Now showing items 21-40 of 972

    • Exploring the universe through dusty visions 

      Khawaja, Nozair; Klenner, Fabian; Szalay, Jamey; Kobayashi, Masanori; Briois, Christelle; Mann, Ingrid Brigitte (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-05-13)
      Dust in space is a universal phenomenon that can be observed within our cosmic neighbourhood. Examples include the dust from the surface of the moon to the further reaches of the outer solar system, such as Saturn’s rings, and even beyond in the galactic environment. Dust in the universe has constantly challenged astronomers’ views of heavenly bodies and phenomena, often obscuring light coming from ...
    • Conceptualization of a vehicle-to-grid assisted nation-wide renewable energy system – A case study with spain 

      Sagaria, Shemin; van der Kam, Mart; Boström, Tobias Kristoffer (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-02-08)
      This study explores the potential of Vehicle-to-Grid (V2G) technology in utilizing Electric Vehicle (EV) batteries for energy storage, aiming to fulfil Spain’s 2030 and 2050 energy goals. The validated Simulink model uses 3.15 million EVs in 2030 and 22.7 million EVs in 2050 as primary energy storage. The results show that Spain can achieve its 2030 target of 42 % renewable energy by utilizing ...
    • The influence of socio-technical variables on vehicle-to-grid technology 

      Sagaria, Shemin; Kam, Mart van der; Boström, Tobias Kristoffer Good (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-07-04)
      Vehicle-to-grid technology (V2G) is a novel large scale energy storage option to improve the grid integration of renewable energy sources (RES). Using electric vehicle (EV) batteries to store and provide electricity to the grid, the intermittency of RES can be reduced. However, a successful implementation of this technology depends on various social and technological factors. This study analyses the ...
    • Taxonomy of hybridly polarized Stokes vortex beams 

      Arora, Gauri; Butola, Ankit; Rajput, Ruchi; Agarwal, Rohit; Agarwal, Krishna; Horsch, Ludwig Alexander; Prasad, Dilip Kumar; Senthilkumaran, Paramasivam (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-02-15)
      Structured beams carrying topological defects, namely phase and Stokes singularities, have gained extensive interest in numerous areas of optics. The non-separable spin and orbital angular momentum states of hybridly polarized Stokes singular beams provide additional freedom for manipulating optical fields. However, the characterization of hybridly polarized Stokes vortex beams remains challenging ...
    • Abrupt increase in Greenland melt enhanced by atmospheric wave changes 

      Graversen, Rune Grand; Heiskanen, Tuomas Ilkka Henrikki; Bintanja, Richard; Goelzer, Heiko (Journal article; Tidsskriftartikkel, 2024-05-25)
      Recent Greenland ice-sheet melt constitutes a considerable contribution to global sea-level rise. Observations indicate an approximate zero mass balance of the ice sheet until the late 1990s, after which a strong increase in melting occurred. This cannot be attributed linearly to gradually-increasing global warming. Instead the abrupt shift has been linked to atmospheric circulation changes, although ...
    • Leveraging tensor kernels to reduce objective function mismatch in deep clustering 

      Trosten, Daniel Johansen; Løkse, Sigurd Eivindson; Jenssen, Robert; Kampffmeyer, Michael Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-29)
      Objective Function Mismatch (OFM) occurs when the optimization of one objective has a negative impact on the optimization of another objective. In this work we study OFM in deep clustering, and find that the popular autoencoder-based approach to deep clustering can lead to both reduced clustering performance, and a significant amount of OFM between the reconstruction and clustering objectives. To ...
    • Extent, duration and timing of the sea ice cover in Hornsund, Svalbard in 2014–2023 

      Swirad, Zuzanna M.; Johansson, Anna Malin Kristin; Malnes, Eirik (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-02-27)
      The Sentinel-1A/B synthetic aperture radar (SAR) imagery archive between 14 October 2014 and 29 June 2023 was used in combination with a segmentation algorithm to create a series of binary ice/open-water maps of Hornsund fjord, Svalbard, at 50 m resolution for nine seasons (2014/15 to 2022/23). The near-daily (1.57 d mean temporal resolution) maps were used to calculate sea ice coverage for the ...
    • Towards seamless environmental prediction–development of Pan-Eurasian EXperiment (PEEX) modelling platform 

      Mahura, Alexander; Baklanov, Alexander; Makkonen, Risto; Boy, Michael; Petäjä, Tuukka; Lappalainen, Hanna K.; Nuterman, Roman; Kerminen, Veli-Matti; Arnold, Stephen R.; Jochum, Markus; Shvidenko, Anatoly; Esau, Igor; Sofiev, Mikhail; Stohl, Andreas; Aalto, Tuula; Bai, Jianhui; Chen, Chuchu; Cheng, Yafang; Drofa, Oxana; Huang, Mei; Järvi, Leena; Kokkola, Harri; Kouznetsov, Rostislav; Li, Tingting; Malguzzi, Piero; Monks, Sarah; Poulsen, Mads Bruun; Noe, Steffen M.; Palamarchuk, Yuliia; Foreback, Benjamin; Clusius, Petri; Rasmussen, Till Andreas Soya; She, Jun; Sørensen, Jens Havskov; Spracklen, Dominick; Su, Hang; Tonttila, Juha; Wang, Siwen; Wang, Jiandong; Wolf, Tobias; Yu, Yongqiang; Zhang, Qing; Zhang, Wei; Zhang, Wen; Zheng, Xunhua; Li, Siqi; Li, Yong; Zhou, Putian; Kulmala, Markku (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-04-09)
      The Pan-Eurasian Experiment Modelling Platform (PEEX-MP) is one of the key blocks of the PEEX Research Programme. The PEEX MP has more than 30 models and is directed towards seamless environmental prediction. The main focus area is the Arctic-boreal regions and China. The models used in PEEX-MP cover several main components of the Earth’s system, such as the atmosphere, hydrosphere, pedosphere and ...
    • The basics of optical alignment 

      Ströhl, Florian (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-26)
      Precise optical alignment is critical for high-quality microscopy imaging, especially in custom-built systems. This guide details essential alignment steps, from beam path setup to lens collimation and centering, introduces key tools like pinholes and shearing interferometers, and advocates for a modular construction approach. This article aims to empower microscopy enthusiasts with practical alignment ...
    • Impact ionization double peaks analyzed in high temporal resolution on Solar Orbiter 

      Kociscak, Samuel; Kvammen, Andreas; Mann, Ingrid Brigitte; Meyer-Vernet, Nicole; Pisa, David; Souček, Jan; Theodorsen, Audun; Vaverka, Jakub; Zaslavsky, Arnaud (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-05-29)
      Solar Orbiter is equipped with electrical antennas performing fast measurements of the surrounding electric field. The antennas register high-velocity dust impacts through the electrical signatures of impact ionization. Although the basic principle of the detection has been known for decades, the understanding of the underlying process is not complete, due to the unique mechanical and electrical ...
    • Cross-population evaluation of cervical cancer risk prediction algorithms 

      Elvatun, Severin; Knoors, Daan; Nygård, Mari Kiens; Uusküla, Anneli; Võrk, Andres; Nygård, Jan Franz (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-24)
      Background - Cervical cancer is a preventable disease, despite being one of the most common types of female cancers worldwide. Integrating existing programs for cervical cancer screening with personalized risk prediction algorithms can improve population-level cancer prevention by enabling more targeted screening and contrive preventive healthcare innovations. While algorithms developed for cervical ...
    • Analysis of time series of polarimetric sea ice signatures observed in fast ice it the Belgica Bank area 

      Eltoft, Torbjørn; Johansson, Malin; Lohse, Johannes; Ferro-Famil, Laurent (Journal article; Tidsskriftartikkel, 2023-10-20)
      The CIRFA-Cruise 2022 with <i>RV Kronprins Haakon</i> to the north-eastern coast of Greenland in the period April 22nd to May 9th 2022 was organised to perform measurements and make observations which allow for validation of sea ice remote sensing information and forecast products resulting from work in the Centre for Integrated Remote Sensing and Forecasting for Arctic Operations(CIRFA), a Centre ...
    • 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. ...
    • Correlation between Wettability and Dissolution of Calcite in Ion-Free Water 

      AlMahri, Mariam; Lu, Jin-You; Chen, Shih-Wen; Olukan, Tuza Adeyemi; Yang, Thomas Chung-Kuang; Alhassan, Saeed; Chiesa, Matteo (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-13)
      Calcite, a prevalent mineral in the earth’s crust, plays a pivotal role in various geological and industrial processes, including carbon sequestration, water treatment, and enhanced oil recovery. Understanding how wettability (a crucial surface property influenced by the interaction between calcite and surrounding fluids) affects calcite’s dissolution is essential for optimizing these processes. We ...
    • On the strength of E and F region irregularities for GNSS scintillation in the dayside polar ionosphere 

      Madhanakumar, Mahith; Spicher, Andres; Vierinen, Juha-Pekka; Oksavik, Kjellmar (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-03-02)
      We present results of the study conducted to quantify the relative contribution of different ionospheric regions to phase scintillation in Global Navigation Satellite Systems (GNSS) at the dayside high latitude ionosphere. By taking advantage of the scanning capability of the 32-m EISCAT radar in Svalbard (ESR) and its recurrent favourable location below the dayside auroral region, we developed ...
    • Simultaneous electrochemical determination of benzenediol compounds in environmental samples using nano architectures of hydrogen ammonium zinc molybdate layered double hydroxides integrated with carbon black modified electrode 

      Karuppiah, Chelladurai; Babulal, Sivakumar Musuvadhi; Chen, Shen-Ming; Palanisamy, Selvakumar; Hsu, Li-Fan; Yang, Chun-Chen; Chiesa, Matteo (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-02)
      Phenolic compounds, such as benzenediol (BD), are toxic and exhibit poor biodegradability, posing a threat to human health and the environment, even at low concentrations. Therefore, the simultaneous detection of BD at low detection limits and a wide detection range is of significant interest for monitoring water quality and environmental remediation efforts. In this study, we developed a novel ...
    • Quantification of van der Waals forces in bimodal and trimodal AFM 

      Santos Hernandez, Sergio; Gadelrab, Karim; Elsherbiny, Lamiaa; Drexler, Xaver; Olukan, Tuza Adeyemi; Font, Josep; Barcons, Victor; Chiesa, Matteo (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-22)
      The multifrequency formalism is generalized and exploited to quantify attractive forces, i.e., van der Waals interactions, with small amplitudes or gentle forces in bimodal and trimodal atomic force microscopy (AFM). The multifrequency force spectroscopy formalism with higher modes, including trimodal AFM, can outperform bimodal AFM for material property quantification. Bimodal AFM with the second ...
    • Quasi Monte Carlo time-frequency analysis 

      Levie, Ron; Avron, Haim; Kutyniok, Gitta Astrid Hildegard (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-30)
      We study signal processing tasks in which the signal is mapped via some generalized time-frequency transform to a higher dimensional time-frequency space, processed there, and synthesized to an output signal. We show how to approximate such methods using a quasi-Monte Carlo (QMC) approach. We consider cases where the time-frequency representation is redundant, having feature axes in addition to the ...
    • Efficient photoelectrocatalytic degradation of amoxicillin using nano-TiO<inf>2</inf> photoanode thin films: A comparative study with photocatalytic and electrocatalytic methods 

      Alaydaroos, Alia Husain; Sydorenko, Jekaterina; Palanisamy, Selvakumar; Chiesa, Matteo; Al Hajri, Ebrahim (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-24)
      Excessive utilization of antibiotics in human, animal, and aquaculture poses a substantial threat to human health and the environment. Photoelectrochemical processes are increasingly applied for water remediation because they generate oxidizing species and mineralize organic pollutants, making even small water quantities more amenable for utilization. Thus, this study presents the fabrication of an ...
    • Estimating the Space Debris Density Function using Radar Beam Park Measurements 

      Vierinen, Juha; Hermann, Frank; Kastinen, Daniel; Kero, Johan; Markkanen, Jussi; Grydeland, Tom (Journal article; Tidsskriftartikkel; Peer reviewed, 2023)
      Estimating the density of space debris as a function of orbital elements and size is crucial for determining the risk of collision of spacecraft. For objects 1 cm or larger in diameter, this information can be obtained using beam park observations made with powerful ground based radars. This study presents a novel technique for estimating the density of space debris as a function of orbital elements ...