Search for dissertations about: "Beams"

Showing result 21 - 25 of 451 swedish dissertations containing the word Beams.

  2. 21. Development of improved radiation therapy techniques using narrow scanned photon beams

    Author : Björn Andreassen; Anders Brahme; Håkan Danared; Roger Svensson; Antony Lomax; Stockholms universitet; []
    Keywords : IMRT; Scanned photon beams; PET-CT treatment verification; Monte Carlo; NATURAL SCIENCES; NATURVETENSKAP; Medical Radiation Physics; medicinsk strålningsfysik;

    Abstract : The present thesis is focused on the development and application of narrow scanned high energy photon beam for radiation therapy. The introduction of physically and biologically optimized intensity modulated radiation therapy (IMRT) requires a flexible and accurate dose delivery method to maximize the treatment outcome. READ MORE

  4. 22. Nonlinear Propagation of Optical Pulses and Beams

    Author : Magnus Karlsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; self-phase modulation; optical wave breaking; paraxial-ray approximation; stimulated Raman scattering; nonlinear Schrödinger equation; optical collapse; modulational instability; higher-order dispersion; optical fibers; saturable nonlinearity; Kerr-nonlinearity; self-trapping; group-velocity dispersion; optical solitons; self-focusing;

    Abstract : The propagation of optical beams and pulses under the influence of nonlinear effects is characterized by a rich variety of phenomena and many potentially important applications. We analyse two main topics in this context: nonlinear beam propagation, and nonlinear pulse propagation in optical fibers. READ MORE

  5. 23. FRP shear strengthening of reinforced concrete beams

    Author : Gabriel Sas; Giorgio Monti; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fiber reinforced polymers; shear; reinforced concrete; strengthening; model; comparison; literature review; Structural Engineering; Konstruktionsteknik;

    Abstract : The shear failure mechanisms of flexural reinforced concrete (RC) members is highly complex; its precise details cannot be explained with simple analytical relationships, and are the topic of considerable scientific debate. The studies described and examined the three most used shear theories in the world – the fixed angle truss model (45°TM), the variable angle truss model (VAT), and modified compression field theory (MCFT). READ MORE

  6. 24. Instrumentation development for physics with antiproton beams

    Author : Klas Marcks von Würtemberg; Per-Erik Tegnér; Eberhard Widmann; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; fysik; Physics;

    Abstract : This thesis summarises work done in the preparation for the PANDA (antiproton ANnihilations at DArmstadt) experiment, that will be built at the HESR (High Energy Storage Ring) at FAIR (Facility for Antiproton and Ion Research) and for the PAX (Polarised Antiproton eXperiment) experiment proposed for the HESR.For PANDA, characteristics of the electromagnetic calorimeter have been measured at the tagged photon beam facility at the MAX IV laboratory for 61 photon energies in the range 12-63 MeV. READ MORE

  7. 25. Micro/nanometric Scale Study of Energy Deposition and its Impact on the Biological Response for Ionizing Radiation : Brachytherapy radionuclides, proton and carbon ion beams

    Author : Fernanda Villegas Navarro; Anders Ahnesjö; Carmen Villagrasa; Uppsala universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Ionizing radiation; Monte Carlo track structure code; Microdosimetric spread; Energy deposition clustering; RBE; Medicinsk radiofysik; Medical Radiophysics;

    Abstract : Research in radiotherapy for cancer treatment focuses on finding methods that can improve the compromise between tumour cell inactivation versus damage to the surrounding healthy tissue. As new radiation modalities such as proton therapy become accessible for everyday clinical practice, a better understanding of the variation in biological response of the tumour and healthy tissues would improve treatment planning to achieve optimal outcome. READ MORE