Now showing items 1-20 of 538

    • A Nonlinear Differential Equation Solver With Potential Application to Pelton Turbines 

      Tveit, Jesper (The University of Bergen, 2016-05-02)
      The focus in this thesis is the development and implementation of a new method for solving nonlinear differential equations on a grid. The method’s novelty lies in the way it represents continuously distributed variables ...
      Doctoral thesis
    • Ground-based and Satellite Remote Sensing of Atmospheric Aerosols and Ultraviolet Solar Radiation 

      Muyimbwa, Dennis (The University of Bergen, 2016-04-08)
      Satellite remote sensed data have been used to determine the aerosol climatology and to investigate the influence of the aerosol index (AI) on the ultraviolet (UV) index in coastal land areas in Serrekunda (13.28◦ N, 16.34◦ ...
      Doctoral thesis
    • Enhanced Oil Recovery by CO2 Injection in Fractured Reservoirs. Emphasis on Wettability and Water Saturation 

      Steinsbø, Marianne (The University of Bergen, 2016-03-04)
      The work presented in this Thesis is part of ongoing research on Enhanced Oil Recovery (EOR) in fractured reservoirs within the reservoir physics research group at the Department of Physics and Technology, University of ...
      Doctoral thesis
    • Investigations into the impact of solid surfaces in aqueous systems 

      Jensen, Bjørnar (The University of Bergen, 2016-03-03)
      Global warming is upon us. The scientific community is searching for methods of slowing down, preventing and reversing its effects. Carbon dioxide have been at the center of attention the last few decades, being the main ...
      Doctoral thesis
    • A new population of terrestrial gamma-ray flashes in the RHESSI data 

      Østgaard, Nikolai; Albrechtsen, Kjetil; Gjesteland, Thomas; Collier, Andrew B. (AGU Publications, 2015-12-23)
      Terrestrial gamma-ray flashes (TGFs) are the most energetic photon phenomenon occurring naturally on Earth. An outstanding question is as follows: Are these flashes just a rare exotic phenomenon or are they an intrinsic ...
      Journal article
    • Visualization and interpretation of methane hydrate growth and dissociation in synthetic porous media 

      Flatlandsmo, Josef (The University of Bergen, 2015-12-22)
      Sedimentary natural gas hydrates might play an important role in the future energy mix and the impact of methane release from natural gas hydrates can be significant also with respect to climate change. Vast amounts of ...
      Master thesis
    • Radiation treatment monitoring using multimodal functional imaging: PET/CT (18F-Fluoromisonidazole & 18F-Fluorocholine) and DCE-US 

      Arteaga-Marrero, Natalia; Brekke Rygh, Cecilie; Mainou-Gomez, Jose Francisco; Adamsen, Tom Christian; Lutay, Nataliya; Reed, Rolf K; Olsen, Dag Rune (BioMed Central, 2015-12-18)
      Background: This study aims to assess the effect of radiation treatment on the tumour vasculature and its downstream effects on hypoxia and choline metabolism using a multimodal approach in the murine prostate tumour model ...
      Journal article
    • Observation of intrinsically bright terrestrial gamma ray flashes from the Mediterranean basin 

      Gjesteland, Thomas; Østgaard, Nikolai; Laviola, Sante; Miglietta, M M; Arnone, Enrico; Marisaldi, Martino; Fuschino, F; Collier, Andrew B.; Fabro, F; Montanya, J (AGU Publications, 2015-12-14)
      We present three terrestrial gamma ray flashes (TGFs) observed over the Mediterranean basin by the Reuven Ramaty High Energy Solar Spectroscope Imager (RHESSI) satellite. Since the occurrence of these events in the ...
      Journal article
    • Autonomic Operation of a Large High Performance On-Line Compute Cluster 

      Haaland, Øystein Senneset (The University of Bergen, 2015-12-10)
      A High-Level Trigger (HLT) system is composed of both hardware and software. Designing the physical layout of the cluster mainly concerns the hardware; node distribution, network layout, estimation of power requirements, ...
      Doctoral thesis
    • Investigation of temperature rise in substation during emergency 

      Knutsen, Per Christian (The University of Bergen, 2015-12-08)
      During a TTS verification at Kårstø Processing Plant there where raised a non-conformity to Statoil specification and requirements with regard to temperature rise in substations when HVAC is shut down. One could not ...
      Master thesis
    • Estimation of cold plasma outflow during geomagnetic storms 

      Haaland, Stein; Eriksson, A.; Maes, L.; Baddeley, Lisa; Barakat, A.; Chappell, R.; Eccles, V.; Johnsen, C.; Lybekk, Bjørn; Li, K.; Pedersen, A; Schunk, R.; Welling, D. (Wiley, 2015-12-01)
      Low-energy ions of ionospheric origin constitute a significant contributor to the magnetospheric plasma population. Measuring cold ions is difficult though. Observations have to be done at sufficiently high altitudes and ...
      Journal article
    • In-flight calibration of NOAA POES proton detectors - Derivation of the MEPED correction factors 

      Sandanger, Marit Irene J.; Ødegaard, Linn-Kristine Glesnes; Tyssøy, Hilde Nesse; Stadsnes, Johan; Søraas, Finn; Oksavik, Kjellmar; Aarsnes, Kjell (Wiley, 2015-11-25)
      The MEPED instruments on board the NOAA POES and MetOp satellites have been continuously measuring energetic particles in the magnetosphere since 1978. However, degradation of the proton detectors over time leads to an ...
      Journal article
    • The interaction between transpolar arcs and cusp spots 

      Fear, Robert C.; Milan, Steve; Carter, Jenny A.; Maggiolo, Romain (AGU Publications, 2015-11-25)
      Transpolar arcs and cusp spots are both auroral phenomena which occur when the interplanetary magnetic field is northward. Transpolar arcs are associated with magnetic reconnection in the magnetotail, which closes magnetic ...
      Journal article
    • Solar radiation energy on the Tibetan plateau 

      Gelsor, Nuozhen (The University of Bergen, 2015-11-20)
      To gain a thorough knowledge of the solar energy resources on the Tibetan Plateau, measured and modeled solar irradiance levels on the Plateau from July 2010 to September 2013 are considered. The Tibetan Plateau lies in ...
      Master thesis
    • Reciprocity calibration of ultrasonic piezoelectric disks in air 

      Andersen, Kenneth Kirkeng (The University of Bergen, 2015-11-20)
      The phase response of a transducer acting as a transmitter or receiver of sound is important in many industrial applications, such as fiscal measurements of natural gas, therein multipath ultrasonic transit-time flow meters, ...
      Master thesis
    • A Comparative Study of Radiation Environment and Secondary Dose Production in a Particle Therapy Treatment Room Applying Proton, Helium and Carbon Ion Beams 

      Sølie, Jarle Rambo (The University of Bergen, 2015-11-20)
      A treatment room used for radiotherapy is generally heavily shielded and has to fulfil and abide to strict rules and regulations in order to ensure the safety and health of hospital personnel and the general public that ...
      Master thesis
    • Rydberg Atoms in THz Fields 

      Rørstad, Jørgen Johansen (The University of Bergen, 2015-11-17)
      Rydberg atoms are highly excited atoms with bizarre and exotic properties such as huge orbits and exaggerated sensitivity to fields. In this study we examine these atoms using classical methods. We present the classical ...
      Master thesis
    • Meter-scale spark X-ray spectrum statistics 

      Carlson, Brant Edward; Østgaard, Nikolai; Kochkin, Pavlo; Grøndahl, Øystein; Nisi, Ragnhild Schrøder; Weber, Kristian; Scherrer, Zack; LeCaptain, Kristian (AGU Publications, 2015-11-13)
      X-ray emission by sparks implies bremsstrahlung from a population of energetic electrons, but the details of this process remain a mystery. We present detailed statistical analysis of X-ray spectra detected by multiple ...
      Journal article
    • How the IMF By induces a By component in the closed magnetosphere and how it leads to asymmetric currents and convection patternsin the two hemispheres 

      Tenfjord, Paul; Østgaard, Nikolai; Snekvik, Kristian; Laundal, Karl Magnus; Reistad, Jone Peter; Haaland, Stein; Milan, Steve (Wiley, 2015-11-12)
      We used the Lyon-Fedder-Mobarry global magnetohydrodynamics model to study the effects of the interplanetary magnetic field (IMF) By component on the coupling between the solar wind and magnetosphere-ionosphere system. ...
      Journal article
    • Enhanced detection of terrestrial gamma-ray flashes by AGILE 

      Marisaldi, Martino; Argan, A; Ursi, Alessandro; Gjesteland, Thomas; Fuschino, F; Labanti, C; Galli, M; Tavani, M; Pittori, C; Verrecchia, F; D´Amico, F.; Østgaard, Nikolai; Mereghetti, S; Campana, R; Cattaneo, PW; Bulgarelli, S; Colafrancesco, S; Dietrich, S; Longo, F; Gianotti, F.; Giommi, P; Rappoldi, A; Trifoglio, M; Trois, A (AGU Publications, 2015-11-06)
      At the end of March 2015 the onboard software configuration of the Astrorivelatore Gamma a Immagini Leggero (AGILE) satellite was modified in order to disable the veto signal of the anticoincidence shield for the minicalorimeter ...
      Journal article