Fakultet for naturvitenskap og teknologi: Recent submissions
Now showing items 2121-2140 of 5378
-
Distribution and Abundances of Planktic Foraminifera and Shelled Pteropods During the Polar Night in the Sea-Ice Covered Northern Barents Sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-22)Planktic foraminfera and shelled pteropods are important calcifying groups of zooplankton in all oceans. Their calcium carbonate shells are sensitive to changes in ocean carbonate chemistry predisposing them as an important indicator of ocean acidification. Moreover, planktic foraminfera and shelled pteropods contribute significantly to food webs and vertical flux of calcium carbonate in polar pelagic ... -
Microbial activity, methane production, and carbon storage in Early Holocene North Sea peats
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-11)<p>Northern latitude peatlands act as important carbon sources and sinks, but little is known about the greenhouse gas (GHG) budgets of peatlands that were submerged beneath the North Sea during the last glacial–interglacial transition. <p>We found that whilst peat formation was diachronous, commencing between 13 680 and 8360 calibrated years before the present, stratigraphic layering and local ... -
The Billefjorden Fault Zone north of Spitsbergen: a major terrane boundary?
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-13)The Billefjorden Fault Zone is a major terrane boundary in the Norwegian Arctic. The fault separates basement rocks of Svalbard’s north-eastern and north-western terranes that recorded discrete Precambrian tectonothermal histories and were accreted, intensely deformed and metamorphosed during the Caledonian Orogeny. Although the fault represents a major, crustal-scale tectonic boundary, its north-ward ... -
Evaluation of a sub-kilometre NWP system in an Arctic fjord-valley system in winter
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-28)Terrain challenges the prediction of near-surface atmospheric conditions, even in kilometre-scale numerical weather prediction (NWP) models. In this study, the ALADIN-HIRLAM NWP system with 0.5 km horizontal grid spacing and an increased number of vertical levels is compared to the 2.5-km model system similar to the currently operational NWP system at the Norwegian Meteorological Institute. The ... -
The Tipping Effect of Delayed Interventions on the Evolution of COVID-19 Incidence
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-04-23)We combine infectious disease transmission and the non-pharmaceutical (NPI) intervention response to disease incidence into one closed model consisting of two coupled delay differential equations for the incidence rate and the time-dependent reproduction number. The model contains three parameters, the initial reproduction number, the intervention strength, and the response delay. The response is ... -
Gruppelærerdagen – trygghet og kvalitet fra første undervisningstime
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-24)En stor del av undervisningen i realfagene ved norske universiteter blir utført av stipendiater eller studenter fra tidligere kull. Fokus på opplæring av denne gruppen undervisere kan bidra til en positiv effekt på undervisningskvalitet og studentenes læring. Det varierer imidlertid fra institusjon til institusjon om det finnes en slik type opplæring og omfang og kvalitet på denne opplæringen kan ... -
Teaching with digital geology in the high Arctic: opportunities and challenges
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-28)<p>The Covid-19 pandemic occurred at a time of major revolution in the geosciences – the era of digital geology. Digital outcrop models (DOMs) acquired from consumer drones, processed using user-friendly photogrammetric software and shared with the wider audience through online platforms are a cornerstone of this digital geological revolution. Integration of DOMs with other geoscientific data, such ... -
Assessing the impact of the securitization narrative on climate change adaptation in Nigeria
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-01)In Nigeria, the threat posed by climate change is leading policymakers and the media to frame climate change as a security threat that warrants support for adaptive actions. We draw upon securitization theory to examine how security narratives affect climate change adaptation. Using primary and secondary data, we find that although securitization arguments are easily identified in climate change ... -
Harmonic Infrared and Raman Spectra in Molecular Environments Using the Polarizable Embedding Model
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-19)We present a fully analytic approach to calculate infrared (IR) and Raman spectra of molecules embedded in complex molecular environments modeled using the fragment-based polarizable embedding (PE) model. We provide the theory for the calculation of analytic second-order geometric derivatives of molecular energies and first-order geometric derivatives of electric dipole moments and dipole–dipole ... -
A Green, Scalable, One-Minute Synthesis of Benzimidazoles
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-24)Herein is reported a substantially improved synthesis of 2-substituted benzimidazoles by condensation of 1,2-diaminoarenes and aldehydes using methanol as the reaction medium. The developed method afforded moderate to excellent yields (33-96%) at ambient temperature, displays high functional group tolerance, is conducted open to air, and requires only one-minute reaction time under catalyst- ... -
Ni(I)–Alkyl Complexes Bearing Phenanthroline Ligands: Experimental Evidence for CO2 Insertion at Ni(I) Centers
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-10)Although the catalytic carboxylation of unactivated alkyl electrophiles has reached remarkable levels of sophistication, the intermediacy of (phenanthroline)Ni(I)–alkyl species—complexes proposed in numerous Ni-catalyzed reductive cross-coupling reactions—has been subject to speculation. Herein we report the synthesis of such elusive (phenanthroline)Ni(I) species and their reactivity with CO<sub>2</sub>, ... -
Free-standing tantalum pentoxide waveguides for gas sensing in the mid-infrared
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-23)Typical applications of integrated photonics in the mid-infrared (MIR) are different from near-infrared (telecom) range and, in many instances, they involve chemical sensing through MIR spectroscopy. Such applications necessitate tailored designs of optical waveguides. Both cross-sectional designs and processing methods of MIR waveguides have been a subject of extensive research, where material ... -
A Comparative Study of Statistical Techniques for Prediction of Meteorological and Oceanographic Conditions: An Application in Sea Spray Icing
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-17)Environmental conditions in Arctic waters pose challenges to various offshore industrial activities. In this regard, better prediction of meteorological and oceanographic conditions contributes to addressing the challenges by developing economic plans and adopting safe strategies. This study revolved around simulation of meteorological and oceanographic conditions. To this aim, the applications of ... -
The role of Ediacaran synkinematic anatectic rocks and the late-orogenic charnockitic rocks in the development of the hot Araçuaí belt
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-13)The orogenic evolution of the hot Araçuaí belt is characterized by continuous magmatic activity, with magmas of different compositions recording a long-lived (∼630 to ∼530 Ma) tectono-thermal evolution in response to convergence between the Congo and São Francisco continents during the West Gondwana amalgamation. Geochemical data from the Carlos Chagas domain (CCD) and the Nova Venécia Complex (NVC), ... -
Recognizing potential of LiDAR for comprehensive measurement of sea spray flux for improving the prediction of marine icing in cold conditions - A review
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-06)Marine icing phenomenon depends on multiple variables like vessel characteristics and uncertain factors like environmental parameters, developing an accurate model for its forecasting, evaluation, and estimation is very challenging. Commonly, most severe ice accretion is caused due to sea spray. The past attempts to measure impinging sea spray flux were carried out on specific parts of the spray ... -
Drone-based Bridge Inspection in Harsh Operating Environment: Risks and safeguards
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-30)The inability to effectively and systematically identify and measure the damage in bridges will lead to an acceleration and dangerous deterioration of the health state of these structures. To repair and replace the aging and damaged bridge infrastructures, and prevent catastrophic bridge collapse, there is an urgent need to develop reliable, innovative, and efficient approaches to the performance ... -
Structural and functional variation of chitin-binding domains of a lytic polysaccharide monooxygenase from Cellvibrio japonicus
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-17)Among the extensive repertoire of carbohydrate-active enzymes, lytic polysaccharide monooxygenases (LPMOs) have a key role in recalcitrant biomass degradation. LPMOs are copper-dependent enzymes that catalyze oxidative cleavage of glycosidic bonds in polysaccharides such as cellulose and chitin. Several LPMOs contain carbohydrate-binding modules (CBMs) that are known to promote LPMO efficiency. ... -
Assessing the relationship between living benthic foraminifera and methane emission in the Arctic Ocean
(Doctoral thesis; Doktorgradsavhandling, 2021-11-04)Methane is a powerful greenhouse gas. In marine environments, it is buried deep in the sediments in the form of gas hydrate, an ice-like structure. Due to its form, gas hydrate is sensitive to changes in temperature and pressure. Because of that, the ongoing climate change can trigger destabilization of its sub-seabed deposits. This may result in a release of great amounts of methane into the ... -
Experiences Building and Deploying Wireless Sensor Nodes for the Arctic Tundra
(Journal article; Tidsskriftartikkel, 2021-08-02)The arctic tundra is most sensitive to climate change. The change can be quantified from observations of the fauna, flora and weather conditions. To do observations at sufficient spatial and temporal resolution, ground-based observation nodes with sensors are needed. However, the arctic tundra is resource-limited with regards to energy, data networks, and humans. There are also regulatory and practical ... -
The Pseudoalteromonas multipartite genome: distribution and expression of pangene categories, and a hypothesis for the origin and evolution of the chromid
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-21)Bacterial genomes typically consist of one large chromosome, but can also include secondary replicons. These so-called multipartite genomes are scattered on the bacterial tree of life with the majority of cases belonging to Proteobacteria. Within the class gamma-proteobacteria, multipartite genomes are restricted to the two families <i>Vibrionaceae</i> and <i>Pseudoalteromonadaceae</i>. Whereas the ...