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Упит dcterms_subject_txt:chemical mixture

105 items

  • Application of Expansive Mortars for the Formation of Artificial Screens During Blasting in Urban Areas

    Milanka Negovanović, Lazar Kričak, Stefan Milanović, Nikola Simić, Jelena Majstorović (2024)
    During construction of buildings in urban areas, sometimes there is a need to blast solid rock mass in the immediate vicinity of the surrounding buildings. In that case, the aim is not only to increase the efficiency of blasting, but also to reduce harmful effects of ground vibration induced by blasting. At the same time, it is very important to protect the buildings located in the safe zone from the blast site as well as remaining rock mass around ...
    expansive mortar, artificial screens, pressure, rock breaking, building foundation

  • Structural characterization of traditional pottery produced from local clay, Rujište (Ražanj, Central Serbia), in an effort to preserve its geoheritage

    Maja Milošević, Biljana Đorđević, Alena Zdravković (2021)
    ... of different sizes, which are mostly arranged in a face-to-face pattern. Pseudo-hexagonal mineral layers and kaolinite slabs are present as a mixture. As some of the slabs have rolled and rough edges they may be regarded as illite and/or halloysite. Morphology varies from short tubular, spheroidal ...
    ... (WDS) and a cathodoluminescence detector (CL) were applied to determine the morphology and grain size assessment of minerals as well as their chemical composition. Raw clay, from which investigated sample of pottery was produced, largely falls under Neogene sediments which are extensive in the ...

  • The use of biological markers in determination of origin and type of organic matter in the Tisza river sediments

    Snežana Štrbac, Gordana Gajica, Aleksandra Šajnović, Nebojša Vasić, Ksenija Stojanović, Branimir Jovančićević (2013)
    The objective of the study was to determine the origin and type of organic matter (OM) of the Tisza recent sediments along the distance of 153 km through the territory of Serbia. For this purpose group organic-geochemical parameters and biomarker compositions were used. All samples contain approximately same amount of OM, which was deposited under uniform, slightly reducing conditions. Based on the distribution of n-alkanes, the origin and type of OM could not be precisely estimated. However, n-alkane patterns ...
    sediments, Tisza River, organic matter, biomarkers, oil pollutants
    ... azeotropic mixture of CH2Cl2 and CH3OH and quantified. The bitumen extracts and crude oils were separated into saturated, aromatic and NSO fractions using column chromatography over silica gel. The saturated hydrocarbon fraction was eluted with n-hexane, aromatic hydrocarbons with mixture of n-hexane ...
    ... n-hexane and dichloro- methane (4:1 volume ratio) and the NSO fractions (polar fraction, which contains nitrogen, sulphur, and oxygen compounds) with mixture of dichloromethane and methanol (1:1 volume ratio). The saturated hydrocarbons were analyzed by gas chromatography–mass spectrometry (GC–MS). A ...
    ... river sediments | Snežana Štrbac, Gordana Gajica, Aleksandra Šajnović, Nebojša Vasić, Ksenija Stojanović, Branimir Jovančićević | Journal of Serbian Chemical Society | 2013 | | 10.2298/JSC130614087S http://dr.rgf.bg.ac.rs/s/repo/item/0002360 Дигитални репозиторијум Рударско-геолошког факултета Универзитета ...

  • Kristalografsko proučavanje strukturne desimetrizacije granata grosularsko-andraditske izomorfne serije

    Pavle I. Tančić (2016-09-21)
    U ovoj Doktorskoj disertaciji proučavano je pet različitih zona makroskopski zonarnog grandita sa lokaliteta Meka Presedla (Kopaonik, Srbija). Pomoću hemijske i elektronske analize mikroprobe preračunati su relativno visoko homogeni sastavi zona, t.j.: Grs64±1Adr36±1Sps2 (A), Grs62±1Adr38±1Sps2 (B), Grs59±2Adr40±2Sps2 (C), Grs58±2Adr41±2Sps2 (D) i Grs58±1Adr41±1Sps2 (E). Glavne promene u sastavima izražene formulom: Ca2,93-2,97Mn0,05-0,06Mg0,00-0,01Al1,14-1,26Fe3+0,72-0,83Ti0,00-0,02Si2,97-3,02O12 ukazuju da je jedina značajnija varijacija ustanovljena samo kod Al-Fe3+ raspodela u oktaedarskom položaju. Ovakav hemijski sastav je potvrđen i sa matematičkim proračunima iz IC i Raman analiza. Urađena ...
    Macroscopically zoned grandite, chemical analysis, electron microprobe analysis, Raman, Rietveld, structure, dissymmetrization, space group

  • Distribution of major and trace elements in the Kovin lignite (Serbia)

    Dragana Životić, Olga Cvetković, Predrag Vulić, Ivan Gržetić, Vladimir Simić, Konstantin Ilijević, Biljana Dojčinović, Suzana Erić, Bogdan Radić, Sanja Stojadinović, Snežana Trifunović (2019)
    geochemical and mineralogical study was performed on lignite samples from the Upper Miocene Kovin deposit, hosting three coal seams. The Kovin lignite is characterized by high moisture content, medium to high ash yield, medium to high sulphur content and a relatively low gross and net calorific value. The mineralogical composition, and major and trace element contents were determined by X-ray diffraction, scanning electron microscopy with energy dispersive Xray spectroscopy (SEM-EDS) analyses, and inductively coupled plasma optical emission spectrometry (ICP-OES). ...
    General Earth and Planetary Sciences, General Environmental Science
    ... 56/603 88.60–88.80 MMiC MC – Stratified matrix coal (weakly gelified); XC – Xylite-rich coal; MXC – Mixture of matrix and xylite-rich coal and Mixture of xylite-rich and matrix coal; MMiC – Mixture of matrix and mineral-rich coal; MiC – Mineral-rich coal (TAYLOR et al., 1998). SUPPLEMENTARY MATERIAL ...
    ... Comparative chemical and mineral charac­ terization of some Bulgarian coals.– Fuel Processing Technology, 55, 55–69. doi: 10.1016/S0378­3820(97)00079­9 VASSILEV, S. & VASSILEVA, C. (2009): A new approach for the combined chemical and mineral classification of the inorganic matter in coal. 1. Chemical and ...
    ... coal in seam II predominates in the whole seam, while xylite­rich coal is present in thin layers near the up­ per and lower parts of the seam. A mixture of mineral­rich and matrix coal is present in thin layers near the floor of the seam. Stratified matrix coal in seam I predominates in the whole ...

  • NMR kinetic studies of the interactions between [Ru(terpy)(bipy)(H2O)]2+ and some sulfur-donor ligands

    Aleksandar Mijatović, Biljana Šmit, Ana Rilak, Biljana Petrović, Dragan Čanović, Živadin D. Bugarčić (2012)
    Reakcije supstitucije monofunkcionalnog [Ru(terpi)(bipi)(H2O)]2+ kompleksa, gde je terpi = 2,2′:6′,2″-terpiridin i bipi = 2,2′-bipiridin, sa biološki relevantnim sumporo donorskim ligandima, kao što su tiourea, l-metionin, l-cistein i glutation, proučavane su u vodenim rastvorima tehnikom 1H i 13C NMR spektroskopije. Sve reakcije su proučavajne na pH 7,4, u prisustvu fosfatnog pufera, da bi se oponašalo fiziološko okruženje tokom procesa supstitucije. Reakcije se izvode na 295 K pod uslovima reakcija drugog reda. Uočeni rezultati pokazuju da brzina supstitucije snažno zavisi ...
    Materials Chemistry,Inorganic Chemistry,Physical and Theoretical Chemistry

  • Frequency and Length of Syllables in Serbian

    Marija Radojičić, Biljana Lazić, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Ján Mačutek, Lívia Leššová (2019)
    Basic analyses of several properties of syllables (the rank-frequency distribution, the distribution of length, and the relation between length and frequency) in Serbian is presented. The syllabification algorithm used combines the maximum onset principle and the sonority hierarchy. Results indicate that syllables behave similarly to words as far as mathematical models are concerned, but values of parameters in models for syllables are quite different from those for words.
    frekvencije slogova, dužina slogova, srpski jezik
    ... frequencies in the language material we used (𝐶 = 0.0880). Given that we work with a complete novel consisting of 110104 words, it is necessarily a text mixture rather than a homogeneous text (Popescu et al., 2009, set an upper limit - admittedly an arbitrary one - of 10000 words for a homogeneous text, see ...
    ... frequencies in the language material we used (C = 0.0880). Given that we work with a complete novel consisting of 110104 words, it is necessarily a text mixture rather than a homogeneous text (Popescu et al., 2009, set an upper limit - admittedly an arbitrary one - of 10000 words for a homogeneous text, see ...

  • Synthesis and characterization of high-pressure and high-temperature sphene (CaTiSiO5)

    Jelena Pantić, Vladimir Urbanovich, Vesna Poharc-Logar, Bojan Jokić, Marija Stojmenović, Aleksandar Kremenović, Branko Matović (2014)
    Sphene (CaTiSiO5), a calcium titanosilicate ceramic has been prepared from a powder mixture of CaCO3, TiO2 and SiO2 using vibro-milling for homogenization and activation of precursors. During the highpressure and high-temperature synthesis (HPS) process at 4 GPa and 1,200 °C, sphene undergoes into phase transition, from room-temperature phase P21/a to high-temperature phase A2/a. Evidence of that structural phase transition is given in this paper using infrared, Raman spectroscopy and X-ray powder diffraction. Rietveld refinement was employed to get the ...
    Sphene, Phase transition, Raman spectroscopy, X-ray diffraction, SEM, IR

  • Crystallography and Surface Oxidation of Stoichiometric Arsenopyrite from Šumadija-Kopaonik Pb-Zn/Polymetallic Ore District (Serbia)

    Ivana Jelić, Aleksandar Pačevski, Aleksandar Kremenović, Aleš Šoster, Andreja Šestan, Janez Zavašnik (2023)
    The behaviour and stability of arsenopyrite largely depend on its crystal structure, but studies of crystallography and structural defects are scarce. For clarification, we investigated a series of natural arsenopyrite crystals from the polymetallic Pb-Zn-(±Cu,Ag,Au,Sb,Bi,W) Šumadija-Kopaonik ore district (Serbia) by powder X-ray diffraction (XRPD). Among them, samples from the Drenjak gold mineralisation showed near-stoichiometric FeAsS composition and were further investigated by conventional and high-resolution transmission electron microscopy methods. TEM revealed abundant planar crystallographic defects and epitaxial surface oxide layer ...
    Inorganic Chemistry, Condensed Matter Physics,General Materials Science, General Chemical Engineering, crystal structure, FeAsS, oxidation, TEM, XRPD
    ... e and Co-enriched cobaltite-type enrichment zones [10]. For verification, we investigated the local chemical composition by EDS analysis, which shows coherent, stoichiometric FeAsS chemical composition in both domain types without any deviation compared to the bulk grain. Additionally, the SAED ...
    ... several Cu-sulphides [25,26] and were interpreted as an ordered variation of the chemical composition, i.e., the periodic arrangement of impurities. This interpretation cannot be applied to our observations, as the chemical analysis by TEM-EDS shows no variation from the arsenopyrite stoichiometric ...
    ... weathering of the Au-containing arsenic sulphide minerals [4]. The ability to incorporate Au in FeAsS structure coincides with the vast amount of (geo)chemical data published, which contrasts sharply with the available structural data [2,5-7]. The ambiguous structure of arsenopyrite has been analysed ...

  • Дигиталне библиотеке у рударству и геологији са посебним освртом на представљање сиве литературе

    Биљана Лазић, Александра Томашевић, Михаило Шкорић (2019)
    Имајући у виду потребу за проналажењем информација похрањених у различитим облицима документације која се генерише у областима рударства и геологије на Рударско-геолошком факултету Универзитета у Београду, отпочет је процес развоја дигиталне библиотеке ROmeka@RGF, на платформи за приказивање дигиталних колекција - Омека. Значајан део документације представља такозвана сива литература која је претежно заступљена у виду вишетомне документацијe. Први савладани изазов представљало је повезивање различитих вишетомних делова пројектних извештаја у једну целину која би била лако доступна и претражива.
    дигиталне библиотеке, сива литература, Омека, језички ресурси, речници
    ... parts in one consistent unit that is easily accessible and searchable. One more challenge is the nature of the project documentation which is the mixture of textual, numerical, graphical and cartographical contents. In order to solve the above-mentioned problems we used a platform for digital objects ...

  • The interaction of organoselenium trans-palladium(II) complexes toward small-biomolecules and CT-DNA

    Vera M. Divac, Aleksandar Mijatović, Marina D. Kostić, Jovana Bogojeski (2017)
    Serija organoselenijum trans-paladijum(II) kompleksa 1 (bis(2-(fenilselanilmetil)oksolan)dihloropaladijum(II)), 2 (bis(2-(fenilselanilmetil)oksan)dihloropaladijum(II)) i 3 (bis(2) ,2-dimetil-3-(fenilselanil)oksan)dihloropaladijum(II)) su korišćeni za ispitivanje reaktivnosti ovog specifičnog tipa kompleksa prema različitim bio-molekulima. Ovaj sistem je od posebnog interesa jer se jako malo zna o supstitucionim reakcijam organoselenijum paladijum(II) kompleksa sa trans konfiguracijom. Zamena koordinovanog hlorida sa serijom malih bio-molekula (l-Met, l-His, l-Cis, GSH i 5′-GMP) proučavana je pod uslovima pseudo-prvog reda kao funkcija koncentracije nukleofila i temperature korišćenjem tehnika zaustavljenog toka. Rezultati za proučavane komplekse ukazuju da ...
    Pd(II), Selen, Substitucija, Kinetika, Mehanizam

  • Surface functional groups and degree of carbonization of selected chars from different processes and feedstock

    Marija Ilić, Franz-Hubert Haegel, Aleksandar Lolić, Zoran Nedić, Tomislav Tosti, Ivana Sredović Ignjatović, Andreas Linden, Nicolai D. Jablonowski, Heinrich Hartmann (2022)
    The knowledge ofthe structural and chemical properties of biochars is decisive for their application as technical products. For this reason, methods for the characterization of biochars that are generally applicable and allow quality control are highly desired. Several methods that have shown potential in other studies were used to investigate two activated carbons and seven biochars from different processes and feedstock. The chars were chosen to cover a wide range of chemical composition and structural properties as a hardness ...
    Biougalj, različiti procesi dobijanja, različite sirovine, površinski aktivne grupe, x-ray, FT-IR,XPS
    ... chars for the investigations in Belgrade (SEM, XRD, FT-IR, Raman, titrations), the chemical analyses, XPS, and SIP in Julich. Subsamples were taken from these samples for each ofthe determinations. For each of the chemical analysis (C, H, N; oxygen; other elements), except ash determination, three ...
    ... the use as a fuel. X-ray photoelectron spectroscopy XPS yields results on the chemical composition in a thin layer at the surface of material, these results may be considerably different from those of the chemical analysis of bulk materials. Despite that fact, the overview of the elements (Table ...
    ... presence of phosphoric acid in AC2, additional chemical analysis might be necessary to elucidate the true composition. X-ray diffractograms show the presence of crystalline inorganic compounds for some of the chars in accordance with the chemical analysis and a transition of the carbon-rich matrix ...

  • The influence of Al<sup>3+</sup>ion on porcine pepsin activity<i>in vitro</i>

    Vesna M. Pavelkić, Kristina R. Gopcević, Danijela Z. Krstić, Marija A. Ilić (2008)
    The in vitro effect of Al3þ ions in the concentration range 1.7·1026M–8.7·1023M on pepsin activity at pH 2, via kinetic parameters and its electrophoretic mobility was evaluated. Kinetic study demonstrated the existence of an activation effect of Al3þ at pH 2 on pepsin molecule. Kinetic analysis with respect to concentrations of haemoglobin showed that Al3þ ions increase the maximal velocity (Vmax) and kcat values rather than apparent affinity for substrate (KS) implying the non-competitive nature of activation which indicated ...
    Пепсин, алуминијум, кинетика, активација, електрофоретска мобилност
    ... ions on the activity of extra- cellular enzymes is scant and controversial. Variability of data results from the chemical properties of the element and the formation of various chemical species, depending on the pH, ionic strength, presence of competing elements and complexing agents within the ...
    ... trypsin activity, but do not pepsin. It was observed highest activation of pepsin activity by 191% in the presence of 25 ag AP?/ mL of reaction mixture [25]. As the mechanism of Al'* ions on pepsin activity is not still clear, the objective of this study is to investigate the m oitro influence ...
    ... filtrates' recorded at 28Onm, and activities were calculated by the equation: [42sorFiltrate) — 412go(Blank)} X 1000 10 min X mg enzymcein reaction mixture () U anius, /mg — Estimation of hinetic barameters Kinetic analysis was carried out according to a slightly modified method of Anson [26] ...

  • Microstructural and magnetic properties of electrospun hematite/cuprospinel composites

    Mira Ristić, Aleksandar Kremenović, Michael Reissner, Željka Petrović, Svetozar Musić (2020)
    Phase composition, microstructural and magnetic properties of electrospun hematite/cuprospinel composites were investigated. Samples were synthesized starting with 0 to 10 mol% of copper relative to iron. The round shape of reference electrospun fbres was preserved upon their heating up to 600 °C in air, whereas at 700 °C hollow substructure was additionally formed. In these reference samples the presence of hematite phase was detected by XRPD. A small amount (traces) of Fe3O4 /γ-Fe2O3 was also found, due to the ...
    Electrical and Electronic Engineering, Condensed Matter Physics, Atomic and Molecular Physics and Optics, Electronic, Optical and Magnetic Materials

  • Definition of Circulation Conditions and Groundwater Genesis of the Complex Krupaja Hydrogeological Karst System (Eastern Serbia)

    Ljiljana Vasić, Saša Milanović, Tina Dašić (2023)
    Management, Monitoring, Policy and Law,Renewable Energy, Sustainability and the Environment, Geography, Planning and Development, Building and Construction
    ... they infiltrate into the discharge channel of deep thermal water. The physico-chemical characteristics of the groundwater (related to the seasons) of the Krupaja system are shown in Table 1. Table 1. Basic physico-chemical parameters of the Krupaja system. ; Temperature Electrical Dissolved Turbidit: ...
    ... spring, and air temperatures up to 35 "C. The borehole groundwater temperature is constant at around 8 "C (18.4–18.7 "C); this water comprises a mixture of cold and thermal water. The water emperature at the bottom of the borehole reaches a value of up to 25 "C. The groundwater emperature at the ...
    ... thermal spring groundwater, is significantly lower, amounting to 3.9 TJ and only 1.7 TJ. These contents, shown on Table 4, indicate a mixture of old and sub-modern (semi-old) water that has more recently infiltrated into the system. The carbon C content of the Krupaja Spring, groundwater is 74 ...

  • Influence of paleoenvironmental conditions on distribution and relative abundance of saturated and aromatic hydrocarbons in sediments from the NW part of the Toplica basin, Serbia

    Nikola Burazer, Aleksandra Šajnović, Nebojša Vasić, Milica Kašanin-Grubin, Dragana Životić, João Graciano Mendonça Filho, Predrag Vulić, Branimir Jovančićević (2020)
    Stratigraphy,Economic Geology,Geology,Geophysics,Oceanography

  • FTIR spectroscopic study оf S-мetolachlor сorption оn inorganic and organically modified montmorillonite from Bogovina

    Lazar Kaluđerović, Zorica Tomić, Jelena Bogosavljević, Ljubomir Životić, Maja Milošević (2021)
    ... MATERIALS AND ME THODS Materials HDTMA-bromide was obtained from Alfa-Aesar Chemical Company (Karlsruhe, Germany), with a purity of 98%. Phenyltrimethylammonium chloride (PTMA) was supplied by the Tokyo Chemical Industry Company (Toshima, Kita-Ku, Tokyo, Japan), with a purity of 98%. A raw ...
    ... lonite (50% of CEC), 51.75 mmol/100 g of Na-montmorillonite (75% of CEC), and 69 mmol/100 g of Na- montmorillonite (100% of CEC). The reaction mixture was continuously stirred on the magnetic stirrer, at the temperature of 50%C. After the modification, the suspension was further agitated for 24 ...
    ... to parent herbicides (Hladik et al., 2006). Montmorillonite is a clay mineral widely used in various industries due to its specific physical and chemical properties, such as cation exchange capacity (CEC), large surface area, high pore volume, high swelling ability, etc. Intercalation of organic complexes ...

  • Geotechnical zoning of the terrain along the first section of E-80 highway in Serbia – SEETO route 7

    Dragoslav Rakić, Zoran Berisavljević, Irena Basarić, Snežana Bogdanović, Jovana Janković (2019)
    Part of E-80 highway that passes through Serbia (from the city of Nis to the administrative border Merdare) is 77 km long. The highway is divided into two sections: the first from Nis to Plocnik (39.4 km long) and the second from Plocnik to the administrative border with Kosovo. The route is designed through a typical plain and hilly terrain in which different geological units are dominant: crystalline schists, neogene sediments of foothills and quaternary sediments in the valley ...
    ... crosses alluvial relief of the Toplica River tributaries and river terraces of smaller distribution (al, pr, t1, t2). In small streams there is a mixture of sands, gravel and rarely clays that are often muddy and saturated, but can be well drained. River-terraced plateaus are outside the influence ...
    ... wires. Amphibolites do not represent a permanent horizon, but appear in the form of lenses with max thickness of 10 m. Products of physical- chemical decomposition of this complex have different thicknesses, ranging from 0.5 m to over 5.0 m. More solid gneisses and amphibolite have thinner ...

  • Geochemical characterization of sediments from the archaeological site Vinča – Belo Brdo, Serbia

    Gorica Veselinović, Dragana Životić, Kristina Penezić, Milica Kašanin-Grubin, Nevenka Mijatović, Jovana Malbašić, Aleksandra Šajnović (2020)
    Earth-Surface Processes

  • Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae

    Hans Peter Nytoft, Geir Kildahl-Andersen, Sofie Lindström, Frode Rise, Achim Bechtel, Danica Mitrović, Nataša Đoković, Dragana Životić, Ksenija A. Stojanović (2019)
    Two previously unidentified dehydroabietane isomers were isolated from Miocene Serbian lignite and Rhaetian (Late Triassic) coaly mudstones from South Sweden and characterized using NMRspectroscopy as cis- and trans-dehydroicetexane. Both have a 9(10?20)-abeo-abietane or icetexane skeleton, consisting of a 6-7-6 tricyclic framework with seven carbons in ring B instead of the usual six in common diterpanes of the abietane-type. Dehydroicetexanes can be detected using GC-MS-MS in m/z 270?146 chromatograms without interference from dehydroabietane or other isomers. Dehydroicetexanes are often abundant ...
    Geochemistry and Petrology