Fakultet for naturvitenskap og teknologi: Recent submissions
Now showing items 1761-1780 of 5304
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North Atlantic–Norwegian Sea exchanges during the past 135,000 years: Evidence from foraminiferal ∆14C, d11B, d18O, d13C, Mg/Ca, and Cd/Ca
(Doctoral thesis; Doktorgradsavhandling, 2015-07-03)The ocean is an essential regulator of climate through its effect on redistribution of heat and air-sea exchange of greenhouse gases.The modern circulation pattern of surface and deep water between the Arctic Mediterranean seas and North Atlantic is an important part of the global meridional ocean circulation. In this study we investigate the North Atlantic-Norwegian Sea exchanges of heat and carbon ... -
Effects of the tropospheric large-scale circulation on European winter temperatures during the period of amplified Arctic warming
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-08)We investigate factors influencing European winter (DJFM) air temperatures for the period 1979–2015 with the focus on changes during the recent period of rapid Arctic warming (1998–2015). We employ meteorological reanalyses analysed with a combination of correlation analysis, two pattern clustering techniques, and backtrajectory airmass identification. In all five selected European regions, severe ... -
Cyclic Voltammetric Study of 2-Hydroxybenzophenone (HBP) Derivatives and the Correspondent Change in the Orbital Energy Levels in Different Solvents
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-14)The experimental UV and CV of five substituted 2-hydroxybenzophenones in solvents acetonitrile, n-dimethylformamide and dimethylsulfoxide are presented. Results obtained were used to determine their experimental highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and the results were compared to their theoretical model. The derivatives with an electron withdrawing ... -
Infrared Spectroelectrochemistry of Iron-Nitrosyl Triarylcorroles. Implications for Ligand Noninnocence
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-13)Recent DFT calculations have suggested that iron nitrosyl triarylcorrole complexes have substantial {FeNO}<sup>7</sup> −corrole<sup>•2−</sup> character. With this formulation, reduction of Fe(C)(NO) complexes, where C = triarylcorrole, should be centered on the corrole macrocycle rather than on the {FeNO}<sup>7</sup> moiety. To verify this proposition, visible and infrared spectroelectrochemical ... -
Classification of simply-transitive Levi non-degenerate hypersurfaces in C^3
(Journal article; Tidsskriftartikkel; Peer reviewed, 2021-06-24)Holomorphically homogeneous Cauchy–Riemann (CR) real hypersurfaces <i>M<i/><sup>3</sup>⊂C<sup>2</sup> were classified by Élie Cartan in 1932. In the next dimension, we complete the classification of simply-transitive Levi non-degenerate hypersurfaces <i>M<i/><sup>5</sup>⊂C<sup>3</sup> using a novel Lie algebraic approach independent of any earlier classifications of abstract Lie algebras. Central ... -
Chromium evidence for protracted oxygenation during the Paleoproterozoic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-24)It has commonly been proposed that the development of complex life is tied to increases in atmospheric oxygenation. However, there is a conspicuous gap in time between the oxygenation of the atmosphere 2.4 billion years ago (Ga) and the first widely-accepted fossil evidence for complex eukaryotic cells . At present the gap could either represent poor sampling, poor preservation, and/or difficulties ... -
A Lagrangian Snow‐Evolution System for Sea‐Ice Applications (SnowModel‐LG): Part I – Model Description
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-06)A Lagrangian snow-evolution model (SnowModel-LG) was used to produce daily, pan-Arctic, snow-on-sea-ice, snow property distributions on a 25 × 25-km grid, from 1 August 1980 through 31 July 2018 (38 years). The model was forced with NASA's Modern Era Retrospective-Analysis for Research and Applications-Version 2 (MERRA-2) and European Centre for Medium-Range Weather Forecasts (ECMWF) ReAnalysis-5th ... -
Phase transfer catalyzed conjugate addition-initiated ring-closure (CAIRC) reactions with 2-bromo-2-cyclopentenones
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-05-07)When 2-bromo-2-cyclopentenone is treated with various carbon nucleophiles containing active methylenes, it undergoes a conjugate addition initiated-ring closure (CAIRC) reaction. This leads to the formation of carboand heterocyclic compounds in a regioselective fashion with good to high yield. Several bases and phase transfer catalysts were investigated. CsF-Si(OEt)4 as base together with ... -
An averaged polarizable potential for multiscale modeling in phospholipid membranes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-03)A set of average atom-centered charges and polarizabilities has been developed for three types of phospholipids for use in polarizable embedding calculations. The lipids investigated are 1,2-dimyristoyl-sn-glycero-3-phosphocholine, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, and 1-palmitoyl-2-oleoyl-sn-glycerol-3-phospho-L-serine given their common use both in experimental and computational ... -
A Health-Energy Nexus Perspective for Virtual Power Plants: Power Systems Resiliency and Pandemic Uncertainty Challenges
(Chapter; Bokkapittel, 2022-01-01)This chapter introduces and discusses a novel “health-energy nexus under pandemic uncertainty” concept that arises as a consequence of the current pandemic that we are experiencing worldwide. In light of the pandemic implications on the power and energy systems, we discuss how the global health conditions are tightly connected with the energy consumption needs and how the two areas closely interact ... -
Sub-kilometre scale distribution of snow depth on Arctic sea ice from Soviet drifting stations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-04)The sub-kilometre scale distribution of snow depth on Arctic sea ice impacts atmosphere-ice fluxes of energy and mass, and is of importance for satellite estimates of sea-ice thickness from both radar and lidar altimeters. While information about the mean of this distribution is increasingly available from modelling and remote sensing, the full distribution cannot yet be resolved. We analyse 33 539 ... -
1.80–1.75 Ga granite suites in the west Troms Basement Complex, northern Norway: Palaeoproterozoic magma emplacement during advancing accretionary orogeny, from field observations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-25)The Ersfjord Granite is part of a suite of c.1.80–1.75 Ga syeno-granites in the West Troms Basement Complex, northern Norway, presumed to belong to the Transscandinavian Igneous Belt (TIB-1) in the Fennoscandian Shield. Previous data suggest the granite formed post-collisional and ascended as a batholith pluton from a source generated by delamination of mafic-intermediate lower crust. We argue that ... -
Seal characterization and integrity in uplifted basins: Insights from the northern Barents Shelf
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-16)Seal integrity is a key property for petroleum exploration. This is even more the case in uplifted basins, as exemplified by the northern Barents Shelf. Uplift may lead to fracturing, decompaction, gas expansion and fluid flow. Therefore, it is critical to understand the mechanical behaviour of the Jurassic shale caprocks in the Greater Hoop area, where hydrocarbon accumulations are situated as ... -
Luminescence characteristics of Scandinavian quartz, their connection to bedrock provenance and influence on dating results
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-23)The success of optically stimulated luminescence (OSL) dating relies to a large extent on suitable characteristics of the analysed mineral, in this case quartz. Previous OSL dating of Quaternary sediments in Scandinavia has shown that quartz characteristics vary widely across the region, resulting in dating studies with varied success. The aim of this study is to provide an overview of quartz ... -
Hydrocarbon leakage driven by quaternary glaciations in the Barents Sea based on 2D basin and petroleum system modeling
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-25)The Barents Sea has experienced intense erosion throughout the Cenozoic due to uplift and repeated episodes of glaciation. This, in turn, has driven large pressure and temperature fluctuations in the sediment substrate along with rearrangement of thermogenic oil and gas accumulations. As a result, some hydrocarbon fields have relatively shallow depths, and natural gas release is widespread. This ... -
Meta-learning with implicit gradients in a few-shot setting for medical image segmentation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-12)Widely used traditional supervised deep learning methods require a large number of training samples but often fail to generalize on unseen datasets. Therefore, a more general application of any trained model is quite limited for medical imaging for clinical practice. Using separately trained models for each unique lesion category or a unique patient population will require sufficiently large curated ... -
Shearlets as feature extractor for semantic edge detection: The model-based and data-driven realm: Shearlets for Semantic Edge Detection
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-25)Semantic edge detection has recently gained a lot of attention as an image-processing task, mainly because of its wide range of real-world applications. This is based on the fact that edges in images contain most of the semantic information. Semantic edge detection involves two tasks, namely pure edge detection and edge classification. Those are in fact fundamentally distinct in terms of the level ... -
Electronic circular dichroism of fluorescent proteins: A computational study
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-02-03)The electronic circular dichroism (ECD) properties of the green fluorescent protein and other fluorescent proteins have been calculated with density functional theory. The influence of different embedding models on the ECD signal of the chromophore has been investigated by modeling the protein environment by the polarizable continuum model (QM/PCM), by the polarizable embedding model (PE-QM/MM), by ... -
Superposition of semiconductor and semi-metal properties of self-assembled 2D SnTiS3 heterostructures
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-07-15)Two-dimensional metal dichalcogenide/monochalcogenide thin flakes have attracted much attention owing to their remarkable electronic and electrochemical properties; however, chemical instability limits their applications. Chemical vapor transport (CVT)- synthesized SnTiS<sub>3</sub> thin flakes exhibit misfit heterojunction structure and are highly stable in ambient conditions, offering a ... -
Development and Validation of a Safety Leadership Self-Efficacy Scale (SLSES) in Maritime Context
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-21)Extensive studies have highlighted the importance of leadership on safety in the maritime industry. However, current research lacks empirically tested theoretical models with valid and reliable scales for describing and measuring safety leadership in ship operations. This study reports the development and validation process of the first Safety Leadership Self-Efficacy Scale (SLSES) for assessing ...