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1

Inclusive electron - nucleus scattering at large momentum transfer  

SciTech Connect

Inclusive electron scattering is measured with 4.045 GeV incident beam energy from C, Fe, and Au targets. The measured energy transfers and angles correspond to a kinematic range for Bjorken x>1 and momentum transfers from Q2 = 1-7 (GeV/c)2. When analyzed in terms of the y-scaling function the data show for the first time an approach to scaling for values of the initial nucleon momenta significantly greater than the nuclear matter Fermi momentum (i.e., >0.3 GeV/c).

J. Arrington; C. S. Armstrong; T. Averett; O. K. Baker; L. de Bever; C. W. Bochna; W. Boeglin; B. Bray; R. D. Carlini; G. Collins; C. Cothran; D. Crabb; D. Day; J. A. Dunne; D. Dutta; R. Ent; B. W. Filippone; A. Honegger; E. W. Hughes; J. Jensen; J. Jourdan; C. E. Keppel; D. M. Koltenuk; R. Lindgren; A. Lung; D. J. Mack; J. McCarthy; R. D. McKeown; D. Meekins; J. H. Mitchell; H. G. Mkrtchyan; G. Niculescu; I. Niculescu; T. Petitjean; O. Rondon; I. Sick; C. Smith; B. Terburg; W. F. Vulcan; S. A. Wood; C. Yan; J. Zhao; and B. Zihlmann

1999-03-01

2

Hadron-hadron elastic scattering at large momentum transfers  

SciTech Connect

Cross sections for ..pi../sup + -/p, K/sup + -/p and p/sup + -/p elastic scattering for incident momenta above a few tens of GeV/c and momentum transfers in the range 1 less than or equal to -t less than or equal to 10 (GeV/c)/sup 2/ have recently been measured. The data are reviewed, and compared with existing models of elastic scattering.

Rubinstein, R.

1983-05-01

3

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

NASA Astrophysics Data System (ADS)

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

Bulychev, Andrey A.; Kouzakov, Konstantin A.

2014-11-01

4

Electron impact ionization-excitation and double-ionization dynamics of He at large momentum transfer  

NASA Astrophysics Data System (ADS)

We report a collision dynamics study on electron-impact ionization-excitation and double-ionization of He at large momentum transfer. The symmetric noncoplanar (e,2e) and (e,3-1e) cross sections have been measured for transitions to the He+ n=2 excited state and He2+doubly ionized state at impact energies of 1.2, 2.1, and 4.3 keV. An investigation of impact energy dependence of the cross sections provides definite evidence that noticeable higher-order effects are involved even at the rather high impact energies used. It has been found that second Born approximation calculations satisfactorily account for the experimental results, indicating that the second-order two-step mechanisms play crucial roles in the ionization-excitation and double-ionization processes under the kinematical conditions considered here.

Watanabe, N.; Takahashi, M.

2009-11-01

5

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

SciTech Connect

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.

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

6

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

SciTech Connect

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.

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

7

Oscillation of the electron-density distribution in momentum space: An (e ,2 e ) study of H2 at large momentum transfer  

NASA Astrophysics Data System (ADS)

Bond oscillation, a phenomenon characteristic of the molecular electron-density distribution in momentum space, is demonstrated for the 1 ?g molecular orbital of H2 with an (e , 2 e ) experiment at large momentum transfer. Analysis of the experimental data in terms of two-center interference effects has revealed that different oscillatory structures can be observed, depending on the model for describing (e , 2 e ) ionization from the constituent H 1 s atomic orbitals. It is shown that bond oscillation is highly sensitive to the spatial pattern and chemical bonding nature of the molecular orbital.

Yamazaki, Masakazu; Satoh, Hironori; Watanabe, Noboru; Jones, Darryl B.; Takahashi, Masahiko

2014-11-01

8

(e,2e) and (e,3-1e) studies on double processes of He at large momentum transfer  

NASA Astrophysics Data System (ADS)

The double processes of He in electron-impact ionization, single ionization with simultaneous excitation and double ionization, have been studied at large momentum transfer using an energy- and momentum-dispersive binary (e,2e) spectrometer. The experiment has been performed at an impact energy of 2080eV in the symmetric noncoplanar geometry. In this way we have achieved a large momentum transfer of 9a.u. , a value that has never been realized so far for the study on double ionization. The measured (e,2e) and (e,3-1e) cross sections for transitions to the n=2 excited state of He+ and to doubly ionized He2+ are presented as normalized intensities relative to that to the n=1 ground state of He+ . The results are compared with first-order plane-wave impulse approximation (PWIA) calculations using various He ground-state wave functions. It is shown that shapes of the momentum-dependent (e,2e) and (e,3-1e) cross sections are well reproduced by the PWIA calculations only when highly correlated wave functions are employed. However, noticeable discrepancies between experiment and theory remain in magnitude for both the double processes, suggesting the importance of higher-order effects under the experimental conditions examined as well as of acquiring more complete knowledge of electron correlation in the target.

Watanabe, N.; Khajuria, Y.; Takahashi, M.; Udagawa, Y.; Vinitsky, P. S.; Popov, Yu. V.; Chuluunbaatar, O.; Kouzakov, K. A.

2005-09-01

9

Measurement of the running of the electromagnetic coupling at large momentum-transfer at LEP  

NASA Astrophysics Data System (ADS)

The evolution of the electromagnetic coupling, ?, in the momentum-transfer range 1800 GeV<-Q<21600 GeV is studied with about 40?000 Bhabha-scattering events collected with the L3 detector at LEP at centre-of-mass energies s=189 209 GeV. The running of ? is parametrised as: ?(Q)=?1-C??(Q), where ???(Q=0) is the fine-structure constant and C=1 corresponds to the evolution expected in QED. A fit to the differential cross section of the ee?ee process for scattering angles in the range |cos?|<0.9 excludes the hypothesis of a constant value of ?, C=0, and validates the QED prediction with the result: C=1.05±0.07±0.14, where the first uncertainty is statistical and the second systematic.

L3 Collaboration; Achard, P.; Adriani, O.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M. G.; Anderhub, H.; Andreev, V. P.; Anselmo, F.; Arefiev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S. V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillère, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J. J.; Blyth, S. C.; Bobbink, G. J.; Böhm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J. G.; Brochu, F.; Burger, J. D.; Burger, W. J.; Cai, X. D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y. H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de La Cruz, B.; Cucciarelli, S.; de Asmundis, R.; Déglon, P.; Debreczeni, J.; Degré, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; Denotaristefani, F.; de Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M. T.; Duchesneau, D.; Duda, M.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F. J.; Extermann, P.; Falagan, M. A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher, P. H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Yu.; Ganguli, S. N.; Garcia-Abia, P.; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z. F.; Grenier, G.; Grimm, O.; Gruenewald, M. W.; Guida, M.; Gupta, V. K.; Gurtu, A.; Gutay, L. J.; Haas, D.; Hatzifotiadou, D.; Hebbeker, T.; Hervé, A.; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S. R.; Jin, B. N.; Jindal, P.; Jones, L. W.; de Jong, P.; Josa-Mutuberría, I.; Kaur, M.; Kienzle-Focacci, M. N.; Kim, J. K.; Kirkby, J.; Kittel, W.; Klimentov, A.; König, A. C.; Kopal, M.; Koutsenko, V.; Kräber, M.; Kraemer, R. W.; Krüger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J. M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C. H.; Lin, W. T.; Linde, F. L.; Lista, L.; Liu, Z. A.; Lohmann, W.; Longo, E.; Lu, Y. S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W. G.; Malgeri, L.; Malinin, A.; Maña, C.; Mans, J.; Martin, J. P.; Marzano, F.; Mazumdar, K.; McNeil, R. R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W. J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G. B.; Muanza, G. S.; Muijs, A. J. M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Nowak, H.; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroué, P. A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofiev, D.; Rahal-Callot, G.; Rahaman, M. A.; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P. G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, K.; Roe, B. P.; Romero, L.; Rosca, A.; Rosemann, C.; Rosenbleck, C.; Rosier-Lees, S.; Roth, S.; Rubio, J. A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schäfer, C.; Schegelsky, V.; Schopper, H.; Schotanus, D. J.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D. P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L. Z.; Sushkov, S.; Suter, H.; Swain, J. D.; Szillasi, Z.; Tang, X. W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, C.; Ting, Samuel C. C.; Ting, S. M.; Tonwar, S. C.; Tóth, J.; Tully, C.; Tung, K. L.; Ulbricht, J.; Valente, E.; van de Walle, R. T.; Vasquez, R.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobiev, I.; Vorobyov, A. A.; Wadhwa, M.; Wang, Q.; Wang, X. L.; Wang, Z. M.; Weber, M.; Wynhoff, S.; Xia, L.; Xu, Z. Z.; Yamamoto, J.; Yang, B. Z.; Yang, C. G.; Yang, H. J.; Yang, M.; Yeh, S. C.; Zalite, An.; Zalite, Yu.; Zhang, Z. P.; Zhao, J.; Zhu, G. Y.; Zhu, R. Y.; Zhuang, H. L.; Zichichi, A.; Zimmermann, B.; Zöller, M.

2005-09-01

10

Measurement of the running of the electromagnetic coupling at large momentum-transfer at LEP  

NASA Astrophysics Data System (ADS)

The evolution of the electromagnetic coupling, ?, in the momentum-transfer range 1800 GeV2 < -Q2 < 21600 GeV2 is studied with about 40 000 Bhabha-scattering events collected with the L3 detector at LEP at centre-of-mass energies ?{ s} = 189- 209 GeV. The running of ? is parametrised as: ?(Q2) = ?0/1 - C?? (Q2), where ?0 ? ? (Q2 = 0) is the fine-structure constant and C = 1 corresponds to the evolution expected in QED. A fit to the differential cross section of the e+e- ?e+e- process for scattering angles in the range | cos? | < 0.9 excludes the hypothesis of a constant value of ?, C = 0, and validates the QED prediction with the result: C = 1.05 ± 0.07 ± 0.14 , where the first uncertainty is statistical and the second systematic.

Achard, P.; Adriani, O.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M. G.; Anderhub, H.; Andreev, V. P.; Anselmo, F.; Arefiev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S. V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillère, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J. J.; Blyth, S. C.; Bobbink, G. J.; Böhm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J. G.; Brochu, F.; Burger, J. D.; Burger, W. J.; Cai, X. D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y. H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de la Cruz, B.; Cucciarelli, S.; de Asmundis, R.; Déglon, P.; Debreczeni, J.; Degré, A.; Dehmelt, K.; Deiters, K.; della Volpe, D.; Delmeire, E.; Denes, P.; DeNotaristefani, F.; De Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M. T.; Duchesneau, D.; Duda, M.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F. J.; Extermann, P.; Falagan, M. A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher, P. H.; Fisher, W.; Fisk, I.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Yu.; Ganguli, S. N.; Garcia-Abia, P.; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z. F.; Grenier, G.; Grimm, O.; Gruenewald, M. W.; Guida, M.; Gupta, V. K.; Gurtu, A.; Gutay, L. J.; Haas, D.; Hatzifotiadou, D.; Hebbeker, T.; Hervé, A.; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S. R.; Jin, B. N.; Jindal, P.; Jones, L. W.; de Jong, P.; Josa-Mutuberría, I.; Kaur, M.; Kienzle-Focacci, M. N.; Kim, J. K.; Kirkby, J.; Kittel, W.; Klimentov, A.; König, A. C.; Kopal, M.; Koutsenko, V.; Kräber, M.; Kraemer, R. W.; Krüger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J. M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C. H.; Lin, W. T.; Linde, F. L.; Lista, L.; Liu, Z. A.; Lohmann, W.; Longo, E.; Lu, Y. S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W. G.; Malgeri, L.; Malinin, A.; Maña, C.; Mans, J.; Martin, J. P.; Marzano, F.; Mazumdar, K.; McNeil, R. R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W. J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G. B.; Muanza, G. S.; Muijs, A. J. M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Nowak, H.; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Piccolo, D.; Pierella, F.; Pioppi, M.; Piroué, P. A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofiev, D.; Rahal-Callot, G.; Rahaman, M. A.; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P. G.; Ranieri, R.; Raspereza, A.; Razis, P.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, K.; Roe, B. P.; Romero, L.; Rosca, A.; Rosemann, C.; Rosenbleck, C.; Rosier-Lees, S.; Roth, S.; Rubio, J. A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schäfer, C.; Schegelsky, V.; Schopper, H.; Schotanus, D. J.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D. P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L. Z.; Sushkov, S.; Suter, H.; Swain, J. D.; Szillasi, Z.; Tang, X. W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, C.; Ting, Samuel C. C.; Ting, S. M.; Tonwar, S. C.; Tóth, J.; Tully, C.; Tung, K. L.; Ulbricht, J.; Valente, E.; Van de Walle, R. T.; Vasquez, R.; Veszpremi, V.; Vesztergombi, G.; Vetlitsky, I.; Viertel, G.; Villa, S.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobiev, I.; Vorobyov, A. A.; Wadhwa, M.; Wang, Q.; Wang, X. L.; Wang, Z. M.; Weber, M.; Wynhoff, S.; Xia, L.; Xu, Z. Z.; Yamamoto, J.; Yang, B. Z.; Yang, C. G.; Yang, H. J.; Yang, M.; Yeh, S. C.; Zalite, An.; Zalite, Yu.; Zhang, Z. P.; Zhao, J.; Zhu, G. Y.; Zhu, R. Y.; Zhuang, H. L.; Zichichi, A.; Zimmermann, B.; Zöller, M.; L3 Collaboration

2005-09-01

11

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

SciTech Connect

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.

Riad Suleiman

1999-10-01

12

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

E-print Network

PHYSICAL REVIEW D 1 JANUARY 1998VOLUME 57, NUMBER 1Measurements of the meson-photon transition form factors of light pseudoscalar mesons at large momentum transfer J. Gronberg, T. S. Hill, R. Kutschke, D. J. Lange, S. Menary, R. J. Morrison, H. N.... Nelson, T. K. Nelson, C. Qiao, J. D. Richman, D. Roberts, A. Ryd, and M. S. Witherell University of California, Santa Barbara, California 93106 R. Balest, B. H. Behrens, W. T. Ford, H. Park, J. Roy, and J. G. Smith University of Colorado, Boulder...

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

1998-01-01

13

Electron-impact ionization of the water molecule at large momentum transfer above the double-ionization threshold  

NASA Astrophysics Data System (ADS)

The single and double ionization of the water molecule at large momentum transfer has been studied using a combination of (e,2e) and (e,3-1e) spectroscopy, with the binding energy spectrum being measured from 0 to 100 eV. The experiment has been performed in the symmetric noncoplanar geometry at an incident electron energy of 2055 eV. In this way we have achieved a large momentum transfer of 9 a.u. In particular, we present an observation of a relatively intense band at around 58 eV. Symmetry-adapted cluster configuration interaction (SAC-CI) general-R calculations for single ionization indicate that the observed band is at least partly generated by a cluster of satellites with small intensities, which predominantly belong to states possessing 2A1 symmetry originating from the mixing of the (2a1)-1 state with two electron processes. Nevertheless, it has been found that the entire spectrum above the lowest double-ionization threshold cannot be understood, even qualitatively, with the SAC-CI calculations. This result suggests that the (e,3-1e) double-ionization processes have a significant contribution to the observations.

Jones, D. B.; Yamazaki, M.; Watanabe, N.; Takahashi, M.

2011-01-01

14

Momentum transfer from oblique impacts  

NASA Technical Reports Server (NTRS)

A completely satisfactory experiment would be in a low gravity environment where the effect of momentum imparted by ejecta impacting the surface can be removed or controlled from momentum transfer during impact. Preliminary estimates can be made using a ballistic pendulum. Such experiments were initiated at the NASA-Ames Vertical Gun Range in order to examine momentum transfer due to impact vaporization for oblique impacts. The preliminary results indicate that momentum from oblique impacts is very inefficient: decreasing with increasing impact velocity and perhaps size; increasing with decreasing density; and increasing with increasing impact angle. At face value, such results minimize the effect of momentum transfer by grazing impact; the more probable impact angles of 30 deg would have a greater effect, contrary to the commonly held impression.

Schultz, Peter H.; Gault, Donald E.

1987-01-01

15

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

PubMed

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

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

2013-01-11

16

Possibility to study color transparency in the large momentum transfer exclusive 2H(p,2p)n reaction  

NASA Astrophysics Data System (ADS)

The deuteron disintegration at high energies and large angles in the d(p,2p)n reaction is calculated in kinematic conditions where the dominant contributions are due to soft rescatterings of the initial and final nucleons, which accompany the hard pp reaction. The eikonal approximation, which accounts for relativistic kinematics as dictated by Feynman diagrams, reveals the important role played by the initial and final state interactions in the angular and momentum dependences of the differential cross section. Based on these results, we propose a new and effective test, at moderate energies, of the physics relevant for the color transparency phenomenon in hadron-initiated exclusive hard processes.

Frankfurt, L. L.; Piasetzky, E.; Sargsian, M. M.; Strikman, M. I.

1997-11-01

17

Measurement of event shapes at large momentum transfer with the ATLAS detector in pp collisions at sqrt{{s}}=7 TeV  

NASA Astrophysics Data System (ADS)

A measurement of event shape variables is presented for large momentum transfer proton-proton collisions using the ATLAS detector at the Large Hadron Collider. Six event shape variables calculated using hadronic jets are studied in inclusive multi-jet events in 35 pb-1 of integrated luminosity at a center-of-mass energy of sqrt{s} = 7 TeV. These measurements are compared to predictions by three Monte Carlo event generators containing leading-logarithmic parton showers matched to leading order matrix elements for 2?2 and 2? n ( n=2,…,6) scattering. Measurements of the third-jet resolution parameter, aplanarity, thrust, sphericity, and transverse sphericity are generally well described. The mean value of each event shape variable is evaluated as a function of the average momentum of the two leading jets p T,1 and p T,2, with a mean p T approaching 1 TeV.

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

2012-11-01

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)

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.

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

2014-03-01

19

Ultrafast angular momentum transfer in multisublattice ferrimagnets.  

PubMed

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

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

2014-01-01

20

On the Possibility to Study Color Transparency in the Large Momentum Transfer Exclusive $d(p,2p)n$ Reaction  

E-print Network

The deuteron disintegration at high energies and large angles in the $d(p,2p)n$ reaction, is calculated in kinematical conditions where the dominant contributions are due to soft rescatterings of the initial and final nucleons, which accompany the hard $pp$ reaction. The eikonal approximation, which accounts for relativistic kinematics as dictated by Feynman diagrams, reveals the important role played by the initial and final state interactions in the angular and momentum dependences of the differential cross section. Based on these results, we propose a new and effective test, at moderate energies, of the physics relevant for the color transparency phenomenon in hadron-initiated exclusive hard processes.

Frankfurt, L L; Sargsian, M M; Strikman, M I

1996-01-01

21

On the Possibility to Study Color Transparency in the Large Momentum Transfer Exclusive $d(p,2p)n$ Reaction  

E-print Network

The deuteron disintegration at high energies and large angles in the $d(p,2p)n$ reaction, is calculated in kinematical conditions where the dominant contributions are due to soft rescatterings of the initial and final nucleons, which accompany the hard $pp$ reaction. The eikonal approximation, which accounts for relativistic kinematics as dictated by Feynman diagrams, reveals the important role played by the initial and final state interactions in the angular and momentum dependences of the differential cross section. Based on these results, we propose a new and effective test, at moderate energies, of the physics relevant for the color transparency phenomenon in hadron-initiated exclusive hard processes.

L. L. Frankfurt; E. Piasetzky; M. M. Sargsian; M. I. Strikman

1996-07-22

22

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

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.

Aidan Kelleher

2010-10-01

23

Polarisation Transfer in Proton Compton Scattering at High Momentum Transfer  

SciTech Connect

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.

David Hamilton

2004-12-31

24

Energy Transfer in a Three Body Momentum Exchange Impact Damper  

Microsoft Academic Search

Impact vibration such as a floor vibration caused by jumping of children or vibration of a press machine is very important engineering problem. The momentum exchange impact damper has been proposed to solve these problems. The basic principle of this damper is based on the energy transfer on collision of three body systems. However energy or momentum transfer at the

Lovely Son; Hiroshi Matsuhisa; Hideo Utsuno

2008-01-01

25

Ion momentum and energy transfer rates for charge exchange collisions  

NASA Technical Reports Server (NTRS)

The rates of momentum and energy transfer have been obtained for charge exchange collisions between ion and neutral gases having arbitrary Maxwellian temperatures and bulk transport velocities. The results are directly applicable to the F-region of the ionosphere where 0+ - 0 charge is the dominant mechanism affecting ion momentum and energy transfer.

Horwitz, J.; Banks, P. M.

1973-01-01

26

Photoinduced spin angular momentum transfer into an antiferromagnetic insulator  

NASA Astrophysics Data System (ADS)

Spin angular momentum transfer into an antiferromagnetic (AFM) insulator is observed in a single-crystalline Fe/CoO/MgO(001) heterostructure by time-resolved magneto-optical Kerr effect. The transfer process is mediated by the Heisenberg exchange coupling between Fe and CoO spins. Spin angular momentum transfer to ordered AFM spins is independent of the external magnetic field and enhances the spin precession damping in Fe, which remains nearly invariant with temperature.

Fan, Y.; Ma, X.; Fang, F.; Zhu, J.; Li, Q.; Ma, T. P.; Wu, Y. Z.; Chen, Z. H.; Zhao, H. B.; Lüpke, G.

2014-03-01

27

Optical momentum transfer to macroscopic media  

E-print Network

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

Kemp, Brandon Alden, 1975-

2007-01-01

28

Energy Transfer in a Three Body Momentum Exchange Impact Damper  

NASA Astrophysics Data System (ADS)

Impact vibration such as a floor vibration caused by jumping of children or vibration of a press machine is very important engineering problem. The momentum exchange impact damper has been proposed to solve these problems. The basic principle of this damper is based on the energy transfer on collision of three body systems. However energy or momentum transfer at the impact is not explained theoretically. This paper considers the energy transfer incurred during collisions in three body systems. The three body systems considered herein consists of an impact mass, a main body and an absorber mass. When the impact mass collides with the main body, part of its kinetic energy is transferred to the main body. When the main body simultaneously collides with the absorber mass, part of the kinetic energy of the main body is transferred to the absorber mass. Consequently, the main body receives a small amount of shock and it is possible to keep the main body nearly stationary. In this study, the influence of contact frequency and natural frequency of the system on the energy transfer during collision is analyzed. A theoretical model is developed to analyze the effect of various system parameters. It is shown that the maximum transfer of energy that can be obtained occurs when the contact frequencies are the same. The theoretical analysis is validated with experimental results.

Son, Lovely; Matsuhisa, Hiroshi; Utsuno, Hideo

29

Momentum Transfer in a Spinning Fuel Tank Filled with Xenon  

NASA Technical Reports Server (NTRS)

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

Peugeot, John W.; Dorney, Daniel J.

2006-01-01

30

Mathematical models of momentum transfer in the boundary layer  

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

31

Effects of Floodplain Vegetation on Momentum Transfer in Compound Channel  

NASA Astrophysics Data System (ADS)

Better management of riparian vegetation for flood control and environmental preservation requires in-depth understanding of flow characteristics in the presence of vegetation. This study aims at clarifying the flow structure and lateral momentum transfer process in vegetated compound channels through experiments and numerical simulations. Two types of vegetation zone on a floodplain are discussed. In the first case a floodplain is fully covered by vegetation. In the other case a floodplain has a belt of vegetation zone along the interface between main channel and floodplain. The measured data are compared with the numerical results that are obtained using a non-linear k-? model and a vegetation model. It is found that the numerical model can reproduce the main characteristics of the flow and that the convection and the turbulent diffusion play important roles in the lateral momentum transfer across the interface between vegetated floodplain and main channel.

Hasegawa, Fumiaki; Yamamoto, Takuya; Jahra, Fatima; Kawahara, Yoshihisa

32

Atom interferometry with up to 24-photon-momentum-transfer beam splitters.  

PubMed

We present up to 24-photon Bragg diffraction as a beam splitter in light-pulse atom interferometers to achieve the largest splitting in momentum space so far. Relative to the 2-photon processes used in the most sensitive present interferometers, these large momentum transfer beam splitters increase the phase shift 12-fold for Mach-Zehnder (MZ) and 144-fold for Ramsey-Bordé (RB) geometries. We achieve a high visibility of the interference fringes (up to 52% for MZ or 36% for RB) and long pulse separation times that are possible only in atomic fountain setups. As the atom's internal state is not changed, important systematic effects can cancel. PMID:18518355

Müller, Holger; Chiow, Sheng-wey; Long, Quan; Herrmann, Sven; Chu, Steven

2008-05-01

33

Atom Interferometry with up to 24-Photon-Momentum-Transfer Beam Splitters  

NASA Astrophysics Data System (ADS)

We present up to 24-photon Bragg diffraction as a beam splitter in light-pulse atom interferometers to achieve the largest splitting in momentum space so far. Relative to the 2-photon processes used in the most sensitive present interferometers, these large momentum transfer beam splitters increase the phase shift 12-fold for Mach-Zehnder (MZ) and 144-fold for Ramsey-Bordé (RB) geometries. We achieve a high visibility of the interference fringes (up to 52% for MZ or 36% for RB) and long pulse separation times that are possible only in atomic fountain setups. As the atom’s internal state is not changed, important systematic effects can cancel.

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

2008-05-01

34

Parton physics from large-momentum effective field theory  

NASA Astrophysics Data System (ADS)

Parton physics, when formulated as light-front correlations, are difficult to study non-perturbatively, despite the promise of light-front quantization. Recently an alternative approach to partons have been proposed by re-visiting original Feynman picture of a hadron moving at asymptotically large momentum. Here I formulate the approach in the language of an effective field theory for a large hadron momentum P in lattice QCD, LaMET for short. I show that using this new effective theory, parton properties, including light-front parton wave functions, can be extracted from lattice observables in a systematic expansion of 1/P, much like that the parton distributions can be extracted from the hard scattering data at momentum scales of a few GeV.

Ji, XiangDong

2014-05-01

35

Parton physics from large-momentum effective field theory  

NASA Astrophysics Data System (ADS)

Parton physics, when formulated as light-front correlations, are difficult to study non-perturbatively, despite the promise of light-front quantization. Recently an alternative approach to partons have been proposed by re-visiting original Feynman picture of a hadron moving at asymptotically large momentum. Here I formulate the approach in the language of an effective field theory for a large hadron momentum P in lattice QCD, LaMET for short. I show that using this new effective theory, parton properties, including light-front parton wave functions, can be extracted from lattice observables in a systematic expansion of 1/ P, much like that the parton distributions can be extracted from the hard scattering data at momentum scales of a few GeV.

Ji, XiangDong

2014-07-01

36

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

NASA Astrophysics Data System (ADS)

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

Acharya, Hari

37

An optical model description of momentum transfer in heavy ion collisions  

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

38

Evidence for unmediated momentum transfer between light waves  

NASA Astrophysics Data System (ADS)

Dowling and Gea-Benacloche (1992) proved mathematically that "...under certain circumstances, it is possible to consistently interpret interference as the specular reflection of two electromagnetic waves off each other..." Combining experiment, model, and logic, we confirm this statement. Contrary to the supposition that electromagnetic waves/photons cannot interact, it is possible to interpret the results to indicate that identical out-of-phase waves and opposite polarity photons repel or, at least, cannot pass through each other. No energy is detected in the dark/null zones of wave interference. Because energy appears to be absent, the exchange of momentum through the null zone must redirect/repel light waves into bright zones. Our Zero-Slit Experiment (ZSX) provides diffraction-free interference in air between two portions of a divided laser beam. This experiment was initially an attempt to completely cancel a section of these two beams by recombining them in air when they are 180° out-of-phase. We have reduced interference patterns close to a double-bright zone (with 3 null zones), but no further. Within the limits of laser-beam spreading, we have studied the resulting interference patterns and compared them with models of collision between identical particles. It may be possible to distinguish light from other Bosons, if the model of opposite phases repelling is valid. An EM field-line model of the photon is presented to explain the interactions needed to produce momentum transfer.

Hudgins, W. R.; Meulenberg, A.; Ramadass, S.

2011-09-01

39

Deuteron-proton charge exchange reaction at small transfer momentum  

E-print Network

The charge-exchange reaction pd -> npp at 1 GeV projectile proton energy is studied. This reaction is considered in a special kinematics, when the transfer momentum from the beam proton to fast outgoing neutron is close to zero. Our approach is based on the Alt-Grassberger-Sandhas formulation of the multiple-scattering theory for the three-nucleon system. The matrix inversion method has been applied to take account of the final state interaction (FSI) contributions. The differential cross section, tensor analyzing power $C_{0,yy}$, vector-vector $C_{y,y}$ and vector-tensor $C_{y,xz}$ spin correlation parameters of the initial particles are presented. It is shown, that the FSI effects play a very important role under such kinematical conditions. The high sensitivity of the considered observables to the elementary nucleon-nucleon amplitudes has been obtained.

N. B. Ladygina; A. V. Shebeko

2004-11-17

40

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

PubMed

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

López-Caballero, Miguel; Burguete, Javier

2013-03-22

41

ANGULAR MOMENTUM TRANSFER IN VELA-LIKE PULSAR GLITCHES  

SciTech Connect

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

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

2011-12-10

42

Proton Spin Sum Rule from Large Momentum Effective Field Theory  

NASA Astrophysics Data System (ADS)

In high energy scattering experiments, the proton spin is understood as the sum of the spin and orbital angular momentum of the quarks and gluons in Feynman's parton picture. The Jaffe-Manohar form of the proton spin sum rule is justified as physical, and it is shown that the individual terms can be related to the proton matrix elements of certain quasi-obervables through a large momentum effective field theory. The relation is expressed as a factorization formula where the leading contribution to the quasi-observable is factorized into the parton observables and perturbative matching coefficients, and we present the results for the latter at one-loop order in perturbation theory. This will provide us with the basis to extract the proton spin content from the lattice QCD calculations of the quasi-observables.

Zhao, Yong; Ji, Xiangdong; Zhang, Jian-Hui

2015-01-01

43

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

SciTech Connect

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

Andrew Puckett

2010-02-01

44

Electromagnetic processes at low momentum transfer : a review for users  

NASA Astrophysics Data System (ADS)

Electromagnetic processes at low momentum transfer are often sources of background in many experiments. To be removed these effects must be calculated by the experimentalist, who must have a good knowledge of the validity of the theoretical formulas that he must use. Then we thought that it will be useful to prepare this review whose presentation is such that it should allow everyone to appreciate the accuracy of formulas that he must use in very complex situations. In this paper, we examine the problem related to bremsstrahlung, pair production and radiative corrections. The first part is devoted to kinematic and to the methods used to establish the corresponding cross sections. Les phénomènes électromagnétiques à faible transfert d'impulsion interviennent dans de nombreuses expériences comme des phénomènes parasites. Pour les éliminer, l'expérimentateur doit les calculer, mais il connait généralement mal la validité des formules théoriques qu'il doit alors utiliser. Il nous a donc paru utile de faire une revue dont la présentation doit permettre à chacun d'apprécier la précision des formules qu'il doit appliquer dans des situations très souvent complexes. Dans cet article, nous faisons le point, tant pour la théorie que pour l'expérience, en ce qui concerne : le rayonnement de freinage, la production de paires et les corrections radiatives. La première partie est consacrée à la cinématique des processus appréciés et aux méthodes permettant d'établir les sections efficaces correspondantes.

Parizet, M. J.; Borie, E.; Grossetête, B.; Isabelle, D. B.; Proriol, J.

45

Hypervelocity penetration modeling: momentum vs. energy and energy transfer mechanisms  

Microsoft Academic Search

Analytic penetration modeling usually relies on either a momentum balance or an energy-rate balance to predict depth of penetration by a penetrator based on initial geometry and impact velocity. In recent years, fairly sophisticated models of penetration have arisen that develop the three-dimensional flow field within a target. Based on the flow field and constitutive assumptions, it is then possible

James D. Walker

2001-01-01

46

Energy dissipation and angular momentum transfer within a magnetically torqued accretion disc  

NASA Astrophysics Data System (ADS)

We discuss transportation and redistribution of energy and angular momentum in the magnetic connection (MC) process and Blandford-Payne (BP) process. MC results in readjusting the interior viscous torque, and its effects are operative not only in but also beyond the MC region. The BP process is invoked to transfer the “excessive” angular momentum from an accretion disc. In addition, we derive a criterion for the interior viscous torque to resolve the puzzle of the overall equilibrium of angular momentum in disc accretion. It turns out that the efficiency of BP at extracting angular momentum and the intensity of the outflow are required to be greater than some critical values.

Gan, Zhaoming; Wang, Dingxiong; Lei, Weihua; Li, Yang

2010-01-01

47

Momentum transfer in asteroid impacts. I. Theory and scaling  

NASA Astrophysics Data System (ADS)

When an asteroid experiences an impact, its path is changed. How much it changes is important to know for both asteroid evolution studies and for attempts to prevent an asteroid from impacting the Earth. In an impact process the total momentum of the material is conserved. However, not all of the material is of interest, but only that remaining with the asteroid. The ratio of the change of momentum of the remaining asteroid to that of the impactor is called the momentum multiplication factor; and is commonly given the symbol ?. It has been known for some time that ? can be greater than unity, and in some cases far greater. That could be a significant factor in attempts to deflect an asteroid with an impact, and can also be important in the stirring of objects in the asteroid belt due to mutual impacts. The escaping crater ejecta are the source of the momentum multiplication. Housen and Holsapple (Housen, K.R., Holsapple, K.A. [2011a]. Icarus 211, 856-875) have given a recent summary of ejecta characteristics and scaling. Here we use those ejecta results to determine how ? depends on the impactor properties, on the asteroid size and composition, and establish the paths and time of flight of all of the ejecta particles. The approach is to add the contribution of each element of ejected mass accounting for its initial velocity, its trajectory and whether it escapes the asteroid. The goal in this paper is to provide a theoretical framework of the fundamental results which can be used as a test of the veracity of experiments and detailed numerical calculations of impacts. A subsequent paper will present direct laboratory results and numerical simulations of momentum multiplication in various geological materials.

Holsapple, Keith A.; Housen, Kevin R.

2012-11-01

48

W production at large transverse momentum at the CERN Large Hadron Collider.  

PubMed

We study the production of W bosons at large transverse momentum in pp collisions at the CERN Large Hadron Collider. We calculate the complete next-to-leading order (NLO) corrections to the differential cross section. We find that the NLO corrections provide a large increase to the cross section but, surprisingly, do not reduce the scale dependence relative to leading order (LO). We also calculate next-to-next-to-leading-order (NNLO) soft-gluon corrections and find that, although they are small, they significantly reduce the scale dependence thus providing a more stable result. PMID:16384211

Gonsalves, Richard J; Kidonakis, Nikolaos; Sabio Vera, Agustín

2005-11-25

49

Electron Transfer for Large Molecules through Delocalization  

SciTech Connect

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

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

2012-01-01

50

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

E-print Network

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

Shugo Yasuda; Ryoichi Yamamoto

2014-07-16

51

Design and development of an optical scanning mechanism (OSMA) with minimum momentum transfer  

NASA Technical Reports Server (NTRS)

The development model for an optical scanning mechanism assembly is described as being two equal inertial masses which collide with each other to minimize the momentum transfer to the satellite and other mounted instruments. The design criteria for the mirror, the compensating inertia structure and other components are given. The details of the design are discussed and related test results are presented, which show the validity of the design concept for momentum compensation.

Sainz, L. B. F.; Herrera, E.; Bajo, J. M.; Mallard, H. J.

1981-01-01

52

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

E-print Network

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

S. Pfalzner

2003-10-27

53

Real Compton Scattering on Proton at High Momentum Transfers  

SciTech Connect

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.

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

2005-06-01

54

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

E-print Network

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 it with 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 is part of 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.

Manuel Donaire; Bart van Tiggelen; Geert Rikken

2014-04-23

55

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

E-print Network

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

V. A. Bednyakov; F. Simkovic

2006-08-09

56

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

NASA Technical Reports Server (NTRS)

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

Boss, A. P.

1984-01-01

57

Measuring the Quantum State of a Large Angular Momentum  

E-print Network

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

Gerd Klose; Greg Smith; Poul S. Jessen

2001-01-03

58

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

E-print Network

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

Montfrooij, Wouter

59

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

Microsoft Academic Search

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

Mari Nakamura; Edmund Y. S. Chao

2003-01-01

60

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

Microsoft Academic Search

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

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

1995-01-01

61

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

SciTech Connect

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.

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

1995-12-31

62

Investigation into the momentum transfer between an impacting raindrop and a granular bed using 3-dimensional particle tracking  

NASA Astrophysics Data System (ADS)

The transportation of soil particles through the process of raindrop impact is a significant mechanism within the process of soil erosion. However, even though splash transport has received considerable attention over the years, little is still known about the transfer of momentum between raindrops and soil particles, with only a few recent studies investigating the fundamental interactions involved. The work presented in this study examines the interaction that occurs between an impacting water droplet and a bed of loose, graded sand, with the aim of providing further insight into the transfer of energy between them. The study focuses on quantifying the ejection of particles from the bed through momentum transfer and the resultant change in the morphology of the bed caused by the impact. The nature of the interaction that occurs between the water and the sand is defined by a large number of variables such as droplet size, impact velocity, fluid viscosity, surface tension, grain size, grain shape and packing density. However, for this study, all of these variables are kept as constant as possible, with multiple runs made of the same individual interaction, in order to examine the complexity and variability of the event. To investigate the interaction that occurs, three different techniques are used: i) High speed imaging of the interaction, looking at the dynamics of both the water and the sand ii) Three dimensional, time resolved particle tracking of the grains ejected from the sand bed during the event iii) Surface profiling of the crater produced by the impact and the large clumps of sand transported from the crater edge. The data produced demonstrates that, for example, for a 3.7-mm raindrop impacting a 150-160 µm sand bed at 6.2 m/s, only approximately 2% of the momentum of the rain drop gets transferred to the ballistic ejection of dry sand particles from the crater edge. The small amount of momentum transferred explains why the large amounts of energy present in rainstorms cause only a small proportion of total soil erosion by water processes.

Long, Edward; Hargrave, Graham; Cooper, James; Kitchener, Benjamin; Parsons, Anthony; Hewett, Caspar; Wainwright, John

2013-04-01

63

Density matrix reconstruction of a large angular momentum  

NASA Astrophysics Data System (ADS)

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.

Klose, Gerd

2001-10-01

64

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

SciTech Connect

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

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

2006-11-15

65

Optical Vortices with Large Orbital Momentum: Generation and Interference  

NASA Technical Reports Server (NTRS)

We demonstrate a method for generation of beams of light with large angular momenta. The method utilizes whispering gallery mode resonators that transform a plane electromagnetic wave into high order Bessel beams. Interference pattern among the beams as well as shadow pictures induced by the beams are observed and studied.

Savchenkov, Anatoliy A.; Matsko, Andrey B.; Grudinin, Ivan; Savchenkova, Ekaterina A.; Strekalov, Dmitry; Maleki, Lute

2006-01-01

66

Densification of functional plasma polymers by momentum transfer during film growth  

SciTech Connect

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

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

2012-11-19

67

Study of deuteron-proton charge exchange reaction at small transfer momentum  

E-print Network

The charge-exchange reaction pd->npp at 1 GeV projectile proton energy is studied in the multiple-scattering expansion technique. This reaction is considered in a special kinematics, when the transfer momentum from the beam proton to fast neutron is close to zero. The differential cross section and a set of polarization observables are calculated. It was shown that contribution of the final state interaction between two protons is very significant.

N. B. Ladygina; A. V. Shebeko

2004-04-15

68

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

Microsoft Academic Search

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

Gabriel Katul; Davide Poggi; Daniela Cava; John Finnigan

2006-01-01

69

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

PubMed Central

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

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

2011-01-01

70

Higher-Twist Dynamics in Large Transverse Momentum Hadron Production  

SciTech Connect

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

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

2009-12-17

71

Optimal Shape Design of Compact Heat Exchangers Based on Adjoint Analysis of Momentum and Heat Transfer  

NASA Astrophysics Data System (ADS)

An adjoint-based shape optimization method of heat exchangers, which takes into account the heat transfer performance with the pressure loss penalty, is proposed, and its effectiveness is examined through a series of numerical simulation. Undulated heat transfer surface is optimized under an isothermal heated condition based on the variational method with the first derivative of the cost function, which is determined by an adjoint analysis of momentum and heat transfer. When applied to a modeled heat-exchanger passage with a pair of oblique wavy walls, the present optimization method refines the duct shape so as to enhance the heat transfer while suppressing the flow separation. It is shown that the j/f factor is further increased by 4% from the best value of the initial obliquely wavy duct. The effects of the initial wave amplitude upon the shape evolution process are also investigated.

Morimoto, Kenichi; Suzuki, Yuji; Kasagi, Nobuhide

72

Improved transverse (e,e{sup '}) response function of {sup 3}He at intermediate momentum transfers  

SciTech Connect

The transverse electron scattering response function of {sup 3}He is studied in the quasielastic peak region for momentum transfers between 500 and 700 MeV/c. A conventional description of the process leads to results that vary substantially from experiment. To improve the results, the present calculation is done in a reference frame [the active nucleon Breit (ANB) frame] that diminishes the influence of relativistic effects on nuclear states. The laboratory frame response function is then obtained via a kinematics transformation. In addition, a one-body nuclear current operator is employed that includes all leading-order relativistic corrections. Multipoles of this operator are listed. It is shown that the use of the ANB frame leads to a sizable shift in the quasielastic peak to lower energy and, contrary to the relativistic current, also to an increase in the peak height. The additionally considered meson exchange current contribution is quite small in the peak region. In comparison with experiment, there is excellent agreement of the peak positions. The peak height agrees well with experiment for the lowest considered momentum transfer (500 MeV/c) but tends to be too high for higher momentum transfer (10% at 700 MeV/c).

Efros, Victor D. [Russian Research Centre Kurchatov Institute, RU-123182 Moscow (Russian Federation); Leidemann, Winfried; Orlandini, Giuseppina [Dipartimento di Fisica, Universita di Trento, and Istituto Nazionale di Fisica Nucleare, Gruppo Collegato di Trento, I-38050 Povo (Italy); Tomusiak, Edward L. [Department of Physics and Astronomy, University of Victoria, Victoria, V8P 1A1 British Columbia (Canada)

2010-03-15

73

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

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

74

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

NASA Technical Reports Server (NTRS)

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

Campbell, Jonathan W. (Inventor)

2004-01-01

75

An investigation of the normal momentum transfer for gases on tungsten  

NASA Technical Reports Server (NTRS)

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.

Moskal, E. J.

1971-01-01

76

Momentum Transfer to a Free Floating Double Slit: Realization of a Thought Experiment from the Einstein-Bohr Debates  

NASA Astrophysics Data System (ADS)

We simultaneously measured the momentum transferred to a free-floating molecular double slit and the momentum change of the atom scattering from it. Our experimental results are compared to quantum mechanical and semiclassical models. The results reveal that a classical description of the slits, which was used by Einstein in his debate with Bohr, provides a surprisingly good description of the experimental results, even for a microscopic system, if momentum transfer is not ascribed to a specific pathway but shared coherently and simultaneously between both.

Schmidt, L. Ph. H.; Lower, J.; Jahnke, T.; Schößler, S.; Schöffler, M. S.; Menssen, A.; Lévêque, C.; Sisourat, N.; Taïeb, R.; Schmidt-Böcking, H.; Dörner, R.

2013-09-01

77

Linear momentum transfer effects in molecular dissociation produced by electron impact.  

NASA Technical Reports Server (NTRS)

In this study of molecular dissociation produced by electron impact, diatomic systems and polyatomic molecules are considered, and attention is given to the effects of thermal motion and of momentum transfer in the collision process. A procedure is described which makes it possible to 'construct' both the laboratory angular distribution and velocity distribution of the atomic fragments (or, alternatively, the time-of-flight distribution). The calculation assumes that s-wave electron scattering predominates, i.e., that excitation occurs near threshold. The computational procedure may also be reversed to allow construction of possible molecular models to fit given experimental angular and velocity distribution data.

Misakian, M.; Pearl, J. C.; Mumma, M. J.

1972-01-01

78

Four-momentum transfer between fireballs in proton-nucleus interactions at 400 GeV  

SciTech Connect

In 400-GeV proton-nucleus interactions, the fireball candidates are defined by employing three methods (Duller-Walker plot, target plot, and Berger's criterion) simultaneously on each individual event. The lower limit of four-momentum transfer (q/sub l/) between the fireballs is studied. The value of q/sub l/ is found to increase with secondary particle multiplicity. The q/sub l/ distribution favors the exchange of heavy mesons such as the f meson between the fireballs.

Shivpuri, R.K.; Rajaram, B.M.

1987-12-01

79

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

SciTech Connect

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.

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

80

Hydrodynamical interpretation of angular momentum and energy transfer in atomic processes  

NASA Astrophysics Data System (ADS)

Through the description of several simple atomic-scale systems for illustration, the hydrodynamical interpretation of results of solving the time-dependent Schrödinger equation is used to elucidate the fundamental processes of angular momentum and energy transfer. Connections are made between the hydrodynamical interpretation and conventional views such as interference of superpositions of states. Along with previous theoretical and experimental demonstration of the existence of the hydrodynamical signatures born in atomic-scale interactions and remaining in the asymptotic observables, these illustrations show the complementarity of the hydrodynamical and conventional pictures as well as additional insight provided by the former.

Ovchinnikov, S. Y.; Macek, J. H.; Schultz, D. R.

2014-12-01

81

Relativistic shell model: Momentum-transfer dependence of the effective force in nuclei  

SciTech Connect

We calculate the momentum-transfer dependence of the effective nuclear interaction in a conventional model and in a recently developed relativistic model which emphasizes self-consistent-field effects. These latter effects lead to major modifications in the T = 0 interaction for S = 0 and S = 1 and less dramatic changes for the T = 1 interaction. The calculational methods are similar to those used previously and involve considering only the first iteration of the self-consistent field equations. We review these methods of calculation and present some new results for the (off-shell) nucleon self-energy.

Celenza, L.S.; Pong, W.S.; Shakin, C.M.

1983-04-01

82

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

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

83

On effect of wind surface waves on mass and momentum transfer in a stratified turbulent boundary layer  

NASA Astrophysics Data System (ADS)

The most important characteristics that determine the interaction between atmosphere and ocean are fluxes of momentum, heat and moisture. For their parameterization the dimensionless exchange coefficients (the surface drag coefficient CD and the heat transfer coefficient or the Stanton number CT) are used. Numerous field and laboratory experiments show that CD increases with increasing wind speed. This is due to the fact that the transfer of the momentum wave disturbances, or form drag, increases with increasing wind speed, which is accompanied by broadening the wind wave spectrum. The dependence of heat transfer coefficient CT on the wind speed is not well studieds and the role of the mechanism associated with the wave disturbances in the mass transfer is poorly understood. Observations and laboratory data show that this dependence is weaker than for the CD, and there are differences in the character of the dependence in different data sets. For example, the algorithm COARE 3.0 (see [1] indicates a slight increase in CT with increasing wind speed U10, a similar dependence was obtained in [2] and the laboratory experiment, [3], and in [4] a dependence of CT on the wind speed was not found. The weak dependence of the CT on U10 is confirmed by theoretical models [5], but the details of the dependence (growing or dropping) were sensitive to the choice of model. The purpose of this paper is investigation of the effect of waves on the surface of the water on the exchange of momentum and mass to drive the boundary layer of air and from this point of view it largely follows [5]. The main difference is related to the used model of the marine atmospheric boundary layer, in which the perturbations induced by the waves on the water surface in the atmosphere are calculated. It is a generalization of the model developed for a homogeneous atmosphere in [6] to the case of a stratified marine atmospheric boundary layer. The model was recently verified by comparing with experimental results [7] and direct numerical modeling [8]. Two first-order closing models of turbulence are discussed. In the first model, wave-dependent eddy viscosity and heat conductivity are postulated by decreasing turbulent momentum flux near the wavy water surface due to wave momentum transfer. In the second model, the turbulent transfer coefficients are parameterized only by the constant wind friction velocity. Special experiments were carried out in the wind-wave flume to investigate velocity and temperature distribution in the stratified air boundary layer above the water surface disturbed by paddle generated waves. Experiments showed that in accordance with the second closing model the air flow velocity decreases with the growth of the surface wave amplitude and the temperature profile was wave-independent within experimental errors. Surface wave spectrum is an important element of the model. We investigated sensitivity of the model to spectral models, including spectra suggested by [9-12], which describe waves in wide range of wavelengths from energy-containing scales to centimeters and millimeters. Comparing of the theoretical calculations with the experimental algorithm TOGA-COARE [1] shows, that the best agreement takes place, when the Hwang spectrum [12] corrected at high wind conditions is used.

Troitskaya, Yu.; Ezhova, E.; Sergeev, D.; Kandaurov, A.; Baidakov, G.; Vdovin, M.

2012-04-01

84

Optimal fine pointing control of a large space telescope using an Annular Momentum Control Device  

NASA Technical Reports Server (NTRS)

This paper discusses the application of an Annular Momentum Control Device (AMCD) to fine pointing control of a large space telescope (LST). The AMCD represents a new development in the field of momentum storage devices. A linearized mathematical model is developed for the AMCD/LST system, including the magnetic suspension actuators. Two approaches to control system design are considered. The first approach uses a stochastic linear-quadratic Gaussian controller which utilizes feedback of all states. The second approach considers a more practical control system design in which the axial and radial loops are designed independently.

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

1977-01-01

85

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

Microsoft Academic Search

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

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

1999-01-01

86

Tracing sunspot groups to determine angular momentum transfer on the Sun  

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

87

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

SciTech Connect

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.

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

88

Isolated tau leptons in events with large missing transverse momentum at HERA  

Microsoft Academic Search

A search for events containing isolated tau leptons and large missing transverse momentum, not originating from the tau decay, has been performed with the ZEUS detector at the electron–proton collider HERA, using 130 pb?1 of integrated luminosity. A search was made for isolated tracks coming from hadronic tau decays. Observables based on the internal jet structure were exploited to discriminate between tau

S. Bhadra; C. D. Catterall; S. Fourletov; G. Hartner; S. Magill; M. Soares; J. Standage; J. Repond; R. Yoshida; M. C. K. Mattingly; P. Antonioli; G. Bari; M. Basile; L. Bellagamba; D. Boscherini; A. Bruni; G. Bruni; G. Cara Romeo; L. Cifarelli; F. Cindolo; A. Contin; M. Corradi; S. de Pasquale; P. Giusti; G. Iacobucci; A. Margotti; A. Montanari; R. Nania; F. Palmonari; A. Pesci; G. Sartorelli; A. Zichichi; G. Aghuzumtsyan; D. Bartsch; I. Brock; S. Goers; H. Hartmann; E. Hilger; P. Irrgang; H.-P. Jakob; O. Kind; U. Meyer; E. Paul; J. Rautenberg; R. Renner; A. Stifutkin; J. Tandler; K. C. Voss; M. Wang; A. Weber; D. S. Bailey; N. H. Brook; J. E. Cole; G. P. Heath; T. Namsoo; S. Robins; M. Wing; M. Capua; A. Mastroberardino; M. Schioppa; G. Susinno; J. Y. Kim; Y. K. Kim; J. H. Lee; I. T. Lim; M. Y. Pac; A. Caldwell; M. Helbich; X. Liu; B. Mellado; Y. Ning; S. Paganis; Z. Ren; W. B. Schmidke; F. Sciulli; J. Chwastowski; A. Eskreys; J. Figiel; A. Galas; K. Olkiewicz; P. Stopa; L. Zawiejski; L. Adamczyk; T. Bold; I. Grabowska-Bold; D. Kisielewska; A. M. Kowal; M. Kowal; T. Kowalski; M. Przybycien; L. Suszycki; D. Szuba; J. Szuba; A. Kotanski; W. Slominski; V. Adler; U. Behrens; I. Bloch; K. Borras; V. Chiochia; D. Dannheim; G. Drews; J. Fourletova; U. Fricke; A. Geiser; P. Göttlicher; O. Gutsche; T. Haas; W. Hain; S. Hillert; B. Kahle; U. Kötz; H. Kowalski; G. Kramberger; H. Labes; D. Lelas; H. Lim; B. Löhr; R. Mankel; I.-A. Melzer-Pellmann; C. N. Nguyen; D. Notz; A. E. Nuncio-Quiroz; A. Polini; A. Raval; L. Rurua; U. Schneekloth; U. Stoesslein; G. Wolf; C. Youngman; W. Zeuner; S. Schlenstedt; G. Barbagli; E. Gallo; C. Genta; P. G. Pelfer; A. Bamberger; A. Benen; N. Coppola; M. Bell; P. J. Bussey; A. T. Doyle; J. Ferrando; S. Hanlon; D. H. Saxon; I. O. Skillicorn; I. Gialas; B. Bodmann; T. Carli; U. Holm; K. Klimek; N. Krumnack; E. Lohrmann; M. Milite; H. Salehi; P. Schleper; S. Stonjek; K. Wick; A. Ziegler; C. Collins-Tooth; C. Foudas; R. Goncalo; K. R. Long; A. D. Tapper; P. Cloth; D. Filges; M. Kataoka; K. Nagano; K. Tokushuku; S. Yamada; Y. Yamazaki; A. N. Barakbaev; E. G. Boos; N. S. Pokrovskiy; B. O. Zhautykov; D. Son; K. Piotrzkowski; F. Barreiro; C. Glasman; O. González; L. Labarga; J. del Peso; E. Tassi; J. Terrón; M. Vázquez; M. Zambrana; M. Barbi; F. Corriveau; S. Gliga; J. Lainesse; S. Padhi; D. G. Stairs; R. Walsh; T. Tsurugai; A. Antonov; P. Danilov; B. A. Dolgoshein; D. Gladkov; V. Sosnovtsev; S. Suchkov; R. K. Dementiev; P. F. Ermolov; Yu. A. Golubkov; I. I. Katkov; L. A. Khein; I. A. Korzhavina; V. A. Kuzmin; B. B. Levchenko; O. Yu. Lukina; A. S. Proskuryakov; L. M. Shcheglova; N. N. Vlasov; S. A. Zotkin; S. Grijpink; E. Koffeman; P. Kooijman; E. Maddox; A. Pellegrino; S. Schagen; H. Tiecke; J. J. Velthuis; L. Wiggers; E. de Wolf; N. Brümmer; B. Bylsma; L. S. Durkin; T. Y. Ling; A. M. Cooper-Sarkar; A. Cottrell; R. C. E. Devenish; B. Foster; G. Grzelak; C. Gwenlan; S. Patel; P. B. Straub; R. Walczak; A. Bertolin; R. Brugnera; R. Carlin; F. dal Corso; S. Dusini; A. Garfagnini; S. Limentani; A. Longhin; A. Parenti; M. Posocco; L. Stanco; M. Turcato; E. A. Heaphy; F. Metlica; B. Y. Oh; J. J. Whitmore; Y. Iga; G. D'Agostini; G. Marini; A. Nigro; C. Cormack; J. C. Hart; N. A. McCubbin; C. Heusch; I. H. Park; N. Pavel; H. Abramowicz; A. Gabareen; S. Kananov; A. Kreisel; A. Levy; M. Kuze; T. Fusayasu; S. Kagawa; T. Kohno; T. Tawara; T. Yamashita; R. Hamatsu; T. Hirose; M. Inuzuka; H. Kaji; S. Kitamura; K. Matsuzawa; M. I. Ferrero; V. Monaco; R. Sacchi; A. Solano; M. Arneodo; M. Ruspa; T. Koop; G. M. Levman; J. F. Martin; A. Mirea; J. M. Butterworth; R. Hall-Wilton; T. W. Jones; M. S. Lightwood; M. R. Sutton; C. Targett-Adams; J. Ciborowski; R. Ciesielski; P. Luzniak; R. J. Nowak; J. M. Pawlak; J. Sztuk; T. Tymieniecka; A. Ukleja; J. Ukleja; A. F. Zarnecki; M. Adamus; P. Plucinski; Y. Eisenberg; L. K. Gladilin; D. Hochman; U. Karshon; M. Riveline; D. Kcira; S. Lammers; L. Li; D. D. Reeder; M. Rosin; A. A. Savin; W. H. Smith; A. Deshpande; S. Dhawan; S. Menary

2004-01-01

89

Hydrodynamical study of nuclear-size dependence of particle production at large transverse momentum  

Microsoft Academic Search

Using the one-dimensional hydrodynamical model with an additional assumption of particle emission from the high-temperature hadronic fluid before and during its expansion and cooling, we study the phenomenon of nuclear-size-dependent increase of particle production at large transverse momentum first observed by Cronin et al. It is found that the temperature decrease of the fluid of proton-nucleus system with larger nuclear

Naohiko Masuda

1979-01-01

90

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

PubMed Central

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

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

2013-01-01

91

Single transverse-spin asymmetry in Drell-Yan production at large and moderate transverse momentum  

SciTech Connect

We study the single-transverse-spin asymmetry for the Drell-Yan process. We consider production of the lepton pair at large transverse momentum, q{sub perpendicular}{approx}Q, where Q is the pair's mass. The spin asymmetry is then of higher twist and may be generated by twist-three quark-gluon correlation functions. Expanding the result for q{sub perpendicular}<momentum-dependent QCD factorization involving the so-called Sivers functions. We find that the two mechanisms, quark-gluon correlations on one hand and the Sivers effect on the other, contain the same physics in this region. This ties the two together and imposes an important constraint on phenomenological studies of single-transverse-spin asymmetries.

Ji Xiangdong [Physics Department, University of Maryland, College Park, Maryland 20742 (United States); Qiu Jianwei [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); Vogelsang, Werner [Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); RIKEN BNL Research Center, Building 510A, Brookhaven National Laboratory, Upton, New York 11973 (United States); Yuan Feng [RIKEN BNL Research Center, Building 510A, Brookhaven National Laboratory, Upton, New York 11973 (United States)

2006-05-01

92

Q-value measurements in charge-transfer collisions of highly charged ions with atoms by recoil longitudinal momentum spectroscopy  

Microsoft Academic Search

We report on the first Q-value measurements in charge-transfer collisions using recoil longitudinal momentum spectroscopy. This method is not limited to relatively low beam energies and is easily adaptable to captures involving any number of transferred electrons. A very monoenergetic beam is not necessary. For a 50-keV Ar15+ on Ar collision system, Q values coresponding to single through quintuple electron

R. Ali; V. Frohne; C. L. Cocke; M. Stockli; S. Cheng; M. L. A. Raphaelian

1992-01-01

93

Measurement of momentum transfer due to adhesive forces: on-ground testing of in-space body injection into geodesic motion.  

PubMed

In the frame of many scientific space missions, a massive free-falling object is required to mark a geodesic trajectory, i.e., to follow inside a spacecraft an orbit that is determined only by the planetary gravity field. The achievement of high-purity geodesic trajectories sets tight design constraints on the reference sensor that hosts and controls the reference body. Among these, a mechanism may be required to cage the reference body during the spacecraft launch and to inject it into the geodesic trajectory once on-orbit. The separation of the body from the injection mechanism must be realized against the action of adhesion forces, and in the worst case this is performed dynamically, relying on the body's inertia through a quick retraction of the holding finger(s). Unfortunately, this manoeuvre may not avoid transferring some momentum to the body, which may affect or even jeopardize the subsequent spacecraft control if the residual velocity is too large. The transferred momentum measurement facility (TMMF) was developed to reproduce representative conditions of the in-flight dynamic injection and to measure the transferred momentum to the released test mass. In this paper, we describe the design and development of the TMMF together with the achieved measurement performance. PMID:22225249

Bortoluzzi, D; Benedetti, M; Baglivo, L; De Cecco, M; Vitale, S

2011-12-01

94

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

SciTech Connect

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.

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

95

Removal of angular momentum by large scale magnetic stresses in advective accretion flows around black holes  

NASA Astrophysics Data System (ADS)

In 1982, in a seminal work, Blandford and Payne showed the possibility of energy and angular momentum removal from a Keplerian accretion disk by the magnetic field lines that extend from the disk surface to large distance. Further, they argued that such a mechanism is responsible for the observed jets/outflows from accreting sources, when magnetic stresses convert a centrifugal outflow into a collimated jet. However, observationally outflows/jets are mostly found to be emanating from the disk when it is in a hard state which is necessarily non-Keplerian. Here we attempt to obtain a self-consistent set of advective disk solutions in the presence of large scale magnetic field, which has lots of implication to explain low/hard state of sources. Basically, we plan to investigate the effects of large scale magnetic field, with plasma-beta>1 yet, to the advective accretion flows, however restricted to the simpler 1.5-dimensions.

Mukhopadhyay, Banibrata

96

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

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)$^{2}$.

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

97

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

SciTech Connect

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.

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

1994-12-31

98

Experimental investigation of the triple differential cross section for electron impact ionization of N2 and CO2 molecules at intermediate impact energy and large ion recoil momentum  

NASA Astrophysics Data System (ADS)

The (e,2e) triple differential cross sections (TDCS) are measured for the ionization of nitrogen and carbon dioxide molecules in a coplanar asymmetric geometry for a wide range of ejected electron energies and at an incident energy about 500-700 eV. This kinematics corresponds to a large momentum imparted to the ion, and is meant to enhance the recoil scattering. The experimental binary and recoil angular distributions of the TDCS are characterized both by a shift towards larger angles with respect to the momentum transfer direction and by a large intensity in the recoil region, in particular for the ionization of the 'inner' N2(2?g) molecular orbital. The data are compared with the results of calculations using the first Born approximation-two centre continuum (FBA-TCC) theoretical model for treating differential electron impact ionization. The experimentally observed shifts and recoil intensity enhancement are not predicted by the model calculations, which rather yield a TDCS symmetrically distributed around the momentum transfer direction, and completely fail in describing the recoil distribution. It is hoped that these new results will stimulate the development of more refined theories for correctly modelling single ionization of molecules.

Lahmam-Bennani, A.; Staicu Casagrande, E. M.; Naja, A.

2009-12-01

99

Magic mass ratios of complete energy-momentum transfer in one-dimensional elastic three-body collisions  

NASA Astrophysics Data System (ADS)

We consider the one-dimensional scattering of two identical blocks of mass M that exchange energy and momentum via elastic collisions with an intermediary ball of mass m = ? M . Initially, one block is incident upon the ball with the other block at rest. For ? < 1 , the three objects will make multiple collisions with one another. In our analysis, we construct a Euclidean vector V n whose components are proportional to the velocities of the objects. Energy-momentum conservation then requires a covariant recurrence relation for V n that transforms like a pure rotation in three dimensions. The analytic solutions of the terminal velocities result in a remarkable prediction for values of ?, in cases where the initial energy and momentum of the incident block are completely transferred to the scattered block. We call these values for ? "magic mass ratios."

Ee, June-Haak; Lee, Jungil

2015-02-01

100

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

NASA Technical Reports Server (NTRS)

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

Register, D. F.; Trajmar, S.

1984-01-01

101

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

102

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

PubMed

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

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

2014-10-24

103

Q -value measurements in charge-transfer collisions of highly charged ions with atoms by recoil longitudinal momentum spectroscopy  

SciTech Connect

We report on the first {ital Q}-value measurements in charge-transfer collisions using recoil longitudinal momentum spectroscopy. This method is not limited to relatively low beam energies and is easily adaptable to captures involving any number of transferred electrons. A very monoenergetic beam is not necessary. For a 50-keV Ar{sup 15+} on Ar collision system, {ital Q} values coresponding to single through quintuple electron capture were measured and found to be in good agreement with the predictions of the molecular classical overbarrier model.

Ali, R.; Frohne, V.; Cocke, C.L.; Stockli, M.; Cheng, S.; Raphaelian, M.L.A. (J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506-2604 (United States))

1992-10-26

104

Subsonic Plasma Aerodynamics using Lorentzian Momentum Transfer in Atmospheric Normal Glow Discharge Plasmas  

NASA Astrophysics Data System (ADS)

The recent development of the One Atmosphere Uniform Glow Discharge Plasma (OAUGDP) has made it possible to cover large areas, including the wings and fuselage of aircraft, with a thin layer of plasma at low energy cost. The Lorentzian collisions between the ions and neutral gas in the plasma layer couple the electric field and the neutral gas in this layer. The coupling is strong enough at one atmosphere to accelerate the boundary layer flow. One EHD flow acceleration method is based on paraelectric EHD effects, the electrostatic analog of paramagnetism, in which a plasma is accelerated toward increasing electric field gradients, while dragging the neutral gas with it. By using paraelectric effects to add momentum to the flow, we have recently achieved improved flow attachment and increased stall angles in airfoils for external aerodynamic applications. In a second approach, peristaltic flow acceleration, we have used a polyphase power supply to excite the OAUGDP at progressive voltage phase angles on successive linear electrode strips. This excitation produces a traveling wave analogous to the "moving" lights on a theatre marquee, which accelerates the ions and neutral gas to velocities of aerodynamic interest.

Reece Roth, J.; Sin, Hojung; Mohan Madhan, Raja Chandra

2002-10-01

105

On-demand Overlay Networks for Large Scientific Data Transfers  

SciTech Connect

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.

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

2009-10-12

106

Proton Transfer Reactivity of Large Multiply Charged Ions  

PubMed Central

Charge-charge interactions dramatically influence the dissociation and proton transfer reactivity of large multiply protonated ions. In combination with tandem mass spectrometry, proton transfer reactions have been used to determine the charge state of an ion and to increase the effective mass resolution of electrospray ionization mass spectra. A model for the proton transfer reactivity of multiply protonated ions, in which protons are assigned to specific sites in an ion based on the intrinsic reactivity of the site and the sum of point-charge Coulomb interactions between charges, is discussed. In combination with experimentally measured rates of proton transfer to bases of known gas-phase basicity, information about the intramolecular electrostatic interactions, gas-phase ion conformation and maximum charge state of an ion produced by electrospray ionization can be obtained. PMID:8799309

Williams, Evan R.

2005-01-01

107

Optimal maneuvering and fine pointing control of large space telescope with a new magnetically suspended, single gimballed momentum storage device  

NASA Technical Reports Server (NTRS)

This paper considers the application of an Annular Momentum Control Device (AMCD) to both fine pointing and large-angle maneuvering of a large space telescope (LST). The AMCD, which consists principally of a spinning rim suspended in noncontacting electromagnetic bearings, represents a new development in momentum storage devices. A nonlinear mathematical model of the AMCD/LST system is derived. An optimal stochastic fine-pointing controller is designed via LQG theory and the minimum-energy maneuvering problem is solved via a gradient technique. Number of state variable and control variable constraints, as well as all trigonometric nonlinearities, are considered in the latter part.

Nadkarni, A. A.; Joshi, S. M.

1976-01-01

108

Large Cash Transfers to the Elderly in South Africa  

Microsoft Academic Search

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,

Anne Case; Angus Deaton

1998-01-01

109

Coherent spin-transfer dynamics in diluted magnetic semiconductor quantum wells even after optical excitation with zero net angular momentum  

NASA Astrophysics Data System (ADS)

A quantum kinetic study of correlated spin transfer between optically excited electrons and Mn atoms in a ZnMnSe quantum well is presented. The simulations predict genuine signatures of non-Markovian spin dynamics which are particularly pronounced for special two-color laser excitations with a zero net angular momentum where a Markovian theory predicts an almost zero total electron spin for all times. In contrast, in the quantum kinetic simulations a sizable total electron spin builds up. Subsequently, a coherent oscillatory exchange of spin between the electron and Mn subsystems is observed.

Thurn, C.; Cygorek, M.; Axt, V. M.; Kuhn, T.

2013-10-01

110

Cfd Modeling of Iter Cable-In Superconductors. Part v: Combined Momentum and Heat Transfer in Rib Roughened Pipes  

NASA Astrophysics Data System (ADS)

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.

Zanino, R.; Giors, S.

2008-03-01

111

The effect of eddy distribution on momentum and heat transfer near the wall in turbulent pipe flow  

NASA Technical Reports Server (NTRS)

A study was conducted to determine the effect of eddy distribution on momentum and heat transfer near the wall in turbulent pipe flow. The buffer zone was of particular interest in that it is perhaps the most complicated and least understood region in the turbulent flow field. Six eddy diffusivity relationships are directly compared on their ability to predict mean velocity and temperature distributions in turbulent air flow through a cylindrical, smooth-walled pipe with uniform heat transfer. Turbulent flow theory and the development of the eddy diffusivity relationships are briefly reviewed. Velocity and temperature distributions derived from the eddy diffusivity relationships are compared to experimental data for fully-developed pipe flow in turbulent air at a Prandtl number of 0.73 and Reynolds numbers ranging from 8100 to 25 000.

Zurawski, Robert L.; Grisnik, Stanley P.; Hardy, Terry L.; Ghorashi, Bahman

1987-01-01

112

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

NASA Technical Reports Server (NTRS)

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.

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

1971-01-01

113

Momentum imbalance of D mesons in ultrarelativistic heavy-ion collisions at the CERN Large Hadron Collider  

NASA Astrophysics Data System (ADS)

As a new observable for heavy flavor correlations the momentum imbalance AD of D mesons is proposed. It is defined analogously to the jet momentum imbalance AJ of fully reconstructed jets. However, because D mesons are flavor-tagged particles, no jet reconstruction is necessary. AD quantifies the influence of the medium created in heavy-ion collisions on correlated charm pairs. We present results with the partonic transport model Boltzmann approach to multiparton scatterings, which describes well the nuclear modification factor and elliptic flow of all heavy flavor particles at BNL Relativistic Heavy Ion Collider and Large Hadron Collider (LHC). The AD distribution in heavy-ion collisions at LHC is shifted to larger values of AD compared to proton-proton collisions. We argue that this shift is attributable to medium effects and can be explained partially by a path-length imbalance of charm pairs and partially by momentum fluctuations in the initial charm-pair distribution.

Uphoff, Jan; Senzel, Florian; Xu, Zhe; Greiner, Carsten

2014-06-01

114

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

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

115

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

NASA Astrophysics Data System (ADS)

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

Slonczewski, John

2013-03-01

116

Becoming angular momentum density flow through nonlinear mass transfer into a gravitating spheroidal body  

NASA Astrophysics Data System (ADS)

A statistical theory for a cosmological body forming based on the spheroidal body model has been proposed in the works [1]-[4]. This work studies a slowly evolving process of gravitational condensation of a spheroidal body from an infinitely distributed gas-dust substance in space. The equation for an initial evolution of mass density function of a gas-dust cloud is considered here. It is found this equation coincides completely with the analogous equation for a slowly gravitational compressed spheroidal body [5]. A conductive flow in dissipative systems was investigated by I. Prigogine in his works (see, for example, [6], [7]). As it has been found in [2], [5], there exists a conductive antidiffusion flow in a slowly compressible gravitating spheroidal body. Applying the equation of continuity to this conductive flow density we obtain a linear antidiffusion equation [5]. However, if an intensity of conductive flow density increases sharply then the linear antidiffusion equation becomes a nonlinear one. Really, it was pointed to [6] analogous linear equations of diffusion or thermal conductivity transform in nonlinear equations respectively. In this case, the equation of continuity describes a nonlinear mass flow being a source of instabilities into a gravitating spheroidal body because the gravitational compression factor G is a function of not only time but a mass density. Using integral substitution we can reduce a nonlinear antidiffusion equation to the linear antidiffusion equation relative to a new function. If the factor G can be considered as a specific angular momentum then the new function is an angular momentum density. Thus, a nonlinear momentum density flow induces a flow of angular momentum density because streamlines of moving continuous substance come close into a gravitating spheroidal body. Really, the streamline approach leads to more tight interactions of "liquid particles" that implies a superposition of their specific angular momentums. This superposition forms an antidiffusion flow of an angular momentum density into a gravitating spheroidal body. References: [1] Krot, A.M. The statistical model of gravitational interaction of particles. Achievement in Modern Radioelectronics (spec.issue"Cosmic Radiophysics", Moscow), 1996, no.8, pp. 66-81 (in Russian). [2] Krot, A.M. Statistical description of gravitational field: a new approach. Proc. SPIE's 14th Annual Intern.Symp. "AeroSense", Orlando, Florida, USA, 2000, vol.4038, pp.1318-1329. [3] Krot, A.M. The statistical model of rotating and gravitating spheroidal body with the point of view of general relativity. Proc.35th COSPAR Scientific Assembly, Paris, France, 2004, Abstract A-00162. [4] Krot, A. The statistical approach to exploring formation of Solar system. Proc.EGU General Assembly, Vienna, Austria, 2006, Geophys.Res.Abstracts, vol.8, A-00216; SRef-ID: 1607-7962/gra/. [5] Krot, A.M. A statistical approach to investigate the formation of the solar system. Chaos, Solitons and Fractals, 2008, doi:10.1016/j.chaos.2008.06.014. [6] Glansdorff, P. and Prigogine, I. Thermodynamic Theory of Structure, Stability and Fluctuations. London, 1971. [7] Nicolis, G. and Prigogine, I. Self-organization in Nonequilibrium Systems:From Dissipative Structures to Order through Fluctuation. John Willey and Sons, New York etc., 1977.

Krot, A. M.

2009-04-01

117

Continuum-particle hybrid coupling for mass, momentum, and energy transfers in unsteady fluid flow.  

PubMed

The aim of hybrid methods in simulations is to communicate regions with disparate time and length scales. Here, a fluid described at the atomistic level within an inner region P is coupled to an outer region C described by continuum fluid dynamics. The matching of both descriptions of matter is made across an overlapping region and, in general, consists of a two-way coupling scheme (C-->P and P-->C) that conveys mass, momentum, and energy fluxes. The contribution of the hybrid scheme hereby presented is twofold. First, it treats unsteady flows and, more importantly, it handles energy exchange between both C and P regions. The implementation of the C-->P coupling is tested here using steady and unsteady flows with different rates of mass, momentum and energy exchange. In particular, relaxing flows described by linear hydrodynamics (transversal and longitudinal waves) are most enlightening as they comprise the whole set of hydrodynamic modes. Applying the hybrid coupling scheme after the onset of an initial perturbation, the cell-averaged Fourier components of the flow variables in the P region (velocity, density, internal energy, temperature, and pressure) evolve in excellent agreement with the hydrodynamic trends. It is also shown that the scheme preserves the correct rate of entropy production. We discuss some general requirements on the coarse-grained length and time scales arising from both the characteristic microscopic and hydrodynamic scales. PMID:12786526

Delgado-Buscalioni, R; Coveney, P V

2003-04-01

118

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

Microsoft Academic Search

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

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

2011-01-01

119

HEAT, MOMENTUM, AND MASS TRANSFER MEASUREMENTS IN INDIRECT AGITATED SLUDGE DRYER  

Microsoft Academic Search

Whereas indirect agitated drying has been extensively studied for granular materials, little is known in the case of pasty products. We describe an experimental set up specially designed for the investigation of drying kinetics, of heat transfer coefficient evolution, and of the mechanical torque necessary for stirring. This device was applied to municipal sewage sludge. Preliminary experiments were performed to

J. H. Ferrasse; P. Arlabosse; D. Lecomte

2002-01-01

120

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

ERIC Educational Resources Information Center

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

McCrink, Koleen; Wynn, Karen

2009-01-01

121

Momentum transfer driven textural changes of CeO2 thin films  

NASA Astrophysics Data System (ADS)

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.

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

2014-09-01

122

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

SciTech Connect

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

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

2014-09-15

123

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

Microsoft Academic Search

A box model to simulate mass transfer inside deep street canyons and with atmospheric flow above is introduced and discussed.\\u000a Two ideal deep street canyons with aspect ratios of 3 and 5 (the aspect ratio being the ratio between building height and\\u000a street width H\\/W) are considered. This range of aspect ratios, found in many densely populated historical centres in

F. Murena; A. Di Benedetto; M. D’Onofrio; G. Vitiello

2011-01-01

124

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

125

A Examination of Two-Nucleon Correlations in CARBON-12 via (electron, Electron' Proton) and (electron, Electron' Deuteron) at X = 2 and Momentum Transfer = 913 Mev/c.  

NASA Astrophysics Data System (ADS)

This thesis describes the measurement of ^{12}C(e,e^' p) and ^{12}C(e,e ^'d) at the kinematics for quasielastic knockout of a deuteron with a momentum transfer of 913 MeV/c and an energy transfer of 213 MeV. We measured the coincidence cross section as a function of the missing energy over the range E_{m } = 0-210. The experiment was performed in February 1989 in the South Hall at the Bates Linear Accelerator Center. We used the Bigbite and OHIPS spectrometers to detect the scattered electrons and hadrons respectively. The beam energy was 781 MeV. The data was a challenge to analyze because of the low statistics, some faulty electronics, and the poor performance of the electron spectrometer. The problems which affected the data have been understood and corrected. The data has also been corrected for radiative effects. In the ^{12}C(e,e ^'p) cross section we can identify a narrow peak at 18 MeV associated with proton knockout from the P-shell and a region from 27-60 MeV which we attribute to knockout from the S-shell and to multinucleon reactions. The cross section above 60 MeV is consistent zero except for a small bump at E_{m } ~ 110 MeV. This tiny peak occurs at E_{m} ~ omega/2 which corresponds to the break-up of a two-nucleon pair. The cross section at this point is on the same order as the total measured cross section for deuteron knockout. We compared the P-shell and S-shell ^ {12}C(e,e^'p) cross section to a factorized DWIA calculation. We used the program PEEPSO to generate the distorted momentum distributions and the program MONTEEP to form the theoretical counts spectra. The calculated cross section greatly overestimated the data. Comparisons between theory and data for a range of experiments suggests that the theoretical momentum distributions for large negative missing momentum are in error. In the ^{12}C(e,e ^'d) cross section we can identify a narrow peak at 26 MeV which corresponds to deuteron knockout where the residual ^{10} B nucleus remains in the ground state or a low excited state. A second broad peak centered at 65 MeV is associated with deuteron knockout where one of the nucleons was in the S-shell and the other was in either the S- or the P -shell. We developed a simple kinematical model to describe the ^{12}C(e,e ^'d) cross section. The missing energy distribution and center-of-mass momentum distribution for the n-p was generated by convoluting the single particle distributions. We examined several models for the n-p relative momentum distribution. The results have a similar form to the data and indicate that the knocked-on n-p pair interact via a short range N-N potential. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.).

Penn, Steven Douglas

126

Large-Eddy Simulation of Heat Transfer from a Single Cube Mounted on a Very Rough Wall  

NASA Astrophysics Data System (ADS)

The local thermal effects in the wake of a single cube with a strong heated rear face, representing a large building in an urban area, are studied using large-eddy simulations (LES) for various degrees of heating, which are characterized by the local Richardson number, Ri. New wall models are implemented for momentum and temperature and comparison of the flow and thermal fields with the wind-tunnel data of Richards et al. (J Wind Eng Ind Aerodyn 94, 621-636, 2006) shows fair agreement. Buoyancy effects are quite evident at low Ri and a significant increase in the turbulence levels is observed for such flows. Apart from the comparisons with experiments, further analysis included the estimation of the thermal boundary-layer thickness and heat transfer coefficient for all Ri. For sufficiently strong heating, the heat transfer coefficient at the leeward face is found to be higher than the roof surface. This suggests that, beyond a certain Ri value, buoyancy forces from the former surface dominate the strong streamwise convection of the latter. Quadrant analysis along the shear layer behind the cube showed that the strength of sweeps that contribute to momentum flux is considerably enhanced by heating. The contribution of different quadrants to the heat flux is found to be very different to that of the momentum flux for lower Ri.

Boppana, V. B. L.; Xie, Zheng-Tong; Castro, Ian P.

2013-06-01

127

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

NASA Astrophysics Data System (ADS)

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.

Pereira, Ricardo; Ragni, Daniele; Kotsonis, Marios

2014-09-01

128

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

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...

Hutchison, James P

1961-01-01

129

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

NASA Astrophysics Data System (ADS)

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

Granada, Anahí; Haemmerlé, Lionel

2014-10-01

130

Dynamic form factor of liquid4He at intermediate momentum transfer  

NASA Astrophysics Data System (ADS)

Measurements of the inelastic neutron scattering from liquid4He at T=1.2 K in the range of wavevector transfer 3? Q?12 Å-1 have been performed to verify the oscillations in the peak position and the width of the scattering function with Q observed by Cowley and Woods and by Martel et al. We confirm these oscillations and extend the measurements to show that the oscillations in the width continue up to Q?12 Å-1 while oscillations in the peak position, which have a much smaller amplitude, could be observed with confidence up to Q?8 Å-1 only. We also present a straightforward RPA calculation of the dynamic form factor S(Q, ?), beginning from the pair interatomic potential, to see how well the observed S(Q, ?) can be described and to investigate the origin of the oscillations. The observed S(Q, ?) is quite well reproduced and the oscillations in the width and peak position of S(Q, ?) are seen to originate from oscillations in the interaction in the RPA which we have approximated as the4He-4He scattering amplitude calculated from v(r). While the present calculation is quite different from the model proposed previously by Martel et al., the physical origin of the oscillations in S( Q, ?) is the same, namely oscillations in the4He-4He atom scattering amplitude.

Stirling, W. G.; Talbot, E. F.; Tanatar, B.; Glyde, H. R.

1988-10-01

131

Dynamic form factor of liquid /sup 4/He at intermediate momentum transfer  

SciTech Connect

Measurements of the inelastic neutron scattering from liquid /sup 4/He at T = 1.2 K in the range of wavevector transfer 3 less than or equal to Q less than or equal to 12 /angstrom/ /sup /minus/1/ have been performed to verify the oscillations in the peak position and the width of the scattering function with Q observed by Cowley and Woods and by Martel et al. The authors confirm these oscillations and extend the measurements to show that the oscillations in the width continue up to Q approx. 12 /angstrom/ /sup /minus/1/ while oscillations in the peak position, which have a much smaller amplitude, could be observed with confidence up to Q approx. 8 /angstrom//sup /minus/1/ only. They also present a straightforward RPA calculation of the dynamic form factor S(Q, ..omega..), beginning from the pair interatomic potential, to see how well the observed S(Q, ..omega..) can be described and to investigate the origin of the oscillations. The observed S(Q, ..omega..) is quite well reproduced and the oscillations in the width and peak position of S(Q, ..omega..) are seen to originate from oscillations in the interaction in the RPA which they have approximated as the /sup 4/He-/sup 4/He scattering amplitude calculated from v(r). While the present calculation is quite different from the model proposed previously by Martel et al., the physical origin of the oscillations in S(Q, ..omega..) is the same, namely oscillations in the /sup 4/He-/sup 4/He atom scattering amplitude.

Stirling, W.G.; Talbot, E.F. Tanatar, B.; Glyde, H.R.

1988-10-01

132

High Momentum Transfer Shallow Core-to-valence Spectroscopy in the Actinides  

NASA Astrophysics Data System (ADS)

We calculate the dynamic structure factor S(q,?) within a renormalized atomic multiplet approach, to describe the 5d->5f non-resonant inelastic x-ray scattering (NIXS) in actinide compounds ThO2 (5f^0) and UO2 (5f^2). For small q, the spectra select the dipole-allowed transitions which are degenerate with continuum states, hindering their use in ground electronic structure determination. However dipole-forbidden multiplets reached with large q are strongly bound to the core-hole, enabling the use of a renormalized atom approach to extract the ground state electronic structure. This crossover from unbound to bound states, reachable by low-q and high-q experiments respectively, is a result of the large multiplet spread of the 5d^95f^N+1 multiplets exceeding the attractive core-hole potential. We discuss the details of the calculations and emphasize the importance of high-q experiments in studies of the ground state electronic structure of actinides.

Gupta, Subhra Sen; Bradley, J. A.; Haverkort, M. W.; Seidler, G. T.; Sawatzky, G. A.

2010-03-01

133

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

SciTech Connect

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

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

2014-04-01

134

Measurement of the deuteron elastic structure functions at large momentum transfers  

SciTech Connect

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.

Kathy McCormick

1999-08-01

135

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

SciTech Connect

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.

Dey, Biplab [University of Zurich

2014-07-01

136

Sheep: The First Large Animal Model in Nuclear Transfer Research  

PubMed Central

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

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

2013-01-01

137

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

NASA Technical Reports Server (NTRS)

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.

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

138

Measurements of momentum transfer coefficients for H2, N2, CO and CO2 incident upon spacecraft surfaces  

NASA Technical Reports Server (NTRS)

Measurements of momentum transfer coefficients were made for gas-surface interactions between the Space Shuttle reaction control jet plume gases and the solar panel array materials to be used on the International Space Station. Actual conditions were simulated using a supersonic nozzle source to produce beams of the gases with approximately the same average velocities as the gases have in the Shuttle plumes. Samples of the actual solar panel materials were mounted on a torsion balance that was used to measure the force exerted on the surfaces by the molecular beams. Measurements were made with H2, N2, CO, and CO2 incident upon the solar array material, Kapton, SiO2-coated Kapton, and Z93-coated Al. The measurements showed that molecules scatter from the surfaces more specularly as the angle of incidence increases and that 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.

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

1997-01-01

139

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

NASA Technical Reports Server (NTRS)

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

Cook, Steven R.; Hoffbauer, Mark A.

1997-01-01

140

Large Frame-Transfer Detectors for the MAIA Imager  

E-print Network

MAIA, the Mercator Advanced Imager for Asteroseismology, is a new fast-cadence 3-channel photometric instrument. It is installed on the 1.2-m Mercator telescope at the Roque de Los Muchachos Observatory in La Palma, Spain. MAIA comprises 3 cameras that simultaneously observe the same 9.4 x 14.1 arcmin field in 3 different colour bands (u, g and r). Each camera is based on a very large frame-transfer detector (CCD42-C0) of 2kx6k pixels, specially designed for rapid time-series photometry. These CCDs were originally developed by e2v for ESA's cancelled Eddington space mission and are now on permanent loan to the Institute of Astronomy of the KU Leuven, Belgium. The acquisition system of MAIA uses a single ARC GEN-III controller, custom programmed to allow differing exposure times for each of the three CCDs. Predefined sequences synchronize each read-out with the shortest integration time. Detectors that are not read-out at the end of an exposure continue integrating and can be read-out in one of the subsequent ...

Padilla, Jesús Pérez; Raskin, Gert; Prins, Saskia; Merges, Florian; Pessemier, Wim; Bloemen, Steven

2013-01-01

141

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

NASA Astrophysics Data System (ADS)

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

Kim, Ji Hoon

2015-01-01

142

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

Microsoft Academic Search

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

K. L. Davidson

1974-01-01

143

On maneuvering large flexible spacecraft using an annular momentum control device  

NASA Technical Reports Server (NTRS)

A scheme for the control and maneuvering of a large flexible spacecraft by means of two flexible AMCD's using noncontacting magnetic suspension is presented. The system consists of a flexible vehicle, two flexible rings and a magnetic suspension and driving assembly. The necessary skewing of the rings for maneuvering of the vehicle is accomplished by moving the pairs of magnets along tracks distributed around the circumference of the vehicle. The equations of motion for each subsystem are derived by the Lagrangian approach. Attitude motions are described in terms of quasi-coordinates. For small vehicle angular rates and rings attitude motions, an ordering scheme can be used to separate the equations of motion according to the magnitude of the terms. The ordered equations of motion lead to a linear time-variant optimal control problem for the maneuvering of the spacecraft.

Oz, H.; Meirovitch, L.; Montgomery, R. C.

1980-01-01

144

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

E-print Network

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

Taylor, Frank E.

145

Heat transfer in large-scale heavy-gas dispersion.  

PubMed

Heavy-gas dispersion of practical interest is usually cold gas dispersion with the enthalpy deficit as the main cause of the density effect. New analysis of existing field experiment data suggests that heat transfer from the ground sometimes reduces this thermally induced density effect considerably. The limited heat capacity of the ground implies that heat transfer to a gas plume must disappear eventually, and our interpretation of Desert Tortoise measurements indicates that the surface heat flux decreased by 38% during a 3-min long release period. PMID:10334831

Nielsen, M; Ott, S

1999-05-31

146

Deposition of thin silicon layers on transferred large area graphene  

SciTech Connect

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

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

2013-12-23

147

Measurement of angular correlations of jets at ?{s}=1.96 TeV and determination of the strong coupling at high momentum transfers  

NASA Astrophysics Data System (ADS)

We present a measurement of the average value of a new observable at hadron colliders that is sensitive to QCD dynamics and to the strong coupling constant, while being only weakly sensitive to parton distribution functions. The observable measures the angular correlations of jets and is defined as the number of neighboring jets above a given transverse momentum threshold which accompany a given jet within a given distance ?R in the plane of rapidity and azimuthal angle. The ensemble average over all jets in an inclusive jet sample is measured and the results are presented as a function of transverse momentum of the inclusive jets, in different regions of ?R and for different transverse momentum requirements for the neighboring jets. The measurement is based on a data set corresponding to an integrated luminosity of 0.7 fb-1 collected with the D0 detector at the Fermilab Tevatron Collider in ppbar collisions at ?{s}=1.96 TeV. The results are well described by a perturbative QCD calculation in next-to-leading order in the strong coupling constant, corrected for non-perturbative effects. From these results, we extract the strong coupling and test the QCD predictions for its running over a range of momentum transfers of 50-400 GeV.

Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Bose, T.; Brandt, A.; Brandt, O.; Brock, R.; Bross, A.; Brown, D.; Brown, J.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Chevalier-Théry, S.; Cho, D. K.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Croc, A.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duggan, D.; Duperrin, A.; Dutt, S.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Facini, G.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garcia-Bellido, A.; García-González, J. A.; García-Guerra, G. A.; Gavrilov, V.; Gay, P.; Geng, W.; Gerbaudo, D.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Goussiou, A.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Hagopian, S.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jeong, M. S.; Jesik, R.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kaadze, K.; Kajfasz, E.; Karmanov, D.; Kasper, P. A.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kulikov, S.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Maravin, Y.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Naimuddin, M.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nunnemann, T.; Orduna, J.; Osman, N.; Osta, J.; Padilla, M.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M.-A.; Podesta-Lerma, P. L. M.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Rangel, M. S.; Ranjan, K.; Ratoff, P. N.; Razumov, I.; Renkel, P.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Salcido, P.; Sánchez-Hernández, A.; Sanders, M. P.; Santos, A. S.; Savage, G.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schlobohm, S.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Shivpuri, R. K.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Smith, K. J.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Suter, L.; Svoisky, P.; Takahashi, M.; Titov, M.; Tokmenin, V. V.; Tsai, Y.-T.; Tschann-Grimm, K.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vasilyev, I. A.; Verdier, P.

2012-11-01

148

Measurement of angular correlations of jets at s=1.96 TeV and determination of the strong coupling at high momentum transfers  

NASA Astrophysics Data System (ADS)

We present a measurement of the average value of a new observable at hadron colliders that is sensitive to QCD dynamics and to the strong coupling constant, while being only weakly sensitive to parton distribution functions. The observable measures the angular correlations of jets and is defined as the number of neighboring jets above a given transverse momentum threshold which accompany a given jet within a given distance ?R in the plane of rapidity and azimuthal angle. The ensemble average over all jets in an inclusive jet sample is measured and the results are presented as a function of transverse momentum of the inclusive jets, in different regions of ?R and for different transverse momentum requirements for the neighboring jets. The measurement is based on a data set corresponding to an integrated luminosity of 0.7 fb-1 collected with the D0 detector at the Fermilab Tevatron Collider in pp¯ collisions at s=1.96 TeV. The results are well described by a perturbative QCD calculation in next-to-leading order in the strong coupling constant, corrected for non-perturbative effects. From these results, we extract the strong coupling and test the QCD predictions for its running over a range of momentum transfers of 50-400 GeV.

D0 Collaboration; Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Alverson, G.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Bose, T.; Brandt, A.; Brandt, O.; Brock, R.; Bross, A.; Brown, D.; Brown, J.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chakraborty, D.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Chevalier-Théry, S.; Cho, D. K.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Croc, A.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duggan, D.; Duperrin, A.; Dutt, S.; Dyshkant, A.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, A.; Evdokimov, V. N.; Facini, G.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garcia-Bellido, A.; García-González, J. A.; García-Guerra, G. A.; Gavrilov, V.; Gay, P.; Geng, W.; Gerbaudo, D.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Golovanov, G.; Goussiou, A.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Hagopian, S.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jeong, M. S.; Jesik, R.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kaadze, K.; Kajfasz, E.; Karmanov, D.; Kasper, P. A.; Katsanos, I.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kulikov, S.; Kumar, A.; Kupco, A.; Kur?a, T.; Kuzmin, V. A.; Lammers, S.; Landsberg, G.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Lubatti, H. J.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Maravin, Y.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Naimuddin, M.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nunnemann, T.; Orduna, J.; Osman, N.; Osta, J.; Padilla, M.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M.-A.; Podesta-Lerma, P. L. M.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Rangel, M. S.; Ranjan, K.; Ratoff, P. N.; Razumov, I.; Renkel, P.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Salcido, P.; Sánchez-Hernández, A.; Sanders, M. P.; Santos, A. S.; Savage, G.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schlobohm, S.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Shivpuri, R. K.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Smith, K. J.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Suter, L.; Svoisky, P.; Takahashi, M.; Titov, M.; Tokmenin, V. V.; Tsai, Y.-T.; Tschann-Grimm, K.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vasilyev, I. A.

2012-11-01

149

Large oncosomes mediate intercellular transfer of functional microRNA  

PubMed Central

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

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

150

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

PubMed

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

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

2014-01-01

151

The effects of collision energy, vibrational mode, and vibrational angular momentum on energy transfer and dissociation in NO2  

E-print Network

The effects of collision energy, vibrational mode, and vibrational angular momentum on energy effects of NO2 + vibrational excitation that extend over the entire collision energy range, implying dynamics trajectories for NO2 + +Kr reproduce both the collision energy and vibrational state effects

Anderson, Scott L.

152

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

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 ...

Taylor, Frank E.

153

Modeling on the Momentum and Heat\\/Mass Transfer Characteristics of an Argon Plasma Jet Issuing into Air Surroundings and Interacting with a Counter-Injected Argon Jet  

Microsoft Academic Search

Modeling study is performed to reveal the momentum and heat\\/mass transfer characteristics of a turbulent or laminar plasma\\u000a reactor consisting of an argon plasma jet issuing into ambient air and interacting with a co-axially counter-injected argon\\u000a jet. The combined-diffusion-coefficient method and the turbulence-enhanced combined-diffusion-coefficient method are employed\\u000a to treat the diffusion of argon in the argon–air mixture for the laminar

Hai-Xing WangXi; Xi Chen; He-Ping Li

2011-01-01

154

MESSENGER Observations of Large Flux Transfer Events at Mercury  

NASA Technical Reports Server (NTRS)

Six flux transfer events (FTEs) were encountered during MESSENGER's first two flybys of Mercury (M1 and M2). For M1 the interplanetary magnetic field (IMF) was predominantly northward and four FTEs with durations of 1 to 6 s were observed in the magnetosheath following southward IMF turnings. The IMF was steadily southward during M2, and an FTE 4 s in duration was observed just inside the dawn magnetopause followed approx. 32 s later by a 7 s FTE in the magnetosheath. Flux rope models were fit to the magnetic field data to determine FTE dimensions and flux content. The largest FTE observed by MESSENGER had a diameter of approx. 1 R(sub M) (where R(sub M) is Mercury s radius), and its open magnetic field increased the fraction of the surface exposed to the solar wind by 10 - 20 percent and contributed up to approx. 30 kV to the cross-magnetospheric electric potential.

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

2010-01-01

155

MESSENGER Observations of Large Flux Transfer Events at Mercury  

NASA Technical Reports Server (NTRS)

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

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

2010-01-01

156

Measured Ethernet performance for multiple large file transfers  

Microsoft Academic Search

This study analyzes traffic on a 10-Mb\\/s Ethernet local area network that connects PCs, minicomputers (running UNIX), engineering workstations, and other equipment in an electronics manufacturing environment. The network is artificially loaded by having up to 32 PCs exchanging large files with seventeen minicomputers. Traffic levels of over 50% of network bandwidth are generated. Several parameters including network utilization, collision

S. Francis; V. S. Frost; D. L. Soldan

1989-01-01

157

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...

158

Numerical computation of arbitrary order transfer maps and reconstructive correction of aberrations in the large acceptance spectrometer MAGNEX  

NASA Astrophysics Data System (ADS)

The large angular (˜50 msr) and momentum (˜20%) acceptance spectrometer MAGNEX is under construction at the South National Laboratories INFN. In the spectrometer, positions of ions in two planes near the focal plane and their vertical positions near the target are measured. The energy resolution of about 1000 is achieved due to the use of the reconstruction of trajectories and reconstructive correction of aberrations. Main features of the spectrometer ion optics are considered. A numerical method of calculation of an arbitrary order transfer map is proposed. In this method, a transfer map is calculated using, as input, initial and final coordinates of a set of rays in an ion-optical system. The rays start at the nods of a regular multi-dimensional mesh in the particle phase space. Rays of the set are chosen automatically according to the order and dimension of the map to be calculated. Final coordinates of the rays are calculated with a regular numerical integration. The proposed is, in fact, a general (ray tracing based) method of calculation of a transfer map, of any order and dimension, for an arbitrary ion-optical system. The method has been used for numerical simulations of the reconstructive correction of aberrations in the MAGNEX spectrometer. Simulation results are considered. A C++ class library has been developed to realize the proposed transfer map calculation method. Elementary operations with vectors and maps, both being C++ objects, are realized as C++ operator functions. The map order is defined by a user at the moment of initialization of the corresponding map object. Its maximum value is limited only by an available computer memory. Computational aspects of the method are discussed in brief.

Shchepunov, V. A.; Cunsolo, A.; Cappuzzello, F.; Foti, A.; Lazzaro, A.; Melita, A. L.; Nociforo, C.; Winfield, J. S.

2003-05-01

159

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

NASA Technical Reports Server (NTRS)

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%.

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

2005-01-01

160

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

Microsoft Academic Search

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

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

2012-01-01

161

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

Microsoft Academic Search

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

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

2007-01-01

162

A numerical study of momentum and forced convection heat transfer around two tandem circular cylinders at low Reynolds numbers. Part II: Forced convection heat transfer  

Microsoft Academic Search

This work presents a computational study of the forced convection heat transfer around two circular cylinders in tandem. Axisymmetric, steady, laminar flow around the cylinders was assumed. The temperature inside the cylinders is considered spatially uniform but not constant in time. Numerical solutions have been obtained in bipolar cylindrical coordinates. The finite difference method was used to discretize the equations

Gheorghe Juncu

2007-01-01

163

Direct determination of resonance phase shifts of soft x-ray diffraction in thin films by momentum-transfer-sensitive three-wave interference  

SciTech Connect

A method for direct determination of resonance phase shifts in a (001) CdTe/InSb thin-film system is developed using soft x-ray three-wave resonance diffraction. At the (002) Bragg peaks of CdTe and InSb, two inversion-symmetry related three-wave diffractions are systematically identified according to crystal symmetry and the resonance phase shifts versus photon energies are measured without turning the thin film upside down. The momentum-transfer selectivity at (002) reflections facilitates the quantitative determination of the phase shifts near the Cd L{sub 3}, Te L{sub 3}, and Sb L{sub 2} edges.

Wu, H.-H.; Lee, Y.-R.; Chang, Y.-Y.; Chu, C.-H.; Tsai, Y.-W.; Liu, Y.-J.; Chang, S.-L. [Department of Physics, National Tsing Hua University, Hsinchu, Taiwan 300 (China); Hsieh, C.-H.; Chou, L.-J. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan 300 (China)

2008-09-01

164

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

PubMed Central

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

Muhammad, Wazir; Lee, Sang Hoon

2013-01-01

165

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

NASA Technical Reports Server (NTRS)

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.

Yang, Eui-Hyeok; Shcheglov, Kirill

2002-01-01

166

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

NASA Astrophysics Data System (ADS)

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

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

2012-05-01

167

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

E-print Network

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

Hammes-Schiffer, Sharon

168

Multiple Phenotypic Changes Associated with Large-Scale Horizontal Gene Transfer  

PubMed Central

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

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

2014-01-01

169

Search for new phenomena in final states with large jet multiplicities and missing transverse momentum at TeV proton-proton collisions using the ATLAS experiment  

NASA Astrophysics Data System (ADS)

A search is presented for new particles decaying to large numbers (7 or more) of jets, with missing transverse momentum and no isolated electrons or muons. This analysis uses 20.3 fb-1 of pp collision data at TeV collected by the ATLAS experiment at the Large Hadron Collider. The sensitivity of the search is enhanced by considering the number of b-tagged jets and the scalar sum of masses of large-radius jets in an event. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of various simplified supersymmetry-inspired models where gluinos are pair produced, as well as an mSUGRA/CMSSM model. [Figure not available: see fulltext.

Aad, G.; Abajyan, T.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Adomeit, S.; Adye, T.; Aefsky, S.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmad, A.; Ahsan, M.; Aielli, G.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alam, M. A.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alio, L.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alonso, F.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Ammosov, V. V.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; 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.; 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.; Arce, A. T. H.; Arfaoui, S.; Arguin, J.-F.; Argyropoulos, S.; Arik, E.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arslan, O.; Artamonov, A.; Artoni, G.; Arutinov, D.; Asai, S.; Asbah, N.; Ask, S.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Astbury, A.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Auge, E.; Augsten, K.; Aurousseau, M.; Avolio, G.; Axen, D.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Bacci, C.; Bach, A. M.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Backus Mayes, J.; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bailey, D. C.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, S.; Balek, P.; Balli, F.; Banas, E.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; 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.; Bartoldus, R.; Barton, A. E.; Bartsch, V.; Basye, A.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beale, S.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becks, K. H.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belloni, A.; Beloborodova, O. L.; 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.; Berglund, E.; Beringer, J.; Bernard, C.; Bernat, P.; Bernhard, R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Bertella, C.; Bertolucci, F.; Besana, M. I.; Besjes, G. J.; Bessidskaia, O.; Besson, N.; 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.; Bittner, B.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blazek, T.; Bloch, I.; Blocker, C.; Blocki, J.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Boddy, C. R.; Boehler, M.; Boek, J.; Boek, T. T.; Boelaert, N.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Bolnet, N. M.; Bomben, M.; Bona, M.; Boonekamp, M.; Bordoni, S.; Borer, C.; Borisov, A.; Borissov, G.; Borri, M.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Bouchami, J.; Boudreau, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozovic-Jelisavcic, I.; Bracinik, J.; Branchini, P.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Bremer, J.; Brendlinger, K.; Brenner, R.; Bressler, S.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Broggi, F.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brost, E.; Brown, G.; Brown, J.

2013-10-01

170

Analyzing powers and proton spin transfer coefficients in the elastic scattering of 800 MeV polarized protons from an L-type polarized deuteron target at small momentum transfers  

SciTech Connect

Analyzing powers and spin transfer coefficients which describe the elastic scattering of polarized protons from a polarized deuteron target have been measured. The energy of the proton beam was 800 MeV and data were taken at laboratory scattering angles of 7, 11, 14, and 16.5 degrees. One analyzing power was also measured at 180 degrees. Three linearly independent orientations of the beam polarization were used and the target was polarized parallel and antiparallel to the direction of the beam momentum. The data were taken with the high resolution spectrometer at the Los Alamos Meson Physics Facility (experiment 685). The results are compared with multiple scattering predictions based on Dirac representations of the nucleon-nucleon scattering matrices. 27 refs., 28 figs., 4 tabs.

Adams, D.L.

1986-10-01

171

Jet momentum balance independent of shear viscosity  

E-print Network

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.

R. B. Neufeld

2012-02-24

172

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

E-print Network

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 ...

Taylor, Frank E.

173

Search for new phenomena in final states with large jet multiplicities and missing transverse momentum at s? = 8 TeV proton-proton collisions using the ATLAS experiment  

E-print Network

A search is presented for new particles decaying to large numbers (7 or more) of jets, with missing transverse momentum and no isolated electrons or muons. This analysis uses 20.3 fb[superscript ?1] of pp collision data ...

Taylor, Frank E.

174

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

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 ...

Taylor, Frank E.

175

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

E-print Network

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

E. Schmutzer

2005-05-11

176

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

PubMed

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

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

2014-08-13

177

Production of large transverse momentum dileptons and photons in $pp$, $dA$ and $AA$ collisions by photoproduction processes  

E-print Network

The production of large $P_{T}$ dileptons and photons originating from photoproduction processes in $pp$, $dA$ and $AA$ collisions is calculated. We find that the contribution of dileptons and photons produced by photoproduction processes is not prominent at RHIC energies. However, the numerical results indicate that the modification of photoproduction processes becomes evident in the large $P_{T}$ region for $pp$, $dA$ and $AA$ collisions at LHC energies.

Yong-Ping Fu; Yun-De Li

2011-11-29

178

Enhanced excitonic effects in the energy loss spectra of LiF and Ar at large momentum transfer  

NASA Astrophysics Data System (ADS)

It is demonstrated that the bootstrap kernel [1] for finite values of q crucially depends upon the matrix character of the kernel and gives results of the same good quality as in the q ? 0 limit. The bootstrap kernel is further used to study the electron loss as well as the dielectric tensor for Si, LiF and Ar for various values of q. The results show that the excitonic effects in LiF and Ar are enhanced for values of q away from the ?-point. The reason for this enhancement is the interaction between the exciton and high-energy inter-band electron-hole transitions. This fact is validated by calculating the absorption spectra under the influence of an external electric field. The electron energy loss spectra are shown to change dramatically as a function of q.

Sharma, S.; Dewhurst, J. K.; Sanna, A.; Rubio, A.; Gross, E. K. U.

2012-05-01

179

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

SciTech Connect

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.

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

1997-07-16

180

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

E-print Network

Charge transfer and in-cloud structure of large-charge-moment positive lightning strokes frequency magnetic fields are analyzed to investigate the charge transfer and in-cloud structure of eight were recorded, these strokes contained large charge moment changes (1500­3200 CÁkm) capable

Cummer, Steven A.

181

Heat transfer in a coaxial-jet combustor using large-eddy simulation  

Microsoft Academic Search

In this study numerical simulations of non-premixed methane-air combustion are conducted to investigate the effects of convective heat-transfer in a coaxial-jet combustor. The turbulent flow field is simulated via large-eddy simulation (LES) on a structured, orthogonal mesh using a conservative discretization of the transport equations. Turbulence\\/chemistry interactions are described using the flamelet\\/progress-variable approach of Pierce and Moin (J. Fluid Mech.

Lee Shunn; Parviz Moin

2004-01-01

182

Transferring cold atoms in double magneto-optical trap by a continuous-wave transfer laser beam with large red detuning.  

PubMed

A novel scheme of transferring cold atoms in a double magneto-optical trap (MOT) system has been experimentally demonstrated. Cold cesium atoms trapped in a vapor-cell MOT are efficiently transferred to an ultrahigh-vacuum (UHV) MOT by a continuous-wave divergent Gaussian transfer laser beam. When large red detuning and moderate intensity are adopted for the transfer laser beam, enhancement of the recapturing of atoms in the UHV MOT is clearly observed. Using the divergent transfer laser beam (diameter of approximately 1.60 mm in the vapor-cell MOT region) with typical power of approximately 20.2 mW, up to approximately 85% of transfer efficiency is obtained when the frequency detuning is set to around -1.2 GHz, and it is not sensitive to small detuning variation. This transfer is much efficient compared with that in the case of continuous-wave near-resonance weak transfer laser beam (typical power of order of approximately 100 microW and typical frequency detuning of approximately-10 MHz) which is normally used in double-MOT experiment. The enhancement is ascribed to the guiding effect on cold atomic flux by transverse dipole potential of the large red-detuned transfer laser beam. PMID:19123554

Wang, Junmin; Wang, Jing; Yan, Shubin; Geng, Tao; Zhang, Tiancai

2008-12-01

183

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

PubMed Central

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

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

184

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

PubMed

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

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

185

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

PubMed Central

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

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

2001-01-01

186

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

NASA Astrophysics Data System (ADS)

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 fb. 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 ? 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.

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

2012-12-01

187

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

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

188

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

NASA Technical Reports Server (NTRS)

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.

Ko, William L.; Fleischer, Van Tran

2013-01-01

189

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

SciTech Connect

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.

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

190

Plasma momentum meter for momentum flux measurements  

DOEpatents

Invention comprises an instrument in which momentum flux onto a biasable target plate is transferred via a suspended quartz tube onto a sensitive force transducer--a capacitance-type pressure gauge. The transducer is protected from thermal damage, arcing and sputtering, and materials used in the target and pendulum are electrically insulating, rigid even at elevated temperatures, and have low thermal conductivity. The instrument enables measurement of small forces (10.sup.-5 to 10.sup.3 N) accompanied by high heat fluxes which are transmitted by energetic particles with 10's of eV of kinetic energy in a intense magnetic field and pulsed plasma environment.

Zonca, Fulvio (Rome, IT); Cohen, Samuel A. (Hopewell, NJ); Bennett, Timothy (Princeton, NJ); Timberlake, John R. (Allentown, NJ)

1993-01-01

191

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

SciTech Connect

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.

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

1995-12-31

192

The effect of scattering by soot aggregates on radiative transfer in large-scale hydrocarbon pool fires  

SciTech Connect

The modeling of large-scale hydrocarbon fuel fires is under investigation at Sandia National Laboratories. This work is being pursued as part of a program to determine energy transfer rates to weapon systems during fuel fire accident scenarios.

W. G. Houf

1999-08-01

193

Angular Momentum  

ERIC Educational Resources Information Center

The gyroscope in a smartphone was employed in a physics laboratory setting to verify the conservation of angular momentum and the nonconservation of rotational kinetic energy. As is well-known, smartphones are ubiquitous on college campuses. These devices have a panoply of built-in sensors. This creates a unique opportunity for a new paradigm in…

Shakur, Asif; Sinatra, Taylor

2013-01-01

194

Fractional-photon-assisted tunneling in an optical superlattice: Large contribution to particle transfer  

SciTech Connect

Fractional-photon-assisted tunneling is investigated both analytically and numerically for few interacting ultracold atoms in the double wells of an optical superlattice. This can be realized experimentally by adding periodic shaking to an existing experimental setup [Cheinet et al., Phys. Rev. Lett. 101, 090404 (2008)]. Photon-assisted tunneling is visible in the particle transfer between the wells of the individual double wells. In order to understand the physics of the photon-assisted tunneling, an effective model based on the rotating-wave approximation is introduced. The validity of this effective approach is tested for wide parameter ranges that are accessible to experiments in double-well lattices. The effective model goes well beyond previous perturbation theory approaches and is useful for investigating in particular the fractional-photon-assisted tunneling resonances. Analytic results on the level of the experimentally realizable two-particle quantum dynamics show very good agreement with the numerical solution of the time-dependent Schroedinger equation. Far from being a small effect, both the one-half-photon and the one-third-photon resonances are shown to have large effects on the particle transfer.

Esmann, Martin; Teichmann, Niklas; Weiss, Christoph [Institut fuer Physik, Carl von Ossietzky Universitaet, D-26111 Oldenburg (Germany)

2011-06-15

195

Relative antioxidant efficiency of a large series of carotenoids in terms of one electron transfer reactions.  

PubMed

The relative antioxidant efficiency, expressed as electron donating capability, of a large series of carotenoids has been studied using density functional theory. Their reactivity toward nine different radicals has been modeled as well as the electron transfer between pairs of carotenoids, one of which is present as a radical cation. The influence of the solvent polarity has also been studied. Torulene was found to be the most easily oxidized carotenoid, followed by lycopene. This higher reactivity is proposed in the present work for the first time, and the potential implications of such a finding are discussed. Since torulene has not been previously studied, compared to other carotenoids in terms of oxidation potentials, further experimental studies are suggested in order to confirm or reject this prediction. Ionization potential seems to be a magnitude calculable at low computational cost that correctly predicts the relative ease of oxidation in a series of carotenoids. The nuclear reorganization energy associated with electron-transfer reactions has been calculated in a very simple but apparently efficient way that allows computation of free energy barriers and relative rate constants in good agreement with the experimental values. In addition, an additive correction is proposed to include the effect of increasing the size of basis sets on the energies of Car(n) --> Car(n-1)(*+) processes. The general agreement between different calculated magnitudes and the corresponding available experimental data supports the predictions from this work. PMID:17941663

Galano, Annia

2007-11-01

196

Numerical modelling of shear-dependent mass transfer in large arteries  

NASA Astrophysics Data System (ADS)

A numerical scheme for the simulation of blood flow and transport processes in large arteries is presented. Blood flow is described by the unsteady 3D incompressible Navier-Stokes equations for Newtonian fluids; solute transport is modelled by the advection-diffusion equation. The resistance of the arterial wall to transmural transport is described by a shear-dependent wall permeability model. The finite element formulation of the Navier-Stokes equations is based on an operator-splitting method and implicit time discretization. The streamline upwind/Petrov-Galerkin (SUPG) method is applied for stabilization of the advective terms in the transport equation and in the flow equations. A numerical simulation is carried out for pulsatile mass transport in a 3D arterial bend to demonstrate the influence of arterial flow patterns on wall permeability characteristics and transmural mass transfer. The main result is a substantial wall flux reduction at the inner side of the curved region.

Rappitsch, Gerhard; Perktold, Karl; Pernkopf, Elisabeth

1997-10-01

197

Conjugate heat transfer with Large Eddy Simulation for gas turbine components  

NASA Astrophysics Data System (ADS)

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

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

2009-06-01

198

Passive transfer of low-molecular nonelectrolytes across deformable semipermeable membranes—I: Equations of convective-diffusion transfer of nonelectrolytes across deformable membranes of large curvature  

Microsoft Academic Search

The passive transfer of a low-molecular nonelectrolytes mixture across a semipermeable deformable membrane of large curvature\\u000a is considered. The equations obtained here make it possible to describe the concentration of species redistribution and the\\u000a change of the membrane shape.

L. I. Rubinstein

1974-01-01

199

Fluid transfers at a basement/cover interface Part II. Large-scale introduction of chlorine into the basement  

E-print Network

Fluid transfers at a basement/cover interface Part II. Large-scale introduction of chlorine primary inclusions of brines having chlorinities in the range of 3.3 to 5.5 mol Cl/kg solution, with total and accounts for the early introduction of large amounts of chlorine in the granitoid microporosity

Banks, David

200

Fluidic momentum controller  

NASA Technical Reports Server (NTRS)

Large angular control moments and torques are developed by controllably circulating a relatively small mass of liquid through small diameter pipes describing a large diameter loop. The loop, by generating and storing angular momentum, can thereby provide efficient cancellation of periodic, non-accumulating, externally induced rotational disturbances. The loop is preferably located on or near the periphery of a structure which is to be stabilized.

Maynard, Ronald S. (inventor)

1988-01-01

201

Maternal insulin sensitivity in midpregnancy does not determine birth weight after embryo transfer between large and small breed sheep.  

PubMed

Embryo transfer of large sheep breed embryos (Suffolk) into small breed ewes (Cheviot) constrains birth size, but the maternal factors influencing fetal growth restriction are unknown. We hypothesized that reciprocal embryo transfer crosses between breeds of divergent size would affect pregnancy-related development of maternal insulin resistance in midgestation, thereby influencing fetal growth. Following superovulation, embryos were surgically collected 6 d postmating and transferred to recipients on the same day. Between- and within-breed transfers were performed. Between 60 and 70 d of pregnancy overnight-fasted ewes underwent hyperinsulinemic-euglycemic clamps for assessment of insulin sensitivity. Maternal insulin sensitivity did not vary with transferred lamb breed. Overall, Cheviot ewes tended to have higher fasting glucose (P = 0.068), fasting insulin (P = 0.052), and steady-state glucose (P = 0.065) concentrations than Suffolk ewes at the stage of pregnancy studied. As expected, transferred between-breed Suffolk lambs were born lighter (P = 0.014), and transferred between-breed Cheviot lambs tended to be heavier at birth (P = 0.056) than respective lambs transferred within breed. Midgestation insulin sensitivity does not appear to be a major factor constraining growth of large breed sheep fetus transferred into smaller breed or a factor in releasing constraint in growth of a small breed fetus within a larger breed ewe. However, as embryo size is already different between transferred groups by 19 d, factors other than maternal gestational insulin resistance may determine fetal growth in this embryo transfer paradigm. PMID:25254312

Oliver, M H; Jaquiery, A L; Kenyon, P R; Pain, S J; Jenkinson, C M; Blair, H T; Derraik, J G B; Bloomfield, F H

2015-01-01

202

Position Measurements Obeying Momentum Conservation  

E-print Network

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.

Paul Busch; Leon Loveridge

2010-05-04

203

Local transfer and spectra of a diffusive field advected by large-scale incompressible flows.  

PubMed

This study revisits the problem of advective transfer and spectra of a diffusive scalar field in large-scale incompressible flows in the presence of a (large-scale) source. By "large scale" it is meant that the spectral support of the flows is confined to the wave-number region kkd is bounded from above by UkdkTheta(k,t) , where U denotes the maximum fluid velocity and Theta(k,t) is the spectrum of the scalar variance, defined as its average over the shell (k-kd,k+kd) . For a given flux, say vartheta>0 , across k>kd , this bound requires Theta(k,t)> or =(varthetaUkd)k(-1) . This is consistent with recent numerical studies and with Batchelor's theory that predicts a k(-1) spectrum (with a slightly different proportionality constant) for the viscous-convective range, which could be identified with (kd,kkappa) . Thus, Batchelor's formula for the variance spectrum is recovered by the present method in the form of a critical lower bound. The present result applies to a broad range of large-scale advection problems in space dimensions > or =2 , including some filter models of turbulence, for which the turbulent velocity field is advected by a smoothed version of itself. For this case, Theta(k,t) and vartheta are the kinetic energy spectrum and flux, respectively. PMID:18851146

Tran, Chuong V

2008-09-01

204

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

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 ...

Taylor, Frank E.

205

Angular momentum  

NASA Astrophysics Data System (ADS)

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

Shakur, Asif; Sinatra, Taylor

2013-12-01

206

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

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

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

207

Large tunneling effect on the hydrogen transfer in bis(?-oxo)dicopper enzyme: a theoretical study.  

PubMed

Type-III copper-containing enzymes have dicopper centers in their active sites and exhibit a novel capacity for activating aliphatic C-H bonds in various substrates by taking molecular oxygen. Dicopper enzyme models developed by Tolman and co-workers reveal exceptionally large kinetic isotope effects (KIEs) for the hydrogen transfer process, indicating a significant tunneling effect. In this work, we demonstrate that variational transition state theory allows accurate prediction of the KIEs and Arrhenius parameters for such model systems. This includes multidimensional tunneling based on state-of-the-art quantum-mechanical calculations of the minimum-energy path (MEP). The computational model of bis(?-oxo)dicopper enzyme consists of 70 atoms, resulting in a 204-dimensional potential energy surface. The calculated values of E(a)(H) - E(a)(D), A(H)/A(D), and the KIE at 233 K are -1.86 kcal/mol, 0.51, and 28.1, respectively, for the isopropyl ligand system. These values agree very well with experimental values within the limits of experimental error. For the representative tunneling path (RTP) at 233 K, the pre- and post-tunneling configurations are 3.3 kcal/mol below the adiabatic energy maximum, where the hydrogen travels 0.54 Å by tunneling. We found that tunneling is very efficient for hydrogen transfer and that the RTP is very different from the MEP. It is mainly heavy atoms that move as the reaction proceeds from the reactant complex to the pretunneling configuration, and the hydrogen atom suddenly hops at that point. PMID:22276687

Park, Kisoo; Pak, Youngshang; Kim, Yongho

2012-02-22

208

Plasma momentum meter for momentum flux measurements  

DOEpatents

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.

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

1993-08-24

209

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

PubMed

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

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

2014-08-13

210

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

PubMed Central

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

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

2014-01-01

211

Glenn-ht/bem Conjugate Heat Transfer Solver for Large-scale Turbomachinery Models  

NASA Technical Reports Server (NTRS)

A coupled Boundary Element/Finite Volume Method temperature-forward/flux-hack algorithm is developed for conjugate heat transfer (CHT) applications. A loosely coupled strategy is adopted with each field solution providing boundary conditions for the other in an iteration seeking continuity of temperature and heat flux at the fluid-solid interface. The NASA Glenn Navier-Stokes code Glenn-HT is coupled to a 3-D BEM steady state heat conduction code developed at the University of Central Florida. Results from CHT simulation of a 3-D film-cooled blade section are presented and compared with those computed by a two-temperature approach. Also presented are current developments of an iterative domain decomposition strategy accommodating large numbers of unknowns in the BEM. The blade is artificially sub-sectioned in the span-wise direction, 3-D BEM solutions are obtained in the subdomains, and interface temperatures are averaged symmetrically when the flux is updated while the fluxes are averaged anti-symmetrically to maintain continuity of heat flux when the temperatures are updated. An initial guess for interface temperatures uses a physically-based 1-D conduction argument to provide an effective starting point and significantly reduce iteration. 2-D and 3-D results show the process converges efficiently and offers substantial computational and storage savings. Future developments include a parallel multi-grid implementation of the approach under MPI for computation on PC clusters.

Divo, E.; Steinthorsson, E.; Rodriquez, F.; Kassab, A. J.; Kapat, J. S.; Heidmann, James D. (Technical Monitor)

2003-01-01

212

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)

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).

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

2004-01-01

213

Influence of Large Positive Dihedral on Heat Transfer to Leading Edges of Highly Swept Wings at Very High Mach Numbers  

NASA Technical Reports Server (NTRS)

A geometric study has been made of some of the effects of dihedral on the heat transfer to swept delta wings. The results of this study show that the incorporation of large positive dihedral on highly swept wings can shift, even at moderately low angles of attack, the stagnation-line heat-transfer problem from the leading edges to the axis of symmetry (ridge line). An order-of-magnitude analysis (assuming laminar flow) indicates conditions for which it may be possible to reduce the heating at the ridge line (except in the vicinity of the wing apex) to a small fraction of the leading-edge heat transfer of a flat wing at the same lift. Furthermore, conditions are indicated where dihedral reduces the leading-edge heat transfer for angles of attack less than those required to shift the stagnation line from the leading edge to the ridge line.

Cooper, Morton; Stainback, P. Calvin

1959-01-01

214

Longitudinal and Transverse Parton Momentum Distributions for Hadrons within Relativistic Constituent Quark Models  

SciTech Connect

Longitudinal and transverse parton distributions for pion and nucleon are calculated from hadron vertexes obtained by a study of form factors within relativistic quark models. The relevance of the one-gluon-exchange dominance at short range for the behavior of the form factors at large momentum transfer and of the parton distributions at the end points is stressed.

Frederico, T. [Dep. de Fisica, Instituto Tecnologico de Aeronautica, 12.228-900 Sao Jose dos Campos, Sao Paulo (Brazil); Pace, E. [Dipartimento di Fisica, Universita degli Studi di Roma 'Tor Vergata' and Istituto Nazionale di Fisica Nucleare, Sezione Tor Vergata, Via della Ricerca Scientifica 1, 00133 Roma (Italy); Pasquini, B. [Dipartimento di Fisica Nucleare e Teorica, Universita degli Studi di Pavia and Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, Pavia (Italy); Salme, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Roma, P.le A. Moro 2, 00185 Roma (Italy)

2010-08-05

215

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

E-print Network

The inclusive transverse momentum (pT) distributions of primary charged particles are measured in the pseudo-rapidity range |$\\eta$| 30 GeV/c. In peripheral collisions (70–80%), the suppression is weaker with $R_{AA}$ about 0.7 almost independent of pT. The measured nuclear modification factors are compared to other measurements and model calculations.

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

2013-01-01

216

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

PubMed Central

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

Sasaki, Kazuki; Osaki, Tsukasa; Minamino, Naoto

2013-01-01

217

Combustion and mass transfer characteristics of large carbon particles in the grid region of a fluidized-bed combustor  

SciTech Connect

A fluidized-bed coal combustor is a diluted system in which each burning coal particle is surrounded by many inert bed particles due to its low concentration in the bed. These inert particles present a major resistance to oxygen transfer. Most studies on mass transfer have been for the bubbling region; this study characterizes combustion and mass transfer phenomena in the grid region near the multi-orifice gas distributor where the gas and solids contacting is more efficient. Single particle experiments measure the combustion rates of large electrode graphite spheres fixed at various positions within the grid region. The results show that the relative importance between mass transfer and chemical kinetics in the overall combustion depend strongly on all operating variables considered such as inert particle size, superficial gas velocity and, most importantly, particle position. Inert particle size is found to determine the rate of gas leakage into the dense phase as well as the voidage distribution in the dilute phase. Based on the new definition of the grid region height determined from the reaction point of view, the experimental results are analyzed in light of theories for spouted beds and two-phase flows, and mass transfer correlations are proposed for oxygen transfer in the grid region. The results of theoretical analyses further suggest that a different description of the overall combustion phenomena is needed in the grid region. This description could be combined with some of the bubbling bed models for better prediction of the overall bed performance.

Choi, A.S.

1988-01-01

218

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

Microsoft Academic Search

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

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

219

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at root s=7 TeV with the ATLAS experiment  

SciTech Connect

This paper describes an analysis of the angular distribution of W {yields} e{nu} and W {yields} {mu}{nu} decays, using data from pp collisions at {radical}s = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb{sup -1}. Using the decay lepton transverse momentum and the missing transverse momentum, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f{sub 0}, f{sub L} and f{sub R} over two ranges of W transverse momentum (p{sub T}{sup W}): 35 < p{sub T}{sup W} < 50 GeV and p{sub T}{sup W} > 50 GeV. Good agreement is found with theoretical predictions. For p{sub T}{sup W} > 50 GeV, the values of f{sub 0} and f{sub L}-f{sub R}, averaged over charge and lepton flavour, are measured to be: f{sub 0} = 0.127 {+-} 0.030 {+-} 0.108 and f{sub L} - f{sub R} = 0.252 {+-} 0.017 {+-} 0.030, where the first uncertainties are statistical, and the second include all systematic effects.

Aad G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Acerbi, E.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Aderholz, M.; Adomeit, S.; et al.

2012-05-01

220

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

PubMed

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

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

2013-01-01

221

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

DOE PAGESBeta

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

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

2013-01-01

222

Conservation of Momentum 2  

NSDL National Science Digital Library

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

Michael Horton

2009-05-30

223

Near-field radiative transfer between two unequal sized spheres with large size disparities.  

PubMed

We compute near-field radiative transfer between two spheres of unequal radii R1 and R2 such that R2 ? 40R1. For R2 = 40R1, the smallest gap to which we have been able to compute radiative transfer is d = 0.016R1. To accomplish these computations, we have had to modify existing methods for computing near-field radiative transfer between two spheres in the following ways: (1) exact calculations of coefficients of vector translation theorem are replaced by approximations valid for the limit d ? R1, and (2) recursion relations for a normalized form of translation coefficients are derived which enable us to replace computations of spherical Bessel and Hankel functions by computations of ratios of spherical Bessel or spherical Hankel functions. The results are then compared with the predictions of the modified proximity approximation. PMID:24977544

Sasihithlu, Karthik; Narayanaswamy, Arvind

2014-06-16

224

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

PubMed Central

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

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

225

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

SciTech Connect

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

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

2001-06-17

226

Search for new phenomena in final states with large jet multiplicities and missing transverse momentum using sqrt {s} = 7 TeV pp collisions with the ATLAS detector  

NASA Astrophysics Data System (ADS)

Results are presented of a search for any particle(s) decaying to six or more jets in association with missing transverse momentum. The search is performed using 1.34fb-1 of sqrt {s} = 7 TeV proton-proton collisions recorded by the ATLAS detector during 2011. Data-driven techniques are used to determine the backgrounds in kinematic regions that require at least six, seven or eight jets, well beyond the multiplicities required in previous analyses. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a supersymmetry model (MSUGRA/CMSSM) where they extend previous constraints.

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.; Bella, L. Aperio; 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.; Galtieri, A. Barbaro; 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.; da Costa, J. Barreiro Guimarães; 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.; Becker, S.; Beckingham, M.; Becks, K. H.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Begel, M.; Harpaz, S. Behar; 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.; Ami, S. Ben; 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.; Kuutmann, E. Bergeaas; 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.; de Renstrom, P. A. Bruckman; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Buanes, T.; Bucci, F.; Buchanan, J.; Buchanan, N. J.; Buchholz, P.

2011-11-01

227

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

Microsoft Academic Search

We present the transverse momentum (pT) spectra for identified charged pions, protons and anti-protons from p+p and d+Au collisions at sNN=200 GeV. The spectra are measured around midrapidity (|y|0.5) over the range of 0.3pT10 GeV\\/c with particle identification from the ionization energy loss and its relativistic rise in the time projection chamber and time-of-flight in STAR. The charged pion and proton+anti-proton spectra

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

2006-01-01

228

Momentum harvesting techniques for solar system travel  

NASA Technical Reports Server (NTRS)

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

Willoughby, Alan J.

1990-01-01

229

Heat transfer from a horizontal finned tube bundle in bubbling fluidized beds of small and large particles  

SciTech Connect

Steady state average heat transfer coefficient measurements were made by the local thermal simulation technique in a cold, square, bubbling air-fluidized bed (0.305 m x 0.305 m) with immersed horizontal finned tube bundles (in-line and staggered) with integral 60{degree} V-thread. Studies were conducted using beds of small (average particle diameter less than 1 mm) sand particles and of large (average particle diameter greater thin 1 mm) particles (raagi, mustard, millet and coriander). The fin pitch varied from 0.8 to 5.0 mm and the fin height varied from 0.69 to 4.4 mm. The tube pitch ratios used were 1.75 and 3.5. The influence of bed particle diameter, fluidizing velocity, fin pitch, and tube pitch ratio on average heat transfer coefficient was studied. Fin pitch and bed particle diameter are the most significant parameters affecting heat transfer coefficient within the range of experimental conditions. Bed pressure drop depends only on static bed height. New direct correlations, incorporating easily measurable quantities, for average heat transfer coefficient for finned tube bundles (in-line and staggered) are proposed.

Devaru, C.B. [Jayachamaraja College of Engineering, Mysore (India). Dept. of Mechanical Engineering; Kolar, A.K. [Indian Inst. of Technology, Madras (India). Dept. of Mechanical Engineering

1995-12-31

230

Ion Momentum Spectrometry  

E-print Network

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

Bapat, Bhas

231

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

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

232

Electron Density Modeling of Large Systems Using the Transferable Atom Equivalent Method  

Microsoft Academic Search

The transferable atom equivalent (TAB) modeling method is a resource-efficient alternative to routine HF\\/SCF ab initio calculations. Electron density representations created by TAE reconstruction are designed to allow numerous molecular properties to be quickly assessed with results similar to those obtained at the HF\\/6-31 + G? level of theory. While Hartree-Fock calculations using this basis set do not provide state-of-the-art

Curt M. Breneman; Tracy R. Thompson; Marlon Rhem; Mei Dung

1995-01-01

233

Modulation transfer function for a large-area amorphous silicon image receptor  

Microsoft Academic Search

The modulation transfer function (MTF) of an amorphous silicon (aSi) sensor array was measured using proper sampling techniques to determine the edge spread function (ESF). The detector under study was a area detector (EG&G Heimann, RTM128) consisting of aSi photodiodes arranged in a square array. Two independent methods for calculating the presampling MTF were implemented, based on finely sampling the

Jonathan R. D. Earnhart; Edward L. Chaney

1997-01-01

234

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

SciTech Connect

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.

Balman, Mehmet; Kosar, Tevfik

2010-05-20

235

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  

NASA Astrophysics Data System (ADS)

A search for supersymmetry (SUSY) in events with large missing transverse momentum, jets, and at least one hadronically decaying ? lepton, with zero or one additional light lepton ( e/ ?), 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 ? are set at 54 TeV in the regions where the tilde{tau}1 is the next-to-lightest SUSY particle (tan ?>20). These limits provide the most stringent tests to date of GMSB models in a large part of the parameter space considered.

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

2012-11-01

236

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

SciTech Connect

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)

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

237

Fabrication of large-scale monocrystalline silicon micro-mirror arrays using adhesive wafer transfer bonding  

NASA Astrophysics Data System (ADS)

Today, spatial light modulators (SLMs) based on individually addressable micro-mirrors play an important role for use in DUV lithography and adaptive optics. Especially the mirror planarity and stability are important issues for these applications. Mono-crystalline silicon as mirror material offers a great possibility to combine the perfect surface with the good mechanical properties of the crystalline material. Nevertheless, the challenge is the integration of mono-crystalline silicon in a CMOS process with low temperature budget (below 450°C) and restricted material options. Thus, standard processes like epitaxial growth or re-crystallization of poly-silicon cannot be used. We will present a CMOS-compatible approach, using adhesive wafer transfer bonding with Benzocyclobutene (BCB) of a 300nm thin silicon membrane, located on a SOI-donor wafer. After the bond process, the SOI-donor wafer is grinded and spin etched to remove the handle silicon and the buried oxide layer, which results in a transfer of the mono-crystalline silicon membrane to the CMOS wafer. This technology is fully compatible for integration in a CMOS process, in order to fabricate SLMs, consisting of one million individually addressable mono-crystalline silicon micro-mirrors. The mirrors, presented here, have a size of 16×16 ?m2. Deflection is achieved by applying a voltage between the mirrors and the underlying electrodes of the CMOS electronics. In this paper, we will present the fabrication process as well as first investigations of the mirror properties.

Zimmer, Fabian; Niklaus, Frank; Lapisa, Martin; Ludewig, Thomas; Bring, Martin; Friedrichs, Martin; Bakke, Thor; Schenk, Harald; van der Wijngaart, Wouter

2009-02-01

238

Angular momentum exchange between coherent light and matter fields  

E-print Network

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.

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

2007-07-25

239

Momentum harvesting techniques for solar system travel  

NASA Technical Reports Server (NTRS)

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.

Willoughby, Alan J.

1991-01-01

240

Suppression of Charged Particle Production at Large Transverse Momentum in Central Pb-Pb Collisions at sNN = 2.76 TeV  

SciTech Connect

Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at {radical}s{sub 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{sub T} < 20 GeV/c are compared to the expectation in pp collisions at the same {radical}s{sub NN}, scaled by the number of underlying nucleon-nucleon collisions. The comparison is expressed in terms of the nuclear modification factor R{sub AA}. The result indicates only weak medium effects (R{sub AA} {approx} 0.7) in peripheral collisions. In central collisions, R{sub AA} reaches a minimum of about 0.14 at p{sub T} = 6--7 GeV/c and increases significantly at larger p{sub T}. The measured suppression of high-p{sub T} particles is stronger than that observed at lower collision energies, indicating that a very dense medium is formed in central Pb-Pb collisions at the LHC.

Aamodt, K. [University of Oslo, Norway; Awes, Terry C [ORNL; Read Jr, Kenneth F [ORNL; Silvermyr, David O [ORNL; ALICE, Collaboration [The

2011-01-01

241

Large-area inverse opal structures in a bulk chalcogenide glass by spin-coating and thin-film transfer  

NASA Astrophysics Data System (ADS)

Large (cm × cm), uniform-thickness areas of an inverse-opal photonic crystal and an inverse-opal monolayer were fabricated in a high-refractive-index As30S70 chalcogenide glass. We have developed an effective low-cost, solution-based process for fabrication of photonic structures in chalcogenide glass from silica-colloidal-crystal thin-film templates (multi- and monolayer). The chalcogenide-glass solution is spin-coated over the silica-opal film template and the infilled composite structure (chalcogenide/opal) is then lifted-off and transferred onto the chalcogenide-glass disc at 225 °C, followed by removal of the template in hydrofluoric acid. The extra step introduced in this work (lift-off and transfer) allows a reproducible and large-area structure to be fabricated on a bulk chalcogenide glass. Complete infilling of the silica template is possible due to the nano-colloidal nature (particle size 2-8 nm) of the chalcogenide-glass solution and effective solvent release from the spin-coated chalcogenide film during post-annealing. The resulting chalcogenide-glass inverse-opal multilayer exhibits a Bragg peak at 670 nm with a reflectance 70%, while the inverse-opal monolayer shows anti-reflectance behaviour <2% in the near-infrared region (1215-1660 nm).

Kohoutek, T.; Orava, J.; Strizik, L.; Wagner, T.; Greer, A. L.; Bardosova, M.; Fudouzi, H.

2013-12-01

242

Angular momentum in QGP holography  

NASA Astrophysics Data System (ADS)

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

McInnes, Brett

2014-10-01

243

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

NASA Astrophysics Data System (ADS)

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

Ziapour, Behrooz M.; Dehnavi, Resam

2014-11-01

244

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

NASA Astrophysics Data System (ADS)

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.

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

2015-02-01

245

Transition from Charge-Transfer to Largely Locally Excited Exciplexes, from Structureless to Vibrationally Structured Emissions.  

PubMed

Exciplexes of 9,10-dicyanoanthracene (DCA) with alkylbenzene donors in cyclohexane show structureless emission spectra, typical of exciplexes with predominantly charge-transfer (CT) character, when the donor has a relatively low oxidation potential (Eox ), e.g. hexamethylbenzene (HMB). With increasing Eox and stronger mixing with a locally excited (LE) state, vibrational structure begins to appear with 1,2,3,5-tetramethylbenzene and becomes prominent with p-xylene (p-Xy). A simple theoretical model reproduces the spectra and the radiative rate constants, and it reveals several surprises: Even in this nonpolar solvent, the fractional CT character of a highly mixed exciplex varies widely in response to fluctuations in the microscopic environment. Environments that favor the LE (or CT) state contribute more to the blue (or red) side of the overall spectrum. It is known that sparsely substituted benzene radical cations, e.g., p-Xy(•+) , are stabilized more in acetonitrile than the heavily substituted HMB(•+) . Remarkably, ion pairing with DCA(•-) in cyclohexane leads to even larger differences in the stabilization of these radical cations. The spectra of the low-Eox donors are almost identical except for displacements that approximately equal the differences in Eox , even though the exciplexes have varying degrees of CT character. These similarities result from compensation among several nonobvious, but quantified factors. PMID:25363042

Young, Ralph H; Feinberg, Adam M; Dinnocenzo, Joseph P; Farid, Samir

2014-11-01

246

Modulation transfer function for a large-area amorphous silicon image receptor.  

PubMed

The modulation transfer function (MTF) of an amorphous silicon (aSi) sensor array was measured using proper sampling techniques to determine the edge spread function (ESF). The detector under study was a 10 cm2 area detector (EG&G Heimann, RTM128) consisting of 128 x 128 aSi photodiodes arranged in a square array. Two independent methods for calculating the presampling MTF were implemented, based on finely sampling the ESF measurements produced using 40 kV x-rays from a Faxitron microfocal spot x-ray tube. The two calculations of the detector's presampling MTF are in excellent agreement, and are within 20% at the Nyquist frequency when compared with the ideal MTF based only on the size of the detector elements. ESF measurements were also made at 6 MV on a Siemens MD-2 linear accelerator. A calculation of the system presampling MTF was performed which included effects from the linear accelerator source, the lead block used to create the high contrast edge, and the aSi detector response. PMID:9434305

Earnhart, J R; Chaney, E L

1997-12-01

247

Modulation transfer function for a large-area amorphous silicon image receptor  

NASA Astrophysics Data System (ADS)

The modulation transfer function (MTF) of an amorphous silicon (aSi) sensor array was measured using proper sampling techniques to determine the edge spread function (ESF). The detector under study was a area detector (EG&G Heimann, RTM128) consisting of aSi photodiodes arranged in a square array. Two independent methods for calculating the presampling MTF were implemented, based on finely sampling the ESF measurements produced using 40 kV x-rays from a Faxitron microfocal spot x-ray tube. The two calculations of the detector's presampling MTF are in excellent agreement, and are within 20% at the Nyquist frequency when compared with the ideal MTF based only on the size of the detector elements. ESF measurements were also made at 6 MV on a Siemens MD-2 linear accelerator. A calculation of the system presampling MTF was performed which included effects from the linear accelerator source, the lead block used to create the high contrast edge, and the aSi detector response.

Earnhart, Jonathan R. D.; Chaney, Edward L.

1997-12-01

248

Defect-enhanced charge transfer by ion-solid interactions in SiC using large-scale ab initio molecular dynamics simulations.  

PubMed

Large-scale ab initio molecular dynamics simulations of ion-solid interactions in SiC reveal that significant charge transfer occurs between atoms, and defects can enhance charge transfer to surrounding atoms. The results demonstrate that charge transfer to and from recoiling atoms can alter the energy barriers and dynamics for stable defect formation. The present simulations illustrate in detail the dynamic processes for charged defect formation. The averaged values of displacement threshold energies along four main crystallographic directions are smaller than those determined by empirical potentials due to charge-transfer effects on recoil atoms. PMID:19659244

Gao, Fei; Xiao, Haiyan; Zu, Xiaotao; Posselt, Matthias; Weber, William J

2009-07-10

249

Introducing Electromagnetic Field Momentum  

ERIC Educational Resources Information Center

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…

Hu, Ben Yu-Kuang

2012-01-01

250

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

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

251

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

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

Rob Stoll; Fernando Porté-Agel

2006-01-01

252

Large Eddy Simulations of Turbulent Flow and Heat Transfer in Three-Dimensional Lid-Driven Shallow Cavities  

NASA Astrophysics Data System (ADS)

Large-eddy simulations (LES) of turbulent flow and heat transfer in three-dimensional lid-driven cavities of aspect ratios (AR) of 1, 2 and 4 are carried out at Reynolds numbers of 5000, 10000 and 20000. The governing equations are box-filtered implicitly by a finite volume scheme and are solved using a fractional-step method. Subgrid scale stresses are represented using Yoshizawa's SGS kinetic-energy transport equation. It was found that the three-dimensional vortical structures play an important role in the heat transfer characteristics at the confining walls. For AR=1, the highest levels of temperature fluctuations occur within the free shear layer between the primary vortex and the downstream secondary eddy, similar to that observed for the velocity field. Mean and RMS velocity profiles were found to be in good agreement with published experimental data. For higher aspect ratio cases the upstream secondary eddy (USE) was found to bifurcate at high Reynolds number as observed from the streamlines of mean velocity field at the mid-span plane. Interestingly for AR=4, the bifurcations of the USE further increased to five at Re=20000 which may be attributable to the Kelvin-Helmholtz type instability at the free shear layer between the Primary eddy (PE) and USE. Profiles of urms fluctuations and vrms fluctuations are studied.

Joardar, Arindom; Vanka, Surya; Jacobi, Anthony

2006-11-01

253

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

NASA Technical Reports Server (NTRS)

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

Maghami, Peiman G.; Giesy, Daniel P.

1998-01-01

254

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

PubMed Central

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

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

2014-01-01

255

Nucleon spin structure at low momentum transfers  

SciTech Connect

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

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

2010-10-01

256

Spatialized N budgets in a large agricultural Mediterranean watershed: high loading and low transfer  

NASA Astrophysics Data System (ADS)

Despite the particular management practices and climate characteristics of the Mediterranean regions, the literature dealing with N budgets in large catchments subjected to Mediterranean conditions is scarce. The present study aims to deepen our knowledge on the N cycle within the Ebro River Basin (NE Spain) by means of two different approaches: (1) calculating a global N budget in the Ebro River Basin and (2) calculating a series of detailed regional budgets at higher geographical resolution. N inputs and outputs were spatialized by creating a map based on the most detailed information available. Fluvial and atmospheric N export was estimated together with N retention. The Ebro River Basin annually receives a relatively high amount of new N (5118 kg N km-2 yr-1), mostly in the form of synthetic fertilizers (50 %). Although it is a highly productive catchment, the net N input as food and feed import is also high (33 %). Only 8 % of this N is finally exported to the delta zone. Several territorial units characterized by different predominant uses (rainfed agriculture, irrigated agriculture and pastures) have differentiated N dynamics. However, due to the high density of irrigation channels and reservoirs that characterize Mediterranean basins, N retention is very high in all of them (median value, 92 %). These results indicate that problems of eutrophication due to N delivery in the coastal area may not be too severe but that high N retention values may instead lead to problems within the catchment, such as pollution of aquifers and rivers, as well as high atmospheric emissions. The most promising management measures are those devoted to reducing agricultural surpluses such as balanced N fertilization and low N livestock feeding.

Lassaletta, L.; Romero, E.; Billen, G.; Garnier, J.; García-Gómez, H.; Rovira, J. V.

2011-08-01

257

Spatialized N budgets in a large agricultural Mediterranean watershed: high loading and low transfer  

NASA Astrophysics Data System (ADS)

Despite the particular management practices and climate characteristics of the Mediterranean regions, the literature dealing with N budgets in large catchments subjected to Mediterranean conditions is scarce. The present study aims to deepen our knowledge on the N cycle within the Ebro River Basin (NE Spain) by means of two different approaches: (1) calculating a global N budget in the Ebro River Basin and (2) calculating a series of detailed regional budgets at higher geographical resolution. N inputs and outputs were spatialized by creating a map based on the most detailed information available. Fluvial and atmospheric N export was estimated together with N retention. The Ebro River Basin annually receives a relatively high amount of new N (5118 kg N km-2 yr-1), mostly in the form of synthetic fertilizers (50%). Although it is a highly productive catchment, the net N input as food and feed import is also high (33%). Only 8% of this N is finally exported to the delta zone. Several territorial units characterized by different predominant uses (rainfed agriculture, irrigated agriculture and pastures) have differentiated N dynamics. However, due to the high density of irrigation channels and reservoirs that characterize Mediterranean catchments, N retention is very high in all of them (median value, 91%). These results indicate that problems of eutrophication due to N delivery in the coastal area may not be too severe but that high N retention values may instead lead to problems within the catchment, such as pollution of aquifers and rivers, as well as high atmospheric emissions. The most promising management measures are those devoted to reducing agricultural surpluses through a better balanced N fertilization.

Lassaletta, L.; Romero, E.; Billen, G.; Garnier, J.; García-Gómez, H.; Rovira, J. V.

2012-01-01

258

Electron Scattering From High-Momentum Neutrons in Deuterium  

SciTech Connect

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.

A.V. Klimenko; S.E. Kuhn

2005-10-12

259

TDRSS momentum unload planning  

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

260

Combustion and mass transfer characteristics of large carbon particles in the grid region of a fluidized-bed combustor  

Microsoft Academic Search

A fluidized-bed coal combustor is a diluted system in which each burning coal particle is surrounded by many inert bed particles due to its low concentration in the bed. These inert particles present a major resistance to oxygen transfer. Most studies on mass transfer have been for the bubbling region; this study characterizes combustion and mass transfer phenomena in the

1988-01-01

261

A compact magnetic bearing for gimballed momentum wheel  

NASA Technical Reports Server (NTRS)

A three axis controlled magnetic bearing and its application to a momentum wheel are described. The four divided stators provide a momentum wheel with high reliability, low weight, large angular momentum storage capacity, and gimbal control. Those characteristics are desirable for spacecraft attitude control.

Yabu-Uchi, K.; Inoue, M.; Akishita, S.; Murakami, C.; Okamoto, O.

1983-01-01

262

Angular momentum radio  

NASA Astrophysics Data System (ADS)

Wireless communication amounts to encoding information onto physical observables carried by electromagnetic (EM) fields, radiating them into surrounding space, and detecting them remotely by an appropriate sensor connected to an informationdecoding receiver. Each observable is second order in the fields and fulfills a conservation law. In present-day radio only the EM linear momentum observable is fully exploited. A fundamental physical limitation of this observable, which represents the translational degrees of freedom of the charges (typically an oscillating current along a linear antenna) and the fields, is that it is single-mode. This means that a linear-momentum radio communication link comprising one transmitting and one receiving antenna, known as a single-input-single-output (SISO) link, can provide only one transmission channel per frequency (and polarization). In contrast, angular momentum, which represents the rotational degrees of freedom, is multi-mode, allowing an angular-momentum SISO link to accommodate an arbitrary number of independent transmission channels on one and the same frequency (and polarization). We describe the physical properties of EM angular momentum and how they can be exploited, discuss real-world experiments, and outline how the capacity of angular momentum links may be further enhanced by employing multi-port techniques, i.e., the angular momentum counterpart of linear-momentum multiple-input-multiple-output (MIMO).

Thidé, B.; Tamburini, F.; Then, H.; Someda, C. G.; Mari, Elletra; Parisi, G.; Spinello, F.; Romanato, Fra

2014-02-01

263

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

A search for supersymmetry (SUSY) in events with large missing transverse momentum, jets, at least one hadronically decaying tau lepton and zero or one additional light leptons (electron/muon), has been performed using 20.3 fb$^{-1}$ of proton-proton collision data at $\\sqrt{s} = 8$ TeV recorded with the ATLAS detector at the Large Hadron Collider. No excess above the Standard Model background expectation is observed in the various signal regions and 95% confidence level upper limits on the visible cross section for new phenomena are set. The results of the analysis are interpreted in several SUSY scenarios, significantly extending previous limits obtained in the same final states. In the framework of minimal gauge-mediated SUSY breaking models, values of the SUSY breaking scale $\\Lambda$ below 63 TeV are excluded, independently of tan$\\beta$. Exclusion limits are also derived for an mSUGRA/CMSSM model, in both the R-parity-conserving and R-parity-violating case. A further interpretation is presented in a framework of natural gauge mediation, in which the gluino is assumed to be the only light coloured sparticle and gluino masses below 1090 GeV are excluded.

ATLAS Collaboration

2014-10-22

264

Mobilisation and remobilisation of a large archetypal pathogenicity island of uropathogenic Escherichia coli in vitro support the role of conjugation for horizontal transfer of genomic islands  

PubMed Central

Background A substantial amount of data has been accumulated supporting the important role of genomic islands (GEIs) - including pathogenicity islands (PAIs) - in bacterial genome plasticity and the evolution of bacterial pathogens. Their instability and the high level sequence similarity of different (partial) islands suggest an exchange of PAIs between strains of the same or even different bacterial species by horizontal gene transfer (HGT). Transfer events of archetypal large genomic islands of enterobacteria which often lack genes required for mobilisation or transfer have been rarely investigated so far. Results To study mobilisation of such large genomic regions in prototypic uropathogenic E. coli (UPEC) strain 536, PAI II536 was supplemented with the mobRP4 region, an origin of replication (oriVR6K), an origin of transfer (oriTRP4) and a chloramphenicol resistance selection marker. In the presence of helper plasmid RP4, conjugative transfer of the 107-kb PAI II536 construct occured from strain 536 into an E. coli K-12 recipient. In transconjugants, PAI II536 existed either as a cytoplasmic circular intermediate (CI) or integrated site-specifically into the recipient's chromosome at the leuX tRNA gene. This locus is the chromosomal integration site of PAI II536 in UPEC strain 536. From the E. coli K-12 recipient, the chromosomal PAI II536 construct as well as the CIs could be successfully remobilised and inserted into leuX in a PAI II536 deletion mutant of E. coli 536. Conclusions Our results corroborate that mobilisation and conjugal transfer may contribute to evolution of bacterial pathogens through horizontal transfer of large chromosomal regions such as PAIs. Stabilisation of these mobile genetic elements in the bacterial chromosome result from selective loss of mobilisation and transfer functions of genomic islands. PMID:21943043

2011-01-01

265

Flow and Heat Transfer at a Nonlinearly Shrinking Porous Sheet:The Case of Asymptotically Large Powerlaw Shrinking Rates  

NASA Astrophysics Data System (ADS)

The boundary layer flow and heat transfer of a viscous fluid over a nonlinear permeable shrinking sheet in a thermally stratified environment is considered. The sheet is assumed to shrink in its own plane with an arbitrary power-law velocity proportional to the distance from the stagnation point. The governing differential equations are first transformed into ordinary differential equations by introducing a new similarity transformation. This is different from the transform commonly used in the literature in that it permits numerical solutions even for asymptotically large values of the power-law index, m. The coupled non-linear boundary value problem is solved numerically by an implicit finite difference scheme known as the Keller- Box method. Numerical computations are performed for a wide variety of power-law parameters (1 < m < 100,000) so as to capture the effects of the thermally stratified environment on the velocity and temperature fields. The numerical solutions are presented through a number of graphs and tables. Numerical results for the skin-friction coefficient and the Nusselt number are tabulated for various values of the pertinent parameters.

Prasad, K. V.; Vajravelu, K.; Pop, I.

2013-08-01

266

Pressure drop of two-phase helium flowing in a large solenoidal magnet cooling path and a long transfer line  

NASA Astrophysics Data System (ADS)

The pressure drop of two-phase helium flowing in a 64 m cooling path of a magnet and a 58 m connecting transfer line was investigated. A large thin superconducting solenoidal magnet, which was developed for the SDC detector (Solenoidal Detector Collaboration for the former SSC project), was used for this experiment. The magnet is 3.8 m in diameter, 2 m in length with a total cold mass of 4.5 tons. It was cooled by two-phase helium flow passing through a serpentine cooling path. The pressure drops of single-phase gas helium flow during cool down and two-phase helium flow in steady cooling were measured and compared with predictions. The measured pressure drop of single-phase helium agreed well with the prediction; however, the measured pressure drop of two-phase helium was much larger than the predictions based on separated and homogeneous flow models. In the high mass-flow region of two-phase flow, slight pressure oscillations were observed in the inlet, outlet and differential pressures of the magnet. The magnet temperature was stable and not affected by those oscillations.

Haruyama, T.; Araoka, O.; Doi, Y.; Kasami, K.; Makida, Y.; Suzuki, S.; Tanaka, K.; Yamamoto, A.

267

W Boson production at large transverse momentum.  

E-print Network

(1997). [4] N. Kidonakis, G. Oderda, and G. Sterman, Nucl. Phys. B531, 365 (1998). [5] E. Laenen, G. Oderda, and G. Sterman, Phys. Lett. B 438, 173 (1998). [6] N. Kidonakis, Phys. Rev. D 64, 014009 (2001); N. Kidonakis, E. Laenen, S. Moch, and R. Vogt...

Kidonakis, Nikolaos; Sabio Vera, Agustin

268

A high-yield two-step transfer printing method for large-scale fabrication of organic single-crystal devices on arbitrary substrates.  

PubMed

Single-crystal organic nanostructures show promising applications in flexible and stretchable electronics, while their applications are impeded by the large incompatibility with the well-developed photolithography techniques. Here we report a novel two-step transfer printing (TTP) method for the construction of organic nanowires (NWs) based devices onto arbitrary substrates. Copper phthalocyanine (CuPc) NWs are first transfer-printed from the growth substrate to the desired receiver substrate by contact-printing (CP) method, and then electrode arrays are transfer-printed onto the resulting receiver substrate by etching-assisted transfer printing (ETP) method. By utilizing a thin copper (Cu) layer as sacrificial layer, microelectrodes fabricated on it via photolithography could be readily transferred to diverse conventional or non-conventional substrates that are not easily accessible before with a high transfer yield of near 100%. The ETP method also exhibits an extremely high flexibility; various electrodes such as Au, Ti, and Al etc. can be transferred, and almost all types of organic devices, such as resistors, Schottky diodes, and field-effect transistors (FETs), can be constructed on planar or complex curvilinear substrates. Significantly, these devices can function properly and exhibit closed or even superior performance than the device counterparts fabricated by conventional approach. PMID:24942458

Deng, Wei; Zhang, Xiujuan; Pan, Huanhuan; Shang, Qixun; Wang, Jincheng; Zhang, Xiaohong; Zhang, Xiwei; Jie, Jiansheng

2014-01-01

269

A High-yield Two-step Transfer Printing Method for Large-scale Fabrication of Organic Single-crystal Devices on Arbitrary Substrates  

NASA Astrophysics Data System (ADS)

Single-crystal organic nanostructures show promising applications in flexible and stretchable electronics, while their applications are impeded by the large incompatibility with the well-developed photolithography techniques. Here we report a novel two-step transfer printing (TTP) method for the construction of organic nanowires (NWs) based devices onto arbitrary substrates. Copper phthalocyanine (CuPc) NWs are first transfer-printed from the growth substrate to the desired receiver substrate by contact-printing (CP) method, and then electrode arrays are transfer-printed onto the resulting receiver substrate by etching-assisted transfer printing (ETP) method. By utilizing a thin copper (Cu) layer as sacrificial layer, microelectrodes fabricated on it via photolithography could be readily transferred to diverse conventional or non-conventional substrates that are not easily accessible before with a high transfer yield of near 100%. The ETP method also exhibits an extremely high flexibility; various electrodes such as Au, Ti, and Al etc. can be transferred, and almost all types of organic devices, such as resistors, Schottky diodes, and field-effect transistors (FETs), can be constructed on planar or complex curvilinear substrates. Significantly, these devices can function properly and exhibit closed or even superior performance than the device counterparts fabricated by conventional approach.

Deng, Wei; Zhang, Xiujuan; Pan, Huanhuan; Shang, Qixun; Wang, Jincheng; Zhang, Xiaohong; Zhang, Xiwei; Jie, Jiansheng

2014-06-01

270

Angular momentum in the Local Group  

SciTech Connect

We briefly review models for the Local Group and the acquisition of its angular momentum. We describe early attempts to understand the origin of the spin of the galaxies discussing the hypothesis that the Local Group has little angular momentum. Finally we show that using Peebles` least action principle there should be a rather large amount of orbital angular momentum compared to the magnitude of the spin of its galaxies. Therefore the Local Group cannot be thought as tidally isolated. Using Peebles` trajectories we give a possible set of trajectories for Local Group galaxies which would predict their spin.

Dunn, A. [Cambridge Univ. (United Kingdom). Inst. of Astronomy; Laflamme, R. [Los Alamos National Lab., NM (United States)

1994-04-01

271

Large-scale mass transfers related to pressure solution creep-faulting interactions in mudstones: Driving processes and impact of lithification degree  

NASA Astrophysics Data System (ADS)

Where normal faulting is associated with PSC (Pressure Solution Creep), it generates evolutions in petrophysical properties of mudstones like chalk: decrease in reservoir qualities and transport properties in the deformed zones adjacent to the fault plane and increase (or no change) in reservoir qualities and transport properties in the outermost deformed zones. These modifications result from large-scale mass transfers linked to a transport of solutes through the pore space over distances of several grains within decimeter or larger zones (open systems at the grain scale). In the lithified mudstones, these large-scale mass transfers consist in a mass redistribution from the outermost deformed zones (mass and volume loss) to the deformed zones adjacent to the fault planes (mass gain). In the weakly lithified mudstones, the mass redistribution occurs in an opposite direction. A deeper understanding of these large-scale mass redistributions is essential because the PSC-faulting interactions and the associated petrophysical modifications can be a key topic in several geological applications (oil and gas migration and entrapment in mudstone reservoirs, anthropogenic waste storage, carbon dioxyde geosequestration). The results of two studies about mass transfers and volume changes induced by natural fault systems in “white chalk” allowed to point out that two driving processes control the large-scale mass transfers during PSC-faulting interactions: the advective mass transport related to pore fluid flows and the large-scale diffusive mass transport linked to chemical potential gradients. The present contribution also highlights that the lithification degree of the host material plays a key role in the large-scale mass transfers related to PSC-faulting interactions by controlling (1) the spatial distribution of voids induced by the deformation, (2) the particle displacement on the fault plane and in the adjacent zones and (3) the petrophysical properties of the host material in some zones.

Richard, J.

2014-02-01

272

Reversal of momentum relaxation.  

PubMed

A new phenomenon of momentum relaxation reversal has been discovered experimentally and explained theoretically for dipolar spin waves in magnetic garnet films. It is shown that the process of momentum relaxation, caused by the scattering of a signal wave on defects, can be reversed, and the signal can be restituted after it left the scattering region. The reversal of momentum relaxation is achieved by frequency-selective parametric amplification of a narrow band of scattered waves having low group velocities and frequencies close to the frequency of the original signal wave. The phenomenon can be used for the development of a new type of active microwave delay lines. PMID:11384381

Melkov, G A; Kobljanskyj, Y V; Serga, A A; Tiberkevich, V S; Slavin, A N

2001-05-21

273

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

E-print Network

Large Electron Transfer Rate Effects from the Duschinsky Mixing of Vibrations Gerald M. Sando and nontotally symmetric vibrations are very important. The Duschinsky effect arises when two electronic states of solvent and an effective vibrational reorganization energy that is not predictable by simple models

274

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

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

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

275

Stock Market Momentum Model  

NSDL National Science Digital Library

The Stock Market Momentum Model uses the change in price to predict a future change. In trading jargon, this change in price is referred to as momentum. Mathematically, the model can be considered to be a causal high pass filter of degree 1. In this model, the user can analyze the momentum indicator response as it relates to the daily closing price of a few popular stock indices. The upper plot shows the closing price and a smoothed price (in blue) if the filter is turned on. The lower panel is the momentum indicator. Users can drag a cursor left and right to compare values on these two graphs. Below, the cursor is dropped at a point where the momentum shifts from negative to positive values, which happens to be the beginning of a bull market. A trader would want to buy at these opportunities and sell when the momentum becomes negative. Time is measured in years and in each year there are approximately 253 business days.

Mohorn, Matthew

2013-04-16

276

Momentum distributions: An overview  

SciTech Connect

There have been several excellent reviews of momentum-distribution research in particular subject areas of physics such as electronic systems and nuclear systems. However, it is the commonality of interests, difficulties, and prospects across all of physics, along with certain pivotal advances, which led to the organization of an interdisciplinary Workshop on Momentum Distributions held at Argonne National Laboratory on October 24--26, 1988. The purpose of this overview is to explain why scientists with such diverse backgrounds have been brought together at this meeting, to introduce and discuss the common elements of momentum-distribution studies, and to establish a common language. We hope to facilitate an appreciation of the more specialized articles which follow in these proceedings. We begin by summarizing the general properties of momentum distributions. Differences and similarities of atomic, electronic, and nuclear many-body systems are examined, in terms of characteristic lengths and energies, relative importance of exchange, and the nature of the two-particle interactions. We continue with a brief commentary on the microscopic methods used to calculate n(p) from first principles. Thereafter, the discussion focuses on the ideas, techniques, and issues involved in the experimental determination of the momentum distribution: deep-inelastic scattering, the impulse approximation, Y-scaling, final-state effects, and scale breaking. Finally, some typical examples of theoretical and experimental momentum distributions will be presented and compared, for a variety of systems. 63 refs., 16 figs.

Sokol, P.E.; Silver, R.N.; Clark, J.W.

1989-01-01

277

Frame assisted H2O electrolysis induced H2 bubbling transfer of large area graphene grown by chemical vapor deposition on Cu  

NASA Astrophysics Data System (ADS)

An improved technique for transferring large area graphene grown by chemical vapor deposition on copper is presented. It is based on mechanical separation of the graphene/copper by H2 bubbles during H2O electrolysis, which only takes a few tens of seconds while leaving the copper cathode intact. A semi-rigid plastic frame in combination with thin polymer layer span on graphene gives a convenient way of handling- and avoiding wrinkles and holes in graphene. Optical and electrical characterizations prove the graphene quality is better than that obtained by traditional wet etching transfer. This technique appears to be highly reproducible and cost efficient.

de la Rosa, César J. Lockhart; Sun, Jie; Lindvall, Niclas; Cole, Matthew T.; Nam, Youngwoo; Löffler, Markus; Olsson, Eva; Teo, Kenneth B. K.; Yurgens, August

2013-01-01

278

Accessing high momentum states in lattice QCD  

NASA Astrophysics Data System (ADS)

Two measures are defined to evaluate the coupling strength of smeared interpolating operators to hadronic states at a variety of momenta. Of particular interest is the extent to which strong overlap can be obtained with individual high-momentum states. This is vital to exploring hadronic structure at high-momentum transfers on the lattice and addressing interesting phenomena observed experimentally. We consider a novel idea of altering the shape of the smeared operator to match the Lorentz contraction of the probability distribution of the high-momentum state and show a reduction in the relative error of the two-point function by employing this technique. Our most important finding is that the overlap of the states becomes very sharp in the smearing parameters at high momenta, and fine tuning is required to ensure strong overlap with these states.

Roberts, Dale S.; Kamleh, Waseem; Leinweber, Derek B.; Mahbub, M. S.; Menadue, Benjamin J.

2012-10-01

279

Accessing High Momentum States In Lattice QCD  

E-print Network

Two measures are defined to evaluate the coupling strength of smeared interpolating operators to hadronic states at a variety of momenta. Of particular interest is the extent to which strong overlap can be obtained with individual high-momentum states. This is vital to exploring hadronic structure at high momentum transfers on the lattice and addressing interesting phenomena observed experimentally. We consider a novel idea of altering the shape of the smeared operator to match the Lorentz contraction of the probability distribution of the high-momentum state, and show a reduction in the relative error of the two-point function by employing this technique. Our most important finding is that the overlap of the states becomes very sharp in the smearing parameters at high momenta and fine tuning is required to ensure strong overlap with these states.

Dale S. Roberts; Waseem Kamleh; Derek B. Leinweber; M. S. Mahbub; Benjamin J. Menadue

2012-06-26

280

Accessing High Momentum States In Lattice QCD  

E-print Network

Two measures are defined to evaluate the coupling strength of smeared interpolating operators to hadronic states at a variety of momenta. Of particular interest is the extent to which strong overlap can be obtained with individual high-momentum states. This is vital to exploring hadronic structure at high momentum transfers on the lattice and addressing interesting phenomena observed experimentally. We consider a novel idea of altering the shape of the smeared operator to match the Lorentz contraction of the probability distribution of the high-momentum state, and show a reduction in the relative error of the two-point function by employing this technique. Our most important finding is that the overlap of the states becomes very sharp in the smearing parameters at high momenta and fine tuning is required to ensure strong overlap with these states.

Roberts, Dale S; Leinweber, Derek B; Mahbub, M S; Menadue, Benjamin J

2012-01-01

281

Momentum-space Argonne V18 interaction  

NASA Astrophysics Data System (ADS)

This paper gives a momentum-space representation of the Argonne V18 potential as an expansion in products of spin-isospin operators with scalar coefficient functions of the momentum transfer. Two representations of the scalar coefficient functions for the strong part of the interaction are given. One is as an expansion in an orthonormal basis of rational functions and the other as an expansion in Chebyshev polynomials on different intervals. Both provide practical and efficient representations for computing the momentum-space potential that do not require integration or interpolation. Programs based on both expansions are available as supplementary material. Analytic expressions are given for the scalar coefficient functions of the Fourier transform of the electromagnetic part of the Argonne V18. A simple method for computing the partial-wave projections of these interactions from the operator expressions is also given.

Veerasamy, S.; Polyzou, W. N.

2011-09-01

282

Transverse momentum distributions and nuclear effects  

NASA Astrophysics Data System (ADS)

A distorted spin-dependent spectral function for 3He is considered to take care of the final state interaction in the extraction of the quark transverse-momentum distributions in the neutron from semi-inclusive deep inelastic electron scattering off polarized 3He at finite momentum transfers. The generalization of the analysis in a Poincaré covariant framework within the light-front dynamics is outlined. The definition of the light-front spin-dependent spectral function for a J=1/2 system, as the nucleon, allows us to show that within the light-front dynamics and in the valence approximation only three of the six leading twist T-even transverse-momentum distributions are independent.

Pace, Emanuele; Del Dotto, Alessio; Kaptari, Leonid; Rinaldi, Matteo; Salmè, Giovanni; Scopetta, Sergio

2015-01-01

283

The Angular Momentum Dichotomy  

NASA Astrophysics Data System (ADS)

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.).

Teklu, Adelheid; Remus, Rhea-Silvia; Dolag, Klaus; Burkert, Andreas

2015-02-01

284

QM Momentum Measurement Program  

NSDL National Science Digital Library

The QM Momentum Measurement program displays the time evolution of the position-space wave function and can be used to simulate the quantum-mechanical measurement of momentum. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the qm_measurement_p.jar file will run the program if Java is installed. The default wave function is an equal-mix four-state superposition in the infinite square well. QM Momentum Measurement is one of 18 Open Source Physics programs that model time-dependent quantum mechanics using an energy eigenstate expansion. Other programs provide additional visualizations. They can be found by searching ComPADRE for Open Source Physics, OSP, or Superposition.

Christian, Wolfgang

2008-04-17

285

QM Momentum Space Program  

NSDL National Science Digital Library

The QM Momentum Space program displays the time evolution of the position-space wave function and the associated momentum-space wave function. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the qm_fft.jar file will run the program if Java is installed. The default wave function is a Gaussian wave packet in a harmonic oscillator. Additional states and other potential energy functions can be specified using the Display | Switch GUI menu item. QM Momentum Space is one of 18 Open Source Physics programs that model time-dependent quantum mechanics using an energy eigenstate expansion. Other programs provide additional visualizations. They can be found by searching ComPADRE for Open Source Physics, OSP, or Superposition.

Christian, Wolfgang

2008-04-17

286

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)

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.

Blair, M. F.

1991-01-01

287

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

SciTech Connect

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.

Blair, M.F.

1991-11-01

288

Angular momentum conservation demonstration  

NSDL National Science Digital Library

A short article describing the fabrication and operation of a simple angular momentum conservation demonstration. The demonstration is based on a Lazy Susan, and cylindrical brass weights tied with a nylon string. The string can be pulled or released changing the radius or rotation of the weights.

Berg, Richard E.; Anders, Robert E.

2010-12-23

289

A Second Large Plasmid Encodes Conjugative Transfer and Antimicrobial Resistance in O119:H2 and Some Typical O111 Enteropathogenic Escherichia coli Strains? §  

PubMed Central

A novel and functional conjugative transfer system identified in O119:H2 enteropathogenic Escherichia coli (EPEC) strain MB80 by subtractive hybridization is encoded on a large multidrug resistance plasmid, distinct from the well-described EPEC adherence factor (EAF) plasmid. Variants of the MB80 conjugative resistance plasmid were identified in other EPEC strains, including the prototypical O111:NM strain B171, from which the EAF plasmid has been sequenced. This separate large plasmid and the selective advantage that it confers in the antibiotic era have been overlooked because it comigrates with the virulence plasmid on conventional gels. PMID:17573481

Nwaneshiudu, Adaobi I.; Mucci, Tania; Pickard, Derek J.; Okeke, Iruka N.

2007-01-01

290

The momentum map representation of images  

E-print Network

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.

M. Bruveris; F. Gay-Balmaz; D. D. Holm; T. S. Ratiu

2009-12-16

291

The SKA as a Doorway to Angular Momentum  

E-print Network

Angular momentum is one of the most fundamental physical quantities governing galactic evolution. Differences in the colours, morphologies, star formation rates and gas fractions amongst galaxies of equal stellar/baryon mass M are potentially widely explained by variations in their specific stellar/baryon angular momentum j. The enormous potential of angular momentum science is only just being realised, thanks to the emergence of the first simulations of galaxies with converged spins, paralleled by a dramatic increase in kinematic observations. Such observations are still challenged by the fact that most of the stellar/baryon angular momentum resides at large radii. In fact, the radius that maximally contributes to the angular momentum of an exponential disk (3Re-4Re) is twice as large as the radius that maximally contributes to the disk mass; thus converged measurements of angular momentum require either extremely deep IFS data or, alternatively, kinematic measurements of neutral atomic hydrogen (HI), which ...

Obreschkow, D; Popping, A; Power, C; Quinn, P; Staveley-Smith, L

2015-01-01

292

102?k large area atom interferometers.  

PubMed

We demonstrate atom interferometers utilizing a novel beam splitter based on sequential multiphoton Bragg diffractions. With this sequential Bragg large momentum transfer (SB-LMT) beam splitter, we achieve high contrast atom interferometers with momentum splittings of up to 102 photon recoil momenta (102?k). To our knowledge, this is the highest momentum splitting achieved in any atom interferometer, advancing the state-of-the-art by an order of magnitude. We also demonstrate strong noise correlation between two simultaneous SB-LMT interferometers, which alleviates the need for ultralow noise lasers and ultrastable inertial environments in some future applications. Our method is intrinsically scalable and can be used to dramatically increase the sensitivity of atom interferometers in a wide range of applications, including inertial sensing, measuring the fine structure constant, and detecting gravitational waves. PMID:22026831

Chiow, Sheng-wey; Kovachy, Tim; Chien, Hui-Chun; Kasevich, Mark A

2011-09-23

293

AMORE: Applied Momentum for Orbital Refuse Elimination  

NASA Astrophysics Data System (ADS)

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.

Wolfson, M.

2014-09-01

294

Evaluating HapMap SNP data transferability in a large-scale genotyping project involving 175 cancer-associated genes  

Microsoft Academic Search

One of the many potential uses of the HapMap project is its application to the investigation of complex disease aetiology\\u000a among a wide range of populations. This study aims to assess the transferability of HapMap SNP data to the Spanish population\\u000a in the context of cancer research. We have carried out a genotyping study in Spanish subjects involving 175 candidate

Gloria Ribas; Anna González-Neira; Antonio Salas; Roger L. Milne; Ana Vega; Begoña Carracedo; Emilio González; Eva Barroso; Lara P. Fernández; Patricio Yankilevich; Mercedes Robledo; Ángel Carracedo; Javier Benítez

2006-01-01

295

Molecular supercollisions: Evidence for large energy transfer in the collisional relaxation of highly vibrationally excited pyrazine by CO2  

NASA Astrophysics Data System (ADS)

The temperature dependence of the collisional quenching of highly vibrationally excited pyrazine by CO2 molecules has been investigated for the temperature range 243-364 K using high resolution time resolved diode laser spectroscopy. Particular emphasis is placed on vibration to rotation-translation (V?R/T) energy transfer which leaves the CO2 vibrations unexcited and occurs predominantly through short-range repulsive forces. Vibrationally hot pyrazine is prepared by 248 nm excimer laser pumping, followed by rapid radiationless transitions to the ground electronic state. For the range of experimental cell temperatures used here, the nascent rotational population distributions of the 0000 ground state of CO2 resulting from collisions with hot pyrazine were probed at short times following excitation of pyrazine by the excimer laser pulse. The CO2 translational recoil velocity was also measured for individual rotational levels of the 0000 state. In addition, temperature dependent rate constants and probabilities were determined for energy transfer from the vibrationally hot pyrazine into individual rotational levels of the 0000 state of CO2. The rotational distributions, velocity recoils, and quenching rates exhibit a very weak temperature dependence for production of CO2 high J states, indicating that the CO2 molecules involved in these energy transfer events originate from rotational levels only slightly greater than the thermal mean J value. Based on these results, values for ?E, the energy transfer from hot pyrazine to CO2 resulting in final CO2 0000 states J=58 through J=82, are estimated to range from 2550 to 7090 cm-1 in a single collision.

Mullin, Amy S.; Michaels, Chris A.; Flynn, George W.

1995-04-01

296

Investigation of Large-Amplitude Motions of H_5^+ and the Dynamics of the Proton Transfer Between H_3^+ and H_2  

NASA Astrophysics Data System (ADS)

Protonated hydrogen dimer, or H_5^+, is the intermediate of the proton-transfer reaction between H_3^+ and H_2. The dynamics of this reaction has been postulated to play a significant role in the non-thermal H/D and ortho-/para- ratio in the interstellar clouds. As a weakly-bound, fluxional molecular ion, H_5^+ has a very rich vibrational spectrum. The large-amplitude vibrational motions of H_5^+ make theoretical studies interesting but challenging. This work aims at understanding how these large-amplitude motions are reflected in the dynamics of the proton transfer between H_3^+ and H_2, or between the deuterated analogues of these two species. The shared-proton stretch mode is closely related to the proton-transfer process and is thus of particular interest. Diffusion Monte Carlo calculations of minimum energy paths are performed for the ground state and selected excited states, in order to explore how the vibrational energetics and wavefunctions evolve as H_5^+ dissociates into H_3^+ and H_2. The effects of deuteration on the structures and properties are also investigated. C. E. Hinkle and A. B. McCoy, J. Phys. Chem. Lett., 1, 562 (2010)

Lin, Zhou; McCoy, Anne B.

2013-06-01

297

Newtonian Mechanics: Momentum  

NSDL National Science Digital Library

This web page provides an elementary introduction and overview of momentum and a discussion of recoil, conservation and energy. A lesson plan and related pages are also linked to this page. This is part of an extensive web site, "From Stargazers to Starships", that uses the topics of space exploration and space science to introduce topics in physics and astronomy. Translations in French, Italian and Spanish are available.

Stern, David

2008-09-03

298

Effects of Volkov functions in laser-assisted electron momentum spectroscopy  

NASA Astrophysics Data System (ADS)

We consider theoretically an electron-impact ionization process at high impact energy and large momentum transfer in the presence of laser radiation. The target is modeled as an electron bound by a harmonic potential. Dressing of the target state by the laser field is treated exactly. Laser-assisted differential cross sections are calculated using either Volkov functions or plane waves for incoming and outgoing electrons. It is shown that even in the case of the low-frequency and weak-intensity laser radiation the effect of the field on these electrons can dramatically influence the shape of the cross sections.

Bulychev, Andrey A.; Kouzakov, Konstantin A.; Popov, Yuri V.

2013-02-01

299

Factors influencing the efficiency of generating genetically engineered pigs by nuclear transfer: multi-factorial analysis of a large data set  

PubMed Central

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

2013-01-01

300

Electric Field in a Double Layer and the Imparted Momentum  

Microsoft Academic Search

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,

A. Fruchtman

2006-01-01

301

The Book of Phyz: Momentum  

NSDL National Science Digital Library

This item is a chapter from "The Book of Phyz," an educator's guide to teaching introductory high school physics. It features easily understood content support in the fundamentals of momentum, the relationship of Newton's Second Law and momentum, elastic and inelastic collision, and conservation of momentum. Related student activities, experiments, and assessments are included in the materials.

Baird, Dean

2006-07-18

302

Quasilocal linear momentum in black-hole binaries  

SciTech Connect

We propose a quasilocal formula for the linear momentum of black-hole horizons inspired by the formalism of quasilocal horizons. We test this formula using two complementary configurations: (i) by calculating the large orbital linear momentum of the two black holes in an unequal-mass, zero-spin, quasicircular binary and (ii) by calculating the very small recoil momentum imparted to the remnant of the head-on collision of an equal-mass, anti-aligned-spin binary. We obtain results consistent with the horizon trajectory in the orbiting case, and consistent with the net radiated linear momentum for the much smaller head-on recoil velocity.

Krishnan, Badri [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, Am Muehlenberg 1, D-14476 Golm (Germany); Lousto, Carlos O.; Zlochower, Yosef [Center for Computational Relativity and Gravitation, School of Mathematical Sciences, Rochester Institute of Technology, 78 Lomb Memorial Drive, Rochester, New York 14623 (United States)

2007-10-15

303

Pumping angular momentum by driven chaotic scattering  

E-print Network

Chaotic scattering with an internal degree of freedom and the possibility to generate directed transport of angular momentum is studied in a specific model, a magnetic dipole moving in a periodically modulated magnetic field confined to a compact region in space. We show that this system is an irregular scatterer in large parts of its parameter space. If in addition all spatio-temporal symmetries are broken, directed transport of mass as well as angular momentum occurs. The sensitive parameter dependence of the corresponding currents includes frequent sign reversals. Zeros of either quantity entail the exclusive occurrence of the other and thus give rise in particular to angular-momentum separation without mass transport as a classical analogue of spin-polarized currents.

T. Dittrich; F. L. Dubeibe

2008-04-29

304

Experimental verification of bioheat transfer theories: measurement of temperature profiles around large artificial vessels in perfused tissue.  

PubMed

The verification of thermal models for use in hyperthermia treatment planning is essential. We investigated the heat transfer between a single vessel and the surrounding vascularised tissue, comparing the conventional bioheat transfer theory and the recently developed keff model using analytical and numerical methods. A plastic tube inserted into the tissue of an isolated perfused organ served as an artificial vessel. This enabled us to vary the blood flow in the vessel and in the tissue independently. The organ used was a bovine kidney, turned into a perfused tissue phantom using an alcohol fixation technique. The temperature profile within the tissue was mapped with constantan-manganin thermocouple wire sensors with a total diameter of 50 microns. The temperature profile relative to the temperature difference between the vessel and organ was measured; increased perfusion caused a reduction of the vessel wall temperature but did not affect the width of the profile. Studying the transient tissue temperature after a step-wise change of the blood temperature in the vessel revealed a faster diffusion of heat at higher perfusion rates. These facts are in accordance with the keff model, but not with the conventional heat-sink theory. PMID:2385622

Crezee, J; Lagendijk, J J

1990-07-01

305

Climate Momentum Simulation  

NSDL National Science Digital Library

The Climate Momentum Simulation allows users to quickly compare the resulting sea level rise, temperature change, atmospheric CO2, and global CO2 emissions from six different policy options: 1) Business As Usual, 2) March 2009 Country Proposals, 3) Flatten CO2 emissions by 2025, 4) 29% below 2009 levels by 2040, 5) 80% reduction of global fossil fuel plus a 90% reduction in land use emissions by 2050, and 6) 95 reduction of CO2 emissions by 2020). Based on the more complex C-ROADS simulator.

Drew Drew Jones

306

Noise-Immune Conjugate Large-Area Atom Interferometers  

NASA Astrophysics Data System (ADS)

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.

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

2009-07-01

307

Changes in angular momentum during the tennis serve.  

PubMed

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

Bahamonde, R E

2000-08-01

308

Gas mass transfer for stratified flows  

SciTech Connect

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.

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

1995-07-01

309

Gas mass transfer for stratified flows  

SciTech Connect

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.

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

1995-06-01

310

Transverse Momentum Structure of Diffractive DIS Models  

E-print Network

The transverse momentum distribution of the diffractive final state provides an interesting test of models of diffractive deep-inelastic scattering at HERA. We present a comparison of several colour-singlet exchange models with thrust transverse momentum data from a recent H1 analysis. We also study the effect of constraints imposed on the kinematically-accessible phase space by data selection cuts and find that, as a result of the pseudo-rapidity cut which is used by H1 to select diffractive events, there is no dijet contribution at low transverse momenta. We are able to fit the large transverse momentum part of the data with a two-gluon dijet model. The results of this analysis are compared with a previous study of large pseudo-rapidity gap structure function data, and we discuss ways in which one might reconcile the results of the two analyses. We conclude that a significant small-$\\beta$ 3-jet contribution is probably required to explain the data, and show that the combination of a two-gluon dijet model and an exponentially-decaying thrust transverse momentum distribution provides a good fit over the entire kinematic range of the thrust data.

J. C. Williams

1999-10-13

311

Modeling of the cross-beam energy transfer with realistic inertial-confinement-fusion beams in a large-scale hydrocode  

NASA Astrophysics Data System (ADS)

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.

Colaïtis, A.; Duchateau, G.; Ribeyre, X.; Tikhonchuk, V.

2015-01-01

312

A Large-Scale Allosteric Transition in Cytochrome P450 3A4 Revealed by Luminescence Resonance Energy Transfer (LRET)  

PubMed Central

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

Sineva, Elena V.; Rumfeldt, Jessica A. O.; Halpert, James R.; Davydov, Dmitri R.

2013-01-01

313

Ultrafast coherent control of angular momentum during a one-photon excitation  

SciTech Connect

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.

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

314

MINET (momentum integral network) code documentation  

SciTech Connect

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.

Van Tuyle, G J; Nepsee, T C; Guppy, J G [Brookhaven National Lab., Upton, NY (USA)

1989-12-01

315

Momentum and Its Conversion  

NSDL National Science Digital Library

The Physics Classroom presents this tutorial on momentum and its conversion. The three laws are three laws are explained and their application to the analysis of the motion of objects in one dimension is discussed. There are four separate lessons which provide an activity and then an assessment exercise in order for students to check their understanding of the concept (s). Some of the key topics included here are: state of motion, force, gravitational pull, vector quantity, force, Newton's second law of motion, and Newton's third law of motion. The tutorial is geared toward high school students, but it is also great review material for college physics students or anyone needing a refresher course in vectors.

316

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)

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.

Blair, Michael F.; Anderson, Olof L.

1989-01-01

317

Density functional theory calculations of energy-loss carbon near-edge spectra of small diameter armchair and zigzag nanotubes: Core-hole, curvature, and momentum-transfer orientation effects  

NASA Astrophysics Data System (ADS)

We perform density functional theory calculations on a series of armchair and zigzag nanotubes of diameters less than 1 nm using the all-electron full-potential(-linearized)-augmented-plane-wave method. Emphasis is laid on the effects of curvature, the electron-beam orientation, and the inclusion of the core hole on the carbon electron-energy-loss K edge. The electron-energy-loss near-edge spectra of all the studied tubes show strong curvature effects compared to that of flat graphene. The curvature-induced ?-? hybridization is shown to have a more drastic effect on the electronic properties of zigzag tubes than on those of armchair tubes. We show that the core-hole effect must be accounted for in order to correctly reproduce electron-energy-loss measurements. We also find that the energy-loss near-edge spectra of these carbon systems are dominantly dipole selected and that they can be expressed simply as a proportionality with the local momentum projected density of states, thus portraying the weak energy dependence of the transition matrix elements. Compared to graphite, we report a reduction in the anisotropy as seen on the energy-loss near-edge spectra of carbon nanotubes.

Titantah, J. T.; Jorissen, K.; Lamoen, D.

2004-03-01

318

Force As A Momentum Current  

SciTech Connect

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.

Munera, Hector A. [International Center for Physics (CIF, Centro Internacional de Fisica), Apartado 4948, Bogota (Colombia)

2010-07-28

319

Sprinkler Head Revisited: Momentum, Forces, and Flows in Machian Propulsion  

ERIC Educational Resources Information Center

Many experimenters, starting with Ernst Mach in 1883, have reported that if a device alternately sucks in and then expels a surrounding fluid, it moves in the same direction as if it only expelled fluid. This surprising phenomenon, which we call "Machian propulsion", is explained by conservation of momentum: the outflow efficiently transfers…

Jenkins, Alejandro

2011-01-01

320

A study of the validity of the efficiency transfer method to calculate the peak efficiency using ?-ray detectors at extremely large distances  

NASA Astrophysics Data System (ADS)

The full-energy peak efficiency (FEPE) curves of the (2? × 2? and 3? × 3?) NaI (Tl) detectors were measured at seven different axial positions from their surfaces. The calibration process was done using radioactive point sources, which produce a wide energy range from 59.53 up to 1,408.01 keV. This work has been undertaken to explain the effects of source energy and sourcE-to-detector distance on the detector efficiency calculations. The study provides an empirical formula to calculate FEPE based on the efficiency transfer method for different detectors using the effective solid angle ratio at very large distances and for higher energies. A remarkable agreement between the measured and calculated efficiencies for the detectors at the sourcE-to-detector distances <35 cm and above that slight difference was observed.

El-Khatib, Ahmed M.; Badawi, Mohamed S.; Elzaher, Mohamed A.; Thabet, Abouzeid A.

2014-04-01

321

Large IncHI2-plasmids encode extended-spectrum ?-lactamases (ESBLs) in Enterobacter spp. bloodstream isolates, and support ESBL-transfer to Escherichia coli.  

PubMed

We investigated the prevalence of extended-spectrum ?-lactamases (ESBLs) in Enterobacter spp. bloodstream isolates from 19 hospital laboratories in Norway during 2011. A total of 62/230 (27%) isolates were resistant to third-generation cephalosporins and four (1.7%) were ESBL-positive; blaCTX -M-15 (n = 3) and blaSHV -12 (n = 1). This is comparable to the prevalence of ESBLs in clinical isolates of Escherichia coli and Klebsiella pneumoniae in Norway during the same period. All ESBL-positive isolates were multidrug resistant (MDR) and harboured plasmid-mediated quinolone resistance. Three isolates supported transfer of large IncHI2-plasmids harbouring ESBL- and MDR-encoding genes to E. coli recipients by in vitro conjugation. PMID:23800169

Nilsen, E; Haldorsen, B C; Sundsfjord, A; Simonsen, G S; Ingebretsen, A; Naseer, U; Samuelsen, O

2013-11-01

322

Intrinsic Angular Momentum of Light.  

ERIC Educational Resources Information Center

Derives a familiar torque-angular momentum theorem for the electromagnetic field, and includes the intrinsic torques exerted by the fields on the polarized medium. This inclusion leads to the expressions for the intrinsic angular momentum carried by the radiation traveling through a charge-free medium. (Author/MA)

Santarelli, Vincent

1979-01-01

323

MOMENTUM LIQUIDATION UNDER PARTIAL INFORMATION  

E-print Network

MOMENTUM LIQUIDATION UNDER PARTIAL INFORMATION ERIK EKSTR¨OM1 AND MARTIN VANNEST°AL Abstract information show that the assumption that the disappearance of the momentum effect is triggered by observable that performed well in the past typically continue to yield positive returns on a relatively short time horizon

Ekström, Erik

324

LABORATORY V CONSERVATION OF MOMENTUM  

E-print Network

Lab V - 1 LABORATORY V CONSERVATION OF MOMENTUM In this lab you will use conservation of momentum enough information for a complete analysis of collisions in terms of forces. Conservation principles can of the complicated details of the collision process itself, but conservation of energy alone is usually not enough

Minnesota, University of

325

Recruiting and retaining geoscience students at a large public university: Balancing the needs of first-time freshman and upper-division transfer students  

NASA Astrophysics Data System (ADS)

The Department of Geological Sciences at California State University, Fullerton (CSUF) is one of the largest geology programs in the state. Approximately 4,000 students at CSUF take general education geology classes; this provides a large pool from which to recruit undergraduate students for either the Geology B.S. or Earth Sciences B.A. offered by the department. The department has seen a dramatic increase in majors over the last decade, from a low of 28 majors in 2002 to more than 110 in 2012. This increase does not appear to be driven by growth in the oil industry; in a recent survey of CSUF geoscience (BS or BA) students, 15% of respondents indicated an interest in a career in petroleum. The department has engaged in aggressive recruitment and outreach efforts over the last decade, with activities ranging from earthquake preparedness rallies in conjunction with the annual California ShakeOut, to an emerging high school and community college intern program at the department's paleontology curation facility. Despite these efforts, the majority of CSUF geoscience students declared the geology major after taking an introductory physical geology course either at CSUF or a local community college. Over the last ten years, approximately 50% of the geoscience majors at CSUF transferred from a community college. Among the geoscience students who began their career at CSUF, only one third had declared a geoscience major in their freshman year. Over two thirds of geoscience majors at CSUF declared their major after completing more than 60 units. The strong tendency for students to declare a geoscience major late in their career poses significant challenges to students' ability to graduate in a timely manner. To mitigate this problem, the department has an aggressive advising program, wherein students attend mandatory advising with a faculty member every semester. The department is also working closely with community college partners to improve the preparation of transfer students through advising partnerships facilitated by the NSF-sponsored STEM2 program, and through active collaboration in implementing a geology "Associate's Degree-for-Transfer" at community colleges under the framework of California's Student Transfer Achievement Reform Act (SB 1440).

Bowman, D. D.; Clemens-Knott, D.

2012-12-01

326

Transverse angular momentum of photons  

NASA Astrophysics Data System (ADS)

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.

Aiello, Andrea; Marquardt, Christoph; Leuchs, Gerd

2010-05-01

327

Average Transverse Momentum Quantities Approaching the Lightfront  

NASA Astrophysics Data System (ADS)

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.

Boer, Daniël

2015-01-01

328

Energy-momentum tensor correlators and viscosity  

E-print Network

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.

Harvey B. Meyer

2008-09-30

329

Momentum Transport in Granular Flows  

E-print Network

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.

Gregg Lois; Anael Lemaitre; Jean M. Carlson

2006-02-10

330

Mercury in aquatic forage of large herbivores: impact of environmental conditions, assessment of health threats, and implications for transfer across ecosystem compartments.  

PubMed

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

Bergman, Brenda Gail; Bump, Joseph K

2014-05-01

331

Oxygen atom transfer reactions of iridium and osmium complexes: theoretical study of characteristic features and significantly large differences between these two complexes.  

PubMed

Oxygen atom transfer reaction between ML(3)=O and ML(3) (L = 2,4,6-trimethylphenyl (Mes) for M = Ir and L = 2,6-diisopropylphenylimide (NAr) for M = Os) was theoretically investigated by DFT method. The optimized geometry of (Mes)(3)Ir-O-Ir(Mes)(3) agrees well with the experimental one, although those of (CH(3))(3)Ir-O-Ir(CH(3))(3) and Ph(3)Ir-O-IrPh(3) are much different from the experimental one of the Mes complex. These results indicate that the bulky ligand plays important roles to determine geometry of the mu-oxo dinuclear Ir complex. Theoretical study of the real systems presents clear pictures of these oxygen atom transfer reactions, as follows: In the Ir reaction system, (i) the mu-oxo bridged dinuclear complex is more stable than the infinite separation system in potential energy surface, indicating this is incomplete oxygen atom transfer reaction which does not occur at very low temperature, (ii) unsymmetrical transition state is newly found, in which one Ir-O distance is longer than the other one, (iii) unsymmetrical local minimum is also newly found between the transition state and the infinite separation system, and (iv) activation barrier (E(a)) is very small. In the Os reaction system, (v) the transition state is symmetrical, while no intermediate is observed unlike the Ir reaction system, and (vi) E(a) is very large. These results are consistent with the experimental results that the reaction rapidly occurs in the Ir system but very slowly in the Os system, and that the mu-oxo bridged dinuclear intermediate is detected in the Ir system but not in the Os system. To elucidate the reasons of these differences between Ir and Os systems, the E(a) value is decomposed into the nuclear and electronic factors. The former is the energy necessary to distort ML(3) and ML(3)=O moieties from their equilibrium geometries to those in the transition state. The latter depends on donor-acceptor interaction between ML(3)=O and ML(3). The nuclear factor is much larger in the Os system than in the Ir system and it contributes to about 70% of the difference in E(a). The energy gap between the donor orbital of ML(3) and the acceptor orbital of ML(3)=O is much larger in the Os system than in the Ir system, which also contributes to the lower E(a) value of the Ir system than that of the Os system. PMID:19670885

Ishikawa, Atsushi; Nakao, Yoshihide; Sato, Hirofumi; Sakaki, Shigeyoshi

2009-09-01

332

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

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,

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

1987-01-01

333

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

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.}

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

334

A Compact Ring Design with Tunable Momentum Compaction  

SciTech Connect

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.

Sun, Y.; /SLAC; ,

2012-05-17

335

On the nanoscale transmission of quantum angular momentum  

NASA Astrophysics Data System (ADS)

The electromagnetic propagation of angular momentum associated with photon spin has evolved into a subject of much broader remit, following the theoretical and experimental realization of optical beams that can convey quantized orbital angular momentum. The possibility of transmitting such information over nanoscale distances raises numerous issues. For example, it is known that electron spin can be relayed by near-field communication between exciton states in quantum dot assemblies; the question arises, can orbital angular momentum be conveyed in a similar way? There are fundamentally important technicalities surrounding such a prospect, representing potentially serious constraints on the viability of angular momentum transfer between electronically distinct components in structured nanomaterials. To resolve these issues it is necessary to interrogate the detailed form of near-field electromagnetic coupling of the relevant transition multipoles. The emerging results exhibit novel connections between angular momentum content in the near-field. The analysis leads to a conclusion that there are specific limitations on the nanoscale transmission of quantum angular momentum, with challenging implications for quantum optical data transmission.

Andrews, David L.

2010-08-01

336

Localizing the energy and momentum of linear gravity  

SciTech Connect

A framework is developed which quantifies the local exchange of energy and momentum between matter and the linearized gravitational field. We derive the unique gravitational energy-momentum tensor consistent with this description, and find that this tensor only exists in the harmonic gauge. Consequently, nearly all the gauge freedom of our framework is naturally and unavoidably removed. The gravitational energy-momentum tensor is then shown to have two exceptional properties: (a) it is gauge-invariant for gravitational plane-waves, (b) for arbitrary transverse-traceless fields, the energy-density is never negative, and the energy-flux is never spacelike. We analyze in detail the local gauge-invariant energy-momentum transferred between the gravitational field and an infinitesimal point-source, and show that these invariants depend only on the transverse-traceless components of the field. As a result, we are led to a natural gauge-fixing program which at last renders the energy-momentum of the linear gravitational field completely unambiguous, and additionally ensures that gravitational energy is never negative nor flows faster than light. Finally, we calculate the energy-momentum content of gravitational plane-waves, the linearized Schwarzschild spacetime (extending to arbitrary static linear spacetimes) and the gravitational radiation outside two compact sources: a vibrating rod, and an equal-mass binary.

Butcher, Luke M.; Lasenby, Anthony [Astrophysics Group, Cavendish Laboratory, J J Thomson Avenue, Cambridge, CB3 0HE (United Kingdom); Kavli Institute for Cosmology, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Hobson, Michael [Astrophysics Group, Cavendish Laboratory, J J Thomson Avenue, Cambridge, CB3 0HE (United Kingdom)

2010-11-15

337

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)

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

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

2014-02-01

338

Momentum Confinement at Low Torque  

SciTech Connect

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.

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

339

Nucleon Momentum Distributions From a Modified Scaling Analysis of Inclusive Electron-Nucleus Scattering  

E-print Network

Inclusive electron scattering from nuclei at low momentum transfer (corresponding to x>1) and moderate Q^2 is dominated by quasifree scattering from nucleons. In the impulse approximation, the cross section can be directly connected to the nucleon momentum distribution via the scaling function F(y). The breakdown of the y-scaling assumptions in certain kinematic regions have prevented extraction of nucleon momentum distributions from such a scaling analysis. With a slight modification to the y-scaling assumptions, it is found that scaling functions can be extracted which are consistent with the expectations for the nucleon momentum distributions.

J. Arrington

2003-06-13

340

A fast and simple algorithm for the calculation of convective heat transfer by large vessels in three-dimensional inhomogeneous tissues.  

PubMed

A fast and simple algorithm has been presented for the calculation of time-dependent temperature distributions in inhomogeneous vascularized tissue. Three-dimensional anatomical data of tissues and vessel structures are decomposed into elementary cubic nodes by a special digitizing routine with vessels represented by connected strings of vessel nodes. Vessel cross sections may be irregular shaped and/or tapered. Conductive and convective heat transfer was calculated through use of the heat balance technique on each cubic node resulting in an explicit finite difference computational scheme. Employing a three time level scheme, the Fourier stability criterion is circumvented allowing arbitrary time steps to be defined in the algorithm. Time steps as large as 100 times the Fourier restricted one still result in stable and convergent calculations of the stationary temperature distribution. Vessels with different flows and diameters are incorporated by performing a vessel specific second discretization step in time. Using the new algorithm as a mathematical tool the thermal equilibration length of vessel segments have been established under a broad range of geometrical and flow conditions. Validation followed from comparing transient and stationary temperature distributions derived by the proposed algorithm to those from an accurate cylindrical numerical model. Predicted values for the thermal equilibration lengths are compared to an analytical expression and phantom experiments. The algorithm is incorporated in a thermal model being the main part of our hyperthermia treatment planning system. PMID:1874532

Mooibroek, J; Lagendijk, J J

1991-05-01

341

Effects of large mass transfer and statistical decay on ternary breakup in the reaction U238+Au197 at 15A MeV  

NASA Astrophysics Data System (ADS)

The ternary breakup mechanism of U238+Au197 at 15A MeV has been investigated by a hybrid model that combines the improved quantum molecular dynamics (ImQMD) model together with a statistical code gemini++. The results are in good agreement with the experimental data and indicate that in peripheral reactions, ternary breakup in this reaction results from quasi-U statistical fission while for central and semicentral collisions it can be understood by a two-step mechanism: deep-inelastic collision (DIC) followed by a sequential binary breakup of one of the DIC products. In the process of DIC, there is a large mass transfer from Au to U to form transuranium. Due to the low fission barrier, such transuranium nuclei will decay into stable light nuclei through various fission modes. An event-by-event analysis shows that the second breakup mainly occurs in the deexcitation process and most of the ternary breakup events are from semicentral and peripheral collisions that correspond to deep inelastic and quasi-elastic reactions, respectively.

Jiang, Xiang; Yan, Shiwei

2014-08-01

342

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.  

PubMed

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. PMID:24463635

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

2014-03-01

343

Evidence for the role of horizontal transfer in generating pVT1, a large mosaic conjugative plasmid from the clam pathogen, Vibrio tapetis.  

PubMed

The marine bacterium Vibrio tapetis is the causative agent of the brown ring disease, which affects the clam Ruditapes philippinarum and causes heavy economic losses in North of Europe and in Eastern Asia. Further characterization of V. tapetis isolates showed that all the investigated strains harbored at least one large plasmid. We determined the sequence of the 82,266 bp plasmid pVT1 from the CECT4600(T) reference strain and analyzed its genetic content. pVT1 is a mosaic plasmid closely related to several conjugative plasmids isolated from Vibrio vulnificus strains and was shown to be itself conjugative in Vibrios. In addition, it contains DNA regions that have similarity with several other plasmids from marine bacteria (Vibrio sp., Shewanella sp., Listonella anguillarum and Photobacterium profundum). pVT1 contains a number of mobile elements, including twelve Insertion Sequences or inactivated IS genes and an RS1 phage element related to the CTXphi phage of V. cholerae. The genetic organization of pVT1 underscores an important role of horizontal gene transfer through conjugative plasmid shuffling and transposition events in the acquisition of new genetic resources and in generating the pVT1 modular organization. In addition, pVT1 presents a copy number of 9, relatively high for a conjugative plasmid, and appears to belong to a new type of replicon, which may be specific to Vibrionaceae and Shewanelleacae. PMID:21326607

Erauso, Gaël; Lakhal, Fatma; Bidault-Toffin, Adeline; Le Chevalier, Patrick; Bouloc, Philippe; Paillard, Christine; Jacq, Annick

2011-01-01

344

Phase transfer membrane supported liquid-liquid-liquid microextraction combined with large volume sample injection capillary electrophoresis-ultraviolet detection for the speciation of inorganic and organic mercury.  

PubMed

In this paper, a novel sample pretreatment technique termed phase transfer based liquid-liquid-liquid microextraction (PT-LLLME) was proposed for the simultaneous extraction of inorganic and organic mercury species. In PT-LLLME, an intermediate solvent (acetonitrile) was added into the donor phase to improve the contacting between target mercury species and complexing reagent. Meanwhile, a membrane supported (MS)-LLLME unit was designed to realize the PT-LLLME procedure. By using nylon membrane as supporting carrier, larger than 50 ?L of acceptor solution could be hung up. Following PT/MS-LLLME, the acceptor solutions were directly analyzed by large volume sample stacking capillary electrophoresis/ultraviolet detection (LVSS-CE/UV). Accordingly, a new method of PT/MS-LLLME combined with LVSS-CE/UV was developed for the simultaneous speciation of inorganic and organic mercury species. Parameters affecting the extraction efficiency of PT/MS-LLLME were investigated in details. Under the optimized conditions, enrichment factors (EFs) ranging from 160- to 478-fold were obtained for the extraction of target mercury species by PT/MS-LLLME. By combining PT/MS-LLLME with LVSS-CE/UV, EFs were magnified up to 12,138-fold and the limits of detection (at a signal-to-noise ratio of 3) were at sub ppb level. The established approach of PT/MS-LLLME-LVSS-CE/UV was successfully applied to simultaneous determination of inorganic and organic mercury species in biological samples and environmental water samples. PMID:22098933

Li, Pingjing; Zhang, Xing; Hu, Bin

2011-12-30

345

INTERNAL GRAVITY WAVES IN MASSIVE STARS: ANGULAR MOMENTUM TRANSPORT  

SciTech Connect

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.

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

346

Momentum dissipation and effective theories of coherent and incoherent transport  

E-print Network

We study heat transport in two systems without momentum conservation: a hydrodynamic system, and a holographic system with spatially dependent, massless scalar fields. When momentum dissipates slowly, there is a well-defined, coherent collective excitation in the AC heat conductivity, and a crossover between sound-like and diffusive transport at small and large distance scales. When momentum dissipates quickly, there is no such excitation in the incoherent AC heat conductivity, and diffusion dominates at all distance scales. For a critical value of the momentum dissipation rate, we compute exact expressions for the Green's functions of our holographic system due to an emergent gravitational self-duality, similar to electric/magnetic duality, and SL(2,R) symmetries. We extend the coherent/incoherent classification to examples of charge transport in other holographic systems: probe brane theories and neutral theories with non-Maxwell actions.

Richard A. Davison; Blaise Goutéraux

2014-11-04

347

Internal Gravity Waves in Massive Stars: Angular Momentum Transport  

NASA Astrophysics Data System (ADS)

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.

Rogers, T. M.; Lin, D. N. C.; McElwaine, J. N.; Lau, H. H. B.

2013-07-01

348

Momentum dissipation and effective theories of coherent and incoherent transport  

NASA Astrophysics Data System (ADS)

We study heat transport in two systems without momentum conservation: a hydrodynamic system, and a holographic system with spatially dependent, massless scalar fields. When momentum dissipates slowly, there is a well-defined, coherent collective excitation in the AC heat conductivity, and a crossover between sound-like and diffusive transport at small and large distance scales. When momentum dissipates quickly, there is no such excitation in the incoherent AC heat conductivity, and diffusion dominates at all distance scales. For a critical value of the momentum dissipation rate, we compute exact expressions for the Green's functions of our holographic system due to an emergent gravitational self-duality, similar to electric/magnetic duality, and SL(2, ) symmetries. We extend the coherent/incoherent classification to examples of charge transport in other holographic systems: probe brane theories and neutral theories with non-Maxwell actions.

Davison, Richard A.; Goutéraux, Blaise

2015-01-01

349

Turbulent Transport of Momentum and Scalars Above an Urban Canopy  

NASA Astrophysics Data System (ADS)

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.

Wang, Linlin; Li, Dan; Gao, Zhiqiu; Sun, Ting; Guo, Xiaofeng; Bou-Zeid, Elie

2014-03-01

350

Variations in atmospheric angular momentum  

NASA Technical Reports Server (NTRS)

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.

Rosen, R. D.; Salstein, D. A.

1981-01-01

351

QM Momentum Expectation Value Program  

NSDL National Science Digital Library

The QM Momentum Expectation Value program displays the time evolution of the position-space wave function and the associated momentum expectation value. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the qm_expectation_p.jar file will run the program if Java is installed. The default wave function is a Gaussian wave packet in a harmonic oscillator. Additional states and other potential energy functions can be specified using the Display | Switch GUI menu item. QM Momentum Expectation Value is one of 18 Open Source Physics programs that model time-dependent quantum mechanics using an energy eigenstate expansion. Other programs provide additional visualizations. They can be found by searching ComPADRE for Open Source Physics, OSP, or Superposition.

Christian, Wolfgang

2008-04-17

352

Transfer form  

Cancer.gov

10/02 Transfer Investigational Agent Form This form is to be used for an intra-institutional transfer, one transfer/form. Division of Cancer Prevention National Cancer Institute National Institutes of Health TRANSFER FROM: Investigator transferring agent:

353

The Physics Classroom: Momentum and Its Conservation  

NSDL National Science Digital Library

This web site contains a number of tutorials relating to momentum. Each tutorial explains a subject and provides exercises to test the user's understanding. Some are accompanied by images, animations or graphs to illustrate the concepts. Among the subjects are momentum, momentum and impulse connections, conservation of momentum and collisions.

Henderson, Tom

2005-03-16

354

Spin Angular Momentum Imparted by Gravitational Waves  

E-print Network

Following the demonstration that gravitational waves impart linear momentum, it is argued that if they are polarized they should impart angular momentum to appropriately placed 'test rods' in their path. A general formula for this angular momentum is obtained and used to provide expressions for the angular momentum imparted by plane and cylindrical gravitational waves.

M Sharif

2007-01-23

355

Induction and Persistence of Large ?H2AX Foci by High Linear Energy Transfer Radiation in DNA-Dependent protein kinase–Deficient Cells  

SciTech Connect

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.

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

356

Observations of Anomalous Momentum Transport in Alcator C-Mod Plasmas with No Momentum Input  

NASA Astrophysics Data System (ADS)

Anomalous momentum transport has been observed in Alcator C-Mod tokamak plasmas. The time evolution of core impurity toroidal rotation velocity profiles has been measured with a tangentially viewing crystal x-ray spectrometer array. Following the L-mode to EDA (enhanced D_?) H-mode transition in both Ohmic and ICRF heated discharges, the ensuing co-current toroidal rotation velocity, which is generated in the absence of any external momentum source, is observed to propagate in from the edge plasma to the core with a time scale of order of the observed energy confinement time, but much less than the neo-classical momentum confinement time. The ensuing steady state toroidal rotation velocity profiles in EDA H-mode plasmas are relatively flat, with V_? ˜ 50 km/s, and the momentum transport can be simulated with a simple diffusion model. Assuming the L-H transition produces an instantaneous edge source of toroidal torque (which disappears at the H- to L-mode transition), the momentum transport may be characterized by a diffusivity, with values of ˜ 0.07 m^2/s during EDA H-mode and ˜ 0.2 m^2/s in L-mode. These values are large compared to the calculated neo-classical momentum diffusivities. Profiles during ELM-free H-mode plasmas are centrally peaked (with V_?(0) exceeding 100 km/s in some cases), which suggests the workings of inward momentum convection; the observed profiles are matched with simulations including an inward convection velocity of ˜ 10 m/s. In EDA H-mode discharges which develop internal transport barriers, the velocity profiles become hollow in the center, indicating the presence of a negative radial electric field well in the vicinity of the barrier foot. Upper single null diverted L-mode plasmas and inner wall limited discharges exhibit strong counter-current rotation (with V_?(0) ˜ -60 km/s in some cases), which may be related to the observed higher H-mode power threshold in these configurations. For plasmas with locked modes, the toroidal rotation is observed to stop (V_??5 km/s).

Rice, John

2003-10-01

357

Observations of anomalous momentum transport in Alcator C-Mod plasmas with no momentum input  

NASA Astrophysics Data System (ADS)

Anomalous momentum transport has been observed in Alcator C-Mod tokamak plasmas. The time evolution of core impurity toroidal rotation velocity profiles has been measured with a tangentially viewing crystal x-ray spectrometer array. Following the L-mode to EDA (enhanced Dagr) H-mode transition in both Ohmic and ion cyclotron range of frequencies heated discharges, the ensuing co-current toroidal rotation velocity, which is generated in the absence of any external momentum source, is observed to propagate in from the edge plasma to the core with a timescale of the order of the observed energy confinement time, but much less than the neo-classical momentum confinement time. The ensuing steady state toroidal rotation velocity profiles in EDA H-mode plasmas are relatively flat, with Vphgr ~ 50 km s-1, and the momentum transport can be simulated using a simple diffusion model. Assuming that the L-H transition produces an instantaneous edge source of toroidal torque (which disappears at the H- to L-mode transition), the momentum transport may be characterized by a diffusivity, with values of ~0.07 m2 s-1 during EDA H-mode and ~0.2 m2 s-1 in L-mode. These values are large compared to the calculated neo-classical momentum diffusivities, which are of the order of 0.003 m2 s-1. Velocity profiles of ELM-free H-mode plasmas are centrally peaked (with Vphgr(0) exceeding 100 km s-1 in some cases), which suggests the presence of an inward momentum pinch; the observed profiles are consistent with simulations including an edge inward convection velocity of ~10 m s-1. In EDA H-mode discharges which develop internal transport barriers, the velocity profiles become hollow in the centre, indicating the presence of a negative radial electric field well in the vicinity of the barrier foot. Upper single null diverted and inner wall limited L-mode discharges exhibit strong counter-current rotation (with Vphgr(0)~-60 km s-1 in some cases), which may be related to the observed higher H-mode power threshold in these configurations. For plasmas with locked modes, the toroidal rotation is observed to cease (Vphgr les 5 km s-1).

Rice, J. E.; Lee, W. D.; Marmar, E. S.; Bonoli, P. T.; Granetz, R. S.; Greenwald, M. J.; Hubbard, A. E.; Hutchinson, I. H.; Irby, J. H.; Lin, Y.; Mossessian, D.; Snipes, J. A.; Wolfe, S. M.; Wukitch, S. J.

2004-03-01

358

The form factors of the nucleon at small momentum transfer  

E-print Network

We study the low energy expansion of the nucleon's electroweak form factors in the framework of an effective chiral Lagrangian including pions, nucleons and the $Delta (1232)$. We work to third order in the so-called small scale expansion and compare the results with the ones previously obtained in the chiral expansion. In addition, these calculations serve as a first exploratory study of renormalization and decoupling within the small scale expansion.

Véronique Bernard; Harold W. Fearing; Thomas R. Hemmert; Ulf-G. Meißner

1998-04-28

359

High Speed Photography And Momentum Transfer Of Low Strength Projectiles  

NASA Astrophysics Data System (ADS)

Aerial targets for site-defense weapons, such as rapid fire guns, must be designed so that impact loads are as benign as possible. Otherwise, the target site (a ship, for example) is placed in jeopardy if the weapon fails to perform properly.

Hanchak, S. J.; Bless, S. J.; Paisley, D. L.

1984-11-01

360

Transparency in hadronic reactions at high momentum transfers  

SciTech Connect

In this article, experimental results about color transparency of hadrons in nuclei will be briefly reviewed. The current progress of a new experiment, EVA, will also be reported. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Wu, J.; Durrant, S.; Minor, E.; Heppelmann, S. [Pennsylvania State University, Pennsylvania (United States); Barton, D.; Bunce, G.; Carroll, A.; Gushue, S.; Kaye, S.; Kmit, M.; Makdisi, Y.; Martel, D.; Roser, T.; Tanaka, M. [Brookhaven National Laboratory (United States); Christensen, N.; Courant, H.; Marshak, M.; Maxam, D.; White, C. [University of Minnesota, Minnesota (United States); Baker, S.; Barbosa, F.; Russell, J. [University of Massachusetts, Dartmouth, Massachusetts (United States); Nicholson, H. [Mt, Holyoke College (United States); Aclander, H.; Alster, J.; Mardor, I.; Mardor, Y.; Piasetzky, E. [Tel Aviv University (Israel)

1995-07-10

361

Momentum Transfer by Laser Ablation of Irregularly Shaped Space Debris  

SciTech Connect

Proposals for ground-based laser remediation of space debris rely on the creation of appropriately directed ablation-driven impulses to either divert the fragment or drive it into an orbit with a perigee allowing atmospheric capture. For a spherical fragment, the ablation impulse is a function of the orbital parameters and the laser engagement angle. If, however, the target is irregularly shaped and arbitrarily oriented, new impulse effects come into play. Here we present an analysis of some of these effects.

Liedahl, D A; Libby, S B; Rubenchik, A

2010-02-04

362

The Angular Momentum of Baryons and Dark Matter Halos Revisited  

NASA Technical Reports Server (NTRS)

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.

Kimm, Taysun; Devriendt, Julien; Slyz, Adrianne; Pichon, Christophe; Kassin, Susan A.; Dubois, Yohan

2011-01-01

363

Representational Momentum in Older Adults  

ERIC Educational Resources Information Center

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…

Piotrowski, Andrea S.; Jakobson, Lorna S.

2011-01-01

364

Angular momentum in human walking  

Microsoft Academic Search

SUMMARY Angular momentum is a conserved physical quantity for isolated systems where no external moments act about a body?s center of mass (CM). However, in the case of legged locomotion, where the body interacts with the environment (ground reaction forces), there is no a priori reason for this relationship to hold. A key hypothesis in this paper is that angular

Hugh Herr; Marko Popovic

2008-01-01

365

Teaching about Impulse and Momentum  

ERIC Educational Resources Information Center

This American Association of Physics Teachers/Physics Teaching Resource Agents (APPT/PTRA) spiral-bound manual features labs and demos physics teachers can use to give students hands-on opportunities to learn about impulse and momentum. "Make-and-take activities" include AAPT Apparatus Contest winners "An Air Impulse Rocket," "A Fan Driven…

Franklin, Bill

2004-01-01

366

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)

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.

Eckert, E R G; Diaguila, A J

1952-01-01

367

Di-jet asymmetric momentum transported by QGP fluid  

E-print Network

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 $\\left(3+1\\right)$-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.

Tachibana, Yasuki

2014-01-01

368

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)

Local heat transfer coefficients were experimentally mapped along the midchord of a five-time-size turbine blade airfoil in a static cascade operated at room temperature over a range of Reynolds numbers. The test surface consisted of a composite of commercially available materials: a mylar sheet with a layer of cholesteric liquid crystals, that change color with temperature, and a heater sheet made of a carbon-impregnated paper, that produces uniform heat flux. After the initial selection and calibration of the composite sheet, accurate, quantitative, and continuous heat transfer coefficients were mapped over the airfoil surface. The local heat transfer coefficients are presented for Reynolds numbers from 2.8 x 10 to the 5th power to 7.6 x 10 to the 5th power. Comparisons are made with analytical values of heat transfer coefficients obtained from the STAN5 boundary layer code. Also, a leading edge separation bubble was revealed by thermal and flow visualization.

Hippensteele, S. A.; Russell, L. M.; Torres, F. J.

1985-01-01

369

Dogs leaving the ICU carry a very large multi-drug resistant enterococcal population with capacity for biofilm formation and horizontal gene transfer.  

PubMed

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±0.8×10(8) 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

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

2011-01-01

370

Spacetimes with Semisymmetric Energy-Momentum Tensor  

NASA Astrophysics Data System (ADS)

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.

De, U. C.; Velimirovi?, Ljubica

2014-10-01

371

Transverse momentum distributions of jets and weak bosons  

SciTech Connect

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.

Ellis, R.K.

1984-05-01

372

Axions and the galactic angular momentum distribution  

NASA Astrophysics Data System (ADS)

We analyze the behavior of axion dark matter before it falls into a galactic gravitational potential well. The axions thermalize sufficiently fast by gravitational self-interactions that almost all go to their lowest-energy state consistent with the total angular momentum acquired from tidal torquing. That state is a state of rigid rotation on the turnaround sphere. It predicts the occurrence and detailed properties of the caustic rings of dark matter for which observational evidence had been found earlier. We show that the vortices in the axion Bose-Einstein condensate (BEC) are attractive, unlike those in superfluid He4 and dilute gases. We expect that a large fraction of the vortices in the axion BEC join into a single big vortex along the rotation axis of the galaxy. The resulting enhancement of caustic rings explains the typical size of the rises in the Milky Way rotation curve attributed to caustic rings. We show that baryons and ordinary cold dark matter particles are entrained by the axion BEC and acquire the same velocity distribution. The resulting baryonic angular momentum distribution gives a good qualitative fit to the distributions observed in dwarf galaxies. We give estimates of the minimum fraction of dark matter that is composed of axions.

Banik, N.; Sikivie, P.

2013-12-01

373

A Simple Holographic Superconductor with Momentum Relaxation  

E-print Network

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 $\\mu=0$.

Keun-Young Kim; Kyung Kiu Kim; Miok Park

2015-01-14

374

A Simple Holographic Superconductor with Momentum Relaxation  

E-print Network

We study a holographic superconductor model with momentum relaxation due to massless scalar fields linear to spatial coordinates($\\psi_I = \\beta \\delta_{Ii} x^i$), where $\\beta$ is the strength of momentum relaxation. In addition to the original superconductor induced by the chemical potential($\\mu$) at $\\beta=0$, there exists a new type of superconductor induced by $\\beta$ even at $\\mu=0$. It may imply a new `pairing' mechanism of particles and antiparticles interacting with $\\beta$, which may be interpreted as `impurity'. Two parameters $\\mu$ and $\\beta$ compete in forming superconducting phase. As a result, the critical temperature behaves differently depending on $\\beta/\\mu$. It decreases when $\\beta/\\mu$ is small and increases when $\\beta/\\mu$ is large, which is a novel feature compared to other models. After analysing ground states and phase diagrams for various $\\beta/\\mu$, we study optical electric($\\sigma$), thermoelectric($\\alpha$), and thermal($\\bar{\\kappa}$) conductivities. When the system undergo...

Kim, Keun-Young; Park, Miok

2015-01-01

375

Achromatic orbital angular momentum generator  

NASA Astrophysics Data System (ADS)

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.

Bouchard, Frédéric; Mand, Harjaspreet; Mirhosseini, Mohammad; Karimi, Ebrahim; Boyd, Robert W.

2014-12-01

376

Energy and Momentum Conceptual Survey  

NSDL National Science Digital Library

The Energy and Momentum Conceptual Survey is a 25-question research-based multiple-choice test designed for students in algebra- and calculus-based introductory classes. The survey is based on investigations of studentsâ difficulties in momentum and energy and should be administered in a 50-minute period. Statistical results have shown the survey to be reliable and valid. A summary of the construction and analysis of the survey is available in C. Singh and D. Rosengrant, Multiple-choice test of energy and momentum concepts, Am. J. Phys. 71 (6), 607-619 (2003). This assessment is free for use by instructors in their classroom. However, as it takes years of development effort to create and validate reliable assessment instruments, the file is password-protected. Furthermore, the author requests that 1. students are not given copies following examination; and 2. none of the questions are incorporated into web-based question delivery systems without adequate security to prevent printing or unauthorized access by students. To obtain the password, please send a request with your name, email, institution, and a link to a page at your institution that confirms you are an instructor.

Rosengrant, David; Singh, Chandralekha

2012-04-27

377

Förster-Induced Energy Transfer in Functionalized Graphene  

PubMed Central

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

2014-01-01

378

Förster-Induced Energy Transfer in Functionalized Graphene.  

PubMed

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

Malic, Ermin; Appel, Heiko; Hofmann, Oliver T; Rubio, Angel

2014-05-01

379

Angular Momentum and Galaxy Formation Revisited  

NASA Astrophysics Data System (ADS)

Motivated by a new wave of kinematical tracers in the outer regions of early-type galaxies (ellipticals and lenticulars), we re-examine the role of angular momentum in galaxies of all types. We present new methods for quantifying the specific angular momentum j, focusing mainly on the more challenging case of early-type galaxies, in order to derive firm empirical relations between stellar j sstarf and mass M sstarf (thus extending earlier work by Fall). We carry out detailed analyses of eight galaxies with kinematical data extending as far out as 10 effective radii, and find that data at two effective radii are generally sufficient to estimate total j sstarf reliably. Our results contravene suggestions that ellipticals could harbor large reservoirs of hidden j sstarf in their outer regions owing to angular momentum transport in major mergers. We then carry out a comprehensive analysis of extended kinematic data from the literature for a sample of ~100 nearby bright galaxies of all types, placing them on a diagram of j sstarf versus M sstarf. The ellipticals and spirals form two parallel j sstarf-M sstarf tracks, with log-slopes of ~0.6, which for the spirals are closely related to the Tully-Fisher relation, but for the ellipticals derives from a remarkable conspiracy between masses, sizes, and rotation velocities. The ellipticals contain less angular momentum on average than spirals of equal mass, with the quantitative disparity depending on the adopted K-band stellar mass-to-light ratios of the galaxies: it is a factor of ~3-4 if mass-to-light ratio variations are neglected for simplicity, and ~7 if they are included. We decompose the spirals into disks and bulges and find that these subcomponents follow j sstarf-M sstarf trends similar to the overall ones for spirals and ellipticals. The lenticulars have an intermediate trend, and we propose that the morphological types of galaxies reflect disk and bulge subcomponents that follow separate, fundamental j sstarf-M sstarf scaling relations. This provides a physical motivation for characterizing galaxies most basically with two parameters: mass and bulge-to-disk ratio. Next, in an approach complementary to numerical simulations, we construct idealized models of angular momentum content in a cosmological context, using estimates of dark matter halo spin and mass from theoretical and empirical studies. We find that the width of the halo spin distribution cannot account for the differences between spiral and elliptical j sstarf, but that the observations are reproduced well if these galaxies simply retained different fractions of their initial j complement (~60% and ~10%, respectively). We consider various physical mechanisms for the simultaneous evolution of j sstarf and M sstarf (including outflows, stripping, collapse bias, and merging), emphasizing that the vector sum of all such processes must produce the observed j sstarf-M sstarf relations. We suggest that a combination of early collapse and multiple mergers (major or minor) may account naturally for the trend for ellipticals. More generally, the observed variations in angular momentum represent simple but fundamental constraints for any model of galaxy formation.

Romanowsky, Aaron J.; Fall, S. Michael

2012-12-01

380

Controlling matter waves in momentum space  

NASA Astrophysics Data System (ADS)

The transformation design method of momentum for matter waves in a harmonic trap is proposed. As applications, we design (1) a momentum invisibility cloak to control the distribution of a wave function in momentum space, (2) a quantum localization cloak that localizes a matter wave around zero momentum, and (3) the unusual quantum states of momentum space. Comprehension of these momentum cloaks in position space through the Fourier transformation is presented. In contrast to the construct of quantum cloaks in position space, the momentum cloaks presented here can only be reached by controlling the spring parameter of the trap and offering a potential there, without needing to control the effective mass of quantum particles themselves. The presented discussions also provide a possible inspiration to help localize and maintain a quantum state in momentum space by way of controlling the shape of a trap and a supplied potential.

Lin, De-Hone

2014-07-01

381

Energy and Momentum Transport in String Waves  

ERIC Educational Resources Information Center

Formulas are derived for the energy, momentum, and angular momentum transmitted by waves of arbitrary shape in an inextensible string by pure transverse waves in a string using Tait's procedure. (Author/CP)

Juenker, D. W.

1976-01-01

382

Heat transfer in rectangular microchannels  

Microsoft Academic Search

Convection heat transfer in a rectangular microchannel is investigated. The flow is assumed to be fully developed both thermally and hydrodynamically. The H2-type boundary condition, constant axial and peripheral heat flux, is applied at the walls of the channel. Since the velocity profile for a rectangular channel is not known under the slip flow conditions, the momentum equation is first

Gokturk Tunc; Yildiz Bayazitoglu

2002-01-01

383

Moments of nuclear and nucleon structure functions at low Q^2 and the momentum sum rule  

E-print Network

New nuclear structure function data from Jefferson Lab covering the higher x and lower Q^2 regime make it possible to extract the higher order F_2 moments for iron and deuterium at low four-momentum transfer squared Q^2. These moments allow for an experimental investigation of the nuclear momentum sum rule and a direct comparison of the non-singlet nucleon moment with Lattice QCD results.

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

2005-09-22

384

Electric Field in a Double Layer and the Imparted Momentum  

SciTech Connect

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.

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

2006-02-17

385

Electric field in a double layer and the imparted momentum.  

PubMed

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

Fruchtman, A

2006-02-17

386

Light angular momentum of a plane wave diffracted by a two-dimensional object  

NASA Astrophysics Data System (ADS)

The question of the transfer of angular momentum from light to objects is a key issue in optical tweezers and thus raises issues in physics, chemistry, and biology. Most of the attempts have been performed either with spin angular momentum using light's polarization or using orbital angular momentum with twisted beams. We experimentally demonstrate here the exchange of angular momentum from a linearly polarized plane wave to a two dimensional asymmetric object. More precisely, we show that the diffracted light from a snail-shaped mask carries local orbital angular momentum whose topological charge depends on the symmetry of the object. This opens the way to a means to produce micrometer-sized twisted beams from a high power laser or even pulsed beams.

Emile, Olivier; Le Meur, Morgane; Emile, Janine

2014-01-01

387

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

E-print Network

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

Nolan, David S.

388

Hadronic momentum densities in the transverse plane  

Microsoft Academic Search

We examine the spatial density within extended objects of the momentum component p+, and find relativistically exact connections to Fourier transforms of gravitational form factors. We apply these results to obtain semiempirical momentum density distributions within nucleons, and similar distributions for spin-1 objects based on theoretical results from the AdS\\/QCD correspondence. We find that the momentum density in the transverse

Zainul Abidin; Carl E. Carlson

2008-01-01

389

The angular momentum of the Oort cloud  

Microsoft Academic Search

An evaluation is made of the work of Marochnik et al. (1988), which estimated that the angular momentum of the Oort cloud is 2-3 orders of magnitude greater than the planetary system's total angular momentum. It is noted that most of the angular momentum in the currently observed Oort cloud is the result of the effects of external perturbers over

P Weissman

1991-01-01

390

Physics 321 Linear Momentum and Its Conservation  

E-print Network

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

Hart, Gus

391

FLEXIBLE SPACECRAFT REORIENTATIONS USING GIMBALED MOMENTUM WHEELS  

E-print Network

FLEXIBLE SPACECRAFT REORIENTATIONS USING GIMBALED MOMENTUM WHEELS Kevin A. Fordy and Christopher D concise form of the equations of motion for a spacecraft with gimbaled momentum wheels and exible) or control moment gyros ( xed spin speed). The gimbaled momentum wheel (GMW) is simply a combination

Hall, Christopher D.

392

Distributed control using linear momentum exchange devices  

NASA Technical Reports Server (NTRS)

MSFC has successfully employed the use of the Vibrational Control of Space Structures (VCOSS) Linear Momentum Exchange Devices (LMEDs), which was an outgrowth of the Air Force Wright Aeronautical Laboratory (AFWAL) program, in a distributed control experiment. The control experiment was conducted in MSFC's Ground Facility for Large Space Structures Control Verification (GF/LSSCV). The GF/LSSCV's test article was well suited for this experiment in that the LMED could be judiciously placed on the ASTROMAST. The LMED placements were such that vibrational mode information could be extracted from the accelerometers on the LMED. The LMED accelerometer information was processed by the control algorithms so that the LMED masses could be accelerated to produce forces which would dampen the vibrational modes of interest. Experimental results are presented showing the LMED's capabilities.

Sharkey, J. P.; Waites, Henry; Doane, G. B., III

1987-01-01

393

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

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…

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

394

Heat transfer in pipes  

NASA Technical Reports Server (NTRS)

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.

Burbach, T.

1985-01-01

395

Antiproton momentum distributions as a measure of electron cooling force at the Fermilab Recycler  

SciTech Connect

The Fermilab Recycler is a fixed 8 GeV kinetic energy storage ring located in the Fermilab Main Injector tunnel near the ceiling. Electron cooling of high energy antiprotons has recently been demosntrated [1] at the Recycler. Antiproton beam Schottky signals were used to measure the antiproton momentum distribution at equilibrium between a calibrated broadband diffusion source and electron cooling. The large Recycler momentum aperture, the dependence of the electron cooling force as a function of the antiproton momentum deviation and the calibrated diffusion source combine to give a unique sepectral measurement of the antiproton beam momentum distribution.

Broemmelsiek, D.R.; Nagaitsev, S.; /Fermilab

2006-06-01

396

Angular momentum desaturation for Skylab using gravity gradient torques  

NASA Technical Reports Server (NTRS)

An angular momentum desaturation method for momentum exchange devices of orbiting spacecraft is described. The specific application of the method is to the Skylab which contains three double-gimbaled control moment gyros for precise attitude control and maneuvering. It is assumed that the attitude reference is inertially fixed and that two of the vehicle principal moments of inertia are much larger than the third. Gravity gradient torques and resultant angular momentum accumulation are developed for small deviations from the reference. The assumed moment-of-inertia distribution allows desaturation about all axes with only two attitude angles each for the two axes with large moments of inertia. The necessary desaturation maneuvers can be decoupled for a special set of orbital coordinates. All maneuvers are made during the night portion of the orbit, and the percentage utilized for desaturation is selectable. Expressions for the attitude angle commands are developed assuming infinite vehicle rates. The effect of finite rates introduces an efficiency into the desaturation. Expressions for this efficiency are developed and means for compensation are treated. Arbitrary misalignments between geometric vehicle axes and principal moment-of-inertia axes are permissible. An angle bias about the sun line minimizes the angular momentum accumulation about the sun line projection into the orbital plane. Adaptive desaturation maneuver limiting consistent with the available maneuver momentum is included.

Kennel, H. F.

1971-01-01

397

Noise-immune conjugate large-area atom interferometers.  

PubMed

We present a pair of simultaneous conjugate Ramsey-Bordé atom interferometers using large (20variant Planck's over 2pik)-momentum transfer beam splitters, where variant Planck's over 2pik 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 20variant Planck's over 2pik by a factor of 2500. Using a splitting of 10variant Planck's over 2pik, 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. PMID:19792468

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

2009-07-31

398

Cotton buds, momentum, and impulse  

NASA Astrophysics Data System (ADS)

Here is a simple experiment demonstrating impulse and momentum that was picked up from a Japanese presenter at a physics teacher conference held in Cebu City. We have not been able to trace the experiment farther and have never seen it in print. After student-author Nuñez demonstrated it during an exam on conducting demonstrations, we converted the qualitative idea into a quanitative experiment and even discovered some possibilities for student research. The lab is also suitable as homework, since it uses universally available "equipment" — cotton buds (swabs), drinking straws, and a ruler.

van den Berg, Ed; Nuñez, Jover; Guirit, Alfredo; van Huis, Cor

2000-01-01

399

Workshop on momentum distributions: Summary  

SciTech Connect

This has been an extraordinary Workshop touching many branches of physics. The Workshop has treated momentum distributions in fluid and solid condensed matter, in nuclei, and in electronic systems. Both theoretical and experimental concepts and methods have been considered in all these branches. A variety of specific illustrations and applications in physical systems have been presented. One finds that some common unifying themes emerge. One finds, also, that some examples are available to illustrate where one branch is more mature than others and to contrast where expectations for future progress may be most encouraged. 6 refs., 2 figs.

Simmons, R.O.

1988-01-01

400

Coherent Stern-Gerlach momentum splitting on an atom chip.  

PubMed

In the Stern-Gerlach effect, a magnetic field gradient splits particles into spatially separated paths according to their spin projection. The idea of exploiting this effect for creating coherent momentum superpositions for matter-wave interferometry appeared shortly after its discovery, almost a century ago, but was judged to be far beyond practical reach. Here we demonstrate a viable version of this idea. Our scheme uses pulsed magnetic field gradients, generated by currents in an atom chip wire, and radio-frequency Rabi transitions between Zeeman sublevels. We transform an atomic Bose-Einstein condensate into a superposition of spatially separated propagating wavepackets and observe spatial interference fringes with a measurable phase repeatability. The method is versatile in its range of momentum transfer and the different available splitting geometries. These features make our method a good candidate for supporting a variety of future applications and fundamental studies. PMID:24013518

Machluf, Shimon; Japha, Yonathan; Folman, Ron

2013-01-01

401

Dynamics of quantum liquids at high momentum  

NASA Astrophysics Data System (ADS)

The dynamic form factor S(Q,?) in liquid 3He and 4He is evaluated in the wave-vector transfer range 3<=Q<=15 Å-1. The input is the pair