Digitala Vetenskapliga Arkivet

Change search
Refine search result
1234567 1 - 50 of 4987
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Aad, G
    et al.
    Jovicevic, Jelena
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Kuwertz, Emma
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Lund-Jensen, Bengt
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Morley, Anthony
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Strandberg, Jonas
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Zwalinski, L.
    et al.,
    Measurement of differential production cross-sections for a Z boson in association with b-jets in 7 TeV proton-proton collisions with the ATLAS detector2014In: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, no 10, p. 141-Article in journal (Refereed)
    Abstract [en]

    Measurements of differential production cross-sections of a Z boson in association with b-jets in pp collisions at root s = 7 TeV are reported. The data analysed correspond to an integrated luminosity of 4.6 fb(-1) recorded with the ATLAS detector at the Large Hadron Collider. Particle-level cross-sections are determined for events with a Z boson decaying into an electron or muon pair, and containing b-jets. For events with at least one b-jet, the cross-section is presented as a function of the Z boson transverse momentum and rapidity, together with the inclusive b-jet cross-section as a function of b-jet transverse momentum, rapidity and angular separations between the b-jet and the Z boson. For events with at least two b-jets, the cross-section is determined as a function of the invariant mass and angular separation of the two highest transverse momentum b-jets, and as a function of the Z boson transverse momentum and rapidity. Results are compared to leading-order and next-to-leading-order perturbative QCD calculations.

  • 2. Aad, G
    et al.
    Jovicevic, Jelena
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Kuwertz, Emma
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Lund-Jensen, Bengt
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Morley, Anthony
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Strandberg, Jonas
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Zwalinski, L.
    et al.,
    Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at TeV with ATLAS2014In: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, no 9, p. 1-61Article in journal (Refereed)
    Abstract [en]

    Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of TeV. The analysis is performed in the H -> gamma gamma decay channel using 20.3 fb(-1) of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp -> H -> gamma gamma fiducial cross section is measured to be 43.2 +/- 9.4(stat.) (-aEuro parts per thousand 2.9) (+ 3.2) (syst.) +/- 1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations.

  • 3. Aad, G
    et al.
    Jovicevic, Jelena
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Kuwertz, Emma
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Morley, Anthony
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Strandberg, Jonas
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Zwalinski, L.
    et al.,
    Search for Scalar Diphoton Resonances in the Mass Range 65-600 GeV with the ATLAS Detector in pp Collision Data at root s=8 TeV2014In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 113, no 17Article in journal (Refereed)
    Abstract [en]

    A search for scalar particles decaying via narrow resonances into two photons in the mass range 65-600 GeV is performed using 20.3 fb(-1) of root s = 8 TeV pp collision data collected with the ATLAS detector at the Large Hadron Collider. The recently discovered Higgs boson is treated as a background. No significant evidence for an additional signal is observed. The results are presented as limits at the 95% confidence level on the production cross section of a scalar boson times branching ratio into two photons, in a fiducial volume where the reconstruction efficiency is approximately independent of the event topology. The upper limits set extend over a considerably wider mass range than previous searches.

  • 4. Aartsen, M. G.
    et al.
    Ackermann, M.
    Adams, J.
    Aguilar, J. A.
    Ahlers, M.
    Ahrens, M.
    Altmann, D.
    Anderson, T.
    Arguelles, C.
    Arlen, T. C.
    Auffenberg, J.
    Bai, X.
    Barwick, S. W.
    Baum, V.
    Bay, R.
    Beatty, J. J.
    Tjus, J. Becker
    Becker, K. -H
    BenZvi, S.
    Berghaus, P.
    Berley, D.
    Bernardini, E.
    Bernhard, A.
    Besson, D. Z.
    Binder, G.
    Bindig, D.
    Bissok, M.
    Blaufuss, E.
    Blumenthal, J.
    Boersma, David J.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Bohm, C.
    Bos, F.
    Bose, D.
    Boeser, S.
    Botner, Olga
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Brayeur, L.
    Bretz, H. -P
    Brown, A. M.
    Buzinsky, N.
    Casey, J.
    Casier, M.
    Cheung, E.
    Chirkin, D.
    Christov, A.
    Christy, B.
    Clark, K.
    Classen, L.
    Clevermann, F.
    Coenders, S.
    Cowen, D. F.
    Silva, A. H. Cruz
    Danninger, M.
    Daughhetee, J.
    Davis, J. C.
    Day, M.
    De Andre, J. P. A. M.
    De Clercq, C.
    De Ridder, S.
    Desiati, P.
    De Vries, K. D.
    De With, M.
    DeYoung, T.
    Diaz-Velez, J. C.
    Dunkman, M.
    Eagan, R.
    Eberhardt, B.
    Eichmann, B.
    Eisch, J.
    Euler, Sebastian
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Evenson, P. A.
    Fadiran, O.
    Fazely, A. R.
    Fedynitch, A.
    Feintzeig, J.
    Felde, J.
    Feusels, T.
    Filimonov, K.
    Finley, C.
    Fischer-Wasels, T.
    Flis, S.
    Franckowiak, A.
    Frantzen, K.
    Fuchs, T.
    Gaisser, T. K.
    Gaior, R.
    Gallagher, J.
    Gerhardt, L.
    Gier, D.
    Gladstone, L.
    Gluesenkamp, T.
    Goldschmidt, A.
    Golup, G.
    Gonzalez, J. G.
    Goodman, J. A.
    Gora, D.
    Grant, D.
    Gretskov, P.
    Groh, J. C.
    Gross, A.
    Ha, C.
    Haack, C.
    Ismail, A. Haj
    Hallen, P.
    Hallgren, Allan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Halzen, F.
    Hanson, K.
    Hebecker, D.
    Heereman, D.
    Heinen, D.
    Helbing, K.
    Hellauer, R.
    Hellwig, D.
    Hickford, S.
    Hill, G. C.
    Hoffman, K. D.
    Hoffmann, R.
    Homeier, A.
    Hoshina, K.
    Huang, F.
    Huelsnitz, W.
    Hulth, P. O.
    Hultqvist, K.
    Hussain, S.
    Ishihara, A.
    Jacobi, E.
    Jacobsen, J.
    Jagielski, K.
    Japaridze, G. S.
    Jero, K.
    Jlelati, O.
    Jurkovic, M.
    Kaminsky, B.
    Kappes, A.
    Karg, T.
    Karle, A.
    Kauer, M.
    Keivani, A.
    Kelley, J. L.
    Kheirandish, A.
    Kiryluk, J.
    Klaes, J.
    Klein, S. R.
    Koehne, J. -H
    Kohnen, G.
    Kolanoski, H.
    Koob, A.
    Koepke, L.
    Kopper, C.
    Kopper, S.
    Koskinen, D. J.
    Kowalski, M.
    Kriesten, A.
    Krings, K.
    Kroll, G.
    Kroll, M.
    Kunnen, J.
    Kurahashi, N.
    Kuwabara, T.
    Labare, M.
    Larsen, D. T.
    Larson, M. J.
    Lesiak-Bzdak, M.
    Leuermann, M.
    Leute, J.
    Luenemann, J.
    Madsen, J.
    Maggi, G.
    Maruyama, R.
    Mase, K.
    Matis, H. S.
    Maunu, R.
    McNally, F.
    Meagher, K.
    Medici, M.
    Meli, A.
    Meures, T.
    Miarecki, S.
    Middell, E.
    Middlemas, E.
    Milke, N.
    Miller, J.
    Mohrmann, L.
    Montaruli, T.
    Morse, R.
    Nahnhauer, R.
    Naumann, U.
    Niederhausen, H.
    Nowicki, S. C.
    Nygren, D. R.
    Obertacke, A.
    Odrowski, S.
    Olivas, A.
    Omairat, A.
    O'Murchadha, A.
    Palczewski, T.
    Paul, L.
    Penek, OE.
    Pepper, J. A.
    Heros, Carlos Perez de los
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Pfendner, C.
    Pieloth, D.
    Pinat, E.
    Posselt, J.
    Price, P. B.
    Przybylski, G. T.
    Puetz, J.
    Quinnan, M.
    Raedel, L.
    Rameez, M.
    Rawlins, K.
    Redl, P.
    Rees, I.
    Reimann, R.
    Relich, M.
    Resconi, E.
    Rhode, W.
    Richman, M.
    Riedel, B.
    Robertson, S.
    Rodrigues, J. P.
    Rongen, M.
    Rott, C.
    Ruhe, T.
    Ruzybayev, B.
    Ryckbosch, D.
    Saba, S. M.
    Sander, H. -G
    Sandroos, J.
    Santander, M.
    Sarkar, S.
    Schatto, K.
    Scheriau, F.
    Schmidt, T.
    Schmitz, M.
    Schoenen, S.
    Schoeneberg, S.
    Schoenwald, A.
    Schukraft, A.
    Schulte, L.
    Schulz, O.
    Seckel, D.
    Sestayo, Y.
    Seunarine, S.
    Shanidze, R.
    Smith, M. W. E.
    Soldin, D.
    Spiczak, G. M.
    Spiering, C.
    Stamatikos, M.
    Stanev, T.
    Stanisha, N. A.
    Stasik, A.
    Stezelberger, T.
    Stokstad, R. G.
    Stoessl, A.
    Strahler, E. A.
    Ström, Rickard
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Strotjohann, N. L.
    Sullivan, G. W.
    Taavola, Henric
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Taboada, I.
    Tamburro, A.
    Tepe, A.
    Ter-Antonyan, S.
    Terliuk, A.
    Tesic, G.
    Tilav, S.
    Toale, P. A.
    Tobin, M. N.
    Tosi, D.
    Tselengidou, M.
    Unger, Elisabeth
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Usner, M.
    Vallecorsa, S.
    van Eijndhoven, N.
    Vandenbroucke, J.
    van Santen, J.
    Vehring, M.
    Voge, M.
    Vraeghe, M.
    Walck, C.
    Wallraff, M.
    Weaver, Ch.
    Wellons, M.
    Wendt, C.
    Westerhoff, S.
    Whelan, B. J.
    Whitehorn, N.
    Wichary, C.
    Wiebe, K.
    Wiebusch, C. H.
    Williams, D. R.
    Wissing, H.
    Wolf, M.
    Wood, T. R.
    Woschnagg, K.
    Xu, D. L.
    Xu, X. W.
    Yanez, J. P.
    Yodh, G.
    Yoshida, S.
    Zarzhitsky, P.
    Ziemann, J.
    Zierke, S.
    Zoll, M.
    Atmospheric and astrophysical neutrinos above 1 TeV interacting in IceCube2015In: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 91, no 2, p. 022001-Article in journal (Refereed)
    Abstract [en]

    The IceCube Neutrino Observatory was designed primarily to search for high-energy (TeV-PeV) neutLrinos produced in distant astrophysical objects. A search for. greater than or similar to 100 TeV neutrinos interacting inside the instrumented volume has recently provided evidence for an isotropic flux of such neutrinos. At lower energies, IceCube collects large numbers of neutrinos from the weak decays of mesons in cosmic-ray air showers. Here we present the results of a search for neutrino interactions inside IceCube's instrumented volume between 1 TeV and 1 PeV in 641 days of data taken from 2010-2012, lowering the energy threshold for neutrinos from the southern sky below 10 TeV for the first time, far below the threshold of the previous high-energy analysis. Astrophysical neutrinos remain the dominant component in the southern sky down to a deposited energy of 10 TeV. From these data we derive new constraints on the diffuse astrophysical neutrino spectrum, Phi(v) = 2.06(-0.3)(+0.4) x 10(-18) (E-v = 10(5) GeV)-2.46 +/- 0.12GeV-1 cm(-2) sr(-1) s(-1) for 25 TeV < E-v < 1.4 PeV, as well as the strongest upper limit yet on the flux of neutrinos from charmed-meson decay in the atmosphere, 1.52 times the benchmark theoretical prediction used in previous IceCube results at 90% confidence.

  • 5. Aartsen, M. G.
    et al.
    Ackermann, M.
    Adams, J.
    Aguilar, J. A.
    Ahlers, M.
    Ahrens, M.
    Altmann, D.
    Anderson, T.
    Arguelles, C.
    Arlen, T. C.
    Auffenberg, J.
    Bai, X.
    Barwick, S. W.
    Baum, V.
    Beatty, J. J.
    Tjus, J. Becker
    Becker, K. -H
    BenZvi, S.
    Berghaus, P.
    Berley, D.
    Bernardini, E.
    Bernhard, A.
    Besson, D. Z.
    Binder, G.
    Bindig, D.
    Bissok, M.
    Blaufuss, E.
    Blumenthal, J.
    Boersma, David J.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Bohm, C.
    Bos, F.
    Bose, D.
    Boeser, S.
    Botner, Olga
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Brayeur, L.
    Bretz, H. -P
    Brown, A. M.
    Casey, J.
    Casier, M.
    Chirkin, D.
    Christov, A.
    Christy, B.
    Clark, K.
    Classen, L.
    Clevermann, F.
    Coenders, S.
    Cowen, D. F.
    Silva, A. H. Cruz
    Danninger, M.
    Daughhetee, J.
    Davis, J. C.
    Day, M.
    de Andre, J. P. A. M.
    De Clercq, C.
    De Ridder, S.
    Desiati, P.
    de Vries, K. D.
    de With, M.
    DeYoung, T.
    Diaz-Velez, J. C.
    Dunkman, M.
    Eagan, R.
    Eberhardt, B.
    Eichmann, B.
    Eisch, J.
    Euler, Sebastian
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Evenson, P. A.
    Fadiran, O.
    Fazely, A. R.
    Fedynitch, A.
    Feintzeig, J.
    Felde, J.
    Feusels, T.
    Filimonov, K.
    Finley, C.
    Fischer-Wasels, T.
    Flis, S.
    Franckowiak, A.
    Frantzen, K.
    Fuchs, T.
    Gaisser, T. K.
    Gallagher, J.
    Gerhardt, L.
    Gier, D.
    Gladstone, L.
    Gluesenkamp, T.
    Goldschmidt, A.
    Golup, G.
    Gonzalez, J. G.
    Goodman, J. A.
    Gora, D.
    Grandmont, D. T.
    Grant, D.
    Gretskov, P.
    Groh, J. C.
    Gross, A.
    Ha, C.
    Haack, C.
    Ismail, A. Haj
    Hallen, P.
    Hallgren, Allan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Halzen, F.
    Hanson, K.
    Hebecker, D.
    Heereman, D.
    Heinen, D.
    Helbing, K.
    Hellauer, R.
    Hellwig, D.
    Hickford, S.
    Hill, G. C.
    Hoffman, K. D.
    Hoffmann, R.
    Homeier, A.
    Hoshina, K.
    Huang, F.
    Huelsnitz, W.
    Hulth, P. O.
    Hultqvist, K.
    Hussain, S.
    Ishihara, A.
    Jacobi, E.
    Jacobsen, J.
    Jagielski, K.
    Japaridze, G. S.
    Jero, K.
    Jlelati, O.
    Jurkovic, M.
    Kaminsky, B.
    Kappes, A.
    Karg, T.
    Karle, A.
    Kauer, M.
    Kelley, J. L.
    Kheirandish, A.
    Kiryluk, J.
    Klaes, J.
    Klein, S. R.
    Koehne, J. -H
    Kohnen, G.
    Kolanoski, H.
    Koob, A.
    Koepke, L.
    Kopper, C.
    Kopper, S.
    Koskinen, D. J.
    Kowalski, M.
    Kriesten, A.
    Krings, K.
    Kroll, G.
    Kroll, M.
    Kunnen, J.
    Kurahashi, N.
    Kuwabara, T.
    Labare, M.
    Larsen, D. T.
    Larson, M. J.
    Lesiak-Bzdak, M.
    Leuermann, M.
    Leute, J.
    Luenemann, J.
    Macias, O.
    Madsen, J.
    Maggi, G.
    Maruyama, R.
    Mase, K.
    Matis, H. S.
    McNally, F.
    Meagher, K.
    Medici, M.
    Meli, A.
    Meures, T.
    Miarecki, S.
    Middell, E.
    Middlemas, E.
    Milke, N.
    Miller, J.
    Mohrmann, L.
    Montaruli, T.
    Morse, R.
    Nahnhauer, R.
    Naumann, U.
    Niederhausen, H.
    Nowicki, S. C.
    Nygren, D. R.
    Obertacke, A.
    Odrowski, S.
    Olivas, A.
    Omairat, A.
    O'Murchadha, A.
    Palczewski, T.
    Paul, L.
    Penek, Oe.
    Pepper, J. A.
    Heros, Carlos Perez de los
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Pfendner, C.
    Pieloth, D.
    Pinat, E.
    Posselt, J.
    Price, P. B.
    Przybylski, G. T.
    Puetz, J.
    Quinnan, M.
    Raedel, L.
    Rameez, M.
    Rawlins, K.
    Redl, P.
    Rees, I.
    Reimann, R.
    Resconi, E.
    Rhode, W.
    Richman, M.
    Riedel, B.
    Robertson, S.
    Rodrigues, J. P.
    Rongen, M.
    Rott, C.
    Ruhe, T.
    Ruzybayev, B.
    Ryckbosch, D.
    Saba, S. M.
    Sander, H. -G
    Sandroos, J.
    Santander, M.
    Sarkar, S.
    Schatto, K.
    Scheriau, F.
    Schmidt, T.
    Schmitz, M.
    Schoenen, S.
    Schoeneberg, S.
    Schnoewald, A.
    Schukraft, A.
    Schulte, L.
    Schulz, O.
    Seckel, D.
    Sestayo, Y.
    Seunarine, S.
    Shanidze, R.
    Sheremata, C.
    Smith, M. W. E.
    Soldin, D.
    Spiczak, G. M.
    Spiering, C.
    Stamatikos, M.
    Stanev, T.
    Stanisha, N. A.
    Stasik, A.
    Stezelberger, T.
    Stokstad, R. G.
    Stoessl, A.
    Strahler, E. A.
    Ström, Rickard
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Strotjohann, N. L.
    Sullivan, G. W.
    Taavola, Henric
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Taboada, I.
    Tamburro, A.
    Tepe, A.
    Ter-Antonyan, S.
    Terliuk, A.
    Tesic, G.
    Tilav, S.
    Toale, P. A.
    Tobin, M. N.
    Tosi, D.
    Tselengidou, M.
    Unger, E.
    Usner, M.
    Vallecorsa, S.
    van Eijndhoven, N.
    Vandenbroucke, J.
    van Santen, J.
    Vehring, M.
    Voge, M.
    Vraeghe, M.
    Walck, C.
    Wallraff, M.
    Weaver, Ch.
    Wellons, M.
    Wendt, C.
    Westerhoff, S.
    Whelan, B. J.
    Whitehorn, N.
    Wichary, C.
    Wiebe, K.
    Wiebusch, C. H.
    Williams, D. R.
    Wissing, H.
    Wolf, M.
    Wood, T. R.
    Woschnagg, K.
    Xu, D. L.
    Xu, X. W.
    Yanez, J. P.
    Yodh, G.
    Yoshida, S.
    Zarzhitsky, P.
    Ziemann, J.
    Zierke, S.
    Zoll, M.
    Multipole analysis of IceCube data to search for dark matter accumulated in the Galactic halo2015In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 75, no 1, article id 20Article in journal (Refereed)
    Abstract [en]

    Dark matter which is bound in the Galactic halo might self-annihilate and produce a flux of stable final state particles, e. g. high energy neutrinos. These neutrinos can be detected with IceCube, a cubic-kilometer sized Cherenkov detector. Given IceCube's large field of view, a characteristic anisotropy of the additional neutrino flux is expected. In this paper we describe a multipole method to search for such a large-scale anisotropy in IceCube data. This method uses the expansion coefficients of a multipole expansion of neutrino arrival directions and incorporates signal-specific weights for each expansion coefficient. We apply the technique to a high-purity muon neutrino sample from the Northern Hemisphere. The final result is compatible with the null-hypothesis. As no signal was observed, we present limits on the self-annihilation cross-section averaged over the relative velocity distribution <sigma(A)v > down to 1.9x10(-23) cm(3) s(-1) for a dark matter particle mass of 700-1,000 GeV and direct annihilation into nu(nu) over bar. The resulting exclusion limits come close to exclusion limits from gamma-ray experiments, that focus on the outer Galactic halo, for high dark matter masses of a few TeV and hard annihilation channels.

    Download full text (pdf)
    fulltext
  • 6.
    Abali, Bilen Emek
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Applied Mechanics.
    Energy based methods applied in mechanics by using the extended Noether's formalism2023In: Zeitschrift für angewandte Mathematik und Mechanik, ISSN 0044-2267, E-ISSN 1521-4001, Vol. 103, no 12Article in journal (Refereed)
    Abstract [en]

    Physical systems are modeled by field equations; these are coupled, partial differential equations in space and time. Field equations are often given by balance equations and constitutive equations, where the former are axiomatically given and the latter are thermodynamically derived. This approach is useful in thermomechanics and electromagnetism, yet challenges arise once we apply it in damage mechanics for generalized continua. For deriving governing equations, an alternative method is based on a variational framework known as the extended Noether's formalism. Its formal introduction relies on mathematical concepts limiting its use in applied mechanics as a field theory. In this work, we demonstrate the power of extended Noether's formalism by using tensor algebra and usual continuum mechanics nomenclature. We demonstrate derivation of field equations in damage mechanics for generalized continua, specifically in the case of strain gradient elasticity.

    Download full text (pdf)
    fulltext
  • 7. Abat, E.
    et al.
    Grahan, Karl-Johan
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Lafaye, Remi
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Lund-Jensen, Bengt
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Zhou, N.
    et, al
    Photon reconstruction in the ATLAS Inner Detector and Liquid Argon Barrel Calorimeter at the 2004 Combined Test Beam2011In: Journal of Instrumentation, E-ISSN 1748-0221, Vol. 6Article in journal (Refereed)
    Abstract [en]

    The reconstruction of photons in the ATLAS detector is studied with data taken during the 2004 Combined Test Beam, where a full slice of the ATLAS detector was exposed to beams of particles of known energy at the CERN SPS. The results presented show significant differences in the longitudinal development of the electromagnetic shower between converted and unconverted photons as well as in the total measured energy. The potential to use the reconstructed converted photons as a means to precisely map the material of the tracker in front of the electromagnetic calorimeter is also considered. All results obtained are compared with a detailed Monte-Carlo simulation of the test-beam setup which is based on the same simulation and reconstruction tools as those used for the ATLAS detector itself.

  • 8. Abazov, V. M.
    et al.
    Abbott, B.
    Acharya, B. S.
    Adams, M.
    Adams, T.
    Agnew, J. P.
    Alexeev, G. D.
    Alkhazov, G.
    Alton, A.
    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.
    Besancon, 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.
    Borysova, M.
    Brandt, A.
    Brandt, O.
    Brock, R.
    Bross, A.
    Brown, D.
    Bu, X. B.
    Buehler, M.
    Buescher, V.
    Bunichev, V.
    Burdin, S.
    Buszello, Claus P.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Camacho-Perez, E.
    Casey, B. C. K.
    Castilla-Valdez, H.
    Caughron, S.
    Chakrabarti, S.
    Chan, K. M.
    Chandra, A.
    Chapon, E.
    Chen, G.
    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
    Cutts, D.
    Das, A.
    Davies, G.
    de Jong, S. J.
    De la Cruz-Burelo, E.
    Deliot, 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.
    Duperrin, A.
    Dutt, S.
    Eads, M.
    Edmunds, D.
    Ellison, J.
    Elvira, V. D.
    Enari, Y.
    Evans, H.
    Evdokimov, V. N.
    Faure, A.
    Feng, L.
    Ferbel, T.
    Fiedler, F.
    Filthaut, F.
    Fisher, W.
    Fisk, H. E.
    Fortner, M.
    Fox, H.
    Fuess, S.
    Garbincius, P. H.
    Garcia-Bellido, A.
    Garcia-Gonzalez, J. A.
    Gavrilov, V.
    Geng, W.
    Gerber, C. E.
    Gershtein, Y.
    Ginther, G.
    Gogota, O.
    Golovanov, G.
    Grannis, P. D.
    Greder, S.
    Greenlee, H.
    Grenier, G.
    Gris, Ph.
    Grivaz, J. -F
    Grohsjean, A.
    Gruenendahl, S.
    Gruenewald, M. W.
    Guillemin, T.
    Gutierrez, G.
    Gutierrez, P.
    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.
    Holzbauer, J. L.
    Howley, I.
    Hubacek, Z.
    Hynek, V.
    Iashvili, I.
    Ilchenko, Y.
    Illingworth, R.
    Ito, A. S.
    Jabeen, S.
    Jaffre, M.
    Jayasinghe, A.
    Jeong, M. S.
    Jesik, R.
    Jiang, P.
    Johns, K.
    Johnson, E.
    Johnson, M.
    Jonckheere, A.
    Jonsson, P.
    Joshi, J.
    Jung, A. W.
    Juste, A.
    Kajfasz, E.
    Karmanov, D.
    Katsanos, I.
    Kaur, M.
    Kehoe, R.
    Kermiche, S.
    Khalatyan, N.
    Khanov, A.
    Kharchilava, A.
    Kharzheev, Y. N.
    Kiselevich, I.
    Kohli, J. M.
    Kozelov, A. V.
    Kraus, J.
    Kumar, A.
    Kupco, A.
    Kurca, T.
    Kuzmin, V. A.
    Lammers, S.
    Lebrun, P.
    Lee, H. S.
    Lee, S. W.
    Lee, W. M.
    Lei, X.
    Lellouch, J.
    Li, D.
    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.
    de Sa, R. Lopes
    Luna-Garcia, R.
    Lyon, A. L.
    Maciel, A. K. A.
    Madar, R.
    Magana-Villalba, R.
    Malik, S.
    Malyshev, V. L.
    Mansour, J.
    Martinez-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.
    Narain, M.
    Nayyar, R.
    Neal, H. A.
    Negret, J. P.
    Neustroev, P.
    Nguyen, H. T.
    Nunnemann, T.
    Orduna, J.
    Osman, N.
    Osta, J.
    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.
    Petroff, P.
    Pleier, M. -A
    Podstavkov, V. M.
    Popov, A. V.
    Prewitt, M.
    Price, D.
    Prokopenko, N.
    Qian, J.
    Quadt, A.
    Quinn, B.
    Ratoff, P. N.
    Razumov, I.
    Ripp-Baudot, I.
    Rizatdinova, F.
    Rominsky, M.
    Ross, A.
    Royon, C.
    Rubinov, P.
    Ruchti, R.
    Sajot, G.
    Sanchez-Hernandez, A.
    Sanders, M. P.
    Santos, A. S.
    Savage, G.
    Savitskyi, M.
    Sawyer, L.
    Scanlon, T.
    Schamberger, R. D.
    Scheglov, Y.
    Schellman, H.
    Schwanenberger, C.
    Schwienhorst, R.
    Sekaric, J.
    Severini, H.
    Shabalina, E.
    Shary, V.
    Shaw, S.
    Shchukin, A. A.
    Simak, V.
    Skubic, P.
    Slattery, P.
    Smirnov, D.
    Snow, G. R.
    Snow, J.
    Snyder, S.
    Soeldner-Rembold, S.
    Sonnenschein, L.
    Soustruznik, K.
    Stark, J.
    Stoyanova, D. A.
    Strauss, M.
    Suter, L.
    Svoisky, P.
    Titov, M.
    Tokmenin, V. V.
    Tsai, Y. -T
    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.
    Verkheev, A. Y.
    Vertogradov, L. S.
    Verzocchi, M.
    Vesterinen, M.
    Vilanova, D.
    Vokac, P.
    Wahl, H. D.
    Wang, M. H. L. S.
    Warchol, J.
    Watts, G.
    Wayne, M.
    Weichert, J.
    Welty-Rieger, L.
    Williams, M. R. J.
    Wilson, G. W.
    Wobisch, M.
    Wood, D. R.
    Wyatt, T. R.
    Xie, Y.
    Yamada, R.
    Yang, S.
    Yasuda, T.
    Yatsunenko, Y. A.
    Ye, W.
    Ye, Z.
    Yin, H.
    Yip, K.
    Youn, S. W.
    Yu, J. M.
    Zennamo, J.
    Zhao, T. G.
    Zhou, B.
    Zhu, J.
    Zielinski, M.
    Zieminska, D.
    Zivkovic, L.
    Measurement of the Forward-Backward Asymmetry in the Production lof B-+/- Mesons in p(p)over-bar Collisions at root s=1.96 TeV2015In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 114, no 5Article in journal (Refereed)
    Abstract [en]

    We present a measurement of the forward-backward asymmetry in the production of B-+/- mesons, A(FB)(B-+/-) using B-+/- -> J/ Psi K-+/- decays in 10.4 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV collected by the D0 experiment during Run II of the Tevatron collider. A nonzero asymmetry would indicate a preference for a particular flavor, i.e., b quark or (b) over bar antiquark, to be produced in the direction of the proton beam. We extract A(FB) (B-+/-) from a maximum likelihood fit to the difference between the numbers of forward-and backward-produced B-+/- mesons. We measure an asymmetry consistent with zero: A(FB) (B-+/-) = [-0.24 +/- 0.41 (stat) +/- 0.19 (syst)] %.

  • 9.
    Abbas, Syed Adeel
    et al.
    Center for High Energy Physics, University of the Punjab, Quaid-e-Azam Campus, 54590 Lahore, Pakistan.
    Mahmood, I.
    Center for High Energy Physics, University of the Punjab, Quaid-e-Azam Campus, 54590 Lahore, Pakistan.
    Sajjad, Muhammad
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Noor, N.A.
    Department of Physics, RIPHAH International University, Campus Lahore, Pakistan.
    Mahmood, Q.
    Department of Physics, College of Science, Imam Abdulrahman Bin Faisal University, P O Box 1982, 31441 Dammam, Saudi Arabia.
    Naeem, M.A.
    Chemical Engineering Department, University of the Punjab, Lahore 54000, Pakistan.
    Mahmood, Asif
    College of Engineering Chemical Engineering Department King Saud University Riyadh, Saudi Arabia.
    Ramay, Shahid M.
    Department of Physics and Astronomy, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
    Spinel-type Na2MoO4 and Na2WO4 as promising optoelectronic materials: First-principle DFT calculations2020In: Chemical Physics, ISSN 0301-0104, E-ISSN 1873-4421, Vol. 538, article id 110902Article in journal (Refereed)
    Abstract [en]

    The mechanical, thermodynamic, electronic, and optical properties of Na2MoO4 (NMO) and Na2WO4 (NWO) spinels are elaborated by density functional theory (DFT) based full potential augmented plane wave method (FP-LAPW + lo). Our optimized lattice constants for the studied spinels are in good agreement with that obtained experimentally. The enthalpy of formation ensures the thermodynamic stability of NMO and NWO in the cubic phase. The Born mechanical stability criteria guarantees their mechanical stability, while Poisson ratio (ν) and Pugh's ratio (B/G) infer their brittle behavior. The Debye temperature (θD) is significant for NMO than NWO. The wide bandgap of 3.5 eV for NMO and 4.4 eV for NWO show the maximum absorption in the ultraviolet region that increases their importance for optoelectronic applications. The optical properties are explained in term of dielectric constant, refractive index, absorption of light, reflection, and optical loss factor.

  • 10. Abbas, Syed Sohail
    et al.
    Popov, Sergei Yu
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Optics.
    Compact Er 3+-doped ZBLAN green upconversion fibre laser2011In: World Academy of Science, Engineering and Technology: An International Journal of Science, Engineering and Technology, ISSN 2010-376X, Vol. 78, p. 756-758Article in journal (Refereed)
    Abstract [en]

    In this paper, a fibre laser at 546 nm has been studied for a signal power of -30 dB. Er 3+-doped ZBLAN fibre has been used by upconversion pumping of a 980 nm laser diode. Gain saturation effect has been investigated in detail. Laser performance has also been discussed. An efficiency of 35% has been calculated with a length of 5 mm fibre laser. Results show that Er 3+-doped ZBLAN is a promising candidate for optical amplification at 546 nm.

  • 11.
    Abbasi, R.
    et al.
    Loyola Univ Chicago, Dept Phys, Chicago, IL 60660 USA.
    Botner, Olga
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Burgman, Alexander
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, FREIA.
    Glaser, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Hallgren, Allan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    O'Sullivan, Erin
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Pérez de los Heros, Carlos
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Sharma, Ankur
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Valtonen-Mattila, Nora
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Zhang, Z.
    SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA.
    Combining Maximum-Likelihood with Deep Learning for Event Reconstruction in IceCube2022In: 37th International Cosmic Ray Conference (ICRC 2021) / [ed] Alexander Kappes; Bianca Keilhauer, Sissa Medialab Srl , 2022, article id 1065Conference paper (Refereed)
    Abstract [en]

    The field of deep learning has become increasingly important for particle physics experiments, yielding a multitude of advances, predominantly in event classification and reconstruction tasks. Many of these applications have been adopted from other domains. However, data in the field of physics are unique in the context of machine learning, insofar as their generation process and the laws and symmetries they abide by are usually well understood. Most commonly used deep learning architectures fail at utilizing this available information. In contrast, more traditional likelihood-based methods are capable of exploiting domain knowledge, but they are often limited by computational complexity.

    In this contribution, a hybrid approach is presented that utilizes generative neural networks to approximate the likelihood, which may then be used in a traditional maximum-likelihood setting. Domain knowledge, such as invariances and detector characteristics, can easily be incorporated in this approach. The hybrid approach is illustrated by the example of event reconstruction in IceCube.

    Download full text (pdf)
    fulltext
  • 12. Abbasi, R.
    et al.
    Deoskar, Kunal
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Finley, Chad
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hidvegi, Attila
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jansson, Matti
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Walck, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Zhelnin, P.
    D-Egg: a dual PMT optical module for IceCube2023In: Journal of Instrumentation, E-ISSN 1748-0221, Vol. 18, no 4, article id P04014Article in journal (Refereed)
    Abstract [en]

    The D-Egg, an acronym for Dual optical sensors in an Ellipsoid Glass for Gen2, is one of the optical modules designed for future extensions of the IceCube experiment at the South Pole. The D-Egg has an elongated-sphere shape to maximize the photon-sensitive effective area while maintaining a narrow diameter to reduce the cost and the time needed for drilling of the deployment holes in the glacial ice for the optical modules at depths up to 2700 m. The D-Egg design is utilized for the IceCube Upgrade, the next stage of the IceCube project also known as IceCube-Gen2 Phase 1, where nearly half of the optical sensors to be deployed are D-Eggs. With two 8-inch high-quantum efficiency photomultiplier tubes (PMTs) per module, D-Eggs offer an increased effective area while retaining the successful design of the IceCube digital optical module (DOM). The convolution of the wavelength-dependent effective area and the Cherenkov emission spectrum provides an effective photodetection sensitivity that is 2.8 times larger than that of IceCube DOMs. The signal of each of the two PMTs is digitized using ultra-low-power 14-bit analog-to-digital converters with a sampling frequency of 240 MSPS, enabling a flexible event triggering, as well as seamless and lossless event recording of single-photon signals to multi-photons exceeding 200 photoelectrons within 10 ns. Mass production of D-Eggs has been completed, with 277 out of the 310 D-Eggs produced to be used in the IceCube Upgrade. In this paper, we report the design of the D-Eggs, as well as the sensitivity and the single to multi-photon detection performance of mass-produced D-Eggs measured in a laboratory using the built-in data acquisition system in each D-Egg optical sensor module.

  • 13. Abbasi, Rasha
    et al.
    Deoskar, Kunar
    Stockholm Univ, Oskar Klein Ctr, SE-10691 Stockholm, Sweden.
    Finley, Chad
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hidvegi, Attila
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hultqvist, Klas
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jansson, Matti
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Walck, Christian
    Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Zhelnin, P.
    Limits on Neutrino Emission from GRB 221009A from MeV to PeV Using the IceCube Neutrino Observatory2023In: Astrophysical Journal Letters, ISSN 2041-8205, E-ISSN 2041-8213, Vol. 946, no 1, article id L26Article in journal (Refereed)
    Abstract [en]

    Gamma-ray bursts (GRBs) have long been considered a possible source of high-energy neutrinos. While no correlations have yet been detected between high-energy neutrinos and GRBs, the recent observation of GRB 221009A-the brightest GRB observed by Fermi-GBM to date and the first one to be observed above an energy of 10 TeV-provides a unique opportunity to test for hadronic emission. In this paper, we leverage the wide energy range of the IceCube Neutrino Observatory to search for neutrinos from GRB 221009A. We find no significant deviation from background expectation across event samples ranging from MeV to PeV energies, placing stringent upper limits on the neutrino emission from this source.

  • 14.
    Abdullha, Khalid A.
    et al.
    Department of Civil Engineering, College of Engineering, Mosul University, Mosul, Iraq.
    Abdullha, Aziz I.
    Department of Civil Engineering, College of Engineering, Tikrit University, Tikrit, Iraq.
    Abdul-Razzak, Ayad A.
    Department of Civil Engineering, College of Engineering, Mosul University, Mosul, Iraq.
    Al-Gburi, Majid
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Mechanical properties, thermal and chemical effect of polymer cotton bars reinforced with carbon / glass fiber2024In: Australian Journal of Mechanical Engineering, ISSN 1448-4846, Vol. 22, no 3, p. 592-602Article in journal (Refereed)
    Abstract [en]

    Many researchers are interested in using natural fibres to treat due to recent advancements in polymer characteristics. The mechanical properties of three types of bars are studied in this paper: Cotton Fibre-Reinforced Polymer bars, Cotton/Carbon Fibre-Reinforced Polymer bars, and Cotton/Glass Fibre-Reinforced Polymer bars. The goal of the paper was to create low-cost bars with comparable mechanical performance and corrosion resistance to steel reinforcement. The bars were made using two methods: fibres immersed in polymer and fibres coated with polymer by repeated tension and relaxation of fibres. The second method produced better results in terms of the tensile strength of Cot.CFRP, Cot.GFRP, and Cot.FRP bars, which were 688, 477, and 284 MPa, respectively, and the stress–strain curve revealed brittle behaviour for all bars and modulus of elasticity of 43, 31 and 22 GPa. When sand was put on the bar’s surface, the bars demonstrated a good connection with the concrete. It also showed good resistance to moisture, alkaline solutions and acids, as well as heat resistance at temperatures below 200°C.

    Download full text (pdf)
    fulltext
  • 15.
    Abedi-Valugerdi, Manuchehr
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Mercury and silver induce B cell activation and anti-nucleolar autoantibody production in outbred mouse stocks: are environmental factors more important than the susceptibility genes in connection with autoimmunity?2009In: Clinical and Experimental Immunology, ISSN 0009-9104, E-ISSN 1365-2249, Vol. 155, no 1, p. 117-124Article in journal (Refereed)
    Abstract [en]

    Environmental and predisposing genetic factors are known to play a crucial role in the development of systemic autoimmune diseases. With respect to the role of environmental factors, it is not known how and to what extent they contribute to the initiation and exacerbation of systemic autoimmunity. In the present study, I considered this issue and asked if environmental factors can induce autoimmunity in the absence of specific susceptible genes. The development of genetically controlled mercury- and silver-induced B cell activation and anti-nucleolar autoantibodies (ANolA) production in genetically heterozygous outbred Institute of Cancer Research (ICR), Naval Medical Research Institute (NMRI) and Black Swiss mouse stocks were analysed. Four weeks of treatment with both mercury and silver induced a strong B cell activation characterized by increased numbers of splenic antibody-secreting cells of at least one or more immunoglobulin (Ig) isotype(s) in all treated stocks. The three stocks also exhibited a marked increase in the serum IgE levels in response to mercury, but not silver. More importantly, in response to mercury a large numbers of ICR (88%), NMRI (96%) and Black Swiss (100%) mice produced different levels of IgG1 and IgG2a ANolA (a characteristic which is linked strictly to the H-2 genes). Similarly, but at lower magnitudes, treatment with silver also induced the production of IgG1 and IgG2a ANolA in 60% of ICR, 75% of NMRI and 100% of Black Swiss mice. Thus, the findings of this study suggest that long-term exposure to certain environmental factors can activate the immune system to produce autoimmunity per se, without requiring specific susceptible genes.

  • 16.
    Abel, Martin
    et al.
    Department of Physics, University of Texas, Austin, TX 78712, United States.
    Frommhold, Lothar
    Department of Physics, University of Texas, Austin, TX 78712, United States.
    Gustafsson, Magnus
    Department of Chemistry, University of Gothenburg, SE 412 96 Gothenburg, Sweden.
    Collision-induced absorption at wavelengths near 5 μm by dense hydrogen gas2009In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 131, no 18, article id 181102Article in journal (Refereed)
  • 17.
    Abel, Martin
    et al.
    University of Texas, Physics Department.
    Frommhold, Lothar
    University of Texas, Physics Department.
    Wang, Fei
    Physics Department, Beijing Institute of Technology, China, University of Texas, Physics Department.
    Gustafsson, Magnus
    Department of Chemistry, University of Gothenburg.
    Li, Xiaoping
    Department of Chemistry, Michigan State University.
    Hunt, Katherine L.C.
    Department of Chemistry, Michigan State University, East Lansing, Department of Chemistry, Michigan State University.
    Collision-induced absorption by supermolecular complexes from a new potential energy and induced dipole surface, suited for calculations up to thousands of kelvin2010In: 20th International Conference on Spectral Line Shapes: St. John's, Newfoundland, Canada, 6 - 11 June 2010 ; [20th ICSLS] / [ed] John K.C. Lewis; Adriana Predoi-Cross, Melville, NY: American Institute of Physics (AIP), 2010, p. 251-257Conference paper (Refereed)
    Abstract [en]

    Absorption by pairs of H2 molecules is an important opacity source in the atmospheres of the outer planets, and thus of special astronomical interest. The emission spectra of cool white dwarf stars differ significantly from the expected blackbody spectra, amongst other reasons due to absorption by H2-H2, H2-He, and H2-H collisional complexes in the stellar atmospheres. To model the radiative processes in these atmospheres, which have temperatures of several thousand kelvin, one needs accurate knowledge of the induced dipole (ID) and potential energy surfaces (PES) of such collisional complexes. These come from quantum-chemical calculations with the H2 bonds stretched or compressed far from equilibrium. Laboratory measurements of collision-induced (CI) absorption exist only at much lower temperature. For H2 pairs at room temperature, the calculated spectra of the rototranslational band, the fundamental band, and the first overtone match the experimental data very well. In addition, with the newly obtained IDS it became possible to reproduce the measurements in the far blue wing of the rototranslational spectrum of H2 at 77.5 K, as well as at 300 K. Similarly good agreement between theory and measurement is seen in the fundamental band of molecular deuterium at room temperature. Furthermore, we also show the calculated absorption spectra of H2-He at 600 K and of H2-H2 at 2,000 K, for which there are no experimental data for comparison

  • 18.
    Abergel, David
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Edge, Jonathan M.
    Balatsky, Alexander V.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    The role of spin-orbit coupling in topologically protected interface states in Dirac materials2014In: New Journal of Physics, E-ISSN 1367-2630, Vol. 16, p. 065012-Article in journal (Refereed)
    Abstract [en]

    We highlight the fact that two-dimensional (2D) materials with Dirac-like low energy band structures and spin-orbit coupling (SOC) will produce linearly dispersing topologically protected Jackiw-Rebbi modes at interfaces where the Dirac mass changes sign. These modes may support persistent spin or valley currents parallel to the interface, and the exact arrangement of such topologically protected currents depends crucially on the details of the SOC in the material. As examples, we discuss buckled 2D hexagonal lattices such as silicene or germanene, and transition metal dichalcogenides such as MoS2.

  • 19.
    Abidin, Aysajan
    et al.
    Linköping University, Department of Electrical Engineering, Information Coding. Linköping University, The Institute of Technology.
    Pacher, Christoph
    Austrian Institute of Technology, Austria.
    Lorünser, Thomas
    Austrian Institute of Technology, Austria.
    Larsson, Jan-Åke
    Linköping University, Department of Electrical Engineering, Information Coding. Linköping University, The Institute of Technology.
    Peev, Momtchil
    Austrian Institute of Technology, Austria.
    Quantum cryptography and authentication with low key-consumption2011In: Proceedings of SPIE - The International Society for Optical Engineering, 2011, p. 818916-Conference paper (Refereed)
    Abstract [en]

    Quantum Key Distribution (QKD - also referred to as Quantum Cryptography) is a technique for secret key agreement. It has been shown that QKD rigged with Information-Theoretic Secure (ITS) authentication (using secret key) of the classical messages transmitted during the key distribution protocol is also ITS. Note, QKD without any authentication can trivially be broken by man-in-the-middle attacks. Here, we study an authentication method that was originally proposed because of its low key consumption; a two-step authentication that uses a publicly known hash function, followed by a secret strongly universal2 hash function, which is exchanged each round. This two-step authentication is not information-theoretically secure but it was argued that nevertheless it does not compromise the security of QKD. In the current contribution we study intrinsic weaknesses of this approach under the common assumption that the QKD adversary has access to unlimited resources including quantum memories. We consider one implementation of Quantum Cryptographic protocols that use such authentication and demonstrate an attack that fully extract the secret key. Even including the final key from the protocol in the authentication does not rule out the possibility of these attacks. To rectify the situation, we propose a countermeasure that, while not informationtheoretically secure, restores the need for very large computing power for the attack to work. Finally, we specify conditions that must be satisfied by the two-step authentication in order to restore informationtheoretic security.

  • 20. Ablikim, M.
    et al.
    Achasov, M. N.
    Ai, X. C.
    Albayrak, O.
    Albrecht, M.
    Ambrose, D. J.
    Amoroso, A.
    An, F. F.
    An, Q.
    Bai, J. Z.
    Ferroli, R. Baldini
    Ban, Y.
    Bennett, D. W.
    Bennett, J. V.
    Bertani, M.
    Bettoni, D.
    Bian, J. M.
    Bianchi, F.
    Boger, E.
    Bondarenko, O.
    Boyko, I.
    Briere, R. A.
    Cai, H.
    Cai, X.
    Cakir, O.
    Calcaterra, A.
    Cao, G. F.
    Cetin, S. A.
    Chang, J. F.
    Chelkov, G.
    Chen, G.
    Chen, H. S.
    Chen, H. Y.
    Chen, J. C.
    Chen, M. L.
    Chen, S. J.
    Chen, X.
    Chen, X. R.
    Chen, Y. B.
    Cheng, H. P.
    Chu, X. K.
    Cibinetto, G.
    Cronin-Hennessy, D.
    Dai, H. L.
    Dai, J. P.
    Dbeyssi, A.
    Dedovich, D.
    Deng, Z. Y.
    Denig, A.
    Denysenko, I.
    Destefanis, M.
    De Mori, F.
    Ding, Y.
    Dong, C.
    Dong, J.
    Dong, L. Y.
    Dong, M. Y.
    Du, S. X.
    Duan, P. F.
    Fan, J. Z.
    Fang, J.
    Fang, S. S.
    Fang, X.
    Fang, Y.
    Fava, L.
    Feldbauer, F.
    Felici, G.
    Feng, C. Q.
    Fioravanti, E.
    Fritsch, M.
    Fu, C. D.
    Gao, Q.
    Gao, Y.
    Garzia, I.
    Goetzen, K.
    Gong, W. X.
    Gradl, W.
    Greco, M.
    Gu, M. H.
    Gu, Y. T.
    Guan, Y. H.
    Guo, A. Q.
    Guo, L. B.
    Guo, T.
    Guo, Y.
    Guo, Y. P.
    Haddadi, Z.
    Hafner, A.
    Han, S.
    Han, Y. L.
    Harris, F. A.
    He, K. L.
    He, Z. Y.
    Held, T.
    Heng, Y. K.
    Hou, Z. L.
    Hu, C.
    Hu, H. M.
    Hu, J. F.
    Hu, T.
    Hu, Y.
    Huang, G. M.
    Huang, G. S.
    Huang, H. P.
    Huang, J. S.
    Huang, X. T.
    Huang, Y.
    Hussain, T.
    Ji, Q.
    Ji, Q. P.
    Ji, X. B.
    Ji, X. L.
    Jiang, L. L.
    Jiang, L. W.
    Jiang, X. S.
    Jiao, J. B.
    Jiao, Z.
    Jin, D. P.
    Jin, S.
    Johansson, Tord
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Julin, A.
    Kalantar-Nayestanaki, N.
    Kang, X. L.
    Kang, X. S.
    Kavatsyuk, M.
    Ke, B. C.
    Kliemt, R.
    Kloss, B.
    Kolcu, O. B.
    Kopf, B.
    Kornicer, M.
    Kuehn, W.
    Kupsc, Andrzej
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Lai, W.
    Lange, J. S.
    Lara, M.
    Larin, P.
    Li, C. H.
    Li, Cheng
    Li, D. M.
    Li, F.
    Li, G.
    Li, H. B.
    Li, J. C.
    Li, Jin
    Li, K.
    Li, P. R.
    Li, T.
    Li, W. D.
    Li, W. G.
    Li, X. L.
    Li, X. M.
    Li, X. N.
    Li, X. Q.
    Li, Z. B.
    Liang, H.
    Liang, Y. F.
    Liang, Y. T.
    Liao, G. R.
    Lin, D. X.
    Liu, B. J.
    Liu, C. L.
    Liu, C. X.
    Liu, F. H.
    Liu, Fang
    Liu, Feng
    Liu, H. B.
    Liu, H. H.
    Liu, H. M.
    Liu, J.
    Liu, J. P.
    Liu, J. Y.
    Liu, K.
    Liu, K. Y.
    Liu, L. D.
    Liu, P. L.
    Liu, Q.
    Liu, S. B.
    Liu, X.
    Liu, X. X.
    Liu, Y. B.
    Liu, Z. A.
    Liu, Zhiqiang
    Liu, Zhiqing
    Loehner, H.
    Lou, X. C.
    Lu, H. J.
    Lu, J. G.
    Lu, R. Q.
    Lu, Y.
    Lu, Y. P.
    Luo, C. L.
    Luo, M. X.
    Luo, T.
    Luo, X. L.
    Lv, M.
    Lyu, X. R.
    Ma, F. C.
    Ma, H. L.
    Ma, L. L.
    Ma, Q. M.
    Ma, S.
    Ma, T.
    Ma, X. N.
    Ma, X. Y.
    Maas, F. E.
    Maggiora, M.
    Malik, Q. A.
    Mao, Y. J.
    Mao, Z. P.
    Marcello, S.
    Messchendorp, J. G.
    Min, J.
    Min, T. J.
    Mitchell, R. E.
    Mo, X. H.
    Mo, Y. J.
    Morales, C. Morales
    Moriya, K.
    Muchnoi, N. Yu.
    Muramatsu, H.
    Nefedov, Y.
    Nerling, F.
    Nikolaev, I. B.
    Ning, Z.
    Nisar, S.
    Niu, S. L.
    Niu, X. Y.
    Olsen, S. L.
    Ouyang, Q.
    Pacetti, S.
    Patteri, P.
    Pelizaeus, M.
    Peng, H. P.
    Peters, K.
    Ping, J. L.
    Ping, R. G.
    Poling, R.
    Pu, Y. N.
    Qi, M.
    Qian, S.
    Qiao, C. F.
    Qin, L. Q.
    Qin, N.
    Qin, X. S.
    Qin, Y.
    Qin, Z. H.
    Qiu, J. F.
    Rashid, K. H.
    Redmer, C. F.
    Ren, H. L.
    Ripka, M.
    Rong, G.
    Ruan, X. D.
    Santoro, V.
    Sarantsev, A.
    Savrie, M.
    Schönning, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Schumann, S.
    Shan, W.
    Shao, M.
    Shen, C. P.
    Shen, P. X.
    Shen, X. Y.
    Sheng, H. Y.
    Shepherd, M. R.
    Song, W. M.
    Song, X. Y.
    Sosio, S.
    Spataro, S.
    Spruck, B.
    Sun, G. X.
    Sun, J. F.
    Sun, S. S.
    Sun, Y. J.
    Sun, Y. Z.
    Sun, Z. J.
    Sun, Z. T.
    Tang, C. J.
    Tang, X.
    Tapan, I.
    Thorndike, E. H.
    Tiemens, M.
    Toth, D.
    Ullrich, M.
    Uman, I.
    Varner, G. S.
    Wang, B.
    Wang, B. L.
    Wang, D.
    Wang, D. Y.
    Wang, K.
    Wang, L. L.
    Wang, L. S.
    Wang, M.
    Wang, P.
    Wang, P. L.
    Wang, Q. J.
    Wang, S. G.
    Wang, W.
    Wang, X. F.
    Wang, Y. D.
    Wang, Y. F.
    Wang, Y. Q.
    Wang, Z.
    Wang, Z. G.
    Wang, Z. H.
    Wang, Z. Y.
    Weber, T.
    Wei, D. H.
    Wei, J. B.
    Weidenkaff, P.
    Wen, S. P.
    Wiedner, U.
    Wolke, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Nuclear Physics.
    Wu, L. H.
    Wu, Z.
    Xia, L. G.
    Xia, Y.
    Xiao, D.
    Xiao, Z. J.
    Xie, Y. G.
    Xu, G. F.
    Xu, L.
    Xu, Q. J.
    Xu, Q. N.
    Xu, X. P.
    Yan, L.
    Yan, W. B.
    Yan, W. C.
    Yan, Y. H.
    Yang, H. X.
    Yang, L.
    Yang, Y.
    Yang, Y. X.
    Ye, H.
    Ye, M.
    Ye, M. H.
    Yin, J. H.
    Yu, B. X.
    Yu, C. X.
    Yu, H. W.
    Yu, J. S.
    Yuan, C. Z.
    Yuan, W. L.
    Yuan, Y.
    Yuncu, A.
    Zafar, A. A.
    Zallo, A.
    Zeng, Y.
    Zhang, B. X.
    Zhang, B. Y.
    Zhang, C.
    Zhang, C. C.
    Zhang, D. H.
    Zhang, H. H.
    Zhang, H. Y.
    Zhang, J. J.
    Zhang, J. L.
    Zhang, J. Q.
    Zhang, J. W.
    Zhang, J. Y.
    Zhang, J. Z.
    Zhang, K.
    Zhang, L.
    Zhang, S. H.
    Zhang, X. J.
    Zhang, X. Y.
    Zhang, Y.
    Zhang, Y. H.
    Zhang, Z. H.
    Zhang, Z. P.
    Zhang, Z. Y.
    Zhao, G.
    Zhao, J. W.
    Zhao, J. Y.
    Zhao, J. Z.
    Zhao, Lei
    Zhao, Ling
    Zhao, M. G.
    Zhao, Q.
    Zhao, Q. W.
    Zhao, S. J.
    Zhao, T. C.
    Zhao, Y. B.
    Zhao, Z. G.
    Zhemchugov, A.
    Zheng, B.
    Zheng, J. P.
    Zheng, W. J.
    Zheng, Y. H.
    Zhong, B.
    Zhou, L.
    Zhou, Li
    Zhou, X.
    Zhou, X. K.
    Zhou, X. R.
    Zhou, X. Y.
    Zhu, K.
    Zhu, K. J.
    Zhu, S.
    Zhu, X. L.
    Zhu, Y. C.
    Zhu, Y. S.
    Zhu, Z. A.
    Zhuang, J.
    Zou, B. S.
    Zou, J. H.
    Precision measurement of the D*(0) decay branching fractions2015In: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 91, no 3, article id 031101Article in journal (Refereed)
    Abstract [en]

    Using 482 pb(-1) of data taken at root s = 4.009 GeV, we measure the branching fractions of the decays of D*(0) into D-0 pi(0) and D-0 gamma to be B(D*(0) -> D-0 pi(0)) = (65.5 +/- 0.8 +/- 0.5)% and B(D*(0) -> D0 gamma) = (34.5 +/- 0.8 +/- 0.5)%, respectively, by assuming that the D*(0) decays only into these two modes. The ratio of the two branching fractions is B(D*(0) -> D-0 pi(0))/B(D*(0) -> D-0 gamma) = 1.90 +/- 0.07 +/- 0.05, which is independent of the assumption made above. The first uncertainties are statistical and the second ones systematic. The precision is improved by a factor of 3 compared to the present world average values.

  • 21.
    Aboulsaad, Mustafa
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering.
    El Tahan, Ayman
    Soliman, Moataz
    El-Sheikh, Shaker
    Ebrahim, Shaker
    Thermal oxidation of sputtered nickel nano-film as hole transport layer for high performance perovskite solar cells2019In: Journal of materials science. Materials in electronics, ISSN 0957-4522, E-ISSN 1573-482X, Vol. 30, no 22, p. 19792-19803Article in journal (Refereed)
    Abstract [en]

    The effect of rapid oxidation temperature on the sputtered nickel (Ni) films to act as a hole transport layer (HTL) for perovskite solar cell (PSCs) was investigated. A nano-sputtered Ni film with a thickness about 100 nm was oxidized at a range of different oxidation temperatures between 350 and 650 °C to work as HTL in an inverted p–i–n configuration. DC Hall measurement in van der Pauw configuration and photoluminescence spectroscopy were used to measure the charge’s mobility and extraction of nickel oxide (NiO) films. The behaviour of the carrier concentration measurements of NiO layers at different oxidation temperatures showed that the Ni layer oxidized at 450 °C had the highest carrier concentration among the other samples. The performance measurements of the fabricated PSCs showed that the nickel oxide hole-transporting layer which has been oxidized at the optimum oxidation temperature of 450 °C has the highest power conversion efficiency (PCE) of 12.05%. Moreover, the characteristic parameters of the optimum cell such as the open-circuit voltage (VOC), short-circuit current density (JSC) and fill factor (FF) were 0.92 V, 19.80 mA/cm2 and 0.331, respectively.

    Download full text (pdf)
    fulltext
  • 22. Abramov, V.
    et al.
    Paal, E.Tallinn University of Technology.Silvestrov, Sergei D.Mälardalen University, School of Education, Culture and Communication, Educational Sciences and Mathematics.Stolin, A.Chalmers University of Techology.
    Proceedings of the 3rd Baltic-Nordic Workshop “Algebra, Geometry, and Mathematical Physics”2008Conference proceedings (editor) (Refereed)
  • 23. Abramowski, A.
    et al.
    Acero, F.
    Aharonian, F.
    Akhperjanian, A. G.
    Anton, G.
    Balzer, A.
    Barnacka, A.
    Becherini, Yvonne
    Université Paris Diderot.
    Becker, J.
    Bernloehr, K.
    Birsin, E.
    Biteau, J.
    Bochow, A.
    Boisson, C.
    Bolmont, J.
    Bordas, P.
    Brucker, J.
    Brun, F.
    Brun, P.
    Bulik, T.
    Buesching, I.
    Carrigan, S.
    Casanova, S.
    Cerruti, M.
    Chadwick, P. M.
    Charbonnier, A.
    Chaves, R. C. G.
    Cheesebrough, A.
    Cologna, G.
    Conrad, J.
    Couturier, C.
    Dalton, M.
    Daniel, M. K.
    Davids, I. D.
    Degrange, B.
    Deil, C.
    Dickinson, H. J.
    Djannati-Atai, A.
    Domainko, W.
    Drury, L. O 'C.
    Dubus, G.
    Dutson, K.
    Dyks, J.
    Dyrda, M.
    Egberts, K.
    Eger, P.
    Espigat, P.
    Fallon, L.
    Fegan, S.
    Feinstein, F.
    Fernandes, M. V.
    Fiasson, A.
    Fontaine, G.
    Foerster, A.
    Fuessling, M.
    Gajdus, M.
    Gallant, Y. A.
    Garrigoux, T.
    Gast, H.
    Gerard, L.
    Giebels, B.
    Glicenstein, J. F.
    Glueck, B.
    Goering, D.
    Grondin, M. -H
    Haeffner, S.
    Hague, J. D.
    Hahn, J.
    Hampf, D.
    Harris, J.
    Hauser, M.
    Heinz, S.
    Heinzelmann, G.
    Henri, G.
    Hermann, G.
    Hillert, A.
    Hinton, J. A.
    Hofmann, W.
    Hofverberg, P.
    Holler, M.
    Horns, D.
    Jacholkowska, A.
    Jahn, C.
    Jamrozy, M.
    Jung, I.
    Kastendieck, M. A.
    Katarzynski, K.
    Katz, U.
    Kaufmann, S.
    Khelifi, B.
    Klochkov, D.
    Kluzniak, W.
    Kneiske, T.
    Komin, Nu
    Kosack, K.
    Kossakowski, R.
    Krayzel, F.
    Laffon, H.
    Lamanna, G.
    Lenain, J. -P
    Lennarz, D.
    Lohse, T.
    Lopatin, A.
    Lu, C. -C
    Marandon, V.
    Marcowith, A.
    Masbou, J.
    Maurin, G.
    Maxted, N.
    Mayer, M.
    McComb, T. J. L.
    Medina, M. C.
    Mehault, J.
    Moderski, R.
    Mohamed, M.
    Moulin, E.
    Naumann, C. L.
    Naumann-Godo, M.
    de Naurois, M.
    Nedbal, D.
    Nekrassov, D.
    Nguyen, N.
    Nicholas, B.
    Niemiec, J.
    Nolan, S. J.
    Ohm, S.
    Wilhelmi, E. de Ona
    Opitz, B.
    Ostrowski, M.
    Oya, I.
    Panter, M.
    Arribas, M. Paz
    Pekeur, N. W.
    Pelletier, G.
    Perez, J.
    Petrucci, P. -O
    Peyaud, B.
    Pita, S.
    Puehlhofer, G.
    Punch, Michael
    Univ Paris Diderot, APC, AstroParticule & Cosmology, CNRS,IN2P3,CEA,Irfu, Observ Paris,Sorbonne Paris C, 10 Rue Alice Domon & Leonie Duquet, F-75205 Paris 13, France.
    Quirrenbach, A.
    Raue, M.
    Reimer, A.
    Reimer, O.
    Renaud, M.
    de los Reyes, R.
    Rieger, F.
    Ripken, J.
    Rob, L.
    Rosier-Lees, S.
    Rowell, G.
    Rudak, B.
    Rulten, C. B.
    Sahakian, V.
    Sanchez, D. A.
    Santangelo, A.
    Schlickeiser, R.
    Schulz, A.
    Schwanke, U.
    Schwarzburg, S.
    Schwemmer, S.
    Sheidaei, F.
    Skilton, J. L.
    Sol, H.
    Spengler, G.
    Stawarz, L.
    Steenkamp, R.
    Stegmann, C.
    Stinzing, F.
    Stycz, K.
    Sushch, I.
    Szostek, A.
    Tavernet, J. -P
    Terrier, R.
    Tluczykont, M.
    Valerius, K.
    van Eldik, C.
    Vasileiadis, G.
    Venter, C.
    Viana, A.
    Vincent, P.
    Voelk, H. J.
    Volpe, F.
    Vorobiov, S.
    Vorster, M.
    Wagner, S. J.
    Ward, M.
    White, R.
    Wierzcholska, A.
    Zacharias, M.
    Zajczyk, A.
    Zdziarski, A. A.
    Zech, A.
    Zechlin, H. -S
    Spectral Analysis and Interpretation of the γ-ray Emission from the Starburst Galaxy NGC 2532012In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 757, no 2, p. 158-Article in journal (Refereed)
    Abstract [en]

    Very high energy (VHE; E >= 100 GeV) and high-energy (HE; 100 MeV <= E <= 100 GeV) data from gamma-ray observations performed with the H. E. S. S. telescope array and the Fermi-LAT instrument, respectively, are analyzed in order to investigate the non-thermal processes in the starburst galaxy NGC 253. The VHE gamma-ray data can be described by a power law in energy with differential photon index Gamma = 2.14 +/- 0.18(stat) +/- 0.30(sys) and differential flux normalization at 1 TeV of F-0 = (9.6 +/- 1.5(stat)(+5.7, -2.9)(sys)) x 10(-14) TeV-1 cm(-2) s(-1). A power-law fit to the differential HE gamma-ray spectrum reveals a photon index of Gamma = 2.24 +/- 0.14(stat) +/- 0.03(sys) and an integral flux between 200 MeV and 200 GeV of F(0.2-200 GeV) = (4.9 +/- 1.0(stat) +/- 0.3(sys)) x 10(-9) cm(-2) s(-1). No evidence for a spectral break or turnover is found over the dynamic range of both the LAT instrument and the H.E.S.S. experiment: a combined fit of a power law to the HE and VHE gamma-ray data results in a differential photon index Gamma = 2.34 +/- 0.03 with a p-value of 30%. The gamma-ray observations indicate that at least about 20% of the energy of the cosmic rays (CRs) capable of producing hadronic interactions is channeled into pion production. The smooth alignment between the spectra in the HE and VHE gamma-ray domain suggests that the same transport processes dominate in the entire energy range. Advection is most likely responsible for charged particle removal from the starburst nucleus from GeV to multiple TeV energies. In a hadronic scenario for the gamma-ray production, the single overall power-law spectrum observed would therefore correspond to the mean energy spectrum produced by the ensemble of CR sources in the starburst region.

  • 24.
    Abramson, Nils H.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Appearance of Objects at Relativistic Velocities, a Holographic Approach2010In: SEARCH FOR FUNDAMENTAL THEORY / [ed] Amoroso RL, Rowlands P, Jeffers S, MELVILLE, NY: AMER INST PHYSICS , 2010, Vol. 1316, p. 118-124Conference paper (Refereed)
    Abstract [en]

    A diagram borrowed from holographic interferometry has been applied to visualize phenomena in Special Relativity. It displays how a sphere of observation is by velocity elongated into an ellipsoid of observation and produces graphically all the well accepted equations of Einsteins Special Relativity. The Lorentz contraction, however, is explained as an elongation of the measuring rod, the meter, which by definition is based on either a specific number of wavelengths or the velocity of light multiplied by time. The diagram displays the total apparent object distortions including not only the Lorentz contraction but also larger apparent contractions and elongations caused by the classic Doppler Effect. The reasons of these deformations are the delays caused by variations in distance from observer to different parts of the moving object. In this paper we do not discuss the meaning of apparent, as compared to real, deformation.

  • 25.
    Abramson, Nils H.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Elliptic visualizing optical resolution and kinetic energy2017In: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 56, no 5, p. 1413-1416Article in journal (Refereed)
    Abstract [en]

    Diffraction limited resolution as introduced by Abbe is well established, but interference limited resolution was not well known until holographic interferometry was introduced. The holodiagram is used to simplify holography and in a new way visualize the distribution, ratio, and relation among resolutions of different optical techniques, including relativistic phenomena. Resolution, when measured by optical methods based on the number of wavelengths of light, is defined in the following as the minimum distance between resolvable points, or the largest object needed to be resolved. Everywhere in the diagram this resolution is represented by two orthogonal diagonals of rhombs.

  • 26.
    Abramson, Nils H.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    Holodiagram: elliptic visualizing interferometry, relativity, and light-in-flight2014In: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 53, no 11, p. 2398-2404Article in journal (Refereed)
    Abstract [en]

    In holographic interferometry, there is usually a static distance separating the point of illumination and the point of observation. In Special Relativity, this separation is dynamic and is caused by the velocity of the observer. The corrections needed to compensate for these separations are similar in the two fields. We use the ellipsoids of the holodiagram for measurement and in a graphic way to explain and evaluate optical resolution, gated viewing, radar, holography, three-dimensional interferometry, Special Relativity, and light-in-flight recordings. Lorentz contraction together with time dilation is explained as the result of the eccentricity of the measuring ellipsoid, caused by its velocity. The extremely thin ellipsoid of the very first light appears as a beam aimed directly at the observer, which might explain the wave or ray duality of light and entanglement. Finally, we introduce the concept of ellipsoids of observation.

  • 27.
    Abramson, Nils H.
    KTH, School of Industrial Engineering and Management (ITM).
    Holographic Metrology and Basic Physics2013In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 415, no 1, p. 012030-Article in journal (Refereed)
    Abstract [en]

    A short pulse of light is emitted from one point followed by a short observation from another point separated in space and time from the first. Even if space is full of scattering particles no sphere of expanding light is seen from outside by the observer, instead he finds himself inside an ellipsoid of light. We use this ellipsoid for measurement and in a graphic way to explain and evaluate optical resolution, gated viewing, radar, holography, 3-D interferometry and Special Relativity. In the later case the Lorentz Contraction together with the Time Dilation are explained as results of the eccentricity of the measuring ellipsoid, caused by its velocity. Finally, the extremely thin ellipsoid of the very first light appears as a beam aimed directly at the observer which might explain the wave or ray duality of light and entanglement.

  • 28.
    Abramson, Nils H.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Metrology and Optics.
    INSTANT RANDOM INFORMATION2010In: SEARCH FOR FUNDAMENTAL THEORY / [ed] Amoroso RL, Rowlands P, Jeffers S, MELVILLE, NY: AMER INST PHYSICS , 2010, Vol. 1316, p. 113-117Conference paper (Refereed)
    Abstract [en]

    Information is carried by matter or by energy and thus Einstein stated that "no information can travel faster than light." He also was very critical to the "Spooky action at distance" as described in Quantum Physics. However, many verified experiments have proven that the "Spooky actions" not only work at distance but also that they travel at a velocity faster than light, probably at infinite velocity. Examples are Young's fringes at low light levels or entanglements. My explanation is that this information is without energy. In the following I will refer to this spooky information as exformation, where "ex-" refers to existence, the information is not transported in any way, it simply exists. Thus Einstein might have been wrong when he stated that no information can travel faster than light. But he was is right in that no detectable information can travel faster than light. Phenomena connected to entanglement appear at first to be exceptions, but in those cases the information can not be reconstructed until energy is later sent in the form of correlation using ordinary information at the velocity of light. In entanglement we see that even if the exformation can not be detected directly because its luck of energy it still can influence what happens at random, bemuse in Quantum Physics there is by definition no energy difference between two states that happen randomly.

  • 29. Abrikosov, I. A.
    et al.
    Ponomareva, A. V.
    Barannikova, S. A.
    Hellman, O.
    Vekilova, O.Yu.
    Simak, S. I.
    Ruban, Andrei V.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Multiscale approach to theoretical simulations of materials for nuclear energy applications: Fe-Cr and Zr-based alloys2013In: Advances in materials for nuclear energy: symposium held November 25-30, Boston, Massachusetts, U.S.A., Materials Research Society, 2013, p. 3-14Conference paper (Refereed)
    Abstract [en]

    We review basic ideas behind state-of-the-art techniques for first-principles theoretical simulations of the phase stabilities and properties of alloys. We concentrate on methods that allow for an efficient treatment of compositional and thermal disorder effects. In particular, we present novel approach to evaluate free energy for strongly anharmonic systems. Theoretical tools are then employed in studies of two materials systems relevant for nuclear energy applications: Fe-Cr and Zr-based alloys. In particular, we investigate the effect of hydrostatic pressure and multicomponent alloying on the mixing enthalpy of Fe-Cr alloys, and show that in the ferromagnetic state both of them reduce the alloy stability at low Cr concentration. For Zr-Nb alloys, we demonstrate how microscopic parameters calculated from first-principles can be used in higher-level models.

  • 30.
    Achenbach, Jan-Ole
    et al.
    Rhein Westfal TH Aachen, Mat Chem, Aachen, Germany.
    Mraz, Stanislav
    Rhein Westfal TH Aachen, Mat Chem, Aachen, Germany.
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Schneider, Jochen M.
    Rhein Westfal TH Aachen, Mat Chem, Aachen, Germany.
    Correlative Experimental and Theoretical Investigation of the Angle-Resolved Composition Evolution of Thin Films Sputtered from a Compound Mo2BC Targe2019In: Coatings, ISSN 2079-6412, Vol. 9, no 3, article id 206Article in journal (Refereed)
    Abstract [en]

    The angle-resolved composition evolution of Mo-B-C thin films deposited from a Mo2BC compound target was investigated experimentally and theoretically. Depositions were carried out by direct current magnetron sputtering (DCMS) in a pressure range from 0.09 to 0.98 Pa in Ar and Kr. The substrates were placed at specific angles α with respect to the target normal from 0 to ±67.5°. A model based on TRIDYN and SIMTRA was used to calculate the influence of the sputtering gas on the angular distribution function of the sputtered species at the target, their transport through the gas phase, and film composition. Experimental pressure- and sputtering gas-dependent thin film chemical composition data are in good agreement with simulated angle-resolved film composition data. In Ar, the pressure-induced film composition variations at a particular α are within the error of the EDX measurements. On the contrary, an order of magnitude increase in Kr pressure results in an increase of the Mo concentration measured at α = 0° from 36 at.% to 43 at.%. It is shown that the mass ratio between sputtering gas and sputtered species defines the scattering angle within the collision cascades in the target, as well as for the collisions in the gas phase, which in turn defines the angle- and pressure-dependent film compositions.

    Download full text (pdf)
    FULLTEXT01
  • 31.
    Adbo, Johanna
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Theoretical Physics.
    Path Integrals in Quantum Mechanics and Low-Dimensional QFT2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The focus of this thesis is to introduce the path integral and some of its applications. One interpretation of quantum mechanics is that a microscopic system which moves from an initial- to a final state moves through each possible intermediate state. The path integral uses the principle of least action to sum over all such intermediate states to find the evolution of a quantum mechanical system. We compare the path integral approach to that of the Schrödinger equation and show that the two give an equivalent description of quantum mechanics.

    To demonstrate the usefulness of the path integral, we introduce low-dimensional quantum field theory (QFT). In particular, we discuss Feynman diagrams. The idea behind Feynman diagrams is to sum over all possible weak interactions between fields to evaluate the properties of a system through the path integral. We also carry out a computation of a low energy effective action in a 0-dimensional model. The result of the computation shows that there is free energy also in a vacuum. Finally, we briefly generalize some of the previous discussion to 1-dimensional QFT. To give an example of a practical application, we give a qualitative discussion of how the path integral can be applied to statistical mechanics to predict the behaviour of superfluids.

    Download full text (pdf)
    fulltext
  • 32.
    Adeel, Muhammad
    et al.
    Department of Molecular Sciences and Nanosystems, Ca’Foscari University of Venice, 30172, Venice-Mestre, Italy. Pathology Unit, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, 33081, Aviano, Italy.
    Canzonieri, Vincenzo
    Pathology Unit, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, 33081, Aviano, Italy. Department of Medical, Surgical and Health Sciences, University of Trieste, 34127, Trieste, Italy.
    Daniele, Salvatore
    Department of Molecular Sciences and Nanosystems, Ca’Foscari University of Venice, 30172, Venice-Mestre, Italy.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Molecular Sciences and Nanosystems, Ca’Foscari University of Venice, 30172, Venice-Mestre, Italy.
    Rizzolio, Flavio
    Department of Molecular Sciences and Nanosystems, Ca’Foscari University of Venice, 30172, Venice-Mestre, Italy. Pathology Unit, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, 33081, Aviano, Italy.
    Rahman, Md. Mahbubur
    Department of Energy and Materials, Konkuk University, Chungju, 27478, Republic of Korea.
    2D metal azolate framework as nanozyme for amperometric detection of glucose at physiological pH and alkaline medium2021In: Microchimica Acta, ISSN 0026-3672, E-ISSN 1436-5073, Vol. 188, no 3, article id 77Article in journal (Refereed)
    Abstract [en]

    The synthesis of Co-based two-dimensional (2D) metal azolate framework nanosheets (MAF-5-CoII NS) is described using a simple hydrothermal method. The product was isostructural to MAF-5 (Zn). The as-prepared MAF-5-CoII NS exhibited high surface area (1155 m2/g), purity, and crystallinity. The MAF-5-CoII NS–modified screen-printed electrode (MAF-5-CoII NS/SPE) was used for nonenzymatic detection of glucose in diluted human blood plasma (BP) samples with phosphate buffer saline (PBS, pH 7.4) and NaOH (0.1 M, pH 13.0) solutions. The MAF-5-CoII NS nanozyme displayed good redox activity in both neutral and alkaline media with the formation of CoII/CoIII redox pair, which induced the catalytic oxidation of glucose. Under the optimized detection potential, the sensor presented a chronoamperometric current response for the oxidation of glucose with two wide concentration ranges in PBS-diluted (62.80 to 180 μM and 305 to 8055 μM) and NaOH-diluted (58.90 to 117.6 μM and 180 to 10,055 μM) BP samples, which were within the limit of blood glucose levels of diabetic patients before (4.4–7.2 mM) and after (10 mM) meals (recommended by the American Diabetes Association). The sensor has a limit of detection of ca. 0.25 and 0.05 μM, respectively, and maximum sensitivity of ca. 36.55 and 1361.65 mA/cm2/mM, respectively, in PBS- and NaOH-diluted BP samples. The sensor also displayed excellent stability in the neutral and alkaline media due to the existence of hydrophobic linkers (2-ethyl imidazole) in the MAF-5-CoII NS, good repeatability and reproducibility, and interference-free signals. Thus, MAF-5-CoII NS is a promising nanozyme for the development of the disposable type of sensor for glucose detection in human body fluids.

  • 33.
    Adenier, Guillaume
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Mathematics.
    Khrennikov, Andrei
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Mathematics.
    Is the fair sampling assumption supported by EPR experiments?2007In: Journal of Physics B: At. Mol. Opt. Phys., ISSN 0953-4075, Vol. 40, no 1, p. 131-141Article in journal (Refereed)
    Abstract [en]

    We analyse optical EPR experimental data performed by Weihs et al in Innsbruck 1997–1998. We show that for some linear combinations of the raw coincidence rates, the experimental results display some anomalous behaviour that a more general source state (like non-maximally entangled state) cannot straightforwardly account for. We attempt to explain these anomalies by taking account of the relative efficiencies of the four channels. For this purpose, we use the fair sampling assumption, and assume explicitly that the detection efficiencies for the pairs of entangled photons can be written as a product of the two corresponding detection efficiencies for the single photons. We show that this explicit use of fair sampling cannot be maintained to be a reasonable assumption as it leads to an apparent violation of the no-signalling principle.

  • 34.
    Adjeiwaah, Mary
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Quality assurance for magnetic resonance imaging (MRI) in radiotherapy2017Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Magnetic resonance imaging (MRI) utilizes the magnetic properties of tissues to generate image-forming signals. MRI has exquisite soft-tissue contrast and since tumors are mainly soft-tissues, it offers improved delineation of the target volume and nearby organs at risk. The proposed Magnetic Resonance-only Radiotherapy (MR-only RT) work flow allows for the use of MRI as the sole imaging modality in the radiotherapy (RT) treatment planning of cancer. There are, however, issues with geometric distortions inherent with MR image acquisition processes. These distortions result from imperfections in the main magnetic field, nonlinear gradients, as well as field disturbances introduced by the imaged object. In this thesis, we quantified the effect of system related and patient-induced susceptibility geometric distortions on dose distributions for prostate as well as head and neck cancers. Methods to mitigate these distortions were also studied.

    In Study I, mean worst system related residual distortions of 3.19, 2.52 and 2.08 mm at bandwidths (BW) of 122, 244 and 488 Hz/pixel up to a radial distance of 25 cm from a 3T PET/MR scanner was measured with a large field of view (FoV) phantom. Subsequently, we estimated maximum shifts of 5.8, 2.9 and 1.5 mm due to patient-induced susceptibility distortions. VMAT-optimized treatment plans initially performed on distorted CT (dCT) images and recalculated on real CT datasets resulted in a dose difference of less than 0.5%.

     The magnetic susceptibility differences at tissue-metallic,-air and -bone interfaces result in local B0 magnetic field inhomogeneities. The distortion shifts caused by these field inhomogeneities can be reduced by shimming.  Study II aimed to investigate the use of shimming to improve the homogeneity of local  B0 magnetic field which will be beneficial for radiotherapy applications. A shimming simulation based on spherical harmonics modeling was developed. The spinal cord, an organ at risk is surrounded by bone and in close proximity to the lungs may have high susceptibility differences. In this region, mean pixel shifts caused by local B0 field inhomogeneities were reduced from 3.47±1.22 mm to 1.35±0.44 mm and 0.99±0.30 mm using first and second order shimming respectively. This was for a bandwidth of 122 Hz/pixel and an in-plane voxel size of 1×1 mm2.  Also examined in Study II as in Study I was the dosimetric effect of geometric distortions on 21 Head and Neck cancer treatment plans. The dose difference in D50 at the PTV between distorted CT and real CT plans was less than 1.0%.

    In conclusion, the effect of MR geometric distortions on dose plans was small. Generally, we found patient-induced susceptibility distortions were larger compared with residual system distortions at all delineated structures except the external contour. This information will be relevant when setting margins for treatment volumes and organs at risk.  

    The current practice of characterizing MR geometric distortions utilizing spatial accuracy phantoms alone may not be enough for an MR-only radiotherapy workflow. Therefore, measures to mitigate patient-induced susceptibility effects in clinical practice such as patient-specific correction algorithms are needed to complement existing distortion reduction methods such as high acquisition bandwidth and shimming.

    Download full text (pdf)
    fulltext
  • 35.
    Adjeiwaah, Mary
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Garpebring, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Nyholm, Tufve
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Sensitivity analysis of different quality assurance methods for magnetic resonance imaging in radiotherapy2020In: Physics and Imaging in Radiation Oncology, E-ISSN 2405-6316, Vol. 13, p. 21-27Article in journal (Refereed)
    Abstract [en]

    Background and purpose: There are currently no standard quality assurance (QA) methods for magnetic resonance imaging (MRI) in radiotherapy (RT). This work was aimed at evaluating the ability of two QA protocols to detect common events that affect quality of MR images under RT settings.

    Materials and methods: The American College of Radiology (ACR) MRI QA phantom was repeatedly scanned using a flexible coil and action limits for key image quality parameters were derived. Using an exploratory survey, issues that reduce MR image quality were identified. The most commonly occurring events were introduced as provocations to produce MR images with degraded quality. From these images, detection sensitivities of the ACR MRI QA protocol and a commercial geometric accuracy phantom were determined.

    Results: Machine-specific action limits for key image quality parameters set at mean&#xB1;3&#x3C3;" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; display: inline-block; line-height: normal; font-size: 16.2px; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">mean±3σ were comparable with the ACR acceptable values. For the geometric accuracy phantom, provocations from uncorrected gradient nonlinearity effects and a piece of metal in the bore of the scanner resulted in worst distortions of 22.2 mm and 3.4 mm, respectively. The ACR phantom was sensitive to uncorrected signal variations, electric interference and a piece of metal in the bore of the scanner but could not adequately detect individual coil element failures.

    Conclusions: The ACR MRI QA phantom combined with the large field-of-view commercial geometric accuracy phantom were generally sensitive in identifying some common MR image quality issues. The two protocols when combined may provide a tool to monitor the performance of MRI systems in the radiotherapy environment.

    Download full text (pdf)
    fulltext
  • 36.
    Adler, Mark
    et al.
    Brandeis Univ, Dept Math, Waltham, MA 02453 USA..
    Johansson, Kurt
    KTH, School of Engineering Sciences (SCI), Mathematics (Dept.).
    van Moerbeke, Pierre
    Univ Louvain, Dept Math, B-1348 Louvain, Belgium.;Brandeis Univ, Waltham, MA 02453 USA..
    Tilings of Non-convex Polygons, Skew-Young Tableaux and Determinantal Processes2018In: Communications in Mathematical Physics, ISSN 0010-3616, E-ISSN 1432-0916, Vol. 364, no 1, p. 287-342Article in journal (Refereed)
    Abstract [en]

    This paper studies random lozenge tilings of general non-convex polygonal regions. We show that the pairwise interaction of the non-convexities leads asymptotically to new kernels and thus to new statistics for the tiling fluctuations. The precise geometrical figure here consists of a hexagon with cuts along opposite edges. For this model, we take limits when the size of the hexagon and the cuts tend to infinity, while keeping certain geometric data fixed in order to guarantee sufficient interaction between the cuts in the limit. We show in this paper that the kernel for the finite tiling model can be expressed as a multiple integral, where the number of integrations is related to the fixed geometric data above. The limiting kernel is believed to be a universal master kernel.

  • 37.
    Adlmann, Franz A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Gutfreund, P.
    Ankner, J. F.
    Browning, J. F.
    Parizzi, A.
    Vacaliuc, B.
    Halbert, C. E.
    Rich, J. P.
    Dennison, A. J. C.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Wolff, Max
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Towards neutron scattering experiments with sub-millisecond time resolution2015In: Journal of applied crystallography, ISSN 0021-8898, E-ISSN 1600-5767, Vol. 48, p. 220-226Article in journal (Refereed)
    Abstract [en]

    Neutron scattering techniques offer several unique opportunities in materials research. However, most neutron scattering experiments suffer from the limited flux available at current facilities. This limitation becomes even more severe if time-resolved or kinetic experiments are performed. A new method has been developed which overcomes these limitations when a reversible process is studied, without any compromise on resolution or beam intensity. It is demonstrated that, by recording in absolute time the neutron detector events linked to an excitation, information can be resolved on sub-millisecond timescales. Specifically, the concept of the method is demonstrated by neutron reflectivity measurements in time-of-flight mode at the Liquids Reflectometer located at the Spallation Neutron Source, Oak Ridge National Laboratory, Tennessee, USA, combined with in situ rheometry. The opportunities and limitations of this new technique are evaluated by investigations of a micellar polymer solution offering excellent scattering contrast combined with high sensitivity to shear.

  • 38.
    Adlmann, Franz A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Pálsson, Gunnar Karl
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Bilheux, J. C.
    Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN USA..
    Ankner, J. F.
    Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN USA..
    Gutfreund, P.
    Inst Laue Langevin, BP 156, F-38042 Grenoble, France..
    Kawecki, M.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Wolff, Max
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Överlåtaren: a fast way to transfer and orthogonalize two-dimensional off-specular reflectivity data2016In: Journal of applied crystallography, ISSN 0021-8898, E-ISSN 1600-5767, Vol. 49, p. 2091-2099Article in journal (Refereed)
    Abstract [en]

    Reflectivity measurements offer unique opportunities for the study of surfaces and interfaces, and specular reflectometry has become a standard tool in materials science to resolve structures normal to the surface of a thin film. Off-specular scattering, which probes lateral structures, is more difficult to analyse, because the Fourier space being probed is highly anisotropic and the scattering pattern is truncated by the interface. As a result, scattering patterns collected with (especially time-of-flight) neutron reflectometers are difficult to transform into reciprocal space for comparison with model calculations. A program package is presented for a generic two-dimensional transformation of reflectometry data into q space and back. The data are represented on an orthogonal grid, allowing cuts along directions relevant for theoretical modelling. This treatment includes background subtraction as well as a full characterization of the resolution function. The method is optimized for computational performance using repeatable operations and standardized instrument settings.

  • 39. Adoo, N.A.
    et al.
    Nyarko, B.J.B.
    Akaho, E.H.K.
    Alhassan, Erwin
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Agbodemegbe, V.Y.
    Bansah, C.Y.
    Della, R.
    Determination of thermal hydraulic data of GHARR-1 under reactivity insertion transients using the PARET/ANL code2011In: Nuclear Engineering and Design, ISSN 0029-5493, E-ISSN 1872-759X, Vol. 241, p. 5303-5210Article in journal (Refereed)
    Abstract [en]

    The PARET/ANL code has been adapted by the IAEA for testing transient behaviour in research reactors since it provides a coupled thermal hydrodynamic and point kinetics capability for estimating thermalhydraulic margins. A two-channel power peaking profile of the Ghana Research Reactor-1 (GHARR-1) has been developed for the PARET/ANL (Version 7.3; 2007) using the Monte Carlo N-Particle code (MCNP) to determine the thermal hydraulic data for reactivity insertion transients in the range of 2.0×10^−3k/k to 5.5×10^−3k/k. Peak clad and coolant temperatures ranged from 59.18 ◦C to 112.36 ◦C and 42.95 ◦C to 79.42 ◦C respectively. Calculated safety margins (DNBR) satisfied the MNSR thermal hydraulic design criteria for which no boiling occurs in the reactor core. The generated thermal hydraulic data demonstrated a high inherent safety feature of GHARR-1 for which the high negative reactivity feedback of the moderator limits power excursion and consequently the escalation of the clad temperature.

  • 40. Adriani, O.
    et al.
    Barbarino, G. C.
    Bazilevskaya, G. A.
    Bellotti, R.
    Boezio, M.
    Bogomolov, E. A.
    Bongi, M.
    Bonvicini, V.
    Bottai, S.
    Bruno, A.
    Cafagna, F.
    Campana, D.
    Carbone, R.
    Carlson, Per
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics. AlbaNova University Centre, Sweden.
    Casolino, M.
    Castellini, G.
    De Pascale, M. P.
    De Santis, C.
    De Simone, N.
    Di Felice, V.
    Formato, V.
    Galper, A. M.
    Giaccari, U.
    Karelin, A. V.
    Kheymits, M. D.
    Koldashov, S. V.
    Koldobskiy, S.
    Krut'kov, S. Yu.
    Kvashnin, A. N.
    Leonov, A.
    Malakhov, V.
    Marcelli, L.
    Martucci, M.
    Mayorov, A. G.
    Menn, W.
    Mikhailov, V. V.
    Mocchiutti, E.
    Monaco, A.
    Mori, N.
    Munini, Riccardo
    KTH, School of Engineering Sciences (SCI), Physics. INFN, Italy; AlbaNova University Centre, Sweden; University of Trieste, Italy.
    Nikonov, N.
    Osteria, G.
    Papini, P.
    Pearce, Mark
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics. AlbaNova University Centre, Sweden.
    Picozza, P.
    Pizzolotto, C.
    Ricci, M.
    Ricciarini, S. B.
    Rossetto, Laura
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics. AlbaNova University Centre, Sweden.
    Sarkar, R.
    Simon, M.
    Sparvoli, R.
    Spillantini, P.
    Stozhkov, Y. I.
    Vacchi, A.
    Vannuccini, E.
    Vasilyev, G. I.
    Voronov, S. A.
    Wu, Juan
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics. AlbaNova University Centre, Sweden; China University of Geosciences, China .
    Yurkin, Y. T.
    Zampa, G.
    Zampa, N.
    Zverev, V. G.
    The PAMELA Mission: Heralding a new era in precision cosmic ray physics2014In: Physics reports, ISSN 0370-1573, E-ISSN 1873-6270, Vol. 544, no 4, p. 323-370Article, review/survey (Refereed)
    Abstract [en]

    On the 15th of June 2006, the PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) satellite-borne experiment was launched onboard the Russian Resurs-DK1 satellite by a Soyuz rocket from the Baikonur space centre. The satellite was placed in a quasi-polar 70 degrees inclination orbit at an altitude varying between 350 km and 600 km. New results on the antiparticle component of the cosmic radiation were obtained. The positron energy spectrum and positron fraction were measured from 400 MeV up to 200 GeV revealing a positron excess over the predictions of commonly used propagation models. This can be interpreted either as evidence that the propagation models should be revised or in terms of dark matter annihilation or a pulsar contribution. The antiproton spectrum was measured over the energy range from 60 MeV to 350 GeV. The antiproton spectrum is consistent with secondary production and significantly constrains dark matter models. The energy spectra of protons and helium nuclei were measured up to 1.2 TV. The spectral shapes of these two species are different and cannot be described well by a single power law. For the First time the electron spectrum was measured up to 600 GeV complementing the information obtained from the positron data. Nuclear and isotopic composition was obtained with unprecedented precision. The variation of the low energy proton, electron and positron energy spectra was measured from July 2006 until December 2009 accurately sampling the unusual conditions of the most recent solar minimum activity period (2006-2009). Low energy particle spectra were accurately measured also for various solar events that occurred during the PAMELA mission. The Earth's magnetosphere was studied measuring the particle radiation in different regions of the magnetosphere. Energy spectra and composition of sub-cutoff and trapped particles were obtained. For the first time a belt of trapped antiprotons was detected in the South Atlantic Anomaly region. The flux was found to exceed that for galactic cosmic-ray antiprotons by three order of magnitude.

  • 41.
    Afonso, Marco Martins
    et al.
    Univ Porto, Fac Ciencias, Ctr Matemat, Rua Campo Alegre 687, P-4169007 Porto, Portugal..
    Mitra, Dhrubaditya
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Vincenzi, Dario
    Univ Cote dAzur, CNRS, LJAD, F-06100 Nice, France..
    Kazantsev dynamo in turbulent compressible flows2019In: Proceedings of the Royal Society. Mathematical, Physical and Engineering Sciences, ISSN 1364-5021, E-ISSN 1471-2946, Vol. 475, no 2223, article id 20180591Article in journal (Refereed)
    Abstract [en]

    We consider the kinematic fluctuation dynamo problem in a flow that is random, white-in-time, with both solenoidal and potential components. This model is a generalization of the well-studied Kazantsev model. If both the solenoidal and potential parts have the same scaling exponent, then, as the compressibility of the flow increases, the growth rate decreases but remains positive. If the scaling exponents for the solenoidal and potential parts differ, in particular if they correspond to typical Kolmogorov and Burgers values, we again find that an increase in compressibility slows down the growth rate but does not turn it off. The slow down is, however, weaker and the critical magnetic Reynolds number is lower than when both the solenoidal and potential components display the Kolmogorov scaling. Intriguingly, we find that there exist cases, when the potential part is smoother than the solenoidal part, for which an increase in compressibility increases the growth rate. We also find that the critical value of the scaling exponent above which a dynamo is seen is unity irrespective of the compressibility. Finally, we realize that the dimension d = 3 is special, as for all other values of d the critical exponent is higher and depends on the compressibility.

  • 42.
    Aftab, A.
    et al.
    Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia.
    Ismail, Abdul Razak
    Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia.
    Ibupoto, Zafar
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Akeiber, Hussein J.
    Faculty of Mechanical Engineering, Universiti Teknologi Malaysia.
    Malghani, M.G.K.
    Department of Environmental Management and Policy, BUITEMS Quetta, Pakistan.
    Nanoparticles based drilling muds a solution to drill elevated temperature wells: a review2017In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 76, p. 1301-1313Article in journal (Refereed)
    Abstract [en]

    Demand of the oil and gas energy is increasing very drastically. Conventional hydrocarbon reservoirs contain below the sealing cap rock (shale) and easily move towards wellbore are at the depletion stage. Therefore, drilling engineers in collaboration with mud engineers, geologists and geophysicists are looking for innovative materials to drill unconventional hydrocarbons reservoir which are distributed at the basin scale and cannot approach easily. Geo-thermal energy wells and most of unconventional reservoirs are occurred at high pressure high temperature (HPHT) conditions. Conventional micro-macro organic drilling mud additives with heat insulator in nature can minimize efficiency while drilling HPHT wells. Oil-based muds (OBM) are strictly restricted due to high toxic level and poor emulsion stability at HT. However, this review suggests that addition of macro size organic particles and inorganic nanoparticles can enhance rheological performance, reduce filtrate loss volume and improve shale inhibition characteristics of environmental friendly water-based mud (WBM). Despite an impressive amount of experimental work has been done over drilling additives and their effect over rheological and shale inhibition, taking into account their literature review are rare. In addition, there is no review work of the knowledge gained to date. This work will hope fully trigger further development and new research topics in the area of drilling muds system.

  • 43.
    Aftab, Umair
    et al.
    Department of Metallurgy and Materials Engineering, Mehran University of Engineering and Technology, Jamshoro, Sindh, 76080, Pakistan.
    Tahira, Aneela
    Department of Science and Technology, Campus Norrköping, Linköping University, Norrköping, SE-60174, Sweden.
    Gradone, Alessandro
    CNR-IMM, Via Piero Gobetti 101, Bologna, 40129, Italy. Chemistry Department “G.Ciamician”, University of Bologna, Bologna, 40126, Italy.
    Morandi, Vittorio
    CNR-IMM, Via Piero Gobetti 101, Bologna, 40129, Italy.
    Abro, Muhammad Ishaq
    Department of Metallurgy and Materials Engineering, Mehran University of Engineering and Technology, Jamshoro, Sindh, 76080, Pakistan.
    Baloch, Muhammad Moazam
    Department of Metallurgy and Materials Engineering, Mehran University of Engineering and Technology, Jamshoro, Sindh, 76080, Pakistan.
    Bhatti, Adeel Liaquat
    Institute of Physics University of Sindh, Jamshoro, Sindh, 76080, Pakistan.
    Nafady, Ayman
    Department of Chemistry, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Via Torino 155, Venezia, Mestre, 30172, Italy.
    Ibupoto, Zafar Hussain
    Dr. M.A Kazi Institute of Chemistry University of Sindh, Jamshoro, Sindh, 76080 Pakistan.
    Two step synthesis of TiO2–Co3O4 composite for efficient oxygen evolution reaction2021In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 46, no 13, p. 9110-9122Article in journal (Refereed)
    Abstract [en]

    For an active hydrogen gas generation through water dissociation, the sluggish oxygen evolution reaction (OER) kinetics due to large overpotential is a main hindrance. Herein, a simple approach is used to produce composite material based on TiO2/Co3O4 for efficient OER and overpotential is linearly reduced with increasing amount of TiO2. The scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) investigations reveal the wire like morphology of composite materials, formed by the self-assembly of nanoparticles. The titania nanoparticles were homogenously distributed on the larger Co3O4 nanoparticles. The powder x-ray diffraction revealed a tetragonal phase of TiO2 and the cubic phase of Co3O4 in the composite materials. Composite samples with increasing TiO2 content were obtained (18%, 33%, 41% and 65% wt.). Among the composites, cobalt oxide-titanium oxide with the highest TiO2 content (CT-20) possesses the lowest overpotential for OER with a Tafel slope of 60 mV dec−1 and an exchange current density of 2.98 × 10−3A/cm2. The CT-20 is highly durable for 45 h at different current densities of 10, 20 and 30 mA/cm2. Electrochemical impedance spectroscopy (EIS) confirmed the fast charge transport for the CT-20 sample, which potentially accelerated the OER kinetics. These results based on a two-step methodology for the synthesis of TiO2/Co3O4 material can be useful and interesting for various energy storage and energy conversion systems.

  • 44.
    Agback, Axel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Theoretical Physics.
    Aspects of Conformal Field theory2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Quantum field theories are very good at describing the world around us but use complicated computations that cannot always be solved exactly. Introducing conformal symmetry to quantum field theory can reduce this complexity and allow for quite simple calculation in the best case. This report aims to describe the critical part of the Ising model in 2 dimensions using conformal field theory while assuming only some knowledge of quantum mechanics and complex analysis from the reader. This is done by using the book Conformal Field Theory as the source for information about conformal field theory.

    Download full text (pdf)
    fulltext
  • 45.
    Ageev, Dmitry S.
    et al.
    Russian Acad Sci, Steklov Math Inst, Gubkin St 8, Moscow 119991, Russia.
    Bagrov, Andrey A.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Ural Fed Univ, Theoret Phys & Appl Math Dept, Mira Str 19, Ekaterinburg 620002, Russia.
    Iliasov, Askar A.
    Radboud Univ Nijmegen, Inst Mol & Mat, Heyendaalseweg 135, NL-6525 AJ Nijmegen, Netherlands; Russian Acad Sci, Space Res Inst, Moscow 117997, Russia.
    Deterministic chaos and fractal entropy scaling in Floquet conformal field theories2021In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 103, no 10, article id L100302Article in journal (Refereed)
    Abstract [en]

    In this Letter, we study two-dimensional Floquet conformal field theory, where the external periodic driving is described by iterated logistic or tent maps. These maps are known to be typical examples of dynamical systems exhibiting the order-chaos transition, and we show that, as a result of such driving, the entanglement entropy scaling develops fractal features when the corresponding dynamical system approaches the chaotic regime. For the driving set by the logistic map, the fractal contribution to the scaling dominates, making entanglement entropy a highly oscillating function of the subsystem size.

    Download full text (pdf)
    FULLTEXT01
  • 46.
    Agrawal, Vipin
    et al.
    Nordita SU; Stockholm Univ, Roslagstullsbacken 23, S-10691 Stockholm, Sweden.;Stockholm Univ, Dept Phys, S-10691 Stockholm, Sweden..
    Mitra, Dhrubaditya
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Chaos and irreversibility of a flexible filament in periodically driven Stokes flow2022In: Physical review. E, ISSN 2470-0045, E-ISSN 2470-0053, Vol. 106, no 2, article id 025103Article in journal (Refereed)
    Abstract [en]

    The flow of Newtonian fluid at low Reynolds number is, in general, regular and time-reversible due to absence of nonlinear effects. For example, if the fluid is sheared by its boundary motion that is subsequently reversed, then all the fluid elements return to their initial positions. Consequently, mixing in microchannels happens solely due to molecular diffusion and is very slow. Here, we show, numerically, that the introduction of a single, freely floating, flexible filament in a time-periodic linear shear flow can break reversibility and give rise to chaos due to elastic nonlinearities, if the bending rigidity of the filament is within a carefully chosen range. Within this range, not only the shape of the filament is spatiotemporally chaotic, but also the flow is an efficient mixer. Overall, we find five dynamical phases: the shape of a stiff filament is time-invariant-either straight or buckled; it undergoes a period-two bifurcation as the filament is made softer; becomes spatiotemporally chaotic for even softer filaments but, surprisingly, the chaos is suppressed if bending rigidity is decreased further.

  • 47.
    Agrawal, Vipin
    et al.
    Stockholm University, Nordic Institute for Theoretical Physics (Nordita). Stockholm University, Faculty of Science, Department of Physics.
    Pandey, Vikash
    Stockholm University, Nordic Institute for Theoretical Physics (Nordita).
    Mitra, Dhrubaditya
    Stockholm University, Nordic Institute for Theoretical Physics (Nordita).
    Active buckling of pressurized spherical shells: Monte Carlo simulation2023In: Physical review. E, ISSN 2470-0045, E-ISSN 2470-0053, Vol. 108, no 3, article id L032601Article in journal (Refereed)
    Abstract [en]

    We study the buckling of pressurized spherical shells by Monte Carlo simulations in which the detailed balance is explicitly broken—thereby driving the shell to be active, out of thermal equilibrium. Such a shell typically has either higher (active) or lower (sedate) fluctuations compared to one in thermal equilibrium depending on how the detailed balance is broken. We show that, for the same set of elastic parameters, a shell that is not buckled in thermal equilibrium can be buckled if turned active. Similarly a shell that is buckled in thermal equilibrium can unbuckle if sedated. Based on this result, we suggest that it is possible to experimentally design microscopic elastic shells whose buckling can be optically controlled.

  • 48.
    Aguilar, Edgar A.
    et al.
    Univ Gdansk, Poland.
    Farkas, Mate
    Univ Gdansk, Poland.
    Martinez, Daniel
    Univ Concepcion, Chile.
    Alvarado, Matias
    Univ Concepcion, Chile.
    Carine, Jaime
    Univ Concepcion, Chile.
    Xavier, Guilherme B
    Linköping University, Department of Electrical Engineering, Information Coding. Linköping University, Faculty of Science & Engineering. Univ Concepcion, Chile.
    Barra, Johanna F.
    Univ Concepcion, Chile.
    Canas, Gustavo
    Univ Bio Bio, Chile.
    Pawlowski, Marcin
    Univ Gdansk, Poland.
    Lima, Gustavo
    Univ Concepcion, Chile.
    Certifying an Irreducible 1024-Dimensional Photonic State Using Refined Dimension Witnesses2018In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 120, no 23, article id 230503Article in journal (Refereed)
    Abstract [en]

    We report on a new class of dimension witnesses, based on quantum random access codes, which are a function of the recorded statistics and that have different bounds for all possible decompositions of a high-dimensional physical system. Thus, it certifies the dimension of the system and has the new distinct feature of identifying whether the high-dimensional system is decomposable in terms of lower dimensional subsystems. To demonstrate the practicability of this technique, we used it to experimentally certify the generation of an irreducible 1024-dimensional photonic quantum state. Therefore, certifying that the state is not multipartite or encoded using noncoupled different degrees of freedom of a single photon. Our protocol should find applications in a broad class of modern quantum information experiments addressing the generation of high-dimensional quantum systems, where quantum tomography may become intractable.

    Download full text (pdf)
    fulltext
  • 49.
    Agvik, Simon
    Umeå University, Faculty of Science and Technology, Department of Physics.
    A deformable terrain model in multi-domain dynamics using elastoplastic constraints: An adaptive approach2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Achieving realistic simulations of terrain vehicles in their work environment does not only require a careful model of the vehicle itself but the vehicle's interactions with the surroundings are equally important. For off-road ground vehicles the terrain will heavily affect the behaviour of the vehicle and thus puts great demands on the terrain model.

    The purpose of this project has been to develop and evaluate a deformable terrain model, meant to be used in real-time simulations with multi-body dynamics. The proposed approach is a modification of an existing elastoplastic model based on linear elasticity theory and a capped Drucker-Prager model, using it in an adaptive way. The original model can be seen as a system of rigid bodies connected by elastoplastic constraints, representing the terrain. This project investigates if it is possible to create dynamic bodies just when it is absolutely necessary, and store information about possible deformations in a grid.

    Two methods used for transferring information between the dynamic bodies and the grid have been evaluated; an interpolating approach and a discrete approach. The test results indicate that the interpolating approach is preferable, with better stability to an equal performance cost. However, stability problems still exist that have to be solved if the model should be useful in a commercial product.

    Download full text (pdf)
    fulltext
  • 50. Ahari, Mostafa Tanhayi
    et al.
    Bandyopadhyay, Sumanta
    Stockholm University, Nordic Institute for Theoretical Physics (Nordita). Washington University in St. Louis, USA.
    Nussinov, Zohar
    Seidel, Alexander
    Ortiz, Gerardo
    Partons as unique ground states of quantum Hall parent Hamiltonians: The case of Fibonacci anyons2023In: SciPost Physics, E-ISSN 2542-4653, Vol. 15, no 2, article id 043Article in journal (Refereed)
    Abstract [en]

    We present microscopic, multiple Landau level, (frustration-free and positive semi-definite) parent Hamiltonians whose ground states, realizing different quantum Hall fluids, are parton-like and whose excitations display either Abelian or non-Abelian braiding statistics. We prove ground state energy monotonicity theorems for systems with different particle numbers in multiple Landau levels, demonstrate S-duality in the case of toroidal geometry, and establish complete sets of zero modes of special Hamiltonians stabilizing parton-like states, specifically at filling factor ν=2/3. The emergent Entangled Pauli Principle (EPP), introduced in [Phys. Rev. B 98, 161118(R) (2018)] and which defines the "DNA" of the quantum Hall fluid, is behind the exact determination of the topological characteristics of the fluid, including charge and braiding statistics of excitations, and effective edge theory descriptions. When the closed-shell condition is satisfied, the densest (i.e., the highest density and lowest total angular momentum) zero-energy mode is a unique parton state. We conjecture that parton-like states generally span the subspace of many-body wave functions with the two-body M-clustering property within any given number of Landau levels, that is, wave functions with Mth-order coincidence plane zeroes and both holomorphic and anti-holomorphic dependence on variables. General arguments are supplemented by rigorous considerations for the M=3 case of fermions in four Landau levels. For this case, we establish that the zero mode counting can be done by enumerating certain patterns consistent with an underlying EPP. We apply the coherent state approach of [Phys. Rev. X 1, 021015 (2011)] to show that the elementary (localized) bulk excitations are Fibonacci anyons. This demonstrates that the DNA associated with fractional quantum Hall states encodes all universal properties. Specifically, for parton-like states, we establish a link with tensor network structures of finite bond dimension that emerge via root level entanglement.

1234567 1 - 50 of 4987
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf