Viser treff 170-189 av 290

    • Neoproterozoic orogenesis in south-eastern South America - An examination of pre-orogenic rifting, sedimentation, and mountain building processes recorded in the Dom Feliciano Belt 

      Percival, Jack James (Doctoral thesis; Doktorgradsavhandling, 2022-01-25)
      The Dom Feliciano Belt records the convergence between multiple South American and African cratonic bodies during the Neoproterozoic, and forms part of the larger South Atlantic Neoproterozoic Orogenic System (SANOS). Studying the evolution of the Dom Feliciano Belt allows the development of tectonic models spanning the time from pre-orogenic rifting to orogenesis, and the information recorded in ...
    • New Building Blocks for Cancer Phototherapeutics: 5d Metallocorroles 

      Einrem, Rune Finsås (Doctoral thesis; Doktorgradsavhandling, 2023-02-24)
      Corroles are ring-contracted, triprotic analogues of porphyrins. This PhD study expands earlier knowledge in particular on ReO corroles. Early on, it became apparent that ReO corroles exhibit the highest phosphorescence quantum yields among all metallocorroles. They also sensitize singlet oxygen formation and serve as oxygen sensors and as triplet-triplet annihilation upconverters. I accordingly ...
    • New Corrole Analogues: Isocorroles and Azulicorrole 

      Larsen, Simon (Doctoral thesis; Doktorgradsavhandling, 2020-02-25)
      Porphyrinoids are a family of molecules, which consist of large ring structures or macrocycles. One of the oldest, and most important, of the porphyrinoids is the biological molecule called porphyrin. Since the dawn of life, porphyrins have orchestrated photosynthesis and oxygen respiration, two of the most important energy-generating processes in nature. In addition to porphyrins, other porphyrinoids ...
    • Non-Gaussian statistical analysis of polarimetric synthetic aperture radar images 

      Doulgeris, Anthony Paul (Doctoral thesis; Doktorgradsavhandling, 2011-02-18)
      This thesis describes general methods to analyse polarimetric synthetic aperture radar images, with the primary application of unsupervised image segmentation. The fundamental physics of electromagnetic scattering from distributed targets leads to the image phenomenon called speckle. Speckle is shown to be potentially non-Gaussian and several statistical distributions are investigated. Non-Gaussianity ...
    • The nonlinear nature of biology 

      Måløy, Marthe (Doctoral thesis; Doktorgradsavhandling, 2019-03-27)
      In this thesis, we explore the stability and the breakdown of stability of biological systems. The main examples are the blood system and invasion of cancer. However, the models presented in the thesis apply to several other examples. Biological systems are characterised by both competition and cooperation. Cooperation is based on an unsolvable dilemma: Even though mutual cooperation leads to ...
    • Nonlinear optics 

      Juhász, Dávid (Doctoral thesis; Doktorgradsavhandling, 2021-09-24)
      Nonlinear light-matter interactions have been drawing attention of physicists since the 1960's. Quantum mechanics played a significant role in their description and helped to derive important formulas showing the dependence on the intensity of the electromagnetic field. High intensity light is able to generate second and third harmonics which translates to generation of electromagnetic field with ...
    • North Atlantic–Norwegian Sea exchanges during the past 135,000 years: Evidence from foraminiferal ∆14C, d11B, d18O, d13C, Mg/Ca, and Cd/Ca 

      Ezat, Mohamed M. (Doctoral thesis; Doktorgradsavhandling, 2015-07-03)
      The ocean is an essential regulator of climate through its effect on redistribution of heat and air-sea exchange of greenhouse gases.The modern circulation pattern of surface and deep water between the Arctic Mediterranean seas and North Atlantic is an important part of the global meridional ocean circulation. In this study we investigate the North Atlantic-Norwegian Sea exchanges of heat and carbon ...
    • Novel aspects of pathogenicity of Aliivibrio salmonicida 

      Kashulin, Alexander (Doctoral thesis; Doktorgradsavhandling, 2014-06-19)
      Analysis of the fish health reports annually published online by the Norwegian Veterinary Institute (data available starting from 2005), have demonstrated a good epidemiological situation with Cold Water Vibriosis (CWV) in 2005-2010. During this 5 year period only 4 cases were detected in Norway. Starting from 2011 the situation began to change and only during 2011, 5 cases of CWV have been detected ...
    • Novel strategies for super-resolution fluorescence microscopy 

      Lahrberg, Marcel (Doctoral thesis; Doktorgradsavhandling, 2019-12-11)
      <p>Minimally invasive technologies to characterize the structure and functionality of biological samples on the cellular and molecular scale are fundamental to life sciences. Optical fluorescence imaging at visible wavelengths is able to acquire to do so. Due to the wavelike nature of light the maximum achievable resolution in conventional microscopy is limited by diffraction, about half the wavelength ...
    • Numerical simulations and stochastic modeling of intermittent fluctuations in magnetized plasmas 

      Decristoforo, Gregor (Doctoral thesis; Doktorgradsavhandling, 2021-05-21)
      The exhaust of particles and heat in the boundary of contemporary magnetic confinement experiments remains to this day a major obstacle on the road to commercially viable fusion energy production. It is recognized, that coherent structures of hot and dense plasma, called blobs or filaments, are the dominant mechanism for cross-field particle transport. These filaments are created by plasma turbulence ...
    • 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 ...
    • 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 ...
    • On Automated Classification of Sea Ice Types in SAR Imagery 

      Lohse, Johannes (Doctoral thesis; Doktorgradsavhandling, 2021-03-12)
      With the Arctic sea ice continuously decreasing in both extent and thickness, fast and robust production of reliable ice charts becomes more important to ensure the safety of Arctic operations. This thesis focuses on the development of automated algorithms for the mapping of sea ice from synthetic aperture radar (SAR) images. It presents a thorough background on the topics of sea ice observations ...
    • On local and long-range transported air pollution in Svalbard 

      Dekhtyareva, Alena (Doctoral thesis; Doktorgradsavhandling, 2019-09-11)
      Climate change, health of the residents and ecosystems in the Arctic region are impacted by local and long-range transported air pollution. Local emissions in the Arctic are important, but overlooked issue. Despite there have been extensive modelling and measurement studies of long-range transport of short-lived climate forcers to Svalbard, the effect of local emissions from diesel and coal power ...
    • On polar lows and their formation 

      Stoll, Patrick Johannes (Doctoral thesis; Doktorgradsavhandling, 2020-09-18)
      Polar lows are small, but extreme cyclones that develop in marine polar air mass. They feature one of the largest natural hazards in the polar regions. Their associated strong winds, high waves, substantial amounts of snow fall, low visibility and possibility for ice accumulation on ships and airplanes cause threats for coastal communities and marine operations. Hence, accurate prediction of polar ...
    • On sea-ice forecasting 

      Fritzner, Sindre Markus (Doctoral thesis; Doktorgradsavhandling, 2020-05-15)
      Accurate sea-ice prediction is essential for safe operations in the Arctic and potentially also for weather forecast at high-latitudes. The increasing number of sea-ice related satellite observations in the Arctic can be used to improve the model predictions through data assimilation. For sea ice, sea-ice concentration (SIC) observations have been available for many years. Observational information ...
    • On the Evolvability of OXA-48. A comprehensive study of new functions within the β-lactamase OXA-48 

      Fröhlich, Christopher (Doctoral thesis; Doktorgradsavhandling, 2021-08-27)
      Our understanding of how antimicrobial resistance enzymes evolve to expand their substrate spectrum is limited. OXA-48, an enzyme able to catalyse the hydrolysis of β-lactam drugs, has become one of the most successfully disseminating β-lactamases. Although OXA-48 hydrolyses penicillins with high efficiency, its activity towards oxyimino cephalosporins, such as ceftazidime, is limited. Thus, ceftazidime ...
    • 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, ...
    • On the linkage between atmospheric circulation changes and Arctic climate change 

      Heiskanen, Tuomas Ilkka Henrikki (Doctoral thesis; Doktorgradsavhandling, 2022-06-10)
      Polar amplification is a prominent feature of recent and projected climate change. The Arctic region shows some of the strongest signs of climate change, including sea-ice retreat and temperatures increasing at twice the rate averaged over the northern hemisphere. A major concern for humanity is the sea-level rise associated with the melting of the ice-sheets and glaciers due to climate change. The ...
    • On the time-dependence of climate sensitivity 

      Eiselt, Kai-Uwe (Doctoral thesis; Doktorgradsavhandling, 2023-11-03)
      Climate sensitivity is the change of the global-mean surface temperature in response to a doubling of the CO2 concentration. It is typically used to describe climate change and to inform decision-making for mitigation and adaptation. Climate sensitivity is often estimated in numerical climate model experiments. A remarkable result from these experiments is that climate sensitivity changes over time. ...