Sökning: "Penrose"

Visar resultat 6 - 9 av 9 avhandlingar innehållade ordet Penrose.

  1. 6. Frustrated magnetism in icosahedral structures : The influence of order-disorder in quasicrystals and approximant crystals

    Författare :Fernand Denoel; Roland Mathieu; Marc de Boissieu; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quasicrystals; approximant crystals; spin glasses; SQUID magnetometry; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : This work will begin with an introduction to quasicrystals (QCs) and their structure, defining the unit cell-equivalent for icosahedral quasiperiodicity: a 3D tiling based on the golden ratio and aperiodic in all three dimensions. We briefly present the cut-and-project method used to generate QCs from a higher dimension hypercrystal, and how to build the 3D Penrose tilings, composed of the two golden rhombohedra. LÄS MER

  3. 7. A study of asymptotically hyperbolic manifolds in mathematical relativity

    Författare :Anna Sakovich; Mattias Dahl; James Isenberg; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis consists of ve papers where certain problems arising in mathematical relativity are studied in the context of asymptotically hyperbolic manifolds.In Paper A we deal with constant mean curvature solutions of the Einstein-scalar field constraint equations on asymptotically hyperbolic manifolds. LÄS MER

  4. 8. A Wave Expansion Method for Aeroacoustic Propagation

    Författare :Johan Hammar; Gunilla Efraimsson; Ciarán J. O'Reilly; Wim De Roeck; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Sound propagation; Sound generation; Aeroacoustics; Aerodynamics; Computational fluid dynamics; Computational aeroacoustics; Numerical methods; Lighthill; Curle; Ffowcs Williams and Hawkings; Frequency-domain propagation; Wave expansion method.; Vehicle and Maritime Engineering; Farkostteknik;

    Sammanfattning : Although it is possible to directly solve an entire flow-acoustics problem in one computation, this approach remains prohibitively large in terms of the computational resource required for most practical applications. Aeroacoustic problems are therefore usually split into two parts; one consisting of the source computation and one of the source propagation. LÄS MER

  5. 9. Biological Inspired Deformable Image Sensor

    Författare :Wei Wen; Khatibi Siamak; Coleman Sonya; Blekinge Tekniska Högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; image sensor; pixel form; sub-arrangements; fill factor; square image; hexagonal image; deformable sensor; quality assessment.;

    Sammanfattning : Nowadays, cameras are everywhere thanks to the tremendous progress on sensor technology. However, their performance is far away from what we experience by our eyes. LÄS MER