Viser treff 194-213 av 942

    • Direct and indirect impacts of climate change on wheat yield in the Indo-Gangetic plain in India 

      Daloz, Anne Sophie; Rydsaa, Johanne Hope; Sillmann, Jana; Hodnebrog, Øivind; Oort, Bob Eric Helmuth van; Emberson, Lisa; Zhang, Tianyi; Agrawal, Madhoolika (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-28)
      The Indo-Gangetic Plain (IGP) is one of the main wheat-production regions in India and the world. With climate change, wheat yields in this region will be affected through changes in temperature and precipitation and decreased water availability for irrigation, raising major concerns for national and international food security. Here we use a regional climate model and a crop model to better understand ...
    • Direct growth of single-layer terminated vertical graphene array on germanium by plasma enhanced chemical vapor deposition 

      Al-Hagri, Abdulrahman; Li, Ru; Rajput, Nitul S; Lu, Jin-You; Cong, Shan; Sloyan, Karen; Almahri, Mariam Ali; Tamalampudi, Srinivasa Reddy; Chiesa, Matteo; Al Ghaferi, Amal (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-26)
      Vertically aligned graphene nanosheet arrays (VAGNAs) exhibit large surface area, excellent electron transport properties, outstanding mechanical strength, high chemical stability, and enhanced electrochemical activity, which makes them highly promising for application in supercapacitors, batteries, fuel cell catalysts, etc. It is shown that VAGNAs terminated with a high-quality single-layer graphene ...
    • Direct Measurement of the Magnitude of the van der Waals Interaction of Single and Multilayer Graphene 

      Chiou, Yu-Cheng; Olukan, Tuza Adeyemi; Almahri, Mariam Ali; Apostoleris, Harry; Chiu, Cheng Hsiang; Lai, Chia-Yun; Lu, Jin-You; Santos, Sergio; Almansouri, Ibraheem; Chiesa, Matteo (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-23)
      Vertical stacking of monolayers via van der Waals (vdW) assembly is an emerging field that opens promising routes toward engineering physical properties of two-dimensional materials. Industrial exploitation of these engineering heterostructures as robust functional materials still requires bounding their measured properties so as to enhance theoretical tractability and assist in experimental designs. ...
    • Directional features of the downshifted peak observed in HF-induced stimulated electromagnetic emission spectra obtained using an interferometer. 

      Rietveld, Michael T.; Tereshchenko, E.D.; Belyey, Vasyl; Yurik, R.Yu; Brekke, Asgeir; Khudukon, B.Z.; Isham, B.; Hagfors, T.; Grill, M. (Journal article; Peer reviewed; Tidsskriftartikkel, 2006-08-09)
      A high frequency (HF) ionospheric modification experiment was carried out between 25 September and 8 October 2004, using the EISCAT HF transmitter located near Tromsø, Norway. During this experiment the spectra of the stimulated HF sideband waves (stimulated electromagnetic emission or SEE) induced by the HF pump were observed using an interferometer consisting of three spaced receiving antennas ...
    • Discerning the Contribution of Morphology and Chemistry in Wettability Studies 

      Sloyan, Karen; Lai, Chia-Yun; Lu, Jin-You; Alfakes, Boulos; Al Hassan, Saeed; Almansouri, Ibraheem; Dahlem, Marcus S; Chiesa, Matteo (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-07-15)
      The wetting behavior of homogeneous systems is now well understood at the macroscopic scale. However, this understanding offers little predictive power regarding wettability when mesoscopic chemical and morphological heterogeneities come into play. The fundamental interest in the effect of heterogeneity on wettability is derived from its high technological relevance in several industries, including ...
    • Discriminative multimodal learning via conditional priors in generative models 

      Andrade Mancisidor, Rogelio; Kampffmeyer, Michael Christian; Aas, Kjersti; Jenssen, Robert (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-02)
      Deep generative models with latent variables have been used lately to learn joint representations and generative processes from multi-modal data, which depict an object from different viewpoints. These two learning mechanisms can, however, conflict with each other and representations can fail to embed information on the data modalities. This research studies the realistic scenario in which all ...
    • The Discus Comet: C/2014 B1 (Schwartz) 

      Jewitt, David; Kim, Yoonyoung; Luu, Jane; Graykowski, Ariel (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-08)
      Long-period comet C/2014 B1 (Schwartz) exhibits a remarkable optical appearance, like that of a discus or bi-convex lens viewed edgewise. Our measurements in the four years since discovery reveal a unique elongated dust coma whose orientation is stable with respect to the projected antisolar and orbital directions. With no tail and no trail, the limited influence of radiation pressure on the dust ...
    • Distinguishing Mineral Oil Slicks from Low Wind Areas using Rapid Repeat Synthetic Aperture Radar Imagery 

      Quigley, Cornelius Patrick; Johansson, Anna Malin Kristin; Jones, Cathleen Elaine; Holt, Benjamin (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-18)
      A method for differentiating marine oil slicks from radar-dark, low wind areas in open water using rapid repeat SAR imagery is reported. The study uses data acquired by the airborne UAVSAR L-band SAR instrument, imaging the Coal Oil Point seep field near Santa Barbara, California. Time-series of images from three different days are analyzed, all containing both verified oil slicks and low wind zones. ...
    • The Distribution of Small-Scale Irregularities in the E-Region, and Its Tendency to Match the Spectrum of Field-Aligned Current Structures in the F-Region 

      Ivarsen, Magnus Fagernes; Lozinsky, Adam; St-Maurice, Jean-Pierre; Spicher, Andres; Huyghebaert, Devin Ray; Hussey, Glenn C.; Galeschuk, Draven; Pitzel, Brian; Vierinen, Juha (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-16)
      We associate new data from icebear, a coherent scatter radar located in Saskatchewan, Canada, with scale-dependent physics in the ionosphere. We subject the large-scale icebear 3D echo patterns (treated as 2D point clouds) to a data analysis technique hitherto never applied to the ionosphere, a technique that is widely applied in cosmological red-shift surveys to characterize the spatial clustering ...
    • Does your lab use social media? Sharing three years of experience in science communication 

      Pavlov, Alexey K.; Meyer, Amelie; Rösel, Anja; Cohen, Lana; King, Jennifer; Itkin, Polona; Negrel, Jean; Gerland, Sebastian; Hudson, Stephen R.; Dodd, Paul A.; de Steur, Laura; Mathisen, Stig; Cobbing, Nick; Granskog, Mats A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-27)
      Effective science communication is essential to share knowledge and recruit the next generation of researchers. Science communication to the general public can, however, be hampered by limited resources and a lack of incentives in the academic environment. Various social media platforms have recently emerged, providing free and simple science communication tools to reach the public and young people ...
    • Drone-Mounted UWB Snow Radar: Technical Improvements and Field Results 

      Jenssen, Rolf-Ole Rydeng; Jacobsen, Svein Ketil (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-04)
      Drone borne radar systems have seen considerable advances over recent years, and the application of drone-mounted continuous wave (CW) radars for remote sensing of snow properties has great potential. Regardless, major challenges remain in antenna design for which both low weight and small size combined with high gain and bandwidth are important design parameters. Additional limiting factors for CW ...
    • Droner som FKT - bruk av droner som forebyggende tiltak i beitenæringen 

      Winje, Erlend; Bjørn, Tor-Arne; Hansen, Inger; Meisingset, Erling; Haugen, Atilla; Heppelmann, Joachim Bernd; Myhre, Jonas Nordhaug; Wagner, Gabriela (Research report; Forskningsrapport, 2023)
      Utmarksbeitende dyr er utsatt for angrep fra fredet rovvilt. I oppdrag fra rovviltnemnda i region 6 Midt-Norge undersøker vi den mulige nytteverdien av droner i åpen kategori som forebyggende- og konfliktdempende tiltak (FKT). Utredningen er basert på informasjon fra intervjuer, faglitteratur og dronetestflygninger.Droner som FKT kan brukes under (1) tilsyn, (2) flytting av dyr fra rovdyrutsatte ...
    • Dust charging and density conditions deduced from observations of PMWE modulated by artificial electron heating 

      Havnes, Ove; La Hoz, Cesar; Rietveld, Michael T; Kassa, Meseret; Baroni, Giovanni; Biebricher, Alexander (Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
      We present an analysis of relatively strong Polar Mesospheric Winter Echoes (PMWE) under artificial electron heating that changes the PMWE intensity. A major purpose is to find reliable estimates of the relaxation time of the heater modified PMWE to their undisturbed state during the heater switch-off phase; the implications regarding charge/discharge mechanisms; and to exploit the diagnostic potential ...
    • Dust observations from Parker Solar Probe: Dust ejection from the inner Solar System 

      Mann, Ingrid; Czechowski, Andrzej (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-02)
      Context. The FIELDS instrument onboard Parker Solar Probe (PSP) observes dust impacts on the spacecraft. The derived dust flux rates suggest that the particles originate from the vicinities of the Sun and are ejected by radiation pressure. Radiation pressure typically ejects particles of several 100 nm and smaller, which are also affected by the electromagnetic force.<p> Aims. We aim to understand ...
    • Dust observations with antenna measurements and its prospects for observations with Parker Solar Probe and Solar Orbiter 

      Mann, Ingrid; Nouzak, Libor; Vaverka, Jakub; Antonsen, Tarjei; Fredriksen, Åshild; Issautier, Karine; Malaspina, David; Meyer-Vernet, Nicole; Pavlu, Jiri; Sternovsky, Zoltan; Stude, Joan; Ye, Shengyi; Zaslavsky, Arnaud (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-10)
      The electric and magnetic field instrument suite FIELDS on board the NASA Parker Solar Probe and the radio and plasma waves instrument RPW on the ESA Solar Orbiter mission that explore the inner heliosphere are sensitive to signals generated by dust impacts. Dust impacts have been observed using electric field antennas on spacecraft since the 1980s and the method was recently used with a number of ...
    • Dust sputtering within the inner heliosphere: a modelling study 

      Baumann, Carsten; Myrvang, Margaretha; Mann, Ingrid (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-03)
      The aim of this study is to investigate how sputtering by impacting solar wind particles influence the lifetime of dust particles in the inner heliosphere near the Sun.<p><p> We consider three typical dust materials: silicate, Fe<sub>0.4</sub>Mg<sub>0.6</sub>O and carbon and describe their sputtering yields based on atomic yields given by the Stopping and Range of Ions in Matter (SRIM) package. ...
    • Dust Trajectory Calculations in the Inner Heliosphere and Circumstellar Debris Disks 

      Mann, Ingrid; Stamm, Johann Immanuel; Czechowski, Andrzej; Baumann, Carsten; Myrvang, Margaretha; Li, Aigen (Conference object; Konferansebidrag, 2018)
    • Dust trajectory simulations around Sun, Vega, and Fomalhaut 

      Stamm, Johann Immanuel; Czechowski, Andrzej; Mann, Ingrid; Baumann, Carsten; Myrvang, Margaretha (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-20)
      <p><i>Context - </i>Vega and Fomalhaut display a thermal emission brightness that can possibly arise from hot dust near the stars, an inner extension of their planetary debris disks. There was brought up an idea that nm-sized dust particles are kept in the vicinity of the stars by electromagnetic forces. This resembles the trapping that model calculations show in the corotating magnetic field in the ...
    • Dynamic rayed aurora and enhanced ion-acoustic radar echoes 

      Blixt, Erik Mårten; Ivchenko, N.; Hagfors, T.; Grydeland, Tom; Trondsen, T.S.; La Hoz, Cesar; Lanchester, B.S.; Løvhaug, Unni Pia (Journal article; Tidsskriftartikkel; Peer reviewed, 2005-01-31)
      The generation mechanism for naturally enhanced ion-acoustic echoes is still debated. One important issue is how these enhancements are related to auroral activity. All events of enhanced ion-acoustic echoes observed simultaneously with the EISCAT Svalbard Radar (ESR) and with high-resolution narrow field-of-view auroral imagers have been collected and studied. Characteristic of all the ...
    • Dynamics of Dust Particles near Sun, Vega and Fomalhaut 

      Stamm, Johann Immanuel; Baumann, Carsten; Czechowski, Andrzej; Mann, Ingrid; Myrvang, Margaretha (Conference object; Konferansebidrag, 2018)