Претрага

Упит dcterms_creator_txt:Radović Predrag

350 items

  • Hydrodynamic analysis application of contaminated groundwater remediation to oil hydrocarbons

    Predrag Pajić, Aleksandar Čalenić, Dušan Polomčić, Dragoljub Bajić (2018)
    U ovom radu sagledana je primena hidrodinamičke analize u okviru odabrane remedijacione metode ,,pumpanja i tretiranja” kontaminiranih podzemnih voda ugljovodonicima, na primeru pretakališta rafinerije nafte u Pančevu. Primenjena hidrodinamička analiza predstavlja pravilan, a sve češće i neophodan pristup u savremenoj hidrogeologiji. Prethodnim hemijskim analizama uzoraka tla i podzemnih voda na istražno-osmatračkim objektima detektovano je zagađenje produktima nafte. Novoizvedena istraživanja obuhvatila su izvođenje 12 pijezometara različitih dubina, geoelektrično sondiranje tla, ,,in situ” merenja prisutnog kontaminanta, izdvojenog kao hidrofobna faza LNAPL, ...
    kontaminacija, matematički model, podzemne vode, remedijacija, ugljovodonici

  • Simulation of groundwater regime and quantification of groundwater balance by means of hydrodynamic analysis: Case of open-cast mine 'Jakovačka Kumša'

    Dušan Polomčić, Dragoljub Bajić, Jelena Ratković, Đorđije Božović, Predrag Pajić (2019)
    Hidrodinamička analiza, kao metodološki postupak, korišćena je za simulaciju režima i kvantifikaciju bilansa podzemnih voda na širem području Površinskog kopa „Jakovačka Kumša“. Istražni prostor obuhvata i deo beogradskog izvorišta podzemnih voda koje se nalazi u neposrednoj blizini površinskog kopa, u priobalju reke Save. Na površinskom kopu se vrši eksploatacija peska, koji se koristi kao građevinski materijal. Analizom i sintezom podataka koji se odnose na geološke i hidrogeološke ka-rakteristike područja, u radu je prikazan trodimenzionalni hidrogeološki model istražnog područja. Prevođenje ...
    hidrogeološki model, hidrodinamički model, izvorište podzemnih voda, numerička metoda konačnih razlika, Modflow

  • Određivanje prostorne distribucije vrednosti hidrauličkih parametara izdani: primer površinskog kopa „Radljevo“

    Dragoljub Bajić, Dušan Polomčić, Jelena Ratković, Predrag Pajić (2019)
    Najčešće se kalibracija hidrodinamičkih modela vršila manuelno - „probanjem“ sa različitim vrednostima hidrauličkih parametara i hidrauličkih karakteristika graničnih uslova. Ovakav način rada zahteva veliko znanje i iskustvo eksperta, pri čemu ostaje otvoreno pitanje da li dobijeno rešenje ima optimalan skup parametara. Primenom optimizacione metode, koja se zasniva na Gauss-Marquardt-Levenberg-ovom algoritmu, i PEST softvera, ...
    kalibracija hidrodinamičkog modela, PEST, koeficijent filtracije

  • Testing the energy value of different types of coal by the method of active thermography

    Stevan Đenadić, Ljubiša Tomić, Vesna Damnjanović, Predrag Jovančić, Dragutin Jovković (2020)
    In this paper, coal thermograms are presented and analyzed in order to determine their energy value. Two types of coal of different categories, brown and lignite, were selected for active thermographic imaging. The tested coal samples were processed before measurement so that they are similar in dimensions and have two plane-parallel smooth surfaces. The test samples were "primarily" heated under the same conditions and the process of their cooling was monitored by a thermal camera. "Then" they were cooled ...
    Infrared imaging, nondestructive testing, active thermography, coal.

  • A treatise about reliability in dating events of evolutionary history of brown trout Salmo cf. trutta (Actinopterygii) at Western Balkans: Impassable barriers, isolation of populations and assistance of geological timeframe

    Ana Marić, Danica Srećković Batoćanin, Dubravka Škraba Jurlina, Miloš Brkušanin, Jelena Karanović, Tamara Kanjuh, Vera Nikolić, Danilo Mrdak, Predrag Simonović (2023)
    Distribucija različitih haplotipova pastrmke u zavisnosti od geoloških dogadjaja.
    smeđa pastrmka, jadranska pastrmka, molekularni sat, evolucija, geološka istorija

  • Negative Impact of Backwater Levels of Danube River and its Tributaries to the Groundwater Regime in Meliorated Riverside Areas

    Predrag Pajić, Uroš Urošević, Dušan Polomčić, Milan Dimkić (2016)
    This paper describes updated calculation methodology of Danube backwater impact, occurred as a consequence of “Đerdap I” hydropower plant operation, onto the meliorated riverside areas. This methodology is based on hydrodynamic analysis of groundwater regime (size, duration, level and inflow changes) and quantification of melioration areas impairment which is caused by “Đerdap I” hydropower plant operation. By comparing the groundwater regime elements, obtained by variant hydrodynamic calculation in mathematical models for natural – not backed up and actual – ...
    HPP ''Djerdap 1'', backwater influence, groundwater regime, hydrodynamic analysis, melioration area, drainage system, additional energy engagement

  • Filling of dolines with aeolian sediments in the high-mountain karst of the Dinarides (Mt. Durmitor, Montenegro)

    Mirela Djurović, Violeta Gajić, Predrag Djurović (2022)
    Filling of dolines with aeolian sediments, one of the less frequently described ways in which they are filled, is analysed in the present study on an example of a doline in the high-mountain karst of the Dinarides. There is a series of deep dolines on a broad ridge (about 2450 m a.s.l.) on Mt. Durmitor (Montenegro) in the southeastern part of the Dinarides. The accumulation of very fine-grained sand that almost completely fills one of the dolines was analysed. ...
    Doline, Zapuna, Eolski sedimenti, Karst, Dinaridi, Crna Gora

  • 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
    ... Ignjatović, Predrag Jovančić, Stevan Đenadić, Ivan Janković, Ivica Ristović Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] The optimization of auxiliary machinery in open-cast lignite mines: a case study of bulldozers | Dragan Ignjatović, Predrag Jovančić, Stevan ...
    ... September 2019, Vrdnik, Serbia 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! !- University ог Belgrade – Faculty ог Mining and Geology, Belgrade, SERBIA, dragan ...

  • Sentiment Analysis of Serbian Old Novels

    Ranka Stanković, Miloš Košprdić, Milica Ikonić Nešić, Tijana Radović (2022)
    In this paper we present first study of Sentiment Analysis (SA) of Serbian novels from the 1840-1920 period. The preparation of sentiment lexicon was based on three existing lexicons: NRC, AFFIN and Bing with additional extensive corrections. The first phase of dataset refinement included filtering the word that are not found in Serbian morphological dictionary and in second automatic POS tagging and lemma were manually corrected. The polarity lexicon was extracted and transformed into ontolex-lemon and published as initial ...
    sentiment lexicon, sentiment analysis, distant-reading, machine learning, old novels

  • 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
    ... 2023-11-02 12:24:48 Crystal structure of K3EuSi2O7 Sabina Kovač, Predrag Dabić, Aleksandar Kremenović Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Crystal structure of K3EuSi2O7 | Sabina Kovač, Predrag Dabić, Aleksandar Kremenović | Journal of the Serbian Chemical ...
    ... J. Serb. Chem. Soc. 00(0) 1-10 (2021) UDC JSCS–10398 Original scientific paper 1 Crystal structure of K3EuSi2O7 SABINA Z. KOVAČ*, PREDRAG Z. DABIĆ and ALEKSANDAR S. KREMENOVIĆ University of Belgrade, Faculty of Mining and Geology, Department of Mineralogy, Crystallography, Petrology ...
    ... Novi Sad, Faculty of Sciences. OnLin e Fir st CRYSTAL STRUCTURE OF K3EuSi2O7 9 ИЗВОД КРИСТАЛНА СТРУКТУРА K3EuSi2O7 САБИНА З. КОВАЧ, ПРЕДРАГ З. ДАБИЋ и АЛЕКСАНДАР С. КРЕМЕНОВИЋ Универзитет у Београду, Рударско – геолошки факултет, Департман за минералогију, кристалографију, петрологију ...

  • Mogućnost infracrvene termografije pri detekciji štetnih gasova

    Stevan Đenadić, Vesna Damnjanović, Predrag Jovančić, Dragutin Jovković (2021)
    Curenje pojedinih gasova je opasnost koja može da izazove velike nezgode. Često je praćeno požarima i eksplozijama koji za posledicu mogu da imaju kako ljudske povrede, tako i štetan uticaj na ekologiju i ekonomiju. Da bi se izbegle takve situacije, preventivna inspekcija je od presudne važnosti. Curenje većine gasova se ne može uočiti golim okom a za otkrivanje i procenu stepena curenja može se koristiti tehnologija toplotnog snimanja (infracrvena termografija). U datom radu predstavljene su mogućnosti i ograničenja primene ...
    IC termografija, curenje gasa, termogram

  • Primena termografije u rudarstvu

    Stevan Đenadić, Vesna Damnjanović, Predrag Jovančić, Dragan Ignjatović, Dragutin Jovković, Filip Miletić (2019)
    Danas, gotovo da nema oblasti u nauci i tehnici u kojoj se Infracrvena termografija ne primenjuje kao metoda za lociranje i praćenje zagrejanih objekata ili tela, beskontaktnu procenu temperature površina, i nedestruktivno ispitivanje materijala. U radu su prikazane mogućnosti i perspektive primene ove metode u oblasti rudarstva.
    infracrvena termografija, rudarstvo, monitoring
    ... Stevan Đenadić, Vesna Damnjanović, Predrag Jovančić, Dragan Ignjatović, Dragutin Jovković, Filip Miletić Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Primena termografije u rudarstvu | Stevan Đenadić, Vesna Damnjanović, Predrag Jovančić, Dragan Ignjatović, Dragutin ...
    ... Univerzitet u Beogradu, Rudarsko-geološki fakultet 2 Prof. Dr Damnjanović Vesna, Univerzitet u Beogradu, Rudarsko-geološki fakultet 3 Prof. Dr Jovančić Predrag, Univerzitet u Beogradu, Rudarsko-geološki fakultet 4 Prof. Dr Ignjatović Dragan, Univerzitet u Beogradu, Rudarsko-geološki fakultet 5 Jovković Dragutin ...

  • Indeksi kontrole održavanja i korišćenja rotornog bagera

    Jovana Mitrović, Predrag Jovančić, Dragan Ignjatović, Stevan Đenadić, Filip Miletić (2023)
    Razvoj površinske eksploatacije se u velikom stepenu zasniva na svestranoj mehanizaciji rudarskih radova. Kako bi se zadovoljili potrebni kapaciteti, neophodna je primena savremene mehanizacije, velikih kapaciteta i pouzdanosti u radu. Naime, sa stepenom povećanja mehanizovanosti radova smanjuje se broj zaposlenih radnika, povećava produktivnost rada, smanjuju troškovi po jedinici proizvoda, a samim tim i povećava ekonomičnost površinske eksploatacije. Predmet istraživanja su rotorni bageri SRs 1200 koji predstavljaju samohodne mašine kontinuiranog dejstva namenjene za otkopavanje jalovine i korisne supstance na površinskim ...
    rudarstvo, rotorni bager, indeksi održavanja, indeksi korišćenja, TOPSIS

  • Industrija 4.0 - koncept prediktivnog održavanja 4.0 (PdM 4.0) u rudarstvu

    Predrag Jovančić, Vesna Damnjanović, Dragan Ignjatović, Miloš Tanasijević, Stevan Đenadić (2019)
    Četvrtu industrijsku revoluciju – Industriju 4.0 karakteriše upotreba cyber-fizičkih sistema. Da bi se postigla optimalna strategija održavanja (ali i eksploatacije), neophodno je razviti sisteme koji podržavaju napredne inteligentne sisteme održavanja ili tehnologije pametnog održavanja. Iz toga su proizašli postulati Prediktivnog održavanja 4.0 (PdM 4.0) koji definišu veoma blisku budućnost u oblasti održavanja tehničkih sistema pa i rudarske opreme. PdM 4.0 uključuje iskorišćenje snage veštačke inteligencije za stvaranje stalnog uvida u otkrivanje uzroka i anomalija u radu opreme, koje se ...
    rudarstvo, prediktivno održavanje PdM 4.0, Industrija 4.0

  • Izbor rotornih bagera za proces revitalizacije: primer rotornih bagera SRs 1200 u rudarskom basenu Kolubara

    Predrag Jovančić, Dragan Ignjatović, Stevan Đenadić, Filip Miletić, Goran Todorović, Dragan Novaković (2020)
    Revitalizacija je proces ili skup tehničkih zahvata na mašini kojim se vrši zamena svih dotrajalih ili oštećenih delova metalne konstrukcije. Sastavni deo procesa revitalizacije je i modernizacija zastarele elektro-mašinske opreme. Principi revitalizacije sasvim sigurno nisu sadržani u okviru redovnog godišnjeg ili dnevnog održavanja. Oni predstavljaju održavanje onih veličina koje su značajne za mašinu kao celinu (u ovom slučaju rotorni bager). U ovom radu su analizirani rotorni bageri oznake SRs 1200. Na površinskim kopovima rudarskog basena Kolubara takvih bagera ima ...
    Rotorni bageri, revitalizacija, SRs1200

  • Adaptive neuro-fuzzy prediction of operation of the bucket wheel drive based on wear of cutting elements

    Filip Miletić, Predrag D. Jovančić, Milos Milovančević, Dragan Ignjatović (2020)
    The capacity of the rotor excavator depends largely on the operation of the subsystem for digging. There is a great contribution to the correct and sharp teeth when the capacity is the highest. In the function of time, the teeth become clogged due to abrasive wear, or changes in their geometric shape. To analyze the bucket wheel drive in depend on wear of the cutting elements in this study adaptive neuro fuzzy inference system (ANFIS) approach was implemented. ANFIS ...
    Pogon rotornog točka, habanje, rezni elementi, ANFIS

  • 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
    ... Aleksandar Madžarević, Predrag Jovančić Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Production of electricity from coal-fired power plants and accompanying CO2 emissions: comparison of EU-27 and US | Uroš Djorgovski, Aleksandar Madžarević, Predrag Jovančić | In ...
    ... electricity from coal-fired power plants and accompanying CO: emissions: comparison of EU-27 and US Uroš Djorgovski!, Aleksandar Madžarević”, Predrag Jovančić? !Joint stock company Electric Power Industry of Serbia — Branch TPPs-OCMs Kostolac ŽUniversity of Belgrade – Faculty of Mining and Geology ...

  • 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

  • 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
    ... Evaluation Dejan Ivezić, Miloš Tanasijević, Predrag Jovančić, Radiša Đurić Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] A Fuzzy Expert Model for Availability Evaluation | Dejan Ivezić, Miloš Tanasijević, Predrag Jovančić, Radiša Đurić | Proceedings of the ...
    ... @rgf.bg.ac.rs Radisa Djuric TPPs-OCMs Kostolac Electric Power Industry of Serbia Kostolac, Serbia radisa.duric@te-ko.rs Predrag Jovancic Faculty of Mining and Geology University of Belgrade Belgrade, Serbia predrag.jovancic@rgf.bg.ac.rs Abstract—Each technical system ...

  • Application of the Fuzzy Model in the Evaluation and Selection of Hydraulic Excavators on Open-Pit Lignite Mine

    Stevan Đenadić, Miloš Tanasijević, Vladimir Milisavljević, Dragan Ignjatović, Predrag Jovančić (2021)
    The production of lignite in large open-pit mines is mainly performed with continuously operating equipment, where bucket-wheel excavators, bucket-chain excavators, belt conveyors, and spreaders are the basic machines. Smaller machines, usually of discontinuous operating nature, are commonly categorized as auxiliary machines. This paper presents the research related to the analysis of auxiliary machine parameters with the case study for a hydraulic excavator. The purpose of the analysis was to develop a model of rating quality of service of the ...
    Fuzzy theory, hydraulic excavator, selection, quality of service, asset management