Search for dissertations about: "Density contrast"

Showing result 1 - 5 of 261 swedish dissertations containing the words Density contrast.

  1. 1. Liquid-Jet-Target Microfocus X-Ray Sources Electron Guns, Optics and Phase-Contrast Imaging

    University dissertation from Stockholm : KTH

    Author : Tomi Tuohimaa; KTH.; [2008]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electron-impact; x-ray; brightness; liquid-jet-target; phase-contrast imaging; TECHNOLOGY Engineering physics; TEKNIKVETENSKAP Teknisk fysik;

    Abstract : This Thesis describes the development of an electron-impact microfocus x-ray source and its application for phase-contrast imaging. The source is based on a novel, liquid-jet target concept. Stable and continuous operation can be achieved at substantially higher electron-beam power densities than conventional solid target based systems. READ MORE

  2. 2. Forest edges in boreal landscapes - factors affecting edge influence

    University dissertation from Stockholm : KTH

    Author : Ulrika Jansson; Umeå universitet.; [2009]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; aerial photographs; edge contrast; edge density; edge length; fetch size; forest fragmentation; lichen growth; line intersect sampling; pendulous lichen; photo interpretation; skogskant; flygbild; kantlängd; lav; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology Terrestrial ecology; NATURVETENSKAP Biologi Terrestisk; limnisk och marin ekologi Terrestisk ekologi; ekologisk botanik; Ecological Botany;

    Abstract : The boreal forest in Fennoscandia has been subjected to major loss and fragmentation of natural forests due to intensive forestry. This has resulted in that forest edges are now abundant and important landscape features. Edges have documented effects on the structure, function and biodiversity in forests. READ MORE

  3. 3. Laser-Driven Particle Acceleration - Improving Performance Through Smart Target Design

    University dissertation from Camilla Nilsson, Department of Physics, Division of Atomic Physics, Lund University

    Author : Matthias Burza; Lunds universitet.; Lund University.; [2012]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; wakefield; ultra-relativistic; ultra-intense; TNSA; Terawatt; sheath; proton; polarimetry; plasma mirror; plasma; Petawatt; particle; oscillation; Normarski; micromachining; LWFA; laser; interferometry; electron; contrast; acceleration; bubble; Fysicumarkivet A:2012:Burza;

    Abstract : Popular Abstract in Swedish Många forskningsprojekt inom materialvetenskap, medicin eller grundläggande fysik kräver smala strålar av laddade partiklar som fungerar som provtagare för att undersöka materiens egenskaper. Dessa partiklar kan vara protoner, elektroner lättare joner. READ MORE

  4. 4. Mammographic breast density and postmenopausal hormone therapy

    University dissertation from Stockholm : Karolinska Institutet, Department of Women's and Children's Health

    Author : Eva Lundström; Karolinska Institutet.; Karolinska Institutet.; [2005]
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Mammographic breast density; mammography; menopause; hormone therapy; tibolone; low dose intrauterine progestogen; Syndecan-1.;

    Abstract : Breast cancer is the most frequent malignancy among women in the western world. More than one million women are estimated to be diagnosed with the disease every year. The breast is a target organ for sex steroids and hormonal treatments have been found to increase the risk for breast cancer. READ MORE

  5. 5. Are gadolinium contrast media really less nephrotoxic than iodine agents in radiographic examinations? A comparison in relation to their ability to attenuate x-rays in a pig model

    University dissertation from Department of Clinical Sciences, Lund University

    Author : Barbara Elmståhl; Lunds universitet.; Lund University.; [2006]
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Angiography; Computed tomography; toxicity; Contrast media; Glomerular filtration; Gadolinium; Iodine; Kidney failure; Nephrotoxicity.; Medicin människa och djur ; radiology; Clinical physics; Medicine human and vertebrates ; tomography; medical instrumentation; Diagnostik; Diagnostics; medicinsk instrumentering; tomografi; radiologi; Klinisk fysiologi;

    Abstract : Purpose: To confront the statement that gadolinium contrast media (Gd-CM) are less nephrotoxic than iodine contrast media (I-CM) when used in x-ray angiographic and computed tomographic (CT) examinations. Methods: I) For CT measurements (mean density in Hounsfield numbers) 20-mL syringes filled with I- and Gd-CM at 0.01, 0.02, 0. READ MORE