Analyser av okkultasjonskurvene frå fotoelektriske observasjonar viser at ein stor del av dei observerte stjernene er dobbelstjerner. Okkultasjonsteknikken kan lett åtskilje stjerner som har ein vinkelavstand større enn 0",01 og under gunstige tilhøve kan oppløysinga vere 0",001. I tillegg kan analysen av observasjonen gje vinkeldiameteren til stjerna dersom han er større enn 0",001. Utfrå ...

In this thesis we study the second-order statistical moment functions that characterizes complex-valued harmonizable processes. A real-valued harmonizable process has four Hermitian second-order functions. These functions are equivalent representations of the second-order statistical quantities of the process. For a complex-valued harmonizable process, however, we need the complementary functions ...

Approximately 800 women die from pregnancy or childbirth-related pregnancy complications around the world every day. One of the major reasons for these complications is inflammation following infection. Approximately 40% cases of preterm births occur due to microbial invasion in the genitourinary track. During inflammation, macrophages present at the feto-maternal junction release an increased amount ...

Optical nanoscopy is an emerging field and enables super-resolution of biological cells. Among the existing nanoscopy techniques, structured illumination microscopy (SIM) is most promising candidate for live cell imaging due to its high-imaging speed, limited photo-toxicity and its suitability with most commonly used fluorophore. One of research focus of the optics group at the department is to ...

The behavior of the autumn and winter weather pattern over Europe and Eurasia was investigated during two periods of high and low ice concentration in September over the Kara-Siberian sea. A statistically significant anomalous energy flux from the east Siberian sea to the atmosphere was detected during October of low ice years. Furthermore, an anomalous behavior in the atmospheric circulation was ...

The use of long-range memory models as a description of the noise in Earth surface temperatures has increased the recent years, and as a measure of the persistence for such time series we have the Hurst exponent. It is known that sea surface temperatures are more persistent than land temperatures, and that global temperatures are more persistent than local temperatures. We also know that the persistence ...

Oppgaven bygger på målinger av plasmadrift i den øvre atmosfære over Ny-Ålesund, Svalbard. Som målemetode er brukt "spaced receivers" metoden. I kap. 2 er satt opp modeller for solvind, magnetosfære og ionosfære og en ser på fenomen som forplanter seg fra solvinden til ionosfæren. Ved hjelp av disse modeller beregnes så drift av plasma i ionosfæren. I kap. 3 beskrives målemetoden. Diffraksjonsmekanismen ...

Petermann Glacier drains about 4% of the Greenland ice sheet area, with at least 80% of its mass loss through basal melting of the floating ice shelf. Utilizing a high-resolution coupled ice-shelf-ocean model, we aim at understanding the ocean circulation in Nares Strait and the mechanism of oceanic heat supply below the ice shelf as well as quantifying the basal mass loss. The numerical model is ...

This work is presenting a fully numerical approach for the direct solution of the Poisson equation for the electrostatic potential given by an arbitrary charge density. Efficient solution of this equation is important in many fields of science, where the current work is dealing with nuclear and electronic potential calculations, used in the field of computational chemistry. The equation is solved ...

Numerical simulations of reduced fluid models describing magnetized plasmas have previously been used to study the boundary of fusion plasmas extensively. A common approximation applied to these models is the so-called Boussinesq approximation. One of the requirements for the Boussinesq approximation to be applicable is that the background particle density is significantly higher than the fluctuations ...