Search

According to the Serbian official soil classification system, Rendzina is a soil type with an A-AC-C-R profile, developed on parent rock containing more than 20% of calcareous material (except soils with an A-R profile on hard pure limestone or dolomite). Previous investigations have shown that 29 Rendzina soil profiles from Serbia belong to the reference soil groups (RSGs) of Leptosols, Regosols and Phaeozems according to the World Reference Base for Soil Resources (WRB 2015). The present study addresses the correlations among three WRB RSGs in terms of soil texture, mean weight diameter (MWD), total N content, and humus fractional composition using Principal Component Analysis (PCA). The objective is to better understand the mutual relationship between the classification soil units used in Serbia and the international WRB system. The results show that PCA cannot unequivocally distinguish between these three RSGs. Leptosols and Regosols are highly incoherent groups while the group of Phaeozems is highly coherent, leading to the conclusion that the physical and chemical properties of the soil profiles of Phaoeozems are specific. It is obvious that soil depth and color, which are the overriding factors in the differentiation of Rendzina soils into three WRB RSGs, had no significant effect on these properties. The results further show that soil properties such as texture, MWD, humus fractional composition, etc. cannot be used to correlate Rendzina soils from Serbia with WRB. Instead, careful correlation of individual soil profiles is needed based on quantitative soil data analysis as required by WRB.

Part of Cu post flotation tailings of Serbia ZiJin Bor Copper, Serbia, was reclaimed by restoration of top soil with arable soils, and revegetation in 1991. Humic acids isolated from these Technosols were investigated to find out if their properties underwent any changes since reclamation. Two groups of control samples were used. Elemental composition (CHNS analysis) falls within the range of average soil humic acids. Humic acids belong to the type B pointing out to its lower humification degree (UV–Vis). Relative abundances of functional groups are ranged as follows: polysaccharide C ≥aromatic C > carboxyl C > OH group > aliphatic C. Aromaticity indexes are low, 1.88– 3.25 (ATR-FTIR). Basic units at pH 10 are in the 11.7–26.8 nm range. Pronounced reaggregation (1462-–5218 nm) at pH 3 points out to less expressed humic acid sol stability, as well as to increase in aromatic condensation degree (dynamic light scattering). No significant changes have occurred in technosol humic acids since the recultivation, confirming stability of their properties over time (PCA). Nevertheless, humic acids from very strongly acidic Technosols show higher humifycation degree possibly originating from arable soils used in reclamation, but more likely from low soil pH and low litter input, results of unsuccessful reclamation.

This paper presents the optimized technological process for obtaining stable calcium carbonate dispersion (CaCO3) in accordance to the standard prescribed in the paper industry. The reason for using CaCO3 in paper production is their low price when compared to the cellulose fibers and its ability to improve the properties of the final product. However, CaCO3 is alkaline filler that has relatively poor chemical stability that may affect the characteristics of the paper. For this reasons it is necessary to optimize the technology for obtaining a stable dispersion of CaCO3 with particles diameter in range 1 mm

Russian icon painted on wooden panel analyzed in this work is interesting for art historians because there is no precise information in which workshops it was made or who the author was. Similar icons are often found in churches and monasteries in our region. In order to obtain information about materials used for creation of investigated icon two micro-analytical techniques were used: Energy-Dispersive X-Ray Fluorescence spectroscopy (EDXRF) and micro-Raman spectroscopy. Obtained results confirmed presence of following materials: lead-white, vermilion, minium, ultramarine, brown and green earth pigments and silver in combination with yellow organic varnish, which served to an iconographer for gilding. Ground layer was made of calcite. Blue pigment ultramarine was probably used for blue colour as well as for obtaining particulars hues in several parts of the paint layer. This can be important information for further research concerning particular workshop in which the icon was made. Identified materials are typical for Russian iconography of the 19th century. [Projekat Ministarstva nauke Republike Srbije, br. OI 177021 i OI 177012]

Abstract Background Portable energy dispersive X-ray fluorescence (pEDXRF) spectrometry analysis was applied for the characterisation of archaeological ceramic findings from three Neolithic sites in Serbia. Two dimension reduction techniques, principal component analysis (PCA) and scattering matrices-based dimension reduction were used to examine the possible classification of those findings, and to extract the most discriminant features. Results A decision-making procedure is proposed, whose goal is to classify unknown ceramic findings based on their elemental compositions derived by pEDXRF spectrometry. As a major part of decision-making procedure, the possibilities of two dimension reduction methods were tested. Scattering matrices-based dimension reduction was found to be the more efficient method for the purpose. Linear classifiers designed based on the desired output allowed for 7 of 8 unknown samples from the test set to be correctly classified. Conclusions Based on the results, the conclusion is that despite the constraints typical of the applied analytical technique, the elemental composition can be considered as viable information in provenience studies. With a fully-developed procedure, ceramic artefacts can be classified based on their elemental composition and well-known provenance.

Copyright of Chemical Industry / Hemijska Industrija is the property of Association of Chemical Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)