Sökning: "Ala Aldahan"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden Ala Aldahan.

  1. 1. Mineral diagenesis and petrology of the Dala Sandstone, central Sweden

    Författare :Ala Aldahan; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The Dala Sandstone, of Proterozoic age, is the most extensive sedimentary unit in central Sweden. The rocks are quartz sandstones, lithic sandstones, feldspathic sandstones, arkoses and greywackes with intercalations of shales and siltstones less than 1 m thick. The Öje Basalt divides the sedimentary sequence into two parts. LÄS MER

  3. 2. Accelerator Mass Spectrometry of 36Cl and 129I : Analytical Aspects and Applications

    Författare :Vasily Alfimov; Göran Possnert; Ala Aldahan; Hans-Arno Synal; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Environmental technology; Accelerator Mass Spectrometry; iodine-129; chlorine-36; gas-filled magnet; radioactive tracer; Arctic Ocean; Nordic Seas; North Atlantic; thermohaline circulation; Sellafield; La Hague; Miljöteknik; Environmental engineering; Miljöteknik;

    Sammanfattning : Two long-lived halogen radionuclides (36Cl, T1/2 = 301 kyr, and 129I, T1/2 = 15.7 Myr) have been studied by means of Accelerator Mass Spectrometry (AMS) at the Uppsala Tandem Laboratory. The 36Cl measurements in natural samples using a medium-sized tandem accelerator (~1 MeV/amu) have been considered. LÄS MER

  4. 3. Influence of solar activity and environment on 10Be in recent natural archives

    Författare :Ann-Marie Berggren; Ala Aldahan; Göran Possnert; Anne Hormes; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cosmogenic isotopes; beryllium; ice cores; varved lake sediments; accelerator mass spectrometry; co-precipitation; Quaternary geology; Kvartärgeologi;

    Sammanfattning : Understanding the link between the Sun and climate is vital in the current incidence of global climate change, and 10Be in natural archives constitutes an excellent tracer for this purpose. As cosmic rays enter the atmosphere, cosmogenic isotopes like 10Be and 14C are formed. LÄS MER

  5. 4. Anthropogenic 129I Traced in Environmental Archives by Accelerator Mass Spectrometry

    Författare :Edvard Englund; Göran Possnert; Ala Aldahan; José María López-Gutiérrez; Uppsala universitet; []
    Nyckelord :Engineering physics; iodine-129; sediment; aerosol; reprocessing; Chernobyl; nuclear weapon; Sellafield; La Hague; accelerator mass spectrometry; AMS; Teknisk fysik;

    Sammanfattning : Since the beginning of the nuclear era, starting during the 1940s, large amount of radioactivity has been released into the environment. This thesis deals with the temporal and spatial distribution of the anthropogenic radioisotope 129I (T1/2= 15.7 Myr) in northern Europe. LÄS MER

  7. 5. Iodine Isotopes and their Species in Surface Water from the North Sea to the Northeastern Atlantic Ocean

    Författare :Peng He; Ala Aldahan; Per Roos; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; iodine isotopes; 129I; 127I; oceans; North Sea; speciation; Atlantic Ocean; English Channel; Celtic Sea; AMS; iodine chemistry; geochemistry; Earth Science with specialization in Environmental Analysis; Geovetenskap med inriktning mot miljöanalys;

    Sammanfattning : Huge amounts of anthropogenic 129I have been and still are released to the environment through liquid and gaseous discharges from the nuclear fuel reprocessing facilities worldwide and in particular the ones in Europe. Most of this 129I signal has been accumulated in the marine environment which plays a major role in the iodine natural pool. LÄS MER