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21.
Isotopic and elemental characterisation of Slovenian apple juice according to geographical origin: Preliminary results : /
Karmen Bizjak Bat, Klemen Eler, Darja Mazej, Branka Mozetič Vodopivec, Ines Mulič, Peter Kump, Nives Ogrinc, 2016, original scientific article

Abstract: This study examined the applicability of stable isotope and multi-element data for determining the geographical origin of fresh apple juices. Samples included three apple cultivars (Idared, Golden Delicious and Topaz) harvested in 2011 and 2012 from five different geographical regions of Slovenia. Regional discrimination of the juice samples was most successful when using linear discriminant analysis (LDA) and taking into account the following parameters: d2H and d18O content of juice water; d15N and d13C content of the pulp, (D/H)I and (D/H)II in ethanol and the concentration of S, Cl, Fe, Cu, Zn and Sr. Overall prediction ability was 83.9%. The factors that best distinguished the different types of cultivar were the d2H and d18O content of fruit juice water; the d13C and (D/H)I content of ethanol; and the concentration of S, Mg, K, Cu, and Ti. Prediction ability, taking into account all ten parameters, was 75.8%.
Keywords: Apple juice, Stable isotopes, Elemental content, Geographical origin, Slovenia
Published in RUNG: 15.02.2016; Views: 5935; Downloads: 0
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22.
Radioactive isotopes in ground waters of Slovenia
Katarina Kovačič, 2015, doctoral dissertation

Abstract: Within the duration of three projects (J7-0363, L1-0437, L1-4280), in the period from 2008 to 2013, measurements of tritium (3H), 40K and γ-ray emitters of uranium (238U, 226Ra and 210Pb) and thorium (228Ra and 228Th) decay series in groundwaters of Slovenia were carried out. Tritium was also measured in precipitation at selected locations. Groundwater sampling sites were selected in order to cover the most representative lithological units that are found in Slovenia and were at the same time evenly distributed throughout the country. In total, 281 samples were measured from 120 different locations. Measurements in the period 2009-2013 have shown that tritium concentrations in precipitation in Ljubljana are for about 30% lower compared to those in Vienna, however they are in line with seasonal fluctuations observed in Vienna. This was an important information in the process of the reconstruction of past tritium concentrations in precipitation in Ljubljana (tritium curve) for the missing period between 1953 and 1981. Tritium curve represents the input data when determining the average age of water. In determining the influence of various parameters on the final interpretation of the groundwater age it has been found that the greatest uncertainty contribute the measurements of the tritium curve and the measurements of tritium in groundwater samples. Also, the interaction of other factors (continental effect, rainfall regime, infiltration) and the lack of knowledge of them may have a major impact on the misinterpretation of groundwater age. Based on tritium concentration, groundwaters were divided into 4 major categories, into groundwaters that are older than 100 years (tritium concentration was below the detection limit), groundwaters, where the older component prevails (concentration of tritium was between 0 and 2.5 TU), groundwaters with the age between 30 and 60 years (the concentration of tritium was on average 8 TU) and recent groundwaters with age up to 15 years (tritium concentration of about 6 TU). The natural background of γ-ray emitters was determined for each lithological unit. The most represented radionuclide was 40K with concentrations always above the detection limit. A dependency of 40K concentrations on nitrate was observed, especially in the recharge areas, where limestone prevailed. Other γ-ray emitters revealed some dependence on nitrate concentration, especially both radium isotopes (226Ra and 228Ra). The concentration of 210Pb in groundwaters is mainly due to the connection with the surface and consequently with atmospheric 210Pb. The highest concentrations of 238U and 228Ra were measured in groundwaters from recharge areas in clastic rocks with a clay component. In contrast to the expected, concentrations for all γ-ray emitters (except 210Pb) were the lowest or even not detectable, in groundwaters from recharge areas in igneous and metamorphic rocks. Among γ-ray emitters and categorization based on tritium concentrations, elevated concentrations of 238U were observed in groundwaters with prevailing older component. Elevated concentrations of 40K were also observed in them. The largest scattering of 210Pb and 40K concentrations was observed in recent waters, which indicates a connection with the surface and application of fertilizers.
Keywords: Groundwaters, Slovenia, tritium input curve, natural gamma-ray emitters background.
Published in RUNG: 05.10.2015; Views: 6250; Downloads: 209
.pdf Full text (8,62 MB)

23.
Assessing and mapping drought vulnerability in agricultural systems
Maja Slejko, Gregor Gregorič, Klemen Bergant, Samo Stanič, 2010, published scientific conference contribution abstract

Keywords: suša, ocena ranljivosti, kmetijstvo, GIS, Slovenia
Published in RUNG: 15.10.2013; Views: 11414; Downloads: 154
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