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Упит dcterms_subject_txt:definition of criteria

2857 items

  • Design of a sucker rod pumping system

    Ana Ponoćko (2024)
    For a long time in the history of oil production, sucker rod pumps have been the first and in many cases the only choice when it comes to mechanical extraction methods. Proper selection of each individual element of the system enables optimization, which entails benefits in the form of increased efficiency and reduced costs. The first part of the paper presents the underground and surface equipment of the rod pump and describes the operation of the entire system. The ...
    sucker rod pump, fluid production, mechanical extraction methods,, Prosper, QROD, RODSTAR
    ... the lifting of sand, the application of this type of pump is recommended because the pump body seals in the upper part with its seating, preventing the accumulation of sand between the tubing and the cylinder in case of a pump shutdown. On the other hand, a drawback of this type of top seating ...
    ... purpose of this paper is to introduce the basic components of the pump, its operation, and improvements to its performance through the application of a double-acting valve. The first part of the paper presents the underground and surface equipment of the rod pump and describes the operation of the ...
    ... Elastic Force: Due to the elasticity of the rod strings and the weight of the fluid. 4. Inertial Forces: Resulting from the movement of the mass of the rod strings, pump plunger, and the weight of the fluid. 5. Frictional Forces: Including: – Friction of Rod String Joints: Against the tubing ...

  • Introduction to special section: Characterization of hydrocarbon and geothermal resource potential and carbon sequestration opportunities of the Pannonian Basin

    Balázs Németh, Gábor Tari, Gábor Bada, Dejan Radivojević, Bruno Tomljenovic, Csaba Krézsek (2018)
    нафтна геологија, геотермална енергија, Панонски басен

  • Extreme Rainfall Event and Its Aftermath Analysis—IPL 210 Project Progress Report

    Biljana Abolmasov, Mileva Samardžić Petrović, Ranka Stanković, Miloš Marjanović, Jelka Krušić, Uroš Đurić (2021)
    Landslides, Extreme precipitation, Data analysis, IPL project report

  • Age of the Jurassic hemipelagic sediments from the Ljubiš area (Zlatibor Mt., SW Serbia)

    Nikita Bragin, Nevenka Đerić (2020)
    Radiolaria, Dinarides, Jurassic, stratigraphy, Serbia
    ... Theocapsomella sp. R Figure 4. A lithological column of the lower part of the Djokov Potok section (Ljubiš Formation). The numbers of units are shown to the left of the column. Positions of samples with radiolarians are indicated on the right of the column by arrows. 1 – radiolarites and mudstones; ...
    ... Formation on the western slope of Vis Mountain. According to GAWLICK et al. (2017) the preserved part of the Ljubiš basin represents a more proximal part of the basin and the thickness of this basin fill is at least 400 m. In the currently uninvestigated most proximal parts of this basin the authors expected ...
    ... important for the reconstruction of tectonic motion and the arrangement of palaeo­oceanic basins and continental blocks. Due to the highly complicated structure of this territory, each palaeontological da­ tum from radiolarite deposits and from carbonate clasts of the intercalated turbidites is ...

  • Geochemical evaluation of dolostone deposits in Montenegro: Implications for potential industrial applications

    Darko Bozovic, Vladimir Simic, Dragan Radulovic, Slobodan Radusinovic, Vesna Matovic, Anja Terzic (2024)
    This study presents a unique model for assessing the dependability of continuous parts of combined systems in open-pit mining through the application of fuzzy logic. Continuous sub-systems as part of the combined system of coal exploitation in surface mines have the basic function of ensuring safe operation, high capacity with high reliability, and low costs. These subsystems are usually part of the thermal power plant’s coal supply system and ensure stable fuel supply. The model integrates various independent partial ...
    примарне сировине, минералогија, физичко-механичка својства, технолошка својства, наука о материјалима

  • Project BEWARE—Landslide Post-disaster Relief Activities for Local Communities in Serbia

    Biljana Abolmasov, Dobrica Damjanović, Miloš Marjanović, Ranka Stanković, Velizar Nikolić, Sandra Nedeljković, Žarko Petrović (2017)
    ... ion of landslide data and training of municipalities for its monitoring, nicknamed BEWARE (BEyond landslide aWAREness) was implemented by the Geological Survey of Serbia, and the University of Belgrade Faculty of Mining and Geology. The Project partners were UNDP Office in Serbia, Ministry of Mining ...
    ... project was implemented by the Geological Survey of Serbia, and the University of Belgrade Faculty of Mining and Geology. The Project partners were Ministry of Mining and Energy, Government Office for Reconstruction and Flood Relief of the Republic of Serbia and UNDP Office in Serbia. Project started ...
    ... and GovernmentOffice for Reconstruction and FloodRelief of the Republic of Serbia. Project was funded by People of Japan. Overall aim of BEWARE project was to standardize post-event landslide database and closely involve local community of 27 municipalities affected byMay 2014 flooding and landslides ...

  • Failure Estimation of the Majdanpek Open Pit East Face Based on Inverse Velocity Model

    Miloš Marjanović, Stefan Milanović, Nikola Simić, Lazar Kričak (2024)
    The Majdanpek open pit mine south district is currently active mining prospect of copper ore exploitation in eastern Serbia. Its depth is approaching the termination depth and occurrences of large-scale instabilities and global instability of the final pit slope is possible. These can generate catastrophic mass movement inside an area that encloses a regional road route and the Pek River bed which is channelled along the outer contour of the pit. The displacements that were noted in early 2023, in the ...
    displacement, survey, inverse velocity, open pit

  • Extraction of Bilingual Terminology Using Graphs, Dictionaries and GIZA++

    Branislava Šandrih, Ranka Stanković (2020)
    U nauci, industriji i mnogim istraživačkim oblastima, terminologija se brzo razvija. Najčešće, jezik koji je „lingua franca“ za većinu ovih oblasti je engleski. Kao posledica toga, za mnoga polja termini domena su koncipirani na engleskom, a kasnije se prevode na druge jezike. U ovom radu predstavljamo pristup za automatsko izdvajanje dvojezične terminologije za englesko-srpski jezički par koji se oslanja na usaglašeni dvojezični korpus domena, ekstraktor terminologije za ciljni jezik i alat za usklađivanje delova. Ispitujemo performanse metode na domenu ...
    ekstrakcija terminologije, validacija terminologije, GIZA++, grafovi, Unitex, klasifikacija teksta
    ... (LIS-corpus+); 2. The list of domain terms for the source language (Input ii) is (a) the source language part of LIS-dict including SWTs; (b) the output of the extractor Eng-TE applied to the source language part of the aligned input corpus; 3. The extraction of the set of MWTs in the target language ...
    ... problematic characteristics of this expression are (1) syntactic anomaly of the part-of-speech (POS) sequence preposition + con- junction + adjective, (2) non-compositionality: semantics of the whole that is unrelated to the individual pieces, (3) non-substitutability of synonym words (e.g., by and big) ...
    ... 310 x x Additional filtering of results obtained by GIZA++11 I Number of the aligned chunks after initial filtering using English terms (Processing ii): (S(align.chunk) ∼ S(term)), where the list of English terms depends on the choice of parameter 1 (the English part of LIS- dict or obtained from the ...

  • Topic Modeling of the SrpELTeC Corpus: A Comparison of NMF, LDA, and BERTopic

    Teodora Mihajlov, Milica Ikonić Nešić, Ranka Stanković, Olivera Kitanović (2024)
    Modeliranje tema je efikasan način da se dobije uvid u velike količine podataka. Neki od najčešće korišćenih metoda za modeliranje tema su Latentna Dirihleova alokacija (LDA) i faktorizacija nenegativne matrice (NMF). Međutim, sa porastom modela samopažnje i unapred obučenih jezičkih modela, pojavili su se novi načini za ekstrakcju tema. BERTopic predstavlja novi pristup modeliranju tema. U ovom radu smo uporedili performanse LDA, NMF i BERTopic na književnim tekstovima na srpskom, merenjem koherentnosti tema i raznovrsnosti tema, kao i kvalitativnom ...
    jezički modeli, LDA, modeliranje tema, BERT, BERTopic

  • Mitigating hydrate formation in onshore gas wells: A case study on optimization techniques and prevention

    Milica Ješić, Bojan Martinović, Stefan Stančić, Miroslav Crnogorac, Dušan Danilović (2023)
    Gas wells, particularly those situated onshore, play a vital role in the global energy sector by supplying a significant portion of natural gas. However, operational challenges, notably gas hydrate formation, pose substantial issues, leading to complications such as flowline blockages and unexpected well shutdowns. Gas hydrates, crystalline structures resembling ice, ...
    Gas Well, Gas Hydrate Formation, Well Modeling, Well Performance Optimization, Choke Position Adjustments, Methanol Injection

  • Reconstruction of the Tethys' waning in the Balkans: New insights from Upper Cretaceous igneous formations and zircon provenance data

    Dejan Prelević, Kristijan Sokol, Ana Mladenović, Violeta Gajić, Vladica Cvetković (2024)
    geochronology, zircon, provenance
    ... Congress of Geologists of the Republic of North Macedonia RECONSTRUCTION OF THE TETHYS' WANING IN THE BALKANS: NEW INSIGHTS FROM UPPER-CRETACEOUS IGNEOUS FORMATIONS AND ZIRCON PROVENANCE DATA Dejan Prelević, Kristijan Sokol, Ana Mladenović, Violeta Gajić, Vladica Cvetković University of Belgrade ...
    ... histories of these regions. The presence of Permotriassic zircons in thc Upper Cretaceous sediments of the Sava-Vardar Zone and thcir absence further cast challenge the notion of a vast Sava (Tethys) Ocean during the Cretaceous. ACKNOWLEDGEMENT This research is financed by the Science Fund of Serbia ...
    ... [ДР РГФ] Reconstruction of the Tethys' waning in the Balkans: New insights from Upper Cretaceous igneous formations and zircon provenance data | Dejan Prelević, Kristijan Sokol, Ana Mladenović, Violeta Gajić, Vladica Cvetković | Fifth Congress of Geologists of the Republic of North Macedonia | 2024 | ...

  • Machine Learning and Deep Neural Network-Based Lemmatization and Morphosyntactic Tagging for Serbian

    Ranka Stanković, Branislava Šandrih, Cvetana Krstev, Miloš Utvić, Mihailo Škorić (2020)
    The training of new tagger models for Serbian is primarily motivated by the enhancement of the existing tagset with the grammatical category of a gender. The harmonization of resources that were manually annotated within different projects over a long period of time was an important task, enabled by the development of tools that support partial automation. The supporting tools take into account different taggers and tagsets. This paper focuses on TreeTagger and spaCy taggers, and the annotation schema alignment ...
    Part-of-Speech tagging, lemmatization, corpus, evaluation, Serbian, morphological dictionary
    ... previously derived from then latest version of SMD (Utvić, 2011). TT11 tagset consists of 16 tags, most of them acquired from SMD as labels for major Parts-of-Speech (Table 3 column T11). TT11 was used to annotate SrpKor2013, current version of SrpKor – Corpus of Contemporary Serbian.4 As pointed out ...
    ... primarily motivated by the enhancement of the existing tagset with the grammatical category of a gender. The harmonization of resources that were manually annotated within different projects over a long period of time was an important task, enabled by the development of tools that support partial automation ...
    ... dictionaries, MULTEXT-East and Universal Part-of-Speech tagset. The trained models will be used to publish the new version of the Corpus of Contemporary Serbian as well as the Serbian literary corpus. The performance of developed taggers were compared and the impact of training set size was investigated, which ...

  • Digital Library From A Domain Of Criminalistics As A Foundation For A Forensic Text Analysis

    Dalibor Vorkapić, Aleksandra Tomašević, Miljana Mladenović, Ranka Stanković, Nikola Vulović (2017)
    U ovom radu predstavljen je model koji omogućava prikupljanje, pripremu, opis metapodataka, upravljanje i eksploataciju, uključujući pretragu punog teksta dokumenata iz domena kriminalistike napisanih na srpskom jeziku. Predloženi pristup primenjuje se na veb portalu koji sakuplja različite tekstove nastale iz časopisa Akademije za kriminalistiku i policijske studije, Krivičnog zakona Srbije, konferencija „Tara“ i „Reiss“, kao i iz nekih doktorskih disertacija vezanih za ovu oblast istraživanje. Nakon obrade teksta, korpus koji sadrži preko 5500 stranica običnog teksta, kreiran je i ...
    Omeka, Wordnet, pretraga punog teksta, morfološka i semantička pretraga teksta, proširenje upita
    ... University of Belgrade – Faculty of Mining and Geology Aleksandra Tomašević University of Belgrade – Faculty of Mining and Geology Miljana Mladenović PhD eVox Solutions Ranka Stanković PhD University of Belgrade – Faculty of Mining and Geology Nikola Vulović University of Belgrade – Faculty ...
    ... texts derived from journals of The Academy of Criminalistics and Police Studies, Criminal code of Serbia, the “Tara” and “Reiss” conferences, and from some of PhD dissertations related to this field of research. After text processing, a corpus containing over 5500 pages of plain text is created and ...
    ... LINGUISTICS The linguistic study of forensic texts is a part of the field of Natural Language Processing, which includes text types classification and syntax and semantic analysis of texts written in a natural language. Various texts are subject of the study: Acts of Parliament (or other law-making ...

  • Advantages and challenges in presenting mathematical content using EDX platform

    Marija Radojičić, Ivan Obradović, Ranka Stanković, Olivera Kitanović, Roberto Linzalone (2016)
    ... additional option in Termi is the possibility of creating an export link to a term, which can be embedded in an html page. This provides for establishing a connection between a term within the course and its definition in Termi dictionary. From the user’s point of view this addition to mathematical ...
    ... synonyms, hyperonyms, hyponyms abbreviations, description and bibliography. Image 7: Pop up window with definition of term 6. DISCUSSIONS AND SUGGESTIONS Despite the advantages of OER courses their usage is still at a low level in Serbia. There are not many OER courses in higher education ...
    ... content within the course can be very useful as some kind of reminder for specific or infrequent mathematical terms. User can open a pop up window with definition from Termi resources by dragging the cursor over the term in the course (Image 7). Also, there is a link which allows the user ...

  • 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

  • Molecular and Isotope Composition of Biomarkers in Immature Oil Shale and its Liquid Pyrolysis Products (Open and Closed System)

    Gordana Gajica, Aleksandra Šajnovic, Jan Schwarzbauer, Aleksandar Kostić, Branimir Jovančićević, Ksenija Stojanović (2021)
    The molecular and isotopic composition of biomarkers in initial bitumen isolated from raw immature oil shale samples from the Lower Miocene Aleksinac Basin (Serbia) and liquid products (LPs) obtained by pyrolysis in open (OS) and closed systems (CS) are studied. The influence of pyrolysis type and variations of kerogen type on biomarkers composition and their isotopic signatures in LPs is determined. The molecular composition of the LPs from the OS pyrolysis is very similar to those in initial bitumen, independently ...
    ... obtained by the OS and the CS pyrolysis. The distribution of n-alkanes (C14–C35) in LPs differs from those in bitumen of raw samples, which is reflected through the increase of lower homologues. In addition to the fact that the distribution of n-alkanes depends on maturity changes that particularly ...
    ... material. The prevalence of lower homologues in LPs is consistent with the predominantly algal origin of organic matter (OM) (Gajica et al., 2017). The n-alkane distributions in all LPs are characterized by uniform abundances of odd and even homologues, resulting in a reduction of the CPI values (~ 1) ...
    ... initial bitumen of both raw samples, the pristane/phytane (Pr/Ph) ratio is similar (< 0.4). In LPs from the OS the values of Pr/Ph are 1.23 and 1.74. That might be explained by a preferred release of pristane than phytane from isoprenoid moieties during slight thermal treatment of kerogen (Larter ...

  • Curcumin nanonization using an alternative small-scale production unit: selection of proper stabilizer applying basic physicochemical consideration and biological activity assessment of nanocrystals

    Ines Nikolić, Jelena Antić-Stanković, Dragana Božić, Danijela Ranđelović, Bojan Marković, Dominique Jasmin Lunter, Aleksandar Kremenović, Miroslav Savić, Snežana Savić (2020)
    As the number of poorly soluble drugs is increasing, nanocrystals have become very interesting due to wide range of application possibilities. Curcumin was used as a model active ingredient in this work. Even though it has many proven positive effects, due to its physicochemical issues, its possibilities have not been fully exploited. The goal of this work was to select optimal conditions for a top-down method for curcumin nanosuspension production, and to perform their comprehensive characterization applying complementary methodologies: ...
    nanocrystal, curcumin, top-down method, wetball milling

  • 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
    ... B.H8.317:1988, (1988): Methods of analysis of coal and coke ­ Determination of volatile matter content.– Institute for Standardization of Serbia, Belgrade, Serbia, 6 p. (in Serbian). SRPS B.H8.318:1972, (1972): Methods of analysis of coal and coke ­ Determination of gross calorific value by the ...
    ... central part of Serbia. The total thickness of Neogene sediments is estimated at 1000 m. The Neogene units of the Kovin deposit Figure 1. Location of the Kovin deposit (a, b) and simplified geological map (c) of the Kovin deposit with sample locations (modified after Basic Geologic Map of Ser- bia, section ...
    ... lignites. A large proportion of the Fe­oxide/hydroxides in the Kovin lignite samp­ les (Fig. 4h) is probably the result of the weathering of iron­rich minerals such as pyrite and siderite. A small proportion of these minerals might also be of detrital origin. Limonite (a mixture of goethite, lepidocrocite ...

  • Mapping and classifying large deformation from digital imagery: application to analogue models of lithosphere deformation

    Taco Broerse, Nemanja Krstekanić, Cor Kasbergen, Ernst Willingshofer (2021)
    kontinentalna tektonika: kompresija, kontinentalna tektonika: ekstenzija, kontinentalna tektonika: transkurentni i transformni rasedi, pukotine, rasedi, zone snažnih deformacija, kinematika deformacija kore i omotača, teorijska mehanika, modelovanje
    ... irrespective of the amount of deformation (Fig. 7). For oblique deformation this ratio only slightly changes with increasing deformation, but for our qualitative measure of strain type we argue this is only a minor issue. Our definition of strain type provides the same qualitative characterization of deformation ...
    ... nt fields requires a prior definition of fault orientations. As such this method works only when the spatial derivative of the displacement field is determined perpendicular to a fault. Hence, due to current unavailability of methods that allow a unique decomposition of deformation into a shear and ...
    ... each fault to obtain a meaningful decomposition of deformation. Namely, the QR decomposition is possible in any chosen reference axis orientation (Freed & Srinivasa 2015). This implies the development of a spatially and temporally varying definition of the reference axes, and we do not pursue that in ...

  • Application of ERT in the study of debris-flow source area: Case study Selanac debris flow

    Dragana Đurić, Jelka Krušić, Biljana Abolmasov (2021)