Претрага

Упит dcterms_subject_txt:Economics and Econometrics

2340 items

  • Application of Lignite Combustion Waste Slag Generated in Heating Plants as a Partial Replacement for Cement. Part II: Physical–Mechanical and Physical–Chemical Characterization of Mortar and Concrete

    Milan Kragović, Nenad Ristić , Jelena Gulicovski, Andrijana Nedeljković, Snežana Pašalić, Ivica Ristović, Marija Stojmenović (2021)
    sagorevanje lignita, otpadna šljaka, zamena cementa, proizvodnja maltera i betona, fizičko-mehanička i fizičko-hemijska karakterizacija
    ... reference mixtures (E-M) and four mixtures (PM-10, PM-15, PM-20, and PM-25) in which cement was replaced with 10%, 15%, 20%, and 25% of slag and silica fumes regarding mass (whereby slag participated with 88%, and silica fumes with 12%). The mass ratio between the quantity of binder and sand in all mixtures ...
    ... 874, and 692 cm−1 are attributed to in- and out-plane bending and asymmetrical stretching vibrations of the O–C–O, respectively, which occur due to the presence of the CaCO3 [29]. The bands at 1100, 797, and 615 cm−1 indicate the presence of the SiO2 and are characteristic of asymmetrical and symmetrical ...
    ... sand and superplasticizer. Author Contributions: M.K. conceived and designed the experiments, wrote the paper, and con- tributed to all experiments and the analyzing of the obtained results; N.R. performed physical– mechanical measurements and contributed to analyzing the results; M.S., J.G. and I.R ...

  • Legal framework for recultivation of degraded areas caused by mining exploitation

    Radmila Gaćina (2023)
    Prilikom površinske i podzemne eksploatacije uglja eksploatacioni sistemi oštećuju veće ili manje površine zemljišta. Iskustva pokazuju da su oštećenja zemljišta znatno veća kod površinske eksploatacije, gde je prostora degradiran ne samo u konturi rudnika i okoline, već se promene takođe dešavaju u prirodnom okruženju. U članku su predstavljeni rezultati studije zakonskih okvira rekultivacije u nekim zemljama sveta i u Srbiji. Praktično iskustvo rekultivacije pokazalo je da iskorišćenje i devastacija tokom rudarske aktivnosti predstavljaju opasnost ne samo za pogođena ...
    rekultivacija, melioracija, otkopavanje uglja, zakonska regulativa
    ... of preventing environmental damage and also for humans. Mineral and coal mining often increases soil density, erosion, sedimentation, landslides, disruption of flora and fauna, and disruption of public health, which leads to microclimate change (Goudie and Viles, 2013). The post-mining impacts ...
    ... development of organizational and economic infrastructure. AUSTRALIA In Australia, for example, individual states and territories are responsible for mining, rehabilitation, and mine closure, including the adoption of individual laws, regulations, and guidelines. Industry and government agencies have ...
    ... Growth, Energy (ENR) and Environment Australia , Department od Regulated by Inspection Established Mines, Industry states and and Safety territories Germany Federal Ministry Depending on the District and Local for Economic fFederalState State Mining •ntities Affairs and Energy Authorities ...

  • 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

  • Towards the semantic annotation of SR-ELEXIS corpus: Insights into Multiword Expressions and Named Entities

    Cvetana Krstev, Ranka Stanković, Aleksandra Marković, Teodora Mihajlov (2024)
    Овај рад представља активности на развоју корпуса ELEXIS-sr, српском додатку вишејезичном анотираном корпусу ELEXIS-а, који се састоји од семантичких анотација и репозиторија значења речи. ELEXIS је паралелни вишејезични анотирани корпус на десет европских језика, који може да се користи као вишејезички репер за евалуацију европских језика са мање и средње развијеним ресурсима. Фокус овог рада је на вишечланим изразима и именованим ентитетима, њиховом препознавању у скупу реченица ELEXIS-sr и поређењу са анотацијама на другим језицима. Разматрају се први кораци ...
    полилексемске језинице, именовани ентитет, вишезначност значења речи, складиште смисла, LLOD

  • 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

  • A bilingual digital library for academic and entrepreneurial knowledge management

    Ranka Stanković, Cvetana Krstev, Biljana Lazić, Dalibor Vorkapić (2015)
    A generic knowledge management process of organization, storage and retrieval of knowledge can suitably be fitted in a digital library. In the digital and knowledge age digital libraries can be used in knowledge management to handle intellectual assets and support knowledge creation. A multilingual digital library either stores content in more than one language or provides multilingual query access to monolingual content. In Serbia 18 of 308 scientific journals regularly published are bi-lingual, with papers simultaneously being in English ...
    Knowledge management, Digital library, Multilingualism, Language Resources, Terminology
    ... of library and information sciences, digital humanities, architecture and mining and also project reports on academic and entrepreneurial knowledge and e-learning. It contains articles from three journals INFOtheca - Journal for Digital Humanities, Underground Mining Engineering, and Architecture ...
    ... 3 Design and methodology 3.1. Knowledge management and digital library Roknuzzaman reported overlaps between digital libraries and knowledge management, stating that a generic knowledge management process of acquisition, organization, storage and retrieval, and dissemination of knowledge ...
    ... are used to enhance and refine users’ queries. The query expansion is supported by e-dictionaries (Serbian morphological e-dictionaries), general purpose semantic networks (English and Serbian WordNets) and domain terminological bases and ontologies. A Dictionary of Library and Information Sciences1 ...

  • An arid phase in the Internal Dinarides during the early to middle Miocene: Inferences from Mg-clays in the Pranjani Basin (Serbia)

    N. Andrić-Tomašević, V. Simić, O. Mandic, D. Životić, M. Suárez, E. García-Romero (2020)
    Paleontology,Earth-Surface Processes,Ecology, Evolution, Behavior and Systematics,Oceanography

  • Application of machine learning for diagnosing the operation of a deep well pump in oil production

    Maja Trikić (2024)
    This paper will thoroughly examine how machine learning can improve the diagnosis of deep well pumps by analyzing the role and function of the pumps, dynamograms, sensor technologies, and diagnostic methods.Our analysis will provide insights into modern techniques and approaches for enhancing the performance and reliability of oil production systems, targeting cost reduction and increased operational efficiency.
    deep well pump, dynamograms, machine learning, diagnostics of operating coditions,Random Forest, XGBoost
    ... Testing and Refining - Finally, we would test our program and iterate through steps 1 and 2, refining the rules and algorithms until we achieve satisfactory results. 17 This approach can be time-consuming and requires a lot of manual effort, as rules need to be constantly updated and adjusted ...
    ... application of machine learning is beneficial and can enhance diagnostics and management in rod pump systems. 6.3. Application of methods and materials The oil and gas industry must reduce costs and improve operational efficiency by leveraging data and investing in new technology to increase pr ...
    ... Number analysis Fourier and Wavelet (Numpy) (Pandas and Descriptors Scikit learn) ___ LI ı “Všec 6} .A e OC Model testing J ·/J \ Shuffle and stratified and metrics Balance (Scikit learn) (PYCM) . dataset - Algorithms, AutoML (Imblearn) Separate training and Tuning and test datasets Hipe ...

  • Using technology for knowledge transfer between academia and enterprises

    Ivan Obradović, Ranka Stanković (2014)
    ... thematic content, and entrepreneurial: case studies, best practice examples, expert presentations and software demonstrations. Language resources supporting the multilinguality of the platform, terminology and its search and browse functions are lexical and textual resources and grammars. Impl ...
    ... contributes to improvement and enhancement of relations between the academia and the enterprises and integration of creative research potential with industry and academic institutions. The second objective within our project is to develop and implement guidelines and procedures for quality assurance ...
    ... initiative, where materials are offered openly and freely to educators, students, and self-learners to use and reuse for teaching, learning, and research (Bissell, 2009). The materials are released under an open source license which permits their use, reuse and redistribution with limited or no restrictions ...

  • Fragmentation Size Prediction of Blasted Material Using a Specialized Software for Drilling and Blasting

    Stefan Milanović, Nikola Simić, Lazar Kričak, Milanka Negovanović, Nikola Đokić, Miljan Gomilanović (2024)
    Design and optimizing the drilling and blasting parameters, should fill the requirements for the capacity, fragmentation size, and technical characteristics of loading and transport equipment, and enable a safe work at the open pit. Besides mentioned, it also achieves the minimal impact on the environment of the open pit and decreases the negative effects on the environment, especially in the blast vibration and flyrock. To obtain the best possible blasting effects and consider all the factors, a specialized software is ...
    optimization, O-Pitblast, drilling, blasting, fragmentation size

  • A hydrogeological model of the open-cast mine Tamnava - West Field (Kolubara Coal Basin, Serbia)

    Jelena Ratković, Dušan Polomčić, Dragoljub Bajić, Bojan Hajdin (2016)
    ... Belgrade (Fig. 1) and encompasses the area around the middle and lower courses of the Kolubara River and its tributaries: the Tamnava (left) and the Peštan (right). Tamnava – West Field falls within the municipalities of Lajkovac and Ub, near the villages of Kalenić, Mali Borak, Radljevo and Skobalj. To ...
    ... sand and clay); dpr - diluvial/proluvial sediments; am - oxbow sediments (mud and clay); t1 - lower river terrace; Q, Pl - riverine-lacustrine terrace; Pl1 - sand and clay (marly and coaly) There is a triple aquifer system in the extended zone of the study area: upper, intermediate and lower ...
    ... geological and hydrogeological research. In essence, the hydrogeologic model shows the types of rocks, from a hydrogeological perspective, and their geometry. The focus is on aquifers and their spatial relationships. Groundwater levels, directions of groundwater flow, and recharge and discharge zones ...

  • Differently shaped nanocrystalline (Fe, Y)3O4 and its adsorption efficiency toward inorganic arsenic species

    Biljana P Dojčinović, Boštjan Jančar, Lotfi Bessais, Aleksandar Kremenović, Nataša P Jović-Jovičić, Predrag T Banković, Dalibor M Stanković, Miloš Ognjanović, Bratislav V Antić (2019)
    Herein we report effects of partial substitution of Fe3+ by Y3+ in magnetite (Fe3O4) on morphology and inorganic arsenic species adsorption efficiency of the Fe3−xYxO4 nanoparticles formed. The series of Fe3−xYxO4 (x=0.00, 0.042 and 0.084, labeled as Y00, Y05 and Y10, respectively) was synthesized using co-precipitation followed by microwave-hydrothermal treatment (MW) at 200°C. With increase of yttrium content(xvalue), both the morphological inhomogeneity of the samples and the fraction of spinel nanorods as compared to spinel pseudospherical particles increased. By ...
    microstructure, microwave-hydrothermal synthesis, adsorption, magnetic nanoparticles, arsenic

  • Towards Semantic Interoperability: Parallel Corpora as Linked Data Incorporating Named Entity Linking

    Ranka Stanković, Milica Ikonić Nešić, Olja Perisic, Mihailo Škorić, Olivera Kitanović (2024)
    U radu se prikazuju rezultati istraživanja vezanih za pripremu paralelnih korpusa, fokusirajući se na transformaciju u RDF grafove koristeći NLP Interchange Format (NIF) za lingvističku anotaciju. Pružamo pregled paralelnog korpusa koji je korišćen u ovom studijskom slučaju, kao i proces označavanja delova govora, lematizacije i prepoznavanja imenovanih entiteta (NER). Zatim opisujemo povezivanje imenovanih entiteta (NEL), konverziju podataka u RDF, i uključivanje NIF anotacija. Proizvedene NIF datoteke su evaluirane kroz istraživanje triplestore-a korišćenjem SPARQL upita. Na kraju, razmatra se povezivanje Linked ...
    paralelni korpusi, povezivanje imenovanih entiteta, prepoznavanje imenovanih entiteta, NER, NEL, povezani podaci, NIF, Vikipodaci

  • Composition of organic matter and thermal maturity of Mesozoic and Cenozoic sedimentary rocks in East Herzegovina (External Dinarides, Bosnia and Herzegovina)

    Nikoleta Aleksić, Aleksandar Kostić, Miloš Radonjić (2021)
    This paper presents the first data on the organic matter and thermal maturity of Mesozoic and Cenozoic sedimentary rocks in the East Herzegovina region of the External Dinarides. Representative, organic-rich samples from outcropping sedimentary rocks of different ages in the area (Triassic to Neogene) were selected and analysed. The organic matter was studied by Rock-Eval pyrolysis and under the microscope in reflected non-polarized light and incident blue light. The results obtained show the presence of different types of organic ...
    nafta i gas, Rock-Eval, refleksija vitrinita, maceral, termička zrelost
    ... Middle and Late Jurassic strata are composed of oolithic limestones, reef and lagoonal shallow-water limestones, and dolomites (Natević and Petrović, 1970; Mirković, et al., 1974). Similar rocks of Cretaceous age cover larg- er parts of the study area (Mojićević and Laušević, 1965; Natević and Petrović ...
    ... Middle and Late Jurassic strata are composed of oolithic limestones, reef and lagoonal shallow-water limestones, and dolomites (Natevi¢ and Petrovi¢é, 1970; Mirkovic, et al., 1974). Similar rocks of Cretaceous age cover larg- er parts of the study area (Moji¢evi¢ and LauSevic, 1965; Natevi¢ and Petrovi¢ ...
    ... 1978. Petroleum Formation and Occurrence: A New Approach to Oil and Gas Exploration. Springer-Verlag, Berlin, 538 pp. Van Gijzel, P., 1981. Characterization and identi�cation of kerogen and bitumen and determination of thermal maturation by means of qualitative and quantitative microscopical ...

  • Atmospheric exposure vs burying: influences on damage intensity of built-in kersantite in the monument of the Small Staircase (Belgrade, Serbia)

    Nevenka Novaković, Predrag Dabić, Vesna Matović (2023)
    Proučavan je efekat „zatrpanog kamena“ na intenzitet procesa degradacije prisutnih na kersantitu koji je ugrađen u spomenik Malo stepenište. Istraživanja su vršena na uzorcima stene iz kamenoloma i na oštećenim kamenim blokovima ugrađenim u spomenik. Dok su neki delovi stepeništa bili pod zemljom 90 godina, većina kamenih elemenata je bila izložena različitim uslovima sredine i antropogenim uticajima. Urađeno je detaljno mapiranje trenutnog stanja spomenika kako bi se istražio uticaj “zatrpavanja” i kompleksne geometrije spomenika na tip propadanja i variranje ...
    Raspadanje, Indeks oštećenja, Zatrpavanje, Fizička svojstva, Kersantit

  • Properties of fly ash and slag from the power plants

    Miloš Šešlija, Aleksandra Rosić, Nebojša Radović, Milinko Vasić, Mitar Đogo, Milovan Jotić (2016)
    This paper describes the physical, chemical and mineral properties of ash and slag, which were taken from thermal power plants Nikola Tesla A, Nikola Tesla B, Kostolac A and Kostolac B. The knowledge of the mineralogical material composition is important because the type of minerals directly determines the properties of the fly ash and slag and their possible application. Laboratory tests showed that ash and slag samples consist of the following minerals: amorphous materials, quartz, feldspar, mullite, melilite, cristobalite, ...
    fly ash, slag, physical composition, chemical composition, mineral composition, X-ray diffraction method
    ... in the combustion process and other parts of non- combustible material. It falls through the latticed stokehole and is rapidly cooled and extinguished in water. The fly ash and slag landfills in Serbia occupy an area of 1639 ha and if they are under constant control and monitoring, significantly ...
    ... the Kostolac basin is also of Upper Miocene (Pontian) age and hosts five coal seams, namely Seam III (the oldest and deepest) and Seams II-a, II, I-a and I. Only coal seams III, II and I are (or have been) explored in the Drmno, Ćirikovac and Klenovnik open pits. The average thickness of coal Seam ...
    ... 451-2 and SRPS U. B1.018., and the pH value test was done according to SRPS H. C8.209. All the chemical tests on the fly ash and slag were done ac- cording to standards SRPS B.H8.359-369 and SRPS B.H8.327. Mineralogical sample properties of the fly ash and slag from PPNT A, PPNT B, PPKO A and PPKO ...

  • GIS Application Improvement with Multilingual Lexical and Terminological Resources

    Ranka Stanković, Ivan Obradović, Olivera Kitanović (2010)
    ... expands into only 10 combinations of an adjective form and a noun form: kvarcna stena AND kvarcne stene AND kvarcnoj steni AND kvarcnu stenu AND kvarcna steno AND kvarcnom stenom AND kvarcnoj steni AND kvarcnih stena AND kvarcnim stenama AND kvarcnima stenama thus disabling false retrieval ...
    ... geologic multilingual vocabulary and other lexical and terminological resources used. Two basic results are outlined: multilingual map annotation and improvement of queries for the GeolISS geodatabase. Multilingual labelling and annotation of maps for their graphic display and printing have been tested with ...
    ... data records and measurements, the basis for classification, interpretation and modeling of geological features. Spatial entity is treated as observation location and mapped/interpreted geological occurrence, and implemented in the geodatabase geometrically by points, lines and polygons. This ...

  • Optimization and Analysis of Drilling and Blasting Parameters Using O-Pitblast Software

    Stefan Milanović, Nikola Simić, Lazar Kričak, Milanka Negovanović, Nikola Đokić (2024)
    The development of modern technologies has enabled the application of specialized softwares in the field of mining through various segments and processes, including in works related to drilling and blasting. The application of specialized software for drilling and blasting with the use of modern technologies such as photogrammetry enabled more accurate data from the field for later processing. By processing data and creating a 3D model of the terrain for drilling and blasting works, it can obtain precise data, ...
    optimizacija, 3D model, bušenje, miniranje, O-Pitblast, softver

  • Development of terminological resources for expert knowledge: a case study in mining

    Ljiljana Kolonja, Ranka Stanković, Ivan Obradović, Olivera Kitanović, Aleksandar Cvjetić (2015)

  • Geochemical study of U, Th and REE mineralizations in Jurassic sediments and hydrochemical characterization of groundwaters in Eastern Serbia – Case study: Plavna area

    Jovan Kovačević, Maja Todorović, Marina Ćuk, Petar Papić (2016)
    jurski sedimenti, uran, torijum, elementi retkih zemalja, podzemna voda, istočna Srbija