Sökning: "Freja"

Visar resultat 1 - 5 av 6 avhandlingar innehållade ordet Freja.

  1. 1. Auroral Electric Fields From Satellite Observations and Numerical Modelling

    Författare :Tomas Karlsson; KTH; []
    Nyckelord :Satellite measurements; electric fields; ionosphere; magnetosphere; diverging electric fields; downward current region; black aurora; westward travelling surge; auroral bulge; subauroral ion drifts SAID ; subauroral electric fields SAEF ; mid-latit; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : This thesis is about electrodynamics of thehigh-latitude/auroral region of near-Earth space. The work ismainly based on electric field measurements made by the doubleprobe instrument on the Freja satellite at altitudes ofapproximately 800-1700 km, together with measurements fromother instruments on the same satellite, and ground-basedinstrumentation. LÄS MER

  3. 2. Satellite observations of auroral acceleration processes

    Författare :Lars Eliasson; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Aurora; particle acceleration; space plasma; magnetosphere; ionosphere; polar cap; satellite observations;

    Sammanfattning : Measurements with satellite and sounding rocket borne instruments contain important information on remote and local processes in regions containing matter in the plasma state. The characteristic features of the particle distributions can be used to explain the morphology and dynamics of the different plasma populations. LÄS MER

  4. 3. Alfvén Waves and Energy Transformation in Space Plasmas

    Författare :Yuri Khotyaintsev; Kalevi Mursula; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; Alfvén waves; particle acceleration; ionosphere; magnetopause; magnetic reconnection; Rymd- och plasmafysik; Space physics; Rymdfysik; Space Physics; rymdfysik;

    Sammanfattning : This thesis is focused on the role of Alfvén waves in the energy transformation and transport in the magnetosphere. Different aspects of Alfvén wave generation, propagation and dissipation are considered. The study involves analysis of experimental data from the Freja, Polar and Cluster spacecraft, as well as theoretical development. LÄS MER

  5. 4. Interaction between Electromagnetic Waves and Localized Plasma Oscillations

    Författare :Jan-Ove Hall; Thomas Leyser; Jan Trulsen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; space physics; plasma physics; radio waves; ionospheric modification; density depleations; field-aligned irregularities; lower hybrid solitary structures; lower hybrid cavities; Z mode waves; magnetosonic waves; scattering; mode conversion; Rymd- och plasmafysik; Space physics; Rymdfysik;

    Sammanfattning : This thesis treats interaction between electromagnetic waves and localized plasma oscillations. Two specific physical systems are considered, namely artificially excited magnetic field-aligned irregularities (striations) and naturally excited lower hybrid solitary structures (LHSS). LÄS MER

  7. 5. Allt annat än allvar : den komiska kvinnliga grotesken i svensk samtida skrattkultur

    Författare :Anna Lundberg; Nina Lykke; Hillevi Ganetz; Ellen Mortensen; Linköpings universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Carnival culture of laughter; comic; grotesque; feminism; queer theory; cultural studies; sex; gender; body; sexuality; rhizome; radio; Pride; sitcom; Skrattkultur; komik; grotesk; feminism; queerteori; kulturanalys; kön; kropp; sexualitet; rhizomatrik; radio; Pride; situationskomedi; Gender studies; Genus;

    Sammanfattning : Avhandlingen tar avstamp i ett möte mellan å ena sidan Michail Bachtins begrepp skrattkultur och hans positiva och uppvärderande framställning av grotesk estetik, och å andra sidan feministisk och queer teoribildning. Avhandlingen utgör en tvärvetenskaplig kulturstudie av svensk samtida skrattkultur, Mer specifikt fokuseras framställningar av kön, kropp och sexualitet. LÄS MER