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Упит dcterms_subject_txt:carbon and oxygen isotopes

2351 items

  • Oxygen vacancy-induced microstructural changes of annealed CeO 2-x nanocrystals

    Askrabiac Sonja, Dohceviac-Mitrović Zorana, Kremenović Aleksandar, Lazarević Nenad, Kahlenberg Volker, Popović Zoran V. (2012)

  • A new polymorph of Ba(AsO3OH): Synthesis, crystal structure and vibrational spectra

    Tamara Đorđević, Ljiljana Karanović (2010)
    A new monoclinic polymorph of Ba(AsO3OH) was synthesized under hydrothermal conditions. It represents a previously unknown structure type. Its crystal structure was determined from a racemic twin using single-crystal X-ray diffraction data collected at 120 and 293 K [space group P21, a=7.2149(14)/7.2370(2), b=7.7028(15)/7.7133(2), c=21.7385(43)/21.8079(5) Å, β=95.95(3)/96.073(1)1, V=1201.6(4)/1210.51(5) Å3, Z=12]. The crystal structure of P21-Ba(AsO3OH) has a layered character and is built up of four types of regularly alternating layers parallel to (0 0 1). Every AsO3OH tetrahedron is chelating to two Ba atoms and ...
    Ba(AsO3OH), хидротермална синтеза, структурна анализа монокристала, Раманска спектроскопија, инфрацрвена спектроскопија, водоничне везе, хидрогенарсенати земноалкалних метала

  • Available technological procedures for capturing CO2 in the industrial and power generation sectors

    Lola Tomić, Vesna Karović Maričić, Dušan Danilović, Branko Leković, Miroslav Crnogorac (2021)
    Climate change is a major environmental issue caused by anthropogenic emissions of greenhouse gases. Capturing CO2 and storing it in suitable geological formations is one of the main technological solutions that can provide mitigation of CO2 emission into the atmosphere. Capturing CO2 represents the first phase in process of carbon capture and storage, and includes the application of various technologies for the separation of CO2 produced in the energy and industrial sectors. There are four main systems for capturing ...
    capturing CO2, power plants, CO2 capture systems, CO2 technologies
    ... energy.gov/fe/science-innovation/carbon-capture-and-storage-research/carbon-capture-rd/pre-combustion-carbon https://www.energy.gov/fe/science-innovation/carbon-capture-and-storage-research/carbon-capture-rd/pre-combustion-carbon https://co2crc.com.au/about-ccus/carbon-capture/ https://www.ccsbrowser ...
    ... of fossil energy and carbon management. Available online: https://www.energy.gov/fe/science-innovation/carbon-capture-and-storage-research/carbon- capture-rd/pre-combustion-carbon (accessed on 03 August 2021). 13. CO2CRC. Available online: https://co2crc.com.au/about-ccus/carbon-capture/ (accessed ...
    ... composed of carbon monoxide (CO) and hydrogen (H2), which is known as a synthesis gas or syngas. The produced syngas is mixed with steam in a catalytic reactor, which promote reaction between CO and water, producing hydrogen and CO2-rich gas mixture and increase mole concentration up to 40 and 55 %, r ...

  • Adsorption and Polymerization of Aniline on Cu(II)-Montmorillonite:  Vibrational Spectroscopy and ab Initio Calculation

    M. Ilić, E. Koglin, A. Pohlmeier, H. D. Narres, M. J. Schwuger (2000)
    Batch adsorption experiments in the presence of oxygen were performed to study the interlayer reactions of aniline on Cu(II)-montmorillonite in aqueous solutions. At concentrations below a critical value of CC ) 2.6 mmol dm-3 only a colored Cu(II)-aniline complex is formed, characterized by a stability constant of log(Kassoc/dm3 mol-1) ) 1.5. At concentrations beyond Cc aniline polymerizes yielding a dark brown product, which is identified by two vibrational spectroscopy techniques, attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and ...
    Анилин, адсорпција, полимеризација, Cu(II)-Монтморилонит, ФТИР, аб инитио прорачун

  • In vitro and in silico study of the biological activity of tetradentate Schiff base copper(II) complexes with ethylenediamine-bridge

    Aleksandar Mijatović, Nevenka Gligorijević, Dušan Ćoćić, Snežana Spasić, Aleksandar Lolić, Sandra Aranđelović, Milan Nikolić, Rada Baošić (2023)
    The biological activity of six structurally similar tetradentate Schiff base copper(II) complexes, namely [Cu(ethylenediamine-bis-acetylacetonate)] (CuAA) and five derivatives where two methyl groups are replaced by phenyl, (CuPP), CF3 (CuTT) or by mixed groups CH3/CF3 (CuAT), Ph/CF3 (CuPT), and Ph/CH3 (CuAP) has been investigated. The set of antioxidant assays was performed, and the results were expressed as IC50 and EC50 values. The series of complexes showed interesting bioactivity and were investigated for the determination of antioxidant, antifungal, antimicrobial, and cytotoxic ...
    Inorganic Chemistry, Biochemistry

  • In vitro and in silico study of the biological activity of tetradentate Schiff base copper(II) complexes with ethylenediamine-bridge

    Aleksandar Mijatović, Nevenka Gligorijević, Dušan Ćoćić, Snežana Spasić, Aleksandar Lolić, Sandra Aranđelović, Milan Nikolić, Rada Baošić (2023)
    The biological activity of six structurally similar tetradentate Schiff base copper(II) complexes, namely [Cu (ethylenediamine-bis-acetylacetonate)] (CuAA) and five derivatives where two methyl groups are replaced by phenyl, (CuPP), CF3 (CuTT) or by mixed groups CH3/CF3 (CuAT), Ph/CF3 (CuPT), and Ph/CH3 (CuAP) has been investigated. The set of antioxidant assays was performed, and the results were expressed as IC50 and EC50 values. The series of complexes showed interesting bioactivity and were investigated for the determination of antioxidant, antifungal, antimicrobial, and ...
    Inorganic Chemistry,Biochemistry

  • Trace elements and garnet formation in a distal skarn zone: a case study of the Rudnik deposit, Central Serbia

    Bojan Kostić, Pavle Tančić, Natalija Batoćanin (2024)
    geohemija granata, retke zemlje, fluidne inkluzije, skarnovsko ležište Rudnik

  • Valorization of non-balanced coal reserves in Serbia for underground coal gasification

    David Petrović, Lazar Kričak, Milanka Negovanović, Stefan Milanović, Jovan Marković, Nikola Simić, Ljubisav Stamenić (2019)
    In the name of a better and safer energy future, it is our responsibility to focus our knowledge and activities to save on imported liquid and gas fossil fuels, as well as coal on which energy security of Serbia is based. The rationalization in the use of available energy resources certainly positively affects economy and the environment of a country. This paper indicates motivations for the application of the underground coal gasification process, as well as surface gasification for ...
    ugalj, gasifikacija, zaštita životne sredine, skladištenje, solarna
    ... bar and — capacity up to 4000 mš of gas/h. And for the gas parameters are: — quantity of produced gas up to 100000 mž of gas/h, — gas pressure 0.2 bar, and — gas temperature 200-400 *C. Air, Oxygen, Steam CO,CO, H„ CH, |- —— Oxidation zone. —— j- Reduction zone +| -- Drying and Pyrolysis ...
    ... from the gas mixture of UCG, and its possible storage carbon capture and storage, depends on the technological development of the separation and storage of CO [3]. Syngas can be used to produce a number of usable products, such as electricity, liquid fuels and chemical raw materials. The com ...
    ... Mining, Geology and Civil Engineering, Tuzla, Yugoslavia, 1987 3] Ag Mohamed, Acheick., et. al., Viability of UCG with Carbon Capture and Storage, 600 UCG Final Re- port, University School of Public and Environmental, Bloomington, Ind., USA, 2011 4] Petrović, D., ef al., Status and Tendecies under ...

  • Groundwater resources for drinking water supply in Serbia´s Southeast Pannonian basin

    Dušan Polomčić, Bojan Hajdin, Marina Ćuk, Petar Papić, Zoran Stevanović (2014)
    menadžment podzemnih voda, monitoring, kvalitet podzemnih voda, bilans, baza podataka

  • Geology of the southern part of the Sava-Vardar zone: new constraints from the Klepa Mts.

    Dejan Prelević, Ana Mladenović, Violeta Gajić, Milena Dunčić, Blažo Boev (2024)
    Tethys closure, Scaglia Rossa, intracontinental basalts
    ... sandstones, and conglomerates. The Late Cretaceous volcanics (82 Ma, Ar-Ar age; [1]) include pillow basalts, basaltic sheet flows, columnar lava, hyaloclastite, basaltic dykes, and microgabbros, which exhibit clear geochemical signatures (trace clements, Sr, Nd, Pb isotopes) of within-plate ...
    ... carbonate rocks arc represented by reddish, locally pinkish, or grey, light grey hemipelagic and pelagic biomicrites with rich planktonic and · benthic · foraminiferal associations. and othcr diverse micro- and macrofossil assemblages (calcareous nannoplankton, calcified radiolarians, palynomorphs ...
    ... which encompasses the Dinaric, Carpathian, and Balkan double-verging Alpine orogenic belt, remains a topic of ongoing debate ({1], [2] and references therein). This orogenic system arose from thc closure of the northern branch of the Neotethys Ocean and subsequent collision-related processes. Key ...

  • Crystal structure of K3EuSi2O7

    Sabina Kovač, Predrag Dabić, Aleksandar Kremenović (2021)
    alkalni silikati elemenata retkih zemalja, kristalna struktura, sinteza metodom fluksa, rendgenska difrakcija na monokristalu
    ... valences are well balanced and the K‒O, Eu‒O and Si‒O bond lengths are consistent with the presence of K+, Eu3+, Si4+ and O2‒ in structure. Only the bond-valence sum for Eu1 is oversaturated (3.42 v.u.) which can be attributed to the environment of the Eu1O6 octahedron. All oxygen atoms from Eu1O6 octahedron ...
    ... than the nonbridging Si‒O bonds [1.616 (5) and 1.622 (7) Å]. The O‒Si‒O bond angles range from 106.7 (2) to 111.0 (4) °. Three potassium cations show three different coordination environments. The coordination sphere of K1 includes eight oxygen ions and forms a K1O2+4+2 coordination polyhedron ...
    ... space group P63/mcm and is isostructural with disilicates K3ErSi2O7 15 and K3YbSi2O7. 22 The crystal structure is comparable to the sorosilicate structure type reported earlier by Vidican and co-authors.13 The crystal structure of the title compound consists of Si2O7 groups and EuO6 polyhedra which ...

  • Photocatalytic Activity of the V2O5 Catalyst toward Selected Pharmaceuticals and Their Mixture: Influence of the Molecular Structure on the Efficiency of the Process

    Sanja J. Armaković, Aleksandra Jovanoski Kostić, Andrijana Bilić, Maria M. Savanović, Nataša Tomić, Aleksandar Kremenović, Maja Šćepanović, Mirjana Grujić-Brojčin, Jovana Ćirković, Stevan Armaković (2023)
    Due to the inability of conventional wastewater treatment procedures to remove organic pharmaceutical pollutants, active pharmaceutical components remain in wastewater and even reach tap water. In terms of pharmaceutical pollutants, the scientific community focuses on -blockers due to their extensive (over)usage and moderately high solubility. In this study, the photocatalytic activity of V2O5 was investigated through the degradation of nadolol (NAD), pindolol (PIN), metoprolol (MET), and their mixture under ultraviolet (UV) irradiation in water. For the preparation of V2O5, facile ...
    DFT analysis, metoprolol, nadolol, nanomaterial characterization, photocatalysis, pindolol, β-blocker
    ... that the main elements of the catalyst are vanadium and oxygen, and no other impurity elements could be detected (Figure 4). The atomic percentage of V and O in Spectrum 1 is estimated as 39.86% and 60.14%, respectively, indicating, possible oxygen deficiency on the edge of the platelet. The values ...
    ... Toxicity and remediation of pharmaceuticals and pesticides using, metal oxides and carbon nanomaterials. Chemosphere 2021, 275, 130055. CrossRef] Ali, L.; Alothman, Z.; Alwarthan, A. Uptake of propranolol on ionic liquid iron nanocomposite adsorbent: Kinetic, thermodynamics and mechanism of ...
    ... various or- ganic pollutants [21,23-27]. Most studied molecules are branched with at least one aromatic ring and nitrogen and oxygen atoms in their structure. Degradation pathways and degra- Molecules 2023, 28, 655 3of18 dation rate is determined by the nature of substituents on aromatic rings ...

  • Arsenic in Tap Water of Serbia´s South Pannonian Basin and Arsenic Risk Assessment

    Petar Papić, Marina Ćuk, Maja Todorović, Jana Stojković, Bojan Hajdin, Nebojša Atanacković, Dušan Polomčić (2012)
    kvalitet podzemnih voda, arsen, analiza rizika, Panonski Basen
    ... in the environment. Instead, it is usually combined with one or more other elements such as oxygen, chlorine, and sulfur. This combination is referred to as inorganic arsenic. Arsenic combined with carbon and hydrogen is referred to as organic arsenic. The organic forms are usually non-toxic or less ...
    ... by high con- centrations of naturally-occurring organic substances, and the presence of humic and fulvic acids and their salts. This is a result of their inability to break down into inorganic end products due to a lack of oxygen and bacteria in the ground- water, such that the organic substances are ...
    ... are associated with a reducing medium in which desorption and dissolution take place. Low Eh levels (<50 mV), the absence of dissolved oxygen, high concentrations of Fe, Mn, and NH4 +, elevated alkalinity, the presence of organic substances, and low sulfate concentrations (<5 mg/L) are general hydrochemical ...

  • Arsenic in tape waters of the south Pannonian basin (Serbia) and arsenic risk assessment

    Petar Papić, Marina Ćuk, Maja Todorović, Jana Stojković, Bojan Hajdin, Nebojša Atanacković, Dušan Polomčić (2012)
    ... in the environment. Instead, it is usually combined with one or more other elements such as oxygen, chlorine, and sulfur. This combination is referred to as inorganic arsenic. Arsenic combined with carbon and hydrogen is referred to as organic arsenic. The organic forms are usually non-toxic or less ...
    ... by high con- centrations of naturally-occurring organic substances, and the presence of humic and fulvic acids and their salts. This is a result of their inability to break down into inorganic end products due to a lack of oxygen and bacteria in the ground- water, such that the organic substances are ...
    ... are associated with a reducing medium in which desorption and dissolution take place. Low Eh levels (<50 mV), the absence of dissolved oxygen, high concentrations of Fe, Mn, and NH4 +, elevated alkalinity, the presence of organic substances, and low sulfate concentrations (<5 mg/L) are general hydrochemical ...

  • FTIR Spectroscopic Study Of S-Metolachlor Sorption On Inorganic And Organically Modified Montmorillonite From Bogovina

    Lazar Kaluđerović, Zorica Tomić, Jelena Bogosavljević, Ljubomir Životić, Maja Milošević (2021)
    ... aromatic benzene ring of S-metolachlor and the aromatic benzene ring of the organic complex (π-π bonds). Also, the formation of a hydrogen bond occurs between the molecules of S-metolachlor and the molecules of water that are in the interlayer space and/or oxygen on the surface of the tetrahedral sheet ...
    ... increasing presence in soil, groundwater and surface water. Numerous methods are developed in order to reduce herbicide mobility and protect natural water resources. The results presented in this paper show the interaction of herbicide S-metolachlor with inorganic and organically modified montmorillonite ...
    ... quartz, cristobalite and carbonate minerals. Organic montmorillonites were obtained after modiffication with different concentrations of organic complex (HDTMA and PTMA), whereas inorganic modification was performed with 1M NaCl solution. The interaction between minerals and herbicide was monitored ...

  • Early–Middle Jurassic brachiopods from Ponor Mountain, Western Balkan Mountains, Bulgaria; taxonomy, biostratigraphy and occurrence in the context of the early Toarcian Oceanic Anoxic Event

    Barbara V. Radulović, Lubomir S. Metodiev, Neda Motchurova-Dekova, Platon Tchoumatchenco (2023)
    Brachiopods, taxonomy, biostratigraphy, early Toarcian Anoxic Event, Bulgaria

  • Anisotropic grossular–andradite garnets: Evidence of two stage skarn evolution from Rudnik, Central Serbia

    Bojan Kostić, Danica Srećković-Batoćanin, Petyo Filipov, Pavle Tančić, Kristijan Sokol (2021)
    This paper presents LA-ICP-MS data for garnets from the Rudnik skarn deposit (Serbia), which range from Grs45–58Adr40–52Alm2–3 in the core and Adr70–97Grs2–29Sps1 in the rim displaying anisotropy and zoning. In spite of wide compositional variations the garnets near the end-member of andradite (Adr > 90) are generally isotropic. Fe-rich rims exhibit LREE depletion and flat HREE pattern with weak negative Eu anomaly, including higher As and W contents. On the other side, the Fe-poorer core shows flat REE pattern ...
    grandite, garnets, skarn, Rudnik
    ... indicates reduced condi- tions and Eu divalent state that led to different behaviour of REEs; • Hydrothermal fluids from the second stage could indicate magmatic origin of fluids, considering elevated W concen- trations in the andradite garnet rim combined with sulphur isotopes in sulphide minerals; • ...
    ... Mining and Geology. Conditions for microanalysis were spot size 2 µm, an accele- rating voltage of 30 kV and a beam current of 10 nA, using natural and synthetic mineral standards including albite (Al, Si), wollastonite (Ca), titanium monoxide (Ti), chromium oxide (Cr), and manganese (Mn) and iron ...
    ... grossu- lar, almandine and spessartine components. REE and trace elements The REE patterns of the studied skarn garnets are norma- lized to the chondrite value of McDonough & Sun (1995) and shown in Fig. 5. Y being a pseudolanthanide was included and plotted between Dy and Ho. Different zones during ...

  • Molecular and Isotope Composition of Biomarkers in Immature Oil Shale and its Liquid Pyrolysis Products (Open and Closed System)

    Gordana Gajica, Aleksandra Šajnovic, Jan Schwarzbauer, Aleksandar Kostić, Branimir Jovančićević, Ksenija Stojanović (2021)
    The molecular and isotopic composition of biomarkers in initial bitumen isolated from raw immature oil shale samples from the Lower Miocene Aleksinac Basin (Serbia) and liquid products (LPs) obtained by pyrolysis in open (OS) and closed systems (CS) are studied. The influence of pyrolysis type and variations of kerogen type on biomarkers composition and their isotopic signatures in LPs is determined. The molecular composition of the LPs from the OS pyrolysis is very similar to those in initial bitumen, independently ...
    ... J.W., 1979. Nature 279, 405– 408. Peters, K.E., Walters, C.C., Moldowan, J.M., 2005. The Biomarker Guide, Vol. 2: Biomarkers and Isotopes in Petroleum Exploration and Earth History. Cambridge University Press, Cambridge. ...
    ... outcrop oil shale samples, assigned as D13 and D16 (huminite reflectance of 0.41 % Rr) from the Lower Miocene Aleksinac Basin, which is the largest and richest oil shale deposit in Serbia. The selected samples showed high content of total organic carbon (TOC > 13 wt. %), high hydrocarbon generation ...
    ... performed in open (OS, Pyrolyser, Model MTF 10/15/130 Carbolite, UK) and closed (CS, autoclave) systems at a temperature of 400 °C for 4 h. The biomarker signatures were evaluated using gas chromatography-mass spectrometry and carbon specific isotope analysis (δ13C) of individual n-alkanes in initial ...

  • Adsorption and degradation of some psychiatric drugs by sol-gel synthesized titania-based photocatalysts: influence of tungsten and sodium content

    Nina L. Finčur, Maja J. Šćepanović, Mirjana Grujić-Brojčin, Biljana F. Abramović, Jugoslav B. Krstić, Aleksandar Kremenović, Tatjana Srećković, Aleksandar Golubović (2019)
    Mesoporous anatase nanopowders were doped with 0.05−0.5 mol% of W6, in order to obtain more efficient photocatalyst than TiO2 Degussa P25 in the degradation of amitriptyline (AMI) under simulated solar irradiation (SSI). Dominant XRPD peaks were ascribed to anatase phase, with additional peaks which could correspond to brookite, TiO2 bronze and sodium titanate, Na2Ti9O19. The Raman scattering measurements have confirmed anatase as dominant phase, with broad Raman feature at ~270 cm−1 possibly related to Ti–O–Na stretching vibration. All W-doped ...
    Sol-gel synthesis, Doped titania nanopowders, XRPD, Raman spectroscopy, Adsorption and photocatalytic degradation, Psychiatric drugs

  • 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
    ... FeOOH, followed by FexAsyO and Fei-x„.,AsnyS [23], which does not coincide with our observations. A longer oxidation of 25 days resulted in the formation of a thicker layer, starting, with 9 nm of oxygen and As-rich zone low in Fe and S, followed by 13 nm of an oxygen-deficient zone with a composition ...
    ... analyses, and Supplementary Information File S2: TEM-EDS analysis of the oxidised and reference arsenopyrite sample (Figuure S1). Author Contributions: Conceptualisation, LJ., A.P. and J.Z.; methodology, J.Z. and AŠ. (Andreja Šestan); software, A.Š. (Aleš Šoster); validation, LJ., A.P., A.K. and J.Z ...
    ... A.K., AŠ. (Andreja Šestan) and J.Z.; investigation, LJ.; resources, A.P.; data curation, LjJ. and J.Z.; writingz— original draft preparation, 1.J., A.P., A.K., AŠ. (Andreja Šestan), and A.Š. (Aleš Šoster); writing— review and editing, LJ., A.P., AŠ. (Aleš Šoster) and J.Z.; visualisation, J.Z.; ...