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975 items

  • Примена ПСП пумпи за експлоатацију вискозних флуида

    Алекса Трифуновић (2024)
    Производња парафинске нафте се током историје одвијала уз помоћ дубниских клипних пумпи, све до појаве ПСП система који су показали боље каратеристике и већу ефикасност. Функционални дизајн пумпе омогућава производњу вискозних и абразивних мултифазних флуида, уз ниска капитална улагања. У раду је анализирана проблематика рада укључују губитке протока флуида, производњу песка, оштећење клипних шипки и тубинга и сам притисак на дну бушотине. Рађена је студија случаја за нафно лежиште „М“ у коме је приказан цео производни век почевши од ...
    парафинска нафта, систем ПСП, производња нафте, студија случаја
    ... Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs YuunBepaurer y Beorpajty PynapcKo-reo.:otmiku (bakyarTeT Macrep pajnt TipumeHa IHICII nymnu 3a eKcn.ioaTalnuHjy BHCKO3HHX ...

  • Prognoza operativne efikasnosti aktivnog podzemnog rudnika zasnovana na teoriji sivih sistema

    Svetlana M. Štrbac-Savić (2016-06-10)
    Efikasnost predstavlja preduslov za opstanak svake rudarske kompanije, posebno u uslovima izuzetno konkurentnog trţišnog okruţenja kao što je to rudarska industrija. Efikasnost oznaĉava sposobnost kompanije da ispuni svoje kratkoroĉne ili dugoroĉne ciljeve. Operativna efikasnost se definiše kao odnos izmeĊu ulaznih parametara potrebnih za odvijanje proizvodnje i pokazatelja dobijenih proizvodnjom. U kontekstu rudarskog poslovanja, operativna efikasnost se odnosi na vreme potrebno da se mineralno dobro transformiše u novĉana sredstva. Visoka operativna efikasnost se postiţe kada se ostvari prava kombinacija karakteristika ...
    podzemni rudnik, operativna efikasnost, prognoza, teorija sivih sistema, stohastiĉke diferencijalne jednaĉine, simulacija
    ... publications. - The Repository is available at: www.dr.rgf.bg.ac.rs UNIVERZITET U BEOGRADU RUDARSKO-GEOLOŠKI FAKULTET Svetlana M. Štrbac-Savić PROGNOZA OPERATIVNE EFIKASNOSTI AKTIVNOG PODZEMNOG RUDNIKA ZASNOVANA NA TEORIJI SIVIH SISTEMA doktorska disertacija ...
    ... prodaje moţe da izazove poslovni gubitak. 3.4 Teorija sivih sistema Teoriju sivih sistema predloţio je Julong Deng 1982. godine [DENG82]. Teorija sivih sistema je multidisciplinarna teorija koja modeluje nedeterministiĉke sisteme, u kojima su informacije nepotpune ili nepouzdane. Naziv „sivi― ...
    ...   (3.27) Uticajne promenljive sistema ne utiĉu u istoj meri u promenu glavne vrednosti sistema. Siva relaciona analiza je deo Teorije sivih sistema. Cilj sive relacione analize je utvrĊivanje stepena relevantnosti svake promenljive sistema. Ona se koristi za utvrĊivanje primarnih faktora ...

  • Mogućnost intenziviranja efekata provetravanja otkopnih radilišta u slučaju vrlo složenih ventilacionih sistema (Primer rudnika Zletovo" - Dobrevo)"

    Komnen Đinović (1980)
    Otkopna radilišta, provetravanje, ventilacioni sistem

  • Optimizacija proizvodno-transportnog gasnog sistema SR. Srbije sa posebnim osvrtom na podzemno skladište kao sekundarni izvor energije

    Božidar Prstojević (1981)
    Gasni sistem, podzemno skladište, Srbija

  • Određivanje optimalnog sistema otvaranja i osnovne pripreme grupisanih  boksitnih rudnih tela

    Slobodan Majstorović (1997)
    Sistem otvaranja, priprema, boksitne rude

  • Razvoj prostornog informacionog sistema rudnika sa podzemnom eksploatacijom uglja na primeru rudnika " Soko", Soko banja

    Aleksandar Milutinović (2007)
    Informacioni sistemi, podzemna eksploatacija, Soko

  • Modeliranje sistema upravljanja zaštitom životne sredine u rudarsko-energetskim kompleksima

    Jelena R. Malenović - Nikolić (2016-07-12)
    Efikasnost funkcionisanja sistema upravljanja zaštitom životne sredine u rudarskoenergetskimkompleksima zavisi od stepena sprovođenja usvojene politike zaštiteživotne sredine i primene preventivnih mera zaštite životne sredine. Nedostatakfinansijskih sredstava za unapređivanje tehnologije eksploatacije, transporta, pripreme iprerade energetskih mineralnih sirovina u našim rudarsko-energetskim kompleksima,negativno utiče na ostvarivanje ciljeva zaštite životne sredine, a posledice radnihaktivnosti rudarsko-energetskih kompleksa dovode do smanjenja nivoa kvalitetavazduha, vode i zemljišta...
    rudarsko-energetski kompleks, životna sredina, sistem upravljanja,višekriterijumsko odlučivanje, modeliranje
    ... access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs UNIVERZITET U BEOGRADU Rudarsko-geološki fakultet Jelena R. Malenović Nikolić MODELIRANJE SISTEMA UPRAVLJANJA ZAŠTITOM ŽIVOTNE SREDINE U RUDARSKO-ENERGETSKIM KOMPLEKSIMA ...
    ... definisanje rangova i Modeliranje sistema upravljanja zaStitom Zivotne sredine u rudarsko-energetskim kompleksima 1 aij . T= Vj 6= 12,34. (7) Suma elemenata matrice poredenja podkriterijuma i aspekata zivotne sredine, u kolonama, izraCunava se na osnovu formule: T, =-Y4_ at i = 1,2,3,4. (8) Vrednost vektora ...
    ... Danskoj za razvoj sistema integrisanog upravljanja, na osnovu Dansk standarda (Sistem menadžmenta-vodič za integraciju Modeliranje sistema upravljanja zaštitom životne sredine u rudarsko‐energetskim kompleksima 15 sistema menadžmenta) [10]. Posebno se razmatra sistem menadžmenta, a kao ...

  • 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
    ... (Qav = 3.48 m?/s at 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 ...
    ... 5 t-i Š k k - - -j |j k_ -i -j -i -i e E SBSBSSBS BBB R B B G B BBB a dii 0 š . a bvu.ž·ižšjžrgozn |—g.s. at Manasija Monastery —-g:5. at Svilajnac |—C-g5. at Manasija Monastery —-g.5. at Svilajnac • 180 . 160 s s o : z a : o g 10 P Ž ž Š w š š k i 33 Š o |}] E 40 || > o LJ 2808 888 8#8 ...
    ... records, at the beginning of July 1999 the discharge at the Manasija Mon- astery was about 60 m?/s higher than at Svilajnac, which is impossible. The reason for this deviation might be that the flood curve was not well defined (less likely) or that the Resava River burst its banks at the Manasija ...

  • Study of the Synergetic Effect of Co-Pyrolysis of Lignite and High-Density Polyethylene Aiming to Improve Utilization of Low-Rank Coal

    Ivan Kojić, Achim Bechtel, Nikoleta Aleksić, Dragana Životić, Snežana Trifunović, Gordana Gajica, Ksenija Stojanović (2021)
    Polimeri i plastika, opšta hemija
    ... lignite at 400 ◦C; Lignite 450—pyrolysis of lignite at 450 ◦C; Lignite 500— pyrolysis of lignite at 500 ◦C; Lignite 550—pyrolysis of lignite at 550 ◦C; Lignite 600—pyrolysis of lignite at 600 ◦C; high-density polyethylene (HDPE) 400—pyrolysis of HDPE at 400 ◦C; HDPE 450—pyrolysis of HDPE at 450 ◦C; ...
    ... was used: heating from 80 to 300 ◦C at a rate of 2 ◦C/min, isothermal at 300 ◦C for 20 min, then heating from 300 to 310 ◦C at a rate of 10 ◦C/min, and finally isothermal at 310 ◦C for 1 min. The injector temperature was 250 ◦C; the interface (transfer line) was kept at 280 ◦C; whereas temperatures of ion ...
    ... ◦C; HDPE 500—pyrolysis of HDPE at 500 ◦C; HDPE 550—pyrolysis of HDPE at 550 ◦C; HDPE 600—pyrolysis of HDPE at 600 ◦C; Lignite/HDPE 400—pyrolysis of lignite/HDPE mixture at 400 ◦C (experimental yield); Lignite/HDPE 450—pyrolysis of lignite/HDPE mixture at 450 ◦C (experimental yield); Lignite/HDPE 500— ...

  • 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

  • Model inteligentnog sistema adaptivnog upravljanja procesom prerade rude

    Ivana M. Jovanović (2016-01-13)
    U oblasti procesa prerade rude, flotacijska koncentracija predstavlja jednu od najznačajnijih i najčešće primenjivanih metoda separacije korisnih od nekorisnih minerala. Samim tim, veoma je važno osigurati uspešan rad flotacijskog postrojenja kroz dostizanje zadovoljavajućih tehno-ekonomskih pokazatelja. Cilj upravljanja procesom flotacijske koncentracije je upravo optimizacija kvaliteta i iskorišćenja korisne komponente u koncentratu uz maksimizaciju profita. Shodno tome, istraživanja na polju modelovanja i upravljanja ovim procesom zauzimaju značajno mesto u praksi kontolnog inženjenringa.Teorijska istraživanja u okviru doktorske disertacije obuhvatila su analizu položaja ...
    flotacijska koncentracija, modelovanje, upravljanje, inteligentni sistem, soft kompjuting, fazi logika, veštačke neuronske mreže
    ... um ul at iv no is ko riš će nj e, % Srednji prečnik zrna, μmVreme flotiranja, s 100 200 300 400 500 600 700 800 100 50 150 200 250 K um ul at iv no is ko riš će nj e, % 20 40 60 80 b)a) Slika 23. Rezultati simulacije procesa flotacije na bazi fazi logičkog sistema zaključivanja: ...
    ... access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs UNIVERZITET U BEOGRADU RUDARSKO-GEOLOŠKI FAKULTET Ivana M. Jovanović MODEL INTELIGENTNOG SISTEMA ADAPTIVNOG UPRAVLJANJA PROCESOM PRERADE RUDE doktorska disertacija ...
    ... (2008b), Jain (2013)]. Takagi–Sugeno sistem je po mnogo čemu sličan Mamdani sistemu. Glavna razlika između njih je u konsekvenci fazi pravila. Naime, tipično fazi pravilo kod Takagi–Sugeno sistema ima oblik: I. Jovanović, MODEL INTELIGENTNOG SISTEMA ADAPTIVNOG UPRAVLJANJA PROCESOM PRERADE ...

  • Microstructural and magnetic properties of electrospun hematite/cuprospinel composites

    Mira Ristić, Aleksandar Kremenović, Michael Reissner, Željka Petrović, Svetozar Musić (2020)
    Phase composition, microstructural and magnetic properties of electrospun hematite/cuprospinel composites were investigated. Samples were synthesized starting with 0 to 10 mol% of copper relative to iron. The round shape of reference electrospun fbres was preserved upon their heating up to 600 °C in air, whereas at 700 °C hollow substructure was additionally formed. In these reference samples the presence of hematite phase was detected by XRPD. A small amount (traces) of Fe3O4 /γ-Fe2O3 was also found, due to the ...
    Electrical and Electronic Engineering, Condensed Matter Physics, Atomic and Molecular Physics and Optics, Electronic, Optical and Magnetic Materials

  • Hydrographic and hydrological characterization of the Vodenička and Rosomačka rivers

    Vesna Ristić Vakanjac, Marina Čokorilo Ilić, Dušan Polomčić, Dragoljub Bajić, Jelena Ratković (2017)
    The Visočica River rises in Bulgaria, on the Berovo Mountain. Its course in Bulgaria is 16.7 km long. It enters Serbia near the village of Donji Krivodol. Up to the village of Pakleštica, or the beginning of Lake Zavoj, its right-bank tributaries are the Krivodolštica, the Vodenička, the Rosomačka and the Dojkinačka. There are no left-bank tributaries. Among the tributaries, water levels and discharges are gauged only on the Dojkinačka River. The Vodenička had also been gauged but only ...
    hydrographic characteristics, river discharge, the Vodenička River, the Kamenička River
    ... a n n u a l d is c h a rg e Q ( m 3 /s ) The Visocica at Izatovac The Visocica at V. Ržana The Visocica at Braćevci The Visocica at Pakleštica The Dojkinacka atV. Ržana Figure 6 Monthly discharge distributions at the studied gauging stations Слика 6 Унутаргодишње расподеле протицаја ...
    ... on the Visočica. However, three of them have been decommissioned: at Pakleštica, Visočka Ržana and Izatovac. The only remaining station is at Braćevci. For their own needs, Pirot HPP activated the station at Pakleštica in 1990 and at Visočka Ržana in 2011. Based on available data, the paper presents ...
    ... RHMZ had set up three gauging stations on the Visočica: at Pakleštica (which was in service from 1959 to 1990), at Visočka Ržana (from 1958 to 2005), and at Izatovac (from 1963 to 1992). There was another gauging station on the Vodenička, at Kamenica, which was used to monitor water levels and discharges ...

  • Understanding the effect of synthesis and sintering temperature on the functional properties of barium titanate/cobalt ferrite composites

    Marija Šuljagić, Aleksandar Kremenović, Ivan Petronijević, Adis Džunuzović, Miljana Mirković, Vladimir Pavlović, Ljubica Anđelković (2023)
    To investigate the effect of synthesis procedure and sintering temperature on the functional properties of perovskite/spinel ceramics, BaTiO3/CoFe2O4 composites were prepared by thermal decomposition, coprecipitation, and microemulsion method, and sintered at 1150°C and 1300°C. The phase composition and morphology of as-prepared powders as well as sintered ceramics were thoroughly examined by X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM) coupled with electron dispersive spectroscopy (EDS). The dielectric and ferroelectric measurements were performed in detail. Generally, the ...
    Perovskite/spinel ceramics, Multiferroic, Sintering, Influence of synthesis method

  • Synthesis and characterization of high-pressure and high-temperature sphene (CaTiSiO5)

    Jelena Pantić, Vladimir Urbanovich, Vesna Poharc-Logar, Bojan Jokić, Marija Stojmenović, Aleksandar Kremenović, Branko Matović (2014)
    Sphene (CaTiSiO5), a calcium titanosilicate ceramic has been prepared from a powder mixture of CaCO3, TiO2 and SiO2 using vibro-milling for homogenization and activation of precursors. During the highpressure and high-temperature synthesis (HPS) process at 4 GPa and 1,200 °C, sphene undergoes into phase transition, from room-temperature phase P21/a to high-temperature phase A2/a. Evidence of that structural phase transition is given in this paper using infrared, Raman spectroscopy and X-ray powder diffraction. Rietveld refinement was employed to get the ...
    Sphene, Phase transition, Raman spectroscopy, X-ray diffraction, SEM, IR

  • 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

  • Application of Peleg model on mass transfer kinetics during osmotic dehydratation of pear cubes in sucrose solution

    Vesna Pavelkić, Tanja Brdarić, Marija Petrović, Gavrilo Šekularac, Milica Košević, Lato Pezo, Marija Ilić (2015)
    The applicability of Peleg model was investigated for predicting mass transfer kinetics during the osmotic dehydration (OD) process of pears, at different concentrations (40, 60 and 70%, w/w) and temperatures (20, 35 and 50 °C) of sucrose solution. Increase in sucrose solution concentration resulted in higher water loss (WL) and solid gain (SG) values through the osmotic treatment period. After 360 min of osmotic treatment of pears, WL ranged from 23.71 to 31.68% at 20 °C, from 24.80 to ...
    осмотска дехидрација, крушкa, кинетика, температурни ефекат, Пелег модел

  • An aproach to Implementation of blended learning in a university setting

    Ivan Obradović, Ranka Stanković, Olivera Kitanović, Jelena Prodanović (2011)
    ... support for all active courses covering seven educational profiles, three at the Mining department and four at the Geology department, with a total of 363 courses at undergraduate studies, 254 at master studies and 135 at doctoral studies. The courses supported by the portal involve a teaching ...
    ... FORWARD: MOODLE AT FMG The introduction of Moodle at FMG represented a leap forward in the blended learning system. In 2009, a number of teachers and teaching assistants started expressing their interest in functionalities that were not supported by the existing FMG CMS, and at the same time ...
    ... process. Finally, depending on the nature of the courses offered at FMG, other software tools are also being used in the learning process, especially within ICT oriented courses. The current state of the blended learning approach at FMG will be illustrated by two courses, one offered to students ...

  • Analiza rada BTO sistema u uslovima kolubarskog ugljenog basena radi utvrđivanja strukture neproizvodnog vremena

    Radmila Žunić (1989)
    BTO sistem, ugljeni basen, neproizvodno vreme

  • Određivanje optimalnog broja transportnih jedinica diskontinualnih sistema u rudnicima sa podzemnom eksploatacijom

    Zdravko Bundalo (1995)
    Transportne jedinice, diskontinualni sistemi, podzemna eksploatacija