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[en] The authors discuss the production of various charmonium states (J/ψ, χ1, χ2, and ψ') obtained in π-N and pN interactions at 515 GeV/c and also pN interactions at 800 GeV/c in Fermilab experiments E672/E706. The apparatus covers the Feynman-x region 0.1≤x≤0.8. ψ' mesons are observed via their decays to μ+μ- and J/ψπ+π-; χc mesons via their radiative decay to J/ψ + γ. The fraction of J/ψ resulting from ψ' and χc decays is presented, as well as ratio of the production cross sections for χ1 and χ2. The results are compared with recent phenomenological predictions. The authors also describe a search for the Λb in the decay mode J/ψ + Λ0 using the π-N data. No signal was found. Using the E672/E706 measurement of the b bar b cross section from the same data, an upper limit to the product of the Λb production fraction and branching ratio, fΛb·Br(Λb → J/ψΛ0), will be presented
[en] Long-lived artificial radionuclides (137Cs, 90Sr) were studied in a Eucalyptus plantation located in the south-west of Spain. Radionuclide concentrations were determined in different types of samples corresponding to specific forest components (soil, trees, herbs and litter). Depth profile distributions were obtained in two selected core soils. Two layers were separately measured in three other cores. The concentration factor, defined as the ratio between the mean activity concentration in a component and the mean activity concentration in the soil, was calculated for each component. The biomass of different components was estimated in order to evaluate the total density concentration (Bq/ha) of the artificial radionuclides (137Cs, 90Sr) in the Eucalyptus plantation. The transfer of the radionuclides between the different forest components can be inferred from the results. Additionally, other naturally occurring radionuclides (40K, 226Ra, 228Ra, 228Ac) were determined for comparison. Transport of radionuclides from forest to a nearby pulp mill is also discussed
[en] The fluxes and concentrations of 90Sr and 137Cs have been studied in an alkaline pulp mill located in the South of Spain. Both radionuclides can be utilized to trace the production process and to optimize the processes involved. (author)
[en] The present study was conducted to characterize the raw materials (ilmenite and slag), waste (red gypsum) and several co-products (sulphate monohydrate and sulphate heptahydrated) form the titanium dioxide industry in relation to their elemental composition (major, minor and trace elements), granulometry, mineralogy, microscopic morphology, physical composition and radioactive content in order to apply this knowledge in the valorization of the co-products in the fields such a as construction, civil engineering, etc. In particular, the main properties of cements produced with different proportions of red gypsum were studied, and the obtained improvements, in relation to Ordinary Portland Cements (OPC) were evaluated. It was also demonstrated that the levels of pollutants and the radioactive content in the produced RG cements, remain within the regulated safety limits. (Author). 38 refs.
[en] Eucalyptus forests can be considered as the main source of raw material for the pulp industry of Spain. This environment was selected for a radioactivity study because natural and artificial radionuclides can be transferred into the pulp mills, associated with raw material, wood and barks, where they are concentrated by industrial processes, becoming a cause of doses. Radionuclide concentration of natural radionuclides (238U,234U, 228Th, 230Th, 232Th) were determined by alpha- and gamma-spectrometry. Well-established radiochemical procedures were applied to environmental samples in order to isolate these radionuclides. A comparison between 228Th activity, determined by gamma-spectrometry, and 232Th activity, determined by alpha-spectrometry, was used as quality control parameter for analyses. The concentration factors were finally evaluated from experimental data.
[en] The determination of 90Sr in environmental samples can be done by using a gas-flow proportional counter (β-counting) or a liquid-scintillation spectrometer (Cherenkov counting). In this work, we present the factor of merit (FOM) and the minimum detectable activity (MDA) for both the counters. Quantitative relationships are proposed for FOM and MDA determination
[en] The estuary formed by the Tinto and Odiel rivers is an ecosystem of great interest because it is seriously affected by the acid mine drainage (AMD) produced by the high mining activity in the watersheds of these rivers, generating in their waters an extremely low pH (2.5- 3.5), and consequently high concentrations of heavy metals and natural radionuclides in dissolution. Secondly, in their estuary there is a large chemical industrial complex, and in particular two phosphoric acid production plants, which use a sedimentary phosphate rock from Morocco as raw material containing at approximately 1.5 Bq/g of U-series radionuclides, which produce annually about 2.5-3 millions of tonnes of a byproduct, called phosphogypsum (PG). PG contains high concentrations of some U-series radionuclides as 226Ra (650 Bq/kg), 210Pb-210Po (600 Bq/kg) or 230Th (450 Bq/kg). Seventeen sampling stations along the end of these rivers and this estuary were selected to study the behaviour of U-series radionuclides in the recent surface sediments and its waters. The most relevant results show a non-conservative behaviour of Uisotopes, precipitating in the zone where large pH changes (3-5) are produced. This behaviour is different from the majority of typical estuaries where only salinity changes are produced, and therefore, a conservative behaviour of uranium is observed. (author)
[en] In this paper a simple, rapid and general method for γ-ray efficiency calibration of Ge detectors for environmental samples is presented. This method is based on the use of an active natural solid sample with several γ-emissions (in our case, 226Ra) as the calibrating matrix for determining the full energy peak efficiency (FEPE) εc vs γ-emission energy Eγ and the sample height h in a counting cylindrical geometry. The 226Ra activity concentration is determined by α-particle spectrometry, a method that has previously been validated
[en] Tinto and Odiel rivers (SW of Spain) is an ecosystem of great interest that is seriously affected by acid mine drainage (AMD) from long-term mining activities (pH < 3). Additionally, a large industrial complex is located in the surroundings of this estuary and Huelva town, which includes two phosphate rock processing plants that produce about 3 millions of tons per year of a byproduct called phosphogypsum (PG) containing high U-series radionuclides concentrations. For these reasons, the estuary of Huelva is one of the most heavy metals and radionuclides polluted estuarine systems in Europe with extremely low pH.