Search for dissertations about: "Å Nilsson"

Showing result 1 - 5 of 9 swedish dissertations containing the words Å Nilsson.

  2. 1. Species interactions in streams - effects of predation, competition and ecosystem properties

    Author : Erika Nilsson; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; behaviour; species abundance; stable isotopes; habitat complexity; niche width; niche overlap; competition; streams; predation;

    Abstract : Stream ecosystems are dynamic and they have an inherent environmental variability. Organisms that live in streams are adapted to the continuously changing environment and the presence or absence of species are determined by their environmental requirements, while abundance is most often affected by interactions, such as competition and predation, with other species that are found in the same habitat. READ MORE

  4. 2. Unifying first-principles and model approaches for strongly correlated materials : Interplay between long- and short-range correlations

    Author : Fredrik Nilsson; Matematisk fysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; first-principle methods; strongly correlated materials; GW approximation; cRPA; random-phase approximation; dynamical mean-field theory; GW DMFT; downfolding;

    Abstract : In materials with open 3$d$ and 4$f$ shells the valence electrons are relatively localized around the atoms which leads to large electron-electron correlations. These, so called strongly correlated materials, exhibit many intriguing properties such as high $T_c$ superconductivity, colossal magneto-resistance and heavy fermion behaviour. READ MORE

  5. 3. Coherent Interactions in Rare-Earth-Ion-Doped Crystals for Applications in Quantum Information Science

    Author : Mattias Nilsson; Atomfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; quantum optics; relaxation; magnetic resonance; supraconductors; magnetic and optical properties; electrical; Condensed matter:electronic structure; Atom- och molekylärfysik; optical information processing; coherence in solids; Atomic and molecular physics; rare-earth-ion-doped crystals; magnetisk resonans; spektroskopi; supraledare; magnetiska och optiska ; egenskaper elektriska; Kondenserade materiens egenskaper:elektronstruktur; spectroscopy; quantum information;

    Abstract : This thesis describes investigations of the use of cryogenically cooled rare-earth-ion-doped crystals for quantum information processing and quantum optics. Several aspects of the coherent interaction between light and rare-earth ions in solids are addressed. Quantum information science has given physicists new views of quantum mechanics. READ MORE

  6. 4. Extraction of logging residues for bioenergy : effects of operational methods on fuel quality and biomass losses in the forest

    Author : Bengt Nilsson; Johan Bergh; Gudmund Vollbrecht; Rolf Björheden; Linnéuniversitetet; []
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; Forest fuel; Storage; Fraction composition; Needles; Defoliation; Moisture content; Nutrients; Nitrogen; Norway spruce; Picea abies; Skogsbränsle; Lagring; Fraktionsfördelning; Barr; Avbarrning; Fukthalt; Näringsämnen; Kväve; Gran; Picea abies; Forestry and Wood Technology; Skog och träteknik;

    Abstract : Wood products play a key role in the transformation to a more sustainable society based on renewable bio-based resources, together with the positive effects on climate mitigation by replacing fossil fuels. However, to increase the use of forest fuel in practice it is important to understand the effects of handling and storage on its quality and removal of nutrients from the forest. READ MORE

  7. 5. Itch and Pain Inhibitory Mechanisms in Humans - evidence for a differential control of nociceptive senses

    Author : Hans-Jörgen Nilsson; Neurofysiologi; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; neuropsychology; Neurology; Human; TENS; Somatosensory; Pruritus; Analgesia; Pain; Nociception; neurophysiology; Neurologi; neuropsykologi; neurofysiologi;

    Abstract : It is known that stimulation of thin nerve afferents can inhibit itch and pain and that the nociceptive systems have a detailed topographical organisation, with subsystems exhibiting specific excitatory and inhibitory receptive fields. On this basis, a new technique was developed, termed Cutaneous Field Stimulation (CFS), that electrically stimulates thin nerve fibers innervating specific skin fields. READ MORE