Viser treff 1237-1256 av 1261

    • Waveguide asymmetric long-period grating couplers as refractive index sensors 

      Høvik, Jens; Yadav, Mukesh; Noh, Jong Wook; Aksnes, Astrid (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-29)
      A highly sensitive integrated photonic transducer is designed by utilizing asymmetric long-period gratings on a silicon waveguide. These gratings are formed by periodic perturbation of the waveguide width, leading to coupling between the fundamental mode and the 1st order asymmetric leaky mode. The coupled modes are studied via finite-element and finite-difference time-domain methods. Only a single ...
    • A waveguide imaging platform for live-cell TIRF imaging of neurons over large fields of view 

      Opstad, Ida Sundvor; Ströhl, Florian; Fantham, Marcus J.; Hockings, Colin; Vanderpoorten, Oliver; Tartwijk, Francesca W. van; Qiaojin Lin, Julie; Tinguely, Jean-Claude; Dullo, Firehun Tsige; Kaminski‐Schierle, Gabriele S.; Ahluwalia, Balpreet Singh; Kaminski, Clemens F. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-17)
      Large fields of view (FOVs) in total internal reflection fluorescence microscopy (TIRFM) via waveguides have been shown to be highly beneficial for single molecule localisation microscopy on fixed cells [1,2] and have also been demonstrated for short‐term live‐imaging of robust cell types [3‐5], but not yet for delicate primary neurons nor over extended periods of time. Here, we present a waveguide‐based ...
    • The weakening AMOC under extreme climate change 

      Madan, Gaurav; Gjermundsen, Ada; Iversen, Silje Christine; Lacasce, Joseph Henry (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-06)
      Changes in the Atlantic Meridional Overturning Circulation (AMOC) in the quadrupled CO<sub>2</sub> experiments conducted under the sixth Coupled Model Intercomparison Project (CMIP6) are examined. Increased CO<sub>2</sub> triggers extensive Arctic warming, causing widespread melting of sea ice. The resulting freshwater spreads southward, frst from the Labrador Sea and then the Nordic Seas, and ...
    • Weather situation during observed ship-icing events off the coast of Northern Norway and the Svalbard archipelago 

      Samuelsen, Eirik Mikal; Graversen, Rune (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-19)
      Ship icing may lead the ship and crew in great jeopardy. Usually, predictions of such ice build-up are based on the modelling of the heat fluxes capable of freezing sea water originated from wave-ship interactions. This study, on the other hand, follows a different and more general approach by investigating the relationship between the weather situation and icing both using observed parameters from ...
    • Wet snow detection by C-band SAR in avalanche forecasting 

      Hopsø, Ingrid Strømsvik (Master thesis; Mastergradsoppgave, 2013-12-15)
      Avalanches usually occur in steep, snow-covered mountain sides under special conditions. The stability of the snowpack depends, among other things, on the melting and freezing of the snowpack. If a snow covered area has not undergone a melt/freeze-process, it could potentially be unstable due to depth hoar or buried layers of frost, and therefore pose an avalanche risk if the area is located at a ...
    • What is going on with Middle Eastern solar prices, and what does it mean for the rest of us? 

      Apostoleris, Harry; Al Ghaferi, Amal; Chiesa, Matteo (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-04)
      For the third time in a decade, solar energy pricing records are tumbling in the Persian Gulf. As each previous wave of new records was met with incredulity, only for these prices to become the new normal around the world within a few years, it would be unwise to once again dismiss low prices as unrepresentative outliers. In this study, we show how local conditions and global macroeconomic factors ...
    • Wideband Self-Interference Cancellation Using Multi-Tap Filter in Radar Front End 

      Heiskel, Bendik (Mastergradsoppgave; Master thesis, 2020-12-14)
      The largest hurdle in full duplex wireless systems is the self-interference introduced by the transmitted signal into the received signal. In multi antenna systems this interference is caused by the direct coupling between the transmitting and receiving antennas. In systems where the transmitter and receiver uses the same antenna the interference is caused by inadequate isolation between the ...
    • Wind at Northern Senja: Use of numerical weather prediction models for wind resource assessment 

      Hansen, Gjøran Emil (Master thesis; Mastergradsoppgave, 2020-12-15)
      Wind resource assessment for establishing decentralized power production in remote and complex areas, is challenging due to a lack of observational data. To overcome this problem, Numerical Weather Prediction (NWP) models can be used to provide data where no observations exist. This thesis uses NWP models to do a wind resource assessment at northern Senja. The power grid in the area is prone to ...
    • Wind energy and economic assessment of a wind farm at Senja 

      Ørjavik, Ola Wang (Master thesis; Mastergradsoppgave, 2022-05-31)
      In order to deliver on the emission cuts in the Paris Agreement, additional renewable energy production is required to cover the rising energy demand. This thesis assesses the wind resources, energy production potential and the economic sustainability of a new potential wind farm, located at Senja island in northern Norway. The aim of this thesis is to decide if a new wind farm at Senja is an ...
    • Wind power forecasting as input to day-ahead trading strategies for wind in complex terrain 

      Svane, Julie Therese (Master thesis; Mastergradsoppgave, 2022-06-01)
      Giving the increasing penetration of intermittent wind power in the liberalized electricity market, wind power forecasting (WPF) is a topic of growing importance [Kariniotakis, 2017]. The number of papers on the field WPF evaluating the statistical performance has increased rapidly, while only a proportion of the former studies focus on the economic benefit of WPF. In this study we have answered how ...
    • Wind Power Prediction with Machine Learning Methods in Complex Terrain Areas 

      Sæther, Brynhild Bentsen (Master thesis; Mastergradsoppgave, 2021-06-29)
      The increasing amount of intermittant wind energy sources connected to the power grid present several challenges in balancing the power network. Accurate prediction of wind power production is identified as one of the most important measures for balancing the power network while maintaining a sustainable integration of wind power in the power grid. However, the volatile nature of wind makes wind ...
    • Wind power predictions in complex terrain using analog ensembles 

      Birkelund, Yngve; Alessandrini, Stefano; Byrkjedal, Øyvind; Monache, Luca Delle (Journal article; Tidsskriftartikkel, 2018)
    • Wind redistribution of snow impacts the Ka- and Ku-band radar signatures of Arctic sea ice 

      Nandan, Vishnu; Willatt, Rosemary; Mallett, Robbie; Stroeve, Julienne; Geldsetzer, Torsten; Scharien, Randall; Tonboe, Rasmus; Yackel, John; Landy, Jack Christopher; Clemens-Sewall, David; Jutila, Arttu; Wagner, David N.; Krampe, Daniela; Huntemann, Marcus; Mahmud, Mallik; Jensen, David; Newman, Thomas; Hendricks, Stefan; Spreen, Gunnar; Macfarlane, Amy; Schneebeli, Martin; Mead, James; Ricker, Robert; Gallagher, Michael; Duguay, Claude; Raphael, Ian; Polashenski, Chris; Tsamados, Michel; Matero, Ilkka; Hoppmann, Mario (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-02)
      Wind-driven redistribution of snow on sea ice alters its topography and microstructure, yet the impact of these processes on radar signatures is poorly understood. Here, we examine the effects of snow redistribution over Arctic sea ice on radar waveforms and backscatter signatures obtained from a surface-based, fully polarimetric Ka- and Ku-band radar at incidence angles between 0∘ (nadir) and 50∘. ...
    • Wind resource assessment and siting for the expansion of Fakken wind park 

      Bjugg, Martine (Master thesis; Mastergradsoppgave, 2023-05-31)
      Norway is anticipated to experience an energy deficit in the coming years, and one solution to address this issue is the implementation of new renewable energy sources. To mitigate the projected energy deficit, increased energy production is required. With its considerable wind potential, the country offers ample opportunities for wind energy development. Consequently, there is a growing demand for ...
    • Wind resource assessment using mesoscale modelling. A case study at the potential wind farm site Rieppi 

      Blæsterdalen, Torgeir (Master thesis; Mastergradsoppgave, 2016-06-01)
      The growing wind power industry, increased occurrence of extreme weather, and the need for becoming independent of fossil fuels motivate the research on accurate simulation of near-surface wind. The aim of this study is wind resource assessment at the potential wind park site Rieppi, using two on-site measurement masts, simulations from the Weather Research and Forecasting (WRF) model, and ERA-Interim ...
    • Wind resource assessment using weather research and forecasting model. A case study of the wind resources at Havøygavlen wind farm 

      Fossem, Anders Aarhuus (Master thesis; Mastergradsoppgave, 2019-12-13)
      The need for energy increases globally due to rapid expansion of population and prosperity. To meet this demand while decreasing carbon emission and eventually transition out fossil fuel, efficient utilization of wind power is prominent. This study evaluates the performance of the Weather Research and Forecast model (WRF) with respect to wind speed and wind direction. The area of the study is ...
    • Wind speed and direction predictions by WRF and WindSim coupling over Nygårdsfjell 

      Bilal, Muhammad; Birkelund, Yngve; Solbakken, Kine (Journal article; Tidsskriftartikkel; Peer reviewed, 2016)
      In this study, the performance of the mesoscale meteorological Weather Research and Forecast (WRF) model coupled with the microscale computational fluid dynamics based model WindSim is investigated and compared to the performance of WRF alone. The two model set-ups, WRF and WRF-WindSim, have been tested on three high-wind events in February, June and October, over a complex terrain at the ...
    • Winter storms accelerate the demise of sea ice in the Atlantic sector of the Arctic Ocean 

      Graham, Robert M.; Itkin, Polona; Meyer, Amelie; Sundfjord, Arild; Spreen, Gunnar; Smedsrud, Lars H.; Liston, Glen E.; Cheng, Bin; Cohen, Lana; Divine, Dmitry; Fer, Ilker; Fransson, Agneta; Gerland, Sebastian; Haapala, Jari; Hudson, Stephen R.; Johansson, Malin; King, Jennifer A.; Merkouriadi, Ioanna; Peterson, Algot Kristoffer; Provost, Christine; Randelhoff, Achim; Rinke, Annette; Rösel, Anja; Sennechael, Nathalie; Walden, Von P.; Duarte, Pedro; Assmy, Philipp; Steen, Harald; Granskog, Mats A. (Journal article; Peer reviewed, 2019-06-25)
      A large retreat of sea-ice in the ‘stormy’ Atlantic Sector of the Arctic Ocean has become evident through a series of record minima for the winter maximum sea-ice extent since 2015. Results from the Norwegian young sea ICE (N-ICE2015) expedition, a five-month-long (Jan-Jun) drifting ice station in first and second year pack-ice north of Svalbard, showcase how sea-ice in this region is frequently ...
    • Winter warmings, tides and planetary waves. Comparisions between CMAM (with interactive chemistry) and MFR-MetO observations and data. 

      Manson, A.H.; Hall, Chris; Meek, C.; Chshyolkova, T.; McLandress, C.; Avery, S.K.; Fritts, D.C.; Hocking, W.K.; Igarashi, K.; MacDougall, J.W.; Murayama, Y.; Riggin, D.C.; Thorsen, D.; Vincent, R.A. (Journal article; Peer reviewed; Tidsskriftartikkel, 2006-10-20)
      Following earlier comparisons using the Canadian Middle Atmosphere Model (CMAM, without interactive chemistry), the dynamical characteristics of the model are assessed with interactive chemistry activated. Time-sequences of temperatures and winds at Tromsø (70° N) show that the model has more frequent and earlier stratospheric winter warmings than typically observed. Wavelets at mesospheric heights ...
    • The WSO, a world-class observatory for the ultraviolet 

      Solheim, Jan Erik; Barstow, M.A.; Binette, L.; Brosch, N.; Cheng, F-Z.; Dennefeld, M.; Gomez de Castro, A.I.; Haubold, H.; van der Hucht, K.A.; Kappelmann, N.; Martinez, P.; Ribak, E.N.; Moisheev, A.; Pagano, I.; Sahade, J.; Wamsteker, W.; Werner, K.; Becker-Ross, H.; Florek, S.; Shustov, B. (Conference object; Konferansebidrag, 2002-09-17)
      The World Space Observatory is an unconventional space project proceeding via distributed studies. The present design, verified for feasibilty, consists of a 1.7-meter telescope operating at the second Largangian point of the Earth-Sun system. The focal plane instruments consist of three UV spectrometers covering the spectral band from Lyman alpha to the atmospheric cutoff with R~55,000 and offering ...