Viser treff 2956-2975 av 4753

    • The occurrence of flow transformations within sandy submarine fans: A case study from the Eocene on Spitsbergen 

      Broze, Elliot Alessandro (Master thesis; Mastergradsoppgave, 2017-05-15)
      The Van Keulenfjorden transect on Spitsbergen offers valuable insight into submarine processes, with well exposed seismic scale clinoforms of Paleocene and Eocene age, which show the distribution of sediments from deltaic to basin floor environments. Several progradational submarine fans are preserved as cliffs on Hyrnestabben. They serve as an analogues to coarse grained submarine fans in provinces ...
    • Ocean Applications 

      Migliaccio, M.; Nunziata, F.; Marino, A.D.; Brekke, Camilla; Skrunes, Stine (Chapter; Bokkapittel, 2021-05-11)
      In this chapter, the most promising techniques to observe oil slicks and to detect metallic targets at sea using polarimetric synthetic aperture radar (SAR) data are reviewed and critically analysed. The detection of oil slicks in SAR data is made difficult not only by the presence of speckle but also by the presence of, e.g. biogenic films, low-wind areas, rain cells, currents, etc., which increase ...
    • Ocean modeling in Northern Norway: A tidal verification study 

      Djuve, Hans Kristian (Master thesis; Mastergradsoppgave, 2014-06-02)
      The coast of Northern Norway has for the first time been modeled using an unstructured grid. The modeling is done using two separate grids of different resolution, and the model data is compared to measurements done along the coast to verify its performance for both the fine and coarse grid. The model is a 2-D depth integrated model of tidal circulation with bottom friction. The data have been ...
    • Ocean temperature variability for the past 60 years on the Norwegian-Svalbard margin influences gas hydrate stability on human time scales 

      Ferré, Benedicte; Mienert, Jurgen; Feseker, Tomas (Journal article; Tidsskriftartikkel; Peer reviewed, 2012-10-23)
      The potential impact of future climate change on methane release from oceanic gas hydrates is the subject of much debate. We analyzed World Ocean Database quality controlled data on the Norwegian‐Svalbard continental margin from the past 60 years to evaluate the potential effect of ocean temperature variations on continental margin gas hydrate reservoirs. Bottom water temperatures in the Norwegian‐Svalbard ...
    • Oceanographic variability and change in two fjords in northern Norway 

      Bjørndalen, Elena (Mastergradsoppgave; Master thesis, 2023-06-01)
      Long-term hydrographic time series data from two fixed stations in the northern Norwegian fjords Malangen and Balsfjorden from the period 1980 - 2022 have been examined. The data have been supplemented with model results from the ocean model NorFjords160 over the period April 1st 2017 to December 31st 2022. To gain a deeper understanding of the oceanographic variability and change, the environmental ...
    • Octaiodoporphyrin and Octaiodocorrole: Isolation of a Cis Porphyrin Tautomer 

      Thomassen, Ivar Kristian (Doctoral thesis; Doktorgradsavhandling, 2018-09-28)
      Iodinated aromatics are excellent starting materials for further elaboration via transition-metal-catalyzed cross-coupling reactions. Considering the diverse applications of porphyrins and corroles - as photosensitizers in photodynamic therapy, dye sensitized solar cells, near-infrared dyes, gas sensors, nonlinear optical materials, and catalysts - the synthetic potential of β-polyiodinated or ...
    • ODEs whose Symmetry Groups are not Fiber-Preserving 

      Kruglikov, Boris Serafimovich; Schneider, Eivind (Journal article; Tidsskriftartikkel; Peer reviewed, 2023)
      We observe that, up to conjugation, a majority of higher order ODEs (ordinary differential equations) and ODE systems have only fiber-preserving point symmetries. By exploiting Lie's classification of Lie algebras of vector fields, we describe all exceptions to this in the case of scalar ODEs and systems of ODEs on a pair of functions. The scalar ODEs whose symmetry algebras are not fiber preserving ...
    • Offshore permafrost decay and massive seabed methane escape in water depths >20 m at the South Kara Sea shelf 

      Portnov, Alexey; Mienert, Jurgen; Cherkashov, Georgy; Rekant, Pavel; Semenov, Peter; Serov, Pavel; Vanshtein, Boris; Smith, Andrew James (Journal article; Tidsskriftartikkel; Peer reviewed, 2013-07-14)
      Since the Last Glacial Maximum (~19 ka), coastal inundation from sea-level rise has been thawing thick subsea permafrost across the Arctic. Although subsea permafrost has been mapped on several Arctic continental shelves, permafrost distribution in the South Kara Sea and the extent to which it is acting as an impermeable seal to seabed methane escape remains poorly understood. Here we use >1300 km ...
    • Oil Spill Analysis Using Hybrid-Polarization Synthetic Aperture Radar 

      Høifødt, Audun Leonard (Master thesis; Mastergradsoppgave, 2016-06-01)
      The goal for this thesis is to test various Hybrid-Polarization (HP) Synthetic Aperture Radar (SAR) parameters using actual HP data, and to evaluate the validity of these parameters with respect to oil slick detection. As part of the evaluation, the impact of the system noise and incidence angle on the SAR images is discussed. It is shown that the Signal-to-Noise Ratio (SNR) of the sensor has a ...
    • Oil Spill Behavior and Response in the Arctic. Risk Analysis of Existing Response Methods Applicable for the Arctic Conditions 

      Zhelezniak, Viktoriia (Master thesis; Mastergradsoppgave, 2021-06-01)
      Due to the demand for diversifying and modifying sources of raw materials and trade routes, the Arctic is the region of high interests. Development and carrying out the offshore activities associated with oil and gas industry and maritime transport are growing rapidly in the Arctic. However, an acute problem associated with the development of offshore activities is the ecological consequence caused ...
    • Oil spill characterization in the hybrid-polarity SAR domain using log-cumulants 

      Espeseth, Martine; Skrunes, Stine; Brekke, Camilla; Salberg, Arnt Børre; Jones, Cathleen; Holt, Benjamin (Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-10-18)
      Log-cumulants have proven to be an interesting tool for evaluating the statistical properties of potential oil spills in polarimetric Synthetic Aperture Radar (SAR) data within the common horizontal (H) and vertical (V) polarization basis. The use of first, second, and third order sample log-cumulants has shown potential for evaluating the texture and the statistical distributions, as well as ...
    • Oil Spill Dispersion in Full-polarimetric and Hybrid-polarity SAR 

      Brekke, Camilla; Skrunes, Stine; Espeseth, Martine (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-04)
      We show that indications of spatial dispersion effects on mineral oil slicks are observed by space-borne multipolarization synthetic aperture radar. This is readily perceived by eye when correlating multipolarization synthetic aperture radar observables with the ship track of the dispersion vessel. We investigate real full-polarimetric (linear transmit/linear receive) as well as simulated and real ...
    • Oil spill emergency preparedness in the Russian Arctic : a study of the Murmansk region. 

      Ivanova, Maria (Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
      The issue of oil spill emergency response in north-west Russia has become increasingly important following a substantial increase in maritime transport and major offshore developments in Russian waters. This study is an initial effort to outline the public and private agencies and organizations involved in handling oil spills in the Murmansk region and the structure of the oil spill emergency response ...
    • Oil Spill Preparedness and Response in the Arctic. The effect of low temperature on oil spill response operations in the Arctic with respect to overall equipment effectiveness 

      Rolandsen, Markus Helfjord (Master thesis; Mastergradsoppgave, 2018-06-02)
      Effectiveness is an important term in oil spill response operations. Literature often relate to the level of effectiveness connected to either mechanical containment and recovery, in-situ burning or chemical dispersant application. The term effectiveness in oil spill response operations can be related to existing theory and the perspective of Overall Equipment Effectiveness (OEE). The perspective ...
    • Oil-Spill-Response-Oriented Information Products Derived From a Rapid-Repeat Time Series of SAR Images 

      Espeseth, Martine; Jones, Cathleen; Benjamin, Holt; Brekke, Camilla; Skrunes, Stine (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-19)
      New quantitative and semiautomated methods for analyzing oil slick evolution using a time series of L-band synthetic aperture radar (SAR) images with short repeat time are developed and explored. In this study, two methods that are complementary in terms of identifying temporal changes within an oil slick are presented. The two methods reflect two ways of evaluating the oil slicks. The first method ...
    • The Omni-Kernel Architecture: Scheduler Control Over All Resource Consumption in Multi-Core Computing Systems 

      Kvalnes, Åge Andre (Doctoral thesis; Doktorgradsavhandling, 2014-03-13)
      Clouds commonly employ virtual machine technology to leverage and efficiently utilize computational resources in data centers. The workloads encapsulated by virtual machines contend for the resources of their hosting machines and interference from resource sharing can cause unpredictable performance. Despite the use of virtual machine technology, the role of the operating system as an arbiter of ...
    • Omni-Kernel: An Operating System Architecture for Pervasive Monitoring and Scheduling 

      Kvalnes, Åge; Johansen, Dag; Renesse, Robbert van; Schneider, Fred B.; Valvåg, Steffen (Research report; Forskningsrapport, 2013)
      Clouds commonly employ virtual machine technology to leverage and efficiently utilize computational resources in data centers. The workloads encapsulated by virtual machines contend for the resources of their hosting machines, and interference from resource sharing can cause unpredictable performance. Despite the use of virtual machine technology, the role of the operating system as an arbiter of ...
    • On a class of integrable systems of Monge-Ampère type 

      Doubrov, Boris; Ferapontov, Eugene V.; Kruglikov, Boris; Novikov, Vladimir S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-08)
      We investigate a class of multi-dimensional two-component systems of Monge-Ampère type that can be viewed as generalisations of heavenly type equations appearing in a self-dual Ricci-flat geometry. Based on the Jordan-Kronecker theory of the skew-symmetric matrix pencils, a classification of normal forms of such systems is obtained. All two-component systems of Monge-Ampère type turn out to be ...
    • On a class of linearizable planar geodesic webs 

      Goldberg, Vladislav V.; Lychagin, Valentin V. (Working paper; Arbeidsnotat, 2008-12-13)
      We present a complete description of a class of linearizable planar geodesic webs which contain a parallelizable 3-subweb.
    • On Atmospheric Energy Transport by Waves 

      Heiskanen, Tuomas Ilkka Henrikki (Master thesis; Mastergradsoppgave, 2018-12-14)
      Recently a new method, based on a Fourier decomposition in the zonal direction, for studying the atmospheric energy transport contribution by planetary and cyclone scale waves has been proposed. Recent studies based on this show that planetary waves contribute more than cyclone scale waves to the atmospheric energy transport into the Arctic. The planetary waves contribute to the Arctic amplification ...