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Упит dcterms_subject_txt:mathematical content

473 items

  • Mineralogical and physicochemical characterization of bentonite clay from Svrljig, Serbia

    Maja Milošević, Bojan Kostić (2022)
    ... sample consists mostly of a fraction <1 μm (56.1%) with a 9.5% <2 μm, representing a total clay content (65.5%). Coarse grain fraction (>20 μm) is present in a total of 10.5%. When the clay, silt and sand content were plotted on the triangular diagram, it was concluded that the sample is sandy clay with ...
    ... FeO, 6.34% CaO and 1.17% MgO, with a lower content of MnO (0.70%), Na2O (0.08%), TiO2 (0.35%) and BaO (0.03%). Higher values of the SiO2/Al2O3 mass ratios (2.97) together with LOI of 16%, CEC (84.5 mmol/100g) and SSA (661.8 m2*g–1) indicate a higher content of montmorillonite. Infrared spectrophotometry ...
    ... ometry determined that the composition corresponds to a high content of montmoril- lonite clay with peaks at 3620 cm–1, 3420 cm–1, 1632 cm–1 and 1018 cm–1. The peaks at 1444 cm–1 and 873 cm–1 correspond to carbonate minerals, although in a very small quantity. X-ray diffraction indicates that the ...

  • Multivariate analysis of metals content in urban snow near traffic lanes in Novi Sad, Serbia

    Mihailović Aleksandra, Vučinić Vasić Milica, Ninkov Jordana, Erić Suzana, Ralević Nebojša M., Nemeš Tomas, Antić Aleksandar (2014)

  • Factorial experimental design for selective flotation of chalcopyrite from copper sulphide ore with moderate content

    Kostović Milena, Lazić Predrag, Vučinić Dušica, Deušić Slaven, Tomanec Rudolf (2015)

  • Investigation of the relationship between reliability of track mechanism and mineral dust content in rocks of lignite open pits

    Radiša Đurić, Vladimir Milisavljević (2016)

  • Laboratory testing of fly ash

    Miloš Šešlija, Aleksandra Rosić, Nebojša Radović, Milinko Vasić, Mitar Đogo, Milovan Jotić (2016)
    Fly ash is one of the most common waste materials created by burning of coal. It is composed of smaller particles, consisting mainly of aluminosilicate glass, mullite and quartz, which are collected by electrostatic separators (filter) of gaseous products arising from the combustion of coal. This paper presents the pozzolanic properties, mechanical properties, chemical and mineral composition of fly ash obtained in the combustion process in a power plant Nikola Tesla A (PPNT A) with the addition of a ...
    chemical composition, fly ash, mechanical properties, mineral properties, pozzolanic properties, X-ray diffraction
    ... ng periods from 1983 to 2004, showed the following variations: - the content of SiO2 is lower by about 2 %, - the content of Al2O3 is increased by 1 to 1,5 %, - the content of Fe2O3 is lower by 1 to 1,5 %, - the content of CaO in the ash is lower by about 7 %. Laboratory testings of fly ...
    ... (ASTM C 618, 1994) Based on certain oxide content, fly ash can be divided into: Table 3 Classification of fly ash to ASTM C-618 [17] Class Ash Chemical composition F Sour Very low in Ca, slather Fe, (SiO2+Al2O3+Fe2O3) > 70 (%) C Alkaline High content CaO (SiO2+Al2O3+Fe2O3) > 70 (%) The ...
    ... adding 4 % of the cement as the binder. With the greater amount of cement content the modulus of elasticity decreases and with the lime added as the binder the test results are obtained with significant variations in the content of the same binder quantity. The test results are shown in Tab. 14. ...

  • The effect of the content of unburned carbon in bottom ash on its applicability for road construction

    Trifunović Prvoslav, Marinković Slobodanka, Tokalić Rade, Matijašević Srdjan (2010)

  • Influence of carbon dioxide content in the biogas on nitrogen oxides emissions

    Živković Marija, Adžić Miroljub, Fotev Vasko, Milivojević Aleksandar, Adžić Vuk, Ivezić Dejan, Ćosić Boško (2010)

  • Content and mode of occurrences of rare earth elements in the Zagrad karstic bauxite deposit (Nikšić area, Montenegro)

    Radusinović Slobodan, Jelenković Rade, Pačevski Aleksandar, Simić Vladimir, Božović Darko, Holclajtner-Antunović Ivanka, Životić Dragana (2017)

  • Heavy metals in lignite and soil of Kostolac-Kovin coal basin, eastern Serbia - comparative analysis with selected cities in Serbia, region, Europe and world

    Bogoljub Vučković, Bojan Dimitrijević (2023)
    The Kostolac-Kovin coal basin with an area of 320 km2, with 5 separate layers of coal and with a total of about 5.7 Bt of geological resources and reserves represents an exceptional potential for coal production in Serbia. The coal resources listed in this way are not fully exploitable, but they represent potential for consideration. In this paper, we deal with the geochemical characteristics of coal seams and perform a comparative analysis of coal affectation on the environment. With ...
    lignite, heavy metals, concentrations
    ... 181 3. COMPARATIVE PRESENTATION OF THE CONTENT OF HM IN THE LIGNITE OF THE BASIN AND SELECTED EXAMPLES - SERBIA, REGION, EUROPE AND THE WORLD For easier understanding of the content of these HM, we performed a comparative analysis of the content of HM ın the lignite's ofthe Kostolac - Kovin ...
    ... are marked increases in content in the marked locations of the World. 4. CONCLUSION The lignite of the Kostolac-Kovin Basin generally has low concentrations of hecavy metals, compared to worldwide cities top soils. In this work, special attention is paid to the content of Cu, Pb and Zn and their ...
    ... coals are extremely "toxic" and that their burning leads to significant soil pollution throughout Serbia and the world. However, measured data on HM content in the soil of cities throughout Serbia show a completely different picture. Namely, the contents of Zn, Pb and Cu are significantly higher in the ...

  • The Content of Toxic Metals in Agricultural Produce near a Coal Mine: Case Study KCB in Lazarevac, Serbia

    Ana Koprivica, Čedomir Beljić, Boris Vakanjac, Vesna Ristić Vakanjac, Marina Čokorilo Ilić (2018)
    Праћење и анализа концентрација токсичних метала (олово и кадмијум) у земљишту и усевима указују на то да пољопривредно земљиште у Србији углавном није загађено, а квалитет земљишта је природно добар. Због тога су таква земљишта погодна за органску пољопривреду. Сви уочени случајеви контаминације токсичним металима су само локалне природе, а резултат су ђубрива и пестицида, комуналног отпада, издувних гасова, оближњих производних објеката, топионица, рудника, јаловишта итд. Локације овог типа морају бити редовно прати и процењује статус земљишта и усева. ...
    токсични метали, олово, кадмијум, земљиште, усеви, одрживи развој

  • Using technology for knowledge transfer between academia and enterprises

    Ivan Obradović, Ranka Stanković (2014)
    ... components, namely: • Tools - composed of FMG CMS, an in-house Content Management System (CMS) developed by the University of Belgrade, Faculty of Mining and Geology (FMG), the Learning management system encompassing several specific content and learning management software tools, and Development tools ...
    ... tools, software to support the development, use, reuse and delivery of learning content; • Learning resources - both academic, in the form of course planning materials, video lectures, thematic content and the like, supported by evaluation tools, and entrepreneurial, such as case studies, best ...
    ... University of Belgrade Human Language Technology Group. Learning resources are both academic: course planning materials, video lectures, thematic content, and entrepreneurial: case studies, best practice examples, expert presentations and software demonstrations. Language resources supporting the ...

  • Characterization and Environmental Evaluation of Recycled Aggregates from Construction and Demolition Waste in Belgrade City Area (Serbia)

    Filip Abramović, Miroslav Popović, Vladimir Simić, Vesna Matović, Radmila Šerović (2024)
    General Materials Science

  • Petrological and geochemical studies of lignite from the Tamnava West field, Kolubara basin (Serbia)

    Milena Pajić, Reinhard F. Sachsenhofer, Achim Bechtel, Ksenija Stojanović, Vladimir Krstić, Dragana Životić (2021)
    ... constituents of saturated fractions with variable amount of m- alkanes and hopanoids. Content of sesquiterpenoids, triterpenoids and steroids in saturated fracttons is low. Aromatic fraction ıs characterised by high content of triterpenoids with variable amount of diterpenoids. The 16a(H)-phyllocladane ...
    ... interval] 60.3-88.2 m) were analysed. Coal from the Tamnava West field is typical humic coal with high huminite. lowerliptinite and low inertinite content. Textinite, ulminite and attrinite are the most abundant huminite macerals. Liptodetrinite, sporinite and suberinite are the most abundant liptinite ...
    ... inertodetrinite and fusinite are predominant inertinite maccrals. Organic carbon соп!ет(С) уапез 1 wide range from 25.52 to 61.21 %, while total sulphur content varies between 0.10 to 4.43 %. The yield of the extractable organic matter (bitumen) is high with sharp domination of asphaltenes and polar-NSO c ...

  • Open Educational Resources in Serbia

    Ivan Obradović, Ranka Stanković, Marija Blagojević, Danijela Milošević (2020)
    Open educational resources, BAEKTEL, Metadata portal
    ... other supporting TEL content including audio, video and written text materials, published by partners involved in the Tempus BAEKTEL (Blending Academic and Entrepreneurial Knowledge in Technology Enhanced Learning), provides searching capabilities for any type of published content. It includes: ...
    ... Serbia was founded in 2005 with the aim to allow free exchange of knowledge and participation in gathering educational content. Within thei educational program, they produce content in cooperation with schools and faculties, organize Edu Wiki Camp, Wiki Librarian, Digitization of techno culture ...
    ... (13). Figure 2. Classification of BAEKTEL portal content by type Topics of content (titles and keywords) are visualised by a word cloud in Figure 3. It can be seen that computer science, modeling and language ...

  • Mechanosynthesis and structural characterization of nanocrystalline Ce1–Y O2– (x=0.1–0.35) solid solutions

    Martin Fabián, Bratislav Antić, Vladimír Girman, Milica Vučinić-Vasić, Aleksandar Kremenović, Shigeru Suzuki, Horst Hahn, Vladimír Šepelák (2015)
    A series of nanostructuredfluorite-type Ce1–xYxO2–δ (0rxr0.35) solid solutions, prepared via highenergy milling of the CeO2/Y2O3mixtures, are investigated by XRD, HR-TEM, EDS and Raman spectroscopy. For thefirst time, complementary information on both the long-range and short-range structural features of mechanosynthesized Ce1–xYxO2–δ, obtained by Rietveld analysis of XRD data and Raman spectroscopy, is provided. The lattice parameters of the as-prepared solid solutions decrease with increasing yttrium content. Rietveld refinements of the XRD data reveal increase in microstrains in the host ceria ...
    Ceria, Yttrium, Solid solution, Mechanosynthesis, Oxygen vacancy, Nanocrystalline material

  • Assessment of spa mineral water quality from Vrnjačka Banja, Serbia: geochemical, bacteriological, and health risk aspects

    Nebojša Đ. Pantelić, Simona Jaćimović, Jana Štrbački, Danijela B. Milovanović, Biljana P. Dojčinović, Aleksandar Ž. Kostić (2019)
    The goal of this study is to evaluate the quality of seven natural mineral water sources in the Vrnjačka Banja area used in the treatment of various diseases. The 24 macro- and microelements were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The results show that element content was within allowed limits of concentration, except for B, As, and Se. The evaluated content of these elements can be associated with geological and anthropogenic factors. The sample S6 contains ...
    Management, Monitoring, Policy and Law, Pollution, General Environmental Science, General Medicine

  • Komparacija metoda XRF i ICP-MS na uzorcima uglja i produkata sagorevanja

    Branko Kostić, Dejan Prelević, Sabina Kovač, Ksenija Eraković, Dragana Životić (2022)
    Ugljevi niskog ranga – ligniti u Republici Srbiji predstavljaju glavnu energetsku sirovinu koja se koristi za proizvodnju električne energije. Rudarstvo u Srbiji doprinosi bruto dodatoj vrednosti sa 1,8% (2020; https://publikacije.stat.gov.rs/). Sagorevanjem ugljeva niskog ranga u termoelektranama generišu se velike količine elektrofilterskog pepela i pepela, koje često predstavljaju jedan od izvora zagađenja životne sredine usled sadržaja toksičnih elemenata. Dalja upotreba produkata sagorevanja zavisi od njihovog sastava i sadržaja toksičnih mikroelemenata. Svakodnevno sagorevanje lignita u termoelektranama uslovljava konstantan monitoring potencijalno toksičnih ...
    ugalj, produkti sagorevanja, XRF, ICP-MS

  • 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

  • Application of stochastic models for mine planning and coal quality control

    Dejan Stevanović, Božo Kolonja, Ranka Stanković, Dinko Knežević, Mirjana Banković (2014)
    ... n process in stockpiles throughout the mine's life. Sulfur content is treated as lognormally distributed random variable. The objec- tives of the model include minimizing the expected sulfur content and standard de- viation in sulfur content. The methodology was illustrated using the case study on Kolubara ...
    ... mine some parts of deposit with high con- tent of organic sulfur, over 2% (see fig. 7). Ad- justed on share of 95 percentiles content of sul- fur is over 1%, althought content in most of parts of the deposit is under 0.4%. The space distribution of sulfur required the homogeniza- tion of coal according ...
    ... proposed a methodology to generate equally probable models based on maps of sulfur content within a coal deposit in Kolubara surface mine. These models allow assessing the uncertainty associated with the grade content in the ROM coal supplied to the power plant. As the size (mass) of the pile in- creased ...

  • Određivanje zbijenosti starog komunalnog otpada

    Jovana Janković, Dragoslav Rakić, Irena Basarić Ikodinović, Tina Đurić (2021)
    Bez obzira na savremene tretmane komunalnog otpada u svetu, u Srbiji je i dalje najčešći vid odlaganja na komunalne deponije, pa zbijanje otpada predstavlja jednu od ključnih faza formiranja deponije. Na ovaj način znatno se smanjuje zapremina otpada, ubrzava proces degradacije i produžava radni vek deponije. Zbog toga su geotehničke karakteristike komunalnog otpada prilikom zbijanja, veoma bitne kako u fazi projektovanja tako i u fazi izgradnje deponije i optimizacije prostora. Tu se pre svega misli na maksimalnu suvu zapreminsku ...
    komunalni otpad, deponija, Proktorov opit, optimalna vlažnost, maksimalna suva zapreminska težina