Sökning: "14C"

Visar resultat 1 - 5 av 131 avhandlingar innehållade ordet 14C.

  1. 1. Testing palaeomagnetic and 14C based geochronological methods in the Baltic Sea

    Författare :Bryan Lougheed; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Baltic Sea; coastal; geochronology; palaeomagnetic secular variation; PSV; radiocarbon; 14C; reservoir age; R t ; ΔR; salinity; δ18O; geomagnetic field; Holocene; deglacial; Fennoscandia.;

    Sammanfattning : The Baltic Sea is a continental shelf sea that is influenced by both river runoff and marine water. The two water masses are vertically stratified in the Baltic Sea, resulting in a positive, estuarine circulation system, which has undergone changes in the past due to isostatic uplift of the Baltic basin. LÄS MER

  3. 2. Biokinetics and radiation dosimetry of 14C-labelled triolein, urea, glycocholic acid and xylose in man. Studies related to nuclear medicine “breath tests” using accelerator mass spectrometry

    Författare :Mikael Gunnarsson; Malmö Medicinsk strålningsfysik; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Clinical physics; radiology; tomography; medical instrumentation; Klinisk fysiologi; radiologi; tomografi; medicinsk instrumentering; Kärnfysik; Nuclear physics; xylose.; glycocholic acid; urea; triolein; Dosimetry; Biokinetic; AMS; Accelerator mass spectrometry; 14C; Breath test;

    Sammanfattning : 14C-labelled substances have been used in biomedical research and clinical medicine for over 50 years. Physicians and scientists however, often hesitate to use these substances in patients and volunteers because the radiation dosimetry is unclear. LÄS MER

  4. 3. Solar Activity Changes at the End of the Last Ice Age - Influences on Climate and Applications for Dating

    Författare :Florian Adolphi; BECC: Biodiversity and Ecosystem services in a Changing Climate; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Solar Activity; 10Be; 14C; radiocarbon calibration; time scale; geochronology; paleoclimate; ice cores; tree rings; IntCal; cosmogenic radionuclides;

    Sammanfattning : Throughout its history Earth experienced a variety of natural climate changes. By investigating their spatial and temporal evolution we can increase the understanding of the mechanisms and dynamics underlying natural climate change and improve our general comprehension of the climate system. LÄS MER

  5. 4. 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

  7. 5. Solar variability over the Holocene period : disentangling geomagnetic and solar influences on a new continuous 10Be record from Little Dome C, Antarctica

    Författare :Hoang Long Nguyen; MERGE: ModElling the Regional and Global Earth system; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ice core; cosmogenic radionuclide; 10Be; 14C; solar activity; paleomagnetism; ; Holocene;

    Sammanfattning : Reliable information on solar activity over the Holocene period is important to predict the Sun in the future and to understand the mechanism behind the Sun-climate linkage. Presently, there are discrepancies in the proxy data of solar activity due to reasons that are not yet understood. LÄS MER