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Упит dcterms_subject_txt:crystal structure

445 items

  • 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

  • State and perspective of individual household heating in Serbia: A survey-based study

    Boban Pavlović, Dejan Ivezić, Marija Živković (2021)
    This paper presents the results of the household survey on individual household heating systems in Serbia. The survey was conducted in the period October to December 2020 with the participation of 1100 households with individual household heating systems. The information collected in the questionnaire can be separated into three main parts: basic household data, current heating system characteristics, and households’ perceptions and attitudes. The survey results provide unique and comprehensive information concerning individual household heating systems and the main ...
    Domaćinstva, Individualni sistemi grejanja, Korišćenje energije, Stavovi potrošača, Anketa, Srbija

  • 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

  • The Dictionary of the Serbian Academy: from the Text to the Lexical Database

    Ranka Stanković, Rada Stijović, Duško Vitas, Cvetana Krstev, Olga Sabo (2018)
    In this paper we discuss the project of digitization of the Dictionary of the Serbo-Croatian Standard and Vernacular Language. Scanning and character recognition were a particular challenge, since various non-standard character set encoding was used in the course of the almost 60-year long production of the dictionary. The first aim of the project was to formalize the micro-structure of the dictionary articles in order to parse the digitized text of and transform it into structured data stored in relational lexical database. This approach ...
    computer lexicography, lexical database, language resources, dictionary, Serbian language
    ... as the main task of such endeavors. To do this, the text of a dictionary has to be parsed and the structure of the arti- cles has to be formalized. For the representation of this formal structure markup languages are used, preferably standard ones that support interchange and merging (Lemnitzer et ...
    ... markers, in terms of the information they con- vey and their position in the articles of the Dictionary, was performed. A feature structure, as a general-purpose data structure which identifies and groups together individ- ual features, each of which associates a name with one or more values, was mapped ...
    ... encoding was used in the course of the almost 60-year long production of the dictionary. The first aim of the project was to formalize the micro-structure of the dictionary articles in order to parse the digitized text of and transform it into structured data stored in relational lexical database. This ...

  • The Importance of Detailed Groundwater Monitoring for Underground Structure in Karst (Case Study: HPP Pirot, Southeastern Serbia)

    Marina Čokorilo Ilić, Ana Mladenović, Marina Ćuk, Igor Jemcov (2019)
    Geography, Planning and Development,Aquatic Science,Biochemistry,Water Science and Technology
    ... Underground Structure in Karst (Case Study: HPP Pirot, Southeastern Serbia) Marina Čokorilo Ilić, Ana Mladenović, Marina Ćuk, Igor Jemcov Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] The Importance of Detailed Groundwater Monitoring for Underground Structure in ...
    ... aggressiveness; tunnel vulnerability 1. Introduction The presence of an underground structure in a karst can have a considerable impact on the natural status of groundwater and, conversely, the groundwater can affect the structure (the two are in constant interaction). In general, karst areas are risky for ...
    ... aggressiveness; tunnel vulnerability 1. Introduction The presence of an underground structure in a karst can have a considerable impact on the natural status of groundwater and, conversely, the groundwater can affect the structure (the two are in constant interaction). In general, karst areas are risky for ...

  • The Usage of Various Lexical Resources and Tools to Improve the Performance of Web Search Engines

    Krstev Cvetana, Stanković Ranka, Vitas Duško, Obradović Ivan (2008)
    In this paper we present how resources and tools developed within the Human Language Technology Group at the University of Belgrade can be used for tuning queries before submitting them to a web search engine. We argue that the selection of words chosen for a query, which are of paramount importance for the quality of results obtained by the query, can be substantially improved by using various lexical resources, such as morphological dictionaries and wordnets. These dictionaries enable semantic ...
    LR web services, MultiWord Expressions & Collocations, Information Extraction, Information Retrieval
    ... the most frequent structure for compounds with two components is adjective+noun, followed by the compounds with the structure X+noun, where X means “a word form that does not inflect within the compound”. For compounds with three components the most frequent structure is noun+X+X. Data on ...
    ... woman’ but also with Albion. 5. The inflection of free phrases by predicting their syntactic structure. Our presumption is that many free phrases used for search will have the same syntactic structure as a compound, and that the inflectional transducers for compounds that we have already developed ...
    ... cases this structure can be predicted on the basis of morphological and syntactic features of the phrase components. These features can be obtained from the morphological e-dictionaries that are at our disposal during the query expansion process. The prediction of the phrase structure is also ...

  • Uniaxial compressive strength test before and after standard fire test on rock mass

    Stefan Mitrović, Goran Todorović, Bojan Kostić, Milica Mirković-Marjanović, Nikola Božović, Marija Krstić, Aleksandar Erić, Radovan Gospavić, Snežana Ilić, Aleksandar Kijanović (2022)
    ... impact on the tunnel structure, different measures will be required to ensure the excavation and a larger amount of material needed for construction of tunnel structure. Incidental actions in tunnels, such as fire, can also affect strength of surrounding rock. Due to structure of rock mass, it is ...
    ... least partly of metamorphic origin. The different size of this mineral, poorly sorted indicates a relatively short transport of the material. Crystal fragments are less presented, mostly small and sub-rounded. Feldspars, orthoclase and plagioclase, which originate from a granitoid rock, are dominated ...
    ... experimentally. It depends on the structure of the rock mass, grain size and orientation, number and arrangement of cracks and fissures. For the same rock, strength may be different, depending on physical characteristics. Heat of environment can affect structure of rock mass, which results in a change ...

  • Extensive vibrations of the belt conveyer drive electromotor of a bucket wheel excavator as a result of intesified wear-and-tear of its mount support

    Vesna Damnjanović, Predrag Jovančić, Snežana Aleksandrović (2017)

  • INVENTS: A Hybrid Mine Ventilation Planning and Design System

    Lilić Nikola, Stanković Ranka, Obradović Ivan (2013)
    Ventilation system analysis is a complex process based on the calculation and analysis of numerous parameters. These problems can be successfully solved by the SimVent numerical package, but a full understanding and use of the obtained results require the involvement of an experienced specialist in the ventilation field. The solution was found in the creation of a hybrid system INVENTS, whose knowledge base represents a formalization of the expert knowledge in the mine ventilation field. In this paper we ...
    hybrid systems, mine ventilation, expert systems
    ... expert knowledge in the mine ventilation field. In this paper we present the design methodology of the hybrid system INVENTS, as well as system structure and user interface. Keywords: hybrid systems, mine ventilation, expert systems 1. Introduction The methodology of mine ventilation planing ...
    ... shown on figure 4. SimVent is a software package that enables mine ventilation simulation in underground exploitation of ore deposits. The global structure of the mathematical model for ventilation simulation in mine ventilation networks, transformed into the SimVent software package is composed of ...
    ... within the SimVent data service: Baza and BazaSimVent, which represent modules. In view of the complexity of the INVENTS system’s global model data structure, which had to model all relevant parameters of complex mine ventilation networks, the design and realization of database was executed in the MSAccess ...

  • INVENTS: a hybrid system for subsurface ventilation analysis

    Nikola Lilić, Ranka Stanković, Ivan Obradović (2000)
    Ventilation system analysis is a complex process based on the calculation and analysis of numerous parameters. These problems can be successfully solved by the SimVent numerical package, but a full understanding and use of the obtained results require the involvement of an experienced specialist in the ventilation field. The solution was found in the creation of a hybrid system INVENTS, whose knowledge base represents a formalization of the expert knowledge in the mine ventilation field. In this paper we ...
    ... expert knowledge in the mine ventilation field. In this paper we present the design methodology of the hybrid system INVENTS, as well as system structure and user interface. Keywords: hybrid systems, mine ventilation, expert systems 1. Introduction The methodology of mine ventilation planing ...
    ... shown on figure 4. SimVent is a software package that enables mine ventilation simulation in underground exploitation of ore deposits. The global structure of the mathematical model for ventilation simulation in mine ventilation networks, transformed into the SimVent software package is composed of ...
    ... within the SimVent data service: Baza and BazaSimVent, which represent modules. In view of the complexity of the INVENTS system’s global model data structure, which had to model all relevant parameters of complex mine ventilation networks, the design and realization of database was executed in the MSAccess ...

  • Geotechnical Conditions for Construction of Savski Trg Metro Station as a Part of the Belgrade Metro Line One

    Nemanja Stanic, Dragoslav Rakic, Josip Isek, Slavoljub Simic (2024)
    In order to solve serious traffic congestion in Belgrade, a number of studies regarding the Belgrade Metro construction have been carried out since 1973. However, only in 2019, the routes of the future metro lines 1 and 2 were de-fined as a part of the General Metro Construction Project. The lines are de-signed to intersect at the location of Sava Square, where an interchange met-ro station will be built. It represents a complex geotechnical structure consist-ing of three different ...
    metro station, geotechnical modelling, displacements

  • Rule-based Automatic Multi-word Term Extraction and Lemmatization

    Ranka Stanković, Cvetana Krstev, Ivan Obradović, Biljana Lazić, Aleksandra Trtovac (2016)
    In this paper we present a rule-based method for multi-word term extraction that relies on extensive lexical resources in the form of electronic dictionaries and finite-state transducers for modelling various syntactic structures of multi-word terms. The same technology is used for lemmatization of extracted multi-word terms, which is unavoidable for highly inflected languages in order to pass extracted data to evaluators and subsequently to terminological e-dictionaries and databases. The approach is illustrated on a corpus of Serbian texts from ...
    term extraction, terminology, multi-word units, lemmatization, finite-state transducers
    ... forms mašine taložnice and korita trake ‘belt troughs’ would be both extracted by graph 03 (structure N2X) and graph 06 (structure NXN). Precedence would be given to the output of graph 03 because the structure N2X is much more frequent than NXN. For these two examples, it would be correct for the ...
    ... terms motor mehanizma za potiskivanje (structure N6X) ‘pusher mechanism engine’ and mehanizam za potiskivanje kašike (structure N6X) ‘bucket pusher mechanism’ while the complete correct term has five components motor mehanizma za potiskivanje kašike (structure N8X) ‘bucket pusher mechanism engine’ ...
    ... extracted besides it, e.g. oblozi trake, then some of these false interpretations would be removed – oblog for the structure N2X, and obloga trak and obloga traka for the structure NXN. Table 1. A MWT obloga trake, its possible inflected forms, and their interpretations by extraction graphs ...

  • 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

  • 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 ...
    ... for construction (km: 0.0-17.2) The second subsection is the longest one (about 12 km), so geological structure is slightly more complex with extremely variable lithological structure. Therefore, eight characteristic zones are defined (I – VIII). The beginning of this section is related ...
    ... „Slatina“ and „Bozurna“. 3.2.2. Section: bypass Prokuplje (km: 17.2-23.5) On this section, geological structure is complex in neotectonic and structural way. It includes two different structure blocks: so called Nis - Mio-Pliocene characterized by descending and Radan – Proterozoic metamorphic ...
    ... GEOLOGICAL CONDITIONS IN THE ZONE OF HIGHWAY ROUTE Regional rupture pattern indicates two systems of perpendicular structures that form a block structure of investigated terrain (Figure 2). The most prominent is the fracture zone in the central part of the route in Prokuplje area, general strike ...

  • Sinteza i karakterizacija nanoprahova u CeO2-Bi2O3 sistemu

    Marija D. Prekajski (2014-04-04)
    Nanoprahovi kristalnih faza iz serije čvrstih rastvora u pseudo-binarnom sistemuCeO2-Bi2O3 sintetisani su primenom jednostavne i ekonomične samopropagirajućemetode na sobnoj temperaturi korišćenjem nitrata metala i natrijum-hidroksida kaopolaznih supstanci. Osim krajnjih članova niza, CeO2 i niskotemperaturne polimorfnemodifikacije α-Bi2O3, sintetisani su i čvrsti rastvori nominalnog sastava Ce1-xBixO2-δ,gde je x = 0,1; 0,2; 0,3; 0,4; 0,5; 0,6; 0,7; 0,8; 0,9. Rezultati proučavanja metodomrendgenske difraktometrije na polikristalnom materijalu i ramanske spektroskopskeanalize pokazali su da su sintetisani prahovi sa nižim sadržajem bizmuta (x = 0,1 ...
    nanostrukturni materijali, čvrsti rastvori, CeO2, Bi2O3, rendgenskadifraktometrija praha, Ritveldova metoda, mikrostrukrurna analiza

  • Kristalne strukture Cs2HoSi4O10F i Cs2TmSi4O10F

    Predrag Dabić, Sabina Kovač, Aleksandar Kremenović (2021)
    ... = 2355.12 (10) 3, Z = 8 (for Cs2TmSi4O10F compound). The investigated compounds are isotypic to Cs2YSi4O10F [1] and Cs2ErSi4O10F [2]. The crystal structure of these compounds consists of multiple chains of SiO4-tetrahedra connected by infinite one-dimensional chains of REEO4F2-octahedra. Cesium cations ...
    ... The compounds were synthesized by the method of crystal growth from a high-temperature solution (Tmax = 1373 K) using REE2O3 (REE = Ho, Tm), SiO2 and CsF as starting materials. The crystal structures of both compounds were determined by single-crystal X-ray diffraction analysis. They represent mutually ...
    ... Kahlenberg, D. Schmidmair, A. , P. , Z. Krist.-Cryst. Mater., 231 (2016) 195 207. 27th Conference of the Serbian Crystallographic Society 85 CRYSTAL STRUCTURES OF Cs2HoSi4O10F AND Cs2TmSi4O10F P. Dabi a, S. a, A. Kr a a bia e-mail: predrag.dabic@rgf.bg.ac.rs During investigation focused ...

  • The Rift Sequence Stratigraphy of the Itebej Field (Pannonian Basin, Serbia)

    Saša Ivanišević, Jelena Radišić, Ivana Isić, Dejan Radivojević (2019)
    ... Miocene after the early syn-rift stage, a “wide-rift” stage (Tari et al., 1999) marked by marine transgression began. All wells at the Itebej structure drilled through the rift climax system tract sediments which include reef limestones, sandy limestones (rarely) and coarse carbonate sandstones ...
    ... source rock for Itebej field, while the source rock potential of the Badenian sediments is significantly lower. The reservoir rocks of the Itebej structure are syn-rift reef complex sediments and pre-rift deep-water turbidites. The syn-rift carbonate reservoir rocks have high-quality petrophysical ...
    ... petroleum system References Tari, G., P. Dovenyi, I. Dunkl, F. Horvath, L. Lenkey, M. Ștefănescu, P. Szafian, and T. Toth, 1999. Lithospheric structure of the Pannonian basin derived from seismic, gravity and geothermal data, in The Mediterranean Basins: extension within the Alpine Orogen, edited ...

  • 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
    ... work, the DFT approach was used to perform band structure calculations to complement our experimental observations and to compare band gaps. The model of VOs was generated according to the previously mentioned information regarding the crystal structure of V)»Os, The model of V»Os was first subjected ...
    ... regarding orthorhombic o-V>Os structure with Pnnm symmetry. This structure is associated with 21 Raman active modes (7a, + 3Big + 7Bog + 4Bxa,) [30], 10 of Wwhich are registered in the spectrum shown in Figure 5. These modes are unambiguously assigned to o-V>Os structure [30,31]: ~104(A„), 146(Bye ...
    ... The XRPD patterns were collected in the 4-90? 20 range, with a step of 0.01”, and a data collection speed of 5.1 ?/min. The low background sing}|e crystal silicon sample holder minimizes the background. Unit cell parameters and average crystallite size and lattice strain values were obtained by PDXL2 ...

  • VENTEX: An Expert System for Mine Ventilation Systems Analysis

    Ranka Stanković, Nikola Lilić, Ivan Obradović (1996)
    Analiza sistema za ventilaciju je komleksan proces, koji bazira na proračunu brojnih parametara, koji se odnose na: stanje mreže, provetrenost, stabilnost sistema, gubitke vazduha, klimatske uslove, gasno stanje, ugroženost od požara i opasne prašine. Navedeni problemi se uspešno rešavaju paketom SimVent, ali potpuno razumevanje i korišćenje dobijenih rezultata zahteva angažovanje iskusnog specijaliste iz oblasti ventilacije. Rešenje je nađeno u kreiranju ekspertnog sistema VENTEX, čija je baza znanja formalizacija ekspertskog znanja iz oblasti ventilacije rudnika. U radu je prikazana metodologija ...
    ekspertni sistem, ventilacija
    ... frames in the system. The frame system is a hierarchical structure incorporating inheritance as an important property. Slots of a frame can obtain values in several different ways. Since the frame system is a hierarchical structure, the slot values can be filled in on of the three following ...
    ... argued that the conceiving of system structure as an object-oriented frame system represents a natural approach bearing in mind the coupled numerical-symbolic nature of the system aimed at solving a hierarchically structured problem. The obtained system structure of the VENTEX system was realized ...
    ... the mine ventilation state, and the formalization of this strategy by means of a modified object-oriented analysis (OOA) model. The system structure and the main architectural components as well as their relation to the goal decomposition are described in Section 3. Implementation issues ...

  • 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