Viser treff 3061-3080 av 5336

    • Role of hafnium doping concentration on the structural and surface properties of ZnO surfaces 

      Moser, Toni (Master thesis; Mastergradsoppgave, 2019-05-31)
      The presented thesis deals with the characterisation of hafnium doped zinc oxides with focus on the application as transparent conducting film (TCF) or electron transport layer (ETL) in heterojunction solar cells. Atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electrical and optical methods have been applied to characterise the examined ...
    • A Comparison of Naturally Enhanced Ion Acoustic Lines and Auroral Spectral Line Emissions 

      Hansen, Rikke Hedelund (Master thesis; Mastergradsoppgave, 2019-05-31)
      In this thesis, we present Naturally Enhanced Ion Acoustic Lines (NEIALs) observed with the EISCAT Svalbard Radar and a comparison with auroral emissions lines measured with a Meridian Scanning Photometer. NEIALs are short-lived events noticeable in the incoherent scatter spectra as an enhancement in one or both shoulders. It has been assumed that NEIALs are associated with an active red emission ...
    • Vurdering av naturvitskapleg prosess og metode på ungdomstrinnet. Ein kvalitativ studie av elevar si oppfatning og gjennomføring av utforskande oppgåver relatert til naturfaget sin prosessdimensjon. 

      Espe, Oda Kristin (Master thesis; Mastergradsoppgave, 2019-05-31)
      Utforskande arbeidsmåtar er eit resultat av naturvitskapleg tradisjon, og synleggjer naturfaget sin prosessdimensjon. Føremålet med studien var utvikling og pilotering av ei fagprøve i naturfag på 8.trinn. Dette gav opphav til problemstillinga: "På kva måte gjennomfører og opplever elevar på ungdomstrinnet utforskande oppgåver som stiller krav til naturvitskapleg prosess?" Studien ønska samt å ...
    • Full‐length 16S rRNA gene classification of Atlantic salmon bacteria and effects of using different 16S variable regions on community structure analysis 

      Klemetsen, Terje; Willassen, Nils Peder; Karlsen, Christian René (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-04)
      Understanding fish‐microbial relationships may be of great value for fish producers as fish growth, development and welfare are influenced by the microbial community associated with the rearing systems and fish surfaces. Accurate methods to generate and analyze these microbial communities would be an important tool to help improve understanding of microbial effects in the industry. In this study, ...
    • Validity of the Polar M430 Activity Monitor in Free-Living Conditions: Validation Study 

      Henriksen, André; Grimsgaard, Sameline; Horsch, Alexander; Hartvigsen, Gunnar; Hopstock, Laila Arnesdatter (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-16)
      <i>Background</i>: Accelerometers, often in conjunction with heart rate sensors, are extensively used to track physical activity (PA) in research. Research-grade instruments are often expensive and have limited battery capacity, limited storage, and high participant burden. Consumer-based activity trackers are equipped with similar technology and designed for long-term wear, and can therefore ...
    • A red tide in the pack ice of the Arctic Ocean 

      Olsen, Lasse Mork; Duarte, Pedro; Peralta-Ferriz, Cecilia; Kauko, Hanna Maria; Johansson, Malin; Peeken, Ilka; Różańska-Pluta, Magdalena; Tatarek, Agnieszka; Wiktor, Jozef; Fernández-Méndez, Mar; Wagner, Penelope Mae; Pavlov, Alexey K.; Hop, Haakon; Assmy, Phillipp (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-02)
      In the Arctic Ocean ice algae constitute a key ecosystem component and the ice algal spring bloom a critical event in the annual production cycle. The bulk of ice algal biomass is usually found in the bottom few cm of the sea ice and dominated by pennate diatoms attached to the ice matrix. Here we report a red tide of the phototrophic ciliate <i>Mesodinium rubrum</i> located at the ice-water interface ...
    • A 160,000-year-old history of tectonically controlled methane seepage in the Arctic 

      Himmler, Tobias; Sahy, Diana; Martma, Tõnu; Bohrmann, Gerhard; Plaza-Faverola, Andreia; Bünz, Stefan; Condon, Daniel J.; Knies, Jochen; Lepland, Aivo (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-07)
      The geological factors controlling gas release from Arctic deep-water gas reservoirs through seabed methane seeps are poorly constrained. This is partly due to limited data on the precise chronology of past methane emission episodes. Here, we use uranium-thorium dating of seep carbonates sampled from the seabed and from cores drilled at the Vestnesa Ridge, off West Svalbard (79°N, ~1200 m water ...
    • Improved CRISPR/Cas9 gene editing by fluorescence activated cell sorting of green fluorescence protein tagged protoplasts 

      Petersen, Bent Larsen; Möller, Svenning Rune; Mravec, Jozef; Jørgensen, Bodil; Christensen, Mikkel; Liu, Ying; Wandall, Hans H.; Bennett, Eric Paul; Yang, Zhang (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-17)
      <i>Background</i>: CRISPR/Cas9 is widely used for precise genetic editing in various organisms. CRISPR/Cas9 editing may in many plants be hampered by the presence of complex and high ploidy genomes and inefficient or poorly controlled delivery of the CRISPR/Cas9 components to gamete cells or cells with regenerative potential. Optimized strategies and methods to overcome these challenges are ...
    • Homogeneous integrable Legendrian contact structures in dimension five 

      Doubrov, Boris; Medvedev, Alexandr; The, Dennis (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-04)
      We consider Legendrian contact structures on odd-dimensional complex analytic manifolds. We are particularly interested in integrable structures, which can be encoded by compatible complete systems of second order PDEs on a scalar function of many independent variables and considered up to point transformations. Using the techniques of parabolic differential geometry, we compute the associated ...
    • Dust trajectory simulations around Sun, Vega, and Fomalhaut 

      Stamm, Johann Immanuel; Czechowski, Andrzej; Mann, Ingrid; Baumann, Carsten; Myrvang, Margaretha (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-20)
      <p><i>Context - </i>Vega and Fomalhaut display a thermal emission brightness that can possibly arise from hot dust near the stars, an inner extension of their planetary debris disks. There was brought up an idea that nm-sized dust particles are kept in the vicinity of the stars by electromagnetic forces. This resembles the trapping that model calculations show in the corotating magnetic field in the ...
    • Fully Polarizable QM/Fluctuating Charge Approach to Two-Photon Absorption of Aqueous Solutions 

      Di Remigio, Roberto; Giovannini, Tommaso; Ambrosetti, Matteo; Cappelli, Chiara; Frediani, Luca (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-05)
      We present the extension of the quantum/classical polarizable fluctuating charge model to the calculation of single residues of quadratic response functions, as required for the computational modeling of two-photon absorption cross sections. By virtue of a variational formulation of the quantum/classical polarizable coupling, we are able to exploit an atomic orbital-based quasienergy formalism to ...
    • Anticlockwise metamorphic pressure–temperature paths and nappe stacking in the Reisa Nappe Complex in the Scandinavian Caledonides, northern Norway: evidence for weakening of lower continental crust before and during continental collision 

      Faber, Carly; Stunitz, Holger; Gasser, Deta; Jeřábek, Petr; Kraus, Katrin; Corfu, Fernando; Ravna, Erling Krogh; Konopásek, Jiří (Journal article; Tidsskriftartikkel; Peer reviewed, 2019)
      This study investigates the tectonostratigraphy and metamorphic and tectonic evolution of the Caledonian Reisa Nappe Complex (RNC; from bottom to top: Vaddas, Kåfjord, and Nordmannvik nappes) in northern Troms, Norway. Structural data, phase equilibrium modelling, and U-Pb zircon and titanite geochronology are used to constrain the timing and pressure–temperature (<i>P–T</i>) conditions of deformation ...
    • The Origin of Gas Seeps in the Northern Adriatic Sea 

      Donda, Federica; Tinivella, Umberta; Gordini, Emiliano; Panieri, Giuliana; Volpi, Valentina; Civile, Dario; Forlin, Edy; Facchin, Lorenzo; Burca, Mihai; Cova, Andrea; Ferrante, Giulia M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06)
      A multidisciplinary approach has been used for the first time to study the widespread occurrence of hydrocarbon seeps in the northern Adriatic Sea. Geological, geophysical and geochemical analyses were performed to identify and characterize the gas-charged fluids occurring throughout the Plio-Quaternary succession, and to date the shallow gas seeping at three leakage sites. The analysis of CHIRP, ...
    • All-electron fully relativistic Kohn-Sham theory for solids based on the Dirac-Coulomb Hamiltonian and Gaussian-type functions 

      Kadek, Marius; Repisky, Michal; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-03)
      We present the first full-potential method that solves the fully relativistic four-component Dirac-Kohn-Sham equation for materials in the solid state within the framework of atom-centered Gaussian-type orbitals (GTOs). Our GTO-based method treats one-, two-, and three-dimensional periodic systems on an equal footing, and allows for a seamless transition to the methodology commonly used in studies ...
    • Palaeoceanographic reconstruction of surface-ocean changes in the southern Norwegian Sea for the last ~130,000 years based on diatoms and with comparison to foraminiferal records 

      Hoff, Ulrike; Rasmussen, Tine Lander; Meyer, Hanno; Koc, Nalan; Hansen, Jesper (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-28)
      Fossil marine diatom assemblages in a sediment core from the central northern Faroe slope in the Norwegian Sea were used to reconstruct palaeoceanographic changes in the surface water mixed layer from the last ~130,000 years (Marine Isotope Stage (MIS) 6/5 transition to MIS 1 (including the Eemian and Holocene interglacials) and to compare the results with previously published results on planktic ...
    • Morphological evidence for marine ice stream shutdown, central Barents Sea 

      Kurjanski, Bartosz; Rea, Brice R.; Spagnolo, Matteo; Winsborrow, Monica; Cornwell, David G.; Andreassen, Karin; Howell, John (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-02)
      Marine-based ice streams are responsible for a significant proportion of the ice mass loss from the present-day Greenland Ice Sheet, East Antarctic Ice Sheet (EAIS) and West Antarctic Ice Sheet (WAIS) but the processes controlling their initiation, evolution and shutdown remain elusive, hindering our understanding of how existing ice masses will respond to predicted future warming. The exposed beds ...
    • Reviewing the Cenozoic Net Erosion of the Barents Sea Shelf 

      Lasabuda, Amando Putra Ersaid; Laberg, Jan Sverre; Knutsen, Stig-Morten; Rydningen, Tom Arne (Conference object; Konferansebidrag, 2019-01)
    • Detection of meteoroid hypervelocity impacts on the Cluster spacecraft: First results 

      Vaverka, Jakub; Pellinen-Wannberg, Asta; Kero, Johan; Mann, Ingrid; De Spiegeleer, Alexandre; Hamrin, Maria; Norberg, Carol; Pitkaenen, Timo (Journal article; Peer reviewed, 2017-06-29)
      We present the first study of dust impact events on one of the Earth‐orbiting Cluster satellites. The events were identified in the measurements of the wide band data (WBD) instrument on board the satellite operating in monopole configuration. Since 2009 the instrument is operating in this configuration due to the loss of three electric probes and is therefore measuring the potential between the ...
    • Response properties of embedded molecules through the polarizable embedding model 

      Steinmann, Casper; Reinholdt, Peter; Nørby, Morten Steen; Kongsted, Jacob; Olsen, Jógvan Magnus Haugaard (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-04)
      The polarizable embedding (PE) model is a fragment‐based quantum‐classical approach aimed at accurate inclusion of environment effects in quantum‐mechanical response property calculations. The aim of this tutorial review is to give insight into the practical use of the PE model. Starting from a set of molecular structures and until you arrive at the final property, there are many crucial details to ...
    • Evidence of Isotopic Fractionation During Vapor Exchange Between the Atmosphere and the Snow Surface in Greenland 

      Madsen, M.V.; Steen‐Larsen, H.C.; Hörhold, M.; Box, J.; Berben, Sarah Miche Patricia; Capron, E.; Faber, Anne-Katrine; Hubbard, Alun Lloyd; Jensen, Mari Fjalstad; Jones, T.R.; Kipfstuhl, S.; Koldtoft, I.; Pillar, H.R.; Vaughn, B.H.; Vladimirova, D.; Dahl‐Jensen, D. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-18)
      Several recent studies from both Greenland and Antarctica have reported significant changes in the water isotopic composition of near‐surface snow between precipitation events. These changes have been linked to isotopic exchange with atmospheric water vapor and sublimation‐induced fractionation, but the processes are poorly constrained by observations. Understanding and quantifying these processes ...