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Упит dcterms_subject_txt:Nanofriction and wear

2341 items

  • Data from the Digital Repository of the Faculty of Mining and Geology in eScience (eNauka)

    Biljana Rujević, Mihailo Škorić (2024)
    The paper describes linking the Digital Repository of the University of Belgrade, Faculty of Mining and Geology, with the eScience system in terms of transferring metadata about the results of researchers' scientific work. The steps taken to ensure a smooth harvesting of metadata are outlined. Additionally, a presentation of additional improvements to the OAI system is provided, aiming to contribute to the automatic linking of authors with their results in the eScience system.
    репозиторијуми, еНаука, метаподаци, Рударско-геолошки факултет

  • Analysis of the exhaust emissions inventory from auxiliary mining machines

    Stevan Đenadić, Aleksandar Mirković, Jovana Mitrović, Filip Miletić, Predrag Jovančić, Dragan Ignjatović (2023)
    Open-pit coal mines are equipped with a large number of mining machines and vehicles with diesel engines. Due to common daily operation of these machines and vehicles large amounts of exhaust gases which contain numerous pollutants are emitted into the atmosphere. The demand to reduce air pollution induced the activities in developed countries to map and calculate all gases emitted by industries to formulate and select adequate preventive activities. In collaboration with machine manufacturers, emission standards for off-road machines ...
    emissions, mining, auxiliary machines

  • Effectiveness Analysis of Different Bucket-wheel Excavators

    Stevan Đenadić, Predrag Jovančić, Dragan Ignjatović, Miloš Tanasijević, Filip Miletić (2021)
    Coal production in open-pit lignite mines in the Republic of Serbia is performed with continuous work systems. In addition to coal production, the same systems are used for the exploitation of large quantities of overburden. According to the reliability concept, continuous systems are in linear connection. If the failure occurs in one part of the system, that will produce a downtime of the entire system. The initial and most important factor of continuous systems is the bucket-wheel excavator. It ...
    bucket-wheel excavator, open-pit coal mine, mining, multi-criteria decision methods

  • The optimization of auxiliary machinery in open-cast lignite mines: a case study of bulldozers

    Dragan Ignjatović, Predrag Jovančić, Stevan Đenadić, Ivan Janković, Ivica Ristović (2019)
    One of the most important prerequisites for the successful operation of the open-cast lignite mine is to carry out all the auxiliary works timely with the necessary quality. The most important and most commonly used auxiliary machines are bulldozers. Engaging time of bulldozers use is in direct relation with the coefficients of the time and capacity utilization of the continuous system for the excavation of coal and tailings, which indicates their importance. More than 100 bulldozers have been hired ...
    open-cast coal mine, auxiliary works, bulldozers, optimization, availability
    ... selection, including savings and improvements, can be achieved by these activities: In-time replacement of auxiliary machines and vehicles; Usage of proven and quality machines with implemented unification as much as possible; Improvement of maintenance system; Implement modern and improved technologies ...
    ... reduce the operational and maintenance costs, increase the volume of auxiliary works and create conditions for maximal utilization of Excavator — Conveyor — Stacker and Excavator — Conveyor — Crusher systems. In another word, these activities will increase time utilization and production rate utilization ...
    ... Efficiency and Occupational Safety” (TR 33039), “Developed new methods for diagnosis and examination mechanical structures” (TR 35040) and a part of the project “Research on possibility for AT (Advanced Technology) rockbolting application in mines for the purpose of increasing work safety and production ...

  • Fluid inclusion systematics in the Okoška gora polymetallic deposit

    Aleš Šoster, Miloš Velojić, Barbara Potočnik Krajnc, Matej Dolenec (2021)
    ... conditions. In addition, the S2 and Q2 inclusions follow the growth zonesofthe crystals, indicating the simultaneouscrystal growth and fluid nclusion entrapement. Conversely, thc itregular, needle-like, and ameboid inclusions ofQ1 and S1 occur in linear, subparallel structures and have a higher proportion ...
    ... whereas the gangueis primarily quartz, sericite and adularia. The predominantminera! style is stockwork breccia with open-space veins and abundantdruse-lined cavities fill terminated crystals of gangue and ore minerals. Ore disseminations are minor and. restricted to pyrite. Ore minerals have not been ...
    ... resort (Mihael Ravnjak, verbal comm.). The timing and genetic conditi Okoška Gora deposit have bcen hotly debated (Droveniket al., 1980 and references t with metamorphosed and intrusion-related hydrothermal models proposed. Berce argued for a hydrothermalorigin ofthe deposit associated with emplacement of ...

  • 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 ...
    hydrogeological characteristics, water regime, water balance, karst aquifer, Resava catchment area
    ... Manasija Monastery and Qav = 4.35 m#/s at Svilajnac) and 2018 (Qav = 4.06 m?*/s at Manasija Monastery and Qav = 4.65 m?*/s at Svilajnac (Figs. 1a, 1b); • The ycar 1994 with a typical low discharge: Qav = 0.58 m*/s (at the Mansija Monastery) and 0.33 m?*/s (at Svilajnac) (Fig. 1c); and • The year 1999 ...
    ... 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 Svilajnac station (683 km?) and the Manasija Monastery station ...
    ... Kamen, and Vrtačelje (Avramović, 2005). Hydrogeological characteristics of the Resava catchment Based on the lithostratigraphic units and structur- al porosity, there are threc types of aquifers in the study arca. https://bgd.bg/review-bgs 1. Intergranular aquifers in the central and western ...

  • New approach to correlation of hydrocarbon reservoirs in sandstone layers of the "Mokrin" field"

    Saša Ivanišević, Dejan Radivojević (2018)
    геофизички каротаж, депозиционе средине, лежишта угљоводоника, миоцен, пост‐ рифтнo, секвенциона стратиграфија
    ... t, delta and  shore  plains  are  predominantly made  of  sandstones with  siltstone  and  clay  intercalations  and  local  occurrences of coal. Kikinda Formation sediments are deposited in shallow‐water environments and are  recognized by progradation and aggradation series (Figure 1a and 1b). Kik ...
    ... antitative  interpretation  of well‐log curves and the analysis of geological data from nine wells: KM‐117, 17, 1, 2, 3, 4, 5, 6 and 7  (Figure 1а and 1b). The principles of sequence stratigraphy have been applied in the analysis of geophy‐ sical  and  geological  data, while  the  correlation  of  ...
    ... the  integration of nine wells and one seismic profile.  The seismic profile is west‐east oriented, crossing the  “Kikinda‐Mokrin” high and  connecting  the above wells.   Reconstruction of depositional environments  and correlation of lithostratigraphic units (Figure 1a and 1b) have been executed base ...

  • Analysis of a simplified model for determining rock mass oscillation velocity at the Kovilovača open pit

    Suzana Lutovac, Miloš Gligorić, Jelena Majstorović, Luka Crnogorac (2023)
    ... of kilograms per a drillhol and blasting with dozens and even hundreds of tonnes of an explosive are being apllied in the world nowdays. Such large quantities of an explosive can cause seismic shocks with the intensity that can have hazardous impact on the environment and result in moving of buildings ...
    ... monitoring site r , reduced to the total quantity of the explosive Q i.e., R =%č. Parameters K and m are conditioned by } v characteristics of the rock mass and blasting conditions. Thus, V is a decreasing and convex function of the variable R. By applying the equation of rock mass oscillation while ...
    ... MASS OSCILLATION EQUATION In the Equation (1) tvo parameters appear, K and m, which need to be determined for a specific work environment and specific blasting: conditions. It is possible to determine the parameters K and n in many ways, 1.e., models, using the values obtained by experimental ...

  • The analysis of the geothermal energy capacity for power generation in Serbia

    Jana Stojković, Goran Marinković, Petar Papić, Mihailo Milivojević, Maja Todorović, Marina Ćuk (2013)
    Renewable Energy, Sustainability and the Environment
    ... TODOROVI] a, and Marina D. ]UK a a University of Belgrade, Faculty of Mining and Geology, Belgrade, Serbia b Geological Survey of Serbia, Belgrade, Serbia Original scientific paper DOI: 10.2298/TSCI120215033S An estimate of deep groundwater temperature is necessary for the research and uti- lization ...
    ... has to be estimated and consid- ered for power generation with the Kalina or the Rankine binary cycle. Best ther- mal waters (temperatures from 130 °C to 160 °C) for the purpose are located in the spa of Vranjska Banja, followed by Kuršumlijska, Sijarinska, and Jošani~ka spas and Bogati} of Ma~va. Pumped ...
    ... alter the water chemistry and greatly affect the use of gas, isotope or some other geothermometer [1]. Temperature of deep groundwater is determined indirectly, because the method in- volved is fast and inexpensive. Geothermometry is generally used in determining the current and previous temperatures ...

  • Medical Domain Document Classification via Extraction of Taxonomy Concepts from MeSH Ontology

    Mihailo Škorić, Mauro Dragoni (2019)
    This paper is a result of a task that was presented to attendants of Keyword Search in Big Linked Data summer school, that was organized by Vienna University of Technology, under the Keystone COST action in the summer of 2017. It presents a specific approach to the classification via creation of minimal document surrogates based on the US National medical library’s MeSH ontology, which is derived from the Medical Subject Headings thesaurus. In a series of previously classified medically ...
    document classification, MeSH, ontology, information extraction
    ... with string ", " and strings doc = doc.Replace(" and "); were pasted onto the beginning and the end of each row respectively (Figure 7).9 For replacement in all the documents to be classified, a second C# code has been prepared. It loads the classification documents one at a time and applies the script ...
    ... where you can get predefined queries, the ones for classes and predicates being aong them, or where other data can be obtained with the new SPARQL queries. The documentation, RDF triplets and the case example download are available online,4 and there is also an option for previewing the predicate via ...
    ... descriptions and XML labels, which is especially important if a local copy of the MeSH ontology is used5 Ontology consists of 56,309 medical concepts, described and systematically classified in a hierarchical tree (Figure 2). The concepts from the ontology are hierarchically collated, and each has an ...

  • Utilizing sewage wastewater heat in district heating systems in Serbia: effects on sustainability

    Marija Živković, Dejan Ivezić (2021)
    Transformation of the heating sector is recognized as being essential for ensuring reliable and afordable energy services provided with reduced consumption of energy sources and diminished impact on the environment and less import dependency. The possibility of utilizing energy sources that otherwise would be wasted needs to be considered and treated as a big advantage of district heating systems. Despite many advantages, sewage wastewater heat is still a mostly unused resource at the global level and a totally unused ...
    рекуперација топлоте из отпадних вода, систем даљинског грејања, топлотне пумпе, енергетске уштеде, емисија угљендиоксида, енергетска безбедност, Србија
    ... for ensuring reliable and affordable energy services provided with reduced consumption of energy sources and diminished impact on the environment and less import depend- ency. The possibility of utilizing energy sources that otherwise would be wasted needs to be considered and treated as a big advantage ...
    ... small vari- ation of flow rate and temperature over the year (Meggers and Leibundgut 2011). Due to the high heat capacity and density, wastewater is considered as a suitable heat source for implementation in heat pumps (HP) systems, whose operation is based on simple and proven technology (Hep- basli ...
    ... then heavy oil and at the end natural gas. Such an approach and order of substitution is governed by the need for maximiz- ing the reduction of GHG emission and air pollution in the cities. For the projection of the future state of district heat- ing systems, the heating area and efficiency of the ...

  • Cytotoxic activity of tetradentate Schiff Base Copper(II) complexes

    Nevenka Gligorijević, Aleksandar Mijatović, Sandra Aranđelović, Rada Baošić (2021)
    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 ...
    Bakar(II) kompleksi, citotoksičnost, ćelijski ciklus

  • Parameter determination of soil oscillation law using quotient of the relative growth increments of oscillation velocity and reduced distances at “Nepričava“ open pit mine

    Suzana Lutovac, Sanja Bajić, Marina Ravilić, Radmila Gaćina (2015)
    ... is transformed into a mechanical work. That energy, in the vicinity of blasting location, destructs and crushes rock mass, a bit further creates cracks and permanent deformations in the rock mass, and even further it is being transformed into elastic deformations. The effect of elastic seismic wave ...
    ... velocity v is given in the form of the function, is most frequently used: nv K R  where R is a reduced distance, and K and n parameters conditioned by soil characteristics and blasting conditions, thereby v is the decreasing convex function of the variable R. By the application of the law of ...
    ... of soil oscillation [cm/s], K - a coefficient conditioned by soil characteristics and blasting conditions determined by terrain surveying, n - the exponent, conditioned by soil properties and mining conditions and determined by field measurements as well, r - distance from the blast site to the ...

  • Coupling of artificial intelligence methods in the development of hybrid intelligent systems

    Ranka Stanković, Ivan Obradović, Nikola Lilić (2001)
    In this paper we present an approach which couples various artificial intelligence (AI) methods in the solution of complex problems that cannot adequately be solved by a single AI method. We argue that the resulting, hybrid intelligent systems (HIS) can be successfully implemented with the use of available AI software libraries. Different coupling methods are analyzed and a classification of hybrid systems based on the chosen method is given. Two case studies of hybrid systems used in mining engineering ...
    hibridni inteligentni sistemi, spregnuti sistemi, metode veštačke inteligencije, rudarske primene veštačke inteligencije
    ... Estimates estimation of gas and dust emission and temperature conditions flow process modelling using CFD Data acquisition ventilation and psychrometric parameters ventilation and psychrometric parameters Fig. 2 Structure of the hybrid system for mine ventilation planing and analysis INVENTS consists ...
    ... combines AI methods (GA and NN) coupled in PollutNet [3] with CFD modeling to attain a reliable estimation of air pollution distribution. The relations between GA, NN and CFD are largely influenced by the scale and quality of data as well as the required analysis and estimation results. The di ...
    ... combined GA and BP are used for NN training. This justifies the coupling of GA and NN for obtaining a more reliable prediction. Further extension of this system through an expert system which, on basis of the results obtained by the neural network, analyses and refines estimations and suggests activities ...

  • Analysis and Calculation of MMRS and Primary Gas Distribution Network in Urban Environment – Case Study Kučevo

    Aleksandar Madžarević, Pavle Janković (2022)
    Oblast primene prirodnog gasa je veoma široka. Kao energent može se koristiti za proizvodnju energije u elektranama, toplanama i postrojenjima za kombinovanu proizvodnju energije ili za zadovoljavanje različitih toplotnih potreba u industriji i širokoj potrošnji. Gas se može upotrebiti i kao sirovina u hemijskoj i petrohemijskoj industriji, a tokom poslednjih decenija nalazi primenu i u saobraćaju kao pogonsko gorivo u SUS motorima. Sa ekološkog stanovišta, prirodni gas predstavlja najprihvatljiviji izvor energije u poređenju sa drugim fosilnim gorivima. Pri sagorevanju ...
    distribucija gasa, projektovanje gasovoda, analiza potrošnje

  • Srbija u OneGeology Europe

    Danka Blagojević, Ranka Stanković, Petar Stejić, Velizar Nikolić (2014)
    Геолошки завод Србије као носилац Пројекта ОneGeologyEurope заједно са Рударско геолошким факултетом и Министарством за природне ресурсе, рударство и просторно планирање су се укључили у међународни Пројекат OneGeology Europe у мају 2013. године у већ поодмаклој фази израде Пројекта. До краја 2013. године испунили су завршене активности које треба да доведу до пуноправног укључења у Пројекат чиме је Република Србија нашла своје место на Геолошкој карти Европе 1:1М. Геолошка карта Србије 1:1М представља компилациону односно поједностављену верзију ОГК 1:500 ...
    OneGeologyEurope, метаподаци, хармонизација података, вишејезични мета-информациони систем
    ... Faculty of Mining and Geology and the Ministry of Natural Resources, Mining and Spatial Planning, have joined the international Project OneGeology Europe in May, 2013, while the project development had already been at an advanced stage. By the end of 2013, all the obligations envisaged and actions that ...
    ... difficult to discover, understand and use this data efficiently enough to answer critical questions and develop appropriate strategies. In INSPIRE (http://inspire.ec.europa.eu/), Geology designates a key dataset that is needed for the Groundwater and Soils Directives, GMES and GEOSS. The aim of the OneGeology ...
    ... lithology, age and genesis of rocks and tectonic structures. This document provides descriptions of geological vocabulary, concepts, definitions of concepts and their mutual relations. Its use is an obligation for all participants 1G-E. In Figure 7, is shown an example of a coding unit and its geological ...

  • Distribution of Uranium and Rare Elements in Radioactive Phosphate-Bearing Anomalies in Southeast Mongolia

    Boris Vakanjac, Neil Rutherford, Vesna Ristić Vakanjac, Tanita Đumić, Suzana Đorđević Milošević (2020)
    Soviet and Mongolian geologists initiated geological exploration of Mongolia for minerals after World War II (1945). These activities lasted until the breakup of the USSR in 1991. As part of this exploration systematic uranium and rare element exploration was undertaken across Mongolia. New exploration resumed in Mongolia at the beginning of the 21st century for a range of ore and mineral deposit styles including uranium, coal, base and precious metals and Fe-ore. This was generally undertaken by Western-based companies. This ...
    uran, radioaktivnost, kreda, retki elementi, fosfati, anomalije, Dornogobi

  • WS4LR - a Worksation for Lexical Resources

    Cvetana Krstev, Ranka Stanković, Duško Vitas, Ivan Obradović (2006)
    Lexical Resources, Wordnet, Serbian
    ... heterogeneous lexical resources, and the need for such a tool came from the large volume of resources the Group has developed in the course of many years and within different projects. The tool handles morphological dictionaries, wordnets, aligned texts and transducers equally and has already proved very useful ...
    ... section 3 we present the WS4LR modules and their functions, in section 4 some software consideration are given, and section 5 offers some conclusions and ideas for further work. 2. Overview of Resources Various lexical resources that can be produced and handled by WS4LR are briefly described ...
    ... character code. Morphological dictionaries of compound lemmas and word forms, named DELAC and DELACF, follow a similar format, except that both lemma and form can contain non-alphabetic characters – blank, hyphen, apostrophe, and alike. There is, however, one substantial difference. The inflection ...

  • Multi-Criteria Approach for Selecting Optimal Dozer Type in Open-Cast Coal Mining

    Ivan Janković, Stevan Đenadić , Dragan Ignjatović , Predrag Jovančić , Tomislav Šubaranović, Ivica Ristović (2019)
    Analitički hijererhijski proces (AHP), dozeri, eksploatacija uglja, površinski kopovi
    ... suitable dozers were Type 1, followed by Type 4, and then Types 2 and 3. The most economical dozer was Type 4, then Type 2, while Type 1 and 3 dozers were slightly more expensive. Type 1 and 2 dozers showed the best results given these specific conditions, and the same conclusion was confirmed by the expert ...
    ... method. Author Contributions: Conceptualization, I.R. and D.I.; methodology, T.S. and S.D.; validation, P.J.; formal analysis and writing—original draft preparation, I.J. Funding: This research and the APC was funded by the Ministry of Education and Science of the Republic of Serbia within the framework ...
    ... process of ore exploitation in open-cast coal mining is complex and demands hiring many people and providing varied equipment. In order to provide continuous (twenty-four hours a day) production and to excavate the planned amount of ore and overburden in an open-cast coal mine, it is necessary to achieve ...

  • Mineralogical Discrimination between Authentic and Recent Imitations of Pottery Manufacture in Zlakusa, Serbia

    Maja Milošević, Mihovil Logar, Biljana Đorđević (2021)
    ... electric drive) marked as -4- and by moulding (application of a mould) marked as -5-. Close examination of surface features and morphology was conducted to determine the characteristic attributes for a specific technique. Phase and mineral composition, texture, and structure of the samples ...
    ... it a unique phenomenon, in technological terms, is the fact that with the discovery of new techniques and production processes, the old ways, already adopted and mastered continued to live and actively coexist until today. This also brings a rise in imitations of pottery manufacture. ...
    ... surface colour, the appearance of bumps and bulges, horizontal lines or their absence, smooth surface and the presence of irregularities are the main indicators for assessing differences in the production of vessels. The maximum temperature, heating mode and oxidation atmosphere in the ovens were ...