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Упит dcterms_subject_txt:Nanofriction and wear

2341 items

  • Some models for determination of parameters of the soil oscillation law during blasting operations

    Suzana Lutovac, Dragan Medenica, Branko Gluščević, Rade Tokalić, Čedomir Beljić (2018)
    ... explosive amount, and conditions of blasting and geologic characteristics of the soil; all of this being determined on the basis of test blasting for the specific work environment. In the Sadovskii equation two parameters, K and n appear and they are conditioned both by rock mass characteristics and blasting ...
    ... blast site to the monitoring point (m); r0—radius of the explosive charge; and n—exponent, conditioned by soil properties and mining conditions and determined by field measurements as well. The radius of the explosive charge r0 and the amount of explosive Q are related by the equation: Q “ 4 3 ¨ π ¨ r3 ...
    ... reduced distances for models 1, 2 and 3. The survey of reduced distances R, recorded oscillation velocities vr, calculated oscillation velocities vi1, vi2, and vi3, as well as the difference between the recorded and calculated soil oscillation velocities for models 1, 2, and 3, are presented in Table 2. ...

  • Structural characterization of traditional pottery produced from local clay, Rujište (Ražanj, Central Serbia), in an effort to preserve its geoheritage

    Maja Milošević, Biljana Đorđević, Alena Zdravković (2021)
    ... a mixture. As some of the slabs have rolled and rough edges they may be regarded as illite and/or halloysite. Morphology varies from short tubular, spheroidal and elongated tubules, which are the most common. EDS data confirmed hydroxides of illite and iron. Illite minerals deposited from formation ...
    ... Management and Events Ltd., Sofia Printing House: Bulged, Sofia 1505 Editors: Ruslan I. Kostov, Radostina Atanassova ISBN 978-954-92875-6-1 © Earth and Man National Museum, 2021 © Bulgarian Mineralogical Society, 2021 9th International Conference Mineralogy and Museums ...
    ... clay body based on mineralogy and applying the obtained knowledge in the preservation of this type of intangible cultural heritage, inscribed in the National register of ICH and as geoheritage in Serbia as well. The analysis of the phase, mineral composition and structure of the clay body was ...

  • Rift sequence stratigraphy and its contribution to source rock understanding – Serbian part of Pannonian Basin

    Filip Anđelković, Dejan Radivojević (2018)
    ... simple shear exten- sional mechanism (Matenco and Radivojević, 2012). The analysis of syn-kinematic reflectors demonstrates that normal faulting migrates in time and space and took place on a wide Miocene time interval (roughly 20–5.5 Ma) (Matenco and Radivojević, 2012). The most prolific source rocks ...
    ... (Eds). The Carpathians and their foreland: geology and hydrocarbon resources, AAPG Memoir 84, 619–632. Matenco, L. Radivojević, D. 2012. On the formation and evolution of the Pannonian Basin: Constraints derived from the structure of the junction area between the Carpathians and Dinarides. Tectonics ...
    ... rocks in Serbian part of Pannonian Basin are marls and limestones of the Sarmatian and Pannonian (Kostić, 2012). Besides this sequence, source rocks are also to a lesser extent rep- resented by shales of the Badenian and Pre-Badenian Tertiary, while the Lower Pontian shales were found to contain only ...

  • Crystal structure of K3EuSi2O7

    Sabina Kovač, Predrag Dabić, Aleksandar Kremenović (2021)
    alkalni silikati elemenata retkih zemalja, kristalna struktura, sinteza metodom fluksa, rendgenska difrakcija na monokristalu
    ... space group P63/mcm and is isostructural with disilicates K3ErSi2O7 15 and K3YbSi2O7. 22 The crystal structure is comparable to the sorosilicate structure type reported earlier by Vidican and co-authors.13 The crystal structure of the title compound consists of Si2O7 groups and EuO6 polyhedra which ...
    ... code: Eu atoms and polyhedra are grey, Si atoms are dark grey and O atoms are white. Fig. 3. Projection of structure along [120] showing two types of regularly alternating layers, which are parallel to the (001) plane: (I) octahedral layers and (II) sorosilicate layers. K atoms and polyhedra are ...
    ... black, Eu atoms and polyhedra are grey, SiO4 polyhedra are dark grey and O atoms are white. OnLin e Fir st 6 KOVAČ et al. The structure is characterized by two crystallographically distinct six- coordinated sites occupied by Eu1 and Eu2: Eu1O6 is an octahedron (OC-6) and Eu2O6 is a trigonal ...

  • NMR kinetic studies of the interactions between [Ru(terpy)(bipy)(H2O)]2+ and some sulfur-donor ligands

    Aleksandar Mijatović, Biljana Šmit, Ana Rilak, Biljana Petrović, Dragan Čanović, Živadin D. Bugarčić (2012)
    Reakcije supstitucije monofunkcionalnog [Ru(terpi)(bipi)(H2O)]2+ kompleksa, gde je terpi = 2,2′:6′,2″-terpiridin i bipi = 2,2′-bipiridin, sa biološki relevantnim sumporo donorskim ligandima, kao što su tiourea, l-metionin, l-cistein i glutation, proučavane su u vodenim rastvorima tehnikom 1H i 13C NMR spektroskopije. Sve reakcije su proučavajne na pH 7,4, u prisustvu fosfatnog pufera, da bi se oponašalo fiziološko okruženje tokom procesa supstitucije. Reakcije se izvode na 295 K pod uslovima reakcija drugog reda. Uočeni rezultati pokazuju da brzina supstitucije snažno zavisi ...
    Materials Chemistry,Inorganic Chemistry,Physical and Theoretical Chemistry

  • The influence of alkyl polyglucosides (and highly ethoxylated alcohol boosters) on the phase behavior of a water/toluene/technical alkyl polyethoxylate microemulsion system

    Marija Ilic, Franz-Hubert Haegel, Vesna Pavelkic, Dragan Zlatanovic, Snezana Nikolic-Mandic, Aleksandar Lolic, Zoran Nedic (2016)
    The influence of additives (alkyl polyglucoside, Glucopon 600 CS UP and alcohol ethoxylate C18E100) on the behavior of the water/toluene/Lutensol ON 50 (technical oxoalcohol, i-C10E5) microemulsion system as a function of temperature and composition has been investigated. The phase behavior of the microemulsions was determined by vertical sections through the Gibbs phase prism (fish-like phase diagrams). Alkyl polyglucoside shifts the one phase region to lower temperatures compared with water/toluene/Lutensol ON 50 mixtures. This is contrary to the expectation, considering ...
    микроемулзија, толуен, алкил полиглукозид, оксоалкохол етоксилат, појачивач ефикасности, „fish“ дијаграми
    ... RESULTS AND DISCUSSION The pseudo-binary phase diagrams of micro- emulsion systems were determined at equal mass fractions of water and toluene (a= 0.5) for two non- ionic surfactants, pure linear CxjEs and technical branched i-Cxo5Es (Lutensol ON 50) in order to find the composition and temperature ...
    ... exists consisting of a middle-phase microemulsion in equilibrium with excess phases of oil and water, surrounded by two-phase regions illustrated as 20 and 20 . When a surfactant is mainly dissolved in water and two phases consist of a surfactant-rich water (lower) phase in equilibrium with an excess ...
    ... surfactant needed to solubilize water and oil and is a measure for the efficiency of the surfactant. The corresponding temperature, f, is a measure for the phase inversion temperature (//7). The phase diagrams were recorded by success- ively adding water and oil to the initial water-oil-surf- ...

  • Non-Detonating Chemical Mixture for Non-Invasive Methods of Rock Breaking

    Lazar Kričak, Milanka Negovanović, Nikola Simić, Stefan Milanović (2024)
    Within the Innovation developed several different non-detonating chemical mixtures for non-invasive methods of rock breaking. Laboratory and polygon tests gave the satisfactory results and knowledge enough to start the practical experiments in the field. The basis of this innovation is a theoretical assumption that certain chemical mixtures release a large quantity of gases during combustion. If these gases are found in the enclosed space a growing pressure on the walls of the chamber in which combustion takes place will ...
    non-detonating, chemical mixture, rock breaking, borehole pressure

  • Geologic Information System of Serbia

    Branislav Blagojević, Branislav Trivić, Ranka Stanković, Nenad Banjac, Olivera Kitanović (2011)
    Geologic information system of Serbia (GeolISS) represents repository for digital archiving, query, retrieving, analysis and geologic data visualization. The GeolISS is implemented through ESRI ArcGIS technology, and is designed to operate as a personal geodatabase (MS Jet 4.0 Engine) and SDE enterprise geodatabase in MS SQL Server. The objective of GeolISS implementation is integration of existing geologic archives, data from published maps at different scales, newly acquired field data, as well as Web publishing of geologic information. Physical implementation ...
    Geologic information system, Conceptual model, Logical model, Implementation, Geodatabase
    ... Mining and Geology, Đušina 7, 11000 Belgrade, Serbia, e-mail: btrivic@rgf.bg.ac.rs 3 Faculty of Mining and Geology, Đušina 7, 11000 Belgrade, Serbia, e-mail: ranka@rgf.bg.ac.rs 4 Faculty of Mining and Geology, Đušina 7, 11000 Belgrade, Serbia, e-mail: olja@rgf.bg.ac.rs 5 Faculty of Mining and Geology ...
    ... implement field data records and measurements i.e. the basis for classified features, interpretations and models. Any observed property can be expressed as a text, number, picture and geometry (location). Spatial entities are treated as observation localities and mapped/interpreted geologic entities ...
    ... references and persons involved and responsible for data acquisition. Metadata also include essential information’s about project, for which the data are to be collected. For data entry in GeolISS database designed special ArcGIS extension was designed and implemented in MS Visual Studio and ArcObject ...

  • Mine ventilation system planning using genetic algorithms

    Nikola Lilić, Ranka Stanković, Ivan Obradović (1997)
    The most common problem in contemporary mining practice related to the planning and analysis of ventilation systems is the optimization of partially regulated air distribution in mine ventilation networks. This paper presents a two step optimization procedure for partly regulated air distribution in mine ventilation networks. The first step is the determination of air distribution in all branches using the well known Hardy-Cross method. In the second step the distribution and parameters of air flow regulators with minimum engaged ...
    coal, lignite, and peat; ventilation systems; coal mining; underground mining; ventilation; mathematical models; design; air flow; optimization; calculation methods

  • Gate Road Support Deformation Forecasting Based on Multivariate Singular Spectrum Analysis and Fuzzy Time Series

    Luka Crnogorac, Rade Tokalić, Zoran Gligorić, Aleksandar Milutinović, Suzana Lutovac, Aleksandar Ganić (2021)
    Underground mining engineers and planners in our country are faced with extremely difficult working conditions and a continuous shortage of money. Production disruptions are frequent and can sometimes last more than a week. During this time, gate road support is additionally exposed to rock stress and the result is its progressive deformation and the loss of functionality of gate roads. In such an environment, it is necessary to develop a low-cost methodology to maintain a gate road support system. ...
    deformacije podgrade, lasersko skeniranje, višekanalna singularna spektralna analiza, prognoza, klasterisanje fuzzy vremenskih serija
    ... MAPEi, (30) MAPEi and AMAPE are represented in Table 10. Energies 2021, 14, 3710 15 of 20 Within the grouping step, we only have signal and noise components and we use two groups of indices, I; = {Avy,,Ay, } and Iz = {Av,,Ay, } and associate the group I; with signal component and the group I with noise ...
    ... function of time and the face advance. A procedure based on analytical functions has been developed to support the prediction of the tunnel performance and surface movements. Merlini and Falanesca [10] illustrated the comparison between the prognosis and the crosscheck of the support methods and the replacement ...
    ... Harris and Yuan [12], the basic SSA (singular spectrum analysis) algorithm was presented. Hassani and Zhigljavsky [13] showed that SSA is a powerful method for time-series analysis and forecasting. Hassani and Mahmoud- vand [14] pointed out that this method can be applied both to single series and jointly ...

  • Determining the Availability of Continuous Systems at Open Pits Applying Fuzzy Logic

    Miljan Gomilanović, Miloš Tanasijević, Saša Stepanović (2022)
    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 композиција

  • The interaction of organoselenium trans-palladium(II) complexes toward small-biomolecules and CT-DNA

    Vera M. Divac, Aleksandar Mijatović, Marina D. Kostić, Jovana Bogojeski (2017)
    Serija organoselenijum trans-paladijum(II) kompleksa 1 (bis(2-(fenilselanilmetil)oksolan)dihloropaladijum(II)), 2 (bis(2-(fenilselanilmetil)oksan)dihloropaladijum(II)) i 3 (bis(2) ,2-dimetil-3-(fenilselanil)oksan)dihloropaladijum(II)) su korišćeni za ispitivanje reaktivnosti ovog specifičnog tipa kompleksa prema različitim bio-molekulima. Ovaj sistem je od posebnog interesa jer se jako malo zna o supstitucionim reakcijam organoselenijum paladijum(II) kompleksa sa trans konfiguracijom. Zamena koordinovanog hlorida sa serijom malih bio-molekula (l-Met, l-His, l-Cis, GSH i 5′-GMP) proučavana je pod uslovima pseudo-prvog reda kao funkcija koncentracije nukleofila i temperature korišćenjem tehnika zaustavljenog toka. Rezultati za proučavane komplekse ukazuju da ...
    Pd(II), Selen, Substitucija, Kinetika, Mehanizam

  • The Fuzzy–AHP Synthesis Model for Energy Security Assessment of the Serbian Natural Gas Sector

    Aleksandar R. Madžarević, Dejan D. Ivezić, Miloš L. Tanasijević, Marija A. Živković (2020)
    Natural gas is used for the production of almost 20% of total energy today. The natural gas security of the Republic of Serbia is an urgent strategic, political and security issue. Serbia is one of the most vulnerable countries in Southeast Europe, because it only has one supply route. This study is a contribution to efforts to better understand the factors affecting energy security through the implementation of a new methodology based on the fuzzy–AHP synthesis model for measuring ...
    energetska bezbednost, prirodni gas, fazi AHP, AHP višekriterijumska analiza, fazi teorija
    ... Author Contributions: Conceptualization, A.R.M. and D.D.I.; methodology, M.L.T. and A.R.M.; supervision, M.A.Ž. and D.D.I.; validation, D.D.I. and M.A.Ž.; formal analysis and writing—original draft A.R.M.; investigation, A.R.M. and M.L.T. All authors have read and agreed to the published version of the manuscript ...
    ... operate with numerical and linguistic data and universality of application. The result of the proposed model shows a quantified assessment of energy security and its trend in the future of the natural gas sector. It indicates an unacceptably low level of present energy security and a gas system very vulnerable ...
    ... operate with numerical and linguistic data and universality of application. The result of the proposed model shows a quantified assessment of energy security and its trend in the future of the natural gas sector. It indicates an unacceptably low level of present energy security and a gas system very vulnerable ...

  • Softverski alati za korišćenje resursa za srpski jezik

    Ivan Obradović, Ranka Stanković (2008)
    ... dictionaries and aligned texts, can be further refined and used for different purposes, by means of tools specially developed for these tasks. The tools we describe are WS4LR, a software tool that has already been developed and used for solving different tasks within the Group, and a web application ...
    ... encompassed by WS4LR and WS4QE, namely the system of mor- phological dictionaries of Serbian, the Serbian wordnet and aligned texts. 2.1 Morphological dictionaries Morphological dictionaries of simple and compound words for Serbian have been devel- oped within the Group by C. Krstev and D. Vitas for many ...
    ... words (Vitas and Krstev, 2005). 3 WS4LR – a tool for maintenance and integrated use of lexical resources With the growth of the number of resources as well as their volume and content, a need emerged for the development of software tools which would alleviate their maintenance, use and inte- gration ...

  • From post-disaster landslides inventory to open landslides data

    Biljana Abolmasov, Miloš Marjanović, Uroš Đurić, Jelka Krušić (2021)

  • Post Early Miocenevertical-axis clockwise rotation in the West Vardar Zone of Serbia

    Vesna Lesić, Emo Marton, Vesna Cvetkov, Dragana Jovanović (2018)
    ... Faculty ofMining and Geology, Department ofGeophysics, Djusina 7, 11000 Belgrade, Serbia The Vardar-Tethyan mega-suture lies between the Eurasian and Gondwana margins. It is composed of remnants of obducted ophiolites and ophiolite mćlange, distal parts of adjacent continental margins and post-obduction ...
    ... sediments and Cenozoic igneous rocks. The area covered by this study belongs to the West Vardar and Jadar-Kopaonik units semsw Schmid et al. (2008). In this 160 km long strip we sampled on the north in the wider Rudnik Mts. area seven localities of Late Cretaceous micritic limestones and one locality ...
    ... carried out on locality (when applicable) and regionallevel. The obtained results show that the remanent magnetization both in the igneous rocks and sediments resides in magnetite. The locality mean directions for Late Cretaceous sediments are well defined and the remanenceis of post tilting: age. For ...

  • Simple 2D Gravity-density inversion for modeling of the sedimentary basin basement

    Ivana Vasiljević, Snežana Ignjatović, Dragana Đurić, (2019)

  • Building Terminological Resources in an e-Learning Environment

    Ranka Stanković, Ivan Obradović, Olivera Kitanović, Ljiljana Kolonja (2012)
    ... from RudOnto is used for labeling and annotation of cartographic content both in Serbian and English. Such annotation is enabled by the existing relations between Serbian and English translational equivalents, and by the strict relation between the dictionary and the content of the database. Some ...
    ... process, and it is included in the blended learning approach at the Faculty of Mining and Geology through an export of its subsets to the Moodle e-learning environment. This paper gives an outline of RudOnto, details about Moodle implementation on the Faculty of Mining and Geology, and describes ...
    ... broader and the narrower concept, respectively. Hence, a taxonomy in essence offers a hierarchical classification of concepts, in addition to the terms that describe them, and the definitions that explain them in more detail. Thesauruses offer and even more complex semantic structure, and due to ...

  • Analysis and visualization of geophysical well-logging data from closely spaced boreholes

    Branislav Sretković, Ivana Vasiljević, Dimitry Sidorov - Biryukov (2024)
    Geophysical logging measurements for determining the condition of the rock mass on the dam profile and locating the predisposed directions of water circulation and loss from the reservoir were conducted in four boreholes distributed at a close distance. The survey was carried out in a typical karst terrain, which is an additional challenge for defining the geological model, especially in terms of water retention. That kind of data set provides an excellent opportunity for a new approach to analysis ...
    well-logging in karst, water loss, data correlation, data fusion
    ... opportunity for a new approach to analysis and visualization that differs from the standard logging data processing. Numerical interpolation and correlation of data from various logging measurements (short-normal and long-normal resistivity, spontaneous potential and gamma ray logging), proved to be a ...
    ... s of karst in terms of surface and underground water circulation, as well as stability and hazard assessment for large objects such as dams (Sretković and Vučković, 2020). 'The use of geophysical characterization of karst systems can provide an economical and non-invasive alternative _ for ...
    ... for a new approach to analysis and visualization that differs from the standard logging data · processing. Numerical interpolation and correlation of data from various logging: measurements (short-normal and long-normal rresistivity, | spontaneous potential and gamma ray logging), proved to ...

  • Valorization of non-balanced coal reserves in Serbia for underground coal gasification

    David Petrović, Lazar Kričak, Milanka Negovanović, Stefan Milanović, Jovan Marković, Nikola Simić, Ljubisav Stamenić (2019)
    In the name of a better and safer energy future, it is our responsibility to focus our knowledge and activities to save on imported liquid and gas fossil fuels, as well as coal on which energy security of Serbia is based. The rationalization in the use of available energy resources certainly positively affects economy and the environment of a country. This paper indicates motivations for the application of the underground coal gasification process, as well as surface gasification for ...
    ugalj, gasifikacija, zaštita životne sredine, skladištenje, solarna
    ... activated, and the coke burns the surrounding coal and forms the reaction zone. Exothermic reactions (at f > 600 "C) are predominantly occurring in UCG process, and the resulting gas mixture can contain 8-20% CO», 5-20% CO, 10-20% H», and 2-5% CHoa. Ifthe gas mixture contains too much CO., and possibly ...
    ... from the gas mixture of UCG, and its possible storage carbon capture and storage, depends on the technological development of the separation and storage of CO [3]. Syngas can be used to produce a number of usable products, such as electricity, liquid fuels and chemical raw materials. The com ...
    ... bar and — capacity up to 4000 mš of gas/h. And for the gas parameters are: — quantity of produced gas up to 100000 mž of gas/h, — gas pressure 0.2 bar, and — gas temperature 200-400 *C. Air, Oxygen, Steam CO,CO, H„ CH, |- —— Oxidation zone. —— j- Reduction zone +| -- Drying and Pyrolysis ...