Sökning: "radionuklider"

Visar resultat 16 - 19 av 19 avhandlingar innehållade ordet radionuklider.

  1. 16. Investigations of temporal changes in climate and the geomagnetic field via high-resolution radiocarbon dating

    Författare :Anette Mellström; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; wiggle-matching; Radiocarbon dating; 14C; 2800 cal BP; climate change; solar activity; palaeomagnetism; lake sediments; varves; post-depositional remanent magnetisation; PDRM; lock-in; peat deposits; Sweden;

    Sammanfattning : Geological archives have shown periods of abrupt climate change in the relatively stable Holocene epoch (last ca. 11 700 years). One of these periods was around 2800 cal BP. Several records, mainly from Europe, reveal a shift towards wetter, cooler and windier conditions. LÄS MER

  3. 17. Methods for localizing and quantifying radionuclide sources and deposition using in situ gamma spectrometry : Critical review of the peak-to-valley method based on experimental studies and applications in Georgia and Japan

    Författare :Karl Östlund; Malmö Medicinsk strålningsfysik; []
    Nyckelord :In situ gamma spectrometry;

    Sammanfattning : This thesis describes investigations made on mobile and stationary gammaspectrometry made both under laboratory conditions and in situ. The objective hasbeen to identify and quantify radionuclides in the form of point sources,contamination and widespread deposition in situations where the measurementgeometry is not known beforehand. LÄS MER

  4. 18. Superparamagnetic iron oxide nanoparticles (SPIONs) as a multimodality imaging probe for sentinel nodes : Design and Preclinical Evaluation

    Författare :Renata Madru; Lund Medicinsk strålningsfysik; []
    Nyckelord :iron oxide; nanoparticles; SPIONs; PET-MRI; SPECT-MRI; SPECT-MRI- optical imaging; sentinel lymph node; SNL;

    Sammanfattning : Breast cancer and malignant melanoma disseminate through the lymphatic system and the first metastases arise in one or two regional, sentinel lymph nodes (SLNs) draining the primary tumour site. Therefore, identification and characterization of the SLNs is of major importance for cancer staging and for choice of therapy in patients. LÄS MER

  5. 19. The Bentonite Barrier - Swelling Properties, Redox Chemistry and Mineral Evolution

    Författare :Daniel Svensson; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; montmorillonite; bentonite; smectite; freezing; thawing; hydration; intercalation; four-water-layer; ethylene glycol; X-ray diffraction; time-resolved; spatial-resolution; XANES; Fe; redox; iron; ABM; TBT; Äspö;

    Sammanfattning : Bentonite is planned for use as a buffer material in high-level radioactive waste repositories, where safety assessment is performed for very long periods (100-1000 ka). This thesis focuses on the swelling of smectites in liquid water, and analysis of bentonite from field experiments at Äspö Hard Rock Laboratory, Sweden. LÄS MER