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Упит dcterms_subject_txt:dissolved oxygen

95 items

  • 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

  • A survey of greenhouse gases production in central European lignites

    Anna Pytlak, Anna Szafranek-Nakonieczna, Weronika Goraj, Izabela Śnieżyńska, Aleksandra Krążała, Artur Banach, Ivica Ristović, Mirosław Słowakiewicz, Zofia Stępniewska (2021)
    Lignit, Gasovi sa efektom staklene bašte, Ugljen dioksid, Metan, Azotni oksid
    ... transition of NH4 to N2O by nitrification re- quires the availability of oxygen, the concentration of which is a factor that significantly determines the rate of the process (Khalil et al., 2004). The experimental treatments were oxygen-free so nitrification could not occur. On the other hand, availability ...
    ... exploration, examination and mining in Poland and the role of the State Geological Institute. Geol. Q. 35, 207–220. Cole, J.J., Prairie, Y.T., 2014. Dissolved CO2 in freshwater systems? Reference Module in Earth Systems and Environmental Sciences. Elsevier https://doi.org/10.1016/b978- 0-12-409548-9.09399-4 ...
    ... ofmicrobial activ- ity, was positively affected by NO3 - concentration and redox potential. With respect to methane formation, the lower atmospheric oxygen exposure of the sample from the Velenje undergroundmine compared to the samples from the opencast mines has been identified as a possible cause of ...

  • The subthermal potential of karstic groundwater of Kučaj–Beljanica region in Serbia estimated by the multivariate analysis

    Ljiljana Vasić, Dragana Ž. Živojinovic, Vladana Rajaković-Ognjanović, Huang Fen, Cao Jianhua (2021)
    Earth-Surface Processes, Geology, Pollution, Soil Science, Water Science and Technology, Environmental Chemistry, Global and Planetary Change

  • 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
    ... is also present. Generated gas mixture is similar to natural gas. If a vapor-oxygen mixture is used as a gasification agent instead of air, the optimal ratio should be about 7-8 kg of steam per m? of O». If only oxygen is used, the calorific value ofthe gas from such UCG process would be 2-2.5 times ...
    ... the air and with the oxygen. The NO, also appear somewhat during the combustion of nitrogen particles from fuel (mainly at > 1700 ?C ). Total amount of NO, are distinguished in the appropriate elements of the scrubbing system (NO, amount will be significantly lower if oxygen is used as a gasification ...
    ... surface waters, have been ex- posed to significantly different physical-chemical conditions and interdependencies, where the concentration of dissolved substances in them is much more diverse and changes according to the specific rules all the time. This is especially the case with the flow of aquifer ...

  • Sitni, ali bitni: uloga sitnih sisara, herpetofaune i mekušaca u rekonstrukciji pleistocenskih paleosredina

    Katarina Bogićević, Draženko Nenadić, Dragana Đurić, Mihajlo Jovanović, Aleksandra Savković (2023)
    Fosilni ostaci životinja i biljaka imaju važnu ulogu u rekonstrukciji pleistocenskih paleosredina. U ovom radu opisan je značaj tri grupe životinja: sitnih sisara, herpetofaune I mekušaca. Mada je za rekonstrukciju važan sastav čitave asocijacije, nalasci pojedinih vrsta mogu biti dovoljno indikativni da otkriju tip staništa ili klimatske uslove. Posebnu teškoću pri rekonstrukciji paleosredina u Srbiji predstavlja činjenica da klimatske promene na Balkanskom poluostrvu nisu bile tako oštre kao u srednjoj i zapadnoj Evropi, pa ne postoji drastična razlika u ...
    ... Andrews, P., (1981): Palacoecology of Miocene sites in western Kenya. Journal of Human Evolution, 10, 99-116. 4. Leng, M. J., & Lewis, J. P., (2016): Oxygen isotopes in Molluscan shell: Applications in environmental archacology, Environmental Archacology. The Journal of Human Palaeoecology, 21 (3), 295-306 ...
    ... warm climatic stages. Very important data on the palaeoclimatic characteristics of the environment can also be obtained by geochemical studies of oxygen isotopes in mollusc shells. Analyzing the isotopic composition of shells from successive lineages can provide not only information on seasonal climate ...
    ... Wirbeltierfaunistische Angaben zur Quartirchronologie der Jankovich- Hohle. Folia Archaeologica, 9, 16-21. Leng, M. J., & Lewis, J. P., (2016): Oxygen isotopes in Molluscan shell: Applications in environmental archacology, Environmental Archacology. The Journal of Human Palaeoecology, 21 (3), 295-306 ...

  • 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
    ... coordination sphere of K1 includes eight oxygen ions and forms a K1O2+4+2 coordination polyhedron which can be described as a distorted hexagonal pyra- mid with a split apex [distances range from 2.770 (5) to 3.049 (5) Å]. K2 atom is coordinated by nine oxygen atoms with distances from 2.923 (4) to ...
    ... 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 are common to all adjacent polyhedra around the K1 and K2 atoms for which BVS shows slightly undersaturated values. ...

  • 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
    ... 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 obtained ...
    ... plays a vital role in the creation of reactive oxygen species and the further interaction of released ions and radicals. The pH value of the aqueous solutions for DF was about 7.5 + the specified pH value of the aqueous solution, reactive oxygen species can be created in In the presence of V»Os ...
    ... The facile hydrothermal synthesis method was used to prepare V»Os powders [14,48]. For that purpose, 0.1 M ammonium metavanadate (NHaVOx) was dissolved in 80 mL of distilled water, resulting, in a pale yellow solution. To adjust the pH of the reaction solution to about 4, the diluted acetic acid ...

  • 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
    ... and from 543 to 560 us/cm at the thermal spring.. Dissolved oxygen is the highest at Krupaja Spring, during, the spring period (10.26 mg/L), which is a consequence of the turbulent regime and infiltration of fresh water into the system. Oxygen decreases with depth, so in the well, the values vary ...
    ... shown in Table 1. Table 1. Basic physico-chemical parameters of the Krupaja system. ; Temperature Electrical Dissolved Turbidit: Location OQ(U5) O PHValue | Conduetivity(HNŽs/cm) - Oxygen (mg/L) ONTU 'Krupaja Spring—Winter 1712 10 7.4 512 9.9 1.02 Krupaja Spring—Spring, 2111 10.2 744 526 10.26 0 ...
    ... , —3.81 —73.2 —9.98 Krupaja thermal springe —Summer —5.32 —72.81 —9.84 Krupaja thermal springo—Winter -3.11 —65.84 —9.83 The content of stable oxygen and deuterium isotopes also decreases with longer mean residence time, which is a consequence of isotopic fractionation, which takes place during ...

  • 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
    ... arsenic migration 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) ...
    ... cancer risk [3]. Arsenic in groundwater of Vietnam poses a serious health threat to millions of people, in the Hanoi area there are high levels of dissolved arsenic (average 121 µg/L) [4]. Arsenic concentrations in Shany, China, the worst affected of the regions in Shanxi Province, are as high as 4.4 mg/L ...
    ... not. Pure arsenic, a gray-colored metal, is rarely found 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 ...

  • 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)
    ... arsenic migration 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) ...
    ... cancer risk [3]. Arsenic in groundwater of Vietnam poses a serious health threat to millions of people, in the Hanoi area there are high levels of dissolved arsenic (average 121 µg/L) [4]. Arsenic concentrations in Shany, China, the worst affected of the regions in Shanxi Province, are as high as 4.4 mg/L ...
    ... not. Pure arsenic, a gray-colored metal, is rarely found 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 ...

  • 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)
    ... 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 of the montmorillonite. Keywords: adsorption, S-metolachlor, HDTMA, PTMA, infrared spectroscopy ...

  • 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

  • Study of the Synergetic Effect of Co-Pyrolysis of Lignite and High-Density Polyethylene Aiming to Improve Utilization of Low-Rank Coal

    Ivan Kojić, Achim Bechtel, Nikoleta Aleksić, Dragana Životić, Snežana Trifunović, Gordana Gajica, Ksenija Stojanović (2021)
    Polimeri i plastika, opšta hemija
    ... additionally finely grounded in an agate mortar. The prepared mixture was carefully sieved through a 150 µm sieve. The obtained fraction <150 µm was dissolved in distilled water and filtered through a Büchner funnel. Powdered HDPE was rinsed with distilled water until negative reaction to chlorides (using ...
    ... and the lig- nite/HDPE mixture (c). 2.5. Analysis of Lignite EOM and Liquid Pyrolysis Products Lignite EOM and liquid pyrolysis products were dissolved in chloroform, then quanti- tatively transferred to the flask by Pasteur pipette and left for solvent evaporation at room temperature. Samples were ...
    ... bottle using a Pasteur pipette and gently dried to the constant mass at ambient conditions. Maltenes from lignite EOM and the liquid pyrolysates were dissolved in the minimal volume of n-hexane (HPLC grade, Carlo Erba Reagents, Val de Reuil, France) (sonication in an ultrasonic bath) and separated into aliphatic ...

  • A hundred years of Milutin Milanković's climate change theory - geological implications

    Dejan Radivojević (2020)
    Миланковићева теорија циклуса објављена пре сто година је најважнија теорија у наукама које проучавају климу и имала је велики утицај на дисциплине које се баве Земљом. Ипак, његов рад је чекао више од педесет година да би добио потврду. Може се рећи да Миланковићев рад највећи утицај на геологију има у изради астрономске временске скале, подршци хипотези континенталног дрифта и палеоклиматологији. Добри резултати примене астрономске временске скале на неогене седименте иницирали су примену ове методе у мезозојским и у последње ...
    циклостратиграфија, астономска временска скала, геолошка временска скала, климатске промене, континентални дрифт
    ... will be noticeable in the oceans, where the increase of acidity and dissolved calcite will affect marine organisms with carbonate shells (THoMAS, 1998, 2003, 2007). This increase in vertical gradients can lead to a decrease of the oxygen Minimum zone (oMz) and the formation of almost anoxic conditions such ...
    ... HINNov, L. A. & oGG, j.G. 2007. Cyclostratigraphy and the As- tronomical Time Scale. Stratigraphy, 4 (2–3): 239–251. joyCE, S. 2000. The dead zones: oxygen-starved coastal wa- ters. Environmental Health Perspectives, 108: 120–125. KöPPEN, W. & WEGENER, A. 1924. die klimate der geologis- chen vorzeit ...
    ... and Gas Companies. Environmental Politics, 26 (4): 621–647. NICoLo, M., j., DICKENS, G. R. & HoLLIS, C. j. 2010. South Pacific intermediate water oxygen depletion at the onset of the Paleocene-Eocene Thermal Maximum as depicted in New zealand margin sections. Paleoceanography, 25: PA4210. oLSEN ...

  • 2D geoelectrical resistivity tomography application at the former city waste dump "Ada Huja": Eco-geological problem

    Branislav Sretenović, Filip Arnaut, Ivana Vasiljević, Vesna Cvetkov (2019)
    2D inversion, geoelectrical method, Wenner array, ecology, Ada Huja
    ... process), • Hydrolysis. Natural plastic degradation starts with the process of photodegradation. UV rays emit energy which is used to incorporate oxygen atoms into the polymer, and because of this, plastic becomes susceptible to strain (easier to break apart). This process is repeated until plastic ...
    ... 2D geoelectrical resistivity tomography … 73 3.2.3 Methane Methane is a carbonic compound formed when one hydrogen atom is linked to four oxygen atoms with single bounds. Methane is an odorless, colorless gas which is not toxic but is highly flammable and it is a side effect of every landfill ...
    ... housing estates but still a good road connection etc.) and after this the engineering part starts (correct isolation of the hole, pipelines for oxygen pumping and methane recovery, mini-station for leachate treatment etc.) Geoelectrical and geotechnical investigations that were carried out on ...

  • 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
    ... 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 similar to bulk FeAsS [24]. Compared to our experimental observations, the crystalline ...
    ... A.G.; Nesbitt, H.W.; Scaini, M.J.; Hoechst, H.; Bancroft, M.G.; Szargan, R. Reactivity of Surface Sites on Fractured Arsenopyrite (FeAsS) toward Oxygen. Am. Mineral. 2000, 85, 1754–1766. [CrossRef] Owen, N.D.; Ciobanu, C.L.; Cook, N.J.; Slattery, A.; Basak, A. Nanoscale Study of Clausthalite-Bearing ...

  • Definition of groundwater genesis and circulation conditions of the complex hydrogeological karst system Mlava–Belosavac–Belosavac-2 (eastern Serbia)

    Ljiljana Vasić, Saša Milanović, Zoran Stevanović, Laszlo Palcsu (2020)
    Geochemistry and Petrology

  • Polymorphism and photoluminescence properties of K3ErSi2O7

    Predrag Dabić, Marko G. Nikolić, Sabina Kovač, Aleksandar Kremenović (2019)
    alkalni silikati elemenata retkih zemalja, silikati lantanoida, polimorfizam, fotoluminescencija, kristalna struktura

  • Natural two-dimensional pyrophyllite: Nanoscale lubricant, electrical insulator and easily-machinable material

    Borislav Vasić, Radoš Gajić, Ivana Milošević, Žarko Medić, Marina Blagojev, Marko Opačić, Aleksandar Kremenović, Dejan Lazić (2022)
    Pyrophyllite, with the chemical formula Al2Si4O10(OH)2, is a naturally occurring and abundant van der Waals mineral belonging to the group of phyllosilicates. It is very soft, layered crystal used for sculpting and an excellent electrical and thermal insulator aimed for the operation at high pressure and temperature. Here, for the first time, two-dimensional (2D) pyrophyllite obtained by both mechanical and liquid phase exfoliation is presented and investigated at the nanoscale. The layered structure provides low friction coefficient of around ...
    Atomic force microscopy, Insulating properties, Nanofriction and wear, Natural two dimensional materials, Phyllosilicates, Pyrophyllite