Sökning: "Thomas Silva"

Hittade 4 avhandlingar innehållade orden Thomas Silva.

  1. 1. Aspects of material and heat transfer in drop- and powder-based laser additive manufacturing

    Författare :Adrien Da Silva; Jan Frostevarg; Alexander Kaplan; Thomas Graf; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Produktionsutveckling; Manufacturing Systems Engineering;

    Sammanfattning : Additive Manufacturing became a major research topic and part of industrial production in the past years. Numerous techniques now allow to build 3D structures with a wide choice of materials. When it comes to processing of metals, a laser beam is often used as a heat source to melt either a wire or powder. LÄS MER

  3. 2. Investigation of Suffusion in Glacial Till Dam Cores : Testing methods and critical hydraulic gradients

    Författare :Ingrid Silva; Jan Laue; Peter Viklander; Thomas Pabst; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; internal erosion; suffusion; glacial till; dam cores; dams; experimental investigation; hydraulic gradient; testing methods; cohesionless soils; granular soils; Geoteknik; Soil Mechanics;

    Sammanfattning : Suffusion is an internal erosion mechanism that occurs in embankment dams when fine grained particles in the dam core are washed out by seepage. Initiation of internal erosion depends mainly on three major factors: grain size distribution of the soil, stress conditions and hydraulic gradient; whilst its continuation depends on the properties of the filter. LÄS MER

  4. 3. Magnetization Dynamics in Nano-Contact Spin Torque Oscillators : Solitonic bullets and propagating spin waves

    Författare :Stefano Bonetti; Johan Åkerman; Thomas Silva; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetism; spintronics; thin magnetic films; spin transfer torque; magnetization dynamics; spin waves; microwave oscillators; giant magneto-resistance; Magnetism; Magnetism;

    Sammanfattning : Magnetization dynamics in nano-contact spin torque oscillators (STOs) is investigated from an experimental and theoretical point of view. The fundamentals of magnetization dynamics due to spin transfer torque are given. A custom-made high frequency (up to 46 GHz) in large magnetic fields (up to 2. LÄS MER

  5. 4. Resonant switching and vortex dynamics in spin-flop bi-layers

    Författare :Sergiy Cherepov; Vladislav Korenivski; Thomas Silva; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spin-dynamics; MRAM; vortex; switching; Condensed matter physics; Kondenserade materiens fysik; Magnetism; Magnetism; Mesoscopic physics; Mesoskopisk fysik;

    Sammanfattning : This thesis is a study of the static and dynamic behavior of the magne-tization in spin-flop bi-layers, which consist of two soft ferromagnetic layerscoupled by dipolar forces through a thin nonmagnetic spacer. The focus ofthe work is three fold: collective spin dynamics in the anti-parallel groundstate; resonant switching in the presence of thermal agitation; and static anddynamic behavior of the system in the vortex-pair state, with a particularemphasis on the interlayer core-core interaction. LÄS MER