Sökning: "dispersion relations"

Visar resultat 21 - 25 av 39 avhandlingar innehållade orden dispersion relations.

  1. 21. Stellar Surface Structures and the Astrometric Serach for Exoplnaets

    Författare :Urban Eriksson; Lindegren Lennart; Kristianstad University; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astrometry; astronomy;

    Sammanfattning : Measuring stellar parallax, position and proper motion is the task of astrometry. With the development of new and much more accurate equipment, different noise sources are likely to affect the very precise measurements made with future instruments. LÄS MER

  3. 22. Waves and instabilities in quantum plasmas

    Författare :Shahid Ali; Padma Kant Shukla; Mattias Marklund; Jose Tito Mendonca; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum mechanical effects; dusty plasma; linear and nonlinear waves; instabilities; nonlinear wave interactions; density gradients; magnetoplasmas.; Plasma physics; Plasmafysik;

    Sammanfattning : The study of waves and instabilities in quantum plasmas is of fundamental importance for understanding collective interactions in superdense astrophysical objects, in high intense laser-plasma/solid-matter interactions, in microelectronic devices and metallic nanostructures. In dense quantum plasmas, there are new pressure laws associated with the Fermi-Dirac distribution functions and new quantum forces associated with the quantum Bohm potential and the Bohr magnetization involving electron ½ spin. LÄS MER

  4. 23. Theory of Random Matrices and Elasticity Applied to Nanowires and Mechanical Vibrations

    Författare :Johan Grönqvist; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis presents work in several areas relating to Random Matrix Theory and Elasticity. It contains 4 papers presenting work on different issues. Paper I concerns correlations between eigenvalues in random matrices of real symmetric (GOE) or quaternion real (GSE) form. LÄS MER

  5. 24. Elasticity of Cellulose Nanofibril Materials

    Författare :Gabriella Josefsson; E. Kristofer Gamstedt; Karin de Borst; Uppsala universitet; []
    Nyckelord :Cellulose nanofibrils; Elastic properties; Micromechanics; Composites; Engineering science with specialization in Applied Mechanics; Teknisk fysik med inriktning mot tillämpad mekanik;

    Sammanfattning : The demand for renewable load-carrying materials is increasing with increasing environmental awareness. Alternative sources for materials manufacturing and design have to be investigated in order to replace the non-biodegradable materials. LÄS MER

  7. 25. The Use of GIS in Assessing Exposure to Airborne Pollutants

    Författare :Emilie Stroh; Avdelningen för arbets- och miljömedicin; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NOx; air pollution; GIS; Exposure assessment; Lead; NO2;

    Sammanfattning : GIS (Geographical Information System) has become a valuable tool in air pollution exposure assessment studies due to its abilities to accurately model and estimate exposure for large populations and areas. The general aim of the work presented in this thesis was to investigate the factors that affect the validity and precision in the assessment of human exposure to airborne pollution using GIS. LÄS MER