In this thesis, clean and oxidized Pd(57)Cu(43)(100) single crystal surfaces were studied by LEED, STM and XPS in UHV conditions. The clean sample annealed to 300 degrees C has been found to either consist of ordered domains of Pd or Cu atoms forming a c(2 × 2) structure, or by a more disordered alloy c(2 × 2) structure of p4g symmetry. Small areas of (1 × 1) structure as well as screw dislocations and island- like formations are present on this surface. Annealing the clean sample to 600 degrees C causes Cu segregation to the surface as well as a shift towards higher binding energy of Pd 3d(5/2) core levels, and an almost defect- free surface with p(2 × 2) structure is seen. Oxidation at 300 degrees C of the surface annealed to 300 degrees C shows that a c(2 × 2) covers the whole surface for all oxygen dosages at 68L or above, and XPS spectra do not vary with oxygen dosage, hence the c(2 × 2) is inert in this case. For dosages of 1350L or above, oxide islands and a large number of defects could appear, depending on the preparation history of the sample. Oxidation at 300 degrees C and 600 degrees C of the Cu rich surface annealed to 600 degrees C reveals up to seven structures, which are p(2 × 2), c(2 × 2), (4 × 4)- like, hexagonal, maze- like, (2root(2) ×root(2))R45degrees missing row type and one more structure that could not be characterized. There is evidence that copper oxide phases are formed for the Cu rich surfaces annealed to 600 degrees C, but no bulk oxide was formed in any experiments. A detailed understanding of clean and oxidized Pd(57)Cu(43)(100) has been obtained at the atomic scale.

Using a simulation based model, with the Black-Scholes framework for equity andThe LIBOR Market Model for interest rates, we study market risk in multi assetclassportfolios, with static and dynamic weighting. The risk measures consideredare Value-at-Risk and Expected-Tail-Loss. The theoretical foundation is introducedand imperfections in the models and their assumptions are pointed out.The validity of the models and risk measures is tested using a backtesting procedureagainst data ranging from September 1999 to September 2009, with particularemphasis on the turbulent period of 2007 to September 2009. The results indicatethat the models perform slightly worse on the portfolio with the added complexityof a dynamic weighting regime. No evidence of the models performing lesssatisfactory under the latest financial turbulence is found.

Vanntrevekst er den viktigste årsaken til aldring i polymerisk isolasjon i mellomspenningskabler. Sia vanntrær ikke dannes ved lav relativ fuktighet (R.H.), er det viktig å holde relativ fuktighet i isolasjonen lav så lenge som mulig. Dette kan gjøres ved å beskytte isolasjonen med ei kappe av to polymerer. For å beregne vanntransporten inn i isolasjonen, må kappematerialenes vanntransportegenskaper kjennes. For noen polymerer varierer vanntransportegenskapene med det hydrostatiske trykket og den relative fuktigheta (damptrykket). I denne oppgaven er det målt transportkoeffisienter for to kandidater til kappematerialer: én halvledende lineær lavdensitetspolyetylen (LLDPE) og én halvledende eterbasert termoplastisk polyuretan (TPU). Noen av prøvene har vært utsatt for strekking til 10 % statisk forlengelse og etterfølgende relaksasjon i forkant av forsøkene, for å finne ut om ei slik mekanisk påkjenning har noe å si for transportkoeffisientene. Det er gjort målinger av metningskonsentrasjoner ved 0,1 MPa og 30 MPa hydrostatisk trykk, og permeabilitetsmålinger ved forskjellige damptrykk. Konklusjonene om metningskonsentrasjonen i TPU ved 0,1 MPa og 30 MPa hydrostatisk trykk trekkes delvis på grunnlag av et tidligere arbeid. I tillegg har diffusjons- og løselighetskoeffisientene for ustrukket TPU blitt målt ved forskjellige damptrykk. Det er ikke funnet noen signifikant sammenheng mellom det hydrostatiske trykket og vannopptaket i noen av materialene, hverken med strukkede eller ustrukkede prøver. Det er heller ikke funnet at strekking har noen signifikant innvirkning på transportkoeffisientene, bortsett fra at strukket TPU viser en ca. 15 % større metningskonsentrasjon enn ustrukket TPU. Det er funnet at transportkoeffisientene i TPU varierer med damptrykket, men hverken diffusjons-, løselighets- eller permeabilitetskoeffisienten varierer mer enn med en faktor 3 mellom 20 % R.H. og 80 % R.H. For LLDPE er det ikke gjort like omfattende undersøkelser, men permeabilitetskoeffisienten i det materialet viser ingen damptrykkavhengighet.

This thesis introduce a new parameterization of the model space in global inversion problems. The parameterization provides an explicit representation of the model space with a basis constrained on a priori information about the problem at hand. It is able to represent complex model structures with few parameters, and thereby enhancing the speed of the inversion, as the number of iterations needed to converge is heavily scaled with the number of parameters in stochastic, global inversion methods. A standard Simulated Annealing optimization routine is implemented, and further extended to be able to optimize for a dynamically varying number of variables. The method is applied on inversion of marine CSEM data, and inverts both synthetic and real data sets and is able to recover resistivity profiles that demonstrate good resemblance with provided well bore log data. The trans-dimensional, self-parameterizing Simulated Annealing algorithm which is introduced in this thesis proves to be superior to the regular algorithm with fixed parameter dimensions.

We have performed modified Gurson model calibrations to the steel alloys Weldox 460E, Weldox 700E and Weldox 900E through finite element method (FEM) simulations of various tensile material tests performed, and used these material models to perform FEM simulations of impact of blunt tool steel projectiles on target plates made out of these steel alloys. The purpose of these FEM simulations was to study the dependence of target plate steel alloy on the ballistic limit velocity of the projectile resulting from the modified Gurson model. It was found that the modified Gurson model is able to reproduce the dependence seen in experiments, but that it is strongly dependent on a certain model parameter related to the shear stress dependence on material damage. We have also discovered potential problems, and possible solutions, regarding the calibration of these material models and the use of them in the FEM impact simulations carried out.