Now showing items 924-939 of 939

    • 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 ...
    • 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 ...
    • 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 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 ...
    • WSO/UV: World Space Observatory/Ultraviolet 

      Solheim, Jan Erik; Hernanza, M.; González-Riestra, R.; Wamsteker, W.; Shustov, B.; Barstow, M.; Brosch, N.; Fu-Zhen, C.; Dennefeld, M.; Dopita, M.; Gómez de Castro, A.I.; Kappelmannc, N.l.; Pagano, I.; Sahade, J.; Haubold, H.; Solheim, J.-E.; Martínezc, P. (Journal article; Tidsskriftartikkel, 2002-11-05)
      We summarize the capabilities of the World Space Observatory (UV) Project (WSO/UV). An example of the importance of this project (with a planned launch date of 2007/8) for the study of Novae is given.
    • X-, C-, and L-band SAR signatures of newly formed sea ice in Arctic leads during winter and spring 

      Johansson, Malin; Brekke, Camilla; Spreen, Gunnar; King, Jennifer A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-02)
      We examine an extensive synthetic aperture radar (SAR) data set from the Arctic Ocean spanning a time period from January to June 2015, with the aim of identifying multi-polarization parameters that can be used to accurately separate newly formed sea ice from the surroundings. Newly formed sea ice areas both provide favourable routing for ship traffic, and are key to Arctic climate science because ...
    • Year-around C- and L-band observation around the MOSAiC ice floe with high spatial and temporal resolution 

      Singha, Suman; Johansson, Malin; Spreen, Gunnar; Howell, Stephen; Shin-ichi, Sobue; Davidson, Malcolm (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-12)
      In September 2019, the German research icebreaker Polarstern started the largest multidisciplinary Arctic expedition, the MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) drift experiment. Being moored to ice floes at high Arctic for a whole year, thus including the winter season, the main goal of the expedition is to better understand and quantify relevant processes ...
    • A year-round satellite sea-ice thickness record from CryoSat-2 

      Landy, Jack Christopher; Dawson, Geoffrey; Tsamados, Michel; Bushuk, Mitchell; Stroeve, Julienne C.; Howell, Stephen; Krumpen, Thomas; Babb, David G.; Komarov, Alexander S.; Heorton, Harold; Belter, H. Jakob; Aksenov, Yevgeny (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-14)
      Arctic sea ice is diminishing with climate warming at a rate unmatched for at least 1,000 years. As the receding ice pack raises commercial interest in the Arctic, it has become more variable and mobile, which increases safety risks to maritime users. Satellite observations of sea-ice thickness are currently unavailable during the crucial melt period from May to September, when they would be most ...
    • α-Synuclein fibril and synaptic vesicle interactions lead to vesicle destruction and increased lipid-associated fibril uptake into iPSC-derived neurons 

      Stephens, Amberley D.; Villegas, Ana Fernandez; Chung, Chyi Wei; Vanderpoorten, Oliver; Pinotsi, Dorothea; Mela, Ioanna; Ward, Edward; McCoy, Thomas M.; Cubitt, Robert; Routh, Alexander F.; Kaminski, Clemens F.; Kaminski Schierle, Gabriele S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-15)
      Monomeric alpha-synuclein (aSyn) is a well characterised protein that importantly binds to lipids. aSyn monomers assemble into amyloid fibrils which are localised to lipids and organelles in insoluble structures found in Parkinson’s disease patient’s brains. Previous work to address pathological aSyn-lipid interactions has focused on using synthetic lipid membranes, which lack the complexity of ...