Претрага
1482 items
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Convective heat transfer in centrifugal pumps lifted wells: the case of South-Eastern Europe waxy wells
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 ...Bojan Martinovic, Marija Živković, Branko Grubač. "Convective heat transfer in centrifugal pumps lifted wells: the case of South-Eastern Europe waxy wells" in International Journal of Oil, Gas and Coal Technology, Inderscience Publishers (2021). https://doi.org/10.1504/IJOGCT.2021.10043281
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Filter rules for soil and geosynthetics
Štetni efekti izazvani strujanjem vode kroz različite građevine (brane, nasipi i sl.) uspešno se rešavaju ugradnjom različitih filterskih slojeva. Osnovne funkcije filterskih slojeva su brza evakuacija vode uz sprečavanje unutrašnje erozije i iznošenje sitnih čestica tla. Ovi filterski slojevi najčešće se grade od krupnozrnih materijala (pesak, šljunak, kameni agregati), ali se pored prirodnih materijala sve više koriste i veštački geosintetički materijali. U radu su prikazana osnovna filtarska pravila koja treba ispoštovati da bi se izvelo uspešno projektovanje različitih filtracionih ...Dragoslav Rakic, Irena Basaric Ikodinovic, Milenko Ljubojev. "Filter rules for soil and geosynthetics" in Mining and Metallurgy Engineering Bor, Mining and Metallurgy Institute Bor (2021). https://doi.org/10.5937/mmeb2101001R
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Sexual dimorphism and left-right asymmetry of carapace ornamentation in Hemicytheria setosa RUNDIĆ 2002
In biostratigraphic research of the Upper Miocene of the Pannonian Basin System, one of the frequently detected and important ostracod genera is Hemicytheria. Among more than 20 species of this genus, Hemicytheria setosa is present in sandy facies of the Lake Pannon sediments in Serbia and Bosnia and Herzegovina. The aims of this study were to describe sexual dimorphism and differences between left and right valve morphology in Hemicytheria setosa. Landmark based geometric morphometrics is applied on the grounds ...Morfologija ljušture, Ostrakode, geometrijska morfometrija, gornji miocen, južni deo Panonskog basenaVukica Vujić, Ljupko Rundić, Tamara Karan-Žnidaršič. "Sexual dimorphism and left-right asymmetry of carapace ornamentation in Hemicytheria setosa RUNDIĆ 2002" in Geologia Croatica, Croatian Geological Survey (2019). https://doi.org/10.4154/gc.2019.07
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DNA/BSA interactions and cytotoxic studies of tetradentate N,N,O,O Schiff base copper(II) complexes
Aleksandar Mijatović, Angelina Caković, Aleksandar Lolić, Snezana Sretenović, Marko Živanović, Dragana Seklić, Jovana Bogojeski, Biljana Petrović (2023)Three Schiff base Cu(II) complexes, (N,N’-bis(acetylacetone)propylenediimine)copper(II) complex, [Cu(acac2pn)] (1), (N,N'-bis-(benzoylacetone)propylenediimine)copper(II) complex, [Cu(phacac2pn)] (2) and (N,N’-bis-(trifluoroacetylacetone)propylenediimine)copper(II) complex, [Cu(tfacac2pn)] (3), were used to investigate the interactions with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA) using the electronic absorption and spectroscopic fluorescence methods. UV-Vis absorption studies showed that studied complexes interact with DNA molecule and exhibit moderate binding affinity. Fluorescence studies of complexes 1-3 also showed a possibility for DNA intercalation as well as a relatively high binding ability ...Aleksandar Mijatović, Angelina Caković, Aleksandar Lolić, Snezana Sretenović, Marko Živanović, Dragana Seklić, Jovana Bogojeski, Biljana Petrović. "DNA/BSA interactions and cytotoxic studies of tetradentate N,N,O,O Schiff base copper(II) complexes" in Journal of the Serbian Chemical Society (2023). https://doi.org/10.2298/JSC230614063M
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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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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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Towards resolving Cretaceous to Miocene kinematics of the Adria-Europe contact zone in reconstructions: Inferences from a structural study in a critical Dinarides area
One key element in the current debate analysing the Central Mediterranean evolution is the Cretaceous structure and kinematics of the present-day oroclinal bent contact between Adria-and Europe-derived continental units in the Dinarides, interpreted in different tectonic reconstructions as a subduction-related thrust system or a large-scale strike-slip fault zone. We provide a solution to the debate by a structural and kinematic study in a key area located in central Serbia along the Europe–Adria orogenic suture of the Sava Zone. The ...Uroš Stojadinović, Nemanja Krstekanić, Liviu Matenco, Tamara Bogdanović. "Towards resolving Cretaceous to Miocene kinematics of the Adria-Europe contact zone in reconstructions: Inferences from a structural study in a critical Dinarides area" in Terra Nova, Wiley (2022). https://doi.org/10.1111/ter.12618
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Serbian ELTeC Sub-Collection in Wikidata
This paper presents an example of integration of Wikidata with digital libraries and external systems, as well as some best practices for speeding up the process of data preparation and import to Wikidata, on the use case of SrpELTeC, Serbian subcollection of the ELTeC multilingual collection (European Literary Text Collection). After preliminary work on the manual Wikidata population with SrpELTeC novels, the goal was to automate the process of preparing and importing information, so different solutions were analysed and ...Milica Ikonić Nešić, Ranka Stanković, Biljana Rujević. "Serbian ELTeC Sub-Collection in Wikidata" in Infotheca, Faculty of Philology, University of Belgrade (2021). https://doi.org/10.18485/infotheca.2021.21.2.4
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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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Assessment of river sediment quality according to the eu water framework directive in large river fluvial conditions. A case study in the lower Danube river basin
Atanas Hikov, Anca-Marina Vîjdea, Irena Peytcheva, Gyozo Jordan, Prvoslav Marjanović, Zlatka Milakovska, Petyo Filipov, Milena Vetseva, Albert Baltres, Veronica Elena Alexe, Lidia-Lenuța Bălan, Marko Marjanović, Vladica Cvetković, Kristina Šarić & The Simona Project Team (2023)Monitoring, uzorkovanje, hazardne supstance, teški metali, organske supstance, geološka osnova, standard kvaliteta životne sredine (EQS), basen reke DunavAtanas Hikov, Anca-Marina Vîjdea, Irena Peytcheva, Gyozo Jordan, Prvoslav Marjanović, Zlatka Milakovska, Petyo Filipov, Milena Vetseva, Albert Baltres, Veronica Elena Alexe, Lidia-Lenuța Bălan, Marko Marjanović, Vladica Cvetković, Kristina Šarić & The Simona Project Team. "Assessment of river sediment quality according to the eu water framework directive in large river fluvial conditions. A case study in the lower Danube river basin" in Carpathian Journal of Earth and Environmental Sciences (2023). https://doi.org/10.26471/cjees/2023/018/251
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Environmental Noise Impact Assessment for Large-Scale Surface Mining Operations in Serbia
Noise emissions are a significant environmental impact caused by the mining industry in all technological phases of surface mining, mineral processing, and waste disposal. This paper presents the role of noise impact assessment and control in large-scale surface mining operations. Mine planning develops the model of mining operations, ore excavation, and waste dumping scheduling and processing rates, including spatial distribution of mining activities. Such a level of mine planning requires an environmental impact assessment study. This can be achieved ...Uros Pantelic, Petar Lilic, Aleksandar Cvjetic, Nikola Lilic. "Environmental Noise Impact Assessment for Large-Scale Surface Mining Operations in Serbia" in Sustainability, MDPI AG (2023). https://doi.org/10.3390/su15031798
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Веб-алат за управљање грађом Речника САНУ и анотација листића
Грађа на основу које се израђује Речник српскохрватског књижевног и народног језика САНУ, а која садржи материјал из преко 4.500 писаних извора и 300 рукописних збирки речи са подручја народних говора штокавског наречја, забележена је на око 5.000.000 листића. Богат лексички материјал, који обухвата књижевни и народни језик у протекла два века и на основу кога треба да се напише још најмање 15 томова Речника, пружа могућност и за разноврсна лингвистичка и ванлингвистичка истраживања. Из тог разлога се приступило ...Рада Стијовић, Ранка Станковић, Михаило Шкорић. "Веб-алат за управљање грађом Речника САНУ и анотација листића" in Rasprave Instituta za hrvatski jezik i jezikoslovlje, Institute of Croatian Language and Linguistics (2020). https://doi.org/10.31724/rihjj.46.2.32
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Interaction of sodium dodecylsulfate (SDS) with homoionic montmorillonites: adsorption isotherms and metal-ion release
The interaction of dodecylsulfate anions (DS−) with homoionic Ca-, Mg-, Ni-, Cu-, Cd-, Pb- and Fe-montmorillonites were investigated. Mg- and Cd-montmorillonite do not adsorb DS−, and an anion exchange at the edges of the clay mineral does not take place. Three different adsorption processes are identified on the other montmorillonites: i) Fe-montmorillonite is covered with amorphous iron hydroxide, and DS−-anions are bound at positively charged sites. ii) On Ca- and Pb-montmorillonite DS− is precipitated as Me(DS)2. iii) On Ni- ...M. Ilic, J. Gonzalez, A. Pohlmeier, H. D. Narres, M. J. Schwuger. "Interaction of sodium dodecylsulfate (SDS) with homoionic montmorillonites: adsorption isotherms and metal-ion release" in Colloid Polymer Science, Springer Science and Business Media LLC (1996). https://doi.org/10.1007/BF00656626
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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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Influence of mono- and two-component organic modifiers on determination of lipophilicity of tetradentate Schiff bases
The infuences of the application of mono- and two-component organic modifers on lipophilicity determination of 12 tetradentate Schif bases by reversed-phase thin layer chromatography were investigated. The main goal is to estimate types of interaction between observed compounds and components of the applied chromatographic systems and establish some behaviour pattern in order to easier choose a combination of organic modifers which will simulate interaction in biological systems based on the facts that the same basic intermolecular interactions are responsible ...Materials Chemistry, Industrial and Manufacturing Engineering, General Chemical Engineering, Biochemistry,General ChemistryNikola Stevanović, Aleksandar Mijatović, Aleksandar Lolić, Mario Zlatović, Rada Baošić. "Influence of mono- and two-component organic modifiers on determination of lipophilicity of tetradentate Schiff bases" in Chemical Papers, Springer Science and Business Media LLC (2021). https://doi.org/10.1007/s11696-021-01884-5
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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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Development of the Cost-Based Model for Monitoring the Lifetime of the Earth Moving Machines
This paper presents the model for the identification of reference points on the lifetime curve of engineering systems. This curve commonly represents the increase and decline of failure in relation to time. A direct correlation between failure rate and costs is assumed in this paper, therefore, statistical and empirical analysis of costs provided reference points. This approach is used for positioning stages of the engineering system’s lifetime with a minimal number of failures and costs, regardless of whether these ...Electrical and Electronic Engineering,Industrial and Manufacturing Engineering, Control and Optimization, Mechanical Engineering, Computer Science (miscellaneous), Control and Systems EngineeringUgljesa Bugarić, Milos Tanasijević, Stevan Djenadić, Dragan Ignjatović, Ivan Janković. "Development of the Cost-Based Model for Monitoring the Lifetime of the Earth Moving Machines" in Machines, MDPI AG (2022). https://doi.org/10.3390/machines10110995
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Application of softwares for drilling and blasting
U današnje vreme softveri se sve više primenjuju u rudarstvu kroz eksploataciju mineralnih sirovina, projektovanje rudnika, u obavljanju različitih operacija na terenu i sl. Među softverima za rudarstvo, postoje softveri za specifične rudarske operacije, kao što su operacije bušenja i miniranja. Ovi procesi su veoma važni u eksploataciji čvrstih mineralnih sirovina, jer predstavljaju najjeftiniji i najefikasniji oblik fragmentacije stenske mase. Kroz rad, predstavljeni su neki od softvera u kombinaciji sa modernim tehnologijama, koje se koriste širom sveta i koje ...Stefan Milanović, Lazar Kričak, Milanka Negovanović, Nikola Simić, Jovan Marković. "Application of softwares for drilling and blasting" in Podzemni radovi, Beograd : Rudarsko-geološki fakultet (2019). https://doi.org/10.5937/podrad1934077m
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Annotation of the Serbian ELTeC Collection
Ovaj rad predstavlja takozvano izdanje nivoa 2 kolekcije tekstova SrpELTeC razvijene u okviru aktivnosti Radne grupe 2 – Metode i alati COST akcije CA 16204 (Distant Reading for European Literary History) i njene specifikacije šeme. Izdanje nivoa 2 je nastavak izdanja nivoa 1, koje se koristi kao ulaz za morfosintaksičke i NER anotacije romana. Srpska obrada nivoa-2 je navedena kroz potrebne korake, uključujući metode i alate koji se koriste u tom procesu. Neki statistički podaci iz srpske kolekcije nivoa ...udaljeno čitanje, literarni korpus, tagiranje, prepoznavanje imenovanih entiteta, lematizacija, ELTeCRanka Stanković, Cvetana Krstev, Branislava Šandrih Todorović, Mihailo Škorić. "Annotation of the Serbian ELTeC Collection" in Infotheca, Faculty of Philology, University of Belgrade (2021). https://doi.org/10.18485/infotheca.2021.21.2.3
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Резултати иницијалних хидрогеолошких истраживања карстног врела Бијели Нерини (централна Црна Гора)
Врeлo ’’Биjeли Нeрини’’ (305 мнв) нaлaзи нa сjeвeрoзaпaдним oбрoнцимa планине Мaгaник, изнaд кoритa риjeкe Мртвицe (на њеној десној обали). Извoриштe je рaзбиjeнoг типa, кoje je зaтрпaнo крупним блoкoвимa крeчњaкa и дoлoмитa. Извoриштe je вeoмa издaшнo, сa прeтпoстaвкoм дa у минимуму имa приближно 500 л/с, дoк му мaксимум прeлaзи и прeкo 2000 л/с, aли збoг кoнфигурaциje тeрeнa je зa сaдa билo вeoмa тeшкo пoтврдити тe вeличинe. Прeдстaвљa сeгмeнт који упoтпуњуje цjeлoкупну слику геолошких и физичкo-гeoгрaфских спeцифичнoсти кaњoнa риjeкe Мртвицe, десне ...Голуб Ћулафић, Вељко Мариновић, Јелена Крстајић, Бранислав Петровић. "Резултати иницијалних хидрогеолошких истраживања карстног врела Бијели Нерини (централна Црна Гора)" in Записници Српског геолошког друштва (за 2021. годину), Српско геолошко друштво (2022)