2,804 research outputs found

    Dates, Caries, and Early Tooth Loss During the Iron Age of Oman

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    Eine Ernährung aus fermentierbaren Kohlenhydraten ist bekannterweise hoch kariogen, besonders im Falle von zuckerhaltigem Essen wie zum Beispiel Datteln. Diese Ernährung ist bei der späteisenzeitlichen Samad-zeitlichen Bevölkerung Omans zu beobachten. 32 Erwachsene und 5 Jugendliche dienten für diese Studie als Erhebung. Vorzeitiger Zahnverlust war in allen Fällen nachweisbar

    Re-measurement of the 33{}^{33}S(α\alpha,p)36{}^{36}Cl cross section for Early solar system enrichment

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    Short-lived radionuclides (SLRs) with half-lives less than 100 Myr are known to have existed around the time of the formation of the solar system around 4.5 billion years ago. Understanding the production sources for SLRs is important for improving our understanding of processes taking place just after solar system formation as well as their timescales. Early solar system models rely heavily on calculations from nuclear theory due to a lack of experimental data for the nuclear reactions taking place. In 2013, Bowers et al. measured 36{}^{36}Cl production cross sections via the 33{}^{33}S(α\alpha,p) reaction and reported cross sections that were systematically higher than predicted by Hauser-Feshbach codes. Soon after, a paper by Peter Mohr highlighted the challenges the new data would pose to current nuclear theory if verified. The 33{}^{33}S(α\alpha,p)36{}^{36}Cl reaction was re-measured at 5 energies between 0.78 MeV/A and 1.52 MeV/A, in the same range as measured by Bowers et al., and found systematically lower cross sections than originally reported, with the new results in good agreement with the Hauser-Feshbach code TALYS. Loss of Cl carrier in chemical extraction and errors in determination of reaction energy ranges are both possible explanations for artificially inflated cross sections measured in the previous work
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