Претрага
490 items
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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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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
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Characterization and Environmental Evaluation of Recycled Aggregates from Construction and Demolition Waste in Belgrade City Area (Serbia)
Filip Abramović, Miroslav Popović, Vladimir Simić, Vesna Matović, Radmila Šerović. "Characterization and Environmental Evaluation of Recycled Aggregates from Construction and Demolition Waste in Belgrade City Area (Serbia)" in Materials, MDPI AG (2024). https://doi.org/10.3390/ma17040820
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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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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... aktivnog podzemnog rudnika zasnovana na teoriji sivih sistema rezultat sopstvenog istraţivaĉkog rada, da predloţena disertacija u celini ni u delovima nije bila predloţena za dobijanje bilo koje diplome prema studijskim programima drugih visokoškolskih ustanova, da su rezultati korektno ...
... Milo Tomašević. Od 2002. godine radi u Višoj elektrotehniĉkoj školi u Beogradu kao struĉni saradnik na predmetima: Programiranje I, Programiranje II, Uvod u operativne sisteme, Objektno programiranje i Programiranje u jeziku Java, Matematika 1 i Matematika 2 i Inţenjerska matematika. Od 2012 ...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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Investigating distant effects of the Moesian promontory: Brittle tectonics along the western boundary of the Getic unit (East Serbia)
In this study, we report evidence for brittle deformation in a part of the Carpatho–Balkan orogen, which is explained in terms of effects of the rigid Moesian promontory of the European plate on fault kinematics in East Serbia. We focus on the westernmost part of the Getic Unit of the East Serbian Carpatho–Balkanides, i.e. the Gornjak–Ravanica Unit, located between two main thrusts that were repeatedly activated from Early Cretaceous to recent times. We combine a new data set on ...Getikum, Mezijska jedinica, Karpato-balkanski orogen, krte deformacije, Gornjačko-ravanička jedinicaAna Mladenović, Milorad D. Antić, Branislav Trivić, Vladica Cvetković. "Investigating distant effects of the Moesian promontory: Brittle tectonics along the western boundary of the Getic unit (East Serbia)" in Swiss Journal of Geosciences, Springer (2019). https://doi.org/10.1007/s00015-018-0324-5
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Pleistocene rhinoceros from Bogovina Cave: the first report of Stephanorhinus hundsheimensis Toula, 1902 (Mammalia, Rhinocerotidae) from Serbia
Finds of Pleistocene rhinoceros are rare in Serbia, and only one species (the woolly rhinoceros Coelodonta antiquitatis Blumenbach, 1799) has been reported so far. The current paper presents the dental material of an extinct so-called Hundsheim rhinoceros, Stephanorhinus hundsheimensis Toula, 1902 from Bogovina Cave (East ern Serbia). Both the morphological and metric characteristics of the teeth are consis tent with the attribution to S. hundsheimensis. Unfortunately, the rhinoceros material originated from an uncertain geological context, so there is no ...... https://doi.org/10.2517/2015PR034 Kahlke, H.-D. 1965. Die Rhinocerotiden-Reste aus den Tonen von Voigtstedt in Thüringen. Paläontologische Abhandlungen, A II:451-519. Kahlke, H.-D. 1969. Die Rhinocerotiden-Reste aus den Kiesen von Süßenborn bei Weimar. Paläontologische Abhandlungen, A III:667-708. Kahlke ...Predrag Radović, Miloš Radonjić, Emmanuel Billia. "Pleistocene rhinoceros from Bogovina Cave: the first report of Stephanorhinus hundsheimensis Toula, 1902 (Mammalia, Rhinocerotidae) from Serbia" in Palaeontologia Electronica, Coquina Press (2020). https://doi.org/10.26879/985
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Overcoming the Low Oral Bioavailability of Deuterated Pyrazoloquinolinone Ligand DK-I-60-3 by Nanonization: A Knowledge-Based Approach
Jelena R. Mitrović , Branka Divović-Matović, Daniel E. Knutson, Jelena B. Ðoković, Aleksandar Kremenović, Vladimir D. Dobričić, Danijela V. Randjelović, Ivana Pantelić, James M. Cook, Miroslav M. Savić, Snežana D. Savić (2021)Poor water solubility of new chemical entities is considered as one of the main obstacles in drug development, as it usually leads to low bioavailability after administration. To overcome these problems, the selection of the appropriate formulation technology needs to be based on the physicochemical properties of the drug and introduced in the early stages of drug research. One example of the new potential drug substance with poor solubility is DK-I-60-3, deuterated pyrazoloquinolinone, designed for the treatment of various neuropsychiatric ...... animals were divided into four groups, each group containing 18 an- imals (three animals per time point): group I received F5 in fasted conditions, group II received F5 in fed conditions, group III received S5 in fasted conditions, and group IV received S5 in fed conditions. The test formulations were ad ...Jelena R. Mitrović , Branka Divović-Matović, Daniel E. Knutson, Jelena B. Ðoković, Aleksandar Kremenović, Vladimir D. Dobričić, Danijela V. Randjelović, Ivana Pantelić, James M. Cook, Miroslav M. Savić, Snežana D. Savić. "Overcoming the Low Oral Bioavailability of Deuterated Pyrazoloquinolinone Ligand DK-I-60-3 by Nanonization: A Knowledge-Based Approach" in Pharmaceutics, MDPI, Basel, Switzerland (2021). https://doi.org/10.3390/pharmaceutics13081188
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Comprehensive Profiling of Microbiologically Induced CaCO3 Precipitation by Ureolytic Bacillus Isolates from Alkaline Soils
Olja Šovljanski, Lato Pezo, Jovana Stanojev, Branimir Bajac, Sabina Kovač, Elvira Tóth, Ivan Ristić, Ana Tomić, Aleksandra Ranitović, Dragoljub Cvetković, Siniša Markov (2021)MICP process, kinetic study, calcite, vaterite, MALDI-TOF identification, Bacillus licheniformis, Sporosarcina pasteurii... parameters of being optimal. For examination of the MICP potential, bacteria were grown on: (i) Urea base agar and broth (HiMedia, Mumbai, India), (ii) Urea-CaCl2 agar and broth [20], and (iii) YE-CaCl2 agar and broth (modified of Urea-CaCl2 media; Urea was replaced with 4.0 g/L yeast extract). Overnight ...Olja Šovljanski, Lato Pezo, Jovana Stanojev, Branimir Bajac, Sabina Kovač, Elvira Tóth, Ivan Ristić, Ana Tomić, Aleksandra Ranitović, Dragoljub Cvetković, Siniša Markov. "Comprehensive Profiling of Microbiologically Induced CaCO3 Precipitation by Ureolytic Bacillus Isolates from Alkaline Soils" in Microorganisms, MDPI AG (2021). https://doi.org/10.3390/microorganisms9081691
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Curcumin nanonization using an alternative small-scale production unit: selection of proper stabilizer applying basic physicochemical consideration and biological activity assessment of nanocrystals
Ines Nikolić, Jelena Antić-Stanković, Dragana Božić, Danijela Ranđelović, Bojan Marković, Dominique Jasmin Lunter, Aleksandar Kremenović, Miroslav Savić, Snežana Savić (2020)As the number of poorly soluble drugs is increasing, nanocrystals have become very interesting due to wide range of application possibilities. Curcumin was used as a model active ingredient in this work. Even though it has many proven positive effects, due to its physicochemical issues, its possibilities have not been fully exploited. The goal of this work was to select optimal conditions for a top-down method for curcumin nanosuspension production, and to perform their comprehensive characterization applying complementary methodologies: ...Ines Nikolić, Jelena Antić-Stanković, Dragana Božić, Danijela Ranđelović, Bojan Marković, Dominique Jasmin Lunter, Aleksandar Kremenović, Miroslav Savić, Snežana Savić. "Curcumin nanonization using an alternative small-scale production unit: selection of proper stabilizer applying basic physicochemical consideration and biological activity assessment of nanocrystals" in Review on advanced materials science, Walter de Gruyter GmbH (2020). https://doi.org/10.1515/rams-2020-0043
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The Reciprocal Algebraic Integers Having Small House
Dragan Stankov (2021)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 Reciprocal Algebraic Integers Having Small House" in Experimental Mathematics (2021). https://doi.org/ 10.1080/10586458.2021.1982425
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Adsorption and degradation of some psychiatric drugs by sol-gel synthesized titania-based photocatalysts: influence of tungsten and sodium content
Nina L. Finčur, Maja J. Šćepanović, Mirjana Grujić-Brojčin, Biljana F. Abramović, Jugoslav B. Krstić, Aleksandar Kremenović, Tatjana Srećković, Aleksandar Golubović (2019)Mesoporous anatase nanopowders were doped with 0.05−0.5 mol% of W6, in order to obtain more efficient photocatalyst than TiO2 Degussa P25 in the degradation of amitriptyline (AMI) under simulated solar irradiation (SSI). Dominant XRPD peaks were ascribed to anatase phase, with additional peaks which could correspond to brookite, TiO2 bronze and sodium titanate, Na2Ti9O19. The Raman scattering measurements have confirmed anatase as dominant phase, with broad Raman feature at ~270 cm−1 possibly related to Ti–O–Na stretching vibration. All W-doped ...Sol-gel synthesis, Doped titania nanopowders, XRPD, Raman spectroscopy, Adsorption and photocatalytic degradation, Psychiatric drugsNina L. Finčur, Maja J. Šćepanović, Mirjana Grujić-Brojčin, Biljana F. Abramović, Jugoslav B. Krstić, Aleksandar Kremenović, Tatjana Srećković, Aleksandar Golubović. "Adsorption and degradation of some psychiatric drugs by sol-gel synthesized titania-based photocatalysts: influence of tungsten and sodium content" in Journal of Sol-Gel Science and Technology, Springer Science and Business Media LLC (2019). https://doi.org/10.1007/s10971-019-04925-4
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Structural and geochronological constraints from the Drina-Ivanjica thrust sheet (Western Serbia): implications for the Cretaceous–Paleogene tectonics of the Internal Dinarides
Kristof Porkoláb, Szilvia Kövér, Zsolt Benkó, Gabor Héja, Melinda Fialowski, Balázs Soós, Nataša Gerzina Spajić, Nevenka Đerić, László Fodor (2019)Internal Dinarides, Drina-Ivanjica thrust sheet, Deformation history, K–Ar dating, Obduction, Structural analysis... Bosnian-Durmito! Ivanjica D2 - stage 2 | _Updoming due to continuous NE-SW shonening -_ t9 4 - stage loming due to continuous NE-SW shortenini SW g ii d NIŽ Syn- to post-Albian-Campanian shortening (late D2) SW NE Fig. 7 a SSW-NNE geological cross-section across the study area showing a possible ...Kristof Porkoláb, Szilvia Kövér, Zsolt Benkó, Gabor Héja, Melinda Fialowski, Balázs Soós, Nataša Gerzina Spajić, Nevenka Đerić, László Fodor. "Structural and geochronological constraints from the Drina-Ivanjica thrust sheet (Western Serbia): implications for the Cretaceous–Paleogene tectonics of the Internal Dinarides" in Swiss Journal of Geosciences (2019)
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Concepts for Improving Machine Learning Based Landslide Assessment
Miloš Marjanović, Mileva Samardžić Petrović, Biljana Abolmasov, Uroš Đurić. "Concepts for Improving Machine Learning Based Landslide Assessment" in Natural Hazards GIS-based Spatial Modeling Using Data Mining Techniques, Advances in Natural and Technological Hazards Research, volume 48, Springer Nature Switzerland AG 2019 (2019). https://doi.org/10.1007/978-3-319-73383-8_2
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Machine learning based landslide assessment of the Belgrade metropolitan area: Pixel resolution effects and a cross-scaling concept
Improvements of Machine Learning-based landslide prediction models can be made by optimizing scale, customizing training samples to provide sets with the best examples, feature selection, etc. Herein, a novel approach, named Cross-Scaling, is proposed that includes the mixing of training and testing set resolutions. Hypothetically, training on a coarser resolution dataset and testing the model on a finer resolution should help the algorithm to better generalize ambiguous examples of landslide classes and yield fewer over/underestimations in the model. This ...Uroš Đurić, Miloš Marjanović, Zoran Radić, Biljana Abolmasov. " Machine learning based landslide assessment of the Belgrade metropolitan area: Pixel resolution effects and a cross-scaling concept" in Engineering Geology , Elsevier (2019). https://doi.org/10.1016/j.enggeo.2019.05.007