Претрага
2829 items
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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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Petrological and geochemical studies of lignite from the Tamnava West field, Kolubara basin (Serbia)
Milena Pajić, Reinhard F. Sachsenhofer, Achim Bechtel, Ksenija Stojanović, Vladimir Krstić, Dragana Životić (2021)... are the main constituents of saturated fractions with variable amount of m- alkanes and hopanoids. Content of sesquiterpenoids, triterpenoids and steroids in saturated fracttons is low. Aromatic fraction ıs characterised by high content of triterpenoids with variable amount of diterpenoids. The 16a( ...
... fraction. Maceral composition and distribution of biomarkers of lignite from Tamnava West field imdicate high contribution of gymnosperm with variable contributioh of angiosperms in КЕ > РГ ia KOD precursor OM. Significant aromatisation of triterpenoids during diagenesis with microbial ...
... радовима запослених доступним у слободном приступу. - Претрага репозиторијума доступна је на www.dr.rgf.bg.ac.rs The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository ...Milena Pajić, Reinhard F. Sachsenhofer, Achim Bechtel, Ksenija Stojanović, Vladimir Krstić, Dragana Životić. "Petrological and geochemical studies of lignite from the Tamnava West field, Kolubara basin (Serbia)" in 72nd Annual Meeting of the International Commitee for Coal and Organic Petrology (ICCP), The Prague, Chech Republic, 19th – 25 th September, ICCP (2021)
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Linearization of Input Signal as a Necessary Tool in Stochastic Modeling of Karst Groundwater
Veljko Marinović (2021)Modelling of karst hydrogeological systems is a very complicated task, bearing in mind that for a deterministic model one should know the internal physical processes of precipitation transformation into discharge, while for a stochastic model nonlinear dynamic systems such as karst should be simulated by linear regression equations. Stochastic models need linearization of input time series due to often large residual in the recession period. This occur because the model is not able to absorb single rain episodes, which ...Veljko Marinović. "Linearization of Input Signal as a Necessary Tool in Stochastic Modeling of Karst Groundwater" in Karst: From Top to Bottom, Belgrade, 6.6.2021., Belgrade : Centre for Karst Hydrogeology (2021)
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Distribution of Potentially Toxic Elements in the City of Zintan and Its Surroundings (Northwestern Libya) by Surface Soil Sampling
Boris Vakanjac, Zorana Naunović, Vesna Ristić Vakanjac, Tanita Đumić, Saša Bakrač, Jana Štrbački, Vuk Gajić, Taher Mohamed Alzarog (2023)The study area is the city of Zintan, in northwestern Libya, which has grown over the past 30 years. Its current population is roughly 30,000. Although the city is in part commercial, most of the population engages in agriculture and primarily grows cereal crops (wheat and barley). The demand of the growing city for agricultural products has increased, intensifying the use of fertilizers, pesticides, and insecticides. Consequently, concentrations of potentially toxic elements (PTE) in the soil have increased. To ...Boris Vakanjac, Zorana Naunović, Vesna Ristić Vakanjac, Tanita Đumić, Saša Bakrač, Jana Štrbački, Vuk Gajić, Taher Mohamed Alzarog. "Distribution of Potentially Toxic Elements in the City of Zintan and Its Surroundings (Northwestern Libya) by Surface Soil Sampling" in Minerals, MDPI AG (2023). https://doi.org/10.3390/min13081048
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Mean-based iterative methods for finding multiple roots in nonlinear chemistry problems
Dejan Ćebić, Nebojša M. Ralević (2021)Dejan Ćebić, Nebojša M. Ralević. "Mean-based iterative methods for finding multiple roots in nonlinear chemistry problems" in Journal of Mathematical Chemistry, Springer Science and Business Media LLC (2021). https://doi.org/10.1007/s10910-021-01253-3
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Hidrološki i hidraulički mehanizam isticanja vrela Rijeka Crnojevića
Rijeka Crnojevića predstavlja karstno (kraško) vrelo, koje u teritоrijalnom pogledu pripada Opštini Cetinje, u gеоlоškо-tеktоnskоm pоglеdu pripаdа zоni Visоkоg kršа (оblаst stаrе Crnе Gоrе), dоk prema hidrogeološkoj rejonizaciji spаdа u prоstоr Spoljašnjih Dinarida. Izvire iz Obodske (ili Crnojevića) pećine u selu Obod (81 m.n.m.). Voda koja ističe iz Obodske pećine vodi porijeklo od atmosferskih voda, koje se formiraju na prostoru Cetinjskog polja i Dobrskog sela. Vоdе nа оbоdu pоljа pоniru i kreću se uglаvnоm podzemnim kаvеrnаmа i kаnаlimа, nаstаlim ...Golub Ćulafić, Veljko Marinović, Branislav Petrović, Jelena Krstajić. "Hidrološki i hidraulički mehanizam isticanja vrela Rijeka Crnojevića" in KRAS - VEKOVNA NAUČNA INSPIRACIJA, naučni skup posvećen dr Dušanu Gavriloviću profesoru Geografskog fakulteta, Univerzitet u Beogradu - Geografski fakultet (2022)
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Дефинисање механичких својстава алтерисаног стенског материјала лабораторијским методама
Вељко М. Рупар (2022)Основни циљ овог рада је да представи методологију одређивања механичких својстава хетерогеног стенског масива који изграђују дацит (Д) и алтерисани дацит (АД), где је уочена је зона постепеног преласка од алтерисаног дацита до дацита. Механичка својства стенског масива у тој зони утврђена су на основу лабораторијских испитивања једноосне и троосне чврстоће на притисак стенског материјала композитних узорака. Композитни узорци су се састојали од дискова стенског материјала, при чему је висина дискова h дефинисала различити процентуални удео појединог стенског материјала, ...дацит, алтерисани дацит, једноосна чврстоћа на притисак, троосна чврстоћа на притисак, композитни узорци, механика стена, стабилност косинаВељко М. Рупар. Дефинисање механичких својстава алтерисаног стенског материјала лабораторијским методама, Београд : [В. Рупар], 2022
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Security of Supply as a Major Part of the Energy Security Puzzle
Sigurnost snadbevanja prirodnim gasom Republike Srbije se kroz poslednje dve decenije tretira kao hitno, strateško, političko i bezbednosno pitanje. U sektoru prirodnog gasa, Republika Srbija je veoma zavisna od gasa koji uvozi iz Rusije. Indikatori sigurnosti snadbevanja predstavljaju jedan od osnovnih elemenata za određivanje energetske bezbednosti i snažne alate za usmeravanje energetskog sektora ka održivom razvoju. Metodolaška analiza prikazana u radu je bila koncentrisana na pokazatelje sigurnosti snadbevanja u oblasti energetske bezbednosti koji se odnose na sektor prirodnog gasa ...energetska bezbednost, sigurnost snabdevanja, energetski indikator, dostupnost energije, diversifikacija izvora i pravacaAleksandar Madžarević, Miroslav Crnogorac. "Security of Supply as a Major Part of the Energy Security Puzzle" in Energija, ekonomija, ekologija, University Library in Kragujevac (2022). https://doi.org/10.46793/EEE22-4.28M
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The Flow Conditions in the Epikarst Zone of a Karst Aquifer. Case Study: Suva planina Mt., East Serbia
Branislav Petrović (2022)The epikarst as a part of the karst aquifer represents a complex point of contact and mixing of unconsolidated material from the terrain surface, carbonate rocks altered by “corrosive” water, flora and fauna (and remains of), which is partially saturated with groundwater. Recharge of karst aquifers, usually, occurs via the unsaturated zone which uppermost part could be epikarst zone. Significant amounts of (plant accessible) water, and other solutes and particles, can be stored in this zone for extended periods ...Branislav Petrović. "The Flow Conditions in the Epikarst Zone of a Karst Aquifer. Case Study: Suva planina Mt., East Serbia" in International Scientific Conference - Man and Karst 2022, Custonaci, Italy, 12-16.09.2022, Gruppo Grotte Ragusa - C.I.R.S. (2022)
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Part of Speech Tagging for Serbian language using Natural Language Toolkit
Ranka Stanković, Boro Milovanović (2020)Dok se razvijaju složeni algoritmi za NLP (obrada prirodnog jezika), osnovni zadaci kao što je označavanje ostaju veoma važni i još uvek izazovni. NLTK (Natural Language Toolkit) je moćna Python biblioteka za razvoj programa zasnovanih na NLP-u. Pokušavamo da iskoristimo ovu biblioteku za kreiranje PoS (vrsta reči) oznake za savremeni srpski jezik. Jedanaest različitih modela je kreirano korišćenjem NLTK API-ja za označavanje. Najbolji modeli se transformišu sa Brill tagerom da bi se poboljšala tačnost. Obučili smo modele na označenom ...... basic task is PoS (Part of Speech) tagging, a process of assigning a part of speech category to each token in the text. The program that performs tagging is called tagger. The taggers can be created in multiple ways. In this paper, we will create a tagger for Serbian with a help of a Python library NLTK ...
... радовима запослених доступним у слободном приступу. - Претрага репозиторијума доступна је на www.dr.rgf.bg.ac.rs The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository ...
... test set of 20,000 tokens were demonstrated with the Perceptron tagger: 92,52 – 95,76% accuracy for the different tagsets. Index Terms—Natural Language Processing; Machine Learning; Neural Network. I. INTRODUCTION In the last couple of years, a big advancement in the field of Natural ...Ranka Stanković, Boro Milovanović. "Part of Speech Tagging for Serbian language using Natural Language Toolkit" in 7th International Conference on Electrical, Electronic and Computing Engineering IcETRAN 2020, Academic Mind, Belgrade (2020)
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Simulation of the operating regime and determination of the radius of influence of the groundwater sources „Parmenac“ and „Beljina“ (Čačak)
Polomčić Dušan, Bajić Dragoljub, Močević Jelena, Špadijer Slavko, Drašković Dejan. "Simulation of the operating regime and determination of the radius of influence of the groundwater sources „Parmenac“ and „Beljina“ (Čačak)" in Proceedings of the XV Serbian Symposium on Hydrogeology, Belgrade:University of Belgrade - Faculty of mining and geology (2016): 141-146
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Polymorphism and photoluminescence properties of K3ErSi2O7
alkalni silikati elemenata retkih zemalja, silikati lantanoida, polimorfizam, fotoluminescencija, kristalna strukturaPredrag Dabić, Marko G. Nikolić, Sabina Kovač, Aleksandar Kremenović. "Polymorphism and photoluminescence properties of K3ErSi2O7" in Acta Crystallographica Section C Structural Chemistry, International Union of Crystallography (IUCr) (2019). https://doi.org/10.1107/S2053229619011926
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Tectonothermal evolution of an asymmetric extensional system: the Juhor Mts in Central Serbia (Northern Serbomacedonian massif)
Miloš Radonjić, Uroš Stojadinović, Elco Luijendijk, Dejan Radivojević, Željko Golubović, Nikola Vuković (2018)... setting of the Pannonian Basin argue for the internal deformation of principal tectonic units constituting the basement of the basin, rather than motion along the boundaries of large‐scale fully rigid blocks (Bada et al., 2007). The Juhor Mts in central Serbia represent an inselberg of Proterozo ...
... радовима запослених доступним у слободном приступу. - Претрага репозиторијума доступна је на www.dr.rgf.bg.ac.rs The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository ...
... TECTONOTHERMAL EVOLUTION OF AN ASYMMETRIC EXTENSIONAL SYSTEM: THE JUHOR MTS IN CENTRAL SERBIA (NORTHERN SERBOMACEDONIAN MASSIF) Miloš Radonjić1, Uroš Stojadinović1, Elco Luijendijk2, Dejan Radivojević1, Željko Golubović3, Nikola Vuković4 1) University of Belgrade, Faculty of Mining and Geology ...Miloš Radonjić, Uroš Stojadinović, Elco Luijendijk, Dejan Radivojević, Željko Golubović, Nikola Vuković. "Tectonothermal evolution of an asymmetric extensional system: the Juhor Mts in Central Serbia (Northern Serbomacedonian massif)" in 17th Serbian Geological Congress, Vrnjačka Banja, 17-20 maj 2018, Srpsko geološko društvo (2018)
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The Flow Conditions in the Epikarst Zone of a Karst Aquifer. Case Study: Suva planina Mt., East Serbia
Branislav Petrović (2023)The epikarst as a part of the karst aquifer represents a complex point of contact and mixing of unconsolidated material from the terrain surface, carbonate rocks altered by “corrosive” water, flora and fauna (and remains of), which is partially saturated with groundwater. Significant amounts of (plant accessible) water, and other solutes and particles, can be stored in this zone for extended periods of time. Thus, attenuation or biochemical processes could start in this layer and change quality of infiltrated ...Branislav Petrović. "The Flow Conditions in the Epikarst Zone of a Karst Aquifer. Case Study: Suva planina Mt., East Serbia" in International Scientific Conference "Man and Karst 2022", CIRS - Centro Ibleo di Ricerche Speleo-Idrogeologiche (2023)
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Fluid inclusion systematics in the Okoška gora polymetallic deposit
... радовима запослених доступним у слободном приступу. - Претрага репозиторијума доступна је на www.dr.rgf.bg.ac.rs The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository ...
... part of the Austroalpine imbricated stack (Schmidetal., 2020 and referencestherein). The metasedimentary sequence consists of micaschist, gnciss, marble and quartzite, which underwent amphibolite grade metamorphism during the Cretaceous. The Pohorje series was emplaced by several episodes of magmatic ...
... polarised light of the optical microscope. On the thin-section level, the two quartz not appčarto cross-cut, but at the outcrop scale veins of transparentquartz intersectvi amethyst (Janez Žavašnik, verbal comm.), suggesting the later's earlier paragenetic p Fluid inclusion systematics A total of 100 fluid ...Aleš Šoster, Miloš Velojić, Barbara Potočnik Krajnc, Matej Dolenec. "Fluid inclusion systematics in the Okoška gora polymetallic deposit" in 25th meeting of Slovenian geologists, Ljubljana, 2021, Univerza v Ljubljani, Oddelek za geologijo (2021)
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Analiza nosivosti vertikalno opterećenog šipa za potrebe izgradnje petlje „Merošina 1“ na autoputu E-80 deonica: Niš – Merošina
U Srbiji je počela izgradnja autoputa E-80 koji će predstavljati saobraćajno čvorište zapadnog Balkana i biće deo glavne regionalne transportne mreže jugoistočne Evrope. Njegova ukupna dužina kroz Srbiju iznosi 77 km, a prva deonica u dužini od 5.5 km je završena i puštena u saobraćaj krajem jula 2023. god. To je prva od četiri deonice Sektora 1 čija je dužina 32.65 km. U sklopu petlje „Merošina 1“ izgrađen je nadvožnjak koji je oslonjen na devet stubnih mesta na međusobnom ...Dragoslav Rakić, Nikola Božović, Miloš Stevanović, Milan Bogdanović. "Analiza nosivosti vertikalno opterećenog šipa za potrebe izgradnje petlje „Merošina 1“ na autoputu E-80 deonica: Niš – Merošina" in Geotehnički aspekti građevinarstva i zemljotresno inženjerstvo – Vrnjačka Banja, 01-03. novembar 2023., Beograd : Savez građevinskih inženjere Srbije (2023)
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Manganese-pyromellitate complex as a precursor for preparation of spinel Mn3O4
Lidija Radovanović, Željko Radovanović, Aleksandar Kremenović, Bojana Simović, Milica V. Vasić, Jelena Rogan (2022)In recent years, thermal decomposition studies of transition metal complexes with benzenepolycarboxylate ligands have become an area of a great importance due to the possibility of obtaining useful metal oxides with desirable electrical, magnetic and catalytic properties [1]. As a contrast to conventional methods for the preparation of metal oxides, such as hydrothermal or sol–gel treatment, thermolysis is faster, more efficient ...Lidija Radovanović, Željko Radovanović, Aleksandar Kremenović, Bojana Simović, Milica V. Vasić, Jelena Rogan. "Manganese-pyromellitate complex as a precursor for preparation of spinel Mn3O4 " in XIV Conference of chemists, technologists and environmentalists of Republic of Srpska, Academy of sciences and arts of the Republic of Srpska, Banja Luka, Republic of Srpska, B&H, October 21st-22nd, 2022, University in Banjaluka, Faculty of Technology (2022)
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The number of nonunimodular roots of a reciprocal polynomial
Dragan Stankov (2023)We introduce a sequence Pd of monic reciprocal polynomials with integer coefficients having the central coefficients fixed as well as the peripheral coefficients. We prove that the ratio of the number of nonunimodular roots of Pd to its degree d has a limit L when d tends to infinity. We show that if the coefficients of a polynomial can be arbitrarily large in modulus then L can be arbitrarily close to 0. It seems reasonable to believe that if ...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 nonunimodular roots of a reciprocal polynomial" in Comptes rendus mathematique, Elsevier France Editions Scientifiques et Medicales (2023). https://doi.org/10.5802/crmath.422
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The Newton method for solving nonlinear equations based on aggregation operators
Nebojša M. Ralević, Dejan Ćebić (2019)Nebojša M. Ralević, Dejan Ćebić. "The Newton method for solving nonlinear equations based on aggregation operators" in XLVI International Symposium on Operational Research SYM-OP-IS, Kladovo, 15-18.9.2019, Универзитет у Београду (2019)
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Negative Impact of Backwater Levels of Danube River and its Tributaries to the Groundwater Regime in Meliorated Riverside Areas
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 engagementPredrag Pajić, Uroš Urošević, Dušan Polomčić, Milan Dimkić. "Negative Impact of Backwater Levels of Danube River and its Tributaries to the Groundwater Regime in Meliorated Riverside Areas" in IWA Specialist Groundwater Conference, Conference Proceedings and Book of Abstracts, 09-11 June 2016, Belgrade, Serbia, Institut Jaroslav Černi (2016)