Doktorgradsavhandlinger (NT-fak): Recent submissions

Now showing items 221-240 of 312

    • Ice rafting, Ocean circulation and Glacial activity on the western Svalbard margin 0–74 000 years BP 

      Jessen, Simon Pind (Doctoral thesis; Doktorgradsavhandling, 2015-03-27)
      The thesis builds on 11 sediment cores from c. 600 to 1900 m water depth from the continental slope west of Svalbard and one core from the Barents Sea shelf. Together, the cores cover the last 74,000 years. The primary goal was to gain a better insight in ocean circulation and glacial activity in a climatic context on glacial-interglacial and millennial time scales. The main parameters studied are ...

    • On the Generalized Curvature Ocean Surface Scattering Model for the NRCS and Doppler Frequency and its application to ocean surface wind retrieval from Synthetic Aperture Radar data 

      Said, Faozi (Doctoral thesis; Doktorgradsavhandling, 2015-01-23)
      Ocean wind monitoring is an integral part of weather forecasting, maritime shipping lane planning, offshore wind research, as well as the study of climate patterns. Satellite radar instruments, such as Synthetic Aperture Radars (SAR), can help achieve this important task by monitoring the wind conditions over the sea surface. Using specially developed functions, called geophysical model functions, ...

    • Practical synthetic methods for three unstable, unsaturated bromomethyl ketones, and on the use of near-orthogonal experiments for synthetic exploration. 

      Descomps, Alexandre Pierre (Doctoral thesis; Doktorgradsavhandling, 2015-06-18)
      The thesis consists of two different parts: The organic part presents the development of a convenient procedure for the synthesis of three rare, unstable α,β-unsaturated brominated methyl ketones from common commercially available regents. This family of molecule has been very challenging to synthesize and a short history about these efforts as well as different general strategies to produce them ...

    • Structural development and metallogenesis of Paleoproterozoic volcano-sedimentary rocks of the Rombak Tectonic Window 

      Angvik, Tine Larsen (Doctoral thesis; Doktorgradsavhandling, 2014-10-30)
      The Rombaken Tectonic Window (RTW) is a basement culminations within the Caledonian thrust nappes in northern Norway. It appear as an inlier of Paleoproterozoic supracrustal rocks on Paleoproterozoic basement rocks. The RTW consist of several metasedimentary and metavolcanic N-S striking belts enclosed within large granitic bodies. The RTW marks the boundary between Archean basement rocks to the ...

    • HealthTrust: trust-based retrieval of health social media videos 

      Fernandez-Luque, Luis (Doctoral thesis; Doktorgradsavhandling, 2014-10-24)
      There is a global trend towards the use of the Internet to search for information about health issues. We have access to a wide range of online health information; especially the so-called social media (e.g. blogs, videos). However, finding good quality resources is not easy in the current context of information overload. Today, very relevant and valuable health social media has to compete in ...

    • Dynamics and statistical properties of blob structures in scrape-off layer plasmas 

      Kube, Ralph (Doctoral thesis; Doktorgradsavhandling, 2014-12-16)
      The velocity scaling of blobs, subject to dissipation by either electric currents to the sheaths, or dynamical friction, is studied by numerical simulations where the blob amplitude relative to the background plasma is a free parameter. When subject to dissipation by sheath currents, the radial velocity of a blob depends on the square of its cross field size l, vrad ∼ √l for small l. For large l, ...

    • Post-Caledonian brittle faults along the SW Barents Sea Margin: onshore-offshore margin architecture and fault rock-forming conditions 

      Indrevær, Kjetil (Doctoral thesis; Doktorgradsavhandling, 2014-11-13)
      The thesis aims to unravel the evolution and finite stage architecture of the SW Barents Sea Margin, which formed as a part of the rifting of present day Greenland and Scandinavia and the opening of the North Atlantic Ocean (cf. Faleide et al., 2008). The SW Barents Sea Margin studied in this thesis starts just north of the Lofoten-Vesterålen archipelago, continues northward outboard northern ...

    • Analysis and Interpretation of C-band Polarimetric SAR signatures of Sea Ice 

      Moen, Mari-Ann (Doctoral thesis; Doktorgradsavhandling, 2015-01-16)
      Operational sea ice charts are currently produced manually, an inefficient process resulting in subjective ice charts. Hence, there is a need for automating this procedure. This thesis investigates how polarimetric microwave radar signatures relate to the physical properties of sea ice, and how these signatures may contribute to the development of robust automatic algorithms. Our analyses are based ...

    • Characterization of Low Backscatter Regions in the Marine Environment by Multipolarization C- and X-band Synthetic Aperture Radar Data 

      Skrunes, Stine (Doctoral thesis; Doktorgradsavhandling, 2014-10-10)
      The focus of this thesis is the application of multipolarization SAR data for characterization of marine oil spills and other low backscatter ocean phenomena. A variety of SAR descriptors are investigated for the purpose of discriminating between oil spills and look-alikes. The effects of various parameters on the imaging, including sensor frequency, imaging geometry and oil properties, are addressed. ...

    • A multi-proxy approach for reconstructing oceanographic dynamics during the Holocene Development and Application of benthic foraminifera as proxies in the Polar North Atlantic 

      Skirbekk, Kari (Doctoral thesis; Doktorgradsavhandling, 2014-10-23)
      Two sediment cores and several sediment surface samples have been retrieved in order to develop and apply benthic foraminifera as proxies in the Polar North Atlantic. The purpose of the surface samples was to develop the Mg/Ca method for cold water environments, as this has been proven a valuable paleo-thermometer for several marine environments. This was done for three species of Benthic foraminifera: ...

    • Statistical methods for scale-invariant and multifractal stochastic processes. 

      Løvsletten, Ola (Doctoral thesis; Doktorgradsavhandling, 2014-10-03)
      This thesis focuses on stochastic modeling, and statistical methods, in finance and in climate science. Two financial markets, short-term interest rates and electricity prices, are analyzed. We find that the evidence of mean reversion in short-term interest rates is week, while the “log-returns” of electricity prices have significant anti-correlations. More importantly, empirical analyses confirm ...

    • Multi-Locality Based Local and Symbiotic Computing for Interactively fast On-Demand Weather Forecasting for Small Regions, Short Durations, and Very High-Resolutions 

      Fjukstad, Bård (Doctoral thesis; Doktorgradsavhandling, 2014-09-19)
      Modern weather forecasting is based on forecasts from huge numerical models executed on large supercomputer clusters in large computer centers. Production deadlines for forecast and available computational resources are the main factors for having to limit the forecast region size, spatial resolution, forecast duration and detail level of the weather model used. Modern numerical models currently ...

    • A Holocene palaeoceanographic multi-proxy study on the variability of Atlantic water inflow and sea ice distribution along the pathway of Atlantic water 

      Berben, Sarah (Doctoral thesis; Doktorgradsavhandling, 2014-10-14)
      The aim of this PhD thesis is to deliver improved quantitative reconstructions of sub-surface temperatures, salinities and seasonal sea ice distribution. Additionally, the natural variability of Atlantic water inflow and seasonal sea ice distribution and possible forcing mechanisms such as solar insolation, atmospheric circulation patterns (e.g. North Atlantic Oscillation (NAO)) and atmosphere-sea ...

    • Environmental response to past and recent climate variability in the Trondheimsfjord region, central Norway - A multiproxy geochemical approach 

      Faust, Johan Christoph (Doctoral thesis; Doktorgradsavhandling, 2014-07-04)
      Norwegian fjords have a great potential for providing high-resolution sedimentary records that reflect local terrestrial and marine processes and therefore, fjords offer unique opportunities for the investigation of sedimentological and geochemical climatically induced processes. However, the complexity of fjord systems in terms of bathymetry and oceanography requires a profound knowledge of the ...

    • Paleoceanography of the NE North Atlantic during the Holocene 

      Groot, Diane (Doctoral thesis; Doktorgradsavhandling, 2014-09-26)
      This thesis aimed at enhancing our understanding of the oceanographic variability of the Nordic Seas during the last 11,000 years. The Nordic Seas are a key area within the Atlantic Meridional Overturning Circulation (AMOC), a process which helps to maintain the present mild climate of northwestern Europe through its meridional heat transport and plays an important role in global heat distribution. ...

    • Complex Network Structure Patterns in Open Internet Communities for People with Diabetes 

      Chomutare, Taridzo Fred (Doctoral thesis; Doktorgradsavhandling, 2014-05-14)
      Type 2 diabetes is one of the greatest challenges that continues to grow because of the ageing population, increasing morbid obesity and sedentary lifestyles. Social media such as Facebook and YouTube have transformed the way people interact in general and on the Internet, but the role of social media in healthcare is still not well-understood. Current understanding of the association between ...

    • Sedimentary processes, late Cenozoic evolution and sediment yield on the continental margin offshore Troms, northern Norway 

      Rydningen, Tom Arne (Doctoral thesis; Doktorgradsavhandling, 2014-06-19)

    • Long Range Memory in Time Series of Earth Surface Temperature 

      Østvand, Lene (Doctoral thesis; Doktorgradsavhandling, 2014-05-23)
      Long-range memory (LRM) has been found in numerous natural data records, both in geophysics and other fields. In this thesis LRM in surface temperature time series is studied, and comparison with short-range memory (SRM) models performed. Trends are important in climate studies, but the trend definition is ambiguous. Two different approaches are included here: the trend described as a function ...

    • Associations of pulmonary parameters with accelerometer data 

      Dias, André (Doctoral thesis; Doktorgradsavhandling, 2014-03-25)
      In Europe it is estimated that the number of elderly people aged above 65 will have doubled by 2060. In several chronic pulmonary diseases patients can suffer recurrent exacerbation episodes that can lead to severe breathing or death. In this thesis we explore the association of physical activity to lung health parameters, focusing on cystic fibrosis and chronic obstructive pulmonary disease ...

    • Sub-seabed fluid-flow systems and gas hydrates of the SW Barents Sea and North Sea margins 

      Vadakkepuliyambatta, Sunil (Doctoral thesis; Doktorgradsavhandling, 2014-04-25)
      Denne avhandlingen omfatter studier av utbredelse og evolusjon av fluid migrasjonssystemer og gasshydrater i SV Barentshavet og nordlige Nordsjøen. Avhandlingen er basert på tolkning av seismiske og brønndata og numerisk modelling av hydratstabiliteten. Store fluid lekkasjestrukturer forekommer i SV Barentshavet og viser kobling mot de store tektoniske forkastningssytemene. Det er trolig istidene ...