Institutt for fysikk og teknologi: Nye registreringer
Viser treff 1121-1140 av 1400
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Interpreting sea surface slicks on the basis of the normalized radar cross-section model using RADARSAT-2 copolarization dual-channel SAR images
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-03-24)A simple automatic multipolarization technique for discrimination of main types of thin oil films (of thickness less than the radio wave skin depth) from natural ones is proposed. It is based on a new multipolarization parameter related to the ratio between the damping in the slick of specially normalized resonant and nonresonant signals calculated using the normalized radar cross-section model ... -
Wind resource assessment using mesoscale modelling. A case study at the potential wind farm site Rieppi
(Master thesis; Mastergradsoppgave, 2016-06-01)The growing wind power industry, increased occurrence of extreme weather, and the need for becoming independent of fossil fuels motivate the research on accurate simulation of near-surface wind. The aim of this study is wind resource assessment at the potential wind park site Rieppi, using two on-site measurement masts, simulations from the Weather Research and Forecasting (WRF) model, and ERA-Interim ... -
Numerical computations of turbulent motions in magnetized plasmas
(Master thesis; Mastergradsoppgave, 2016-05-18)Intermittent fluctuations and turbulence-induced transport of magnetically confined fusion plasmas are investigated by numerical computations. A reduced fluid model describing the evolution of plasma pressure and electric drift vorticity in a two-dimensional plane perpendicular to the magnetic field is derived. A numerical simulation code implemented on graphical processing units is presented. We ... -
Sensitivity to pressure and methane of a cryptophane-A doped polymer
(Master thesis; Mastergradsoppgave, 2015-12-15)The principle focus of this thesis is the characterization of an on-chip methane sensor based on a waveguide interferometer. It incorporates cryptophane-A molecules in the waveguide cladding to enhance sensitivity and selectivity towards methane. First, the sensor was characterized for sensitivities to ambient conditions, in particular its temperature and pressure sensitivity. The measurement ... -
Rib waveguides for trapping and transport of particles
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-23)Rib waveguides are investigated as an alternative to strip waveguides for planar trapping and transport of microparticles. Microparticles are successfully propelled along the surface of rib waveguides and trapped in the gap between opposing rib waveguides. The trapping capabilities of waveguide end facets formed by a single and opposing waveguide geometries are investigated. The slab beneath a rib ... -
An evaluation of International Reference Ionosphere electron density in the polar cap and cusp using EISCAT Svalbard radar measurements
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-09-13)Incoherent scatter radar measurements are an important source for studies of ionospheric plasma parameters. In this paper the EISCAT Svalbard radar (ESR) long-term database is used to evaluate the International Reference Ionosphere (IRI) model. The ESR started operations in 1996, and the accumulated database up to 2012 thus covers 16 years, giving an overview of the ionosphere in the polar cap and ... -
Integrated Monitoring of Mola mola Behaviour in Space and Time
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-08-05)Over the last decade, ocean sunfish movements have been monitored worldwide using various satellite tracking methods. This study reports the near-real time monitoring of fine-scale (< 10 m) behaviour of sunfish. The study was conducted in southern Portugal in May 2014 and involved satellite tags and underwater and surface robotic vehicles to measure both the movements and the contextual environment ... -
Retrieval of sodium number density profiles in the mesosphere and lower thermosphere from SCIAMACHY limb emission measurements
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-01-28)An algorithm has been developed for the retrieval of sodium atom (Na) number density on a latitude and altitude grid from SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) limb measurements of the Na resonance fluorescence. The results are obtained between 50 and 150 km altitude and the resulting global seasonal variations of Na are analyzed. The retrieval approach ... -
Time-lapse seismic analysis of focused fluid flow on the Vestnesa Ridge
(Master thesis; Mastergradsoppgave, 2016-06-01)The Vestnesa Ridge is a large sediment drift at water depths of 1200-1300 meter and is the northernmost known gas hydrate province that exists along the Arctic continental margin. Several pockmarks connected to vertical fluid flow features are present at the crest of the Vestnesa Ridge. The fluid flow pierce through the gas hydrate stability zone and interrupt the bottom simulating reflection (BSR) ... -
Depositional environments of the Upper Triassic Snadd Formation on the Loppa High, SW Barents Sea
(Master thesis; Mastergradsoppgave, 2016-06-01)This thesis has focused on the depositional environments of the Upper Triassic Snadd Formation. This formation covers the time-period Ladinian to early Norian with multiple marine regressions and transgressions, resulting in depositional environments ranging from offshore marine shelf to a coastal plain. A 3D seismic dataset and its correlating well have been studied and a refined seismic stratigraphic ... -
Repeatability of P-Cable 3D seismic data
(Master thesis; Mastergradsoppgave, 2016-05-31)The use of 4D time-lapse seismic data is a viable technology for monitoring fluid changes in the subsurface using conventional data, e.g. reservoir exploitation and CO2 storage. In this master thesis, the potential for using high-resolution P-Cable 3D seismic data for 4D time-lapse studies has been evaluated. The P-Cable 3D seismic system is a versatile, lightweight system which employs 24 short ... -
Seabed depressions in the Ingøydjupet Trough and their relation to buried canyons on the Loppa High, Barents Sea
(Master thesis; Mastergradsoppgave, 2016-06-13)Large seabed depressions in the Ingøydjupet Trough have previously been interpreted to be formed by sub-glacial melt-water. However, fluid migration and gas expulsion occur over large parts of the Barents Sea, which are frequently associated with seabed depressions. This thesis studies how the seabed depressions are related to sub-surface canyons on the southern part of the Loppa High, SW Barents ... -
Renewable Energy Resources: A Case Study on Asko Nord AS
(Master thesis; Mastergradsoppgave, 2016-06-01)Asko Nord AS i a business located in Ramfjorden just outside of Tromsø. In this theses, their potential to produce electricity from renewable resources at their location is investigated. Wind around the building is to find suitable locations for wind turbines, and to estimate the wind at the wind turbines. The calculations show that in a feasible estimate the wind is able to produce 439 kwh ... -
Investigation of seafloor craters and mounds in the central Barents Sea
(Master thesis; Mastergradsoppgave, 2016-06-01)Recently acquired datasets of multibeam, echosounder and seismic data reveal the geomorphology and distribution of seafloor craters and mounds in central Barents Sea. The study found 288 craters, 227 pingos and 119 gas flares in the area, each with its own distinctive appearance. The majority of pingos lie inside or close to craters. This indicate a connection between the two features. Inspection ... -
Shallow and Deep Seismic Amplitude Anomalies Indicate Times of Fluid Accumulation and Tectonic Activity in the Barents Sea
(Master thesis; Mastergradsoppgave, 2016-06-01)This master thesis studied the 3D-seismic dataset ST0825 located in the southwest Barents Sea. Aiming to map seismic anomalies and faults above and below the Upper Regional Unconformity (URU). The survey partly covers four different structural elements: Finnmark Platform, Tromsø Finnmark Fault Complex, Hammerfest Basin and Ringvassøy Loppa Fault Complex, south to north respectively. These areas ... -
Possible gas hydrates on the Bjarmeland Platform; seismic expression and stability modelling
(Master thesis; Mastergradsoppgave, 2016-05-24)Seismic evidence of shallow gas anomalies are prominent at Ververis Dome structure and Hoop Fault Complex in Bjarmeland Platform. Ubiquitous high amplitude anomalies at the same depth as these shallow gas anomalies infer a possible relation to gas hydrates. A wide range of fluid flow structures within the two study areas have previously been discovered and reported, and may possibly feed the base ... -
Seafloor craters and mounds in the central Barents Sea
(Master thesis; Mastergradsoppgave, 2016-05-31)Multiple giant craters and mounds have been identified in the area of the Upper Bjørnøyrenna in the central Barents Sea from the reflection seismic and echo sounder data. Analysis of seismic and echo sounder data revealed clear connection between these distinct seafloor features and seismic amplitude anomalies. Distribution pattern of the numerous water column anomalies registered in the area and ... -
Fluid flow features and gas hydrates in the outer Vøring Basin
(Master thesis; Mastergradsoppgave, 2015-12-15)The 3D seismic survey ST0827 in the outer Vøring Basin reveals a complex fluid flow system consisting of hydrothermal vents, polygonal faults and acoustic pipes. The polygonal faults are bound to the fine-grained Top Brygge Formation and ooze-dominated Kai Formation. The Kai Formation is overlain by the Naust Formation, in which glacigenic debris flow units are observed. As polygonal faults can be ... -
Late summer sea ice segmentation with multi-polarisation SAR features in C- and X-band
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-01)In this study we investigate the potential of sea ice segmentation by C- and X-band multi-polarisation synthetic aperture radar (SAR) features during late summer. Five high-resolution satellite SAR scenes were recorded in the Fram Strait covering iceberg- fast first-year and old sea ice during a week with air temperatures varying around zero degrees Celsius. In situ data consisting of sea ice ... -
Sensitive on-chip methane detection with a cryptophane-A cladded Mach-Zehnder interferometer
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-24)We report a methane sensor based on an integrated Mach-Zehnder interferometer, which is cladded by a styrene-acrylonitrile film incorporating cryptophane-A. Cryptophane-A is a supramolecular compound able to selectively trap methane, and its presence in the cladding leads to a 17-fold sensitivity enhancement. Our approach, based on 3 cm-long low-loss Si3N4 rib waveguides, results in a detection limit ...