Viser treff 441-460 av 1428

    • A 30-year probability map for oil spill trajectories in the barents sea to assess potential environmental and socio-economic threats 

      Pavlov, Victor; Martins de Aguiar, Victor Cesar; Hole, Lars Robert; Pongrácz, Eva (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-24)
      Increasing exploration and exploitation activity in the Arctic Ocean has intensified maritime traffic in the Barents Sea. Due to the sparse population and insufficient oil spill response infrastructure on the extensive Barents Sea shoreline, it is necessary to address the possibility of offshore accidents and study hazards to the local environment and its resources. Simulations of surface oil ...
    • Unbalanced low coherence interference microscopy 

      Ahmad, Azeem; Habib, Anowarul; Dubey, Vishesh Kumar; Ahluwalia, Balpreet Singh (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-03)
      Low coherence interference microscopy (LCIM) provides high spatial phase sensitivity, i.e., speckle free and coherent noise free quantitative phase images of the test specimens. Due to low temporal coherence (TC) length of the light source, LCIM requires precise adjustment of the optical path difference (OPD) between the object and the reference arm, which is only a few micrometers. Consequently, ...
    • Overview: Recent advances in the understanding of the northern Eurasian environments and of the urban air quality in China-a Pan-Eurasian Experiment (PEEX) programme perspective 

      Lappalainen, Hanna K.; Petäjä, Tuukka; Vihma, Timo Pekka; Räisänen, Jouni; Baklanov, Alexander; Chalov, Sergey; Esau, Igor; Ezhova, Ekaterina; Leppäranta, Matti; Pozdnyakov, Dmitry; Pumpanen, Jukka; Andreae, Meinrat O.; Arshinov, Mikhail; Asmi, Eija; Bai, Jianhui; Bashmachnikov, Igor; Belan, Boris; Bianchi, Federico; Biskaborn, Boris; Boy, Michael; Bäck, Jaana; Cheng, Bin; Chubarova, Natalia; Duplissy, Jonathan; Dyukarev, Egor; Eleftheriadis, Konstantinos; Forsius, Martin; Heimann, Martin; Juhola, Sirkku; Konovalov, Vladimir; Konovalov, Igor; Konstantinov, Pavel; Köster, Kajar; Lapshina, Elena; Lintunen, Anna; Mahura, Alexander; Makkonen, Risto; Malkhazova, Svetlana; Mammarella, Ivan; Mammola, Stefano; Mazon, Stephany Buenrostro; Meinander, Outi; Mikhailov, Eugene; Miles, Victoria; Myslenkov, Stanislav; Orlov, Dmitry; Paris, Jean-Daniel; Pirazzini, Roberta; Popovicheva, Olga; Pulliainen, Jouni; Rautiainen, Kimmo; Sachs, Torsten; Shevchenko, Vladimir; Skorokhod, Andrey; Stohl, Andreas; Suhonen, Elli; Thomson, Erik S.; Tsidilina, Marina; Tynkkynen, Veli-Pekka; Uotila, Petteri; Virkkula, Aki; Voropay, Nadezhda; Wolf, Tobias; Yasunaka, Sayaka; Zhang, Jiahua; Qiu, Yubao; Ding, Aijun; Guo, Huadong; Bondur, Valery; Kasimov, Nikolay; Zilitinkevich, Sergej; Kerminen, Veli-Matti; Kulmala, Markku (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-06)
      The Pan-Eurasian Experiment (PEEX) Science Plan, released in 2015, addressed a need for a holistic system understanding and outlined the most urgent research needs for the rapidly changing Arctic-boreal region. Air quality in China, together with the long-range transport of atmospheric pollutants, was also indicated as one of the most crucial topics of the research agenda. These two geographical ...
    • Rechargeable Iron-Ion Battery Using a Pure Ionic Liquid Electrolyte 

      Zhao, Yansong; Zhen, Yingpeng; Boström, Tobias Kristoffer (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-07-07)
      A rechargeable iron-ion battery (Fe-ion battery) has been fabricated in our laboratory using a pure ionic liquid electrolyte. Magnetic ionic liquids of 1-butyl-3-methylimidazolium tetrachloroferrate (BmimFeCl<sub>4</sub>) and 1-methyl-3-octylimidazolium tetrachloroferrate (OmimFeCl<sub>4</sub>) are synthesized and utilized as electrolytes in this work. The chemical structure of the two ionic ...
    • Three-dimensional structured illumination microscopy data of mitochondria and lysosomes in cardiomyoblasts under normal and galactose-adapted conditions 

      Opstad, Ida Sundvor; Godtliebsen, Gustav; Ströhl, Florian; Myrmel, Truls; Ahluwalia, Balpreet Singh; Agarwal, Krishna; Birgisdottir, Åsa birna (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-23)
      This three-dimensional structured illumination microscopy (3DSIM) dataset was generated to highlight the suitability of 3DSIM to investigate mitochondria-derived vesicles (MDVs) in H9c2 cardiomyoblasts in living or fxed cells. MDVs act as a mitochondria quality control mechanism. The cells were stably expressing the tandem-tag eGFP-mCherry-OMP25-TM (outer mitochondrial membrane) which can be used ...
    • Mixing up contrastive learning: Self-supervised representation learning for time series 

      Wickstrøm, Kristoffer; Kampffmeyer, Michael; Mikalsen, Karl Øyvind; Jenssen, Robert (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-14)
      The lack of labeled data is a key challenge for learning useful representation from time series data. However, an unsupervised representation framework that is capable of producing high quality representations could be of great value. It is key to enabling transfer learning, which is especially beneficial for medical applications, where there is an abundance of data but labeling is costly and time ...
    • Machine Learning Detection of Dust Impact Signals Observed by The Solar Orbiter 

      Kvammen, Andreas; Wickstrøm, Kristoffer; Kociscak, Samuel; Vaverka, Jakub; Nouzak, Libor; Zaslavsky, Arnaud; Rackovic Babic, Kristina; Gjelsvik, Amalie; Pisa, David; Souček, Jan; Mann, Ingrid (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-11)
      This article present results from automatic detection of dust impact signals observed by the Solar Orbiter – Radio and Plasma Waves instrument.<p> <p>A sharp and characteristic electric field signal is observed by the Radio and Plasma Waves instrument when a dust particle impact the spacecraft at high velocity. In this way, ∼5–20 dust impacts are daily detected as the Solar Orbiter travels through ...
    • Deep microlocal reconstruction for limited-angle tomography 

      Andrade-Loarca, Héctor; Kutyniok, Gitta Astrid Hildegard; Öktem, Ozan; Petersen, Philipp (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-04)
      We present a deep-learning-based algorithm to jointly solve a reconstruction problem and a wavefront set extraction problem in tomographic imaging. The algorithm is based on a recently developed digital wavefront set extractor as well as the well-known microlocal canonical relation for the Radon transform. We use the wavefront set information about x-ray data to improve the reconstruction ...
    • Formation of ice particles through nucleation in the mesosphere 

      Tanaka, Kyoko; Mann, Ingrid; Kimura, Yuki (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-28)
      Observations of polar mesospheric clouds have revealed the presence of solid ice particles in the upper mesosphere at high latitudes; however, their formation mechanism remains uncertain. In this study, we investigated the formation process of ice particles through nucleation from small amounts of water vapor at low temperatures. Previous studies that used classical nucleation theory have shown ...
    • Report From Surveys To Assess Harp And Hooded Seal Pup Production In The Greenland Sea Pack-Ice In 2022 

      Biuw, Martin; Nilssen, Kjell Tormod; Kristiansen, Martin; Lindblom, Lotta; Poltermann, Michael Tino; Haug, Tore; Johansson, Malin (Research report; Forskningsrapport, 2022-06-07)
      Cruise no.: 2022703 : The 2022 survey of harp and hooded seal pup production in the Greenland Sea was carried out to obtain updated estimates to be used to assess current status of these two seal stocks. Since a similar survey in 2018 indicated a 40% reduction in harp seal pup production since the 2012 survey, and the continued lack of increase in pup production of the severely depleted hooded ...
    • Thermodynamic and dynamic contributions to seasonal Arctic sea ice thickness distributions from airborne observations 

      von Albeldyll, Luisa; Hendricks, Stefan; Grodofzig, Raphael; Krumpen, Thomas; Arndt, Stefanie; Belter, H. Jakob; Birnbaum, Gerit; Cheng, Bin; Hoppmann, Mario; Hutchings, Jennifer; Itkin, Polona; Lei, Ruibo; Nicolaus, Marcel; Ricker, Robert; Rohde, Jan; Suhrhoff, Mira; Timofeeva, Anna; Watkins, Daniel; Webster, Melinda; Haas, Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-18)
      Sea ice thickness is a key parameter in the polar climate and ecosystem. Thermodynamic and dynamic processes alter the sea ice thickness.The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition provided a unique opportunity to study seasonal sea ice thickness changes of the same sea ice. We analyzed 11 large-scale (*50 km) airborne electromagnetic sea thickness ...
    • Validation of Multistatic Meteor Radar Analysis Using Modeled Mesospheric Dynamics: An Assessment of the Reliability of Gradients and Vertical Velocities 

      Charuvil Asokan, Harikrishnan; Chau, Jorge L.; Larsen, Miguel F.; Conte, J. Federico; Marino, Raffaele; Vierinen, Juha; Baumgarten, Gerd; Borchert, Sebastian (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-28)
      A virtual meteor radar system based on the upper-atmosphere extension of the high-resolution ICOsahedral Non-hydrostatic general circulation model is constructed to validate multistatic specular meteor radar (SMR) analyses. The virtual radar system examines the validity of mean winds and gradients estimation techniques used in multistatic SMRs. The study is motivated by unexpected mean values and ...
    • 2022 Tonga Volcanic Eruption Induced Global Propagation of Ionospheric Disturbances via Lamb Waves 

      Zhang, Shun-Rong; Vierinen, Juha; Aa, Ercha; Goncharenko, Larisa P.; Erickson, Philip J.; Rideout, William; Coster, Anthea J.; Spicher, Andres (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-23)
      The Tonga volcano eruption at 04:14:45 UT on 2022-01-15 released enormous amounts of energy into the atmosphere, triggering very significant geophysical variations not only in the immediate proximity of the epicenter but also globally across the whole atmosphere. This study provides a global picture of ionospheric disturbances over an extended period for at least 4 days. We find traveling ionospheric ...
    • ICEBEAR-3D: A Low Elevation Imaging Radar Using a Non-Uniform Coplanar Receiver Array for E Region Observations 

      Lozinsky, Adam; Hussey, Glenn; McWilliams, Kathryn; Huyghebaert, Devin Ray; Galeschuk, Draven (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-19)
      The Ionospheric Continuous-wave E region Bistatic Experimental Auroral Radar (ICEBEAR) has been reconfigured using a phase error minimization and stochastic antenna location perturbation technique. The resulting 45-baseline sparse non-uniform coplanar T-shaped array, ICEBEAR-3D, is used for aperture synthesis radar imaging of low elevation targets. The reconfigured receiver antenna array now has ...
    • Inference Guided Few-Shot Segmentation 

      Burman, Joel (Master thesis; Mastergradsoppgave, 2022-06-22)
      Few-shot segmentation has in recent years gotten a lot of attention. The reason is its ability to segment images from classes based on only a handful of labeled support images. This opens up many possibilities when the need for a big dataset is removed. To do this a few-shot segmentation network need to extract as much quality information from each support image as possible. In this thesis we ...
    • Rossby Wave Changes During the Recent Decades in Mid-Latitude Continents in the Northern Hemisphere 

      Juskenaite, Ieva (Master thesis; Mastergradsoppgave, 2022-06-22)
      Increasing frequency and severity of extreme weather events throughout the recent years is a highly concerning topic. Extreme and unusual weather conditions, such as heat waves, floods and cold spells are causing a major concern for humanity. Agricultural changes, damages in infrastructure and the loss of human lives are some of the extreme weather event consequences, with the most drastic consequences ...
    • Finite element simulation of transmission and reflection of acoustic waves in the ultrasonic transducer 

      Shukla, Kaushik; Ahmad, Azeem; Ahluwalia, Balpreet Singh; Melandsø, Frank; Habib, Anowarul (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-30)
      In scanning acoustic microscopy (SAM), the image quality depends on several factors such as noise level, resolution, and interaction of the waves with sample boundaries. The theoretical equations for the reflection coefficient and transmission coefficient are suitable for plane boundaries but fail for curved/rough boundaries. We presented a finite element method-based modeling for the loss ...
    • Plasma-neutral gas interactions in various space environments: Assessment beyond simplified approximations as a Voyage 2050 theme 

      Yamauchi, Masatoshi; De Keyser, Johan; Parks, George; Oyama, Shin-ichiro; Wurz, Peter; Abe, Takumi; Beth, Arnaud; Daglis, Ioannis A.; Dandouras, Iannis; Dunlop, Malcolm; Henri, Pierre; Ivchenko, Nickolay; Kallio, Esa; Kucharek, Harald; Liu, Yong C.-M.; Mann, Ingrid; Marghitu, Octav; Nicolaou, Georgios; Rong, Zhaojin; Sakanoi, Takeshi; Saur, Joachim; Shimoyama, Manabu; Taguchi, Satoshi; Tian, Feng; Tsuda, Takuo; Tsurutani, Bruce; Turner, Drew; Ulich, Thomas; Yau, Andrew; Yoshikawa, Ichiro (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-26)
      In the White Paper, submitted in response to the European Space Agency (ESA) Voyage 2050 Call, we present the importance of advancing our knowledge of plasma-neutral gas interactions, and of deepening our understanding of the partially ionized environments that are ubiquitous in the upper atmospheres of planets and moons, and elsewhere in space. In future space missions, the above task ...
    • Network Analysis and Boosting the Distribution to Local Consumers at Northern Senja, Norway with Potential Renewable Generation using Power Flow Control 

      Rochmann, Karl Henrik (Master thesis; Mastergradsoppgave, 2022-06-08)
      Renewable generation and power flow control are increasing its importance for power systems. The promising development in the technology increases the efficiency for transferring energy. With increasing consumption, remote locations benefit from close laying power production due to reduced transfer losses. In these recent years, energy storage system and local renewable energy production injected ...
    • Solar Photovoltaic Potential on Commercial Buildings in Arctic Latitudes 

      Larsen, Andreas (Master thesis; Mastergradsoppgave, 2022-06-01)
      This thesis desires to study the use of solar resources in a less frequently used location, by exploring the use of a photovoltaic systems on the roof of a warehouse in Tromsø, Norway. The research is gathered using a 15 000 𝑚2 warehouse as the location, which has an annual energy consumption of 2,9 GWh. The solar resources at this location are highly dependent on season, with periods of polar ...