Now showing items 1941-1960 of 5336

    • Benthic foraminiferal assemblages and environmental drivers along the Kveithola Trough (NW Barents Sea) 

      Caridi, Francesca; Sabbatini, Anna; Bensi, Manuel; Kovačević, Vedrana; Lucchi, Renata Giulia; Morigi, Caterina; Povea, Patricia; Negri, Alessandra (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-14)
      We describe the population density, biodiversity and vertical distribution in the sediment of benthic foraminifera, and their relationship to environmental parameters, in the Kveithola Trough (NW Barents Sea). Two staining methods, Cell Tracker Green (CTG) and Rose Bengal (RB), were used to distinguish between living and dead tests. CTG proved to be more effective than RB, and we therefore used this ...
    • Sheared Peridotite and Megacryst Formation Beneath the Kaapvaal Craton: A Snapshot of Tectonomagmatic Processes across the Lithosphere-Asthenosphere Transition 

      Tappe, Sebastian; Massuyeau, Malcolm; Smart, Katie A; Woodland, Alan B; Gussone, Nikolaus; Milne, Sarah; Stracke, Andreas (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-27)
      The cratonic lithosphere–asthenosphere boundary is commonly invoked as the site of sheared peridotite and megacryst formation, a well-recognized petrological assemblage whose genetic relationships—if any—remain poorly understood. We have undertaken a comprehensive petrology and Sr–Nd–Hf–Ca isotope study of sheared peridotite xenoliths and clinopyroxene megacrysts from the c. 1150 Ma Premier kimberlite ...
    • Electron Density Depletion Region Observed in the Polar Cap Ionosphere 

      Bjoland, Lindis Merete; Ogawa, Y.; Løvhaug, Unni Pia; Lorentzen, Dag Arne; Hatch, Spencer Mark; Oksavik, Kjellmar (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-16)
      This paper presents and discusses electron density depletion regions observed with the incoherent scatter EISCAT Svalbard Radar (ESR) located at 75.43°N geomagnetic latitude. The data include several decades of measurements, which make them suitable for studying statistical features and characteristics of the ionospheric parameters. Here we focus on the electron density depletions and their dependence ...
    • Evolution and temporal constraints of a multiphase postglacial rock slope failure 

      Vick, Louise Mary; Mikkelsen, Martin; Corner, Geoffrey; Kjellman, Sofia Elisabeth; Trønnes, Leif; Hormes, Anne; Allaart, Lis; Bergh, Steffen G (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-05)
      Large rock slope failures are temporal processes which act to modify the landscape after glacial retreat. The slope failure process often shows a lag time of thousands of years after deglaciation, with multiple failure events possible. While global datasets constrain this lag time from extensive mapping and dating of paraglacial rock avalanches, the timeline is poorly refined in northern Norway. We ...
    • Applications of Multiwavelets to Energies and Properties 

      Brakestad, Anders (Doctoral thesis; Doktorgradsavhandling, 2022-02-18)
      The goal of quantum chemistry is to provide fast and accurate algorithms for the computation of molecular energies and properties. Over the years, a large number of methods have become available, and today computational chemists have a very rich toolbox of protocols that can be used to gain insight to chemistry. Gaussian type orbital (GTO) basis sets are at the core of most modern algorithms, and ...
    • Heterogeneous REE + Y distribution in Early Paleozoic shelly phosphorites: Implications for enrichment mechanisms 

      Lumiste, Kaarel; Lang, Liisa; Paiste, Päärn; Lepland, Aivo; Kirsimäe, Kalle (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-27)
      Sedimentary phosphorites are important carriers of Rare Earth Elements and Yttrium (REE + Y). Primary biogenic and sedimentary apatite contain very low amounts of REE + Y and enrichment of these elements occurs during diagenesis. Although the influence of post-depositional processes on REE + Y concentrations in sedimentary phosphorites is well established, the processes controlling the degree of ...
    • Motivation detection using EEG signal analysis by residual-in-residual convolutional neural network 

      Chattopadhyay, Soham; Zary, Laila; Quek, Chai; Prasad, Dilip K. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-05)
      While we know that motivated students learn better than non-motivated students but detecting motivation is challenging. Here we present a game-based motivation detection approach from the EEG signals. We take an original approach of using EEG-based brain computer interface to assess if motivation state is manifest in physiological EEG signals as well, and what are suitable conditions in order to ...
    • Deriving high contrast fluorescence microscopy images through low contrast noisy image stacks 

      Acuna Maldonado, Sebastian Andres; ROY, MAYANK; Villegas, Luis; Dubey, Vishesh Kumar; Ahluwalia, Balpreet Singh; Agarwal, Krishna (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-11)
      Contrast in fluorescence microscopy images allows for the differentiation between different structures by their difference in intensities. However, factors such as point-spread function and noise may reduce it, affecting its interpretability. We identified that fluctuation of emitters in a stack of images can be exploited to achieve increased contrast when compared to the average and Richardson-Lucy ...
    • Impact of temperature on the leaching of sulphate, Co, Fe, Mn, Ni and Zn from the Ballangen tailings deposit, Norway: A laboratory column experiment 

      Lu, Jinmei; Walder, Ingar; Leiviskä, Tiina (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-29)
      Temperature is an important factor affecting the leaching of contaminants from waste deposits, especially in the Nordic region where temperature change is more drastic than other areas. In this study, the impact of temperature variation in the leaching of sulphate, Co, Fe, Mn, Ni and Zn from the Ballangen tailings deposit, northern Norway, was investigated using a column leaching experiment. ...
    • On uniqueness of submaximally symmetric parabolic geometries 

      The, Dennis (Journal article; Tidsskriftartikkel, 2021)
      Among (regular, normal) parabolic geometries of type (G,P), there is a locally unique maximally symmetric structure and it has symmetry dimension dim(G). The symmetry gap problem concerns the determination of the next realizable (submaximal) symmetry dimension. When G is a complex or split-real simple Lie group of rank at least three or when (G,P)=(G2,P2), we establish a local classification result ...
    • Symmetry gaps for higher order ordinary differential equations 

      The, Dennis; Kessy, Johnson Allen (Journal article; Tidsskriftartikkel, 2021)
      The maximal contact symmetry dimensions for scalar ODEs of order ≥4 and vector ODEs of order ≥3 are well known. Using a Cartan-geometric approach, we determine for these ODE the next largest realizable (submaximal) symmetry dimension. Moreover, finer curvature-constrained submaximal symmetry dimensions are also classified.
    • Sol-Gel Thin Film Processing for Integrated Waveguide Sensors 

      Alberti, Sebastian; Jagerska, Jana (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-05)
      Integrated opto-chemical sensors present great advantages in comparison to the current lab equipment. They bring portability, reduced costs, facilitate in-situ measurements, as well as largely reduced sample volumes. In this quest, standard processing protocols over established materials, such as silicon nitride, silicon, silicon dioxide, titanium oxide, and even a wide variety of polymers have so ...
    • Mechanistic Insights into Copper-Catalyzed Carboxylations 

      Obst, Marc; Gevorgyan, Ashot; Bayer, Annette; Hopmann, Kathrin Helen (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-02)
      The copper-NHC-catalyzed carboxylation of organoboranes with CO<sub>2</sub> was investigated using computational and experimental methods. The DFT and DLPNO-CCSD(T) results indicate that nonbenzylic substrates are converted via an inner-sphere carboxylation of an organocopper intermediate, whereas benzylic substrates may simultaneously proceed along both inner- and outer-sphere CO<sub>2</sub> insertion ...
    • Modelling the influence of meteoric smoke particles on artificial heating in the D-region 

      Myrvang, Margaretha; Baumann, Carsten; Mann, Ingrid (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-17)
      We investigate if the presence of meteoric smoke particles (MSPs) influences the electron temperature during artificial heating in the D-region. By transferring the energy of powerful high-frequency radio waves into thermal energy of electrons, artificial heating increases the electron temperature. Artificial heating depends on the height variation of electron density. The presence of MSPs can ...
    • Second-Order PDEs in 3D with Einstein–Weyl Conformal Structure 

      Berjawi, S.; Ferapontov, E.V.; Kruglikov, Boris; Novikov, V.S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-07)
      Einstein–Weyl geometry is a triple (D,g,ω) where D is a symmetric connection, [g] is a conformal structure and ω is a covector such that ∙ connection D preserves the conformal class [g], that is, Dg=ωg; ∙ trace-free part of the symmetrised Ricci tensor of D vanishes. Three-dimensional Einstein–Weyl structures naturally arise on solutions of second-order dispersionless integrable PDEs in 3D. In this ...
    • Ocean Applications 

      Migliaccio, M.; Nunziata, F.; Marino, A.D.; Brekke, Camilla; Skrunes, Stine (Chapter; Bokkapittel, 2021-05-11)
      In this chapter, the most promising techniques to observe oil slicks and to detect metallic targets at sea using polarimetric synthetic aperture radar (SAR) data are reviewed and critically analysed. The detection of oil slicks in SAR data is made difficult not only by the presence of speckle but also by the presence of, e.g. biogenic films, low-wind areas, rain cells, currents, etc., which increase ...
    • Comparison between mirror Langmuir probe and gas-puff imaging measurements of intermittent fluctuations in the Alcator C-Mod scrape-off layer 

      Kube, Ralph; Theodorsen, Audun; Garcia, Odd Erik; Brunner, D; Labombard, B; Terry, James L. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-30)
      Statistical properties of the scrape-off layer plasma fluctuations are studied in ohmically heated plasmas in the Alcator C-Mod tokamak. For the first time, plasma fluctuations as well as parameters that describe the fluctuations are compared across measurements from a mirror Langmuir probe (MLP) and from gas-puff imaging (GPI) that sample the same plasma discharge. This comparison is complemented ...
    • Phidianidine A and Synthetic Analogues as Naturally Inspired Marine Antifoulants 

      Labriere, Christophe; Elumalai, Vijayaragavan; Staffansson, Jannie; Cervin, Gunnar; Le Norcy, Tiffany; Denardou, Hugo; Réhel, Karine; Moodie, Lindon W. K.; Hellio, Claire; Pavia, Henrik; Hansen, Jørn H; Svenson, Johan (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-15)
      Stationary and slow-moving marine organisms regularly employ a natural product chemical defense to prevent being colonized by marine micro- and macroorganisms. While these natural antifoulants can be structurally diverse, they often display highly conserved chemistries and physicochemical properties, suggesting a natural marine antifouling pharmacophore. In our current report, we investigate the ...
    • International collaboration for meeting the challenges of huge and cascading disasters 

      Nilsen, Aud Solveig; Stakkeland, Linda Marie (Conference object; Konferansebidrag, 2021-09)
      Some crisis have an international impact. How is it possible to enhance collaboration between nations in huge and cascading disasters? We will present Barents Rescue (BR) as an inspiration for our Student Barents Rescue (SBR) and thereafter show examples from a student pilot with an international scenario.
    • How and why develop scenarios for training students to use their knowledge in practice? 

      Nilsen, Aud Solveig (Conference object; Konferansebidrag, 2021-09)
      To be able to handle crisis and risks there is a need for different skills. We will focus on learning by combining theory and practice. Since NEEDS is a disaster management community, scenarios in line with this theme are wanted.<p> <p>This colloquium can be an experience transfer between educators that work with scenario-based training and want to develop this further. Drawing on different ...