Претрага
727 items
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Rangiranja bagera za njihovu revitalizaciju primenom višekriterijumske analize
Obzirom da je na našim površinskim kopovima trenutno u eksploataciji veći broj rotornih bagera sa sličnim tehničkim karakteristikama i približno istom starošću postavlja se pitanje kako rangirati bagere, i kojim redom da se izvrši njihova revitalizacija. Za ocenu stanja i rangiranje ovako velikog broja bagera najpogodnije se pokazalo korišćenje višekriterijumskih metoda sa višeatributnom ocenom, odnosno bodovanje referentnih indikatora stanja bagera na osnovu ekspertske ocene. U ovom radu prikazan je metodološki pristup koji je korišćen prilikom izrade Studije «Produžetak radnog ...... feasibility study: Increasing of equipment work life in EPS open pit mines. KEY WORDS: BUCKET WHEEL EXCAVATORS, REVITALIZATION, RANKING, MULTICRITERIA ANALYSIS 1. UVOD Na svim površinskim kopovima u Srbiji se primenjuje kontinualna tehnika eksploatacije, tj. primena BTO sistema na otkopavanju jalovine ...Ivan Obradović, Dragan Ignjatović, Ranka Stanković, Ljiljana Ivković. "Rangiranja bagera za njihovu revitalizaciju primenom višekriterijumske analize" in MAREN 2006, Međunarodni simpozijum Mehanizacija i automatizacija u rudarstvu i energetika, zbornik radova, septembar 2006, Beograd, Univerzitet u Beogradu-Rudarsko-geološki fakultet (2006)
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Environmental Noise Impact Assessment for Large-Scale Surface Mining Operations in Serbia
Noise emissions are a significant environmental impact caused by the mining industry in all technological phases of surface mining, mineral processing, and waste disposal. This paper presents the role of noise impact assessment and control in large-scale surface mining operations. Mine planning develops the model of mining operations, ore excavation, and waste dumping scheduling and processing rates, including spatial distribution of mining activities. Such a level of mine planning requires an environmental impact assessment study. This can be achieved ...Uros Pantelic, Petar Lilic, Aleksandar Cvjetic, Nikola Lilic. "Environmental Noise Impact Assessment for Large-Scale Surface Mining Operations in Serbia" in Sustainability, MDPI AG (2023). https://doi.org/10.3390/su15031798
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Spatial assessment of the areas sensitive to degradation in the rural area of the municipality Čukarica
Nature and Landscape Conservation, Soil Science, Agronomy and Crop Science, Water Science and TechnologyNatalija Momirović, Ratko Kadović, Veljko Perović, Miloš Marjanović, Aleksandar Baumgertel. "Spatial assessment of the areas sensitive to degradation in the rural area of the municipality Čukarica" in International Soil and Water Conservation Research, Elsevier BV (2019). https://doi.org/10.1016/j.iswcr.2018.12.004
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Ostvarivanje dobiti pri uvođenju sistema agregatnih zamena na osnovnoj rudarskoj mehanizaciji površinskih kopova EPS
Jedan od osnovnih zadataka na površinskim kopovima uglja je ostvarivanje zadovoljavajućeg vremenskog i kapacitetnog iskorišćenja kontinualnih sistema. Da bi se to postiglo, neophodno je izvršiti izmene u postojećoj strategiji održavanja. Preduslov je uvođenje agregatne zamene vitalnih delova na rudarskim mašinama. Benefiti su višestruki. Očekivani rezultati ovakvog pristupa su: smanjenje zastoja i povećanje vremena rada; direktne materijalne uštede; bolja organizacija rada; racionalizaciju radioničkih i magacinskih kapaciteta; povećanje vrednosti mašina. Da bi se uvela agregatna zamena neophodne su investicije za nabavku ...Predrag Jovančić, Ignjatović Dragan, Đenadić Stevan. "Ostvarivanje dobiti pri uvođenju sistema agregatnih zamena na osnovnoj rudarskoj mehanizaciji površinskih kopova EPS" in X Međunarodna konferencija UGALJ, Zlatibor, Srbija, 13-16. Oktobar 2021., Jugoslovenski komitet za površinsku eksploataciju (2021)
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Definition of criteria and alternatives for choosing the optimal mining method deposits when applying multi: Criteria optimization, Belgrade, June 2024
Sanja Bajić, Dragoljub Bajić, Branko Gluščević, Radmila Gaćina, Josip Išek. "Definition of criteria and alternatives for choosing the optimal mining method deposits when applying multi: Criteria optimization, Belgrade, June 2024" in Podzemni radovi, Beograd, jun 2024, Centre for Evaluation in Education and Science (CEON/CEES) (2024). https://doi.org/10.5937/podrad2444071B
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Linear-motor plunger pump increases lifting efficiency
Bojan Martinović, Dušan Đekić, Dušan Danilović, Pavel Isaev. "Linear-motor plunger pump increases lifting efficiency" in Oil & Gas Journal (2022)
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Numerical Modeling and Simulation of the Effectiveness of Groundwater Source Protection Management Plans: Riverbank Filtration Case Study in Serbia
The paper describes the establishment and testing of an algorithm for developing sustainable management plans associated with groundwater source protection against potential pollutants and discusses the effectiveness of individual systems. The applied methodology pertains to groundwater resource management, particularly those cases that involve riverbank filtration. Namely, groundwater (numerical) modeling is employed to examine the groundwater regime and balance, as well as to create protection systems and illustrate their effectiveness. Particle tracking analysis is used to study pollutants’ travel and ...Dušan Polomčić, Dragoljub Bajić, Bojan Hajdin, Dragan Pamučar. "Numerical Modeling and Simulation of the Effectiveness of Groundwater Source Protection Management Plans: Riverbank Filtration Case Study in Serbia" in Water, MDPI AG (2022). https://doi.org/10.3390/w14131993
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Development of the Cost-Based Model for Monitoring the Lifetime of the Earth Moving Machines
This paper presents the model for the identification of reference points on the lifetime curve of engineering systems. This curve commonly represents the increase and decline of failure in relation to time. A direct correlation between failure rate and costs is assumed in this paper, therefore, statistical and empirical analysis of costs provided reference points. This approach is used for positioning stages of the engineering system’s lifetime with a minimal number of failures and costs, regardless of whether these ...Electrical and Electronic Engineering,Industrial and Manufacturing Engineering, Control and Optimization, Mechanical Engineering, Computer Science (miscellaneous), Control and Systems EngineeringUgljesa Bugarić, Milos Tanasijević, Stevan Djenadić, Dragan Ignjatović, Ivan Janković. "Development of the Cost-Based Model for Monitoring the Lifetime of the Earth Moving Machines" in Machines, MDPI AG (2022). https://doi.org/10.3390/machines10110995
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Structural and microstructural study of brookite based TiO2 nanocomposites with carbon black (C)
Structural and microstructural properties of TiO2-based nanocomposites with carbon black (C), synthesized by sol-gel-hydrothermal method, have been studied by XRPD and Raman scattering. Detailed size-strain analyses of XRPD and Raman scattering results are presented in order to investigate the influence of C content on brokite and anatase phase formation. The XRPD size-strain analyses have resulted in reliable structure and microstructure results for both anatase and brookite and their relative abundance ratio has been refined by Rietveld method. The brookite ...Aleksandar Kremenović, Mirjana Grujić-Brojčin, Nataša Tomić, Maja Šćepanović. "Structural and microstructural study of brookite based TiO2 nanocomposites with carbon black (C)" in The European Powder Diffraction Conference (EPDIC) Book of Abstracts, Šibenik, 31 May - 3 June 2022, EPDIC (2022)
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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)Technoeconomic, environmental and safety criteria generally affect the management of metallic and non-metallic mining operations. The first basic question that needs to be addressed when planning ore mining is which methods are adequate and what is the optimal mining technology? Due to the complex geologic framework of ore deposits, geological exploration has rendered synonymous the inherent uncertainties, vagueness, and inaccuracies. As a result, subjective evaluation by engineers and expert experience have become increasingly important. Given that the natural language ...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, Bulgarian Academy of Sciences (2023). https://doi.org/10.7546/CRABS.2023.09.12
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Transformer-Based Composite Language Models for Text Evaluation and Classification
Parallel natural language processing systems were previously successfully tested on the tasks of part-of-speech tagging and authorship attribution through mini-language modeling, for which they achieved significantly better results than independent methods in the cases of seven European languages. The aim of this paper is to present the advantages of using composite language models in the processing and evaluation of texts written in arbitrary highly inflective and morphology-rich natural language, particularly Serbian. A perplexity-based dataset, the main asset for the ...Mihailo Škorić, Miloš Utvić, Ranka Stanković. "Transformer-Based Composite Language Models for Text Evaluation and Classification" in Mathematics, MDPI AG (2023). https://doi.org/10.3390/math11224660
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A Data Driven Approach for Raw Material Terminology
Olivera Kitanović, Ranka Stanković, Aleksandra Tomašević, Mihailo Škorić, Ivan Babić, Ljiljana Kolonja (2021)The research presented in this paper aims at creating a bilingual (sr-en), easily searchable, hypertext, born-digital, corpus-based terminological database of raw material terminology for dictionary production. The approach is based on linking dictionaries related to the raw material domain, both digitally born and printed, into a lexicon structure, aligning terminology from different dictionaries as much as possible. This paper presents the main features of this approach, data used for compilation of the terminological database, the procedure by which it has ...sirovine, rudarstvo, terminologija, rečnik, terminološka aplikacija, mobilna aplikacija, digitizacija, leksički podaci, korpusi, otvoreni povezani podaci... followed by adding new Serbian terms to general lexica dictionaries, as well as adding bilingual terms. Dictionary development is relying on corpus analysis, details of which are also presented. Usage examples, collocations and concordances play an important role in raw material terminology, and have also ...
... followed by adding new Serbian terms to general lexica dictionaries, as well as adding bilingual terms. Dictionary development is relying on corpus analysis, details of which are also presented. Usage examples, collocations and concordances play an important role in raw material terminology, and have also ...
... technology offer the possibility of changing the face of lexicographical support in a mobile environment, from a pedagogical perspective [6]. Big data analysis methods have opened new possibilities for analyzing corpora, which contain large amounts of textual data. Thus, for example, Chen et al. [7] propose ...Olivera Kitanović, Ranka Stanković, Aleksandra Tomašević, Mihailo Škorić, Ivan Babić, Ljiljana Kolonja. "A Data Driven Approach for Raw Material Terminology" in Applied Sciences, MDPI AG (2021). https://doi.org/10.3390/app11072892
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Structural and geochronological constraints from the Drina-Ivanjica thrust sheet (Western Serbia): implications for the Cretaceous–Paleogene tectonics of the Internal Dinarides
Kristof Porkoláb, Szilvia Kövér, Zsolt Benkó, Gabor Héja, Melinda Fialowski, Balázs Soós, Nataša Gerzina Spajić, Nevenka Đerić, László Fodor (2019)Internal Dinarides, Drina-Ivanjica thrust sheet, Deformation history, K–Ar dating, Obduction, Structural analysis... out using a Rigaku Miniflex diffractometer with CuKxu radiation at 40 kV and 15 mA in the laboratory of the Institute for Geological and Geo- chemical Research of the Hungarian Academy of Sciences. Clay minerals were identified by XRD diagrams obtained from parallel-oriented specimens. Diagnostic ...
... should indicate the age of metamorphism. The formation of white micas may be a long-lasting process, which can be strongly influenced by the chemical composition of fluids present in the rock (Roberson and Lahann 1981). Moreover, isotopi- cally non-equilibrated detrital micas can be present ...
... Carpathian-Dinaridic realm. Keywords Internal Dinarides · Drina-Ivanjica thrust sheet · Deformation history · K-Ar dating · Obduction · Structural analysis Editorial handling: V. Cvetkovic. Institute for Nuclear Research of the Hungarian Academy of Kristof Porkolab Sciences, 18/c Bem tćr, Debrecen ...Kristof Porkoláb, Szilvia Kövér, Zsolt Benkó, Gabor Héja, Melinda Fialowski, Balázs Soós, Nataša Gerzina Spajić, Nevenka Đerić, László Fodor. "Structural and geochronological constraints from the Drina-Ivanjica thrust sheet (Western Serbia): implications for the Cretaceous–Paleogene tectonics of the Internal Dinarides" in Swiss Journal of Geosciences (2019)
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Determining the Availability of Continuous Systems at Open Pits Applying Fuzzy Logic
This work presents a model for determining the availability of continuous systems at open pits by applying fuzzy logic and fuzzy inference systems. The applied model was formed by the synthesis of independent partial indicators of availability. The model is based on an expert system for assessing the availability of continuous mining systems. The availability of the system, as a complex state parameter, is decomposed into the partial indicators, reliability, and convenience of maintenance, and the fuzzy compositions, used ...системи, континуални систем експоатације, површински коп, рударство, расположивост, фази логика, max–min композиција, min–max композицијаMiljan Gomilanović, Miloš Tanasijević, Saša Stepanović. "Determining the Availability of Continuous Systems at Open Pits Applying Fuzzy Logic" in Energies, MDPI AG (2022). https://doi.org/10.3390/en15186786
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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 ...... to 9.1 meters and feature reinforced male threads and a square section for gripping with wrenches during installation and removal [3.,8]. The chemical composition of the steel used for making sucker rods varies. Based on the steel composition, pumping rods are generally classified into tvo groups: ...
... Seal Head- zaptivna glava • „Automatic Dynamometer Recording System (optional) • Kezing-Tubing Connection, also known as Short Connection • Chemical Injection System (optional) 4.1 Horsehead Horseheads are mechanical installations installed on the surface that lift the rod strings and fluid ...
... paper presents the underground and surface equipment of the rod pump and describes the operation of the entire system. The second part involves an analysis and calculations using the "RODSTAR", "QRod" and "Prosper" software, which will define differences in calculations between software for Sucker ...Ana Ponoćko. Design of a sucker rod pumping system, 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 ...... regimes ofthe Resava River at the gauging stations ofthe Manasija Monastery (upper course) and the town of Svilajnac (lower course). The ydrological analysis encompasses a multiyear period of monitoring (1982—2020). The water budget and baseflow index are assessed for the catchment areas monitored by the ...
... balance equation parameters. Given that these two stations were characteristic of the highest and lowest eleva- tions of the Resava catchment, thc analysis consid- ered the arithmetic mean of the precipitation typi- cally recorded by thc stations, which amounted to 707.5 mm. A similar approach was ...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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Smanjenje sleganja plitkih temelja primenom mikrošipova
Slobodan Ćorić, Dragoslav Rakić (2021)Mikrošipovi su šipovi malog prečnika koji se grade tako što se u tlu specijalni postupkom formira bušotina koja se zatim armira i injektira. Njihov prečnik je najčešće 150 – 300 mm, a dužina može da bude i više desetina metara. Mikrošipovi mogu da se grade u svim vrstama tla i mogu da budu vertikalni i kosi. Oni se, stoga, koriste kao zamena za konvencionalne šipove i ankere. Primena mikrošipova u fundiranju predstavlja jedan savremeni način izgradnje i sanacije temelja/objekata. ...Slobodan Ćorić, Dragoslav Rakić. "Smanjenje sleganja plitkih temelja primenom mikrošipova" in Zbornik radova međunarodno naučno-stručnog savetovanja Zemljotresno inženjerstvo i geotehnički aspekti građevinarstva, Vrnjačka banja, 3-5. novembar 2021., Beograd : Savez građevinskih inženjera Srbije (2021)
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A new copper(II) arsenate, Na2Cu3(AsO3OH)4·4H2O containing discrete [Cu3O12]18− units: Synthesis, crystal structure and magnetic properties
Single crystals of the new disodium tricopper(II) tetrakis(hydrogenarsenate(V)) tetrahydrate, Na2Cu3(AsO3OH)4·4H2O were grown under hydrothermal conditions. The compound was characterized by room-temperature single-crystal X-ray diffraction, SEM-EDS analysis, Raman spectroscopy and magnetic susceptibility measurements. Na2Cu3(AsO3OH)4·4H2O represents a new layered structure-type [space group P21/c, a = 8.7089(17), b = 9.7452(19), c = 9.3353(19) Å, β = 92.63(3)°, V = 791.4(3) Å3, Z = 4]. The layers are normal to [100] and are composed of the isolated Cu3O12 units interconnected by AsO3OH coordination ...Na2Cu3(AsO3OH)4•4H2O, хидротермална синтеза, кристална структура, хидрирани хидрокси-арсенати, магнетна својстваTamara Đorđević, Ljiljana Karanović, Zvonko Jagličić. "A new copper(II) arsenate, Na2Cu3(AsO3OH)4·4H2O containing discrete [Cu3O12]18− units: Synthesis, crystal structure and magnetic properties" in Journal of Solid State Chemistry, Elsevier BV (2018). https://doi.org/10.1016/j.jssc.2018.05.024
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Security of Supply as a Major Part of the Energy Security Puzzle
Sigurnost snadbevanja prirodnim gasom Republike Srbije se kroz poslednje dve decenije tretira kao hitno, strateško, političko i bezbednosno pitanje. U sektoru prirodnog gasa, Republika Srbija je veoma zavisna od gasa koji uvozi iz Rusije. Indikatori sigurnosti snadbevanja predstavljaju jedan od osnovnih elemenata za određivanje energetske bezbednosti i snažne alate za usmeravanje energetskog sektora ka održivom razvoju. Metodolaška analiza prikazana u radu je bila koncentrisana na pokazatelje sigurnosti snadbevanja u oblasti energetske bezbednosti koji se odnose na sektor prirodnog gasa ...energetska bezbednost, sigurnost snabdevanja, energetski indikator, dostupnost energije, diversifikacija izvora i pravacaAleksandar Madžarević, Miroslav Crnogorac. "Security of Supply as a Major Part of the Energy Security Puzzle" in Energija, ekonomija, ekologija, University Library in Kragujevac (2022). https://doi.org/10.46793/EEE22-4.28M
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Development and evaluation of fracture gradient curve model: a case study of south-central Kazakhstan
An accurate fracture gradient value is one of the most important issues in oil and gas well design and drilling. The value of a fracture gradient is a critical parameter for determining the drilling mud weight and selecting the proper depths for setting the casing in the planning process of drilling operations. This paper proposed the new curve model of fracture gradient for the south-central Kazakhstan (central Asia) region based on the analysis of leak-off test and format integrity ...Branimir Stanisavljevic, Vesna Karovic Maricic, Irena Isakov. "Development and evaluation of fracture gradient curve model: a case study of south-central Kazakhstan" in International Journal of Oil, Gas and Coal Technology, Inderscience Publishers (2022). https://doi.org/10.1504/IJOGCT.2023.128042