Претрага
329 items
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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 ...... ma/days , i. e. 10070m,/h, m\, =10070 m\/h (15) 120 days Sometimes in calculations and various design checks it is sometimes operated with the parameter of the gas production per 1 m thickness of the layer. Calculating per 1 m of the layer thickness, this gas production becomes 1783 mi /h. The obtained ...
... different physical-chemical conditions and interdependencies, where the concentration of dissolved substances in them is much more diverse and changes according to the specific rules all the time. This is especially the case with the flow of aquifer waters, where the pollution process itself, ...
... concentration of pollutants to the allowed values according to the adopted norms, which are of interest from the perspective of the forecast of changes in the water quality of the aquifer. Measures of preventive character are those that can prevent the possibility of con- tamination of groundwater ...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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Influence of paleoenvironmental conditions on distribution and relative abundance of saturated and aromatic hydrocarbons in sediments from the NW part of the Toplica basin, Serbia
Nikola Burazer, Aleksandra Šajnović, Nebojša Vasić, Milica Kašanin-Grubin, Dragana Životić, João Graciano Mendonça Filho, Predrag Vulić, Branimir Jovančićević (2020)Nikola Burazer, Aleksandra Šajnović, Nebojša Vasić, Milica Kašanin-Grubin, Dragana Životić, João Graciano Mendonça Filho, Predrag Vulić, Branimir Jovančićević. "Influence of paleoenvironmental conditions on distribution and relative abundance of saturated and aromatic hydrocarbons in sediments from the NW part of the Toplica basin, Serbia" in Marine and Petroleum Geology, Elsevier BV (2020). https://doi.org/10.1016/j.marpetgeo.2020.104252
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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. ...... length (~ 2km) and plotted on a rose diagram (Fig. 17b). The statistical interpretation of the linear features (ori- entation of river valleys, changes of slope angles, and sharp turns of water flows, etc.) as well as the main fault categories separated in the wider area of Mt. Avala (MAROVIĆ & KNEŽEVIĆ ...
... fluvial phase of relief formation began (MAROVIĆ & KNEŽEVIĆ, 1985). During that time, as the uplift of Torlak Hill progressed, the Zavojnička Reka changes its flow from SE-NW and turns to- wards the E-NE, away from Torlak. This activity led to the for- mation of the new, local structure along which the ...
... MAROVIĆ, M., DJOKOVIĆ, I., KNEŽEVIĆ, S., RUNDIĆ, Lj., MITROVIĆ, S., ŠUMAR, M. & TOLJIĆ, M. (1995): Principal geodynamic stages and paleogeographic changes in southeastern Peripannonian realm of Neogene and Quaternary.‒ Proc. XV Congress C.B.G.A., Geol. Soc. Greece, Athens, sp. publ., 4/1, 69‒73. MAROVIĆ ...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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Nonequilibrium athermal random-field Ising model on hexagonal lattices
Svetislav Mijatović, Dragutin Jovković, Đorđe Spasojević. "Nonequilibrium athermal random-field Ising model on hexagonal lattices" in Physical Review E, American Physical Society (APS) (2021). https://doi.org/10.1103/PhysRevE.103.032147
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A Tel Platform Blending Academic And Entrepreneurial Knowledge
... curricula in ever shortening intervals is a solution that is increasingly harder to achieve. Namely, while technology is rapidly developing, changes in academic programs are subject to procedures that are often time-consuming and slow. On the other hand, academic knowledge that graduate ...Ivan Obradović, Ranka Stanković, Jelena Prodanović, Olivera Kitanović. "A Tel Platform Blending Academic And Entrepreneurial Knowledge" in Proceedings of the The Fourth International Conference on e-Learning (eLearning-2013), September 2013, Belgrade, Serbia, Belgrade, Serbia : Belgrade Metropolitan University (2013)
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Flyrock induced by blasting in surface mining
Milanka Negovanović, Lazar Kričak, Snežana Ignjatović, Stefan Milanović, Jovan Marković, Nikola Simić, Rade Šarac (2022)Miniranje predstavlja i dalje najefikasniji i najjeftiniji način eksploatacije velikih količina čvrstih mineralnih sirovina na površinskim kopovima. Energija eksplozije se koristi za fragmentaciju čvrste stenske mase do zahtevane granulacije. Pored pozitivnih efekata miniranja, postoje i određeni neželjeni efekti svakog procesa miniranja koji se mogu javiti, a to su: potresi tla, razletanje komada stene, vazdušni udari, otrovni i zagušljivi gasovi i prašina. Razletanje komada stene je nekontrolisano izbacivanje fragmenata odminirane stenske mase i predstavlja jedan od glavnih izvora materijalne štete ...Milanka Negovanović, Lazar Kričak, Snežana Ignjatović, Stefan Milanović, Jovan Marković, Nikola Simić, Rade Šarac. "Flyrock induced by blasting in surface mining" in Rudarski glasnik, Beograd : Rudarski institut (2022). https://doi.org/10.25075/BM.2022.05
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A hydrogeological model of the open-cast mine Tamnava - West Field (Kolubara Coal Basin, Serbia)
... MEKERK, F.A. (1993) A phased approach to mine dewatering. Mine Water and Environment, 12 (1), pp. 27-33. NIEDBALSKA, K. et al. (2011) Modelling of changes of hydrodynamic conditions in the aquatic environment of the Maczki-Bór sand pit due to the fact of planned closure of mining operations (NE part ...Jelena Ratković, Dušan Polomčić, Dragoljub Bajić, Bojan Hajdin. "A hydrogeological model of the open-cast mine Tamnava - West Field (Kolubara Coal Basin, Serbia)" in Underground Mining Engineering no. 29, Belgrade : University of Belgrade - Faculty of mining and geology (2016): 43-54
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Mine ventilation system planning using genetic algorithms
The most common problem in contemporary mining practice related to the planning and analysis of ventilation systems is the optimization of partially regulated air distribution in mine ventilation networks. This paper presents a two step optimization procedure for partly regulated air distribution in mine ventilation networks. The first step is the determination of air distribution in all branches using the well known Hardy-Cross method. In the second step the distribution and parameters of air flow regulators with minimum engaged ...coal, lignite, and peat; ventilation systems; coal mining; underground mining; ventilation; mathematical models; design; air flow; optimization; calculation methodsNikola Lilić, Ranka Stanković, Ivan Obradović. "Mine ventilation system planning using genetic algorithms" in 6. international symposium on mine planning and equipment selection, Ostrava (Czech Republic), 3-6 Sep 1997, A.A. Balkema, Rotterdam (Netherlands) (1997)
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VENTEX: An Expert System for Mine Ventilation Systems Analysis
Analiza sistema za ventilaciju je komleksan proces, koji bazira na proračunu brojnih parametara, koji se odnose na: stanje mreže, provetrenost, stabilnost sistema, gubitke vazduha, klimatske uslove, gasno stanje, ugroženost od požara i opasne prašine. Navedeni problemi se uspešno rešavaju paketom SimVent, ali potpuno razumevanje i korišćenje dobijenih rezultata zahteva angažovanje iskusnog specijaliste iz oblasti ventilacije. Rešenje je nađeno u kreiranju ekspertnog sistema VENTEX, čija je baza znanja formalizacija ekspertskog znanja iz oblasti ventilacije rudnika. U radu je prikazana metodologija ...... state, fire risk and harmful dust risk. Once the parameter values are obtained the estimation process for the general ventilation state of the mine may begin. During this process, the importance, i.e. significance of each particular parameter must be taken into account. The estimation task ...
... by backward chaining are defined by means of the goal editor as shown on /Fig. 9/. The goals in VENTEX pertain to estimation of different parameter values. A decomposition of the goal VentNetwork into subgoals is illustrated in /Fig. 9/. Figure 9. The VentNetwork Goal Goals can also ...
... be made if the conditions are true. The conclusions may represent logical deductions about the knowledge base or specifications of how it changes over time. Each rule is a relatively independent module, which made it possible to build the reasoning systems gradually, rule by rule. Figure ...Ranka Stanković, Nikola Lilić, Ivan Obradović. "VENTEX: An Expert System for Mine Ventilation Systems Analysis" in YU Info '96 Brezovica, Društvo za informacione sisteme i računarske mreže (1996)
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3D modeling and monitoring of karst system as a base for its evaluation and utilization: a case study from eastern Serbia
Earth-Surface Processes, Geology, Pollution, Soil Science, Water Science and Technology, Environmental Chemistry, Global and Planetary ChangeSaša Milanović, Zoran Stevanović, Ljiljana Vasić, Vesna Ristić-Vakanjac. "3D modeling and monitoring of karst system as a base for its evaluation and utilization: a case study from eastern Serbia" in Environmental Earth Sciences, Springer Science and Business Media LLC (2013). https://doi.org/10.1007/s12665-013-2591-9
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Improvement of education through the cooperation between CEEPUS EURO Geo-Sci network and scientific projects: examples from UB-FMG
Kristina Šarić, Dejan Prelević, Miloš Marjanović, Uroš Stojadinović, Vladimir Simić . "Improvement of education through the cooperation between CEEPUS EURO Geo-Sci network and scientific projects: examples from UB-FMG" in V Congress of Geologists of Republic of Macedonia ": “Geology in a changing world”, Makedonsko geološko društvo (2024)
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Insights into dike nucleation and eruption dynamics from high-resolution seismic imaging of magmatic system at the East Pacific Rise
Milena Marjanović, Suzanne M. Carbotte, Alexandre Stopin, Satish C. Singh, René-Édouard Plessix, Miloš Marjanović, Mladen R. Nedimović, Juan Pablo Canales, Hélène D. Carton, John C. Mutter, Javier Escartín (2023)Milena Marjanović, Suzanne M. Carbotte, Alexandre Stopin, Satish C. Singh, René-Édouard Plessix, Miloš Marjanović, Mladen R. Nedimović, Juan Pablo Canales, Hélène D. Carton, John C. Mutter, Javier Escartín. "Insights into dike nucleation and eruption dynamics from high-resolution seismic imaging of magmatic system at the East Pacific Rise" in Science Advances, American Association for the Advancement of Science (AAAS) (2023). https://doi.org/10.1126/sciadv.adi2698
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Evidence of Variscan and Alpine tectonics in the structural and thermochronological record of the central Serbo-Macedonian Massif (south-eastern Serbia)
... ductile fabric could be followed throughout the entire study area (i.e. central SMM), as abrupt changes in orientation of structural elements occur even within rela- tively small areas (Fig. 3). These changes are considered to result from a much younger brittle tectonic overprint. The structural ...
... Božica areas with transitional metamorphic grade between amphibolite and greenschists facies probably held intermediate crustal positions. Abrupt changes in metamorphic grade observed across brittle thrusts in the castern part of the study area could be explained by telescoping during the Cretaceous ...
... western and eastern parts of the Galatian super- @ Springer 1688 terrane and subsequent collision with Laurussia, which could account for the changes in direction of strain axes during D, and D,. • A trend of diminishing strain and metamorphic grade from amphibolite facies in the Lower Complex ...Milorad D. Antić, Alexandre Kounov, Branislav Trivić, Richard Spikings, Andreas Wetzel. "Evidence of Variscan and Alpine tectonics in the structural and thermochronological record of the central Serbo-Macedonian Massif (south-eastern Serbia)" in International Journal of Earth Sciences, Springer Science and Business Media LLC (2016). https://doi.org/10.1007/s00531-016-1380-6
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Early–Middle Jurassic brachiopods from Ponor Mountain, Western Balkan Mountains, Bulgaria; taxonomy, biostratigraphy and occurrence in the context of the early Toarcian Oceanic Anoxic Event
Barbara V. Radulović, Lubomir S. Metodiev, Neda Motchurova-Dekova, Platon Tchoumatchenco. "Early–Middle Jurassic brachiopods from Ponor Mountain, Western Balkan Mountains, Bulgaria; taxonomy, biostratigraphy and occurrence in the context of the early Toarcian Oceanic Anoxic Event" in Historical Biology (2023). https://doi.org/10.1080/08912963.2023.2190757
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Development of Open Educational Resources (OER) for Natural Language Processing
In this paper we present the development of an online course at the edX BAEKTEL platform named “Lexical Recognition in the Natural Language Processing (NLP)”. It is based on the course of the same name for PhD studies at the University of Belgrade, Faculty of Philology. There are not many courses in Computational Linguistics (CL) on OER platforms, and there is none in Serbian either for CL or NLP. We have developed this course in order to improve this ...... formats is important because they usually represent the input or the output for Unitex and it is important for the user to follow the changes that are occurring with the implementation of the graphs. Graphs and transducers are represented in grf format, a Unitex specific readable ...Cvetana Krstev, Biljana Lazić, Ranka Stanković, Giovanni Schiuma, Miladin Kotorčević. "Development of Open Educational Resources (OER) for Natural Language Processing" in The Sixth International Conference on e-Learning (eLearning-2015), September 2015, Belgrade, Serbia, Belgrade : Belgrade Metropolitan Univesity (2015)
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Phase relations and physical indicators of municipal waste from old landfills in Serbia
Due to certain similarities of municipal waste and soil, usually for the determination of basic parameters of physical state, laboratory and field tests which are common in geotechnical investigations are used. It is often to construct an apparatus for special purpose to perform some specific laboratory and field tests. Therefore, different values of indicators of municipal waste physical state can be found in the literature. The basic reasons should be found in different definitions and methods that researchers use ...municipal waste, moisture content, unit weight, specific gravity, grain size distribution, porosityGeneral Computer Science... geotechnical practice can be derived. Table 1. Definition of the most important physical parameters of municipal waste (Fassett et al., 1994). Parameter Mark Unit Relations Unit weight Y kN/m) Y=W/V=(I+w) ·Ya Void ratio e mš/m* e= V /V, = | ___I-n Unit weight W a of solid A kN/m* E i ——— particles ...
... municipal waste does not take into account a fact that the composition and thus the volume of organic materials, i.c. part of a solid phase, 106 changes over time. Therefore, it should be noted that there is a different representation of municipal waste phase composition, where the four-phase system ...Dragoslav R Rakić, Irena G Basarić Ikodinović, Jovana M Janković, Tina D Đurić. "Phase relations and physical indicators of municipal waste from old landfills in Serbia" in Japanese Geotechnical Society Special Publication, The Japanese Geotechnical Society (2021). https://doi.org/10.3208/jgssp.v09.cpeg016
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Fuzzy optimization in hydrodynamic analysis of groundwater control systems: Case study of the pumping station “Bezdan 1”, Serbia
Dragoljub Bajić, Dušan Polomčić (2014)A groundwater control system was designed to lower the water table and allow the pumping sta-tion “Bezdan 1” to be built. Based on a hydrodynamic analysis that suggested three alternative solutions, mul-ticriteria optimization was applied to select the best alternative. The fuzzy analytic hierarchy process methodwas used, based on triangular fuzzy numbers. An assessment of the various factors that influenced the selec-tion of the best alternative, as well as fuzzy optimization calculations, yielded the “weights” of the alternativesand the ...groundwater lowering, groundwater management scenario, fuzzy analytic hierarchy process,expert knowledge, triangular fuzzy numbers, linguistic variables... some cases the construction of wells is more economical than the pumping time. Flexibility included the ability of the system to adapt to possible changes to its char- acteristics. Consequently, when the time comes to lower the water table, if the groundwater levels are below those used in the hydrodynamic ...Dragoljub Bajić, Dušan Polomčić. "Fuzzy optimization in hydrodynamic analysis of groundwater control systems: Case study of the pumping station “Bezdan 1”, Serbia" in Geološki anali Balkanskoga poluostrva, Belgrade : University of Belgrade - Faculty of mining and geology (2014). https://doi.org/10.2298/GABP1475103B
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Investigation of quantitative indicators of anisotropy based on longitudinal elastic waves propagation velocities with uncertainty
... samples is presented in the Table 1 and Table 2. Table 1 Statistical analysis of the obtained results for isotropic samples Statistical parameter 𝐷𝐼𝑖,𝑚𝑎𝑥 % 𝐷𝐼𝑖,𝑚𝑖𝑛 % 𝐷𝐼𝑗,𝑚𝑎𝑥 % 𝐷𝐼𝑗,𝑚𝑖𝑛 % 𝐾𝐼𝑖,𝑚𝑒𝑎𝑛 % 𝐾𝐼𝑗,𝑚𝑒𝑎𝑛 % Min 2.13 0.13 12.40 13.74 0.26 23.35 ...
... measurements. In: Heritage, weathering and conservation. 2nd ed. London: Taylor and Francis Group plc; pp. 749-756 PETRUŽÁLEK M. et al. (2008) Changes of anisotropy of p-wave velocity propagation during deformation process of rock samples. In: 28-European Conf. AE Testing, Ewgae 2008, Cracow UT ...Miloš Gligorić, Jelena Majstorović, Suzana Lutovac. "Investigation of quantitative indicators of anisotropy based on longitudinal elastic waves propagation velocities with uncertainty" in Underground Mining Engineering, Belgrade : University of Belgrade - Faculty of Mining and Geology (2018). https://doi.org/10.5937/PodRad1832001G
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Production of electricity from coal-fired power plants and accompanying CO2 emissions: comparison of EU-27 and US
Even in the third decade of the 21st century, large power plants are still responsible for more than half of the electricity production in Europe and US. They predominantly use fossil fuels in their work, which results in the emission of pollutants into the air, soil and water. In addition to the production of electric energy, fossil fuels, including coal, are used for industrial purposes. Although the use of coal, especially in the countries of the European Union, is ...... times since the industrial revolution, because of rapid technological progress and exceptional demographic transition [1]. Looking at long-term changes and projections of the possible development of various energy sectors is a vital activity for the sustainable development of states, regions, local ...Uroš Djorgovski, Aleksandar Madžarević, Predrag Jovančić. "Production of electricity from coal-fired power plants and accompanying CO2 emissions: comparison of EU-27 and US" in International Conference on Global Energy and Climate Change - ICGRECC-23, New York, 2023, Research Galery- Science Leagues (2023)
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The influence of alkyl polyglucosides (and highly ethoxylated alcohol boosters) on the phase behavior of a water/toluene/technical alkyl polyethoxylate microemulsion system
Marija Ilic, Franz-Hubert Haegel, Vesna Pavelkic, Dragan Zlatanovic, Snezana Nikolic-Mandic, Aleksandar Lolic, Zoran Nedic (2016)The influence of additives (alkyl polyglucoside, Glucopon 600 CS UP and alcohol ethoxylate C18E100) on the behavior of the water/toluene/Lutensol ON 50 (technical oxoalcohol, i-C10E5) microemulsion system as a function of temperature and composition has been investigated. The phase behavior of the microemulsions was determined by vertical sections through the Gibbs phase prism (fish-like phase diagrams). Alkyl polyglucoside shifts the one phase region to lower temperatures compared with water/toluene/Lutensol ON 50 mixtures. This is contrary to the expectation, considering ...микроемулзија, толуен, алкил полиглукозид, оксоалкохол етоксилат, појачивач ефикасности, „fish“ дијаграми... with the branched technical surfactant needed very long and sometimes extremely long times for equilibration after agitation or temperature changes. They show delayed visible phase separ- ation and the phase boundaries to the two-phase regions determined visually are diverging. Using the ...Marija Ilic, Franz-Hubert Haegel, Vesna Pavelkic, Dragan Zlatanovic, Snezana Nikolic-Mandic, Aleksandar Lolic, Zoran Nedic. "The influence of alkyl polyglucosides (and highly ethoxylated alcohol boosters) on the phase behavior of a water/toluene/technical alkyl polyethoxylate microemulsion system" in Chemical Industry and Chemical Engineering Quarterly, National Library of Serbia (2016). https://doi.org/ 10.2298/CICEQ141105015I