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
Effect of bitter orange or sweet orange juices on the characteristics of beef sausages
(2025) Cavenaghi-Altemio, Angela D.; Martins, Nathalia B.C.; Fonseca, Gustavo G.; Faculty of Natural Resource Sciences
This study evaluated the effects of replacing water with bitter orange and pear orange juices on the properties of beef sausages. Three formulations were prepared: control with water (F1) and two experimental formulations with bitter orange juice (F2) and pear orange juice (F3). Moisture, protein, lipid, ash, carbohydrate content, pH, water activity, shear force, and instrumental color were analyzed. Formulations complied with legislation for moisture (< 70 %), protein (> 12 %), and lipid (< 30 %) content. Moisture content ranged from 55.96 % (F3) to 60.32 % (F1), with the reduction in F2 and F3 attributed to the soluble solids in the juices. Protein content remained stable across formulations (22.24–23.39 %), reflecting the consistent meat proportion. Lipid content varied significantly, with F1 (15.25 %) showing the lowest value and F3 (19.29 %) the highest due to altered lipid retention influenced by acid-matrix interactions. F2 exhibited the highest acidity (0.40 g 100 mL–¹) and the lowest pH (4.68), leading to the lowest shear force (56.68 N). Due to particularities in the preparation, meat and fat portions were analyzed for colorimetry. Lighter sausages with lower redness (a*) values in F2 (5.20) and F3 (4.48) compared to F1 (8.50), and higher yellowness (b*) in F2 (7.26) were observed for the meat portion. The total color difference (ΔE*) values indicated noticeable differences, particularly for F2 and F3 in the meat portion and F3 in the fat portion. These findings demonstrated that orange juices can modify the properties of beef sausages, enhancing their functional attributes, offering opportunities for the development of new food products.
Behavioral interventions as treatment for insomnia – A scoping review of randomized controlled trials
(2026-02) Hodge, Brad; Richert, Elena; Schmitz, Lisa; Islind, Anna Sigridur; Leppänen, Timo; McNicholas, Walter T.; Arnardóttir, Erna Sif; Pires, Gabriel Natan; Department of Psychology; Department of Engineering; Department of Computer Science
Objective To map behavioral interventions evaluated as a potential treatment for insomnia in previous randomized controlled trials (RCTs) through a scoping review. Methods A bibliographic search was performed to gather RCTs evaluating behavioral interventions for insomnia, either diagnosed according to standardized criteria or limited to moderate to severe symptoms. Behavioral interventions included should be: 1. Focused on modifying behaviors that affect sleep, 2. Self-implementable, 3. Suitable for home implementation, and 4. Not depending on or using cognitive/emotional processes. Behavioral interventions were categorized as “increasing/engaging”, “reducing/avoiding”, and “adjusting/modifying” behaviors. Results Forty-nine RCTs were included, with an average of 1.8 RCTs per year and peak publication record in 2015 and 2023 (k = 6 each). Adjusting/modifying behavior interventions were the most frequent (k = 32, 65.3 %), followed by increasing/engaging behaviors (k = 18, 36.7 %). Among individual interventions, multi-component behavioral therapy with sleep restriction was the most common (k = 17, 34.7 %), followed by sleep restriction alone (k = 9, 18.4 %), yoga and tai chi (k = 6, 12.2 %) and physical exercise (k = 6, 12.2 %). Another nine interventions were listed, with one to four RCTs each. Conclusion Despite the ubiquity of advice to practice good sleep hygiene to improve sleep quality, these findings highlight the need for high-quality randomised trials examining which behavioural interventions lead to improved sleep, as many currently being recommended do not have an adequate evidence base.
Environmental Sustainability of Hydropower and Its Adaptation to Climate Change
(2026) Patro, Epari Ritesh; Balouchi, Behnam; Gosselin, Marie-Pierre; Aparicio, Maria Ubierna; Finger, David Christian; Department of Engineering
Vector-Valued Robust Stochastic Control
(2026-07-14) Cialenco, Igor; Kováčová, Gabriela; Department of Engineering
We study a dynamic stochastic control problem subject to Knightian uncertainty with multiobjective (vector-valued) criteria. Assuming the preferences across expected multiloss vectors are represented by a given, yet general, preorder, we address the model uncertainty by adopting a robust or minimax perspective, minimizing expected loss across the worst-case model. For loss functions taking scalar values, there is no ambiguity in interpreting supremum and infimum. In contrast, major challenges for multi-loss control problems include properly defining and interpreting the notions of supremum and infimum, as well as addressing their non-uniqueness. To deal with these, we employ the notion of an ideal point vector-valued supremum for the robust part of the problem, while we view the control part as a multi-objective (or vector) optimization problem. Using a set-valued framework, we derive both a weak and a strong version of the dynamic programming principle (DPP) or Bellman equations for two appropriately chosen value functions: the collection of all worst expected losses across all feasible actions, and for its upper image. The weak version of Bellman's principle is proved under minimal assumptions. To establish a stronger version of DPP, we introduce the rectangularity property with respect to a general preorder. We also show that the weak minimizers obey the time consistency property. Finally, we study the important particular case of component-wise partial order of vectors, and conclude with some illustrative examples motivated by financial problems.
THz generation in a DC diode with base resistor
(Institute of Electrical and Electronics Engineers Inc., 2026) Alexandersson, Bjarttor Steinn; Torfason, Kristinn; Manolescu, Andrei; Valfells, Agust; Department of Engineering
We have recently discovered a novel mechanism for generating oscillating current at THz frequency in a DC vacuum microdiode with a series resistor. We performed simulations of field emission in a planar microdiode with an appreciable resistor and observed the emergence of regular oscillations in the diode current due to loading of the resistor modulating the surface electric field and subsequently the emission [1]. Here we extend our previous work to examine how field enhancement at the cathode surface affects the operating parameters. It is shown that using field emitter arrays the voltage can be reduced significantly while maintaining a robust diode current oscillating in the THz frequency range. Using molecular dynamics simulations, we show how the configuration of the field emitter array, in the context of other diode parameters, affects the performance of the oscillator.
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