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norskFakultet for naturvitenskap og teknologi: Recent submissions
Now showing items 3861-3880 of 5327
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Diagnostics of Ion Beam and Current Free Double Layer in Helicon Plasma Devices with Expanding Magnetic Field
(Doctoral thesis; Doktorgradsavhandling, 2017-09-18)The main focus of this thesis is the diagnostics of ion beams in helicon plasma devices with expanding magnetic field, and running in an inductive mode. These ion beams are closely connected to the concept of current-free double layers (CFDL). We started by investigating how to best interpret the measurements from a Retarding Field Energy Analyzer (RFEA) through 3-dimensional particle-in-cell ... -
Marine radar properties, analysis and applications
(Master thesis; Mastergradsoppgave, 2017-08-01)In this thesis marine radars are compared with synthetic aperture radars (SAR) and the possibility of cross-over applications are investigated. A first cross-over has been demonstrated by using the TS-CFAR on marine radar images. The TS-CFAR was originally developed for SAR and is a constant false alarm rate (CFAR) detection algorithm based on truncated statistics. Detecting weak targets embedded ... -
Case study of a large-scale solar, wind and hydro power hybrid system in Skibotndalen, Troms
(Master thesis; Mastergradsoppgave, 2017-06-06)The power company Troms Kraft is interested in the feasibility of a large-scale hybrid system in Skibotndalen in Troms. There are two existing hydro power stations in the area, and this thesis concerns the addition of an electric solar power plant of 20 MW and a wind power plant of 21 MW to these stations. As measured solar radiation is not available for one whole year at the location, solarradiation ... -
3-D seismic interpretation of the Samson Dome in the framework of the tectonostratigraphic and fluid migration development of the Western Barents Sea
(Master thesis; Mastergradsoppgave, 2017-06-21)Three-dimensional (3-D) seismic interpretations of data from the Samson Dome show direct connection between the local geological evolution of the area and the regional tectonic and stratigraphic development of the western Barents Sea. Rifting events, halokinetic movements, uplift and glacial processes influenced the area of the Samson Dome. The Samson Dome structure, located in the south-western ... -
The link between fluid flow and glacial erosion along the Ringvassøy- Loppa fault complex, Tromsøflaket, SW Barents Sea
(Master thesis; Mastergradsoppgave, 2017-06-06)This master thesis has focused its efforts to investigate the link between glacial erosion and focused fluid flow in the SW Barents Sea, on the shallow bank area of Tromsøflaket where the Ringvassøy-Loppa Fault Complex borders the Tromsø basin in west, and the Loppa High in east. Here, large, elongated depressions are identified on the buried Upper Regional Unconformity (URU) and may resemble tunnel ... -
Case study of a large-scale solar and wind power hybrid system at Fakken Wind Farm, Troms
(Master thesis; Mastergradsoppgave, 2017-06-01)The objective of this thesis is to investigate the feasibility of a large scale hybrid system at Fakken, Troms. There is already an existing 54 MW wind farm at site. The wind farm has considerably higher power production during winter compared to summer, and the electricity grid is therefore not fully exploited during summer. Adding a solar panel utility to the site could be a solution to this issue. ... -
Changes in paleoceanography and methane release in relation to past climatic variability at Vestnesa Ridge, Svalbard
(Master thesis; Mastergradsoppgave, 2017-06-01)Sediment core HH16-549GC from Vestnesa Ridge in the Fram Strait, western Svalbard, has been investigated in order to reconstruct paleoceanographic and paleoclimatic conditions from 31,000 to 7500 cal years BP. Vestnesa Ridge is located in an area with extensive seepage of methane from the ocean floor. The core is retrieved from within a pockmark to reconstruct possible changes in seepage of methane ... -
Optimization of wind turbine location in urban environment
(Master thesis; Mastergradsoppgave, 2017-06-01)Making energy clean, reliable and readily available is essential for fighting climate change and to supply an ever-rising global power demand. The aim of the study is to identify optimal locations for a wind turbine to be joined to a small-scale hybrid system at the main campus of UiT – The Arctic University of Norway. To identify feasible areas for maximizing electric power production, techniques ... -
Modelling the future of the arctic sea ice cover
(Master thesis; Mastergradsoppgave, 2017-06-01)Record lows in sea ice cover have recently sparked new interest in the small ice cap instability. The change in albedo when sea ice becomes open water introduces a nonlinearity called the ice-albedo feedback. Forcing a joint energy- balance and sea ice model can lead to unstable ice caps in certain parameter regimes. When the ice caps are unstable, a small perturbation will initiate a tipping point ... -
Detailed mapping of faults and fractures along Vestnesa ridge
(Master thesis; Mastergradsoppgave, 2017-05-31)This master thesis is focused on studying the Vestnesa Ridge located west of Svalbard. The Vestnesa Ridge is a 100 km long and about 3 km wide sediment drift located on the recently uplifted Svalbard margin. The crest of the ridge is represented with numerous pockmarks with different size, orientation and elongation. High resolution seismic data connected pockmarks with acoustic chimneys and faults ... -
Fluid flow at the Snøhvit field, SW Barents Sea: processes, driving mechanisms and multi-phase modelling
(Doctoral thesis; Doktorgradsavhandling, 2017-07-03)The research undertaken in this PhD project was part of a large EU interdisciplinary project named ECO2: Sub-seabed CO2 Storage: Impact on Marine Ecosystems. The overall goal of the ECO2 project was to understand the short-term and long-term impacts of CO2 storage on marine ecosystems. I concentrated my work on the Snøhvit site, which is located in the SW Barents Sea, on the Norwegian continental ... -
Elemental carbon measurements in European Arctic snow packs
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013-12-26)Black carbon (BC) and other light-absorbing particles deposited on snow and ice are known to perturb the surface radiative balance. There are few published observations of the concentration of these particles in the snow in Scandinavia and the European Arctic. We measured BC concentrations in snow samples collected in this region from 2007 to 2009, and we present the results here. The data set ... -
Petroleum systems of the Barents shelf. A regional well-based study of the mesozoic
(Master thesis; Mastergradsoppgave, 2017-06-30)The entire Barents Sea area has experienced a complex geological evolution. From orogenic processes connected to Caledonian mountain building in Palaeozoic to basin formation related to the opening of the Atlantic Ocean in Paleogene. Uplift and erosion processes (Exhumation) that fined place in Ceinozoic contribute to erosion and redepositing of thick sedimentary sequences over Barents Sea ... -
Modeling probability density functions of non-negative random variables using novel series expansions based on mellin kind statistics
(Master thesis; Mastergradsoppgave, 2017-05-31)Mellin kind (MK) statistics is the framework which arises if the Fourier transform is replaced with the Mellin transform when computing the characteristic function from the probability density function. We may then proceed to retrieve logarithmic moments and cumulants, which have important applications in the analysis of heavy-tailed distribution models for non-negative random variables. In this ... -
The OXA-class of β-lactamases. A structural view on antibiotic resistance
(Doctoral thesis; Doktorgradsavhandling, 2017-09-01)Antibiotic resistance is a topic that concerns everyone, and by 2050 deaths due to antibiotic resistant bacteria may surpass number of deaths due to cancer. The OXA-class of antibiotic resistance enzymes is a formidable threat, but has not received the same attention as other resistance enzymes. The goal of the project was to understand antibiotic resistance enzymes at an atomic scale and to develop ... -
Some giant submarine landslides do not produce large tsunamis
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-08-07)Landslides are the second-most important cause of tsunamis after earthquakes, and their potential for generating large tsunamis depend on the slide process. Among the world's largest submarine landslides is the Storegga Slide that generated an ocean-wide catastrophic tsunami, while no traces of a tsunami generated from the similar and nearby Trænadjupet Slide have been found. Previous models for ... -
Dynamic self-organisation of haematopoiesis and (a)symmetric cell division
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-12-05)A model of haematopoiesis that links self-organisation with symmetric and asymmetric cell division is presented in this paper. It is assumed that all cell divisions are completely random events, and that the daughter cells resulting from symmetric and asymmetric stem cell divisions are, in general, phenotypically identical, and still, the haematopoietic system has the flexibility to self-renew, ... -
On the contribution of thermal excitation to the total 630.0 nm emissions in the northern cusp ionosphere
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-01-25)Direct impact excitation by precipitating electrons is believed to be the main source of 630.0 nm emissions in the cusp ionosphere. However, this paper investigates a different source, 630.0 emissions caused by thermally excited atomic oxygen O(1D) when high electron temperature prevail in the cusp. On 22 January 2012 and 14 January 2013, the European Incoherent Scatter Scientific Association (EISCAT) ... -
Measurements of ionic liquids thermal conductivity and thermal diffusivity
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11-02)Thermal conductivity and thermal diffusivity of ionic liquids (ILs) are investigated in this work. A hot disk method for ILs thermal conductivity and thermal diffusivity measurement is utilized. Firstly, the thermal conductivity of water is measured to check the reliability of the hot disk method. In addition, the thermal conductivity of pure ILs, including BmimBF<sub>4</sub>, BmimPF<sub>6</sub>, ... -
Reconstructing the holocene. Benthic foraminifera as a proxy for the paleoceonography of the nordic seas
(Master thesis; Mastergradsoppgave, 2017-08-01)The benthic foraminifera of two marine sediment cores were studied as a proxy for paleoenvironment reconstructions throughout the Late to Early Holocene. The two cores were sampled in different localities to allow a spatial comparison of changing environments in the Nordic Seas and sampled for benthic foraminiferal assemblages, grain size, IRD, sortable silts and benthic foraminifera isotopes. While ...
