Претрага
503 items
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Stratigraphic implications of the Mio-Pliocene geodynamics in the area of Mt. Avala: new evidence from Torlak Hill and Beli Potok (Belgrade, Serbia)
Mt. Avala is located on the southern margin of the Pannonian basin (SPB), a border zone between the uplifted morphostructures of the Dinarides and Carpathian-Balkanides. Similar to the Pannonian basin, tectonostratigraphic evolution of the Mt. Avala area during the last 23 Ma has is characterized by syn- and post-rifting processes as well as tectonic inversion. Here, we present the results of field investigations of the Miocene‒Pliocene dynamics that led to different spatial positions of the same stratigraphic units (e.g. ...... K. (eds.): Géologie de le Serbie. Stratigraphie, II/3, 145–154. EREMIJA, M. (1977b): Pliocen belopotočke rov-sinklinale [Pliocene of the Beli Potok trench-syncline – in Serbian].– In: PETKOVIĆ, K. (eds.): Géologie de le Serbie. Stratigraphie, II/3, 178–181. EREMIJA, M. (1987): Badenski kat [Badenian ...Ljupko Rundić, Meri Ganić, Slobodan Knežević, Dejan Radivojević, Miloš Radonjić. "Stratigraphic implications of the Mio-Pliocene geodynamics in the area of Mt. Avala: new evidence from Torlak Hill and Beli Potok (Belgrade, Serbia)" in Geologia Croatica (2019). https://doi.org/10.4154/gc.2019.11
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Critical disorder and critical magnetic field of the nonequilibrium athermal random-field Ising model in thin systems
Svetislav Mijatović, Dragutin Jovković, Sanja Janićević, Đorđe Spasojević. "Critical disorder and critical magnetic field of the nonequilibrium athermal random-field Ising model in thin systems" in Physical Review E, American Physical Society (APS) (2019). https://doi.org/10.1103/PhysRevE.100.032113
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An optimal sixteenth order family of methods for solving nonlinear equations and their basins of attraction
Dejan Ćebić, Nebojša Ralević, Marina Marčeta. "An optimal sixteenth order family of methods for solving nonlinear equations and their basins of attraction" in Mathematical Communications (2020)
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SrpELTeC: A Serbian Literary Corpus for Distant Reading
U članku je predstavljen SrpELTeC, korpus razvijen u okviru akcije COST Distant Reading for European Literary History (CA16204). Svi romani u SrpELTeC-u su odabrani, pripremljeni i obeleženi korišćenjem zajedničkih principa uspostavljenih za sve jezičke zbirke u Evropskoj zbirci književnog teksta (ELTeC). Navedeni su izazovi i rešenja u pripremi SrpELTeC od nule. Svi romani su ručno kodirani u TEI sa bogatim metapodacima i strukturnim napomenama. Automatska anotacija je uključivala POS-označavanje, lematizaciju i imenovane entitete, oslanjajući se na resurse za obradu ...digital humanities, Serbian literature, text corpora, distant reading , linked data, named entity recognition, text analyticsRanka Stanković, Cvetana Krstev, Duško Vitas. "SrpELTeC: A Serbian Literary Corpus for Distant Reading" in Primerjalna književnost, Research Centre of the Slovenian Academy of Sciences and Arts (2024). https://doi.org/10.3986/pkn.v47.i2.03
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Uticaj utiskivanja gas-lift gasa na prenos mase i toplote
Branko Grubač (2019)Nakon uvođenja kontinualnog gas-lifta, primećen je porast proizvodnje tečnog naftnog gasa, TNG, u postrojenju za preradu gasa, kao jednog od finalnih proizvoda dobijenog iz fluida gaso kondenzatnih i rastvorenog gasa iz naftnih bušotina. Pretpostavljeno je da se prisustvom gas-lift gasa uspostavlja drugačija ravnoteža faza u odnosu na slučaj bez gaslifta, te da je gas-lift gas stripovao propan i butane iz tečne u parnu fazu, što je dovelo do povećanja prinosa TNG-a. Napravljen je model bušotine koja radi u kontinualnom gas-liftu ...... za proračun pada pritiska kroz horizontalne, vertikalne i cevi pod nagibom. Poseban izazov za rad bila je činjenica da u literaturi nije pronađen ni jedan izvor koji opisuje modelovanje protoka fluida od dna do glave bušotine korišćenjem Aspen HYSYS programa. Prvi korak pri modelovanju bila je ...
... koji je tada predstavljao jedini dostupan program u kojem je moguće uraditi simulaciju protoka fluida u cevima. Pregledom literature nisu nađeni ni slični modeli u kojima se Aspen HYSYS koristi pri modelovanju bušotine koja proizvodi u kontinualnom gas-liftu. Postoje drugi specijalistički programi ...
... под насловом Утицај утискивања гас-лифт гаса на пренос масе и топлоте резултат сопственог истраживачког рада; да дисертација у целини ни у деловима није била предложена за стицање друге дипломе према студијским програмима других високошколских установа; да су резултати коректно ...Branko Grubač. Uticaj utiskivanja gas-lift gasa na prenos mase i toplote, Beograd : Rudarsko-geološki fakultet, 2019
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Cutting Resistance Laboratory Testing Methodology for Underwater Coal Mining
... Type of Rock/Soil Strength Index, fpr (MPa) Uniaxial Compressive Strength, σc (MPa) I High-strength rocks Solid and tough quartz and basalt 20 200 II Very hard rocks Porphyritic quartz, granite 15 150 III Hard rocks Granite, hard sandstone, hard iron ore 10 100 IV Relatively hard rocks Normal sandstone ...Vladimir Čebašek, Veljko Rupar, Stevan Đenadić, Filip Miletić. "Cutting Resistance Laboratory Testing Methodology for Underwater Coal Mining" in Minerals, MDPI AG (2021). https://doi.org/10.3390/min11060564
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A Model for Determining Fuzzy Evaluations of Partial Indicators of Availability for High-Capacity Continuous Systems at Coal Open Pits Using a Neuro-Fuzzy Inference System
This paper presents a model for determining fuzzy evaluations of partial indicators of the availability of continuous systems at coal open pits using a neuro-fuzzy inference system. The system itself is a combination of fuzzy logic and artificial neural networks. The system availability is divided into partial indicators. By combining the fuzzy logic and artificial neural networks, a model is obtained that has the ability to learn and uses expert judgment for that learning. This paper deals with the ...системи, континуални системи експлоатације (роторни багер-транспортер-дробилично постројење), рударство, расположивост, меко рачунарство, фази логика, ANN, ANFISMiljan Gomilanović, Miloš Tanasijević, Saša Stepanović, Filip Miletić. "A Model for Determining Fuzzy Evaluations of Partial Indicators of Availability for High-Capacity Continuous Systems at Coal Open Pits Using a Neuro-Fuzzy Inference System" in Energies, MDPI AG (2023). https://doi.org/10.3390/en16072958
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BEYOND 2020 - Geology explorations and open pit activities affectation in reclamation designing in Kolubara Coal Mines (KCM) Serbia, new considerations
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 ...Bojan Dimitrijević, Bogoljub Vučković, Radmila Gaćina. "BEYOND 2020 - Geology explorations and open pit activities affectation in reclamation designing in Kolubara Coal Mines (KCM) Serbia, new considerations" in 17th International Conference of the open and underwater mining of minerals, Sts. Constantine and Helena Resort, Varna, 18-22 September, Bulgaria, Sofia, Bulgaria : Scientific and Technical Union of Mining, Geology and Metallurgy, (2023)
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The influence of Al<sup>3+</sup>ion on porcine pepsin activity<i>in vitro</i>
The in vitro effect of Al3þ ions in the concentration range 1.7·1026M–8.7·1023M on pepsin activity at pH 2, via kinetic parameters and its electrophoretic mobility was evaluated. Kinetic study demonstrated the existence of an activation effect of Al3þ at pH 2 on pepsin molecule. Kinetic analysis with respect to concentrations of haemoglobin showed that Al3þ ions increase the maximal velocity (Vmax) and kcat values rather than apparent affinity for substrate (KS) implying the non-competitive nature of activation which indicated ...... at 1.8A resolutions. J Mol Biol 1990;214:43—170. 8] Cooper JB, Khan G, Taylor G, Tickle IJ, Blundell TL. X-ray analyses of aspartic proteinases. II. Three-dimensional [9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 P+ ...Vesna M. Pavelkić, Kristina R. Gopcević, Danijela Z. Krstić, Marija A. Ilić. "The influence of Al3+ion on porcine pepsin activityin vitro" in Journal of Enzyme Inhibition and Medicinal Chemistry, Informa UK Limited (2008). https://doi.org/10.1080/14756360701841095
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Fuzzy Model for Risk Assessment of Machinery Failures
The main goal of this research was the development of an algorithm for the implementation of negative risk parameters in a synthesis model for a risk level assessment for a specific machine used in the mining industry. Fuzzy sets and fuzzy logic theory, in combination with statistical methods, were applied to analyze the time picture state of the observed machine. Fuzzy logic is presented through fuzzy proposition and a fuzzy composition module. Using these tools, the symmetric position of the ...... s for three fuzzy sets is C = j3. If a low number is used for j, problems can occur upon composition because there are gaps in the final result; (ii) Only the combinations whose membership function values are different from zero are taken for further analysis, µS,O,D j=1, . . . , 10 ,0, j = 1, ...
... Using stakeholders’ judgement and fuzzy logic theory to analyze the risk influencing factors in oil and gas pipeline projects: Case study in Iraq, Stage II. Int. J. Crit. Infrastruct. Prot. 2020, 28, 100337. [CrossRef] 20. Ataei, M.; Khalokakaie, R.; Hossieni, M. Determination of coal mine mechanization ...Dejan V. Petrović, Miloš Tanasijević, Saša Stojadinović, Jelena Ivaz, Pavle Stojković. "Fuzzy Model for Risk Assessment of Machinery Failures" in Symmetry, MDPI AG (2020). https://doi.org/10.3390/sym12040525
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Laboratory testing of fly ash
Fly ash is one of the most common waste materials created by burning of coal. It is composed of smaller particles, consisting mainly of aluminosilicate glass, mullite and quartz, which are collected by electrostatic separators (filter) of gaseous products arising from the combustion of coal. This paper presents the pozzolanic properties, mechanical properties, chemical and mineral composition of fly ash obtained in the combustion process in a power plant Nikola Tesla A (PPNT A) with the addition of a ...chemical composition, fly ash, mechanical properties, mineral properties, pozzolanic properties, X-ray diffraction... classification Table 2 The international system of classification of fly ash Group Ash SiO2/Al2O3 CaO / % SO3 I Aluminosilicate >2 <15 undefined II Silicate - Aluminate <2 <15 <3 III Sulfate - Alkaline undefined >15 >3 IV Other (lime) undefined >15 <3 2. The classification of fly ash ...Miloš Šešlija, Aleksandra Rosić, Nebojša Radović, Milinko Vasić, Mitar Đogo, Milovan Jotić. "Laboratory testing of fly ash" in Tehnički vijesnik (2016). https://doi.org/10.17559/TV-20150317171035
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The application of ArcGIS for assessing the potential of solar energy in urban area: The case of Vranje
In order to determine the solar energy potential for a specified location, it is crucial to consider the latitude, altitude, slope, terrain morphology, atmospheric conditions, etc. Such a complex calculation and mapping of solar energy can be done using the ArcGIS geoprocessing tool, named Area Solar Radiation (ASR). By using the ASR tool, supported with the adequate input data, it is possible to calculate the maximum solar radiation energy (irradiation) for a defined area and for a specified time ...... language". Pavlovic, T. Milosavljevic, D., Lambić, M., et al., 2011. "Solar energy in Serbia". Contemporary Materials (Renewable energy sources), Volume II-2, pp. 204 - 209. PBC GIS, 2019. Site Modeling in Context - Obtaining And Transforming Elevation Data, pbc Geographic Information Services, available ...Boban Pavlović, Milica Pešić-Georgiadis. "The application of ArcGIS for assessing the potential of solar energy in urban area: The case of Vranje" in 12th International Conference on Energy and Climate Change, 9-11 October 2019, Athens - Greece, Energy Policy and Development Centre (KEPA) of the National and Kapodistrian University of Athens (2019)
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Mitigating hydrate formation in onshore gas wells: A case study on optimization techniques and prevention
Gas wells, particularly those situated onshore, play a vital role in the global energy sector by supplying a significant portion of natural gas. However, operational challenges, notably gas hydrate formation, pose substantial issues, leading to complications such as flowline blockages and unexpected well shutdowns. Gas hydrates, crystalline structures resembling ice, ...Gas Well, Gas Hydrate Formation, Well Modeling, Well Performance Optimization, Choke Position Adjustments, Methanol InjectionMilica Ješić, Bojan Martinović, Stefan Stančić, Miroslav Crnogorac, Dušan Danilović. "Mitigating hydrate formation in onshore gas wells: A case study on optimization techniques and prevention" in Underground Mining Engineering, Beograd : Rudarsko-geološki fakultet (2023)
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Towards Better Valorisation of Industrial Minerals andRocks in Serbia—Case Study of Industrial Clays
... Critical Parameters Ex og en ou s Weathering Residual Novi Pazar area Common brick and blocks Low clay fraction Se di m en ta ry M ec ha ni ca l s ed im en ts Deluvial-proluvial Novi Pazar, Vrčin Common brick and blocks Low clay fraction Alluvial-marsh Bečej (Rit) Common brick ...Vladimir Simić, Dragana Životić, Zoran Miladinović. "Towards Better Valorisation of Industrial Minerals andRocks in Serbia—Case Study of Industrial Clays" in Resources, MDPI AG (2021). https://doi.org/10.3390/resources10060063
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Spatial assessment of the areas sensitive to degradation in the rural area of the municipality Čukarica
Nature and Landscape Conservation, Soil Science, Agronomy and Crop Science, Water Science and TechnologyNatalija Momirović, Ratko Kadović, Veljko Perović, Miloš Marjanović, Aleksandar Baumgertel. "Spatial assessment of the areas sensitive to degradation in the rural area of the municipality Čukarica" in International Soil and Water Conservation Research, Elsevier BV (2019). https://doi.org/10.1016/j.iswcr.2018.12.004
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Valorization of non-balanced coal reserves in Serbia for underground coal gasification
David Petrović, Lazar Kričak, Milanka Negovanović, Stefan Milanović, Jovan Marković, Nikola Simić, Ljubisav Stamenić (2019)In the name of a better and safer energy future, it is our responsibility to focus our knowledge and activities to save on imported liquid and gas fossil fuels, as well as coal on which energy security of Serbia is based. The rationalization in the use of available energy resources certainly positively affects economy and the environment of a country. This paper indicates motivations for the application of the underground coal gasification process, as well as surface gasification for ...... the borehole and blowing the low pressure air. Instead of firing coal layer with the coke at high temperatures, a – — —- 225 – — — Product gas W j ii manifold 75 75 i 75 H ' · H I Drilling -—Q - and preparing || ' Row5 _ ć____ O—- Boreholes ! Figure 2. Plan view of the grid between ...David Petrović, Lazar Kričak, Milanka Negovanović, Stefan Milanović, Jovan Marković, Nikola Simić, Ljubisav Stamenić. "Valorization of non-balanced coal reserves in Serbia for underground coal gasification" in Thermal Science (2019). https://doi.org/10.2298/TSCI190725390P
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Analiza primenjenih metoda za transport parafinske nafte
Dunja Milojević (2024)Sadržaj parafina u nafti ima dominantan uticaj na svojstva parafinskih nafti. Taloženje parafina, odnosno taloženje čvrstih čestica parafinskog voska, predstavlja ozbiljan globalni problem tokom proizvodnje i transporta sirove nafte. Samo taloženje voska zavisi od termodinamičkih faktora, poput temperature, pritiska i sastava nafte. Transport nafte cevovodima je uobičajeni proces transporta u naftnoj industriji. Kada prilikom cevovodnog transporta parafinske sirove nafte, dođe do prekida protoka i hlađenja nafte ispod temperature stinjavanja, parafini će kristalisati, pri čemu će doći do, geliranja celokupne transportovane ...... rastvoreni. Ako se nafta sa tako visokom temperaturom podvrgne brzom hlađenju, onda će doći do stvaranja brojnih nezavisnih kristala parafina koji se ni kod temperature od 20%C neće spajati ı formirati prostornu rešetku. Usled brzog hlađenja dolazi do stvaranja disperznog sistema sa fino dispergovanim ...Dunja Milojević. Analiza primenjenih metoda za transport parafinske nafte, 2024
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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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FrameNet Lexical Database: Presenting a Few Frames Within the Risk Domain
U radu se daje kratak prikaz teorije semantike okvira, na kojoj je zasnovana leksička baza Frejmnet. Predstavljena je koncepcija ove mreže, kao i mogućnosti njene primene. Predstavljena je i leksička analiza koja se primenjuje u projektu izrade Frejmneta i ukazano na razlike između analize zasnovane na okviru u odnosu na analizu zasnovanu na reči. Zatim je prikazano nekoliko povezanih okvira koje prizivaju reči iz domena rizika. U radu je predstavljena i platforma NLTК pomoću koje se mogu koristiti ...... Linguistics (ACL’05), 581–588. Ruppenhofer, Josef, Michael Ellsworth, Myriam Schwarzer-Petruck, Christo- pher R Johnson, and Jan Scheffczyk. 2016. FrameNet II: Extended the- ory and practice. Revised November 1, 2016. https :// framenet . icsi . berkeley.edu/fndrupal/the_book. 32 Infotheca Vol. 21, No. 1, ...Aleksandra Marković, Ranka Stanković, Natalija Tomić, Olivera Kitanović. "FrameNet Lexical Database: Presenting a Few Frames Within the Risk Domain" in Infotheca, Faculty of Philology, University of Belgrade (2021). https://doi.org/10.18485/infotheca.2021.21.1.1
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Damage quantification of built stone on Dark Gate (Belgrade, Serbia): sample of damage index application for decay rate evaluation
The Dark Gate is the monument of culture, part of the cultural and historical complex of the Belgrade Fortress. It is constructed of limestone blocks that after 270 years of exposure to environmental conditions and different anthropogenic influences show wide ranges of decay forms. During 2007, detail registration of all built limestone microfacies and weathering forms was done using tools of monument mapping. A correlation scheme ‘‘intensity– damage category’’ was made according to the type, intensity, and distribution of ...... Stockholm, Kwiatkowski D and Lofvendahi R (ed) IOth International congress on deterioration and conservation of stone, Preprints, ICOMOS Sweden, Vol. II, Elanders Gotab, Stockholm, pp 691698 Doehne E, Price C (2010) Stone conservation: an overview of current research, 2nd edn. J. Paul Getty Trust ...Maja Franković, Nevenka Novaković, Vesna Matović. "Damage quantification of built stone on Dark Gate (Belgrade, Serbia): sample of damage index application for decay rate evaluation" in Environmental Earth Sciences, Springer Science and Business Media LLC (2015). https://doi.org/10.1007/s12665-014-3843-z