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Sample records for high-spin states produced

  1. High spin states in 78Sr

    NASA Astrophysics Data System (ADS)

    Gross, C. J.; Heese, J.; Lieb, K. P.; Lister, C. J.; Varley, B. J.; Chishti, A. A.; McNeill, J. H.; Gelletly, W.

    1989-05-01

    78Sr was produced in the reaction 58Ni(24Mg, 2p2n) with a relative cross section of less than 2.5% of the total fusion cross section at 110 MeV, but high spin states up to 16ħ were firmly identified. Fifteen neutron detectors and fifteen Compton suppressed Ge detectors were used in a large solid angle arrangement. 2nγγ and nγγ coincidences were recorded. A small irregularity in the dynamic moment of inertia J(2)/ħ2 is evidence for a strongly mixed band crossing at ħω~=0.55 MeV in agreement with what is observed in 80,82Sr.

  2. High spin states of [sup 84]Sr

    SciTech Connect

    Garcia Bermudez, G.; Baktash, C.; Abenante, V.; Griffin, H.C.; Halbert, M.L.; Hensley, D.C.; Johnson, N.R.; Lee, I.Y.; McGowan, F.K.; Riley, M.A.; Sarantites, D.G.; Semkow, T.M.; Stracener, D.W.; Virtanen, A. Joint Institute for Heavy-Ion Research, Oak Ridge, Tennessee 37831 Departamento de Fisica, Comision Nacional de Energia Atomica, 1429 Buenos Aires Department of Chemistry, Washington University, Saint Louis, Missouri 63130 Department of chemistry, University of Michigan, Ann Arbor, Michigan 48104 )

    1994-06-01

    High spin states of [sup 84]Sr nucleus excited through the [sup 52]Cr([sup 36]S,2[ital p]2[ital n]) reaction at 130 MeV energy were studied utilizing the Oak Ridge Compton-Suppression Spectrometer System. The level scheme has been extended up to probably [ital I][sup [pi

  3. Neutron-deficient N{approx_equal}126 nuclei produced in 238U fragmentation: population of high-spin states

    SciTech Connect

    Podolyak, Zs.; Regan, P. H.; Walker, P. M.; Pearson, C. J.; Valiente-Dobon, J. J.; Gerl, J.; Hellstroem, M.; Becker, F.; Gorska, M.; Kelic, A.; Kopatch, Y.; Mandal, S.; Schmidt, K.-H.; Wollersheim, H. J.; Banu, A.; Geissel, H.; Grawe, H.; Kojouharov, I.; Lozeva, R.; Portillo, M.

    2006-04-26

    The population of metastable states produced in relativistic-energy fragmentation of a 238U beam has been measured. For states with high angular momentum, I=17({Dirac_h}/2{pi}) and I=21.5({Dirac_h}/2{pi}), a higher population than expected has been observed, with the discrepancy increasing with angular momentum. By considering two sources for the angular momentum, related to single-particle and collective motions, a much improved description of the experimental results can be obtained. In addition, new results on the structure of 208Fr, 211Ra and 216Ac are reported.

  4. High-spin states of ZXRh

    SciTech Connect

    Piel W.F. Jr.; Scharff-Goldhaber, G.; Lister, C.J.; Varley, B.J.

    1986-02-01

    High-spin states of ZXRh up to J = ((31/2)) and an excitation energy of 7.1 MeV were established by means of the WNi(UCa,3pel)ZXRh reaction. The states are found to decay through two separate el-ray cascades with the assignments for the lower-spin states being in agreement with previous work. No strong evidence has been found for the existence of collectivity induced by intruder states. The empirical excitation energies are compared to those found recently for the nearby even-A isotones ZWRu and ZYPd, and the systematics of the N = 52 nuclides are discussed.

  5. High-spin states in ^88Kr

    NASA Astrophysics Data System (ADS)

    Fotiades, N.; Lisetskiy, A. F.; Cizewski, J. A.; Krücken, R.; Clark, R. M.; Fallon, P.; Lee, I. Y.; Macchiavelli, A. O.; Becker, J. A.; Younes, W.

    2007-10-01

    High-spin states in ^88Kr have been studied following the fission of the ^226Th compound nucleus formed in a fusion-evaporation reaction (^18O at 91 MeV on ^208Pb). The Gammasphere array was used to detect γ-ray coincidences. High-spin states up to spin (14^+) and ˜8 MeV excitation energy have been established. The level scheme reported for ^88Kr in the spontaneous fission of ^248Cm [1] has been enriched and extended to higher spin and excitation energies. Differences between the level scheme reported in [1] and that obtained in the present work will be discussed. The observed experimental states are also compared with theoretical shell-model and interacting-boson-model-2 calculations. This work has been supported by the U.S. Department of Energy under Contracts No. DE-AC52-06NA25396 (LANL), W-7405-ENG-48 (LLNL) and AC03-76SF00098 (LBNL) and by the National Science Foundation (Rutgers). [1] T. Rzaca-Urban et al., Eur. Phys. J. A 9, 165 (2000).

  6. High-spin states in 127I

    NASA Astrophysics Data System (ADS)

    Ding, B.; Zhang, Y. H.; Zhou, X. H.; Dong, G. X.; Xu, F. R.; Liu, M. L.; Li, G. S.; Zhang, N. T.; Wang, H. X.; Zhou, H. B.; Ma, Y. J.; Sasakiz, Y.; Yamada, K.; Ohshima, H.; Yokose, S.; Ishizuka, M.; Komatsubara, T.; Furuno, K.

    2012-04-01

    In-beam γ spectroscopy of the stable nucleus 127I has been studied experimentally using the 124Sn(7Li, 4nγ)127I reaction at a beam energy of 32 MeV. The high-spin level scheme of 127I is extended significantly. Negative-parity levels built on the 11/2-, πh11/2 particle state are observed up to (35/2-) and described as a decoupled band, extending our knowledge of decoupled structures to the most neutron-rich stable iodine isotope. Two ΔI=2 yrast positive-parity sequences are proposed to be associated with the πg7/2 configuration due to observations of several strong interband transitions, and two weakly populated ΔI=2 positive-parity bands are newly identified and interpreted as arising mainly from the πd5/2 configuration. Three-quasiparticle configurations are assigned to the Iπ=15/2+ and 23/2+ states according to the existing knowledge in neighboring nuclei; irregular noncollective and regular collective excitations built on these two (15/2+ and 23/2+) states are observed to coexist at similar energies. The observed three-quasiparticle band structures are further interpreted with the aid of configuration-constrained potential energy surface calculations.

  7. High spin states in {sup 139}Pm

    SciTech Connect

    Dhal, A.; Sinha, R. K.; Chaturvedi, L.; Agarwal, P.; Kumar, S.; Jain, A. K.; Kumar, R.; Govil, I. M.; Mukhopadhyay, S.; Chakraborty, A.; Krishichayan; Ray, S.; Ghugre, S. S.; Sinha, A. K.; Kumar, R.; Singh, R. P.; Muralithar, S.; Bhowmik, R. K.; Pancholi, S. C.; Gupta, J. B.

    2009-07-15

    The odd mass nucleus {sup 139}Pm has been studied to high spins through the {sup 116}Cd({sup 27}Al,4n){sup 139}Pm reaction at an incident beam energy of 120 MeV. The de-exciting {gamma}-rays were detected using an array of 12 Compton suppressed Ge detectors. A total of 46 new levels have been proposed in the present work as a result of the observation of 60 new {gamma}-rays. Four new bands including a {delta}J=1 sequence have been identified and all the earlier reported bands, other than the yrast band, have been extended to higher spins and excitation energy. The spin assignments for most of the newly reported levels have been made using the observed coincidence angular anisotropy. Tilted axis cranking calculations support the interpretation of two of the observed magnetic dipole sequences as examples of magnetic rotational bands.

  8. High-spin states in the 94Nb nucleus

    NASA Astrophysics Data System (ADS)

    Mărginean, N.; Bucurescu, D.; Căta-Danil, Ghe.; Căta-Danil, I.; Ivaşcu, M.; Ur, C. A.

    2000-09-01

    High-spin states have been studied for the first time in the 94Nb nucleus with the reaction 82Se(19F,α3nγ) at 68 MeV. A cascade of transitions has been observed, based on the (6)+ ground state and extending up to 6.5 MeV excitation and spin of about 19.

  9. High-spin states in 208Rn

    NASA Astrophysics Data System (ADS)

    Triggs, W. J.; Poletti, A. R.; Dracoulis, G. D.; Fahlander, C.; Byrne, A. P.

    1983-03-01

    The yrast decay scheme of 208Rn has been investigated up to spin ≈ 20 h̵ and an excitation energy of ≈ 6 MeV. Several different γ-ray spectroscopic techniques were used to determine the properties of excited states and transitions in the nucleus. Significant changes to the previously established level scheme are proposed, based on the existence of an unobserved 3.1 keV transition. Simple empirical shell-model calculations of level energies aided in the assignment of shell-model configurations to excited states and the decay scheme is discussed in terms of these configurations. The energy level systematics for the even radon isotopes, from A = 206 to 212 are discussed, as are core polarization effects in the even radon isotopes ( A = 204 to 210) and polonium isotopes ( A = 202-208).

  10. High-spin states in the 97Tc nucleus

    NASA Astrophysics Data System (ADS)

    Bucurescu, D.; Gadea, A.; Căta-Danil, Ghe.; Căta-Danil, I.; Ivaşcu, M.; Mărginean, N.; Rusu, C.; Stroe, L.; Ur, C. A.

    High-spin states in the 97Tc nucleus have been studied by in-beam γ-ray spectroscopy with the reaction 82Se(19F,4nγ) at 68 MeV incident energy. Excited states have been observed up to about 8 MeV excitation and spin 43/2ℎ. The observed level scheme is compared with results of shell model calculations.

  11. Lifetimes of high-spin states in 74Kr

    SciTech Connect

    Valiente-Dobon, J. J.; Svensson, C. E.; Grinyer, G. F.; Hyland, B.; Phillips, A. A.; Schumaker, M. A.; Steinhardt, T.; Eberth, J.; Stefanescu, I.; Thelen, O.; Afanasjev, A. V.; Ragnarsson, I.; Andreoiu, C.; Austin, R. A. E.; Carpenter, M. P.; Freeman, S. J.; Moore, F.; Mukherjee, G.; Seweryniak, D.; Dashdorj, D.

    2006-04-26

    High-spin states in {sub 36}{sup 74}Kr{sub 38} were studied using the 40Ca(40Ca,{alpha}2p)74Kr fusion evaporation reaction at a beam energy of 165 MeV with GAMMASPHERE and MICROBALL and at a beam energy of 185 MeV with EUROBALL and ISIS multi-detector arrays. Lifetimes of the high-spin states for the ground-state band and the favoured negative-parity band have been determined using the Doppler-shift attenuation method. The deduced transition quadrupole moments show a marginal decrease as a function of spin, suggesting that the rotational bands do not terminate at the maximum spin Imax.

  12. High-spin states in the 96Tc nucleus

    NASA Astrophysics Data System (ADS)

    Bucurescu, D.; Căta-Danil, Gh.; Căta-Danil, I.; Ivaşcu, M.; Mărginean, N.; Rusu, C.; Stroe, L.; Ur, C. A.; Gizon, A.; Gizon, J.; Nyakó, B.; Timár, J.; Zolnai, L.; Boston, A. J.; Joss, D. T.; Paul, E. S.; Semple, A. T.; Parry, C. M.

    High-spin states in the 96Tc nucleus have been studied with the reactions 82Se(19F,5nγ) at 68 MeV and Zn(36S,αpxn) at 130 MeV. Two γ-ray cascades (irregular bandlike structures) have been observed up to an excitation energy of about 10 MeV and spin 21-22?.

  13. Lifetime measurement of high spin states in (75) Kr

    SciTech Connect

    Sheikh, Javid; Trivedi, T.; Maurya, K.; Mehrotra, I.; Palit, R.; Naik, Z.; Jain, H. C.; Negi, D.; Mahanto, G.; Kumar, R.; Singh, R.P.; Muralithar, S.; Pancholi, S.C.; Bhowmik, R.K.; Yang, Y-C; Sun, Y.; Dahl, A.; Raju, M.K.; Appannababu, S.; Kumar, S.; Choudhury, D.; Jain, A. K.

    2010-01-01

    The lifetimes of high spin states of {sup 75}Kr have been determined via {sup 50}Cr ({sup 28}Si, 2pn) {sup 75}Kr reaction in positive parity band using the Doppler-shift attenuation method. The transition quadrupole moments Q deduced from lifetime measurements have been compared with {sup 75}Br. Experimental results obtained from lifetime measurement are interpreted in the framework of projected shell model.

  14. High-spin states and band terminations in 49V

    NASA Astrophysics Data System (ADS)

    Rodrigues, D.; Hojman, D.; Lenzi, S. M.; Cardona, M. A.; Farnea, E.; Axiotis, M.; Beck, C.; Bednarczyk, P.; Bizzetti, P. G.; Bizzetti-Sona, A. M.; Della Vedova, F.; Grebosz, J.; Haas, F.; Kmiecik, M.; Maj, A.; Meczyński, W.; Napoli, D. R.; Nespolo, M.; Papka, P.; Zafra, A. Sánchez i.; Styczen, J.; Thummerer, S.; Ziebliński, M.

    2015-08-01

    High-spin states in 49V have been studied through the 28Si(28Si,α 3 p ) reaction using the EUROBALL γ -ray detector array. The 49V level scheme has been extended up to 13.1 MeV including 21 new states. Both negative and positive parity states have been interpreted in the framework of the shell model. The 27 /2- and the 31/2 + band-termination states have been observed in agreement with theoretical predictions.

  15. Lifetimes of High-Spin States in 76Kr

    NASA Astrophysics Data System (ADS)

    Valiente-Dobon, J. J.; Svensson, C. E.; O'Leary, C. D.; Ragnarsson, I.; Andreoiu, C.; Austin, R. A. E.; Carpenter, M. P.; Dashdorj, D.; Finlay, P.; Freeman, S. J.; Garrett, P. E.; Goergen, A.; Greene, J.; Grinyer, G. F.; Hyland, B.; Jenkins, D.; Johnston-Theasby, F.; Joshi, P.; Kelsall, N. S.; Macchiavelli, A. O.; Moore, F.; Mukherjee, G.; Phillips, A. A.; Reviol, W.; Sarantites, D.; Schumaker, M. A.; Seweryniak, D.; Smith, M. B.; Wadsworth, R.; Ward, D.

    2005-04-01

    High-spin states in 7636Kr40 have been populated in the 40Ca(40Ca,4p)76Kr fusion-evaporation reaction at a beam energy of 165 MeV, and studied using the GAMMASPHERE and MICROBALL multi-detector arrays. The ground-state band and two signature-split negative-parity bands of 76Kr have been extended to ˜ 30hbar. Lifetime measurements using the Doppler-shift attenuation method indicate that the transition quadrupole moment of these three bands decrease as they approach their maximum-spin states.

  16. Lifetimes of high-spin states in {sup 162}Yb

    SciTech Connect

    Carpenter, M.P.; Janssens, R.V.F.; Henry, R.G.

    1995-08-01

    A measurement on lifetimes of high-spin states in the yrast and near-yrast rotational bands in {sup 162}Yb was carried out at ATLAS in order to determine the evolution of collectivity as a function of angular momentum using the {sup 126}Te({sup 40}Ar,4n){sup 162}Yb reaction at 170 MeV. Previous lifetime measurements in the {sup 164,166,168}Yb isotopes showed a dramatic decrease in the transition quadrupole moment Q{sub t} with increasing spin. It was suggested that this decrease in Q{sub t} is brought about by the rotationally-induced deoccupation of high-j configurations, mainly i{sub 13/2} neutrons. If this interpretation is correct, the heavier isotopes should have a larger decrease in Q{sub t} than the lighter mass nuclides due to the position of the Fermi surface in the i{sub 13/2} subshell. Indeed, {sup 160}Yb does not show a clear decrease in Q{sub t} at high spin. No high spin lifetime information exists for {sup 162}Yb, thus this experiment fills the gap of measured Q{sub t}`s in the light Yb series. The data is currently being analyzed.

  17. Collectivity of high spin states in {sup 84}Zr

    SciTech Connect

    Lister, C.J.; Blumenthal, D.; Crowell, B.

    1995-08-01

    {sup 84}Zr is one of the most extensively studied of the A {approximately} 80 rotors, both from theoretical and experimental approaches. It was predicted to be a good candidate to support superdeformation, and to show interesting spectroscopic properties including saturation of its shell-model space at lower spin. We performed an experiment using Gammasphere in its early implementation phase. The reaction of {sup 29}Si on {sup 58}Ni was used to strongly populate {sup 84}Zr at high spin. Thin and thick targets were used to allow the extraction of transitional matrix elements at very high spin, and to allow a sensitive search for superdeformed states. Data analysis is in progress. The large data set allowed us to extend the previously known bands considerably. Candidates for a staggered M1-band, found previously {sup 86}Zr, were located. To date, no evidence for superdeformed bands was found. Analysis was slowed by the relocation of all the participants in this experiment, but we hope to complete the lifetime analysis this year. This analysis has become especially topical, due to reported measurements of superdeformation in this region.

  18. High-spin states with the (p,π) reaction

    NASA Astrophysics Data System (ADS)

    Jacobs, W. W.

    1986-06-01

    Data from systematic studies of the A(p,π-)A+1 reaction leading to discrete and continuous nuclear final states have revealed both expected and unexpected signatures of the dominance of a two nucleon mechanism (TNM—NN → NNπ inside the nucleus) in near-threshold pion production. A distinctive manifestation of this dominance is the systematic and selective excitation by TNM (p,π-) of high-spin 2p-1h states on target nuclei throughout the periodic table, representing a universal and fundamental response of the nucleus to this high momentum transfer probe. Questions as to whether TNM is also dominant in A(p,π+)A+1, what are the corresponding implications for high-spin excitations, and to what extent is the overall observed (p,π+) behavior related to what is known about fundamental NN → NNπ+ processes are addressed through investigation of the 13C(p,π±) reactions populating the mirror nuclei 14C and 14O. In the course of these studies, comparative (p,π+) vs. (p,π-) data were used to suggest a Jπ=5- assignment for a previously unobserved state near EX=15 MeV in the (p,π+) spectra. Also of interest is a strong and sharp (p,π+) transition at relatively high excitation (EX ≂ 23.2 MeV) in 14C. While we find most observed features in the (p,π±) spectra are consistent with TNM expectations, one possible explanation for the latter state's unique behavior involves the anomalous enhancement of normally weak free NN → NNπ isospin channels when immersed in the nuclear medium.

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

    SciTech Connect

    Broda, R.; Wrzesinski, J.; Pawlat, T.

    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.

  20. Observations of high spin states in {sup 179}Au

    SciTech Connect

    Carpenter, M.P.; Ahmad, I.; Blumenthal, D.J.

    1995-08-01

    As part of a current study on the properties of the {pi} i{sub 13/2} intruder state in the A = 175-190 region, we conducted an experiment at ATLAS to observe high spin states in {sup 179}Au utilizing the reaction {sup 144}Sm({sup 40}Ar,p4n) at beam energies of 207 MeV and 215 MeV. To aid in the identification of {sup 179}Au, and to filter out the large amount of events from fission by-products, the Fragment Mass Analyzer was utilized in conjunction with ten Compton-suppression germanium detectors. In total, 11 x 10{sup 6} {gamma}-{gamma} and 4 x 10{sup 5} {gamma}-recoil events were collected. By comparing {gamma}-rays in coincidence with an A = 179 recoil mass gate and {gamma}-rays in coincidence with Au K{alpha} and K{beta} X-rays, ten {gamma}-rays were identified as belonging to {sup 179}Au. Based on {gamma}-ray coincidence relationships and on comparisons with neighboring odd-A Au nuclei, we constructed a tentative level scheme and assigned a rotational-like sequence to the {pi} i{sub 13/2} proton configuration.

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

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Study of High Spin States in ^192Au

    NASA Astrophysics Data System (ADS)

    Gurdal, G.; Beausang, C. W.; Balabanski, D.; Novak, J. R.; Hecht, A. A.; Caprio, M.; Cooper, J. R.; Krücken, R.; Casten, R. F.; Zamfir, N. V.; Berant, Z.; Barton, C. J.; Pietralla, N.; Erduran, M. N.; Akkus, B.; Erturk, S.; Yigitoglu, I.; Oktem, Y.; Hartley, D. J.; Gjongolov, M.; Goon, J.

    2001-10-01

    Doubly odd nuclei in the A ~190 mass region are predicted to be good candidates to search for evidence of chiral symmetry breaking. Indeed evidence for a pair of chiral twin bands has recently been reported in ^188Ir [1]. To search for additional examples of this phenomenon we studied the high spin structures in the neighboring nuclei. ^192Au and ^190Ir were populated using the ^186W(^11B,5n) and ^186W(^11B,α3n) reactions at a beam energy of 68 MeV. Gamma-ray coincidence measurements were performed using the YRAST Ball at WNSL, Yale University. Analysis is in progress and preliminary results will be presented. This work is supported by the U.S. D.O.E under Grant Numbers DE-FG02-91ER-40609, DE-FG02-88ER-40417, DE-FG02-96ER-40983 and by the DFG under Grant Number Pi 393/1-1 and by the Research Fund of The University of Istanbul under Grant Number 1582/19032001 . [1] D. Balabanski et al, to be published.

  4. High-spin states in 29Al and 27Mg

    NASA Astrophysics Data System (ADS)

    Dungan, R.; Tabor, S. L.; Lubna, R. S.; Volya, A.; Tripathi, Vandana; Abromeit, B.; Caussyn, D. D.; Kravvaris, K.; Tai, P.-L.

    2016-12-01

    The structure of 29Al and 27Mg was investigated using the reactions 18O(14C,p 2 n ) and 18O(14C,α n ) at 40 MeV. The charged particles were detected and identified with a Δ E -E telescope in coincidence with γ radiation detected in the Florida State University Compton suppressed γ detector array. The level and decay schemes of both nuclei have been expanded at higher spins and excitation energies. The positive-parity states up to 3.5-4.5 MeV agree well with shell model calculations using the USDA interaction. The negative-parity states in 27Mg are reproduced relatively well by one-particle-one-hole calculations with the WBP-a interaction. Three 27Mg states unbound by 0.4-1.4 MeV to neutron decay were observed to decay radiatively. One of these states had been previously observed to γ decay in a (d ,p γ ) experiment along with a surprising 16 other neutron unbound states. The competition between neutron and γ decay in these states is discussed in terms of angular momentum barriers and spectroscopic factors.

  5. Shape evolution at high spin states in Kr and Br isotopes

    SciTech Connect

    Trivedi, T.; Palit, R.; Naik, Z.; Jain, H. C.; Negi, D.; Kumar, R.; Singh, R. P.; Muralithar, S.; Pancholi, S. C.; Bhowmik, R. K.; Yang, Y.-C.; Sun, Y.; Sheikh, J. A.; Raja, M. K.; Kumar, S.; Choudhury, D.; Jain, A. K.; Mehrotra, I.

    2014-08-14

    The high spin states in A = 75, Kr and Br isotopes have been populated via fusion-evaporation reaction at an incident beam energy of 90 MeV. The de-exciting γ-rays were detected utilizing the Indian National Gamma Array (INGA). Lifetime of these excited high spin states were determined by Doppler-shift attenuation method. Experimental results obtained from lifetime measurement are interpreted in the frame work of projected shell-model to get better insight into the evolution of collectivity. Comparison of the calculations of the model with transitional quadrupole moments Q{sub t} of the positive and negative parity bands firmly established their configurations.

  6. IBFA description of high-spin positive-parity states in Rh isotopes

    NASA Astrophysics Data System (ADS)

    Bucurescu, D.; Cǎta, G.; Cutoiu, D.; Constantinescu, G.; Ivascu, M.; Zamfir, N. V.

    1985-09-01

    Properties of the odd-mass Rh isotopes are investigated in the framework of the interacting boson-fermion approximation (IBFA) model in which the odd proton movea in the 1 g{9}/{2} and 2 d{5}/{2} orbitals. Lifetimes of some high-spin positive-parity states in 99Rh obtained by the recoil-distance method with the 88Sr( 14N, 3n) reaction are also reported. Calculated excitation energies and electromagnetic properties of the high-spin positive-parity states are compared with experiment and an acceptable agreement is obtained.

  7. Nuclear structure and high-spin states of 137Pr

    NASA Astrophysics Data System (ADS)

    Dragulescu, E.; Ivascu, M.; Petrache, C.; Popescu, D.; Semenescu, G.; Gurgu, I.; Ionescu-Bujor, M.; Iordachescu, A.; Pascovici, G.; Meyer, R. A.; Lopac, V.; Brant, S.; Paar, V.; Vorkapić, D.; Vretenar, D.

    1992-10-01

    Levels in 137Pr were populated in the 126Te( 14N, 3n) and 122Sn( 19F, 4n) reactions and the subsequent radiation was studied using in-beam γ-ray spectroscopy methods including γ-ray excitation-function, angular-distribution, γγ( t) coincidence and γ( t) measurements. A level scheme with new states up to spin {35}/{2} belonging to 137Pr is given. The lifetime of the {11}/{21} state at 563.4 keV has been determined as T {1}/{2} = 2.66±0.07 μ s. The calculation of low-lying levels in 137Pr performed in IBFM has been compared to experimental data.

  8. Natural reference for nuclear high-spin states

    SciTech Connect

    Rowley, Neil; Ollier, James; Simpson, John

    2009-08-15

    We suggest two new representations of the data on rotational nuclei. The first is reference-free and the second arises from a natural reference related to the variable moment of inertia model parameters of the ground-state band of the system. As such, neither representation contains any free parameters. By defining a 'configuration spin' we show how a new ground-state band reference can be applied. Its use allows a complete description of the changes associated with the first, and higher, band crossings. We apply these new representations to discuss the nature of the first band crossing along even-even isotopic chains in the erbium and osmium isotopes and to odd-even nuclei in the vicinity of {sup 158}Er.

  9. The Excitation of High Spin States with Quasielastic and Deep Inelastic Reactions.

    NASA Astrophysics Data System (ADS)

    Knott, Clinton Neal

    1988-12-01

    The feasibility of populating high spin states using reactions induced by a 220 MeV ^{22 }Ne beam on a ^{170} Er target was studied. The experiment was carried out using a multidetector array for high resolution gamma-ray spectroscopy, a 14 element sum multiplicity spectrometer and six DeltaE-E particle telescopes. Detailed information was obtained concerning the reaction mechanisms associated with various reaction channels. Deep inelastic collisions are shown to be a promising tool for high spin spectroscopy in regions of the chart of nuclides which are not accessible by other reactions.

  10. Population of high spin states by quasi-elastic and deep inelastic collisions

    NASA Astrophysics Data System (ADS)

    Takai, H.; Knott, C. N.; Winchell, D. F.; Saladin, J. X.; Kaplan, M. S.; de Faro, L.; Aryaeinejad, R.; Blue, R. A.; Ronningen, R. M.; Morrissey, D. J.; Lee, I. Y.; Dietzsch, O.

    1988-09-01

    The feasibility of populating high spin states using reactions induced by a 10 MeV/nucleon 22Ne beam on 170Er was studied. The experiment was carried out using a multidetector array for high resolution γ-ray spectroscopy, a 14 element sum-multiplicity spectrometer and six ΔE-E telescopes. Detailed information was obtained concerning the reaction mechanisms associated with various reaction channels. Deep inelastic collisions are shown to be a promising tool for high spin spectroscopy in regions of the chart of nuclides which are not accessible by other reactions.

  11. The excitation of high spin states with quasi-elastic and deep inelastic reactions

    SciTech Connect

    Knott, C.N.

    1988-01-01

    The feasibility of populating high spin states using reactions induced by a 220 MeV {sup 22}Ne beam on a {sup 170}Er target was studied. The experiment was carried out using a multidetector array for high resolution {gamma}-ray spectroscopy, a 14 element sum multiplicity spectrometer and six {Delta}E-E particle telescopes. Detailed information was obtained concerning the reaction mechanisms associated with various reaction channels. Deep inelastic collisions are shown to be a promising tool for high spin spectroscopy in regions of the chart of nuclides which are not accessible by other reactions.

  12. Population of high spin states by quasi-elastic and deep inelastic collisions

    SciTech Connect

    Takai, H.; Knott, C.N.; Winchell, D.F.; Saladin, J.X.; Kaplan, M.S.; de Faro, L.; Aryaeinejad, R.; Blue, R.A.; Ronningen, R.M.; Morrissey, D.J.; and others

    1988-09-01

    The feasibility of populating high spin states using reactions induced by a 10 MeV/nucleon /sup 22/Ne beam on /sup 170/Er was studied. The experiment was carried out using a multidetector array for high resolution ..gamma..-ray spectroscopy, a 14 element sum-multiplicity spectrometer and six ..delta..E-E telescopes. Detailed information was obtained concerning the reaction mechanisms associated with various reaction channels. Deep inelastic collisions are shown to be a promising tool for high spin spectroscopy in regions of the chart of nuclides which are not accessible by other reactions.

  13. High-spin states and a new band based on the isomeric state in 152Nd

    NASA Astrophysics Data System (ADS)

    Yeoh, E. Y.; Zhu, S. J.; Hamilton, J. H.; Ramayya, A. V.; Yang, Y. C.; Sun, Y.; Hwang, J. K.; Liu, S. H.; Wang, J. G.; Luo, Y. X.; Rasmussen, J. O.; Lee, I. Y.; Ding, H. B.; Li, K.; Gu, L.; Xu, Q.; Xiao, Z. G.; Ma, W. C.

    2010-08-01

    High-spin states of the neutron-rich 152Nd nucleus have been reinvestigated by measuring the prompt γ -rays in the spontaneous fission of 252Cf . 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 π5/2-[532] ⊗ π9/2+[404] and neutron ν3/2-[521] ⊗ ν5/2+[642] two-quasiparticles configurations, respectively.

  14. High-spin states with seniority v=4, 5, and 6 in 119-126Sn

    NASA Astrophysics Data System (ADS)

    Astier, A.; Porquet, M.-G.; Theisen, Ch.; Verney, D.; Deloncle, I.; Houry, M.; Lucas, R.; Azaiez, F.; Barreau, G.; Curien, D.; Dorvaux, O.; Duchêne, G.; Gall, B. J. P.; Redon, N.; Rousseau, M.; Stézowski, O.

    2012-05-01

    The 119-126Sn nuclei have been produced as fission fragments in two reactions induced by heavy ions: 12C+238U at a bombarding energy of 90 MeV and 18O+208Pb at 85 MeV. Their level schemes have been built from γ rays detected using the Euroball array. High-spin states located above the long-lived isomeric states of the even- and odd-A 120-126Sn nuclei have been identified. Moreover, isomeric states lying around 4.5 MeV have been established in 120,122,124,126Sn from the delayed coincidences between the fission fragment detector SAPhIR and the Euroball array. The states located above 3 MeV excitation energy are ascribed to several broken pairs of neutrons occupying the νh11/2 orbit. The maximum value of angular momentum available in such a high-j shell, i.e., for midoccupation and the breaking of the three neutron pairs, has been identified. This process is observed for the first time in spherical nuclei.

  15. In-beam spectroscopy of medium- and high-spin states in 133Ce

    NASA Astrophysics Data System (ADS)

    Ayangeakaa, A. D.; Garg, U.; Petrache, C. M.; Guo, S.; Zhao, P. W.; Matta, J. T.; Nayak, B. K.; Patel, D.; Janssens, R. V. F.; Carpenter, M. P.; Chiara, C. J.; Kondev, F. G.; Lauritsen, T.; Seweryniak, D.; Zhu, S.; Ghugre, S. S.; Palit, R.

    2016-05-01

    Medium and high-spin states in 133Ce were investigated using the 116Cd(22Ne, 5 n ) reaction and the Gammasphere array. The level scheme was extended up to an excitation energy of ˜22.8 MeV and spin 93/2 ℏ . Eleven bands of quadrupole transitions and two new dipole bands are identified. The connections to low-lying states of the previously known, high-spin triaxial bands were firmly established, thus fixing the excitation energy and, in many cases, the spin parity of the levels. Based on comparisons with cranked Nilsson-Strutinsky calculations and tilted axis cranking covariant density functional theory, it is shown that all observed bands are characterized by pronounced triaxiality. Competing multiquasiparticle configurations are found to contribute to a rich variety of collective phenomena in this nucleus.

  16. Delayed autoionization of recoil ions by the decay of high-spin isomeric states

    NASA Astrophysics Data System (ADS)

    Maidikov, V. Z.

    1985-12-01

    The time dependence of the ionization for isotopically different heavy ion fusion recoil ions has been observed. Delayed nuclear-induced autoionization of recoil ions caused by the decay of high-spin nuclear isomeric states by internal conversion was established. Internal conversion in isolated recoil atoms results in a drastic rearrangement in the atomic cloud with a loss of a great number of orbital electrons. Possibilities for the use of the observed phenomena in atomic and nuclear physics are discussed.

  17. High-spin states and shell structure of the odd-odd nucleus {sup 90}Nb

    SciTech Connect

    Cui, X.Z.; Zhang, Z.L.; Meng, R.; Yang, C.X.; Zhu, L.H.; Wu, X.G.; Wang, Z.M.; He, C.Y.; Li, G.S.; Wen, S.X.; Ma, R.G.; Liu, Y.; Luo, P.; Zheng, Y.; Ndontchueng, M.M.; Huo, J.D.

    2005-10-01

    The high-spin states of the odd-odd nucleus {sup 90}Nb have been investigated with in-beam {gamma}-spectroscopic techniques via the {sup 76}Ge({sup 19}F,5n){sup 90}Nb reaction at a beam energy of 80 MeV. {gamma}-{gamma} coincidences were measured using a {gamma}-ray detector array. Twenty new {gamma} rays have been assigned to {sup 90}Nb and the level scheme has been extended up to an excitation energy of 8.095 MeV at spin 18({Dirac_h}/2{pi}). The level structure of {sup 90}Nb at high spin states has been well reproduced using semiempirical shell-model calculations in the model space {pi}(1p{sub 1/2},0f{sub 5/2},0g{sub 9/2}){nu}(0g{sub 9/2}). The results show that the excitation of protons plays an important role in generating the high-spin states of {sup 90}Nb.

  18. High spin isomer beam line at RIKEN

    SciTech Connect

    Kishida, T.; Ideguchi, E.; Wu, H.Y.

    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.

  19. Isospin Symmetry at High Spin Studied via Nucleon Knockout from Isomeric States.

    PubMed

    Milne, S A; Bentley, M A; Simpson, E C; Baugher, T; Bazin, D; Berryman, J S; Bruce, A M; Davies, P J; Diget, C Aa; Gade, A; Henry, T W; Iwasaki, H; Lemasson, A; Lenzi, S M; McDaniel, S; Napoli, D R; Nichols, A J; Ratkiewicz, A; Scruton, L; Stroberg, S R; Tostevin, J A; Weisshaar, D; Wimmer, K; Winkler, R

    2016-08-19

    One-neutron knockout reactions have been performed on a beam of radioactive ^{53}Co in a high-spin isomeric state. The analysis is shown to yield a highly selective population of high-spin states in an exotic nucleus with a significant cross section, and hence represents a technique that is applicable to the planned new generation of fragmentation-based radioactive beam facilities. Additionally, the relative cross sections among the excited states can be predicted to a high level of accuracy when reliable shell-model input is available. The work has resulted in a new level scheme, up to the 11^{+} band-termination state, of the proton-rich nucleus ^{52}Co (Z=27, N=25). This has in turn enabled a study of mirror energy differences in the A=52 odd-odd mirror nuclei, interpreted in terms of isospin-nonconserving (INC) forces in nuclei. The analysis demonstrates the importance of using a full set of J-dependent INC terms to explain the experimental observations.

  20. Isospin Symmetry at High Spin Studied via Nucleon Knockout from Isomeric States

    NASA Astrophysics Data System (ADS)

    Milne, S. A.; Bentley, M. A.; Simpson, E. C.; Baugher, T.; Bazin, D.; Berryman, J. S.; Bruce, A. M.; Davies, P. J.; Diget, C. Aa.; Gade, A.; Henry, T. W.; Iwasaki, H.; Lemasson, A.; Lenzi, S. M.; McDaniel, S.; Napoli, D. R.; Nichols, A. J.; Ratkiewicz, A.; Scruton, L.; Stroberg, S. R.; Tostevin, J. A.; Weisshaar, D.; Wimmer, K.; Winkler, R.

    2016-08-01

    One-neutron knockout reactions have been performed on a beam of radioactive 53Co in a high-spin isomeric state. The analysis is shown to yield a highly selective population of high-spin states in an exotic nucleus with a significant cross section, and hence represents a technique that is applicable to the planned new generation of fragmentation-based radioactive beam facilities. Additionally, the relative cross sections among the excited states can be predicted to a high level of accuracy when reliable shell-model input is available. The work has resulted in a new level scheme, up to the 1 1+ band-termination state, of the proton-rich nucleus 52Co (Z =27 , N =25 ). This has in turn enabled a study of mirror energy differences in the A =52 odd-odd mirror nuclei, interpreted in terms of isospin-nonconserving (INC) forces in nuclei. The analysis demonstrates the importance of using a full set of J -dependent INC terms to explain the experimental observations.

  1. High-Spin States in PALLADIUM-107, PALLADIUM-108 and SILVER-109.

    NASA Astrophysics Data System (ADS)

    Pohl, Kenneth R.

    1995-01-01

    High-spin states in ^{107,108 }Pd and ^{109}Ag have been studied by charged-particle-gamma , gamma-gamma , and charged-particle-gamma -gamma coincidence measurements of heavy-ion fusion-evaporation reactions. Charged-particle -gamma measurements of gamma -ray spectra, angular distributions, and excitation functions were performed using an ^{18 }O beam with an enriched ^{96 }Zr target at beam energies of 56, 63, 72, and 80 MeV. Background measurements were performed using a ^{rm nat}Zr target. Charged -particle-gamma-gamma measurements using the same reaction at beam energies of 70 and 60 MeV were used to measure gamma -gamma coincidences, coincidence intensities, and gated angular distributions. A gamma-gamma measurement using the reaction ^{100}Mo( ^{13}C,p3n)^ {109}Ag at E_{BEAM } = 65 MeV was performed to measure a low-energy transition in ^{109}Ag. Partial level schemes of ^{107,108 }Pd and ^{109}Ag were constructed from the gamma- gamma coincidence measurements. These levels schemes significantly extend the known high-spin decay patterns of ^{107}Pd and ^{108}Pd. The ^{109}Ag results represent the first measurement of high-spin states in that nuclide. New collective bands have been discovered in all three nuclides. The principal bands in each exhibit the general property of back-bends corresponding to the rotational alignment of a pair of h_{11over2 } quasi-neutrons. Rotational alignments and Routhians have been compared to predictions of the cranked shell model and total Routhian surface calculations. Transition properties in ^{107}Pd and ^{109}Ag have been compared to predictions of a geometrical model in the context of the cranked shell model.

  2. High-spin states in 136La and possible structure change in the N =79 region

    NASA Astrophysics Data System (ADS)

    Nishibata, H.; Leguillon, R.; Odahara, A.; Shimoda, T.; Petrache, C. M.; Ito, Y.; Takatsu, J.; Tajiri, K.; Hamatani, N.; Yokoyama, R.; Ideguchi, E.; Watanabe, H.; Wakabayashi, Y.; Yoshinaga, K.; Suzuki, T.; Nishimura, S.; Beaumel, D.; Lehaut, G.; Guinet, D.; Desesquelles, P.; Curien, D.; Higashiyama, K.; Yoshinaga, N.

    2015-05-01

    High-spin states in the odd-odd nucleus 136La, which is located close to the β -stability line, have been investigated in the radioactive-beam-induced fusion-evaporation reaction 124Sn(17N,5 n ). The use of the radioactive beam enabled a highly sensitive and successful search for a new isomer [14+,T1 /2=187 (27 ) ns] in 136La. In the A =130 -140 mass region, no such long-lived isomer has been observed at high spin in odd-odd nuclei. The 136La level scheme was revised, incorporating the 14+ isomer and six new levels. The results were compared with pair-truncated shell model (PTSM) calculations which successfully explain the level structure of the π h11 /2⊗ν h11/2 -1 bands in 132La and 134La. The isomerism of the 14+ state was investigated also by a collective model, the cranked Nilsson-Strutinsky (CNS) model, which explains various high-spin structures in the medium-heavy mass region. It is suggested that a new type of collective structure is induced in the PTSM model by the increase of the number of π g7 /2 pairs, and/or in the CNS model by the configuration change associated with the shape change in 136La.

  3. High-Spin States of {sup 84,85}Br: Mapping the Proton Sub-Shells towards {sup 78}Ni

    SciTech Connect

    Astier, A.; Porquet, M.-G.; Deloncle, I.; Venkova, Ts.; Azaiez, F.; Buta, A.; Curien, D.; Dorvaux, O.; Duchene, G.; Gall, B. J. P.; Khalfallah, F.; Piqueras, I.; Rousseau, M.; Meyer, M.; Redon, N.; Stezowski, O.; Lucas, R.

    2008-05-12

    The {sup 84,85}Br nuclei have been produced as fission fragments in the fusion reaction {sup 18}O+{sup 208}Pb at 85 MeV bombarding energy and studied with the Euroball IV array. The high-spin states of the odd-odd {sup 84}Br nucleus have been identified for the first time. From angular correlation analysis, spin values have been assigned to most of the {sup 85}Br excited states up to 4 MeV. All observed states in {sup 84,85}Br can be described by various proton excitations involving at least the two sub-shells ({pi}f{sub 5/2} and {pi}p{sub 3/2}) located just above the Z = 28 shell closure.

  4. New high-spin stretched states in 208Pb observed by the (p,p') reaction

    NASA Astrophysics Data System (ADS)

    Fujita, Y.; Yanagihara, T.; Fujiwara, M.; Katayama, I.; Hosono, K.; Morinobu, S.; Yamazaki, T.; Hayakawa, S. I.; Katori, K.; Muto, K.; Ikegami, H.

    1990-09-01

    High-spin states have been newly observed at 7.83 MeV and 8.37 MeV in 208Pb by the (p,p') reaction at Ep = 80 MeV. The analysis of the angular distributions peaked at large angles and the results of shell-model calculations suggest that these are the stretched states with neutron configurations v(i {11}/{2},h {9}/{2}-1) 10- and v(j {15}/{2},h {9}/{2}-1) 12+, respectively. Candidates for the v(j {15}/{2},f {7}/{2}-1), 11 + and v(g {7}/{2},i {13}/{2}-) , 10 + states have also been observed at 7.46 MeV and 7.66 MeV, respectively.

  5. Average magnetic moments of pre-yrast high spin states in {sup 166,165}Hf

    SciTech Connect

    Weissman, L.; Hass, M.; Broude, C.

    1996-01-01

    The average magnetic moments of high spin states in Hf isotopes were determined in a transient field measurement at the 14 MV Koffler accelerator of the Weizmann Institute. The reaction {sup 130}Te({sup 40}Ca,{ital xn}){sup 166,165}Hf at beam energies from 167 to 182.5 MeV was used to populate different high spin regions and provide the recoiling Hf nuclei with sufficient velocity to traverse the 2.9 mg/cm{sup 2} Gd ferromagnetic layer. Standard double ratios and angular distributions for various low level transitions were measured to determine precession angles. These carry information regarding the average {ital g} factor of unobservable transitions at medium excitation. To obtain a more quantitative analysis regarding the time-decay history of the {gamma} cascade, Monte Carlo simulations of the cascade were carried out. The significance of the results for understanding the single particle nature of these pre-yrast levels is discussed. {copyright} {ital 1996 The American Physical Society.}

  6. Repulsively bound exciton-biexciton states in high-spin fermions in optical lattices

    SciTech Connect

    Argueelles, A.; Santos, L.

    2011-03-15

    We show that the interplay between spin-changing collisions and quadratic Zeeman coupling provides a mechanism for the formation of repulsively bound composites in high-spin fermions, which we illustrate by considering spin flips in an initially polarized hard-core one-dimensional Mott insulator of spin-3/2 fermions. We show that after the flips the dynamics is characterized by the creation of two types of exciton-biexciton composites. We analyze the conditions for the existence of these bound states and discuss their intriguing properties. In particular we show that the effective mass and stability of the composites depends nontrivially on spin-changing collisions, on the quadratic Zeeman effect, and on the initial exciton localization. Finally, we show that the composites may remain stable against inelastic collisions, opening the possibility of interesting quantum composite phases.

  7. High-spin magnetic states in the two-orbital Hubbard model on a tetrahedron.

    PubMed

    Romano, Alfonso; Noce, Canio; Amendola, Maria Emilia

    2008-11-19

    We present a study of the two-orbital degenerate Hubbard model in which the exact numerical solution on a regular tetrahedron is obtained via suitable implementation of the symmetries generated by the spin, the pairing and the orbital pseudospin operators. In particular, we show that a large variety of high-spin magnetic ground states can develop away from half filling, depending on the values of the electron density and the parameters of the model. As the tetrahedron is the simplest finite-size cluster where hopping processes connect all pairs of sites with constant probability, the study is extended by providing the exact analytical solution of the model on an infinite lattice in the unconstrained hopping limit.

  8. High-spin states in the N=50 nucleus ^87Rb

    NASA Astrophysics Data System (ADS)

    Fotiades, N.; Cizewski, J. A.; Krücken, R.; Clark, R. M.; Fallon, P.; Lee, I. Y.; Macchiavelli, A. O.; Becker, J. A.; Bernstein, L. A.; McNabb, D. P.; Younes, W.

    2001-10-01

    High-spin states in ^87Rb have been studied following the fission of two compound nuclei (^199Tl and ^197Pb) formed in different fusion-evaporation reactions. The Gammasphere array at LBNL was used to detect γ-ray coincidences. The level scheme has been extended above the previously known 1578 keV, 9/2^+ isomer by observation of many states up to ~7.2 MeV excitation energy. Coupling of the odd g_9/2 proton to the yrast states in the ^86Kr core accounts for the first excited states observed above the 9/2^+ isomer. The level scheme of ^87Rb is also compared to excitations in ^85Kr and the ^89Y isotone. This work has been supported in part by the U.S. Department of Energy under Contracts No. W-7405-ENG-36 (LANL), FG02-91ER-40609 (Yale), W-7405-ENG-48 (LLNL) and AC03-76SF00098 (LBNL) and by the National Science Foundation (Rutgers).

  9. High spin states in {sup 151,153}Pr, {sup 157}Sm, and {sup 93}Kr

    SciTech Connect

    Hwang, J. K.; Ramayya, A. V.; Hamilton, J. H.; Liu, S. H.; Brewer, N. T.; Luo, Y. X.; Rasmussen, J. O.; Zhu, S. J.; Donangelo, R.

    2010-09-15

    High spin states are observed for the first time in the neutron-rich nuclei {sup 151,153}Pr, {sup 157}Sm, and {sup 93}Kr from the spontaneous fission of {sup 252}Cf. Twenty new transitions in {sup 151}Pr, twelve in {sup 153}Pr, five in {sup 157}Sm, and four in {sup 93}Kr were identified by using x-ray(Pr/Sm)-{gamma}-{gamma} and {gamma}-{gamma}-{gamma} triple coincidences. From the measured total internal conversion coefficients {alpha}{sub T} of four low-energy transitions in {sup 151,153}Pr, we determine that two bands in each nucleus have opposite parity. The interlacing E1 transitions between the bands suggest a form of parity doubling in {sup 151,153}Pr. New bands in {sup 157}Sm and {sup 93}Kr are reported. The half-life of the 354.8 keV state in {sup 93}Kr is measured to be 10(2) ns.

  10. In-beam studies of high-spin states of actinide nuclei

    SciTech Connect

    Stoyer, M.A. . Nuclear Science Div. California Univ., Berkeley, CA . Dept. of Chemistry)

    1990-11-15

    High-spin states in the actinides have been studied using Coulomb- excitation, inelastic excitation reactions, and one-neutron transfer reactions. Experimental data are presented for states in {sup 232}U, {sup 233}U, {sup 234}U, {sup 235}U, {sup 238}Pu and {sup 239}Pu from a variety of reactions. Energy levels, moments-of-inertia, aligned angular momentum, Routhians, gamma-ray intensities, and cross-sections are presented for most cases. Additional spectroscopic information (magnetic moments, M{sub 1}/E{sub 2} mixing ratios, and g-factors) is presented for {sup 233}U. One- and two-neutron transfer reaction mechanisms and the possibility of band crossings (backbending) are discussed. A discussion of odd-A band fitting and Cranking calculations is presented to aid in the interpretation of rotational energy levels and alignment. In addition, several theoretical calculations of rotational populations for inelastic excitation and neutron transfer are compared to the data. Intratheory comparisons between the Sudden Approximation, Semi-Classical, and Alder-Winther-DeBoer methods are made. In connection with the theory development, the possible signature for the nuclear SQUID effect is discussed. 98 refs., 61 figs., 21 tabs.

  11. Dipole bands in high spin states of {sub 57}{sup 135}La{sub 78}

    SciTech Connect

    Garg, Ritika; Kumar, S.; Saxena, Mansi; Goyal, Savi; Siwal, Davinder; Verma, S.; Mandal, S.; Palit, R.; Saha, Sudipta; Sethi, J.; Sharma, Sushil K.; Trivedi, T.; Jadav, S. K.; Donthi, R.; Naidu, B. S.

    2014-08-14

    High spin states of {sup 135}La have been investigated using the reaction {sup 128}Te({sup 11}B,4n){sup 135}La at a beam energy of 50.5 MeV. Two negative parity dipole bands (ΔI = 1) have been established. Crossover E2 transitions have been observed for the first time in one of the dipole bands. For the Tilted Axis Cranking (TAC) calculations, a three-quasiparticle (3qp) configuration π(h{sub 11/2}){sup 1}⊗ν(h{sub 11/2}){sup −2} and a five-quasiparticle (5qp) configuration π(h{sub 11/2}){sup 1}(g{sub 7/2}/d{sub 5/2}){sup 2}⊗ν(h{sub 11/2}){sup −2} have been taken for the two negative parity dipole bands. The comparison of experimental observables with TAC calculations supports the configuration assignments for both the dipole bands.

  12. High-spin states and level structure in {sup 84}Rb

    SciTech Connect

    Shen Shuifa; Han Guangbing; Wen Shuxian; Gu Jianzhong; Wu Xiaoguang; Zhu Lihua; He Chuangye; Li Guangsheng; Yu Beibei; Pan Feng; Zhu Jianyu; Draayer, J. P.; Wen Tingdun; Yan, Yupeng

    2010-07-15

    High-spin states in {sup 84}Rb have been studied by using the {sup 70}Zn({sup 18}O,p3n){sup 84}Rb reaction at beam energy of 75 MeV. The gamma-gamma coincidence, excitation function, and ratios for directional correlation of oriented states were determined. A new level scheme was established in which the positive- and negative-parity bands have been extended up to 17{sup +} and 17{sup -} with an excitation energy of about 7 MeV. The signature splitting and signature inversion of the positive-parity yrast band were observed. To understand the microscopic origin of the signature inversion in the yrast positive-parity bands of doubly odd Rb nuclei, as an example, we performed calculations using the projected shell model to describe the energy spectra in {sup 84}Rb. It can be seen that the main features are reproduced in the calculations. This analysis shows that the signature splitting, especially its inversion, can be reproduced by varying only the gamma deformation with increasing spin. To research the deformation of {sup 84}Rb carefully, we calculate the total Routhian surfaces of positive-parity yrast states by the cranking shell model formalism. In addition, the results of theoretical calculations about the negative-parity yrast band in {sup 84}Rb with configuration pi(p{sub 3/2},f{sub 5/2}) x nug{sub 9/2} are compared with experimental data, and a band diagram calculated for this band is also shown to extract physics from the numerical results.

  13. Reduction of collectivity at very high spins in 134Nd: Expanding the projected-shell-model basis up to 10-quasiparticle states

    NASA Astrophysics Data System (ADS)

    Wang, Long-Jun; Sun, Yang; Mizusaki, Takahiro; Oi, Makito; Ghorui, Surja K.

    2016-03-01

    Background: The recently started physics campaign with the new generation of γ -ray spectrometers, "GRETINA" and "AGATA," will possibly produce many high-quality γ rays from very fast-rotating nuclei. Microscopic models are needed to understand these states. Purpose: It is a theoretical challenge to describe high-spin states in a shell-model framework by the concept of configuration mixing. To meet the current needs, one should overcome the present limitations and vigorously extend the quasiparticle (qp) basis of the projected shell model (PSM). Method: With the help of the recently proposed Pfaffian formulas, we apply the new algorithm and develop a new PSM code that extends the configuration space to include up to 10-qp states. The much-enlarged multi-qp space enables us to investigate the evolutional properties at very high spins in fast-rotating nuclei. Results: We take 134Nd as an example to demonstrate that the known experimental yrast and the several negative-parity side bands in this nucleus could be well described by the calculation. The variations in moment of inertia with spin are reproduced and explained in terms of successive band crossings among the 2-qp, 4-qp, 6-qp, 8-qp, and 10-qp states. Moreover, the electric quadrupole transitions in these bands are studied. Conclusions: A pronounced decrease in the high-spin B (E 2 ) of 134Nd is predicted, which suggests reduction of collectivity at very high spins because of increased level density and complex band mixing. The possibility for a potential application of the present development in the study of highly excited states in warm nuclei is mentioned.

  14. Equation of State and Hyperfine Parameters of High-Spin Bridgmanite in the Earth's Lower Mantle

    NASA Astrophysics Data System (ADS)

    Mao, Z.; Wang, F.; Lin, J. F.; Fu, S.; Yang, J.; Wu, X.; Okuchi, T.; Tomioka, N.; Prakapenka, V.; Xiao, Y.; Chow, P.

    2016-12-01

    Bridgmanite [(Mg,Fe)(Fe,Al,Si)O3] is one of the most abundant minerals in the Earth's lower mantle. Studies on the combined effect of Fe and Al on the structure and equation of state parameters are important to understand the composition of the lower mantle. In particular, Fe in lower-mantle bridgmanite has been reported to undergo spin pairing transitions which could affect a number of physical properties of bridgmanite. Although high-pressure theoretical and experimental studies have been in agreement for the spin state of Fe3+ in the lower-mantle bridgmanite, the spin state of A-site Fe2+ remains controversial. In this study, we have performed high-pressure synchrotron X-ray diffraction (XRD) and Mössbauer spectroscopy (SMS) measurements on two single-crystal bridgmanite samples (Mg0.95Fe0.06Si0.99O3 and Mg0.89Fe0.12Al0.11Si0.89O3) up to 130 GPa and 300 K to investigate the combined effect of Fe and Al on the structure and equation of state parameters of bridgmanite. The SMS results have shown that Fe2+ and Fe3+ in both our Al-free and Al-bearing bridgmanite are predominantly located in the A-site at lower-mantle pressures. The A-site Fe3+ in both compositions remains in the HS state at lower-mantle pressures. In particular, we observed a drastic increase in QS of the A-site Fe2+ in Al-free bridgmanite between 13 and 32 GPa. Together with recent synchrotron X-ray emission spectroscopy results, we support the notion that the occurrence of the extremely high QS component of approximately 4 mm/s in Al-free bridgmanite is due to the enhanced lattice distortion of the high-spin A-site Fe2+. Combining the SMS results with high quality XRD data allows to correlate the the extremely high-quadrupole parameter of the A-site Fe2+ with the anomalous variations in the bond length, tilting angle, and shear strain in the local octahedra of Al-free bridgmanite. The high-quality XRD results also provide crucial constraints on the effect Fe and Al on the equation of state

  15. Polarization measurements and high-spin states in 8638Sr48

    NASA Astrophysics Data System (ADS)

    Kumar, Naveen; Kumar, Suresh; Kumar, V.; Mandal, S. K.; Palit, R.; Saha, S.; Sethi, J.; Trivedi, T.; Pancholi, S. C.; Srivastava, P. C.

    2016-11-01

    The high-spin states in 86Sr nucleus were populated using the 76Ge(13C, 3n) reaction at a beam energy of 45 MeV. The γ-γ and γ-γ-γ coincidence measurements were used to establish the level scheme up to 10.9 MeV excitation energy and spin Iπ =19+. In our preliminary results reported earlier, a positive-parity dipole (ΔI = 1) band based on the 6878-keV level having M1 γ-ray transitions was identified. In the present work, the γ-rays and their sequence have been established for this band. The band may have a magnetic rotational character. The spin-parity of the levels were assigned by measuring the Directional Correlations of the Oriented (DCO) nuclei and the polarization asymmetry. The polarization measurements were performed for the first time for the γ-ray transitions in this nucleus. The experimental band structures were compared with the shell-model calculations using two recent effective interactions, JUN45 and jj44b in the 1p3/2, 0f5/2, 1p1/2, 0g9/2 model space. From the Tilted-Axis Cranking (TAC) calculations, the 4-qp π(g9/2) 2 ⊗ ν(g9/2) - 2 configuration is suggested for the lower-part of the (ΔI = 1) band up to spin Iπ =16+ and the 6-qp π [(g9/2) 2(f5/2) 1(p1/2) 1 ] ⊗ ν(g9/2) - 2 configuration for the upper-part of the band.

  16. Structure of high spin state in proton-rich 74,76,78Kr isotopes: A projected shell model description

    NASA Astrophysics Data System (ADS)

    Liu, YanXin; Yu, ShaoYing; Shen, CaiWan

    2015-01-01

    The N≈ Z nuclei in the mass A˜80 region has been researched because of an abundance of nuclear structure phenomena. The projected shell model (PSM) was adopted to investigate the structure of high spin state in proton-rich 74,76,78Kr isotopes including yrast spectra, moment of inertia, electric quadrupole transitions and the behavior of single particle. The calculated results are in good agreement with available data and the shape coexistence in low-spin is also discussed.

  17. High-spin states in {sup 205}Rn: A new shears band structure?

    SciTech Connect

    Novak, J.R.; Beausang, C.W.; Casten, R.F.; Cata Danil, G.; Cooper, J.R.; Juutinen, S.; Kruecken, R.; Liu, B.; Socci, T.; Thomas, J.T.; Zamfir, N.V.; Zhang, J.; Amzal, N.; Greenlees, P.T.; Cata Danil, G.; Zamfir, N.V.; Cocks, J.F.; Greenlees, P.T.; Helariutta, K.; Jones, P.; Julin, R.; Kankaanpaeae, H.; Kettunen, H.; Kuusiniemi, P.; Leino, M.; Muikku, M.; Savelius, A.; Hannachi, F.; Zamfir, N.V.; Zhang, J.; Frauendorf, S.

    1999-06-01

    The high-spin structure of {sup 205}Rn has been investigated for the first time following the {sup 170}Er({sup 40}Ar,5n) and {sup 197}Au({sup 14}N,6n) reactions at beam energies of 183 MeV and 90{endash}110 MeV, respectively, using the Jurosphere and YRAST Ball arrays. Two new cascades have been identified which dominate the high-spin decay. One of these, consisting of ten stretched M1 transitions with unobserved E2 crossover transitions, is interpreted as a shears structure based on the {nu}i{sub 13/2}{sup {minus}1}{circle_times}{pi}i{sub 13/2}{sup 2} (or {nu}i{sub 13/2}{sup {minus}1}{circle_times}{pi}h{sub 9/2}i{sub 13/2}) configuration. {copyright} {ital 1999} {ital The American Physical Society}

  18. High-spin ferric ions in Saccharomyces cerevisiae vacuoles are reduced to the ferrous state during adenine-precursor detoxification.

    PubMed

    Park, Jinkyu; McCormick, Sean P; Cockrell, Allison L; Chakrabarti, Mrinmoy; Lindahl, Paul A

    2014-06-24

    The majority of Fe in Fe-replete yeast cells is located in vacuoles. These acidic organelles store Fe for use under Fe-deficient conditions and they sequester it from other parts of the cell to avoid Fe-associated toxicity. Vacuolar Fe is predominantly in the form of one or more magnetically isolated nonheme high-spin (NHHS) Fe(III) complexes with polyphosphate-related ligands. Some Fe(III) oxyhydroxide nanoparticles may also be present in these organelles, perhaps in equilibrium with the NHHS Fe(III). Little is known regarding the chemical properties of vacuolar Fe. When grown on adenine-deficient medium (A↓), ADE2Δ strains of yeast such as W303 produce a toxic intermediate in the adenine biosynthetic pathway. This intermediate is conjugated with glutathione and shuttled into the vacuole for detoxification. The iron content of A↓ W303 cells was determined by Mössbauer and EPR spectroscopies. As they transitioned from exponential growth to stationary state, A↓ cells (supplemented with 40 μM Fe(III) citrate) accumulated two major NHHS Fe(II) species as the vacuolar NHHS Fe(III) species declined. This is evidence that vacuoles in A↓ cells are more reducing than those in adenine-sufficient cells. A↓ cells suffered less oxidative stress despite the abundance of NHHS Fe(II) complexes; such species typically promote Fenton chemistry. Most Fe in cells grown for 5 days with extra yeast-nitrogen-base, amino acids and bases in minimal medium was HS Fe(III) with insignificant amounts of nanoparticles. The vacuoles of these cells might be more acidic than normal and can accommodate high concentrations of HS Fe(III) species. Glucose levels and rapamycin (affecting the TOR system) affected cellular Fe content. This study illustrates the sensitivity of cellular Fe to changes in metabolism, redox state and pH. Such effects broaden our understanding of how Fe and overall cellular metabolism are integrated.

  19. High-Spin Ferric Ions in Saccharomyces cerevisiae Vacuoles Are Reduced to the Ferrous State during Adenine-Precursor Detoxification

    PubMed Central

    2015-01-01

    The majority of Fe in Fe-replete yeast cells is located in vacuoles. These acidic organelles store Fe for use under Fe-deficient conditions and they sequester it from other parts of the cell to avoid Fe-associated toxicity. Vacuolar Fe is predominantly in the form of one or more magnetically isolated nonheme high-spin (NHHS) FeIII complexes with polyphosphate-related ligands. Some FeIII oxyhydroxide nanoparticles may also be present in these organelles, perhaps in equilibrium with the NHHS FeIII. Little is known regarding the chemical properties of vacuolar Fe. When grown on adenine-deficient medium (A↓), ADE2Δ strains of yeast such as W303 produce a toxic intermediate in the adenine biosynthetic pathway. This intermediate is conjugated with glutathione and shuttled into the vacuole for detoxification. The iron content of A↓ W303 cells was determined by Mössbauer and EPR spectroscopies. As they transitioned from exponential growth to stationary state, A↓ cells (supplemented with 40 μM FeIII citrate) accumulated two major NHHS FeII species as the vacuolar NHHS FeIII species declined. This is evidence that vacuoles in A↓ cells are more reducing than those in adenine-sufficient cells. A↓ cells suffered less oxidative stress despite the abundance of NHHS FeII complexes; such species typically promote Fenton chemistry. Most Fe in cells grown for 5 days with extra yeast-nitrogen-base, amino acids and bases in minimal medium was HS FeIII with insignificant amounts of nanoparticles. The vacuoles of these cells might be more acidic than normal and can accommodate high concentrations of HS FeIII species. Glucose levels and rapamycin (affecting the TOR system) affected cellular Fe content. This study illustrates the sensitivity of cellular Fe to changes in metabolism, redox state and pH. Such effects broaden our understanding of how Fe and overall cellular metabolism are integrated. PMID:24919141

  20. 34. mu. s isomer at high spin in sup 212 Fr: Evidence for a many-particle octupole coupled state

    SciTech Connect

    Byrne, A.P.; Dracoulis, G.D.; Schiffer, K.J.; Davidson, P.M.; Kibedi, T.; Fabricius, B.; Baxter, A.M.; Stuchbery, A.E. Australian National University, G.P.O. Box 4, Canberra, Australian Capital Territory )

    1990-07-01

    A very high spin isomeric state with {tau}{sub {ital m}}=34(3) {mu}s has been observed at an excitation energy of 8.5 MeV in {sup 212}Fr. The experimental evidence favors an {ital E}3 assignment, with a very large {ital E}3 transition strength, {ital B}({ital E}3)=100(12){times}10{sup 3} {ital e}{sup 2}fm{sup 6}, to one of the {gamma} rays de-exciting the isomer. The observed properties are in very good agreement with the characteristics of a 34{sup +} state predicted by the multiparticle octupole vibration model.

  1. High-Spin States in Transuranium Nuclei 242,244Pu

    NASA Astrophysics Data System (ADS)

    Zhao, Yue; Kang, Xu-Zhong; Shen, Shui-Fa; Yan, Yu-Peng; He, Chuang-Ye; Yan, Shi-Wei

    2012-05-01

    We investigate the structure of yrast bands in the transuranium nuclei 242Pu and 244Pu in the framework of the projected shell model, which is a fully quantum mechanical and microscopic approach. It is found that an appropriate modification of the standard Nilsson spin-orbital parameters in the N = 6 proton shell is necessary to correctly describe the high-spin backbending phenomenon in nucleus 244Pu. In order to test whether this modification is correct, the same modified parameters are used to calculate the yrast band of its neighboring isotope 242Pu. It is found that without this modification, a backbending will occur at spin I = 20, which is not supported by the experimental data.

  2. The integrated spintronic functionalities of an individual high-spin state spin-crossover molecule between graphene nanoribbon electrodes

    NASA Astrophysics Data System (ADS)

    Zhu, L.; Zou, F.; Gao, J. H.; Fu, Y. S.; Gao, G. Y.; Fu, H. H.; Wu, M. H.; Lü, J. T.; Yao, K. L.

    2015-08-01

    The spin-polarized transport properties of a high-spin-state spin-crossover molecular junction with zigzag-edge graphene nanoribbon electrodes have been studied using density functional theory combined with the nonequilibrium Green’s-function formalism. The molecular junction presents integrated spintronic functionalities such as negative differential resistance behavior, spin filter and the spin rectifying effect, associated with the giant magnetoresistance effect by tuning the external magnetic field. Furthermore, the transport properties are almost unaffected by the electrode temperature. The microscopic mechanism of these functionalities is discussed. These results represent a step toward multifunctional molecular spintronic devices on the level of the individual spin-crossover molecule.

  3. High-spin states in {sup 91,92,93}Rb and {sup 155,156}Pm

    SciTech Connect

    Hwang, J. K.; Ramayya, A. V.; Hamilton, J. H.; Liu, S. H.; Li, K.; Crowell, H. L.; Goodin, C.; Luo, Y. X.; Rasmussen, J. O.; Zhu, S. J.

    2009-09-15

    The excited states of the neutron-rich nuclei {sup 155,156}Pm and {sup 91,92,93}Rb were studied from the spontaneous fission of {sup 252}Cf. The {gamma}-{gamma}-{gamma} and x(Pm)-{gamma}-{gamma} triple coincidence relations were applied to identify the {gamma} transitions. Fourteen, six, three, twelve, and twelve new {gamma} transitions from high-spin states were observed in {sup 155,156}Pm, {sup 91,92}Rb, and {sup 93}Rb (first levels), respectively. The {pi}5/2[532] rotational band in {sup 155}Pm was extended up to 23/2{sup -}. The {pi}g{sub 9/2} particle states and {pi}f{sub 5/2} particle states in {sup 91,93}Rb weakly coupled to {sup 90,92}Kr, respectively, are reported.

  4. Quasi 2D electronic states with high spin-polarization in centrosymmetric MoS2 bulk crystals.

    PubMed

    Gehlmann, Mathias; Aguilera, Irene; Bihlmayer, Gustav; Młyńczak, Ewa; Eschbach, Markus; Döring, Sven; Gospodarič, Pika; Cramm, Stefan; Kardynał, Beata; Plucinski, Lukasz; Blügel, Stefan; Schneider, Claus M

    2016-06-01

    Time reversal dictates that nonmagnetic, centrosymmetric crystals cannot be spin-polarized as a whole. However, it has been recently shown that the electronic structure in these crystals can in fact show regions of high spin-polarization, as long as it is probed locally in real and in reciprocal space. In this article we present the first observation of this type of compensated polarization in MoS2 bulk crystals. Using spin- and angle-resolved photoemission spectroscopy (ARPES), we directly observed a spin-polarization of more than 65% for distinct valleys in the electronic band structure. By additionally evaluating the probing depth of our method, we find that these valence band states at the point in the Brillouin zone are close to fully polarized for the individual atomic trilayers of MoS2, which is confirmed by our density functional theory calculations. Furthermore, we show that this spin-layer locking leads to the observation of highly spin-polarized bands in ARPES since these states are almost completely confined within two dimensions. Our findings prove that these highly desired properties of MoS2 can be accessed without thinning it down to the monolayer limit.

  5. Quasi 2D electronic states with high spin-polarization in centrosymmetric MoS2 bulk crystals

    PubMed Central

    Gehlmann, Mathias; Aguilera, Irene; Bihlmayer, Gustav; Młyńczak, Ewa; Eschbach, Markus; Döring, Sven; Gospodarič, Pika; Cramm, Stefan; Kardynał, Beata; Plucinski, Lukasz; Blügel, Stefan; Schneider, Claus M.

    2016-01-01

    Time reversal dictates that nonmagnetic, centrosymmetric crystals cannot be spin-polarized as a whole. However, it has been recently shown that the electronic structure in these crystals can in fact show regions of high spin-polarization, as long as it is probed locally in real and in reciprocal space. In this article we present the first observation of this type of compensated polarization in MoS2 bulk crystals. Using spin- and angle-resolved photoemission spectroscopy (ARPES), we directly observed a spin-polarization of more than 65% for distinct valleys in the electronic band structure. By additionally evaluating the probing depth of our method, we find that these valence band states at the point in the Brillouin zone are close to fully polarized for the individual atomic trilayers of MoS2, which is confirmed by our density functional theory calculations. Furthermore, we show that this spin-layer locking leads to the observation of highly spin-polarized bands in ARPES since these states are almost completely confined within two dimensions. Our findings prove that these highly desired properties of MoS2 can be accessed without thinning it down to the monolayer limit. PMID:27245646

  6. Quasi 2D electronic states with high spin-polarization in centrosymmetric MoS2 bulk crystals

    NASA Astrophysics Data System (ADS)

    Gehlmann, Mathias; Aguilera, Irene; Bihlmayer, Gustav; Młyńczak, Ewa; Eschbach, Markus; Döring, Sven; Gospodarič, Pika; Cramm, Stefan; Kardynał, Beata; Plucinski, Lukasz; Blügel, Stefan; Schneider, Claus M.

    2016-06-01

    Time reversal dictates that nonmagnetic, centrosymmetric crystals cannot be spin-polarized as a whole. However, it has been recently shown that the electronic structure in these crystals can in fact show regions of high spin-polarization, as long as it is probed locally in real and in reciprocal space. In this article we present the first observation of this type of compensated polarization in MoS2 bulk crystals. Using spin- and angle-resolved photoemission spectroscopy (ARPES), we directly observed a spin-polarization of more than 65% for distinct valleys in the electronic band structure. By additionally evaluating the probing depth of our method, we find that these valence band states at the point in the Brillouin zone are close to fully polarized for the individual atomic trilayers of MoS2, which is confirmed by our density functional theory calculations. Furthermore, we show that this spin-layer locking leads to the observation of highly spin-polarized bands in ARPES since these states are almost completely confined within two dimensions. Our findings prove that these highly desired properties of MoS2 can be accessed without thinning it down to the monolayer limit.

  7. High-spin states in the nuclei 91Y and 95Nb

    NASA Astrophysics Data System (ADS)

    Bucurescu, D.; Podolyák, Zs.; Rusu, C.; De Angelis, G.; Zhang, Y. H.; Căta-Danil, G.; Căta-Danil, I.; Ivaşcu, M.; Mărginean, N.; Mărginean, R.; Mihăilescu, L. C.; Suliman, G. A.; Regan, P. H.; Gelletly, W.; Langdown, S. D.; Valiente Dobón, J. J.; Bazzacco, D.; Lunardi, S.; Ur, C. A.; Axiotis, M.; Gadea, A.; Farnea, E.; Ionescu-Bujor, M.; Iordăchescu, A.; Kröll, Th.; Martinez, T.; Bizzetti, P. G.; Broda, R.; Medina, N. H.; Quintana, B.; Rubio, B.

    2005-03-01

    The positive-parity yrast states in the 91Y and 95Nb nuclei have been studied by γ-ray spectroscopy following heavy-ion-induced fusion-evaporation reactions. The lowest-lying transitions in these structures have been assigned via the p2n channel of the reactions of 12C (38 MeV) and 16O (48 MeV) beams with a 82Se target, studied at the Bucharest Tandem accelerator. More detailed level schemes have been determined subsequently in a study performed with the GASP array of the inverse reactions produced by a 82Se (470 MeV) beam from the Legnaro Tandem-LINAC accelerator with oxygen and possibly carbon contaminants of a 192Os target. The observed level schemes are compared with local systematics and shell-model calculations.

  8. An improved numerical method to compute neutron/gamma deexcitation cascades starting from a high spin state

    DOE PAGES

    Regnier, D.; Litaize, O.; Serot, O.

    2015-12-23

    Numerous nuclear processes involve the deexcitation of a compound nucleus through the emission of several neutrons, gamma-rays and/or conversion electrons. The characteristics of such a deexcitation are commonly derived from a total statistical framework often called “Hauser–Feshbach” method. In this work, we highlight a numerical limitation of this kind of method in the case of the deexcitation of a high spin initial state. To circumvent this issue, an improved technique called the Fluctuating Structure Properties (FSP) method is presented. Two FSP algorithms are derived and benchmarked on the calculation of the total radiative width for a thermal neutron capture onmore » 238U. We compare the standard method with these FSP algorithms for the prediction of particle multiplicities in the deexcitation of a high spin level of 143Ba. The gamma multiplicity turns out to be very sensitive to the numerical method. The bias between the two techniques can reach 1.5 γγ/cascade. Lastly, the uncertainty of these calculations coming from the lack of knowledge on nuclear structure is estimated via the FSP method.« less

  9. An improved numerical method to compute neutron/gamma deexcitation cascades starting from a high spin state

    SciTech Connect

    Regnier, D.; Litaize, O.; Serot, O.

    2015-12-23

    Numerous nuclear processes involve the deexcitation of a compound nucleus through the emission of several neutrons, gamma-rays and/or conversion electrons. The characteristics of such a deexcitation are commonly derived from a total statistical framework often called “Hauser–Feshbach” method. In this work, we highlight a numerical limitation of this kind of method in the case of the deexcitation of a high spin initial state. To circumvent this issue, an improved technique called the Fluctuating Structure Properties (FSP) method is presented. Two FSP algorithms are derived and benchmarked on the calculation of the total radiative width for a thermal neutron capture on 238U. We compare the standard method with these FSP algorithms for the prediction of particle multiplicities in the deexcitation of a high spin level of 143Ba. The gamma multiplicity turns out to be very sensitive to the numerical method. The bias between the two techniques can reach 1.5 γγ/cascade. Lastly, the uncertainty of these calculations coming from the lack of knowledge on nuclear structure is estimated via the FSP method.

  10. High-spin structure, K isomers, and state mixing in the neutron-rich isotopes 173Tm and 175Tm

    NASA Astrophysics Data System (ADS)

    Hughes, R. O.; Lane, G. J.; Dracoulis, G. D.; Byrne, A. P.; Nieminen, P. H.; Watanabe, H.; Carpenter, M. P.; Chowdhury, P.; Janssens, R. V. F.; Kondev, F. G.; Lauritsen, T.; Seweryniak, D.; Zhu, S.

    2012-11-01

    High-spin states in the odd-proton thulium isotopes 173Tm and 175Tm have been studied using deep-inelastic reactions and γ-ray spectroscopy. In 173Tm, the low-lying structure has been confirmed and numerous new states have been identified, including a three-quasiparticle Kπ= 19/2- isomer with a lifetime of τ=360(100) ns at 1906 keV and a five-quasiparticle Kπ=35/2- isomer with a lifetime of τ= 175(40) ns at 4048 keV. The Kπ=35/2- state is interpreted as a t-band configuration that shows anomalously fast decays. In 175Tm, the low-lying structure has been reevaluated, a candidate state for the 9/2-[514] orbital has been identified at 1175 keV, and the 7/2-[523] bandhead has been measured to have a lifetime of τ= 460(50) ns. Newly identified high-K structures in 175Tm include a Kπ=15/2- isomer with a lifetime of τ= 64(3) ns at 947 keV and a Kπ= 23/2+ isomer with a lifetime of τ= 30(20) μs at 1518 keV. The Kπ=15/2- isomer shows relatively enhanced decays to the 7/2-[523] band that can be explained by chance mixing with the 15/2- member of the 7/2- band. Multiquasiparticle calculations have been performed for 173Tm and 175Tm, the results of which compare well with the experimentally observed high-spin states.

  11. Magnetic moments, E3 transitions and the structure of high-spin core excited states in 211Rn

    NASA Astrophysics Data System (ADS)

    Poletti, A. R.; Dracoulis, G. D.; Byrne, A. P.; Stuchbery, A. E.; Poletti, S. J.; Gerl, J.; Lewis, P. M.

    1985-05-01

    The results of g-factor measurements of high-spin states in 211Rn are: Ex = 8856 + Δ' keV (Jπ = 63/2-), g = 0.626(7); 6101 + Δ' KeV (49/2+), 0.766(8); 5347 + Δ' KeV (43/2-), 0.74(2); 3927 + Δ KeV (35/2+), 1.017(12); 1578 + Δ KeV (17/2-), 0.912(9). These results together with measured E3 transition strengths and shell model calculations are used to assign configurations to the core excited states in 211Rn. Mixed configurations are required to explain the g-factors and enhanced E3 strengths simultaneously.

  12. Evidence for isovector neutron-proton pairing from high-spin states in N=Z 74Rb

    NASA Astrophysics Data System (ADS)

    O'Leary, C. D.; Svensson, C. E.; Frauendorf, S. G.; Afanasjev, A. V.; Appelbe, D. E.; Austin, R. A.; Ball, G. C.; Cameron, J. A.; Clark, R. M.; Cromaz, M.; Fallon, P.; Hodgson, D. F.; Kelsall, N. S.; Macchiavelli, A. O.; Ragnarsson, I.; Sarantites, D.; Waddington, J. C.; Wadsworth, R.

    2003-02-01

    High-spin states in the odd-odd N=Z nucleus 7437Rb37 were studied using the 40Ca(40Ca,αnp) reaction. A previously observed odd-spin T=0 band has been extended to Iπ=(31+) and an even-spin T=0 band has been observed for the first time to Iπ=(22+); both have a π(g9/2)⊗ν(g9/2) structure. A strongly coupled low-spin T=0,K=3 band has been interpreted as being based upon a π[312]3/2⊗ν[312]3/2 configuration. Cranked relativistic Hartree-Bogoliubov calculations, which are corrected for the t=1 np-pair field by restoring isospin symmetry, reproduce the observed spectrum. These new results provide evidence for the existence of an isovector pair field that contains a neutron-proton component with the proper strength for ensuring isospin conservation.

  13. Calculations of the production cross sections of high-spin isomeric states in hafnium

    SciTech Connect

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

    1991-06-01

    This paper reports on the {sup 178}Hf(16{sup +}) isometric state that has a 31-yr half-life and could pose serious radioactive activation problems in nuclear fusion reactors if its production in 14-MeV neutron induced reactions is significant. The relatively high excitation energy (2.447 MeV) of this state causes it to lie in the continuum region. If rotational band members above this state were populated in a reaction, they would gamma cascade into it. While the existence of such levels can be justified theoretically, they have not been experimentally resolved; therefore, it is necessary to reconstruct the rotational levels built on the isomeric state. Using preequilibrium and compound nucleus theories, the cross sections for this and other hafnium isomeric states are calculated and compared with experimental measurements where available.

  14. High-spin states in the five-valence-particle nucleus {sup 213}Po

    SciTech Connect

    Astier, Alain; Porquet, Marie-Genevieve

    2011-03-15

    Excited states in {sup 213}Po have been populated using the {sup 18}O+ {sup 208}Pb reaction at 85 MeV beam energy and studied with the Euroball IV {gamma} multidetector array. The level scheme has been built up to {approx}2.0 MeV excitation energy and spin I{approx}25/2({h_bar}/2{pi}) from the triple {gamma} coincidence data. Spin and parity values of several yrast states have been assigned from the {gamma} angular properties. The configurations of the yrast states are discussed using results of empirical shell-model calculations and by analogy with the neighboring nuclei. The spin and parity values of several low-spin states of {sup 213}Po previously identified from the {beta} decay of {sup 213}Bi are revised.

  15. Single particle signatures in high-spin, quasicontinuum, states in {sup 193,194}Hg from g-factor measurements.

    SciTech Connect

    Weissman, L.; Mayer, R. H.; Kumbartzki, G.; Benczer-Koller, N.; Broude, C.; Cizewski, J. A.; Hass, M.; Holden, J.; Janssens, R. V. F.; Lauritsen, T.; Lee, I. Y.; Macchiavelli, A. O.; McNabb, D. P.; Satteson, M.; Physics; Weizmann Inst. of Science; Rutgers Univ.; LBNL

    1999-01-14

    The average g factors of high spin, high-excitation energy, quasicontinuum structures in {sup 194,193}Hg were measured by observing the precessions of the angular distributions of {gamma}-ray transitions in several normal-deformation bands that coalesce in the decay of the entry distribution of states. The average g factors of the states leading to the three main bands in the {sup 193,194}Hg isotopes were: {l_angle}g({sup 193}Hg){r_angle}=+0.19(1) and {l_angle}g({sup 194}Hg){r_angle}=+0.26(1), respectively. These average g factors are smaller than the average of the g factors of the high energy states in the three superdeformed bands of {sup 194}Hg, {l_angle}g(SD; {sup 194}Hg){r_angle}=+0.41(8). While the nucleus in the superdeformed well behaves like a rigid rotor, the present results demonstrate the important role played by multiple, quasiparticle neutron configurations in the structure of normal-deformation, highly-excited nuclear states.

  16. Microscopic structure of high-spin vibrational states in superdeformed A=190 nuclei

    SciTech Connect

    Nakatsukasa, Takashi; Matsuyanagi, Kenichi; Mizutori, Shoujirou

    1996-12-31

    Microscopic RPA calculations based on the cranked shell model are performed to investigate the quadrupole and octupole correlations for excited superdeformed (SD) bands in even-even A=190 nuclei. The K = 2 octupole vibrations are predicted to be the lowest excitation modes at zero rotational frequency. The Coriolis coupling at finite frequency produces different effects depending on the neutron and proton number of nucleus. The calculations also indicate that some collective excitations may produce moments of inertia almost identical to those of the yrast SD band. An interpretation of the observed excited bands invoking the octupole vibrations is proposed, which suggests those octupole vibrations may be prevalent in even-even SD A=190 nuclei.

  17. A shell model study of the high spin states of 88Y

    NASA Astrophysics Data System (ADS)

    Bunce, M.; Regan, P. H.; Werner, V.; Anagnostatou, V.; Beausang, C. W.; Bowry, M.; Casperson, R. J.; Chen, D.; Cooper, N.; Goddard, P.; Hughes, R. O.; Ilie, G.; Mason, P. J. R.; Pauerstein, B.; Reed, M. W.; Ross, T. J.

    2012-09-01

    Experiments were carried out at the Wright Nuclear Structure Laboratory at Yale University using the 21MV ESTU Tandem Van de Graaff accelerator with the purpose of studying 88Y. A beam of 18O impinged at laboratory energies of 60, 65 and 70 MeV on a 600 μg/cm2 74Ge target with a thick (10mg/cm2) 197Au backing. This experiment was performed with the specific aim of accessing medium spin states of the nucleus of interest. A second experiment was undertaken to populate the nucleus of interest in higher spin states by impinging the same 18O beam on a thin 62 μg/cm2 76Ge target with a 20 μg/cm2 carbon backing at a laboratory beam energy of 90 MeV. Gamma rays emitted following the decay of excited states in 88Y and other nuclei populated in the reactions were measured using the YRAST ball detector array, consisting of 10 Compton suppressed HPGe clover detectors. In conjunction with the experimental study presented here, nuclear shell model calculations using a truncated valence space have also been performed in an attempt to describe the single-particle make-up of the states observed. Preliminary results from these experiments and theoretical calculations are presented.

  18. Limits of studying high-spin states by discrete-line gamma-ray spectroscopy

    SciTech Connect

    Riedinger, L. L.

    1980-01-01

    Recent (HI, xn) data on rotational Yb and Hf nuclei are used to describe the motivations and techniques for pushing discrete-line spectroscopy to the realm of the weakly populated yrast and non-yrast states. Three aspects of these studies are discussed: extraction of moments of inertia in different aligned bands, observation and understanding of high-frequency band crossings, and dependence of feeding patterns on nuclear structure.

  19. High spin polarization and the origin of unique ferromagnetic ground state in CuFeSb

    SciTech Connect

    Sirohi, Anshu; Saha, Preetha; Gayen, Sirshendu; Gaurav, Abhishek; Jyotsna, Shubhra; Sheet, Goutam; Singh, Chandan K.; Kabir, Mukul; Thakur, Gohil S.; Haque, Zeba; Gupta, L. C.; Ganguli, Ashok K.

    2016-06-13

    CuFeSb is isostructural to the ferro-pnictide and chalcogenide superconductors and it is one of the few materials in the family that are known to stabilize in a ferromagnetic ground state. Majority of the members of this family are either superconductors or antiferromagnets. Therefore, CuFeSb may be used as an ideal source of spin polarized current in spin-transport devices involving pnictide and the chalcogenide superconductors. However, for that the Fermi surface of CuFeSb needs to be sufficiently spin polarized. In this paper we report direct measurement of transport spin polarization in CuFeSb by spin-resolved Andreev reflection spectroscopy. From a number of measurements using multiple superconducting tips we found that the intrinsic transport spin polarization in CuFeSb is high (∼47%). In order to understand the unique ground state of CuFeSb and the origin of large spin polarization at the Fermi level, we have evaluated the spin-polarized band structure of CuFeSb through first principles calculations. Apart from supporting the observed 47% transport spin polarization, such calculations also indicate that the Sb-Fe-Sb angles and the height of Sb from the Fe plane are strikingly different for CuFeSb than the equivalent parameters in other members of the same family thereby explaining the origin of the unique ground state of CuFeSb.

  20. Population of high spin states in very heavy ion transfer reactions. The experimental evidence

    SciTech Connect

    Guidry, M.W.

    1985-01-01

    Transfer reactions have been studied for some time with light heavy ions such as oxygen. Although states of spin I approx.10 h are sometimes populated in such reactions, it is assumed that collective excitation is small, and the transferred particles are responsible for the angular momentum transfer. In this paper we will discuss a qualitatively different kind of transfer reaction using very heavy ions (A greater than or equal to 40). In these reactions the collective excitation in both the entrance and exit channels is strong, and there may be appreciable angular momentum transfer associated with inelastic excitation. 12 refs., 13 figs.

  1. High-spin states in {sup 92-96}Zr nuclei

    SciTech Connect

    Pantelica, D.; Stefan, I.Gh.; Nica, N.; Porquet, M.-G.; Deloncle, I.; Bauchet, A.; Wilson, A.

    2005-08-01

    The {sup 92-96}Zr nuclei were produced as fission fragments following the fusion reactions {sup 28}Si+{sup 176}Yb and {sup 31}P+{sup 176}Yb at 145 and 152 MeV bombarding energy, respectively. Prompt {gamma} rays emitted in the two reactions were detected with the EUROGAM II and EUROBALL IV arrays. Sequences of {gamma}-ray transitions observed in coincidence were newly assigned to {sup 93-96}Zr. The previously known level schemes have been extended to higher excitation energies and higher spins. The experimental results are discussed in the framework of shell-model calculations with {sup 88}Sr assumed to be an inert core and the valence protons and neutrons filling the {pi}(2p{sub 1/2},1g{sub 9/2}) and {nu}(2d{sub 5/2},3s{sub 1/2}) orbitals.

  2. Lifetimes of high-spin states in {sup 180-184}Pt

    SciTech Connect

    Carpenter, M.P.; Ahmad, I.; Crowell, B.

    1995-08-01

    Over the past few years, lifetimes were measured, using the recoil distance method, to investigate shape-coexistence and shape transitions in the even mass {sup 182-186}Pt isotopes. In all three cases, one observes a sharp increase in the transition quadrupole moment, Q{sub t}, at low frequencies followed by a rapid and significant decline in the backbending region. It was shown that the initial increase in the Q{sub t} can be explained in terms of the mixing at low spins of two bands of very different deformation, and the decline in the backbending region is brought about by mixing between the ground and a two-quasiparticle band. No lifetime information exists for these nuclei above the backbend, and there is some contention whether or not the backbend is due to the alignment of h{sub 9/2} protons, i{sub 13/2} neutrons or the near simultaneous alignment of both. Nilsson-Strutinsky calculations indicate very different shapes for the nuclei after the backbend, depending on which orbitals align. Thus, lifetime information on the states above the backbend should help determine which interpretation is correct. In order to determine the lifetimes of states in the even mass {sup 180-184}Pt nuclei above the backbend, we performed a recent experiment at Gammasphere using a {sup 64}Ni beam on Pb backed Sn targets in order to populate the nucleus of interest via a 4n reaction. At the time of the experiment, thirty-six Ge detectors were available for use in Gammasphere and approximately 100 x 10{sup 6} 3-fold and higher events were taken for each nucleus. Currently, angle-sorted matrices were created from the data, and spectra representing the ground bands show well developed lineshapes for transitions above the backbend. A full lineshape analysis of the data will begin shortly.

  3. Negative-parity high-spin states and a possible magnetic rotation band in 76 59 135Pr

    NASA Astrophysics Data System (ADS)

    Garg, Ritika; Kumar, S.; Saxena, Mansi; Goyal, Savi; Siwal, Davinder; Kalkal, Sunil; Verma, S.; Singh, R.; Pancholi, S. C.; Palit, R.; Choudhury, Deepika; Ghugre, S. S.; Mukherjee, G.; Kumar, R.; Singh, R. P.; Muralithar, S.; Bhowmik, R. K.; Mandal, S.

    2015-11-01

    Excited states in 135Pr have been investigated using the reaction 123Sb(16O,4 n )135Pr at an incident beam energy of 82 MeV. The partial level scheme has been established for negative-parity states with addition of new γ -ray transitions. The directional correlation and polarization measurements have been performed to assign spin parity for most of the reported γ -ray transitions. At high spin, a negative-parity dipole band (Δ I =1 ) has been reported along with the observation of new crossover E 2 transitions. Tilted Axis Cranking (TAC) calculations have been performed by considering a three-quasiparticle (3qp) configuration π (h11/2) 1⊗ν (h11/2) -2 and a five-quasiparticle (5qp) configuration π (h11/2) 1(g7/2) 2⊗ν (h11/2) -2 for the lower and upper parts of the band, respectively. The observed results are compared with the results of the theoretical (TAC) calculations.

  4. Evidence for single particle structure of high spin states in [sup 144]Pm and [sup 145]Pm

    SciTech Connect

    Glasmacher, T.; Caussyn, D.D.; Cottle, P.D.; Holcomb, J.W.; Johnson, T.D.; Kemper, K.W.; Kennedy, M.A.; Womble, P.C. )

    1993-06-01

    Excited states of the [ital Z]=61 isotopes [sup 144]Pm[sub 83] and [sup 154]Pm[sub 84] have been studied in the [sup 19]F+[sup 130]Te reaction at a beam energy of 85 MeV. Gamma-ray and conversion electron spectroscopy were used to establish the high spin states of [sup 144]Pm up to spin 20[h bar] and to extend the level spectrum of [sup 145]Pm up to a tentative spin of 33/2[h bar]. Empirical shell model calculations in a configuration space truncated to the [pi]1[ital h][sub 11/2], [pi]1[ital g][sub 7/2][sup [minus]1], and [pi]2[ital d][sub 5/2][sup [minus]1] protons and the [nu]2[ital f][sub 7/2] neutron outside the [sup 146]Gd core reproduce the observed energy levels in good agreement with the experimental results. ([pi][ital h][sub 11/2])[sup 2] configurations are suggested in an [ital N]=83 isotone for [ital Z][lt]64.

  5. High-spin states in /sup 201,203/At and the systematic behavior of Z = 85 isotopes

    SciTech Connect

    Dybdal, K.; Chapuran, T.; Fossan, D.B.; Piel, W.F. Jr.; Horn, D.; Warburton, E.K.

    1983-09-01

    A spectroscopic investigation of high-spin states in /sup 201,203/At was performed by means of the reactions /sup 192,194/Pt(/sup 14/N,5n)/sup 201,203/At with /sup 14/N energies between 85 and 100 MeV. In-beam measurements of ..gamma..-ray excitation functions, ..gamma..-..gamma.. coincidences, ..gamma..-ray angular distributions, and pulsed-beam-..gamma.. timing were made to determine the decay scheme, level energies, ..gamma..-ray multipolarities, spin-parity assignments, and isomeric lifetimes. The yrast and near-yrast level structures were established up to Japprox.(25/2), and several isomers with mean lifetimes around 20 ns were observed. The systematic trends of level energies of the odd-mass astatine (Z = 85) isotopes are discussed in terms of proton-particle configurations of /sup 211//sub 85/At/sub 126/ coupled to neutron-hole configurations of the corresponding even-mass lead isotones.

  6. Measurement of lifetimes of high spin states in the N = 106 nuclei {sup 183}Ir and {sup 182}Os

    SciTech Connect

    Ahmad, I.; Blumenthal, D.; Carpenter, M.P.

    1995-08-01

    Lifetimes of high spin states in the isotones {sup 183}Ir and {sup 182}Os were measured using the Notre Dame plunger device in conjunction with the Argonne Notre Dame {gamma}-ray facility. The aim of these measurements was to determine the deformation-driving properties of the h{sub 9/2} proton intruder orbital by comparing the values of the intrinsic quadrupole moments in the ground state bands in the odd-mass Ir nucleus and the even-even Os core. Levels in these nuclei were populated by the {sup 150}Nd ({sup 37}Cl,4n) and {sup 150}Nd ({sup 36}S,4n) reactions using a {sup 37}Cl beam of 169 MeV and 164-Mev {sup 36}S beam. The {sup 150}Nd target was 0.9-g/cm{sup 2} thick and was prepared by evaporating enriched {sup 150}Nd onto a stretched 1.5-mg/cm{sup 2} gold foil. The target was covered with a layer of a 60-{mu}g/cm{sup 2} Au to prevent its oxidation. Gamma-ray spectra were accumulated for approximately 4 hours for each target-stopper distance. Data were collected for 20 target-stopper distances ranging from 16 {mu}m to 10.4 mm. Preliminary analysis indicates that it will be possible to extract the lifetimes of the levels in the yrast bands up to and including part of the backbending region with sufficient accuracy. Detailed analysis of the data is in progress.

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Observation of high-spin mixed oxidation state of cobalt in ceramic Co{sub 3}TeO{sub 6}

    SciTech Connect

    Singh, Harishchandra E-mail: singh85harish@rrcat.gov.in; Ghosh, Haranath; Sinha, A. K.; Chandrasekhar Rao, T. V.; Rajput, Parasmani

    2014-12-07

    We report coexistence of high spin Co{sup 3+} and Co{sup 2+} in ceramic Co{sub 3}TeO{sub 6} using X-ray Absorption Near Edge Structure (XANES), DC magnetization, and first principles ab-initio calculations. The main absorption line of cobalt Co K-edge XANES spectra, along with a linear combination fit, led us to estimate relative concentration of Co{sup 2+} and Co{sup 3+}as 60:40. The pre edge feature of XANES spectrum shows crystal field splitting of ∼1.26 eV between e{sub g} and t{sub 2g} states, suggesting a mixture of high spin states of both Co{sup 2+} and Co{sup 3+}. Temperature dependent high field DC magnetization measurements reveal dominant antiferromagnetic order with two Neel temperatures (T{sub N1} ∼ 29 K and T{sub N2} ∼ 18 K), consistent with single crystal study. A larger effective magnetic moment is observed in comparison to that reported for single crystal (which contains only Co{sup 2+}), supports our inference that Co{sup 3+} exists in high spin state. Furthermore, we show that both Co{sup 2+} and Co{sup 3+} being in high spin states constitute a favorable ground state through first principles ab-initio calculations, where Rietveld refined synchrotron X-ray diffraction data are used as input.

  9. Unusual high-spin Fe5 +-Ni3 + state and strong ferromagnetism in the mixed perovskite SrFe0.5Ni0.5O3

    NASA Astrophysics Data System (ADS)

    Fan, Fengren; Li, Zhengwei; Zhao, Zhen; Yang, Ke; Wu, Hua

    2016-12-01

    The charge-spin-orbital state plays a vital role in correlated oxides with mixed transition-metal elements, and it is often a matter of debate. Here, we address this issue for the newly synthesized unusual high-valence perovskite SrFe1 -xNixO3 , using an analysis of crystal-field level diagrams, density functional calculations, and Monte Carlo simulations. We have identified the formal high-spin Fe5 +(t2g 3, S =3 /2 ) and high-spin Ni3 +(t2g 5eg2 , S =3 /2 ) state for SrFe0.5Ni0.5O3 , rather than the previously suggested high-spin Fe4 +(t2g 3eg1, S =2 ) and low-spin Ni4 + (t2g 6, S =0 ) state. Moreover, our model and the present results well explain the observed small lattice variation of SrFe1 -xNixO3 (0 ≤x ≤0.5 ) and the above room temperature ferromagnetic order in SrFe0.5Ni0.5O3 regardless of a Fe-Ni atomic order or disorder.

  10. Topological surface states with persistent high spin polarization across the Dirac point in Bi2Te2Se and Bi2Se2Te.

    PubMed

    Miyamoto, K; Kimura, A; Okuda, T; Miyahara, H; Kuroda, K; Namatame, H; Taniguchi, M; Eremeev, S V; Menshchikova, T V; Chulkov, E V; Kokh, K A; Tereshchenko, O E

    2012-10-19

    Helical spin textures with marked spin polarizations of topological surface states have been unveiled for the first time by state-of-the-art spin- and angle-resolved photoemission spectroscopy for two promising topological insulators, Bi(2)Te(2)Se and Bi(2)Se(2)Te. Their highly spin-polarized natures are found to be persistent across the Dirac point in both compounds. This novel finding paves a pathway to extending the utilization of topological surface states of these compounds for future spintronic applications.

  11. High-spin states and lifetimes in 33S and shell-model interpretation in the s d -f p space

    NASA Astrophysics Data System (ADS)

    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.

  12. Calorimetric measurements of the light-induced metastable high-spin state on the [Fe(PM-BiA) 2(NCS) 2] complex

    NASA Astrophysics Data System (ADS)

    Rodríguez-Velamazán, J. A.; Castro, M.; Palacios, E.; Burriel, R.; Sánchez Costa, J.; Létard, J. F.

    2007-02-01

    Heat capacity measurements have been obtained on a pellet sample of [Fe(PM-BiA) 2(NCS) 2] formed by applying uniaxial pressure on the powder compound. They show a broad heat capacity peak near 170 K corresponding to a thermal spin crossover transition with enthalpy and entropy values around 4 kJ mol -1 and 24 J mol -1 K -1, respectively, and a hysteresis of a few kelvins. Magnetic data of the pellet sample show a gradual and incomplete thermal transition. Light irradiation ( λ = 750-850 nm) at 5 K promotes the high-spin (HS) state and photomagnetic measurements give T(LIESST) = 68 ± 1 K. The heat capacity of this excited state has been measured and the relaxation from the HS to the LS state has been followed with AC calorimetry. An extended anomaly is observed centred at 66.5 K. This is the first calorimetric report of a sample on a LIESST state.

  13. Direct observation of high-spin states in manganese dimer and trimer cations by x-ray magnetic circular dichroism spectroscopy in an ion trap

    SciTech Connect

    Zamudio-Bayer, V.; Hirsch, K.; Langenberg, A.; Kossick, M.; Ławicki, A.; Lau, J. T.; Terasaki, A.; Issendorff, B. von

    2015-06-21

    The electronic structure and magnetic moments of free Mn{sub 2}{sup +} and Mn{sub 3}{sup +} 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 directly show that localized magnetic moments of 5 μ{sub B} are created by 3d{sup 5}({sup 6}S) states at each ionic core, which are coupled ferromagnetically 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 antibonding molecular orbital with an unpaired spin. This leads to total magnetic moments of 11 μ{sub B} for Mn{sub 2}{sup +} and 16 μ{sub B} for Mn{sub 3}{sup +}, with no contribution of orbital angular momentum.

  14. Direct observation of high-spin states in manganese dimer and trimer cations by x-ray magnetic circular dichroism spectroscopy in an ion trap.

    PubMed

    Zamudio-Bayer, V; Hirsch, K; Langenberg, A; Kossick, M; Ławicki, A; Terasaki, A; von Issendorff, B; Lau, J T

    2015-06-21

    The electronic structure and magnetic moments of free Mn2 (+) and Mn3 (+) 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 directly show that localized magnetic moments of 5 μB are created by 3d(5)((6)S) states at each ionic core, which are coupled ferromagnetically 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 antibonding molecular orbital with an unpaired spin. This leads to total magnetic moments of 11 μB for Mn2 (+) and 16 μB for Mn3 (+), with no contribution of orbital angular momentum.

  15. Spin blockade and coherent dynamics of high-spin states in a three-electron double quantum dot

    NASA Astrophysics Data System (ADS)

    Chen, Bao-Bao; Wang, Bao-Chuan; Cao, Gang; Li, Hai-Ou; Xiao, Ming; Guo, Guang-Can; Jiang, Hong-Wen; Hu, Xuedong; Guo, Guo-Ping

    2017-01-01

    Asymmetry in a three-electron double quantum dot (DQD) allows spin blockade, when spin-3/2 (quadruplet) states and spin-1/2 (doublet) states have different charge configurations. We have observed this DQD spin blockade near the (1,2)-(2,1) charge transition using a pulsed-gate technique and a charge sensor. We, then, use this spin blockade to detect Landau-Zener-Stückelberg interference and coherent oscillations between the spin quadruplet and doublet states. Such studies add to our understandings of coherence and control properties of three-spin states in a double dot, which, in turn, would benefit explorations into various qubit encoding schemes in semiconductor nanostructures.

  16. First observation of high-spin states in {sup 214}Po: Probing the valence space beyond {sup 208}Pb

    SciTech Connect

    Astier, Alain; Porquet, Marie-Genevieve

    2011-01-15

    Excited states in {sup 214}Po have been populated using the {sup 18}O + {sup 208}Pb reaction at 85-MeV beam energy and studied with the Euroball IV {gamma}-multidetector array. The level scheme has been built up to {approx}2.7-MeV excitation energy and spin I=12({h_bar}/2{pi}) from the triple-{gamma} coincidence data. Spin and parity values of most of the observed states have been assigned from the {gamma}-angular properties. The configurations of the yrast states are discussed using results of empirical shell-model calculations and by analogy with the neighboring nuclei. The {sup 214}Po level scheme established in this work constitutes an important step for the determination of the effective nucleon-nucleon interactions beyond N=126.

  17. IDENTIFICATION OF HIGH-SPIN STATES IN NEUTRON-RICH 88,90,92Kr AND 86Se

    SciTech Connect

    J. D. Cole

    2011-08-01

    Level schemes of even-even neutron-rich {sup 88-92}Kr and {sup 86}Se have been investigated by measuring triple-{gamma} coincidence data from the spontaneous fission of {sup 252}Cf with the Gammasphere detector array. The level scheme of {sup 88}Kr has been extended up to 7169 keV state. Several new excited states with new transitions have been identified in {sup 90,92}Kr and {sup 86}Se. Spins and parities have been assigned to levels in these nuclei by following regional systematics and angular correlation measurements. The level structures of the N = 52, 54, Se, Kr, and Sr isotones are discussed.

  18. Evolution with Composition of the d-Band Density of States at the Fermi Level in Highly Spin Polarized Co1-xFexS2

    NASA Astrophysics Data System (ADS)

    Kuhns, P. L.; Hoch, M. J. R.; Reyes, A. P.; Moulton, W. G.; Wang, L.; Leighton, C.

    2006-04-01

    Highly spin polarized (SP) and half-metallic ferromagnetic systems are of considerable current interest and of potential importance for spintronic applications. Recent work has demonstrated that Co1-xFexS2 is a highly polarized ferromagnet (FM) where the spin polarization can be tuned by alloy composition. Using Co59 FM-NMR as a probe, we have measured the low-temperature spin relaxation in this system in magnetic fields from 0 to 1.0 T for 0≤x≤0.3. The Co59 spin-lattice relaxation rates follow a linear T dependence. Analysis of the data, using expressions for a FM system, permits information to be obtained on the d-band density of states at the Fermi level. The results are compared with independent density of states values inferred from electronic specific heat measurements and band structure calculations. It is shown that FM-NMR can be an important method for investigating highly SP systems.

  19. Pressure Effect on the Structural Transition and Suppression of the High-Spin State in the Triple-Layer T'-La₄Ni₃O₈

    SciTech Connect

    Cheng, J.-G.; Zhou, J.-S.; Goodenough, J. B.; Zhou, H. D.; Matsubayashi, K.; Uwatoko, Y.; Kong, P. P.; Jin, C. Q.; Yang, W. G.; Shen, G. Y.

    2012-06-08

    We report a comprehensive high-pressure study on the triple-layer T'-La₄Ni₃O₈ with a suite of experimental probes, including structure determination, magnetic, and transport properties up to 50 GPa. Consistent with a recent ab inito calculation, application of hydrostatic pressure suppresses an insulator-metal spin-state transition at Pc≈6 GPa. However, a low-spin metallic phase does not emerge after the high-spin state is suppressed to the lowest temperature. For P>20 GPa, the ambient T' structure transforms gradually to a T-type structure, which involves a structural reconstruction from fluorite La–O₂–La blocks under low pressures to rock-salt LaO-LaO blocks under high pressures. Absence of the metallic phase under pressure has been discussed in terms of local displacements of O²⁻ ions in the fluorite block under pressure before a global T† phase is established.

  20. Pressure Effect on the Structural Transition and Suppression of the High-Spin State in the Triple-Layer T'-La₄Ni₃O₈

    DOE PAGES

    Cheng, J.-G.; Zhou, J.-S.; Goodenough, J. B.; ...

    2012-06-08

    We report a comprehensive high-pressure study on the triple-layer T'-La₄Ni₃O₈ with a suite of experimental probes, including structure determination, magnetic, and transport properties up to 50 GPa. Consistent with a recent ab inito calculation, application of hydrostatic pressure suppresses an insulator-metal spin-state transition at Pc≈6 GPa. However, a low-spin metallic phase does not emerge after the high-spin state is suppressed to the lowest temperature. For P>20 GPa, the ambient T' structure transforms gradually to a T†-type structure, which involves a structural reconstruction from fluorite La–O₂–La blocks under low pressures to rock-salt LaO-LaO blocks under high pressures. Absence of the metallicmore » phase under pressure has been discussed in terms of local displacements of O²⁻ ions in the fluorite block under pressure before a global T† phase is established.« less

  1. Analyzing the enforcement of a high-spin ground state for a metallacrown single-molecule magnet

    NASA Astrophysics Data System (ADS)

    Happ, P.; Sapozhnik, A.; Klanke, J.; Czaja, P.; Chernenkaya, A.; Medjanik, K.; Schuppler, S.; Nagel, P.; Merz, M.; Rentschler, E.; Elmers, H. J.

    2016-05-01

    We have studied element-selective magnetic properties of the hetero- and homometallic metallacrowns Cu (II) 2[12 -MCY N (S h i )-4 ] (Y =Cu , Fe, in short CuCu4 and CuFe4). These metallacrowns comprise four Fe or Cu ions surrounding a central Cu ion. Using x-ray magnetic circular dichroism we have probed local symmetries, electronic configuration, orbital and spin magnetic moments of the magnetic ions. The ratio between the Cu and Fe moment of -0.11 is independent of temperature in the range of 15 K to 90 K. The Cu moment shows antiparallel to the Fe moment. For CuCu4 we confirm the predicted S =1 /2 ground state. The comparison of the spectral dependence indicates a localization of the magnetic moment at the central Cu ion. The orbital to spin moment ratio is 0.03 for the Fe ion while a larger ratio of 0.12 was measured for the Cu ion in both compounds. The experimental results are compared to a mean field model and to an isotropic Heisenberg model.

  2. Doubly magic 208Pb: High-spin states, isomers, and E 3 collectivity in the yrast decay

    NASA Astrophysics Data System (ADS)

    Broda, R.; Janssens, R. V. F.; Iskra, Ł. W.; Wrzesinski, J.; Fornal, B.; Carpenter, M. P.; Chiara, C. J.; Cieplicka-Oryńczak, N.; Hoffman, C. R.; Kondev, F. G.; Królas, W.; Lauritsen, T.; Podolyak, Zs.; Seweryniak, D.; Shand, C. M.; Szpak, B.; Walters, W. B.; Zhu, S.; Brown, B. A.

    2017-06-01

    Yrast and near-yrast levels up to spin values in excess of I =30 ℏ have been delineated in the doubly magic 208Pb nucleus following deep-inelastic reactions involving 208Pb targets and, mostly, 430-MeV 48Ca and 1440-MeV 208Pb beams. The level scheme was established up to an excitation energy of 16.4 MeV, based on multifold γ-ray coincidence relationships measured with the Gammasphere array. Below the well-known, 0.5-μs 10+ isomer, ten new transitions were added to earlier work. The delineation of the higher parts of the level sequence benefited from analyses involving a number of prompt- and delayed-coincidence conditions. Three new isomeric states were established along the yrast line with Iπ=20- (10 342 keV), 23+ (11 361 keV), and 28- (13 675 keV), and respective half-lives of 22(3), 12.7(2), and 60(6) ns. Gamma transitions were also identified preceding in time the 28- isomer; however, only a few could be placed in the level scheme and no firm spin-parity quantum numbers could be proposed. In contrast, for most states below this 28- isomer, firm spin-parity values were assigned, based on total electron-conversion coefficients, deduced for low-energy (<500 keV ) transitions from γ-intensity balances, and on measured γ-ray angular distributions. The latter also enabled the quantitative determination of mixing ratios. The transition probabilities extracted for all isomeric transitions in 208Pb have been reviewed and discussed in terms of the intrinsic structure of the initial and final levels involved. Particular emphasis was placed on the many observed E 3 transitions as they often exhibit significant enhancements in strength [of the order of tens of Weisskopf units (W.u.)] comparable to the one seen for the neutron j15 /2→g9 /2 E 3 transition in 209Pb. In this context, the enhancement of the 725-keV E 3 transition (56 W.u.) associated with the decay of the highest-lying 28- isomer observed in this work remains particularly challenging to explain. Large

  3. Doubly magic Pb208 : High-spin states, isomers, and E3 collectivity in the yrast decay

    DOE PAGES

    Broda, R.; Janssens, R. V. F.; Iskra, Ł. W.; ...

    2017-06-12

    Yrast and near-yrast levels up to spin values in excess of I = 30h have been delineated in the doubly-magic 208Pb nucleus following deep-inelastic reactions involving 208Pb targets and, mostly, 430-MeV 48Ca and 1440-MeV 208Pb beams. The level scheme was established up to an excitation energy of 16.4 MeV, based on multi-fold γ-ray coincidence relationships measured with the Gammasphere array. Below the well-known, 0.5-μs 10+ isomer, ten new transitions were added to earlier work. The delineation of the higher parts of the level sequence benefited from analyses involving a number of prompt- and delayed-coincidence conditions. Three new isomeric states weremore » established along the yrast line with I π = 20- (10342 keV), 23+ (11361 keV), and 28- (13675 keV), and respective half-lives of 22(3), 12.7(2), and 60(6) ns. Gamma transitions were also identified preceding in time the 28- isomer, however, only a few could be placed in the level scheme and no firm spin-parity quantum numbers could be proposed. In contrast, for most states below this 28- isomer, firm spin-parity values were assigned, based on total electron-conversion coefficients, deduced for low-energy (<500 keV) transitions from γ-intensity balances, and on measured γ-ray angular distributions. The latter also enabled the quantitative determination of mixing ratios. The transition probabilities extracted for all isomeric transitions in 208Pb have been reviewed and discussed in terms of the intrinsic structure of the initial and final levels involved. Particular emphasis was placed on the many observed E3 transitions as they often exhibit significant enhancements in strength (of the order of tens of W.u.) comparable to the one seen for the neutron j15/2→g9/2 E3 transition in 209Pb. In this context, the enhancement of the 725-keV E3 transition (56 W.u.) associated with the decay of the highest-lying 28- isomer observed in this work remains particularly challenging to explain. Large-scale shell

  4. High-spin spectroscopy of natural and unnatural parity states in the mirror-pair {sup 45}V/{sup 45}Ti

    SciTech Connect

    Bentley, M.A.; Chandler, C.; Bednarczyk, P.

    2006-02-15

    High-spin states in the proton-rich nucleus {sup 45}V have been identified for the first time. A comprehensive {gamma}-ray decay scheme has been established following an experiment performed at the Vivitron accelerator at IReS Strasbourg by using the Euroball {gamma}-ray detector array coupled to the Neutron Wall and Euclides detector arrays. The natural (negative-) parity scheme is identified up to the f{sub 7/2} band termination in addition to a positive-parity collective structure based on a d{sub 3/2} particle-hole excitation. Comparison of this scheme with that of the mirror partner, {sup 45}Ti, has yielded detailed information on the variation of Coulomb energy as a function of excitation energy and angular momentum. This is the first time that such an analysis has been performed for a collective structure built on a cross-shell excitation. Comparison of the observed Coulomb energies with those predicted by large-scale shell-model calculations is presented. In this case, unusually, the calculations do not fare as well as for heavier nuclei in the shell. In addition, stark differences between the two nuclei are observed for the decay intensities of the parity-changing E1 decays that de-excite the positive-parity deformed bands.

  5. Dynamic Jahn–Teller Effect in the Metastable High-Spin State of Solvated [Fe(terpy) 2 ] 2+

    SciTech Connect

    Zhang, X.; Lawson Daku, M. L.; Zhang, J.; Suarez-Alcantara, K.; Jennings, G.; Kurtz, C. A.; Canton, S. E.

    2015-02-12

    Characterizing structural distortions in the metastable spin states of d4- 11 d7 transition metal ion complexes is crucial to understand the nature of their bistability 12 and eventually control their switching dynamics. In particular, the impact of the Jahn- 13 Teller effect needs to be assessed for any electronic configuration that could be 14 effectively degenerate, as in e.g. the high-spin (HS) manifold of highly symmetric 15 homoleptic FeII complexes. However, capturing its manifestations remains challenging 16 since crystallization generally alters the molecular conformations and their 17 interconversion. With the rapid progress of ultrafast X-ray absorption spectroscopy, it 18 is now possible to collect data with unprecedented signal-to-noise ratio, opening up for 19 detailed structural characterization of transient species in the homogeneous solution phase. By combining the analysis of 20 picosecond X-ray absorption spectra with DFT simulations, the structure of the photoinduced HS state is elucidated for solvated 21 [Fe(terpy)2]2+ (terpy = 2,2':6',2''-terpyridine). This species can be viewed as the average 5B structure in D2 symmetry that 22 originates from a dynamic Jahn-Teller effect in the HS manifold. These results evidence the active role played by this particular 23 instance of vibronic coupling in the formation of the HS state for this benchmark molecule. Ultimately, correlating the interplay 24 between intramolecular and intermolecular degrees of freedom to conformational strain and distortions in real time should 25 contribute to the development of advanced functionalities in transition metal ion complexes.

  6. Determination of the molecular structure of the short-lived light-induced high-spin state in the spin-crossover compound [Fe(6-mepy)3tren](PF6)2

    NASA Astrophysics Data System (ADS)

    Chakraborty, Pradip; Tissot, Antoine; Peterhans, Lisa; Guénée, Laure; Besnard, Céline; Pattison, Philip; Hauser, Andreas

    2013-06-01

    In the spin-crossover compound [Fe(6-mepy)3tren](PF6)2, (6-mepy)3tren = tris{4-[(6-methyl)-2-pyridyl]-3-aza-butenyl}amine, the high-spin state can be populated as a metastable state below the thermal transition temperature via irradiation into the metal to the ligand charge-transfer absorption band of the low-spin species. At 10 K, the lifetime of this metastable state is only 1 s. Despite this, it is possible to determine an accurate excited state structure by following the evolution of relevant structural parameters by synchrotron x-ray diffraction under continuous irradiation with increasing intensity. The difference in metal-ligand bond length between the high-spin and the low-spin states is found to be 0.192 Å, obtained from an analysis of the experimental data using the mean-field approximation to model cooperative effects.

  7. Pairing correlations in high-spin isomers

    SciTech Connect

    Odahara, A.; Gono, Y.; Fukuchi, T.; Wakabayashi, Y.; Sagawa, H.; Satula, W.; Nazarewicz, W.

    2005-12-15

    High-spin isomers with J{sup {pi}}=49/2{sup +} and 27{sup +} have been systematically observed in a number of N=83 isotones with 60{<=}Z{<=}67 at excitation energies {approx}9 MeV. Based on experimental excitation energies, an odd-even binding energy staggering has been extracted for the first time for these multi-quasiparticle states. Surprisingly, the magnitude of the odd-even effect in high-spin isomers turned out to be very close to that in ground states, thus challenging conventional wisdom that pairing correlations are reduced in highly excited states. Theoretical analysis based on mean-field theory explains the observed proton number dependence of the odd-even effect as a manifestation of strong pairing correlations in the highly excited states. Mean-field effects and the proton-neutron residual interaction on the odd-even staggering are also examined.

  8. BLACK HOLE-NEUTRON STAR MERGERS WITH A HOT NUCLEAR EQUATION OF STATE: OUTFLOW AND NEUTRINO-COOLED DISK FOR A LOW-MASS, HIGH-SPIN CASE

    SciTech Connect

    Deaton, M. Brett; Duez, Matthew D.; Foucart, Francois; O'Connor, Evan; Ott, Christian D.; Scheel, Mark A.; Szilagyi, Bela; Kidder, Lawrence E.; Muhlberger, Curran D. E-mail: m.duez@wsu.edu

    2013-10-10

    Neutrino emission significantly affects the evolution of the accretion tori formed in black hole-neutron star mergers. It removes energy from the disk, alters its composition, and provides a potential power source for a gamma-ray burst. To study these effects, simulations in general relativity with a hot microphysical equation of state (EOS) and neutrino feedback are needed. We present the first such simulation, using a neutrino leakage scheme for cooling to capture the most essential effects and considering a moderate mass (1.4 M{sub ☉} neutron star, 5.6 M{sub ☉} black hole), high-spin (black hole J/M {sup 2} = 0.9) system with the K{sub 0} = 220 MeV Lattimer-Swesty EOS. We find that about 0.08 M{sub ☉} of nuclear matter is ejected from the system, while another 0.3 M{sub ☉} forms a hot, compact accretion disk. The primary effects of the escaping neutrinos are (1) to make the disk much denser and more compact, (2) to cause the average electron fraction Y{sub e} of the disk to rise to about 0.2 and then gradually decrease again, and (3) to gradually cool the disk. The disk is initially hot (T ∼ 6 MeV) and luminous in neutrinos (L{sub ν} ∼ 10{sup 54} erg s{sup –1}), but the neutrino luminosity decreases by an order of magnitude over 50 ms of post-merger evolution.

  9. High-spin spectroscopy of 140Nd

    NASA Astrophysics Data System (ADS)

    Leguillon, R.; Petrache, C. M.; Zerrouki, T.; Konstantinopoulos, T.; Hauschild, K.; Korichi, A.; Lopez-Martens, A.; Frauendorf, S.; Ragnarsson, I.; Greenlees, P. T.; Jakobsson, U.; Jones, P.; Julin, R.; Juutinen, S.; Ketelhut, S.; Leino, M.; Nieminen, P.; Nyman, M.; Peura, P.; Rahkila, P.; Ruotsalainen, P.; Sandzelius, M.; Saren, J.; Scholey, C.; Sorri, J.; Uusitalo, J.; Hübel, H.; Neußer-Neffgen, A.; Al-Khatib, A.; Bürger, A.; Nenoff, N.; Singh, A. K.; Curien, D.; Hagemann, G. B.; Herskind, B.; Sletten, G.; Fallon, P.; Görgen, A.; Bednarczyk, P.; Cullen, D. M.

    2013-07-01

    The population of the high-spin states in 140Nd was investigated using the reaction 96Zr(48Ca,4n). The results from two experiments, one with the EUROBALL array and one with the JUROGAM II+RITU+GREAT setup employing the recoil decay tagging technique, have been combined to develop a very detailed level scheme for 140Nd. Twelve bands of quadrupole transitions and eleven bands of dipole transitions were identified and their connections to low-lying states were established. Calculations using the cranked Nilsson-Strutinsky and the tilted axis cranking models were used to interpret the observed structures. The overall good agreement between the experimental results and the calculations assuming a triaxial shape of the nucleus strongly support the existence of a stable triaxial shape at high spins in this mass region.

  10. New candidates for high spin isomeric targets

    NASA Astrophysics Data System (ADS)

    Tonchev, A. P.; Gangrsky, Yu. P.; Belov, A. G.

    1999-02-01

    Experimental results of the accumulation and study of reaction mechanism of the de-excitation of high spin isomeric targets 108mAg ( Jπ=6 +), 166mHo ( Jπ=7 -) and 180mTa ( Jπ=9 -) are discussed. Together with other isomers, such as 178m2Hf ( Jπ=16 +), 186mRe ( Jπ=8 +), 242m Am ( Jπ=5 -), which can be produced by neutron-capture reactions or in reactions involving heavy ions, they can possibly be used for new experiments in nuclear physics. The large integral cross section for neutron capture (usually some barns) and enough cooling time allows the ground state of these isomers to completely decay due to their short half-life. The large integral de-excitation cross section (more 10 mb MeV) in inelastic γ-quanta scattering allows for a successful measurement on a small number of atoms (<10 15) and makes them candidates for γ-laser on the nuclear levels.

  11. Theoretical study of dynamic electron-spin-polarization via the doublet-quartet quantum-mixed state and time-resolved ESR spectra of the quartet high-spin state.

    PubMed

    Teki, Yoshio; Matsumoto, Takafumi

    2011-04-07

    The mechanism of the unique dynamic electron polarization of the quartet (S = 3/2) high-spin state via a doublet-quartet quantum-mixed state and detail theoretical calculations of the population transfer are reported. By the photo-induced electron transfer, the quantum-mixed charge-separate state is generated in acceptor-donor-radical triad (A-D-R). This mechanism explains well the unique dynamic electron polarization of the quartet state of A-D-R. The generation of the selectively populated quantum-mixed state and its transfer to the strongly coupled pure quartet and doublet states have been treated both by a perturbation approach and by exact numerical calculations. The analytical solutions show that generation of the quantum-mixed states with the selective populations after de-coherence and/or accompanying the (complete) dephasing during the charge-recombination are essential for the unique dynamic electron polarization. Thus, the elimination of the quantum coherence (loss of the quantum information) is the key process for the population transfer from the quantum-mixed state to the quartet state. The generation of high-field polarization on the strongly coupled quartet state by the charge-recombination process can be explained by a polarization transfer from the quantum-mixed charge-separate state. Typical time-resolved ESR patterns of the quantum-mixed state and of the strongly coupled quartet state are simulated based on the generation mechanism of the dynamic electron polarization. The dependence of the spectral pattern of the quartet high-spin state has been clarified for the fine-structure tensor and the exchange interaction of the quantum-mixed state. The spectral pattern of the quartet state is not sensitive towards the fine-structure tensor of the quantum-mixed state, because this tensor contributes only as a perturbation in the population transfer to the spin-sublevels of the quartet state. Based on the stochastic Liouville equation, it is also

  12. Pairing Correlations at High Spins

    NASA Astrophysics Data System (ADS)

    Ma, Hai-Liang; Dong, Bao-Guo; Zhang, Yan; Fan, Ping; Yuan, Da-Qing; Zhu, Shen-Yun; Zhang, Huan-Qiao; Petrache, C. M.; Ragnarsson, I.; Carlsson, B. G.

    The pairing correcting energies at high spins in 161Lu and 138Nd are studied by comparing the results of the cranked-Nilsson-Strutinsky (CNS) and cranked-Nilsson-Strutinsky-Bogoliubov (CNSB) models. It is concluded that the Coriolis effect rather than the rotational alignment effect plays a major role in the reduction of the pairing correlations in the high spin region. Then we proposed an average pairing correction method which not only better reproduces the experimental data comparing with the CNS model but also enables a clean-cut tracing of the configurations thus the full-spin-range discussion on the various rotating bands.

  13. Signature inversion in odd-odd {sup 114}Rh: First identification of high-spin states in very neutron-rich {sup 114}Rh and application of the triaxial projected shell model

    SciTech Connect

    Liu, S. H.; Chen, Y. S.; Gao, Z. C.; Zhu, S. J.; Gu, L.; Yeoh, E. Y.; Luo, Y. X.; Rasmussen, J. O.; Ma, W. C.; Batchelder, J. C.; Ter-Akopian, G. M.; Oganessian, Yu. Ts.; Gelberg, A.

    2011-06-15

    High-spin excited states in the very neutron-rich nucleus {sup 114}Rh have been studied by examining the prompt {gamma} rays emitted in the spontaneous fission of {sup 252}Cf with the Gammasphere detector array. A high-spin level scheme of {sup 114}Rh has been established for the first time with 13 new levels. The level scheme is proposed to be built on a 7{sup -} state. The existence of a relatively large signature splitting and an yrare band show features which may indicate triaxial deformation. The phenomenon of signature inversion has been observed in {sup 114}Rh at I=12 ({h_bar}/2{pi}). The observed signature inversion of {sup 114}Rh is interpreted successfully in terms of the triaxial projected shell model. Theoretical calculations suggest that the negative-parity, yrast band of {sup 114}Rh has the two-quasi-particle configuration of {pi}g{sub 9/2} x {nu}h{sub 11/2}, consistent with the systematics of odd-odd Rh isotopes. The signature inversion at spin 12 ({h_bar}/2{pi}) may be attributed to the change of rotational mode, from quasi-particle aligned rotation at low spins to collective rotation at high spins.

  14. High-Spin Cobalt Hydrides for Catalysis

    SciTech Connect

    Holland, Patrick L.

    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.

  15. High-spin nuclear spectroscopy

    SciTech Connect

    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)

  16. High-Spin Structure of 102Ru

    SciTech Connect

    Sohler, D.; Timar, J.; Molnar, J.; Algora, A.; Dombradi, Zs.; Krasznahorkay, A.; Zolnai, L.; Rainovski, G.; Joshi, P.; Wadsworth, R.; Jenkins, D.G.; Raddon, P.M.; Simons, A.J.; Wilkinson, A.R.; Starosta, K.; Fossan, D.B.; Bednarczyk, P.; Curien, D.; Duchene, G.; Gizon, A.

    2005-11-21

    High-spin states in the nucleus 102Ru have been studied through the 96Zr(13C,{alpha}3n) reaction using the EUROBALL IV {gamma}-ray spectrometer accompanied by the DIAMANT array for the detection of charged particles. All previously known bands have been extended to higher spins and additional bands have been found. Comparing the experimental Routhians and aligned angular momenta to the predictions of Woods-Saxon TRS calculations, vh11/2(d5/2,g7/2) configurations have been assigned to the observed negative-parity bands.

  17. High-spin structure in 40K

    NASA Astrophysics Data System (ADS)

    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.

  18. Properties of nuclei at high spins. [A = 160 to 166

    SciTech Connect

    Stephens, F.S.

    1982-10-01

    Nuclei generate high spins by two methods, alignment of single particle angular momentum and collective rotation. The competition of these two modes is discussed for the highest spins 40 less than or equal to I less than or equal to 65 h bar. Evidence is presented that alignment of the h/sub 9/2/ and i/sub 13/2/ proton orbitals from the next higher major shell produces large affects at high spins in rotational nuclei in the A = 160-166 region. It is suggested that such major shell effects produce the still larger irregularities known to occur in the lighter nuclei of this region.

  19. Formation and stability of high-spin alkali clusters.

    PubMed

    Schulz, C P; Claas, P; Schumacher, D; Stienkemeier, F

    2004-01-09

    Helium nanodroplet isolation has been applied to agglomerate alkali clusters at temperatures of 380 mK. The very weak binding to the surface of the droplets allows a selection of only weakly bound, high-spin states. Here we show that larger clusters of alkali atoms in high-spin states can be formed. The lack of strong bonds from pairing electrons makes these systems nonmetallic, van der Waals-like complexes of metal atoms. We find that sodium and potassium readily form such clusters containing up to 25 atoms. In contrast, this process is suppressed for rubidium and cesium. Apparently, for these heavy alkalis, larger high-spin aggregates are not stable and depolarize spontaneously upon cluster formation.

  20. Formation and Stability of High-Spin Alkali Clusters

    NASA Astrophysics Data System (ADS)

    Schulz, C. P.; Claas, P.; Schumacher, D.; Stienkemeier, F.

    2004-01-01

    Helium nanodroplet isolation has been applied to agglomerate alkali clusters at temperatures of 380mK. The very weak binding to the surface of the droplets allows a selection of only weakly bound, high-spin states. Here we show that larger clusters of alkali atoms in high-spin states can be formed. The lack of strong bonds from pairing electrons makes these systems nonmetallic, vanderWaals like complexes of metal atoms. We find that sodium and potassium readily form such clusters containing up to 25atoms. In contrast, this process is suppressed for rubidium and cesium. Apparently, for these heavy alkalis, larger high-spin aggregates are not stable and depolarize spontaneously upon cluster formation.

  1. High spin spectroscopy of 201Tl

    NASA Astrophysics Data System (ADS)

    Das Gupta, S.; Bhattacharyya, S.; Pai, H.; Mukherjee, G.; Bhattacharya, Soumik; Palit, R.; Shrivastava, A.; Chatterjee, A.; Chanda, S.; Nanal, V.; Pandit, S. K.; Saha, S.; Sethi, J.; Thakur, S.

    2013-10-01

    The high spin structure of 201Tl has been studied by γ-ray spectroscopic method using the 198Pt(7Li,4n)201Tl reaction at 45 MeV beam energy. The level scheme of 201Tl has been considerably extended through the observation of 31 new transitions. Several new band structures have been established. The 9/2- oblate band has been significantly extended beyond the particle alignment frequencies. The band structures and the other excited states have been compared with the neighboring odd-A Tl isotopes and with the even-even core nucleus 200Hg. The total Routhian surface calculations have been performed to study the deformation and shape changes as a function of spin in this nucleus.

  2. High Spin Isomers and Super Heavy Elements (SHE) Synthesis

    SciTech Connect

    Popescu, Domitian G.

    2010-04-30

    To get closer to the SHE-Island the new radioactive beams are proposed for future fusion reaction. We suggest something different: to use the advantage of High Spin Isomer States, by tacking into account the importance of the G (spin-isospin cupling) suggested by Ripka 1.

  3. Production, chemical and isotopic separation of the178m2Hf high-spin isomer

    NASA Astrophysics Data System (ADS)

    Oganessian, Yu. Ts.; Hussonnois, M.; Brianôcon, Ch.; Karamian, S. A.; Szeglowski, Z.; Ledu, D.; Meunier, R.; Constantinescu, M.; Kim, J. B.; Constantinescu, O.

    1997-05-01

    The 178m2Hf with its long-lived (T1/2=31 y), high-spin Iπ = 16+, isomeric state, is a challenge for new and exotic nuclear physics studies. The 178m2Hf isomer has been produced in microweight quantities using the 176Yb(α,2n) nuclear reaction, by irradiation with a high-intensity beam using the U-200 cyclotron in Dubna. Radiochemistry and mass separation methods have been developed, with the aim to separate and purify the produced Hf material. Thin targets of isomeric hafnium-178 on carbon backings have been prepared and used in experiments with neutron, proton and deuteron beams.

  4. High-spin states in 79Kr populated by the 78Se(α, 3n) reaction and interpreted in terms of a quasiparticle-plus-rotor model

    NASA Astrophysics Data System (ADS)

    Behar, M.; Filevich, A.; Macchiavelli, A. O.; Szybisz, L.; Thieberger, P.

    1982-10-01

    Nuclear states of 79Kr were studied through the 78Se(α, 3n) reaction at an energy of 45 MeV. Excitation functions, γ-ray angular distributions, and γ-γ coincidences were performed. Three bands based on the g.s. (12-), 147.1 keV (52-), and 129.7 keV (72+) states were identified. Leading order analysis and quasiparticle-plus-rotor model calculations were performed. A good overall agreement was found between the experimental data and the theoretical predictions. NUCLEAR REACTIONS 78Se(α, 3n), E=30-55 MeV; measured σ(E, Eγ, θ), Eγ, Iγ, γ-γ coin. 79Kr deduced levels J. Enriched targets.

  5. Synthesis, redox, and magnetic properties of a neutral, mixed-valent heptanuclear manganese wheel with S = 27/2 high-spin ground state.

    PubMed

    Saalfrank, Rolf W; Scheurer, Andreas; Prakash, Raju; Heinemann, Frank W; Nakajima, Takayuki; Hampel, Frank; Leppin, Roland; Pilawa, Bernd; Rupp, Holger; Müller, Paul

    2007-03-05

    Reaction of lithium tetrachloromanganate(II) with N-n-butyldiethanolamine H2L3 (3) in the presence of LiH leads to the formation of wheel-shaped, mixed-valent heptanuclear, neutral complex {MnII subset[MnII2MnIII4Cl6(L3)6]} (4). The manganese wheel crystallizes in the triclinic space group P as 4.2CHCl3 or 4.3THF when either diethyl ether or n-pentane was allowed to diffuse into solutions of 4 in chloroform or tetrahydrofuran. The oxidation states of each manganese ion in 4.2CHCl3 or 4.3THF were assigned on the basis of detailed symmetry, bond length, and charge considerations, as well as by the Jahn-Teller axial elongation observed for the manganese(III) ions, and were further supported by cyclic voltammetry. The analysis of the SQUID magnetic susceptibility data for complex 4.2CHCl3 showed that the intramolecular magnetic coupling of the manganese(II,III) ions is dominated by ferromagnetic exchange interactions. This results in an S = 27/2 ground-state multiplet at low magnetic field. At fields higher than 0.68 T, the energetically lowest state is given by the mS = 31/2 component of the S = 31/2 multiplet due to the Zeeman effect. The ligand-field-splitting parameters were determined by anisotropy SQUID measurements on single crystalline samples along the crystallographic x, y, and z axes (D = -0.055 K, E = 6.6 mK) and by high-frequency electron spin resonance measurements on a polycrystalline powder of 4.2CHCl3 (D = -0.068 K, E = 9.7 mK). The resulting barrier height for magnetization reversal amounts to U approximately 10 K. Finally, 2DEG Hall magnetization measurements revealed that 4.2CHCl3 shows single-molecule magnet behavior up to the blocking temperature of about 0.6 K with closely spaced steps in the hysteresis because of the quantum tunneling of the magnetization.

  6. Nuclear inelastic scattering of 1D polymeric Fe(II) complexes of 1,2,4-aminotriazole in their high-spin and low-spin state

    NASA Astrophysics Data System (ADS)

    Wolny, Juliusz A.; Rackwitz, Sergej; Achterhold, Klaus; Muffler, Kai; Schünemann, Volker

    2012-03-01

    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)3]^{+2})_n complexes. The complexes have LS (S = 0) marker bands in the range of 300-500 cm - 1, while the marker bands corresponding to the HS (S = 2) state are detected between 200 cm - 1 and 300 cm - 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.

  7. High-spin structure of 134Xe

    NASA Astrophysics Data System (ADS)

    Vogt, A.; Birkenbach, B.; Reiter, P.; Blazhev, A.; Siciliano, M.; Valiente-Dobón, J. J.; Wheldon, C.; Bazzacco, D.; Bowry, M.; 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.; Freeman, S. J.; Gadea, A.; Geibel, K.; Gelletly, W.; Gengelbach, A.; Giaz, A.; Görgen, A.; Gottardo, A.; Hayes, A. B.; Hess, H.; Hua, H.; John, P. R.; Jolie, J.; Jungclaus, A.; 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.; Napoli, D.; Pearson, C. J.; Pellegri, L.; Podolyák, Zs.; Pollarolo, G.; Pullia, A.; Radeck, F.; Recchia, F.; Regan, P. H.; Şahin, E.; Scarlassara, F.; Sletten, G.; Smith, J. F.; Söderström, P.-A.; Stefanini, A. M.; Steinbach, T.; Stezowski, O.; Szilner, S.; Szpak, B.; Teng, R.; Ur, C.; Vandone, V.; Ward, D.; Warner, D. D.; Wiens, A.; Wu, C. Y.

    2016-05-01

    Detailed spectroscopic information on the N ˜82 nuclei is necessary to benchmark shell-model calculations in the region. The nuclear structure above long-lived isomers in 134Xe is investigated after multinucleon transfer (MNT) and actinide fission. Xenon-134 was populated as (i) a transfer product in 238U+ 136Xe and 208Pb+ 136Xe MNT reactions and (ii) as a fission product in the 238U+ 136Xe reaction employing the high-resolution Advanced Gamma Tracking Array (AGATA). Trajectory reconstruction has been applied for the complete identification of beamlike transfer products with the magnetic spectrometer PRISMA. The 198Pt 136Xe MNT reaction was studied with the γ -ray spectrometer GAMMASPHERE in combination with the gas detector array Compact Heavy Ion Counter (CHICO). Several high-spin states in 134Xe on top of the two long-lived isomers are discovered based on γ γ -coincidence relationships and information on the γ -ray angular distributions as well as excitation energies from the total kinetic energy loss and fission fragments. The revised level scheme of 134Xe is extended up to an excitation energy of 5.832 MeV with tentative spin-parity assignments up to 16+. Previous assignments of states above the 7- isomer are revised. Latest shell-model calculations employing two different effective interactions reproduce the experimental findings and support the new spin and parity assignments.

  8. Triaxiality and Exotic Rotations at High Spins in 134Ce

    DOE PAGES

    Petrache, C. M.; Guo, S.; Ayangeakaa, A. D.; ...

    2016-06-06

    High-spin states in Ce-134 have been investigated using the Cd-116(Ne-22,4n) reaction and the Gammasphere array. The level scheme has been extended to an excitation energy of similar to 30 MeV and spin similar to 54 (h) over bar. Two new dipole bands and four new sequences of quadrupole transitions were identified. Several new transitions have been added to a number of known bands. One of the strongly populated dipole bands was revised and placed differently in the level scheme, resolving a discrepancy between experiment and model calculations reported previously. Configurations are assigned to the observed bands based on cranked Nilsson-Strutinskymore » calculations. A coherent understanding of the various excitations, both at low and high spins, is thus obtained, supporting an interpretation in terms of coexistence of stable triaxial, highly deformed, and superdeformed shapes up to very high spins. Rotations around different axes of the triaxial nucleus, and sudden changes of the rotation axis in specific configurations, are identified, further elucidating the nature of high-spin collective excitations in the A = 130 mass region.« less

  9. High-spin rotational structures in {sup 76}Kr

    SciTech Connect

    Valiente-Dobon, J.J.; Svensson, C.E.; Finlay, P.; Grinyer, G.F.; Hyland, B.; Phillips, A.A.; Schumaker, M.A.; O'Leary, C.D.; Jenkins, D.; Johnston-Theasby, F.; Joshi, P.; Kelsall, N.S.; Wadsworth, R.; Ragnarsson, I.; Andreoiu, C.; Appelbe, D.E.; Austin, R.A.E.; Cameron, J.A.; Waddington, J.C.; Ball, G.C.

    2005-03-01

    High-spin states in {sup 36}{sub 76}Kr{sub 40} have been populated in the {sup 40}Ca({sup 40}Ca,4p){sup 76}Kr fusion-evaporation reaction at a beam energy of 165 MeV and studied using the Gammasphere and Microball multidetector arrays. The ground-state band and two signature-split negative parity bands of {sup 76}Kr have been extended to {approx}30({Dirac_h}/2{pi}). Lifetime measurements using the Doppler-shift attenuation method show that the transition quadrupole moment of these three bands decrease as they approach their maximum-spin states. Two signatures of a new rotational structure with remarkably rigid rotational behavior have been identified. The high-spin properties of these rotational bands are analyzed within the framework of configuration-dependent cranked Nilsson-Strutinsky calculations.

  10. High-spin rotational structures in 76Kr

    NASA Astrophysics Data System (ADS)

    Valiente-Dobón, J. J.; Svensson, C. E.; O'Leary, C. D.; Ragnarsson, I.; Andreoiu, C.; Appelbe, D. E.; Austin, R. A.; Ball, G. C.; Cameron, J. A.; Carpenter, M. P.; Clark, R. M.; Cromaz, M.; Dashdorj, D.; Fallon, P.; Finlay, P.; Freeman, S. J.; Garrett, P. E.; Görgen, A.; Grinyer, G. F.; Hodgson, D. F.; Hyland, B.; Jenkins, D.; Johnston-Theasby, F.; Joshi, P.; Kelsall, N. S.; Macchiavelli, A. O.; Moore, F.; Mukherjee, G.; Phillips, A. A.; Reviol, W.; Sarantites, D.; Schumaker, M. A.; Seweryniak, D.; Smith, M. B.; Waddington, J. C.; Wadsworth, R.; Ward, D.; Williams, S. J.

    2005-03-01

    High-spin states in Kr40 have been populated in the 40Ca(40Ca,4p)76Kr fusion-evaporation reaction at a beam energy of 165 MeV and studied using the Gammasphere and Microball multidetector arrays. The ground-state band and two signature-split negative parity bands of 76Kr have been extended to ~30ℏ. Lifetime measurements using the Doppler-shift attenuation method show that the transition quadrupole moment of these three bands decrease as they approach their maximum-spin states. Two signatures of a new rotational structure with remarkably rigid rotational behavior have been identified. The high-spin properties of these rotational bands are analyzed within the framework of configuration-dependent cranked Nilsson-Strutinsky calculations.

  11. High-spin states in110Cd

    NASA Astrophysics Data System (ADS)

    Juutinen, S.; Julin, R.; Ahonen, P.; Fahlander, C.; Hattula, J.; Kumpulainen, J.; Lampinen, A.; Lönnroth, T.; Müller, D.; Nyberg, J.; Pakkanen, A.; Piiparinen, M.; Thorslund, I.; Törmänen, S.; Virtanen, A.

    1990-12-01

    Levels of110Cd have been investigated via the96Zr(18O,4n)110Cd reaction by employing the NORD-BALL array of 17 Compton- suppressed Ge detectors. The yrast band has been observed up to I=28 ħ and 14.2 MeV excitation energy with band crossing at ħωc=0.35 MeV. At least three side bands have been constructed. The negative parity bands experience band crossings at ħωc ≈ 0.45 MeV.

  12. CHARACTERIZING THE PSYCHOLOGICAL STATE PRODUCED BY LSD.

    ERIC Educational Resources Information Center

    KATZ, MARTIN M.; AND OTHERS

    THE DEVELOPMENT AND COMPONENTS OF LYSERGIC ACID DIETHYLAMIDE (LSD) PRODUCED PSYCHOLOGICAL STATES ARE INVESTIGATED. THE SUBJECTS WERE PAID VOLUNTEERS FROM THE PATUXENT INSTITUTION, A TREATMENT CENTER FOR EMOTIONALLY UNSTABLE CRIMINAL OFFENDERS. IN ONE STUDY, GROUPS OF 23 SUBJECTS RECEIVED LSD, AN AMPHETAMINE, OR A PLACEBO. IN THE SECOND STUDY, 11…

  13. Designing magnetic organic lattices from high-spin polycyclic units.

    PubMed

    Trinquier, Georges; Suaud, Nicolas; Guihéry, Nathalie; Malrieu, Jean-Paul

    2011-11-18

    This work addresses the conception of purely organic magnetic materials by properly bridging high-spin polycyclic hydrocarbons A and B, through covalent ligands L. The strategy varies two degrees of freedom that govern the magnetic character of the A-L--B sequence, namely, the bridge response to spin polarization and the relative signs of spin density on carbon atoms to which the bridge is attached. Topological prescriptions based on Ovchinnikov's rule are proposed to predict ground-state spin multiplicities of various A-L-B sets. The relevance of these guiding principles is essentially confirmed through DFT calculations on dimers connected by conjugated bridges. The transferability of interunit magnetic couplings to larger assemblies is further checked, the building blocks tending to maintain their high-spin character whatever the environment. Such local designs open the way to periodic lattices of ferromagnetic, antiferromagnetic, ferrimagnetic, or paramagnetic materials.

  14. High-spin structure of {sup 102}Ru

    SciTech Connect

    Sohler, D.; Timar, J.; Molnar, J.; Dombradi, Zs.; Krasznahorkay, A.; Zolnai, L.; Rainovski, G.; Joshi, P.; Wadsworth, R.; Jenkins, D.G.; Raddon, P.M.; Simons, A.J.; Wilkinson, A.R.; Starosta, K.; Fossan, D.B.; Koike, T.; Vaman, C.; Algora, A.; Bednarczyk, P.; Curien, D.

    2005-06-01

    High-spin states in the nucleus {sup 102}Ru have been investigated via the {sup 96}Zr({sup 13}C,{alpha}3n) reaction at beam energies of 51 and 58 MeV, using the euroball IV {gamma}-ray spectrometer and the diamant charged particle array. Several new high-spin bands have been established. The ground-state band has been extended up to E{sub x}{approx}12 MeV with I{sup {pi}}=(26{sup +}); the previously published negative-parity bands have been extended up to E{sub x}{approx}11 and {approx} 9 MeV with I{sup {pi}}=(23{sup -}) and (20{sup -}), respectively. The deduced high-spin structure has been compared with Woods-Saxon total Routhian surface calculations and, on the basis of the measured Routhians, aligned angular momenta, and B(M1)/B(E2) ratios, {nu}h{sub 11/2}(g{sub 7/2},d{sub 5/2}) configurations are suggested for the negative-parity structures.

  15. Toroidal high-spin isomers in the nucleus 304120

    NASA Astrophysics Data System (ADS)

    Staszczak, A.; Wong, Cheuk-Yin; Kosior, A.

    2017-05-01

    Background: Strongly deformed oblate superheavy nuclei form an intriguing region where the toroidal nuclear structures may bifurcate from the oblate spheroidal shape. The bifurcation may be facilitated when the nucleus is endowed with a large angular moment about the symmetry axis with I =Iz . The toroidal high-K isomeric states at their local energy minima can be theoretically predicted using the cranked self-consistent Skyrme-Hartree-Fock method. Purpose: We use the cranked Skyrme-Hartree-Fock method to predict the properties of the toroidal high-spin isomers in the superheavy nucleus 120304184. Method: Our method consists of three steps: First, we use the deformation-constrained Skyrme-Hartree-Fock-Bogoliubov approach to search for the nuclear density distributions with toroidal shapes. Next, using these toroidal distributions as starting configurations, we apply an additional cranking constraint of a large angular momentum I =Iz about the symmetry z axis and search for the energy minima of the system as a function of the deformation. In the last step, if a local energy minimum with I =Iz is found, we perform at this point the cranked symmetry- and deformation-unconstrained Skyrme-Hartree-Fock calculations to locate a stable toroidal high-spin isomeric state in free convergence. Results: We have theoretically located two toroidal high-spin isomeric states of 120304184 with an angular momentum I =Iz=81 ℏ (proton 2p-2h, neutron 4p-4h excitation) and I =Iz=208 ℏ (proton 5p-5h, neutron 8p-8h) at the quadrupole moment deformations Q20=-297.7 b and Q20=-300.8 b with energies 79.2 and 101.6 MeV above the spherical ground state, respectively. The nuclear density distributions of the toroidal high-spin isomers 120304184(Iz=81 ℏ and 208 ℏ ) have the maximum density close to the nuclear matter density, 0.16 fm-3, and a torus major to minor radius aspect ratio R /d =3.25 . Conclusions: We demonstrate that aligned angular momenta of Iz=81 ℏ and 208 ℏ arising from

  16. Spectroelectrochemical evidence for the nitrosyl redox siblings NO+, NO*, and NO- coordinated to a strongly electron-accepting Fe(II) porphyrin: DFT calculations suggest the presence of high-spin states after reduction of the Fe(II)-NO- complex.

    PubMed

    Pellegrino, Juan; Hübner, Ralph; Doctorovich, Fabio; Kaim, Wolfgang

    2011-07-04

    Experimental and computational results for the electron-deficient porphyrin complex [Fe(NO)(TFPPBr(8))] (1; TFPPBr(8)=2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetrakis(pentafluorophenyl)porphyrin) are reported with respect to its electron-transfer behavior. Complex 1 undergoes three one-electron processes: two reversible reductions and one irreversible oxidation. Spectroelectrochemical measurements (IR and UV/Vis/NIR spectroscopy) of (14)NO- and (15)NO-containing material indicate that the first reduction to 1(-) occurs largely on the NO ligand to produce nitroxyl anion (NO(-)) character, as evident from the considerable change in ν(NO) from 1715 to around 1550 cm(-1). The second reduction to 1(2)(-) does not result in a further shift of ν(NO) to lower frequencies, but to a surprising high-energy shift to 1590 cm(-1). This and the notable changes of the characteristic porphyrin vibrations as well as significant changes of the UV/Vis absorptions indicate a porphyrin-centered process; DFT calculations predict the shift of ν(NO) to higher frequencies for the intermediate- and high-spin states of 1(2-). The oxidation of 1 is irreversible on the voltammetry timescale, but chemically reversible in spectroelectrochemical experiments, suggesting that the cationic form dissociates to the corresponding ferric porphyrin and NO. DFT calculations support the interpretation of the experimental results. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. High spin spectroscopy of near spherical nuclei: Role of intruder orbitals

    SciTech Connect

    Bhattacharyya, S.; Bhattacharjee, T.; Mukherjee, G.; Banerjee, D.; Das, S. K.; Guin, R.; Gupta, S. Das

    2014-08-14

    High spin states of nuclei in the vicinity of neutron shell closure N = 82 and proton shell closure Z = 82 have been studied using the Clovere Ge detectors of Indian National Gamma Array. The shape driving effects of proton and neutron unique parity intruder orbitals for the structure of nuclei around the above shell closures have been investigated using light and heavy ion beams. Lifetime measurements of excited states in {sup 139}Pr have been done using pulsed-beam-γ coincidence technique. The prompt spectroscopy of {sup 207}Rn has been extended beyond the 181μs 13/2{sup +} isomer. Neutron-rich nuclei around {sup 132}Sn have been produced from proton induced fission of {sup 235}U and lifetime measurement of low-lying states of odd-odd {sup 132}I have been performed from offline decay.

  18. High-spin structure of 104Pd

    NASA Astrophysics Data System (ADS)

    Sohler, D.; Kuti, I.; Timár, J.; Joshi, P.; Molnár, J.; Paul, E. S.; Starosta, K.; Wadsworth, R.; Algora, A.; Bednarczyk, P.; Curien, D.; Dombrádi, Zs.; Duchene, G.; Fossan, D. B.; Gál, J.; Gizon, A.; Gizon, J.; Jenkins, D. G.; Juhász, K.; Kalinka, G.; Koike, T.; Krasznahorkay, A.; Nyakó, B. M.; Raddon, P. M.; Rainovski, G.; Scheurer, J. N.; Simons, A. J.; Vaman, C.; Wilkinson, A. R.; Zolnai, L.

    2012-04-01

    The high-spin structure of the nucleus 104Pd was studied through the 96Zr(13C,5n) reaction at incident energies of 51 and 58 MeV, using the Euroball IV γ-ray spectrometer in conjunction with the DIAMANT charged-particle array. Several new medium- and high-spin bands were revealed. The already known positive-parity yrast and the negative-parity cascades were extended up to Ex˜13, ˜11, and ˜9 MeV with Iπ=(26+), Iπ=(23-), and (20-), respectively. The deduced band structures were compared with Woods-Saxon total Routhian surface (TRS) calculations. In addition, non-yrast low-lying positive-parity bands were identified, which were assigned to soft γ-vibrational excitations.

  19. Spectroscopic and structural investigations of the ferrous and ferric high-spin state of a ``picket—fence'' porphyrinato acetato iron complex. A refined model for the P460 center of hydroxylamine oxidoreductase

    NASA Astrophysics Data System (ADS)

    Bill, E.; Bominaar, E. L.; Ding, X.-O.; Fischer, J.; Gismelseed, A.; Nasri, H.; Trautwein, A. X.; Weiss, R.; Winkler, H.

    1992-04-01

    Mössbauer investigations were performed in the ferrous and ferric form of the ‘picket-fence’ porphyrinato acetato iron complex |Fe(CH3CO2) (TPpivP)|1-,0 at temperatures varying from 1.5 200K and in fields of 0 6.2T. The ferrous complex has an unusually large quadrupole splitting, ΔEQ=+4.25mms-1. The quadrupole splitting in the ferric species, ΔEQ=+1.1mms-1, is as normally found in ferric high-spin iron porphyrins. Spin-Hamiltonian analysis of the magnetic spectra yields zero-field parameters D=-0.9mms-1, E/D=0.33 and magnetic hyperfine parameters Ax,y=-17T, Az=-13.3T in the ferrous high-spin (S=2) complex, and D=7.5cm-1, E/D≈0 and Ax,y,z=20T in the ferric high-spin (S=5/2) species.

  20. Future directions for high-spin studies

    SciTech Connect

    Stephens, F.S.

    1982-11-01

    Some future directions for experimental high-spin studies are discussed, concentrating mainly on the region above I -- 30h, where the ..gamma..-ray spectra are currently unresolvable. The 4..pi.. NaI balls offer a means to exploit the temperature effects recently shown to exist in such spectra. Large arrays of Compton-suppressed Ge detectors, on the other and, lead to higher effective resolution as it becomes possible to study triple and quadruple coincident events.

  1. Nuclear moments of inertia at high spin

    SciTech Connect

    Deleplanque, M.A.

    1982-10-01

    The competition between collective motion and alignment at high spin can be evaluated by measuring two complementary dynamic moments of inertia. The first, I band, measured in ..gamma..-..gamma.. correlation experiments, relates to the collective properties of the nucleus. A new moment of inertia I/sub eff/ is defined here, which contains both collective and alignment effects. Both of these can be measured in continuum ..gamma..-ray spectra of rotational nuclei up to high frequencies. The evolution of ..gamma..-ray spectra for Er nuclei from mass 160 to 154 shows that shell effects can directly be observed in the spectra of the lighter nuclei.

  2. Toroidal high-spin isomers in the nucleus 120304

    DOE PAGES

    Staszczak, A.; Wong, Cheuk-Yin; Kosior, A.

    2017-05-22

    Strongly deformed oblate superheavy nuclei form an intriguing region where the toroidal nuclear structures may bifurcate from the oblate spheroidal shape. The bifurcation may be facilitated when the nucleus is endowed with a large angular moment about the symmetry axis withmore » $$I=I_{z}$$. The toroidal high-$K$ isomeric states at their local energy minima can be theoretically predicted using the cranked self-consistent Skyrme-Hartree-Fock method. We use the cranked Skyrme-Hartree-Fock method to predict the properties of the toroidal high-spin isomers in the superheavy nucleus $$^{304}{120}_{184}$$. This method consists of three steps: first, we use the deformation-constrained Skyrme-Hartree-Fock-Bogoliubov approach to search for the nuclear density distributions with toroidal shapes. Next, using these toroidal distributions as starting configurations we apply an additional cranking constraint of a large angular momentum $$I=I_{z}$$ about the symmetry $z$-axis and search for the energy minima of the system as a function of the deformation. In the last step, if a local energy minimum with $$I=I_{z}$$ is found, we perform at this point the cranked symmetry- and deformation-unconstrained Skyrme-Hartree-Fock calculations to locate a stable toroidal high-spin isomeric state in free convergence. Furthemore, we have theoretically located two toroidal high-spin isomeric states of $$^{304}{120}_{184}$$ with an angular momentum $I$=$$I_z$$=81$$\\hbar$$ (proton 2p-2h, neutron 4p-4h excitation) and $I$=$$I_z$$=208$$\\hbar$$ (proton 5p-5h, neutron 8p-8h) at the quadrupole moment deformations $$Q_{20}=-297.7$$~b and $$Q_{20}=-300.8$$~b with energies 79.2 MeV and 101.6 MeV above the spherical ground state, respectively. The nuclear density distributions of the toroidal high-spin isomers $$^{304}{120}_{184}(I_z$$=81$$\\hbar$$ and 208$$\\hbar$$) have the maximum density close to the nuclear matter density, 0.16 fm$$^{-3}$$, and a torus major to minor radius aspect ratio $R/d=3

  3. High-spin molecular resonances in 12C + 12C

    NASA Astrophysics Data System (ADS)

    Uegaki, E.; Abe, Y.

    2016-05-01

    Resonances observed in the 12C + 12C collisions are studied with a molecular model. At high spins J = 10-18, a stable dinuclear configuration is found to be an equator-equator touching one. Firstly, normal modes have been solved around the equilibrium, with spin J and K-quantum number being specified for rotation of the whole system. Secondly, with respect to large centrifugal energy, Coriolis coupling has been diagonalized among low-lying 11 states of normal-mode excitations, which brings K-mixing. The analyses of decay widths and excitation functions have been done. The molecular ground state exhibits alignments of the orbital angular momentum and the 12C spins, while some of the molecular excited states exhibit disalignments with small widths. Those results are surprisingly in good agreement with the experiments, which will light up a new physical picture of the highspin 12C + 12C resonances.

  4. High spin spectroscopy and shears mechanism in {sup 107}In

    SciTech Connect

    Negi, D.; Mohanto, G.; Kumar, R.; Singh, R. P.; Muralithar, S.; Bhowmik, R. K.; Trivedi, T.; Dhal, A.; Kumar, S.; Kumar, V.; Roy, S.; Raju, M. K.; Appannababu, S.; Kaur, J.; Bhati, A. K.; Sinha, R. K.; Pancholi, S. C.

    2010-05-15

    High spin states of {sup 107}In have been investigated using the reaction {sup 94}Mo({sup 16}O,p2n){sup 107}In at a beam energy of 70 MeV. A total of 62 new gamma transitions have been placed in the level scheme and several DELTAI=1 sequences and one DELTAI=2 sequence have been found. Lifetime measurements using the Doppler-shift attenuation method (DSAM) have been carried out for band states of DELTAI=1 and DELTAI=2. A decreasing trend of B(M1) strengths with increasing spin deduced for the DELTAI=1 band indicates the presence of a shears mechanism. The experimental data for this band are compared with the tilted axis cranking (TAC) calculations. The DELTAI=2 band has been found to be a deformed band with beta{sub 2}approx0.2.

  5. High-spin level scheme of {sup 194}Pb

    SciTech Connect

    Kutsarova, T.; Stefanova, E. A.; Minkova, A.; Lalkovski, S.; Korichi, A.; Lopez-Martens, A.; Hannachi, F.; Huebel, H.; Goergen, A.; Jansen, A.; Schoenwasser, G.; Khoo, T. L.; Herskind, B.; Bergstroem, M.; Bazzacco, D.; Podolyak, Z.

    2009-01-15

    High-spin states in {sup 194}Pb have been populated in the {sup 168}Er({sup 30}Si,4n) reaction at 142 MeV. The emitted {gamma} rays were detected by the EUROBALL III multidetector array. The level scheme was considerably extended and many previously observed {gamma}-ray transitions were reordered. Four new magnetic rotational bands were observed. The energies and spins of the bandheads of all previously observed magnetic rotational bands were corrected based on the observation of new transitions. From nine observed bands, only one could not be connected to the lower lying states. Based on comparison systematics with neighboring Pb isotopes and tilted-axis cranking model calculations previously reported, configuration assignments to the observed bands have been made.

  6. High-spin study of rotational structures in 72 Br

    NASA Astrophysics Data System (ADS)

    O'Leary, C. D.; Wadsworth, R.; Fallon, P.; Svensson, C. E.; Ragnarsson, I.; Appelbe, D. E.; Austin, R. A.; Ball, G. C.; Cameron, J. A.; Carpenter, M. P.; Clark, R. M.; Cromaz, M.; Deleplanque, M. A.; Diamond, R. M.; Hodgson, D. F.; Janssens, R. V.; Jenkins, D. G.; Kelsall, N. S.; Lane, G. J.; Lister, C. J.; Macchiavelli, A. O.; Sarantites, D.; Stephens, F. S.; Seweryniak, D.; Vetter, K.; Waddington, J. C.; Ward, D.

    2004-03-01

    High-spin states in 72 35 Br 37 were studied using the 40 Ca ( 36 Ar ,3pn ) reaction. The existing level scheme has been significantly modified and extended. Evidence has been found for a spin reassignment of -1ℏ to the previously observed negative-parity band, which carries implications for the interpretation of a signature inversion in this structure. One signature of the previously assigned positive-parity band is interpreted as negative parity and has been extended to Iπ = ( 22- ) and its signature partner has been observed up to Iπ = ( 19- ) for the first time. The remaining positive-parity band has been extended to Iπ = ( 29+ ) . A sequence of states observed to Iπ = ( 22+ ) may be the signature partner of this structure. Configurations have been assigned to each of these three structures through comparisons to cranked Nilsson-Strutinsky calculations.

  7. High spin structure and intruder configurations in 31P

    NASA Astrophysics Data System (ADS)

    Ionescu-Bujor, M.; Iordachescu, A.; Napoli, D. R.; Lenzi, S. M.; Mărginean, N.; Otsuka, T.; Utsuno, Y.; Ribas, R. V.; Axiotis, M.; Bazzacco, D.; Bizzeti-Sona, A. M.; Bizzeti, P. G.; Brandolini, F.; Bucurescu, D.; Cardona, M. A.; De Angelis, G.; De Poli, M.; Della Vedova, F.; Farnea, E.; Gadea, A.; Hojman, D.; Kalfas, C. A.; Kröll, Th.; Lunardi, S.; Martínez, T.; Mason, P.; Pavan, P.; Quintana, B.; Alvarez, C. Rossi; Ur, C. A.; Vlastou, R.; Zilio, S.

    2006-02-01

    The nucleus 31P has been studied in the 24Mg(16O,2αp) reaction with a 70-MeV 16O beam. A complex level scheme extended up to spins 17/2+ and 15/2-, on positive and negative parity, respectively, has been established. Lifetimes for the new states have been investigated by the Doppler shift attenuation method. Two shell-model calculations have been performed to describe the experimental data, one by using the code ANTOINE in a valence space restricted to the sd shell, and the other by applying the Monte Carlo shell model in a valence space including the sd-fp shells. The latter calculation indicates that intruder excitations, involving the promotion of a T=0 proton-neutron pair to the fp shell, play a dominant role in the structure of the positive-parity high-spin states of 31P.

  8. 7 CFR 1205.314 - Cotton-producing State.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Cotton-producing State. 1205.314 Section 1205.314... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.314 Cotton-producing State. Cotton-producing...

  9. 7 CFR 1205.314 - Cotton-producing State

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Cotton-producing State 1205.314 Section 1205.314... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.314 Cotton-producing State Cotton-producing...

  10. 7 CFR 1205.314 - Cotton-producing State.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Cotton-producing State. 1205.314 Section 1205.314... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.314 Cotton-producing State. Cotton-producing...

  11. 7 CFR 1205.314 - Cotton-producing State.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Cotton-producing State. 1205.314 Section 1205.314... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.314 Cotton-producing State. Cotton-producing...

  12. 7 CFR 1205.314 - Cotton-producing State.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Cotton-producing State. 1205.314 Section 1205.314... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.314 Cotton-producing State. Cotton-producing...

  13. Cross-shell excitations in {sup 30}Al and {sup 30}Si at high spin.

    SciTech Connect

    Steppenbeck, D.; Deacon, A. N.; Freeman, S. J.; Janssens, R. V .F.; Carpenter, M. P.; Hoffman, C. R.; Kay, B. P.; Lauritsen, T.; Lister, C. J.; O'Donnell, D.; Ollier, J.; Seweryniak, D.; Smith, J. F.; Spohr, K.-M.; Tabor, S. L.; Tripathi, V.; Wady, P. T.; Zhu, S.

    2010-12-01

    Yrast and near-yrast states in {sup 30}Al and {sup 30}Si have been populated to high spin with the {sup 18}O + {sup 14}C fusion-evaporation reaction in inverse kinematics. The level schemes for these two isobars have been extended up to J {approx} 9 {h_bar} at 9.4 and 15.5 MeV, respectively. Their decay schemes indicate that cross-shell excitations dominate at high spin, where negative-parity structures exist. Positive-parity states are compared to the results of shell-model calculations using the USD, USDA, and USDB effective interactions. The negative-parity levels are compared to predictions of the WBP interaction and the recently-developed WBP-a Hamiltonian, by allowing 1p-1h excitations to fp-shell orbitals. The results suggest that single-neutron excitations to the 0f7/2 orbital play a significant role at high spin.

  14. Half-lives of several states in isotopes produced in the SF of ^252Cf

    NASA Astrophysics Data System (ADS)

    Hwang, J. K.; Ramayya, A. V.; Hamilton, J. H.; Fong, D.; Beyer, C. J.; Gore, P. M.; Jones, E. F.; Teran, E.; Oberacker, V. E.; Umar, A. S.; Luo, Y. X.; Rasmussen, J. O.; Zhu, S. J.; Wu, S. C.; Lee, I. Y.; Fallon, P.; Stoyer, M. A.; Asztalos, S. J.; Ginter, T. N.; Cole, J. D.; Ter-Akopian, G. M.; Donangelo, R.

    2003-10-01

    Half-lives (T_1/2) of 15 states in isotopes produced in the SF of ^252Cf have been determined using a new technique. The ^252Cf source was placed inside the Gammasphere, and triple and higher fold coincidence events were recorded. The half-lives and quadrupole deformations of ^104Zr, ^152Ce, and ^158Sm are determined for the first time. Except for ^102Sr, ^104Zr(β_2=0.45(4)) and ^158Sm(β_2=0.46(5)) are the most deformed among medium and heavy nuclei. Large deformation could have its origin in the high spin down-sloping orbitals near Z=38,40,62 and N=40,64,96. These large prolate deformations at ^104Zr and ^158Sm are confirmed by Hartree-Fock-Bogoliubov calculations carried out in the present work. Further, an excited rotational band including seven new γ transitions in ^97Sr was also identified. The band head energy of the 829.8 keV state in ^97Sr has an half-life of 265(27) nsec.

  15. Deformed band structures at high spin in 200Tl

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Soumik; Bhattacharyya, S.; Das Gupta, S.; Pai, H.; Mukherjee, G.; Palit, R.; Xu, F. R.; Wu, Q.; Shrivastava, A.; Asgar, Md. A.; Banik, R.; Bhattacharjee, T.; Chanda, S.; Chatterjee, A.; Goswami, A.; Nanal, V.; Pandit, S. K.; Saha, S.; Sethi, J.; Roy, T.; Thakur, S.

    2017-01-01

    High-spin band structures of 200Tl have been studied by γ -ray spectroscopic methods using the 198Pt(7Li,5 n )200Tl reaction at 45 MeV of beam energy. The level scheme of 200Tl has been extended significantly and several new band structures have been established with the observation of 60 new transitions. The π h9 /2⊗ν i13 /2 oblate band has been extended beyond the particle alignment frequencies. The band structures and the other excited states have been compared with the neighboring odd-odd Tl isotopes. Total Routhian surface calculations have been performed to study the deformation and shape changes as a function of spin in this nucleus. These calculations could reproduce the particle alignment frequency and suggest that the neutron pair alignment in ν i13 /2 orbital induces γ softness in 200Tl.

  16. Ultra-High Spin Spectroscopy In Er Nuclei

    SciTech Connect

    Simpson, J.

    2008-11-11

    The discoveries observed in the ongoing conflict between collective and single-particle nuclear behaviour with increasing angular momentum have driven the field of nuclear spectroscopy for many decades and have given rise to new nuclear phenomena. Recently a new frontier of {gamma} spectroscopy at ultra-high spin has been opened in the rare-earth region with rotational bands that bypass the classic band-terminating states that appear at spin 45({Dirac_h}/2{pi}) in the N 90 Er nuclei. These weakly populated rotational structures have characteristics of triaxial strongly-deformed bands. Such structures have been observed in {sup 157,158,160}Er, following a series of experiments using the Gammasphere spectrometer. These observations herald a return to collective excitations at spins of about 50 to 65({Dirac_h}/2{pi}). This talk reviews the status of the spectroscopy and understanding of the observed structures in these Er and neighbouring nuclei.

  17. High-spin nuclear structure of (153,155,157)terbium and superdeformed bands in (132)praseodymium

    NASA Astrophysics Data System (ADS)

    Hartley, Daryl James

    High-spin states of the rare-earth nuclei 153,155,157Tb (Z=65) were populated using heavy- ion reactions at the Florida State University (FSU) tandem-linac and the Lawrence Berkeley National Laboratory (LBNL) 88' cyclotron facilities. The de- exciting γ rays were detected with either the Pittsburgh-Florida State Universities array (FSU) or the Gammasphere spectrometer (LBNL). Over 300 new transitions and 200 new levels were identified between the three odd- A nuclei. Additional high-spin information pertaining to 155Eu (Z=63) was also discovered and allowed a significant extension of its level scheme. In each of these nuclei, DCO measurements, rotational alignment behavior, and B(M1)/B(E2) and B(E1)/B(E2) transition strength ratios were analyzed. Cranked Shell Model calculations were performed and compared to the observed behavior in the Tb nuclei. A systematic study of the experimental signature splitting observed in the /pi h11/2 bands of the odd-Z, odd-A/approx160 nuclei is also discussed. In addition, superdeformed structures have been observed for the first time in the doubly odd nucleus 132Pr (Z=59). These latter bands were produced in a heavy-ion reaction at the LBNL 88' cyclotron facility and detected with the Gammasphere spectrometer and the Microball charged particle array. Possible quasiparticle assignments are given and extracted B(M1)/B(E2) ratios are consistent with large deformation.

  18. Triaxial superdeformed and normal-deformed high-spin band structures in {sup 170}Hf

    SciTech Connect

    Neusser-Neffgen, A.; Huebel, H.; Bringel, P.; Domscheit, J.; Mergel, E.; Nenoff, N.; Singh, A.K.; Hagemann, G.B.; Jensen, D.R.; Bhattacharya, S.; Curien, D.; Dorvaux, O.; Hannachi, F.; Lopez-Martens, A.

    2006-03-15

    The high-spin structure of {sup 170}Hf was investigated using the EUROBALL spectrometer. The previously known level scheme was extended in the low-spin region as well as to higher spins, and several new bands were discovered. In particular, two bands were identified which show the characteristics of triaxial superdeformation. One of these bands is strongly populated, and its excitation energy and spins are established. Configuration assignments are made to the normal-deformed bands based on comparisons of their properties with cranked shell model calculations. The results for the very high spin states provide important input for such calculations.

  19. High-spin structure of N˜eq Z nuclei around the A = 72 region

    NASA Astrophysics Data System (ADS)

    Kelsall, N. S.; Svensson, C. E.; Fischer, S.; Appelbe, D. E.; Austin, R. A. E.; Balamuth, D. P.; Ball, G. C.; Cameron, J. A.; Carpenter, M. P.; Clark, R. M.; Cromaz, M.; Deleplanque, M. A.; Diamond, R. M.; Fallon, P.; Hodgson, D. F.; Janssens, R. V. F.; Jenkins, D. G.; Lane, G. J.; Lister, C. J.; Macchiavelli, A. O.; O'Leary, C. D.; Sarantities, D. G.; Stephens, F. S.; Schmidt, D. C.; Seweryniak, D.; Vetter, K.; Waddington, J. C.; Wadsworth, R.; Ward, D.; Wilson, A. N.; Afanasjev, A. V.; Frauendorf, S.; Ragnarsson, I.

    2003-04-01

    High-spin states have been studied in 72Kr and 72Br using the 40 Ca + 40 Ca and 36 Ar + 40 Ca reactions at 164 and 145 MeV, respectively. The properties and configurations of the high-spin bands observed have been interpreted using unpaired cranked Nilsson-Strutinsky (CNS), and for 72Kr, paired cranked relativistic Hartree-Bogoliubov (CRHB) calculations. In 72Kr a new band has been identified that has the properties expected for the doubly aligned S-band configuration. In 72Br the previously known bands have been extended to higher spin. This has lead to a re-interpretation of the configurations.

  20. Applications of highly spin-polarized xenon in NMR

    SciTech Connect

    Long, Henry W.

    1993-09-01

    The main goal of the work presented in this thesis is produce highly spin-polarized xenon to create much greater signal intensities (up to 54,000 times greater) so as to allow studies to be made on systems with low surface area and long spin-lattice relaxation times. The spin-exchange optical pumping technique used to create high nuclear spin polarization is described in detail in chapter two. This technique is initially applied to some multiple-pulse optically detected NMR experiments in low magnetic field (50G) that allow the study of quadrupoler interactions with a surface of only a few square centimeters. In chapter three the apparatus used to allow high field 129Xe NMR studies to be performed with extremely high sensitivity is described and applied to experiments on diamagnetic susceptibility effects in thin (~2000 layers) films of frozen xenon. Preliminary surface investigations of laser polarized 129Xe adsorbed an a variety of materials (salts, molecular crystals, amorphous carbon, graphite) are then discussed. A full detailed study of the surface of a particular polymer, poly(acrylic acid), is presented in chapter four which shows the kind of detailed information that can be obtained from this technique. Along with preliminary results for several similar polymers, a summary is given of xenon studies of a novel ultra-high surface area polymer, poly(triarylcarbinol). Finally in chapter five the exciting possibility of transferring the high spin order of the laser polarized xenon has been used to transfer nuclear spin order to 13CO2 in a xenon matrix and to protons on poly(triarylcarbinol).

  1. 7 CFR 1230.26 - State where produced.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PORK PROMOTION, RESEARCH, AND CONSUMER INFORMATION Pork Promotion, Research, and Consumer Information Order Definitions § 1230.26 State where produced. State where produced means with respect to a porcine animal marketed as a feeder pig or...

  2. 7 CFR 1230.26 - State where produced.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PORK PROMOTION, RESEARCH, AND CONSUMER INFORMATION Pork Promotion, Research, and Consumer Information Order Definitions § 1230.26 State where produced. State where produced means with respect to a porcine animal marketed as a feeder pig or...

  3. 7 CFR 1230.26 - State where produced.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PORK PROMOTION, RESEARCH, AND CONSUMER INFORMATION Pork Promotion, Research, and Consumer Information Order Definitions § 1230.26 State where produced. State where produced means with respect to a porcine animal marketed as a feeder pig...

  4. Nuclear shape transitions and some properties of aligned-particle configurations at high spin

    SciTech Connect

    Koo, T.L.; Chowdhury, P.; Emling, H.

    1982-01-01

    Two topics are addressed in this paper. First, we discuss the variation of shapes with spin and neutron number for nuclei in the N approx. = 88 transitional region. Second, we present comments on the feeding times of very high spin single-particle yrast states.

  5. High-spin level scheme of doubly odd 128I

    NASA Astrophysics Data System (ADS)

    Ding, B.; Wang, H. X.; Jiang, H.; Zhang, Y. H.; Zhou, X. H.; Zhao, Y. M.; Wang, S. T.; Liu, M. L.; Li, G. S.; Zheng, Y.; Zhang, N. T.; Zhou, H. B.; Ma, Y. J.; Sasakiz, Y.; Yamada, K.; Ohshima, H.; Yokose, S.; Ishizuka, M.; Komatsubara, T.; Furuno, K.

    2012-09-01

    High-spin states in the odd-odd 128I have been studied experimentally using the 124Sn(7Li, 3nγ)128I reaction at beam energies of 28 and 32 MeV. A level scheme built on the known T1/2=175 ns, (6-) isomer has been established. The low-lying states in the level scheme have been proposed to be associated with the πd5/2⊗νh11/2 and πg7/2⊗νh11/2 two-quasiparticle excitations. The strongly populated negative-parity states, forming a bandlike structure, have been assigned to be based on the πg7/2⊗νh11/2 configuration. The πh11/2⊗νh11/2 multiplet 9+, 10+, and 11+ members have been identified according to the systematics of the corresponding level structures observed in the lighter odd-odd iodine isotopes. The two-quasiparticle configuration assignments are supported by the nucleon pair approximation and empirical shell-model calculations.

  6. High-spin band structure of 192Tl

    NASA Astrophysics Data System (ADS)

    Kreiner, A. J.; Filevich, A.; García Bermúdez, G.; Mariscotti, M. A. J.; Baktash, C.; der Mateosian, E.; Thieberger, P.

    1980-03-01

    High-spin states in 192Tl, excited through the 181Ta(18O,7n) and 181Ta(16O,5n) reactions, were studied using in-beam γ-ray spectroscopic techniques. Excitation functions, activity spectra, γ-ray angular distributions, and multidimensional coincidences were measured. The strongly Coríolis-distorted π~h92×ν~i132 two-quasiparticle band already known in the heavier 194,196,198Tl isotopes has also been found in this case based on an Iπ=8- isomeric state at 250.6 keV above the known long-lived 7+ level. Trends already noted in the other Tl isotopes and also predicted by two-quasiparticle plus-rotor model calculations are confirmed thus reinforcing such a theoretical description. NUCLEAR REACTIONS 181Ta(18O,xnγ), E=105-125 MeV; 181Ta(16O,xnγ), E=95-105 MeV; measured Eγ, Iγ, σ(E, Eγ, θγ), γ-γ coin.; 192Tl levels deduced, J, π, T12. Natural target. Ge(Li) detectors.

  7. High-spin resonances in heavy-ion collisions

    SciTech Connect

    Betts, R.R.; Saini, S.

    1982-01-01

    Excitation functions for elastic scattering and reactions of /sup 28/Si + /sup 28/Si show evidence for the existence of narrow (GAMMA = 100 to 200 keV) high-spin (J approx. = 40 ..pi..) resonances. The interpretation of these resonances as high-spin fissioning shape isomers is discussed with reference to data for the /sup 28/Si + /sup 30/Si and /sup 30/Si + /sup 30/Si systems.

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

    SciTech Connect

    Musiał, Monika Lupa, Łukasz; Kucharski, Stanisław A.

    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.

  9. Triaxiality and Exotic Rotations at High Spins in 134Ce

    SciTech Connect

    Petrache, C. M.; Garg, U.; Matta, J. T.; Nayak, B. K.; Patel, D.; Carpenter, M. P.; Chiara, C. J.; Janssens, R. V. F.; Kondev, F. G.; Lauritsen, T.; Seweryniak, D.; Zhu, S.; Ghugre, S. S.; Palit, R.

    2016-06-06

    High-spin states in Ce-134 have been investigated using the Cd-116(Ne-22,4n) reaction and the Gammasphere array. The level scheme has been extended to an excitation energy of similar to 30 MeV and spin similar to 54 (h) over bar. Two new dipole bands and four new sequences of quadrupole transitions were identified. Several new transitions have been added to a number of known bands. One of the strongly populated dipole bands was revised and placed differently in the level scheme, resolving a discrepancy between experiment and model calculations reported previously. Configurations are assigned to the observed bands based on cranked Nilsson-Strutinsky calculations. A coherent understanding of the various excitations, both at low and high spins, is thus obtained, supporting an interpretation in terms of coexistence of stable triaxial, highly deformed, and superdeformed shapes up to very high spins. Rotations around different axes of the triaxial nucleus, and sudden changes of the rotation axis in specific configurations, are identified, further elucidating the nature of high-spin collective excitations in the A = 130 mass region.

  10. Triaxiality and Exotic Rotations at High Spins in 134Ce

    SciTech Connect

    Petrache, C. M.; Garg, U.; Matta, J. T.; Nayak, B. K.; Patel, D.; Carpenter, M. P.; Chiara, C. J.; Janssens, R. V. F.; Kondev, F. G.; Lauritsen, T.; Seweryniak, D.; Zhu, S.; Ghugre, S. S.; Palit, R.

    2016-06-06

    High-spin states in Ce-134 have been investigated using the Cd-116(Ne-22,4n) reaction and the Gammasphere array. The level scheme has been extended to an excitation energy of similar to 30 MeV and spin similar to 54 (h) over bar. Two new dipole bands and four new sequences of quadrupole transitions were identified. Several new transitions have been added to a number of known bands. One of the strongly populated dipole bands was revised and placed differently in the level scheme, resolving a discrepancy between experiment and model calculations reported previously. Configurations are assigned to the observed bands based on cranked Nilsson-Strutinsky calculations. A coherent understanding of the various excitations, both at low and high spins, is thus obtained, supporting an interpretation in terms of coexistence of stable triaxial, highly deformed, and superdeformed shapes up to very high spins. Rotations around different axes of the triaxial nucleus, and sudden changes of the rotation axis in specific configurations, are identified, further elucidating the nature of high-spin collective excitations in the A = 130 mass region.

  11. Superdeformed band at very high spin in {sup 140}Nd

    SciTech Connect

    Neusser, A.; Huebel, H.; Al-Khatib, A.; Bringel, P.; Buerger, A.; Nenoff, N.; Schoenwasser, G.; Singh, A.K.; Petrache, C.M.; Lo Bianco, G.; Ragnarsson, I.; Hagemann, G.B.; Herskind, B.; Jensen, D.R.; Sletten, G.; Fallon, P.; Goergen, A.; Bednarczyk, P.; Curien, D.; Gangopadhyay, G.

    2004-12-01

    A new high-spin superdeformed band has been discovered in {sub 60}{sup 140}Nd{sub 80}. It was populated in the {sup 96}Zr({sup 48}Ca,4n) reaction and investigated using the EUROBALL {gamma}-ray spectrometer array. The band is observed in the approximate spin range of I=36 to 66. It is associated with shell gaps around Z=60 and at N=80 at large deformation. These gaps produce a pronounced minimum in the calculated total Routhian surfaces at a quadrupole deformation of {epsilon}{sub 2}=0.45. The new band which lies between the high-deformation bands in the A{approx_equal}130 region and the superdeformed bands in A{approx_equal}150 nuclei provides insight into the development of the deformation between these two regions. Two possible configurations are suggested involving four neutrons of i{sub 13/2} origin ({nu}6{sup 4}) and either six protons of h{sub 11/2}/h{sub 9/2} origin ({pi}5{sup 6}) or five protons of h{sub 11/2}/h{sub 9/2} and one of i{sub 13/2} origin ({pi}5{sup 5}6{sup 1})

  12. Produced water volumes and management practices in the United States.

    SciTech Connect

    Clark, C. E.; Veil, J. A.

    2009-09-01

    Produced water volume generation and management in the United States are not well characterized at a national level. The U.S. Department of Energy (DOE) asked Argonne National Laboratory to compile data on produced water associated with oil and gas production to better understand the production volumes and management of this water. The purpose of this report is to improve understanding of produced water by providing detailed information on the volume of produced water generated in the United States and the ways in which produced water is disposed or reused. As the demand for fresh water resources increases, with no concomitant increase in surface or ground water supplies, alternate water sources, like produced water, may play an important role. Produced water is water from underground formations that is brought to the surface during oil or gas production. Because the water has been in contact with hydrocarbon-bearing formations, it contains some of the chemical characteristics of the formations and the hydrocarbons. It may include water from the reservoir, water previously injected into the formation, and any chemicals added during the production processes. The physical and chemical properties of produced water vary considerably depending on the geographic location of the field, the geologic formation, and the type of hydrocarbon product being produced. Produced water properties and volume also vary throughout the lifetime of a reservoir. Produced water is the largest volume by-product or waste stream associated with oil and gas exploration and production. Previous national produced water volume estimates are in the range of 15 to 20 billion barrels (bbl; 1 bbl = 42 U.S. gallons) generated each year in the United States (API 1988, 2000; Veil et al. 2004). However, the details on generation and management of produced water are not well understood on a national scale. Argonne National Laboratory developed detailed national-level information on the volume of produced

  13. Isospin symmetry breaking at high spin in the mirror nuclei Ar35 and Cl35

    NASA Astrophysics Data System (ADS)

    Vedova, F. Della; Lenzi, S. M.; Ionescu-Bujor, M.; Mărginean, N.; Axiotis, M.; Bazzacco, D.; Bizzeti-Sona, A. M.; Bizzeti, P. G.; Bracco, A.; Brandolini, F.; Bucurescu, D.; Farnea, E.; Iordachescu, A.; Lunardi, S.; Martínez, T.; Mason, P.; Menegazzo, R.; Million, B.; Napoli, D. R.; Nespolo, M.; Pavan, P.; Alvarez, C. Rossi; Ur, C. A.; Venturelli, R.; Zuker, A. P.

    2007-03-01

    High-spin states in Ar35 and Cl35 have been populated in the Mg24(O16, αn) and Mg24(O16, αp) reactions, respectively, at a beam energy of 70 MeV. The comparison between the level schemes of these mirror nuclei shows a striking asymmetry in the population yield of high-spin analog states of positive parity, which indicates different intensities of E1 transitions connecting positive- and negative-parity structures in both nuclei. Large energy differences are observed between analog states of negative parity with configurations of dominant pure single-particle character. This results from the comparison with large-scale shell-model calculations in the s1/2d3/2f7/2p3/2 valence space. It is shown that important contributions to the energy differences arise from the multipole Coulomb and the relativistic electromagnetic spin-orbit interactions.

  14. Structure of odd-odd 136La at high spin

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Tumpa; Chanda, Somen; Bhattacharyya, Sarmishtha; Basu, Swapan Kumar; Bhowmik, R. K.; Muralithar, S.; Singh, R. P.; Pattabiraman, N. S.; Ghugre, S. S.; Datta Pramanik, U.; Bhattacharya, S.

    2005-04-01

    The high spin states in the N=79 odd-odd 136La nucleus have been investigated by in-beam γ-spectroscopic techniques following the 130Te( 11B, 5 n) 136La reaction at E=52 MeV using an array, consisting of eight Compton-suppressed clover germanium detectors. Thirty nine new γ rays have been assigned to 136La on the basis of γ ray singles and γγ-coincidence data. The level scheme of 136La has been extended above the known 115 ms isomer upto an excitation energy of 4.6 MeV and spin 18 ℏ. Thirty one new levels have been proposed and spin-parity assignments for most of the newly proposed levels have been made on the basis of the deduced asymmetry ratios and polarisation information for the de-exciting transitions. The observed positive parity yrast band has been compared with the theoretical calculation, done within the framework of particle rotor coupling model (PRM) where the two odd quasi-particles are coupled to an axially symmetric core. The level structure has been discussed in the light of the known systematics of the neighbouring N=79 isotonic nuclei.

  15. A new high-spin isomer in 195Bi

    NASA Astrophysics Data System (ADS)

    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.

  16. High spin γ -ray spectroscopy in 41Ca

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, R.; Samanta, S.; Das, S.; Bhattacharjee, S. S.; Raut, R.; Ghugre, S. S.; Sinha, A. K.; Garg, U.; Chakrabarti, R.; Mukhopadhyay, S.; Dhal, A.; Singh, R. P.; Madhavan, N.; Muralithar, S.

    2016-11-01

    High spin states in 41Ca have been investigated by using γ -ray spectroscopic techniques following the 27Al(16O,p n )41Ca fusion-evaporation reaction. Around twelve new transitions belonging to 41Ca have been observed and placed in the level scheme, which now has been extended up to Ex˜9 MeV. The spin-parity assignments for the observed levels were arrived at following the analysis of both the coincidence intensity anisotropies and linear polarization measurements. The established 5p-4h band was extended up to Jπ=19 /2- . The observations of Doppler shape and shifts facilitated the estimation of the level lifetimes by using the Doppler shift attenuation method. The lifetimes were validated with respect to previous measurements and lifetime of a few levels has been arrived at for the first time. Shell-model calculations were carried out to explain the observed level structure of the nucleus and are indicative of both single-particle and collective degrees of freedom in this N ˜Z ˜20 nucleus.

  17. The Electronic and Vibrational Energies of the High-Spin States of He2 Which Correspond Asymptotically to the Interaction of Two 1s2s 3S He Atoms.

    DTIC Science & Technology

    1986-06-01

    Scheaffer (GMS)2 treated these same three states in c~nnection with their study of Penning and associative ionization of 2 S atoms. GMS performed a...Helium Atoms," J. Chem. Phys., Vol. 50, p. 5151, 1969. ’V 2. Garrison, B.J., Miller. W.H.. and Scheaffer , H.F., "Penning and Associative Ionization of

  18. Loss of collectivity in the transitional {sup 156}Er nucleus at high spin

    SciTech Connect

    Paul, E. S.; Rigby, S. V.; Choy, P. T. W.; Evans, A. O.; Nolan, P. J.; Riley, M. A.; Campbell, D. B.; Pipidis, A.; Simpson, J.; Appelbe, D. E.; Joss, D. T.; Clark, R. M.; Cromaz, M.; Fallon, P.; Goergen, A.; Lee, I. Y.; Macchiavelli, A. O.; Ward, D.; Ragnarsson, I.

    2009-04-15

    The {sup 114}Cd({sup 48}Ca,6n{gamma}) reaction at 215 MeV has been investigated using the Gammasphere spectrometer to study the high-spin structure of the nucleus {sub 68}{sup 156}Er{sub 88}. Many new transitions have been established along with definitive spin-parity level assignments from a high-fold angular-distribution analysis. In addition, absolute B(M1) and B(E1) strengths have been inferred from measured {gamma}-ray branching ratios. Strong B(E1) strength (10{sup -3} W.u.) is discussed in terms of possible octupole collectivity at low spin. At high spin, this nucleus undergoes a Coriolis-induced shape transition from a prolate state of collective rotation to a noncollective, triaxial-oblate configuration. The yrast positive-parity structure ultimately terminates in an energetically favored oblate state at I{sup {pi}}=42{sup +}. Several weak high-energy {gamma}-ray transitions have been discovered that feed this favored state. State-of-the-art cranked Nilsson-Strutinsky calculations are used to interpret the high-spin behavior of {sup 156}Er and comparisons are made with other N=88 isotones.

  19. High Spin Polarization at Ferromagnetic Metal-Organic Interfaces: A Generic Property.

    PubMed

    Djeghloul, Fatima; Gruber, Manuel; Urbain, Etienne; Xenioti, Dimitra; Joly, Loic; Boukari, Samy; Arabski, Jacek; Bulou, Hervé; Scheurer, Fabrice; Bertran, François; Le Fèvre, Patrick; Taleb-Ibrahimi, Amina; Wulfhekel, Wulf; Garreau, Guillaume; Hajjar-Garreau, Samar; Wetzel, Patrick; Alouani, Mebarek; Beaurepaire, Eric; Bowen, Martin; Weber, Wolfgang

    2016-07-07

    A high spin polarization of states around the Fermi level, EF, at room temperature has been measured in the past at the interface between a few molecular candidates and the ferromagnetic metal Co. Is this promising property for spintronics limited to these candidates? Previous reports suggested that certain conditions, such as strong ferromagnetism, i.e., a fully occupied spin-up d band of the ferromagnet, or the presence of π bonds on the molecule, i.e., molecular conjugation, needed to be met. What rules govern the presence of this property? We have performed spin-resolved photoemission spectroscopy measurements on a variety of such interfaces. We find that this property is robust against changes to the molecule and ferromagnetic metal's electronic properties, including the aforementioned conditions. This affirms the generality of highly spin-polarized states at the interface between a ferromagnetic metal and a molecule and augurs bright prospects toward integrating these interfaces within organic spintronic devices.

  20. PARTICLE-HOLE NATURE OF THE LIGHT HIGH-SPIN TOROIDAL ISOMERS

    SciTech Connect

    Staszczak, A.; Wong, Cheuk-Yin

    2015-01-01

    Nuclei under non-collective rotation with a large angular momentum above some threshold can assume a toroidal shape. In our previous work, we showed by using cranked Skyrme Hartree Fock approach that even even, N = Z, high-K, toroidal isomeric states may have general occurrences for light nuclei with 28 < A < 52. We present here some additional results and systematics on the particle-hole nature of these high-spin toroidal isomers.

  1. Toroidal high-spin isomers in light nuclei with N ≠ Z

    NASA Astrophysics Data System (ADS)

    Staszczak, A.; Wong, Cheuk-Yin

    2015-11-01

    The combined considerations of both the bulk liquid-drop-type behavior and the quantized aligned rotation with cranked Skyrme-Hartree-Fock approach revealed previously (Staszczak and Wong 2014 Phys. Lett. B 738 401) that even-even, N = Z, toroidal high-spin isomeric states have general occurrences for light nuclei with 28≤slant A≤slant 52. We find that in this mass region there are in addition N\

  2. CANCER MORTALITY IN FOUR NORTHERN WHEAT PRODUCING STATES

    EPA Science Inventory

    Chlorophenoxy herbicides are used both in cereal grain agriculture and in nonagricultural settings such as right-of-ways, lawns, and parks. Minnesota, North Dakota, South Dakota, and Montana grow most of the spring and durum wheat produced in the United States. More than 90% of s...

  3. 7 CFR 1216.15 - Minor peanut-producing states.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Minor peanut-producing states. 1216.15 Section 1216... SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PEANUT PROMOTION, RESEARCH, AND INFORMATION ORDER Peanut Promotion, Research, and Information Order Definitions...

  4. 7 CFR 1216.15 - Minor peanut-producing states.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Minor peanut-producing states. 1216.15 Section 1216... SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PEANUT PROMOTION, RESEARCH, AND INFORMATION ORDER Peanut Promotion, Research, and Information Order Definitions...

  5. 7 CFR 1216.21 - Primary peanut-producing states.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Primary peanut-producing states. 1216.21 Section 1216... SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PEANUT PROMOTION, RESEARCH, AND INFORMATION ORDER Peanut Promotion, Research, and Information Order Definitions...

  6. 7 CFR 1216.21 - Primary peanut-producing states.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Primary peanut-producing states. 1216.21 Section 1216... SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PEANUT PROMOTION, RESEARCH, AND INFORMATION ORDER Peanut Promotion, Research, and Information Order Definitions...

  7. 7 CFR 1216.21 - Primary peanut-producing states.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Primary peanut-producing states. 1216.21 Section 1216... SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PEANUT PROMOTION, RESEARCH, AND INFORMATION ORDER Peanut Promotion, Research, and Information Order Definitions...

  8. 7 CFR 1216.15 - Minor peanut-producing states.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Minor peanut-producing states. 1216.15 Section 1216... SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PEANUT PROMOTION, RESEARCH, AND INFORMATION ORDER Peanut Promotion, Research, and Information Order Definitions...

  9. 7 CFR 1216.21 - Primary peanut-producing states.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Primary peanut-producing states. 1216.21 Section 1216... SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PEANUT PROMOTION, RESEARCH, AND INFORMATION ORDER Peanut Promotion, Research, and Information Order Definitions...

  10. 7 CFR 1216.15 - Minor peanut-producing states.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Minor peanut-producing states. 1216.15 Section 1216... SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PEANUT PROMOTION, RESEARCH, AND INFORMATION ORDER Peanut Promotion, Research, and Information Order Definitions...

  11. 7 CFR 1216.15 - Minor peanut-producing states.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Minor peanut-producing states. 1216.15 Section 1216... SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PEANUT PROMOTION, RESEARCH, AND INFORMATION ORDER Peanut Promotion, Research, and Information Order Definitions...

  12. CANCER MORTALITY IN FOUR NORTHERN WHEAT PRODUCING STATES

    EPA Science Inventory

    Chlorophenoxy herbicides are used both in cereal grain agriculture and in nonagricultural settings such as right-of-ways, lawns, and parks. Minnesota, North Dakota, South Dakota, and Montana grow most of the spring and durum wheat produced in the United States. More than 90% of s...

  13. Limited Out-of-State Data Needed to Produce Robust Indicators. Breaking down State Silos

    ERIC Educational Resources Information Center

    Data Quality Campaign, 2012

    2012-01-01

    There is increasing demand on the education sector to produce high-quality, actionable information to inform decisions aimed at improving student achievement. Unfortunately, every state currently lacks the out-of-state data necessary to follow individuals systemically and efficiently across state lines. The absence of appropriate out-of-state data…

  14. High spins in gamma-soft nuclei

    SciTech Connect

    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...

  15. Observation of high-spin bands with large moments of inertia in Xe124

    DOE PAGES

    Nag, Somnath; Singh, A. K.; Hagemann, G. B.; ...

    2016-09-07

    In this paper, high-spin states in 124Xe have been populated using the 80Se(48Ca, 4n) reaction at a beam energy of 207 MeV and high-multiplicity, γ-ray coincidence events were measured using the Gammasphere spectrometer. Six high-spin rotational bands with 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. Finally, 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 excitedmore » across the N = 82 shell closure.« less

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

    NASA Astrophysics Data System (ADS)

    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.

  17. Observation of high-spin oblate band structures in {sup 141}Pm

    SciTech Connect

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

    2011-06-15

    The high-spin states of {sup 141}Pm have been investigated through the reaction {sup 126}Te({sup 19}F,4n) at a beam energy of 90 MeV. A previous level scheme has been updated with spins up to 49/2({h_bar}/2{pi}). 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 {Delta}I=1 M1 transitions inside the bands are suggested as the oblate bands with {gamma} {approx}-60 deg.; three other bands with large signature splitting have been proposed with the oblate-triaxial deformation with {gamma}{approx} -90 deg. The triaxial n-particle-n-hole particle rotor model calculations for one of the oblate bands in {sup 141}Pm are in good agreement with the experimental data. The other characteristics for these bands have been discussed.

  18. Force-producing ADP state of myosin bound to actin.

    PubMed

    Wulf, Sarah F; Ropars, Virginie; Fujita-Becker, Setsuko; Oster, Marco; Hofhaus, Goetz; Trabuco, Leonardo G; Pylypenko, Olena; Sweeney, H Lee; Houdusse, Anne M; Schröder, Rasmus R

    2016-03-29

    Molecular motors produce force when they interact with their cellular tracks. For myosin motors, the primary force-generating state has MgADP tightly bound, whereas myosin is strongly bound to actin. We have generated an 8-Å cryoEM reconstruction of this state for myosin V and used molecular dynamics flexed fitting for model building. We compare this state to the subsequent state on actin (Rigor). The ADP-bound structure reveals that the actin-binding cleft is closed, even though MgADP is tightly bound. This state is accomplished by a previously unseen conformation of the β-sheet underlying the nucleotide pocket. The transition from the force-generating ADP state to Rigor requires a 9.5° rotation of the myosin lever arm, coupled to a β-sheet rearrangement. Thus, the structure reveals the detailed rearrangements underlying myosin force generation as well as the basis of strain-dependent ADP release that is essential for processive myosins, such as myosin V.

  19. {gamma}-ray spectroscopy of neutron-deficient {sup 110}Te. II. High-spin smooth-terminating structures

    SciTech Connect

    Paul, E. S.; Evans, A. O.; Boston, A. J.; Nolan, P. J.; Semple, A. T.; Chiara, C. J.; Fossan, D. B.; Lane, G. J.; Sears, J. M.; Starosta, K.; Devlin, M.; LaFosse, D. R.; Sarantites, D. G.; Freeman, S. J.; Leddy, M. J.; Lee, I. Y.; Macchiavelli, A. O.; Smith, J. F.; Afanasjev, A. V.; Ragnarsson, I.

    2007-09-15

    High-spin states have been populated in {sub 52}{sup 110}Te via {sup 58}Ni({sup 58}Ni,{alpha}2p{gamma}) reactions at 240 and 250 MeV. The Gammasphere {gamma}-ray spectrometer was used in conjunction with the Microball charged-particle detector. The high-spin (I>30) collective level scheme of {sup 110}Te, up to {approx}45({Dirac_h}/2{pi}), is discussed in this paper. Four new decoupled ({delta}I=2) high-spin structures have been observed for the first time, together with two strongly coupled ({delta}I=1) bands. These bands all show the characteristics of smooth band termination, and are discussed within the framework of the cranked Nilsson-Strutinsky approach.

  20. SU(2s+1) symmetry and nonlinear dynamics of high spin magnets

    SciTech Connect

    Kovalevsky, M.Y. Glushchenko, A.V.

    2014-10-15

    The article is devoted to the description of dynamics of magnets with arbitrary spin on the basis of the Hamiltonian formalism. The relationship of quantum states and magnetic degrees of freedom has been considered. Subalgebras of Poisson bracket of magnetic values for spin s=1/2; 1; 3/2 have been established. We have obtained non-linear dynamic equations for the normal and degenerate non-equilibrium states of high-spin magnets with the SO(3), SU(4), SU(2)×SU(2), SU(3), SO(4), SO(5) symmetries of exchange interaction. The connection between models of magnetic exchange energy and the Casimir invariants has been discussed.

  1. Charge transfer to ground-state ions produces free electrons

    NASA Astrophysics Data System (ADS)

    You, D.; Fukuzawa, H.; Sakakibara, Y.; Takanashi, T.; Ito, Y.; Maliyar, G. G.; Motomura, K.; Nagaya, K.; Nishiyama, T.; Asa, K.; Sato, Y.; Saito, N.; Oura, M.; Schöffler, M.; Kastirke, G.; Hergenhahn, U.; Stumpf, V.; Gokhberg, K.; Kuleff, A. I.; Cederbaum, L. S.; Ueda, K.

    2017-01-01

    Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-energy free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic ground state. In our experiment, we observe the decay of Ne2+ produced after Ne 1s photoionization in Ne-Kr mixed clusters.

  2. Charge transfer to ground-state ions produces free electrons

    PubMed Central

    You, D.; Fukuzawa, H.; Sakakibara, Y.; Takanashi, T.; Ito, Y.; Maliyar, G. G.; Motomura, K.; Nagaya, K.; Nishiyama, T.; Asa, K.; Sato, Y.; Saito, N.; Oura, M.; Schöffler, M.; Kastirke, G.; Hergenhahn, U.; Stumpf, V.; Gokhberg, K.; Kuleff, A. I.; Cederbaum, L. S.; Ueda, K

    2017-01-01

    Inner-shell ionization of an isolated atom typically leads to Auger decay. In an environment, for example, a liquid or a van der Waals bonded system, this process will be modified, and becomes part of a complex cascade of relaxation steps. Understanding these steps is important, as they determine the production of slow electrons and singly charged radicals, the most abundant products in radiation chemistry. In this communication, we present experimental evidence for a so-far unobserved, but potentially very important step in such relaxation cascades: Multiply charged ionic states after Auger decay may partially be neutralized by electron transfer, simultaneously evoking the creation of a low-energy free electron (electron transfer-mediated decay). This process is effective even after Auger decay into the dicationic ground state. In our experiment, we observe the decay of Ne2+ produced after Ne 1s photoionization in Ne–Kr mixed clusters. PMID:28134238

  3. High Spin-Chern Insulators with Magnetic Order

    NASA Astrophysics Data System (ADS)

    Ezawa, Motohiko

    2013-12-01

    As a topological insulator, the quantum Hall (QH) effect is indexed by the Chern and spin-Chern numbers and . We have only in conventional QH systems. We investigate QH effects in generic monolayer honeycomb systems. We search for spin-resolved characteristic patterns by exploring Hofstadter's butterfly diagrams in the lattice theory and fan diagrams in the low-energy Dirac theory. It is shown that the spin-Chern number can takes an arbitrary high value for certain QH systems. This is a new type of topological insulators, which we may call high spin-Chern insulators. Samples may be provided by graphene on the SiC substrate with ferromagnetic order, transition-metal dichalcogenides with ferromagnetic order, transition-metal oxide with antiferromagnetic order and silicene with ferromagnetic order. Actually high spin-Chern insulators are ubiquitous in any systems with magnetic order. Nevertheless, the honeycomb system would provide us with unique materials for practical materialization.

  4. High Spin-Chern Insulators with Magnetic Order

    PubMed Central

    Ezawa, Motohiko

    2013-01-01

    As a topological insulator, the quantum Hall (QH) effect is indexed by the Chern and spin-Chern numbers and . We have only in conventional QH systems. We investigate QH effects in generic monolayer honeycomb systems. We search for spin-resolved characteristic patterns by exploring Hofstadter's butterfly diagrams in the lattice theory and fan diagrams in the low-energy Dirac theory. It is shown that the spin-Chern number can takes an arbitrary high value for certain QH systems. This is a new type of topological insulators, which we may call high spin-Chern insulators. Samples may be provided by graphene on the SiC substrate with ferromagnetic order, transition-metal dichalcogenides with ferromagnetic order, transition-metal oxide with antiferromagnetic order and silicene with ferromagnetic order. Actually high spin-Chern insulators are ubiquitous in any systems with magnetic order. Nevertheless, the honeycomb system would provide us with unique materials for practical materialization. PMID:24310394

  5. A Synthetic High-Spin Oxoiron(IV) Complex: Generation, Spectroscopic Characterization, and Reactivity

    SciTech Connect

    England, J.; Martinho, M; Farquhar, E; Frisch, J; Bominaar, E; Munck, E; Que, L

    2009-01-01

    The high-yield generation of a synthetic high-spin oxoiron(IV) complex, (Fe{sup IV}(O)(TMG{sub 3}tren)){sup 2+} (TMG{sub 3}tren = 1,1,1-tris{l_brace}2-(N2-(1,1,3,3-tetramethylguanidino))ethyl{r_brace}amine), has been achieved by using the very bulky tetradentate TMG{sub 3}tren ligand, in order to both sterically protect the oxoiron(IV) moiety and enforce a trigonal bipyramidal geometry at the iron center, for which an S=2 ground state is favored.

  6. Ferrimagnetic and Long Period Antiferromagnetic Phases in High Spin Heisenberg Chains with D-Modulation

    NASA Astrophysics Data System (ADS)

    Hida, Kazuo

    2007-02-01

    The ground state properties of the high spin Heisenberg chains with alternating single site anisotropy are investigated by means of the numerical exact daigonaization and DMRG method. It is found that the ferrimagnetic state appears between the Haldane phase and period doubled Néel phase for the integer spin chains. On the other hand, the transition from the Tomonaga-Luttinger liquid state into the ferrimagnetic state takes place for the half-odd-integer spin chains. In the ferrimagnetic phase, the spontaneous magnetization varies continuously with the modulation amplitude of the single site anisotropy. Eventually, the magnetization is locked to fractional values of the saturated magnetization. These fractional values satisfy the Oshikawa-Yamanaka-Affleck condition. The local spin profile is calculated to reveal the physical nature of each state. In contrast to the case of frustration induced ferrimagnetism, no incommensurate magnetic superstructure is found.

  7. Enhancement of high-spin collectivity in N = Z nuclei by the isoscalar neutron-proton pairing

    NASA Astrophysics Data System (ADS)

    Kaneko, K.; Sun, Y.; de Angelis, G.

    2017-01-01

    Pairing from different fermions, neutrons and protons, is unique in nuclear physics. The fingerprint for the isoscalar T = 0 neutron-proton (np) pairing has however remained a question. We study this exotic pairing mode in excited states of rotating N ≈ Z nuclei by applying the state-of-the-art shell-model calculations for 88Ru and the neighboring 90,92Ru isotopes. We show that the T = 0 np pairing is responsible for the distinct rotational behavior between the N = Z and N > Z nuclei. Our calculation suggests a gradual crossover from states with mixed T = 1 and T = 0 pairing near the ground state to those dominated by the T = 0 np pairing at high spins. It is found that the T = 0 np pairing plays an important role in enhancing the high-spin collectivity, thereby reducing shape variations along the N = Z line.

  8. Gross shell structure at high spin in heavy nuclei

    SciTech Connect

    Deleplanque, Marie-Agnes; Frauendorf, Stefan; Pashkevich, Vitaly V.; Chu, S.Y.; Unzhakova, Anja

    2003-10-07

    Experimental nuclear moments of inertia at high spins along the yrast line have been determined systematically and found to differ from the rigid-body values. The difference is attributed to shell effect and these have been calculated microscopically. The data and quantal calculations are interpreted by means of the semiclassical Periodic Orbit Theory. From this new perspective, features in the moments of inertia as a function of neutron number and spin, as well as their relation to the shell energies can be understood. Gross shell effects persist up to the highest angular momenta observed.

  9. Systematical study of high-spin rotational bands in neutron-deficient Kr isotopes by the extended projected shell model

    NASA Astrophysics Data System (ADS)

    Wu, Xin-Yi; Ghorui, S. K.; Wang, Long-Jun; Kaneko, K.; Sun, Yang

    2017-01-01

    We analyze the high-spin structure of the even-even 72-80Kr isotopes using the Projected Shell Model (PSM). With the help of the Pfaffian formulas, we have vigorously extended the quasi-particle (qp) basis of the PSM code and applied in this mass region for the first time. We consider a sufficiently large multi-qp configuration space in order to describe high-spin rotational behavior. The results show that the calculation can reproduce most of the known rotational bands with positive- or negative-parity. Moreover, some side bands appearing in the near-yrast region are predicted. The main structure for each band is discussed in terms of multi-qp configurations. The variations in moment of inertia with spin are explained in terms of successive band crossings among the 2-qp, 4-qp, 6-qp, and 8-qp states. The B (E 2) transition probabilities in these bands are also calculated. To further understand the high-spin behavior of these neutron-deficient nuclei and to confirm predictions of the present work, good high-spin data, especially for B (E 2) transitions, are called for.

  10. Cancer mortality in four northern wheat-producing states.

    PubMed Central

    Schreinemachers, D M

    2000-01-01

    Chlorophenoxy herbicides are used both in cereal grain agriculture and in nonagricultural settings such as right-of-ways, lawns, and parks. Minnesota, North Dakota, South Dakota, and Montana grow most of the spring and durum wheat produced in the United States. More than 90% of spring and durum wheat is treated with chlorophenoxy herbicides, in contrast to treatment of approximately 30% of winter wheat. In this ecologic study I used wheat acreage as a surrogate for exposure to chlorophenoxy herbicides. I investigated the association of chlorophenoxy herbicides with cancer mortality during 1980-1989 for selected counties based on level of agriculture ([greater and equal to] 20%) and rural population ([greater and equal to] 50%). Age-standardized cancer mortality rates were determined for grouped counties based on tertiles of wheat acreage per county or for individual counties for frequently occurring cancers. The cancer sites that showed positive trends of increasing cancer mortality with increasing wheat acreage were esophagus, stomach, rectum, pancreas, larynx, prostate, kidney and ureter, brain, thyroid, bone, and all cancers (men) and oral cavity and tongue, esophagus, stomach, liver and gall bladder and bile ducts, pancreas, cervix, ovary, bladder, and other urinary organs, and all cancers (women). Rare cancers in men and women and cancers in boys and girls were studied by comparing counties above and below the median of wheat acreage per county. There was increased mortality for cancer of the nose and eye in both men and women, brain and leukemia in both boys and girls, and all cancers in boys. These results suggest an association between cancer mortality and wheat acreage in counties of these four states. PMID:11017893

  11. Experimental investigation of shell-model excitations of 89Zr up to high spin

    NASA Astrophysics Data System (ADS)

    Saha, S.; Palit, R.; Sethi, J.; Trivedi, T.; Srivastava, P. C.; Kumar, S.; Naidu, B. S.; Donthi, R.; Jadhav, S.; Biswas, D. C.; Garg, U.; Goswami, A.; Jain, H. C.; Joshi, P. K.; Mukherjee, G.; Naik, Z.; Nag, S.; Nanal, V.; Pillay, R. G.; Saha, S.; Singh, A. K.

    2012-09-01

    Near yrast states in 89Zr were investigated up to high spin using the fusion evaporation reaction 80Se(13C, 4n) at an incident beam energy of 50 MeV. Excited levels of 89Zr have been observed up to ˜10 MeV excitation energy and spin ˜37/2ℏ using the prompt gamma spectroscopy technique with the Indian National Gamma Array (INGA). The angular distribution, directional correlation, and polarization measurements were carried out to assign the spin and parity of the newly reported states. The structures of both the positive and negative parity states up to highest spin observed in the present experiment have been compared with shell-model calculations using two recently developed residual interactions, JUN45 and jj44b. The role of proton excitations from p3/2 and f5/2 orbitals to the g9/2 orbital for the higher spin states has been discussed.

  12. High spin-Chern insulators with magnetic order.

    PubMed

    Ezawa, Motohiko

    2013-12-06

    As a topological insulator, the quantum Hall (QH) effect is indexed by the Chern and spin-Chern numbers C and Cspin. We have only Cspin = 0 or ± 1/2 in conventional QH systems. We investigate QH effects in generic monolayer honeycomb systems. We search for spin-resolved characteristic patterns by exploring Hofstadter's butterfly diagrams in the lattice theory and fan diagrams in the low-energy Dirac theory. It is shown that the spin-Chern number can takes an arbitrary high value for certain QH systems. This is a new type of topological insulators, which we may call high spin-Chern insulators. Samples may be provided by graphene on the SiC substrate with ferromagnetic order, transition-metal dichalcogenides with ferromagnetic order, transition-metal oxide with antiferromagnetic order and silicene with ferromagnetic order. Actually high spin-Chern insulators are ubiquitous in any systems with magnetic order. Nevertheless, the honeycomb system would provide us with unique materials for practical materialization.

  13. High-spin lifetime measurements in the N=Z nucleus {sup 72}Kr

    SciTech Connect

    Andreoiu, C.; Svensson, C. E.; Finlay, P.; Garrett, P. E.; Grinyer, G. F.; Hyland, B.; Phillips, A. A.; Schumaker, M. A.; Valiente-Dobon, J. J.; Afanasjev, A. V.; Austin, R. A. E.; Carpenter, M. P.; Freeman, S. J.; Greene, J.; Moore, F.; Mukherjee, G.; Seweryniak, D.; Dashdorj, D.; Goergen, A.

    2007-04-15

    High-spin states in the N=Z nucleus {sup 72}Kr have been populated in the {sup 40}Ca({sup 40}Ca, 2{alpha}){sup 72}Kr fusion-evaporation reaction at a beam energy of 165 MeV using the Gammasphere array for {gamma}-ray detection coupled to the Microball array for charged particle detection. The previously observed bands in {sup 72}Kr were extended to an excitation energy of {approx}24 MeV and angular momentum of 30({Dirac_h}/2{pi}). Using the Doppler shift attenuation method the lifetimes of high-spin states were measured for the first time. Excellent agreement between the results of calculations within the isovector mean field theory and experiment is observed both for rotational and deformation properties. No enhancement of quadrupole deformation expected in the presence of isoscalar t=0 np pairing is observed. Current data do not show any evidence for the existence of the isoscalar np pairing.

  14. Study of Electromagnetic Properties of Nuclei and Structural Changes at High Spins in Yb Isotopes

    NASA Astrophysics Data System (ADS)

    Mansour, N.; Awwad, Z.; Bayomy, T.; Diab, A.

    High-spin states of nuclei, populated by heavy-ion reactions, are of interest because they reveal changes in the structur of nuclei under stress. In the first part much of our insight into the structure of high-spin states is being provided by electromagnetic strength functions. In the second part, the level scheme of 158Yb has been extended to I = 37 by using the 98Mo (64Ni, 4n) reaction, and the backbending phenomena in Yb isotopes has been discussed.Translated AbstractUntersuchungen der elektromagnetischen Eigenschaften an Kernen von Yb-Isotopen und ihren Strukturänderungen bei hohem SpinDurch Schwerionenreaktionen erhaltene Kernzustände mit hohen Spinwerten sind von Interesse, weil sie Änderungen der Kernstruktur unter Beanspruchung aufzeigen. Ein Großteil unseres Verständnisses der Struktur dieser Zustände großen Spins resultiert aus den elektromagnetischen Feldstärkefunktionen. Wir erweitern das Zustandsschema von 158Yb bis zu I = 37 unter Benutzung der Reaktion 98Mo (64Ni, 4n) und diskutieren das Phänomen der Rückbiegung an Yb-Isotopen.

  15. High-spin isomers in neutron-rich nuclei studied with the TARDIS-array at IGISOL

    NASA Astrophysics Data System (ADS)

    Lhersonneau, G.; Butler, P. A.; Cocks, J. F. C.; Honkanen, A.; Huhta, M.; Jones, P. M.; Jokinen, A.; Julin, R.; Juutinen, S.; Lampinen, A.; Müller, D.; Mäkelä, E.; Oinonen, M.; Parmonen, J. M.; Piiparinen, M.; Savelius, A.; Smith, J. F.; Törmänen, S.; Virtanen, A.; Äystö, J.

    1996-02-01

    A 12 Compton-suppressed detector array TARDIS has been placed around the collection spot of the IGISOL separator, with the aim of studying decays of high-spin isomers in neutron-rich isotopes produced by fission. An experiment on 97Y shows that the detection limit is improved by more than one order of magnitude with respect to previous measurements at research reactors with conventional detector setups.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    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.

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

    PubMed

    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. Analysis of wind farm energy produced in the United States

    USDA-ARS?s Scientific Manuscript database

    The electricity generated by wind farms in almost every state in the United States with over 10 MW of wind turbine capacity was analyzed over a five-year period (2002 to 2006). The total amount of wind generated electricity in the United States for 2006 was estimated at 26.3 terawatt-hours which wa...

  19. High-spin level structure of {sup 115}Rh: Evolution of triaxiality in odd-even Rh isotopes

    SciTech Connect

    Liu, S. H.; Gelberg, A.; Gu, L.; Yeoh, E. Y.; Zhu, S. J.; Luo, Y. X.; Rasmussen, J. O.; Ma, W. C.; Daniel, A. V.; Oganessian, Yu. Ts.; Ter-Akopian, G. M.

    2011-07-15

    High-spin excited states in the neutron-rich nucleus {sup 115}Rh have been identified for the first time by studying prompt {gamma} rays from the spontaneous fission of {sup 252}Cf with the Gammasphere detector array. A new yrast band and a sideband are built in {sup 115}Rh. This level scheme is proposed to be built on the 7/2{sup +} ground state. The existence of a large signature splitting and an yrare band in {sup 115}Rh shows typical features of a triaxially deformed nucleus. The rigid triaxial rotor plus particle model is used to interpret the level structure of {sup 115}Rh. The level energies, the {gamma} branching ratios, the large signature splitting in the yrast band, and the inverted signature splitting in the yrare band in {sup 115}Rh are reproduced very well. Strong K mixing occurs in {sup 115}Rh at high spin.

  20. Competing decay modes of a high-spin isomer in the proton-unbound nucleus ¹⁵⁸Ta*

    SciTech Connect

    Carroll, R. J.; Page, R. D.; Joss, D. T.; Uusitalo, J.; Darby, I. G.; Andgren, K.; Cederwall, B.; Eeckhaudt, S.; Grahn, T.; Gray-Jones, C.; Greenlees, P. T.; Hadinia, B.; Jones, P. M.; Julin, R.; Juutinen, S.; Leino, M.; Leppänen, A. -P.; Nyman, M.; O'Donnell, D.; Pakarinen, J.; Rahkila, P.; Sandzelius, M.; Sarén, J.; Scholey, C.; Seweryniak, D.; Simpson, J.

    2015-01-01

    An isomeric state at high spin and excitation energy was recently observed in the proton-unbound nucleus 158Ta. This state was observed to decay by both α and γ decay modes. The large spin change required to decay via γ-ray emission incurs a lifetime long enough for α decay to compete. The α decay has an energy of 8644(11) keV, which is among the highest observed in the region, a partial half-life of 440(70) μs and changes the spin by 11ℏ. In this study, additional evidence supporting the assignment of this α decay to the high-spin isomer in 158Ta will be presented.

  1. Competing decay modes of a high-spin isomer in the proton-unbound nucleus ¹⁵⁸Ta*

    DOE PAGES

    Carroll, R. J.; Page, R. D.; Joss, D. T.; ...

    2015-01-01

    An isomeric state at high spin and excitation energy was recently observed in the proton-unbound nucleus 158Ta. This state was observed to decay by both α and γ decay modes. The large spin change required to decay via γ-ray emission incurs a lifetime long enough for α decay to compete. The α decay has an energy of 8644(11) keV, which is among the highest observed in the region, a partial half-life of 440(70) μs and changes the spin by 11ℏ. In this study, additional evidence supporting the assignment of this α decay to the high-spin isomer in 158Ta will bemore » presented.« less

  2. High-spin yrast structure of {sup 159}Ho

    SciTech Connect

    Ollier, J.; Simpson, J.; Riley, M. A.; Wang, X.; Aguilar, A.; Teal, C.; Paul, E. S.; Nolan, P. J.; Petri, M.; Rigby, S. V.; Thomson, J.; Unsworth, C.; Carpenter, M. P.; Janssens, R. V. F.; Lauritsen, T.; Zhu, S.; Darby, I. G.; Hartley, D. J.; Kondev, F. G.

    2011-08-15

    An investigation of the yrast structure of the odd-Z {sup 159}Ho nucleus to high spin has been performed. The {sup 159}Ho nucleus was populated by the reaction {sup 116}Cd({sup 48}Ca,p4n{gamma}) at a beam energy of 215 MeV, and resulting {gamma} decays were detected by the Gammasphere spectrometer. The h{sub 11/2} yrast band has been significantly extended up to I{sup {pi}=}75/2{sup -} (tentatively 79/2{sup -}). A lower frequency limit for the second (h{sub 11/2}){sup 2} proton alignment was extracted consistent with the systematics of this alignment frequency, indicating an increased deformation with neutron number in the Ho isotopes. The energy-level splitting between the signature partners in the h{sub 11/2} structures of the Ho isotopes and the neighboring N=92 isotones is discussed.

  3. NADH reduction of nitroaromatics as a probe for residual ferric form high-spin in a cytochrome P450.

    PubMed

    Pochapsky, Thomas C; Wong, Nathan; Zhuang, Yihao; Futcher, Jeffrey; Pandelia, Maria-Eirini; Teitz, Drew R; Colthart, Allison M

    2017-05-01

    The existence of a substrate-sensitive equilibrium between high spin (S=5/2) and low spin (S=1/2) ferric iron is a well-established phenomenon in the cytochrome P450 (CYP) superfamily, although its origins are still a subject of discussion. A series of mutations that strongly perturb the spin state equilibrium in the camphor hydroxylase CYP101A1 were recently described (Colthart et al., Sci. Rep. 6, 22035 (2016)). Wild type CYP101A1 as well as some CYP101A1 mutants are herein shown to be capable of catalyzing the reduction of nitroacetophenones by NADH to the corresponding anilino compounds (nitroreductase or NRase activity). The distinguishing characteristic between those mutants that catalyze the reduction and those that cannot appears to be the extent to which residual high spin form exists in the absence of the native substrate d-camphor, with those showing the largest spin state shifts upon camphor binding also exhibiting NRase activity. Optical and EPR spectroscopy was used to further examine these phenomena. These results suggest that reduction of nitroaromatics may provide a useful probe of residual high spin states in the CYP superfamily. This article is part of a Special Issue entitled: Cytochrome P450 biodiversity and biotechnology, edited by Erika Plettner, Gianfranco Gilardi, Luet Wong, Vlada Urlacher, Jared Goldstone. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Producing Hi-Tech: Globalization, the State and Migrant Subjects

    ERIC Educational Resources Information Center

    Kamat, Sangeeta; Mir, Ali; Mathew, Biju

    2004-01-01

    This paper examines the role of the state in the context of globalization. Taking up the specific case of Indian software engineers and their migration to the USA, the authors show the involvement of the Indian state and the US at different levels. The growth of the IT labour sector was based on changes in the higher education policy of the Indian…

  5. Producing Hi-Tech: Globalization, the State and Migrant Subjects

    ERIC Educational Resources Information Center

    Kamat, Sangeeta; Mir, Ali; Mathew, Biju

    2004-01-01

    This paper examines the role of the state in the context of globalization. Taking up the specific case of Indian software engineers and their migration to the USA, the authors show the involvement of the Indian state and the US at different levels. The growth of the IT labour sector was based on changes in the higher education policy of the Indian…

  6. 7 CFR 1216.21 - Primary peanut-producing states.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., Georgia, Mississippi, New Mexico, North Carolina, Oklahoma, South Carolina, Texas, and Virginia, Provided, these states maintain three-year average production of at least 10,000 tons of peanuts. ...

  7. Endothelin produces systemic vasodilation independent of the state of consciousness.

    PubMed

    Lippton, H L; Pellett, A; Cairo, J; Summer, W R; Lowe, R F; Sander, G E; Giles, T D; Cohen, G; Levitzky, M G

    1989-01-01

    The effects of endothelin, ET-1, on pulmonary and systemic hemodynamics were studied in the open chest dog and changes in systemic arterial pressure in dogs under conscious and anesthetized states were compared. Rapid intravenous (IV) bolus injections of ET-1, 100-1,000 nanograms/kg, significantly decreased systemic arterial pressure, and significantly decreased systemic vascular resistance whereas left atrial pressure and pulmonary vascular resistance were not altered. Reductions in systemic arterial pressure in response to bolus injection of ET-1, 100 and 300 nanograms/kg IV, during conscious state and during anesthesia were similar, respectively. The present data suggest that ET-1 dilates the systemic vascular bed independent of the animal's state of consciousness. The present data also suggest that when compared to the systemic vascular bed, the pulmonary vascular bed is less responsive to bolus administration of ET-1.

  8. Search for α-decay of high-spin isomers in rare-earth nuclei using a decay-in-flight technique

    SciTech Connect

    Vrba, Joseph A.

    1980-03-01

    An experimental search has been conducted for α-decay in the lifetime range of from 1 to 100 nsec in a variety of rare earth nuclei produced in reactions of 125 to 146 MeV /sup 16/O ions on targets of /sup 139/La, /sup 141/Pr, and /sup 142/Nd. The products of these reactions include systems in which high spin (I > 10 h-bar) isomeric states have been observed with lifetimes in the range studied. Certain of these isomers may be very high spin statistical yrast traps which have been predicted to occur at spins of from 30 to 50 h-bar in the rare earths. For such spins and lifetimes, calculations suggest that α-decay could be a major mode of de-excitation. The technique employed for these experimental investigations made use of a specially designed trajectory detector to observe α-decay directly from the reaction products which recoiled from a thin target. Analytical procedures developed for reduction of the decay-in-flight data are discussed which yielded information about the particle types detected, the energies of these particles, the trajectories followed, and the positions of parent nuclei at the time the detected particles were emitted. Kinematic and solid angle corrections are considered which permitted correction for Doppler broadening effects and allowed estimates to be made with regard to the lifetime and production cross section of the parent state. The experimental method and the associated analytical procedures were verified by study of α-decay following the reaction /sup 208/Pb(/sup 16/O,p6n)/sup 217/Ac. No system studied in the search for yrast trap α-decay showed activity significantly above background in the 6 to 16 MeV energy range.

  9. Odd tensor electric transitions in high-spin Sn-isomers and generalized seniority

    NASA Astrophysics Data System (ADS)

    Maheshwari, Bhoomika; Jain, Ashok Kumar

    2016-02-01

    The similar behavior of the B (E 1) values of the recently observed 13- odd tensor E1 isomers and the B (E 2) values of the 10+ and 15- even tensor E2 isomers in the Sn-isotopes has been understood in terms of the generalized seniority for multi-j orbits by using the quasi-spin scheme. This simple approach proves to be quite successful in explaining the measured transition probabilities and the corresponding half-lives in the high-spin isomers of the semi-magic Sn-isotopes. Hence, we show for the first time the occurrence of seniority isomers in the 13- Sn-isomers, which decay by odd-tensor E1 transitions to the same seniority states.

  10. High-spin nuclear structure studies with radioactive ion beams

    SciTech Connect

    Baktash, C.

    1992-12-31

    Two important developments in the sixties, namely the advent of heavy-ion accelerators and fabrication of Ge detectors, opened the way for the experimental studies of nuclear properties at high angular momentum. Addition of a new degree of freedom, namely spin, made it possible to observe such fascinating phenomena as occurrences and coexistence of a variety of novel shapes, rise, fall and occasionally rebirth of nuclear collectivity, and disappearance of pairing correlations. Today, with the promise of development of radioactive ion beams (RIB) and construction of the third-generation Ge-detection systems (GAMMASPHERE and EUROBALL), the authors are poised to explore new and equally fascinating phenomena that have been hitherto inaccessible. With the addition of yet another dimension, namely the isospin, they will be able to observe and verify predictions for exotic shapes as varied as rigid triaxiality, hyperdeformation and triaxial octupole shapes, or to investigate the T = 0 pairing correlations. In this paper, they shall review, separately for neutron-deficient and neutron-rich nuclei, these and a few other new high-spin physics opportunities that may be realized with RIB. Following this discussion, they shall present a list of the beam species, intensities and energies that are needed to fulfill these goals. The paper will conclude with a description of the experimental techniques and instrumentations that are required for these studies.

  11. (Evolution of nuclear collectivity at high spins and temperatures)

    SciTech Connect

    Baktash, C.

    1989-09-28

    The traveler attended and presented an invited talk entitled Evolution of nuclear collectivity at high spins and temperatures'' at the XII Workshop on Nuclear Physics at Iguazu Falls, Argentina. Following the conference, the traveler visited the TANDAR Laboratory in Buenos Aires, Argentina, for two weeks. This trip was the first by one of the principal investigators of an ORNL-TANDAR exchange program that was recently approved and funded by the NSF. The results of the extensive consultations that the traveler had with his Argentine collaborators, A. J. Kreiner and G. Garcia-Bermudez, can be summarized as follows: (1) discussed the spectroscopy work on several nuclei of common interest that are being studied at the two laboratories, (2) agreed on the first joint experiments to be performed at the Holifield and TANDAR facilities, (3) developed a tentative timetable for the future visits by both groups, and (4) continued with the analysis of data on {sup 82}Sr taken earlier at ORNL in collaboration with Dr. Garcia-Bermudez.

  12. Recent advances in the study of hyperdeformation at high spin

    NASA Astrophysics Data System (ADS)

    Abusara, Hazem; Afanasjev, A. V.

    2008-10-01

    The systematic investigation of hyperdeforation (HD) at high spin in the Z=40-58 part of nuclear chart has been performed in the framework of the cranked relativistic mean field theory. The properties of the HD bands such as quadrupole transition moments Qt, dynamic J^(2) and kinematic J^(1) moments of inertia have been studied. These observables are affected by centrifugal stretching. Our self-consistent calculations suggest that necking degree of freedom should play an important role in some nuclei at hyperdeformation. It is especially pronounced in the proton density distribution due to the repulsive Coulomb force. The density of the HD bands is high in the spin range where they are yrast or close to yrast in the majority of cases. In these cases the observation of discrete HD bands will most likely be impossible because the feeding intensity will be redistributed among many bands, thus, dropping below the observational limit of the experimental facilities. The calculations indicate Cd isotopes as the best candidates for a search of discrete HD bands. The HD configurations become yrast at lower spins in neutron-deficient nuclei than in the ones of the valley of β-stability. [1] W.Koepf and P.Ring, Nucl. Phys. A511, 279(1990), [2] A.V.Afanasjev and H.Abusara (submitted to Physical Review C)

  13. Magnetic circular dichroism of symmetry and spin forbidden transitions of high-spin metal ions

    NASA Astrophysics Data System (ADS)

    Oganesyan, Vasily S.; Thomson, Andrew J.

    2000-09-01

    Recently we have developed a general method of analyzing magnetic circular dichroism (MCD) spectra and magnetization curves of high-spin metal ions for spin-allowed transitions [Oganesyan et al., J. Chem. Phys. 110, 762 (1999)]. In the present article this approach is extended to cover the cases of spin- and symmetry-forbidden transitions. At high ligand fields many low-energy ligand field transitions become spin-forbidden. Extraction of information content about the electronic structure of the ground state can be obtained through the analysis and correlation of the positions, signs, and intensities of the MCD bands and magnetization curves of these transitions. The casting of the theory in terms of the irreducible tensor method allows full advantage to be taken of any symmetry elements and simplifies multielectron calculations. The theory is valid over the entire range of magnetic field strength and, therefore, allows the information content of spectra over the full field and temperature range to be exploited. The method is applied to the analysis of the recorded MCD spectra and magnetization curves of the lowest energy spin-forbidden ligand field transitions of pseudo-tetrahedral high-spin Fe(III), S=5/2, in the protein rubredoxin from Methanobacterium thermoautotrophicum (strain Marburg). The predicted signs, intensities, and magnetization curves for these transitions are in excellent agreement with experimental data. We also show that when the anisotropy of the ground state is larger than the Zeeman splitting the MCD of both spin-forbidden and allowed transitions can become comparable in magnitude. Hence caution is needed in order to avoid the misinterpretation of experimental results.

  14. A new architecture for high spin organics based on Baird's rule of 4n electron triplet aromatics.

    PubMed

    Mauksch, Michael; Tsogoeva, Svetlana B

    2017-02-08

    Due to the absence of open subshells (unlike transition metal compounds), stable high spin organic molecules are rare and are mostly limited to states of low multiplicity. As an alternative to high multiplicity polyradicals and polycarbenes, with their small energetic separation of different spin isomers, it is demonstrated that Baird's rule of 4n electron aromaticity in the triplet electronic state allows, in principle, the design of polycyclic high spin organics with high spin multiplicity in the electronic ground state and a large energetic separation for other spin states. Energy spacing between spin isomers is dictated here by the aromaticity or antiaromaticity of individual cycles (taking into account all π electrons), rather than by a spin Hamiltonian alone (accounting only for unpaired spin electrons). As a proof of concept, dyads of the cyclopentadienyl cation (which has been reported to possess a triplet ground state) have been computationally found to possess a quintet electronic ground state with two ferromagnetically coupled Baird aromatic rings (with SCF-GIAO NICS(0) = -4.6 and -4.4, respectively; "NICS" is "nucleus independent chemical shift") at the CASMP2(8,10)/6-311G*//CASSCF(8,10)/6-311G* level, which is 48.3 kcal mol(-1) lower in energy than the C2 open shell singlet with two antiaromatic rings (with NICS = +17.4), and 19.7 kcal mol(-1) below the triplet which has one aromatic and one antiaromatic ring, with NICS = -4.8 and +45.0, respectively. Triads of the cyclopentadienyl cation in linear and branched topologies are also proposed to be ground states of maximum spin multiplicity by computations at the DFT and CCSD(T)/6-31G//UB3LYP/6-311G* levels.

  15. Explosively produced megagauss fields and recent solid state applications

    SciTech Connect

    Fowler, C.M.; Freeman, B.L.; Hults, W.L.; King, J.C.; Mueller, F.M.; Rickel, D.G.; Smith, J.L.; Brooks, J.S.; Goettee, J.D.

    1993-12-31

    Large magnetic fields may be generated by compression of an initial magnetic flux generated over a large area at relatively low magnetic field into a region of smaller area. Following a discussion of flux compression principles, the authors discuss megagauss field systems in use at Los Alamos where chemical explosives are used to compress the flux. Their use in some solid state experiments will be discussed briefly, including a planned set of experiments on YBCO to be done jointly with a Russian team, whose aim is to determine the low temperature, critical magnetic field of YBCO.

  16. 19 CFR 191.183 - Articles manufactured or produced in the United States.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Articles manufactured or produced in the United... From Customs Territory § 191.183 Articles manufactured or produced in the United States. (a) Procedure... shall be followed as applicable to drawback under this subpart on articles manufactured or produced...

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

    DOE PAGES

    Staszczak, A.; Wong, Cheuk-Yin

    2016-05-11

    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.

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

    SciTech Connect

    Staszczak, A.; Wong, Cheuk-Yin

    2016-05-11

    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.

  19. High-spin ribbons and antiferromagnetic ordering of a Mn(II)-biradical-Mn(II) complex.

    PubMed

    Fatila, Elisabeth M; Clérac, Rodolphe; Rouzières, Mathieu; Soldatov, Dmitriy V; Jennings, Michael; Preuss, Kathryn E

    2013-09-11

    A binuclear metal coordination complex of the first thiazyl-based biradical ligand 1 is reported (1 = 4,6-bis(1,2,3,5-dithiadiazolyl)pyrimidine; hfac =1,1,1,5,5,5,-hexafluoroacetylacetonato-). The Mn(hfac)2-biradical-Mn(hfac)2 complex 2 is a rare example of a discrete, molecular species employing a neutral bridging biradical ligand. It is soluble in common organic solvents and can be easily sublimed as a crystalline solid. Complex 2 has a spin ground state of S(T) = 4 resulting from antiferromagnetic coupling between the S(birad) = 1 biradical bridging ligand and two S(Mn) = 5/2 Mn(II) ions. Electrostatic contacts between atoms with large spin density promote a ferromagnetic arrangement of the moments of neighboring complexes in ribbon-like arrays. Weak antiferromagnetic coupling between these high-spin ribbons stabilizes an ordered antiferromagnetic ground state below 4.5 K. This is an unusual example of magnetic ordering in a molecular metal-radical complex, wherein the electrostatic contacts that direct the crystal packing are also responsible for providing an efficient exchange coupling pathway between molecules.

  20. High-spin structure and multiphonon {gamma} vibrations in very neutron-rich {sup 114}Ru

    SciTech Connect

    Yeoh, E. Y.; Wang, J. G.; Ding, H. B.; Gu, L.; Xu, Q.; Xiao, Z. G.; Zhu, S. J.; Hamilton, J. H.; Li, K.; Ramayya, A. V.; Hwang, J. K.; Liu, Y. X.; Liu, S. H.; Sheikh, J. A.; Bhat, G. H.; Luo, Y. X.; Rasmussen, J. O.; Lee, I. Y.; Ma, W. C.

    2011-05-15

    High-spin levels of the neutron-rich {sup 114}Ru have been investigated by measuring the prompt {gamma} rays in the spontaneous fission of {sup 252}Cf. The ground-state band and one-phonon {gamma}-vibrational band have been extended up to 14{sup +} and 9{sup +}, respectively. Two levels are proposed as the members of a two-phonon {gamma}-vibrational band. A back bending (band crossing) has been observed in the ground-state band at ({h_bar}/2{pi}){omega}{approx_equal} 0.40 MeV. Using the triaxial deformation parameters, the cranked shell model calculations indicate that this back bending in {sup 114}Ru should originate from the alignment of a pair of h{sub 11/2} neutrons. Triaxial projected shell model calculations for the {gamma}-vibrational band structures of {sup 114}Ru are in good agreement with the experimental data. However, when using the oblate deformation parameters, both of the above-calculated results are not in agreement with the experimental data.

  1. Medium- and high-spin band structure of the chiral candidate 132La

    NASA Astrophysics Data System (ADS)

    Kuti, I.; Timár, J.; Sohler, D.; Paul, E. S.; Starosta, K.; Astier, A.; Bazzacco, D.; Bednarczyk, P.; Boston, A. J.; Buforn, N.; Chantler, H. J.; Chiara, C. J.; Clark, R. M.; Cromaz, M.; Descovich, M.; Dombrádi, Zs.; Fallon, P.; Fossan, D. B.; Fox, C.; Gizon, A.; Gizon, J.; Hecht, A. A.; Kintz, N.; Koike, T.; Lee, I. Y.; Lunardi, S.; Macchiavelli, A. O.; Nolan, P. J.; Nyakó, B. M.; Petrache, C. M.; Sampson, J. A.; Scraggs, H. C.; Tornyi, T. G.; Wadsworth, R.; Walker, A.; Zolnai, L.

    2013-04-01

    Medium- and high-spin states of 132La have been studied based on the data obtained from 100Mo(36S,p3n) and 116Cd(23Na,α3n) fusion-evaporation reactions using the EUROBALL and Gammasphere detector arrays, respectively. Triple-γ coincidence relations, angular correlations, and linear polarizations of the observed γ transitions have been deduced. The level scheme of 132La has been considerably extended, and unambiguous spin and parity values have been assigned to most of the excited states. The configuration of one of the bands is πg7/2(h11/2)2νh11/2 instead of the previously thought πh11/2νh11/2; thus its previously suggested magnetic rotational character cannot be upheld. The observed similarities between the level structures of 132La and 134Pr suggest the possible existence of a third πh11/2νh11/2 band in 132La that may show chiral features.

  2. Isospin symmetry breaking at high spin in the mirror nuclei {sup 35}Ar and {sup 35}Cl

    SciTech Connect

    Della Vedova, F.; Lenzi, S. M.; Bazzacco, D.; Brandolini, F.; Farnea, E.; Lunardi, S.; Menegazzo, R.; Nespolo, M.; Pavan, P.; Alvarez, C. Rossi; Venturelli, R.; Ionescu-Bujor, M.; Bucurescu, D.; Iordachescu, A.; Marginean, N.; Axiotis, M.; Martinez, T.; Napoli, D. R.; Bizzeti-Sona, A. M.; Bizzeti, P. G.

    2007-03-15

    High-spin states in {sup 35}Ar and {sup 35}Cl have been populated in the {sup 24}Mg({sup 16}O, {alpha}n) and {sup 24}Mg({sup 16}O, {alpha}p) reactions, respectively, at a beam energy of 70 MeV. The comparison between the level schemes of these mirror nuclei shows a striking asymmetry in the population yield of high-spin analog states of positive parity, which indicates different intensities of E1 transitions connecting positive- and negative-parity structures in both nuclei. Large energy differences are observed between analog states of negative parity with configurations of dominant pure single-particle character. This results from the comparison with large-scale shell-model calculations in the s{sub 1/2}d{sub 3/2}f{sub 7/2}p{sub 3/2} valence space. It is shown that important contributions to the energy differences arise from the multipole Coulomb and the relativistic electromagnetic spin-orbit interactions.

  3. Systematics of high spin to low spin crossovers across the RCoO3 family

    NASA Astrophysics Data System (ADS)

    Topsakal, M.; Shukla, G.; Wentzcovitch, R. M.

    2016-12-01

    Using density functional theory plus self-consistent Hubbard U (DFT+Usc ) calculations, we have investigated the spin crossover phenomenon observed in rare-earth cobaltites RCoO3 (R = Pr - Lu). Previous DFT studies of this series focused on structural and electronic structure variations across the RCoO3 series in which all Co3+ ions are kept in low-spin (LS) state (S=0). Here we manage to stabilize Co3+ ions in the high-spin (HS) state and perform thermodynamics calculations to predict their HS to LS phase diagrams. We show that the early stage of thermally induced spin crossover in RCoO 3 can be successfully described by introducing a carefully and legitimately chosen Hubbard U for the HS Co3+. The spin excitation energy (ΔE), as the energy difference of HS and LS states, is calculated across the series. Our calculations show that ΔE increases from PrCoO3 to LuCoO3 in agreement with the increase of spin-state transition temperature observed in experiments. We also observed that the Co3+ octahedral volume (or Co-O bond lengths) significantly increases upon excitation into the HS state and we also relate this volume change to ΔE. The octahedral volume expansion (ΔV) increases from PrCoO3 to LuCoO3 : the larger the volume expansion to accommodate HS, the larger the energy required to excite from LS to HS. Furthermore, the Hubbard U parameters presented in this work allow more accurate predictive DFT+U studies on RCoO3 perovskites, especially their magnetic properties.

  4. High-spin study of the shell model nucleus 88Y49

    NASA Astrophysics Data System (ADS)

    Bunce, M.; Regan, P. H.; Werner, V.; Beausang, C. W.; Anagnostatou, V.; Bowry, M.; Casperson, R. J.; Chen, D.; Cooper, N.; Goddard, P. M.; Hughes, R. O.; Ilie, G.; Mason, P. J. R.; Pauerstein, B.; Reed, M. W.; Ross, T. J.; Simpson, E. C.

    2013-04-01

    The near-yrast structure of the near-magic, odd-odd nucleus, 3988Y49, has been studied into the high-spin regime. Investigations were performed at the Wright Nuclear Structure Laboratory, Yale University, using the 74Ge(18O,p3n) and 76Ge(18O,p5n) fusion-evaporation reactions at beam energies of 60 and 90 MeV, respectively. Gamma-ray energy coincidence analyses using both double (γ2) and triple (γ3) fold coincidences, together with angular correlation measurements, have been used to extend the previously reported level scheme to an excitation energy of 8.6 MeV and a spin and parity of 19(-). The presented level scheme is compared with predictions of a truncated valence space shell-model calculation, which assumes an inert 56Ni core with proton and neutron excitations allowed within the f5/2, p3/2, p1/2, and g9/2 single-particle states. The shell-model calculations show a reasonable comparison with the experimental data for the yrast, positive-parity states up to spin 18 ℏ, with larger variations evident for negative-parity states with spins greater than 16 ℏ. In spite of a significant increase in angular momentum input associated with the thin target 76Ge(18O,p5n) reaction channel, as compared to the backed target data using the 74Ge target, no additional discrete states were identified in the former data set, suggesting that the level scheme for this nucleus fragments significantly above the observed states, possibly indicating cross-shell excitations becoming dominant for I>19 ℏ.

  5. Femtosecond time-resolved optical and Raman spectroscopy of photoinduced spin crossover: temporal resolution of low-to-high spin optical switching.

    PubMed

    Smeigh, Amanda L; Creelman, Mark; Mathies, Richard A; McCusker, James K

    2008-10-29

    A combination of femtosecond electronic absorption and stimulated Raman spectroscopies has been employed to determine the kinetics associated with low-spin to high-spin conversion following charge-transfer excitation of a FeII spin-crossover system in solution. A time constant of tau = 190 +/- 50 fs for the formation of the 5T2 ligand-field state was assigned based on the establishment of two isosbestic points in the ultraviolet in conjunction with changes in ligand stretching frequencies and Raman scattering amplitudes; additional dynamics observed in both the electronic and vibrational spectra further indicate that vibrational relaxation in the high-spin state occurs with a time constant of ca. 10 ps. The results set an important precedent for extremely rapid, formally forbidden (DeltaS = 2) nonradiative relaxation as well as defining the time scale for intramolecular optical switching between two electronic states possessing vastly different spectroscopic, geometric, and magnetic properties.

  6. High-spin Fe2+ and Fe3+ in single-crystal aluminous bridgmanite in the lower mantle

    NASA Astrophysics Data System (ADS)

    Lin, Jung-Fu; Mao, Zhu; Yang, Jing; Liu, Jin; Xiao, Yuming; Chow, Paul; Okuchi, Takuo

    2016-07-01

    Spin and valence states of iron in single-crystal bridgmanite (Mg0.89Fe0.12Al0.11Si0.89O3) are investigated using X-ray emission and Mössbauer spectroscopies with laser annealing up to 115 GPa. The results show that Fe predominantly substitutes for Mg2+ in the pseudo-dodecahedral A site, in which 80% of the iron is Fe3+ that enters the lattice via the charge-coupled substitution with Al3+ in the octahedral B site. The total spin momentum and hyperfine parameters indicate that these ions remain in the high-spin state with Fe2+ having extremely high quadrupole splitting due to lattice distortion. (Al,Fe)-bearing bridgmanite is expected to contain mostly high-spin, A-site Fe3+, together with a smaller amount of A-site Fe2+, that remains stable throughout the region. Even though the spin transition of B-site Fe3+ in bridgmanite was reported to cause changes in its elasticity at high pressures, (Fe,Al)-bearing bridgmanite with predominantly A-site Fe will not exhibit elastic anomalies associated with the spin transition.

  7. Spectroscopy and high-spin structure of {sup 209}Fr

    SciTech Connect

    Dracoulis, G. D.; Davidson, P. M.; Lane, G. J.; Kibedi, T.; Nieminen, P.; Watanabe, H.; Byrne, A. P.; Wilson, A. N.

    2009-05-15

    Excited states in {sup 209}Fr have been studied using the {sup 197}Au({sup 16}O,4n){sup 209}Fr reaction with pulsed beams and {gamma}-ray and electron spectroscopy. A comprehensive scheme has been established up to an excitation energy of about 6 MeV and spins of about 49/2({Dirac_h}/2{pi}). Several isomers have been identified including a J{sup {pi}}=25/2{sup +}, {tau}=48(3) ns state at 2130 keV and a 606(26) ns, 45/2{sup -} state at 4660 keV. The latter state decays via an enhanced E3 transition with a strength of 28.8(12) W.u. It can be identified with a similar isomer in the heavier odd isotopes {sup 211}Fr and {sup 213}Fr, arising from the maximal coupling of the five valence protons in the {pi}h{sub 9/2}{sup 3}i{sub 13/2}{sup 2} configuration. The systematics of the yrast states in the odd-A isotopes are discussed, including the presence of states arising from the main proton configurations coupled to the p{sub 1/2}, f{sub 5/2}, and i{sub 13/2} neutron holes. Shell-model configurations are assigned to many of the observed states. The isotopic assignment differs from earlier work, which is shown to be erroneous.

  8. Kondo effect and spin quenching in high-spin molecules on metal substrates

    NASA Astrophysics Data System (ADS)

    Jacob, D.; Soriano, M.; Palacios, J. J.

    2013-10-01

    Using a state-of-the art combination of density functional theory and impurity solver techniques, we present a complete and parameter-free picture of the Kondo effect in the high-spin (S=3/2) coordination complex known as manganese phthalocyanine adsorbed on the Pb(111) surface. We calculate the correlated electronic structure and corresponding tunnel spectrum and find an asymmetric Kondo resonance, as recently observed in experiments. Contrary to previous claims, the Kondo resonance stems from only one of three possible Kondo channels with origin in the Mn 3d orbitals, its peculiar asymmetric shape arising from the modulation of the hybridization due to a strong coupling to the organic ligand. The spectral signature of the second Kondo channel is strongly suppressed as the screening occurs via the formation of a many-body singlet with the organic part of the molecule. Finally, a spin-1/2 in the 3d shell remains completely unscreened due to the lack of hybridization of the corresponding orbital with the substrate, hence leading to a spin-3/2 underscreened Kondo effect.

  9. Normal and superdeformed high-spin structures in {sup 161}Lu

    SciTech Connect

    Bringel, P.; Huebel, H.; Al-Khatib, A.; Buerger, A.; Nenoff, N.; Neusser-Neffgen, A.; Schoenwasser, G.; Singh, A.K.; Hagemann, G.B.; Herskind, B.; Jensen, D.R.; Sletten, G.; Bednarczyk, P.; Curien, D.; Joss, D.T.; Simpson, J.; Gangopadhyay, G.; Kroell, Th.; Lo Bianco, G.; Petrache, C.M.

    2006-05-15

    High-spin states in {sup 161}Lu were populated in the {sup 139}La({sup 28}Si, 6n) reaction and {gamma}-ray coincidences were measured with the EUROBALL spectrometer. On the basis of these data, the previously known level scheme is extended with new band structures and is partly revised. Configuration assignments are made to all bands based on comparison of experimental properties with cranked shell model calculations. A strongly populated band with parity and signature ({pi},{alpha})=(+,-1/2) is found to be yrast above spin I{approx_equal}33. This band shows characteristics resembling those of two triaxial superdeformed bands in this nucleus based on the occupation of the shape-driving i{sub 13/2} proton orbital. This structure, unique to {sup 161}Lu within the chain of even-N Lu isotopes, is discussed in terms of a quasiparticle configuration in a local triaxial minimum with a larger triaxiality and a smaller quadrupole deformation than calculated for the i{sub 13/2} proton excitation.

  10. Semi-decoupled band and other high-spin band structures in 188Pt

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, S.; Biswas, D. C.; Tandel, S. K.; Frauendorf, S.; Danu, L. S.; Prashanth, P. N.; Joshi, B. N.; Prajapati, G. K.; John, B. V.; Nag, Somnath; Trivedi, T.; Saha, S.; Sethi, J.; Palit, R.; Joshi, P. K.

    2017-07-01

    High-spin states in the 188Pt nucleus have been investigated employing the 174Yb(18O,4 n )188Pt reaction. The level scheme has been significantly extended with the addition of several new γ rays. The Indian National Gamma Array (INGA) spectrometer consisting of eighteen clover Ge detectors facilitated angular correlation and linear polarization measurements for spin-parity assignment of levels. The Iπ=5- semi-decoupled band has been investigated in detail, and the long-standing ambiguity regarding the correct ordering of associated γ rays is now removed with the new observation of transitions linking the even-spin levels to the odd-spin ones. A weak, Δ I =2 sequence of γ rays with alignment and moment of inertia similar to the yrast, even-spin, rotation-aligned neutron i13 /2 band has been newly observed. Cranking calculations suggest that this new odd-spin sequence arises from the excitation of a valence quasineutron to the next i13 /2 level.

  11. Evidence for coexisting prolate and near-oblate shapes at high spin in 125Cs

    NASA Astrophysics Data System (ADS)

    Sun, Ji; Komatsubara, Tetsuro; Wang, Jia-Qi; Guo, Hao; Hu, Xue-Yuan; Ma, Ying-Jun; Liu, Yun-Zuo; Furuno, Kohei

    2016-12-01

    Excited states in the odd-proton nucleus 125Cs were investigated by means of in-beam γ -ray spectroscopy. The πg7/2 band is observed to fork into a ΔI = 1 coupled band and a ΔI = 2 decoupled band at high spins. To assign the possible configurations of these two bands, experimental B(M1)/B(E2) ratios and signature splittings have been evaluated for the ΔI = 1 band, and calculations based on the geometrical model, cranked shell model and total Routhian surfaces model have been performed. They are suggested to be a near-oblate band built on the (πg7/2/d5/2) ⊗ (νh11/2)2 configuration and a prolate band built on the πg7/2 ⊗ (πh11/2)2 configuration, respectively. Supported in part by National Natural Science Foundation of China (11475072)

  12. High-Spin Studies Of N˜Z Nuclei In The Mass 70 Region

    NASA Astrophysics Data System (ADS)

    Kelsall, N. S.; Svensson, C. E.; Fischer, S.; Appelbe, D. E.; Austin, R. A. E.; Balamuth, D. P.; Ball, G. C.; Cameron, J. A.; Carpenter, M. P.; Clark, R. M.; Cromaz, M.; Deleplanque, M. A.; Diamond, R. M.; Durell, J. L.; Fallon, P.; Freeman, S. J.; Hausladen, P. A.; Hodgson, D. F.; Janssens, R. V. F.; Jenkins, D. G.; Lane, G. J.; Leddy, M. J.; Lister, C. J.; Macchiavelli, A. O.; O'Leary, C. D.; Sarantites, D. G.; Stephens, F. S.; Schmidt, D. C.; Seweryniak, D.; Varley, B. J.; Vincent, S.; Vetter, K.; Waddington, J. C.; Wadsworth, R.; Ward, D.; Wilson, A. N.; Afanasjev, A. V.; Frauendorf, S.; Ragnarsson, I.; Wyss, R.

    2003-03-01

    High-spin states have been studied in 72,73Kr using 40Ca+40Ca and 36Ar+40Ca reactions at 160, 164 and 145 MeV respectively. The properties and configurations of the bands observed are interpreted with the aid of unpaired cranked Nilsson-Strutinsky/ cranked relativistic mean-field calculations and paired total routhian surface and cranked relativistic Hartree-Bogoliubov calculations. In 73Kr the three previously known structures have been extended to a spin of ˜30ℏ and a fourth structure, which is believed to be the signature partner to the g9/2 band, has been identified. The negative parity bands show evidence for an unusual type of band crossing. It is currently unclear whether this is a consequence of T=0 n-p pairing. At the highest spins the unpaired calculations can reproduce the observed data, suggesting that there is little evidence for pairing correlations in this spin regime. In 72Kr a new band has been identified that has the properties expected from the missing doubly aligned S-band configuration. The properties of this band can be reproduced by the unpaired CNS/ CRMF calculations, again suggesting that the structure has little pairing. However, paired calculations appear to be necessary to reproduce the properties of the previously known structure in this nucleus. The 72Kr results are also compared with projected shell model calculations.

  13. IMP-Producing Carbapenem-Resistant Klebsiella pneumoniae in the United States

    PubMed Central

    Limbago, Brandi M.; Rasheed, J. Kamile; Anderson, Karen F.; Zhu, Wenming; Kitchel, Brandon; Watz, Nancy; Munro, Susan; Gans, Hayley; Banaei, Niaz; Kallen, Alex J.

    2011-01-01

    The emergence and spread of carbapenem-resistant Enterobacteriaceae (CRE) producing acquired carbapenemases have created a global public health crisis. In the United States, CRE producing the Klebsiella pneumoniae carbapenemase (KPC) are increasingly common and are endemic in some regions. Metallo-β-lactamase (MBL)-producing CRE have recently been reported in the United States among patients who received medical care in countries where such organisms are common. Here, we describe three carbapenem-resistant K. pneumoniae isolates recovered from pediatric patients at a single U.S. health care facility, none of whom had a history of international travel. The isolates were resistant to carbapenems but susceptible to aztreonam, trimethoprim-sulfamethoxazole, and fluoroquinolones. The three isolates were closely related to each other by pulsed-field gel electrophoresis and contained a common plasmid. PCR and sequence analysis confirmed that these isolates produce IMP-4, an MBL carbapenemase not previously published as present among Enterobacteriaceae in the United States. PMID:21998425

  14. On the atomic state densities of plasmas produced by the ``torche à injection axiale''

    NASA Astrophysics Data System (ADS)

    Jonkers, J.; Vos, H. P. C.; van der Mullen, J. A. M.; Timmermans, E. A. H.

    1996-04-01

    The atomic state densities of helium and argon plasmas produced by the microwave driven plasma torch called the "torche à injection axiale" are presented. They are obtained by absolute line intensity measurements of the excited states and by applying the ideal gas law to the ground state. It will be shown that the atomic state distribution function (ASDF) does not obey the Saha-Boltzmann law: the ASDF cannot be described by one temperature. From the shape of the ASDF it can be concluded that the plasma is ionising. By extrapolating the measured state densities towards the ionisation limit, a minimum value of the electron density can be determined.

  15. 30 CFR 219.413 - How will the coastal political subdivisions of Gulf producing States share in the qualified OCS...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Gulf producing States share in the qualified OCS revenues? 219.413 Section 219.413 Mineral Resources... subdivisions of Gulf producing States share in the qualified OCS revenues? Of the revenues allocated to a Gulf producing State, 20 percent will be distributed to the coastal political subdivisions within that State....

  16. Excited-state spectroscopy for producing ultracold ground-state NaRb molecule

    NASA Astrophysics Data System (ADS)

    Wang, Dajun; Zhu, Bing; Guo, Mingyang; Li, Xiaoke; Lu, Bo; Wang, Fudong; Ye, Xin; Vexiau, Romain; Luc, Eliane; Bouloufa-Maafa, Nadia; Dulieu, Olivier

    2015-05-01

    We report a joint experimental and theoretical investigation on the excited states of NaRb molecule. In particular, we focus on the A1Σ+ /b3 Π admixture which is a promising intermediate state for transferring weakly-bound NaRb Feshbach molecules to the v = 0 level of the X1Σ+ state. Based on RKR potentials obtained from conventional molecular spectroscopy [1], we identified several levels which satisfy the requirements for efficient two-photon population transfer. Starting from a pure sample of NaRb Feshbach molecules, we have experimentally observed most of these levels. The detailed characterization of these levels, including their transition strengths and singlet/triplet mixing ratios, as well as searching of the v = 0 level of the X1Σ+ state with two-photon Autler-Townes spectroscopy, are well underway. This work is jointly supported by Agence Nationale de la Recherche (#ANR-13-IS04-0004-01) and Hong Kong Research Grant Council (#A-CUHK403/13) through the COPOMOL project.

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

    SciTech Connect

    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.

  18. Mn5: high-spin structures and energetics

    NASA Astrophysics Data System (ADS)

    Reveles, J. U.; Shillady, D. D.; Trindle, C.

    2016-12-01

    We characterize the geometry and electronic structure of isomers of the five atom Manganese cluster for its highest spin state, multiplicity 26. DFT calculations with various functionals and basis sets. The lowest energy form is either a D3h symmetric trigonal bipyramid or disphenoid C2v structure which can be considered a distorted trigonal bipyramid. The regular pentagon (D5h) is higher in energy but occupies a shallow relative minimum on the potential surface. The lowest energy square pyramid (C4v) is a saddle point; it spontaneously rearranges to the bisphenoid structure or the trigonal bipyramid very similar in energy. Analysis of the wave functions shows that the clusters can be considered distinct and weakly bound atoms with stabilization derived from interatomic charge-transfer interactions. Dispersion attraction seem to play a lesser role. The clusters have moderate static polarizabilities α but large first hyperpolarizabilities β, comparable with the reference system para-nitro aniline. Dynamic polarizabilities for an exciting frequency of 0.1 atomic units (wavelength 450 nm) are higher still.

  19. Observation of high-spin bands with large moments of inertia in Xe124

    SciTech Connect

    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.

    2016-09-07

    In this paper, high-spin states in 124Xe have been populated using the 80Se(48Ca, 4n) reaction at a beam energy of 207 MeV and high-multiplicity, γ-ray coincidence events were measured using the Gammasphere spectrometer. Six high-spin rotational bands with 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. Finally, 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.

  20. Observation of high-spin bands with large moments of inertia in Xe124

    SciTech Connect

    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.

    2016-09-07

    In this paper, high-spin states in 124Xe have been populated using the 80Se(48Ca, 4n) reaction at a beam energy of 207 MeV and high-multiplicity, γ-ray coincidence events were measured using the Gammasphere spectrometer. Six high-spin rotational bands with 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. Finally, 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.

  1. EPR studies on branched high-spin arylnitrenes.

    PubMed

    Chapyshev, Sergei V; Korchagin, Denis V; Budyka, Mikhail F; Gavrishova, Tatiana N; Neuhaus, Patrik; Sander, Wolfram

    2012-08-06

    The UV (λ>305 nm) photolysis of triazide 3 in 2-methyl-tetrahydrofuran glass at 7 K selectively produces triplet mononitrene 4 (g=2.003, D(T)=0.92 cm(-1), E(T)=0 cm(-1)), quintet dinitrene 6 (g=2.003, D(Q)=0.204 cm(-1), E(Q)=0.035 cm(-1)), and septet trinitrene 8 (g=2.003, D(S)=-0.0904 cm(-1), E(S) =-0.0102 cm(-1)). After 45 min of irradiation, the major products are dinitrene 6 and trinitrene 8 in a ratio of ∼1:2, respectively. These nitrenes are formed as mixtures of rotational isomers each of which has slightly different magnetic parameters D and E. The best agreement between the line-shape spectral simulations and the experimental electron paramagnetic resonance (EPR) spectrum is obtained with the line-broadening parameters Γ(E(Q))=180 MHz for dinitrene 6 and Γ(E(S))=330 MHz for trinitrene 8. According to these line-broadening parameters, the variations of the angles Θ in rotational isomers of 6 and 8 are expected to be about ±1 and ±3°, respectively. Theoretical estimations of the magnetic parameters obtained from PBE/DZ(COSMO)//UB3LYP/6-311+G(d,p) calculations overestimate the E and D values by 1 and 8 %, respectively. Despite the large distances between the nitrene units and the extended π systems, the zero field splitting (zfs) parameters D are found to be close to those in quintet dinitrenes and septet trinitrenes, where the nitrene centers are attached to the same aryl ring. The large D values of branched septet nitrenes are due to strong negative one-center spin-spin interactions in combination with weak positive two-center spin-spin interactions, as predicted by theoretical considerations. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    PubMed

    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.

  3. Band structures extending to very high spin in {sup 126}Xe

    SciTech Connect

    Roenn Hansen, C.; Sletten, G.; Hagemann, G. B.; Herskind, B.; Jensen, D. R.; Bringel, P.; Engelhardt, C.; Huebel, H.; Neusser-Neffgen, A.; Singh, A. K.; Carpenter, M. P.; Janssens, R. V. F.; Khoo, T. L.; Lauritsen, T.; Bednarczyk, P.; Byrski, T.; Curien, D.; Benzoni, G.; Bracco, A.; Camera, F.

    2007-09-15

    High-spin states in {sup 126}Xe have been populated in the {sup 82}Se({sup 48}Ca,4n){sup 126}Xe reaction in two experiments, one at the VIVITRON accelerator in Strasbourg using the Euroball detector array, and a subsequent one with ATLAS at Argonne using the Gammasphere Ge-detector array. Levels and assignments made previously for {sup 126}Xe up to I=20 have been confirmed and extended. Four regular bands extending to a spin of almost I=60, which are interpreted as two pairs of signature partners with opposite parity, are identified for the first time. The {alpha} = 0 partner of each pair is connected to the lower-lying levels, whereas the two {alpha} = 1 partners remain floating. A fractional Doppler shift analysis of transitions in the strongest populated ({pi},{alpha})=(-,0) band provides a value of 5.2{sub 0.5}{sup 0.4} b for the transition quadrupole moment, which can be related to a minimum in the potential-energy surface calculated by the ULTIMATE CRANKER cranked shell-model code at {epsilon}{approx_equal}0.35 and {gamma}{approx_equal}5 deg. The four lowest bands calculated for this minimum compare well with the two signature pairs experimentally observed over a wide spin range. A sharp upbend at ({Dirac_h}/2{pi}){omega}{approx}1170 keV is interpreted as a crossing with a band involving the j{sub 15/2} neutron orbital, for which pairing correlations are expected to be totally quenched. The four long bands extend to within {approx}5 spin units of a crossing with an yrast line defined by calculated hyperdeformed transitions and will serve as important stepping stones into the spin region beyond 60h for future experiments.

  4. Electronic, Magnetic, and Structural Characterization of the Five-Coordinate, High-Spin Iron(II) Nitrato Complex [Fe(TpivPP)(NO3)]-

    PubMed Central

    Nasri, Habib; Ellison, Mary K.; Shaevitz, Ben; Gupta, Govind P.; Robert Scheidt, W.

    2006-01-01

    The preparation and characterization of the five-coordinate iron(II) porphyrinate derivative [Fe(TpivPP)(NO3)]- (TpivPP = picket fence porphyrin) is described. Structural and magnetic susceptibility data support a high-spin state (S = 2) assignment for this species. The anionic axial nitrate ligand is oxygen-bound, through a single oxygen atom, with an Fe-O bond length of 2.069(4) Å. The planar nitrate ligand bisects an Np-Fe-Np angle. The average iron-nitrogen bond length is 2.070(16) Å. The iron atom is located 0.49 Å out of the 24-atom mean porphyrin plane toward the nitrate ligand. From solid-state Mössbauer data, the isomer shift of 0.98 mm/s at 77 K is entirely consistent with high-spin iron(II). However the quadrupole splitting of 3.59 mm/s at 77 K is unusually high for iron(II), S = 2 systems, but within the range of other five-coordinate high-spin ferrous complexes with a single anionic axial ligand. Crystal data for [K(222)][Fe(TpivPP)(NO3)].C6H5Cl: a = 17.888 (5) Å, b = 21.500 (10) Å, c = 22.514 (11) Å, and β = 100.32 (3)° , monoclinic, space group P21/n, V = 8519 Å 3, Z = 4. PMID:16813390

  5. Electronic, magnetic, and structural characterization of the five-coordinate, high-spin iron(II) nitrato complex [Fe(TpivPP)(NO3)]-.

    PubMed

    Nasri, Habib; Ellison, Mary K; Shaevitz, Ben; Gupta, Govind P; Scheidt, W Robert

    2006-07-10

    The preparation and characterization of the five-coordinate iron(II) porphyrinate derivative [Fe(TpivPP)(NO3)]- (TpivPP = picket-fence porphyrin) is described. Structural and magnetic susceptibility data support a high-spin state (S = 2) assignment for this species. The anionic axial nitrate ligand is O-bound, through a single O atom, with an Fe-O bond length of 2.069(4) A. The planar nitrate ligand bisects a N(p)-Fe-N(p) angle. The average Fe-N(p) bond length is 2.070(16) A. The Fe atom is located 0.49 A out of the 24-atom mean porphyrin plane toward the nitrate ligand. From solid-state Mössbauer data, the isomer shift of 0.98 mm/s at 77 K is entirely consistent with high-spin iron(II). However the quadrupole splitting of 3.59 mm/s at 77 K is unusually high for iron(II), S = 2 systems but within the range of other five-coordinate high-spin ferrous complexes with a single anionic axial ligand. Crystal data for [K(222)][Fe(TpivPP)(NO3)] x C6H5Cl: a = 17.888 (5) A, b = 21.500 (10) A, c = 22.514 (11) A, beta = 100.32 (3) degrees, monoclinic, space group P2(1)/n, V = 8519 A3, Z = 4.

  6. BIRTH DEFECTS IN FOUR U.S. WHEAT-PRODUCING STATES

    EPA Science Inventory

    Birth Defects in Four U.S. Wheat - Producing States
    Dina M. Schreinemachers, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

    Wheat agriculture in Mi...

  7. Socioeconomic Impacts Associated with Mineral Exploration: Louisiana Versus Other Mineral-Producing States.

    ERIC Educational Resources Information Center

    Davis, Donald W.

    1990-01-01

    Compares differences in resource exploitation and energy development in Louisiana and western mineral-producing states. Identifies socioeconomic impacts of Louisiana's offshore drilling and western coal, oil, and natural gas mining, noting the boom and bust cycles and "hyperurbanization" that attends both. Stresses the necessity of…

  8. Solid-state processes to produce hemispherical components for inertial fusion targets

    SciTech Connect

    Wise, K.D.; Robinson, M.G.; Hillegas, W.J.

    1980-01-01

    The designs proposed for next-generation targets and components for inertial fusion (IF) involve complex multilayer, multishell configurations. Solid-state process technology offers a wide assortment of fabrication techniques useful in the realization of such structures. This paper presents several such processes which are capable of producing freestanding hemishells of a variety of materials.

  9. Socioeconomic Impacts Associated with Mineral Exploration: Louisiana Versus Other Mineral-Producing States.

    ERIC Educational Resources Information Center

    Davis, Donald W.

    1990-01-01

    Compares differences in resource exploitation and energy development in Louisiana and western mineral-producing states. Identifies socioeconomic impacts of Louisiana's offshore drilling and western coal, oil, and natural gas mining, noting the boom and bust cycles and "hyperurbanization" that attends both. Stresses the necessity of…

  10. BIRTH DEFECTS IN FOUR U.S. WHEAT-PRODUCING STATES

    EPA Science Inventory

    Birth Defects in Four U.S. Wheat - Producing States
    Dina M. Schreinemachers, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711

    Wheat agriculture in Mi...

  11. 78 FR 77368 - Peanut Promotion, Research, and Information Order; Amendment to Primary Peanut-Producing States...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-23

    ... Agricultural Marketing Service 7 CFR Part 1216 Peanut Promotion, Research, and Information Order; Amendment to Primary Peanut-Producing States and Adjustment of Membership AGENCY: Agricultural Marketing Service, USDA...-coordinated program of promotion, research, and information designed to strengthen the position of peanuts in...

  12. Production of high-spin isomers in proton induced reactions at 100 500 MeV on 181 Ta

    NASA Astrophysics Data System (ADS)

    Zhuikov, B. L.; Mebel, M. V.; Kokhanyuk, V. M.; Iljinov, A. S.; Zyuzin, A. Yu.; Vincent, J. S.

    2003-11-01

    Cross sections for production of a broad variety of high-spin isomers, i.e., 177 Hfm2 ( 37/ 2- ) , 179 Hfm2 ( 25/ 2- ) , 177 Lum ( 23/ 2- ) , 180 Hfm ( 8- ) , and 178 Tam ( 7- ) from 181 Ta targets irradiated with 100, 145, 200, 350, and 500 MeV protons have been measured by off-line γ -spectroscopy. A radiochemical procedure was used to achieve high sensitivity. Isomer ratios in products ranging down to 10-3 were based on experimentally measured and theoretically calculated cross sections. It was demonstrated that the isomer ratio does not depend essentially on proton energy in the given range. Regularities in formation of isomeric states in different nuclear reactions are discussed.

  13. Contrasting behavior in octupole structures observed at high spin in {sup 220}Ra and {sup 222}Th

    SciTech Connect

    Smith, J.F.; Cocks, J.F.C.; Schulz, N.; Aieche, M.; Bentaleb, M.; Butler, P.A.; Hannachi, F.; Jones, G.D.; Jones, P.M.; Julin, R.; Juutinen, S.; Kulessa, R.; Lubkiewicz, E.; Plochocki, A.; Riess, F.; Ruchowska, E.; Savelius, A.; Sens, J.C.; Simpson, J.; Wolf, E. |||||||

    1995-08-07

    Alternating-parity states connected by strong {ital E}1 transitions, characteristic of a reflection-asymmetric rotor, have been observed to high spins in the isotones {sup 220}Ra and {sup 222}Th. This level structure is observed up to {ital J}{sup {pi}}=29{sup {minus}}(31{sup {minus}}) in {sup 220}Ra while it cannot be seen beyond {ital J}{sup +}=24{sup +}(25{sup {minus}}) in {sup 222}Th. These observations are consistent with Woods-Saxon-Bogolyubov cranking calculations which predict that the yrast band of {sup 222}Th will undergo a shape transition at {ital J}=24{h_bar}, in contrast to that of {sup 220}Ra which maintains its reflection asymmetry to higher spins.

  14. Salmonellosis outbreaks in the United States due to fresh produce: sources and potential intervention measures.

    PubMed

    Hanning, Irene B; Nutt, J D; Ricke, Steven C

    2009-01-01

    Foodborne Salmonella spp. is a leading cause of foodborne illness in the United States each year. Traditionally, most cases of salmonellosis were thought to originate from meat and poultry products. However, an increasing number of salmonellosis outbreaks are occurring as a result of contaminated produce. Several produce items specifically have been identified in outbreaks, and the ability of Salmonella to attach or internalize into vegetables and fruits may be factors that make these produce items more likely to be sources of Salmonella. In addition, environmental factors including contaminated water sources used to irrigate and wash produce crops have been implicated in a large number of outbreaks. Salmonella is carried by both domesticated and wild animals and can contaminate freshwater by direct or indirect contact. In some cases, direct contact of produce or seeds with contaminated manure or animal wastes can lead to contaminated crops. This review examines outbreaks of Salmonella due to contaminated produce, the potential sources of Salmonella, and possible control measures to prevent contamination of produce.

  15. Theory of solid effect and cross effect dynamic nuclear polarization with half-integer high-spin metal polarizing agents in rotating solids.

    PubMed

    Corzilius, Björn

    2016-10-21

    Dynamic nuclear polarization (DNP) is a powerful method to enhance sensitivity especially of solid-state magic-angle spinning (MAS) NMR by up to several orders of magnitude. The increased interest both from a practical as well as theoretical viewpoint has spawned several fields of active research such as the development of new polarizing agents with improved or unique properties and description of the underlying DNP mechanisms such as solid effect (SE) and cross effect (CE). Even though a novel class of unique polarizing agents based on high-spin metal ions such as Gd(iii) and Mn(ii) has already been utilized for MAS DNP a theoretical description of the involved DNP mechanism is still incomplete. Here, we review several aspects of DNP-relevant electron-paramagnetic resonance (EPR) properties of the general class of these half-integer high-spin metal ions with isotropic Zeeman interaction but significant zero-field splitting (ZFS). While the SE can be relatively easily described similar to that of a S = 1/2 system and is assumed to be effective only for polarizing agents featuring a narrow central EPR transitions (i.e., mS = -1/2 → +1/2) with respect to the nuclear Larmor frequency, the CE between two high-spin ions requires a more detailed theoretical investigation due to a multitude of possible transitions and matching conditions. This is especially interesting in light of recent understanding of CE being induced by MAS-driven level anti-crossings (LACs) between dipolar-coupled electron spins. We discuss the requirements of such CE-enabling LACs to occur due to anisotropy of ZFS, the expected adiabaticity, and the resulting possibilities of high-spin metal ion pairs to act as polarizing agents for DNP. This theoretical description serves as a framework for a detailed experimental study published directly following this work.

  16. Effects of Solvent on the Maximum Charge State and Charge State Distribution of Protein Ions Produced by Electrospray Ionization

    PubMed Central

    Iavarone, Anthony T.; Jurchen, John C.; Williams, Evan R.

    2005-01-01

    The effects of solvent composition on both the maximum charge states and charge state distributions of analyte ions formed by electrospray ionization were investigated using a quadrupole mass spectrometer. The charge state distributions of cytochrome c and myoglobin, formed from 47%/50%/3% water/solvent/acetic acid solutions, shift to lower charge (higher m/z) when the 50% solvent fraction is changed from water to methanol, to acetonitrile, to isopropanol. This is also the order of increasing gas-phase basicities of these solvents, although other physical properties of these solvents may also play a role. The effect is relatively small for these solvents, possibly due to their limited concentration inside the electrospray interface. In contrast, the addition of even small amounts of diethylamine (<0.4%) results in dramatic shifts to lower charge, presumably due to preferential proton transfer from the higher charge state ions to diethylamine. These results clearly show that the maximum charge states and charge state distributions of ions formed by electrospray ionization are influenced by solvents that are more volatile than water. Addition of even small amounts of two solvents that are less volatile than water, ethylene glycol and 2-methoxyethanol, also results in preferential deprotonation of higher charge state ions of small peptides, but these solvents actually produce an enhancement in the higher charge state ions for both cytochrome c and myoglobin. For instruments that have capabilities that improve with lower m/z, this effect could be taken advantage of to improve the performance of an analysis. PMID:11073261

  17. Constraints on the quantum state of pairs produced by semiclassical black holes

    NASA Astrophysics Data System (ADS)

    Brustein, Ram; Medved, A. J. M.

    2015-07-01

    The pair-production process for a black hole (BH) is discussed within the framework of a recently proposed semiclassical model of BH evaporation. Our emphasis is on how the requirements of unitary evolution and strong subadditivity act to constrain the state of the produced pairs and their entanglement with the already emitted BH radiation. We find that the state of the produced pairs is indeed strongly constrained but that the semiclassical model is consistent with all requirements. We are led to the following picture: Initially, the pairs are produced in a state of nearly maximal entanglement amongst the partners, with a parametrically small entanglement between each positive-energy partner and the outgoing radiation, similar to Hawking's model. But, as the BH evaporation progresses past the Page time, each positive-energy partner has a stronger entanglement with the outgoing radiation and, consequently, is less strongly entangled with its negative-energy partner. We present some evidence that this pattern of entanglement does not require non-local interactions, only EPR-like non-local correlations.

  18. Shiga Toxin 1-Producing Shigella sonnei Infections, California, United States, 2014-2015.

    PubMed

    Lamba, Katherine; Nelson, Jennifer A; Kimura, Akiko C; Poe, Alyssa; Collins, Joan; Kao, Annie S; Cruz, Laura; Inami, Gregory; Vaishampayan, Julie; Garza, Alvaro; Chaturvedi, Vishnu; Vugia, Duc J

    2016-04-01

    Shiga toxins (Stx) are primarily associated with Shiga toxin-producing Escherichia coli and Shigella dysenteriae serotype 1. Stx production by other shigellae is uncommon, but in 2014, Stx1-producing S. sonnei infections were detected in California. Surveillance was enhanced to test S. sonnei isolates for the presence and expression of stx genes, perform DNA subtyping, describe clinical and epidemiologic characteristics of case-patients, and investigate for sources of infection. During June 2014-April 2015, we identified 56 cases of Stx1-producing S. sonnei, in 2 clusters. All isolates encoded stx1 and produced active Stx1. Multiple pulsed-field gel electrophoresis patterns were identified. Bloody diarrhea was reported by 71% of case-patients; none had hemolytic uremic syndrome. Some initial cases were epidemiologically linked to travel to Mexico, but subsequent infections were transmitted domestically. Continued surveillance of Stx1-producing S. sonnei in California is necessary to characterize its features and plan for reduction of its spread in the United States.

  19. Shiga Toxin 1–Producing Shigella sonnei Infections, California, United States, 2014–2015

    PubMed Central

    Nelson, Jennifer A.; Kimura, Akiko C.; Poe, Alyssa; Collins, Joan; Kao, Annie S.; Cruz, Laura; Inami, Gregory; Vaishampayan, Julie; Garza, Alvaro; Chaturvedi, Vishnu; Vugia, Duc J.

    2016-01-01

    Shiga toxins (Stx) are primarily associated with Shiga toxin–producing Escherichia coli and Shigella dysenteriae serotype 1. Stx production by other shigellae is uncommon, but in 2014, Stx1-producing S. sonnei infections were detected in California. Surveillance was enhanced to test S. sonnei isolates for the presence and expression of stx genes, perform DNA subtyping, describe clinical and epidemiologic characteristics of case-patients, and investigate for sources of infection. During June 2014–April 2015, we identified 56 cases of Stx1-producing S. sonnei, in 2 clusters. All isolates encoded stx1 and produced active Stx1. Multiple pulsed-field gel electrophoresis patterns were identified. Bloody diarrhea was reported by 71% of case-patients; none had hemolytic uremic syndrome. Some initial cases were epidemiologically linked to travel to Mexico, but subsequent infections were transmitted domestically. Continued surveillance of Stx1-producing S. sonnei in California is necessary to characterize its features and plan for reduction of its spread in the United States. PMID:26982255

  20. Density functional study of the catalytic cycle of nickel-iron [NiFe] hydrogenases and the involvement of high-spin nickel(II).

    PubMed

    Pardo, Alejandro; De Lacey, Antonio L; Fernández, Víctor M; Fan, Hua-Jun; Fan, Yubo; Hall, Michael B

    2006-04-01

    In light of recent experiments suggesting high-spin (HS) Ni(II) species in the catalytic cycle of [NiFe] hydrogenase, a series of models of the Ni(II) forms Ni-SI(I,II), SI-CO and Ni-R(I,II,III) were examined in their high-spin states via density functional calculations. Because of its importance in the catalytic cycle, the Ni-C form was also included in this study. Unlike the Ni(II) forms in previous studies, in which a low-spin (LS) state was assumed and a square-planar structure found, the optimized geometries of these HS Ni(II) forms resemble those observed in the crystal structures: a distorted tetrahedral to distorted pyramidal coordination for the NiS4. This resemblance is particularly significant because the LS state is 20-30 kcal/mol less stable than the HS state for the geometry of the crystal structure. If these Ni(II) forms in the enzyme are not high spin, a large change in geometry at the active site is required during the catalytic cycle. Furthermore, only the HS state for the CO-inhibited form SI-CO has CO stretching frequencies that match the experimental results. As in the previous work, these new results show that the heterolytic cleavage reaction of dihydrogen (where H2 is cleaved with the metal acting as a hydride acceptor and a cysteine as the proton acceptor) has a lower energy barrier and is more exothermic when the active site is oxidized to Ni(III). The enzyme models described here are supported by a calibrated correlation of the calculated and measured CO stretching frequencies of the forms of the enzyme. The correlation coefficient for the final set of models of the forms of [NiFe] hydrogenase is 0.8.

  1. Direct observation of a highly spin-polarized organic spinterface at room temperature

    PubMed Central

    Djeghloul, F.; Ibrahim, F.; Cantoni, M.; Bowen, M.; Joly, L.; Boukari, S.; Ohresser, P.; Bertran, F.; Le Fèvre, P.; Thakur, P.; Scheurer, F.; Miyamachi, T.; Mattana, R.; Seneor, P.; Jaafar, A.; Rinaldi, C.; Javaid, S.; Arabski, J.; Kappler, J. -P; Wulfhekel, W.; Brookes, N. B.; Bertacco, R.; Taleb-Ibrahimi, A.; Alouani, M.; Beaurepaire, E.; Weber, W.

    2013-01-01

    Organic semiconductors constitute promising candidates toward large-scale electronic circuits that are entirely spintronics-driven. Toward this goal, tunneling magnetoresistance values above 300% at low temperature suggested the presence of highly spin-polarized device interfaces. However, such spinterfaces have not been observed directly, let alone at room temperature. Thanks to experiments and theory on the model spinterface between phthalocyanine molecules and a Co single crystal surface, we clearly evidence a highly efficient spinterface. Spin-polarised direct and inverse photoemission experiments reveal a high degree of spin polarisation at room temperature at this interface. We measured a magnetic moment on the molecule's nitrogen π orbitals, which substantiates an ab-initio theoretical description of highly spin-polarised charge conduction across the interface due to differing spinterface formation mechanisms in each spin channel. We propose, through this example, a recipe to engineer simple organic-inorganic interfaces with remarkable spintronic properties that can endure well above room temperature. PMID:23412079

  2. Synthesis and spectroscopic characterization of high-spin mononuclear iron(II) p-semiquinonate complexes.

    PubMed

    Baum, Amanda E; Park, Heaweon; Lindeman, Sergey V; Fiedler, Adam T

    2014-12-01

    Two mononuclear iron(II) p-semiquinonate (pSQ) complexes have been generated via one-electron reduction of precursor complexes containing a substituted 1,4-naphthoquinone ligand. Detailed spectroscopic and computational analysis confirmed the presence of a coordinated pSQ radical ferromagnetically coupled to the high-spin Fe(II) center. The complexes are intended to model electronic interactions between (semi)quinone and iron cofactors in biology.

  3. Proton-mediated electron configuration change in high-spin iron(II) porphyrinates.

    PubMed

    Hu, Chuanjiang; Noll, Bruce C; Schulz, Charles E; Scheidt, W Robert

    2005-11-02

    The synthesis, molecular structure, and electronic structure characterization of two five-coordinate high-spin imidazolate-ligated iron(II) porphyrinates are reported. Their electronic structure, as deduced from Mössbauer spectra obtained in strong magnetic fields, is distinctly different from that of the analogous imidazole-ligated species. The resulting electronic structure models are consistent with all observed differing features in the two classes.

  4. Low-power decoupling at high spinning frequencies in high static fields.

    PubMed

    Weingarth, Markus; Bodenhausen, Geoffrey; Tekely, Piotr

    2009-08-01

    We demonstrate that heteronuclear decoupling using a Phase-Inverted Supercycled Sequence for Attenuation of Rotary ResOnance (PISSARRO) is very efficient at high spinning frequencies (nu(rot)=60kHz) and high magnetic fields (900MHz for protons at 21T) even with moderate radio-frequency decoupling amplitudes (nu(1)(I)=15kHz), despite the wide range of isotropic chemical shifts of the protons and the increased effect of their chemical shift anisotropy.

  5. Synthesis, spectroscopy, and hydrogen/deuterium exchange in high-spin iron(II) hydride complexes.

    PubMed

    Dugan, Thomas R; Bill, Eckhard; MacLeod, K Cory; Brennessel, William W; Holland, Patrick L

    2014-03-03

    Very few hydride complexes are known in which the metals have a high-spin electronic configuration. We describe the characterization of several high-spin iron(II) hydride/deuteride isotopologues and their exchange reactions with one another and with H2/D2. Though the hydride/deuteride signal is not observable in NMR spectra, the choice of isotope has an influence on the chemical shifts of distant protons in the dimers through the paramagnetic isotope effect on chemical shift. This provides the first way to monitor the exchange of H and D in the bridging positions of these hydride complexes. The rate of exchange depends on the size of the supporting ligand, and this is consistent with the idea that H2/D2 exchange into the hydrides occurs through the dimeric complexes rather than through a transient monomer. The understanding of H/D exchange mechanisms in these high-spin iron hydride complexes may be relevant to postulated nitrogenase mechanisms.

  6. Synthesis, Spectroscopy, and Hydrogen/Deuterium Exchange in High-Spin Iron(II) Hydride Complexes

    PubMed Central

    2015-01-01

    Very few hydride complexes are known in which the metals have a high-spin electronic configuration. We describe the characterization of several high-spin iron(II) hydride/deuteride isotopologues and their exchange reactions with one another and with H2/D2. Though the hydride/deuteride signal is not observable in NMR spectra, the choice of isotope has an influence on the chemical shifts of distant protons in the dimers through the paramagnetic isotope effect on chemical shift. This provides the first way to monitor the exchange of H and D in the bridging positions of these hydride complexes. The rate of exchange depends on the size of the supporting ligand, and this is consistent with the idea that H2/D2 exchange into the hydrides occurs through the dimeric complexes rather than through a transient monomer. The understanding of H/D exchange mechanisms in these high-spin iron hydride complexes may be relevant to postulated nitrogenase mechanisms. PMID:24555749

  7. High-spin organic molecules with dominant spin-orbit contribution and unprecedentedly large magnetic anisotropy

    NASA Astrophysics Data System (ADS)

    Misochko, Eugenii Ya.; Akimov, Alexander V.; Masitov, Artem A.; Korchagin, Denis V.; Yakushchenko, Igor K.; Chapyshev, Sergei V.

    2012-08-01

    High-spin organic molecules with dominant spin-orbit contribution to magnetic anisotropy are reported. Quintet 4-azido-3,5-dibromopyridyl-2,6-dinitrene (Q-1), quintet 2-azido-3,5-dibromopyridyl-4,6-dinitrene (Q-2), and septet 3,5-dibromopyridyl-2,4,6-trinitrene (S-1) were generated in solid argon matrices by ultraviolet irradiation of 2,4,6-triazido-3,5-dibromopyridine. The zero-field splitting (ZFS) parameters, derived from electron spin resonance spectra, show unprecedentedly large magnitudes of the parameters D: |DQ1| = 0.289, |DQ2| = 0.373, and |DS1| = 0.297 cm-1. The experimental ZFS parameters were successfully reproduced by density functional theory calculations, confirming that magnetic anisotropy of high-spin organic molecules can considerably be enhanced by the "heavy atom effect." In bromine-containing high-spin nitrenes, the spin-orbit term is dominant and governs both the magnitude and the sign of magnetic anisotropy. The largest negative value of D among septet trinitrenes is predicted for 1,3,5-trinitrenobenzene bearing three heavy atoms (Br) in positions 2, 4, and 6 of the benzene ring.

  8. Long-lived states of antiprotonic lithium pLi {sup +} produced in p+ Li collisions

    SciTech Connect

    Sakimoto, Kazuhiro

    2011-09-15

    Antiproton capture by lithium atoms (p+Li{yields}pLi{sup +}+e) is investigated at collision energies from 0.01 to 10 eV by using a semiclassical (also know as quantum-classical hybrid) method, in which the radial distance between the antiproton and the Li{sup +} ion is treated as a classical variable, and the other degrees of freedom are described by quantum mechanics. Analyzing the wave packet of the emitted electrons and making use of the energy conservation rule enable us to calculate the state distribution of the produced antiprotonic lithium pLi{sup +} atoms and also to distinguish between the capture and ionization ({yields}p+Li{sup +}+e) channels at collisional energies above the ionization threshold. This method is tested for the capture of negative muons by hydrogen atoms, which was rigorously investigated in previous quantum mechanical studies. Most of the pLi{sup +} atoms produced in p+Li are found to be sufficiently stable against Auger decays and are experimentally observable as long-lived states. The present system bears close similarities to the system of p+He(2S). It is therefore expected that long-lived antiprotonic helium pHe{sup +} atoms can be efficiently produced in the p capture by metastable He(2 {sup 3}S) atoms.

  9. 30 CFR 219.414 - How will MMS determine each Gulf producing State's share of the qualified OCS revenues?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... producing State's coastline. (b) Based on these distances, we will calculate the qualified OCS revenues to... distances between the points on the State's coastline that are closest to the geographic centers of...

  10. High-spin molecules: synthesis, X-ray characterization, and magnetic behavior of two new cyano-bridged Ni(II)(9)Mo(V)(6) and Ni(II)(9)W(V)(6) clusters with a S = 12 ground state.

    PubMed

    Bonadio, Federica; Gross, Mathias; Stoeckli-Evans, Helen; Decurtins, Silvio

    2002-11-04

    The preparations, X-ray structures, and magnetic characterizations are presented for two new pentadecanuclear cluster compounds: [Ni(II)(Ni(II)(MeOH)(3))(8)(mu-CN)(30)(M(V)(CN)(3))(6)].xMeOH.yH(2)O (M(V) = Mo(V) (1) with x = 17, y = 1; M(V) = W(V) (2) with x = 15, y = 0). Both compounds crystallize in the monoclinic space group C2/c, with cell dimensions of a = 28.4957(18) A, b = 19.2583(10) A, c = 32.4279(17) A, beta = 113.155(6) degrees, and Z = 4 for 1 and a = 28.5278(16) A, b = 19.2008(18) A, c = 32.4072(17) A, beta = 113.727(6) degrees, and Z = 4 for 2. The structures of 1 and 2 consist of neutral cluster complexes comprising 15 metal ions, 9 Ni(II) and 6 M(V), all linked by mu-cyano ligands. Magnetic susceptibilities and magnetization measurements of compounds 1 and 2 in the crystalline and dissolved state indicate that these clusters have a S = 12 ground state, originating from intracluster ferromagnetic exchange interactions between the mu-cyano-bridged metal ions of the type Ni(II)-NC-M(V). Indeed, these data show clearly that the cluster molecules stay intact in solution. Ac magnetic susceptibility measurements reveal that the cluster compounds exhibit magnetic susceptibility relaxation phenomena at low temperatures since, with nonzero dc fields, chi"(M) has a nonzero value that is frequency dependent. However, there appears no out-of-phase (chi"(M)) signal in zero dc field down to 1.8 K, which excludes the expected signature for a single molecule magnet. This finding is confirmed with the small uniaxial magnetic anisotropy value for D of 0.015 cm(-1), deduced from the high-field, high-frequency EPR measurement, which distinctly reveals a positive sign in D. Obviously, the overall magnetic anisotropy of the compounds is too low, and this may be a consequence of a small single ion magnetic anisotropy combined with the highly symmetric arrangement of the metal ions in the cluster molecule.

  11. Special Technology Area Review on Lost Cost, Mass Producible, Solid-State Lasers

    DTIC Science & Technology

    2001-11-01

    far the largest number of units are shipped for optical storage applications (CD, DVD etc). O ID A Laser Revenues Unit Sales of Lasers Application...10.7 Laser Pointers 2 76 10 35.8 Materials Processing 1 38 - - Medical 1 38 - - All Other 1 38 1 3.6 Total 3790 358.0 Compound Semiconductor 6(3) April...PRODUCIBLE, SOLID-STATE LASERS November 2001 OFFICE OF THE UNDER SECRETARY OF DEFENSE ACQUISITION AND TECHNOLOGY WASHINGTON, DC 20301-3140 Report

  12. The regulatory status of xylazine for use in food-producing animals in the United States.

    PubMed

    Chamberlain, P L; Brynes, S D

    1998-08-01

    Xylazine is commonly used in veterinary medicine as a tranquillizer or adjunct to surgical anaesthesia. Although its use is approved in companion animals and certain species of deer, xylazine remains unapproved for use in food-producing animals in the United States. This paper reviews existing toxicological and residue chemistry information on xylazine in food animals, particularly cattle, and discusses the regulatory status of the drug in the US, as well as the conclusions reached by the Joint FAO/WHO Expert Committee on Food Additives in its recent evaluation of xylazine.

  13. Thermal low spin-high spin equilibrium of Fe(II) in thiospinels CuFe{sub 0.5}(Sn{sub (1-x)}Ti{sub x}){sub 1.5}S{sub 4} (0{<=}x{<=}1)

    SciTech Connect

    Womes, M.; Reibel, C.; Mari, A.; Zitoun, D.

    2011-04-15

    A series of spinel compounds with composition CuFe{sub 0.5}(Sn{sub (1-x)}Ti{sub x}){sub 1.5}S{sub 4} (0{<=}x{<=}1) is analysed by X-ray diffraction, measurements of magnetic susceptibilities and {sup 57}Fe Moessbauer spectroscopy. All samples show a temperature-dependent equilibrium between an electronic low spin 3d(t{sub 2g}){sup 6}(e{sub g}){sup 0} and a high spin 3d(t{sub 2g}){sup 4}(e{sub g}){sup 2} state of the Fe(II) ions. The spin crossover is of the continuous type and extends over several hundred degrees in all samples. The Sn/Ti ratio influences the thermal equilibrium between the two spin states. Substitution of Sn(IV) by the smaller Ti(IV) ions leads to a more compact crystal lattice, which, in contrast to many metal-organic Fe(II) complexes, does not stabilise the low spin state, but increases the residual high spin fraction for T{yields}0 K. The role played by antiferromagnetic spin coupling in the stabilisation of the high spin state is discussed. The results are compared with model calculations treating the effect of magnetic interactions on spin state equilibria. -- Graphical Abstract: Comparison of fractions of high spin Fe(II) from Moessbauer spectra (circles) with plots of {chi}{sub m}T (dots) versus T. Discrepancies between both methods indicate anti-ferromagnetic spin coupling. Display Omitted Research highlights: {yields} Many Fe(II) complexes show thermally induced high spin-low spin crossover. {yields} Spin crossover in spinel compounds is extremely scarce. {yields} Usually, lattice contraction favours the low spin state in Fe(II) complexes. {yields} In these spinels, lattice contraction favours the high spin state. {yields} The stabilisation of the high spin state is explained by spin-spin interactions.

  14. Quantitative approach to track lipase producing Pseudomonas sp. S1 in nonsterilized solid state fermentation.

    PubMed

    Sahoo, R K; Subudhi, E; Kumar, M

    2014-06-01

    Proliferation of the inoculated Pseudomonas sp. S1 is quantitatively evaluated using ERIC-PCR during the production of lipase in nonsterile solid state fermentation an approach to reduce the cost of enzyme production. Under nonsterile solid state fermentation with olive oil cake, Pseudomonas sp. S1 produced 57·9 IU g(-1) of lipase. DNA fingerprints of unknown bacterial isolates obtained on Bushnell Haas agar (BHA) + tributyrin exactly matched with that of Pseudomonas sp. S1. Using PCR-based enumeration, population of Pseudomonas sp. S1 was proliferated from 7·6 × 10(4) CFU g(-1) after 24 h to 4·6 × 10(8) CFU g(-1) after 96 h, which tallied with the maximum lipase activity as compared to control. Under submerged fermentation (SmF), Pseudomonas sp. S1 produced maximum lipase (49 IU ml(-1) ) using olive oil as substrate, while lipase production was 9·754 IU ml(-1) when Pseudomonas sp. S1 was grown on tributyrin. Optimum pH and temperature of the crude lipase was 7·0 and 50°C. Crude enzyme activity was 71·2% stable at 50°C for 360 min. Pseudomonas sp. S1 lipase was also stable in methanol showing 91·6% activity in the presence of 15% methanol, whereas 75·5 and 51·1% of activity were retained in the presence of 20 and 30% methanol, respectively. Thus, lipase produced by Pseudomonas sp. S1 is suitable for the production of biodiesel as well as treatment of oily waste water. This study presents the first report on the production of thermophilic organic solvent tolerant lipase using agro-industry waste in nonsterile solid state fermentation. Positive correlation between survival of Pseudomonas sp. S1 and lipase production under nonsterile solid state fermentation was established, which may emphasize the need to combine molecular tools and solid state fermentation in future studies. Our study brings new insights into the lipase production in cost-effective manner, which is an industrially relevant approach. © 2014 The Society for Applied Microbiology.

  15. Solid-State NMR Investigation of Bio-chars Produced from Biomass Components and Whole Biomasses

    DOE PAGES

    Ben, Haoxi; Hao, Naijia; Liu, Qian; ...

    2017-08-24

    Bio-char is a by-product from thermochemical treatment of biomass and has been identified as an energy condensed product with a comparable heating value as commercial coal. However, the combustion of such solid product as an energy resource is only a preliminary application. It is highly possible to convert bio-char, which always has a condensed aromatic and porous structure to various high-value products. The investigations of the structures and formation pathways for the bio-char are very important to any future applications. In this study, six different biomass components, including cellulose, lignin, and tannin, and three whole biomasses—pine wood, pine residue, andmore » pine bark—have been used to produce bio-char at 400, 500, and 600 °C. Solid-state NMR and FT-IR have been employed in this study to characterize the structures for the bio-chars. The results indicated that the bio-chars produced from lignin contained some methoxyl groups, and the bio-chars produced from tannin contained significantly higher amount of phenolic hydroxyl groups. Compared to the bio-chars produced from pine wood and residue, the bio-chars produced from pine bark contained more aromatic C–O bonds, and aliphatic C–O and C–C bonds, which may be due to the significantly higher amount of lignin and tannin in the pine bark. Furthermore, the elevated amounts of aromatic C–O and aliphatic C–O and C–C bonds in the bio-chars from pine bark appeared to be completely decomposed at 600 °C.« less

  16. Oil and gas technology transfer activities and potential in eight major producing states. Volume 1

    SciTech Connect

    Not Available

    1993-07-01

    In 1990, the Interstate Oil and Gas Compact Commission (the Compact) performed a study that identified the structure and deficiencies of the system by which oil and gas producers receive information about the potential of new technologies and communicate their problems and technology needs back to the research community. The conclusions of that work were that major integrated companies have significantly more and better sources of technology information than independent producers. The majors also have significantly better mechanisms for communicating problems to the research and development (R&D) community. As a consequence, the Compact recommended analyzing potential mechanisms to improve technology transfer channels for independents and to accelerate independents acceptance and use of existing and emerging technologies. Building on this work, the Compact, with a grant from the US Department Energy, has reviewed specific technology transfer organizations in each of eight major oil producing states to identify specific R&D and technology transfer organizations, characterize their existing activities, and identify potential future activities that could be performed to enhance technology transfer to oil and gas producers. The profiles were developed based on information received from organizations,follow-up interviews, site visit and conversations, and participation in their sponsored technology transfer activities. The results of this effort are reported in this volume. In addition, the Compact has also developed a framework for the development of evaluation methodologies to determine the effectiveness of technology transfer programs in performing their intended functions and in achieving desired impacts impacts in the producing community. The results of that work are provided in a separate volume.

  17. Polymodal activation of the TREK-2 K2P channel produces structurally distinct open states

    PubMed Central

    McClenaghan, Conor; Schewe, Marcus; Aryal, Prafulla; Carpenter, Elisabeth P.; Baukrowitz, Thomas

    2016-01-01

    The TREK subfamily of two-pore domain (K2P) K+ channels exhibit polymodal gating by a wide range of physical and chemical stimuli. Crystal structures now exist for these channels in two main states referred to as the “up” and “down” conformations. However, recent studies have resulted in contradictory and mutually exclusive conclusions about the functional (i.e., conductive) status of these two conformations. To address this problem, we have used the state-dependent TREK-2 inhibitor norfluoxetine that can only bind to the down state, thereby allowing us to distinguish between these two conformations when activated by different stimuli. Our results reconcile these previously contradictory gating models by demonstrating that activation by pressure, temperature, voltage, and pH produce more than one structurally distinct open state and reveal that channel activation does not simply involve switching between the up and down conformations. These results also highlight the diversity of structural mechanisms that K2P channels use to integrate polymodal gating signals. PMID:27241700

  18. 30 CFR 219.415 - How will bonus and royalty credits affect revenues allocated to Gulf producing States?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How will bonus and royalty credits affect revenues allocated to Gulf producing States? 219.415 Section 219.415 Mineral Resources MINERALS MANAGEMENT... allocated to Gulf producing States? If bonus and royalty credits issued under Section 104(c) of the Gulf...

  19. Mixed-Valent Dicobalt and Iron-Cobalt Complexes with High-Spin Configurations and Short Metal-Metal Bonds

    SciTech Connect

    Zall, Christopher M.; Clouston, Laura J.; Young, Jr., Victor G.; Ding, Keying; Kim, Hyun Jung; Zherebetskyy, Danylo; Chen, Yu-Sheng; Bill, Eckhard; Gagliardi, Laura; Lu, Connie C.

    2013-09-23

    Cobalt–cobalt and iron–cobalt bonds are investigated in coordination complexes with formally mixed-valent [M2]3+ cores. The trigonal dicobalt tris(diphenylformamidinate) compound, Co2(DPhF)3, which was previously reported by Cotton, Murillo, and co-workers (Inorg. Chim. Acta 1996, 249, 9), is shown to have an energetically isolated, high-spin sextet ground-state by magnetic susceptibility and electron paramagnetic resonance (EPR) spectroscopy. A new tris(amidinato)amine ligand platform is introduced. By tethering three amidinate donors to an apical amine, this platform offers two distinct metal-binding sites. Using the phenyl-substituted variant (abbreviated as LPh), the isolation of a dicobalt homobimetallic and an iron–cobalt heterobimetallic are demonstrated. The new [Co2]3+ and [FeCo]3+ cores have high-spin sextet and septet ground states, respectively. Their solid-state structures reveal short metal–metal bond distances of 2.29 Å for Co–Co and 2.18 Å for Fe–Co; the latter is the shortest distance for an iron–cobalt bond to date. To assign the positions of iron and cobalt atoms as well as to determine if Fe/Co mixing is occurring, X-ray anomalous scattering experiments were performed, spanning the Fe and Co absorption energies. These studies show only a minor amount of metal-site mixing in this complex, and that FeCoLPh is more precisely described as (Fe0.94(1)Co0.06(1))(Co0.95(1)Fe0.05(1))LPh. The iron–cobalt heterobimetallic has been further characterized by Mössbauer spectroscopy. Its isomer shift of 0.65 mm/s and quadrupole splitting of 0.64 mm/s are comparable to the related diiron complex, Fe2(DPhF)3. On the basis of spectroscopic data and theoretical calculations, it is proposed that the formal [M2]3+ cores are fully delocalized.

  20. Fluorescence technique for on-line monitoring of state of hydrogen-producing microorganisms

    DOEpatents

    Seibert, Michael; Makarova, Valeriya; Tsygankov, Anatoly A.; Rubin, Andrew B.

    2007-06-12

    In situ fluorescence method to monitor state of sulfur-deprived algal culture's ability to produce H.sub.2 under sulfur depletion, comprising: a) providing sulfur-deprived algal culture; b) illuminating culture; c) measuring onset of H.sub.2 percentage in produced gas phase at multiple times to ascertain point immediately after anerobiosis to obtain H.sub.2 data as function of time; and d) determining any abrupt change in three in situ fluorescence parameters; i) increase in F.sub.t (steady-state level of chlorophyll fluorescence in light adapted cells); ii) decrease in F.sub.m', (maximal saturating light induced fluorescence level in light adapted cells); and iii) decrease in .DELTA.F/F.sub.m'=(F.sub.m'-F.sub.t)/F.sub.m' (calculated photochemical activity of photosystem II (PSII) signaling full reduction of plastoquinone pool between PSII and PSI, which indicates start of anaerobic conditions that induces synthesis of hydrogenase enzyme for subsequent H.sub.2 production that signal oxidation of plastoquinone pool asmain factor to regulate H.sub.2 under sulfur depletion.

  1. [Characterization of labor conditions and state of health among ammonia nitrate producing workers].

    PubMed

    Tsimakuridze, M P

    2005-01-01

    A complicated inquiry of worker's working conditions at enterprises that are producing ammonia nitrate has been conducted. It was determined that during the production process hazardous chemical compounds were used. It was found that labor conditions of studied industry are in unfavorable state. The most important problem is air pollution with toxic gazes. The atmosphere at the enterprises producing ammonia nitrate is significantly polluted by ammonia, nitrous acid and nitrogenous gazes. Concentration of toxic substances depends on the character of the technological process. High air temperature has bad effects on health during warm periods of the year. Noise factor and general industrial vibration exceed acceptable level in the majority of working area. The figures for sickness rate of workers with temporary loss of ability for work during three years have been analyzed. It has been stated that general rate of morbidity is not high, but this index in basic group 3.6-5.1 times exceeds the analogous figure in the control group. In the structure of morbidity diseases of respiratory, musculoskeletal, cardiovascular, neural, kidney and digestive systems are frequent and they amount to 76% of the whole cases. The clinical examination of the workers with basic professions of the production of ammonia nitrate shows the frequent cases of chronic bronchitis and radiculoneuropathy. The results of function study show the damage of airways and the myocardiodystrophy. This confirms the major role of occupational- professional factors in the etiology of these pathological conditions.

  2. High-spin-low-spin transition in magnesiowüstite (Mg0.75,Fe0.25)O at high pressures under hydrostatic conditions

    NASA Astrophysics Data System (ADS)

    Lyubutin, I. S.; Gavriliuk, A. G.; Frolov, K. V.; Lin, J. F.; Troyan, I. A.

    2010-01-01

    The spin states of Fe2+ ions in (Mg0.75,Fe0.25)O magnesiowüstite crystals at hydrostatic pressures up to 90 GPa created in a diamond-anvil cell with helium as a pressure-transmitting medium have been investi-gated by transmission and synchrotron Mössbauer spectroscopy at room temperature. An electron transition from the high-spin (HS) state to the low-spin (LS) state (HS-LS crossover) has been observed in the pressure range of 55-70 GPa. The true HS-LS transition occurs in a narrow pressure range and the extension of the electron transition to ˜15 GPa is attributed to the effect of the nearest environment and to thermal fluctuations between the high-spin and low-spin states at finite temperatures. It has been found that the lowest pressure at which the electron HS-LS transition can occur in the Mg1 - x Fe x system is 50-55 GPa.

  3. Development of a Solid-State Fermentation System for Producing Bioethanol from Food Waste

    NASA Astrophysics Data System (ADS)

    Honda, Hiroaki; Ohnishi, Akihiro; Fujimoto, Naoshi; Suzuki, Masaharu

    Liquid fermentation is the a conventional method of producing bioethanol. However, this method results in the formation of high concentrations waste after distillation and futher treatment requires more energy and is costly(large amounts of costly energy).Saccharification of dried raw garbage was tested for 12 types of Koji starters under the following optimum culture conditions: temperature of 30°C and initial moisture content of 50%.Among all the types, Aspergillus oryzae KBN650 had the highest saccharifying power. The ethanol-producing ability of the raw garbage was investigated for 72 strains of yeast, of which Saccharomyces cerevisiae A30 had the highest ethanol production(yield)under the following optimum conditions: 1 :1 ratio of dried garbage and saccharified garbage by weight, and initial moisture content of 60%. Thus, the solid-state fermentation system consisted of the following 4 processes: moisture control, saccharification, ethanol production and distillation. This system produced 0.6kg of ethanol from 9.6kg of garbage. Moreover the ethanol yield from all sugars was calculated to be 0.37.

  4. Exploring flavour-producing core microbiota in multispecies solid-state fermentation of traditional Chinese vinegar

    PubMed Central

    Wang, Zong-Min; Lu, Zhen-Ming; Shi, Jin-Song; Xu, Zheng-Hong

    2016-01-01

    Multispecies solid-state fermentation (MSSF), a natural fermentation process driven by reproducible microbiota, is an important technique to produce traditional fermented foods. Flavours, skeleton of fermented foods, was mostly produced by microbiota in food ecosystem. However, the association between microbiota and flavours and flavour-producing core microbiota are still poorly understood. Here, acetic acid fermentation (AAF) of Zhenjiang aromatic vinegar was taken as a typical case of MSSF. The structural and functional dynamics of microbiota during AAF process was determined by metagenomics and favour analyses. The dominant bacteria and fungi were identified as Acetobacter, Lactobacillus, Aspergillus, and Alternaria, respectively. Total 88 flavours including 2 sugars, 9 organic acids, 18 amino acids, and 59 volatile flavours were detected during AAF process. O2PLS-based correlation analysis between microbiota succession and flavours dynamics showed bacteria made more contribution to flavour formation than fungi. Seven genera including Acetobacter, Lactobacillus, Enhydrobacter, Lactococcus, Gluconacetobacer, Bacillus and Staphylococcus were determined as functional core microbiota for production of flavours in Zhenjiang aromatic vinegar, based on their dominance and functionality in microbial community. This study provides a perspective for bridging the gap between the phenotype and genotype of ecological system, and advances our understanding of MSSF mechanisms in Zhenjiang aromatic vinegar. PMID:27241188

  5. Enzymatic hydrolysis and characterization of waste lignocellulosic biomass produced after dye bioremediation under solid state fermentation.

    PubMed

    Waghmare, Pankajkumar R; Kadam, Avinash A; Saratale, Ganesh D; Govindwar, Sanjay P

    2014-09-01

    Sugarcane bagasse (SCB) adsorbes 60% Reactive Blue172 (RB172). Providensia staurti EbtSPG able to decolorize SCB adsorbed RB172 up to 99% under solid state fermentation (SSF). The enzymatic saccharification efficiency of waste biomass after bioremediation of RB172 process (ddSCB) has been evaluated. The cellulolyitc crude enzyme produced by Phanerochaete chrysosporium used for enzymatic hydrolysis of native SCB and ddSCB which produces 0.08 and 0.3 g/L of reducing sugars respectively after 48 h of incubation. The production of hexose and pentose sugars during hydrolysis was confirmed by HPTLC. The effect of enzymatic hydrolysis on SCB and ddSCB has been evaluated by FTIR, XRD and SEM analysis. Thus, during dye biodegradation under SSF causes biological pretreatment of SCB which significantly enhanced its enzymatic saccharification. Adsorption of dye on SCB, its bioremediation under SSF produces wastes biomass and which further utilized for enzymatic saccharification for biofuel production. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Ultrasound-assisted extraction and characterization of hydrolytic and oxidative enzymes produced by solid state fermentation.

    PubMed

    Szabo, Orsolya Erzsebet; Csiszar, Emilia; Toth, Karolina; Szakacs, George; Koczka, Bela

    2015-01-01

    Ligninolytic and hydrolytic enzymes were produced with six selected fungi on flax substrate by solid state fermentation (SSF). The extracellular enzyme production of the organisms in two SSF media was evaluated by measuring the soluble protein concentration and the filter paper, endoxylanase, 1,4-β-d-glucosidase, 1,4-β-d-endoglucanase, polygalacturonase, lignin peroxidase, manganese peroxidase and laccase activities of the clear culture solutions produced by conventional extraction from the SSF materials. The SSF material of the best enzyme producer (Trichoderma virens TUB F-498) was further investigated to enhance the enzyme recovery by low frequency ultrasound treatment. Performance of both the original and ultrasound macerated crude enzyme mixtures was evaluated in degradation of the colored lignin-containing and waxy materials of raw linen fabric. Results proved that sonication (at 40%, 60% and 80% amplitudes, for 60min) did not result in reduction in the filter paper, lignin peroxidase and laccase activities of the crude enzyme solution, but has a significant positive effect on the efficiency of enzyme extraction from the SSF material. Depending on the parameters of sonication, the enzyme activities in the extracts obtained can be increased up to 129-413% of the original activities measured in the control extracts recovered by a common magnetic stirrer. Sonication also has an effect on both the enzymatic removal of the lignin-containing color materials and hydrophobic surface layer from the raw linen. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Aroma characteristics of Moutai-flavour liquor produced with Bacillus licheniformis by solid-state fermentation.

    PubMed

    Zhang, R; Wu, Q; Xu, Y

    2013-07-01

    The potential of Bacillus licheniformis as a starter culture for aroma concentration improvement in the fermentation of Chinese Moutai-flavour liquor was elucidated. The volatile compounds produced by B. licheniformis were identified by GC-MS, in which C4 compounds, pyrazines, volatile acids, aromatic and phenolic compounds were the main ingredients. The strains B. licheniformis (MT-6 and MT-15) produced more volatile compound concentrations, mainly C4 compounds, than the type strain of B. licheniformis (ATCC 14580) at the fermentation temperature of 55°C. Meanwhile, more volatile compound concentrations were produced by B. licheniformis in solid-state fermentation than in submerged state fermentation. Thus, the strains MT-6 and MT-15 were used as the Bacillus starter culture for investigating Moutai-flavour liquor production. The distilled liquor inoculated with Bacillus starter culture was significantly different from the liquor without inoculum. This was particularly evident in the fore-run part of the distilled sample which was inoculated with Bacillus starter culture, where volatile compounds greatly increased compared to the control. Furthermore, the distilled liquor with Bacillus starter culture showed improved results in sensory appraisals. These results indicated that B. licheniformis was one of the main species influencing the aroma characteristics of Moutai-flavour liquor. This is the first report of an investigation into the effect of Bacillus starter cultures on the flavour features of Moutai-flavour liquor, which verified that Bacillus licheniformis can enhance aroma concentration in Moutai-flavour liquor. Bacillus starter culture brought C4 compounds, pyrazines, volatile acids, aromatic and phenolic compounds to the liquor, which gave a better result in sensory appraisals. © 2013 The Society for Applied Microbiology.

  8. Evolution of the phenazine biosynthesis pathway and diversity of phenazine-producing Pseudomonas spp. in dryland wheat-producing areas of Washington state

    USDA-ARS?s Scientific Manuscript database

    Phenazines are versatile secondary metabolites of bacterial origin that function as signaling compounds and contribute to the ecological fitness and pathogenicity of the producing strains. A 2007-2008 survey of commercial dryland fields in central Washington State (annual precipitation <15 in) revea...

  9. Liquid State Forging: Novel Potentiality to Produce High Performance Components, Process, Plant and Tooling

    NASA Astrophysics Data System (ADS)

    Rosso, M.; Zago, A.; Claus, P.; Motoiu, P.

    2007-04-01

    The paper deals about a new patented process able to the production of high resistance and high toughness parts, taking into consideration also the tooling need. The molten alloy is introduced into the die cavity at low pressure, then the alloy is forged. The forging action takes place during the alloy solidification process, favouring the reduction of the duration of the process and the production of parts characterised by very high mechanical and ductility properties. The very high mechanical characteristics of the produced parts are obtained thank to their very low porosity content, as well as to their unique microstructure features. Moreover, the process allow the optimisation of the yield of the alloy, in fact the feeding system and the risers are practically absent, this means minimum production of scraps to be recycled. After a short description of the main features of the equipment and of the process, the work take into consideration the aluminium based produced parts, in their as cast state and after T6 heat treatment, comparing their characteristics with those obtainable by the most traditional low pressure and gravity casting processes. In particular, samples for the evaluation of the mechanical properties have been machined from the produced parts to obtain their tensile strength, together with their ductility characteristics. The maximum attained hardness values have also been evaluated. Tensile strength higher than 440 MPa, with elongation up to 18% with hardness higher than 125 HB are easily attainable on Al alloys type A356. Light microscopy observations performed on the transverse section of polished samples and the analysis of the fracture surfaces after mechanical tests allowed to focus the attention on the microstructure details and to highlight the ductile aspects of the fracture to confirm the high quality and high performance of the produced parts.

  10. High-spin μs isomeric states in 96Ag

    NASA Astrophysics Data System (ADS)

    Becerril, A. D.; Lorusso, G.; Amthor, A. M.; Baumann, T.; Bazin, D.; Berryman, J. S.; Brown, B. A.; Crawford, H. L.; Estrade, A.; Gade, A.; Ginter, T.; Guess, C. J.; Hausmann, M.; Hitt, G. W.; Mantica, P. F.; Matos, M.; Meharchand, R.; Minamisono, K.; Montes, F.; Perdikakis, G.; Pereira, J.; Portillo, M.; Schatz, H.; Smith, K.; Stoker, J.; Stolz, A.; Zegers, R. G. T.

    2011-10-01

    The isomeric and β decays of the N=Z+2 nucleus 96Ag were investigated at the National Superconducting Cyclotron Laboratory. A cascade of γ-ray transitions originating from the deexcitation of a microsecond isomer was observed for the first time and was found in coincidence with two previously known transitions with energies of 470 and 667 keV. The isomeric half-life was determined as 1.45(7) μs, more precise than previously reported. The existence of a second, longer-lived microsecond isomer, associated with a 743-keV γ transition, is also proposed here. Shell model results within the (p3/2p1/2f5/2g9/2) model space, using the jj44b interaction, reproduced level energies and isomeric decay half-lives reasonably well.

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

    PubMed

    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.

  12. Quadrupole moments of high spin isomers in sup 213 Fr, sup 212 Fr, and sup 211 Fr

    SciTech Connect

    Hardeman, F.; Neyens, G.; Scheveneels, G.; Nouwen, R.; S'heeren, G.; Van Den Bergh, M.; Coussement, R. ); Byrne, A.P.; Muesseler, R.; Huebel, H.; Baldsiefen, G. )

    1991-02-01

    The level mixing spectroscopy method has been applied to measure the static quadrupole moments of six isomeric states in {sup 213}Fr, {sup 212}Fr, and {sup 211}Fr ({ital Z}=87). For isomers with the proton configuration {pi}{ital h}{sub 9/2}{sup 4}{ital i}{sub 13/2} a large increase of the quadrupole moment was observed with the removal of neutrons from the closed {ital N}=126 core: {ital Q}(29/2{sup +},{sup 213}Fr)={minus}70(7) {ital e} fm{sup 2}, {ital Q}(15{sup {minus}},{sup 212}Fr)={minus}80(12) {ital e} fm{sup 2}, and {ital Q}(29/2{sup +},{sup 211}Fr)={minus}107(18) {ital e} fm{sup 2}. Quadrupole moments for very high spin states were also measured: {ital Q}(65/2{sup {minus}},{sup 213}Fr)={minus}219(53) {ital e} fm{sup 2}, {ital Q}(27{sup {minus}},{sup 212}Fr)={minus}152(31) {ital e} fm{sup 2}, and {ital Q}(45/2{sup {minus}},{sup 211}Fr) ={minus}198(56) {ital e} fm{sup 2}. The observed values are in good agreement with shell-model calculations, but are lower than that predicted using the deformed-independent particle model. The implantation behavior of Fr in a Tl host is also discussed.

  13. Measurement of Br photofragment orientation and alignment from HBr photodissociation: Production of highly spin-polarized hydrogen atoms

    SciTech Connect

    Rakitzis, T. Peter; Samartzis, P.C.; Toomes, R.L.; Kitsopoulos, Theofanis N.

    2004-10-15

    The orientation and alignment of the {sup 2}P{sub 3/2} and {sup 2}P{sub 1/2} Br photofragments from the photodissociation of HBr is measured at 193 nm in terms of a{sub q}{sup (k)}(p) parameters, using slice imaging. The A {sup 1}{pi} state is excited almost exclusively, and the measured a{sub q}{sup (k)}(p) parameters and the spin-orbit branching ratio show that the dissociation proceeds predominantly via nonadiabatic transitions to the a {sup 3}{pi} and 1 {sup 3}{sigma}{sup +} states. Conservation of angular momentum shows that the electrons of the nascent H atom cofragments (recoiling parallel to the photolysis polarization) are highly spin polarized: about 100% for the Br({sup 2}P{sub 1/2}) channel, and 86% for the Br({sup 2}P{sub 3/2}) channel. A similar analysis is demonstrated for the photodissociation of HCl.

  14. High-spin level scheme and decay of the 67-{mu}s isomer in {sup 142}Pm

    SciTech Connect

    Liu, M.L.; Zhang, Y.H.; Zhou, X.H.; Guo, Y.X.; Lei, X.G.; Liu, Z.; He, J.J.; Wen, S.X.; Wu, X.G.; Yuan, G.J.

    2004-07-01

    An in-beam {gamma}-ray spectroscopy experiment for {sup 142}Pm has been performed via the {sup 128}Te({sup 19}F,5n) reaction at beam energies of 75 MeV through 95 MeV. Excitation functions and {gamma}-{gamma} coincidences have been measured. Detailed analysis of {gamma}-{gamma} coincidence relationships leads to a revised high-spin level scheme for {sup 142}Pm. The {pi}h{sub 11/2}x{nu}h{sub 11/2}{sup -1} multiplet in this nucleus has been identified and the discussion is based on a systematic of corresponding states in neighboring odd-odd nuclei. The previously known 67-{mu}s isomer and associated decay {gamma} rays have been placed into the new level scheme. This long-lived isomer is proposed to be a four-hole state with predominantly the ({pi}g{sub 7/2}{sup -1}d{sub 5/2}{sup -2}x{nu}h{sub 11/2}{sup -1}){sub 13{sup -}} configuration.

  15. A density functional theory study of the zero-field splitting in high-spin nitrenes.

    PubMed

    Misochko, Eugenii Ya; Korchagin, Denis V; Bozhenko, Konstantin V; Chapyshev, Sergei V; Aldoshin, Sergei M

    2010-08-14

    This work presents a detailed evaluation of the performance of density functional theory (DFT) for the prediction of zero-field splittings (ZFSs) in high-spin nitrenes. A number of well experimentally characterized triplet mononitrenes, quartet nitrenoradicals, quintet dinitrenes, and septet trinitrenes have been considered. Several DFT-based approaches for the prediction of ZFSs have been compared. It is shown that the unrestricted Kohn-Sham and the Pederson-Khanna approaches are the most successful for the estimation of the direct spin-spin (SS) interaction and the spin-orbit coupling (SOC) parts, respectively, to the final ZFS parameters. The most accurate theoretical predictions (within 10%) are achieved by using the PBE density functional in combination with the DZ, EPR-II, and TZV basis sets. For high-spin nitrenes constituted from light atoms, the contribution of the SOC part to ZFS parameters is quite small (7%-12%). By contrast, for chlorine-substituted septet trinitrenes, the contribution of the SOC part is small only to D value but, in the case of E value, it is as large as the SS part and has opposite sign. Due to this partial cancellation of two different contributions, SS and SOC, the resulting values of E in heavy molecules are almost two times smaller than those predicted by analysis of the widely used semiempirical one-center spin-spin interaction model. The decomposition of D(SS) into n-center (n=1-4) interactions shows that the major contribution to D(SS) results from the one-center spin-spin interactions. This fact indicates that the semiempirical SS interaction model accurately predicts the ZFS parameters for all types of high-spin nitrenes with total spin S=2 and 3, if their molecules are constructed from the first-row atoms.

  16. A density functional theory study of the zero-field splitting in high-spin nitrenes

    NASA Astrophysics Data System (ADS)

    Misochko, Eugenii Ya.; Korchagin, Denis V.; Bozhenko, Konstantin V.; Chapyshev, Sergei V.; Aldoshin, Sergei M.

    2010-08-01

    This work presents a detailed evaluation of the performance of density functional theory (DFT) for the prediction of zero-field splittings (ZFSs) in high-spin nitrenes. A number of well experimentally characterized triplet mononitrenes, quartet nitrenoradicals, quintet dinitrenes, and septet trinitrenes have been considered. Several DFT-based approaches for the prediction of ZFSs have been compared. It is shown that the unrestricted Kohn-Sham and the Pederson-Khanna approaches are the most successful for the estimation of the direct spin-spin (SS) interaction and the spin-orbit coupling (SOC) parts, respectively, to the final ZFS parameters. The most accurate theoretical predictions (within 10%) are achieved by using the PBE density functional in combination with the DZ, EPR-II, and TZV basis sets. For high-spin nitrenes constituted from light atoms, the contribution of the SOC part to ZFS parameters is quite small (7%-12%). By contrast, for chlorine-substituted septet trinitrenes, the contribution of the SOC part is small only to D value but, in the case of E value, it is as large as the SS part and has opposite sign. Due to this partial cancellation of two different contributions, SS and SOC, the resulting values of E in heavy molecules are almost two times smaller than those predicted by analysis of the widely used semiempirical one-center spin-spin interaction model. The decomposition of DSS into n-center (n =1-4) interactions shows that the major contribution to DSS results from the one-center spin-spin interactions. This fact indicates that the semiempirical SS interaction model accurately predicts the ZFS parameters for all types of high-spin nitrenes with total spin S =2 and 3, if their molecules are constructed from the first-row atoms.

  17. Method of producing ceramic distribution members for solid state electrolyte cells

    NASA Technical Reports Server (NTRS)

    Clark, Douglas J. (Inventor); Galica, Leo M. (Inventor); Losey, Robert W. (Inventor); Suitor, Jerry W. (Inventor)

    1995-01-01

    A solid state electrolyte cells apparatus and method of producing is disclosed. The apparatus can be used for separating oxygen from an oxygen-containing feedstock or as a fuel cell for reacting fluids. Cells can be stacked so that fluids can be introduced and removed from the apparatus through ceramic distribution members having ports designed for distributing the fluids in parallel flow to and from each cell. The distribution members can also serve as electrodes to membranes or as membrane members between electrodes, The distribution member design does not contain any horizontal internal ports which allows the member to be thin. A method of tape casting in combination with an embossing method allows intricate radial ribs and bosses to be formed on each distribution member. The bosses serve as seals for the ports and allow the distribution members to be made without any horizontal internal ports.

  18. Ceramic distribution members for solid state electrolyte cells and method of producing

    NASA Technical Reports Server (NTRS)

    Clark, Douglas J. (Inventor); Galica, Leo M. (Inventor); Losey, Robert W. (Inventor); Suitor, Jerry W. (Inventor)

    1993-01-01

    A solid state electrolyte cells apparatus and method of producing is disclosed. The apparatus can be used for separating oxygen from an oxygen-containing feedstock or as a fuel cell for reacting fluids. Cells can be stacked so that fluids can be introduced and removed from the apparatus through ceramic distribution members having ports designed for distributing the fluids in parallel flow to and from each cell. The distribution members can also serve as electrodes to membranes or as membrane members between electrodes. The distribution member design does not contain any horizontal internal ports which allows the member to be thin. A method of tape casting in combination with an embossing method allows intricate radial ribs and bosses to be formed on each distribution member. The bosses serve as seals for the ports and allow the distribution members to be made without any horizontal internal ports.

  19. Do cigarette producers price-discriminate by state? An empirical analysis of local cigarette pricing and taxation.

    PubMed

    Keeler, T E; Hu, T W; Barnett, P G; Manning, W G; Sung, H Y

    1996-08-01

    This study analyzes the interactive effects of oligopoly pricing, state taxation, and anti-smoking regulations on retail cigarette prices by state, using panel data for the 50 US states between 1960 and 1990. The results indicate that cigarette producers do price-discriminate by state, though the effect is not large relative to the final retail price. There are two further results: (1) state taxes are more than passed on - a 1-cent state tax increase results in a price increase of 1.11 cents, and (2) sellers offset state and local anti-smoking laws with lower prices, thereby blunting effects of the regulations.

  20. On the episodic nature of derecho-producing convective systems in the United States

    NASA Astrophysics Data System (ADS)

    Ashley, Walker S.; Mote, Thomas L.; Bentley, Mace L.

    2005-11-01

    Convectively generated windstorms occur over broad temporal and spatial scales; however, one of the larger-scale and most intense of these windstorms has been given the name derecho. This study illustrates the tendency for derecho-producing mesoscale convective systems to group together across the United States - forming a derecho series. The derecho series is recognized as any succession of derechos that develop within a similar synoptic environment with no more than 72 h separating individual events. A derecho dataset for the period 1994-2003 was assembled to investigate the groupings of these extremely damaging convective wind events. Results indicate that over 62% of the derechos in the dataset were members of a derecho series. On average, nearly six series affected the United States annually. Most derecho series consisted of two or three events; though, 14 series during the period of record contained four or more events. Two separate series involved nine derechos within a period of nine days. Analyses reveal that derecho series largely frequent regions of the Midwest, Ohio Valley, and the south-central Great Plains during May, June, and July. Results suggest that once a derecho occurred during May, June, or July, there was a 58% chance that this event was the first of a series of two or more, and about a 46% chance that this was the first of a derecho series consisting of three or more events. The derecho series climatology reveals that forecasters in regions frequented by derechos should be prepared for the probable regeneration of a derecho-producing convective system after an initial event occurs. Copyright

  1. Quasi-steady-state air plasma channel produced by a femtosecond laser pulse sequence

    PubMed Central

    Lu, Xin; Chen, Shi-You; Ma, Jing-Long; Hou, Lei; Liao, Guo-Qian; Wang, Jin-Guang; Han, Yu-Jing; Liu, Xiao-Long; Teng, Hao; Han, Hai-Nian; Li, Yu-Tong; Chen, Li-Ming; Wei, Zhi-Yi; Zhang, Jie

    2015-01-01

    A long air plasma channel can be formed by filamentation of intense femtosecond laser pulses. However, the lifetime of the plasma channel produced by a single femtosecond laser pulse is too short (only a few nanoseconds) for many potential applications based on the conductivity of the plasma channel. Therefore, prolonging the lifetime of the plasma channel is one of the key challenges in the research of femtosecond laser filamentation. In this study, a unique femtosecond laser source was developed to produce a high-quality femtosecond laser pulse sequence with an interval of 2.9 ns and a uniformly distributed single-pulse energy. The metre scale quasi-steady-state plasma channel with a 60–80 ns lifetime was formed by such pulse sequences in air. The simulation study for filamentation of dual femtosecond pulses indicated that the plasma channel left by the previous pulse was weakly affected the filamentation of the next pulse in sequence under our experimental conditions. PMID:26493279

  2. Equation of state studies of warm dense matter samples heated by laser produced proton beams

    NASA Astrophysics Data System (ADS)

    Hoarty, D. J.; Guymer, T.; James, S. F.; Gumbrell, E.; Brown, C. R. D.; Hill, M.; Morton, J.; Doyle, H.

    2012-03-01

    Heating of matter by proton beams produced by short pulse, laser-solid target interaction has been demonstrated over the last ten years by a number of workers. In the work described in this paper heating by a pulse of laser produced protons has been combined with high-resolution soft x-ray radiography to record the expansion of thin wire targets. Analysis of the radiographs yields material properties in the warm dense matter regime. These measurements imply initial temperatures in the experimental samples over a range from 14 eV up to 40 eV; the sample densities varied from solid to a tenth solid density. Assuming an adiabatic expansion after the initial proton heating phase isentropes of the aluminium sample material were inferred and compared to tabulated data from the SESAME equation of state library. The proton spectrum was also measured using calibrated magnetic spectrometers and radiochromic film. The accuracy of the technique used to infer material data is discussed along with possible future development.

  3. New approach for selecting pectinase producing mutants of Aspergillus niger well adapted to solid state fermentation.

    PubMed

    Antier, P; Minjares, A; Roussos, S; Viniegra-González, G

    1993-01-01

    The aim of this paper is to review and study a new approach for improving strains of Aspergillus niger specially adapted to produce pectinases by Solid State Fermentation (SSF) with materials having low levels of water activity (a(w)), i.e., coffee pulp. Special emphasis is placed on the use of two antimetabolic compounds: 2-deoxy-glucose (DG) and 2,4-dinitro-phenol (DNP) combined with a water depressant (ethylene glycol = EG) in order to put strong selection pressures on UV treated spores from parental strain C28B25 isolated from a coffee plantation. Such a strain was found to be DG sensitive. Results suggested the existence of a reciprocal relation between adaptation of isolated strains to SSF or to Submerged Fermentation (SmF) systems. Preliminary physiological analysis of isolated strains showed that at least some few initially DG resistant mutants could revert to DG sensitive phenotype but conserving increased pectinase production. Also it was found that phenotype for DNP resistance could be associated to changes of DG resistance. Finally, it was found that low levels of a(w) produced by adding 15% EG to agar plates, were a significant selection factor for strains well adapted to SSF system.

  4. EDITORIAL: New materials with high spin polarization: half-metallic Heusler compounds

    NASA Astrophysics Data System (ADS)

    Felser, Claudia; Hillebrands, Burkard

    2007-03-01

    resolution measurements of the valence band close to the Fermi energy indicate the existence of the gap in the minority states for all investigated Co2Fe1 - xMnxSi compounds. Other Co2 Heusler compounds are also possible candidates for magneto-electronic devices. Miura et al [21] have found that the disorder between Co and Y atoms correlates with the total valence electron charges around Y atom and have predicted that Ti-based compounds are better than Cr-, Mn- and Fe-based compounds in preventing the atomic disorder between Co and Y atoms. Kandpal et al have therefore investigated the electronic structure and disordering effects in Co2TiSn using local probes, 119Sn Mössbauer spectroscopy and 59Co nuclear magnetic resonance spectroscopy. They found that the sample possesses up to 10% of antisite (Co/Ti) disordering, a disorder that does not destroy the half-metallic character of this material. We hope that this Cluster of papers will help to stimulate and push forward the research of materials with high spin polarization. References [1] Sakuraba Y, Hattori M, Oogane M, Ando Y, Kato H, Sakuma A, Miyazaki T and Kubota H 2006 Giant tunneling magnetoresistance in Co2MnSi/Al-O/Co2MnSi magnetic tunnel junctions Appl. Phys. Lett. 88 192508 [2] S Wurmehl, Fecher G H, Kandpal H C, Ksenofontov V, Felser C, and Lin H-J 2006 Investigation of Co2FeSi: the Heusler compound with highest Curie temperature and magnetic moment Appl. Phys. Lett. 88 032503 [3] Tezuka N, Ikeda N, Sugimoto S and Inomata K 2006 175% TMR at room temperature and high thermal stability using Co2FeAl0.5Si0.5 full-Heusler alloy electrodes Appl. Phys. Lett. 89 252508 [4] Block T, Felser C, Jakob G, Ensling J, Mühling B, Gütlich P, Cava R J 2003 Large negative magnetoresistance effects in Co2Cr0.6Fe0.4Al J. Solid State Chem. 176 646 [5] Marukame T, Ishikawa T, Matsuda K I, Uemura T and Yamamoto M 2006 High tunnel magnetoresistance in fully epitaxial magnetic tunnel junctions with a full-Heusler alloy Co2Cr0.6Fe0.4Al

  5. Current state and perspectives of producing biodiesel‐like compounds by biotechnology

    PubMed Central

    Uthoff, Stefan; Bröker, Daniel; Steinbüchel, Alexander

    2009-01-01

    Summary The global demand for crude oil is expected to continue to rise in future while simultaneously oil production is currently reaching its peak. Subsequently, rising oil prices and their negative impacts on economy, together with an increased environmental awareness of our society, directed the focus also on the biotechnological production of fuels. Although a wide variety of such fuels has been suggested, only the production of ethanol and biodiesel has reached a certain economic feasibility and volume, yet. This review focuses on the current state and perspectives of biotechnological production of biodiesel‐like compounds. At present by far most of the produced biodiesel is obtained by chemical transesterification reactions, which cannot meet the demands of a totally ‘green’ fuel production. Therefore, also several biotechnological biodiesel production processes are currently being developed. Biotechnological production can be achieved by purified enzymes in the soluble state, which requires cost‐intensive protein preparation. Alternatively, enzymes could be immobilized on an appropriate matrix, enabling a reuse of the enzyme, although the formation of by‐products may provide difficulties to maintain the enzyme activity. Processes in presence of organic solvents like t‐butanol have been developed, which enhance by‐product solubility and therefore prevent loss of enzyme activity. As another approach the application of whole‐cell catalysis for the production of fatty acid ethyl esters, which is also referred to as ‘microdiesel’, by recombinant microorganisms has recently been suggested. PMID:21255288

  6. Current state and perspectives of producing biodiesel-like compounds by biotechnology.

    PubMed

    Uthoff, Stefan; Bröker, Daniel; Steinbüchel, Alexander

    2009-09-01

    The global demand for crude oil is expected to continue to rise in future while simultaneously oil production is currently reaching its peak. Subsequently, rising oil prices and their negative impacts on economy, together with an increased environmental awareness of our society, directed the focus also on the biotechnological production of fuels. Although a wide variety of such fuels has been suggested, only the production of ethanol and biodiesel has reached a certain economic feasibility and volume, yet. This review focuses on the current state and perspectives of biotechnological production of biodiesel-like compounds. At present by far most of the produced biodiesel is obtained by chemical transesterification reactions, which cannot meet the demands of a totally 'green' fuel production. Therefore, also several biotechnological biodiesel production processes are currently being developed. Biotechnological production can be achieved by purified enzymes in the soluble state, which requires cost-intensive protein preparation. Alternatively, enzymes could be immobilized on an appropriate matrix, enabling a reuse of the enzyme, although the formation of by-products may provide difficulties to maintain the enzyme activity. Processes in presence of organic solvents like t-butanol have been developed, which enhance by-product solubility and therefore prevent loss of enzyme activity. As another approach the application of whole-cell catalysis for the production of fatty acid ethyl esters, which is also referred to as 'microdiesel', by recombinant microorganisms has recently been suggested. © 2009 The Authors. Journal compilation © 2009 Society for Applied Microbiology and Blackwell Publishing Ltd.

  7. Intermediate crystalline states produced by isothermal annealing of sputter-deposited a-Si films

    NASA Astrophysics Data System (ADS)

    Akazawa, Housei

    2005-02-01

    The crystalline states produced by isothermally annealing sputter-deposited hydrogen-free amorphous-Si (a-Si) films greatly differ from those of a-Si :H films. Strained network and numerous vacancies in the a-Si film are indicated by the ⟨ɛ2⟩ spectrum. Annealing the sample at temperatures between 300 and 550°C relaxes the strained network due to local exchanges of Si-Si bond while maintaining the amorphous state. Self-assembly of hemispherical grains of microcrystalline Si on the film surface occurs during the onset of crystallization (600°C ). At a slightly elevated temperature of 690°C, the cohesion of Si atoms in the film creates nanocrystalline Si (2-nm diameter), which directly corresponds to the emergence of the absorption peak feature below 3eV in the ⟨ɛ2⟩ spectrum. Dense voids at the interfacial region severely limit the range of solid phase epitaxy, thus facilitating preferential nucleation in the film.

  8. EPR and Mössbauer Spectroscopy, and DFT Analysis of a High-Spin FeIV-oxo Complex

    PubMed Central

    Gupta, Rupal; Lacy, David C.; Bominaar, Emile L.; Borovik, Andrew. S.; Hendrich, Michael P.

    2013-01-01

    The kinetically competent oxidant in non-heme iron enzymes is a high-spin FeIV-oxo species, which are not as well characterized as the intermediate-spin species of heme systems. The present work gives a detailed characterization of the structurally similar [FeIVH3buea(O)]-, [FeIIIH3buea(O)]2- and [FeIIIH3buea(OH)]- (H3buea = tris[(N'-tert-butylureaylato)-N-ethylene]aminato) complexes using Mössbauer and dual-frequency/dual-mode electron paramagnetic resonance (EPR) spectroscopies. The [FeIVH3buea(O)]- complex has a high-spin (S = 2) configuration imposed from the C3-symmetric ligand. EPR spectroscopy of the [FeIVH3buea(O)]- complex is the first documented example of an EPR signal from an FeIV-oxo complex, demonstrating the ability to detect and quantify FeIV species with EPR spectroscopy. Quantitative simulations allowed determination of the zero-field parameter, D = +4.7 cm-1, and the species concentration. Density functional theory calculations of the zero-field parameter are found to be in agreement with the experimental value and indicate the major contribution to the D-value is from spin–orbit coupling of the ground state with an excited S = 1 electronic configuration at 1.2 eV. 17O isotope enrichment experiments allowed a determination of the hyperfine constant 170Az = 10 MHz for [FeIVH3buea(O)]- and 170Ay = 8 MHz, 170Az = 12 MHz for [FeIIIH3buea(OH)]-. The isotropic hyperfine constant (170Aiso = -16.8 MHz) was derived from the experimental value to allow a quantitative determination of the spin polarization (ρp = 0.56) of the oxo p-orbitals of the Fe-oxo bond in [FeIVH3buea(O)]-. This is the first experimental determination for non-heme complexes, and indicates significant covalency in the Fe-oxo bond. High-field Mössbauer spectroscopy gave an 57Fe Adip tensor of (+5.6, +5.3, -10.9) MHz and Aiso = -25.9 MHz for the [FeIVH3buea(O)]- complex, and DFT calculations are in agreement with the nuclear parameters of the complex. PMID:22574962

  9. Birth malformations and other adverse perinatal outcomes in four U.S. Wheat-producing states.

    PubMed Central

    Schreinemachers, Dina M

    2003-01-01

    Chlorophenoxy herbicides are widely used in the United States and Western Europe for broadleaf weed control in grain farming and park maintenance. Most of the spring and durum wheat produced in the United States is grown in Minnesota, Montana, North Dakota, and South Dakota, with more than 85% of the acreage treated with chlorophenoxy herbicides such as 2,4-dichlorophenoxyacetic acid (2,4-D) and 4-chloro-2-methylphenoxyacetic acid (MCPA). Rates of adverse birth outcomes in rural, agricultural counties of these states during 1995-1997 were studied by comparing counties with a high proportion of wheat acreage and those with a lower proportion. Information routinely collected and made available by federal agencies was used for this ecologic study. Significant increases in birth malformations were observed for the circulatory/respiratory category for combined sexes [odds ratio (OR) = 1.65; 95% confidence interval (CI), 1.07-2.55]. A stronger effect was observed for the subcategory, which excluded heart malformations (OR = 2.03; 95% CI, 1.14-3.59). In addition, infants conceived during April-June--the time of herbicide application--had an increased chance of being diagnosed with circulatory/respiratory (excluding heart) malformations compared with births conceived during other months of the year (OR = 1.75; 95% CI, 1.09-2.80). Musculoskeletal/integumental anomalies increased for combined sexes in the high-wheat counties (OR = 1.50; 95% CI, 1.06-2.12). Infant death from congenital anomalies significantly increased in high-wheat counties for males (OR = 2.66; 95% CI, 1.52-4.65) but not for females (OR = 0.48; 95% CI, 0.20-1.15). These results are especially of concern because of widespread use of chlorophenoxy herbicides. PMID:12842783

  10. Pressure and temperature induced high spin-low spin phase transition: Macroscopic and microscopic consideration

    NASA Astrophysics Data System (ADS)

    Levchenko, G.; Khristov, A.; Kuznetsova, V.; Shelest, V.

    2014-08-01

    The behavior under pressure of the high spin-low spin phase transition in the coordination compounds containing 3d ions is analyzed using thermodynamic and microscopic approaches. For thermodynamic approach the mean field model with interactions between spin-crossover molecules is considered. Microscopic model takes into account the interaction of d electrons of the transition metal ions with full symmetric distortions of the ligands. The relationship of the thermodynamic interaction parameters with microscopic ones is installed and shown how the quantum-mechanical interactions form the cooperativity of the system. Within the microscopic model the temperature and pressure dependences of the high spin fraction in 2-D compounds {Fe(3-Fpy)2[M(CN)4]} (M=Pd, Pt) are simulated and microscopic parameters are evaluated. It is concluded that different experimental behaviors of the temperature and pressure induced spin transitions are determined by different variations of the inelastic and elastic energies under pressure, and vibrational component of the free energy drives the ST equally with electronic part.

  11. Management of Reclaimed Produced Water in the Rocky Mountain States Enhanced with the Expanded U.S. Geological Survey Produced Waters Geochemical Database

    NASA Astrophysics Data System (ADS)

    Gans, K. D.; Blondes, M. S.; Reidy, M. E.; Conaway, C. H.; Thordsen, J. J.; Rowan, E. L.; Kharaka, Y. K.; Engle, M.

    2016-12-01

    The Rocky Mountain states; Wyoming, Colorado, Montana, New Mexico and Utah produce annually approximately 470,000 acre-feet (3.66 billion barrels) of produced water - water that coexists with oil and gas and is brought to the surface with the pumping of oil and gas wells. Concerns about severe drought, groundwater depletion, and contamination have prompted petroleum operators and water districts to examine the recycling of produced water. Knowledge of the geochemistry of produced waters is valuable in determining the feasibility of produced water reuse. Water with low salinity can be reclaimed for use inside and outside of the petroleum industry. Since a great proportion of petroleum wells in the Rocky Mountain states, especially coal-bed methane wells, have produced water with relatively low salinity (generally <10,000-40,000 mg/L TDS), reclaiming produced water could be important as a drought mitigation strategy, through the irrigation of farmland, blending of low salinity waters with existing drainage basins, re-use in the petroleum industry for hydraulic fracturing or enhanced oil recovery, and even for municipal uses, such as drinking water. The USGS Produced Waters Geochemical Database, available at http://eerscmap.usgs.gov/pwapp, has 60,000 data points in this region (this includes 35,000 new data points added to the 2002 database) and will facilitate studies on the management of produced water for reclamation in the Rocky Mountain region. Expanding on the USGS 2002 database, which contains geochemical analyses of major ions and total dissolved solids, the new data also include geochemical analyses of minor ions and stable isotopes. We have added an interactive web map application which allows the user to filter data on chosen fields (e.g. TDS < 35,000 mg/L). Using the web map application as well as more in-depth investigation on the full data set can provide critical insight for better management of produced waters in water-constrained regions of the Rocky

  12. Redox Thermodynamics of High-Spin and Low-Spin Forms of Chlorite Dismutases with Diverse Subunit and Oligomeric Structures

    PubMed Central

    2012-01-01

    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. PMID:23126649

  13. Pentylenetetrazol produces a state-dependent conditioned place aversion to alcohol withdrawal in mice.

    PubMed

    Chester, Julia A; Coon, Laran E

    2010-04-01

    The purpose of this study was to determine if aversive effects of alcohol withdrawal could be detected in mice using the place conditioning procedure and whether the GABA(A) receptor antagonist, pentylenetetrazol (PTZ), would increase the aversive effects of alcohol withdrawal and increase the probability of detecting conditioned place aversion. Subjects were alcohol-naïve mice from a specific line selectively bred for low alcohol preference (LAP1; n=91) and were assigned to three groups: alcohol withdrawal, PTZ alone, and PTZ+alcohol withdrawal. On four trials, mice received either a 4.0 g/kg intraperitoneal (i.p.) injection of alcohol (alcohol withdrawal, PTZ+alcohol withdrawal groups) or saline (PTZ group) 8 h prior to being placed on a distinctive floor texture for a 30-min conditioning session. Five minutes before these sessions, mice in the PTZ and PTZ+alcohol withdrawal groups received PTZ (5.0 mg/kg; i.p.) and the alcohol withdrawal group received saline. On intervening days mice received two saline injections at the same time points prior to being placed on a different floor texture. Post-conditioning floor preference was assessed in two 60-min tests; the first test was drug-free and the second test was state-dependent. Neither alcohol withdrawal nor PTZ produced significant place conditioning. The PTZ+alcohol withdrawal group showed a significant place aversion during the state-dependent test. These data suggest that the combined stimulus properties of PTZ and alcohol withdrawal facilitated the expression of conditioned place aversion to alcohol withdrawal. 2010 Elsevier Inc. All rights reserved.

  14. Chitooligomers preparation by chitosanase produced under solid state fermentation using shrimp by-products as substrate.

    PubMed

    Nidheesh, T; Pal, Gaurav Kumar; Suresh, P V

    2015-05-05

    Solid state fermentation (SSF) conditions were statistically optimized for the production of chitosanase by Purpureocillium lilacinum CFRNT12 using shrimp by-products as substrate. Central composite design and response surface methodology were applied to evaluate the effect of variables and their optimization. Incubation temperature, incubation time, concentration of inoculum and yeast extract were found to influence the chitosanase production significantly. The R(2) value of 0.94 indicates the aptness of the model. The level of variables for optimal production of chitosanase was 32 ± 1°C temperature, 96 h incubation, 10.5% (w/v) inoculum, 1.05% (w/w) yeast extract and 65% (w/w) moisture content. The chitosanase production was found to increase from 2.34 ± 0.07 to 41.78 ± 0.73 units/g initial dry substrate after optimization. The crude chitosanase produced 4.43 mM of chitooligomers as exclusive end product from colloidal chitosan hydrolysis. These results indicate the potential of P. lilacinum CFRNT12 for the chitosanase production employing cost effective SSF using shrimp by-products.

  15. Spin-orbit contributions in high-spin nitrenes/carbenes: a hybrid CASSCF/MRMP2 study of zero-field splitting tensors.

    PubMed

    Sugisaki, Kenji; Toyota, Kazuo; Sato, Kazunobu; Shiomi, Daisuke; Kitagawa, Masahiro; Takui, Takeji

    2010-10-04

    Zero-field splitting (ZFS) tensors (D tensors) of organic high-spin oligonitrenes/oligocarbenes up to spin-septet are quantitatively determined on the basis of quantum chemical calculations. The spin-orbit contributions, D(SO) tensors are calculated in terms of a hybrid CASSCF/MRMP2 approach, which was recently proposed by us. The spin-spin counterparts, D(SS) tensors are computed based on McWeeny-Mizuno's equation in conjunction with the RODFT spin densities. The present calculations show that more than 10% of ZFS arises from spin-orbit interactions in the high-spin nitrenes under study. Contributions of spin-bearing site-site interactions are estimated with the aid of a semi-empirical model for the D tensors and found to be ca. 5% of the D(SO) tensor. The analysis of intermediate states reveal that the largest contributions to the calculated D(SO) tensors are attributed to intra-site spin flip excitations and delocalized π and π* orbitals play an important role in the inter-site spin-orbit interactions.

  16. Deformation increase of high-spin core-excited isomers in the astatine nuclei

    SciTech Connect

    Scheveneels, G.; Hardeman, F.; Neyens, G.; Coussement, R. )

    1991-06-01

    Quadrupole moments of six high-spin isomers in the At isotopes have been measured with the level-mixing-spectroscopy method: {sup 208}At(16{sup {minus}}), {sup 209}At(29/2{sup +}), {sup 210}At(19{sup +},15{sup {minus}}), {sup 211}At(39/2{sup {minus}},29/2{sup +}). The results show that level mixing spectroscopy is a promising technique to determine quadrupole moments of isomers that are difficult to measure by other in-beam hyperfine interaction methods. A large increase of the quadrupole moment is observed if neutrons are excited across or removed from the {ital N}=126 shell closure. This behavior is explained in terms of an enhanced core softness for fewer core neutrons; the aligned valence particles, moving in equatorial orbits, then easily polarize the core towards oblate deformation.

  17. High spin polarization in CoFeMnGe equiatomic quaternary Heusler alloy

    SciTech Connect

    Bainsla, Lakhan; Suresh, K. G.; Nigam, A. K.; Manivel Raja, M.; Varaprasad, B. S. D. Ch. S.; Takahashi, Y. K.; Hono, K.

    2014-11-28

    We report the structure, magnetic property, and spin polarization of CoFeMnGe equiatomic quaternary Heusler alloy. The alloy was found to crystallize in the cubic Heusler structure (prototype LiMgPdSn) with considerable amount of DO{sub 3} disorder. Thermal analysis result indicated the Curie temperature is about 750 K without any other phase transformation up to melting temperature. The magnetization value was close to that predicted by the Slater-Pauling curve. Current spin polarization of P = 0.70 ± 0.01 was deduced using point contact andreev reflection measurements. The temperature dependence of electrical resistivity has been fitted in the temperature range of 5–300 K in order to check for the half metallic behavior. Considering the high spin polarization and Curie temperature, this material appears to be promising for spintronic applications.

  18. Thermostable invertases from Paecylomyces variotii produced under submerged and solid-state fermentation using agroindustrial residues.

    PubMed

    Giraldo, Marielle Aleixo; da Silva, Tony Márcio; Salvato, Fernanda; Terenzi, Héctor Francisco; Jorge, João Atílio; Guimarães, Luis Henrique Souza

    2012-02-01

    The filamentous fungus Paecylomices variotii was able to produce high levels of cell extract and extracellular invertases when grown under submerged fermentation (SbmF) and solid-state fermentation, using agroindustrial products or residues as substrates, mainly soy bran and wheat bran, at 40°C for 72 h and 96 h, respectively. Addition of glucose or fructose (≥1%; w/v) in SbmF inhibited enzyme production, while the addition of 1% (w/v) peptone as organic nitrogen source enhanced the production by 3.7-fold. However, 1% (w/v) (NH(4))(2)HPO(4) inhibited enzyme production around 80%. The extracellular form was purified until electrophoretic homogeneity (10.5-fold with 33% recovery) by DEAE-Fractogel and Sephacryl S-200 chromatography. The enzyme is a monomer with molecular mass of 102 kDa estimated by SDS-PAGE with carbohydrate content of 53.6%. Optima of temperature and pH for both, extracellular and cell extract invertases, were 60°C and 4.0-4.5, respectively. Both invertases were stable for 1 h at 60°C with half-lives of 10 min at 70°C. Mg(2+), Ba(2+) and Mn(2+) activated both extracellular and cell extract invertases from P. variotii. The kinetic parameters K(m) and V(max) for the purified extracellular enzyme corresponded to 2.5 mM and 481 U/mg prot(-1), respectively.

  19. On the Sensitivity of X-ray Core Spectroscopy to Changes in Metal Ligation: A Systematic Study of Low-Coordinate High-Spin Ferrous Complexes

    PubMed Central

    Chandrasekaran, P.; Chiang, Karen P.; Nordlund, Dennis; Bergmann, Uwe; Holland, Patrick L.; DeBeer, Serena

    2014-01-01

    In order to assess the sensitivity and complementarity of X-ray absorption and emission spectroscopies for determining changes in the metal ligation sphere, a systematic experimental and theoretical study of iron model complexes has been carried out. A series of high-spin ferrous complexes, in which the ligation sphere has been varied from a three coordinate complex, [LtBuFe(SPh)] (1) (where, LtBu = bulky β-diketiminate ligand; SPh = Phenyl thiolate) to four-coordinate complexes [LtBuFe(SPh)(X)], (where, X = CNtBu (2); 1-Methylimidazole (3); or N,N-dimethylformamide (DMF) (4)), has been investigated using a combination of Fe K-edge X-ray absorption (XAS) and Kβ X-ray emission (XES) spectroscopies. The Fe K XAS pre-edge and edge of all four complexes are consistent with a high-spin ferrous assignment, with the largest differences in the pre-edge intensities attributed to changes in covalency of the fourth coordination site. The X-ray emission spectra show pronounced changes in the valence to core region (V2C) as the identity of the coordinated ligand is varied. The experimental results have been correlated to DFT calculations, to understand key molecular orbital contributions to the observed absorption and emission features. The calculations also have been extended to a series of hypothetical high-spin iron complexes to understand the sensitivity of XAS and XES techniques to different ligand protonation states ([LtBuFeII(SPh)(NHn)]3-n (n = 3, 2, 1, 0)), metal oxidation states [LtBuFe(SPh)(N)]n- (n = 3, 2, 1), and changes in the ligand identity [LtBuFeIV(SPh)(X)]n- (X = C4-, N3-, O2-; n = 2, 1, 0). This study demonstrates that XAS pre-edge data have greater sensitivity to changes in oxidation state, while valence to core (V2C) XES data provide a more sensitive probe of ligand identity and protonation state. The combination of multiple X-ray spectroscopic methods with DFT results thus has the potential to provide for detailed characterization of complex inorganic

  20. Properties of the low-spin high-spin interface during the relaxation of spin-crossover materials, investigated through an electro-elastic model

    SciTech Connect

    Slimani, A.; Boukheddaden, K. Varret, F.; Nishino, M.; Miyashita, S.

    2013-11-21

    The present work is devoted to the spatio-temporal investigations of spin-crossover lattices during their thermal relaxation from high- to low-spin state. The analysis is performed using Monte Carlo simulations on a distortable 2D lattice the sites of which are occupied by high-spin (HS) or low-spin (LS) atoms. The lattice is circular in shape and the HS to LS transformation results in single domain nucleation followed by growth and propagation processes. The evolution of the LS:HS interface is monitored during the relaxation process, through the mapping of spin states, displacement fields, local stresses, and elastic energy. The results show a curved interface, the curvature of which is reversed at the mid-transformation. The local stresses and elastic energy peak at the vicinity of the HS:LS interface, with sizeable dependence upon the position along the front line which evidences the edge effects.

  1. Static quadrupole moment of high-spin isomers in the doubly-odd {sup 214}Fr nucleus

    SciTech Connect

    Neyens, G.; Van Asbroeck, I.; Coussement, R.

    1995-06-01

    We have determined the spectroscopic quadrupole moment of two high-spin isomers ({ital I}=11 {h_bar} and {ital I}=32 {h_bar}) which have recently been identified in the doubly-odd {sup 214}Fr nucleus. The data have been extracted from a series of former level mixing spectroscopy (LEMS) measurements which had been performed to measure quadrupole moments of high-spin isomers in {sup 211,212,213}Fr isotopes. The quadrupole frequencies were measured in natural and enriched poly- and single-crystalline T1 at different temperatures.

  2. Reported foodborne outbreaks due to fresh produce in the United States and European Union: trends and causes.

    PubMed

    Callejón, Raquel M; Rodríguez-Naranjo, M Isabel; Ubeda, Cristina; Hornedo-Ortega, Ruth; Garcia-Parrilla, M Carmen; Troncoso, Ana M

    2015-01-01

    The consumption of fruit and vegetables continues to rise in the United States and European Union due to healthy lifestyle recommendations. Meanwhile, the rate of foodborne illness caused by the consumption of these products remains high in both regions, representing a significant public health and financial issue. This study addresses the occurrence of reported foodborne outbreaks associated with fresh fruits and vegetables consumption in the United States and European Union during the period 2004-2012, where data are available. Special attention is paid to those pathogens responsible for these outbreaks, the mechanisms of contamination, and the fresh produce vehicles involved. Norovirus is shown to be responsible for most of the produce-related outbreaks, followed by Salmonella. Norovirus is mainly linked with the consumption of salad in the United States and of berries in the European Union, as demonstrated by the Multiple Correspondence Analysis (MCA). Salmonella was the leading cause of multistate produce outbreaks in the United States and was the pathogen involved in the majority of sprouts-associated outbreaks. As is reflected in the MCA, the pattern of fresh produce outbreaks differed in the United States and European Union by the type of microorganism and the food vehicle involved.

  3. Molecular spectroscopy for producing ultracold ground-state NaRb molecules

    NASA Astrophysics Data System (ADS)

    Wang, Dajun; Guo, Mingyang; Zhu, Bing; Lu, Bo; Ye, Xin; Wang, Fudong; Vexiau, Romain; Bouloufa-Maafa, Nadia; Quéméner, Goulven; Dulieu, Olivier

    2016-05-01

    Recently, we have successfully created an ultracold sample of absolute ground-state NaRb molecules by two-photon Raman transfer of weakly bound Feshbach molecules. Here we will present the detailed spectroscopic investigations on both the excited and the rovibrational ground states for finding the two-photon path. For the excited state, we focus on the A1Σ+ /b3 Π singlet and triplet admixture. We discovered an anomalously strong coupling between the Ω =0+ and 0- components which renders efficient population transfer possible. In the ground state, the pure nuclear hyperfine levels have been clearly resolved, which allows us to create molecules in the absolute ground state directly with Raman transfer. This work is jointly supported by Agence Nationale de la Recherche (#ANR-13- IS04-0004-01) and Hong Kong Research Grant Council (#A-CUHK403/13) through the COPOMOL project.

  4. Pressure induced high spin-low spin transition in FeSe superconductor studied by x-ray emission spectroscopy and ab initio calculations

    SciTech Connect

    Kumar, Ravhi S.; Zhang, Yi; Xiao, Yuming; Baker, Jason; Cornelius, Andrew; Veeramalai, Sathishkumar; Chow, Paul; Chen, Changfeng; Zhao, Yusheng

    2011-09-20

    FeSe is a simple binary system in the iron based superconducting family and exhibits a significant pressure induced increase in the superconducting transition temperature (T{sub c}). In addition to pressure effect, spin fluctuations, magnetic ordering, and crystal structure all play vital roles in altering T{sub c}. Even though various experiments and theoretical simulations explain the connection among them and superconductivity, the interplay between these important parameters is still not clearly understood. Here, we report the pressure effect on the spin state of Fe in FeSe superconductor studied using synchrotron x-ray emission spectroscopy at ambient and low temperatures down to 8 K near T{sub c}. Pressure induced high spin to low spin transition was observed at both ambient and low temperatures with continuous suppression of Fe magnetic moments under increasing pressure. The spin transition is closely related to the pressure induced tetragonal to orthorhombic structural transition.

  5. Study of Ru{sub 2}VGe and Ru{sub 2}VSb: High-spin polarized and half-metallic Heusler alloys

    SciTech Connect

    Bhat, Idris Hamid; Gupta, Dinesh C.

    2015-06-24

    Electronic and magnetic properties of Ru{sub 2}VGe and Ru{sub 2}VSb have been investigated by ab-initio. The optimized equilibrium lattice parameters were found to be 6.032 Å for Ru{sub 2}VGe and 6.272 Å for Ru{sub 2}VSb. Both the materials have ferromagnetic ground states and V mainly contributes to the magnetic properties in these materials. The highly spin-polarized half-metallic materials have integral magnetic moments of 1.0 µ{sub B} for Ru{sub 2}VGe and 2.0 µ{sub B} for Ru{sub 2}VSb with an energy gap of 0.095 eV for Ru2VGe and 0.186 eV for Ru{sub 2}VSb in the spin-down channel.

  6. High-spin structure of sup 189 Tl: Role of h sub 9/2 protons in the prolate minimum of light Hg isotopes

    SciTech Connect

    Porquet, M.; Kreiner, A.J.; Hannachi, F.; Vanin, V.; Bastin, G.; Bourgeois, C.; Davidson, J.; Debray, M.; Falcone, G.; Korichi, A.; Mosca, H.; Perrin, N.; Sergolle, H.; Beck, F.A.; Merdinger, J. Departamento de Fisica, Comision Nacional de Energia Atomica, 1429 Buenos Aires Centre de Recherches Nucleaires, 67037 Strasbourg Instituto de Fisica, Universidade de Sao Paulo, 1000 Sao Paulo Institut de Physique Nucleaire, 91406 Orsay )

    1991-12-01

    High-spin states in {sup 189}Tl have been populated through the {sup 165}Ho({sup 28}Si,4{ital n}) reaction and studied with in-beam {gamma}-ray spectroscopy techniques. Both oblate and prolate structures associated with the {ital i}13/2 proton orbit are confirmed and extended to higher spins (19/2 and 41/2, respectively). However, only the oblate structure related to the {pi}{ital h}9/2 has been observed meaning that the associated prolate structure is nonyrast contrary to expectation. This experimental result points clearly to a large amplitude of ({pi}{ital h}9/2){sup 2} in the wave function of the prolate minimum of {sup 188}Hg.

  7. A conservation ontology and knowledge base to support delivery of technical assistance to agricultural producers in the united states

    USDA-ARS?s Scientific Manuscript database

    Information systems supporting the delivery of conservation technical assistance by the United States Department of Agriculture (USDA) to agricultural producers on working lands have become increasingly complex over the past 25 years. They are constrained by inconsistent coordination of domain knowl...

  8. 19 CFR 10.552 - Information sharing by CBP regarding textile and apparel goods produced in the United States.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Information sharing by CBP regarding textile and... Determinations § 10.552 Information sharing by CBP regarding textile and apparel goods produced in the United States. (a) Documents or information in the possession of U.S. enterprises. Upon written request from...

  9. A Proposal to Produce Velocity-Selected and State-Selected Molecular Beams Using the Ballistic Effect

    DTIC Science & Technology

    1992-07-01

    O i ..C / ,ONll OF.h.O AGL14CY |i Ol(’r NUItIILIl ., *Yap ’nalicsInc. , Lexington, Massachusetts 02173 Reprinted from The Journal of Chemical Physics , Volume...Reprinted from THE JOURNAL OF CHEMICAL PHYSICS VOLUME 97 NUMBER 1 1 JULY 1992 A proposal to produce velocity-selected and state-selected molecular

  10. A high proportion of NX-2 mycotoxin producing strains are found among Fusarium graminearum isolates from northeastern New York State

    USDA-ARS?s Scientific Manuscript database

    Fusarium graminearum, a fungal pathogen of wheat, barley, and corn, produces a variety of trichothecene mycotoxins that are important as aggressiveness factors and as seed contaminants reducing grain quality. A previous survey of the pathogen in New York State identified variation in genes indicativ...

  11. 30 CFR 519.415 - How will bonus and royalty credits affect revenues allocated to Gulf producing States?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... revenues allocated to Gulf producing States? 519.415 Section 519.415 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT DISTRIBUTION AND DISBURSEMENT...(c) of the Gulf of Mexico Energy Security Act are used to pay bonuses or royalties on leases in the...

  12. 30 CFR 519.418 - When will funds be disbursed to Gulf producing States and eligible coastal political subdivisions?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false When will funds be disbursed to Gulf producing States and eligible coastal political subdivisions? 519.418 Section 519.418 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT DISTRIBUTION AND...

  13. 30 CFR 519.413 - How will the coastal political subdivisions of Gulf producing States share in the qualified OCS...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false How will the coastal political subdivisions of Gulf producing States share in the qualified OCS revenues? 519.413 Section 519.413 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT DISTRIBUTION...

  14. 30 CFR 519.415 - How will bonus and royalty credits affect revenues allocated to Gulf producing States?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... revenues allocated to Gulf producing States? 519.415 Section 519.415 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT DISTRIBUTION AND DISBURSEMENT...(c) of the Gulf of Mexico Energy Security Act are used to pay bonuses or royalties on leases in the...

  15. 30 CFR 519.413 - How will the coastal political subdivisions of Gulf producing States share in the qualified OCS...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false How will the coastal political subdivisions of Gulf producing States share in the qualified OCS revenues? 519.413 Section 519.413 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT DISTRIBUTION...

  16. 30 CFR 519.418 - When will funds be disbursed to Gulf producing States and eligible coastal political subdivisions?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false When will funds be disbursed to Gulf producing States and eligible coastal political subdivisions? 519.418 Section 519.418 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT DISTRIBUTION AND...

  17. 30 CFR 519.413 - How will the coastal political subdivisions of Gulf producing States share in the qualified OCS...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false How will the coastal political subdivisions of Gulf producing States share in the qualified OCS revenues? 519.413 Section 519.413 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT DISTRIBUTION...

  18. 30 CFR 519.415 - How will bonus and royalty credits affect revenues allocated to Gulf producing States?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... revenues allocated to Gulf producing States? 519.415 Section 519.415 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT DISTRIBUTION AND DISBURSEMENT...(c) of the Gulf of Mexico Energy Security Act are used to pay bonuses or royalties on leases in the...

  19. 30 CFR 519.418 - When will funds be disbursed to Gulf producing States and eligible coastal political subdivisions?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false When will funds be disbursed to Gulf producing States and eligible coastal political subdivisions? 519.418 Section 519.418 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT DISTRIBUTION AND...

  20. Characterization of Shiga toxin-producing Escherichia coli associated with two multi-state foodborne outbreaks in 2006

    USDA-ARS?s Scientific Manuscript database

    In the fall of 2006 two multi-state outbreaks of E. coli serotype O157:H7 infection occurred that involved contaminated spinach and contaminated lettuce. In this study, we compare 7 Shiga toxin-producing isolates associated with those two outbreaks to a collection of food, environmental, and animal ...

  1. Taxonomy and distribution of phenazine-producing Pseudomonas spp. in the dryland agroecosystem of the Inland Pacific Northwest, United States.

    PubMed

    Parejko, James A; Mavrodi, Dmitri V; Mavrodi, Olga V; Weller, David M; Thomashow, Linda S

    2013-06-01

    We investigated the taxonomic placement of phenazine-producing fluorescent Pseudomonas spp. in the Inland Pacific Northwest region of the United States. Five distinct species were identified, two of which were provisionally considered to be new. Agroclimatic zone and soil silt content affected the species diversity across the region.

  2. 19 CFR 10.552 - Information sharing by CBP regarding textile and apparel goods produced in the United States.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Information sharing by CBP regarding textile and apparel goods produced in the United States. 10.552 Section 10.552 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC....

  3. 19 CFR 10.552 - Information sharing by CBP regarding textile and apparel goods produced in the United States.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Information sharing by CBP regarding textile and apparel goods produced in the United States. 10.552 Section 10.552 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC....

  4. 19 CFR 10.552 - Information sharing by CBP regarding textile and apparel goods produced in the United States.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Information sharing by CBP regarding textile and apparel goods produced in the United States. 10.552 Section 10.552 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC....

  5. 19 CFR 10.552 - Information sharing by CBP regarding textile and apparel goods produced in the United States.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Information sharing by CBP regarding textile and apparel goods produced in the United States. 10.552 Section 10.552 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC....

  6. 30 CFR 219.418 - When will funds be disbursed to Gulf producing States and eligible coastal political subdivisions?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When will funds be disbursed to Gulf producing States and eligible coastal political subdivisions? 219.418 Section 219.418 Mineral Resources MINERALS... ROYALTIES, RENTALS, AND BONUSES Oil and Gas, Offshore § 219.418 When will funds be disbursed to...

  7. Dipole-Dipole Interactions of High-spin Paramagnetic Centers in Disordered Systems

    SciTech Connect

    Maryasov, Alexander G.; Bowman, Michael K.; Tsvetkov, Yuri D.

    2007-09-13

    Dipole-dipole interactions between distant paramagnetic centers (PCs) where at least one PC has spin S>1/2 are examined. The results provide a basis for the application of pulsed DEER or PELDOR methods to the measurement of distances between PC involving high-spin species. A projection operator technique based on spectral decomposition of the secular Hamiltonian is used to calculate EPR line splitting caused by the dipole coupling. This allows calculation of operators projecting arbitrary wavefunction onto high PC eigenstates when the eigenvectors of the Hamiltonian are not known. The effective spin vectors-that is, the expectation values for vector spin operators in the PC eigenstates-are calculated. The dependence of these effective spin vectors on the external magnetic field is calculated. There is a qualitative difference between pairs having at least one integer spin (non Karmers PC) and pairs of two half-integer (Kramers PC) spins. With the help of these effective spin vectors, the dipolar lineshape of EPR lines is calculated. Analytical relations are obtained for PCs with spin S=1/2 and 1. The dependence of Pake patterns on variations of zero field splitting, Zeeman energy, temperature and dipolar coupling are illustrated.

  8. High-spin configuration of Mn in Bi2Se3 three-dimensional topological insulator

    NASA Astrophysics Data System (ADS)

    Wolos, Agnieszka; Drabinska, Aneta; Borysiuk, Jolanta; Sobczak, Kamil; Kaminska, Maria; Hruban, Andrzej; Strzelecka, Stanislawa G.; Materna, Andrzej; Piersa, Miroslaw; Romaniec, Magdalena; Diduszko, Ryszard

    2016-12-01

    Electron paramagnetic resonance was used to investigate Mn impurity in Bi2Se3 topological insulator grown by the vertical Bridgman method. Mn in high-spin S=5/2, Mn2+, configuration was detected regardless of the conductivity type of the host material. This means that Mn2+(d5) energy level is located within the valence band, and Mn1+(d6) energy level is outside the energy gap of Bi2Se3. The electron paramagnetic resonance spectrum of Mn2+ in Bi2Se3 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 Bi2Se3 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 Bi2Se3 to BiSe phase.

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

    NASA Astrophysics Data System (ADS)

    Bainsla, Lakhan; Mallick, A. I.; Coelho, A. A.; Nigam, A. K.; Varaprasad, B. S. D. Ch. S.; Takahashi, Y. K.; Alam, Aftab; Suresh, K. G.; Hono, K.

    2015-11-01

    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 (MS) of about 2 μB/f.u. is observed at 8 K under ambient pressure, which is in good agreement with the Slater-Pauling rule. MS 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.

  10. Effects of Imidazole Deprotonation on Vibrational Spectra of High-Spin Iron(II) Porphyrinates

    PubMed Central

    Hu, Chuanjiang; Peng, Qian; Silvernail, Nathan J.; Barabanschikov, Alexander; Zhao, Jiyong; Alp, E. Ercan; Sturhahn, Wolfgang; Sage, J. Timothy; Scheidt, W. Robert

    2013-01-01

    The effects of the deprotonation of coordinated imidazole on the dynamics of five-coordinate high-spin iron(II) porphyrinates have been investigated using nuclear resonance vibrational spectroscopy. Two complexes have been studied in detail with both powder and oriented single-crystal measurements. Changes in the vibrational spectra are clearly related to structural differences in the molecular structures that occur when imidazole is deprotonated. Most modes involving the simultaneous motion of iron and imidazolate are unresolved but the one mode that is resolved is found at higher frequency in the imidazolates. These out-of-plane results are in accord with earlier resonance Raman studies of heme proteins. We also show the imidazole vs. imidazolate differences in the in-plane vibrations that are not accessible to resonance Raman studies. The in-plane vibrations are at lower frequency in the imidazolate derivatives; the doming mode shifts are inconclusive. The stiffness, an experimentally determined force constant that averages the vibrational details to quantify the nearest-neighbor interactions, confirms that deprotonation inverts the relative strengths of axial and equatorial coordination. PMID:23470205

  11. State space parsimonious reconstruction of attractor produced by an electronic oscillator

    NASA Astrophysics Data System (ADS)

    Aguirre, Luis A.; Freitas, Ubiratan S.; Letellier, Christophe; Sceller, Lois Le; Maquet, Jean

    2000-02-01

    This work discusses the reconstruction, from a set of real data, of a chaotic attractor produced by a well-known electronic oscillator, Chua's circuit. The mathematical representation used is a nonlinear differential equation of the polynomial type. One of the contributions of the present study is that structure selection techniques have been applied to help determine the regressors in the model. Models of the chaotic attractor obtained with and without structure selection were compared. The main differences between structure-selected models and complete structure models are: i) the former are more parsimonious that the latter, ii) fixed-point symmetry is guaranteed for the former, iii) for structure-selected models a trivial fixed point is also guaranteed, and iv) the former set of models produce attractors that are topologically closer to the original attractor than those produced by the complete structure models.

  12. Isomers and high-spin structures in the N =81 isotones 135Xe and 137Ba

    NASA Astrophysics Data System (ADS)

    Vogt, A.; Birkenbach, B.; Reiter, P.; Blazhev, A.; Siciliano, M.; Hadyńska-Klek, K.; Valiente-Dobón, J. J.; Wheldon, C.; Teruya, E.; Yoshinaga, N.; Arnswald, K.; Bazzacco, D.; Bowry, M.; 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.; Freeman, S. J.; Fu, B.; Gadea, A.; Geibel, K.; Gelletly, W.; Gengelbach, A.; Giaz, A.; Görgen, A.; Gottardo, A.; Hayes, A. B.; Hess, H.; Hirsch, R.; Hua, H.; John, P. R.; Jolie, J.; Jungclaus, A.; Kaya, L.; Korten, W.; Lee, I. Y.; Leoni, S.; Lewandowski, L.; 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.; Pellegri, L.; Podolyák, Zs.; Pollarolo, G.; Pullia, A.; Queiser, M.; Radeck, F.; Recchia, F.; Regan, P. H.; Rosiak, D.; Saed-Samii, N.; Şahin, E.; Scarlassara, F.; Schneiders, D.; Seidlitz, M.; Siebeck, B.; Sletten, G.; Smith, J. F.; Söderström, P.-A.; Stefanini, A. M.; Steinbach, T.; Stezowski, O.; Szilner, S.; Szpak, B.; Teng, R.; Ur, C.; Vandone, V.; Warner, D. D.; Wiens, A.; Wu, C. Y.; Zell, K. O.

    2017-02-01

    The high-spin structures and isomers of the N =81 isotones 135Xe and 137Ba are investigated after multinucleon-transfer (MNT) and fusion-evaporation reactions. Both nuclei are populated (i) in 136Xe+238U and (ii) 136Xe+208Pb MNT reactions employing the high-resolution Advanced Gamma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA, (iii) in the 136Xe+198Pt MNT reaction employing the γ -ray array GAMMASPHERE in combination with the gas-detector array CHICO, and (iv) via a 11B+130Te fusion-evaporation reaction with the HORUS γ -ray array at the University of Cologne. The high-spin level schemesof 135Xe and 137Ba are considerably extended to higher energies. The 2058-keV (19 /2-) state in 135Xe is identified as an isomer, closing a gap in the systematics along the N =81 isotones. Its half-life is measured to be 9.0(9) ns, corresponding to a reduced transition probability of B (E 2 ,19 /2-→15 /2-) =0.52 (6 ) W.u. The experimentally deduced reduced transition probabilities of the isomeric states are compared to shell-model predictions. Latest shell-model calculations reproduce the experimental findings generally well and provide guidance to the interpretation of the new levels.

  13. Prevalence and Characteristics of Salmonella Serotypes Isolated from Fresh Produce Marketed in the United States.

    PubMed

    Reddy, Shanker P; Wang, Hua; Adams, Jennifer K; Feng, Peter C H

    2016-01-01

    Salmonella continues to rank as one of the most costly foodborne pathogens, and more illnesses are now associated with the consumption of fresh produce. The U.S. Department of Agriculture Microbiological Data Program (MDP) sampled select commodities of fresh fruit and vegetables and tested them for Salmonella, pathogenic Escherichia coli, and Listeria. The Salmonella strains isolated were further characterized by serotype, antimicrobial resistance, and pulsed-field gel electrophoresis profile. This article summarizes the Salmonella data collected by the MDP between 2002 and 2012. The results show that the rates of Salmonella prevalence ranged from absent to 0.34% in cilantro. A total of 152 isolates consisting of over 50 different serotypes were isolated from the various produce types, and the top five were Salmonella enterica serotype Cubana, S. enterica subspecies arizonae (subsp. IIIa) and diarizonae (subsp. IIIb), and S. enterica serotypes Newport, Javiana, and Infantis. Among these, Salmonella serotypes Newport and Javiana are also listed among the top five Salmonella serotypes that caused most foodborne outbreaks. Other serotypes that are frequent causes of infection, such as S. enterica serotypes Typhimurium and Enteritidis, were also found in fresh produce but were not prevalent. About 25% of the MDP samples were imported produce, including 65% of green onions, 44% of tomatoes, 42% of hot peppers, and 41% of cantaloupes. However, imported produce did not show higher numbers of Salmonella-positive samples, and in some products, like cilantro, all of the Salmonella isolates were from domestic samples. About 6.5% of the Salmonella isolates were resistant to the antimicrobial compounds tested, but no single commodity or serotype was found to be the most common carrier of resistant strains or of resistance. The pulsed-field gel electrophoresis profiles of the produce isolates showed similarities with Salmonella isolates from meat samples and from outbreaks, but

  14. Potential for Producing Hydrogen from Key Renewable Resources in the United States

    SciTech Connect

    Milbrandt, A.; Mann, M.

    2006-02-01

    This study estimates the potential for hydrogen production from key renewable resources (onshore wind, solar photovoltaic, and biomass) by county in the United States. It includes maps that allow the reader to easily visualize the results.

  15. Ultrafast Laser System for Producing on-Demand Single-and Multi-Photon Quantum States

    DTIC Science & Technology

    2015-09-20

    quantum communication and computation technology; we have made significant progress toward that goal under this DURIP grant. In order to efficiently...photon quantum states The views, opinions and/or findings contained in this report are those of the author(s) and should not contrued as an official...U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 single-photon source, multiplexing, quantum state synthesis REPORT

  16. Isolation and selection of new biosurfactant producing bacteria from degraded palm kernel cake under liquid state fermentation.

    PubMed

    Jamal, Parveen; Mir, Shajrat; Alam, Md Zahangir; Wan Nawawi, Wan M Fazli

    2014-01-01

    Biosurfactants are surface-active compounds produced by different microorganisms. The aim of this study was to introduce palm kernel cake (PKC) as a novel substrate for biosurfactant production using a potent bacterial strain under liquid state fermentation. This study was primarily based on the isolation and identification of biosurfactant-producing bacteria that could utilize palm kernel cake as a new major substrate. Potential bacterial strains were isolated from degraded PKC and screened for biosurfactant production with the help of the drop collapse assay and by analyzing the surface tension activity. From the screened isolates, a new strain, SM03, showed the best and most consistent results, and was therefore selected as the most potent biosurfactant-producing bacterial strain. The new strain was identified as Providencia alcalifaciens SM03 using the Gen III MicroPlate Biolog Microbial Identification System. The yield of the produced biosurfactant was 8.3 g/L.

  17. United States Producing and Nonproducing Crude Oil and Natural Gas Reserves From 1985 Through 2004

    EIA Publications

    2006-01-01

    This report discusses the regional and temporal trends in producing and nonproducing crude oil and natural gas reserves using the Energy Information Administration's (EIA) categorization of reserves. The report first focuses on EIA's collection and reporting of crude oil and natural gas reserves data, followed by a discussion of the natural gas reserve trends, and then the crude oil reserve trends.

  18. BIRTH MALFORMATIONS AND OTHER ADVERSE PERINATAL OUTCOMES IN FOUR U.S. WHEAT PRODUCING STATES: RESPONSE

    EPA Science Inventory

    Chlorophenoxy herbicides are widely used in the U.S. and Western Europe for broadleaf weed control in grain farming and park maintenance. Most of the spring and durum wheat produced in the U.S. is grown in Minnesota, Montana, North Dakota, and South Dakota, with over 85% of the a...

  19. MALFORMATIONS AND OTHER ADVERSE PERINATAL OUTCOMES IN FOUR U.S. WHEAT-PRODUCING STATES

    EPA Science Inventory

    ABSTRACT
    Chlorophenoxy herbicides are widely used in the U.S. and Western Europe in
    grain agriculture and for weed control. Most of the spring and durum wheat
    produced in the U.S. is grown in Minnesota, Montana, North Dakota, and
    South Dakota, with over 85% of th...

  20. Michigan state upgrade to produce intense radioactive ion beams by fragmentation technique

    SciTech Connect

    Lubkin, G.B.

    1997-05-01

    This article describes the planned upgrading of accelerator facilities to produce intense radioactive ion beams, by a fragmentation technique, for experimental simulation of nucleosynthesis in novas and supernovas. (AIP) {ital 1997 American Institute of Physics.} {copyright} {ital 1997} {ital American Institute of Physics}

  1. MALFORMATIONS AND OTHER ADVERSE PERINATAL OUTCOMES IN FOUR U.S. WHEAT-PRODUCING STATES

    EPA Science Inventory

    ABSTRACT
    Chlorophenoxy herbicides are widely used in the U.S. and Western Europe in
    grain agriculture and for weed control. Most of the spring and durum wheat
    produced in the U.S. is grown in Minnesota, Montana, North Dakota, and
    South Dakota, with over 85% of th...

  2. BIRTH MALFORMATIONS AND OTHER ADVERSE PERINATAL OUTCOMES IN FOUR U.S. WHEAT PRODUCING STATES: RESPONSE

    EPA Science Inventory

    Chlorophenoxy herbicides are widely used in the U.S. and Western Europe for broadleaf weed control in grain farming and park maintenance. Most of the spring and durum wheat produced in the U.S. is grown in Minnesota, Montana, North Dakota, and South Dakota, with over 85% of the a...

  3. Current state of purification, isolation and analysis of bacteriocins produced by lactic acid bacteria.

    PubMed

    Kaškonienė, Vilma; Stankevičius, Mantas; Bimbiraitė-Survilienė, Kristina; Naujokaitytė, Gintarė; Šernienė, Loreta; Mulkytė, Kristina; Malakauskas, Mindaugas; Maruška, Audrius

    2017-02-01

    The scientific interest for the search of natural means of microbial inhibitors has not faded for several years. A search of natural antibiotics, so-called bacteriocins which are produced by lactic acid bacteria (LAB), gains a huge attention of the scientists in the last century, in order to reduce the usage of synthetic food additives. Pure bacteriocins with wide spectra of antibacterial activity are promising among the natural biopreservatives. The usage of bacteriocin(s) producing LAB as starter culture for the fermentation of some food products, in order to increase their shelf-life, when synthetic preservatives are not allowable, is also possible. There are a lot of studies focusing on the isolation of new bacteriocins from traditional fermented food, dairy products and other foods or sometimes even from unusual non-food matrices. Bacteriocins producing bacteria have been isolated from different sources with the different antibacterial activity against food-borne microorganisms. This review covers the classification of bacteriocins, diversity of sources of bacteriocin(s) producing LAB, antibacterial spectra of isolated bacteriocins and analytical methods for the bacteriocin purification and analysis within the last 15 years.

  4. Phenazine-producing fluorescent Pseudomonas spp.: Diversity and biogeography in central Washington state

    USDA-ARS?s Scientific Manuscript database

    Strains of the rhizosphere bacterium Pseudomonas fluorescens produce redox-active phenazine antibiotics that suppress a wide variety of soilborne plant pathogens. Our laboratory recently detected these bacteria a population levels up to 106 colony-forming units (cfu) per gram of root (fresh weight)...

  5. A comparative study of allowable pesticide residue levels on produce in the United States

    PubMed Central

    2012-01-01

    Background The U.S. imports a substantial and increasing portion of its fruits and vegetables. The U.S. Food and Drug Administration currently inspects less than one percent of import shipments. While countries exporting to the U.S. are expected to comply with U.S. tolerances, including allowable pesticide residue levels, there is a low rate of import inspections and few other incentives for compliance. Methods This analysis estimates the quantity of excess pesticide residue that could enter the U.S. if exporters followed originating country requirements but not U.S. pesticide tolerances, for the top 20 imported produce items based on quantities imported and U.S. consumption levels. Pesticide health effects data are also shown. Results The model estimates that for the identified items, 120 439 kg of pesticides in excess of U.S. tolerances could potentially be imported to the U.S., in cases where U.S. regulations are more protective than those of originating countries. This figure is in addition to residues allowed on domestic produce. In the modeling, the top produce item, market, and pesticide of concern were oranges, Chile, and Zeta-Cypermethrin. Pesticides in this review are associated with health effects on 13 body systems, and some are associated with carcinogenic effects. Conclusions There is a critical information gap regarding pesticide residues on produce imported to the U.S. Without a more thorough sampling program, it is not possible accurately to characterize risks introduced by produce importation. The scenario presented herein relies on assumptions, and should be considered illustrative. The analysis highlights the need for additional investigation and resources for monitoring, enforcement, and other interventions, to improve import food safety and reduce pesticide exposures in originating countries. PMID:22293037

  6. Metal-organic charge transfer can produce biradical states and is mediated by conical intersections

    PubMed Central

    Tishchenko, Oksana; Li, Ruifang; Truhlar, Donald G.

    2010-01-01

    The present paper illustrates key features of charge transfer between calcium atoms and prototype conjugated hydrocarbons (ethylene, benzene, and coronene) as elucidated by electronic structure calculations. One- and two-electron charge transfer is controlled by two sequential conical intersections. The two lowest electronic states that undergo a conical intersection have closed-shell and open-shell dominant configurations correlating with the 4s2 and 4s13d1 states of Ca, respectively. Unlike the neutral-ionic state crossing in, for example, hydrogen halides or alkali halides, the path from separated reactants to the conical intersection region is uphill and the charge-transferred state is a biradical. The lowest-energy adiabatic singlet state shows at least two minima along a single approach path of Ca to the π system: (i) a van der Waals complex with a doubly occupied highest molecular orbital, denoted , and a small negative charge on Ca and (ii) an open-shell singlet (biradical) at intermediate approach (Ca⋯C distance ≈2.5–2.7 Å) with molecular orbital structure ϕ1ϕ2, where ϕ2 is an orbital showing significant charge transfer form Ca to the π-system, leading to a one-electron multicentered bond. A third minimum (iii) at shorter distances along the same path corresponding to a closed-shell state with molecular orbital structure has also been found; however, it does not necessarily represent the ground state at a given Ca⋯C distance in all three systems. The topography of the lowest adiabatic singlet potential energy surface is due to the one- and two-electron bonding patterns in Ca-π complexes. PMID:21037111

  7. Automation from pictures: Producing real time code from a state transition diagram

    SciTech Connect

    Kozubal, A.J.

    1991-01-01

    The state transition diagram (STD) model has been helpful in the design of real time software, especially with the emergence of graphical computer aided software engineering (CASE) tools. Nevertheless, the translation of the STD to real time code has in the past been primarily a manual task. At Los Alamos we have automated this process. The designer constructs the STD using a CASE tool (Cadre Teamwork) using a special notation for events and actions. A translator converts the STD into an intermediate state notation language (SNL), and this SNL is compiled directly into C code (a state program). Execution of the state program is driven by external events, allowing multiple state programs to effectively share the resources of the host processor. Since the design and the code are tightly integrated through the CASE tool, the design and code never diverge, and we avoid design obsolescence. Furthermore, the CASE tool automates the production of formal technical documents from the graphic description encapsulated by the CASE tool. 10 refs., 3 figs.

  8. Towards producing ultracold CaNa+ molecular ions in the ground electronic state

    NASA Astrophysics Data System (ADS)

    Gacesa, Marko; Montgomery, John A.; Michels, Harvey H.; Côté, Robin

    2015-05-01

    We present a theoretical analysis of optical pathways for the formation of cold Ca(1S)Na+(1S) molecular ions, based on accurate potential energy curves and transition dipole moments calculated using effective-core-potential methods of quantum chemistry. In the proposed approach, starting from a mixture of trapped laser-cooled Ca+ ions immersed into an ultracold gas of Na atoms, the (NaCa)+ are photoassociated in the excited E1Σ+ electronic state, followed by spontaneous radiative charge transfer and emission through an intermediate state. We find the optimal formation pathway and report radiative charge-exchange cross sections and vibrational distributions of participating electronic states. This work is partially supported by ARO.

  9. Low-Btu coal gasification in the United States: company topical. [Brick producers

    SciTech Connect

    Boesch, L.P.; Hylton, B.G.; Bhatt, C.S.

    1983-07-01

    Hazelton and other brick producers have proved the reliability of the commercial size Wellman-Galusha gasifier. For this energy intensive business, gas cost is the major portion of the product cost. Costs required Webster/Hazelton to go back to the old, reliable alternative energy of low Btu gasification when the natural gas supply started to be curtailed and prices escalated. Although anthracite coal prices have skyrocketed from $34/ton (1979) to over $71.50/ton (1981) because of high demand (local as well as export) and rising labor costs, the delivered natural gas cost, which reached $3.90 to 4.20/million Btu in the Hazelton area during 1981, has allowed the producer gas from the gasifier at Webster Brick to remain competitive. The low Btu gas cost (at the escalated coal price) is estimated to be $4/million Btu. In addition to producing gas that is cost competitive with natural gas at the Webster Brick Hazelton plant, Webster has the security of knowing that its gas supply will be constant. Improvements in brick business and projected deregulation of the natural gas price may yield additional, attractive cost benefits to Webster Brick through the use of low Btu gas from these gasifiers. Also, use of hot raw gas (that requires no tar or sulfur removal) keeps the overall process efficiency high. 25 references, 47 figures, 14 tables.

  10. Subjective State, Blood Pressure, and Behavioral Control Changes Produced by an “Energy Shot”

    PubMed Central

    Stamates, Amy L.; Ossege, Julianne; Maloney, Sarah F.; Bardgett, Mark E.; Brown, Clifford J.

    2014-01-01

    Background: Energy drinks and energy shots are popular consumer beverages that are advertised to increase feelings of alertness. Typically, these products include high levels of caffeine, a mild psychostimulant drug. The scientific evidence demonstrating the specific benefits of energy products to users in terms of subjective state and objective performance is surprisingly lacking. Moreover, there are rising health concerns associated with the use of these products. Therefore, the purpose of this study was to investigate the acute effects of a popular energy shot (5-Hour Energy®) on subjective and objective measures that were assessed hourly for 6 hours following consumption. Methods: Participants (n=14) completed a three-session study where they received the energy shot, a placebo control, and no drink. Following dose administration, participants completed subjective Profile of Mood States ratings hourly for 6 hours. Participants also repeatedly completed a behavioral control task (the cued go/no-go task) and provided blood pressure and pulse rate readings at each hour. Results: Consumption of the energy shot did improve subjective state, as measured by increased ratings of vigor and decreased ratings of fatigue. However, the energy shot did not alter objective performance, which worsened over time. Importantly, the energy shot elevated both systolic and diastolic blood pressure. Conclusions: Consumption of one energy shot may only result in modest benefits to subjective state. Individuals with preexisting hypertension or other medical conditions should be cautious about using these new consumer products. PMID:25054080

  11. Solid-state NMR and ESR studies of activated carbons produced from pecan shells

    USDA-ARS?s Scientific Manuscript database

    Activated carbon from pecan shells has shown promise as an adsorbent in water treatment and sugar refining. However, the chemistry of the material is complex and not fully understood. We report here the application of solid state NMR and ESR to study the chemical structure, mobility, and pore volu...

  12. Orbitofrontal cortex neurofeedback produces lasting changes in contamination anxiety and resting-state connectivity

    PubMed Central

    Scheinost, D; Stoica, T; Saksa, J; Papademetris, X; Constable, R T; Pittenger, C; Hampson, M

    2013-01-01

    Anxiety is a core human emotion but can become pathologically dysregulated. We used functional magnetic resonance imaging (fMRI) neurofeedback (NF) to noninvasively alter patterns of brain connectivity, as measured by resting-state fMRI, and to reduce contamination anxiety. Activity of a region of the orbitofrontal cortex associated with contamination anxiety was measured in real time and provided to subjects with significant but subclinical anxiety as a NF signal, permitting them to learn to modulate the target brain region. NF altered network connectivity of brain regions involved in anxiety regulation: subjects exhibited reduced resting-state connectivity in limbic circuitry and increased connectivity in the dorsolateral prefrontal cortex. NF has been shown to alter brain connectivity in other contexts, but it has been unclear whether these changes persist; critically, we observed changes in connectivity several days after the completion of NF training, demonstrating that such training can lead to lasting modifications of brain functional architecture. Training also increased subjects' control over contamination anxiety several days after the completion of NF training. Changes in resting-state connectivity in the target orbitofrontal region correlated with these improvements in anxiety. Matched subjects undergoing a sham feedback control task showed neither a reorganization of resting-state functional connectivity nor an improvement in anxiety. These data suggest that NF can enable enhanced control over anxiety by persistently reorganizing relevant brain networks and thus support the potential of NF as a clinically useful therapy. PMID:23632454

  13. Subjective State, Blood Pressure, and Behavioral Control Changes Produced by an "Energy Shot"

    PubMed

    Marczinski, Cecile A; Stamates, Amy L; Ossege, Julianne; Maloney, Sarah F; Bardgett, Mark E; Brown, Clifford J

    2014-06-01

    Background: Energy drinks and energy shots are popular consumer beverages that are advertised to increase feelings of alertness. Typically, these products include high levels of caffeine, a mild psychostimulant drug. The scientific evidence demonstrating the specific benefits of energy products to users in terms of subjective state and objective performance is surprisingly lacking. Moreover, there are rising health concerns associated with the use of these products. Therefore, the purpose of this study was to investigate the acute effects of a popular energy shot (5-Hour Energy(®)) on subjective and objective measures that were assessed hourly for 6 hours following consumption. Methods: Participants (n=14) completed a three-session study where they received the energy shot, a placebo control, and no drink. Following dose administration, participants completed subjective Profile of Mood States ratings hourly for 6 hours. Participants also repeatedly completed a behavioral control task (the cued go/no-go task) and provided blood pressure and pulse rate readings at each hour. Results: Consumption of the energy shot did improve subjective state, as measured by increased ratings of vigor and decreased ratings of fatigue. However, the energy shot did not alter objective performance, which worsened over time. Importantly, the energy shot elevated both systolic and diastolic blood pressure. Conclusions: Consumption of one energy shot may only result in modest benefits to subjective state. Individuals with preexisting hypertension or other medical conditions should be cautious about using these new consumer products.

  14. Redox state and energy metabolism during liver regeneration: alterations produced by acute ethanol administration.

    PubMed

    Gutiérrez-Salinas, J; Miranda-Garduño, L; Trejo-Izquierdo, E; Díaz-Muñoz, M; Vidrio, S; Morales-González, J A; Hernández-Muñoz, R

    1999-12-01

    Ethanol metabolism can induce modifications in liver metabolic pathways that are tightly regulated through the availability of cellular energy and through the redox state. Since partial hepatectomy (PH)-induced liver proliferation requires an oversupply of energy for enhanced syntheses of DNA and proteins, the present study was aimed at evaluating the effect of acute ethanol administration on the PH-induced changes in cellular redox and energy potentials. Ethanol (5 g/kg body weight) was administered to control rats and to two-thirds hepatectomized rats. Quantitation of the liver content of lactate, pyruvate, beta-hydroxybutyrate, acetoacetate, and adenine nucleotides led us to estimate the cytosolic and mitochondrial redox potentials and energy parameters. Specific activities in the liver of alcohol-metabolizing enzymes also were measured in these animals. Liver regeneration had no effect on cellular energy availability, but induced a more reduced cytosolic redox state accompanied by an oxidized mitochondrial redox state during the first 48 hr of treatment; the redox state normalized thereafter. Administration of ethanol did not modify energy parameters in PH rats, but this hepatotoxin readily blocked the PH-induced changes in the cellular redox state. In addition, proliferating liver promoted decreases in the activity of alcohol dehydrogenase (ADH) and of cytochrome P4502E1 (CYP2E1); ethanol treatment prevented the PH-induced diminution of ADH activity. In summary, our data suggest that ethanol could minimize the PH-promoted metabolic adjustments mediated by redox reactions, probably leading to an ineffective preparatory event that culminates in compensatory liver growth after PH in the rat.

  15. Nuclear energy surfaces at high-spin in the A{approximately}180 mass region

    SciTech Connect

    Chasman, R.R.; Egido, J.L.; Robledo, L.M.

    1995-08-01

    We are studying nuclear energy surfaces at high spin, with an emphasis on very deformed shapes using two complementary methods: (1) the Strutinsky method for making surveys of mass regions and (2) Hartree-Fock calculations using a Gogny interaction to study specific nuclei that appear to be particularly interesting from the Strutinsky method calculations. The great advantage of the Strutinsky method is that one can study the energy surfaces of many nuclides ({approximately}300) with a single set of calculations. Although the Hartree-Fock calculations are quite time-consuming relative to the Strutinsky calculations, they determine the shape at a minimum without being limited to a few deformation modes. We completed a study of {sup 182}Os using both approaches. In our cranked Strutinsky calculations, which incorporate a necking mode deformation in addition to quadrupole and hexadecapole deformations, we found three well-separated, deep, strongly deformed minima. The first is characterized by nuclear shapes with axis ratios of 1.5:1; the second by axis ratios of 2.2:1 and the third by axis ratios of 2.9:1. We also studied this nuclide with the density-dependent Gogny interaction at I = 60 using the Hartree-Fock method and found minima characterized by shapes with axis ratios of 1.5:1 and 2.2:1. A comparison of the shapes at these minima, generated in the two calculations, shows that the necking mode of deformation is extremely useful for generating nuclear shapes at large deformation that minimize the energy. The Hartree-Fock calculations are being extended to larger deformations in order to further explore the energy surface in the region of the 2.9:1 minimum.

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

    PubMed

    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.

  17. Automated Tracking of Tornado-Producing Mesoscale Convective Systems in the United States

    NASA Astrophysics Data System (ADS)

    Kuo, K.; Hong, Y.; Clune, T. L.

    2011-12-01

    The great majority of Earth Science events are studied using "snap-shot" observations in time, mainly due to the scarcity of observations with dense temporal coverage and the lack of robust methods amenable to connecting the "snap shots". To enable the studies of these events in the four-dimensional (4D) spatiotemporal space and to demonstrate the utility of this capability, we have applied the neighbor enclosed area tracking (NEAT) method of Inatsu (2009) to three years of high-resolution (in both time and space) NEXRAD-derived and rain-gauge-corrected QE2 precipitation observations and GOES satellite Rapid Scan Operation imagery to track tornado-producing mesoscale convective systems (MCS's). We combine information from the databases of the Tornado History Project (which provides tornado occurrence and trajectory) and the NWS Watch/Warning Archive (which provides severe weather watch/warning locations) to obtain initial estimate of the time and location of a tornado-producing MCS. The NEAT algorithm is then applied to QE2 and GOES data, both forward and backward in time, to identify the entire system as one integral entity from its inception to its eventual dissipation in the 4D spatiotemporal space. For each system so identified, we extract its morphological/structural parameters, such as perimeter length, area, and orientation, from each of the snap shots in time. We also record physical parameters such as minimum and maximum precipitation rates. In addition, we perform areal integral on the precipitation rate field, which in turn enables time integral for the entire MCS throughout its lifecycle to obtain an estimate of the system's precipitation production. We can extend this proof-of-concept prototype to other precipitation producing severe weather events, such as blizzards. Furthermore, the spatiotemporal data collected may be used to discover other data, such as satellite remote sensing observations and model analyses/simulations, which can then be combined

  18. Carbapenemase-Producing Enterobacteriaceae in Swine Production in the United States: Impact and Opportunities.

    PubMed

    Johnson, Timothy J

    2017-02-01

    The discovery of carbapenemase-producing Enterobacteriaceae in U.S. swine production is troubling and underscores a tumultuous period where the outlook on the battle against superbugs is bleak. However, all is not lost. This commentary highlights both the good and the bad that can come from such findings, including those of a recent study published by Mollenkopf et al. (Antimicrob Agents Chemother 61:e012198-16, 2017, https://doi.org/doi:10.1128/AAC.01298-16). Copyright © 2017 American Society for Microbiology.

  19. Use of biomass for producing liquid fuel: Current state and innovations

    NASA Astrophysics Data System (ADS)

    Chernova, N. I.; Korobkova, T. P.; Kiseleva, S. V.

    2010-11-01

    Current matters relating to utilization of biomass for producing energy are discussed, including the most developed technologies of biopower engineering and innovative developments, as well as the possibilities of using nonfood raw materials as second-generation biofuel. It is shown that microalgae can be considered as prospective sources of different kinds of renewable biofuel, such as methane, biohydrogen, bioethanol, biobutanol, pyrolysis biofuel, biodiesel, and renewable diesel fuel, and can serve as an alternative to the traditional cultures used for power-generating purposes.

  20. Dynamics of atomic spin-orbit-state wave packets produced by short-pulse laser photodetachment

    NASA Astrophysics Data System (ADS)

    Law, S. M. K.; Gribakin, G. F.

    2016-11-01

    We analyze the experiment by Hultgren et al. [Phys. Rev. A 87, 031404 (2013), 10.1103/PhysRevA.87.031404] on orbital alignment and quantum beats in coherently excited atomic fine-structure manifolds produced by short-pulse laser photodetachment of C-,Si-,and Ge- negative ions, and derive a formula that describes the beats. Analysis of the experimental data enables us to extract the noncoherent background contribution for each species, and indicates the need for a full density-matrix treatment of the problem.

  1. Diffractively Produced Charm Final States in 800-GeV/c pp Collisions

    NASA Astrophysics Data System (ADS)

    Wang, M. H.; Berisso, M. C.; Christian, D. C.; Félix, J.; Gara, A.; Gottschalk, E.; Gutiérrez, G.; Hartouni, E. P.; Knapp, B. C.; Kreisler, M. N.; Lee, S.; Markianos, K.; Moreno, G.; Reyes, M. A.; Sosa, M.; Wehmann, A.; Wesson, D.

    2001-08-01

    We report the first observation of diffractively produced open charm in 800-GeV/c pp collisions of the type pp-->pD*X. We measure cross sections of σdiff(D*+) = (0.185+/-0.044+/-0.054) μb and σdiff(D*-) = (0.174+/-0.034+/-0.029) μb. Our measurements are based on 4.3×109 events recorded by FNAL E690 in the fixed-target run of 1991. We compare our results with previous fixed-target charm experiments.

  2. Diffractively Produced Charm Final States in 800-GeV / c pp Collisions

    SciTech Connect

    Wang, M. H. L. S.; Berisso, M. C.; Christian, D. C.; Felix, J.; Gara, A.; Gottschalk, E.; Gutierrez, G.; Hartouni, E. P.; Knapp, B. C.; Kreisler, M. N.

    2001-08-20

    We report the first observation of diffractively produced open charm in 800-GeV/c pp collisions of the type pp{yields}pD{sup *}X. We measure cross sections of {sigma}{sub diff}(D{sup *+})= (0.185{+-}0.044{+-}0.054) {mu}b and {sigma}{sub diff}(D{sup *-})= (0.174{+-}0.034{+-}0.029) {mu}b. Our measurements are based on 4.3 x 10{sup 9} events recorded by FNAL E690 in the fixed-target run of 1991. We compare our results with previous fixed-target charm experiments.

  3. Geographical and meteorological factors associated with isolation of Listeria species in New York State produce production and natural environments.

    PubMed

    Chapin, Travis K; Nightingale, Kendra K; Worobo, Randy W; Wiedmann, Martin; Strawn, Laura K

    2014-11-01

    Listeria species have been isolated from diverse environments, often at considerable prevalence, and are known to persist in food processing facilities. The presence of Listeria spp. has been suggested to be a marker for Listeria monocytogenes contamination. Therefore, a study was conducted to (i) determine the prevalence and diversity of Listeria spp. in produce production and natural environments and (ii) identify geographical and/or meteorological factors that affect the isolation of Listeria spp. in these environments. These data were also used to evaluate Listeria spp. as index organisms for L. monocytogenes in produce production environments. Environmental samples collected from produce production (n = 588) and natural (n = 734) environments in New York State were microbiologically analyzed to detect and isolate Listeria spp. The prevalence of Listeria spp. was approximately 33 and 34% for samples obtained from natural environments and produce production, respectively. Co-isolation of L. monocytogenes and at least one other species of Listeria in a given sample was recorded for 3 and 9% of samples from natural environments and produce production, respectively. Soil moisture and proximity to water and pastures were highly associated with isolation of Listeria spp. in produce production environments, while elevation, study site, and proximity to pastures were highly associated with isolation of Listeria spp. in natural environments, as determined by randomForest models. These data show that Listeria spp. were prevalent in both agricultural and nonagricultural environments and that geographical and meteorological factors associated with isolation of Listeria spp. were considerably different between the two environments.

  4. Correlations between protons produced in the decay of ^10C and ^6Be states.

    NASA Astrophysics Data System (ADS)

    Shane, R.; Mercurio, K. M.; Charity, R. J.; Elson, J. M.; Sobotka, L. G.; Famiano, M.; Wuosmaa, A.; Banu, A.; Fu, C.; Trache, L.; Tribble, R. E.; Mukhamedzhanov, A. M.

    2008-04-01

    This talk will present the 2-proton correlation data from recent secondary beam experiments using the MARS separator at TAMU. The experiment itself and the extracted decay paths for the previously known levels and a newly discovered level are described in a separate talk by K. Mercurio. The 2-proton relative-energy and relative-angle spectra for the ^10C state at E*=6.6 MeV contain correlations that can be reproduced by R-matrix or Fadeev calculations but not sequential or three-body calculations. In the same experiment, we also collected kinematically complete data on ^6Be ground-state decay. These data, as well as calculations from Grigorenko, will be presented in Jacobi ``T'' and ``Y'' coordinates.

  5. Quality Parameters and Chemical Analysis for Biodiesel Produced in the United States in 2011

    SciTech Connect

    Alleman, T. L.; Fouts, L.; Chupka, G.

    2013-03-01

    Samples of biodiesel (B100) from producers and terminals in 2011were tested for critical properties: free and total glycerin, flash point, cloud point, oxidation stability, cold soak filterability, and metals. Failure rates for cold soak filterability and oxidation stability were below 5%. One sample failed flash point due to excess methanol. One sample failed oxidation stability and metal content. Overall, 95% of the samples from this survey met biodiesel quality specification ASTM D6751. In 2007, a sampling of B100 from production facilities showed that nearly 90% met D6751. In samples meeting D6751, calcium was found above the method detection limit in nearly half the samples. Feedstock analysis revealed half the biodiesel was produced from soy and half was from mixed feedstocks. The saturated fatty acid methyl ester concentration of the B100 was compared to the saturated monoglyceride concentration as a percent of total monoglyceride. The real-world correlation of these properties was very good. The results of liquid chromatograph measurement of monoglycerides were compared to ASTM D6751. Agreement between the two methods was good, particularly for total monoglycerides and unsaturated monoglycerides. Because only very low levels of saturated monoglycerides measured, the two methods had more variability, but the correlation was still acceptable.

  6. Ion-Ion Reactions with Fixed-Charge Modified Proteins to Produce Ions in a Single, Very High Charge State

    PubMed Central

    Frey, Brian L.; Krusemark, Casey J.; Ledvina, Aaron R.; Coon, Joshua J.; Belshaw, Peter J.

    2008-01-01

    Electrospray ionization (ESI) of denatured proteins produces a mass spectrum with a broad distribution of multiply charged ions. Attaching fixed positive charges, specifically quaternary ammonium groups, to proteins at their carboxylic acid groups generates substantially higher charge states compared to the corresponding unmodified proteins in positive-mode ESI. Ion-ion reactions of these modified proteins with reagent anions leads to charge reduction by proton transfer. These proton transfer reactions cannot remove charge from the quaternary ammonium groups, which do not have a proton to transfer to the anion. Thus, one might expect charge reduction to stop at a single charge state equal to the number of fixed charges on the modified protein. However, ion-ion reactions yield charge states lower than this number of fixed charges due to anion attachment (adduction) to the proteins. Charge reduction via ion-molecule reactions involving gas-phase bases also give adducts on the modified protein ions in low charge states. Such adducts are avoided by keeping the ions in charge states well above the number of fixed charges. In the present work protein ions were selectively “parked” within an ion trap mass spectrometer in a high charge state by mild radiofrequency excitation that dramatically slows their ion-ion reaction rate—a technique termed “ion parking”. The combination of ion parking with the fixed-charge modified proteins permits generation of a large population of ions in a single, very high charge state. PMID:19802328

  7. Ion-Ion Reactions with Fixed-Charge Modified Proteins to Produce Ions in a Single, Very High Charge State.

    PubMed

    Frey, Brian L; Krusemark, Casey J; Ledvina, Aaron R; Coon, Joshua J; Belshaw, Peter J; Smith, Lloyd M

    2008-10-01

    Electrospray ionization (ESI) of denatured proteins produces a mass spectrum with a broad distribution of multiply charged ions. Attaching fixed positive charges, specifically quaternary ammonium groups, to proteins at their carboxylic acid groups generates substantially higher charge states compared to the corresponding unmodified proteins in positive-mode ESI. Ion-ion reactions of these modified proteins with reagent anions leads to charge reduction by proton transfer. These proton transfer reactions cannot remove charge from the quaternary ammonium groups, which do not have a proton to transfer to the anion. Thus, one might expect charge reduction to stop at a single charge state equal to the number of fixed charges on the modified protein. However, ion-ion reactions yield charge states lower than this number of fixed charges due to anion attachment (adduction) to the proteins. Charge reduction via ion-molecule reactions involving gas-phase bases also give adducts on the modified protein ions in low charge states. Such adducts are avoided by keeping the ions in charge states well above the number of fixed charges. In the present work protein ions were selectively "parked" within an ion trap mass spectrometer in a high charge state by mild radiofrequency excitation that dramatically slows their ion-ion reaction rate-a technique termed "ion parking". The combination of ion parking with the fixed-charge modified proteins permits generation of a large population of ions in a single, very high charge state.

  8. Symmetry-adapted perturbation theory utilizing density functional description of monomers for high-spin open-shell complexes.

    PubMed

    Zuchowski, Piotr S; Podeszwa, Rafał; Moszyński, Robert; Jeziorski, Bogumił; Szalewicz, Krzysztof

    2008-08-28

    We present an implementation of symmetry-adapted perturbation theory (SAPT) to interactions of high-spin open-shell monomers forming high-spin dimers. The monomer spin-orbitals used in the expressions for the electrostatic and exchange contributions to the interaction energy are obtained from density functional theory using a spin-restricted formulation of the open-shell Kohn-Sham (ROKS) method. The dispersion and induction energies are expressed through the density-density response functions predicted by the time-dependent ROKS theory. The method was applied to several systems: NH...He, CN...Ne, H2O...HO2, and NH...NH. It provides accuracy comparable to that of the best previously available methods such as the open-shell coupled-cluster method with single, double, and noniterative triple excitations, RCCSD(T), with a significantly reduced computational cost.

  9. A point mutation in domain 4-segment 6 of the skeletal muscle sodium channel produces an atypical inactivation state.

    PubMed Central

    O'Reilly, J P; Wang, S Y; Wang, G K

    2000-01-01

    We compared wild-type rat skeletal muscle NaChs (micro1) and a mutant NaCh (Y1586K) that has a single amino acid substitution, lysine (K) for tyrosine (Y), at position 1586 in the S6 transmembrane segment of domain 4. In Y1586K, macroscopic current decay is faster, the V(1/2) of the activation curve is shifted in the depolarized direction, and the fast-inactivation curve is less steep compared with mu1. After an 8-ms depolarization pulse, Y1586K recovers from inactivation much more slowly than mu1. The recovery is double exponential, suggesting recovery from two inactivation states. Varying the depolarization protocols isolates entry into an additional, "atypical" inactivation state in Y1586K that is distinct from typical fast or slow inactivation. Substitution of positively charged arginine (R) at Y1586 produces an inactivation phenotype similar to that of Y1586K. Substitution by negatively charged aspartic acid (D) or uncharged alanine (A) at Y1586 produces an inactivation phenotype similar to mu1. Our results suggest that the positive charge of lysine (K) produces the atypical inactivation state in Y1586K. We propose that a conformational change during depolarization alters the relative position of the 1586K residue in the D4-S6 segment and that atypical inactivation in Y1586K occurs via an electrostatic interaction in or near the inner pore region. PMID:10653790

  10. Feasibility of Producing and Using Biomass-Based Diesel and Jet Fuel in the United States

    SciTech Connect

    Milbrandt, A.; Kinchin, C.; McCormick, R.

    2013-12-01

    The study summarizes the best available public data on the production, capacity, cost, market demand, and feedstock availability for the production of biomass-based diesel and jet fuel. It includes an overview of the current conversion processes and current state-of-development for the production of biomass-based jet and diesel fuel, as well as the key companies pursuing this effort. Thediscussion analyzes all this information in the context of meeting the RFS mandate, highlights uncertainties for the future industry development, and key business opportunities.

  11. Cross Section of Isomeric States Produced in Photo-Neutron Reactions

    NASA Astrophysics Data System (ADS)

    Oprea, C.; Oprea, A.; Mihul, A.

    In this work the cross sections of the isomeric states production in (γ,n) reactions and the corresponding isomeric ratios for some isotopes of Cd, Sn, Mo, Sm in the great dipole resonance region with Talys codes using a standard input including Hauser-Feshbach model were evaluated. For the isomeric ratio calculation two methods were proposed, by using the description of incident gamma flux and experimental isomeric ratio. The obtained results are compared with experimental data from nuclear reactions induced by photons obtained by bremsstrahlung.

  12. Metastable alloy materials produced by solid state reaction of compacted, mechanically deformed mixtures

    DOEpatents

    Atzmon, M.; Johnson, W.L.; Verhoeven, J.D.

    1987-02-03

    Bulk metastable, amorphous or fine crystalline alloy materials are produced by reacting cold-worked, mechanically deformed filamentary precursors such as metal powder mixtures or intercalated metal foils. Cold-working consolidates the metals, increases the interfacial area, lowers the free energy for reaction, and reduces at least one characteristic dimension of the metals. For example, the grains of powder or the sheets of foil are clad in a container to form a disc. The disc is cold-rolled between the nip of rollers to form a flattened disc. The grains are further elongated by further rolling to form a very thin sheet of a lamellar filamentary structure containing filaments having a thickness of less than 0.01 microns. Thus, diffusion distance and time for reaction are substantially reduced when the flattened foil is thermally treated in oven to form a composite sheet containing metastable material dispersed in unreacted polycrystalline material. 4 figs.

  13. Interface behavior of Al2O3/Ti joints produced by liquid state bonding.

    PubMed

    Lemus-Ruiz, J; Guevara-Laureano, A O; Zarate-Medina, J; Arellano-Lara, A; Ceja-Cárdenas, L

    2015-04-01

    In this work we study brazing of Al2O3 to Ti with biocompatibility properties, using a Au-foil as joining element. Al2O3 was produced by sintering of powder at 1550°C. Al2O3 samples were coated with a 2 and 4μm thick of Mo layer and then stacked with Ti. Al2O3-Mo/Au/Ti combinations were joined at 1100°C in vacuum. Successful joining of Mo-Al2O3 to Ti was observed. Interface shows the formation of a homogeneous diffusion zone. Mo diffused inside Au forming a concentration line. Ti3Au and TiAu phases were observed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. High-spin structures in 132Xe and 133Xe and evidence for isomers along the N =79 isotones

    NASA Astrophysics Data System (ADS)

    Vogt, A.; Siciliano, M.; Birkenbach, B.; Reiter, P.; Hadyńska-Klek, 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 132Xe and 133Xe are investigated after multinucleon-transfer (MNT) and fusion-evaporation reactions. Both nuclei are populated (i) in 136Xe+208Pb MNT reactions employing the high-resolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA, (ii) in the 136Xe+198Pt MNT reaction employing the GAMMASPHERE spectrometer in combination with the gas-detector array CHICO, and (iii) as an evaporation residue after a 130Te(α ,x n )134 -x nXe fusion-evaporation reaction employing the HORUS γ -ray array at the University of Cologne. The high-spin level schemes are considerably extended above the Jπ=(7-) and (10+) isomers in 132Xe and above the 11 /2- isomer in 133Xe. 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 (T1 /2≫1 μ s ) isomer in 133Xe 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.

  15. Mild Social Stress in Mice Produces Opioid-Mediated Analgesia in Visceral but Not Somatic Pain States.

    PubMed

    Pitcher, Mark H; Gonzalez-Cano, Rafael; Vincent, Kathleen; Lehmann, Michael; Cobos, Enrique J; Coderre, Terence J; Baeyens, José M; Cervero, Fernando

    2017-06-01

    Visceral pain has a greater emotional component than somatic pain. To determine if the stress-induced analgesic response is differentially expressed in visceral versus somatic pain states, we studied the effects of a mild social stressor in either acute visceral or somatic pain states in mice. We show that the presence of an unfamiliar conspecific mouse (stranger) in an adjacent cubicle of a standard transparent observation box produced elevated plasma corticosterone levels compared with mice tested alone, suggesting that the mere presence of a stranger is stressful. We then observed noxious visceral or somatic stimulation-induced nociceptive behavior in mice tested alone or in mildly stressful conditions (ie, beside an unfamiliar stranger). Compared with mice tested alone, the presence of a stranger produced a dramatic opioid-dependent reduction in pain behavior associated with visceral but not somatic pain. This social stress-induced reduction of visceral pain behavior relied on visual but not auditory/olfactory cues. These findings suggest that visceral pain states may provoke heightened responsiveness to mild stressors, an effect that could interfere with testing outcomes during simultaneous behavioral testing of multiple rodents. In mice, mild social stress due to the presence of an unfamiliar conspecific mouse reduces pain behavior associated with noxious visceral but not somatic stimulation, suggesting that stress responsiveness may be enhanced in visceral pain versus somatic pain states. Published by Elsevier Inc.

  16. Irrigation Is Significantly Associated with an Increased Prevalence of Listeria monocytogenes in Produce Production Environments in New York State.

    PubMed

    Weller, Daniel; Wiedmann, Martin; Strawn, Laura K

    2015-06-01

    Environmental (i.e., meteorological and landscape) factors and management practices can affect the prevalence of foodborne pathogens in produce production environments. This study was conducted to determine the prevalence of Listeria monocytogenes, Listeria species (including L. monocytogenes), Salmonella, and Shiga toxin-producing Escherichia coli (STEC) in produce production environments and to identify environmental factors and management practices associated with their isolation. Ten produce farms in New York State were sampled during a 6-week period in 2010, and 124 georeferenced samples (80 terrestrial, 33 water, and 11 fecal) were collected. L. monocytogenes, Listeria spp., Salmonella, and STEC were detected in 16, 44, 4, and 5% of terrestrial samples, 30, 58, 12, and 3% of water samples, and 45, 45, 27, and 9% of fecal samples, respectively. Environmental factors and management practices were evaluated for their association with terrestrial samples positive for L. monocytogenes or other Listeria species by univariate logistic regression; analysis was not conducted for Salmonella or STEC because the number of samples positive for these pathogens was low. Although univariate analysis identified associations between isolation of L. monocytogenes or Listeria spp. from terrestrial samples and various water-related factors (e.g., proximity to wetlands and precipitation), multivariate analysis revealed that only irrigation within 3 days of sample collection was significantly associated with isolation of L. monocytogenes (odds ratio = 39) and Listeria spp. (odds ratio = 5) from terrestrial samples. These findings suggest that intervention at the irrigation level may reduce the risk of produce contamination.

  17. Cortical brightness adaptation when darkness and brightness produce different dynamical states in the visual cortex

    PubMed Central

    Xing, Dajun; Yeh, Chun-I; Gordon, James; Shapley, Robert M.

    2014-01-01

    Darkness and brightness are very different perceptually. To understand the neural basis for the visual difference, we studied the dynamical states of populations of neurons in macaque primary visual cortex when a spatially uniform area (8° × 8°) of the visual field alternated between black and white. Darkness evoked sustained nerve-impulse spiking in primary visual cortex neurons, but bright stimuli evoked only a transient response. A peak in the local field potential (LFP) γ band (30–80 Hz) occurred during darkness; white-induced LFP fluctuations were of lower amplitude, peaking at 25 Hz. However, the sustained response to white in the evoked LFP was larger than for black. Together with the results on spiking, the LFP results imply that, throughout the stimulus period, bright fields evoked strong net sustained inhibition. Such cortical brightness adaptation can explain many perceptual phenomena: interocular speeding up of dark adaptation, tonic interocular suppression, and interocular masking. PMID:24398523

  18. Cortical brightness adaptation when darkness and brightness produce different dynamical states in the visual cortex.

    PubMed

    Xing, Dajun; Yeh, Chun-I; Gordon, James; Shapley, Robert M

    2014-01-21

    Darkness and brightness are very different perceptually. To understand the neural basis for the visual difference, we studied the dynamical states of populations of neurons in macaque primary visual cortex when a spatially uniform area (8° × 8°) of the visual field alternated between black and white. Darkness evoked sustained nerve-impulse spiking in primary visual cortex neurons, but bright stimuli evoked only a transient response. A peak in the local field potential (LFP) γ band (30-80 Hz) occurred during darkness; white-induced LFP fluctuations were of lower amplitude, peaking at 25 Hz. However, the sustained response to white in the evoked LFP was larger than for black. Together with the results on spiking, the LFP results imply that, throughout the stimulus period, bright fields evoked strong net sustained inhibition. Such cortical brightness adaptation can explain many perceptual phenomena: interocular speeding up of dark adaptation, tonic interocular suppression, and interocular masking.

  19. Search for narrow states produced in the reaction. pi. /sup -/p. -->. n + neutrals at 13 GeV/c

    SciTech Connect

    Chiang, I H; Johnson, R A; Kwan, B

    1980-01-01

    A double-arm lead-glass, lead-scintillator calorimeter system was used to search for narrow states, such as the eta/sub c/, produced in the exclusive reactions ..pi../sup -/p ..-->.. ..gamma gamma..n, ..pi../sup -/p ..-->.. ..pi../sup 0/..gamma..n, and ..pi../sup -/p ..-->.. ..pi../sup 0/..pi../sup 0/n at 13 GeV/c. We find a 90% c.1. upper limit sigma.BR < 260 pb for ..gamma gamma.. states with masses from 2.2 to 4.0 GeV/c/sup 2/. Corresponding limits on narrow ..pi../sup 0/..gamma.. and ..pi../sup 0/..pi../sup 0/ states are also given. 4 figures.

  20. Pre- and postextraction analyses of different charge state ion components produced in a laser ion source

    NASA Astrophysics Data System (ADS)

    Belloni, F.; Doria, D.; Lorusso, A.; Nassisi, V.; Krasa, J.

    2006-03-01

    Knowledge of the relative abundance and the energy distributions of various ion species produced in laser ablation plasma is essential both in the fundamental physics ground, to understand the thermalization and expansion dynamics of the plasma plume, and in the applied physics ground, to obtain an efficient and versatile ion source. We present measurements and analyses related to such aspects, both for plasma in free expansion and for the extracted ion bunch. In particular, we characterized the former by means of ion current measurements, employing appropriate Faraday cups and electrostatic spectrometers. With regard to the latter, we performed time-of-flight spectrometry and depth profiling of implanted substrates. The extracted bunch signal showed modulation on time of flight due to the presence of multiply charged ions; depth profiling by x-ray photoelectron spectroscopy also showed a maximum penetration range and a profile modulation compatible with a multienergetic beam. In these experiments we used ultraviolet excimer lasers, at irradiance values in the range of 0.1-10GW/cm2, to generate plasma from Cu and Al targets. The ion beams were extracted at voltages of tens of kV, dc.

  1. Metastable alloy materials produced by solid state reaction of compacted, mechanically deformed mixtures

    DOEpatents

    Atzmon, Michael; Johnson, William L.; Verhoeven, John D.

    1987-01-01

    Bulk metastable, amorphous or fine crystalline alloy materials are produced by reacting cold-worked, mechanically deformed filamentary precursors such as metal powder mixtures or intercalated metal foils. Cold-working consolidates the metals, increases the interfacial area, lowers the free energy for reaction, and reduces at least one characteristic dimension of the metals. For example, the grains (13) of powder or the sheets of foil are clad in a container (14) to form a disc (10). The disc (10) is cold-rolled between the nip (16) of rollers (18,20) to form a flattened disc (22). The grains (13) are further elongated by further rolling to form a very thin sheet (26) of a lamellar filamentary structure (FIG. 4) containing filaments having a thickness of less than 0.01 microns. Thus, diffusion distance and time for reaction are substantially reduced when the flattened foil (28) is thermally treated in oven (32) to form a composite sheet (33) containing metastable material (34) dispersed in unreacted polycrystalline material (36).

  2. Direct surface visualization of biofilms with high spin coordination clusters using Magnetic Resonance Imaging.

    PubMed

    Ranzinger, Florian; Herrling, Maria P; Lackner, Susanne; Grande, Vanessa W; Baniodeh, Amer; Powell, Annie K; Horn, Harald; Guthausen, Gisela

    2016-02-01

    Magnetic Resonance Imaging is a powerful tool for the investigation of a biofilms' physical structure determining mass transport behavior which is of major importance in biofilm research. The entire biofilm is imaged in situ non-invasively and non-destructively on a meso-scale. In this study, different contrast agents were applied to study the biofilm's properties with the focus on mass transport, which is achieved by varying the contrast agents with respect to their NMR and interaction properties. The spatio-temporal tracking of these cluster, molecular and particulate contrast agents in biofilms was achieved by T1-, T2-weighted and proton density images during short (20h) and long (14 d) term exposures. The best biofilm surface visualization was observed when applying a new high spin coordination cluster (Fe10Gd10) showing a high affinity to the biofilm's surface and a fast immobilization within minutes. Contrarily, the small molecular contrast agents show no immobilization and fully penetrated into the biofilm. A concentration equilibrium was observed which was confirmed in back diffusion experiments. Interactions between larger nanoparticulate contrast agents and the biofilm required hours to achieve immobilization. Thus, the penetration depth into the biofilm is predominantly size-dependent. Here, it is shown that biofilm surface interactions can be observed in situ and spatio-temporarily resolved. The reported methodology demonstrates a new means to explore mass transfer of various substances in biofilms. In biofilm research, the investigation of the biofilms' physical structure is of high relevance for the understanding of mass transport processes. However, commonly used imaging techniques for biofilm imaging such as CLSM or electron microscopy rarely visualize the real biofilm due to their invasiveness and destructiveness. Magnetic Resonance Imaging (MRI) represents the ideal tool to image the biofilm in situ, non-invasively and non-destructively with a

  3. Notes from the Field: Carbapenem-resistant Enterobacteriaceae Producing OXA-48-like Carbapenemases--United States, 2010-2015.

    PubMed

    Lyman, Meghan; Walters, Maroya; Lonsway, David; Rasheed, Kamile; Limbago, Brandi; Kallen, Alexander

    2015-12-04

    Carbapenem-resistant Enterobacteriaceae (CRE) are bacteria that are often resistant to most classes of antibiotics and cause health care-associated infections with high mortality rates. Among CRE, strains that carry plasmid-encoded carbapenemase enzymes that inactivate carbapenem antibiotics are of greatest public health concern because of their potential for rapid global dissemination, as evidenced by the increasing distribution of CRE that produce the Klebsiella pneumoniae carbapenemase and the New Delhi metallo-β-lactamase. Newly described resistance in Enterobacteriaceae, such as plasmid-mediated resistance to the last-line antimicrobial colistin, recently detected in China, and resistance to the newly approved antimicrobial, ceftazidime-avibactam, identified from a U.S. K. pneumoniae carbapenemase-producing isolate, highlight the continued urgency to delay spread of CRE. Monitoring the emergence of carbapenemases is crucial to limiting their spread; identification of patients carrying carbapenemase-producing CRE should result in the institution of transmission-based precautions and enhanced environmental cleaning to prevent transmission.* The OXA-48 carbapenemase was first identified in Enterobacteriaceae in Turkey in 2001, and OXA-48-like variants have subsequently been reported around the world. The first U.S. reports of OXA-48-like carbapenemases were published in 2013 and included retrospectively identified isolates from 2009 and two isolates collected in 2012 from patients in Virginia who had recently been hospitalized outside the United States. Although there are limited additional published reports from the United States, CDC continues to receive reprots of these organisms. This report describes patients identified as carrying CRE producing OXA-48-like carbapenemases in the United States during June 2010-August 2015.

  4. Producing and using genetic evaluations in the United States beef industry of today.

    PubMed

    Garrick, D J; Golden, B L

    2009-04-01

    The overall motivation for the development of an information system for beef cattle improvement is the belief that knowledge of breeding values and heterosis effects allows one to determine the consequences of alternative selection and mating options. With this information, livestock managers can easily shift populations in a desirable direction. The foundation principles for establishing a sound breeding program, including the prediction of animal performance for economically relevant traits and their incorporation into a single index of aggregate economic merit, have been well established over the last half century. Rather than this goal-based approach, the industry adopted a data-driven approach to the production of genetic evaluations that has been characterized by an overemphasis on the evaluation of productive traits, notably BW at various ages, with inadequate regard for other economically important traits, such as reproduction, animal health, and feed requirements. Production of evaluations is breed association centered, and this has delayed the introduction of national across-breed evaluations for all breeds and crosses of cattle. The computational aspects of producing evaluations are now migrating from land-grant universities to breed associations, but not yet to a single entity. The introduction of genomic information in the form of high-density SNP panels will introduce threats, challenges, and new opportunities for the production of evaluations, and represents the largest force to alter the structure of the beef improvement industry since the advent of AI. The use of evaluations has, until recently, stopped short of the provision of index merit as a basis for selection. Accordingly, the value propositions associated with annual improvement or the selection of alternative sires has not been well communicated. Technology, along with economic and other issues related to stakeholder acceptance, will collectively determine the future nature of the industry

  5. Cardiovascular responses to repetitive exposure to hyper- and hypogravity states produced by parabolic flight

    NASA Technical Reports Server (NTRS)

    Mukai, C. N.; Lathers, C. M.; Charles, J. B.; Bennett, B. S.

    1994-01-01

    Physiologic changes to repetitive hyper- and hypogravity stresses occurring during eight to ten parabolas on NASA's KC-135 aircraft were studied. Hemodynamic responses in 11 subjects in 4 different postures (supine, standing, sitting, and semisupine Space Shuttle launch position) were determined using noninvasive impedance cardiography. Five seconds of heart rate, cardiac index, thoracic fluid index, stroke index, ejection velocity index, and ventricular ejection time data were averaged during four different gravity (g) states: 1.3g (before parabola onset); 1.9g (parabola entry); 0g (parabola peak); and 1.7g (parabola exit) for each subject. The standing position was associated with the largest changes in the cardiovascular response to hypo- and hypergravity. The thoracic fluid index did not indicate a headward redistribution during transition from a simulated launch position to weightlessness. Analysis of the eight to ten parabolas revealed that, in general, values obtained at 1.8g differed from 1.6g, 0g differed from 1.6 and 1.3g, and 1.6g differed from 1.3g. The factors of gravity, thoracic fluid index, and cardiac index exhibited significant differences that were most likely to occur between parabola 1 versus parabolas 6, 7, and 8, and parabola 2 versus parabolas 4 through 8. Only the parameter of thoracic fluid index exhibited significance for parabolas 3 versus parabolas 6 and 7.

  6. Cardiovascular responses to repetitive exposure to hyper- and hypogravity states produced by parabolic flight

    NASA Technical Reports Server (NTRS)

    Mukai, C. N.; Lathers, C. M.; Charles, J. B.; Bennett, B. S.

    1994-01-01

    Physiologic changes to repetitive hyper- and hypogravity stresses occurring during eight to ten parabolas on NASA's KC-135 aircraft were studied. Hemodynamic responses in 11 subjects in 4 different postures (supine, standing, sitting, and semisupine Space Shuttle launch position) were determined using noninvasive impedance cardiography. Five seconds of heart rate, cardiac index, thoracic fluid index, stroke index, ejection velocity index, and ventricular ejection time data were averaged during four different gravity (g) states: 1.3g (before parabola onset); 1.9g (parabola entry); 0g (parabola peak); and 1.7g (parabola exit) for each subject. The standing position was associated with the largest changes in the cardiovascular response to hypo- and hypergravity. The thoracic fluid index did not indicate a headward redistribution during transition from a simulated launch position to weightlessness. Analysis of the eight to ten parabolas revealed that, in general, values obtained at 1.8g differed from 1.6g, 0g differed from 1.6 and 1.3g, and 1.6g differed from 1.3g. The factors of gravity, thoracic fluid index, and cardiac index exhibited significant differences that were most likely to occur between parabola 1 versus parabolas 6, 7, and 8, and parabola 2 versus parabolas 4 through 8. Only the parameter of thoracic fluid index exhibited significance for parabolas 3 versus parabolas 6 and 7.

  7. Secondary economic impact of acid deposition control legislation in six coal producing states: Final report

    SciTech Connect

    Scott, M.J.; Guthrie, S.J.

    1988-12-01

    Among the difficult policy questions on the US environmental agenda is what to do about emissions to the earth's atmosphere of pollutants that may result in ''acid rain''. The Congress has considered several pieces of legislation spelling out potential approaches to the problem and setting goals for emission reduction, mostly emphasizing the control of oxides of sulfur and nitrogen. Significant policy concern is the dollar costs to the nation's economy of achieving the intended effects of the legislation and the potential impacts on economic activity---in particular, losses of both coal mining and secondary service sector employment in states and regions dependent on the mining of high sulfur coal. There are several direct economic effects of regulations such as the acid rain control legislation. One of the more obvious effects was the switching from high sulfur coal to low sulfur coal. This would result in increases in employment and coal business procurements in low sulfur coal mining regions, but also would result in lower employment and lower coal business procurements in high sulfur coal mining areas. The potential negative effects are the immediate policy concern and are the focus of this report. 15 refs., 1 fig., 17 tabs.

  8. Reverse micellar extraction of fungal glucoamylase produced in solid-state fermentation culture.

    PubMed

    Paraj, Aliakbar; Khanahmadi, Morteza; Karimi, Keikhosro; Taherzadeh, Mohammad J

    2014-12-28

    Partial purification of glucoamylase from solid-state fermentation culture was, firstly, investigated by reverse micellar extraction (RME). To avoid back extraction problems, the glucoamylase was kept in the original aqueous phase, while the other undesired proteins/ enzymes were moved to the reverse micellar organic phase. The individual and interaction effects of main factors (i.e., pH and NaCl concentration in the aqueous phase, and concentration of sodium bis-2-ethyl-hexyl-sulfosuccinate (AOT) in the organic phase) were studied using response surface methodology. The optimum conditions for the maximum recovery of the enzyme were pH 2.75, 100 mM NaCl, and 200 mM AOT. Furthermore, the optimum organic to aqueous volume ratio (Vorg/Vaq) and appropriate number of sequential extraction stages were 2 and 3, respectively. Finally, 60% of the undesired enzymes including proteases and xylanases were removed from the aqueous phase, while 140% of glucoamylase activity was recovered in the aqueous phase and the purification factor of glucoamylase was found to be 3.0-fold.

  9. Hydrothermal liquefaction of microalgae to produce biofuels: state of the art and future prospects

    NASA Astrophysics Data System (ADS)

    Vlaskin, M. S.; Chernova, N. I.; Kiseleva, S. V.; Popel', O. S.; Zhuk, A. Z.

    2017-09-01

    The article presents a review of the state of the art and lines of research on hydrothermal liquefaction (HTL) of microalgae (MA). The main advantages of this technology for production of biofuel are that it does not require predrying of the feedstock and ensures a relatively high product yield—the ratio of the end product weight to the feedstock weight—owing to the fact that all the microalgal components, viz., lipids, proteins, and carbohydrates, are converted into biofuel. MA hydrothermal liquefaction is considered to be a promising technology for conversion of biomass and is a subject of a series of research studies and, judging by the available publications, the scope of research in this field is expanding currently. However, many significant problems remain unsolved. In particular, an active searched is being conducted for suitable strains that will ensure not only a high lipid yield—necessary to convert microalgae into biodiesel—but also higher biomass productivity and a higher biofuel yield; the chemical reactions that occur during the hydrothermal treatment are being studied; and the effect of significant process variables, such as temperature, heating rate, holdup time at the maximum temperature, biomass concentration in the water suspension, biochemical and elemental compositions of the microalgae, use of catalysts, etc., on the liquefaction processes is being studied. One of the urgent tasks is also the reduction of the nitrogen content in the resulting biofuel. Studies aimed at the development of a continuous process and rational heat-processing plants for thermal microalgal conversion are being conducted to increase the energy efficiency of the HTL process, in particular, to provide the heat recovery and separation of the end product.

  10. Validation of a Previously Developed Geospatial Model That Predicts the Prevalence of Listeria monocytogenes in New York State Produce Fields

    PubMed Central

    Weller, Daniel; Shiwakoti, Suvash; Bergholz, Peter; Grohn, Yrjo; Wiedmann, Martin

    2015-01-01

    Technological advancements, particularly in the field of geographic information systems (GIS), have made it possible to predict the likelihood of foodborne pathogen contamination in produce production environments using geospatial models. Yet, few studies have examined the validity and robustness of such models. This study was performed to test and refine the rules associated with a previously developed geospatial model that predicts the prevalence of Listeria monocytogenes in produce farms in New York State (NYS). Produce fields for each of four enrolled produce farms were categorized into areas of high or low predicted L. monocytogenes prevalence using rules based on a field's available water storage (AWS) and its proximity to water, impervious cover, and pastures. Drag swabs (n = 1,056) were collected from plots assigned to each risk category. Logistic regression, which tested the ability of each rule to accurately predict the prevalence of L. monocytogenes, validated the rules based on water and pasture. Samples collected near water (odds ratio [OR], 3.0) and pasture (OR, 2.9) showed a significantly increased likelihood of L. monocytogenes isolation compared to that for samples collected far from water and pasture. Generalized linear mixed models identified additional land cover factors associated with an increased likelihood of L. monocytogenes isolation, such as proximity to wetlands. These findings validated a subset of previously developed rules that predict L. monocytogenes prevalence in produce production environments. This suggests that GIS and geospatial models can be used to accurately predict L. monocytogenes prevalence on farms and can be used prospectively to minimize the risk of preharvest contamination of produce. PMID:26590280

  11. Validation of a Previously Developed Geospatial Model That Predicts the Prevalence of Listeria monocytogenes in New York State Produce Fields.

    PubMed

    Weller, Daniel; Shiwakoti, Suvash; Bergholz, Peter; Grohn, Yrjo; Wiedmann, Martin; Strawn, Laura K

    2015-11-20

    Technological advancements, particularly in the field of geographic information systems (GIS), have made it possible to predict the likelihood of foodborne pathogen contamination in produce production environments using geospatial models. Yet, few studies have examined the validity and robustness of such models. This study was performed to test and refine the rules associated with a previously developed geospatial model that predicts the prevalence of Listeria monocytogenes in produce farms in New York State (NYS). Produce fields for each of four enrolled produce farms were categorized into areas of high or low predicted L. monocytogenes prevalence using rules based on a field's available water storage (AWS) and its proximity to water, impervious cover, and pastures. Drag swabs (n = 1,056) were collected from plots assigned to each risk category. Logistic regression, which tested the ability of each rule to accurately predict the prevalence of L. monocytogenes, validated the rules based on water and pasture. Samples collected near water (odds ratio [OR], 3.0) and pasture (OR, 2.9) showed a significantly increased likelihood of L. monocytogenes isolation compared to that for samples collected far from water and pasture. Generalized linear mixed models identified additional land cover factors associated with an increased likelihood of L. monocytogenes isolation, such as proximity to wetlands. These findings validated a subset of previously developed rules that predict L. monocytogenes prevalence in produce production environments. This suggests that GIS and geospatial models can be used to accurately predict L. monocytogenes prevalence on farms and can be used prospectively to minimize the risk of preharvest contamination of produce.

  12. Virtual free ion magnetism and the absence of Jahn-Teller distortion in a linear two-coordinate complex of high-spin iron(II).

    PubMed

    Reiff, William M; LaPointe, Anne M; Witten, Edward H

    2004-08-25

    Mössbauer spectroscopy and dc magnetization measurements have been used to characterize the low temperature magnetism of a rigorously linear, two-coordinate complex of high-spin Fe(II), Fe[(C(Si(CH3)3]2 (1). The local C-Fe-C chromophore of 1 exhibits novel slow, single-ion paramagnetic relaxation and fully resolved magnetic hyperfine splitting of its zero field Mössbauer spectrum over the range approximately 100 to approximately 50K. The hyperfine field at 4.2 K is 152 T! This is the largest magnetic hyperfine field observed for iron to date regardless of spin, oxidation state, or coordination environment. This observation is attributable to the large unquenched orbital angular momentum corresponding to the degenerate ground (dxy, dx2-y2) orbital pair of 1 in local Dinfinityh symmetry. Maintenance of the ground-state degeneracy is required by the Jahn-Teller theorem leading to the unprecedented result that the magnitude of the magnetic moment of 1's 5Deltag ground state is essentially that of the parent free ion (5D4) ground term.

  13. Random-orientation high-spin electron spin resonance spectroscopy and comprehensive spectral analyses of the quintet dicarbene and dinitrene with meta-topological linkers: origins of peculiar line-broadening in fine-structure ESR spectra in organic rigid glasses.

    PubMed

    Koto, Teruaki; Sato, Kazunobu; Shiomi, Daisuke; Toyota, Kazuo; Itoh, Koichi; Wasserman, Edel; Takui, Takeji

    2009-08-27

    In high-spin chemistry, random-orientation fine-structure (FS) electron spin resonance (ESR) spectroscopy entertains advantages as the most facile and convenient method to identify high-spin systems, as frequently reported in the literature. Random-orientation ESR spectroscopy applicable to organic high-spin entities can date back to the Wasserman and co-workers' attempt on the first spin-quintet dicarbene, m-phenylenebis(phenylmethlene) (m-PBPM), in the 2-MTHF glass in 1963 and 1967, following their successful work on randomly oriented triplet-state ESR spectroscopy. The FS ESR spectrum of m-PBPM in the 2-MTHF glass, however, has never fully been analyzed due to a peculiar line-broadening appearing at many canonical peaks. Organic high-spin spectra from most quintet dinitrenes also suffer from similar phenomena. Seemingly intrinsic line-diffusing or -broadening phenomena adversely affect the reliable determination of FS parameters for organic high-spin entities in rigid glasses. In high-spin chemistry, the line-broadening has been an obstacle that masks key FS transitions in many cases. Thus, both the origin of the broadening and the comprehensive spectral analysis have been a long-standing issue. In this report, we examine the origin of the line-broadening appearing in the FS ESR spectra, illustrated by a comprehensive spectral analysis for m-PBPM in the quintet ground state and the first-documented quintet-state dinitrene, m-phenylenebis(nitrene) (m-PBN) in the 2-MTHF glass. A complete analysis of the random-orientation FS spectra from m-PBPM diluted in the benzophenone crystal has shown that the g-anisotropy of m-PBPM is not prominent. Also the higher-order FS terms such as S(i)(2)S(j)(2) group-theoretically allowed for S = 2 are not necessary in spite of the argument for a hydrocarbon-based tetraradical (S = 2) in the ground state. Our new approach to the line-broadening analysis invokes both exact analytical solutions for the resonance fields of canonical

  14. Developing County-level Water Footprints of Biofuel Produced from Switchgrass and Miscanthus x Giganteus in the United States

    SciTech Connect

    Wu, May M.; Chiu, Yi-Wen

    2014-09-30

    Perennial grass has been proposed as a potential candidate for producing cellulosic biofuel because of its promising productivity and benefits to water quality, and because it is a non-food feedstock. While extensive research focuses on selecting and developing species and conversion technologies, the impact of grass-based biofuel production on water resources remains less clear. As feedstock growth requires water and the type of water consumed may vary considerably from region to region, water use must be characterized with spatial resolution and on a fuel production basis. This report summarizes a study that assesses the impact of biofuel production on water resource use and water quality at county, state, and regional scales by developing a water footprint of biofuel produced from switchgrass and Miscanthus × giganteus via biochemical conversion.

  15. Spin density distribution of an organic high-spin molecule, biphenyl-3,3‧-bis(phenylmethylene), as studied by 1H-ENDOR and a UHF Hubbard calculation

    NASA Astrophysics Data System (ADS)

    Okamoto, Masayuki; Teki, Yoshio; Takui, Takeji; Kinoshita, Takamasa; Itoh, Koichi

    1990-10-01

    The π-spin density distribution in the first-excited triplet state of biphenyl-3,3'-bis(phenylmethylene) has been determined by single-crystal 1H-ENDOR. This organic high-spin molecule is unusual in that it violates the well-established spin prediction based on a simple MO theory plus Hund's rule. This unique spin alignment has been clarified as being due to spin correlation in view of the spin distribution observed as well as calculated using a UHF generalized Hubbard model.

  16. Accuracy of the FAMACHA system for on-farm use by sheep and goat producers in the southeastern United States.

    PubMed

    Burke, J M; Kaplan, R M; Miller, J E; Terrill, T H; Getz, W R; Mobini, S; Valencia, E; Williams, M J; Williamson, L H; Vatta, A F

    2007-06-20

    FAMACHA is a practical on-farm system designed to provide small ruminant producers a tool for improving their management of Haemonchus contortus infections. Although this system has become very popular and widely accepted by small ruminant producers in many regions of the southern United States, there is very limited data reported on the effectiveness of the FAMACHA system when performed by farmers. The objective of this study was to evaluate the accuracy of the FAMACHA system for on-farm use by small ruminant producers during the summer season. Small ruminant producers from Georgia, Louisiana, Florida, and Puerto Rico were trained to use the FAMACHA system by veterinarians and scientists experienced with this method. FAMACHA scores were assigned at least every 2 weeks by producers to weaned and mature sheep (n=552) and goats (n=676) of various breeds and ages between April and September 2004. At intervals that varied among farms from 2 to 8 weeks, researchers determined body condition scores (BCS; 1=thin and 5=fat) and collected blood and feces from a group of animals selected randomly to determine packed cell volume (PCV) and fecal egg counts (FEC). Two separate anemia thresholds were evaluated; these were defined by either FAMACHA score (>or=3 versus >or=4) or PCV (or=3 were considered anemic and PCV cutoff was or=3 were considered anemic and PCV cutoff was

  17. Experimental and theoretical investigation of the vibrational band structure of the 1 u5Π -1 g5Π high-spin system of C2

    NASA Astrophysics Data System (ADS)

    Bornhauser, P.; Visser, B.; Beck, M.; Knopp, G.; van Bokhoven, J. A.; Marquardt, R.; Radi, P. P.

    2017-03-01

    Vibrational levels of the recently observed high-spin transition (1 u5Π -1 g5Π ) of dicarbon [P. Bornhauser et al., J. Chem. Phys. 142, 094313 (2015)] are explored by applying non-linear double-resonant four-wave mixing and laser-induced fluorescence methods. The deperturbation of the d g3Π , υ = 8 and 1 g5Π , υ = 3 states results in accurate molecular constants for the υ = 3 "dark" quintet state. In addition, the spin-orbit interaction constant is determined and parameters for the upper Swan level d g3Π , υ = 8 are improved. The first excited vibrational state of 1 u5Π is observed by performing perturbation-assisted intersystem crossing via "gateway" states in the d g3Π , υ = 6 ˜1 g5Π ,υ = 0 system. The rotationally resolved spectra yield 11 transitions to 1 u5Π , υ = 1 that include four spin-substates. Data reduction results in accurate molecular constants of this vibrational level in the shallow potential energy surface of this state. Finally, υ = 1 and 2 of the lower quintet state (1 g5Π ) are measured by performing perturbation-assisted double-resonant excitation to the 1 u5Π , υ = 0 state and observing dispersed fluorescence. The obtained molecular constants are compared with high level ab initio computations at the multi-reference configuration interaction (MRCI) level of theory by using a large correlation consistent basis set or, alternatively, by applying the computationally less demanding method of explicitly correlated multi-reference configuration interaction (MRCI-F12). The spectroscopic accuracy of both methods is evaluated by comparison with the experimental findings.

  18. Highly spin-polarized materials and devices for spintronics(∗).

    PubMed

    Inomata, Koichiro; Ikeda, Naomichi; Tezuka, Nobuki; Goto, Ryogo; Sugimoto, Satoshi; Wojcik, Marek; Jedryka, Eva

    2008-01-01

    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 - x Fe x Al (CCFA(x)) and Co2FeSi1 - x Al x (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

  19. Successive membrane separation processes simplify concentration of lipases produced by Aspergillus niger by solid-state fermentation.

    PubMed

    Reinehr, Christian Oliveira; Treichel, Helen; Tres, Marcus Vinicius; Steffens, Juliana; Brião, Vandré Barbosa; Colla, Luciane Maria

    2017-02-25

    In this study, we developed a simplified method for producing, separating, and concentrating lipases derived from solid-state fermentation of agro-industrial residues by filamentous fungi. First, we used Aspergillus niger to produce lipases with hydrolytic activity. We analyzed the separation and concentration of enzymes using membrane separation processes. The sequential use of microfiltration and ultrafiltration processes made it possible to obtain concentrates with enzymatic activities much higher than those in the initial extract. The permeate flux was higher than 60 L/m(2) h during microfiltration using 20- and 0.45-µm membranes and during ultrafiltration using 100- and 50-kDa membranes, where fouling was reversible during the filtration steps, thereby indicating that the fouling may be removed by cleaning processes. These results demonstrate the feasibility of lipase production using A. niger by solid-state fermentation of agro-industrial residues, followed by successive tangential filtration with membranes, which simplify the separation and concentration steps that are typically required in downstream processes.

  20. Influence of the Nitrogen Donors on Non-Heme Iron Models of Superoxide Reductase: High-Spin FeIII-OOR Complexes

    PubMed Central

    Namuswe, Frances; Hayashi, Takahiro; Jiang, Yunbo; Kasper, Gary D.; Narducci Sarjeant, Amy A.; Moënne-Loccoz, Pierre; Goldberg, David P.

    2010-01-01

    A new 5-coordinate, (N4S(thiolate))FeII complex, containing tertiary amine donors, [FeII(Me4[15]aneN4)(SPh)]BPh4 (2), was synthesized and structurally characterized as a model of the reduced active site of superoxide reductase (SOR). Reaction of 2 with tert-butyl hydroperoxide (tBuOOH) at -78 °C led to the generation of the alkylperoxo-iron(III) complex [FeIII(Me4[15]aneN4)(SPh)(OOtBu)]+ (2a). The non-thiolate-ligated complex, [FeII(Me4[15]aneN4)-(OTf)2] (3), was also reacted with tBuOOH, and yielded the corresponding alkylperoxo complex [FeIII(Me4[15]aneN4)(OTf)(OOtBu)]+ (3a) at the elevated temperature of -23 °C. These species were characterized by low-temperature UV-vis, EPR, and resonance Raman spectroscopies. Complexes 2a and 3a exhibit distinctly different spectroscopic signatures than the analogous alkylperoxo complexes [FeIII([15]aneN4)(SAr)(OOR)]+, which contain secondary amine donors. Importantly, alkylation at nitrogen leads to a change from low-spin (S = ½) to high -spin (S = 5/2) of the iron(III) center. The resonance Raman data reveal that this change in spin-state has a large effect on the ν(Fe-O) and ν(O-O) vibrations, and a comparison between 2a and the non-thiolate-ligated complex 3a shows that axial ligation has an additional significant impact on these vibrations. In addition, to our knowledge this study is the first in which the influence of a ligand trans to a peroxo moiety has been evaluated for a structurally equivalent pair of high-spin/low-spin peroxo-iron(III) complexes. The implications of spin state and thiolate ligation are discussed with regard to the functioning of SOR. PMID:20000711

  1. Present state and perspective of downstream processing of biologically produced 1,3-propanediol and 2,3-butanediol.

    PubMed

    Xiu, Zhi-Long; Zeng, An-Ping

    2008-04-01

    1,3-Propanediol and 2,3-butanediol are two promising chemicals which have a wide range of applications and can be biologically produced. The separation of these diols from fermentation broth makes more than 50% of the total costs in their microbial production. This review summarizes the present state of methods studied for the recovery and purification of biologically produced diols, with particular emphasis on 1,3-propoanediol. Previous studies on the separation of 1,3-propanediol primarily include evaporation, distillation, membrane filtration, pervaporation, ion exchange chromatography, liquid-liquid extraction, and reactive extraction. Main methods for the recovery of 2,3-butanediol include steam stripping, pervaporation, and solvent extraction. No single method has proved to be simple and efficient, and improvements are especially needed with regard to yield, purity, and energy consumption. Perspectives for an improved downstream processing of biologically produced diols, especially 1,3-propanediol are discussed based on our own experience and recent work. It is argued that separation technologies such as aqueous two-phase extraction with short chain alcohols, pervaporation, reverse osmosis, and in situ extractive or pervaporative fermentations deserve more attention in the future.

  2. Evolution from spherical single-particle structure to stable triaxiality at high spins in {sup 140}Nd

    SciTech Connect

    Petrache, C.M.; Fantuzi, M.; LoBianco, G.; Mengoni, D.; Neusser-Neffgen, A.; Huebel, H.; Al-Khatib, A.; Bringel, P.; Buerger, A.; Nenoff, N.; Schoenwasser, G.; Singh, A.K.; Ragnarsson, I.; Hagemann, G.B.; Herskind, B.; Jensen, D.R.; Sletten, G.; Fallon, P.; Goergen, A.; Bednarczyk, P.

    2005-12-15

    The level structure of {sub 60}{sup 140}Nd{sub 80} has been established up to spin 48 by in-beam {gamma}-ray spectroscopy by use of the {sup 96}Zr({sup 48}Ca, 4n) reaction. High-fold {gamma}-ray coincidences were measured with the EUROBALL spectrometer. Twelve new rotational bands have been discovered at high spins. They are interpreted as being formed in a deep triaxial minimum at {epsilon}{sub 2}{approx_equal}0.25 and {gamma}{approx_equal}35 deg. Possible configurations are assigned to the observed bands on the basis of configuration-dependent cranked Nilsson-Strutinsky calculations.

  3. Finite violations of a Bell inequality for high spin: An optical realization

    SciTech Connect

    Gerry, Christopher C.; Albert, Jaroslav

    2005-10-15

    Some years ago Peres [Phys. Rev. A 46, 4413 (1992)] described a gedanken experiment for a pair of spatially spin j particles in a singlet state and showed using with a dichotomic observable (essentially a parity operator) that Bell's theorem in the form of the Clauser-Home-Shimony-Holt (CHSH) inequality is violated by a constant amount (24%) in the limit j{yields}{infinity}. In this paper we present a scheme for an optical realization of a state that is very close to the spin-j singlet state using two traveling-wave modes of the quantized field using a 50:50 beam splitter with an input number state. A near-singlet states comes about because the binomial output state of the beam splitter can be written as a sum in terms of states in the form vertical bar j,m>{sub 1}x vertical bar j,-m>{sub 2}, each state being associated with a Holstein-Primakoff realization of the su(2) spin algebra in terms of the Bose operators of each of the field modes, where j=N/2, N being the number of photons passing through the beam splitter. The binomial state can violate the CHSH inequality to a greater degree than does the singlet state.

  4. High-spin iron(II) as a semitransparent partner for tuning europium(III) luminescence in heterodimetallic d-f complexes.

    PubMed

    Edder, C; Piguet, C; Bünzli, J C; Hopfgartner, G

    2001-07-16

    The segmental ligand 2-[6-(N,N-diethylcarbamoyl)pyridin-2-yl]-1,1'-dimethyl-5,5'-methylene-2'-(6-methylpyridine-2-yl)bis[1H-benzimidazole] (L3) reacts with a stoichiometric mixture of LnIII (Ln = La, Eu, Gd) and M(II) (M = Zn, Fe) in acetonitrile to produce selectively the heterodimetallic triple-stranded helicates (HHH)-[LnM(L3)3]5+. In these complexes, M(II) is pseudooctahedrally coordinated by the three wrapped bidentate binding units, thus forming a noncovalent tripod which organizes the three unsymmetrical tridentate segments to give ninefold coordination to LnIII. The introduction of a methyl group at the 6 position of the terminal pyridine in L3 sterically reduces the complexing ability of the bidentate segment for M(II). Spectroscopic (ESI-MS, UV/Vis/NIR, NMR), magnetic and electrochemical measurements show that 1) the head-to-head-to-head triple helical complexes (HHH)-[LnM(L3)3]5+ are quantitatively formed in solution only for ligand concentrations larger than 0.01 M, 2) FeII adopts a pure high-spin electronic configuration in (HHH)-[LnFe(L3)3]5+ and 3) the FeII/FeIII oxidation process is prevented by steric constraints. Detailed photophysical studies of (HHH)-[Eu-Zn(L3)3]5+ confirm that the pseudotricapped trigonal-prismatic lanthanide coordination site is not affected by the methyl groups bound to the terminal pyridine, thus leading to significant Eu-centered emission upon UV irradiation. In (HHH)-[EuFe(L3)3]5+, a resonant intramolecular Eu-->Fe(II)hs energy transfer partially quenches the Eu-centered luminescence; however, the residual red emission demonstrates that high-spin iron(II) is compatible with the sensitization of Eu(III) in heterodimetallic d-f complexes. The influence of the electronic configuration of Fe(II) on the efficiency of Eu(III)-->Fe(II) energy-transfer processes is discussed together with its consequence for the design of optically active spin-crossover supramolecular devices.

  5. High-spin isomers in some of the heaviest nuclei: Spectra, decays, and population

    SciTech Connect

    Adamian, G. G.; Antonenko, N. V.; Scheid, W.

    2010-02-15

    The isotopic dependence of two-quasiparticle isomeric states in Fm and No is treated for future experiments. The population of the isomeric states in evaporation residues is considered. In several even isotopes of Rf, Sg, Hs, and Ds, the K isomers and their decay modes are predicted. An alpha-decay chain through the isomeric states of superheavy nuclei is demonstrated for the first time and proposed for the experimental verification.

  6. Electron paramagnetic resonance and Mössbauer spectroscopy and density functional theory analysis of a high-spin Fe(IV)-oxo complex.

    PubMed

    Gupta, Rupal; Lacy, David C; Bominaar, Emile L; Borovik, A S; Hendrich, Michael P

    2012-06-13

    High-spin Fe(IV)-oxo species are known to be kinetically competent oxidants in non-heme iron enzymes. The properties of these oxidants are not as well understood as the corresponding intermediate-spin oxidants of heme complexes. The present work gives a detailed characterization of the structurally similar complexes [Fe(IV)H(3)buea(O)](-), [Fe(III)H(3)buea(O)](2-), and [Fe(III)H(3)buea(OH)](-) (H(3)buea = tris[(N'-tert-butylureaylato)-N-ethylene]aminato) using Mössbauer and dual-frequency/dual-mode electron paramagnetic resonance (EPR) spectroscopies. The [Fe(IV)H(3)buea(O)](-) complex has a high-spin (S = 2) configuration imposed by the C(3)-symmetric ligand. The EPR spectra of the [Fe(IV)H(3)buea(O)](-) complex presented here represent the first documented examples of an EPR signal from an Fe(IV)-oxo complex, demonstrating the ability to detect and quantify Fe(IV) species with EPR spectroscopy. Quantitative simulations allowed the determination of the zero-field parameter, D = +4.7 cm(-1), and the species concentration. Density functional theory (DFT) calculations of the zero-field parameter were found to be in agreement with the experimental value and indicated that the major contribution to the D value is from spin-orbit coupling of the ground state with an excited S = 1 electronic configuration at 1.2 eV. (17)O isotope enrichment experiments allowed the determination of the hyperfine constants ((17)O)A(z) = 10 MHz for [Fe(IV)H(3)buea(O)](-) and ((17)O)A(y) = 8 MHz, ((17)O)A(z) = 12 MHz for [Fe(III)H(3)buea(OH)](-). The isotropic hyperfine constant (((17)O)A(iso) = -16.8 MHz) was derived from the experimental value to allow a quantitative determination of the spin polarization (ρ(p) = 0.56) of the oxo p orbitals of the Fe-oxo bond in [Fe(IV)H(3)buea(O)](-). This is the first experimental determination for non-heme complexes and indicates significant covalency in the Fe-oxo bond. High-field Mössbauer spectroscopy gave an (57)Fe A(dip) tensor of (+5.6, +5

  7. A High-Spin Rate Measurement Method for Projectiles Using a Magnetoresistive Sensor Based on Time-Frequency Domain Analysis

    PubMed Central

    Shang, Jianyu; Deng, Zhihong; Fu, Mengyin; Wang, Shunting

    2016-01-01

    Traditional artillery guidance can significantly improve the attack accuracy and overall combat efficiency of projectiles, which makes it more adaptable to the information warfare of the future. Obviously, the accurate measurement of artillery spin rate, which has long been regarded as a daunting task, is the basis of precise guidance and control. Magnetoresistive (MR) sensors can be applied to spin rate measurement, especially in the high-spin and high-g projectile launch environment. In this paper, based on the theory of a MR sensor measuring spin rate, the mathematical relationship model between the frequency of MR sensor output and projectile spin rate was established through a fundamental derivation. By analyzing the characteristics of MR sensor output whose frequency varies with time, this paper proposed the Chirp z-Transform (CZT) time-frequency (TF) domain analysis method based on the rolling window of a Blackman window function (BCZT) which can accurately extract the projectile spin rate. To put it into practice, BCZT was applied to measure the spin rate of 155 mm artillery projectile. After extracting the spin rate, the impact that launch rotational angular velocity and aspect angle have on the extraction accuracy of the spin rate was analyzed. Simulation results show that the BCZT TF domain analysis method can effectively and accurately measure the projectile spin rate, especially in a high-spin and high-g projectile launch environment. PMID:27322266

  8. A High-Spin Rate Measurement Method for Projectiles Using a Magnetoresistive Sensor Based on Time-Frequency Domain Analysis.

    PubMed

    Shang, Jianyu; Deng, Zhihong; Fu, Mengyin; Wang, Shunting

    2016-06-16

    Traditional artillery guidance can significantly improve the attack accuracy and overall combat efficiency of projectiles, which makes it more adaptable to the information warfare of the future. Obviously, the accurate measurement of artillery spin rate, which has long been regarded as a daunting task, is the basis of precise guidance and control. Magnetoresistive (MR) sensors can be applied to spin rate measurement, especially in the high-spin and high-g projectile launch environment. In this paper, based on the theory of a MR sensor measuring spin rate, the mathematical relationship model between the frequency of MR sensor output and projectile spin rate was established through a fundamental derivation. By analyzing the characteristics of MR sensor output whose frequency varies with time, this paper proposed the Chirp z-Transform (CZT) time-frequency (TF) domain analysis method based on the rolling window of a Blackman window function (BCZT) which can accurately extract the projectile spin rate. To put it into practice, BCZT was applied to measure the spin rate of 155 mm artillery projectile. After extracting the spin rate, the impact that launch rotational angular velocity and aspect angle have on the extraction accuracy of the spin rate was analyzed. Simulation results show that the BCZT TF domain analysis method can effectively and accurately measure the projectile spin rate, especially in a high-spin and high-g projectile launch environment.

  9. Perpendicular Magnetic Anisotropy and High Spin Polarization in Tetragonal Fe4N /BiFeO3 Heterostructures

    NASA Astrophysics Data System (ADS)

    Yin, Li; Mi, Wenbo; Wang, Xiaocha

    2016-12-01

    The tetragonal Fe4N /BiFeO3(001 ) heterostructures aimed at simultaneously gaining the perpendicular magnetic anisotropy (PMA) and high spin polarization have been investigated by the first-principles method. It is found that Fe4N with FeAFeB termination is better for achieving interfacial and inner PMA simultaneously than (FeB)2N termination. When the positions of interfacial FeA and FeB relative to Fe in BiFeO3 are changed, the PMA in Fe4N transforms into the in-plane magnetic anisotropy. Especially, PMA in Fe4N near the heterointerfaces depends on the direction of ferroelectric polarization in BiFeO3 . Finally, the interfacial and inner PMA of Fe4N along with high spin polarization appear in the stable FeAFeB/Fe -O2 case owing to the 3 d -3 d orbital hybridization. These results provide the opportunities for developing multifunctional spintronic devices.

  10. Analysis of heavy-rain-producing elevated thunderstorms in the MO-KS-OK region of the United States

    NASA Astrophysics Data System (ADS)

    McCoy, Laurel

    Most elevated thunderstorms in the United States occur in the Midwest, with a maximum in eastern Kansas (Colman 1990a). Elevated thunderstorms are defined as thunderstorms that occur over a very stable surface boundary layer (Colman 1990b). They may be better defined as convection occurring over a stable layer near the surface, essentially cut off from surface-based instability (Corfidi et al. 2006). Elevated mesoscale convective systems produce 30-70% of the total rainfall during the warm season over the Central Plains (Moore et al. 2003). 1.1 Purpose Elevated thunderstorms are still not very well understood. Elevated convection can take a variety of forms, and can be very similar to surface-based convection. Corfidi et al. (2006) describe the challenge of finding the originating layer of parcels making up a convective cloud. Surface-based convection often incorporates elevated parcels, and elevated convection can bring surface parcels into its updraft. The distinction between the two types of storms can be defined by where most of the parcels originate. This becomes especially hard to distinguish as convection transitions from surface-based to elevated and vice-versa (Corfidi et al. 2006). Colman (1990a), in his study, used three criteria to delineate elevated thunderstorm station reports from surface-based thunderstorm station reports: 1) The observation must lie on the cold side of an analyzed front that shows a clear contrast in temperature, dew-point temperature, and wind. 2) The station's wind, temperature, and dew-point temperature must be qualitatively similar to the immediately surrounding values. 3) The surface air on the warm side of the analyzed front must have a higher equivalent potential temperature (thetae) than the air on the cold side of the front (Colman 1990a). These three criteria have been incorporated into several studies since for the evaluation of elevated convection (e.g., Grant 1995; Rochette and Moore 1996; Moore et al. 1998; Moore et

  11. Occurrence of Staphylococcus aureus in raw milk produced in dairy farms in São Paulo state, Brazil

    PubMed Central

    Fagundes, Helena; Barchesi, Luciana; Filho, Antonio Nader; Ferreira, Luciano Menezes; Oliveira, Carlos Augusto Fernandes

    2010-01-01

    The objective of the present study was to evaluate the occurrence of Staphylococcus aureus in milk produced in 37 farms located in the regions of Ribeirão Preto and São Carlos, state of São Paulo, Brazil. Two-hundred and eight samples of milk from individual cows showing subclinical mastitis, and 37 samples of bulk tank milk were analyzed. S. aureus strains were detected in 18 (7.3%) milk samples: 14 (6.7%) from samples of individual cows, and 4 (10.8%) from bulk tank milk. Two individual milk samples (14.3%) and two bulk milk samples contained enterotoxigenic S. aureus. PFGE analysis revealed the genetic heterogeneity of the strains isolated from raw milk, which presented to 13 S. aureus patterns. Results confirmed the potential transmission of staphylococcal food poisoning to consumers via milk of cows affected by subclinical mastitis, mainly when raw milk is ingested. PMID:24031507

  12. Detoxification of malachite green by Pleurotus florida laccase produced under solid-state fermentation using agricultural residues.

    PubMed

    Sathishkumar, Palanivel; Palvannan, Thayumanavan; Murugesan, Kumarasamy; Kamala-Kannan, Seralathan

    2013-01-01

    Laccase was produced from Pleurotus florida under solid-state fermentation, and the production was optimized by response surface methodology. The predicted maximum laccase production of 8.81 U g(-1) was obtained by the optimum concentration of malt extract, banana peel, wheat bran and CuSO4, which was found to be 0.69 g, 10.61 g, 10.68 g and 77.15 ppm, respectively. The validation results suggested that the laccase production was 7.96 U g(-1) in the optimized medium, which was close to the predicted value. Decolorization efficiency of P. florida laccase was evaluated against malachite green (MG). Rapid decolorization of MG dye was observed, and a dark-coloured precipitate was formed in the reaction mixture. HPLC analysis indicated that the laccase enzyme degraded MG by the demethylation process. The toxicity of MG was reduced to 67% after the treatment with laccase, which was confirmed by a phytotoxicity study.

  13. Measurement of the mass and width of the Z 0-particle from multihadronic final states produced in e +e - annihilations

    NASA Astrophysics Data System (ADS)

    Aarnio, P.; Abreu, P.; Adam, W.; Adrianos, P.; Adye, T.; Akopdzhanov, G.; Alekseev, G.; Allaby, J.; Allen, P.; Allport, P.; Almehed, S.; Alvsvaag, S.; Amaldi, U.; Anassontzis, E.; Antilogus, P.; Apel, W.; Aria, E.; Asman, B.; Astesan, F.; Ferreres, C. Astor; Aubret, C.; Augustin, J.; Augustinus, A.; Baillon, P.; Barao, F.; Barbiellini, G.; Bardin, D.; Barlag, S.; Barlow, J.; Baroncelli, A.; Barranco-Luque, M.; Barreira, G.; Barring, O.; Bartl, W.; Bates, M.; Baubillier, M.; Becks, K.; Beeston, C.; Bell, W.; Belokopytov, I.; Beltran, P.; Benedic, D.; Benlloch, J.; Berggren, M.; Berst, J.; Bertrand, D.; Biagi, S.; Bianchi, F.; Bibby, J.; Bilenky, M.; Billoir, P.; Bingefors, N.; Bjarne, J.; Bloch, D.; Bogolubov, P.; Bollini, D.; Bolognese, T.; Bonapart, M.; Booth, P.; Boratav, M.; Borgeaud, P.; Borner, H.; Bosio, C.; Botner, O.; Bouquet, B.; Bozzo, M.; Braibant, S.; Branchini, P.; Brand, C.; Brand, K.; Bricman, C.; Brown, R.; Brummer, N.; Brunet, J.; Bugge, L.; Buran, T.; Burmeister, H.; Buttar, C.; Buytaert, J.; Cabras, G.; Caccia, M.; Cairanti, S.; Calvi, M.; Rozas, A. Camacho; Campagne, J.; Campion, A.; Camporesi, T.; Canale, V.; Cao, F.; Carroll, L.; Caso, C.; Castelli, E.; Castillo Gimenez, V.; Cattai, A.; Caoallo, F.; Cerrito, L.; Chadwick, G.; Charpentier, P.; Checchia, P.; Chelkov, G.; Chevalier, L.; Chiccoli, C.; Chiliapnikov, P.; Chorowicz, V.; Christophel, E.; Cirio, R.; Clara, M.; Contreras, J.; Contri, R.; Couchot, F.; Courty, P.; Crawley, H.; Crennell, D.; Cresti, M.; Croissiaux, M.; Crosetti, G.; Crosland, N.; Crozon, M.; Cuevas Maestro, J.; Curwen, L.; Czellar, S.; Dahl-Jensen, E.; Dalmagne, B.; Dam, M.; Damgaard, G.; Darbo, G.; Daubie, E.; Davenport, M.; de Angelis, A.; de Beer, M.; de Clercq, C.; de Groot, N.; de Jode, M.; de La Vaissiere, C.; Delikaris, D.; Delpierre, P.; di Ciaccio, L.; Diddens, A.; Dijkstra, H.; Dimitriou, N.; Djama, F.; Dolbeau, J.; Doroba, K.; Downs, R.; Dracos, M.; Drees, J.; Dris, M.; Du, S.; Dulinski, W.; Dzhelyadin, R.; Edwards, D.; Eek, L.; Eerola, P.; Ekelof, T.; Ekspong, G.; Ellila, M.; Engel, J.; Falaleev, V.; Fenyuk, A.; Fernandez Alonso, M.; Ferrer, A.; Ferroni, S.; Filippas, T.; Firestone, A.; Fischer, H.; Fjeld, B.; Flinn, M.; Foeth, H.; Fokitis, E.; Folegati, P.; Fontanelli, F.; Forsbach, H.; Fraissard, D.; Franek, B.; Fransson, K.; Frenkiel, P.; Fries, D.; Froberger, J.; Frodesen, A.; Fruhwirth, R.; Fulda-Quenzer, F.; Fuster, J.; Gago, J.; Gaillard, M.; Galeazzi, G.; Gamba, D.; Garat, C.; Gaspar, C.; Gasparini, U.; Gavillet, P.; Gawne, S.; Gazis, E.; Genat, J.; Gerber, J.; Glitza, K.; Gokieli, R.; Golovatyuk, V.; Gomes, P.; Gomez Y Cadenas, J.; Goobar, A.; Gopal, G.; Gorbics, M.; Goret, B.; Gorski, B.; Goujon, G.; Gracco, V.; Grant, A.; Grard, F.; Graziani, E.; Grillet, J.; Gros, M.; Gros, M.; Grosdidier, G.; Grossetete, B.; Grung, B.; Guglielmi, L.; Gumenyuk, S.; Guy, J.; Hahn, F.; Haider, S.; Haissinski, J.; Hajduk, Z.; Hakansson, A.; Hallgren, A.; Hamacher, K.; Hamel de Monchenault, G.; Harris, F.; Heck, B.; Herbst, I.; Hernandez, J.; Herquet, P.; Herr, H.; Higon, E.; Hilke, H.; Hofmann, H.; Hofmokl, T.; Holmgren, S.; Hooper, J.; Horisberger, R.; Houlden, M.; Hrisoho, A.; Hrubec, J.; Huitu, K.; Hulth, P.; Hultqvist, K.; Husson, D.; Hyams, B.; Imbault, D.; Innocente, M.; Ioannou, P.; Iversen, P.; Jackson, J.; Jalocha, P.; Jarlskog, G.; Jarry, P.; Jean-Marie, B.; Joensuu, J.; Johansson, E.; Johansson, H.; Johansson, S.; Jonker, M.; Juillot, P.; Kadyrov, R.; Kadyshevsky, V.; Kalkanis, G.; Kalmus, G.; Kantardjian, G.; Katsanevas, S.; Katsoufis, E.; Keranen, R.; Kesteman, J.; Khomenko, B.; Khovanski, N.; King, B.; Kisielewski, B.; Klein, H.; Klempt, W.; Klovning, A.; Kluit, P.; Koene, B.; Kokkinias, P.; Kontaxis, I.; Kopf, M.; Koratzinos, M.; Korcyl, K.; Korytov, A.; Korzen, B.; Kostarakis, P.; Kourkoumelis, C.; Kremizis, P.; Kreuzberger, T.; Krolikowski, J.; Krstic, J.; Kucewicz, W.; Kuhn, G.; Kurvinen, K.; Laakso, M.; Lambropoulos, C.; Lanceri, L.; Langerveld, D.; Lapin, V.; Laugier, J.; Lauhakangas, R.; Laurikainen, P.; Lavigne, B.; Le Grand, J.; Lebbolo, H.; Lebreton, E.; Leder, G.; Lemonne, J.; Lenzen, G.; Lepeltier, V.; Lidbury, J.; Lieb, E.; Lillestol, E.; Lillethun, E.; Lippi, I.; Llosa, R.; Loerstad, B.; Loken, J.; Lopez Aguera, M.; Lorenz, P.; Loukas, D.; Lucock, R.; Lund-Jensen, B.; Lutz, P.; Lyons, L.; Maehlum, G.; Maeland, O.; Maillard, J.; Makoussis, A.; Maltezos, A.; Mandl, F.; Marco, J.; Marin, J.; Markou, A.; Mathis, L.; Matteuzzi, C.; Matthiae, G.; Mattsson, L.; Mayet, N.; Mazzucato, M.; Mc Cubbin, M.; Mc Kay, R.; Menichetti, E.; Meroni, C.; Meyer, W.; Michael, M.; Michalowski, J.; Mitaroff, W.; Mitselmakher, G.; Mjoernmark, U.; Moa, T.; Moeller, R.; Moenig, K.; Monge, R.; Montalbano, G.; Morettini, P.; Mueller, H.; Muller, H.; Mur, M.; Muryn, B.; Myatt, G.; Navarria, F.; Negri, P.; Nielsen, B.; Nigro, M.; Nikolaenko, V.; Noppe, J.; Nordberg, M.; Nounos, S.; Obraztsov, V.; Orava, R.; Ouraou, A.; Pagot, J.; Pain, R.; Pakonski, K.; Palka, H.; Palma Lopes, S.; Papadopoulou, T.; Pape, L.; Pasini, P.; Passeneau, J.; Passeneau, M.; Passeri, A.; Pattison, J.; Pegoraro, M.; Perevozchikov, V.; Perez, J.; Pernicka, M.; Perrotta, A.; Petrucci, G.; Pettersen, T.; Pimenta, M.; Pingot, O.; Pinori, C.; Pinsent, A.; Poiret, C.; Pol, M.; Poliakov, B.; Polok, G.; Poropat, P.; Privitera, P.; Pullia, A.; Pyyhtia, J.; Queru, P.; Quinton, S.; Rademakers, A.; Radojicic, D.; Ragazzi, S.; Ragazzon, R.; Range, W.; Raoul, J.; Ratoff, P.; Read, A.; Redaelli, N.; Regler, M.; Reid, D.; Reis, M.; Renton, P.; Resvanis, L.; Richard, F.; Ridky, J.; Rinaudo, G.; Romaya, A.; Romero, A.; Roncagliolo, I.; Ronchese, P.; Rongved, R.; Rosenberg, E.; Rossel, F.; Rosso, E.; Roudeau, P.; Rovelli, T.; Ruhlmann, V.; Ruiz, A.; Rybicki, K.; Saarikko, H.; Sacco, D.; Sacquin, Y.; Sadovsky, A.; Salgado, C.; Salt, J.; Samarin, A.; Sanchez, E.; Sanchis, E.; Sannino, M.; Schaeffer, M.; Schneider, H.; Scuri, F.; Sebastia, R.; Segar, A.; Sekulin, R.; Sessa, M.; Sette, G.; Seufert, R.; Shellard, R.; Siegrist, P.; Simonetti, S.; Simonetto, F.; Skaali, T.; Skeens, J.; Skjevling, G.; Smadja, G.; Smith, G.; Sosnowski, R.; Spang, K.; Spassov, T.; Spentzouris, P.; Spiriti, E.; Squarcia, S.; Staeck, H.; Stanescu, C.; Stavropoulos, G.; Stichelbaut, F.; Stocchi, A.; Strauss, J.; Strub, R.; Sundell, E.; Szczekowski, M.; Szeptycka, M.; Szymanski, P.; Tavernier, S.; Theodosiou, G.; Tilquin, A.; Timmermans, J.; Tkachev, L.; Toet, D.; Topp-Jorgensen, S.; Topphol, A.; Tortora, L.; Treille, D.; Trevisan, U.; Tristram, C.; Troncon, C.; Truong, T.; Tsyganov, E.; Turala, M.; Turchetta, R.; Turlot, J.; Turluer, M.; Tuuva, T.; Tyapkin, I.; Tyndel, M.; Tyurin, N.; Udo, F.; Ueberschaer, S.; Ullaland, O.; Valenti, G.; van Apeldoorn, G.; van Dam, P.; van Doninck, W.; van Eijk, B.; van Eijndhoven, N.; Vander Velde, C.; Vanuxem, J.; Varela, J.; Vaz, P.; Vegni, G.; Veitch, M.; Vela, E.; Velasco, J.; Ventura, L.; Venus, W.; Verbeure, F.; Vergezac, P.; Vilanova, D.; Viseu Melo, L.; Vlasov, E.; Vlassopoulos, S.; Vodopianov, A.; Vollmer, M.; Volponi, S.; Voulgaris, G.; Voutilainen, M.; Vrba, V.; Wahlen, H.; Walck, C.; Waldner, F.; Wayne, M.; Weilhammer, P.; Werner, J.; Wetherell, A.; Wickens, J.; Williams, W.; Winter, M.; Witecki, B.; Wormser, G.; Woschnagg, K.; Yamdagni, N.; Yelton, J.; Zaitsev, A.; Zalewska, A.; Zalewski, P.; Zevgolatakos, E.; Zhang, G.; Zimin, N.; Zinchenko, A.; Zito, M.; Zitoun, R.; Zukanovich Funchal, R.; Zumerle, G.; Delphi Collaboration

    1989-11-01

    First measurements of the mass and width of the Z 0 performed at the newly commissioned LEP Collider by the DELPHI Collaboration are presented. The measuements are derived from the study of multihadronic final states produced in e +e - annihilations at several energies around the Z 0 mass. The values found for the mass and width are M(Z 0)=91.06±0.09 (stat) ±0.045 (syst.) GeV and Γ(Z 0)=2.42±0.21 (stat.) GeV respectively, froma three-parameter fit to the line shape. A two-parameter fit in the framework of the standard model yields for the number of light neutrino species Nν=2.4±0.4 (stat.) ±0.5 (syst.).

  14. A Thermostable Crude Endoglucanase Produced by Aspergillus fumigatus in a Novel Solid State Fermentation Process Using Isolated Free Water

    PubMed Central

    Saqib, Abdul A. N.; Farooq, Ansa; Iqbal, Maryam; Hassan, Jalees Ul; Hayat, Umar; Baig, Shahjahan

    2012-01-01

    Aspergillus fumigatus was grown on chopped wheat straw in a solid state fermentation (SSF) process carried out in constant presence of isolated free water inside the fermentation chamber. The system allowed maintaining a constant vapor pressure inside the fermentor throughout the fermentation process. Crude endoglucanase produced by A. fumigatus under such conditions was more thermostable than previously reported enzymes of the same fungal strain which were produced under different conditions and was also more thermostable than a number of other previously reported endoglucanases as well. Various thermostability parameters were calculated for the crude endoglucanase. Half lives (T 1/2) of the enzyme were 6930, 866, and 36 min at 60°C, 70°C, and 80°C, respectively. Enthalpies of activation of denaturation (ΔH D*) were 254.04, 253.96, and 253.88 K J mole−1, at 60°C, 70°C and 80°C, respectively, whereas entropies of activation of denaturation (ΔS D*) and free energy changes of activation of denaturation (ΔG D*) were 406.45, 401.01, and 406.07 J mole−1 K−1 and 118.69, 116.41, and 110.53 K J mole−1 at 60°C, 70°C and 80°C, respectively. PMID:22919467

  15. Effect of pH and Temperature on Enzyme Activity of Chitosanase Produced Under Solid Stated Fermentation by Trichoderma spp.

    PubMed

    da Silva, Luis C A; Honorato, Talita L; Cavalcante, Rosane S; Franco, Telma T; Rodrigues, Sueli

    2012-03-01

    Trichoderma strains were extensively studied as biocontrol agents due to their ability of producing hydrolytic enzymes, which are considered key enzymes because they attack the insect exoskeleton allowing the fungi infection. The present work aimed to evaluate the ability of chitosanase production by four Trichoderma strains (T. harzianum, T. koningii, T. viride and T. polysporum) under solid stated fermentation and to evaluate the effect of pH and temperature on enzyme activity. pH strongly affected the enzyme activity from all tested strains. Chitosanase from T. harzianum and T. viride presented optimum activity at pH 5.0 and chitosanase from T. koningii and T. polysporum presented optimum activity at pH 5.5. Temperature in the range of 40-50°C did not affect enzyme activity. T. polysporum was found as the most promising strain to produce chitosanase with maximal enzyme activity of about 1.4 IU/gds, followed by T. viride (~1.2 IU/gds) and T. harzianum (1.06 IU/gds).

  16. The effect of the United States Great Lakes on the maintenance of derecho-producing mesoscale convective systems.

    NASA Astrophysics Data System (ADS)

    Bentley, M.; Sparks, J.; Graham, R.

    2003-04-01

    The primary aim of this research is to investigate the influence of the United States Great Lakes on the intensity of mesoscale convective systems (MCSs). One of the greatest nowcast challenges during the warm season is anticipating the impact of the Great Lakes on severe convection, particularly MCSs capable of producing damaging widespread windstorms known as derechos. Since a major derecho activity corridor lies over the Great Lakes region, it is important to understand the effects of the Lakes on the intensity and propagation of severe wind producing MCSs. Specific objectives of the research include: 1) The development of a short-term climatology of MCS events that have impacted the Great Lakes region over the past seven years; 2) An analysis of radar, satellite, surface (including buoy and lighthouse observations), and lake surface temperature data to determine the environmental conditions impacting the evolution of MCSs passing over a Great Lake; 3) An examination of MCS initiation times and seasonal frequencies of occurrence to delineate temporal consistencies in MCS evolution due to changing lake surface temperatures; and 4) The development of conceptual and forecast models to help anticipate MCS intensity and morphology as these systems interact with the Great Lakes environment.

  17. Highly spin-polarized current in Co-substituted Fe{sub 3}O{sub 4} epitaxial thin films at room temperature

    SciTech Connect

    Takahashi, Masanao; Ohshima, Toshiyuki; Yamahara, Hiroyasu; Seki, Munetoshi Tabata, Hitoshi

    2014-12-07

    Epitaxial thin films of cobalt ferrite Co{sub x}Fe{sub 3−x}O{sub 4} (x = 0.0, 0.5, and 1.0) were fabricated on α-Al{sub 2}O{sub 3} (001) substrates using pulsed laser deposition. It was found that the coercive force of the cobalt ferrite films could be tuned by changing the Co content. The films prepared under low oxygen pressure (1.0 × 10{sup −6 }Pa) showed semiconducting behavior even for x = 1.0. X-ray photoelectron spectroscopy revealed that the Co ions were 2{sup +} for all compositions. On the other hand, it was found that the Fe ions were in the Fe{sup 2+}/Fe{sup 3+} valence state, which may cause small-polaron hopping among the Fe-3d electrons in the films. An anomalous Hall effect was observed in the Co{sub 0.5}Fe{sub 2.5}O{sub 4} film even at 300 K, suggesting that carriers in the films were highly spin-polarized at room temperature.

  18. Essays on the investment behavior of independent power producers in the United States electricity industry under regulatory restructuring

    NASA Astrophysics Data System (ADS)

    Yan, Jingming

    2002-09-01

    In recent years, there have been efforts at both the federal and state level to introduce greater competition and markets into the US electricity industry through regulatory restructuring. A key to the success of such efforts is the ability of the restructuring to attract investment from non-utility, independent power producers (IPPs). The two essays in this dissertation examine empirically the investment behavior of IPPs under the regulatory restructuring between 1996 and 2000. In both essays, the effects of restructuring on a firm's investment decision are decomposed into the effects that work through the investment cost and that through the expected profit from the investment. The first essay studies the entry behavior of IPPs under the restructuring. The main finding of the essay is that the restructuring has done little to lower the entry barrier faced by IPPs-high fixed cost to entry is still a main factor that hinders IPP investment. The second essay studies IPPs' decisions between investing through building new power plants ("make") and investing through acquiring divested plants ("buy"). It finds that the availability of the "buy" option does not "squeeze" out investment on new capacities. IPPs that chose to "buy" did so because they expected a lower return from "make" and hence would not have switched their investment to new capacities even if the "buy" option were not available. Therefore, divestiture is a viable policy tool for state regulators to attract more IPP investment.

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

    SciTech Connect

    Walker, P.M.; Purry, C.S.; Gelletly, W.

    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.

  20. Use of mesophilic fungal amylases produced by solid-state fermentation in the cold hydrolysis of raw babassu cake starch.

    PubMed

    de Castro, Aline Machado; de Andréa, Thiago Vetter; Castilho, Leda dos Reis; Freire, Denise Maria Guimarães

    2010-11-01

    Amylases constitute one of the most important groups of industrial enzymes, presenting several applications, such as in the food, textile, and ethanol manufacturing. In this work, a starchy residue from the Brazilian agroindustry, namely babassu cake, was used for the production of amylases by solid-state fermentation and for obtaining sugar hydrolysates, which can be used as building blocks for future bioconversions. Eight filamentous fungi from the genera Aspergillus and Penicillium were screened. Regarding amylase production, A. awamori strains showed well-balanced endoamylase and exoamylase activities, while A. wentii produced an amylolytic complex much richer in the endo-acting enzymes. Simultaneous liquefaction and saccharification using the crude enzyme extracts from the four most promising fungal strains was then investigated applying DOE techniques. The highest total reducing sugar content (24.70 g L(-1)) was obtained by the crude extract from A. awamori IOC-3914, corresponding to a hydrolysis yield of 52% of total starch in the cake, while A. awamori IOC-3915 produced the most appropriate extract in terms of glucose release (maximum of 5.52 g L(-1)). Multivariate analysis of the DOE studies indicated that these extracts showed their best performance at 50-57 degrees C under acid conditions (pH 3.6-4.5), but were also able to act satisfactorily under milder conditions (36 degrees C and pH 5.0), when TRS and glucose released were about 65% of the maximum values obtained. These data confirm the high potential of the enzyme extracts under study for cold hydrolysis of starch.

  1. First Report of a Verona Integron-Encoded Metallo-β-Lactamase-Producing Klebsiella pneumoniae Infection in a Child in the United States.

    PubMed

    Tamma, Pranita D; Suwantarat, Nuntra; Rudin, Susan D; Logan, Latania K; Simner, Patricia J; Rojas, Laura J; Mojica, Maria F; Carroll, Karen C; Bonomo, Robert A

    2016-09-01

    We report the first case of a child in the United States infected with an organism producing a Verona Integron-Encoded Metallo-β-Lactamase. This child succumbed to a ventilator-associated pneumonia caused by a Klebsiella pneumoniae producing this resistance mechanism.

  2. Mesoscopic superconductivity and high spin polarization coexisting at metallic point contacts on Weyl semimetal TaAs.

    PubMed

    Aggarwal, Leena; Gayen, Sirshendu; Das, Shekhar; Kumar, Ritesh; Süß, Vicky; Felser, Claudia; Shekhar, Chandra; Sheet, Goutam

    2017-01-10

    A Weyl semimetal is a topologically non-trivial phase of matter that hosts mass-less Weyl fermions, the particles that remained elusive for more than 80 years since their theoretical discovery. The Weyl semimetals exhibit unique transport properties and remarkably high surface spin polarization. Here we show that a mesoscopic superconducting phase with critical temperature Tc=7 K can be realized by forming metallic point contacts with silver (Ag) on single crystals of TaAs, while neither Ag nor TaAs are superconductors. Andreev reflection spectroscopy of such point contacts reveals a superconducting gap of 1.2 meV that coexists with a high transport spin polarization of 60% indicating a highly spin-polarized supercurrent flowing through the point contacts on TaAs. Therefore, apart from the discovery of a novel mesoscopic superconducting phase, our results also show that the point contacts on Weyl semimetals are potentially important for applications in spintronics.

  3. Test of the Anti-de Sitter-Space/Conformal-Field-Theory Correspondence Using High-Spin Operators

    SciTech Connect

    Benna, M. K.; Benvenuti, S.; Klebanov, I. R.; Scardicchio, A.

    2007-03-30

    In two remarkable recent papers the planar perturbative expansion was proposed for the universal function of the coupling appearing in the dimensions of high-spin operators of the N=4 super Yang-Mills theory. We study numerically the integral equation derived by Beisert, Eden, and Staudacher, which resums the perturbative series. In a confirmation of the anti-de Sitter-space/conformal-field-theory (AdS/CFT) correspondence, we find a smooth function whose two leading terms at strong coupling match the results obtained for the semiclassical folded string spinning in AdS{sub 5}. We also make a numerical prediction for the third term in the strong coupling series.

  4. Mesoscopic superconductivity and high spin polarization coexisting at metallic point contacts on Weyl semimetal TaAs

    NASA Astrophysics Data System (ADS)

    Aggarwal, Leena; Gayen, Sirshendu; Das, Shekhar; Kumar, Ritesh; Süß, Vicky; Felser, Claudia; Shekhar, Chandra; Sheet, Goutam

    2017-01-01

    A Weyl semimetal is a topologically non-trivial phase of matter that hosts mass-less Weyl fermions, the particles that remained elusive for more than 80 years since their theoretical discovery. The Weyl semimetals exhibit unique transport properties and remarkably high surface spin polarization. Here we show that a mesoscopic superconducting phase with critical temperature Tc=7 K can be realized by forming metallic point contacts with silver (Ag) on single crystals of TaAs, while neither Ag nor TaAs are superconductors. Andreev reflection spectroscopy of such point contacts reveals a superconducting gap of 1.2 meV that coexists with a high transport spin polarization of 60% indicating a highly spin-polarized supercurrent flowing through the point contacts on TaAs. Therefore, apart from the discovery of a novel mesoscopic superconducting phase, our results also show that the point contacts on Weyl semimetals are potentially important for applications in spintronics.

  5. Nuclear properties of the exotic high-spin isomer 178Hfm2 from collinear laser spectroscopy

    NASA Astrophysics Data System (ADS)

    Boos, N.; Le Blanc, F.; Krieg, M.; Pinard, J.; Huber, G.; Lunney, M. D.; Le Du, D.; Meunier, R.; Hussonnois, M.; Constantinescu, O.; Kim, J. B.; Briançon, Ch.; Crawford, J. E.; Duong, H. T.; Gangrski, Y. P.; Kühl, T.; Markov, B. N.; Oganessian, Yu. Ts.; Quentin, P.; Roussière, B.; Sauvage, J.

    1994-04-01

    The complete hyperfine spectrum in the optical transition 5d26s2 3P2-->5d6s26p 1P1 of 178Hfm2 was recorded by collinear laser spectroscopy using nanogram amounts of samples. The quadrupole moment and isomer shift were determined for the first time as well as a precise value and the sign of the magnetic dipole moment. The change in nuclear mean-square charge radius between the isomeric state 178Hfm2 and the ground state 178Hfg was evaluated as δ178.178m2=-0.059(9) fm2. From the hyperfine A and B factors the magnetic moment μ178m2I=+8.16(4) nuclear magnetons and the spectroscopic quadrupole moment Q178m2s=+6.00(7) b were were extracted.

  6. Steps Towards Large Scale Production of High-Spin Hafnium Isomers by Spallation Reactions

    DTIC Science & Technology

    2008-02-25

    production and accumulation of the nuclear isomer 178m2 Hafnium by spallation of hafnium targets with high-energy protons. The Hafnium yield will be...E.P. SHABALIN , Production of long–lived hafnium isomers in reactor irradiations, High Energy Density Physics 2 (2006) 48; [25] M.B. CHADWICK AND P.G...YOUNG, Calculations of the production cross–sections of high–spin isomeric states in Hafnium , Nuclear Science and Engineering 108 (1991) 117; [26

  7. Reactivity of H 2O 2 with radiation produced free radicals: Steady state radiolysis methods for estimating the rate constants

    NASA Astrophysics Data System (ADS)

    Kishore, Kamal; Moorthy, P. N.; Rao, K. N.

    A new steady state radiolysis method for the determination of the rate constants of reaction of H 2O 2 with solute radicals derived by reaction with radiation produced OH radicals is described. The values so obtained are comparable with the ones obtained by the method described by Soylemez and Balkas in the past. A method similar to the latter has been employed to determine the rate constant of reaction of H 2O 2 with solute radicals derived from e -aq reaction. In the case of the (CH 3) 2 COH radical which can be generated by either reaction of OH with isopropanol or e -aq with acetone, the three methods give values agreeing with each other within ± 15% (viz. 2.7 ± 0.4 × 10 5 dm 3 mol -1 s -1). The reaction of the solute radicals with H 2O 2 is considered in the light of known one-electron redox potentials, and the limitations of the applicability of the methods described here are discussed.

  8. Waveforms produced by a scalar point particle plunging into a Schwarzschild black hole: Excitation of quasinormal modes and quasibound states

    NASA Astrophysics Data System (ADS)

    Décanini, Yves; Folacci, Antoine; Ould El Hadj, Mohamed

    2015-07-01

    With the possibility of testing massive gravity in the context of black hole physics in mind, we consider the radiation produced by a particle plunging from slightly below the innermost stable circular orbit into a Schwarzschild black hole. In order to circumvent the difficulties associated with black hole perturbation theory in massive gravity, we use a toy model in which we replace the graviton field with a massive scalar field and consider a linear coupling between the particle and this field. We compute the waveform generated by the plunging particle and study its spectral content. This permits us to highlight and interpret some important effects occurring in the plunge regime which are not present for massless fields, such as (i) the decreasing and vanishing, as the mass parameter increases, of the signal amplitude generated when the particle moves on quasicircular orbits near the innermost stable circular orbit; and (ii) in addition to the excitation of the quasinormal modes, the excitation of the quasibound states of the black hole.

  9. Which kind of aromatic structures are produced during biomass charring? New insights provided by modern solid-state NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Knicker, Heike; Paneque-Carmona, Marina; Velasco-Molina, Marta; de la Rosa, José Maria; León-Ovelar, Laura Regina; Fernandez-Boy, Elena

    2017-04-01

    Intense research on biochar and charcoal of the last years has revealed that depending on the production conditions, the chemical and physical characteristics of their aromatic network can greatly vary. Since such variations are determining the behavior and stability of charred material in soils, a better understanding of the structural changes occurring during their heating and the impact of those changes on their function is needed. One method to characterize pyrogenic organic matter (PyOM) represents solid-state 13C NMR spectroscopy applying the cross polarization (CP) magic angle spinning technique (MAS). A drawback of this technique is that the quantification of NMR spectra of samples with highly condensed and proton-depleted structures is assumed to be bias. Typical samples with such attributes are charcoals produced at temperatures above 700°C under pyrolytic conditions. Commonly their high condensation degree leads to graphenic structures that are not only reducing the CP efficiency but create also a conductive lattice which acts as a shield and prevents the entering of the excitation pulse into the sample during the NMR experiments. Since the latter can damage the NMR probe and in the most cases the obtained NMR spectra show only one broad signal assignable to aromatic C, this technique is rarely applied for characterizing high temperature chars or soot. As a consequence, a more detailed knowledge of the nature of the aromatic ring systems is still missing. The latter is also true for the aromatic domains of PyOM produced at lower temperatures, since older NMR instruments operating at low magnetic fields deliver solid-state 13C NMR spectra with low resolution which turns a more detailed analysis of the aromatic chemical shift region into a challenging task. In order to overcome this disadvantages, modern NMR spectroscopy offers not only instruments with greatly improved resolution but also special pulse sequences for NMR experiments which allow a more

  10. Yield of radionuclides and isomers produced in the fragmentation of natW and 186W (97%) targets with protons at 630, 420 and 270 MeV

    NASA Astrophysics Data System (ADS)

    Karamian, S. A.; Adam, J.; 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.

    2004-07-01

    Yields and cross-sections of the radioactive nuclides produced after the irradiation of natural composition W and enriched 186W targets at the Dubna synchrocyclotron were measured using the γ-ray spectroscopy methods with high-resolution Ge detectors. Among the detected nuclides we identified the spallation and fission products. High-spin isomeric states in the Hf and Lu nuclides were populated and the isomer-to-ground state ratios could be estimated. The nuclide yields were calculated using the LAHET code at six different values of the proton energy in the range from 100 to 800 MeV both for the natW and enriched 186W targets. The measured isotope yields are in general good agreement with the calculations. A shortcoming of the code is the inability to predict isomer-to-ground state ratios. The experimental data show that the 177mLu, 178m2Hf and 179m2Hf high-spin isomers are produced with a 2.5 times higher yield in the 97% enriched 186W target as compared to the natW target under identical irradiation conditions. This makes significance for the creation of high-activity isomeric sources. The mass-distribution of the products and the fission-to-spallation ratio were also deduced and compared with theory prediction.

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

    SciTech Connect

    Li, J.; Hu, J.; Wang, H.; Wu, R. Q.

    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.

  12. High spin-polarization in ultrathin Co2MnSi/CoPd multilayers

    NASA Astrophysics Data System (ADS)

    Galanakis, I.

    2015-03-01

    Half-metallic Co2MnSi 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 Co2MnSi/CoPd multilayers. We show that these heterostructures combine high values of spin-polarization at the Co2MnSi spacer with the perpendicular magnetic anisotropy of binary compounds such as CoPd. Thus they could find application in spintronic/magnetoelectronic devices.

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

    SciTech Connect

    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.

  14. A multivendor phantom study comparing the image quality produced from three state-of-the-art SPECT-CT systems.

    PubMed

    Hughes, Tyler; Celler, Anna

    2012-06-01

    Ongoing advancements in single photon emission computed tomography with on-board X-ray computed tomography (SPECT-CT) hardware and software raise important questions regarding the relative performances of various cameras and their respective image-processing software. This phantom-based study compares images produced from three state-of-the-art cameras using four image quality measurements. A thorax phantom modeling the spine, lungs, a healthy heart, and three tumors (cylindrical bottles) was scanned using the following SPECT-CT systems: Philips' Precedence (PP), GE's Infinia-Hawkeye (GH), and Siemens' Symbia-T6 (SS). For each scan, Tc-99m solutions were injected into the heart, three bottles, and thorax to yield activity concentration ratios of roughly 6:1 for both heart:thorax and tumor:thorax. The data were reconstructed using the most advanced software available on the cameras, namely, Evolution for Bone and Evolution for Cardiac (EVB and EVC, respectively), Astonish (AST), and Flash3D (FLA) for GH, PP, and SS, respectively. In addition, all sets of data were reconstructed using our in-house software. The mean values of activity error, uniformity, signal-to-noise ratio, and contrast error were used as figures of merit (FOM). No significant differences were observed for all FOM between all in-house reconstructions using PP, GH, and SS acquisition data. The mean activity error for the AST reconstruction (-24.0±1.6%) was significantly closer to the truth relative to EVB (-38.0±1.6%), EVC (-34.5±2.3%), and FLA (-33.8±1.6%). No significant differences were found between EVC and FLA for all FOM. In this phantom-based study, Philips' AST provided the most quantitatively accurate and highest contrast images, whereas Siemens' FLA and GE's EVC provided relatively higher signal-to-noise ratios and more uniform images.

  15. Puncture Initial Data and Evolution of Black Hole Binaries with High Speed and High Spin

    NASA Astrophysics Data System (ADS)

    Ruchlin, Ian

    This dissertation explores numerical models of the orbit, inspiral, and merger phases of black hole binaries. We focus on the astrophysically realistic case of black holes with nearly extremal spins, and on high energy black hole collisions. To study the evolution of such systems, we form puncture initial data by solving the four general relativity constraint equations using pseudospectral methods on a compactified collocation point domain. The solutions to these coupled, nonlinear, elliptic differential equations represent the desired configuration at an initial moment. They are then propagated forward through time using a set of hyperbolic evolution equations with the moving punctures approach in the BSSNOK and CCZ4 formalisms. To generate realistic initial data with reduced spurious gravitational wave content, the background ansatz is taken to be a conformal superposition of Schwarzschild or Kerr spatial metrics. We track the punctures during evolution, measure their horizon properties, extract the gravitational waveforms, and examine the merger remnant. These new initial data are compared with the well known Bowen-York solutions, producing up to an order of magnitude reduction in the initial unphysical gravitational radiation signature. We perform a collision from rest of two black holes with spins near to the extremal value, in a region of parameter space inaccessible to Bowen-York initial data. We simulate nonspinning black holes in quasi-circular orbits, and perform high energy head-on collisions of nonspinning black holes to estimate the magnitude of the radiated gravitational energy in the limit of infinite momentum. We also evolve spinning black holes in quasi-circular orbits with unequal masses and different spin orientations. These models provide insight into the dynamics and signals generated by compact binary systems. This is crucial to our understanding of many astrophysical phenomena, especially to the interpretation of gravitational waves, which

  16. Puncture initial data for black-hole binaries with high spins and high boosts

    NASA Astrophysics Data System (ADS)

    Ruchlin, Ian; Healy, James; Lousto, Carlos O.; Zlochower, Yosef

    2017-01-01

    We solve the Hamiltonian and momentum constraints of general relativity for two black holes with nearly extremal spins and relativistic boosts in the puncture formalism. We use a non-conformally-flat ansatz with an attenuated superposition of two Lorentz-boosted, conformally Kerr or conformally Schwarzschild 3-metrics and their corresponding extrinsic curvatures. We compare evolutions of these data with the standard Bowen-York conformally flat ansatz (technically limited to intrinsic spins χ =S /MADM2=0.928 and boosts P /MADM=0.897 ), finding, typically, an order of magnitude smaller burst of spurious radiation and agreement with inspiral and merger. As a first case study, we evolve two equal-mass black holes from rest with an initial separation of d =12 M and spins χi=Si/mi2=0.99 , compute the waveforms produced by the collision, the energy and angular momentum radiated, and the recoil of the final remnant black hole. We find that the black-hole trajectories curve at close separations, leading to the radiation of angular momentum. We also study orbiting nonspinning and moderate-spin black-hole binaries and compare these with standard Bowen-York data. We find a substantial reduction in the nonphysical initial burst of radiation which leads to cleaner waveforms. Finally, we study the case of orbiting binary black-hole systems with spin magnitude χi=0.95 in an aligned configuration and compare waveform and final remnant results with those of the SXS Collaboration [54 A. H. Mroue et al., Phys. Rev. Lett. 111, 241104 (2013)., 10.1103/PhysRevLett.111.241104], finding excellent agreement. This represents the first moving puncture evolution of orbiting and spinning black holes exceeding the Bowen-York limit. Finally, we study different choices of the initial lapse and lapse evolution equation in the moving puncture approach to improve the accuracy and efficiency of the simulations.

  17. Proton versus neutron excitations in the high-spin spectrum of 102Cd

    NASA Astrophysics Data System (ADS)

    Lieb, K. P.; Kast, D.; Jungclaus, A.; Johnstone, I. P.; de Angelis, G.; Bizzeti, P. G.; Dewald, A.; Fahlander, C.; Górska, M.; Grawe, H.; Peusquens, R.; de Poli, M.; Tiesler, H.

    The structures of the light Cd (Z = 48) isotopes are dominated by two g9/2 proton holes and several neutrons in the d5/2, g7/2, s1/2, d3/2 and/or h11/2 orbits1-5 Up to spin 8+, the even-A isotopes 100,102Cd exhibit two well separated "families" of either proton-hole or neutron-particle character, which communicate by extremely retarded E2 transitions, as small as 10-2 Wu. This implies that the configurations have rather good proton and neutron seniorities. Indeed, the magnetic dipole and electric quadrupole moments of the isomeric {8^+_1} state in 102Cd prove its π-2(99/2)proton-hole structure1 At higher spins, both proton-hole and neutron-particle pairs are broken, giving rise to magnetic dipole bands. It was the aim of the present lifetime measurements to determine absolute Ml and E2 transition strengths in this nucleus in order to test the predictions of two shell model calculations…

  18. A kinetic model for photoswitching of magnetism in the high spin molecule [Mo(IV)(CN)2(CN-Cu(II)(tren))6](ClO4)8.

    PubMed

    Raghunathan, Rajamani; Ramasesha, S; Mathonière, Corine; Marvaud, Valérie

    2008-09-21

    The heptanuclear complex [Mo(IV)(CN)2(CN-CuL)6]8+ switches from a paramagnetic dark state corresponding to six spin-1/2 Cu(II) ions to a predominantly high spin S = 3 state, on prolonged irradiation with 406 nm laser radiation at low temperature. The system returns to a paramagnetic state on warming to room temperature. The temperature dependence of the chiMT vs. T curve depends upon duration of irradiation. An earlier microscopic model showed that the excitation cross sections in different spin manifolds are similar in magnitude and that photomagnetism is not due to preferential excitation to the S = 3 state. In this paper, we attribute photomagnetism to a long lived S = 3 charge transfer excited state for which there appears to be sufficient experimental evidence. Based on this postulate, we model the photomagnetism by employing a kinetic model which includes internal conversions and intersystem crossings. The key feature of the model is the assumption of the existence of two kinds of S = 3 states: one of which has no direct pathway for internal conversion and the other characterized by slow kinetics for internal conversion to the low-energy states. The trapped S = 3 state can decay via a thermally activated barrier to the other S = 3 state. The experimental chiMT vs. T for two different irradiation times are fitted using Arrhenius dependence of the rate constants in the model.

  19. Bonding with parallel spins: high-spin clusters of monovalent metal atoms.

    PubMed

    Danovich, David; Shaik, Sason

    2014-02-18

    heteroatomic clusters should increase the bonding energy of an NPFM cluster. These NPFM clusters are excited state species. We suggest here stabilizing these states and making them accessible, for example, by using magnetic fields, or a combination of magnetic and electric fields. The advent of NPFM clusters offers new horizons in chemistry and enriches the scope of chemical bonding. These prospects form a strong incentive to investigate the origins of the bound triplet pairs and further chart the territory of NPFM clusters, for example, in clusters of Be, Mg, or Zn, possibly in clusters of their monosubstituted species, and the group III metalloids, such as B, Al, as well as in transition metals such as Sc.

  20. Exploring New Physics in Ultracold Quantum Gases: High Spin Fermions and Non-Trivial Background Manifolds

    NASA Astrophysics Data System (ADS)

    Huang, Biao

    A large portion of cold atom researches have been devoted to finding novel systems by taking advantage of the high manipulability of cold atom experiments. From the original Bose-Einstein condensates, to the recent realization of Harper-Hofstadter models, cold atoms have kept feeding the world with surprises of realizing systems that were once thought to be purely theoretical constructions. Such trend of research have propelled this thesis to seek for possible new physics based on current cold atom technologies, and to discuss its unique properties. In the first part, we will discuss the local spin ordering for systems made of large spin fermions. This is a generalization of the usual magnetic ordering for spin-1/2 systems, and we shall see that the large spin characters have made qualitative difference. Here we provide a general tensorial classification for fermionic systems of arbitrary spin, and discussed their general character and associated topological defects in the Majorana representation. We have also identified a series of highly symmetric "Platonic solid states" that are stable against perturbations, and have good chance of being observed in experiments. The second part focuses on another topic, which is the effects of background manifold on the quantum systems residing on it. We will first examine the vortex physics for Bose condensates confined on non-trivial 2D surfaces with synthetic gauge fields. In particular, we discuss in detail the cylindrical surface as an example where two types of vortices and a peculiar "necklace" pattern show up as a result of the confining geometry. Then we discuss the topic of Hall viscosity, a unique dissipationless viscosity coefficient that is related to the adiabatic change of space geometry. We relate it to the density response of a system, and therefore provide an alternative way to compute and measure such a quantity.

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

    PubMed

    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||=gz, g⊥=gx=gy) 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 bk(q) (in the Stevens notation) and the Zeeman factors gi on the spin-orbit (λ), spin-spin (ρ) coupling constant, and the ligand-field energy levels (Δi) within the (5)D multiplet. The results are presented in suitable tables and graphs. The values of λ, ρ, and Δi best describing Mn(III) ions in MnTPPCl are determined by matching the theoretical second-rank ZFSP b2(0)(D) parameter and the experimental one. The fourth-rank ZFS parameters (b4(0), b4(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.

  2. Magnetic circular dichroism studies of myoglobin, hemoglobin and peroxidase at room and low temperatures. Ferrous high spin derivatives.

    PubMed

    Sharonov, Y A; Mineyev, A P; Livshitz, M A; Sharonova, N A; Zhurkin, V B; Lysov, Y P

    1978-04-13

    The magnetic circular dichroism spectra (MCD) recorded for the visible and near-UV regions of high-spin ferrous derivatives of myoglobin, hemoglobin, hemoglobin dimers and isolated chains as well as of horseradish peroxidase at pH 6.8 and 11.4 have been compared at the room and liquid nitrogen temperatures. The MCD of the Q00- and QV-bands have been shown to be sensitive to structural differences in the heme environment of these hemoproteins. The room temperature visible MCD of native hemoglobin differs from that of myoglobin, hemoglobin dimers and isolated chains as well as from that of model pentacoordinated complex. The MCD of hemoglobin is characterized by the greater value of the MCD intensity ratio of derivative shape A-term in the Q00-band to the A-term in the QV-band. The evidneces are presented for the existence of two pH-dependent forms of ferroperoxidase, the neutral peroxidase shows the "hemoglobin-like" MCD, while the alkaline ferroperoxidase is characterized by the "myoglobin-like" MCD spectrum in the visible region. The differences in the MCD of deoxyhemoglobin and neutral ferroperoxidase as compared with other high-spin ferrous hemoproteins are considered to result from the constraints on heme group imposed by quaternary and/or tertiary protein structure. The differences between hemoporteins which are seen at the room temperature become more pronounced at liquid nitrogen temperature. Except the peak at approximately 580 nm in the MCD of deoxymyoglobin and reduced peroxidase at pH 11.4 the visible MCD does not show appreciable temperature dependent C-terms. The nature of the temperature dependent effect at approximately 580 nm is not clear. The Soret MCD of all hemoproteins studied are similar and are predominantly composed of the derivative-shaped C-terms as revealed by the increase of the MCD peaks approximately in accordance with Boltzmann distribution. The interpretation of temperature-dependent MCD observed for the Soret band has been made in

  3. Increasing Incidence of Extended-Spectrum β-Lactamase-Producing Escherichia coli in Community Hospitals throughout the Southeastern United States

    PubMed Central

    Thaden, Joshua T.; Fowler, Vance G.; Sexton, Daniel J.; Anderson, Deverick J.

    2016-01-01

    OBJECTIVE To describe the epidemiology of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-EC) and Klebsiella pneumoniae (ESBL-KP) infections DESIGN Retrospective cohort SETTING Inpatient care at community hospitals PATIENTS All patients with ESBL-EC or ESBL-KP infections METHODS ESBL-EC and ESBL-KP infections from 26 community hospitals were prospectively entered into a centralized database from January 2009 to December 2014. RESULTS A total of 925 infections caused by ESBL-EC (10.5 infections per 100,000 patient days) and 463 infections caused by ESBL-KP (5.3 infections per 100,000 patient days) were identified during 8,791,243 patient days of surveillance. The incidence of ESBL-EC infections increased from 5.28 to 10.5 patients per 100,000 patient days during the study period (P =.006). The number of community hospitals with ESBL-EC infections increased from 17 (65%) in 2009 to 20 (77%) in 2014. The median ESBL-EC infection rates among individual hospitals with ≥1 ESBL-EC infection increased from 11.1 infections/100,000 patient days (range, 2.2–33.9 days) in 2009 to 22.1 infections per 100,000 patient days (range, 0.66–134 days) in 2014 (P =.05). The incidence of ESBL-KP infections remained constant over the study period (P = .14). Community-associated and healthcare-associated ESBL-EC infections trended upward (P =.006 and P = .02, respectively), while hospital-onset infections remained stable (P = .07). ESBL-EC infections were more common in females (54% vs 44%, P < .001) and Caucasians (50% vs 40%, P < .0001), and were more likely to be isolated from the urinary tract (61% vs 52%, P < .0001) than ESBL-KP infections. CONCLUSIONS The incidence of ESBL-EC infection has increased in community hospitals throughout the southeastern United States, while the incidence of ESBL-KP infection has remained stable. Community- and healthcare-associated ESBL-EC infections are driving the upward trend. PMID:26458226

  4. Spectroscopy of exotic 123,125Ag produced in fragmentation reactions

    NASA Astrophysics Data System (ADS)

    Stefanescu, I.; Walters, W. B.; Hoteling, N.; Tomlin, B.; Mantica, P. F.; Pereira, J.; Becerril, A.; Fleckenstein, T.; Hecht, A. A.; Lorusso, G.; Quinn, M.; Pinter, J. S.; Stoker, J. B.

    2008-04-01

    We extended the experimental knowledge in the mass-region around 132Sn by identifying the decay of high-spin isomers in the exotic odd-mass 123,125Ag. The two isotopes were produced at the NSCL laboratory by projectile fragmentation of a 136Xe beam at 120MeV/u directed onto a thick Be target. The NSCL Beta Counting System, was used identify secondary beam fragments. Prompt and delayed gamma-rays following the deexcitation of the fragments were detected with the SEGA array. Partial level schemes for 123,125Ag are proposed for the first time. The observed states show single-particle characteristics, indicating strong Z=50 and N=82 shell gaps and also support the proposed weakened nucleon-nucleon interaction in this mass-region.

  5. Alkylation of a bioinspired high spin Ni(II)N3S2 complex with bifunctional reagents

    NASA Astrophysics Data System (ADS)

    Chohan, B. S.

    2013-12-01

    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, [NiC16H31N5O2S2]I2, are triclinic, sp. gr. , Z = 2. Crystals of complex 3, [NiC16H28N3O2S2]I2, are monoclinic, sp. gr. P21/ 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 N3S2O 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.

  6. Alkylation of a bioinspired high spin Ni(II)N{sub 3}S{sub 2} complex with bifunctional reagents

    SciTech Connect

    Chohan, B. S.

    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.

  7. Mesoscopic superconductivity and high spin polarization coexisting at metallic point contacts on Weyl semimetal TaAs

    PubMed Central

    Aggarwal, Leena; Gayen, Sirshendu; Das, Shekhar; Kumar, Ritesh; Süß, Vicky; Felser, Claudia; Shekhar, Chandra; Sheet, Goutam

    2017-01-01

    A Weyl semimetal is a topologically non-trivial phase of matter that hosts mass-less Weyl fermions, the particles that remained elusive for more than 80 years since their theoretical discovery. The Weyl semimetals exhibit unique transport properties and remarkably high surface spin polarization. Here we show that a mesoscopic superconducting phase with critical temperature Tc=7 K can be realized by forming metallic point contacts with silver (Ag) on single crystals of TaAs, while neither Ag nor TaAs are superconductors. Andreev reflection spectroscopy of such point contacts reveals a superconducting gap of 1.2 meV that coexists with a high transport spin polarization of 60% indicating a highly spin-polarized supercurrent flowing through the point contacts on TaAs. Therefore, apart from the discovery of a novel mesoscopic superconducting phase, our results also show that the point contacts on Weyl semimetals are potentially important for applications in spintronics. PMID:28071685

  8. Comparative EPR study on high-spin ferric porphine complexes and cytochrome P-450 having rhombic character.

    PubMed

    Sato, M; Kon, H; Kumaki, K; Nebert, D W

    1977-07-21

    Comparative EPR studies were made on two high-spin Fe(III) porphine model systems and mammalian liver microsomal cytochromes P-450, all of which exhibit approximately the same degrees of rhombicity in their EPR spectra. Comparison of g values and linewidths as a function of temperature, and of the microwave power saturation demonstrated that EPR characteristics of P-450 are more similar to the Fe(III) porphines having the thiolate axial ligand than in the other model systems, the mixed crystals of Fe(III) porphine with the corresponding free base porphine, in which no thiolate ligand is involved. There is, however, a discrepancy between P-450 and the model thiolates with respect to the size of the zero-field parameter D. These observations indicate that P-450 heme has essential structural features in common with thiolates but the Fe-S bond of P-450 may be modified from its normal orientation in model thiolates, probably as a result of the constraints imposed by the protein structure.

  9. Cassie-State Stability of Metallic Superhydrophobic Surfaces with Various Micro/Nanostructures Produced by a Femtosecond Laser.

    PubMed

    Long, Jiangyou; Pan, Lin; Fan, Peixun; Gong, Dingwei; Jiang, Dafa; Zhang, Hongjun; Li, Lin; Zhong, Minlin

    2016-02-02

    The Cassie-state stability plays a vital role in the applications of metallic superhydrophobic surfaces. Although a large number of papers have reported the superhydrophobic performance of various surface micro/nanostructures, the knowledge of which kind of micro/nanostructure contributes significantly to the Cassie-state stability especially under low temperature and pressure is still very limited. In this article, we fabricated six kinds of typical micro/nanostructures with different topography features on metal surfaces by a femtosecond laser, and these surfaces were modified by fluoroalkylsilane to generate superhydrophobicity. We then systematically studied the Cassie-state stability of these surfaces by means of condensation and evaporation experiments. The results show that some superhydrophobic surfaces, even with high contact angles and low sliding angles under normal conditions, are unstable under low temperature or external pressure. The Cassie state readily transits to a metastable state or even a Wenzel state under these conditions, which deteriorates their superhydrophobicity. Among the six micro/nanostructures, the densely distributed nanoscale structure is important for a stable Cassie state, and the closely packed micrometer-scale structure can further improve the stability. The dependence of the Cassie-state stability on the fabricated micro/nanostructures and the laser-processing parameters is also discussed. This article clarifies optimized micro/nanostructures for stable and thus more practical metallic superhydrophobic surfaces.

  10. Increasing the Transparency of Stated Choice Studies for Policy Analysis: Designing Experiments to Produce Raw Response Graphs

    ERIC Educational Resources Information Center

    Sur, Dipika; Cook, Joseph; Chatterjee, Susmita; Deen, Jacqueline; Whittington, Dale

    2007-01-01

    We believe a lack of transparency undermines both the credibility of, and interest in, stated choice studies among policy makers. Unlike articles reporting the results of contingent valuation studies, papers in the stated choice literature rarely present simple tabulations of raw response data (that is, a table or graph showing the percentage of…

  11. Increasing the Transparency of Stated Choice Studies for Policy Analysis: Designing Experiments to Produce Raw Response Graphs

    ERIC Educational Resources Information Center

    Sur, Dipika; Cook, Joseph; Chatterjee, Susmita; Deen, Jacqueline; Whittington, Dale

    2007-01-01

    We believe a lack of transparency undermines both the credibility of, and interest in, stated choice studies among policy makers. Unlike articles reporting the results of contingent valuation studies, papers in the stated choice literature rarely present simple tabulations of raw response data (that is, a table or graph showing the percentage of…

  12. U.S. Math Performance in Global Perspective: How Well Does Each State Do at Producing High-Achieving Students? PEPG Report No.: 10-19

    ERIC Educational Resources Information Center

    Hanushek, Eric A.; Peterson, Paul E.; Woessmann, Ludger

    2010-01-01

    To see how well U.S. schools do at producing high-achieving math students, the authors compare the percentage of U.S. public and private school students in the graduating Class of 2009 who were highly accomplished in mathematics in each of the 50 states and in 10 urban districts to percentages of high achievers in 56 other countries. Their…

  13. Chemical structures of swine-manure chars produced under different carbonization conditions investigated by advanced solid-state 13C nuclear magnetic resonance (NMR) spectroscopy

    USDA-ARS?s Scientific Manuscript database

    Two types of swine manure chars, hydrothermally-produced hydrochar and slow-pyrolysis pyrochar, and their raw swine manure solid were characterized using advanced 13C solid-state nuclear magnetic resonance (NMR) spectroscopy. Compared with the parent raw swine manure, both hydrochars and pyrochar di...

  14. Prevalence of CTX-M-Producing Klebsiella spp. in Broiler, Kuroiler, and Indigenous Poultry in West Bengal State, India.

    PubMed

    Mahanti, Achintya; Ghosh, Pratik; Samanta, Indranil; Joardar, Siddhartha Narayan; Bandyopadhyay, Samiran; Bhattacharyya, Debaraj; Banerjee, Jaydeep; Batabyal, Subhasis; Sar, Tapas Kumar; Dutta, Tapan Kumar

    2017-08-22

    This study was undertaken to detect the prevalence of CTX-M-producing Klebsiella spp. in healthy broiler, indigenous, and kuroiler birds reared in West Bengal (India) during November 2014-February 2015. In addition to CTX-M gene, the study was also conducted to reveal the occurrence of other β-lactamase and class I integron genes in Klebsiella spp. isolates along with their clonal relationship. A total of 321 cloacal swabs from healthy broiler, indigenous, and kuroiler birds were collected from different places of West Bengal, India. Klebsiella spp. isolation rate varies among different types of poultry birds (43.8-72.3%). In total, 33 (10.7%) Klebsiella spp. isolates were detected phenotypically as CTX-M producers and all the isolates possessed blaCTX-M in polymerase chain reaction. Whereas 17 (51.5%) and 16 (48.5%) Klebsiella spp. isolates possessed blaSHV, and blaTEM with blaCTX-M, respectively. None of the CTX-M-producing Klebsiella spp. isolates in this study possessed class I integron gene. Randomly amplified polymorphic DNA-based phylogenetic tree revealed the presence of clonal relationship among the CTX-M-producing Klebsiella spp. isolates, recovered from broilers and indigenous birds. This study identified broilers and indigenous game birds as a potential reservoir of CTX-M-producing Klebsiella spp., which could be transmitted to the human food chain directly or indirectly.

  15. High-spin structure of {sup 37}Cl, intruder excitations, and the sd-fp shell gap

    SciTech Connect

    Ionescu-Bujor, M.; Iordachescu, A.; Marginean, N.; Bucurescu, D.; Lenzi, S. M.; Bazzacco, D.; Della Vedova, F.; Farnea, E.; Menegazzo, R.; Lunardi, S.; Zilio, S.; Napoli, D. R.; De Angelis, G.; Gadea, A.; Medina, N. H.; Ur, C. A.; Otsuka, T.; Utsuno, Y.

    2009-09-15

    The structure of the N=20 nucleus {sup 37}Cl has been investigated in the {sup 24}Mg({sup 16}O,3p) reaction with a 70 MeV {sup 16}O beam. A complex level scheme extended up to an excitation energy of 17 MeV and spins (29/2{sup +}) and (27/2{sup -}) on positive and negative parity, respectively, has been established. Lifetimes for the new states have been investigated by the Doppler shift attenuation method. Large-scale shell-model calculations have been performed in a valence space involving orbitals in the sd and fp shells using the sdfp and SDPF-M effective interactions. The comparison with the experimental data indicates the need for slight changes of the sd-fp energy gaps produced by these interactions.

  16. SUSTAINABILITY OF NATURAL RUBBER-PRODUCING CROPS IN THE UNITED STATES: APPLIED BIOTECHNOLOGY LESSONS 2000-2010

    USDA-ARS?s Scientific Manuscript database

    Natural rubber (NR) is a critical and strategic raw material for industrial manufacturing and national defense. Development of a US-based supply of NR is recognized in the Critical Agricultural Materials Act, Public Law 95–592. Domestic rubber-producing crops have been introduced in the US during ti...

  17. 30 CFR 219.414 - How will MMS determine each Gulf producing State's share of the qualified OCS revenues?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ROYALTIES, RENTALS, AND BONUSES Oil and Gas, Offshore § 219.414 How will MMS determine each Gulf producing... closest distances between Alabama, Louisiana, Mississippi, and Texas and all applicable leased tracts...)) × Qualified OCS Revenues Texas Share = (ITX ÷ (IAL + ILA + IMS + ITX)) × Qualified OCS Revenues (3) If in any...

  18. Community structure of Aspergillus flavus and A. parasiticus in major almond producing areas of California, United States

    USDA-ARS?s Scientific Manuscript database

    Several nut crops including almonds, pistachios, and walnuts can become contaminated with mycotoxins. Of greatest economic significance are aflatoxins, which are mainly produced by members of Aspergillus section Flavi. The distribution of the two sclerotial-size morphotypes of A. flavus (i.e. S and ...

  19. Efficient and accurate local single reference correlation methods for high-spin open-shell molecules using pair natural orbitals

    NASA Astrophysics Data System (ADS)

    Hansen, Andreas; Liakos, Dimitrios G.; Neese, Frank

    2011-12-01

    A production level implementation of the high-spin open-shell (spin unrestricted) single reference coupled pair, quadratic configuration interaction and coupled cluster methods with up to doubly excited determinants in the framework of the local pair natural orbital (LPNO) concept is reported. This work is an extension of the closed-shell LPNO methods developed earlier [F. Neese, F. Wennmohs, and A. Hansen, J. Chem. Phys. 130, 114108 (2009), 10.1063/1.3086717; F. Neese, A. Hansen, and D. G. Liakos, J. Chem. Phys. 131, 064103 (2009), 10.1063/1.3173827]. The internal space is spanned by localized orbitals, while the external space for each electron pair is represented by a truncated PNO expansion. The laborious integral transformation associated with the large number of PNOs becomes feasible through the extensive use of density fitting (resolution of the identity (RI)) techniques. Technical complications arising for the open-shell case and the use of quasi-restricted orbitals for the construction of the reference determinant are discussed in detail. As in the closed-shell case, only three cutoff parameters control the average number of PNOs per electron pair, the size of the significant pair list, and the number of contributing auxiliary basis functions per PNO. The chosen threshold default values ensure robustness and the results of the parent canonical methods are reproduced to high accuracy. Comprehensive numerical tests on absolute and relative energies as well as timings consistently show that the outstanding performance of the LPNO methods carries over to the open-shell case with minor modifications. Finally, hyperfine couplings calculated with the variational LPNO-CEPA/1 method, for which a well-defined expectation value type density exists, indicate the great potential of the LPNO approach for the efficient calculation of molecular properties.

  20. Evidence for a high-spin Fe(IV) species in the catalytic cycle of a bacterial phenylalanine hydroxylase.

    PubMed

    Panay, Aram Joel; Lee, Michael; Krebs, Carsten; Bollinger, J Martin; Fitzpatrick, Paul F

    2011-03-22

    Phenylalanine hydroxylase is a mononuclear non-heme iron protein that uses tetrahydropterin as the source of the two electrons needed to activate dioxygen for the hydroxylation of phenylalanine to tyrosine. Rapid-quench methods have been used to analyze the mechanism of a bacterial phenylalanine hydroxylase from Chromobacterium violaceum. Mössbauer spectra of samples prepared by freeze-quenching the reaction of the enzyme-(57)Fe(II)-phenylalanine-6-methyltetrahydropterin complex with O(2) reveal the accumulation of an intermediate at short reaction times (20-100 ms). The Mössbauer parameters of the intermediate (δ = 0.28 mm/s, and |ΔE(Q)| = 1.26 mm/s) suggest that it is a high-spin Fe(IV) complex similar to those that have previously been detected in the reactions of other mononuclear Fe(II) hydroxylases, including a tetrahydropterin-dependent tyrosine hydroxylase. Analysis of the tyrosine content of acid-quenched samples from similar reactions establishes that the Fe(IV) intermediate is kinetically competent to be the hydroxylating intermediate. Similar chemical-quench analysis of a reaction allowed to proceed for several turnovers shows a burst of tyrosine formation, consistent with rate-limiting product release. All three data sets can be modeled with a mechanism in which the enzyme-substrate complex reacts with oxygen to form an Fe(IV)═O intermediate with a rate constant of 19 mM(-1) s(-1), the Fe(IV)═O intermediate hydroxylates phenylalanine with a rate constant of 42 s(-1), and rate-limiting product release occurs with a rate constant of 6 s(-1) at 5 °C.