• Effect of permanent magnets on plasma confinement and ion beam generation in a double layer helicon plasma source 

      Varberg, Erik (Master thesis; Mastergradsoppgave, 2016-06-01)
      The work described in this thesis was carried out to investigate how additional permanent magnets (PM) could affect the confinement and ion beam generation in a plasma which expands from a helicon source. PMs added to a plasma source systems has been shown to provide an increased plasma confinement, but is not widely used. This inexpensive and cheap method of using PMs which does not require any ...
    • Effects of subglacial meltwater runoff on the ocean circulation beneath the Filchner Ice Shelf 

      Hus, Johanne Jahnsen (Mastergradsoppgave; Master thesis, 2023-06-15)
      Antarctic ice shelves, by restraining ice streams and affecting the discharge of grounded ice, play a critical role in the mass balance of the Antarctic ice sheet. In this study, sub-ice shelf CTD measurements and time series data from an ice shelf cavity mooring were used to detect subglacial runoff beneath the Filchner Ice Shelf. CTD measurements from four boreholes across the southern Filchner ...
    • The effects of time-variation of electron fluxes from the auroral ionosphere on M-I coupling 

      Gavazzi, Etienne (Master thesis; Mastergradsoppgave, 2022-05-15)
      Electric potential-differences between the magnetospheric and the ionospheric end of a magnetic flux tube lead to the downward acceleration of electrons in the ionosphere, producing visible auroral arcs. Most of the potential-drop is situated in a narrow altitude-region known as double layer. In the ionosphere, the precipitation of high-energy electrons will produce secondary electrons. Some ...
    • Estimation of Neutral Densities in the Thermosphere 

      Stock, Will (Master thesis; Mastergradsoppgave, 2017-05-17)
      Ionospheric energy balance is studied with incoherent scatter radar measurements that allow the estimation of neutral density and temperature from a statistical inversion problem. This method has been successfully studied at low latitudes using data over several years to make a robust model. This has not been done within the high latitude auroral regions and there are many factors that can complicate ...
    • Evaluating Deep Q-Learning Techniques for Controlling Type 1 Diabetes 

      Hjerde, Sigurd Thorvald Nordtveit (Master thesis; Mastergradsoppgave, 2020-02-13)
      Patients with type 1 diabetes (T1D) must continually decide how much insulin to inject before each meal to maintain an acceptable level of blood glucose. Recent research has worked on a solution for this burden: the artificial pancreas (AP), which is a closed-loop system combining a continuous glucose monitor (CGM) and an insulin pump with a decision-making algorithm. The goal of this thesis is ...
    • Filament motions in magnetized plasmas 

      Enikeev, Mikhail (Master thesis; Mastergradsoppgave, 2018-02-08)
      Interchange motions of magnetized plasmas due to either a non-uniform magnetic field or a gravitational field lead to charge polarization within a filamentary structure and set up convection. In this project we have provided a clear derivation of the two-field model equations that describe these filament motions. We have also derived an energy theorem for small amplitude oscillations. We have ...
    • Fotoelektriske observasjonar av stjerneokkultasjonar ved måneranda 

      Høydalsvik, Stein (Master thesis; Mastergradsoppgave, 1980-01)
      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 ...
    • Frequency-dependent magnetizability 

      Anelli, Marco (Master thesis; Mastergradsoppgave, 2010-11-15)
      This work discusses the theory of the magnetizability. The magnetizability is a molecular property defined as the second-order perturbation of the energy in the presence of an external magnetic field. When the magnetic field is static, perturbation and multipole theories lead to an origin-independent expression for the magnetizability, whereas for a frequency-dependent magnetic field its expression ...
    • The harmonizable representation of complex-valued nonstationary random processes 

      Hindberg, Heidi (Master thesis; Mastergradsoppgave, 2005-06-14)
      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 ...
    • The impact of Arctic late summer sea ice variability on mid-latitude autumn and winter weather. 

      Stoll, Patrick (Master thesis; Mastergradsoppgave, 2015-11-18)
      The influence of Arctic summer sea ice area on autumn and winter climate in the extra-tropic Northern hemisphere is investigated. During the last decades, the Arctic has warmed more than twice the global average rate, a phenomenon called the Arctic Amplification (AA). AA involves a remarkable decrease of the Arctic sea ice cover and a decrease of the latitudinal temperature gradient. Both are supposed ...
    • Investigation of inflammatory response of macrophages and trophoblasts using structured illumination microscopy 

      Singh, Rajwinder (Master thesis; Mastergradsoppgave, 2017-05-15)
      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 ...
    • Investigation of the ion composition in the topside ionosphere at solar maximum using incoherent scatter technique 

      Shulha, Maryna Oleksiivna (Master thesis; Mastergradsoppgave, 2016-05-15)
      The aim of this study was to investigate the altitudinal and diurnal variations of light ion densities in the topside ionosphere during the 23rd and 24th solar maximums. This made it possible to understand the behavior of the ion composition after extended solar minimum and compare how it differs from the preceding solar maximum. The observed variations are compared with estimates of empirical (IRI) ...
    • Investigation of Thermo-Optical Phase Modulator for Chip Based Structured Illumination Microscopy 

      Das, Sourov Kumar (Master thesis; Mastergradsoppgave, 2018-11-21)
      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 ...
    • Investigations of ionospheric disturbances using coherent HF instrumentation 

      Reznychenko, Artem (Master thesis; Mastergradsoppgave, 2016-05-15)
      This work is based on long term monitoring the HF signal data at 9.996 MHz at mid-latitudes from the short radio-path Moscow-Kharkiv and at high-latitudes from the longer radio-path Moscow-Tromso for 2013. The HF signal transmitter is the radio station RWM in Moscow, Russia. The receiver stations are located in Tromso (Norway) and Kharkiv (Ukraine). Using intensity and the Doppler frequency shift ...
    • Kara-Siberian sea ice anomaly and its impact on the atmosphere 

      Balafkan, Nozhan (Master thesis; Mastergradsoppgave, 2018-05-15)
      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 ...
    • Laser diagnostics of the mesospheric magnetic field. Understanding remote laser magnetometry in northern Norway 

      Serrano, Alessandra (Master thesis; Mastergradsoppgave, 2017-05-15)
      This thesis outlines initial motivations and propositions for the Mesospheric Optical Magnetometry (MOM) project, using lidar equipment at ALOMAR observatory in northern Norway to initiate a novel technique for measuring Earth’s magnetic field at approximately 90 km altitude. Included is an in-depth discussion of the physical phenomena within Earth’s mesospheric sodium layer, relevant atomic physics, ...
    • Long-range memory in Earth surface temperatures: spatial scale dependence and land-sea differences 

      Fredriksen, Hege-Beate (Master thesis; Mastergradsoppgave, 2013-05-15)
      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 ...
    • Low-frequency noise power spectrum density characterizing of SiGe HBTs 

      Qi, Peng (Master thesis; Mastergradsoppgave, 2006-06-06)
      The main purposes of this thesis are the Low-Frequency Noise measurement of Silicon-Germanium Heterojunction Bipolar Transistors and its Power Spectrum Density Characterizing. The new generation 375 GHZ SiGe HBTs were measured in this work. We show that most of PSDs of the new generation SiGe HBTs have very ”bumpy” spectra which is contributed by GR noise sources. We investigated their basic ...
    • Måling av plasmadrift i den øvre atmosfære over Ny-Ålesund, Svalbard. 

      Mikalsen, Egil Børge (Master thesis; Mastergradsoppgave, 1977-11)
      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 ...
    • Measuring Wind Using the Internal Stabilisation System of a Quadrotor Drone 

      Simma, Magdalena (Master thesis; Mastergradsoppgave, 2018-05-15)
      This thesis proposes a method of measuring wind using the data logged by the autopilot of a quadrotor drone. The approach is fundamentally different from other attempts found in the literature. Theoretical equations from works on quadrotor control are utilised and supplemented to form the theoretical framework. Static thrust tests provide the necessary parameters for calculating wind estimates. ...