Sökning: "radiation scatter"

Visar resultat 1 - 5 av 19 uppsatser innehållade orden radiation scatter.

  1. 1. Evaluation of a Novel Reconstruction Framework for Gamma Knife Cone-Beam CT - The Impact of Scatter Correction and Noise Filtering on Image Quality and Co-registration Accuracy

    Master-uppsats, KTH/Fysik

    Författare :Ida Hägnestrand; [2023]
    Nyckelord :Gamma Knife; Cone-beam computed tomography; Image quality; Image reconstruction; Co-registration; Contrast; Uniformity; Spatial resolution; Scatter correction; Wiener filter; Noise filter; Patient positioning; Stereotactic radiosurgery; Gammakniv; Strålkniv; Cone-Beam Computed Tomography; Bildkvalitet; Bildrekonstruktion; Co-registrering; Kontrast; Uniformitet; Spatial upplösning; Spridningskorrigering; Wienerfilter; Brusfilter; Stereotaktisk strålkirurgi;

    Sammanfattning : The Gamma Knife is a non-invasive stereotactic radiosurgery system used for treatments of deep targets in the brain. Accurate patient positioning is needed for precise radiation delivery to the target. LÄS MER

  3. 2. Development and Evaluation of an Enzyme-Based Sunscreen

    Master-uppsats, Lunds universitet/Bioteknik; Lunds universitet/Bioteknik (master)

    Författare :Karolina Eriksson Torfgård; [2023]
    Nyckelord :Enzyme activity; UV-filter; Protease; Biotechnology; Technology and Engineering;

    Sammanfattning : Ultraviolet radiation (UVR), specifically of UVA and UVB, has been associated with the development of both photoaging and photo-carcinogenesis, potentially leading to cancer. The use of sun protection in the form of UV filters is known to minimize these damages. LÄS MER

  4. 3. Time-resolved x-ray diffraction study of longitudinal optical phonons in zincblende semiconductors

    Master-uppsats, Lunds universitet/Atomfysik; Lunds universitet/Fysiska institutionen

    Författare :Lassi Linnala; [2022]
    Nyckelord :femtosecond THz radiation; ultrafast x-ray diffraction; pump-probe; longitudinal optical phonons; zincblende semiconductors; anharmonic decay; density functional perturbation theory; Physics and Astronomy;

    Sammanfattning : Anharmonic decay of longitudinal optical (LO) phonons in zincblende semiconductors is not at present well characterized due to the polar and many-body nature of the problem. Femtosecond THz radiation offers a novel route to this study, as the interaction of this radiation is directly with the phonon lattice and these THz excited phonons do not have enough energy to excite electrons over the band gap. LÄS MER

  5. 4. Quantification of I-131 Activity from Gamma Camera Images of Thyroid Cancer Patients

    Master-uppsats, Lunds universitet/Sjukhusfysikerutbildningen

    Författare :Frida Westerbergh; [2019]
    Nyckelord :Physics and Astronomy;

    Sammanfattning : BACKGROUND: Radioiodine (131I) has been used in thyroid cancer treatments for many years, and has demonstrated good results with regards to disease management. Radioiodine therapy is however partially empirical, as not very much is known concerning radiation dosimetry. LÄS MER

  7. 5. Radiation exposure to personnel during fluoroscopic procedures : Strålningsmiljö för personal under genomlysningsarbete

    Kandidat-uppsats, Karlstads universitet/Institutionen för ingenjörsvetenskap och fysik (from 2013)

    Författare :Olof Eriksson; [2018]
    Nyckelord :;

    Sammanfattning : There are about 17 million X-ray procedures performed in Sweden every year. Various methods are used to determine the risk for the patient, and for the staff. LÄS MER