102 research outputs found

    Comparison of extraction agents for metal determination in sediments from artificial lakes and rivers in Serbia

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    The purpose of this paper was to investigate the effectiveness of three different extraction agents for the extraction of 25 elements from sediment samples collected from 4 artificial lakes and 12 rivers in Serbia (33 samples in total). The extraction efficiency of the agents was evaluated by its ability to extract the highest quantity of the elements. For that purpose, three acids (1M HCl, 2M HNO3 and 0.43M CH3COOH) have been used. Inductively coupled plasma atomic emission spectrometry (ICP-OES) was used for quantitative determination of following elements: Al, As, B, Ba, Be, Bi, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Li, Mg, Mn, Ni, Na, Pb, Sb, Se, Sr, V, and Zn. The extraction with 1M HCl has shown the best results for the majority of investigated elements (especially Sr, Mn and Ca). Antimony (Sb) was detected only after extraction with 0.43M CH3COOOH, while selenium (Se) could not be detected when 2M HNO3 was applied as extraction agents. The present study could be very useful for choosing a suitable method for specific elements and also can be helpful in the evaluation of the contaminants in freshwater sediments in Serbia. This might contribute to environmental risk assessment of the present elements

    To Professor Petar Pfendt, In calidum, et plurium retributivus memoriae: FTIR-ATR analysis of post stamps of the Principality of Serbia issued in 1866 and 1868 and their forgeries

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    In order to further define the potential use of FTIR-ATR spectroscopy, as a non-destructive and reliable technique, for the analysis of the characteristics of post stamps, certified originals of the Principality of Serbia stamps (“Prince Michael issues”) issued in 1866 and 1868 as well as their forgeries were ana­lyzed. Spectra enabling the comparison of the paper, dye and glue of stamps of so-called “Vienna issues”, having denominations of 10 (orange-yellow), 20 (pink) and 40 para (blue) and “Belgrade issues” (1 para-green and 2 para-reddish brown), as well as 24 expert-certified forgeries, were taken. It was shown that the applied technology was, in most of the cases, a fast and suitable technique for establishing clear differences between the spectral characteristics of the paper and dye used for the original stamps, and forgeries that were most probably made decades after the printing of the genuine stamps. The differences between print­ings of the same issues of the genuine stamps were also elaborated. It is pro­posed, for the first time in philatelic history, the possibility that “Vienna issues” stamps may have been printed on two different papers, and, having in mind the technology of printing in the 19th century, potentially, not even at the same time or in the same printing house

    Evaluation of potentially toxic element contamination in the riparian zone of the River Sava

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    Contaminated sediments transported onto the river terrace during high water events can contribute significant quantities of potentially toxic elements to riparian soils. Seven trace elements (As, Cd, Cr, Cu, Ni, Pb and Zn) were analysed in the river sediment and riparian soil of the River Sava and their spatial distribution, potential toxicity and ecological risk levels were evaluated. The results showed that levels of all the trace metals were enriched to varying extents in both the sediment (As, Cr, Ni, and Pb) and soil (Ni) when compared to reference levels for sediments and European soils. Mean concentrations of trace metals in sediment and soil, apart from Pb, increased downstream in the River Sava. The similar increasing trend of these elements in sediment and soil may be explained by their increased load due to anthropogenic pressures (As, Cr, Ni, Pb and Zn in sediment and the significant accumulation of Ni in soil) and frequent periodic flooding (As, Cd, Cr, Cu, Ni and Zn in sediment and Cd in soil are influenced by both high water events and natural factors such as the geological substrate), particularly in lowland regions. In this study, soluble As, Cd, Cr, Cu and Ni fractions in sediment and soil LT 10% indicated their low mobility. The exceptions were readily soluble Pb and Zn in the sediment and soil at some sampling sites. In the lower reaches, levels of Pb in sediment was indicative of a medium environmental hazard, while there was a high environmental hazard in the upper reaches with the average Pb content in sediment higher than the PEL. Pollution factors for Pb in soil indicated a medium environmental hazard in the upper and middle reaches and a high environmental hazard at some sites in the lower stretches of the Sava River, although total Pb content in soil was within the range proposed for European soils

    Contamination, risk, and source apportionment of potentially toxic microelements in river sediments and soil after extreme flooding in the Kolubara River catchment in Western Serbia

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    Climate change is contributing to an increase in extreme weather events. This results in a higher river flooding risk, causing a series of environmental disturbances, including potential contamination of agricultural soil. In Serbia, the catastrophic floods of 2014 affected six river basins, including the Kolubara River Basin, as one of the larger sub-catchments of the large regional Sava River Basin, which is characterized by large areas under agricultural cultures, various geological substrates, and different types of industrial pollution. The main aim of this study was to establish the sources of potentially toxic elements in soil and flood sediments and the effect of the flood on their concentrations. Field sampling was performed immediately after water had receded from the flooded area in May 2014. In total, 36 soil samples and 28 flood sediment samples were collected. After acid digestion (HNO3), concentrations of the most frequent potentially toxic elements (PTE) in agricultural production (As, Cd, Cr, Cu, Ni, Pb, Zn) and Co which are closely related to the geological characteristics of river catchments, were analyzed. The origin, source, and interrelations of microelements, as well as BACKGROUND: values of the PTE of the river catchment, the pollution index (Pi), enrichment factor (Ef), and geological index (Igeo), were determined, using statistical methods such as Pearson correlations, principal component analysis (PCA), and multiple linear regression (MLRA). The content of the hot acid-extractable forms of the elements, PCA, and MLRA revealed a heavy geological influence on microelement content, especially on Ni, Cr, and Co, while an anthropogenic influence was observed for Cu, Zn, and Cd content. This mixed impact was primarily related to mines and their impact on As and Pb content. The pseudo-total concentrations of all the analyzed elements did not prove to be a danger in the catchment area, except for Cu in some samples, indicating point-source pollution, and Ni, whose pseudo-total content could be a limiting factor in agricultural production. For the Ef, the Ni content in 59% soil and 68% flood sediment samples is classified into influence classes. The similar pseudo-total contents of the elements studied in soil samples and flood sediment and their origin indicate that the long-term soil formation process is subject to periodic flooding in the Kolubara River Basin without any significant changes taking place. This implies that floods are not an endangering factor in terms of the contamination of soil by potentially toxic elements in the explored area

    Predictors of enhancing human physical attractiveness: Data from 93 countries

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    People across the world and throughout history have gone to great lengths to enhance their physical appearance. Evolutionary psychologists and ethologists have largely attempted to explain this phenomenon via mating preferences and strategies. Here, we test one of the most popular evolutionary hypotheses for beauty-enhancing behaviors, drawn from mating market and parasite stress perspectives, in a large cross-cultural sample. We also test hypotheses drawn from other influential and non-mutually exclusive theoretical frameworks, from biosocial role theory to a cultural media perspective. Survey data from 93,158 human participants across 93 countries provide evidence that behaviors such as applying makeup or using other cosmetics, hair grooming, clothing style, caring for body hygiene, and exercising or following a specific diet for the specific purpose of improving ones physical attractiveness, are universal. Indeed, 99% of participants reported spending >10 min a day performing beauty-enhancing behaviors. The results largely support evolutionary hypotheses: more time was spent enhancing beauty by women (almost 4 h a day, on average) than by men (3.6 h a day), by the youngest participants (and contrary to predictions, also the oldest), by those with a relatively more severe history of infectious diseases, and by participants currently dating compared to those in established relationships. The strongest predictor of attractiveness-enhancing behaviors was social media usage. Other predictors, in order of effect size, included adhering to traditional gender roles, residing in countries with less gender equality, considering oneself as highly attractive or, conversely, highly unattractive, TV watching time, higher socioeconomic status, right-wing political beliefs, a lower level of education, and personal individualistic attitudes. This study provides novel insight into universal beauty-enhancing behaviors by unifying evolutionary theory with several other complementary perspectives
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