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Visar resultat 1 - 5 av 7 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Conservation of the wood of the Swedish warship Vasa of A.D. 1628. Evaluation of polyethylene glycol conservation programmes

    Författare :Birgitta Håfors; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Anti shrink efficiency ASE ; archaeological wet site; dimensional stabilisation; conservation; osmosis; polyethylene glycol PEG ;

    Sammanfattning : The principal aim of this dissertation is to investigate whether or not polyethylene glycol (PEG) has acted as a dimension stabilizing agent of the Vasa wooden material, i.e. LÄS MER

  3. 2. Spectral-element simulations of turbulent wall-bounded flows including transition and separation

    Författare :Johan Malm; Dan Henningson; Philipp Schlatter; Suad Jakirlic; KTH; []
    Nyckelord :spectral-element method; direct numerical simulation DNS ; large-eddy simulation LES ; turbulence; transition; over-integration; three-dimensional separation; massively parallel simulations; proper orthogonal decomposition POD ; Koopman modes; vorticity stretching; coherence; SRA - E-vetenskap SeRC ; SRA - E-Science SeRC ;

    Sammanfattning : The spectral-element method (SEM) is used to study wall-bounded turbulent flowsin moderately complex geometries. The first part of the thesis is devoted to simulations of canonical flow cases, such as temporal K-type transitionand turbulent channel flow, to investigate general resolution requirements and computational efficiency of the numerical code nek5000. LÄS MER

  4. 3. Receptivity of crossflow-dominated boundary layers

    Författare :David Tempelmann; Ardeshir Hanifi; Dan Henningson; Anatoli Tumin; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Receptivity; three-dimensional boundary layers; optimal growth; adjoint solutions; swept wing;

    Sammanfattning : This thesis deals with receptivity mechanisms of three-dimensional, crossflow-dominated boundary layers. The receptivity of two model problems, a swept-flat-plate and a swept-wing boundary layer, is investigated by solving the parabolised stability equations (PSE) as well as by performing direct numerical simulations (DNS). LÄS MER

  5. 4. Geometric Computer Vision for Rolling-shutter and Push-broom Sensors

    Författare :Erik Ringaby; Per-Erik Forssén; Anders Heyden; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rolling shutter cmos video rectification stabilisation push-broom kinect;

    Sammanfattning : Almost all cell-phones and camcorders sold today are equipped with a CMOS (Complementary Metal Oxide Semiconductor) image sensor and there is also a general trend to incorporate CMOS sensors in other types of cameras. The sensor has many advantages over the more conventional CCD (Charge-Coupled Device) sensor such as lower power consumption, cheaper manufacturing and the potential for on-chip processing. LÄS MER

  7. 5. Nuclear Magnetic Resonance Spectroscopy and Spin Relaxation in Amphiphilic Liquid Crystals

    Författare :Stefan Gustafsson; Kemisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Fysicumarkivet A:1997:Gustafsson;

    Sammanfattning : Spin relaxation theory and nuclear magnetic resonance spectroscopy in amphiphilic liquid crystals are presented. Group theory is used to determine the information content and the orientation dependence in spin relaxation experiments, and to investigate the combined effect of crystal and local symmetries and the effect of symmetry on multiple timescales. LÄS MER