Institutt for fysikk og teknologi: Recent submissions
Now showing items 1181-1200 of 1409
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RAM analysis of mining equipment and framework for data collection
(Master thesis; Mastergradsoppgave, 2015-06-01)In the mining industry, equipment are continuously increasing in size and complexity. At the same time, the demand for available plants and continuous production has never been higher. The performance of equipment depends on the reliability and maintainability performance of the equipment along with the maintenance supportability, operational conditions, and environmental conditions. In order to ... -
A detailed investigation of a geological CO2-storage reservoir
(Master thesis; Mastergradsoppgave, 2015-05-31)Increased CO2-concentrations within the atmosphere of the Earth have encouraged development of “carbon capture and storage” (CCS). It is important to avoid global warming, and CO2 may be stored within geological formations in the subsurface. This thesis focuses on the possibilities of storing CO2 in a reservoir of Middle Triassic-Middle Jurassic age in The Nordkapp Basin, The Southern Barents ... -
Evaluation of probability of failure of static equipment in pressurized mud systems on an offshore drilling installation
(Master thesis; Mastergradsoppgave, 2015-06-01)Degradation of pressurized topside static mud equipment is a very complex process. Inspection is a helpful tool to monitor degradation and helps reduce the number of critical failures. If it is left undetected and unchecked, it can lead to leakage resulting in accidents. To set up an effective inspection program, the concepts of Risk-Based Inspection (RBI) can be utilized. RBI helps to develop an ... -
A study of the potential improvement of Sydvaranger Gruve´s process water treatment through experiments with different flocculants and coagulants
(Master thesis; Mastergradsoppgave, 2015-06-01)Mining is the process or industry of extracting valuable minerals or other geological materials from the earth. The nature of mining creates a potential negative impact on the environment both during the mining operations and several years after the mine is closed. Over the years regulations designed to moderate the negative effects are adopted, and environmental issues and challenges have ... -
QRA techniques on dynamic positioning systems during drilling operations in the Arctic: With emphasis on the dynamic positioning operator
(Master thesis; Mastergradsoppgave, 2015-06-01)With the Norwegian government moving the ice edge farther north than ever before, opening for new areas for petroleum exploration, it will need research on how these areas can affect oil and gas operations. A sensitive environment along with the harsh Arctic climate and remote distances means that severe accidents, like blowouts, will have serious impacts and make cleanup and rescue actions to ... -
Risk analysis of well control operations considering Arctic environmental conditions
(Master thesis; Mastergradsoppgave, 2015-06-01)Oil and gas development in the Arctic is becoming a major focus in the industry today. However, compared to other regions, there is less experience regarding drilling operations in the Arctic environment. This fact raises concerns about high-risk scenarios, which might take place because of the harsh environmental conditions and the effects they have on various phases of operations, equipment and ... -
Fast estimation of ocean background reflectivity in synthetic aperture radar images
(Master thesis; Mastergradsoppgave, 2015-06-02)Several ship detection algorithms have been developed over the years, where some of the most commonly used are the constant false alarm rate (CFAR) algorithms. There are challenges to the existing algorithms, both when it comes to processing time and difficult scene situations, such as heterogeneous ocean clutter and multiple targets. Existing algorithms that are equipped to handle situations ... -
Ship detection products based on complex SAR data in TOPS mode
(Master thesis; Mastergradsoppgave, 2015-06-01)With the increasing need for monitoring ship traffic in both coastal and open oceans, ship detection is an important application of synthetic aperture radar (SAR). This thesis investigates image products suitable for ship detection for complex data acquired in Terrain Observation by Progressive Scans (TOPS) mode. The research was based on studying how contrast enhancement algorithms suitable for SLC ... -
Multi-radar observations of polar mesosphere summer echoes during the PHOCUS campaign on 20-22 July 2011
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-06-27)During the PHOCUS rocket campaign, on 20-22 July 2011, the observations of polar mesosphere summer echoes (PMSE) were made by three mesosphere-stratosphere-troposphere radars, operating at about 50 MHz. One radar, ESRAD is located at Esrange in Sweden, where the rocket was launched, two other radars, MAARSY and MORRO, are located 250 km north-west and 200 km north of ESRAD, respectively, on the other ... -
The nature of the gas-hydrate/free gas transition zone at the base of the hydrate-stability zone from high-resolution 3D seismic data
(Master thesis; Mastergradsoppgave, 2015-01-26)Geophysical evidence of a prominent BSR at Vestnesa Ridge and north to the northern flank of the Storegga slide escarpment infer that gas hydrates are ubiquitous within these regions. A wide range of fluid flow structures have previously been discovered from these regions, as well as gas seepage activity from pockmarks on the eastern segment of Vestnesa Ridge. This paper focuses on high-resolution ... -
Magnitude of extreme heat waves in present climate and their projection in a warming world
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014)An extreme heat wave occurred in Russia in the summer of 2010. It had serious impacts on humans and natural ecosystems, it was the strongest recorded globally in recent decades and exceeded in amplitude and spatial extent the previous hottest European summer in 2003. Earlier studies have not succeeded in comparing the magnitude of heat waves across continents and in time. This study introduces a new ... -
Corrigendum to "Development of the mesospheric Na layer at 69 degrees N during the Geminids meteor shower 2010", published in Ann.Geophys., 31, 61-73, 2013
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015) -
Monitoring glacier changes using multitemporal multipolarization SAR images
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014) -
Simulation of Anti-reflection Coated Carbonaceous Spectrally Selective Absorbers
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-11-22) -
20 years of research on the Alcator C-Mod tokamak
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014) -
Velocity scaling for filament motion in scrape-off layer plasmas
(Journal article; Tidsskriftartikkel; Peer reviewed, 2011) -
Effect of dynamical friction on interchange motion of plasma filaments
(Journal article; Tidsskriftartikkel; Peer reviewed, 2012) -
Convergence of statistical moments of particle density time series in scrape-off layer plasmas
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015) -
Blob sizes and velocities in the Alcator C-Mod scrape-off layer
(Journal article; Tidsskriftartikkel; Peer reviewed, 2013)Gas-puff imaging data is used to investigate the dynamics of blob-like structures in the scrape-off layer of Alcator C-Mod. A blob-tracking algorithm is developed and used to compute blob propagation velocities and cross-field sizes for a series of discharges where the line-averaged particle density View the MathML source is varied. We find that the mean radial blob velocity increases from View the ... -
Estimation of statistical moments for single point measurements in the Scrape Off Layer
(Conference object; Konferansebidrag, 2014-03-17)