Sökning: "Lars Johnson"

Visar resultat 1 - 5 av 25 avhandlingar innehållade orden Lars Johnson.

  1. 1. Inside The Miscibility Gap : Nanostructuring and Phase Transformations in Hard Nitride Coatings

    Författare :Lars Johnson; Lars Hultman; Magnus Odén; Michael Kopnarski; Linköpings universitet; []
    Nyckelord :;

    Sammanfattning : This thesis is concerned with self-organization phenomena in hard and wear resistant transition-metal nitride coatings, both during growth and during post deposition thermal annealing. The uniting physical principle in the studied systems is the immiscibility of their constituent parts, which leads, under certain conditions, to structural variations on the nanoscale. LÄS MER

  3. 2. Nanostructuring and Age Hardening in TiSCN, ZrAlN, and TiAlN Thin Films

    Författare :Lars Johnson; Lars Hultman; Axel Flink; Linköpings universitet; []
    Nyckelord :thin films; age hardening; spinodal decomposition; TiSiCN; ZrAlN; TiAlN; Transmission electron microscopy; Atom probe tomography; NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : This thesis explores nanostructuring in TiSiCN, ZrAlN, and TiAlN thin films deposited by cathodic arc evaporation onto cemented carbide substrates, with intended applications for cutting tools. The three systems were found to exhibit age hardening upon annealing, by different mechanisms, into the superhard regime (≥30 GPa), as determined by a combination of electron microscopy, X-ray diffraction, atom probe tomography, erda, and nanoindentation tech- niques. LÄS MER

  4. 3. Variance reduction methods for numerical solution of plasma kinetic diffusion

    Författare :Lars Josef Höök; Torbjörn Hellsten; Thomas Johnson; Lars-Göran Ericsson; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; variance reduction; Monte Carlo; quasi-Monte Carlo; kinetic diffusion; stochastic differential equation;

    Sammanfattning : Performing detailed simulations of plasma kinetic diffusion is a challenging task and currently requires the largest computational facilities in the world. The reason for this is that, the physics in a confined heated plasma occur on a broad range of temporal and spatial scales. LÄS MER

  5. 4. High-resolution characterization of TiN diffusion barrier layers

    Författare :Marlene Mühlbacher; Lars Hultman; Christian Mitterer; Lars Johnson; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Diffusion; TiN; Microstructure; Transmission electron microscopy; TEM; Atom probe tomography; APT;

    Sammanfattning : Titanium nitride (TiN) films are widely applied as diffusion barrier layers in microelectronic devices. The continued miniaturization of such devices not only poses new challenges to material systems design, but also puts high demands on characterization techniques. LÄS MER

  7. 5. Affective disorders in a stress-vulnerability perspective : a clinical, biological and psycho-social study

    Författare :Lars Johnson; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Affective illness; bipolar illness; unipolar illness; twin study; cognitive dysfunction; age of onset; early parental loss; life events; tryptophan depletion; lithium; social support; personality; outcome.;

    Sammanfattning : Affective illness is a common, recurrent and often severe illness, which causes severe suffering to the patients and their families, friends and co-workers. Furthermore the costs for society are substantial. LÄS MER