Sample records for large momentum transfers

  1. Generalized parton distributions at large momentum transfer

    E-print Network

    P. Kroll

    2001-06-18

    The role of generalized parton distributions in wide-angle exclusive reactions will be discussed. In contrast to deep virtual exclusive reactions the wide angle processes offer the possibility of investigating the generalized parton distributions at large momentum transfer.

  2. Large momentum transfer electroproduction of mesons

    E-print Network

    H. W. Huang; P. Kroll

    2000-05-31

    Assuming the proton's light-cone wave function to be dominated by small parton virtualities and small intrinsic transverse momenta, we show that the electroproduction amplitudes at large momentum transfer factorize into parton-level subprocess amplitudes and form factors representing 1/x-moments of skewed parton distributions. On the basis of a wave function overlap model for the form factors we present detailed predictions for the electroproduction cross sections. We also comment on large momentum transfer photoproduction.

  3. Electromagnetic Form Factors at Large Momentum Transfer

    E-print Network

    P. Kroll

    1994-09-08

    Recent improvements of the hard scattering picture for the large $p_{\\perp}$ behaviour of electromagnetic form factors, namely the inclusion of both Sudakov corrections and intrinsic transverse momentum dependence of the hadronic wave function, are reviewed. On account of these improvements the perturbative contributions to the pion's and the nucleon's form factor can be calculated in a theoretically self-consistent way for momentum transfers as low as about $2$ and $3\\,{\\rm GeV}$, respectively. This is achieved at the expense of a substantial suppression of the perturbative contribution in the few GeV region. Eventual higher twist contributions are discussed in some detail.

  4. Measurement of J/ ? photoproduction at large momentum transfer at HERA

    NASA Astrophysics Data System (ADS)

    Chekanov, S.; Derrick, M.; Magill, S.; Musgrave, B.; Nicholass, D.; Repond, J.; Yoshida, R.; Mattingly, M. C. K.; Antonioli, P.; Bari, G.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Cindolo, F.; Corradi, M.; Iacobucci, G.; Margotti, A.; Nania, R.; Polini, A.; Antonelli, S.; Basile, M.; Bindi, M.; Cifarelli, L.; Contin, A.; de Pasquale, S.; Sartorelli, G.; Zichichi, A.; Bartsch, D.; Brock, I.; Hartmann, H.; Hilger, E.; Jakob, H.-P.; Jüngst, M.; Nuncio-Quiroz, A. E.; Paul, E.; Samson, U.; Schönberg, V.; Shehzadi, R.; Wlasenko, M.; Morris, J. D.; Kaur, M.; Kaur, P.; Singh, I.; Capua, M.; Fazio, S.; Mastroberardino, A.; Schioppa, M.; Susinno, G.; Tassi, E.; Kim, J. Y.; Ibrahim, Z. A.; Mohamad Idris, F.; Kamaluddin, B.; Wan Abdullah, W. A. T.; Ning, Y.; Ren, Z.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Galas, A.; Olkiewicz, K.; Pawlik, B.; Stopa, P.; Zawiejski, L.; Adamczyk, L.; Bo?d, T.; Grabowska-Bo?d, I.; Kisielewska, D.; ?ukasik, J.; Przybycie?, M.; Suszycki, L.; Kota?ski, A.; S?omi?ski, W.; Bachynska, O.; Behnke, O.; Behr, J.; Behrens, U.; Blohm, C.; Borras, K.; Bot, D.; Ciesielski, R.; Coppola, N.; Fang, S.; Geiser, A.; Göttlicher, P.; Grebenyuk, J.; Gregor, I.; Haas, T.; Hain, W.; Hüttmann, A.; Januschek, F.; Kahle, B.; Katkov, I. I.; Klein, U.; Kötz, U.; Kowalski, H.; Libov, V.; Lisovyi, M.; Lobodzinska, E.; Löhr, B.; Mankel, R.; Melzer-Pellmann, I.-A.; Miglioranzi, S.; Montanari, A.; Namsoo, T.; Notz, D.; Parenti, A.; Roloff, P.; Rubinsky, I.; Schneekloth, U.; Spiridonov, A.; Szuba, D.; Szuba, J.; Theedt, T.; Tomaszewska, J.; Wolf, G.; Wrona, K.; Yagües-Molina, A. G.; Youngman, C.; Zeuner, W.; Drugakov, V.; Lohmann, W.; Schlenstedt, S.; Barbagli, G.; Gallo, E.; Pelfer, P. G.; Bamberger, A.; Dobur, D.; Karstens, F.; Vlasov, N. N.; Bussey, P. J.; Doyle, A. T.; Forrest, M.; Saxon, D. H.; Skillicorn, I. O.; Gialas, I.; Papageorgiu, K.; Holm, U.; Klanner, R.; Lohrmann, E.; Perrey, H.; Schleper, P.; Schörner-Sadenius, T.; Sztuk, J.; Stadie, H.; Turcato, M.; Long, K. R.; Tapper, A. D.; Matsumoto, T.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Barakbaev, A. N.; Boos, E. G.; Pokrovskiy, N. S.; Zhautykov, B. O.; Aushev, V.; Borodin, M.; Kadenko, I.; Korol, Ie.; Kuprash, O.; Lontkovskyi, D.; Makarenko, I.; Onishchuk, Yu.; Salii, A.; Sorokin, Iu.; Verbytskyi, A.; Viazlo, V.; Volynets, O.; Zenaiev, O.; Zolko, M.; Son, D.; de Favereau, J.; Piotrzkowski, K.; Barreiro, F.; Glasman, C.; Jimenez, M.; Del Peso, J.; Ron, E.; Terrón, J.; Uribe-Estrada, C.; Corriveau, F.; Schwartz, J.; Zhou, C.; Tsurugai, T.; Antonov, A.; Dolgoshein, B. A.; Gladkov, D.; Sosnovtsev, V.; Stifutkin, A.; Suchkov, S.; Dementiev, R. K.; Ermolov, P. F.; Gladilin, L. K.; Golubkov, Yu. A.; Khein, L. A.; Korzhavina, I. A.; Kuzmin, V. A.; Levchenko, B. B.; Lukina, O. Yu.; Proskuryakov, A. S.; Shcheglova, L. M.; Zotkin, D. S.; Abt, I.; Caldwell, A.; Kollar, D.; Reisert, B.; Schmidke, W. B.; Grigorescu, G.; Keramidas, A.; Koffeman, E.; Kooijman, P.; Pellegrino, A.; Tiecke, H.; Vázquez, M.; Wiggers, L.; Brümmer, N.; Bylsma, B.; Durkin, L. S.; Lee, A.; Ling, T. Y.; Cooper-Sarkar, A. M.; Devenish, R. C. E.; Ferrando, J.; Foster, B.; Gwenlan, C.; Horton, K.; Oliver, K.; Robertson, A.; Walczak, R.; Bertolin, A.; Dal Corso, F.; Dusini, S.; Longhin, A.; Stanco, L.; Brugnera, R.; Carlin, R.; Garfagnini, A.; Limentani, S.; Raval, A.; Whitmore, J. J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Hart, J. C.; Abramowicz, H.; Ingbir, R.; Kananov, S.; Levy, A.; Stern, A.; Ishitsuka, M.; Kanno, T.; Kuze, M.; Maeda, J.; Hori, R.; Okazaki, N.; Shimizu, S.; Hamatsu, R.; Kitamura, S.; Ota, O.; Ri, Y. D.; Costa, M.; Ferrero, M. I.; Monaco, V.; Sacchi, R.; Sola, V.; Solano, A.; Arneodo, M.; Ruspa, M.; Fourletov, S.; Martin, J. F.; Stewart, T. P.; Boutle, S. K.; Butterworth, J. M.; Jones, T. W.; Loizides, J. H.; Wing, M.; Brzozowska, B.; Ciborowski, J.; Grzelak, G.; Kulinski, P.; ?u?niak, P.; Malka, J.; Nowak, R. J.; Pawlak, J. M.; Perlanski, W.; ?arnecki, A. F.; Adamus, M.; Plucinski, P.; Tymieniecka, T.; Eisenberg, Y.; Hochman, D.; Karshon, U.; Brownson, E.; Reeder, D. D.; Savin, A. A.; Smith, W. H.; Wolfe, H.; Bhadra, S.; Catterall, C. D.; Hartner, G.; Noor, U.; Whyte, J.; ZEUS Collaboration

    2010-05-01

    The proton-dissociative diffractive photoproduction of J/ ? mesons has been studied in ep collisions with the ZEUS detector at HERA using an integrated luminosity of 112 pb-1. The cross section is presented as a function of the photon-proton centre-of-mass energy and of the squared four-momentum transfer at the proton vertex. The results are compared to perturbative QCD calculations.

  5. Photoproduction of the rho^0 Meson on the Proton at Large Momentum Transfer

    SciTech Connect

    M. Battaglieri; E. Anciant; M. Anghinolfi; R. De Vita; E. Golovach; J. M. Laget; V. Mokeev; M. Ripani; G. Adams; M. J. Amaryan; D. S. Armstrong; B. Asavapibhop; G. Asryan; G. Audit; T. Auger; H. Avakian; S. Barrow; K. Beard; M. Bektasoglu; B. L. Berman; N. Bianchi; A. S. Biselli; S. Boiarinov; D. Branford; W. J. Briscoe; W. K. Brooks; V. D. Burkert; J. R. Calarco; G. P. Capitani; D. S. Carman; B. Carnahan; A. Cazes; C. Cetina; P. L. Cole; A. Coleman; D. Cords; P. Corvisiero; D. Crabb; H. Crannell; J. P. Cummings; E. DeSanctis; P. V. Degtyarenko; R. Demirchyan; H. Denizli; L. Dennis; K. V. Dharmawardane; K. S. Dhuga; C. Djalali; G. E. Dodge; D. Doughty; P. Dragovitsch; M. Dugger; S. Dytman; M. Eckhause; H. Egiyan; K. S. Egiyan; L. Elouadrhiri; L. Farhi; R. J. Feuerbach; J. Ficenec; T. A. Forest; A. P. Freyberger; V. Frolov; H. Funsten; S. J. Gaff; M. Gai; S. Gilad; G. P. Gilfoyle; K. L. Giovanetti; K. Griffioen; M. Guidal; M. Guillo; V. Gyurjyan; D. Hancock; J. Hardie; D. Heddle; F. W. Hersman; K. Hicks; R. S. Hicks; M. Holtrop; C. E. Hyde-Wright; M. M. Ito; K. Joo; J. H. Kelley; M. Khandaker; W. Kim; A. Klein; F. J. Klein; M. Klusman; M. Kossov; L. H. Kramer; Y. Kuang; S. E. Kuhn; D. Lawrence; M. Lucas; K. Lukashin; R. W. Major; J. J. Manak; C. Marchand; S. McAleer; J. McCarthy; J. W. C. McNabb; B. A. Mecking; M. D. Mestayer; C. A. Meyer; K. Mikhailov; R. Minehart; M. Mirazita; R. Miskimen; V. Muccifora; J. Mueller; G. S. Mutchler; J. Napolitano; S. O. Nelson; B. B. Niczyporuk; R. A. Niyazov; J. T. O'Brien; A. K. Opper; G. Peterson; S. A. Philips; N. Pivnyuk; D. Pocanic; O. Pogorelko; E. Polli; B. M. Preedom; J. W. Price; D. Protopopescu; L. M. Qin; B. A. Raue; A. R. Reolon; G. Riccardi; G. Ricco; B. G. Ritchie; F. Ronchetti; P. Rossi; D. Rowntree; P. D. Rubin; K. Sabourov; C. Salgado; M. Sanzone-Arenhovel; V. Sapunenko; R. A. Schumacher; V. S. Serov; A. Shafi; Y. G. Sharabian; J. Shaw; A. V. Skabelin; E. S. Smith; T. Smith; L. C. Smith; D. I. Sober; M. Spraker; A. Stavinsky; S. Stepanyan; P. Stoler; M. Taiuti; S. Taylor; D. J. Tedeschi; L. Todor; R. Thompson; M. F. Vineyard; A. V. Vlassov; L. B. Weinstein; A. Weisberg; H. Weller; D. P. Weygand; C. S. Whisnant; E. Wolin; M. Wood; A. Yegneswaran; J. Yun; B. Zhang; J. Zhao; Z. Zhou

    2001-10-01

    The differential cross section, d{sigma}/dt, for p0 meson photoproduction on the proton above the resonance region was measured up to a momentum transfer -t = 5 GeV2 using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The p0 channel was extracted from the measured two charged-pion cross sections by fitting the {pi}+{pi}- and p{pi}+ invariant masses. The low momentum transfer region shows the typical diffractive pattern expected from Reggeon exchange. The flatter behavior at large -t cannot be explained solely in terms of QCD-inspired two-gluon exchange models. The data indicate that other processes, like quark interchange, are important to fully describe p photoproduction.

  6. Laser-assisted ionization-excitation of helium by electron impact at large momentum transfer

    NASA Astrophysics Data System (ADS)

    Bulychev, Andrey A.; Kouzakov, Konstantin A.

    2014-11-01

    Ionization of a helium atom by electron impact in the presence of laser radiation is studied theoretically. The kinematic regime of high impact energy and large momentum transfer is considered. The S-matrix of the process is treated within the first Born and binary-encounter approximations. Triple differential cross sections are calculated for the cases when the residual He+ ion is left both in the ground ( n = 1) and in the first excited ( n = 2) states in the presence of a laser field with frequency ? = 1.55 eV and intensity I = 5 × 1011 W/cm2. The laser-assisted cross sections corresponding to n = 2 are found to be more sensitive to the electron-electron correlations in helium than the field-free ones.

  7. Diffractive J/{Psi} photoproduction at large momentum transfer in coherent hadron-hadron interactions at CERN LHC

    SciTech Connect

    Sauter, W. K.; Goncalves, V. P. [High and Medium Energy Group (GAME), Instituto de Fisica e Matematica, Universidade Federal de Pelotas, Caixa Postal 354, CEP 96010-900, Pelotas, RS (Brazil)

    2010-11-12

    The vector meson production in coherent hadron-hadron interactions at LHC energies is addressed assuming that the color singlet t-channel exchange carries large momentum transfer. We consider the non-forward solution of the BFKL equation at high energy and large momentum transfer and estimate the rapidity distribution and total cross section for the process h{sub 1}h{sub 2{yields}}h{sub 1}J/{Psi}X, where h{sub i} can be a proton or a nucleus. We predict large rates, which implies that the experimental identification could be feasible at the LHC.

  8. Diffractive J/{Psi} photoproduction at large momentum transfer in coherent hadron-hadron interactions at CERN LHC

    SciTech Connect

    Goncalves, V. P.; Sauter, W. K. [High and Medium Energy Group (GAME), Instituto de Fisica e Matematica, Universidade Federal de Pelotas, Caixa Postal 354, CEP 96010-900, Pelotas, RS (Brazil)

    2010-04-01

    The vector meson production in coherent hadron-hadron interactions at LHC energies is studied assuming that the color singlet t-channel exchange carries large momentum transfer. We consider the nonforward solution of the Balitsky, Fadin, Kuraev, and Lipatov equation at high energy and large momentum transfer and estimate the rapidity distribution and total cross section for the process h{sub 1}h{sub 2{yields}}h{sub 1}J/{Psi}X, where h{sub i} can be a proton or a nucleus. We predict large rates, which implies that the experimental identification can be feasible at the LHC.

  9. Photoproduction of the omega Meson on the Proton at Large Momentum Transfer

    Microsoft Academic Search

    M. Battaglieri; M. Brunoldi; R. de Vita; J. M. Laget; M. Osipenko; M. Ripani; M. Taiuti; G. Adams; M. J. Amaryan; E. Anciant; M. Anghinolfi; D. S. Armstrong; B. Asavapibhop; G. Asryan; G. Audit; T. Auger; H. Avakian; S. Barrow; K. Beard; M. Bektasoglu; B. L. Berman; A. Bersani; N. Bianchi; A. S. Biselli; S. Boiarinov; S. Bouchigny; R. Bradford; D. Branford; W. J. Briscoe; W. K. Brooks; V. D. Burkert; J. R. Calarco; G. P. Capitani; D. S. Carman; B. Carnahan; A. Cazes; C. Cetina; P. L. Cole; A. Coleman; D. Cords; P. Corvisiero; D. Crabb; H. Crannell; J. P. Cummings; E. Desanctis; P. V. Degtyarenko; R. Demirchyan; H. Denizli; L. Dennis; K. V. Dharmawardane; K. S. Dhuga; C. Djalali; G. E. Dodge; D. Doughty; P. Dragovitsch; M. Dugger; S. Dytman; M. Eckhause; H. Egiyan; K. S. Egiyan; L. Elouadrhiri; L. Farhi; R. J. Feuerbach; J. Ficenec; T. A. Forest; A. P. Freyberger; V. Frolov; H. Funsten; S. J. Gaff; M. Gai; M. Garcon; G. P. Gilfoyle; S. Gilad; K. L. Giovanetti; E. Golovach; K. Griffioen; M. Guidal; M. Guillo; L. Guo; V. Gyurjyan; C. Hadjidakis; D. Hancock; J. Hardie; D. Heddle; F. W. Hersman; K. Hicks; R. S. Hicks; M. Holtrop; C. E. Hyde-Wright; M. M. Ito; K. Joo; J. H. Kelley; M. Khandaker; W. Kim; A. Klein; F. J. Klein; A. V. Klimenko; M. Klusman; M. Kossov; L. H. Kramer; Y. Kuang; S. E. Kuhn; J. Lachniet; D. Lawrence; M. Lucas; K. Lukashin; R. W. Major; J. J. Manak; C. Marchand; S. McAleer; J. McCarthy; J. W. McNabb; B. A. Mecking; M. D. Mestayer; C. A. Meyer; K. Mikhailov; M. Mirazita; R. Miskimen; V. Mokeev; S. Morrow; M. U. Mozer; V. Muccifora; J. Mueller; G. S. Mutchler; J. Napolitano; S. O. Nelson; S. Niccolai; B. B. Niczyporuk; R. A. Niyazov; M. Nozar; J. T. O'Brien; A. K. Opper; G. Peterson; S. A. Philips; N. Pivnyuk; D. Pocanic; O. Pogorelko; E. Polli; B. M. Preedom; J. W. Price; D. Protopopescu; L. M. Qin; B. A. Raue; A. R. Reolon; G. Riccardi; G. Ricco; B. G. Ritchie; F. Ronchetti; P. Rossi; D. Rowntree; P. D. Rubin; K. Sabourov; C. Salgado; V. Sapunenko; R. A. Schumacher; V. S. Serov; A. Stavinsky; Y. G. Sharabian; J. Shaw; A. V. Skabelin; E. S. Smith; T. Smith; L. C. Smith; D. I. Sober; M. Spraker; S. Stepanyan; P. Stoler; S. Taylor; D. J. Tedeschi; L. Todor; U. Thoma; R. Thompson; M. F. Vineyard; A. V. Vlassov; K. Wang; L. B. Weinstein; H. Weller; D. P. Weygand; C. S. Whisnant; E. Wolin; M. Wood; A. Yegneswaran; J. Yun; B. Zhang; J. Zhao; Z. Zhou

    2003-01-01

    The differential cross section, dsigma\\/dt, for omega meson exclusive photoproduction on the proton above the resonance region (2.6momentum transfer -t=5 GeV2 using the CLAS detector at Jefferson Laboratory. The omega channel was identified by detecting a proton and pi+ in the final state and using the missing mass technique. While the low momentum

  10. Photoproduction of the rho^0 Meson on the Proton at Large Momentum Transfer

    Microsoft Academic Search

    M. Battaglieri; E. Anciant; M. Anghinolfi; R. De Vita; E. Golovach; J. M. Laget; V. Mokeev; M. Ripani; G. Adams; M. J. Amaryan; D. S. Armstrong; B. Asavapibhop; G. Asryan; G. Audit; T. Auger; H. Avakian; S. Barrow; K. Beard; M. Bektasoglu; B. L. Berman; N. Bianchi; A. S. Biselli; S. Boiarinov; D. Branford; W. J. Briscoe; W. K. Brooks; V. D. Burkert; J. R. Calarco; G. P. Capitani; D. S. Carman; B. Carnahan; A. Cazes; C. Cetina; P. L. Cole; A. Coleman; D. Cords; P. Corvisiero; D. Crabb; H. Crannell; J. P. Cummings; E. DeSanctis; P. V. Degtyarenko; R. Demirchyan; H. Denizli; L. Dennis; K. V. Dharmawardane; K. S. Dhuga; C. Djalali; G. E. Dodge; D. Doughty; P. Dragovitsch; M. Dugger; S. Dytman; M. Eckhause; H. Egiyan; K. S. Egiyan; L. Elouadrhiri; L. Farhi; R. J. Feuerbach; J. Ficenec; T. A. Forest; A. P. Freyberger; V. Frolov; H. Funsten; S. J. Gaff; M. Gai; S. Gilad; G. P. Gilfoyle; K. L. Giovanetti; K. Griffioen; M. Guidal; M. Guillo; V. Gyurjyan; D. Hancock; J. Hardie; D. Heddle; F. W. Hersman; K. Hicks; R. S. Hicks; M. Holtrop; C. E. Hyde-Wright; M. M. Ito; K. Joo; J. H. Kelley; M. Khandaker; W. Kim; A. Klein; F. J. Klein; M. Klusman; M. Kossov; L. H. Kramer; Y. Kuang; S. E. Kuhn; D. Lawrence; M. Lucas; K. Lukashin; R. W. Major; J. J. Manak; C. Marchand; S. McAleer; J. McCarthy; J. W. C. McNabb; B. A. Mecking; M. D. Mestayer; C. A. Meyer; K. Mikhailov; R. Minehart; M. Mirazita; R. Miskimen; V. Muccifora; J. Mueller; G. S. Mutchler; J. Napolitano; S. O. Nelson; B. B. Niczyporuk; R. A. Niyazov; J. T. OBrien; A. K. Opper; G. Peterson; S. A. Philips; N. Pivnyuk; D. Pocanic; O. Pogorelko; E. Polli; B. M. Preedom; J. W. Price; D. Protopopescu; L. M. Qin; B. A. Raue; A. R. Reolon; G. Riccardi; G. Ricco; B. G. Ritchie; F. Ronchetti; P. Rossi; D. Rowntree; P. D. Rubin; K. Sabourov; C. Salgado; M. Sanzone-Arenhovel; V. Sapunenko; R. A. Schumacher; V. S. Serov; A. Shafi; Y. G. Sharabian; J. Shaw; A. V. Skabelin; E. S. Smith; T. Smith; L. C. Smith; D. I. Sober; M. Spraker; A. Stavinsky; S. Stepanyan; P. Stoler; M. Taiuti; S. Taylor; D. J. Tedeschi; L. Todor; R. Thompson; M. F. Vineyard; A. V. Vlassov; L. B. Weinstein; A. Weisberg; H. Weller; D. P. Weygand; C. S. Whisnant; E. Wolin; M. Wood; A. Yegneswaran; J. Yun; B. Zhang; J. Zhao; Z. Zhou

    2001-01-01

    The differential cross section, dÏ\\/dt, for p0 meson photoproduction on the proton above the resonance region was measured up to a momentum transfer -t = 5 GeV2 using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The p0 channel was extracted from the measured two charged-pion cross sections by fitting the Ï+Ï- and pÏ+ invariant masses. The low

  11. Photoproduction of the rho0 Meson on the Proton at Large Momentum Transfer

    Microsoft Academic Search

    M. Battaglieri; E. Anciant; M. Anghinolfi; R. de Vita; E. Golovach; J. M. Laget; V. Mokeev; M. Ripani; G. Adams; M. J. Amaryan; D. S. Armstrong; B. Asavapibhop; G. Asryan; G. Audit; T. Auger; H. Avakian; S. Barrow; K. Beard; M. Bektasoglu; B. L. Berman; N. Bianchi; A. S. Biselli; S. Boiarinov; D. Branford; W. J. Briscoe; W. K. Brooks; V. D. Burkert; J. R. Calarco; G. P. Capitani; D. S. Carman; B. Carnahan; A. Cazes; C. Cetina; P. L. Cole; A. Coleman; D. Cords; P. Corvisiero; D. Crabb; H. Crannell; J. P. Cummings; E. Desanctis; P. V. Degtyarenko; R. Demirchyan; H. Denizli; L. Dennis; K. V. Dharmawardane; K. S. Dhuga; C. Djalali; G. E. Dodge; D. Doughty; P. Dragovitsch; M. Dugger; S. Dytman; M. Eckhause; H. Egiyan; K. S. Egiyan; L. Elouadrhiri; L. Farhi; R. J. Feuerbach; J. Ficenec; T. A. Forest; A. P. Freyberger; V. Frolov; H. Funsten; S. J. Gaff; M. Gai; S. Gilad; G. P. Gilfoyle; K. L. Giovanetti; K. Griffioen; M. Guidal; M. Guillo; V. Gyurjyan; D. Hancock; J. Hardie; D. Heddle; F. W. Hersman; K. Hicks; R. S. Hicks; M. Holtrop; C. E. Hyde-Wright; M. M. Ito; K. Joo; J. H. Kelley; M. Khandaker; W. Kim; A. Klein; F. J. Klein; M. Klusman; M. Kossov; L. H. Kramer; Y. Kuang; S. E. Kuhn; D. Lawrence; M. Lucas; K. Lukashin; R. W. Major; J. J. Manak; C. Marchand; S. McAleer; J. McCarthy; J. W. McNabb; B. A. Mecking; M. D. Mestayer; C. A. Meyer; K. Mikhailov; R. Minehart; M. Mirazita; R. Miskimen; V. Muccifora; J. Mueller; G. S. Mutchler; J. Napolitano; S. O. Nelson; B. B. Niczyporuk; R. A. Niyazov; J. T. O'Brien; A. K. Opper; G. Peterson; S. A. Philips; N. Pivnyuk; D. Pocanic; O. Pogorelko; E. Polli; B. M. Preedom; J. W. Price; D. Protopopescu; L. M. Qin; B. A. Raue; A. R. Reolon; G. Riccardi; G. Ricco; B. G. Ritchie; F. Ronchetti; P. Rossi; D. Rowntree; P. D. Rubin; K. Sabourov; C. Salgado; M. Sanzone-Arenhovel; V. Sapunenko; R. A. Schumacher; V. S. Serov; A. Shafi; Y. G. Sharabian; J. Shaw; A. V. Skabelin; E. S. Smith; T. Smith; L. C. Smith; D. I. Sober; M. Spraker; A. Stavinsky; S. Stepanyan; P. Stoler; M. Taiuti; S. Taylor; D. J. Tedeschi; L. Todor; R. Thompson; M. F. Vineyard; A. V. Vlassov; L. B. Weinstein; A. Weisberg; H. Weller; D. P. Weygand; C. S. Whisnant; E. Wolin; M. Wood; A. Yegneswaran; J. Yun; B. Zhang; J. Zhao; Z. Zhou

    2001-01-01

    The differential cross section, dsigma\\/dt, for rho0 meson photoproduction on the proton above the resonance region was measured up to a momentum transfer -t = 5 GeV2 using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The rho0 channel was extracted from the measured two charged-pion cross sections by fitting the pi+pi- and ppi+ invariant masses. The low

  12. Measurement of Tensor Polarization in Elastic Electron-Deuteron Scattering at Large Momentum Transfer

    SciTech Connect

    David Abbott; Abdellah Ahmidouch; Heinz Anklin; Francois Arvieux; Jacques Ball; S. Beedoe; Elizabeth Beise; Louis Bimbot; Werner Boeglin; Herbert Breuer; Roger Carlini; Nicholas Chant; Samuel Danagoulian; K. Dow; Jean-Eric Ducret; James Dunne; Lars Ewell; Laurent Eyraud; Christophe Furget; Michel Garcon; Ronald Gilman; Charles Glashausser; Paul Gueye; Kenneth Gustafsson; Kawtar Hafidi; Adrian Honegger; Juerg Jourdan; Serge Kox; Gerfried Kumbartzki; L. Lu; Allison Lung; David Mack; Pete Markowitz; Justin McIntyre; David Meekins; Fernand Merchez; Joseph Mitchell; R. Mohring; Sekazi Mtingwa; Hamlet Mkrtchyan; David Pitz; Liming Qin; Ronald Ransome; Jean-Sebastien Real; Philip Roos; Paul Rutt; Reyad Sawafta; Samuel Stepanyan; Raphael Tieulent; Egle Tomasi-Gustafsson; William Turchinetz; Kelley Vansyoc; Jochen Volmer; Eric Voutier; William Vulcan; Claude Williamson; Stephen Wood; Chen Yan; Jie Zhao; Wenxia Zhao

    2000-05-01

    Tensor polarization observables (t20, t21 and t22) have been measured in elastic electron-deuteron scattering for six values of momentum transfer between 0.66 and 1.7 (GeV/c){sup 2}. The experiment was performed at the Jefferson Laboratory in Hall C using the electron HMS Spectrometer, a specially designed deuteron magnetic channel and the recoil deuteron polarimeter POLDER. The new data determine to much larger Q{sup 2} the deuteron charge form factors G{sub C} and G{sub Q}. They are in good agreement with relativistic calculations and disagree with pQCD predictions.

  13. Measurement of the Electric and Magnetic Elastic Structure Functions of the Deuteron at Large Momentum Transfers

    SciTech Connect

    Riad Suleiman

    1999-10-01

    The deuteron elastic structure functions, A(Q{sup 2}) and B(Q{sup 2}), have been extracted from cross section measurements of elastic electron-deuteron scattering in coincidence using the Continuous Electron Beam Accelerator and Hall A Facilities of Jefferson Laboratory. Incident electrons were scattered off a high-power cryogenic deuterium target. Scattered electrons and recoil deuterons were detected in the two High Resolution Spectrometers of Hall A. A(Q{sup 2}) was extracted from forward angle cross section measurements in the squared four-momentum transfer range 0.684 ? Q{sup 2} ? 5.90 (GeV/c){sup 2}. B(Q{sup 2}) was determined by means of a Rosenbluth separation in the range 0.684 ? Q{sup 2} ? 1.325 (GeV/c){sup 2}. The data are compared to theoretical models based on the impulse approximation with the inclusion of meson-exchange currents and to predictions of quark dimensional scaling and perturbative quantum chromodynamics. The results are expected to provide insights into the transition from meson-nucleon to quark-gluon descriptions of the nuclear two-body system.

  14. Sensitivity function analysis of gravitational wave detection with single-laser and large-momentum-transfer atomic sensors

    NASA Astrophysics Data System (ADS)

    Tang, Biao; Zhang, Bao-Cheng; Zhou, Lin; Wang, Jin; Zhan, Ming-Sheng

    2015-03-01

    Recently, a configuration using atomic interferometers (AIs) had been suggested for the detection of gravitational waves. A new AI with some additional laser pulses for implementing large momentum transfer was also put forward, in order to reduce the effect of shot noise and laser frequency noise. We use a sensitivity function to analyze all possible configurations of the new AI and to distinguish how many momenta are transferred in a specific configuration. By analyzing the new configuration, we further explore a detection scheme for gravitational waves, in particular, that ameliorates laser frequency noise. We find that the amelioration occurs in such a scheme, but novelly, in some cases, the frequency noise can be canceled completely by using a proper data processing method. Supported by the National Natural Science Foundation of China.

  15. THE LARGE MOMENTUM TRANSFER BEHAVIOUR OF MESON-PHOTON TRANSITION FORM FACTORS

    E-print Network

    P. Kroll

    1995-04-26

    It is reported on predictions for the $\\pi$-$\\gamma$ transition form factor obtained within a perturbative approach which includes transverse momentum effects and Sudakov corrections. The results clearly favor distribution amplitudes close to the asymptotic form, $\\sim x_1x_2$, and disfavor distribution amplitudes which are strongly concentrated in the end-point regions. Applications of that approach to the $\\eta$-$\\gamma$ and $\\eta^\\prime$-$\\gamma$ transition form factors are discussed as well.

  16. NUMERICAL COMPUTATION OF HEAT AND MOMENTUM TRANSFER IN TURBULENT FLOWS ALONG A PLATE USING LARGE TRANSVERSAL INTERVALS

    Microsoft Academic Search

    ANTONIO CAMPO; CARLOS A. SCHULER

    1990-01-01

    A hybrid computational method has been developed for the step-by-step calculation of both momentum and heat transfer in turbulent boundary layer flows along flat plates. Basically, the proposed procedure relies on the method of lines (MOL), which replaces a partial differential equation in two independent variables by an appropriate system of ordinary differential equations in one of these variables. This

  17. Ultrafast angular momentum transfer in multisublattice ferrimagnets.

    PubMed

    Bergeard, N; López-Flores, V; Halté, V; Hehn, M; Stamm, C; Pontius, N; Beaurepaire, E; Boeglin, C

    2014-01-01

    Femtosecond laser pulses can be used to induce ultrafast changes of the magnetization in magnetic materials. However, one of the unsolved questions is that of conservation of the total angular momentum during the ultrafast demagnetization. Here we report the ultrafast transfer of angular momentum during the first hundred femtoseconds in ferrimagnetic Co0.8Gd0.2 and Co0.74Tb0.26 films. Using time-resolved X-ray magnetic circular dichroism allowed for time-resolved determination of spin and orbital momenta for each element. We report an ultrafast quenching of the magnetocrystalline anisotropy and show that at early times the demagnetization in ferrimagnetic alloys is driven by the local transfer of angular momenta between the two exchange-coupled sublattices while the total angular momentum stays constant. In Co0.74Tb0.26 we have observed a transfer of the total angular momentum to an external bath, which is delayed by ~150?fs. PMID:24614016

  18. Exclusive Reactions at High Momentum Transfer

    NASA Astrophysics Data System (ADS)

    Radyushkin, Anatoly; Stoler, Paul

    2008-03-01

    Hard exclusive scattering at JLab / P. Kroll -- AdS/CFT and exclusive processes in QCD / S. J. Brodsky and G. F. de Téramond -- Hadron structure matters in collisions at high energy and momentum / A. W. Thomas -- Inclusive perspectives / P. Hoyer -- Fitting DVCS at NLO and beyond / K. Kumericki, D. Müller and K. Passek-Kumericki -- Spin-orbit correlations and single-spin asymmetries / M. Burkardt -- Electroproduction of soft pions at large momentum transfers / V. M. Braun, D. Yu. Ivanov and A. Peters -- Color transparency: 33 years and still running / M. Strikman -- Meson clouds and nucleon electromagnetic form factors / G. A. Miller -- Covariance, dynamics and symmetries, and hadron form factors / M. S. Bhagwat, I. C. Cloët and C. D. Roberts -- N to [symbol] electromagnetic and axial form factors in full QCD / C. Alexandrou -- Real and virtual compton scattering in perturbative QCD / C.-R. Ji and R. Thomson -- Deeply virtual compton scattering at Jefferson Lab / F. Sabatie -- DVCS at HERMES: recent results / F. Ellinghaus -- Deeply virtual compton scattering with CLAS / F. X. Girod -- Deeply virtual compton scattering off the neutron at JLab Hall A / M. Mazouz -- The future DVCS experiments in Hall A at JLab / J. Roche -- Deeply virtual compton scattering with CLAS12 / L. Elouadrhiri -- Quark helicity flip and the transverse spin dependence of inclusive DIS / A. Afanasev, M. Strikman and C. Weiss -- Deeply virtual pseudoscalar meson production / V. Kubarovsky and P. Stoler -- Exclusive p[symbol] electroproduction on the proton: GPDs or not GPDs? / M. Guidal and S. Morrow -- p[symbol] transverse target spin asymmetry at HERMES / A. Airapetian -- Electroproduction of ø(1020) mesons / J. P. Santoro and E. S. Smith -- Generalized parton distributions from hadronic observables / S. Ahmad ... [et al.] -- Imaging the proton via hard exclusive production in diffractive pp scattering / G. E. Hyde ... [et al.] -- Regge contributions to exclusive electro-production / A. P. Szczepaniak and J. T. Londergan -- High energy break-up of few-nucleon systems / M. Sargsian -- Photodisintegration of the deuteron, and [symbol]He / R. Gilman -- A review of the few-body form factors / G. G. Petratos -- Nucleon form factor measurements and interpretation / C. F. Perdrisat -- Implications of G[symbol](Q[symbol])/G[symbol](Q[symbol]) / S. Dubnicka and A. Z. Dubnickova -- High Q[symbol] large acceptance G[symbol]/G[symbol] measurements using polarization transfer / L. Pentchev, C. F. Perdrisat and B. Wojtsekhowski -- A precise measurement of the neutron magnetic form factor G[symbol] in the few-GeV[symbol] region / G. P. Gilfoyle et al. (the CLAS collaboration) -- Magnetic form factor of the neutron up to 8 (GeV/c)[symbol] / B. Quinn -- Timelike form factors / K. K. Seth -- Polarization phenomena in e[symbol]e[symbol] [symbol] pp¯ revisited / A. Z. Dubnickova and S. Dubnicka -- Light-cone sum rules for form factors of the N[symbol] transition at Q[symbol] = 0 / J. Rohrwild -- Exclusive electroproduction of [symbol] mesons / A. N. Villano (for the JLab E01-002 collaboration) -- Exclusive electroproduction of [symbol] mesons in the S[symbol](1535) resonance region at high momentum transfer / M. M. Dalton (for the JLab E01-002 collaboration) -- Two-photon exchange in electron-proton elastic scattering: theory update / A. V. Afanasev -- Two-photon exchange contributions to elastic ep scattering in the non-local field formalism / P. Jain, S. D. Joglekar and S. Mitra -- Beyond the born approximation: a precise comparison of positron-proton and electron-proton elastic scattering in CLAS / J. Lachniet et al. -- Meson form factors in the space-like region / D. Gaskell -- Pion-nucleon distribution amplitudes / A. Peters -- [symbol] scattering in the 1/N[symbol] expansion / H. J. Kwee -- [symbol] annihilations into quasi-two-body final states at 10.58 GeV / Kai Yi -- Transition distribution amplitudes / J. P. Lansberg, B. Pire and L. Szymanowski -- Novel QCD effects from initial and final state interactions / S. J. Brodsky -- Parton distributions and sp

  19. Polarisation Transfer in Proton Compton Scattering at High Momentum Transfer

    SciTech Connect

    David Hamilton

    2004-12-31

    The Jefferson Lab Hall A experiment E99-114 comprised a series of measurements to explore proton Compton scattering at high momentum transfer. For the first time, the polarisation transfer observables in the p (~ 0 ~ p) reaction were measured in the GeV energy range, where it is believed that quark-gluon degrees of freedom begin to dominate. The experiment utilised a circularly polarised photon beam incident on a liquid hydrogen target, with the scattered photon and recoil proton detected in a lead-glass calorimeter and a magnetic spectrometer, respectively.

  20. Electroproduction of hyperons at low momentum transfer

    NASA Astrophysics Data System (ADS)

    Acha, Armando R.

    A high resolution study of the H(e,e'K+)?,Sigma 0 reaction was performed at Hall A, TJNAF as part of the hypernuclear experiment E94-107. One important ingredient to the measurement of the hypernuclear cross section is the elementary cross section for production of hyperons, ? and Sigma0. This reaction was studied using a hydrogen (i.e. a proton) target. Data were taken at very low Q2 (˜0.07 (GeV/c) 2) and W˜2.2 GeV. Kaons were detected along the direction of q, the momentum transferred by the incident electron (thetaCM˜6°). In addition, there are few data available regarding electroproduction of hyperons at low Q2 and thetaCM and the available theoretical models differ significantly in this kinematical region of W. The measurement of the elementary cross section was performed by scaling the Monte Carlo cross section (MCEEP) with the experimental-to-simulated yield ratio. The Monte Carlo cross section includes an experimental fit and extrapolation from the existing data for electroproduction of hyperons. Moreover, the estimated transverse component of the electroproduction cross section of H(e,e'K+)? was compared to the different predictions of the theoretical models and exisiting data curves for photoproductions of hyperons. None of the models fully describe the cross-section results over the entire angular range. Furthermore, measurements of the Sigma 0/? production ratio were performed at theta CM˜6°, where data are not available. Finally, data for the measurements of the differential cross sections and the Sigma 0/? production were binned in Q2, W and thetaCM to understand the dependence on these variables. These results are not only a fundamental contribution to the hypernuclear spectroscopy studies but also an important experimental measurement to constrain existing theoretical models for the elementary reaction.

  1. Angular momentum transfer in optically induced photonic lattices

    SciTech Connect

    Petrovic, Milan S.; Jovic, Dragana M.; Prvanovic, Slobodan [Institute of Physics, P.O. Box 57, 11001 Belgrade (Serbia); Belic, Milivoj R. [Institute of Physics, P.O. Box 57, 11001 Belgrade (Serbia); Texas A and M University at Qatar, P.O. Box 5825, Doha (Qatar)

    2007-08-15

    The transfer of orbital angular momentum from vortex beams to optically induced photonic lattices is demonstrated. It is found that the sum of the angular momenta of interacting incoherent counterpropagating (CP) beams is not conserved, whereas their difference is. The sum of angular momenta of copropagating (CO) interacting beams is strictly conserved. It is also found that the transfer of angular momentum in CP interacting beams is minimal, amounting to a few percent, whereas the transfer in CO interacting beams is substantial, amounting to tens of percent. In fixed lattices, for both CP and CO beams, angular momentum is never conserved.

  2. Optical momentum transfer to macroscopic media

    E-print Network

    Kemp, Brandon Alden, 1975-

    2007-01-01

    Persistent conflicts over the momentum of light in media has led researchers to apply an alternate approach to predicting the electromagnetic force on material. Direct application of the Lorentz force to media allows for ...

  3. Mass and momentum transfer enhancement due to electrogenerated gas bubbles

    Microsoft Academic Search

    F. Giron; G. Valentin; M. Lebouche; A. Storck

    1985-01-01

    The effect of electrogenerated gas bubbles with simultaneous bulk liquid flow on the mass and momentum transfer at a wall of an electrolytic cell is experimentally determined. The local mass transfer coefficient and electrolyte shear stress are obtained using two types of microelectrodes imbedded in the channel wall. The influence of the most important parameters (electrolyte velocity, position along the

  4. Large momentum transfer neutron pickup with the (. pi. /sup +/,p) and (p,d) reactions. [90 and 180 MeV, 800 MeV

    SciTech Connect

    Smith, G.R.

    1980-01-01

    The (p,d) reaction was studied for the first time at 800 MeV on seven targets ranging from /sup 7/Li to /sup 40/Ca. The experimental resolution (approx. 400 keV) attained was sufficient to observe many discrete levels in each of the residual nuclei. A modified version of the one-nucleon model successfully describes the magnitude and angular dependence of almost all of the transitions observed. A specific counter example to the two-nucleon model of the reaction mechanism is suggested. The calculations are also sensitive to the neutron single-particle wave function, in accordance with the expectation that the high-momentum components of this wave function are probed at higher bombarding energies. States that have never been seen before were strongly populated in the high excitation region (up to 25 MeV) of some of the residual nuclei. The relative intensities of the other levels observed suggest that coupled-channels mechanisms play an important role for some of these states. Explicit calculations were performed to confirm this for several examples. The first high-resolution measurements of the (..pi../sup +/,p) reaction were also performed on /sup 6/Li, /sup 7/Li, /sup 12/C, and /sup 13/C at pion bombarding energies on and off the pion-nucleon resonance. Calculations employing a one-nucleon model of the reaction mechanism similar to the model successfully used for the (p,d) reaction are unable to account for transitions in the (..pi../sup +/,p) reaction. It is, however, unclear whether this failure is due to a fundamental inadequacy of the model or improper treatment of details in the calculations. A striking similarity was observed in the spectra of the (..pi../sup +/,p) and 800-MeV (p,d) reactions on the same target; this result implies a similar mechanism for the two reactions. 120 references, 97 figures, 15 tables.

  5. Spacecraft momentum management procedures. [large space telescope

    NASA Technical Reports Server (NTRS)

    Chen, L. C.; Davenport, P. B.; Sturch, C. R.

    1980-01-01

    Techniques appropriate for implementation onboard the space telescope and other spacecraft to manage the accumulation of momentum in reaction wheel control systems using magnetic torquing coils are described. Generalized analytical equations are derived for momentum control laws that command the magnetic torquers. These control laws naturally fall into two main categories according to the methods used for updating the magnetic dipole command: closed loop, in which the update is based on current measurements to achieve a desired torque instantaneously, and open-loop, in which the update is based on predicted information to achieve a desired momentum at the end of a period of time. Physical interpretations of control laws in general and of the Space Telescope cross product and minimum energy control laws in particular are presented, and their merits and drawbacks are discussed. A technique for retaining the advantages of both the open-loop and the closed-loop control laws is introduced. Simulation results are presented to compare the performance of these control laws in the Space Telescope environment.

  6. Orbital angular momentum transfer in helical Mathieu beams

    Microsoft Academic Search

    Carlos López-Mariscal; Julio C. Gutiérrez-Vega; Graham Milne; Kishan Dholakia

    2006-01-01

    We observe the transfer of orbital angular momentum to trapped particles in the azimuthally asymmetric transverse intensity distribution of a helical Mathieu beam. The average rotation rate, instantaneous angular displacement and terminal velocity of the trapped particles are measured experimentally. The angular dependence of these parameters is found to be in good agreement with the variation of the optical gradient

  7. Accurate momentum transfer cross section for the attractive Yukawa potential

    SciTech Connect

    Khrapak, S. A., E-mail: Sergey.Khrapak@dlr.de [Forschungsgruppe Komplexe Plasmen, Deutsches Zentrum für Luft- und Raumfahrt, Oberpfaffenhofen (Germany)

    2014-04-15

    Accurate expression for the momentum transfer cross section for the attractive Yukawa potential is proposed. This simple analytic expression agrees with the numerical results better than to within ±2% in the regime relevant for ion-particle collisions in complex (dusty) plasmas.

  8. Momentum Transfer in a Spinning Fuel Tank Filled with Xenon

    NASA Technical Reports Server (NTRS)

    Peugeot, John W.; Dorney, Daniel J.

    2006-01-01

    Transient spin-up and spin-down flows inside of spacecraft fuel tanks need to be analyzed in order to properly design spacecraft control systems. Knowledge of the characteristics of angular momentum transfer to and from the fuel is used to size the de-spin mechanism that places the spacecraft in a controllable in-orbit state. In previous studies, several analytical models of the spin-up process were developed. However, none have accurately predicted all of the flow dynamics. Several studies have also been conducted using Navier-Stokes based methods. These approaches have been much more successful at simulating the dynamic processes in a cylindrical container, but have not addressed the issue of momentum transfer. In the current study, the spin-up and spin-down of a fuel tank filled with gaseous xenon has been investigated using a three-dimensional unsteady Navier-Stokes code. Primary interests have been concentrated on the spin-up/spin-down time constants and the initial torque imparted on the system. Additional focus was given to the relationship between the dominant flow dynamics and the trends in momentum transfer. Through the simulation of both a cylindrical and a spherical tank, it was revealed that the transfer of angular momentum is nonlinear at early times and tends toward a linear pattern at later times. Further investigation suggests that the nonlinear spin up is controlled by the turbulent transport of momentum, while the linear phase is controlled by a Coriolis driven (Ekman) flow along the outer wall. These results indicate that the spinup and spin-down processes occur more quickly in tanks with curved surfaces than those with defined top, bottom, and side walls. The results also provide insights for the design of spacecraft de-spin mechanisms.

  9. Mathematical models of momentum transfer in the boundary layer

    NASA Astrophysics Data System (ADS)

    Laptev, A. G.; Farakhov, T. M.

    2013-05-01

    Consideration has been given to the processes of momentum transfer in the laminar and turbulent boundary layers on a plate and in a tube. Original models for calculation of the tangential stress, friction factors, boundary-layer thickness, and coefficients of momentum transfer in the boundary layers on a plate and in a tube have been obtained under different conditions of motion of the gas medium. Examples of calculation of the indicated characteristics have been given; the results obtained have been compared to the existing experimental data. The obtained equations and methods of determination of the characteristics of the boundary layer can be used in designing industrial heat- and mass-exchange apparatuses of various structures and other equipment.

  10. Polarization Transfer in Proton Compton Scattering at High Momentum Transfer

    SciTech Connect

    Hamilton, D.J.; Annand, J.R.M. [University of Glasgow, Glasgow G12 8QQ (United Kingdom); Mamyan, V.H. [Yerevan Physics Institute, Yerevan 375036 (Armenia); Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Aniol, K.A.; Margaziotis, D.J. [California State University Los Angeles, Los Angeles, California 90032 (United States); Bertin, P.Y.; Camsonne, A.; Laveissiere, G. [Universite Blaise Pascal/IN2P3, F-63177 Aubiere (France); Bimbot, L. [IPN, Orsay B.P. no. 1 F-91406, Orsay (France); Bosted, P.; Paschke, K. [University of Massachusetts, Amherst, Massachusetts 01003 (United States); Calarco, J.R. [University of New Hampshire, Durham, New Hampshire 03824 (United States); Chang, G.C.; Horn, T.; Savvinov, N. [University of Maryland, College Park, Maryland 20742 (United States); Chang, T.-H.; Danagoulian, A.; Nathan, A.M.; Roedelbronn, M. [University of Illinois, Urbana-Champaign, Illinois 61801 (United States); Chen, J.-P. [Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)] [and others

    2005-06-24

    Compton scattering from the proton was investigated at s=6.9 GeV{sup 2} and t=-4.0 GeV{sup 2} via polarization transfer from circularly polarized incident photons. The longitudinal and transverse components of the recoil proton polarization were measured. The results are in disagreement with a prediction of perturbative QCD based on a two-gluon exchange mechanism, but agree well with a prediction based on a reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton.

  11. Angular Momentum Transfer in Dark Matter Halos: Erasing the Cusp

    E-print Network

    Chiara Tonini; Andrea Lapi; Paolo Salucci

    2006-06-05

    We propose that angular momentum transfer from the baryons to the Dark Matter (DM) during the early stages of galaxy formation can flatten the halo inner density profile and modify the halo dynamics. We compute the phase-space distribution function of DM halos, that corresponds to the density and anisotropy profiles obtained from N-body simulations in the concordance cosmology. We then describe an injection of angular momentum into the halo by modifying the distribution function, and show that the system evolves into a new equilibrium configuration; the latter features a constant central density and a tangentially-dominated anisotropy profile in the inner regions, while the structure is nearly unchanged beyond 10% of the virial radius. Then we propose a toy model to account for such a halo evolution, based on the angular momentum exchange due to dynamical friction; at the epoch of galaxy formation this is efficiently exerted by the DM onto the gas clouds spiralling down the potential well. The comparison between the angular momentum profile gained by the halo through dynamical friction and that provided by the perturbed distribution function reveals a surprising similarity, hinting at the reliability of the process.

  12. Absolute momentum transfer in gas-surface scattering

    NASA Astrophysics Data System (ADS)

    Cook, Steven R.; Hoffbauer, Mark A.

    1997-04-01

    Two new parameters called the reduced force coefficients are introduced that eliminate the singularity problems associated with the momentum accommodation coefficients and completely describe the macroscopic average momentum transfer to a surface by an incident gas. In addition, the reduced force coefficients can be used to determine the flux-weighted average velocity and translational energy of molecules scattered from a surface, and can be used to approximate the energy accommodation coefficient for many gas-surface interactions. The reduced force coefficients for molecular beams of H2 and N2 incident upon SiO2-coated Kapton and Z-93-coated aluminum were obtained using a specialized torsion balance to measure the magnitudes and directions of the forces exerted on the surfaces by the molecular beams.

  13. Understanding quark flow in high momentum transfer exclusive reactions

    SciTech Connect

    White, C.; Courant, H.; Fang, G.; Heller, K.; Johns, K.; Marshak, M.; Shupe, M. (Minnesota Univ., Minneapolis, MN (USA)); Appel, R.; Barton, D.; Bunce, G.; Carroll, A.; Gushue, S.; Kmit, M.; Lowenstein, D.; Makdisi, Y. (Brookhaven National Lab., Upton, NY (USA)); Ma, X.; Russell, J. (Southeastern Massachusetts Univ., North Dartmouth, MA (USA)); Heppelmann, S. (Pennsylvania State Univ., University Park, PA (USA

    1990-01-01

    A 5.9 GeV/c secondary beam of pions, kaons, and protons directed into a liquid hydrogen target has been used to study high momentum transfer exclusive reactions of the form A + B {yields} C + D. The high sensitivity of this experiment has allowed the differential cross section for 19 two body exclusive reactions to be measured around 90 degrees in the center of mass frame. These high statistic measurements confirm the conclusion of an earlier 10 GeV/c experiment which found that the relative magnitudes of the cross sections are consistent with the dominance of the quark interchange diagram. 6 refs., 4 fig., 1 tab.

  14. Angular momentum transfer in Dark Matter halos: erasing the cusp

    E-print Network

    Tonini, C; Salucci, P; Tonini, Chiara; Lapi, Andrea; Salucci, Paolo

    2006-01-01

    We propose that angular momentum transfer from the baryons to the Dark Matter (DM) during the early stages of galaxy formation can flatten the halo inner density profile and modify the halo dynamics. We compute the phase-space distribution function of DM halos, that corresponds to the density and anisotropy profiles obtained from N-body simulations in the concordance cosmology. We then describe an injection of angular momentum into the halo by modifying the distribution function, and show that the system evolves into a new equilibrium configuration; the latter features a constant central density and a tangentially-dominated anisotropy profile in the inner regions, while the structure is nearly unchanged beyond 10% of the virial radius. Then we propose a toy model to account for such a halo evolution, based on the angular momentum exchange due to dynamical friction; at the epoch of galaxy formation this is efficiently exerted by the DM onto the gas clouds spiralling down the potential well. The comparison betw...

  15. Three-dimensional simulations of air flow and momentum transfer in partially harvested forests

    Microsoft Academic Search

    Terry L. Clark; Stephen J. Mitchell

    2007-01-01

    In order to predict wind loading on trees (canopy height h) in partially harvested forests, it is necessary to characterize air flow and momentum transfer in progressively more complex\\u000a patterns where groups of trees (or aggregates) are retained. In this study, we used large-eddy simulation to explore the effects\\u000a of aggregate size, inter-aggregate spacing, and the ratio between the aggregate

  16. Hydrophobicity, heat transfer, and momentum transfer at hard and soft aqueous interfaces

    NASA Astrophysics Data System (ADS)

    Acharya, Hari

    Advancements in science and technology increasingly involve systems operating at the nanoscale. Interfaces are often present in these systems. Nanoscopic interfaces are ubiquitous in biological systems, nanofluidic devices, and integrated circuits. Properties at the interface may be quite different from the bulk, and in fact a true bulk may not be present in these systems. At the nanoscale the ratio of interface to volume is large, and the interface may have the dominant role in determining system behavior. Interfacial characteristics and their connection to interfacial properties are the focus of my thesis. Using molecular simulations of model interfaces we characterize how properties like chemistry, composition, and topography affect such phenomena such as hydrophobicity, heat transfer, and momentum transport at the nanoscale. An interface is defined simply as where two materials meet and a change in some structure or order parameter is observed. In aqueous systems, the type studied here, these changes are relatively sharp and occur within a distance of nanometers. Water molecules near the interface are expected to display sensitivity to the underlying surface. Indeed, water near a hydrophobic surface is more deformable and has greater fluctuations. The hydrophobicity of chemically heterogeneous surfaces and proteins are characterized using these nanoscopic measures. We find the effect of mixing hydrophobic and hydrophobic head group chemistries is asymmetric, i.e., it is easier to make a hydrophobic surface hydrophilic than the reverse. The role of hydrogen bonding in hydrophobic and ion hydration is also characterized using a short range water model. Hydrophobic and ion hydration are reasonably captured with the short range water model. These studies show the importance of chemical composition and local hydrogen bonding in determining surface hydrophobicity. Interfaces also lead to anomalous behavior in heat and momentum transport. Interfaces disrupt local structure and create boundary resistances that manifest in temperature discontinuities and interfacial slip. We explore the effects of chemical heterogeneity, nanoscale surface roughness, and directionality on thermal conductance across model solid-water interfaces. Interfacial conductance is directly influenced by the coupling strength or wettability of the surface. For chemically mixed surfaces, interfacial conductance does not precisely match with wettability. Surface roughness in general enhances conductance, but the improvement cannot be completely attributed to increased solvent accessible surfaced area. Momentum transport displays similar discontinuities at aqueous interfaces. These effects can be reduced through the use of osmolytes. Collectively this work highlights the influence of interfaces on heat and momentum transport. Insights are provided for modifying interfacial behavior and altering the property of interest.

  17. An optical model description of momentum transfer in heavy ion collisions

    NASA Technical Reports Server (NTRS)

    Khan, F.; Khandelwal, G. S.; Townsend, Lawrence W.; Wilson, J. W.; Norbury, John W.

    1989-01-01

    An optical model description of momentum transfer in relativistic heavy ion collisions, based upon composite particle multiple scattering theory, is presented. The imaginary component of the complex momentum transfer, which comes from the absorptive part of the optical potential, is identified as the longitudinal momentum downshift of the projectile. Predictions of fragment momentum distribution observables are made and compared with experimental data. Use of the model as a tool for estimating collision impact parameters is discussed.

  18. Optical model description of momentum transfer in relativistic heavy ion collisions

    NASA Technical Reports Server (NTRS)

    Khan, F.; Khandelwal, G. S.; Townsend, L. W.; Wilson, J. W.; Norbury, J. W.

    1991-01-01

    An optical model description of momentum transfer in relativistic heavy ion collisions, based upon composite particle multiple scattering theory, is presented. The imaginary component of the complex momentum transfer, which comes from the absorptive part of the optical potential, is identified as the longitudinal momentum downshift of the projectile. Predictions of fragment momentum distribution observables are made and compared with experimental data. Use of the model as a tool for estimating collision impact parameters is discussed.

  19. Pion form factor at spacelike momentum transfers from local-duality QCD sum rule

    NASA Astrophysics Data System (ADS)

    Braguta, Victor; Lucha, Wolfgang; Melikhov, Dmitri

    2008-04-01

    We study the pion form factor in a broad range of spacelike momentum transfers within the local-duality version of QCD sum rules. We make use of the recently calculated two-loop double spectral density of the < AVA > correlator including O (1) and O (?s) terms, which allows us to give predictions for the pion form factor and to study the interplay between the nonperturbative and perturbative contributions to the pion form factor without any reference to the pion distribution amplitude. Our results demonstrate the dominance of the nonperturbative contribution to the form factor up to relatively large values of the momentum transfer: namely, the nonperturbative O (1) term, which provides the 1 /Q4 power correction, gives more than half of the pion form factor in the region Q2 ? 20GeV2.

  20. Inverse cascades sustained by the transfer rate of angular momentum in a 3D turbulent flow.

    PubMed

    López-Caballero, Miguel; Burguete, Javier

    2013-03-22

    The existence of energy cascades as signatures of conserved magnitudes is one of the universal characteristics of turbulent flows. In homogeneous 3D turbulence, the energy conservation produces a direct cascade from large to small scales, although in 2D, it produces an inverse cascade pointing towards small wave numbers. In this Letter, we present the first evidence of an inverse cascade in a fully developed 3D experimental turbulent flow where the conserved magnitude is the angular momentum. Two counterrotating flows collide in a central region where very large fluctuations are produced, generating a turbulent drag that transfers the external torque between different fluid layers. PMID:25166809

  1. ANGULAR MOMENTUM TRANSFER IN VELA-LIKE PULSAR GLITCHES

    SciTech Connect

    Pizzochero, Pierre M., E-mail: pierre.pizzochero@mi.infn.it [Dipartimento di Fisica, Universita degli Studi di Milano, and Istituto Nazionale di Fisica Nucleare, sezione di Milano, Via Celoria 16, 20133 Milano (Italy)

    2011-12-10

    The angular momentum transfer associated with Vela-like glitches has never been calculated directly within a realistic scenario for the storage and release of superfluid vorticity; therefore, the explanation of giant glitches in terms of vortices has not yet been tested against observations. We present the first physically reasonable model, both at the microscopic and macroscopic level (spherical geometry, n = 1 polytropic density profile, density-dependent pinning forces compatible with vortex rigidity), to determine where in the star the vorticity is pinned, how much of it is pinned, and for how long. For standard neutron star parameters (M = 1.4 M{sub Sun }, R{sub s} = 10 km, {Omega}-dot = {Omega}-dot{sub Vela} = -10{sup -10} Hz s{sup -1}), we find that maximum pinning forces of order f{sub m} Almost-Equal-To 10{sup 15} dyn cm{sup -1} can accumulate {Delta}L{sub gl} Almost-Equal-To 10{sup 40} erg s of superfluid angular momentum, and release it to the crust at intervals {Delta}t{sub gl} Almost-Equal-To 3 years. This estimate of {Delta}L{sub gl} is one order of magnitude smaller than that implied indirectly by current models for post-glitch recovery, where the core and inner-crust vortices are taken as physically disconnected; yet, it successfully yields the magnitudes observed in recent Vela glitches for both jump parameters, {Delta}{Omega}{sub gl} and {Delta}{Omega}-dot{sub gl}, provided one assumes that only a small fraction (<10%) of the total star vorticity is coupled to the crust on the short timescale of a glitch. This is reasonable in our approach, where no layer of normal matter exists between the core and the inner-crust, as indicated by existing microscopic calculation. The new scenario presented here is nonetheless compatible with current post-glitch models.

  2. Quantum interference by coherence transfer from spin to orbital angular momentum of photons

    E-print Network

    Marrucci, Lorenzo

    Quantum interference by coherence transfer from spin to orbital angular momentum of photons Nagali spin to orbital angular momentum of photons Nagali E.a, Sciarrino F.a, Sansoni L.a, De Martini F The orbital angular momentum carried by single photons reprents a promising resource in the quantum informa

  3. Recoil Polarization Measurements of the Proton Electromagnetic Form Factor Ratio to High Momentum Transfer

    SciTech Connect

    Andrew Puckett

    2010-02-01

    The electromagnetic form factors of the nucleon characterize the effect of its internal structure on its response to an electromagnetic probe as studied in elastic electronnucleon scattering. These form factors are functions of the squared four-momentum transfer Q2 between the electron and the proton. The two main classes of observables of this reaction are the scattering cross section and polarization asymmetries, both of which are sensitive to the form factors in different ways. When considering large f momentum transfers, double-polarization observables offer superior sensitivity to the electric form factor. This thesis reports the results of a new measurement of the ratio of the electric and magnetic form factors of the proton at high momentum transfer using the recoil polarization technique. A polarized electron beam was scattered from a liquid hydrogen target, transferring polarization to the recoiling protons. These protons were detected in a magnetic spectrometer which was used to reconstruct their kinematics, including their scattering angles and momenta, and the position of the interaction vertex. A proton polarimeter measured the polarization of the recoiling protons by measuring the azimuthal asymmetry in the angular distribution of protons scattered in CH2 analyzers. The scattered electron was detected in a large acceptance electromagnetic calorimeter in order to suppress inelastic backgrounds. The measured ratio of the transverse and longitudinal polarization components of the scattered proton is directly proportional to the ratio of form factors GpE=GpM. The measurements reported in this thesis took place at Q2 =5.2, 6.7, and 8.5 GeV2, and represent the most accurate measurements of GpE in this Q2 region to date.

  4. Optical orbital angular momentum conservation during the transfer process from plasmonic vortex lens to light.

    PubMed

    Yu, Haohai; Zhang, Huaijin; Wang, Yicheng; Han, Shuo; Yang, Haifang; Xu, Xiangang; Wang, Zhengping; Petrov, V; Wang, Jiyang

    2013-01-01

    We demonstrate the optical orbital angular momentum conservation during the transfer process from subwavelength plasmonic vortex lens (PVLs) to light and the generating process of surface plasmon polaritons (SPPs). Illuminating plasmonic vortex lenses with beams carrying optical orbital angular momentum, the SP vortices with orbital angular momentum were generated and inherit the optical angular momentum of light beams and PVLs. The angular momentum of twisting SP electromagnetic field is tunable by the twisted metal/dielectric interfaces of PVLs and angular momentum of illuminating singular light. This work may open the door for several possible applications of SP vortices in subwavelength region. PMID:24217130

  5. Momentum transfer cross sections for the heavy noble gases

    NASA Astrophysics Data System (ADS)

    Stauffer, A. D.; McEachran, R. P.

    2012-10-01

    We have used our relativistic optical potential method [1] to calculate the momentum transfer cross sections for Ar, Kr and Xe from threshold to 1000 eV. The target ground state as well as the open excited and ionization channels used in the optical potential have been calculated using the MCDF program [2]. We have included 17 excitation channels for Ar, 26 for Kr and 15 for Xe. In the ionization channels, ionization of the outer p, s and d shells were included for Kr and Xe while for Ar all electrons were allowed to be ionized. Comparisons with previous calculations and experimental measurements will be included. We also include analytic fits to our cross sections to aid in plasma modelling studies. [4pt] [1] S. Chen, R. P. McEachran and A. D. Stauffer, J. Phys. B 41 025201 (2008) [0pt] [2] I. P. Grant, B. J. McKenzie, P. H. Norrington, D. F. Mayers and N. C. Pyper, Comput. Phys. Commun. 21 207 (1980)

  6. Experimental Observations of Exclusive Hadronic Interactions at High Momentum Transfer

    NASA Astrophysics Data System (ADS)

    Blazey, Gerald Charles

    An experiment was conducted at the Brookhaven National Laboratory alternating gradient syncrotron in order to measure the production rates of exclusive reactions at high momentum transfer. The reaction products of a negative pion beam scattered off a liquid hydrogen target were monitored with two tracking arms; one consisting of a spectrometer magnet and multi-wire chambers, the other including only wire chambers. The cross-sections near ninety degrees in the center of mass for the reaction (pi)(' -)p > (pi)('-)p were 1.7 and 0.2 (eta)b/Gev('2) at beam energies of 9.93 and 13.45 Gev/c, respectively. The ninety degree cross-sections for the reaction (pi)('-)p > (rho)(' -)p were of similar magnitude. For both beam energies, the decay distribution of the (rho) included azimuthal structure. The energy dependence of the cross-sections and the decay distributions of the (rho) are in general disagreement with first order perturbative QCD.

  7. Spin absorption, windmill, and magneto-optic effects in optical angular momentum transfer

    SciTech Connect

    Normanno, Davide; Capitanio, Marco; Pavone, Francesco Saverio [LENS, Universita degli Studi di Firenze, Via N. Carrara 1, I-50019 Sesto Fiorentino, FI (Italy); INFM sez. Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, FI (Italy)

    2004-11-01

    Laser beams exert torque on microparticles through very different physical mechanisms. In this paper, optical angular momentum transferred by laser light to a trapped absorbing superparamagnetic microsphere has been studied, distinguishing between different contributions. We have found the main contribution to the torque arising from the transfer of the spin angular momentum carried by absorbed laser light. Detailed polarization status contribution of the laser light to the momentum transfer has been then analyzed. A general method to separate and quantify contributions to the optical angular momentum transferred has been developed. We have thus quantified contributions due to radiation pressure, through an effect similar to the wind on a windmill, and contributions arising from magneto-optic effects.

  8. Polarization radiation of vortex electrons with large orbital angular momentum

    E-print Network

    Ivanov, Igor P

    2013-01-01

    Vortex electrons, i.e. freely propagating electrons whose wavefunction has helical wavefronts, could emerge as a novel tool for the physics of electromagnetic (EM) radiation. They carry non-zero intrinsic orbital angular momentum (OAM) $\\ell$ and, for $\\ell \\gg 1$, a large OAM-induced magnetic moment, $\\mu \\approx \\ell \\mu_B$ ($\\mu_B$ is the Bohr magneton), which affects the radiation of EM waves. Here, we consider in detail its influence on two forms of polarization radiation, namely on Cherenkov and transition radiation. Due to large $\\ell$, we can neglect quantum or spin-induced effects, which are of order $\\hbar \\omega/E_e \\ll 1$, but retain the magnetic moment contribution $\\ell \\hbar \\omega/E_e \\lesssim 1$, which makes the quasiclassical approach to polarization radiation applicable. We discuss magnetic moment contribution to polarization radiation, which has never been experimentally observed, and study how its visibility depends on kinematical parameters and permittivity of the medium. In particular, ...

  9. Universal characteristics of transverse momentum transfer in intermediate energy heavy ion collisions

    NASA Technical Reports Server (NTRS)

    Khan, F.; Townsend, L. W.; Tripathi, R. K.; Cucinotta, F. A.

    1993-01-01

    A microscopic optical model formalism for estimating momentum transfer in intermediate energy heavy ion collisions predicts universal behavior of the transverse component. In particular, for symmetric systems heavier than niobium, it appears that values of P(perpendicular)/A are independent of the mass and charge of the colliding nuclei and vary only with impact parameter and incident beam energy. This suggests that momentum transfer per nucleon saturates to some limiting value with increasing mass.

  10. Transfer of orbital angular momentum through sub-wavelength waveguides.

    PubMed

    Wang, Yanqin; Ma, Xiaoliang; Pu, Mingbo; Li, Xiong; Huang, Cheng; Pan, Wenbo; Zhao, Bo; Cui, Jianhua; Luo, Xiangang

    2015-02-01

    Data capacity of optical communication is achieving its limit owing to the non-linear effect of optical fiber. As an effective alternative, light carrying orbital angular momentum can greatly increase the capacity for its unprecedented degree of freedom. We demonstrate the propagation of orbital angular momentum with topological charge of 1 and 2 in plasmonic circular waveguide with sub-wavelength diameter with little propagation loss of 2.73 dB/?m, which has never been observed in optical fibers with sub-wavelength diameter. We also confirm that lights carrying orbital angular momentum can be maintained in sharp bended sub-wavelength waveguide. This plasmonic waveguide may serve as a key component in on-chip systems involving OAM. PMID:25836146

  11. Nuclear fragmentation energy and momentum transfer distributions in relativistic heavy-ion collisions

    NASA Technical Reports Server (NTRS)

    Khandelwal, Govind S.; Khan, Ferdous

    1989-01-01

    An optical model description of energy and momentum transfer in relativistic heavy-ion collisions, based upon composite particle multiple scattering theory, is presented. Transverse and longitudinal momentum transfers to the projectile are shown to arise from the real and absorptive part of the optical potential, respectively. Comparisons of fragment momentum distribution observables with experiments are made and trends outlined based on our knowledge of the underlying nucleon-nucleon interaction. Corrections to the above calculations are discussed. Finally, use of the model as a tool for estimating collision impact parameters is indicated.

  12. On angular momentum transfer in binary systems. [stellar orbital period change

    NASA Technical Reports Server (NTRS)

    Wilson, R. E.; Stothers, R.

    1975-01-01

    The maximum limit for the conversion of orbital angular momentum into rotational angular momentum of the mass-gaining component in a close binary system is derived. It is shown that this conversion process does not seriously affect the rate of orbital period change and can be neglected in computing the mass transfer rate. Integration of this limit over the entire accretion process results in a value for the maximum accumulated rotational angular momentum that is 3 to 4 times larger than that implied by the observed underluminosity of stars in such systems as Mu(1) Sco, V Pup, SX Aur, and V356 Sgr. It is suggested that shell stars and emission-line stars in binary systems may be produced when the core angular momentum is transferred into an envelope having a rotational angular momentum close to the maximum limit.-

  13. Polarization radiation of vortex electrons with large orbital angular momentum

    NASA Astrophysics Data System (ADS)

    Ivanov, Igor P.; Karlovets, Dmitry V.

    2013-10-01

    Vortex electrons—freely propagating electrons whose wave functions have helical wave fronts—could become a novel tool in the physics of electromagnetic radiation. They carry a nonzero intrinsic orbital angular momentum (OAM) ? with respect to the propagation axis and, for ??1, a large OAM-induced magnetic moment ????B (?B is the Bohr magneton), which influences the radiation of electromagnetic waves. Here, we consider in detail the OAM-induced effects caused by such electrons in two forms of polarization radiation, namely, in Cherenkov radiation and transition radiation. Thanks to the large ?, we can neglect quantum or spin-induced effects, which are of the order of ??/Ee?1, but retain the magnetic moment contribution ???/Ee?1, which makes the quasiclassical approach to polarization radiation applicable. We discuss the magnetic moment contribution to polarization radiation, which has never been experimentally observed, and study how its visibility depends on the kinematical parameters and the medium permittivity. In particular, it is shown that this contribution can, in principle, be detected in azimuthally nonsymmetrical problems, for example when vortex electrons obliquely cross a metallic screen (transition radiation) or move near it (diffraction radiation). We predict a left-right angular asymmetry of the transition radiation (in the plane where the charge radiation distributions would stay symmetric), which appears due to an effective interference between the charge radiation field and the magnetic moment contribution. Numerical values of this asymmetry for vortex electrons with Ee=300 keV and ?=100-1000 are 0.1%-1%, and we argue that this effect could be detected with existing technology. The finite conductivity of the target and frequency dispersion play crucial roles in these predictions.

  14. Polarization radiation of vortex electrons with large orbital angular momentum

    E-print Network

    Igor P. Ivanov; Dmitry V. Karlovets

    2013-07-20

    Vortex electrons, - freely propagating electrons whose wavefunction has helical wavefronts, - could become a novel tool in the physics of electromagnetic radiation. They carry a non-zero intrinsic orbital angular momentum (OAM) $\\ell$ with respect to the propagation axis and, for \\ell \\gg 1, a large OAM-induced magnetic moment, \\mu ~ \\ell \\mu_B (\\mu_B is the Bohr magneton), which influences the radiation of electromagnetic waves. Here, we consider in detail the OAM-induced effects by such electrons in two forms of polarization radiation, namely in Cherenkov radiation and transition radiation. Thanks to the large \\ell, we can neglect quantum or spin-induced effects, which are of the order of \\hbar \\omega/E_e \\ll 1, but retain the magnetic moment contribution \\ell \\hbar \\omega/E_e \\lesssim 1, which makes the quasiclassical approach to polarization radiation applicable. We discuss the magnetic moment contribution to polarization radiation, which has never been experimentally observed, and study how its visibility depends on the kinematical parameters and the medium permittivity. In particular, it is shown that this contribution can, in principle, be detected in azimuthally non-symmetrical problems, for example when vortex electrons obliquely cross a metallic screen (transition radiation) or move nearby it (diffraction radiation). We predict a left-right angular asymmetry of the transition radiation (in the plane where the charge radiation distributions would stay symmetric), which appears due to an effective interference between the charge radiation field and the magnetic moment one. Numerical values of this asymmetry for vortex electrons with E_e = 300keV and \\ell = O(100-1000) are O(0.1-1%), and we argue that this effect could be detected with existing technology. The finite conductivity of the target and frequency dispersion play the crucial roles in these predictions.

  15. Effect of Increased Academic Momentum on Transfer Rates: An Application of the Generalized Propensity Score

    ERIC Educational Resources Information Center

    Doyle, William R.

    2011-01-01

    Several studies have reported a positive impact of increased academic momentum on transfer from community colleges to four-year institutions. This result may be due to selection bias. Using data from the Beginning Postsecondary Students dataset, I test whether taking more credits in the first year has an impact on transfer rates among bachelor's…

  16. Electron Transfer for Large Molecules through Delocalization

    SciTech Connect

    Neuhauser, D.; Reslan, R.; Hernandez, S.; Arnsen, C.; Lopata, K.; Govind, N.; Gao, Y.; Tolbert, S.; Schwartz, B.; Rubin, Y.; Nardes, A.; Kopidakis, N.

    2012-01-01

    Electron transfer for large molecules lies in between a Marcus-Theory two-state transfer and a Landauer description. We discuss a delocalization formalism which,through the introduction of artificial electric fields which emulate bulk dipole fields, allows calculation between a pair of identical molecules (A+A- (R)A-+A) with several open states. Dynamical electron polarization effects can be inserted with TDDFT and are crucial for large separations.

  17. The importance of momentum transfer in collision-induced breakups in low Earth orbit

    NASA Technical Reports Server (NTRS)

    Reynolds, Robert C.; Lillie, Brian J.

    1991-01-01

    Although there is adequate information on larger objects in low Earth orbit, specifically those objects larger than about 10 cm in diameter, there is little direct information on objects from this size down to 1 mm. Yet, this is the sized regime where objects acting as projectiles represent the ability to seriously damage or destroy a functioning spacecraft if they collide with it. The observed consequences of known collisional breakups in orbit indicates no significant momentum transfer in the resulting debris cloud. The position taken in this paper is that this is an observational selection effect: what is seen in these events is an explosion-like breakup of the target structure arising from shock waves introduced into the structure by the collision, but one that occurs significantly after the collision processes are completed; the collision cloud, in which there is momentum transfer, consists of small, unobserved fragments. Preliminary computations of the contribution of one known collisional breakup, Solwind at 500 km in 1985, and Cosmos 1275 in 1981, assume no momentum transfer on breakup and indicate that these two events are the dominant contributors to the current millimeter and centimeter population. A different story would emerge if momentum transfer was taken into account. The topics covered include: (1) observation of on-orbit collisional breakups; (2) a model for momentum transfer; and (3) velocity space representation of breakup clouds.

  18. Synchronized molecular dynamics simulation via macroscopic heat and momentum transfer: an application to polymer lubrication

    E-print Network

    Shugo Yasuda; Ryoichi Yamamoto

    2014-07-16

    The synchronized molecular dynamics simulation via macroscopic heat and momentum transfer is proposed for the non-isothermal flow behaviors of complex fluids. In this method, the molecular dynamics simulations are assigned to small fluid elements to calculate the local stresses and temperatures and are synchronized at certain time intervals to satisfy the macroscopic heat- and momentum- transport equations. This method is applied to the lubrication of a polymeric liquid composed of short chains with ten beads between parallel plates. The rheological properties and conformation of polymer chains coupled with the local viscous heating are investigated with a non-dimensional parameter, i.e., the Nahme-Griffith number, which is defined by the ratio of the viscous heating to the thermal conduction at the characteristic temperature required to sufficiently change the viscosity. The present simulation demonstrates that strong shear thinning and transitional behavior of the conformation of the polymer chains occur with a rapid temperature rise when the Nahme-Griffith number exceeds unity. The results also clarify that the reentrant transition of the linear stress-optical relation occurs for large shear stresses due to the coupling of the conformation of polymer chains and heat generation under shear flows.

  19. Synchronized Molecular-Dynamics Simulation via Macroscopic Heat and Momentum Transfer: An Application to Polymer Lubrication

    NASA Astrophysics Data System (ADS)

    Yasuda, Shugo; Yamamoto, Ryoichi

    2014-10-01

    A synchronized molecular-dynamics simulation via macroscopic heat and momentum transfer is proposed to model the nonisothermal flow behaviors of complex fluids. In this method, the molecular-dynamics simulations are assigned to small fluid elements to calculate the local stresses and temperatures and are synchronized at certain time intervals to satisfy the macroscopic heat- and momentum-transport equations. This method is applied to the lubrication of a polymeric liquid composed of short chains of ten beads between parallel plates. The rheological properties and conformation of the polymer chains coupled with local viscous heating are investigated with a nondimensional parameter, the Nahme-Griffith number, which is defined as the ratio of the viscous heating to the thermal conduction at the characteristic temperature required to sufficiently change the viscosity. The present simulation demonstrates that strong shear thinning and a transitional behavior of the conformation of the polymer chains are exhibited with a rapid temperature rise when the Nahme-Griffith number exceeds unity. The results also clarify that the reentrant transition of the linear stress-optical relation occurs for large shear stresses due to the coupling of the conformation of polymer chains with heat generation under shear flows.

  20. Transfer of Orbital Angular Momentum from a Stressed Fiber-Optic Waveguide to a Light Beam

    Microsoft Academic Search

    David McGloin; Neil B. Simpson; Miles J. Padgett

    1998-01-01

    A stressed fiber-optic waveguide is used to impart orbital angular momentum to a Hermite-Gaussian ~HG10! laser mode. The transmitted beam has an annular intensity profile and a well-defined azimuthal phase dependence. We confirm the phase structure of the beam by observing the interference pattern produced between it and a plane wave. The transfer of the angular momentum to the light

  1. Angular Momentum Transfer in Star-Discs Encounters: The Case of Low-Mass Discs

    E-print Network

    S. Pfalzner

    2003-10-27

    A prerequisite for the formation of stars and planetary systems is that angular momentum is transported in some way from the inner regions of the accretion disc. Tidal effects may play an important part in this angular momentum transport. Here the angular momentum transfer in an star-disc encounter is investigated numerically for a variety of encounter parameters in the case of low mass discs. Although good agreement is found with analytical results for the entire disc, the loss {\\it inside} the disc can be up to an order of magnitude higher than previously assumed. The differences in angular momentum transport by secondaries on a hyperbolic, parabolic and elliptical path are shown, and it is found that a succession of distant encounters might be equally, if not more, successful in removing angular momentum than single close encounter.

  2. Energy and angular momentum transfer in binary galaxies

    NASA Technical Reports Server (NTRS)

    Namboodiri, P. M. S.; Kochhar, R. K.

    1990-01-01

    The authors numerically studied tidal effects of a massive perturber on a satellite galaxy. The model consists of a spherical satellite galaxy and a point mass perturber and the encounter is non-penetrating. A wide range of density ratios and eccentricities of the relative orbits have been considered. The disruption of the satellite galaxy has been observed when the numerical value of the fractional change in the energy is greater than two. The changes in the energy and angular momentum show smooth variation in the case of unbound orbits and irregular variation in the bound orbit cases. It is shown that for a constant pericentral distance, increasing the density ratio decreases the tidal effects; and for a given density ratio an increase in the eccentricity decreases the tidal effects.

  3. New Precision Measurements of Deuteron Structure Function A(Q) at Low Momentum Transfer

    SciTech Connect

    Byungwuek Lee

    2009-08-01

    Differences between previous measurements of low momentum transfer electron-deuteron elastic scattering prevent a clean determination of even the sign of the leading low momentum transfer relativistic corrections, or of the convergence of chiral perturbation theory. We have attempted to resolve this issue with a new high-precision measurement in Jefferson Lab Hall A. Elastic electron scattering was measured on targets of tantalum, carbon, hydrogen, and deuterium at beam energy of 685 MeV. The four-momentum transfer covered the range of 0.15 - 0.7 GeV. The experiment included a new beam calorimeter, to better calibrate the low beam currents used in the experiment, and new collimators to better define the spectrometer solid angles. We obtained cross sections of deuteron as ratios to hydrogen cross sections. A fit function of B(Q) world data is newly made and subtracted from cross sections to find values of A(Q).

  4. Transfer of linear momentum from the quantum vacuum to a magnetochiral molecule

    E-print Network

    Manuel Donaire; Bart van Tiggelen; Geert Rikken

    2015-03-23

    In a recent publication [Phys. Rev. Lett. 111, 143602] we have shown using a QED approach that, in the presence of a magnetic field, the quantum vacuum coupled to a chiral molecule provides a kinetic momentum directed along the magnetic field. Here we explain the physical mechanisms which operate in the transfer of momentum from the vacuum to the molecule. We show that the variation of the molecular kinetic energy originates from the magnetic energy associated with the vacuum correction to the magnetization of the molecule. We carry out a semiclassical calculation of the vacuum momentum and compare the result with the QED calculation.

  5. Search for Color Transparency in a (E, E-Prime P) at High Momentum Transfer

    SciTech Connect

    O'Neill, T

    2004-01-06

    Rates for A({epsilon}, {epsilon}{prime}p) on the nuclei {sup 2}H, C, Fe, and Au have been measured at momentum transfers Q{sup 2} = 1, 3, 5, and 6.8 (GeV/c){sup 2}. They extract the nuclear transparency T, a measure of the importance of final state interactions (FSI) between the outgoing proton and the recoil nucleus. Some calculations based on perturbative QCD predict an increase in T with momentum transfer, a phenomenon known as Color Transparency. No statistically significant rise is seen in the present experiment.

  6. Nuclear spin structure in dark matter search: The finite momentum transfer limit

    E-print Network

    V. A. Bednyakov; F. Simkovic

    2006-08-09

    Spin-dependent elastic scattering of weakly interacting massive dark matter particles (WIMP) off nuclei is reviewed. All available, within different nuclear models, structure functions S(q) for finite momentum transfer (q>0) are presented. These functions describe the recoil energy dependence of the differential event rate due to the spin-dependent WIMP-nucleon interactions. This paper, together with the previous paper ``Nuclear spin structure in dark matter search: The zero momentum transfer limit'', completes our review of the nuclear spin structure calculations involved in the problem of direct dark matter search.

  7. Nuclear spin structure in dark matter search: The finite momentum transfer limit

    NASA Astrophysics Data System (ADS)

    Bednyakov, V. A.; Šimkovic, F.

    2006-12-01

    Spin-dependent elastic scattering of weakly interacting massive dark matter particles (WIMP) off nuclei is reviewed. All available, within different nuclear models, structure functions S(q) for finite momentum transfer (q > 0) are presented. These functions describe the recoil energy dependence of the differential event rate due to the spin-dependent WIMP-nucleon interactions. This paper, together with the previous paper “Nuclear Spin Structure in Dark Matter Search: The Zero Momentum Transfer Limit,” completes our review of the nuclear spin structure calculations involved in the problem of direct dark matter search.

  8. Electrically controlled transfer of spin angular momentum of light in an optically active medium

    NASA Astrophysics Data System (ADS)

    Chen, Lixiang; Zheng, Guoliang; Xu, Jie; Zhang, Bingzhi; She, Weilong

    2006-12-01

    Spin is an intrinsic property of the photon. A method for using an externally applied dc electric field to manipulate the transfer of spin angular momentum of light in an optically active medium is presented. To discuss this, we first develop a wave coupling theory of the mutual action of natural optical activity and the linear electro-optic effect. Besides being used for analyzing the electrically controlled transfer of spin angular momentum of light, the theory can also be used to describe the propagation of light traveling along an arbitrary direction in any optically active medium with an external dc electric field along an arbitrary direction.

  9. Angular momentum transfer by gravitational torques and the evolution of binary protostars

    NASA Technical Reports Server (NTRS)

    Boss, A. P.

    1984-01-01

    The efficiency of angular momentum transport by gravitational torques is investigated semianalytically for two idealized models. The first model, a rotating ellipsoid embedded within another ellipsoid, is compared with numerical results for the fission instability of a radpidly-rotating polytrope. The fission instability is aborted by the rapid transfer of angular momentum outward by gravitational torques. The global rates of angular momentum transfer by gravitational torques in rotating gas clouds such as the presolar nebula are shown to be comparable to the rates assumed to be appropriate for transfer by turbulent stresses. The second model is a binary system embedded within a rotating ellipsoid. The binary orbital angular momentum decreases significantly when the phase angle with the ellipsoid is constant; the binary separation may then decrease by a factor of 100 within about an orbital period. For a variable phase angle, little secular loss of orbital angular momentum occurs. Binaries which form in the isothermal regime of the theory of hierarchical fragmentation will not undergo orbital decay, whereas very close binaries composed of nonisothermal fragments may decay and merge into single objects.

  10. Measuring the Quantum State of a Large Angular Momentum

    E-print Network

    Gerd Klose; Greg Smith; Poul S. Jessen

    2001-01-03

    We demonstrate a general method to measure the quantum state of an angular momentum of arbitrary magnitude. The (2F+1) x (2F+1) density matrix is completely determined from a set of Stern-Gerlach measurements with (4F+1) different orientations of the quantization axis. We implement the protocol for laser cooled Cesium atoms in the 6S_{1/2}(F=4) hyperfine ground state and apply it to a variety of test states prepared by optical pumping and Larmor precession. A comparison of input and measured states shows typical reconstruction fidelities of about 0.95.

  11. Heat and Momentum Transfers under Strong Stability in the Atmospheric Surface Layer

    Microsoft Academic Search

    J. Kondo; O. Kanechika; N. Yasuda

    1978-01-01

    Transfers of heat and momentum under strongly stable conditions in the atmospheric boundary layer have been studied through measurements of the turbulent fluctuations and vertical mean profiles of wind velocity and air temperature. As the local gradient Richardson number increases, intermittent turbulence appears, especially in temperature fluctuations. The ratio of the eddy conductivity to the eddy viscosity decreases with increasing

  12. Polarized neutron scattering investigation of excitations at low momentum transfer in liquid Ga: The mystery continues

    E-print Network

    Montfrooij, Wouter

    Polarized neutron scattering investigation of excitations at low momentum transfer in liquid Ga: Liquid metals; Scattering; Excitations; Sum-rule violation New polarized neutron scattering experiments in the literature. Our polarized neutron scattering experiments show that this increased cross-section cannot

  13. Transfer of orbital angular momentum to an optically trapped low-index particle

    Microsoft Academic Search

    V. Garcés-Chávez; K. Volke-Sepulveda; S. Chávez-Cerda; W. Sibbett; K. Dholakia

    2002-01-01

    We demonstrate the transfer of orbital angular momentum from a light beam to a trapped low-index particle. The particle is trapped in a dark annular region of a high-order Bessel beam and rotates around the beam axis due to scattering from the helical wave fronts of the light beam. A general theoretical geometrical optics model is developed that, applied to

  14. Free-space information transfer using light beams carrying orbital angular momentum

    Microsoft Academic Search

    Graham Gibson; Johannes Courtial; Miles J. Padgett; Mikhail Vasnetsov; Valeriy Pas'ko; Stephen M. Barnett; Sonja Franke-Arnold

    2004-01-01

    We demonstrate the transfer of information encoded as orbital angular momentum (OAM) states of a light beam. The transmitter and receiver units are based on spatial light modulators, which prepare or measure a laser beam in one of eight pure OAM states. We show that the information encoded in this way is resistant to eavesdropping in the sense that any

  15. On the angular momentum transfer on to compact stars in binary systems

    Microsoft Academic Search

    D. Molteni; O. A. Kuznetsov; D. V. Bisikalo; A. A. Boyarchuk

    2001-01-01

    Results of three-dimensional numerical simulations of the gas transfer in close binary systems show that, in addition to the formation of a tidally induced spiral shock wave, it is also possible for accretion streams to be produced, having low specific angular momentum in a region close to the accreting star. These streams are mainly placed above the orbital disc but

  16. Complex chain of momentum transfer of body segments in the baseball pitching motion

    Microsoft Academic Search

    Mari Nakamura; Edmund Y. S. Chao

    2003-01-01

    Baseball pitching requires contributions from and interaction among all limb segments. Most previous investigators have concentrated on the throwing arm itself, but the center of mass (COM) and contribution of all segments in the pitching motion have not been studied. The purpose of this study was to investigate the momentum transfer of all body segments in the pitching motion. The

  17. Effect of large ion angular momentum spread and high current on inertial electrostatic confinement potential structures

    SciTech Connect

    Tzonev, I.V.; DeMora, J.M.; Miley, G.H. [Univ. of Illinois, Urbana, IL (United States)

    1995-12-31

    Prior Inertial Electrostatic Confinement (IEC) studies have assumed that very low angular momentum (zero in the ideal case) is necessary to achieve a potential well structure capable of trapping energetic ions in the center of a spherical device. However, the present study shows that high-current ion beams having large-angular-momentum spread can also form deep potential well traps.

  18. Effect of large ion angular momentum spread and high current on inertial electrostatic confinement potential structures

    Microsoft Academic Search

    Ivon V. Tzonev; John M. DeMora; George H. Miley

    1995-01-01

    Prior inertial electrostatic confinement (IEC) studies have assumed that very low angular momentum (zero in the ideal case) is necessary to achieve a potential well structure capable of trapping energetic ions in the center of a spherical device. However, the present study shows that high-current ion beams having large-angular-momentum spread can also form deep potential well traps

  19. Virtual Compton Scattering Off Protons at Moderately Large Momentum Transfer

    E-print Network

    P. Kroll; M. Schürmann; P. A. M. Guichon

    1995-07-13

    The amplitudes for virtual Compton scattering off protons are calculated within the framework of the diquark model in which protons are viewed as being built up by quarks and diquarks. The latter objects are treated as quasi-elementary constituents of the proton. Virtual Compton scattering, electroproduction of photons and the Bethe-Heitler contamination are discussed for various kinematical situations. We particularly emphasize the r\\^ole of the electron asymmetry for measuring the relative phases between the virtual Compton and the Bethe-Heitler amplitudes. It is also shown that the model is able to describe very well the experimental data for real Compton scattering off protons.

  20. Effects of bonding on the energy distribution of electrons scattered elastically at high momentum transfer

    SciTech Connect

    Vos, M.; Went, M. R. [Atomic and Molecular Physics Laboratories6, Research School of Physical Sciences and Engineering, Australian National University, Canberra ACT 0200 (Australia)

    2006-11-15

    High-resolution measurements of 40-keV electrons scattered over 44.3 deg. from evaporated carbon films are presented. The observed width of the energy distribution of electrons scattered from carbon is significantly larger than the experimental energy resolution, and its position is shifted to lower energy. Measurements were done for transmission and reflection geometries for thin films with thicknesses varying from 90 A ring to 1400 A ring . The observed peak shape is largely independent of the thickness and measurement geometry. The peak shape deviates from Gaussian in all cases, in a way consistent with theories that describe these processes beyond the impulse approximation. The energy shift of the carbon peak is measured by evaporating a small amount of Au on these films. Separation of the Au and C peak is somewhat smaller than calculated assuming scattering from free C and Au atoms, but independent of measurement geometry. Finally spectra were measured from highly oriented pyrolytic graphite (HOPG) films. Now different widths are observed in reflection geometry and transmission geometry. This is attributed to the anisotropy of the motion of the C atoms in HOPG. Also the Au-C separation is slightly orientation dependent for HOPG. All observations agree at least semiquantitatively with neutron Compton scattering results, a related scattering experiment that studies neutron-atom collisions at similar momentum transfers.

  1. The ^2H(e,e'p)n Reaction at High Four-Momentum Transfer

    SciTech Connect

    Hassan Ibrahim

    2006-12-31

    This dissertation presents the highest four-momentum transfer, Q^2,quasielastic (x_Bj = 1) results from Experiment E01-020 which systematically explored the 2He(e,e'p)n reaction ("Electro-disintegration" of the deuteron) at three different four-momentum transfers, Q^2 = 0.8, 2.1, and 3.5 GeV^2 and missing momenta, P_miss = 0, 100, 200, 300, 400, and 500 GeV including separations of the longitudinal-transverse interference response function, R_LT, and extractoin of the longitudinal-transverse asymmetry, A_LT. This systematic approach will help to understand the reaction mechanism and the deuteron structure down to the short range part of the nucleon-nucleon interaction which is one of the fundamental missions of nuclear physics. By studying the very short distance structure of the deuteron, one may also determine whether or to what extent the description of nuclei in terms of nucleon/meson degrees of freedom must be supplemented by inclusion of explicit quark effects. The unique combination of energy, current, duty factor, and control of systematics for Hall A at Jefferson Lab made Jefferson Lab the only facility in the world where these systematic studies of the deuteron can be undertaken. This is especially true when we want to understand the short range structure of the deuteron where high energies and high luminosity/duty factor are needed. All these features of Jefferson Lab allow us to examine large missing momenta (short range scales) at kinematics where the effects of final state interactions (FSI), meson exchange currents (MEC), and isobar currents (IC) are minimal, making the extraction of the deuteron structure less model-dependent. Jefferson Lab also provides the kinematical flexibility to perform the separation of R_LT over a broad range of missing momenta and momentum transfers. Experiment E01-020 use the standard Hall A equipment in coincidence configuration in addition to the cryogenic target system. The low and middle Q^2 kinematics were completed in June 2002 and the high Q^2 kinematics were completed in November 2002. Before the start of the experiment many preparations were made to assure the quality of the collected data. Approximately two Terabytes of data were collected by the end of the experiment. The cross section results in this dissertation show clearly the effect of final state interactions between the two final state nucleons. The cross section ratio to the Laget PWBA+FSI calculation has a wiggle at P_miss ~ 300 MeV. It is yet to be seen whether this is merely due to the lack of MEC and IC in the present theoretical calculation. However, a similar feature was observed in a previous Hall A experiment. Further, discrepancies at very low P_miss cast some doubt on neutron form factor measurements using the deuteron as target. This study will add to the already growing body of systematic data for the ^2H(e,e'p)n reaction to better understand the N N short range and to provide vital input for heavier nuclei.

  2. Linear momentum transfer in the reaction of 64--269 MeV sup 3 He with sup 238 U

    SciTech Connect

    Skulski, W. (Heavy Ion Laboratory, Warsaw University, Warsaw 02-097, Poland (PL) Indiana University Cyclotron Facility, Bloomington, Indiana 47405); Fatyga, M.; Karwowski, H.J.; Kwiatkowski, K.; Viola, V.E. Jr. (Indiana University Cyclotron Facility, Bloomington, Indiana 47405); Hicks, K.; Ristinen, R. (University of Colorado, Boulder, Colorado 80309)

    1989-09-01

    Angular correlations between binary fission fragments have been measured in coincidence with light charged particles for 64, 129, 199, and 269 MeV {sup 3}He-induced reactions on a {sup 238}U target. Linear momentum transfer and missing linear momentum have been determined for a broad range of light-charged-particle energies {ital E}{sub LCP} and emission angles {theta}{sub LCP}. Average momentum transfer increases from a fraction of beam momentum for small detection angles to nearly full momentum transfer at backward angles. The missing momentum depends primarily on available energy'' {ital E}{sub av}=E{sub beam}{minus}E{sub LCP}, but neither on beam energy {ital E}{sub beam} nor light particle detection angle. Backward proton and deuteron emission is incompatible with statistical evaporation following complete or incomplete fusion.

  3. Momentum transfer interaction of a laser-produced plasma with a low-pressure background.

    NASA Technical Reports Server (NTRS)

    Koopman, D. W.

    1972-01-01

    The expansion of a laser-produced metallic plasma into a photoionized hydrogen background has been experimentally studied. Langmuir probe and microwave diagnostics have detected an interaction front which decelerates with a dependence on background density and time consistent with a momentum coupling between the laser plasma and the ionized fraction of the background. An ion percursor has also been observed. Calculations of scattering cross sections indicate that multiple-encounter Coulomb scattering will dominate collisional momentum transfer. The leading edge of the laser plasma contains multiply charged ions of charge state z greater than or equal to 5, and collisional effects appear adequate to explain the principal features of the momentum coupling. The ion precursor may have a collisionless origin.

  4. Energy transfer, orbital angular momentum, and discrete current in a double-ring fiber array

    SciTech Connect

    Alexeyev, C. N.; Volyar, A. V. [Taurida National V.I. Vernadsky University, Vernadsky Prospekt, 4, Simferopol, 95007, Crimea (Ukraine); Yavorsky, M. A. [Taurida National V.I. Vernadsky University, Vernadsky Prospekt, 4, Simferopol, 95007, Crimea (Ukraine); Universite Bordeaux and CNRS, LOMA, UMR 5798, FR-33400 Talence (France)

    2011-12-15

    We study energy transfer and orbital angular momentum of supermodes in a double-ring array of evanescently coupled monomode optical fibers. The structure of supermodes and the spectra of their propagation constants are obtained. The geometrical parameters of the array, at which the energy is mostly confined within the layers, are determined. The developed method for finding the supermodes of concentric arrays is generalized for the case of multiring arrays. The orbital angular momentum carried by a supermode of a double-ring array is calculated. The discrete lattice current is introduced. It is shown that the sum of discrete currents over the array is a conserved quantity. The connection of the total discrete current with orbital angular momentum of discrete optical vortices is made.

  5. Color transparency and correlation effects in quasielastic electron-nucleus scattering at high momentum transfer

    NASA Astrophysics Data System (ADS)

    Benhar, O.; Fabrocini, A.; Fantoni, S.; Pandharipande, V. R.; Sick, I.

    1992-08-01

    The effects of nucleon-nucleon correlations and color transparency on the final-state interaction of the struck nucleon in electron-nucleus scattering at high-momentum transfer are discussed. The results of realistic microscopic calculations show that both the mechanisms lead to an enhancement of the nuclear transparency, and that the correlation effects are larger up to momenta Q2~4 (GeV/c)2.

  6. Momentum transfer cross section of argon deduced from electron drift velocity data

    Microsoft Academic Search

    M. Suzuki; T. Taniguchi; H. Tagashira

    1990-01-01

    The momentum transfer cross section of argon is deduced from experimental electron drift velocity data over the energy range from 0.02 to 100 eV. A method proposed earlier by Suzuki et al. (1989) which is improved by adding a minimising procedure of the fractional difference between calculated and experimental electron drift velocities, is used. In an E\\/N range below 0.1

  7. Spin angular momentum transfer from TEM00 focused Gaussian beams to negative refractive index spherical particles

    PubMed Central

    Ambrosio, Leonardo A.; Hernández-Figueroa, Hugo E.

    2011-01-01

    We investigate optical torques over absorbent negative refractive index spherical scatterers under the influence of linear and circularly polarized TEM00 focused Gaussian beams, in the framework of the generalized Lorenz-Mie theory with the integral localized approximation. The fundamental differences between optical torques due to spin angular momentum transfer in positive and negative refractive index optical trapping are outlined, revealing the effect of the Mie scattering coefficients in one of the most fundamental properties in optical trapping systems. PMID:21833372

  8. Densification of functional plasma polymers by momentum transfer during film growth

    SciTech Connect

    Hegemann, Dirk; Koerner, Enrico; Blanchard, Noemi; Drabik, Martin; Guimond, Sebastien [Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen (Switzerland)

    2012-11-19

    Functional plasma polymers were deposited from pure ethylene discharges and with the addition of carbon dioxide or ammonia. The incorporation of oxygen and nitrogen-containing functional groups depends on the fragmentation in the gas phase as well as on the densification during film growth. While a minimum energy per deposited carbon atom is required for cross-linking, the densification and accompanying reduction of functional group incorporation was found to scale linearly with momentum transfer through ion bombardment during film growth.

  9. Electron-potassium-atom momentum transfer cross section: fit to the experimental data

    Microsoft Academic Search

    B. Stefanov; L. Zarkova

    1987-01-01

    Experiments related to the electron-potassium-atom momentum transfer cross section Q(v) are considered in which the electrical and electron thermal conductivities are measured in equilibrium and non-equilibrium pure potassium and argon-potassium plasmas. Measurements of differential cross sections are also taken into account. A convenient algorithm is used to vary Q(v) until the best fit to all data is obtained. The result

  10. Electron momentum-transfer cross section in cesium: Fit to the experimental data

    Microsoft Academic Search

    B. Stefanov

    1980-01-01

    Experiments related to the electron-cesium-atom momentum-transfer cross section Q(v) in the range of energies ?=mv22 from 0.05 to 2 eV are considered in which the following quantities are measured: (a) width of the electron cyclotron resonance, (b) attenuation of microwaves, (c) electrical conductivity in both equilibrium and nonequilibrium pure Cs or Ar - Cs plasmas, (d) electron thermal conductivity, (e)

  11. The relative importance of ejections and sweeps to momentum transfer in the atmospheric boundary layer

    Microsoft Academic Search

    Gabriel Katul; Davide Poggi; Daniela Cava; John Finnigan

    2006-01-01

    Using an incomplete third-order cumulant expansion method (ICEM) and standard second-order closure principles, we show that the imbalance in the stress contribution of sweeps and ejections to momentum transfer (?S\\u000a \\u000a o\\u000a ) can be predicted from measured profiles of the Reynolds stress and the longitudinal velocity standard deviation for different boundary-layer regions. The ICEM approximation is independently verified using flume

  12. Electron impact excitation of SO2 - Differential, integral, and momentum transfer cross sections

    NASA Technical Reports Server (NTRS)

    Vuskovic, L.; Trajmar, S.

    1982-01-01

    Electron impact excitation of the electronic states of SO2 was investigated. Differential, integral, and inelastic momentum transfer cross sections were obtained by normalizing the relative measurements to the elastic cross sections. The cross sections are given for seven spectral ranges of the energy-loss spectra extending from the lowest electronic state to near the first ionization limit. Most of the regions represent the overlap of several electronic transitions. No measurements for these cross sections have been reported previously.

  13. Higher-Twist Dynamics in Large Transverse Momentum Hadron Production

    SciTech Connect

    Arleo, Francois; /Annecy, LAPTH; Brodsky, Stanley J.; /SLAC; Hwang, Dae Sung; /Sejong U.; Sickles, Anne M.; /Brookhaven

    2009-12-17

    A scaling law analysis of the world data on inclusive large-p{sub {perpendicular}} hadron production in hadronic collisions is carried out. A significant deviation from leading-twist perturbative QCD predictions at next-to-leading order is reported. The observed discrepancy is largest at high values of x{sub {perpendicular}} = 2p{sub {perpendicular}}/{radical}s. In contrast, the production of prompt photons and jets exhibits the scaling behavior which is close to the conformal limit, in agreement with the leading-twist expectation. These results bring evidence for a non-negligible contribution of higher-twist processes in large-p{sub {perpendicular}} hadron production in hadronic collisions, where the hadron is produced directly in the hard subprocess rather than by gluon or quark jet fragmentation. Predictions for scaling exponents at RHIC and LHC are given, and it is suggested to trigger the isolated large-p{sub {perpendicular}} hadron production to enhance higher-twist processes.

  14. The impulsive effects of momentum transfer on the dynamics of a novel ocean wave energy converter

    NASA Astrophysics Data System (ADS)

    Diamond, Christopher A.; O'Reilly, Oliver M.; Sava?, Ömer

    2013-10-01

    In a recent paper by Orazov et al. [On the dynamics of a novel ocean wave energy converter. Journal of Sound and Vibration329 (24) (2010) 5058-5069], a wave energy converter (WEC) was proposed. The converter features a mass modulation scheme and a simple model was used to examine its efficacy. The simple model did not adequately account for the momentum transfer which takes place during the mass modulation. The purpose of the present paper is to account for this transfer and to show that the WEC equipped with a novel and more general mass modulation scheme has the potential to improve its energy harvesting capabilities.

  15. Mass and momentum transfer across solid-fluid boundaries in the lattice-Boltzmann method.

    PubMed

    Yin, Xuewen; Le, Guigao; Zhang, Junfeng

    2012-08-01

    Mass conservation and momentum transfer across solid-fluid boundaries have been active topics through the development of the lattice-Boltzmann method. In this paper, we review typical treatments to prevent net mass transfer across solid-fluid boundaries in the lattice-Boltzmann method, and argue that such efforts are in general not necessary and could lead to incorrect results. Carefully designed simulations are conducted to examine the effects of normal boundary movement, tangential density gradient, and lattice grid resolution. Our simulation results show that the global mass conservation can be well satisfied even with local unbalanced mass transfer at boundary nodes, while a local mass conservation constraint can produce incorrect flow and pressure fields. These simulations suggest that local mass conservation, at either a fluid or solid boundary node, is not only an unnecessary consequence to maintain the global mass conservation, but also harmful for meaningful simulation results. In addition, the concern on the momentum addition and reduction associated with status-changing nodes is also not technically necessary. Although including this momentum addition or reduction has no direct influence on flow and pressure fields, the incorrect fluid-particle interaction may affect simulation results of particulate suspensions. PMID:23005876

  16. Unsteady Analysis of Blade and Tip Heat Transfer as Influenced by the Upstream Momentum and Thermal Wakes

    NASA Technical Reports Server (NTRS)

    Ameri, Ali A.; Rigby, David L.; Steinthorsson, Erlendur; Heidmann, James D.; Fabian, John C.

    2008-01-01

    The effect of the upstream wake on the blade heat transfer has been numerically examined. The geometry and the flow conditions of the first stage turbine blade of GE s E3 engine with a tip clearance equal to 2 percent of the span was utilized. Based on numerical calculations of the vane, a set of wake boundary conditions were approximated, which were subsequently imposed upon the downstream blade. This set consisted of the momentum and thermal wakes as well as the variation in modeled turbulence quantities of turbulence intensity and the length scale. Using a one-blade periodic domain, the distributions of unsteady heat transfer rate on the turbine blade and its tip, as affected by the wake, were determined. Such heat transfer coefficient distribution was computed using the wall heat flux and the adiabatic wall temperature to desensitize the heat transfer coefficient to the wall temperature. For the determination of the wall heat flux and the adiabatic wall temperatures, two sets of computations were required. The results were used in a phase-locked manner to compute the unsteady or steady heat transfer coefficients. It has been found that the unsteady wake has some effect on the distribution of the time averaged heat transfer coefficient on the blade and that this distribution is different from the distribution that is obtainable from a steady computation. This difference was found to be as large as 20 percent of the average heat transfer on the blade surface. On the tip surface, this difference is comparatively smaller and can be as large as four percent of the average.

  17. Photon momentum transfer plane for asteroid, meteoroid, and comet orbit shaping

    NASA Technical Reports Server (NTRS)

    Campbell, Jonathan W. (Inventor)

    2004-01-01

    A spacecraft docks with a spinning and/or rotating asteroid, meteoroid, comet, or other space object, utilizing a tether shaped in a loop and utilizing subvehicles appropriately to control loop instabilities. The loop is positioned about a portion of the asteroid and retracted thereby docking the spacecraft to the asteroid, meteoroid, comet, or other space object. A deployable rigidized, photon momentum transfer plane of sufficient thickness may then be inflated and filled with foam. This plane has a reflective surface that assists in generating a larger momentum from impinging photons. This plane may also be moved relative to the spacecraft to alter the forces acting on it, and thus on the asteroid, meteoroid, comet, or other space object to which it is attached. In general, these forces may be utilized, over time, to alter the orbits of asteroids, meteoroids, comets, or other space objects. Sensors and communication equipment may be utilized to allow remote operation of the rigidized, photon momentum transfer plane and tether.

  18. An investigation of the normal momentum transfer for gases on tungsten

    NASA Technical Reports Server (NTRS)

    Moskal, E. J.

    1971-01-01

    The near monoenergetic beam of neutral helium and argon atoms impinged on a single crystal tungsten target, with the (100) face exposed to the beam. The target was mounted on a torsion balance. The rotation of this torsion balance was monitored by an optical lever, and this reading was converted to a measurement of the momentum exchange between the beam and the target. The tungsten target was flashed to a temperature in excess of 2000 C before every clean run, and the vacuum levels in the final chamber were typically between 0.5 and 1 ntorr. The momentum exchange for the helium-tungsten surface and the argon-tungsten surface combination was obtained over approximately a decade of incoming energy (for the argon gas) at angles of incidence of 0, 30, and 41 deg on both clean and dirty (gas covered) surfaces. The results exhibited a significant variation in momentum transfer between the data obtained for the clean and dirty surfaces. The values of normal momentum accommodation coefficient for the clean surface were found to be lower than the values previously reported.

  19. Meson-exchange currents and final-state interactions in quasielastic electron scattering at high momentum transfers

    E-print Network

    Amaro, J. E.

    The effects of meson-exchange currents (MEC) are computed for the one-particle one-hole transverse response function for finite nuclei at high momentum transfers q in the region of the quasi-elastic peak. A semirelativistic ...

  20. Rotating fiber array molecular driver and molecular momentum transfer device constructed therewith

    DOEpatents

    Milleron, Norman (1854 San Juan, Berkeley, CA 94707)

    1983-01-01

    A rotating fiber array molecular driver is disclosed which includes a magnetically suspended and rotated central hub to which is attached a plurality of elongated fibers extending radially therefrom. The hub is rotated so as to straighten and axially extend the fibers and to provide the fibers with a tip speed which exceeds the average molecular velocity of fluid molecules entering between the fibers. Molecules colliding with the sides of the rotating fibers are accelerated to the tip speed of the fiber and given a momentum having a directional orientation within a relatively narrow distribution angle at a point radially outward of the hub, which is centered and peaks at the normal to the fiber sides in the direction of fiber rotation. The rotating fiber array may be used with other like fiber arrays or with other stationary structures to form molecular momentum transfer devices such as vacuum pumps, molecular separators, molecular coaters, or molecular reactors.

  1. Quantum information transfer from spin to orbital angular momentum of photons

    E-print Network

    Eleonora Nagali; Fabio Sciarrino; Francesco De Martini; Lorenzo Marrucci; Bruno Piccirillo; Ebrahim Karimi; Enrico Santamato

    2009-05-13

    The optical "spin-orbit" coupling occurring in a suitably patterned nonuniform birefringent plate known as `q-plate' allows entangling the polarization of a single photon with its orbital angular momentum (OAM). This process, in turn, can be exploited for building a bidirectional "spin-OAM interface", capable of transposing the quantum information from the spin to the OAM degree of freedom of photons and \\textit{vice versa}. Here, we experimentally demonstrate this process by single-photon quantum tomographic analysis. Moreover, we show that two-photon quantum correlations such as those resulting from coalescence interference can be successfully transferred into the OAM degree of freedom.

  2. Interpretation of coastal wind transfer functions with momentum balances derived from idealized numerical model simulations

    NASA Astrophysics Data System (ADS)

    Kim, Sung Yong; Gopalakrishnan, Ganesh; Ponte, Aurelien

    2015-01-01

    The local wind-driven circulation off southern San Diego is addressed with two complementary statistical and dynamical frameworks based on observations and idealized numerical model simulations. The observations including surface currents from high-frequency radars, subsurface currents from a nearshore mooring, and wind records at a local wind station are analyzed with the idealized ocean model (MITgcm) simulations using realistic bottom topography and spatially uniform wind stress forcing. Statistically estimated anisotropic local wind transfer functions characterize the observed oceanic spectral response to wind stress separately in the x (east-west) and y (north-south) directions. We delineate the coastal circulation at three primary frequencies [low ( ? L=0.0767 cycles per day (cpd)), diurnal ( ? D=1 cpd), and inertial ( ? f=1.07 cpd) frequencies] with the momentum budget equations and transfer functions. At low frequency, the magnitudes of transfer functions are enhanced near the coast, attributed to geostrophic balance between wind-driven pressure gradients and the Coriolis force on currents. The response diminishes away from the coast, returning to the balance between frictional and Coriolis terms, as in the classic Ekman model. On the contrary, transfer functions in the near-inertial frequency band show reduced magnitudes near the coast primarily due to friction, but exhibits the enhanced seaward response as a result of the inertial resonance. The idealized model simulations forced by local wind stress can identify the influences of remote wind stress and the biases in the data-derived transfer functions.

  3. Modal damping enhancement in large space structures using AMCD's. [Angular Momentum Control Device

    NASA Technical Reports Server (NTRS)

    Joshi, S. M.; Groom, N. J.

    1980-01-01

    The use of an annular momentum control device (AMCD) is proposed for enhancing the modal damping of large space structures (LSS's) during fine pointing missions. Theoretical and experimental studies proved that an AMCD cannot destabilize the LSS and that the system is asymptotically stable under certain conditions.

  4. Transfer of orbital angular momentum of light using two-component slow light

    NASA Astrophysics Data System (ADS)

    Ruseckas, Julius; Kudriašov, Via?eslav; Yu, Ite A.; Juzeli?nas, Gediminas

    2013-05-01

    We study the manipulation of slow light with an orbital angular momentum propagating in a cloud of cold atoms. Atoms are affected by four co-propagating control laser beams in a double tripod configuration of the atomic energy levels involved, allowing us to minimize the losses at the vortex core of the control beams. In such a situation the atomic medium is transparent for a pair of co-propagating probe fields, leading to the creation of two-component (spinor) slow light. We study the interaction between the probe fields when two control beams carry optical vortices of opposite helicity. As a result, a transfer of the optical vortex takes place from the control to the probe fields without switching off and on the control beams. This feature is missing in a single tripod scheme where the optical vortex can be transferred from the control to the probe field only during either the storage or retrieval of light.

  5. Angular Momentum Transfer by Low Frequency Modes in Rapidly Rotating Slowly Pulsating B Stars

    NASA Astrophysics Data System (ADS)

    Lee, U.

    2013-12-01

    We discuss angular momentum transfer by non-axisymmetric low frequency modes in rapidly rotating slowly pulsating B (SPB) stars, in which low frequency g- and r-modes are excited by an opacity bump mechanism associated with the iron abundance. We use a mean flow equation, which is derived under the Lagrangian mean formalism, to discuss the forcing on the zonal mean flow (rotation), caused by pulsationally unstable low frequency modes in these stars. For rapidly rotating SPB stars, only prograde g-modes may become pulsationally unstable because retrograde g-modes are likely to be stabilized by the effects of rapid rotation. Since weak differential rotation in the outer envelope tends to stabilize r-modes of |m| ? 2 with m being the azimuthal wave number, only retrograde r-modes of |m| = 1 and prograde g-modes may play a role in angular momentum transfer in these stars. Although low frequency modes work for both acceleration and deceleration of the mean flow, assuming contributions to acceleration of the mean flow are dominant, we construct a disc-star model, in which a rapidly rotating star steadily expels gas material from the equatorial region to form a viscous Keplerian decretion disc around it.

  6. Irregular spin angular momentum transfer from light to small birefringent particles

    SciTech Connect

    Rothmayer, M.; Tierney, D.; Schmitzer, H. [Department of Physics, Xavier University, 3800 Victory Parkway, Cincinnati, Ohio 45207 (United States); Frins, E. [Facultad de Ingenieria, Instituto de Fisica, J. Herrera y Reissig 565, 11300 Montevideo (Uruguay); Dultz, W. [Physikalisches Institut, Johann Wolfgang Goethe-Universitaet, PF 111932, D-60054, Frankfurt am Main (Germany)

    2009-10-15

    The transfer of spin angular momentum from photons to small particles is a key experiment of quantum physics. The particles rotate clockwise or counterclockwise depending on the polarization of the light beam which holds them in an optical trap. We show that even perfectly disk shaped particles will in general not rotate with a constant angular speed. The particles will periodically accelerate and decelerate their rotational motion due to a varying spin angular momentum transfer from the light. Using the Poincare sphere we derive the equation of motion of a birefringent plate and verify the results by measuring the time dependent rotation of small crystals of Hg(I) iodide and 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) in the trap of polarized optical tweezers. For small ellipticities of the polarized light in the tweezers the plate stops in a fixed orientation relative to the axes of the light ellipse. We discuss the origin of this halt and propose an application of small birefringent plates as self-adjusting optical retarders in micro-optics.

  7. Fermi-level pinning, charge transfer, and relaxation of spin-momentum locking at metal contacts to topological insulators

    NASA Astrophysics Data System (ADS)

    Spataru, Catalin D.; Léonard, François

    2014-08-01

    Topological insulators are of interest for many applications in electronics and optoelectronics, but harnessing their unique properties requires detailed understanding and control of charge injection at electrical contacts. Here we present large-scale ab initio calculations of the electronic properties of Au, Ni, Pt, Pd, and graphene contacts to Bi2Se3. We show that regardless of the metal, the Fermi level is located in the conduction band, leading to n-type Ohmic contact to the first quintuplet. Furthermore, we find strong charge transfer and band bending in the first few quintuplets, with no Schottky barrier for charge injection even when the topological insulator is undoped. Our calculations indicate that Au and graphene leave the spin-momentum locking mostly unaltered, but on the other hand, Ni, Pd, and Pt strongly hybridize with Bi2Se3 and relax spin-momentum locking. Our results indicate that judicious choice of the contact metal is essential to reveal the unique surface features of topological insulators.

  8. Hypervelocity cratering and disruption of porous pumice targets: Implications for crater production, catastrophic disruption, and momentum transfer on porous asteroids

    NASA Astrophysics Data System (ADS)

    Flynn, George J.; Durda, Daniel D.; Patmore, Emma B.; Clayton, Angela N.; Jack, Sarah J.; Lipman, Miriam D.; Strait, Melissa M.

    2015-03-01

    Most asteroids for which porosities have been inferred have porosities from 20% to>50%. To investigate the effects of target porosity on cratering, impact disruption, and momentum transfer we performed a series of 17 hypervelocity impact experiments on high-porosity (60% to 85% porous), terrestrial, pumice targets impacted at speeds ranging from 3.5 to 5.2 km/s at the NASA Ames Vertical Gun Range. Eleven disruptions demonstrated that pumice targets are significantly stronger, i.e., they require more impactor kinetic energy per unit target mass to produce an equivalent disruption, than non-porous targets. The threshold collisional specific energy, QD*, for this pumice is ~2380 J/kg, more than 60% greater than the value previously determined for ordinary chondrite meteorites having ~10% porosity, and more than three times the literature value for non-porous terrestrial basalt. As a result, in the same impactor environment non-porous asteroids, with properties similar to terrestrial basalt, and highly porous asteroids with the properties of this pumice are equally likely to be disrupted, possibly explaining the survival of asteroids with moderate or high porosity. The six cratering events produced steep-walled, roughly cylindrical craters, with depth/diameter ratios of ~1 to ~2.7, rather than the bowl-shaped craters with depth/diameter ~0.5 produced in non-porous targets. Computed microtomography shows little or no damage to the pumice outside the excavated crater volume even for impactor energies of approximately one-half QD*, an energy shown to produce global damage in non-porous targets. Two large, overlapping craters were produced by successive hypervelocity impacts into one pumice target, a result consistent with the interpretation of the large, overlapping craters on the asteroid 253 Mathilde being a result of its high (>50%) porosity. We measured the post-impact momentum of a pumice target, showing that the recoil from the crater ejecta exceeded the direct momentum transferred by absorption of the projectile by ~30%.

  9. Signatures of Short-Range Many-Body Effects in the Dielectric Function of Silicon for Finite Momentum Transfer

    NASA Astrophysics Data System (ADS)

    Weissker, Hans-Christian; Serrano, Jorge; Huotari, Simo; Bruneval, Fabien; Sottile, Francesco; Monaco, Giulio; Krisch, Michael; Olevano, Valerio; Reining, Lucia

    2006-12-01

    We present an investigation of the dynamic structure factor and of the dielectric function ?M(Q,?) of the prototypical semiconductor silicon for finite momentum transfer, combining inelastic x-ray scattering experiments and ab initio calculations. In contrast with optical spectra, for finite momentum transfer time-dependent density-functional theory in the adiabatic local-density approximation together with lifetime broadening describes the physics of valence excitations correctly. Major structures in the spectra, governed by short-range crystal and exchange-correlation local-field effects, are strongly influenced by a mixing of transitions of positive and negative energies, in striking difference to spectra for vanishing momentum transfer. This mixing gives rise to a pronounced Fano asymmetry.

  10. Tracing sunspot groups to determine angular momentum transfer on the Sun

    NASA Astrophysics Data System (ADS)

    Sudar, D.; Skoki?, I.; Ruždjak, D.; Brajša, R.; Wöhl, H.

    2014-04-01

    In this paper, our goal is to investigate Reynolds stress and to check whether it is plausible that this is responsible for angular momentum transfer towards the solar equator. We have also analysed meridional velocity, rotation velocity residuals and correlation between the velocities. We have used the position measurements of sunspot groups from the Greenwich Photographic Result and the Solar Observing Optical Network/United States Air Force/National Oceanic and Atmospheric Administration data bases, covering the period 1878-2011. In order to calculate the velocities, we used the daily motion of sunspot groups. The sample was also limited to ±58° in the central meridian distance in order to avoid solar limb effects. We have mainly investigated velocity patterns depending on the solar cycle phase and latitude. We have found that the meridional motion of sunspot groups is towards the centre of activity from all available latitudes and in all phases of the solar cycle. The range of meridional velocities is ±10 m s-1. Horizontal Reynolds stress is negative at all available latitudes and indicates that there is a minimum value (q ? -3000 m2 s-2) located at b ? ±30°. In our convention, this means that angular momentum is transported towards the solar equator, in agreement with the observed rotational profile of the Sun.

  11. Stability of curvature perturbation with new covariant form for energy-momentum transfer in dark sector

    E-print Network

    Cheng-Yi Sun; Yu Song; Rui-Hong Yue

    2011-10-09

    It was found that the model with interaction between cold dark matter (CDM) and dark energy (DE) proportional to the energy density of CDM $\\rho_m$ and constant equation of state of DE $w_d$ suffered from instabilities of the density perturbations on the supper-Hubble scales. Here we suggest a new covariant model for the energy-momentum transfer between CDM and DE. Then using the covariant model, we analyze the evolution of density perturbations on the supper-Hubble scale. We find that the instabilities can be avoided in the model with constant $w_d$ and interaction proportional to $\\rho_m$. Furthermore, we analyze the dominant non-adiabatic mode in the radiation era and find that the mode grows regularly.

  12. Distinguishing nonlinear processes in atomic media via orbital angular momentum transfer

    NASA Astrophysics Data System (ADS)

    Akulshin, Alexander M.; McLean, Russell J.; Mikhailov, Eugeniy E.; Novikova, Irina

    2015-03-01

    We suggest a technique based on the transfer of topological charge from applied laser radiation to directional and coherent optical fields generated in ladder-type excited atomic media to identify the major processes responsible for their appearance. As an illustration, in Rb vapours we analyse transverse intensity and phase profiles of the forward-directed collimated blue and near-IR light using self-interference and astigmatic transformation techniques when either or both of two resonant laser beams carry orbital angular momentum. Our observations unambiguously demonstrate that emission at 1.37 {\\mu}m is the result of a parametric four-wave mixing process involving only one of the two applied laser fields.

  13. Distinguishing nonlinear processes in atomic media via orbital angular momentum transfer

    E-print Network

    Akulshin, Alexander M; Mikhailov, Eugeniy E; Novikova, Irina

    2014-01-01

    We suggest a technique based on the transfer of topological charge from applied laser radiation to directional and coherent optical fields generated in ladder-type excited atomic media to identify the major processes responsible for their appearance. As an illustration, in Rb vapours we analyse transverse intensity and phase profiles of the forward-directed collimated blue and near-IR light using self-interference and astigmatic transformation techniques when either or both of two resonant laser beams carry orbital angular momentum. Our observations unambiguously demonstrate that emission at 1.37 {\\mu}m is the result of a parametric four-wave mixing process involving only one of the two applied laser fields.

  14. Recoil polarization measurements of the proton electromagnetic form factor ratio to high momentum transfer.

    SciTech Connect

    Puckett, A. J. R.; Brash, E.J.; Jones, M. K.; Luo, W.; Meziane, M.; Arrington, J.; Hafidi, K.; Reimer, P.; Solvignon, P. (Physics); (Massachusetts Inst. of Tech.); (Christopher Newport Univ.); (Thomas Jefferson National Accelerator Facility); (Lanzhou Univ.); (Coll. of William and Mary)

    2010-01-01

    Among the most fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing the strong interaction dynamics of the nucleon's quark constituents; indeed, recent proton data have attracted intense theoretical interest. In this Letter, we report new measurements of the proton electromagnetic form factor ratio using the recoil polarization method, at momentum transfers Q{sup 2} = 5.2, 6.7, and 8.5 GeV{sup 2}. By extending the range of Q{sup 2} for which G{sub E}{sup p} is accurately determined by more than 50%, these measurements will provide significant constraints on models of nucleon structure in the nonperturbative regime.

  15. Electroproduction of Eta Mesons in the S11(1535) Resonance Region at High Momentum Transfer

    SciTech Connect

    Dalton, Mark; Adams, Gary; Ahmidouch, Abdellah; Angelescu, Tatiana; Arrington, John; Asaturyan, Razmik; Baker, Keith; Benmouna, Nawal; Bertoncini, Crystal; Boeglin, Werner; Bosted, Peter; Breuer, Herbert; Christy, Michael; Connell, S.; Cui, Y.; Danagoulian, Samuel; Day, Donal; Dodario, T.; Dunne, James; Dutta, Dipangkar; Khayari, N.El; Ent, R.; Fenker, Howard; Frolov, Valera; Gan, Liping; Gaskell, David; Hafidi, Kawtar; Hinton, Wendy; Holt, Roy; Horn, Tanja; Huber, Garth; Hungerford, Ed; Jiang, Xiaodong; Jones, Mark; Joo, Kyungseon; Kalantarians, Narbe; Kelly, J.J.; Keppel, Cynthia; Koubarovski, Valeri; Kubarovsky, Valery; Kubarovsky, Valery; Kubarovsky, Valery; Li, Y.; Liang, Y.; Malace, S.; Markowitz, Pete; McKee, Paul; Meekins, David; Mkrtchyan, Hamlet; Moziak, B.; Navasardyan, Tigran; Niculescu, Gabriel; Niculescu, Maria-Ioana; Opper, Allena; Ostapenko, Tanya; Reimer, Paul; Reinhold, Joerg; Roche, Julie; ROCK, S.E.; Schulte, Elaine; Segbefia, Edwin; Smith, C.; Smith, Gregory; Stoler, Paul; Tadevosyan, Vardan; Tang, Liguang; Tvaskis, Vladas; Ungaro, Maurizio; Uzzle, Alicia; Vidakovic, S.; Villano, A.; Vulcan, William; WANG, M.; Warren, Glen; Wesselmann, Frank; Wojtsekhowski, Bogdan; Wood, Stephen; Xu, C.; Yuan, Lulin; Zheng, Xiaochao; Guo Zhu, Hong

    2009-01-01

    The differential cross-section for the process p(e,e'p)eta has been measured at Q2 ~ 5.7 and 7.0 (GeV/c)2 for centre-of-mass energies from threshold to 1.8 GeV, encompassing the S11(1535) resonance, which dominates the channel. This is the highest momentum transfer measurement of this exclusive process to date. The helicity-conserving transition amplitude A_1/2, for the production of the S11(1535) resonance, is extracted from the data. This quantity appears to begin scaling as 1/Q3, a predicted signal of the dominance of perturbative QCD, at Q2 ~ 5 (GeV/c)2.

  16. Distinguishing nonlinear processes in atomic media via orbital angular momentum transfer

    E-print Network

    Alexander M. Akulshin; Russell J. McLean; Eugeniy E. Mikhailov; Irina Novikova

    2014-12-21

    We suggest a technique based on the transfer of topological charge from applied laser radiation to directional and coherent optical fields generated in ladder-type excited atomic media to identify the major processes responsible for their appearance. As an illustration, in Rb vapours we analyse transverse intensity and phase profiles of the forward-directed collimated blue and near-IR light using self-interference and astigmatic transformation techniques when either or both of two resonant laser beams carry orbital angular momentum. Our observations unambiguously demonstrate that emission at 1.37 {\\mu}m is the result of a parametric four-wave mixing process involving only one of the two applied laser fields.

  17. Distinguishing nonlinear processes in atomic media via orbital angular momentum transfer.

    PubMed

    Akulshin, Alexander M; McLean, Russell J; Mikhailov, Eugeniy E; Novikova, Irina

    2015-03-15

    We suggest a technique based on the transfer of topological charge from applied laser radiation to directional and coherent optical fields generated in ladder-type excited atomic media to identify the major processes responsible for their appearance. As an illustration, in Rb vapors, we analyze transverse intensity and phase profiles of the forward-directed collimated blue and near-IR light using self-interference and astigmatic transformation techniques when either or both of two resonant laser beams carry orbital angular momentum. Our observations unambiguously demonstrate that emission at 1.37 ?m is the result of a parametric four-wave mixing process involving only one of the two applied laser fields. PMID:25768194

  18. R×B drift momentum spectrometer with high resolution and large phase space acceptance

    PubMed Central

    Wang, X.; Konrad, G.; Abele, H.

    2013-01-01

    We propose a new type of momentum spectrometer, which uses the R×B drift effect to disperse the charged particles in a uniformly curved magnetic field, and measures the particles with large phase space acceptance and high resolution. This kind of R×B spectrometer is designed for the momentum analyses of the decay electrons and protons in the PERC (Proton and Electron Radiation Channel) beam station, which provides a strong magnetic field to guide the charged particles in the instrument. Instead of eliminating the guiding field, the R×B spectrometer evolves the field gradually to the analysing field, and the charged particles can be adiabatically transported during the dispersion and detection. The drifts of the particles have similar properties as their dispersion in the normal magnetic spectrometer. Besides, the R×B spectrometer is especially ideal for the measurements of particles with low momenta and large incident angles. We present a design of the R×B spectrometer, which can be used in PERC. For the particles with solid angle smaller than 88 msr, the maximum aberration is below 10?4. The resolution of the momentum spectra can reach 14.4 keV/c, if the particle position measurements have a resolution of 1 mm. PMID:23576831

  19. Measurement of the Nuclear Dependence and Momentum Transfer Dependence of Quasielastic (e,e'p) Scattering at Large Momentum Transfer

    NASA Astrophysics Data System (ADS)

    McKee, David; E94-139 Collaboration

    1999-10-01

    We present preliminary results for a new measurement of nuclear transparency in (e,e'p) on H_2, D_2, ^12 C, and ^56 Fe at Q^2 = 3.3, 6.0, and 8.0 (GeV/c)^2. Nuclear transparency can be defined in terms of the ratio of the per-nucleon cross section for a process occurring in a nuclear environment to that occurring on a bare nucleon: for example, ?(p+Aarrow p+p+X)/A?(p+parrow p+p). Theoretical considerations suggest that there may be a rise in the nuclear transparency at moderate values of Q^2---called color transparency. Previous work studied nuclear transparency in the (e,e'p) [at Bates, SLAC NE18 and TJNAF E91-013], (p,2p) [at Brookhaven], and (e,e'?) [at FNAL E665 and HERMES]. systems. The (e,e'p) reaction is well suited to studying this effect because the electron-proton cross section is well understood. E94-139 at the Thomas Jefferson National Accelerator Facility aims to improve the understanding of this phenomena both by reducing the measurement uncertainties over a previously known kinematic region, and by extending the world data set for (e,e'p) up to Q^2 = 8.0 (GeV/c)^2, higher than has been explored before.

  20. Experimental Investigation of Turbulent Momentum Transfer in a Neutral Boundary Layer over a Rough Surface

    NASA Astrophysics Data System (ADS)

    Tomas, Severine; Eiff, Olivier; Masson, Valery

    2011-03-01

    The turbulent characteristics of the neutral boundary layer developing over rough surfaces are not well predicted with operational weather-forecasting models. The problem is attributed to inadequate mixing-length models, to the anisotropy of the flow and to a lack of controlled experimental data against which to validate numerical studies. Therefore, in order to address directly the modelling difficulties for the development of a neutral boundary layer over rough surfaces, and to investigate the turbulent momentum transfer of such a layer, a set of hydraulic flume experiments were carried out. In the experiments, the mean and turbulent quantities were measured by a particle image velocimetry (PIV) technique. The measured velocity variances and fluxes {(overline{{ui^'{uj^')} in longitudinal vertical planes allowed the vertical and longitudinal gradients (?/? z and ?/? x) of the mean and turbulent quantities (fluxes, variances and third-order moments) to be evaluated and the terms of the evolution equations for ? e/? t, {partial overline{u^' 2}}/partial t}, {partial overline{w^' 2}}/partial t} and {partial overline{{u^'{w^'/partial t} to be quantified, where e is the turbulent kinetic energy. The results show that the pressure-correlation terms allow the turbulent energy to be transferred equitably from {overline{{u^'2}} to {overline{{w^'2}}. It appears that the repartition between the constitutive terms of the budget of e, {overline{{u^'2}}, {overline{{w^'2}} and {overline{{u^'{w^' is not significantly affected by the development of the rough neutral boundary layer. For the whole evolution, the transfers of energy are governed by the same terms that are also very similar to the smooth-wall case. The PIV measurements also allowed the spatial integral scales to be computed directly and to be compared with the dissipative and mixing length scales, which were also computed from the data.

  1. Quantized spin-momentum transfer in atom-sized magnetic systems

    NASA Astrophysics Data System (ADS)

    Loth, Sebastian

    2010-03-01

    Our ability to quickly access the vast amounts of information linked in the internet is owed to the miniaturization of magnetic data storage. In modern disk drives the tunnel magnetoresistance effect (TMR) serves as sensitive reading mechanism for the nanoscopic magnetic bits [1]. At its core lies the ability to control the flow of electrons with a material's magnetization. The inverse effect, spin transfer torque (STT), allows one to influence a magnetic layer by high current densities of spin-polarized electrons and carries high hopes for applications in non-volatile magnetic memory [2]. We show that equivalent processes are active in quantum spin systems. We use a scanning tunneling microscope (STM) operating at low temperature and high magnetic field to address individual magnetic structures and probe their spin excitations by inelastic electron tunneling [3]. As model system we investigate transition metal atoms adsorbed to a copper nitride layer grown on a Cu crystal. The magnetic atoms on the surface possess well-defined spin states [4]. Transfer of one magnetic atom to the STM tip's apex creates spin-polarization in the probe tip. The combination of functionalized tip and surface adsorbed atom resembles a TMR structure where the magnetic layers now consist of one magnetic atom each. Spin-polarized current emitted from the probe tip not only senses the magnetic orientation of the atomic spin system, it efficiently transfers spin angular momentum and pumps the quantum spin system between the different spin states. This enables further exploration of the microscopic mechanisms for spin-relaxation and stability of quantum spin systems. [4pt] [1] Zhu and Park, Mater. Today 9, 36 (2006).[0pt] [2] Huai, AAPPS Bulletin 18, 33 (2008).[0pt] [3] Heinrich et al., Science 306, 466 (2004).[0pt] [4] Hirjibehedin et al., Science 317, 1199 (2007).

  2. Heat transfer to large objects in large pool fires

    SciTech Connect

    Bainbridge, B.L.; Keltner, N.R.

    1987-01-01

    Large pool fires are used to expose radioactive material shipping containers to levels of temperature and heat flux required by regulatory agencies. Due to the nature of outdoor pool fires, a large effort has gone into characterizing the temporal and spatial variability of the thermal environment. Three tests were performed in the summer of 1983 involving a 9.1 by 18.3 meter pool fire fueled with JP-4 aviation fuel. A calorimeter 1.4 m in diameter by 6.1 m long was used to examine the thermal input to a relatively large, massive object. An examination of temperature and heat flux data emphasizes the effect of even low wind conditions on the overall structure of the fire. In an attempt to examine the thermal environment in the absence of any disturbances, a 'conditioning signal' was used to extract data during periods of low wind. Heat flux and temperature data obtained from the large pool fire tests is presented and the variation over the surface of the large calorimeter is examined. The application of a conditioning signal is used to reduce the wind induced variance in the heat flux data.

  3. The Charge Form Factor of the Neutron at Low Momentum Transfer from the $^{2}\\vec{\\rm H}(\\vec{\\rm e},{\\rm e}'{\\rm n}){\\rm p}$ Reaction

    E-print Network

    E. Geis; V. Ziskin; T. Akdogan; H. Arenhoevel; R. Alarcon; W. Bertozzi; E. Booth; T. Botto; J. Calarco; B. Clasie; C. B. Crawford; A. DeGrush; T. W. Donnelly; K. Dow; M. Farkhondeh; R. Fatemi; O. Filoti; W. Franklin; H. Gao; S. Gilad; D. Hasell; P. Karpius; M. Kohl; H. Kolster; T. Lee; A. Maschinot; J. Matthews; K. McIlhany; N. Meitanis; R. G. Milner; J. Rapaport; R. P. Redwine; J. Seely; A. Shinozaki; S. Sirca; A. Sindile; E. Six; T. Smith; M. Steadman; B. Tonguc; C. Tschalaer; E. Tsentalovich; W. Turchinetz; Y. Xiao; W. Xu; C. Zhang; Z. Zhou; T. Zwart

    2008-04-08

    We report new measurements of the neutron charge form factor at low momentum transfer using quasielastic electrodisintegration of the deuteron. Longitudinally polarized electrons at an energy of 850 MeV were scattered from an isotopically pure, highly polarized deuterium gas target. The scattered electrons and coincident neutrons were measured by the Bates Large Acceptance Spectrometer Toroid (BLAST) detector. The neutron form factor ratio $G^{n}_{E}/G^{n}_{M}$ was extracted from the beam-target vector asymmetry $A_{ed}^{V}$ at four-momentum transfers $Q^{2}=0.14$, 0.20, 0.29 and 0.42 (GeV/c)$^{2}$.

  4. Effect of slip velocity and heat transfer on the condensed phase momentum flux of supersonic nozzle flows

    SciTech Connect

    Sherif, S.A.; Lear, W.E.; Winowich, N.S. [Univ. of Florida, Gainesville, FL (United States). Dept. of Mechanical Engineering

    1994-12-31

    One of the methods used for industrial cleansing applications employs a mixture of gaseous nitrogen and liquid water injected upstream of a converging-diverging nozzle located at the end of a straight wand assembly. The idea is to get the mixture to impact the surface at the maximum momentum flux possible in order to maximize the cleansing effectiveness. This paper presents an analysis geared towards this application in which the effects of slip and heat transfer between the gas and liquid phase are present. The model describes the liquid momentum flux (considered a figure of merit for cleansing) under a host of design conditions.

  5. T Tauri Angular Momentum Loss via Large Scale Eruptive Flaring Events

    NASA Astrophysics Data System (ADS)

    Aarnio, Alicia N.; Stassun, Keivan G.; Matt, Sean P.

    2009-02-01

    The Chandra Orion Ultradeep Project observed hundreds of T Tauri stars undergoing highly energetic X-ray flare events. Analysis of the X-ray flare decay slopes of the most energetic flares resulted in the suprising result that the magnetic loop structures involved in the flare are on the order of tens of stellar radii in length. Do these large loops represent magnetospheric accretion structures or, using a solar analogue, do they represent the eruptive flare predecessors of extreme ``coronal mass ejections'' (CMEs)? We have modeled the spectral energy distributions of this sample and find that the majority lack circumstellar disk material: these are weak-lined T Tauri stars with extremely large flares. This surprising result is the impetus for detailed analysis of the mass and angular momentum shed during events of this magnitude. Work is in progress to model a wider distribution of reconnection event energies and place the results into context with observations.

  6. Increased heat transfer to elliptical leading edges due to spanwise variations in the freestream momentum: Numerical and experimental results

    NASA Technical Reports Server (NTRS)

    Rigby, D. L.; Vanfossen, G. J.

    1992-01-01

    A study of the effect of spanwise variation in momentum on leading edge heat transfer is discussed. Numerical and experimental results are presented for both a circular leading edge and a 3:1 elliptical leading edge. Reynolds numbers in the range of 10,000 to 240,000 based on leading edge diameter are investigated. The surface of the body is held at a constant uniform temperature. Numerical and experimental results with and without spanwise variations are presented. Direct comparison of the two-dimensional results, that is, with no spanwise variations, to the analytical results of Frossling is very good. The numerical calculation, which uses the PARC3D code, solves the three-dimensional Navier-Stokes equations, assuming steady laminar flow on the leading edge region. Experimentally, increases in the spanwise-averaged heat transfer coefficient as high as 50 percent above the two-dimensional value were observed. Numerically, the heat transfer coefficient was seen to increase by as much as 25 percent. In general, under the same flow conditions, the circular leading edge produced a higher heat transfer rate than the elliptical leading edge. As a percentage of the respective two-dimensional values, the circular and elliptical leading edges showed similar sensitivity to span wise variations in momentum. By equating the root mean square of the amplitude of the spanwise variation in momentum to the turbulence intensity, a qualitative comparison between the present work and turbulent results was possible. It is shown that increases in leading edge heat transfer due to spanwise variations in freestream momentum are comparable to those due to freestream turbulence.

  7. ANGULAR MOMENTUM TRANSFER AND LACK OF FRAGMENTATION IN SELF-GRAVITATING ACCRETION FLOWS

    SciTech Connect

    Begelman, Mitchell C. [Also at Department of Astrophysical and Planetary Sciences, University of Colorado at Boulder, CO (United States); Shlosman, Isaac, E-mail: mitch@jila.colorado.edu, E-mail: shlosman@pa.uky.edu

    2009-09-01

    Rapid inflows associated with early galaxy formation lead to the accumulation of self-gravitating gas in the centers of proto-galaxies. Such gas accumulations are prone to nonaxisymmetric instabilities, as in the well known Maclaurin sequence of rotating ellipsoids, which are accompanied by a catastrophic loss of angular momentum (J). Self-gravitating gas is also intuitively associated with star formation. However, recent simulations of the infall process display highly turbulent continuous flows. We propose that J-transfer, which enables the inflow, also suppresses fragmentation. Inefficient J loss by the gas leads to decay of turbulence, triggering global instabilities and renewed turbulence driving. Flow regulated in this way is stable against fragmentation, while staying close to the instability threshold for bar formation-thick self-gravitating disks are prone to global instabilities before they become unstable locally. On smaller scales, the fraction of gravitationally unstable matter swept up by shocks in such a flow is a small and decreasing function of the Mach number. We conclude counterintuitively that gas able to cool down to a small fraction of its virial temperature will not fragment as it collapses. This provides a venue for supermassive black holes to form via direct infall, without the intermediary stage of forming a star cluster. Some black holes could have formed or grown in massive halos at low redshifts. Thus the fragmentation is intimately related to J redistribution within the system: it is less dependent on the molecular/metal cooling but is conditioned by the ability of the flow to develop virial, supersonic turbulence.

  8. Differential, integral, and momentum-transfer cross sections for elastic electron scattering by neon - 5 to 100 eV

    NASA Technical Reports Server (NTRS)

    Register, D. F.; Trajmar, S.

    1984-01-01

    Relative elastic-scattering differential cross sections were measured in the 5-100-eV impact energy and 10-145 deg angular ranges. Normalization of these cross sections was achieved by utilizing accurate total electron-scattering cross sections. A phase-shift analysis of the angular distributions in terms of real phase shifts has been carried out. From the differential cross sections, momentum-transfer cross sections were obtained and the values of the critical energy and angle were established (associated with the lowest value of the differential cross section) as 62.5 + or - 2.5 eV and 101.7 deg + or - 1.5 deg, respectively. The present phase shifts, the critical parameters, and differential, integral, and momentum-transfer cross sections are compared to previous experimental and theoretical results. The error associated with the present data is about 10 percent.

  9. Damping of confined modes in a ferromagnetic thin insulating film: angular momentum transfer across a nanoscale field-defined interface.

    PubMed

    Adur, Rohan; Du, Chunhui; Wang, Hailong; Manuilov, Sergei A; Bhallamudi, Vidya P; Zhang, Chi; Pelekhov, Denis V; Yang, Fengyuan; Hammel, P Chris

    2014-10-24

    We observe a dependence of the damping of a confined mode of precessing ferromagnetic magnetization on the size of the mode. The micron-scale mode is created within an extended, unpatterned yttrium iron garnet film by means of the intense local dipolar field of a micromagnetic tip. We find that the damping of the confined mode scales like the surface-to-volume ratio of the mode, indicating an interfacial damping effect (similar to spin pumping) due to the transfer of angular momentum from the confined mode to the spin sink of ferromagnetic material in the surrounding film. Though unexpected for insulating systems, the measured intralayer spin-mixing conductance g_??=5.3×10(19)??m(-2) demonstrates efficient intralayer angular momentum transfer. PMID:25379927

  10. Damping of Confined Modes in a Ferromagnetic Thin Insulating Film: Angular Momentum Transfer across a Nanoscale Field-Defined Interface

    NASA Astrophysics Data System (ADS)

    Adur, Rohan; Du, Chunhui; Wang, Hailong; Manuilov, Sergei A.; Bhallamudi, Vidya P.; Zhang, Chi; Pelekhov, Denis V.; Yang, Fengyuan; Hammel, P. Chris

    2014-10-01

    We observe a dependence of the damping of a confined mode of precessing ferromagnetic magnetization on the size of the mode. The micron-scale mode is created within an extended, unpatterned yttrium iron garnet film by means of the intense local dipolar field of a micromagnetic tip. We find that the damping of the confined mode scales like the surface-to-volume ratio of the mode, indicating an interfacial damping effect (similar to spin pumping) due to the transfer of angular momentum from the confined mode to the spin sink of ferromagnetic material in the surrounding film. Though unexpected for insulating systems, the measured intralayer spin-mixing conductance g??=5.3×1019 m-2 demonstrates efficient intralayer angular momentum transfer.

  11. Momentum-Transfer and Inelastic-Collision Cross Sections for Electrons in O2, CO, and CO2

    Microsoft Academic Search

    R. D. Hake; A. V. Phelps

    1967-01-01

    Momentum-transfer and inelastic-collision cross sections for electrons in O2, CO, and CO2 are calculated from measured values of the electron drift velocity, characteristic energy, attachment coefficient, and ionization coefficient. The experimental data for O2 are most consistent with vibrational excitation cross sections consisting of a series of resonances located at the vibrational energy levels of the negative ion and having

  12. On-demand Overlay Networks for Large Scientific Data Transfers

    SciTech Connect

    Ramakrishnan, Lavanya; Guok, Chin; Jackson, Keith; Kissel, Ezra; Swany, D. Martin; Agarwal, Deborah

    2009-10-12

    Large scale scientific data transfers are central to scientific processes. Data from large experimental facilities have to be moved to local institutions for analysis or often data needs to be moved between local clusters and large supercomputing centers. In this paper, we propose and evaluate a network overlay architecture to enable highthroughput, on-demand, coordinated data transfers over wide-area networks. Our work leverages Phoebus and On-demand Secure Circuits and AdvanceReservation System (OSCARS) to provide high performance wide-area network connections. OSCARS enables dynamic provisioning of network paths with guaranteed bandwidth and Phoebus enables the coordination and effective utilization of the OSCARS network paths. Our evaluation shows that this approach leads to improved end-to-end data transfer throughput with minimal overheads. The achievedthroughput using our overlay was limited only by the ability of the end hosts to sink the data.

  13. The mass and angular momentum distribution of simulated massive early-type galaxies to large radii

    NASA Astrophysics Data System (ADS)

    Wu, Xufen; Gerhard, Ortwin; Naab, Thorsten; Oser, Ludwig; Martinez-Valpuesta, Inma; Hilz, Michael; Churazov, Eugene; Lyskova, Natalya

    2014-03-01

    We study the dark and luminous mass distributions, circular velocity curves (CVCs), line-of-sight kinematics and angular momenta for a sample of 42 cosmological zoom simulations of galaxies with stellar masses from 2.0 × 1010 to 3.4 × 1011 M? h-1. Using a temporal smoothing technique, we are able to reach large radii. We find the following. The dark matter halo density profiles outside a few kpc follow simple power-law models, with flat dark matter CVCs for lower mass systems, and rising CVCs for high-mass haloes. The projected stellar density distributions at large radii can be fitted by Sérsic functions with n ? 10, larger than for typical early-type galaxies (ETGs). The massive systems have nearly flat total (luminous plus dark matter) CVCs at large radii, while the less massive systems have mildly decreasing CVCs. The slope of the circular velocity at large radii correlates with circular velocity itself. The dark matter fractions within the projected stellar half-mass radius Re are in the range 15-30 per cent and increase to 40-65 per cent at 5Re. Larger and more massive galaxies have higher dark matter fractions. The fractions and trends with mass and size are in agreement with observational estimates, even though the stellar-to-total mass ratio is ˜2-3 times higher than estimated for ETGs. The short axes of simulated galaxies and their host dark matter haloes are well aligned and their short-to-long axis ratios are correlated. The stellar root mean square velocity vrms(R) profiles are slowly declining, in agreement with planetary nebulae observations in the outer haloes of most ETGs. The line-of-sight velocity fields {bar{v}} show that rotation properties at small and large radii are correlated. Most radial profiles for the cumulative specific angular momentum parameter ?(R) are nearly flat or slightly rising, with values in [0.06, 0.75] from 2Re to 5Re. A few cases show local maxima in |{bar{v}}|/? (R). These properties agree with observations of ETGs at large radii. Stellar mass, ellipticity at large radii ?(5Re) and ?(5Re) are correlated: the more massive systems have less angular momentum and are rounder, as for observed ETGs. More massive galaxies with a large fraction of accreted stars have radially anisotropic velocity distributions outside Re. Tangential anisotropy is seen only for galaxies with high fraction of in situ stars.

  14. Heat and Momentum Transfer Studies in High Reynolds Number Wavy Films at Normal and Reduced Gravity Conditions

    NASA Technical Reports Server (NTRS)

    Balakotaiah, V.

    1996-01-01

    We examined the effect of the gas flow on the liquid film when the gas flows in the countercurrent direction in a vertical pipe at normal gravity conditions. The most dramatic effect of the simultaneous flow of gas and liquid in pipes is the greatly increased transport rates of heat, mass, and momentum. In practical situations this enhancement can be a benefit or it can result in serious operational problems. For example, gas-liquid flow always results in substantially higher pressure drop and this is usually undesirable. However, much higher heat transfer coefficients can be expected and this can obviously be of benefit for purposes of design. Unfortunately, designers know so little of the behavior of such two phase systems and as a result these advantages are not utilized. Due to the complexity of the second order boundary model as well as the fact that the pressure variation across the film is small compared to the imposed gas phase pressure, the countercurrent gas flow affect was studied for the standard boundary layer model. A different stream function that can compensate the shear stress affect was developed and this stream function also can predict periodic solutions. The discretized model equations were transformed to a traveling wave coordinate system. A stability analysis of these sets of equations showed the presence of a Hopf bifurcation for certain values of the traveling wave velocity and the shear stress. The Hopf celerity was increased due to the countercurrent shear. For low flow rate the increases of celerity are more than for the high flow rate, which was also observed in experiments. Numerical integration of a traveling wave simplification of the model also predicts the existence of chaotic large amplitude, nonperiodic waves as observed in the experiments. The film thickness was increased by the shear.

  15. Quantum Information Transfer from Spin to Orbital Angular Momentum of Photons

    Microsoft Academic Search

    Eleonora Nagali; Fabio Sciarrino; Francesco de Martini; Lorenzo Marrucci; Bruno Piccirillo; Ebrahim Karimi; Enrico Santamato

    2009-01-01

    The optical ``spin-orbit'' coupling occurring in a suitably patterned nonuniform birefringent plate known as a ``q plate'' allows entangling the polarization of a single photon with its orbital angular momentum (OAM). This process, in turn, can be exploited for building a bidirectional ``spin-OAM interface,'' capable of transposing the quantum information from the spin to the OAM degree of freedom of

  16. On the angular momentum transferred during electromagnetic energy absorption and emission

    Microsoft Academic Search

    R. Klíma

    1974-01-01

    In the framework of classical electrodynamics, the angular momentum transported into (and\\/or from) a volume bounded by a rotational surface is derived. The dependences of electromagnetic field on space and time, and also the electromagnetic properties of the interacting masses are arbitrary. The results may be useful for the theory of toroidal currents induced by high-frequency heating of plasmas. A

  17. Large Quantum imaging of nonlocal spatial correlations induced by orbital angular momentum

    E-print Network

    Adam R. Altman; Kahraman G. Köprülü; Eric Corndorf; Prem Kumar; Geraldo A. Barbosa

    2004-09-26

    Through scanned coincidence counting, we probe the quantum image produced by parametric down conversion with a pump beam carrying orbital angular momentum. Nonlocal spatial correlations are manifested through splitting of the coincidence spot into two.

  18. Orbital angular momentum (OAM) multiplexing in free-space optical data transfer

    Microsoft Academic Search

    Jiao Lin; Xiao-Cong Yuan; Shaohua Tao

    2006-01-01

    In the optical wireless communication systems proposed by Gibson, et al, the information is encoded as states of orbital angular momentum (OAM) of light and the transmitter unit can produce laser beam with single OAM-state in a time-slot. Recently we have proved that it is possible to generate multiple OAM-states simultaneously by single spatial light modulator. This method is adopted

  19. Higher-twist contributions to the transverse momentum broadening in semi-inclusive deep inelastic scattering off large nuclei

    E-print Network

    Jia Jun Zhang; Jian-Hua Gao; Xin-Nian Wang

    2014-11-20

    Multiple scattering leads to transverse momentum broadening of the struck quark in semi-inclusive deeply inelastic scatterings (SIDIS). Nuclear broadening of the transverse momentum squared at the leading twist is determined by the twist-four collinear quark-gluon correlation function of the target nucleus that is in turn related to the jet transport parameter inside the nuclear medium. The twist-six contributions to the transverse momentum broadening are calculated as power corrections $\\sim 1/Q^2$. Such power corrections are found to have no extra nuclear enhancement beyond the twist-four matrix elements and are determined by the nuclear modification of collinear parton distribution and correlation functions. They become important for an accurate extraction of the jet transport parameter inside large nuclei and its scale evolution at intermediate values of the hard scale $Q^2$.

  20. Higher-twist contributions to the transverse momentum broadening in semi-inclusive deep inelastic scattering off large nuclei

    NASA Astrophysics Data System (ADS)

    Zhang, Jia Jun; Gao, Jian-Hua; Wang, Xin-Nian

    2015-01-01

    Multiple scattering leads to transverse momentum broadening of the struck quark in semi-inclusive deeply inelastic scatterings. Nuclear broadening of the transverse momentum squared at the leading twist is determined by the twist-four collinear quark-gluon correlation function of the target nucleus that is in turn related to the jet transport parameter inside the nuclear medium. The twist-six contributions to the transverse momentum broadening are calculated as power corrections ˜1 /Q2. Such power corrections are found to have no extra nuclear enhancement beyond the twist-four matrix elements and are determined by the nuclear modification of collinear parton distribution and correlation functions. They become important for an accurate extraction of the jet transport parameter inside large nuclei and its scale evolution at intermediate values of the hard scale Q2.

  1. Heat and momentum transfer model studies applicable to once-through, forced convection potassium boiling

    NASA Technical Reports Server (NTRS)

    Sabin, C. M.; Poppendiek, H. F.

    1971-01-01

    A number of heat transfer and fluid flow mechanisms that control once-through, forced convection potassium boiling are studied analytically. The topics discussed are: (1) flow through tubes containing helical wire inserts, (2) motion of droplets entrained in vapor flow, (3) liquid phase distribution in boilers, (4) temperature distributions in boiler tube walls, (5) mechanisms of heat transfer regime change, and (6) heat transfer in boiler tubes. Whenever possible, comparisons of predicted and actual performances are made. The model work presented aids in the prediction of operating characteristics of actual boilers.

  2. Oliver E. Buckley Condensed Matter Prize Lecture: Transfer of spin momentum between magnets: its genesis and prospect

    NASA Astrophysics Data System (ADS)

    Slonczewski, John

    2013-03-01

    Consider two nanoscopic monodomain magnets connected by a spacer that is composed of a non-magnetic metal or a tunnel barrier. Any externally applied electric current flowing through these three layers contributes tiny pseudo-torques to both magnetic moments (J. S. 1989). Such a weak spin-transfer torque (STT) may counteract and overcome a comparably small torque caused by viscous dissipation (L. Berger 1996; J. S. 1996). Any initial motion (e. g. excited by ambient temperature) of one moment (or both), may grow in amplitude and culminate in steady precession or a transient switch to a new direction of static equilibrium. In a memory element, the STT effect writes 0 or 1 in a magnetic-tunnel junction. Indeed, world-wide developments of memory arrays and radio-frequency oscillators utilizing current-driven STT today enjoy a nine-digit dollar commitment. But the fact that transfer of each half-unit of spin momentum h/4? through a barrier requires the transfer of at least one unit of electric charge limits its efficiency. Arguably, STT should also arise from the flow of external heat, in either direction, between an insulating magnet, of ferrite or garnet (e. g. YIG) composition, and a metallic spacer (J. S. 2010). Whenever s-d exchange annihilates a hot magnon at the insulator/metal-spacer interface, it transfers one unit h/2? of spin momentum to the spacer. Conduction electrons within the spacer will transport this spin momentum to the second magnet without requiring an electric current. Such a thermagnonic method, modestly powered by a Joule-effect heater, can substantially increase the efficiency of STT. Support for this prediction comes from (1) an estimate of the sd-exchange coefficient from data on spin relaxation in magnetically dilute (Cu,Ag,Au):Mn alloys; (2) a DFT computation (J. Xiao et al 2010); and (3) most persuasively, data from spin pumping driven across a YIG/Au interface by ferromagnetic resonance (B. Heinrich et al 2011; C. Burrowes et al 2012).

  3. A stability-dependent parametrization of transfer coefficients for momentum and heat over polar sea ice to be used in climate models

    NASA Astrophysics Data System (ADS)

    Lüpkes, Christof; Gryanik, Vladimir M.

    2015-01-01

    The interaction between sea ice and atmosphere depends strongly on the near-surface transfer coefficients for momentum and heat. A parametrization of these coefficients is developed on the basis of an existing parametrization of drag coefficients for neutral stratification that accounts for form drag caused by the edges of ice floes and melt ponds. This scheme is extended to better account for the dependence of surface wind on limiting cases of high and low ice concentration and to include near-surface stability effects over open water and ice on form drag. The stability correction is formulated on the basis of stability functions from Monin-Obukhov similarity theory and also using the Louis concept with stability functions depending on the bulk Richardson numbers. Furthermore, a parametrization is proposed that includes the effect of edge-related turbulence also on heat transfer coefficients. The parametrizations are available in different levels of complexity. The lowest level only needs sea ice concentration and surface temperature as input, while the more complex level needs additional sea ice characteristics. An important property of our parametrization is that form drag caused by ice edges depends on the stability over both ice and water which is in contrast to the skin drag over ice. Results of the parametrization show that stability has a large impact on form drag and, thereby, determines the value of sea ice concentration for which the transfer coefficients reach their maxima. Depending on the stratification, these maxima can occur anywhere between ice concentrations of 20 and 80%.

  4. Orbital angular momentum (OAM) multiplexing in free-space optical data transfer

    NASA Astrophysics Data System (ADS)

    Lin, Jiao; Yuan, Xiao-Cong; Tao, Shaohua

    2006-08-01

    In the optical wireless communication systems proposed by Gibson, et al, the information is encoded as states of orbital angular momentum (OAM) of light and the transmitter unit can produce laser beam with single OAM-state in a time-slot. Recently we have proved that it is possible to generate multiple OAM-states simultaneously by single spatial light modulator. This method is adopted in our free-space optical wireless communication system and these OAM-states can be detected in the receiving unit by a computer-generated hologram. Hence, the transmission capacity is enhanced significantly without increasing the complexity of system.

  5. The Proton Electromagnetic Form Factor $F_2$ and Quark Orbital Angular Momentum

    E-print Network

    Pankaj Jain; John P. Ralston

    2003-06-21

    We analyze the proton electromagnetic form factor ratio $R(Q^{2})=QF_2(Q^{2})/F_1(Q^{2})$ as a function of momentum transfer $Q^{2}$ within perturbative QCD. We find that the prediction for $R(Q^{2})$ at large momentum transfer $Q$ depends on the exclusive quark wave functions, which are unknown. For a wide range of wave functions we find that $ QF_2/F_1 \\sim\\ const$ at large momentum transfer, in agreement with recent JLAB data.

  6. Operational Momentum in Large-Number Addition and Subtraction by 9-Month-Olds

    ERIC Educational Resources Information Center

    McCrink, Koleen; Wynn, Karen

    2009-01-01

    Recent studies on nonsymbolic arithmetic have illustrated that under conditions that prevent exact calculation, adults display a systematic tendency to overestimate the answers to addition problems and underestimate the answers to subtraction problems. It has been suggested that this "operational momentum" results from exposure to a…

  7. Momentum transfer driven textural changes of CeO{sub 2} thin films

    SciTech Connect

    Van Steenberge, S., E-mail: sigelinde.vansteenberge@ugent.be; Leroy, W. P.; Depla, D. [Department of Solid State Sciences, Ghent University, Krijgslaan 281/S1, 9000 Ghent (Belgium); Hubin, A. [Department of Materials and Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium)

    2014-09-15

    The influence of the target erosion depth on the film texture was investigated during DC reactive magnetron sputter deposition of CeO{sub 2} thin films. Three fluxes towards the substrate surface (the relative negative oxygen ion flux, the material flux, and the energy flux) were measured and related to the ongoing erosion of a cerium target. As the deposition rate increased for more eroded targets, both the energy flux and the negative ion flux decreased. Cerium oxide thin films that were deposited at different target erosion states, exhibited a change in preferential crystalline orientation from [200] to [111]. This textural change cannot be explained in terms of the energy per arriving atom concept. Instead, it is shown that the momentum of the high energetic negative ions is an essential condition to clarify the witnessed trends.

  8. Direct measurements of wind-water momentum coupling in a marsh with emergent vegetation and implications for gas transfer estimates

    NASA Astrophysics Data System (ADS)

    Tse, I.; Poindexter, C.; Variano, E. A.

    2013-12-01

    Among the numerous ecological benefits of restoring wetlands is carbon sequestration. As emergent vegetation thrive, atmospheric CO2 is removed and converted into biomass that gradually become additional soil. Forecasts and management for these systems rely on accurate knowledge of gas exchange between the atmosphere and the wetland surface waters. Our previous work showed that the rate of gas transfer across the air-water interface is affected by the amount of water column mixing caused by winds penetrating through the plant canopy. Here, we present the first direct measurements of wind-water momentum coupling made within a tule marsh. This work in Twitchell Island in the California Delta shows how momentum is imparted into the water from wind stress and that this wind stress interacts with the surface waters in an interesting way. By correlating three-component velocity signals from a sonic anemometer placed within the plant canopy with data from a novel Volumetric Particle Imager (VoPI) placed in the water, we measure the flux of kinetic energy through the plant canopy and the time-scale of the response. We also use this unique dataset to estimate the air-water drag coefficient using an adjoint method.

  9. Meson-exchange currents and final-state interactions in quasielastic electron scattering at high momentum transfers

    SciTech Connect

    Amaro, J. E.; Maieron, C. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Granada, Granada E-18071 (Spain); Barbaro, M. B. [Dipartimento di Fisica Teorica, Universita di Torino and INFN, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Caballero, J. A. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad de Sevilla, Apdo.1065, E-41080 Sevilla (Spain); Donnelly, T. W. [Center for Theoretical Physics, Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Udias, J. M. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040, Madrid (Spain)

    2010-01-15

    The effects of meson-exchange currents (MEC) are computed for the one-particle one-hole transverse response function for finite nuclei at high momentum transfers q in the region of the quasi-elastic peak. A semirelativistic shell model is used for the one-particle-emission (e,e{sup '}) reaction. Relativistic effects are included using relativistic kinematics, performing a semirelativistic expansion of the current operators, and using the Dirac-equation-based (DEB) form of the relativistic mean-field potential for the final states. It is found that final-state interactions (FSI) produce an important enhancement of the MEC in the high-energy tail of the response function for q>=1 GeV/c. The combined effect of MEC and FSI goes away when other models of the FSI, not based on the DEB potential, are employed.

  10. Meson-exchange currents and final-state interactions in quasielastic electron scattering at high momentum transfers

    E-print Network

    J. E. Amaro; M. B. Barbaro; J. A. Caballero; T. W. Donnelly; C. Maieron; J. M. Udias

    2009-06-30

    The effects of meson-exchange currents (MEC) are computed for the one-particle one-hole transverse response function for finite nuclei at high momentum transfers $q$ in the region of the quasielastic peak. A semi-relativistic shell model is used for the one-particle-emission $(e,e')$ reaction. Relativistic effects are included using relativistic kinematics, performing a semi-relativistic expansion of the current operators and using the Dirac-equation-based (DEB) form of the relativistic mean field potential for the final states. It is found that final-state interactions (FSI) produce an important enhancement of the MEC in the high-energy tail of the response function for $q\\geq 1$ GeV/c. The combined effect of MEC and FSI goes away when other models of the FSI, not based on the DEB potential, are employed.

  11. Towards a Precision Measurement of Parity-Violating e-p Elastic Scattering at Low Momentum Transfer

    SciTech Connect

    Jie Pan

    2012-05-31

    The goal of the Q-weak experiment is to make a measurement of the proton's weak charge Q{sub W}{sup p} = 1 - 4 sin{sup 2}({theta}{sub W}) to an accuracy of {approx} 4%. This would represent a {approx} 0.3% determination of the weak mixing angle sin{sup 2}({theta}{sub W}) at low energy. The measurement may be used for a precision test of the Standard Model (SM) prediction on the running of sin{sup 2}({theta}{sub W}) with energy scale. The Q-weak experiment operates at Thomas Jefferson National Accelerator Facility (Jefferson Lab). The experiment determines Q{sub W}{sup p} by measuring the parity violating asymmetry in elastic electron-proton scattering at low momentum transfer Q{sup 2} = 0.026 (GeV/c){sup 2} and forward angles (?8 degrees). The anticipated size of the asymmetry, based on the SM, is about 230 parts per billion (ppb). With the proposed accuracy, the experiment may probe new physics beyond Standard Model at the TeV scale. This thesis focuses on my contributions to the experiment, including track reconstruction for momentum transfer determination of the scattering process, and the focal plane scanner, a detector I designed and built to measure the flux profile of scattered electrons on the focal plane of the Q-weak spectrometer to assist in the extrapolation of low beam current tracking results to high beam current. Preliminary results from the commissioning and the first run period of the Q-weak experiment are reported and discussed.

  12. Generation of High-Energy Photons with Large Orbital Angular Momentum by Compton Backscattering

    SciTech Connect

    Jentschura, U. D. [Department of Physics, Missouri University of Science and Technology, Rolla, Missouri 65409 (United States); Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany); Serbo, V. G. [Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany); Novosibirsk State University, Pirogova 2, 630090, Novosibirsk (Russian Federation)

    2011-01-07

    Usually, photons are described by plane waves with a definite 4-momentum. In addition to plane-wave photons, ''twisted photons'' have recently entered the field of modern laser optics; these are coherent superpositions of plane waves with a defined projection ({h_bar}/2{pi})m of the orbital angular momentum onto the propagation axis, where m is an integer. In this Letter, we show that it is possible to produce high-energy twisted photons by Compton backscattering of twisted laser photons off ultrarelativistic electrons. Such photons may be of interest for experiments related to the excitation and disintegration of atoms and nuclei, and for studying the photoeffect and pair production off nuclei in previously unexplored experimental regimes.

  13. The design, construction, and instrumentation of a chamber to study heat, mass, and momentum transfer from humid air to metal under conditions of frosting and free convection

    E-print Network

    Hutchison, James P

    1961-01-01

    THE DESIGN? CONSTRUCTION? AND INSTRUMENTATION OF A CEAMSER TO STUDY HEAT, MASS? AND MOSNTUM TRANSFER FROM HUMID AIR TO METAL UNDER CONDITIONS OF FROSTING AND FREE CONVECTION A Thesis By James P. Hutchison Submitted to the Graduate School..., AND MOMENTUM TRANSFER FROM HUMID AIR TO METAL UNDER CONDITIONS OF FROSTING AND FREE CONVECTION A Thesis By James P. Hutchison Approved as to Style and Content: Chairman of Committee Head of Departm t + gkA4; August 1961 ACKNOWLEDGEMENT S The writer...

  14. Evolution of single B-type stars with a large angular momentum content

    NASA Astrophysics Data System (ADS)

    Granada, Anahí; Haemmerlé, Lionel

    2014-10-01

    Context. The Geneva Stellar Evolution Group has recently presented an extended database of rotating stellar models at three different metallicities for nine different initial rotation parameters and ten different masses corresponding to spectral types from early-F to late-O. With these grids we have contributed to the understanding of the evolution of single rotating stars, and we intend to use them to produce synthetic stellar populations that fully account for the effects of stellar rotation. However, up to now we still lacked stellar evolutionary tracks that rotate close to the critical limit during the whole main-sequence (MS) phase. This occurs because the flat internal profile of rotation imposed at the zero-age main sequence (ZAMS) is modified by the action of meridional currents immediately after the ZAMS, causing the surface rotational velocity to decrease abruptly until it reaches a quasi-stationary state. Aims: We compute stellar models with non-solid rotation at the ZAMS, which allows us to obtain stellar evolutionary tracks with a larger content of angular momentum that rotate close to the breakup limit throughout the whole MS. Methods: We produced stellar models by removing the assumption that stars rotate as solid bodies at the ZAMS. We obtained the stellar structure at the ZAMS with a differentially rotating profile for three different metallicities by performing pre-MS calculations and by proposing ad hoc initial rotational profiles. We then computed the MS evolution and later phases of stellar evolution of these models, which attain rotational equatorial velocities close to the critical limit throughout their whole MS phase. Results: Stellar models with solid rotation at the ZAMS adequately represent the overall characteristics and evolution of differentially rotating models of identical angular momentum content, but with a lower initial surface rotational velocity rate, at Z = 0.014, Z = 0.006, and Z = 0.002. For models with solid rotation at the ZAMS we therefore recommend to use as the initial rotational rate the values derived once the quasi-stationary state is reached, that is, after the abrupt decrease in surface velocity. By producing stellar structures at the ZAMS with differentially rotating profiles and larger angular momentum content than in our previous works, we obtain models that rotate close to the critical limit throughout the whole MS. These models have a longer MS lifetime and a higher surface chemical enrichment already at the end of the MS, particularly at Z = 0.002. Interestingly, the initial equatorial rotational velocities are virtually metallicity independent for all stellar models we computed in the B-type star range with the same mass and angular momentum content at the ZAMS. If, as some observational evidence indicates, B-type stars at Z = 0.002 rotate with a higher equatorial velocity at the ZAMS than stars with Z = 0.014, our finding would indicate that the angular momentum content of B-type stars in the SMC is higher than their Galactic counterparts. Tables 1-4 are available in electronic form at http://www.aanda.org

  15. Experimental realization of large-alphabet quantum key distribution protocol using orbital angular momentum entanglement

    E-print Network

    Shengmei Zhao; Longyan Gong; Yongqiang Li; Hua Yang; Yubo Sheng; Xiaoliang Dong; Fei Cao; Baoyu Zheng

    2012-05-04

    We experimentally demonstrate a quantum key distribution (QKD) protocol using photon pairs entangled in orbit angular momentum (OAM). In our protocol, Alice and Bob modulate their OAM states on each entangled pair with spatial light modulators (SLMs), respectively. Alice uses a fixed phase hologram in her SLM, while Bob designs $N$ different suitable phase holograms and uses them to represent his $N$-based information in his SLM. With coincidences, Alice can fully retrieve the key stream sent by Bob without information reconciliation or privacy amplification. We report the experiment results with N=3 and the sector states with OAM eigenmodes l=1 and l=-1. Our experiment shows that the coincidence rates are in relatively distinct value regions for the three different key elements. Alice could recover fully Bob's keys by the protocol. Finally, we discuss the security of the protocol both form the light way and against the general attacks.

  16. Realizing high-quality, ultra-large momentum states using semiconductor hyperbolic metamaterials

    E-print Network

    Campione, Salvatore; Luk, Ting S; Sinclair, Michael B

    2015-01-01

    We employ both the effective medium approximation (EMA) and Bloch theory to compare the dispersion properties of semiconductor hyperbolic metamaterials (SHMs) at mid-infrared frequencies and metallic hyperbolic metamaterials (MHMs) at visible frequencies. This analysis reveals the conditions under which the EMA can be safely applied for both MHMs and SHMs. We find that the combination of precise nanoscale layering and the longer infrared operating wavelengths puts the SHMs well within the effective medium limit and, in contrast to MHMs, allows the attainment of very high photon momentum states. In addition, SHMs allow for new phenomena such as ultrafast creation of the hyperbolic manifold through optical pumping. In particular, we examine the possibility of achieving ultrafast topological transitions through optical pumping which can photo-dope appropriately designed quantum wells on the femtosecond time scale.

  17. Anisotropic Fermi Couplings due to Large Unquenched Orbital Angular Momentum: Q-band 1H, 14N and 11B ENDOR of bistrispyrazolylborate Co(II)

    PubMed Central

    Myers, William K.; Scholes, Charles P.; Tierney, David L.

    2009-01-01

    We report Q-band ENDOR of 1H, 14N, and 11B at the g|| extreme of the EPR spectrum of bistrispyrazolylborate Co(II), Co(Tp)2 and two structural analogs. This trigonally symmetric, high-spin (hs) S = 3/2 Co(II) complex shows large unquenched ground–state orbital angular momentum, which leads to highly anisotropic electronic g-values [g|| = 8.48, g? = 1.02]. The large g-anisotropy is shown to result in large dipolar couplings near g|| and uniquely anisotropic 14N Fermi couplings, which arise from spin transferred to the nitrogen 2s orbital (2.2 %) via anti-bonding interactions with singly occupied metal dx2?y2 and dz2 orbitals. Large, well-resolved 1H and 11B dipolar couplings were also observed. Taken in concert with our previous X-band ENDOR measurements at g? (Myers, et al, Inorg. Chem. 2008, 47, 6701–6710), the present data allow a detailed analysis of the dipolar hyperfine tensors of two of the four symmetry distinct protons in the parent molecule. In the substituted analogs, changes in hyperfine coupling due to altered metal-proton distances give further evidence of an anisotropic Fermi contact interaction. For the pyrazolyl 3H proton, the data indicate a 0.2 MHz anisotropic contact interaction and ~ 4 % transfer of spin away from Co(II). Dipolar coupling also dominates for the axial boron atoms, consistent with their distance from the Co(II) ion, and resolved 11B quadrupolar coupling showed ~ 30 % electronic inequivalence between the B-H and B-C sp3 bonds. This is the first comprehensive ENDOR study of any hs Co(II) species and lays the foundation for future development. PMID:19591466

  18. Search for diphoton events with large missing transverse momentum in 7 TeV proton–proton collision data with the ATLAS detector

    E-print Network

    Taylor, Frank E.

    A search for diphoton events with large missing transverse momentum has been performed using proton–proton collision data at ?s = 7 TeV recorded with the ATLAS detector, corresponding to an integrated luminosity of 4.8 ...

  19. Sheep: The First Large Animal Model in Nuclear Transfer Research

    PubMed Central

    Czernik, Marta; Zacchini, Federica; Iuso, Domenico; Scapolo, Pier Augusto

    2013-01-01

    Abstract The scope of this article is not to provide an exhaustive review of nuclear transfer research, because many authoritative reviews exist on the biological issues related to somatic and embryonic cell nuclear transfer. We shall instead provide an overview on the work done specifically on sheep and the value of this work on the greater nuclear transfer landscape. PMID:24033140

  20. JLab Measurement of the 4He Charge Form Factor at Large Momentum Transfers

    SciTech Connect

    Camsonne, Alexandre; Katramatou, A. T.; Olson, M.; Sparveris, Nikolaos; Acha, Armando; Allada, Kalyan; Anderson, Bryon; Arrington, John; Baldwin, Alan; Chen, Jian-Ping; Choi, Seonho; Chudakov, Eugene; Cisbani, Evaristo; Craver, Brandon; Decowski, Piotr; Dutta, Chiranjib; Folts, Edward; Frullani, Salvatore; Garibaldi, Franco; Gilman, Ronald; Gomez, Javier; Hahn, Brian; Hansen, Jens-Ole; Higinbotham, Douglas; Holmstrom, Timothy; Huang, Jian; Iodice, Mauro; Kelleher, Aidan; Khrosinkova, Elena; Kievsky, A.; Kuchina, Elena; Kumbartzki, Gerfried; Lee, Byungwuek; LeRose, John; Lindgren, Richard; Lott, Gordon; Lu, H.; Marcucci, Laura; Margaziotis, Demetrius; Markowitz, Pete; Marrone, Stefano; Meekins, David; Meziani, Zein-Eddine; Michaels, Robert; Moffit, Bryan; Norum, Blaine; Petratos, Gerassimos; Puckett, Andrew; Qian, Xin; Rondon-Aramayo, Oscar; Saha, Arunava; Sawatzky, Bradley; Segal, John; Hashemi, Mitra; Shahinyan, Albert; Solvignon-Slifer, Patricia; Subedi, Ramesh; Suleiman, Riad; Sulkosky, Vincent; Urciuoli, Guido; Viviani, Michele; Wang, Y.; Wojtsekhowski, Bogdan; Yan, X.; Yao, H.; Zhang, W. -M.; Zheng, X.; Zhu, L.

    2014-04-01

    The charge form factor of 4He has been extracted in the range 29 fm-2 <= Q2 <= 77 fm-2 from elastic electron scattering, detecting 4He nuclei and electrons in coincidence with the High Resolution Spectrometers of the Hall A Facility of Jefferson Lab. The results are in qualitative agreement with realistic meson-nucleon theoretical calculations. The data have uncovered a second diffraction minimum, which was predicted in the Q2 range of this experiment, and rule out conclusively long-standing predictions of dimensional scaling of high-energy amplitudes using quark counting.

  1. JLab Measurement of the $^4$He Charge Form Factor at Large Momentum Transfers

    E-print Network

    A. Camsonne; A. T. Katramatou; M. Olson; N. Sparveris; A. Acha; K. Allada; B. D. Anderson; J. Arrington; A. Baldwin; J. -P. Chen; S. Choi; E. Chudakov; E. Cisbani; B. Craver; P. Decowski; C. Dutta; E. Folts; S. Frullani; F. Garibaldi; R. Gilman; J. Gomez; B. Hahn; J. -O. Hansen; D. Higinbotham; T. Holmstrom; J. Huang; M. Iodice; X. Jiang; A. Kelleher; E. Khrosinkova; A. Kievsky; E. Kuchina; G. Kumbartzki; B. Lee; J. J. LeRose; R. A. Lindgren; G. Lott; H. Lu; L. E. Marcucci; D. J. Margaziotis; P. Markowitz; S. Marrone; D. Meekins; Z. -E. Meziani; R. Michaels; B. Moffit; B. Norum; G. G. Petratos; A. Puckett; X. Qian; O. Rondon; A. Saha; B. Sawatzky; J. Segal; M. Shabestari; A. Shahinyan; P. Solvignon; R. R. Subedi; R. Suleiman; V. Sulkosky; G. M. Urciuoli; M. Viviani; Y. Wang; B. B. Wojtsekhowski; X. Yan; H. Yao; W. -M. Zhang; X. Zheng; L. Zhu

    2013-09-20

    The charge form factor of $^$4He has been extracted in the range 29 fm$^{-2}$ $\\le Q^2 \\le 77$ fm$^{-2}$ from elastic electron scattering, detecting $^4$He nuclei and electrons in coincidence with the High Resolution Spectrometers of the Hall A Facility of Jefferson Lab. The results are in qualitative agreement with realistic meson-nucleon theoretical calculations. The data have uncovered a second diffraction minimum, which was predicted in the $Q^2$ range of this experiment, and rule out conclusively long-standing predictions of dimensional scaling of high-energy amplitudes using quark counting.

  2. Scaling behavior in exclusive meson photoproduction from Jefferson Lab at large momentum transfers

    SciTech Connect

    Dey, Biplab [University of Zurich

    2014-07-01

    With the availability of new high-statistics and wide-angle measurements for several exclusive non-?N meson photoproduction channels from Jefferson Lab, we examine the fundamental scaling law of 90° scattering in QCD that was originally derived in the high-energy perturbative limit. The data show scaling to be prominently visible even in the medium-energy domain of 2.5 GeV ?s??2.84??GeV, where s? is the center-of-mass energy. While constituent quark exchange suffices for pseudoscalar mesons, additional gluon exchanges from higher Fock states of the hadronic wave functions appear be needed for vector-meson production. The case of the ?(1020), where two-gluon exchanges are known to dominate, is especially illuminating.

  3. Measurement of the deuteron elastic structure functions at large momentum transfers

    SciTech Connect

    Kathy McCormick

    1999-08-01

    The cross section for elastic electron-deuteron scattering has been measured using the Hall A Facility of Jefferson Laboratory. Scattered electrons and recoiling deuterons were detected in coincidence in the two 4 GeV/c High Resolution Spectrometers (HRS) of Hall A. The deuteron elastic structure functions A(Q{sup 2}) and B(Q{sup 2}) have been extracted from these data. Results for the measurement of A(Q{sup 2}) in the range of 0.7 ? Q{sup 2} ? 6.0 (GeV/c){sup 2} are reported. Results for the magnetic structure function, B(Q{sup 2}), are presented in the range of 0.7 ? Q{sup 2} ? 1.35 (GeV/c){sup 2}. The results for both structure functions are compared to predictions of meson-nucleon based models, both with and without the inclusion of meson-exchange currents. The A(Q{sup 2}) results are compared to predictions of the dimensional scaling quark model and perturbative quantum chromodynamics. The results can provide insights into the transition from meson-nucleon to quark-gluon descriptions of the nuclear two-body system.

  4. Exclusive Photoproduction of Large Momentum-Transfer K and K* Mesons

    E-print Network

    P. Kroll; M. Schuermann; K. Passek; W. Schweiger

    1996-04-18

    The reactions gamma p -> K+ Lambda and gamma p -> K* Lambda are analyzed within perturbative QCD, allowing for diquarks as quasi-elementary constituents of baryons. The diquark-model parameters and the quark-diquark distribution amplitudes of proton and Lambda are taken from previous investigations of electromagnetic baryon form factors and Compton-scattering off protons. Unpolarized differential cross sections and polarization observables are computed for different choices of the K and K* distribution amplitudes. The asymptotic form of the K distribution amplitude (proportional to x1 x2) is found to provide a satisfactory description of the K photoproduction data.

  5. Measurement of Momentum Transfer Coefficients for H2, N2, CO, and CO2 Incident Upon Spacecraft Surfaces

    NASA Technical Reports Server (NTRS)

    Cook, Steven R.; Hoffbauer, Mark A.

    1997-01-01

    Measurements of momentum transfer coefficients were made for gas-surface interactions between the Space Shuttle reaction control jet plume gases and the solar panel array materials to be used on the International Space Station. Actual conditions were simulated using a supersonic nozzle source to produce beams of the gases with approximately the same average velocities as the gases have in the Shuttle plumes. Samples of the actual solar panel materials were mounted on a torsion balance that was used to measure the force exerted on the surfaces by the molecular beams. Measurements were made with H2, N2, CO, and CO2 incident upon the solar array material, Kapton, SiO2-coated Kapton, and Z93-coated Al. The measurements showed that molecules scatter from the surfaces more specularly as the angle of incidence increases and that the scattering behavior has a strong dependence upon both the incident gas and velocity. These results show that for some technical surfaces the simple assumption of diffuse scattering with complete thermal accommodation is entirely inadequate. It is clear that additional measurements are required to produce models that more accurately describe the gas-surface interactions encountered in rarefied flow regimes.

  6. Four Momentum Transfer Discrepancy in the Charged Current pi+ Production in the MiniBooNE: Data versus Theory

    SciTech Connect

    Nowak, Jaroslaw A.; /Louisiana State U.

    2009-09-01

    The MiniBooNE experiment has collected what is currently the world's largest sample of {nu}{sub {mu}} charged current single charged pion (CCl{pi}{sup +}) interactions, roughly 46,000 events. The purity of the CCl{pi}{sup +} sample is 87% making this the purest event sample observed in the MiniBooNE detector. The average energy of neutrinos producing CC{pi}{sup +} interactions in MiniBooNE is about 1 GeV, therefore the study of these events can provide insight into both resonant and coherent pion production processes. In this talk, we will discuss the long-standing discrepancy in four-momentum transfer observed between CC{pi}{sup +} data and existing predictions. Several attempts to address this problem will be presented. Specifically, the Rein-Sehgal model has been extended to include muon mass terms for both resonant and coherent production. Using calculations from, an updated form for the vector form factor has also been adopted. The results of this improved description of CC{pi}{sup +} production will be compared to the high statistics MiniBooNE CC{pi}{sup +} data and several existing parametrizations of the axial vector form factor.

  7. Heat and Momentum Transfer on the Rapid Phase Change of Liquid Induced by Nanosecond-Pulsed Laser Irradiation.

    NASA Astrophysics Data System (ADS)

    Park, Hee Kuwon

    1994-01-01

    This study examines the physics of the liquid -vapor phase transition phenomenon induced by nanosecond -pulsed ultraviolet laser irradiation. This work is concerned with the science and technological applications of the phenomenon of rapid nucleation and explosive vaporization of a liquid in contact with a pulsed-laser heated solid surface. The thermodynamics of the phase transition, the kinetics of collective bubble growth and collapse, and the transient development of pressure field have been investigated experimentally by various fast optical sensing techniques. The purpose of this study is to provide new insight into the physics of the liquid-vapor transition and the interaction between laser and liquid-solid interface. A detailed study on the practical aspects of a novel technological application, the laser cleaning technology, is also included. A model system investigated throughout this work is pure water, methanol, or isopropanol in contact with a solid chromium surface that is heated by ultraviolet KrF excimer laser pulses of nanosecond duration. The dynamics of bubble nucleation, growth, and collapse is studied by optical specular reflectance and scattering probe, which isolates the onset of phase transformation with great accuracy. The thermodynamics of phase transition and metastability of liquid matter have been studied by transient photothermal reflectance probe, which monitors the transient temperature field non-intrusively with nanosecond time resolution. The transient response from the photothermal reflectance probe which utilizes temperature-dependent optical properties of an embedded thin film sensor are coupled with heat transfer modeling results in order to predict the thermodynamic condition for the vaporization in nanosecond time scale. The generation of transient pressure pulses by bubble growth and the effect of static pressure on the phase transition are studied by the piezoelectric transducer probe, photoacoustic probe beam deflection technique, and a high-pressure cell. The onset of phase change introduces a strong acoustic signal that is detected by a piezoelectric transducer and a photoacoustic probe. The information on the temperature and pressure development during the vaporization process determines the heat and momentum transfer in the explosive vaporization process. The pressure production mechanisms in the short-pulsed laser-induced vaporization are studied theoretically and experimentally. It is shown that the collective bubble growth is an effective momentum transfer mechanism to radiate acoustic energy. It is observed that the thermally driven phase change generates pressure waves in the liquid that trigger subsequent acoustic cavitation. The implications of the thermal nucleation on the following cavitation is studied. It has been found that the metastabilized microscopic bubbles can exist for much longer time than the apparent life time, subsequently enhancing the following acoustic cavitation. As an example of technological application of the phenomenon, a practical laser cleaning technique has been studied. A laser-cleaning tool capable of removing surface contaminants such as submicron-sized particulates and organic films has been constructed and implemented in practical use.

  8. The Effect of Large-Scale Structure on the Formation of Disk Galaxies : Specific Angular Momentum Point of View

    NASA Astrophysics Data System (ADS)

    Kim, Ji Hoon

    2015-01-01

    We investigate the correlation between the environment parameters and central surface brightness of disk galaxies in order to study the effect of the large-scale structure on the formation of disk galaxies. In the standard galaxy formation picture, galaxy discs form out of primordial gas due to density fluctuation while conserving its specific angular momentum. The specific angular momentum of the pre-collapse gas is generally assumed to be equal to that of the dark matter, which is acquired by the tidal interactions with the surrounding matter distribution at its proto-halo stage. The difference of specific angular momentum of host dark matter halos is the favored origin for the difference between low surface brightness galaxies (LSBGs) and high surface brightness galaxies (HSBGs) which results in the different evolutionary paths. We utilize broadband photometry data from Simard et al. (2011) to extract the environment parameters and properties of individual galaxies. We calculate central surface brightness (?0) for 1,123,718 galaxies based on absolute magnitude of model disk and exponential disk scale lengths in g'- and r'- bands. We convert g'- and r'-band central surface brightnesses into B-band central surface brightness (?0,B) using conversion from Smith et al. (2002). We classify disk galaxies with ?0,B ? 22.5 mag arcsec-2 as LSBGs while ones with ?0,B < 22.7 mag arcsec-2 as HSBGs.Then we compute a surface galaxy number density estimated from the fifth nearest neighbour galaxies (?5). We are presenting a preliminary result based on our sample selection process and discussing the future prospect for the studies of disk galaxy formation with current and future facilities.

  9. Large-aperture refractive lenses for momentum-resolved spectroscopy with hard X-rays.

    PubMed

    Fukui, Hiroshi; Simon, Markus; Nazmov, Vladimir; Mohr, Jürgen; Evans-Lutterodt, Kenneth; Stein, Aaron; Baron, Alfred Q R

    2013-07-01

    One-dimensional kinoform and prism refractive lenses with large aperture and high transmittance at 22 keV have been investigated. A 12.0 µm focus size (full width at half-maximum) and an effective aperture of 0.85 mm, at a focal length of 705 mm and 21.747 keV, were achieved. PMID:23765301

  10. Large-aperture refractive lenses for momentum-resolved spectroscopy with hard X-rays

    PubMed Central

    Fukui, Hiroshi; Simon, Markus; Nazmov, Vladimir; Mohr, Jürgen; Evans-Lutterodt, Kenneth; Stein, Aaron; Baron, Alfred Q. R.

    2013-01-01

    One-dimensional kinoform and prism refractive lenses with large aperture and high transmittance at 22?keV have been investigated. A 12.0?µm focus size (full width at half-maximum) and an effective aperture of 0.85?mm, at a focal length of 705?mm and 21.747?keV, were achieved. PMID:23765301

  11. Transfer of Large-Area Graphene Films for High-Performance Transparent

    E-print Network

    Transfer of Large-Area Graphene Films for High-Performance Transparent Conductive Electrodes transmittance and conductivity. In this paper, we report on an improved transfer process of large-area graphene strength, are flexible, and are chemically stable.5,6,9 Production of large-area and high-quality graphene

  12. Momentum transfer in the boundary layer when there is acceleration and combustion of ethanol as it evaporates behind a barrier

    SciTech Connect

    Boyarshinov, B.F.; Titkov, V.I.; Fedorov, S.Yu. [Institute of Thermophysics SB RAS, Novosibirsk (Russian Federation)

    2010-08-15

    Experimental data have been gathered on the local parameters of a boundary layer gas flow with ethanol combustion behind a 3 mm-high rib. These parameters include averaged velocities, temperatures, concentrations of stable substances and OH radicals and mass fluxes on the wall. The temperature and composition of the gases were studied with probe methods (thermocouple and chromatography). To measure the velocity and concentration of radicals, we applied the laser optical measurement methods of LDA and LIF. We propose a way of processing the obtained data utilizing balances in the continuity and motion equations. The influence of incident flow acceleration on the viscous and turbulent shear stresses at the wall and in the volume of the boundary layer has been analyzed to determine the acceleration parameters to be K = (0, 0.7, 1.3, and 4.1) x 10{sup -6}. It is shown that without a longitudinal pressure gradient (K = 0) on the combustion that is behind the rib, OH radicals accumulate with their highest concentrations existing in areas that do not coincide with the flame front and are shifted toward the oxidizer. The main mechanism of momentum transfer is connected to the boundary layer separation. In the presence of acceleration caused by a negative longitudinal pressure gradient, the detachment area does not show up (in experiments with K > 0.7 x 10{sup -6}); shear stresses increase substantially and reach one percent of the dynamic pressure. The general level of turbulent stresses in the reacting boundary layer becomes higher than in the case without acceleration. The incident airflow is also accelerated by the reacting boundary layer in which the maximum velocity is formed. (author)

  13. Large momentum scale two-particle correlation analysis of Au-Au collisions at ?s_NN = 130 GeV

    NASA Astrophysics Data System (ADS)

    Ishihara, Aya

    2001-10-01

    Preliminary results are presented of analyses of two-particle momentum space correlations which are functions of kinematic variables m_T, ? and ?. Results for joint auto-correlations are also shown which are functions of differences between the momentum space variables for two particles. We focus on the large-scale charge dependent and charge independent correlation structures observed in STAR data and their dependences on collision centrality.

  14. Prediction of effect of high free stream turbulence on momentum transport and heat transfer in a flat plate turbulent boundary layer

    Microsoft Academic Search

    Ganesh Ramamurthy Iyer

    1998-01-01

    A modified low Reynolds number k-varepsilon model for predicting effects of high free stream turbulence (FST) on momentum transport and heat transfer in a flat plate turbulent boundary layer is presented. The prediction capabilities of four well tested k-varepsilon models (Launder-Sharma, K-Y Chien, Lam-Bremhorst and Jones-Launder) under high FST conditions (initial turbulence intensity, Tusbi>5%) were investigated using a partial differential

  15. Observational results on the influence of stability and wind-wave coupling on momentum transfer and turbulent fluctuations over ocean waves

    Microsoft Academic Search

    K. L. Davidson

    1974-01-01

    Turbulence data obtained over ocean waves during the BOMEX experiment of 1969 are presented. Procedures in measurement and analyses are described which include adjustments for possible platform, R\\/V FLIP, motion. Momentum transfer is shown to have been influenced by both stability and wind-wave coupling. The wind-wave coupling influence is separated from the stability influence and is described in terms of

  16. Comparison of segmental linear and angular momentum transfers in two-handed backhand stroke stances for different skill level tennis players.

    PubMed

    Wang, Lin-Hwa; Lin, Hwai-Ting; Lo, Kuo-Cheng; Hsieh, Yung-Chun; Su, Fong-Chin

    2010-07-01

    The purpose of this study was to investigate the differences of momentum transfer from the trunk and upper extremities to the racket between open and square stances for different skill levels players in the two-handed backhand stroke. The motion capture system with twenty-one reflective markers attached on anatomic landmarks of the subject was used for two-handed backhand stroke motion data collection. Twelve subjects were divided into an advanced group and an intermediate group based on skill level. The three-dimensional linear and angular momentums of the trunk, upper arm, forearm, hand and racket were used for kinetic chain analysis. Results showed that all players with the square stance had significantly larger backward linear momentum contribution in trunk and upper arm than with the open stance (p<.05) irrespective of playing level. However, the external rotation angular momentum of the shoulder joint was significantly larger with an open stance than with a square stance (p=.047). Comparison of playing levels showed that the intermediate group performed higher linear momentum in three components of the trunk, upper arm backward linear momentum, and trunk right bending angular momentum than the advanced group significantly (p<.05). The advanced group reduces trunk linear movement to keep stability and applies trunk and linkage segment rotation to generate backhand stroke power. The advanced group also has a quick backswing for increasing acceleration and maintains longer in the follow-through phase for shock energy absorption. This information could improve training protocol design for teaching the two-handed backhand stroke and teaching players, especially beginners, how to make an effective stroke. PMID:19837630

  17. A new model of angular momentum transfer from the rotating central body of a two-body system to the orbital motion of the system

    NASA Astrophysics Data System (ADS)

    Schmutzer, E.

    2006-01-01

    In a previous paper we treated within the framework of our Projective Unified Field Theory (Schmutzer 2004, 2005a) the 2-body system (e.g. Earth-Moon system) with a rotating central body in a rather abstract manner. Here a concrete model of the transfer of angular momentum from the rotating central body to the orbital motion of the whole 2-body system is presented, where particularly the transfer is caused by the inhomogeneous gravitational force of the Moon acting on the oceanic waters of the Earth, being modeled by a spherical shell around the solid Earth. The theory is numerically tested.

  18. Search for dark matter candidates and large extra dimensions in events with a jet and missing transverse momentum with the ATLAS detector

    E-print Network

    Taylor, Frank E.

    A search for new phenomena in events with a high-energy jet and large missing transverse momentum is performed using data from proton-proton collisions at ?s = 7 TeV with the ATLAS experiment at the Large Hadron Collider. ...

  19. Risk-based analytical method transfer: application to large multi-product transfers.

    PubMed

    Raska, Christina S; Bennett, Tony S; Goodberlet, Scott A

    2010-07-15

    As pharmaceutical companies adapt their business models, a new approach to analytical method transfer is needed to efficiently handle transfers of multiple products, associated with situations such as site consolidations/closures. Using the principles of risk management, a risk-based method transfer approach is described, which defines appropriate transfer activities based on a risk assessment of the methods and experience of the receiving unit. A key step in the process is detailed knowledge transfer from the transferring unit to the receiving unit. The amount of transfer testing required can be streamlined or eliminated on the basis of a number of factors, including method capability, receiving unit familiarity, and method past performance. PMID:20557030

  20. Deposition of thin silicon layers on transferred large area graphene

    SciTech Connect

    Lupina, Grzegorz, E-mail: lupina@ihp-microelectronics.com; Kitzmann, Julia; Lukosius, Mindaugas; Dabrowski, Jarek; Wolff, Andre; Mehr, Wolfgang [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany)] [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany)

    2013-12-23

    Physical vapor deposition of Si onto transferred graphene is investigated. At elevated temperatures, Si nucleates preferably on wrinkles and multilayer graphene islands. In some cases, however, Si can be quasi-selectively grown only on the monolayer graphene regions while the multilayer islands remain uncovered. Experimental insights and ab initio calculations show that variations in the removal efficiency of carbon residuals after the transfer process can be responsible for this behavior. Low-temperature Si seed layer results in improved wetting and enables homogeneous growth. This is an important step towards realization of electronic devices in which graphene is embedded between two Si layers.

  1. Light harvesting and energy transfer in large multidomain molecules

    NASA Astrophysics Data System (ADS)

    Spanggaard, Holger; Krebs, Frederik C.; Jørgensen, Mikkel; Rozlosnik, Noemi; Larsen, Niels B.; Hagemann, Ole

    2005-10-01

    Light harvesting and energy transfer in two oligomer-dye assemblies has been investigated. In both cases the oligomer was a poly(terphenylenecyanovinylene) derivative while two different dyes was used, a porphyrin and an ionic dye. It is well known that the efficiency of solar cells consisting of a single homopolymer is limited. To increase overall efficiency different strategies have been used. One possible strategy aims at covalently linking different domains. With careful design, this type of assemblies is envisaged to show improved charge separation and charge transport properties. We have shown how photophysical measurements can be used to determine what happens to an exciton formed on any of the domains. From fluorescence and absorption measurements on the assemblies, along with model compounds, it was possible to quantify the number of excitons that are emitted (fluorescence), transferred between domains or lost in internal transfer processes. Both steady state and lifetime measurements were performed in solution and on solid films. The effect of acid was investigated in the cases of the oligomer-porphyrin assembly. We found that in solution the effect of acid was an increase in the time of energy transfer, probably due to acid induced structural change of the porphyrin moiety. It was possible to make LB-films of the ionic dye-assembly, which made it possible to investigate a monolayer of the assembly.

  2. Membranes from monopole operators in ABJM theory: Large angular momentum and M-theoretic AdS4/CFT3

    NASA Astrophysics Data System (ADS)

    Kovacs, Stefano; Sato, Yuki; Shimada, Hidehiko

    2014-09-01

    We study the duality between M-theory in AdS_4 × S^7/{Z}_k and the ABJM {N}=6 Chern-Simons-matter theory with gauge group U(N) × {U}(N) and level k, taking N large and k of order 1. In this M-theoretic regime the lack of an explicit formulation of M-theory in AdS_4 × S^7/{Z}_k makes the gravity side difficult, while the CFT is strongly coupled and the planar approximation is not applicable. We focus on states on the gravity side with large angular momentum J? 1 associated with a single plane of rotation in S^7 and identify their dual operators in the CFT. We show that natural approximation schemes arise on both sides thanks to the presence of the small parameter 1/J. On the AdS side, we use the matrix model of M-theory on the maximally supersymmetric pp-wave background with matrices of size J/k. A perturbative treatment of this matrix model provides a good approximation to M-theory in AdS_4 × S^7/{Z}_k when N^{1/3}? J? N^{1/2}. On the CFT side, we study the theory on S^2× {R} with magnetic flux J/k. A Born-Oppenheimer-type expansion arises naturally for large J in spite of the theory being strongly coupled. The energy spectra on the two sides agree at leading order. This provides a non-trivial test of the AdS_4/CFT_3 correspondence including near-BPS observables associated with membrane degrees of freedom, thus verifying the duality beyond the previously studied sectors corresponding to either BPS observables or the type IIA string regime.

  3. Containment condensing heat transfer

    NASA Astrophysics Data System (ADS)

    Gido, R. G.; Koestel, A.

    A mechanistic heat transfer model that is valid for large scale containment heat sinks was presented. The model development is based on the determination that the condensation is controlled by mass diffusion through the vapor-air boundary layer, and the application of the classic Reynolds' analog to formulate expressions for the transfer of heat and mass based on hydrodynamic measurements of the momentum transfer. As a result, the analysis depends on the quantification of the shear stress (momentum transfer) at the interface between the condensate film and the vapor-air boundary layer. In addition, the currently used Tagami and Uchida test observations and their range of applicability are explained.

  4. Large oncosomes mediate intercellular transfer of functional microRNA

    PubMed Central

    Morello, Matteo; Minciacchi, Valentina R; de Candia, Paola; Yang, Julie; Posadas, Edwin; Kim, Hyung; Griffiths, Duncan; Bhowmick, Neil; Chung, Leland WK; Gandellini, Paolo; Freeman, Michael R; Demichelis, Francesca; Di Vizio, Dolores

    2013-01-01

    Prostate cancer cells release atypically large extracellular vesicles (EVs), termed large oncosomes, which may play a role in the tumor microenvironment by transporting bioactive molecules across tissue spaces and through the blood stream. In this study, we applied a novel method for selective isolation of large oncosomes applicable to human platelet-poor plasma, where the presence of caveolin-1-positive large oncosomes identified patients with metastatic disease. This procedure was also used to validate results of a miRNA array performed on heterogeneous populations of EVs isolated from tumorigenic RWPE-2 prostate cells and from isogenic non-tumorigenic RWPE-1 cells. The results showed that distinct classes of miRNAs are expressed at higher levels in EVs derived from the tumorigenic cells in comparison to their non-tumorigenic counterpart. Large oncosomes enhanced migration of cancer-associated fibroblasts (CAFs), an effect that was increased by miR-1227, a miRNA abundant in large oncosomes produced by RWPE-2 cells. Our findings suggest that large oncosomes in the circulation report metastatic disease in patients with prostate cancer, and that this class of EV harbors functional molecules that may play a role in conditioning the tumor microenvironment. PMID:24091630

  5. Large oncosomes mediate intercellular transfer of functional microRNA.

    PubMed

    Morello, Matteo; Minciacchi, Valentina R; de Candia, Paola; Yang, Julie; Posadas, Edwin; Kim, Hyung; Griffiths, Duncan; Bhowmick, Neil; Chung, Leland W K; Gandellini, Paolo; Freeman, Michael R; Demichelis, Francesca; Di Vizio, Dolores

    2013-11-15

    Prostate cancer cells release atypically large extracellular vesicles (EVs), termed large oncosomes, which may play a role in the tumor microenvironment by transporting bioactive molecules across tissue spaces and through the blood stream. In this study, we applied a novel method for selective isolation of large oncosomes applicable to human platelet-poor plasma, where the presence of caveolin-1-positive large oncosomes identified patients with metastatic disease. This procedure was also used to validate results of a miRNA array performed on heterogeneous populations of EVs isolated from tumorigenic RWPE-2 prostate cells and from isogenic non-tumorigenic RWPE-1 cells. The results showed that distinct classes of miRNAs are expressed at higher levels in EVs derived from the tumorigenic cells in comparison to their non-tumorigenic counterpart. Large oncosomes enhanced migration of cancer-associated fibroblasts (CAFs), an effect that was increased by miR-1227, a miRNA abundant in large oncosomes produced by RWPE-2 cells. Our findings suggest that large oncosomes in the circulation report metastatic disease in patients with prostate cancer, and that this class of EV harbors functional molecules that may play a role in conditioning the tumor microenvironment. PMID:24091630

  6. Search for New Phenomena in tt? Events with Large Missing Transverse Momentum in Proton-Proton Collisions at ?s=7??TeV with the ATLAS Detector

    E-print Network

    Taylor, Frank E.

    A search for new phenomena in tt? events with large missing transverse momentum in proton-proton collisions at a center-of-mass energy of 7 TeV is presented. The measurement is based on 1.04??fb[superscript -1] of data ...

  7. Transfer of momentum from different arm segments to a light movable target during a straight punch thrown by expert boxers.

    PubMed

    Nakano, Genki; Iino, Yoichi; Imura, Akiko; Kojima, Takeji

    2014-01-01

    The aim of this study was to determine the relationship between the reductions in momentum of punching arm segments and the impulse of the impact force when boxers throw a punch at a movable target with a mass almost equal to that of the human head. Nine male expert collegiate boxers threw a rear-hand straight punch at the target with their full effort. The reductions in momentum of the upper arm, forearm and fist plus glove of the punching arm during impact and the impulse were determined using a motion capture system and an accelerometer attached to the target. The reduction in momentum of the punching arm explained approximately 95% of the impulse: 40%, 35% and 20% for the upper arm, forearm and fist plus glove, respectively. The Pearson correlation coefficient between the peak and impulse of the impact force was 0.902. These results suggest that for boxers increasing the momentum of the punching arm rather than that of the other body segments immediately before the impact is effective at increasing the impulse of the punch into the face of an opponent. PMID:24404907

  8. Measurements of the proton elastic-form-factor ratio mu pG p E/G p M at low momentum transfer.

    PubMed

    Ron, G; Glister, J; Lee, B; Allada, K; Armstrong, W; Arrington, J; Beck, A; Benmokhtar, F; Berman, B L; Boeglin, W; Brash, E; Camsonne, A; Calarco, J; Chen, J P; Choi, Seonho; Chudakov, E; Coman, L; Craver, B; Cusanno, F; Dumas, J; Dutta, C; Feuerbach, R; Freyberger, A; Frullani, S; Garibaldi, F; Gilman, R; Hansen, O; Higinbotham, D W; Holmstrom, T; Hyde, C E; Ibrahim, H; Ilieva, Y; de Jager, C W; Jiang, X; Jones, M K; Kang, H; Kelleher, A; Khrosinkova, E; Kuchina, E; Kumbartzki, G; LeRose, J J; Lindgren, R; Markowitz, P; May-Tal Beck, S; McCullough, E; Meekins, D; Meziane, M; Meziani, Z-E; Michaels, R; Moffit, B; Norum, B E; Oh, Y; Olson, M; Paolone, M; Paschke, K; Perdrisat, C F; Piasetzky, E; Potokar, M; Pomatsalyuk, R; Pomerantz, I; Puckett, A; Punjabi, V; Qian, X; Qiang, Y; Ransome, R; Reyhan, M; Roche, J; Rousseau, Y; Saha, A; Sarty, A J; Sawatzky, B; Schulte, E; Shabestari, M; Shahinyan, A; Shneor, R; Sirca, S; Slifer, K; Solvignon, P; Song, J; Sparks, R; Subedi, R; Strauch, S; Urciuoli, G M; Wang, K; Wojtsekhowski, B; Yan, X; Yao, H; Zhan, X; Zhu, X

    2007-11-16

    High-precision measurements of the proton elastic form-factor ratio, mu pG p E/G p M, have been made at four-momentum transfer, Q2, values between 0.2 and 0.5 GeV2. The new data, while consistent with previous results, clearly show a ratio less than unity and significant differences from the central values of several recent phenomenological fits. By combining the new form-factor ratio data with an existing cross-section measurement, one finds that in this Q2 range the deviation from unity is primarily due to G p E being smaller than expected. PMID:18233135

  9. Efficient transfer of two large secondary metabolite pathway gene clusters into heterologous hosts by transposition

    Microsoft Academic Search

    Jun Fu; Silke C. Wenzel; Olena Perlova; Junping Wang; Frank Gross; Zhiru Tang; Yulong Yin; A. Francis Stewart; Rolf Muller; Youming Zhang

    2008-01-01

    Horizontal gene transfer by transposition has been widely used for transgenesis in prokaryotes. However, conjugation has been preferred for trans- fer of large transgenes, despite greater restrictions of host range. We examine the possibility that trans- posons can be used to deliver large transgenes to heterologous hosts. This possibility is particularly relevant to the expression of large secondary metab- olite

  10. A blister test for interfacial adhesion of large-scale transferred graphene

    E-print Network

    Huang, Rui

    methods have been proposed to produce large area, monolayer graphene. Among them, one of the most 0008.elsevier.com/locate/carbon #12;promising is chemical vapor deposition (CVD). Li et al. [4] grew large area monolayer grapheneA blister test for interfacial adhesion of large-scale transferred graphene Z. Cao a , P. Wang

  11. Transfer-Free Batch Fabrication of Large-Area Suspended Graphene Membranes

    E-print Network

    Zettl, Alex

    Transfer-Free Batch Fabrication of Large- Area Suspended Graphene Membranes Benjami´n Alema films in large-area membrane applications and permits further characterization of this important new ABSTRACT We demonstrate a process for batch production of large-area (100 3000 m2 ) patterned free

  12. Transfer patterning of large-area graphene nanomesh via holographic lithography and plasma etching

    E-print Network

    Fisher, Frank

    Transfer patterning of large-area graphene nanomesh via holographic lithography and plasma etching present a high-throughput fabrication technique to create a large-area graphene nanomesh (GNM the copper foil. Large-area (5 Ã? 5 cm), periodic (500 and 935 nm in pitch), uniform, and flexible GNMs were

  13. Relative intensity noise transfer of large-bandwidth pump lasers in Raman fiber

    E-print Network

    Boyer, Edmond

    Relative intensity noise transfer of large-bandwidth pump lasers in Raman fiber amplifiers Kafing, such incoherent pumping sources must be considered for the purpose of low-noise Raman amplifiers. © 2006 Optical transfer for a fiber Raman amplifier when the pump beam has a bandwidth that may be much larger than

  14. MESSENGER Observations of Large Flux Transfer Events at Mercury

    NASA Technical Reports Server (NTRS)

    Slavin, James A.; Lepping, Ronald P.; Wu, Chin-Chun; Anderson, Brian J.; Baker, Daniel N.; Benna, Mehdi; Boardsen, Scott A.; Killen, Rosemary M.; Korth, Haje; Krimigis, Stamatios M.; McClintock, William E.; McNutt, Ralph L., Jr.; Sarantos, Menelaos; Schriver, David; Solomon, Sean C.; Travnicek, Pavel; Zurbuchen, Thomas H.

    2010-01-01

    Six flux transfer events (FTEs) were encountered during MESSENGER's first two flybys of Mercury (MI and M2). For MI the interplanetary magnetic field (IMF) was predominantly northward and four FTEs with durations of 1 to 6 s were observed in the magnetosheath following southward 1M F turnings. The IMF was steadily southward during M2, and an FTE 4 s in duration was observed just inside the dawn magnetopause followed approx.32 s later by a 7-s FTE in the magnetosheath. Flux rope models were fit to the magnetic field data to detem11ne PTE dimensions and flux content The largest FTE observed by MESSENGER had a diameter of approx. 1 R(sub M) (where R(sub M) is Mercury's radius), and its open magnetic field increased the fraction of the surface exposed to the solar wind by 10 - 20 percent and contributed up to approx.30 kV to the cross-magnetospheric electric potential.

  15. Controls on gas transfer velocities in a large river

    EPA Science Inventory

    The emission of biogenic gases from large rivers can be an important component of regional greenhouse gas budgets. However, emission rate estimates are often poorly constrained due to uncertainties in the air-water gas exchange rate. We used the floating chamber method to estim...

  16. Transfer of spin angular momentum from Cs vapor to nearby Cs salts through laser-induced spin currents

    SciTech Connect

    Ishikawa, K.; Patton, B.; Olsen, B. A.; Jau, Y.-Y.; Happer, W. [Graduate School of Material Science, University of Hyogo, Ako-gun, Hyogo 678-1297 (Japan); Joseph Henry Laboratory, Department of Physics, Princeton University, Princeton, New Jersey 08544 (United States)

    2011-06-15

    Optical pumping of alkali-metal atoms in vapor cells causes spin currents to flow to the cell walls where excess angular momentum accumulates in the wall nuclei. Experiments reported here indicate that the substantial enhancement of the nuclear-spin polarization of salts at the cell walls is primarily due to the nuclear-spin current, with a lesser contribution from the electron-spin current of the vapor.

  17. Large aperture deformable mirror with a transferred single-crystal silicon membrane actuated using large-stroke PZT Unimorph Actuators

    NASA Technical Reports Server (NTRS)

    Hishinumat, Yoshikazu; Yang, Eui - Hyeok (EH)

    2005-01-01

    We have demonstrated a large aperture (50 mm x 50 mm) continuous membrane deformable mirror (DM) with a large-stroke piezoelectric unimorph actuator array. The DM consists of a continuous, large aperture, silicon membrane 'transferred' in its entirety onto a 20 x 20 piezoelectric unimorph actuator array. A PZT unimorph actuator, 2.5 mm in diameter with optimized PZT/Si thickness and design showed a deflection of 5.7 [m at 20V. An assembled DM showed an operating frequency bandwidth of 30 kHz and influence function of approximately 30%.

  18. Pen-based Knowledge Transfer Techniques to Support Lifelong Learning In Large Scale Organizations

    Microsoft Academic Search

    Steven Shaw; Goran Kattenberg

    2007-01-01

    This paper will focus on multimodal knowledge transfer techniques to facilitate lifelong learning for workers in large scale corporate and government organizations. Learners in large scale organizations are provided with access to high quality digital e-learning materials to address specific learning requirements such as procedure, policies, procedures and applications. The audience is usually very heterogenous and consists of different age

  19. Layer-by-Layer Transfer of Multiple, Large Area Sheets of Graphene Grown in

    E-print Network

    Rogers, John A.

    Layer-by-Layer Transfer of Multiple, Large Area Sheets of Graphene Grown in Multilayer Stacks- tion from bulk pieces of graphite.1 4 Prom- ising approaches to large area graphene in- clude epitaxial on the SiC.18 To- tal areas are limited, however, by the moder- ate adhesion of Au to graphene. In another

  20. Associated production of an isolated, large-transverse-momentum lepton (electron or muon), and two jets at the CERN pp collider

    Microsoft Academic Search

    Geoffrey T J Arnison; O. C. Allkofer; Alan Astbury; Bernard Aubert; C. Bacci; G. Bauer; A. Bézaguet; R. K. Bock; T. J. V. Bowcock; M. Calvetti; P. Catz; P. Cennini; S. Centro; F. Ceradini; S. Cittolin; D. Cline; C. Cochet; J. Colas; M. Corden; D. Dallman; D. Dau; M. Debeer; M. Della Negra; M. Demoulin; D. Denegri; D. Dibitonto; A. di Ciaccio; L. Dobrzynski; J. D. Dowell; K. Eggert; E. Eisenhandler; N. Ellis; P. Erhard; H. Faissner; M. Fincke; P. Flynn; G. Fontaine; R. Frey; R. Frühwirth; J. Garvey; S. Geer; C. Ghesquière; P. Ghez; W. R. Gibson; Y. Giraud-Héraud; A. Givernaud; A. Gonidec; G. Grayer; W. Guryn; Traudl Hansl-Kozanecka; W. J. Haynes; L. O. Hertzberger; D. Hoffmann; H. Hoffmann; D. J. Holthuizen; R James Homer; A K Honma; Werner Jank; Ginette Jorat; Peter I P Kalmus; V. Karimäki; Richard K Keeler; Ian Richard Kenyon; A. Kernan; Ritva Kinnunen; Witold Kozanecki; Didier Kryn; P. Kyberd; F. Lacava; J.-P. Laugier; J.-P. Lees; H. Lehmann; R. Leuchs; A. Lévêque; D. Linglin; E. Locci; M. Loret; T W Markiewicz; Guy Maurin; T. McMahon; J.-P. Mendiburu; M.-N. Minard; M. Mohammadi; M. Moricca; K. Morgan; F. Muller; A. K. Nandi; Lutz Naumann; Alan Robert Norton; A. Orkin-Lecourtois; L. Paoluzi; F. Paus; G. Piano Mortari; E. Pietarinen; M. Pimiä; D. Pitman; Alfredo Placci; J.-P. Porte; E. Radermacher; J. Ransdell; H. Reithler; Jean Pierre Charles Revol; J. Rich; M. Rijssenbeek; C. Roberts; J. Rohlf; P. Rossi; C. Rubbia; B. Sadoulet; G Salvini; J. Sass; A. Savoy-Navarro; D. Schinzel; W. Scott; T. P. Shah; I. Sheer; D. Smith; J. Strauss; J. Streets; K. Sumorok; F. Szoncso; C. Tao; G. Thompson; J. Timmer; E. Tscheslog; J. Tuominiemi; B. van Eijk; J.-P. Vialle; J. Vrana; V. Vuillemin; H. D. Wahl; P. Watkins; J. Wilson; I. Wingerter; C.-E. Wulz; M. Yvert

    1984-01-01

    A clear signal is observed for the production of an isolated large-transverse-momentum lepton in association with two or three centrally produced jets. The two-jet events cluster around the W+\\/- mass, indicating a novel decay of the Intermediate Vector Boson. The rate and features of these events are not consistent with expectations of known quark decays (charm, bottom). They are, however,

  1. Production of hadrons at large transverse momentum in 200-, 300-, and 400GeV p-p and p-nucleus collisions

    Microsoft Academic Search

    D. Antreasyan; J. W. Cronin; H. J. Frisch; M. J. Shochet; L. Kluberg; P. A. Piroue; R. L. Sumner

    1979-01-01

    Measurements of the invariant cross section Ed³sigma\\/d³p are presented for the production of hadrons (..pi.., K, p, and p-bar) at large transverse momentum (p\\/sub perpendicular\\/) by 200-, 300-, and 400-GeV protons incident on Hâ, Dâ, Be, Ti, and W targets. The measurements were made at a laboratory angle of 77 mrad, which corresponds to angles near 90° in the c.m.

  2. Knowledge transfer in a digital world: Field data acquisition, uncertainty, visualization, and data management

    Microsoft Academic Search

    C. E. Bond; Z. K. Shipton; R. R. Jones; R. W. H. Butler; A. D. Gibbs

    2007-01-01

    Knowledge transfer has gained political and social momentum in the twenty-first century. The emphasis of this momentum has been on encouraging the transfer of scientific expertise between academia and industry, and on informing the public. The widespread use of the World Wide Web has provided a mechanism for sharing large vol- umes of information, which enables knowl- edge transfer between

  3. Riccati discrete time transfer matrix method for elastic beam undergoing large overall motion

    Microsoft Academic Search

    Bin He; Xiaoting Rui; Guoping Wang

    2007-01-01

    An efficient method for dynamics simulation for elastic beam with large overall spatial motion and nonlinear deformation,\\u000a namely, the Riccati discrete time transfer matrix method (Riccati-DT-TMM), is proposed in this investigation. With finite\\u000a segments, continuous deformation field of a beam can be decomposed into many rigid bodies connected by rotational springs.\\u000a Discrete time transfer matrices of rigid bodies and rotational

  4. New Empirical Equation for the Atomic Form Factor Function in the Momentum Transfer Range, q?=?0–50 Å?1 for the Elements in the Range 1? Z ?30

    PubMed Central

    Muhammad, Wazir; Lee, Sang Hoon

    2013-01-01

    The importance of Atomic Form Factors (f) is well-known to the scientific community. Tabulated values for f are mostly used in calculating cross-sections and Monte Carlo sampling for the coherent scattering of photons. The uses of these values are subjected to different approximations and interpolation techniques because the available data points for f in the literature for specified momentum-transfer-grids are very limited. In order to make it easier to accurately use the tabulated data, a mathematical expression for f functions would be a great achievement. Therefore, the current study was designed to suggest an empirical expression for the f functions. In the results, an empirical equation for Hubbell's tabulated data for f is created in the momentum transfer range, q?=?0–50 Å?1 for the elements in the range 1? Z ?30. The number of applied parameters was seven. The fitting to f showed that the maximum deviation was within 3%, 4% and 5% for the element having, Z?=?1–11, Z?=?12–22 and Z?=?23–30, respectively, while the average deviations were within 0.3–2.25% for all elements (i.e., Z?=?1–30). The values generated by the analytical equation were used in the Monte Carlo code instead of Hubbell’s tabulated values. The statistical noise in the Probability Distribution Functions of coherently scattered photons was efficiently removed. Furthermore, it also reduced the dependence on different interpolation techniques and approximations, and on the use of large tabulated data for f with the specified elements. PMID:23936339

  5. Preferential enrichment of large-sized very low density lipoprotein populations with transferred cholesteryl esters

    SciTech Connect

    Eisenberg, S.

    1985-04-01

    The effect of lipid transfer proteins on the exchange and transfer of cholesteryl esters from rat plasma HDL2 to human very low (VLDL) and low density (LDL) lipoprotein populations was studied. The use of a combination of radiochemical and chemical methods allowed separate assessment of (/sup 3/H)cholesteryl ester exchange and of cholesteryl ester transfer. VLDL-I was the preferred acceptor for transferred cholesteryl esters, followed by VLDL-II and VLDL-III. LDL did not acquire cholesteryl esters. The contribution of exchange of (/sup 3/H)cholesteryl esters to total transfer was highest for LDL and decreased in reverse order along the VLDL density range. Inactivation of lecithin: cholesterol acyltransferase (LCAT) and heating the HDL2 for 60 min at 56 degrees C accelerated transfer and exchange of (/sup 3/H)cholesteryl esters. Addition of lipid transfer proteins increased cholesterol esterification in all systems. The data demonstrate that large-sized, triglyceride-rich VLDL particles are preferred acceptors for transferred cholesteryl esters. It is suggested that enrichment of very low density lipoproteins with cholesteryl esters reflects the triglyceride content of the particles.

  6. A Piezoelectric Unimorph Deformable Mirror Concept by Wafer Transfer for Ultra Large Space Telescopes

    NASA Technical Reports Server (NTRS)

    Yang, Eui-Hyeok; Shcheglov, Kirill

    2002-01-01

    Future concepts of ultra large space telescopes include segmented silicon mirrors and inflatable polymer mirrors. Primary mirrors for these systems cannot meet optical surface figure requirements and are likely to generate over several microns of wavefront errors. In order to correct for these large wavefront errors, high stroke optical quality deformable mirrors are required. JPL has recently developed a new technology for transferring an entire wafer-level mirror membrane from one substrate to another. A thin membrane, 100 mm in diameter, has been successfully transferred without using adhesives or polymers. The measured peak-to-valley surface error of a transferred and patterned membrane (1 mm x 1 mm x 0.016 mm) is only 9 nm. The mirror element actuation principle is based on a piezoelectric unimorph. A voltage applied to the piezoelectric layer induces stress in the longitudinal direction causing the film to deform and pull on the mirror connected to it. The advantage of this approach is that the small longitudinal strains obtainable from a piezoelectric material at modest voltages are thus translated into large vertical displacements. Modeling is performed for a unimorph membrane consisting of clamped rectangular membrane with a PZT layer with variable dimensions. The membrane transfer technology is combined with the piezoelectric bimorph actuator concept to constitute a compact deformable mirror device with a large stroke actuation of a continuous mirror membrane, resulting in a compact A0 systems for use in ultra large space telescopes.

  7. On the effects of mass and momentum transfer from droplets impacting on steady two-dimensional rimming flow in a horizontal cylinder

    NASA Astrophysics Data System (ADS)

    Williams, J.; Hibberd, S.; Power, H.; Riley, D. S.

    2012-05-01

    Motivated by applications in aero-engines, steady two-dimensional thin-film flow on the inside of a circular cylinder is studied when the film surface is subject to mass and momentum transfer from impacting droplets. Asymptotic analysis is used systematically to identify distinguished limits that incorporate these transfer effects at leading order and to provide a new mathematical model. Applying both analytical and numerical approaches to the model, a set of stable steady, two-dimensional solutions that fit within the rational framework is determined. A number of these solutions feature steep fronts and associated recirculating pools, which are undesirable in an aeroengine since oil may be stripped away from the steep fronts when there is a core flow external to the film, and recirculation may lead to oil degradation. The model, however, provides a means of investigating whether the formation of the steep fronts on the film surface and of internal recirculation pools can be delayed, or inhibited altogether, by designing jets to deliver prescribed distributions of oil droplets or by the judicious siting of oil sinks. Moreover, by studying pathlines, oil-residence times can be predicted and systems optimized.

  8. Current recycling and SFQ signal transfer in large scale RSFQ circuits

    Microsoft Academic Search

    J. H. Kang; S. B. Kaplan

    2003-01-01

    The practical implementation of RSFQ technology in most digital electronics application areas requires much more complexity than the presently developed circuits. There are two important issues in building large-scale RSFQ circuits: 1) the recycling of the bias currents and 2) the transfer of SFQ pulses between circuits located far apart. RSFQ circuits are well known to operate with DC current

  9. Theoretical Investigation of Large Kinetic Isotope Effects for Proton-Coupled Electron Transfer in Ruthenium Polypyridyl

    E-print Network

    Hammes-Schiffer, Sharon

    in Ruthenium Polypyridyl Complexes Nedialka Iordanova and Sharon Hammes-Schiffer* Contribution from transfer in ruthenium polypyridyl complexes is presented. The three reactions studied are as follows: (1 temperature for PCET reactions in ruthenium polypyridyl complexes.7-9 These large kinetic isotope effects

  10. Heat transfer characteristics of flat plate finned-tube heat exchangers with large fin pitch

    Microsoft Academic Search

    Yonghan Kim; Yongchan Kim

    2005-01-01

    The objective of this study is to provide experimental data that can be used in the optimal design of flat plate finned-tube heat exchangers with large fin pitch. In this study, 22 heat exchangers were tested with a variation of fin pitch, number of tube row, and tube alignment. The air-side heat transfer coefficient decreased with a reduction of the

  11. Angular-momentum transfer and alignment in deep-inelastic reactions for nearly symmetric heavy-ion systems

    NASA Astrophysics Data System (ADS)

    Pacheco, A. J.; Wozniak, G. J.; McDonald, R. J.; Diamond, R. M.; Hsu, C. C.; Moretto, L. G.; Morrissey, D. J.; Sobotka, L. G.; Stephens, F. S.

    1983-04-01

    The magnitude and alignment of the spin transferred to the fragments in the deep-inelastic reactions of 8.5 MeV/nucleon 165Ho on 176Yb, 148Sm, and natAg were investigated using continuum ?-ray multiplicity and anisotropy techniques. The detection system consisted of a highly redundant arrangement of particle and ?-ray detectors and a ?-ray multiplicity filter. By using suitable reduced quantities, we show that for the most negative Q-values the multiplicity data are consistent with rigid-rotation of the intermediate dinuclear complex. The anisotropy data are compared to an equilibrium statistical model calculation. The sensitivity of the calculation to different assumptions concerning the composition of the ?-ray spectra is investigated. The magnitude and alignment of the spin imparted to the individual fragments as a function of Q-value are extracted for the three reactions.

  12. Multiple Phenotypic Changes Associated with Large-Scale Horizontal Gene Transfer

    PubMed Central

    Dougherty, Kevin; Smith, Brian A.; Moore, Autumn F.; Maitland, Shannon; Fanger, Chris; Murillo, Rachel; Baltrus, David A.

    2014-01-01

    Horizontal gene transfer often leads to phenotypic changes within recipient organisms independent of any immediate evolutionary benefits. While secondary phenotypic effects of horizontal transfer (i.e., changes in growth rates) have been demonstrated and studied across a variety of systems using relatively small plasmids and phage, little is known about the magnitude or number of such costs after the transfer of larger regions. Here we describe numerous phenotypic changes that occur after a large-scale horizontal transfer event (?1 Mb megaplasmid) within Pseudomonas stutzeri including sensitization to various stresses as well as changes in bacterial behavior. These results highlight the power of horizontal transfer to shift pleiotropic relationships and cellular networks within bacterial genomes. They also provide an important context for how secondary effects of transfer can bias evolutionary trajectories and interactions between species. Lastly, these results and system provide a foundation to investigate evolutionary consequences in real time as newly acquired regions are ameliorated and integrated into new genomic contexts. PMID:25048697

  13. Transfer and occurrence of large mercury resistance plasmids in river epilithon. [Pseudomonas fluorescens; Pseudomonas putida

    SciTech Connect

    Bale, M.J.; Fry, J.C.; Day, M.J.

    1988-04-01

    In situ mating experiments were done in the River Taff, South Wales, United Kingdom, by using a natural mercury resistance plasmid (pQM1) isolated from a mixture of epilithic bacteria in vitro. The river temperature from March to November was found to influence transfer frequencies strongly (6.8 x 10/sup -9/ to 1.5 x 10/sup -2/ per recipient). A linear relationship existed between log/sub 10/ transfer frequency and river temperature (6 to 21/sup 0/C), a 2.6/sup 0/C change in temperature giving a 10-fold change in transfer frequency. In vitro experiments showed that pQM1 transferred most efficiently between fluorescent pseudomonads and that one epilithic isolate (Pseudomonas fluorescens) was an efficient donor in situ. Experiments with a P. putida recipient showed that intact epilithic bacterial communities could transfer mercury resistance plasmids in situ at frequencies of up to 3.75 x 10/sup -6/ per recipient. Nineteen of the large (>250-kilobase) plasmids isolated by transfer into P. putida were studied in detail and grouped into seven types by restriction digests. Mercury resistance and UV resistance were found to be common linked phenotypes in 19 of the 23 plasmids tested.

  14. Efficient transfer of two large secondary metabolite pathway gene clusters into heterologous hosts by transposition

    PubMed Central

    Fu, Jun; Wenzel, Silke C.; Perlova, Olena; Wang, Junping; Gross, Frank; Tang, Zhiru; Yin, Yulong; Stewart, A. Francis; Zhang, Youming

    2008-01-01

    Horizontal gene transfer by transposition has been widely used for transgenesis in prokaryotes. However, conjugation has been preferred for transfer of large transgenes, despite greater restrictions of host range. We examine the possibility that transposons can be used to deliver large transgenes to heterologous hosts. This possibility is particularly relevant to the expression of large secondary metabolite gene clusters in various heterologous hosts. Recently, we showed that the engineering of large gene clusters like type I polyketide/nonribosomal peptide pathways for heterologous expression is no longer a bottleneck. Here, we apply recombineering to engineer either the epothilone (epo) or myxochromide S (mchS) gene cluster for transpositional delivery and expression in heterologous hosts. The 58-kb epo gene cluster was fully reconstituted from two clones by stitching. Then, the epo promoter was exchanged for a promoter active in the heterologous host, followed by engineering into the MycoMar transposon. A similar process was applied to the mchS gene cluster. The engineered gene clusters were transferred and expressed in the heterologous hosts Myxococcus xanthus and Pseudomonas putida. We achieved the largest transposition yet reported for any system and suggest that delivery by transposon will become the method of choice for delivery of large transgenes, particularly not only for metabolic engineering but also for general transgenesis in prokaryotes and eukaryotes. PMID:18701643

  15. Jet momentum balance independent of shear viscosity

    E-print Network

    R. B. Neufeld

    2012-02-24

    Jet momentum balance measurements, such as those recently performed by the CMS collaboration, provide an opportunity to quantify the energy transferred from a parton shower to the underlying medium in heavy-ion collisions. Specifically, I argue that the Cooper-Frye freezeout distribution associated with the energy and momentum deposited by the parton shower is controlled to a significant extent by the distribution of the underlying bulk matter and independent of the details of how deposited energy is redistributed in the medium, which is largely determined by transport coefficients such as shear viscosity. Thus by matching the distribution of momentum associated with the secondary jet in such measurements to the thermal distribution of the underlying medium, one can obtain a model independent estimate on the amount of parton shower energy deposited.

  16. Search for supersymmetry in events with large missing transverse momentum, jets, and at least one tau lepton in 20 fb[superscript ?1] of ?s = 8 TeV proton-proton collision data with the ATLAS detector

    E-print Network

    Taylor, Frank E.

    A search for supersymmetry (SUSY) in events with large missing transverse momentum, jets, at least one hadronically decaying tau lepton and zero or one additional light leptons (electron/muon), has been performed using ...

  17. Search for Dark Matter Candidates and Large Extra Dimensions in Events with a Photon and Missing Transverse Momentum in pp Collision Data at ?s=7??TeV with the ATLAS Detector

    E-print Network

    Taylor, Frank E.

    Results of a search for new phenomena in events with an energetic photon and large missing transverse momentum in proton-proton collisions at ?s=7??TeV are reported. Data collected by the ATLAS experiment at the LHC ...

  18. New model of angular momentum transfer from the rotating central body of a two-body system into the orbital motion of this system (with application to the earth-moon system)

    E-print Network

    E. Schmutzer

    2005-05-11

    In a previous paper we treated within the framework of our Projective Unified Field Theory (Schmutzer 2004, Schmutzer 2005a) the 2-body system (e.g. earth-moon system) with a rotating central body in a rather abstract manner. Here a concrete model of the transfer of angular momentum from the rotating central body to the orbital motion of the whole 2-body system is presented, where particularly the transfer is caused by the inhomogeneous gravitational force of the moon acting on the oceanic waters of the earth, being modeled by a spherical shell around the solid earth. The theory is numerically tested. Key words: transfer of angular momentum from earth to moon, action of the gravitational force of the moon on the waters of the earth.

  19. Crack-release transfer method of wafer-scale grown graphene onto large-area substrates.

    PubMed

    Lee, Jooho; Kim, Yongsung; Shin, Hyeon-Jin; Lee, ChangSeung; Lee, Dongwook; Lee, Sunghee; Moon, Chang-Yul; Lee, Su Chan; Kim, Sun Jun; Ji, Jae Hoon; Yoon, Hyong Seo; Jun, Seong Chan

    2014-08-13

    We developed a crack-release graphene transfer technique for opening up possibilities for the fabrication of graphene-based devices. Graphene film grown on metal catalysts/SiO2/Si wafer should be scathelessly peeled for sequent transferring to a target substrate. However, when the graphene is grown on the metal catalyst on a silicon substrate, there is a large tensile stress resulting from the difference of the coefficient of thermal expansion in the catalyst and silicon. The conventional methods of detaching graphene from metal catalysts were found to induce considerable mechanical damage on graphene films during separation processes including metal wet etching. Here we report a new technique wherein bubbles generated by electrolysis reaction separate thin metal catalysts from the SiO2/Si wafer. The dry attachment of graphene to the target wafer was processed utilizing a wafer to wafer bonding technique in a vacuum. We measured the microscopic image, Raman spectra, and electrical properties of the transferred graphene. The optical and electrical properties of the graphene transferred by the bubbles/dry method are better than those of the graphene obtained by mechanical/wet transfer. PMID:24967530

  20. Target excitation and angular momentum transfer in reactions of E / A =11. 9 MeV sup 28 Si with sup 181 Ta from 4. pi. charged particle, neutron, and. gamma. -ray multiplicity measurements

    SciTech Connect

    Majka, Z.; Abenante, V.; Li, Z.; Nicolis, N.G.; Sarantites, D.G.; Semkow, T.M.; Sobotka, L.G.; Stracener, D.W. (Department of Chemistry, Washington University, St. Louis, Missouri 63130 (USA)); Beene, J.R.; Hensley, D.C. (Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (USA)); Griffin, H.C. (University of Michigan, Ann Arbor, Michigan 48109 (USA))

    1989-11-01

    The conversion of kinetic energy into target-like fragment excitation and orbital angular momentum into fragment spin has been studied in the reaction 333 MeV {sup 28}Si with {sup 181}Ta. The light charged particles were detected in a small, highly segmented, 4{pi} phoswich detector system placed in the spin spectrometer, a 4{pi} NaI array which served as a neutron and gamma detector. Multiplicities of light charged particles and neutrons detected in coincidence with projectile-like fragments indicate that the excitation energy of the target-like fragment increases as the kinetic energy of the projectile-like fragment decreases through the quasielastic region and tends toward saturation as the kinetic energy of the projectile-like fragment approaches the kinetic energy corresponding to complete damping. Measurement of the {gamma}-ray multiplicity in coincidence with the projectile-like fragments indicates that the angular momentum transferred to the target-like fragment increases with decreasing mass of the projectile-like fragment for the quasielastic energy region in contrast to the energy region corresponding to completely damped processes where the angular momentum of the target-like fragment decreases with increasing mass loss from the projectile. The influence of preequilibrium processes on both excitation energy and angular momentum transfer to the target-like fragment is discussed. These data present further evidence that {ital l} waves below the entrance-channel critical angular momentum for fusion must contribute to the nonfusing reaction channels.

  1. Anomalous momentum and energy transfer rates for electrostatic ion-cyclotron turbulence in downward auroral-current regions of the Earth's magnetosphere. III

    NASA Astrophysics Data System (ADS)

    Jasperse, John R.; Basu, Bamandas; Lund, Eric J.; Grossbard, Neil

    2010-06-01

    Recently, a new multimoment fluid theory was developed for inhomogeneous, nonuniformly magnetized plasma in the guiding-center and gyrotropic approximation that includes the effect of electrostatic, turbulent, wave-particle interactions (see Jasperse et al. [Phys. Plasmas 13, 072903 (2006); Jasperse et al., Phys. Plasmas13, 112902 (2006)]). In the present paper, which is intended as a sequel, it is concluded from FAST satellite data that the electrostatic ion-cyclotron turbulence that appears is due to the operation of an electron, bump-on-tail-driven ion-cyclotron instability for downward currents in the long-range potential region of the Earth's magnetosphere. Approximate closed-form expressions for the anomalous momentum and energy transfer rates for the ion-cyclotron turbulence are obtained. The turbulent, inhomogeneous, nonuniformly magnetized, multimoment fluid theory given above, in the limit of a turbulent, homogeneous, uniformly magnetized, quasisteady plasma, yields the well-known formula for the anomalous resistivity given by Gary and Paul [Phys. Rev. Lett. 26, 1097 (1971)] and Tange and Ichimaru [J. Phys. Soc. Jpn. 36, 1437 (1974)].

  2. Anomalous momentum and energy transfer rates for electrostatic ion-cyclotron turbulence in downward auroral-current regions of the Earth's magnetosphere. III

    SciTech Connect

    Jasperse, John R.; Basu, Bamandas [Air Force Research Laboratory, Space Vehicles Directorate, Hanscom AFB, Massachusetts 01731 (United States); Lund, Eric J. [Space Science Center, University of New Hampshire, Durham, New Hampshire 03824 (United States); Grossbard, Neil [Institute for Scientific Research, Boston College, Chestnut Hill, Massachusetts 02467 (United States)

    2010-06-15

    Recently, a new multimoment fluid theory was developed for inhomogeneous, nonuniformly magnetized plasma in the guiding-center and gyrotropic approximation that includes the effect of electrostatic, turbulent, wave-particle interactions (see Jasperse et al. [Phys. Plasmas 13, 072903 (2006); ibid.13, 112902 (2006)]). In the present paper, which is intended as a sequel, it is concluded from FAST satellite data that the electrostatic ion-cyclotron turbulence that appears is due to the operation of an electron, bump-on-tail-driven ion-cyclotron instability for downward currents in the long-range potential region of the Earth's magnetosphere. Approximate closed-form expressions for the anomalous momentum and energy transfer rates for the ion-cyclotron turbulence are obtained. The turbulent, inhomogeneous, nonuniformly magnetized, multimoment fluid theory given above, in the limit of a turbulent, homogeneous, uniformly magnetized, quasisteady plasma, yields the well-known formula for the anomalous resistivity given by Gary and Paul [Phys. Rev. Lett. 26, 1097 (1971)] and Tange and Ichimaru [J. Phys. Soc. Jpn. 36, 1437 (1974)].

  3. Large Momentum Transfer Measurements of the Deuteron Elastic Structure Function A(Q^2) at Jefferson Laboratory

    Microsoft Academic Search

    L. C. Alexa; B. D. Anderson; K. A. Aniol; K. Arundell; L. Auerbach; F. T. Baker; J. Berthot; P. Y. Bertin; W. Bertozzi; L. Bimbot; W. U. Boeglin; E. J. Brash; V. Breton; H. Breuer; E. Burtin; J. R. Calarco; L. S. Cardman; C. Cavata; C. Chang; E. Chudakov; E. Cisbani; D. S. Dale; N. Degrande; R. De Leo; A. Deur; N. d'Hose; B. Diederich; J. J. Domingo; M. B. Epstein; L. A. Ewell; J. M. Finn; K. G. Fissum; H. Fonvieille; B. Frois; S. Frullani; H. Gao; J. Gao; F. Garibaldi; A. Gasparian; S. Gilad; R. Gilman; A. Glamazdin; C. Glashausser; J. Gomez; V. Gorbenko; J.-O. Hansen; R. Holmes; M. Holtrop; C. Howell; G. M. Huber; C. Hyde-Wright; M. Iodice; C. W. de Jager; S. Jaminion; J. Jardillier; M. K. Jones; C. Jutier; W. Kahl; S. Kato; A. T. Katramatou; J. J. Kelly; A. Ketikyan; M. Khayat; K. Kino; L. H. Kramer; K. S. Kumar; G. Kumbartzki; M. Kuss; G. Lavessiere; A. Leone; J. J. LeRose; M. Liang; R. A. Lindgren; N. Liyanage; G. J. Lolos; R. W. Lourie; R. Madey; K. Maeda; S. Malov; D. M. Manley; D. J. Margaziotis; P. Markowitz; J. Marroncle; J. Martino; C. J. Martoff; K. McCormick; J. McIntyre; S. Mehrabyan; E. Meziani; R. Michaels; G. W. Miller; J. Y. Mougey; S. K. Nanda; D. Neyret; E. A. J. M. Offermann; Z. Papandreou; C. F. Perdrisat; R. Perrino; G. G. Petratos; S. Platchkov; R. Pomatsalyuk; D. L. Prout; V. A. Punjabi; T. Pussieux; G. Quemener; R. D. Ransome; O. Ravel; Y. Roblin; D. Rowntree; G. Rutledge; P. M. Rutt; A. Saha; T. Saito; A. J. Sarty; A. Serdarevic; T. Smith; K. Soldi; P. Sorokin; P. A. Souder; R. Suleiman; J. A. Templon; T. Terasawa; L. Todor; H. Tsubota; H. Ueno; G. M. Urciuoli; L. Van Hoorebeke; P. Vernin; B. Vlahovic; H. Voskanyan; J. W. Watson; L. B. Weinstein; K. Wijesooriya; R. Wilson; B. B. Wojtsekhowski; D. G. Zainea; J. Zhao; Z.-L. Zhou

    1998-01-01

    The deuteron elastic structure function A(Q^2) has been extracted in the Q^2\\u000arange 0.7 to 6.0 (GeV\\/c)^2 from cross section measurements of elastic\\u000aelectron-deuteron scattering in coincidence using the Hall A Facility of\\u000aJefferson Laboratory. The data are compared to theoretical models based on the\\u000aimpulse approximation with inclusion of meson-exchange currents, and to\\u000apredictions of quark dimensional scaling and

  4. Measurements of the meson-photon transition form factors of light pseudoscalar mesons at large momentum transfer

    E-print Network

    Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan

    1998-01-01

    two-photon processes. The process e1e2!e1e2 f 2(1270) followed by the decay f 2(1270)!p0p0 is the most likely source of the feed-down for the p0!gg analysis. To estimate the feed-down from this process, we remove the cut on the energy of the fourth... misidentification probability for the feed-down from the decay f 2(1270)!p0p0 depends on the relative strengths of the couplings between the tensor meson and two spacelike photons of various total helicity @determined in the 57 MEASUREMENTS OF THE MEcenter...

  5. Evaluating knowledge transfer and zero-shot learning in a large-scale setting

    Microsoft Academic Search

    Marcus Rohrbach; Michael Stark; Bernt Schiele

    2011-01-01

    While knowledge transfer (KT) between object classes has been accepted as a promising route towards scalable recognition, most experimental KT studies are surprisingly limited in the number of object classes considered. To support claims of KT w.r.t. scalability we thus advocate to evaluate KT in a large-scale setting. To this end, we provide an extensive evaluation of three popular approaches

  6. On Performance-Adaptive flow control for large data transfer in high speed networks

    Microsoft Academic Search

    Xukang Lu; Qishi Wu; Nageswara S. V. Rao; Zongmin Wang

    2009-01-01

    Several research and production high-performance networks now provision multi-Gbps dedicated channels to meet the demands of large data transfers in network-intensive applications. However, end users have not seen corresponding increase in application throughput mainly because (i) the existence of high-bandwidth links has shifted the congestion from the network to end hosts, and (ii) such congestion is not well handled by

  7. Cryogenic voltage withstand and heat transfer tests for the General Electric large coil turn heaters

    Microsoft Academic Search

    S. W. Schwenterly; C. M. Fitzpatrick; W. R. Court

    1981-01-01

    In order to assess the stability of the various Large Coil Program concepts, each of the three U.S.-made coils incorporates heaters to create a normal zone in the conductor. Based on results of finite-element heat transfer calculations, voltages in the neighborhood of 1 kV are needed to supply the required power over a half-turn. By comparing the results with room-temperature

  8. Mass transfer characteristics in a large-scale slurry bubble column reactor with organic liquid mixtures

    Microsoft Academic Search

    Arsam Behkish; Zhuowu Men; Juan R. Inga; Badie I. Morsi

    2002-01-01

    The mass transfer coefficients (kLa) and bubbles size distribution were measured in a large-scale (0.316-m inside diameter, 2.8-m high) slurry bubble column reactor (SBCR) for H2, CO, N2 and CH4 in two organic liquid mixtures (Isopar-M and a hexanes mixture) in the presence and absence of two solids (iron oxides catalyst and glass beads) in a wide range of pressure

  9. Micro- and nanoscale electrical characterization of large-area graphene transferred to functional substrates

    PubMed Central

    Fisichella, Gabriele; Di Franco, Salvatore; Fiorenza, Patrick; Lo Nigro, Raffaella; Roccaforte, Fabrizio; Tudisco, Cristina; Condorelli, Guido G; Piluso, Nicolò; Spartà, Noemi; Lo Verso, Stella; Accardi, Corrado; Tringali, Cristina; Ravesi, Sebastiano

    2013-01-01

    Summary Chemical vapour deposition (CVD) on catalytic metals is one of main approaches for high-quality graphene growth over large areas. However, a subsequent transfer step to an insulating substrate is required in order to use the graphene for electronic applications. This step can severely affect both the structural integrity and the electronic properties of the graphene membrane. In this paper, we investigated the morphological and electrical properties of CVD graphene transferred onto SiO2 and on a polymeric substrate (poly(ethylene-2,6-naphthalene dicarboxylate), briefly PEN), suitable for microelectronics and flexible electronics applications, respectively. The electrical properties (sheet resistance, mobility, carrier density) of the transferred graphene as well as the specific contact resistance of metal contacts onto graphene were investigated by using properly designed test patterns. While a sheet resistance R sh ? 1.7 k?/sq and a specific contact resistance ?c ? 15 k?·?m have been measured for graphene transferred onto SiO2, about 2.3× higher R sh and about 8× higher ?c values were obtained for graphene on PEN. High-resolution current mapping by torsion resonant conductive atomic force microscopy (TRCAFM) provided an insight into the nanoscale mechanisms responsible for the very high ?c in the case of graphene on PEN, showing a ca. 10× smaller “effective” area for current injection than in the case of graphene on SiO2. PMID:23616943

  10. Relative intensity noise transfer of large-bandwidth pump lasers in Raman fiber amplifiers

    NASA Astrophysics Data System (ADS)

    Keita, Kafing; Delaye, Philippe; Frey, Robert; Roosen, Gérald

    2006-12-01

    A theoretical analysis of the Raman amplification in optical fibers and the pump-to-signal relative intensity noise (RIN) transfer has been performed in the spectral domain. An efficient Raman amplification of a monochromatic signal beam by a large-bandwidth pump beam has been demonstrated for a pump bandwidth much smaller than the Raman linewidth. Under the same approximation the pump-to-signal RIN transfer has been calculated in both cases of copropagating and counterpropagating beams in the two limiting cases of modulated monochromatic and smooth-profile large-bandwidth pump beams. At low frequencies the excess of noise evidenced in the case of a modulated monochromatic pump beam did not exist in the case of large-bandwidth pseudoincoherent sources. As this noise reduction can be as large as 13 dB for a 40 dB net gain of the amplifier, such incoherent pumping sources must be considered for the purpose of low-noise Raman amplifiers.

  11. Condensation by DNA looping facilitates transfer of large DNA molecules into mammalian cells

    PubMed Central

    Montigny, William J.; Houchens, Christopher R.; Illenye, Sharon; Gilbert, Jonathan; Coonrod, Emily; Chang, Young-Chae; Heintz, Nicholas H.

    2001-01-01

    Experimental studies of complete mammalian genes and other genetic domains are impeded by the difficulty of introducing large DNA molecules into cells in culture. Previously we have shown that GST–Z2, a protein that contains three zinc fingers and a proline-rich multimerization domain from the polydactyl zinc finger protein RIP60 fused to glutathione S-transferase (GST), mediates DNA binding and looping in vitro. Atomic force microscopy showed that GST–Z2 is able to condense 130–150 kb bacterial artificial chromosomes (BACs) into protein–DNA complexes containing multiple DNA loops. Condensation of the DNA loops onto the Z2 protein–BAC DNA core complexes with cationic lipid resulted in particles that were readily transferred into multiple cell types in culture. Transfer of total genomic linear DNA containing amplified DHFR genes into DHFR– cells by GST–Z2 resulted in a 10-fold higher transformation rate than calcium phosphate co-precipitation. Chinese hamster ovarian cells transfected with a BAC containing the human TP53 gene locus expressed p53, showing native promoter elements are active after GST–Z2-mediated gene transfer. Because DNA condensation by GST–Z2 does not require the introduction of specific recognition sequences into the DNA substrate, condensation by the Z2 domain of RIP60 may be used in conjunction with a variety of other agents to provide a flexible and efficient non-viral platform for the delivery of large genes into mammalian cells. PMID:11328883

  12. Large scale metal-free synthesis of graphene on sapphire and transfer-free device fabrication

    NASA Astrophysics Data System (ADS)

    Song, Hyun Jae; Son, Minhyeok; Park, Chibeom; Lim, Hyunseob; Levendorf, Mark P.; Tsen, Adam W.; Park, Jiwoong; Choi, Hee Cheul

    2012-05-01

    Metal catalyst-free growth of large scale single layer graphene film on a sapphire substrate by a chemical vapor deposition (CVD) process at 950 °C is demonstrated. A top-gated graphene field effect transistor (FET) device is successfully fabricated without any transfer process. The detailed growth process is investigated by the atomic force microscopy (AFM) studies.Metal catalyst-free growth of large scale single layer graphene film on a sapphire substrate by a chemical vapor deposition (CVD) process at 950 °C is demonstrated. A top-gated graphene field effect transistor (FET) device is successfully fabricated without any transfer process. The detailed growth process is investigated by the atomic force microscopy (AFM) studies. Electronic supplementary information (ESI) available: Experimental details, transmittance of graphene films, schematic illustration of the growth process, schematic of the ?-Al2O3 (0001) substrate, Raman spectra and AFM images of graphene grown on ?-Al2O3 (112\\cmb.macr 0) and ST-cut quartz substrates, optical image and Raman spectrum of graphene transferred to the SiO2 (300 nm)/Si substrate. See DOI: 10.1039/c2nr30330b

  13. Electron collisions with phenol: Total, integral, differential, and momentum transfer cross sections and the role of multichannel coupling effects on the elastic channel

    NASA Astrophysics Data System (ADS)

    da Costa, Romarly F.; de Oliveira, Eliane M.; Bettega, Márcio H. F.; Varella, Márcio T. do N.; Jones, Darryl B.; Brunger, Michael J.; Blanco, Francisco; Colmenares, Rafael; Limão-Vieira, Paulo; García, Gustavo; Lima, Marco A. P.

    2015-03-01

    We report theoretical and experimental total cross sections for electron scattering by phenol (C6H5OH). The experimental data were obtained with an apparatus based in Madrid and the calculated cross sections with two different methodologies, the independent atom method with screening corrected additivity rule (IAM-SCAR), and the Schwinger multichannel method with pseudopotentials (SMCPP). The SMCPP method in the Nopen-channel coupling scheme, at the static-exchange-plus-polarization approximation, is employed to calculate the scattering amplitudes at impact energies ranging from 5.0 eV to 50 eV. We discuss the multichannel coupling effects in the calculated cross sections, in particular how the number of excited states included in the open-channel space impacts upon the convergence of the elastic cross sections at higher collision energies. The IAM-SCAR approach was also used to obtain the elastic differential cross sections (DCSs) and for correcting the experimental total cross sections for the so-called forward angle scattering effect. We found a very good agreement between our SMCPP theoretical differential, integral, and momentum transfer cross sections and experimental data for benzene (a molecule differing from phenol by replacing a hydrogen atom in benzene with a hydroxyl group). Although some discrepancies were found for lower energies, the agreement between the SMCPP data and the DCSs obtained with the IAM-SCAR method improves, as expected, as the impact energy increases. We also have a good agreement among the present SMCPP calculated total cross section (which includes elastic, 32 inelastic electronic excitation processes and ionization contributions, the latter estimated with the binary-encounter-Bethe model), the IAM-SCAR total cross section, and the experimental data when the latter is corrected for the forward angle scattering effect [Fuss et al., Phys. Rev. A 88, 042702 (2013)].

  14. Electron collisions with phenol: Total, integral, differential, and momentum transfer cross sections and the role of multichannel coupling effects on the elastic channel.

    PubMed

    da Costa, Romarly F; de Oliveira, Eliane M; Bettega, Márcio H F; Varella, Márcio T do N; Jones, Darryl B; Brunger, Michael J; Blanco, Francisco; Colmenares, Rafael; Limão-Vieira, Paulo; García, Gustavo; Lima, Marco A P

    2015-03-14

    We report theoretical and experimental total cross sections for electron scattering by phenol (C6H5OH). The experimental data were obtained with an apparatus based in Madrid and the calculated cross sections with two different methodologies, the independent atom method with screening corrected additivity rule (IAM-SCAR), and the Schwinger multichannel method with pseudopotentials (SMCPP). The SMCPP method in the Nopen-channel coupling scheme, at the static-exchange-plus-polarization approximation, is employed to calculate the scattering amplitudes at impact energies ranging from 5.0 eV to 50 eV. We discuss the multichannel coupling effects in the calculated cross sections, in particular how the number of excited states included in the open-channel space impacts upon the convergence of the elastic cross sections at higher collision energies. The IAM-SCAR approach was also used to obtain the elastic differential cross sections (DCSs) and for correcting the experimental total cross sections for the so-called forward angle scattering effect. We found a very good agreement between our SMCPP theoretical differential, integral, and momentum transfer cross sections and experimental data for benzene (a molecule differing from phenol by replacing a hydrogen atom in benzene with a hydroxyl group). Although some discrepancies were found for lower energies, the agreement between the SMCPP data and the DCSs obtained with the IAM-SCAR method improves, as expected, as the impact energy increases. We also have a good agreement among the present SMCPP calculated total cross section (which includes elastic, 32 inelastic electronic excitation processes and ionization contributions, the latter estimated with the binary-encounter-Bethe model), the IAM-SCAR total cross section, and the experimental data when the latter is corrected for the forward angle scattering effect [Fuss et al., Phys. Rev. A 88, 042702 (2013)]. PMID:25770537

  15. Large-Deformation Displacement Transfer Functions for Shape Predictions of Highly Flexible Slender Aerospace Structures

    NASA Technical Reports Server (NTRS)

    Ko, William L.; Fleischer, Van Tran

    2013-01-01

    Large deformation displacement transfer functions were formulated for deformed shape predictions of highly flexible slender structures like aircraft wings. In the formulation, the embedded beam (depth wise cross section of structure along the surface strain sensing line) was first evenly discretized into multiple small domains, with surface strain sensing stations located at the domain junctures. Thus, the surface strain (bending strains) variation within each domain could be expressed with linear of nonlinear function. Such piecewise approach enabled piecewise integrations of the embedded beam curvature equations [classical (Eulerian), physical (Lagrangian), and shifted curvature equations] to yield closed form slope and deflection equations in recursive forms.

  16. Cyclododecane as support material for clean and facile transfer of large-area few-layer graphene

    NASA Astrophysics Data System (ADS)

    Capasso, A.; De Francesco, M.; Leoni, E.; Dikonimos, T.; Buonocore, F.; Lancellotti, L.; Bobeico, E.; Sarto, M. S.; Tamburrano, A.; De Bellis, G.; Lisi, N.

    2014-09-01

    The transfer of chemical vapor deposited graphene is a crucial process, which can affect the quality of the transferred films and compromise their application in devices. Finding a robust and intrinsically clean material capable of easing the transfer of graphene without interfering with its properties remains a challenge. We here propose the use of an organic compound, cyclododecane, as a transfer material. This material can be easily spin coated on graphene and assist the transfer, leaving no residues and requiring no further removal processes. The effectiveness of this transfer method for few-layer graphene on a large area was evaluated and confirmed by microscopy, Raman spectroscopy, x-ray photoemission spectroscopy, and four-point probe measurements. Schottky-barrier solar cells with few-layer graphene were fabricated on silicon wafers by using the cyclododecane transfer method and outperformed reference cells made by standard methods.

  17. Cyclododecane as support material for clean and facile transfer of large-area few-layer graphene

    SciTech Connect

    Capasso, A.; Leoni, E.; Dikonimos, T.; Buonocore, F.; Lisi, N. [ENEA, Materials Technology Unit, Surface Technology Laboratory, Casaccia Research Centre, Via Anguillarese 301, 00060 Rome (Italy); De Francesco, M. [ENEA, Technical Unit for Renewable Energies Sources, Casaccia Research Center, Via Anguillarese 301, 00060 Rome (Italy); Lancellotti, L.; Bobeico, E. [ENEA, Portici Research Centre, P.le E. Fermi 1, 80055 Portici (Italy); Sarto, M. S.; Tamburrano, A.; De Bellis, G. [Research Center on Nanotechnology Applied to Engineering of Sapienza (CNIS), SSNLab, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome (Italy)

    2014-09-15

    The transfer of chemical vapor deposited graphene is a crucial process, which can affect the quality of the transferred films and compromise their application in devices. Finding a robust and intrinsically clean material capable of easing the transfer of graphene without interfering with its properties remains a challenge. We here propose the use of an organic compound, cyclododecane, as a transfer material. This material can be easily spin coated on graphene and assist the transfer, leaving no residues and requiring no further removal processes. The effectiveness of this transfer method for few-layer graphene on a large area was evaluated and confirmed by microscopy, Raman spectroscopy, x-ray photoemission spectroscopy, and four-point probe measurements. Schottky-barrier solar cells with few-layer graphene were fabricated on silicon wafers by using the cyclododecane transfer method and outperformed reference cells made by standard methods.

  18. Visualizing the dynamic of adoptively transferred T cells during the rejection of large established tumors.

    PubMed

    Charo, Jehad; Perez, Cynthia; Buschow, Christian; Jukica, Ana; Czeh, Melinda; Blankenstein, Thomas

    2011-11-01

    Adoptive T-cell therapy (ATCT) can result in tumor rejection, yet the behavior and fate of the introduced T cells remain unclear. We developed a novel bioluminescence mouse model, which enabled highly sensitive detection of T-cell signals at the single-cell level. Transferred T cells preferentially accumulated within antigen-positive tumors, relative to the unaffected areas in each mouse, and remarkably, expanded within both lymphopenic and P14 mice. This expansion was controlled and efficient, as evaluated by bioluminescence imaging (BLI) of the T-cell signals and by tumor rejection respectively. Analysis of the population dynamics of transferred T cells in ATCT of large tumors revealed that proliferation did not always follow a simple linear pattern of expansion, but showed an oscillating pattern of expansion and contraction that was often followed by a rebound, until full tumor rejection was achieved. Furthermore, visualizing the recall response showed that the transferred T cells responded expeditiously, indicating the ability of these cells to survive, establish memory and compete with endogenous T cells for as long as 1 year after rejecting the tumor. PMID:21898380

  19. Journal of Crystal Growth 194 (1998) 321--330 Combined heat transfer in floating zone growth of large silicon

    E-print Network

    Guo, Zhixiong "James"

    1998-01-01

    Journal of Crystal Growth 194 (1998) 321--330 Combined heat transfer in floating zone growth the combined heat transfer in floating zone growth of large Si crystals with needle-eye technique factors associated with the components in the float zone furnace and both the diffuse and specular

  20. A computational study of the convergence of large angular momentum, high current ion beams in an inertial electrostatic confinement (IEC) device

    SciTech Connect

    Tzonev, I.V.; Miley, G.H. [Fusion Studies Laboratory, Urbana, IL (United States)

    1995-12-31

    The IEC fusion device is a spherical electrostatic confinement device in which a high negative potential is applied to a spherical cathode wire grid. The plasma ions are radially accelerated towards the negatively biased grid and eventually collide and fuse in the grid geometric center of the volume circumscribed by the grid. Hirsch`s solution of Poison equation for the monoenergetic ion and electron distribution functions and no ion and electron angular momentum shows the formation of spatially periodic virtual anodes and virtual cathodes -- multiple wells or {open_quotes}Poissors{close_quotes}. The formation of deep and stable double potential wells is essential for good ion convergence, and hence the successful development of the IEC device as a future power source. The ions are trapped in the negative second well in the center of the device in a very small volume, thus forming a high density plasma core where high fusion rates can be achieved. Inertial electrostatic confinement has been extensively studied. No one has concentrated on high-current, high-angular-momentum ion beams. Large -angular- momentum, high-current ion beams have been investigated and shown to be essential for the formation of deep double potential wells. Simulations were done using the DCL code - a one-dimensional electrostatic Poisson-Vlasov equation solver. The IXL code which does not consider electron and ion collisions, represents an important limiting case where space charge effects dominate. The calculations were done for an experimental scenario using deuterium gas fuel. The most important input parameters of the code are the electron and ion injection energies - (E{sub inj,i}, E{sub inj,e}), the ion and electron total ion currents, including the number of recirculation`s through the grid - (I{sub e} and I{sub i}) , the radial and perpendicular ion and electron energy spread- (dE{sub inj,i}, dE{sub inj,e}, dE{sub perp,i}, dE{sub perp,e}), and the cathode grid potential and position.

  1. Development of process to transfer large areas of LPCVD graphene from copper foil to a porous support substrate

    E-print Network

    O'Hern, Sean C. (Sean Carson)

    2011-01-01

    In this thesis, I present a procedure by which to transfer greater than 25 mm² areas of high-quality graphene synthesized via low-pressure chemical vapor deposition from copper foil to porous support substrates. Large-area, ...

  2. Large Quantum Probability Backflow and the Azimuthal Angle-Angular Momentum Uncertainty Relation for an Electron in a Constant Magnetic Field

    ERIC Educational Resources Information Center

    Strange, P.

    2012-01-01

    In this paper we demonstrate a surprising aspect of quantum mechanics that is accessible to an undergraduate student. We discuss probability backflow for an electron in a constant magnetic field. It is shown that even for a wavepacket composed entirely of states with negative angular momentum the effective angular momentum can take on positive…

  3. Positrons for Antihydrogen with ATRAP: efficient transfer of large positron numbers

    NASA Astrophysics Data System (ADS)

    Storry, Cody; Comeau, Daniel; Dror, Asaf; Fitzakerley, Daniel; George, Matthew; Hessels, Eric; Weel, Matthew

    2012-06-01

    Positrons accumulated in a room-temperature buffer-gas-cooled positron accumulator are efficiently transferred into a superconducting solenoid which houses the ATRAP cryogenic Penning trap for antihydrogen research. The positrons are guided along a 9-meter-long magnetic guide which connects the central field lines of the 0.15-tesla field in the positron accumulator to central magnetic field lines of the superconducting solenoid. Seventy independently-controllable electromagnets are required to overcome the fringing field of the large-bore superconducting solenoid. The guide includes both a 15 degree upward bend and a 105 degree downward bend to account for the orthogonal orientation of the accumulator with respect to the cryogenic Penning trap. Low-energy positrons ejected from the accumulator follow the magnetic field lines within the guide and are transferred into the superconducting solenoid with nearly 100% efficiency. 7 meters of 5-cm-diameter stainless-steel tube, and a 20-mm-long, 1.5-mm-diameter cryogenic pumping restriction ensure that the 10-2 mbar pressure in the accumulator is well isolated from the extreme vacuum required in the Penning trap to allow long antimatter storage times.

  4. Rapidity and species dependence of particle production at large transverse momentum for d+Au collisions at sNN=200 GeV

    NASA Astrophysics Data System (ADS)

    Abelev, B. I.; Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Anderson, M.; Arkhipkin, D.; Averichev, G. S.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Bekele, S.; Belaga, V. V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Bhardwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Blyth, S.-L.; Bonner, B. E.; Botje, M.; Bouchet, J.; Brandin, A. V.; Bravar, A.; Bystersky, M.; Cadman, R. V.; Cai, X. Z.; Caines, H.; Sánchez, M. Calderón De La Barca; Castillo, J.; Catu, O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J. P.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Das, S.; Daugherity, M.; Moura, M. M. De; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; Didenko, L.; Dietel, T.; Djawotho, P.; Dogra, S. M.; Dong, W. J.; Dong, X.; Draper, J. E.; Du, F.; Dunin, V. B.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Eckardt, V.; Edwards, W. R.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C. A.; Gaillard, L.; Ganti, M. S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J. E.; Gorbunov, Y. G.; Gos, H.; Grebenyuk, O.; Grosnick, D.; Guertin, S. M.; Guimaraes, K. S. F. F.; Guo, Y.; Gupta, N.; Gutierrez, T. D.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Henry, T. W.; Hepplemann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Horner, M. J.; Huang, H. Z.; Huang, S. L.; Hughes, E. W.; Humanic, T. J.; Igo, G.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P. G.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev, V. Yu.; Kim, B. C.; Kiryluk, J.; Kisiel, A.; Kislov, E. M.; Klein, S. R.; Kocoloski, A.; Koetke, D. D.; Kollegger, T.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kowalik, K. L.; Kramer, M.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kumar, A.; Kuznetsov, A. A.; Lamont, M. A. C.; Landgraf, J. M.; Lange, S.; Lapointe, S.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lehocka, S.; Levine, M. J.; Li, C.; Li, Q.; Li, Y.; Lin, G.; Lin, X.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Liu, Z.; Ljubicic, T.; Llope, W. J.; Long, H.; Longacre, R. S.; Lopez-Noriega, M.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, J. G.; Ma, Y. G.; Magestro, D.; Mahapatra, D. P.; Majka, R.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Martin, L.; Matis, H. S.; Matulenko, Yu. A.; McClain, C. J.; McShane, T. S.; Melnick, Yu.; Meschanin, A.; Millane, J.; Miller, M. L.; Minaev, N. G.; Mioduszewski, S.; Mironov, C.; Mischke, A.; Mishra, D. K.; Mitchell, J.; Mohanty, B.; Molnar, L.; Moore, C. F.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Netrakanti, P. K.; Nikitin, V. A.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Pachr, M.; Pal, S. K.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Petrov, V. A.; Phatak, S. C.; Picha, R.; Planinic, M.; Pluta, J.; Poljak, N.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potekhin, M.; Potrebenikova, E.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Putschke, J.; Rakness, G.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Razin, S. V.; Reinnarth, J.; Relyea, D.; Retiere, F.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Sahoo, R.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Sazhin, P. S.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schweda, K.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shen, W. Q.; Shimanskiy, S. S.; Sichtermann, E.; Simon, F.; Singaraju, R. N.; Smirnov, N.; Snellings, R.; Sood, G.; Sorensen, P.; Sowinski, J.; Speltz, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Sugarbaker, E.; Sumbera, M.; Sun, Z.; Surrow, B.; Swanger, M.; Symons, T. J. M.; Toledo, A. Szanto De; Tai, A.; Takahashi, J.; Tang, A. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Timmins, A. R.; Timoshenko, S.; Tokarev, M.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Buren, G. Van; Kolk, N. Van Der; Leeuwen, M. Van; Molen, A. M. Vander; Varma, R.; Vasilevski, I. M.

    2007-11-01

    We determine rapidity asymmetry in the production of charged pions, protons, and antiprotons for large transverse momentum (pT) for d+Au collisions at sNN=200 GeV. The rapidity asymmetry is defined as the ratio of particle yields at backward rapidity (Au beam direction) to those at forward rapidity (d beam direction). The identified hadrons are measured in the rapidity regions |y|<0.5 and 0.5<|y|<1.0 for the pT range 2.5

  5. Conjugate heat transfer with Large Eddy Simulation for gas turbine components

    NASA Astrophysics Data System (ADS)

    Duchaine, Florent; Mendez, Simon; Nicoud, Franck; Corpron, Alban; Moureau, Vincent; Poinsot, Thierry

    2009-06-01

    CHT (Conjugate Heat Transfer) is a main design constraint for GT (gas turbines). Most existing CHT tools are developed for chained, steady phenomena. A fully parallel environment for CHT has been developed and applied to two configurations of interest for the design of GT. A reactive Large Eddy Simulations code and a solid conduction solver exchange data via a supervisor. A flame/wall interaction is used to assess the precision and the order of the coupled solutions. A film-cooled turbine vane is then studied. Thermal conduction in the blade implies lower wall temperature than adiabatic results and CHT reproduces the experimental cooling efficiency. To cite this article: F. Duchaine et al., C. R. Mecanique 337 (2009).

  6. Charge transfer and in-cloud structure of large-charge-moment positive lightning strokes in a mesoscale convective system

    E-print Network

    Cummer, Steven A.

    Charge transfer and in-cloud structure of large-charge-moment positive lightning strokes positive cloud-to-ground (+CG) strokes in a mesoscale convective system. Although no high altitude images were recorded, these strokes contained large charge moment changes (1500­3200 CÁkm) capable

  7. Large Ground-State Entropy Changes for Hydrogen Atom Transfer Reactions of Iron Complexes

    PubMed Central

    Mader, Elizabeth A.; Davidson, Ernest R.

    2008-01-01

    Reported herein are the hydrogen atom transfer (HAT) reactions of two closely related dicationic iron tris ?-diimine complexes. FeII(H2bip) (iron(II) tris[2,2?-bi-1,4,5,6-tetra-hydropyrimidine]diperchlorate) and FeII(H2bim) (iron(II) tris[2,2?-bi-2-imidazoline]diperchlorate) both transfer H• to TEMPO (2,2,6,6-tetramethyl-1-piperidinoxyl) to yield the hydroxylamine, TEMPO-H, and the respective deprotonated iron(III) species, FeIII(Hbip) or FeIII(Hbim). The ground-state thermodynamic parameters in MeCN were determined for both systems using both static and kinetic measurements. For FeII(H2bip) + TEMPO: ?G° = ?0.3 ± 0.2 kcal mol?1, ?H° =?9.4 ± 0.6 kcal mol?1, ?S° = ?30 ± 2 cal mol?1 K?1. For FeII(H2bim) + TEMPO: ?G° = 5.0 ± 0.2 kcal mol?1, ?H° = ?4.1 ± 0.9 kcal mol?1, ?S° = ?30 ± 3 cal mol?1 K?1. The large entropy changes for these reactions, |T?S°| = 9 kcal mol?1 at 298 K, are exceptions to the traditional assumption that ?S° ? 0 for simple HAT reactions. Various studies indicate that hydrogen-bonding, solvent effects, ion-pairing, and iron spin-equilibria do not make major contributions to the observed ?S°HAT. Instead, this effect arises primarily from changes in vibrational entropy upon oxidation of the iron center. Measurement of the electron transfer half-reaction entropy, |?S° Fe(H2bim)/ET| = 29 ± 3 cal mol?1 K?1, is consistent with a vibrational origin. This conclusion is supported by UHF/6-31G* calculations on the simplified reaction [FeII(H2N=CHCH=NH2)2(H2bim)]2+•••ONH2 ? [FeII(H2N=CHCH=NH2)2(Hbim)]2+•••HONH2. The discovery that ?S°HAT can deviate significantly from zero has important implications on the study of HAT and proton-coupled electron transfer (PCET) reactions. For instance, these results indicate that free energies, rather than enthalpies, should be used to estimate the driving force for HAT when transition metal centers are involved. PMID:17402735

  8. Transfers

    Microsoft Academic Search

    Xavier Sala-i-Martin

    1992-01-01

    In this paper I develop a positive theory of intergenerational transfers. I argue that transfers are a means to induce retirement. that is, to buy the elderly out of the labor force. The reason why societies choose to do such a thing is that aggregate output is higher if the elderly do not work. I model this idea through positive

  9. Search for events with large missing transverse momentum, jets, and at least two tau leptons in 7 TeV proton–proton collision data with the ATLAS detector

    E-print Network

    Taylor, Frank E.

    A search for events with large missing transverse momentum, jets, and at least two tau leptons has been performed using 2 fb[superscript ?1] of proton–proton collision data at ?s = 7 TeV recorded with the ATLAS detector ...

  10. Search for diphoton events with large missing transverse momentum in 1 fb[superscript -1] of 7 TeV proton–proton collision data with the ATLAS detector

    E-print Network

    Taylor, Frank E.

    A search for diphoton events with large missing transverse momentum has been performed using 1.07 fb[superscript ?1] of proton–proton collision data at ?s = 7 TeV recorded with the ATLAS detector. No excess of events was ...

  11. The Local Helium Compound Transfer Lines for the Large Hadron Collider Cryogenic System

    NASA Astrophysics Data System (ADS)

    Parente, C.; Allen, W.; Munday, A.; Wiggins, P.

    2006-04-01

    The cryogenic system for the Large Hadron Collider (LHC) under construction at CERN will include twelve new local helium transfer lines distributed among five LHC points in underground caverns. These lines, being manufactured and installed by industry, will connect the cold boxes of the 4.5-K refrigerators and the 1.8-K refrigeration units to the cryogenic interconnection boxes. The lines have a maximum of 30-m length and may possess either small or large re-distribution units to allow connection to the interface ports. Due to space restrictions the lines may have complex routings and require several elbowed sections. The lines consist of a vacuum jacket, a thermal shield and either three or four helium process pipes. Specific internal and external supporting and compensation systems were designed for each line to allow for thermal contraction of the process pipes (or vacuum jacket, in case of a break in the insulation vacuum) and to minimise the forces applied to the interface equipment. Whenever possible, flexible hoses were used instead of bellows to allow for thermal compensation of the process pipes. If necessary, compensation units were integrated in the vacuum jacket. The thermal design was performed to fulfil the specified heat-load budget. This paper presents the main technical design choices for the lines together with their expected performance.

  12. 496. Recombinant Sendai Virus Vector to Evaluate Vector Distribution in a Large Animal Model of Lung Gene Transfer

    Microsoft Academic Search

    Gerry McLachlan; Uta Griesenbach; Toshi Owaki; Liz Hillery; John Williams; Zhu Yafeng; Chris Boyd; Deborah Gill; Mamoru Hasegawa; Eric W. F. W. Alton; David Collie

    2004-01-01

    We have described gene delivery in sheep as a large animal model for airway gene transfer. This model allows comparison of different GTAs in terms of efficacy and safety using doses, delivery methods and assays, relevant to human studies. Proof-of-principle for non-viral gene transfer has been established however, levels of transgene expression are too low on a per cell basis

  13. Angular momentum

    NASA Astrophysics Data System (ADS)

    Shakur, Asif; Sinatra, Taylor

    2013-12-01

    The gyroscope in a smartphone was employed in a physics laboratory setting to verify the conservation of angular momentum and the nonconservation of rotational kinetic energy. As is well-known, smartphones are ubiquitous on college campuses. These devices have a panoply of built-in sensors. This creates a unique opportunity for a new paradigm in the physics laboratory. Many traditional physics experiments can now be performed very conveniently in a pedagogically enlightening environment while simultaneously reducing the laboratory budget substantially by using student-owned smartphones.

  14. Centrality Dependence of Charged Particle Production at Large Transverse Momentum in Pb--Pb Collisions at $\\\\sqrt{s_{\\\\rm{NN}}} = 2.76$ TeV

    Microsoft Academic Search

    Betty Abelev; Jaroslav Adam; Dagmar Adamova; Andrew Marshall Adare; Madan Aggarwal; Gianluca Aglieri Rinella; Andras Gabor Agocs; Andrea Agostinelli; Saul Aguilar Salazar; Zubayer Ahammed; Nazeer Ahmad; Arshad Ahmad; Sul-Ah Ahn; Sang Un Ahn; Alexander Akindinov; Dmitry Aleksandrov; Bruno Alessandro; Jose Ruben Alfaro Molina; Andrea Alici; Anton Alkin; Erick Jonathan Almaraz Avina; Johan Alme; Torsten Alt; Valerio Altini; Sedat Altinpinar; Igor Altsybeev; Cristian Andrei; Anton Andronic; Venelin Anguelov; Jonas Anielski; Christopher Daniel Anson; Tome Anticic; Federico Antinori; Pietro Antonioli; Laurent Bernard Aphecetche; Harald Appelshauser; Nicolas Arbor; Silvia Arcelli; Andreas Arend; Nestor Armesto; Roberta Arnaldi; Tomas Robert Aronsson; Ionut Cristian Arsene; Mesut Arslandok; Andzhey Asryan; Andre Augustinus; Ralf Peter Averbeck; Terry Awes; Juha Heikki Aysto; Mohd Danish Azmi; Matthias Jakob Bach; Angela Badala; Yong Wook Baek; Raphaelle Marie Bailhache; Renu Bala; Rinaldo Baldini Ferroli; Alberto Baldisseri; Alain Baldit; Fernando Baltasar Dos Santos Pedrosa; Jaroslav Ban; Rama Chandra Baral; Roberto Barbera; Francesco Barile; Gergely Gabor Barnafoldi; Lee Stuart Barnby; Valerie Barret; Jerzy Gustaw Bartke; Maurizio Basile; Nicole Bastid; Sumit Basu; Bastian Bathen; Guillaume Batigne; Boris Batyunya; Christoph Heinrich Baumann; Ian Gardner Bearden; Hans Beck; Nirbhay Kumar Behera; Iouri Belikov; Francesca Bellini; Rene Bellwied; Ernesto Belmont-Moreno; Gyula Bencedi; Stefania Beole; Ionela Berceanu; Alexandru Bercuci; Yaroslav Berdnikov; Daniel Berenyi; Anais Annick Erica Bergognon; Dario Berzano; Latchezar Betev; Anju Bhasin; Ashok Kumar Bhati; Jihyun Bhom; Livio Bianchi; Nicola Bianchi; Chiara Bianchin; Jaroslav Bielcik; Jana Bielcikova; Ante Bilandzic; Sandro Bjelogrlic; F Blanco; Dmitry Blau; Christoph Blume; Marco Boccioli; Nicolas Bock; Stefan Boettger; Alexey Bogdanov; Hans Boggild; Mikhail Bogolyubsky; Laszlo Boldizsar; Marek Bombara; Herve Borel; Alexander Borissov; Suvendu Nath Bose; Francesco Bossu; Michiel Botje; Elena Botta; Bruno Alexandre Boyer; Ermes Braidot; Peter Braun-Munzinger; Marco Bregant; Timo Gunther Breitner; Tyler Allen Browning; Michal Broz; Rene Brun; Elena Bruna; Giuseppe Eugenio Bruno; Dmitry Budnikov; Henner Buesching; Stefania Bufalino; Oliver Busch; Edith Zinhle Buthelezi; Diego Caballero Orduna; Davide Caffarri; Xu Cai; Helen Louise Caines; Ernesto Calvo Villar; Paolo Camerini; Veronica Canoa Roman; Giovanni Cara Romeo; Francesco Carena; Wisla Carena; Nelson Carlin Filho; Federico Carminati; Amaya Ofelia Casanova Diaz; Javier Ernesto Castillo Castellanos; Juan Francisco Castillo Hernandez; Ester Anna Rita Casula; Vasile Catanescu; Costanza Cavicchioli; Cesar Ceballos Sanchez; Jan Cepila; Piergiorgio Cerello; Beomsu Chang; Sylvain Chapeland; Jean-Luc Fernand Charvet; Subhasis Chattopadhyay; Sukalyan Chattopadhyay; Isha Chawla; Michael Gerard Cherney; Cvetan Cheshkov; Brigitte Cheynis; Vasco Miguel Chibante Barroso; David Chinellato; Peter Chochula; Marek Chojnacki; Subikash Choudhury; Panagiotis Christakoglou; Christian Holm Christensen; Peter Christiansen; Tatsuya Chujo; Suh-Urk Chung; Corrado Cicalo; Luisa Cifarelli; Federico Cindolo; Jean Willy Andre Cleymans; Fabrizio Coccetti; Fabio Colamaria; Domenico Colella; Gustavo Conesa Balbastre; Zaida Conesa del Valle; Paul Constantin; Giacomo Contin; Jesus Guillermo Contreras; Thomas Michael Cormier; Yasser Corrales Morales; Pietro Cortese; Ismael Cortes Maldonado; Mauro Rogerio Cosentino; Filippo Costa; Manuel Enrique Cotallo; Elisabetta Crescio; Philippe Crochet; Emilia Cruz Alaniz; Eleazar Cuautle; Leticia Cunqueiro; Andrea Dainese; Hans Hjersing Dalsgaard; Andrea Danu; Debasish Das; Indranil Das; Kushal Das; Ajay Kumar Dash; Sadhana Dash; Sudipan De; Gabriel de Barros; Annalisa De Caro; Giacinto de Cataldo; Jan de Cuveland; Alessandro De Falco; Daniele De Gruttola; Hugues Delagrange; Andrzej Deloff; Vyacheslav Demanov; Nora De Marco; Ervin Denes; Salvatore De Pasquale; Airton Deppman; Ginevra D'Erasmo; Raoul Stefan de Rooij; Miguel Angel Diaz Corchero; Domenico Di Bari; Thomas Dietel; Carmelo Di Giglio; Sergio Di Liberto; Antonio Di Mauro; Pasquale Di Nezza; Roberto Divia; Oeystein Djuvsland; Alexandru Florin Dobrin; Tadeusz Antoni Dobrowolski; Isabel Dominguez; Benjamin Donigus; Olja Dordic; Olga Driga; Anand Kumar Dubey; Andrea Dubla; Laurent Ducroux; Pascal Dupieux; Mihir Ranjan Dutta Majumdar; AK Dutta Majumdar; Domenico Elia; David Philip Emschermann; Heiko Engel; Barbara Erazmus; Hege Austrheim Erdal

    2012-01-01

    The inclusive transverse momentum (pT) distributions of primary charged particles are measured in the pseudo-rapidity range |$\\\\eta$| < 0.8 as a function of event centrality in Pb–Pb collisions at $\\\\sqrt{s_{NN}}$ = 2.76 TeV with ALICE at the LHC. The data are presented in the transverse momentum range 0.15 < pT < 50 GeV\\/c for nine centrality intervals from 70–80% to

  15. Large-eddy simulation of oxygen transfer to organic sediment beds

    NASA Astrophysics Data System (ADS)

    Scalo, Carlo; Piomelli, Ugo; Boegman, Leon

    2012-06-01

    We have developed a model for dissolved oxygen (DO) transfer from water to underlying organic sediment beds. The model couples large-eddy simulation (LES) of turbulent transport in the water column, a biogeochemical model for DO transport and consumption in the sediment, and Darcy's Law for the pore water-driven transport. The model highlights the spatial and temporal relationship between the turbulent bursting events, the near-wall transport of DO, and the response of the sediment layer. The numerical results—compared to data from laboratory experiments—stress the importance of analyzing instantaneous transport events (not reproducible in a Reynolds-averaged Navier-Stokes model) to better characterize and model the processes that lead to oxygen depletion in the sediment layer. The model's results are compared against experimental data and the sensitivity to the governing parameters has been tested. As the current velocity increases, the sediment-oxygen demand (SOD) increases more slowly than the friction velocity at the wall, in accordance with classic heat-and-mass transfer laws. The overall SOD is approximately proportional to the bacterial content of the sediment layer. The predicted mean advective flux in the porous medium and across the sediment-water interface is negligible compared to the total dispersive flux, for permeabilities typical of the sediments used in the experiments (10-7 and 10-6 cm2). Higher permeabilities (10-5 cm2) appear to yield results not consistent with experimental data. This computational tool will contribute toward the design of a process-oriented parametrization for the SOD, currently missing in oceanographic applications, that can be easily extended to the transport of other bio-limiting substances.

  16. Plasma momentum meter for momentum flux measurements

    DOEpatents

    Zonca, F.; Cohen, S.A.; Bennett, T.; Timberlake, J.R.

    1993-08-24

    An apparatus is described for measuring momentum flux from an intense plasma stream, comprising: refractory target means oriented normal to the flow of said plasma stream for bombardment by said plasma stream where said bombardment by said plasma stream applies a pressure to said target means, pendulum means for communicating a translational displacement of said target to a force transducer where said translational displacement of said target is transferred to said force transducer by an elongated member coupled to said target, where said member is suspended by a pendulum configuration means and where said force transducer is responsive to said translational displacement of said member, and force transducer means for outputting a signal representing pressure data corresponding to said displacement.

  17. Ultrahigh contrast and large-bandwidth thermal rectification in near-field electromagnetic thermal transfer between nanoparticles

    NASA Astrophysics Data System (ADS)

    Zhu, Linxiao; Otey, Clayton R.; Fan, Shanhui

    2014-09-01

    We exploit the unique properties of electromagnetic waves in nanophotonic structures to enhance the capabilities for active control of electromagnetic thermal transfer at nanoscale. We show that the near-field thermal transfer between two nanospheres can exhibit thermal rectification effect with very high contrast, and with large operating bandwidth. In this system, the scale invariance properties of the resonance modes result in a large difference in the coupling constants between relevant modes in the forward and reverse scenarios. Such a difference in coupling constants provides a new mechanism for thermal rectification.

  18. Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb^-1 of sqrt(s) = 7 TeV proton-proton collisions

    SciTech Connect

    Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdelalim, Ahmed Ali; Abdinov, Ovsat; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; /SUNY, Albany /Alberta U. /Ankara U. /Dumlupinar U. /Gazi U. /TOBB ETU, Ankara /TAEK, Ankara /Annecy, LAPP /Argonne /Arizona U. /Texas U., Arlington

    2012-06-01

    Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb{sup -1} of pp collision data at {radical}s = 7 TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from {ge}6 to {ge}9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m{sub 0}, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV.

  19. Antibacterial activity of large-area monolayer graphene film manipulated by charge transfer

    PubMed Central

    Li, Jinhua; Wang, Gang; Zhu, Hongqin; Zhang, Miao; Zheng, Xiaohu; Di, Zengfeng; Liu, Xuanyong; Wang, Xi

    2014-01-01

    Graphene has attracted increasing attention for potential applications in biotechnology due to its excellent electronic property and biocompatibility. Here we use both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) to investigate the antibacterial actions of large-area monolayer graphene film on conductor Cu, semiconductor Ge and insulator SiO2. The results show that the graphene films on Cu and Ge can surprisingly inhibit the growth of both bacteria, especially the former. However, the proliferation of both bacteria cannot be significantly restricted by the graphene film on SiO2. The morphology of S. aureus and E. coli on graphene films further confirms that the direct contact of both bacteria with graphene on Cu and Ge can cause membrane damage and destroy membrane integrity, while no evident membrane destruction is induced by graphene on SiO2. From the viewpoint of charge transfer, a plausible mechanism is proposed here to explain this phenomenon. This study may provide new insights for the better understanding of antibacterial actions of graphene film and for the better designing of graphene-based antibiotics or other biomedical applications. PMID:24619247

  20. Antibacterial activity of large-area monolayer graphene film manipulated by charge transfer

    NASA Astrophysics Data System (ADS)

    Li, Jinhua; Wang, Gang; Zhu, Hongqin; Zhang, Miao; Zheng, Xiaohu; di, Zengfeng; Liu, Xuanyong; Wang, Xi

    2014-03-01

    Graphene has attracted increasing attention for potential applications in biotechnology due to its excellent electronic property and biocompatibility. Here we use both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) to investigate the antibacterial actions of large-area monolayer graphene film on conductor Cu, semiconductor Ge and insulator SiO2. The results show that the graphene films on Cu and Ge can surprisingly inhibit the growth of both bacteria, especially the former. However, the proliferation of both bacteria cannot be significantly restricted by the graphene film on SiO2. The morphology of S. aureus and E. coli on graphene films further confirms that the direct contact of both bacteria with graphene on Cu and Ge can cause membrane damage and destroy membrane integrity, while no evident membrane destruction is induced by graphene on SiO2. From the viewpoint of charge transfer, a plausible mechanism is proposed here to explain this phenomenon. This study may provide new insights for the better understanding of antibacterial actions of graphene film and for the better designing of graphene-based antibiotics or other biomedical applications.

  1. Large eddy simulation for predicting turbulent heat transfer in gas turbines.

    PubMed

    Tafti, Danesh K; He, Long; Nagendra, K

    2014-08-13

    Blade cooling technology will play a critical role in the next generation of propulsion and power generation gas turbines. Accurate prediction of blade metal temperature can avoid the use of excessive compressed bypass air and allow higher turbine inlet temperature, increasing fuel efficiency and decreasing emissions. Large eddy simulation (LES) has been established to predict heat transfer coefficients with good accuracy under various non-canonical flows, but is still limited to relatively simple geometries and low Reynolds numbers. It is envisioned that the projected increase in computational power combined with a drop in price-to-performance ratio will make system-level simulations using LES in complex blade geometries at engine conditions accessible to the design process in the coming one to two decades. In making this possible, two key challenges are addressed in this paper: working with complex intricate blade geometries and simulating high-Reynolds-number (Re) flows. It is proposed to use the immersed boundary method (IBM) combined with LES wall functions. A ribbed duct at Re=20?000 is simulated using the IBM, and a two-pass ribbed duct is simulated at Re=100?000 with and without rotation (rotation number Ro=0.2) using LES with wall functions. The results validate that the IBM is a viable alternative to body-conforming grids and that LES with wall functions reproduces experimental results at a much lower computational cost. PMID:25024418

  2. Analysis of several hazardous conditions for large transfer and back-dilution sequences in Tank 241-SY-101

    SciTech Connect

    CW Stewart; LA Mahoney; WB Barton

    2000-01-28

    The first transfer of 89 kgal of waste and back-dilution of 61 kgal of water in Hanford Tank 241-SY-101 was accomplished December 18--20, 1999. Limits were placed on the transfer and back-dilution volumes because of concerns about potential gas release, crust sinking, and degradation of mixer pump performance. Additional transfers and back-dilutions are being planned that will bring the total to 500 kgal, which should dissolve a large fraction of the solids in the tank and dilute it well beyond the point where significant gas retention can occur. This report provides the technical bases for removing the limits on transfer and back-dilution volume by evaluating the potential consequences of several postulated hazardous conditions in view of the results of the first campaign and results of additional analyses of waste behavior.

  3. On laplace integrals and transfer operators in large dimension: Examples in the nonconvex case

    Microsoft Academic Search

    Bernard Helffer

    1996-01-01

    This Letter gives detailed proofs concerning the analysis of the pair correlations for a nonconvex model. Using the transfer matrix approach, the problem is reduced to the analysis of the spectral properties of this transfer operator. Although the problem is similar to the semiclassical study of the Kac operator presented in a paper with M. Brunaud, which was devoted?? to

  4. Momentum and Reversals in Industry Portfolio Returns

    Microsoft Academic Search

    Ding Du

    Contrary to Lehmann (1990) and Jegadeesh (1990), Gutierrez and Kelley (2008) recently find a long-lasting momentum in weekly individual stock returns. We extend Gutierrez and Kelley (2008) and examine momentum in weekly industry portfolio returns. We find that where momentum in six-month returns is mainly explained by cross-serial correlations as in Lewellen (2002), momentum in weekly returns is largely due

  5. High transverse momentum triggered correlations over a large pseudorapidity acceptance in Au+Au collisions at sqrt(s_NN)=200 GeV

    E-print Network

    Alver, Burak Han

    A measurement of two-particle correlations with a high transverse momentum trigger particle (p[subscript T][superscript trig]>2.5??GeV/c) is presented for Au+Au collisions at ?sNN=200 ??GeV over the uniquely broad ...

  6. Large-scale identification of endogenous secretory peptides using electron transfer dissociation mass spectrometry.

    PubMed

    Sasaki, Kazuki; Osaki, Tsukasa; Minamino, Naoto

    2013-03-01

    Mass spectrometry-based unbiased analysis of the full complement of secretory peptides is expected to facilitate the identification of unknown biologically active peptides. However, tandem MS sequencing of endogenous peptides in their native form has proven difficult because they show size heterogeneity and contain multiple internal basic residues, the characteristics not found in peptide fragments produced by in vitro digestion. Endogenous peptides remain largely unexplored by electron transfer dissociation (ETD), despite its widespread use in bottom-up proteomics. We used ETD, in comparison to collision induced dissociation (CID), to identify endogenous peptides derived from secretory granules of a human endocrine cell line. For mass accuracy, both MS and tandem MS were analyzed on an Orbitrap. CID and ETD, performed in different LC-MS runs, resulted in the identification of 795 and 569 unique peptides (ranging from 1000 to 15000 Da), respectively, with an overlap of 397. Peptides larger than 3000 Da accounted for 54% in CID and 46% in ETD identifications. Although numerically outperformed by CID, ETD provided more extensive fragmentation, leading to the identification of peptides that are not reached by CID. This advantage was demonstrated in identifying a new antimicrobial peptide from neurosecretory protein VGF (non-acronymic), VGF[554-577]-NH2, or in differentiating nearly isobaric peptides (mass difference less than 2 ppm) that arise from alternatively spliced exons of the gastrin-releasing peptide gene. CID and ETD complemented each other to add to our knowledge of the proteolytic processing sites of proteins implicated in the regulated secretory pathway. An advantage of the use of both fragmentation methods was also noted in localization of phosphorylation sites. These findings point to the utility of ETD mass spectrometry in the global study of endogenous peptides, or peptidomics. PMID:23250050

  7. Large-eddy simulation of fluid flow and heat transfer in a mixing tee junction

    NASA Astrophysics Data System (ADS)

    Lu, Tao; Wang, Yongwei; Wang, Kuisheng

    2012-11-01

    The temperature fluctuation caused by thermal striping phenomena of hot and cold fluids mixing results in cyclical thermal stress fatigue failure of the pipe wall. Mean temperature difference between hot and cold fluids was often used as thermal load in previous analysis of thermal fatigue failure, thereby the influences of the amplitude and frequency of temperature fluctuation on thermal fatigue failure were neglected. Based on the mechanism of flow and heat transfer which induces thermal fatigue, the turbulent mixing of hot and cold water in a tee junction is simulated with FLUENT platform by using the Large-eddy simulation(LES) turbulent flow model with the sub-grid scale(SGS) model of Smagorinsky-Lilly(SL) to capture the amplitude and frequency of temperature fluctuation. In a simulation case, hot water with temperature of 343.48 K and velocity of 0.15 m/s enters the horizontal main duct with the side length of 100 mm, while cold water with temperature of 296.78 K and velocity of 0.3 m/s enters the vertical branch duct with the side length of 50 mm. The numerical results show that the mean and fluctuating temperatures are in good agreement with the previous experimental data, which describes numerical simulation with high reliability and accuracy; the power spectrum density(PSD) on top wall is higher than that on bottom wall(as the frequency less than 1 Hz), while the PSD on bottom wall is relatively higher than that on top wall (as the frequency of 1-10Hz). The temperature fluctuations in full mixing region of the tee junction can be accurately captured by LES and can provide the theoretical basis for the thermal stress and thermal fatigue analyses.

  8. Large-scale Identification of Endogenous Secretory Peptides Using Electron Transfer Dissociation Mass Spectrometry*

    PubMed Central

    Sasaki, Kazuki; Osaki, Tsukasa; Minamino, Naoto

    2013-01-01

    Mass spectrometry-based unbiased analysis of the full complement of secretory peptides is expected to facilitate the identification of unknown biologically active peptides. However, tandem MS sequencing of endogenous peptides in their native form has proven difficult because they show size heterogeneity and contain multiple internal basic residues, the characteristics not found in peptide fragments produced by in vitro digestion. Endogenous peptides remain largely unexplored by electron transfer dissociation (ETD), despite its widespread use in bottom-up proteomics. We used ETD, in comparison to collision induced dissociation (CID), to identify endogenous peptides derived from secretory granules of a human endocrine cell line. For mass accuracy, both MS and tandem MS were analyzed on an Orbitrap. CID and ETD, performed in different LC-MS runs, resulted in the identification of 795 and 569 unique peptides (ranging from 1000 to 15000 Da), respectively, with an overlap of 397. Peptides larger than 3000 Da accounted for 54% in CID and 46% in ETD identifications. Although numerically outperformed by CID, ETD provided more extensive fragmentation, leading to the identification of peptides that are not reached by CID. This advantage was demonstrated in identifying a new antimicrobial peptide from neurosecretory protein VGF (non-acronymic), VGF[554–577]-NH2, or in differentiating nearly isobaric peptides (mass difference less than 2 ppm) that arise from alternatively spliced exons of the gastrin-releasing peptide gene. CID and ETD complemented each other to add to our knowledge of the proteolytic processing sites of proteins implicated in the regulated secretory pathway. An advantage of the use of both fragmentation methods was also noted in localization of phosphorylation sites. These findings point to the utility of ETD mass spectrometry in the global study of endogenous peptides, or peptidomics. PMID:23250050

  9. Search for a Direct Large-Cluster-Transfer Process in the C-12,c-13(ne-20,a) Reaction

    E-print Network

    Murakami, T.; Takahashi, N.; Lui, YW; Takada, E.; Tanner, D. M.; Tribble, Robert E.; Ungricht, E.; Nagatani, K.

    1985-01-01

    PHYSICAL REVIEW C VOLUME 32, NUMBER 6 DECEMBER 1985 Search for a direct large-cluster-transfer process in the ' C( Ne, a) reaction T. Murakami, ' N. Takahashi, Y.-W. Lui, E. Takada, ' D. M. Tanner, ~ R. E. Tribble, E. Ungricht, "' and K. Nagatani... Cyclotron Institute, Texas 3 4 M University, College Station, Texas 77843 (Received 7 August 1985) The C(20Ne, o.) reactions were measured at E= 140.2 MeV in order to search for a direct ' 0- cluster-transfer process. In the reaction with the C target...

  10. Measurement of the RLT, RL, and RT response functions for the 4He(e,e'p)3H reaction at large missing momentum

    Microsoft Academic Search

    M. B. Epstein; K. A. Aniol; D. J. Margaziotis; B. Jiang; H. Baghaei; W. Bertozzi; W. Boeglin; L. Weinstein; S. Penn; J. Morrison; R. W. Lourie; J. M. Finn; C. F. Perdrisat; V. Punjabi; P. E. Ulmer; C. C. Chang; P. Boberg; John Calarco; J. M. Laget

    1993-01-01

    The 4He(e,e'p)3H reaction has been measured at a missing momentum of 265 MeV\\/c. Data were taken to determine the RL, RT, and RLT response functions. The extracted response functions show substantial differences from a microscopic calculation that includes the plane wave impulse approximation, final state interactions, and meson exchange currents, but agree much better with a calculation that includes orthogonality

  11. Suppression of Charged Particle Production at Large Transverse Momentum in Central Pb--Pb Collisions at $\\\\sqrt{s_{NN}}$ = 2.76 TeV

    Microsoft Academic Search

    Kenneth Aamodt; Arian Abrahantes Quintana; Dagmar Adamova; Andrew Marshall Adare; Madan Aggarwal; Gianluca Aglieri Rinella; Andras Gabor Agocs; Saul Aguilar Salazar; Zubayer Ahammed; Arshad Ahmad; Nazeer Ahmad; Sang Un Ahn; Alexander Akindinov; Dmitry Aleksandrov; Bruno Alessandro; Jose Ruben Alfaro Molina; Andrea Alici; Anton Alkin; Erick Jonathan Almaraz Avina; Torsten Alt; Valerio Altini; Sedat Altinpinar; Igor Altsybeev; Cristian Andrei; Anton Andronic; Venelin Anguelov; Christopher Daniel Anson; Tome Anticic; Federico Antinori; Pietro Antonioli; Laurent Bernard Aphecetche; Harald Appelshauser; Nicolas Arbor; Silvia Arcelli; Andreas Arend; Nestor Armesto; Roberta Arnaldi; Tomas Robert Aronsson; Ionut Cristian Arsene; Andzhey Asryan; Andre Augustinus; Ralf Peter Averbeck; Terry Awes; Juha Heikki Aysto; Mohd Danish Azmi; Matthias Jakob Bach; Angela Badala; Yong Wook Baek; Raphaelle Marie Bailhache; Renu Bala; Rinaldo Baldini Ferroli; Alberto Baldisseri; Alain Baldit; Jaroslav Ban; Roberto Barbera; Francesco Barile; Gergely Gabor Barnafoldi; Lee Stuart Barnby; Valerie Barret; Jerzy Gustaw Bartke; Maurizio Basile; Nicole Bastid; Bastian Bathen; Guillaume Batigne; Boris Batyunya; Christoph Heinrich Baumann; Ian Gardner Bearden; Hans Beck; Iouri Belikov; Francesca Bellini; Rene Bellwied; Ernesto Belmont-Moreno; Stefania Beole; Ionela Berceanu; Alexandru Bercuci; Eleni Berdermann; Yaroslav Berdnikov; Latchezar Betev; Anju Bhasin; Ashok Kumar Bhati; Livio Bianchi; Nicola Bianchi; Chiara Bianchin; Jaroslav Bielcik; Jana Bielcikova; Ante Bilandzic; Emanuele Biolcati; Aurelien Joseph Blanc; F Blanco; Dmitry Blau; Christoph Blume; Marco Boccioli; Nicolas Bock; Alexey Bogdanov; Hans Boggild; Mikhail Bogolyubsky; Laszlo Boldizsar; Marek Bombara; Carlo Bombonati; Herve Borel; Claudio Bortolin; Suvendu Nath Bose; Francesco Bossu; Michiel Botje; Stefan Bottger; Bruno Alexandre Boyer; Peter Braun-Munzinger; Larisa Bravina; Marco Bregant; Timo Gunther Breitner; Michal Broz; Rene Brun; Elena Bruna; Giuseppe Eugenio Bruno; Dmitry Budnikov; Henner Buesching; Oliver Busch; Edith Zinhle Buthelezi; Davide Caffarri; Xu Cai; Helen Louise Caines; Ernesto Calvo Villar; Paolo Camerini; Veronica Canoa Roman; Giovanni Cara Romeo; Francesco Carena; Wisla Carena; Federico Carminati; Amaya Ofelia Casanova Diaz; Michele Caselle; Javier Ernesto Castillo Castellanos; Vasile Catanescu; Costanza Cavicchioli; Piergiorgio Cerello; Beomsu Chang; Sylvain Chapeland; Jean-Luc Fernand Charvet; Sukalyan Chattopadhyay; Subhasis Chattopadhyay; Michael Gerard Cherney; Cvetan Cheshkov; Brigitte Cheynis; Emilio Chiavassa; Vasco Miguel Chibante Barroso; David Chinellato; Peter Chochula; Marek Chojnacki; Panagiotis Christakoglou; Christian Holm Christensen; Peter Christiansen; Tatsuya Chujo; Corrado Cicalo; Luisa Cifarelli; Federico Cindolo; Jean Willy Andre Cleymans; Fabrizio Coccetti; Jean-Pierre Michel Coffin; Gustavo Conesa Balbastre; Zaida Conesa del Valle; Paul Constantin; Giacomo Contin; Jesus Guillermo Contreras; Thomas Michael Cormier; Yasser Corrales Morales; Ismael Cortes Maldonado; Pietro Cortese; Mauro Rogerio Cosentino; Filippo Costa; Manuel Enrique Cotallo; Elisabetta Crescio; Philippe Crochet; Eleazar Cuautle; Leticia Cunqueiro; Ginevra D'Erasmo; Andrea Dainese; Hans Hjersing Dalsgaard; Andrea Danu; Debasish Das; Indranil Das; Ajay Kumar Dash; Sadhana Dash; Sudipan De; Andrea De Azevedo Moregula; Gabriel de Barros; Annalisa De Caro; Giacinto de Cataldo; Jan de Cuveland; Alessandro De Falco; Daniele De Gruttola; Nora De Marco; Salvatore De Pasquale; Raoul Stefan de Rooij; Hugues Delagrange; Ydalia Delgado Mercado; Giuseppe Dellacasa; Andrzej Deloff; Vyacheslav Demanov; Ervin Denes; Airton Deppman; Domenico Di Bari; Carmelo Di Giglio; Sergio Di Liberto; Antonio Di Mauro; Pasquale Di Nezza; Thomas Dietel; Roberto Divia; Oeystein Djuvsland; Alexandru Florin Dobrin; Tadeusz Antoni Dobrowolski; Isabel Dominguez; Benjamin Donigus; Olja Dordic; Olha Dryha; Anand Kumar Dubey; Jimmy Dubuisson; Laurent Ducroux; Pascal Dupieux; AK Dutta Majumdar; Mihir Ranjan Dutta Majumdar; Domenico Elia; David Philip Emschermann; Heiko Engel; Hege Austrheim Erdal; Bruno Espagnon; Magali Danielle Estienne; Shinichi Esumi; David Evans; Sebastien Evrard; Gyulnara Eyyubova; Christian Fabjan; Daniela Fabris; Julien Faivre; Davide Falchieri; Alessandra Fantoni; Markus Fasel; Roger Worsley Fearick; Anatoly Fedunov; Dominik Fehlker; Vladimir Fekete; Daniel Felea; Grigory Feofilov; Arturo Fernandez Tellez; Alessandro Ferretti; Roberta Ferretti; Marcel Figueredo

    2010-01-01

    Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at $\\\\sqrt{s_{NN}}$ = 2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross section. The measured charged particle spectra in $|\\\\eta|<0.8$ and $0.3 < p_T < 20$ GeV\\/$c$

  12. Suppression of Hadrons with Large Transverse Momentum in Central Au+Au Collisions at (sNN) = 130 GeV

    Microsoft Academic Search

    K. Adcox; S. S. Adler; N. N. Ajitanand; Y. Akiba; J. Alexander; L. Aphecetche; Y. Arai; S. H. Aronson; R. Averbeck; T. C. Awes; K. N. Barish; P. D. Barnes; J. Barrette; B. Bassalleck; S. Bathe; V. Baublis; A. Bazilevsky; S. Belikov; F. G. Bellaiche; S. T. Belyaev; M. J. Bennett; Y. Berdnikov; S. Botelho; M. L. Brooks; D. S. Brown; N. Bruner; D. Bucher; H. Buesching; V. Bumazhnov; G. Bunce; J. Burward-Hoy; S. Butsyk; T. A. Carey; P. Chand; J. Chang; W. C. Chang; L. L. Chavez; S. Chernichenko; C. Y. Chi; J. Chiba; M. Chiu; R. K. Choudhury; T. Christ; T. Chujo; M. S. Chung; P. Chung; V. Cianciolo; B. A. Cole; D. G. D'Enterria; G. David; H. Delagrange; A. Denisov; A. Deshpande; E. J. Desmond; O. Dietzsch; B. V. Dinesh; A. Drees; A. Durum; D. Dutta; K. Ebisu; Y. V. Efremenko; K. El Chenawi; H. En'yo; S. Esumi; L. Ewell; T. Ferdousi; D. E. Fields; S. L. Fokin; Z. Fraenkel; A. Franz; A. D. Frawley; S.-Y. Fung; S. Garpman; T. K. Ghosh; A. Glenn; A. L. Godoi; Y. Goto; S. V. Greene; M. Grosse Perdekamp; S. K. Gupta; W. Guryn; H.-Å. Gustafsson; J. S. Haggerty; H. Hamagaki; A. G. Hansen; H. Hara; E. P. Hartouni; R. Hayano; N. Hayashi; X. He; T. K. Hemmick; J. M. Heuser; M. Hibino; J. C. Hill; D. S. Ho; K. Homma; B. Hong; A. Hoover; T. Ichihara; K. Imai; M. S. Ippolitov; M. Ishihara; B. V. Jacak; W. Y. Jang; J. Jia; B. M. Johnson; S. C. Johnson; K. S. Joo; S. Kametani; J. H. Kang; M. Kann; S. S. Kapoor; S. Kelly; B. Khachaturov; A. Khanzadeev; J. Kikuchi; D. J. Kim; H. J. Kim; S. Y. Kim; Y. G. Kim; W. W. Kinnison; E. Kistenev; A. Kiyomichi; C. Klein-Boesing; S. Klinksiek; L. Kochenda; V. Kochetkov; D. Koehler; T. Kohama; D. Kotchetkov; A. Kozlov; P. J. Kroon; K. Kurita; M. J. Kweon; Y. Kwon; G. S. Kyle; R. Lacey; J. G. Lajoie; J. Lauret; A. Lebedev; D. M. Lee; M. J. Leitch; X. H. Li; Z. Li; D. J. Lim; M. X. Liu; X. Liu; Z. Liu; C. F. Maguire; J. Mahon; Y. I. Makdisi; V. I. Manko; Y. Mao; S. K. Mark; S. Markacs; G. Martinez; M. D. Marx; A. Masaike; F. Matathias; T. Matsumoto; P. L. McGaughey; E. Melnikov; M. Merschmeyer; F. Messer; M. Messer; Y. Miake; T. E. Miller; A. Milov; S. Mioduszewski; R. E. Mischke; G. C. Mishra; J. T. Mitchell; A. K. Mohanty; J. M. Moss; F. Mühlbacher; M. Muniruzzaman; J. Murata; S. Nagamiya; Y. Nagasaka; J. L. Nagle; Y. Nakada; B. K. Nandi; J. Newby; L. Nikkinen; P. Nilsson; S. Nishimura; A. S. Nyanin; J. Nystrand; E. O'Brien; C. A. Ogilvie; H. Ohnishi; I. D. Ojha; M. Ono; V. Onuchin; A. Oskarsson; L. Österman; I. Otterlund; K. Oyama; L. Paffrath; A. P. Palounek; V. S. Pantuev; V. Papavassiliou; S. F. Pate; T. Peitzmann; A. N. Petridis; C. Pinkenburg; R. P. Pisani; P. Pitukhin; F. Plasil; M. Pollack; K. Pope; M. L. Purschke; I. Ravinovich; K. F. Read; K. Reygers; V. Riabov; Y. Riabov; M. Rosati; A. A. Rose; S. S. Ryu; N. Saito; A. Sakaguchi; T. Sakaguchi; H. Sako; T. Sakuma; V. Samsonov; T. C. Sangster; R. Santo; H. D. Sato; S. Sato; S. Sawada; B. R. Schlei; Y. Schutz; V. Semenov; R. Seto; T. K. Shea; I. Shein; T.-A. Shibata; K. Shigaki; T. Shiina; Y. H. Shin; I. G. Sibiriak; D. Silvermyr; K. S. Sim; J. Simon-Gillo; C. P. Singh; V. Singh; M. Sivertz; A. Soldatov; R. A. Soltz; S. Sorensen; P. W. Stankus; N. Starinsky; P. Steinberg; E. Stenlund; A. Ster; S. P. Stoll; M. Sugioka; T. Sugitate; J. P. Sullivan; Y. Sumi; Z. Sun; M. Suzuki; E. M. Takagui; A. Taketani; M. Tamai; K. H. Tanaka; Y. Tanaka; E. Taniguchi; M. J. Tannenbaum; J. Thomas; T. L. Thomas; W. Tian; J. Tojo; H. Torii; R. S. Towell; I. Tserruya; H. Tsuruoka; A. A. Tsvetkov; S. K. Tuli; H. Tydesjö; N. Tyurin; T. Ushiroda; H. W. van Hecke; C. Velissaris; J. Velkovska; M. Velkovsky; A. A. Vinogradov; M. A. Volkov; A. Vorobyov; E. Vznuzdaev; H. Wang; Y. Watanabe; S. N. White; C. Witzig; F. K. Wohn; C. L. Woody; W. Xie; K. Yagi; S. Yokkaichi; G. R. Young; I. E. Yushmanov; W. A. Zajc; Z. Zhang; S. Zhou

    2002-01-01

    Transverse momentum spectra for charged hadrons and for neutral pions in the range 1 GeV\\/c

  13. Search for Dark Matter Candidates and Large Extra Dimensions in Events with a Photon and Missing Transverse Momentum in pp Collision Data at ?s=7?TeV with the ATLAS Detector

    DOE PAGESBeta

    Aad, G.; Abajyan, T.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdelalim, A. A.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Adomeit, S.; Adragna, P.; Adye, T.; Aefsky, S.; Aguilar-Saavedra, J. A.; Agustoni, M.; Aharrouche, M.; Ahlen, S. P.; Ahles, F.; Ahmad, A.; Ahsan, M.; Aielli, G.; Akdogan, T.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alam, M. S.; Alam, M. A.; Albert, J.; Albrand, S.; Aleksa, M.; Aleksandrov, I. N.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alison, J.; Allbrooke, B. M. M.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alonso, F.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amelung, C.; Ammosov, V. V.; Amor Dos Santos, S. P.; Amorim, A.; Amram, N.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Andrieux, M-L.; Anduaga, X. S.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aoun, S.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Arfaoui, S.; Arguin, J-F.; Arik, E.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arnault, C.; Artamonov, A.; Artoni, G.; Arutinov, D.; Asai, S.; Asfandiyarov, R.; Ask, S.; Åsman, B.; Asquith, L.; Assamagan, K.; Astbury, A.; Atkinson, M.; Aubert, B.; Auge, E.; Augsten, K.; Aurousseau, M.; Avolio, G.; Avramidou, R.; Axen, D.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Baccaglioni, G.; Bacci, C.; Bach, A. M.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Badescu, E.; Bagnaia, P.; Bahinipati, S.; Bai, Y.; Bailey, D. C.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, M. D.; Baker, S.; Banas, E.; Banerjee, P.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barbaro Galtieri, A.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Bardin, D. Y.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Barrillon, P.; Bartoldus, R.; Barton, A. E.; Bartsch, V.; Basye, A.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battaglia, A.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beale, S.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, A. K.; Becker, S.; Beckingham, M.; Becks, K. H.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Begel, M.; Behar Harpaz, S.; Behera, P. K.; Beimforde, M.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellina, F.; Bellomo, M.; Belloni, A.; Beloborodova, O.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Benoit, M.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernat, P.; Bernhard, R.; Bernius, C.; Berry, T.; Bertella, C.; Bertin, A.; Bertolucci, F.; Besana, M. I.; Besjes, G. J.; Besson, N.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Biscarat, C.; Bittner, B.; Black, K. M.; Blair, R. E.; Blanchard, J.-B.; Blanchot, G.; Blazek, T.; Bloch, I.; Blocker, C.; Blocki, J.; Blondel, A.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. B.; Bocchetta, S. S.; Bocci, A.; Boddy, C. R.; Boehler, M.; Boek, J.; Boelaert, N.; Bogaerts, J. A.; Bogdanchikov, A.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Bolnet, N. M.; Bomben, M.; Bona, M.; Boonekamp, M.; Bordoni, S.; Borer, C.; Borisov, A.; Borissov, G.; Borjanovic, I.; Borri, M.; Borroni, S.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Bouchami, J.; Boudreau, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozovic-Jelisavcic, I.; Bracinik, J.; Branchini, P.; Brandenburg, G. W.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Bremer, J.; Brendlinger, K.; Brenner, R.; Bressler, S.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Broggi, F.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brown, G.; Brown, H.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.

    2013-01-01

    Results of a search for new phenomena in events with an energetic photon and large missing transverse momentum in proton-proton collisions at ?s =7??TeV are reported. Data collected by the ATLAS experiment at the LHC corresponding to an integrated luminosity of 4.6??fb?1 are used. Good agreement is observed between the data and the standard model predictions. The results are translated into exclusion limits on models with large extra spatial dimensions and on pair production of weakly interacting dark matter candidates.

  14. Search for dark matter candidates and large extra dimensions in events with a photon and missing transverse momentum in pp collision data at sqrt(s) = 7 TeV with the ATLAS detector

    E-print Network

    ATLAS Collaboration

    2012-09-29

    Results of a search for new phenomena in events with an energetic photon and large missing transverse momentum in proton-proton collisions at sqrt(s)=7 TeV are reported. Data collected by the ATLAS experiment at the LHC corresponding to an integrated luminosity of 4.6 fb-1 are used. Good agreement is observed between the data and the Standard Model predictions. The results are translated into exclusion limits on models with large extra spatial dimensions and on pair production of weakly interacting dark matter candidates.

  15. Search for dark matter candidates and large extra dimensions in events with a photon and missing transverse momentum in pp collision data at sqrt[s]=7 TeV with the ATLAS detector.

    PubMed

    Aad, G; Abajyan, T; Abbott, B; Abdallah, J; Abdel Khalek, S; Abdelalim, A A; Abdinov, O; Aben, R; Abi, B; Abolins, M; Abouzeid, O S; Abramowicz, H; Abreu, H; Acharya, B S; Adamczyk, L; Adams, D L; Addy, T N; Adelman, J; Adomeit, S; Adragna, P; Adye, T; Aefsky, S; Aguilar-Saavedra, J A; Agustoni, M; Aharrouche, M; Ahlen, S P; Ahles, F; Ahmad, A; Ahsan, M; Aielli, G; Akdogan, T; Akesson, T P A; Akimoto, G; Akimov, A V; Alam, M S; Alam, M A; Albert, J; Albrand, S; Aleksa, M; Aleksandrov, I N; Alessandria, F; Alexa, C; Alexander, G; Alexandre, G; Alexopoulos, T; Alhroob, M; Aliev, M; Alimonti, G; Alison, J; Allbrooke, B M M; Allport, P P; Allwood-Spiers, S E; Almond, J; Aloisio, A; Alon, R; Alonso, A; Alonso, F; Altheimer, A; Alvarez Gonzalez, B; Alviggi, M G; Amako, K; Amelung, C; Ammosov, V V; Amor Dos Santos, S P; Amorim, A; Amram, N; Anastopoulos, C; Ancu, L S; Andari, N; Andeen, T; Anders, C F; Anders, G; Anderson, K J; Andreazza, A; Andrei, V; Andrieux, M-L; Anduaga, X S; Anger, P; Angerami, A; Anghinolfi, F; Anisenkov, A; Anjos, N; Annovi, A; Antonaki, A; Antonelli, M; Antonov, A; Antos, J; Anulli, F; Aoki, M; Aoun, S; Aperio Bella, L; Apolle, R; Arabidze, G; Aracena, I; Arai, Y; Arce, A T H; Arfaoui, S; Arguin, J-F; Arik, E; Arik, M; Armbruster, A J; Arnaez, O; Arnal, V; Arnault, C; Artamonov, A; Artoni, G; Arutinov, D; Asai, S; Asfandiyarov, R; Ask, S; Asman, B; Asquith, L; Assamagan, K; Astbury, A; Atkinson, M; Aubert, B; Auge, E; Augsten, K; Aurousseau, M; Avolio, G; Avramidou, R; Axen, D; Azuelos, G; Azuma, Y; Baak, M A; Baccaglioni, G; Bacci, C; Bach, A M; Bachacou, H; Bachas, K; Backes, M; Backhaus, M; Badescu, E; Bagnaia, P; Bahinipati, S; Bai, Y; Bailey, D C; Bain, T; Baines, J T; Baker, O K; Baker, M D; Baker, S; Banas, E; Banerjee, P; Banerjee, Sw; Banfi, D; Bangert, A; Bansal, V; Bansil, H S; Barak, L; Baranov, S P; Barbaro Galtieri, A; Barber, T; Barberio, E L; Barberis, D; Barbero, M; Bardin, D Y; Barillari, T; Barisonzi, M; Barklow, T; Barlow, N; Barnett, B M; Barnett, R M; Baroncelli, A; Barone, G; Barr, A J; Barreiro, F; Barreiro Guimarães da Costa, J; Barrillon, P; Bartoldus, R; Barton, A E; Bartsch, V; Basye, A; Bates, R L; Batkova, L; Batley, J R; Battaglia, A; Battistin, M; Bauer, F; Bawa, H S; Beale, S; Beau, T; Beauchemin, P H; Beccherle, R; Bechtle, P; Beck, H P; Becker, A K; Becker, S; Beckingham, M; Becks, K H; Beddall, A J; Beddall, A; Bedikian, S; Bednyakov, V A; Bee, C P; Beemster, L J; Begel, M; Behar Harpaz, S; Behera, P K; Beimforde, M; Belanger-Champagne, C; Bell, P J; Bell, W H; Bella, G; Bellagamba, L; Bellina, F; Bellomo, M; Belloni, A; Beloborodova, O; Belotskiy, K; Beltramello, O; Benary, O; Benchekroun, D; Bendtz, K; Benekos, N; Benhammou, Y; Benhar Noccioli, E; Benitez Garcia, J A; Benjamin, D P; Benoit, M; Bensinger, J R; Benslama, K; Bentvelsen, S; Berge, D; Bergeaas Kuutmann, E; Berger, N; Berghaus, F; Berglund, E; Beringer, J; Bernat, P; Bernhard, R; Bernius, C; Berry, T; Bertella, C; Bertin, A; Bertolucci, F; Besana, M I; Besjes, G J; Besson, N; Bethke, S; Bhimji, W; Bianchi, R M; Bianco, M; Biebel, O; Bieniek, S P; Bierwagen, K; Biesiada, J; Biglietti, M; Bilokon, H; Bindi, M; Binet, S; Bingul, A; Bini, C; Biscarat, C; Bittner, B; Black, K M; Blair, R E; Blanchard, J-B; Blanchot, G; Blazek, T; Bloch, I; Blocker, C; Blocki, J; Blondel, A; Blum, W; Blumenschein, U; Bobbink, G J; Bobrovnikov, V B; Bocchetta, S S; Bocci, A; Boddy, C R; Boehler, M; Boek, J; Boelaert, N; Bogaerts, J A; Bogdanchikov, A; Bogouch, A; Bohm, C; Bohm, J; Boisvert, V; Bold, T; Boldea, V; Bolnet, N M; Bomben, M; Bona, M; Boonekamp, M; Bordoni, S; Borer, C; Borisov, A; Borissov, G; Borjanovic, I; Borri, M; Borroni, S; Bortolotto, V; Bos, K; Boscherini, D; Bosman, M; Boterenbrood, H; Bouchami, J; Boudreau, J; Bouhova-Thacker, E V; Boumediene, D; Bourdarios, C; Bousson, N; Boveia, A; Boyd, J; Boyko, I R; Bozovic-Jelisavcic, I; Bracinik, J; Branchini, P; Brandenburg, G W; Brandt, A; Brandt, G; Brandt, O; Bratzler, U; Brau, B; Brau, J E; Braun, H M; Brazzale, S F; Brelier, B; Bremer, J; Brendlinger, K; Brenner, R; Bressler, S; Britton, D; Brochu, F M; Brock, I; Brock, R; Broggi, F; Bromberg, C; Bronner, J; Brooijmans, G; Brooks, T; Brooks, W K; Brown, G; Brown, H; Bruckman de Renstrom, P A; Bruncko, D; Bruneliere, R; Brunet, S; Bruni, A; Bruni, G; Bruschi, M; Buanes, T; Buat, Q; Bucci, F; Buchanan, J; Buchholz, P; Buckingham, R M; Buckley, A G; Buda, S I; Budagov, I A; Budick, B; Büscher, V; Bugge, L; Bulekov, O; Bundock, A C; Bunse, M; Buran, T; Burckhart, H; Burdin, S; Burgess, T; Burke, S; Busato, E; Bussey, P; Buszello, C P; Butler, B; Butler, J M; Buttar, C M; Butterworth, J M; Buttinger, W; Byszewski, M; Cabrera Urbán, S; Caforio, D; Cakir, O; Calafiura, P; Calderini, G; Calfayan, P; Calkins, R; Caloba, L P; Caloi, R; Calvet, D; Calvet, S

    2013-01-01

    Results of a search for new phenomena in events with an energetic photon and large missing transverse momentum in proton-proton collisions at sqrt[s] = 7 TeV are reported. Data collected by the ATLAS experiment at the LHC corresponding to an integrated luminosity of 4.6 fb(-1) are used. Good agreement is observed between the data and the standard model predictions. The results are translated into exclusion limits on models with large extra spatial dimensions and on pair production of weakly interacting dark matter candidates. PMID:23383779

  16. Conservation of Momentum 2

    NSDL National Science Digital Library

    Michael Horton

    2009-05-30

    This inquiry activity should be performed after students have learned about momentum, but before they learn about conservation of momentum. Students will discover that when two objects push off each other, the momentum must be equal but in opposite direct

  17. Facile electrochemical transfer of large-area single crystal epitaxial graphene from Ir(1?1?1)

    NASA Astrophysics Data System (ADS)

    Koefoed, Line; Kongsfelt, Mikkel; Ulstrup, Søren; Grubiši? ?abo, Antonija; Cassidy, Andrew; Whelan, Patrick R.; Bianchi, Marco; Dendzik, Maciej; Pizzocchero, Filippo; Jørgensen, Bjarke; Bøggild, Peter; Hornekær, Liv; Hofmann, Philip; Pedersen, Steen U.; Daasbjerg, Kim

    2015-03-01

    High-quality growth of graphene and subsequent reliable transfer to insulating substrates are needed for various technological applications, such as flexible screens and high speed electronics. In this paper, we present a new electrochemical method for the transfer of large-area, high-quality single crystalline graphene from Ir(1?1?1) to Si/SiO2 under ambient conditions. The method is based on intercalation of tetraoctylammonium ions between the graphene layer and the Ir surface. This simple technique allows transfer of graphene single crystals having the same size as the substrate they are grown on (diameter ?7?mm). In addition, the substrate can be reused for further growth cycles. A detailed Raman map analysis of the transferred graphene reveals straight lines, in which the Raman peaks characteristic for graphene are shifted. These lines originate from scratches in the Ir(1?1?1) crystal introduced by the polishing procedure. Furthermore, areas with numerous wrinkles exist inbetween these lines, forming a network across the entire graphene crystal. Hence, the initial characteristics and imprints left on the sheet of graphene in terms of strain and wrinkles from the growth process remain after transfer.

  18. Chaotic heat transfer for heat exchanger design and comparison with a regular regime for a large range of Reynolds numbers

    Microsoft Academic Search

    C Chagny; C Castelain; H Peerhossaini

    2000-01-01

    An experimental comparison is made over a large range of Reynolds numbers (from 30 to 30,000) between two shell-and-tube heat exchangers having the same heat-transfer area and same number of bends, but different configurations: one has a helical configuration (regular flow), the other has a chaotic one (chaotic advection flow). Both are composed of 33 bends with circular tube cross

  19. Multiple recent horizontal transfers of a large genomic region in cheese making fungi

    PubMed Central

    Cheeseman, Kevin; Ropars, Jeanne; Renault, Pierre; Dupont, Joëlle; Gouzy, Jérôme; Branca, Antoine; Abraham, Anne-Laure; Ceppi, Maurizio; Conseiller, Emmanuel; Debuchy, Robert; Malagnac, Fabienne; Goarin, Anne; Silar, Philippe; Lacoste, Sandrine; Sallet, Erika; Bensimon, Aaron; Giraud, Tatiana; Brygoo, Yves

    2014-01-01

    While the extent and impact of horizontal transfers in prokaryotes are widely acknowledged, their importance to the eukaryotic kingdom is unclear and thought by many to be anecdotal. Here we report multiple recent transfers of a huge genomic island between Penicillium spp. found in the food environment. Sequencing of the two leading filamentous fungi used in cheese making, P. roqueforti and P. camemberti, and comparison with the penicillin producer P. rubens reveals a 575?kb long genomic island in P. roqueforti—called Wallaby—present as identical fragments at non-homologous loci in P. camemberti and P. rubens. Wallaby is detected in Penicillium collections exclusively in strains from food environments. Wallaby encompasses about 250 predicted genes, some of which are probably involved in competition with microorganisms. The occurrence of multiple recent eukaryotic transfers in the food environment provides strong evidence for the importance of this understudied and probably underestimated phenomenon in eukaryotes. PMID:24407037

  20. Fast delocalization leads to robust long-range excitonic transfer in a large quantum chlorosome model.

    PubMed

    Sawaya, Nicolas P D; Huh, Joonsuk; Fujita, Takatoshi; Saikin, Semion K; Aspuru-Guzik, Alán

    2015-03-11

    Chlorosomes are efficient light-harvesting antennas containing up to hundreds of thousands of bacteriochlorophyll molecules. With massively parallel computer hardware, we use a nonperturbative stochastic Schrödinger equation, while including an atomistically derived spectral density, to study excitonic energy transfer in a realistically sized chlorosome model. We find that fast short-range delocalization leads to robust long-range transfer due to the antennae's concentric-roll structure. Additionally, we discover anomalous behavior arising from different initial conditions, and outline general considerations for simulating excitonic systems on the nanometer to micrometer scale. PMID:25694170

  1. Experimental Investigation of Free-Convection Heat Transfer in Vertical Tube at Large Grashof Numbers

    NASA Technical Reports Server (NTRS)

    Eckert, E R G; Diaguila, A J

    1955-01-01

    Report presents the results of an investigation conducted to study free-convection heat transfer in a stationary vertical tube closed at the bottom. The walls of the tube were heated, and heated air in the tube was continuously replaced by fresh cool air at the top. The tube was designed to provide a gravitational field with Grashof numbers of a magnitude comparable with those generated by the centrifugal field in rotating-blade coolant passages (10(8) to 10(13)). Local heat-transfer coefficients in the turbulent-flow range and the temperature field within the fluid were obtained.

  2. Heat transfer and convection in Czochralski growth of large BGO Crystals

    NASA Astrophysics Data System (ADS)

    Mazaev, K.; Kalaev, V.; Galenin, E.; Tkachenko, S.; Sidletskiy, O.

    2009-07-01

    In the present work, numerical modeling has been performed to analyze heat transfer and melt convection during bismuth germanate Bi 4Ge 3O 12 (BGO) crystal growth by the Czochralski growth method. In addition to global heat-transfer modeling, the suggested model accounts for the radiative heat exchange in the crystal and melt convection together with the crystallization front formation. The model helped to analyze the modification of the growth setup made by including additional heater. The numerical predictions obtained with CGSim software agree well with available experimental data.

  3. Studies of Forced-Convection Heat Transfer Augmentation in Large Containment Enclosures

    SciTech Connect

    Kuhn, S.Z.; Peterson, P.F.

    2001-06-17

    Heat transfer enhancement due to jet mixing inside a cylindrical enclosure is discussed. This work addresses conservative heat transfer assumptions regarding mixing and condensation that have typically been incorporated into passive containment design analyses. This research presents the possibility for increasing decay heat removal of passive containment systems under combined natural and forced convection. Eliminating these conservative assumptions could result in a changed containment design and reduce the construction cost. It is found that the ratio of forced- and free-convection Nusselt numbers can be predicted as a function of the Archimedes number and a correlated factor accounting for jet orientation and enclosure geometry.

  4. Momentum harvesting techniques for solar system travel

    NASA Technical Reports Server (NTRS)

    Willoughby, Alan J.

    1990-01-01

    Astronomers are lately estimating there are 400,000 Earth visiting asteroids larger than 100 meters in diameter. These asteroids are accessible sources of building materials, propellants, oxygen, water, and minerals which also constitute a huge momentum reserve, potentially usable for travel throughout the solar system. To use this momentum, these stealthy objects must be tracked and the extraction of the momentum wanted must be learned. Momentum harvesting by momentum transfer from asteroid to spacecraft, and by using the momentum of the extraterrestrial material to help deliver itself to the destination are discussed. A net and tether concept is the suggested means of asteroid capture, the basic momentum exchange process. The energy damping characteristics of the tether will determine the velocity mismatch that can be tolerated, and hence the amount of momentum that can be harvested per capture. As it plays out of its reel, drag on the tether steadily accelerates the spacecraft. A variety of concepts for riding and using the asteroid after capture are discussed. The hitchhiker uses momentum transfer only. The beachcomber, the caveman, the swinger, the prospector, and the rock wrecker also take advantage of raw asteroidal materials. The chemist and the hijacker go further, they process the asteroid into propellant. Or, an 'asteroid railway system' could evolve with each hijacked asteroid becoming a scheduled train. Travelers could board the space railway system assured that water, oxygen, and propellants await them.

  5. Transfer of learning relates to intrinsic connectivity between hippocampus, ventromedial prefrontal cortex, and large-scale networks.

    PubMed

    Gerraty, Raphael T; Davidow, Juliet Y; Wimmer, G Elliott; Kahn, Itamar; Shohamy, Daphna

    2014-08-20

    An important aspect of adaptive learning is the ability to flexibly use past experiences to guide new decisions. When facing a new decision, some people automatically leverage previously learned associations, while others do not. This variability in transfer of learning across individuals has been demonstrated repeatedly and has important implications for understanding adaptive behavior, yet the source of these individual differences remains poorly understood. In particular, it is unknown why such variability in transfer emerges even among homogeneous groups of young healthy participants who do not vary on other learning-related measures. Here we hypothesized that individual differences in the transfer of learning could be related to relatively stable differences in intrinsic brain connectivity, which could constrain how individuals learn. To test this, we obtained a behavioral measure of memory-based transfer outside of the scanner and on a separate day acquired resting-state functional MRI images in 42 participants. We then analyzed connectivity across independent component analysis-derived brain networks during rest, and tested whether intrinsic connectivity in learning-related networks was associated with transfer. We found that individual differences in transfer were related to intrinsic connectivity between the hippocampus and the ventromedial prefrontal cortex, and between these regions and large-scale functional brain networks. Together, the findings demonstrate a novel role for intrinsic brain dynamics in flexible learning-guided behavior, both within a set of functionally specific regions known to be important for learning, as well as between these regions and the default and frontoparietal networks, which are thought to serve more general cognitive functions. PMID:25143610

  6. Identified hadron spectra at large transverse momentum in p+p and d+Au collisions at s=200 GeV

    NASA Astrophysics Data System (ADS)

    STAR Collaboration; Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Anderson, M.; Arkhipkin, D.; Averichev, G. S.; Badyal, S. K.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Bekele, S.; Belaga, V. V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Bezverkhny, B. I.; Bharadwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Billmeier, A.; Bland, L. C.; Blyth, C. O.; Blyth, S.-L.; Bonner, B. E.; Botje, M.; Bouchet, J.; Brandin, A. V.; Bravar, A.; Bystersky, M.; Cadman, R. V.; Cai, X. Z.; Caines, H.; de La Barca Sánchez, M. Calderón; Castillo, J.; Catu, O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, H. A.; Christie, W.; Coffin, J. P.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Das, S.; Daugherity, M.; de Moura, M. M.; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; Didenko, L.; Dietel, T.; Djawotho, P.; Dogra, S. M.; Dong, W. J.; Dong, X.; Draper, J. E.; Du, F.; Dunin, V. B.; Dunlop, J. C.; Dutta Mazumdar, M. R.; Eckardt, V.; Edwards, W. R.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Fornazier, K. S. F.; Fu, J.; Gagliardi, C. A.; Gaillard, L.; Gans, J.; Ganti, M. S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J. E.; Gorbunov, Y. G.; Gos, H.; Grachov, O.; Grebenyuk, O.; Grosnick, D.; Guertin, S. M.; Guo, Y.; Gupta, A.; Gupta, N.; Gutierrez, T. D.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Henry, T. W.; Hepplemann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G. W.; Horner, M. J.; Huang, H. Z.; Huang, S. L.; Hughes, E. W.; Humanic, T. J.; Igo, G.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P. G.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev, V. Yu.; Kim, B. C.; Kiryluk, J.; Kisiel, A.; Kislov, E. M.; Klein, S. R.; Koetke, D. D.; Kollegger, T.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kowalik, K. L.; Kramer, M.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kumar, A.; Kuznetsov, A. A.; Lamont, M. A. C.; Landgraf, J. M.; Lange, S.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lehocka, S.; Levine, M. J.; Li, C.; Li, Q.; Li, Y.; Lin, G.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Liu, Z.; Ljubicic, T.; Llope, W. J.; Long, H.; Longacre, R. S.; Lopez-Noriega, M.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, J. G.; Ma, Y. G.; Magestro, D.; Mahajan, S.; Mahapatra, D. P.; Majka, R.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Martin, L.; Matis, H. S.; Matulenko, Yu. A.; McClain, C. J.; McShane, T. S.; Melnick, Yu.; Meschanin, A.; Miller, M. L.; Minaev, N. G.; Mioduszewski, S.; Mironov, C.; Mischke, A.; Mishra, D. K.; Mitchell, J.; Mohanty, B.; Molnar, L.; Moore, C. F.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nayak, S. K.; Nayak, T. K.; Nelson, J. M.; Netrakanti, P. K.; Nikitin, V. A.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Pachr, M.; Pal, S. K.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Petrov, V. A.; Phatak, S. C.; Picha, R.; Planinic, M.; Pluta, J.; Poljak, N.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potekhin, M.; Potrebenikova, E.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Putschke, J.; Rakness, G.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Razin, S. V.; Reinnarth, J.; Relyea, D.; Retiere, F.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Sahoo, R.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarsour, M.; Savin, I.; Sazhin, P. S.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schweda, K.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shen, W. Q.; Shimanskiy, S. S.; Sichtermann, E.; Simon, F.; Singaraju, R. N.; Smirnov, N.; Snellings, R.; Sood, G.; Sorensen, P.; Sowinski, J.; Speltz, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Sugarbaker, E.; Sumbera, M.; Sun, Z.; Surrow, B.; Swanger, M.; Symons, T. J. M.; Szanto de Toledo, A.; Tai, A.; Takahashi, J.; Tang, A. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Timmins, A. R.; Timoshenko, S.; Tokarev, M.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; van Buren, G.; van der Kolk, N.; van Leeuwen, M.

    2006-06-01

    We present the transverse momentum (p) spectra for identified charged pions, protons and anti-protons from p+p and d+Au collisions at s=200 GeV. The spectra are measured around midrapidity (|y|<0.5) over the range of 0.3momentum range where particle production is dominated by hard processes (p?2 GeV/c). The nuclear modification factor around midrapidity is found to be greater than unity for charged pions and to be even larger for protons at 2

  7. Identified hadron spectra at large transverse momentum in p + p and d + Au collisions at ?{sNN} = 200 GeV

    NASA Astrophysics Data System (ADS)

    Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Anderson, M.; Arkhipkin, D.; Averichev, G. S.; Badyal, S. K.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Bekele, S.; Belaga, V. V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Bezverkhny, B. I.; Bharadwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Billmeier, A.; Bland, L. C.; Blyth, C. O.; Blyth, S.-L.; Bonner, B. E.; Botje, M.; Bouchet, J.; Brandin, A. V.; Bravar, A.; Bystersky, M.; Cadman, R. V.; Cai, X. Z.; Caines, H.; de la Barca Sánchez, M. Calderón; Castillo, J.; Catu, O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, H. A.; Christie, W.; Coffin, J. P.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Das, S.; Daugherity, M.; de Moura, M. M.; Dedovich, T. G.; DePhillips, M.; Derevschikov, A. A.; Didenko, L.; Dietel, T.; Djawotho, P.; Dogra, S. M.; Dong, W. J.; Dong, X.; Draper, J. E.; Du, F.; Dunin, V. B.; Dunlop, J. C.; Dutta Mazumdar, M. R.; Eckardt, V.; Edwards, W. R.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Fornazier, K. S. F.; Fu, J.; Gagliardi, C. A.; Gaillard, L.; Gans, J.; Ganti, M. S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J. E.; Gorbunov, Y. G.; Gos, H.; Grachov, O.; Grebenyuk, O.; Grosnick, D.; Guertin, S. M.; Guo, Y.; Gupta, A.; Gupta, N.; Gutierrez, T. D.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Henry, T. W.; Hepplemann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G. W.; Horner, M. J.; Huang, H. Z.; Huang, S. L.; Hughes, E. W.; Humanic, T. J.; Igo, G.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P. G.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev, V. Yu.; Kim, B. C.; Kiryluk, J.; Kisiel, A.; Kislov, E. M.; Klein, S. R.; Koetke, D. D.; Kollegger, T.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kowalik, K. L.; Kramer, M.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kumar, A.; Kuznetsov, A. A.; Lamont, M. A. C.; Landgraf, J. M.; Lange, S.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lehocka, S.; LeVine, M. J.; Li, C.; Li, Q.; Li, Y.; Lin, G.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Liu, Z.; Ljubicic, T.; Llope, W. J.; Long, H.; Longacre, R. S.; Lopez-Noriega, M.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, J. G.; Ma, Y. G.; Magestro, D.; Mahajan, S.; Mahapatra, D. P.; Majka, R.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Martin, L.; Matis, H. S.; Matulenko, Yu. A.; McClain, C. J.; McShane, T. S.; Melnick, Yu.; Meschanin, A.; Miller, M. L.; Minaev, N. G.; Mioduszewski, S.; Mironov, C.; Mischke, A.; Mishra, D. K.; Mitchell, J.; Mohanty, B.; Molnar, L.; Moore, C. F.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nayak, S. K.; Nayak, T. K.; Nelson, J. M.; Netrakanti, P. K.; Nikitin, V. A.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Pachr, M.; Pal, S. K.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Petrov, V. A.; Phatak, S. C.; Picha, R.; Planinic, M.; Pluta, J.; Poljak, N.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potekhin, M.; Potrebenikova, E.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Putschke, J.; Rakness, G.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Razin, S. V.; Reinnarth, J.; Relyea, D.; Retiere, F.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Sahoo, R.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarsour, M.; Savin, I.; Sazhin, P. S.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schweda, K.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shen, W. Q.; Shimanskiy, S. S.; Sichtermann, E.; Simon, F.; Singaraju, R. N.; Smirnov, N.; Snellings, R.; Sood, G.; Sorensen, P.; Sowinski, J.; Speltz, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Sugarbaker, E.; Sumbera, M.; Sun, Z.; Surrow, B.; Swanger, M.; Symons, T. J. M.; Szanto de Toledo, A.; Tai, A.; Takahashi, J.; Tang, A. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Timmins, A. R.; Timoshenko, S.; Tokarev, M.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van der Kolk, N.; van Leeuwen, M.

    2006-06-01

    We present the transverse momentum (pT) spectra for identified charged pions, protons and anti-protons from p + p and d + Au collisions at ?{sNN} = 200 GeV. The spectra are measured around midrapidity (| y | < 0.5) over the range of 0.3 momentum range where particle production is dominated by hard processes (pT ? 2 GeV / c). The nuclear modification factor around midrapidity is found to be greater than unity for charged pions and to be even larger for protons at 2

  8. Ultra-large scale AFM of lipid droplet arrays: investigating the ink transfer volume in dip pen nanolithography.

    PubMed

    Förste, Alexander; Pfirrmann, Marco; Sachs, Johannes; Gröger, Roland; Walheim, Stefan; Brinkmann, Falko; Hirtz, Michael; Fuchs, Harald; Schimmel, Thomas

    2015-05-01

    There are only few quantitative studies commenting on the writing process in dip-pen nanolithography with lipids. Lipids are important carrier ink molecules for the delivery of bio-functional patters in bio-nanotechnology. In order to better understand and control the writing process, more information on the transfer of lipid material from the tip to the substrate is needed. The dependence of the transferred ink volume on the dwell time of the tip on the substrate was investigated by topography measurements with an atomic force microscope (AFM) that is characterized by an ultra-large scan range of 800 × 800 ?m(2). For this purpose arrays of dots of the phospholipid1,2-dioleoyl-sn-glycero-3-phosphocholine were written onto planar glass substrates and the resulting pattern was imaged by large scan area AFM. Two writing regimes were identified, characterized of either a steady decline or a constant ink volume transfer per dot feature. For the steady state ink transfer, a linear relationship between the dwell time and the dot volume was determined, which is characterized by a flow rate of about 16 femtoliters per second. A dependence of the ink transport from the length of pauses before and in between writing the structures was observed and should be taken into account during pattern design when aiming at best writing homogeneity. The ultra-large scan range of the utilized AFM allowed for a simultaneous study of the entire preparation area of almost 1 mm(2), yielding good statistic results. PMID:25854547

  9. The pion form factor: Sudakov suppressions and intrinsic transverse momentum

    E-print Network

    R. Jakob; P. Kroll

    1993-06-11

    It is demonstrated that any attempt to calculate the perturbative QCD contribution to the pion form factor requires the inclusion of intrinsic transverse momentum besides Sudakov form factors. For momentum transfers of the order of a few GeV the intrinsic transverse momentum leads to a substantial suppression of the perturbative QCD contribution.

  10. Ion Momentum Spectrometry

    E-print Network

    Bapat, Bhas

    Ion Momentum Spectrometry Bhas Bapat Fragmentation of Molecular Ions multi-fold differential cross data acquisition sample spectra Momentum Maps multi-ion-coincidence momentum analysis Issues and Examples Electron-impact DI of methanol Photoionisation of CO2 DI of CCl + 4 Summary Ion Momentum

  11. Large work function difference driven electron transfer from electrides to single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Menamparambath, Mini Mol; Park, Jong-Ho; Yoo, Ho-Sung; Patole, Shashikant P.; Yoo, Ji-Beom; Kim, Sung Wng; Baik, Seunghyun

    2014-07-01

    A difference in work function plays a key role in charge transfer between two materials. Inorganic electrides provide a unique opportunity for electron transfer since interstitial anionic electrons result in a very low work function of 2.4-2.6 eV. Here we investigated charge transfer between two different types of electrides, [Ca2N]+.e- and [Ca24Al28O64]4+.4e-, and single-walled carbon nanotubes (SWNTs) with a work function of 4.73-5.05 eV. [Ca2N]+.e- with open 2-dimensional electron layers was more effective in donating electrons to SWNTs than closed cage structured [Ca24Al28O64]4+.4e- due to the higher electron concentration (1.3 × 1022 cm-3) and mobility (~200 cm2 V-1 s-1 at RT). A non-covalent conjugation enhanced near-infrared fluorescence of SWNTs as high as 52%. The field emission current density of electride-SWNT-silver paste dramatically increased by a factor of 46 000 (14.8 mA cm-2) at 2 V ?m-1 (3.5 wt% [Ca2N]+.e-) with a turn-on voltage of 0.85 V ?m-1.A difference in work function plays a key role in charge transfer between two materials. Inorganic electrides provide a unique opportunity for electron transfer since interstitial anionic electrons result in a very low work function of 2.4-2.6 eV. Here we investigated charge transfer between two different types of electrides, [Ca2N]+.e- and [Ca24Al28O64]4+.4e-, and single-walled carbon nanotubes (SWNTs) with a work function of 4.73-5.05 eV. [Ca2N]+.e- with open 2-dimensional electron layers was more effective in donating electrons to SWNTs than closed cage structured [Ca24Al28O64]4+.4e- due to the higher electron concentration (1.3 × 1022 cm-3) and mobility (~200 cm2 V-1 s-1 at RT). A non-covalent conjugation enhanced near-infrared fluorescence of SWNTs as high as 52%. The field emission current density of electride-SWNT-silver paste dramatically increased by a factor of 46 000 (14.8 mA cm-2) at 2 V ?m-1 (3.5 wt% [Ca2N]+.e-) with a turn-on voltage of 0.85 V ?m-1. Electronic supplementary information (ESI) available: The acronyms of base materials and synthesized specimens, field emission characteristics of PSWNT-Ag paste and HSWNT-Ag paste, additional XPS and Raman data, estimation of transferred electrons from electrides to nanotubes, optical images of C12A7:e--HSWNT films, a SEM image of the tape-activated PSWNT-Ag paste, and comparison of field emission properties. See DOI: 10.1039/c4nr01629g

  12. Experimental deuteron momentum distributions with reduced final state interactions

    NASA Astrophysics Data System (ADS)

    Khanal, Hari P.

    This dissertation presents a study of the D( e, e'p)n reaction carried out at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) for a set of fixed values of four-momentum transfer Q 2 = 2.1 and 0.8 (GeV/c)2 and for missing momenta pm ranging from pm = 0.03 to pm = 0.65 GeV/c. The analysis resulted in the determination of absolute D(e,e' p)n cross sections as a function of the recoiling neutron momentum and it's scattering angle with respect to the momentum transfer [vector] q. The angular distribution was compared to various modern theoretical predictions that also included final state interactions. The data confirmed the theoretical prediction of a strong anisotropy of final state interaction contributions at Q2 of 2.1 (GeV/c)2 while at the lower Q2 value, the anisotropy was much less pronounced. At Q2 of 0.8 (GeV/c)2, theories show a large disagreement with the experimental results. The experimental momentum distribution of the bound proton inside the deuteron has been determined for the first time at a set of fixed neutron recoil angles. The momentum distribution is directly related to the ground state wave function of the deuteron in momentum space. The high momentum part of this wave function plays a crucial role in understanding the short-range part of the nucleon-nucleon force. At Q2 = 2.1 (GeV/c)2, the momentum distribution determined at small neutron recoil angles is much less affected by FSI compared to a recoil angle of 75°. In contrast, at Q2 = 0.8 (GeV/c)2 there seems to be no region with reduced FSI for larger missing momenta. Besides the statistical errors, systematic errors of about 5--6 % were included in the final results in order to account for normalization uncertainties and uncertainties in the determi- nation of kinematic veriables. The measurements were carried out using an electron beam energy of 2.8 and 4.7 GeV with beam currents between 10 to 100 ? A. The scattered electrons and the ejected protons originated from a 15cm long liquid deuterium target, and were detected in conicidence with the two high resolution spectrometers of Hall A at Jefferson Lab.

  13. Momentum harvesting techniques for solar system travel

    NASA Technical Reports Server (NTRS)

    Willoughby, Alan J.

    1991-01-01

    Astronomers are lately estimating there are 400,000 earth visiting asteroids larger than 100 meters in diameter. These asteroids are uniquely accessible sources of building materials, propellants, oxygen, water, and minerals. They also constitute a huge momentum reserve, potentially usable for travel throughout the solar system. To use this momentum, these stealthy objects must be tracked and the ability to extract the desired momentum obtained. Momentum harvesting by momentum transfer from asteroid to spacecraft, and by using the momentum of the extraterrestrial material to help deliver itself to its destination is discussed. The purpose is neither to quantify nor justify the momentum exchange processes, but to stimulate collective imaginations with some intriguing possibilities which emerge when momentum as well as material is considered. A net and tether concept is the suggested means of asteroid capture, the basic momentum exchange process. The energy damping characteristics of the tether determines the velocity mismatch that can be tolerated, and hence the amount of momentum that can be harvested per capture. As the tether plays out of its reel, drag on the tether steadily accelerates the spacecraft and dilutes, in time, the would-be collision. A variety of concepts for riding and using asteroids after capture are introduced. The hitchhiker uses momentum transfer only. The beachcomber, the caveman, the swinger, the prospector, and the rock wrecker also take advantage of raw asteroid materials. The chemist and the hijacker go further, they process the asteroid into propellants. Or, an asteroid railway system could be constructed with each hijacked asteroid becoming a scheduled train. Travelers could board this space railway system assured that water, oxygen propellants, and shielding await them. Austere space travel could give way to comforts, with a speed and economy impossible without nature's gift of earth visiting asteroids.

  14. Experimental research on heat transfer of natural convection in vertical rectangular channels with large aspect ratio

    SciTech Connect

    Lu, Qing; Qiu, Suizheng; Su, Guanghui [State Key Laboratory of Multi Phase Flow in Power Engineering, Xi'an JIaotong University, Xi'an, Shaanxi 710049 (China); School of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China); Tian, Wenxi; Ye, Zhonghao [School of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)

    2010-01-15

    This work presents the experimental research on the steady laminar natural convection heat transfer of air in three vertical thin rectangular channels with different gap clearance. The much higher ratio of width to gap clearance (60-24) and the ratio of length to gap clearance (800-320) make the rectangular channels similar with the coolant flow passage in plate type fuel reactors. The vertical rectangular channels were composed of two stainless steal plates and were heated by electrical heating rods. The wall temperatures were detected with the K-type thermocouples which were inserted into the blind holes drilled in the steal plates. Also the air temperatures at the inlet and outlet of the channel were detected. The wall heat fluxes added to the air flow were calculated by the Fourier heat conduction law. The heat transfer characteristics were analyzed, and the average Nusselt numbers in all the three channels could be well correlated with the Rayleigh number or the modified Rayleigh number in a uniform correlation. Furthermore, the maximum wall temperatures were investigated, which is a key parameter for the fuel's integrity during some accidents. It was found that even the wall heat flux was up to 1500 W/m{sup 2}, the maximum wall temperature was lower than 350 C. All this work is valuable for the plate type reactor's design and safety analysis. (author)

  15. Reconstruction of large cranial defects in the presence of heavy radiation damage and infection utilizing tissue transferred by microvascular anastomoses

    SciTech Connect

    Robson, M.C.; Zachary, L.S.; Schmidt, D.R.; Faibisoff, B.; Hekmatpanah, J.

    1989-03-01

    Six cases of large defects of the scalp, skull, and dura following tumor ablation and radiation are presented. Each was accompanied by chronic infection in the irradiated defect. Efforts to reconstruct the resulting defects with local flaps were not successful. One-stage reconstruction was then accomplished in each case utilizing a latissimus dorsi musculocutaneous or myo-osteocutaneous free flap transferred by microvascular anastomoses. The versatility of the latissimus dorsi musculocutaneous and/or osseous flap allows single-stage reconstruction of these complex defects.

  16. Influence of Convective Momentum Transport on Tropical Waves

    NASA Astrophysics Data System (ADS)

    Zhou, L.

    2012-12-01

    Convective momentum transport (CMT) has been found to play an important role during the Madden-Julian Oscillation (MJO). Influences of CMT on tropical waves are analytically studied in a two-layer model, which captures the first-order baroclinic structure in the vertical. Since CMT is the momentum exchange between the lower and the upper troposphere during convection, the easterly and westerly vertical shears of background zonal winds lead to different CMT influences. Generally, CMT plays more important roles than a damping term to tropical waves. CMT is a critical factor for determining the meridional scale of tropical waves and leads to kinetic energy transfer against the direction of background wind shear in the vertical. CMT can also be favorable for internal instability and induce upscale momentum transfer. Specifically, due to CMT, the meridional scale in the two-layer model is wider than the Rossby radius of deformation (RL, the meridional scale of tropical waves in the classical theory) over the Indo-Pacific warm pool, but narrower than RL from the central to the eastern Pacific Ocean and over the Atlantic Ocean. Such variation is consistent with observations. CMT results in minor modifications to the speeds of Rossby waves, inertial gravity waves, and Kelvin waves. Nevertheless, CMT has significant influences on the mixed Rossby-gravity (MRG) waves, especially over the Indo-Pacific warm pool where the vertical wind shear in easterly. Westward propagating MRG waves with small wavenumber become unstable under the influence of CMT. The phase relation between the convergence and geopotential is no longer in quadrature, which is different from classical MRG waves. As a result, there is a net source of mechanical energy within one period and there is an upscale momentum transfer from the perturbed field to large scale velocities. This theoretical study sheds lights on the relation between CMT and slow variations in the atmosphere, including MJO.

  17. Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at ?{sNN}=2.76 TeV

    NASA Astrophysics Data System (ADS)

    Abelev, B.; Adam, J.; Adamová, D.; Adare, A. M.; Aggarwal, M. M.; Aglieri Rinella, G.; Agocs, A. G.; Agostinelli, A.; Aguilar Salazar, S.; Ahammed, Z.; Ahmad, N.; Ahmad Masoodi, A.; Ahn, S. A.; Ahn, S. U.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Almaráz Aviña, E.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Altsybeev, I.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Anson, C.; Anti?i?, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arbor, N.; Arcelli, S.; Arend, A.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Asryan, A.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Äystö, J.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bailhache, R.; Bala, R.; Baldini Ferroli, R.; Baldisseri, A.; Baldit, A.; Baltasar Dos Santos Pedrosa, F.; Bán, J.; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batyunya, B.; Baumann, C.; Bearden, I. G.; Beck, H.; Behera, N. K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bergognon, A. A. E.; Berzano, D.; Betev, L.; Bhasin, A.; Bhati, A. K.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Biel?ík, J.; Biel?íková, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Boccioli, M.; Bock, N.; Böttger, S.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bose, S.; Bossú, F.; Botje, M.; Botta, E.; Boyer, B.; Braidot, E.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Browning, T. A.; Broz, M.; Brun, R.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Busch, O.; Buthelezi, Z.; Caballero Orduna, D.; Caffarri, D.; Cai, X.; Caines, H.; Calvo Villar, E.; Camerini, P.; Canoa Roman, V.; Cara Romeo, G.; Carena, F.; Carena, W.; Carlin Filho, N.; Carminati, F.; Casanova Díaz, A.; Castillo Castellanos, J.; Castillo Hernandez, J. F.; Casula, E. A. R.; Catanescu, V.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chawla, I.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Coccetti, F.; Colamaria, F.; Colella, D.; Conesa Balbastre, G.; Conesa Del Valle, Z.; Constantin, P.; Contin, G.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Cotallo, M. E.; Crescio, E.; Crochet, P.; Cruz Alaniz, E.; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dalsgaard, H. H.; Danu, A.; Das, D.; Das, I.; Das, K.; Dash, A.; Dash, S.; de, S.; de Barros, G. O. V.; de Caro, A.; de Cataldo, G.; de Cuveland, J.; de Falco, A.; de Gruttola, D.; Delagrange, H.; Deloff, A.; Demanov, V.; De Marco, N.; Dénes, E.; de Pasquale, S.; Deppman, A.; D Erasmo, G.; de Rooij, R.; Diaz Corchero, M. A.; di Bari, D.; Dietel, T.; di Giglio, C.; di Liberto, S.; di Mauro, A.; di Nezza, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Domínguez, I.; Dönigus, B.; Dordic, O.; Driga, O.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, M. R.; Dutta Majumdar, A. K.; Elia, D.; Emschermann, D.; Engel, H.; Erazmus, B.; Erdal, H. A.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Eyyubova, G.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fearick, R.; Fedunov, A.; Fehlker, D.; Feldkamp, L.; Felea, D.; Fenton-Olsen, B.; Feofilov, G.; Fernández Téllez, A.; Ferretti, A.; Ferretti, R.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Garishvili, I.; Gerhard, J.; Germain, M.; Geuna, C.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Gianotti, P.; Girard, M. R.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez, R.; Ferreiro, E. G.; González-Trueba, L. H.; González-Zamora, P.; Gorbunov, S.; Goswami, A.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Grajcarek, R.; Grelli, A.; Grigoras, C.; Grigoras, A.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gros, P.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.

    2013-03-01

    The inclusive transverse momentum (pT) distributions of primary charged particles are measured in the pseudo-rapidity range |?|<0.8 as a function of event centrality in Pb-Pb collisions at ?{sNN}=2.76 TeV with ALICE at the LHC. The data are presented in the pT range 0.1530 GeV/c. In peripheral collisions (70-80%), only moderate suppression (RAA=0.6-0.7) and a weak pT dependence is observed. The measured nuclear modification factors are compared to other measurements and model calculations.

  18. Using LIONS to Transfer Large Files (via FTP) The LIONS system has been available on the University for some time. It is used by the academic community

    E-print Network

    Using LIONS to Transfer Large Files (via FTP) The LIONS system has been available on the University for transferring files to and from the University. There are some specific issues with using LIONS FTP that users FTP). However, those directories are not browseable by anyone other than authenticated LIONS users

  19. Large Electron Transfer Rate Effects from the Duschinsky Mixing of Vibrations Gerald M. Sando, Kenneth G. Spears,* and Joseph T. Hupp

    E-print Network

    Large Electron Transfer Rate Effects from the Duschinsky Mixing of Vibrations Gerald M. Sando and nontotally symmetric vibrations are very important. The Duschinsky effect arises when two electronic states. Introduction Electron transfer (ET) reactivity has been the subject of enormous theoretical attention due

  20. The Transfer of Evolved Artificial Immune System Behaviours between Small and Large Scale Robotic Platforms

    E-print Network

    Whitbrook, Amanda; Garibaldi, Jonathan M

    2010-01-01

    This paper demonstrates that a set of behaviours evolved in simulation on a miniature robot (epuck) can be transferred to a much larger scale platform (a virtual Pioneer P3-DX) that also differs in shape, sensor type, sensor configuration and programming interface. The chosen architecture uses a reinforcement learning-assisted genetic algorithm to evolve the epuck behaviours, which are encoded as a genetic sequence. This sequence is then used by the Pioneers as part of an adaptive, idiotypic artificial immune system (AIS) control architecture. Testing in three different simulated worlds shows that the Pioneer can use these behaviours to navigate and solve object-tracking tasks successfully, as long as its adaptive AIS mechanism is in place.

  1. Electron scattering from high-momentum neutrons in deuterium

    SciTech Connect

    Klimenko, A.V.; Kuhn, S.E.; Bueltmann, S.; Careccia, S.L.; Dharmawardane, K.V.; Dodge, G.E.; Guler, N.; Hyde-Wright, C.E.; Klein, A.; Tkachenko, S.; Weinstein, L.B.; Zhang, J. [Old Dominion University, Norfolk, Virginia 23529 (United States); Butuceanu, C.; Griffioen, K.A.; Baillie, N.; Fersch, R.G.; Funsten, H. [College of William and Mary, Williamsburg, Virginia 23187 (United States); Egiyan, K.S.; Asryan, G.; Dashyan, N.B. [Yerevan Physics Institute, 375036 Yerevan (Armenia)] (and others)

    2006-03-15

    We report results from an experiment measuring the semiinclusive reaction {sup 2}H(e,e{sup '}p{sub s}) in which the proton p{sub s} is moving at a large angle relative to the momentum transfer. If we assume that the proton was a spectator to the reaction taking place on the neutron in deuterium, the initial state of that neutron can be inferred. This method, known as spectator tagging, can be used to study electron scattering from high-momentum (off-shell) neutrons in deuterium. The data were taken with a 5.765 GeV electron beam on a deuterium target in Jefferson Laboratory's Hall B, using the CEBAF large acceptance spectrometer. A reduced cross section was extracted for different values of final state missing mass W*, backward proton momentum p{sup {yields}}{sub s}, and momentum transfer Q{sup 2}. The data are compared to a simple plane wave impulse approximation (PWIA) spectator model. A strong enhancement in the data observed at transverse kinematics is not reproduced by the PWIA model. This enhancement can likely be associated with the contribution of final state interactions (FSI) that were not incorporated into the model. Within the framework of the simple spectator model, a 'bound neutron structure function' F{sub 2n}{sup eff} was extracted as a function of W* and the scaling variable x* at extreme backward kinematics, where the effects of FSI appear to be smaller. For p{sub s}>0.4 GeV/c, where the neutron is far off-shell, the model overestimates the value of F{sub 2n}{sup eff} in the region of x* between 0.25 and 0.6. A dependence of the bound neutron structure function on the neutron's 'off-shell-ness' is one possible effect that can cause the observed deviation.

  2. Moving Water on a Malleable Planet - Large Scale Inter-basin Hydrological Transfers Now and in the Future

    NASA Astrophysics Data System (ADS)

    Lammers, R. B.; Proussevitch, A. A.; Frolking, S.; Grogan, D. S.

    2012-12-01

    Humans have been reorganizing the land surface components of the hydrological cycle for some time. One of the more hydrologically important changes are diversions of river water from one watershed to another. These are often initiated to mitigate water shortages in neighboring drainage basins or to increase the output of hydroelectric energy production. We describe a database of macro-scale inter-basin hydrological transfers covering all parts of the globe. The focus is on large-scale changes in the flow of water from one drainage basin to another or between sub-basins within the same watershed. Current counts from the database show several hundred identified diversions across five continents. Engineering works under construction as well as those that have been planned or proposed were included. Large projects now under construction in China (South-North Water Transfer Project) and planned in India (Himalayan and Peninsular components of the National River Linking Project) represent some of largest human created movements of water on the planet. We also explore the implications of the more speculative plans that have emerged over the last half century such as the Northern River Reversal, designed to deliver water from Siberia to Central Asia, and the North American Water and Power Alliance (NAWAPA) project linking high latitude rivers in Alaska and Canada to areas of the American southwest. The database has allowed us to explore, through hydrological modeling, the global impact of these engineering works. We also explore scenarios of changes in future water resources by looking at the inter-basin transfers against a suite of anticipated climate change from model output driven by the IPCC AR5 data set.

  3. Angular Momentum in QGP Holography

    E-print Network

    Brett McInnes

    2014-08-25

    The quark chemical potential is one of the fundamental parameters describing the Quark-Gluon Plasma produced by sufficiently energetic heavy-ion collisions. It is not large at the extremely high temperatures probed by the LHC, but it plays a key role in discussions of the beam energy scan programmes at the RHIC and other facilities. On the other hand, collisions at such energies typically (that is, in peripheral collisions) give rise to very high values of the angular momentum density. Here we explain that holographic estimates of the quark chemical potential of a rotating sample of plasma can be very considerably improved by taking the angular momentum into account.

  4. Light's Orbital Angular Momentum

    Microsoft Academic Search

    Miles Padgett; Johannes Courtial; Les Allen

    2004-01-01

    The realization that light beams can have quantized orbital angular momentum in addition to spin angular momentum has led, in recent years, to novel experiments in quantum mechanics and new methods for manipulating microparticles.

  5. Angular Momentum Experiment

    NSDL National Science Digital Library

    David Trapp

    After using the historical development of concepts of conserved motion to develop introductory understanding, students are directed to a series of activities to gain a better understanding of momentum, conservation of momenta, angular momentum, and conservation of angular momenta.

  6. Heat transfer in a large triangular-roof enclosure based on the second law analysis

    NASA Astrophysics Data System (ADS)

    Ziapour, Behrooz M.; Dehnavi, Resam

    2014-11-01

    Application of entropy generation minimization method for the optimization of natural convection in triangular-roof enclosures can be helpful in enhancing the thermodynamic efficiency of the system. In this paper, the numerical solution of the entropy production was performed due to natural convection of laminar air flow in a large isosceles triangular-roof enclosure with different boundary conditions such as the greenhouses conjugate boundary conditions. The simulation results showed that the entropy generation number in an enclosure with partially heated from bottom wall center, is less than an enclosure with partially heated from bottom wall corner. Also, in a large triangular-roof greenhouse, the entropy generation number decreases with increasing of the greenhouse aspect ratio (L/H).

  7. Large carbon cluster thin film gauges for measuring aerodynamic heat transfer rates in hypersonic shock tunnels

    NASA Astrophysics Data System (ADS)

    Srinath, S.; Reddy, K. P. J.

    2015-02-01

    Different types of Large Carbon Cluster (LCC) layers are synthesized by a single-step pyrolysis technique at various ratios of precursor mixture. The aim is to develop a fast responsive and stable thermal gauge based on a LCC layer which has relatively good electrical conduction in order to use it in the hypersonic flow field. The thermoelectric property of the LCC layer has been studied. It is found that these carbon clusters are sensitive to temperature changes. Therefore suitable thermal gauges were developed for blunt cone bodies and were tested in hypersonic shock tunnels at a flow Mach number of 6.8 to measure aerodynamic heating. The LCC layer of this thermal gauge encounters high shear forces and a hostile environment for test duration in the range of a millisecond. The results are favorable to use large carbon clusters as a better sensor than a conventional platinum thin film gauge in view of fast responsiveness and stability.

  8. Enabling Large Data Transfers on Dynamic, Very High-Speed Network Infrastructures

    Microsoft Academic Search

    Dino M. López-pacheco; Congduc Pham

    2006-01-01

    High-speed networks are being built using the most upto- date networking technologies such as optical fibers with dense wavelength multiplexing (DWDM) in order to meet the performance constraints of large scientific problems (grid infrastructures) or new multimedia applications. As technologies are moving forwards, many high-speed network infrastructures have amazing capabilities in the order of several gigabits\\/s. Our work focuses on

  9. Direct measurements of momentum and latent heat transfer coefficients during the GasExIII 2008 field program in the Southern Ocean: Comparisons with the COARE3.0 bulk flux algorithm

    NASA Astrophysics Data System (ADS)

    Fairall, C.; Bariteau, L.; Hare, J.; Pezoa, S.; Edson, J.; Cifuentes-Lorenzen, A.; McGillis, W.; Zappa, C.

    2008-12-01

    In 2008 a six-week research expedition aboard the NOAA Ship Ronald H. Brown was conducted with sponsorship from NASA, NOAA, and NSF. The Southern Ocean Gas Exchange Experiment departed Feb. 28 from Punta Arenas, Chile, and spent most of its time in the storm track east of the Southern tip of S. America (51 S 36 W). Scientists from dozens of universities and research institutions were on board to measure turbulence, waves, bubbles, temperature, ocean chemistry and biology, and investigate how these factors relate to the air-sea exchange of carbon dioxide and other climate-relevant gases. A consortium of researchers from NOAA/ESRL - U. Colorado, U. Connecticut, Columbia U., and U. Hawaii cooperated on comprehensive suite of instruments to make direct motion-corrected covariance and inertial-dissipation flux measurements and associated forcing variables such as near-surface bulk meteorology, surface waves and whitecap fraction. In this paper we report on analysis of the turbulent fluxes of momentum and water vapor and a comparison of the bulk transfer coefficients with the COARE algorithm (version 3.0).

  10. Precision measurement of longitudinal and transverse response functions of quasi-elastic electron scattering in the momentum transfer range 0.55GeV/c lte math| lte 0.9GeV/c

    SciTech Connect

    Huan Yao, Jefferson Lab Hall A Collaboration, E05-110 Collaboration

    2012-04-01

    In order to test the Coulomb sum rule in nuclei, a precision measurement of inclusive electron scattering cross sections in the quasi-elastic region was performed at Jefferson Lab. Incident electrons of energies ranging from 0.4 GeV/c to 4 GeV/c scattered off {sup 4}He, {sup 12}C, {sup 56}Fe and {sup 208}Pb nuclei at four scattering angles (15deg., 60deg., 90deg., 120deg.) and scattered energies ranging from 0.1 GeV/c to 4 GeV/c. The Rosenbluth method with proper Coulomb corrections is used to extract the transverse and longitudinal response functions at three-momentum transfers 0.55 GeV/c {le} |q{yields}| {le} 1.0 GeV/c. The Coulomb Sum is determined in the same |q{yields}| range as mentioned above and will be compared to predictions. Analysis progress and preliminary results will be presented.

  11. Introducing Electromagnetic Field Momentum

    ERIC Educational Resources Information Center

    Hu, Ben Yu-Kuang

    2012-01-01

    I describe an elementary way of introducing electromagnetic field momentum. By considering a system of a long solenoid and line charge, the dependence of the field momentum on the electric and magnetic fields can be deduced. I obtain the electromagnetic angular momentum for a point charge and magnetic monopole pair partially through dimensional…

  12. A polymer, random walk model for the size-distribution of large DNA fragments after high linear energy transfer radiation

    NASA Technical Reports Server (NTRS)

    Ponomarev, A. L.; Brenner, D.; Hlatky, L. R.; Sachs, R. K.

    2000-01-01

    DNA double-strand breaks (DSBs) produced by densely ionizing radiation are not located randomly in the genome: recent data indicate DSB clustering along chromosomes. Stochastic DSB clustering at large scales, from > 100 Mbp down to < 0.01 Mbp, is modeled using computer simulations and analytic equations. A random-walk, coarse-grained polymer model for chromatin is combined with a simple track structure model in Monte Carlo software called DNAbreak and is applied to data on alpha-particle irradiation of V-79 cells. The chromatin model neglects molecular details but systematically incorporates an increase in average spatial separation between two DNA loci as the number of base-pairs between the loci increases. Fragment-size distributions obtained using DNAbreak match data on large fragments about as well as distributions previously obtained with a less mechanistic approach. Dose-response relations, linear at small doses of high linear energy transfer (LET) radiation, are obtained. They are found to be non-linear when the dose becomes so large that there is a significant probability of overlapping or close juxtaposition, along one chromosome, for different DSB clusters from different tracks. The non-linearity is more evident for large fragments than for small. The DNAbreak results furnish an example of the RLC (randomly located clusters) analytic formalism, which generalizes the broken-stick fragment-size distribution of the random-breakage model that is often applied to low-LET data.

  13. arXiv:hep-ex/0006022v116Jun2000 Photoproduction of (1020) Mesons on the Proton at Large Momentum Transfer

    E-print Network

    .J. Amaryan,35 M. Anghinolfi,2 D. Armstrong,7 B. Asavapibhop,27 H. Avakian,17 S. Barrow,10 K. Beard,15 M of Physics, Taegu 702-701, South Korea 17 Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di

  14. Transfer of fine sediments and particulate heavy metals in large river basins

    NASA Astrophysics Data System (ADS)

    Scherer, Ulrike; Reid, Lucas; Fuchs, Stephan

    2013-04-01

    For heavy metals and other particulate contaminants erosion is an important emission pathway into surface waters. Emissions via erosion can strongly vary depending on land use, morphology, erodibility of the soils and the heavy metal content in the topsoil layer of the source areas. A high spatial resolution of input data is thus necessary to identify hotspots of heavy metal emissions via erosion in large river basins. In addition a part of the suspended solid load which is emitted to surface waters from the catchment areas can be deposited in the river system during transportation. The retention of sediments mainly takes place in lakes, reservoirs and river barrages. Former modelling studies in large river basins of Germany revealed, that the observed suspended sediment loads at monitoring stations were strongly overestimated, if retention processes in the river system were neglected. The objective of this study was therefore to test whether the consideration of sedimentation rates in lakes, reservoirs and river barrages can improve the prediction of observed suspended sediment loads in large river basins. We choose the German/Austrian part of the Danube basin until Passau (77 156 km²) for this analysis, as the alpine tributaries in the South of the Danube basin deliver high annual sediment rates (i.e. Inn and Isar) which are not fully recovered at the monitoring stations located further upstream of the Danube due to retention processes. The sediment input was quantified for all tributaries and added up along the flow path of the river system. Due to the large scale, sediment production within the catchments was calculated using the USLE for cultivated land and naturally covered areas and specific erosion rates for alpine areas without vegetation cover. Sediment delivery was estimated using an approach based on the location of the sediment source areas in the catchments and the morphology on the way to the surface waters. The location of the lakes, reservoirs and river barrages were mapped along the flow path in the river system and specific sedimentation rates were calibrated. First results show, that the observed suspended sediment loads at monitoring stations were represented realistically if local sedimentation rates were considered.

  15. Dynamic subgrid-scale models for momentum and scalar fluxes in large-eddy simulations of neutrally stratified atmospheric boundary layers over heterogeneous terrain

    Microsoft Academic Search

    Rob Stoll; Fernando Porté-Agel

    2006-01-01

    The accuracy of large-eddy simulations (LESs) of the atmospheric boundary layer (ABL) over complex terrain relies on the ability of the subgrid-scale (SGS) models to capture the effect of subgrid turbulent fluxes on the resolved fields of velocity and scalars (e.g., heat, water vapor, and pollutants). A common approach consists of parameterizing the SGS stresses and fluxes using eddy viscosity

  16. Large File Transfers from Space Using Multiple Ground Terminals and Delay-Tolerant Networking

    NASA Technical Reports Server (NTRS)

    Ivancic, William D.; Paulsen, Phillip; Stewart, Dave; Eddy, Wesley; McKim, James; Taylor, John; Lynch, Scott; Heberle, Jay; Northam, James; Jackson, Chris; Wood, Lloyd

    2010-01-01

    We use Delay-Tolerant Networking (DTN) to break control loops between space-ground communication links and ground-ground communication links to increase overall file delivery efficiency, as well as to enable large files to be proactively fragmented and received across multiple ground stations. DTN proactive fragmentation and reactive fragmentation were demonstrated from the UK-DMC satellite using two independent ground stations. The files were reassembled at a bundle agent, located at Glenn Research Center in Cleveland Ohio. The first space-based demonstration of this occurred on September 30 and October 1, 2009. This paper details those experiments. Communication, delay-tolerant networking, DTN, satellite, Internet, protocols, bundle, IP, TCP.

  17. Transferring automation for large-scale development and production of Invader SNP assays

    NASA Astrophysics Data System (ADS)

    Neri, Bruce P.; Ganske, R.; Isaczyszyn, W.; Beaty, Edward L.

    2000-03-01

    The Human Genome Project has led to the discovery of hundreds of thousands of single nucleotide polymorphisms (SNPs). SNPs can act as genetic markers to create high- density maps of the human genome for large-scale genetic analysis for evaluating links between genetic mutations and human diseases and for performing association studies. To create those maps, assays capable of detecting many different SNPs must be developed rapidly, as additional SNPs are discovered. When both the design of and the technology used in the assays can be partially or fully automated, the development process and the time to results can be accomplished quickly and efficiently. InvaderTM technology offers a highly sensitive signal amplification system that detects and quantifies mutations and SNPs from unamplified human genomic DNA in two sequential steps.

  18. Fast signal transfer in a large-area X-ray CMOS image sensor

    NASA Astrophysics Data System (ADS)

    Kim, M. S.; Kang, D. U.; Lee, D. H.; Kim, H.; Cho, G.; Jae, M.

    2014-08-01

    For 2-d X-ray imaging, such as mammography and non-destructive test, a sensor should have a large-area because the sensor for typical X-ray beams cannot use optical lens system. To make a large-area 2-d X-ray image sensor using crystal Si, a technique of tiling unit CMOS image sensors into 2 × 2 or 2 × 3 array can be used. In a unit CMOS image sensor made of most common 8-inch Si wafers, the signal line can be up to ~ 180 mm long. Then its parasitic capacitance is up to ~ 25 pF and its resistance is up to ~ 51 k? (0.18 ?m, 1P3M process). This long signal line may enlarge the row time up to ~ 50 ?sec in case of the signal from the top row pixels to the readout amplifiers located at the bottom of the sensor chip. The output signal pulse is typically characterized by three components in sequence; a charging time (a rising part), a reading time and a discharging time (a falling part). Among these, the discharging time is the longest, and it limits the speed or the frame rate of the X-ray imager. We proposed a forced discharging method which uses a bypass transistor in parallel with the current source of the column signal line. A chip for testing the idea was fabricated by a 0.18 ?m process. A active pixel sensor with three transistors and a 3-? RC model of the long line were simulated together. The test results showed that the turning on-and-off of the proposed bypass transistor only during the discharging time could dramatically reduce the discharging time from ~ 50 ?sec to ~ 2 ?sec, which is the physically minimum time determined by the long metal line capacitance.

  19. Ground state isomerism in betacarboline hydrogen bond complexes: The charge transfer nature of its large Stokes shifted emission

    NASA Astrophysics Data System (ADS)

    Sánchez-Coronilla, Antonio; Balón, Manuel; Muñoz, María A.; Hidalgo, José; Carmona, Carmen

    2008-07-01

    The hydrogen bonding and excited state proton transfer reactions between betacarboline, 9 H-pyrido[3,4- b]indole, BC, and 1,1,1,3,3,3-hexafluoropropan-2-ol, HFIP, have been studied in the aprotic solvents cyclohexane and toluene by absorption, steady state and time resolved fluorescence measurements. On the basis of these results and those of previous works (Refs. [A. Sánchez-Coronilla, C. Carmona, M.A. Muñoz, M. Balón, Chem. Phys., 327 (2006) 70] and [A. Sánchez-Coronilla, M. Balón, M.A. Muñoz, C. Carmona, Chem. Phys. 344 (2008) 72]) two main fundamental conclusions can be drawn on the photophysical behaviour of BC. Thus, it is shown, for the first time, that the non-cyclic double hydrogen bond complexes formed through both nitrogen atoms of BC, DHB, can suffer, in their ground state, an isomerisation process. These adducts acquire a quinoid structure in cyclohexane, but maintain a dipolar zwitterionic structure in toluene. Moreover, it is concluded that the observed large Stokes shifted emission, around 520 nm, is not due, as it has been so far generally accepted, to the emission of a BC zwitterionic phototautomer, but to the intramolecular charge transfer, ICT, excited state emissions of the DHB hydrogen bond adducts.

  20. Optimum transfer to a large-amplitude halo orbit for the Solar and Heliospheric Observatory (SOHO) spacecraft

    NASA Technical Reports Server (NTRS)

    Stalos, S.; Folta, D.; Short, B.; Jen, J.; Seacord, A.

    1993-01-01

    The Solar and Heliospheric Observatory (SOHO), built by the European Space Agency to study the Sun as part of the International Solar-Terrestrial Physics (ISTP) Program, will be launched in July 1995 into a transfer trajectory that terminates in a large-amplitude halo orbit. The spacecraft will enter the halo orbit by performing one insertion maneuver at a specified point on the halo orbit. The position on the halo orbit that requires the least fuel for the insertion maneuver is identified using the planar, circular restricted three-body problem as a model. Fuel costs for halo orbit insertion at other points in the orbit are also identified. Practical trajectories incorporating all significant accelerations are discussed. The use of a lunar swingby to avoid any insertion maneuver is mentioned.

  1. Large volume injection in gas chromatography using the through oven transfer adsorption desorption interface operating under vacuum.

    PubMed

    Aragón, Álvaro; Toledano, Rosa M; Gea, Sara; Cortés, José M; Vázquez, Ana M; Villén, Jesús

    2014-06-01

    The present work describes a modification of the Through Oven Transfer Adsorption Desorption (TOTAD) interface, consisting of coupling a vacuum system to reduce the consumption of the helium needed to totally remove the eluent for large volume injection (LVI) in gas chromatography (GC). Two different retention materials in the liner of the TOTAD interface were evaluated: Tenax TA, which was seen to be unsuitable for working under vacuum conditions, and polydimethylsiloxane (PDMS), which provided satisfactory repeatability as well as a good sensitivity. No variability was observed in the retention times in either case. Solutions containing organophosphorous pesticides in two different solvents, a polar (methanol/water) and a non-polar (hexane) solvent, were used to evaluate the modification. The vacuum system coupled to the TOTAD interface allowed up to 90% helium to be saved without affecting the performance. PMID:24725862

  2. A Transparent and Transferable Framework for Tracking Quality Information in Large Datasets

    PubMed Central

    Smith, Derek E.; Metzger, Stefan; Taylor, Jeffrey R.

    2014-01-01

    The ability to evaluate the validity of data is essential to any investigation, and manual “eyes on” assessments of data quality have dominated in the past. Yet, as the size of collected data continues to increase, so does the effort required to assess their quality. This challenge is of particular concern for networks that automate their data collection, and has resulted in the automation of many quality assurance and quality control analyses. Unfortunately, the interpretation of the resulting data quality flags can become quite challenging with large data sets. We have developed a framework to summarize data quality information and facilitate interpretation by the user. Our framework consists of first compiling data quality information and then presenting it through 2 separate mechanisms; a quality report and a quality summary. The quality report presents the results of specific quality analyses as they relate to individual observations, while the quality summary takes a spatial or temporal aggregate of each quality analysis and provides a summary of the results. Included in the quality summary is a final quality flag, which further condenses data quality information to assess whether a data product is valid or not. This framework has the added flexibility to allow “eyes on” information on data quality to be incorporated for many data types. Furthermore, this framework can aid problem tracking and resolution, should sensor or system malfunctions arise. PMID:25379884

  3. Algorithms for Efficient Computation of Transfer Functions for Large Order Flexible Systems

    NASA Technical Reports Server (NTRS)

    Maghami, Peiman G.; Giesy, Daniel P.

    1998-01-01

    An efficient and robust computational scheme is given for the calculation of the frequency response function of a large order, flexible system implemented with a linear, time invariant control system. Advantage is taken of the highly structured sparsity of the system matrix of the plant based on a model of the structure using normal mode coordinates. The computational time per frequency point of the new computational scheme is a linear function of system size, a significant improvement over traditional, still-matrix techniques whose computational times per frequency point range from quadratic to cubic functions of system size. This permits the practical frequency domain analysis of systems of much larger order than by traditional, full-matrix techniques. Formulations are given for both open- and closed-loop systems. Numerical examples are presented showing the advantages of the present formulation over traditional approaches, both in speed and in accuracy. Using a model with 703 structural modes, the present method was up to two orders of magnitude faster than a traditional method. The present method generally showed good to excellent accuracy throughout the range of test frequencies, while traditional methods gave adequate accuracy for lower frequencies, but generally deteriorated in performance at higher frequencies with worst case errors being many orders of magnitude times the correct values.

  4. Electron Scattering From High-Momentum Neutrons in Deuterium

    SciTech Connect

    A.V. Klimenko; S.E. Kuhn

    2005-10-12

    We report results from an experiment measuring the semi-inclusive reaction D(e,e'p{sub s}) where the proton p{sub s} is moving at a large angle relative to the momentum transfer. If we assume that the proton was a spectator to the reaction taking place on the neutron in deuterium, the initial state of that neutron can be inferred. This method, known as spectator tagging, can be used to study electron scattering from high-momentum (off-shell) neutrons in deuterium. The data were taken with a 5.765 GeV electron beam on a deuterium target in Jefferson Laboratory's Hall B, using the CLAS detector. A reduced cross section was extracted for different values of final-state missing mass W*, backward proton momentum {rvec p}{sub s} and momentum transfer Q{sup 2}. The data are compared to a simple PWIA spectator model. A strong enhancement in the data observed at transverse kinematics is not reproduced by the PWIA model. This enhancement can likely be associated with the contribution of final state interactions (FSI) that were not incorporated into the model. A ''bound neutron structure function'' F{sub 2n}{sup eff} was extracted as a function of W* and the scaling variable x* at extreme backward kinematics, where effects of FSI appear to be smaller. For p{sub s} > 400 MeV/c, where the neutron is far off-shell, the model overestimates the value of F{sub 2n}{sup eff} in the region of x* between 0.25 and 0.6. A modification of the bound neutron structure function is one of possible effects that can cause the observed deviation.

  5. Momentum transfer in indirect explosive drive

    SciTech Connect

    Kennedy, J.E.; Warnes, R.H. [Los Alamos National Lab., NM (United States); Cherry, C.R.; Cherry, C.R. Jr.; Fischer, S.H. [Sandia National Labs., Albuquerque, NM (United States)

    1996-07-01

    Material which is not in direct contact with detonating explosives may still be driven by the explosion through impact by driven material or by attachment to driven material. In such circumstances the assumption of inelastic collision permits estimation of the final velocity of an assemblage. Examples of the utility of this assumption are demonstrated through use of Gurney equations. The inelastic collision calculation may also be used for metal parts which are driven by explosives partially covering the metal. We offer a new discounting angle to account for side energy losses from laterally unconfined explosive charges in cases where the detonation wave travels parallel to the surface which is driven.

  6. Nucleon spin structure at low momentum transfers

    SciTech Connect

    Pasechnik, Roman S.; Soffer, Jacques; Teryaev, Oleg V. [High Energy Physics, Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala (Sweden); Physics Department, Temple University, Barton Hall, 1900 N, 13th Street, Philadelphia, Pennsylvania 19122-6082 (United States); Bogoliubov Laboratory of Theoretical Physics, JINR, Dubna 141980 (Russian Federation)

    2010-10-01

    The generalized Gerasimov-Drell-Hearn sum rule is known to be very sensitive to QCD radiative and power corrections. We improve the previously developed QCD-inspired model for the Q{sup 2} dependence of the Gerasimov-Drell-Hearn sum rule. We take into account higher order radiative and higher-twist power corrections extracted from precise Jefferson Lab data on the lowest moment of the spin-dependent proton structure function {Gamma}{sub 1}{sup p}(Q{sup 2}) and on the Bjorken sum rule {Gamma}{sub 1}{sup p-n}(Q{sup 2}). By using the singularity-free analytic perturbation theory we demonstrate that the matching point between chiral-like positive-Q{sup 2} expansion and QCD operator product 1/Q{sup 2} expansion for the nucleon spin sum rules can be shifted down to rather low Q{approx_equal}{Lambda}{sub QCD} leading to a good description of recent proton, neutron, deuteron, and Bjorken sum rule data at all accessible Q{sup 2}.

  7. Nucleon spin structure at low momentum transfers

    NASA Astrophysics Data System (ADS)

    Pasechnik, Roman S.; Soffer, Jacques; Teryaev, Oleg V.

    2010-10-01

    The generalized Gerasimov-Drell-Hearn sum rule is known to be very sensitive to QCD radiative and power corrections. We improve the previously developed QCD-inspired model for the Q2 dependence of the Gerasimov-Drell-Hearn sum rule. We take into account higher order radiative and higher-twist power corrections extracted from precise Jefferson Lab data on the lowest moment of the spin-dependent proton structure function ?1p(Q2) and on the Bjorken sum rule ?1p-n(Q2). By using the singularity-free analytic perturbation theory we demonstrate that the matching point between chiral-like positive-Q2 expansion and QCD operator product 1/Q2 expansion for the nucleon spin sum rules can be shifted down to rather low Q??QCD leading to a good description of recent proton, neutron, deuteron, and Bjorken sum rule data at all accessible Q2.

  8. TDRSS momentum unload planning

    NASA Technical Reports Server (NTRS)

    Cross, George R.; Potter, Mitchell A.; Whitehead, J. Douglass; Smith, James T.

    1991-01-01

    A knowledge-based system is described which monitors TDRSS telemetry for problems in the momentum unload procedure. The system displays TDRSS telemetry and commands in real time via X-windows. The system constructs a momentum unload plan which agrees with the preferences of the attitude control specialists and the momentum growth characteristics of the individual spacecraft. During the execution of the plan, the system monitors the progress of the procedure and watches for unexpected problems.

  9. Measurement of a Mass Transfer Boundary Layer

    Microsoft Academic Search

    P. E. Doe

    1967-01-01

    DATA on momentum transfer from velocity measurements are usually applied to mass transfer processes using the accepted analogies between heat, mass and momentum transfer1. Doubts about these analogies, in particular their application to turbulent flow, have led me to develop a method of measuring the wet bulb depression of water vapour in a mass transfer boundary layer formed by water

  10. scAAV-Mediated Gene Transfer of Interleukin 1-Receptor Antagonist to Synovium and Articular Cartilage in Large Mammalian Joints

    PubMed Central

    Watson, Rachael S.; Broome, Ted A.; Levings, Padraic P.; Rice, Bret L.; Kay, Jesse D.; Smith, Andrew D.; Gouze, Elvire; Gouze, Jean-Noel; Dacanay, E. Anthony; Hauswirth, William W.; Nickerson, David M.; Dark, Michael J.; Colahan, Patrick T.; Ghivizzani, Steven C.

    2012-01-01

    With the long-term goal of developing a gene-based treatment for osteoarthritis (OA), we performed studies to evaluate the equine joint as a model for AAV-mediated gene transfer to large, weight-bearing human joints. A self-complementary AAV2 vector containing the coding regions for human interleukin-1 receptor antagonist (hIL-1Ra) or green fluorescent protein (GFP) was packaged in AAV capsid serotypes 1, 2, 5, 8 and 9. Following infection of human and equine synovial fibroblasts in culture, we found that both were only receptive to transduction with AAV1, 2 and 5. For these serotypes, however, transgene expression from the equine cells was consistently at least 10-fold higher. Analyses of AAV surface receptor molecules and intracellular trafficking of vector genomes implicate enhanced viral uptake by the equine cells. Following delivery of 1 × 1011 vector genomes of serotypes 2, 5 and 8 into the forelimb joints of the horse, all three enabled hIL-1Ra expression at biologically relevant levels and effectively transduced the same cell types, primarily synovial fibroblasts and, to a lesser degree, chondrocytes in articular cartilage. These results provide optimism that AAV vectors can be effectively adapted for gene delivery to large human joints affected by OA. PMID:23151520

  11. Teleportation of an atomic momentum state

    E-print Network

    Qamar, S.; Zhu, S. Y.; Zubairy, M. Suhail.

    2003-01-01

    . The momentum state that is to be transferred is defined as uCa&5cau1p0&1cbu2p0&, ~1! FIG. 1. Schematic diagram of the quantum controlled-NOT logic gate used for the atomic momentum state teleportation. If p0 is the moment of the incoming atom along the x... of atomic center-of-mass momentum m controlled-NOT gate via atomic scattering in the PACS number~s!: 03.67.2a, 42.50.Ct, 32.80.Qk where u1p0& and u2p0& are the momentum states of the incoming atoms in 6x directions, respectively ~see Fig. 1! and ca...

  12. Growth of wrinkle-free graphene on texture-controlled platinum films and thermal-assisted transfer of large-scale patterned graphene.

    PubMed

    Choi, Jae-Kyung; Kwak, Jinsung; Park, Soon-Dong; Yun, Hyung Duk; Kim, Se-Yang; Jung, Minbok; Kim, Sung Youb; Park, Kibog; Kang, Seoktae; Kim, Sung-Dae; Park, Dong-Yeon; Lee, Dong-Su; Hong, Suk-Kyoung; Shin, Hyung-Joon; Kwon, Soon-Yong

    2015-01-27

    Growth of large-scale patterned, wrinkle-free graphene and the gentle transfer technique without further damage are most important requirements for the practical use of graphene. Here we report the growth of wrinkle-free, strictly uniform monolayer graphene films by chemical vapor deposition on a platinum (Pt) substrate with texture-controlled giant grains and the thermal-assisted transfer of large-scale patterned graphene onto arbitrary substrates. The designed Pt surfaces with limited numbers of grain boundaries and improved surface perfectness as well as small thermal expansion coefficient difference to graphene provide a venue for uniform growth of monolayer graphene with wrinkle-free characteristic. The thermal-assisted transfer technique allows the complete transfer of large-scale patterned graphene films onto arbitrary substrates without any ripples, tears, or folds. The transferred graphene shows high crystalline quality with an average carrier mobility of ?5500 cm(2) V(-1) s(-1) at room temperature. Furthermore, this transfer technique shows a high tolerance to variations in types and morphologies of underlying substrates. PMID:25494828

  13. Optical Pumping of Orbital Angular Momentum of Light in Cold Cesium Atoms

    Microsoft Academic Search

    J. W. R. Tabosa; D. V. Petrov

    1999-01-01

    We present experimental results on the transfer of the orbital angular momentum of light to a system of cold cesium atoms. A nondegenerate four-wave mixing process was used as an indirect tool to observe this transfer. Our experiments show, in particular, that the orbital angular momentum of light can be transferred, via optical pumping in the cold atomic sample, from

  14. Search for supersymmetry in events containing a same-flavour opposite-sign dilepton pair, jets, and large missing transverse momentum in $\\sqrt{s}=8$ TeV $pp$ collisions with the ATLAS detector

    E-print Network

    Aad, Georges; ATLAS Collaboration; Abdallah, Jalal; Abdinov, Ovsat; Aben, Rosemarie; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; ?lvarez Piqueras, Damián; Alviggi, Mariagrazia; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baak, Max; Baas, Alessandra; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Badescu, Elisabeta; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James Baker; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Maurice; Becker, Sebastian; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Janna Katharina; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Bernard, Clare; Bernard, Nathan Rogers; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertsche, Carolyn; Bertsche, David; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bevan, Adrian John; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet

    2015-01-01

    Two searches for supersymmetric particles in final states containing a same-flavour opposite-sign lepton pair, jets and large missing transverse momentum are presented. The proton--proton collision data used in these searches were collected at a centre-of-mass energy $\\sqrt{s}=8$ TeV by the ATLAS detector at the Large Hadron Collider and corresponds to an integrated luminosity of 20.3~fb$^{-1}$. Two leptonic production mechanisms are considered: decays of squarks and gluinos with $Z$ bosons in the final state, resulting in a peak in the dilepton invariant mass distribution around the $Z$-boson mass; and decays of neutralinos (e.g. $\\tilde{\\chi}^{0}_{2} \\rightarrow \\ell^{+}\\ell^{-}\\tilde{\\chi}^{0}_{1}$), resulting in a kinematic endpoint in the dilepton invariant mass distribution. For the former, an excess of events above the expected Standard Model background is observed, with a significance of 3 standard deviations. In the latter case, the data are well-described by the expected Standard Model background. T...

  15. Search for supersymmetry in events with large missing transverse momentum, jets, and at least one tau lepton in 20 fb-1 of = 8 TeV proton-proton collision data with the ATLAS detector

    NASA Astrophysics Data System (ADS)

    Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Alimonti, G.; Alio, L.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Almond, J.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ashkenazi, A.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Augsten, K.; Aurousseau, M.; Avolio, G.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Baas, A.; Bacci, C.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Backus Mayes, J.; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J. T.; Baker, O. K.; Balek, P.; Balli, F.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Bartsch, V.; Bassalat, A.; Basye, A.; Bates, R. L.; Batley, J. R.; Battaglia, M.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, K.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Beringer, J.; Bernard, C.; Bernat, P.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertsche, C.; Bertsche, D.; Besana, M. I.; Besjes, G. J.; Bessidskaia, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; Bilbao De Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boddy, C. R.; Boehler, M.; Boek, T. T.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Borri, M.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Brendlinger, K.; Brennan, A. J.; Brenner, R.; Bressler, S.; Bristow, K.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Brown, J.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Bryngemark, L.; Buanes, T.; Buat, Q.; Bucci, F.

    2014-09-01

    A search for supersymmetry (SUSY) in events with large missing transverse momentum, jets, at least one hadronically decaying tau lepton and zero or one additional light leptons (electron/muon), has been performed using 20.3fb-1 of proton-proton collision data at = 8 TeV recorded with the ATLAS detector at the Large Hadron Collider. No excess above the Standard Model background expectation is observed in the various signal regions and 95% confidence level upper limits on the visible cross section for new phenomena are set. The results of the analysis are interpreted in several SUSY scenarios, significantly extending previous limits obtained in the same final states. In the framework of minimal gauge-mediated SUSY breaking models, values of the SUSY breaking scale ? below 63 TeV are excluded, independently of tan ?. Exclusion limits are also derived for an mSUGRA/CMSSM model, in both the R-parity-conserving and R-parity-violating case. A further interpretation is presented in a framework of natural gauge mediation, in which the gluino is assumed to be the only light coloured sparticle and gluino masses below 1090 GeV are excluded. [Figure not available: see fulltext.

  16. Search for supersymmetry in events with large missing transverse momentum, jets, and at least one tau lepton in 20 fb$^{-1}$ of $\\sqrt{s}$=8 TeV proton-proton collision data with the ATLAS detector

    E-print Network

    ATLAS Collaboration

    2014-10-22

    A search for supersymmetry (SUSY) in events with large missing transverse momentum, jets, at least one hadronically decaying tau lepton and zero or one additional light leptons (electron/muon), has been performed using 20.3 fb$^{-1}$ of proton-proton collision data at $\\sqrt{s} = 8$ TeV recorded with the ATLAS detector at the Large Hadron Collider. No excess above the Standard Model background expectation is observed in the various signal regions and 95% confidence level upper limits on the visible cross section for new phenomena are set. The results of the analysis are interpreted in several SUSY scenarios, significantly extending previous limits obtained in the same final states. In the framework of minimal gauge-mediated SUSY breaking models, values of the SUSY breaking scale $\\Lambda$ below 63 TeV are excluded, independently of tan$\\beta$. Exclusion limits are also derived for an mSUGRA/CMSSM model, in both the R-parity-conserving and R-parity-violating case. A further interpretation is presented in a framework of natural gauge mediation, in which the gluino is assumed to be the only light coloured sparticle and gluino masses below 1090 GeV are excluded.

  17. Conservation of Momentum 1

    NSDL National Science Digital Library

    Michael Horton

    2009-05-30

    This lab introduces students to the idea of recoil and how conservation of momentum can be used to explain it. Many people use action/reaction to explain recoil, but conservation of momentum can be used equally well. Before shooting a gun, there is zero m

  18. Introducing Conservation of Momentum

    ERIC Educational Resources Information Center

    Brunt, Marjorie; Brunt, Geoff

    2013-01-01

    The teaching of the principle of conservation of linear momentum is considered (ages 15 + ). From the principle, the momenta of two masses in an isolated system are considered. Sketch graphs of the momenta make Newton's laws appear obvious. Examples using different collision conditions are considered. Conservation of momentum is considered…

  19. Measuring the Orbital Angular Momentum of a Single Photon

    Microsoft Academic Search

    Jonathan Leach; Miles J. Padgett; Stephen M. Barnett; Sonja Franke-Arnold; Johannes Courtial

    2002-01-01

    We propose an interferometric method for measuring the orbital angular momentum of single photons. We demonstrate its viability by sorting four different orbital angular momentum states, and are thus able to encode two bits of information on a single photon. This new approach has implications for entanglement experiments, quantum cryptography and high density information transfer.

  20. Conservation of Orbital Angular Momentum in Stimulated Down-Conversion

    E-print Network

    D. P. Caetano; M. P. Almeida; P. H. Souto Ribeiro; J. A. O. Huguenin; B. Coutinho dos Santos; A. Z. Khoury

    2001-08-22

    We report on an experiment demonstrating the conservation of orbital angular momentum in stimulated down-conversion. The orbital angular momentum is not transferred to the individual beams of the spontaneous down-conversion, but it is conserved when twin photons are taken individually. We observe the conservation law for an individual beam of the down-conversion through cavity-free stimulated emission.

  1. Orbital angular momentum of a high order Bessel light beam

    Microsoft Academic Search

    V. Garces-Chavez; J. Arlt; K. Dholakia; K. Volke-Sepulveda; S. Chavez-Cerda

    2002-01-01

    Summary form only given. We demonstrate experimentally for the first time, that a high order Bessel beam possesses orbital angular momentum (OAM). We demonstrate transfer of OAM from such a beam to trapped transparent particles in optical tweezers. Additionally, we examine theoretically, within a rigorous vectorial treatment, the local angular momentum density for a high order Bessel beam (HOBB) and

  2. Specific Angular Momentum of Extrasolar Planetary Systems

    E-print Network

    John C. Armstrong; Shane L. Larson; Rhett R. Zollinger

    2011-09-02

    As the number of known planetary systems increases, the ability to follow-up and characterize the extent of any system becomes limited. This paper considers the use of specific angular momentum as a metric to prioritize future observations. We analyze 431 planets in 367 known extrasolar planetary systems from Butler et al. (2006) (including updates to their online catalog, current to April, 2011) and estimate each system's orbital angular momentum. The range of partition- ing of specific angular momentum in these systems is found to be large, spanning several orders of magnitude. The analysis shows that multi-planet systems tend to have the highest values of specific angular momentum normalized against the planetary masses. This suggests that in high angular momentum systems, the dominant contributors have already been discovered, and that single-planet sys- tems with low observed angular momentum may be the most likely candidates for additional undiscovered companions compared to their high angular momentum, single-planet counterparts. The multi-planet system, GJ 581, is considered as a historical case study to demonstrate the concept, examining how the specific angular momentum of the know planetary system evolved with each discovery.

  3. Transfer and assembly of large area TiO2 nanotube arrays onto conductive glass for dye sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Li, Siqian; Ding, Hao; Li, Quantong; Wang, Baoyuan; Wang, Xina; Wang, Hao

    2014-02-01

    Highly ordered titanium oxide nanotube arrays are synthesized by a two-step anodic oxidation of pure titanium foil at constant voltage. It is found that the length of nanotube arrays firstly increased rapidly with the anodization time, and then the growth rate gradually slowed down with further increasing the anodization time. The mechanism of anodization time-dependent tube length growth is discussed. Large area free-standing TiO2 nanotube (TNT) arrays are detached from the underlying Ti foil and transferred onto the fluorine-doped tin oxide (FTO) conductive glass substrates to serve as the photoanodes of the dye-sensitized solar cells (DSSCs). The photoelectric performance of the DSSCs assembled by TNT/FTO films is strongly related to the tube length of titania and the surface treatment. For the photoanodes without any surface modification, the highest overall photovoltaic conversion efficiency (PCE) that can be achieved is 4.12% in the DSSC assembled with 33-?m-thick TNT arrays, while the overall PCE of DSSC based on the 33-?m-thick TNT arrays increases to 9.02% in response to the treatment with TiCl4.

  4. Angular momentum in the Local Group

    SciTech Connect

    Dunn, A. [Cambridge Univ. (United Kingdom). Inst. of Astronomy; Laflamme, R. [Los Alamos National Lab., NM (United States)

    1994-04-01

    We briefly review models for the Local Group and the acquisition of its angular momentum. We describe early attempts to understand the origin of the spin of the galaxies discussing the hypothesis that the Local Group has little angular momentum. Finally we show that using Peebles` least action principle there should be a rather large amount of orbital angular momentum compared to the magnitude of the spin of its galaxies. Therefore the Local Group cannot be thought as tidally isolated. Using Peebles` trajectories we give a possible set of trajectories for Local Group galaxies which would predict their spin.

  5. A High-yield Two-step Transfer Printing Method for Large-scale Fabrication of Organic Single-crystal Devices on Arbitrary Substrates

    PubMed Central

    Deng, Wei; Zhang, Xiujuan; Pan, Huanhuan; Shang, Qixun; Wang, Jincheng; Zhang, Xiaohong; Zhang, Xiwei; Jie, Jiansheng

    2014-01-01

    Single-crystal organic nanostructures show promising applications in flexible and stretchable electronics, while their applications are impeded by the large incompatibility with the well-developed photolithography techniques. Here we report a novel two-step transfer printing (TTP) method for the construction of organic nanowires (NWs) based devices onto arbitrary substrates. Copper phthalocyanine (CuPc) NWs are first transfer-printed from the growth substrate to the desired receiver substrate by contact-printing (CP) method, and then electrode arrays are transfer-printed onto the resulting receiver substrate by etching-assisted transfer printing (ETP) method. By utilizing a thin copper (Cu) layer as sacrificial layer, microelectrodes fabricated on it via photolithography could be readily transferred to diverse conventional or non-conventional substrates that are not easily accessible before with a high transfer yield of near 100%. The ETP method also exhibits an extremely high flexibility; various electrodes such as Au, Ti, and Al etc. can be transferred, and almost all types of organic devices, such as resistors, Schottky diodes, and field-effect transistors (FETs), can be constructed on planar or complex curvilinear substrates. Significantly, these devices can function properly and exhibit closed or even superior performance than the device counterparts fabricated by conventional approach. PMID:24942458

  6. W Boson production at large transverse momentum.

    E-print Network

    Kidonakis, Nikolaos; Sabio Vera, Agustin

    process of importance in testing the Standard Model and in es- timates of backgrounds to new physics, such as associated Higgs boson production at the Teva- tron. In Refs. [1, 2] the complete next-to-leading-order (NLO) cross section for W hadropro... , Phys. Rev. D 64, 114001 (2001). [7] N. Kidonakis, Int. J. Mod. Phys. A 15, 1245 (2000); Mod. Phys. Lett. A 19, 405 (2004). [8] N. Kidonakis and V. Del Duca, Phys. Lett. B 480, 87 (2000). [9] N. Kidonakis, hep-ph/0303186, Int. J. Mod. Phys. A (in print...

  7. Probing the nucleon at large momentum tramsfer

    E-print Network

    Peter Kroll

    1999-07-12

    The central role of soft nucleon matrix elements in reactions of high energy electrons or real photons with nucleons is emphasized. These soft matrix elements are described in terms of skewed parton distributions. Their connections to ordinary parton distributions, form factors, Compton scattering and hard meson electroproduction is discussed.

  8. Large-scale mass transfers related to pressure solution creep-faulting interactions in mudstones: Driving processes and impact of lithification degree

    NASA Astrophysics Data System (ADS)

    Richard, J.

    2014-02-01

    Where normal faulting is associated with PSC (Pressure Solution Creep), it generates evolutions in petrophysical properties of mudstones like chalk: decrease in reservoir qualities and transport properties in the deformed zones adjacent to the fault plane and increase (or no change) in reservoir qualities and transport properties in the outermost deformed zones. These modifications result from large-scale mass transfers linked to a transport of solutes through the pore space over distances of several grains within decimeter or larger zones (open systems at the grain scale). In the lithified mudstones, these large-scale mass transfers consist in a mass redistribution from the outermost deformed zones (mass and volume loss) to the deformed zones adjacent to the fault planes (mass gain). In the weakly lithified mudstones, the mass redistribution occurs in an opposite direction. A deeper understanding of these large-scale mass redistributions is essential because the PSC-faulting interactions and the associated petrophysical modifications can be a key topic in several geological applications (oil and gas migration and entrapment in mudstone reservoirs, anthropogenic waste storage, carbon dioxyde geosequestration). The results of two studies about mass transfers and volume changes induced by natural fault systems in “white chalk” allowed to point out that two driving processes control the large-scale mass transfers during PSC-faulting interactions: the advective mass transport related to pore fluid flows and the large-scale diffusive mass transport linked to chemical potential gradients. The present contribution also highlights that the lithification degree of the host material plays a key role in the large-scale mass transfers related to PSC-faulting interactions by controlling (1) the spatial distribution of voids induced by the deformation, (2) the particle displacement on the fault plane and in the adjacent zones and (3) the petrophysical properties of the host material in some zones.

  9. Search for new phenomena in tt events with large missing transverse momentum in proton-proton collisions at sqrt[s] = 7 TeV with the ATLAS detector.

    PubMed

    Aad, G; Abbott, B; Abdallah, J; Abdelalim, A A; Abdesselam, A; Abdinov, O; Abi, B; Abolins, M; Abramowicz, H; Abreu, H; Acerbi, E; Acharya, B S; Adams, D L; Addy, T N; Adelman, J; Aderholz, M; Adomeit, S; Adragna, P; Adye, T; Aefsky, S; Aguilar-Saavedra, J A; Aharrouche, M; Ahlen, S P; Ahles, F; Ahmad, A; Ahsan, M; Aielli, G; Akdogan, T; Akesson, T P A; Akimoto, G; Akimov, A V; Akiyama, A; Alam, M S; Alam, M A; Albert, J; Albrand, S; Aleksa, M; Aleksandrov, I N; Alessandria, F; Alexa, C; Alexander, G; Alexandre, G; Alexopoulos, T; Alhroob, M; Aliev, M; Alimonti, G; Alison, J; Aliyev, M; Allport, P P; Allwood-Spiers, S E; Almond, J; Aloisio, A; Alon, R; Alonso, A; Alviggi, M G; Amako, K; Amaral, P; Amelung, C; Ammosov, V V; Amorim, A; Amorós, G; Amram, N; Anastopoulos, C; Ancu, L S; Andari, N; Andeen, T; Anders, C F; Anders, G; Anderson, K J; Andreazza, A; Andrei, V; Andrieux, M-L; Anduaga, X S; Angerami, A; Anghinolfi, F; Anjos, N; Annovi, A; Antonaki, A; Antonelli, M; Antonov, A; Antos, J; Anulli, F; Aoun, S; Aperio Bella, L; Apolle, R; Arabidze, G; Aracena, I; Arai, Y; Arce, A T H; Archambault, J P; Arfaoui, S; Arguin, J-F; Arik, E; Arik, M; Armbruster, A J; Arnaez, O; Arnault, C; Artamonov, A; Artoni, G; Arutinov, D; Asai, S; Asfandiyarov, R; Ask, S; Asman, B; Asquith, L; Assamagan, K; Astbury, A; Astvatsatourov, A; Atoian, G; Aubert, B; Auge, E; Augsten, K; Aurousseau, M; Austin, N; Avolio, G; Avramidou, R; Axen, D; Ay, C; Azuelos, G; Azuma, Y; Baak, M A; Baccaglioni, G; Bacci, C; Bach, A M; Bachacou, H; Bachas, K; Bachy, G; Backes, M; Backhaus, M; Badescu, E; Bagnaia, P; Bahinipati, S; Bai, Y; Bailey, D C; Bain, T; Baines, J T; Baker, O K; Baker, M D; Baker, S; Banas, E; Banerjee, P; Banerjee, Sw; Banfi, D; Bangert, A; Bansal, V; Bansil, H S; Barak, L; Baranov, S P; Barashkou, A; Barbaro Galtieri, A; Barber, T; Barberio, E L; Barberis, D; Barbero, M; Bardin, D Y; Barillari, T; Barisonzi, M; Barklow, T; Barlow, N; Barnett, B M; Barnett, R M; Baroncelli, A; Barone, G; Barr, A J; Barreiro, F; Barreiro Guimarães da Costa, J; Barrillon, P; Bartoldus, R; Barton, A E; Bartsch, D; Bartsch, V; Bates, R L; Batkova, L; Batley, J R; Battaglia, A; Battistin, M; Battistoni, G; Bauer, F; Bawa, H S; Beare, B; Beau, T; Beauchemin, P H; Beccherle, R; Bechtle, P; Beck, H P; Beckingham, M; Becks, K H; Beddall, A J; Beddall, A; Bedikian, S; Bednyakov, V A; Bee, C P; Begel, M; Behar Harpaz, S; Behera, P K; Beimforde, M; Belanger-Champagne, C; Bell, P J; Bell, W H; Bella, G; Bellagamba, L; Bellina, F; Bellomo, M; Belloni, A; Beloborodova, O; Belotskiy, K; Beltramello, O; Ben Ami, S; Benary, O; Benchekroun, D; Benchouk, C; Bendel, M; Benekos, N; Benhammou, Y; Benjamin, D P; Benoit, M; Bensinger, J R; Benslama, K; Bentvelsen, S; Berge, D; Bergeaas Kuutmann, E; Berger, N; Berghaus, F; Berglund, E; Beringer, J; Bernardet, K; Bernat, P; Bernhard, R; Bernius, C; Berry, T; Bertin, A; Bertinelli, F; Bertolucci, F; Besana, M I; Besson, N; Bethke, S; Bhimji, W; Bianchi, R M; Bianco, M; Biebel, O; Bieniek, S P; Bierwagen, K; Biesiada, J; Biglietti, M; Bilokon, H; Bindi, M; Binet, S; Bingul, A; Bini, C; Biscarat, C; Bitenc, U; Black, K M; Blair, R E; Blanchard, J-B; Blanchot, G; Blazek, T; Blocker, C; Blocki, J; Blondel, A; Blum, W; Blumenschein, U; Bobbink, G J; Bobrovnikov, V B; Bocchetta, S S; Bocci, A; Boddy, C R; Boehler, M; Boek, J; Boelaert, N; Böser, S; Bogaerts, J A; Bogdanchikov, A; Bogouch, A; Bohm, C; Boisvert, V; Bold, T; Boldea, V; Bolnet, N M; Bona, M; Bondarenko, V G; Bondioli, M; Boonekamp, M; Boorman, G; Booth, C N; Bordoni, S; Borer, C; Borisov, A; Borissov, G; Borjanovic, I; Borroni, S; Bos, K; Boscherini, D; Bosman, M; Boterenbrood, H; Botterill, D; Bouchami, J; Boudreau, J; Bouhova-Thacker, E V; Bourdarios, C; Bousson, N; Boveia, A; Boyd, J; Boyko, I R; Bozhko, N I; Bozovic-Jelisavcic, I; Bracinik, J; Braem, A; Branchini, P; Brandenburg, G W; Brandt, A; Brandt, G; Brandt, O; Bratzler, U; Brau, B; Brau, J E; Braun, H M; Brelier, B; Bremer, J; Brenner, R; Bressler, S; Breton, D; Britton, D; Brochu, F M; Brock, I; Brock, R; Brodbeck, T J; Brodet, E; Broggi, F; Bromberg, C; Brooijmans, G; Brooks, W K; Brown, G; Brown, H; Bruckman de Renstrom, P A; Bruncko, D; Bruneliere, R; Brunet, S; Bruni, A; Bruni, G; Bruschi, M; Buanes, T; Bucci, F; Buchanan, J; Buchanan, N J; Buchholz, P; Buckingham, R M; Buckley, A G; Buda, S I; Budagov, I A; Budick, B; Büscher, V; Bugge, L; Buira-Clark, D; Bulekov, O; Bunse, M; Buran, T; Burckhart, H; Burdin, S; Burgess, T; Burke, S; Busato, E; Bussey, P; Buszello, C P; Butin, F; Butler, B; Butler, J M; Buttar, C M; Butterworth, J M; Buttinger, W; Cabrera Urbán, S; Caforio, D; Cakir, O; Calafiura, P; Calderini, G; Calfayan, P; Calkins, R; Caloba, L P; Caloi, R; Calvet, D; Calvet, S; Camacho Toro, R; Camarri, P; Cambiaghi, M; Cameron, D; Campana, S

    2012-01-27

    A search for new phenomena in tt events with large missing transverse momentum in proton-proton collisions at a center-of-mass energy of 7 TeV is presented. The measurement is based on 1.04 fb(-1) of data collected with the ATLAS detector at the LHC. Contributions to this final state may arise from a number of standard model extensions. The results are interpreted in terms of a model where new top-quark partners are pair produced and each decay to an on-shell top (or antitop) quark and a long-lived undetected neutral particle. The data are found to be consistent with standard model expectations. A limit at 95% confidence level is set excluding a cross section times branching ratio of 1.1 pb for a top-partner mass of 420 GeV and a neutral particle mass less than 10 GeV. In a model of exotic fourth generation quarks, top-partner masses are excluded up to 420 GeV and neutral particle masses up to 140 GeV. PMID:22400827

  10. Engineering Momentum spring 2014

    E-print Network

    Subramanian, Venkat

    News 28 >> Faculty News 33 >> The Last Word 1 12 24 2016 4 6 signs of spring The cherry blossomsEngineering Momentum spring 2014 ac r o s s di s ci p l i n e s . ac r o s s t h e w o r l d. Sommerer #12;spring 2014 > Engineering Momentum 1 Contents dean Ralph Quatrano, PhD associate dean

  11. Electron Scattering From a High-Momentum Neutron in Deuterium

    SciTech Connect

    Alexei Klimenko

    2004-05-01

    The deuterium nucleus is a system of two nucleons (proton and neutron) bound together. The configuration of the system is described by a quantum-mechanical wave function and the state of the nucleons at a given time is not know a priori. However, by detecting a backward going proton of moderate momentum in coincidence with a reaction taking place on the neutron in deuterium, the initial state of that neutron can be inferred if we assume that the proton was a spectator to the reaction. This method, known as spectator tagging, was used to study the electron scattering from high-momentum neutrons in deuterium. The data were taken with a 5.765 GeV polarized electron beam on a deuterium target in Jefferson Laboratory's Hall B, using the CLAS detector. The accumulated data cover a wide kinematic range, reaching values of the invariant mass of the unobserved final state W* up to 3 GeV. A data sample of approximately 5 - 10{sup 5} events, with protons detected at large scattering angles (as high as 136 degrees) in coincidence with the forward electrons, was selected. The product of the neutron structure function with the initial nucleon momentum distribution F{sub 2n}. S was extracted for different values of W*, backward proton momenta p{sub s} and momentum transfer Q{sup 2}. The data were compared to a calculation based on the spectator approximation and using the free nucleon form factors and structure functions. A strong enhancement in the data, not reproduced by the model, was observed at cos(theta{sub pq}) > -0.3 (where theta{sub pq} is the proton scattering angle relative to the direction of the momentum transfer) and can be associated with the contribution of final state interactions (FSI) that were not incorporated into the model. The bound nucleon structure function F{sub 2n} was studied in the region cos(theta{sub pq}) < -0.3 as a function of W* and scaling variable x*. At high spectator proton momenta the struck neutron is far off its mass shell. At p{sub s} > 400 MeV/c, the model overestimate s the value of F{sub 2n} in the region of x* between 0.25 and 0.6. A modification of the bound neutron structure is one of the possible effects that can cause the observed deviation.

  12. Momentum-space Argonne V18 interaction

    SciTech Connect

    Veerasamy, S.; Polyzou, W. N. [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States)

    2011-09-15

    This paper gives a momentum-space representation of the Argonne V18 potential as an expansion in products of spin-isospin operators with scalar coefficient functions of the momentum transfer. Two representations of the scalar coefficient functions for the strong part of the interaction are given. One is as an expansion in an orthonormal basis of rational functions and the other as an expansion in Chebyshev polynomials on different intervals. Both provide practical and efficient representations for computing the momentum-space potential that do not require integration or interpolation. Programs based on both expansions are available as supplementary material. Analytic expressions are given for the scalar coefficient functions of the Fourier transform of the electromagnetic part of the Argonne V18. A simple method for computing the partial-wave projections of these interactions from the operator expressions is also given.

  13. Transverse momentum distributions and nuclear effects

    NASA Astrophysics Data System (ADS)

    Pace, Emanuele; Del Dotto, Alessio; Kaptari, Leonid; Rinaldi, Matteo; Salmè, Giovanni; Scopetta, Sergio

    2015-01-01

    A distorted spin-dependent spectral function for 3He is considered to take care of the final state interaction in the extraction of the quark transverse-momentum distributions in the neutron from semi-inclusive deep inelastic electron scattering off polarized 3He at finite momentum transfers. The generalization of the analysis in a Poincaré covariant framework within the light-front dynamics is outlined. The definition of the light-front spin-dependent spectral function for a J=1/2 system, as the nucleon, allows us to show that within the light-front dynamics and in the valence approximation only three of the six leading twist T-even transverse-momentum distributions are independent.

  14. The effects of inlet turbulence and rotor/stator interactions on the aerodynamics and heat transfer of a large-scale rotating turbine model. Volume 2: Heat transfer data tabulation. 15 percent axial spacing

    NASA Technical Reports Server (NTRS)

    Dring, R. P.; Blair, M. F.; Joslyn, H. D.

    1986-01-01

    A combined experimental and analytical program was conducted to examine the effects of inlet turbulence on airfoil heat transfer. The experimental portion of the study was conducted in a large-scale (approx 5X engine), ambient temperature, rotating turbine model configured in both single stage and stage-and-a-half arrangements. Heat transfer measurements were obtained using low-conductivity airfoils with miniature thermcouples welded to a thin, electrically heated surface skin. Heat transfer data were acquired for various combinations of low or high inlet turbulence intensity, flow coefficient, first-stator/rotor axial spacing, Reynolds number and relative circumferential position of the first and second stators. Aerodynamic measurements obtained as part of the program include distributions of the mean and fluctuating velocities at the turbine inlet and, for each airfoil row, midspan airfoil surface pressures and circumferential distributions of the downstream steady state pressures and fluctuating velocities. Analytical results include airfoil heat transfer predictions produced using existing 2-D boundary layer computation schemes and an examination of solutions of the unsteady boundary layer equations. The results are reported in four separate volumes, of which this is Volume 2: Heat Transfer Data Tabulation; 15 Percent Axial Spacing.

  15. The Angular Momentum Dichotomy

    NASA Astrophysics Data System (ADS)

    Teklu, Adelheid; Remus, Rhea-Silvia; Dolag, Klaus; Burkert, Andreas

    2015-02-01

    In the context of the formation of spiral galaxies the evolution and distribution of the angular momentum of dark matter halos have been discussed for more than 20 years, especially the idea that the specific angular momentum of the halo can be estimated from the specific angular momentum of its disk (e.g. Fall & Efstathiou (1980), Fall (1983) and Mo et al. (1998)). We use a new set of hydrodynamic cosmological simulations called Magneticum Pathfinder which allow us to split the galaxies into spheroidal and disk galaxies via the circularity parameter ?, as commonly used (e.g. Scannapieco et al. (2008)). Here, we focus on the dimensionless spin parameter ? = J |E|1/2 / (G M5/2) (Peebles 1969, 1971), which is a measure of the rotation of the total halo and can be fitted by a lognormal distribution, e.g. Mo et al. (1998). The spin parameter allows one to compare the relative angular momentum of halos across different masses and different times. Fig. 1 reveals a dichotomy in the distribution of ? at all redshifts when the galaxies are split into spheroids (dashed) and disk galaxies (dash-dotted). The disk galaxies preferentially live in halos with slightly larger spin parameter compared to spheroidal galaxies. Thus, we see that the ? of the whole halo reflects the morphology of its central galaxy. For more details and a larger study of the angular momentum properties of disk and spheroidal galaxies, see Teklu et al. (in prep.).

  16. Reaction/Momentum Wheel

    NASA Technical Reports Server (NTRS)

    1997-01-01

    CTA Space Systems, Inc. has been licensed to sell commercially a reaction/momentum wheel originally developed for NASA's scientific satellites. NASA originally identified a need for the wheel in its Small Explorer program. The Submillimeter Wave Astronomy Satellite required extremely low jitter and a reaction/momentum wheel with a torque greater than any comparably sized commercially available wheel to keep the instrument pointed at celestial objects to a high degree of precision. After development, a market assessment by Research Triangle Institute was completed, showing commercial potential for the flywheel technology. A license was granted to CTA in the fall of 1996. The company currently uses the technology in its complete spacecraft fabrication services and has built over 10 reaction/momentum wheels for commercial, scientific, and military customers.

  17. The effects of Reynolds number, rotor incidence angle and surface roughness on the heat transfer distribution in a large-scale turbine rotor passage

    NASA Technical Reports Server (NTRS)

    Blair, M. F.

    1991-01-01

    A combined experimental and computational program was conducted to examine the heat transfer distribution in a turbine rotor passage geometrically similar to the Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump (HPFTP). Heat transfer was measured and computed for both the full span suction and pressure surfaces of the rotor airfoil as well as for the hub endwall surface. The objective of the program was to provide a benchmark-quality database for the assessment of rotor heat transfer computational techniques. The experimental portion of the study was conducted in a large scale, ambient temperature, rotating turbine model. The computational portion consisted of the application of a well-posed parabolized Navier-Stokes analysis of the calculation of the three-dimensional viscous flow through ducts simulating a gas turbine package. The results of this assessment indicate that the procedure has the potential to predict the aerodynamics and the heat transfer in a gas turbine passage and can be used to develop detailed three dimensional turbulence models for the prediction of skin friction and heat transfer in complex three dimensional flow passages.

  18. Ideal Linear Chain Polymers with Fixed Angular Momentum

    E-print Network

    Matthew Brunner; J. M. Deutsch

    2010-08-21

    The statistical mechanics of a linear non-interacting polymer chain with a large number of monomers is considered with fixed angular momentum. The radius of gyration for a linear polymer is derived exactly by functional integration. This result is then compared to simulations done with a large number of non-interacting rigid links at fixed angular momentum. The simulation agrees with the theory up to finite size corrections. The simulations are also used to investigate the anisotropic nature of a spinning polymer. We find universal scaling of the polymer size along the direction of the angular momentum, as a function of rescaled angular momentum.

  19. Transfer involving deformed nuclei

    SciTech Connect

    Rasmussen, J.O.; Guidry, M.W.; Canto, L.F.

    1985-03-01

    Results are reviewed of 1- and 2-neutron transfer reactions at near-barrier energies for deformed nuclei. Rotational angular momentum and excitation patterns are examined. A strong tendency to populating high spin states within a few MeV of the yrast line is noted, and it is interpreted as preferential transfer to rotation-aligned states. 16 refs., 12 figs.

  20. Induced Angular Momentum

    ERIC Educational Resources Information Center

    Parker, G. W.

    1978-01-01

    Discusses, classically and quantum mechanically, the angular momentum induced in the bound motion of an electron by an external magnetic field. Calculates the current density and its magnetic moment, and then uses two methods to solve the first-order perturbation theory equation for the required eigenfunction. (Author/GA)

  1. The momentum map representation of images

    E-print Network

    M. Bruveris; F. Gay-Balmaz; D. D. Holm; T. S. Ratiu

    2009-12-16

    This paper discusses the mathematical framework for designing methods of large deformation matching (LDM) for image registration in computational anatomy. After reviewing the geometrical framework of LDM image registration methods, a theorem is proved showing that these methods may be designed by using the actions of diffeomorphisms on the image data structure to define their associated momentum representations as (cotangent lift) momentum maps. To illustrate its use, the momentum map theorem is shown to recover the known algorithms for matching landmarks, scalar images and vector fields. After briefly discussing the use of this approach for Diffusion Tensor (DT) images, we explain how to use momentum maps in the design of registration algorithms for more general data structures. For example, we extend our methods to determine the corresponding momentum map for registration using semidirect product groups, for the purpose of matching images at two different length scales. Finally, we discuss the use of momentum maps in the design of image registration algorithms when the image data is defined on manifolds instead of vector spaces.

  2. The momentum map representation of images

    E-print Network

    M. Bruveris; F. Gay-Balmaz; D. D. Holm; T. S. Ratiu

    2015-04-08

    This paper discusses the mathematical framework for designing methods of large deformation matching (LDM) for image registration in computational anatomy. After reviewing the geometrical framework of LDM image registration methods, a theorem is proved showing that these methods may be designed by using the actions of diffeomorphisms on the image data structure to define their associated momentum representations as (cotangent lift) momentum maps. To illustrate its use, the momentum map theorem is shown to recover the known algorithms for matching landmarks, scalar images and vector fields. After briefly discussing the use of this approach for Diffusion Tensor (DT) images, we explain how to use momentum maps in the design of registration algorithms for more general data structures. For example, we extend our methods to determine the corresponding momentum map for registration using semidirect product groups, for the purpose of matching images at two different length scales. Finally, we discuss the use of momentum maps in the design of image registration algorithms when the image data is defined on manifolds instead of vector spaces.

  3. Radiofrequency plasma assisted exfoliation and reduction of large-area graphene oxide platelets produced by a mechanical transfer process

    Microsoft Academic Search

    Marta Cardinali; Luca Valentini; Paola Fabbri; Josè M. Kenny

    2011-01-01

    We present a method to produce extended few layer flakes of reduced graphene oxide starting from bulk graphene oxide platelets using Ar plasma treatment at room temperature of mechanically exfoliated platelets. Multilayer graphene oxide platelets transferred to a silicon wafer by micromechanical cleavage were thinned in a controllable and reproducible way by plasma treatment to achieve few-layer reduced graphene sheets

  4. Heavy Flavor in Medium Momentum Evolution: Langevin vs Boltzmann

    E-print Network

    Santosh K. Das; Francesco Scardina; Salvatore Plumari; Vincenzo Greco

    2014-09-19

    The propagation of heavy quarks in the quark-gluon plasma (QGP) has been often treated within the framework of the Langevin equation (LV), i.e. assuming the momentum transfer is small or the scatterings are sufficiently forward peaked, small screening mass $m_D$. We address a direct comparison between the Langevin dynamics and the Boltzmann collisional integral (BM) when a bulk medium is in equilibrium at fixed temperature. We show that unless the cross section is quite forward peaked ($m_D\\cong T $) or the mass to temperature ratio is quite large ($M_{HQ}/T \\gtrsim 8-10$) there are significant differences in the evolution of the $p-$spectra and consequently on nuclear modification factor $R_{AA}(p_T)$. However for charm quark we find that very similar $R_{AA}(p_T)$ between the LV and BM can be obtained, but with a modified diffusion coefficient by about $\\sim 15-50\\%$ depending on the angular dependence of the cross section which regulates the momentum transfer. Studying also the momentum spread suffered by a single heavy quarks we see that at temperatures $T\\gtrsim \\, 250\\,\\rm MeV$ the dynamics of the scatterings is far from being of Brownian type for charm quarks. In the case of bottom quarks we essentially find no differences in the time evolution of the momentum spectra between the LV and the BM dynamics independently of the angular dependence of the cross section, at least in the range of temperature relevant for ultra-relativistic heavy-ion collisions. Finally, we have shown the possible impact of this study on $R_{AA}(p_T)$ and $v_2(p_T)$ for a realistic simulation of relativistic HIC. For larger $m_D$ the elliptic flow can be about $50\\%$ larger for the Boltzmann dynamics with respect to the Langevin. This is helpful for a simultaneous reproduction of $R_{AA}(p_T)$ and $v_2(p_T)$.

  5. Target excitation and angular momentum transfer in reactions of E \\/ A =11. 9 MeV sup 28 Si with sup 181 Ta from 4. pi. charged particle, neutron, and. gamma. -ray multiplicity measurements

    Microsoft Academic Search

    Z. Majka; V. Abenante; Z. Li; N. G. Nicolis; D. G. Sarantites; T. M. Semkow; L. G. Sobotka; D. W. Stracener; J. R. Beene; D. C. Hensley; H. C. Griffin

    1989-01-01

    The conversion of kinetic energy into target-like fragment excitation and orbital angular momentum into fragment spin has been studied in the reaction 333 MeV ²⁸Si with ¹⁸¹Ta. The light charged particles were detected in a small, highly segmented, 4Ï phoswich detector system placed in the spin spectrometer, a 4Ï NaI array which served as a neutron and gamma detector. Multiplicities

  6. Ion energy/momentum effects during ion assisted growth of niobium nitride films

    NASA Astrophysics Data System (ADS)

    Klingenberg, Melissa L.

    The research described herein was performed to better understand and discern ion energy vs. ion momentum effects during ion beam assisted (IBAD) film growth and their effects on residual stress, crystalline structure, morphology, and composition, which influence film tribological properties. NbxN y was chosen for this research because it is a refractory material that can possess a large number of crystalline structures, and it has been found to have good tribological properties. To separate the effects of momentum transfer per arriving atom (p/a), which considers bombarding species mass, energy, and ion-to-atom transport ratio, from those of energy deposition per arriving atom (E/a), a mass independent parameter, different inert ion beams (krypton, argon, and neon) were used to create a matrix of coatings formed using similar energy deposition, but different momentum transfer and vice versa. Deposition was conducted in a research-scale IBAD system using electron beam evaporation, a radio frequency ion source, and a neutral nitrogen gas backfill. Films were characterized using x-ray diffraction, atomic force microscopy, Rutherford backscattering spectrometry, and residual stress analysis. Direct and quantifiable effects of bombardment were observed; however, energy deposition and momentum transfer effects could not be completely separated, confirming that thin film processes are complex. Complexities arose from ion-specific interactions (ion size, recoil energy, per cent reflected neutrals, Penning ionization, etc.) and chemistry effects that are not considered by the simple models. Overall, it can be stated that bombardment promoted nitride formation, nanocrystallinity, and compressive stress formation; influenced morphology (which influenced post-deposition oxygen uptake) and stress evolution; increased lattice parameter; modified crystalline phase and texture; and led to inert gas incorporation. High stress levels correlated strongly with material disorder and closed-structured morphologies.

  7. Orbital angular momentum in triatomic molecules

    Microsoft Academic Search

    Ch. Jungen; A. J. Merer

    1980-01-01

    A general method is described for calculating the vibronic energy levels associated with two Born-Oppenheimer states of a triatomic molecule that become degenerate in the linear limit. The method combines Renner's matrix treatment of orbital angular momentum in linear molecules with Hougen, Bunker and Johns' formalism for large amplitude bending motions, and allows for the effects of electron spins; it

  8. Obama Team's Advocacy Boosts Charter Momentum

    ERIC Educational Resources Information Center

    Maxwell, Lesli A.

    2009-01-01

    President Barack Obama and U.S. Secretary of Education Arne Duncan have been championing charter schools for months, creating what some advocates believe is the most forceful national momentum to expand the largely independent public schools since the first charter opened nearly 20 years ago. That high-profile advocacy is being matched, moreover,…

  9. AMORE: Applied Momentum for Orbital Refuse Elimination

    NASA Astrophysics Data System (ADS)

    Wolfson, M.

    2014-09-01

    The need for active orbital debris remediation has increasingly gained acceptance throughout the space community throughout the last decade as the threat to our assets has also increased. While there have been a wide variety of conceptual solutions proposed, a debris removal system has yet to be put in place. The challenges that stand in the way of action are formidable and range from technical to political to economic. The AMORE concept is a nascent technique that has the potential to address these challenges and bring active debris remediation into reality. It uses an on-orbit low energy neutral particle beam (~10 keV, TBD) to impart momentum onto medium (5mm 10 cm) debris objects in Low Earth Orbit (LEO), thereby reducing their kinetic energy and expediting their reentry. The advantage of this technique over other proposed concepts is that it does not require delta-V intensive rendezvous, has an effective range that allows daily access to hundreds of debris objects, and does not create policy concerns over violation of international treaties. In essence, AMORE would be a medium-sized high power satellite with one or more particle beams fed by a large propellant tank, and an on-board tracking sensor that provides beam control. The particle beam would be similar to existing Xenon Hall Effect thrusters being used today, with the addition of a beam lens that would focus and aim the beam. The primary technical challenge of this concept is the focusing, pointing, and closed loop control of the beam that is necessary to maintain effective momentum transfer at ranges up to 100 km. This effective range is critical in order to maximize daily access to debris objects. Even in the densely populated 800 km debris band, it can be expected that a single AMORE system would be within 100 km of a debris object less than an hour a day. Space is big, and range is critical for timely, cost effective debris removal. Initial analysis indicates that a single AMORE vehicle operating in the 800 km regime could lower the perigee of 100 pieces of 1 kg debris to a 25 year reentry orbit annually. The actual performance of a system would be highly dependent on the debris regime. An operational AMORE system would likely involve several vehicles operating autonomously for continuous mitigation of existing and future debris.

  10. Interface between path and orbital angular momentum entanglement for high-dimensional photonic quantum information.

    PubMed

    Fickler, Robert; Lapkiewicz, Radek; Huber, Marcus; Lavery, Martin P J; Padgett, Miles J; Zeilinger, Anton

    2014-01-01

    Photonics has become a mature field of quantum information science, where integrated optical circuits offer a way to scale the complexity of the set-up as well as the dimensionality of the quantum state. On photonic chips, paths are the natural way to encode information. To distribute those high-dimensional quantum states over large distances, transverse spatial modes, like orbital angular momentum possessing Laguerre Gauss modes, are favourable as flying information carriers. Here we demonstrate a quantum interface between these two vibrant photonic fields. We create three-dimensional path entanglement between two photons in a nonlinear crystal and use a mode sorter as the quantum interface to transfer the entanglement to the orbital angular momentum degree of freedom. Thus our results show a flexible way to create high-dimensional spatial mode entanglement. Moreover, they pave the way to implement broad complex quantum networks where high-dimensionally entangled states could be distributed over distant photonic chips. PMID:25073906

  11. Angular Momentum Evolution During Star and Planetary System Formation

    NASA Astrophysics Data System (ADS)

    Davies, Claire; Greaves, Jane

    2013-07-01

    If all angular momentum contained within collapsing cores was conserved during star formation, proto-stars would reach break-up velocities before reaching the main-sequence. Therefore, methods by which proto-stars can lose angular momentum must exist. It may be possible for stellar angular momentum to be transferred from star to disc via stellar magnetic field lines through a process called magnetic braking. Alternatively, the stellar angular momentum may be lost from the star-disc system completely via stellar or disc winds. The proportion of lost stellar angular momentum that is retained within the circumstellar disc is important to studies of planetary system formation. An increase in disc angular momentum may cause a reduction in the disc surface density, often used as an indicator of a disc's ability to form planets. We introduce the disc-to-stellar angular momentum ratio as an indicator of the angular momentum retained within the disc and present results following its evolution during the first ~1-2Myrs for two distinct regions, namely the Orion Nebula Cluster (ONC) and Taurus-Auriga. We make use of data available in the literature for our calculations. We find that the more dense environment of the ONC harbours smaller and less massive discs than the less dense Taurus-Auriga region. Additionally, within each individual region, older discs appear preferentially larger and less massive. Our results indicate that both environment and age are important factors in the angular momentum evolution of circumstellar discs.

  12. Heat transfer under heating of a local region of a large production area by gas infrared radiators

    NASA Astrophysics Data System (ADS)

    Kuznetsov, G. V.; Kurilenko, N. I.; Maksimov, V. I.; Mamontov, G. Ya.; Nagornova, T. A.

    2013-05-01

    This paper presents the results of a computational modeling of the processes of heat transfer in a region having the size of a local working zone and heated due to the energy input from gas infrared radiators. The regimes of turbulent natural conjugate convection with one boundary open for air have been investigated. The plane nonstationary problem has been solved from the viewpoint of the Navier-Stokes model for the gas and the heat conduction for solid walls.

  13. Largely ignored: the impact of the threshold value for a QALY on the importance of a transferability factor

    Microsoft Academic Search

    Pepijn VemerMaureen; Maureen P. M. H. Rutten-van Mölken

    2011-01-01

    Recently, several checklists systematically assessed factors that affect the transferability of cost-effectiveness (CE) studies\\u000a between jurisdictions. The role of the threshold value for a QALY has been given little consideration in these checklists,\\u000a even though the importance of a factor as a cause of between country differences in CE depends on this threshold. In this\\u000a paper, we study the impact

  14. Analysis techniques for momentum transport

    SciTech Connect

    Scott, S.D.

    1991-08-01

    This report discusses the following topics on momentum analysis in tokamaks and stellarators: the momentum balance equation; deposition of torque by neutral beams; effects of toroidal rotation; and experimental observations. (LSP)

  15. Gaussian beams with very high orbital angular momentum

    Microsoft Academic Search

    J. Courtial; K. Dholakia; L. Allen; M. J. Padgett

    1997-01-01

    An elliptical Gaussian beam focussed by a cylindrical lens can possess large amounts of orbital angular momentum. We give an expression for the angular momentum, which arises from the azimuthal component of the Poynting vector, and show that it can be as high as 10 000 ?per photon. We examine the phase distribution of the beams in an interference experiment.

  16. Factors influencing the efficiency of generating genetically engineered pigs by nuclear transfer: multi-factorial analysis of a large data set

    PubMed Central

    2013-01-01

    Background Somatic cell nuclear transfer (SCNT) using genetically engineered donor cells is currently the most widely used strategy to generate tailored pig models for biomedical research. Although this approach facilitates a similar spectrum of genetic modifications as in rodent models, the outcome in terms of live cloned piglets is quite variable. In this study, we aimed at a comprehensive analysis of environmental and experimental factors that are substantially influencing the efficiency of generating genetically engineered pigs. Based on a considerably large data set from 274 SCNT experiments (in total 18,649 reconstructed embryos transferred into 193 recipients), performed over a period of three years, we assessed the relative contribution of season, type of genetic modification, donor cell source, number of cloning rounds, and pre-selection of cloned embryos for early development to the cloning efficiency. Results 109 (56%) recipients became pregnant and 85 (78%) of them gave birth to offspring. Out of 318 cloned piglets, 243 (76%) were alive, but only 97 (40%) were clinically healthy and showed normal development. The proportion of stillborn piglets was 24% (75/318), and another 31% (100/318) of the cloned piglets died soon after birth. The overall cloning efficiency, defined as the number of offspring born per SCNT embryos transferred, including only recipients that delivered, was 3.95%. SCNT experiments performed during winter using fetal fibroblasts or kidney cells after additive gene transfer resulted in the highest number of live and healthy offspring, while two or more rounds of cloning and nuclear transfer experiments performed during summer decreased the number of healthy offspring. Conclusion Although the effects of individual factors may be different between various laboratories, our results and analysis strategy will help to identify and optimize the factors, which are most critical to cloning success in programs aiming at the generation of genetically engineered pig models. PMID:23688045

  17. Pumping angular momentum by driven chaotic scattering

    E-print Network

    T. Dittrich; F. L. Dubeibe

    2008-04-29

    Chaotic scattering with an internal degree of freedom and the possibility to generate directed transport of angular momentum is studied in a specific model, a magnetic dipole moving in a periodically modulated magnetic field confined to a compact region in space. We show that this system is an irregular scatterer in large parts of its parameter space. If in addition all spatio-temporal symmetries are broken, directed transport of mass as well as angular momentum occurs. The sensitive parameter dependence of the corresponding currents includes frequent sign reversals. Zeros of either quantity entail the exclusive occurrence of the other and thus give rise in particular to angular-momentum separation without mass transport as a classical analogue of spin-polarized currents.

  18. Lagrange-mesh calculations in momentum space.

    PubMed

    Lacroix, Gwendolyn; Semay, Claude; Buisseret, Fabien

    2012-08-01

    The Lagrange-mesh method is a powerful method to solve eigenequations written in configuration space. It is very easy to implement and very accurate. Using a Gauss quadrature rule, the method requires only the evaluation of the potential at some mesh points. The eigenfunctions are expanded in terms of regularized Lagrange functions which vanish at all mesh points except one. It is shown that this method can be adapted to solve eigenequations written in momentum space, keeping the convenience and the accuracy of the original technique. In particular, the kinetic operator is a diagonal matrix. Observables and wave functions in both configuration space and momentum space can also be easily computed with good accuracy using only eigenfunctions computed in the momentum space. The method is tested with Gaussian and Yukawa potentials, requiring, respectively, a small and a large mesh to reach convergence. Corresponding wave functions in both spaces are compared with each other using the Fourier transform. PMID:23005880

  19. Momentum Transport in the Convective Boundary Layer

    NASA Astrophysics Data System (ADS)

    Soares, P. M. M.; Miranda, P. M. A.; Martins, J.; Teixeira, J.

    2010-09-01

    The sub-grid scale transport of momentum in the boundary layer is generally treated as a diffusive process in atmospheric models. However, results for the mean wind are frequently poor in test cases, and it is not clear how important are those fluxes in the performance of the models. Nevertheless, it is clear that convective momentum transport in a key issue in the atmospheric circulation, and in the interactions across multiple space and time scales. In the case of scalar fluxes, such as potential temperature and water vapour, it has been shown that "non-local" transport plays an important role in the turbulent transport, implying that a purely diffusive representation is insufficient. Counter-gradient, mass-flux theories and the combined eddy-diffusivity/mass-flux (EDMF) scheme were built to overcome that problem. The role of non-local effects in momentum is still largely an opened question. In the present study we use a extensive set of results from LES simulations to diagnose vertical profiles of momentum related quantities in different convective boundary layers: the nieuwstadt clear boundary layer, the trade wind cumulus BOMEX case, the shallow cumulus diurnal cycle from the ARM experiment and a LBA deep convection case. In many situations these results show that the momentum transport made by organized structures, as clouds, updraughts and downdraughts contribute significantly to the total turbulent flux, suggesting that they should be included in convective parameterizations.

  20. Quantized Rotation of Atoms From Photons with Orbital Angular Momentum

    E-print Network

    M. F. Andersen; C. Ryu; Pierre Clade; V. Natarajan; A. Vaziri; K. Helmerson; W. D. Phillips

    2006-10-20

    We demonstrate the coherent transfer of the orbital angular momentum of a photon to an atom in quantized units of hbar, using a 2-photon stimulated Raman process with Laguerre-Gaussian beams to generate an atomic vortex state in a Bose-Einstein condensate of sodium atoms. We show that the process is coherent by creating superpositions of different vortex states, where the relative phase between the states is determined by the relative phases of the optical fields. Furthermore, we create vortices of charge 2 by transferring to each atom the orbital angular momentum of two photons.

  1. Climate Momentum Simulation

    NSDL National Science Digital Library

    Drew Drew Jones

    The Climate Momentum Simulation allows users to quickly compare the resulting sea level rise, temperature change, atmospheric CO2, and global CO2 emissions from six different policy options: 1) Business As Usual, 2) March 2009 Country Proposals, 3) Flatten CO2 emissions by 2025, 4) 29% below 2009 levels by 2040, 5) 80% reduction of global fossil fuel plus a 90% reduction in land use emissions by 2050, and 6) 95 reduction of CO2 emissions by 2020). Based on the more complex C-ROADS simulator.

  2. Towards magnetic trapping and evaporative cooling of atoms with non-zero orbital angular momentum: suppression of electronic interaction anisotropy in transition metal atoms

    Microsoft Academic Search

    Roman Krems; Alexander Dalgarno

    2005-01-01

    Angular momentum transfer is expected to occur rapidly in collisions of atoms in states with non-zero angular momenta due to the large anisotropy of atom - atom electronic interactions. We show that despite the presence of internal angular momenta, transition metal atoms Sc (D-state atom) and Ti (F-state atom) interact in collisions with helium effectively as spherical atoms. The electronic

  3. Changes in angular momentum during the tennis serve.

    PubMed

    Bahamonde, R E

    2000-08-01

    Three-dimensional cinematography and the direct linear transformation method were used to obtain the coordinates of the landmarks of five right-handed collegiate tennis players. A 15-segment model was used to calculate the total body angular momentum about three orthogonal axes (X, parallel to the baseline; Y, normal to baseline and pointing towards the net; and Z, pointing upwards) passing through the centre of mass and to obtain the segmental contribution of the trunk, arms and legs. Most of the clockwise angular momentum about the X-axis was concentrated in the trunk and the racket-arm. Between the events of maximum external rotation and ball impact, the clockwise angular momentum about the X-axis of rotation of most body segments was reduced and the racket-arm gained clockwise angular momentum. The body angular momentum about the Y-axis of rotation had two distinct patterns and was the result of the lateral rotation of the trunk as the racket shoulder was elevated in preparation for impact. This body angular momentum was clockwise from the event of maximum external rotation to impact for the players with the greatest ball speed, whereas it was counterclockwise for the other players. The angular momentum about the Z-axis of rotation was small and lacked a consistent pattern. The largest source of angular momentum in the tennis serve derives from the remote angular momentum about the X- and Y-axes of rotation, which are then transferred from the trunk to the racket-arm and finally to the racket. Near impact, most of the angular momentum (75.1%) was concentrated in the racket-arm. Of the angular momentum of the racket-arm, the largest percentages were concentrated in the racket (35.9%) and the forearm segment (25.7%). PMID:10972409

  4. Gas mass transfer for stratified flows

    NASA Astrophysics Data System (ADS)

    Duffey, R. B.; Hughes, E. D.

    1995-04-01

    We analyzed gas absorption and release in water bodies using existing surface renewal theory. We show a new relation between turbulent momentum and mass transfer from gas to water, including the effects of waves and wave roughness, by evaluating the equilibrium integral turbulent dissipation due to energy transfer to the water from the wind. Using Kolmogoroff turbulence arguments the gas transfer velocity, or mass transfer coefficient, is then naturally and straightforwardly obtained as a non-linear function of the wind speed drag coefficient and the square root of the molecular diffusion coefficient. In dimensionless form, the theory predicts the turbulent Sherwood number to be Sh(sub t) = (2/(radical)(pi))Sc(sup 1/2), where Sh(sub t) is based on an integral dissipation length scale in the air. The theory confirms the observed nonlinear variation of the mass transfer coefficient as a function of the wind speed; gives the correct transition with turbulence-centered models for smooth surfaces at low speeds; and predicts experimental data from both laboratory and environmental measurements within the data scatter. The differences between the available laboratory and field data measurements are due to the large differences in the drag coefficient between wind tunnels and oceans. The results also imply that the effect of direct aeration due to bubble entrainment at wave breaking is no more than a 20% increase in the mass transfer for the highest speeds. The theory has importance to mass transfer in both the geo-physical and chemical engineering literature.

  5. THE JOURNAL OF CHEMICAL PHYSICS 135, 184202 (2011) Can stimulated Raman pumping cause large population transfers in

    E-print Network

    Zare, Richard N.

    THE JOURNAL OF CHEMICAL PHYSICS 135, 184202 (2011) Can stimulated Raman pumping cause large 2011; published online 9 November 2011) When stimulated Raman pumping (SRP) is applied to a stream with the energy difference between the pump and Stokes laser pulses. Using the optical Bloch-Feynman equations, we

  6. Magnetic field and angular momentum evolution models

    NASA Astrophysics Data System (ADS)

    Gallet, F.

    2013-11-01

    The magnetic field in young stellar object is clearly the most important component when one dealing with the angular momentum evolution of solar-like stars. It controls this latter one from the pre-main sequence, during the ``disk locking'' phase where the stars magnetically interact with their surrounding disk, to the main-sequence through powerful stellar winds that remove angular momentum from the stellar surface. We present new models for the rotational evolution of solar-like stars between 1 Myr and 10 Gyr with the aim to reproduce the distributions of rotational periods observed for star forming regions and young open clusters within this age range. Our simulations are produced by a recent model dedicated to the study of the angular momentum evolution of solar-type stars. This model include a new wind braking law based on recent numerical simulations of magnetized stellar winds and a specific dynamo and mass-loss prescription are used to link the angular momentum loss-rate to angular velocity evolution. The model additionally allows for a core/envelope decoupling with an angular momentum transfer between these two regions. Since this former model didn't include any physical star/disk interaction description, two star/disk interaction processes are eventually added to it in order to reproduce the apparent small angular velocities to which the stellar surface is subject during the disk accretion phase. We have developed rotational evolution models for slow, median and fast rotators including two star/disk interaction scenarios that are the magnetospheric ejection and the accretion powered stellar winds processes. The models appear to fail at reproducing the rotational behaviour of solar-type stars except when a more intense magnetic field is used during the disk accretion phase.

  7. Modeling of the cross-beam energy transfer with realistic inertial-confinement-fusion beams in a large-scale hydrocode

    NASA Astrophysics Data System (ADS)

    Colaïtis, A.; Duchateau, G.; Ribeyre, X.; Tikhonchuk, V.

    2015-01-01

    A method for modeling realistic laser beams smoothed by kinoform phase plates is presented. The ray-based paraxial complex geometrical optics (PCGO) model with Gaussian thick rays allows one to create intensity variations, or pseudospeckles, that reproduce the beam envelope, contrast, and high-intensity statistics predicted by paraxial laser propagation codes. A steady-state cross-beam energy-transfer (CBET) model is implemented in a large-scale radiative hydrocode based on the PCGO model. It is used in conjunction with the realistic beam modeling technique to study the effects of CBET between coplanar laser beams on the target implosion. The pseudospeckle pattern imposed by PCGO produces modulations in the irradiation field and the shell implosion pressure. Cross-beam energy transfer between beams at 20? and 40? significantly degrades the irradiation symmetry by amplifying low-frequency modes and reducing the laser-capsule coupling efficiency, ultimately leading to large modulations of the shell areal density and lower convergence ratios. These results highlight the role of laser-plasma interaction and its influence on the implosion dynamics.

  8. Ultrafast coherent control of angular momentum during a one-photon excitation

    SciTech Connect

    Malik, D. A.; Eppink, A. T. J. B.; Meerts, W. L.; Kimel, A. V.; Kirilyuk, A.; Rasing, Th.; Zande, W. J. van der [Radboud University Nijmegen, Institute for Molecules and Materials, P.O. Box 9010, NL-6500 GL Nijmegen (Netherlands)

    2011-10-15

    The subpicosecond dynamics of angular momentum transfer in the excited rubidium 5p state is studied in real time by observing photoelectron angular distributions with velocity map imaging. Retrieving the populations of the degenerate Zeeman levels and reconstructing the angular momentum, we show that in the case of resonant excitation the angular momentum does not follow the momentary helicity of the electric field of the pulse. This is in contrast with off-resonant excitation where the angular momentum and pulse helicity are fully correlated. Our study shows how to generate and shape ultrashort pulses of orbital and spin angular momentum in a controllable way.

  9. Gravity-Superconductors Interactions as a Possible Means to Exchange Momentum with the Vacuum

    E-print Network

    Giovanni Modanese

    2014-06-03

    We report on work in progress in quantum field theory about possible interactions between coherent matter, i.e. matter described by a macroscopic wave function or a classical field, and a certain class of vacuum fluctuations, called "zero-modes of the Einstein action". These are little-known virtual masses present in the vacuum state of quantum gravity. A couple of equal masses of this kind can be excited by an oscillating coherent source with frequency f and decays to its ground state emitting a virtual graviton, which can propagate and transfer momentum p to ordinary matter. The virtual masses recoil in the emission, and this amounts to a transfer of momentum -p to the vacuum; this momentum can be passed in turn to some matter, or not. The energy hf for the process does not come from the vacuum, but from the coherent source. The ratio hf/p is of the order of 1 m/s. This model was developed to explain experimental results showing the emission of anomalous high-momentum radiation from certain superconductors, sometimes with a strong recoil of the emitters. The recoil is energetically quite efficient, at least at small power, and could be exploited for propulsion. It has not been tested in space, however, and our model cannot yet predict if the recoil is affected by the presence of near matter. (Another model predicts that it is not.) We also briefly mention a possible application of the anomalous radiation itself and we evaluate the (large) electric and magnetic field strength needed to produce an effect equivalent to that of a superconducting emitter.

  10. Heavy-flavor in-medium momentum evolution: Langevin versus Boltzmann approach

    NASA Astrophysics Data System (ADS)

    Das, Santosh K.; Scardina, Francesco; Plumari, Salvatore; Greco, Vincenzo

    2014-10-01

    The propagation of heavy quarks in the quark-gluon plasma was often treated within the framework of the Langevin equation (LV), i.e., assuming the momentum transfer is small or the scatterings are sufficiently forward peaked, small screening mass mD. We address a direct comparison between the Langevin dynamics and the Boltzmann collisional integral (BM) when a bulk medium is in equilibrium at fixed temperature. We show that unless the cross section is quite forward peaked (mD?T) or the mass to temperature ratio is quite large (MHQ/T? 8-10) there are significant differences in the evolution of the p spectra and consequently on the nuclear modification factor RAA(pT). However, for charm quark we find that very similar RAA(pT) between the LV and BM can be obtained, but with a modified diffusion coefficient of about ˜15%-50% depending on the angular dependence of the cross section which regulates the momentum transfer. Studying also the momentum spread suffered by the single heavy quarks we see that at temperatures T ?250MeV the dynamics of the scatterings is far from being of Brownian type for charm quarks. In the case of bottom quarks we essentially find no differences in the time evolution of the momentum spectra between the LV and the BM dynamics independently of the angular dependence of the cross section, at least in the range of temperature relevant for ultrarelativistic heavy-ion collisions (HICs). Finally, we have shown the possible impact of this study on RAA(pT) and v2(pT) for a realistic simulation of relativistic HICs. For larger mD the elliptic flow can be about 50% larger for the Boltzmann dynamics with respect to the Langevin. This is helpful for a simultaneous reproduction of RAA(pT) and v2(pT).

  11. Emittance compensation studies of photoinjector beams with angular momentum

    SciTech Connect

    Lidia, Steven

    2003-05-19

    Beam dynamics studies on the FNPL photo injector that seek to optimize the transport of intense electron beams with large values of canonical angular momentum have been performed. These studies investigate the effect of solenoid emittance compensation on beams that evolve under the combined influence of intense space charge forces and large angular momentum. We present details of experimental measurements and supporting simulations of beam envelope evolution.

  12. A Large-Scale Allosteric Transition in Cytochrome P450 3A4 Revealed by Luminescence Resonance Energy Transfer (LRET)

    PubMed Central

    Sineva, Elena V.; Rumfeldt, Jessica A. O.; Halpert, James R.; Davydov, Dmitri R.

    2013-01-01

    Effector-induced allosteric transitions in cytochrome P450 3A4 (CYP3A4) were investigated by luminescence resonance energy transfer (LRET) between two SH-reactive probes attached to various pairs of distantly located cysteine residues, namely the double-cysteine mutants CYP3A4(C64/C468), CYP3A4(C377/C468) and CYP3A4(C64/C121). Successive equimolar labeling of these proteins with the phosphorescent probe erythrosine iodoacetamide (donor) and the near-infrared fluorophore DY-731 maleimide (acceptor) allowed us to establish donor/acceptor pairs sensitive to conformational motions. The interactions of all three double-labeled mutants with the allosteric activators ?-naphthoflavone and testosterone resulted in an increase in the distance between the probes. A similar effect was elicited by cholesterol. These changes in distance vary from 1.3 to 8.5 Å, depending on the position of the donor/acceptor pair and the nature of the effector. In contrast, the changes in the interprobe distance caused by such substrates as bromocriptine or 1-pyrenebutanol were only marginal. Our results provide a decisive support to the paradigm of allosteric modulation of CYP3A4 and indicate that the conformational transition caused by allosteric effectors increases the spatial separation between the beta-domain of the enzyme (bearing residues Cys64 and Cys377) and the alpha-domain, where Cys121 and Cys468 are located. PMID:24376769

  13. MINET (momentum integral network) code documentation

    SciTech Connect

    Van Tuyle, G J; Nepsee, T C; Guppy, J G [Brookhaven National Lab., Upton, NY (USA)

    1989-12-01

    The MINET computer code, developed for the transient analysis of fluid flow and heat transfer, is documented in this four-part reference. In Part 1, the MINET models, which are based on a momentum integral network method, are described. The various aspects of utilizing the MINET code are discussed in Part 2, The User's Manual. The third part is a code description, detailing the basic code structure and the various subroutines and functions that make up MINET. In Part 4, example input decks, as well as recent validation studies and applications of MINET are summarized. 32 refs., 36 figs., 47 tabs.

  14. Quark Orbital Angular Momentum in the Baryon

    E-print Network

    Xiaotong Song

    2001-06-25

    Analytical and numerical results, for the orbital and spin content carried by different quark flavors in the baryons, are given in the chiral quark model with symmetry breaking. The reduction of the quark spin, due to the spin dilution in the chiral splitting processes, is transferred into the orbital motion of quarks and antiquarks. The orbital angular momentum for each quark flavor in the proton as a function of the partition factor $\\kappa$ and the chiral splitting probability $a$ is shown. The cancellation between the spin and orbital contributions in the spin sum rule and in the baryon magnetic moments is discussed.

  15. Momentum and Its Conversion

    NSDL National Science Digital Library

    The Physics Classroom presents this tutorial on momentum and its conversion. The three laws are three laws are explained and their application to the analysis of the motion of objects in one dimension is discussed. There are four separate lessons which provide an activity and then an assessment exercise in order for students to check their understanding of the concept (s). Some of the key topics included here are: state of motion, force, gravitational pull, vector quantity, force, Newton's second law of motion, and Newton's third law of motion. The tutorial is geared toward high school students, but it is also great review material for college physics students or anyone needing a refresher course in vectors.

  16. The effects of Reynolds number, rotor incidence angle, and surface roughness on the heat transfer distribution in a large-scale turbine rotor passage

    NASA Technical Reports Server (NTRS)

    Blair, Michael F.; Anderson, Olof L.

    1989-01-01

    A combined experimental and computational program was conducted to examine the heat transfer distribution in a turbine rotor passage geometrically similiar to the Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump (HPFTP). Heat transfer was measured and computed for both the full-span suction and pressure surfaces of the rotor airfoil as well as for the hub endwall surface. The primary objective of the program was to provide a benchmark-quality data base for the assessment of rotor passage heat transfer computational procedures. The experimental portion of the study was conducted in a large-scale, ambient temperature, rotating turbine model. Heat transfer data were obtained using thermocouple and liquid-crystal techniques to measure temperature distributions on the thin, electrically-heated skin of the rotor passage model. Test data were obtained for various combinations of Reynolds number, rotor incidence angle and model surface roughness. The data are reported in the form of contour maps of Stanton number. These heat distribution maps revealed numerous local effects produced by the three-dimensional flows within the rotor passage. Of particular importance were regions of local enhancement produced on the airfoil suction surface by the main-passage and tip-leakage vortices and on the hub endwall by the leading-edge horseshoe vortex system. The computational portion consisted of the application of a well-posed parabolized Navier-Stokes analysis to the calculation of the three-dimensional viscous flow through ducts simulating the a gas turbine passage. These cases include a 90 deg turning duct, a gas turbine cascade simulating a stator passage, and a gas turbine rotor passage including Coriolis forces. The calculated results were evaluated using experimental data of the three-dimensional velocity fields, wall static pressures, and wall heat transfer on the suction surface of the turbine airfoil and on the end wall. Particular attention was paid to an accurate modeling of the passage vortex and to the development of the wall boundary layers including crossflow.

  17. Nucleon Momentum Decomposition in QCD

    E-print Network

    Y. M. Cho; Mo-Lin Ge; D. G. Pak; Pengming Zhang

    2011-04-29

    ~Based on the gauge invariant quark canonical momentum we construct two theoretically possible decompositions of nucleon momentum to those of quarks and gluons. We predict that either 6% or 21% of nucleon momentum is carried by gluons, depending on what type of gluons are in nucleons. We clarify the existing confusions on this problem and discuss the physical implications of our result on the proton spin crisis problem.

  18. Angular Momentum in Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Del Popolo, A.

    We study the ``angular momentum catastrophe" in the framework of interaction among baryons and dark matter through dynamical friction. By means of Del Popolo (2009) model we simulate 14 galaxies similar to those investigated by van den Bosch, Burkert and Swaters (2001), and calculate the distribution of their spin parameters and the angular momenta. Our model gives the angular momentum distribution which is in agreement with the van den Bosch et al. observations. Our result shows that the ``angular momentum catastrophe" can be naturally solved in a model that takes into account the baryonic physics and the exchange of energy and angular momentum between the baryonic clumps and dark matter through dynamical friction.

  19. Force As A Momentum Current

    SciTech Connect

    Munera, Hector A. [International Center for Physics (CIF, Centro Internacional de Fisica), Apartado 4948, Bogota (Colombia)

    2010-07-28

    Advantages of a neo-Cartesian approach to classical mechanics are noted. If conservation of linear momentum is the fundamental principle, Newton's three laws become theorems. A minor paradox in static Newtonian mechanics is identified, and solved by reinterpreting force as a current of momentum. Contact force plays the role of a mere midwife in the exchange of momentum; however, force cannot be eliminated from physics because it provides the numerical value for momentum current. In this sense, in a neo-Cartesian formulation of mechanics the concept of force becomes strengthened rather than weakened.

  20. High-momentum tails from low-momentum effective theories

    NASA Astrophysics Data System (ADS)

    Bogner, S. K.; Roscher, D.

    2012-12-01

    In a recent work, Anderson [Phys. Rev. CPRVCAN0556-281310.1103/PhysRevC.82.054001 82, 054001 (2010)] used the renormalization group (RG) evolution of the momentum distribution to show that, under appropriate conditions, operator expectation values exhibit factorization in the two-nucleon system. Factorization is useful because it provides a clean separation of long- and short-distance physics, and suggests a possible interpretation of the universal high-momentum dependence and scaling behavior found in nuclear momentum distributions. In the present work, we use simple decoupling and scale-separation arguments to extend the results of Anderson to arbitrary low-energy A-body states. Using methods that are reminiscent of the operator product expansion (OPE) in quantum field theory, we find that the high-momentum tails of momentum distributions and static structure factors factorize into the product of a universal function of momentum that is fixed by two-body physics, and a state-dependent matrix element that is the same for both and is sensitive only to low-momentum structure of the many-body state. As a check, we apply our factorization relations to two well studied systems, the unitary Fermi gas and the electron gas, and reproduce known expressions for the high-momentum tails of each.

  1. Sprinkler Head Revisited: Momentum, Forces, and Flows in Machian Propulsion

    ERIC Educational Resources Information Center

    Jenkins, Alejandro

    2011-01-01

    Many experimenters, starting with Ernst Mach in 1883, have reported that if a device alternately sucks in and then expels a surrounding fluid, it moves in the same direction as if it only expelled fluid. This surprising phenomenon, which we call "Machian propulsion", is explained by conservation of momentum: the outflow efficiently transfers…

  2. Moon-to-Earth: Eavesdropping on the GRAIL Inter-Spacecraft Time-Transfer Link Using a Large Antenna and a Software Receiver

    NASA Technical Reports Server (NTRS)

    Esterhuizen, Stephan

    2012-01-01

    NASA's twin GRAIL [1] spacecraft (Ebb and Flow) arrived at Earth's Moon on New Year's Day, 2012. GRAIL's primary mission is to create a high-resolution map of the Moon's gravitational field by measuring very precisely the change in distance between the two spacecraft [2]. Each spacecraft transmits two signals to the other spacecraft, a PRN code modulated on a 2 GHz carrier (S-band), as well as an unmodulated carrier at roughly 33 GHz (Ka-band). Since it's not feasible to synchronize the two GRAIL spacecraft's clocks via GPS (as was done with GRACE), the S-band signals are used as a time-transfer link to synchronize either Ebb's clock to Flow or vice versa. As an independent measure to determine the clock offset of the GRAIL ultra-stable oscillators to UTC(NIST), an experiment was conducted where our JPL team used a large antenna on Earth to eavesdrop on the inter-spacecraft time-transfer link.

  3. Widths of transverse momentum distributions in intermediate-energy heavy-ion collisions

    NASA Technical Reports Server (NTRS)

    Khan, Ferdous; Townsend, Lawrence W.

    1993-01-01

    The need to include dynamical collision momentum transfer contributions, arising from interacting nuclear and Coulomb fields, to estimates of fragment momentum distributions is discussed. Methods based upon an optical potential model are presented. Comparisons with recent experimental data of the Siegen group for variances of transverse momentum distributions for gold nuclei at 980 A MeV fragmenting on silver foil and plastic nuclear track detector targets are made. The agreement between theory and experiment is good.

  4. LABORATORY V CONSERVATION OF MOMENTUM

    E-print Network

    Minnesota, University of

    Lab V - 1 LABORATORY V CONSERVATION OF MOMENTUM In this lab you will use conservation of momentum enough information for a complete analysis of collisions in terms of forces. Conservation principles can of the complicated details of the collision process itself, but conservation of energy alone is usually not enough

  5. Conservation of Momentum Virtual Lab

    NSDL National Science Digital Library

    2014-04-03

    This virtual lab helps students explore the conservation of momentum. Simulated electronic balances, photogate timers, and rulers are designed to preserve as much of the traditional lab's educational experience as possible. Printable lab guides are included for the basic conservation of momentum lab, as well as elastic vs. inelastic collisions and the coefficient of restitution.

  6. Intrinsic Angular Momentum of Light.

    ERIC Educational Resources Information Center

    Santarelli, Vincent

    1979-01-01

    Derives a familiar torque-angular momentum theorem for the electromagnetic field, and includes the intrinsic torques exerted by the fields on the polarized medium. This inclusion leads to the expressions for the intrinsic angular momentum carried by the radiation traveling through a charge-free medium. (Author/MA)

  7. Recruiting and retaining geoscience students at a large public university: Balancing the needs of first-time freshman and upper-division transfer students

    NASA Astrophysics Data System (ADS)

    Bowman, D. D.; Clemens-Knott, D.

    2012-12-01

    The Department of Geological Sciences at California State University, Fullerton (CSUF) is one of the largest geology programs in the state. Approximately 4,000 students at CSUF take general education geology classes; this provides a large pool from which to recruit undergraduate students for either the Geology B.S. or Earth Sciences B.A. offered by the department. The department has seen a dramatic increase in majors over the last decade, from a low of 28 majors in 2002 to more than 110 in 2012. This increase does not appear to be driven by growth in the oil industry; in a recent survey of CSUF geoscience (BS or BA) students, 15% of respondents indicated an interest in a career in petroleum. The department has engaged in aggressive recruitment and outreach efforts over the last decade, with activities ranging from earthquake preparedness rallies in conjunction with the annual California ShakeOut, to an emerging high school and community college intern program at the department's paleontology curation facility. Despite these efforts, the majority of CSUF geoscience students declared the geology major after taking an introductory physical geology course either at CSUF or a local community college. Over the last ten years, approximately 50% of the geoscience majors at CSUF transferred from a community college. Among the geoscience students who began their career at CSUF, only one third had declared a geoscience major in their freshman year. Over two thirds of geoscience majors at CSUF declared their major after completing more than 60 units. The strong tendency for students to declare a geoscience major late in their career poses significant challenges to students' ability to graduate in a timely manner. To mitigate this problem, the department has an aggressive advising program, wherein students attend mandatory advising with a faculty member every semester. The department is also working closely with community college partners to improve the preparation of transfer students through advising partnerships facilitated by the NSF-sponsored STEM2 program, and through active collaboration in implementing a geology "Associate's Degree-for-Transfer" at community colleges under the framework of California's Student Transfer Achievement Reform Act (SB 1440).

  8. Transverse angular momentum of photons

    SciTech Connect

    Aiello, Andrea [Max Planck Institute for the Science of Light, Guenter-Scharowsky-Strasse 1/Bau 24, D-91058 Erlangen (Germany); Marquardt, Christoph; Leuchs, Gerd [Max Planck Institute for the Science of Light, Guenter-Scharowsky-Strasse 1/Bau 24, D-91058 Erlangen (Germany); Institute for Optics, Information and Photonics, University Erlangen-Nuernberg, Staudtstrasse 7/B2, D-91058 Erlangen (Germany)

    2010-05-15

    We develop the quantum theory of transverse angular momentum of light beams. The theory applies to paraxial and quasiparaxial photon beams in vacuum and reproduces the known results for classical beams when applied to coherent states of the field. Both the Poynting vector, alias the linear momentum, and the angular-momentum quantum operators of a light beam are calculated including contributions from first-order transverse derivatives. This permits a correct description of the energy flow in the beam and the natural emergence of both the spin and the angular momentum of the photons. We show that for collimated beams of light, orbital angular-momentum operators do not satisfy the standard commutation rules. Finally, we discuss the application of our theory to some concrete cases.

  9. Momentum transport in magnetic islands

    NASA Astrophysics Data System (ADS)

    Waelbroeck, F. L.; Grasso, D.; Porcelli, F.; Tebaldi, C.

    2006-04-01

    We examine the transport of momentum across an island using the reduced magnetohydrodynamic (RMHD) model. We find that the Reynolds stress gives rise to a momentum source proportional to the resistivity. As a result of the frozen-in property the transport of momentum can be described by a one-dimensional equation, even for islands with finite aspect-ratio. We present numerical and analytic solutions of this transport equation and compare these solutions to numerical solutions of the full time- dependent RMHD equations. Of particular interest is the momentum transport in islands where the helical current density reverses sign. In such islands, the Reynolds stress also reverses sign, creating the possibility for localized zonal flow generation. The constant-psi approximation, however, fails in the presence of current reversal. We have developed new equilibrium solutions for thin islands that we plan to use to examine the transport of momentum in the presence of current reversal.

  10. Radial transfer effects for poloidal rotation

    NASA Astrophysics Data System (ADS)

    Hallatschek, Klaus

    2010-11-01

    Radial transfer of energy or momentum is the principal agent responsible for radial structures of Geodesic Acoustic Modes (GAMs) or stationary Zonal Flows (ZF) generated by the turbulence. For the GAM, following a physical approach, it is possible to find useful expressions for the individual components of the Poynting flux or radial group velocity allowing predictions where a mathematical full analysis is unfeasible. Striking differences between up-down symmetric flux surfaces and asymmetric ones have been found. For divertor geometries, e.g., the direction of the propagation depends on the sign of the ion grad-B drift with respect to the X-point, reminiscent of a sensitive determinant of the H-mode threshold. In nonlocal turbulence computations it becomes obvious that the linear energy transfer terms can be completely overwhelmed by the action of the turbulence. In contrast, stationary ZFs are governed by the turbulent radial transfer of momentum. For sufficiently large systems, the Reynolds stress becomes a deterministic functional of the flows, which can be empirically determined from the stress response in computational turbulence studies. The functional allows predictions even on flow/turbulence states not readily obtainable from small amplitude noise, such as certain transport bifurcations or meta-stable states.

  11. Two-Nucleon Momentum Distributions Measured in 3He(e,e'pp)n

    Microsoft Academic Search

    R. A. Niyazov; L. B. Weinstein; G. Adams; P. Ambrozewicz; E. Anciant; M. Anghinolfi; B. Asavapibhop; G. Asryan; G. Audit; T. Auger; H. Avakian; H. Bagdasaryan; J. P. Ball; S. Barrow; M. Battaglieri; K. Beard; M. Bektasoglu; M. Bellis; N. Benmouna; B. L. Berman; W. Bertozzi; N. Bianchi; A. S. Biselli; S. Boiarinov; B. E. Bonner; S. Bouchigny; R. Bradford; D. Branford; W. K. Brooks; V. D. Burkert; C. Butuceanu; J. R. Calarco; D. S. Carman; B. Carnahan; C. Cetina; S. Chen; L. Ciciani; P. L. Cole; A. Coleman; D. Cords; P. Corvisiero; D. Crabb; H. Crannell; J. P. Cummings; E. de Sanctis; N. Dashyan; R. Devita; P. V. Degtyarenko; H. Denizli; L. Dennis; K. V. Dharmawardane; K. S. Dhuga; C. Djalali; G. E. Dodge; D. Doughty; P. Dragovitsch; M. Dugger; S. Dytman; O. P. Dzyubak; M. Eckhause; H. Egiyan; K. S. Egiyan; L. Elouadrhiri; A. Empl; P. Eugenio; R. Fatemi; R. J. Feuerbach; J. Ficenec; T. A. Forest; H. Funsten; G. Gavalian; S. Gilad; G. P. Gilfoyle; K. L. Giovanetti; P. Girard; C. I. Gordon; R. W. Gothe; K. Griffioen; M. Guidal; M. Guillo; L. Guo; V. Gyurjyan; C. E. Hyde-Wright; R. S. Hakobyan; J. Hardie; D. Heddle; F. W. Hersman; K. Hicks; M. Holtrop; J. Hu; Y. Ilieva; W. Ingram; M. M. Ito; D. Jenkins; K. Joo; H. G. Juengst; J. H. Kelley; J. Kellie; M. Khandaker; D. H. Kim; K. Y. Kim; M. S. Kim; W. Kim; A. Klein; F. J. Klein; A. V. Klimenko; M. Klusman; M. Kossov; L. H. Kramer; Y. Kuang; S. E. Kuhn; J. Kuhn; J. Lachniet; J. M. Laget; J. Langheinrich; D. Lawrence; Ji Li; K. Livingston; K. Lukashin; J. J. Manak; C. Marchand; S. McAleer; S. McLauchlan; J. W. McNabb; B. A. Mecking; S. Mehrabyan; J. J. Melone; M. D. Mestayer; C. A. Meyer; K. Mikhailov; M. Mirazita; R. Miskimen; L. Morand; S. A. Morrow; V. Muccifora; J. Mueller; G. S. Mutchler; J. Napolitano; R. Nasseripour; S. O. Nelson; S. Niccolai; G. Niculescu; I. Niculescu; B. B. Niczyporuk; M. Nozar; G. V. O'Rielly; M. Osipenko; E. Pasyuk; G. Peterson; S. A. Philips; N. Pivnyuk; D. Pocanic; O. Pogorelko; E. Polli; S. Pozdniakov; B. M. Preedom; J. W. Price; Y. Prok; D. Protopopescu; L. M. Qin; B. A. Raue; G. Riccardi; G. Ricco; M. Ripani; B. G. Ritchie; F. Ronchetti; P. Rossi; D. Rowntree; P. D. Rubin; F. Sabatié; K. Sabourov; C. Salgado; J. P. Santoro; V. Sapunenko; R. A. Schumacher; V. S. Serov; A. Shafi; Y. G. Sharabian; J. Shaw; S. Simionatto; A. V. Skabelin; E. S. Smith; L. C. Smith; D. I. Sober; M. Spraker; A. Stavinsky; S. Stepanyan; P. Stoler; I. I. Strakovsky; S. Strauch; M. Taiuti; S. Taylor; D. J. Tedeschi; U. Thoma; R. Thompson; L. Todor; C. Tur; M. Ungaro; M. F. Vineyard; A. V. Vlassov; K. Wang; H. Weller; D. P. Weygand; C. S. Whisnant; E. Wolin; M. H. Wood; A. Yegneswaran; J. Yun; B. Zhang

    2004-01-01

    We have measured the 3He(e,e'pp)n reaction at 2.2GeV over a wide kinematic range. The kinetic energy distribution for ``fast'' nucleons (p>250 MeV\\/c) peaks where two nucleons each have 20% or less, and the third nucleon has most of the transferred energy. These fast pp and pn pairs are back to back with little momentum along the three-momentum transfer, indicating that

  12. The angular momentum dependence of complex fragment emission

    SciTech Connect

    Sobtka, L.G.; Sarantites, D.G.; Li, Z.; Dines, E.L.; Halbert, M.L.; Hensley, D.C.; Schmitt, R.P.; Majka, Z.; Nebbia, G.; Griffin, H.C.

    1987-01-01

    Large fragment (A > 4) production at high angular momentum is studied via the reaction, 200 MeV /sup 45/Sc + /sup 65/Cu. Comparisons of the fragment yields from this reaction (high angular momentum) to those from /sup 93/Nb + Be (low angular momentum) are used to verify the strong angular momentum dependence of large fragment production predicted by equilibrium models. Details of the coincident ..gamma..-ray distributions not only confirm a rigidly rotating intermediate but also indicate that the widths of the primary L-wave distributions decrease with increasing symmetry in the decay channel. These data are used to test the asymmetry and L-wave dependence of emission barriers calculated from a rotating, finite range corrected, liquid drop model. 21 refs., 10 figs.

  13. Use of nitrogen to remove solvent from through oven transfer adsorption desorption interface during analysis of polycyclic aromatic hydrocarbons by large volume injection in gas chromatography.

    PubMed

    Áragón, Alvaro; Toledano, Rosa M; Cortés, José M; Vázquez, Ana M; Villén, Jesús

    2014-04-25

    The through oven transfer adsorption desorption (TOTAD) interface allows large volume injection (LVI) in gas chromatography and the on-line coupling of liquid chromatography and gas chromatography (LC-GC), enabling the LC step to be carried out in normal as well as in reversed phase. However, large amounts of helium, which is both expensive and scarce, are necessary for solvent elimination. We describe how slight modification of the interface and the operating mode allows nitrogen to be used during the solvent elimination steps. In order to evaluate the performance of the new system, volumes ranging from 20 to 100?L of methanolic solutions of four polycyclic aromatic hydrocarbons (PAHs) were sampled. No significant differences were found in the repeatability and sensitivity of the analyses of standard PAH solutions when using nitrogen or helium. The performance using the proposed modification was similar and equally satisfactory when using nitrogen or helium for solvent elimination in the TOTAD interface. In conclusion, the use of nitrogen will make analyses less expensive. PMID:24657145

  14. Average Transverse Momentum Quantities Approaching the Lightfront

    NASA Astrophysics Data System (ADS)

    Boer, Daniël

    2015-01-01

    In this contribution to Light Cone 2014, three average transverse momentum quantities are discussed: the Sivers shift, the dijet imbalance, and the p T broadening. The definitions of these quantities involve integrals over all transverse momenta that are overly sensitive to the region of large transverse momenta, which conveys little information about the transverse momentum distributions of quarks and gluons inside hadrons. TMD factorization naturally suggests alternative definitions of such integrated quantities, using Bessel-weighting and rapidity cut-offs, with the conventional definitions as limiting cases. The regularized quantities are given in terms of integrals over the TMDs of interest that are well-defined and moreover have the advantage of being amenable to lattice evaluations.

  15. Energy-momentum tensor correlators and viscosity

    E-print Network

    Harvey B. Meyer

    2008-09-30

    Collective flow has been observed in heavy ion collisions, with a large anisotropic component, and ideal hydrodynamic calculations had significant successful in describing the distribution of produced particles at the RHIC experiments. In order to account for this near ideal fluid behavior, the shear and bulk viscosity of the quark gluon plasma (QGP) must be computed from first principles in a regime where the QGP is not weakly coupled. In this talk I describe recent progress in computing energy-momentum tensor correlators on the lattice from which the viscosities can be extracted via Kubo formulas. I also show how to cumulate information from several channels, including at non-vanishing spatial momentum, in order to best constrain the viscosities. These methods should soon yield predictions at the higher temperatures that will be explored at the LHC experiments.

  16. Momentum Transport in Granular Flows

    E-print Network

    Gregg Lois; Anael Lemaitre; Jean M. Carlson

    2006-02-10

    We investigate the error induced by only considering binary collisions in the momentum transport of hard-sphere granular materials, as is done in kinetic theories. In this process, we first present a general microscopic derivation of the momentum transport equation and compare it to the kinetic theory derivation, which relies on the binary collision assumption. These two derivations yield different microscopic expressions for the stress tensor, which we compare using simulations. This provides a quantitative bound on the regime where binary collisions dominate momentum transport and reveals that most realistic granular flows occur in the region of phase space where the binary collision assumption does not apply.

  17. Angular momentum evolution for galaxies

    E-print Network

    Pedrosa, Susana

    2015-01-01

    Using cosmological hydrodynamics simulations we study the angular momentum content of the simulated galaxies in relation with their morphological type. We found that not only the angular momentum of the disk component follow the expected theoretical relation, Mo, Mao & Whiye (1998), but also the spheroidal one, with a gap due to its lost of angular momentum, in agreement with Fall & Romanowsky (2013),. We also found that the galaxy size can plot in one general relation, despite the morphological type, as found by Kravtsov (2013).

  18. Measurements of the Proton Electromagnetic Form Factor Ratio From Elastic e + p -> e + p Scattering at Momentum Transfer Q^2 = 2.5, 5.2, 6.7 and 8.5 (GeV/c)^2

    SciTech Connect

    Arthur Mkrtchyan

    2012-05-31

    Among the fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing the strong interaction dyna mics of the nucleon's quark constituents. Electromagnetic probes are traditionally preferered to the hadronic beams. The electromagnetic interaction is a powerful tool for investigating the nucleon structure since it is well understood and it reveals observables that can be directly interpreted in terms of the current carried by the quarks. Elastic scattering leads to the form factors that describe the spatial charge a nd current distributions inside the nucleon. The reaction mechanism is assumed to be one photon exchange, the electromagnetic interaction is exactly calculable in QED, and one can safely extract the information on the hadronic vertex. The most important feature of early measurements of proton form factor ratio G{sub E}{sup p}/G{sub M}{sup p} with recoil polarization technique at Q{sup 2} up to 5.6 (GeV/c){sup 2} is the sharp decline of the ratio with Q{sup 2} increases, indicating that G{sub E}{sup p} falls much faster than G{sub M}{sup p}. This contradicts to data obtained by Rosenbluth separation method. An intriguing question was whether G{sub E}{sup p} will continue to decrease or become constant when Q{sup 2} increases. New set of measurements of proton form factor ratio G{sub E}{sup p}/G{sub M}{sup p} at Q{sup 2} = 2.5, 5.2, 6.7 and 8.5 (GeV/c){sup 2} have been conducted at JLab Hall C using {approx}85% longitudinally polarized electron elastic scattering from unpolarized hydrogen target. Recoil protons were detected in the HMS magnetic spectrometer with the standard detector package, combined with newly installed trigger scintillators and Focal Plane Polarimeter. The BigCal electromagnetic calorimeter (1744 channel) have been used for electron detection. Data obtained in this experiment show that G{sub E}{sup p}/G{sub M}{sup p} ratio continued to drop with Q{sup 2} and may cross 'zero' at Q{sup 2} > 10-15 (GeV/c){sup 2}. Intensive theoretical and experimental efforts over the past decade have aimed at explaining the discrepancy between data for the proton form factor ratio G{sub E}{sup p}/G{sub M}{sup p} obtained from cross section and polarization measurements. It was assumed that the two photon exchange contribution might be responsible for difference of G{sub E}{sup p}/G{sub M}{sup p} ratio obtained by Rosenbluth separation method and recoil polarization technique. The kinematical dependence of polarization transfer observables in elastic electron-proton scattering at Q{sup 2} = 2.5 (GeV/c){sup 2} have been used in search of effects of 2{gamma} contribution. For a wide range of values of the virtual photon polarization {epsilon} ({epsilon} = 0.15, 0.63, and 0.77), the proton form factor ratio and longitudinal polarization transfer component were measured with statistical uncertainties of {+-}0.01 and {+-}0.005, respectively. Our data provide significant constraints on models of nucleon structure.

  19. Mercury in aquatic forage of large herbivores: impact of environmental conditions, assessment of health threats, and implications for transfer across ecosystem compartments.

    PubMed

    Bergman, Brenda Gail; Bump, Joseph K

    2014-05-01

    Mercury (Hg) is a leading contaminant across U.S. water bodies, warranting concern for wildlife species that depend upon food from aquatic systems. The risk of Hg toxicity to large herbivores is little understood, even though some large herbivores consume aquatic vascular plants (macrophytes) that may hyper-accumulate Hg. We investigated whether total Hg and methylmercury (MeHg) in aquatic forage may be of concern to moose (Alces alces) and beaver (Castor canadensis) by measuring total Hg and MeHg concentrations, calculating sediment-water bioconcentration factors for macrophyte species these herbivores consume, and estimating herbivore daily Hg consumption. Abiotic factors impacting macrophyte Hg were assessed, as was the difference in Hg concentrations of macrophytes from glacial lakes and those created or expanded by beaver damming. The amount of aquatic-derived Hg that moose move from aquatic to terrestrial systems was calculated, in order to investigate the potential for movement of Hg across ecosystem compartments by large herbivores. Results indicate that the Hg exposure of generalist herbivores may be affected by macrophyte community composition more so than by many abiotic factors in the aquatic environment. Mercury concentrations varied greatly between macrophyte species, with relatively high concentrations in Utricularia vulgaris (>80 ng g(-1) in some sites), and negligible concentrations in Nuphar variegata (~6 ng g(-1)). Macrophyte total Hg concentration was correlated with water pH in predictable ways, but not with other variables generally associated with aquatic Hg concentrations, such as dissolved organic carbon. Moose estimated daily consumption of MeHg is equivalent to or below human reference levels, and far below wildlife reference levels. However, estimated beaver Hg consumption exceeds reference doses for humans, indicating the potential for sub-lethal nervous impairment. In regions of high moose density, moose may be ecologically important vectors that transfer Hg from aquatic to surrounding terrestrial systems. PMID:24534700

  20. Role of final state interactions in quasielastic [sup 56]Fe([ital e],[ital e][prime]) reactions at large [vert bar][ital [rvec q

    SciTech Connect

    Chinn, C.R. (Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States))

    1995-04-01

    A relativistic finite nucleus calculation using a Dirac optical potential is used to investigate the importance of final state interactions (FSI) at large momentum transfers in inclusive quasielastic electronuclear reactions. The optical potential is derived from first-order multiple scattering theory and then is used to calculate the FSI in a nonspectral Green's function doorway approach. At intermediate momentum transfers excellent predictions of the quasielastic [sup 56]Fe([ital e],[ital e][prime]) experimental data for the longitudinal response function are obtained. In comparisons with recent measurements at [vert bar][ital [rvec q

  1. Creation of orbital angular momentum states with chiral polaritonic lenses.

    PubMed

    Dall, Robert; Fraser, Michael D; Desyatnikov, Anton S; Li, Guangyao; Brodbeck, Sebastian; Kamp, Martin; Schneider, Christian; Höfling, Sven; Ostrovskaya, Elena A

    2014-11-14

    Controlled transfer of orbital angular momentum to an exciton-polariton Bose-Einstein condensate spontaneously created under incoherent, off resonant excitation conditions is a long-standing challenge in the field of microcavity polaritonics. We demonstrate, experimentally and theoretically, a simple and efficient approach to the generation of nontrivial orbital angular momentum states by using optically induced potentials-chiral polaritonic lenses. These lenses are produced by a structured optical pump with a spatial distribution of intensity that breaks the chiral symmetry of the system. PMID:25432029

  2. A Compact Ring Design with Tunable Momentum Compaction

    SciTech Connect

    Sun, Y.; /SLAC; ,

    2012-05-17

    A storage ring with tunable momentum compaction has the advantage in achieving different RMS bunch length with similar RF capacity, which is potentially useful for many applications, such as linear collider damping ring and predamping ring where injected beam has a large energy spread and a large transverse emittance. A tunable bunch length also makes the commissioning and fine tuning easier in manipulating the single bunch instabilities. In this paper, a compact ring design based on a supercell is presented, which achieves a tunable momentum compaction while maintaining a large dynamic aperture.

  3. Momentum Confinement at Low Torque

    SciTech Connect

    Solomon, W M; Burrell, K H; deGrassie, J S; Budny, R; Groebner, R J; Heidbrink, W W; Kinsey, J E; Kramer, G J; Makowski, M A; Mikkelsen, D; Nazikian, R; Petty, C C; Politzer, P A; Scott, S D; Van Zeeland, M A; Zarnstorff, M C

    2007-06-26

    Momentum confinement was investigated on DIII-D as a function of applied neutral beam torque at constant normalized {beta}{sub N}, by varying the mix of co (parallel to the plasma current) and counter neutral beams. Under balanced neutral beam injection (i.e. zero total torque to the plasma), the plasma maintains a significant rotation in the co-direction. This 'intrinsic' rotation can be modeled as being due to an offset in the applied torque (i.e. an 'anomalous torque'). This anomalous torque appears to have a magnitude comparable to one co-neutral beam source. The presence of such an anomalous torque source must be taken into account to obtain meaningful quantities describing momentum transport, such as the global momentum confinement time and local diffusivities. Studies of the mechanical angular momentum in ELMing H-mode plasmas with elevated q{sub min} show that the momentum confinement time improves as the torque is reduced. In hybrid plasmas, the opposite effect is observed, namely that momentum confinement improves at high torque/rotation. The relative importance of E x B shearing between the two is modeled using GLF23 and may suggest a possible explanation.

  4. Analysis of polycyclic aromatic hydrocarbons in aqueous samples by large volume injection gas chromatography-mass spectrometry using the through oven transfer adsorption desorption interface.

    PubMed

    Aragón, Álvaro; Toledano, Rosa M; Vázquez, Ana; Villén, Jesús; Cortés, José M

    2015-07-01

    A new procedure for the determination of 17 polycyclic aromatic hydrocarbons (PAHs) in aqueous samples by large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS) using the Through Oven Transfer Adsorption Desorption (TOTAD) interface with nitrogen for solvent elimination is developed and validated. Up to 75mL of aqueous samples were injected to be sure that good solvent elimination were achieved, although 500µL were sufficient to achieve the required sensitivity.The performance of the developed method can be considered good: the relative standard deviation (RSD), (n=3) was lower than 13.8% for all the target analytes, the concentration of each PAH being 0.25?gL(-1), the limit of detection and limit of quantitation ranged from 21.5 to 211.0?ng?L(-1) and from 71.7 to 703.3ngL(-1) respectively, and the correlation coefficients (R(2)) were all higher than 0.9764 in the 1-16?gL(-1) range. PMID:25882400

  5. Evidence for the Role of Horizontal Transfer in Generating pVT1, a Large Mosaic Conjugative Plasmid from the Clam Pathogen, Vibrio tapetis

    PubMed Central

    Bidault-Toffin, Adeline; Le Chevalier, Patrick; Bouloc, Philippe; Paillard, Christine; Jacq, Annick

    2011-01-01

    The marine bacterium Vibrio tapetis is the causative agent of the brown ring disease, which affects the clam Ruditapes philippinarum and causes heavy economic losses in North of Europe and in Eastern Asia. Further characterization of V. tapetis isolates showed that all the investigated strains harbored at least one large plasmid. We determined the sequence of the 82,266 bp plasmid pVT1 from the CECT4600T reference strain and analyzed its genetic content. pVT1 is a mosaic plasmid closely related to several conjugative plasmids isolated from Vibrio vulnificus strains and was shown to be itself conjugative in Vibrios. In addition, it contains DNA regions that have similarity with several other plasmids from marine bacteria (Vibrio sp., Shewanella sp., Listonella anguillarum and Photobacterium profundum). pVT1 contains a number of mobile elements, including twelve Insertion Sequences or inactivated IS genes and an RS1 phage element related to the CTXphi phage of V. cholerae. The genetic organization of pVT1 underscores an important role of horizontal gene transfer through conjugative plasmid shuffling and transposition events in the acquisition of new genetic resources and in generating the pVT1 modular organization. In addition, pVT1 presents a copy number of 9, relatively high for a conjugative plasmid, and appears to belong to a new type of replicon, which may be specific to Vibrionaceae and Shewanelleacae. PMID:21326607

  6. Convective momentum transport over the Tropical Pacific

    NASA Astrophysics Data System (ADS)

    Carr, Matthew Tobias

    2001-11-01

    The vertical transport of horizontal momentum by cumulus convection is investigated in observations and model simulations of the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE). Estimates of convective momentum transport (CMT) are obtained from the COARE momentum budget, aircraft dual-Doppler radar observations, cloud-resolving models, and CMT parameterizations. The role of CMIT in the large- scale circulation of the tropical Pacific is examined in the process. Budget estimates of CMT are shown to be highly uncertain, with no detectable signature of CMT above 850 mb. Below 850 mb, there is a slight tendency for downgradient transport. The pressure term is the major source of uncertainty in the budget. Radar CMT estimates are also only marginally significant, but show a tendency for countergradient transport above the time-mean low-level westerly jet. Countergradient transport is enhanced during westerly wind bursts, suggesting a role for CMT in the evolution of the Madden-Julian Oscillation. Convective updrafts accomplish nearly all of the CMT observed by the radars. A high-resolution 3D mesoscale model simulation of the December westerly wind burst also indicates the presence of countergradient transport by convective updrafts above the low-level jet. Momentum transport in the mesoscale model is much larger than either observational estimate, however. Differences in magnitude between the mesoscale model and the radar observations are attributed to the inability of the radar to adequately resolve vertical velocity features. The global model parameterization of Gregory et al. shows reasonable agreement with the mesoscale model at upper levels, but does not produce the countergradient layer above the low-level jet, suggesting the need for modification of simple mass flux representations of CMT. Further high-resolution modeling efforts are recommended.

  7. Strain and Stress in nano-structure spintronics devices due to spin transfer torque

    Microsoft Academic Search

    Hao Yu; Jun-Ming Liu

    2007-01-01

    There have been many interests of the effect of magnetization reversal induced by current in spintronics, namely, spin transfer or spin torque effect, firstly predicted by Slonczewski and Berger in 1996. Because of the conservation of angular momentum in the spin transfer process, an additional lattice angular momentum has to be brought to balance the redundant angular momentum of the

  8. Mantises Exchange Angular Momentum between Three Rotating Body Parts to Jump Precisely to Targets.

    PubMed

    Burrows, Malcolm; Cullen, Darron A; Dorosenko, Marina; Sutton, Gregory P

    2015-03-16

    Flightless animals have evolved diverse mechanisms to control their movements in air, whether falling with gravity or propelling against it. Many insects jump as a primary mode of locomotion and must therefore precisely control the large torques generated during takeoff. For example, to minimize spin (angular momentum of the body) at takeoff, plant-sucking bugs apply large equal and opposite torques from two propulsive legs [1]. Interacting gear wheels have evolved in some to give precise synchronization of these legs [2, 3]. Once airborne, as a result of either jumping or falling, further adjustments may be needed to control trajectory and orient the body for landing. Tails are used by geckos to control pitch [4, 5] and by Anolis lizards to alter direction [6, 7]. When falling, cats rotate their body [8], while aphids [9] and ants [10, 11] manipulate wind resistance against their legs and thorax. Falling is always downward, but targeted jumping must achieve many possible desired trajectories. We show that when making targeted jumps, juvenile wingless mantises first rotated their abdomen about the thorax to adjust the center of mass and thus regulate spin at takeoff. Once airborne, they then smoothly and sequentially transferred angular momentum in four stages between the jointed abdomen, the two raptorial front legs, and the two propulsive hind legs to produce a controlled jump with a precise landing. Experimentally impairing abdominal movements reduced the overall rotation so that the mantis either failed to grasp the target or crashed into it head first. PMID:25754643

  9. How did venus lose its angular momentum?

    PubMed

    Singer, S F

    1970-12-11

    Venus now has a retrograde and negligible spin, but it very likely started with a typical planetary spin: prograde and with a 10- to 20-hour period. The usually assumed mechanism of solar tidal friction is quite insufficient to remove this angular momentum. Instead, we postulate capture of a moonlike object from an initially retrograde orbit: it would despin Venus and suddenly transform the planet's rotational kinetic energy into internal heat, which would lead to volcanism and the liberation of large amounts of volatiles. The moon would disappear by crashing into the surface of Venus. PMID:17744051

  10. Quark Spin and Orbital Angular Momentum in the Baryon

    E-print Network

    X. Song

    2000-08-11

    The spin and orbital angular momentum carried by different quark flavors in the nucleon are calculated in the SU(3) chiral quark model with symmetry-breaking. The model is extended to all octet and decuplet baryons. In this model, the reduction of the quark spin, due to the spin dilution in the chiral splitting processes, is transferred into the orbital motion of quarks and antiquarks. The orbital angular momentum for each quark flavor in the proton as function of the partition factor $\\kappa$ and the chiral splitting probability $a$ is shown. Although the total amount of the quark spin reduction is canceled by the the equal amount increase of the quark orbital angular momentum, the cancellation does not apply to each quark flavor. Especially, the cancellation between the spin and orbital contributions in the baryon magnetic moment is discussed. Comparisons of our results with other models are also shown.

  11. Angular momentum evolution during star and planetary system formation

    NASA Astrophysics Data System (ADS)

    Davies, Claire L.; Greaves, Jane S.

    2014-01-01

    We focused on analysing the role played by protoplanetary disks in the evolution of angular momentum during star formation. If all the angular momentum contained within collapsing pre-stellar cores was conserved during their formation, proto-stars would reach rotation rates exceeding their break-up velocities before they reached the main sequence (Bodenheimer 1995). In order to avoid this occuring, methods by which proto-stars can lose angular momentum must exist. Angular momentum can be transferred from star to disk via stellar magnetic field lines through a process called magnetic braking (Camenzind 1990; Königl 1991). Alternatively, the stellar angular momentum can be lost from the star-disk system entirely via stellar- or disk-winds (e.g. Pelletier & Pudritz 1992; Matt & Pudritz 2005). The proportion of lost stellar angular momentum retained within the protoplanetary disk is important to studies of planetary system formation. If the bulk motion within the disk remains Keplerian, any increase of angular momentum in the disk causes an outward migration of disk material and an expansion of the disk. Therefore, an increase in disk angular momentum may cause a reduction in the disk surface density, often used to indicate the disk's ability to form planets. We made use of multi-wavelength data available in the literature to directly calculate the stellar and disk angular momenta for two nearby regions of star formation. Namely, these were the densely populated and highly irradiated Orion Nebula Cluster (ONC) and the comparitively sparse Taurus-Auriga region. Due to the limited size of the ONC dataset, we produced an average surface density profile for the region. We modelled the stars as solid body rotators due to their fully convective nature (Krishnamurthi et al. 1997) and assumed the disks are flat and undergo Keplerian rotation about the same rotation axis as the star. We observed the older disks within each of the two star forming regions to be preferentially larger and less massive, consistent with viscous accretion theories and disk dispersal. However, when drawing comparisons between the two regions, the ONC sample appeared to have less massive disks than the Taurus-Auriga sample, even though the population of Taurus-Auriga is older. This may suggest an influence of the birth cloud environment on protoplanetary disk evolution. Finally, the older stars within the ONC were observed to harbour disks that contained more angular momentum than their younger counterparts whereas, in the Taurus-Auriga sample, the amount of angular momentum contained in the older and younger samples was consistent. We suggest that the missing disk angular momentum in the older Taurus-Auriga disks may be contained within yet-undetected planets.

  12. Momentum determination via multiple scattering in AQUA-RICH

    NASA Astrophysics Data System (ADS)

    Grossheim, A.; Zuber, K.

    2004-11-01

    We present a new technique to measure the momentum of charged particles in a large ring imaging water-Cherenkov-detector (AQUA-RICH). Since Cherenkov photons are emitted with respect to the momentum vector of the particle, they are used to determine the particle direction with an angular resolution of a few mrad, making the deflections due to multiple scattering accessible. Considering the momentum dependence of multiple scattering, the distribution of scattering angles of a single particle can be used to determine its momentum. The performance of this method is tested in Monte Carlo simulation runs with muons in the range 4-24 GeV/ c and pathlengths of 10 m. Including all known error sources, resolutions of 11% (4 GeV/ c) to 21% (24 GeV/ c) are achievable. Longer tracks improve the accuracy significantly up to 4% (18 GeV/ c, 80 m).

  13. INTERNAL GRAVITY WAVES IN MASSIVE STARS: ANGULAR MOMENTUM TRANSPORT

    SciTech Connect

    Rogers, T. M. [Department of Planetary Sciences, University of Arizona, Tucson, AZ 85719 (United States); Lin, D. N. C. [Astronomy and Astrophysics Department, University of California, Santa Cruz, CA 95064 (United States); McElwaine, J. N. [Swiss Federal Institute for Snow and Avalanche Research, 11 Fluelastrasse, Davos Dorf (Switzerland); Lau, H. H. B., E-mail: tami@lpl.arizona.edu, E-mail: lin@ucolick.org, E-mail: james.mcelwaine@slf.ch, E-mail: hblau@astro.uni-bonn.de [Argelander-Institut for Astronomie, Universit Bonn Auf dem Huegel 71, D-53121 Bonn (Germany)

    2013-07-20

    We present numerical simulations of internal gravity waves (IGW) in a star with a convective core and extended radiative envelope. We report on amplitudes, spectra, dissipation, and consequent angular momentum transport by such waves. We find that these waves are generated efficiently and transport angular momentum on short timescales over large distances. We show that, as in Earth's atmosphere, IGW drive equatorial flows which change magnitude and direction on short timescales. These results have profound consequences for the observational inferences of massive stars, as well as their long term angular momentum evolution. We suggest IGW angular momentum transport may explain many observational mysteries, such as: the misalignment of hot Jupiters around hot stars, the Be class of stars, Ni enrichment anomalies in massive stars, and the non-synchronous orbits of interacting binaries.

  14. Momentum dissipation and effective theories of coherent and incoherent transport

    NASA Astrophysics Data System (ADS)

    Davison, Richard A.; Goutéraux, Blaise

    2015-01-01

    We study heat transport in two systems without momentum conservation: a hydrodynamic system, and a holographic system with spatially dependent, massless scalar fields. When momentum dissipates slowly, there is a well-defined, coherent collective excitation in the AC heat conductivity, and a crossover between sound-like and diffusive transport at small and large distance scales. When momentum dissipates quickly, there is no such excitation in the incoherent AC heat conductivity, and diffusion dominates at all distance scales. For a critical value of the momentum dissipation rate, we compute exact expressions for the Green's functions of our holographic system due to an emergent gravitational self-duality, similar to electric/magnetic duality, and SL(2, ) symmetries. We extend the coherent/incoherent classification to examples of charge transport in other holographic systems: probe brane theories and neutral theories with non-Maxwell actions.

  15. Momentum dissipation and effective theories of coherent and incoherent transport

    E-print Network

    Richard A. Davison; Blaise Goutéraux

    2015-01-21

    We study heat transport in two systems without momentum conservation: a hydrodynamic system, and a holographic system with spatially dependent, massless scalar fields. When momentum dissipates slowly, there is a well-defined, coherent collective excitation in the AC heat conductivity, and a crossover between sound-like and diffusive transport at small and large distance scales. When momentum dissipates quickly, there is no such excitation in the incoherent AC heat conductivity, and diffusion dominates at all distance scales. For a critical value of the momentum dissipation rate, we compute exact expressions for the Green's functions of our holographic system due to an emergent gravitational self-duality, similar to electric/magnetic duality, and SL(2,R) symmetries. We extend the coherent/incoherent classification to examples of charge transport in other holographic systems: probe brane theories and neutral theories with non-Maxwell actions.

  16. Interannual variations in degree-2 Earth's gravity coefficients C2,0, C2,2, and S2,2 reveal large-scale mass transfers of climatic origin

    NASA Astrophysics Data System (ADS)

    Meyssignac, B.; Lemoine, J. M.; Cheng, M.; Cazenave, A.; GéGout, P.; Maisongrande, P.

    2013-08-01

    Several recent studies have shown evidences for large water transfers in the climate system at interannual to decadal time scales, in particular during El Niño-Southern Oscillation events. In this study, we investigate further these water transfers and their signature in the gravity field. We analyze variations of the low-degree spherical harmonics C2,0 (Earth's oblateness), C2,2, and S2,2 (eccentricity at the Earth's equator) from satellite laser ranging data during the 19 year period 1993-2012. We also estimate the water mass transfers in the climate system using satellite altimetry corrected for the steric effect, atmospheric reanalysis, and land hydrology models. We find a large signal in the water mass redistribution during the 1997/1998 El Niño which is consistent with an increase of the ocean mass in the tropical Pacific, a decrease of water storage in the Amazon Basin, and an increase of water storage in the Congo Basin.

  17. Momentum Injection by Supernovae in the Interstellar Medium

    NASA Astrophysics Data System (ADS)

    Kim, Chang-Goo; Ostriker, Eve C.

    2015-04-01

    Supernova (SN) explosions deposit prodigious energy and momentum in their environments, with the former regulating multiphase thermal structure and the latter regulating turbulence and star formation rates in the interstellar medium (ISM). However, systematic studies quantifying the impact of SNe in realistic inhomogeneous ISM conditions have been lacking. Using three-dimensional hydrodynamic simulations, we investigate the dependence of radial momentum injection on both physical conditions (considering a range of mean density n0 = 0.1–100 c{{m}-3}) and numerical parameters. Our inhomogeneous simulations adopt two-phase background states that result from thermal instability in atomic gas. Although the supernova remnant (SNR) morphology becomes highly complex for inhomogeneous backgrounds, the radial momentum injection is remarkably insensitive to environmental details. For our two-phase simulations, the final momentum produced by a single SN is given by 2.8× {{10}5} {{M}? } km {{s}-1}n0-0.17. This is only 5% less than the momentum injection for a homogeneous environment with the same mean density, and only 30% greater than the momentum at the time of shell formation. The maximum mass in hot gas is also quite insensitive to environmental inhomogeneity. Strong magnetic fields alter the hot gas mass at very late times, but the momentum injection remains the same. Initial experiments with multiple spatially correlated SNe show a momentum per event nearly as large as single-SN cases. We also present a full numerical parameter study to assess convergence requirements. For convergence in the momentum and other quantities, we find that the numerical resolution ? and the initial size of the SNR {{r}init} must satisfy {? },{{r}init}\\lt {{r}sf}/3, where the shell formation radius is given by {{r}sf}=30 pc n0-0.46 for two-phase models (or 30% smaller for a homogeneous medium).

  18. VOLUME 82, NUMBER 10 P H Y S I C A L R E V I E W L E T T E R S 8 MARCH 1999 Inclusive Electron-Nucleus Scattering at Large Momentum Transfer

    E-print Network

    Thomas Jefferson National Accelerator Facility

    . de Bever,1 C. W. Bochna,5 W. Boeglin,3 B. Bray,2 R. D. Carlini,9 G. Collins,6 C. Cothran,10 D. Crabb. Petitjean,1 O. Rondon,10 I. Sick,1 C. Smith,10 B. Terburg,5 W. F. Vulcan,9 S. A. Wood,9 C. Yan,9 J. Zhao,1VOLUME 82, NUMBER 10 P H Y S I C A L R E V I E W L E T T E R S 8 MARCH 1999 Inclusive Electron

  19. Turbulent Transport of Momentum and Scalars Above an Urban Canopy

    NASA Astrophysics Data System (ADS)

    Wang, Linlin; Li, Dan; Gao, Zhiqiu; Sun, Ting; Guo, Xiaofeng; Bou-Zeid, Elie

    2014-03-01

    Turbulent transport of momentum and scalars over an urban canopy is investigated using the quadrant analysis technique. High-frequency measurements are available at three levels above the urban canopy (47, 140 and 280 m). The characteristics of coherent ejection-sweep motions (flux contributions and time fractions) at the three levels are analyzed, particularly focusing on the difference between ejections and sweeps, the dissimilarity between momentum and scalars, and the dissimilarity between the different scalars (i.e., temperature, water vapour and . It is found that ejections dominate momentum and scalar transfer at all three levels under unstable conditions, while sweeps are the dominant eddy motions for transporting momentum and scalars in the urban roughness sublayer under neutral and stable conditions. The flux contributions and time fractions of ejections and sweeps can be adequately captured by assuming a Gaussian joint probability density function for flow variables. However, the inequality of flux contributions from ejections and sweeps is more accurately reproduced by the third-order cumulant expansion method (CEM). The incomplete cumulant expansion method (ICEM) also works well except for at 47 m where the skewness of fluctuations is significantly larger than that for vertical velocity. The dissimilarity between momentum and scalar transfers is linked to the dissimilarity in the characteristics of ejection-sweep motions and is further quantified by measures of transport efficiencies. Atmospheric stability is the controlling factor for the transport efficiencies of momentum and heat, and fitted functions from the literature describe their behaviour fairly accurately. However, transport efficiencies of water vapour and are less affected by the atmospheric stability. The dissimilarity among the three scalars examined in this study is linked to the active role of temperature and to the surface heterogeneity effect.

  20. Arbitrary Coherent Superpositions of Quantized Vortices in Bose-Einstein Condensates from Orbital Angular Momentum Beams of Light

    E-print Network

    Sulakshana Thanvanthri; Kishore T. Kapale; Jonathan P. Dowling

    2008-03-18

    We recently proposed a scheme for the creation of coherent superpositions of vortex states in Bose-Einstein condensates (BEC) using orbital angular momentum (OAM) states of light [Phys. Rev. Lett. 95, 173601 (2005)]. Here we discuss further technical details of the proposal, provide alternative, time-reversal-symmetric scheme for transfer of a superposition of OAM states of light to the BEC via a procedure analogous to the traditional STimulated Raman Adiabatic Passage (STIRAP) technique, and discuss an alternative trap configuration conducive for sustaining large charge vortices. Superpositions of OAM states of light, created using experimental techniques, can be transfered to an initially nonrotating BEC via a specially devised Raman coupling scheme. The techniques proposed here open up avenues to study coherent interaction of OAM states of light with matter. The study could also be employed for performing various quantum information processing tasks with OAM states of light--including a memory for a quantum state of the initial superposition.

  1. Spin Angular Momentum Imparted by Gravitational Waves

    E-print Network

    M Sharif

    2007-01-23

    Following the demonstration that gravitational waves impart linear momentum, it is argued that if they are polarized they should impart angular momentum to appropriately placed 'test rods' in their path. A general formula for this angular momentum is obtained and used to provide expressions for the angular momentum imparted by plane and cylindrical gravitational waves.

  2. Paraxial Light Beams with Angular Momentum

    Microsoft Academic Search

    A. Bekshaev; M. Soskin; M. Vasnetsov

    2008-01-01

    Fundamental and applied concepts concerning the ability of light beams to carry a certain mechanical angular momentum with respect to the propagation axis are reviewed and discussed. Following issues are included: Historical reference; Angular momentum of a paraxial beam and its constituents; Spin angular momentum and paradoxes associated with it; Orbital angular momentum; Circularly-spiral beams: examples and methods of generation;

  3. Plasmons with orbital angular momentum

    SciTech Connect

    Mendonca, J. T. [IPFN, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Ali, S. [IPFN, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); National Centre for Physics, Shahdra Valley Road, Islamabad 44000 (Pakistan); Thide, B. [Swedish Institute of Space Physics, Angstroem Laboratory, P.O. Box 537, SE-751 21 Uppsala (Sweden)

    2009-11-15

    Electron plasma waves carrying orbital angular momentum are investigated in an unmagnetized collisionless plasma composed of inertial electrons and static ions. For this purpose, the usual plasmon dispersion relation is employed to derive an approximate paraxial equation. The latter is analyzed with a Gaussian beam solution. For a finite angular momentum associated with the plasmon, Laguerre-Gaussian (LG) solutions are employed for solving the electrostatic potential problem which gives approximate solution and is valid for plasmon beams in the paraxial approximation. The LG potential determines the electric field components and energy flux of plasmons with finite angular momentum. Numerical illustrations show that the radial and angular mode numbers strongly modify the profiles of the LG potential.

  4. Variations in atmospheric angular momentum

    NASA Technical Reports Server (NTRS)

    Rosen, R. D.; Salstein, D. A.

    1981-01-01

    Twice-daily values of the atmosphere's angular momentum about the polar axis during the five years from 1976 through 1980 are presented in graphs and a table. The compilation is based on a global data set, incorporating 90 percent of the mass of the atmosphere. The relationship between changes in the angular momentum of the atmosphere and changes in the length of day is described, as are the main sources of error in the data. The variability in angular momentum is revealed in a preliminary fashion by means of a spectral decomposition. The data presented should stimulate comparisons with other measures of the length of day and so provide a basis for greater understanding of Earth-atmosphere interactions.

  5. Transfer form

    Cancer.gov

    10/02 Transfer Investigational Agent Form This form is to be used for an intra-institutional transfer, one transfer/form. Division of Cancer Prevention National Cancer Institute National Institutes of Health TRANSFER FROM: Investigator transferring agent:

  6. Quantized Rotation of Atoms from Photons with Orbital Angular Momentum

    Microsoft Academic Search

    M. F. Andersen; C. Ryu; Pierre Cladé; Vasant Natarajan; A. Vaziri; K. Helmerson; W. D. Phillips

    2006-01-01

    We demonstrate the coherent transfer of the orbital angular momentum of a photon to an atom in quantized units of ℏ, using a 2-photon stimulated Raman process with Laguerre-Gaussian beams to generate an atomic vortex state in a Bose-Einstein condensate of sodium atoms. We show that the process is coherent by creating superpositions of different vortex states, where the relative

  7. Single beam optical vortex tweezers with tunable orbital angular momentum

    SciTech Connect

    Gecevi?ius, Mindaugas; Drevinskas, Rokas, E-mail: rd1c12@orc.soton.ac.uk; Beresna, Martynas; Kazansky, Peter G. [Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ (United Kingdom)

    2014-06-09

    We propose a single beam method for generating optical vortices with tunable optical angular momentum without altering the intensity distribution. With the initial polarization state varying from linear to circular, we gradually control the torque transferred to the trapped non-absorbing and non-birefringent silica beads. The continuous transition from the maximum rotation speed to zero without changing the trapping potential gives a way to study the complex tribological interactions.

  8. Polarization control of single photon quantum orbital angular momentum states

    E-print Network

    E. Nagali; F. Sciarrino; F. De Martini; B. Piccirillo; E. Karimi; L. Marrucci; E. Santamato

    2009-02-04

    The orbital angular momentum of photons, being defined in an infinitely dimensional discrete Hilbert space, offers a promising resource for high-dimensional quantum information protocols in quantum optics. The biggest obstacle to its wider use is presently represented by the limited set of tools available for its control and manipulation. Here, we introduce and test experimentally a series of simple optical schemes for the coherent transfer of quantum information from the polarization to the orbital angular momentum of single photons and vice versa. All our schemes exploit a newly developed optical device, the so-called "q-plate", which enables the manipulation of the photon orbital angular momentum driven by the polarization degree of freedom. By stacking several q-plates in a suitable sequence, one can also access to higher-order angular momentum subspaces. In particular, we demonstrate the control of the orbital angular momentum $m$ degree of freedom within the subspaces of $|m|=2 \\hbar$ and $|m|=4\\hbar$ per photon. Our experiments prove that these schemes are reliable, efficient and have a high fidelity.

  9. Linear Momentum and Angular-Momentum Transfer in the Reactions of O-16 with Sm-154

    E-print Network

    Namboodiri, M. N.; Choudhury, R. K.; Alder, L.; Bronson, J. D.; Fabris, D.; Garg, U.; Gonthier, P. L.; Hagel, K.; Haenni, DR; Lui, YW; Majka, Z.; Mouchaty, G.; Murakami, T.; Natowitz, J. B.; Nebbia, G.; Schmitt, R. P.; Simon, S.; Sullivan, J. P.; Youngblood, David H.

    1987-01-01

    address: University of Washington, Seattle, WA 98195. V. E. Viola, B. B. Back, K. L. Wolf, T. C. Awes, C. K. Gelbke, and H. Breuer, Phys. Rev. C 26, 178 (1982). 2H. Morgenstern, W. Bohne, K. Grabisch, D. G. Kovar, and H. Lehr, Phys. Lett. 113B, 463.... Natowitz, L. Adler, S. Simon, K. Hagel, S. Kniffen, and A. Khodai, Nucl. Phys. A411, 289 (1983). B. B. Back, K. L. Wolf, A. C. Mignerey, C. K. Gelbke, T. C. Awes, H. Breuer, V. E. Viola, and P. Dyer, Phys. Rev. C 22, 1927 (1980). 160 M. N. NAMBOODIRI...

  10. Induction and Persistence of Large ?H2AX Foci by High Linear Energy Transfer Radiation in DNA-Dependent protein kinase–Deficient Cells

    SciTech Connect

    Bracalente, Candelaria; Ibañez, Irene L. [Departamento de Micro y Nanotecnología, Comisión Nacional de Energía Atómica, San Martín, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires (Argentina); Molinari, Beatriz [Departamento de Radiobiología, Comisión Nacional de Energía Atómica, San Martín, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires (Argentina); Palmieri, Mónica [Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires (Argentina); Kreiner, Andrés [Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires (Argentina); Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica, San Martín, Buenos Aires (Argentina); Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín, San Martín, Buenos Aires (Argentina); Valda, Alejandro [Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín, San Martín, Buenos Aires (Argentina); and others

    2013-11-15

    Purpose: To evaluate the cell response to DNA double-strand breaks induced by low and high linear energy transfer (LET) radiations when the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), an essential protein of the nonhomologous end-joining repair pathway, lacks kinase activity. Methods and Materials: CHO10B2, a Chinese hamster ovary cell line, and its derived radiosensitive mutant cell line, irs-20, lacking DNA-PKcs activity, were evaluated after 0 to 3 Gy of ?-rays, plateau and Bragg peak protons, and lithium beams by clonogenic assay, and as a measurement of double-strand breaks, phosphorylated H2AX (?H2AX) foci number and size were quantified by immunocytofluorescence. Results: Irs-20 exhibited greater radiosensitivity and a higher amount of ?H2AX foci than CHO10B2 at 6 hours after irradiation for all types of radiations. Remarkably, CHO10B2 and irs-20 maintained their difference in radiosensitivity after high-LET radiation. Six hours after low-LET radiations, irs-20 did not reach basal levels of ?H2AX at high doses, whereas CHO10B2 recovered basal levels for all doses. After high-LET radiation, only CHO10B2 exhibited a reduction in ?H2AX foci, but it never reached basal levels. Persistent foci in irs-20 confirmed a repair deficiency. Interestingly, after 30 minutes of high-LET radiation both cell lines exhibited large foci (size >0.9 ?m{sup 2}) related to the damage nature, whereas at 6 hours irs-20 showed a higher amount of large foci than CHO10B2, with a 7-fold increase at 3 Gy, that could also be associated to radiosensitivity. Conclusions: We demonstrated, for the first time, an association between deficient DNA-PKcs activity and not only high levels of H2AX phosphorylation but also persistence and size increase of ?H2AX foci after high-LET irradiation.

  11. The Angular Momentum of Baryons and Dark Matter Halos Revisited

    NASA Technical Reports Server (NTRS)

    Kimm, Taysun; Devriendt, Julien; Slyz, Adrianne; Pichon, Christophe; Kassin, Susan A.; Dubois, Yohan

    2011-01-01

    Recent theoretical studies have shown that galaxies at high redshift are fed by cold, dense gas filaments, suggesting angular momentum transport by gas differs from that by dark matter. Revisiting this issue using high-resolution cosmological hydrodynamics simulations with adaptive-mesh refinement (AMR), we find that at the time of accretion, gas and dark matter do carry a similar amount of specific angular momentum, but that it is systematically higher than that of the dark matter halo as a whole. At high redshift, freshly accreted gas rapidly streams into the central region of the halo, directly depositing this large amount of angular momentum within a sphere of radius r = 0.1R(sub vir). In contrast, dark matter particles pass through the central region unscathed, and a fraction of them ends up populating the outer regions of the halo (r/R(sub vir) > 0.1), redistributing angular momentum in the process. As a result, large-scale motions of the cosmic web have to be considered as the origin of gas angular momentum rather than its virialised dark matter halo host. This generic result holds for halos of all masses at all redshifts, as radiative cooling ensures that a significant fraction of baryons remain trapped at the centre of the halos. Despite this injection of angular momentum enriched gas, we predict an amount for stellar discs which is in fair agreement with observations at z=0. This arises because the total specific angular momentum of the baryons (gas and stars) remains close to that of dark matter halos. Indeed, our simulations indicate that any differential loss of angular momentum amplitude between the two components is minor even though dark matter halos continuously lose between half and two-thirds of their specific angular momentum modulus as they evolve. In light of our results, a substantial revision of the standard theory of disc formation seems to be required. We propose a new scenario where gas efficiently carries the angular momentum generated by large-scale structure motions deep inside dark matter halos, redistributing it only in the vicinity of the disc.

  12. Spin-transfer pulse switching: From the dynamic to the thermally activated regime

    NASA Astrophysics Data System (ADS)

    Bedau, D.; Liu, H.; Sun, J. Z.; Katine, J. A.; Fullerton, E. E.; Mangin, S.; Kent, A. D.

    2010-12-01

    The effect of thermal fluctuations on spin-transfer switching has been studied for a broad range of time scales (subnanoseconds to seconds) in a model system, a uniaxial thin film nanomagnet. The nanomagnet is incorporated into a spin-valve nanopillar, which is subject to spin-polarized current pulses of variable amplitude and duration. Two physical regimes are clearly distinguished: a long pulse duration regime, in which reversal occurs by spin-transfer assisted thermal activation over an energy barrier, and a short-time large pulse amplitude regime, in which the switching probability is determined by the spin-angular momentum in the current pulse.

  13. Observations of ionospheric convection vortices - Signatures of momentum transfer

    NASA Technical Reports Server (NTRS)

    Mchenry, M. A.; Clauer, C. R.; Friis-Christensen, E.; Kelly, J. D.

    1988-01-01

    Several classes of traveling vortices in the dayside ionospheric flow have been detected and tracked using the Greenland magnetometer chain. One class observed during quiet times consists of a continuous series of vortices moving generally antisunward for several hours at a time. Assuming each vortex to be the convection pattern produced by a small field aligned current moving across the ionosphere, the amount of field aligned current was found by fitting a modeled ground magnetic signature to measurements from the chain of magnetometers. The calculated field aligned current is seen to be steady for each vortex and neighboring vortices have currents of opposite sign. Low altitude DMSP observations indicate the vortices are on field lines which map to the inner edge of the low latitude boundary layer. Because the vortices are conjugate to the boundary layer, repeat in a regular fashion and travel antisunward, it is argued that this class of vortices is caused by surface waves at the magnetopause. No strong correlations between field aligned current strength and solar wind density, velocity, or Bz is found.

  14. Momentum Transfer by Laser Ablation of Irregularly Shaped Space Debris

    SciTech Connect

    Liedahl, Duane A.; Libby, Stephen B.; Rubenchik, Alexander [Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550 (United States)

    2010-10-08

    Proposals for ground-based laser remediation of space debris rely on the creation of appropriately directed ablation-driven impulses to either divert the fragment or drive it into an orbit with a perigee allowing atmospheric capture. For a spherical fragment, the ablation impulse is a function of the orbital parameters and the laser engagement angle. If, however, the target is irregularly shaped and arbitrarily oriented, new impulse effects come into play. Here we present an analysis of some of these effects.

  15. Momentum Transfer by Laser Ablation of Irregularly Shaped Space Debris

    SciTech Connect

    Liedahl, D A; Libby, S B; Rubenchik, A

    2010-02-04

    Proposals for ground-based laser remediation of space debris rely on the creation of appropriately directed ablation-driven impulses to either divert the fragment or drive it into an orbit with a perigee allowing atmospheric capture. For a spherical fragment, the ablation impulse is a function of the orbital parameters and the laser engagement angle. If, however, the target is irregularly shaped and arbitrarily oriented, new impulse effects come into play. Here we present an analysis of some of these effects.

  16. Plasma detachment and momentum transfer in magnetic nozzles

    E-print Network

    Choueiri, Edgar

    the accelerated propellant to the structure of the magnetic nozzle. Thrust transmission in a conventional rocket is achieved through pressure forces acting on the solid surfaces of the propellant injector, combustor, and nozzle (Figure 1(a)). A magnetic rocket, on the other hand, is not guaranteed to have any solid surfaces

  17. Teaching about Impulse and Momentum

    ERIC Educational Resources Information Center

    Franklin, Bill

    2004-01-01

    This American Association of Physics Teachers/Physics Teaching Resource Agents (APPT/PTRA) spiral-bound manual features labs and demos physics teachers can use to give students hands-on opportunities to learn about impulse and momentum. "Make-and-take activities" include AAPT Apparatus Contest winners "An Air Impulse Rocket," "A Fan Driven…

  18. Electromagnetic Momentum, Energy, and Mass

    Microsoft Academic Search

    F. Rohrlich

    1970-01-01

    Electromagnetic systems of finite mass (m > 0) and of zero mass (m = 0) are considered. For both cases the electromagnetic energy and momentum are computed and are shown to lead to essentially different formulas. An invariant expression for the electromagnetic mass in m > 0 systems is derived. All m > 0 results are then specialized to the

  19. Di-jet asymmetric momentum transported by QGP fluid

    E-print Network

    Yasuki Tachibana; Tetsufumi Hirano

    2014-10-15

    We study the collective flow of the {QGP}-fluid which transports the energy and momentum deposited from jets. Simulations of the propagation of jets together with expansion of the {QGP}-fluid are performed by solving relativistic hydrodynamic equations numerically in the fully (3+1)-dimensional space. Mach cones are induced by the energy-momentum deposition from jets and extended by the expansion of the {QGP}. As a result, a large fraction of the transverse momentum deposited from jets is compensated by low-$p_{T}$ particles at large angles from the jet axis. This result is consistent with the data from the {CMS} Collaboration and gives a novel interpretation of them.

  20. Experimental investigation of free-convection heat transfer in vertical tube at large Grashof numbers / E. R. G. Eckert, A. J. Diaguila

    NASA Technical Reports Server (NTRS)

    Eckert, E R G; Diaguila, A J

    1952-01-01

    Local free-convection heat-transfer coefficients and temperature fields in the turbulent flow range were obtained within a vertical, stationary tube closed at the boom, heated along its walls, and having a length-to-diameter ratio of 5. Convective heat-transfer coefficients were correlated by the general relations for free-convection heat transfer. These coefficients, converted to dimensionless Nusselt numbers were 35 percent below known relations for vertical flat plates. Air temperature measurements within the tube indicated a thin boundary layer along the heated wall surface and unstable conditions in the air flow.

  1. Local heat-transfer measurements on a large, scale-model turbine blade airfoil using a composite of a heater element and liquid crystals

    NASA Technical Reports Server (NTRS)

    Hippensteele, S. A.; Russell, L. M.; Torres, F. J.

    1985-01-01

    Local heat transfer coefficients were experimentally mapped along the midchord of a five-time-size turbine blade airfoil in a static cascade operated at room temperature over a range of Reynolds numbers. The test surface consisted of a composite of commercially available materials: a mylar sheet with a layer of cholesteric liquid crystals, that change color with temperature, and a heater sheet made of a carbon-impregnated paper, that produces uniform heat flux. After the initial selection and calibration of the composite sheet, accurate, quantitative, and continuous heat transfer coefficients were mapped over the airfoil surface. The local heat transfer coefficients are presented for Reynolds numbers from 2.8 x 10 to the 5th power to 7.6 x 10 to the 5th power. Comparisons are made with analytical values of heat transfer coefficients obtained from the STAN5 boundary layer code. Also, a leading edge separation bubble was revealed by thermal and flow visualization.

  2. The effects of inlet turbulence and rotor/stator interactions on the aerodynamics and heat transfer of a large-scale rotating turbine model, volume 1

    NASA Technical Reports Server (NTRS)

    Dring, R. P.; Blair, M. F.; Joslyn, H. D.; Power, G. D.; Verdon, J. M.

    1987-01-01

    A combined experimental and analytical program was conducted to examine the effects of inlet turbulence on airfoil heat transfer. Heat transfer measurements were obtained using low conductivity airfoils with miniature thermocouples welded to a thin, electrically heated surface skin. Heat transfer data were acquired for various combinations of low or high inlet turbulence intensity, flow coefficient (incidence), first-stator/rotor axial spacing, Reynolds number, and relative circumferential position of the first and second stators. Aerodynamic measurements include distributions of the mean and fluctuating velocities at the turbine inlet and, for each airfoil row, midspan airfoil surface pressures and circumferential distributions of the downstream steady state pressures and fluctuating velocities. Analytical results include airfoil heat transfer predictions and a examination of solutions of the unstead boundary layer equipment.

  3. Momentum-space calculation of four-boson recombination

    E-print Network

    A. Deltuva

    2012-01-11

    The system of four identical bosons with large two-boson scattering length is described using momentum-space integral equations for the four-particle transition operators. The creation of Efimov trimers via ultracold four-boson recombination is studied. The universal behavior of the recombination rate is demonstrated.

  4. Plasmons in molecules: microscopic characterization based on orbital transitions and momentum conservation.

    PubMed

    Krauter, Caroline M; Schirmer, Jochen; Jacob, Christoph R; Pernpointner, Markus; Dreuw, Andreas

    2014-09-14

    In solid state physics, electronic excitations are often classified as plasmons or single-particle excitations. The former class of states refers to collective oscillations of the electron density. The random-phase approximation allows for a quantum-theoretical treatment and a characterization on a microscopic level as a coherent superposition of a large number of particle-hole transitions with the same momentum transfer. However, small systems such as molecules or small nanoclusters lack the basic properties (momentum conservation and uniform exchange interaction) responsible for the formation of plasmons in the solid-state case. Despite an enhanced interest in plasmon-based technologies and an increasing number of studies regarding plasmons in molecules and small nanoclusters, their definition on a microscopic level of theory remains ambiguous. In this work, we analyze the microscopic properties of molecular plasmons in comparison with the homogeneous electron gas as a model system. Subsequently, the applicability of the derived characteristics is validated by analyzing the electronic excitation vectors with respect to orbital transitions for two linear polyenes within second order versions of the algebraic diagrammatic construction scheme for the polarization propagator. PMID:25217898

  5. Plasmons in molecules: Microscopic characterization based on orbital transitions and momentum conservation

    SciTech Connect

    Krauter, Caroline M., E-mail: Caroline.Krauter@pci.uni-heidelberg.de [Theoretical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany); Interdisciplinary Center for Scientific Computing, Heidelberg University, Im Neuenheimer Feld 368, 69120 Heidelberg (Germany); Schirmer, Jochen; Pernpointner, Markus [Theoretical Chemistry, Heidelberg University, Im Neuenheimer Feld 229, D-69120 Heidelberg (Germany); Jacob, Christoph R. [Center for Functional Nanostructures and Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1a, 76131 Karlsruhe (Germany); Dreuw, Andreas [Interdisciplinary Center for Scientific Computing, Heidelberg University, Im Neuenheimer Feld 368, 69120 Heidelberg (Germany)

    2014-09-14

    In solid state physics, electronic excitations are often classified as plasmons or single-particle excitations. The former class of states refers to collective oscillations of the electron density. The random-phase approximation allows for a quantum-theoretical treatment and a characterization on a microscopic level as a coherent superposition of a large number of particle-hole transitions with the same momentum transfer. However, small systems such as molecules or small nanoclusters lack the basic properties (momentum conservation and uniform exchange interaction) responsible for the formation of plasmons in the solid-state case. Despite an enhanced interest in plasmon-based technologies and an increasing number of studies regarding plasmons in molecules and small nanoclusters, their definition on a microscopic level of theory remains ambiguous. In this work, we analyze the microscopic properties of molecular plasmons in comparison with the homogeneous electron gas as a model system. Subsequently, the applicability of the derived characteristics is validated by analyzing the electronic excitation vectors with respect to orbital transitions for two linear polyenes within second order versions of the algebraic diagrammatic construction scheme for the polarization propagator.

  6. Förster-Induced Energy Transfer in Functionalized Graphene.

    PubMed

    Malic, Ermin; Appel, Heiko; Hofmann, Oliver T; Rubio, Angel

    2014-05-01

    Carbon nanostructures are ideal substrates for functionalization with molecules since they consist of a single atomic layer giving rise to an extraordinary sensitivity to changes in their surrounding. The functionalization opens a new research field of hybrid nanostructures with tailored properties. Here, we present a microscopic view on the substrate-molecule interaction in the exemplary hybrid material consisting of graphene functionalized with perylene molecules. First experiments on similar systems have been recently realized illustrating an extremely efficient transfer of excitation energy from adsorbed molecules to the carbon substrate, a process with a large application potential for high-efficiency photovoltaic devices and biomedical imaging and sensing. So far, there has been no microscopically founded explanation for the observed energy transfer. Based on first-principle calculations, we have explicitly investigated the different transfer mechanisms revealing the crucial importance of Förster coupling. Due to the efficient Coulomb interaction in graphene, we obtain strong Förster rates in the range of 1/fs. We investigate its dependence on the substrate-molecule distance R and describe the impact of the momentum transfer q for an efficient energy transfer. Furthermore, we find that the Dexter transfer mechanism is negligibly small due to the vanishing overlap between the involved strongly localized orbital functions. The gained insights are applicable to a variety of carbon-based hybrid nanostructures. PMID:24808936

  7. Förster-Induced Energy Transfer in Functionalized Graphene

    PubMed Central

    2014-01-01

    Carbon nanostructures are ideal substrates for functionalization with molecules since they consist of a single atomic layer giving rise to an extraordinary sensitivity to changes in their surrounding. The functionalization opens a new research field of hybrid nanostructures with tailored properties. Here, we present a microscopic view on the substrate–molecule interaction in the exemplary hybrid material consisting of graphene functionalized with perylene molecules. First experiments on similar systems have been recently realized illustrating an extremely efficient transfer of excitation energy from adsorbed molecules to the carbon substrate, a process with a large application potential for high-efficiency photovoltaic devices and biomedical imaging and sensing. So far, there has been no microscopically founded explanation for the observed energy transfer. Based on first-principle calculations, we have explicitly investigated the different transfer mechanisms revealing the crucial importance of Förster coupling. Due to the efficient Coulomb interaction in graphene, we obtain strong Förster rates in the range of 1/fs. We investigate its dependence on the substrate–molecule distance R and describe the impact of the momentum transfer q for an efficient energy transfer. Furthermore, we find that the Dexter transfer mechanism is negligibly small due to the vanishing overlap between the involved strongly localized orbital functions. The gained insights are applicable to a variety of carbon-based hybrid nanostructures. PMID:24808936

  8. Gravitational lenses with angular momentum

    NASA Astrophysics Data System (ADS)

    Ibanez, J.

    1983-08-01

    The Einstein (1936), Liebes (1964), Refsdal (1965), and Bourassa et al. (1973, 1975) theories of the effects of gravitational lenses have considered the bending of light as due to the mass distribution of the deflector. The effect of deflector dynamical properties has not been taken into account. The influence of angular momentum in a gravitational lens is presently demonstrated by the bending angle of a photon passing near a rotating body. The expressions used are evaluated for spherical and spheroidal deflectors.

  9. Axions and the galactic angular momentum distribution

    NASA Astrophysics Data System (ADS)

    Banik, N.; Sikivie, P.

    2013-12-01

    We analyze the behavior of axion dark matter before it falls into a galactic gravitational potential well. The axions thermalize sufficiently fast by gravitational self-interactions that almost all go to their lowest-energy state consistent with the total angular momentum acquired from tidal torquing. That state is a state of rigid rotation on the turnaround sphere. It predicts the occurrence and detailed properties of the caustic rings of dark matter for which observational evidence had been found earlier. We show that the vortices in the axion Bose-Einstein condensate (BEC) are attractive, unlike those in superfluid He4 and dilute gases. We expect that a large fraction of the vortices in the axion BEC join into a single big vortex along the rotation axis of the galaxy. The resulting enhancement of caustic rings explains the typical size of the rises in the Milky Way rotation curve attributed to caustic rings. We show that baryons and ordinary cold dark matter particles are entrained by the axion BEC and acquire the same velocity distribution. The resulting baryonic angular momentum distribution gives a good qualitative fit to the distributions observed in dwarf galaxies. We give estimates of the minimum fraction of dark matter that is composed of axions.

  10. A Simple Holographic Superconductor with Momentum Relaxation

    E-print Network

    Kim, Keun-Young; Park, Miok

    2015-01-01

    We study a holographic superconductor model with momentum relaxation due to massless scalar fields linear to spatial coordinates($\\psi_I = \\beta \\delta_{Ii} x^i$), where $\\beta$ is the strength of momentum relaxation. In addition to the original superconductor induced by the chemical potential($\\mu$) at $\\beta=0$, there exists a new type of superconductor induced by $\\beta$ even at $\\mu=0$. It may imply a new `pairing' mechanism of particles and antiparticles interacting with $\\beta$, which may be interpreted as `impurity'. Two parameters $\\mu$ and $\\beta$ compete in forming superconducting phase. As a result, the critical temperature behaves differently depending on $\\beta/\\mu$. It decreases when $\\beta/\\mu$ is small and increases when $\\beta/\\mu$ is large, which is a novel feature compared to other models. After analysing ground states and phase diagrams for various $\\beta/\\mu$, we study optical electric($\\sigma$), thermoelectric($\\alpha$), and thermal($\\bar{\\kappa}$) conductivities. When the system undergo...

  11. A Simple Holographic Superconductor with Momentum Relaxation

    E-print Network

    Keun-Young Kim; Kyung Kiu Kim; Miok Park

    2015-01-14

    We study a holographic superconductor model with momentum relaxation due to massless scalar fields linear to spatial coordinates($\\psi_I = \\beta \\delta_{Ii} x^i$), where $\\beta$ is the strength of momentum relaxation. In addition to the original superconductor induced by the chemical potential($\\mu$) at $\\beta=0$, there exists a new type of superconductor induced by $\\beta$ even at $\\mu=0$. It may imply a new `pairing' mechanism of particles and antiparticles interacting with $\\beta$, which may be interpreted as `impurity'. Two parameters $\\mu$ and $\\beta$ compete in forming superconducting phase. As a result, the critical temperature behaves differently depending on $\\beta/\\mu$. It decreases when $\\beta/\\mu$ is small and increases when $\\beta/\\mu$ is large, which is a novel feature compared to other models. After analysing ground states and phase diagrams for various $\\beta/\\mu$, we study optical electric($\\sigma$), thermoelectric($\\alpha$), and thermal($\\bar{\\kappa}$) conductivities. When the system undergoes a phase transition from normal to a superconducting phase, $1/\\omega$ pole appears in the imaginary part of the electric conductivity, implying infinite DC conductivity. If $\\beta/\\mu 1$ a non-Drude peak replaces the Drude peak. It is consistent with the coherent/incoherent metal transition in its metal phase. The Ferrell-Glover-Tinkham (FGT) sum rule is satisfied for all cases even when $\\mu=0$.

  12. Coherent Transport of Angular Momentum - The Ranque-Hilsch Tube as a Paradigm

    Microsoft Academic Search

    Stirling A. Colgate; J. Robert Buchler

    1999-01-01

    The mechanism for efficient and coherent angular momentum transport remains\\u000aone of the unsolved puzzles in astrophysics despite the enormous efforts that\\u000ahave been made. We suggest that important new insight could be gained in this\\u000aproblem through an experimental and theoretical study of a laboratory device\\u000a(Ranque-Hilsch tube) that displays a similar enhanced angular momentum transfer\\u000awhich cannot be

  13. Achromatic orbital angular momentum generator

    NASA Astrophysics Data System (ADS)

    Bouchard, Frédéric; Mand, Harjaspreet; Mirhosseini, Mohammad; Karimi, Ebrahim; Boyd, Robert W.

    2014-12-01

    We describe a novel approach for generating light beams that carry orbital angular momentum (OAM) by means of total internal reflection in an isotropic medium. A continuous space-varying cylindrically symmetric reflector, in the form of two glued hollow axicons, is used to introduce a nonuniform rotation of polarization into a linearly polarized input beam. This device acts as a full spin-to-orbital angular momentum convertor. It functions by switching the helicity of the incoming beam's polarization, and by conservation of total angular momentum thereby generates a well-defined value of OAM. Our device is broadband, since the phase shift due to total internal reflection is nearly independent of wavelength. We verify the broad-band behaviour by measuring the conversion efficiency of the device for three different wavelengths corresponding to the RGB colours, red, green and blue. An average conversion efficiency of 95% for these three different wavelengths is observed. This device may find applications in imaging from micro- to astronomical systems where a white vortex beam is needed.

  14. Momentum anisotropy in nuclear collisions from quantum mechanics

    E-print Network

    Denes Molnar; Fuqiang Wang; Chris H. Greene

    2014-04-16

    We point out that the intrinsic relationship between space and momentum in quantum physics through the uncertainty principle has potential implications for momentum anisotropy in heavy-ion collisions. Using a harmonic oscillator potential we calculate the elliptic anisotropy and find it to be sizeable compared to elliptic flow measurements in nuclear collisions. Our results question the validity of the completely hydrodynamic interpretation of anisotropic flow data, and highlight the importance of including quantum physics in hydrodynamic calculations which has largely been neglected so far.

  15. Orbital angular momentum in phase space

    E-print Network

    I. Rigas; L. L. Sanchez-Soto; A. B. Klimov; J. Rehacek; Z. Hradil

    2010-11-29

    A comprehensive theory of the Weyl-Wigner formalism for the canonical pair angle-angular momentum is presented. Special attention is paid to the problems linked to rotational periodicity and angular-momentum discreteness.

  16. Energy and Momentum Transport in String Waves

    ERIC Educational Resources Information Center

    Juenker, D. W.

    1976-01-01

    Formulas are derived for the energy, momentum, and angular momentum transmitted by waves of arbitrary shape in an inextensible string by pure transverse waves in a string using Tait's procedure. (Author/CP)

  17. ANGULAR MOMENTUM AND GALAXY FORMATION REVISITED

    SciTech Connect

    Romanowsky, Aaron J. [University of California Observatories, 1156 High Street, Santa Cruz, CA 95064 (United States); Fall, S. Michael [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2012-12-15

    Motivated by a new wave of kinematical tracers in the outer regions of early-type galaxies (ellipticals and lenticulars), we re-examine the role of angular momentum in galaxies of all types. We present new methods for quantifying the specific angular momentum j, focusing mainly on the more challenging case of early-type galaxies, in order to derive firm empirical relations between stellar j{sub *} and mass M{sub *} (thus extending earlier work by Fall). We carry out detailed analyses of eight galaxies with kinematical data extending as far out as 10 effective radii, and find that data at two effective radii are generally sufficient to estimate total j{sub *} reliably. Our results contravene suggestions that ellipticals could harbor large reservoirs of hidden j{sub *} in their outer regions owing to angular momentum transport in major mergers. We then carry out a comprehensive analysis of extended kinematic data from the literature for a sample of {approx}100 nearby bright galaxies of all types, placing them on a diagram of j{sub *} versus M{sub *}. The ellipticals and spirals form two parallel j{sub *}-M{sub *} tracks, with log-slopes of {approx}0.6, which for the spirals are closely related to the Tully-Fisher relation, but for the ellipticals derives from a remarkable conspiracy between masses, sizes, and rotation velocities. The ellipticals contain less angular momentum on average than spirals of equal mass, with the quantitative disparity depending on the adopted K-band stellar mass-to-light ratios of the galaxies: it is a factor of {approx}3-4 if mass-to-light ratio variations are neglected for simplicity, and {approx}7 if they are included. We decompose the spirals into disks and bulges and find that these subcomponents follow j{sub *}-M{sub *} trends similar to the overall ones for spirals and ellipticals. The lenticulars have an intermediate trend, and we propose that the morphological types of galaxies reflect disk and bulge subcomponents that follow separate, fundamental j{sub *}-M{sub *} scaling relations. This provides a physical motivation for characterizing galaxies most basically with two parameters: mass and bulge-to-disk ratio. Next, in an approach complementary to numerical simulations, we construct idealized models of angular momentum content in a cosmological context, using estimates of dark matter halo spin and mass from theoretical and empirical studies. We find that the width of the halo spin distribution cannot account for the differences between spiral and elliptical j{sub *}, but that the observations are reproduced well if these galaxies simply retained different fractions of their initial j complement ({approx}60% and {approx}10%, respectively). We consider various physical mechanisms for the simultaneous evolution of j{sub *} and M{sub *} (including outflows, stripping, collapse bias, and merging), emphasizing that the vector sum of all such processes must produce the observed j{sub *}-M{sub *} relations. We suggest that a combination of early collapse and multiple mergers (major or minor) may account naturally for the trend for ellipticals. More generally, the observed variations in angular momentum represent simple but fundamental constraints for any model of galaxy formation.

  18. Angular Momentum and Galaxy Formation Revisited

    NASA Astrophysics Data System (ADS)

    Romanowsky, Aaron J.; Fall, S. Michael

    2012-12-01

    Motivated by a new wave of kinematical tracers in the outer regions of early-type galaxies (ellipticals and lenticulars), we re-examine the role of angular momentum in galaxies of all types. We present new methods for quantifying the specific angular momentum j, focusing mainly on the more challenging case of early-type galaxies, in order to derive firm empirical relations between stellar j sstarf and mass M sstarf (thus extending earlier work by Fall). We carry out detailed analyses of eight galaxies with kinematical data extending as far out as 10 effective radii, and find that data at two effective radii are generally sufficient to estimate total j sstarf reliably. Our results contravene suggestions that ellipticals could harbor large reservoirs of hidden j sstarf in their outer regions owing to angular momentum transport in major mergers. We then carry out a comprehensive analysis of extended kinematic data from the literature for a sample of ~100 nearby bright galaxies of all types, placing them on a diagram of j sstarf versus M sstarf. The ellipticals and spirals form two parallel j sstarf-M sstarf tracks, with log-slopes of ~0.6, which for the spirals are closely related to the Tully-Fisher relation, but for the ellipticals derives from a remarkable conspiracy between masses, sizes, and rotation velocities. The ellipticals contain less angular momentum on average than spirals of equal mass, with the quantitative disparity depending on the adopted K-band stellar mass-to-light ratios of the galaxies: it is a factor of ~3-4 if mass-to-light ratio variations are neglected for simplicity, and ~7 if they are included. We decompose the spirals into disks and bulges and find that these subcomponents follow j sstarf-M sstarf trends similar to the overall ones for spirals and ellipticals. The lenticulars have an intermediate trend, and we propose that the morphological types of galaxies reflect disk and bulge subcomponents that follow separate, fundamental j sstarf-M sstarf scaling relations. This provides a physical motivation for characterizing galaxies most basically with two parameters: mass and bulge-to-disk ratio. Next, in an approach complementary to numerical simulations, we construct idealized models of angular momentum content in a cosmological context, using estimates of dark matter halo spin and mass from theoretical and empirical studies. We find that the width of the halo spin distribution cannot account for the differences between spiral and elliptical j sstarf, but that the observations are reproduced well if these galaxies simply retained different fractions of their initial j complement (~60% and ~10%, respectively). We consider various physical mechanisms for the simultaneous evolution of j sstarf and M sstarf (including outflows, stripping, collapse bias, and merging), emphasizing that the vector sum of all such processes must produce the observed j sstarf-M sstarf relations. We suggest that a combination of early collapse and multiple mergers (major or minor) may account naturally for the trend for ellipticals. More generally, the observed variations in angular momentum represent simple but fundamental constraints for any model of galaxy formation.

  19. The Growing Momentum and Legitimacy behind an Alliance for International Education

    ERIC Educational Resources Information Center

    Bunnell, Tristan

    2006-01-01

    Within the diverse universe of internationally minded schools there is currently much momentum behind the creation of some form of "alliance". Although the movement behind this can be traced back to the early 1990s, this article proposes that the current momentum can be largely understood within a fundamental paradigm shift emerging within…

  20. Comment on ``Geometric absorption of electromagnetic angular momentum'', C. Konz, G. Benford

    NASA Astrophysics Data System (ADS)

    Nieminen, Timo A.

    2004-05-01

    The core theorem on which the above paper is centred - that a perfectly conducting body of revolution absorbs no angular momentum from an axisymmetric electromagnetic wave field - is in fact a special case of a more general result in electromagnetic scattering theory. In addition, the scaling of the efficiency of transfer of angular momentum to an object with the wavelength and object size merits further discussion. Finally, some comments are made on the choice of terminology and the erroneous statement that a circularly polarized plane wave does not carry angular momentum.

  1. The runaway instability of thick discs around black holes. II. Non constant angular momentum discs

    E-print Network

    Frederic Daigne; Jose A. Font

    2003-11-28

    We present results from a comprehensive number of relativistic, time-dependent, axisymmetric simulations of the runaway instability of non-constant angular momentum thick discs around black holes. This second paper extends earlier results where only constant angular momentum discs were considered. All relevant aspects of the theory of stationary thick discs around rotating black holes, necessary to build the initial state in our simulations, are presented in great detail. The angular momentum of the discs is assumed to increase outwards with the radial distance according to a power law. The main simplifying assumptions of our approach are not to include magnetic fields and self-gravity in the discs. Furthermore, the dynamics of the spacetime is accounted for by computing the transfer of mass and angular momentum from the disc to the black hole through the event horizon : the evolution of the central black hole is assumed to follow a sequence of Kerr black holes of increasing mass and spin. In agreement with previous results based on stationary models we find that by allowing the mass and the spin of the black hole to grow, constant angular momentum discs rapidly become unstable on a dynamical timescale. The comparison with the results of paper I shows that the effect of the angular momentum transfer from the torus to the black hole is to make constant angular momentum discs less unstable, increasing the timescale of the instability. However, we find that non-constant angular momentum discs are dramatically stabilized for very small values of the angular momentum slope. Our time-dependent simulations confirm, thus, the predictions of stationary studies concerning the stabilizing effect of non-constant angular momentum distributions.

  2. The angular momentum of the Oort cloud

    Microsoft Academic Search

    P Weissman

    1991-01-01

    An evaluation is made of the work of Marochnik et al. (1988), which estimated that the angular momentum of the Oort cloud is 2-3 orders of magnitude greater than the planetary system's total angular momentum. It is noted that most of the angular momentum in the currently observed Oort cloud is the result of the effects of external perturbers over

  3. Physics 321 Linear Momentum and Its Conservation

    E-print Network

    Hart, Gus

    Physics 321 Hour 5 Linear Momentum and Its Conservation Four kinds of "collisions" · Elastic: T conserved · Inelastic: some energy loss · Totally inelastic: objects stick ­ maximum energy loss ­ energy inelastic collision timereversed Momentum Conservation In what collisions can you apply momentum

  4. Angular Momentum Decomposition for an Electron

    SciTech Connect

    Burkardt, Matthias; BC, Hikmat

    2009-01-01

    We calculate the orbital angular momentum of the `quark' in the scalar diquark model as well as that of the electron in QED (to order $\\alpha$). We compare the orbital angular momentum obtained from the Jaffe-Manohar decomposition to that obtained from the Ji relation and estimate the importance of the vector potential in the definition of orbital angular momentum.

  5. Angular momentum decomposition for an electron

    SciTech Connect

    Burkardt, Matthias; Hikmat, BC [Department of Physics, New Mexico State University, Las Cruces, New Mexico 88003-0001 (United States)

    2009-04-01

    We calculate the orbital angular momentum of the 'quark' in the scalar diquark model as well as that of the electron in QED (to order {alpha}). We compare the orbital angular momentum obtained from the Jaffe-Manohar decomposition to that obtained from the Ji relation and estimate the importance of the vector potential in the definition of orbital angular momentum.

  6. Photoionization with Orbital Angular Momentum Beams

    Microsoft Academic Search

    A. Picón; J. Mompart; J. R. Vázquez de Aldana; L. Plaja; G. F. Calvo; L. Roso

    2010-01-01

    Intense laser ionization expands Einstein's photoelectric effect rules giving a wealth of phenomena widely studied over the last decades. In all cases, so far, photons were assumed to carry one unit of angular momentum. However it is now clear that photons can possess extra angular momentum, the orbital angular momentum (OAM), related to their spatial profile. We show a complete

  7. Photon Orbital Angular Momentum in Astrophysics

    Microsoft Academic Search

    Martin Harwit

    2003-01-01

    Observations of the orbital angular momentum of photons --- a property of electromagnetic radiation that has come to the fore in recent years --- have apparently never been attempted in astronomy. By now it is known from laboratory studies that, in addition to carrying spin angular momentum, individual photons can carry N >> 100 units of orbital angular momentum h\\/2pi

  8. Wigner Functions and Quark Orbital Angular Momentum

    E-print Network

    Asmita Mukherjee; Sreeraj Nair; Vikash Kumar Ojha

    2014-09-25

    Wigner distributions contain combined position and momentum space information of the quark distributions and are related to both generalized parton distributions (GPDs) and transverse momentum dependent parton distributions (TMDs). We report on a recent model calculation of the Wigner distributions for the quark and their relation to the orbital angular momentum.

  9. Robust controllers for space station momentum management

    Microsoft Academic Search

    Michael R. Elgersma; Gunter Stein; Michael R. Jackson; John Yeichner

    1992-01-01

    The design of controllers for space station attitude control and momentum management is described. Fundamental control performance tradeoffs between stabilization, attitude regulation, and momentum magnitudes are explored using H-infinity optimization. The resulting controllers stabilize the unstable gravity gradient torques, keep attitudes and momentums due to aero disturbance torques small, and are robust to uncertainties in the moments of inertia of

  10. Attitude stabilization of bias momentum satellites

    Microsoft Academic Search

    Marcel Sidi

    1992-01-01

    In earth pointing satellites the use of momentum bias is a common practice for stabilizing against external disturbances. This approach is of great utility, especially in systems in which the measurement of the yaw angle is not available. The momentum bias provides a natural gyroscopic stability, however, harmonic external disturbances or energy dissipation in the rotor of the momentum wheel

  11. FLEXIBLE SPACECRAFT REORIENTATIONS USING GIMBALED MOMENTUM WHEELS

    E-print Network

    Hall, Christopher D.

    FLEXIBLE SPACECRAFT REORIENTATIONS USING GIMBALED MOMENTUM WHEELS Kevin A. Fordy and Christopher D concise form of the equations of motion for a spacecraft with gimbaled momentum wheels and exible) or control moment gyros ( xed spin speed). The gimbaled momentum wheel (GMW) is simply a combination

  12. Dispersion from safety valves and other momentum emission sources: Continuous

    NASA Astrophysics Data System (ADS)

    Hanzevack, E. L.

    Safety valves are atypical pollutant emission sources in petroleum refineries and chemical plants. Their releases are characterized by very high velocities (from 20ms -1 to sonic) and near-ambient temperatures, so they are referred to as momentum sources, as opposed to bouyant sources. Since releases from these sources to the atmosphere may contain relatively high (often 100%) pollutant concentrations we have developed a method of accurately predicting the critical ground level concentrations of pollutants resulting from such sources. (The critical ground level concentration is the highest ambient pollutant concentration at any downwind location or meterological condition.) Since no data were available on which to base an air dispersion model for predicting ground level concentrations for momentum sources, an experimental program was undertaken, consisting of a full scale simulation of a momentum source emission using an inert tracer gas and downwind sampling to determine resulting critical ground level concentrations. Based on the data collected, a dispersion calculation method for estimating ground level concentrations from momentum sources was developed. The general form of this correlation is similar to the previously suggested, but not validated, American Society of Mechanical Engineers (ASME) momentum plume equation. The modified equation contains an additional parameter to account for the large gas density differences often encountered with momentum source releases. The equation was designed to be somewhat conservative to compensate for the randomness of atmospheric phenomena, the limited amount of experimental data, and the fact that safety valve releases can include dangerous substances. The calculation method described in this report is recommended to predict peak ambient concentrations for any source dominated by momentum plume conditions.

  13. Spin and Orbital Angular Momentum Distribution Functions of the Nucleon

    E-print Network

    M. Wakamatsu; T. Watabe

    2000-04-20

    A theoretical prediction is given for the spin and orbital angular momentum distribution functions of the nucleon within the framework of an effective quark model of QCD, i.e. the chiral quark soliton model. An outstanding feature of the model is that it predicts fairly small quark spin fraction of the nucleon $\\Delta \\Sigma \\simeq 0.35$, which in turn dictates that the remaining 65% of the nucleon spin is carried by the orbital angular momentum of quarks and antiquarks at the model energy scale of $Q^2 \\simeq 0.3 {GeV}^2$. This large orbital angular momentum necessarily affects the scenario of scale dependence of the nucleon spin contents in a drastic way.

  14. Optical vortices with large orbital momentum: generation and interference

    E-print Network

    91109-8099 2 Moscow Lomonosov State University, Department of Physics, Vorob'evy Gory, Moscow, 119992," Progress in Physics 52, 1141- 1153 (2004). 4. D. McGloin and K. Dholakia, "Bessel beams: diffraction," Phys. Rev. Lett. 90, 203901 (2003). 10. F. Gori, G. Guattari, and C. Padovani, "Bessel-Gauss beams

  15. A Survey of Nursing Home Organizational Characteristics Associated with Potentially Avoidable Hospital Transfers and Care Quality in One Large British Columbia Health Region

    ERIC Educational Resources Information Center

    McGregor, Margaret J.; Baumbusch, Jennifer; Abu-Laban, Riyad B.; McGrail, Kimberlyn M.; Andrusiek, Dug; Globerman, Judith; Berg, Shannon; Cox, Michelle B.; Salomons, Kia; Volker, Jan; Ronald, Lisa

    2011-01-01

    Hospitalization of nursing home residents can be futile as well as costly, and now evidence indicates that treating nursing home residents in place produces better outcomes for some conditions. We examined facility organizational characteristics that previous research showed are associated with potentially avoidable hospital transfers and with…

  16. Superatoms (Li3O and BeF3) induce phenalenyl radical ?-dimer: fascinating interlayer charge-transfer and large NLO responses.

    PubMed

    Chen, Sa; Sun, Shi-Ling; Wu, Heng-Qing; Xu, Hong-Liang; Zhao, Liang; Su, Zhong-Min

    2014-09-01

    Recently, the well-known phenalenyl radical ?-dimer with its fascinating 2-electron/12-center (2e/12c) bond has attracted our attention. In this work, we designed two molecules, Li3OC13H9 () and BeF3C13H9 (). Interestingly, owing to the inductive effect of superatoms, an electron is transferred from Li3O to phenalenyl in , while an electron is transferred from phenalenyl to BeF3 in . Further, we employed and as building blocks to assemble two novel molecules with 2e/12c bonds: Li3O(C13H9)2BeF3 () and Li3O(C13H9)2BeF3 (). Remarkably, and with novel 2e/12c bonds exhibit a dramatic interlayer charge-transfer character, which results in a significant difference of dipole moments (??: 2.6804 for and 3.8019 Debye for ) between the ground state and the crucial excited state. As a result, the static first hyperpolarizabilities (?0: 5154 for and 12?500 au for ) are considerably larger than the values of 347 for and 328 au for . It is our expectation that the results of the present work might provide beneficial information for further theoretical and experimental studies on the fascinating properties of molecules with interlayer charge-transfer character. PMID:25010818

  17. Heat transfer in pipes

    NASA Technical Reports Server (NTRS)

    Burbach, T.

    1985-01-01

    The heat transfer from hot water to a cold copper pipe in laminar and turbulent flow condition is determined. The mean flow through velocity in the pipe, relative test length and initial temperature in the vessel were varied extensively during tests. Measurements confirm Nusselt's theory for large test lengths in laminar range. A new equation is derived for heat transfer for large starting lengths which agrees satisfactorily with measurements for large starting lengths. Test results are compared with the new Prandtl equation for heat transfer and correlated well. Test material for 200- and to 400-diameter test length is represented at four different vessel temperatures.

  18. Angular momentum desaturation for Skylab using gravity gradient torques

    NASA Technical Reports Server (NTRS)

    Kennel, H. F.

    1971-01-01

    An angular momentum desaturation method for momentum exchange devices of orbiting spacecraft is described. The specific application of the method is to the Skylab which contains three double-gimbaled control moment gyros for precise attitude control and maneuvering. It is assumed that the attitude reference is inertially fixed and that two of the vehicle principal moments of inertia are much larger than the third. Gravity gradient torques and resultant angular momentum accumulation are developed for small deviations from the reference. The assumed moment-of-inertia distribution allows desaturation about all axes with only two attitude angles each for the two axes with large moments of inertia. The necessary desaturation maneuvers can be decoupled for a special set of orbital coordinates. All maneuvers are made during the night portion of the orbit, and the percentage utilized for desaturation is selectable. Expressions for the attitude angle commands are developed assuming infinite vehicle rates. The effect of finite rates introduces an efficiency into the desaturation. Expressions for this efficiency are developed and means for compensation are treated. Arbitrary misalignments between geometric vehicle axes and principal moment-of-inertia axes are permissible. An angle bias about the sun line minimizes the angular momentum accumulation about the sun line projection into the orbital plane. Adaptive desaturation maneuver limiting consistent with the available maneuver momentum is included.

  19. Pretzelosity TMD and Quark Orbital Angular Momentum

    E-print Network

    C. Lorce'; B. Pasquini

    2012-03-22

    We study the connection between the quark orbital angular momentum and the pretzelosity transverse-momentum dependent parton distribution function. We discuss the origin of this relation in quark models, identifying as key ingredient for its validity the assumption of spherical symmetry for the nucleon in its rest frame. Finally we show that the individual quark contributions to the orbital angular momentum obtained from this relation can not be interpreted as the intrinsic contributions, but include the contribution from the transverse centre of momentum which cancels out only in the total orbital angular momentum.

  20. Coherent Stern-Gerlach momentum splitting on an atom chip.

    PubMed

    Machluf, Shimon; Japha, Yonathan; Folman, Ron

    2013-01-01

    In the Stern-Gerlach effect, a magnetic field gradient splits particles into spatially separated paths according to their spin projection. The idea of exploiting this effect for creating coherent momentum superpositions for matter-wave interferometry appeared shortly after its discovery, almost a century ago, but was judged to be far beyond practical reach. Here we demonstrate a viable version of this idea. Our scheme uses pulsed magnetic field gradients, generated by currents in an atom chip wire, and radio-frequency Rabi transitions between Zeeman sublevels. We transform an atomic Bose-Einstein condensate into a superposition of spatially separated propagating wavepackets and observe spatial interference fringes with a measurable phase repeatability. The method is versatile in its range of momentum transfer and the different available splitting geometries. These features make our method a good candidate for supporting a variety of future applications and fundamental studies. PMID:24013518