Претрага
395 items
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Development of the Availability Concept by Using Fuzzy Theory with AHP Correction, a Case Study: Bulldozers in the Open-Pit Lignite Mine
Stevan Đenadić, Dragan Ignjatović, Miloš Tanasijević, Uglješa Bugarić, Ivan Janković, Tomislav Šubaranović (2019)Availability is one of the most used terms in maintainability engineering. This concept is used to denote: The quality of service of an engineering system, i.e., machines, weak points’ analysis, asset management, as well as making decisions in the process of life cycle management. Availability is an overall indicator and contains partial indicators that are oriented towards reliability, maintenance, and logistical support. Availability presents a variable value and changes in time and space. Usually, availability is shown as the ...... Publications: Pittsburgh, PA, USA, 2000. 29. Djenadic, S.; Jovancic, P.; Ignjatovic, D.; Miletic, F.; Jankovic, I. Analiza primene višekriterijumskih metoda u optimizaciji izbora hidrauličnih bagera na površinskim kopovima. Tehnika 2019, 70, 369–377. [CrossRef] 30. Ignjatovic, D.; Jovancic, P. Optimisation ...
... preventive and service maintenance, for reasons of constructive nature, inaccessibility of parts, due to the appearance of corrosion, the mass of the element, and the like. • ‘D’(M)—It is not possible to plan the duration of the intervention and the organization of work. There are a number of complications ...
... comparison of the elements is the numerical value that presents the priority vector (W). According to Equation (16), the priority vectors of each element are calculated, after which the possibility of forming the mathematical matrix M (17) is created, whose calculation provides the solution according ...Stevan Đenadić, Dragan Ignjatović, Miloš Tanasijević, Uglješa Bugarić, Ivan Janković, Tomislav Šubaranović. "Development of the Availability Concept by Using Fuzzy Theory with AHP Correction, a Case Study: Bulldozers in the Open-Pit Lignite Mine" in Energies, MDPI AG (2019). https://doi.org/10.3390/en12214044
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Demise of the Wetterstein Carbonate Platform and onset of the Dachstein Carbonate Platform recorded in deep-water successions of the East Bosnian-Durmitor megaunit (Pliješevina, northern Montenegro, Dinarides)
Milica Mrdak, Eva Wagerer, Milan Sudar, Nevenka Djerić, Martin Đaković, Hans-Jürgen Gawlick. "Demise of the Wetterstein Carbonate Platform and onset of the Dachstein Carbonate Platform recorded in deep-water successions of the East Bosnian-Durmitor megaunit (Pliješevina, northern Montenegro, Dinarides)" in Geologica Carpathica, Central Library of the Slovak Academy of Sciences (2024). https://doi.org/10.31577/GeolCarp.2023.26
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Novi model za postizanje optimalne proizvodnje na naftnom polju Amal
Elnori Elmabrouk Ali Elhaddad (2015-04-16)Doktorskom disertacijom analizirani su i proučavani problemi proizvodnje nafte iprimenjene metode za njihovo rešavanje na naftnom polju Amal. Ukratko jeprikazana proizvodnje nafte u Libiji, njene karakteristike i rezerve, da bi se videoznačaj ovog naftnog polja.Utvrđeno je da su na naftnom polju Amal ključni problemi koji prate procesproizvodnje taloženje parafina, pojava slojnog peska, neefikasan rad gasliftsistema, neefikasna desalinizacija nafte i ekološki problemi. Proizvodniproblemi, pojedinačno i više njih zajedno, na nekim bušotinama uzrokovali susmanjenje proizvodnje nafte od 40 do 75%. Zbog ...... drugih hemijskih elemenata. Slika 5.5. Tipovi kristala parafina 34 Rešavanje problema taloženja parafina razmatrano je u zavisnosti od mesta taloženja u proizvodnom sistemu (slika 5.6). Za taloženje parafina u perforacijama predlaže se primena samo hemijskih metoda. Preporučuje se ...
... Bušotina Naftovod Hemijske metode Hemijskemetode Termičke metode Hemijskemetode Termičke metode 35 Sood i Lal, 2008; Rainer i dr, 2013).Doziranjem aditiva u bušotinu preventivno se rešava problem taloženja parafina (Elnori Elhaddad i dr, 2014). Primena hemijske metode je na ovom naftnom polju ...
... proizvodnih problema i do sada primenjenih metoda za njihovo rešavanje. Intenzitet proizvodnih problema je takav da zahteva primenu novih metoda i aktivnosti za njihovo rešavanje. Zbog toga se u doktorskoj disertaciji predlaže uvođenje novih metoda i aktivnosti koje je potrebno primeniti za ...Elnori Elmabrouk Ali Elhaddad. "Novi model za postizanje optimalne proizvodnje na naftnom polju Amal" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2015-04-16)
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Novi model za postizanje optimalne proizvodnje na naftnom polju Amal
Elnori Elmabrouk Ali Elhaddad (2015-04-16)Doktorskom disertacijom analizirani su i proučavani problemi proizvodnje nafte iprimenjene metode za njihovo rešavanje na naftnom polju Amal. Ukratko jeprikazana proizvodnje nafte u Libiji, njene karakteristike i rezerve, da bi se videoznačaj ovog naftnog polja.Utvrđeno je da su na naftnom polju Amal ključni problemi koji prate procesproizvodnje taloženje parafina, pojava slojnog peska, neefikasan rad gasliftsistema, neefikasna desalinizacija nafte i ekološki problemi. Proizvodniproblemi, pojedinačno i više njih zajedno, na nekim bušotinama uzrokovali susmanjenje proizvodnje nafte od 40 do 75%. Zbog ...... drugih hemijskih elemenata. Slika 5.5. Tipovi kristala parafina 34 Rešavanje problema taloženja parafina razmatrano je u zavisnosti od mesta taloženja u proizvodnom sistemu (slika 5.6). Za taloženje parafina u perforacijama predlaže se primena samo hemijskih metoda. Preporučuje se ...
... Bušotina Naftovod Hemijske metode Hemijskemetode Termičke metode Hemijskemetode Termičke metode 35 Sood i Lal, 2008; Rainer i dr, 2013).Doziranjem aditiva u bušotinu preventivno se rešava problem taloženja parafina (Elnori Elhaddad i dr, 2014). Primena hemijske metode je na ovom naftnom polju ...
... proizvodnih problema i do sada primenjenih metoda za njihovo rešavanje. Intenzitet proizvodnih problema je takav da zahteva primenu novih metoda i aktivnosti za njihovo rešavanje. Zbog toga se u doktorskoj disertaciji predlaže uvođenje novih metoda i aktivnosti koje je potrebno primeniti za ...Elnori Elmabrouk Ali Elhaddad. "Novi model za postizanje optimalne proizvodnje na naftnom polju Amal" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2015-04-16)
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Aлтерације перидотита контролисане карактером флуида на примеру харцбургита Рудника - Серпентинизација или талкизација?
Стефан Петровић, Наталија Батоћанин (2020)У раду су приказани резултати испитивања серпентинисаних харцбургита Брђана (43°58'45.1" СГШ, 20°25'12.6" ИГД) и талкизираних харцбургита откривених у интервалу 429-559.8 m у истражној бушотини 330А/18 (44°07'33.2" СГШ, 20°30'28.5" ИГД) на Руднику. Узорци оба локалитета показују карактеристике резидуалних харцбургита из омотача, односно тектонита; лепидобластичне, бластозрнасте, или порфирокластичне структуре и масивне текстуре. Серпентинисани харцбургити и серпентинити Брђана су изграђени од серпентина, ретких реликата оливина и ортопироксена, акцесорног спинела, и веома ретког секундарног магнезита и магнетита. Најдоминантнији састојак (местимично гради и преко ...... перидотита. Након разматрања потребних услова за процесе талкизације, односно серпентинизације изведени су прелиминарни закључци. 18 МАТЕРИЈАЛ И МЕТОДЕ За потребе овог рада примењена су теренска и лабораторијска испитивања. У току теренских испитивања узета су четири репрезентативна узорка ...
... Универзитета у Београду. РЕЗУЛТАТИ Харцбургити Рудника су стене тамносиве, скоро црне боје, масивне текстуре. Структура је бластозрнаста са елементима лепидобластичне и порфирокластичне. Најзаступљенији минерали су оливин и секундарни талк. Подређено је присуство моноклиничног пироксена, секундарног ...Стефан Петровић, Наталија Батоћанин. "Aлтерације перидотита контролисане карактером флуида на примеру харцбургита Рудника - Серпентинизација или талкизација?" in Записници српског геолошког друштва, Српско геолошко друштво, Београд (2020)
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Environmental Energy Security Indicators as Tools for Environmental Protection
Еколошка прихватљивост је постала незаменљив синтезни показатељ сваке валидне енергетске анализе у последње две-три деценије. Енергетска безбедност је у директној хармонији с еколошком прихватљивошћу кроз многе прописане политичке циљеве, економске користи, правне тековине итд. Индикатори еколошке сигурности представљају један од основних елемената за одређивање енергетске безбедности и снажне алате за усмеравање енергетског сектора ка одрживом развоју. У овом раду, анализа је била концентрисана на показатеље енергетске безбедности у области животне средине који се односе на сектор природног гаса у ...енергетска безбедност, еколошки енергетски индикатори, заштита животне средине, еколошка прихватљивостAleksandar Madžarević, Dejan Ivezić, Marija Živković , Miloš Tansijević. "Environmental Energy Security Indicators as Tools for Environmental Protection" in Mining and Environmental Protection-MEP 2019, University of Belgrade, Faculty of Mining and Geology (2019)
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Extensive vibrations of the belt conveyer drive electromotor of a bucket wheel excavator as a result of intesified wear-and-tear of its mount support
Vesna Damnjanović, Predrag Jovančić, Snežana Aleksandrović. "Extensive vibrations of the belt conveyer drive electromotor of a bucket wheel excavator as a result of intesified wear-and-tear of its mount support" in Journal of Vibroengineering (2017). https://doi.org/10.21595/jve.2016.17321
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Effectiveness Analysis of Different Bucket-wheel Excavators
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 ...Stevan Đenadić, Predrag Jovančić, Dragan Ignjatović, Miloš Tanasijević, Filip Miletić. "Effectiveness Analysis of Different Bucket-wheel Excavators" in 8th International Conference Mining and Environmental Protection, Sokobanja, 22-25 September 2021, University of Belgrade, Faculty of Mining and Geology, Belgrade, Serbia (2021)
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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... subsequently be converted into a time series. Let Ỹ(h) be the approximation of Y(i) obtained from the diagonal averaging step. If ỹ(i)mn stands for an element of a matrix Ỹ(i), then the jth term of the reconstructed series X̃(i) Ni =( x̃(i)1 , . . . , x̃(i)j , . . . , x̃(i)Ni ) is achieved by arithmetic ...
... subsequently be converted into a time series. Let Y (i) be the approximation of Y) obtained from the diagonal averaging step. If fmm stands for an element of a matrix yo, then the jth term of the reconstructed series xv = ( ge, Ly x), Ley x?) is achieved by arithmetic averaging i over all (m, 1) such ...Luka Crnogorac, Rade Tokalić, Zoran Gligorić, Aleksandar Milutinović, Suzana Lutovac, Aleksandar Ganić. "Gate Road Support Deformation Forecasting Based on Multivariate Singular Spectrum Analysis and Fuzzy Time Series" in Energies, MDPI (2021). https://doi.org/https://doi.org/10.3390/en14123710
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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. "Application of VIКOR method in the selection of an optimal splution of excavation “Borska Reka” ore deposit" in 9th International Conference Mining and Environmental protection MEP, 24 – 27 May 2023, Sokobanja, Serbia , Belgrade : University of Belgrade-Faculty of mining and geology (2023)
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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. "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" in Transportation Planning and Technology, Informa UK Limited (2023). https://doi.org/10.1080/03081060.2023.2245389
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Еоценска фауна југозападног дела Сирт басена (Либија)
Љупко Рундић, Мери Ганић (2020)Љупко Рундић, Мери Ганић. "Еоценска фауна југозападног дела Сирт басена (Либија)" in Записници Српског геолошког друштва, Српско геолошко друштво (2020)
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A bilingual digital library for academic and entrepreneurial knowledge management
A generic knowledge management process of organization, storage and retrieval of knowledge can suitably be fitted in a digital library. In the digital and knowledge age digital libraries can be used in knowledge management to handle intellectual assets and support knowledge creation. A multilingual digital library either stores content in more than one language or provides multilingual query access to monolingual content. In Serbia 18 of 308 scientific journals regularly published are bi-lingual, with papers simultaneously being in English ...... description of each text collection. Metadata are stored in Serbian and in English, where the attribute lang specifies the language of metadata element. Metadata elements provide information on: − text collections: text collection title (journal or project), ISSN1 and URL of the collection; ...Ranka Stanković, Cvetana Krstev, Biljana Lazić, Dalibor Vorkapić. "A bilingual digital library for academic and entrepreneurial knowledge management" in Proceeding of 10th International Forum on Knowledge Asset Dynamics — IFKAD 2015: Culture, Innovation and Entrepreneurship: connecting the knowledge dots, Bari, Italy, 10-12 June 2015, Bari : IFKAD (2015)
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An intelligent hybrid system for surface coal mine safety analysis
Nikola Lilić, Ivan Obradović, Aleksandar Cvjetić. "An intelligent hybrid system for surface coal mine safety analysis" in Engineering Applications of Artificial Intelligence (2010)
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Age of the Jurassic hemipelagic sediments from the Ljubiš area (Zlatibor Mt., SW Serbia)
Nikita Bragin, Nevenka Đerić (2020)... Geological Institute GEMINI, Belgrade, 187 p. DIMITRIJEVIĆ, M.N. & DIMITRIJEVIĆ, M.D. (1991): Triassic carbonate platform of the Drina-Ivanjica element (Dinarides).– Acta Geol. Hung., 34, 15–44. DJERIĆ, N., GERZINA, N. & SCHMID, M.S. (2007): Age of the Jurassic radiolarian chert formation from the ...Nikita Bragin, Nevenka Đerić. "Age of the Jurassic hemipelagic sediments from the Ljubiš area (Zlatibor Mt., SW Serbia)" in Geologia Croatica, Croatian Geological Survey (2020). https://doi.org/10.4154/gc.2020.11
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Availability as a dimension of energy security in the Republic of Serbia
Boban Pavlović, Dejan Ivezić (2016)There is a range of modern approaches and models in literature for the evaluation and determination of energy security, which are based on different parameters and indicators. For most of them, a common characteristic is emphasizing the avail ability of energy, as an important dimension for ensuring energy security. In this paper, concise overview of Serbian energy sectors is given and appropriate energy indicators are defined and determined. Selected indicators provide insight into the main components that characterize availability ...... 1/2 1/3 1 Once the initial pairwise comparison matrix is built, it is possible to derive the nor- malised pairwise comparison matrix, Anorm. Each element of the column of the initial matrix is divided by the sum of the elements of the same column: norm 1 , , 1, ,ij n ij i a A i j n a = = ...Boban Pavlović, Dejan Ivezić. "Availability as a dimension of energy security in the Republic of Serbia" in Thermal Science, National Library of Serbia (2016). https://doi.org/10.2298/TSCI160923303P
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Results of Recent Monitoring Activities on Landslide Umka, Belgrade, Serbia—IPL 181
Biljana Abolmasov, Uroš Đurić, Jovan Popović, Marko Pejić, Mileva Samardžić Petrović, Nenad Brodić (2021)... research within IPL181 Project will be focused on continued monitoring and analysing: (1) spatial patterns and relationships between landslide and element at risk, (2) proposing quantitative risk model and (3) landslide risk management, according to the Project goals. Those research objectives will ...Biljana Abolmasov, Uroš Đurić, Jovan Popović, Marko Pejić, Mileva Samardžić Petrović, Nenad Brodić. "Results of Recent Monitoring Activities on Landslide Umka, Belgrade, Serbia—IPL 181" in Understanding and Reducing Landslide Disaster Risk. WLF 2020. ICL Contribution to Landslide Disaster Risk Reduction, Springer, Cham (2021). https://doi.org/10.1007/978-3-030-60196-6_14
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Crystallography and Surface Oxidation of Stoichiometric Arsenopyrite from Šumadija-Kopaonik Pb-Zn/Polymetallic Ore District (Serbia)
Ivana Jelić, Aleksandar Pačevski, Aleksandar Kremenović, Aleš Šoster, Andreja Šestan, Janez Zavašnik (2023)The behaviour and stability of arsenopyrite largely depend on its crystal structure, but studies of crystallography and structural defects are scarce. For clarification, we investigated a series of natural arsenopyrite crystals from the polymetallic Pb-Zn-(±Cu,Ag,Au,Sb,Bi,W) Šumadija-Kopaonik ore district (Serbia) by powder X-ray diffraction (XRPD). Among them, samples from the Drenjak gold mineralisation showed near-stoichiometric FeAsS composition and were further investigated by conventional and high-resolution transmission electron microscopy methods. TEM revealed abundant planar crystallographic defects and epitaxial surface oxide layer ...Inorganic Chemistry, Condensed Matter Physics,General Materials Science, General Chemical Engineering, crystal structure, FeAsS, oxidation, TEM, XRPD... (EDS). The quantification was assessed by the Cliff-Lorimer ratio thin section method (four iterations), with the Si-K line as the ratio standard element and line [20]. The calculated composition, mean of 16 spot analyses, was determined as (wt%): Fe 34, As 47, S 19 (sum 100); (at%): Fe 33.2, As ...Ivana Jelić, Aleksandar Pačevski, Aleksandar Kremenović, Aleš Šoster, Andreja Šestan, Janez Zavašnik. "Crystallography and Surface Oxidation of Stoichiometric Arsenopyrite from Šumadija-Kopaonik Pb-Zn/Polymetallic Ore District (Serbia)" in Crystals, MDPI AG (2023). https://doi.org/10.3390/cryst13020278
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Early–Middle Jurassic brachiopods from Ponor Mountain, Western Balkan Mountains, Bulgaria; taxonomy, biostratigraphy and occurrence in the context of the early Toarcian Oceanic Anoxic Event
Barbara V. Radulović, Lubomir S. Metodiev, Neda Motchurova-Dekova, Platon Tchoumatchenco. "Early–Middle Jurassic brachiopods from Ponor Mountain, Western Balkan Mountains, Bulgaria; taxonomy, biostratigraphy and occurrence in the context of the early Toarcian Oceanic Anoxic Event" in Historical Biology (2023). https://doi.org/10.1080/08912963.2023.2190757
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Agates of the Lece Volcanic Complex (Serbia): Mineralogical and Geochemical Characteristics
Agate veins and nodules occur in the Lece Volcanic Complex (Oligocene-Miocene) situated in the south of Serbia and occupying an area of 700 km2. This volcanic complex is composed predominantly of andesites, with sporadic occurrences of andesite-basalts, dacites and latites, and features agate formations that have been very little investigated. This study focuses on five selected agate occurrences within the Lece Volcanic Complex, employing optical microscopy, scanning electron microscopy (SEM), X-ray powder diffraction analysis, inductively coupled plasma mass spectrometry ...Zoran Miladinović, Vladimir Simić, Nenad Nikolić, Nataša Jović Orsini, Milena Rosić. "Agates of the Lece Volcanic Complex (Serbia): Mineralogical and Geochemical Characteristics" in Minerals, MDPI AG (2024). https://doi.org/10.3390/min14050511