Претрага
1092 items
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Hydrodynamic model of the open-pit mine “Buvač” (Republic of Srpska)
Polomčić Dušan, Bajić Dragoljub, Papić Petar, Stojković Jana. "Hydrodynamic model of the open-pit mine “Buvač” (Republic of Srpska)" in Journal of Sustainable Development of Energy, Water and Environment Systems (JSDEWES) 1 no. 3, Zagreb:SDEWES Centre (2013): 260-271
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Hydrodynamic analysis of potential groundwater extraction capacity increase: case study of Nelt groundwater source at Dobanovci
Bajić Dragoljub, Polomčić Dušan, Ratković Jelena, Matić Ivan. "Hydrodynamic analysis of potential groundwater extraction capacity increase: case study of Nelt groundwater source at Dobanovci" in Tehnika 4 no. 68, Belgrade:Union of Engineers and Technicians of Serbia (2017): 512-525. https://doi.org/10.5937/tehnika1704512B
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A hybrid model for forecasting groundwater levels based on fuzzy C-mean clustering and singular spectrum analysis
Polomčić Dušan, Gligorić Zoran, Bajić Dragoljub, Cvijović Čedomir. "A hybrid model for forecasting groundwater levels based on fuzzy C-mean clustering and singular spectrum analysis" in Water 7 no. 9, Basel:Multidisciplinary Digital Publishing Institute (2017): 541. https://doi.org/10.3390/w9070541
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Analysis of Blasting Impacts at the Open Pit Manastiriste near Topola on the Monastery Complex
Lutovac Suzana, Bajić Sanja, Gaćina Radmila, Urošević Katarina. "Analysis of Blasting Impacts at the Open Pit Manastiriste near Topola on the Monastery Complex" in Mining and Metallurgy Engineering Bor no. 2, Bor:Mining and Metallurgy Institute Bor (2016): 9-19. https://doi.org/10.5937/MMEB1602009B
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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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Razvoj rudarstva i metalurgije olova i cinka u rudniku ,,Trepča’’ – Stari Trg
Posle seobe Srba 1690. i 1735. godine, dolazi do prestanka eksploatacije rudnika na prostoru sadašnje Srbije i nakon zastoja od blizu 200 godina, aktivirana je rudarsko-metalurška delatnost u Srbiji u drugom kvartalu 20. veka. Prve koncesije otkupili su Englezi 1926. godine, zatim se aktiviraju rudnici u Starom Trgu (1927.), Kišnici (1927.), Ajvaliji (1930.), Novom Brdu (1933.), a u Zvečanu počinje da radi Flotacija (1930.) i Topionica sa Rafinerijom olova (1939.). U Kosovskoj Mitrovici počinje sa radom hemijska industruja 1961. ...Slobodan Trajković, Branislav Nikolić, Željko Kamberović, Sanja Bajić. "Razvoj rudarstva i metalurgije olova i cinka u rudniku ,,Trepča’’ – Stari Trg" in Bakar (2022). https://doi.org/10.5937/bakar2202011T
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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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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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Primena fuzzy optimizacije u hidrodinamičkoj analizi
znanje eksperta, optimizacija, trougaoni fuzzy brojevi, upravljanje podzemnim vodama, fuzzy logika, hidrodinamički modelDragoljub Bajić, Dušan Polomčić, Jelena Ratković, Predrag Pajić. "Primena fuzzy optimizacije u hidrodinamičkoj analizi" in XVII Kongres geologa Srbije (Zbornik radova XVII srpskog geološkog kongresa), Vrnjačka Banja, 17-20.05.2018., Srpsko geološko društvo (2018)
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Šematizacija hidrograma i nivograma radnog nivoa kod bunara sa horizontalnim drenovima
Dušan Polomčić, Dragoljub Bajić, Jelena Ratković, Đorđije Božović. "Šematizacija hidrograma i nivograma radnog nivoa kod bunara sa horizontalnim drenovima" in Proceedings of the XVI Serbian Symposium on Hydrogeology, Zlatibor, Serbia, 28. September - 02. October, 2022, University of Belgrade - Faculty of mining and geology (2022)
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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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Hydrodynamic analysis of radial collector well ageing at Belgrade well field
The origin and effect of hydraulic resistances on the rate of ageing of radial collector wells are identified through numerical hydrodynamic analysis. The research includes hydrodynamic modeling of one such well with new laterals at Belgrade well field. The performance of the laterals is aggravated by rapid ageing. The change in the hydraulic parameters of the laterals during the first decade of operation is analyzed through simulations of the groundwater regime with realistically specified geometries and hydraulics of the ...Đorđije Božović, Dušan Polomčić, Dragoljub Bajić, Jelena Ratković. "Hydrodynamic analysis of radial collector well ageing at Belgrade well field" in Journal of Hydrology, Elsevier BV (2019). https://doi.org/10.1016/j.jhydrol.2019.124463
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Imputing missing data using grey system theory and the biplot method to forecast groundwater levels and yields
Groundwater management is one of today’s important tasks. It has become necessary to seek out increasingly reliable methods to conserve groundwater resources. Dependable forecasting of the amounts of groundwater that can be abstracted in a sustainable manner requires longterm monitoring of the groundwater regime (rate of abstraction and groundwater levels). Monitoring of the groundwater source for the town of Bečej, Serbia had been disrupted for multiple years. The objective of the paper is to assess the possibility of reinterpreting ...Jelena Ratković, Dušan Polomčić, Zoran Gligorić, Dragoljub Bajić. "Imputing missing data using grey system theory and the biplot method to forecast groundwater levels and yields" in Geologia Croatica, Hrvatski geološki institut (2022). https://doi.org/10.4154/gc.2022.14
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Primena hidrodinamičkog modeliranja u rešavanju problema zaštite građevinskih objekata od podzemnih voda na primeru višenamenske sportske hale u Inđiji
Pregrad Pajić, Uroš Urošević, Dušan Polomčić, Dragoljub Bajić . "Primena hidrodinamičkog modeliranja u rešavanju problema zaštite građevinskih objekata od podzemnih voda na primeru višenamenske sportske hale u Inđiji" in Proceedings of the XVI Serbian Symposium on Hydrogeology, Zlatibor, Serbia, 28. September - 02. October, 2022, University of Belgrade - Faculty of mining and geology (2022)
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Application of the autoregressive model, grey model and biplot method to groundwater sources
Jelena Ratković, Dušan Polomčić, Zoran Gligorić, Dragoljub Bajić. "Application of the autoregressive model, grey model and biplot method to groundwater sources" in Proceedings of the XVIII Serbian Geological Congress, Divčibare, Serbia, 01-04 June 2022, Serbian Geological Society (2022)
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Ostvarivanje dobiti pri uvođenju sistema agregatnih zamena na osnovnoj rudarskoj mehanizaciji površinskih kopova EPS
Jedan od osnovnih zadataka na površinskim kopovima uglja je ostvarivanje zadovoljavajućeg vremenskog i kapacitetnog iskorišćenja kontinualnih sistema. Da bi se to postiglo, neophodno je izvršiti izmene u postojećoj strategiji održavanja. Preduslov je uvođenje agregatne zamene vitalnih delova na rudarskim mašinama. Benefiti su višestruki. Očekivani rezultati ovakvog pristupa su: smanjenje zastoja i povećanje vremena rada; direktne materijalne uštede; bolja organizacija rada; racionalizaciju radioničkih i magacinskih kapaciteta; povećanje vrednosti mašina. Da bi se uvela agregatna zamena neophodne su investicije za nabavku ...Predrag Jovančić, Ignjatović Dragan, Đenadić Stevan. "Ostvarivanje dobiti pri uvođenju sistema agregatnih zamena na osnovnoj rudarskoj mehanizaciji površinskih kopova EPS" in X Međunarodna konferencija UGALJ, Zlatibor, Srbija, 13-16. Oktobar 2021., Jugoslovenski komitet za površinsku eksploataciju (2021)
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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 ...Aleksandar Mijatović, Biljana Šmit, Ana Rilak, Biljana Petrović, Dragan Čanović, Živadin D. Bugarčić. "NMR kinetic studies of the interactions between [Ru(terpy)(bipy)(H2O)]2+ and some sulfur-donor ligands" in Inorganica Chimica Acta, Elsevier BV (2012). https://doi.org/10.1016/j.ica.2012.09.016
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Tectonic evolution of the Circum-Moesian orocline of the Carpatho-Balkanides: Paleomagnetic constraints
Emő Márton, Vesna Cvetkov, Miodrag Banješević, Gábor Imre, Aleksandar Pačevski. "Tectonic evolution of the Circum-Moesian orocline of the Carpatho-Balkanides: Paleomagnetic constraints" in Journal of Geodynamics, Elsevier BV (2024). https://doi.org/10.1016/j.jog.2024.102058
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The number of unimodular roots of some reciprocal polynomials
Dragan Stankov (2020)We introduce a sequence P2n of monic reciprocal polynomials with integer coefficients having the central coefficients fixed. We prove that the ratio between number of nonunimodular roots of P2n and its degree d has a limit when d tends to infinity. We present an algorithm for calculation the limit and a numerical method for its approximation. If P2n is the sum of a fixed number of monomials we determine the central coefficients such that the ratio has the minimal limit. ...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. "The number of unimodular roots of some reciprocal polynomials" in Cmptes rendus mathematique (2020). https://doi.org/10.5802/crmath.28
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Nelinearno dinamičko modelovanje potresa izazvanih promenom naponskog stanja pri izradi horizontalnih podzemnih prostorija
Srđan D. Kostić (2013-11-04)U ovoj disertaciji, cilj istraživanja bio je određivanje dinamičkih svojstava potresaizazvanih promenom naponskog stanja pri izradi horizontalnih podzemnih prostorija.Analiza potresa izvedena je sa dva aspekta – u prvom delu istraživanja izučavane suvremenske serije oscilovanja tla za vreme potresa, a u drugom delu vršena je analizastabilnosti fenomenološkog Baridž-Knopof modela bloka sa oprugom. Vremenske serijeoscilovanja tla proučavane su primenom postupka analize surogat podataka, kao ikorišćenjem metoda analize nelinearnih vremenskih serija (primena teoreme orazvijanju skalarne vremenske serije). Analiza vremenskih serija izvedena je ...potres, naponsko stanje, podzemne prostorije, bifurkacije, vremenskaserija, deterministički haos, stohastičnost, perturbacije, vremensko kašnjenje, jačina trenja... y(k)=[s(k), s(k+τ),…,s(k+(d-1)τ)] ima najbliži vektor yNN (k), pri čemu se pod blizinom podrazumeva neka funkcija rastojanja, poput Euklidskog rastojanja, koje se može izraziti na sledeći način: 2 22 2 ( ) ( ) ( ) ( ) ( ) ... ... ( ( 1)) ( ( 1)) NN NN d NN R k s k s k s k s k s k d ...
... bloka Vb=0,01-10m/s i pri stalnoj brzini celog sistema (VL=30mm/god.≈3x10-9m/s). Na slici 1-3a jasno se uočava početni period ,,stagniranja’’ u porastu čvrstoće na smicanje. Za Vb=VL=1μm/s, statička čvrstoća se linearno povećava sa logt. Međutim, za Vb=1m/s, i VL=10-9m/s efektivna brzina reg ...
... vremenske serije, s(n), neka početna vremenska serija s(n) predstavlja skup A, a rezultati merenja u vremenskom trenutku t+τ, s(n+τ) – skup B. Prosečna uzajmna informacija između osmatranja u trenutku n i n+τ, odnosno prosečna količina informacija o s(n+τ) na osnovu osmatranja s(n) može se izraziti ...Srđan D. Kostić. "Nelinearno dinamičko modelovanje potresa izazvanih promenom naponskog stanja pri izradi horizontalnih podzemnih prostorija" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2013-11-04)