Претрага
828 items
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Mineralni i hemijski sastav čestica u atmosferi zone Kolubarskog basena i uticaj na životnu sredinu
Željko R. Cvetković (2013-11-18)Čestice iz vazduha su prikupljane u blizini termoelektrane i površinskih kopovarudnika uglja u Kolubarskom basenu. Izmereni srednji sadržaji koncentracija rastvornih,nerastvornih i ukupnih taložnih materija na godišnjem nivou prelaze 200 mg/m2dan (K-1, K-3, K-4, K-5). Distribucija čestica na svim lokacijama klasifikovana je na česticeveličine veće od 10 μm, zatim na čestice veličine od 10 μm do 2,5 μm i klase česticaveličine ispod 2,5 μm. Ovakva podela je dala odnos koncentracija inhalatornih irespiratornih čestica po mernim mestima. Skenirajuća elektronska mikroskopija jepokazala ...mineral, četica, prašina, leteći pepeo, aerosediment, PM10, teški metali,koncentracija, veličina čestice, Kolubara... 0% 20% 40% 60% 80% 100% K-1 K-2 K-3 K-4 K-5 K-6 K-7 K-8 K-9 K-10 K-11 K-12 F ( % ) 2,5 5 7,5 10 12,5 15 17,5 20 22,5 25 >25 Veličina čestica (µm) April 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% K-1 K-2 K-3 K-4 K-5 K-6 K-7 K-8 K-9 K-10 K-11 K-12 F ( % ) 2,5 5 7,5 10 12 ...
... 0% 20% 40% 60% 80% 100% K-1 K-2 K-3 K-4 K-5 K-6 K-7 K-8 K-9 K-10 K-11 K-12 F ( % ) 2,5 5 7,5 10 12,5 15 17,5 20 22,5 25 >25 Veličina čestica (µm) Jun 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% K-1 K-2 K-3 K-4 K-5 K-6 K-7 K-8 K-9 K-10 K-11 K-12 F ( % ) 2,5 5 7,5 10 12 ...
... (µm) Jul 0% 20% 40% 60% 80% 100% K-1 K-2 K-3 K-4 K-5 K-6 K-7 K-8 K-9 K-10 K-11 K-12 F ( % ) 2,5 5 7,5 10 12,5 15 17,5 20 22,5 25 >25 Veličina čestica (µm) Avgust 0% 20% 40% 60% 80% 100% K-1 K-2 K-3 K-4 K-5 K-6 K-7 K-8 K-9 K-10 K-11 K-12 F ( % ) 2,5 5 7,5 10 12,5 15 17,5 ...Željko R. Cvetković. "Mineralni i hemijski sastav čestica u atmosferi zone Kolubarskog basena i uticaj na životnu sredinu" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2013-11-18)
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Mineralni i hemijski sastav čestica u atmosferi zone Kolubarskog basena i uticaj na životnu sredinu
Željko R. Cvetković (2013-11-18)Čestice iz vazduha su prikupljane u blizini termoelektrane i površinskih kopovarudnika uglja u Kolubarskom basenu. Izmereni srednji sadržaji koncentracija rastvornih,nerastvornih i ukupnih taložnih materija na godišnjem nivou prelaze 200 mg/m2dan (K-1, K-3, K-4, K-5). Distribucija čestica na svim lokacijama klasifikovana je na česticeveličine veće od 10 μm, zatim na čestice veličine od 10 μm do 2,5 μm i klase česticaveličine ispod 2,5 μm. Ovakva podela je dala odnos koncentracija inhalatornih irespiratornih čestica po mernim mestima. Skenirajuća elektronska mikroskopija jepokazala ...mineral, četica, prašina, leteći pepeo, aerosediment, PM10, teški metali,koncentracija, veličina čestice, Kolubara... 0% 20% 40% 60% 80% 100% K-1 K-2 K-3 K-4 K-5 K-6 K-7 K-8 K-9 K-10 K-11 K-12 F ( % ) 2,5 5 7,5 10 12,5 15 17,5 20 22,5 25 >25 Veličina čestica (µm) April 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% K-1 K-2 K-3 K-4 K-5 K-6 K-7 K-8 K-9 K-10 K-11 K-12 F ( % ) 2,5 5 7,5 10 12 ...
... 0% 20% 40% 60% 80% 100% K-1 K-2 K-3 K-4 K-5 K-6 K-7 K-8 K-9 K-10 K-11 K-12 F ( % ) 2,5 5 7,5 10 12,5 15 17,5 20 22,5 25 >25 Veličina čestica (µm) Jun 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% K-1 K-2 K-3 K-4 K-5 K-6 K-7 K-8 K-9 K-10 K-11 K-12 F ( % ) 2,5 5 7,5 10 12 ...
... (µm) Jul 0% 20% 40% 60% 80% 100% K-1 K-2 K-3 K-4 K-5 K-6 K-7 K-8 K-9 K-10 K-11 K-12 F ( % ) 2,5 5 7,5 10 12,5 15 17,5 20 22,5 25 >25 Veličina čestica (µm) Avgust 0% 20% 40% 60% 80% 100% K-1 K-2 K-3 K-4 K-5 K-6 K-7 K-8 K-9 K-10 K-11 K-12 F ( % ) 2,5 5 7,5 10 12,5 15 17,5 ...Željko R. Cvetković. "Mineralni i hemijski sastav čestica u atmosferi zone Kolubarskog basena i uticaj na životnu sredinu" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2013-11-18)
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Izvorišta i zahvati podzemnih voda
Dušan Polomčić (2021)Dušan Polomčić. Izvorišta i zahvati podzemnih voda, Beograd : Univerzitet u Beogradu, Rudarsko-geološki fakultet, 2021
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Productivity improvement with use of beam gas compressor: pilot test in Southeastern Europe mature field
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 optimisationBojan Martinović, Dušan Danilović, Branko Grubač, Robert Fadiga. "Productivity improvement with use of beam gas compressor: pilot test in Southeastern Europe mature field" in International Journal of Oil Gas and Coal Technology (2022)
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History of the development of the hydrodynamic model of the open pit mine “Drmno”, Serbia
With the creation of a hydrodynamic model, the need for it usually ceases until some next moment when the model needs to be updated and used for the set task for the necessary project documentation or dedicated studies. It is relatively rare that almost every year the model is improved and used for forecast calculations. The paper presents the basic characteristics and development of the hydrodynamic model of the open pit mine “Drmno” for 25 years. This open pit ...Dušan Polomčić, Jelena Ratković, Vesan Ristić Vakanjac. "History of the development of the hydrodynamic model of the open pit mine “Drmno”, Serbia" in National Conference with International Participation “GEOSCIENCES 2023”, Review of the Bulgarian Geological Society , Sofia : Bulgarian Geological Society (2023)
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On the distribution modulo 1 of the sum of powers of a Salem number
Dragan Stankov (2016)It is well known that the sequence of powers of a Salem number θ, modulo 1, is dense in the unit interval, but is not uniformly distributed. Generalizing a result of Dupain, we determine, explicitly, the repartition function of the sequence , where P is a polynomial with integer coefficients and θ is quartic. Also, we consider some examples to illustrate the method of determination.Algebraic integer, the house of algebraic integer, maximal modulus, reciprocal polynomial, primitive polynomial, Schinzel-Zassenhaus conjecture, Mahler measure, method of least squares, cyclotomic polynomialsDragan Stankov. "On the distribution modulo 1 of the sum of powers of a Salem number" in Comptes rendus Mathematique (2016). https://doi.org/10.1016/j.crma.2016.03.012
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Present Situation and Alternative Water Supply Solutions for Northern Vojvodina (Serbia)
The northern part of the Autonomous Province of Vojvodina is situated in the central and southeastern sectors of the Pannonian Basin. Drinking water supply is provided by groundwater abstraction from depths of 60 to 200 m. The quality of that water is poor, especially due to high concentrations of arsenic which most water supply systems do not remove. Current planning documents call for the construction of large regional water supply schemes on the banks of the Danube and Tisa ...Bojan Hajdin, Vesna Ristić-Vakanjac, Dušan Polomčić. "Present Situation and Alternative Water Supply Solutions for Northern Vojvodina (Serbia)" in Proceedings of Bulgarian Academy of Sciences, "Prof. Marin Drinov" Publishing House of Bulgarian Academy of Sciences (2020). https://doi.org/10.7546/CRABS.2020.04.09
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Numerical Modeling and Simulation of the Effectiveness of Groundwater Source Protection Management Plans: Riverbank Filtration Case Study in Serbia
The paper describes the establishment and testing of an algorithm for developing sustainable management plans associated with groundwater source protection against potential pollutants and discusses the effectiveness of individual systems. The applied methodology pertains to groundwater resource management, particularly those cases that involve riverbank filtration. Namely, groundwater (numerical) modeling is employed to examine the groundwater regime and balance, as well as to create protection systems and illustrate their effectiveness. Particle tracking analysis is used to study pollutants’ travel and ...Dušan Polomčić, Dragoljub Bajić, Bojan Hajdin, Dragan Pamučar. "Numerical Modeling and Simulation of the Effectiveness of Groundwater Source Protection Management Plans: Riverbank Filtration Case Study in Serbia" in Water, MDPI AG (2022). https://doi.org/10.3390/w14131993
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Estimating hydraulic parameters for the complex hydrodynamic models
Hydrodynamic models have usually been calibrated manually, by trial-and-error, with different values of hydraulic parameters and hydraulic characteristics of boundary conditions. This method of calibration and estimation of hydraulic parameters requires an extensive knowledge and experience of experts, but whether the resulting solution includes an optimal set of parameters still remains an open question. An optimization method founded upon the Gauss-Marquardt-Levenberg algorithm, along with PEST software based on that algorithm, introduces automation of model calibration with regularization, which substantially ...Dušan Polomčić, Dragoljub Bajić, Jelena Ratković, Bojan Hajdin. "Estimating hydraulic parameters for the complex hydrodynamic models" in Mining and Metallurgy Engineering Bor, Centre for Evaluation in Education and Science (CEON/CEES) (2018). https://doi.org/10.5937/mmeb1704029P
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Probabilistic analysis of anisotropic rock slope with reinforcement measures
During the construction of E75 highway through Grdelica gorge in Serbia, a major failure occurred in the zone of reinforced rock slope. Excavation was performed in highly anisotropic Paleozoic schist rock formation. The reinforcement consisted of the two rows of micropile wall with pre-stressed anchors. Forces in anchors were monitored with load cells while benchmarks were installed for superficial displacement measurements. The aim of the study is to investigate possible causes of instability considering different probability distributions of the ...Zoran Berisavljević, Dušan Berisavljević, Miloš Marjanović, Svetlana Melentijević. "Probabilistic analysis of anisotropic rock slope with reinforcement measures" in Geomechanics and Engineering (2023). https://doi.org/10.12989/gae.2023.34.3.285
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Application of the PROMETHEE and VIKOR methods for selecting the most suitable carbon dioxide geological storage option
CO2 storage in geological formations is one of the leading solutions for mitigation of greenhouse gas emissions. Types of geological formations that can be used for CO2 storage, that are discussed in this paper are: depleted oil and gas reservoirs, saline aquifers and injection CO2 in partially depleted oil reservoirs for enhanced oil recovery (EOR–CO2 method). In order to select the most suitable geological storage of CO2, the ranking of these storage options was performed using two methods of ...Lola Tomić, Vesna Karović Maričić, Dušan Danilović, Branko Leković, Miroslav Crnogorac. "Application of the PROMETHEE and VIKOR methods for selecting the most suitable carbon dioxide geological storage option" in Underground Mining Engineering, Belgrade : University Of Belgrade - Faculty of Mining and Geology (2019)
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Anthropogenic impact on the groundwater regime: Case study of the Velika Morava alluvium
Jovana Mladenović, Vesna Ristić Vakanjac, Milan Kresojević, Boris Vakanjac, Jugoslav Nikolić, Dušan Polomčić, Dragoljub Bajić (2023)The Velika Morava River originates at the junction of the Južna Morava and Zapadna Morava at the town of Stalać in Serbia. It is 185 km long and empties into the Danube. The Velika Morava River Basin occupies a land area of 37 444 km2. The river flows through central Serbia, which features the most fertile land and the highest population density in the country. Public water supply in this region of Serbia relies on groundwater formed in alluvial ...Jovana Mladenović, Vesna Ristić Vakanjac, Milan Kresojević, Boris Vakanjac, Jugoslav Nikolić, Dušan Polomčić, Dragoljub Bajić. "Anthropogenic impact on the groundwater regime: Case study of the Velika Morava alluvium" in National Conference with International Participation “GEOSCIENCES 2023”, Review of the Bulgarian Geological Society, Sofia : Bulgarian Geological Society (2023)
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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... periodu k moţe se reprezentovati skupom tehnologija eksploatacije (MTS): ( ) ( ), ( ) : ( ) , ( ) , ( ) moţe ostvariti ( ) .g lMTS k I k O k I k R O k R I k O k (4.1) gde je 1 2, ,...,k k k gI k i i i ulazni vektor tehnologije eksploatacije, a 1 2, ,...,k k k lO k ...
... 748 10 1 8,749 10 1 9,492 10 1 0,0027 k y k x k x k x k x k x k x k e x k x k x k x k 1 5 1 6 325 1 0,0517784 1 ; 0,1,2,3,4 x k x k k (5.1) AGO i IAGO ...
... 748 10 1 8,749 10 1 9,492 10 1 0,0027 k y k x k x k x k x k x k x k e x k x k x k x k 1 5 1 6 325 1 0,0517784 1 ; x k x k k=5+h; h=0,1,2,3,4 DOL-AGO 7,892 8,981 ...Svetlana M. Štrbac-Savić. "Prognoza operativne efikasnosti aktivnog podzemnog rudnika zasnovana na teoriji sivih sistema" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2016-06-10)
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Hydrodynamic analysis application of contaminated groundwater remediation to oil hydrocarbons
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, ...Predrag Pajić, Aleksandar Čalenić, Dušan Polomčić, Dragoljub Bajić. "Hydrodynamic analysis application of contaminated groundwater remediation to oil hydrocarbons" in Tehnika, Centre for Evaluation in Education and Science (CEON/CEES) (2018). https://doi.org/10.5937/tehnika1706825P
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Град Охрид и Извештај о одржаним међународним конференцијама “SDEWES” и “BALWOIS” на Охриду (Македонија)
Представљан је рад SDEWES и BALWOIS конференције које су одржане нa Охриду. Дат је увид у рад и развој ових конференција, као и утисака и искустава учесника, представника Департмана за хидрогеологију, Рударско-Геолошког факултета. Акценат је стављен на секцију која се бави одрживим развојем водних ресурса, уз прилог о самом Охриду због његовог геолошког и хидрогеолошког значаја и чињенице да је познати туристички центар, седиште бројних конгреса и конференција из области вода, управо због своје интересантне историје и природних ...Драгољуб Бајић, Јелена Зарић, Весна Ристић Вакањац, Душан Поломчић, Марина Чокорило Илић. "Град Охрид и Извештај о одржаним међународним конференцијама “SDEWES” и “BALWOIS” на Охриду (Македонија)" in Записници Српског Геолошког Друштва за 2013. годину, Српско геолошко друштво (2014)
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Simulation of groundwater regime and quantification of groundwater balance by means of hydrodynamic analysis: Case of open-cast mine 'Jakovačka Kumša'
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, ModflowDušan Polomčić, Dragoljub Bajić, Jelena Ratković, Đorđije Božović, Predrag Pajić. "Simulation of groundwater regime and quantification of groundwater balance by means of hydrodynamic analysis: Case of open-cast mine 'Jakovačka Kumša'" in Tehnika, Centre for Evaluation in Education and Science (CEON/CEES) (2019). https://doi.org/10.5937/tehnika1901056P
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Određivanje prostorne distribucije vrednosti hidrauličkih parametara izdani: primer površinskog kopa „Radljevo“
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, ...Dragoljub Bajić, Dušan Polomčić, Jelena Ratković, Predrag Pajić. "Određivanje prostorne distribucije vrednosti hidrauličkih parametara izdani: primer površinskog kopa „Radljevo“" in 9. Međunarodni simpozijum o upravljanju podzemnim resursima, Zaječar 2019., Megatrend Univerzitet, Fakultet za menadžment, Zaječar (2019)
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Hidrodinamički proračun zaštite površinskog kopa Drmno od podzemnih voda u periodu 2018-2022. godina
Površinski kop lignita Drmno nalazi se u blizini velikih reka (Dunav i Mlava), zbog čega eksploatacija otkrivke i lignita u velikoj meri zavisi od sistema zaštite od podzemnih voda. Ukoliko je sistem zaštite od podzemnih voda dobro isplaniran, a njegov kapacitet dobro proračunat, onda će se eksploatacija obavljati u suvoj sredini, što podrazumeva sigurnu proizvodnju otkrivke i lignita. U današnje vreme uz primenu adekvatnih softvera olakšano je kvalitetno planiranje i proračunavanje sistema za zaštitu površinskih kopova od podzemnih voda. ...Dušan Polomčić, Tomislav Šubaranović, Zoran Stojićević. "Hidrodinamički proračun zaštite površinskog kopa Drmno od podzemnih voda u periodu 2018-2022. godina" in Zbornik apstrakata sa 9. Međunarodne konferencije Ugalj, Zlatibor, 2019., Jugoslovenski komitet za površinsku eksploataciju (2019)
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The shear strength evaluation of rough and infilled joints and its indications for stability of rock cutting in schist rock mass
Construction of E75 highway section through Grdelica gorge was one of the most demanding projects realized in recent Serbian history. The alignment approximately 25 km long consists of several tens of bridges, two tunnels, three galleries and cuts with total length of 6 km. The alignment passes through highly anisotropic Palaeozoic schist rock formation of different weathering grades. This study focuses on shear strength properties of discontinuities, which are found to be the critical feature contributing to the occurrence ...Dušan Berisavljević, Zoran Berisavljević, Svetlana Melentijević. "The shear strength evaluation of rough and infilled joints and its indications for stability of rock cutting in schist rock mass" in Bulletin of engineering geology and the environment, Springer (2022). https://doi.org/10.1007/s10064-022-02580-8
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A contribution to the understanding of the discharge dynamics and water balance of the karst spring Gornji Dušnik (Suva Planina)
A sufficiently long time-series of daily discharges is needed to assess the discharge dynamics and calculate the water balance equation parameters of a spring (river source). The paper assumes that a catchment is gauged if a time-series of observations of at least 30 years is available, which is a rare case in Serbia. One-year monitoring is often set up to verify the reserves of a water source or spring intended for capture. Monitoring ceases after the final report is ...Aleksandar Tanasković, Vesna Ristić Vakanjac, Dušan Polomčić, Jelena Ratković. "A contribution to the understanding of the discharge dynamics and water balance of the karst spring Gornji Dušnik (Suva Planina)" in National Conference with International Participation “GEOSCIENCES 2023”, Review of the Bulgarian Geological Society, Sofia : Bulgarian Geological Society (2023)