Sökning: "photon transmission"

Visar resultat 1 - 5 av 40 avhandlingar innehållade orden photon transmission.

  1. 1. Light Scattering Effects in Transparent Wood Biocomposites

    Författare :Hui Chen; Lars Berglund; Ilya Sychugov; Max Yan; Mikael Sjödahl; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transparent wood; cellulose; biocomposite; light transmission; anisotropic scattering; Rayleigh scattering; photon budget; photon diffusion theory; light-transparent wood interaction; Transparent trä; cellulosa; biokomposit; ljustransmission; anisotropisk spridning; Rayleigh-spridning; fotonbudget; fotondiffusionsteori; ljus-transparent trä interaktion; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Sammanfattning : Transparent wood (TW) shows interesting optical properties and offers a sustainable alternative to petroleum-based polymer glasses. The influence of the TW internal structure (e.g. LÄS MER

  3. 2. Spectral Computed Tomography with a Photon-Counting Silicon-Strip Detector

    Författare :Mats Persson; Mats Danielsson; Hans Bornefalk; Jiang Hsieh; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Photon-counting; silicon-strip detector; spectral computed tomography; ring artifacts; fluence rate; basis material decomposition; sub-pixel information; Fysik; Physics;

    Sammanfattning : Computed tomography (CT) is a widely used medical imaging modality. By rotating an x-ray tube and an x-ray detector around the patient, a CT scanner is able to measure the x-ray transmission from all directions and form an image of the patient’s interior. LÄS MER

  4. 3. Mixed Beam Dosimetry - From Reactor Core to BNCT Patient

    Författare :Per Munck af Rosenschöld; Lund Medicinsk strålningsfysik; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; BNCT; dosimetry; radiotherapy; mixed beam; quality assurance; in vivo dosimetry; Monte Carlo; ionization chamber; foil activation; MCNP; beam quality correction factor; photon transmission.; Nukleärmedicin; radiobiology; Nuclear medicine; radiobiologi; Radiofarmaceutisk teknik; Radiopharmaceutical technology;

    Sammanfattning : Accurate radiation dosimetry is of paramount importance in order to ensure safe delivery of radiotherapy, and for the possibility of meaningful evaluation of clinical trials, as the radiation absorbed dose is correlated to tissue response. The aim of the studies described in this thesis was to investigate and devise novel approaches to mixed beam dosimetry in boron neutron capture therapy (BNCT). LÄS MER

  5. 4. Attenuation correction in pulmonary and myocardial single photon emission computed tomography

    Författare :Helén Almquist; Lund Klinisk fysiologi; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Klinisk fysiologi; tomography; medical instrumentation; radiology; Clinical physics; downscatter; myocardial perfustion; ventilation-perfusion ratio; radiologi; pulmonary density; pulmonary perfusion; attenuation correction; SPECT; transmission measurement; tomografi; medicinsk instrumentering;

    Sammanfattning : The objective was to develop and validate methods for single photon emission computed tomography, SPECT, allowing quantitative physiological and diagnostic studies of lung and heart. A method for correction of variable attenuation in SPECT, based on transmission measurements before administration of an isotope to the subject, was developed and evaluated. LÄS MER

  7. 5. Pharmaceutical and Biomedical Applications of Spectroscopy in the Photon Migration Regime

    Författare :Tomas Svensson; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Porosimetry; Biomedical optics; Pharmaceutical analysis; Monte Carlo; Scattering media; Photon migration; Laser spectroscopy; High-resolution spectroscopy; Time-resolved spectroscopy; Time-of-flight;

    Sammanfattning : The present thesis is devoted to two different matters: One part is the development of a novel optical technique for characterisation of solid pharmaceutical materials. The other part being the continued development of photon time-of-flight spectroscopy, as well as exploration of new application areas of this method. LÄS MER