Viser treff 1-10 av 157
Bonding in low-coordinate complexes : what, if anything, is special?
(Doctoral thesis; Doktorgradsavhandling, 2008-10-14)
To contribute to the fundamental picture of the electronic structure of low-coordinate transition metal complexes, we have carried out a series of DFT studies on mono-imido and nitrosyl complexes for different metal ions (Mn<sup>II/III</sup>, Fe<sup>II/III/IV</sup>, Co<sup>II/III</sup>) and different systems of basal ligands. These studies reveal striking similarities of the electronic structure ...
Water and heat transfer in cement based materials
(Doctoral thesis; Doktorgradsavhandling, 2011-06-17)
For the mass transfer case (the absorption of moisture-water into concrete), the water content in concrete has a significant impact on its mechanical properties. Moisture transport in porous media, for example, plays an important role in the degradation of building materials such as mortars and concrete. LWE ignores the complex pore structure and network, typically found in cement materials. Many ...
Interferometric and high time-resolution observations of naturally enhanced ion-acoustic echoes at the EISCAT Svalbard radar: Software radar and incoherent scattering
(Doctoral thesis; Doktorgradsavhandling, 2003-06-24)
We know that the visible Aurora Borealis is structured on many different scales, down to a few tens of metres. By using the EISCAT radars on Svalbard as an interferometer, we have found structures in the radio echoes from the auroral ionosphere on a scale approaching that of the visible aurora, and simultaneously with it, but at far greater ranges. In this thesis we discuss how these radar observations ...
Wave damping and momentum transfer. Manifestation of momentum transfer in case of ocean surface waves being damped by an elastic film or a viscous layer
(Doctoral thesis; Doktorgradsavhandling, 2001-02-28)
Virkninga av å ha et bølgedempende overflatemateriale i ei havoverflate er studert, med særlig vekt på betydninga av strålingstrykket (-stresset) eller bølgetrykket fra et innfallende, udempet bølgefelt. Det er et teoretisk studium av den dynamiske prosess som foregår når udempede overflatebølger propagerer inn i et område med bølgedempende overflatesjikt, i lys av det bølgetrykk bølgene øver på ...
Behavioral and energetic response of Arctic-breeding seabirds to environmental variability.
(Doctoral thesis; Doktorgradsavhandling, 2009-06-16)
Knowledge about the extent to which organisms inhabitating the Arctic are able to adjust to environmental variability is essential in order to predict the impact of future climate change. In this context, the flexibility og two Acrtic-breeding seabirds, the little Auk (Alle alle) and the kittiwake (Rissa tridactyla), in foraging behavior and energy expenditure in response to environmental variability. ...
Spatial and temporal analysis of fluid venting systems on the Norvegian-Svalbard margin
(Doctoral thesis; Doktorgradsavhandling, 2009-04-03)
Seafloor depth estimation by means of interferometric synthetic aperture sonar
(Doctoral thesis; Doktorgradsavhandling, 2010-11-19)
The topic of this thesis is relative depth estimation using interferometric sidelooking sonar. We give a thorough description of the geometry of interferometric sonar and of time delay estimation techniques. We present a novel solution for the depth estimate using sidelooking sonar, and review the cross-correlation function, the cross-uncertainty function and the phase-differencing technique. We ...
Benthic foraminifera as indicators of natural variability and anthropogenic impact
(Doctoral thesis; Doktorgradsavhandling, 2013-11-28)
Benthic foraminifera (micro-organism living on the sea-floor) were studied in the southwestern Barents Sea and Hammerfest harbor. The study focused on the response of the micro-organisms to natural and man made environmental changes. The study shows that the southwestern Barents sea is relatively clean, and the foraminifera are only impacted by natural changes. However, in the Hammerfest harbor, ...
Recursive calculation of high-order molecular response properties
(Doctoral thesis; Doktorgradsavhandling, 2013-12-06)
This thesis presents the implementation and application of a computer program for the open-ended calculation of response properties of molecular systems. Using recursive programming techniques, a recently published formulation of response theory can be implemented in a manner that allows the calculation of response properties to arbitrary order. The limitations of the code are dictated by the ...
Statistical methods for scale-invariant and multifractal stochastic processes.
(Doctoral thesis; Doktorgradsavhandling, 2014-10-03)
This thesis focuses on stochastic modeling, and statistical methods, in finance and in climate science. Two financial markets, short-term interest rates and electricity prices, are analyzed. We find that the evidence of mean reversion in short-term interest rates is week, while the “log-returns” of electricity prices have significant anti-correlations. More importantly, empirical analyses confirm ...