Sökning: "diffraction"

Visar resultat 11 - 15 av 1037 avhandlingar innehållade ordet diffraction.

  1. 11. Structure Determination and Prediction of Zeolites : A Combined Study by Electron Diffraction, Powder X-Ray Diffraction and Database Mining

    Författare :Peng Guo; Xiaodong Zou; Christine Kirschhock; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; zeolites; rotation electron diffraction; structure determination; structure prediction; strong reflections approach; Inorganic Chemistry; oorganisk kemi;

    Sammanfattning : Zeolites are crystalline microporous aluminosilicates with well-defined cavities or channels of molecular dimensions. They are widely used for applications such as gas adsorption, gas storage, ion exchange and catalysis. The size of the pore opening allows zeolites to be categorized into small, medium, large and extra-large pore zeolites. LÄS MER

  3. 12. Multiscale granular mechanics: A neutron diffraction based experimental approach

    Författare :Stefanos Athanasopoulos; Hållfasthetslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Granular media; Neutron diffraction; Plane-strain apparatus; Stress distribution; Localised stress-strain;

    Sammanfattning : Granular media (i.e., assemblies of grains, containing voids), such as sand, are highly complex materials, possessing inherently heterogeneous structure and properties that are manifested by the mobility and interaction of their constituent particles. Despite having been widely studied for centuries (i. LÄS MER

  4. 13. Elastic Wave Scattering by Cracks - Interfacial Forces and High Frequency Diffraction

    Författare :Gert Persson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultrasonic testing; Wiener-Hopf calculations; Geometrical Theory of Diffraction; edge diffracted body waves; PEDGE; two-dimensional diffraction; geometrical elastodynamic waves;

    Sammanfattning : This thesis treats elastic wave scattering by cracks with interfacial forces. The results are of practical interest in ultrasonic testing and includes development of numerical methods used to predict such testing. First the canonical problem of two-dimensional (2-D) diffraction from a semi-infinite crack is solved. LÄS MER

  5. 14. Structural Studies of Mn-X (X=Al, Bi): Permanent Magnetic Materials without Rare Earth Metals

    Författare :Hailiang Fang; Martin Häggblad Sahlberg; Peter Svedlindh; Samrand Shafeie; Linda Udby; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Synthesis; Magnetism; Diffraction.; Chemistry with specialization in Inorganic Chemistry; Kemi med inriktning mot oorganisk kemi;

    Sammanfattning : How to generate and use electricity in a more efficient way is a major challenge for humankind. In this context, permanent magnets play an important role within a very broad range of electric power applications. The strongest magnets used today are mainly based on alloys that contain rare-earth metals, which are neither economical nor sustainable. LÄS MER

  7. 15. Seismic Exploration Solutions for Deep-Targeting Metallic Mineral Deposits : From high-fold 2D to sparse 3D, and deep-learning workflows

    Författare :Magdalena Markovic; Alireza Malehmir; Gilles Bellefleur; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Exploration; Seismic; Mineral Deposits; Diffraction; Deep learning;

    Sammanfattning : Mineral exploration has in recent years moved its focus to greater depths than ever before, particularly in brown fields. Exploring new deposits at depth, if economical, would not only expand the life of mine but also provide minimal environmental impacts. It allows the existing mining infrastructures to be used for a longer period. LÄS MER