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norskFakultet for naturvitenskap og teknologi: Recent submissions
Now showing items 3161-3180 of 5336
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Strukturell kontroll av stratiform jernmalm ved Kvannevann øst, Dunderlandsdalen, Nordland
(Master thesis; Mastergradsoppgave, 2019-05-16)Stratiform jernmalm av verdensklasse fremgår i Dunderlandsdalen, der de prinsipielle malmmineralene består av hematitt og magnetitt. Jernmalmen tilhører Dunderlandsformasjonen, som er del av Ramnålidekket innenfor Rødingsfjell dekkekompleks i det øverste allokton av den kaledonske fjellkjeden. Sidebergartene til jernmalmen består av godt folierte glimmerskifere, metapsammitter og tykke lagpakker av ... -
3D-seismic interpretation of the glacial deposits in the outer Ingøydjupet area, SW Barents Sea. Ice sheet dynamics reconstructed from glacial landforms
(Master thesis; Mastergradsoppgave, 2019-05-15)The late Quaternary evolution of the outer Ingøydjupet area (SW Barents Sea) is studied using a merge of conventional 3D-seismic cubes and a new generation of high-resolution 3D-seismic (TopSeis). The glacigenic sequence is subdivided into five main seismic units: unit A1 (oldest) to A5. These are separated by six glacially eroded boundaries: the Upper Regional Unconformity (URU), intra-glacial ... -
Geochemistry of the stratiform iron Dunderlandsdalen deposits, Nordland
(Master thesis; Mastergradsoppgave, 2019-05-15)The Dunderlandsdalen iron district, Northern Norway, hosts a world-class stratiform Fe-mineralization (total tonnage of ~500 Mt at 33% Fe). The iron ore units belong to the Dunderland Formation in the Ramnålia Nappe, which further belongs to the Rødingsfjellet Nappe of the Caledonian Uppermost Allochthon. Hematite and magnetite represent the principal ore minerals and are hosted by amphibolite grade ... -
Late Weichselian and Holocene glacier dynamics and sedimentary processes in and north of the Wijdefjorden-Austfjorden fjord system, north Spitsbergen
(Master thesis; Mastergradsoppgave, 2019-05-16)Multi-proxy analyses (lithostratigraphy, physical properties, XRF core scanning, and grain size analysis) of five sediment cores and high resolution seismic (chirp) data were integrated to reconstruct the Late Weichselian and Holocene sedimentary environments and glacial history in and on the shelf north of Wijdefjorden. Three acoustic units (U1-U3) correlating with three lithostratigraphic units ... -
Modeling of photovoltaic power generation and electric vehicles charging on city-scale: A review
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-19)<p>Photovoltaics (PV) and electric vehicles (EVs) are promising technologies for increasing energy efficiency and the share of renewable energy sources in power and transport systems. As regards the deployment, use and system integration of these technologies, spatio-temporal modeling of PV power production and EV charging is of importance for several purposes such as urban planning and power grid ... -
Gaussian Markov random field priors in ionospheric 3D multi-instrument tomography
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-22)In ionospheric tomography, the atmospheric electron density is reconstructed from different electron density related measurements, most often from ground-based measurements of satellite signals. Typically, ionospheric tomography suffers from two major complications. First, the information provided by measurements is insufficient and additional information is required to obtain a unique solution. ... -
Seismic sequence analysis and petroleum system indicators at the Oligocene-Miocene level in the southern North Sea
(Master thesis; Mastergradsoppgave, 2019-05-14)A thorough review of the Oligocene-Miocene stratigraphic evolution and depositional environments in the Norwegian part of the southern North Sea is presented and considered alongside observations of petroleum system indicators, from seismic-, core- and well-data. The reconstructed paleo-environments show a trend of fluctuating eustatic sea-levels, controlled by basin subsidence and uplift of the ... -
Bistatic Observations of the Ocean Surface with HF Radar, Satellite and Airborne Receivers
(Journal article; Peer reviewed, 2017-12-25)A new concept has been developed which can view vast regions of the Earth’s surface. Ground HF transmissions are reflected by the ionosphere to illuminate the ocean over a few thousand kilometers. HF receivers detect the radio waves scattered by the sea and land surface. Using the theory of radio wave scatter from ocean surfaces, the HF data is then processed to yield the directional wave-height ... -
Direct 40Ar/39Ar K‐feldspar dating of Late Permian–Early Triassic brittle faulting in Northern Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-04-23)While the offshore post‐Caledonian extensional history of the north Norwegian passive margin is well constrained, the tectonic relationship between onshore and offshore regions is less clear because of limited age constraints on the timing of rifting onshore. <sup>40</sup>Ar/<sup>39</sup>Ar dating of K‐feldspar from hydrothermally altered fault rocks in a Precambrian gneiss complex in northern Norway ... -
EISCAT 3D: the next generation international atmosphere and geospace research radar
(Journal article; Tidsskriftartikkel, 2019)EISCAT_3D is the next generation international atmosphere- and geospace research radar under development in Arctic Europe. Construction have started in September 2017 and the radar system is expected to be operational in the end of 2021. The EISCAT_3D facility will be distributed across three sites in Northern Scandinavia - in Skibotn, Norway, near Kiruna in Sweden, and near Karesuvanto in Finland. ... -
Next-generation Space Object Radar Tracking Simulator: SORTS++
(Journal article; Tidsskriftartikkel, 2019)We describe the software toolbox SORTS++ which is the next-generation Space Object Radar Tracking Simulator (SORTS). This toolbox is able to simulate general Space Surveillance and Tracking (SST) applications from catalogue maintenance to cold-start performance for radar systems or collections of radar systems. We have applied this toolbox to the EISCAT 3D radar system, currently under construction, ... -
2018 Beam-park observations of space debris with the EISCAT radars
(Journal article; Tidsskriftartikkel, 2019)Monitoring the evolution of the space debris environment requires regular radar observations of the space debris population. This study presents the results from 24 hours of beam-park observations of space objects conducted simultaneously with the EISCAT Svalbard and Tromsø radars on and between January 4th and 5th, 2018. The measurements are processed with a new matched filter bank analysis program, ... -
Quad-Polarimetric SAR for Detection and Characterization of Icebergs
(Conference object; Konferansebidrag, 2016)This paper evaluates the performance of fully polarimetric SAR data in iceberg detection and characterization. The study aims to explore the potential of RADARSAT-2 SAR data to detect icebergs and growlers in Svalbard that have broken off from the glaciers nearby. To be able to detect iceberg/growlers in a SAR image, a significant contrast between iceberg and background clutter is required. The ... -
Non-gaussian clustering of SAR images for glacier change detection
(Journal article; Tidsskriftartikkel, 2010-12)Our aim is to use unsupervised, non-Gaussian clustering of Arctic glaciers for post-classification change detection. Firstly, we demonstrate the consistency of non-Gaussian clustering algorithms for Envisat ASAR images by characterizing the expected random error level for different SAR acquisition conditions (such as incidence angle). This allows us to determine whether an observed variation is ... -
Design and Biological Evaluation of Antifouling Dihydrostilbene Oxime Hybrids
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-13)By combining the recently reported repelling natural dihydrostilbene scaffold with an oxime moiety found in many marine antifoulants, a library of nine antifouling hybrid compounds was developed and biologically evaluated. The prepared compounds were shown to display a low antifouling effect against marine bacteria but a high potency against the attachment and growth of microalgae down to MIC ... -
Exploring the transcriptome of luxI- and ΔainS mutants and the impact of N-3-oxo-hexanoyl-L- and N-3-hydroxy- decanoyl-L-homoserine lactones on biofilm formation in Aliivibrio salmonicida
(Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-30)<i>Background</i>: Bacterial communication through quorum sensing (QS) systems has been reported to be important in coordinating several traits such as biofilm formation. In <i>Aliivibrio salmonicida</i> two QS systems the LuxI/R and AinS/R, have been shown to be responsible for the production of eight acyl-homoserine lactones (AHLs) in a cell density dependent manner. We have previously ... -
A new five-wavelength photometer operated in Tromsø (69.6°N, 19.2°E)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-11)A new fve-wavelength photometer was developed and installed at the EISCAT Tromsø site (69.6°N, 19.2°E) in January 2017. The photometer consists of two units: an optical unit and a control unit together with a PC. The photometer is capable of simultaneously observing auroral emissions with fve wavelengths. A uniqueness of the present system is its capability of precise pointing, which enables ... -
Unprecedented Vessel-Icing Climatology based on Spray-Icing Modelling and Reanalysis Data: A Risk-Based Decision-Making Input for Arctic Offshore Industries
(Journal article; Peer reviewed, 2019-04-11)Marine icing is considered a major concern for vessels operating in the Arctic Ocean. Interaction between vessels and waves is the major source of sea spray that, under certain conditions, can lead to ice accretion on the vessels and thus create hazardous situations. Various models have been developed for the estimation of ice accretion rate using meteorological and oceanographic parameters. Various ... -
The dinoflagellate cyst genera Achomosphaera Evitt 1963 and Spiniferites Mantell 1850 in Pliocene to modern sediments: a summary of round table discussions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-14)We present a summary of two round-table discussions held during two subsequent workshops in Montreal (Canada) on 16 April 2014 and Ostend (Belgium) on 8 July 2015. Five species of the genus <i>Achomosphaera</i> Evitt 1963 and 33 of the genus <i>Spiniferites</i> Mantell 1850 emend. Sarjeant 1970 occuring in Pliocene to modern sediments are listed and briefly described along with remarks made by ... -
Emergent Scale Invariance and Climate Sensitivity
(Journal article; Peer reviewed, 2018-11-28)Earth’s global surface temperature shows variability on an extended range of temporal scales and satisfies an emergent scaling symmetry. Recent studies indicate that scale invariance is not only a feature of the observed temperature fluctuations, but an inherent property of the temperature response to radiative forcing, and a principle that links the fast and slow climate responses. It provides a ...
