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norskFakultet for naturvitenskap og teknologi
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Thermography and tensile tests of steel samples. Study of material properties and internal friction effects
(Master thesis; Mastergradsoppgave, 2018-06-01)The thesis presents analysis of material properties and internal effects in steel samples, with varying temperatures. Uniaxial tensile tests were conducted in both room temperature and low temperatures, to generate graphical measures of the mechanical properties. The steel samples were monitored with thermography throughout the course of the tensile tests, to investigate the heat generation associated ... -
Friction tests on polyurethane and concrete. Rolling friction tests and sliding friction tests on anti-abrasion polyurethane, anti-seepage polyurethane and concrete.
(Master thesis; Mastergradsoppgave, 2018-06-01)The climate in arctic areas of the world is a challenge for airports. Snow and ice accumulates on the runways, forcing airports to close for snow clearing. Pilots need to know that the friction is at a respectable level before they land, and may have to return if not. This thesis looked at a polymer called polyurethane, and if this material could be used as a new runway material, considering both ... -
Oil Spill Preparedness and Response in the Arctic. The effect of low temperature on oil spill response operations in the Arctic with respect to overall equipment effectiveness
(Master thesis; Mastergradsoppgave, 2018-06-02)Effectiveness is an important term in oil spill response operations. Literature often relate to the level of effectiveness connected to either mechanical containment and recovery, in-situ burning or chemical dispersant application. The term effectiveness in oil spill response operations can be related to existing theory and the perspective of Overall Equipment Effectiveness (OEE). The perspective ... -
Icing Effects on Power Lines and Anti-icing and De-icing Methods
(Master thesis; Mastergradsoppgave, 2018-05-30)Icing on power lines may lead to compromise safety and reliability of electric supply network. Prolong icing can lead to power breakdown and collapse of towers. Since power transmission lines are mostly overhead and could face the direct impact of icing, and it is one of the main challenges faced by power distribution companies in cold regions. When the ice accretion crosses the safety limit then ... -
Navigation in the Arctic. How can simulator training be used for assessment and reduction of risk?
(Master thesis; Mastergradsoppgave, 2018-06-01)Over the recent years, the ship traffic in the polar areas has increased. There is reason to believe that this traffic, and especially the cruise traffic, will increase further as the ice retracts towards the poles. There is also reason to believe that with the continued focus and exposure of the Polar Region, the cruise tourism to the region will grow.The increased presence in the polar areas will ... -
Late Cenozoic erosion estimates for the northern Barents Sea: Quantifying glacial sediment input to the Arctic Ocean
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-14)A compilation of seismic data has been used to characterize the Neogene – Quaternary sedimentary succession of the northwestern Barents Sea continental margin to better understand the paleoenvironmental evolution and the sedimentary processes involved. The Neogene strata are dominated by contourites related to the ocean circulation established from the opening of the Fram Strait connecting the ... -
An unsupervised method for equivalent number of looks estimation in complex SAR scenes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-12)This paper introduces a novel unsupervised estimator of equivalent number of looks (ENL) that can be applied to an arbitrary image. It avoids the assumption that homogeneous speckle will dominate the investigated image that is followed by current unsupervised ENL estimators but not always valid, especially for the complex SAR scenes with high mixture and texture. Incorporating the statistical ... -
Aspects of model-based decompositions in radar polarimetry
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-12)In this paper, we further analyse the problem that polarimetric target decomposition methods in general have more physical parameters than equations, making the decomposition under-determined and hence have no unique solution. The common approach to get around this problem is to make certain assumptions, thus fixing one or more parameters, allowing the other free parameters to be solved from the set ... -
Incorporating Incidence Angle Variation into Sar Image Segmentation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018)We present a new approach for incorporating incidence angle derived synthetic aperture radar (SAR) brightness variation directly into SAR image analysis. This approach is unique in that the incidence angle dependency is modeled explicitly into the probability density function rather than an image-wide pre-processing ‘correction’. It can then be used for supervised and unsupervised image analysis, ... -
Particle sources and downward fluxes in the eastern Fram strait under the influence of the west Spitsbergen current
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06-10)<p>The carbon cycle of the Arctic Ocean is tightly regulated by land–atmosphere–cryosphere–ocean interactions. Characterizing these environmental exchanges and feedbacks is critical to facilitate projections of the carbon cycle under changing climate conditions. The environmental drivers of sinking particles including organic carbon (OC) to the deep-sea floor are investigated with four moorings ... -
The Lower Cretaceous succession of the northwestern Barents Shelf: Onshore and offshore correlations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-24)The Lower Cretaceous succession in the Barents Sea is listed as a potential play model by the Norwegian Petroleum Directorate. Reservoirs may occur in deep to shallow marine clastic wedges located in proximity to palaeo-highs and along basin margins. In addition, shelf-prism-scale clinoforms with high amplitude anomalies in their top- and bottomsets have been reported from reflection seismic but ... -
Unsupervised Mixture-Eliminating Estimation of Equivalent Number of Looks for PolSAR Data
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-08-22)This paper addresses the impact of mixtures between classes on equivalent number of looks (ENL) estimation. We propose an unsupervised ENL estimator for polarimetric synthetic aperture radar (PolSAR) data, which is based on small sample estimates but incorporates a mixture-eliminating (ME) procedure to automatically assess the uniformity of the estimation windows. A statistical feature derived from ... -
The emergence of modern sea ice cover in the Arctic Ocean
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-11-28)Arctic sea ice coverage is shrinking in response to global climate change and summer ice-free conditions in the Arctic Ocean are predicted by the end of the century. The validity of this prediction could potentially be tested through the reconstruction of the climate of the Pliocene epoch (5.33–2.58 million years ago), an analogue of a future warmer Earth. Here we show that, in the Eurasian sector ... -
Pellets på avveie. Fra vugge til hav
(Master thesis; Mastergradsoppgave, 2018-08-03)Denne masteroppgaven ser nærmere på hvordan plastikkindustrien i Norge er organisert, og hvordan to aktører innen næringen praktiserer HMS for å redusere og forebygge utslipp av råstoff til plastproduksjons. Oppgaven er gjennomført som en casestudie med utgangspunkt i et samtidsaktuelt problem- plastforurensning med følgende problemstilling: Hvordan ivaretas helse miljø og sikkerhet (HMS) i ... -
Blir kommunenes beredskap for miljø- og kjemikaliehendelser bedre ved innføring av nye krav? En studie av hvordan kommuner integrerer nye krav i forskrift for miljørettet helsevern inn i eksisterende beredskapsarbeid
(Master thesis; Mastergradsoppgave, 2018-07-12)Samfunnet vårt i dag er avhengig av en rekke kjemikalier i industri og næringsliv (Justis- og beredskapsdepartementet, Helse- og omsorgsdepartementet & Forsvarsdepartementet, 2016). Vest-tank ulykken i 2007 i Gulen kommune, hvor en tank på et industrianlegg eksploderte. Anlegget skulle rense forurenset vann fra lasteskip. Det kom frem etter ulykken at Vest-tank også drev med ulovlig håndtering av ... -
Bayesian analysis of temporal and spatial trends of house prices in Norway
(Master thesis; Mastergradsoppgave, 2018-09-21)The goal of this thesis is to analyse the temporal and spatial trends of house prices in Norway in a Bayesian setting. We will perform regression analysis of the data which will be modelled using structured additive regression models. This choice was made because structured additive regression models can be put into a computational framework of latent Gaussian models that can be analysed using ... -
Mathematics of Viral Infections: A Review of Modeling Approaches and A Case-Study for Dengue Dynamics
(Master thesis; Mastergradsoppgave, 2018-09-20)In this thesis we use mathematical models to study the mechanisms by which diseases spread. Transmission dynamics is modelled by the class of SIR models, where the abbreviation stands for susceptible (S), infected (I) and recovered (R). These models are also called compartmental models, and they serve as the basic mathematical framework for understanding the complex dynamics of infectious diseases. ... -
Distribution, deposition and impact of tailing disposal on the seafloor in Ranfjorden, northern Norway
(Master thesis; Mastergradsoppgave, 2018-07-29)This study is conducted in Ranfjorden in northern Norway with the goal of gaining a better understanding of the interaction between natural and anthropologic sediments within the fjord. Ranfjorden is of interest due to the fact that it has experienced extensive anthropologic impacts over the last 100 years with the submarine tailings placement (STP) of mine tailings ongoing. The analysis of this ... -
Redox-dependent niche differentiation provides evidence for multiple bacterial sources of glycerol tetraether lipids in lakes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-10-23)Terrestrial paleoclimate archives such as lake sediments are essential for our understanding of the continental climate system and for the modeling of future climate scenarios. However, quantitative proxies for the determination of paleotemperatures are sparse. The relative abundances of certain bacterial lipids, i.e., branched glycerol dialkyl glycerol tetraethers (brGDGTs), respond to changes in ... -
Rock glaciers in central Patagonia
(Journal article; Tidsskriftartikkel; Peer reviewed, 2018-10-22)Active rock glaciers are ice and debris-cored landforms common in cold arid mountains. They have not been widely described in the Patagonian Andes of southern South America and here we provide the first rock glacier inventory for the Jeinimeni region to the east of the contemporary North Patagonian Icefield. Detailed analysis of available satellite imagery and fieldwork demonstrates the presence of ...
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