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Упит dcterms_subject_txt:chemical analysis

753 items

  • A Mathematical Learning Environment Based on Serbian Language Resources

    Radojičić Marija, Obradović Ivan, Stanković Ranka, Utvić Miloć, Kaplar Sebastijan (2018)
    In recent years, in line with ever growing usage of Information technology, the learning environments are changing. The amount of available learning materials in various forms has increased. These new environments demand comprehensive learning systems, which enable management of the learning corpus with special attention paid to relevant lexical resources. In this paper we present the concept of a Mathematical Learning Environment in Serbian (MLES), which is based on a corpus of mathematical materials and various lexical resources, enabling ...
    mathematical content, text processing, mathematical formulae
    ... mathematical support in solving real life problems from engineering practice. To that end complex issues had to be resolved, such as mathematical text analysis, processing of mathematical content in different formats, search of mathematical materials, indexing of mathematical content using Serbian lexical ...
    ... and lemmatization of user queries, semantic search, query expansion, expanded search and ranked retrieval results (Figure 2). Figure 2. Analysis of user query and semantic search IT Education and Practice Radojičić et al. 250 The third component handles application to real life ...
    ... information that lack due to insufficiently wide context in which the search results are presented. Annotation also alleviates the statistical analysis of the corpus, namely automatic assignment of the distribution of annotated linguistic properties. 5. APPLICATION TERMI The Termi application ...

  • Life Cycle Assessment of Individual Wood Biomass Heating Systems in Households

    Boban Pavlović, Dejan Ivezić, Marija Živković (2020)
    The use of solid fuels (wood biomass and coal) for heating of households continues to be common practice within European countries. Solid fuel combustion in households contributes more than 46% to total emissions of fine particulate matter. In this study, a life-cycle assessment (LCA) of firewood-based and pellet-based heating systems is performed. These two systems represent two different types of individual wood biomass heating systems. In the case of the firewood-based heating systems, it is analyzed a typical stove ...
    Grejanje, Analiza životnog ciklusa, Drvna biomasa, Individualni sistemi grejanja
    ... was largest in the wood pellet segment. Until 2016, over 54 pellet production facilities were actively operating [7]. To obtain a comprehensive analysis of the environmental impact of heating systems (HSs) based on wood biomass, a complete lifecycle process that involves a holistic cradle-to-grave ...
    ... is based on the international standards series ISO 14040. It is made up of four steps (four main phases): Goal definition and scoping, Inventory analysis, Impact assessment, and Interpretation [13] (Figure 1). Figure 1. LCA phases according to ISO 14040:2006 [14] These four steps are covered ...
    ... Republic of Serbia’s (AERS) report on the comparative costs of housing heating in the annual report [17]. The AERS’s methodology is based on the analysis of a typical flat of 60 m2 that is heated to 20°C for 16 hours a day, 180 days a year. The required specific heat for heating of 150 kWh/m2 has ...

  • A WebGIS Decision Support System for Management of Abandoned Mines

    Ranka Stanković, Nikola Vulović, Nikola Lilić, Ivan Obradović, Radule Tošović, Milica Pešić-Georgiadis (2016)
    ... reserves of mineral resources; and (b) abandoned mines with depleted reserves. Mines from the first group are especially interesting as objects for analysis when there is entrepreneurial and economic interest in their reactivation and evaluation of remaining reserves. As for those from the second group ...
    ... current situation. For the other subgroup only the expert assessment of the current situation can be carried out, as a basis for further action. Analysis and solutions of problems of abandoned mines is also important for management of natural resources beyond the mineral resources domain. This includes ...
    ... displayed using OpenStreet maps two additional layers are shown: polygons singled out by remote sensing methods and polygons resulting from the analysis of exploitation authorizations, requests for reclamation and site visits. The left side of the web page consists of four tabs: the list of layers ...

  • 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

  • Structural dissymmetrization of optically anisotropic Grs64±1Adr36±1Sps2 grandite from Meka Presedla (Kopaonik Mt., Serbia)

    Pavle Tančić, Aleksandar Kremenović, Predrag Vulić (2019)
    In this paper, grandite core with Grs64±1Adr36±1Sps2composition was crystallographically studied. This core represents zone A of the macroscopically visiblefive A–E zones of the optically anisotropic Grs58–64 Adr36–42Sps2 grandite. The applied procedure includes the detailed analysis of the powder diffraction patterns, and the Rietveld refinements of the crystal structures in a series of 18 space groups and two mixtures, which were followed by the comparative analysis of the R-values, site occupancy factors, and the bond lengths and angles. Synthesis of all ...
    grandite, XRPD, crystal structure, structural dissymmetrization

  • Rietveld crystal structure refinement of a natural rhombohedral grossular-andradite garnet from Serbia

    Pavle Tančić, Aleksandar Kremenović (2022)
    Four macroscopically visible B–E (rim) zones, within a large natural ferric grossular garnet of Grs58–64Adr36–42 Sps2 composition, are described by means of Rietveld refinements of the crystal structures in a series of six space groups, followed by com parative analysis of the R-values, site occupancy factors, and bond lengths and angles. The garnet crystallized in the rhombohedral R63c space group. Various polyhedral distortions and structural or derdis or dervariations between the zones studied are also described and discussed. The ...
    Geology

  • Improving Document Retrieval in Large Domain Specific Textual Databases Using Lexical Resources

    Ranka Stanković, Cvetana Krstev, Ivan Obradović, Olivera Kitanović (2017)
    Large collections of textual documents represent an example of big data that requires the solution of three basic problems: the representation of documents, the representation of information needs and the matching of the two representations. This paper outlines the introduction of document indexing as a possible solution to document representation. Documents within a large textual database developed for geological projects in the Republic of Serbia for many years were indexed using methods developed within digital humanities: bag-of-words and named ...
    ... system ranging from 0.87 to 0.99 (Fig. 9). In the query ispitivanje tla u Nǐsu ‘soil analysis in Nǐs’ linguis- tic preprocessing eliminates the preposition u ‘in’ unambiguously recognizes the nouns ispitivanje ‘analysis’ and tlo ‘soil’, whereas Nǐsu is recognized as the gen- itive of the toponym Nǐs ...
    ... found as substrings in many unrelated document words, like acronyms (e.g. SO derived from skupština opštine ‘municipality council’) and symbols of chemical elements (e.g. Ca for calcium). For each field searched within a specific facet, a weight factor is assigned. For example, when the facet ‘location’ ...
    ... developed (corpora and e-dictionaries), as well as applications for basic language processing (tokenization, Part-Of-Speech (POS) tagging, mor- phological analysis), information retrieval and extraction [26]. Several successful applications of Serbian language resources and tools in tasks related to document ...

  • Overcoming the Low Oral Bioavailability of Deuterated Pyrazoloquinolinone Ligand DK-I-60-3 by Nanonization: A Knowledge-Based Approach

    Jelena R. Mitrović , Branka Divović-Matović, Daniel E. Knutson, Jelena B. Ðoković, Aleksandar Kremenović, Vladimir D. Dobričić, Danijela V. Randjelović, Ivana Pantelić, James M. Cook, Miroslav M. Savić, Snežana D. Savić (2021)
    Poor water solubility of new chemical entities is considered as one of the main obstacles in drug development, as it usually leads to low bioavailability after administration. To overcome these problems, the selection of the appropriate formulation technology needs to be based on the physicochemical properties of the drug and introduced in the early stages of drug research. One example of the new potential drug substance with poor solubility is DK-I-60-3, deuterated pyrazoloquinolinone, designed for the treatment of various neuropsychiatric ...
    pyrazoloquinolinones, nanocrystals, wet media milling, fasted/fed bioavailability
    ... constant of 5.1 N/m. The cantilever driving frequency was around 150 kHz during the measurements. For the analysis of the taken topography and “error signal” AFM images, the software Image Analysis 2.2.0 (NT-MDT) was used. Differential Scanning Calorimetry (DSC) Around 2 mg of the dried samples of n ...
    ... to 50 mL/min. X-ray Powder Diffraction Analysis (XRPD) Nanocrystal dispersions with different particle sizes, corresponding suspension, and unprocessed DK-I-60-3 were investigated by X-ray powder diffraction (XRPD). Dispersions were centrifuged, and the analysis was performed on dried sediment. The ...
    ... respec- tively). 2.2.6. Statistical Analysis All measurements were performed in triplicate, and results were expressed as mean value ± SD, except in in vivo study where SEM was used instead of SD. After checking the normality of distribution, the statistical analysis involved Student’s t-test for two ...

  • Concepts for Improving Machine Learning Based Landslide Assessment

    Miloš Marjanović, Mileva Samardžić Petrović, Biljana Abolmasov, Uroš Đurić (2019)
    Katastar klizišta, Podložnost, Hazard, Mašinsko učenje, Uzorkovanje, Validacija

  • Review: Methodological approaches and research techniques for addressing construction and remediation problems in karst reservoirs

    Saša Milanović, Ljiljana Vasić (2021)
    Earth and Planetary Sciences (miscellaneous), Water Science and Technology

  • 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
    ... 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 ...
    ... IKA­Calorim­ eter adiabatic C 400, following the standard procedure (SRPS B.H8.318:1972, 1972). 3.4. X-ray diffraction (XRD) and SEM-EDS analysis Mineralogical analysis of forty­two (without the 28/91 and 31/91 samples) ash samples, heated to 450°C was carried out using Table 1. The maceral composition ...
    ... (ISO) 1171 (1997): Methods for analysis and testing of coal and coke. Determination of ash content.– Internation­ al Organization for Standardization, Switzerland (10 p). INTERNATIONAL STANDARD ORGANIZATION (ISO) 7404–2 (2009): Methods for the Petrographic Analysis of Coals–Part 2: Methods of Preparing ...

  • Rangiranja bagera za njihovu revitalizaciju primenom višekriterijumske analize

    Ivan Obradović, Dragan Ignjatović, Ranka Stanković, Ljiljana Ivković (2006)
    Obzirom da je na našim površinskim kopovima trenutno u eksploataciji veći broj rotornih bagera sa sličnim tehničkim karakteristikama i približno istom starošću postavlja se pitanje kako rangirati bagere, i kojim redom da se izvrši njihova revitalizacija. Za ocenu stanja i rangiranje ovako velikog broja bagera najpogodnije se pokazalo korišćenje višekriterijumskih metoda sa višeatributnom ocenom, odnosno bodovanje referentnih indikatora stanja bagera na osnovu ekspertske ocene. U ovom radu prikazan je metodološki pristup koji je korišćen prilikom izrade Studije «Produžetak radnog ...
    rotorni bageri, revitalizacija, rangiranje, višekriterijumska analiza
    ... feasibility study: Increasing of equipment work life in EPS open pit mines. KEY WORDS: BUCKET WHEEL EXCAVATORS, REVITALIZATION, RANKING, MULTICRITERIA ANALYSIS 1. UVOD Na svim površinskim kopovima u Srbiji se primenjuje kontinualna tehnika eksploatacije, tj. primena BTO sistema na otkopavanju jalovine ...

  • Uticaj ekstremnih procesa na rizike površinske eksploatacije

    Natalija Pavlović, Tomislav Šubaranović, Dragan Ignjatović (2022)
    Nepredvidivi ekološki negativni slučajni procesi mogu uticati na geo-tehnički sistem pri površinskoj eksploataciji ležišta mineralnih sirovina, što u velikoj meri uvećava rizike i ugrožava realizaciju proizvodnje. Kvantitativna analiza sa proračunom verovatnoća pojava ovakvih ekstremnih događaja i procenom odgovarajućih ekonomskih posledica, posebno u uslovima globalnih klimatskih promena, omogućava definisanje rizika i optimizaciju parametara sistema površinske eksploatacije.

  • Temperature induced evolution of nanostructured Ni0.9Zn0.1O

    Kremenović Aleksandar, Antić Bratislav, Vučinić-Vasić Milica, Colomban Philippe, Jovalekić Čedomir, Bibić Nataša, Kahlenberg Volker, Leoni Matteo (2010)
    The crystal structure and microstructure of as-prepared and annealed Ni0.9Zn0.1O were refined at room temperature in both the Fm (3) over barm and R (3) over barm space groups. It is shown that below the Neel point (458 K), where magnetic ordering triggers the presence of a trigonal strain, the common usage of a higher-symmetry non-admissible space group for crystal structure and microstructure analysis via the Rietveld method may result in both an incorrect structure description and incorrect microstructure ...

  • Malathion-induced inhibition of human plasma cholinesterase studied by the fluorescence spectroscopy method

    V. M. Pavelkić, K. S. Krinulović, J. Z. Savić, M. A. Ilić (2008)
    The in vitro effect of technical grade malathion was assessed via the kinetic parameters of human plasma butyrylcholinesterase (BChE) using N-methylindoxyl acetate as a substrate for BChE. An inhibitor kinetics study demonstrated the existence of a biphasic inhibition curve, indicating high- and low-affinity binding sites of malathion. The IC50 values as calculated from the experimental inhibition curves were 1.33 × 10–9 and 1.48 × 10–5 M for the high- and low-affinity binding sites, respectively; Hill’s analysis gave 1.29 × ...
    Малатион, инхибиција, хумана плазма холинестераза, метода флуоресцентне спектроскопије

  • Spatial assessment of the areas sensitive to degradation in the rural area of the municipality Čukarica

    Natalija Momirović, Ratko Kadović, Veljko Perović, Miloš Marjanović, Aleksandar Baumgertel (2019)
    Nature and Landscape Conservation, Soil Science, Agronomy and Crop Science, Water Science and Technology

  • Ostvarivanje dobiti pri uvođenju sistema agregatnih zamena na osnovnoj rudarskoj mehanizaciji površinskih kopova EPS

    Predrag Jovančić, Ignjatović Dragan, Đenadić Stevan (2021)
    Jedan od osnovnih zadataka na površinskim kopovima uglja je ostvarivanje zadovoljavajućeg vremenskog i kapacitetnog iskorišćenja kontinualnih sistema. Da bi se to postiglo, neophodno je izvršiti izmene u postojećoj strategiji održavanja. Preduslov je uvođenje agregatne zamene vitalnih delova na rudarskim mašinama. Benefiti su višestruki. Očekivani rezultati ovakvog pristupa su: smanjenje zastoja i povećanje vremena rada; direktne materijalne uštede; bolja organizacija rada; racionalizaciju radioničkih i magacinskih kapaciteta; povećanje vrednosti mašina. Da bi se uvela agregatna zamena neophodne su investicije za nabavku ...
    agregatne zamene, održavanje, mehanizacija, Benefit Cost analiza

  • Definition of criteria and alternatives for choosing the optimal mining method deposits when applying multi: Criteria optimization, Belgrade, June 2024

    Sanja Bajić, Dragoljub Bajić, Branko Gluščević, Radmila Gaćina, Josip Išek (2024)
    multi-criteria decision-making, definition of criteria, underground exploitation

  • Linear-motor plunger pump increases lifting efficiency

    Bojan Martinović, Dušan Đekić, Dušan Danilović, Pavel Isaev (2022)
    plunger, linear, motor, pumps

  • Environmental Noise Impact Assessment for Large-Scale Surface Mining Operations in Serbia

    Uros Pantelic, Petar Lilic, Aleksandar Cvjetic, Nikola Lilic (2023)
    Noise emissions are a significant environmental impact caused by the mining industry in all technological phases of surface mining, mineral processing, and waste disposal. This paper presents the role of noise impact assessment and control in large-scale surface mining operations. Mine planning develops the model of mining operations, ore excavation, and waste dumping scheduling and processing rates, including spatial distribution of mining activities. Such a level of mine planning requires an environmental impact assessment study. This can be achieved ...
    mine planning, noise impact assessment, mining, noise mapping, environmental impact assessment