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Упит dcterms_subject_txt:Nanofriction and wear

2341 items

  • A Fuzzy Expert Model for Availability Evaluation

    Dejan Ivezić, Miloš Tanasijević, Predrag Jovančić, Radiša Đurić (2019)
    Each technical system within itself carries the great potential danger of possible occurrence of failure and damages. Mining machines are characteristic by great investment values, costs of unplanned shutdowns, complex working conditions, and environment and workers hazards. Systematic monitoring of the mining machinery is of great importance for the management of the mining companies. Availability is the overall concept of quality of service. Includes information regard to operating state, an idle state, a standby state and shut down. The ...
    raspoloživost, ekspertski sistem, fazi teorija, buldozeri
    ... variables related to A itself and to R, M and S. It is necessary to describe five linguistic variables i.e. fuzzy sets: poor, adequate, average, good and excellent. Fuzzy sets are in triangular form, and they are presented in relation to membership function (μ) and measurement units of A indicators ...
    ... in terms of R, with grades "good" in extent of 40% and “average” in extent of 60%; M as "average" in extent of 100% and S as "adequate" in extent of 100%; machine Dressta as "average" in all terms and Caterpillar as "good" in terms of R and S and "excellent" in term of M. This can be written in the ...
    ... breakdowns and delays. The availability is commonly used as a measure of dependability. Availability is expressed by quantitative indicators, and these indicators are measures of dependability and quality of service. Availability performance has a decisive influence on the dependability and the quality ...

  • Production of electricity from coal-fired power plants and accompanying CO2 emissions: comparison of EU-27 and US

    Uroš Djorgovski, Aleksandar Madžarević, Predrag Jovančić (2023)
    Even in the third decade of the 21st century, large power plants are still responsible for more than half of the electricity production in Europe and US. They predominantly use fossil fuels in their work, which results in the emission of pollutants into the air, soil and water. In addition to the production of electric energy, fossil fuels, including coal, are used for industrial purposes. Although the use of coal, especially in the countries of the European Union, is ...
    CO2, емисија, угаљ, термоелектрана, САД, ЕУ-27
    ... regions and sectors. CO> emissions increased in North America and Asia (excluding the People's Republic of China), to a greater extent than emissions reductions in Europe and China. At the global level, CO>» emissions from electricity generation and the transport sector increased by 261 Mt and 254 ...
    ... air, soil, and water. Sector of production and use of coal also provides Jobs to around 230.000 people in mines and power plants across 31 regions and 11 EU countries [8]. Table 1. The US coal consumption in 2021 [6] Electric power | Industrial total | Commercial | Residential and transportation' ...
    ... led by increased Asian market and economic development. Global demand for electricity increased by 2.7% [4]. This paper analyzes production and emissions of CO in sector of electricity in two big worlds region - EU-27 and US. The emission of CO> in EU-27 and US in last 30 years are anatomized ...

  • Control of substructure construction of railways in the Republic of Serbia

    Dragan Lukić, Dragoslav Rakić, Irena Basarić Ikodinović (2022)
    Контрола збијености природног тла (у ископу) или збијеног у насипу при изградњи саобраћајница представља један од основних облика контроле квалитета доњег строја. Код изградње брзих саобраћајница (аутопутеви и брза железница) приоритет је постизање високог нивоа контроле извршених радова. У циљу онемогућавања диференцијалног слегања (при изградњи насипа), или промене запремине услед допунског збијања материјала, које неминовно доводе до деформација, потребно је извршити оптимално збијање материјала. У оквиру овог рада приказује се техничка регулатива која регулише контролу збијености при изградњи железничке ...
    доњи строј, техничка регулатива, насип, збијеност, контрола
    ... open track tracks and main tracks on main railways Ev2 > 80 MN/m2, Ev2/ 5 MN/m2, Rc* for the construction and improvement of open railway tracks and main tracks on regional railways Ev2 > 60 MN/m2, Ev2/Ev1 m2, Rc* for the construction and improvement of tracks on local railways and secondary tracks ...
    ... the standard and technical conditions (harmonized with the standard) determine in examination process the zone where soil homogeneity is ensured (by granulometric composition and moisture) and in statistically reliable research conditions. Perform the necessary tests and correlations and, based on them ...
    ... of the protective layer is 20 cm, and in the case of thickness > 30 cm it is installed and compacted in two layers. Load-bearing capacity at the level of the railway planum meets the following requirements: for the construction and improvement of open track tracks and main tracks on main railways Ev2 ...

  • 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

  • Improvement of education through the cooperation between CEEPUS EURO Geo-Sci network and scientific projects: examples from UB-FMG

    Kristina Šarić, Dejan Prelević, Miloš Marjanović, Uroš Stojadinović, Vladimir Simić (2024)
    CIII-RS-0038, Recon Tethys, DEMONITOR, TMCmod, REASONING

  • 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

  • Towards a Mining Equipment Ontology

    Ranka Stanković, Ivan Obradović, Olivera Kitanović, Ljiljana Kolonja (2012)
    ... management and maintenance. Basically, IT is introduced through computer-aided information systems, with the aim of securing reliable information for management and decision making in mining engineering systems [2]. Various IT maintenance support systems and tools have been developed and implemented ...
    ... entities and their values • Functions and processes entities are involved in • Constraints and rules pertaining to entities Based on these elements an ontology offers a formal representation of knowledge, through a vocabulary containing a set of concepts, semantic relationships between them and simple ...
    ... range of the data, number of decimals, and its rank for presentation in the analysis. Figure 5: Panel for defining constructive and technological equipment parameters Figure 5 depicts a panel used for overview and entry of data in technological systems and equipment assigned to them. The left ...

  • A comparative study of the molecular and isotopic composition of biomarkers in immature oil shale (Aleksinac deposit, Serbia) and its liquid pyrolysis products (open and closed systems)

    Gordana Gajica, Aleksandra Šajnović, Ksenija Stojanović, Jan Schwarzbauer, Aleksandar Kostić, Branimir Jovančićević (2021)
    The molecular and isotopic composition of biomarkers in initial bitumen isolated from immature (0.41% Rr) oil shale samples (Aleksinac deposit) and liquid products obtained by pyrolysis in open (OS) and closed (CS) systems are studied. The influence of pyrolysis type and variations of kerogen type on biomarkers composition and their isotopic signatures in liquid products is determined. The applicability of pyrolysis type, numerous biomarkers and carbon isotopic compositions (δ13C) of n-alkanes in liquid pyrolysates is established. Pyrolysis experiments were ...
    Uljni šejl, Aleksinac, organska supstanca, otvoreni i zatvoreni sistem pirolize, biomarkeri, izotopski sastav ugljjenika

  • Preliminary regional landslide susceptibility assessment using limited data

    Igor Peshevski, Milorad Jovanovski, Biljana Abolmasov, Jovan Papic, Uroš Đurić, Miloš Marjanović, Ubydul Haque, Natasha Nedelkovska (2019)
    In this paper a heuristic approach for preliminary regional landslide susceptibility assessment using limited amount of data is presented. It is called arbitrary polynomial method and takes into account 5 landslide conditioning parameters: lithology, slope inclination, average annual rainfall, land use and maximum expected seismic intensity. According to the method, in the first stage, a gradation is performed for each of the carefully selected conditioning parameters by assigning so called rating points to the grid cells on which the ...
    klizišta, podložnost
    ... landslides were defined as translational and rotational debris and earth slides and rock falls. Over 60% of the occurrences have been defined as intermediate and deep, and those mostly occurred in debris material overlying hard rock masses or in fluvioglacial and proluvial sediments. The depth of some ...
    ... depending on the analyzed region and conditioning parameters used, the proportions and values of the ratings and sensitivity co- efficients need to be carefully selected. This selection should be done by an expert team and then checked by running several combinations of ratings and sensitivity coefficients ...
    ... type (14.08% and 16.6%, for WLT-TLSR-100 and WLT- TLSR-500 variants, respectively), followed by slope inclination (12.97% and 14.69%, for WSI-TLSR-100 and WSI-TLSR-500 var- iants, respectively). The smallest changes in landslide distribution are noted for land use (6.83% for WLU-TLSR-100 and 2.39% WL ...

  • Application of VIКOR method in the selection of an optimal splution of excavation “Borska Reka” ore deposit

    Sanja Bajić, Dragoljub Bajić, Branko Glušćević, Radmila Gaćina (2023)

  • Lower Berriasian ammonites from Dedina (Golubac Mountains, eastern Serbia) and their biostratigraphic implication

    Zdenek Vasícek , Dragoman Rabrenović, Petr Skupien, Barbara Radulović (2023)
    Ammonites, Taxonomy, Lower Berriasian, Getic, Northern Tethys, Serbia
    ... ropalaeontological, magnetostratigraphic and · geochemical methods. The Dedina section yields rich and diverse associations of macrofauna represented by cephalopods (ammonites, aptychi and belemnites), brachiopods, and bivalves. Among the most frequent and diverse are ammonites. The current study ...
    ... Besnosov and Mikhailova (1991), Wright et al. (1996), Kvantaliani et al. (1999), Klein (2005), Arkadiev and Bogdanova (2004, 2005), Bogdanova and Arkadiev (2005), Arkadiev and Bogdanova (2012), Arkadiev (2014), Bulot et al. (2014), Frau et al. (2016a,b), Hoedemaeker et al. (2016), and Szives ...
    ... tional deposits between the Tithonian and Berriasian and, according to Arkadiev and Bogdanova (2012), from the lower Ber- riasian (Jacobi Zone) of Crimea, Bulgaria, Romania, Austria, France, and Spain. Occurrence. Light grey marlstones of layers 80 and 96. Pseudosubplanites subrichteri (Retowski ...

  • Joint interpretation of paleomagnetic, structural and AMS results from the Vardar Zone of Serbia

    Emo Marton, Marinko Toljić, Vesna Lesić, Vesna Cvetkov (2021)

  • Evaluation of the effects of wastewater heat pump integration into district heating systems by simulation

    Dejan Ivezić, Marija Živković, Dimitrije Manić, Aleksandar Madžarević, Boban Pavlović, Dušan Danilović (2023)
    The integration of wastewater heat pumps (using purified water) in district heating systems is analyzed in this paper. The simulation procedure is proposed to analyze the impacts of stochasticity of purified water temperature and flow to heat pump integration and operation. The analysis includes calculation of the daily and seasonal coefficient of performance, as well as fossil fuel savings and CO2 emission reduction due to wastewater heat pump use. The proposed procedure is implemented for the case study in ...
    otpadne vode, toplotna pumpa, daljinsko grejanje, simulacija

  • Application of a Method for Intelligent Multi-Criteria Analysis of the Environmental Impact of Tailing Ponds in Northern Kosovo and Metohija

    Gordana Milentijević, Blagoje Nedeljković, Milena Lekić, Zoran Nikić, Ivica Ristović, Jelena Đokić (2016)
    flotacijska jalovišta, životna sredina, višekriterijumska analiza, ekologija, Trepča
    ... cultural, social and organizational frameworks; it should be applicable to large and small companies and for large and small-scale environmental pollutants. It was thus decided that the ranking of five current tailing ponds should be done by multi-criteria analysis. Field work and analysis of flotation ...
    ... 43007: Climate Change Impact to the Environment-Assessment, Adaptation and Mitigation, Sub-Project 15: Climate Change Impact to the Environment and Natural Resources of the North of Kosovo and Metohija and Project OI 176018: Geological and ecotoxicological investigations in identification of geopathogenic ...
    ... estimated that there are around 700 million tons of flotation and separation tailings, between 1.4 and 1.7 billion tons of tailing wastes from opening pits and around 170 million tons of ashes from thermal power plants on deposit spots and landfills in Serbia. Metallurgy in the Republic of Serbia contributes ...

  • A comparison between ARIMA, LSTM, ARIMA-LSTM and SSA for cross-border rail freight traffic forecasting: the case of Alpine-Western Balkan Rail Freight Corridor

    Miloš Milenković, Miloš Gligorić, Nebojša Bojović, Zoran Gligorić (2023)
    železnica, prekogranični teretni saobraćaj, ARIMA, LSTM, SSA

  • Razvoj ARCGIS geobaze površinskog kopa korišćenjem UML CASE alata

    Aleksandra Tomašević, Ljiljana Kolonja, Ivan Obradović, Ranka Stanković, Olivera Kitanović (2012)
    ... properties and relations with other objects. GIS allows users to create queries, analyze spatial information, manage data and maps, and present results of all these operations. GIS enable the user to create regional and detailed maps of both active and prospective open pits, model the geology and the terrain ...
    ... geometry (data defining the shape and size of an entity and its position in space) and topology (data defining relations between different geographic entities). Consequently, there are three basic groups of data in a GIS, namely: vector data, attribute data and raster data. Geodatabase development ...
    ... development reduces data redundancy and enables better documenting and maintenance of the entire system. The general strategy for using UML CASE tools for design and development of geodatabases entails the use of UML for defining the database schema, creation of classes, and only after that, filling with ...

  • Trace elements and garnet formation in a distal skarn zone: a case study of the Rudnik deposit, Central Serbia

    Bojan Kostić, Pavle Tančić, Natalija Batoćanin (2024)
    geohemija granata, retke zemlje, fluidne inkluzije, skarnovsko ležište Rudnik

  • State and perspective of individual household heating in Serbia: A survey-based study

    Boban Pavlović, Dejan Ivezić, Marija Živković (2021)
    This paper presents the results of the household survey on individual household heating systems in Serbia. The survey was conducted in the period October to December 2020 with the participation of 1100 households with individual household heating systems. The information collected in the questionnaire can be separated into three main parts: basic household data, current heating system characteristics, and households’ perceptions and attitudes. The survey results provide unique and comprehensive information concerning individual household heating systems and the main ...
    Domaćinstva, Individualni sistemi grejanja, Korišćenje energije, Stavovi potrošača, Anketa, Srbija

  • Influence of mono- and two-component organic modifiers on determination of lipophilicity of tetradentate Schiff bases

    Nikola Stevanović, Aleksandar Mijatović, Aleksandar Lolić, Mario Zlatović, Rada Baošić (2021)
    Ispitivani su uticaji primene mono- i dvokomponentnih organskih modifikatora na određivanje lipofilnosti 12 tetradentatnih Šifovih baza metodom reverzno-fazne tankoslojne hromatografije. Osnovni cilj je da se proceni tip interakcije između posmatranih jedinjenja i komponenti primenjenih hromatografskih sistema i uspostavi neki obrazac ponašanja kako bi se lakše izabrala kombinacija organskih modifikatora koji će simulirati interakciju u biološkim sistemima na osnovu činjenica da iste osnovne intermolekularne interakcije su odgovorne za ponašanje supstanci i u biološkom i u hromatografskom sistemu. Primenjeni organski modifikator ...
    Šifove baze, Lipofilnost, RP-TLC, Organski modifikatori

  • Coal homogenization stockyard sizing “Tamnava – Zapad” case study

    Božo Kolonja, Dinko Knežević, Ranka Stanković, Dejan Stevanović, Detlef Trummer (2016)
    ... can be used to calculate, plan, control and predict the quality of ore being stacked and/or reclaimed with a great degree of accuracy. Robinson (2004) presents mathematical and computer models for the geometry of a stockpile, using both actual grade data and a variogram to describe the input variation ...
    ... chevron and window methods. Given than the windrow method is technologically more complex and requires the use of more complicated and more expensive machines, the chevron method is generally more desirable. There is no general rule defining which number of layer is considered small and which ...
    ... causes problems in organizing operations at the stockyard and arranging coal stacking and reclaiming. Namely, the rule is that piles are alternately filled and emptied, so that when the pile is being filled it is filled completely, and emptied completely when being emptied. In the example of coal ...