Now showing items 821-840 of 5364

    • Analyzing the Impact of Peak-Shaving on Load Reduction and on Battery Energy Storage System Degradation: A Simulation-Based Study in Husøy 

      Kournoutis, Georgios (Mastergradsoppgave; Master thesis, 2023-11-14)
      The island of Husøy, in Northern Senja, Norway, faces numerous voltage quality difficulties, which arise from the consequent surge in electricity demand by the local growing fishing industry. Collaborating with the local distribution system operator (DSO), Arva, the current study explores the implementation of Battery Energy Storage Systems (BESS) using a peak-shaving strategy to alleviate high-demand ...
    • Toward a Collaborative Platform for Hybrid Designs Sharing a Common Cohort 

      Arnes, Jo Inge (Doctoral thesis; Doktorgradsavhandling, 2024-01-18)
      <p>This doctoral thesis binds together four included papers in a thematical whole and is simultaneously an independent work proposing a platform facilitating epidemiological research. <p><i>Population-based prospective cohort studies</i> typically recruit a relatively large group of participants representative of a studied population and follow them over years or decades. This group of participants ...
    • Local Seismicity and Sediment Deformation in the West Svalbard Margin: Implications of Neotectonics for Seafloor Seepage 

      Domel, Przemyslaw; Plaza Faverola, Andreia Aletia; Schlindwein, Vera; Bünz, Stefan (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-12)
      In the Fram Strait, mid-ocean ridge spreading is represented by the ultra-slow system of the Molloy Ridge, the Molloy Transform Fault and the Knipovich Ridge. Sediments on oceanic and continental crust are gas charged and there are several locations with documented seafloor seepage. Sedimentary faulting shows recent stress release in the sub-surface, but the drivers of stress change and its influence ...
    • Towards high-throughput screening (HTS) of polyhydroxyalkanoate (PHA) production via Fourier transform infrared (FTIR) spectroscopy of Halomonas sp. R5-57 and Pseudomonas sp. MR4-99 

      Christensen, Mikkel; Chiciudean, Iulia; Jablonski, Piotr; Tănase, Ana-Maria; Shapaval, Volha; Hansen, Hilde (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-08)
    • On Measures of Uncertainty in Classification 

      Chlaily, Saloua; Ratha, Debanshu; Lozou, Pigi; Marinoni, Andrea (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-12)
      Uncertainty is unavoidable in classification tasks and might originate from data (e.g., due to noise or wrong labeling), or the model (e.g., due to erroneous assumptions, etc). Providing an assessment of uncertainty associated with each outcome is of paramount importance in assessing the reliability of classification algorithms, especially on unseen data. In this work, we propose two measures of ...
    • Interplay between advective, diffusive and active barriers in (rotating) Rayleigh-Bénard flow 

      Aksamit, Nikolas Olson; Hartmann, Robert; Lohse, Detlef; Haller, George (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-22)
      Our understanding of the material organization of complex fluid flows has benefited recently from mathematical developments in the theory of objective coherent structures. These methods have provided a wealth of approaches that identify transport barriers in three-dimensional (3-D) turbulent flows. Specifically, theoretical advances have been incorporated into numerical algorithms that extract ...
    • Simultaneous Global Ionospheric Disturbances Associated With Penetration Electric Fields During Intense and Minor Solar and Geomagnetic Disturbances 

      Zhang, Shun-Rong; Nishimura, Yukitoshi; Vierinen, Juha-Pekka; Lyons, Larry R.; Knipp, Delores J.; Gustavsson, Björn Johan; Waghule, Bhagyashree V.; Erickson, Philip J.; Coster, Anthea J.; Aa, Ercha; Spicher, Andres (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-29)
      A new observational phenomenon, named Simultaneous Global Ionospheric Density Disturbance (SGD), is identified in GNSS total electron content (TEC) data during periods of three typical geospace disturbances: a Coronal Mass Ejection-driven severe disturbance event, a high-speed stream event, and a minor disturbance day with a maximum Kp of 4. SGDs occur frequently on dayside and dawn sectors, with ...
    • The effect of a water-ice mantle on dust trajectories in the Kuiper belt 

      Gjelsvik, Amalie (Mastergradsoppgave; Master thesis, 2023-07-12)
      The New Horizons spacecraft has travelled through the Solar System and has reached a distance of 55 AU as of 2023. For one of the first times, the dust flux in the outer Solar System has been measured, using the instrument Student Dust Counter (SDC) onboard New Horizons. Between 30 and 50 AU is the Kuiper belt, which is a disk consisting of icy objects. These objects can undergo collisions, causing ...
    • Revisiting the ‘Whys’ and ‘Hows’ of the Warm-Up: Are We Asking the Right Questions? 

      Afonso, José; Brito, João; Abade, Eduardo; Rendeiro-Pinho, Gonçalo; Matias Do Vale Baptista, Ivan Andre; Figueiredo, Pedro; Nakamura, Fábio Yuzo (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-02)
      The warm-up is considered benefcial for increasing body temperature, stimulating the neuromuscular system and overall preparing the athletes for the demands of training sessions and competitions. Even when warm-up–derived benefts are slight and transient, they may still beneft preparedness for subsequent eforts. However, sports training and competition performance are highly afected by contextual ...
    • A deep learning approach for anomaly identification in PZT sensors using point contact method 

      Kalimullah, Nur M M; Shelke, Amit; Habib, Anowarul (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-21)
      The implementation of piezoelectric sensors is degraded due to surface defects, delamination, and extreme weathering conditions, to mention a few. Hence, the sensor needs to be diagnosed before the efficacious implementation in the structural health monitoring (SHM) framework. To rescue the problem, a novel experimental method based on Coulomb coupling is utilised to visualise the evolution of ...
    • Investigating Spatial and Temporal Structuring of E-Region Coherent Scattering Regions Over Northern Norway 

      Huyghebaert, Devin Ray; Chau, Jorge L.; Spicher, Andres; Ivarsen, Magnus Fagernes; Clahsen, Matthias; Latteck, Ralph; Vierinen, Juha-Pekka (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-26)
      Recently, it has been shown that the Spread Spectrum Interferometric Multistatic meteor radar Observing Network radar system located in northern Norway is capable of measuring ionospheric E-region coherent scatter with spatial and temporal resolutions on the order of 1.5 km and 2 s, respectively. Four different events from June and July of 2022 are examined in the present study, where the coherent ...
    • Elevated methane alters dissolved organic matter composition in the Arctic Ocean cold seeps 

      Sert, Muhammed Fatih; Schweitzer, Hannah; de Groot, Tim R.; Kekäläinen, Timo; Jänis, Janne; Bernstein, Hans Christopher; Ferré, Benedicte; Gründger, Friederike; Kalenitchenko, Dimitri Stanislas Desire; Niemann, Helge (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-15)
      Cold seeps release methane (CH<sub>4</sub>) from the seafloor to the water column, which fuels microbially mediated aerobic methane oxidation (MOx). Methane-oxidising bacteria (MOB) utilise excess methane, and the MOB biomass serves as a carbon source in the food web. Yet, it remains unclear if and how MOx modifies the composition of dissolved organic matter (DOM) in cold seeps. We investigated MOx ...
    • Effects of subglacial meltwater runoff on the ocean circulation beneath the Filchner Ice Shelf 

      Hus, Johanne Jahnsen (Mastergradsoppgave; Master thesis, 2023-06-15)
      Antarctic ice shelves, by restraining ice streams and affecting the discharge of grounded ice, play a critical role in the mass balance of the Antarctic ice sheet. In this study, sub-ice shelf CTD measurements and time series data from an ice shelf cavity mooring were used to detect subglacial runoff beneath the Filchner Ice Shelf. CTD measurements from four boreholes across the southern Filchner ...
    • On the Linkage Between Rossby Waves and Heatwaves 

      Petříček, Jakub (Mastergradsoppgave; Master thesis, 2023-05-14)
      This thesis examines the relationship between upper-level atmospheric circulation and heatwaves. We studied the role of planetary Rossby waves in the observed increase in intensity, frequency, and duration of extreme temperature events in the mid-latitudes. Focusing on the summer season, we tested the proposed hypothesis that links recent changes in the Rossby wave amplitudes and propagation speed ...
    • Science goals for a high-frequency radar and radio imaging array 

      Isham, Brett Cameron; Bullett, Terence; Gustavsson, Björn Johan; Polisensky, Emil; Brum, Christiano; Fallen, Christopher; Belyey, Vasyl; Parra-Rojas, Francisco; Norouzi, Leila; Stramkals, Arturs; Ökten, Mehmet Baran (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-01)
      A medium and high-frequency antenna array for radar and radio imaging of the ionosphere is planned for installation in Aguadilla, Puerto Rico. Science goals include the study of space weather, radio propagation, meteors, lightning, and plasma physics. Radio imaging is ideal for the study of stimulated ionospheric radio emissions, such as those induced by the Arecibo Observatory high-power HF radio ...
    • A finite volume flux coordinate independent approach 

      Wiesenberger, Matthias; Held, Markus (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-03)
      We present a novel family of schemes as the merging between a one-dimensional advection scheme with the flux coordinate independent approach. The scheme can be used to discretize the field-aligned NavierStokes equations in three dimensions. Our approach consists of three major steps: (i) the formulation of the one-dimensional scheme in a locally field-aligned coordinate system, (ii) a numerical ...
    • Coordinate Conversion and Switching Correction to Reduce Vessel Heading-Related Errors in High-Latitude Navigation 

      Wang, Yufei; Perera, Lokukaluge Prasad Channa; Batalden, Bjørn-Morten Erdal (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-22)
      Considering the distortion errors of projected coordinates and the switching property of vessel heading, coordinate conversion and switching correction methods are proposed to modify a kinematic motion model and the Unscented Kalman Filter (UKF). The coordinate conversion method utilizes the grid convergence from a Universal Transverse Mercator (UTM) projection to correct the vessel heading. The ...
    • Tanning Wastewater Sterilization in the Dark and Sunlight Using Psidium guajava Leaf-Derived Copper Oxide Nanoparticles and Their Characteristics 

      Lakshmaiya, Natrayan; Surakasi, Raviteja; Nadh, V. Swamy; Srinivas, Chidurala; Kaliappan, Seniappan; Ganesan, Velmurugan; Paramasivam, Prabhu; Dhanasekaran, Seshathiri (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-09)
      Employing Psidium guajava (P. guajava) extract from leaves, copper oxide nanoparticles (CuO NPs), likewise referred to as cupric oxide and renowned for their sustainable and harmless biogenesis, have the possibility of being useful for the purification of pollutants as well as for medicinal purposes. The current study examined the generated CuO NPs and their physical qualities by using ultraviolet−visible ...
    • The transition from normal marine to evaporitic conditions recorded in a cold seep environment: The Messinian succession of Northern Italy 

      Conti, S.; Argentino, Claudio; Bojanowski, M.; Fioroni, C.; Giunti, S.; Kremer, B.; Fontana, D. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-26)
      Messinian pre-evaporitic seep carbonates outcropping in the Tuscan-Romagna area share a common upward stratigraphic trend: massive seep carbonates rich in large lucinids, modiolids and planktonic foraminifera pass upward to horizontally laminated carbonates free of macrofauna and foraminifera. A transitional macrofauna-free facies marks the passage in some sections, sometimes with faint lamination. ...
    • The Stepwise Reduction of Multiyear Sea Ice Area in the Arctic Ocean Since 1980 

      Babb, D.G.; Galley, R.J.; Kirillov, S.; Landy, Jack Christopher; Howell, S.E.L.; Stroeve, J.C.; Meier, W.; Ehn, J.K.; Barber, D.G. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-28)
      The loss of multiyear sea ice (MYI) in the Arctic Ocean is a significant change that affects all facets of the Arctic environment. Using a Lagrangian ice age product, we examine MYI loss and quantify the annual MYI area budget from 1980 to 2021 as the balance of export, melt, and replenishment. Overall, MYI area declined at 72,500 km<sup>2</sup> /yr; however, a majority of the loss occurred ...