Glavna kontrola u pravu Srbije u periodu do završetka drugog svetskog rata

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The occurence of opaline matter in hydrothermally altered diabase, Debelo brdo, Povlen mountain area

In this paper it is described the occurence of glassy opaline matter lining hydrothermal vent discovered in altered diabase. These diabase rocks represent tectonically emplaced extrusive igneous body within the volcanic-sedimentary ophiolitic assemblage so called diabase-chert formation. At the microscopic scale, an altered mass of diabase is composed of distinct domains of the wavy and reticular fibrous carbonates interlocking the interstitial patches of the amorphous to locally recrystalised opaline matter. It was observed that the opaline matter lined the altered mass as well, and that it occurs either in the form of boitroidal aggregates or as the alternating colorless and translucent milky white band

Mineralogical Characterization of Raw Clay from Rujište (Serbia) Used in Traditional Pottery Manufacture

The pottery produced from the Rujište deposit in Serbia has been protected under the guidance of UNESCO and the Sector for Intangible Cultural Heritage of Serbia since 2019. A study was conducted to evaluate the mineralogical characteristics of the raw clay from this deposit. This study used various techniques, such as X-ray diffraction (XRD), infrared (IR) spectroscopy, X-ray fluorescence (XRF), and differential thermal analysis (DTA) to characterize the clay. This study found that the clay contained mostly clay minerals (56.3%–41.9%), with illite, smectite, and chlorite as the predominant phases. Other phases identified were quartz, feldspars, carbonates, and iron-bearing minerals (43.8%–58.1%). The chemical analyses revealed a high abundance of silica (>52 wt.%) and alumina (~16 wt.%), with Fe2O3 (~6 wt.%), K2O (~2.8 wt.%), and a similar content of MgO as the main constituents. The physical features that were investigated included the granulometry (clay: ~31%–44%, silt: ~ 26%–23%, and sand: ~ 42%–32%), specific surface area (97 to 107 m2 g−1), cation exchange capacity (12.5–13.7 mmol 100 g−1), and color (yellowish to moderate brown). The preliminary results suggest that most of the raw clay from the Rujište deposit might be suitable for use in traditional pottery manufacture

Actual contamination of the Danube and Sava Rivers at Belgrade (2013)

This study was focussed on a comprehensive investigation on the state of pollution of the Danube and Sava Rivers in the region of Belgrade. Different complementary analytical approaches were employed covering both i) organic contaminants in the river water by target analyses of hormones and neonicotinoids as well as non-target screening analyses and ii) heavy metals in the sediments. Finally, some common water quality parameters were analysed. The overall state of pollution is on a moderate level. Bulk parameters did not reveal any unusual observations. Moreover, quantification of preselected organic contaminants did not indicate to elevated pollution. More significant contaminations were registered for chromium, nickel, zinc and partially copper in sediments with values above the target values according to Serbian regulations. Lastly, non-target screening analysis revealed a wider spectrum of organic contaminants comprising pharmaceuticals, technical additives, personal care products and pesticides. The study presented a comprehensive view on the state of pollution of the Sava and Danube Rivers and is the base for setting up further monitoring programs. As a superior outcome, it was illustrated how different chemical analyses can result in different assessments of the river quality. A comparison of target and non-target analyses pointed to potential misinterpretation of the real state of pollution

Synthesis and structural characterization of new cesium and potassium rare-earth silicates

Predmet i ciljevi naučnog istraživanja ove doktorske disertacije su sinteza i strukturna karakterizacija novih cezijumskih i kalijumskih silikata sa elementima retkih zemalja. Istraživanja su izvedena u okviru sistema SiO2–REE2O3–XF, gde REE predstavlja trovalentni katjon elementa retkih zemalja (Sc, Y, Sm, Eu, Gd, Ho, Er, Tm, Yb, Lu), dok X predstavlja jednovalentni katjon alkalnih metala (K, Cs). Rad na disertaciji bio je fokusiran na sintezu monokristala, određivanje kristalnih struktura, kao i na kristalografsko i kristalohemijsko ispitivanje sintetisanih monokristala. Monokristali su sintetisani metodom rasta kristala iz visokotemperaturnih rastvora uz upotrebu fluksa. Kristalne strukture rešene su pomoću rendgenske difrakcije na monokristalu. Kvalitet monokristala proveravan je pomoću stereomikroskopa, dok je polarizacioni mikroskop korišten za posmatranje optičkih osobina. Rendgenska difrakcija na polikristalnom materijalu služila je za proveru faznog sastava. Skenirajuća elektronska mikroskopija (SEM) dopunjena sa energetsko-disperzivnom spektroskopijom (EDS) korištena je za određivanje morfoloških karakteristika i za semikvantitativno određivanje hemijskog sastava. U toku izrade disertacije određeno je osam (8) kristalnih struktura. Kristalna struktura Cs2ErSi6O14F predstavlja novi strukturni tip, dok je struktura Cs3ScSi6O15 prvi put rešena kao modulisana struktura. Jedinjenja Cs2HoSi4O10F, Cs2ErSi4O10F i Cs2TmSi4O10F izostrukturna su sa Cs2YSi4O10F. Za jedinjenje K3EuSi2O7 određena je kristalna struktura u prostornoj grupi P63/mcm i pokazalo se da je izostrukturno sa K3REESi2O7 (REE = Nd, Sm, Gd–Yb, Y, Y0,9Dy0,1, Sm i Er). Jedinjenja K3ErSi2O7 i K3YbSi2O7 kristališu u prostornoj grupi P63/mmc i izostrukturna su sa jedinjenjima K3REESi2O7 (REE = Lu, Sc i Y).The subject and goals of the scientific research of this doctoral dissertation are the synthesis and structural characterization of new cesium and potassium rare-earth silicates. The investigation was carried out in the SiO2–REE2O3–XF system, where REE represents a trivalent cation of a rare-earth element (Sc, Y, Sm, Eu, Gd, Ho, Er, Tm, Yb, Lu), while X represents a monovalent cation of alkali metals (K, Cs). Dissertation work was focused on the synthesis of single crystals, the determination of crystal structures, as well as on crystallographic and crystallochemical investigation. Single crystals were synthesized by high-temperature flux crystal growth. The crystal structures were solved using single-crystal X-ray diffraction. The quality of single crystals was inspected using a stereomicroscope, while a polarizing microscope was used to observe the basic optical properties. The phase composition was tested using powder X-ray diffraction. Scanning electron microscopy (SEM) coupled with energy-dispersive spectroscopy (EDS) was used for morphological and chemical characterization. Eight (8) crystal structures were determined during the work on the dissertation. The crystal structure of Cs2ErSi6O14F represents a new structural type, while the crystal structure of Cs3ScSi6O15 was solved for the first time as a modulated structure. Compounds Cs2HoSi4O10F, Cs2ErSi4O10F and Cs2TmSi4O10F are isostructural with Cs2YSi4O10F. For the compound K3EuSi2O7, the crystal structure in the space group P63/mcm was determined and it was shown to be isostructural with K3REESi2O7 (REE = Nd, Sm, Gd–Yb, Y, Y0.9Dy0.1, Sm and Er). Compounds K3ErSi2O7 and K3YbSi2O7 crystallize in the space group P63/mmc and they are isostructural with K3REESi2O7 (REE = Lu, Sc and Y) compounds

Synthesis and structural characterization of new cesium and potassium rare-earth silicates

Predmet i ciljevi naučnog istraživanja ove doktorske disertacije su sinteza i strukturna karakterizacija novih cezijumskih i kalijumskih silikata sa elementima retkih zemalja. Istraživanja su izvedena u okviru sistema SiO2–REE2O3–XF, gde REE predstavlja trovalentni katjon elementa retkih zemalja (Sc, Y, Sm, Eu, Gd, Ho, Er, Tm, Yb, Lu), dok X predstavlja jednovalentni katjon alkalnih metala (K, Cs). Rad na disertaciji bio je fokusiran na sintezu monokristala, određivanje kristalnih struktura, kao i na kristalografsko i kristalohemijsko ispitivanje sintetisanih monokristala. Monokristali su sintetisani metodom rasta kristala iz visokotemperaturnih rastvora uz upotrebu fluksa. Kristalne strukture rešene su pomoću rendgenske difrakcije na monokristalu. Kvalitet monokristala proveravan je pomoću stereomikroskopa, dok je polarizacioni mikroskop korišten za posmatranje optičkih osobina. Rendgenska difrakcija na polikristalnom materijalu služila je za proveru faznog sastava. Skenirajuća elektronska mikroskopija (SEM) dopunjena sa energetsko-disperzivnom spektroskopijom (EDS) korištena je za određivanje morfoloških karakteristika i za semikvantitativno određivanje hemijskog sastava. U toku izrade disertacije određeno je osam (8) kristalnih struktura. Kristalna struktura Cs2ErSi6O14F predstavlja novi strukturni tip, dok je struktura Cs3ScSi6O15 prvi put rešena kao modulisana struktura. Jedinjenja Cs2HoSi4O10F, Cs2ErSi4O10F i Cs2TmSi4O10F izostrukturna su sa Cs2YSi4O10F. Za jedinjenje K3EuSi2O7 određena je kristalna struktura u prostornoj grupi P63/mcm i pokazalo se da je izostrukturno sa K3REESi2O7 (REE = Nd, Sm, Gd–Yb, Y, Y0,9Dy0,1, Sm i Er). Jedinjenja K3ErSi2O7 i K3YbSi2O7 kristališu u prostornoj grupi P63/mmc i izostrukturna su sa jedinjenjima K3REESi2O7 (REE = Lu, Sc i Y).The subject and goals of the scientific research of this doctoral dissertation are the synthesis and structural characterization of new cesium and potassium rare-earth silicates. The investigation was carried out in the SiO2–REE2O3–XF system, where REE represents a trivalent cation of a rare-earth element (Sc, Y, Sm, Eu, Gd, Ho, Er, Tm, Yb, Lu), while X represents a monovalent cation of alkali metals (K, Cs). Dissertation work was focused on the synthesis of single crystals, the determination of crystal structures, as well as on crystallographic and crystallochemical investigation. Single crystals were synthesized by high-temperature flux crystal growth. The crystal structures were solved using single-crystal X-ray diffraction. The quality of single crystals was inspected using a stereomicroscope, while a polarizing microscope was used to observe the basic optical properties. The phase composition was tested using powder X-ray diffraction. Scanning electron microscopy (SEM) coupled with energy-dispersive spectroscopy (EDS) was used for morphological and chemical characterization. Eight (8) crystal structures were determined during the work on the dissertation. The crystal structure of Cs2ErSi6O14F represents a new structural type, while the crystal structure of Cs3ScSi6O15 was solved for the first time as a modulated structure. Compounds Cs2HoSi4O10F, Cs2ErSi4O10F and Cs2TmSi4O10F are isostructural with Cs2YSi4O10F. For the compound K3EuSi2O7, the crystal structure in the space group P63/mcm was determined and it was shown to be isostructural with K3REESi2O7 (REE = Nd, Sm, Gd–Yb, Y, Y0.9Dy0.1, Sm and Er). Compounds K3ErSi2O7 and K3YbSi2O7 crystallize in the space group P63/mmc and they are isostructural with K3REESi2O7 (REE = Lu, Sc and Y) compounds

Mineralogical study of clays from Dobrodo, Serbia, for use in ceramics

This study focuses on the mineralogical characterization of four raw clay samples from Dobrodo deposit, Serbia. Several analytical methods were applied to determine the chemical and mineralogical composition, morphology and physical properties (colour, plasticity, specific surface area, particle size and cation-exchange capacity) of the clay samples. Kaolinite, smectite and illite are the predominant phases in all of the samples studied that contain between 60.2 and 87.1 wt.% of clay. Quartz, feldspars, paragonite and Ti- and Fe-bearing phases were also identified. The relatively high SiO2/Al2O3 mass ratio indicates abundant quartz. The cation-exchange capacity of the samples varied between low and moderately charged clay minerals (12-52 mmol 100 g(-1)) with specific surface area values ranging from 94 to 410 m(2) g(-1). The plasticity index values (11-23%) suggest low to moderate plasticity. Preliminary results show that most of the raw clay from Dobrodo deposit might be suitable for use in ceramic applications

Correlation of structural defects in the ascending aortic wall to ultrasound parameters: benefits for decision-making process in aortic valve surgery

Abstract Background Histopathological changes in the ascending aorta wall in patients with severe tricuspid aortic valve (TAV) stenosis were graded and correlated to echocardiographic parameters. Objective was to associate threshold echocardiographic values with structural defects in the ascending aorta providing a tool to improve decision-making process in cases when simultaneous aortic valve replacement (AVR) and ascending aorta replacement is considered. Methods Biopsies from 108 TAV stenosis patients subjected to AVR were graded into three grades according to severity of aortic wall changes. Echocardiographic parameters obtained preoperatively and correlated to grade, age, gender and risk factors, were diameters of ventriculo-aortic junction (AA), sinus Valsalva (SV), sinotubular junction (STJ), the largest diameter of the visualized ascending aorta (AscA) as well as indexes: sinus Valsalva (SVI), sinotubular junction (STJI), AscA/AA and STJ/AA. Results Two echocardiographic parameters portrayed grades with statistical significance: STJ (F = 5.417; p = 0.006 (p  3.3 cm, while Grade 3 is identified in patients with values of AscA > 3.5 cm, STJ > 2.9 cm and STJI > 1. Conclusions Hemodynamic stress induced by TAV stenosis leads to elastic lamellae disruption in the aortic wall. Those changes could be graded and correlated with echocardiographic parameters of the aortic root and ascending aorta, providing a tool for decision to replace ascending aorta concomitantly with AVR

Physicochemical, Antioxidant and Sensory Properties of Peach Wine Made from Redhaven Cultivar

Physicochemical, sensory, and health-related characteristics of peach wine produced from Redhaven variety and selected white wines produced from various grape varieties were determined and compared. The alcohol content, titratable acidity, and total extract of peach wine was significantly lower compared with that of white wines, while its pH value was higher. The content of total phenolics (TPC) and flavonoids (TFC) of peach wine (402.53 mg/L GAE and 332.67 mg CAE/L, respectively) have been found significantly higher in comparison with that of white wines (TPC range 243.67-319.00 mg/L GAE, TFC range 129.67-175.17 mg CAE/L). The main phenolic compounds found in peach wine were chlorogenic acid, caffeic acid, and catechin (3.59, 0.87, and 0.60 mg/L, respectively). Antioxidant capacities were strongly correlated with total phenolics with correlation coefficients over 0.99. The highest antioxidant capacity was ascribed to peach wine. The results of sensory analysis indicated that the peach wine was very well accepted by the regular consumers of wine and can be a very interesting product in the market