Sökning: "Contour"

Visar resultat 21 - 25 av 85 avhandlingar innehållade ordet Contour.

  1. 21. Maximal Unitarity at Two Loops : A New Method for Computing Two-Loop Scattering Amplitudes

    Författare :Kasper J. Larsen; Lisa Freyhult; David Kosower; Joseph Minahan; Paul Heslop; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Amplitudes; NNLO calculations; Quantum Chromodynamics; Unitarity; Fysik med inriktning mot elementarpartikelfysik; Physics with specialization in Elementary Particle Physics;

    Sammanfattning : The study of scattering amplitudes beyond one loop is necessary for precision phenomenology for the Large Hadron Collider and may also provide deeper insights into the theoretical foundations of quantum field theory. In this thesis we develop a new method for computing two-loop amplitudes, based on unitarity rather than Feynman diagrams. LÄS MER

  3. 22. Dynamic neck formation in elastic-plastic tensile bars

    Författare :Kristina Nilsson; Mekanik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dynamic loading; necking; inertia; localization zones; numerical simulation; finite elements; non-linear;

    Sammanfattning : The time development of neck formation in ductile elastic-plastic bars is analyzed numerically in order to obtain a qualitative description of the features of dynamic neck localization under impact conditions. The full time history is visualized using contour plots of the time development of a strain rate parameter. LÄS MER

  4. 23. Frictional Effects on Hertzian Contact and Fracture

    Författare :Denis Jelagin; Per-Lennart Larsson; Bertil Storåkers; David Hills; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Contact mechanics; Elastic material; Friction; Nanoindentation; Fracture; Solid mechanics; Fastkroppsmekanik;

    Sammanfattning : This thesis addresses normal axisymmetric contact of dissimilar elastic solids at finite interfacial friction. It is shown that in the case of smooth and convex but otherwise arbitrary contact profiles and monotonically increasing loading a single stick-slip contour evolves being independent of loading and profile geometry. LÄS MER

  5. 24. Excavation damage from blasting with emulsion explosives : Quality control and macro fracturing in the remaining rock

    Författare :Henrik Ittner; Håkan Schunnesson; Daniel Johansson; Radoslava Ivanova; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gruv- och Berganläggningsteknik; Mining and Rock Engineering;

    Sammanfattning : Excavation damage is usually regulated in Swedish infrastructure tunnel contracts as it can influence the quality and lifecycle cost for tunneling projects. The topic is important for underground constructions with a long operation period such as tunnels for public transport, permanent access tunnels in mines or underground repositories for nuclear waste. LÄS MER

  7. 25. Mathematical Optimization Models and Methods for Open-Pit Mining

    Författare :Henry Amankwah; Torbjörn Larsson; Björn Textorius; Alexandra Newman; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MATHEMATICS; MATEMATIK;

    Sammanfattning : Open-pit mining is an operation in which blocks from the ground are dug to extract the ore contained in them, and in this process a deeper and deeper pit is formed until the mining operation ends. Mining is often a highly complex industrial operation, with respect to both technological and planning aspects. LÄS MER