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Упит dcterms_creator_txt:Hajdin Bojan

236 items

  • Double traveling valve increases rod-pump efficiency

    Miloš Petrović, Bojan Martinović, Milica Ješić, Miroslav Crnogorac (2023)
    Traditional sucker rod pumps (SRP) use a single traveling valve, but recent double traveling valve innovations have improved SRP performance and efficiency in field applications with double traveling valves installed in pumps with top mechanical seating. The valves sealed better and produced similar fluid volumes compared with the previous single-valve pumps. They also enabled a reduction in pump diameter and optimized usage of surface equipment. Overall, the double travel valve SRPs produced stable production rates and annual production targets.
    дубинска пумпа на клипним шипкама, производња нафте, ефикасност

  • Convective heat transfer in centrifugal pumps lifted wells: the case of South-Eastern Europe waxy wells

    Bojan Martinovic, Marija Živković, Branko Grubač (2021)
    Electric submersible pumps (ESP) are applied in wells where additional energy is needed to ensure discharge of the fluid to the surface through the tubing. At the discharge side of the pump the fluid has bigger velocity, thus the pump induces a forced convection between the fluid and the tubing inner surface. Understanding of convective heat transfer in wellbores and analyses of influential parameters provides a possibility to optimise value of convective heat transfer coefficient in order to avoid ...
    prenos toplote konvekcijom, ESP pumpa, svojstva fluida, problemi u radu bušotine

  • Productivity improvement with use of beam gas compressor: pilot test in Southeastern Europe mature field

    Bojan Martinović, Dušan Danilović, Branko Grubač, Robert Fadiga (2022)
    Most of the wells in the oilfield Turija are operating with sucker rod pumps, where casing pressure at around 15 bar, and with marginal production rates. The high value of casing pressure indicates high pressure on the face of the formation and depends directly on well productivity. In addition, with increasing value of the casing pressure gas column in the annulus is moving the dynamic fluid level near pump intake and more gas is entering the pump, it results ...
    beam gas compressor, BGC, increase productivity, sucker rod pump, SRP, mature field, artificial lift, production optimisation

  • Uniaxial compressive strength test before and after standard fire test on rock mass

    Stefan Mitrović, Goran Todorović, Bojan Kostić, Milica Mirković-Marjanović, Nikola Božović, Marija Krstić, Aleksandar Erić, Radovan Gospavić, Snežana Ilić, Aleksandar Kijanović (2022)
    ... Измењено: 2023-11-24 09:19:20 Uniaxial compressive strength test before and after standard fire test on rock mass Stefan Mitrović, Goran Todorović, Bojan Kostić, Milica Mirković-Marjanović, Nikola Božović, Marija Krstić, Aleksandar Erić, Radovan Gospavić, Snežana Ilić, Aleksandar Kijanović Дигитални ...
    ... Универзитета у Београду [ДР РГФ] Uniaxial compressive strength test before and after standard fire test on rock mass | Stefan Mitrović, Goran Todorović, Bojan Kostić, Milica Mirković-Marjanović, Nikola Božović, Marija Krstić, Aleksandar Erić, Radovan Gospavić, Snežana Ilić, Aleksandar Kijanović | Fifth symposium ...
    ... Papić (Eds) Uniaxial compressive strength test before and after standard fire test on rock mass Stefan Mitrovića , Goran Todorovića , Bojan Kostićb , Milica Mirković Marjanovićc, Nikola Božovićc , Marija Krstićc, Aleksandar Erićd, Radovan Gospavića , Snežana Ilićc , Aleksandar Kijanovićc ...

  • Geoloski profil planine Avale (severna Šumadija) - uvid u litostratigrafiju i tektonske strukture

    Marinko Toljić, Bojan Glavaš-Trbić, Maja Maleš, Nikola Ranđelović (2022)
    Mezozojske formacije Šumadije dele tektonsko-stratigrafsku evoluciju južnijih delova suture jedinica Adrijskog i Evropskog afiniteta, uključujući gornjojursku obdukciju, krednu subdukciju i paleogenu kontinentalnu koliziju. Finalni rezultat dugovremene evolucije u geodinamički složenom ambijentu su komplikovani tektonski i litostratigrafski odnosi različitih mezozojskih formacija suture. Geološki profil kroz planinu Avalu omogućava uvid u skoro potpunu sukcesiju mezozojskih formacija i prostorne pozicije i kinematiku značajnih tektonskih struktura najsevernijih segmenata suture u Šumadiji. U tektonskom kontekstu, mezozojske formacije okoline Beograda najčešće su interpretirane kao deo Istočne ...
    sutura, parafliš, bazalna navlaka, transkurentni rased

  • Горњокредне творевине северозападне Србије

    Bojan M. Glavaš-Trbić (2013-11-26)
    У раду су приказане палеогеографске карактеристике и геотектонски положајширег подручја (Јадарског блока и Вардарске зоне) које су утицале на условеталожења, односно карактеристике горњокредних творевина на простору данашњесеверозападне Србије.Описани су карактеристични локални геолошки стубови уз приказ њиховихлитолошких, биостратиграфских и седиментолошких карактеристика. При томе сукоришћена досадашња сазнања о предметном простору изложена у домаћим радовима,и извршена је компарација и корелација са подацима суседних терена, ширеперитетиског ареала.Истраживања у првој фази су вршена на међусобно удаљеним и релативномалим профилима – често само ерозионим крпама ...
    горња креда, стратиграфија, микрофосили, макрофосили, Јадарскиблок-Вардарска зона, СЗ Србија

  • Heavy metals in lignite and soil of Kostolac-Kovin coal basin, eastern Serbia - comparative analysis with selected cities in Serbia, region, Europe and world

    Bogoljub Vučković, Bojan Dimitrijević (2023)
    The Kostolac-Kovin coal basin with an area of 320 km2, with 5 separate layers of coal and with a total of about 5.7 Bt of geological resources and reserves represents an exceptional potential for coal production in Serbia. The coal resources listed in this way are not fully exploitable, but they represent potential for consideration. In this paper, we deal with the geochemical characteristics of coal seams and perform a comparative analysis of coal affectation on the environment. With ...
    lignite, heavy metals, concentrations
    ... REGION, EUROPE AND WORLD Bogoljub Vučković!, Bojan Dimitrijević? !Joint stock company „Elektroprivreda Srbije”, RB Kolubara, Lazarevac, Serbia ?University of Belgrade, Faculty of Mining and Geology, Belgrade, Serbia bogoljub.vuckovic(a)eps.rs, bojan dimitrijevic(Q0)rgf.bg.ac.rs 4bstract:The K ...
    ... soil of Kostolac-Kovin coal basin, eastern Serbia - comparative analysis with selected cities in Serbia, region, Europe and world Bogoljub Vučković, Bojan Dimitrijević Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Heavy metals in lignite and soil of Kostolac-Kovin ...
    ... Kostolac-Kovin coal basin, eastern Serbia - comparative analysis with selected cities in Serbia, region, Europe and world | Bogoljub Vučković, Bojan Dimitrijević | 9th International Conference Mining and Environmental Protection, 24–27. May 2023, Sokobanja | 2023 | | http://dr.rgf.bg.ac.rs/s/repo/item/0008215 ...

  • Геомеханички мониторинг у површинској експлоатацији

    Владимир Чебашек, Александар Милутиновић, Бојан Димитријевић, Небојша Гојковић (2010)

  • 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

  • BEYOND 2020 - Geology explorations and open pit activities affectation in reclamation designing in Kolubara Coal Mines (KCM) Serbia, new considerations

    Bojan Dimitrijević, Bogoljub Vučković, Radmila Gaćina (2023)
    Geology explorations in KCM runs from 1936. year up to these days and still ongoing. Results in >7,200 drill holes with ≈600,000 m of core drilling and gave lignite ore resources of > 4,1Bt, which 1,15Bt are excavated since 1986. of XIX up to early years of XXI century. For further mining operations in open pits stay 1,5Bt of lignite. Under waste heaps are ≈80 km2, additional 85 km2 should be filled. All of that masses/areas were, are ...

  • Terminological and lexical resources used to provide open multilingual educational resources

    Biljana Lazić, Danica Seničić, Aleksandra Tomašević, Bojan Zlatić (2016)
    Open educational resources (OER) within BAEKTEL (Blending Academic and Entrepreneurial Knowledge in Technology enhanced learning) network will be available in different languages, mostly in the languages of Western Balkans, Russian and English. University of Belgrade (UB) hosts a central repository based on: BAEKTEL Metadata Portal (BMP), terminological web application for management, browse and search of terminological resources, web services for linguistic support (query expansion, information retrieval, OER indexing, etc.), annotation of selected resources and OER repository on local edX ...
    otvoreni obrazovni resursi, leksički resursi, obrada prirodnih jezika, terminologija
    ... Aleksandra Tomašević, Bojan Zlatić Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Terminological and lexical resources used to provide open multilingual educational resources | Biljana Lazić, Danica Seničić, Aleksandra Tomašević, Bojan Zlatić | The Seventh ...
    ... danica.senicic@student.uclouvain.be ALEKSANDRA TOMAŠEVIĆ University of Belgrade, Faculty of Mining and Geology, aleksandra.tomasevic@rgf.bg.ac.rs BOJAN ZLATIĆ University of Belgrade, Faculty of Mining and Geology, bojan.zlatic@rgf.bg.ac.rs Abstract: Open educational resources (OER) within BAEKTEL (Blending ...

  • Conversion of land areas after coal mine closure and reclamation

    Radmila Gaćina, Bojan Dimitrijević, Sanja Bajić (2023)
    Otkopavanje uglja površinski i podzemno praćeno je degradacijom zemljišta, promenom formiranja predela i izmenom flore i faune. Od velikog značaja je razvoj novih naučno utemeljenih pristupa obnovljanje antropogeno poremećenih predela zasnovanih na formiranju rekultivacionih i rudarskih tehnologija. Apsolutno je neophodno obezbediti sveobuhvatno kvalitetno očuvanje zemljišnih i vodnih resursa i odrediti rekultivisano zemljište za novu namenu. U ovom članku je dat pregled najpopularnijih metoda rekultivacije zemljišta i mogućnosti rekultivacije zemljišta nakon završetka rekultivacije i zatvaranja rudnika uglja.
    rekultivacija, melioracija, revitalizacija, otkopavanje uglja, održivi razvoj
    ... mine closure and reclamation Radmila Gaćina, Bojan Dimitrijević, Sanja Bajić Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Conversion of land areas after coal mine closure and reclamation | Radmila Gaćina, Bojan Dimitrijević, Sanja Bajić | 9th International ...
    ... Conference MINING AND ENVIRONMENTAL PROTECTION May 2023, Serbia CONVERSION OF LAND AREAS AFTER COAL MINE CLOSURE AND RECLAMATION Radmila Gaćina, Bojan Dimitrijević, Sanja Bajić University of Belgrade, Faculty of Mining and Geology, Belgrade, Serbia radmila.gacinarpf.bg.ac.rs; bojan.dimitrijevicorgf ...

  • LRMI markup of OER content within the BAEKTEL project

    Ranka Stanković, Daniela Carlucci, Olivera Kitanović, Nikola Vulović, Bojan Zlatić (2015)
    ... Olivera Kitanović, Nikola Vulović, Bojan Zlatić Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] LRMI markup of OER content within the BAEKTEL project | Ranka Stanković, Daniela Carlucci, Olivera Kitanović, Nikola Vulović, Bojan Zlatić | The Sixth International ...
    ... and Geology, olivera.kitanovic@rgf.bg.ac.rs NIKOLA VULOVIĆ University of Belgrade, Faculty of Mining and Geology, nikola.vulovic@rgf.bg.ac.rs BOJAN ZLATIĆ University of Belgrade, Faculty of Mining and Geology, bojan.zlatic@rgf.bg.ac.rs Abstract: This paper outlines the approach to tagging ...

  • Geodynamics of basins above subducted slabs: An integrated modelling study of tectonics, sedimentation, and magmatism in the Timok Magmatic Complex

    Uros Stojadinovic, Marinko Toljic, Branislav Trivic, Radoje Pantovic, Danica Sreckovic-Batocanin, Nemanja Krstekanic, Bojan Kostic, Milos Velojic, Jelena Stefanovic, Nikola Randjelovic, Maja Males (2024)
    Timok Magmatic Complex, Neotethys subduction, basin geodynamics, analogue modelling

  • Application of the VIKOR Method for Selecting the Purpose of Recultivated Terrain after the End of Coal Mining

    Radmila Gaćina, Sanja Bajić, Bojan Dimitrijević, Tomislav Šubaranović, Čedomir Beljić, Dragoljub Bajić (2024)
    reclamation, coal, sustainable development, multi-criteria decision making, VIKOR method

  • Linear-motor plunger pump increases lifting efficiency

    Bojan Martinović, Dušan Đekić, Dušan Danilović, Pavel Isaev (2022)
    plunger, linear, motor, pumps

  • Komparacija metoda XRF i ICP-MS na uzorcima uglja i produkata sagorevanja

    Branko Kostić, Dejan Prelević, Sabina Kovač, Ksenija Eraković, Dragana Životić (2022)
    Ugljevi niskog ranga – ligniti u Republici Srbiji predstavljaju glavnu energetsku sirovinu koja se koristi za proizvodnju električne energije. Rudarstvo u Srbiji doprinosi bruto dodatoj vrednosti sa 1,8% (2020; https://publikacije.stat.gov.rs/). Sagorevanjem ugljeva niskog ranga u termoelektranama generišu se velike količine elektrofilterskog pepela i pepela, koje često predstavljaju jedan od izvora zagađenja životne sredine usled sadržaja toksičnih elemenata. Dalja upotreba produkata sagorevanja zavisi od njihovog sastava i sadržaja toksičnih mikroelemenata. Svakodnevno sagorevanje lignita u termoelektranama uslovljava konstantan monitoring potencijalno toksičnih ...
    ugalj, produkti sagorevanja, XRF, ICP-MS

  • Anisotropic grossular–andradite garnets: Evidence of two stage skarn evolution from Rudnik, Central Serbia

    Bojan Kostić, Danica Srećković-Batoćanin, Petyo Filipov, Pavle Tančić, Kristijan Sokol (2021)
    This paper presents LA-ICP-MS data for garnets from the Rudnik skarn deposit (Serbia), which range from Grs45–58Adr40–52Alm2–3 in the core and Adr70–97Grs2–29Sps1 in the rim displaying anisotropy and zoning. In spite of wide compositional variations the garnets near the end-member of andradite (Adr > 90) are generally isotropic. Fe-rich rims exhibit LREE depletion and flat HREE pattern with weak negative Eu anomaly, including higher As and W contents. On the other side, the Fe-poorer core shows flat REE pattern ...
    grandite, garnets, skarn, Rudnik
    ... Serbia Bojan Kostić, Danica Srećković-Batoćanin, Petyo Filipov, Pavle Tančić, Kristijan Sokol Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Anisotropic grossular–andradite garnets: Evidence of two stage skarn evolution from Rudnik, Central Serbia | Bojan Kostić ...
    ... 72.1.2 www.geologicacarpathica.com Anisotropic grossular–andradite garnets: Evidence of two stage skarn evolution from Rudnik, Central Serbia BOJAN KOSTIĆ1, , DANICA SREĆKOVIĆ-BATOĆANIN1, PETYO FILIPOV2, PAVLE TANČIĆ3 and KRISTIJAN SOKOL1 1Faculty of Mining and Geology, University of Belgrade ...

  • Kako napraviti održivi plan upravljanja odvodnjavanjem?

    Dragoljub Bajić, Dušan Polomčić (2020)

  • Solving dewatering problems using fuzzy MCDM methods for engineering-geological surveys

    Dragoljub Bajić (2022)