Opin vísindi
Opin vísindi er varðveislusafn vísindaefnis og doktorsritgerða í opnum aðgangi á vegum íslenskra háskóla og Landsbókasafns Íslands - Háskólabókasafns.
Opinn aðgangur að rannsóknaniðurstöðum er í samræmi við 10. gr. laga nr. 3/2003 um opinberan stuðning við vísindarannsóknir sem og kröfur innlendra og erlendra rannsóknasjóða. Markmiðið með opnum aðgangi er að niðurstöður rannsókna séu aðgengilegar sem flestum óhindrað og án endurgjalds á rafrænu formi. Vistun í varðveislusafninu er varanleg og ætlað að tryggja aðgang að vísindaefni íslenskra háskóla í opnum aðgangi um ókomna tíð. Varðveislusafnið Opin vísindi er tengt við rannsóknagáttina IRIS og rannsóknaniðurstöður í opnum aðgangi sem eru skráðar í IRIS eru um leið vistaðar og gerðar aðgengilegar til framtíðar í varðveislusafninu. Með því að safna þessu efni saman í eitt safn verður aðgangur að því einfaldur og þægilegur fyrir alla sem vilja kynna sér það og geta þannig notið þess öfluga vísindastarfs sem fram fer í háskólum landsins.
Varðveislusafnið er OpenAIRE / OpenAIREplus samhæft og samrýmist kröfum sem gerðar eru um birtingu rannsóknaniðurstaðna úr verkefnum sem styrkt eru úr evrópsku rannsóknaáætlununum FP7 og H2020.
Varðveislusafnið notar opna hugbúnaðinn DSpace.
Opinn aðgangur að rannsóknaniðurstöðum er í samræmi við 10. gr. laga nr. 3/2003 um opinberan stuðning við vísindarannsóknir sem og kröfur innlendra og erlendra rannsóknasjóða. Markmiðið með opnum aðgangi er að niðurstöður rannsókna séu aðgengilegar sem flestum óhindrað og án endurgjalds á rafrænu formi. Vistun í varðveislusafninu er varanleg og ætlað að tryggja aðgang að vísindaefni íslenskra háskóla í opnum aðgangi um ókomna tíð. Varðveislusafnið Opin vísindi er tengt við rannsóknagáttina IRIS og rannsóknaniðurstöður í opnum aðgangi sem eru skráðar í IRIS eru um leið vistaðar og gerðar aðgengilegar til framtíðar í varðveislusafninu. Með því að safna þessu efni saman í eitt safn verður aðgangur að því einfaldur og þægilegur fyrir alla sem vilja kynna sér það og geta þannig notið þess öfluga vísindastarfs sem fram fer í háskólum landsins.
Varðveislusafnið er OpenAIRE / OpenAIREplus samhæft og samrýmist kröfum sem gerðar eru um birtingu rannsóknaniðurstaðna úr verkefnum sem styrkt eru úr evrópsku rannsóknaáætlununum FP7 og H2020.
Varðveislusafnið notar opna hugbúnaðinn DSpace.
Nýlega bætt við
Nitroxide- and trityl-based polarizing agents for MAS-DNP: Synthesis, mechanistic insights, and applications
(University of Iceland, School of Engineering and Natural Sciences, Faculty of Physical Sciences, 2026-09-14) Chatterjee, Satyaki; Snorri Þór Sigurðsson; Faculty of Physical Sciences (UI); Raunvísindadeild (HÍ); School of Engineering and Natural Sciences (UI); Verkfræði- og náttúruvísindasvið (HÍ)
Dynamic nuclear polarization (DNP) is a powerful technique for enhancing the sensitivity of nuclear magnetic resonance (NMR) spectroscopy, enabling the investigation of complex materials and biological systems that are otherwise difficult to analyze. In magic-angle spinning (MAS) under solid-state NMR, the cross-effect mechanism employs biradical polarizing agents to transfer electron polarization to surrounding nuclei. However, many polarizing agents remain difficult to synthesize, often suffer from limited aqueous solubility, and the factors governing polarization transfer are not entirely understood. This thesis describes the design, synthesis, and mechanistic investigation of nitroxide- and trityl-based polarizing agents for MAS-DNP. A high-yielding and step-efficient molecular scaffold, AsymPol-Ester, was synthesized as a versatile precursor for developing watersoluble AsymPol-derivatives of both ionic and non-ionic character, functionalized with carboxylate, phosphate, and glucosamine groups. These derivatives were obtained up to seven-fold higher overall yields than previous analogues while maintaining comparable DNP performance. Systematic structural modifications of AsymPols including linker geometry, conformational flexibility and deuteration revealed that DNP efficiency is not only influenced by electron-spin interactions but also by electron-electron coupling. For trityl-nitroxide biradicals, adding spirocycles on nitroxide reduced DNP sensitivity, that benefit bis-nitroxides, unexpectedly revealed a distinct polarization transfer mechanism in trityl-nitroxide biradicals. Further, nuclear-nuclear double resonance (NUDOR) experiments demonstrated that polarization transfer in trityl-nitroxide biradicals is strongly influenced by the large difference in electron-relaxation rates between the two radicals, in contrast to bisnitroxides where electron-electron coupling governs polarization transfer. In addition, tritylnitroxide derivative, TritylTEMPO-X, with six-fold higher aqueous solubility than PyrroTriPol, was synthesized. Finally, application-specific nitroxide radicals were developed for site-directed spin-labeling of biomolecules for local DNP enhancement, and mono-radicals for incorporation into mesoporous organosilica materials.
How different life-history strategies respond to changing environments : A multi-decadal study of groundfish communities
(2025-12) Sólmundsson, Jón; Sigurðsson, Ólafur; Jónsdóttir, Ingibjörg G.; Jónsson, Steingrímur; Faculty of Natural Resource Sciences
In recent decades, climate variability has led to significant shifts in the distribution and prevalence of various fish species in the North Atlantic. These changes are well documented for several groundfish species within the zoogeographical transition waters surrounding Iceland, coinciding with variations in seawater temperature. This study analyses groundfish assemblage structure through the frameworks of life-history theory and biogeography. Utilizing annual bottom trawl survey data from 1987 to 2024, groundfish species in the continental shelf waters around Iceland were categorized into three primary life-history strategies: periodic, opportunistic, and equilibrium, based on their life-history traits. Over the study period, these strategies demonstrated distinct responses to environmental changes, influenced by the biogeography of the species. Increased water temperatures were accompanied by an influx of Atlantic and Boreal species, while species richness for Arctic fish remained similar or decreased. Boreal periodic species emerged as the most prominent in Icelandic waters, maintaining long-term stability in abundance and distribution. However, environmental conditions in recent decades have favoured southerly warmer-water (Atlantic) species across life-history strategies, while most Arctic species have experienced declining abundance trends. Opportunistic strategists exhibited the most pronounced temporal changes during the warming period.
Cross-cultural validation of the profile of mood scale : evaluation of the psychometric properties of short screening versions
(2025) Schmalbach, Ileana; Schmalbach, Bjarne; Aghababa, Alireza; Brand, Ralf; Chang, Yu Kai; Çiftçi, Muhammet Cihat; Elsangedy, Hassan; Fernández Gavira, Jesús; Huang, Zhijian; Kristjánsdóttir, Hafrún; Mallia, Luca; Nosrat, Sanaz; Pesce, Caterina; Rafnsson, Daði; Medina Rebollo, Daniel; Timme, Sinika; Brähler, Elmar; Petrowski, Katja; Department of Sport Science; Department of Psychology
The Profile of Mood States (POMS) is one of the most widely applied scales for measuring mood. Considering the advantages of short scales and increased international research, the aim of the present study was to evaluate cross-culturally the psychometric properties of a short 16-item version of the POMS. Data were collected from 15,693 participants across 10 different countries worldwide. Initially, we identified the original versions of the POMS in various languages. Subsequently, we selected 16 items based on the previously validated short form (POMS-16) for analysis. Psychometric properties of the POMS were then evaluated in samples from each studied population for each language version. Confirmatory factor analysis was conducted to assess its invariance across age groups and gender, alongside reliability estimation. Most language versions of the POMS-16 showed a good fit with the four-factor model, except for the Chinese (traditional) and Turkish versions. Reliability was generally high, except for the Vigor subscale in a small subset of languages. Regarding measurement invariance, the majority of language versions were invariant across gender and age groups, except for the Farsi language version across gender, and the Chinese, Farsi, Finnish, and Turkish versions across age. These findings enhance the cross-cultural applicability of the POMS-16, contributing to its utility in diverse populations and thus enhancing the comparability of the results. In addition, we introduced the first versions of the POMS in Farsi, Finnish, and Icelandic.
AI-based estimator for computational discovery and synthesis of customized microwave absorbing materials
(2023-09-07) Yadav, Ravi; Panwar, Ravi; Department of Engineering
This article investigates the viability of a deep neural network (DNN) for the computational discovery and synthesis of efficient microwave-absorbing materials and structures. A DNN is trained to tackle specific objectives in a constrained environment by utilizing the conventional forward and reverse approaches. In the forward approach, the DNN predicts various topologies of the absorbers and it is found to be effective in determining the stacking sequence of microwave-absorbing materials and their associated thicknesses. Designing a microwave absorber is observed to be exceptionally cumbersome utilizing a DNN if the material database increases unexpectedly. Following that, the solution is offered by addressing the reverse approach, in which a DNN is utilized to forecast the electromagnetic (EM) properties based on user-defined specifications. It is a convincing and simple method of designing thin and wideband customized absorbers. DNN prediction is authenticated by fabricating two distinct absorbers based on the frequency-dependent EM properties. Furthermore, the synthesized model is tested and validated with the response of the EM mixing model and microwave measurements. The suggested DNN strategy can effectively fix the issues in designing thin and broadband absorbers.
An infrastructure for robotic applications as cloud computing services
(2014) Mouradian, Carla; Errounda, Fatima Zahra; Belqasmi, Fatna; Glitho, Roch; Department of Computer Science
Robotic applications are becoming ubiquitous. They are widely used in several areas (e.g., healthcare, disaster management, and manufacturing). However, their provisioning still faces several challenges such as cost and resource usage efficiency. Cloud computing is an emerging paradigm that may aid in tackling these challenges. It has three main facets: Infrastructure as a Service (IaaS), Platform as a Service (PaaS) and Software as a Service (SaaS). This paper focuses on the IaaS aspects of robotic applications as cloud computing services. It proposes an architecture that enables cost efficiency through virtualization and dynamic task delegation to robots, including robots that might belong to other clouds. Overlays and RESTful Web services are used as cornerstones. A prototype is built using LEGO Mindstorms NXT as the robotic platform, and JXTA as the overlay middleware. Related work is reviewed, the functional entities and interfaces of the architecture are described, and the prototype architecture is presented along with the implemented scenario.
Flokkar í Opnum vísindum
Veldu flokk til að skoða.
- University of Iceland
- University of Akureyri
- Bifröst University
- Hólar University College
- IRIS
- Agricultural University of Iceland
- National and University Library of Iceland
- Iceland University of the Arts