Viser treff 339-358 av 4765

    • The Beauty of Complex Designs 

      Arnes, Jo Inge; Bongo, Lars Ailo (Chapter; Bokkapittel, 2020-12-08)
      The increasing use of omics data in epidemiology enables many novel study designs, but also introduces challenges for data analysis. We describe the possibilities for systems epidemiological designs in the Norwegian Women and Cancer (NOWAC) study and show how the complexity of NOWAC enables many beautiful new study designs. We discuss the challenges of implementing designs and analyzing data. Finally, ...
    • BedMachine v3: Complete bed topography and ocean bathymetry mapping of Greenland from multi-beam echo sounding combined with mass conservation 

      Morlighem, Mathieu; Williams, Chris N.; Rignot, Eric J.M.; An, Lu; Arndt, Jan Erik; Bamber, Jonathan L.; Catania, Ginny A.; Chauché, Nolwenn; Dowdeswell, Julian A.; Dorschel, Boris; Fenty, Ian; Hogan, Kelly A.; Howat, Ian M.; Hubbard, Alun Lloyd; Jakobsson, Martin; Jordan, Thomas M.; Kjeldsen, Kristian Kjellerup; Millan, Romain; Mayer, Larry; Mouginot, Jérémie; Noël, Brice P.Y.; O'Cofaigh, Colm; Palmer, Steven; Rysgaard, Søren; Seroussi, Hélène; Siegert, Martin J.; Slabon, Patricia; Straneo, Fiamma; van den Broeke, Michiel R.; Weinrebe, Wilhelm Reimer; Wood, Michael; Zinglersen, Karl Brix (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-09-18)
      Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts and undercuts Greenland's marine‐terminating glaciers. Here we present a new compilation of Greenland bed topography that assimilates seafloor bathymetry and ice thickness ...
    • Begrepslæring i naturfag: En kvalitativ casestudie av en lærers strategier for å fremme læring av kjemifaglige begreper i ungdomskolen 

      Arneberg, Siri Outzen (Master thesis; Mastergradsoppgave, 2021-10-30)
      Denne masteroppgaven er skrevet med interesse for lærerrollen og fagformidling som utgangspunkt. Oppgaven har som hensikt å øke leserens bevissthet rundt det fagspesifikke språket i naturfag, og hvilken konsekvens dette språket har for læring i naturfag. Det er også et ønske at oppgaven kan være et didaktisk bidrag til hvordan man kan legge til rette for elevenes fagspråklige utvikling, og følgelig ...
    • The behavior of electron density and temperature during ionospheric heating near the fifth electron gyrofrequency 

      Wu, Jun; Wu, Jian; Rietveld, Michael T.; Häggström, I.; Zhao, Haisheng; Xu, Zhengwen (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-01-27)
      The experimental phenomena involving the changes in electron temperature and electron density as a function of pump frequency during an ionospheric heating campaign at European Incoherent Scatter near Tromsø, Norway, are reported. When the pump frequency is slightly above the fifth electron gyrofrequency, the UHF radar observation shows some apparent enhancements over a wide altitude range in radar ...
    • Behavioral and energetic response of Arctic-breeding seabirds to environmental variability. 

      Welcker, Jorg (Doctoral thesis; Doktorgradsavhandling, 2009-06-16)
      Knowledge about the extent to which organisms inhabitating the Arctic are able to adjust to environmental variability is essential in order to predict the impact of future climate change. In this context, the flexibility og two Acrtic-breeding seabirds, the little Auk (Alle alle) and the kittiwake (Rissa tridactyla), in foraging behavior and energy expenditure in response to environmental variability. ...
    • Behavioural change in green transportation: Micro-economics perspectives and optimization strategies 

      Bordin, Chiara; Tomasgard, Asgeir (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-22)
      The increasing demand for Electric Vehicle (EV) charging is putting pressure on the power grids and capacities of charging stations. This work focuses on how to use indirect control through price signals to level out the load curve in order to avoid the power consumption from exceeding these capacities. We propose mathematical programming models for the indirect control of EV charging that aim at ...
    • Behind the scenes of spin-forbidden decay pathways in transition metal complexes 

      Moitra, Torsha; Karak, Pijush; Chakraborty, Sayantani; Ruud, Kenneth; Chakrabarti, Swapan (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-10)
      The interpretation of the ultrafast photophysics of transition metal complexes following photo-absorption is quite involved as the heavy metal center leads to a complicated and entangled singlet–triplet manifold. This opens up multiple pathways for deactivation, often with competitive rates. As a result, intersystem crossing (ISC) and phosphorescence are commonly observed in transition metal complexes. ...
    • Benchmarking the Performance of Exchange-Correlation Functionals for Predicting Two-Photon Absorption Strengths 

      Beerepoot, Maarten; Alam, MD Mehboob; Bednarska, Joanna; Bartkowiak, Wojciech; Ruud, Kenneth; Zaleśny, Robert (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-31)
      The present work investigates the performance of exchange–correlation functionals in the prediction of two-photon absorption (2PA) strengths. For this purpose, we considered six common functionals used for studying 2PA processes and tested these on six organoboron chelates. The set consisted of two semilocal (PBE and BLYP), two hybrid (B3LYP and PBE0), and two range-separated (LC-BLYP and CAM-B3LYP) ...
    • Benchmarking two-photon absorption cross sections: performance of CC2 and CAM-B3LYP 

      Beerepoot, Maarten T. P.; Friese, Daniel Henrik; List, Nanna Holmgaard; Kongsted, Jacob; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06-25)
      We investigate the performance of CC2 and TDDFT/CAM-B3LYP for the calculation of two-photon absorption (TPA) strengths and cross sections and contrast our results to a recent coupled cluster equation-of-motion (EOM-EE-CCSD) benchmark study [K. D. Nanda and A. I. Krylov, J. Chem. Phys., 2015, 142, 064118]. In particular, we investigate whether CC2 TPA strengths are significantly overestimated compared ...
    • Beneath the snow – Developing a wireless sensor node for remote locations in the Arctic 

      Tveito, Øystein (Master thesis; Mastergradsoppgave, 2020-05-15)
      In this thesis we describe how we designed, built, deployed, and improved upon a robust hardware- and software solution, tailor-made to this scientific question. During the course of this project, we created three distinct versions and we have conducted two deployments of the sensor nodes in the Arctic tundra. The node is able to measure CO2 , temperature, and humidity, in addition to monitoring an ...
    • Benthic communities at high-Arctic cold seeps: Faunal response to methane seepage in Svalbard 

      Åström, Emmelie (Doctoral thesis; Doktorgradsavhandling, 2018-03-20)
      Cold seeps are chemosynthetic habitats found in both deep sea and shallow ocean-shelves worldwide, including the polar regions. At seeps, hydrocarbons, sulfide, and other reduced compounds emerge from the seafloor, providing energy to fuel chemoautotrophic production. Microbial assemblages, supported by the oxidation and reduction of gases and fluids, form the base of a food web composing unique and ...
    • Benthic foraminifera as bio-indicators of chemical and physical stressors in Hammerfest harbor (Northern Norway) 

      Dijkstra, Noortje; Junttila, Juho; Skirbekk, Kari; Carroll, JoLynn; Husum, Katrine; Hald, Morten (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-10-01)
      We investigated benthic foraminiferal assemblages in contaminated sediments in a subarctic harbor of northern Norway to assess their utility as indicators of anthropogenic impacts. Sediments in the harbor are repositories for POPs and heavy metals supplied through discharges from industry and shipping activities. Sediment contaminant concentrations are at moderate to poor ecological quality ...
    • Benthic foraminifera as indicators of natural variability and anthropogenic impact 

      Dijkstra, Noortje (Doctoral thesis; Doktorgradsavhandling, 2013-11-28)
      Benthic foraminifera (micro-organism living on the sea-floor) were studied in the southwestern Barents Sea and Hammerfest harbor. The study focused on the response of the micro-organisms to natural and man made environmental changes. The study shows that the southwestern Barents sea is relatively clean, and the foraminifera are only impacted by natural changes. However, in the Hammerfest harbor, ...
    • Benthic foraminifera in an Arctic fjord : recent distribution and fauna of the last two millennia 

      Jernas, Patrycja Ewa (Doctoral thesis; Doktorgradsavhandling, 2012-09-13)
      The main objective of the PhD study was to improve the knowledge about the ecology of the benthic foraminiferal faunas thus increasing the precision of benthic foraminifera as indicators for modern and past Arctic fjord and shelf environments. The investigation of living (stained) benthic foraminifera assemblages in Kongsfjorden (western Svalbard) was performed on inter-annual and seasonal time ...
    • Benthic Foraminifera in Arctic Methane Hydrate Bearing Sediments 

      Dessandier, Pierre-Antoine; Borrelli, Chiara; Kalenitchenko, Dimitri; Panieri, Giuliana (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-10)
      Benthic foraminifera have been widely used as proxy for paleo-methane emissions, mainly based on their stable isotopic signature. In cold seeps, the ecology of these organisms remains uncertain, in particular their ability to thrive during active phases of seepage. In this study, we evaluate the benthic foraminiferal response to methane seepage in Arctic sediments. We do so by examining living and ...
    • 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 ...
    • Benthic foraminiferal growth seasons implied from Mg/Ca-temperature correlations for three Arctic species 

      Skirbekk, Kari; Hald, Morten; Thomas Jr., Marchitto; Junttila, Juho; Klitgaard Kristensen, Dorthe; Sørensen, Steffen Aagaard (Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-11-22)
      Core-top sediment samples from Kongsfjorden, Svalbard, and adjacent fjord and shelf areas were collected in order to investigate a potential relationship between Mg/Ca-ratios of Arctic benthic foraminifera and the ambient bottom water temperatures (BWT). The area is influenced by large seasonal variation in factors such as light and temperature, which is further strengthened by oceanographic shifts, ...
    • Benthic foraminiferal investigations in Middle to Late Quaternary sections of Kongsfjordhallet, north-west Svalbard 

      Chatterjee, Debolina; Ghosh, Anupam; Alexanderson, Helena (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-29)
      Stratigraphic sites in north-west Svalbard record at least six significant glacial advances in the last 200 Ky, and sediments deposited under locally high relative sea level during intervening interstadials or interglacials contain abundant benthic foraminifera. We present a biostratigraphic record from the Kongsfjordhallet site in the Kongsfjorden area that covers five high relative sea-level events ...
    • The benthic foraminiferal δ34S records fux and timing of paleo methane emissions 

      Borrelli, Chiara; Gabitov, R.I.; Liu, M.-C.; Hertwig, A.T.; Panieri, Giuliana (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-28)
      In modern environments, pore water geochemistry and modelling simulations allow the study of methane (CH<sub>4</sub>) sources and sinks at any geographic location. However, reconstructing CH<sub>4</sub> dynamics in geological records is challenging. Here, we show that the benthic foraminiferal δ<sup>34</sup>S can be used to reconstruct the fux (i.e., difusive vs. advective) and timing of CH<sub>4</sub> ...
    • Beskyttelse av sensitiv informasjon; En studie av norske nettselskapers beskyttelse av sensitiv informasjon. 

      Kruke, Marta Helene Eskeland (Master thesis; Mastergradsoppgave, 2017-06-01)
      I dag tar de fleste tilgangen til strøm for gitt. Vi forventer at komfyren skal fungere når vi lager middag, at det er varmt vann i dusjen og at lyset tennes når vi trykker på bryteren (Statnett, 2014, 28.11). Nettselskapene i Norge jobber for å opprettholde en sikker og stabil strømforsyning. Dette arbeidet inkluderer beskyttelse av sensitiv informasjon, altså opplysninger om energiforsyningen som ...