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2840 items
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Mitigating hydrate formation in onshore gas wells: A case study on optimization techniques and prevention
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 InjectionMilica Ješić, Bojan Martinović, Stefan Stančić, Miroslav Crnogorac, Dušan Danilović. "Mitigating hydrate formation in onshore gas wells: A case study on optimization techniques and prevention" in Underground Mining Engineering, Beograd : Rudarsko-geološki fakultet (2023)
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Machine Learning and Deep Neural Network-Based Lemmatization and Morphosyntactic Tagging for Serbian
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 ...... 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 ...Ranka Stanković, Branislava Šandrih, Cvetana Krstev, Miloš Utvić, Mihailo Škorić. "Machine Learning and Deep Neural Network-Based Lemmatization and Morphosyntactic Tagging for Serbian" in Proceedings of the 12th Language Resources and Evaluation Conference, May Year: 2020, Marseille, France, European Language Resources Association (2020)
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Digital Library From A Domain Of Criminalistics As A Foundation For A Forensic Text Analysis
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 ...... 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 ...Dalibor Vorkapić, Aleksandra Tomašević, Miljana Mladenović, Ranka Stanković, Nikola Vulović. "Digital Library From A Domain Of Criminalistics As A Foundation For A Forensic Text Analysis" in International Scientific Conference “Archibald Reiss Days” Thematic Conference Proceedings Of International Significance, Belgrade, 7-9 November 2017, Academy Of Criminalistic And Police Studies Belgrade (2017)
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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 ...Gordana Gajica, Aleksandra Šajnovic, Jan Schwarzbauer, Aleksandar Kostić, Branimir Jovančićević, Ksenija Stojanović. "Molecular and Isotope Composition of Biomarkers in Immature Oil Shale and its Liquid Pyrolysis Products (Open and Closed System)" in 30th International Meeting on Organic Geochemistry (IMOG 2021), European Association of Geoscientists & Engineers (2021). https://doi.org/10.3997/2214-4609.202134040
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Advantages and challenges in presenting mathematical content using EDX platform
... PLATFORM MARIJA RADOJIČIĆ University of Belgrade, Faculty of Mining and Geology, marija.radojicic@rgf.bg.ac.rs IVAN OBRADOVIĆ University of Belgrade, Faculty of Mining and Geology, ivan.obradovic@rgf.bg.ac.rs RANKA STANKOVIĆ University of Belgrade, Faculty of Mining and Geology, ranka.stankovic@rgf ...
... in Python. All these types of task work with edX tags which annotate the type of content: a question, a response, a possible response and etc. Also there are possibilities for customizing the weight of each problem, number of attempts, feedbacks, randomization of offered answers and time between ...
... clear structure of course material, which is in line with the didactic principle of systematization and gradualism in the teaching process. Didactical principle of awareness within the teaching process is represented through the tasks, where activity of users and some kind of interaction between ...Marija Radojičić, Ivan Obradović, Ranka Stanković, Olivera Kitanović, Roberto Linzalone. "Advantages and challenges in presenting mathematical content using EDX platform" in The Seventh International Conference on e-Learning (eLearning-2016), Belgrade : Metropolitan University (2016)
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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, PyrophylliteBorislav Vasić, Radoš Gajić, Ivana Milošević, Žarko Medić, Marina Blagojev, Marko Opačić, Aleksandar Kremenović, Dejan Lazić. "Natural two-dimensional pyrophyllite: Nanoscale lubricant, electrical insulator and easily-machinable material" in Applied Surface Science, Elsevier BV (2022). https://doi.org/10.1016/j.apsusc.2022.155114
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Serbian NER&Beyond: The Archaic and the Modern Intertwinned
U ovom radu predstavljamo srpski književni korpus koji se razvija pod okriljem COST Akcije „Distant Reading for European Literary History” CA16204. Koristeći ovaj korpus romana napisanih pre više od jednog veka, razvili smo i učinili javno dostupnim Sistem za prepoznavanje imenovanih entiteta (NER) obučen da prepozna 7 različitih tipova imenovanih entiteta, sa konvolucionom neuronskom mrežom (CNN), koja ima F1 rezultat od ≈91% na test skupu podataka. Ovaj model je dalje ocenjen na posebnom skupu podataka za evaluaciju. Završavamo poređenje ...... University of Belgrade Faculty of Philology branislava.sandrih@fil.bg.ac.rs Ranka Stanković University of Belgrade Faculty of Mining and Geology ranka.stankovic@rgf.bg.ac.rs Cvetana Krstev University of Belgrade Faculty of Philology cvetana@matf.bg.ac.rs Milica Ikonić Nešić University of Belgrade ...
... the scope of the COST action CA16204 “Distant Reading for European Literary History”. We thank the stu- dents of the Department of Library and Infor- mation Sciences, Faculty of Philology, master students of Social Sciences and Computing at Multidisciplinary Graduate Studies and PhD students of Intelligent ...
... Proceedings of the 6th Named Entity Workshop, pages 21–27. Cvetana Krstev. 2008. Processing of Serbian. Au- tomata, Texts and Electronic Dictionaries. Fa- culty of Philology of the University of Belgrade. Cvetana Krstev, Jelena Jaćimović, Branislava Šandrih, and Ranka Stanković. 2019. Ana- lysis of the first ...Branislava Šandrih Todorović, Cvetana Krstev, Ranka Stanković, Milica Ikonić Nešić. "Serbian NER&Beyond: The Archaic and the Modern Intertwinned" in Proceedings of the Conference Recent Advances in Natural Language Processing - Deep Learning for Natural Language Processing Methods and Applications, INCOMA Ltd. Shoumen, BULGARIA (2021). https://doi.org/10.26615/978-954-452-072-4_141
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Development of integrated fuzzy model for mine management optimization
Miodrag Čelebić, Sanja Bajić, Dragoljub Bajić, Dejan Stevanović, Duško Torbica, Vladimir Malbašić (2023)... deposit L-29C of the Bešpelj mine near Jajce in the Republic of Serbia, Bosnia and Herzegovina, which is the focus of the paper. Study area and geology. The Bešpelj bauxite mine is located on a spacious karst plateau, on the right bank of the Vrbas River. It is at a beeline distance of 10 km from ...
... comparison of all alternatives relative to set criteria, as well as calculated weights. 'The final scores of al] the alternatives, in the form of triangular fuzzy numbers, were calculated under Step 5, based on Eq. 5, and then the final “weights” of the alternatives were derived in the form of non-fuzzy ...
... complexity of ore deposit structures, given that a large number of elements of the decision- making model are often uncertain and, in most cases, it is not possible to determine exact numerical values for comparing, decisions. The proposed method makes use of a logical approach of the expert to ...Miodrag Čelebić, Sanja Bajić, Dragoljub Bajić, Dejan Stevanović, Duško Torbica, Vladimir Malbašić. "Development of integrated fuzzy model for mine management optimization" in Comptes rendus de l'Académie Bulgare des Sciences (2023)
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Application of ERT in the study of debris-flow source area: Case study Selanac debris flow
Dragana Đurić, Jelka Krušić, Biljana Abolmasov. "Application of ERT in the study of debris-flow source area: Case study Selanac debris flow" in 11th Congress of the Balkan Geophysical Society, Volume 2021, Online-Romania, 10 -14. Oct 2021,, European Association of Geoscientists & Engineers (2021). https://doi.org/10.3997/2214-4609.202149BGS15
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Bridging Computational Lexicography and Corpus Linguistics: A Query Extension for OntoLex-FrAC
OntoLex, dominantni standard zajednice za mašinski čitljive leksičke resurse u kontekstu RDF-a, Linked Data i tehnologija Semantičkog veba, trenutno se proširuje sa posebnim modulom za Frekvencije, Primere i Informacije zasnovane na Korpusu (OntoLex-FrAC). Predlažemo novi komponent za OntoLex-FrAC, koji se bavi inkorporacijom korpusnih upita za (a) povezivanje rečnika sa korpusnim mašinama, (b) omogućavanje RDF baziranih web servisa da dinamički razmenjuju korpusne upite i podatke odgovora, i (c) korišćenje konvencionalnih upitačkih jezika za formalizaciju unutrašnje strukture kolokacija, skica reči i ...standardizacija, digitalna leksikografija, OntoLex, upiti korpusa, povezani podaci, Lingvistički povezani otvoreni podaciChristian Chiarcos, Ranka Stanković, Maxim Ionov, Gilles Sérasset. "Bridging Computational Lexicography and Corpus Linguistics: A Query Extension for OntoLex-FrAC" in Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024), Turin, 20-25 May 2024, LREC (2024)
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Karst aquifer impact on the formation of surface runoff: case study of the Resava River catchment, Serbia
Marina Mitrašinović, Vesna Ristić Vakanjac, Veljko Marinović, Saša Milanović, Ljiljana Vasić, Dušan Polomčić (2022)The paper compares the flow regimes of the Resava River at the gauging stations of the Manasija Monastery (upper course) and the town of Svilajnac (lower course). The hydrological analysis encompasses a multiyear period of monitoring (1982–2020). The water budget and baseflow index are assessed for the catchment areas monitored by the Svilajnac station (683 km2) and the Manasija Monastery station (358k m2), considering the overall monitoring period and characteristic years. The results indicate that the specific runoff in ...... the ratio of mcean annual discharges is 1:1.25 (2001) and even lower in 2018 (1:1.15). The ratio of the catchment areas covered by the gauging stations is 1:1.75. This sug- gests that most of the discharge of the Resava River is formed in the upper catchment (Figs. 1a,b). In the case of the char ...
... Resava catchment is in the northern part of East- ern Serbia, between the Velika Morava River and the slopes of the Kučaj-Beljanica Mountains. The Resava River originates at the junction of the Zlots- ka River and the Karapandžin Creek at an altıtude of 668 m. It is a major right-side tributary ...
... clevation is 93 m. The upper catchment of the Resava is a composite valley comprised of gorg- es, ravines, and canyons (mostly karst), which cn- ters the Velika Morava River Basin near the town of Despotovac (Paunković, 1953). The upper Resava runs from the village of Strmosten in the west and ('C ...Marina Mitrašinović, Vesna Ristić Vakanjac, Veljko Marinović, Saša Milanović, Ljiljana Vasić, Dušan Polomčić. "Karst aquifer impact on the formation of surface runoff: case study of the Resava River catchment, Serbia" in National Conference with International Participation “GEOSCIENCES 2022”, Sofia : Bulgarian geological society (2022)
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Hydraulic impact of pressure transients from water conveyance tunnel on the complex hydrogeological system: A case study HPP
Tunel pod pritiskom, Unutrašnji pijezometri, Tranzijenti pritiska, Karstna izdan, Pukotinska izdan, Hidraulički odziv... phenomena: water hammer – WH and water mass oscillation – WMO (Fig. 3). The elastic properties of Water lead to the appearance of a hydraulic transient – WH, in the zone of appearance of the high-pressure part of the tunnel and are related to the surge tank. The surge tank attenuates the pressure amplitude ...
... dr.rgf.bg.ac.rs The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs Journal of Hydrology | Volume 644, November 2024 ...
... are made of unreinforced concrete lining with grouting to provide stability and prevent permeability. Long-term operation of HPP can cause cracks in the tunnel lining in circumstances of high internal pressure when the tangential stress at the inner surface exceeds the tensile strength of concrete ...Igor Jemcov, Maja Todorović, Aleksandar Jemcov, Marina Ćuk Đurović. "Hydraulic impact of pressure transients from water conveyance tunnel on the complex hydrogeological system: A case study HPP" in Journal of Hydrology, Pirot, 2024, Elsevier BV (2024). https://doi.org/10.1016/j.jhydrol.2024.132068
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Pre-failure deformation monitoring as rockfall prediction tool
... Vranić2 1University of Belgrade, Faculty of Mining and Geology, Đušina 7, Belgrade, Serbia 2University of Belgrade, Faculty of Civil Engineering, Bul. Kralja Aleksandra 73, Belgrade, Serbia milos.marjanovic@rgf.bg.ac.rs Abstract. In this article, we are elaborating an example of predictive rockfall ...
... Figure 1. Location (left), appearance of the slope (middle), and plan of scanning disposition (right). it is beyond the scope of this article to overview the current research and practice state-of-the-art in the field of LiDAR-based monitoring. Instead, some milestone contributions ...
... site Location of interest is positioned along IB22 highway, some 5 km to the south of the town of Ljig. It is a medium-sized rock slope, about 30 m high and 60 m long, with average slope of 60°, facing SSE (figure 1). It is a road cut engineered during 70’s due to re-routing of an earlier flood-prone ...Miloš Marjanović, Biljana Abolmasov, Zoran Berisavljević, Marko Pejić, Petko Vranić. "Pre-failure deformation monitoring as rockfall prediction tool" in IOP Conference Series: Earth and Environmental Science, IOP Publishing (2021). https://doi.org/10.1088/1755-1315/833/1/012197
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Quantitative analysis of syllable properties in Croatian, Serbian, Russian, and Ukrainian
Biljana Rujević, Marija Kaplar, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Jan Mačutek (2021)Biljana Rujević, Marija Kaplar, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Jan Mačutek. "Quantitative analysis of syllable properties in Croatian, Serbian, Russian, and Ukrainian" in Language and Text: Data, models, information and applications, John Benjamins Publishing Company (2021). https://doi.org/10.1075/cilt.356.04ruj
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Cytotoxic activity of tetradentate Schiff Base Copper(II) complexes
Istraživanje kompleksa bakra kao potencijalnih antikancerogenih agenasa nudi ohrabrujuće perspektive u odnosu na komplekse platine (II) računajući na smanjenu toksičnost, novi mehanizam delovanja, različit spektar aktivnosti i perspektivu neunakrsne rezistencije. Kompleksi Šifovih baza bakra(II) koji sadrže tetradentatne ligande acac2en tipa (acac2en (1); tfacac2en (3), acactfacacen (4), acacphacacen (6)) pokazali su važnu antioksidativnu aktivnost, visok potencijal za interakciju sa HSA i DNK, u prethodnim studijama. Zbog toga je bilo interesantno ispitati i uporediti potencijal antikancerogene aktivnosti in vitro, u odnosu ...Nevenka Gligorijević, Aleksandar Mijatović, Sandra Aranđelović, Rada Baošić . "Cytotoxic activity of tetradentate Schiff Base Copper(II) complexes" in The European Association for Cancer Research 2021 , eacr2021.org/sponsorship (2021)
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Understanding the effect of synthesis and sintering temperature on the functional properties of barium titanate/cobalt ferrite composites
Marija Šuljagić, Aleksandar Kremenović, Ivan Petronijević, Adis Džunuzović, Miljana Mirković, Vladimir Pavlović, Ljubica Anđelković (2023)To investigate the effect of synthesis procedure and sintering temperature on the functional properties of perovskite/spinel ceramics, BaTiO3/CoFe2O4 composites were prepared by thermal decomposition, coprecipitation, and microemulsion method, and sintered at 1150°C and 1300°C. The phase composition and morphology of as-prepared powders as well as sintered ceramics were thoroughly examined by X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM) coupled with electron dispersive spectroscopy (EDS). The dielectric and ferroelectric measurements were performed in detail. Generally, the ...Marija Šuljagić, Aleksandar Kremenović, Ivan Petronijević, Adis Džunuzović, Miljana Mirković, Vladimir Pavlović, Ljubica Anđelković. "Understanding the effect of synthesis and sintering temperature on the functional properties of barium titanate/cobalt ferrite composites" in Science of Sintering (2023). https://doi.org/10.2298/SOS220512013S
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On the distribution modulo 1 of the sum of powers of a Salem number
Dragan Stankov (2016)It is well known that the sequence of powers of a Salem number θ, modulo 1, is dense in the unit interval, but is not uniformly distributed. Generalizing a result of Dupain, we determine, explicitly, the repartition function of the sequence , where P is a polynomial with integer coefficients and θ is quartic. Also, we consider some examples to illustrate the method of determination.Algebraic integer, the house of algebraic integer, maximal modulus, reciprocal polynomial, primitive polynomial, Schinzel-Zassenhaus conjecture, Mahler measure, method of least squares, cyclotomic polynomialsDragan Stankov. "On the distribution modulo 1 of the sum of powers of a Salem number" in Comptes rendus Mathematique (2016). https://doi.org/10.1016/j.crma.2016.03.012
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Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae
Hans Peter Nytoft, Geir Kildahl-Andersen, Sofie Lindström, Frode Rise, Achim Bechtel, Danica Mitrović, Nataša Đoković, Dragana Životić, Ksenija A. Stojanović (2019)Two previously unidentified dehydroabietane isomers were isolated from Miocene Serbian lignite and Rhaetian (Late Triassic) coaly mudstones from South Sweden and characterized using NMRspectroscopy as cis- and trans-dehydroicetexane. Both have a 9(10?20)-abeo-abietane or icetexane skeleton, consisting of a 6-7-6 tricyclic framework with seven carbons in ring B instead of the usual six in common diterpanes of the abietane-type. Dehydroicetexanes can be detected using GC-MS-MS in m/z 270?146 chromatograms without interference from dehydroabietane or other isomers. Dehydroicetexanes are often abundant ...Hans Peter Nytoft, Geir Kildahl-Andersen, Sofie Lindström, Frode Rise, Achim Bechtel, Danica Mitrović, Nataša Đoković, Dragana Životić, Ksenija A. Stojanović. "Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae" in Organic Geochemistry, Elsevier BV (2019). https://doi.org/10.1016/j.orggeochem.2019.01.001
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XRD dertermination od hydrothermal phases related to epithermal mineralization in the Čukaru Peki deposit
Dragana Bosić, Vladica Cvetković, Miodrag Banješević, Kristina Šarić. "XRD dertermination od hydrothermal phases related to epithermal mineralization in the Čukaru Peki deposit" in V Congress of Geologists of Republic of Macedonia ": “Geology in a changing world”, Makedonsko geološko društvo (2024)
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Overview of the hydrogeological investigations of recently discovered world class deposits in Serbia
Europe industry has growing concerns on availability of the raw materials. To address this challenge, the European Commission has created a list of critical raw materials for the EU, launched EIT Raw Materials initiative, and continuously support research projects (like INTRAW, UNEXMIN etc.) with the aim of reducing the dependency and meeting growing demands. In the last 15 years Serbia is experiencing new bust in geological exploration of mineral deposits. Currently 167 exploration licenses are active, covering approximately 6000 ...Nebojša Atanacković, Vladimir Živanović, Veselin Dragišić, Sava Magazinović. "Overview of the hydrogeological investigations of recently discovered world class deposits in Serbia" in Proceedings of IAH2019, the 46th Annual Congress of the International Associaton of Hydrogeologists, Málaga (Spain), September 22-27, 2019, International Association of Hydrogeologists (IAH) (2019)