated with the Yerevan synchrotron using 4.5-GeV bremsstrahlung and the presence of ^{178m2}Hf was detected with good statistical accuracy by gamma-activity measurements. The integrated and mean cross-section values were deduced from the experiment. The isomer-to-ground-state ratio was then estimated and compared with that known for the p+Ta reaction studied at 660 MeV. In the present experiment, both the converter and the target were relatively thin for better definition of the experimental conditions. However, an assembly designed for high-productivity irradiations should be thick and the converter can also serve as a target sample when irradiated with a high-energy electron beam. The optimization of the isomer production was solved analytically and the largest estimated yield was determined as calibrated to the experimental yiel...