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  • Author or Editor: C. Triulzi x
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Abstract  

Beta detection efficiency curves are reported for some radionuclides of interest (40K,90Y,90Sr+90Y,137Cs,144Ce+144Pr,147Pm,155Eu and204Tl) contained in sources of a suitable material and having a superficial density ranging from 3 to 110 mg/cm2; the curves were experimentally drawn by measuring the reference sources in different geometries by means of three GM window detectors (one of them with low background) and of a 2π flow proportional counter. These curves have been used for several years in the Radiochemistry Service Laboratories to determine radionuclides in sources of different thickness obtained by specific radiochemical separations from various environmental samples.

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Abstract  

During the last 14 years the Radioecology Laboratory of Parma University and the General Chemistry Institute of Urbino University collaborated on a radioecological programme having the aim to observe the evolution of antropogenic radioactivity in Antarctica in the period 1987-2001. The artificial radionuclides considered were 90Sr, 137Cs, 239+240Pu,238Pu and 241Am. The contamination seems to be higher in the continental environment rather than in the marine one. Mosses, algae and lichens showed the highest values for all radionuclides analyzed. The results prove that the Antarctic continent is interested by radioactive pollution. As far as 137Cs is concerned, a progressive decrease was observed.

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Abstract  

During the last ten years, the Italian Universities of Parma and Urbino collaborated on a special radioecological program having the aim to study the levels and the distribution of long-lived radionuclides in different marine and terrestrial matrixes. This paper summarizes the results concerning the concentrations of 239+240Pu and 238Pu, 241Am and 137Cs in sediments collected in the Ligurian and South Tyrrhenian Seas (Rapallo Harbour, Vado Ligure Canyon, Eolie Islands). Superficial sediments and sediment cores were collected. For cores the vertical distribution was calculated and the sedimentation rate obtained. 137Cs was determined directly by gamma-spectrometry, while 239+240Pu, 238Pu and 241Am were separated by extraction chromatography, electroplating and determined by alpha-spectrometry.

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