Sample records for large momentum transfers

  1. The Pion Form Factor at Large Momentum Transfer

    E-print Network

    Pai-hsien Jennifer Hsu; George T. Fleming

    2007-10-24

    We present our calculations of the electromagnetic form factor of pions. We explore the properties of pion form factor at momentum transfer larger than previous studies by including more combinations of source and sink momenta and using more configurations.We fit our results using vector meson dominance (VMD) hypothesis.

  2. Photoproduction of straight phi(1020) mesons on the proton at large momentum transfer

    PubMed

    Murphy; Mutchler; Napolitano; Niyazov; Opper; O'Brien; Philips; Pivnyuk; Pocanic; Pogorelko; Polli; Preedom; Price; Qin; Raue; Reolon; Riccardi; Ricco; Ripani; Ritchie; Ronchetti; Rossi; Roudot; Rowntree; Rubin; Salgado

    2000-11-27

    The cross section for straight phi meson photoproduction on the proton has been measured for the first time up to a four-momentum transfer -t = 4 GeV2, using the CLAS detector at the Thomas Jefferson National Accelerator Facility. At low four-momentum transfer, the differential cross section is well described by Pomeron exchange. At large four-momentum transfer, above -t = 1.8 GeV2, the data support a model where the Pomeron is resolved into its simplest component, two gluons, which may couple to any quark in the proton and in the straight phi. PMID:11082626

  3. 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.

  4. Measurement of diffractive scattering of photons with large momentum transfer at HERA

    NASA Astrophysics Data System (ADS)

    Aaron, F. D.; Alexa, C.; Andreev, V.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Bacchetta, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Beckingham, M.; Begzsuren, K.; Behnke, O.; Belousov, A.; Berger, N.; Bizot, J. C.; Boenig, M.-O.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Bruncko, D.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A. J.; Cantun Avila, K. B.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Cholewa, A.; Contreras, J. G.; Coughlan, J. A.; Cozzika, G.; Cvach, J.; Dainton, J. B.; Daum, K.; Deák, M.; de Boer, Y.; Delcourt, B.; Del Degan, M.; Delvax, J.; De Roeck, A.; De Wolf, E. A.; Diaconu, C.; Dodonov, V.; Dossanov, A.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkiewicz, A.; Faulkner, P. J. W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Fomenko, A.; Gabathuler, E.; Gayler, J.; Ghazaryan, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gouzevitch, M.; Grab, C.; Greenshaw, T.; Grell, B. R.; Grindhammer, G.; Habib, S.; Haidt, D.; Hansson, M.; Helebrant, C.; Henderson, R. C. W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K. H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Jacquet, M.; Janssen, M. E.; Janssen, X.; Jemanov, V.; Jönsson, L.; Johnson, D. P.; Jung, A. W.; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I. R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knutsson, A.; Kogler, R.; Korbel, V.; Kostka, P.; Kraemer, M.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Krüger, K.; Kutak, K.; Landon, M. P. J.; Lange, W.; Laštovi?ka-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Li, G.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lytkin, L.; Makankine, A.; Malinovski, E.; Marage, P.; Marti, Ll.; Martyn, H.-U.; Maxfield, S. J.; Mehta, A.; Meier, K.; Meyer, A. B.; Meyer, H.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Moreau, F.; Morozov, A.; Morris, J. V.; Mozer, M. U.; Mudrinic, M.; Müller, K.; Murín, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, P. R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Olivier, B.; Olsson, J. E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, Th.; Pascaud, C.; Patel, G. D.; Pejchal, O.; Peng, H.; Perez, E.; Petrukhin, A.; Picuric, I.; Piec, S.; Pitzl, D.; Pla?akyt?, R.; Polifka, R.; Povh, B.; Preda, T.; Radescu, V.; Rahmat, A. J.; Raicevic, N.; Raspiareza, A.; Ravdandorj, T.; Reimer, P.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rotaru, M.; Ruiz Tabasco, J. E.; Rurikova, Z.; Rusakov, S.; Salek, D.; Salvaire, F.; Sankey, D. P. C.; Sauter, M.; Sauvan, E.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schöning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R. N.; Sheviakov, I.; Shtarkov, L. N.; Shushkevich, S.; Sloan, T.; Smiljanic, I.; Smirnov, P.; Soloviev, Y.; Sopicki, P.; South, D.; Spaskov, V.; Specka, A.; Staykova, Z.; Steder, M.; Stella, B.; Straumann, U.; Sunar, D.; Sykora, T.; Tchoulakov, V.; Thompson, G.; Thompson, P. D.; Toll, T.; Tomasz, F.; Tran, T. H.; Traynor, D.; Trinh, T. N.; Truöl, P.; Tsakov, I.; Tseepeldorj, B.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Valkárová, A.; Vallée, C.; Van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Vinokurova, S.; Volchinski, V.; Wegener, D.; Wessels, M.; Wissing, Ch.; Wünsch, E.; Yeganov, V.; Žá?ek, J.; Zálešák, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y. C.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.; H1 Collaboration

    2009-02-01

    The first measurement of diffractive scattering of quasi-real photons with large momentum transfer ?p ? ?Y, where Y is the proton dissociative system, is made using the H1 detector at HERA. The measurement is performed for initial photon virtualities Q2 < 0.01GeV2. Single differential cross sections are measured as a function of W, the incident photon-proton centre of mass energy, and t, the square of the four-momentum transferred at the proton vertex, in the range 175 < W < 247 GeV and 4 < | t | < 36GeV2. The W dependence is well described by a model based on perturbative QCD using a leading logarithmic approximation of the BFKL evolution. The measured | t | dependence is harder than that predicted by the model and those observed in exclusive vector meson production.

  5. Measurement of diffractive scattering of photons with large momentum transfer at HERA

    NASA Astrophysics Data System (ADS)

    H1 Collaboration; Aaron, F. D.; Alexa, C.; Andreev, V.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Bacchetta, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Beckingham, M.; Begzsuren, K.; Behnke, O.; Belousov, A.; Berger, N.; Bizot, J. C.; Boenig, M.-O.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Bruncko, D.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A. J.; Cantun Avila, K. B.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Cholewa, A.; Contreras, J. G.; Coughlan, J. A.; Cozzika, G.; Cvach, J.; Dainton, J. B.; Daum, K.; Deák, M.; de Boer, Y.; Delcourt, B.; Del Degan, M.; Delvax, J.; de Roeck, A.; de Wolf, E. A.; Diaconu, C.; Dodonov, V.; Dossanov, A.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkiewicz, A.; Faulkner, P. J. W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Fomenko, A.; Gabathuler, E.; Gayler, J.; Ghazaryan, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gouzevitch, M.; Grab, C.; Greenshaw, T.; Grell, B. R.; Grindhammer, G.; Habib, S.; Haidt, D.; Hansson, M.; Helebrant, C.; Henderson, R. C. W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K. H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Jacquet, M.; Janssen, M. E.; Janssen, X.; Jemanov, V.; Jönsson, L.; Johnson, D. P.; Jung, A. W.; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I. R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knutsson, A.; Kogler, R.; Korbel, V.; Kostka, P.; Kraemer, M.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Krüger, K.; Kutak, K.; Landon, M. P. J.; Lange, W.; Laštovi?ka-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Li, G.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lytkin, L.; Makankine, A.; Malinovski, E.; Marage, P.; Marti, Ll.; Martyn, H.-U.; Maxfield, S. J.; Mehta, A.; Meier, K.; Meyer, A. B.; Meyer, H.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Moreau, F.; Morozov, A.; Morris, J. V.; Mozer, M. U.; Mudrinic, M.; Müller, K.; Murín, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, P. R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Olivier, B.; Olsson, J. E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, Th.; Pascaud, C.; Patel, G. D.; Pejchal, O.; Peng, H.; Perez, E.; Petrukhin, A.; Picuric, I.; Piec, S.; Pitzl, D.; Pla?akyt?, R.; Polifka, R.; Povh, B.; Preda, T.; Radescu, V.; Rahmat, A. J.; Raicevic, N.; Raspiareza, A.; Ravdandorj, T.; Reimer, P.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rotaru, M.; Ruiz Tabasco, J. E.; Rurikova, Z.; Rusakov, S.; Salek, D.; Salvaire, F.; Sankey, D. P. C.; Sauter, M.; Sauvan, E.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schöning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R. N.; Sheviakov, I.; Shtarkov, L. N.; Shushkevich, S.; Sloan, T.; Smiljanic, I.; Smirnov, P.; Soloviev, Y.; Sopicki, P.; South, D.; Spaskov, V.; Specka, A.; Staykova, Z.; Steder, M.; Stella, B.; Straumann, U.; Sunar, D.; Sykora, T.; Tchoulakov, V.; Thompson, G.; Thompson, P. D.; Toll, T.; Tomasz, F.; Tran, T. H.; Traynor, D.; Trinh, T. N.; Truöl, P.; Tsakov, I.; Tseepeldorj, B.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Valkárová, A.; Vallée, C.; van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Vinokurova, S.; Volchinski, V.; Wegener, D.; Wessels, M.; Wissing, Ch.; Wünsch, E.; Yeganov, V.; Žá?ek, J.; Zálešák, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y. C.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.

    2009-02-01

    The first measurement of diffractive scattering of quasi-real photons with large momentum transfer ?p??Y, where Y is the proton dissociative system, is made using the H1 detector at HERA. The measurement is performed for initial photon virtualities Q<0.01 GeV. Single differential cross sections are measured as a function of W, the incident photon-proton centre of mass energy, and t, the square of the four-momentum transferred at the proton vertex, in the range 175

  6. Measurement of the Deuteron Elastic Structure Function A(Q^2) at Large Momentum Transfers

    NASA Astrophysics Data System (ADS)

    McCormick, Kathy

    1998-10-01

    The deuteron elastic structure function A(Q^2) was measured at large momentum transfers using the Hall-A Facility of the Jefferson Laboratory (JLAB). Scattered electrons and recoiling deuterons were detected in coincidence in the two 4 GeV/c High Resolution Spectrometers (HRS) of Hall-A. The range in squared four-momentum transfer, Q^2, was 2.4 to 6.0 (GeV/c)^2. This experiment was able to measure record low cross sections. This was possible by using the recently commissioned high power (700W), high luminosity (5× 10^38 nuclei/cm^2/s) cryogenic deuterium target of Hall-A. The results will be compared to predictions of the dimensional scaling quark model and to perturbative quantum chromodynamics. The results are expected to provide a crucial test of nuclear chromodynamics ideas and to provide insights into the transition from meson-nucleon to quark-gluon descriptions of the nuclear two-body system.

  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. DGLAP versus perturbative Pomeron in large momentum transfer hard diffractive processes at HERA and LHC

    NASA Astrophysics Data System (ADS)

    Blok, B.; Frankfurt, L.; Strikman, M.

    2010-06-01

    We evaluate within the LO DGLAP approximation the dependence on energy of the cross section of the photo(electro)production of vector meson V (V=J/?,…) in the hard elastic processes off a parton ?+g?V+g as the function of momentum transfer t=(. We demonstrate that in the limit -t?mV2+Q the cross section does not contain double logarithmic terms in any order of the DGLAP approximation leading to the energy independent cross section. Thus the energy dependence of cross section ?+p?J/?+rapidity gap+X is governed at large t by the gluon distribution within a proton, i.e. it is unambiguously predicted within the DGLAP approximation including the stronger W?N dependence at larger -t. This prediction explains recent HERA data. The calculations which follow perturbative Pomeron logic predict opposite trend of a weaker W?N dependence at larger t. We explain that at the HERA energies double logarithmic terms characteristic for DGLAP approximation dominate in the hard processes as the consequence of the constraints due to the energy-momentum conservation. We give predictions for the ultraperipheral hard diffractive processes at the LHC and show that these processes are well suited for looking for the contribution of the single logarithmic terms due to the gluon emission in the multi-Regge kinematics. We also comment on the interrelation between energy and t dependence of the cross sections of the hard exclusive processes.

  10. 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.

  11. Measurement of the electric and magnetic elastic structure functions of the deuteron at large momentum transfers

    NASA Astrophysics Data System (ADS)

    Suleiman, Riad Suleiman

    The deuteron elastic structure functions, A( Q2) and B(Q 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(Q2) was extracted from forward angle cross section measurements in the squared four-momentum transfer range 0.684 <= Q2 <= 5.90 (GeV/C) 2. B(Q2) was determined by means of a Rosenbluth separation in the range 0.684 <= Q 2 <= 1.325 (GeV/c)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.

  12. 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.

  13. Transfer Coefficients of Momentum, Heat and Water Vapour in the Atmospheric Surface Layer of a Large Freshwater Lake

    NASA Astrophysics Data System (ADS)

    Xiao, Wei; Liu, Shoudong; Wang, Wei; Yang, Dong; Xu, Jiaping; Cao, Chang; Li, Hanchao; Lee, Xuhui

    2013-09-01

    In studies of lake-atmosphere interactions, the fluxes of momentum, water vapour and sensible heat are often parametrized as being proportional to the differences in wind, humidity and air temperature between the water surface and a reference height above the surface. Here, the proportionality via transfer coefficients in these relationships was investigated with the eddy-covariance method at three sites within an eddy-covariance mesonet across Lake Taihu, China. The results indicate that the transfer coefficients decreased with increasing wind speed for weak winds and approached constant values for strong winds. The presence of submerged macrophytes reduced the momentum transfer (drag) coefficient significantly. At the two sites free of submerged macrophytes, the 10-m drag coefficients under neutral stability were 1.8 and at the wind speed of , which are 38 and 34 % greater than the prediction by the Garratt model for the marine environment.

  14. Electromagnetic structure of the proton, pion, and kaon by high-precision form factor measurements at large timelike momentum transfers.

    PubMed

    Seth, Kamal K; Dobbs, S; Metreveli, Z; Tomaradze, A; Xiao, T; Bonvicini, G

    2013-01-11

    The electromagnetic structure of the lightest hadrons, proton, pion, and kaon is studied by high-precision measurements of their form factors for the highest timelike momentum transfers of |Q2|=s=14.2 and 17.4??GeV2. Data taken with the CLEO-c detector at sqrt[s]=3.772 and 4.170 GeV, with integrated luminosities of 805 and 586??pb(-1), respectively, have been used to study e+ e- annihilations into ?+ ?-, K+ K-, and pp. The dimensional counting rule prediction that at large Q2 the quantity Q2F(Q2) for pseudoscalar mesons is nearly constant, and should vary only weakly as the strong coupling constant ?S(Q2) is confirmed for both pions and kaons. However, the measurements are in strong quantitative disagreement with the predictions of the existing quantum chromodynamics-based models. For protons, it is found that the timelike form factors continue to remain nearly twice as large as the corresponding spacelike form factors measured in electron elastic scattering, in significant violation of the expectation of their equality at large Q2. Further, in contrast to pions and kaons, a significant difference is observed between the values of the corresponding quantity |Q4|G(M)(|Q2|)/?(p) for protons at |Q2|=14.2 and 17.4??GeV2. The results suggest the constancy of |Q2|G(M)(|Q2|)/?(p), instead, at these large |Q2|. PMID:23383892

  15. Measurement of deviations from Bjorken scaling for large momentum transfer scatters of 56 and 150 GeV muons from an iron target

    SciTech Connect

    Herb, S.W.

    1983-01-01

    An experiment measuring large momentum transfer inelastic scatters of muons from an iron target is described. The data are analyzed for deviations from the Bjorken scaling prediction that the nucleon structure function nuW/sub 2/(omega) be independent of the four-momentum transfer Q/sup 2/. Significant deviations are observed: as absolute value Q/sup 2/ increases, nuW/sub 2/ increases for omega > 6 and decreases for omega < 6. These deviations are parameterized and compared with qualitative expectations from scale-breaking in asymptotically free field theories and from the turn-on of a charm contribution to the scatters.

  16. Optical model analysis of 200 MeV p-->+16O elastic scattering data measured to large momentum transfers

    NASA Astrophysics Data System (ADS)

    Glover, C. W.; Schwandt, P.; Meyer, H. O.; Jacobs, W. W.; Hall, J. R.; Kaitchuck, M. D.; Devito, R. P.

    1985-01-01

    Differential cross sections and analyzing powers are presented for 16O(p-->,p)16O elastic scattering at Ep=200 MeV, extending over a large range of momentum transfer (up to q~6 fm-1). The data were analyzed in the framework of the nonrelativistic optical model. In addition to standard Woods-Saxon potentials, nonstandard radial shapes for the central and the spin-orbit potentials were investigated. The data are not adequately described over the entire angular range using a Woods-Saxon real central potential, but two distinct parametrizations (not simply related by the usual discrete or continuous parameter ambiguities which maintain a rough phase-shift equivalence) were found which provide a far superior representation. The similarity in the angular distributions given by these two potentials can be attributed to the fact that the non-spin-flip partial-wave scattering amplitudes aL differ by only a simple rotation in the complex aL plane. This rotation has a negligible effect on the predicted cross section and the analyzing power angular distributions, but leads to sizable differences in the predicted spin-rotation function Q(?).

  17. Momentum transfer for momentum transfer-free which-path experiments

    E-print Network

    Aurelien Drezet; Andreas Hohenau; Joachim R. Krenn

    2006-05-24

    We analyze the origin of interference disappearance in which-path double aperture experiments. We show that we can unambiguously define an observable momentum transfer between the quantum particle and the path detector and we prove in particular that the so called ``momentum transfer free'' experiments can be in fact logically interpreted in term of momentum transfer.

  18. First measurement of the electromagnetic form factor of the neutral kaon at a large momentum transfer and the effect of SU(3) breaking

    NASA Astrophysics Data System (ADS)

    Seth, Kamal K.; Dobbs, S.; Tomaradze, A.; Xiao, T.; Bonvicini, G.

    2014-03-01

    At large momentum transfers the photon interacts with the charges and spins of the constituent partons in a hadron. It is expected that the neutral kaon can acquire finite electromagnetic form factors because its wave function is affected by the order of magnitude difference between the mass of the strange quark and that of the down quark, or flavor SU(3) breaking. We report on the first measurement of the form factor of neutral kaons at the large timelike momentum transfer of |Q2|=17.4 GeV by measuring the cross section for e+e-?KSKL at ?{s}=4.17 GeV using CLEO-c data with an integrated luminosity of 586 pb-1. We obtain F(17.4 GeV)=5.3×10-3, with a 90% C.L. interval of (2.9-8.2)×10-3. This is nearly an order of magnitude smaller than F(17.4 GeV)=(44±1)×10-3, and indicates that the effect of SU(3) breaking is small. In turn, this makes it unlikely that the recently observed strong violation of the pQCD prediction, F(|Q2|)/F(|Q2|)=f?2/fK2, which is based on the assumption of similar wave functions for the pions and kaons, can be attributed to SU(3) breaking alone.

  19. Optical model analysis of 200 MeV p+/sup 16/O elastic scattering data measured to large momentum transfers

    SciTech Connect

    Glover, C.W.; Schwandt, P.; Meyer, H.O.; Jacobs, W.W.; Hall, J.R.; Kaitchuck, M.D.; DeVito, R.P.

    1985-01-01

    Differential cross sections and analyzing powers are presented for /sup 16/O(p,p)/sup 16/O elastic scattering at E/sub p/ = 200 MeV, extending over a large range of momentum transfer (up to qapprox.6 fm/sup -1/). The data were analyzed in the framework of the nonrelativistic optical model. In addition to standard Woods-Saxon potentials, nonstandard radial shapes for the central and the spin-orbit potentials were investigated. The data are not adequately described over the entire angular range using a Woods-Saxon real central potential, but two distinct parametrizations (not simply related by the usual discrete or continuous parameter ambiguities which maintain a rough phase-shift equivalence) were found which provide a far superior representation. The similarity in the angular distributions given by these two potentials can be attributed to the fact that the non-spin-flip partial-wave scattering amplitudes a/sub L/ differ by only a simple rotation in the complex a/sub L/ plane. This rotation has a negligible effect on the predicted cross section and the analyzing power angular distributions, but leads to sizable differences in the predicted spin-rotation function Q(theta).

  20. Electroproduction at large momentum transfers

    SciTech Connect

    van Bibber, K.

    1991-03-01

    The possibilities of electroproduction experiments at a facility such as the proposed European electron accelerator are discussed. Examples given are from studies of hadronization, color transparency, backward production, virtual Compton scattering and target spectator decay. Some conclusions about machine parameters are drawn. 25 refs., 15 figs.

  1. 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

  2. A Measurement of the neutron electric form factor at very large momentum transfer using polaried electrions scattering from a polarized helium-3 target

    SciTech Connect

    Aidan Kelleher

    2010-10-01

    Knowledge of the electric and magnetic elastic form factors of the nucleon is essential for an understanding of nucleon structure. Of the form factors, the electric form factor of the neutron has been measured over the smallest range in Q{sup 2} and with the lowest precision. Jefferson Lab experiment 02-013 used a novel new polarized {sup 3}He target to nearly double the range of momentum transfer in which the neutron form factor has been studied and to measure it with much higher precision. Polarized electrons were scattered off this target, and both the scattered electron and neutron were detected. G{sup n}{sub E} was measured to be 0.0242 ± 0.0020(stat) ± 0.0061(sys) and 0.0247 ± 0.0029(stat) ± 0.0031(sys) at Q{sup 2} = 1.7 and 2.5 GeV{sup 2}, respectively.

  3. 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.

  4. Oblique impact: Projectile richochet, concomitant ejecta and momentum transfer

    NASA Technical Reports Server (NTRS)

    Gault, Donald E.; Schultz, Peter H.

    1987-01-01

    Experimental studies of oblique impact indicate that projectile richochet occurs for trajectory angles less than 30 deg and that the richocheted projectile, accompanied by some target material, are ejected at velocities that are a large fraction of the impact velocity. Because the probability of occurrence of oblique impact less than 30 deg on a planetary body is about one out of every four impact events, oblique impacts would seem to be a potential mechanism to provide a source of meteorites from even the largest atmosphere-free planetary bodies. Because the amount of richocheted target material cannot be determined from previous results, additional experiments in the Ames Vertical Gun laboratory were undertaken toward that purpose using pendulums; one to measure momentum of the richocheted projectile and concomitant target ejecta, and a second to measure the momentum transferred from projectile to target. These experiments are briefly discussed.

  5. W Boson production at large transverse momentum.

    E-print Network

    Kidonakis, Nikolaos; Sabio Vera, Agustin

    ar X iv :h ep -p h/ 04 05 01 3v 1 3 M ay 2 00 4 Cavendish-HEP-04/13 DESY-04-071 W Boson Production at Large Transverse Momentum1 Nikolaos Kidonakisa and Agust´?n Sabio Verab a Cavendish Laboratory, University of Cambridge Madingley Road... -to-next-to-leading-order soft-gluon corrections are added, and the dependence on the factorization and renormalization scales is significantly reduced. 1Presented at the DIS 2004 Workshop, Strbske Pleso, Slovakia, 14-18 April, 2004. 1 Introduction W boson hadroproduction is a...

  6. Elastic electron scattering from methane at high momentum transfer

    Microsoft Academic Search

    M. Vos; M. R. Went; G. Cooper; C. A. Chatzidimitriou-Dreismann

    2008-01-01

    We describe elastic electron scattering data at high momentum transfer (between ≈20 and ≈40 au) from methane and Xe. Under these conditions there is a significant recoil energy transferred to the target and electrons scattered elastically from methane are separated into two peaks: one due to electrons scattered from carbon, and one due to electrons scattered from hydrogen. The separation

  7. Elastic electron scattering from methane at high momentum transfer

    Microsoft Academic Search

    M Vos; M R Went; G Cooper; C A Chatzidimitriou-Dreismann

    2008-01-01

    We describe elastic electron scattering data at high momentum transfer (between ?20 and ?40 au) from methane and Xe. Under these conditions there is a significant recoil energy transferred to the target and electrons scattered elastically from methane are separated into two peaks: one due to electrons scattered from carbon, and one due to electrons scattered from hydrogen. The separation

  8. A New Measurement of the Energy Dependence of Nuclear Transparency for Large Momentum Transfer 12C(p,2p) Scattering

    E-print Network

    E850 Collaboration; A. Leksanov; J. Alster; G. Asryan; Y. Averichev; D. Barton; V. Baturin; N. Bukhtoyarova; A. Carroll; S. Heppelmann; T. Kawabata; Y. Makdisi; A. Malki; E. Minina; I. Navon; H. Nicholson; A. Ogawa; Yu. Panebratsev; E. Piasetzky; A. Schetkovsky; S. Shimanskiy; A. Tang; J. W. Watson; H. Yoshida; D. Zhalov

    2000-09-08

    We present a new measurement of the energy dependence of nuclear transparency from AGS experiment E850, performed using the EVA solenoidal spectrometer, upgraded since 1995. Using a secondary beam from the AGS accelerator, we simultaneously measured $pp$ elastic scattering from hydrogen and $(p,2p)$ quasi-elastic scattering in carbon at incoming momenta of 5.9, 8.0, 9.0, 11.7 and 14.4 GeV/c. This incident momentum range corresponds to a $Q^{2}$ region between 4.8 and 12.7 (GeV/c)$^{2}$. The detector allowed us to do a complete kinematic analysis for the center-of-mass polar angles in the range $85^{\\circ}-90^{\\circ}$. We report on the measured variation of the nuclear transparency with energy and compare the new results with previous measurements.

  9. The polaron at large total momentum

    Microsoft Academic Search

    H. Spohn

    1988-01-01

    Proves that for dimensions d=1, 2 the polaron (with general dispersion relation and couplings) has a unique ground state for any value of the total momentum (particle+Bose field). For d>or=3 and for sufficiently small total momentum the author shows the existence of a unique ground state, extending however the domain of uniqueness known previously.

  10. 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.

  11. Momentum transfer-based attitude control of spacecraft with backstepping

    Microsoft Academic Search

    Baohua Lian; Hyochoong Bang

    2006-01-01

    A nonlinear control law design based upon the backstepping approach is addressed for attitude maneuver control of spacecraft by momentum transfer (MT) in the presence of disturbance. For MT, a traditional method usually applies constant torque as an input, which tends to produce significant residual oscillation. Enhanced methods such as optimal control can somewhat reduce the residual oscillation, but may

  12. The transfer angular momentum scheme in nuclear reactions

    SciTech Connect

    Robson, D. [Florida State Univ., Tallahassee, FL (United States)

    1994-12-31

    The use of transferred angular momentum quantum numbers to describe nuclear reactions is discussed without assuming a particular reaction mechanism. The Specific reaction {sup 12}C ({sup 6}Li,{alpha}){sup 14}N with polarized lithium will be discussed as an example of the formalism.

  13. Using Analytical Solutions at Large Momentum Transfer to Obtain Zero-Energy, Bound-State, Bethe-Salpeter Solutions of a Scalar and Spin-1/2 Fermion Exchanging Photons

    NASA Astrophysics Data System (ADS)

    Mainland, G. B.

    2015-05-01

    The existence of families of leptons and quarks plus the properties of their mass and spin spectra suggest that leptons and quarks might be relativistic bound states of a scalar and a spin-1/2 fermion interacting via minimal electrodynamics. To begin exploring the properties of this bound-state system, the Bethe-Salpeter equation describing bound states of a minimally interacting scalar and spin-1/2 fermion with arbitrary masses is solved in the ladder approximation when the bound-state energy is zero. At large momentum transfer solutions are calculated analytically, yielding boundary conditions that are determined by the coupling constant. Zero-energy solutions, including the coupling constant that is calculated as an eigenvalue, are obtained by expanding the solution in terms of basis functions that obey the boundary conditions, discretizing the Bethe-Salpeter equation, and solving the resulting generalized matrix eigenvalue equation numerically. Since the coupling constant appears both in the Bethe-Salpeter equation as an eigenvalue and in the basis functions, the generalized matrix eigenvalue equation is nonlinear in the coupling constant and is solved iteratively. The spectrum of the coupling constant is discrete.

  14. First Measurements of Form Factors of Pion, Kaon, Proton, and Hyperons for the Highest Timelike Momentum Transfers

    NASA Astrophysics Data System (ADS)

    Seth, Kamal K.

    2014-11-01

    Results of recent precision measurements of the electromagnetic form factors of the pion, kaon, proton, and the hyperons, ?0, ?0, ?+, ??, ?0, ??, at large timelike momentum transfers are presented. Evidence is found for diquark correlations in ?0, ?0 hyperons.

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

    Microsoft Academic Search

    D. J. Hamilton; V. H. Mamyan; K. A. Aniol; J. R. Annand; P. Y. Bertin; L. Bimbot; P. Bosted; J. R. Calarco; A. Camsonne; G. C. Chang; T.-H. Chang; Seonho Choi; E. Chudakov; A. Danagoulian; P. Degtyarenko; C. W. de Jager; A. Deur; D. Dutta; K. Egiyan; H. Gao; F. Garibaldi; O. Gayou; R. Gilman; A. Glamazdin; C. Glashausser; J. Gomez; J.-O. Hansen; D. Higinbotham; W. Hinton; T. Horn; C. Howell; T. Hunyady; C. E. Hyde-Wright; X. Jiang; M. K. Jones; M. Khandaker; A. Ketikyan; V. Kubarovsky; K. Kramer; G. Kumbartzki; G. Laveissière; J. Lerose; R. A. Lindgren; D. J. Margaziotis; P. Markowitz; K. McCormick; Z.-E. Meziani; R. Michaels; P. Moussiegt; S. Nanda; A. M. Nathan; D. M. Nikolenko; V. Nelyubin; B. E. Norum; K. Paschke; L. Pentchev; C. F. Perdrisat; E. Piasetzky; R. Pomatsalyuk; V. A. Punjabi; I. Rachek; A. Radyushkin; B. Reitz; R. Roche; M. Roedelbronn; G. Ron; F. Sabatie; A. Saha; N. Savvinov; A. Shahinyan; Y. Shestakov; S. Sirca; K. Slifer; P. Solvignon; P. Stoler; S. Tajima; V. Sulkosky; L. Todor; B. Vlahovic; L. B. Weinstein; K. Wang; B. Wojtsekhowski; H. Voskanyan; H. Xiang; X. Zheng; L. Zhu

    2005-01-01

    Compton scattering from the proton was investigated at s=6.9 GeV2 and t=-4.0 GeV2 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

  16. Low-momentum-transfer elastic electron scattering from 3He

    Microsoft Academic Search

    Z. M. Szalata; J. M. Finn; J. Flanz; F. J. Kline; G. A. Peterson; J. W. Lightbody Jr.; X. K. Maruyama; S. Penner

    1977-01-01

    Elastic electron scattering cross sections for 3He were measured relative to those of 12C in the range of momentum transfer squared between 0.032 and 0.34 fm-2. The 3He rms charge radius was determined from the data to be 1.89 +\\/- 0.05 fm. NUCLEAR REACTIONS 3He(e, e), E=28.8-95.0 MeV; measured sigma(E) at theta=75° deduced rms charge radius.

  17. 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.

  18. Momentum transfer within a porous medium. II. Stress boundary condition

    NASA Astrophysics Data System (ADS)

    Minale, Mario

    2014-12-01

    In this paper, we derive a boundary condition at the interface between a free fluid and a porous medium stating that the stress is transferred both to the fluid within the porous medium and to the solid skeleton. A zero stress jump is obtained so that the total stress is preserved at the interface. The boundary condition is obtained with the volume averaging method following the approach of Ochoa-Tapia and Whitaker ["Momentum transfer at the boundary between a porous medium and a homogeneous fluid—I. Theoretical development," Int. J. Heat Mass Transfer 38(14), 2635-2646 (1995)], but starting from the momentum balances written on the fluid and on the solid of the porous region, the latter was derived in part I of this paper. In the same way, also the boundary condition at the interface between a porous medium and a homogeneous solid is obtained. Both boundary conditions describe the equilibrium of forces at the interface, where part of the stress is carried by the solid skeleton and part by the fluid within the porous medium. With the derived boundary conditions, together with the stress transfer equation within the solid skeleton, it is now possible to satisfy the overall force equilibrium on a shear cell partially filled with a porous medium.

  19. Large-uncertainty intelligent states for angular momentum and angle

    E-print Network

    Goette, J B; Franke-Arnold, S; Barnett, S M; Goette, Joerg B.; Zambrini, Roberta; Franke-Arnold, Sonja; Barnett, Stephen M.

    2005-01-01

    The equality in the uncertainty principle for linear momentum and position is obtained for states which also minimize the uncertainty product. However, in the uncertainty relation for angular momentum and angular position both sides of the inequality are state dependent and therefore the intelligent states, which satisfy the equality, do not necessarily give a minimum for the uncertainty product. In this paper, we highlight the difference between intelligent states and minimum uncertainty states by investigating a class of intelligent states which obey the equality in the angular uncertainty relation while having an arbitrarily large uncertainty product. To develop an understanding for the uncertainties of angle and angular momentum for the large-uncertainty intelligent states we compare exact solutions with analytical approximations in two limiting cases.

  20. Large-uncertainty intelligent states for angular momentum and angle

    E-print Network

    Joerg B. Goette; Roberta Zambrini; Sonja Franke-Arnold; Stephen M. Barnett

    2005-10-20

    The equality in the uncertainty principle for linear momentum and position is obtained for states which also minimize the uncertainty product. However, in the uncertainty relation for angular momentum and angular position both sides of the inequality are state dependent and therefore the intelligent states, which satisfy the equality, do not necessarily give a minimum for the uncertainty product. In this paper, we highlight the difference between intelligent states and minimum uncertainty states by investigating a class of intelligent states which obey the equality in the angular uncertainty relation while having an arbitrarily large uncertainty product. To develop an understanding for the uncertainties of angle and angular momentum for the large-uncertainty intelligent states we compare exact solutions with analytical approximations in two limiting cases.

  1. 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

  2. Three-fluid plasmas in star formation II. Momentum transfer rate coefficients

    E-print Network

    Cecilia Pinto; Daniele Galli

    2008-04-17

    The charged component of the insterstellar medium consists of atomic and molecular ions, electrons, and charged dust grains, coupled to the local Galactic magnetic field. Collisions between neutral particles (mostly atomic or molecular hydrogen) and charged species, and between the charged species themselves, affect the magnetohydrodynamical behaviour of the medium and the dissipation of electric currents. The friction force due to elastic collisions between particles of different species in the multi-component interstellar plasma is a nonlinear function of the temperature of each species and the Mach number of the relative drift velocity. The aim of this paper is to provide an accurate and, as far as possible, complete set of momentum transfer rate coefficients for magnetohydrodynamical studies of the interstellar medium. Momentum transfer rates are derived from available experimental data and theoretical calculations of cross sections within the classic approach developed by Boltzmann and Langevin for a wide range of values of the temperature and the drift velocity. Accurate numerical values for momentum transfer rates are obtained and fitted to simple analytical formulae expressing the dependence of the results on the gas temperature and the relative drift velocity. The often used polarization approximation is in satisfactory agreement with our results only for collisions between H2and molecular ions (HCO+, H3+). For other kinds of collisions, the polarization approximation fails by large factors, and must be replaced by more accurate expressions.

  3. Large Fixed Objects, Such as Fixed Mirrors, Impacted by Photons Do Not Provide Which-Way Information Due to Momentum Transfer: Implications for A Delayed Choice Experiment to Send Information Immediately Between 2 Paired Particles

    NASA Astrophysics Data System (ADS)

    Snyder, Douglas

    2015-04-01

    If a photon impacts a much larger fixed object, the momentum transfer from the photon to the fixed object is essentially undetectable. This principle is the basis for a Mach Zehnder interferometer where fixed full-silvered and half-silvered mirrors do not provide which way information when impacted by an incoming photon. Kim relied on fixed mirrors impacted by photons to demonstrate quantum erasure. If the principle did not work, Kim would not have obtained symmetric and anti-symmetric interference. The present experiment relies on delayed choices for idler photons which initially possess ww information that immediately affect the distribution of signal photons initially entangled with the idler photons and for which the idler photons provide ww information. It relies on the principle noted. In the case of the present experiment, one of those fixed objects is an optical microcavity that is situated at the crossroads of two possible paths for the idler photon. The delayed choice concerns whether to maintain or eliminate the entanglement before any measurements are made. If the idler photon enters the microcavity filled with photons in the same mode as the idler photon, the entanglement is eliminated. The resulting distribution of the paired signal photons with this choice shows interference. If the choice is not to send the idler photon toward the microcavity and preserve the which-way information of the idler photons, the resulting distribution of the paired signal photons shows ww information.

  4. Momentum and heat transfer in a complex recirculating flow

    SciTech Connect

    Rhee, H.S.

    1987-01-01

    Three-dimensional and turbulent recirculating flows in enclosed spaces occur in many engineering situations. Accurate measurements of momentum- and heat-transfer characteristics are needed for direct engineering-design applications and for developments of numerical-simulation codes of these flows. A facility to generate recirculating flows driven by buoyancy and/or shear forces in a rectangular cavity was constructed to model such flows. Also, a visualization technique, involving temperature-sensitive liquid-crystal microcapsules, was developed to visualize the temperature and velocity fields simultaneously in any flow plane. Two flow cases were studied: (1) natural convection driven by buoyancy in a bottom-heated cavity, with Gr = 2.4 10/sup 7/, and (2) mixed-convection driven by shear force from a moving lid and buoyancy, with Gr = 2.4 x 10/sup 7/ and Re = 3200. In the mixed-convection case, Gr/Re/sup 2/ = 2.3, indicating that buoyancy and shear forces acting on the flow are comparable. In addition to the flow/temperature visualizations, measurements were made of velocity, temperature, and surface heat flux. Overall heat-transfer measurements were conducted for a wide range of the mixed-convection parameter, Gr/Re/sup 2/, in the cavity. Smooth transitions were found from natural convection to forced convection. The mixed convection regime was found in 0.5 < Gr/Re/sup 2/ < 80, the upper found of 80 being larger than that of flat plate data (about 10). This was probably due to heat-transfer enhancement by the TGL vortices.

  5. On the momentum transfer maneuver for initial acquisition using multi-wheels - Its analysis and application

    Microsoft Academic Search

    Song J. Dong; Jun'ichiro Kawaguchi; Hiroki Matsuo; Keiken Ninomiya; Ken Maeda

    1992-01-01

    This paper proposes a control law that stabilizes momentum transfer maneuver using multiwheels. The law is proved analytically via Liapunov's direct method. As another consequence, this paper point out equilibrium 'singular states' which closed momentum transfer control may fall into, and from which any evasive path cannot be found. Sufficient conditions are provided so that such singular states can be

  6. 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

  7. The Momentum Transfer and Target Mass Dependence of the

    NASA Astrophysics Data System (ADS)

    Boberg, Paul Richard

    In order to study some of the exclusive structure and reaction dynamics in the quasi elastic region, (e,e ^' p) measurements on ^{12}C and ^{63 }Cu were performed. These measurements attempt to isolate the nuclear reaction mechanism contribution from the off shell e-p cross section. We performed measurements at five three-momentum transfer |vec {rm q}| for each target, varying |vec{rm q} | by changing the electron scattering angle theta_{rm e^' }. The measurements were performed at the MIT -Bates Linear Accelerator Center. The measurements were compared with Impulse Approximation (IA) predictions, providing quantitative tests of the approximations involved. The measurements for the p-shells were emphasized: the ^{12}C 1p-shell and the ^{63}Cu 2p-shell. For both targets, missing energy spectra were extract up to 50 MeV. The data from the second major shell regions, the ^{12}C s-shell and the ^{63}Cu f-s shell, were also compared with IA predictions. Finally, the ^{12}C results were compared with existing ^{12}C(e,e ^' p) results.

  8. Observation of Orbital Angular Momentum Transfer between Acoustic and Optical Vortices in Optical Fiber

    Microsoft Academic Search

    Pedram Z. Dashti; Fares Alhassen; Henry P. Lee

    2006-01-01

    Acousto-optic interaction in optical fiber is examined from the perspective of copropagating optical and acoustic vortex modes. Calculation of the acousto-optic coupling coefficient between different optical modes leads to independent conservation of spin and orbital angular momentum of the interacting photons and phonons. We show that the orbital angular momentum of the acoustic vortex can be transferred to a circularly

  9. Transverse Momentum Transfer in Atom-Light Scattering B.A. van Tiggelen,1

    E-print Network

    Paris-Sud XI, Université de

    Transverse Momentum Transfer in Atom-Light Scattering B.A. van Tiggelen,1 A. Nussle,1 and G is moving. Light scattering exchanges momentum between mat- ter and radiation, and thus induces a force on the matter. Classical light scattering is well known to be affected by a magnetic field. A specific feature

  10. 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.

  11. Angular momentum transfer in low velocity oblique impacts - Implications for asteroids

    NASA Astrophysics Data System (ADS)

    Yanagisawa, Masahisa; Eluszkiewicz, Janusz; Ahrens, Thomas J.

    1991-12-01

    An experimental study has been conducted for the low-velocity oblique impact efficiency of angular momentum transfer, which is defined as that fraction of incident angular momentum that is transferred to the rotation of a target. The results obtained suggest that more energetic impacts are able to transfer angular momentum more efficiently. In the cases of ricochetted projectiles, the fraction of angular momentum carried off by the ejecta was noted to be less than 30 percent. It is suggested that, if asteroid spin rates are due to mutual noncatastrophic collisions and the taxonomic classes are indicative of bulk properties, the differences between corresponding spin rates will be smaller than expected from a consideration of relative strength and density alone.

  12. 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…

  13. Momentum Transfer and Viscosity from Proton-Hydrogen Collisions Relevant to Shocks and Other Astrophysical Environments

    SciTech Connect

    Schultz, David Robert [ORNL; Krstic, Predrag S [ORNL; Lee, Teck G [ORNL; Raymond, J. C. [Harvard-Smithsonian Center for Astrophysics

    2008-01-01

    The momentum transfer and viscosity cross sections for proton-hydrogen collisions are computed in the velocity range of ~200-20,000 km s-1 relevant to a wide range of astrophysical environments such as SNR shocks, the solar wind, winds within young stellar objects or accretion disks, and the interstellar protons interacting with the heliosphere. A variety of theoretical approaches are used to arrive at a best estimate of these cross sections in this velocity range that smoothly connect with very accurate results previously computed for lower velocities. Contributions to the momentum transfer and viscosity cross sections from both elastic scattering and charge transfer are included.

  14. Large-uncertainty intelligent states for angular momentum and angle

    Microsoft Academic Search

    Jörg B. Götte; Roberta Zambrini; Sonja Franke-Arnold; Stephen M. Barnett

    2005-01-01

    The equality in the uncertainty principle for linear momentum and position is obtained for states which also minimize the uncertainty product. However, in the uncertainty relation for angular momentum and angular position both sides of the inequality are state dependent and therefore the intelligent states, which satisfy the equality, do not necessarily give a minimum for the uncertainty product. In

  15. Optical angular-momentum transfer to trapped absorbing particles

    Microsoft Academic Search

    M. E. J. Friese; J. Enger; H. Rubinsztein-Dunlop; N. R. Heckenberg

    1996-01-01

    Particle rotation resulting from the absorption of light carrying angular momentum has been measured. When absorbing CuO particles (1-5μm) were trapped in a focused {open_quote}{open_quote}donut{close_quote}{close_quote} laser beam, they rotated, due to the helical phase structure of the beam. Changing the polarization of the light from plane to circular caused the rotation frequency to increase or decrease, depending on the sense

  16. 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.

  17. Large-uncertainty intelligent states for angular momentum and angle

    Microsoft Academic Search

    Roberta Zambrini; Sonja Franke-Arnold; Stephen M. Barnett

    2006-01-01

    The equality in the uncertainty principle for linear momentum and position is\\u000aobtained for states which also minimize the uncertainty product. However, in\\u000athe uncertainty relation for angular momentum and angular position both sides\\u000aof the inequality are state dependent and therefore the intelligent states,\\u000awhich satisfy the equality, do not necessarily give a minimum for the\\u000auncertainty product. In

  18. The relation between momentum transfer and capture and total scattering cross sections for ion-dipole collisions

    NASA Technical Reports Server (NTRS)

    Dugan, J. V., Jr.

    1972-01-01

    Numerical values of momentum transfer cross sections sigma sub m for ion-dipole collisions are compared with the corresponding capture cross sections sigma sub c as a function of ion velocity and rotational temperature. For values of dipole moment mu from 1 to 4 Debyes the sigma sub m/sigma sub c ratio is in the range 1.2 to 2.0 (roughly). This is in contrast to the simple relation for Langevin collisions where sigma sub m/sigma sub c is equal to or approximately 1.10 independent of polarizability of the target atom. At low temperatures, the momentum transfer cross sections can be as large as 2000 A squared but they are only about 15 to 30 percent of the total scattering cross sections sigma sub S.

  19. Mass and momentum transfer in commercial blood oxygenators

    Microsoft Academic Search

    S. R. Wickramasinghe; Binbing Han

    2002-01-01

    In modern blood oxygenators, microporous membranes (flat sheet or hollow fibre) are used to separate the blood and gas phases. Blood flows on one side of the membrane while gas (usually oxygen or air) flows on the other side. Since the membranes used are hydrophobic (e.g., polypropylene, Teflon), the pores are gas filled resulting in a negligible membrane mass transfer

  20. Mass and momentum transfer in hollow fibre blood oxygenators

    Microsoft Academic Search

    S. R. Wickramasinghe; J. D. Garcia; Binbing Han

    2002-01-01

    Mass transfer and friction factor correlations for microporous hollow fibre blood oxygenators (BOs) have been determined experimentally. Water and glycerol water solutions were used as a substitute for blood. The diffusion of oxygen into and out of water and glycerol water solutions has been studied. The liquid stream flowed outside and across bundles of woven hollow fibres while the gas

  1. Momentum Transfer during Shock Diffraction over Metal Particles in Condensed Explosives

    NASA Astrophysics Data System (ADS)

    Zhang, F.; Thibault, P. A.; Link, R.; Gonor, A. L.

    2001-06-01

    For detonation propagation in a condensed explosive with metal particles, the time scale for a particle to cross the leading shock front could be comparable to the velocity relaxation time related to viscous drag. This would result in a significant momentum transfer from the explosive to the particles during the shock diffraction, thus influencing the initiation and detonation structure. Therefore, the classic assumption of a "non-momentum-transfer leading shock" used in the multiphase detonation modeling may not be valid. This paper aimed to prove this concept using numerical simulations in liquid explosives and RDX with compressible particles at various particle parameters under conditions of detonation pressure. The results showed that immediately behind the shock front the velocity of particles such as Al and Mg can achieve 80 - 90 of the explosive. A quasi-1D analysis was also conducted and a linear mixing model was proposed to describe the momentum transfer during the shock diffraction.

  2. Observation of orbital angular momentum transfer between acoustic and optical vortices in optical fiber.

    PubMed

    Dashti, Pedram Z; Alhassen, Fares; Lee, Henry P

    2006-02-01

    Acousto-optic interaction in optical fiber is examined from the perspective of copropagating optical and acoustic vortex modes. Calculation of the acousto-optic coupling coefficient between different optical modes leads to independent conservation of spin and orbital angular momentum of the interacting photons and phonons. We show that the orbital angular momentum of the acoustic vortex can be transferred to a circularly polarized fundamental optical mode to form a stable optical vortex in the fiber carrying orbital angular momentum. The technique provides a useful way of generating stable optical vortices in the fiber medium. PMID:16486822

  3. 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.

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

    NASA Astrophysics Data System (ADS)

    Donaire, M.; van Tiggelen, B. A.; Rikken, G. L. J. A.

    2015-06-01

    In a recent publication [1] 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. Real Compton Scattering on Proton at High Momentum Transfers

    SciTech Connect

    A. Danagoulian; D.J. Hamilton; C.E. Hyde-Wright; V.H. Mamyan; A.M. Nathan; M. Roedelbronn; B. Wojtsekhowski

    2005-06-01

    The E99-114 experiment was carried out to measure the cross sections for Real Compton Scattering (RCS) on the proton in the kinematic range s = 5-11 GeV{sup 2}, -t = 2-7 GeV{sup 2}. In addition, a measurement of longitudinal and transverse polarization transfers was made at s = 6.9 GeV{sup 2} and -t = 4.0 GeV{sup 2}. These measurements were done to test the existing theoretical mechanisms for this process and will possibly lead to the determination of RCS form factors which are related to the Generalized Parton Distributions (GPD). The experiment was conducted in Hall A of Thomas Jefferson National Accelerator Facility (Jefferson Lab). Final results of polarization transfer measurements are presented.

  6. Momentum Transfer during Shock Interaction with Metal Particles in Condensed Explosives

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Thibault, Paul A.; Link, Rick; Gonor, Alexander L.

    2002-07-01

    Detonation propagation in a condensed explosive with compressible metal particles can result in significant momentum transfer between the explosive and the particles during the shock-particle interaction. Consequently, the classic assumption of a "non-momentum-transfer shock" used in multiphase continuum detonation initiation and propagation models may not be valid. This paper addresses this issue by performing numerical and theoretical calculations in liquid explosives and RDX with various compressible metal particles under conditions of detonation pressure. The results showed that immediately behind the shock front the velocity of particles such as Al and Mg can achieve 60 - 94 % the value of the shocked velocity of the explosive.

  7. Hydromagnetics of Advective Accretion Flows around Black Holes: Removal of Angular Momentum by Large-scale Magnetic Stresses

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Banibrata; Chatterjee, Koushik

    2015-07-01

    We show that the removal of angular momentum is possible in the presence of large-scale magnetic stresses in geometrically thick, advective, sub-Keplerian accretion flows around black holes in steady state, in the complete absence of ?-viscosity. The efficiency of such an angular momentum transfer could be equivalent to that of ?-viscosity with ? = 0.01–0.08. Nevertheless, the required field is well below its equipartition value, leading to a magnetically stable disk flow. This is essentially important in order to describe the hard spectral state of the sources when the flow is non/sub-Keplerian. We show in our simpler 1.5 dimensional, vertically averaged disk model that the larger the vertical-gradient of the azimuthal component of the magnetic field is, the stronger the rate of angular momentum transfer becomes, which in turn may lead to a faster rate of outflowing matter. Finding efficient angular momentum transfer in black hole disks via magnetic stresses alone, is very interesting when the generic origin of ?-viscosity is still being explored.

  8. Hydromagnetics of advective accretion flows around black holes: Removal of angular momentum by large scale magnetic stresses

    E-print Network

    Mukhopadhyay, Banibrata

    2015-01-01

    We show that the removal of angular momentum is possible in the presence of large scale magnetic stresses in geometrically thick, advective, sub-Keplerian accretion flows around black holes in steady-state, in the complete absence of alpha-viscosity. The efficiency of such an angular momentum transfer could be equivalent to that of alpha-viscosity with alpha=0.01-0.08. Nevertheless, required field is well below its equipartition value, leading to a magnetically stable disk flow. This is essentially important in order to describe the hard spectral state of the sources, when the flow is non/sub-Keplerian. We show in our simpler 1.5-dimensional, vertically averaged disk model that larger the vertical-gradient of azimuthal component of magnetic field, stronger the rate of angular momentum transfer is, which in turn may lead to a faster rate of outflowing matter. Finding efficient angular momentum transfer, in black hole disks, via magnetic stresses alone is very interesting, when the generic origin of alpha-visco...

  9. Giant plasmonic energy and momentum transfer on the nanoscale

    NASA Astrophysics Data System (ADS)

    Durach, Maxim

    We have developed a general theory of the plasmonic enhancement of many-body phenomena resulting in a closed expression for the surface plasmon-dressed Coulomb interaction. It is shown that this interaction has a resonant nature. We have also demonstrated that renormalized interaction is a long-ranged interaction whose intensity is considerably increased compared to bare Coulomb interaction over the entire region near the plasmonic nanostructure. We illustrate this theory by re-deriving the mirror charge potential near a metal sphere as well as the quasistatic potential behind the so-called perfect lens at the surface plasmon (SP) frequency. The dressed interaction for an important example of a metal--dielectric nanoshell is also explicitly calculated and analyzed. The renormalization and plasmonic enhancement of the Coulomb interaction is a universal effect, which affects a wide range of many-body phenomena in the vicinity of metal nanostructures: chemical reactions, scattering between charge carriers, exciton formation, Auger recombination, carrier multiplication, etc. We have described the nanoplasmonic-enhanced Forster resonant energy transfer (FRET) between quantum dots near a metal nanoshell. It is shown that this process is very efficient near high-aspect-ratio nanoshells. We have also obtained a general expression for the force exerted by an electromagnetic field on an extended polarizable object. This expression is applicable to a wide range of situations important for nanotechnology. Most importantly, this result is of fundamental importance for processes involving interaction of nanoplasmonic fields with metal electrons. Using the obtained expression for the force, we have described a giant surface-plasmon-induced drag-effect rectification (SPIDER), which exists under conditions of the extreme nanoplasmonic confinement. Under realistic conditions in nanowires, this giant SPIDER generates rectified THz potential differences up to 10V and extremely strong electric fields up to 105--10 6 V/cm. It can serve as a powerful nanoscale source of THz radiation. The giant SPIDER opens up a new field of ultraintense THz nanooptics with wide potential applications in nanotechnology and nanoscience, including microelectronics, nanoplasmonics, and biomedicine. Additionally, the SPIDER is an ultrafast effect whose bandwidth for nanometric wires is 20 THz, which allows for detection of femtosecond pulses on the nanoscale. INDEX WORDS: Nanoplasmonics, Nanoplasmonic renormalization of Coulomb interaction, Surface-plasmon enhanced Forster energy transfer (FRET), Surface-plasmon-induced drag-effect rectification (SPIDER), Nanotechnology, Plasmonics on the nanoscale, Localized surface plasmons (LSPs), Surface plasmon polaritons (SPPs)

  10. 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

  11. 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

  12. Measurement of the total optical angular momentum transfer in optical tweezers

    Microsoft Academic Search

    Simon Parkin; Gregor Knöner; Timo A. Nieminen; Norman R. Heckenberg; Halina Rubinsztein-Dunlop

    2006-01-01

    We describe a way to determine the total angular momentum, both spin and orbital, transferred to a particle trapped in optical tweezers. As an example an LG02 mode of a laser beam with varying degrees of circular polarisation is used to trap and rotate an elongated particle with a well defined geometry. The method successfully estimates the total optical torque

  13. Energy and Momentum Transfer via Coulomb Frictions in Relativistic Two Fluids

    E-print Network

    Katsuaki Asano; Shizuo Iwamoto; Fumio Takahara

    2006-11-04

    We numerically calculate the energy and momentum transfer rates due to Coulomb scattering between two fluids moving with a relative velocity. The results are fitted by simple functions. The fitting formulae are useful to simulate outflows from active galactic nuclei and compact high energy sources.

  14. 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

  15. Fluctuation theorem for entropy production during effusion of an ideal gas with momentum transfer

    E-print Network

    Kawai, Ryoichi

    , for example, the theory of linear irreversible processes 2 and the fluctuation- dissipation theorem 3 . OverFluctuation theorem for entropy production during effusion of an ideal gas with momentum transfer and explicitly verify the thermo- dynamic fluctuation theorem, thereby directly exhibiting its extended

  16. 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

  17. Coupling a small torsional oscillator to large optical angular momentum

    NASA Astrophysics Data System (ADS)

    Shi, Hao; Bhattacharya, Mishkatul

    2013-05-01

    We propose a new optomechanical system to achieve torsional optomechanics. Our system is composed of a windmill-shaped dielectric optically trapped within a cavity interacting with Laguerre-Gaussian cavity modes with both angular and radial nodes. Compared to existing configurations, our proposal enables small mechanical oscillators to interact with the in-principle unlimited orbital angular momentum that can be carried by a single photon, and therefore allows the generation of scalable optomechanical coupling. We propose a new optomechanical system to achieve torsional optomechanics. Our system is composed of a windmill-shaped dielectric optically trapped within a cavity interacting with Laguerre-Gaussian cavity modes with both angular and radial nodes. Compared to existing configurations, our proposal enables small mechanical oscillators to interact with the in-principle unlimited orbital angular momentum that can be carried by a single photon, and therefore allows the generation of scalable optomechanical coupling. Supported by Research Corporation for Science Advancement.

  18. Measurement of quasi-elastic 12C(p,2p) scattering at high momentum transfer

    E-print Network

    Y. Mardor; J. Aclander; J. Alster; D. Barton; G. Bunce; A. Carroll; N. Christensen; H. Courant; S. Durrant; S. Gushue; S. Heppelmann; E. Kosonovsky; I. Mardor; M. Marshak; Y. Makdisi; E. D. Minor; I. Navon; H. Nicholson; E. Piasetzky; T. Roser; J. Russell; C. S. Sutton; M. Tanaka; C. White; J-Y Wu

    1997-10-16

    We measured the high-momentum quasi-elastic 12C(p,2p) reaction (at center of mass angle near 90 degrees) for 6 and 7.5 GeV/c incident protons. The three-momentum components of both final state protons were measured and the missing energy and momentum of the target proton in the nucleus were determined. The validity of the quasi-elastic picture was verified up to Fermi momenta of about 450 MeV/c, where it might be questionable. Transverse and longitudinal Fermi momentum distributions of the target proton were measured and compared to independent particle models which do not reproduce the large momentum tails. We also observed that the transverse Fermi distribution gets wider as the longitudinal component increases in the beam direction, in contrast to a simple Fermi gas model.

  19. Spin Momentum Transfer and Oersted Field Induce a Vortex Nano-Oscillator in Thin Ferromagnetic Film Devices

    E-print Network

    Hoefer, Mark

    in a thin ferromagnetic film that includes the Oersted magnetic field contribution is presented. We consider-momentum transfer (SMT) in a thin magnetic multilayer has potential appli- cations in communications and high-momentum transfer induced magnetodynamics in the presence of an Oersted field. Thin film, multilayer point contact

  20. Charge Form Factor of the Neutron at Low Momentum Transfer from the H?2(e?,e'n)H1 Reaction

    NASA Astrophysics Data System (ADS)

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

    2008-07-01

    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 GEn/GMn was extracted from the beam-target vector asymmetry AedV at four-momentum transfers Q2=0.14, 0.20, 0.29, and 0.42(GeV/c)2.

  1. Charge Form Factor of the Neutron at Low Momentum Transfer from the H-->2(e-->,e'n)H1 Reaction

    Microsoft Academic Search

    E. Geis; M. Kohl; V. Ziskin; T. Akdogan; H. Arenhövel; 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; H. Kolster; T. Lee; A. Maschinot; J. Matthews; K. McIlhany; N. Meitanis; R. G. Milner; J. Rapaport; R. P. Redwine; J. Seely; S. Sirca; A. Sindile; T. Smith; M. Steadman; B. Tonguc; C. Tschalaer; E. Tsentalovich; W. Turchinetz; Y. Xiao; W. Xu; C. Zhang; Z. Zhou; T. Zwart

    2008-01-01

    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

  2. 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.

  3. 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

  4. Mass transfer instabilities due to angular momentum flows in close binaries

    SciTech Connect

    Verbunt, F.; Rappaport, S.

    1988-09-01

    The paper investigates the onset of dynamical mass transfer instabilities due to angular momentum flows in close low-mass binaries. Allowance is made for the finite growth time of the instability. The results are applied to the formation of single millisecond pulsars in the galactic disk and it is found that mass transfer from a white dwarf onto a neutron star is dynamically unstable for white dwarf masses greater than about 0.5 solar masses. This lower limit for unstable mass transfer is somewhat larger than that found previously. A further application is the formation of long period and ultrashort-period white-dwarf/neutron-star binaries, via mass transfer from a giant to a neutron star. It is found that incipient mass transfer from an approximately 0.8-solar mass giant to an approximately 1.2-solar mass neutron star occurs on a sufficiently slow time scale for an accretion disk to form. 37 references.

  5. 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.

  6. Three-fluid plasmas in star formation II. Momentum transfer rate coefficients

    E-print Network

    Pinto, Cecilia

    2008-01-01

    The charged component of the insterstellar medium consists of atomic and molecular ions, electrons, and charged dust grains, coupled to the local Galactic magnetic field. Collisions between neutral particles (mostly atomic or molecular hydrogen) and charged species, and between the charged species themselves, affect the magnetohydrodynamical behaviour of the medium and the dissipation of electric currents. The friction force due to elastic collisions between particles of different species in the multi-component interstellar plasma is a nonlinear function of the temperature of each species and the Mach number of the relative drift velocity. The aim of this paper is to provide an accurate and, as far as possible, complete set of momentum transfer rate coefficients for magnetohydrodynamical studies of the interstellar medium. Momentum transfer rates are derived from available experimental data and theoretical calculations of cross sections within the classic approach developed by Boltzmann and Langevin for a wid...

  7. Density matrix reconstruction of a large angular momentum

    NASA Astrophysics Data System (ADS)

    Klose, Gerd

    2001-10-01

    A complete description of the quantum state of a physical system is the fundamental knowledge necessary to statistically predict the outcome of measurements. In turning this statement around, Wolfgang Pauli raised already in 1933 the question, whether an unknown quantum state could be uniquely determined by appropriate measurements-a problem that has gained new relevance in recent years. In order to harness the prospects of quantum computing, secure communication, teleportation, and the like, the development of techniques to accurately control and measure quantum states has now become a matter of practical as well as fundamental interest. However, there is no general answer to Pauli's very basic question, and quantum state reconstruction algorithms have been developed and experimentally demonstrated only for a few systems so far. This thesis presents a novel experimental method to measure the unknown and generally mixed quantum state for an angular momentum of arbitrary magnitude. The (2F + 1) x (2F + 1) density matrix describing the quantum state is hereby completely determined from a set of Stern-Gerlach measurements with (4F + 1) different orientations of the quantization axis. This protocol is implemented for laser cooled Cesium atoms in the 6S1/2(F = 4) hyperfine ground state manifold, and is applied to a number of test states prepared by optical pumping and Larmor precession. A comparison of the input and the measured states shows successful reconstructions with fidelities of about 0.95.

  8. 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.

  9. Collective braking mechanism in plasma and the momentum-transfer distribution function

    Microsoft Academic Search

    S. N. Gordienko; L. D. Landau

    1999-01-01

    It is shown that the lower limit in the Coulomb logarithm is determined by the collective behavior of the plasma and not binary\\u000a collisions with small impact parameters. For this reason, the assumption that the “largest” momentum transfer is determined\\u000a by binary collisions results in a factor of two overestimation of the numerical coefficient in the second moment of the

  10. 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.

  11. Momentum transfer in the one-dimensional impact of spaced plates

    NASA Technical Reports Server (NTRS)

    Abbott, R. D.; Bjorkman, Michael D.

    1991-01-01

    The two-dimensional hydrocode CSQ III was used to calculate the fraction of momentum transferred from a flyer plate to a target of two spaced plates. The effect of the vaporization phase transition, as calculated with the ANEOS analytical complete three-phase equation of state, was estimated. Application of these results to the protection of spacecraft from meteoroids and orbital debris is discussed.

  12. The energy dependence of the hard exclusive diffractive processes in pQCD as the function of momentum transfer

    NASA Astrophysics Data System (ADS)

    Blok, B.; Frankfurt, L.; Strikman, M.

    2010-05-01

    We predict the dependence on energy of photo (electro) production processes: ?( ? *)+ p? V+ X with large rapidity gap at small x and large momentum - t transferred to V in pQCD. Here V is a heavy quarkonium ( J/ ?, ?) or longitudinally polarized light vector meson (in the electroproduction processes), etc. In the kinematics of HERA we calculate the dependence on energy of cross sections of these processes as the function of momentum transfer t, photon virtuality Q 2 and/or quarkonium mass. In the kinematical region Q02le -t? Q2+M2V the nontrivial energy dependence of the cross section for the vector meson production due to the photon scattering off a parton follows within QCD from the summing of the double logarithmic terms. In the second regime -tge Q2+M2V within DGLAP approximation in all orders of perturbation theory the qbar{q}-parton elastic cross section is energy independent. We show that the correct account of the double logarithmic terms and of the gluon radiation including kinematical constraints removes the disagreement between pQCD calculations and recent HERA experimental data. The explicit formula for the dependence of the differential cross section d2?/dt dxJ of these processes on s_{?^{*}N} is obtained. We show that perturbative Pomeron type behavior may reveal itself only at energies significantly larger than those available at HERA. In addition we evaluate the energy dependence of DVCS processes.

  13. Higher-twist dynamics in large transverse momentum hadron production.

    PubMed

    Arleo, François; Brodsky, Stanley J; Hwang, Dae Sung; Sickles, Anne M

    2010-08-01

    A scaling law analysis of the world data on inclusive large-p(?) hadron production in hadronic collisions is carried out. Significant deviations from leading-twist perturbative QCD predictions at next-to-leading order are observed, particularly at high x(?)=2p(?)/sqrt[s]. In contrast, the production of prompt photons and jets exhibits near-conformal scaling behavior in agreement with leading-twist expectations. These results indicate a non-negligible contribution of higher-twist processes in large-p(?) hadron production, where the hadron is produced directly in the hard subprocess, rather than by quark and gluon fragmentation. Predictions for the scaling exponents at RHIC and LHC are given. Triggering on isolated large-p(?) hadron production will enhance the higher-twist processes. We also note that the use of isolated hadrons as a signal for new physics can be affected by the presence of direct hadron production. PMID:20867975

  14. 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.

  15. 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.

  16. Resonant transfer and excitation: Dependence on projectile charge state and target-electron momentum distribution

    SciTech Connect

    Tanis, J.A.; Bernstein, E.M.; Clark, M.W.; Graham, W.G.; McFarland, R.H.; Morgan, T.J.; Mowat, J.R.; Mueller, D.W.; Mueller, A.; Stockli, M.P.

    1986-09-01

    Resonant transfer and excitation (RTE) involving simultaneous electron capture and projectile K-shell excitation has been measured for calcium ions in charge states ranging from neon-like to hydrogen-like incident on molecular hydrogen over an energy range 100--370 MeV. The results establish a projectile charge-state dependence for RTE and provide a detailed test of theoretical calculations. The effect of the target-electron momentum distribution on the RTE process is demonstrated by comparing with previous results for calcium ions incident on helium.

  17. Angular momentum-Large-scale structure alignments in LCDM models and the SDSS

    E-print Network

    Dante Paz; Federico Stasyszyn; Nelson Padilla

    2008-06-27

    We study the alignments between the angular momentum of individual objects and the large-scale structure in cosmological numerical simulations and real data from the Sloan Digital Sky Survey, Data Release 6. To this end we measure anisotropies in the two point cross-correlation function around simulated halos and observed galaxies, studying separately the 1- and 2-halo regimes. The alignment of the angular momentum of dark-matter haloes in LCDM simulations is found to be dependent on scale and halo mass. At large distances (2-halo regime), the spins of high mass haloes are preferentially oriented in the direction perpendicular to the distribution of matter; lower mass systems show a weaker trend that may even reverse to show an angular momentum in the plane of the matter distribution. In the 1-halo term regime, the angular momentum is aligned in the direction perpendicular to the matter distribution; the effect is stronger than for the 1-halo term and increases for higher mass systems. On the observational side, we focus our study on galaxies in the Sloan Digital Sky Survey, Data Release 6 (SDSS-DR6) with elongated apparent shapes, and study alignments with respect to the major semi-axis. We find an excess of structure in the direction of the major semi-axis for all samples; the red sample shows the highest alignment (2.7+-0.08%) and indicates that the angular momentum of flattened spheroidals tends to be perpendicular to the large-scale structure. (Abridged)

  18. 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.

  19. Longitudinal structure function of the proton at low momentum transfer and extended constituents

    NASA Astrophysics Data System (ADS)

    Simula, Silvano

    2003-11-01

    Recent data on the (inelastic) Nachtmann moments of the unpolarized proton structure function F2p, obtained at low momentum transfer with the CLAS detector at Jefferson Lab., have been interpreted in terms of the dominance of the elastic coupling of the virtual photon with extended substructures inside the proton. Adopting the same constituent form factors and the same light-front wave function describing the motion of the constituents in the proton, the (inelastic) Nachtmann moments of the longitudinal proton structure function FLp are calculated (without further parameters) for values of the squared four-momentum transfer 0.2?Q2 (GeV/c)2?2. The different role played by the Pauli form factor of the constituents in the transverse and longitudinal channels is illustrated. Our predictions, including an estimate of the theoretical uncertainties, may be checked against the forthcoming results of the experiment E94110 at Jefferson Lab. A positive comparison with the new data may provide compelling evidence that constituent quarks are intermediate substructures between the hadrons and the current quarks and gluons of QCD.

  20. Momentum transfer within a porous medium. I. Theoretical derivation of the momentum balance on the solid skeleton

    NASA Astrophysics Data System (ADS)

    Minale, Mario

    2014-12-01

    The momentum balance on the solid skeleton of a porous medium like porous rocks, foam metals, or porous brushes is, here, theoretically derived with the volume averaging method. It is derived for both homogeneous and non-homogeneous porous media and for the latters no length scales constraints are invoked. The momentum balance on the solid skeleton holds in the whole porous medium and contains volume averaged stresses and velocity. For heterogeneous porous media, it is coupled with the fluid momentum balance through a general averaged quantity, while in the homogeneous case, it is coupled with Darcy's equation, corrected with the first and the second Brinkman's term, through a geometrically rescaled Darcy's term. This latter equation coincides with Biot's equation for poro-elasticity, but it is here derived with a different formalism. This approach gives the opportunity to derive a new stress boundary condition at the interface between a porous medium and a homogeneous fluid.

  1. High momentum transfer R{sub T,L} response functions for {sup 3,4}He.

    SciTech Connect

    Filippone, Bradley; Jones Woodward, Cathleen; Potterveld, David; Day, Donal; Beck, Douglas; Boyd, G.; Dodge, Gail; Sick, Ingo; McCarthy, James; Mougey, Jean; Chen, Jian-Ping; Morgenstern, Joseph; Jourdan, Juerg; Giovanetti, Kevin; Kemper, Kirby; Dennis, Lawrence; Smith, Lee; Chinitz, Leigh; Minehart, Ralph; Milner, Richard; Sealock, Richard; Walker, Richard; McKeown, Robert; Thornton, Stephen; Koh, T.; Lorenzon, Wolfgang; Meziani, Zein-Eddine; Meziani, Zein-Eddine

    1992-07-01

    The tantalizing problem of the 'quenching' of the Coulomb sum rule observed in medium weight nuclei is investigated in light nuclei at high momentum transfer. Inclusive electron scattering cross sections for {sup 3,4}He have been measured in the quasielastic region at electron energies between 0.9 GeV and 4.3 GeV, and scattering angles of 15deg and 85deg. Longitudinal (R{sub L}) and transverse (R{sub T}) response functions have been extracted using a Rosenbluth separation at constant vertical strokeq vectorvertical stroke of 1.050 (GeV/c). The ratio of the longitudinal to the transverse reduced response functions in the negative y region reaches unity. The experimental Coulomb sum rule although with large uncertainty and conversly to the case of medium weight nuclei, saturates at high momentum to the He nucleus total charge namely Z=2. (orig.). INDEX TERMS: coulomb excitation; differential cross sections; electron spectra; electrons; experimental data; gev range 01-10;

  2. Proton electromagnetic form factor ratio at high momentum transfer via recoil polarization in Hall C at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Puckett, Andrew

    2008-10-01

    Experiment E04-108 in Hall C at Jefferson Lab measured the ratio of the proton's electric (GE) and magnetic (GM) form factors using the recoil polarization technique at three different values of squared four-momentum transfer Q^2--5.2, 6.8, and 8.5 GeV^2. Data taking was completed in June 2008, and analysis of the data is underway. Two new detectors were built by the collaboration to carry out this experiment. A large solid-angle electromagnetic calorimeter was used to detect elastically scattered electrons in coincidence with scattered protons detected by the Hall C High Momentum Spectrometer (HMS). The calorimeter allowed a clean rejection of the significant inelastic backgrounds present at such high Q^2. A new Focal Plane Polarimeter (FPP) was installed in the HMS detector hut to measure the polarization of the scattered proton. After a brief overview of the experiment, the present status of the analysis will be discussed.

  3. Changing summer sea ice roughness modifies momentum transfer into the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Martin, Torge; Tsamados, Michel; Feltham, Daniel

    2015-04-01

    The current shrinking of Arctic sea ice affects the transfer of momentum from the atmosphere into the ocean. While in winter a thinner and thus weaker sea ice cover enables a greater ocean surface stress than in previous decades, the enormous retreat of sea ice in recent summers reduced the surface roughness of the Arctic Ocean and hence causes a negative ocean surface stress trend in this season. The latter is related to a generally enhanced surface drag in the presence of sea ice. Martin et al. (2014, JGR) suggested that such amplification of momentum transfer by ice floes peaks at an optimal ice concentration of 80-90% -- since higher concentrations damp momentum transfer due to ice internal stresses. However, this model study only considered a constant sea ice roughness in the calculation of the surface stress. Tsamados et al. (2014, JPO) recently implemented complex variable sea-ice drag coefficients into the sea ice model CICE also distinguishing between skin and form drag. They showed in stand-alone sea ice simulations that varying sea ice roughness due to, amongst others, pressure ridges and floe edges significantly impacts sea ice motion likely with implications for the ocean circulation underneath. Here, we present the effect of variable sea ice drag on the ocean surface stress. A comparison of the CICE results with Martin et al. (2014, JGR) shows that on basin-wide average the ice concentration-ocean stress relationship still peaks at about 80-90% but stress increases more rapidly with increasing ice concentration forming a "plateau" at 40-70%. We find that pressure ridges contribute more to the 80-90% peak whereas floe edges and skin drag shape the plateau. Further, Tsamados et al. (2014, JPO) found for the summer season that floe edges dominate the ice-water drag magnitude and that an increase in the floe edge form drag dominates the overall ice-water drag trend over the past two decades. This hints at the possibility that a favorable floe size distribution associated with loose ice conditions may compensate the negative effect of increased ice-free areas on the basin-wide mean surface drag. To learn more about the consequences on ocean surface stress trends come to this presentation.

  4. The Study of the D(e,e'p)n Reaction at High Four-Momentum Transfer

    NASA Astrophysics Data System (ADS)

    Khanal, Hari

    2014-09-01

    A study of the D (e ,e' p) reaction has been carried out at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) for a set of fixed values of four-momentum transfers Q2 = 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 q-> . 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 angle. A study of the D (e ,e' p) reaction has been carried out at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) for a set of fixed values of four-momentum transfers Q2 = 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 q-> . 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 angle. Department of Energy (DOE).

  5. Structural and optical modification in hafnium oxide thin films related to the momentum parameter transferred by ion beam assistance

    Microsoft Academic Search

    M. Alvisi; S. Scaglione; S. Martelli; A. Rizzo; L. Vasanelli

    1999-01-01

    Hafnium oxide (HfO2) films were deposited on silica and glass substrates by ion (Xe+) assisted deposition with increasing ion momentum transfer to the growing film. The relationship among the ion momentum values, the crystalline phase and the refractive index (packing density) has been worked out by means of X-ray diffraction and spectrophotometric analysis. Compaction of the films by ion beam

  6. 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, Q D * , 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 Q D * , 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%.

  7. 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.

  8. Thruster momentum transfer studies and magnetoplasmadynamic (MPD) thruster use in materials/surface modification

    NASA Astrophysics Data System (ADS)

    Thompson, E.; Collins, W. E.; Burger, A.; George, M. A.; Conner, J. D.

    1995-08-01

    This research project involves the systematic study of the MPD thruster for dual uses. Though it was designed as a thruster for space vehicles, the characteristics of the plasma make it an excellent candidate for industrial applications. This project will seek to characterize the system for use in materials processing and characterization. Crystals grown at Fisk University for use with solid state detectors will be studied. Surface modification on ZnCdTe, CdTe, and ZnTe will be studied using AFM, XPS and SAES. In addition to the surface modification studies, design work on a momentum transfer measurement device has been completed. The design and limitations of the device will be presented.

  9. 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

  10. Thruster momentum transfer studies and magnetoplasmadynamic (MPD) thruster use in materials/surface modification

    NASA Technical Reports Server (NTRS)

    Thompson, E.; Collins, W. E.; Burger, A.; George, M. A.; Conner, J. D.

    1995-01-01

    This research project involves the systematic study of the MPD thruster for dual uses. Though it was designed as a thruster for space vehicles, the characteristics of the plasma make it an excellent candidate for industrial applications. This project will seek to characterize the system for use in materials processing and characterization. Crystals grown at Fisk University for use with solid state detectors will be studied. Surface modification on ZnCdTe, CdTe, and ZnTe will be studied using AFM, XPS and SAES. In addition to the surface modification studies, design work on a momentum transfer measurement device has been completed. The design and limitations of the device will be presented.

  11. A covariant formalism for the N* electroproduction at high momentum transfer

    SciTech Connect

    Gilberto Ramalho,Franz Gross,Maria Haderer De La Pena S,Kazuo Tsushima

    2011-05-01

    A constituent quark model based on the spectator formalism is applied to the gamma N -> N* transition for the three cases, where N* is the nucleon, the Delta and the Roper resonance. The model is covariant, and therefore can be used for the predictions at higher four-momentum transfer squared, Q2. The baryons are described as an off-mass-shell quark and a spectator on-mass-shell diquark systems. The quark electromagnetic current is described by quark form factors, which have a form inspired by the vector meson dominance. The valence quark contributions of the model are calibrated by lattice QCD simulations and experimental data. Contributions of the meson cloud to the inelastic processes are explicitly included.

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

    Microsoft Academic Search

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

    2010-01-01

    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 high-throughput, on-demand, coordinated data transfers over wide-area networks. Our

  13. Estimation of heat and momentum fluxes over complex terrain using a large aperture scintillometer

    Microsoft Academic Search

    A. Chehbouni; C. Watts; J.-P. Lagouarde; Y. H. Kerr; J.-C. Rodriguez; J.-M. Bonnefond; F. Santiago; G. Dedieu; D. C. Goodrich; C. Unkrich

    2000-01-01

    A comprehensive experimental plan has been designed to further investigate the potential and the limitations associated with the use of a large aperture scintillometer (LAS) to infer path average sensible and momentum fluxes over complex surfaces as part of the Semi-Arid Land–Surface–Atmosphere (SALSA) Program. The complexity of the terrain is associated with the type and the cover of the vegetation

  14. The neoclassical angular momentum flux in the large aspect ratio limit

    SciTech Connect

    Wong, S.K.; Chan, V.S. [General Atomics, P.O. Box 85608, San Diego, California 92186-5688 (United States)

    2005-09-15

    The small rotation version of the neoclassical angular momentum flux is calculated in the large aspect ratio limit and in the banana regime. The method relies on solving an adjoint equation to the customary linearized drift kinetic equation, circumventing the difficulty of obtaining the ion distribution function that is second order in the ratio of poloidal gyroradius over plasma scale length. The result differs significantly from a long-standing result for circular cross-section flux surfaces.

  15. Angular momentum transfer to a Milky Way disc at high redshift

    NASA Astrophysics Data System (ADS)

    Tillson, H.; Devriendt, J.; Slyz, A.; Miller, L.; Pichon, C.

    2015-06-01

    An Adaptive Mesh Refinement cosmological resimulation is analysed in order to test whether filamentary flows of cold gas are responsible for the build-up of angular momentum within a Milky Way-like disc at z ? 3. A set of algorithms is presented that takes advantage of the high spatial resolution of the simulation (12 pc) to identify: (i) the central gas disc and its plane of orientation; (ii) the complex individual filament trajectories that connect to the disc; and (iii) the infalling satellites. The results show that two filaments at z ? 5.5, which later merge to form a single filament at z ? 4, drive the angular momentum and mass budget of the disc throughout its evolution, whereas luminous satellite mergers make negligible fractional contributions. Combined with the ubiquitous presence of such filaments in all large-scale cosmological simulations that include hydrodynamics, we argue that these findings provide strong quantitative evidence that the growth of a large fraction of the thin discs in haloes with masses below 1012 M?, which host the vast majority of galaxies, is supported via inflowing streams of cold gas at intermediate and high redshifts.

  16. Measurement of the Nuclear Dependence and Momentum Transfer Dependence of Quasielastic (electron, Electron'proton) Scattering at Large Momentum Transfer.

    NASA Astrophysics Data System (ADS)

    Makins, Naomi C. R.

    Experiment NE18, performed at SLAC, has measured the coincidence quasielastic cross-section for (e,e'p) scattering from Q^2 of 1 to 6.8 (GeV/c)^2. This extends the existing Q^2 range of such measurements by over an order of magnitude. Five targets were used: ^1H, ^2H, ^{12}C, ^{56 }Fe, and ^{197}Au. To test our understanding of quasielastic scattering, the data were compared with a Monte Carlo calculation of the experiment based on a conventional nuclear physics picture. This calculation included radiative effects, using a prescription based on the work of Mo and Tsai and recalculated in a coincidence framework. The elastic hydrogen data were found to be well explained by standard parametrizations of the proton form factor. Spectral functions were extracted from the nuclear data and found to be in good agreement with the Plane Wave Impulse Approximation (PWIA), the deForest offshell electron -proton cross section sigma_{ rm cc1}, and Independent Particle Shell Model spectral functions based on measurements made at Q^2 ~ 0.2 (GeV/c)^2. The nuclear transparency was extracted from the data, and examined for evidence of colour transparency. This phenomenon, motivated by perturbative QCD considerations, is predicted to cause a rise of the transparency with Q^2. No evidence of such a rise was observed in the data. Also, the A-dependence of the transparency was found to be well parametrized by a classical model of transmission through the nucleus. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.).

  17. Energy and angular momentum transfer in the excitation of electron-hole pairs by slow dimers R. Diez Muin~o

    E-print Network

    Muiño, Ricardo Díez

    Energy and angular momentum transfer in the excitation of electron-hole pairs by slow dimers R. Di and angular momentum through electron-hole pair excitations for a slow dimer in an electron gas. We show approximation. We obtain the low-energy limit of the friction coeffi- cient and average angular momentum

  18. 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)$^{2}$.

  19. Coherent Control of Angular Momentum Transfer in Resonant Two-Photon Light-Matter Interaction

    SciTech Connect

    Malik, D. A.; 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)

    2010-04-02

    We show experimentally and theoretically that a polarization-shaped femtosecond laser pulse with a zero net angular momentum creates a net angular momentum in atomic rubidium during resonant two-photon excitation. The necessary conditions for the creation of a nonzero angular momentum as well as the excitation efficiencies are analyzed in the framework of second-order time-dependent perturbation theory.

  20. 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

    Microsoft Academic Search

    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; S. Sirca; A. Sindile; T. Smith; M. Steadman; B. Tonguc; C. Tschalaer; E. Tsentalovich; W. Turchinetz; Y. Xiao; W. Xu; C. Zhang; Z. Zhou; T. Zwart

    2008-01-01

    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

  1. X-ray scattering with momentum transfer in the plane of membrane. Application to gramicidin organization.

    PubMed Central

    He, K; Ludtke, S J; Wu, Y; Huang, H W

    1993-01-01

    We demonstrate a technique for measuring x-ray (or neutron) scattering with the momentum transfer confined in the plane of membrane, for the purpose of studying lateral organization of proteins and peptides in membrane. Unlike freeze-fracture electron microscopy or atomic force microscopy which requires the membrane to be frozen or fixed, in-plane x-ray scattering can be performed with the membrane maintained in the liquid crystalline state. As an example, the controversial question of whether gramicidin forms aggregates in membrane was investigated. We used dilauroylphosphatidylcholine (DLPC) bilayers containing gramicidin in the molar ratio of 10:1. Very clear scattering curves reflecting gramicidin channel-channel correlation were obtained, even for the sample containing no heavy atoms. Thallium ions bound to gramicidin channels merely increase the magnitude of the scattering curve. Analysis of the data shows that the channels were randomly distributed in the membrane, similar to a computer simulation of freely moving disks in a plane. We suggest that oriented proteins may provide substantial x-ray contrast against the lipid background without requiring heavy-atom labeling. This should open up many possible new experiments. PMID:7679294

  2. Role of momentum transfer in the quenching of Gamow-Teller strength

    E-print Network

    Marketin, T; Paar, N; Vretenar, D

    2012-01-01

    The relativistic proton-neutron quasiparticle random phase approximation (pn-RQRPA) is applied in the calculation of the L=0 strength in charge-exchange reactions on $^{48}$Ca, $^{90}$Zr, $^{208}$Pb and nuclei in the Sn isotopic chain. The microscopic theoretical framework is based on the relativistic Hartree-Bogoliubov (RHB) model for the nuclear ground state. The calculation is fully self-consistent, i.e. the same interaction is used both in the RHB equations that determine the quasiparticle basis, and in the matrix equations of the pn-RQRPA. The inclusion of the higher-order terms that include the effect of finite momentum transfer, primarily the isovector spin monopole (IVSM) term, in the transition operator shifts a portion of the strength to the high-energy region above the Gamow-Teller (GT) resonance. The total strength is slightly enhanced in nuclei with small neutron-to-proton ratio but remains unchanged with increasing neutron excess. Based on the strength obtained using the full L=0 transition oper...

  3. Role of momentum transfer in the quenching of Gamow-Teller strength

    E-print Network

    T. Marketin; G. Martínez-Pinedo; N. Paar; D. Vretenar

    2012-03-16

    The relativistic proton-neutron quasiparticle random phase approximation (pn-RQRPA) is applied in the calculation of the L=0 strength in charge-exchange reactions on $^{48}$Ca, $^{90}$Zr, $^{208}$Pb and nuclei in the Sn isotopic chain. The microscopic theoretical framework is based on the relativistic Hartree-Bogoliubov (RHB) model for the nuclear ground state. The calculation is fully self-consistent, i.e. the same interaction is used both in the RHB equations that determine the quasiparticle basis, and in the matrix equations of the pn-RQRPA. The inclusion of the higher-order terms that include the effect of finite momentum transfer, primarily the isovector spin monopole (IVSM) term, in the transition operator shifts a portion of the strength to the high-energy region above the Gamow-Teller (GT) resonance. The total strength is slightly enhanced in nuclei with small neutron-to-proton ratio but remains unchanged with increasing neutron excess. Based on the strength obtained using the full L=0 transition operator in the pn-RQRPA calculation, we have estimated the impact of the IVSM on the strength measured in the charge-exchagne reactions on $^{90}$Zr and found that the data are consistent with the Ikeda sum rule.

  4. Hadronic production of W and Z bosons at large transverse momentum

    NASA Astrophysics Data System (ADS)

    Berger, Edmond L.; Gao, Jun; Kang, Zhong-Bo; Qiu, Jian-Wei; Zhang, Hao

    2015-06-01

    We introduce a modified factorization formalism in quantum chromodynamics for hadronic production of W and Z bosons at large transverse momentum pT. When pT is much larger than the invariant mass Q of the vector boson, this new factorization formalism systematically resums the large fragmentation logarithms, ?smlnm(pT2/Q2) , to all orders in the strong coupling ?s. Using our modified factorization formalism, we present the next-to-leading-order (NLO) predictions for W and Z boson production at high pT at the CERN Large Hadron Collider and at a future 100 TeV proton-proton collider. Our NLO results are about 5% larger in normalization, and they show improved convergence and moderate reduction of the scale variation compared to the NLO predictions derived in a conventional fixed-order perturbative expansion.

  5. Production of CP-Odd Higgs Bosons with Large Transverse Momentum at Hadron Supercolliders

    E-print Network

    Chung Kao

    1994-04-05

    A two Higgs doublet model is employed to study the production of a CP-odd Higgs boson ($A$) associated with a large transverse momentum jet ($j$) at hadron supercolliders. The cross section of $pp \\to jA+X$ is evaluated with four subprocesses: $gg \\to gA$, $gq \\to qA$, $g\\bar{q} \\to \\bar{q}A$ and $q\\bar{q} \\to gA$. We find that $pp \\to jA+X$ is a significant source of CP-odd Higgs bosons at future hadron supercolliders.

  6. 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.

  7. 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.

  8. Optimal orbit transfer suitable for large flexible structures

    NASA Technical Reports Server (NTRS)

    Chatterjee, Alok K.

    1989-01-01

    The problem of continuous low-thrust planar orbit transfer of large flexible structures is formulated as an optimal control problem with terminal state constraints. The dynamics of the spacecraft motion are treated as a point-mass central force field problem; the thrust-acceleration magnitude is treated as an additional state variable; and the rate of change of thrust-acceleration is treated as a control variable. To ensure smooth transfer, essential for flexible structures, an additional quadratic term is appended to the time cost functional. This term penalizes any abrupt change in acceleration. Numerical results are presented for the special case of a planar transfer.

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

    SciTech Connect

    Ramakrishnan, Lavanya [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Guok, Chin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jackson, Keith [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kissel, Ezra [Univ. of Delaware, Newark, DE (United States); Swany, D. Martin [Univ. of Delaware, Newark, DE (United States); Agarwal, Deborah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    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.

  10. Estimation of the ion toroidal rotation source due to momentum transfer from Lower Hybrid waves in Alcator C-Mod

    NASA Astrophysics Data System (ADS)

    Lee, J. P.; Wright, J. C.; Bonoli, P. T.; Parker, R. R.; Catto, P. J.; Podpaly, Y. A.; Rice, J. E.; Reinke, M. L.

    2011-12-01

    Significant ion toroidal rotation ( 50km/s) has been measured by X-Ray spectroscopy for impurities in Alcator C-Mod during lower hybrid (LH) RF power injection [1]. We investigate the relation between the computed toroidal momentum input from LH waves and the measured INITIAL change of ion toroidal rotation when the LH power is turned on. The relation may depend on the plasma current and magnetic configuration [2, 3]. Because of the fast build up time of the electron quasilinear plateau (<1 millisecond), the electron distribution function rapidly reaches steady state in which the electrons transfer momentum to the ions. The LH wave momentum input is computed from the self consistent steady state electron distribution function and a bounce-averaged quasilinear diffusion coefficient that are obtained by iterating a full wave code (TORLH) with a Fokker Plank code (CQL3D)

  11. Study of mass and momentum transfer and their effect on the direct fluorination of uranium oxide

    SciTech Connect

    Cross, P.E.

    1983-02-25

    The mechanism for the fluorination of solid U/sub 3/O/sub 8/ to gaseous UF/sub 6/ was found to be a two-step process with solid UO/sub 2/F/sub 2/ as an intermediate. The highest particle temperatures were found to be associated with the initial reaction step to UO/sub 2/F/sub 2/; it was recommended that these temperatures be maintained below 1700/sup 0/F. The chemical equilibrium constant for the fluorination of PuF/sub 4/ to PuF/sub 6/ was found to be unexpectedly low at typical flame tower temperatures. Although not confirmed, there is an indication in the literature that a similar equilibrium constant is associated with the fluorination of NpF/sub 4/ and other transuranic molecules. It was recommended that uranium oxides which are significantly contaminated with transuranics should not be processed through a direct fluorination reactor such as the UF/sub 6/ flame tower. Reaction rate equations were developed for the fluorination of U/sub 3/O/sub 8/, UF/sub 4/, PuF/sub 4/ and NpF/sub 4/. During the course of the development, a significant discrepancy was found in the literature for the activation energy of the fluorination of U/sub 3/O/sub 8/. Equations were developed for both a high and low limit rate constant for the fluorination of U/sub 3/O/sub 8/. A variey of momentum, heat and mass transfer equations were developed for both oxide particles and the gas phase within the flame tower. Equations were developed to estimate the physical and transport properties of each gaseous component and the gas mixture as a whole. These properties and the transport equations were used to estimate the reaction time and distance for oxide particles with both the low and high limit reaction rate constant. The procedures used to perform these calculations is limited to constant temperature and an oxide feed comprised of a single particle size. The results indicate that above 1000/sup 0/F the mass transfer of reactants and products becomes increasingly important to the overall rate of the reaction.

  12. Observation of Orbital Angular Momentum Transfer from Bessel-Shaped Acoustic Vortices to Diphasic Liquid-Microparticle Mixtures.

    PubMed

    Hong, ZhenYu; Zhang, Jie; Drinkwater, Bruce W

    2015-05-29

    We observe distinct regimes of orbital angular momentum (OAM) transfer from two-dimensional Bessel-shaped acoustic vortices to matter. In a homogeneous diphasic mixture of microparticles and water, slow swirling about the vortex axis is seen. This effect is driven by the absorption of OAM across the mixture, the motion following the OAM density distribution. Larger particles are formed into clusters by the acoustic radiation force, making the mixture nonhomogeneous. Here, the OAM transfer to the microparticle clusters dominates and they spin at high speeds entraining the surrounding fluid. PMID:26066437

  13. Study of the Momentum Transfer to Target-Like Residues in Heavy Ion Reactions by Prompt Gamma Measurements

    NASA Astrophysics Data System (ADS)

    Korir, K. A.; Connell, S. H.; Sellschop, J. P. F.; Sideras-Haddad, E.; Förtsch, S. V.; Lawrie, J. J.; Newman, R. T.; Mabala, G. K.; Smit, F. D.; Steyn, G. F.; Bassini, R.; Birattari, C.; Cavinato, M.; Fabrici, E.; Gadioli, E.; Gadioli Erba, E.; Vilakazi, Z.; Becker, B.

    2001-09-01

    Doppler shift and Doppler broadening of prompt ? lines have been measured for many reaction residues in the interaction of 12C with 63Cu at 33 A MeV incident 12C energy using the AFRODITE detector array at NAC, Faure, Cape Town. A preliminary analysis of these data, which carry information of the momentum transferred in the reaction, shows that very useful information regarding reaction mechanisms can be obtained by this technique.

  14. Contribution of meson-exchange currents to the electromagnetic structure of the deuteron at high momentum transfers

    SciTech Connect

    Krutov, A. F., E-mail: krutov@ssu.samara.r [Samara State University (Russian Federation); Troitsky, V. E., E-mail: troitsky@theory.sinp.msu.s [Moscow State University, Institute of Nuclear Physics (Russian Federation); Tsirova, N. A., E-mail: ntsirova@ssu.samara.r [Samara State University (Russian Federation)

    2009-01-15

    The leading term of the asymptotic expansion of the contributions of the {pi}NN and {rho}{pi}{gamma} processes to the electromagnetic form factors of the deuteron at high momentum transfers is calculated. The resulting asymptotic behavior is compared with experimental data obtained at the Thomas Jefferson Laboratory. Constraints on the functional dependence of meson-nucleon vertex functions that ensure a correct asymptotic behavior of deuteron form factors are discussed.

  15. Measurements of the Proton Elastic-Form-Factor Ratio mupGEp\\/GMp at Low Momentum Transfer

    Microsoft Academic Search

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

    2007-01-01

    High-precision measurements of the proton elastic form-factor ratio, mupGEp\\/GMp, have been made at four-momentum transfer, Q2, values between 0.2 and 0.5GeV2. 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,

  16. Proton electromagnetic form factor ratio at high momentum transfer via recoil polarization in Hall C at Jefferson Lab

    Microsoft Academic Search

    Andrew Puckett

    2008-01-01

    Experiment E04-108 in Hall C at Jefferson Lab measured the ratio of the proton's electric (GE) and magnetic (GM) form factors using the recoil polarization technique at three different values of squared four-momentum transfer Q^2--5.2, 6.8, and 8.5 GeV^2. Data taking was completed in June 2008, and analysis of the data is underway. Two new detectors were built by the

  17. Features of turbulent momentum and heat transfer in a stably stratified boundary layer over a rough surface

    Microsoft Academic Search

    A. F. Kurbatskiy; L. I. Kurbatskaya

    2008-01-01

    The features of the structure of a stable boundary layer over an urbanized surface are studied using a nonlocal model for\\u000a the turbulent momentum and heat fluxes, which physically adequately takes into account the effect of buoyancy on turbulent\\u000a transfer. The transformation of the structure of the boundary layer during transition from a state of convective mixing to\\u000a a stable

  18. Large Cash Transfers to the Elderly in South Africa

    Microsoft Academic Search

    Anne Case; Angus Deaton

    1998-01-01

    The authors examine the social pension in South Africa, where large cash sums--about twice the median per capita income of African bouseholds--are paid to people qualified by age but irrespective of previous contributions. They present the history of the scheme and use a 1993 nationally representative survey to investigate the redistributive consequences of the transfers, documenting who receive the pensions,

  19. Large-transverse-momentum processes: the ISR as a gluon collider

    E-print Network

    Pierre Darriulat

    2012-06-19

    It is argued that, contrary to what is often said, large-transverse-momentum hadronic processes studied at the ISR have made a significant contribution to the understanding of the strong interaction and, in particular, to the development of quantum chromodynamics. In their unique role as a gluon collider the ISR have provided information that no other accelerator could have directly offered. They allowed one to probe high values of the centre-of-mass energy that were not available to fixed-target experiments. The latter, however, were more flexible and, together, they allowed for powerful explorations of the hadron structure and of the relevant dynamics in sectors such as inclusive particle production, direct photon production, and jet structure studies. It remains true that, rightly so, the ISR will be mostly remembered as the founders of a lineage that includes the proton-antiproton colliders and, today, the LHC.

  20. 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.

  1. Subcooled nucleate boiling heat transfer from a large diameter tube

    SciTech Connect

    Brown, M.J. [Atomic Energy of Canada Limited, Whiteshell, Manitoba (Canada). Whiteshell Labs.; Fung, K.K. [Ontario Hydro Nuclear, Toronto, Ontario (Canada); Byrne, T.P. [Ontario Hydro Technologies, Toronto, Ontario (Canada)

    1996-12-31

    Nucleate boiling heat transfer from the outside of large-diameter tubes has not been well studied. There are many large-diameter horizontal tubes in the core of a CANDU{reg_sign} nuclear reactor, and it is important to quantify the different modes of heat transfer from the tubes (known as calandria tubes) to the heavy water moderator. This paper describes a series of experiments performed to study nucleate boiling heat transfer from the outside surface of a horizontal calandria tube to subcooled and pressurized light water. When the circulating pump was on, it caused an upflow of water in the vicinity of the tube, estimated to be an average of 0.3 m/s. The flow cooled the tube and increased the surface temperature fluctuations, in contrast to the relatively steady temperatures observed by Dowlati and Byrne (1995) in a test section of similar diameter, but made from a solid copper block. The cooling effect of the pumped flow was the greatest for high subcooling, low heat flux and high pressure. The magnitudes of these fluctuations are explained in terms of transient heat conduction when the surface alternates between nucleation and cooling by the cold liquid. The heat transfer from the bottom of the tube was modelled by a combination of pool boiling, global single-phase natural convection and stagnation-point single-phase forced-convection correlations. The experiments showed that Rohsenow`s pool boiling correlation (with a single-phase free convection component) successfully modelled the outer surface temperatures on the large-diameter horizontal tube when the circulating pump was off. Even at high water subcooling (60 C) and low heat flux (200 kW/m{sup 2}), nucleate boiling dominated the heat transfer.

  2. Application of Momentum Transfer Theory for Ion and Electron Transport in Pure Gases and in Gas Mixtures

    NASA Astrophysics Data System (ADS)

    Jovanovi?, J. V.; Vrhovac, S. B.

    2004-12-01

    In this paper we have presented two applications of Momentum Transfer Theory (MTT), which were both aimed at obtaining reliable data for modeling of non-equilibrium plasma. Transport properties of ion swarms in presence of Resonant Charge Transfer (RCT) collisions are studied using Momentum Transfer Theory (MTT). Using the developed MTT we tested a previously available anisotropic set of cross-sections for Ar++Ar collisions bay making the comparisons with the available data for the transverse diffusion coefficient. We also developed an anisotropic set of Ne++Ne integral cross-sections based on the available data for mobility, longitudinal and transverse diffusion. Anisotropic sets of cross-sections are needed for Monte Carlo simulations of ion transport and plasma models. Application of Blanc's Law for drift velocities of electrons and ions in gas mixtures at arbitrary reduced electric field strenghts E/n0 was studied theoretically and by numerical examples. Corrections for Blanc's Law that include effects of inelastic collisions were derived. In addition we have derived the common mean energy procedure that was proposed by Chiflikian in a general case both for ions and electrons. Both corrected common E/n0 and common mean energy procedures provide excellent results even for electrons at moderate E/n0 where application of Blanc's Law was regarded as impossible. In mixtures of two gases that have negative differential conductivity (NDC) even when neither of the two pure gases show NDC the Blanc's Law procedure was able to give excellent predictions.

  3. Instationary momentum and mass transfer at accelerated motion of single particles

    Microsoft Academic Search

    L. Hilprecht

    1976-01-01

    Unsteady flow and heat and mass transfer were calculated and interpreted in the light of accelerated movement of a rigid individual particle moving under gravity. For the purposes of the calculation, the complete transport equations were solved numerically. Both the instationary movement of the particle and the flow as well as the heat and mass transfer in the vicinity of

  4. CFD MODELING OF ITER CABLE-IN-CONDUIT SUPERCONDUCTORS. PART V: COMBINED MOMENTUM AND HEAT TRANSFER IN RIB ROUGHENED PIPES

    SciTech Connect

    Zanino, R.; Giors, S. [Dipartimento di Energetica, Politecnico Torino, I-10129 (Italy)

    2008-03-16

    Computational Fluid Dynamics (CFD) techniques have been proposed and applied in a series of papers to analyze cable-in-conduit conductors (CICC) for the International Thermonuclear Experimental Reactor (ITER). Previous work on the pressure drop in the central channel of ITER CICC is extended here to the problem of combined heat and momentum transfer. The CFD model, solved by the FLUENT commercial code, is first validated against 2D and 3D data from compact heat exchangers, showing good agreement. The Colburn analogy between the friction factor f and the Nusselt number Nu is not verified in the considered 2D geometries, as shown by both experiment and simulation. The validated CFD model is finally applied to the 3D analysis of central channel-like geometries relevant for ITER CICC. It is shown that the heat transfer coefficient on the central channel side stays relatively close to the smooth-pipe (Dittus-Boelter) value.

  5. Angular momentum transport and large eddy simulations in magnetorotational turbulence: the small Pm limit

    NASA Astrophysics Data System (ADS)

    Meheut, Heloise; Fromang, Sébastien; Lesur, Geoffroy; Joos, Marc; Longaretti, Pierre-Yves

    2015-07-01

    Context. Angular momentum transport in accretion discs is often believed to be due to magnetohydrodynamic turbulence mediated by the magnetorotational instability (MRI). Despite an abundant literature on the MRI, the parameters governing the saturation amplitude of the turbulence are poorly understood and the existence of an asymptotic behaviour in the Ohmic diffusion regime has not been clearly established. Aims: We investigate the properties of the turbulent state in the small magnetic Prandtl number limit. Since this is extremely computationally expensive, we also study the relevance and range of applicability of the most common subgrid scale models for this problem. Methods: Unstratified shearing box simulations are performed both in the compressible and incompressible limits, with a resolution up to 800 cells per disc scale height. This is the highest resolution ever attained for a simulation of MRI turbulence. Different magnetic field geometry and a wide range of dimensionless dissipative coefficients are considered. We also systematically investigate the relevance of using large eddy simulations (LES) in place of direct numerical simulations. Results: In the presence of a mean magnetic field threading the domain, angular momentum transport converges to a finite value in the small Pm limit. When the mean vertical field amplitude is such that ? (the ratio between the thermal and magnetic pressure) equals 103, we find ? ~ 3.2 × 10-2 when Pm approaches zero. In the case of a mean toroidal field for which ? = 100, we find ? ~ 1.8 × 10-2 in the same limit. Implicit LES and the Chollet-Lesieur closure model both reproduce these results for the ? parameter and the power spectra. A reduction in computational cost by a factor of at least 16 (and up to 256) is achieved when using such methods. Conclusions: MRI turbulence operates efficiently in the small Pm limit provided there is a mean magnetic field. Implicit LES offers a practical and efficient means of investigation of this regime but should be used with care, particularly in the case of a vertical field. The Chollet-Lesieur closure model is perfectly suited for simulations done with a spectral code.

  6. Momentum transfer theory of ion transport under the influence of resonant charge transfer collisions: the case of argon and neon ions in parent gases

    NASA Astrophysics Data System (ADS)

    Jovanovi?, J. V.; Vrhovac, S. B.; Petrovi?, Z. Lj.

    2002-12-01

    Transport properties of ion swarms in presence of Resonant Charge Transfer (RCT) collisions are studied using Momentum Transfer Theory (MTT). It was shown that, not surprisingly, RCT collisions may be represented as a special case of elastic scattering. Using the developed MTT we tested a previously available anisotropic set of cross-sections for Ar+Ar^+ collisions by making the comparisons with the available data for the transverse diffusion coefficient. We also developed an anisotropic set of Ne+Ne^+ integral cross-sections based on the available data for mobility, longitudinal and transverse diffusion. Anisotropic sets of cross-sections are needed for Monte Carlo simulations of ion transport and plasma models.

  7. 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.

  8. RADIAL ANGULAR MOMENTUM TRANSFER AND MAGNETIC BARRIER FOR SHORT-TYPE GAMMA-RAY-BURST CENTRAL ENGINE ACTIVITY

    SciTech Connect

    Liu Tong; Gu Weimin; Hou Shujin [Department of Physics and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China); Liang Enwei [Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences, Guangxi University, Nanning, Guangxi 530004 (China); Lei Weihua [School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Lin Lin; Zhang Shuangnan [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Dai Zigao, E-mail: lew@gxu.edu.cn [Department of Astronomy, Nanjing University, Nanjing, Jiangsu 210093 (China)

    2012-11-20

    Soft extended emission (EE) following initial hard spikes up to 100 s was observed with Swift/BAT for about half of known short-type gamma-ray bursts (SGRBs). This challenges the conversional central engine models of SGRBs, i.e., compact star merger models. In the framework of black-hole-neutron-star merger models, we study the roles of radial angular momentum transfer in the disk and the magnetic barrier around the black hole in the activity of SGRB central engines. We show that radial angular momentum transfer may significantly prolong the lifetime of the accretion process, which may be divided into multiple episodes by the magnetic barrier. Our numerical calculations based on models of neutrino-dominated accretion flows suggest that disk mass is critical for producing the observed EE. In the case of the mass being {approx}0.8 M {sub Sun }, our model can reproduce the observed timescale and luminosity of both the main and the EE episodes in a reasonable parameter set. The predicted luminosity of the EE component is lower than the observed EE within about one order of magnitude and the timescale is shorter than 20 s if the disk mass is {approx}0.2 M {sub Sun }. Swift/BAT-like instruments may be not sensitive enough to detect the EE component in this case. We argue that the EE component could be a probe for the merger process and disk formation for compact star mergers.

  9. An experimental study of heat and momentum transfer in pipe flow of viscoelastic fluids

    NASA Astrophysics Data System (ADS)

    Ng, K. S.

    Heat transfer and pressure drop results are presented for pipe flow of aqueous solutions of polyacrylamide and polyethylene oxide in weight concentration of a few thousand parts per million. Experiments were conducted in two experimental set-ups. The first set-up consisted of two different diameter tubes. The turbulent flow hydrodynamic entry length was found to be 110 pipe diameters. Laminar friction factor data were in good agreement with correlations for purely viscous non-Newtonian fluids. The second set-up consisted of three different diameter tubes with heat transfer length-to-diameter ratio of 282, 489, and 648. The turbulent flow thermal entry length was found to be about 400 pipe diameters. The asymptotic dimensionless heat transfer coefficients were observed to be independent of pipe diameter, polymer molecular weight, and polymer concentration, suggesting the existence of a maximum heat transfer reduction asymptote.

  10. Mass Transfer Velocity and Momentum Vertical Exchange in Simulated Deep Street Canyons

    NASA Astrophysics Data System (ADS)

    Murena, F.; di Benedetto, A.; D'Onofrio, M.; Vitiello, G.

    2011-07-01

    A box model to simulate mass transfer inside deep street canyons and with atmospheric flow above is introduced and discussed. Two ideal deep street canyons with aspect ratios of 3 and 5 (the aspect ratio being the ratio between building height and street width H/ W) are considered. This range of aspect ratios, found in many densely populated historical centres in Mediterranean cities as well as in other cities around the world, potentially creates high air pollutant concentration levels. Our model is based on a combination of analytical solutions and computation fluid dynamics (CFD) simulations using carbon monoxide (CO) as a tracer pollutant. The analytical part of the model is based on mass transfer velocity concepts while CFD simulations are used both for a preliminary validation of the physical hypothesis underlying the model (steady-state simulations) and to evaluate the concentration pattern with time (transient or wash-out simulations). Wash-out simulation curves were fitted by model curves, and mass transfer velocities were evaluated through a best-fitting procedure. Upon introducing into the model the contribution of traffic-produced turbulence, the modelled CO concentration levels became comparable with those obtained in real-world monitoring campaigns. The mass transfer rate between the canyon and the above atmosphere was then expressed in terms of an overall mass transfer velocity, which directly allows the evaluation of the mass transfer rate between the bottom volume of the canyon (pedestrian level) with the above atmosphere. Overall mass transfer velocities are reported as a function of the operating conditions studied ( H/ W = 3-5 and wind speeds = 2-8 ms-1). Finally, a simple expression is reported for determining pollutant concentrations at the pedestrian level based on the overall mass transfer velocity defined.

  11. 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. Berger1996; 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 thermagnonicmethod, 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).

  12. 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.

  13. Angular momentum transfer and rotational effects in planetary magnetotails and polar caps

    NASA Astrophysics Data System (ADS)

    Vasyliunas, Vytenis M.

    2013-04-01

    In magnetospheres of rapidly rotating planets (e.g., Jupiter, Saturn), significant effects of planetary rotation are possible both within the polar cap (here taken to be the region of the ionosphere where the magnetic field lines extend into the lobes of the magnetotail) and within the magnetotail itself. Corotation of the neutral atmosphere at ionospheric altitudes tends to drag the plasma (by collisions); the resulting plasma motion deforms the magnetic field, producing currents that flow horizontally in the ionosphere and connect to vertical, predominantly Birkeland (magnetic-field-aligned) currents - in one direction over most of the polar cap, and in the opposite direction at its boundaries, closing somewhere in the outer magnetosphere/magnetotail/magnetosheath. The J × B force in the ionosphere implies a torque both on the neutral atmosphere (tending to slow down its corotation) and on magnetic flux tubes emanating from the polar cap. The net result is tranfer of angular momentum from the corotating neutral atmosphere upward along the magnetic field lines; above the ionosphere, the angular momentum flux density is essentially the Maxwell stress tensor ×r. One possible result is to twist the field lines of the magnetotail; this has been modeled mostly by analogy to the Parker spiral in the solar wind, which is questionable because the ratio magnetic/plasma energy density in the magnetotail is drastically different from that in the solar wind. An aspect that so far does not seem to have received any attention is that, because magnetic field lines turn from nearly vertical at the polar cap to nearly solar-wind-aligned in the magnetotail, the angular momentum must correspondingly turn by ~ 90°; this requires appropriate torques, which can be shown to imply significant (mainly dawn-dusk) asymmetries in either the configuration of the magnetotail, the distribution of currents and disturbance fields in the polar cap, or both.

  14. Charge transfer and momentum exchange in exospheric D-H(+) and H-D(+) collisions

    NASA Technical Reports Server (NTRS)

    Hodges, R. R., Jr.; Breig, E. L.

    1993-01-01

    Mechanisms that control the escape of deuterium from planetary exospheres include the acceleration of D(+) in the polar wind, and the production of suprathermal D atoms through nonthermal collisions. In this paper we examine the effects of neutral-ion interactions involving deuterium and hydrogen on the velocity distribution of neutral D. A two-center scattering approximation is used as the basis for calculations of the differential cross sections for charge transfer and elastic scatter in collision of H with D(+) and of D with H(+) for ionosphere-exosphere collision energies below 10 e V. These data are used to derive temperature dependent rate coefficients for the charge transfer branches of these interactions, and to determine the effects of ion-neutral temperature differences on the rate of generation of suprathermal D through charge transfer and elastic scatter.

  15. Understanding the Role of Interannual Variability and Momentum Transfer on Wind Energy

    NASA Astrophysics Data System (ADS)

    Koerner, S.; Brunsell, N. A.; Miller, L.; Mechem, D. B.

    2014-12-01

    Forecasting realistic wind power potential is essential for wind energy to assist with meeting future energy demands. Current wind power estimates rely on the use of mean climatological wind speeds. This approach to estimating wind power neglects the influence of momentum extraction by the turbines (i.e. turbine-turbine interactions) and interannual variability in windspeed. The present study will use a wind turbine parameterization within the Weather and Research Forecasting (WRF) model to assess the role of interannual and climatic variability on power extraction. The WRF model will be forced by NARR, and run from 1980-2010 to incorporate different climatic conditions over the central United States. Analysis focusses on the role of climate variability on wind power extraction; specifically on the role of drought and wet periods, as well as variability in the Great Plains Low Level Jet. In addition, WRF will be used to assess the impact of wind turbines on each term of the momentum budget. Understanding the impact of interannual variability will improve our understanding of the role that wind power can play in meeting future energy demands.

  16. Momentum transfer driven textural changes of CeO2 thin films

    NASA Astrophysics Data System (ADS)

    Van Steenberge, S.; Leroy, W. P.; Hubin, A.; Depla, D.

    2014-09-01

    The influence of the target erosion depth on the film texture was investigated during DC reactive magnetron sputter deposition of CeO2 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.

  17. Momentum transfer in laser-induced ablation of hard tissue measured by laser Doppler vibrometry

    NASA Astrophysics Data System (ADS)

    Foth, Hans-Jochen; Barton, Thomas G.; Meyer, Dirk H.; Postel, Adriaen

    1998-07-01

    A laser Doppler vibrometer was used in a pendulum experiment to measure the recoil momentum induced in hard tissue by pulsed infrared laser exposure. A Holmium:YAG laser was irradiated at bone and a superpulsed CO2 laser irradiated at dentin. Since the masses of the samples were known and the ablated masses were measured, this method allowed an indirect determination of the velocity of the ablated particles. In a second experiment performed with the CO2 laser the velocities of the ablated particles were measured directly by the time of flight detected by the laser beam of the vibrometer. The results of both methods are in good agreement; at a mean power of 0.5 Watt of the CO2 laser the velocity was 50 - 60 m/s increasing at higher mean powers.

  18. Electroproduction of {eta} mesons in the S{sub 11}(1535) resonance region at high momentum transfer

    SciTech Connect

    Dalton, M. M. [University of the Witwatersrand, Johannesburg (South Africa); Adams, G. S.; Moziak, B.; Stoler, P.; Villano, A. [Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Ahmidouch, A.; Danagoulian, S. [North Carolina A and T State University, Greensboro, North Carolina 27411 (United States); Angelescu, T.; Malace, S. [Bucharest University, Bucharest (Romania); Arrington, J.; Hafidi, K.; Holt, R. J.; Reimer, P. E.; Schulte, E.; Zheng, X. [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Asaturyan, R.; Mkrtchyan, H.; Navasardyan, T.; Tadevosyan, V. [Yerevan Physics Institute, Yerevan (Armenia); Baker, O. K. [Hampton University, Hampton, Virginia 23668 (United States); Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)] (and others)

    2009-07-15

    The differential cross section for the process p(e,e{sup '}p){eta} has been measured at Q{sup 2}{approx}5.7 and 7.0(GeV/c){sup 2} for center-of-mass energies from threshold to 1.8 GeV, encompassing the S{sub 11}(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{sub 1/2}, for the production of the S{sub 11}(1535) resonance, is extracted from the data. Within the limited Q{sup 2} now measured, this quantity appears to begin scaling as Q{sup -3}--a predicted, but not definitive, signal of the dominance of perturbative QCD at Q{sup 2}{approx}5 (GeV/c){sup 2}.

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

    E-print Network

    Amaro, J E; Caballero, J A; Donnelly, T W; Maieron, C; Udias, J M

    2009-01-01

    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.

  20. 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.

  1. 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.

  2. 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.

  3. Adaptive attitude control and momentum management for large-angle spacecraft maneuvers

    Microsoft Academic Search

    Alexander G. Parlos; John W. Sunkel

    1992-01-01

    The fully coupled equations of motion are systematically linearized around an equilibrium point of a gravity gradient stabilized spacecraft, controlled by momentum exchange devices. These equations are then used for attitude control system design of an early Space Station Freedom flight configuration, demonstrating the errors caused by the improper approximation of the spacecraft dynamics. A full state feedback controller, incorporating

  4. Production of W's with large transverse momentum at the CERN proton-antiproton collider

    Microsoft Academic Search

    C. Albajar; Michael G Albrow; O. C. Allkofer; Geoffrey T J Arnison; Alan Astbury; Bernard Aubert; T J Axon; Cesare Bacci; Trevor C Bacon; Navjit Bains; J Richard Batley; G. Bauer; S. Beingessner; J. Bellinger; A. Bettini; A. Bezaguet; Kors Bos; E. Buckley; G. Busetto; P. Catz; P. Cennini; Sandro Centro; F. Ceradini; D. G. Charlton; G. Ciapetti; Sergio Cittolin; D. Clarke; D. Cline; Christian Cochet; Jacques Colas; P. Colas; M. Corden; J. A. Coughlan; G. Cox; D. Dau; M. Debeer; J. P. Debrion; M. Degiorgi; Michel Della Negra; M. Demoulin; B. Denby; Daniel Denegri; A. Diciaccio; Ludwik Dobrzynski; Jheroen Dorenbosch; John D Dowell; E. Duchovni; R. Edgecock; Karsten Eggert; Eric F Eisenhandler; Nick Ellis; P. Erhard; Helmut Faissner; I. F. Fensome; Margret Fincke-Keeler; P. Flynn; G. Fontaine; R. Frey; L. Gately; J. Garvey; D. Gee; S. Geer; A. Geiser; C. Ghesquiere; P. Ghez; C C Ghiglino; W. R. Gibson; Y. Giraud-Heraud; Alain Givernaud; A. Gonidec; H. Grassmann; Geoffrey H Grayer; W. Haynes; S. J. Haywood; H. Hoffmann; D. J. Holthuizen; R James Homer; A K Honma; M. Ikeda; Werner Jank; Martin Paul Jimack; Ginette Jorat; Peter I P Kalmus; V. Karimäki; Richard K Keeler; Ian Richard Kenyon; A. Kernan; A. Khan; W. Kienzle; Ritva Kinnunen; Manfred Krammer; J. Kroll; Didier Kryn; P. Kyberd; F. Lacava; J. P. Laugier; J. P. Lees; R. Leuchs; S. Levegrun; S. Li; D. Linglin; E. Locci; K. Long; T W Markiewicz; C. Markou; Manfred Markytan; Guy Maurin; J.-P. Mendiburu; Anna Teresa Meneguzzo; J. P. Merlo; T. Meyer; M.-N. Minard; M. Mohammadi; K. Morgan; M. Moricca; H.-G. Moser; B. Mours; Th. Muller; A. Nandi; Lutz Naumann; P. Nedelec; Alan Robert Norton; G. Pancheri; D. Pascoli; Felicitas Pauss; C. Perault; P. Petta; E. Petrolo; G. Piano Mortari; E. Pietarinen; C. Pigot; M. Pimiä; Alfredo Placci; J.-P. Porte; E. Radermacher; T. Redelberger; H. Reithler; Jean Pierre Charles Revol; J. Richman; D. Robinson; J. Rohlf; P. Rossi; Carlo Rubbia; W. Ruhm; G. Sajot; G. Salvini; Jean Sass; D. Samyn; Aurore Savoy-Navarro; D. Schinzel; A. Schwartz; W. Scott; Christopher J Seez; T. P. Shah; I. Sheer; I. Siotis; D. Smith; Randall J Sobie; J. Strauss; J. Streets; Claudia J Stubenrauch; D J Summers; K. Sumorok; F. Szoncso; Charling Tao; Anton Taurok; I. Ten Have; S. Tether; G. Thompson; E. Tscheslog; Jorma Tuominiemi; B. van Eijk; J. P. Vialle; L. Villasenor; Tejinder S Virdee; H. von der Schmitt; W. von Schlippe; J. Vrana; V. Vuillemin; K. Wacker; H. D. Wahl; P M Watkins; A. Wildish; J. Wilson; I Wingerter-Seez; S. J. Wimpenny; X. Wu; Claudia Elisabeth Wulz; T R Wyatt; Michel Jean Paul Yvert; C. Zaccardelli; I E Zacharov; Nicolas Zaganidis; L. Zanello; P L Zotto

    1987-01-01

    We have measured the W transverse momentum distribution (pTW) using a sample of 323 W --> enu and W --> munu events produced in proton-antiproton collisions at the CERN collider. In the present letter we extend the study of the distribution up to pTW ~- m W and compare to leading and higher order QCD. This comparison is a precise

  5. Plasmid vectors capable of transferring large DNA fragments to yeast.

    PubMed

    Morris, D W; Noti, J D; Osborne, F A; Szalay, A A

    1981-01-01

    We have constructed several cloning vectors which can be used in vitro packaging and yeast transformation. These plasmids have been designed for the convenient cloning of large segments of DNA and their transfer to yeast. They contain bacterial plasmid DNA sequences for replication and selection in Escherichia coli, yeast 2-microns plasmid DNA sequences or chromosomal replicators and yeast markers necessary for replication and selection in yeast, and the cohesive ends of bacteriophage lambda which allow packaging of recombinant molecules into lambda phage heads. Large fragments (22-38 kb) of Klebsiella pneumoniae and Zea mays DNA were ligated into plasmid vector pBTI-1 to make complete genome libraries. One clone from the K. pneumoniae library was amplified in E. coli and the purified DNA used to transform yeast cells. Transformation of yeast by large DNA fragments occurred at high frequencies. The recombinant plasmid was stably maintained in yeast, provided selective pressure for Leu+ transformants was maintained. The structurally complete recombinant plasmid can be recovered from yeast by transforming E. coli to ampicillin resistance. Fewer than 5% of the recovered plasmids had undergone recombination with endogenous yeast 2-microns plasmid. PMID:6299664

  6. Frame-assisted membrane transfer for large area optoelectronic devices on flexible substrates

    Microsoft Academic Search

    Weiquan Yang; Hongjun Yang; Santhad Chuwongin; Jung-Hun Seo; Zhenqiang Ma; Jesper Berggren; Mattias Hammar; Weidong Zhou

    2011-01-01

    Frame assisted membrane transfer process was developed to transfer large area crystalline semiconductor nanomembranes on flexible plastic substrates. InP nanomembranes as large as 2cm×2cm was transferred successfully. Large area flexible photodetectors, solar cells and LED arrays all have been demonstrated experimentally, based on transferred InP nanomembranes. Flexible optoelectronics devices based on single crystal semiconductor nanomembranes (NM), which combine the advantages

  7. Effect of external flow velocity on momentum transfer of dielectric barrier discharge plasma actuators

    NASA Astrophysics Data System (ADS)

    Pereira, Ricardo; Ragni, Daniele; Kotsonis, Marios

    2014-09-01

    An experimental study is performed towards identifying cross-talk effects between DBD plasma actuators and external flow. An actuator is positioned in a boundary layer operated in a range of free stream velocities from 0 to 60 m/s, and tested both in counter-flow and co-flow forcing configurations. Electrical measurements are used for estimating the power consumption and the discharge formation is visualized using a CCD camera. The actuator's force is measured using a sensitive load cell. Results show the power consumption is constant for different flow velocities and actuator configurations. The plasma light emission is constant for co-flow forcing but shows a trend of increasing intensity with counter-flow forcing for increasing free stream velocities. The measured force is constant for free stream velocities larger than 20 m/s, with same magnitude and opposite direction for the counter-flow and co-flow configurations. In quiescent conditions, the measured force is smaller due to the change in wall shear force by the induced wall-jet. An analytical model is presented to estimate the influence of external flow on the actuator force. It is based on conservation of momentum through the ion-neutral collisional process while including the contribution of the wall shear force. Satisfactory agreement is found between the prediction of the model and experimental data at different external flow velocities.

  8. Angular Momentum Transfer in the Binary X-ray Pulsar GX 1+4*

    NASA Astrophysics Data System (ADS)

    Greenhill, J. G.; Galloway, D. K.; Murray, J. R.

    1999-12-01

    Optical and X-ray spectroscopy indicate that the X-ray pulsar GX 1+4 is seen through a cloud of gravitationally bound matter. We discuss an unstable negative feedback mechanism (originally proposed by Kotani et al. 1999), based on X-ray heating of this matter which controls the accretion rate when the source is in a low X-ray luminosity state. A deep minimum lasting ˜6 hours occurred during observations with the RXTE satellite over 1996 July 19-21. The shape of the X-ray pulses changed remarkably from before to after the minimum. These changes may be related to the transition from neutron star spin-down to spin-up which occurred at about the same time. Smoothed particle hydrodynamic simulations of the effect of adding matter with opposite angular momentum to an existing disk, show that it is possible for a number of concentric rings with alternating senses of rotation to co-exist in a disk. This could provide an explanation for the step-like changes in ? which are observed in GX 1+4. Changes at the inner boundary of the disk occur at the same timescale as that imposed at the outer boundary. Reversals of material torque on the neutron star occur at a minimum in L X .

  9. Angular momentum transport and large eddy simulations in magnetorotational turbulence: the small Pm limit

    E-print Network

    Meheut, H; Lesur, G; Joos, M; Longaretti, P -Y

    2015-01-01

    Angular momentum transport in accretion discs is often believed to be due to magnetohydrodynamic turbulence mediated by the magnetorotational instability. Despite an abundant literature on the MRI, the parameters governing the saturation amplitude of the turbulence are poorly understood and the existence of an asymptotic behavior in the Ohmic diffusion regime is not clearly established. We investigate the properties of the turbulent state in the small magnetic Prandtl number limit. Since this is extremely computationally expensive, we also study the relevance and range of applicability of the most common subgrid scale models for this problem. Unstratified shearing boxes simulations are performed both in the compressible and incompressible limits, with a resolution up to 800 cells per disc scale height. The latter constitutes the largest resolution ever attained for a simulation of MRI turbulence. In the presence of a mean magnetic field threading the domain, angular momentum transport converges to a finite va...

  10. The four-jet structure of large transverse momentum events in pp interactions at the ISR

    Microsoft Academic Search

    A. Breakstone; C. D. Buchanan; H. B. Crawley; K. Doroba; D. Drijard; F. Fabbri; A. Firestone; H. G. Fischer; H. Frehse; G. Giacomelli; W. Geist; R. Gokieli; P. Hanke; M. Heiden; W. Herr; W. Hofmann; P. G. Innocenti; E. E. Kluge; J. W. Lamsa; T. Lohse; W. T. Meyer; G. Mornacchi; T. Nakada; M. Panter; A. Putzer; K. Rauschnabel; F. Rimondi; R. Sosnowski; M. Szczekowski; O. Ullaland; D. Wegener

    1984-01-01

    Deep inelastic proton-proton collisions have been recorded with the Split-Field-Magnet Detector (SFM) at the CERN Intersecting Storage Rings (ISR) by triggering on a single particle at high transverse momentum. Full reconstruction of the charged particles in these collisions was performed. In this paper we demonstrate the existence of a structure comprised of four jet-like clusters, two longitudinal and two transverse

  11. 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...

  12. Spin-longitudinal and spin-tranverse response of 40Ca to 500 MeV protons at low momentum transfer

    Microsoft Academic Search

    A. Green; W. Unkelbach; F. T. Baker; D. Beatty; L. Bimbot; X. Y. Chen; V. R. Cupps; C. Djalali; G. Edwards; R. W. Fergerson; C. Glashausser; K. W. Jones; M. K. Jones; G. Kumbartzki; A. Sethi; B. Storm; J. Wambach

    1993-01-01

    A complete set of diagonal spin-transfer observables has been measured at excitation energies between 30 and 40 MeV for inelastic proton scattering from 40Ca at 497 and 581 MeV at a momentum transfer of 0.56 fm-1. The longitudinal and transverse spin-flip probabilities are deduced. Their unequal enhancements relative to free nucleon-nucleon scattering values are explained by a distorted-wave impulse approximation

  13. Spin-longitudinal and spin-tranverse response of [sup 40]Ca to 500 MeV protons at low momentum transfer

    Microsoft Academic Search

    A. Green; W. Unkelbach; F. T. Baker; D. Beatty; L. Bimbot; X. Y. Chen; V. R. Cupps; C. Djalali; G. Edwards; R. W. Fergerson; C. Glashausser; K. W. Jones; M. K. Jones; G. Kumbartzki; A. Sethi; B. Storm; J. Wambach

    1993-01-01

    A complete set of diagonal spin-transfer observables has been measured at excitation energies between 30 and 40 MeV for inelastic proton scattering from [sup 40]Ca at 497 and 581 MeV at a momentum transfer of 0.56 fm[sup [minus]1]. The longitudinal and transverse spin-flip probabilities are deduced. Their unequal enhancements relative to free nucleon-nucleon scattering values are explained by a distorted-wave

  14. Laboratory investigations of the heat and momentum transfer in the stably stratified air turbulent boundary layer above the wavy surface

    NASA Astrophysics Data System (ADS)

    Sergeev, Daniil; Troitskaya, Yuliya; Vdovin, Maxim

    2015-04-01

    Investigation of small scale transfer processes between the ocean and atmosphere in the boundary and its parameterization on the meteorological conditions (wind and surface waves parameters) is very important for weather forecasts modeling [1]. The accuracy of the predictions taking in to account the so named bulk-formulas strongly depends on the quality empirical data. That is why the laboratory modeling sometimes is preferable (see [2]) then in situ measurements for obtaining enough ensembles of the data with a good accuracy in control conditions, first of all in a case of severe conditions (strong winds with intensive wave breaking and sprays generation). In this investigation laboratory modeling was performed on the Thermostratified Wind-Wave Channel of the IAP RAS (see. [3]). Experiments were carried out for the wind speeds up to 18.5 m/s (corresponding the equivalent 10-m wind speed 30 m/s). For the possibility of varying parameters of surface roughness independently on the wind flow a special system basing on the submerged mosquito mesh (cell of 2*2 mm) was used (see [4]). The roughness was controlled by the depth of the mesh installation under the free surface (no waves when the mesh was on the surface and maximum wave amplitude for the maximum depth). So, for each wind speed several cases of the waves parameters were investigated. During experiments a stable stratification of the boundary layer of air flow was obtained. Temperature of the heating air was 33-37 degrees (depending on the reference wind speed), and the water temperature was 14-16 degrees. The Pitote gauge and hotwire were used together for measuring velocity and temperature profiles. Also indirect estimations of the total volume of the phase of sprays were obtained by analyzing hotwire signals errors during droplets hits. Then aerodynamic drag CD and heat transfer Ch coefficients were obtained by profiling method. It was shown that that these parameters are very sensitive to the intensity of the spray of droplets generation, especially heat transfer. The work was supported by RFBR grants (14-05-91767, 14-08-31740, 15-35-20953) and RSF grant 14-17-00667 and by President grant for young scientists MK-3550.2014.5 References: 1. Emanuel, K. A. Sensitivity of tropical cyclones to surface exchange coefficients and a revised steady-state model incorporating eye dynamics // J. Atmos. Sci., 52(22), 3969-3976,1995. 2. Brian K. Haus, Dahai Jeong, Mark A. Donelan, Jun A. Zhang, and Ivan Savelyev Relative rates of sea-air heat transfer and frictional drag in very high winds // GEOPHYSICAL RESEARCH LETTERS, VOL. 37, L07802, doi:10.1029/2009GL042206, 2010 3. Yu. I. Troitskaya, D.A. Sergeev, A.A. Kandaurov, G.A Baidakov, M.A. Vdovin, V.I. Kazakov Laboratory and theoretical modeling of air-sea momentum transfer under severe wind conditions // JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 117, C00J21, 13 PP., 2012 doi:10.1029/2011JC007778 4. Yu.I.Troitskaya, D.A.Sergeev, A.A.Kandaurov, M.I. Vdovin, A.A. Kandaurov, E.V.Ezhova, S.S.Zilitinkevich Momentum and buoyancy exchange in a turbulent air boundary layer over a wavy water surface. Part 2. Wind wave spectra // Nonlinear. Geoph. Processes, Vol. 20, P. 841-856, 2013.

  15. Monte Carlo spectra integration: A consistent approximation for radiative transfer in large eddy simulations

    E-print Network

    Stevens, Bjorn

    Monte Carlo spectra integration: A consistent approximation for radiative transfer in large eddy-dynamical simulation. Current methods for detailed radiation calculations, even those using simple one is acceptable in radiative transfer treatments for large eddy simulation? The term "large-eddy simulation" (LES

  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. nucl-ex/98120024Dec1998 Large Momentum Transfer Measurements of the Deuteron Elastic Structure Function

    E-print Network

    Boyer, Edmond

    ,25 V. Breton,1 H. Breuer,17 E. Burtin,27 J.R. Calarco,19 L.S. Cardman,31 C. Cavata,27 C.-C. Chang,17'Hose,27 B. Diederich,22 J.J. Domingo,31 M.B. Epstein,2 L.A. Ewell,17 J.M. Finn,34 K.G. Fissum,18 H

  18. 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.

  19. 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.

  20. 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.

  1. Momentum Transfer Studies and Studies of Linear and Nonlinear Optical Properties of Metal Colloids and Semiconductor Quantum Dots

    NASA Technical Reports Server (NTRS)

    Collins, W. E.; Burger, A.; Dyer, K.; George, M.; Henderson, D.; Morgan, S.; Mu, R.; Shi, D.; Conner, D; Thompson, E.; Collins, L.; Curry, L.; Mattox, S.; Williams, G.

    1996-01-01

    Phase 1 of this work involved design work on a momentum transfer device. The progress on design and testing will be presented. Phase 2 involved the systematic study of the MPD thruster for dual uses. Though it was designed as a thruster for space vehicles, the characteristics of the plasma make it an excellent candidate for industrial applications. This project sought to characterize the system for use in materials processing and characterization. The surface modification on ZnCdTe, CdTe, and ZnTe will be presented. Phase 3 involved metal colloids and semiconductor quantum dots. One aspect of this project involves a collaborative effort with the Solid State Division of ORNL. The thrust behind this research is to develop ion implantation for synthesizing novel materials (quantum dots wires and wells, and metal colloids) for applications in all optical switching devices, up conversion, and the synthesis of novel refractory materials. The ions of interest are Au, Ag, Cd, Se, In, P, Sb, Ga, and As. The specific materials of interest are: CdSe, CdTe, InAs, GaAs, InP, GaP, InSb, GaSb, and InGaAs. A second aspect of this research program involves using porous glass (25-200 A) for fabricating materials of finite size. The results of some of this work will also be reported.

  2. 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 ...

  3. Synchronized Phasor Data Based Energy Function Analysis of Dominant Power Transfer Paths in Large Power Systems

    Microsoft Academic Search

    Joe H. Chow; Aranya Chakrabortty; Murat Arcak; Bharat Bhargava; Armando Salazar

    2007-01-01

    Many large interconnected power systems such as the U.S. eastern interconnection and the U.S. western power system are characterized by many power transfer paths or interfaces with high loading. Disruptions of these transfer paths frequently lead to increased loading on neighboring transfer paths, which themselves will become less secure and could cause further disruptions. State estimators have limited performance under

  4. Large eddy simulation of flow and heat transfer in a channel with a detached rib array

    Microsoft Academic Search

    Joon Ahn; Joon Sik Lee

    2010-01-01

    Ribbed channels are widely used to enhance heat transfer in various heat exchange equipment. However, the heat transfer is locally deteriorated immediately behind the rib due to the flow separation. To overcome this shortcoming, a detached rib array has been proposed recently. In the present study, large eddy simulations (LES) of turbulent flow and heat transfer in a channel with

  5. Integrating Multiple and Heterogeneous Challenged Networks for Large-Sized Data Transfer

    Microsoft Academic Search

    Akira Nagata; Shinya Yamamura; Masato Tsuru

    2009-01-01

    The present paper is motivated by the question how we can quickly transfer large-sized file if multiple (heterogeneous) networks are available but each of which has quite insufficient performance for the requested task. We propose a research framework for large-sized data transfer by integrating multiple and heterogeneous challenged access networks, in which long delays, leaks (heavy packet losses), and frequent

  6. 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)

  7. Cross sections for transfer of rotational angular momentum in CO2 from 13C spin relaxation studies in the gas phase

    Microsoft Academic Search

    Cynthia J. Jameson; A. Keith Jameson; Nancy C. Smith; Karol Jackowski

    1987-01-01

    Nuclear spin-lattice relaxation times (T1) have been measured for 13C in 13C16O2 in pure CO2 gas and in CH4, N2, Ar, HCl, Kr, Xe, and SF6 gases as a function of temperature. The relaxation is completely dominated by the spin-rotation mechanism so that empirical values of the cross sections for rotational angular momentum transfer ?J are obtained as a function

  8. Inelastic x-ray scattering at intermediate momentum transfer: Fluorescence spectrum and search for infrared divergence in scattered x-ray spectra

    Microsoft Academic Search

    Vincent Marchetti; Carl Franck

    1989-01-01

    We have measured the ratio of the fluorescence line intensities in the decay of a copper K-shell vacancy created in an inelastic-scattering event at intermediate momentum transfer. The measured value of the ratio of Kbeta line intensity to Kalpha line intensity is 0.07+\\/-0.05, consistent with the value observed for excitation by photoabsorption. We also present data on the spectrum of

  9. Higher-Twist Contributions to Large Transverse Momentum Hadron Production in hadronic collisions

    SciTech Connect

    Arleo, Francois; /Annecy, LAPTH; Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; Hwang, Dae Sung; /Sejong U.; Sickles, Anne M.; /Brookhaven

    2010-08-25

    The scaling behavior of large-p{sub {perpendicular}} hadron production in hadronic collisions is investigated. A significant deviation from the NLO QCD predictions is reported, especially at high values of x{sub {perpendicular}} = 2p{sub {perpendicular}}/{radical}s. In contrast, the prompt photon and jet production data prove in agreement with leading-twist expectations. These results are interpreted as coming from a non-negligible contribution of higher-twist processes, where the hadron is produced directly in the hard subprocess. Predictions for scaling exponents at RHIC are successfully compared to PHENIX preliminary measurements. We suggest to trigger on isolated large-p{sub {perpendicular}} hadron production to enhance higher-twist processes, and point that the use of isolated hadrons as a signal for new physics at colliders can be affected by the presence of direct hadron production processes.

  10. Searching for Dark Matter with the ATLAS Detector in Events with an Energetic Jet and Large Missing Transverse Momentum

    E-print Network

    Schramm, Steven

    Hadron colliders, such as the Large Hadron Collider (LHC), principally produce events involving hadronic activity. Such activity is typically modelled by jets, which provide a useful representation of the underlying physics. Given the ubiquity of jets in LHC events, it becomes important to ensure that their properties and performance are well understood. The full approach to jet reconstruction and calibration, as used by the ATLAS Experiment, is detailed with a focus on recent improvements. The systematic uncertainties associated with jets are quantified, with the procedures and resulting reductions in uncertainties thoroughly detailed. Extra attention is placed on the treatment of high energy jets, and particularly the impact of inactive calorimeter regions and calorimeter non-containment (punch-through). The mono-jet topology is presented as an analysis where high energy jets are particularly relevant. This search makes use of very high missing transverse momentum balanced purely by jets, enabling mea...

  11. 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

  12. Heat transfer in fluidized beds of low density, large-sized particles

    Microsoft Academic Search

    V. K. Arora

    1976-01-01

    Surface-to-bed heat transfer mechanisms in a fluidized bed of low density (bulk density 1 - 12 lb\\/tu. ft.) large-sized (particle dia. 1\\/4 - 1 1\\/4 in.) particles were investigated. Heat transfer coefficients were experimentally measured for different sets of particles and fluidization conditions. Results indicate that the heat transfer mechanism in such fluidized beds is different than that now generally

  13. Understanding the large-distance behavior of transverse-momentum-dependent parton densities and the Collins-Soper evolution kernel

    DOE PAGESBeta

    Collins, John; Rogers, Ted

    2015-04-01

    There is considerable controversy about the size and importance of non-perturbative contributions to the evolution of transverse momentum dependent (TMD) parton distribution functions. Standard fits to relatively high-energy Drell-Yan data give evolution that when taken to lower Q is too rapid to be consistent with recent data in semi-inclusive deeply inelastic scattering. Some authors provide very different forms for TMD evolution, even arguing that non-perturbative contributions at large transverse distance bT are not needed or are irrelevant. Here, we systematically analyze the issues, both perturbative and non-perturbative. We make a motivated proposal for the parameterization of the non-perturbative part ofmore »the TMD evolution kernel that could give consistency: with the variety of apparently conflicting data, with theoretical perturbative calculations where they are applicable, and with general theoretical non-perturbative constraints on correlation functions at large distances. We propose and use a scheme- and scale-independent function A(bT) that gives a tool to compare and diagnose different proposals for TMD evolution. We also advocate for phenomenological studies of A(bT) as a probe of TMD evolution. The results are important generally for applications of TMD factorization. In particular, they are important to making predictions for proposed polarized Drell- Yan experiments to measure the Sivers function.« less

  14. Understanding the large-distance behavior of transverse-momentum-dependent parton densities and the Collins-Soper evolution kernel

    DOE PAGESBeta

    Collins, John; Rogers, Ted

    2015-04-01

    There is considerable controversy about the size and importance of non-perturbative contributions to the evolution of transverse momentum dependent (TMD) parton distribution functions. Standard fits to relatively high-energy Drell-Yan data give evolution that when taken to lower Q is too rapid to be consistent with recent data in semi-inclusive deeply inelastic scattering. Some authors provide very different forms for TMD evolution, even arguing that non-perturbative contributions at large transverse distance bT are not needed or are irrelevant. Here, we systematically analyze the issues, both perturbative and non-perturbative. We make a motivated proposal for the parameterization of the non-perturbative part of the TMD evolution kernel that could give consistency: with the variety of apparently conflicting data, with theoretical perturbative calculations where they are applicable, and with general theoretical non-perturbative constraints on correlation functions at large distances. We propose and use a scheme- and scale-independent function A(bT) that gives a tool to compare and diagnose different proposals for TMD evolution. We also advocate for phenomenological studies of A(bT) as a probe of TMD evolution. The results are important generally for applications of TMD factorization. In particular, they are important to making predictions for proposed polarized Drell- Yan experiments to measure the Sivers function.

  15. Understanding the large-distance behavior of transverse-momentum-dependent parton densities and the Collins-Soper evolution kernel

    E-print Network

    John Collins; Ted Rogers

    2015-05-08

    There is considerable controversy about the size and importance of nonperturbative contributions to the evolution of transverse-momentum-dependent (TMD) parton distribution functions. Standard fits to relatively high-energy Drell-Yan data give evolution that when taken to lower Q is too rapid to be consistent with recent data in semi-inclusive deeply inelastic scattering. Some authors provide very different forms for TMD evolution, even arguing that nonperturbative contributions at large transverse distance b_T are not needed or are irrelevant. Here, we systematically analyze the issues, both perturbative and nonperturbative. We make a motivated proposal for the parameterization of the nonperturbative part of the TMD evolution kernel that could give consistency: with the variety of apparently conflicting data, with theoretical perturbative calculations where they are applicable, and with general theoretical nonperturbative constraints on correlation functions at large distances. We propose and use a scheme- and scale-independent function A(b_T) that gives a tool to compare and diagnose different proposals for TMD evolution. We also advocate for phenomenological studies of A(b_T) as a probe of TMD evolution. The results are important generally for applications of TMD factorization. In particular, they are important to making predictions for proposed polarized Drell-Yan experiments to measure the Sivers function.

  16. Development and assessment of a coupled strategy for conjugate heat transfer with Large Eddy Simulation.

    E-print Network

    Paris-Sud XI, Université de

    Development and assessment of a coupled strategy for conjugate heat transfer with Large Eddy development costs through important reductions of the number of experimental tests. When a Computational Fluid Dynamics (CFD) solver is coupled to a heat transfer solver, the accuracy of the coupled tool is generally

  17. DiskRouter: A Flexible Infrastructure for High Performance Large Scale Data Transfers

    Microsoft Academic Search

    George Kola; Miron Livny

    2003-01-01

    The steady increase in data sets of scientific applications, the trend towards collaborative research and the emergence of grid computing has created a need to move large quan- tities of data over wide-area networks. The dynamic nature of network makes it difficult to tune data transfer protocols to use the full bandwidth. Further, data transfers are limited by the bottleneck

  18. 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

  19. Proceedings of the ASME Heat Transfer and Fluids Engineering Divisions: Fluid mechanics and heat transfer in sprays; Heat, mass and momentum transfer in environmental flows; Measurement techniques in multiphase flow; Multiphase transport in porous media. HTD-Volume 321; FED-Volume 233

    Microsoft Academic Search

    J. W. Hoyt; C. Presser

    1995-01-01

    The 14 papers in the Fluid mechanics and heat transfer in sprays section have application to combustion sprays, spray cooling for fire fighting, cooling towers, and fuel atomization. The 22 papers in the Heat, mass and momentum transfer in environmental flows symposium are related to air pollution transport, air infiltration to building envelopes, climatic change, radionuclide transport, power plant stack

  20. Comparison of wire and fiber optics data transfer systems for large military aircraft

    Microsoft Academic Search

    Kenneth Trumble; Charlotte C. Zelon

    1979-01-01

    Methods for comparing the life-cycle cost of fiber optics and wire data transfer systems on large military aircraft are established. Using the B-1 as an example, the applicability of fiber optics to avionics\\/electrical systems on large aircraft is identified. Conceptual fiber optics data transfer systems are described. The present wire and the conceptual fiber optics designs form a basis for

  1. 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...

  2. Reliable, Automatic Transfer and Processing of Large Scale Astronomy Datasets

    NASA Astrophysics Data System (ADS)

    Kosar, T.; Kola, G.; Livny, M.; Brunner, R. J.; Remjian, M.

    2005-12-01

    Astronomers are increasingly obtaining larger datasets, particularly in the optical and near-infrared. Unfortunately, the technologies to process large amounts of image data and share the data and the results with collaborators spread around the globe, have not kept pace with the data flow. In the past, this type of software has required significant human involvement to deal with failures. We have designed and implemented a fault-tolerant system that can process large amounts of astronomy images using idle CPUs on desktops, commodity clusters and grid resources. It reliably replicates data and results to collaborating sites and performs on-the-fly optimization to improve throughput. It is highly resilient to failures and can recover automatically from network, storage server, software and hardware failures. To demonstrate the capabilities of this framework, we have successfully processed three terabytes of DPOSS images using idle grid resources spread across three organizations.

  3. Engel et al. Reply: In our Letter [1] we have experimen tally shown that angular momentum can be transferred

    E-print Network

    Engel, Andreas

    Engel et al. Reply: In our Letter [1] we have experimen­ tally shown that angular momentum can­ sions. A. E. acknowledges financial support from the Volkswagenstiftung. Andreas Engel 1,2, * and Peter: 10.1103/PhysRevLett.92.188902 PACS numbers: 05.40.--a, 82.70.--y, 75.50.Mm *Electronic address: engel

  4. 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

  5. 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 ...

  6. 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%.

  7. Search for new phenomena in events with a monojet and large missing transverse momentum at the LHC using the ATLAS detector

    E-print Network

    Mario Martinez; for the ATLAS Collaboration

    2012-02-01

    We report preliminary results on a search for new phenomena in an event sample with monojets and large missing transverse momentum in the final state. The analysis uses 1.00 fb-1 of data collected in 2011 with the ATLAS detector. Good agreement is observed between the number of events in data and the Standard Model predictions. The results are translated into improved limits on a model with Large Extra Dimensions.

  8. Diffuse x-ray scattering from short-period W/C multilayers at in-plane momentum transfers 0.10-0.17 {angstrom}{sup -1}.

    SciTech Connect

    Headrick, R. L.; Liu, C. L.; Macrander, A. T.

    1999-04-20

    X-ray scattering measurements at 10 keV from multilayers having a period of 24.8 {angstrom} and consisting of 100 W/C bilayers are reported. Specular scans revealed first-order reflectivities in the range 73.5% to 78.0% with bandpasses in the range of 1.5% to 1.7%. Total roughness (or interface grading) values deduced from fitting to the specular data only were in the range 2.5 to 3.0 {angstrom} for the last-to-grow surface of the W layers. Diffuse scattering measurements were made in a geometry that permitted investigation of in-plane momentum transfers up to 0.17 {angstrom}{sup {minus}1}. This is roughly an order of magnitude larger than is possible in conventional rocking scans. Reasonable fitting results were obtained for an in-plane correlation function that has a Fourier transform proportional to exp(-vq{sub y}{sup 2}{vert_bar}z{sub i}-z{sub j}{vert_bar}), where z{sub i}-z{sub j} is the average separation between the i{sup th} and j{sup th} interfaces and q{sub y} is the in-plane momentum transfer.

  9. 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.

  10. 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

  11. 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.

  12. Bc meson enhancement and the momentum dependence in Pb + Pb collisions at energies available at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Liu, Yunpeng; Greiner, Carsten; Kostyuk, Andriy

    2013-01-01

    Bc meson production in Pb+Pb collisions at s=2.76ATeV is surveyed in both a statistical coalescence model and a transport model. The nuclear modification factor RAA is predicted to be between 2 and 18 in the most central collisions, which can help to confirm the regeneration mechanism. In addition, the momentum dependence is also investigated as given by the transport model. A strong suppression of the transverse momentum is found in central collisions accompanying the enhancement in yield. The spectrum and elliptic flow of Bc are also discussed.

  13. Turbulent transfer of momentum and heat in a separated and reattached flow over a blunt flat plate

    NASA Astrophysics Data System (ADS)

    Ota, T.; Kon, N.

    1980-11-01

    Turbulent shear stress and heat flux were measured with a hot-wire anemometer in the separated, reattached, and redeveloped regions of a two-dimensional incompressible air flow over a flat plate of finite thickness having blunt leading edge. The characteristic features of the turbulent heat flux are found to be nearly equal to those of the turbulent shear stress in the separated and reattached flow regions. However, in the turbulent boundary layer downstream from the reattachment point, the development of turbulent heat flux appears to be much quicker than that of turbulent shear stress. Eddy diffusivities of momentum and heat are evaluated and then the turbulent Prandtl number is estimated in the thermal layer downstream of reattachment. These results are compared with the available previous data.

  14. 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,

  15. 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.

  16. LAYER TRANSFER OF LARGE AREA MACROPOROUS SILICON FOR MONOCRYSTALLINE THIN-FILM SOLAR CELLS

    E-print Network

    LAYER TRANSFER OF LARGE AREA MACROPOROUS SILICON FOR MONOCRYSTALLINE THIN-FILM SOLAR CELLS Marco Hannover, Germany ABSTRACT We produce uniform macroporous double-layers on 6 inch n-type silicon substrates-standing macroporous silicon layers with an area of 8 x 8 cm 2 . INTRODUCTION The standard thickness of Si wafer

  17. Experience Transfer for the Configuration Tuning in Large-Scale Computing Systems

    Microsoft Academic Search

    Haifeng Chen; Wenxuan Zhang; Guofei Jiang

    2011-01-01

    This paper proposes a new strategy, the experience transfer, to facilitate the management of large-scale computing systems. It deals with the utilization of management experiences in one system (or previous systems) to benefit the same management task in other systems (or current systems). We use the system configuration tuning as a case application to demonstrate all procedures involved in the

  18. Conjugate Heat Transfer with Large Eddy Simulation for Gas Turbine Components.

    E-print Network

    Nicoud, Franck

    Conjugate Heat Transfer with Large Eddy Simulation for Gas Turbine Components. Florent Duchaine constraint for GT (gas turbines). Most existing CHT tools are developped for chained, steady phenomena. A film-cooled turbine vane is then studied. Thermal conduction in the blade implies lower wall

  19. INTERIOR CONVECTIVE HEAT TRANSFER IN BUILDINGS WiTH LARGE VENTiLATIVE FLOW RATES

    Microsoft Academic Search

    C. O. Pedersen; D. E. Fisher

    This paper presents the results obtained from a new experimental facility designed to investigate convective heat transfer. It is described in a companion paper. A large number of experiments were performed with varying inlet locations and sizes, inlet temperatures, and flow rates. The rootn outlet temperature was identified as the most suitable reference temperature for the calculation of film coeffi-

  20. Momentum-Transfer-Resolved Electron Energy Loss Spectroscopy of BaBiO3: Anisotropic Dispersion of Threshold Excitation and Optically Forbidden Transition

    NASA Astrophysics Data System (ADS)

    Wang, Y. Y.; Dravid, V. P.; Bulut, N.; Han, P. D.; Klein, M. V.; Schnatterly, S. E.; Zhang, F. C.

    1995-09-01

    Momentum-transfer-resolved electron energy loss spectroscopy of the valence band transitions in BaBiO3 has revealed for the first time that dispersion of the excitation at the optical gap \\(~2 eV\\) and an optically forbidden transition at 4.5 eV are all anisotropic along [100] and [110]. The anisotropic dispersion of the threshold excitation cannot be described by a simple charge density wave picture but can be explained by a small exciton model proposed in this paper. The optically forbidden transition is found to agree well with a proposed molecular orbital model, where the transition is assigned as the excitation from the O 2p? nonbonding states to the empty Bi 6s state.

  1. ANGULAR MOMENTUM L Angular Momentum

    E-print Network

    ANGULAR MOMENTUM L #12;#12;#12;#12;#12;#12;p-6' Angular Momentum Case: A few particles Example: This example emphasizes the fact that the value of the angular momentum of a system of particles depends just for reference.). v v v 1 2 3 Calculate the vector angular momentum of the three-particle system

  2. Mass-energy radiative transfer and momentum extraction by gravitational wave emission in the collision of two black holes

    SciTech Connect

    Aranha, R. F.; Soares, I. Damiao; Tonini, E. V. [Centro Brasileiro de Pesquisas Fisicas/MCT, Rua Dr. Xavier Sigaud, 150, CEP 22290-180, Rio de Janeiro, RJ (Brazil); Centro Federal de Educacao Tecnologica do Espirito Santo, Avenida Vitoria, 1729, CEP 29040-780, Vitoria, ES (Brazil)

    2010-05-15

    We examine numerically the head-on collision of two boosted Schwarzschild black holes, in the realm of Robinson-Trautman spacetimes. Characteristic initial data for the system are constructed and the Robinson-Trautman equation is integrated for these data using a numerical code based on the Galerkin-collocation method. The initial data already have a common horizon so that the evolution covers the post-merger regime up to the final configuration, when the gravitational wave emission ceases. In the nonlinear regime gravitational waves are emitted, extracting mass and linear momentum from the system. The final configuration is a boosted Schwarzschild black hole with rest mass larger than the masses of the two individual initial black holes, and with a smaller final boost parameter characterizing the recoil velocity of the remnant. The efficiency {Delta} of the mass-energy extraction by gravitational waves is evaluated. The points ({Delta},y), where y is the (normalized) rest mass of the remnant black hole, satisfy a nonextensive Tsallis distribution with entropic index q{approx_equal}1/2 for y < or approx. 12. Beyond y{approx}12 the experimental points deviate from the distribution function and the efficiency presents an absolute maximum for the case of equally massive individual colliding black holes; the remnant has no recoil in this case. By using the Bondi mass formula we also evaluate the total energy E{sub W} carried out by gravitational waves as well as the radiative corrections to the efficiency. E{sub W} increases monotonically with y and the experimental points (E{sub W},y) also satisfy a nonextensive Tsallis distribution but with q{approx_equal}2/3, up to y{approx}14.2. Beyond this value the experimental points increase faster than the distribution function. For any initial infalling velocity v, the distribution of momentum of the remnant exhibits a maximum at {alpha}{sub 1}={alpha}{sub m{approx_equal}}0.667, where {alpha}{sub 1} is related to the ratio of pre-merger rest masses, and has a one-to-one correspondence with y for fixed v. Two distinct regimes of gravitational wave emission can be characterized according to (i) {alpha}{sub 1}<{alpha}{sub m}: bursts of gravitational bremsstrahlung; (ii) {alpha}{sub 1}>{alpha}{sub m}: quiescent long time emission of gravitational waves. This picture is also sustained by the analysis of the time behavior of the power emitted (dE{sub W}/du).

  3. An experimental study of heat transfer in a large-scale turbine rotor passage

    NASA Technical Reports Server (NTRS)

    Blair, Michael F.

    1992-01-01

    An experimental study of the heat transfer distribution in a turbine rotor passage was conducted in a large-scale, ambient temperature, rotating turbine model. Heat transfer was measured for both the full-span suction and pressure surfaces of the airfoil as well as for the hub endwall surface. The objective of this program was to document the effects of flow three-dimensionality on the heat transfer in a rotating blade row (vs a stationary cascade). Of particular interest were the effects of the hub and tip secondary flows, tip leakage and the leading-edge horseshoe vortex system. The effect of surface roughness on the passage heat transfer was also investigated. Midspan results are compared with both smooth-wall and rough-wall finite-difference two-dimensional heat transfer predictions. Contour maps of Stanton number for both the rotor airfoil and endwall surfaces revealed numerous regions of high heat transfer produced by the three-dimensional flows within the rotor passage. Of particular importance are regions of local enhancement (as much as 100 percent over midspan values) produced on the airfoil suction surface by the secondary flows and tip-leakage vortices and on the hub endwall by the leading-edge horseshoe vortex system.

  4. 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

  5. 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

  6. Separation of the [sup 2]H([ital e],[ital e][prime][ital p]) structure functions up to 0. 9 GeV/[ital c] momentum transfer

    SciTech Connect

    Ducret, J.E.; Bernheim, M.; Danel, J.F.; Lakehal-Ayat, L.; Le Goff, J.M.; Magnon, A.; Marchand, C.; Morgenstern, J.; Vernin, P. (DAPNIA/Service de Physique Nucleaire, Centre d'Etudes de Saclay, 91191 Gif sur Yvette (France)); Brussel, M.K. (Department of Physics, University of Illinois, Urbana, Illinois 61801 (United States)); Arenhoevel, H.; Beck, G.; Wilbois, T. (Institut fuer Kernphysik der Universitaet Mainz, 55099 Mainz (Germany)); Capitani, G.P.; De Sanctis, E. (Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare, I-00044 Frascati (Italy)); Frullani, S.; Garibaldi, F.; Ghio, F.; Jodice, M. (Laboratori di Fisica, Istituto Superiore di Sanita and Istituto Nazionale di Fisica Nucleare, Sezione Sanita, I-00161 Roma (Italy))

    1994-04-01

    Longitudinal, transverse, and longitudinal-transverse structure functions for the [sup 2]H([ital e],[ital e][prime][ital p]) reaction have been determined. Measurements of the cross sections were made in-plane in nearly quasielastic kinematics spanning momentum transfers between 200 and 670 MeV/[ital c] and recoil momenta between 0 and 150 MeV/[ital c]. In addition, cross sections at momentum transfers above 800 MeV/[ital c] were measured at backward scattering angles in aligned kinematics where the response is predominantly transverse. We compared our data with both relativistic and nonrelativistic models. Our results are not consistently in agreement with any of the calculations based on these models. The disagreement between our data and these calculations ranges from 0% to 30%; on average it is about 10%. Notable discrepancies arise in describing relativistic effects for the longitudinal-transverse structure function, at a momentum transfer of 400 MeV/[ital c] as well as for the transverse structure function at momentum transfer above 800 MeV/[ital c].

  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. 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

  9. Evaluating Knowledge Transfer and Zero-Shot Learning in a Large-Scale Setting Marcus Rohrbach Michael Stark Bernt Schiele

    E-print Network

    Evaluating Knowledge Transfer and Zero-Shot Learning in a Large-Scale Setting Marcus Rohrbach.r.t. scalability we thus advocate to eval- uate KT in a large-scale setting. To this end, we provide an extensive evaluation of three popular approaches to KT on a recently proposed large-scale data set, the ImageNet Large

  10. 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.

  11. 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 ...

  12. New approach for producing chemical templates over large area by Molecular Transfer Printing

    NASA Astrophysics Data System (ADS)

    Inoue, Takejiro; Janes, Dustin; Ren, Jiaxing; Willson, Grant; Ellison, Christopher; Nealey, Paul

    2014-03-01

    Fabrication of well-defined chemically patterned surfaces is crucially important to the development of next generation microprocessors, hard disk memory devices, photonic/plasmonic devices, separation membranes, and biological microarrays. One promising patterning method in these fields is Molecular Transfer Printing (MTP), which replicates chemical patterns with feature dimensions of the order of 10nm utilizing a master template defined by the microphase separated domains of a block copolymer thin film. The total transfer printing area achievable by MTP has so far been limited by the contact area between two rigid substrates. Therefore, strategies to make conformal contact between substrates could be practically useful because a single lithographically-defined starting pattern could be used to fabricate many replicates by a low-cost process. Here we show a new approach that utilizes a chemically deposited SiN layer and a liquid conformal layer to enable transfer printing of chemical patterns upon thermal annealing over large, continuous areas. We anticipate that our process could be integrated into Step and Flash Imprint Lithography (SFIL) tools to achieve conformal layer thicknesses thin and uniform enough to permit pattern transfer through a dry-etch protocol.

  13. 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

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

    PubMed

    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; Giannazzo, Filippo

    2013-01-01

    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

  15. 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

  16. Measurements of momentum transfer coefficients for H{sub 2}, N{sub 2}, CO and CO{sub 2} incident upon spacecraft surfaces

    SciTech Connect

    Cook, S.R.; Hoffbauer, M.A.

    1997-07-16

    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 H{sub 2}, N{sub 2}, CO, and CO{sub 2} incident upon the solar array material, Kapton, SiO{sub 2}-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 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.

  17. Probing Proton Spin Structure: A Measurement of g2 at Four-momentum Transfer of 2 to 6 GeV(square)

    NASA Astrophysics Data System (ADS)

    Maxwell, James Davis

    The Spin Asymmetries of the Nucleon Experiment investigated the spin structure of the proton via inclusive electron scattering at the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory in Newport News, VA. A double-polarization measurement of polarized asymmetries was performed using the University of Virginia solid polarized ammonia target with target polarization aligned longitudinal and near transverse to the electron beam, allowing the extraction of the spin asymmetries A1 and A2, and spin structure functions g1 and g2. Polarized electrons of energies of 4.7 and 5.9 GeV were scattered to be viewed by a novel, non-magnetic array of detectors observing a four-momentum transfer range of 2 to 6 GeV 2. This document addresses the extraction of the spin asymmetries and spin structure functions, with a focus on spin structure function g2, which we have measured as a function of x and W in four Q2 bins.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. B (E2) strength ratio of one-phonon 2+ states of 94Zr from electron scattering at low momentum transfer

    NASA Astrophysics Data System (ADS)

    Scheikh Obeid, A.; Aslanidou, S.; Birkhan, J.; Krugmann, A.; von Neumann-Cosel, P.; Pietralla, N.; Poltoratska, I.; Ponomarev, V. Yu.

    2014-03-01

    Background: The B (E2) transition strength to the 22+ state in 94Zr was initially reported to be larger by a factor of 1.63 than the one to the 21+ state from lifetime measurements with the Doppler-shift attenuation method using the (n,n'?) reaction [Elhami et al., Phys. Rev. C 75, 011301(R) (2007), 10.1103/PhysRevC.75.011301]. This surprising behavior was recently revised in a new measurement by the same group using the same experimental technique leading to a ratio below unity as expected in vibrational nuclei. Purpose: The goal is an independent determination of the ratio of B (E2) strengths for the transitions to the 21,2+ states of 94Zr with inelastic electron scattering. Method: The relative population of the 21,2+ states in the (e,e') reaction was measured at the S-DALINAC in a momentum transfer range q =0.17-0.51 fm-1 and analyzed in plane-wave Born approximation with the method described by Scheikh Obeid et al. [Phys. Rev. C 87, 014337 (2013), 10.1103/PhysRevC.87.014337]. Results: The extracted B (E2) strength ratio of 0.789(43) between the excitation of the 21+ and 22+ states of 94Zr is consistent with but more precise than the latest (n,n'?) experiment. Using the B (E2) transition strength to the first excited state from the literature a value of 3.9(9) Weisskopf units is deduced for the B (E2;22+?01+) transition. Conclusions: The electron scattering result independently confirms the latest interpretation of the different (n,n'?) results for the transition to the 22+ state in 94Zr.

  3. RP4 promotion of transfer of a large Agrobacterium plasmid which confers virulence.

    PubMed

    Chilton, M D; Farrand, S K; Levin, R; Nester, E W

    1976-08-01

    Introduction of RP4 plasmid into Agrobacterium tumefaciens promotes the transfer on solid medium of large virulence-associated plasmids from virulent donor strains to a plasmidless avirulent recipient. Exconjugants were selected for the ability to utilize octopine or nopaline as the sole source of arginine, traits which are coded for by virulence-associated plasmids in the strains employed here. All exconjugants retained the arginine auxotrophy of the recipient strain, and were resistant to ampicillin and kanamycin, drugs to which RP4 confers resistance. Five exconjugant clones from one cross were shown by alkaline sucrose gradient analysis to contain both RP4 plasmid and the large virulence-associated plasmid of the donor strain. All five exconjugants exhibited virulence on carrot, sunflower and kalanchoe plants. These results indicate that virulence and the ability to degrade octopine are plasmid-borne traits in A. tumefaciens strains 15955 and A6, and extend the evidence that large plasmids in A. tumefaciens are vectors of virulence genes. PMID:971805

  4. Heat transfer and horizontally averaged temperature of convection with large viscosity variations

    NASA Technical Reports Server (NTRS)

    Richter, F. M.; Nataf, H.-C.; Daly, S. F.

    1983-01-01

    It is pointed out that the understanding of convection in large-Prandtl-number Boussinesq fluids with uniform properties and contained in simple geometries is virtually complete. Present efforts are typically directed towards relaxing some of the original assumptions by going to lower Prandtl number, more complicated geometries, variable material properties, or introducing new dynamical processes such as the Lorentz forces. A description is given of experiments which are concerned with the effect on convection of relaxing the assumption of a uniform viscosity. The reported experiments were designed to measure both the horizontally averaged temperature as a function of depth and the heat transfer of convection over a range of viscosity variations up to 100,000.

  5. 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.

  6. 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

  7. Momentum and Sensible Heat Exchange in an Ice-Free Arctic Fjord

    NASA Astrophysics Data System (ADS)

    Kilpeläinen, Tiina; Sjöblom, Anna

    2010-01-01

    Momentum and sensible heat exchange are studied in an Arctic fjord system in Spitsbergen, Svalbard (Norway), based on tower measurements taken in January-June 2008. Due to ice-free conditions, the surface layer was unstable for most of the time, occasionally very unstable. The shape of the fjord and the surrounding topography have a large influence on the wind field. Low frequency eddies are mainly responsible for occasionally large crosswind momentum transfer that, together with upward momentum transfer (occurring in 9% of the data), invalidate conventional stability and scaling parameters. When the flow is along the fjord with moderate or high wind speeds, the Monin-Obukhov similarity theory is applicable. However, the momentum and the sensible heat exchange in the fjord system differs from the exchange taking place over the open ocean, mainly due to topographic effects.

  8. Proceedings of the ASME Heat Transfer and Fluids Engineering Divisions: Fluid mechanics and heat transfer in sprays; Heat, mass and momentum transfer in environmental flows; Measurement techniques in multiphase flow; Multiphase transport in porous media. HTD-Volume 321; FED-Volume 233

    SciTech Connect

    Hoyt, J.W. [ed.] [San Diego State Univ., CA (United States); O`Hern, T.J. [ed.] [Sandia National Labs., Albuquerque, NM (United States); Presser, C. [ed.] [National Inst. of Standards and Technology, Gaithersburg, MD (United States)] [and others

    1995-12-31

    The 14 papers in the Fluid mechanics and heat transfer in sprays section have application to combustion sprays, spray cooling for fire fighting, cooling towers, and fuel atomization. The 22 papers in the Heat, mass and momentum transfer in environmental flows symposium are related to air pollution transport, air infiltration to building envelopes, climatic change, radionuclide transport, power plant stack plumes, flow through geologic repositories of radioactive wastes, and intake flow to cooling towers. There are 36 papers which discuss measurement techniques in multiphase flow. The symposium on Multiphase transport in porous media contains 14 papers related to enhanced recovery of petroleum, remedial action of soil and groundwater, and hydrogen storage as hydrides. Most papers have been processed separately for inclusion on the data base.

  9. Factors affecting success of embryo collection and transfer in large dairy herds.

    PubMed

    Chebel, R C; Demétrio, D G B; Metzger, J

    2008-01-01

    Our objective was to evaluate factors that affected the success of embryo transfer programs in large dairy herds. Non-lactating donor cows produced a larger number of ova/embryos (P<0.01) and viable embryos (P<0.01) than lactating cows. The interaction between season and donor class was correlated with the proportion of ova/embryos classified as fertilized (P=0.03), because lactating donors had fewer fertilized ova in the summer. There was no correlation between 305-day mature equivalent milk yield and response to superstimulation. Although the interval between superstimulation protocols was correlated with the number of ova/embryos (P=0.03), there was no correlation with the number of viable embryos. Pregnancy per embryo transfer (P/ET) in heifer recipients was correlated with embryo quality grade (P<0.01), season (P=0.04), and whether embryos were fresh or frozen/thawed (P<0.01). Lactating recipient cows tended to have a lower rate of P/ET during the summer (P=0.12 to P=0.08). Synchronization protocols tended to be (P=0.06; Herd 1) or were (P=0.02; Herd 2) correlated with P/ET. Lactating cows receiving vitrified IVF embryos had a lower (P=0.01) P/ET than those receiving fresh IVF embryos, especially in the summer (P=0.09). Milk yield was not correlated with P/ET. The use of heat abatement systems is critical to improve embryo production and P/ET. Synchronization protocols that optimized synchrony of ovulation may increase fertility of recipient cows and eliminate the need for estrous detection. PMID:18023856

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

    DOE PAGESBeta

    Aad, G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; Abramowicz, H.; Abreu, H.; et al

    2012-01-01

    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 limitmore »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.« less

  11. Search for diphoton events with large missing transverse momentum in 1 fb(-1) of 7 TeV proton-proton collision data with the ATLAS detector

    SciTech Connect

    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.; et al.

    2012-04-20

    A search for diphoton events with large missing transverse momentum has been performed using 1.07 fb{sup -1} of proton-proton collision data at {radical}s = 7 TeV recorded with the ATLAS detector. No excess of events was observed above the Standard Model prediction and 95% Confidence Level (CL) upper limits are set on the production cross section for new physics. The limits depend on each model parameter space and vary as follows: {sigma} < (22-129) fb in the context of a generalized model of gauge-mediated supersymmetry breaking (GGM) with a bino-like lightest neutralino, {sigma} < (27-91) fb in the context of a minimal model of gauge-mediated supersymmetry breaking (SPS8), and {sigma} < (15-27) fb in the context of a specific model with one universal extra dimension (UED). A 95% CL lower limit of 805 GeV, for bino masses above 50 GeV, is set on the GGM gluino mass. Lower limits of 145 TeV and 1.23 TeV are set on the SPS8 breaking scale {Lambda} and on the UED compactification scale 1/R, respectively. These limits provide the most stringent tests of these models to date.

  12. Search for diphoton events with large missing transverse momentum in 1 fb^-1 of 7 TeV proton-proton collision data with the ATLAS detector

    E-print Network

    ATLAS Collaboration

    2012-04-08

    A search for diphoton events with large missing transverse momentum has been performed using 1.07 fb^-1 of proton-proton collision data at sqrt(s) = 7 TeV recorded with the ATLAS detector. No excess of events was observed above the Standard Model prediction and 95% Confidence Level (CL) upper limits are set on the production cross section for new physics: sigma fb in the context of a generalised model of gauge-mediated supersymmetry breaking (GGM) with a bino-like lightest neutralino, sigma fb in the context of a minimal model of gauge-mediated supersymmetry breaking (SPS8) and (15-27) fb in the context of a specific model with one universal extra dimension (UED). A 95% CL lower limit of 805 GeV, for bino masses above 50 GeV, is set on the GGM gluino mass. Lower limits of 145 TeV and 1.23 TeV are set on the SPS8 breaking scale Lambda and on the UED compactification scale 1/R, respectively. These limits provide the most stringent tests of these models to date.

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

    DOE PAGESBeta

    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.; Åkesson, 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.; Åsman, 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.

    2012-01-01

    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.

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

    E-print Network

    ATLAS Collaboration

    2012-09-04

    A search for diphoton events with large missing transverse momentum has been performed using proton-proton collision data at sqrt(s) = 7 TeV recorded with the ATLAS detector, corresponding to an integrated luminosity of 4.8 fb^-1. No excess of events was observed above the Standard Model prediction and model-dependent 95% confidence level exclusion limits are set. In the context of a generalised model of gauge-mediated supersymmetry breaking with a bino-like lightest neutralino of mass above 50 GeV, gluinos (squarks) below 1.07 TeV (0.87 TeV) are excluded, while a breaking scale Lambda below 196 TeV is excluded for a minimal model of gauge-mediated supersymmetry breaking. For a specific model with one universal extra dimension, compactification scales 1/R < 1.40 TeV are excluded. These limits provide the most stringent tests of these models to date.

  15. Realization of Large-Area Wrinkle-Free Monolayer Graphene Films Transferred to Functional Substrates

    PubMed Central

    Park, Byeong-Ju; Choi, Jin-Seok; Kim, Hyun-Suk; Kim, Hyun-You; Jeong, Jong-Ryul; Choi, Hyung-Jin; Jung, Hyun-June; Jung, Min-Wook; An, Ki-Seok; Yoon, Soon-Gil

    2015-01-01

    Structural inhomogeneities, such as the wrinkles and ripples within a graphene film after transferring the free-standing graphene layer to a functional substrate, degrade the physical and electrical properties of the corresponding electronic devices. Here, we introduced titanium as a superior adhesion layer for fabricating wrinkle-free graphene films that is highly applicable to flexible and transparent electronic devices. The Ti layer does not influence the electronic performance of the functional substrates. Experimental and theoretical investigations confirm that the strong chemical interactions between Ti and any oxygen atoms unintentionally introduced on/within the graphene are responsible for forming the clean, defect-free graphene layer. Our results accelerate the practical application of graphene-related electronic devices with enhanced functionality. The large-area monolayer graphenes were prepared by a simple attachment of the Ti layer with the multi-layer wrinkle-free graphene films. For the first time, the graphene films were addressed for applications of superior bottom electrode for flexible capacitors instead of the novel metals. PMID:26043868

  16. 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

  17. 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

  18. Realization of large-area wrinkle-free monolayer graphene films transferred to functional substrates.

    PubMed

    Park, Byeong-Ju; Choi, Jin-Seok; Kim, Hyun-Suk; Kim, Hyun-You; Jeong, Jong-Ryul; Choi, Hyung-Jin; Jung, Hyun-June; Jung, Min-Wook; An, Ki-Seok; Yoon, Soon-Gil

    2015-01-01

    Structural inhomogeneities, such as the wrinkles and ripples within a graphene film after transferring the free-standing graphene layer to a functional substrate, degrade the physical and electrical properties of the corresponding electronic devices. Here, we introduced titanium as a superior adhesion layer for fabricating wrinkle-free graphene films that is highly applicable to flexible and transparent electronic devices. The Ti layer does not influence the electronic performance of the functional substrates. Experimental and theoretical investigations confirm that the strong chemical interactions between Ti and any oxygen atoms unintentionally introduced on/within the graphene are responsible for forming the clean, defect-free graphene layer. Our results accelerate the practical application of graphene-related electronic devices with enhanced functionality. The large-area monolayer graphenes were prepared by a simple attachment of the Ti layer with the multi-layer wrinkle-free graphene films. For the first time, the graphene films were addressed for applications of superior bottom electrode for flexible capacitors instead of the novel metals. PMID:26043868

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

    PubMed

    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. Position and momentum tomography

    E-print Network

    Jukka Kiukas; Pekka Lahti; Jussi Schultz

    2009-02-23

    We illustrate the use of the statistical method of moments for determining the position and momentum distributions of a quantum object from the statistics of a single measurement. The method is used for three different, though related, models; the sequential measurement model, the Arthurs-Kelly model and the eight-port homodyne detection model. In each case, the method of moments gives the position and momentum distribution for a large class of initial states, the relevant condition being the exponential boundedness of the distributions.

  1. Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb[superscript ?1] of ?s = 7 TeV proton-proton collisions

    E-print Network

    Taylor, Frank E.

    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[superscript ?1] of pp collision data at ?s = 7 TeV collected by the ATLAS ...

  2. 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 ...

  3. 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 ...

  4. Radiative Transfer Modeling of a Large Pool Fire by Discrete Ordinates, Discrete Transfer, Ray Tracing, Monte Carlo and Moment Methods

    NASA Technical Reports Server (NTRS)

    Jensen, K. A.; Ripoll, J.-F.; Wray, A. A.; Joseph, D.; ElHafi, M.

    2004-01-01

    Five computational methods for solution of the radiative transfer equation in an absorbing-emitting and non-scattering gray medium were compared on a 2 m JP-8 pool fire. The temperature and absorption coefficient fields were taken from a synthetic fire due to the lack of a complete set of experimental data for fires of this size. These quantities were generated by a code that has been shown to agree well with the limited quantity of relevant data in the literature. Reference solutions to the governing equation were determined using the Monte Carlo method and a ray tracing scheme with high angular resolution. Solutions using the discrete transfer method, the discrete ordinate method (DOM) with both S(sub 4) and LC(sub 11) quadratures, and moment model using the M(sub 1) closure were compared to the reference solutions in both isotropic and anisotropic regions of the computational domain. DOM LC(sub 11) is shown to be the more accurate than the commonly used S(sub 4) quadrature technique, especially in anisotropic regions of the fire domain. This represents the first study where the M(sub 1) method was applied to a combustion problem occurring in a complex three-dimensional geometry. The M(sub 1) results agree well with other solution techniques, which is encouraging for future applications to similar problems since it is computationally the least expensive solution technique. Moreover, M(sub 1) results are comparable to DOM S(sub 4).

  5. Position Measurements Obeying Momentum Conservation

    E-print Network

    Paul Busch; Leon Loveridge

    2011-02-24

    We present a hitherto unknown fundamental limitation to a basic measurement: that of the position of a quantum object when the total momentum of the object and apparatus is conserved. This result extends the famous Wigner-Araki-Yanase (WAY) theorem, and shows that accurate position measurements are only practically feasible if there is a large momentum uncertainty in the apparatus.

  6. Large Stokes shift induced by intramolcular charge transfer in N,O-chelated naphthyridine-BF2 complexes.

    PubMed

    Wu, Yun-Ying; Chen, Yong; Gou, Gao-Zhang; Mu, Wei-Hua; Lv, Xiao-Jun; Du, Mei-Ling; Fu, Wen-Fu

    2012-10-19

    Novel N,O-chelated naphthyridine-BF(2) complexes with push-pull structures have been synthesized and characterized. Spectral investigations on these complexes reveal that photoinduced intramolecular charge transfer occurs and results in a large Stokes shift, which is further supported by density functional theory based theoretical calculations. PMID:23050580

  7. 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

  8. Lateral homogeneity of porous silicon for large area transfer solar cells

    Microsoft Academic Search

    O. Tobail; Z. Yan; M. Reuter; J. H. Werner

    2008-01-01

    Transfer solar cells are monocrystalline silicon thin film cells grown epitaxially on annealed double layer porous silicon then transferred from the host wafer onto a foreign substrate. Porous silicon forms by electrochemical etching of the silicon wafer in hydrofluoric acid. An upper low porosity layer forms at low etch current density and a buried high porosity layer forms by increasing

  9. 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

  10. 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

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

    NASA Astrophysics Data System (ADS)

    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 ?m2. 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 mm2, yielding good statistic results.

  12. Plasma momentum meter for momentum flux measurements

    SciTech Connect

    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.

  13. 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.

  14. Heat transfer processes during intermediate and large break loss-of-coolant accidents (LOCAs)

    SciTech Connect

    Vojtek, I

    1986-09-01

    The general purpose of this project was the investigation of the heat transfer regimes during the high pressure portion of blowdown. The main attention has been focussed on the evaluation of those phenomena which are most important in reactor safety, such as maximum and minimum critical heat flux and forced convection film boiling heat transfer. The experimental results of the 25-rod bundle blowdown heat transfer tests, which were performed at the KWU heat transfer test facility in Karlstein, were used as a database for the verification of different correlations which are used or were developed for the analysis of reactor safety problems. The computer code BRUDI-VA was used for the calculation of local values of important thermohydraulic parameters in the bundle.

  15. Angular momentum from tidal torques

    Microsoft Academic Search

    Joshua Barnes; George Efstathiou

    1987-01-01

    The authors describe results for the origin of angular momentum of bound objects in large cosmological N-body simulations. Three sets of models are analyzed: one with white-noise initial conditions and two in which the initial conditions have more power on large scales, as predicted in models with cold dark matter (CDM). Statistical analysis of large catalogs of objects shows that

  16. Lipid transfer particle from the silkworm, Bombyx mori, is a novel member of the apoB/large lipid transfer protein family[S

    PubMed Central

    Yokoyama, Hiroshi; Yokoyama, Takeru; Yuasa, Masashi; Fujimoto, Hirofumi; Sakudoh, Takashi; Honda, Naoko; Fugo, Hajime; Tsuchida, Kozo

    2013-01-01

    Lipid transfer particle (LTP) is a high-molecular-weight, very high-density lipoprotein known to catalyze the transfer of lipids between a variety of lipoproteins, including both insects and vertebrates. Studying the biosynthesis and regulation pathways of LTP in detail has not been possible due to a lack of information regarding the apoproteins. Here, we sequenced the cDNA and deduced amino acid sequences for three apoproteins of LTP from the silkworm (Bombyx mori). The three subunit proteins of the LTP are coded by two genes, apoLTP-II/I and apoLTP-III. ApoLTP-I and apoLTP-II are predicted to be generated by posttranslational cleavage of the precursor protein, apoLTP-II/I. Clusters of amphipathic secondary structure within apoLTP-II/I are similar to Homo sapiens apolipoprotein B (apoB) and insect lipophorins. The apoLTP-II/I gene is a novel member of the apoB/large lipid transfer protein gene family. ApoLTP-III has a putative conserved juvenile hormone-binding protein superfamily domain. Expression of apoLTP-II/I and apoLTP-III genes was synchronized and both genes were primarily expressed in the fat body at the stage corresponding to increased lipid transport needs. We are now in a position to study in detail the physiological role of LTP and its biosynthesis and assembly. PMID:23812557

  17. Synthesis and Transfer of Large-Area Monolayer WS2 Crystals: Moving Toward the Recyclable Use of Sapphire Substrates.

    PubMed

    Xu, Zai-Quan; Zhang, Yupeng; Lin, Shenghuang; Zheng, Changxi; Zhong, Yu Lin; Xia, Xue; Li, Zhipeng; Sophia, Ponraj Joice; Fuhrer, Michael S; Cheng, Yi-Bing; Bao, Qiaoliang

    2015-06-23

    Two-dimensional layered transition metal dichalcogenides (TMDs) show intriguing potential for optoelectronic devices due to their exotic electronic and optical properties. Only a few efforts have been dedicated to large-area growth of TMDs. Practical applications will require improving the efficiency and reducing the cost of production, through (1) new growth methods to produce large size TMD monolayer with less-stringent conditions, and (2) nondestructive transfer techniques that enable multiple reuse of growth substrate. In this work, we report to employ atmospheric pressure chemical vapor deposition (APCVD) for the synthesis of large size (>100 ?m) single crystals of atomically thin tungsten disulfide (WS2), a member of TMD family, on sapphire substrate. More importantly, we demonstrate a polystyrene (PS) mediated delamination process via capillary force in water which reduces the etching time in base solution and imposes only minor damage to the sapphire substrate. The transferred WS2 flakes are of excellent continuity and exhibit comparable electron mobility after several growth cycles on the reused sapphire substrate. Interestingly, the photoluminescence emission from WS2 grown on the recycled sapphire is much higher than that on fresh sapphire, possibly due to p-type doping of monolayer WS2 flakes by a thin layer of water intercalated at the atomic steps of the recycled sapphire substrate. The growth and transfer techniques described here are expected to be applicable to other atomically thin TMD materials. PMID:25961515

  18. 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

  19. 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.

  20. 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

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

    E-print Network

    Rogers, John A.

    growth on silicon carbide substrates (SiC),7 9 and chemical vapor deposition (CVD) on metal surfaces.10 substrates to substrates of in- terest for device integration. In the case of CVD, etching the metal releases the graphene and prepares it for transfer, us- ing stamps or related processes.11 13 In this case, most

  2. 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

  3. Disentangling full and partial linear momentum transfer events in the {sup 16}O+{sup 169}Tm system at E{sub proj}{<=}5.4 MeV/nucleon

    SciTech Connect

    Gupta, Unnati; Singh, Pushpendra P.; Singh, Devendra P.; Sharma, Manoj Kumar; Yadav, Abhishek; Singh, B. P.; Prasad, R. [Accelerator Laboratory, Department of Physics, A. M. University, Aligarh 202 002 (India); Kumar, R. [NP-Group, Inter University Accelerator Center (IUAC), Post Office Box 10502, New Delhi (India); Gupta, S. [Department of Physics, Agra College, Agra (India); Bhardwaj, H. D. [Department of Physics, DSN College, Unnao (India)

    2009-08-15

    Forward recoil ranges of heavy reaction products have been measured to disentangle full and/or partial linear momentum transfer events in the {sup 16}O+{sup 169}Tm system at E{sub proj}{approx_equal}76 and 81 MeV. The experimentally measured forward recoil ranges of complete and/or incomplete fusion products are found to be in satisfactory agreement with that estimated using range-energy formulations. The angular distributions of several heavy reaction products have also been measured at E{sub proj}{approx_equal}81 MeV to get complementary information about incomplete fusion. To figure out the influence of incomplete fusion on complete fusion at such low projectile energies, the relative strengths of their contributions in {alpha}-emitting channel(s) have been deduced from the measurement of recoil range distributions.

  4. Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at root s(NN)=2.76 TeV

    Microsoft Academic Search

    K. Aamodt; A. A. Quintana; D. Adamova; A. M. Adare; M. M. Aggarwal; G. A. Rinella; A. G. Agocs; S. A. Salazar; Z. Ahammed; N. Ahmad; A. A. Masoodi; S. U. Ahn; A. Akindinov; D. Aleksandrov; B. Alessandro; R. A. Molina; A. Alici; A. Alkin; E. A. Avina; T. Alt; V. Altini; S. Altinpinar; I. Altsybeev; C. Andrei; A. Andronic; V. Anguelov; C. Anson; T. Anticic; F. Antinori; P. Antonioli; L. Aphecetche; H. Appelshauser; N. Arbor; S. Arcelli; A. Arend; N. Armesto; R. Arnaldi; T. Aronsson; I. C. Arsene; A. Asryan; A. Augustinus; R. Averbeck; T. C. Awes; J. Aysto; M. D. Azmi; M. Bach; A. Badala; Y. W. Baek; S. Bagnasco; R. Bailhache; R. Bala; R. B. Ferroli; A. Baldisseri; A. Baldit; J. Ban; R. Barbera; F. Barile; G. G. Barnafoldi; L. S. Barnby; V. Barret; J. Bartke; M. Basile; N. Bastid; B. Bathen; G. Batigne; B. Batyunya; C. Baumann; I. G. Bearden; H. Beck; I. Belikov; F. Bellini; R. Bellwied; E. Belmont-Moreno; S. Beole; I. Berceanu; A. Bercuci; E. Berdermann; Y. Berdnikov; L. Betev; A. Bhasin; A. K. Bhati; L. Bianchi; N. Bianchi; C. Bianchin; J. Bielcik; J. Bielcikova; A. Bilandzic; E. Biolcati; A. Blanc; F. Blanco; D. Blau; C. Blume; M. Boccioli; N. Bock; A. Bogdanov; H. Boggild; M. Bogolyubsky; L. Boldizsar; M. Bombara; C. Bombonati; H. Borel; C. Bortolin; S. Bose; F. Bossu; M. Botje; S. Bottger; B. Boyer; P. Braun-Munzinger; L. Bravina; M. Bregant; T. Breitner; M. Broz; R. Brun; E. Bruna; G. E. Bruno; D. Budnikov; H. Buesching; O. Busch; Z. Buthelezi; D. Caffarri; X. Cai; H. Caines; E. C. Villar; P. Camerini; V. C. Roman; G. C. Romeo; F. Carena; W. Carena; F. Carminati; A. C. Diaz; M. Caselle; J. C. Castellanos; V. Catanescu; C. Cavicchioli; P. Cerello; B. Chang; S. Chapeland; J. L. Charvet; S. Chattopadhyay; M. Cherney; C. Cheshkov; B. Cheynis; E. Chiavassa; V. C. Barroso; D. D. Chinellato; P. Chochula; M. Chojnacki; P. Christakoglou; C. H. Christensen; P. Christiansen; T. Chujo; C. Cicalo; L. Cifarelli; F. Cindolo; J. Cleymans; F. Coccetti; J. P. Coffin; S. Coli; G. C. Balbastre; Z. C. del Valle; P. Constantin; G. Contin; J. G. Contreras; T. M. Cormier; Y. C. Morales; I. C. Maldonado; P. Cortese; M. R. Cosentino; F. Costa; M. E. Cotallo; E. Crescio; P. Crochet; E. Cuautle; L. Cunqueiro; G. D. Erasmo; A. Dainese; H. H. Dalsgaard; A. Danu; D. Das; I. Das; A. Dash; S. Dash; S. De; A. D. Moregula; G. O. V. de Barros; A. De Caro; G. de Cataldo; J. de Cuveland; A. De Falco; D. De Gruttola; N. De Marco; S. De Pasquale; R. De Remigis; R. de Rooij; H. Delagrange; Y. D. Mercado; G. Dellacasa; A. Deloff; V. Demanov; E. Denes; A. Deppman; D. Di Bari; C. Di Giglio; S. Di Liberto; A. Di Mauro; P. Di Nezza; T. Dietel; R. Divia; O. Djuvsland; A. Dobrin; T. Dobrowolski; I. Dominguez; B. Donigus; O. Dordic; O. Driga; A. K. Dubey; J. Dubuisson; L. Ducroux; P. Dupieux; A. K. D. Majumdar; M. R. D. Majumdar; D. Elia; D. Emschermann; H. Engel; H. A. Erdal; B. Espagnon; M. Estienne; S. Esumi; D. Evans; S. Evrard; G. Eyyubova; C. W. Fabjan; D. Fabris; J. Faivre; D. Falchieri; A. Fantoni; M. Fasel; R. Fearick; A. Fedunov; D. Fehlker; V. Fekete; D. Felea; C. Feofilov; A. F. Tellez; A. Ferretti; R. Ferretti; M. A. S. Figueredo; S. Filchagin; R. Fini; D. Finogeev; F. M. Fionda; E. M. Fiore; M. Floris; S. Foertsch; P. Foka; S. Fokin; E. Fragiacomo; M. Fragkiadakis; U. Frankenfeld; U. Fuchs; F. Furano; C. Furget; M. F. Girard; J. J. Gaardhoje; S. Gadrat; M. Gagliardi; A. Gago; M. Gallio; P. Ganoti; C. Garabatos; R. Gemme; J. Gerhard; M. Germain; C. Geuna; A. Gheata; M. Gheata; B. Ghidini; P. Ghosh; M. R. Girard; G. Giraudo; P. Giubellino; E. Gladysz-Dziadus; P. Glassel; R. Gomez; L. H. Gonzalez-Trueba; P. Gonzalez-Zamora; H. G. Santos; S. Gorbunov; S. Gotovac; V. Grabski; R. Grajcarek; A. Grelli; A. Grigoras; C. Grigoras; V. Grigoriev; A. Grigoryan; S. Grigoryan; B. Grinyov; N. Grion; P. Gros; J. F. Grosse-Oetringhaus; J. Y. Grossiord; R. Grosso; F. Guber; R. Guernane; C. G. Gutierrez; B. Guerzoni; K. Gulbrandsen; T. Gunji; A. Gupta; R. Gupta; H. Gutbrod; O. Haaland; C. Hadjidakis; M. Haiduc; H. Hamagaki; G. Hamar; J. W. Harris; M. Hartig; D. Hasch; D. Hasegan; D. Hatzifotiadou; A. Hayrapetyan; M. Heide; M. Heinz; H. Helstrup; A. Herghelegiu; C. Hernandez; G. H. Corral; N. Herrmann; K. F. Hetland; B. Hicks; P. T. Hille; B. Hippolyte; T. Horaguchi; Y. Hori; P. Hristov; I. Hrivnacova; M. Huang; S. Huber; T. J. Humanic; D. S. Hwang; R. Ichou; R. Ilkaev; I. Ilkiv; M. Inaba; E. Incani; G. M. Innocenti; P. C. Innocenti; M. Ippolitov; M. Irfan; C. Ivan; A. Ivanov; M. Ivanov; V. Ivanov; A. Jacholkowski; P. M. Jacobs; L. Jancurova; S. Jangal; R. Janik; S. P. Jayarathna; S. Jena; L. Jirden; G. T. Jones; P. G. Jones; P. Jovanovic; H. Jung; W. Jung; A. Jusko; S. Kalcher; P. Kalinak; M. Kalisky; T. Kalliokoski; A. Kalweit; R. Kamermans; K. Kanaki; E. Kang; J. H. Kang; V. Kaplin; O. Karavichev; T. Karavicheva

    2011-01-01

    Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at root 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)

  5. Suppressed pi0 Production at Large Transverse Momentum in Central Au+Au Collisions at (sNN)=200 GeV

    Microsoft Academic Search

    S. S. Adler; S. Afanasiev; C. Aidala; N. N. Ajitanand; Y. Akiba; J. Alexander; R. Amirikas; L. Aphecetche; S. H. Aronson; R. Averbeck; T. C. Awes; R. Azmoun; V. Babintsev; A. Baldisseri; K. N. Barish; P. D. Barnes; B. Bassalleck; S. Bathe; S. Batsouli; V. Baublis; A. Bazilevsky; S. Bhagavatula; Y. Berdnikov; J. G. Boissevain; H. Borel; S. Borenstein; M. L. Brooks; D. S. Brown; N. Bruner; D. Bucher; H. Buesching; V. Bumazhnov; G. Bunce; J. M. Burward-Hoy; S. Butsyk; X. Camard; S. Chernichenko; P. Chand; W. C. Chang; C. Y. Chi; J. Chiba; M. Chiu; I. J. Choi; J. Choi; R. K. Choudhury; T. Chujo; V. Cianciolo; Y. Cobigo; B. A. Cole; P. Constantin; D. G. D'Enterria; G. David; H. Delagrange; A. Denisov; A. Deshpande; E. J. Desmond; O. Dietzsch; O. Drapier; A. Drees; K. A. Drees; R. Du Rietz; A. Durum; D. Dutta; Y. V. Efremenko; K. El Chenawi; A. Enokizono; H. En'yo; S. Esumi; L. Ewell; D. E. Fields; F. Fleuret; S. L. Fokin; B. D. Fox; Z. Fraenkel; J. E. Frantz; A. Franz; A. D. Frawley; S.-Y. Fung; S. Garpman; T. K. Ghosh; A. Glenn; G. Gogiberidze; M. Gonin; J. Gosset; Y. Goto; R. Granier de Cassagnac; N. Grau; S. V. Greene; M. Grosse Perdekamp; W. Guryn; H.-Å. Gustafsson; T. Hachiya; J. S. Haggerty; H. Hamagaki; A. G. Hansen; E. P. Hartouni; M. Harvey; R. Hayano; X. He; M. Heffner; T. K. Hemmick; J. M. Heuser; M. Hibino; J. C. Hill; W. Holzmann; K. Homma; B. Hong; A. Hoover; T. Ichihara; V. V. Ikonnikov; K. Imai; L. Isenhower; M. Ishihara; M. Issah; A. Isupov; B. V. Jacak; W. Y. Jang; Y. Jeong; J. Jia; O. Jinnouchi; B. M. Johnson; S. C. Johnson; K. S. Joo; D. Jouan; S. Kametani; N. Kamihara; J. H. Kang; S. S. Kapoor; K. Katou; S. Kelly; B. Khachaturov; A. Khanzadeev; J. Kikuchi; D. H. Kim; D. J. Kim; D. W. Kim; E. Kim; G.-B. Kim; H. J. Kim; E. Kistenev; A. Kiyomichi; K. Kiyoyama; C. Klein-Boesing; H. Kobayashi; L. Kochenda; V. Kochetkov; D. Koehler; T. Kohama; M. Kopytine; D. Kotchetkov; A. Kozlov; P. J. Kroon; C. H. Kuberg; K. Kurita; Y. Kuroki; M. J. Kweon; Y. Kwon; G. S. Kyle; R. Lacey; V. Ladygin; J. G. Lajoie; A. Lebedev; S. Leckey; D. M. Lee; S. Lee; M. J. Leitch; X. H. Li; H. Lim; A. Litvinenko; M. X. Liu; Y. Liu; C. F. Maguire; Y. I. Makdisi; A. Malakhov; V. I. Manko; Y. Mao; G. Martinez; M. D. Marx; H. Masui; F. Matathias; T. Matsumoto; P. L. McGaughey; E. Melnikov; F. Messer; Y. Miake; J. Milan; T. E. Miller; A. Milov; S. Mioduszewski; R. E. Mischke; G. C. Mishra; J. T. Mitchell; A. K. Mohanty; J. M. Moss; F. Mühlbacher; D. Mukhopadhyay; M. Muniruzzaman; J. Murata; S. Nagamiya; J. L. Nagle; T. Nakamura; B. K. Nandi; M. Nara; J. Newby; P. Nilsson; A. S. Nyanin; J. Nystrand; E. O'Brien; C. A. Ogilvie; H. Ohnishi; I. D. Ojha; K. Okada; M. Ono; V. Onuchin; A. Oskarsson; I. Otterlund; K. Oyama; K. Ozawa; D. Pal; A. P. Palounek; V. S. Pantuev; V. Papavassiliou; A. Parmar; S. F. Pate; T. Peitzmann; J.-C. Peng; V. Peresedov; C. Pinkenburg; R. P. Pisani; F. Plasil; M. L. Purschke; A. K. Purwar; J. Rak; I. Ravinovich; K. F. Read; M. Reuter; K. Reygers; V. Riabov; Y. Riabov; G. Roche; A. Romana; M. Rosati; P. Rosnet; S. S. Ryu; M. E. Sadler; N. Saito; T. Sakaguchi; M. Sakai; S. Sakai; V. Samsonov; L. Sanfratello; R. Santo; H. D. Sato; S. Sato; S. Sawada; Y. Schutz; V. Semenov; R. Seto; M. R. Shaw; T. K. Shea; T.-A. Shibata; K. Shigaki; T. Shiina; C. L. Silva; D. Silvermyr; K. S. Sim; C. P. Singh; V. Singh; M. Sivertz; A. Soldatov; R. A. Soltz; W. E. Sondheim; S. P. Sorensen; I. V. Sourikova; F. Staley; P. W. Stankus; E. Stenlund; M. Stepanov; A. Ster; S. P. Stoll; T. Sugitate; J. P. Sullivan; E. M. Takagui; A. Taketani; M. Tamai; K. H. Tanaka; Y. Tanaka; K. Tanida; M. J. Tannenbaum; P. Tarján; J. D. Tepe; T. L. Thomas; J. Tojo; H. Torii; R. S. Towell; I. Tserruya; H. Tsuruoka; S. K. Tuli; H. Tydesjö; N. Tyurin; H. W. van Hecke; J. Velkovska; M. Velkovsky; L. Villatte; A. A. Vinogradov; M. A. Volkov; E. Vznuzdaev; X. R. Wang; Y. Watanabe; S. N. White; F. K. Wohn; C. L. Woody; W. Xie; Y. Yang; A. Yanovich; S. Yokkaichi; G. R. Young; I. E. Yushmanov; W. A. Zajc; C. Zhang; S. Zhou; L. Zolin

    2003-01-01

    Transverse momentum spectra of neutral pions in the range 1

  6. 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

  7. 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\\/$c$

  8. Optimal low-thrust, three-burn orbit transfers with large plane changes

    NASA Technical Reports Server (NTRS)

    Zondervan, K. P.; Wood, L. J.; Caughey, T. K.

    1984-01-01

    Optimal low-thrust, three-burn solutions have been obtained for orbit transfers between a 28.5-degree inclined low earth orbit and a series of 63.4-degree inclined circular orbits as well as a series of 63.4-degree inclined elliptical orbits with twelve hour periods. Solutions have also been obtained for orbit transfers between 97-degree inclined orbits and a 57-degree inclined low earth orbit. Thrust to weight ratios as low as 0.02 were considered. A hybrid nonlinear programming method was used to obtain the solutions. Analysis of the optimal steering during various burns reveals a natural division of the steering strategies into two categories based on whether a burn results in a change predominantly in semi-major axis or orbit plane. The similarity of these optimal steering strategies to previously obtained simple near-optimal steering strategies is discussed.

  9. An Online Scheduling Algorithm with Advance Reservation for Large-Scale Data Transfers

    SciTech Connect

    Balman, Mehmet; Kosar, Tevfik

    2010-05-20

    Scientific applications and experimental facilities generate massive data sets that need to be transferred to remote collaborating sites for sharing, processing, and long term storage. In order to support increasingly data-intensive science, next generation research networks have been deployed to provide high-speed on-demand data access between collaborating institutions. In this paper, we present a practical model for online data scheduling in which data movement operations are scheduled in advance for end-to-end high performance transfers. In our model, data scheduler interacts with reservation managers and data transfer nodes in order to reserve available bandwidth to guarantee completion of jobs that are accepted and confirmed to satisfy preferred time constraint given by the user. Our methodology improves current systems by allowing researchers and higher level meta-schedulers to use data placement as a service where theycan plan ahead and reserve the scheduler time in advance for their data movement operations. We have implemented our algorithm and examined possible techniques for incorporation into current reservation frameworks. Performance measurements confirm that the proposed algorithm is efficient and scalable.

  10. Multi-dimensional NMR without coherence transfer: Minimizing losses in large systems

    PubMed Central

    Liu, Yizhou; Prestegard, James H.

    2011-01-01

    Most multi-dimensional solution NMR experiments connect one dimension to another using coherence transfer steps that involve evolution under scalar couplings. While experiments of this type have been a boon to biomolecular NMR the need to work on ever larger systems pushes the limits of these procedures. Spin relaxation during transfer periods for even the most efficient 15N–1H HSQC experiments can result in more than an order of magnitude loss in sensitivity for molecules in the 100 kDa range. A relatively unexploited approach to preventing signal loss is to avoid coherence transfer steps entirely. Here we describe a scheme for multi-dimensional NMR spectroscopy that relies on direct frequency encoding of a second dimension by multi-frequency decoupling during acquisition, a technique that we call MD-DIRECT. A substantial improvement in sensitivity of 15N–1H correlation spectra is illustrated with application to the 21 kDa ADP ribosylation factor (ARF) labeled with 15N in all alanine residues. Operation at 4 °C mimics observation of a 50 kDa protein at 35 °C. PMID:21835658

  11. Implicit Large-Eddy Simulation of Heat Transfer in a Cooling Channel Using Supercritical Para-Hydrogen

    NASA Astrophysics Data System (ADS)

    Chen, Z.; Hickel, S.; Adams, N. A.

    2011-08-01

    An implicit large-eddy simulation method using adaptive-local deconvolution method is used to investigate the supercritical parahydrogen flow in a cooling channel for combustion chamber in the framework of a conservative immersed interface method. The treatments of high wall temperature and no-slip wall boundary conditions are highlighted. The equation of state for parahydrogen is based on the reduced Helmholtz free energy. The thermodynamic and transport properties are modeled with high accuracy. To reduce the computational effort, the cooling channel flow with spanwise periodic boundary condition is carried out to figure out the effect of the complex curvature at Reb = 10, 200. The preliminary results show that the large spanwise rollers are produced during the development of the flow. Dean vortices are observed on both convex and concave walls according to the local flow properties. These instantaneous flow structures have large effect on the local heat transfer.

  12. 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

  13. Rydberg Atom Formation in Ultracold Plasmas: Small Energy Transfer with Large Consequences

    SciTech Connect

    Pohl, T.; Sadeghpour, H. R. [ITAMP, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States); Vrinceanu, D. [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2008-06-06

    We present extensive Monte Carlo calculations of electron-impact-induced transitions between highly excited Rydberg states and provide accurate rate coefficients. For moderate energy changes, our calculations confirm the widely applied expressions in P. Mansbach and J. Keck [Phys. Rev. 181, 275 (1969)] but reveal strong deviations at small energy transfer. Simulations of ultracold plasmas demonstrate that these corrections significantly impact the short-time dynamics of three-body Rydberg atom formation. The improved rate coefficients yield quantitative agreement with recent ultracold plasma experiments.

  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. Suppression of charged particle production at large transverse momentum in central Pb–Pb collisions at s NN = 2.76 TeV

    Microsoft Academic Search

    K. Aamodt; A. Abrahantes Quintana; D. Adamová; A. M. Adare; M. M. Aggarwal; G. Aglieri Rinella; A. G. Agocs; S. Aguilar Salazar; Z. Ahammed; N. Ahmad; A. Ahmad Masoodi; S. U. Ahn; A. Akindinov; D. Aleksandrov; B. Alessandro; R. Alfaro Molina; A. Alici; A. Alkin; E. Almaráz Aviña; T. Alt; V. Altini; S. Altinpinar; I. Altsybeev; C. Andrei; A. Andronic; V. Anguelov; C. Anson; T. Anti?i?; F. Antinori; P. Antonioli; L. Aphecetche; H. Appelshäuser; N. Arbor; S. Arcelli; A. Arend; N. Armesto; R. Arnaldi; T. Aronsson; I. C. Arsene; A. Asryan; A. Augustinus; R. Averbeck; T. C. Awes; J. Äystö; M. D. Azmi; M. Bach; A. Badalà; Y. W. Baek; S. Bagnasco; R. Bailhache; R. Bala; R. Baldini Ferroli; A. Baldisseri; A. Baldit; J. Bán; R. Barbera; F. Barile; G. G. Barnaföldi; L. S. Barnby; V. Barret; J. Bartke; M. Basile; N. Bastid; B. Bathen; G. Batigne; B. Batyunya; C. Baumann; I. G. Bearden; H. Beck; I. Belikov; F. Bellini; R. Bellwied; E. Belmont-Moreno; S. Beole; I. Berceanu; A. Bercuci; E. Berdermann; Y. Berdnikov; L. Betev; A. Bhasin; A. K. Bhati; L. Bianchi; N. Bianchi; C. Bianchin; J. Biel?ík; J. Biel?íková; A. Bilandzic; E. Biolcati; A. Blanc; F. Blanco; D. Blau; C. Blume; M. Boccioli; N. Bock; A. Bogdanov; H. Bøggild; M. Bogolyubsky; L. Boldizsár; M. Bombara; C. Bombonati; H. Borel; C. Bortolin; S. Bose; F. Bossú; M. Botje; S. Böttger; B. Boyer; P. Braun-Munzinger; L. Bravina; M. Bregant; T. Breitner; M. Broz; R. Brun; E. Bruna; G. E. Bruno; D. Budnikov; H. Buesching; O. Busch; Z. Buthelezi; D. Caffarri; X. Cai; H. Caines; E. Calvo Villar; P. Camerini; V. Canoa Roman; G. Cara Romeo; F. Carena; W. Carena; F. Carminati; A. Casanova Díaz; M. Caselle; J. Castillo Castellanos; V. Catanescu; C. Cavicchioli; P. Cerello; B. Chang; S. Chapeland; J. L. Charvet; S. Chattopadhyay; M. Cherney; C. Cheshkov; B. Cheynis; E. Chiavassa; V. Chibante Barroso; D. D. Chinellato; P. Chochula; M. Chojnacki; P. Christakoglou; C. H. Christensen; P. Christiansen; T. Chujo; C. Cicalo; L. Cifarelli; F. Cindolo; J. Cleymans; F. Coccetti; J.-P. Coffin; S. Coli; G. Conesa Balbastre; Z. Conesa del Valle; P. Constantin; G. Contin; J. G. Contreras; T. M. Cormier; Y. Corrales Morales; I. Cortés Maldonado; P. Cortese; M. R. Cosentino; F. Costa; M. E. Cotallo; E. Crescio; P. Crochet; E. Cuautle; L. Cunqueiro; G. D. Erasmo; A. Dainese; H. H. Dalsgaard; A. Danu; D. Das; I. Das; A. Dash; S. Dash; S. De; A. De Azevedo Moregula; G. O. V. de Barros; A. De Caro; G. de Cataldo; J. de Cuveland; A. De Falco; D. De Gruttola; N. De Marco; S. De Pasquale; R. De Remigis; R. de Rooij; H. Delagrange; Y. Delgado Mercado; G. Dellacasa; A. Deloff; V. Demanov; E. Dénes; A. Deppman; D. Di Bari; C. Di Giglio; S. Di Liberto; A. Di Mauro; P. Di Nezza; T. Dietel; R. Divià; Ø. Djuvsland; A. Dobrin; T. Dobrowolski; I. Domínguez; B. Dönigus; O. Dordic; O. Driga; A. K. Dubey; J. Dubuisson; L. Ducroux; P. Dupieux; A. K. Dutta Majumdar; M. R. Dutta Majumdar; D. Elia; D. Emschermann; H. Engel; H. A. Erdal; B. Espagnon; M. Estienne; S. Esumi; D. Evans; S. Evrard; G. Eyyubova; C. W. Fabjan; D. Fabris; J. Faivre; D. Falchieri; A. Fantoni; M. Fasel; R. Fearick; A. Fedunov; D. Fehlker; V. Fekete; D. Felea; G. Feofilov; A. Fernández Téllez; A. Ferretti; R. Ferretti; M. A. S. Figueredo; S. Filchagin; R. Fini; D. Finogeev; F. M. Fionda; E. M. Fiore; M. Floris; S. Foertsch; P. Foka; S. Fokin; E. Fragiacomo; M. Fragkiadakis; U. Frankenfeld; U. Fuchs; F. Furano; C. Furget; M. Fusco Girard; J. J. Gaardhøje; S. Gadrat; M. Gagliardi; A. Gago; M. Gallio; P. Ganoti; C. Garabatos; R. Gemme; J. Gerhard; M. Germain; C. Geuna; A. Gheata; M. Gheata; B. Ghidini; P. Ghosh; M. R. Girard; G. Giraudo; P. Giubellino; E. Gladysz-Dziadus; P. Glässel; R. Gomez; L. H. González-Trueba; P. González-Zamora; H. González Santos; S. Gorbunov; S. Gotovac; V. Grabski; R. Grajcarek; A. Grelli; A. Grigoras; C. Grigoras; V. Grigoriev; A. Grigoryan; S. Grigoryan; B. Grinyov; N. Grion; P. Gros; J. F. Grosse-Oetringhaus; J.-Y. Grossiord; R. Grosso; F. Guber; R. Guernane; C. Guerra Gutierrez; B. Guerzoni; K. Gulbrandsen; T. Gunji; A. Gupta; R. Gupta; H. Gutbrod; Ø. Haaland; C. Hadjidakis; M. Haiduc; H. Hamagaki; G. Hamar; J. W. Harris; M. Hartig; D. Hasch; D. Hasegan; D. Hatzifotiadou; A. Hayrapetyan; M. Heide; M. Heinz; H. Helstrup; A. Herghelegiu; C. Hernández; G. Herrera Corral; N. Herrmann; K. F. Hetland; B. Hicks; P. T. Hille; B. Hippolyte; T. Horaguchi; Y. Hori; P. Hristov; I. H?ivná?ová; M. Huang; S. Huber; T. J. Humanic; D. S. Hwang; R. Ichou; R. Ilkaev; I. Ilkiv; M. Inaba; E. Incani; G. M. Innocenti; P. G. Innocenti; M. Ippolitov; M. Irfan; C. Ivan; A. Ivanov; M. Ivanov; V. Ivanov; A. Jacho?kowski; P. M. Jacobs; L. Jancurová; S. Jangal; R. Janik; S. P. Jayarathna; S. Jena; L. Jirden; G. T. Jones; P. G. Jones

    2011-01-01

    Inclusive transverse momentum spectra of primary charged particles in Pb–Pb collisions at sNN=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 |?|0.8 and 0.3pT20 GeV\\/c are compared to the expectation in pp collisions

  16. Angular momentum transport and disk morphology in SPH simulations of galaxy formation

    E-print Network

    Tobias Kaufmann; Lucio Mayer; James Wadsley; Joachim Stadel; Ben Moore

    2006-11-21

    We perform controlled N-Body/SPH simulations of disk galaxy formation by cooling a rotating gaseous mass distribution inside equilibrium cuspy spherical and triaxial dark matter halos. We systematically study the angular momentum transport and the disk morphology as we increase the number of dark matter and gas particles from 10^4 to 10^6, and decrease the gravitational softening from 2 kpc to 50 parsecs. The angular momentum transport, disk morphology and radial profiles depend sensitively on force and mass resolution. At low resolution, similar to that used in most current cosmological simulations, the cold gas component has lost half of its initial angular momentum via different mechanisms. The angular momentum is transferred primarily to the hot halo component, by resolution-dependent hydrodynamical and gravitational torques, the latter arising from asymmetries in the mass distribution. In addition, disk-particles can lose angular momentum while they are still in the hot phase by artificial viscosity. In the central disk, particles can transfer away over 99% of their initial angular momentum due to spiral structure and/or the presence of a central bar. The strength of this transport also depends on force and mass resolution - large softening will suppress the bar instability, low mass resolution enhances the spiral structure. This complex interplay between resolution and angular momentum transfer highlights the complexity of simulations of galaxy formation even in isolated haloes. With 10^6 gas and dark matter particles, disk particles lose only 10-20% of their original angular momentum, yet we are unable to produce pure exponential profiles.

  17. "Zero-transfer" production of large-scale, flexible nanostructured film at water surface for surface enhancement Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Wang, Weihai; Zhan, Haoran; Cheng, Fansheng; Tang, Changyu; Mei, Jun; Hui, David; Liu, Yu; Zhou, Qing; Lau, Woon Ming

    2015-05-01

    Reduced complexity in production of large-scale, flexible surface enhancement Raman spectroscopy (SERS) active substrate has been implemented at the water surface, when polydimethylsiloxane (PDMS) solution having lower density than the water meets with self-assembled polystyrene (PS) nanoparticles (NPs). Through tuning its flowability, the PDMS solution could effectively wet PS NPs, wherein the PS NPs can be embedded in the PDMS during the curing process. This technical innovation saves ill-posed transfer steps as present in traditional operations which may cause damaged nanostructures, and it could be beneficial for preparing a large scale, high quality, and flexible SERS active substrate. Field tests demonstrated that the Raman signal enhancement factor could reach up to the order of ˜107 with decent repeatability less than 10%.

  18. Efficient GPU calculation of 2D-echo spectra of excitonic energy-transfer in systems with large reorganization energy

    NASA Astrophysics Data System (ADS)

    Hein, Birgit; Kreisbeck, Christoph; Kramer, Tobias; Rodriguez, Mirta

    2011-03-01

    Using the Fenna-Matthews-Olson light harvesting complex as example, we calculate the two dimensional echo spectra (2D echo) of a multi-site system coupled to phonon baths using the propagation scheme suggested by Ishizaki and Fleming in 2009 which works for large system-bath couplings. We study the anti-correlations in the shapes of the 2D spectrum peaks which are seen as evidence for exciton energy transfer. This computationally demanding calculation uses 2.6 h GPU (graphics processing unit) time compared to 2.8 weeks time on a high performance conventional CPU cluster. The efficient implementation of the exact hierarchical equations obliterates the need for approximative methods and facilitates the interpretation and comparison of theory and experiment for systems with large reorganization energies. References see www.quantumdynamics.de

  19. Hydrodynamic and mass transfer parameters in a large-scale slurry bubble column reactor with high solid loading

    SciTech Connect

    Behkish, A.; Men, Z.; Inga, J.R.; Morsi, B.I.

    1999-07-01

    The effects of pressure (P), superficial gas velocity (UG) and solid concentration (CV) on the equilibrium Solubility (C*), gas holdup (eG), volumetric gas-liquid mass transfer coefficient (kLa) and bubble size distribution for methane (CH{sub 4}) in a liquid mixture of decanes were statistically studied in a large-scale (1-ft diameter, 10-ft high) slurry bubble column reactor (SBCR). Glass beads with volumetric concentrations of 0, 7.6%, 18%, 28.4% and 36% were used. The experiments were selected following the central composite statistical design approach. The kLa values were determined using the transient physical absorption technique; the gas holdup was measured using the manometric method and the bubble size distributions were measured using the Dynamic Gas Disengagement technique (DGD). The equilibrium solubility values appeared to follow Henry's Law in the 1--15 bar range. The eG values were found to increase with superficial gas velocity and pressure due to the increase of the volume fraction of the small and large gas bubbles. The eG values, however, decreased with solid concentration due to the increase of slurry viscosity. The kLa values appeared to have the same trend as eG values indicting that the mass transfer behavior in the SBCR was mainly controlled by the gas-liquid interfacial area. Also, statistical correlations relating kLa and eG to the main process variables were proposed.

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

    E-print Network

    Fisher, Frank

    been used for gas sensors,9,17 light harvesting,18,19 surface enhanced Raman spectroscopy,8,3 There have been numerous applications sought after in nanoelectronics,4­6 chemical sensors and bio- sensors,7 a large area. Other micro/nano processing methods involving e-beam lithography18 or two

  1. Lugano, 3 December 2014 High-end connection for rapid large-volume data transfer

    E-print Network

    . In this age of "big data", the rapid exchange of data between research years ago in order to speed up the optical transmission of data. Now, 100 of data. Big data is becoming a more important issue now that large-scale research

  2. Horizontal gene transfer and nucleotide compositional anomaly in large DNA viruses

    Microsoft Academic Search

    Adam Monier; Jean-Michel Claverie; Hiroyuki Ogata

    2007-01-01

    BACKGROUND: DNA viruses have a wide range of genome sizes (5 kb up to 1.2 Mb, compared to 0.16 Mb to 1.5 Mb for obligate parasitic bacteria) that do not correlate with their virulence or the taxonomic distribution of their hosts. The reasons for such large variation are unclear. According to the traditional view of viruses as gifted \\

  3. Search for Supersymmetry in Events with Large Missing Transverse Momentum, Jets, and at Least One Tau Lepton in 7 TeV Proton-Proton Collision Data with the ATLAS Detector

    E-print Network

    Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdelalim, Ahmed Ali; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Mohammad; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Allbrooke, Benedict; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amelung, Christoph; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Andrieux, Marie-Laure; Anduaga, Xabier; Angelidakis, Stylianos; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnault, Christian; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Atkinson, Markus; Aubert, Bernard; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Avramidou, Rachel Maria; Axen, David; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagnaia, Paolo; Bahinipati, Seema; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Mark; Baker, Sarah; Balek, Petr; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barbaro Galtieri, Angela; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Barrillon, Pierre; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Begel, Michael; Behar Harpaz, Silvia; Behera, Prafulla; Beimforde, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertella, Claudia; Bertin, Antonio; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare

    2012-01-01

    A search for supersymmetry (SUSY) in events with large missing transverse momentum, jets, and at least one hadronically decaying tau lepton, with zero or one additional light lepton (e/mu), has been performed using 4.7 fb-1 of proton-proton collision data at sqrt(s) = 7 TeV recorded with the ATLAS detector at the Large Hadron Collider. No excess above the Standard Model background expectation is observed and a 95% confidence level visible cross-section upper limit for new phenomena is set. In the framework of gauge-mediated SUSY-breaking models, lower limits on the mass scale Lambda are set at 54 TeV in the regions where the stau is the next-to-lightest SUSY particle (tan(beta) > 20). These limits provide the most stringent tests to date of GMSB models in a large part of the parameter space considered.

  4. Suppression of hadrons with large transverse momentum in central Au+Au collisions at root square[s(NN)] = 130 GeV.

    PubMed

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

    2002-01-14

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

  5. Centrality Dependence of {pi}{sup 0} and {eta} Production at Large Transverse Momentum in {radical}(s{sub NN})=200 GeV d+Au Collisions

    SciTech Connect

    Adler, S. S.; Aronson, S. H.; Chujo, T.; David, G.; Desmond, E. J.; Franz, A.; Haggerty, J. S.; Harvey, M.; Johnson, B. M.; Kistenev, E.; Kroon, P. J.; Makdisi, Y. I.; Mioduszewski, S.; Mitchell, J. T.; Morrison, D. P.; O'Brien, E.; Pinkenburg, C.; Pisani, R. P.; Purschke, M. L.; Shea, T. K. [Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)] (and others)

    2007-04-27

    The dependence of transverse momentum spectra of neutral pions and {eta} mesons with p{sub T}<16 GeV/c and p{sub T}<12 GeV/c, respectively, on the centrality of the collision has been measured at midrapidity by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) in d+Au collisions at {radical}(s{sub NN})=200 GeV. The measured yields are compared to those in p+p collisions at the same {radical}(s{sub NN}) scaled by the number of underlying nucleon-nucleon collisions in d+Au. At all centralities, the yield ratios show no suppression, in contrast to the strong suppression seen for central Au+Au collisions at RHIC. Only a weak p{sub T} and centrality dependence can be observed.

  6. 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.

  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. Large-scale manufacturing of nickel aluminide transfer rolls for steel austenitizing furnaces

    Microsoft Academic Search

    V. K Sikka; M. L Santella; P Angelini; J Mengel; R Petrusha; A. P Martocci; R. I Pankiw

    2004-01-01

    This paper describes the first large-scale manufacturing of nickel aluminide IC-221M into roll bodies for the production of steel hardening furnace. One hundred and ten roll bodies were produced at Duraloy Technologies using the conventional foundry practice. Since it was the first manufacturing of this magnitude, foundry personnel were given special training with the melting of IC-221M by the Exo-Melt™

  9. Investigation on the mechanism of abnormal heat transfer of supercritical pressure water in vertically-upward tubes in the large specific heat region

    NASA Astrophysics Data System (ADS)

    Wang, J. G.; Li, H. X.; Guo, B.; Yu, S. Q.; Zhang, Y. Q.; Chen, T. K.

    2010-03-01

    The heat transfer characteristics of water at supercritical pressures in a vertically-upward internally-ribbed tube are investigated experimentally to investigate the mechanism of abnormal heat transfer of supercritical pressure water in the so-called large specific heat region. One kind optimized internally-ribbed tube is used in this study. The tube is made of SA-213T12 steel with an outer diameter of 31.8 mm and a wall thickness of 6 mm and the mean inside diameter of the tube is measured to be 17.63 mm. According to experimental data, the characteristics and mechanisms of the heat transfer enhancement and also the heat transfer deterioration of supercritical pressure water in the large specific heat region are discussed respectively. The heat transfer enhancement of the supercritical pressure water in the large specific heat region is believed to be a result of combined effect caused by the rapid variations of thermophysical properties of the supercritical pressure water in the large specific heat region, and the same is true of the heat transfer deterioration. The drastic changes in thermophysical properties near the pseudocritical points, especially the sudden rise in the specific heat of water at supercritical pressures, may result in the occurrence of the heat transfer enhancement, while the covering of the heat transfer surface by fluids lighter and hotter than the bulk fluid makes the heat transfer deteriorated eventually and explains how this lighter fluid layer forms. It is also found that the heat transfer deterioration of water at supercritical pressures is similar to the DNB (departure from nucleate boiling) at subcritical pressures in mechanism.

  10. Angular momentum exchange between coherent light and matter fields

    E-print Network

    T. P. Simula; N. Nygaard; S. X. Hu; L. A. Collins; B. I. Schneider; K. Molmer

    2007-07-25

    Full, three dimensional, time-dependent simulations are presented demonstrating the quantized transfer of angular momentum to a Bose-Einstein condensate from a laser carrying orbital angular momentum in a Laguerre-Gaussian mode. The process is described in terms of coherent Bragg scattering of atoms from a chiral optical lattice. The transfer efficiency and the angular momentum content of the output coupled vortex state are analyzed and compared with a recent experiment.

  11. 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.

  12. 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.

  13. Low thrust chemical propulsion for orbit transfer of large space structures

    NASA Technical Reports Server (NTRS)

    Shoji, J. M.

    1981-01-01

    For transporting Large Space Structures (LSS) from Low Earth Orbit (LEO) to Geosynchronous Equatorial Orbit (GEO), a variety of low thrust engine cycles have been evaluated for oxygen/hydrogen and oxygen/hydrocarbon propellants. The engine cycles included conventional propellant turbine drives (gas generator, expander, and staged-combustion cycles), turboalternator/electric motor pump drive, and fuel-cell/electric motor pump drive, as well as pressure-fed engines. The thrust chamber cooling limits and the engine cycle limits were established for a range of thrust levels. The candidate engine cycles were analyzed, screened, rated, and two engine cycle/configurations were selected for preliminary engine design. Preliminary engine designs for these two engines were formulated and engine design layouts prepared and parametric engine data generated.

  14. 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.

  15. 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.

  16. Growth, transfer, structural, optical, and electrical properties of large-size transition-metal dichalcogenide monolayer single-crystals

    NASA Astrophysics Data System (ADS)

    Yang, Zheng; Hsu, Bo; Xiao, Jiao; Poulos, George; YANG Research Group Team

    2015-03-01

    We report growth, transfer process, as well as structural, optical, and electrical properties of large-size and high-quality two-dimensional transition-metal dichalcogenide MX2 (M=Mo, W; X=S, Se) single-crystalline triangular-shape nanosheets composed of one to a few monolayers. A vapor-trapping enhanced chemical vapor deposition approach was employed for the MX2 monlayer single crystal growth. The number of layers, crystallinity, and uniformity of the as-grown MX2 were characterized and confirmed by Raman and photoluminescence measurements. The MX2 monlayer single-crystal triangles show comparable size and uniformity to the state-of-the-art results reported as of now. The optical properties of the MX2 were studied based on the analysis of the photoluminescence results. The electrical properties including resistivity, mobility, carrier type and concentration, and contact resistance of the MX2 were characterized by both three-terminal field-effect transistor and Hall effect transport measurements. The Hall bar devices were fabricated by lithography and dry-etching of the as-grown single-crystalline MX2. The transfer process of the MX2 from growth substrate (SiO2-on-Si) to various substrates was successfully demonstrated. Acknowledgement to the funding support from Ignite Award.

  17. 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.

  18. 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.

  19. 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.

  20. A transparent and transferable framework for tracking quality information in large datasets.

    PubMed

    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

  1. 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

  2. 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…

  3. 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

  4. Angular momentum transport by stochastically excited oscillations in rapidly rotating massive stars

    NASA Astrophysics Data System (ADS)

    Lee, Umin; Neiner, Coralie; Mathis, Stéphane

    2014-09-01

    We estimate the amount of angular momentum transferred by the low-frequency oscillations detected in the rapidly rotating hot Be star HD 51452. Here, we assume that the oscillations detected are stochastically excited by convective motions in the convective core of the star, that is, we treat the oscillations as forced oscillations excited by the periodic convective motions of the core fluids having the frequencies observationally determined. With the observational amplitudes of the photometric variations, we determine the oscillation amplitudes, which makes it possible to estimate the net amount of angular momentum transferred by the oscillations using the wave-meanflow interaction theory. Since we do not have any information concerning the azimuthal wavenumber m and spherical harmonic degree l for each of the oscillations, we assume that all the frequencies detected are prograde or retrograde in the observer's frame and they are all associated with a single value of m both for even modes (l = |m|) and for odd modes (l = |m| + 1). We estimate the amount of angular momentum transferred by the oscillations for |m| = 1 and 2, which are typical |m| values for Be stars, and find that the amount is large enough for a decretion disc to form around the star. Therefore, transport of angular momentum by waves stochastically excited in the core of Be stars might be responsible for the Be phenomenon.

  5. 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.

  6. Electron Scattering From High-Momentum Neutrons in Deuterium

    E-print Network

    A. V. Klimenko; S. E. Kuhn; for the CLAS collaboration

    2005-10-12

    We report results from an experiment measuring the semi-inclusive reaction $d(e,e'p_s)$ where the proton $p_s$ 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 $\\vec{p}_{s}$ and momentum transfer $Q^{2}$. 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'' $F_{2n}^{eff}$ 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 $p_{s}>400$ MeV/c, where the neutron is far off-shell, the model overestimates the value of $F_{2n}^{eff}$ 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.

  7. Large angle out of plane steady precession induced by spin-transfer with perpendicular to plane polarizer

    NASA Astrophysics Data System (ADS)

    Houssameddine, Dimitri

    2008-03-01

    The dynamics of a ferromagnetic system is characterized by a conservative precession torque, as well as a non-conservative damping torque. The damping torque is responsible for the realignment of the magnetisation with the equilibrium direction after excitation. Recently it has been shown that the damping torque can be compensated by a spin transfer torque that is due to the interaction between a spin polarized current and the local magnetization. This additional spin transfer torque can lead to auto-oscillations of the magnetization close to constant energy trajectories. The potential exploitation of such large angle auto-oscillations for tuneable microwave devices is currently driving many research efforts. For an in-plane magnetized thin film with uniaxial anisotropy, two types of constant energy trajectories exist which are commonly called in-plane precession (IPP), where the magnetization oscillates around the in-plane energy minimum, and out of plane precession (OPP) where the magnetization oscillates around the out of plane energy maximum [1]. IPP and OPP oscillations differ substantially in their dependence of frequency and amplitude as a function of current and/or applied bias field. In many experiments so far, IPP precessions have been obtained at the threshold current using in-plane magnetized spin valve structures. However, from an applications point of view it will be of interest to excite OPP oscillations since they will lead to a larger output signal than IPP oscillations. Here, we will present experimental evidence of large angle OPP oscillations using a spin torque oscillator that contains a perpendicularly magnetized polarizing layer and an in-plane magnetized analyzing layer in addition to a planar free layer [2]. We will show that OPP oscillations are induced at the threshold current for moderate current densities of 9x10^6 A/cm^2. The experimental current-field state diagram as well as the dependence of the frequency vs. current and applied bias field is in good qualitative agreement with macrospin and micromagnetic simulations. Furthermore, due to the planar analyzer, there exist IPP oscillations which allow a direct comparison of the OPP and IPP precession amplitudes. [1] A. N. Slavin, V. S. Tyberkevich Phys. Rev. B 72, 94428 (2005) [2] Houssameddine et al, Nature Materials 6, 441 (2007)

  8. Charge excitations in stripe-ordered La5/3Sr1/3NiO4 and La15/8Ba1/8CuO4: Interpretation of the anomalous momentum transfer dependence via fluorescence interferometry

    NASA Astrophysics Data System (ADS)

    Schülke, W.; Sternemann, C.

    2011-08-01

    Fluorescence interferometry (FI) makes use of the temporal and spatial coherence of absorption and re-emission process in resonant inelastic x-ray scattering (RIXS), which leads to interference terms in the RIXS cross section of a group of identical, physically equivalent, and interacting atoms. These interferences contain structural information and make RIXS site selective. The basics of FI are derived within the third-order perturbation treatment of indirect RIXS. The final relations for the FI related RIXS cross section were used to interpret the unique momentum-transfer dependence of the in-gap charge excitations observed for 214-type nickelates (La5/3Sr1/3NiO4) and cuprates (La15/8Ba1/8CuO4). By using well-known stripe models, the momentum-transfer dependence of the corresponding indirect RIXS features is traced back to interference terms in the RIXS cross section based on the principles of FI. Thus analyzing the momentum-transfer dependence of the re-emitted radiation yields information about details of the charge stripe structure.

  9. Charge-Transfer Gap of CaB6: Large Effect of Many-Body Self-Consistency

    NASA Astrophysics Data System (ADS)

    Eguiluz, Adolfo G.; Ku, Wei; Pickett, W. E.; Scalettar, R. T.

    2003-03-01

    Since the possibility that bulk CaB6 could be a semiconductor (gap 0.8eV) instead of a semimetal, was first suggested by a pseudopotential GW calculation [H. J. Tromp et. al.], the true ground state of CaB6 has been under great debate both theoretically and experimentally. A presumably more accurate all-electron GW calculation [H. Kino et. al.] reported a semimetallic band-crossing, similar to that in the local-density calculation, and thus agrees with original picture from transport and other Fermi-topology measurements. On the other hand, recent angle-resolved photoemission measurements [J. D. Denlinger et. al.] provide strong evidence indicating a 1.15 eV charge-transfer gap. We demonstrate that a state-of-the-art conserving, all-electron GW calculation leads to a large gap that agrees well with photoemission data. Most surprisingly, unlike in previously studied semiconductors, it is the many-body self-consistency, which enforces the conservation laws, that is mainly responsible for opening the gap. Such physics is missing in all existing calculations.

  10. 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.

  11. Time Dependent 3D Large Eddy Simulation of a DC Non-Transferred Arc Plasma Spraying Torch with Particle Injection

    Microsoft Academic Search

    E. Ghedini; V. Colombo

    2007-01-01

    Summary form only given. The aim of this work is to investigate by means of a 3D time-dependent numerical model the plasma flow and heat transfer inside a DC non-transferred arc plasma torch operating at atmospheric pressure, using a customized version of the CFD commercial code FLUENTcopy. Unsteady flow and heat transfer equations are solved with coupled electromagnetic ones, for

  12. About the TATB assumption: effect of charge reversal on transfer of large spherical ions from aqueous to non-aqueous solvents and on their interfacial behaviour

    Microsoft Academic Search

    R. Schurhammer; G. Wipff

    2000-01-01

    We present a molecular dynamics study of the solvation properties of large spherical ions S+ and S? of same size, in water, chloroform and acetonitrile solutions, and at a water–chloroform interface. According to the “extrathermodynamic” TATB hypothesis, such ions have identical free energies of transfer from water to any solvent. We find that this is not the case, because S?

  13. Investigating the installed real power transfer capability of a large scale power system under a proposed multiarea interchange schedule using CPFLOW

    Microsoft Academic Search

    Alexander J. Flueck; Hsiao-Dong Chiang; Kirit S. Shah

    1996-01-01

    This paper studies the real power transfer capability, under multiarea interchange schedules, of large scale power systems. An improved version of the simulation tool CPFLOW computes a series of operating points of the power system under a proposed multiarea interchange schedule. The steady-state feasibility of the computed points is based on typical power system operating criteria. CPFLOW traces the curves

  14. Interface shape, heat transfer and fluid flow in the floating zone growth of large silicon crystals with the needle-eye technique

    Microsoft Academic Search

    Alfred Mühlbauer; Andris Muiznieks; Janis Virbulis; Anke Lüdge; Helge Riemann

    1995-01-01

    A computer simulation is carried out to study the interface shape, heat transfer and fluid flow in the floating zone (FZ) growth of large (> 100 mm) Si crystals with the needle-eye technique and with feed\\/crystal rotation. Natural convection, thermocapillary convection, electromagnetic (EM) forces and rotation in the melt are considered. The unknown shape of the molten zone is calculated

  15. The numerical experiments on applicating geostrophic momentum approximation to the baroclinic and non-neutral PBL

    NASA Astrophysics Data System (ADS)

    Zhao, Ming

    1988-09-01

    In this paper, Wu and Blumen’s boundary layer geostrophic momentum approximation model (Wu and Blumen, 1982) is applied to baroclinic and non-neutral PBL, the motion equations for the PBL under the geostrophic momentum approximation are solved, in which the eddy transfer coefficient is a function of the distributions of the wind and temperature. The results are compared with those in barotropic and neutral conditions with the geostrophic momentum approximation. It is found that in the baroclinic condition, the wind distribution has both the characteristics of a steady, homogeneous and baroclinic PBL and those caused by the geostrophic momentum approximation. Those in non-neutral conditions show that they retain the intrinsic characteristics for the wind in non-neutral PBL, at the same time, the effects of the large-scale advection and local variation are also included. We can predict the wind in the non-neutral and baroclinic PBL by use of the geostrophic momentum approximation when the temporal and spatial distributions of the geostrophic wind, as well as the potential temperatures and their variation rates at the upper and lower boundary of the PBL are given by large-scale model. Finally, the model is extended to the case over sea surface.

  16. Uncertainty Relations for Angular Momentum

    E-print Network

    Lars Dammeier; Rene Schwonnek; Reinhard F. Werner

    2015-04-30

    In this work we study various notions of uncertainty for angular momentum in the spin-s representation of SU(2). We characterize the "uncertainty regions" given by all vectors, whose components are the variances of the three angular momentum components. A basic feature of this set is a lower bound for the sum of the three variances. We give a method for obtaining optimal lower bounds for uncertainty regions for general operator triples, and evaluate these for small s. Further lower bounds are derived by generalizing the technique by which Robertson obtained his state-dependent lower bound. These are optimal for large s, since they are saturated by states taken from the Holstein-Primakoff approximation. We show that, for all s, all variances are consistent with the so-called vector model, i.e., they can also be realized by a classical probability measure on a sphere of radius sqrt(s(s+1)). Entropic uncertainty relations can be discussed similarly, but are minimized by quite different states from the variance minimizing ones for small s. For large s the Maassen-Uffink bound becomes sharp, again being saturated by Holstein-Primakoff states. Measurement uncertainty, as recently discussed by Busch, Lahti and Werner for position and momentum, is introduced and a generalized observable (POVM) which minimizes the worst case measurement uncertainty of all angular momentum components is explicitly determined. Its outputs are angular momentum vectors whose absolute value r(s) depends only on s. The function r is determined explicitly, and r(s)/s approaches 1 from below.

  17. 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.

  18. 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.

  19. 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

    Aad, Georges; Abdallah, Jalal; Abdel Khalek, Samah; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; 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; 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; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Allbrooke, Benedict; Allison, Lee John; Allport, Phillip; Almond, John; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; 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; Anduaga, Xabier; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; 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; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baas, Alessandra; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Backus Mayes, John; Badescu, Elisabeta; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Balek, Petr; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; 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; Bartsch, Valeria; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batley, Richard; Battaglia, Marco; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Katharina; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Bernard, Clare; Bernat, Pauline; 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, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Black, Curtis; Black, James

    2014-01-01

    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 20.3 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 fra...

  20. Pyrosequencing-based comparative genome analysis of the nosocomial pathogen Enterococcus faecium and identification of a large transferable pathogenicity island

    PubMed Central

    2010-01-01

    Background The Gram-positive bacterium Enterococcus faecium is an important cause of nosocomial infections in immunocompromized patients. Results We present a pyrosequencing-based comparative genome analysis of seven E. faecium strains that were isolated from various sources. In the genomes of clinical isolates several antibiotic resistance genes were identified, including the vanA transposon that confers resistance to vancomycin in two strains. A functional comparison between E. faecium and the related opportunistic pathogen E. faecalis based on differences in the presence of protein families, revealed divergence in plant carbohydrate metabolic pathways and oxidative stress defense mechanisms. The E. faecium pan-genome was estimated to be essentially unlimited in size, indicating that E. faecium can efficiently acquire and incorporate exogenous DNA in its gene pool. One of the most prominent sources of genomic diversity consists of bacteriophages that have integrated in the genome. The CRISPR-Cas system, which contributes to immunity against bacteriophage infection in prokaryotes, is not present in the sequenced strains. Three sequenced isolates carry the esp gene, which is involved in urinary tract infections and biofilm formation. The esp gene is located on a large pathogenicity island (PAI), which is between 64 and 104 kb in size. Conjugation experiments showed that the entire esp PAI can be transferred horizontally and inserts in a site-specific manner. Conclusions Genes involved in environmental persistence, colonization and virulence can easily be aquired by E. faecium. This will make the development of successful treatment strategies targeted against this organism a challenge for years to come. PMID:20398277

  1. "Some Like it Hot” - Evidence for the Shrinking Orbit of the 2.2-day Transiting Hot Jupiter Exoplanet HD 189733b - Evidence of Transfer of Planet Orbital Momentum to its Host Star

    NASA Astrophysics Data System (ADS)

    Santapaga, Thomas; Guinan, E. F.; Ballouz, R.; Engle, S. G.; Dewarf, L.

    2011-01-01

    HD189733A is a K2V star that has attracted much attention because it hosts a transiting, hot Jupiter-exoplanet. HD189733b has one of the shortest known orbital-periods (P = 2.22-days) and is only 0.031AU from its host star (Buchy et al. 2005). Based on measurements of the K2V star's P(rot) from starspot-modulations of 12-d, coronal Lx 1028 ergs/s, and chromospheric Ca II-HK emission, indicate an age 0.6 -1.0 Gyr - inferred from our rotation-age-activity relations. However, this age is discrepant with an older-age inferred from the star's low Lithium-abundance ( 1/10 Solar.). However, the age-rotation-activity determination assumes no tidal-effects from close companions- such as close planet. Recently Gaspar et al. (2006) discovered a dM4 companion star (HD 189733 B: 12'' distance to the K-dwarf). X MM-Newton observations of the HD 189733 A&B carried out recently by Pilliteri et al. (2010), surprisingly revealed that HD 189733B shows no X-ray emission, with an upper limit of 9*1026 ergs/s. Using activity-age relationships for dM-stars, we expected a Lx of an order of magnitude higher for age <1.0 Ga. This apparent discrepancy can be resolved by the supposition that the K2V-star has been spun-up by its nearby planetary companion, and that its age determined from activity-rotation relationships is invalid. This supposition is supported by the recent photometry by the Kepler for 300+ exoplanet candidate systems discovered thus far (Borucki et al. 2010). The analysis these data have reveal that tidal locking between the planet and host star has occurred for a significant number of exoplanet with short orbital periods. We explain the fast rotation of the K2 star via the transfer of the planet's orbital angular momentum to the star via tidal interactions. The significance of these finding with respect to the evolution of planetary systems is discussed. This work is partially supported by NSF/RUI grant AST-1009903.

  2. 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.

  3. 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

  4. 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.

  5. Angular Momentum Operator Identities G I. Orbital Angular Momentum

    E-print Network

    Simons, Jack

    Angular Momentum Operator Identities G I. Orbital Angular Momentum A particle moving with momentum p at a position r relative to some coordinate origin has so-called orbital angular momentum equal to L = r x p . The three components of this angular momentum vector in a cartesian coordinate system

  6. Experimental study of gas turbine blade film cooling and internal turbulated heat transfer at large Reynolds numbers 

    E-print Network

    Mhetras, Shantanu

    2009-06-02

    superposition of effectiveness data from individual rows are comparable with that from full coverage film cooling. Internal heat transfer measurements are also performed in a high aspect ratio channel and from jet array impingement on a turbulated target wall...

  7. The effects of Reynolds number, rotor incidence angle and surface roughness on the heat transfer distribution in a large-scale turbine rotor passage

    NASA Astrophysics Data System (ADS)

    Blair, M. F.

    1991-11-01

    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.

  8. 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

  9. Fragment separator momentum compression schemes.

    SciTech Connect

    Bandura, L.; Erdelyi, B.; Hausmann, M.; Kubo, T.; Nolen, J.; Portillo, M.; Sherrill, B.M. (Physics); (MSU); (Northern Illinois Univ.); (RIKEN)

    2011-07-21

    We present a scheme to use a fragment separator and profiled energy degraders to transfer longitudinal phase space into transverse phase space while maintaining achromatic beam transport. The first order beam optics theory of the method is presented and the consequent enlargement of the transverse phase space is discussed. An interesting consequence of the technique is that the first order mass resolving power of the system is determined by the first dispersive section up to the energy degrader, independent of whether or not momentum compression is used. The fragment separator at the Facility for Rare Isotope Beams is a specific application of this technique and is described along with simulations by the code COSY INFINITY.

  10. Confining potential in momentum space

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Kahana, David E.; Maung, Khin Maung

    1992-01-01

    A method is presented for the solution in momentum space of the bound state problem with a linear potential in r space. The potential is unbounded at large r leading to a singularity at small q. The singularity is integrable, when regulated by exponentially screening the r-space potential, and is removed by a subtraction technique. The limit of zero screening is taken analytically, and the numerical solution of the subtracted integral equation gives eigenvalues and wave functions in good agreement with position space calculations.

  11. 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.).

  12. 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

    initiated by the exper- imental discovery of broad peaks in the continuum region of the '2C('60, o.) reaction. ' Since the excitation energies of those peaks were closely correlated to energies of the ' C+' C intermediate, or nuclear molecular resonances... of a ONe nucleus has a strong n-'60 clustering strength. Therefore, a Ne induced reaction might have appreciable amount of a direct '60 transfer process. The ' C+' 0 system is generally accepted to have intermediate-structure resonances and has been...

  13. a Study of the Role of Large-Amplitude Motions in Unimolecular Energy Transfer Using Molecular Beam Optothermal Spectroscopy

    Microsoft Academic Search

    Carl Cameron Miller

    1995-01-01

    The role of molecular structure in energy transfer reactions in the ground and excited electronic states was explored using optothermal spectroscopy. In the ground state, the relationship between intramolecular van der Waals interactions and vibrational mode coupling was explored in a homologous series of disubstituted ethanes, including Gg^' -2-fluoroethanol, g-1,2-difluoroethane, g-1-chloro-2-fluoroethane, t-1-chloro-2-fluoroethane, and 1,1,2-trifluoroethane. This series of substituted ethanes varies

  14. Planetary Migration to Large Radii

    E-print Network

    R. G. Martin; S. H. Lubow; J. E. Pringle; M C. Wyatt

    2007-04-25

    There is evidence for the existence of massive planets at orbital radii of several hundred AU from their parent stars where the timescale for planet formation by core accretion is longer than the disc lifetime. These planets could have formed close to their star and then migrated outwards. We consider how the transfer of angular momentum by viscous disc interactions from a massive inner planet could cause significant outward migration of a smaller outer planet. We find that it is in principle possible for planets to migrate to large radii. We note, however, a number of effects which may render the process somewhat problematic.

  15. Energy-Momentum Distribution:

    NASA Astrophysics Data System (ADS)

    Sharif, M.; Fatima, Tasnim

    This paper is aimed to elaborate the problem of energy-momentum in general relativity. In this connection, we use the prescriptions of Einstein, Landau-Lifshitz, Papapetrou and Möller to compute the energy-momentum densities for two exact solutions of Einstein field equations. The space-times under consideration are the nonnull Einstein-Maxwell solutions and the singularity-free cosmological model. The electromagnetic generalization of the Gödel solution and the Gödel metric become special cases of the nonnull Einstein-Maxwell solutions. It turns out that these prescriptions do not provide consistent results for any of these space-times. These inconsistent results verify the well-known proposal that the idea of localization does not follow the lines of pseudotensorial construction but instead follows from the energy-momentum tensor itself. These differences can also be understood with the help of the Hamiltonian approach.

  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. Unveiling Angular Momentum

    NASA Astrophysics Data System (ADS)

    Robinson, Stephen

    2015-03-01

    Angular momentum is a notoriously difficult concept to grasp. Visualization often requires three-dimensional pictures of vectors pointing in seemingly arbitrary directions. A simple student-run laboratory experiment coupled with intuitive explanations by an instructor can clear up some of the inherent ambiguity of rotational motion. Specifically, the precessional period of a suspended spinning bicycle wheel can be related to the spinning frequency through a simple algebraic expression. An explanation of this precession apart from the concept of angular momentum will be given.

  18. 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 $v_2(p_T)$.

  19. Mars - Satellite origin and angular momentum

    NASA Technical Reports Server (NTRS)

    Hartmann, W. K.; Davis, D. R.; Chapman, C. R.; Soter, S.; Greenberg, R.

    1975-01-01

    The origin of Phobos and Deimos is considered with a view to accounting for the existence of very small satellites with circular orbits in the Martian equatorial plane, and simultaneously for the suspected angular momentum deficiency of the Mars system. All models considered failed to satisfy at least one requirement, and the problem is considered more puzzling than is at first apparent. The Martian angular momentum deficiency, if physically significant, may be unrelated to the present satellites' origin, but might relate to a large ancient satellite, long ago destroyed. Accretion onto Mars of large amounts of asteroidal dust brought in by Poynting-Robertson drag may have some bearing on the angular momentum problem.

  20. Studies of wall shear and mass transfer in a large scale model of neonatal high-frequency jet ventilation.

    PubMed

    Muller, W J; Gerjarusek, S; Scherer, P W

    1990-01-01

    The problem of endotracheal erosion associated with neonatal high-frequency jet ventilation (HFJV) is investigated through measurement of air velocity profiles in a scaled up model of the system. Fluid mechanical scaling principles are applied in order to construct a model within which velocity profiles are measured by hot-wire anemometry. The effects of two different jet geometries are investigated. Velocity gradients measured near the tracheal wall are used to measure the shear stresses caused by the jet flow on the wall. The Chilton-Colburn analogy between the transport of momentum and mass is applied to investigate tracheal drying caused by the high shear flow. Shear forces are seen to be more than two times higher for jets located near the endotracheal tube wall than for those located axisymmetrically in the center of the tube. Since water vapor fluxes are dependent on these shears, they are also higher for the asymmetric case. Fluxes are shown to be greatly dependent on the temperature and relative humidity of the inspired gas. Water from the tracheal surface may be depleted within one second if inspired gases are inadequately heated and humidified. It is recommended that the design of neonatal HFJV devices include delivery of heated (near body temperature), humidified (as close to 100% humidity as possible) gases through an axisymmetric jet to best avoid the problem of endotracheal erosion. PMID:2306032

  1. 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.

  2. Interface between path and orbital angular momentum entanglement for high-dimensional photonic quantum information

    NASA Astrophysics Data System (ADS)

    Fickler, Robert; Lapkiewicz, Radek; Huber, Marcus; Lavery, Martin P. J.; Padgett, Miles J.; Zeilinger, Anton

    2014-07-01

    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.

  3. Mouse microsomal triglyceride transfer protein large subunit: cDNA cloning, tissue-specific expression, and chromosomal localization

    SciTech Connect

    Nakamuta, Makoto; Chang, Benny Hung-Junn; Hoogeveen, R. [Baylor College of Medicine, Houston, TX (United States)] [and others] [Baylor College of Medicine, Houston, TX (United States); and others

    1996-04-15

    Microsomal triglyceride transfer protein (MTP) catalyzes the transfer of triglyceride, cholesteryl ester, and phospholipid between membranes. It is essential for the secretion of apolipoprotein B from the cell. Mutations in MTP are a major cause of abetalipoproteinemia. The mouse is a popular animal model for lipoprotein metabolism. We have cloned and sequenced mouse MTP cDNA. The DNA-deduced amino acid sequence indicates that mouse protein shows 93, 86, and 83% sequence indicates that mouse MTP contains 894 amino acids; the mouse protein shows 93, 86, and 83% sequence identity to the hamster, human, and bovine sequences, respectively. Northern blot analysis indicates that mouse MTP mRNA is expressed at high levels in the small intestine and at substantially lower levels in the liver and that it is not detectable in six other tissues examined. The mouse MTP gene has been localized to the distal region of chromosome 3 by Southern blots of interspecific backcross panels using progeny derived from matings of (C57BL/6J x SPRET/Ei)F1 x SPRET/Ei. Comparison of MTP sequences from human, bovine, hamster, and mouse indicates that the C-terminal region of MTP is better conserved than its N-terminal region. 21 refs., 2 figs.

  4. Gas mass transfer for stratified flows

    SciTech Connect

    Duffey, R.B. [Brookhaven National Lab., Upton, NY (United States); Hughes, E.D. [CSA Inc., Idaho Falls, ID (United States)

    1995-07-01

    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 equilibrum 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 geophysical and chemical engineering literature.

  5. Gas mass transfer for stratified flows

    SciTech Connect

    Duffey, R.B. [Brookhaven National Lab., Upton, NY (United States); Hughes, E.D. [CSA, Inc., Idaho Falls, ID (United States)

    1995-06-01

    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.

  6. 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.

  7. 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,…

  8. Noise-Immune Conjugate Large-Area Atom Interferometers

    NASA Astrophysics Data System (ADS)

    Chiow, Sheng-Wey; Herrmann, Sven; Chu, Steven; Müller, Holger

    2009-07-01

    We present a pair of simultaneous conjugate Ramsey-Bordé atom interferometers using large (20?k)-momentum transfer beam splitters, where ?k is the photon momentum. Simultaneous operation allows for common-mode rejection of vibrational noise. This allows us to surpass the enclosed space-time area of previous interferometers with a splitting of 20?k by a factor of 2500. Using a splitting of 10?k, we demonstrate a 3.4 ppb resolution in the measurement of the fine structure constant. Examples for applications in tests of fundamental laws of physics are given.

  9. Advanced Heat Transfer Studies in Superfluid Helium for Large-scale High-yield Production of Superconducting Radio Frequency Cavities

    E-print Network

    Peters, Benedikt J; Schirm, Karl-Martin; Koettig, Torsten

    Oscillating Superleak Transducers (OSTs) can be used to localize quenches in superconducting radio frequency cavities. In the presented work the occurring thermal effects during such events are investigated both theoretically and experimentally. In the theoretical part the entire heat transfer process from the heat generation to the detection is covered. The experimental part focuses on the effects in superfluid helium. Previous publications observed the detection of an OST signal that was faster than the second sound velocity. This fast propagation could be verified in dedicated small scale experiments. Resistors were used to simulate the quench spots under controlled conditions. The three dimensional propagation of second sound was linked to OST signals for the first time, which improves the understanding of the OST signal and allows to gather information about the heating pulse. Additionally, OSTs were used as a tool for quench localisation on a real size cavity. Their sensitivity as well as the time resol...

  10. 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.

  11. PHYSICAL REVIEW E 84, 011804 (2011) Ideal linear-chain polymers with fixed angular momentum

    E-print Network

    Deutsch, Josh

    2011-01-01

    PHYSICAL REVIEW E 84, 011804 (2011) Ideal linear-chain polymers with fixed angular momentum Matthew noninteracting polymer chain with a large number of monomers is considered with fixed angular momentum is then compared to simulations done with a large number of noninteracting rigid links at fixed angular momentum

  12. Gene Transfer of Low Levels of ?-Glucuronidase Corrects Hepatic Lysosomal Storage in a Large Animal Model of Mucopolysaccharidosis VII

    Microsoft Academic Search

    John H. Wolfe; Mark S. Sands; Noam Harel; Margaret A. Weil; Micheal K. Parente; Aracelis C. Polesky; John J. Reilly; Christopher Hasson; Staci Weimelt; Mark E. Haskins

    2000-01-01

    Gene therapy has been at least partially effective in several mouse disease models, but treatment of large mammals has been more difficult to achieve. One major limitation is that only low levels of expression of the corrective gene are often maintained in vivo. In a mouse model of the lysosomal storage disease mucopolysaccharidosis (MPS) type VII (Sly disease) with a

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

    E-print Network

    Cummer, Steven A.

    in a mesoscale convective system Gaopeng Lu,1 Steven A. Cummer,1 Jingbo Li,1 Feng Han,1 Richard J. Blakeslee,2 positive cloud-to-ground (+CG) strokes in a mesoscale convective system. Although no high altitude images of large-charge-moment positive lightning strokes in a mesoscale convective system, Geophys. Res. Lett., 36

  14. Estimating Energy-Momentum and Angular Momentum Near Null Infinity

    E-print Network

    Adam D. Helfer

    2010-02-19

    The energy-momentum and angular momentum contained in a spacelike two-surface of spherical topology are estimated by joining the two-surface to null infinity via an approximate no-incoming-radiation condition. The result is a set of gauge-invariant formulas for energy-momentum and angular momentum which should be applicable to much numerical work; it also gives estimates of the finite-size effects.

  15. Estimating energy-momentum and angular momentum near null infinity

    SciTech Connect

    Helfer, Adam D. [Department of Mathematics, University of Missouri, Columbia, Missouri 65211 (United States)

    2010-04-15

    The energy-momentum and angular momentum contained in a spacelike two-surface of spherical topology are estimated by joining the two-surface to null infinity via an approximate no-incoming-radiation condition. The result is a set of gauge-invariant formulas for energy-momentum and angular momentum which should be applicable to much numerical work; it also gives estimates of the finite-size effects.

  16. Momentum-energy change in elastic relativistic binary collisions

    NASA Astrophysics Data System (ADS)

    Menon, V. J.; Dubey, R. K.; Mishra, M.; Patra, B. K.

    2009-05-01

    We consider a relativistic elastic collision between a projectile of momentum p with a target atom of momentum k in a general inertial frame. We employ one space plus one time Minkowski geometry and calculate the momentum transfer vector q? suffered by the projectile calculated via a Lorentz transformation to the barycentric frame and then eliminate k. The resulting expression for q? reproduces several known cases, its algebraic behavior can be interpreted physically, and it leads to a simple understanding of the relativistic equipartition law.

  17. Momentum effects in steady nucleate pool boiling during microgravity.

    PubMed

    Merte, Herman

    2004-11-01

    Pool boiling experiments were conducted in microgravity on five space shuttle flights, using a flat plate heater consisting of a semitransparent thin gold film deposited on a quartz substrate that also acted as a resistance thermometer. The test fluid was R-113, and the vapor bubble behavior at the heater surface was photographed from beneath as well as from the side. Each flight consisted of a matrix of three levels of heat flux and three levels of subcooling. In 26 of the total of 45 experiments conditions of steady-state pool boiling were achieved under certain combinations of heat flux and liquid subcooling. In many of the 26 cases, it was observed from the 16-mm movie films that a large vapor bubble formed, remaining slightly removed from the heater surface, and that subsequent vapor bubbles nucleate and grow on the heater surface. Coalescence occurs upon making contact with the large bubble, which thus acts as a vapor reservoir. Recently, measurements of the frequencies and sizes of the small vapor bubbles as they coalesced with the large bubble permitted computation of the associated momentum transfer. The transient forces obtained are presented here. Where these arise from the conversion of the surface energy in the small vapor bubble to kinetic energy acting away from the solid heater surface, they counter the Marangoni convection due to the temperature gradients normal to the heater surface. This Marangoni convection would otherwise impel the large vapor bubble toward the heater surface and result in dryout and unsteady heat transfer. PMID:15644357

  18. Nuclear momentum distribution and potential energy surface in hexagonal ice

    Microsoft Academic Search

    Lin Lin; Joseph Morrone; Roberto Car; Michele Parrinello

    2011-01-01

    The proton momentum distribution in ice Ih has been recently measured by deep inelastic neutron scattering and calculated from open path integral Car-Parrinello simulation. Here we report a detailed investigation of the relation between momentum distribution and potential energy surface based on both experiment and simulation results. The potential experienced by the proton is largely harmonic and characterized by 3

  19. Grain and grain-boundary control of the transfer characteristics of large-grain polycrystalline silicon thin-film transistors

    Microsoft Academic Search

    F. V Farmakis; J Brini; G Kamarinos; C. T Angelis; C. A Dimitriadis; M Miyasaka; T Ouisse

    2000-01-01

    Thin-film transistors (TFTs), fabricated on solid-phase-crystallized polycrystalline silicon (polysilicon) films subjected to laser annealing, were studied. For the resulting large-grain polysilicon TFTs, a model is proposed that takes into account two well-distinguished regions within the channel of the transistor: the intra-grain region and the grain boundaries. By using this model, we found that the extracted on-voltage is mainly grain-boundary dependent

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

    Microsoft Academic Search

    Artem L. Ponomarev; David Brenner; Lynn R. Hlatky; Rainer K. Sachs

    2000-01-01

    DNA double-strand breaks (DSBs) produced by densely ionizing radiation are not located randomly in the genome: recent data\\u000a indicate DSB clustering along chromosomes. Stochastic DSB clustering at large scales, from >100 Mbp down to <0.01 Mbp, is\\u000a modeled using computer simulations and analytic equations. A random-walk, coarse-grained polymer model for chromatin is combined\\u000a with a simple track structure model in

  1. Observation of a large electric dipole moment produced in electron-transfer collisions of H\\/sup +\\/ on He

    Microsoft Academic Search

    C. C. Havener; W. B. Westerveld; J. S. Risley; N. H. Tolk; J. C. Tully

    1982-01-01

    The measured intensity and polarization of Balmer-alpha radiation resulting from (40--80)-keV collisions of H\\/sup +\\/ on He exhibited a strong dependence with electric fields applied axially along the beam direction. With use of a density matrix formalism the collisionally produced electric dipole moment for the n = 3 state was found to be large, reaching 4.4eaâ at the lowest collision

  2. A large-scale allosteric transition in cytochrome P450 3A4 revealed by luminescence resonance energy transfer (LRET).

    PubMed

    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

  3. 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.

  4. Electron momentum distribution in underdoped cuprates

    NASA Astrophysics Data System (ADS)

    Ramšak, A.; Sega, I.; Prelovšek, P.

    2000-02-01

    We investigate the electron momentum distribution function (EMD) in a weakly doped two-dimensional quantum antiferromagnet (AFM) as described by the t-J model. Our analytical results for a single hole in an AFM based on the self-consistent Born approximation (SCBA) indicate an anomalous momentum dependence of EMD showing ``hole pockets'' coexisting with a signature of an emerging large Fermi surface. The position of the incipient Fermi surface and the structure of the EMD is determined by the momentum of the ground state. Our analysis shows that this result remains robust in the presence of next-nearest neighbor hopping terms in the model. Exact diagonalization results for small clusters are with the SCBA reproduced quantitatively.

  5. Observation of a large electric dipole moment produced in electron-transfer collisions of H/sup +/ on He

    SciTech Connect

    Havener, C.C.; Westerveld, W.B.; Risley, J.S.; Tolk, N.H.; Tully, J.C.

    1982-04-05

    The measured intensity and polarization of Balmer-alpha radiation resulting from (40--80)-keV collisions of H/sup +/ on He exhibited a strong dependence with electric fields applied axially along the beam direction. With use of a density matrix formalism the collisionally produced electric dipole moment for the n = 3 state was found to be large, reaching 4.4ea/sub 0/ at the lowest collision energy. The center of the electron cloud distribution was found to lag behind the proton.

  6. Effects of a Momentum Driven Stellar Wind on the Surrounding ISM

    NASA Astrophysics Data System (ADS)

    Ngoumou, Judith; Hubber, David Anthony; Dale, James E.; Burkert, Andreas

    Massive stars shape the surrounding ISM by emitting ionizing photons and ejecting material through stellar winds. We study the impact of the transfer of momentum from the wind of a massive star on the surrounding neutral or ionized material. We use the Smoothed Particle Hydrodynamics (SPH) code SEREN [3] including a newly implemented HEALPix-based momentum conserving wind scheme. The transfer of momentum from a wind onto the cold surrounding gas drives the expansion of a shock front, sweeping up the neutral material into a dense shell. In contrast, we find the momentum driven wind to have only little direct effect on the warm ionized gas.

  7. Large volume injection of water in gas chromatography–mass spectrometry using the Through Oven Transfer Adsorption Desorption interface: Application to multiresidue analysis of pesticides.

    PubMed

    Toledano, Rosa M; Cortés, Jose M; Andini, Juan C; Villén, Jesús; Vázquez, Ana

    2010-07-01

    In the present work, the potential of the Through Oven Transfer Adsorption Desorption (TOTAD) interface for the large volume injection (LVI) of aqueous samples in gas chromatography (GC) using a mass spectrometry (MS) detector is demonstrated. To this end, a new method for the determination of pesticides in water is presented, being the first developed method in which injection of large amounts of polar solvents using the TOTAD interface and an MS detector are combined, is applied to the determination of pesticides in water. Water samples, as large as 5 ml, were directly injected into a capillary GC. No sample pre-treatment step other than simple filtration was needed. The TOTAD interface allows the introduction of several millilitres of water, while maintaining good chromatographic characteristics. The water is almost entirely eliminated, so that LVI of aqueous samples and an MS detector can be used without problems. Organophosphorus, organochlorine, and triazine pesticides were determined in one run. Calibration curves were linear in the range tested and the sensitivity achieved injecting 5 ml of water sample was sufficient for most of the target pesticides but not for all of them. Sensitivity of the analysis can be improved by increasing the sample volume. No variability was observed in the retention times and relative standard deviations from absolute peak areas were good, considering that they corresponded to the overall analysis. The method was applied to the analysis of pesticide residues in real water samples. PMID:20605155

  8. 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

  9. Photophysical properties of pyrrolobenzenes with different linking and substitution pattern: The transition between charge transfer states with large (MICT) and small (TICT) resonance interaction

    NASA Astrophysics Data System (ADS)

    Murali, S.; Changenet-Barret, P.; Ley, C.; Plaza, P.; Rettig, W.; Martin, M. M.; Lapouyade, R.

    2005-08-01

    Pyrrolobenzenes, with different linking and substitution patterns, 2'-(4-cyanophenyl)-methylpyrrole (MP2-BN) and 2'-(2,5-cyanophenyl)-methylpyrrole (MP2-B25CN), are investigated by steady-state and time-resolved UV-Vis spectroscopy and compared to the parent compound N-pyrrolobenzonitrile (PBN). Both the electron donor-acceptor linking sites and the strength of the electron acceptor moiety are found to influence the emission characteristics of these compounds. The large radiative rate constant of MP2-BN indicates an allowed emission due to mesomeric interaction between the donor and acceptor moieties (MICT), whereas in the case of PBN and MP2-B25CN, the reduced radiative rate constant indicates a forbidden emission from a twisted intramolecular charge transfer (TICT) state.

  10. A model for the devolatilization of a coal particle sufficiently large to be controlled by heat transfer

    SciTech Connect

    Chern, Jyuung-Shiauu; Hayhurst, Allan N. [Department of Chemical Engineering, University of Cambridge, Pembroke Street, Cambridge CB2 3RA (United Kingdom)

    2006-08-15

    This study follows previous experimental work showing that the shrinking-core model applies to the pyrolysis (i.e., heating in the absence of oxygen) of particles (diam.{approx}14 mm) of a bituminous coal or a lignite in a fluidized bed at 700-950 {sup o}C. These experimental facts are in accord with the production of volatile matter being endothermic and not thermoneutral, as often assumed. Also, the rate at which volatile matter is produced in the presence of oxygen (i.e., devolatilization) or in its absence (pyrolysis) is demonstrated here to be controlled not at all by mass transfer, but by heat conduction to a moving reaction front inside a coal particle, provided its diameter exceeds {approx}3 mm. The resulting steady-state model of devolatilization indicates that six dimensionless groups are required to describe the rate of(I)coal->char+volatile matter for a nonfragmenting and nonswelling coal. This reaction occurs for a total time of c{sub 1}r{sub 0}+c{sub 2}r{sub 0}{sup 2} for a coal of radius r{sub 0}. Experimental measurements of the times for pyrolysis in a bed of hot sand fluidized by N{sub 2} indicate this dependence on r{sub 0} holds much better than the usually accepted one of ar{sub 0}{sup n}. The measurements also indicate that the enthalpy change of reaction (I) is 9.4{+-}4.0 MJ/(kg of volatile matter) and the thermal conductivity of char is 1.2{+-}0.5 Wm{sup -1}K{sup -1}. In addition, it was deduced that reaction (I) occurs at {approx}500 K and that {eta} (of the heat released by burning the volatile material, a fraction {eta} is fed back to a parent coal particle devolatilizing in a bed fluidized by, e.g., air) is less than unity. These numerical considerations enable the model of devolatilization to be simplified; it turns out that a heated particle's core of virgin coal shrinks mostly with a constant velocity, characterized by only four dimensionless groups-i.e., two of them usually turn out to be unimportant. The important groups include a Biot number for the char, Bi{sub char}, and {omega}=1+{eta}{delta}H{sub comb}/{delta}H-bar{sub v}. Given that {eta}=0 and {omega}=1 for pyrolysis, the kinetics in that case are characterized entirely by three dimensionless groups, including Bi{sub char}. The conditions for the shrinking core model to apply to devolatilization and pyrolysis are discussed and are found not to apply, e.g., toward the end of devolatilization and for coals with low volatile contents. The model was used to calculate when reaction (I) starts after an initial heating period for a coal particle. The results are compared with experimental measurements (using gas chromatography of the volatiles released) of when various species (e.g., CO, CO{sub 2,} NO{sub x}, C{sub 2}H{sub 4}, C{sub 2}H{sub 6}, HCN) first appear from a pyrolyzing coal particle. These measurements confirm that reaction (I) can be assumed to occur at a mean temperature of {approx}500 K. (author)

  11. 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.

  12. Momentum noise in vacuum tunneling transducers

    NASA Astrophysics Data System (ADS)

    Yurke, B.; Kochanski, G. P.

    1990-04-01

    The vacuum tunneling probe can serve as a sensitive transducer of position into current. The performance of such a transducer is characterized by both the uncertainty in the inferred position ?x and the uncertainty in the momentum transfer ?p during the measurement. For realistic barrier parameters we find that the uncertainty product ?x ?p differs by less than 1% from ?/2. We also calculate the expectation values of the force associated with tunneling electrons. If sufficiently sensitive force measurements can be made, this force can provide information about a surface or an absorbed atom, differing from that provided by the tunneling current.

  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. 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.

  15. The effects of inlet turbulence and rotor\\/stator interactions on the aerodynamics and heat transfer of a large-scale rotating turbine model. Part 4: Aerodynamic data tabulation

    Microsoft Academic Search

    R. P. Dring; H. D. Joslyn; M. F. Blair

    1987-01-01

    A combined experimental and analytical program was conducted to examine the effects of inlet turbulence and 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 thermocouples welded to a thin,

  16. 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

  17. Partonic Transverse Momentum Distributions

    SciTech Connect

    Rossi, Patrizia [Laboratori Nazionali di Frascati-INFN, Via E. Fermi 40, 00044 Frascati (Italy)

    2010-08-04

    In recent years parton distributions have been generalized to account also for transverse degrees of freedom and new sets of more general distributions, Transverse Momentum Dependent (TMD) parton distributions and fragmentation functions were introduced. Different experiments worldwide (HERMES, COMPASS, CLAS, JLab-Hall A) have measurements of TMDs in semi-inclusive DIS processes as one of their main focuses of research. TMD studies are also an important part of the present and future Drell-Yan experiments at RICH and JPARC and GSI, respectively, Studies of TMDs are also one of the main driving forces of the Jefferson Lab (JLab) 12 GeV upgrade project. Progress in phenomenology and theory is flourishing as well. In this talk an overview of the latest developments in studies of TMDs will be given and newly released results, ongoing activities, as well as planned near term and future measurements will be discussed.

  18. Angular Momentum Diagrams

    NASA Astrophysics Data System (ADS)

    Wormer, Paul E. S.; Paldus, Josef

    Starting from the simplest possible building blocks--a ket, a bra, a time-reversed ket, and a time-reversed bra--a diagrammatic formalism is developed for angular momentum coupling problems. The formalism comprises Clebsch-Gordan coefficients as well as 3jm-symbols. The idea of constructing invariants (internal lines) by contracting contragredient pairs of quantities is emphasized throughout. The Clebsch-Gordan series, and its extension to the coupling of more than two angular momenta, is introduced algebraically and diagrammatically. Recoupling between bases obtained in different coupling schemes is introduced and the connection between recoupling coefficients and irreducible 3nj-symbols is derived diagrammatically. The well-known diagrammatic rules due to Jucys and co-workers are derived by group theoretical means and simple rules for their practical exploitation are presented.

  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. 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.

  1. 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.

  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

    Microsoft Academic Search

    R. P. Dring; M. F. Blair; H. D. Joslyn; G. D. Power; J. M. Verdon

    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,

  3. Reversal of wave momentum in isotropic left-handed media

    SciTech Connect

    Kemp, Brandon A.; Kong, Jin Au; Grzegorczyk, Tomasz M. [Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2007-05-15

    The electromagnetic wave momentum is derived for a Lorentz medium and applied to study the momentum transfer to stationary, isotropic left-handed materials. The model includes material dispersion and losses, which are necessary for a causal medium with negative index of refraction. The results provide a rigorous proof of the force on free currents in a lossy medium and a validation of the theoretical separation of force based on the real and imaginary parts of the permittivity and permeability. The resulting electromagnetic wave momentum conservation theorem proves that the momentum flux of a monochromatic wave in an isotropic left-handed material is opposite to the power flow direction. However, the momentum density in a lossy medium with a negative index of refraction may be parallel or antiparallel to the power flow. The results are applied to predict the reversal of radiation pressure on free currents in a material with a negative index of refraction. Furthermore, conservation of momentum at a material boundary states that the tangential component of the wave momentum is conserved. Thus there is no electromagnetic shear force at the boundary between isotropic media, regardless of the sign of the refractive index.

  4. Momentum potential theory of energy flux carried by momentum fluctuations

    Microsoft Academic Search

    P. E. Doak

    1989-01-01

    The momentum potential theory of time-stationary fluctuating flows is briefly reviewed and then extended to include energy flux carried by momentum fluctuations. It is shown that the mean (time-averaged) energy flux can be expressed as a linear superposition of mean, turbulent, acoustic and thermal components. A mean energy flux balance relating turbulent, acoustic and thermal energy fluxes only is obtained.

  5. Bias Momentum Attitude Control System Using Energy\\/Momentum Wheels

    Microsoft Academic Search

    Ying-hong JIA; Shi-jie XU; Liang TANG

    2004-01-01

    The integrated power and attitude control for a bias momentum attitude control system is investigated. A pair of counter spinning wheels is used to provide the bias angular momentum and store\\/discharge energy for power requirement of the devices on the spacecraft. The roll\\/yaw motion is controlled by pitch magnetic dipole moment. The torque based control law of the wheels is

  6. Angular momentum of walking at different speeds.

    PubMed

    Bennett, Bradford C; Russell, Shawn D; Sheth, Pradip; Abel, Mark F

    2010-02-01

    Recently, researchers in robotics have used regulation of the angular momentum of body segments about the total body center of mass (CoM) to develop control strategies for bipedal gait. This work was spurred by reports finding that for a "large class" of human movement tasks, including standing, walking, and running the angular momentum is conserved about the CoM. However, there is little data presented to justify this position. This paper describes an analysis of 11 male adults walking overground at 0.7, 1.0, and 1.3 times their comfortable walking speed (CWS). The normalized angular momenta about the body CoM of 12 body segments were computed about all three coordinate axes. The normalized angular momenta were both small (<0.03) and highly regulated for all subjects and walking speed with extrema that negatively correlated with walking speeds. It was found that the angular momentum of the body about its CoM during walking could be described by a small number of principal components. For the adult walkers the first three principal components accounted for more than 97% of the variability of the angular momentum about each of the three principal axes at all walking speeds. In addition, it was found that the orthogonal principal components at each speed and for each subject were similar, i.e., the vectors of the principal components at each speed and for each subject were co-linear. PMID:19889468

  7. ANGULAR MOMENTUM ACQUISITION IN GALAXY HALOS

    SciTech Connect

    Stewart, Kyle R. [Department of Natural and Mathematical Sciences, California Baptist University, 8432 Magnolia Ave., Riverside, CA 92504 (United States); Brooks, Alyson M. [Department of Astronomy, University of Wisconsin-Madison, 475 N. Charter St., Madison, WI 53706 (United States); Bullock, James S. [Center for Cosmology, Department of Physics and Astronomy, University of California at Irvine, Irvine, CA 92697 (United States); Maller, Ariyeh H. [Department of Physics, New York City College of Technology, 300 Jay St., Brooklyn, NY 11201 (United States); Diemand, Juerg [Institute for Theoretical Physics, University of Zurich, 8057, Zurich (Switzerland); Wadsley, James [Department of Physics and Astronomy, McMaster University, Main Street West, Hamilton L85 4M1 (Canada); Moustakas, Leonidas A. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2013-05-20

    We use high-resolution cosmological hydrodynamic simulations to study the angular momentum acquisition of gaseous halos around Milky-Way-sized galaxies. We find that cold mode accreted gas enters a galaxy halo with {approx}70% more specific angular momentum than dark matter averaged over cosmic time (though with a very large dispersion). In fact, we find that all matter has a higher spin parameter when measured at accretion than when averaged over the entire halo lifetime, and is well characterized by {lambda} {approx} 0.1, at accretion. Combined with the fact that cold flow gas spends a relatively short time (1-2 dynamical times) in the halo before sinking to the center, this naturally explains why cold flow halo gas has a specific angular momentum much higher than that of the halo and often forms ''cold flow disks.'' We demonstrate that the higher angular momentum of cold flow gas is related to the fact that it tends to be accreted along filaments.

  8. The regional climate effects of large-scale agricultural irrigation related to south-to-north water transfer engineering in China

    NASA Astrophysics Data System (ADS)

    Wang, Hanjie; Li, Jianyun; Ju, Yongmao; Yang, Chengyin

    2007-09-01

    Based on the agricultural geophysical classification and the land use and land cover (LULC) type map, the satellite data of multi-time, multi-spatial and multi-spectrum was used to identify the irrigation areas and their geographical locations of crops, plantations and pasture when the up-coming South-to North Water Transfer Engineering (SNWTE) is completed by 2030. The thermal-dynamics of the soil in the irrigated area was figured out depending on not only the satellite data deduction, but also on the on-site field measurements, the data of the nearby agro-meteorological and/or hydrological stations, which was used to calculate the variation regularity of soil moisture, soil temperature, albedo etc during each irrigation procedure. With reference of the methodology of pseudo-hydrodynamics in agro-hydrology, a new model module was designed to calculate the exchange and transfer process of water and heat energy in the soil-plant-atmosphere continuum (SPAC) under the condition of irrigation, which was coupled with the regional climate model RegCM3 and make it to include the irrigation effect. The new climate model was then used to simulate the regional climate change in north China as if SNWTE is completed. The preliminary simulation results show that: The large-scale agriculture irrigation might cause significant regional climate change not only in Northern China where the irrigation is implemented, but in the whole numerical domain as well. During the most possible irrigation time of summer months from June to August, the ground temperature, sensible heat flux in the boundary layer decreased within irrigated region and the adjacent areas; while the low-level air humidity, latent heat flux, and precipitation are all increased. Large-scale agricultural irrigation not only changes the water vapor factors such as soil moisture and air humidity, but also the thermal factors such as temperature and sensible heat flux and the dynamic factors of potential height and wind field in the atmosphere, which cause regional climate change in the whole numerical domain.

  9. Large-area fabrication of highly reproducible surface enhanced Raman substrate via a facile double sided tape-assisted transfer approach using hollow Au-Ag alloy nanourchins

    NASA Astrophysics Data System (ADS)

    Liu, Zhen; Cheng, Lin; Zhang, Lei; Jing, Chao; Shi, Xin; Yang, Zhongbo; Long, Yitao; Fang, Jixiang

    2014-02-01

    Ideally, a SERS substrate should possess super signal amplification, high uniformity and reproducibility. Up to now, an emphasis on reproducibility and uniformity has been crucial to ensure consistent chemical detection sensitivity across the surface of a SERS substrate. Here we demonstrate a simple and facile double sided tape-assisted transfer method to fabricate surface enhanced Raman scattering (SERS) substrates with prominent performance using hollow Au-Ag alloy nanourchins (HAAA-NUs). Such a large area, closely-packed flat film of the HAAA-NUs with a high density of ``hot spots'' exhibits a high SERS activity and reproducibility, simultaneously. The AFM-correlated nano-Raman and the point by point scanning of SERS signals verify the excellent spatial uniformity and reproducibility with a low relative standard deviation (RSD) less than 15% using crystal violet as probe molecule at the concentrations of 1 × 10-8 M and 1 × 10-10 M. The SERS signals of Sudan dye at a 1 × 10-8 M concentration also show high reproducibility with a low RSD of 13.8%. This facile protocol presented here could lead to a high quality SERS substrate and open tremendous potential for various applications.Ideally, a SERS substrate should possess super signal amplification, high uniformity and reproducibility. Up to now, an emphasis on reproducibility and uniformity has been crucial to ensure consistent chemical detection sensitivity across the surface of a SERS substrate. Here we demonstrate a simple and facile double sided tape-assisted transfer method to fabricate surface enhanced Raman scattering (SERS) substrates with prominent performance using hollow Au-Ag alloy nanourchins (HAAA-NUs). Such a large area, closely-packed flat film of the HAAA-NUs with a high density of ``hot spots'' exhibits a high SERS activity and reproducibility, simultaneously. The AFM-correlated nano-Raman and the point by point scanning of SERS signals verify the excellent spatial uniformity and reproducibility with a low relative standard deviation (RSD) less than 15% using crystal violet as probe molecule at the concentrations of 1 × 10-8 M and 1 × 10-10 M. The SERS signals of Sudan dye at a 1 × 10-8 M concentration also show high reproducibility with a low RSD of 13.8%. This facile protocol presented here could lead to a high quality SERS substrate and open tremendous potential for various applications. Electronic supplementary information (ESI) available: Fig. S1-S6. See DOI: 10.1039/c3nr05840a

  10. Generation of light with orbital angular momentum in optical fiber via acousto-optic interaction

    Microsoft Academic Search

    Henry P. Lee

    2006-01-01

    We examine acousto-optic interaction in optical Fiber from the perspective of co-propagating optical and acoustic vortex modes. Calculation of the coupling coefficient between different optical modes shows independent conservation of spin and orbital angular momentum of the interacting photons and phonons. We show that orbital angular momentum of the acoustic vortex can be transferred to a circularly polarized fundamental optical

  11. Momentum distributions of isotopes produced by fragmentation of relativistic C-12 and O-16 projectiles

    NASA Technical Reports Server (NTRS)

    Greiner, D. E.; Lindstrom, P. J.; Heckman, H. H.; Cork, B.; Bieser, F. S.

    1975-01-01

    The fragment momentum distributions in the projectile rest frame are, typically, Gaussian shaped, narrow, consistent with isotropy, depend on fragment and projectile, and have no significant correlation with target mass or beam energy. The nuclear temperature is inferred from the momentum distributions of the fragments and is approximately equal to the projectile nuclear binding energy, indicative of small energy transfer between target and fragment.

  12. Extreme nonlinear optical processes with beams carrying orbital angular momentum

    NASA Astrophysics Data System (ADS)

    Kern, C.; Zürch, M.; Hansinger, P.; Dreischuh, A.; Spielmann, Ch.

    2014-03-01

    Light beams carrying an isolated point singularity with a screw-type phase distribution are called an optical vortex (OV). The fact that in free space the Poynting vector of the beam gives the momentum flow leads to an orbital angular momentum (OAM) of the photons in such a singular beam, independent on the spin angular momentun1. There are many applications of optical OAM shown in literature that would benefit from the availability of optical vortex beams in all spectral regions. For example it was shown that transitions forbidden by selection rules in dipole approximation appear allowed when using photons with the additional degree of freedom of optical OAM2. However, the common techniques of producing new light frequencies by nonlinear optical processes seem problematic in conserving the optical vortex when the nonlinearity becomes large. We show that with the extremely nonlinear process of High Harmonic Generation (HHG) it is possible to transfer OVs from the near-infrared to the extreme ultraviolet (XUV)3 at wavelengths down to ~30 nm. The observed XUV light was examined spatially and spectrally. The spatial profile showed the expected singular behavior, a dark region in the center. A comparison of the far-field fringe pattern caused by a thin wire with corresponding simulations suggests that the XUV vortex beam carries a unit topological charge. A screw-like phase evolution around the profile was also verified by employing a Hartmann type measurement. The generated spectrum revealed that in all Harmonic orders an OV was present. The profile, however, looked the same in all orders, indicating identical topological charge, which runs counterintuitive to the assumption that the phase of exp(-il?) is multiplied by the harmonic order in a frequency up-conversion experiment.

  13. 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.

  14. Transverse angular momentum of photons

    E-print Network

    Andrea Aiello; Christoph Marquardt; Gerd Leuchs

    2010-03-04

    We develop the quantum theory of transverse angular momentum of light beams. The theory applies to paraxial and quasi-paraxial 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.

  15. 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.

  16. Transverse momentum distributions of hadrons

    SciTech Connect

    Jacak, B.

    1990-01-01

    The study of hadron production in heavy ion collisions is essential to the search for effects beyond independent nucleon-nucleon collisions, for example the predicted phase transition to quark matter. Hadron distributions are known over a large range of transverse momenta for p-p collisions, so a careful study of the differences can be made. The transverse momentum distributions of hadrons may provide global information about p-nucleus and nucleus-nucleus collisions, such as the degree of thermalization achieved, and perhaps provide evidence for collective expansion of the highly excited central region. Comparison of the p{sub t} and transverse mass, m{sub t}, distributions of different hadronic species are crucial to extract this kind of information. Hadronic p{sub t} spectra show effects of the collision dynamics, such as hard scattering processes, and possibly rescattering of partons as well as of the formed hadrons. Such modifications have been observed in p-nucleus collisions, and can be expected to be important in nucleus-nucleus reactions. The spectral shape changes arising in this manner cause a background in efforts to extract global information from hadronic p{sub t} spectra. Lastly, there is an excess of pions observed at low p{sub t} in p-A and A-A collisions. the origin of these soft pions is not yet well understood. The phenomenon represents a major difference between p-p and nuclear collisions. 31 refs., 8 figs.

  17. On the physics of momentum in ballistics: can the human body be displaced or knocked down by a small arms projectile?

    PubMed

    Karger, B; Kneubuehl, B P

    1996-01-01

    Shooting incidents are often portrayed as resulting in a sometimes violent backwards displacement of the victim. This opinion is also not infrequently held by expert witnesses. The physical force responsible for this would be momentum (mass x velocity). The physics of momentum in ballistic injury is explained in detail. The maximum momentum transferred from different small arms projectiles including large calibre rifles and a 12-gauge shotgun only results in a backwards motion of a 80 kg target body of 0.01-0.18 m/s, which is negligible compared to the velocity of a pedestrian (1-2 m/s). Furthermore, counterbalance is constantly maintained by neurophysiological reflexes. So the effect of the momentum transferred from the missile is virtually zero and there is no backwards motion of the person shot. Empirical evidence verifying these calculations can be obtained from hunting big game, from human gunshot victims and from a video documentary demonstrating the lack of any backwards motion of a person wearing body armour after hits from a centre fire rifle. So the alleged backwards hurling of a person shot is nothing but a myth which should be refuted not only because it is incorrect but also because it can result in miscarriages of justice. PMID:8956990

  18. Angular Momentum Form of Verlet Algorithm for Rigid Molecules

    NASA Astrophysics Data System (ADS)

    Hiyama, Miyabi; Kinjo, Tomoyuki; Hyodo, Shi-aki

    2008-06-01

    A new simple algorithm is presented for solving the equations of motion for rigid molecules. These equations are integrated using a Verlet framework in the angular momentum form. This simple algorithm is named “the angular momentum Verlet algorithm”. For obtaining a high accuracy in molecular dynamics (MD) simulations, we introduce the scaling method with the constraint by Lagrange’s method of undetermined multipliers. The results of MD simulations for carbon tetrachloride using the angular momentum Verlet algorithm are reported. The relative total energy fluctuations for carbon tetrachloride using the angular momentum Verlet algorithm are compared with those using the standard leap-frog and Gear predictor-corrector algorithms. The energy drift using the angular momentum Verlet algorithm is smaller than that using the leap-frog or Gear predictor-corrector algorithm, particularly for large time intervals. The MD simulations for AXnY4-n-type models having different moments of inertia are also carried out to investigate the effects of the angular momentum Verlet algorithm for molecules with different symmetries. We found that the time integrations for the model with the largest moment of inertia are stable. The scaling method with the constraint by Lagrange’s method of undetermined multipliers in the angular momentum Verlet algorithm is effective in obtaining a smaller energy drift, particularly for large time intervals.

  19. Momentum-Dependent Charge Transfer Excitations in Sr{sub {bold 2}}CuO {sub {bold 2}}Cl{sub {bold 2}} Angle-Resolved Electron Energy Loss Spectroscopy

    SciTech Connect

    Wang, Y.Y.; Zhang, F.C.; Dravid, V.P.; Ng, K.K.; Klein, M.V.; Schnatterly, S.E.; Miller, L.L. [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States)] [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); [Science and Technology Center for Superconductivity, Northwestern University, Evanston, Illinois 60208 (United States); [Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221 (United States); [Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); [Department of Physics, Science and Technology Center for Superconductivity, University of Illinois, Urbana, Illinois 61801 (United States); [Department of Physics, University of Virginia, Charlottesville, Virginia 22901 (United States); [Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States)

    1996-08-01

    Electron-hole pair excitations in the insulating cuprates Sr{sub 2}CuO{sub 2}Cl{sub 2} were investigated by angle-resolved electron energy loss spectroscopy. The optically allowed and optically forbidden transitions were observed to be strongly anisotropic in Cu-O{sub 2} plane. The former show a large energy dispersion {approximately}1.5 eV along [110], and the latter appear at a higher energy position ({approximately}4.5 eV) only along [100], but not along [110]. We interpret these results as transitions involving excitons. A small exciton model is examined to explain both the observed features. {copyright} {ital 1996 The American Physical Society.}

  20. Average transverse momentum quantities approaching the lightfront

    E-print Network

    Daniel Boer

    2014-09-29

    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.

  1. 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.

  2. Angular momentum & spin January 8, 2002

    E-print Network

    Landstreet, John D.

    Angular momentum & spin January 8, 2002 1 Angular momentum Angular momentum appears as a very properties of this quantity. 1.1 Definitions The classical definition of the angular momentum of a particle¯h, the quantum mechanical operator for angular momentum becomes L = -i¯h(r × ), for example Lz = -i¯h(x y - y x

  3. 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.

  4. 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.

  5. A January angular momentum balance in the OSU two-level atmospheric general circulation model

    NASA Technical Reports Server (NTRS)

    Kim, J.-W.; Grady, W.

    1982-01-01

    The present investigation is concerned with an analysis of the atmospheric angular momentum balance, based on the simulation data of the Oregon State University two-level atmospheric general circulation model (AGCM). An attempt is also made to gain an understanding of the involved processes. Preliminary results on the angular momentum and mass balance in the AGCM are shown. The basic equations are examined, and questions of turbulent momentum transfer are investigated. The methods of analysis are discussed, taking into account time-averaged balance equations, time and longitude-averaged balance equations, mean meridional circulation, the mean meridional balance of relative angular momentum, and standing and transient components of motion.

  6. 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

  7. Angular Momentum Balance Tuesday, January 7, 2014

    E-print Network

    Bordoni, Simona

    Angular Momentum Balance and Winds Tuesday, January 7, 2014 #12;(Source: CLAUS, http Extratropical macroturbulence transports angular momentum into regions of wave generation !"#$%&'( )*+,( )*+-( Tuesday, January 7, 2014 #12;Eddy angular momentum transport (ERA-40 Atlas, http

  8. 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.

  9. Angular momentum and Killing potentials

    NASA Astrophysics Data System (ADS)

    Glass, E. N.

    1996-01-01

    When the Penrose-Goldberg (PG) superpotential is used to compute the angular momentum of an axial symmetry, the Killing potential Q??(?) for that symmetry is needed. Killing potentials used in the PG superpotential must satisfy Penrose's equation. It is proved for the Schwarzschild and Kerr solutions that the Penrose equation does not admit a Q??(?) at finite r and therefore the PG superpotential can only be used to compute angular momentum asymptotically.

  10. 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

    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. 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,10 D. Day,10 J. A. Dunne,9,§ D. Dutta,7 R. Ent,9 B. W. Filippone,2 A. Honegger,1 E. W. Hughes,2 J

  11. 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.

  12. The role of angular momentum in collision-induced vibration-rotation relaxation in polyatomics.

    PubMed

    McCaffery, Anthony J; Osborne, Mark A; Marsh, Richard J; Lawrance, Warren D; Waclawik, Eric R

    2004-07-01

    Vibrational relaxation of the 6(1) level of S(1)((1)B(2u)) benzene is analyzed using the angular momentum model of inelastic processes. Momentum-(rotational) angular momentum diagrams illustrate energetic and angular momentum constraints on the disposal of released energy and the effect of collision partner on resultant benzene rotational excitation. A kinematic "equivalent rotor" model is introduced that allows quantitative prediction of rotational distributions from inelastic collisions in polyatomic molecules. The method was tested by predicting K-state distributions in glyoxal-Ne as well as J-state distributions in rotationally inelastic acetylene-He collisions before being used to predict J and K distributions from vibrational relaxation of 6(1) benzene by H(2), D(2), and CH(4). Diagrammatic methods and calculations illustrate changes resulting from simultaneous collision partner excitation, a particularly effective mechanism in p-H(2) where some 70% of the available 6(1)-->0(0) energy may be disposed into 0-->2 rotation. These results support the explanation for branching ratios in 6(1)-->0(0) relaxation given by Waclawik and Lawrance and the absence of this pathway for monatomic partners. Collision-induced vibrational relaxation in molecules represents competition between the magnitude of the energy gap of a potential transition and the ability of the colliding species to generate the angular momentum (rotational and orbital) needed for the transition to proceed. Transition probability falls rapidly as DeltaJ increases and for a given molecule-collision partner pair will provide a limit to the gap that may be bridged. Energy constraints increase as collision partner mass increases, an effect that is amplified when J(i)>0. Large energy gaps are most effectively bridged using light collision partners. For efficient vibrational relaxation in polyatomics an additional requirement is that the molecular motion of the mode must be capable of generating molecular rotation on contact with the collision partner in order to meet the angular momentum requirements. We postulate that this may account for some of the striking propensities that characterize polyatomic energy transfer. PMID:15260535

  13. Resistance to extinction and behavioral momentum

    PubMed Central

    Nevin, John A.

    2012-01-01

    In the metaphor of behavioral momentum, reinforcement is assumed to strengthen discriminated operant behavior in the sense of increasing its resistance to disruption, and extinction is viewed as disruption by contingency termination and reinforcer omission. In multiple schedules of intermittent reinforcement, resistance to extinction is an increasing function of reinforcer rate, consistent with a model based on the momentum metaphor. The partial-reinforcement extinction effect, which opposes the effects of reinforcer rate, can be explained by the large disruptive effect of terminating continuous reinforcement despite its strengthening effect during training. Inclusion of a term for the context of reinforcement during training allows the model to account for a wide range of multiple-schedule extinction data and makes contact with other formulations. The relation between resistance to extinction and reinforcer rate on single schedules of intermittent reinforcement is exactly opposite to that for multiple schedules over the same range of reinforcer rates; however, the momentum model can give an account of resistance to extinction in single as well as multiple schedules. An alternative analysis based on the number of reinforcers omitted to an extinction criterion supports the conclusion that response strength is an increasing function of reinforcer rate during training. PMID:22425781

  14. 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.

  15. Angular momentum transport in stellar interiors

    NASA Astrophysics Data System (ADS)

    Mathis, S.

    2011-12-01

    In this short article we review the advances that have been obtained in the global modelling of angular momentum transport in stellar interiors during the last years. First, we consider the couplings between differential rotation and the large-scale meridional circulation and shear-induced turbulence this induces. Then, we describe the state of the art of our understanding of transport mechanisms in presence of a fossil magnetic field. Next, we show how rotation and magnetic fields are now taken into account in the study of internal waves. Finally, we emphasize that it becomes necessary to get a complete picture of the interaction of stars with their environment.

  16. Accelerated rotation with orbital angular momentum modes

    NASA Astrophysics Data System (ADS)

    Schulze, Christian; Roux, Filippus S.; Dudley, Angela; Rop, Ronald; Duparré, Michael; Forbes, Andrew

    2015-04-01

    We introduce a class of light field that angularly accelerates during propagation. We show that the acceleration (deceleration) may be controlled by adjustment of a single parameter, and tuned continuously, down to no acceleration at all. As the angular acceleration takes place in a bounded space, the azimuthal degree of freedom, such fields accelerate periodically as they propagate. Notably, the amount of angular acceleration is not limited by paraxial considerations, may be tailored for large accelerations over arbitrarily long distances, and can be engineered independently of the beam's spatial extent. We discuss how such angularly accelerating light fields can maintain the conservation of angular momentum through an energy exchange mechanism across the field.

  17. 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 STANS boundary layer code. Also, a leading edge separation bubble was revealed by thermal and flow visualization.

  18. Electron momentum distribution function in the t- t?- J model

    NASA Astrophysics Data System (ADS)

    Ramšak, Anton; Sega, Igor; Prelovšek, Peter

    2000-07-01

    We study the electron momentum distribution function (EMDF) for the two-dimensional t- t?- J model doped with one hole on finite clusters by the method of twisted boundary conditions. The results quantitatively agree with our analytical results for a single hole in the antiferromagnetic background, based on the self-consistent Born approximation (SCBA). Moreover, within the SCBA an anomalous momentum dependence of EMDF is found, pointing to an emerging large Fermi surface. The analysis shows that the presence of next-nearest-neighbor (NNN) hopping terms changes EMDF only quantitatively if the ground state (GS) momentum is at (?/2,?2) and qualitatively if the GS momentum is shifted to (?,0).

  19. 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.

  20. 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.

  1. 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 cm-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 2.8×105 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 rinit must satisfy ?, rinit < rsf/3, where the shell formation radius is given by rsf=30 pc n0-0.46 for two-phase models (or 30% smaller for a homogeneous medium).

  2. 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

  3. 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

  4. Dogs Leaving the ICU Carry a Very Large Multi-Drug Resistant Enterococcal Population with Capacity for Biofilm Formation and Horizontal Gene Transfer

    PubMed Central

    Ghosh, Anuradha; Dowd, Scot E.; Zurek, Ludek

    2011-01-01

    The enterococcal community from feces of seven dogs treated with antibiotics for 2–9 days in the veterinary intensive care unit (ICU) was characterized. Both, culture-based approach and culture-independent 16S rDNA amplicon 454 pyrosequencing, revealed an abnormally large enterococcal community: 1.4±0.8×108 CFU gram?1 of feces and 48.9±11.5% of the total 16,228 sequences, respectively. The diversity of the overall microbial community was very low which likely reflects a high selective antibiotic pressure. The enterococcal diversity based on 210 isolates was also low as represented by Enterococcus faecium (54.6%) and Enterococcus faecalis (45.4%). E. faecium was frequently resistant to enrofloxacin (97.3%), ampicillin (96.5%), tetracycline (84.1%), doxycycline (60.2%), erythromycin (53.1%), gentamicin (48.7%), streptomycin (42.5%), and nitrofurantoin (26.5%). In E. faecalis, resistance was common to tetracycline (59.6%), erythromycin (56.4%), doxycycline (53.2%), and enrofloxacin (31.9%). No resistance was detected to vancomycin, tigecycline, linezolid, and quinupristin/dalfopristin in either species. Many isolates carried virulence traits including gelatinase, aggregation substance, cytolysin, and enterococcal surface protein. All E. faecalis strains were biofilm formers in vitro and this phenotype correlated with the presence of gelE and/or esp. In vitro intra-species conjugation assays demonstrated that E. faecium were capable of transferring tetracycline, doxycycline, streptomycin, gentamicin, and erythromycin resistance traits to human clinical strains. Multi-locus variable number tandem repeat analysis (MLVA) and pulsed-field gel electrophoresis (PFGE) of E. faecium strains showed very low genotypic diversity. Interestingly, three E. faecium clones were shared among four dogs suggesting their nosocomial origin. Furthermore, multi-locus sequence typing (MLST) of nine representative MLVA types revealed that six sequence types (STs) originating from five dogs were identical or closely related to STs of human clinical isolates and isolates from hospital outbreaks. It is recommended to restrict close physical contact between pets released from the ICU and their owners to avoid potential health risks. PMID:21811613

  5. 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

    laboratory. ' It is worth emphasizing that the TEC is segmented and is not run as a simple sum spectrometer. During the off line analysis, the total gamma energy in each event was determined by summing the energy deposited in each of the segments... t i h TEC sing gamma ra assembl energy up to 1.9 MeV II. EXPERIMENTALL DETAILS The expenments w the Variiable Ener C were perform gy med using ' 0 The experim yclotron at T m ' bearns from 2 rimental arran exas A&M U ' he s own in F...

  6. 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...

  7. Single beam optical vortex tweezers with tunable orbital angular momentum

    NASA Astrophysics Data System (ADS)

    Gecevi?ius, Mindaugas; Drevinskas, Rokas; Beresna, Martynas; Kazansky, Peter G.

    2014-06-01

    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. 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.

  9. Intercomponent momentum transport and electrical conductivity of collisionless plasma

    NASA Technical Reports Server (NTRS)

    Wilhelm, H. E.

    1973-01-01

    Based on the Lenard-Balescu equation, the interaction integral for the intercomponent momentum transfer in a two-component, collisionless plasma is evaluated in closed form. The distribution functions of the electrons and ions are represented in the form of nonisothermal, displaced Maxwellians corresponding to the 5-moment approximation. As an application, the transport of electrical current in an electric field is discussed for infrasonic up to sonic electron-ion drift velocities.

  10. Momentum transfer of a Boltzmann-lattice fluid with boundaries

    Microsoft Academic Search

    M'hamed Bouzidi; Mouaouia Firdaouss; Pierre Lallemand

    2001-01-01

    We study the velocity boundary condition for curved boundaries in the lattice Boltzmann equation (LBE). We propose a LBE boundary condition for moving boundaries by combination of the ``bounce-back'' scheme and spatial interpolations of first or second order. The proposed boundary condition is a simple, robust, efficient, and accurate scheme. Second-order accuracy of the boundary condition is demonstrated for two

  11. Plasma detachment and momentum transfer in magnetic nozzles

    E-print Network

    Choueiri, Edgar

    questioned, however, due to the tendency of the highly conductive plasma to remain tied to necessarily closed magnetic field lines. Efficient detachment of the plasma from the magnetic nozzle thus becomes paramount resistive diffusion of the plasma across the applied magnetic field lines.2 Many plasmas of interest

  12. Heat transfer in pipes

    NASA Astrophysics Data System (ADS)

    Burbach, T.

    1985-04-01

    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.

  13. 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.

  14. 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.

  15. 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.

  16. Relaxation of rotational angular momentum of polar diatomic molecules in simple liquids

    SciTech Connect

    Padilla, A.; Perez, J. [Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, 38204 Tenerife (Spain)

    2007-03-15

    The relaxation processes of rotational angular momentum of polar diatomic molecules diluted in simple liquids are analyzed by applying a non-Markovian relaxation theory to the study of the binary time autocorrelation function of the angular momentum. This non-Markovian theory was previously applied to the study of the infrared and Raman spectroscopy, and also to the analysis of the rotational energy relaxation processes. We have obtained non-Markovian evolution equations for the two-time j-level angular momentum correlation components involved in the angular momentum correlation function. In these equations, the time-dependent angular momentum transfer rates and the pure orientational angular transfer rates are given in terms of the binary time autocorrelation function of the diatomic-solvent anisotropic interaction. The non-Markovian evolution equations converge to Markovian ones in the long time limit, reaching the angular momentum transfer rates in the usual time-independent form. Alternative time scales for the angular relaxation processes, relative to the individual rotational processes as well as to the global decay correlations, are introduced and analyzed. The theory is applied to the study of the angular momentum relaxation processes of HCl diluted in liquid SF{sub 6}, a system for which rotational energy relaxation and infrared and Raman spectroscopy was previously analyzed in the scope of the same theory.

  17. Automated Angular Momentum Recoupling Algebra

    NASA Astrophysics Data System (ADS)

    Williams, H. T.; Silbar, Richard R.

    1992-04-01

    We present a set of heuristic rules for algebraic solution of angular momentum recoupling problems. The general problem reduces to that of finding an optimal path from one binary tree (representing the angular momentum coupling scheme for the reduced matrix element) to another (representing the sub-integrals and spin sums to be done). The method lends itself to implementation on a microcomputer, and we have developed such an implementation using a dialect of LISP. We describe both how our code, called RACAH, works and how it appears to the user. We illustrate the use of RACAH for several transition and scattering amplitude matrix elements occurring in atomic, nuclear, and particle physics.

  18. 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.

  19. Measuring and optimizing the momentum aperture in a particle accelerator.

    PubMed

    Steier, C; Robin, D; Nadolski, L; Decking, W; Wu, Y; Laskar, J

    2002-05-01

    Particle motion in storage rings is confined by various aperture limits, the size of which restricts the performance of the ring in terms of injection efficiency, lifetime, etc. Intrabeam scattering makes particles sweep a large portion of the phase space, where their motion may eventually be resonantly or chaotically excited to large amplitudes leading to collision with the vacuum chamber. We report here the studies performed at the Advanced Light Source (ALS) on the on- and off-momentum particle motion that provides a good understanding of these limitations. Using off-momentum simulations and experiments together with frequency map analysis, we could precisely correlate beam loss areas with resonance locations. The very good agreement between simulations and experiments allowed us to provide guidance for avoiding these dangerous areas. This analysis results in predictive improvements of the momentum aperture, which actually led to a lifetime increase of 25% at the ALS for very high bunch charge. PMID:12059724

  20. 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.

  1. Angular Momentum Accretion onto a Gas Giant Planet

    E-print Network

    Masahiro N. Machida; Eiichiro Kokubo; Shu-ichiro Inutsuka; Tomoaki Matsumoto

    2008-01-22

    We investigate the accretion of angular momentum onto a protoplanet system using three-dimensional hydrodynamical simulations. We consider a local region around a protoplanet in a protoplanetary disk with sufficient spatial resolution. We describe the structure of the gas flow onto and around the protoplanet in detail. We find that the gas flows onto the protoplanet system in the vertical direction crossing the shock front near the Hill radius of the protoplanet, which is qualitatively different from the picture established by two-dimensional simulations. The specific angular momentum of the gas accreted by the protoplanet system increases with the protoplanet mass. At Jovian orbit, when the protoplanet mass M_p is M_p angular momentum increases as j \\propto M_p. On the other hand, it increases as j \\propto M_p^2/3 when the protoplanet mass is M_p > 1 M_J. The stronger dependence of the specific angular momentum on the protoplanet mass for M_p angular momentum of a system of a gas giant planet and a circumplanetary disk is two-orders of magnitude larger than those of the present gas giant planets in the solar system. A large fraction of the total angular momentum contributes to the formation of the circumplanetary disk. We also discuss the satellite formation from the circumplanetary disk.

  2. Angular momentum of isolated systems

    NASA Astrophysics Data System (ADS)

    Helfer, Adam D.

    2007-12-01

    Penrose’s twistorial approach to the definition of angular momentum at null infinity is developed so that angular momenta at different cuts can be meaningfully compared. This is done by showing that the twistor spaces associated with different cuts of mathcal{J}^+ can be identified as manifolds (but not as vector spaces). The result is a well-defined, Bondi-Metzner-Sachs-invariant notion of angular momentum in a radiating space-time; the difficulties and ambiguities previously encountered are attached to attempts to express this in special-relativistic terms, and in particular to attempts to identify a single Minkowski space of origins. Unlike the special-relativistic case, the angular momentum cannot be represented by a purely j = 1 quantity M ab , but has higher- j contributions as well. Applying standard kinematic prescriptions, these higher- j contributions are shown to correspond precisely to the shear. Thus it appears that shear and angular momentum should be regarded as different aspects of a single unified concept.

  3. Representational Momentum in Older Adults

    ERIC Educational Resources Information Center

    Piotrowski, Andrea S.; Jakobson, Lorna S.

    2011-01-01

    Humans have a tendency to perceive motion even in static images that simply "imply" movement. This tendency is so strong that our memory for actions depicted in static images is distorted in the direction of implied motion--a phenomenon known as representational momentum (RM). In the present study, we created an RM display depicting a pattern of…

  4. Unified Angular Momentum of Dyons

    E-print Network

    Shalini Dangwal; P. S. Bisht; O. P. S. Negi

    2006-08-22

    Unified quaternionic angular momentum for the fields of dyons and gravito-dyons has been developed and the commutation relations for dynamical variables are obtained in compact and consistent manner. Demonstrating the quaternion forms of unified fields of dyons (electromagnetic fields) and gravito-dyons (gravito-Heavisidian fields of linear gravity), corresponding quantum equations are reformulated in compact, simpler and manifestly covariant way.

  5. Angular momentum of isolated systems

    E-print Network

    Adam D. Helfer

    2007-09-07

    Penrose's twistorial approach to the definition of angular momentum at null infinity is developed so that angular momenta at different cuts can be meaningfully compared. This is done by showing that the twistor spaces associated with different cuts of scri can be identified as manifolds (but not as vector spaces). The result is a well-defined, Bondi-Metzner-Sachs-invariant notion of angular momentum in a radiating space-time; the difficulties and ambiguities previously encountered are attached to attempts to express this in special-relativistic terms, and in particular to attempts to identify a single Minkowski space of origins. Unlike the special-relativistic case, the angular momentum cannot be represented by a purely j=1 quantity M_{ab}, but has higher-j contributions as well. Applying standard kinematic prescriptions, these higher-j contributions are shown to correspond precisely to the shear. Thus it appears that shear and angular momentum should be regarded as different aspects of a single unified concept.

  6. The lunar angular momentum problem

    NASA Technical Reports Server (NTRS)

    Weidenschilling, S. J.

    1984-01-01

    Formation of the Moon by classical Darwin-type fission of a rapidly spinning proto-Earth is discussed. The relationship of angular momentum to accretion disks is examined. The co-accretion scenario and Darwin-type fission are compared and evaluated.

  7. 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…

  8. 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

  9. 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.

  10. Transverse momentum distributions of jets and weak bosons

    SciTech Connect

    Ellis, R.K.

    1984-05-01

    The theoretical description of processes leading to events at large transverse momentum is reviewed. Numerical estimates are given for jet cross-sections and for W and Z production cross-sections. The influence which uncertainties in the input parameters have on the theoretical predictions is also discussed.

  11. The effects of inlet turbulence and rotor/stator interactions on the aerodynamics and heat transfer of a large-scale rotating turbine model. Part 4: Aerodynamic data tabulation

    NASA Technical Reports Server (NTRS)

    Dring, R. P.; Joslyn, H. D.; Blair, M. F.

    1987-01-01

    A combined experimental and analytical program was conducted to examine the effects of inlet turbulence and 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 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, first stator-rotor axial spacing, Reynolds number and relative circumferential position of the first and second stators. Aerodynamic measurements obtained 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. 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.

  12. Squids, supercurrents, and slope anomalies: Nuclear structure from heavy-ion transfer reactions

    SciTech Connect

    Guidry, M.W.

    1989-01-01

    Within the past five years we have developed experimental techniques to study heavy-ion transfer reactions to high spin states in deformed nuclei. These methods have been turned into a quantitative tool to assess the influence of collective excitation on single-particle and pairing structure. I discuss some of the nuclear structure questions which are being answered in these experiments: How strong is ground state pairing How does pairing change with angular momentum Why is two-neutron transfer much stronger than expected at large radial separation What is the evidence for a nuclear Josephson Effect What is the evidence for a nuclear Berry phase effect (nuclear SQUID) Why does one-neutron transfer populate much higher spins than would be naively expected Conversely, why does two-neutron transfer populate much lower spins than anyone expected The answer to each of these questions involves the influence of detailed nuclear structure on transfer reactions, and represents quantitative new information about the effect of angular momentum and excitation energy on many-body systems with a finite number of particles. 8 refs., 6 figs.

  13. Trajectory study of energy transfer and unimolecular dissociation of highly excited allyl with argon.

    PubMed

    Conte, Riccardo; Houston, Paul L; Bowman, Joel M

    2014-09-11

    The influence of rotational excitation on energy transfer in single collisions of allyl with argon and on allyl dissociation is investigated. About 90,000 classical scattering simulations are performed in order to determine collision-induced changes in internal energy and in allyl rotational angular momentum. Dissociation is studied by means of about 50,000 additional trajectories evolved for the isolated allyl under three different conditions: allyl with no angular momentum (J = 0); allyl with the same microcanonically sampled initial conditions used for the collisions (J*); allyl evolving from the corresponding exit conditions after the collision. The potential energy surface is the sum of an intramolecular potential and an interaction one, and it has already been used in a previous work on allyl-argon scattering (Conte, R.; Houston, P. L.; Bowman, J. M. J. Phys. Chem. A 2013, 117, 14028-14041). Energy transfer data show that increased initial rotation favors, on average, increased relaxation of the excited molecule. The availability of a high-level intramolecular potential energy surface permits us to study the dependence of energy transfer on the type of starting allyl isomer. A turning point analysis is presented, and highly efficient collisions are detected. Collision-induced variations in the allyl rotational angular momentum may be quite large and are found to be distributed according to three regimes. The roles of rotational angular momentum, collision, and type of isomer on allyl unimolecular dissociation are considered by looking at dissociations times, kinetic energies of the fragments, and branching ratios. Generally, rotational angular momentum has a strong influence on the dissociation dynamics, while the single collision and the type of starting isomer are less influential. PMID:25116695

  14. Moments of nuclear and nucleon structure functions at low Q2 and the momentum sum rule

    NASA Astrophysics Data System (ADS)

    Niculescu, I.; Arrington, J.; Ent, R.; Keppel, C. E.

    2006-04-01

    New nuclear structure function data from Jefferson Lab covering the higher-x and lower-Q2 regime make it possible to extract the higher-order F2 moments for iron and deuterium at low four-momentum transfer squared Q2. These moments allow for an experimental investigation of the nuclear momentum sum rule and a direct comparison of the nonsinglet nucleon moment with lattice QCD results.

  15. Spacetimes with Semisymmetric Energy-Momentum Tensor

    NASA Astrophysics Data System (ADS)

    De, U. C.; Velimirovi?, Ljubica

    2015-06-01

    The object of the present paper is to introduce spacetimes with semisymmetric energy-momentum tensor. At first we consider the relation R( X, Y)? T=0, that is, the energy-momentum tensor T of type (0,2) is semisymmetric. It is shown that in a general relativistic spacetime if the energy-momentum tensor is semisymmetric, then the spacetime is also Ricci semisymmetric and the converse is also true. Next we characterize the perfect fluid spacetime with semisymmetric energy-momentum tensor. Then, we consider conformally flat spacetime with semisymmetric energy-momentum tensor. Finally, we cited some examples of spacetimes admitting semisymmetric energy-momentum tensor.

  16. Causality and momentum conservation from relative locality

    NASA Astrophysics Data System (ADS)

    Amelino-Camelia, Giovanni; Bianco, Stefano; Brighenti, Francesco; Buonocore, Riccardo Junior

    2015-04-01

    Theories involving curved momentum space, which recently became a topic of interest in the quantum-gravity literature, can, in general, violate many apparently robust aspects of our current description of the laws of physics, including relativistic invariance, locality, causality, and global momentum conservation. Here, we explore some aspects of the pathologies arising in generic theories involving curved momentum space for what concerns causality and momentum conservation. However, we also report results suggesting that when momentum space is maximally symmetric, and the theory is formulated relativistically, most notably including translational invariance with the associated relativity of spacetime locality, momentum is globally conserved and there is no violation of causality.

  17. Calculations of population transfer during intense laser pulses

    SciTech Connect

    Schafer, K.J.; Kulander, K.C.

    1993-08-01

    Recent experiments by several groups have examined the question of population transfer to resonantly excited states during intense short laser pulses, in particular the amount of population that remains ``trapped`` in excited states at the end of a laser pulse. In this chapter we present calculations of population transfer and resonant ionization in xenon at both 660 and 620 nm. At the longer wavelength, the seven photon channel closes at 2.5{times}10{sup 13} W/cm{sup 2}. Pulses with peak intensities higher than this result in ``Rydberg trapping``, the resonant transfer of population to a broad range of high-lying states. The amount of population transferred depends on both the peak intensity and pulse duration. At 620 mm there are numerous possible six photon resonances to states with p or f angular momentum. We have done a large number of calculations for 40 fs pulses at different peak intensities and have examined the population transferred to these low-lying resonant states as a function of the peak laser intensity. We do not have room to comment upon the resonantly enhanced ionized electron energy spectra that we also determine in the same calculations. Our calculations involve the direct numerical integration of the time-dependent Schroedinger equation for an atom interacting with a strong laser field. The time-dependent wave function of a given valence electron is calculated on a spatial grid using a one-electron pseudo potential. This single active electron approximation (SAE) has been shown to be a good approximation for the rare gases at the intensities and wavelengths that we will consider. The SAE potential we use has an explicit angular momentum dependence which allows us to reproduce all of the excited state energies for xenon quite well.

  18. 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 $\\mu=0$.

  19. A simple holographic superconductor with momentum relaxation

    NASA Astrophysics Data System (ADS)

    Kim, Keun-Young; Kim, Kyung Kiu; Park, Miok

    2015-04-01

    We study a holographic superconductor model with momentum relaxation due to massless scalar fields linear to spatial coordinates( ? I = ?? Ii x i ), where ? is the strength of momentum relaxation. In addition to the original superconductor induced by the chemical potential( ?) at ? = 0, there exists a new type of superconductor induced by ? even at ? = 0. It may imply a new `pairing' mechanism of particles and antiparticles interacting with ?, which may be interpreted as `impurity'. Two parameters ? and ? compete in forming superconducting phase. As a result, the critical temperature behaves differently depending on ?/?. It decreases when ?/? is small and increases when ?/? is large, which is a novel feature compared to other models. After analysing ground states and phase diagrams for various ?/?, we study optical electric( ?), thermoelectric( ?), and thermal() conductivities. When the system undergoes a phase transition from normal to a superconducting phase, 1 /? pole appears in the imaginary part of the electric conductivity, implying infinite DC conductivity. If ?/? < 1, at small ?, a two-fluid model with an imaginary 1 /? pole and the Drude peak works for ?, ?, and , but If ?/? > 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 ? = 0.

  20. Electric Field in a Double Layer and the Imparted Momentum

    SciTech Connect

    Fruchtman, A. [Holon Academic Institute of Technology, 52 Golomb Street, Holon 58102 (Israel)

    2006-02-17

    It is shown that the net momentum delivered by the large electric field inside a one-dimensional double layer is zero. This is demonstrated through an analysis of the momentum balance in the double layer at the boundary between the ionosphere and the aurora cavity. For the recently observed double layer in a current-free plasma expanding along a divergent magnetic field, an analysis of the evolution of the radially averaged variables shows that the increase of plasma thrust results from the magnetic-field pressure balancing the plasma pressure in the direction of acceleration, rather than from electrostatic pressure.

  1. Electric field in a double layer and the imparted momentum.

    PubMed

    Fruchtman, A

    2006-02-17

    It is shown that the net momentum delivered by the large electric field inside a one-dimensional double layer is zero. This is demonstrated through an analysis of the momentum balance in the double layer at the boundary between the ionosphere and the aurora cavity. For the recently observed double layer in a current-free plasma expanding along a divergent magnetic field, an analysis of the evolution of the radially averaged variables shows that the increase of plasma thrust results from the magnetic-field pressure balancing the plasma pressure in the direction of acceleration, rather than from electrostatic pressure. PMID:16606002

  2. Rapid-cycling synchrotron with variable momentum compaction

    SciTech Connect

    Alexahin, Y.; /Fermilab; Summers, D.J.; /Mississippi U.

    2010-05-01

    There are conflicting requirements on the value of the momentum compaction factor during energy ramping in a synchrotron: at low energies it should be positive and sufficiently large to make the slippage factor small so that it is possible to work closer to the RF voltage crest and ensure sufficient RF bucket area, whereas at higher energies it should be small or negative to avoid transition crossing. In the present report we propose a lattice with a variable momentum compaction factor and consider the possibility of using it in a high repetition rate proton driver for a muon collider and neutrino factory.

  3. Impulsive formation control using orbital energy and angular momentum vector

    NASA Astrophysics Data System (ADS)

    Choi, Yoonhyuk; Mok, Sunghoon; Bang, Hyochoong

    2010-09-01

    This paper presents a multi-impulsive formation control strategy using orbit energy-matching and relative angular momentum vector between leader and follower satellites. These conservative parameters (energy and angular momentum) provide analytical and global solutions for orbital maneuver design without relying on Gauss variational equations. The relationship with orbit element differences is discussed in the simplifying assumptions. The proposed approach is free from small variation assumptions, so that it is suitable for handling even the case of large error corrections. General limitations of impulse control and associated compensation maneuvers are also addressed.

  4. Measurement of charged particle transverse momentum spectra in deep inelastic scattering

    Microsoft Academic Search

    C. Adloff; S. Aid; M. Anderson; V. Andreev; B. Andrieu; A. Babaev; J. Bähr; J. Bán; Y. Ban; P. Baranov; E. Barrelet; R. Barschke; W. Bartel; M. Barth; U. Bassler; H. P. Beck; M. Beck; H.-J. Behrend; A. Belousov; Ch. Berger; G. Bernardi; G. Bertrand-Coremans; M. Besançon; R. Beyer; P. Biddulph; P. Bispham; J. C. Bizot; V. Blobel; K. Borras; F. Botterweck; V. Boudry; A. Braemer; W. Braunschweig; V. Brisson; W. Brückner; P. Bruel; D. Bruncko; C. Brune; R. Buchholz; L. Büngener; J. Bürger; F. W. Büsser; A. Buniatian; S. Burke; M. J. Burton; D. Calvet; A. T. Campbell; T. Carli; M. Charlet; D. Clarke; A. B. Clegg; B. Clerbaux; S. Cocks; J. G. Contreras; C. Cormack; J. A. Coughlan; A. Courau; M.-C. Cousinou; G. Cozzika; L. Criegee; D. G. Cussans; J. Cvach; S. Dagoret; J. B. Dainton; W. D. Dau; K. Daum; M. David; C. L. Davis; B. Delcourt; A. De Roeck; E. A. De Wolf; M. Dirkmann; P. Dixon; P. Di Nezza; W. Dlugosz; C. Dollfus; K. T. Donovan; J. D. Dowell; H. B. Dreis; A. Droutskoi; O. Dünger; H. Duhm; J. Ebert; T. R. Ebert; G. Eckerlin; V. Efremenko; S. Egli; R. Eichler; F. Eisele; E. Eisenhandler; E. Elsen; M. Erdmann; W. Erdmann; A. B. Fahr; L. Favart; A. Fedotov; R. Felst; J. Feltesse; J. Ferencei; F. Ferrarotto; K. Flamm; M. Fleischer; M. Flieser; G. Flügge; A. Fomenko; J. Formánek; J. M. Foster; G. Franke; E. Fretwurst; E. Gabathuler; K. Gabathuler; F. Gaede; J. Garvey; J. Gayler; M. Gebauer; H. Genzel; R. Gerhards; A. Glazov; L. Goerlich; N. Gogitidze; M. Goldberg; D. Goldner; K. Golec-Biernat; B. Gonzalez-Pineiro; I. Gorelov; C. Grab; H. Grässler; T. Greenshaw; R. K. Griffiths; G. Grindhammer; A. Gruber; C. Gruber; T. Hadig; D. Haidt; L. Hajduk; T. Haller; M. Hampel; W. J. Haynes; B. Heinemann; G. Heinzelmann; R. C. W. Henderson; H. Henschel; I. Herynek; M. F. Hess; K. Hewitt; W. Hildesheim; K. H. Hiller; C. D. Hilton; J. Hladký; M. Höppner; D. Hoffmann; T. Holtom; R. Horisberger; V. L. Hudgson; M. Hütte; M. Ibbotson; H. Itterbeck; A. Jacholkowska; C. Jacobsson; M. Jaffre; J. Janoth; D. M. Jansen; T. Jansen; L. Jönsson; D. P. Johnson; H. Jung; P. I. P. Kalmus; M. Kander; D. Kant; R. Kaschowitz; U. Kathage; J. Katzy; H. H. Kaufmann; O. Kaufmann; M. Kausch; S. Kazarian; I. R. Kenyon; S. Kermiche; C. Keuker; C. Kiesling; M. Klein; C. Kleinwort; G. Knies; T. Köhler; J. H. Köhne; H. Kolanoski; S. D. Kolya; V. Korbel; P. Kostka; S. K. Kotelnikov; T. Krämerkämper; M. W. Krasny; H. Krehbiel; D. Krücker; H. Küster; M. Kuhlen; T. Kurca; J. Kurzhöfer; D. Lacour; B. Laforge; M. P. J. Landon; W. Lange; U. Langenegger; A. Lebedev; F. Lehner; S. Levonian; G. Lindström; M. Lindstroem; F. Linsel; J. Lipinski; B. List; G. Lobo; P. Loch; J. W. Lomas; G. C. Lopez; V. Lubimov; D. Liike; L. Lytkin; N. Magnussen; E. Malinovski; R. Maracek; P. Marage; J. Marks; R. Marshall; J. Martens; G. Martin; R. Martin; H.-U. Martyn; J. Martyniak; T. Mavroidis; S. J. Maxfield; S. J. McMahon; A. Mehta; K. Meier; F. Metlica; A. Meyer; H. Meyer; J. Meyer; P.-O. Meyer; A. Migliori; S. Mikocki; D. Milstead; J. Moeck; F. Moreau; J. V. Morris; E. Mroczko; D. Müller; G. Müller; K. Müller; P. Murín; V. Nagovizin; R. Nahnhauer; B. Naroska; Th. Naumann; I. Négri; P. R. Newman; D. Newton; H. K. Nguyen; T. C. Nicholls; F. Niebergall; C. Niebuhr; Ch. Niedzballa; H. Niggli; G. Nowak; G. W. Noyes; T. Nunnemann; M. Nyberg-Werther; M. Oakden; H. Oberlack; J. E. Olsson; D. Ozerov; P. Palmen; E. Panaro; A. Panitch; C. Pascaud; G. D. Patel; H. Pawletta; E. Peppel; E. Perez; J. P. Phillips; A. Pieuchot; D. Pitzl; G. Pope; B. Povh; S. Prell; K. Rabbertz; G. Rädel; P. Reimer; S. Reinshagen; H. Rick; F. Riepenhausen; S. Riess; E. Rizvi; P. Robmann; P. H. E. Roloff; R. Roosen; K. Rosenbauer; A. Rostovtsev; F. Rouse; C. Royon; K. Rüter; S. Rusakov; K. Rybicki; D. P. C. Sankey; P. Schacht; S. Schiek; S. Schleif; P. Schleper; W. von Schlippe; D. Schmidt; G. Schmidt; L. Schoeffel; A. Schöning; V. Schröder; E. Schuhmann; B. Schwab; F. Sefkow; R. Sell; A. Semenovy; V. Shekelyan; I. Sheviakov; L. N. Shtarkov; G. Siegmon; U. Siewert; Y. Sirois; I. O. Skillicorni; F Smirnov; V. Solochenko; Y. Soloviev; A. Specka; J. Spiekermann; S. Spielman; H. Spitzer; F. Squinabol; F Steffen; F. Steinberg; H. Steiner; J. Steinhart; B. Stella; A. Stellberger; P. J. Stier; J. Stiewe; U. Stößlein; K. Stolze; U. Straumann; W. Struczinski; J. P. Sutton; S. Tapprogge; V. Tchernyshov; S. Tchetchelnitski; J. Theissen; C. Thiebaux; G. Thompson; N. Tobien; R. Todenhagen; P. Truöl; G. Tsipolitis; J. Turnau; J. Tutas; E. Tzamariudaki; P. Uelkes; A. Usik; S. Valkár; A. Valkárová; C. Vallée; D. Vandenplas; P. Van Esch; P. Van Mechelen; Y. Vazdik; P. Verrecchia; G. Villet; K. Wacker; A. Wagener; M. Wagener; B. Waugh; G. Weber; M. Weber; D. Wegener; A. Wegner; T. Wengler; M. Werner; L. R. West; T. Wilksen; S. Willard; M. Winde; G.-G. Winter

    1997-01-01

    Transverse momentum spectra of charged particles produced in deep inelastic scattering are measured as a function of the kinematic variablesx and Q2 using the H1 detector at the epcollider HERA. The data are compared to different parton emission models, either with or without ordering of the emissions in transverse momentum. The data provide evidence for a relatively large amount of

  5. Do Gravity Waves Transport Angular Momentum away from Tropical Cyclones? YUMIN MOON AND DAVID S. NOLAN

    E-print Network

    Nolan, David S.

    Do Gravity Waves Transport Angular Momentum away from Tropical Cyclones? YUMIN MOON AND DAVID S that gravity waves can transport a significantly large amount of angular momentum away from tropical cyclones-water equations to model gravity waves radiating outward from rapidly rotating inner-core asymmetries. This issue

  6. External Influences on Hurricane Intensity. Part I: Outflow Layer Eddy Angular Momentum Fluxes

    Microsoft Academic Search

    John Molinari; David Vollaro

    1989-01-01

    Outflow layer winds were objectively analyzed every 12 h for 6 days during the life cycle of Hurricane Elena (1985). A high correlation was found between angular momentum fluxes by azimuthal eddies at large radii and central pressure changes in the storm 27-33 h later. Momentum flux by eddies exceeded that by the azimuthal mean outside the 800 km radius,

  7. 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.

  8. Behavioral economics and behavioral momentum

    PubMed Central

    Nevin, John A.

    1995-01-01

    Some relations between elasticity of demand and the conditions of reinforcement are reanalyzed in terms of resistance to change, in ways suggested by the metaphor of behavioral momentum; some relations between resistance to change and the conditions of reinforcement are reanalyzed in terms of elasticity of demand, in ways suggested by behavioral economics. In addition, some data on labor supply in relation to variable-ratio schedules and alternative reinforcement are reanalyzed in terms of resistance to change and compared with steady-state resistance data for performance on multiple and concurrent interval schedules. The results of these studies can be summarized by two functions based on the behavioral momentum approach, relating relative behavioral mass to relative reinforcement per response or per unit time. The former is a relation between relative unit price and relative behavioral mass, suggesting the possibility of convergent measurement of a theoretical construct common to both approaches. However, the momentum and economic approaches differ fundamentally on whether it is preferable to construe discriminated operant behavior as selected and strengthened by its consequences or as part of a behavior–consequence bundle that maximizes utility. PMID:16812775

  9. Extinction, Relapse, and Behavioral Momentum

    PubMed Central

    Podlesnik, Christopher A.; Shahan, Timothy A.

    2010-01-01

    Previous experiments on behavioral momentum have shown that relative resistance to extinction of operant behavior in the presence of a discriminative stimulus depends upon the baseline rate or magnitude of reinforcement associated with that stimulus (i.e., the Pavlovian stimulus-reinforcer relation). Recently, we have shown that relapse of operant behavior in reinstatement, resurgence, and context renewal preparations also is a function of baseline stimulus-reinforcer relations. In this paper we present new data examining the role of baseline stimulus-reinforcer relations on resistance to extinction and relapse using a variety of baseline training conditions and relapse operations. Furthermore, we evaluate the adequacy of a behavioral-momentum based model in accounting for the results. The model suggests that relapse occurs as a result of a decrease in the disruptive impact of extinction precipitated by a change in circumstances associated with extinction, and that the degree of relapse is a function of the pre-extinction baseline Pavlovian stimulus-reinforcer relation. Across experiments, relative resistance to extinction and relapse were greater in the presence of stimuli associated with more favorable conditions of reinforcement and were positively related to one another. In addition, the model did a good job in accounting for these effects. Thus, behavioral momentum theory may provide a useful quantitative approach for characterizing how differential reinforcement conditions contribute to relapse of operant behavior. PMID:20152889

  10. 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.

  11. Momentum Trading and Limits to Arbitrage 

    E-print Network

    Armstrong, William

    2012-07-16

    is unobservable. This dissertation studies the endogenous relationship between momentum trading and mispricing. The basic idea is that momentum trades can impede arbitrage when they are in the opposite direction of arbitrage trades and reinforce arbitrage when...

  12. Paraxial Light Beams with Angular Momentum

    E-print Network

    A. Bekshaev; M. Soskin; M. Vasnetsov

    2008-01-15

    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; Orbital angular momentum and the intensity moments; Symmetry breakdown and decomposition of the orbital angular momentum; Mechanical models of the vortex light beams; Mechanical action of the beam angular momentum; Rotational Doppler effect, its manifestation in the image rotation; Spectrum of helical harmonics and associated problems; Non-collinear rotational Doppler effect; Properties of a beam forcedly rotating around its own axis. Research prospects and ways of practical utilization of optical beams with angular momentum.

  13. 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.

  14. The effect of technology advancements on the comparative advantages of electric versus chemical propulsion for a large cargo orbit transfer vehicle

    NASA Technical Reports Server (NTRS)

    Rehder, J. J.; Wurster, K. E.

    1978-01-01

    Techniques for sizing electrically or chemically propelled orbit transfer vehicles and analyzing fleet requirements are used in a comparative analysis of the two concepts for various levels of traffic to geosynchronous orbit. The vehicle masses, fuel requirements, and fleet sizes are determined and translated into launch vehicle payload requirements. Technology projections beyond normal growth are made and their effect on the comparative advantages of the concepts is determined. A preliminary cost analysis indicates that although electric propulsion greatly reduces launch vehicle requirements substantial improvements in the cost and reusability of power systems must occur to make an electrically propelled vehicle competitive.

  15. Momentum Distribution and Contact of the Unitary Fermi gas

    E-print Network

    Drut, Joaquín E; Ten, Timour

    2010-01-01

    We calculate the momentum distribution of the Unitary Fermi Gas using Quantum Monte Carlo at finite temperature as well as in the ground state. At large momenta k/k_F, we find that the momentum distribution falls off as k^{-4}, in agreement with the Tan relations. From the momentum distribution, we determine the contact C as a function of T/\\epsilon_F and present a comparison with available theoretical analyses. At low T, we find that C increases with temperature, achieving a maximum around T/\\epsilon_F ~ 0.4. Our calculations are performed on lattices of spatial extent up to N_x = 12 with a particle number per unit volume of ~ 0.04 - 0.05, which corresponds to ~ 45 particles for N_x = 10 and ~ 75 particles for N_x = 12.

  16. Optical angular momentum in periodic arrays

    Microsoft Academic Search

    R. Zambrini; M. Vasnetsov; M. Dennis; J. Courtial

    2005-01-01

    This paper studies the optical angular momentum in periodic arrays. This work shows a gray-scale representation of the phase cross-section of a periodic array of optical vortices. The phase gradient gives rise to transverse linear momentum, which in turn leads to a nonvanishing angular momentum density.

  17. Angular Momentum Transport in Astrophysical Accretion Flows

    E-print Network

    Hammett, Greg

    Angular Momentum Transport in Astrophysical Accretion Flows Greg Hammett, Princeton Plasma Physics of matter onto a central object (generally w/ angular momentum) · Central to ­ Star & Planet Formation to Sgr A* #12;Outline · Accretion Disks: Basic Physical Picture · MHD of Disks: Angular Momentum

  18. ANGULAR MOMENTUM: AN APPROACH TO COMBINATORIAL SPACETIME

    E-print Network

    Baez, John

    ANGULAR MOMENTUM: AN APPROACH TO COMBINATORIAL SPACE­TIME ROGER PENROSE I want to describe an idea­time in a very intimate way, is in angular momentum. The idea here, then, is to start with the concept of angular momentum--- here one has a discrete spectrum---and use the rules for combining angular This paper

  19. Angular Momentum Decomposition for an Electron

    E-print Network

    Matthias Burkardt; Hikmat BC

    2008-12-09

    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.

  20. 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.