Observation of the Cabibbo-suppressed charmed baryon decay {Lambda}{sub {ital c}}{sup +}{r_arrow}{ital p}{phi}

Energy Technology Data Exchange (ETDEWEB)

Alexander, J.P.; Bebek, C.; Berger, B.E.; Berkelman, K.; Bloom, K.; Browder, T.E.; Cassel, D.G.; Cho, H.A.; Coffman, D.M.; Crowcroft, D.S.; Dickson, M.; Drell, P.S.; Dumas, D.J.; Ehrlich, R.; Elia, R.; Gaidarev, P.; Garcia-Sciveres, M.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Henderson, S.; Jones, C.D.; Jones, S.L.; Kandaswamy, J.; Katayama, N.; Kim, P.C.; Kreinick, D.L.; Lee, T.; Liu, Y.; Ludwig, G.S.; Masui, J.; Mevissen, J.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Patterson, J.R.; Peterson, D.; Riley, D.; Soffer, A.; Avery, P.; Freyberger, A.; Lingel, K.; Prescott, C.; Rodriguez, J.; Yang, S.; Yelton, J.; Brandenburg, G.; Cinabro, D.; Liu, T.; Saulnier, M.; Wilson, R.; Yamamoto, H.; Bergfeld, T.; Eisenstein, B.I.; Ernst, J.; Gladding, G.E.; Gollin, G.D.; Palmer, M.; Selen, M.; Thaler, J.J.; Edwards, K.W.; McLean, K.W.; Ogg, M.; Bellerive, A.; Britton, D.I.; Hyatt, E.R.; Janicek, R.; MacFarlane, D.B.; Patel, P.M.; Spaan, B.; Sadoff, A.J.; Ammar, R.; Baringer, P.; Bean, A.; Besson, D.; Coppage, D.; Copty, N.; Davis, R.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, N.; Kubota, Y.; Lattery, M.; Momayezi, M.; Nelson, J.K.; Patton, S.; Poling, R.; Savinov, V.; Schrenk, S.; Wang, R.; Alam, M.S.; Kim, I.J.; Ling, Z.; Mahmood, A.H.; ONeill, J.J.; Severini, H.; Sun, C.R.; Wappler, F.; Crawford, G.; Fulton, R.; Fujino, D.; Gan, K.K.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Sung, M.; White, C.; Wolf, A.; Zoeller, M.M.; Fu, X.; Nemati, B.; Ross, W.R.; Skubic, P.; Wood, M.; Bishai, M.; Fast, J.; Gerndt, E.; Hinson, J.W.; Miao, T.; Miller, D.H.; Modesitt, M.; Shibata, E.I.; Shipsey, I.P.; Wang, P.N.; Gibbons, L.; Johnson, S.D.; Kwon, Y.; Roberts, S.; Thorndike, E.H.; Coan, T.E.; Dominick, J.; Fadeyev, V.; Korolkov, I.; Lambrecht, M.; Sanghera, S.; Shelkov, V.; Skwarnicki, T.; Stroynowski, R.; Volobouev, I.; Wei, G.; Artuso, M.; Gao, M.; Goldberg, M.; He, D.; Horwitz, N.; Kopp, S.; Moneti, G.C.; Mountain, R.; Muheim, F.; Mukhin, Y.; Playfer, S.

1996-02-01

We report the observation of the Cabibbo-suppressed decays {Lambda}{sub {ital c}}{sup +}{r_arrow}{ital pK{sup {minus}}K{sup +}} and {Lambda}{sub {ital c}}{sup +}{r_arrow}{ital p}{phi} using data collected with the CLEO II detector at CESR. The latter mode, observed for the first time with significant statistics, is of interest as a test of color suppression in charm decays. We have determined the branching ratios for these modes relative to {Lambda}{sub {ital c}}{sup +}{r_arrow}{ital pK{sup {minus}}}{pi}{sup +} and compared our results with theory. {copyright} {ital 1996 The American Physical Society.}

Multiplicity distributions from central collisions of {sup 16}O+Cu at 14.6{ital A} GeV/{ital c} and intermittency

Energy Technology Data Exchange (ETDEWEB)

Abbott, T.; Akiba, Y.; Alburger, D.; Beavis, D.; Beery, P.; Bloomer, M.A.; Bond, P.D.; Chasman, C.; Chen, Z.; Chu, Y.Y.; Cole, B.A.; Costales, J.B.; Crawford, H.J.; Cumming, J.B.; Debbe, R.; Duek, E.; Engelage, J.; Fung, S.Y.; Grodzins, L.; Gushue, S.; Hamagaki, H.; Hansen, O.; Haustein, P.; Homma, S.; Huang, H.Z.; Ikeda, Y.; Kang, J.; Katcoff, S.; Kaufman, S.; Ledoux, R.J.; Levine, M.J.; Lindstrom, P.J.; Miake, Y.; Morse, R.J.; Nagamiya, S.; Olness, J.; Parsons, C.G.; Remsberg, L.P.; Sakurai, H.; Sarabura, M.; Seto, R.; Steadman, S.G.; Stephans, G.S.F.; Sugitate, T.; Tanaka, M.; Tannenbaum, M.J.; Torikoshi, M.; van Dijk, J.H.; Videbk, F.; Vient, M.; Vincent, P.; Vulgaris, E.; Vutsadakis, V.; Watson, W.A. III; Wegner, H.E.; Woodruff, D.S.; Zajc, W.A. [Argonne National Laboratory, Argonne, Illinois 60439 (United States)]|[Brookhaven National Laboratory, Upton, New York 11973 (United States)]|[University of California, Space Sciences Laboratory, Berkeley, California 94720 (United States)]|[University of California, Riverside, California 92507 (United States)]|[Columbia University, New York, New York 10027 (United States)]|[Nevis Laboratories, Irvington, New York 10533 (United States)]|[Hiroshima University, Hiroshima 730 (Japan)]|[Institute for Nuclear Study, University of Tokyo, Tokyo 188 (Japan)]|[Kyushu University, Fukuoka 812 (Japan)]|[Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)]|[Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)]|[Department of Physics, University of Tokyo, Tokyo 113 (Japan); (The E-802 Collaboration)

1995-11-01

The E-802 Collaboration at the BNL-AGS has measured charged particle multiplicity distributions from central (ZCAL) collisions of {sup 16}O+Cu at 14.6{ital A} GeV/{ital c} as a function of the pseudorapidity interval {delta}{eta}{ge}0.1 in the range 1.2{le}{eta}{le}2.2. The fluctuations of these distributions as a function of the pseudorapidity interval have been studied by the method of normalized factorial moments and also by directly fitting the measurements to negative binomial distributions (NBD). Excellent fits to NBD were obtained in all {delta}{eta} bins, allowing, for the first time, a systematic formulation of the subject of intermittency in terms of distributions to complement the description based on normalized factorial moments. In agreement with all previous measurements of NBD fits to multiplicity distributions in hadron and lepton reactions, the {ital k} parameter of the NBD fit for central {sup 16}O+Cu collisions is found to exhibit an apparently linear increase with the {delta}{eta} interval, albeit with a much steeper slope than for other reactions, and a nonzero intercept, {ital k}(0){ne}0. The evolution of the NBD parameter {ital k}({delta}{eta}) is used to determine the two-particle short-range rapidity correlation length for central {sup 16}O+Cu collisions, {xi}=0.18{plus_minus}0.05, which is much shorter than the value {xi}{similar_to}1--3 for hadron collisions, but this is a quantitative rather than a qualitative difference. These results lead to a simple and elegant explanation of the intermittency formalism, without resort to fractals, for all reactions, which demystifies intermittency---for {sup 16}O+Cu central collisions, intermittency is nothing more than the apparent statistical independence of the multiplicity in small pseudorapidity bins, {delta}{eta}{similar_to}0.2, due to the surprisingly short two-particle rapidity correlation length.

Zinc-induced modification of the dynamical magnetic susceptibility in the superconducting state of YBa{sub 2}Cu{sub 3}O{sub 6+}{sub {ital x}} as revealed by inelastic neutron scattering

Energy Technology Data Exchange (ETDEWEB)

Sidis, Y.; Bourges, P.; Hennion, B. [Laboratoire Leon Brillouin, CEA-CNRS, Centre dEtudes de Saclay, 91191 Gif-sur-Yvette (France); Regnault, L.P. [Centre dEtudes Nucleaires de Grenoble, Departement de Recherche Fondamentale sur la Matiere Condensee, Service de Physique Statistique, Magnetisme et Supraconductivite, Groupe Magnetisme et Diffraction Neutronique, 85 X, 38041 Grenoble cedex (France); Villeneuve, R.; Collin, G. [Laboratoire Leon Brillouin, CEA-CNRS, Centre dEtudes de Saclay, 91191 Gif-sur-Yvette (France); Marucco, J.F. [Laboratoire des Composes Non-Stoechiometriques, CNRS URA 446, Batiment 415, Universite Paris Sud centre dOrsay, Orsay (France)

1996-03-01

Inelastic-neutron-scattering measurements have been performed to determine the imaginary part of the dynamical susceptibility, {chi}{double_prime}({ital Q},{omega}), of a YBa{sub 2}(Cu{sub 1{minus}{ital y}}Zn{sub {ital y}}){sub 3}O{sub 6.97} sample exhibiting a superconducting transition at {ital T}{sub {ital c}}=69 K. Zinc substitution induces striking modifications of the energy dependence of {chi}{double_prime}({ital Q},{omega}) but magnetic fluctuations remain peaked at the antiferromagnetic wave vector, {ital Q}{sub AF}, at all investigated energies. In the superconducting state of the zinc-free compound, {chi}{double_prime}({ital Q},{omega}) is restricted to a narrow energy range, {h_bar}{omega}=33{endash}47 meV, displaying a {ital spin} {ital gap} at {ital E}{sub {ital G}}=33 meV and a resonant enhancement at {ital E}{sub {tau}}=39 meV, both features vanishing upon heating up above {ital T}{sub {ital c}}. In the {ital y}=0.02 substituted sample in the superconducting state, there is still an energy band in the range 32{endash}47 meV but no clear resonance, and a signal is now observed in the low energy range, though the line shape of {chi}{double_prime}({ital Q},{omega}) indicates some reminiscence of the spin gap of the pure compound. {copyright} {ital 1996 The American Physical Society.}

Measurement of the {ovr {ital B}} {r_arrow} {ital Dl}{ovr {nu} } Partial Width and Form Factor Parameters

Energy Technology Data Exchange (ETDEWEB)

Athanas, M.; Avery, P.; Jones, C.D.; Lohner, M.; Prescott, C.; Yelton, J.; Zheng, J. [University of Florida, Gainesville, Florida 32611 (United States); Brandenburg, G.; Briere, R.A.; Ershov, A.; Gao, Y.S.; Kim, D.Y.; Wilson, R.; Yamamoto, H. [Harvard University, Cambridge, Massachusetts 02138 (United States); Browder, T.E.; Li, F.; Li, Y.; Rodriguez, J.L. [University of Hawaii at Manoa, Honolulu, Hawaii 96822 (United States); Bergfeld, T.; Eisenstein, B.I.; Ernst, J.; Gladding, G.E.; Gollin, G.D.; Hans, R.M.; Johnson, E.; Karliner, I.; Marsh, M.A.; Palmer, M.; Selen, M.; Thaler, J.J. [University of Illinois, Champaign-Urbana, Illinois 61801 (United States); Edwards, K.W.; Edwards, K.W. [the Institute of Particle Physics (Canada); Bellerive, A.; Bellerive, A.; Janicek, R.; Janicek, R.; MacFarlane, D.B.; MacFarlane, D.B.; Patel, P.M.; Patel, P.M. [the Institute of Particle Physics (Canada); Sadoff, A.J. [Ithaca College, Ithaca, New York 14850 (United States); Ammar, R.; Baringer, P.; Bean, A.; Besson, D.; Coppage, D.; Darling, C.; Davis, R.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, N. [University of Kansas, Lawrence, Kansas 66045 (United States); Anderson, S.; Kubota, Y.; Lee, S.J.; ONeill, J.J.; Patton, S.; Poling, R.; Riehle, T.; Savinov, V.; Smith, A. [University of Minnesota, Minneapolis, Minnesota 55455 (United States); Alam, M.S.; Athar, S.B.; Ling, Z.; Mahmood, A.H.; Severini, H.; Timm, S.; Wappler, F. [State University of New York at Albany, Albany, New York 12222 (United States); Anastassov, A.; Blinov, S.; Duboscq, J.E.; Fujino, D.; Gan, K.K.; Hart, T.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Spencer, M.B.; Sung, M.; Undrus, A.; Wanke, R.; Wolf, A.; Zoeller, M.M. [Ohio State University, Columbus, Ohio 43210 (United States); Nemati, B.; Richichi, S.J.; Ross, W.R.; Skubic, P. [University of Oklahoma, Norman, Oklahoma 73019 (United States); Bishai, M.; Fast, J.; Gerndt, E.; Hinson, J.W.; Menon, N.; Miller, D.H.; Shibata, E.I.; and others

1997-09-01

We have studied the decay {bar B}{r_arrow}Dl{bar {nu}} , where l=e or {mu} . From a fit to the differential decay rate d{Gamma}/dw we measure the rate normalization F{sub D}(1){vert_bar}V{sub cb}{vert_bar} and form factor slope {cflx {rho}}{sup 2}{sub D} , and, using measured values of {tau}{sub B} , find {Gamma}({bar B}{r_arrow}Dl{bar {nu}}) = (12.0{plus_minus}0.9{plus_minus}2.1) ns{sup {minus}1}. The resulting branching fractions are B({bar B}{sup 0}{r_arrow}D{sup +}l{sup {minus}}{bar {nu}})=(1.87{plus_minus}0.15{plus_minus} 0.32){percent} and B(B{sup {minus}}{r_arrow}D{sup 0} l{sup {minus}}{bar {nu}})=(1.94{plus_minus}0.15{plus_minus}0.34){percent} . The form factor parameters are in agreement with those measured in {bar B}{r_arrow}D{sup *}l{bar {nu}} decays, as predicted by heavy quark effective theory. {copyright} {ital 1997} {ital The American Physical Society}

Study of an Isospin-Forbidden $0^{+} \\rightarrow 0^{+}$ Transition in $^{38m}$K

CERN Multimedia

2002-01-01

There is at present a discrepancy between the precisely determined value of $V_{ud}^{2}$ obtained from $0^{+} \\rightarrow 0^{+} $ nuclear $\\beta$-decay and the less precisely determined value inferred from neutron decay. One possible explanation for this discrepancy involves the " Coulomb " corrections that must be applied to the nuclear decay rates. We propose to investigate one class of these corrections (for charge-dependent configuration-mixing) by measuring the isospin-forbidden $0^{+} \\rightarrow 0^{+}$ decay rate in $^{38m}$K. $^{38m}$K decay is particularly interesting because it is predicted to have the largest charge-dependent mixing correction of any of the transitions used in the $V_{ud}^{2}$ determination.

Research Institute ITAL. Association EURATOM ITAL. Annual report 1982

International Nuclear Information System (INIS)

1983-01-01

The Research Institute ITAL is one of the institutes of the Division for Agricultural Research of the Dutch Ministry of Agriculture and Fisheries. For certain aspects of its programme it is also a partner in the Association EURATOM-ITAL with the Commission of the European Community. This annual report deals with: molecular genetic methods for plant breeding; biotechnical production of valuable compounds by means of (plant) cell cultures and microorganisms; soil biology including the rhizosphere; radioactive contamination of the environment and its public health risks; the synergistic interaction between radiation and other mutagenic agents; a new approach in malaria control by means of radiation genetic research on insects; genetic sexing in the Mediterranean fruitfly, Ceratitis capitata; food irradiation (activities within the contract of the Dutch Government with the IAEA in Vienna and the FAO in Rome on food irradiation technology for developing countries). (Auth.)

Observation of Excited Charmed Baryon States Decaying to {Lambda}{sup +}{sub {ital c}}{pi}{sup +}{pi}{sup {minus}}

Energy Technology Data Exchange (ETDEWEB)

Edwards, K.W.; Ogg, M.; Bellerive, A.; Britton, D.I.; Hyatt, E.R.F.; MacFarlane, D.B.; Patel, P.M.; Spaan, B.; Sadoff, A.J.; Ammar, R.; Baringer, P.; Bean, A.; Besson, D.; Coppage, D.; Copty, N.; Davis, R.; Hancock, N.; Kelly, M.; Kotov, S.; Kravchenko, I.; Kwak, N.; Lam, H.; Kubota, Y.; Lattery, M.; Momayezi, M.; Nelson, J.K.; Patton, S.; Poling, R.; Savinov, V.; Schrenk, S.; Wang, R.; Alam, M.S.; Kim, I.J.; Ling, Z.; Mahmood, A.H.; O`Neill, J.J.; Severini, H.; Sun, C.R.; Wappler, F.; Crawford, G.; Daubenmier, C.M.; Fulton, R.; Fujino, D.; Gan, K.K.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Sung, M.; White, C.; Wolf, A.; Zoeller, M.M.; Butler, F.; Fu, X.; Nemati, B.; Ross, W.R.; Skubic, P.; Wood, M.; Bishai, M.; Fast, J.; Gerndt, E.; Hinson, J.W.; McIlwain, R.L.; Miao, T.; Miller, D.H.; Modesitt, M.; Payne, D.; Shibata, E.I.; Shipsey, I.P.J.; Wang, P.N.; Battle, M.; Ernst, J.; Gibbons, L.; Kwon, Y.; Roberts, S.; Thorndike, E.H.; Wang, C.H.; Dominick, J.; Lambrecht, M.; Sanghera, S.; Shelkov, V.; Skwarnicki, T.; Stroynowski, R.; Volobouev, I.; Wei, G.; Zadorozhny, P.; Artuso, M.; Gao, M.; Goldberg, M.; He, D.; Horwitz, N.; Moneti, G.C.; Mountain, R.; Muheim, F.; Mukhin, Y.; Playfer, S.; Rozen, Y.; Stone, S.; Xing, X.; Zhu, G.; Bartelt, J.; Csorna, S.E.; Egyed, Z.; Jain, V.; Gibaut, D.; Kinoshita, K.; Pomianowski, P.; Barish, B.; Chadha, M.; Chan, S.; Cowen, D.F.; Eigen, G.; Miller, J.S.; O`Grady, C.; Urheim, J.; Weinstein, A.J.; Athanas, M.; Brower, W.; Masek, G.; Paar, H.P.; Gronberg, J.; Korte, C.M.; Kutschke, R.; Menary, S.; Morrison, R.J.; Nakanishi, S.; Nelson, H.N.; Nelson, T.K.; Qiao, C.; Richman, J.D.; Ryd, A.; Sperka, D.; Tajima, H.; Witherell, M.S.; Procario, M.; Balest, R.; Cho, K.; Ford, W.T.; Johnson, D.R.; Lingel, K.; Lohner, M.; Rankin, P.; Smith, J.G.; Alexander, J.P.; Bebek, C.; Berkelman, K.; Bloom, K.; Browder, T.E.; Cassel, D.G.; Cho, H.A.; Coffman, D.M.; Crowcroft, D.S.; Drell, P.S.; Dumas, D.J.; Ehrlich, R.; Gaidarev, P.; (CLEO Collabora...

1995-04-24

Using data collected by the CLEO II detector, we have observed two states decaying to {Lambda}{sup +}{sub {ital c}}{pi}{sup +}{pi}{sup {minus}}. Relative to the {Lambda}{sup +}{sub {ital c}}, their mass splittings are measured to be +307.5{plus_minus}0.4{plus_minus}1.0 and +342.2{plus_minus}0.2{plus_minus}0.5MeV/{ital c}{sup 2}, respectively; this represents the first measurement of the less massive state. These two states are consistent with being orbitally excited, isospin zero {Lambda}{sup +}{sub {ital c}} states.

Observation of Two Excited Charmed Baryons Decaying into {Lambda}{sup +}{sub {ital c}}{pi}{sup {plus_minus}}

Energy Technology Data Exchange (ETDEWEB)

Brandenburg, G.; Briere, R.A.; Kim, D.Y.; Liu, T.; Saulnier, M.; Wilson, R.; Yamamoto, H. [Harvard University, Cambridge, Massachusetts 02138 (United States); Browder, T.E.; Li, F.; Li, Y.; Rodriguez, J.L. [University of Hawaii at Manoa, Honolulu, Hawaii 96822 (United States); Bergfeld, T.; Eisenstein, B.I.; Ernst, J.; Gladding, G.E.; Gollin, G.D.; Johnson, E.; Karliner, I.; Palmer, M.; Selen, M.; Thaler, J.J. [University of Illinois, Champaign-Urbana, Illinois 61801 (United States); Edwards, K.W. [Carleton University, Ottawa, Ontario, Canada K1S 5B6 and the Institute of Particle Physics (Canada); Bellerive, A.; Britton, D.I.; Janicek, R.; MacFarlane, D.B.; McLean, K.W.; Patel, P.M. [McGill University, Montreal, Quebec, Canada H3A 2T8 and the Institute of Particle Physics (Canada); Sadoff, A.J. [Ithaca College, Ithaca, New York 14850 (United States); Ammar, R.; Baringer, P.; Bean, A.; Besson, D.; Coppage, D.; Darling, C.; Davis, R.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, N. [University of Kansas, Lawrence, Kansas 66045 (United States); Anderson, S.; Kubota, Y.; Lattery, M.; ONeill, J.J.; Patton, S.; Poling, R.; Riehle, T.; Smith, A.; Savinov, V. [University of Minnesota, Minneapolis, Minnesota 55455 (United States); Alam, M.S.; Athar, S.B.; Ling, Z.; Mahmood, A.H.; Severini, H.; Timm, S.; Wappler, F. [State University of New York at Albany, Albany, New York 12222 (United States); Anastassov, A.; Blinov, S.; Duboscq, J.E.; Fulton, R.; Fujino, D.; Gan, K.K.; Hart, T.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Sung, M.; Undrus, A.; Wanke, R.; Wolf, A.; Zoeller, M.M. [Ohio State University, Columbus, Ohio 43210 (United States); Nemati, B.; Richichi, S.J.; Ross, W.R.; Skubic, P.; Wood, M. [University of Oklahoma, Norman, Oklahoma 73019 (United States); Bishai, M.; Fast, J.; Gerndt, E.; Hinson, J.W.; Miller, D.H.; Shibata, E.I.; Shipsey, I.P.; Yurko, M. [Purdue University, West Lafayette, Indiana 47907 (United States); Gibbons, L.; Johns

1997-03-01

Using data recorded by the CLEO-II detector at CESR, we report evidence of a pair of excited charmed baryons, one decaying into {Lambda}{sup +}{sub c}{pi}{sup +} and the other into {Lambda}{sup +}{sub c}{pi}{sup -}. The doubly charged state has a measured mass difference M({Lambda}{sup +}{sub c}{pi}{sup +}) -M({Lambda}{sup +}{sub c}) of 234.5{plus_minus}1.1{plus_minus}0.8 MeV/c{sup 2} and a width of 17.9{sup +3.8}{sub -3.2}{plus_minus}4.0MeV/c{sup 2}, and the neutral state has a measured mass difference M({Lambda}{sup +}{sub c}{pi}{sup -}) -M({Lambda}{sup +}{sub c}) of 232.6{plus_minus}1.0{plus_minus}0.8 MeV/c{sup 2} and a width of 13.0{sup +3.7}{sub -3.0}{plus_minus}4.0MeV/c{sup 2}. We interpret these data as evidence of the {Sigma}{sup *++}{sub c} and {Sigma}{sup *0}{sub c}, the spin (3)/(2){sup +} excitations of the {Sigma}{sub c} baryons. {copyright} {ital 1997} {ital The American Physical Society}

Ionic Diffusion in a Ternary Superionic Conductor: An {ital Ab Initio} Molecular Dynamics Study

Energy Technology Data Exchange (ETDEWEB)

Wengert, S.; Nesper, R.; Andreoni, W.; Parrinello, M. [Laboratorium fuer Anorganische Chemie, ETH Zuerich, 8092 Zuerich (Switzerland)]|[IBM Research Division, Zurich Research Laboratory, 8803 Rueschlikon (Switzerland)]|[Max-Planck-Institut fuer Festkoerperforschung, 70569 Stuttgart (Germany)

1996-12-01

We present Car-Parrinello molecular dynamics simulations of a novel superionic conductor, Li{sub 2{minus}2{ital x}}Mg{sub 1+{ital x}}Si ({ital x}{approximately}0.06), at different temperatures. The calculations clarify the nature of the ionic conduction and lead to the prediction of the first inorganic magnesium superionic conductor. In fact, both lithium and magnesium are found to act as charge carriers. The diffusion is fast and can be described as vacancy migration through directed jumps. The calculated diffusion constants for lithium are consistent with recent electrochemical measurements. {copyright} {ital 1996 The American Physical Society.}

Further Search for the Two-Photon Production of the Glueball Candidate {ital f}{sub {ital J}}(2220)

Energy Technology Data Exchange (ETDEWEB)

Alam, M.S.; Athar, S.B.; Ling, Z.; Mahmood, A.H.; Timm, S.; Wappler, F. [State University of New York at Albany, Albany, New York 12222 (United States); Anastassov, A.; Duboscq, J.E.; Gan, K.K.; Hart, T.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Schwarthoff, H.; Spencer, M.B.; Wolf, A.; Zoeller, M.M. [Ohio State University, Columbus, Ohio 43210 (United States); Richichi, S.J.; Severini, H.; Skubic, P.; Undrus, A. [University of Oklahoma, Norman, Oklahoma 73019 (United States); Bishai, M.; Fast, J.; Hinson, J.W.; Menon, N.; Miller, D.H.; Shibata, E.I.; Shipsey, I.P. [Purdue University, West Lafayette, Indiana 47907 (United States); Glenn, S.; Kwon, Y.; Lyon, A.L.; Roberts, S.; Thorndike, E.H. [University of Rochester, Rochester, New York 14627 (United States); Jessop, C.P.; Lingel, K.; Marsiske, H.; Perl, M.L.; Savinov, V.; Ugolini, D.; Zhou, X. [Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309 (United States); Coan, T.E.; Fadeyev, V.; Korolkov, I.; Maravin, Y.; Narsky, I.; Shelkov, V.; Staeck, J.; Stroynowski, R.; Volobouev, I.; Ye, J. [Southern Methodist University, Dallas, Texas 75275 (United States); Artuso, M.; Dambasuren, E.; Efimov, A.; Kopp, S.; Moneti, G.C.; Mountain, R.; Schuh, S.; Skwarnicki, T.; Stone, S.; Titov, A.; Viehhauser, G.; Wang, J.C. [Syracuse University, Syracuse, New York 13244 (United States); Bartelt, J.; Csorna, S.E.; McLean, K.W.; Marka, S. [Vanderbilt University, Nashville, Tennessee 37235 (United States); Godang, R.; Kinoshita, K.; Lai, I.C.; Pomianowski, P.; Schrenk, S. [Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States); Bonvicini, G.; Cinabro, D.; Greene, R.; Perera, L.P.; Zhou, G.J. [Wayne State University, Detroit, Michigan 48202 (United States); Chadhha, M.; Chan, S.; Eigen, G.; Miller, J.S.; Schmidtler, M.; Urheim, J.; Weinstein, A.J.; Wuerthwein, F. [California Institute of Technology, Pasadena, California 91125 (United States)

1998-10-01

The CLEO II detector at the e{sup +}e{sup {minus}} storage ring CESR has been used to search for two-photon production of the f{sub J}(2220) decaying into {pi}{sup +}{pi}{sup {minus}} . No evidence for a signal is found in 4.77 fb{sup {minus}1} of data and a 95{percent} C.L. upper limit on [{Gamma}{sub {gamma}{gamma}}B{sub {pi}{sup +}{pi}{sup {minus}}}]{sub f{sub J}( 2220)} of 2.5thinspthinspeV is set. If this result is combined with the BES Collaboration{close_quote}s measurement of f{sub J}(2220){r_arrow}{pi}{sup +}{pi}{sup {minus}} in radiative J/{psi} decay and the recent CLEO result for [{Gamma}{sub {gamma}{gamma}}B{sub K{sup 0}{sub S}K{sup 0}{sub S}}]{sub f{sub J} (2220)} , a 95{percent} C.L. lower limit on the stickiness of 102 is obtained. This result for the stickiness provides further support for a substantial neutral parton content in the f{sub J}(2220) . {copyright} {ital 1998} {ital The American Physical Society }

First Search for {ital CP} Violation in Tau Lepton Decay

Energy Technology Data Exchange (ETDEWEB)

Anderson, S.; Kubota, Y.; Lee, S.J.; ONeill, J.J.; Poling, R.; Riehle, T.; Smith, A. [University of Minnesota, Minneapolis, Minnesota 55455 (United States); Alam, M.S.; Athar, S.B.; Ling, Z.; Mahmood, A.H.; Timm, S.; Wappler, F. [State University of New York at Albany, Albany, New York 12222 (United States); Anastassov, A.; Duboscq, J.E.; Fujino, D.; Gan, K.K.; Hart, T.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Schwarthoff, H.; Spencer, M.B.; Sung, M.; Undrus, A.; Wolf, A.; Zoeller, M.M. [The Ohio State University, Columbus, Ohio 43210 (United States); Richichi, S.J.; Severini, H.; Skubic, P. [University of Oklahoma, Norman, Oklahoma 73019 (United States); Bishai, M.; Fast, J.; Hinson, J.W.; Menson, N.; Miller, D.H.; Shibata, E.I.; Shipsey, I.P.; Yurko, M. [Purdue University, West Lafayette, Indiana 47907 (United States); Glenn, S.; Kwon, Y.; Lyon, A.L.; Roberts, S.; Thorndike, E.H. [University of Rochester, Rochester, New York 14627 (United States); Jessop, C.P.; Lingel, K.; Marsiske, H.; Perl, M.L.; Savinov, V.; Ugolini, D.; Zhou, X. [Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309 (United States); Coan, T.E.; Fadeyev, V.; Korolkov, I.; Maravin, Y.; Narsky, I.; Shelkov, V.; Staeck, J.; Stroynowski, R.; Volobouev, I.; Ye, J. [Southern Methodist University, Dallas, Texas 75275 (United States); Artuso, M.; Azfar, F.; Efimov, A.; Goldberg, M.; He, D.; Kopp, S.; Moneti, G.C.; Mountain, R.; Schuh, S.; Skwarnicki, T.; Stone, S.; Viehhauser, G.; Wang, J.C.; Xing, X. [Syracuse University, Syracuse, New York 13244 (United States); Bartelt, J.; Csorna, S.E.; Jain, V.; McLean, K.W.; Marka, S. [Vanderbilt University, Nashville, Tennessee 37235 (United States); Godang, R.; Kinoshita, K.; Lai, I.C.; Pomianowski, P.; Schrenk, S. [Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States); Bonvicini, G.; Cinabro, D.; Greene, R.; Perera, L.P.; Zhou, G.J. [Wayne State Univ., (United States)

1998-11-01

We have performed the first search for CP violation in tau lepton decay. CP violation in lepton decay does not occur in the minimal standard model but can occur in extensions such as the multi-Higgs doublet model. It appears as a characteristic difference between the {tau}{sup {minus}} and {tau}{sup +} decay angular distributions for the semileptonic decay modes such as {tau}{sup {minus}}{r_arrow}K{sup 0}{pi}{sup {minus}}{nu} . We define an observable asymmetry to exploit this and find no evidence for any CP violation. {copyright} {ital 1998} {ital The American Physical Society }

Solid-State Polymerization of Acetylene under Pressure: {ital Ab Initio} Simulation

Energy Technology Data Exchange (ETDEWEB)

Bernasconi, M.; Parrinello, M. [Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstr.1, D-70569 Stuttgart (Germany); Bernasconi, M. [Istituto Nazionale Fisica della Materia and Dipartimento di Fisica, Universita di Milano, Via Celoria 16, 20133 Milano (Italy); Chiarotti, G.; Focher, P.; Tosatti, E. [Istituto Nazionale Fisica della Materia and International School for Advanced Studies, Via Beirut 4, I-34014 Trieste (Italy); Tosatti, E. [International Centre for Theoretical Physics (ICTP), P.O.Box 586, I-34014 Trieste (Italy)

1997-03-01

We have simulated by {ital ab initio} constant pressure molecular dynamics the solid-state polymerization of acetylene recently observed experimentally in the pressure range 3.5{endash}14 GPa. We have found a massive polymerization only at much higher pressure (25 GPa). However, we have also found that a triplet exciton self-trapped on a single, {ital cis}-bent molecule in crystalline acetylene is a very effective polymerization seed at lower pressure ({lt}9GPa), much closer to the experimental threshold. Therefore, we propose that the polymerization observed experimentally is possibly catalyzed by a similar seed. We predict that injection of triplet excitons would greatly enhance the polymerization rate. {copyright} {ital 1997} {ital The American Physical Society}

Pressure-induced structural and semiconductor-semiconductor transitions in C o0.5M g0.5C r2O4

Science.gov (United States)

Rahman, S.; Saqib, Hajra; Zhang, Jinbo; Errandonea, D.; Menéndez, C.; Cazorla, C.; Samanta, Sudeshna; Li, Xiaodong; Lu, Junling; Wang, Lin

2018-05-01

The effect of pressure on the structural, vibrational, and electronic properties of Mg-doped Cr bearing spinel C o0.5M g0.5C r2O4 was studied up to 55 GPa at room-temperature using x-ray diffraction, Raman spectroscopy, electrical transport measurements, and ab initio calculations. We found that the ambient-pressure phase is cubic (spinel-type, F d 3 ¯m ) and underwent a pressure-induced structural transition to a tetragonal phase (space group I 4 ¯m 2 ) above 28 GPa. The ab initio calculation confirmed this first-order phase transition. The resistivity of the sample decreased at low pressures with the existence of a low-pressure (LP) phase and started to increase with the emergence of a high-pressure (HP) phase. The temperature dependent resistivity experiments at different pressures illustrated the wide band gap semiconducting nature of both the LP and HP phases with different activation energies, suggesting a semiconductor-semiconductor transition at HP. No evidence of chemical decomposition or a semiconductor-metal transition was observed in our studies.

Quartz: structural and thermodynamic analyses across the α ↔ β transition with origin of negative thermal expansion (NTE) in β quartz and calcite

Energy Technology Data Exchange (ETDEWEB)

Antao, Sytle M.

2016-04-01

The temperature variation,<italic>T>, of the crystal structure of quartz, SiO₂, from 298 to 1235 K was obtained with synchrotron powder X-ray diffraction data and Rietveld structure refinements. The polymorphic transformation from<italic>P>3₂21 (low-<italic>T>, α quartz) to<italic>P>6₂22 (high-<italic>T>, β quartz) occurs at a transition temperature,<italic>T>_tr= 847 K. The<italic>T>variations of spontaneous strains and several structural parameters are fitted to an order parameter,<italic>Q>, using Landau theory. The change in Si atom coordinate, Si<italic>_x>, gives<italic>T_tr-T>_c= 0.49 K, which indicates an α ↔ β transition that is weakly first order and nearly tricritical in character (<italic>Q>⁴∝<italic>T>). Strains give higher<italic>T_tr-T>_cvalues (≃ 7 K). Other fitted parameters are the oxygen O<italic>_z>coordinate, Si—Si distance, Si—O—Si and φ angles, and intensity of the (111) reflection,<italic>I>₁₁₁. In α quartz, the Si—Si distance increases with<italic>T>because of cation repulsion, so the Si—O—Si angle increases (and φ decreases) and causes the thermal expansion of the framework structure that consists of corner-sharing distorted rigid SiO₄tetrahedra. The Si—Si distances contract with<italic>T>and cause negative thermal expansion (NTE) in β quartz because of increasing thermal librations of the O atom in the Si—O—Si linkage that occur nearly perpendicular to the Si—Si contraction. In calcite, CaCO₃, the short Ca—Ca distance expands with<italic>T>, but the next-nearest Ca—Ca distance, which is of equal length to theaaxis, contracts with<italic>T>and causes NTE along

Observation of Exclusive {ital B} Decays to Final States Containing a Charmed Baryon

Energy Technology Data Exchange (ETDEWEB)

Fu, X.; Nemati, B.; Richichi, S.J.; Ross, W.R.; Skubic, P.; Wood, M. [University of Oklahoma, Norman, Oklahoma 73019 (United States); Bishai, M.; Fast, J.; Gerndt, E.; Hinson, J.W.; Miao, T.; Miller, D.H.; Modesitt, M.; Shibata, E.I.; Shipsey, I.P.; Wang, P.N. [Purdue University, West Lafayette, Indiana 47907 (United States); Gibbons, L.; Johnson, S.D.; Kwon, Y.; Roberts, S.; Thorndike, E.H. [University of Rochester, Rochester, New York 14627 (United States); Jessop, C.P.; Lingel, K.; Marsiske, H.; Perl, M.L.; Schaffner, S.F.; Wang, R. [Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309 (United States); Coan, T.E.; Dominick, J.; Fadeyev, V.; Korolkov, I.; Lambrecht, M.; Sanghera, S.; Shelkov, V.; Stroynowski, R.; Volobouev, I.; Wei, G. [Southern Methodist University, Dallas, Texas 75275 (United States); Artuso, M.; Efimov, A.; Gao, M.; Goldberg, M.; He, D.; Horwitz, N.; Kopp, S.; Moneti, G.C.; Mountain, R.; Mukhin, Y.; Playfer, S.; Skwarnicki, T.; Stone, S.; Xing, X. [Syracuse University, Syracuse, New York 13244 (United States); Bartelt, J.; Csorna, S.E.; Jain, V.; Marka, S. [Vanderbilt University, Nashville, Tennessee 37235 (United States); Freyberger, A.; Gibaut, D.; Kinoshita, K.; Pomianowski, P.; Schrenk, S. [Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States); Cinabro, D. [Wayne State University, Detroit, Michigan 48202 (United States); Barish, B.; Chadha, M.; Chan, S.; Eigen, G.; Miller, J.S.; OGrady, C.; Schmidtler, M.; Urheim, J.; Weinstein, A.J.; Wuerthwein, F. [California Institute of Technology, Pasadena, California 91125 (United States); Asner, D.M.; Athanas, M.; Bliss, D.W.; Brower, W.S.; Masek, G.; Paar, H.P. [University of California, San Diego, La Jolla, California 92093 (United States); Gronberg, J.; Korte, C.M.; Kutschke, R.; Menary, S.; Morrison, R.J.; Nakanishi, S.; Nelson, H.N.; Nelson, T.K.; Qiao, C.; Richman, J.D.; Roberts, D.; Ryd, A.; and others

1997-10-01

Using data collected in the region of the {Upsilon}(4S) resonance with the CLEO-II detector, we report on the first observation of exclusive decays of the B meson to final states with a charmed baryon. We have measured the branching fractions B(B{sup {minus}}{r_arrow}{Lambda}{sup +}{sub c}{ovr p}{pi}{sup {minus}})=( 0.62{sup +0.23}{sub {minus}0.20}{plus_minus}0.11{plus_minus}0.10) {times}10{sup {minus}3} and B({ovr B}{sup 0}{r_arrow}{Lambda}{sup +}{sub c}{ovr p}{pi}{sup +}{pi}{sup {minus}})=(1.33{sup +0.46}{sub {minus}0.42}{plus_minus}0.31{plus_minus}0.21){times}10{sup {minus}3} , where the first error is statistical, the second is systematic, and the third is due to uncertainty in the {Lambda}{sup +}{sub c} branching fractions. In addition, we report upper limits for final states of the form {ovr B}{r_arrow}{Lambda}{sup +}{sub c}{ovr p} (n{pi}) and {Lambda}{sup +}{sub c}{ovr p}(n{pi}) {pi}{sup 0} , where (n{pi}) denotes up to four charged pions. {copyright} {ital 1997} {ital The American Physical Society}

Adjustment and transformation strategies of ItalPoS Permanent GNSS Network

Directory of Open Access Journals (Sweden)

Alessandro Capra

2009-06-01

Full Text Available A private network of 133 Global Navigation Satellite Systems (GNSS permanent sites, named ItalPoS (Italian
Positioning Service and uniformly covering the entire Italian territory, was established in April 2006 by the Italian
Division of Leica Geosystems S.p.A. This network also involves several GPS stations of the INGV (Italian
National Institute of Geophysics and Volcanology RING (Real-time Integrated National Gps network and GPS
stations from other public and private bodies. Indeed Leica Geosystems contributed with its experience and its
products to these networks which currently fulfil the national coverage where there are no ItalPoS stations. For
instance, the purpose of the ItalPoS network is mainly GNSS data distribution in terms of real time corrections
and RINEX files for the post-processing.
In order to compute and distribute to private and scientific users a set of adjusted coordinates of the ItalPoS network
in the IGS05 and ETRF89-2000 reference frames, a dataset of RINEX of about 120 GPS permanent sites
was created and processed, using the distributed sessions approach, by means of Gamit/Globk 10.3 GPS data
processor, also using some SOPAC (Scripps Orbits and Permanent Array Center and EUREF (European Permanent
Network solutions to improve the reference frame definition and the internal constraints.
This paper describes all the strategies adopted to estimate coordinates and velocities of the ItalPoS Network in
IGS05 and in ETRF89-2000 reference frames in the whole Italian territory.

Three dimensional [delta][ital f] simulations of beams in the SSC

Energy Technology Data Exchange (ETDEWEB)

Koga, J.; Tajima, T. (Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712-1060 (United States)); Machida, S. (SSC Laboratory, 2550 Beckleymeade Avenue, Dallas, Texas 75237 (United States))

1993-12-25

A three dimensional [delta][ital f] strong-strong algorithm has been developed to apply to the study of such effects as space charge and beam-beam interaction phenomena in the Superconducting Super Collider (SSC). The algorithm is obtained from the merging of the particle tracking code Simpsons used for 3 dimensional space charge effects and a [delta][ital f] code. The [delta][ital f] method is used to follow the evolution of the non-gaussian part of the beam distribution. The advantages of this method are twofold. First, the Simpsons code utilizes a realistic accelerator model including synchrotron oscillations and energy ramping in 6 dimensional phase space with electromagnetic fields of the beams calculated using a realistic 3 dimensional field solver. Second, the beams are evolving in the fully self-consistent strong-strong sense with finite particle fluctuation noise is greatly reduced as opposed to the weak-strong models where one beam is fixed.

Design of Nickel-Based Cation-Disordered Rock-Salt Oxides: The Effect of Transition Metal (M = V, Ti, Zr) Substitution in LiNi0.5M0.5O2 Binary Systems.

Science.gov (United States)

Cambaz, Musa Ali; Vinayan, Bhaghavathi P; Euchner, Holger; Johnsen, Rune E; Guda, Alexander A; Mazilkin, Andrey; Rusalev, Yury V; Trigub, Alexander L; Gross, Axel; Fichtner, Maximilian

2018-06-20

Cation-disordered oxides have been ignored as positive electrode material for a long time due to structurally limited lithium insertion/extraction capabilities. In this work, a case study is carried out on nickel-based cation-disordered Fm3 ̅m LiNi 0.5 M 0.5 O 2 positive electrode materials. The present investigation targets tailoring the electrochemical properties for nickel-based cation-disordered rock-salt by electronic considerations. The compositional space for binary LiM +3 O 2 with metals active for +3/+4 redox couples is extended to ternary oxides with LiA 0.5 B 0.5 O 2 with A = Ni 2+ and B = Ti 4+ , Zr 4+ , and V +4 to assess the impact of the different transition metals in the isostructural oxides. The direct synthesis of various new unknown ternary nickel-based Fm3̅ m cation-disordered rock-salt positive electrode materials is presented with a particular focus on the LiNi 0.5 V 0.5 O 2 system. This positive electrode material for Li-ion batteries displays an average voltage of ∼2.55 V and a high discharge capacity of 264 mAhg -1 corresponding to 0.94 Li. For appropriate cutoff voltages, a long cycle life is achieved. The charge compensation mechanism is probed by XANES, confirming the reversible oxidation and reduction of V 4+ /V 5+ . The enhancement in the electrochemical performances within the presented compounds stresses the importance of mixed cation-disordered transition metal oxides with different electronic configuration.

String flipped SO(10) model from [ital Z][sub 4] orbifold

Energy Technology Data Exchange (ETDEWEB)

Sato, H. (Department of Physics, Hyogo University of Education, Yashiro-cho, Hyogo 673-14 (Japan)); Shimojo, M. (Department of Electronics and Information Engineering, Fukui National College of Technology, Sabae, Fukui 916 (Japan))

1993-12-15

We search all possible string grand-unified-theory models obtained from heterotic superstrings compactified on a [ital Z][sub 4] orbifold with one Wilson line. It is shown that there is an essentially unique anomaly-free flipped SO(10) model with three generations plus one mirror conjugate generation of matter fields. We derive effective Yukawa interactions and examine the structure of mass matrices as well as a possible scenario of string coupling unification. The four-generation [ital Z][sub 4] orbifold model is a phenomenologically viable model beyond the minimal supersymmetric standard one.

Magnetic phase transition in MnFeP0.5As0.4Si0.1

International Nuclear Information System (INIS)

Wang, J L; Campbell, S J; Tegus, O; Brueck, E; Dou, S X

2010-01-01

We have carried out a detailed investigation of the magnetic phase transition in MnFeP 0.5 As 0.4 Si 0.1 . Temperature hysteresis has been observed in the variable temperature magnetization curves (B appl = 0.01 T) with T C W ∼ 302 K on warming and T C C ∼ 292 K on cooling. The first order nature of this transition in MnFeP 0.5 As 0.4 Si 0.1 is confirmed by the negative slope obtained from isotherms of M 2 versus B/M around the critical temperature. Linear thermal expansion measurements reveal a large volume change, ΔV/V∼8.7x10 -3 at the magnetic phase transition and that this magnetovolume effect is suppressed to ΔV/V ∼ 5.5x10 -3 in an applied field of B appl = 1.0 T. Analyses of 57 Fe Moessbauer spectra (4.5 - 300 K) using a random distribution model and taking nearest-neighbour environments into account, indicate that the paramagnetic and ferromagnetic phases coexist over a temperature range of ∼ 45 K around the Curie temperature. The Debye temperature for MnFeP 0.5 As 0.4 Si 0.1 has been evaluated as θ D = 350 ± 20 K from the temperature dependence of the average isomer shift.

Laser spectroscopic studies of the pure rotational U0(0) and W0(0) transitions of solid parahydrogen

International Nuclear Information System (INIS)

Chan, M.; Lee, S.S.; Okumura, M.; Oka, T.

1991-01-01

High resolution spectrum of multipole-induced transitions of solid parahydrogen was recorded using diode and difference frequency laser spectroscopy. The J=4 left-arrow 0 pure rotational U 0 (0) transition observed in the diode spectrum agrees well in frequency with the value reported by Balasubramanian et al. [Phys. Rev. Lett. 47, 1277 (1981)] but we observed a spectral width smaller by about a factor of 4. The J=6 left-arrow 0 W 0 (0) transition was observed to be exceedingly sharp, with a width of ∼70 MHz, using a difference frequency spectrometer with tone-burst modulation. This transition is composed of three components with varying relative intensity depending upon the direction of polarization of laser radiation. These components were interpreted as the splitting of the M levels in the J=6 state due to crystal field interactions. In addition, a new broad feature was found at 2452.4 cm -1 in the low resolution Fourier-transform infrared (FTIR) spectrum of solid hydrogen and was assigned to be the phonon branch W R (0) transition of the W 0 (0) line. The selection rules, crystal field splitting of J=4 and J=6 rotons, and the measured linewidth based on these observations are discussed

NGTS-1b: a hot Jupiter transiting an M-dwarf

Science.gov (United States)

Bayliss, Daniel; Gillen, Edward; Eigmüller, Philipp; McCormac, James; Alexander, Richard D.; Armstrong, David J.; Booth, Rachel S.; Bouchy, François; Burleigh, Matthew R.; Cabrera, Juan; Casewell, Sarah L.; Chaushev, Alexander; Chazelas, Bruno; Csizmadia, Szilard; Erikson, Anders; Faedi, Francesca; Foxell, Emma; Gänsicke, Boris T.; Goad, Michael R.; Grange, Andrew; Günther, Maximilian N.; Hodgkin, Simon T.; Jackman, James; Jenkins, James S.; Lambert, Gregory; Louden, Tom; Metrailler, Lionel; Moyano, Maximiliano; Pollacco, Don; Poppenhaeger, Katja; Queloz, Didier; Raddi, Roberto; Rauer, Heike; Raynard, Liam; Smith, Alexis M. S.; Soto, Maritza; Thompson, Andrew P. G.; Titz-Weider, Ruth; Udry, Stéphane; Walker, Simon R.; Watson, Christopher A.; West, Richard G.; Wheatley, Peter J.

2018-04-01

We present the discovery of NGTS-1b, a hot Jupiter transiting an early M-dwarf host (Teff,* = 3916 ^{+71}_{-63} K) in a P = 2.647 d orbit discovered as part of the Next Generation Transit Survey (NGTS). The planet has a mass of 0.812 ^{+0.066}_{-0.075} MJ, making it the most massive planet ever discovered transiting an M-dwarf. The radius of the planet is 1.33 ^{+0.61}_{-0.33} RJ. Since the transit is grazing, we determine this radius by modelling the data and placing a prior on the density from the population of known gas giant planets. NGTS-1b is the third transiting giant planet found around an M-dwarf, reinforcing the notion that close-in gas giants can form and migrate similar to the known population of hot Jupiters around solar-type stars. The host star shows no signs of activity, and the kinematics hint at the star being from the thick disc population. With a deep (2.5 per cent) transit around a K = 11.9 host, NGTS-1b will be a strong candidate to probe giant planet composition around M-dwarfs via James Webb Space Telescope transmission spectroscopy.

Structure, microstructure and determination of optical constants from transmittance data of co-doped Zn0.90Co0.05M0.05O (M=Al, Cu, Cd, Na) films

International Nuclear Information System (INIS)

2 A Laboratoire des Structures, Propriétés et Interactions Inter Atomiques, Université Abbes Laghrour, Khenchela 40000 (Algeria))" data-affiliation=" (LASPI2 A Laboratoire des Structures, Propriétés et Interactions Inter Atomiques, Université Abbes Laghrour, Khenchela 40000 (Algeria))" >Roguai, S.; 2 A Laboratoire des Structures, Propriétés et Interactions Inter Atomiques, Université Abbes Laghrour, Khenchela 40000 (Algeria))" data-affiliation=" (LASPI2 A Laboratoire des Structures, Propriétés et Interactions Inter Atomiques, Université Abbes Laghrour, Khenchela 40000 (Algeria))" >Djelloul, A.; Nouveau, Corinne; Souier, T.; Dakhel, A.A.; Bououdina, M.

2014-01-01

Highlights: • A series of Zn 0.90 Co 0.05 M 0.05 O (M=Al, Cu, Cd, Na) films has been prepared. • Thin films of these prepared samples have been deposited using USP technique. • Absorption of electronic transition has been used to fit the transmittance data. • Optical and dispersion parameters have been determined. - Abstract: ZnO, Zn 0.95 Co 0.05 O and Zn 0.90 Co 0.05 M 0.05 O (M=Al, Cd, Na, Cu) single phase films have been successfully synthesized by ultrasonic spray pyrolysis technique. Structural analysis by X-ray diffraction show that all the films have hexagonal wurtzite structure with an average crystallite size in the range of 19–25 nm. SEM analysis revealed that Cd and Na preserve the shape of nanopetals observed with ZnO or Co-ZnO films, while the doping with Al or Cu promote the formation of dense films constituted of nanorods. By the application of Levenberg–Marquardt least square method, the experimental transmittance data were fitted perfectly with the transmittance data calculated via a combination of Wemple–DiDomenico model, absorption coefficient of an electronic transition and Tauc–Urbach model. The concentration of absorbing centres N Co and oscillator strength f of d–d transition of Co 2+ ions are calculated from Smakula’s formula

Microscopic analysis of alpha scattering from sup 28 Si at 40 and 45 MeV

Energy Technology Data Exchange (ETDEWEB)

Roy, S.; Dey, T.; Goswami, A. (Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Calcutta 700064 (India)); Chintalapudi, S.N.; Banerjee, S.R. (Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Calcutta 700064 (India))

1992-06-01

Angular distributions for the elastic and inelastic alpha scattering from {sup 28}Si at {ital E}{sub {alpha}}=40 and 45 MeV are analyzed in the framework of microscopic folding model. Transition densities are calculated from improved {ital s}-{ital d} shell-model wave functions and are also compared with those extracted from inelastic electron scattering data. The density-dependent Jeukenne-Lejeune-Mahaux interaction is used, besides the M3Y interaction, in an attempt to fit the large-angle data. Fairly good agreement with the data is obtained. The extracted {ital M}{sub {ital n}}/{ital M}{sub {ital p}} value for the 2{sup +} excited state of {sup 28}Si also compares well with the shell-model prediction.

First Observations of {Upsilon}(1S) {r_arrow} {gamma}{pi}{sup +}{pi}{sup {minus}} and {Upsilon}(1S) {r_arrow} {gamma}{pi}{sup 0}{pi}{sup 0}

Energy Technology Data Exchange (ETDEWEB)

Anastassov, A.; Duboscq, J.E.; Gan, K.K.; Hart, T.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Schwarthoff, H.; Wolf, A.; Zoeller, M.M. [Ohio State University, Columbus, Ohio 43210 (United States); Richichi, S.J.; Severini, H.; Skubic, P.; Undrus, A. [University of Oklahoma, Norman, Oklahoma 73019 (United States); Bishai, M.; Chen, S.; Fast, J.; Hinson, J.W.; Menon, N.; Miller, D.H.; Shibata, E.I.; Shipsey, I.P. [Purdue University, West Lafayette, Indiana 47907 (United States); Glenn, S.; Kwon, Y.; Lyon, A.L.; Roberts, S.; Thorndike, E.H. [University of Rochester, Rochester, New York 14627 (United States); Jessop, C.P.; Lingel, K.; Marsiske, H.; Perl, M.L.; Savinov, V.; Ugolini, D.; Zhou, X. [Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309 (United States); Coan, T.E.; Fadeyev, V.; Korolkov, I.; Maravin, Y.; Narsky, I.; Stroynowski, R.; Ye, J.; Wlodek, T. [Southern Methodist University, Dallas, Texas 75275 (United States); Artuso, M.; Dambasuren, E.; Kopp, S.; Moneti, G.C.; Mountain, R.; Schuh, S.; Skwarnicki, T.; Stone, S.; Titov, A.; Viehhauser, G.; Wang, J.C. [Syracuse University, Syracuse, New York 13244 (United States); Bartelt, J.; Csorna, S.E.; McLean, K.W.; Marka, S.; Xu, Z. [Vanderbilt University, Nashville, Tennessee 37235 (United States); Godang, R.; Kinoshita, K.; Lai, I.C.; Pomianowski, P.; Schrenk, S. [Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061 (United States); Bonvicini, G.; Cinabro, D.; Greene, R.; Perera, L.P.; Zhou, G.J. [Wayne State University, Detroit, Michigan 48202 (United States); Chan, S.; Eigen, G.; Lipeles, E.; Miller, J.S.; Schmidtler, M.; Shapiro, A.; Sun, W.M.; Urheim, J.; Weinstein, A.J.; Wuerthwein, F. [California Institute of Technology, Pasadena, California 91125 (United States); Jaffe, D.E.; Masek, G.; Paar, H.P.; Potter, E.M.; Prell, S.; Sharma, V. [University of California, San Diego, La Jolla, California 92093 (United States); and others

1999-01-01

We report on a study of exclusive radiative decays of the {Upsilon}(1S) resonance collected with the CLEOthinspthinspII detector operating at the Cornell Electron Storage Ring. We present the first observation of the radiative decays {Upsilon}(1S){r_arrow}{gamma}{pi}{sup +}{pi}{sup {minus}} and {Upsilon}(1S){r_arrow}{gamma}{pi}{sup 0}{pi}{sup 0} . For the dipion mass regime m{sub {pi}{pi}}{gt}1.0 GeV , we obtain B({Upsilon}(1S){r_arrow}{gamma}{pi}{sup +}{pi}{sup {minus}})=(6.3{plus_minus}1.2{plus_minus} 1.3){times}10{sup {minus}5} and B({Upsilon}(1S){r_arrow}{gamma}{pi}{sup 0}{pi}{sup 0})=(1.7{plus_minus}0.6{plus_minus} 0.3){times}10{sup {minus}5} . {copyright} {ital 1999} {ital The American Physical Society }

Structural changes of Bi sub 1. 8 Sr sub 2 (Ca sub 1 minus x Y sub x )Cu sub 2. 2 O sub z ceramics with yttrium content studied by electron diffraction and high-resolution electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Onozuka, T.; Iwabuchi, Y.; Fukase, T. (Institute for Materials Research, Tohoku University, Sendai 980, Japan (JP)); Sato, H. (School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (USA)); Mitchell, T.E. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (USA))

1991-06-01

The mode of the incommensurate modulation in the {ital b} direction of the Bi{sub 1.8}Sr{sub 2}(Ca{sub 1{minus}{ital x}}Y{sub {ital x}})Cu{sub 2.2}O{sub {ital z}} (0.05{lt}{ital x}{lt}0.75) system is investigated by means of electron diffraction and high-resolution lattice imaging. The change of period of the long-period structure with {ital x} is found to be basically due to the mixing ratio of domains of two modulation periods with {ital b}=4.5{ital b}{sub 0} and 5{ital b}{sub 0} or 4.5{ital b}{sub 0} and 4{ital b}{sub 0}, thus creating periods of {ital b}=4.75{ital b}{sub 0--}4.0{ital b}{sub 0}. The fundamental orthorhombic lattice has dimensions of {ital a}{congruent}{ital b}{congruent}{ital b}{sub 0} (0.54 nm) and {ital c}{congruent}{ital c}{sub 0} (3.1 nm). The change of the mixing mode from one to the other mentioned above occurs just in the yttrium concentration range, 0.45{lt}{ital x}{lt}0.65, which also corresponds to the superconductor (metallic)-to-semiconductor transition boundary. The mixing modes of the domains are directly recorded as a contrast modulation with half periods, 4.5{ital b}{sub 0}/2 and 5{ital b}{sub 0}/2 or 4.5{ital b}{sub 0}/2 and 4{ital b}{sub 0}/2 in high-resolution lattice images. These images are reproduced well by a multislice computer-simulation technique.

Spin dynamics in CuO and Cu[sub 1[minus][ital x

Energy Technology Data Exchange (ETDEWEB)

Carretta, P.; Corti, M.; Rigamonti, A. (Department of Physics Alessandro Volta,' ' University of Pavia, Via Bassi 6, 27100 Pavia (Italy))

1993-08-01

[sup 63]Cu nuclear quadrupole resonance (NQR), nuclear antiferromagnetic resonance (AFNMR), and spin-lattice relaxation, as well as [sup 7]Li NMR and relaxation measurements in CuO and in Cu[sub 1[minus][ital x

Structural and superconducting properties of oxygen-deficient NdBa sub 2 Cu sub 3 O sub 7 minus. delta

Energy Technology Data Exchange (ETDEWEB)

Shaked, H. (Nuclear Research Center-Negev, Post Office Box 9001, Beer Sheva, Israel (IL) Ben Gurion University of the Negev, Post Office Box 653, Beer Sheva, Israel (IL)); Veal, B.W.; Faber, J. Jr.; Hitterman, R.L.; Balachandran, U.; Tomlins, G.; Shi, H.; Morss, L.; Paulikas, A.P. (Argonne National Laboratory, Argonne, Illinois 60439 (USA))

1990-03-01

Neutron diffraction was used to determine the structural properties of oxygen deficient NdBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} for 0.09{lt}{delta}{lt}0.74. It was found that superconductivity disappears at the orthorhombic-to-tetragonal phase transition which occurs at {delta}{sub {ital O}{ital T}}=0.45. Structural parameters vary smoothly with {delta} but exhibit a change in slope at the orthorhombic-to-tetragonal transition. The structural properties exhibit the same features found in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} where {delta}{sub {ital O}{ital T}}=0.65. It is shown that the repulsion energy of oxygen atoms in the O(1) and O(5) sites in NdBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} is smaller than in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}. This lower repulsion energy stabilizes the orthorhombic phase at lower values of {delta}. It is argued that the disappearance of superconductivity at the orthorhombic-to-tetragonal transition is an inherent property of the {ital R}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} ({ital R} denotes rare earth) system.

A Brillouin scattering study of La0.77Ca0.23MnO3 across the metal-insulator transition

International Nuclear Information System (INIS)

Seikh, Md Motin; Narayana, Chandrabhas; Sudheendra, L; Sood, A K; Rao, C N R

2004-01-01

Temperature-dependent Brillouin scattering studies have been carried out on La 0.77 Ca 0.23 MnO 3 across the paramagnetic insulator-ferromagnetic metal (I-M) transition (T C ∼ 230 K). The spectra show modes corresponding to a surface Rayleigh wave (SRW) and a high velocity pseudo-surface wave (HVPSAW) along with bulk acoustic waves (B1 and B2). The Brillouin shifts associated with the SRW and HVPSAW increase, whereas the B1 and B2 frequencies decrease, below T C . The temperature dependence of the SRW and HVPSAW modes is related to the increase in the elastic constant C 11 across the I-M transition. The decrease in frequency across the I-M transition of the bulk modes is understood to be due to enhanced self-energy corrections as a result of increased magnon-phonon interaction across the I-M transition. Correspondingly, these modes show a large increase in the full width at half maximum (FWHM) as the temperature decreases. We also observe a central peak whose width is maximum at T C

Pressure induced insulator–metal transition and giant negative piezoresistance in Pr{sub 0.6}Ca{sub 0.4}Mn{sub 0.96}Al{sub 0.04}O{sub 3} polycrystal

Energy Technology Data Exchange (ETDEWEB)

Arumugam, S., E-mail: sarumugam1963@yahoo.com [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirapalli 620024, Tamil Nadu (India); Thiyagarajan, R. [Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203 (China); Kalaiselvan, G.; Sivaprakash, P. [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirapalli 620024, Tamil Nadu (India)

2016-11-01

The effect of external hydrostatic pressure (P) on the magnetization (M) and resistivity (ρ) properties of charge-orbital (CO) ordered-insulating phase-separated manganite Pr{sub 0.6}Ca{sub 0.4}Mn{sub 0.96}Al{sub 0.04}O{sub 3} system is reported here. At ambient P, CO ordering transition and spin-canting in the AFM are observed at 223 K and 55 K respectively in M(T) and ρ(T) measurements. Application of P increases simultaneously the magnitude of magnetization (M) and transition temperature, and weakens the CO ordering in M(T) measurements up to 0.98 GPa. During ρ(T) measurements, P induces an insulator–metallic transition (T{sub IM}) at 1.02 GPa, and further increase of P up to 2.84 GPa leads to increase of T{sub IM} (dT{sub IM}/dP =21.6 K/GPa). ρ at T{sub IM} is reduced about three orders of magnitude at 2.84 GPa, and leads to the giant negative piezoresistance (~98%). These results are analyzed separately in two temperature regions i.e., below and above T{sub IM} by power function equation and small polaronic hopping model respectively. It is understood from these analyses that the application of P suppresses the Jahn–Teller distortions, electron–electron and electron–magnon scattering factors, and induces the insulator–metal transition in Pr{sub 0.6}Ca{sub 0.4}Mn{sub 0.96}Al{sub 0.04}O{sub 3} system. - Highlights: • Application of P on Pr{sub 0.6}Ca{sub 0.4}Mn{sub 0.96}Al{sub 0.04}O{sub 3} reduces resistivity (ρ) remarkably at low-temperatures, and exhibits an insulator to metallic transition at 1.02 GPa. • The reduction in ρ by P is about three orders of magnitude at 2.84 GPa, leads to the giant negative piezoresistance about 98%. • The effect of the suppression of Jahn–Teller distortions, electron–electron and electron–magnon scattering under an applied P exhibits to the metal-Insulator transition. • The phase-separation in this system has been tuned by both internal and external perturbations.

Spin canting and magnetic transition in NixZn1-xFe2O4 (x=0.0, 0.5 and 1.0) nanoparticles

Science.gov (United States)

Rani, Stuti; Raghav, Dharmendra Singh; Yadav, Prashant; Varma, G. D.

2018-04-01

Nanoparticles of NixZn1-xFe2O4(x=0.0, 0.5 and 1.0) have been synthesized via co-precipitation method and studied thestructural and magnetic properties. Rietveld refinement of X ray diffraction data of as synthesized samples revealthat the samples have mixed spinel structure with space group Fd-3m. The lattice parameter of the samples decreases as doping concentration of Ni ions increases. Magnetic measurements show paramagnetic to ferrimagnetic transition at room temperature on Ni doping in ZnFe2O4 nanoparticles. The magnetic measurements also show spin canting in samples possibly due to their nanocrystalline nature. The spin canting angles have been calculated with the help of Yafet-Kittel (Y-K) model. Furthermore, the Law of approach (LA) fitting of M-H curves indicates that the samples are highly anisotropicin nature. The Arrot plots of as synthesized samples also indicate the paramagnetic to ferrimagnetic transition. The correlation between the structural and observed magnetic properties of NixZn1-xFe2O4(x=0.0, 0.5 and 1.0) nanocrystals will be described and discussed in this paper.

E2 and M1 Transition Probabilities in Odd Mass Hg Nuclei

Energy Technology Data Exchange (ETDEWEB)

Berg, V; Baecklin, A; Fogelberg, B; Malmskog, S G

1969-10-15

L- and M-subshell ratios have been measured for the 39.5 keV transition in {sup 193}Hg and the 37.1 and 16.2 keV transitions in {sup 195}Hg yielding 0.38 {+-} 0.12 , <0.02 and 0.08 {+-} 0.03 per cent E2, respectively. The half-lives of the 39.5 keV level in {sup 193}Hg and the 53.3 and 37.1 keV levels in {sup 195}Hg have been measured by the delayed coincidence method, yielding values of 0.63 {+-} 0.03, 0.72 {+-} 0.03 and <0.05 nsec respectively. A systematic compilation of reduced E2 and M1 transition probabilities in odd mass Pt, Hg and Pb nuclei is given and compared to theoretical predictions.

PHYSICAL PROPERTIES OF THE 0.94-DAY PERIOD TRANSITING PLANETARY SYSTEM WASP-18

International Nuclear Information System (INIS)

Southworth, John; Anderson, D. R.; Maxted, P. F. L.; Hinse, T. C.; Dominik, M.; Mathiasen, M.; Browne, P.; Glitrup, M.; Joergensen, U. G.; Harpsoee, K.; Liebig, C.; Maier, G.; Bozza, V.; Calchi Novati, S.; Mancini, L.; Burgdorf, M.; Dreizler, S.; Hessman, F.; Hundertmark, M.; Finet, F.

2009-01-01

We present high-precision photometry of five consecutive transits of WASP-18, an extrasolar planetary system with one of the shortest orbital periods known. Through the use of telescope defocusing we achieve a photometric precision of 0.47-0.83 mmag per observation over complete transit events. The data are analyzed using the JKTEBOP code and three different sets of stellar evolutionary models. We find the mass and radius of the planet to be M b = 10.43 ± 0.30 ± 0.24 M Jup and R b = 1.165 ± 0.055 ± 0.014 R Jup (statistical and systematic errors), respectively. The systematic errors in the orbital separation and the stellar and planetary masses, arising from the use of theoretical predictions, are of a similar size to the statistical errors and set a limit on our understanding of the WASP-18 system. We point out that seven of the nine known massive transiting planets (M b > 3 M Jup ) have eccentric orbits, whereas significant orbital eccentricity has been detected for only four of the 46 less-massive planets. This may indicate that there are two different populations of transiting planets, but could also be explained by observational biases. Further radial velocity observations of low-mass planets will make it possible to choose between these two scenarios.

Epitaxial growth of YBa sub 2 Cu sub 3 O sub 7 minus. delta. thin films on LiNbO sub 3 substrates

Energy Technology Data Exchange (ETDEWEB)

Lee, S.G.; Koren, G.; Gupta, A.; Segmuller, A.; Chi, C.C. (IBM Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (US))

1989-09-18

{ital In} {ital situ} epitaxial growth of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} thin films on {ital Y}-cut LiNbO{sub 3} substrates using a standard laser ablation technique is reported. Resistance of the films shows a normal metallic behavior and a very sharp ({lt}1 K) superconducting transition with {ital T}{sub {ital c}}({ital R}=0) of 92 K. High critical current density of {ital J}{sub {ital c}}(77 K)=2{times}10{sup 5} A/cm{sup 2} is observed, which is in accordance with epitaxial growth. Film orientation observed from x-ray diffraction spectra indicates that the {ital c} axis is normal to the substrate plane and the {ital a} axis is at 45{degree} to the (11.0) direction of the hexagonal lattice of the substrate with two domains in mirror image to the (110) plane.

Gross and Fine Structure of Pion Production Excitation Functions in {bold {ital p}}-Nucleus and Nucleus-Nucleus Reactions

Energy Technology Data Exchange (ETDEWEB)

Jakobsson, B.; Berg, M.; Carlen, L.; Elmer, R.; Fokin, A.; Ghetti, R.; Martensson, J.; Noren, B.; Oskarsson, A.; Whitlow, H.J. [Department of Physics, University of Lund, Lund (Sweden); Ekstroem, C.; Ericsson, G.; Romanski, J.; van Veldhuizen, E.J.; Westerberg, L. [The Svedberg Laboratory and Department of Neutron Physics, University of Uppsala, Uppsala (Sweden); Julien, J. [Centre d`Etudes Nucleaires, Saclay (France); Skeppstedt, O. [Department of Physics, Chalmers Institute of Technology, Gothenburg (Sweden); Nyboe, K.; Thorsteinsen, T.F.; Amirelmi, S. [Department of Physics, University of Bergen, Bergen (Norway); Guttormsen, M.; Lo/vho/iden, G. [Department of Physics, University of Oslo, Oslo (Norway); Bellini, V.; Palazzolo, F.; Sperduto, M.L. [Istituto Nazionale di Fisica Nucleare/Laboratorio Nazionale del Sud, University of Catania, Catania (Italy); Bondorf, J.P.; Mishustin, I. [Niels Bohr Institute, Copenhagen (Denmark); Avdeichikov, V. [Joint Institute for Nuclear Research, Dubna (Russia); Lozhkin, O.V.; Murin, Y. [V.G. Khlopin Radium Institute, St.Petersburg (Russia)

1997-05-01

Slow ramping of the CELSIUS storage ring has been utilized to measure the yield of charged pions in proton and heavy ion induced collisions with continuously varying beam energy. Boltzmann-Uehling-Uhlenbeck predictions, including Fermi momenta of nucleons in nuclei, follow the general shape of the p-nucleus excitation functions quite well except for a general overestimation of the backward emission. For heavy ion reactions the calculated yield also falls off faster with decreasing beam energy than the data. No statistically significant narrow resonances are observed. {copyright} {ital 1997} {ital The American Physical Society}

Order-disorder transition and electrical conductivity of the brownmillerite solid-solutions system Ba2(In, M)2O5 (M=Ga, Al)

International Nuclear Information System (INIS)

Yamamura, Hiroshi; Hamazaki, Hirohumi; Kakinuma, Katsuyoshi; Mori, Toshiyuki; Haneda, Hajime

1999-01-01

The brownmillerite solid-solution systems Ba 2 (In 1-x M x ) 2 O 5 (M=Ga, Al) were investigated by means of high-temperature X-ray diffraction (XRD), dilatometry, and electrical-conductivity measurements. XRD showed that the Ba 2 (In 1-x Ga x ) 2 O 5 system had orthorhombic symmetry in the composition range 0.0≤x≤0.2 and cubic symmetry in the range 0.3≤x. The Al system also changed to cubic symmetry from orthorhombic symmetry in the range 0.2≤x. While the orthorhombic phase showed an order-disorder transition in the electrical conductivity measurements, the transition temperature decreased with increasing the M content. The order-disorder transition temperature and the crystal-structure transition temperature were very different. Such a transition was not observed in the cubic phases, and their electrical conductivity were fairly low compared to those of the disordered cubic phase after the transition due to the heating process. These phenomena are discussed in terms of disordering of the tetrahedral site in the brownmillerite structure, which is occupied by the smaller Ga 3+ or Al 3+ rather than ny In 3+

Efeito e modo de ação das bacteriocinas produzidas por Lactococcus lactis subsp. lactis ITAL 383, ATCC 11454 e CNRZ 150 contra Listeria innocua LIN 11 Effect and mode of action of the bacterioncin produced by Lactococcus. lactis subsp. lactis ITAL 383, ATCC 11454 e CNRZ 150 against Listeria innocua LIN 11

Directory of Open Access Journals (Sweden)

Izildinha MORENO

1999-01-01

Full Text Available O efeito e o modo de ação das bacteriocinas produzidas por L. lactis subsp. lactis ITAL 383 e CNRZ 150 são similares à nisina de L. lactis subsp. lactis ATCC 11454. Estas bacteriocinas apresentaram um modo de ação bactericida, causando a lise de células de L. innocua LIN 11, associada ao decréscimo da absorbância e da viabilidade celular. O efeito letal foi maior para células em fase exponencial comparativamente à fase estacionária de crescimento. A adsorção dessas bacteriocinas às células de L. innocua LIN 11 foi muito rápida e influenciada pelo pH do meio de suspensão; adsorção máxima foi verificada a pH 6,0 e logo após o contato inicial. Perda completa de adsorção ocorreu em pH 2,0.The effect and mode of action of the bacteriocin produced by L. lactis subsp. lactis ITAL 383 and CNRZ 150 are similar to the nisin produced by L. lactis subsp. lactis ATCC 11454. It was clearly bactericidal, and caused lysis of a strain of L. innocua LIN 11 detected by the decrease of absorbance values and the cell viability. Their lethal effect was considerably higher during the logarithmic growth when compared to the stationary phase. Adsorption developed rapidly and was influenced by the pH value of the suspension medium. Maximum adsorption was observed at pH 6,0 and immediately after initial contact and loss at pH 2,0.

Italic Typography and Wordsworth's Later Sonnets as Visual Poetry

DEFF Research Database (Denmark)

Simonsen, Peter

2007-01-01

  The later Wordsworth understood the sonnet as a form of visual poetry. The essay investigates this in relation to Wordsworth's sense of layout in his 1838 book of sonnets, his conceptualization of the sonnet as "picture," "frame," and "monument," and his use of italic typeface in printings...... of the sonnet "After-Thought" after 1827. The positive sense of the visual thus articulated by the later poet constitutes one way in which he swerves from his earlier self, and, the essay argues in contrast to traditional readings of the career, enriches even as it complicates our understanding of his work....

First-principles study of hydrogen dissociation and diffusion on transition metal-doped Mg(0 0 0 1) surfaces

International Nuclear Information System (INIS)

Wang, Zhiwen; Guo, Xinjun; Wu, Mingyi; Sun, Qiang; Jia, Yu

2014-01-01

First-principles calculations within the density functional theory (DFT) have been carried out to study hydrogen molecules dissociation and diffusion on clean and transition metals (TMs) doped Mg(0 0 0 1) surfaces following Pozzo et al. work. Firstly, the stability of Mg(0 0 0 1) surface doped with transition metals atom has been studied. The results showed that transition metals on the left of the table tend to substitute Mg in the second layer, while the other transition metals prefer to substitute Mg in the first layer. Secondly, we studied hydrogen molecules dissociation and diffusion on clean and Mg(0 0 0 1) surfaces which the transition metal atoms substituted both in the first layer and second layer. When transition metal atoms substitute in the first layer, the results agree with the Pozzo et al. result; when transition metal atoms substitute in the second layer, the results showed that the transition metals on the left of the periodic table impact on the dissociation barriers is less. However, for the transition metals (Mn, Fe, Co, Ni) on the right, there is a great impact on the barriers. The transition metals doped surfaces bind the dissociated H atoms loosely, making them easily diffused. The results further reveal that the Fe dopant on the Mg surface is the best choice for H 2 dissociation and hydrogen storage.

Investigation on maximum transition temperature of phonon mediated superconductivity

Energy Technology Data Exchange (ETDEWEB)

Fusui, L; Yi, S; Yinlong, S [Physics Department, Beijing University (CN)

1989-05-01

Three model effective phonon spectra are proposed to get plots of {ital T}{sub {ital c}}-{omega} adn {lambda}-{omega}. It can be concluded that there is no maximum limit of {ital T}{sub {ital c}} in phonon mediated superconductivity for reasonable values of {lambda}. The importance of high frequency LO phonon is also emphasized. Some discussions on high {ital T}{sub {ital c}} are given.

Order-disorder transition and electrical conductivity of the brownmillerite solid-solutions system Ba sub 2 (In, M) sub 2 O sub 5 (M=Ga, Al)

CERN Document Server

Yamamura, H; Kakinuma, K; Mori, T; Haneda, H

1999-01-01

The brownmillerite solid-solution systems Ba sub 2 (In sub 1 sub - sub x M sub x) sub 2 O sub 5 (M=Ga, Al) were investigated by means of high-temperature X-ray diffraction (XRD), dilatometry, and electrical-conductivity measurements. XRD showed that the Ba sub 2 (In sub 1 sub - sub x Ga sub x) sub 2 O sub 5 system had orthorhombic symmetry in the composition range 0.0<=x<=0.2 and cubic symmetry in the range 0.3<=x. The Al system also changed to cubic symmetry from orthorhombic symmetry in the range 0.2<=x. While the orthorhombic phase showed an order-disorder transition in the electrical conductivity measurements, the transition temperature decreased with increasing the M content. The order-disorder transition temperature and the crystal-structure transition temperature were very different. Such a transition was not observed in the cubic phases, and their electrical conductivity were fairly low compared to those of the disordered cubic phase after the transition due to the heating process. These p...

Influence of intermartensitic transitions on transport properties of Ni$_{2.16}Mn_{0.84}$Ga alloy

CERN Document Server

Khovailo, V V; Wedel, C; Takagi, T; Abe, T; Sugiyama, K

2004-01-01

Magnetic, transport, and x-ray diffraction measurements of ferromagnetic shape memory alloy Ni$_{2.16}$Mn$_{0.84}$Ga revealed that this alloy undergoes an intermartensitic transition upon cooling, whereas no such a transition is observed upon subsequent heating. The difference in the modulation of the martensite forming upon cooling from the high-temperature austenitic state [5-layered (5M) martensite], and the martensite forming upon the intermartensitic transition [7-layered (7M) martensite] strongly affects the magnetic and transport properties of the alloy and results in a large thermal hysteresis of the resistivity $\\rho$ and magnetization $M$. The intermartensitic transition has an especially marked influence on the transport properties, as is evident from a large difference in the resistivity of the 5M and 7M martensite, $(\\rho_{\\mathrm{5M}} - \\rho_{\\mathrm{7M}})/\\rho _{\\mathrm{5M}} \\approx 15%$, which is larger than the jump of resistivity at the martensitic transition from the cubic austenitic phase ...

Analysis of Spo0M function in Bacillus subtilis.

Directory of Open Access Journals (Sweden)

Luz Adriana Vega-Cabrera

Full Text Available Spo0M has been previously reported as a regulator of sporulation in Bacillus subtilis; however, little is known about the mechanisms through which it participates in sporulation, and there is no information to date that relates this protein to other processes in the bacterium. In this work we present evidence from proteomic, protein-protein interaction, morphological, subcellular localization microscopy and bioinformatics studies which indicate that Spo0M function is not necessarily restricted to sporulation, and point towards its involvement in other stages of the vegetative life cycle. In the current study, we provide evidence that Spo0M interacts with cytoskeletal proteins involved in cell division, which suggest a function additional to that previously described in sporulation. Spo0M expression is not restricted to the transition phase or sporulation; rather, its expression begins during the early stages of growth and Spo0M localization in B. subtilis depends on the bacterial life cycle and could be related to an additional proposed function. This is supported by our discovery of homologs in a broad distribution of bacterial genera, even in non-sporulating species. Our work paves the way for re-evaluation of the role of Spo0M in bacterial cell.

Measurement of the mass splittings between the b{bar b}{chi}{sub b,J}(1P) states

Energy Technology Data Exchange (ETDEWEB)

Edwards, K.W.; Edwards, K.W. [Institute of Particle Physics (Canada); Bellerive, A.; Bellerive, A.; Janicek, R.; Janicek, R.; MacFarlane, D.B.; MacFarlane, D.B.; Patel, P.M.; Patel, P.M. [Institute of Particle Physics (Canada); Sadoff, A.J. [Ithaca College, Ithaca, New York,14850 (United States); Ammar, R.; Baringer, P.; Bean, A.; Besson, D.; Coppage, D.; Darling, C.; Davis, R.; Kotov, S.; Kravchenko, I.; Kwak, N.; Zhou, L. [University of Kansas, Lawrence, Kansas, 66045 (United States); Anderson, S.; Kubota, Y.; Lee, S.J.; ONeill, J.J.; Poling, R.; Riehle, T.; Smith, A. [University of Minnesota, Minneapolis, Minnesota, 55455 (United States); Alam, M.S.; Athar, S.B.; Ling, Z.; Mahmood, A.H.; Timm, S.; Wappler, F. [State University of New York at Albany, Albany, New York, 12222 (United States); Anastassov, A.; Duboscq, J.E.; Fujino, D.; Gan, K.K.; Hart, T.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Schwarthoff, H.; Spencer, M.B.; Sung, M.; Undrus, A.; Wolf, A.; Zoeller, M.M. [Ohio State University, Columbus, Ohio, 43210 (United States); Richichi, S.J.; Severini, H.; Skubic, P. [University of Oklahoma, Norman, Oklahoma, 73019 (United States); Bishai, M.; Fast, J.; Hinson, J.W.; Menon, N.; Miller, D.H.; Shibata, E.I.; Shipsey, I.P.; Yurko, M. [Purdue University, West Lafayette, Indiana, 47907 (United States); Glenn, S.; Kwon, Y.; Lyon, A.L.; Roberts, S.; Thorndike, E.H. [University of Rochester, Rochester, New York, 14627 (United States); Jessop, C.P.; Lingel, K.; Marsiske, H.; Perl, M.L.; Savinov, V.; Ugolini, D.; Zhou, X. [Stanford Linear Accelerator Center, Stanford University, Stanford, California, 94309 (United States); Coan, T.E.; Fadeyev, V.; Korolkov, I.; Maravin, Y.; Narsky, I.; Shelkov, V.; Staeck, J.; Stroynowski, R.; Volobouev, I.; Ye, J. [Southern Methodist University, Dallas, Texas, 75275 (United States); Artuso, M.; Azfar, F.; Efimov, A.; Goldberg, M.; He, D.; Kopp, S.; Moneti, G.C.; Mountain, R.; Schuh, S.; Skwarnicki, T.; and others

1999-02-01

We present new measurements of photon energies and branching fractions for the radiative transitions {Upsilon}(2S){r_arrow}{gamma}{chi}{sub b(J=0,1,2)}(1P). The masses of the {chi}{sub b} states are determined from the measured radiative photon energies. The ratio of mass splittings between the {chi}{sub b} substates, r{equivalent_to}(M{sub J=2}{minus}M{sub J=1})/(M{sub J=1}{minus}M{sub J=0}), with M the {chi}{sub b} mass, provides information on the nature of the b{bar b} confining potential. We find r(1P)=0.542{plus_minus}0.022{plus_minus}0.024. This value is somewhat lower than the previous world average, but more consistent with the theoretical expectation that r(1P){lt}r(2P); i.e., that this mass splitting ratio is smaller for the {chi}{sub b}(1P) states than for the {chi}{sub b}(2P) states. {copyright} {ital 1999} {ital The American Physical Society}

Glass transition behavior and crystallization kinetics of Cu0.3(SSe20)0.7 chalcogenide glass

International Nuclear Information System (INIS)

Soliman, A.A.

2005-01-01

The glass transition behavior and crystallization kinetics of Cu 0.3 (SSe 20 ) 0.7 chalcogenide glass were investigated using differential scanning calorimetry (DSC), X-ray diffraction (XRD). Two crystalline phases (SSe 20 and Cu 2 Se) were identified after annealing the glass at 773 K for 24 h. The activation energy of the glass transition (E g ), the activation energy of crystallization (E c ), the Avrami exponent (n) and the dimensionality of growth (m) were determined. Results indicate that this glass crystallizes by a two-stage bulk crystallization process upon heating. The first transformation, in which SSe 20 precipitates from the amorphous matrix with a three-dimensional crystal growth. The second transformation, in which the residual amorphous phase transforms into Cu 2 Se compound with a two-dimensional crystal growth

M1-transitions in the MIT bag model

International Nuclear Information System (INIS)

Hackman, R.H.; Deshpande, N.G.; Dicus, D.A.; Teplitz, V.L.

1977-03-01

In the MIT bag model, the M1-transitions of low lying hadrons are investigated. The following calculations are performed: 32 hadron masses are recomputed with a choice of bag parameters designed to give the correct values for the proton magnetic moment, μ/sub p/, and several masses, M/sub rho/ M/sub ω/ M/sub Δ/ M/sub Ω/, and M/sub D/; (2) eta, eta', eta/sub c/ mixing is computed in an untrustworthy approximation; and the widths for 38 M1-transitions are computed

Cold Spring Harbor symposia on quantitative biology: Volume 51, Molecular biology of /ital Homo sapiens/

International Nuclear Information System (INIS)

1986-01-01

This volume is the second part of a collection of papers submitted by the participants to the 1986 Cold Spring Harbor Symposium on Quantitative Biology entitled Molecular Biology of /ital Homo sapiens/. The 49 papers included in this volume are grouped by subject into receptors, human cancer genes, and gene therapy. (DT)

M1 transitions between superdeformed states in 195Tl

International Nuclear Information System (INIS)

Zheng Xing; Xingqu Chen; Xiaochun Wang

1996-01-01

Using a triaxial-particle-rotor model, the quadrupole and dipole transition energies, kinematic and dynamic moments of inertia, electromagnetic transition probabilities and the relative intensity of the E2 γ-transitions are calculated for superdeformed bands in 195 Tl. A strong perturbation effect of rotation on transition energies and M1 and E2 transitions of superdeformed states is investigated. The total M1 transitions, enhanced by internal conversion, are expected to compete strongly with the E2 γ-ray at low spins in the superdeformed 195 Tl nucleus. (author)

On the high temperature phase transition in Ba(Zr0.20Ti0.80O3 ceramic

Directory of Open Access Journals (Sweden)

K. P. Chandra

2017-08-01

Full Text Available Temperature dependent X-ray diffraction (XRD and dielectric properties of perovskite Ba(Zr0.2Ti0.8O3 ceramic prepared using a standard solid-state reaction process is presented. Along with phase transitions at low temperature, a new phase transition at high temperature (873∘C at 20Hz, diffusive in character has been found where the lattice structure changes from monoclinic (space group: P2∕m to hexagonal (space group: P6∕mmm. This result places present ceramic in the list of potential candidate for intended high temperature applications. The AC conductivity data followed hopping type charge conduction and supports jump relaxation model. The experimental value of d33=98pC/N was found. The dependence of polarization and strain on electric field at room temperature suggested that lead-free Ba(Zr0.2Ti0.8O3 is a promising material for electrostrictive applications.

Spontaneous transition rates for electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2) and magnetic quadrupole (M2) transitions for He-like calcium and sulfur ions

International Nuclear Information System (INIS)

Kingston, A.E.; Norrington, P.H.; Boone, A.W.

2002-01-01

The spontaneous decay rates for the electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1) and magnetic quadrupole (M2) transitions between all of the 1s 2 , 1s2 l and 1s3 l states have been obtained for helium-like calcium and sulfur ions. To assess the accuracy of the calculations, the transition probabilities were calculated using two sets of configuration interaction wavefunctions. One set of wavefunctions was generated using the fully relativistic GRASP code and the other was obtained using CIV3, in which relativistic effects are introduced using the Breit-Pauli approximation. The transition rates, A values, oscillator strengths and line strengths from our two calculations are found to be similar and to compare very well with other recent results for Δn=1 or 2 transitions. For Δn=0 transitions the agreement is much less good; this is mainly due to differences in the calculated excitation energies. (author)

Raman spectroscopy, dielectric properties and phase transitions of Ag{sub 0.96}Li{sub 0.04}NbO{sub 3} ceramics

Energy Technology Data Exchange (ETDEWEB)

Niewiadomski, Adrian, E-mail: aniewiadomski@us.edu.pl [A. Chelkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Kania, Antoni [A. Chelkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Kugel, Godefroy E. [LMPOS, University of Metz and Supelec Metz, 2 rue E. Belin, Metz 57070 (France); Hafid, Mustapha [LPGC Dept. of Physics BP 133, Faculty of Science, Ibn Tofail University, 14000 Kenitra (Morocco); Sitko, Dorota [Institute of Physics, Pedagogical University, ul. Podchorazych 2, PL 30-084 Krakow (Poland)

2015-05-15

Highlights: • First Raman scattering studies of Ag{sub 0.96}Li{sub 0.04}NbO{sub 3}, allowed us to correlate temperature evolution of relaxational frequency γ{sub R}(T) with the Nb-ion dynamics and showed its changes at freezing temperature and ferrielectric transition. - Abstract: Silver lithium niobates Ag{sub 1−x}Li{sub x}NbO{sub 3} are promising lead free piezoelectrics. Good quality Ag{sub 0.96}Li{sub 0.04}NbO{sub 3} ceramics were obtained. Dielectric and DSC studies showed that, in comparison to AgNbO{sub 3,} temperatures of phase transitions slightly decrease. Dielectric studies pointed to enhancement of polar properties. Remnant polarisations achieves value of 0.6 μC/cm{sup 2}. Maximum of ϵ(T) dependences related to the relaxor-like ferroelectric/ferrielectric M{sub 1}–M{sub 2} transition becomes higher and more frequency dependent. Analysis of Raman spectra showed that two modes at 50 and 194 cm{sup −1} exhibit significant softening. Low frequency part of the Raman spectra which involve central peak and soft mode were analysed using two models. CP was assumed as relaxational vibration and described by Debye function. The slope of temperature dependences of relaxational frequency γ{sub R}(T) changes at approximately 470 and 330 K, indicating that slowing down process of relaxational vibrations changes in the vicinity of partial freezing of Nb-ion dynamics T{sub f} and further freezing at ferroelectric/ferrielectric phase transition.

Reentrant metal-insulator transition in the Cu-doped manganites La1-x Pbx MnO3 (x˜0.14) single crystals

Science.gov (United States)

Zhao, B. C.; Song, W. H.; Ma, Y. Q.; Ang, R.; Zhang, S. B.; Sun, Y. P.

2005-10-01

Single crystals of La1-x Pbx Mn1-y-z Cuy O3 ( x˜0.14 ; y=0 ,0.01,0.02,0.04,0.06; z=0.02 ,0.08,0.11,0.17,0.20) are grown by the flux growth technique. The effect of Cu doping at the Mn-site on magnetic and transport properties is studied. All studied samples undergo a paramagnetic-ferromagnetic transition. The Curie temperature TC decreases and the transition becomes broader with increasing Cu-doping level. The high-temperature insulator-metal (I-M) transition moves to lower temperature with increasing Cu-doping level. A reentrant M-I transition at the low temperature T* is observed for samples with y⩾0.02 . In addition, T* increases with increasing Cu-doping level and is not affected by applied magnetic fields. Accompanying the appearance of T* , there exists a large, almost constant magnetoresistance (MR) below T* except for a large MR peak near TC . This reentrant M-I transition is ascribed to charge carrier localization due to lattice distortion caused by the Cu doping at Mn sites.

Absolute M1 and E2 Transition Probabilities in 233U

International Nuclear Information System (INIS)

Malmskog, S.G.; Hoejeberg, M.

1967-08-01

Using the delayed coincidence technique, the following half lives have been determined for different excited states in 233 U: T 1/2 (311.9 keV level) = (1.20 ± 0.15) x 10 -10 sec, T 1/2 (340.5 keV level) = (5.2 ± 1.0) x 10 -11 sec, T 1/2 (398.6 keV level) = (5.5 ± 2.0) x 10 -11 sec and T 1/2 (415.8 keV level) -11 sec. From these half life determinations, together with earlier known electron intensities and conversion coefficients, 22 reduced B(Ml) and B(E2) transition probabilities (including 9 limits) have been deduced. The rotational transitions give information on the parameters δ and (g K - g R ) . The experimental M1 and E2 transition rates between members of different bands have been analysed in terms of the predictions of the Nilsson model, taking also pairing correlations and Coriolis coupling effects into account

Theoretical models for asteroseismology of DA white dwarf stars

Energy Technology Data Exchange (ETDEWEB)

Bradley, P.A. [XTA, MS B220, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

1996-09-01

Because white dwarfs are the most common end state of stellar evolution, determining their internal structure will yield many clues about the final stages of stellar evolution and the physics of matter under extreme conditions. We present the results of our parametric survey of evolutionary models of compositionally stratified white dwarfs with hydrogen surface layers (DA white dwarfs) and provide a comprehensive set of theoretical {ital g}-mode pulsation periods for comparison to observations of pulsating DA white dwarfs. This survey complements the previous survey of helium atmosphere (DB) white dwarf periods of Bradley, Winget, & Wood. We show how to use the periods of low-overtone and/or trapped modes to constrain the internal structure of pulsating DA white dwarfs by utilizing their sensitivity to the total stellar mass and the location of the hydrogen/helium transition zone. We use G117-B15A as an example to demonstrate the potential of our models for asteroseismology; we suggest that G117-B15A has a mass of 0.55 {ital M}{sub {circle_dot}} and a hydrogen layer mass of {approx_equal}1.5{times}10{sup {minus}4} {ital M}{sub {asterisk}}. {copyright} {ital 1996 The American Astronomical Society.}

First Observation of {tau}{r_arrow}3{pi}{eta}{nu}{sub {tau}} and {tau}{r_arrow} {ital f}{sub 1}{pi}{nu}{sub {tau}} Decays

Energy Technology Data Exchange (ETDEWEB)

Bergfeld, T.; Eisenstein, B.I.; Ernst, J.; Gladding, G.E.; Gollin, G.D.; Hans, R.M.; Johnson, E.; Karliner, I.; Marsh, M.A.; Palmer, M.; Selen, M.; Thaler, J.J. [University of Illinois, Champaign-Urbana, Illinois 61801 (United States); Edwards, K.W.; Edwards, K.W. [the Institute of Particle Physics, Montreal, Quebec (Canada); Bellerive, A.; Bellerive, A.; Janicek, R.; Janicek, R.; MacFarlane, D.B.; MacFarlane, D.B.; Patel, P.M.; Patel, P.M. [the Institute of Particle Physics, Montreal, Quebec (Canada); Sadoff, A.J. [Ithaca College, Ithaca, New York 14850 (United States); Ammar, R.; Baringer, P.; Bean, A.; Besson, D.; Coppage, D.; Darling, C.; Davis, R.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, N. [University of Kansas, Lawrence, Kansas 66045 (United States); Anderson, S.; Kubota, Y.; Lee, S.J.; ONeill, J.J.; Patton, S.; Poling, R.; Riehle, T.; Savinov, V.; Smith, A. [University of Minnesota, Minneapolis, Minnesota 55455 (United States); Alam, M.S.; Athar, S.B.; Ling, Z.; Mahmood, A.H.; Severini, H.; Timm, S.; Wappler, F. [State University of New York at Albany, Albany, New York 12222 (United States); Anastassov, A.; Blinov, S.; Duboscq, J.E.; Fujino, D.; Gan, K.K.; Hart, T.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Spencer, M.B.; Sung, M.; Undrus, A.; Wanke, R.; Wolf, A.; Zoeller, M.M. [The Ohio State University, Columbus, Ohio 43210 (United States); Nemati, B.; Richichi, S.J.; Ross, W.R.; Skubic, P. [University of Oklahoma, Norman, Oklahoma 73019 (United States); Bishai, M.; Fast, J.; Gerndt, E.; Hinson, J.W.; Menon, N.; Miller, D.H.; Shibata, E.I.; Shipsey, I.P.; Yurko, M. [Purdue University, West Lafayette, Indiana 47907 (United States); Gibbons, L.; Glenn, S.; Johnson, S.D.; Kwon, Y.; Roberts, S.; Thorndike, E.H. [University of Rochester, Rochester, New York 14627 (United States); Jessop, C.P.; Lingel, K.; Marsiske, H.; Perl, M.L.; Ugolini, D.; Wang, R.; Zhou, X.; and others

1997-09-01

We have observed new channels for {tau} decays with an {eta} in the final state. We study 3-prong tau decays, using the {eta}{r_arrow}{gamma}{gamma} and {eta}{r_arrow}3{pi}{sup 0} decay modes and 1-prong decays with two {pi}{sup 0} {close_quote}s using the {eta}{r_arrow}{gamma}{gamma} channel. The measured branching fractions are B({tau}{sup {minus}}{r_arrow}{pi}{sup {minus}} {pi}{sup {minus}}{pi}{sup +}{eta}{nu}{sub {tau}})=(3.4{sup +0.6}{sub {minus}0.5} {plus_minus}0.6){times}10{sup {minus}4} and B({tau}{sup {minus}}{r_arrow}{pi}{sup {minus}} 2{pi}{sup 0}{eta}{nu}{sub {tau}}) =(1.4{plus_minus}0.6{plus_minus}0.3){times}10{sup {minus}4} . We observe clear evidence for f{sub 1}{r_arrow}{eta}{pi}{pi} substructure and measure B({tau}{sup {minus}}{r_arrow}f{sub 1}{pi}{sup {minus}}{nu}{sub {tau}})=(5.8{sup +1.4 }{sub {minus}1.3}{plus_minus}1.8){times}10{sup {minus}4} . We have also searched for {eta}{sup {prime}}(958) production and obtain 90{percent} C.L.upper limits B({tau}{sup {minus}}{r_arrow}{pi}{sup {minus}} {eta}{sup {prime}}{nu}{sub {tau}}){lt} 7.4{times}10{sup {minus}5} and B({tau}{sup {minus}}{r_arrow}{pi}{sup {minus}} {pi}{sup 0}{eta}{sup {prime}}{nu}{sub {tau} }){lt}8.0{times}10{sup {minus}5} . {copyright} {ital 1997} {ital The American Physical Society}

Measurement of K-conversion coefficient of the M3 transition in sup 112 In sup m

Energy Technology Data Exchange (ETDEWEB)

Krishna, K.R.; Sastry, D.L.; Reddy, K.V. (Andhra Univ., Visakhapatnam (India). Labs. for Nuclear Research); Chintalapudi, S.N. (Variable Energy Cyclotron Centre, Calcutta (India))

1991-11-01

The K-conversion coefficient of the 155 keV (M3) isomeric transition in the decay of {sup 112}In was measured using the normalized peak to gamma method. The {alpha}{sub K} value is found to be 4.82{+-}0.29 in agreement with the theoretical value of 5.12. (author).

High field induced magnetic transitions in the Y0.7E r0.3F e2D4.2 deuteride

Science.gov (United States)

Paul-Boncour, V.; Guillot, M.; Isnard, O.; Hoser, A.

2017-09-01

The influence of the partial Er for Y substitution on the crystal structure and magnetic properties of YF e2D4.2 has been investigated by high field magnetization and neutron diffraction experiments. Y0.7E r0.3F e2D4.2 compound crystallizes in the same monoclinic structure as YF e2D4.2 described in P c (P1c1) space group with D atoms located in 18 different tetrahedral interstitial sites. A cell volume contraction of 0.6% is observed upon Er substitution, inducing large modification of the magnetic properties. Electronic effect of D insertion as well as lowering of crystal symmetry are important factors determining the magnetic properties of Fe sublattice, which evolves towards more delocalized behavior and modifying the Er-Fe exchange interactions. In the ground state, the Er and Fe moments are arranged ferrimagnetically within the plane perpendicular to the monoclinic b axis and with average moments mEr=6.4 (3 ) μBEr-1 and mFe=2.0 (1 ) μBFe-1 at 10 K. Upon heating, mEr decreases progressively until TEr=55 K . Between 55 K and 75 K, the Fe sublattice undergoes a first-order ferromagnetic-antiferromagnetic (FM-AFM) transition with a cell volume contraction due to the itinerant metamagnetic behavior of one Fe site. In the AFM structure, mFe decreases until the Néel temperature TN=125 K . At high field, two different types of field induced transitions are observed. The Er moments become parallel to the Fe one and saturates to the E r3 + free ion value, leading to an unusual field induced FM arrangement at a transition field BTrans of only 78 kG below 30 K. Then above TM0=66 K , an AFM-FM transition of the Fe sublattice, accompanied by a cell volume increase is observed. BTrans increases linearly versus temperature and with a larger d BTrans/d T slope than for YF e2D4.2 . This has been explained by the additional contribution of Er induced moments above BTrans.

Formation of bulk metallic glasses in the Fe-M-Y-B (M = transition metal) system

Energy Technology Data Exchange (ETDEWEB)

Huang, X.M. [International Center for New-Structured Materials (ICNSM) and Laboratory of New-Structured Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Chang, C.T. [Institute for Material Research, Tohoku University, Sendai 980-8577 (Japan); Chang, Z.Y.; Wang, X.D.; Cao, Q.P. [International Center for New-Structured Materials (ICNSM) and Laboratory of New-Structured Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Shen, B.L.; Inoue, A. [Institute for Material Research, Tohoku University, Sendai 980-8577 (Japan); Jiang, J.Z. [International Center for New-Structured Materials (ICNSM) and Laboratory of New-Structured Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)], E-mail: jiangjz@zju.edu.cn

2008-07-28

In this work, quaternary Fe{sub 72-x}M{sub x}Y{sub 6}B{sub 22} (M = Ni, Co and Mo) bulk metallic glasses (BMGs) have been developed. It is found that a fully amorphous Fe{sub 68}Mo{sub 4}Y{sub 6}B{sub 22} cylindrical rod with 6.5 mm in diameter can be prepared by copper mold injection. These alloys have a high glass transition temperature of about 900 K with high fracture strengths up to about 3 GPa although they are still brittle. Magnetic measurements reveal that they are ferromagnetic at ambient temperature with low coercive force of about 2 A/m, saturation magnetization of about 0.7 T and effective permeability of about 7000 at 100 kHz. The newly developed Fe-based quaternary alloys exhibit excellent combination properties: superior glass forming ability (GFA), high glass transition temperature, and soft magnetic properties, which could have potential applications in electronic industries. Furthermore, the effect of Mo addition on GFA in the Fe-Y-B BMG system has been discussed compared with those of Ni and Co additions.

Micro-Raman study of the microheterogeneity in the MA-MC phase transition in 0.67PbMg1/3Nb2/3O3-0.33PbTiO3 single crystal

KAUST Repository

Yang, Y.

2011-04-20

Polarized Raman spectroscopy has been employed to investigate the evolution of the microstructure of 0.67PbMg1/3Nb2/3O3-0.33PbTiO3 (PMN-33%PT) single crystal in the temperature range from −195 to 300 °C. The M A-M C-cubic transition sequence was observed in the microareas with M A-type (space group Cm) and M C-type (space group Pm) monoclinic structures. Interestingly, the M A-M Cphase transition temperature exhibited remarkable microareal dependence due to the spatial inhomogeneity of polar nanoregions (PNRs). The M C-cubic phase transition took place at 155 °C in both microareas, which consisted well with previous reports. These results reveal that the phase transition in PMN-33%PT single crystal is closely related with the thermal dynamics of PNRs, which will be useful for understanding the microheterogeneity in this compound.

Phase transitions in Fe_0_._5Co_0_._5 (110) thin films

International Nuclear Information System (INIS)

Ramírez-Dámaso, G.; Castillo-Alvarado, F.L.; Rojas-Hernández, E.

2016-01-01

In this paper, we present calculations for two second-order phase transitions in (110) Fe_0_._5Co_0_._5 thin films with 11, 15, and 19 monoatomic layers. The lattice and magnetic transitions are based on thermodynamic equilibrium considerations of the magnetic alloy. The procedure proposed by Valenta and Sukiennicki was applied to calculate the composition x(i), the lattice order parameter t(i), and the magnetic order parameter σ(i) as a function of temperature T. We confirmed that both phase transitions, lattice and magnetic, are of the second order, in accordance with experimental results in the literature. The obtained behavior of these parameters indicates their inhomogeneity due to the boundary conditions on the surfaces of the thin film.

A Low-mass Exoplanet Candidate Detected by K2 Transiting the Praesepe M Dwarf JS 183

Science.gov (United States)

Pepper, Joshua; Gillen, Ed; Parviainen, Hannu; Hillenbrand, Lynne A.; Cody, Ann Marie; Aigrain, Suzanne; Stauffer, John; Vrba, Frederick J.; David, Trevor; Lillo-Box, Jorge; Stassun, Keivan G.; Conroy, Kyle E.; Pope, Benjamin J. S.; Barrado, David

2017-04-01

We report the discovery of a repeating photometric signal from a low-mass member of the Praesepe open cluster that we interpret as a Neptune-sized transiting planet. The star is JS 183 (HSHJ 163, EPIC 211916756), with T eff = 3325 ± 100 K, M * = 0.44 ± 0.04 M ⊙, R * = 0.44 ± 0.03 R ⊙, and {log}{g}* = 4.82+/- 0.06. The planet has an orbital period of 10.134588 days and a radius of R P = 0.32 ± 0.02 R J. Since the star is faint at V = 16.5 and J = 13.3, we are unable to obtain a measured radial velocity orbit, but we can constrain the companion mass to below about 1.7 M J, and thus well below the planetary boundary. JS 183b (since designated as K2-95b) is the second transiting planet found with K2 that resides in a several-hundred-megayear open cluster; both planets orbit mid-M dwarf stars and are approximately Neptune sized. With a well-determined stellar density from the planetary transit, and with an independently known metallicity from its cluster membership, JS 183 provides a particularly valuable test of stellar models at the fully convective boundary. We find that JS 183 is the lowest-density transit host known at the fully convective boundary, and that its very low density is consistent with current models of stars just above the fully convective boundary but in tension with the models just below the fully convective boundary.

Impact of PSA density of transition zone as a potential parameter in reducing the number of unnecessary prostate biopsies in patients with psa levels between 2.6 and 10.0 ng/mL.

Science.gov (United States)

Castro, Hugo A Socrates; Iared, Wagner; Santos, José Eduardo Mourão; Solha, Raphael Sandes; Shigueoka, David Carlos; Ajzen, Sergio Aron

2018-04-10

To assess the accuracy of prostate-specific antigen (PSA) adjusted for the transition zone volume (PSATZ) in predicting prostate cancer by comparing the ability of several PSA parameters in predicting prostate cancer in men with intermediate PSA levels of 2.6 - 10.0 ng/mL and its ability to reduce unnecessary biopsies. This study included 656 patients referred for prostate biopsy who had a serum PSA of 2.6 - 10.0 ng/mL. Total prostate and transition zone volumes were measured by transrectal ultrasound using the prolate ellipsoid method. The clinical values of PSA, free-to-total (F/T) ratio, PSA density (PSAD) and PSATZ for the detection of prostate cancer were calculated and statistical comparisons between biopsy-positive (cancer) and biopsy-negative (benign) were conducted. Cancer was detected in 172 patients (26.2%). Mean PSA, PSATZ, PSAD and F/T ratio were 7.5 ng/mL, 0.68 ng/mL/cc. 0.25 ng/mL/cc and 0.14 in patients with prostate cancer and 6.29 ng/mL, 0.30 ng/mL/cc, 0.16 ng/mL/cc and 0.22 in patients with benign biopsies, respectively. ROC curves analysis demonstrated that PSATZ had a higher area under curve (0,838) than F/T ratio (0,806) (PPSA. Compared to other PSA related parameters, it was better in differentiating between prostate cancer and benign prostatic enlargement. Also, PSATZ could reduce a significant number of unnecessary biopsies. Copyright® by the International Brazilian Journal of Urology.

Branching ratio for the isoscalar transition 2+, T = 1, 1.95 MeV→0+, T = 1, 0.66 MeV in 22Na

International Nuclear Information System (INIS)

Vermeer, W.J.; Poletti, A.R.

1982-01-01

The branching ratio for the isoscalar transition 2 + , T = 1, 1.95 MeV→0 + , T = 1, 0.66 MeV in 22 Na was measured as (0.29+-0.05)% of the total decays of the 1.95MeV level. This, together with the measured mean-life of this level, gives an E2 strength of (16+-5) Wu, in good agreement with the estimate of 18 Wu obtained from the analogue transitions in 22 Ne and 22 Mg assuming a linear relationship between M(E2) and Tsub(z). Upper limits for some weak decay branches in 19 F were also obtained. (author)

Piezoelectric properties and diffusion phase transition around PPT of La-doped (Na{sub 0.52}K{sub 0.44}Li{sub 0.04}) Nb{sub 0.8}Ta{sub 0.2}O{sub 3} lead-free piezoelectric ceramics

Energy Technology Data Exchange (ETDEWEB)

Yang, Wenlong, E-mail: yangwenlong1983@163.com; Wang, Li; Li, Haidong; Han, Junsheng; Xiu, Hanjiang; Zhou, Zhongxiang

2016-10-01

Lead-free ceramics (Na{sub 0.52}K{sub 0.44}Li{sub 0.04}){sub 1−3x}La{sub x}Nb{sub 0.8}Ta{sub 0.2}O{sub 3} (KNLNT-Lax, x=0.00, 0.25, 0.5, 0.75, 1.00, 1.25 mol%) as non-polluting materials were prepared by solid state reaction method. The structure, piezoelectric proprieties and temperature stability of KNLNT ceramic with different La doping concentrations were investigated. The results show a transition from orthorhombic-tetragonal mix phase to tetragonal single phase with the variation of La{sup 3+} concentrations. The SEM micrographs of surface and fractured surface show a dense microstructure with few micropores. The La-doped KNLTN ceramic will be an alternative candidate contributes to excellent piezoelectric properties, which are found in the 0.75 mol% La-doped KNLNT ceramics, with d{sub 33}=215pC/N, k{sub p}=42.8%and Q{sub m}=89. It has been remarkably improved that the temperature stability of KNLTN-Lax piezoelectric properties at room temperature, and the dielectric relaxation can be observed obviously. The mechanism of La doping was analyzed in terms of valence compensation and polymorphic phase transition (PPT) diffusion. The orthorhombic-tetragonal phase transition around room temperature and the relaxation transition were considered contributing to the excellent piezoelectric performance and improved temperature stability of La{sup 3+}-doped KNLTN.

Electric response of Pb0.99[(Zr0.90Sn0.10)0.968Ti0.032]0.98Nb0.02O3 ceramics to the shock-wave-induced ferroelectric-to-antiferroelectric phase transition

International Nuclear Information System (INIS)

Jiang Dongdong; Zhang Na; Feng Yujun; Du Jinmei; Gu Yan

2012-01-01

Highlights: ► Shock wave induces the FE-to-AFE phase transition in PbNb(Zr,Sn,Ti)O 3 . ► Depoling current due to phase transition depends on shock pressure and load resistance. ► Shock pressure promotes the phase transition in short-circuit case. ► Increasing load resistance decreases the released charge. - Abstract: Shock-wave-enforced ferroelectric (FE)-to-antiferroelectric (AFE) phase transition releases a large electrical polarization, having application in pulse power technology. In the present work, the depoling currents under shock wave compression were investigated in Pb 0.99 [(Zr 0.90 Sn 0.10 ) 0.968 Ti 0.032 ] 0.98 Nb 0.02 O 3 (PZST) ceramics with composition close to the FE/AFE phase boundary. Shock wave was generated by gas-gun and propagated in a direction perpendicular to the remanent polarization. It was found that the shock pressure promoted the phase transition under the short-circuit condition. The shock pressure dependence of the released charge was associated with the evolution of FE-to-AFE phase transition. The onset of phase transition was about 0.40 GPa and complete transformation occurred at 1.23 GPa. However, the released charge decreased with increasing load resistance. The reason may be that the electric field suppresses the phase transition in uncompressed zone and/or shock induces conductivity in compressed zone. Results lay the foundation for application of PZST ceramics in shock-activated power supply.

Synthesis, electrochemical investigation and structural analysis of doped Li[Ni0.6Mn0.2Co0.2-xMx]O2 (x = 0, 0.05; M = Al, Fe, Sn) cathode materials

Science.gov (United States)

Eilers-Rethwisch, Matthias; Winter, Martin; Schappacher, Falko Mark

2018-05-01

Layered Ni-rich Li[Ni0.6Mn0.2Co0.2-xMx]O2 cathode materials (x = 0, 0.05; M = Al, Fe, Sn) are synthesized via a co-precipitation synthesis route and the effect of dopants on the structure and electrochemical performance is investigated. All synthesized materials show a well-defined layered structure of the hexagonal α-NaFeO2 phase investigated by X-ray diffraction (XRD). Undoped LiNi0.6Mn0.2Co0.2O2 exhibits a discharge capacity of 170 mAh g-1 in Li-metal 2032 coin-type cells. Doped materials reach lower capacities between 145 mAh g-1 for Al and 160 mAh g-1 for Sn. However, all doped materials prolong the cycle life by up to 20%. Changes of the lattice parameter before and after delithiation yield information about structural stability. A smaller repulsion of the transition metal layer during delithiation in the Sn-doped material leads to a smaller expansion of the unit cell, which results in enhanced structural stability of the material. The improved structural stability of Sn-doped NMC cathode active material is proven by thermal investigations with the help of Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA).

Highly retarded M2 transition in 90Nb

International Nuclear Information System (INIS)

Sergeev, V.O.

2006-01-01

One studied properties of 2.3 keV transition between 124.67 (4 - ) and 122.37 keV (6 + ) in 90 Nb. The mentioned M2-transition is shown to be retarded by approximately 10 4 times and provided explanations of the mentioned extraordinary high factor of deceleration. One evaluated impurity of E3 possible multipolarity constituent in the mentioned transition (δ 2 [ru

Second order magnetic phase transition and scaling analysis in iron doped manganite La0.7Ca0.3Mn1−xFexO3 compounds

International Nuclear Information System (INIS)

Ginting, Dianta; Nanto, Dwi; Denny, Yus Rama; Tarigan, Kontan; Hadi, Syamsul; Ihsan, Mohammad; Rhyee, Jong-Soo

2015-01-01

We investigated magnetic properties of La 0.7 Ca 0.3 Mn 1−x Fe x O 3 (x=0.09 and 0.11) compounds in terms of isothermal magnetization analysis and scaling behavior with various critical exponents. From the Landau theory of magnetic phase transition, we found that the paramagnetic to ferromagnetic phase transition in La 0.7 Ca 0.3 Mn 1−x Fe x O 3 (x=0.09 and 0.11) compounds is the type of second order magnetic transition (SOMT), which contrary to the first order magnetic transition (FOMT) for low Fe-doped compounds (x<0.09) in previous reports. When we investigate the critical behavior of the compounds near T=T c by the modified Arrott plot, Kouvel–Fisher plots, and critical isothermal analysis, the estimated critical exponents β, γ, and δ are in between the theoretically predicted values for three-dimensional Heisenberg and mean-field interaction models. It is noteworthy that the scaling relations are obeyed in terms of renormalization magnetization m=ε −β M(H,ε) and renormalized field h=|ε| β+γ H. Temperature-dependent effective exponents β eff and γ eff correspond to the ones of disordered ferromagnets. It is shown that the magnetic state of the compounds is not fully described by the conventional localized-spin interaction model because the ferromagnetic interaction has itinerant character by increasing Fe-doping concentration. - Highlights: • The ferromagnetic phase transition is of second order in La 0.7 Ca 0.3 Mn 1−x Fe x O 3 . • The critical exponents are in between the 3D Heisenberg and mean-field models. • The ferromagnetic interaction becomes more itinerant by Fe-doping

Lead apatites: structural variations among Pb₅(BO₄)₃ Cl with B = P (pyromorphite), As (mimetite) and V (vanadinite)

Energy Technology Data Exchange (ETDEWEB)

Antao, Sytle M.; Dhaliwal, Inayat

2018-01-01

The crystal structure of four Pb apatite samples, Pb₅(<italic>B>O₄)₃Cl, was refined with synchrotron high-resolution powder X-ray diffraction data, Rietveld refinements, space group<italic>P>6₃/<italic>mandZ>= 2. For this isotypic series,<italic>B>= P⁵⁺ is pyromorphite,<italic>B>= As⁵⁺is mimetite and<italic>B>= V⁵⁺is vanadinite. The ionic radius for As⁵⁺(0.355 Å) is similar to that of V⁵⁺(0.335 Å), and this is twice as large as that for P⁵⁺(0.170 Å). However, the<italic>c>unit-cell parameter for mimetite is surprisingly different from that of vanadinite, although their unit-cell volumes,<italic>V>, are almost equal to each other. No explanation was available for this peculiar<italic>c>-axis value for mimetite. Structural parameters such as average $\\langle$<italic>B>—O$\\rangle$ [4], $\\langle$Pb1—O₉$\\rangle$ [9] and $\\langle$Pb2—O₆Cl₂$\\rangle$ [8] distances increase linearly with<italic>V> (the coordination numbers for the cations are given in square brackets). Mimetite has a short Pb2—O1 distance, so the O1 oxygen atom interacts with the 6<italic>s>²lone-pair electrons of the Pb²⁺ cation that causes the Cl—Cl distance (=<italic>c>/2) to increase to the largest value in the series because of repulsion, which causes the<italic>c>-axis to increase anomalously. Although Pb apatite minerals occur naturally in ore deposits, they are also formed as scaly deposits in lead water pipes that give rise to lead in tap water, as was found recently in Flint, Michigan, USA. It is important to identify Pb-containing phases in water-pipe deposits.

Squid measurement of the Verwey transition on epitaxial (1 0 0) magnetite thin films

International Nuclear Information System (INIS)

Dediu, V.; Arisi, E.; Bergenti, I.; Riminucci, A.; Solzi, M.; Pernechele, C.; Natali, M.

2007-01-01

We report results on epitaxial magnetite (Fe 3 O 4 ) thin films grown by electron beam ablation on (1 0 0) MgAl 2 O 4 substrates. At 120 K magnetite undergoes a structural and electronic transition, the so-called Verwey transition, at which magnetic and conducting properties of the material change. We observed the Verwey transition on epitaxial films with a thickness of 50 nm by comparing zero-field cooling (ZFC) and field cooling (FC) curves measured with a superconducting quantum interference device (SQUID) magnetometer. Observation of the Verwey transition by SQUID measurements in the films is sign of their high crystalline quality. Room temperature ferromagnetism has also been found by magneto-optical Kerr rotation (MOKE) and confirmed by SQUID measurements, with a hysteresis loop showing a coercive field of hundreds of Oe

Two neutrino double-β decay of 94 ≤ A ≤ 150 nuclei for the 0{sup +} → 2{sup +} transition

Energy Technology Data Exchange (ETDEWEB)

Singh, Yash Kaur; Chandra, R. [Babasaheb Bhimrao Ambedkar University, Department of Applied Physics, Lucknow (India); Raina, P.K. [Indian Institute of Technology, Department of Physics, Ropar, Rupnagar (India); Rath, P.K. [University of Lucknow, Department of Physics, Lucknow (India)

2017-12-15

Within the PHFB approach, the 0{sup +} → 2{sup +} transition of two neutrino double-β decay of {sup 94,96}Zr, {sup 100}Mo, {sup 104}Ru, {sup 110}Pd, {sup 128,130}Te and {sup 150}Nd isotopes is studied employing wave functions generated with four different parametrizations of the pairing plus multipole type of two-nucleon interaction and the summation method. In comparison to the 0{sup +} → 0{sup +} transition, the nuclear transition matrix elements M{sub 2ν} (2{sup +}) are quite sensitive to the deformation of the yrast 2{sup +} state. Consideration of the available theoretical and experimental results suggests that the observation of the 0{sup +} → 2{sup +} transition of 2νβ{sup -}β{sup -} decay may be possible in {sup 96}Zr, {sup 100}Mo, {sup 130}Te and {sup 150}Nd isotopes. The effect of deformation on the M{sub 2ν} (2{sup +}) is also studied. (orig.)

Heavy metal concentration in forage grasses and extractability from some acid mine spoils

Energy Technology Data Exchange (ETDEWEB)

Taylor, R.W.; Ibeabuchi, I.O.; Sistani, K.R.; Shuford, J.W. (Alabama A and M University, Normal (United States). Department of Plant and Soil Science)

1993-06-01

Laboratory and greenhouse studies were conducted on several forage grasses, bermudagrass ([ital Cynodon dactylon]), creeping red fescue ([ital Festuca rubra]), Kentucky 31-tall fescue ([ital Festuca arundinacea]), oat ([ital Avena sativa]), orchardgrass ([ital Dactylis glomerata]), perennial ryegrass ([ital Lolium perenne]), sorghum ([ital Sorghum bicolor]), triticale (X. [ital triticosecale Wittmack]), and winter wheat ([ital Triticum aestivum]) grown on three Alabama acid mine spoils to study heavy metal accumulation, dry matter yield and spoil metal extractability by three chemical extractants (Mehlich 1, DTPA, and 0.1 M HCl). Heavy metals removed by these extractants were correlated with their accumulation by several forage grasses. Among the forages tested, creeping red fescue did not survive the stressful conditions of any of the spoils, while orchard grass and Kentucky 31-tall fescue did not grow in Mulberry spoil. Sorghum followed by bermudagrass generally produced the highest dry matter yield. However, the high yielding bermudagrass was most effective in accumulating high tissue levels of Mn and Zn from all spoils (compared to the other grasses) but did not remove Ni. On the average, higher levels of metals were extracted from spoils in the order of 0.1 M HCl[gt] Mehlich 1[gt] DTPA. However, DTPA extracted all the metals from spoils while Mehlich 1 did not extract Pb and 0.1 M HCl did not extract detectable levels of Ni. All of the extractants were quite effective in determining plant available Zn from the spoils. For the other metals, the effective determination of plant availability depended on the crop, the extractant, and the metal in concert. 20 refs., 6 tabs.

ARGUS laser plasma experiments at 1.06 μm, 0.53 μm and 0.35 μm

International Nuclear Information System (INIS)

Turner, R.E.; Campbell, E.M.; Mead, W.C.; Ze, F.; Max, C.; Phillion, D.W.; Lee, P.; Pruett, B.; Tirsell, G.; Lasinski, B.F.

1982-01-01

ARGUS wavelength scaling experiments have been performed on low (Be) and high (Au) Z disk targets, with laser wavelengths of 1.06 μm, 0.53 μm and 0.35 μm. The laser provided a 700 psec pulse, with up to 100J and 1.06 μm; 200J at 0.53 μm; and 40J at 0.35 μm. Laser intensities on target ranged from 3 x 10 13 to over 3 x 10 15 W/cm 2 , using an f/2.2 focusing system. Box calorimeter measurements show the expected increasing fractional absorption at shorter laser wavelengths; absolutely calibrated hard x-ray detectors show the number of suprathermal electrons to be greatly decreased. Scattered light measurements concentrated on stimulated Raman scattering, and the 3/2 harmonic. The SRS was spectrally and temporally resolved during 0.53 μm irradiations; our measurements showed the scattering to be principally from the convective instability, near tenth critical density. Near ω/2, a double peaked spectral feature is observed. The time resolved data show a number of interesting features, which are discussed

Optical transition radiation interferometry for the A0 photoinjector

International Nuclear Information System (INIS)

Kazakevich, G.; Novosibirsk, IYF; Edwards, H.; Fliller, R.; Nagaitsev, S.; Ruan, J.; Thurman-Keup, R.; Fermilab

2008-01-01

Optical Transition Radiation Interferometry (OTRI) is a promising diagnostic technique and has been successfully developed and used for investigation of relativistic beams. For mid-energy accelerators the technique is traditionally based on thin polymer films (the first one is being transparent for visible light), which causes beam multiple scattering of about 1 mrad. A disadvantage of those films is unacceptable vacuum properties for photoinjectors and accelerators using superconducting cavities. We have studied the application of thin mica sheets for the OTRI diagnostics at the A0 Photoinjector in comparison with 2.5 (micro)m thick Mylar films. This diagnostic is also applicable for the ILCTA-NML accelerator test facility that is planned at Fermilab. This report discusses the experimental setups of the OTR interferometer for the A0 Photoinjector and presents comparisons of simulations and measurements obtained using Mylar and mica-based interferometers

Search for weak M 1 transitions in 48Ca with inelastic proton scattering

Science.gov (United States)

Mathy, M.; Birkhan, J.; Matsubara, H.; von Neumann-Cosel, P.; Pietralla, N.; Ponomarev, V. Yu.; Richter, A.; Tamii, A.

2017-05-01

Background: The quenching of spin-isospin modes in nuclei is an important field of research in nuclear structure. It has an impact on astrophysical reaction rates and on fundamental processes like neutrinoless double-β decay. Gamow-Teller (GT) and spin-flip M 1 strengths are quenched. Concerning the latter, the Jπ=1+ resonance in the doubly magic nucleus 48Ca, dominated by a single transition, serves as a reference case. Purpose: The aim of the present work is to search for weak M 1 transitions in 48Ca with a high-resolution (p ,p') experiment at 295 MeV and forward angles including 0∘ and a comparison with results from a similar study using backward-angle electron scattering at low momentum transfers in order to estimate their contribution to the total B (M 1 ) strength in 48Ca. Methods: The spin-M 1 cross sections of individual peaks in the spectra are deduced with a multipole decomposition analysis (MDA) and converted to reduced spin-M 1 transition strengths by using the unit cross-section method. For a comparison with electron-scattering results, corresponding reduced B (M 1 ) transition strengths are extracted following the approach outlined in Birkhan et al. [Phys. Rev. C 93, 041302(R) (2016), 10.1103/PhysRevC.93.041302]. Results: In total, 30 peaks containing a M 1 contribution are found in the excitation energy region 7-13 MeV. The resulting B (M 1 ) strength distribution compares well to the electron-scattering results considering different factors limiting the sensitivity in both experiments and the enhanced importance of mechanisms breaking the proportionality of nuclear cross sections and electromagnetic matrix elements for weak transitions as studied here. The total strength of 1.14(7) μN2 deduced assuming a nonquenched isoscalar part of the (p ,p') cross sections agrees with the (e ,e') result of 1.21(13) μN2. A bin-wise analysis above 10 MeV provides an upper limit of 1.51(17) μN2. Conclusions: The present results confirm the previous electron

Phase transitions in Fe{sub 0.5}Co{sub 0.5} (110) thin films

Energy Technology Data Exchange (ETDEWEB)

Ramírez-Dámaso, G., E-mail: gramirezd@ipn.mx [Escuela Superior de Ingeniería y Arquitectura “Unidad Ticomán” del Instituto Politécnico Nacional, Av. Ticomán No. 600, Col. San José Ticomán, Del. G. A. M., C. P. 07330 Ciudad de México (Mexico); Castillo-Alvarado, F.L. [Escuela Superior de Física y Matemáticas del Instituto Politécnico Nacional, Edificio 9, Col. San Pedro Zacatenco, C. P. 07738 Ciudad de México (Mexico); Rojas-Hernández, E. [Escuela Superior de Ingeniería y Arquitectura “Unidad Ticomán” del Instituto Politécnico Nacional, Av. Ticomán No. 600, Col. San José Ticomán, Del. G. A. M., C. P. 07330 Ciudad de México (Mexico)

2016-12-15

In this paper, we present calculations for two second-order phase transitions in (110) Fe{sub 0.5}Co{sub 0.5} thin films with 11, 15, and 19 monoatomic layers. The lattice and magnetic transitions are based on thermodynamic equilibrium considerations of the magnetic alloy. The procedure proposed by Valenta and Sukiennicki was applied to calculate the composition x(i), the lattice order parameter t(i), and the magnetic order parameter σ(i) as a function of temperature T. We confirmed that both phase transitions, lattice and magnetic, are of the second order, in accordance with experimental results in the literature. The obtained behavior of these parameters indicates their inhomogeneity due to the boundary conditions on the surfaces of the thin film.

M1 transitions in the (sdg) boson model

Energy Technology Data Exchange (ETDEWEB)

Kuyucak, S.; Morrison, I.

1988-03-03

Using the 1/N expansion technique we derive expressions for ..beta.. -> g, ..gamma.. -> g and ..gamma.. -> ..gamma.. M1 transitions in a general boson model. The M1 matrix elements in the sdg-boson model are similar in form to those in the neutron-proton IBM. Comparisons are made to some selected M1 data exhibiting collective character.

Dynamics of the magneto structural phase transition in La(Fe{sub 0.9}Co{sub 0.015}Si{sub 0.085}){sub 13} observed by magneto-optical imaging

Energy Technology Data Exchange (ETDEWEB)

Kuepferling, M., E-mail: m.kuepferling@inrim.it; Basso, V. [Istituto Nazionale di Ricerca Metrologica (INRIM), Strada delle Cacce 91, 10135 Turin (Italy); Bennati, C. [Istituto Nazionale di Ricerca Metrologica (INRIM), Strada delle Cacce 91, 10135 Turin (Italy); Department of Applied Science and Technology, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy); Laviano, F.; Ghigo, G. [Department of Applied Science and Technology, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Turin (Italy)

2014-05-07

We investigate the temperature induced ferromagnetic to paramagnetic phase transition in Co substituted La(Fe{sub x}Co{sub y}Si{sub 1−x−y}){sub 13} with x = 0.9 and low Co content of y = 0.015 (T{sub c}≃200 K) by means of magneto-optical imaging with indicator film and by calorimetry at very low temperature rates. We were able to visualize the motion of the ferromagnetic (FM)/paramagnetic (PM) front which is forming reproducible patterns independently of the temperature rate. The average velocity of the FM/PM front was calculated to be 10{sup −4} m/s during the continuous propagation and 4×10{sup −3} m/s during an avalanche. The heat flux was measured at low temperature rates by a differential scanning calorimeter and shows a reproducible sequence of individual and separated avalanches which occurs independently of the rate. We interpret the observed effects as the result of the athermal character of the phase transition.

K2-155: A Bright Metal-poor M Dwarf with Three Transiting Super-Earths

Science.gov (United States)

Hirano, Teruyuki; Dai, Fei; Livingston, John H.; Fujii, Yuka; Cochran, William D.; Endl, Michael; Gandolfi, Davide; Redfield, Seth; Winn, Joshua N.; Guenther, Eike W.; Prieto-Arranz, Jorge; Albrecht, Simon; Barragan, Oscar; Cabrera, Juan; Cauley, P. Wilson; Csizmadia, Szilard; Deeg, Hans; Eigmüller, Philipp; Erikson, Anders; Fridlund, Malcolm; Fukui, Akihiko; Grziwa, Sascha; Hatzes, Artie P.; Korth, Judith; Narita, Norio; Nespral, David; Niraula, Prajwal; Nowak, Grzegorz; Pätzold, Martin; Palle, Enric; Persson, Carina M.; Rauer, Heike; Ribas, Ignasi; Smith, Alexis M. S.; Van Eylen, Vincent

2018-03-01

We report on the discovery of three transiting super-Earths around K2-155 (EPIC 210897587), a relatively bright early M dwarf (V = 12.81 mag) observed during Campaign 13 of the NASA K2 mission. To characterize the system and validate the planet candidates, we conducted speckle imaging and high-dispersion optical spectroscopy, including radial velocity measurements. Based on the K2 light curve and the spectroscopic characterization of the host star, the planet sizes and orbital periods are {1.55}-0.17+0.20 {R}\\oplus and 6.34365 ± 0.00028 days for the inner planet; {1.95}-0.22+0.27 {R}\\oplus and 13.85402 ± 0.00088 days for the middle planet; and {1.64}-0.17+0.18 {R}\\oplus and 40.6835 ± 0.0031 days for the outer planet. The outer planet (K2-155d) is near the habitable zone, with an insolation 1.67 ± 0.38 times that of the Earth. The planet’s radius falls within the range between that of smaller rocky planets and larger gas-rich planets. To assess the habitability of this planet, we present a series of three-dimensional global climate simulations, assuming that K2-155d is tidally locked and has an Earth-like composition and atmosphere. We find that the planet can maintain a moderate surface temperature if the insolation proves to be smaller than ∼1.5 times that of the Earth. Doppler mass measurements, transit spectroscopy, and other follow-up observations should be rewarding, as K2-155 is one of the optically brightest M dwarfs known to harbor transiting planets.

Proteome Remodeling in Response to Sulfur Limitation in “ Candidatus Pelagibacter ubique”

Energy Technology Data Exchange (ETDEWEB)

Smith, Daniel P.; Nicora, Carrie D.; Carini, Paul; Lipton, Mary S.; Norbeck, Angela D.; Smith, Richard D.; Giovannoni, Stephen J.; Wilmes, Paul

2016-07-12

The alphaproteobacterium “<italic>Candidatus>Pelagibacter ubique” strain HTCC1062 and most other members of the SAR11 clade lack genes for assimilatory sulfate reduction, making them dependent on organosulfur compounds that occur naturally in seawater. To investigate how these cells adapt to sulfur limitation, batch cultures were grown in defined medium containing either limiting or nonlimiting amounts of dimethylsulfoniopropionate (DMSP) as the sole sulfur source. Protein and mRNA expression were measured before, during, and after the transition from exponential growth to stationary phase. Two distinct responses were observed, one as DMSP became exhausted and another as the cells acclimated to a sulfur-limited environment. The first response was characterized by increased transcription and translation of all “<italic>Ca>. Pelagibacter ubique” genes downstream from the previously confirmed<italic>S>-adenosyl methionine (SAM) riboswitches<italic>bhmT,mmuM>, and<italic>metY>. The proteins encoded by these genes were up to 33 times more abundant as DMSP became limiting. Their predicted function is to shunt all available sulfur to methionine. The secondary response, observed during sulfur-limited stationary phase, was a 6- to 10-fold increase in the transcription of the heme<italic>c>shuttle-encoding gene<italic>ccmC>and two small genes of unknown function (<italic>SAR11_1163italic>and>SAR11_1164italic>). This bacterium’s strategy for coping with sulfur stress appears to be intracellular redistribution to support methionine biosynthesis rather than increasing organosulfur import. Many of the genes and SAM riboswitches involved in this response are located in a hypervariable genome region (HVR). One of these HVR genes,<italic>ordL>, is located downstream from a conserved motif that evidence suggests is a novel riboswitch.

IMPORTANCE“<italic>Ca

Martensitic phase transitions in Co-0.85 at % Fe

International Nuclear Information System (INIS)

Prem, M.

1997-12-01

Co-0.85at%Fe shows the two martensitic phase transitions hcp-dhcp and dhcp-fcc. The lattice dynamics of Co-0.85at%Fe was investigated by the means of inelastic neutron scattering at a series of temperatures up to 750K in order to understand the two martensitic phase transitions of this system. In all of the measured phonon branches anomalies were neither found near the hcp-dhcp phase transition nor going through the dhcp-fcc transition. Lattice-parameter scans were performed through the whole temperature range. Diffuse neutron scattering revealed a lattice parameter shift between the dhcp and fcc phase of ∼0.4 % measured at the same temperature. This was possible because the system shows a wide temperature hysteresis at the two phase transitions. In the temperature region of coexistence of dhcp and fcc phase diffuse satellites arose near the (111)fcc Bragg peak (which is equivalent to the (00.2)dhcp peak). Their intensity varied in accordance to the volume fraction of the phases but vanished on changing wavelength. The elastic measurements were performed at the Austrian triple axis spectrometer VALSE located at the Laboratoire Leon Brillouin (LLB) in Saclay (F); the inelastic measurements were performed at the spectrometers IN3 and INS of the Institute Laue Langevin (ILL) in Grenoble (F). (author)

Absolute M1 and E2 Transition Probabilities in 2{sup 33}U

Energy Technology Data Exchange (ETDEWEB)

Malmskog, S G; Hoejeberg, M

1967-08-15

Using the delayed coincidence technique, the following half lives have been determined for different excited states in {sup 233}U: T{sub 1/2} (311.9 keV level) = (1.20 {+-} 0.15) x 10{sup -10} sec, T{sub 1/2} (340.5 keV level) = (5.2 {+-} 1.0) x 10{sup -11} sec, T{sub 1/2} (398.6 keV level) = (5.5 {+-} 2.0) x 10{sup -11} sec and T{sub 1/2} (415.8 keV level) < 3 x 10{sup -11}sec. From these half life determinations, together with earlier known electron intensities and conversion coefficients, 22 reduced B(Ml) and B(E2) transition probabilities (including 9 limits) have been deduced. The rotational transitions give information on the parameters {delta} and (g{sub K} - g{sub R}) . The experimental M1 and E2 transition rates between members of different bands have been analysed in terms of the predictions of the Nilsson model, taking also pairing correlations and Coriolis coupling effects into account.

Evaluating background noise: Assessing off-site data from field surveys around the Italic sanctuary of S. Giovanni in Galdo, Molise, Italy

NARCIS (Netherlands)

Waagen, J.

2014-01-01

This study demonstrates the potential of intensive sampling and off-site analyses to identify evidence of human activity in the past using the off-site data collected around the Italic sanctuary of S. Giovanni in Galdo, Molise, Italy. Rather than employing general and monocausal explanatory

The stability boundary of group-III transition metal diboride ScB 2 (0 0 0 1) surfaces

Science.gov (United States)

Zhao, Hui; Qin, Na

2012-01-01

Experimental observations and theoretical investigations exhibit that a group-IV(V) transition metal diboride (0 0 0 1) surface is terminated with a 1 × 1 TM(B) layer. As to a group-III transition metal diboride, we have investigated the stability boundary of ScB2 (0 0 0 1) surfaces using first principles total energy plane-wave pseudopotential method based on density functional theory. The Mulliken charge population analysis shows that Sc atoms in the second layer cannot provide B atoms in the first layer with sufficient electrons to form a complete graphene-like boron layer. We also found that the charge transfer between the first and the second layer for the B-terminated surface is more than that for Sc-terminated surface. It elucidates the reason that the outermost interlayer spacing contract more strongly in the B-terminated surface than in the Sc-terminated surface. The surface energies of both terminated ScB2 (0 0 0 1) surfaces as a function of the chemical potential of B are also calculated to check the relative stability of the two surface structures.

M1 transitions in the (sdg) boson model

Science.gov (United States)

Kuyucak, S.; Morrison, I.

1988-03-01

Using the {1}/{N} expansion technique we derive expressions for β→g, γ→g and γ→γ M1 transitions in a general boson model. The M1 matrix elements in the sdg-boson model are similar in form to those in the neutron-proton IBM. Comparisons are made to some selected M1 data exhibiting collective character.

M1 transitions in the (sdg) boson model

International Nuclear Information System (INIS)

Kuyucak, S.; Tuebingen Univ.; Morrison, I.

1988-01-01

Using the 1/N expansion technique we derive expressions for β → g, γ → g and γ → γ M1 transitions in a general boson model. The M1 matrix elements in the sdg-boson model are similar in form to those in the neutron-proton IBM. Comparisons are made to some selected M1 data exhibiting collective character. (orig.)

New transition phenomena in a long discharge on TRIAM-1M

International Nuclear Information System (INIS)

Hanada, K.; Itoh, S.; Nakamura, K.; Zushi, H.; Sakamoto, M.; Jotaki, E.; Hasegawa, M.; Kawasaki, S.; Nakashima, H.; Pan, Y.D.

2001-01-01

Abstract Enhancement of current drive (ECD) efficiency mode, which is characterized by the spontaneous increase of current drive efficiency, η CD , from 0.3-0.4x10 19 A/Wm -2 to 0.7-1.0x10 19 A/Wm -2 , is observed in long pure lower hybrid current drive (LHCD) plasmas on TRIAM-1M. The energy confinement time is also improved due to the increase of line averaged electron density, ion and electron temperatures. The current drive efficiency is proportional to the electron density. The transition to ECD mode occurs at a critical density, which slightly depends on the refractive index to the toroidal direction, N parallel of the injected wave. (author)

First HIBP Measurement of Plasma Potential During the H-Mode Transition on the TUMAN-3M Tokamak

International Nuclear Information System (INIS)

Askinazi, L.G.; Golant, V.E.; Kornev, V.A.; Lebedev, S.V.; Shevkin, E.A.; Tukachinsky, A.S.; Zhubr, N.A.; Chmyga, A.A.; Dreval, N.B.; Khrebtov, S.M.; Komarov, A.S.; Krupnik, L.I.; Oost, G. van; Tendler, M.

2003-01-01

The difficulty of Heavy Ion Beam Probe (HIBP) application on the TUMAN-3M (R=0.53m, a=0.22m, BT=0.8T, Ip=140kA, Te=0.5keV, n<4 1019m-3) -- significant toroidal shift of beam trajectory -- is caused by high ratio of poloidal field to toroidal one. Strong UV radiation from the plasma loads the energy analyzer's detector and complicates the problem even more. This paper presents the results of first measurement of plasma potential evolution in the discharges performed in ohmic H-mode using 80 keV K+ beam and a Proca-Green secondary ion energy analyzer. Spatial region covered by the diagnostic in the experiments discussed was 0< r<0.6a. Spatial scan was performed utilizing the toroidal field decrease due to capacity power supply battery discharge. The change in plasma potential of the order of 100V has been measured during the H-mode formation. The potential in core plasma (r<0.6a) starts to change simultaneously with L-H transition, and than changes during ∼6-8ms after the transition. Thus, the potential changes rather slowly in a comparison with L-H transition timescale (∼2ms for TUMAN-3M ohmic H-mode). Possible explanation to the slow change in central plasma potential may be a formation of potential well structure at the plasma edge, in which radial electric field changes direction. This kind of structure is beneficial for the edge turbulent transport suppression because of high |∂Er/∂r|, but not necessary requires a strong change in central plasma potential to occur immediately. The results from microwave reflectometry support this hypothesis

Effect of Sintering Temperature on Microstructure, Chemical Stability and Electrical Properties of Transition Metal or Yb-Doped BaZr0.1Ce0.7Y0.1M0.1O3-δ (M = Fe, Ni, Co and Yb

Directory of Open Access Journals (Sweden)

Behzad eMirfakhraei

2014-03-01

Full Text Available Perovskite-type BaZr0.1Ce0.7Y0.1M0.1O3-δ (M = Fe, Ni, Co and Yb (BZCY-M oxides were synthesized using the conventional solid-state reaction method at 1350-1550 oC in air in order to investigate the effect of dopants on sintering, crystal structure, chemical stability under CO2 and H2S, and electrical transport properties. The formation of the single-phase perovskite-type structure with an orthorhombic space group Imam was confirmed by Rietveld refinement using powder X-ray diffraction (PXRD for the Fe, Co, Ni and Yb-doped samples. The BZCY-Co and BZCY-Ni oxides show a total electrical conductivity of 0.01 and 8 × 10-3 Scm-1 at 600 oC in wet H2 with an activation energy of 0.36 and 0.41 eV, respectively. Scanning electron microscopy (SEM and energy-dispersive X-ray analysis (EDX revealed Ba and Co rich secondary phase at the grain-boundaries, which may explain the enhancement in the total conductivity of the BZCY-Co. However, ex-solution of Ni at higher sintering temperatures, especially at 1550 oC, decreases the total conductivity of the BZCY-Ni material. The Co and Ni dopants act as a sintering aid and form dense pellets at a lower sintering temperature of 1250 oC. The Fe, Co and Ni-doped BZCY-M samples synthesized at 1350 oC show stability in 30 ppm H2S/H2 at 800 oC, and increasing the firing temperature to 1550 oC, enhanced the chemical stability in CO2 / N2 (1: 2 at 25-900 oC. The BZCY-Co and Ni compounds with high conductivity in wet H2 could be considered as possible anodes for intermediate temperature solid oxide fuel cells (IT-SOFCs.

Phase transitions and optical characterization of lead-free piezoelectric (K0.5Na0.5)0.96Li0.04(Nb 0.8Ta0.2)O3 thin films

KAUST Repository

Yao, Yingbang

2013-06-01

Lead-free piezoelectric thin films, (K0.5Na0.5) 0.96Li0.04(Nb0.8Ta0.2)O 3, were epitaxially grown on MgO(001) and Nb-doped SrTiO 3(001) substrates using pulsed laser deposition. The optimum deposition temperature was found to be 600 C. Two types of in-plane orientations were observed in the films depending on the substrates used. The transmittance and photoluminescence spectra as well as the dielectric and ferroelectric properties of the films were measured. The measured band-gap energy was found to be decreased with the deposition temperature. The dielectric constant decreased from 550 to 300 as the frequency increased from 100 Hz to 1 MHz. The measured remnant polarization and coercive field were 4 μC/cm2 and 68 kV/cm, respectively. The phase transitions of the films were studied by Raman spectroscopy. Two distinct anomalies originating from the cubic-to-tetragonal (TC-T ~ 300 C) and tetragonal-to-orthorhombic (TT-O ~ 120 C) phase transitions were observed. Our results show that Raman spectroscopy is a powerful tool in identifying the phase transitions in ferroelectric thin films. © 2013 Elsevier B.V.

Phase transition in the (Li 0.5-( x/2) K 0.5-( x/2) Cs x) 2SO 4 system

Science.gov (United States)

Hamed, A. E.; El-Aziz, Y. M. Abd.; Madi, N. K.; Kassem, M. E.

1995-12-01

Phase transition in the (Li 0.5-( x/2) K 0.5-( x/2) Cs x) 2SO 4 system was studied by measuring the specific heat at constant pressure, C p, as a function of temperature in the temperature range 300-800 K. For non-zero values of X ( X = 0.2%, 0.5%, 1% and 2%) the critical behaviour of the phase transition was found to change considerably compared with that of X = 0 or pure LiKSO 4. The observed change in the phase transition with increase of Cs 2SO 4 content ( X) was accompanied by a decrease in the thermodynamic parameters: the value of the specific heat at the transition point (Δ C P) max, the transition temperature, T1, and the value of the energy of ordering. The results were interpreted within the Landau thermodynamic theory of the phase transition.

Evaluation of genotypic variation of broccoli (Brassica oleracea var. italic) in response to selenium treatment.

Science.gov (United States)

Ramos, Silvio J; Yuan, Youxi; Faquin, Valdemar; Guilherme, Luiz Roberto G; Li, Li

2011-04-27

Broccoli (Brassica oleracea var. italic) fortified with selenium (Se) has been promoted as a functional food. Here, we evaluated 38 broccoli accessions for their capacity to accumulate Se and for their responses to selenate treatment in terms of nutritional qualities and sulfur gene expresion. We found that the total Se content varied with over 2-fold difference among the leaf tissues of broccoli accessions when the plants were treated with 20 μM Na(2)SeO(4). Approximately half of total Se accumulated in leaves was Se-methylselenocysteine and selenomethionine. Transcriptional regulation of adenosine 5'-phosphosulfate sulfurylase and selenocysteine Se-methyltransferase gene expression might contribute to the different levels of Se accumulation in broccoli. Total glucosinolate contents were not affected by the concentration of selenate application for the majority of broccoli accessions. Essential micronutrients (i.e., Fe, Zn, Cu, and Mn) remained unchanged among half of the germplasm. Moreover, the total antioxidant capacity was greatly stimulated by selenate in over half of the accessions. The diverse genotypic variation in Se, glucosinolate, and antioxidant contents among accessions provides the opportunity to breed broccoli cultivars that simultaneously accumulate Se and other health benefit compounds.

Housefly Larva Vermicomposting Efficiently Attenuates Antibiotic Resistance Genes in Swine Manure, with Concomitant Bacterial Population Changes

Energy Technology Data Exchange (ETDEWEB)

Wang, Hang; Li, Hongyi; Gilbert, Jack A.; Li, Haibo; Wu, Longhua; Liu, Meng; Wang, Liling; Zhou, Qiansheng; Yuan, Junxiang; Zhang, Zhijian; Goodrich-Blair, H.

2015-08-21

Manure from swine treated with antimicrobials as feed additives is a major source for the expansion of the antibiotic resistance gene (ARG) reservoir in the environment. Vermicomposting via housefly larvae (Musca domestica) can be efficiently used to treat manure and regenerate biofertilizer, but few studies have investigated its effect on ARG attenuation. Here, we tracked the abundances of 9 ARGs and the composition and structure of the bacterial communities in manure samples across 6 days of full-scale manure vermicomposting. On day 6, the abundances of genes encoding tetracycline resistance [<italic>tet(M),tet(O),tet>(Q), and<italic>tet>(W)] were reduced (<italic>P>< 0.05), while those of genes encoding sulfonamide resistance (<italic>sul1italic>and>sul2italic>) were increased (<italic>P>< 0.05) when normalized to 16S rRNA. The abundances of tetracycline resistance genes were correlated (<italic>P>< 0.05) with the changing concentrations of tetracyclines in the manure. The overall diversity and richness of the bacteria significantly decreased during vermicomposting, accompanied by a 100 times increase in the relative abundance ofFlavobacteriaceaespp. Variations in the abundances of ARGs were correlated with the changing microbial community structure and the relative abundances of the familyRuminococcaceae, classBacilli, or phylumProteobacteria. Vermicomposting, as a waste management practice, can reduce the overall abundance of ARGs. More research is warranted to assess the use of this waste management practice as a measure to

Energetic M1 transitions as a probe of nuclear collectivity at high temperatures

International Nuclear Information System (INIS)

Baktash, C.

1987-01-01

At ORNL, we have recently utilized the Spin Spectrometer setup to investigate the differential effects of increasing spin and excitation energy on nuclear shape and collectivity in 158 Yb. Along the yrast line of this and other N = 88 nuclei, weakly prolate shapes gradually give way to triaxial, and then finally to non-collective oblate shapes as the spin approaches 40 h-bar. However, above the yrast line, large deformation and collectivity once again sets in. This is evidenced by the emergence of a broad quadrupole structure (E/sub γ/ ≅ 1.2 MeV) in the continuum gamma-ray spectra that grows with increasing temperature. The short (sub ps) lifetimes of these transitions attest to the collective nature of these structures. The emergence and growth of the quadrupole structure at high excitation energies is closely correlated with the appearance of energetic (E/sub γ/ ≅ 2.5 MeV), fast M1 transitions which form another broad structure in the continuum spectra. From the centroid of the M1 bump, a quadrupole deformation parameter of 0.35 is inferred. Because of this sensitivity, these energetic M1 transitions provide a unique probe of nuclear shape in the excitation energy range of ≅ 3 to 10 MeV. 6 refs., 2 figs

Q2 Dependence of Quadrupole Strength in the gamma*p-->Delta+(1232) --> p pi0 Transition

International Nuclear Information System (INIS)

Volker Burkert; Kyungseon Joo; Lee Smith; Ralph Minehart

2002-01-01

Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the Q 2 dependence of the magnetic (M 1+ ), electric (E 1+ ), and scalar (S 1+ ) multipoles in the γ*p → Δ + (1232) → pπ 0 transition. New precision measurements of the ratios E 1+ /M 1+ and S 1+ /M 1+ are reported here over the range Q 2 = 0.4-1.8 GeV 2 . Results are best described by recent unitary models in which the pion cloud plays a dominant role

The structure of 0- to 0.2-m.y.-old oceanic crust at 9°N on the East Pacific Rise from expanded spread profiles

Science.gov (United States)

Vera, E. E.; Mutter, J. C.; Buhl, P.; Orcutt, J. A.; Harding, A. J.; Kappus, M. E.; Detrick, R. S.; Brocher, T. M.

1990-09-01

We analyze four expanded spread profiles acquired at distances of 0, 2.1, 3.1, and 10 km (0-0.2 m.y.) from the axis of the East Pacific Rise between 9° and 10°N. Velocity-depth models for these profiles have been obtained by travel time inversion in the τ-p domain, and by x-t forward modeling using the WKBJ and the reflectivity methods. We observe refracted arrivals that allow us to determine directly the uppermost crustal velocity structure (layer 2A). At the seafloor we find very low Vp and VS/Vp values around 2.2 km/s and ≤ 0.43. In the topmost 100-200 m of the crust, Vp remains low (≤ 2.5 km/s) then rapidly increases to 5 km/s at ˜500 m below the seafloor. High attenuation values (Qp < 100) are suggested in the topmost ˜500 m of the crust. The layer 2-3 transition probably occurs within the dike unit, a few hundred meters above the dike-gabbro transition. This transition may mark the maximum depth of penetration by a cracking front and associated hydrothermal circulation in the axial region above the axial magma chamber (AMC). The on-axis profile shows arrivals that correspond to the bright AMC event seen in reflection lines within 2 km of the rise axis. The top of the AMC lies 1.6 km below the seafloor and consists of molten material where Vp ≈ 3 km/s and VS = 0. Immediately above the AMC, there is a zone of large negative velocity gradients where, on the average, Vp decreases from ˜6.3 to 3 km/s over a depth of approximately 250 m. Associated with the AMC there is a low velocity zone (LVZ) that extends to a distance no greater than 10 km away from the rise axis. At the top of the LVZ, sharp velocity contrasts are confined to within 2 km of the rise axis and are associated with molten material or material with a high percentage of melt which would be concentrated only in a thin zone at the apex of the LVZ, in the axial region where the AMC event is seen in reflection lines. Away from the axis, the transition to the LVZ is smoother, the top of the

Vacancy-induced brittle to ductile transition of W-M co-doped Al3Ti (M=Si, Ge, Sn and Pb).

Science.gov (United States)

Zhu, Mingke; Wu, Ping; Li, Qiulin; Xu, Ben

2017-10-25

We investigated the effect of vacancy formation on brittle (D0 22 ) to ductile (L1 2 -like) transition in Al 3 Ti using DFT calculations. The well-known pseudogap on the density of states of Al 3 Ti migrates towards its Fermi level from far above, via a W - M co-doping strategy, where M is Si, Ge, Sn or Pb respectively. In particular, by a W - M co-doping the underline electronic structure of the pseudogap approaches an octahedral (L1 2 : t 2g , e g ) from the tetragonal (D0 22 : e g , b 2g , a 1g , b 1g ) crystal field. Our calculations demonstrated that (1) a W-doping is responsible for the close up of the energy gap between a 1g and b 1g so that they tend to merge into an e g symmetry, and (2) all M-doping lead to a narrower gap between e g and b 2g (moving towards a t 2g symmetry). Thus, a brittle to ductile transition in Al 3 Ti is possible by adopting this W - M co-doping strategy. We further recommend the use of W-Pb co-doped Al 3 Ti to replace the less anodic Al electrode in Al-battery, due to its improved ductility and high Al diffusivity. Finally this study opens a new field in physics to tailor mechanical properties by manipulating electron energy level(s) towards higher symmetry via vacancy optimization.

Critical end point of the first-order ferromagnetic transition in a Sm{sub 0.55}(Sr{sub 0.5}Ca{sub 0.5}){sub 0.45}MnO{sub 3} single crystal

Energy Technology Data Exchange (ETDEWEB)

Radheep, D. Mohan [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirappalli 620 024 (India); Sarkar, P. [Department of Physics, Serampore College, Serampore 712 201 (India); Arumugam, S. [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirappalli 620 024 (India); Suryanarayanan, R. [Laboratoire de Physico-Chimie de l' Etat Solide, ICMMO, CNRS, UMR8182, Universite Paris-Sud, 91405 Orsay (France); Mandal, P., E-mail: prabhat.mandal@saha.ac.in [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Calcutta 700 064 (India)

2014-09-01

We report on the magnetic field (H) and hydrostatic pressure (P) dependence of the order of the ferromagnetic (FM) to paramagnetic phase transition in a Sm{sub 0.55}(Sr{sub 0.5}Ca{sub 0.5}){sub 0.45}MnO{sub 3} single crystal. At ambient condition, the system exhibits a first-order FM transition at T{sub C}≈82K (in heating cycle) with strong thermal hysteresis (∼13 K). The application of external H and P increases T{sub C}, suppresses the hysteresis width, and thus weakens the first-order nature of the transition. Our analysis reveals that the hysteresis vanishes and the first-order FM transition becomes a crossover above a critical magnetic field H{sub cr}≈11.5T. The value of H{sub cr} is highest among the manganite family, although the first-order nature of the FM transition is believed to be strongest in Eu{sub 1−x}Sr{sub x}MnO{sub 3}(x≈0.45). - Highlights: • System shows a strong first-order ferromagnetic to paramagnetic phase transition. • Extremely sharp metal–insulator transition at around 82 K. • The value of critical magnetic field at which first-order transition becomes a crossover is highest among manganites. • The nature of transition is sensitive to external perturbations such as magnetic field and pressure.

Second order magnetic phase transition and scaling analysis in iron doped manganite La{sub 0.7}Ca{sub 0.3}Mn{sub 1−x}Fe{sub x}O{sub 3} compounds

Energy Technology Data Exchange (ETDEWEB)

Ginting, Dianta [Department of Applied Physics and Institute of Natural Sciences, Kyung Hee University, Yong-in 446-701 (Korea, Republic of); Nanto, Dwi [Physics Education, Syarif Hidayatullah State Islamic University, Jakarta 15412 (Indonesia); Denny, Yus Rama [Department of Electrical Engineering, University of Sultan Ageng Tirtayasa, Banten 42435 (Indonesia); Tarigan, Kontan [Department of Mechanical Engineering, Mercu Buana University, Jakarta-Barat, Jakarta 11650 (Indonesia); Hadi, Syamsul [Department of Mechanical Engineering, State Polytechnic of Malang, East Java 65100 (Indonesia); Ihsan, Mohammad [PSTBM-BATAN, Kawasan Puspiptek Serpong, Tangerang Selatan, Banten 15314 (Indonesia); Institute of Electronic Materials, University of Wollongong, Wollongong NSW 2522 (Australia); Rhyee, Jong-Soo, E-mail: jsrhyee@khu.ac.kr [Department of Applied Physics and Institute of Natural Sciences, Kyung Hee University, Yong-in 446-701 (Korea, Republic of)

2015-12-01

We investigated magnetic properties of La{sub 0.7}Ca{sub 0.3}Mn{sub 1−x}Fe{sub x}O{sub 3} (x=0.09 and 0.11) compounds in terms of isothermal magnetization analysis and scaling behavior with various critical exponents. From the Landau theory of magnetic phase transition, we found that the paramagnetic to ferromagnetic phase transition in La{sub 0.7}Ca{sub 0.3}Mn{sub 1−x}Fe{sub x}O{sub 3} (x=0.09 and 0.11) compounds is the type of second order magnetic transition (SOMT), which contrary to the first order magnetic transition (FOMT) for low Fe-doped compounds (x<0.09) in previous reports. When we investigate the critical behavior of the compounds near T=T{sub c} by the modified Arrott plot, Kouvel–Fisher plots, and critical isothermal analysis, the estimated critical exponents β, γ, and δ are in between the theoretically predicted values for three-dimensional Heisenberg and mean-field interaction models. It is noteworthy that the scaling relations are obeyed in terms of renormalization magnetization m=ε{sup −β}M(H,ε) and renormalized field h=|ε|{sup β+γ}H. Temperature-dependent effective exponents β{sub eff} and γ{sub eff} correspond to the ones of disordered ferromagnets. It is shown that the magnetic state of the compounds is not fully described by the conventional localized-spin interaction model because the ferromagnetic interaction has itinerant character by increasing Fe-doping concentration. - Highlights: • The ferromagnetic phase transition is of second order in La{sub 0.7}Ca{sub 0.3}Mn{sub 1−x}Fe{sub x}O{sub 3}. • The critical exponents are in between the 3D Heisenberg and mean-field models. • The ferromagnetic interaction becomes more itinerant by Fe-doping.

Photoemission spectroscopy of the charge-ordering transition in Pr0.5Sr0.5MnO3

International Nuclear Information System (INIS)

Chainani, A.; Kumigashira, H.; Takahashi, T.; Tomioka, Y.; Kuwahara, H.; Tokura, Y.

1996-01-01

In this paper, the electronic structure of the magnetite Pr 0.5 Sr 0.5 MnO 3 across the charge ordering transition is studied using temperature-dependent photoemission spectroscopy. Ultra-violet photoemission spectroscopy have been performed as a function of temperature (25-300K) to investigate the changes in the single-particle density of states across the metal-nonmetal and the para-ferro transitions

Assignment of multipolarity for ΔI= 0 γ transitions from polarization measurements

International Nuclear Information System (INIS)

Ali, Sajad; Rajbanshi, S.; Chattopadhyay, S.

2017-01-01

It is well known that the determination of the polarization for the γ transition will lead to the unique spin-parity assignments of the nuclear states. The electric and magnetic nature of the γ-rays are distinguishes by the direction of the electric vector of electromagnetic radiation with respect to the beam detector plane. The difference between the perpendicular and parallely scattered events due to the Compton scattering depends on the direction of electric vector of the emitted γ radiation. The difference is positive for electric type transition and negative for magnetic type transitions while for a mixed transitions it is almost zero. However, for the ΔI =0 γ transitions it can be shown theoretically that the difference is positive for magnetic type of transitions and negative for electric type of transitions. This opposite results of the polarization asymmetry for the ΔI =0 γ transitions may sometimes resulted in different assignments of the nuclear states

Octupole correlations in neutron-rich {sup 143,145}Ba and a type of superdeformed band in {sup 145}Ba

Energy Technology Data Exchange (ETDEWEB)

Zhu, S.J.; Wang, M.G.; Long, G.L.; Zhu, L.Y.; Gan, C.Y.; Yang, L.M.; Sakhaee, M.; Li, M.; Deng, J.K. [Physics Department, Tsinghua University, Beijing 100084, Peoples Republic of (China); Zhu, S.J.; Hamilton, J.H.; Ramayya, A.V.; Jones, E.F.; Hwang, J.K.; Zhang, X.Q.; Gore, P.M.; Peker, L.K.; Drafta, G.; Babu, B.R.; Deng, J.K.; Ginter, T.N.; Beyer, C.J.; Kormicki, J.; Ter-Akopian, G.M.; Daniel, A.V. [Physics Department, Vanderbilt University, Nashville, Tennessee 37235 (United States); Zhu, S.J.; Ter-Akopian, G.M.; Daniel, A.V. [Joint Institute for Heavy Ion Research, Oak Ridge, Tennessee 37831 (United States); Ma, W.C. [Physics Department, Mississippi State University, Mississippi 39762 (United States); Cole, J.D.; Aryaeinejad, R.; Drigert, M.W. [Idaho National Engineering Laboratory, Idaho Falls, Idaho 83415 (United States); Rasmussen, J.O.; Asztalos, S.; Lee, I.Y.; Macchiavelli, A.O.; Chu, S.Y.; Gregorich, K.E.; Mohar, M.F. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Ter-Akopian, G.M.; Daniel, A.V.; Oganessian, Y.T.; Kliman, J. [Flerov Laboratory for Nuclear Reactions, Joint Institute for Nuclear Research, Dubna (Russia); Donangelo, R. [Universidade Federal do Rio de Janeiro, Caixa Postal 68528, RG (Brazil); Stoyer, M.A.; Lougheed, R.W.; Moody, K.J.; Wild, J.F. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Prussin, S.G. [Nuclear Engineering Department, University of California at Berkeley, Berkeley, California 94720 (United States); Kliman, J. [Institute of Physics, SASc, Dubravskacesta 9, 84228 Bratislava (Slovakia); Griffin, H.C. [University of Michigan, Ann Arbor, Michigan 48104 (United States)

1999-11-01

High spin states in neutron-rich odd-{ital Z} {sup 143,145}Ba nuclei have been investigated from the study of prompt {gamma} rays in the spontaneous fission of {sup 252}Cf by using {gamma}-{gamma}- and {gamma}-{gamma}-{gamma}- coincidence techniques. Alternating parity bands are identified for the first time in {sup 145}Ba and extended in {sup 143}Ba. A new side band, with equal, constant dynamic, and kinetic moments of inertia equal to the rigid body value, as found in superdeformed bands, is discovered in {sup 145}Ba. Enhanced E1 transitions between the negative- and positive-parity bands in these nuclei give evidence for strong octupole deformation in {sup 143}Ba and in {sup 145}Ba. These collective bands show competition and coexistence between symmetric and asymmetric shapes in {sup 145}Ba. Evidence is found for crossing M1 and E1 transitions between the s=+i and s={minus}i doublets in {sup 143}Ba. {copyright} {ital 1999} {ital The American Physical Society}

Micro-Raman study of the microheterogeneity in the MA-MC phase transition in 0.67PbMg1/3Nb2/3O3-0.33PbTiO3 single crystal

KAUST Repository

Yang, Y.; Zhang, L. Y.; Zhu, K.; Liu, Y. L.

2011-01-01

Polarized Raman spectroscopy has been employed to investigate the evolution of the microstructure of 0.67PbMg1/3Nb2/3O3-0.33PbTiO3 (PMN-33%PT) single crystal in the temperature range from −195 to 300 °C. The M A-M C-cubic transition sequence

ω→π0γ* and ϕ→π0γ* transition form factors in dispersion theory

Science.gov (United States)

Schneider, Sebastian P.; Kubis, Bastian; Niecknig, Franz

2012-09-01

We calculate the ω→π0γ* and ϕ→π0γ* electromagnetic transition form factors based on dispersion theory, relying solely on a previous dispersive analysis of the corresponding three-pion decays and the pion vector form factor. We compare our findings to recent measurements of the ω→π0μ+μ- decay spectrum by the NA60 collaboration, and strongly encourage experimental investigation of the Okubo-Zweig-Iizuka forbidden ϕ→π0ℓ+ℓ- decays in order to understand the strong deviations from vector-meson dominance found in these transition form factors.

Temperature-dependent Raman and ultraviolet photoelectron spectroscopy studies on phase transition behavior of VO{sub 2} films with M1 and M2 phases

Energy Technology Data Exchange (ETDEWEB)

Okimura, Kunio, E-mail: okifn@keyaki.cc.u-tokai.ac.jp; Hanis Azhan, Nurul [Graduate School of Engineering, Tokai University, Hiratsuka 259-1292 (Japan); Hajiri, Tetsuya [UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585 (Japan); Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Kimura, Shin-ichi [UVSOR Facility, Institute for Molecular Science, Okazaki 444-8585 (Japan); Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871 (Japan); Zaghrioui, Mustapha; Sakai, Joe [GREMAN, UMR 7347 CNRS, Université François Rabelais de Tours, Parc de Grandmont, 37200 Tours (France)

2014-04-21

Structural and electronic phase transitions behavior of two polycrystalline VO{sub 2} films, one with pure M1 phase and the other with pure M2 phase at room temperature, were investigated by temperature-controlled Raman spectroscopy and ultraviolet photoelectron spectroscopy (UPS). We observed characteristic transient dynamics in which the Raman modes at 195 cm{sup −1} (V-V vibration) and 616 cm{sup −1} (V-O vibration) showed remarkable hardening along the temperature in M1 phase film, indicating the rearrangements of V-V pairs and VO{sub 6} octahedra. It was also shown that the M1 Raman mode frequency approached those of invariant M2 peaks before entering rutile phase. In UPS spectra with high energy resolution of 0.03 eV for the M2 phase film, narrower V{sub 3d} band was observed together with smaller gap compared to those of M1 phase film, supporting the nature of Mott insulator of M2 phase even in the polycrystalline film. Cooperative behavior of lattice rearrangements and electronic phase transition was suggested for M1 phase film.

Crystal structure refinements of tetragonal (OH,F)-rich spessartine and henritermierite garnets

Energy Technology Data Exchange (ETDEWEB)

Antao, Sytle M.; Cruickshank, Laura A.

2018-01-30

Cubic garnet (space group Ia\\overline 3 d) has the general formula<italic>X>₃<italic>Y>₂<italic>Z>₃O₁₂, where<italic>X,YandZ>are cation sites. In the tetragonal garnet (space group<italic>I>4₁/<italic>acd>), the corresponding cation sites are<italic>X>1 and<italic>X>2,<italic>Y>, and<italic>Z>1 and<italic>Z>2. In both space groups only the<italic>Y>site is the same. The crystal chemistry of a tetragonal (OH,F)-rich spessartine sample from Tongbei, near Yunxiao, Fujian Province, China, with composition^<italic>X>(Mn_2.82Fe^{2+}_{0.14}Ca_0.04)_Σ3^<italic>Y>{Al_1.95Fe^{3+}_{0.05}}_Σ2^<italic>Z>[(SiO₄)_2.61(O₄H₄)_0.28(F₄)_0.11]_Σ3(Sps₉₄Alm₅Grs₁) was studied with single-crystal X-ray diffraction and space group<italic>I>4₁/<italic>acd>. The deviation of the unit-cell parameters from cubic symmetry is small [<italic>a>= 11.64463(1),<italic>c>= 11.65481 (2) Å,<italic>c/a>= 1.0009]. Point analyses and back-scattered electron images, obtained by electron-probe microanalysis, indicate a homogeneous composition. The<italic>Z>2 site is fully occupied, but the<italic>Z>1 site contains vacancies. The occupied<italic>Z>1 and<italic>Z>2 sites with Si atoms are surrounded by four O atoms, as in anhydrous cubic garnets. Pairs of split sites are O1 with F11 and O2 with O22. When the<italic>Z>1 site is vacant, a larger [(O₂H₂)F₂] tetrahedron is formed by two OH and two F anions in the O22 and F11 sites, respectively. This [(O₂

Diode-pumped laser amplifiers: application to 0.946 {mu}m Nd:YAG

Energy Technology Data Exchange (ETDEWEB)

Barnes, Norman P [NASA Langley Research Center, Hampton, VA 23681 (United States); Axenson, Theresa J [Science and Technology Corporation, 10 Basil Sawyer Drive, Hampton, VA 23666 (United States); Jr, Donald J Reichle [NASA Langley Research Center, Hampton, VA 23681 (United States); Walsh, Brian M [NASA Langley Research Center, Hampton, VA 23681 (United States)

2003-03-14

A diode-pumped laser amplifier model is derived from first principles and applied to a Nd:YAG amplifier operating on the {sup 4}F{sub 3/2} to {sup 4}I{sub 9/2} transition at 0.946 {mu}m. The effects of amplified spontaneous emission are included in the model and the addition of this effect is shown to produce better agreement with the data. The amplifier model includes effects of the transverse and longitudinal variation of the pump beam, transverse and longitudinal variation of the probe beam, and multiple passes of the probe beam. Experimental results obtained with a quasi four-level Nd:YAG amplifier operating at 0.946 {mu}m are used to validate the model. The amplifier was evaluated as a function of the pump energy, the probe energy, the probe beam radius, the pulse repetition frequency and the temperature. For all of the experimental conditions, the experimental results and the model agree.

M1 and E2 transitions in the ground-state configuration of atomic ...

Indian Academy of Sciences (India)

have calculated the forbidden transition (M1 and E2) parameters such as transition energies, log- arithmic weighted ... Keywords. Forbidden transitions; transition energies; logarithmic weighted oscillator strengths; .... optimizing the energy function based on the non-relativistic Hamiltonian of an atom,. HNR = N. ∑ j=1. (12∇ ...

Gigantic perpendicular magnetic anisotropy of heavy transition metal cappings on Fe/MgO(0 0 1)

Science.gov (United States)

Taivansaikhan, P.; Odkhuu, D.; Rhim, S. H.; Hong, S. C.

2017-11-01

Effects of capping layer by 5d transition metals (TM = Hf, Ta, W, Re, Os, Ir, Pt, and Au) on Fe/MgO(0 0 1), a typical magnetic tunneling junction, are systematically investigated using first-principles calculation for magnetism and magnetocrystalline-anisotropy (MCA). The early TMs having less than half-filled d bands favor magnetization antiparallel to Fe, whereas the late TMs having more than half-filled d bands favor parallel, which is explained in the framework of kinetic exchange energy. The Os capping, isovalent to Fe, enhances MCA significantly to gigantic energy of +11.31 meV/cell, where positive contribution is mostly from the partially filled majority d bands of magnetic quantum number of |m| = 1 along with stronger spin-orbit coupling of Os than Fe. Different TM cappings give different MCA energies as the Fermi level shifts according to the valence of TM: Re and Ir, just one valence more or less than Os, have still large PMCA but smaller than the Os. In the W and Pt cappings, valence difference by two, PMCA are further reduced; MCAs are lowered compared to Fe/MgO(0 0 1) by the cappings of the very early TMs (Hf and Ta), while the very late TM (Au) switches sign to in-plane MCA.

An investigation on phase transition behaviors in MgO-doped Pb{sub 0.99}(Zr{sub 0.95}Ti{sub 0.05}){sub 0.98}Nb{sub 0.02}O{sub 3} ferroelectric ceramics by Raman and dielectric measurements

Energy Technology Data Exchange (ETDEWEB)

Wang, Junxia, E-mail: wjunxia2002@163.com [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Wang, Genshui; Chen, Xuefeng [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Hu, Zhigao [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai 200241 (China); Nie, Hengchang; Cao, Fei [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Dong, Xianlin, E-mail: xldong@mail.sic.ac.cn [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

2015-03-15

Highlights: • The phase transition behaviors were strongly dependent on MgO concentration. • The F{sub R(LT)}–F{sub R(HT)} phase transition temperature obviously shifted toward a lower temperature with increasing MgO addition. • The F{sub R(HT)}–cubic paraelectric (P{sub C}) phase transition changed to a higher temperature with increasing MgO addition. • The distortion of BO{sub 6} oxygen octahedron caused by B-site replacement of Mg{sup 2+} ions is proposed to explain the observed behaviors. • Superior room-temperature pyroelectric properties were obtained in 0.1 wt% MgO-modified PZTN 95/5 ceramics during F{sub R(LT)}–F{sub R(HT)} phase transition. - Abstract: The phase transition behaviors of Pb{sub 0.99}(Zr{sub 0.95}Ti{sub 0.05}){sub 0.98}Nb{sub 0.02}O{sub 3} ferroelectric ceramics doped with different MgO concentrations (0–0.2 wt%) were systematically investigated by Raman and dielectric measurements. Raman results showed that the phase transitions were strongly dependent on MgO concentration. It was found that the low temperature rhombohedral (F{sub R(LT)})–high temperature rhombohedral (F{sub R(HT)}) ferroelectric phase transition shifted toward a lower temperature with increasing MgO concentration up to 0.1 wt%, while the F{sub R(HT)}–cubic paraelectric (P{sub C}) phase transition changed to a higher temperature. The Raman results were in good agreement with phase transition determined by dielectric measurements. Moreover, it was indicated that the changes of Raman active modes were related to distortion of BO{sub 6} octahedra during the phase transitions. Then, the distortion of BO{sub 6} octahedron caused by B-site replacement of Mg{sup 2+} ions was proposed to explain the observed behaviors. In addition, the effects of MgO doping on the dielectric, ferroelectric and pyroelectric properties were also discussed.

Crystallization and X-ray diffraction analysis of the HMG domain of the chondrogenesis master regulator Sox9 in complex with a ChIP-Seq-identified DNA element

Energy Technology Data Exchange (ETDEWEB)

Vivekanandan, Saravanan; Moovarkumudalvan, Balasubramanian; Lescar, Julien; Kolatkar, Prasanna R.

2015-10-30

Sox9 is a fundamental sex-determining gene and the master regulator of chondrogenesis, and is involved in the development of various vital organs such as testes, kidney, heart and brain, and in skeletal development. Similar to other known Sox transcription factors, Sox9 recognizes and binds DNA with the consensus sequence C(T/A)TTG(T/A)(T/A) through the highly conserved HMG domain. Nonetheless, the molecular basis of the functional specificity of Sox9 in key developmental processes is still unclear. As an initial step towards a mechanistic understanding of Sox9 transcriptional regulation, the current work describes the details of the purification of the mouse Sox9 HMG domain (mSox9HMG), its crystallization in complex with a ChIP-Seq-identified FOXP2 promoter DNA element and the X-ray diffraction data analysis of this complex. The mSox9HMG–FOXP2 promoter DNA complex was crystallized by the hanging-drop vapour-diffusion method using 20% PEG 3350 in 200 mM>sodium/potassium phosphate with 100 mM>bis-tris propane at pH 8.5. The crystals diffracted to 2.7 Å resolution and the complex crystallized in the tetragonal space group<italic>P>4₁2₁2, with unit-cell parameters<italic>a=b>= 99.49,<italic>c>= 45.89 Å. Crystal-packing parameters revealed that asymmetric unit contained one mSox9HMG–FOXP2 promoter DNA complex with an estimated solvent content of 64%.

La0⋅ 9Sr0⋅ 1Ga0⋅ 8M0⋅ 2O3–δ (M= Mn, Co, Ni, Cu or Zn ...

Indian Academy of Sciences (India)

Perovskite oxides of the general formula, La0.9Sr0.1Ga0.8M0.2O3– for M = Mn, Co, Ni, Cu and Zn, have been prepared and investigated. All the oxides exhibit high electrical conductivities ( ∼ 10–2 S/cm at 800°C) comparable to that of the best perovskite oxide ion conductor, La0.9Sr0.1Ga0.8Mg0.2O2.85 (LSGM) ( ...

Internal friction and longitudinal modulus behaviour of multiferroic PbZr0.52Ti0.48O3+Ni0.93Co0.02Mn0.05Fe1.95O4-δ particulate composites

International Nuclear Information System (INIS)

Ramana, M Venkata; Sreenivasulu, G; Reddy, N Ramamanohar; Kumar, K V Siva; Murty, B S; Murthy, V R K

2007-01-01

Multiferroic particulate composites with composition xNi 0.93 Co 0.02 Mn 0.5 Fe 1.95 O 4-δ + (1 - x)PbZr 0.52 Ti 0.48 O 3 where the molar fraction x varies as 0, 0.1, 0.2, 0.3, 0.4 and 0.5 were prepared by the conventional ceramic method. The presence of two phases was confirmed by x-ray diffraction and scanning electron microscopy. The temperature variation of the longitudinal modulus (L) and the internal friction (Q -1 ) of these particulate composites at 104.387 kHz was studied in the wide temperature range 30-420 deg. C. The temperature variation of the longitudinal modulus (L) in each composition of these particulate composites showed two abrupt minima. One minimum coincided with the ferroelectric-paraelectric Curie transition temperature (θ E ) and the other with the ferrimagnetic-paramagnetic Curie transition (θ M ) temperature. The internal friction (Q -1 ) measurements also showed two sharp peaks in each composition corresponding to those temperatures where the minima were noticed in the temperature variation of the longitudinal modulus behaviour. The Curie transition temperature of pure ferrite was found to be 560 deg. C. Addition of 10% of ferrite to ferroelectric in a magnetoelectric (ME) composite resulted in a 360 deg. C fall in θ M and with a further increase in ferrite content the θ M variation was found to be very nominal. However, no significant ferroelectric Curie transition temperature shift could be noticed. This behaviour is explained in the light of structural phase transitions in these multiferroic particulate composites. These ME composites were prepared with a view to using them as ME sensors and transducers

Origin of the strain glass transition in Ti_5_0(Ni_5_0_−_x D_x) alloys

International Nuclear Information System (INIS)

Wang, Xu; Shang, Jia-Xiang; Wang, Fu-He; Chen, Yue

2016-01-01

Direct evidence was recently discovered for the unique strain glass (STG) transition, which breaks the local symmetries (PRL 112, 025701 (2014)). To understand the origin of the STG transition, the effects of doping point defects on Ti_5_0(Ni_5_0_−_x D_x) are investigated using first-principle calculations. The experimental observation that STG only exists in a limited range of chemical composition x is successfully rationalized. The mechanisms that correspond to the division of a system into domains with distinctly different compositions are found to be directly related to a dip in the defect formation energy. - Highlights: • The strain glass transition phenomenon in Ti−Ni-based alloys is rationalized. • The electronic-structure origins of the strain glass transition are uncovered. • The separation of domains with different compositions is explained.

Structural Transition and Electrical Properties of (1 - x)(Na0.4K0.1Bi0.5)TiO3- xSrTiO3 Lead-Free Piezoceramics

Science.gov (United States)

Liu, Xing; Zhai, Jiwei; Shen, Bo; Li, Feng; Li, Peng

2017-10-01

(1 - x)(Na0.4K0.1Bi0.5)TiO3- xSrTiO3 (NKBT- xST) ceramics with x = 0 mol.%, 3 mol.%, and 5 mol.% (0ST, 3ST, and 5ST) have been prepared by a conventional solid-state reaction method and their ferroelectric, electrostrictive, and pyroelectric properties investigated. Addition of ST considerably disrupted the long-range ferroelectric order of NKBT- xST ceramics, and the 5ST ceramic exhibited ergodic relaxor phase structure. T FR shifted to near or below room temperature for 5ST ceramic, accompanied by a significant decline of ferroelectricity and enhanced strain. As the temperature approached T FR, the NKBT- xST ceramics exhibited predominantly electrostrictive effect, and the 5ST ceramic presented relatively high electrostrictive coefficient Q 33 of 0.0193 m4/C2. High pyroelectric response was observed for 0ST, 3ST, and 5ST ceramics in the vicinity of T FR due to the large polarization release during the ferroelectric-relaxor structural transition. The 5ST ceramic exhibited high and frequency-insensitive (100 Hz to 10 kHz) room-temperature pyroelectric properties with pyroelectric coefficient p of 656 μC m-2 K-1 and figures of merit F i, F v, and F d reaching 233 pm/V, 0.013 m2/C, and 7.61 μPa-1/2, respectively, indicating that 5ST ceramic is a promising candidate to replace PZT-based ceramics.

The β+ decay of 234Np and other isospin-forbidden 0+ -> 0+ Fermi transitions

International Nuclear Information System (INIS)

Yap, C.T.; Saw, E.L.

1984-01-01

Although experimental values of the Fermi nuclear matrix elements vary widely from about 1x10 -3 to 40x10 -3 for isospin-forbidden 0 + ->0 + β transitions, theoretical calculations using the Coulomb potential and Nilsson wave functions yielded values of Msub(F) in reasonably good agreement, except that of 234 Np. However, our calculation of Msub(F) for this decay as a function of the deformation parameter β yielded a value of Msub(F) in good agreement with experiment for values of β between 0.1 and 0.2. (orig.)

A comparative study of magnetic field induced meta-magnetic transition in nanocrystalline and bulk Pr0.65(Ca0.7Sr0.3)0.35MnO3 compound

Science.gov (United States)

Saha, Suvayan; Das, Kalipada; Bandyopadhyay, Sudipta; Das, I.

2017-06-01

In our present study we highlight the observations of external magnetic field induced sharp meta-magnetic transition in polycrystalline bulk as well as nanocrystalline form of Pr0.65(Ca0.7Sr0.7)0.35MnO3 compound. Interestingly, such behavior persists in the nanoparticles regardless of the disorder broadened transition. However, higher magnetic field is required for nanoparticles having average particle size ∼40 nm for such meta-magnetic transition, which differs from the general trends of the pure charge ordered nano materials. The interfacial strain between the different magnetic domains plays the important role in magnetic isothermal properties of nanoparticles, when the samples are cooled down in different cooling field. Additionally, both the bulk and nanoparticle compounds exhibit spontaneous phase separation and significantly large magnetoresistance at the low temperature region due to the melting of charge ordered fraction.

E0 transitions in {sup 106}Pd: Implications for shape coexistence

Energy Technology Data Exchange (ETDEWEB)

Peters, E.E.; Mynk, M.G. [University of Kentucky, Department of Chemistry, Lexington, KY (United States); Prados-Estevez, F.M.; Chakraborty, A.; Yates, S.W. [University of Kentucky, Department of Chemistry, Lexington, KY (United States); University of Kentucky, Department of Physics and Astronomy, Lexington, KY (United States); Bandyopadhyay, D.; Choudry, S.N.; Crider, B.P.; Kumar, A.; Lesher, S.R.; McKay, C.J.; Orce, J.N.; Scheck, M. [University of Kentucky, Department of Physics and Astronomy, Lexington, KY (United States); Garrett, P.E. [University of Guelph, Department of Physics, Guelph, Ontario (Canada); Hicks, S.F. [University of Dallas, Department of Physics, Irving, TX (United States); Vanhoy, J.R. [United States Naval Academy, Department of Physics, Annapolis, MD (United States); Wood, J.L. [Georgia Institute of Technology, School of Physics, Atlanta, GA (United States)

2016-04-15

Level lifetimes in {sup 106}Pd were measured with the Doppler-shift attenuation method following inelastic neutron scattering, and electric monopole transition strengths between low-lying 2{sup +} states were deduced. The large ρ{sup 2} (E0) values obtained provide evidence for shape coexistence, extending observation of such structures in the N = 60 isotones. Included in these results is the first determination of the E0 transition strength in the Pd nuclei between levels with K = 2. (orig.)

Induced absorption spectra of the infrared fundamental band of molecular deuterium at 77 K: S1( J)+S0( J) transitions

International Nuclear Information System (INIS)

Gillard, P.G.; Prasad, R.D.G.; Reddy, S.P.

1984-01-01

The collision-induced spectra of the fundamental band of normal D 2 in the high frequency region 3200--3700 cm -1 were recorded for gas densities in the range 80--140 amagat at 77 K with a 2 m absorption cell. The contribution to the intensity of the band in this region comes from the high frequency wings of quadrupolar transitions S 1 ( J) and Q 1 ( J)+S 0 ( J) with J = 0 and 1, and from the group of transitions S 1 (2) and Q 1 ( J)+S 0 (2) with J = 0, 1, and 2 as well as from the relatively weaker double rotational transitions of the type S 1 ( J)+S 0 ( J); the latter transitions arise from the intermolecular interaction between the anisotropic component of the polarizability of one of the colliding pairs of molecules and the quadrupole field of the other. The experimental profiles were analyzed by assuming appropriate line shape functions and using the theoretical matrix elements of the quadrupole moment, isotropic polarizability, and anisotropy of polarizability of the D 2 molecule. From this analysis the characteristic half-width parameters delta/sub q/2 and delta/sub q/4 of the quadrupolar transitions and the binary and ternary absorption coefficients of the S 1 ( J)+S 0 ( J) transitions have been obtained. The experimental value of the binary absorption coefficient of S 1 (0)+S 0 (0) is (2.2 +- 0.1) x 10 -9 cm -1 amagat -2 and the corresponding theoretical value is 1.53 x 10 -9 cm -1 amagat -2

K2-139 b: a low-mass warm Jupiter on a 29-d orbit transiting an active K0 V star

Science.gov (United States)

Barragán, O.; Gandolfi, D.; Smith, A. M. S.; Deeg, H. J.; Fridlund, M. C. V.; Persson, C. M.; Donati, P.; Endl, M.; Csizmadia, Sz; Grziwa, S.; Nespral, D.; Hatzes, A. P.; Cochran, W. D.; Fossati, L.; Brems, S. S.; Cabrera, J.; Cusano, F.; Eigmüller, Ph; Eiroa, C.; Erikson, A.; Guenther, E.; Korth, J.; Lorenzo-Oliveira, D.; Mancini, L.; Pätzold, M.; Prieto-Arranz, J.; Rauer, H.; Rebollido, I.; Saario, J.; Zakhozhay, O. V.

2018-04-01

We announce the discovery of K2-139 b (EPIC 218916923 b), a transiting warm-Jupiter (Teq = 547 ± 25 K) on a 29-d orbit around an active (log R^' _HK = -4.46 ± 0.06) K0 V star in K2 Campaign 7. We derive the system's parameters by combining the K2 photometry with ground-based follow-up observations. With a mass of 0.387 _{ - 0.075 } ^ {+ 0.083 }MJ and radius of 0.808 _{ - 0.033 } ^ {+ 0.034 }RJ, K2-139 b is one of the transiting warm Jupiters with the lowest mass known to date. The planetary mean density of 0.91 _{ - 0.20} ^ { + 0.24 } g cm-3can be explained with a core of ˜50 M⊕. Given the brightness of the host star (V = 11.653 mag), the relatively short transit duration (˜5 h), and the expected amplitude of the Rossiter-McLaughlin effect (˜25m s-1), K2-139 is an ideal target to measure the spin-orbit angle of a planetary system hosting a warm Jupiter.

Meson-exchange enhancement of the first forbidden $0^{+} \\leftrightarrow 0^{-} \\beta$-transitions

CERN Multimedia

2002-01-01

In the frame of the standard model of the weak interaction, it has been suggested by Kubodera, Delorme and Rho, that pion exchange should have a large effect on the rank-zero time-like component of the axial current A$_{0}$. The best case for the study of A$ _{0}$ is $0^{-} \\leftrightarrow 0^{+} \\beta$-decay since in this process only rank zero matrix elements of the time-like and space-like components of the axial current contribute to the transition rate. $0^{-} \\leftrightarrow 0^{+}$ decays have been studied in the vicinity of doubly closed-shell nuclei such as $^{16}$O, $^{96}$Zr, and $^{208}$Pb where s$_{1/2} \\leftrightarrow$ p$_{1/2}$ matrix elements were involved. In these cases, the meson-exchange correction to the one-body axial-charge density is significant. ISOLDE offers the possibility to perform sensitive measurements of the $0^{-} \\leftrightarrow 0^{+}$ pseudoscalar decay in nuclei where the p$_{3/2} \\rightarrow$ d$_{3/2}$ matrix elements are involved. We therefore propose a search of the $^{38}...

In-plain electric properties of [CaMnO3/REMO3] (RE=Bi, La M=Fe, Fe0.8Mn0.2) superlattices grown by pulsed laser deposition method

NARCIS (Netherlands)

Iwata, N.; Watabe, Y.; Oikawa, T.; Takase, K.; Huijben, Mark; Inaba, T.; Oshima, K.; Rijnders, Augustinus J.H.M.; Yamamoto, H.

2014-01-01

The [CaMnO3 (CMO)/REMO3] (RE = Bi, La M = Fe, Fe0.8Mn0.2) superlattices show semiconducting behavior with transition temperatures (TEg) of 71, 127, and 151 K in the [CMO/BiFe0.8Mn0.2O3], [CMO/BiFeO3], and [CMO/LaFeO3] superlattices. The formation of a magnetic polaron is expected in the CMO layer of

Effect of hydrostatic pressure on magnetic and magnetocaloric properties in La{sub 0.35}Pr{sub 0.35}Ca{sub 0.3}MnO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Thiyagarajan, R. [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirapalli 620024, Tamil Nadu (India); Esakki Muthu, S. [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirapalli 620024, Tamil Nadu (India); Univ. Grenoble Alpes and CEA, INAC-SPSMS, F-38000 Grenoble (France); Manikandan, K. [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirapalli 620024, Tamil Nadu (India); Arumugam, S., E-mail: sarumugam1963@yahoo.com [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirapalli 620024, Tamil Nadu (India)

2016-01-15

Magnetization of polycrystalline La{sub 0.35}Pr{sub 0.35}Ca{sub 0.3}MnO{sub 3} sample has been measured as a function of temperature (T) and magnetic field (H) under various external hydrostatic pressures (P) up to ~1 GPa. At ambient P, the sample exhibits paramagnetic (PM)–ferromagnetic (FM) transition (T{sub C}) at 167 K and 173 K in cooling and warming cycles respectively under the magnetic field (µ{sub 0}.H) of 0.1 T. It also shows a hysteresis during both temperature- and field- dependence of magnetization measurements at ambient P, suggests the presence of a first-order transition. Moreover, the field dependence of magnetization shows S type field-induced metamagnetic transition (FIMMT) over a temperature range below T{sub C} in the FM state. The application of P in M(T) increases T{sub C} at a rate [dT{sub C}/dP] of 13.9 K/GPa, but the thermally-driven first-order transition is not affected by P. However, the applied P suppresses FIMMT and reduces field-driven first-order transition in the magnetization isotherms [M(H)]below T{sub C}. H increases both magnetic entropy change (∆S{sub m}) and Relative Cooling Power (RCP), whereas the P slightly increases ∆S{sub m}{sup max} and no appreciable change in RCP. These results suggest that H and P can be used as a tool to enhance magnetocaloric values in the phase separated manganites. - Highlights: • At ambient P, La{sub 0.35}Pr{sub 0.35}Ca{sub 0.3}MnO{sub 3} sample shows first-order PM–FM transition. • P increases the T{sub C} at a rate of 13.9 K/GPa, thermal hysteresis is not affected. • P diminishes the field-driven first-order PM–FM transition, suppresses FIMMMT. • H increases ∆S{sub m} and RCP. P slightly increases ∆S{sub m}{sup max}, but no change in RCP by P.

An Improved Transit Measurement for a 2.4 R ⊕ Planet Orbiting A Bright Mid-M Dwarf K2–28

Science.gov (United States)

Chen, Ge; Knutson, Heather A.; Dressing, Courtney D.; Morley, Caroline V.; Werner, Michael; Gorjian, Varoujan; Beichman, Charles; Benneke, Björn; Christiansen, Jessie L.; Ciardi, David; Crossfield, Ian; Howell, Steve B.; Krick, Jessica E.; Livingston, John; Morales, Farisa Y.; Schlieder, Joshua E.

2018-05-01

We present a new Spitzer transit observation of K2–28b, a sub-Neptune (R p = 2.45 ± 0.28 R ⊕) orbiting a relatively bright (V mag = 16.06, K mag = 10.75) metal-rich M4 dwarf (EPIC 206318379). This star is one of only seven with masses less than 0.2 {M}ȯ known to host transiting planets, and the planet appears to be a slightly smaller analogue of GJ 1214b (2.85+/- 0.20 {R}\\oplus ). Our new Spitzer observations were taken two years after the original K2 discovery data and have a significantly higher cadence, allowing us to derive improved estimates for this planet’s radius, semimajor axis, and orbital period, which greatly reduce the uncertainty in the prediction of near future transit times for the James Webb Space Telescope (JWST) observations. We also evaluate the system’s suitability for atmospheric characterization with JWST and find that it is currently the only small (K2–28b to be representative of the kind of mid-M systems that should be detectable in the TESS sample.

Staphylococcus aureus Lpl Lipoproteins Delay G2/M Phase Transition in HeLa Cells.

Science.gov (United States)

Nguyen, Minh-Thu; Deplanche, Martine; Nega, Mulugeta; Le Loir, Yves; Peisl, Loulou; Götz, Friedrich; Berkova, Nadia

2016-01-01

The cell cycle is an ordered set of events, leading to cell growth and division into two daughter cells. The eukaryotic cell cycle consists of interphase (G 1 , S, and G 2 phases), followed by the mitotic phase and G 0 phase. Many bacterial pathogens secrete cyclomodulins that interfere with the host cell cycle. In Staphylococcus aureus four cyclomodulins have been described so far that all represent toxins and are secreted into the culture supernatant. Here we show that the membrane-anchored lipoprotein-like proteins (Lpl), encoded on a genomic island called νSaα, interact with the cell cycle of HeLa cells. By comparing wild type and lpl deletion mutant it turned out that the lpl cluster is causative for the G2/M phase transition delay and also contributes to increased invasion frequency. The lipoprotein Lpl1, a representative of the lpl cluster, also caused G2/M phase transition delay. Interestingly, the lipid modification, which is essential for TLR2 signaling and activation of the immune system, is not necessary for cyclomodulin activity. Unlike the other staphylococcal cyclomodulins Lpl1 shows no cytotoxicity even at high concentrations. As all Lpl proteins are highly conserved there might be a common function that is accentuated by their multiplicity in a tandem gene cluster. The cell surface localized Lpls' suggests a correlation between G2/M phase transition delay and host cell invasion.

Pressure dependence of optical transitions in In0.15Ga0.85N/GaN multiple quantum wells

International Nuclear Information System (INIS)

Shan, W.; Ager, J.W. III; Walukiewicz, W.; Haller, E.E.; McCluskey, M.D.; Johnson, N.M.; Bour, D.P.

1998-01-01

The effects of hydrostatic pressure on optical transitions in In 0.15 Ga 0.85 N/GaN multiple quantum wells (MQW close-quote s) have been studied. The optical transition associated with confined electron and hole states in the MQW close-quote s was found to shift linearly to higher energy with pressure but exhibit a significantly weaker pressure dependence compared to bulklike thick epitaxial-layer samples. Similar pressure coefficients obtained by both photomodulation and photoluminescence measurements rule out the possibility of the transition involving localized states deep in the band gap. We found that the difference in the compressibility of In x Ga 1-x N and GaN induces a tensile strain in the compressively strained In x Ga 1-x N well layers, partially compensating the externally applied hydrostatic pressure. This mechanical effect is primarily responsible for the smaller pressure dependence of the optical transitions in the In x Ga 1-x N/GaN MQW close-quote s. In addition, the pressure-dependent measurements allow us to identify a spectral feature observed at an energy below the GaN band gap. We conclude that this feature is due to transitions from ionized Mg acceptor states to the conduction band in the p-type GaN cladding layer rather than a confined transition in the MQW close-quote s. copyright 1998 The American Physical Society

Mechanical properties and electronic structure of anti-ReO3 structured cubic nitrides, M3N, of d block transition metals M: An ab initio study

International Nuclear Information System (INIS)

Zhou, Xiuquan; Gall, Daniel; Khare, Sanjay V.

2014-01-01

Highlights: • We use DFT to model the anti-ReO 3 structured transition metal nitrides M 3 N. • We predict their lattice constants, electronic structures and mechanical properties. • We correlate the metal d and nitrogen 2p orbitals with stability and hardness. • We established a high-throughput database for materials design. - Abstract: We report a systematic study of the anti-ReO 3 structured transition metal nitrides, M 3 N, using ab initio density functional theory computations in the local density approximation. Here M denotes all the 3d, 4d and 5d transition metals. Our calculations indicate that all M 3 N compounds except V 3 N of group 5 and Zn 3 N and Hg 3 N of group 12 are mechanically stable. For the stable M 3 N compounds, we report a database of predictions for their lattice constants, electronic properties and mechanical properties including bulk modulus, Young’s modulus, shear modulus, ductility, hardness and Debye temperature. It is found that most M 3 N compounds exhibit ductility with Vickers hardness between 0.4 GPa and 11.2 GPa. Our computed lattice constant for Cu 3 N, the only M 3 N compound where experiments exist, agrees well with the experimentally reported values. We report ratios of the melting points of all M 3 N compounds to that of Cu 3 N. The local density of states for all M 3 N compounds are obtained, and electronic band gaps are observed only for M of group 11 (Cu, Ag and Au) while the remaining M 3 N compounds are metallic without band gaps. Valence electron density along with the hybridization of the metal d and nitrogen 2p orbitals play an important role in determining the stability and hardness of different compounds. Our high-throughput databases for the cubic anti-ReO 3 structured transition metal nitrides should motivate future experimental work and shorten the time to their discovery

Critical parameters near the ferromagnetic-paramagnetic phase transition in La0.7A0.3(Mn1-xbx)O3 (A=Sr; B=Ti and Al; x=0.0 and 0.05) compounds

International Nuclear Information System (INIS)

Khiem, N.V.; Phong, P.T.; Bau, L.V.; Nam, D.N.H.; Hong, L.V.; Phuc, N.X.

2009-01-01

The critical parameters provide important information concerning the interaction mechanisms near the paramagnetic-to-ferromagnetic transition. In this paper, we present a thorough study for the critical behavior of La 0.7 A 0.3 (Mn 1-x B x )O 3 (A=Sr; B=Ti and Al; x=0.0 and 0.05) polycrystalline samples near ferromagnetic-paramagnetic phase transition temperature by analyzing isothermal magnetization data. We have analyzed our dc-magnetization data near the transition temperature with the help of the modified Arrot plot, Kouvel-Fisher method. We have determined the critical temperature T C and the critical parameters β, γ and δ. With the values of T C , β and γ, we plot Mx(1-T/T C ) -β vs. Hx(1-T/T C ) -γ . All the data collapse on one of the two curves. This suggests that the data below and above T C obey scaling, following a single equation of state. Critical parameters for x=0 and x Ti =0.05 samples are between those predicted for a 3D-Heisenberg model and mean-field theory and for x Al =0.05 samples the values obtained for the critical parameters are close to those predicted by the mean-field theory.

First identification of the 0{sub 2}{sup +} state in {sup 30}Mg via its E0 transition

Energy Technology Data Exchange (ETDEWEB)

Schwerdtfeger, Wolfgang Norbert Erik

2008-08-28

The known 1789 keV level in {sup 30}Mg turned out to be a candidate for the 0{sub 2}{sup +} state due to its long lifetime of 3.9(4) ns and the absence of a {gamma} transition to the ground state. This triggered our search on the 0{sub 2}{sup +}{yields}0{sub 1}{sup +} E0 transition in {sup 30}Mg following the {beta} decay of {sup 30}Na: {beta} decay electrons were detected in a scintillation detector, while conversion electrons were focused onto a cooled Si(Li) detector using a Mini-Orange and detected with high resolution, which simultaneously suppresses the high background of {beta} decay electrons. Due to the large Q value of the {beta} decay of {sup 30}Na (17.3 MeV) the suppression of the coincident background induced by high-energy {gamma} rays and subsequently Compton-scattered electrons turned out to be the key challenge for the success of this experiment. In order to optimise the background suppression and thus the sensitivity to weak E0 transitions, offline test measurements using an {sup 90}Y and a {sup 152}Eu source were performed together with GEANT4 simulations. Resulting from these test measurements a highly sensitive experimental setup was designed and built, consequently minimising the amount of high-Z material in the target chamber, reducing X-ray production. As a by-product from test measurements the database value of the half-life of the 0{sub 2}{sup +} state in {sup 90}Zr could be corrected by more than 30 % to be t{sub 1/2}=41(1) ns. Finally, in a {beta} decay experiment at the ISOLDE facility at CERN the 0{sub 2}{sup +}{yields}0{sub 1}{sup +} E0 transition in {sup 30}Mg could be identified at the expected transition energy of 1788 keV proving for the first time shape coexistence at the borderline of the 'Island of Inversion'. This identification allows to determine the electric monopole strength as {rho}{sup 2}(E0)=26.2(7.5) x 10{sup -3}, indicating a rather weak mixing between the states in two potential minima in a simplified two

Transverse susceptibility as a probe of the magnetocrystalline anisotropy-driven phase transition in Pr0.5Sr0.5CoO3

Science.gov (United States)

Frey Huls, N. A.; Bingham, N. S.; Phan, M. H.; Srikanth, H.; Stauffer, D. D.; Leighton, C.

2011-01-01

Half-doped Pr1-xSrxCoO3 (x=0.5) displays anomalous magnetism, most notably manifest in the field-cooled magnetization versus temperature curves under different applied cooling fields. Recently, an explanation was advanced that a magnetocrystalline anisotropy transition driven by a structural transition at 120 K is the origin of this behavior. In this paper, we further elucidate the nature of the magnetic anisotropy across the low-temperature phase transition in this material by means of transverse susceptibility (TS) measurements performed using a self-resonant tunnel diode oscillator. TS probes magnetic materials by means of a small radio frequency oriented transverse to a dc field that sweeps from positive to negative saturation. TS scans as a function of field clearly reveal peaks associated with the anisotropy (HK) and switching fields (HS). When peak position is examined as a function of temperature, ˜120 K the signature of a ferromagnetic-to-ferromagnetic phase transition is evident as a sharp feature in HK and a corresponding cusp in HS. A third TS peak (not previously observed in other classes of magnetic oxides such as manganites and spinel ferrites) is found to be correlated with the crossover field (Hcr) in the unconventional magnetization versus temperature [M(T)] behavior. We observe a strong temperature dependence of Hcr at ˜120 K using this technique, which suggests the magnetic-field-influenced magnetocrystalline anisotropy transition. We show the switching between the high-field magnetization state and the low-field magnetization state associated with the magnetocrystalline anisotropy transition is irreversible when the magnetic field is recycled. Finally, we demonstrate that the TS peak magnitude indicates easy axis switching associated with this phase transition, even in these polycrystalline samples. Our results further confirm that TS provides new insights into the magnetic behavior of complex oxides.

Necessary and sufficient conditions for the ergodicity of Markov chains with transition Δm,n(Δ′m,n-matrix

Directory of Open Access Journals (Sweden)

A. Dukhovny

1987-01-01

Full Text Available This paper isolates and studies a class of Markov chains with a special quasi-triangular form of the transition matrix [so-called Δm,n(Δ′m,n-matrix]. Many discrete stochastic processes encountered in applications (queues, inventories and dams have transition matrices which are special cases of a Δm,n(Δ′m,n-matrix. Necessary and sufficient conditions for the ergodicity of a Markov chain with transition Δm,n(Δ′m,n-matrix are determined in the article in two equivalent versions. According to the first version, these conditions are expressed in terms of certain restrictions imposed on the generating functions Ai(x of the elements of the i-th row of the transition matrix, i=0,1,2,…; in the other version they are connected with the characterization of the roots of a certain associated function in the unit circle of the complex plane. Results obtained in the article generalize, complement, and refine similar results existing in the literature.

Isothermal phase transition and the transition temperature limitation in the lead-free (1-x)Bi0.5Na0.5TiO3-xBaTiO3 system

International Nuclear Information System (INIS)

Zhang, Dawei; Yao, Yonggang; Fang, Minxia; Luo, Zhengdong; Zhang, Lixue; Li, Linglong; Cui, Jian; Zhou, Zhijian; Bian, Jihong; Ren, Xiaobing; Yang, Yaodong

2016-01-01

Most ferroelectric transitions occur ultrafast and are time independent. However, here in (1-x) (Bi 0.5 Na 0.5 )TiO 3 -xBaTiO 3 , we have found a ferroelectric phase transition induced solely by increasing waiting time at certain temperatures (isothermal phase transition). Through cooling, a unique metastable state between a relaxor ferroelectric and a ferroelectric is unveiled, which in essence is initially a short-range ordered glassy state and then can evolve into a long-range ordered ferroelectric state through the isothermal process. It is also found that these isothermal ferroelectric transitions only occur within a specific temperature region with different waiting time needed. These features of isothermal phase transition can be understood by Landau theory analysis with the consideration of random defects as a competition between the thermodynamically favored long-range ordered state and the kinetically frustrated short-range ordered glassy state from random defects. This study offers a precise experimental as well as a phenomenological interpretation on the isothermal ferroelectric transition, which may help to further clarify the intricate structure-property relationship in this important lead-free piezoelectric material and other related systems.

Search for b->u Transitions inB- -> D0 K- and B- -> D*0 K-

Energy Technology Data Exchange (ETDEWEB)

Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; /Annecy, LAPP; Grauges, E.; /Barcelona, IFAE; Palano, A.; Pappagallo, M.; Pompili, A.; /Bari U. /INFN, Bari; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; /Beijing, Inst. High Energy Phys.; Eigen, G.; Ofte, I.; Stugu, B.

2005-05-27

The authors search for B{sup -} {yields} {tilde D}{sup 0}K{sup -} and B{sup -} {yields} {tilde D}*{sup 0}K{sup -}, with {tilde D}*{sup 0} {yields} {tilde D}{sup 0}{pi}{sup 0} or {tilde D}*{sup 0} {yields} {tilde D}{sup 0}{gamma}, and {tilde D}{sup 0} {yields} K{sup +}{pi}{sup -} (and charge conjugates). These final states can be reached through the b {yields} c transition B{sup -} {yields} D{sup (*)0}K{sup -} followed by the doubly CKM-suppressed D{sup 0} {yields} K{sup +}{pi}{sup -}, or the b {yields} u transition B{sup -} {yields} {bar D}{sup (*)0}K{sup -} followed by the CKM-favored {bar D}{sup 0} {yields} K{sup +}{pi}{sup -}. The interference of these two amplitudes is sensitive to the angle {gamma} of the unitarity triangle. The results are based on 232 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at SLAC. They find no significant evidence for these decays. They set a limit r{sub B} {triple_bond} |A(B{sup -} {yields} {bar D}{sup 0}K{sup -})/A(B{sup -} {yields} D{sup 0}K{sup -})| < 0.23 at 90% C.L. using the most conservative assumptions on the values of the CKM angle {gamma} and the strong phases in the B and D decay amplitudes. In the case of the D* they set a 90% C.L. limit r*{sub B}{sup 2} {triple_bond} |A(B{sup -} {yields} {bar D}*{sup 0}K{sup -})/A(B{sup -} {yields} D*{sup 0} K{sup -})|{sup 2} < (0.16){sup 2} which is independent of assumptions on {gamma} and strong phases.

Neutron Diffraction Study On Gamma To Alpha Phase Transition In Ce0.9th0.1 Alloy

Energy Technology Data Exchange (ETDEWEB)

Lashley, Jason C1 [Los Alamos National Laboratory; Heffner, Robert H [Los Alamos National Laboratory; Llobet, A [Los Alamos National Laboratory; Darling, T W [U OF NEVADA; Jeong, I K [PUSAN NATL UNIV

2008-01-01

Comprehensive neutron diffraction measurements were performed to study the isostructural {gamma} {leftrightarrow} {alpha} phase transition in Ce{sub 0.9}Th{sub 0.1} alloy. Using Rietveld refinements, we obtained lattice and thermal parameters as a function of temperature. From the temperature slope of the thermal parameters, we determined Debye temperatures {Theta}{sup {gamma}}{sub D} = 133(1) K and {Theta}{sup {alpha}}{sub D} = 140(1) K for the {gamma} phase and the {alpha} phase, respectively. This result implies that the vibrational entropy change is not significant at the {gamma} {leftrightarrow} {alpha} transition, contrary to that from elemental Cerium [Phys. Rev. Lett. 92, 105702, 2004].

Evolution of 0.7--3.0 M/sub sun/ stars having -1.0< or =[Fe/H]< or =0.0

International Nuclear Information System (INIS)

VandenBerg, D.A.

1985-01-01

Five grids of stellar models have been calculated for masses ranging from 0.7 to 3.0 M/sub sun/ assuming, in turn, a metal abundance [Fe/H] = -1.0, -0.76, -0.46, -0.23, and 0.0. All of the calculations are based on a value of Y = 0.25 for the helium content and α = 1.6 for the ratio of the mixing length to the pressure scale height. The latest improvements in opacity data and nuclear reaction rates have been incorporated into the computations. Moreover, model atmospheres have been used to provide the boundary conditions for the stellar interior calculations as well as to transpose the isochrones, computed for ages from 0.3 x 10 9 to 15 x 10 9 yr, from the theoretical to the (M/sub v/, B-V)-plane. Cousins V-I and V-R colors are also predicted for each of the model sequences, which are extensively tabulated

Electrical properties and phase transition of Ba(Zr{sub 0.05}Ti{sub 0.95}){sub 1−x}(Fe{sub 0.5}Ta{sub 0.5}){sub x}O{sub 3} ceramics

Energy Technology Data Exchange (ETDEWEB)

Kruea-In, C. [Faculty of Science and Technology, Chiang Mai Rajabhat University (Thailand); Rujijanagul, G., E-mail: rujijanagul@yahoo.com [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University (Thailand)

2015-09-15

Highlights: • Properties of of Ba(Zr{sub 0.05}Ti{sub 0.95}){sub 1−x}(Fe{sub 0.5}Ta{sub 0.5}){sub x}O{sub 3} ceramics were investigated. • Small amount of dopant produced a large change in dielectric and phase transition. • A phase diagram of Ba(Zr{sub 0.05}Ti{sub 0.95}){sub 1−x}(Fe{sub 0.5}Ta{sub 0.5}){sub x}O{sub 3} ceramics was proposed. • Dielectric tunability increased with increasing x concentration. - Abstract: In this work, properties of Ba(Zr{sub 0.05}Ti{sub 0.95}){sub 1−x}(Fe{sub 0.5}Ta{sub 0.5}){sub x}O{sub 3} ceramics with 0.00≤ x ≤0.07 were investigated. The ceramics were fabricated by a solid state reaction technique. X-ray diffraction analysis indicated that all samples exhibited single phase perovskite. Examination of the dielectric spectra revealed that the Fe and Ta additives promoted a diffuse phase transition, and the two phase transition temperatures, as observed in the dielectric curve of pure Ba(Zr{sub 0.05}Ti{sub 0.95})O{sub 3}, merged into a single phase transition temperature for higher x concentrations. The transformation was confirmed by ferroelectric measurements. In addition, the doped ceramics exhibited high relative dielectric tunability, especially for higher x concentration samples.

Abnormal magnetization and field-induced transition in (La0.73Bi0.27)0.67Ca0.33MnO3

International Nuclear Information System (INIS)

Li Haina; Wu Yuying; Yu Hongwei; Chen Ziyu; Huang Yan; Wang Shaoliang; Li Liang; Xia Zhengcai

2010-01-01

The magnetic field dependence of magnetization of Bi doped manganites (La 1-x Bi x ) 0.67 Ca 0.33 MnO 3 (x=0.27) was investigated at different temperatures with a pulsed high magnetic field. A metamagnetic transition was observed in the magnetization measurement, which revealed the coexistence of charge ordering (CO) and ferromagnetic (FM) phases. With decreasing magnetic field, the field-induced FM phases remained stable even when the magnetic field decreased to zero. This result suggests that ferromagnetic interactions are enhanced due to the effect of the pulsed high magnetic field, which makes the doped manganites a good system for magnetoresistance materials.

Effect of Sintering Temperature on Microstructure, Chemical Stability, and Electrical Properties of Transition Metal or Yb-Doped BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.1}M{sub 0.1}O{sub 3−δ} (M = Fe, Ni, Co, and Yb)

Energy Technology Data Exchange (ETDEWEB)

Mirfakhraei, Behzad; Ramezanipour, Farshid; Paulson, Scott; Birss, Viola; Thangadurai, Venkataraman, E-mail: vthangad@ucalgary.ca [Department of Chemistry, University of Calgary, Calgary, AB (Canada)

2014-03-13

Perovskite-type BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.1}M{sub 0.1}O{sub 3−δ} (M = Fe, Ni, Co, and Yb) (BZCY-M) oxides were synthesized using the conventional solid-state reaction method at 1350–1550°C in air in order to investigate the effect of dopants on sintering, crystal structure, chemical stability under CO{sub 2} and H{sub 2}S, and electrical transport properties. The formation of the single-phase perovskite-type structure with an orthorhombic space group Imam was confirmed by Rietveld refinement using powder X-ray diffraction for the Fe, Co, Ni, and Yb-doped samples. The BZCY-Co and BZCY-Ni oxides show a total electrical conductivity of 0.01 and 8 × 10{sup −3} S cm{sup −1} at 600°C in wet H{sub 2} with an activation energy of 0.36 and 0.41 eV, respectively. Scanning electron microscope and energy-dispersive X-ray analysis revealed Ba and Co-rich secondary phase at the grain-boundaries, which may explain the enhancement in the total conductivity of the BZCY-Co. However, ex-solution of Ni at higher sintering temperatures, especially at 1550°C, decreases the total conductivity of the BZCY-Ni material. The Co and Ni dopants act as a sintering aid and form dense pellets at a lower sintering temperature of 1250°C. The Fe, Co, and Ni-doped BZCY-M samples synthesized at 1350°C show stability in 30 ppm H{sub 2}S/H{sub 2} at 800°C, and increasing the firing temperature to 1550°C, enhanced the chemical stability in CO{sub 2}/N{sub 2} (1:2) at 25–900°C. The BZCY-Co and BZCY-Ni compounds with high conductivity in wet H{sub 2} could be considered as possible anodes for intermediate temperature solid oxide fuel cells.

Efficacy and safety of fixed-combination travoprost 0.004%/timolol 0.5% in patients transitioning from bimatoprost 0.03%/timolol 0.5% combination therapy

Directory of Open Access Journals (Sweden)

Schnober D

2015-05-01

Full Text Available Dietmar Schnober,1 Douglas A Hubatsch,2 Maria-Luise Scherzer3 1Private Ophthalmology Practice, Werdohl, Germany; 2Alcon Laboratories, Inc., Fort Worth, TX, USA; 3Private Ophthalmology Practice, Regenstauf, Germany Purpose: To determine the efficacy and safety of fixed-combination travoprost 0.004%/timolol 0.5% preserved with polyquaternium-1 in patients with insufficient response to bimatoprost 0.03%/timolol 0.5% preserved with benzalkonium chloride.Patients and methods: In this open-label nonrandomized study conducted at 13 European sites, patients with primary open-angle glaucoma or ocular hypertension with insufficient intraocular pressure (IOP reduction during bimatoprost/timolol therapy were transitioned to travoprost/timolol (DuoTrav® administered every evening for 12 weeks. Change in IOP from baseline to week 12 was assessed in patients who transitioned from fixed-combination bimatoprost/timolol (n=57, primary endpoint. Secondary assessments included change in IOP at week 4, percentage of patients with IOP ≤18 mmHg at weeks 4 and 12, change in Ocular Surface Disease Index and ocular hyperemia scores at week 12, and patient preference. Adverse events were also reported.Results: IOP change (mean ± SD from baseline to week 12 was –3.8±1.9 mmHg (P<0.001; results were similar at week 4. Most patients had IOP ≤18 mmHg at weeks 4 and 12 (78.6% and 85.5%, respectively. Mean Ocular Surface Disease Index score was significantly reduced (P<0.001; no significant change in ocular hyperemia score was observed (P=0.197. Treatment-related adverse events included dysgeusia, nausea, paresthesia, myalgia, headache, and eye irritation (n=1 each. Most patients (74.5% preferred travoprost/timolol over bimatoprost/timolol.Conclusion: Transition to travoprost/timolol significantly reduced IOP and was well tolerated in patients who had elevated IOP despite bimatoprost/timolol therapy. Polyquaternium-1–preserved travoprost/timolol was preferred over

HAT-P-49b: a 1.7 M {sub J} planet transiting a bright 1.5 M {sub ☉} F-star

Energy Technology Data Exchange (ETDEWEB)

Bieryla, A.; Latham, D. W.; Buchhave, L. A.; Béky, B.; Falco, E.; Torres, G.; Noyes, R. W.; Berlind, P.; Calkins, M. C.; Esquerdo, G. A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Hartman, J. D.; Bakos, G. Á.; Bhatti, W.; Csubry, Z.; Penev, K.; De Val-Borro, M. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Kovács, G. [Konkoly Observatory, Budapest 1121 (Hungary); Boisse, I. [Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Lázár, J.; Papp, I., E-mail: abieryla@cfa.harvard.edu, E-mail: gbakos@astro.princeton.edu [Hungarian Astronomical Association (HAA), Budapest 1461 (Hungary); and others

2014-04-01

We report the discovery of the transiting extrasolar planet HAT-P-49b. The planet transits the bright (V = 10.3) slightly evolved F-star HD 340099 with a mass of 1.54 M {sub ☉} and a radius of 1.83 R {sub ☉}. HAT-P-49b is orbiting one of the 25 brightest stars to host a transiting planet which makes this a favorable candidate for detailed follow-up. This system is an especially strong target for Rossiter-McLaughlin follow-up due to the host star's fast rotation, 16 km s{sup –1}. The planetary companion has a period of 2.6915 days, mass of 1.73 M {sub J}, and radius of 1.41 R {sub J}. The planetary characteristics are consistent with that of a classical hot Jupiter but we note that this is the fourth most massive star to host a transiting planet with both M{sub p} and R{sub p} well determined.

On the Meaning of Element in the Science of Italic Tradition, the Question of Physical Objectivity (and/or Physical Meaning) and Quantum Mechanics

Science.gov (United States)

Boscarino, Giuseppe

2006-06-01

It is questioned: Is quantum mechanics a new science or a new (or rather old) philosophy of physical science? It is shown that Einstein's attempt in his article of 1935 to bring the concept of "element" from the classical (we call it Italic) philosophical-epistemological tradition, which goes under the names of Pythagoras Parmenides, Democritus, and Newton, into quantum mechanical theory is unclear, inadequate and contradictory.

Transport properties of S0.8Se16M0.2 (M = Al, Ag or Cu) system

International Nuclear Information System (INIS)

Wahab, L.A.

2003-01-01

The results are presented of a study of the electrical and optical properties of vacuum evaporated amorphous thin films in the S 0.8 Se 16 M 0.2 (M=Al, Ag or Cu) system. The activation energy and the pre-exponential factor which appear in the dc conductivity are found to be higher in case of Cu than in case of Ag and Al. The reflectance and transmission are used to measure the optical gap. The glass S 0.8 Se 16 Cu 0.2 behaves as a quasi intrinsic semiconductor (the electrical activation energy is about half of the optical gap). The electrical activation energy is about one-third of the optical gap for the chalcogenide glasses S 0.8 Se 16 Al 0.2 and S 0.8 Se 16 Ag 0.2 . The variation in the refractive index and the imaginary part of the dielectric constant with photon energy have also been reported. The influence of composition on the investigated parameters is reported

State resolved rotational excitation in HD+D2 collisions. II. Angular dependence of 0→2 transitions

International Nuclear Information System (INIS)

Buck, U.; Huisken, F.; Maneke, G.; Schaefer, J.

1983-01-01

Time-of-flight spectra for the scattering of HD molecules from D 2 molecules have been measured at a collision energy of E = 70.3 meV over a range of center-of-mass scattering angles from 45 0 to 158 0 . The spectra reveal clearly resolved transitions at the energy loss ΔE = 33 meV which corresponds to 0→2 transitions of HD and the double transition 0→1 of HD and 0→2 of D 2 . The differential cross sections derived from these spectra increase with increasing scattering angle from 1.7% to 34.7% of the elastic cross section. The pure 0→2 transition of D 2 which only needs 22 meV to be induced could not be detected within our experimental sensitivity of 0.02 A 2 /sr. Closed coupled calculations based on the ab initio potential surface of Meyer and Schaefer show that this result can be explained by the different coupling terms which are responsible for these transitions. In contrast to the 0→1 transition the 0→2 transition of HD proved to be sensitive to the anisotropic part of the interaction potential for the homonuclear system. The comparison of experimental and calculated cross sections for the ab initio potential of Meyer and Schaefer reveals discrepancies for the 0→1 transition of HD, but shows agreement for the 0→2 transition of HD at intermediate angles

Reexamination of M2,3 atomic level widths and L1M2,3 transition energies of elements 69≤Z≤95

Science.gov (United States)

Fennane, K.; Berset, M.; Dousse, J.-Cl.; Hoszowska, J.; Raboud, P.-A.; Campbell, J. L.

2013-11-01

We report on high-resolution measurements of the photoinduced L1M2 and L1M3 x-ray emission lines of 69Tm, 70Yb, 71Lu, 73Ta, 74W, 75Re, 77Ir, 81Tl, 83Bi, and 95Am. From the linewidths of the measured transitions an accurate set of M2 and M3 level widths is determined assuming for the L1 level widths the values reported by Raboud [P.-A. Raboud et al., Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.65.022512 65, 022512 (2002)]. Furthermore, the present experimental M2,3 data set is extended to 80Hg, 90Th, and 92U, using former L1M2,3 high-resolution x-ray emission spectroscopy measurements performed by our group. A detailed comparison of the M2 and M3 level widths determined in the present work with those recommended by Campbell and Papp [J. L. Campbell and T. Papp, At. Data Nucl. Data TablesADNDAT0092-640X10.1006/adnd.2000.0848 77, 1 (2001)] and other available experimental data as well as theoretical predictions is done. The observed abrupt changes of the M2,3 level widths versus atomic number Z can be explained satisfactorily by the cutoffs and onsets of the M2M4N1, respectively M3M4N3,4,5 and M3M5N2,3 Coster-Kronig transitions deduced from the semiempirical (Z+1) approximation. As a spin-off result of this study, precise L1M2 and L1M3 transition energies are obtained for the investigated elements. A very good agreement with transition energies calculated within the many-body perturbation theory is found.

Use of M and L transitions of heavy elements for the determination of a Si(Li) detector's efficiency

International Nuclear Information System (INIS)

Morales, J.R.; Romo, C.; Dinator, M.I.; Llona, F.; Tabacniks, M.

1987-01-01

The verification of the Si(Li) cryogenic detector's efficiency may be fastly carried out using the M radiations of the heavy elements, such as Pb and Au. Thin targets have been bombarded with protons of 2.0 and 6.6 MeV, thus resulting the transitions M and L. The number of emitted photons are possible to be inferred using tabulated cross sections from different authors. The comparison with the number of photons registered allows to determine the efficiency. (S.M.) [es

A comparative study of magnetic field induced meta-magnetic transition in nanocrystalline and bulk Pr{sub 0.65}(Ca{sub 0.7}Sr{sub 0.3}){sub 0.35}MnO{sub 3} compound

Energy Technology Data Exchange (ETDEWEB)

Saha, Suvayan [CMP Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700 064 (India); Center for Research in Nanoscience and Nanotechnology, University of Calcutta, JD-2, Salt Lake City, Kolkata 700098, West Bengal (India); Department of Physics, University of Calcutta, 92 A.P.C. Road, Kolkata 700009 (India); Das, Kalipada, E-mail: kalipadadasphysics@gmail.com [Department of Materials Science, Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mullick Road, Jadavpur, Kolkata 700032 (India); Bandyopadhyay, Sudipta [Center for Research in Nanoscience and Nanotechnology, University of Calcutta, JD-2, Salt Lake City, Kolkata 700098, West Bengal (India); Department of Physics, University of Calcutta, 92 A.P.C. Road, Kolkata 700009 (India); Das, I. [CMP Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700 064 (India)

2017-06-15

Highlights: • Field induced sharp meta-magnetic transition appears even in nanocrystalline sample. • Magnetic field for the meta-magnetic transition enhances depending upon the cooling field. • This unusual behavior is addressed by the effect of the interfacial strains. - Abstract: In our present study we highlight the observations of external magnetic field induced sharp meta-magnetic transition in polycrystalline bulk as well as nanocrystalline form of Pr{sub 0.65}(Ca{sub 0.7}Sr{sub 0.7}){sub 0.35}MnO{sub 3} compound. Interestingly, such behavior persists in the nanoparticles regardless of the disorder broadened transition. However, higher magnetic field is required for nanoparticles having average particle size ∼40 nm for such meta-magnetic transition, which differs from the general trends of the pure charge ordered nano materials. The interfacial strain between the different magnetic domains plays the important role in magnetic isothermal properties of nanoparticles, when the samples are cooled down in different cooling field. Additionally, both the bulk and nanoparticle compounds exhibit spontaneous phase separation and significantly large magnetoresistance at the low temperature region due to the melting of charge ordered fraction.

Electrical dipole polarizability and spin M1 strength from {sup 48}Ca(p,p') data under 0; Elektrische Dipol-Polarisierbarkeit und Spin-M1-Staerke aus {sup 48}Ca(p,p')-Daten unter 0

Energy Technology Data Exchange (ETDEWEB)

Birkhan, Jonny Hubertus

2016-07-01

In this thesis, proton scattering data on the nucleus {sup 48}Ca at very forward angles had been analysed. The data stem from a measurement campaign which was launched at the Research Centre of Nuclear Physics at Osaka, Japan, in the past. One of the two objectives of this analysis was to extract a value for the static electric dipole polarisability from the isovector giant dipole resonance (IVGDR). The second objective was to extract the total electromagnetic M1 strength B(M1) of the spin-flip transition which excites the prominent 1{sup +} state at an excitation energy of E{sub x}=10.22 MeV. The polarisability was calculated from the distribution of photo-absorption cross sections within an energy range from E{sub x}=11 MeV to E{sub x}=26 MeV. The photo-absorption cross sections had been deduced from the distribution of E1 cross sections by the method of virtual photons. For this purpose the experimental cross sections had been deconvoluted by a multipole deconvolution into an E1 part and a background part. Then, the best estimate of the polarisability is given by α{sub D}=(1.36±0.14) fm{sup 3}. If a E3 model was included into the multipole decomposition of the (p,p') data the result increased up to α{sub D}=(1.50±0.09) fm{sup 3}. The deviation between these two results is mainly due to the fact that the multipole decomposition is very sensitive on the background function. Assuming that the the IVGDR of the nuclei {sup 48}Ca and {sup 40}Ca have approximately the same structure, estimates for the polarisability of the nucleus {sup 48}Ca could be drawn from {sup 40}Ca(γ,abs) data. Additionally, data from a {sup 48}Ca(e,e'n) measurement were used to estimate the polarisability of the nucleus {sup 48}Ca. Its polarisability seems to fall within the range of α{sub D}=(1.50±0.09) fm{sup 3} and α{sub D}=(1.69±0.03) fm{sup 3}. Beside this, it could be shown by the {sup 40}Ca data that a significant contribution to the polarisability has to be expected

Total conversion coefficient of the 263 keV (21/sup 2//2->13/sup +//2) transition in sup(93m)Mo

Energy Technology Data Exchange (ETDEWEB)

Suryanaryana, C.; Venkateswara Rao, M.; Narayana, D.G.S.; Bhuloka Reddy, S.; Satyanarayana, G.; Sastry, D.L.; Chintalapudi, S.N.

1985-01-01

The total conversion coefficient of the 263 keV gamma transition in the decay scheme of sup(93m)Mo is measured by intensity balance method using a HP Ge spectrometer system. The experimental value of ..cap alpha..sub(T)(263 keV) is found to be 0.696 +- 0.05 which is in agreement with the theoretical values 0.72 and 0.7. The transition probability T(E4) is calculated using the present value of ..cap alpha..sub(T) and compared with the single-particle estimate. A good agreement is noted between the theory and the experiment for the value of T(E4).

Rates of E1, E2, M1, and M2 transitions in Ni II

Science.gov (United States)

Cassidy, C. M.; Hibbert, A.; Ramsbottom, C. A.

2016-03-01

Aims: We present rates for all E1, E2, M1, and M2 transitions among the 295 fine-structure levels of the configurations 3d9, 3d84s, 3d74s2, 3d84p, and 3d74s4p, determined through an extensive configuration interaction calculation. Methods: The CIV3 code developed by Hibbert and coworkers is used to determine for these levels configuration interaction wave functions with relativistic effects introduced through the Breit-Pauli approximation. Results: Two different sets of calculations have been undertaken with different 3d and 4d functions to ascertain the effect of such variation. The main body of the text includes a representative selection of data, chosen so that key points can be discussed. Some analysis to assess the accuracy of the present data has been undertaken, including comparison with earlier calculations and the more limited range of experimental determinations. The full set of transition data is given in the supplementary material as it is very extensive. Conclusions: We believe that the present transition data are the best currently available. Full Table 4 and Tables 5-8 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/587/A107

Half-lives of isomeric levels of sup 1 sup 0 sup 7 sup m Ag, sup 1 sup 0 sup 9 sup m Ag and sup 1 sup 0 sup 3 sup m Rh photoactivated by sup 6 sup 0 Co gamma-ray irradiation

CERN Document Server

Yoshida, E; Kojima, Y; Shizuma, K

2000-01-01

Photoactivation by gamma-rays from sup 6 sup 0 Co of 10 kCi has been performed for isomers of sup 1 sup 0 sup 7 sup m Ag, sup 1 sup 0 sup 9 sup m Ag and sup 1 sup 0 sup 3 sup m Rh and half-lives of these isomers were determined. Gamma-rays emitted from sup 1 sup 0 sup 7 sup m Ag and sup 1 sup 0 sup 9 sup m Ag were measured with a low-background Ge detector and internal conversion electrons from sup 1 sup 0 sup 3 sup m Rh were measured with a 2 pi gas flow counter. The half-lives obtained are: sup 1 sup 0 sup 7 sup m Ag: 44.5+-0.8 s, sup 1 sup 0 sup 9 sup m Ag: 38.0+-1.2 s and sup 1 sup 0 sup 3 sup m Rh: 54.8+-3.8 min. The results are in agreement with previous values obtained by different excitation methods.

Pressure Effects on the Magnetic Phase Transition of Mn3SnC1−xNx (x = 0, 0.5)

International Nuclear Information System (INIS)

Hu Jing-Yu; Zhao Qing; Wen Yong-Chun; Wang Cong; Yao Yuan; Jin Chang-Qing; Yu Ri-Cheng

2012-01-01

The electronic transport properties of Mn 3 SnC and Mn 3 SnC 0.5 N 0.5 were measured under pressures up to 1.8 GPa. At ambient pressure, an abrupt increase of resistance occurs around the temperature of magnetic phase transition in both samples. The transition temperature Tc from paramagnetic to ferrimagnetic state decreases linearly at rates of 12.6 and 6.3K/GPa with pressure for Mn 3 SnC and Mn 3 SnC 0.5 N 0.5 , respectively. This phenomenon could be understood by the Labbe-Jardin tight binding approximation model. (condensed matter: structure, mechanical and thermal properties)

Large-field behavior of the LoSurdo-Stark resonances in atomic hydrogen

Energy Technology Data Exchange (ETDEWEB)

Alvarez, G. (Departamento de Fisica Teorica, Facultad de Ciencias Fisicas, Universidad Complutense, 28040 Madrid (Spain)); Silverstone, H.J. (Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218 (United States))

1994-12-01

The Schroedinger equation for atomic hydrogen in a large electric field [ital F] is solved by separation in parabolic coordinates. As [ital F][r arrow][infinity], the scaled field [ital f] that enters the separated equations tends to 0. Thus the large-[ital F] asymptotics depend on the small-[ital f] behavior of the separated equations, each of which in turn is equivalent to a quarticly perturbed two-dimensional anharmonic oscillator. The Bender-Wu branch cuts of the oscillator play a major role in the hydrogen asymptotics. A simple iterative algorithm permits the calculation of the branch points at which two eigenvalues coincide. We have found numerically that, as [ital F][r arrow][infinity], the separation constant [beta][sub 1] returns to the smaller of the unperturbed values [beta][sub 1][sup (0)] or [beta][sub 2][sup (0)]. At the same time, [beta][sub 2] tends to the negative of the smaller value. As the real electric field [ital F] increases from 0 to [infinity], in each case that [beta][sub 1][sup (0)] and [beta][sub 2][sup (0)] are not equal, the trajectory of either [ital f] or [ital e][sup [minus][ital i][pi

Spectral-converting study of La{sub 1−m−n}Er{sub m}Yb{sub n}OCl (m=0.001–0.2, n=0–0.1) phosphors

Energy Technology Data Exchange (ETDEWEB)

Park, Sangmoon, E-mail: spark@silla.ac.kr [Center for Green Fusion Technology and Department of Engineering in Energy and Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Cho, So-Hye [Center for Materials Architecturing, Institute of Multidisciplinary Convergence of Materials, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)

2014-09-15

Optical materials composed of La{sub 1−m−n}Er{sub m}Yb{sub n}OCl (m=0.001–0.2, n=0–0.1) solid solution were prepared via a solid-state reaction using excess NH{sub 4}Cl flux at 950 °C for 30 min. X-ray diffraction patterns of La{sub 1−m}Er{sub m}OCl were compared upon altering the molar ratios of the flux to the La{sup 3+} (Er{sup 3+}, Yb{sup 3+}) ions. By means of photoluminescence spectra, the dependence of the luminescence intensity as a function of the Er{sup 3+} content and the color CIE coordinates of the Er{sup 3+}-doped layered LaOCl compounds were also investigated under excitation by near-ultraviolet (NUV) and visible light. The spectral conversion properties of Er{sup 3+} and Er{sup 3+}–Yb{sup 3+} ions doped into LaOCl phosphors were elucidated under diode-laser irradiation of 980 nm in wavelength. The desired up-conversion of the emitting light, passing throughout the green, orange, and red regions of the spectrum, was achieved by appropriate Er{sup 3+} and/or Yb{sup 3+} concentrations in the LaOCl host structure under 980-nm-excitation light, while its mechanism in the phosphors was described by an energy-level schematic. Up-conversion emission spectra and the dependence of the emission intensity on pump power in the La{sub 0.89}Er{sub 0.1}Yb{sub 0.01}OCl phosphor were investigated under diode-laser irradiation of both wavelengths, 980 and 1550 nm. - Highlights: • Flux-assisted La{sub 1−m−n}Er{sub m}Yb{sub n}OCl (m=0.001–0.2, n=0–0.1) phosphors were prepared. • Distinctive photoluminescence properties of Er{sup 3+}-doped LaOCl were investigated. • Spectral converting properties of Er{sup 3+} and Yb{sup 3+} in LaOCl phosphors were elucidated. • Up-conversion mechanisms are proposed on the basis of an energy-level diagram. • Dependence of the emission intensity on pump power in the phosphor was investigated.

Socio-economic, agronomic and molecular analysis of yam and cowpea diversity in the Guinea-Sudan transition zone of Benin

NARCIS (Netherlands)

Zannou, A.

2006-01-01

Keywords: Cowpea (Vigna unguiculata(L.) Walp.),

Occult abnormal pregnancies after first post-embryo transfer serum beta-human chorionic gonadotropin levels of 1.0-5.0 mIU/mL.

Science.gov (United States)

Maslow, Bat-Sheva L; Bartolucci, Alison; Sueldo, Carolina; Engmann, Lawrence; Benadiva, Claudio; Nulsen, John C

2016-04-01

To assess the occult pregnancy rate after "negative" first post-embryo transfer (ET) serum β-hCG results. Two-part retrospective cohort study and nested case series. University-based fertility center. A total of 1,571 negative first post-ET serum β-hCG results were included in the study; 1,326 results (primary cohort, June 2009-December 2013) were initially reported as <5 mIU/mL and 245 results (secondary cohort, January 2014-March 2015) were reported as discrete values from 1.0 to 5.0 mIU/mL. None. Rates of occult pregnancy, ectopic pregnancy, and complications after negative first post-ET serum β-hCG results. A total of 88.8% (1,178/1,326) of the negative first post-ET results reported as <5 were actually <1.0 mIU/mL. Occult pregnancy was incidentally identified in 1.2% (12/1,041) of subjects with follow-up. Six had ectopic pregnancies, and seven experienced serious complications; 11 (91.7%) of the 12 occult pregnancies had a first post-ET serum β-hCG level of 1.0-5.0 mIU/mL and 1 (8.3%) <1.0 mIU/mL. All pregnancies with serious complications had initial β-hCG levels of 1.0-5.0 mIU/mL. Of the 245 results reported as discreet values, occult pregnancies were diagnosed in 5.5% (9/163) of subjects with follow-up. One had an ectopic pregnancy, which was treated with methotrexate. There were no serious complications in the secondary cohort. The majority of negative first post-ET serum β-hCG levels are <1.0 mIU/mL. Results from 1.0 to 5.0 mIU/mL may fail to exclude abnormal pregnancy and are associated with poor outcomes compared with β-hCG levels <1.0 mIU/mL. Serial serum β-hCG may be warranted in this population. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Technical Note: Effect of explicit M and N-shell atomic transitions on a low-energy x-ray source

Energy Technology Data Exchange (ETDEWEB)

Watson, Peter G. F., E-mail: peter.watson@mail.mcgill.ca; Seuntjens, Jan [Medical Physics Unit, McGill University, Montreal, Quebec H4A 3J1 (Canada)

2016-04-15

Purpose: In EGSnrc, atomic transitions to and from the M and N-shells are treated in an average way by default. This approach is justified in which the energy difference between explicit and average M and N-shell binding energies is less than 1 keV, and for most applications can be considered negligible. However, for simulations of low energy x-ray sources on thin, high-Z targets, characteristic x-rays can make up a significant portion of the source spectra. As of release V4-2.4.0, EGSnrc has included an option to enable a more complete algorithm of all atomic transitions available in the EADL compilation. In this paper, the effect of M and N-shell averaging on the calculation of half-value layer (HVL) and relative depth dose (RDD) curve of a 50 kVp intraoperative x-ray tube with a thin gold target was investigated. Methods: A 50 kVp miniature x-ray source with a gold target (The INTRABEAM System, Carl Zeiss, Germany) was modeled with the EGSnrc user code cavity, both with and without M and N-shell averaging. From photon fluence spectra simulations, the source HVLs were determined analytically. The same source model was then used with egs-chamber to calculate RDD curves in water. Results: A 4% increase of HVL was reported when accounting for explicit M and N-shell transitions, and up to a 9% decrease in local relative dose for normalization at 3 mm depth in water. Conclusions: The EGSnrc default of using averaged M and N-shell binding energies has an observable effect on the HVL and RDD of a low energy x-ray source with high-Z target. For accurate modeling of this class of devices, explicit atomic transitions should be included.

Effects of oxygen content and heating rate on phase transition behavior in Bi2(V0.95Ti0.05)O5.475-x

International Nuclear Information System (INIS)

Taninouchi, Yu-ki; Uda, Tetsuya; Ichitsubo, Tetsu; Awakura, Yasuhiro; Matsubara, Eiichiro

2011-01-01

Highlights: → Phase transition behavior of oxide-ion conductor Bi 2 (V 0.95 Ti 0.05 )O 5.475-x , which has various thermal histories and physical forms. → At the same heating rate of 10 K min -1 , Bi 2 (V 0.95 Ti 0.05 )O 5.475-x with less oxygen content exhibits transition from α f to β f at a higher temperature and the transition from β f to γ f at a lower temperature. → α f directly transformed to β f at fast heating rates. At a slower heating rate of 2 K min -1 , β f precipitated from α f due to the sufficient diffusion of Ti and oxygen vacancies. - Abstract: The phase transition behavior of oxide-ion conductor Bi 2 (V 0.95 Ti 0.05 )O 5.475-x , which has various thermal histories and sample forms, has been studied by means of differential scanning calorimetry. Thermogravimetric analysis revealed that the oxygen content per compositional formula varied with the applied thermal treatment, although no significant structural difference was observed by X-ray diffraction (XRD) analysis. The phase transition behavior from α f to β f and from β f to γ f , observed at a heating rate of 10 K min -1 , are markedly affected by the sample preparation. For example, the endothermic peak of the transition from α f to β f appeared at around 400 deg. C for quenched powder and at around 320 deg. C for powder cooled at 0.5 K min -1 . The trend of the transition temperatures can be qualitatively explained in terms of oxygen content, i.e., Bi 2 (V 0.95 Ti 0.05 )O 5.475-x with less oxygen content exhibits the transition from α f to β f at a higher temperature and the transition from β f to γ f at a lower temperature. We confirmed the two types of transition behavior from α f to β f depending on heating rate of DSC and high-temperature X-ray diffraction (HT-XRD) analysis. At rapid heating rates of 10 and 40 K min -1 , α f transformed to β f directly. Meanwhile, at a slow heating rate of 2 K min -1 , the β f precipitated from α f because slow heating

The Phase Transitions between H 0.27V 0.27W 0.73O 3· {1}/{3} H 2O and V 0.27W 0.73O 2.865: An X-Ray, Thermal Analysis, and HREM Study

Science.gov (United States)

Dupont, L.; Sundberg, M.

1998-03-01

A mixed vanadium-tungsten oxide hydrate (H 0.27V 0.27W 0.73O 3· {1}/{3}H 2O) has been synthesized by a soft chemistry method, and the phase transitions from the hydrate (precursor) to the final product V 0.27W 0.73O 2.865have been studied by thermal analysis, X-ray powder diffraction, and high-resolution electron microscopy (HREM) techniques. Supermetastable, metastable, and stable oxides have been observed. H 0.27V 0.27W 0.73O 3· {1}/{3}H 2O possesses a structure related to WO 3· {1}/{3}H 2O. Dehydration of the precursor leads to a supermetastable phase, H 0.27V 0.27W 0.73O 3, with a structure similar to that of the hydrate. At 350°C this phase transforms to the metastable H 0.27V 0.27W 0.73O 3, with a structure isotypic with WO 3(hex). The phase transition between the hydrate and H 0.27V 0.27W 0.73O 3is both pseudomorphous and topotactic. Removal of hydrogen and oxygen from the metastable oxide induces a second phase transition at 500°C to a more stable phase, V 0.27W 0.73O 2.865, with an oxygen-deficient WO 3-type structure. The monoclinic symmetry of the latter oxide increases at higher temperature, first to orthorhombic and then to tetragonal. This transition is not pseudomorphous but of a topotactic nature. The obtained results suggest that the hydrogen content stabilizes the WO 3(hex)-related structure of the metastable phase. A hypothetical model based on HREM observations is proposed for the structural transformation H 0.27V 0.27W 0.73O 3→V 0.27W 0.73O 2.865.

Spectroscopic investigation of 2.0 μm emission in Ho3+-doped fluoroindate glasses

International Nuclear Information System (INIS)

Oliveira, S L; Bell, M J V; Florez, A; Nunes, L A O

2006-01-01

In this paper we report the optical characterization of Ho 3+ -doped fluoroindate glasses with the following composition (40 - x)InF 3 -20SrF 2 -16BaF 2 -20ZnF 2 -2GdF 3 -2NaF-xHoF 3 with x = 1.0, 2.0, 2.5, 3.0, 4.0, 5.0, 6.0, 8.0 and 9.0 mol%. This investigation was done by means of absorption, fluorescence and lifetime measurements. The phenomenological intensity parameters Ω λ (λ = 2, 4, 6) were calculated using the standard Judd-Ofelt theory. In order to evaluate potential applications of the 5 I 7 → 5 I 8 Ho 3+ emission at 2.0 μm, the radiative lifetime, total transition rate and emission cross section were determined. The effect of Ho 3+ concentration on the fluorescence intensity and lifetimes was analysed. It was concluded that the non-radiative losses of the 5 I 7 level are mainly due to energy migration among Ho 3+ ions followed by energy transfer to quenching impurities

Tuning the magnetic phase transition and the magnetocaloric properties of La0.7Ca0.3MnO3 compounds through Sm-doping

Science.gov (United States)

Thanh, Tran Dang; Dung, Nguyen Thi; Van Dang, Nguyen; Bau, Le Viet; Piao, Hong-Guang; Phan, The Long; Huyen Yen, Pham Duc; Hau, Kieu Xuan; Kim, Dong-Hyun; Yu, Seong-Cho

2018-05-01

In this work, we point out that the width and the nature of the magnetic phase transition, TC value, and as well as magnetocaloric effect in La0.7-xSmxCa0.3MnO3 compounds can be easily modified through Sm-doped into La-site. With an increasing Sm concentration, a systematic decrease in the magnetization, TC, and magnetic entropy change (ΔSm) are observed. The Arrott-plot proveds that the samples with x = 0 and 0.1 undergoing a first-order phase transition. Meanwhile, sample x = 0.2 undergoes a second-order phase transition, which exhibits a high value of the relative cooling power (81.5 J/kg at ΔH = 10 kOe). An analysis of the critical behavior based on the modified Arrott plots method has been done for sample x = 0.2. The results proved a coexistence of the long- and short-range interactions in La0.5Sm0.2Ca0.3MnO3 compound.

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

International Nuclear Information System (INIS)

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

2014-01-01

The nanosize effects on magnetic field induced transitions in La 0.67−x Eu x Ca 0.33 MnO 3 (x=0.25 and 0.27) system are presented in this paper. The reduction in the particle size of the system shows drastic effects on the electrical transport properties leading to robustness of the charge ordering phenomenon. The metal–insulator transition found in bulk materials at low magnetic fields disappeared in nanoparticles of the same material and a high field induced metal–insulator transition emerged at lower temperatures. These results manifest a strong correlation between the chemical pressures induced by doping of various ions at A-site and nanosize related phenomenon. - Highlights: • Chemical pressure and nanosize effects on electrical transport studies of Eu doped LCMO system are reported. • Decrease in particle size resulted in drastic changes on electrical transport studies. • Metal–insulator transition found in bulk at low magnetic fields disappeared in nanoparticles

Towards Precision Measurement of the 21S0-31D2 Two-Photon Transition in Atomic Helium

Science.gov (United States)

Huang, Yi-Jan; Guan, Yu-Chan; Suen, Te-Hwei; Wang, Li-Bang; Shy, Jow-Tsong

2017-04-01

We intend to accurately measure the frequency for 2S-3D two-photon transition and to deduce the 2S ionization energy to an accuracy below 100 kHz from the theoretical calculation of the 3D state. In this talk, we present a precision measurement of the 21S0 -31D2 two-photon transition in atomic helium at 1009 nm. A master oscillator power amplifier (MOPA) is seeded by an external cavity diode laser (ECDL) is constructed to generate more than 700 mW laser power with TEM00 beam profile at 1009 nm. To observe the two-photon transition, a helium cell is placed inside a power enhancement optical cavity and the helium atoms at 21S metastable level are prepared by a pulsed RF discharge and monitor the 668 nm 31D2 to 21P1 fluorescence after RF discharge is turned off . The absolute frequency metrology of the ECDL is carried out by an Er-fiber optical frequency comb (OFC). The two-photon spectrum is obtained by tuning the repetition frequency of the OFC. The 21S0-31D2 frequency is determined to be 594414291.967 (80) MHz in He-4. More results will be presented at the annual meeting.

Temperature-induced valence transition in EuNi2(Si0.20Ge0.80)2 studied by hard X-ray photoemission spectroscopy

International Nuclear Information System (INIS)

Yamamoto, Kazuya; Kamakura, Nozomu; Taguchi, Munetaka; Chainani, Ashish; Takata, Yasutaka; Horiba, Koji; Shin, Shik; Ikenaga, Eiji; Mimura, Kojiro; Shiga, Masayuki; Wada, Hirofumi; Namatame, Hirofumi; Taniguchi, Masaki; Awaji, Mitsuhiro; Takeuchi, Akihisa; Nishino, Yoshinori; Miwa, Daigo; Tamasaku, Kenji; Ishikawa, Tetsuya; Kobayashi, Keisuke

2005-01-01

The temperature-induced mixed valence transition in EuNi 2 (Si 0.20 Ge 0.80 ) 2 has been investigated by hard X-ray (5940 eV) photoemission spectroscopy (HX-PES) for fractured surfaces, with a probing depth larger than 5 nm. The Eu 3d core-level states are studied below and above the critical valence transition temperature, T v = 80 K. The HX-PES spectra at 40 and 120 K show the mixed valence transition, with clear changes in the divalent and trivalent Eu 3d chemically shifted features. The Eu 3d HX-PES spectra indicate a mean valence of 2.70 ± 0.03 at 40 K which changes to 2.40 ± 0.03 at 120 K, in good accordance with the results of bulk Eu III -edge X-ray absorption spectroscopy measurements

Birefringence imaging of phase transitions: application to Na0.5Bi0.5TiO3

International Nuclear Information System (INIS)

Geday, M.; Kreisel, J.; Glazer, A.M.; Roleder, K.

2000-01-01

In recent years a number of imaging techniques to determine the optical properties of materials, either in reflection or in transmission, have been developed. Here the use of an imaging version of the so-called rotating-polarizer method in the study of phase transformations in crystals is demonstrated. This method creates false-coloured images representing the light transmission I 0 , the extinction angle φ (orientation of the optical indicatrix) and vertical stroke sin δ vertical stroke, a function of the retardation resulting from the birefringence (and a measure of the magnitude of optical anisotropy). When combined with a computer-controlled heating stage, this method provides an opportunity to create separate moving images of orientation and magnitude of optical anisotropy, showing the dynamics of twinning and domain-wall behaviour during temperature changes. It is believed that this is the first time that quantitative imaging of changes in birefringence has been used in this way to describe phase transitions. Two-phase transitions in a crystal of Na 0.5 Bi 0.5 TiO 3 (NBT) are presented as examples of the use of the system. (orig.)

X-ray emission, ablation pressure, and preheating for foils irradiated at 0. 26. mu. m wavelength

Energy Technology Data Exchange (ETDEWEB)

Pepin, H.; Fabbro, R.; Faral, B.; Amiranoff, F.; Virmont, J.; Cottet, F.; Romain, J.P.

1985-11-01

The x-ray emission, ablation pressure, and preheating for foils irradiated with a 0.26 ..mu..m laser at intensities approx.10/sup 15/ W cm/sup -2/ are studied. The foils are Al with various thicknesses, coated or uncoated with CH or Au. The x-ray emission and conversion efficiency are obtained with a multichannel x-ray diode spectrometer, the ablation pressures are deduced from shock transit times, and the rear temperatures are inferred from x-ray pyrometry. For thin foils (<<12 ..mu..m), the rear temperatures can be predicted reasonably well with the use of the front x-ray spectra. For thick foils shock preheating is dominant.

X-ray emission, ablation pressure, and preheating for foils irradiated at 0.26 μm wavelength

International Nuclear Information System (INIS)

Pepin, H.; Fabbro, R.; Faral, B.; Amiranoff, F.; Virmont, J.; Cottet, F.; Romain, J.P.

1985-01-01

The x-ray emission, ablation pressure, and preheating for foils irradiated with a 0.26 μm laser at intensities approx.10 15 W cm -2 are studied. The foils are Al with various thicknesses, coated or uncoated with CH or Au. The x-ray emission and conversion efficiency are obtained with a multichannel x-ray diode spectrometer, the ablation pressures are deduced from shock transit times, and the rear temperatures are inferred from x-ray pyrometry. For thin foils (<<12 μm), the rear temperatures can be predicted reasonably well with the use of the front x-ray spectra. For thick foils shock preheating is dominant

La transición de fase I4/mcm→Pm3m en Sr0.5Ba0.5HfO3-δ

Directory of Open Access Journals (Sweden)

Lamas, D.

2001-08-01

Full Text Available The effect of partial substitution of cations in AMO3 compounds have been studied because the physical properties and applications of these materials can be improved. In particular we are interested in the Sr1-xBaxHfO3 family. In SrHfO3 the phase transition to cubic structure has been observed to occur when the angle between two consecutive oxygen octahedra tends to zero. Instead in BaHfO3 no phase transition was observed. These facts were attributed to depend on the atomic radius of A cation. In this contribution the study of Sr0.5Ba0.5HfO3 oxide is shown. The compound was prepared by the high temperature solid state reaction method and analyzed by X-ray diffraction and Perturbed Angular Correlation (PAC Spectroscopy at different temperatures. Diffraction studies revealed that about 400-420º C a structural phase transition from I4/mcm to Pm3m occurred by tending to zero the rotation angle. By PAC this transition was also observed. In the cubic phase the electric field gradient EFG measured were produced by defects. The same model applied to interpreted the results of BaTi1-xHfxO3 and the atomic positions determined by X-ray diffraction were used. This calculation reproduces reasonably the temperature dependence of the EFG measured by PAC.Los AMO3, llamados perovskitas, forman una gran familia de compuestos que presentan a su vez diversas propiedades físicas así como enormes aplicaciones tecnológicas. Es posible expandir esta familia y sus propiedades y aplicaciones, sustituyendo los cationes Ay M originales por diferentes A’ y M’. En este trabajo presentamos el estudio del compuesto Sr1-xBaxHfO3 con x=0.5. El óxido fue preparado por el método de reacción en fase sólida. La muestra fue analizada por difracción de Rayos X y por espectroscopía de Correlaciones Angulares Perturbadas (PAC a diferentes temperaturas. El estudio cristalográfico del material reveló que entre 400 y 420ºC se produce la transición de fase de estructura I4

0 - π Quantum transition in a carbon nanotube Josephson junction: Universal phase dependence and orbital degeneracy

Science.gov (United States)

Delagrange, R.; Weil, R.; Kasumov, A.; Ferrier, M.; Bouchiat, H.; Deblock, R.

2018-05-01

In a quantum dot hybrid superconducting junction, the behavior of the supercurrent is dominated by Coulomb blockade physics, which determines the magnetic state of the dot. In particular, in a single level quantum dot singly occupied, the sign of the supercurrent can be reversed, giving rise to a π-junction. This 0 - π transition, corresponding to a singlet-doublet transition, is then driven by the gate voltage or by the superconducting phase in the case of strong competition between the superconducting proximity effect and Kondo correlations. In a two-level quantum dot, such as a clean carbon nanotube, 0- π transitions exist as well but, because more cotunneling processes are allowed, are not necessarily associated to a magnetic state transition of the dot. In this proceeding, after a review of 0- π transitions in Josephson junctions, we present measurements of current-phase relation in a clean carbon nanotube quantum dot, in the single and two-level regimes. In the single level regime, close to orbital degeneracy and in a regime of strong competition between local electronic correlations and superconducting proximity effect, we find that the phase diagram of the phase-dependent transition is a universal characteristic of a discontinuous level-crossing quantum transition at zero temperature. In the case where the two levels are involved, the nanotube Josephson current exhibits a continuous 0 - π transition, independent of the superconducting phase, revealing a different physical mechanism of the transition.

Frequency-modulation transient absorption spectrum of the HCCl A 1A double-prime(0,0,0)left-arrow X 1A'(0,0,0) transition

International Nuclear Information System (INIS)

Chang, B.; Sears, T.J.

1995-01-01

The rotationally resolved spectrum of the HCCl A 1 A double-prime(0,0,0)left-arrow X 1 A'(0,0,0) transition between 12 230 and 12 410 cm -1 was obtained for the first time at Doppler-limited resolution using a frequency-modulation (FM) transient absorption technique. Five major subbands (K a =0 left-arrow 1, 1 left-arrow 0, 1 left-arrow 2, 2 left-arrow 1, and 2 left-arrow 3) of HC 35 Cl and one subband (K a =0 left-arrow 1) of HC 37 Cl were observed and assigned. In addition, the forbidden subband (K a =0 left-arrow 0) of HC 35 Cl was also observed. Thus far, we have assigned most (more than 70%) of the strong lines. The analysis of these subbands determines the geometry for the HCCl A(0,0,0) level: angle HCCl=134.7 degree and R C-Cl =1.623 A while R C-H is fixed at the corresponding value of CH 2 . The height of the barrier to linearity was found to be approximately 2170 cm -1 above the vibrationless level of the A state. The rotational structure of this spectrum shows irregular perturbations. Both random and J-dependent (anomalous K-type doubling) effects were observed. As in methylene, the perturbations most likely arise from Renner--Teller effect between the two singlet states in combination with spin--orbit coupling between the singlet and triplet states

The influence of anharmonic vibrations of the core to M2-transition between low-lying states in 115Sn

International Nuclear Information System (INIS)

Sy Savane, Y.

1995-12-01

The influence of the anharmonicity of the core vibration, on the magnetic transition 11/2 - 1 → 7/2 + 1 in 115 Sn have been investigated in the frame of the quasiparticle-phonon nuclear model. The model wave function includes a ''quasiparticle + two phonons'' component. The performed numerical calculations show that those effects cannot explain the strong reduction of the M2-transition observed in the experiment. A full agreement with the experimental value is obtained with g eff s = 0.42g free s . (author). 10 refs, 2 figs, 1 tab

Optical transition radiation interferometry for A0 photoinjector

International Nuclear Information System (INIS)

Kazakevich, G.; Novosibirsk, IYF; Edwards, H.; Fliller, R.; Lebedev, V.; Nagaitsev, S.; Santucci, J.; Thurman-Keup, R.; Fermilab; Piot, P.; Fermilab; Northern Illinois U.; Li, J.; Tikhoplav, R.; UCLA

2007-01-01

A charged particle passing through the boundary of two medias with different permittivity values generates Transition Radiation (TR), [1]. The TR is caused by a variation of the particle electric field with variation of the permittivity. The TR for relativistic particles has a wide spectrum with a significant portion in the optical range. The Optical Transition Radiation (OTR) is widely used for a beam profile monitoring and measurements of a beam size. Moreover, OTR can be used to characterize the energy, energy spread and transverse angles in the beam by employing the interference of the OTR from two thin films [2] inserted in the beam trajectory. This method has been applied in number of works [3-5] demonstrating high results and good coincidence in measurements and calculations. In this paper we present and discuss in details a simulation of the interference pattern in several experimental setups. We consider the main optical effects, for diagnostics for the beam properties at A0 Photoinjector and the ILC module test area (NML) in a wide range of electron beam energy. In this paper, we first derive the OTR intensity formula for a single film at 90 degrees to the beam, then for two films at normal incidence, and finally with films at 45 degree incidence to the beam. The last section illustrates application with beam parameters like those at the A0 Photoinjector (electron energy 15 MeV)

Interband transitions in 106Pd, 152Sm, 152Gd and 182W

International Nuclear Information System (INIS)

Kartashov, V.M.; Oborovskij, A.I.; Troitskaya, A.G.

1990-01-01

Internal transitions in 106 Pd, 152 Sm, 152 Gd, 182 W nuclei, observed during decay of 152,152m Eu, 182,183 Ta, 106m Ag, are studied. The experimental characteristics of E0-transitions and E0-components of E0+M1+E2 type transitions in the studied nuclei, relative intensities of internal conversion electron lines during 182 Ta decay, multipolar composition and forbidden factor for 182 W and 183 W low-energy transitions, characteristics of transitions are presented

Ferroelectric properties and diffuse phase transition in (Pb,La)Zrsub(0.55)Tisub(0.45)O3 ceramics

International Nuclear Information System (INIS)

Wolters, M.

1976-01-01

A preparation technique for (Pb,La)Zrsub(0.55)Tisub(0.45)O 3 ceramics is described by which inhomogeneities are eliminated. Grain size effects are studied and ferroelectric-paraelectric phase-transitions are investigated by means of X-ray diffraction analysis and dielectric weak-field (permittivity) and high-field (dc bias and hysteresis) measurements

Structural phase transition and magnetic properties of double perovskites Ba2CaMO6 (M=W, Re, Os)

International Nuclear Information System (INIS)

Yamamura, Kazuhiro; Wakeshima, Makoto; Hinatsu, Yukio

2006-01-01

Structures and magnetic properties for double perovskites Ba 2 CaMO 6 (M=W, Re, Os) were investigated. Both Ba 2 CaReO 6 and Ba 2 CaWO 6 show structural phase transitions at low temperatures. For Ba 2 CaReO 6 , the second order transition from cubic Fm3-bar m to tetragonal I4/m has been observed near 120K. For Ba 2 CaWO 6 , the space group of the crystal structure is I4/m at 295K and the transition to monoclinic I2/m has been observed between 220K. Magnetic susceptibility measurements show that Ba 2 CaReO 6 (S=1/2) and Ba 2 CaOsO 6 (S=1) transform to an antiferromagnetic state below 15.4 and 51K, respectively. Anomalies corresponding to their structural phase transition and magnetic transition have been also observed through specific heat measurements

Direct measurement of the low temperature spin state transitions in La1-xSrxCoO3 (0.05 < x < 0.3)

Science.gov (United States)

Gulec, A.; Klie, R. F.

2014-12-01

Sr-doped LaCoO3 has a complex magnetic phase diagram, which is believed to be directly correlated to changes in the crystal structure and ordering of the Co3+ spin states. In this work, we study the low temperature Co3+-ion spin state transitions in Sr-doped LaCoO3 around the critical doping concentration where a metal to insulator transition has been observed using electron energy-loss spectroscopy of the O K-edge combined with the Co L-edge fine structure. We measure the local spin state of the Co3+-ions and we demonstrate that the Co3+ spin-state transition only occurs in La0.95Sr0.05CoO3 single-crystal materials in the temperature range accessible by LN2 in-situ cooling, while no structural symmetry change is observed. The presence of this low-temperature spin-state transition in La1-xSrxCoO3 (x < 0.17) has been proposed as the origin of the percolative magnetic ordering in doped LaCoO3.

First-order phase transition in the quantum spin glass at T=0

Energy Technology Data Exchange (ETDEWEB)

Viana, J. Roberto; Nogueira, Yamilles; Sousa, J. Ricardo de

2003-05-26

The van Hemmen model with transverse and random longitudinal field is studied to analyze the tricritical behavior in the quantum Ising spin glass at T=0. The free energy and order parameter are calculated for two types of probability distributions: Gaussian and bimodal. We obtain the phase diagram in the {omega}-H plane, where {omega} and H are the transverse and random longitudinal fields, respectively. For the case of Gaussian distribution the phase transition is of second order, while the bimodal distribution we observe second-order transition for high-transverse field and first-order transition for small transverse field, with a tricritical point in the phase diagram.

First-order phase transition in the quantum spin glass at T=0

International Nuclear Information System (INIS)

Viana, J. Roberto; Nogueira, Yamilles; Sousa, J. Ricardo de

2003-01-01

The van Hemmen model with transverse and random longitudinal field is studied to analyze the tricritical behavior in the quantum Ising spin glass at T=0. The free energy and order parameter are calculated for two types of probability distributions: Gaussian and bimodal. We obtain the phase diagram in the Ω-H plane, where Ω and H are the transverse and random longitudinal fields, respectively. For the case of Gaussian distribution the phase transition is of second order, while the bimodal distribution we observe second-order transition for high-transverse field and first-order transition for small transverse field, with a tricritical point in the phase diagram

Polar phase transitions in heteroepitaxial stabilized La0.5Y0.5AlO3 thin films

Science.gov (United States)

Liu, Shenghua; Zhang, Chunfeng; Zhu, Mengya; He, Qian; Chakhalian, Jak; Liu, Xiaoran; Borisevich, Albina; Wang, Xiaoyong; Xiao, Min

2017-10-01

We report on the fabrication of epitaxial La0.5Y0.5AlO3 ultrathin films on (001) LaAlO3 substrates. Structural characterizations by scanning transmission electron microscopy and x-ray diffraction confirm the high quality of the film with a - b + c - AlO6 octahedral tilt pattern. Unlike either of the nonpolar parent compound, LaAlO3 and YAlO3, second harmonic generation measurements on the thin films suggest a nonpolar-polar phase transition at T c near 500 K, and a polar-polar phase transition at T a near 160 K. By fitting the angular dependence of the second harmonic intensities, we further propose that the two polar structures can be assigned to the Pmc2 1 and Pmn2 1 space group, while the high temperature nonpolar structure belongs to the Pbnm space group.

Lattice study of the gluon propagator in momentum space

Energy Technology Data Exchange (ETDEWEB)

Bernard, C. (Department of Physics, Washington University, St. Louis, Missouri 63130 (United States)); Parrinello, C. (Physics Department, New York University, 4 Washington Place, New York, New York 10003 (United States) Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)); Soni, A. (Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States))

1994-02-01

We consider pure glue QCD at [beta]=5.7, [beta]=6.0, and [beta]=6.3. We evaluate the gluon propagator both in time at zero three-momentum and in momentum space. From the former quantity we obtain evidence for a dynamically generated effective mass, which at [beta]=6.0 and [beta]=6.3 increases with the time separation of the sources, in agreement with earlier results. The momentum space propagator [ital G]([ital k]) provides further evidence for mass generation. In particular, at [beta]=6.0, for 300 MeV[approx lt][ital k][approx lt]1 GeV, the propagator [ital G]([ital k]) can be fit to a continuum formula proposed by Gribov and others, which contains a mass scale [ital b], presumably related to the hadronization mass scale. For higher momenta Gribov's model no longer provides a good fit, as [ital G]([ital k]) tends rather to follow an inverse power law [approx]1/[ital k][sup 2+[gamma

Cubic-tetragonal phase transition in Ca sub 0 sub . sub 0 sub 4 Sr sub 0 sub . sub 9 sub 6 TiO sub 3 a combined specific heat and neutron diffraction study

CERN Document Server

Gallardo, M C; Romero, F J; Cerro, J D; Seifert, F; Redfern, S A T

2003-01-01

The specific heat corresponding to the tetragonal-to-cubic transition in Ca sub 0 sub . sub 0 sub 4 Sr sub 0 sub . sub 9 sub 6 TiO sub 3 perovskite has been measured by conduction calorimetry. The order parameter of the transition has been obtained by means of neutron diffraction at low temperatures. Comparison of calorimetric data with the evolution of the order parameter indicates that this transition seems to follow a mean field Landau potential as in SrTiO sub 3. The linear behaviour of the excess of entropy versus temperature suggests that a 2-4 Landau potential is sufficient to describe the transition.

Electric field-induced phase transitions in Li-modified Na{sub 0.5}K{sub 0.5}NbO{sub 3} at the polymorphic phase boundary

Energy Technology Data Exchange (ETDEWEB)

Iamsasri, Thanakorn; Jones, Jacob L., E-mail: jacobjones@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Tutuncu, Goknur [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Uthaisar, Chunmanus; Pojprapai, Soodkhet [School of Ceramic Engineering, Institute of Engineering, Suranaree University of Technology, Nakorn Ratchasima 30000 (Thailand); Wongsaenmai, Supattra [Program in Materials Science, Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand)

2015-01-14

The electric field-induced phase transitions in Li-modified Na{sub 0.5}K{sub 0.5}NbO{sub 3} at the polymorphic phase boundary (PPB) were observed using in situ X-ray diffraction. The ratio of monoclinic to tetragonal phase fraction was used as an indicator of the extent and reversibility of the phase transitions. The reversibility of the phase transition was greater in compositions further from the PPB. These results demonstrate that the field-induced phase transition is one of the origins of high piezoelectric properties in lead-free ferroelectric materials.

Structural study of (CdS/ZnSe)/BeTe superlattices for λ=1.55 μm intersubband transition

International Nuclear Information System (INIS)

Li, B.S.; Akimoto, R.; Akita, K.; Hasama, H.

2004-01-01

A (CdS/ZnSe)/BeTe superlattice (SL), based on wide band gap II-VI compounds, with a large band offset of 3.1 eV was grown on a GaAs (001) substrate using molecular-beam epitaxy and an intersubband transition (ISB-T) of 0.78 eV (λ=1.58 μm) with a full width at half maximum (FWHM) of 96 meV observed. We studied structural properties using high-resolution x-ray diffraction combined with dynamic simulation and found through the strain state in samples that a ZnSe/BeTe interface having a quaternary interface layer (ZnTe) 0.45 (BeSe) 0.55 is preferentially formed despite the promotion of one molecular layer (ML) ZnTe interface formation. Be-Se bonds thus replace the Zn-Te bond in the transition region. For the CdS/ZnSe interface, an approximately 1 ML Zn 0.75 Cd 0.25 S ternary layer accompanied by ∼1 ML Zn 0.85 Cd 0.15 Se forms at the transition region due to Cd diffusion. X-ray (002) ω/2θ scan curves for (CdS/ZnSe)/BeTe SLs show sharp, intense satellite peaks exceeding ten orders, indicating high structure quality. We obtained excellent agreement between experimental diffraction patterns and the calculated curve via dynamic simulation for (CdS/ZnSe)/BeTe SLs. The good fits allows us to identify structure parameters in (CdS/ZnSe)/BeTe SLs, which are consistent with results of high-resolution transmission electron microscopy measurement. Based on dynamic simulated results, we obtained a structure of (CdS/ZnSe)/Be 1-x Mg x Te (x=1.2%) with an average lattice constant a SL matching the GaAs substrate. An ISB-T located at wavelength λ=1.55 μm with a narrow FWHM of 90 meV was thus realized at room temperature

Industry 4.0, M2m, Iot&S - All Equal?

Science.gov (United States)

Dobrin, Carmen

2014-11-01

Similarity between Industry 4.0, M2M, IOT&S. Advantages and disadvantages obtained using this three important methods. Decreasing costs while components are getting smaller and smaller in a world with better networking. Influence of business management applications integrated in smart factory logistic. The most important impacts in merging virtual and real production world, with the improvement of best processes having the same goal: creating value by open innovation

Gastric emptying rate and small bowel transit time in patients with irritable bowel syndrome determined with 99mTc-labeled pellets and scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Nielsen, O.H.; Gjorup, T.; Christensen, F.N.

1986-12-01

A new method employing 99mTc-labeled pellets for determination of the gastric emptying rate and small bowel transit time is described. The participants were six normal subjects and 16 patients with irritable bowel syndrome (eight with diarrhea and eight with obstipation as the primary complaint). The gastric emptying rate was the same in the three groups. The patients in the obstipation group had a significantly longer small bowel transit time than the normals (P less than 0.02) and the patients in the diarrhea group (P less than 0.01). There was no demonstrable difference between the small bowel transit time in the normals and in the patients in the diarrhea group.

Gastric emptying rate and small bowel transit time in patients with irritable bowel syndrome determined with 99mTc-labeled pellets and scintigraphy

International Nuclear Information System (INIS)

Nielsen, O.H.; Gjorup, T.; Christensen, F.N.

1986-01-01

A new method employing 99mTc-labeled pellets for determination of the gastric emptying rate and small bowel transit time is described. The participants were six normal subjects and 16 patients with irritable bowel syndrome (eight with diarrhea and eight with obstipation as the primary complaint). The gastric emptying rate was the same in the three groups. The patients in the obstipation group had a significantly longer small bowel transit time than the normals (P less than 0.02) and the patients in the diarrhea group (P less than 0.01). There was no demonstrable difference between the small bowel transit time in the normals and in the patients in the diarrhea group

Process development report: 0.40-m primary burner system

International Nuclear Information System (INIS)

Young, D.T.

1978-04-01

Fluidized bed combustion is required in reprocessing the graphite-based fuel elements from high-temperature gas-cooled reactor (HTGR) cores. This burning process requires combustion of beds containing both large particles and very dense particles, and also of fine graphite particles which elutriate from the bed. This report documents the successful long-term operation of the 0.40-m primary burner in burning crushed fuel elements. The 0.40-m system operation is followed from its first short heatup test in September 1976 to a > 40-h burning campaign that processed 20 LHTGR blocks in September 1977. The 0.40-m perforated conical gas distributor, scaled up from the 0.20-m primary burner, has proven reliable in safely burning even the largest, densest adhered graphite/fuel particle clusters originating from the crushing of loaded fuel elements. Such clusters had never been fed to the 0.20-m system. Efficient combustion of graphite fines using the pressurized recycle technique was demonstrated throughout the long-duration operation required to reduce a high carbon fresh feed bed to a low carbon particle bed. Again, such operation had never been completed on the 0.20-m system from which the 0.40-m burner was scaled. The successful completion of the tests was due, in part, to implementation of significant equipment revisions which were suggested by both the initial 0.40-m system tests and by results of ongoing development work on the 0.2-m primary burner. These revisions included additional penetrations in the burner tube side-wall for above-bed fines recycle, replacement and deletion of several metal bellows with bellows of more reliable design, and improvements in designs for burner alignment and feeder mechanisms. 76 figures, 8 tables

ΔM/sub j/ transitions in homonuclear molecule scattering off corrugated surfaces. Square and rectangular lattice symmetry and purely repulsive interaction

International Nuclear Information System (INIS)

Proctor, T.R.; Kouri, D.J.; Gerber, R.B.

1984-01-01

In this paper, we present the first formal and computational studies of Δm/sub j/ transitions occurring in homonuclear molecule-corrugated surface collisions. The model potential is a pairwise additive one which correctly incorporates the fact that Δm/sub j/ transitions occur only for corrugated surfaces (provided the quantization axis is chosen to be the average surface normal). The principal results are: (a) Δm/sub j/ transitions are extremely sensitive to lattice symmetry; (b) strong selection rules obtain for specular scattering; (c) the magnitude of Δm/sub j/ -transition probabilities are strongly sensitive to surface corrugation; (d) the Δm/sub j/ transitions depend strongly on diffraction peak; (e) the ratio of molecular length to lattice dimension (r/a) has a strong influence on the magnitude of Δm/sub j/ -transition probabilities [with the probabilities increasing as (r/a) increases]; (f) Δm/sub j/ rainbows are predicted to occur as a function of the (r/a) ratio increases; (g) Δm/sub j/ transitions and the Δm/sub j/ rainbow are expected to accompany Δj-rotational rainbows; (h) such magnetic transition rainbows accompanying Δj rainbows are suggested as an explanation of recent experimental observations of quenching of NO polarization for larger Δj transitions in NO/Ag(111) scattering

Spitzer/MIPS 24 {mu}m OBSERVATIONS OF HD 209458b: THREE ECLIPSES, TWO AND A HALF TRANSITS, AND A PHASE CURVE CORRUPTED BY INSTRUMENTAL SENSITIVITY VARIATIONS

Energy Technology Data Exchange (ETDEWEB)

Crossfield, Ian J. M. [Department of Physics, and Astronomy, University of California, Los Angeles, CA 90095 (United States); Knutson, Heather [Caltech Division of Geological and Planetary Sciences, Pasadena, CA 91125 (United States); Fortney, Jonathan [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Showman, Adam P. [Department of Planetary Sciences and Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States); Cowan, Nicolas B. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Deming, Drake, E-mail: ianc@astro.ucla.edu [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)

2012-06-20

We report the results of an analysis of all Spitzer/MIPS 24 {mu}m observations of HD 209458b, one of the touchstone objects in the study of irradiated giant planet atmospheres. Altogether, we analyze two and a half transits, three eclipses, and a 58 hr near-continuous observation designed to detect the planet's thermal phase curve. The results of our analysis are: (1) a mean transit depth of 1.484% {+-} 0.033%, consistent with previous measurements and showing no evidence of variability in transit depth at the 3% level. (2) A mean eclipse depth of 0.338% {+-} 0.026%, somewhat higher than that previously reported for this system; this new value brings observations into better agreement with models. From this eclipse depth we estimate an average dayside brightness temperature of 1320 {+-} 80 K; the dayside flux shows no evidence of variability at the 12% level. (3) Eclipses in the system occur 32 {+-} 129 s earlier than would be expected from a circular orbit, which constrains the orbital quantity ecos {omega} to be 0.00004 {+-} 0.00033. This result is fully consistent with a circular orbit and sets an upper limit of 140 m s{sup -1} (3{sigma}) on any eccentricity-induced velocity offset during transit. The phase curve observations (including one of the transits) exhibit an anomalous trend similar to the detector ramp seen in previous Spitzer/IRAC observations; by modeling this ramp we recover the system parameters for this transit. The long-duration photometry which follows the ramp and transit exhibits a gradual {approx}0.2% decrease in flux over {approx}30 hr. This effect is similar to that seen in pre-launch calibration data taken with the 24 {mu}m array and is better fit by an instrumental model than a model invoking planetary emission. The large uncertainties associated with this poorly understood, likely instrumental effect prevent us from usefully constraining the planet's thermal phase curve. Our observations highlight the need for a thorough

Thermophysical Properties and Structural Transition of Hg(0.8)Cd(0.2)Te Melt

Science.gov (United States)

Li, C.; Scripa, R. N.; Ban, H.; Lin, B.; Su, C.; Lehoczky, S. L.

2004-01-01

Thermophysical properties, namely, density, viscosity, and electrical conductivity of Hg(sub o.8)Cd(sub 0.2)Te melt were measured as a function of temperature. A pycnometric method was used to measure the melt density in the temperature range of 1072 to 1122 K. The viscosity and electrical conductivity were simultaneously determined using a transient torque method from 1068 to 1132 K. The density result from this study is within 0.3% of the published data. However, the current viscosity result is approximately 30% lower than the existing data. The electrical conductivity of Hg(sub o.8)Cd(sub 0.2)Te melt as a function of temperature, which is not available in the literature, is also determined. The analysis of the temperature dependent electrical conductivity and the relationship between the kinematic viscosity and density indicated that the structure of the melt appeared to be homogeneous when the temperature was above 1090 K. A structural transition occurred in the Hg(sub 0.8)Cd(0.2)Te melt as the temperature was decreased from 1090 K to the liquidus temperature.

Effects of partial Mn-substitution on magnetic and magnetocaloric properties in Pr{sub 0.7}Ca{sub 0.3}Mn{sub 0.95}X{sub 0.05}O{sub 3} (Cr, Ni, Co and Fe) manganites

Energy Technology Data Exchange (ETDEWEB)

Selmi, A. [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Sfax University, B.P. 1171, 3000 Sfax (Tunisia); M’nassri, R., E-mail: rafik_mnassri@yahoo.fr [Higher Institute of Applied Sciences and Technology of Kasserine, Kairouan University, B.P. 471, 1200 Kasserine (Tunisia); Cheikhrouhou-Koubaa, W. [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Sfax University, B.P. 1171, 3000 Sfax (Tunisia); Chniba Boudjada, N. [Institut NEEL, B.P. 166, 38042 Grenoble Cedex 9 (France); Cheikhrouhou, A. [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Sfax University, B.P. 1171, 3000 Sfax (Tunisia)

2015-01-15

Highlights: • Pr{sub 0.7}Ca{sub 0.3}Mn{sub 0.95}X{sub 0.05}O{sub 3}(X = Cr, Ni, Co and Fe) ceramics were prepared by solid state method. • The manganite phases crystallize in an orthorhombic (Pnma) structure. • The samples exhibit a second order paramagnetic (PM)–ferromagnetic (FM) phase transition at the Curie temperature T{sub C}. • Maximum RCP equal to 405 J/kg observed for Pr{sub 0.7}Ca{sub 0.3}Mn{sub 0.95}Cr{sub 0.05}O{sub 3}. • Second order phase transition is confirmed by Arrott plots and universal curves of entropy change. • The experimental ΔS{sub M} are well predicted by the phenomenological universal curve. - Abstract: Structural, magnetic and magnetocaloric properties of Pr{sub 0.7}Ca{sub 0.3}Mn{sub 0.95}X{sub 0.05}O{sub 3}(X = Cr, Ni, Co and Fe) ceramics have been investigated by X-ray diffraction (XRD) and magnetic measurements. Powder samples have been elaborated using the solid state reaction method at high temperature. The Rietveld analysis of the powder X-ray diffraction shows that the samples crystallize in the orthorhombic structure with Pnma space group. Magnetic measurements show that all our materials exhibit a paramagnetic–ferromagnetic transition with decreasing temperature. The Arrott plots of ours materials reveal the occurrence of a second-order phase transition. The maximum values of magnetic entropy change |ΔS{sub M}{sup max}| are 2.92, 2.96, 3.1, and 2.38 J kg{sup −1} K{sup −1} and the relative cooling power (RCP) values are 405.8, 378.2, 352.2 and 337.4 J kg{sup −1} for a magnetic-field change from 0 to 5 T for Cr, Ni, Co and Fe respectively. The large RCP found in our substituted samples will be interesting for magnetic refrigeration over a wide temperature range ∼130 K around its paramagnetic to ferromagnetic transition temperature. With the scaling laws of ΔS{sub M}, the experimental ΔS{sub M} collapse onto a universal curve for several ceramics, where an average curve is obtained. With the

Structural phase transitions of BaNbxTi1-xO3(0.0≤x≤0.5) thin films

International Nuclear Information System (INIS)

Guo Haizhong; Liu Lifeng; Ding Shuo; Lu Huibin; Zhou Yueliang; Cheng Bolin; Chen Zhenghao

2004-01-01

The phase transition behavior of BaNb x Ti 1-x O 3 (BNTO) (0.0≤x≤0.50) thin films grown on MgO substrates by laser molecular beam epitaxy was systematically investigated by using x-ray diffraction (XRD) and micro-Raman spectroscopy. The asymmetric rocking XRD scan measurements show that with an increase of Nb-doped content, the lattice parameters c and a increase while c/a ratio decreases, indicating a decrease of tetragonality of the BNTO films. The intensity of Raman signal decreases and the width of the bands broaden with increase of Nb-doped content. The results of XRD and Raman spectra indicate that at room temperature BNTO thin films with Nb≤10 at. % have tetragonal structure, however, for Nb≥20 at. %, BNTO thin films exhibit typical disordering cubic structure

Internal conversion coefficients of M4 isomeric transitions in /sup 125/ /sup 127/ /sup 129/Te decay

Energy Technology Data Exchange (ETDEWEB)

Soni, S K; Kumar, A; Gupta, S L; Pancholi, S C [Delhi Univ. (India). Dept. of Physics and Astrophysics

1977-01-01

The internal conversion coefficients have been measured using a high resolution low energy Ge(Li) detector for the following M4 transitions: /sup 125/Te: 109.27 keV transition ..cap alpha..sub(T) = 357 +- 11; RG method, /sup 127/Te: 88,26 keV transition ..cap alpha..sub(K) = 484 +- 23; XPG method, /sup 129/Te: 105.50 keV transition ..cap alpha..sub(K) = 213 +- 10; XPG method. It is observed that these values are lower by 2.5-3.6% as compared with Hager and Seltzer's calculations. A comparison between experimental and theoretical ..cap alpha..sub(K) and ..cap alpha..sub(T) values for eleven M4 transitions shows that the experimental values are systematically lower.

Composition-induced structural phase transitions in the (Ba1-xLax)2In2O5+x (0=0.6) system

International Nuclear Information System (INIS)

Tenailleau, C.; Pring, A.; Moussa, S.M.; Liu, Y.; Withers, R.L.; Tarantino, S.; Zhang, M.; Carpenter, M.A.

2005-01-01

Composition-induced structural phase changes across the high temperature, fast oxide ion conducting (Ba 1-x La x ) 2 In 2 O 5+x , 0= orthorhombic transition, while the cubic->tetragonal transition could be continuous. Differences between the variation with composition of spectral parameters and of macroscopic strain parameters are consistent with a substantial order/disorder component for the transitions. There is also evidence for precursor effects within the cubic structure before symmetry is broken

First identification of the 02+ state in 30Mg via its E0 transition

International Nuclear Information System (INIS)

Schwerdtfeger, Wolfgang Norbert Erik

2008-01-01

The known 1789 keV level in 30 Mg turned out to be a candidate for the 0 2 + state due to its long lifetime of 3.9(4) ns and the absence of a γ transition to the ground state. This triggered our search on the 0 2 + →0 1 + E0 transition in 30 Mg following the β decay of 30 Na: β decay electrons were detected in a scintillation detector, while conversion electrons were focused onto a cooled Si(Li) detector using a Mini-Orange and detected with high resolution, which simultaneously suppresses the high background of β decay electrons. Due to the large Q value of the β decay of 30 Na (17.3 MeV) the suppression of the coincident background induced by high-energy γ rays and subsequently Compton-scattered electrons turned out to be the key challenge for the success of this experiment. In order to optimise the background suppression and thus the sensitivity to weak E0 transitions, offline test measurements using an 90 Y and a 152 Eu source were performed together with GEANT4 simulations. Resulting from these test measurements a highly sensitive experimental setup was designed and built, consequently minimising the amount of high-Z material in the target chamber, reducing X-ray production. As a by-product from test measurements the database value of the half-life of the 0 2 + state in 90 Zr could be corrected by more than 30 % to be t 1/2 =41(1) ns. Finally, in a β decay experiment at the ISOLDE facility at CERN the 0 2 + →0 1 + E0 transition in 30 Mg could be identified at the expected transition energy of 1788 keV proving for the first time shape coexistence at the borderline of the 'Island of Inversion'. This identification allows to determine the electric monopole strength as ρ 2 (E0)=26.2(7.5) x 10 -3 , indicating a rather weak mixing between the states in two potential minima in a simplified two-level mixing model. This result allows to extract the mixing amplitude between the two 0 + states as a=0.179(83). This experimental finding represents the first

Synthesis, Magnetization, and Electrical Transport Properties of Mn3Zn0.9Cu0.1N

Directory of Open Access Journals (Sweden)

Y. Yin

2013-01-01

Full Text Available We synthesized Mn3Zn0.9Cu0.1N by solid state reaction, and magnetic as well as electrical transport properties were investigated. It is found that Mn3Zn0.9Cu0.1N exhibits a first-order antiferromagnetism (AFM to paramagnetic (PM transition with the Néel temperature TN ~163 K, and substitution of Cu for Zn would favor ferromagnetism (FM state and weaken AFM ground state, leading to a convex curvature character of M(T curve. With high external fields 10 kOe–50 kOe, magnetic transition remains a robust AFM-PM feature while FM phase is completely suppressed. Thermal hysteresis of M(T under 500 Oe is also suppressed when the magnetic field exceeds 10 kOe. Mn3Zn0.9Cu0.1N exhibits a good metallic behavior except for a slope change around TN, which is closely related to AFM-PM magnetic transition. Compared with the first differential of resistivity with respect to temperature for (dρ/dTMn3ZnN in transition temperature range, the absolute value of (dρ/dTMn3Zn0.9Cu0.1N is much lower which is close to zero.

Pressure effect on magnetic and insulator-metal transition of La.sub.0.67./sub.Pb.sub.0.33./sub.Mn.sub.0.9./sub.Co.sub.0.1./sub.O.sub.2.97./sub. ceramic

Czech Academy of Sciences Publication Activity Database

Mihalik, M.; Zentková, M.; Antoňák, M.; Arnold, Zdeněk; Kamarád, Jiří; Skorokhod, Yuriy; Gritzner, G.; Kiss, L. F.

2012-01-01

Roč. 32, č. 1 (2012), s. 145-149 ISSN 0895-7959. [Conference of the European High Pressure Research Group (EHPRG) /49./. Budapest, 28.08.2011-02.09.2011] Grant - others:VEGA(SK) 2/0057/27 Institutional research plan: CEZ:AV0Z10100521 Keywords : magnetic transition: insulator-metal transition * hydrostatic pressure * manganite Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.901, year: 2012 www.tandfonline.com

Releasing metal catalysts via phase transition: (NiO)0.05-(SrTi0.8Nb0.2O3)0.95 as a redox stable anode material for solid oxide fuel cells.

Science.gov (United States)

Xiao, Guoliang; Wang, Siwei; Lin, Ye; Zhang, Yanxiang; An, Ke; Chen, Fanglin

2014-11-26

Donor-doped perovskite-type SrTiO3 experiences stoichiometric changes at high temperatures in different Po2 involving the formation of Sr or Ti-rich impurities. NiO is incorporated into the stoichiometric strontium titanate, SrTi0.8Nb0.2O3-δ (STN), to form an A-site deficient perovskite material, (NiO)0.05-(SrTi0.8Nb0.2O3)0.95 (Ni-STN), for balancing the phase transition. Metallic Ni nanoparticles can be released upon reduction instead of forming undesired secondary phases. This material design introduces a simple catalytic modification method with good compositional control of the ceramic backbones, by which transport property and durability of solid oxide fuel cell anodes are largely determined. Using Ni-STN as anodes for solid oxide fuel cells, enhanced catalytic activity and remarkable stability in redox cycling have been achieved. Electrolyte-supported cells with the cell configuration of Ni-STN-SDC anode, La0.8Sr0.2Ga0.87Mg0.13O3 (LSGM) electrolyte, and La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) cathode produce peak power densities of 612, 794, and 922 mW cm(-2) at 800, 850, and 900 °C, respectively, using H2 as the fuel and air as the oxidant. Minor degradation in fuel cell performance resulted from redox cycling can be recovered upon operating the fuel cells in H2. Such property makes Ni-STN a promising regenerative anode candidate for solid oxide fuel cells.

On the existence of a phase transition for QCD with three light quarks

International Nuclear Information System (INIS)

Brown, F.R.; Butler, F.P.; Chen, H.; Christ, N.H.; Dong, Z.; Schaffer, W.; Unger, L.I.; Vaccarino, A.

1990-01-01

We report full QCD simulations on a 16 3 x4 lattice. For two degenerate flavors no finite-temperature phase transition is found for quark masses of ma=0.01 and 0.025, where a is the lattice spacing, while for three degenerate flavors a first-order transition is easily seen for ma=0.025. Nature, with nearly massless up and down quarks and one heavier strange quark, lies between these two cases. For m u ,dda=0.025 and m s a=0.1 we find that m K /m ρ =0.46(1) and that no transition occurs, calling into question the existence of a QCD phase transition

First observation of the strongly forbidden transition 1S0 - 3P0 in Strontium, for an atomic clock with trapped atoms

International Nuclear Information System (INIS)

Courtillot, I.

2003-11-01

This thesis reports the first results towards the realization of an optical clock using trapped strontium atoms. This set up would combine advantages of the different approaches commonly used to develop an atomic frequency standard. The first part describes the cold atoms source which is implemented. A magneto-optical trap operating on the 1 S 0 - 1 P 1 transition at 461 nm is loaded from an atomic beam decelerated by a Zeeman slower. The 461 nm laser is obtained by sum-frequency mixing in a potassium titanyl phosphate (KTP) crystal. The second part is devoted to the different stages developed to achieve the direct excitation of the 1 S 0 - 3 P 0 clock transition in 87 Sr. This line has a theoretical natural width of 10 -3 Hz. Before this detection, we obtained an estimate of the resonance frequency by measuring absolute frequencies of several allowed optical transitions. (author)

The magnetic transition temperature tuned by strain in YMn0.9Ru0.1O3 thin films

Directory of Open Access Journals (Sweden)

L. P. Yang

2018-05-01

Full Text Available Epitaxial orthorhombic YMn0.9Ru0.1O3 films with different thickness have been grown on (001-SrTiO3 substrates by pulsed laser deposition (PLD. The crystal structure is well investigated by X-ray Diffraction. It is found that the out-of-plane parameter c slowly increases with decreasing thickness of samples because of the tensile strain between the films and substrates along c axis. The lengths of in-plane Mn-O bonds expand with the enhancement of strains, which is proved by Raman scatting. The magnetic measurements reveal that there exist two magnetic transition temperatures TN1 and TN2. The TN1 is close to that of orthorhombic YMnO3 bulk. With decreasing thickness of the films, TN1 keeps almost constant because of the small stain along c-axis. TN2, however, obviously increases from 117 K to 134 K, which could be related to the expansion of in-plane Mn-O bonds. Results show that the magnetic transition temperature of YMn0.9Ru0.1O3 films can be sensitively manipulated by the strain of the films.

Zeatin is indispensable for the G2-M transition in tobacco BY-2 cells.

Science.gov (United States)

Laureys, F; Dewitte, W; Witters, E; Van Montagu, M; Inzé, D; Van Onckelen, H

1998-04-10

The importance of N6-isoprenoid cytokinins in the G2-M transition of Nicotiana tabacum BY-2 cells was investigated. Both cytokinin biosynthesis and entry in mitosis were partially blocked by application at early or late G2 of lovastatin (10 microM), an inhibitor of mevalonic acid synthesis. LC-MS/MS quantification of endogenous cytokinins proved that lovastatin affects cytokinin biosynthesis by inhibiting HMG-CoA reductase. Out of eight different aminopurines and a synthetic auxin tested for their ability to override lovastatin inhibition of mitosis, only zeatin was active. Our data point to a key role for a well-defined cytokinin (here, zeatin) in the G2-M transition of tobacco BY-2 cells.

Dose rate, mitotic cycle duration, and sensitivity of cell transitions from G1 → S and G2 → M to protracted gamma radiation in root meristems

International Nuclear Information System (INIS)

Evans, L.S.; Hof, J.V.

1975-01-01

Experiments were designed to determine the relative radiosensitivity of the cell transition points of G1 → S and G2 → M in root meristems of several plant species. Label and mitotic indices and microspectrophotometry were used to measure the proportions of cells in each mitotic cycle stage in root meristems after protracted gamma radiation. The criterion of radiosensitivity was the dose rate needed to produce a tissue with less than 1 percent cells in S and none in M after 3 days of continuous exposure. The results show that DNA is the primary radiation target in proliferative root meristems and that the cycle duration stipulates the time interval of vulnerability. In each species, nonrandom reproducible cell proportions were established with 2C:4C:8C amounts of nuclear DNA after 3 days of exposure. Roots of Helianthus annuus, Crepis capillaris, and Tradescantia clone 02 had 80 percent cells with a 2C amount of DNA and 20 percent had a 4C amount of DNA. In these species the transition point of G1 → S was more radiosensitive than G2 → M. Roots of Pisum sativum and Triticum aestivum had cell proportions at 2C:4C:8C amounts of DNA in frequencies of 0.10 to 0.20:0.40 to 0.60:0.30 to 0.40. In these two species 0.30 to 0.40 cells underwent radiation-induced endoreduplication that resulted from a rapid inhibition of cell transit from G2 → M and a slower impairment of G1 → S. Cells increased from 2C to 4C and from 4C to 8C amounts of DNA during irradiation. The proportions of nuclei with 2C:4C:8C amounts of DNA were dependent in part upon the relative radiosensitivity of the G1 → S and G2 → M control points. The data show the relative radiosensitivity of the transition points from G1 → S and from G2 → M was species specific and unrelated to the cycle duration and mean nuclear DNA content of the plant species

Monopole conversion hidden by penetration effect in magnetic dipole transitions

International Nuclear Information System (INIS)

Bikit, I.; Anichin, I.; Marinkov, L.

1977-01-01

The 191 keV 197 Au nad 340 keV 233 U transitions are investigated and the effect of penetration into the M1-component is accounted for. Theoretical internal conversion coefficients (ICC) and electron parameters to account for the penetration effect have been obtained by interpolating the data of the Hager and Zeltzer tables. The ICC values and ratios are analyzed under the assumption that the 191 keV 197 Au transition has multipolarities M1 + E2 and E 0 +M1. A common overlapping occurs when the nuclear penetration parameter lambda for magnetic dipole transition is lambda = 34.2+-2.2. For the 340 keV 233 U transition the ICC has been found to equal αk=0.69+-0.07, and the relative conversion-line intensities have been determined. It is concluded that the 191 keV 197 Au nad 340 keV 233 U transitions involve an electric monopole component concealed by the penetration effect in the M1-conversion. The matrix elements of the E0-transition have been evaluated

Positron probes of the Ge(1 0 0) surface: The effects of surface reconstructions and electron-positron correlations on positron trapping and annihilation characteristics

International Nuclear Information System (INIS)

Fazleev, N.G.; Jung, E.; Weiss, A.H.

2007-01-01

Positron annihilation induced Auger electron spectroscopy (PAES) has been applied to study the Ge(1 0 0) surface. The high-resolution PAES spectrum from the Ge(1 0 0) surface displays several strong Auger peaks corresponding to M 4,5 N 1 N 2,3 , M 2,3 M 4,5 M 4,5 , M 2,3 M 4,5 V and M 1 M 4,5 M 4,5 Auger transitions. The integrated peak intensities of Auger transitions are used to obtain experimental annihilation probabilities for the Ge 3d and 3p core level electrons. These experimental results are analyzed by performing calculations of positron surface states and annihilation characteristics of surface trapped positrons with relevant Ge core-level electrons for the non-reconstructed and reconstructed Ge(1 0 0)-p(2 x 1), Ge(1 0 0)-p(2 x 2) and Ge(1 0 0)-c(4 x 2) surfaces. It is found that the positron surface state wave function extends into the Ge lattice in the regions where atoms are displaced from their ideal terminated positions due to reconstructions. Estimates of the positron binding energy and the positron annihilation characteristics reveal their sensitivity to the specific atomic structure of the topmost layers of Ge(1 0 0). A comparison with PAES data reveals an agreement with theoretical core annihilation probabilities for the Auger transitions considered

Transiting Exoplanet Monitoring Project (TEMP). IV. Refined System Parameters, Transit Timing Variations, and Orbital Stability of the Transiting Planetary System HAT-P-25

Science.gov (United States)

Wang, Xian-Yu; Wang, Songhu; Hinse, Tobias C.; Li, Kai; Wang, Yong-Hao; Laughlin, Gregory; Liu, Hui-Gen; Zhang, Hui; Wu, Zhen-Yu; Zhou, Xu; Zhou, Ji-Lin; Hu, Shao-Ming; Wu, Dong-Hong; Peng, Xi-Yan; Chen, Yuan-Yuan

2018-06-01

We present eight new light curves of the transiting extra-solar planet HAT-P-25b obtained from 2013 to 2016 with three telescopes at two observatories. We use the new light curves, along with recent literature material, to estimate the physical and orbital parameters of the transiting planet. Specifically, we determine the mid-transit times (T C ) and update the linear ephemeris, T C[0] = 2456418.80996 ± 0.00025 [BJDTDB] and P = 3.65281572 ± 0.00000095 days. We carry out a search for transit timing variations (TTVs), and find no significant TTV signal at the ΔT = 80 s-level, placing a limit on the possible strength of planet–planet interactions (TTVG). In the course of our analysis, we calculate the upper mass-limits of the potential nearby perturbers. Near the 1:2, 2:1, and 3:1 resonances with HAT-P-25b, perturbers with masses greater than 0.5, 0.3, and 0.5 M ⊕ respectively, can be excluded. Furthermore, based on the analysis of TTVs caused by light travel time effect (LTTE) we also eliminate the possibility that a long-period perturber exists with M p > 3000 MJ within a = 11.2 au of the parent star.

Effect of excess Ni on martensitic transition, exchange bias and inverse magnetocaloric effect in Ni{sub 2+x}Mn{sub 1.4−x}Sn{sub 0.6} alloy

Energy Technology Data Exchange (ETDEWEB)

Ray, Mayukh K., E-mail: mayukh.ray@saha.ac.in; Bagani, K.; Banerjee, S., E-mail: sangam.banerjee@saha.ac.in

2014-07-05

Highlights: • Excess Ni causes an increase in the martensite transition temperature. • The system Ni{sub 2+x}Mn{sub 1.4−x}Sn{sub 0.6} exhibit multifunctional properties. • The RCP and EB increases continuously with excess Ni concentration in the system. • Antiferromagnetic interaction increases with excess Ni concentration. - Abstract: The martensitic transition, exchange bias (EB) and inverse magnetocaloric effect (IMCE) of bulk Ni{sub 2+x}Mn{sub 1.4−x}Sn{sub 0.6} (x = 0, 0.06, 0.12, 0.18) Heusler alloy is investigated in this paper. Substitution of Mn by Ni causes an increase in the martensite transition temperature (T{sub M}), decrease in Curie temperature of austenite phase (T{sub C}{sup A}) and also a decrease in the saturation magnetic moment (M{sub sat}). While the decrease in T{sub C}{sup A} and M{sub sat} is explained by the dilution of the magnetic subsystems and on the other hand the increase in T{sub M} is due to the increase of valence electron concentration per atom (e/a). All the alloys shows EB effect below a certain temperature (T{sup ∗}) and EB field (H{sub EB}) value is almost thrice in magnitude for x = 0.18 sample compared to x = 0 sample at 5 K. In these alloys, Ni/Mn atoms at regular site couples antiferromagnetically (AFM) with the excess Ni atoms at Mn or Sn sites and this AFM coupling plays the key role in the observation of EB. For the IMCE, the change in magnetic entropy (ΔS{sub M}) initially increased with excess Ni concentration upto x = 0.12 but then a drastic fall in ΔS{sub M} value is observed for the sample x = 0.18 but the relative cooling power (RCP) value is increased continuously with the excess Ni concentration.

Radiotherapy or surgery for T2N0M0 glottic carcinoma?

International Nuclear Information System (INIS)

Stalpers, L.J.A.; Daal, W.A.J. van; Verbeek, A.L.M.

1989-01-01

Decision analysis was used to evaluate the results of treatment of T 2 N 0 M 0 glottic carcinoma as presented in the literature. Based on mean values for recurrence, salvage eligibility after recurrence and salvage success, the 5-year survival after radiotherapy and surgery proved to be almost identical, 85 and 86%. If the recurrence rates and the salvage rates were varied, a marginal advantage for surgery in small tumours and a major advantage in more extended tumours was seen if only survival is considered. To take the quality of speech into account, a utility analysis was performed. A utility scale was defined ranging from 0.0 as the value for death, to 1.0 for a successfully irradiated patient with preservation of normal speech. A utility of 0.99 or less for the laryngectomized patient would favour radiotherapy over surgery for all T 2 tumours. In patients with T 2b tumours and in extreme circumstances, e.g. if failure rates of radiotherapy are extremely low, an exact assessment of patient utilities may be pivotal. Under normal circumstances radiotherapy is preferred for T 2 N 0 M 0 glottic carcinoma if both survival and the quality of speech are taken into account. (author). 39 refs.; 5 figs.; 1 tab

Seismicity Precursors of the M6.0 2004 Parkfield and M7.0 1989Loma Prieta Earthquakes

Energy Technology Data Exchange (ETDEWEB)

Korneev, Valeri A.

2006-03-09

The M6.0 2004 Parkfield and M7.0 1989 Loma Prietastrike-slip earthquakes on the San Andreas Fault (SAF) were preceded byseismicity peaks occurring several months prior to the main events.Earthquakes directly within the SAF zone were intentionally excluded fromthe analysis because they manifest stress-release processes rather thanstress accumulation. The observed increase in seismicity is interpretedas a signature of the increasing stress level in the surrounding crust,whereas the peaks and the subsequent decrease in seismicity areattributed to damage-induced softening processes. Furthermore, in bothcases there is a distinctive zone of low seismic activity that surroundsthe epicentral region in the pre-event period. The increase of seismicityin the crust surrounding a potential future event and the development ofa low-seismicity epicentral zone can be regarded as promising precursoryinformation that could help signal the arrival of large earthquakes. TheGutenberg-Richter relationship (GRR) should allow extrapolation ofseismicity changes down to seismic noise level magnitudes. Thishypothesis is verified by comparison of seismic noise at 80 Hz with theParkfield M4 1993-1994 series, where noise peaks 5 months before theseries to about twice the background level.

VT Data - Lidar DSM (0.7m) 2015, Windham County

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) This metadata applies to the following collection area(s): Windham County 2015 0.7m; Eastern VT 2014 0.7m; Rutland/GI Counties 2013 0.7m; and...

Stress triggering of the Lushan M7. 0 earthquake by the Wenchuan Ms8. 0 earthquake

Directory of Open Access Journals (Sweden)

Wu Jianchao

2013-08-01

Full Text Available The Wenchuan Ms8. 0 earthquake and the Lushan M7. 0 earthquake occurred in the north and south segments of the Longmenshan nappe tectonic belt, respectively. Based on the focal mechanism and finite fault model of the Wenchuan Ms8. 0 earthquake, we calculated the coulomb failure stress change. The inverted coulomb stress changes based on the Nishimura and Chenji models both show that the Lushan M7. 0 earthquake occurred in the increased area of coulomb failure stress induced by the Wenchuan Ms8. 0 earthquake. The coulomb failure stress increased by approximately 0. 135 – 0. 152 bar in the source of the Lushan M7. 0 earthquake, which is far more than the stress triggering threshold. Therefore, the Lushan M7. 0 earthquake was most likely triggered by the coulomb failure stress change.

Critical parameters near the ferromagnetic-paramagnetic phase transition in La{sub 0.7}A{sub 0.3}(Mn{sub 1-x}b{sub x})O{sub 3} (A=Sr; B=Ti and Al; x=0.0 and 0.05) compounds

Energy Technology Data Exchange (ETDEWEB)

Khiem, N.V. [Hongduc University, 307 Lelai Street, Thanhhoa City (Viet Nam)], E-mail: nvkhiem2002@yahoo.com; Phong, P.T. [Institute of Materials Science, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi (Viet Nam); Bau, L.V. [Hongduc University, 307 Lelai Street, Thanhhoa City (Viet Nam); Nam, D.N.H.; Hong, L.V.; Phuc, N.X. [Institute of Materials Science, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi (Viet Nam)

2009-07-15

The critical parameters provide important information concerning the interaction mechanisms near the paramagnetic-to-ferromagnetic transition. In this paper, we present a thorough study for the critical behavior of La{sub 0.7}A{sub 0.3}(Mn{sub 1-x}B{sub x})O{sub 3} (A=Sr; B=Ti and Al; x=0.0 and 0.05) polycrystalline samples near ferromagnetic-paramagnetic phase transition temperature by analyzing isothermal magnetization data. We have analyzed our dc-magnetization data near the transition temperature with the help of the modified Arrot plot, Kouvel-Fisher method. We have determined the critical temperature T{sub C} and the critical parameters {beta}, {gamma} and {delta}. With the values of T{sub C}, {beta} and {gamma}, we plot Mx(1-T/T{sub C}){sup -{beta}} vs. Hx(1-T/T{sub C}){sup -{gamma}}. All the data collapse on one of the two curves. This suggests that the data below and above T{sub C} obey scaling, following a single equation of state. Critical parameters for x=0 and x{sub Ti}=0.05 samples are between those predicted for a 3D-Heisenberg model and mean-field theory and for x{sub Al}=0.05 samples the values obtained for the critical parameters are close to those predicted by the mean-field theory.

Dielectric and magnetic properties of Ba-, La- and Pb-doped Bi0.8Gd0.1M0.1Fe0.9Ti0.1O3 perovskite ceramics

Directory of Open Access Journals (Sweden)

Radheshyam Rai

2014-04-01

Full Text Available The multiferroic Bi0.8Gd0.1M0.1Fe0.9Ti0.1O3, (where M = Ba (DB, La (DL and Pb (DP has been synthesized by using solid-state reaction technique. Effects of Ba, La and Pb substitution on the structure, electrical and ferroelectric properties of Bi0.8Gd0.1M0.1Fe0.9Ti0.1O3 samples have been studied by performing X-ray diffraction, dielectric and magnetic measurements. The crystal structures of the ceramic samples have a tetragonal phase. The vibrating sample magnetometer (VSM measurement shows a significant change in the magnetic properties of Ba-doped Bi0.8Gd0.1M0.1Fe0.9Ti0.1O3 as compared to La- and Pb-doped ceramics. It is seen that coercive field (HC and remanent magnetization (MR increases with Ba-doped ceramics but decreases for La- and Pb-doped ceramics.

Detection and characterization of bacteriocin-producing Lactococcus lactis strains Detecção e caracterização de Lactococcus lactis produtores de bacteriocinas

Directory of Open Access Journals (Sweden)

Izildinha Moreno

1999-04-01

Full Text Available One hundred sixty seven strains of Lactococcus lactis were screened for bacteriocin production by well diffusion assay of GM17 agar. Fourteen (8.4% produced antimicrobial activity other than organic acids, bacteriophages or hydrogen peroxide. The frequency of bacteriocin production ranged from 2% in L. lactis subsp. cremoris up to 12% in L. lactis subsp. lactis. Antimicrobial activities were not observed in any strain of L. lactis subsp. lactis var. diacetylactis. Among thirteen bacteriocin-producing strains and two nisin-producing strains (L. lactis subsp. lactis ATCC 11454 and L. lactis subsp. lactis CNRZ 150, eight (53% were characterized as lactose-positive (Lac+ and proteinase-negative (Prt-. The bacteriocin-producing cultures were also characterized on the basis of plasmid content. All strains had 2 to 7 plasmids with molecular weights varying from 0.5 to 28.1 Mdal. Four strains (ITAL 435, ITAL 436, ITAL 437 and ITAL 438 showed identical profiles and the other were quite distinct.Um total de 167 linhagens de L. lactis foi selecionado para os testes de produção de bacteriocinas pelo método de difusão em poços em agar GM17. Desse total, 14 (8.4% produziram substâncias inibidoras que não foram associadas com ácidos orgânicos, peróxido de hidrogênio e bacteriófagos. A frequência de produção de bacteriocinas variou de 2% em L. lactis subsp. cremoris a 12% em L. lactis subsp. lactis. Nenhuma das linhagens de L. lactis subsp. lactis var. diacetylactis produziu substâncias inibidoras. De 13 linhagens produtoras de bacteriocinas e duas de nisina (L. lactis subsp. lactis ATCC 11454 e L. lactis subsp. lactis CNRZ 150, 8 (53% foram caracterizadas como lactose-positivas (Lac+ e proteinase-negativas (Prt-. As linhagens produtoras de bacteriocinas também foram caracterizadas no seu conteúdo de plasmídios. Elas apresentaram de 2 a 7 plasmídios, com pesos moleculares aproximados de 0.5 a 28.1 Mdal. Quatro linhagens (ITAL 435, ITAL 436

Dielectric properties in the vicinity of the ferroelectric phase transition in a mixed crystal of deuterated betaine phosphate{sub 0.03} betaine phosphite{sub 0.97}

Energy Technology Data Exchange (ETDEWEB)

Banys, J.; Macutkevic, J.; Kajokas, A.; Brilingas, A.; Grigas, J. [Faculty of Physics, Vilnius University, Sauletekio 9, Vilnius 2040 (Lithuania); Klimm, C.; Voelkel, G. [Fakultaet fuer Physik und Geowissenschaften, Universitaet Leipzig, Linnestr. 5, 04103 Leipzig (Germany)

2004-02-01

The dielectric behaviour of ferroelectric hydrogen bonded deuterated betaine phosphate{sub 0.03} betaine phosphite{sub 0.97} (DBP{sub 0.03}DBPI{sub 0.97})is investigated in the region of the ferroelectric phase transition. Dielectric dispersion is investigated in the frequency range up to 12 GHz. The dielectric dynamics shows a critical slowing down. The frequency of the relaxational soft mode in the paraelectric phase varies according to the quasi-one-dimensional Ising model and decreases up to 0.31 GHz at the phase transition temperature (T{sub C}=272 K). The obtained activation energy for the deuteron flipping motion {delta}U=2.3kT{sub C}=0.054 eV shows the order-disorder character of the ferroelectric phase transition. The spontaneous polarisation, obtained from pyroelectric measurements, is also well explained using the quasi-one-dimensional Ising model. At low temperatures, the freezing phenomena in DBP{sub 0.03}DBPI{sub 0.97} revealed the complex dielectric permittivity behaviour characteristic for the transition into the dipolar glass state. The activation energy of this low temperature process was found to be E{sub b}=1297 K (0.041 eV) and the glass temperature was estimated to 73 K. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Positron probes of the Ge(1 0 0) surface: The effects of surface reconstructions and electron-positron correlations on positron trapping and annihilation characteristics

Energy Technology Data Exchange (ETDEWEB)

Fazleev, N.G. [Department of Physics, University of Texas at Arlington, Box 19059, Arlington, TX 76019-0059 (United States) and Department of Physics, Kazan State University, Kazan 420008 (Russian Federation)]. E-mail: Fazleev@uta.edu; Jung, E. [Department of Physics, University of Texas at Arlington, Box 19059, Arlington, TX 76019-0059 (United States); Weiss, A.H. [Department of Physics, University of Texas at Arlington, Box 19059, Arlington, TX 76019-0059 (United States)

2007-08-15

Positron annihilation induced Auger electron spectroscopy (PAES) has been applied to study the Ge(1 0 0) surface. The high-resolution PAES spectrum from the Ge(1 0 0) surface displays several strong Auger peaks corresponding to M{sub 4,5}N{sub 1}N{sub 2,3}, M{sub 2,3}M{sub 4,5}M{sub 4,5}, M{sub 2,3}M{sub 4,5}V and M{sub 1}M{sub 4,5}M{sub 4,5} Auger transitions. The integrated peak intensities of Auger transitions are used to obtain experimental annihilation probabilities for the Ge 3d and 3p core level electrons. These experimental results are analyzed by performing calculations of positron surface states and annihilation characteristics of surface trapped positrons with relevant Ge core-level electrons for the non-reconstructed and reconstructed Ge(1 0 0)-p(2 x 1), Ge(1 0 0)-p(2 x 2) and Ge(1 0 0)-c(4 x 2) surfaces. It is found that the positron surface state wave function extends into the Ge lattice in the regions where atoms are displaced from their ideal terminated positions due to reconstructions. Estimates of the positron binding energy and the positron annihilation characteristics reveal their sensitivity to the specific atomic structure of the topmost layers of Ge(1 0 0). A comparison with PAES data reveals an agreement with theoretical core annihilation probabilities for the Auger transitions considered.

Stable Ferroelectric Behavior of Nb-Modified Bi0.5K0.5TiO3-Bi(Mg0.5Ti0.5)O3 Lead-Free Relaxor Ferroelectric Ceramics

Science.gov (United States)

Zaman, Arif; Malik, Rizwan Ahmed; Maqbool, Adnan; Hussain, Ali; Ahmed, Tanveer; Song, Tae Kwon; Kim, Won-Jeong; Kim, Myong-Ho

2018-03-01

Crystal structure, dielectric, ferroelectric, piezoelectric, and electric field-induced strain properties of lead-free Nb-modified 0.96Bi0.5K0.5TiO3-0.04Bi(Mg0.5Ti0.5)O3 (BKT-BMT) piezoelectric ceramics were investigated. Crystal structure analysis showed a gradual phase transition from tetragonal to pseudocubic phase with increasing Nb content. The optimal piezoelectric property of small-signal d 33 was enhanced up to ˜ 68 pC/N with a lower coercive field ( E c) of ˜ 22 kV/cm and an improved remnant polarization ( P r) of ˜ 13 μC/cm2 for x = 0.020. A relaxor-like behavior with a frequency-dependent Curie temperature T m was observed, and a high T m around 320°C was obtained in the investigated system. This study suggests that the ferroelectric properties of BKT-BMT was significantly improved by means of Nb substitution. The possible shift of depolarization temperature T d toward high temperature T m may have triggered the spontaneous relaxor to ferroelectric phase transition with long-range ferroelectric order without any traces of a nonergodic relaxor state in contradiction with Bi0.5Na0.5TiO3-based systems. The possible enhancement in ferroelectric and piezoelectric properties near the critical composition x = 0.020 may be attributed to the increased anharmonicity of lattice vibrations which may facilitate the observed phase transition from a low-symmetry tetragonal to a high-symmetry cubic phase with a decrease in the lattice anisotropy of an undoped sample. This highly flexible (at a unit cell level) narrow compositional range triggers the enhancement of d 33 and P r values.

Abnormal magnetization and field-induced transition in (La{sub 0.73}Bi{sub 0.27}){sub 0.67}Ca{sub 0.33}MnO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Li Haina; Wu Yuying [Department of Physics, Huazhong University of Science and Technology, Wuhan (China); Yu Hongwei [College of Science, Naval University of Engineering, Wuhan (China); Chen Ziyu [Department of Physics, Huazhong University of Science and Technology, Wuhan (China); Huang Yan; Wang Shaoliang; Li Liang [Wuhan Pulsed High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan (China); Xia Zhengcai, E-mail: xia9020@hust.edu.c [Wuhan Pulsed High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan (China)

2010-09-15

The magnetic field dependence of magnetization of Bi doped manganites (La{sub 1-x}Bi{sub x}){sub 0.67}Ca{sub 0.33}MnO{sub 3} (x=0.27) was investigated at different temperatures with a pulsed high magnetic field. A metamagnetic transition was observed in the magnetization measurement, which revealed the coexistence of charge ordering (CO) and ferromagnetic (FM) phases. With decreasing magnetic field, the field-induced FM phases remained stable even when the magnetic field decreased to zero. This result suggests that ferromagnetic interactions are enhanced due to the effect of the pulsed high magnetic field, which makes the doped manganites a good system for magnetoresistance materials.

Giant magnetoimpedance and high frequency electrical detection of magnetic transition in La{sub 0.75}Sr{sub 0.25}MnO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Barik, S K; Rebello, A; Tan, C L; Mahendiran, R [Department of Physics, Faculty of Science, National University of Singapore 2 Science Drive 3, Singapore-117542 (Singapore)

2008-01-21

We show that high frequency electrical transport is an efficient technique for detecting the magnetic transition hidden by the scattering of charges at grain boundaries in colossal magnetoresistive oxides, even in the absence of any external magnetic field. The dc resistivity which shows only a weak anomaly at the Curie temperature in La{sub 0.75}Sr{sub 0.25} MnO{sub 3} transforms into abrupt jumps in both resistive (Z') and reactive (Z-prime) parts of the ac impedance, Z(f, T, H) = Z'(f, T, H) + jZ-prime(f, T, H) at higher frequencies (f = 0.1-5 MHz). The anomaly in Z' and Z-prime at T{sub C} decreases as much as 19% and 15%, respectively, in a dc magnetic field of H 65 mT compared with 1% dc magnetoresistance, suggesting a possible giant low-field magnetoimpedance effect which could be exploited for room temperature practical applications. We interpret our observations due to changes in the magnetic penetration depth induced by the spontaneous ordering of spins and by the applied field. (fast track communication)

Acoustic Emission Precursors of M6.0 2004 Parkfield and M7.0 1989Loma Prieta Earthquakes

Energy Technology Data Exchange (ETDEWEB)

Korneev, Valeri

2005-02-01

Two recent strike-slip earthquakes on the San Andreas Fault(SAF) in California, the M6.0 2004 Parkfield and M7.0 1989 Loma Prietaevents, revealed peaks in the acoustic emission (AE) activity in thesurrounding crust several months prior to the main events. Earthquakesdirectly within the SAF zone were intentionally excluded from theanalysis. The observed increase in AE is assumed to be a signature of theincreasing stress level in the surrounding crust, while the peak andsubsequent decrease in AE starting several months prior to the mainevents is attributed to damage-induced softening processes as discussedherein. Further, distinctive zones of low seismic activity surroundingthe epicentral regions in the pre-event time period are present for thetwo studied events. Both AE increases in the crust surrounding apotential future event and the development of a low-seismicity epicentralzone can be regarded as promising precursory information that could helpsignal the arrival of large earthquakes.

Absolute E0 and E2 transition rates and collective states in 116Sn

International Nuclear Information System (INIS)

Kantele, J.; Julin, R.; Luontama, M.; Passoja, A.; Poikolainen, T.; Baecklin, A.; Jonsson, N.-G.

1978-08-01

Absolute E0 and E2 transition rates in 116 Sn have been measured using several newly developed techniques. Many E2 transitions are observed to have a collective character with B(E2) values of up to 60 W.u. The presence of deformed excited states in 116 Sn is discussed in view of the results obtained. (author)

The quorum-quenching lactonase from Alicyclobacter acidoterrestris : purification, kinetic characterization, crystallization and crystallographic analysis

Energy Technology Data Exchange (ETDEWEB)

Bergonzi, Celine; Schwab, Michael; Chabriere, Eric; Elias, Mikael

2017-07-26

Lactonases comprise a class of enzymes that hydrolyze lactones, including acyl-homoserine lactones (AHLs); the latter are used as chemical signaling molecules by numerous Gram-negative bacteria. Lactonases have therefore been demonstrated to quench AHL-based bacterial communication. In particular, lactonases are capable of inhibiting bacterial behaviors that depend on these chemicals, such as the formation of biofilms or the expression of virulence factors. A novel representative from the metallo-β-lactamase superfamily, named AaL, was isolated from the thermoacidophilic bacterium<italic>Alicyclobacter acidoterrestrisitalic>. Kinetic characterization proves AaL to be a proficient lactonase, with catalytic efficiencies (<italic>k_cat/K_m) against AHLs in the region of 10⁵<italic>M>^-1s^-1. AaL exhibits a very broad substrate specificity. Its structure is expected to reveal the molecular determinants for its substrate binding and specificity, as well as to provide grounds for future protein-engineering projects. Here, the expression, purification, characterization, crystallization and X-ray diffraction data collection of AaL at 1.65Å resolution are reported.

Luminescence properties of Sr{sub 3-x-3y/2}M{sub x}Ce{sub y}AlO{sub 4}F (M=Ca, Ba, 0{<=}x{<=}0.9, 0.001{<=}y{<=}0.05) phosphors

Energy Technology Data Exchange (ETDEWEB)

Choi, Hye-Min [Department of Engineering in Energy and Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Park, Sangmoon, E-mail: spark@silla.ac.kr [Department of Engineering in Energy and Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of)

2012-09-15

Luminescent materials composed of Sr{sub 3-x-3y/2}M{sub x}Ce{sub y}AlO{sub 4}F (M=Ca, Ba, 0{<=}x{<=}0.9, 0.001{<=}y{<=}0.05) were prepared by the solid-state reaction method. X-ray diffraction (XRD) patterns of the obtained oxyfluorides are exhibited for indexing peak positions. Dynamic excitation and emission spectra of the Ce{sup 3+}-activated oxyfluoride phosphors are clearly monitored. The critical emission quenching as a function of Ce{sup 3+} contents in Sr{sub 2.5-3y/2}M{sub 0.5}Ce{sub y}AlO{sub 4}F phosphors is revealed at quite low concentrations of the activator. CIE coordinates of blue and green Sr{sub 2.5-3y/2}M{sub 0.5}Ce{sub y}AlO{sub 4}F phosphors are clearly measured. The relative quantum efficiency of Sr{sub 2.4985}Ca{sub 0.5}Ce{sub 0.005}AlO{sub 4}F based on the integrated emission is determined. The Sr{sub 3-x-3y/2}M{sub x}Ce{sub y}AlO{sub 4}F phosphors excited near 410 nm light could be prominent phosphors in applications of NUV-LED. - Highlights: Black-Right-Pointing-Pointer Blue and green emitting oxyfluoride phosphors are excitated near 410 nm Black-Right-Pointing-Pointer Ce{sup 3+}-activated oxyfluoride phosphors are quite effective to prepare white light for near-UV LED applications. Black-Right-Pointing-Pointer Gradual substitution of Ce{sup 3+} content in the oxyfluoride hosts changes CIE values.

Esophageal transit scintigraphy in healthy volunteers using TC-99M sulphur colloid semisolid jelly

International Nuclear Information System (INIS)

Ashwani Sood; Kumar, U.; Gambhir, S.; Sewatkar, A.B.; Kheruka, S.C.; Dube, V.

2004-01-01

Functional symptoms caused by esophageal motor disorders are very common. The esophageal transit scintigraphy has been done using liquid and solid meals to understand pathophysiology of esophageal motor disorders better. The present study was aimed to develop and standardize a stable and easily acceptable radioactive semisolid meal for esophageal transit scintigraphy. Semisolid jelly incorporated with Tc-99m sulphur colloid was prepared from the commercially available edible jelly powder-containing gelatin. The tracer stability was investigated by in-vitro method up to 4 hours to test the affinity of tracer and mechanical stability of semisolid meal. The amount of semisolid meal per bolus was also standardized in relation to ease of swallowing and free passage of it through whole of esophagus. The additional objective was to establish the normal esophageal transit scintigraphic parameters. Materials and methods: A total of 31 normal volunteers were studied. The esophageal transit scintigraphy was performed in supine and sitting positions thrice using single bolus of 2 gm semisolid jelly containing 7.4 MBq (200uCi) of tracer for the acquisition period of 192 seconds. The esophageal emptying time for 50% (T50) and for 90% (T90) were calculated by computer analysis in addition to generation of condensed dynamic images. Results: The 50% and 90% whole esophageal emptying time are given below in the table in sitting and supine positions respectively.(P<0.05). Conclusions: Condensed dynamic images revealed normal transit pattern without delay or stasis and fragmentation of bolus through the esophagus. The stability and homogeneity of tracer in the semisolid meal provided a simple and reliable method for carrying out esophageal transit scintigraphy. It was found that this bolus was well accepted by normal volunteers and values obtained were well within the acceptable range. Thus we established the normal values in our laboratory and also standardized a semisolid meal with

Temperature-dependent Raman spectra and electrical properties of 0.69Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.31PbTiO{sub 3} single crystals

Energy Technology Data Exchange (ETDEWEB)

Fang, Bijun [Changzhou University, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou (China); Liu, Xing [Changzhou University, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou (China); Chinese Academy of Sciences, Key Laboratory of Inorganic Function Material and Device, Shanghai (China); Li, Xiaobing; Zhao, Xiangyong; Luo, Haosu [Chinese Academy of Sciences, Key Laboratory of Inorganic Function Material and Device, Shanghai (China); Ding, Jianning [Changzhou University, School of Materials Science and Engineering, Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou (China); Jiangsu University, School of Material Science and Engineering, Zhenjiang (China)

2016-09-15

The temperature-dependent Raman spectra and electrical properties of the 0.69Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.31PbTiO{sub 3} (0.69PMN-0.31PT) single crystals were investigated. Based on the group theory, the poled 0.69PMN-0.31PT single crystals belong to the monoclinic crystal system, which was confirmed by the room-temperature Raman spectra. The 0.69PMN-0.31PT single crystals experience successive structural phase transitions, i.e., a monoclinic-tetragonal (FE{sub M}-FE{sub T}) phase transition at T{sub M-T} and a tetragonal-cubic (FE{sub T}-P{sub C}) phase transition at T{sub m} determined by the dielectric measurement. Due to the enhancement of long-range order, their FE{sub M}-FE{sub T} phase transition becomes more obvious after the poling process. The wavenumbers and line widths of the 271, 502, 575, 795 cm{sup -1} Raman modes, and the intensity ratios of I{sub 271cm}{sup {sub -}{sub 1}}/I{sub 795cm}{sup {sub -}{sub 1}} and I{sub 502cm}{sup {sub -}{sub 1}}/I{sub 575cm}{sup {sub -}{sub 1}} exhibit obvious anomalies around T{sub M-T} and T{sub m}, which are closely related to the FE{sub M}-FE{sub T} and FE{sub T}-P{sub C} phase transitions. The temperature and electric field (E)-induced phase transitions are observed in the unipolar strain-E (S-E) curves. The converse piezoelectric constant (d{sub 33}), maximum strain value (S{sub max}%) and longitudinal electrostrictive coefficient (Q) increase considerably around the ferroelectric phase transition temperature T{sub M-T}. (orig.)

Phase transitions and electrical characterizations of (K 0.5Na 0.5) 2x(Sr 0.6Ba 0.4) 5-xNb 10O 30 (KNSBN) ceramics with 'unfilled' and 'filled' tetragonal tungsten-bronze (TTB) crystal structure

KAUST Repository

Yao, Yingbang

2012-12-01

Alkali-doped strontium barium niobate (K 0.5Na 0.5) 2x(Sr 0.6Ba 0.4) 5-xNb 10O 30 (KNSBN) ceramics has been prepared by a conventional solid-state reaction method. The alkali-dopant concentration x has been varied from 0.24 to 1.15 so that the crystal structure was transformed from \\'unfilled\\' to \\'filled\\' tetragonal tungsten-bronze (TTB) structure. Apart from the change in the structural properties, the effects of the alkali-dopants on the phase transition as well as ferroelectric, piezoelectric and pyroelectric properties have also been investigated. Phase transitions have been studied in the temperature range of -200°C to 350°C. The origins of these phase transitions are discussed. The addition of the alkali-dopants enhances the ferroelectric, piezoelectric and pyroelectric properties of the KNSBN ceramics. Alkali-doping also favors abnormal grain growth and thus results in a porous microstructure, which might contribute to the enhancement of the pyroelectric performance. © 2012 Elsevier Ltd.

Phase transitions and electrical characterizations of (K 0.5Na 0.5) 2x(Sr 0.6Ba 0.4) 5-xNb 10O 30 (KNSBN) ceramics with 'unfilled' and 'filled' tetragonal tungsten-bronze (TTB) crystal structure

KAUST Repository

Yao, Yingbang; Mak, C. L.; Ploss, Bernd

2012-01-01

Alkali-doped strontium barium niobate (K 0.5Na 0.5) 2x(Sr 0.6Ba 0.4) 5-xNb 10O 30 (KNSBN) ceramics has been prepared by a conventional solid-state reaction method. The alkali-dopant concentration x has been varied from 0.24 to 1.15 so that the crystal structure was transformed from 'unfilled' to 'filled' tetragonal tungsten-bronze (TTB) structure. Apart from the change in the structural properties, the effects of the alkali-dopants on the phase transition as well as ferroelectric, piezoelectric and pyroelectric properties have also been investigated. Phase transitions have been studied in the temperature range of -200°C to 350°C. The origins of these phase transitions are discussed. The addition of the alkali-dopants enhances the ferroelectric, piezoelectric and pyroelectric properties of the KNSBN ceramics. Alkali-doping also favors abnormal grain growth and thus results in a porous microstructure, which might contribute to the enhancement of the pyroelectric performance. © 2012 Elsevier Ltd.

Dependence of magnetic and structural properties of Ni 0.5 M 0.5 Fe ...

African Journals Online (AJOL)

Ni0.5M0.5Fe2O4 (M = Co, Cu) ferrite nanoparticles were synthesized using citrate precursor method. The citrate precursor was annealed at temperatures 400oC, 450oC, 500oC and 550oC. The annealed powders were characterized using X-ray diffractometer (XRD) and vibrating sample magnetometer (VSM). Observed ...

E2 and M1 transition strengths in heavy deformed nuclei revisited

International Nuclear Information System (INIS)

Draayer, J.P.; Popa, G.; Hirsch, J.G.; Vargas, C.E.

2003-01-01

An update on the status of pseudo-SU(3) shell-model calculations in strongly deformed nuclei in the rare earth region is presented. Representative results for energy levels as well as E2 (quadrupole) and M1 (scissors) transitions strengths in 162 Dy (even-even) and 163 Dy (odd-mass) are given. The calculations use realistic single-particle energies and quadrupole-quadrupole and pairing interaction strengths fixed from systematics. The strengths of rotor-like terms included in the Hamiltonian- all small relative to the other terms in the interaction were adjusted to give an overall best fit to the energy spectra. The results present a paradox: for even-even nuclei (integer angular momentum) non-zero pseudo-spin configurations seems to be unimportant while for the odd-mass systems (half-integer angular momentum) pseudo-spin mixing is essential as spin-flip couplings appear to dominate the M1 transition strengths. (Author)

Evidence of spin transition and charge order in cobalt substituted La sub 0 sub . sub 7 Ca sub 0 sub . sub 3 MnO sub 3

CERN Document Server

Srivastava, C M; Gundurao, T K; Nigam, A K; Bahadur, D

2003-01-01

The transport and magnetic studies of a series of compounds having the general formula La sub 0 sub . sub 7 Ca sub 0 sub . sub 3 Mn sub 1 sub - sub x Co sub x O sub 3 (0.1 = 0.25 there is a clear spin transition at low temperature from the high to the low spin state of trivalent cobalt and this leads to change in ferromagnetic (FM) and antiferromagnetic (AFM) phases. For x >= 0.25 there are two transitions for each value of x: the upper one gives the FM and AFM spin arrangement depending upon whether the DE or the SE dominates; the lower one is obtained due to the transition from the high to the low spin state of the trivalent cobalt ion.

High temperature spin-glass-like transition in La0.67Sr0.33MnO3 nanofibers near the Curie point.

Science.gov (United States)

Lu, Ruie; Yang, Sen; Li, Yitong; Chen, Kaiyun; Jiang, Yun; Fu, Bi; Zhang, Yin; Zhou, Chao; Xu, Minwei; Zhou, Xuan

2017-06-28

The glassy transition of superparamagnetic (SPM) (r glass-like (SGL) behavior near the Curie point (T C ), i.e., T 0 = 330 K, in La 0.67 Sr 0.33 MnO 3 (LSMO) nanofibers (NFs) composed of nanoparticles beyond the SPM size (r ≫ r 0 ), resulting in a significant increase of the glass transition temperature. This SGL transition near the T C of bulk LSMO can be explained to be the scenario of locally ordered clusters embedded in a disordered host, in which the assembly of nanoparticles has a magnetic core-shell model driven by surface spin glass. The presence of a surface spin glass of nanoparticles was proved by the Almeida-Thouless line δT f ∝ H 2/3 , exchange bias, and reduced saturation magnetization of the NF system. Composite dynamics were found - that is, both the SPM and the super-spin-glass (SSG) behavior are found in such an NF system. The bifurcation of the zero-field-cooled (ZFC) and field-cooled (FC) magnetization vs. temperature curves at the ZFC peak, and the flatness of FC magnetization involve SSG, while the frequency-dependent ac susceptibility anomaly follows the Vogel-Fulcher law that implies weak dipole interactions of the SPM model. This finding can help us to find a way to search for high temperature spin glass materials.

A resonant ultrasound spectroscopy study of the phase transitions in Na0.75CoO2

Science.gov (United States)

Keppens, Veerle; Sergienko, Ivan; Jin, Rongying

2005-03-01

The layered transition metal oxides NaxCoO2 have attracted much interest in the past few years. Crystals with the x˜0.75 composition undergo an order-disorder transition near 340 K, a spin-density-wave transition near 22 K and other subtle transitions at intermediate temperatures. These phase transitions, likely related to a rearrangement of the Na atoms among the available sites, have been mapped out using resonant ultrasound spectroscopy. The results are modeled within the Landau theory for second order phase transitions. [Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the U.S. Dept. of Energy under contract DE-AC05-00OR22725

Measurement of the total hadronic cross section in e sup + e minus annihilation at radical s =29 GeV

Energy Technology Data Exchange (ETDEWEB)

von Zanthier, C.; de Boer, W.; Grindhammer, G.; Hylen, J.; Harral, B.; Hearty, C.; Labarga, L.; Matthews, J.; Schaad, M.; Abrams, G.; Adolphsen, C.E.; Akerlof, C.; Alexander, J.P.; Alvarez, M.; Baden, A.R.; Ballam, J.; Barish, B.C.; Barklow, T.; Barnett, B.A.; Bartelt, J.; Blockus, D.; Bonvicini, G.; Boyarski, A.; Boyer, J.; Brabson, B.; Breakstone, A.; Brom, J.M.; Bulos, F.; Burchat, P.R.; Burke, D.L.; Butler, F.; Calvino, F.; Cence, R.J.; Chapman, J.; Cords, D.; Coupal, D.P.; DeStaebler, H.C.; Dorfan, D.E.; Dorfan, J.M.; Drell, P.S.; Feldman, G.J.; Fernandez, E.; Field, R.C.; Ford, W.T.; Fordham, C.; Frey, R.; Fujino, D.; Gan, K.K.; Gidal, G.; Glanzman, T.; Goldhaber, G.; Green, A.; Grosse-Wiesmann, P.; Haggerty, J.; Hanson, G.; Harr, R.; Harris, F.A.; Hawkes, C.M.; Hayes, K.; Herrup, D.; Heusch, C.A.; Himel, T.; Hoenk, M.; Hutchinson, D.; Innes, W.R.; Jaffre, M.; Jaros, J.A.; Juricic, I.; Kadyk, J.A.; Karlen, D.; Kent, J.; Klein, S.R.; Koska, W.; Kozanecki, W.; Lankford, A.J.; Larse

1991-01-01

A precise measurement of the ratio {ital R} of the total cross section {ital e}{sup +}{ital e{minus}}{r arrow}hadrons to the pointlike cross section {ital e}{sup +}{ital e{minus}}{r arrow}{mu}{sup +}{mu}{sup {minus}} at a center-of-mass energy of 29.0 GeV is presented. The data were taken with the upgraded Mark II detector at the SLAC storage ring PEP. The result is {ital R}=3.92{plus minus}0.05{plus minus}0.09. The luminosity has been determined with three independent luminosity monitors measuring Bhabha scattering at different angular intervals. Recent calculations of higher-order QED radiative corrections are used to estimate the systematic error due to missing higher-order radiative corrections in the Monte Carlo event generators.

Influence of Dy addition on the magnetocaloric effect of La0.67Ca0.33Mn0.9V0.1O3 ceramics

International Nuclear Information System (INIS)

Nisha, P.; Savitha Pillai, S.; Suresh, K.G.; Raama Varma, Manoj

2012-01-01

The influence of partial substitution of La by Dy on the magnetocaloric response of (La 1-x Dy x ) 0.67 Ca 0.33 Mn 0.9 V 0.1 O 3 , where x=0.03, 0.15 and 0.25 is studied. Rietveld refinement of X-ray diffraction pattern using GSAS method shows that the compounds adopt the orthorhombic structure with Pnma space group. The systematic change in lattice parameters and magnetic phase transition indicates the substitution effect of Dy. From the magnetization isotherms at different temperatures, magnetic entropy change close to their respective transition temperatures (T C ) has been evaluated. The maximum value of entropy change near T C is found to be about 4.8 J/kg K at 187.5 K for LCMVDy 0.03 , 2.45 J/kg K at 107.5 K for LCMVDy 0.15 and 2.15 J/kg K at 92.5 K for LCMVDy 0.25 at 4 T. Dy addition produces a reduction in T C and in magnitude of the magnetic entropy change. Even though the entropy change decreases with increasing Dy substitution the refrigerant temperature range, ΔT, is found to be 10 K for LCMVDy 0.03 , 31 K for LCMVDy 0.15 and 35 K for LCMVDy 0.25 compounds [90%] at 4 T. The field dependence of the magnetic entropy change is also analyzed showing the power law dependence, ΔS M ∞H n where n=0.75(2) for LCMVDy 0.03 , n=0.80(4) for LCMVDy 0.15 and n=0.92(8) for LCMVDy 0.25 compounds at their respective transition temperatures. The relative cooling power and its field dependance are also analyzed. - Highlights: → Studied magnetocaloric response of Dy substituted solid state synthesized LCMVO. → Studied the field dependence of the magnetic entropy change (ΔS M ∞H n ). → Studied the field dependence of Relative cooling power (RCP∞H 1+1/δ ). → Considerably large magnetocaloric effect and moderate relative cooling power.

Soluble semiclassical model for a one-dimensional Δl=1, Δm=0, decay

International Nuclear Information System (INIS)

Costa, R.C.T. da; Crestana, S.

1978-01-01

The radiation emitted by a plane of excited two-level atoms, Δl=1, Δm=0 transition, is exactly calculated using a semiclassical model in which the electromagnetic field is treated classically (Maxwell's equations) and the coupling between matter and field is described in the electric dipole approximation. The influence of the plane density in the radiation rate is investigated in both limits of weak and strong coupling (defined in the text). It is shown that, in the second case, we can observe infinitely many solutions of the problem, depending on the initial value of the phase difference appearing in the definition of the excited state. Cases of phase choices leading to enhanced or attenuated emission rates are also discussed [pt

Type-I pseudo-first-order phase transition induced electrocaloric effect in lead-free Bi0.5Na0.5TiO3-0.06BaTiO3 ceramics

Science.gov (United States)

Li, Feng; Chen, Guorui; Liu, Xing; Zhai, Jiwei; Shen, Bo; Li, Shandong; Li, Peng; Yang, Ke; Zeng, Huarong; Yan, Haixue

2017-05-01

In this study, the electrocaloric effect (ECE) of Bi0.5Na0.5TiO3-0.06BaTiO3 (BNT-0.06BT) ceramic has been directly measured using a home-made adiabatic calorimeter. The maximum adiabatic temperature change (ΔT) approaches 0.86 K under an electric field of 5 kV/mm at 110 °C, which provides experimental evidence for optimizing the ECE near the type-I pseudo-first-order phase transition (PFOPT). Most importantly, a considerable ΔT value can be maintained over a wide temperature range well above the temperature of the PFOPT under a high electric field. In addition, ΔT is closely related to the structural transition and electric field strength. This work provides a guideline to investigate the high ECE in BNT-based ferroelectric ceramics for applications in cooling technologies.

Sub-0.1 mu m line fabrication by Focused ion beam and columnar structural Se-Ge resist

CERN Document Server

Lee, H Y; Chung, H B

1998-01-01

As a method to enhance the sensitivity (S) of an inorganic resist for focused-ion-beam (FIB), lithography, sub-0.1 mu m patterning properties of a columnar structural alpha-Se sub 7 sub 5 Ge sub 2 sub 5 resist have been investigated using 30 keV low-energy Ga sup + -FIB exposure and CF sub 4 reactive-ion etching (RIE). development. The Se sub 7 sub 5 Ge sub 2 sub 5 thin films were 60 .deg. and 80 .deg. -obliquely deposited on Si substrate and parts of the films were annealed for several minutes at the glass transition temperature (T sub g =approx 220 .deg. C). Columnar structures with the angles of approximately 40 .deg. and 65 .deg. are observed in 60 .deg. and 80 .deg. -obliquely deposited films, respectively, and they disappear after annealing. Despite the disappearance of the columnar structures, a critical decrease in thickness is not observed. For the FIB exposures with a beam diameter of approx 0.1 mu m and around the threshold dose, the negative-type fine patterns with linewidth of about 0.06 approx 0...

Quenching of spin-flip quadrupole transitions

International Nuclear Information System (INIS)

Castel, B.; Blunden, P.; Okuhara, Y.

1985-01-01

An increasing amount of experimental data indicates that spin-flip quadrupole transitions exhibit quenching effects similar to those reported earlier in (p,n) reactions involving l = 0 and l = 1 transitions. We present here two model calculations suggesting that the E2 spin-flip transitions are more affected than their M1 and M3 counterparts by the tensor and spin-orbit components of the nuclear force and should exhibit the largest quenching. We also review the experimental evidence corroborating our observations

Giant magnetic entropy change in manganese perovskite La{sub 0.67}Sr{sub 0.16}Ca{sub 0.17}MnO{sub 3} near room temperature

Energy Technology Data Exchange (ETDEWEB)

Mohamed, Za, E-mail: zaineb.mohamed24@yahoo.fr [Laboratoire de Physique de la matière condensée et des nanosciences, Faculté des Sciences, 5019, Université de Monastir (Tunisia); Tka, E.; Dhahri, J. [Laboratoire de Physique de la matière condensée et des nanosciences, Faculté des Sciences, 5019, Université de Monastir (Tunisia); Hlil, E.K. [Institut Néel, CNRS et Université Joseph Fourrier, B.P. 166, B.P.W-38042 Grenoble Cedex 9 (France)

2014-12-05

Highlights: • La{sub 0.67}Sr{sub 0.16}Ca{sub 0.17}MnO{sub 3} sample was prepared by solid state method. • La{sub 0.67}Sr{sub 0.16}Ca{sub 0.17}MnO{sub 3} crystallizes in a rhombohedral R3{sup ‾}c structure. • The variation of (M) vs. (T) reveals a (FM) to (PM) phase transition around T{sub C}. • The magnetocaloric effect is studied and the |ΔS{sub M}{sup max}| and RCP are determined. - Abstract: Structural, magnetic and magnetocaloric properties of La{sub 0.67}Sr{sub 0.16}Ca{sub 0.17}MnO{sub 3} perovskite have been studied. A solid state reaction method was used in the preparation phase. X-ray diffraction analysis using Rietveld refinement revealed that this sample crystallizes in the distorted rhombohedral system with R3{sup ‾}c space group. The variation of magnetization (M) vs. temperature (T), under an applied magnetic field of 0.05T, revealed a transition from a ferromagnetic (FM) to paramagnetic (PM) phase at around Curie temperature (T{sub C} = 336 K). Using Arrott plots, it was found that the transition is of a second-order. Isothermal measurements of magnetization allow us, through thermodynamic Maxwell relations, to determine the magnetic entropy change (ΔS{sub M}). A large ΔS{sub M} deduced from isothermal magnetization curves, has been observed in our sample with a peak centered around its respective T{sub C}. The maximum of the magnetic entropy change ΔS{sub M}{sup max} in a magnetic field change of 5T is found to be 5.51 J kg{sup −1} K{sup −1} at 335 K. In addition, the compound showed a large relative cooling power (RCP) value of about 234 J/kg while the maximum refrigerant capacity of 174 J/kg was attained at the applied field of 5T. As a result, the studied sample can be considered as a potential material for magnetic refrigeration.

Low energy E0 transitions in odd-mass nuclei of the neutron deficient 180 < A < 200 region

International Nuclear Information System (INIS)

Zganjar, E.F.; Kortelahti, M.O.; Wood, J.L.; Papanicolopulos, C.D.

1987-01-01

The region of neutron-deficient nuclei near Z = 82 and N = 104 provides the most extensive example of low-energy shape coexistence anywhere on the mass surface. It is shown that E0 and E0 admixed transitions may be used as a fingerprint to identify shape coexistence in odd-mass nuclei. It is also shown that all the known cases of low energy E0 and E0 admixed transitions in odd-mass nuclei occur where equally low-lying O + states occur in neighboring even-even nuclei. A discussion of these and other relevant data as well as suggestions for new studies which may help to clarify and, more importantly, quantify the connection between E0 transitions and shape coexistence are presented. 60 refs., 7 figs., 4 tabs

Symmetry transition via tetravalent impurity and investigations on magnetic properties of Li0.5Fe2.5O4

Science.gov (United States)

Kounsalye, Jitendra S.; Kharat, Prashant B.; Chavan, Apparao R.; Humbe, Ashok V.; Borade, R. M.; Jadhav, K. M.

2018-04-01

The present study, deals with the phase symmetry transformation of lithium ferrite after introducing tetravalent (Ti4+) impurity. The sol-gel auto combustion technique was adopted for the synthesis of nanoparticle samples with generic chemical formula Li0.5Fe2.5O4 and Li0.55Ti0.10Fe2.35O4. The synthesized nanoparticles were characterized by X-ray diffraction (XRD) technique for structural analysis. The XRD patterns show the single phase cubic structure without any impurity phase but the P4332 to Fd-3m transformation was observed after introducing Ti4+ impurity. The Nano size of the synthesized particles was confirmed by crystallite size ( 20nm) calculated using Debye-Scherrer's formula. The Fourier transform infrared spectroscopy (FTIR) studies shows shifting of band frequencies which reflect the structural changes after tetravalent substitutional impurities. The magnetic properties were studied through pulse field hysteresis loop (M-H loop) technique at room temperature, the M-H loops showdecrease in magnetic properties afternonmagnetic Ti4+ ion substitution. This is attributed to transition of inverse spinel structure of lithium ferrite to random spinel structure.

The influence of polytypic structures on the M011-->M101 solid-solid phase transition of n-C36H74: An application of the oblique infrared transmission method

Science.gov (United States)

Kubota, Hideki; Kaneko, Fumitoshi; Kawaguchi, Tatsuya; Kawasaki, Masatsugu

2004-07-01

The molecular displacements on the M011→M101 phase transition of n-hexatriacontane (n-C36H74) have been investigated with an IR microscope designed for the oblique infrared transmission method. It has been clarified that two polytypic structures of the M011 modification, single-layered structure (Mon) and double-layered one (Orth II), both transform to the M101 modification of single-layered structure with their respective mechanisms. On the M011(Mon)→M101 transition, the inclination direction of molecular axis is changed by 90° through an intermediate state in which the molecular chain is set perpendicular to the basal plane of the single crystal. On the other hand, a polymorphic-polytypic composite structural change on the M011(Orth II)→M101 transition is accomplished through two kinds of molecular displacements occurring alternately along the stacking direction of molecular layers.

Phase transition in metastable perovskite Pb(AlNb)0,5O3

International Nuclear Information System (INIS)

Zhabko, T.E.; Olekhnovich, N.M.; Shilin, A.D.

1987-01-01

Dielectric properties of metastable perovskite Pb(AlNb) 0.5 O 3 and X-ray temperature investigations of both perovskite and pyrochlore modifications of the given compound are studied. Samples with the perovskite structure are prepared from the pyrochlorephase at 4-5 GPa pressure and 1170-1270 K. Ferroelectric phase transition is shown to occur in the metastable perovskite phase Pb(AlNb) 0.5 O 3 at 170 K

Low-energy lepton violation from supersymmetric flipped SU(5)

Energy Technology Data Exchange (ETDEWEB)

Brahm, D.E.; Hall, L.J. (Physics Department, University of California, Berkeley, California 94720 (US) Theoretical Physics Group, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, California 94720)

1989-10-01

We construct a supersymmetric flipped SU(5){direct product}U(1) model which violates {ital R} parity and electron number at low energies, through a superpotential term (1/2{ital C}{sup {ital ijk}}L{sub i}L{sub j}E{sub k}{sup c}). Rotation of the electron and Higgs superfields makes this term also responsible for charged-lepton masses. The model employs a missing-partners mechanism for the Higgs fields and a seesaw mechanism for the neutrinos. It correctly predicts the approximate electron mass and several mass relations, as well as numerical values for the grand unification scale and the {ital C}{sup {ital ijk}} coefficients. The electron-neutrino Majorana mass is close to experimental limits, and provides constraints. Interesting {ital Z}{sup 0} decays are predicted: e.g., {ital Z}{sup 0}{r arrow}e{sup {minus}}{mu}{sup +}e{sup +}{mu}{sup {minus}} with invariant-mass peaks in the ({ital e},{mu}) channels.

Development of direct reading dosimeters for the dose 0-3 mSv and 0-5 mSv ranges for personnel monitoring

International Nuclear Information System (INIS)

Gaikwad, P.V.; Shirkar, Y.B.; Patil, A.S.; Madgaonkar, P.P.; Kale, K.L.; Guhagarkar, H.V.; Gandhi, D.P.; Gupta, S.K.; Kothiyal, G.P.; Sahni, V.C.

1998-01-01

Direct reading dosimeters (DRDs) are widely used to measure cumulative dose received by personnel working at nuclear reactor sites or in other environment having x- and gamma rays. A DRD operates on the principle of gold leaf electroscope, and is a small, rugged, hermetically sealed, self reading type device easily carried by an individual in his pocket. The development of dosimeters suitable for the dose ranges 0-3 mSv and 0-5 mSv is reported

First observation of the strongly forbidden transition {sup 1}S{sub 0} - {sup 3}P{sub 0} in Strontium, for an atomic clock with trapped atoms; Premiere observation de la transition fortement interdite {sup 1}S{sub 0} - {sup 3}P{sub 0} du strontium, pour une horloge optique a atomes pieges

Energy Technology Data Exchange (ETDEWEB)

Courtillot, I

2003-11-01

This thesis reports the first results towards the realization of an optical clock using trapped strontium atoms. This set up would combine advantages of the different approaches commonly used to develop an atomic frequency standard. The first part describes the cold atoms source which is implemented. A magneto-optical trap operating on the {sup 1}S{sub 0}-{sup 1}P{sub 1} transition at 461 nm is loaded from an atomic beam decelerated by a Zeeman slower. The 461 nm laser is obtained by sum-frequency mixing in a potassium titanyl phosphate (KTP) crystal. The second part is devoted to the different stages developed to achieve the direct excitation of the {sup 1}S{sub 0}-{sup 3}P{sub 0} clock transition in {sup 87}Sr. This line has a theoretical natural width of 10{sup -3} Hz. Before this detection, we obtained an estimate of the resonance frequency by measuring absolute frequencies of several allowed optical transitions. (author)

Tetragonal-to-Tetragonal Phase Transition in Lead-Free (KxNa1−xNbO3 (x = 0.11 and 0.17 Crystals

Directory of Open Access Journals (Sweden)

Dabin Lin

2014-06-01

Full Text Available Lead free piezoelectric crystals of (KxNa1−xNbO3 (x = 0.11 and 0.17 have been grown by the modified Bridgman method. The structure and chemical composition of the obtained crystals were determined by X-ray diffraction (XRD and electron probe microanalysis (EPMA. The domain structure evolution with increasing temperature for (KxNa1−xNbO3 (x = 0.11 and 0.17 crystals was observed using polarized light microscopy (PLM, where distinguished changes of the domain structures were found to occur at 400 °C and 412 °C respectively, corresponding to the tetragonal to tetragonal phase transition temperatures. Dielectric measurements performed on (K0.11Na0.89NbO3 crystals exhibited tetragonal to tetragonal and tetragonal to cubic phase transitions temperatures at 405 °C and 496 °C, respectively.

MASCARA-2 b. A hot Jupiter transiting the mV = 7.6 A-star HD 185603

Science.gov (United States)

Talens, G. J. J.; Justesen, A. B.; Albrecht, S.; McCormac, J.; Van Eylen, V.; Otten, G. P. P. L.; Murgas, F.; Palle, E.; Pollacco, D.; Stuik, R.; Spronck, J. F. P.; Lesage, A.-L.; Grundahl, F.; Fredslund Andersen, M.; Antoci, V.; Snellen, I. A. G.

2018-04-01

In this paper we present MASCARA-2 b, a hot Jupiter transiting the mV = 7.6 A2 star HD 185603. Since early 2015, MASCARA has taken more than 1.6 million flux measurements of the star, corresponding to a total of almost 3000 h of observations, revealing a periodic dimming in the flux with a depth of 1.3%. Photometric follow-up observations were performed with the NITES and IAC80 telescopes and spectroscopic measurements were obtained with the Hertzsprung SONG telescope. We find MASCARA-2 b orbits HD 185603 with a period of 3.4741119-0.000006+0.000005 at a distance of 0.057 ± 0.006 au, has a radius of 1.83 ± 0.07 RJ and place a 99% upper limit on the mass of http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/612/A57

0.20-m (8-in.) primary burner development report

International Nuclear Information System (INIS)

Stula, R.T.; Young, D.T.; Rode, J.S.

1977-12-01

High-Temperature Gas-Cooled Reactors (HTGRs) utilize graphite-base fuels. Fluidized-bed burners are being employed successfully in the experimental reprocessing of these fuels. The primary fluidized-bed burner is a unit operation in the reprocessing flowsheet in which the graphite moderator is removed. A detailed description of the development status of the 0.20-m (8-in.) diameter primary fluidized-bed burner as of July 1, 1977 is presented. Experimental work to date performed in 0.10; 0.20; and 0.40-m (4, 8, and 16 in.) diameter primary burners has demonstrated the feasibility of the primary burning process and, at the same time, has defined more clearly the areas in which additional experimental work is required. The design and recent operating history of the 0.20-m-diameter burner are discussed, with emphasis placed upon the evolution of the current design and operating philosophy

Phase transformations in titanium oxycarbide TiC0.545O0.08

International Nuclear Information System (INIS)

Tashmetov, M.Yu.; Em, V.T.; Savenko, B.N.; Batdemberel, G.

2003-01-01

Phase transformations in titanium oxycarbide TiC 0.545 O 0.08 have been studied by the methods of neutron diffraction and X-ray structure analysis. It was established that the ordered cubic structure δ ' (sp. gr. Fd3m) of the oxycarbide sample is the low-temperature ordered phase existing up to 990 K. The order-disorder phase transition (990 K) results in the formation of an ordered trigonal structure (sp. gr. R3-barm or P3 1 21). The α-Ti-phase is separated at the temperature 1020 K. The order-disorder phase transition was found at T = 1040 K

Reconsideration of the m=0 Z-pinch stability

International Nuclear Information System (INIS)

Scheffel, J.; Coppins, M.

1993-01-01

Possible paths for obtaining linear stability against the m=0 mode in the Z-pinch are studied. Using a generalized energy principle, the necessary and sufficient Chew-Goldberger-Low (CGL) m=0 stability criterion is derived. This criterion is less restrictive than that of ideal MHD, although it also requires the boundary plasma pressure to be finite. It is shown that the edge pressure cannot be stably upheld by a surface current. By instead assuming a finite pressure external gas, it is found that an edge pressure to on-axis pressure ratio of 0.5 is required for stability of a constant current density profile. A parabolic current density profile lowers the limit to the value 0.17. The growth rates are shown to be monotonically decreasing as a function of the external gas pressure. Detailed derivations of the boundary conditions are also given. The results aid in clarifying the experimental stability of four major Z-pinch experiments. Finite Larmor radius stabilization is hence required to maintain stability in future fibre pinch experiments in vacuum, implying line densities less than 10 19 m -1 . (author). 28 refs, 10 figs

Spin transitions in La{sub 0.7} Ba{sub 0.3}CoO{sub 3} thin films revealed by combining Raman spectroscopy and X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Othmen, Zied; Oueslati, Meherzi [Unité Nanomatériaux et Photonique, Faculty of Sciences of Tunis, Tunis El-Manar University, 2092 Tunis (Tunisia); Copie, Olivier; Gemeiner, Pascale; Dkhil, Brahim [Laboratoire Structures, Propriétés et Modélisation des Solides, Centrale Supélec, CNRS-UMR 8580, Université Paris-Saclay (France); Daoudi, Kais [Unité Nanomatériaux et Photonique, Faculty of Sciences of Tunis, Tunis El-Manar University, 2092 Tunis (Tunisia); Department of Applied Physics and Astronomy, College of Sciences, University of Sharjah, P.O. Box 27272, Sharjah (United Arab Emirates); Boudard, Michel [Univ. Grenoble Alpes, LMGP, F-38000 Grenoble (France)

2016-07-07

In cobaltite, the spin states transitions of Co{sup 3+/4+} ions govern the magnetic and electronic conduction properties. These transitions are strain-sensitive and can be varied using external parameters, including temperature, hydrostatic pressure, or chemical stresses through ionic substitutions. In this work, using temperature dependent Raman spectroscopy and X-ray diffraction, the epitaxial strain effects on both structural and vibrational properties of La{sub 0.7} Ba{sub 0.3} CoO{sub 3} (LBCO) cobaltite thin films are investigated. All Raman active phonon modes as well as the structure are found to be strongly affected. Both Raman modes and lattice parameter evolutions show temperature changes correlated with magnetic and electronic transitions properties. Combining Raman spectroscopy and X-ray diffraction appears as a powerful approach to probe the spin transition in thin film cobaltite. Our results provide insight into strong spin-charge-phonon coupling in LBCO thin film. This coupling manifests as vibrational transition with temperature in the Raman spectra near the ferromagnetic spin ordered transition at 220 K.

Higroscopicidade das sementes de pimenta (<italic>Capsicum chinenseitalic> L.)

OpenAIRE

Silva, Hellismar W. da; Costa, Lílian M.; Resende, Osvaldo; Oliveira, Daniel E. C. de; Soares, Renato S.; Vale, Luís S. R.

2015-01-01

RESUMOA higroscopicidade de sementes fornece informações essenciais para otimização de processos de secagem, armazenamento e desenvolvimento de embalagens. O objetivo neste trabalho foi determinar as isotermas de dessorção das sementes de pimenta (Capsicum chinense L.), variedade Cabacinha, para diferentes condições de temperatura e atividade de água utilizando-se o método estático indireto, sendo a atividade de água (aw) determinada por meio do equipamento Hygropalm Model Aw1. Aos dados expe...

The hidden treasure in your data: phasing with unexpected weak anomalous scatterers from routine data sets

Energy Technology Data Exchange (ETDEWEB)

Hegde, Raghurama P.; Fedorov, Alexander A.; Sauder, J. Michael; Burley, Stephen K.; Almo, Steven C.; Ramagopal, Udupi A.

2017-03-22

Single-wavelength anomalous dispersion (SAD) utilizing anomalous signal from native S atoms, or other atoms with<italic>Z>≤ 20, generally requires highly redundant data collected using relatively long-wavelength X-rays. Here, the results from two proteins are presented where the anomalous signal from serendipitously acquired surface-bound Ca atoms with an anomalous data multiplicity of around 10 was utilized to drive<italic>de novoitalic>structure determination. In both cases, the Ca atoms were acquired from the crystallization solution, and the data-collection strategy was not optimized to exploit the anomalous signal from these scatterers. The X-ray data were collected at 0.98 Å wavelength in one case and at 1.74 Å in the other (the wavelength was optimized for sulfur, but the anomalous signal from calcium was exploited for structure solution). Similarly, using a test case, it is shown that data collected at ~1.0 Å wavelength, where the<italic>f>'' value for sulfur is 0.28 e, are sufficient for structure determination using intrinsic S atoms from a strongly diffracting crystal. Interestingly, it was also observed that<italic>SHELXD>was capable of generating a substructure solution from high-exposure data with a completeness of 70% for low-resolution reflections extending to 3.5 Å resolution with relatively low anomalous multiplicity. Considering the fact that many crystallization conditions contain anomalous scatterers such as Cl, Ca, Mn<italic>etc.>, checking for the presence of fortuitous anomalous signal in data from well diffracting crystals could prove useful in either determining the structure<italic>de novoitalic>or in accurately assigning surface-bound atoms.

arXiv Measurement of the $\\pi^0$ electromagnetic transition form factor slope

CERN Document Server

Lazzeroni, C.; Romano, A.; Blazek, T.; Koval, M.; Ceccucci, A.; Danielsson, H.; Falaleev, V.; Gatignon, L.; Goy Lopez, S.; Hallgren, B.; Maier, A.; Peters, A.; Piccini, M.; Riedler, P.; Frabetti, P.L.; Gersabeck, E.; Kekelidze, V.; Madigozhin, D.; Misheva, M.; Molokanova, N.; Movchan, S.; Potrebenikov, Yu.; Shkarovskiy, S.; Zinchenko, A.; Rubin, P.; Baldini, W.; Cotta Ramusino, A.; Dalpiaz, P.; Fiorini, M.; Gianoli, A.; Norton, A.; Petrucci, F.; Savrié, M.; Wahl, H.; Bizzeti, A.; Bucci, F.; Iacopini, E.; Lenti, M.; Veltri, M.; Antonelli, A.; Moulson, M.; Raggi, M.; Spadaro, T.; Eppard, K.; Hita-Hochgesand, M.; Kleinknecht, K.; Renk, B.; Wanke, R.; Winhart, A.; Winston, R.; Bolotov, V.; Duk, V.; Gushchin, E.; Ambrosino, F.; Di Filippo, D.; Massarotti, P.; Napolitano, M.; Palladino, V.; Saracino, G.; Anzivino, G.; Imbergamo, E.; Piandani, R.; Sergi, A.; Cenci, P.; Pepe, M.; Costantini, F.; Doble, N.; Giudici, S.; Pierazzini, G.; Sozzi, M.; Venditti, S.; Balev, S.; Collazuol, G.; DiLella, L.; Gallorini, S.; Goudzovski, E.; Lamanna, G.; Mannelli, I.; Ruggiero, G.; Cerri, C.; Fantechi, R.; Kholodenko, S.; Kurshetsov, V.; Obraztsov, V.; Semenov, V.; Yushchenko, O.; D'Agostini, G.; Leonardi, E.; Serra, M.; Valente, P.; Fucci, A.; Salamon, A.; Bloch-Devaux, B.; Peyaud, B.; Engelfried, J.; Coward, D.; Kozhuharov, V.; Litov, L.; Arcidiacono, R.; Bifani, S.; Biino, C.; Dellacasa, G.; Marchetto, F.; Numao, T.; Retière, F.

2017-05-10

The NA62 experiment collected a large sample of charged kaon decays in 2007 with a highly efficient trigger for decays into electrons. A measurement of the $\\pi^{0}$ electromagnetic transition form factor slope parameter from $1.11\\times10^{6}$ fully reconstructed $K^\\pm \\to \\pi^\\pm \\pi^0_D, \\; \\pi^0_D \\to e^+ e^- \\, \\gamma$ events is reported. The measured value $a = \\left(3.68 \\pm 0.57\\right)\\times 10^{-2}$ is in good agreement with theoretical expectations and previous measurements, and represents the most precise experimental determination of the slope in the time-like momentum transfer region.

Study of photo-stimulated luminescence in Ba0.95M0.05FBr:Eu2+ (M = Sr, Ca) powder

International Nuclear Information System (INIS)

Zhou Yingxue; Wang Dongsheng; Zhang Xinyi

2001-01-01

The luminescence centered at about 390 nm due to 4f 6 5d→4f 7 transition of Eu 2+ can be observed without X-ray or UV-light pre-irradiation for BaFBr:Eu 2+ , Ba 0.95 Sr 0.05 FBr:Eu 2+ and Ba 0.95 Ca 0.05 FBr:Eu 2+ powder samples which can be excited by light with wave length longer than 400 nm. It could be attributed to F centers which are formed in the preparation of samples. There are two broad bands in the photo-stimulated spectra. One peaked at 535 nm results from the excitation of electrons at F(F - ) center, and the other at 708 nm might be originated from the electron excitation of F(Br - ) center or F(Br - ) accumulators. If the Ba 2+ (ion's radius equals to 0.135 nm) in the samples were replaced by about 50% mol. of Sr 2+ (ion's radius equals to 0.113 nm) or Ca 2+ (ion's radius equals to 0.099 nm), the intensities of 535 nm and 708 nm bands decrease with the decreasing of ion radius. On the other hand, the shoulders at 580 nm and 650 nm or 575 nm and 645 nm can appear. In absorption spectra of 50-400 nm range, one can observe the red-shift of 79 nm, 83 nm peaks and new absorption peaks. It means that the new color centers: F(F - , Sr 2+ ), F(br - , Sr 2+ ) or F(F - , Ca 2+ ), F(br - , Ca 2+ ) are formed, when Ba 2+ were replaced with Sr 2+ or Ca 2+ in samples. It corresponds to the shoulders in photo-stimulated spectra

Anion Redox Chemistry in the Cobalt Free 3d Transition Metal Oxide Intercalation Electrode Li[Li0.2Ni0.2Mn0.6]O2.

Science.gov (United States)

Luo, Kun; Roberts, Matthew R; Guerrini, Niccoló; Tapia-Ruiz, Nuria; Hao, Rong; Massel, Felix; Pickup, David M; Ramos, Silvia; Liu, Yi-Sheng; Guo, Jinghua; Chadwick, Alan V; Duda, Laurent C; Bruce, Peter G

2016-09-07

Conventional intercalation cathodes for lithium batteries store charge in redox reactions associated with the transition metal cations, e.g., Mn(3+/4+) in LiMn2O4, and this limits the energy storage of Li-ion batteries. Compounds such as Li[Li0.2Ni0.2Mn0.6]O2 exhibit a capacity to store charge in excess of the transition metal redox reactions. The additional capacity occurs at and above 4.5 V versus Li(+)/Li. The capacity at 4.5 V is dominated by oxidation of the O(2-) anions accounting for ∼0.43 e(-)/formula unit, with an additional 0.06 e(-)/formula unit being associated with O loss from the lattice. In contrast, the capacity above 4.5 V is mainly O loss, ∼0.08 e(-)/formula. The O redox reaction involves the formation of localized hole states on O during charge, which are located on O coordinated by (Mn(4+)/Li(+)). The results have been obtained by combining operando electrochemical mass spec on (18)O labeled Li[Li0.2Ni0.2Mn0.6]O2 with XANES, soft X-ray spectroscopy, resonant inelastic X-ray spectroscopy, and Raman spectroscopy. Finally the general features of O redox are described with discussion about the role of comparatively ionic (less covalent) 3d metal-oxygen interaction on anion redox in lithium rich cathode materials.

Crystal growth of Sm0.3Tb0.7FeO3 and spin reorientation transition in Sm1−xTbxFeO3 orthoferrite

International Nuclear Information System (INIS)

Wu, Anhua; Wang, Bo; Zhao, Xiangyang; Xie, Tao; Man, Peiwen; Su, Liangbi; Kalashnikova, A.M.; Pisarev, R.V.

2017-01-01

In this work, Sm 0.3 Tb 0.7 FeO 3 single crystal was successfully grown by optical floating zone method. Sm 0.3 Tb 0.7 FeO 3 samples with a-, b-, and c-orientation were manufactured by means of Laue photograph. Magnetic properties of Sm 0.3 Tb 0.7 FeO 3 single crystals are studied over a wide temperature range from 2 to 400 K. Spin reorientation transition from Γ 2 to Γ 4 are observed by means of the temperature dependence of magnetization It indicated the reorientation transition temperature of Sm 1−x Tb x FeO 3 single crystals is lowered with the contents of Tb contents rising based on this work and our previous works, thus the spin reorientation transition temperature can be adjusted through changing the compound in orthoferrites materials, which means that we can get orthoferrites single crystals with high magnetism property in various temperature through material design. - Highlights: • Sm 0.3 Tb 0.7 FeO 3 single crystals with various compounds were successfully grown by optical floating zone method. • The relation between SRT temperature and composition in Sm 1−x Tb x FeO 3 orthoferrite was indicated. • The spin reorientation transition temperature of Sm 1−x Tb x FeO 3 single crystals can be adjusted through changing the compound in orthoferrites materials.

Hot Jupiters around M dwarfs

Directory of Open Access Journals (Sweden)

Murgas F.

2013-04-01

Full Text Available The WFCAM Transit Survey (WTS is a near-infrared transit survey running on the United Kingdom Infrared Telescope (UKIRT. We conduct Monte Carlo transit injection and detection simulations for short period (<10 day Jupiter-sized planets to characterize the sensitivity of the survey. We investigate the recovery rate as a function of period and magnitude in 2 hypothetical star-planet cases: M0–2 + hot Jupiter, M2–4 + hot Jupiter. We find that the WTS lightcurves are very sensitive to the presence of Jupiter-sized short-period transiting planets around M dwarfs. The non-detection of a hot-Jupiter around an M dwarf by the WFCAM Transit Survey allows us to place a firm upper limit of 1.9 per cent (at 95 per cent confidence on the planet occurrence rate.

Topic 2.0: Tropical cyclone formation and extratropical transition

OpenAIRE

Harr, Patrick A.

2010-01-01

Approved for public release; distribution is unlimited In this section, progress since ITWC-VI on research, observations and forecasting of tropical cyclone formation and extratropical transition is summarized. While tropical cyclone formation and extratropical transition are stages at opposite ends of the tropical cyclone lifecycle, significant lack of understanding remains in relation to processes associated with each stage. Formation and extratropical transition involve interactions a...

Laser-radiation therapy for T2N0M0 laryngeal-glottic cancer

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Gen; Hayabuchi, Naofumi; Toda, Yukihiro; Suefuji, Hiroaki; Ogo, Etuyo; Nakajima, Tadashi [Kurume Univ., Fukuoka (Japan). School of Medicine

2002-03-01

The purpose of this study was to evaluate the laser-radiation combined therapy for T2N0M0 laryngeal-glottic cancer in order to preserve the larynx. The subjects consisted of 52 patients with T2N0M0 laryngeal-glottic cancer treated with laser-radiation combined therapy between 1980 and 1999. Patients ranged in age from 40-88 years, with a median of 70 years, and included 51 men and one woman. During this period, treatment was administered with different radiation devices ({sup 60}Co or 4 MV-X ray), and 40-72 Gy (median, 60Gy) of radiation therapy were administered. Tumor and treatment characteristics were correlated with local control at a median follow-up of 61 months (range 12-210 months). Concurrent chemotherapy was administered to 32 patients; 29 were treated with 5-FU and vitamin A (FAR), and 3 were treated with low-dose CDDP. Post treatment vocal function was examined in 37 patients. The voice was evaluated in terms of four parameters: maximum phonation time (MPT), mean air flow rate during phonation over a comfortable duration (MFR), fundamental frequency range of phonation (F0 range), and sound pressure level range of phonation (SPL range). The five-year cause-specific-survival rate was 98.0%, and the local control rate was 91.8%. Three of 4 patients who had locally relapsed were administered total laryngectomy as salvage therapy. One patient was administered the tracheostomy for late complication. The actuarial laryngeal preservation rate was 92.3%. We did not find any significant relationship between local relapse and extent of disease, subglottic extension, or anterior commissure involvement. Concurrent chemotherapy was not a significant prognostic factor. Laser debulking followed by radiation therapy did not change the voice significantly except the F0 range. We conclude that the laser-radiation combined therapy for T2N0M0 laryngeal-glottic cancer was effective therapy for not only preservation of the voice but also for vocal function. (author)

Laser-radiation therapy for T2N0M0 laryngeal-glottic cancer

International Nuclear Information System (INIS)

Suzuki, Gen; Hayabuchi, Naofumi; Toda, Yukihiro; Suefuji, Hiroaki; Ogo, Etuyo; Nakajima, Tadashi

2002-01-01

The purpose of this study was to evaluate the laser-radiation combined therapy for T2N0M0 laryngeal-glottic cancer in order to preserve the larynx. The subjects consisted of 52 patients with T2N0M0 laryngeal-glottic cancer treated with laser-radiation combined therapy between 1980 and 1999. Patients ranged in age from 40-88 years, with a median of 70 years, and included 51 men and one woman. During this period, treatment was administered with different radiation devices ( 60 Co or 4 MV-X ray), and 40-72 Gy (median, 60Gy) of radiation therapy were administered. Tumor and treatment characteristics were correlated with local control at a median follow-up of 61 months (range 12-210 months). Concurrent chemotherapy was administered to 32 patients; 29 were treated with 5-FU and vitamin A (FAR), and 3 were treated with low-dose CDDP. Post treatment vocal function was examined in 37 patients. The voice was evaluated in terms of four parameters: maximum phonation time (MPT), mean air flow rate during phonation over a comfortable duration (MFR), fundamental frequency range of phonation (F0 range), and sound pressure level range of phonation (SPL range). The five-year cause-specific-survival rate was 98.0%, and the local control rate was 91.8%. Three of 4 patients who had locally relapsed were administered total laryngectomy as salvage therapy. One patient was administered the tracheostomy for late complication. The actuarial laryngeal preservation rate was 92.3%. We did not find any significant relationship between local relapse and extent of disease, subglottic extension, or anterior commissure involvement. Concurrent chemotherapy was not a significant prognostic factor. Laser debulking followed by radiation therapy did not change the voice significantly except the F0 range. We conclude that the laser-radiation combined therapy for T2N0M0 laryngeal-glottic cancer was effective therapy for not only preservation of the voice but also for vocal function. (author)

Ge(001)-(<2 1>, <0 3>)-Pb(<2 1>, <0 6>)↔Pb: Low-temperature two-dimensional phase transition

DEFF Research Database (Denmark)

Bunk, Oliver; Nielsen, Martin Meedom; Zeysing, J.H.

2001-01-01

The Ge(001)-((2 1)(0 3))-Pb surface reconstruction with a lead coverage of 5/3 monolayer is on the borderline between the low-coverage covalently-bonded and high-coverage metallic lead overlayers. This gives rise to an unusual low-temperature phase transition with concomitant changes in the bonding...

Coping with uncertainty: T1a,bN0M0 HER2-positive breast cancer, do we have a treatment threshold?

LENUS (Irish Health Repository)

Kelly, C M

2012-02-01

BACKGROUND: Recent retrospective studies have suggested that patients with T1a,bN0M0 human epidermal growth factor receptor 2 (HER2)-positive breast cancer are at a higher risk for recurrence and might benefit from adjuvant trastuzumab. The absolute benefits associated with treating this subgroup are uncertain. Design: We reviewed recent studies examining the prognostic value of HER2 in patients with node-negative T1a,b HER2-positive breast cancer. We calculated the number needed to treat (NNT) using baseline risk estimates for untreated T1a,bN0M0 breast cancer and the number needed to harm (NNH) using the incidence of cardiac events in each of the adjuvant trastuzumab clinical trials. RESULTS: Several studies were identified, each with limitations inherent to retrospective database analyses: small cohort sizes, lack of systematic HER2 testing in older specimens, variations in the use of adjuvant therapy and definitions of study end points, and lack of information relating to comorbidities. The 5-year disease-free survival in the pre-trastuzumab era ranged from 77% to 95%. Comparisons between small HER2 -positive and small HER2 -negative cancers showed numerically worse outcome for the HER2-positive cohort in some but not all studies. In many instances, the NNH was larger (26-250) than the NNT (13-35); however, in a subset of patients, the NNH was lower (6) than the NNT (13-35). CONCLUSIONS: Better prediction tools to estimate more precisely the risk for death due to comorbid illness versus breast cancer are needed. In some patients, the risks of therapy could outweigh the benefits. Treatment selection for T1a,bN0 HER2-positive cancers remains in the transition area between evidence- and subjective judgment-based medicine.

In-field X-ray and neutron diffraction studies of re-entrant charge-ordering and field induced metastability in La0.175Pr0.45Ca0.375MnO3-δ

Science.gov (United States)

Sharma, Shivani; Shahee, Aga; Yadav, Poonam; da Silva, Ivan; Lalla, N. P.

2017-11-01

Low-temperature high-magnetic field (2 K, 8 T) (LTHM) powder X-ray diffraction (XRD) and time of flight powder neutron diffraction (NPD), low-temperature transmission electron microscopic (TEM), and resistivity and magnetization measurements have been carried out to investigate the re-entrant charge ordering (CO), field induced structural phase transitions, and metastability in phase-separated La0.175Pr0.45Ca0.375MnO3-δ (LPCMO). Low-temperature TEM and XRD studies reveal that on cooling under zero-field, paramagnetic Pnma phase transforms to P21/m CO antiferromagnetic (AFM) insulating phase below ˜233 K. Unlike reported literature, no structural signature of CO AFM P21/m to ferromagnetic (FM) Pnma phase-transition during cooling down to 2 K under zero-field was observed. However, the CO phase was found to undergo a re-entrant transition at ˜40 K. Neutron diffraction studies revealed a pseudo CE type spin arrangement of the observed CO phase. The low-temperature resistance, while cooled under zero-field, shows insulator to metal like transition below ˜105 K with minima at ˜25 K. On application of field, the CO P21/m phase was found to undergo field-induced transition to FM Pnma phase, which shows irreversibility on field removal below ˜40 K. Zero-field warming XRD and NPD studies reveal that field-induced FM Pnma phase is a metastable phase, which arise due to the arrest of kinetics of the first-order phase transition of FM Pnma to CO-AFM P21/m phase, below 40 K. Thus, a strong magneto-structural coupling is observed for this system. A field-temperature (H-T) phase-diagram has been constructed based on the LTHM-XRD, which matches very nicely with the reported H-T phase-diagram constructed based on magnetic measurements. Due to the occurrence of gradual growth of the re-entrant CO phase and the absence of a clear structural signature of phase-separation of CO-AFM P21/m and FM Pnma phases, the H-T minima in the phase-diagram of the present LPCMO sample has been

Infrared reflectivity investigation of the phase transition sequence in Pr{sub 0.5}Ca{sub 0.5}MnO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, J.L., E-mail: jlr@fisica.uminho.pt [Centro and Departamento de Física da Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Vieira, L.G. [Centro and Departamento de Física da Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Gomes, I.T. [Centro and Departamento de Física da Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); IFIMUP and IN - Institute of Nanoscience and Nanotechnology, Departamento de Física e Astronomia da Faculdade de Ciências da Universidade do Porto, R. do Campo Alegre, 687, 4769-007 Porto (Portugal); Araújo, J.P. [IFIMUP and IN - Institute of Nanoscience and Nanotechnology, Departamento de Física e Astronomia da Faculdade de Ciências da Universidade do Porto, R. do Campo Alegre, 687, 4769-007 Porto (Portugal); Tavares, P. [Centro de Química – Vila Real, Universidade de Trás-os-Montes e Alto Douro, 5001-801 Vila Real (Portugal); Almeida, B.G. [Centro and Departamento de Física da Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

2016-06-15

This work reports an infrared reflectivity study of the phase transition sequence observed in Pr{sub 0.5}Ca{sub 0.5}MnO{sub 3.} The need to measure over an extended spectral range in order to properly take into account the effects of the high frequency polaronic absorption is circumvented by adopting a simple approximate method, based on the asymmetry present in the Kramers Kronig inversion of the phonon spectrum. The temperature dependence of the phonon optical conductivity is then investigated by monitoring the behavior of three relevant spectral moments of the optical conductivity. This combined methodology allows us to disclose subtle effects of the orbital, charge and magnetic orders on the lattice dynamics of the compound. The characteristic transition temperatures inferred from the spectroscopic measurements are compared and correlated with those obtained from the temperature dependence of the induced magnetization and electrical resistivity. - Highlights: • Study of the effects of orbital, charge and spin orders on the lattice dynamics. • Phonon optical conductivity spectral moments are used to monitor phase transitions. • Precursor effects of the AFM order are detected by infrared spectroscopy.

Synthesis and characterization of La0.6Sr0.4Fe0.8Cu0.2O3−δ oxide as cathode for Intermediate Temperature Solid Oxide Fuel Cells

International Nuclear Information System (INIS)

Vázquez, Santiago; Davyt, Sebastián; Basbus, Juan F.; Soldati, Analía L.; Amaya, Alejandro; Serquis, Adriana; Faccio, Ricardo; Suescun, Leopoldo

2015-01-01

Nanocrystalline La 0.6 Sr 0.4 Fe 0.8 Cu 0.2 O 3−δ (LSFCu) material was synthetized by combustion method using EDTA as fuel/chelating agent and NH 4 NO 3 as combustion promoter. Structural characterization using thermodiffraction data allowed to determine a reversible phase transition at 425 °C from a low temperature R-3c phase to a high temperature Pm-3m phase and to calculate the thermal expansion coefficient (TEC) of both phases. Important characteristics for cathode application as electronic conductivity and chemical compatibility with Ce 0.9 Gd 0.1 O 2−δ (CGO) electrolyte were evaluated. LSFCu presented a p-type conductor behavior with maximum conductivity of 135 S cm −1 at 275 °C and showed a good stability with CGO electrolyte at high temperatures. This work confirmed that as prepared LSFCu has excellent microstructural characteristics and an electrical conductivity between 100 and 60 S cm −1 in the 500–700 °C range which is sufficiently high to work as intermediate temperature Solid Oxide Fuel Cells (IT-SOFCs) cathode. However a change in the thermal expansion coefficient consistent with a small oxygen loss process may affect the electrode-electrolyte interface during fabrication and operation of a SOFC. - Graphical abstract: Nanocrystalline La 0.6 Sr 0.4 Fe 0.8 Cu 0.2 O 3−δ was prepared by gel combustion and characterized by X-ray thermodiffraction and its conductivity was determined. The phase shows a reversible rhombohedral to cubic structural phase transition at 425 °C and a semiconductor to metallic phase transition at 275 °C. - Highlights: • LSFCu was prepared by gel combustion route using EDTA and NH 4 NO 3 . • LSFCu shows a reversible phase transition at 425 °C from R-3c to Pm-3m phase. • The sample has a maximum conductivity value of 135 S cm −1 at 275 °C. • LSFCu shows a good chemical compatibility with CGO at 900 °C

Self-consistent theory of normal-to-superconducting transition

International Nuclear Information System (INIS)

Radzihovsky, L.; Chicago Univ., IL

1995-01-01

I study the normal-to-superconducting (NS) transition within the Ginzburg-Landau (GL) model, taking into account the fluctuations in the m-component complex order parameter ψ α and the vector potential A in the arbitrary dimension d, for any m. I find that the transition is of second order and that the previous conclusion of the fluctuation-driven first-order transition is a possible artifact of the breakdown of the ε-expansion and the inaccuracy of the 1/m-expansion for physical values ε = 1, m 1. I compute the anomalous η(d, m) exponent at the NS transition, and find η(3, 1) ∼ -0.38. In the m → ∞ limit, η(d, m) becomes exact and agrees with the 1/m-expansion. Near d = 4 the theory is also in good agreement with the perturbative ε-expansion results for m > 183 and provides a sensible interpolation formula for arbitrary d and m. (orig.)

Determination of regional esophageal transit in children by means of krypton-8 1m

International Nuclear Information System (INIS)

Piepsz, A.; Ham, H.R.; Georges, B.; Delaet, M.H.; Cadranel, S.

1984-01-01

Radionuclide methods using Tc-99m have been developed in the last few years for the assessment of the esophageal transit. The method is physiologic, easy to perform and giving thus interesting informations concerning the severity of the disease as well as the effect of the applied treatment. In children, however, one is limited by radiation protection considerations, and the results are often of poor quality due to the low count rate. Furthermore, the risk of external contamination and the impossibility of repeating the test constitute significant disadvantages, particularly in young children. These problems are completely avoided by using Krypton-8lm diluted in a glucose solution. For each swallowing about 8 mCi of Kr-8 lm are administered. Sixty one-second frames are recorded and several parameters of regional transit can be extracted in a few minutes, using time activity curves and parametric images. The test is very sensitive in detecting minor regional transit alterations. The reproducibility of the test is good and phenomenons like intercurrent gastro-esophageal reflux or asynergic peristaltic waves can easily be detected. The test has been applied to 52 children, aged 1 week to 19 years, and provided helpful information concerning the localization and the importance of transit abnormalities in caustic and peptic esophagitis, postoperative cases (atresia or antireflux plasty) and in patients with neuromuscular disorders

Semiclassical analysis of jm → j'm' transitions in rotationally inelastic collisions in cell experiments

Science.gov (United States)

Price, T. J.; Hickman, A. P.

2018-02-01

Recent quantum calculations of rotationally inelastic collisions of NaK (A1Σ+) with He or Ar in a cell experiment are analyzed using semiclassical approximations valid for large quantum numbers. The results suggest a physical interpretation of jm → j'm' transitions based on the vector model and lead to expressions that explicitly involve the initial and final polar angles of the angular momentum of the target molecule. The relation between the polar angle θ and the azimuthal quantum number m links the semiclassical results for the change in polar angle (θ → θ') to quantum results for an m → m' transition. Analytic formulas are derived that relate the location and width of peaks in the final polar angle distribution (PAD) to the K-dependence of the coefficients dK(j, j'), which are proportional to tensor cross sections σK(j → j'). Several special cases are treated that lead to final PADs that are approximately Lorentzian or sinc functions centered at θ' = θ. Another interesting case, "angular momentum reversal," was observed in the calculations for He. This phenomenon, which involves a reversal of the direction of the target's angular momentum, is shown to be associated with oscillatory behavior of the dK for certain transitions. Finally, several strategies for obtaining the dK coefficients from experimental data are discussed.

Infield X-ray diffraction studies of field and temperature driven structural phase transition in Nd{sub 0.49}Sr{sub 0.51}MnO{sub 3+δ}

Energy Technology Data Exchange (ETDEWEB)

Shahee, Aga, E-mail: agashahee@gmail.com [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452001 (India); Department of Physics, IIT Bombay, Powai, Mumbai 400076 (India); Sharma, Shivani; Singh, K.; Lalla, N.P. [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452001 (India)

2017-07-15

Highlights: • Temperature and magnetic field driven coupled magneto-structural phase transition in Nd{sub 0.49}Sr{sub 0.51}MnO{sub 3+δ}. • Microscopic evidence of strong spin-charge-lattice coupling. • Iso-thermal magnetic field driven structure phase transition. • Field-driven structural phase transition origin of observed 1st order type CMR effect. - Abstract: Comprehensive X-ray diffraction (XRD) studies have been performed at different temperature (T) (4.2–300 K) and magnetic field (H) (0–8 T) to understand the evolution of crystal structure of Nd{sub 0.49}Sr{sub 0.51}MnO{sub 3+δ} (NSMO) under non ambient conditions. The T dependent XRD results show the abrupt change in the lattice parameters without any change in lattice symmetry at ∼200 K, which is associated with the first order structural phase transition from ferromagnetic to antiferromagnetic phase. This phase transition is strongly H dependent and shifted to lower temperature (∼150 K) on the application of 8 T field with phase coexistence (high temperature phase ∼18%), even down to 4.2 K. Isothermal XRD results at 150 K under different H clearly illustrate the H induced first order structural phase transition. The critical H at which this phase transformation starts is ∼1 T, with rapid growth above 4 T with hysteretic nature during increasing and decreasing H. These results are supported with the resistivity and magnetoresistance results and affirm the strong spin-lattice coupling in NSMO. Our detail studies reveal the structural correlations to the observed colossal magnetoresistance and magnetocaloric effect in this material.

Search for 14.4 keV solar axions emitted in the M1-transition of $^{57}$Fe nuclei with CAST

CERN Document Server

Andriamonje, S; Autiero, D; Barth, K; Belov, A; Beltrán, B; Bräuninger, H; Carmona, J M; Cebrián, S; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Eleftheriadis, C; Englhauser, J; Fanourakis, G K; Ferrer-Ribas, E; Fischer, H; Franz, J; Friedrich, P; Geralis, T; Giomataris, Yu; Gninenko, S; Gómez, H; Hasinoff, M; Heinsius, F H; Hoffmann, D H H; Irastorza, I G; Jacoby, J; Jakovčić, K; Kang, D; Königsmann, K C; Kotthaus, R; Krčmar, M; Kousouris, K; Kuster, M; Lakić, B; Lasseur, C; Liolios, A; Ljubičić, A; Lutz, G; Luzón, G; Miller, D; Morales, J; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Riege, H; Rodríguez, A; Ruz, J; Savvidis, I; Semertzidis, Y; Serpico, P; Stewart, L; Vieira, J; Villar, J; Vogel, J; Walckiers, L; Zioutas, K

2009-01-01

We have searched for 14.4 keV solar axions or more general axion-like particles (ALPs), that may be emitted in the M1 nuclear transition of 57Fe, by using the axion-to-photon conversion in the CERN Axion Solar Telescope (CAST) with evacuated magnet bores (Phase I). From the absence of excess of the monoenergetic X-rays when the magnet was pointing to the Sun, we set model-independent constraints on the coupling constants of pseudoscalar particles that couple to two photons and to a nucleon g_{a\\gamma} |-1.19 g_{aN}^{0}+g_{aN}^{3}|<1.36\\times 10^{-16} GeV^{-1} for m_{a}<0.03 eV at the 95% confidence level.

Effect of the annealing temperature on the structural and magnetic behaviors of 0.875La{sub 0.6}Ca{sub 0.4}MnO{sub 3}/0.125La{sub 0.6}Sr{sub 0.4}MnO{sub 3} composition

Energy Technology Data Exchange (ETDEWEB)

Gharsallah, H. [Laboratoire de Physique Appliquée, Faculté des Sciences, Université de Sfax, B.P. 1171, 3000 Sfax (Tunisia); Institut Préparatoire aux Études d’Ingénieur de Sfax, Université de Sfax, BP 1172, 3018 Sfax (Tunisia); Bejar, M., E-mail: bejar_moez@yahoo.fr [Laboratoire de Physique Appliquée, Faculté des Sciences, Université de Sfax, B.P. 1171, 3000 Sfax (Tunisia); Dhahri, E. [Laboratoire de Physique Appliquée, Faculté des Sciences, Université de Sfax, B.P. 1171, 3000 Sfax (Tunisia); Hlil, E.K. [Institut Néel, CNRS Université J. Fourier, BP166, 38042 Grenoble (France); Sajieddine, M. [Laboratoire de Physique et Mécanique des Matériaux, Faculté des Sciences et Techniques, Université Sultan Moulay Slimane, BP 523, 23000 Béni-Mellal (Morocco)

2016-03-01

The polycrystalline compounds of La{sub 0.6}Ca{sub 0.4}MnO{sub 3} (S0C1) and La{sub 0.6}Sr{sub 0.4}MnO{sub 3} (S1C0) were prepared using the citric–gel method. With the resultant nanoparticle powders having crystallite size of 22.51 nm from S0C1 and 27.39 nm from S1C0, the 0.875(S0C1)0.125(S1C0) composition was sintered at different temperatures: SC. 4-1 (at 700 °C), SC. 4-2 (at 900 °C), SC. 4-3 (at 1100 °C) and SC. 4-4 (at 1300 °C). XRD data were analyzed by Rietveld refinement technique. The two S0C1 and S1C0 mother compounds were found to crystallize in the rhombohedral and orthorhombic structure, respectively. The compounds sintered at 700 °C (SC. 4-1) and 900 °C (SC. 4-2) were found to present the two rhombohedral and orthorhombic phases corresponding to the mother compounds, which indicates that no interfacial reaction occurs. However, when augmenting the sintering temperature, the formation of the 0.875(S0C1)0.125(S1C0) new phase was observed. These observations were confirmed from the magnetization study, which revealed that the SC. 4-1 and SC. 4-2 compounds present two magnetic transitions temperature corresponding to the two mother compounds. For higher sintering temperature (1100 and 1300 °C), we have noted the presence of a new magnetic transition corresponding to the composition 0.875(S0C1)0.125(S1C0) compound. The variation of the M(T) curves were discussed in terms of the orthorhombic distortion σ{sup 2}(Mn–O). - Highlights: • Polycrystalline samples of S0C1 and S1C0 were prepared via citric-gel method. • 0.875(S0C1)0.125(S1C0) mixture was sintered at different temperatures. • The magnetic study revealed the presence of two magnetic transitions. • The M(T) curves variation were discussed in term of the orthorhombic distortion.

Seismomagnetic effects from the long-awaited 28 September 2004 M 6.0 parkfield earthquake

Science.gov (United States)

Johnston, M.J.S.; Sasai, Y.; Egbert, G.D.; Mueller, R.J.

2006-01-01

Precise measurements of local magnetic fields have been obtained with a differentially connected array of seven synchronized proton magnetometers located along 60 km of the locked-to-creeping transition region of the San Andreas fault at Parkfield, California, since 1976. The M 6.0 Parkfield earthquake on 28 September 2004, occurred within this array and generated coseismic magnetic field changes of between 0.2 and 0.5 nT at five sites in the network. No preseismic magnetic field changes exceeding background noise levels are apparent in the magnetic data during the month, week, and days before the earthquake (or expected in light of the absence of measurable precursive deformation, seismicity, or pore pressure changes). Observations of electric and magnetic fields from 0.01 to 20 Hz are also made at one site near the end of the earthquake rupture and corrected for common-mode signals from the ionosphere/magnetosphere using a second site some 115 km to the northwest along the fault. These magnetic data show no indications of unusual noise before the earthquake in the ULF band (0.01-20 Hz) as suggested may have preceded the 1989 ML 7.1 Loma Prieta earthquake. Nor do we see electric field changes similar to those suggested to occur before earthquakes of this magnitude from data in Greece. Uniform and variable slip piezomagnetic models of the earthquake, derived from strain, displacement, and seismic data, generate magnetic field perturbations that are consistent with those observed by the magnetometer array. A higher rate of longer-term magnetic field change, consistent with increased loading in the region, is apparent since 1993. This accompanied an increased rate of secular shear strain observed on a two-color EDM network and a small network of borehole tensor strainmeters and increased seismicity dominated by three M 4.5-5 earthquakes roughly a year apart in 1992, 1993, and 1994. Models incorporating all of these data indicate increased slip at depth in the region

FoxM1 promotes epithelial-mesenchymal transition of hepatocellular carcinoma by targeting Snai1

OpenAIRE

Yu, Chun-Peng; Yu, Shui; Shi, Lei; Wang, Song; Li, Zi-Xiang; Wang, Yan-Hua; Sun, Cheng-Jian; Liang, Jun

2017-01-01

Forkhead box protein M1 (FoxM1) is aberrantly expressed in several types of human malignancy, and serves an important role in tumor metastasis. Epithelial-mesenchymal transition (EMT) of cancer cells has been associated cancer metastasis; however, the implication of FoxM1 in EMT and its putative roles in the regulation of cancer metastasis remain to be elucidated. In the present study, the expression of FoxM1, Snai1 and E-cadherin in hepatocellular carcinoma (HCC) cell lines with various meta...

Structural phase transition at the percolation threshold in epitaxial (La0.7Ca0.3MnO3)1-x:(MgO)x nanocomposite films.

Science.gov (United States)

Moshnyaga, V; Damaschke, B; Shapoval, O; Belenchuk, A; Faupel, J; Lebedev, O I; Verbeeck, J; van Tendeloo, G; Mücksch, M; Tsurkan, V; Tidecks, R; Samwer, K

2003-04-01

'Colossal magnetoresistance' in perovskite manganites such as La0.7Ca0.3MnO3 (LCMO), is caused by the interplay of ferro-paramagnetic, metal-insulator and structural phase transitions. Moreover, different electronic phases can coexist on a very fine scale resulting in percolative electron transport. Here we report on (LCMO)1-x:(MgO)x (0 strain. The largest colossal magnetoresistance of 10(5)% was observed at the percolation threshold in the conductivity at xc 0.3, which is coupled to a structural phase transition from orthorhombic (0 < x < or 0.1) to rhombohedral R3c structure (0.33 < or = x < or = 0.8). An increase of the Curie temperature for the Rc phase was observed. These results may provide a general method for controlling the magnetotransport properties of manganite-based composite films by appropriate choice of the second phase.

Measurement of the $B^0$--$\\bar B^0$ oscillation frequency $\\Delta m_d$ with the decays $B^0 \\to D^- \\pi^+$ and $B^0 \\to J\\ \\psi K^{*0}$

CERN Document Server

INSPIRE-00258707; Abellan Beteta, C; Adametz, A; Adeva, B; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves Jr, A A; Amato, S; Amhis, Y; Anderlini, L; Anderson, J; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Baesso, C; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bates, A; Bauer, Th; Bay, A; Beddow, J; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M -O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blanks, C; Blouw, J; Blusk, S; Bobrov, A; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Büchler-Germann, A; Burducea, I; Bursche, A; Buytaert, J; Cadeddu, S; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Cauet, Ch; Charles, M; Charpentier, Ph; Chen, P; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Corti, G; Couturier, B; Cowan, G A; Craik, D; Cunliffe, S; Currie, R; D'Ambrosio, C; David, P; David, P N Y; De Bonis, I; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Simone, P; Decamp, D; Deckenhoff, M; Degaudenzi, H; Del Buono, L; Deplano, C; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dickens, J; Dijkstra, H; Diniz Batista, P; Dogaru, M; Domingo Bonal, F; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisenhardt, S; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Elsby, D; Falabella, A; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Furcas, S; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garnier, J-C; Garofoli, J; Garosi, P; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hampson, T; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Harrison, P F; Hartmann, T; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Hill, D; Hoballah, M; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Ilten, P; Imong, J; Jacobsson, R; Jaeger, A; Jahjah Hussein, M; Jans, E; Jansen, F; Jaton, P; Jean-Marie, B; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kaballo, M; Kandybei, S; Karacson, M; Karbach, T M; Kenyon, I R; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kim, Y M; Kochebina, O; Komarov, V; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J -P; Lefèvre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Li, Y; Li Gioi, L; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; von Loeben, J; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Lu, H; Luisier, J; Luo, H; Mac Raighne, A; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Magnin, J; Maino, M; Malde, S; Manca, G; Mancinelli, G; Mangiafave, N; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Matveev, M; Maurice, E; Mazurov, A; McCarthy, J; McGregor, G; McNulty, R; Meissner, M; Merk, M; Merkel, J; Milanes, D A; Minard, M -N; Molina Rodriguez, J; Monteil, S; Moran, D; Morawski, P; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Muster, B; Mylroie-Smith, J; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neufeld, N; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Nikitin, N; Nikodem, T; Nomerotski, A; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Pal, B K; Palano, A; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perego, D L; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petridis, K; Petrolini, A; Phan, A; Picatoste Olloqui, E; Pie Valls, B; Pietrzyk, B; Pilař, T; Pinci, D; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pugatch, V; Puig Navarro, A; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Rives Molina, V; Roa Romero, D A; Robbe, P; Rodrigues, E; Rodriguez Perez, P; Rogers, G J; Roiser, S; Romanovsky, V; Romero Vidal, A; Rouvinet, J; Ruf, T; Ruiz, H; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salzmann, C; Sanmartin Sedes, B; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santinelli, R; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Schaack, P; Schiller, M; Schindler, H; Schleich, S; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M -H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Skwarnicki, T; Smith, N A; Smith, E; Smith, M; Sobczak, K; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Subbiah, V K; Swientek, S; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urner, D; Uwer, U; Vagnoni, V; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Videau, I; Vieira, D; Vilasis-Cardona, X; Visniakov, J; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; Voss, H; Waldi, R; Wallace, R; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wishahi, J; Witek, M; Witzeling, W; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, F; Xing, Z; Yang, Z; Young, R; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhong, L; Zvyagin, A

2013-01-01

The $B^0$--$\\bar B^0$ oscillation frequency $\\Delta m_d$ is measured by the LHCb experiment using a dataset corresponding to an integrated luminosity of $1.0\\,$fb$^{-1}$ of proton-proton collisions at $\\sqrt{s} = 7\\,$TeV, and is found to be $\\Delta m_d = 0.5156 \\pm 0.0051\\,($stat.$) \\pm 0.0033\\,($syst.$)\\,$ps$^{-1}$. The measurement is based on results from analyses of the decays $B^0 \\to D^- \\pi^+$ ($D^- \\to K^+ \\pi^- \\pi^-$) and $B^0 \\to J\\ \\psi K^{*0}$ ($J\\ \\psi \\to \\mu^+ \\mu^-$, $K^{*0} \\to K^+ \\pi^-$) and their charge conjugated modes.

The evolution of low-mass close binary systems. IV. 0.80 M/sub sun/+0.40 M/sub sun/: Catastrophic mass loss

International Nuclear Information System (INIS)

Webbink, R.F.

1977-01-01

The evolution of both components of a 0.80 M/sub sun/+0.40 M/sub sun/ binary with initial separation 1.60 R/sub sun/ is presented. This system reaches mass transfer during core hydrogen burning in the primary. The primary has such a deep convective envelope that mass transfer proceeds on a dynamical time scale. Mass exchange is followed through the first 6.25 x 10 -3 M/sub sun/, by which time the transfer rate has reached 8.33 x 10 -4 M/sub sun/ yr -1 .It is shown that mass transfer on a dynamical time scale leads to supercritical accretion by the secondary component, and hence is presumably accompanied by extensive mass and angular momentum losses. Stability against such rapid mass transfer may impose severe limitations on the masses and mass ratios of cataclysmic variables

Investigation of temperature effect on half-life periods of long-lived isomer sup 1 sup 8 sup 0 sup m Hf and sup 8 sup 7 sup m Sr

CERN Document Server

Alpatov, V G; Davydov, A V; Isaev, Y N; Kartashov, G R; Korotkov, M M; Samojlov, V M

2001-01-01

The experiments on measuring the half-life periods of the sup 1 sup 8 sup 0 sup m Hf and sup 8 sup 7 sup m Sr long-lived isomers at the room temperature and at 77 K with application of the HfO sub 2 , Sr(NO sub 3) sub 2 and SrCO sub 3 massive samples are described. The isomer states of the corresponding nuclei were formed by the samples irradiation through neutrons from the Pu-Be source. According to the Vysotski theory and other authors the surrounding of the gamma-active nuclei by a large number of the same nuclei in the basic state should lead to the T sub 1 sub / sub 2 growth due to distortion of the zero electromagnetic vacuum oscillations near the nuclear energy level value. Decrease in the sample temperature leads to the narrowing of the gamma-lines, especially for the Moessbauer low-energy transitions, which increases the resonance effect on the zero oscillations spectrum. Increase in the T sub 1 sub / sub 2 by 2.99 +- 0.87% was observed by cooling the sup 1 sup 8 sup 0 sup m Hf isomer sample, in the ...

Natural strong CP conservation in flipped physics

Energy Technology Data Exchange (ETDEWEB)

Frampton, P.H. (Institute of Field Physics, Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC (USA)); Kephart, T.W. (Department of Physics and Astronomy, Vanderbilt University, Nashville, TN (USA))

1990-08-13

A natural axion-free solution of the strong {ital CP} problem {ital at} {ital tree} {ital level} is noted within an E(6) grand unified theory. Using this as a springboard, it is shown that several flipped SU(5) theories which occur in superstring phenomenology contain within them a mechanism which enforces {bar {theta}}=0 at high accuracy.

Magnetic transitions in the system YBa2Cu/sub 2.8/Co/sub 0.2/O/sub 6+y/

International Nuclear Information System (INIS)

Miceli, P.F.; Tarascon, J.M.; Barboux, P.; Greene, L.H.; Bagley, B.G.; Hull, G.W.; Giroud, M.; Rhyne, J.J.; Neumann, D.A.; National Institute of Standards and Technology, Gaithersburg, Maryland 20899)

1989-01-01

We have studied the oxygen dependence of the two magnetic transitions (antiferromagnetic ordering of chains and planes) in YBa 2 Cu/sub 2.8/Co/sub 0.2/O/sub 6+y/ using neutron scattering. It is found that both transition temperatures increase with decreasing oxygen concentration. At y approx. 0.37 ( equivalent to y 0 ) the two transition temperatures are equal, so that chains and planes order at a single transition temperature for y less than or equal to y/sub 0/. For y=1 the compound is superconducting at 60 K. Therefore, this system qualitatively exhibits the magnetic and superconducting properties of pure YBa 2 Cu 3 O/sub 6+y/ while providing important insight on the oxygen dependence of chain site magnetic ordering. A discussion is presented which also includes results on Ni and Al substitutions

Diets high in resistant starch increase plasma levels of trimethylamine-N-oxide, a gut microbiome metabolite associated with CVD risk

Energy Technology Data Exchange (ETDEWEB)

Bergeron, Nathalie; Williams, Paul T.; Lamendella, Regina; Faghihnia, Nastaran; Grube, Alyssa; Li, Xinmin; Wang, Zeneng; Knight, Rob; Jansson, Janet K.; Hazen, Stanley L.; Krauss, Ronald M.

2016-12-20

Production of trimethylamine-<italic>N>-oxide (TMAO), a biomarker of CVD risk, is dependent on intestinal microbiota, but little is known of dietary conditions promoting changes in gut microbial communities. Resistant starches (RS) alter the human microbiota. We sought to determine whether diets varying in RS and carbohydrate (CHO) content affect plasma TMAO levels. We also assessed postprandial glucose and insulin responses and plasma lipid changes to diets high and low in RS. In a cross-over trial, fifty-two men and women consumed a 2-week baseline diet (41 percentage of energy (%E) CHO, 40 % fat, 19 % protein), followed by 2-week high- and low-RS diets separated by 2-week washouts. RS diets were assigned at random within the context of higher (51–53 %E)<italic>v>. lower CHO (39–40 %E) intake. Measurements were obtained in the fasting state and, for glucose and insulin, during a meal test matching the composition of the assigned diet. With lower CHO intake, plasma TMAO, carnitine, betaine and<italic>γ>-butyrobetaine concentrations were higher after the high-<italic>v>. low-RS diet (<italic>P><0·01 each). These metabolites were not differentially affected by high<italic>v>. low RS when CHO intake was high. Although the high-RS meal reduced postprandial insulin and glucose responses when CHO intake was low (<italic>P><0·01 each), RS did not affect fasting lipids, lipoproteins, glucose or insulin irrespective of dietary CHO content. In conclusion, a lower-CHO diet high in RS was associated with higher plasma TMAO levels. These findings, together with the absence of change in fasting lipids, suggest that short-term high-RS diets do not improve markers of cardiometabolic health.

0(gs)+ -->2(1)+ transition strengths in 106Sn and 108Sn.

Science.gov (United States)

Ekström, A; Cederkäll, J; Fahlander, C; Hjorth-Jensen, M; Ames, F; Butler, P A; Davinson, T; Eberth, J; Fincke, F; Görgen, A; Górska, M; Habs, D; Hurst, A M; Huyse, M; Ivanov, O; Iwanicki, J; Kester, O; Köster, U; Marsh, B A; Mierzejewski, J; Reiter, P; Scheit, H; Schwalm, D; Siem, S; Sletten, G; Stefanescu, I; Tveten, G M; Van de Walle, J; Van Duppen, P; Voulot, D; Warr, N; Weisshaar, D; Wenander, F; Zielińska, M

2008-07-04

The reduced transition probabilities, B(E2; 0(gs)+ -->2(1)+), have been measured in the radioactive isotopes (108,106)Sn using subbarrier Coulomb excitation at the REX-ISOLDE facility at CERN. Deexcitation gamma rays were detected by the highly segmented MINIBALL Ge-detector array. The results, B(E2;0(gs)+ -->2(1)+)=0.222(19)e2b2 for 108Sn and B(E2; 0(gs)+-->2(1)+)=0.195(39)e2b2 for 106Sn were determined relative to a stable 58Ni target. The resulting B(E2) values are approximately 30% larger than shell-model predictions and deviate from the generalized seniority model. This experimental result may point towards a weakening of the N=Z=50 shell closure.

Metal-insulator transition upon heating and negative-differential-resistive-switching induced by self-heating in BaCo0.9Ni0.1S1.8

International Nuclear Information System (INIS)

Fisher, B.; Genossar, J.; Chashka, K. B.; Patlagan, L.; Reisner, G. M.

2014-01-01

The layered compound BaCo 1−x Ni x S 2−y (0.05  1−x Ni x S 2−y (nominal x = 0.1 and y = 0.2). These were due to the steep metal to insulator transition upon heating followed by the activated behavior of the resistivity above the transition. The major role of Joule heating in switching is supported by the absence of nonlinearity in the current as function of voltage, I(V), obtained in pulsed measurements, in the range of electric fields relevant to d.c. measurements. The voltage-controlled negative differential resistance around the threshold for switching was explained by a simple model of self-heating. The main difficulty in modeling I(V) from the samples resistance as function of temperature R(T) was the progressive increase of R(T), and to a lesser extend the decrease of the resistance jumps at the transitions, caused by the damage induced by cycling through the transitions by heating or self-heating. This was dealt with by following systematically R(T) over many cycles and by using the data of R(T) in the heating cycle closest to that of the self-heating one

Study of associated gamma from niobium under 14. 9 MeV neutron bombardments

Energy Technology Data Exchange (ETDEWEB)

Zhou Hongyu; Yan Yiming; Fan Guoying; Lan Liqiac; Sun Suxu; Wang Qi; Hua Ming; Han Chongzhen; Liu Shuzhenn; Rong Yaning; and others

1989-02-01

The gamma ray spectra from niobium under 14.9 MeV neutron bombardments were measured by means of a pulsed /ital T/(/ital d/, /ital n/)/sup 4/He neutron source, associated particle method, Ge(Li) detector and time-of-flight technique at 7 angles between 30/degree/ and 140/degree/. 79 gamma lines were determined by a high resolution gamma spectrum analysis program, and reaction types and transition levels of 62 lines were roughly assigned. There were 40 ones of 79 lines, which were first found in reactions induced by neutrons. The differential cross sections of every gamma line at 7 angles were determined. It is shown that associated gamma ray emissions from this reaction are basically isotropic.

Investigation of structure, specific heat and superconducting transition in Mg1-xAlxB2(x∼0.5)

International Nuclear Information System (INIS)

Xiang, J.Y.; Zheng, D.N.; Lang, P.L.; Zhao, Z.X.; Luo, J.L.

2004-01-01

We have carried out structure, magnetic and specific heat measurements on aluminum doped magnetism diboride samples Mg 1-x Al x B 2 in order to investigate possible superconductivity at the x=0.5 concentration. A diamagnetic signal was observed in magnetization measurements accompanied by a decrease in resistivity. However, the diamagnetic signal was extremely small as compared to what expected from full diamagnetism. Also, the transition both in magnetization and resistance was very broad. We propose that the diamagnetism is due to a very small amount of superconducting phase such as MgB 2 and the resistive transition is due to the percolation behavior. Furthermore, we performed specific heat measurements, which are considered as a tool to investigate the bulk nature of superconducting transition, on the x=0.5 sample to verify the existence of superconductivity. We observed no evident superconducting transition in the entire temperature region from 2 to 300 K. The undistinguishable data between 0 and 5 T magnetic fields also indicated the absence of bulk superconductivity in the x=0.5 sample

Thermal-induced structural transition and depolarization behavior in (Bi0.5Na0.5)TiO3-BiAlO3 ceramics

Science.gov (United States)

Peng, Ping; Nie, Hengchang; Cheng, Guofeng; Liu, Zhen; Wang, Genshui; Dong, Xianlin

2018-03-01

The depolarization temperature Td determines the upper temperature limit for the application of piezoelectric materials. However, the origin of depolarization behavior for Bi-based materials still remains controversial and the mechanism is intricate for different (Bi0.5Na0.5)TiO3-based systems. In this work, the structure and depolarization behavior of (1-x)(Bi0.5Na0.5)TiO3-xBiAlO3 (BNT-BA, x = 0, 0.02, 0.04, 0.06, 0.07) ceramics were investigated using a combination of X-ray diffraction and electrical measurements. It was found that as temperature increased, the induced long-range ferroelectric phase irreversibly transformed to the relaxor phase as evidenced by the temperature-dependent ferroelectric and dielectric properties, which corresponded to a gradual structural change from the rhombohedral to the pseudocubic phase. Therefore, the thermal depolarization behavior of BNT-BA ceramics was proposed to be directly related to the rhombohedral-pseudocubic transition. Furthermore, Td (obtained from thermally stimulated depolarization currents curves) was higher than the induced ferroelectric-relaxor phase transition temperature TFR (measured from dielectric curves). The phenomenon was quite different from other reported BNT-based systems, which may suggest the formation of polar nanoregions (PNRs) within macrodomains prior to the detexturation of short-range ferroelectric domains with PNRs or nanodomains.

Inflationary and deflationary branches in extended pre-big-bang cosmology

Energy Technology Data Exchange (ETDEWEB)

Lidsey, J.E. [Astronomy Unit, School of Mathematical Sciences, Queen Mary Westfield, Mile End Road, London, E1 4NS (United Kingdom)

1997-03-01

The pre-big-bang cosmological scenario is studied within the context of the Brans-Dicke theory of gravity. An epoch of superinflationary expansion may occur in the pre-big-bang phase of the Universe{close_quote}s history in a certain region of parameter space. Two models are considered that contain a cosmological constant in the gravitational and matter sectors of the theory, respectively. Classical pre- and post-big-bang solutions are found for both models. The existence of a curvature singularity forbids a classical transition between the two branches. On the other hand, a quantum cosmological approach based on the tunneling boundary condition results in a nonzero transition probability. The transition may be interpreted as a spatial reflection of the wave function in minisuperspace. {copyright} {ital 1997} {ital The American Physical Society}

The Effect of Oxygen Flow on the Transition Temperature of Hg0.75Pb0.25Sr2-yBayCa2Cu3O8+ δ Superconductors

Science.gov (United States)

Jasim, Kareem A.; Al-Khafaji, Raghad S.

2018-05-01

In this paper, there are three different high temperature superconductors which are Hg0.75Pb0.25Sr2-y BayCa2Cu3O8+δ with deferent weight fractions y = 0.10, 0.20 and 0.25 that have been prepared successfully by solid state reaction and the samples have been equipped with/without O2 flow. The optimum calcinations is 1073 K and the sintering process that has been achieved within 1128-1133 K. Transition temperature Tc has been found by using four probe technique through electrical resistivity measurements. The greatest Tc that has been found for Hg0.75Pb0.25Sr1.75 Ba0.25Ca2Cu3O8.31 is 115 oK. Oxygen content (O2) flow exhibits high-phased superconductors that is similar to the samples prepared without O2. Investigation of X-ray diffraction (XRD) is revealed (tetragonal structure) by the c-axis lattice parameter increasing of the samples substituted with Ba. It has been established, from the calculated results, that the Ba variation concentrations of all samples products a modification in the density (ρm), (c/a) and volume fraction (VPh(2223)).

Magnetodielectric behaviour in La0.53Ca0.47MnO3

International Nuclear Information System (INIS)

Pandey, Suchita; Kumar, Jitender; Awasthi, A M

2014-01-01

We explore magneto-dielectricity in La 0.53 Ca 0.47 MnO 3 across its paramagnetic (PMI) to ferromagnetic (FMM) isostructural transition at T C  ∼ 253 K, by magnetic (M), caloric (W), dielectric (ε′), magnetoresistive (MR), and magnetocapacitance (MC) investigations. A skew-broadened first-order transition character is confirmed via heating/cooling hystereses in M(T) and W(T), with a superheating temperature T ** next to T C and supercooling temperature T * exhibiting kinetics. Above T C , linearly related MC and MR reflect purely a magnetoresistance effect. Near T C , the high-frequency MC (5 Tesla (T)), far exceeds the magneto-losses, and is uncorrelated with dc MR (5 T) in the FM-ordered state. The intrinsic magneto-dielectricity manifest below T C and above ∼kHz is traced to an intra-granular Maxwell–Wagner-type effect at the interface region of PMI–FMM phase coexistence. (paper)

Combustion synthesis and characterization of MV0.5P0.5O4: Sm3+, Tm3+ (M = Gd, La, Y)

Science.gov (United States)

Motloung, Selepe J.; Lephoto, Mantwa A.; Tshabalala, Kamohelo G.; Ntwaeaborwa, Odireleng M.

2018-04-01

In this paper, GdV0.5P0.5O4: Sm3+, Tm3+, LaV0.5P0.5O4: Sm3+, Tm3+ and YV0.5P0.5O4: Sm3+, Tm3+ phosphor powders were prepared by solution combustion method using urea as a fuel. The phase purity, surface morphology, optical and photoluminescence properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis spectroscopy and photoluminescence spectroscopy. The XRD results indicated that the prepared powders are of a single phase and crystallized in tetragonal structure for Gd and Y systems while monoclinic phase was observed for La system. SEM showed that the samples consisted of mixed structures. The estimated band gaps were 2.2, 2.4 and 2.3 eV for Y, Gd and La systems respectively. The photoluminescence results showed four emission peaks. One peak is assigned to 1G4 - 3H6 transition of Tm3+, and three other emission peaks are attributed to 6G5/2 - 6H5/2, 6G5/2 - 6H7/2 and 6G5/2 - 6H9/2 transitions of Sm3+. The photoluminescent intensity was the highest in the gadolinium system.

Near-infrared (0.8-4.0 m) spectroscopy of mimas, enceladus, tethys, and rhea

Science.gov (United States)

Emery, J.P.; Burr, D.M.; Cruikshank, D.P.; Brown, R.H.; Dalton, J.B.

2005-01-01

Spectral measurements from the ground in the time leading up to the Cassini mission at Saturn provide important context for the interpretation of the forthcoming spacecraft data. Whereas ground-based observations cannot begin to approach the spatial scales Cassini will achieve, they do possess the benefits of better spectral resolution, a broader possible time baseline, and unique veiewing geometries not obtained by spacecraft (i.e., opposition). In this spirit, we present recent NIR reflectance spectra of four icy satellites of Saturn measured with the SpeX instrument at the IRTF. These measurements cover the range 0.8-4.0 m of both the leading and trailing sides of Tethys and the leading side of Rhea. The L-band region (2.8-4.0 m) offers new opportunities for searches of minor components on these objects. Additionally, these data include 0.8-2.5 m spectra of both the leading and trailing sides of Mimas and of the (mostly) trailing side of Enceladus. The spectrum of Enceladus shows activity near 2.25 m that we interpret as a possible signature of NH3 ice. The presence of ammonia in the Saturn system is not unexpected, and may help explain the apparent recent geologic activity of Enceladus. Analysis of leading/trailing differences inH2O band depths, spectral slopes, and albedo imply a separate regime of surface modification for Mimas and Enceladus than for the more distant icy satellites (Tethys, Dione, Rhea). Aside from the potential NH3 on Enceladus, no other minor constituents are detected in these icy surfaces.

Crystal structure of a 2:1 piroxicam–gentisic acid co-crystal featuring neutral and zwitterionic piroxicam molecules

Energy Technology Data Exchange (ETDEWEB)

Horstman, Elizabeth M.; Bertke, Jeffery A.; Woods, Toby J.; Kenis, Paul J. A.

2016-11-04

A new 2:1 co-crystal of piroxicam and gentisic acid [systematic name: 4-hydroxy-1,1-dioxo-<italic>N>-(pyridin-2-yl)-2<italic>H>-1λ⁶,2-benzothiazine-3-carboxamide–2-(4-oxido-1,1-dioxo-2<italic>H>-1λ⁶,2-benzothiazine-3-amido)pyridin-1-ium–2,5-dihydroxybenzoic acid, 2C₁₅H₁₃N₃O₄S·C₇H₆O₄] has been synthesized using a microfluidic platform and initially identified using Raman spectroscopy. In the co-crystal, one piroxicam molecule is in its neutral form and an intramolecular O—H...O hydrogen bond is observed. The other piroxicam molecule is zwitterionic (proton transfer from the OH group to the pyridine N atom) and two intramolecular N—H...O hydrogen bonds occur. The gentisic acid molecule shows whole-molecule disorder over two sets of sites in a 0.809(2):0.191(2) ratio. In the crystal, extensive hydrogen bonding between the components forms layers propagating in the<italic>ab>plane.

Structural, magnetic and magnetocaloric properties of La{sub 0.8}Ca{sub 0.2−x}Na{sub x}MnO{sub 3} manganites (0≤x≤0.2)

Energy Technology Data Exchange (ETDEWEB)

Choura Maatar, S. [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Sfax University, B.P. 1171, 3000 Sfax (Tunisia); M’nassri, R. [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Sfax University, B.P. 1171, 3000 Sfax (Tunisia); Institut NEEL, CNRS, B.P.166, 38042 Grenoble Cedex 9 (France); Cheikhrouhou Koubaa, W., E-mail: wissem.koubaa@yahoo.fr [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Sfax University, B.P. 1171, 3000 Sfax (Tunisia); Koubaa, M. [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Sfax University, B.P. 1171, 3000 Sfax (Tunisia); Cheikhrouhou, A. [Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax, Sfax University, B.P. 1171, 3000 Sfax (Tunisia); Centre de Recherche en Informatique, Multimédia et Traitement Numérique des Données, Technopole de Sfax, Cité El Ons, Route de Tunis, Km 9, Sfax. B.P. 275, Sakiet Ezzit, 3021 Sfax (Tunisia)

2015-05-15

In this work, we report the effect of Na doping on the structural, magnetic and magnetocaloric properties in La{sub 0.8}Ca{sub 0.2−x}Na{sub x}MnO{sub 3} powder samples. Our polycristalline samples have been synthesized using the solid-state reaction method at high temperatures. The parent compound La{sub 0.8}Ca{sub 0.2}MnO{sub 3} crystallizes in the orthorhombic system with Pbnm space group. Na doping induces a structural transition from orthorhombic (Pbnm space group) to rhombohedral (R-3C space group) symmetry. Magnetization measurements versus temperature in a magnetic applied field of 50 mT showed that all our investigated samples display a paramagnetic-ferromagnetic transition with decreasing temperature. The Curie temperature T{sub C} increases with Na content from 240 K for x=0 to 330 K for x=0.2. A large magnetocaloric effect has been observed in all samples, the maximum entropy change, |∆S{sub M}|{sub max}, shifts to smaller values with increasing Na content, from4.56 J/kg K (x=0.05) to 2.3 J/kg K (x=0.2) under a magnetic field change ∆µ{sub 0}H of 2 T. For the same applied magnetic field of 2 T, the Relative Cooling Power (RCP) values are found to be constant around 91 J/kg. - Graphical abstract: Sodium doping induces an increase of T{sub C} from 240 K for x=0 to 330 K for x=0.2. - Highlights: • La{sub 0.8}Ca{sub 0.2−x}Na{sub x}MnO{sub 3} are synthesized using the ceramic method at high temperatures. • Na doping induces a structural transition from Pbnm to R-3C space group. • T{sub C} increases with Na content from 240 K for x=0 to 330 K for x=0.2. • RCP is constant around 91 J/kg for all compounds under 2 T.

Intermartensitic transitions in Ni-Mn-Fe-Cu-Ga Heusler alloys

International Nuclear Information System (INIS)

Khan, Mahmud; Gautam, Bhoj; Pathak, Arjun; Dubenko, Igor; Stadler, Shane; Ali, Naushad

2008-01-01

A series of Fe doped Ni 2 Mn 0.75-x Fe x Cu 0.25 Ga Heusler alloys have been investigated by means of x-ray diffraction, magnetizations, thermal expansion, and electrical resistivity measurements. In Ni 2 Mn 0.75 Cu 0.25 Ga, martensitic and ferromagnetic transitions occur at the same temperature. Partial substitution of Mn by Fe results in a decrease of the martensitic transition temperature, T M , and an increase of the ferromagnetic transition temperature, T C , resulting in separation of the two transitions. In addition to the martensitic transition, complete thermoelastic intermartensitic transformations have been observed in the Fe doped Ni 2 Mn 0.75-x Fe x Cu 0.25 Ga samples with x>0.04. An unusual transition is observed in the alloy with x = 0.04. The magnetization curve as a function of increasing temperature shows only one first-order transition in the temperature range 5-400 K, which is identified as a typical coupled magnetostructural martensitic transformation. The magnetization curve as a function of decreasing temperature shows three different transitions, which are characterized as the ferromagnetic transition, the martensitic transition and the intermartensitic transition.

Three small transiting planets around the M-dwarf host star LP 358-499

Science.gov (United States)

Wells, R.; Poppenhaeger, K.; Watson, C. A.

2018-01-01

We report on the detection of three transiting small planets around the low-mass star LP 358-499 (K2-133), using photometric data from the Kepler-K2 mission. Using multiband photometry, we determine the host star to be an early M dwarf with an age likely older than a gigayear. The three detected planets K2-133 b, c and d have orbital periods of ca. 3, 4.9 and 11 d and transit depths of ca. 700, 1000 and 2000 ppm, respectively. We also report a planetary candidate EPIC 247887989.01 with a period of 26.6 d and a depth of ca. 1000 ppm, which may be at the inner edge of the stellar habitable zone, depending on the specific host star properties. Using the transit parameters and the stellar properties, we estimate that the innermost planet may be rocky. The system is suited for follow-up observations to measure planetary masses and JWST transmission spectra of planetary atmospheres.

First Observation of the M1 Transition psi -> gamma eta(c)(2S)

NARCIS (Netherlands)

Ablikim, M.; Achasov, M. N.; Ambrose, D. J.; An, F. F.; An, Q.; An, Z. H.; Bai, J. Z.; Ban, Y.; Becker, J.; Berger, N.; Bertani, M.; Bian, J. M.; Boger, E.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Bytev, V.; Cai, X.; Calcaterra, A.; Cao, G. F.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, Y.; Chen, Y. B.; Cheng, H. P.; Chu, Y. P.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; Ding, W. M.; Ding, Y.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Fang, J.; Fang, S. S.; Fava, L.; Feldbauer, F.; Feng, C. Q.; Ferroli, R. B.; Fu, C. D.; Fu, J. L.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y. P.; Han, Y. L.; Hao, X. Q.; Harris, F. A.; He, K. L.; He, M.; He, Z. Y.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, H. M.; Hu, J. F.; Hu, T.; Huang, B.; Huang, G. M.; Huang, J. S.; Huang, X. T.; Huang, Y. P.; Hussain, T.; Ji, C. S.; Ji, Q.; Ji, X. B.; Ji, X. L.; Jia, L. K.; Jiang, L. L.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jing, F. F.; Kalantar-Nayestanaki, N.; Kavatsyuk, M.; Kuehn, W.; Lai, W.; Lange, J. S.; Leung, J. K. C.; Li, C. H.; Li, Cheng; Li, Cui; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, K.; Li, Lei; Li, N. B.; Li, Q. J.; Li, S. L.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, X. R.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Liao, X. T.; Liu, B. J.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, C. Y.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, H.; Liu, H. B.; Liu, H. H.; Liu, H. M.; Liu, H. W.; Liu, J. P.; Liu, K. Y.; Liu, Kai; Liu, Kun; Liu, P. L.; Liu, S. B.; Liu, X.; Liu, X. H.; Liu, Y.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H.; Lu, G. R.; Lu, H. J.; Lu, J. G.; Lu, Q. W.; Lu, X. R.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Lv, M.; Ma, C. L.; Ma, F. C.; Ma, H. L.; Ma, Q. M.; Ma, S.; Ma, T.; Ma, X. Y.; Ma, Y.; Maas, F. E.; Maggiora, M.; Malik, Q. A.; Mao, H.; Mao, Y. J.; Mao, Z. P.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Morales, C. Morales; Motzko, C.; Muchnoi, N. Yu.; Nefedov, Y.; Nicholson, C.; Nikolaev, I. B.; Ning, Z.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Park, J. W.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Prencipe, E.; Pun, C. S. J.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, X. S.; Qin, Y.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Rong, G.; Ruan, X. D.; Sarantsev, A.; Schaefer, B. D.; Schulze, J.; Shao, M.; Shen, C. P.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, X. Y.; Spataro, S.; Spruck, B.; Sun, D. H.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. D.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Thorndike, E. H.; Tian, H. L.; Toth, D.; Ullrich, M.; Varner, G. S.; Wang, B.; Wang, B. Q.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q.; Wang, Q. J.; Wang, S. G.; Wang, X. F.; Wang, X. L.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. Y.; Wei, D. H.; Weidenkaff, P.; Wen, Q. G.; Wen, S. P.; Werner, M.; Wiedner, U.; Wu, L. H.; Wu, N.; Wu, S. X.; Wu, W.; Wu, Z.; Xia, L. G.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, G. M.; Xu, H.; Xu, Q. J.; Xu, X. P.; Xu, Y.; Xu, Z. R.; Xue, F.; Xue, Z.; Yan, L.; Yan, W. B.; Yan, Y. H.; Yang, H. X.; Yang, T.; Yang, Y.; Yang, Y. X.; Ye, H.; Ye, M.; Ye, M. H.; Yu, B. X.; Yu, C. X.; Yu, J. S.; Yu, L.; Yu, S. P.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. G.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, L.; Zhang, S. H.; Zhang, T. R.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. S.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, H. S.; Zhao, J. W.; Zhao, K. X.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, S. J.; Zhao, T. C.; Zhao, X. H.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, Y. H.; Zheng, Z. P.; Zhong, B.; Zhong, J.; Zhou, L.; Zhou, X. K.; Zhou, X. R.; Zhu, C.; Zhu, K.; Zhu, K. J.; Zhu, S. H.; Zhu, X. L.; Zhu, X. W.; Zhu, Y. M.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.; Zuo, J. X.

2012-01-01

Using a sample of 106 x 10(6) psi(3686) events collected with the BESIII detector at the BEPCII storage ring, we have made the first measurement of the M1 transition between the radially excited charmonium S-wave spin-triplet and the radially excited S-wave spin-singlet states: psi(3686) -> gamma

Predicted stability, structures, and magnetism of 3d transition metal nitrides: the M4N phases

NARCIS (Netherlands)

Fang, C.M.; Koster, R.S.; Li, W.F.; van Huis, M.A.

2014-01-01

The 3d transition metal nitrides M4N (Sc4N, Ti4N, V4N, Cr4N, Mn4N, Fe4N, Co4N, Ni4N, and Cu4N) have unique phase relationships, crystal structures, and electronic and magnetic properties. Here we present a systematic density functional theory (DFT) study on these transition metal nitrides, assessing

Some observations on the synthesis and electrolytic properties of (Ba1-xCax (M0.9Y0.1O3, M = Ce, Zr-based samples modified with calcium

Directory of Open Access Journals (Sweden)

Dudek Magdalena

2016-03-01

Full Text Available In this paper, the impact of partial substitution of calcium for barium in (Ba1-xCax (M0.9Y0.1 O3, M = Ce, Zr on physicochemical properties of the powders and sintered samples was investigated. The powders, with various contents of calcium (x = 0, 0.02, 0.05, 0.1, were prepared by means of thermal decomposition of organometallic precursors containing EDTA. All of the BaCeO3-based powders synthesised at 1100 °C were monophasic with a rhombohedral structure, however, completely cubic BaZrO3-based solid solutions were obtained at 1200 °C. A study of the sinterability of BaZr0.9Y0.1O3 and BaCe0.9Y0.1O3-based pellets was performed under non-isothermal conditions within a temperature range of 25 to 1200 °C. The partial substitution of barium for calcium in the (Ba1-xCax (M0.9Y0.1 O3, M = Ce, Zr solid solution improved the sinterability of the samples in comparison to the initial BaCe0.9Y0.1O3 or BaZr0.9Y0.1O3. The relative density of calcium-modified BaCe0.9Y0.1O3-based samples reached approximately 95 to 97 % after sintering at 1500 °C for 2 h in air. The same level of relative density was achieved after sintering calcium-modified BaZr0.9Y0.1O3 at 1600 °C for 2 h. Analysis of the electrical conductivity from both series of investigated materials showed that the highest ionic conductivity, in air and wet 5 % H2 in Ar, was attained for the compositions of x = 0.02 to 0.05 (Ba1-xCax(M0.9Y0.1O3, M = Zr, Ce. The oxygen reduction reaction on the interface Pt│BaM0.9Y0.1O3, M = Ce, Zr was investigated using Pt microelectrodes. Selected samples of (Ba1-xCax (M0.9Y0.1O3, M = Zr, Ce were tested as ceramic electrolytes in hydrogen-oxygen solid oxide fuel cells operating at temperatures of 700 to 850 °C.

Identification of candidates for postmastectomy radiotherapy in patients with pT3N0M0 breast cancer

International Nuclear Information System (INIS)

Hamamoto, Yasushi; Ohsumi, Shozo; Aogi, Kenjiro; Takashima, Shigemitsu; Shinohara, Shuichi; Nakajima, Naomi; Kataoka, Masaaki

2013-01-01

There is still controversy concerning the indication of postmastectomy radiotherapy (PMRT) for pT3N0M0 breast cancer. To identify the candidates for PMRT in this subset, we investigated failure patterns, and searched for risk factors for isolated locoregional failure in pT3N0M0 breast cancer after mastectomy without PMRT. Among 1,176 patients who received mastectomy without PMRT for untreated unilateral breast cancer between 1990 and 2002, 64 patients (5%) had pT3N0M0 breast cancer (age 30-81 years; median 52.5 years). Isolated locoregional failure as the initial failure occurred in three patients. For all 64 patients, the 8-year failure-free survival rate, the isolated locoregional failure-free rate, and the distant failure-free rate were 76, 93, and 82%, respectively. Incidence of isolated locoregional failure as the initial failure was 18% (2/11) for patients 40 years or younger and 2% (1/53) for patients older than 40 years. The 8-year isolated locoregional failure-free rates were 73% for patients 40 years or younger and 98% for patients older than 40 years (p=0.0135). Concerning pT3N0M0 breast cancer, incidence of isolated locoregional failure was comparatively low after mastectomy without PMRT. Routine use of PMRT for all pT3N0M0 patients seemed to be unacceptable. PMRT may be useful for younger patients because of the comparatively high incidence of isolated locoregional failure. Because of the small number of cases in our series, further studies are necessary to determine the usefulness of PMRT for younger patients with pT3N0M0 breast cancer. (author)

Pressure-induced magnetic transition in CeP

International Nuclear Information System (INIS)

Naka, T.; Matsumoto, T.; Mori, N.; Okayama, Y.; Haga, Y.; Suzuki, T.

1997-01-01

Pressure dependence of magnetization in CeP is investigated up to 2 GPa. Multi-step transitions are induced by pressure. An antiferromagnetic transition at T N =11 K below 0.1 GPa develops into two (magnetic) transitions at T L and T H in the region of 0.1 L , T H and T d above 1.3 GPa. For decreasing temperature an abrupt increase of magnetization, M(T), has been observed below T H and a round maximum of magnetization appears at T L for P≥0.4 GPa. Above 1.3 GPa, an anomalous decrease of M(T) begins at T d =10 K. Using previously reported 31 P-NMR shift data it is shown that the pressure dependence of a characteristic temperature, which is proportional to the crystal field splitting in the paramagnetic temperature region, decreases rapidly with increasing pressure. (orig.)

0-π transition in a superconductor/carbon nanotube quantum dot/superconductor junction

International Nuclear Information System (INIS)

Yu Yong; Liang Qifeng; Dong Jinming

2010-01-01

Josephson current, passing through a superconductor/carbon nanotube quantum dot/superconductor junction (S/CNT-QD/S), has been investigated using the nonequilibrium Green's function method in the Hartree-Fock approximation, where the characteristic two orbital degrees of freedom of the carbon nanotubes (CNTs) are considered as the orbital pseudospins, which has an important effect on the transport properties of the S/CNT-QD/S junction. It has been found that: 1) If the orbital pseudospin doesn't conserve in the Cooper pair's tunneling process, the 0-π phase transition of the junction appears when the average electron occupation number in the CNT-QDs is odd, which is well consistent with the experimental observations. 2) More importantly, if the orbital pseudospin conserves, the 0-π phase transition could appear for the junction with an even average electron occupation number on the CNT-QDs, in contrast with an odd number of electrons in the ordinary QDs of the S/QD/S junctions, which is predicted to be possibly observed in future experiment with a weak cross scattering between the two orbital channels of the CNTs. (author)

Theoretical expression of the internal conversion coefficient of a M1 transition between two atomic states

International Nuclear Information System (INIS)

Attallah, F.; Chemin, J.F.; Scheurer, J.N.; Karpeshin, F.; Harston, M.

1997-01-01

We have established a general relation for the expression of the internal conversion of an M 1 transition a 1s electronic state to an empty ns electronic bound state. Under the hypothesis that the density of the electron level ρ n satisfies the condition ρ n Γ >> 1 (where Γ is the total width of the excited atomic state) a calculation in the first order gives a relation for the internal conversion coefficient.This relation shows that the internal conversion coefficient takes a resonant character when the nuclear energy transition is smaller than the binding energy of the 1s electron. An application of this relation to an M 1 transition in the case of the ion 125 T e with a charge state Q = 45 and an 1s electron binding energy E B 45 = 35.581 KeV gives the value for the internal conversion coefficient R = 5.7

Magnetic and magnetocaloric properties of HoCr0.75Fe0.25O3 compound

Science.gov (United States)

Kotnana, Ganesh; Babu, P. D.; Jammalamadaka, S. Narayana

2018-05-01

We report on the magnetic and magnetocaloric properties of HoCr0.75Fe0.25O3 compound around the Néel temperature (TN), which is due to Cr3+ ordering. Susceptibility (χ) vs. temperature (T) graph of HoCr0.75Fe0.25O3 compound infer two transitions due to the ordering of Cr3+ moments (TN ˜ 155 K) and Ho3+ moments (TNHo ˜ 8 K). Magnetic entropy (-ΔSM) value of 1.14 J kg-1 K-1 around 157.5 K with a magnetic field (H) of 90 kOe is attributed to antiferromagnetic (AFM) ordering of Cr3+ moments. A maximum value of adiabatic temperature (ΔTad) ˜ 0.41 K around TN is obtained and is found to increases with applied magnetic field. Negative slope for H/M vs. M2 graph is evident for HoCr0.75Fe0.25O3 compound below TN, which indicates the first order phase transition. Quantified values of -ΔSM and ΔTad open the way to explore rare earth orthochromites for the MCE properties and refrigeration applications.

Saliva transit in patients with gastroesophageal reflux disease.

Science.gov (United States)

Cassiani, R A; Mota, G A; Aprile, L R O; Dantas, R O

2015-10-01

Saliva is an important factor in the neutralization of the acidity of the refluxed material that comes from the stomach to the esophagus. The impairment of saliva transit from oral cavity to distal esophagus may be one of the causes of esophagitis and symptoms in gastroesophageal reflux disease (GERD). With the scintigraphic method, the transit of 2 mL of artificial saliva was measured in 30 patients with GERD and 26 controls. The patients with GERD had symptoms of heartburn and acid regurgitation, a 24-hour pH monitoring with more than 4.2% of the time with pH below four, 26 with erosive esophagitis, and four with non-erosive reflux disease. Fourteen had mild dysphagia for solid foods. Twenty-one patients had normal esophageal manometry, and nine had ineffective esophageal motility. They were 15 men and 15 women, aged 21-61 years, mean 39 years. The control group had 14 men and 12 women, aged 19-61 years, mean 35 years. The subjects swallowed in the sitting and supine position 2 mL of artificial saliva labeled with 18 MBq of (99m) Technetium phytate. The time of saliva transit was measured from oral cavity to esophageal-gastric transition, from proximal esophagus to esophageal-gastric transition, and the transit through proximal, middle, and distal esophageal body. There was no difference between patients and controls in the time for saliva to go from oral cavity to esophageal-gastric transition, and from proximal esophagus to esophageal-gastric transition, in the sitting and supine positions. In distal esophagus in the sitting position, the saliva transit duration was shorter in patients with GERD (3.0 ± 0.8 seconds) than in controls (7.6 ± 1.7 seconds, P = 0.03). In conclusion, the saliva transit from oral cavity to the esophageal-gastric transition in patients with GERD has the same duration than in controls. Saliva transit through the distal esophageal body is faster in patients with GERD than controls. © 2014 International Society for Diseases of the

Radionuclide Esophageal Transit Scintigraphy in Primary Hypothyroidism.

Science.gov (United States)

Khan, Shoukat H; P, Madhu Vijay; Rather, Tanveer A; Laway, Bashir A

2017-01-30

Esophageal dysmotility is associated with gastrointestinal dysmotility in various systemic and neuroregulatory disorders. Hypothyroidism has been reported to be associated with impaired motor function in esophagus due to accumulation of glycosaminoglycan hyaluronic acid in its soft tissues, leading to changes in various contraction and relaxation parameters of esophagus, particularly in the lower esophageal sphincter. In this study we evaluated esophageal transit times in patients of primary hypothyroidism using the technique of radionuclide esophageal transit scintigraphy. Thirty-one patients of primary hypothyroidism and 15 euthyroid healthy controls were evaluated for esophageal transit time using 15-20 MBq of Technetium-99m sulfur colloid diluted in 10-15 mL of drinking water. Time activity curve was generated for each study and esophageal transit time was calculated as time taken for clearance of 90% radioactive bolus from the region of interest encompassing the esophagus. Esophageal transit time of more than 10 seconds was considered as prolonged. Patients of primary hypothyroidism had a significantly increased mean esophageal transit time of 19.35 ± 20.02 seconds in comparison to the mean time of 8.25 ± 1.71 seconds in healthy controls ( P < 0.05). Esophageal transit time improved and in some patients even normalized after treatment with thyroxine. A positive correlation ( r = 0.39, P < 0.05) albeit weak existed between the serum thyroid stimulating hormone and the observed esophageal transit time. A significant number of patients with primary hypothyroidism may have subclinical esophageal dysmotility with prolonged esophageal transit time which can be reversible by thyroxine treatment. Prolonged esophageal transit time in primary hypothyroidism may correlate with serum thyroid stimulating hormone levels.

EXAFS study of Mn1.28Fe0.67P0.46Si0.54 compound with first-order phase transition

International Nuclear Information System (INIS)

L, Yingjie; Huliyageqi, B; Haschaolu, W; Song, Zhiqiang; Tegus, O; Nakai, Ikuo

2014-01-01

Highlights: • We have investigated the Fe and Mn K edge XAFS spectra of the Mn 1.28 Fe 0.67 P 0.46 Si 0.54 compound at 25 K and 295 K. • The site occupation of the Fe and Mn atoms and local structure of Mn 1.28 Fe 0.67 P 0.46 Si 0.54 are determined. • The atomic distances between Fe–Fe in c-plane for the ferromagnetic state are larger than those in the paramagnetic state. - Abstract: The Fe 2 P-type MnFe(P,Si) compounds are investigated by means of magnetic measurements and X-ray absorption fine structure spectroscopy. Magnetic measurements show that the Mn 1.28 Fe 0.67 P 0.46 Si 0.54 compound undergoes a first-order phase transition at the Curie temperature of 254 K. The Fe K-edge and Mn K-edge X-ray absorption fine structure spectra show that Mn atom mainly located at the 3g sites, while the 3f sites are occupied by Fe atoms and Mn atom randomly. The distances between the Fe atom and its nearest neighbor atoms in a triangle Fe–Mn–Fe change from 2.80 Å at 25 K to 2.74 Å at 300 K. On the other hand, the distances between Fe atom and its second neighbor atoms change from 4.06 Å at 25 K to 4.02 Å at 300 K

Metal-insulator transition upon heating and negative-differential-resistive-switching induced by self-heating in BaCo{sub 0.9}Ni{sub 0.1}S{sub 1.8}

Energy Technology Data Exchange (ETDEWEB)

Fisher, B.; Genossar, J.; Chashka, K. B.; Patlagan, L.; Reisner, G. M. [Physics Department, Technion-Israel Institute of Technology, Haifa 32000 (Israel)

2014-04-14

The layered compound BaCo{sub 1−x}Ni{sub x}S{sub 2−y} (0.05 < x < 0.2 and 0.05 < y < 0.2) exhibits an unusual first-order structural and electronic phase transition from a low-T monoclinic paramagnetic metal to a high-T tetragonal antiferromagnetic insulator around 200 K with huge hysteresis (∼40 K) and large volume change (∼0.01). Here, we report on unusual voltage-controlled resistive switching followed by current-controlled resistive switching induced by self-heating in polycrystalline BaCo{sub 1−x}Ni{sub x}S{sub 2−y} (nominal x = 0.1 and y = 0.2). These were due to the steep metal to insulator transition upon heating followed by the activated behavior of the resistivity above the transition. The major role of Joule heating in switching is supported by the absence of nonlinearity in the current as function of voltage, I(V), obtained in pulsed measurements, in the range of electric fields relevant to d.c. measurements. The voltage-controlled negative differential resistance around the threshold for switching was explained by a simple model of self-heating. The main difficulty in modeling I(V) from the samples resistance as function of temperature R(T) was the progressive increase of R(T), and to a lesser extend the decrease of the resistance jumps at the transitions, caused by the damage induced by cycling through the transitions by heating or self-heating. This was dealt with by following systematically R(T) over many cycles and by using the data of R(T) in the heating cycle closest to that of the self-heating one.

Nucleic acid helices: I. Structure of M1 RNA from E. coli as determined bypsoralen crosslinking. II. Thermodynamics of the helix-coil transition of DNA oligonucleotides in solutions containing 3. 0 M tetramethylammonium chloride

Energy Technology Data Exchange (ETDEWEB)

Lipson, S.E.

1987-01-01

This work includes two different investigations examining nucleic acid helices. The first study discusses secondary and tertiary interactions in the RNA moiety of ribonuclease P from Escherichia coli. The second study discusses the thermodynamics of the helix-coil transition of DNA oligonucleotides in solutions containing tetramethylammonium chloride. The RNA moiety of ribonuclease P from Escherichia coli (M1 RNA) has been photoreacted with 4{prime}-hydroxymethyl-4,5{prime}8-trimethylpsoralen and long wave UV light (320-380 nm) in a buffer in which the M1 RNA alone acts as a true catalyst of tRNA processing. Limited specific digestion followed by two dimensional gel electrophoresis yields fragments crosslinked by HMT. The positions of the crosslinks have been determined to within {plus minus}15 nucleotides by photoreversal of the isolated crosslinked fragments and enzymatic sequencing of the resulting RNA. Further assignments of the exact locations of the crosslinks have been made on the known photoreactivity of the psoralen with different bases.

Nucleic acid helices: I. Structure of M1 RNA from E. coli as determined bypsoralen crosslinking. II. Thermodynamics of the helix-coil transition of DNA oligonucleotides in solutions containing 3.0 M tetramethylammonium chloride

International Nuclear Information System (INIS)

Lipson, S.E.

1987-01-01

This work includes two different investigations examining nucleic acid helices. The first study discusses secondary and tertiary interactions in the RNA moiety of ribonuclease P from Escherichia coli. The second study discusses the thermodynamics of the helix-coil transition of DNA oligonucleotides in solutions containing tetramethylammonium chloride. The RNA moiety of ribonuclease P from Escherichia coli (M1 RNA) has been photoreacted with 4'-hydroxymethyl-4,5'8-trimethylpsoralen and long wave UV light (320-380 nm) in a buffer in which the M1 RNA alone acts as a true catalyst of tRNA processing. Limited specific digestion followed by two dimensional gel electrophoresis yields fragments crosslinked by HMT. The positions of the crosslinks have been determined to within ±15 nucleotides by photoreversal of the isolated crosslinked fragments and enzymatic sequencing of the resulting RNA. Further assignments of the exact locations of the crosslinks have been made on the known photoreactivity of the psoralen with different bases

Radiative rates for E1, E2, M1 and M2 transitions in Fe X

International Nuclear Information System (INIS)

Aggarwal, K.M.; Keenan, F.P.

2004-01-01

Energies of the 54 levels belonging to the (1s 2 2s 2 2p 6 ) 3s 2 3p 5 , 3s3p 6 , 3s 2 3p 4 3d and 3s3p 5 3d configurations of Fe X have been calculated using the GRASP code of Dyall and colleagues (1989). Additionally, radiative rates, oscillator strengths, and line strengths are calculated for all electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2), and magnetic quadrupole (M2) transitions among these levels. Comparisons are made with results available in the literature, and the accuracy of the data is assessed. Our energy levels are estimated to be accurate to better than 3%, whereas results for other parameters are probably accurate to better than 20% . Additionally, the agreement between measured and calculated lifetimes is better than 10%. (authors)

Extrasolar Planet Transits Observed at Kitt Peak National Observatory

Science.gov (United States)

Sada, Pedro V.; Jennings, Donald E.; Deming, Drake; Jennings, Donald E.; Jackson, Brian; Hamilton, Catrina M.; Fraine, Jonathan; Peterson, Steven W.; Haase, Flynn; Bays, Kevin;

Proton and gamma -Rays Irradiation-Induced Dark Current Random Telegraph Signal in a 0.18-mu{{m}} CMOS Image Sensor