Sökning: "Andreas Arvidsson"

Hittade 3 avhandlingar innehållade orden Andreas Arvidsson.

  1. 1. Development of an Automatic Reduction Tool for Chemical Mechanisms and an Optimized Sparse Matrix Solver for Systems of Differential and Algebraic Equations

    Författare :Andreas Arvidsson; Förbränningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Abstract An N-Heptane mechanism and a Methane/Propane mechanism have been reduced by an Automatic Reduction Tool (ART) and simulated with two different solver combinations, which solve the set of ordinary differential equations governing the time evolution of the species simultaneously with solving algebraic equations for species that can be considered to be in quasi steady state. The most successful of the two solver combinations is an optimized combination of Newton solvers. LÄS MER

  3. 2. Neuroprotection and neurogenesis after experimental stroke

    Författare :Andreas Arvidsson; Lund Neurologi; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; stereology; rat; Neurology; neuropsychology; neurophysiology; Neurologi; neuropsykologi; neurofysiologi; BrdU; immunohistochemistry; in situ hybridization; subventricular zone; striatum; dentate gyrus; neuronal replacement; neuronal survival; Focal cerebral ischemia; glial cell line-derived neurotrophic factor;

    Sammanfattning : In this thesis, two potential endogenous mechanisms for neuronal survival and repair have been investigated in a rat model of stroke, middle cerebral artery occlusion (MCAO): signaling of the GDNF family of neurotrophic factors, and neurogenesis from endogenous progenitor cells. As determined by in situ hybridization for GDNF family ligand and receptor genes, MCAO caused widespread upregulation of both components of the functional GDNF receptor, c-Ret and GFRalpha1, indicating that GDNF may be a survival signal in stroke. LÄS MER

  4. 3. Train–Track–Bridge Interaction for the Analysis of Railway Bridges and Train Running Safety

    Författare :Therese Arvidsson; Raid Karoumi; Andreas Andersson; Costin Pacoste; Guido De Roeck; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dynamics; railway bridge; bridge deck acceleration; train–bridge interaction; vehicle model; wheel–rail force; running safety; Civil and Architectural Engineering; Byggvetenskap;

    Sammanfattning : In this thesis, train–track–bridge interaction (TTBI) models are used to study the dynamic response of railway bridges. A TTBI model considers the dynamics of the train in addition to that of the track–bridge system. The TTBI model enables the assessment of train running safety and passenger comfort. LÄS MER