Now showing items 2521-2540 of 5379

    • A scalable and green one-minute synthesis of substituted phenols 

      Elumalai, Vijayaragavan; Hansen, Jørn H (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-07)
      A mild, green and highly efficient protocol was developed for the synthesis of substituted phenols via <i>ipso</i>-hydroxylation of arylboronic acids in ethanol. The method utilizes the combination of aqueous hydrogen peroxide as the oxidant and H<sub>2</sub>O<sub>2</sub>/HBr as the reagent under unprecedentedly simple and convenient conditions. A wide range of arylboronic acids were smoothly ...
    • Fault-controlled fluid circulation and diagenesis along basin-bounding fault systems in rifts - Insights from the East Greenland rift system 

      Salomon, Eric; Rotevatn, Atle; Kristensen, Thomas Berg; Grundvåg, Sten-Andreas; Henstra, Gijs Allard; Meckler, Anna Nele; Albert, Richard; Gerdes, Axel (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-05)
      In marine rift basins, deep-water clastics (>200 m) in the hanging wall of rift- or basin-bounding fault systems are commonly juxtaposed against crystalline “basement” rocks in the footwall. A distinct feature of such fault systems is therefore the juxtaposition of relatively highly permeable, unconsolidated sediments against relatively low-permeable basement rocks. Due to limited surface exposure ...
    • Dynamically controlled hydrocarbon column heights in fault bounded traps of the Hammerfest Basin, SW Barents Sea. Fault valve theory applied to the Snøhvit field 

      Kiss, Akos (Master thesis; Mastergradsoppgave, 2019-11-18)
      During initial exploration efforts in the Barents Sea several gas prone and underfilled prospects were drilled which significantly dropped the interest in the area. The Hammerfest Basin however turned out to hold significant hydrocarbon volumes. Although still mostly underfilled, the discoveries here today make up the Snøhvit oil and gas field. The Hammerfest Basin is an overfilled petroleum basin, ...
    • Short-Term Load Forecasting with Missing Data using Dilated Recurrent Attention Networks 

      Choi, Changkyu; Bianchi, Filippo Maria; Kampffmeyer, Michael; Jenssen, Robert (Conference object; Konferansebidrag, 2020-02-06)
      Forecasting the dynamics of time-varying systems is essential to maintaining the sustainability of the systems. Recent studies have discovered that Recurrent Neural Networks(RNN) applied in the forecasting tasks outperform conventional models that include AutoRegressive Integrated Moving Average(ARIMA). However, due to the structural limitation of vanilla RNN which holds unit-length internal ...
    • Relationship between microstructures and resistance in mafic assemblages that deform and transform 

      Mansard, Nicolas; Stunitz, Holger; Raimbourg, Hugues; Précigout, Jacques; Plunder, Alexis; Nègre, Lucille (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-18)
      Syn-kinematic mineral reactions play an important role for the mechanical properties of polymineralic rocks. Mineral reactions (i.e., nucleation of new phases) may lead to grain size reduction, producing fine-grained polymineralic mixtures, which have a strongly reduced viscosity because of the activation of grain-size-sensitive deformation processes. In order to study the effect of deformation–reaction ...
    • High space-bandwidth in quantitative phase imaging using partially spatially coherent digital holographic microscopy and a deep neural network 

      Butola, Ankit; Kanade, Sheetal Raosaheb; Bhatt, Sunil; Dubey, Vishesh Kumar; Kumar, Anand; Ahmad, Azeem; Prasad, Dilip K.; Senthilkumaran, Paramasivam; Ahluwalia, Balpreet Singh; Mehta, Dalip Singh (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-16)
      Quantitative phase microscopy (QPM) is a label-free technique that enables monitoring of morphological changes at the subcellular level. The performance of the QPM system in terms of spatial sensitivity and resolution depends on the coherence properties of the light source and the numerical aperture (NA) of objective lenses. Here, we propose high space-bandwidth quantitative phase imaging using ...
    • Productive detours – Atlantic water inflow and acoustic backscatter in the major troughs along the Svalbard shelf 

      Menze, Sebastian; Ingvaldsen, Randi Brunvær; Nikolopoulos, Anna; Hattermann, Tore; Albretsen, Jon; Gjøsæter, Harald (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-30)
      Atlantic Water (AW) flowing along the western and northern Svalbard shelf-break extends the Atlantic domain into the Arctic and is the region’s major source of heat, nutrients and advected plankton. We investigated the inflow and recirculation of AW into four major troughs that cut into the Svalbard shelf, the Isfjorden, Kongsfjorden, Hinlopen and Kvitøya Troughs, and related the circulation patterns ...
    • Methanotroph populations and CH 4 oxidation potentials in High Arctic peat are altered by herbivory induced vegetation change 

      Rainer, Edda Marie; Seppey, Victor William Christophe; Tveit, Alexander Tøsdal; Svenning, Mette Marianne (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-08)
      Methane oxidizing bacteria (methanotrophs) within the genus <i>Methylobacter</i> constitute the biological filter for methane (CH<sub>4</sub>) in many Arctic soils. Multiple <i>Methylobacter</i> strains have been identified in these environments but we seldom know the ecological significance of the different strains. High-Arctic peatlands in Svalbard are heavily influenced by herbivory, leading to ...
    • First-Principles Calculation of 1H NMR Chemical Shifts of Complex Metal Polyhydrides: The Essential Inclusion of Relativity and Dynamics 

      Castro, Abril C; Balcells, David; Repisky, Michal; Helgaker, Trygve; Cascella, Michele (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-23)
      <sup>1</sup>H NMR spectroscopy has become an important technique for the characterization of transition-metal hydride complexes, whose metal-bound hydrides are often difficult to locate by X-ray diffraction. In this regard, the accurate prediction of <sup>1</sup>H NMR chemical shifts provides a useful, but challenging, strategy to help in the interpretation of the experimental spectra. In this work, ...
    • On-chip TIRF nanoscopy by applying Haar wavelet kernel analysis on intensity fluctuations induced by chip illumination 

      Jayakumar, Nikhil; Helle, Øystein I.; Agarwal, Krishna; Ahluwalia, Balpreet Singh (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-09)
      Photonic-chip based TIRF illumination has been used to demonstrate several on-chip optical nanoscopy methods. The sample is illuminated by the evanescent field generated by the electromagnetic wave modes guided inside the optical waveguide. In addition to the photokinetics of the fluorophores, the waveguide modes can be further exploited for introducing controlled intensity fluctuations for exploitation ...
    • Highly temporal stable, wavelength-independent, and scalable field-of-view common-path quantitative phase microscope 

      Ahmad, Azeem; Dubey, Vishesh Kumar; Butola, Ankit; Ahluwalia, Balpreet Singh; Mehta, Dalip Singh (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-11)
      <p><i>Significance:</i> High temporal stability, wavelength independency, and scalable field of view (FOV) are the primary requirements of a quantitative phase microscopy (QPM) system. The high temporal stability of the system provides accurate measurement of minute membrane fluctuations of the biological cells that can be an indicator of disease diagnosis. <p><i>Aim:</i> The main aim of this work ...
    • Incorporating capture heterogeneity in the estimation of autoregressive coefficients of animal population dynamics using capture–recapture data 

      Nicolau, Pedro Guilherme; Sørbye, Sigrunn Holbek; Yoccoz, Nigel (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-31)
      Population dynamic models combine density dependence and environmental effects. Ignoring sampling uncertainty might lead to biased estimation of the strength of density dependence. This is typically addressed using state‐space model approaches, which integrate sampling error and population process estimates. Such models seldom include an explicit link between the sampling procedures and the true ...
    • Deformation mechanisms accommodating progressive simple shear thrusting of quartzite and metacarbonate in the southwestern Espinhaço Range, Brazil 

      Taufner, Rhander; Lagoeiro, Leonardo E.; Cavalcante, Carolina; Barbosa, Paola; Silveira, Camila Santos (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-09)
      The accommodation of low-temperature ductile deformation in foreland fold-and-thrust belts is often described in terms of outcrop-based geometric analysis, but microtextural observations are also important, as they relate stress, strain, fluids and temperature and thus the rheology in the peripheral part of the orogen. Such microtextural observations are lacking from the foreland part of the Araçuaí ...
    • Leveraging Kernels for Unsupervised Learning 

      Løkse, Sigurd (Doctoral thesis; Doktorgradsavhandling, 2020-12-11)
      <p>Kernel methods have been a central part of the machine learning arsenal for several decades. Within this framework, unsupervised learning has been a particularly challenging area. This is due to the inherent nature of unsupervised learning tasks, where important information about the structure of the data is unknown to the user, and as such it is difficult to design a kernel or system to solve ...
    • Structural analysis along seismic profiles trough late-Paleozoic deposits in Billefjorden and Sassenfjorden, Svalbard and their relation to the Billefjorden Fault Zone 

      Kubiak, Agata (Mastergradsoppgave; Master thesis, 2020-11-09)
      The focus of this thesis is structural analysis of the Billefjorden Fault Zone astride Billefjorden and Sassenfjorden in Spitsbergen, with the use of seismic interpretation combined/aided by geological and bathymetric maps, field observations and well data. The aim is to describe structures and the tectonic development of the study area. The focus is on large tectonic events from Devonian to ...
    • Performance Measurement System in complex environment: observed and unobserved risk factors 

      Zaki, Rezgar (Doctoral thesis; Doktorgradsavhandling, 2020-12-04)
      <p>World demand for energy leads industry to harvest energy in complex environment with harsh conditions and sensitive areas, such as the Arctic region – one of the last remaining wild places in the world – with potentially harmful consequences. Moreover, over the past few decades, the increasing trend of melting sea ice in the Arctic has provided increased access and has created new opportunities ...
    • Fracture characterization in Upper Permian carbonates in Spitsbergen: A workflow from digital outcrop to geo-model 

      Larssen, Kristine; Senger, Kim; Grundvåg, Sten-Andreas (Journal article; Tidsskriftartikkel, 2020-09-08)
      Carbonates represent major hydrocarbon reservoirs, but often exhibit highly heterogeneous reservoir properties. Outcrop analogues provide important insights into how parameters such as porosity, permeability and natural fractures vary. As such, outcrops can bridge the scale gap between spatially extensive but poor-resolution seismic data and 1D high-resolution well data. However, traditional geological ...
    • An Early Neogene—Early Quaternary Contourite Drift System on the SW Barents Sea Continental Margin, Norwegian Arctic 

      Rydningen, Tom Arne; Høgseth, Gert; Lasabuda, Amando Putra Ersaid; Laberg, Jan Sverre; Safronova, Polina; Forwick, Matthias (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-30)
      The onset and evolution of the middle to late Cenozoic “icehouse” world was influenced by the development of the global ocean circulation linking the Norwegian–Greenland Sea-Arctic Ocean to the Atlantic Ocean. The evolution of the early Neogene to early Quaternary Bjørnøyrenna Drift, located at the SW Barents Sea continental margin, shed new light on this important hydrological event. By analyzing ...
    • Novel Synthesis of Lipoxine A4 Analogues. Towards Allostric Modulators for Human Cannabinoid Receptor Type 1 

      Ismael, Aya (Master thesis; Mastergradsoppgave, 2015-11-15)
      The synthesis of the benzoid-based lipoxine A4 (LXA4) is the focus of this study specifically, the para substituted benzoid system. LXA4 is an endogenous agonist binding with high affinity to (ALXR) receptor that initiate it to display anti-inflammatory and antioxidant activities. Arachidonic acid is the cascade of LXA4 and its derivatives. These compounds belong to the biological active eicosanoids, ...
    • The Svalbard Eocene-Oligocene (?) Central Basin succession: Sedimentation patterns and controls 

      Helland-Hansen, William; Grundvåg, Sten-Andreas (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-12)
      A synthesis has been undertaken based on regionally compiled data from the post early Eocene foreland basin succession of Svalbard. The aim has been to generate an updated depositional model and link this to controlling factors. The more than kilometer thick progradational succession includes the offshore shales of the Gilsonryggen Member of the Frysjaodden Formation, the shallow marine sandstones ...