Now showing items 2441-2460 of 5378

    • Neodymium isotope constraints on chemical weathering and past glacial activity in Svalbard 

      Jang, Kwangchul; Bayon, Germain; Han, Yeongcheol; Joo, Young Ji; Kim, Ji-Hoon; Ryu, Jong-Sik; Woo, Jusun; Forwick, Matthias; Szczuciński, Witold; Kim, Jung-Hyun; Nam, Seung-Il (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-15)
      <p>Neodymium (Nd) isotopes in leached authigenic components of marine sediments have been increasingly used as a tracer of past ocean-water masses. Despite the general assumption that the Nd isotopic composition of solutes released during chemical weathering fingerprints the source rocks on continents, preferential dissolution of easily dissolvable phases may result in significant deviations in Nd ...
    • The role of shelf morphology on storm-bed variability and stratigraphic architecture, Lower Cretaceous, Svalbard 

      Grundvåg, Sten-Andreas; Jelby, Mads Engholm; Olaussen, Snorre; Sliwinska, Kasia (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-13)
      The dominance of isotropic hummocky cross‐stratification, recording deposition solely by oscillatory flows, in many ancient storm‐dominated shoreface–shelf successions is enigmatic. Based on conventional sedimentological investigations, this study shows that storm deposits in three different and stratigraphically separated siliciclastic sediment wedges within the Lower Cretaceous succession in ...
    • Miocene Seep-Carbonates of the Northern Apennines (Emilia to Umbria, Italy): An Overview 

      Conti, Stefano; Argentino, Claudio; Fioroni, Chiara; Salocchi, Aura Cecilia; Fontana, Daniela (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-28)
      The natural emission of methane-rich fluids from the seafloor, known as cold seepage, is a widespread process at modern continental margins. The studies on present-day cold seepages provide high-resolution datasets regarding the fluid plumbing system, biogeochemical processes in the sediment, seafloor seepage distribution and ecosystems. However, the long-term (hundreds of thousands to millions of ...
    • Exhumation of the High‐Pressure Tsäkkok Lens, Swedish Caledonides: Insights From the Structural and White Mica 40Ar/39Ar Geochronological Record 

      Barnes, C.J.; Jeanneret, P.; Kullerud, Kåre; Majka, J.; Schneider, D.A.; Bukala, M.; Klonowska, I. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-12)
      Integrated structural, geochemical, and geochronological investigations were conducted on metasedimentary rocks in the eclogite-bearing Tsäkkok Lens of the Seve Nappe Complex (Scandinavian Caledonides) to resolve its exhumation history. Three deformation events are defined. D1 is likely related to the prograde to peak-metamorphic stages, represented by a locally preserved S1. D2 resulted in vertical ...
    • Feasibility of using the P-Cable high-resolution 3D seismic system in detecting and monitoring CO2 leakage 

      Waage, Malin; Singhroha, Sunny; Bünz, Stefan; Planke, Sverre; Waghorn, Kate Alyse; Bellwald, Benjamin (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-23)
      The P-Cable technology is an acquisition principle for high-resolution and ultra-high-resolution 3D seismic data. Many 3D seismic datasets have been acquired over the last decade, but the application in time-lapse studies for monitoring of CO2 storage is a new and intriguing topic. High-resolution 3D (HR3D) seismic has the potential to detect and monitor CO2 leakage at carbon capture and storage ...
    • Silicon substrate significantly alters dipole-dipole resolution in coherent microscope 

      Liu, Zicheng; Agarwal, Krishna (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-16)
      Considering a coherent microscopy setup, influences of the substrate below the sample in the imaging performances are studied, with a focus on high refractive index substrate such as silicon. Analytical expression of 3D full-wave vectorial point spread function, i.e. the dyadic Green's function is derived for the optical setup together with the substrate. Numerical analysis are performed in order ...
    • Deep learning architecture “LightOCT” for diagnostic decision support using optical coherence tomography images of biological samples 

      Butola, Ankit; Prasad, Dilip Kumar; Ahmad, Azeem; Dubey, Vishesh Kumar; Qaiser, Darakhshan; Srivastava, Anurag; Senthilkumaran, Paramasivam; Ahluwalia, Balpreet Singh; Mehta, Dalip Singh (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-13)
      Optical coherence tomography (OCT) is being increasingly adopted as a label-free and non-invasive technique for biomedical applications such as cancer and ocular disease diagnosis. Diagnostic information for these tissues is manifest in textural and geometric features of the OCT images, which are used by human expertise to interpret and triage. However, it suffers delays due to the long process of ...
    • Molecular Structure of Copper and μ-Oxodiiron Octafluorocorrole Derivatives: Insights into Ligand Noninnocence 

      Thomas, Kolle E.; Settineri, Nicholas S.; Teat, Simon J.; Steene, Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-23)
      Single-crystal X-ray structures were obtained for the copper and μ-oxodiiron complexes of 2,3,7,8,12,13,17,18-octafluoro-5,10,15-triphenylcorrole, hereafter denoted as Cu[F8TPC] and {Fe[F8TPC]}2O. A comparison with the crystal structures of other undecasubstituted Cu corroles, including those with H, Ar, Br, I, and CF3 as β-substituents, showed that the degree of saddling increases in the order: H ...
    • Protonation-Induced Hyperporphyrin Spectra of meso-Aminophenylcorroles 

      Thomassen, Ivar K.; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-06)
      UV–vis spectrophotometric titrations have been carried out on <i>meso</i>-tris(<i>o/m/p</i>-aminophenyl)corrole (H<sub>3</sub>[<i>o/m/p</i>-TAPC]) and meso-triphenylcorrole (H<sub>3</sub>[TPC]) in dimethyl sulfoxide with methanesulfonic acid (MSA). Monoprotonation was found to result in hyperporphyrin spectra characterized by new, red-shifted, and intense Q bands. The effect was particularly dramatic ...
    • Facile Supramolecular Engineering of Porphyrin cis Tautomers: The Case of β-Octabromo-meso-tetraarylporphyrins 

      Thomas, Kolle E.; Slebodnick, Carla; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-02)
      A porphyrin cis tautomer, where the two central NH protons are on adjacent pyrrole rings, has long been invoked as an intermediate in porphyrin tautomerism. Only recently, however, has such a species been isolated and structurally characterized. Thus, single-crystal X-ray structure determinations of two highly saddled free-base porphyrins, β-heptakis(trifluoromethyl)-meso-tetrakis(p-fluorophenyl)porphyrin, ...
    • Nature of the copper-nitrosyl intermediates of copper nitrite reductases during catalysis 

      Hough, Michael A.; Conradie, Jeanet; Strange, Richard W.; Antonyuk, Svetlana V.; Eady, Robert R.; Ghosh, Abhik; Hasnain, S. Samar (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-20)
      The design and synthesis of copper complexes that can reduce nitrite to NO has attracted considerable interest. They have been guided by the structural information on the catalytic Cu centre of the widespread enzymes Cu nitrite reductases but the chemically novel side-on binding of NO observed in all crystallographic studies of these enzymes has been questioned in terms of its functional relevance. ...
    • X-ray absorption spectroscopy of archetypal chromium porphyrin and corrole derivatives 

      Cao, Rui; Thomas, Kolle E.; Ghosh, Abhik; Sarangi, Ritimukta (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-29)
      A combination of Cr K-edge XAS and DFT calculations have been performed on archetypal chromium porphyrinoid complexes Cr<sup>IV</sup>[TMP]O (<b>2</b>) and Cr<sup>V</sup>[TPC]O (<b>3</b>), and the results have been compared to the reference compound Cr<sup>III</sup>[TPP]Cl (<b>1</b>), where TPP<sup>2−</sup>, TMP<sup>2−</sup>, and TPC<sup>3−</sup> are the anions of <i>meso</i>-tetraphenylporphyrin, ...
    • Properties and dynamics of mesoscale eddies in Fram Strait from a comparison between two high-resolution ocean-sea ice models 

      Wekerle, Claudia; Hattermann, Tore; Wang, Qiang; Crews, Laura; von Appen, Wilken-Jon; Danilov, Sergey (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-23)
      Fram Strait, the deepest gateway to the Arctic Ocean, is strongly influenced by eddy dynamics. Here we analyse the output from two eddy-resolving models (ROMS – Regional Ocean Modeling System; FESOM – Finite-Element Sea-ice Ocean Model) with around 1 km mesh resolution in Fram Strait, with a focus on their representation of eddy properties and dynamics. A comparison with mooring observations shows ...
    • GeneNet VR: Large Biological Networks in Virtual Reality Using Inexpensive Hardware 

      Martínez Fernández, Álvaro (Master thesis; Mastergradsoppgave, 2020-11-15)
      Biological data is often visualized using networks. However, these networks face problems such as information overload, high interconnectivity, and high dimensionality. Existing approaches try to solve these problems by reducing the interactivity in favor of presenting more information or by using expensive hardware. This thesis aims to solve them using Virtual Reality (VR) and the Oculus Quest, an ...
    • Improving the text compression ratio for ASCII text Using a combination of dictionary coding, ASCII compression, and Huffman coding 

      Haldar-Iversen, Sondre (Mastergradsoppgave; Master thesis, 2020-11-15)
      Data compression is a field that has been extensively researched. Many compression algorithms in use today have been around for several decades, like Huffman Coding and dictionary coding. These are general-purpose compression algorithms and can be used on anything from text data to images and video. There are, however, much fewer lossless algorithms that are customized for compressing certain types ...
    • Object detection at the edge 

      Mathiassen, Truls (Mastergradsoppgave; Master thesis, 2020-11-10)
      While monitoring rodents in the Arctic Tundra to evaluate if climate changes affect the ecosystem. The camera-traps of the coat project generates image data in large scale each year. To manually examine the data in regards to label- ing is a tedious and time-consuming job, and a more efficient and automated tool for the task is required. In this thesis we presents the architecture, design and ...
    • The high catalytic rate of the cold-active Vibrio alkaline phosphatase requires a hydrogen bonding network involving a large interface loop 

      Hjörleifsson, Jens Guðmundur; Helland, Ronny; Magnusdottir, Manuela; Ásgeirsson, Bjarni (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-16)
      The role of surface loops in mediating communication through residue networks is still a relatively poorly understood part in the study of cold adaptation of enzymes, especially in terms of their quaternary interactions. Alkaline phosphatase (AP) from the psychrophilic marine bacterium <i>Vibrio splendidus</i> (VAP) is characterized by an analogous large surface loop in each monomer, referred to as ...
    • Features extraction of wind ramp events from a virtual wind park 

      Mishra, Sambeet; Oren, Esin; Bordin, Chiara; Wen, Fushuan; Palu, Ivo (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-26)
      In the European renewable energy portfolio, wind has a sizeable share in the total energy production. The Nordic and Baltic energy systems in particular are benefiting from wind energy to reach the greenhouse gas emissions reduction objectives set by the EU. The wind energy production varies with time, and this intermittent characteristic imposes a challenge for full utilization of renewable energy ...
    • Integrated analysis of multi-sensor datasets and oil drift simulations - a free floating oil experiment in the open ocean 

      Brekke, Camilla; Espeseth, Martine; Dagestad, Knut-Frode; Röhrs, Johannes; Hole, Lars Robert; Reigber, Andreas (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-20)
      A free‐floating oil spill experiment (two oil types) in the open ocean is described, and the results from slick characterization through integrated analysis of drift simulations with remote sensing and in situ data are discussed. We compare oil drift simulations (OpenOil), applying various configurations of wind, wave, and current information, with the observed slick positions and shape. We describe ...
    • Snow avalanche segmentation in SAR images with Fully Convolutional Neural Networks 

      Bianchi, Filippo Maria; Grahn, Jakob; Eckerstorfer, Markus; Malnes, Eirik; Vickers, Hannah (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-10)
      Knowledge about frequency and location of snow avalanche activity is essential for forecasting and mapping of snow avalanche hazard. Traditional field monitoring of avalanche activity has limitations, especially when surveying large and remote areas. In recent years, avalanche detection in Sentinel-1 radar satellite imagery has been developed to improve monitoring. However, the current state-of-the-art ...