Blar i tittel Doktorgradsavhandlinger (NT-fak)

Viser treff 140-159 av 290

    • Marine natural product inspired synthesis towards new antimicrobial and antifouling agents 

      Langer, Manuel Karl (Doctoral thesis; Doktorgradsavhandling, 2022-08-30)
      Natural products (NPs) have been the major source for the development of new small molecule drugs in modern medicine. Despite NPs being so prominent, marine natural products (MNPs) and derivatives thereof are hardly found in clinically approved agents. Therefore, using bioactive MNPs as structural guidance for drug development is a largely untapped source. The focus of the presented thesis is on ...

    • Maritime Target Detection in Non-homogeneous Sea Clutter Environments based on Single- and Multi-polarization Synthetic Aperture Radar Data 

      Tao, Ding (Doctoral thesis; Doktorgradsavhandling, 2015-12-03)
      This thesis discusses the subject of maritime target detection based on single- and multi-polarization synthetic aperture radar (SAR) data. The primary objective is to develop an automatic and effective target detection algorithm, which is able to provide robust performance for an operational maritime surveillance system under various circumstances. There are two frequently encountered major ...

    • Mass-movements on the continental slope offshore Lofoten, Northern Norway 

      Baeten, Nicole Jeanne (Doctoral thesis; Doktorgradsavhandling, 2013-09-20)
      Swath bathymetry, side-scan sonar, sub-bottom profiler and seismic data from the continental slope offshore the Lofoten Islands, northern Norway reveal smaller-scale mass movements in water depths between 1100 and 2500 m. These mass movements have volumes of 0.061 to 8.7 km3 and are interpreted as translational slides involving spreading and multi-phase retrogression. The spatial variation in failure ...

    • Measuring Methane in the Arctic Ocean - From legal framework to time series analysis via technology innovation 

      Dølven, Knut Ola (Doctoral thesis; Doktorgradsavhandling, 2022-03-24)
      <p>Understanding how the earth system interacts with ongoing climate change is important to find a realistic route towards a sustainable future. The impact of Arctic seabed methane seepage on contemporary and future climate is still poorly constrained, described, and quantified. An important limiting factor in our understanding of seabed seepage in the Arctic is a lack of in situ measurements; ...

    • Mechanisms of enzyme adaptation to extreme environments: The rational design of a thermophilic chorismate mutase 

      Wilkins, Ryan Scott (Doctoral thesis; Doktorgradsavhandling, 2024-02-26)
      <p>Extremophiles, especially those living in high-temperature environments, exhibit unique enzymatic mechanisms that allow survival under conditions detrimental to most life forms. Of particular interest is thermophiles, which are able to thrive at temperatures at which psychrophiles and mesophiles unfold and cease to function. The mechanisms by which these enzymes are able to overcome this temperature ...

    • Melanoma detection Colour, clustering and classification 

      Møllersen, Kajsa (Doctoral thesis; Doktorgradsavhandling, 2016-02-19)
      Malignant melanoma is the deadliest form of skin cancer, and successful treatment relies on early detection. Undiagnosed skin lesions can be photographed and the images fed into a computer system that potentially differentiates malignant from benign lesions. To develop the melanoma detection system, various methods from statistics, machine learning and image analysis are applied. An image consists ...

    • Mesospheric Dust - radar applications for detection and investigation 

      Gunnarsdottir, Tinna Lif (Doctoral thesis; Doktorgradsavhandling, 2023-11-15)
      <p>Large amounts of meteoric particles ablate globally into the Earth’s atmosphere each day, and they interact with the atmosphere through several processes in the mesosphere and below. These processes include dust charging, where dust is expected to influence the charge balance in the D-region of the ionosphere. Consequently, the charged dust particles can influence the incoherent scatter that is ...

    • META-pipe – Distributed Pipeline Analysis of Marine Metagenomic Sequence Data 

      Robertsen, Espen Mikal (Doctoral thesis; Doktorgradsavhandling, 2017-05-19)
      With the accelerated advances in sequencing technology the last decade, the field of metagenomics has progressed immensely. Sampling and sequencing of metagenomic data is now prevalent, and publicly available data sets from mundane soil and water environments to exotic niche habitats such as geothermal hot springs are readily available through sequence data repositories such as the European Nucleotide ...

    • Methane bubbles in the Arctic Ocean. Quantification, variability analysis and modelling of free and dissolved methane from the seafloor to the atmosphere 

      Jansson, Pär (Doctoral thesis; Doktorgradsavhandling, 2018-11-09)
      Intensive but heterogeneous and transient seepage of methane (CH4) bubbles from the seafloor exist west of Prins Karls Forland (PKF), offshore western Svalbard. The powerful greenhouse gas CH4, has 32 times higher warming potential than carbon dioxide (CO2) and if seepage of CH4 from the seafloor reaches the atmosphere, it will contribute to the warming climate. Warming of the oceans may in turn, ...

    • Method development towards synthesis of carbapenemase inhibitors 

      Ismael, Aya (Doctoral thesis; Doktorgradsavhandling, 2020-10-26)
      Carbapenemases are enzymes able to hydrolyze the last resort b-lactam antibiotics (carbapenems), which are used for the treatment of infections caused by resistant bacteria. Carbapenemases are structurally and mechanistically classified into serine-b-lactamases (SBLs) and metallo-b-lactamases (MBLs). In order to combat the hydrolytic activity of these enzymes, combination therapy of b-lactam with ...

    • Methods for enhanced learning using wearable technologies. A study of the maritime sector 

      Xue, Hui (Doctoral thesis; Doktorgradsavhandling, 2023-10-04)
      Maritime safety is a critical concern due to the potential for serious consequences or accidents for the crew, passengers, environment, and assets resulting from navigation errors or unsafe acts. Traditional training methods face challenges in the rapidly evolving maritime industry, and innovative training methods are being explored. This study explores the use of wearable sensors with biosignal ...

    • Mid/Late Devonian-Carboniferous extensional faulting in Finnmark and the SW Barents Sea 

      Koehl, Jean-Baptiste Philippe (Doctoral thesis; Doktorgradsavhandling, 2018-05-24)
      In northern Norway, late/post-Caledonian extension initiated along inverted, brittle-ductile thrusts, e.g. Sørøya-Ingøya shear zone, which truncated existing, margin-oblique, late Neoproterozoic, Timanian faults and margin-parallel, latest Mesoproterozoic-mid Neoproterozoic faults related to the opening of the Asgard Sea and Iapetus Ocean. Inverted thrusts were active through the Devonian and early ...

    • Millennial-scale variability of Atlantic water inflow in the northern Nordic Seas and the northwestern Barents Sea - Relationship to abrupt climate oscillations, cryosphere and methane seepage from the seafloor 

      El Bani Altuna, Naima (Doctoral thesis; Doktorgradsavhandling, 2021-09-17)
      Climate change affects the Arctic to a greater extent than the global average, causing rapid sea-ice loss and changes in the inflow of warm Atlantic water in the Arctic. Arctic sediments host vast amounts of greenhouse gases in the form of gas hydrates (ice-like cages that trap gas within), that can be released to the seafloor if temperature increases and/or pressure decreases. Climate projections ...

    • Minor element abundances in the corona and solar wind 

      Byhring, Hanne Sigrun (Doctoral thesis; Doktorgradsavhandling, 2011-10-21)
      Using a time-dependent numerical model that spans the chromosphere, corona and solar wind, abundance variations resulting from gravitational settling in the chromosphere and corona have been studied. \noindent Gravitational settling in the chromosphere may lead to a depletion in the abundances of minor elements in the solar wind relative to the photosphere. The observed overabundance (relative ...

    • Model based Statistics for Protein Sequence Families 

      Ahmed, Said Hassan (Doctoral thesis; Doktorgradsavhandling, 2011-07-01)

    • Model-Driven Software Development for Continuity of Care Information Systems - Toolchain design and evaluation 

      Walderhaug, Ståle (Doctoral thesis; Doktorgradsavhandling, 2013-03-13)
      This thesis summarizes six years of design, development and evaluation of a model- driven development toolchain and design of software services for continuity of care. The overall research method has been design science, with a strong focus on creating and evaluating the core artefact: the ModelHealth Toolchain. Three iterations with toolchain design and assessments were deemed necessary to be able ...

    • Modeling Energy Consumption of Computing Systems: from Homogeneous to Heterogeneous Systems 

      Tran, Vi Ngoc-Nha (Doctoral thesis; Doktorgradsavhandling, 2019-09-06)
      Nowadays, reducing energy consumption and improving the energy efficiency of computing systems become ones of the leading research topics in computer science. In order to improve energy efficiency, it is crucial to understand how computing systems consume energy. Power and energy models provide prediction and insight into how computing systems consume power and energy. However, it is challenging to ...

    • Modelling the subglacial hydrology of the former Barents Sea Ice Sheet 

      Gudlaugsson, Eythor (Doctoral thesis; Doktorgradsavhandling, 2015-12-01)
      Ice dynamics are strongly controlled by processes taking place at the interface between the ice and the underlying bed. In modern day ice sheets, up to 90% of mass is lost through fast-flowing corridors of ice, called ice streams. These are typically underlain by a thin layer of water and wet sediment, both of which promote fast flow. In recent years it has emerged that subglacial hydrology played ...

    • The molecular origin of cold adaptation: A comparative study of cold- and warm-active uracil DNA glycosylase 

      Olufsen, Magne (Doctoral thesis; Doktorgradsavhandling, 2007-05-25)
      During the last decade or so, scientists at the Norwegian Structural Biology Centre (NorStruct) have used the enzyme uracil DNA glycosylase (UDG) as a model system in the study of cold-adaptation, protein-DNA recognition and enzyme specificity. The cod UDG (cUDG) and human UDG (hUDG) are thoroughly biologically characterized and there are established well-functioning recombinant expression systems ...

    • Monitoring of Marine Ice and its Thickness for Ship Anti-/De-icing - Experimental and Analytical Study using Infrared Thermography 

      Rashid, Taimur (Doctoral thesis; Doktorgradsavhandling, 2019-03-01)
      Ships operating in a cold climate face many challenges. There are several associated risks such as safety concerns, down time, energy consumption and limited resources. Amongst the key challenges, ship ice accretion is significant for cold climate operations. Exposing superstructures to the marine icing phenomenon can affect the ship’s operations, risking the safety of humans and machines. In this ...