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
Bioactive compounds, antioxidant activity, and maturation effects in bitter and sweet orange juices
(2025-05-05) Cavenaghi-Altemio, Angela Dulce; Martelli, Silvia Maria; Fonseca, Gustavo Graciano; Faculty of Natural Resource Sciences
Bitter oranges (Citrus aurantium) and sweet oranges (Citrus sinensis) are commercially important citrus fruits with distinct uses and characteristics. Bitter oranges, primarily used as a flavoring agent, are rich in bioactive compounds, while sweet oranges dominate global citrus juice production. This study evaluated bitter orange juice at three maturation stages, comparing its physical, chemical, and bioactive properties with pasteurized pear orange juice (C. sinensis). Parameters assessed included water activity, pH, total titratable acidity, total soluble solids, maturation index, vitamin C content, total phenolic (TP) content, total flavonoid (TF) content, and antioxidant activity. The results showed that the vitamin C content in bitter oranges decreased with ripening but remained comparable to pear orange juice in the ripe stage. TPs and TFs were highest in pasteurized pear orange juice, reflecting the stability of these compounds during thermal processing. The antioxidant activity varied significantly across bitter orange maturation stages, with intermediate fruits demonstrating the strongest capacity. However, the maturation stage had limited influence on the antioxidant activity compared to pear orange juice. Bitter orange juices, despite being less commercially prominent, offer distinct bioactive advantages and antioxidant potential. Future research should explore optimizing maturation and processing methods to enhance the nutritional and functional properties of bitter orange juices.
A Wideband Circularly Polarized Antenna Using Substrate Integrated Waveguide and Truncated-Corner Patch Loaded Slot
(2023-07) Agrawal, Meha; Kumar, Trivesh; Department of Engineering
A wideband circularly polarized antenna based on the substrate integrated waveguide (SIW) is investigated and presented for mobile satellite applications. Initially, a rectangular-slot is etched on the top layer of the SIW cavity. A truncated patch from the one corner (top left) is loaded inside the slot to obtain the two pairs of orthogonal degenerate modes TE130/TE310 and TE230/TE320. This truncated-corner patch helps to bring the orthogonal modes closer to obtain the wideband circular polarization. Further, a rotated rectangular-slot is incorporated inside the patch to enhance the circular polarization bandwidth. The antenna exhibits a relative impedance bandwidth of 20% (10.87–3.275 GHz) and an axial ratio bandwidth 11.50–12.26 GHz (6.4%). The broadside radiation characteristics are achieved with the peak gain of 6.3dBic and 7.0dBic at the two working frequencies 11.5 GHz and 12.0 GHz respectively.
Beta burst dynamics in the motor cortex are reshaped through sensorimotor refinement
(2026) Schipper, Kate; Hassan, Mahmoud; Draganski, Bogdan; Ruggeri, Paolo; Barral, Jérôme
Beta-band activity (15–30 Hz) in motor cortex is closely linked to movement-related processing, yet its transient burst dynamics during long-term learning remain poorly understood. We used high-density electroencephalography (HD-EEG) to examine how beta bursts change over nine sessions of a bimanual coordination task, under adaptive and non-adaptive training conditions. Both training conditions led to motor skill learning, with the adaptive group improving more during training, but the non-adaptive group showing better retention. With training, contralateral primary motor cortex showed stronger beta desynchronization during movement and greater synchronization after movement. These changes reflected underlying burst dynamics: post-movement bursts became more temporally confined and consistent, with increased probability and reduced timing variability across sessions. Only the adaptive group showed a session-related increase in burst amplitude. These results demonstrate that beta burst features reorganize with practice, providing a temporally precise neural readout of training progression and revealing how different learning conditions shape cortical dynamics over time.
Assessing the adoption of security policies by developers in terraform across different cloud providers
(2025-06) Verdet, Alexandre; Hamdaqa, Mohammad; Silva, Leuson Da; Khomh, Foutse
Cloud computing has become popular thanks to the widespread use of Infrastructure as Code (IaC) tools, allowing the community to manage and configure cloud infrastructure using scripts. However, the scripting process does not automatically prevent practitioners from introducing misconfigurations, vulnerabilities, or privacy risks. As a result, ensuring security relies on practitioners’ understanding and the adoption of explicit policies. To understand how practitioners deal with this problem, we perform an empirical study analyzing the adoption of scripted security best practices present in Terraform files, applied on AWS, Azure, and Google Cloud. We assess the adoption of these practices by analyzing a sample of 812 open-source GitHub projects. We scan each project’s configuration files, looking for policy implementation through static analysis (Checkov and Tfsec). The category Access policy emerges as the most widely adopted in all providers, while Encryption at rest presents the most neglected policies. Regarding the cloud providers, we observe that AWS and Azure present similar behavior regarding attended and neglected policies. Finally, we provide guidelines for cloud practitioners to limit infrastructure vulnerability and discuss further aspects associated with policies that have yet to be extensively embraced within the industry.
A Semicircular Substrate Integrated Waveguide- Based Self-Diplexing Slot Antenna With Polarization Flexibility
(2023-07-01) Agrawal, Meha; Kumar, Trivesh; Department of Engineering
The substrate integrated waveguide (SIW) based self-diplexing antenna having polarization flexibility is presented in this letter for satellite communications. The presented self-diplexing antenna can provide the linear polarization, right-hand circular polarization, and left-hand circular polarization at the two closely spaced frequencies with the respective port. The antenna is realized on a semicircular SIW cavity, which is further modified to form the two dominant mode quadrant cavities by incorporating a via wall at the center of the semicircular cavity. The different polarizations are achieved by changing the orientation of the radiating slots. The linear polarization is achieved by loading the curved slots in a back-to-back manner and circular polarization in a crossed manner. The resonant frequencies can be tuned with the help of the length of the slots. The equivalent circuit model of the proposed antenna is developed and the equivalent parameters are extracted. The testing of two fabricated antenna prototypes with different polarizations is presented here.
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