Претрага
752 items
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Crystallography and Surface Oxidation of Stoichiometric Arsenopyrite from Šumadija-Kopaonik Pb-Zn/Polymetallic Ore District (Serbia)
Ivana Jelić, Aleksandar Pačevski, Aleksandar Kremenović, Aleš Šoster, Andreja Šestan, Janez Zavašnik (2023)The behaviour and stability of arsenopyrite largely depend on its crystal structure, but studies of crystallography and structural defects are scarce. For clarification, we investigated a series of natural arsenopyrite crystals from the polymetallic Pb-Zn-(±Cu,Ag,Au,Sb,Bi,W) Šumadija-Kopaonik ore district (Serbia) by powder X-ray diffraction (XRPD). Among them, samples from the Drenjak gold mineralisation showed near-stoichiometric FeAsS composition and were further investigated by conventional and high-resolution transmission electron microscopy methods. TEM revealed abundant planar crystallographic defects and epitaxial surface oxide layer ...Inorganic Chemistry, Condensed Matter Physics,General Materials Science, General Chemical Engineering, crystal structure, FeAsS, oxidation, TEM, XRPD... monoclinic structure, P2/c [9]. The published reports also highlight the possible micro-twinning, and other structural defects as the main obstacle hindering the precise structure analysis, suggesting, additional studies by transmission electron microscopy [10]. The basic investigations Crystals ...
... which contrasts sharply with the available structural data [2,5-7]. The ambiguous structure of arsenopyrite has been analysed since the early days of instrumental crystallography [8] and has continued until present day [9]. Several different structural arrangements have been sug;gested, influenced ...
... patterns, recorded in several different orientations (Table 2). Before analysis, the camera length (L) was calibrated by MAG*ICAL traceable TEM calibration standard to enhance the method”s precision. Quantitative analysis of electron diffraction was calculated according, to Bragg's law nA = 2d ...Ivana Jelić, Aleksandar Pačevski, Aleksandar Kremenović, Aleš Šoster, Andreja Šestan, Janez Zavašnik. "Crystallography and Surface Oxidation of Stoichiometric Arsenopyrite from Šumadija-Kopaonik Pb-Zn/Polymetallic Ore District (Serbia)" in Crystals, MDPI AG (2023). https://doi.org/10.3390/cryst13020278
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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... obtained precipitates was performed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman analysis, differential thermal and thermogravimetric analysis (DTA/TGA), and scanning electron microscopy (SEM). 2. Materials and Methods A total number of 43 bacterial isolates (I1-I3; ...
... 01–072–1652, vaterite: 01–075–9355, and vaterite: 01–075–9356). The chemical bond vibrations during FTIR analysis were recorded in the range of 4000–400 cm–1, using the ATR technique. Additionally, Raman analysis was performed at a range of 100–1500 cm–1 using a DXR Raman microscope (Thermo Scientific, Waltham ...
... licheniformis). According to the structure characterization above, DTA/TGA analysis had shown consistent results (Figure 9). Around 20 mg of each sample was heated to 1000 ◦C, at a rate of 10 ◦C/min. Two stages in the thermal analysis may be noticed, below and above 400 ◦C. Below 400 ◦C three peaks are noticeable ...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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Evaluation of the effects of wastewater heat pump integration into district heating systems by simulation
Dejan Ivezić, Marija Živković, Dimitrije Manić, Aleksandar Madžarević, Boban Pavlović, Dušan Danilović (2023)The integration of wastewater heat pumps (using purified water) in district heating systems is analyzed in this paper. The simulation procedure is proposed to analyze the impacts of stochasticity of purified water temperature and flow to heat pump integration and operation. The analysis includes calculation of the daily and seasonal coefficient of performance, as well as fossil fuel savings and CO2 emission reduction due to wastewater heat pump use. The proposed procedure is implemented for the case study in ...Dejan Ivezić, Marija Živković, Dimitrije Manić, Aleksandar Madžarević, Boban Pavlović, Dušan Danilović. "Evaluation of the effects of wastewater heat pump integration into district heating systems by simulation" in Thermal Science, National Library of Serbia (2023). https://doi.org/10.2298/TSCI220813168I
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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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Evaluation And Perspectives Of Underground Coal Mines In Serbia
... cvjetic@rgf.bg.ac.rs Summary: This paper provides analysis of mines operating in Public Company for Underground Coal Exploitation (PCUCE), which is in restructuring process in excess of 10 years. Evaluation of these mines included analysis of performance and development potential of eight mines ...
... (Headquarters in Resavica). Operation and performances of PCUCE were evaluated and analyzed on several occasions in previous years. Most notable analysis were [2], during which PCUCE was a part of JP EPS, and [3], study financed by European Agency for Reconstruction whose beneficiary was Ministry ...
... Conclusion Public Company for Underground Coal Exploitation operates 8 mines and one company working as a contractor at other mines. AHP analysis, based on technical criteria, identified two groups of mines, one with potential for further development (Soko, Strmosten pit- REMBAS, Lubnica ...Vladimir Milisavljević, Milena Lekić, Ivica Ristović, Vojin Čokorilo, Aleksandar Cvjetić. "Evaluation And Perspectives Of Underground Coal Mines In Serbia" in 7th Balkan Mining Congress Preceedings - BalkanMine2017, Prijedor, 11-13. oktobar 2017., Banjaluka : University of Banjalika, Faculty of Mining, RS, BiH (2017)
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Geostatički proračuni sanacije klizišta šipovima
U ovom radu su, polazeći od rezultata geotehničkih istraživanja, prikazani geostatički proračuni sanacije klizišta vertikalnim šipovima. Metodologija proračuna je složena, jer podrazumeva interakciju klizišta i stabilizirajućih šipova. Stoga se simultano analiziraju stabilnost klizišta i stabilnost šipova. Prilikom određivanja bočne otpornosti tla oko šipova koristi se metoda Brinč Hansena koja uzima u obzir trodimenzionalne uslove u tlu i može da se primeni u složenim geološkim uslovima koji su česti u Srbiji. Analize stabilnosti klizišta vrše se odgovarajućim metodama granične ravnoteže. ...sanacija klizišta, interakcija klizišta i šipa, bočna otpornost šipova, stabilnost klizišta i šipova... complex, because it is based on the interaction between landslide and stability piles. In accordance to that, landslide stability analysis and pile stability analysis are carried out simultaneously.The lateral resistance of piles is calculated by Brinch Hansen method. It includes three-dimensional ...
... trodimenzionalni problem i stabilnosti klizišta. 300 U radu su prikazani svi elementi koji predloženu m LITERATURA: Chandler, R.J.: Back analysis techniques for slope stabilization works: a case record. Geotechnique Vol. 27, No. 4, 1977, pp. 479-495. asopis Izgradnja i Srpsko društvo za mehaniku ...
... Tuzla, 2000. NAVFAC, Design Manual DM -7.1., Soil mechanics, Department of the Navy, Alexandria, 1982. Poulos, H. G. and Davis, E. H.: Pile foundation analysis and design, John Wiley & Sons, New York, 1980. Tomlinson, M. J.: Foundation design and construction, The Pitman book, London, 1980. View publication ...Slobodan Ćorić, Dragoslav Rakić, Dušan Berisavljević. "Geostatički proračuni sanacije klizišta šipovima" in Zbornik radova osmog naučno-stručnog međunarodnog savetovanja - Geotehnički aspekti građevinarstva, Savez građevinskih inženjera Srbije, (2019)
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Novi pristup proučavanju tekstura minerala značajnih za istraživanje rudnih ležišta
Aleksandar Pačevski (2022)... Ag in this pyrite were determined by the microprobe analysis methods of a mineral composition (EMPA and LA-ICP-MS). However, using the microprobe analysis methods of a crystal structure of mineral, such as micro-Raman spectroscopy and TEM analysis with prior sample preparation by Focused Ion Beam (FIB) ...
... determination: trends and achievements Miloš Marjanović, Analiza odrona u stenskim kosinama: savremeni pristupi Miloš Marjanović, Rockfalls analysis in rock slopes: state-of-the-art approaches Aleksandar Pačevski, Novi pristup proučavanju tekstura minerala značajnih za istraživanje rudnih ležišta ...
... Ramdohr (1890-1985) to this development should certainly be emphasized. In last decades, the development of many sophisticated methods of microprobe analysis (in-situ) has enabled a further shift in the study of minerals and their textures to nanometer and even atomic levels, which certainly offers great ...Aleksandar Pačevski. "Novi pristup proučavanju tekstura minerala značajnih za istraživanje rudnih ležišta" in 18. Kongres geologa Srbije “Geologija rešava probleme” Divčibare, 01-04 jun 2022., Beograd : Srpsko geološko društvo (2022)
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Application of machine learning for diagnosing the operation of a deep well pump in oil production
Maja Trikić (2024)This paper will thoroughly examine how machine learning can improve the diagnosis of deep well pumps by analyzing the role and function of the pumps, dynamograms, sensor technologies, and diagnostic methods.Our analysis will provide insights into modern techniques and approaches for enhancing the performance and reliability of oil production systems, targeting cost reduction and increased operational efficiency.deep well pump, dynamograms, machine learning, diagnostics of operating coditions,Random Forest, XGBoost... SYSTEMS 3.1 Explanation of dynamograms in oil production The basis for diagnosing issues in downhole pump operation is the analysis of dynamogram shapes. This analysis uses theoretical, surface, and downhole dynamograms. By comparing the shapes of dynamograms obtained from measured data with ...
... more maintainable program and is often more accurate in identifying spam. 18 Ready for Use () problem ng Evaluation ol analysis i Solutions (5 error analysis Figure 4.2 Machine learning approach If spammers notice that your filter blocks messages containing the word "Your" in the ...
... Fourier Transform, moment analysis, and other techniques to recognize key patterns in the data. These descriptors allow conversion of complex data into a format that is easier to analyze and interpret. 51 5.Use in Diagnostics: Extracted features are used for further analysis to identify potential ...Maja Trikić. Application of machine learning for diagnosing the operation of a deep well pump in oil production, 2024
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Selection of Artificial Lift Methods: A Brief Review and New Model Based on Fuzzy Logic
Miroslav Crnogorac, Miloš Tanasijević, Dušan Danilović, Vesna Karović Maričić, Branko Leković (2020)Artificial lift methods have applications in oil wells where oil production is no longer possible due to natural reservoir energy, so this necessary energy is added by introducing lift methods. In order to achieve optimum production, the selection of an artificial lift method is very important. This paper uses fuzzy logic as a mathematical and conceptual model for selection of the optimal artificial lift method. The outcome or IF-THEN rules, as the central part of the model, is based ...... of multicriteria analysis: TOPSIS, ELECTRE, SAW and VIKOR, in the case of oil fields in Iran. The authors used multiple sets of input data: restrictions on production, deposits and wells; characteristics of production fluid, and surface infrastructure. Cross-Sectional Analysis of Presented Research ...
... created by applying multi-criteria analysis (TOPSIS, ELECTRE, SAW and VIKOR). Based on the known parameters, the expert gives estimates of the input data for the optimization model, and the output is the most suitable artificial lift method [11–14]. The analysis of the mathematical and conceptual ...
... Electric motor Multi-cylinder or electric Compressor Gas or electric Energies 2020, 13, 1758 6 of 15 3.1. Analysis of the Input Parameters In the part of the model relating to analysis, the most important step is the fuzzy proposition. This is a procedure for representing a statement that includes ...Miroslav Crnogorac, Miloš Tanasijević, Dušan Danilović, Vesna Karović Maričić, Branko Leković. "Selection of Artificial Lift Methods: A Brief Review and New Model Based on Fuzzy Logic" in Energies, MDPI AG (2020)
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Prilog poznavanju režima i bilansa voda reke Resave
Sliv Resave zauzima područje između reke Velike Morave i obronaka Kučajsko-beljaničkih planina. Sliv i režim ove reke kontroliše se dvema hidrološkim stanicama: Manastir Manasija (slivno područje u iznosu od 388 km2) i Svilajnac (681 km2). Za potrebe analize režima voda reke Resave i uticaja padavina na formiranje oticaja sa njenog sliva preuzeti su podaci o padavinama sa meteorološke stanice Crni Vrh (1037 m nm) koji odslikava režim gornjeg dela sliva ove reke, i meteorološke stanice Smederevska ...Marina Mitrašinović, Vesna Ristić Vakanjac, Saša Milanović, Ljiljana Vasić, Dušan Polomčić. "Prilog poznavanju režima i bilansa voda reke Resave" in Zbornik radova XVI Srpski hidrogeološki simpozijum sa međunarodnim učešćem, Zlatibor, 2022., Univerzitet u Beogradu, Rudarsko-geološki fakultet (2022)
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Assessment of the Geotouristic Values of Devil’s Town, Serbia
Danijela Vukoičić, Danica Srećković-Batoćanin, Aleksandar Valjarević, Dušan Ristić, Milena Nikolić, Dragana Valjarević (2021)Geotouriyam, Geonasledje, M-GAM, Komparativna analiya, Đavolja Varoš, Peščane piramide, Stob Piramide, Melnik piramide, SrbijaDanijela Vukoičić, Danica Srećković-Batoćanin, Aleksandar Valjarević, Dušan Ristić, Milena Nikolić, Dragana Valjarević. "Assessment of the Geotouristic Values of Devil’s Town, Serbia" in Geologia Croatica, Croatian Geological Survey (2021). https://doi.org/10.4154/gc.2021.11
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The efficiency of chemical cleaning of different metal artefacts from Felix Romuliana and Gradina archaeological sites (Serbia)
Slobodan Bogojević, Kristina Šarić, Bojan Kostić, Suzana Erić. "The efficiency of chemical cleaning of different metal artefacts from Felix Romuliana and Gradina archaeological sites (Serbia)" in Archaeology and science, Beograd : Center for New Technology Viminacium Institute of Archaeology Belgrade (2022)
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Hybrid Stochastic-Grey Model to Forecast the Behavior of Metal Price in the Mining Industry
Zoran Gligorić, Miloš Gligorić, Dževdet Halilović, Čedomir Beljić, Katarina Urošević. "Hybrid Stochastic-Grey Model to Forecast the Behavior of Metal Price in the Mining Industry" in Sustainability (2020). https://doi.org/10.3390/su12166533
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Extensive vibrations of the belt conveyer drive electromotor of a bucket wheel excavator as a result of intesified wear-and-tear of its mount support
Vesna Damnjanović, Predrag Jovančić, Snežana Aleksandrović. "Extensive vibrations of the belt conveyer drive electromotor of a bucket wheel excavator as a result of intesified wear-and-tear of its mount support" in Journal of Vibroengineering (2017). https://doi.org/10.21595/jve.2016.17321
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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... 725-739. DOI: 10.2298/JSC120716125I [4] SRPS B.H8.359. Methods of analysis of coal and coke - Determination of chemical composition of fuel ash - General requirements. // Belgrade (1973). [5] SRPS B.H8.360. Methods of analysis of coal and coke - Determination of silica (SiO2) in ash from solid ...
... solid fuels. // Belgrade (1973). [6] SRPS B.H8.361. Methods of analysis of coal and coke - Determination of barium oxide (BaO) in ash from solid fuels. // Belgrade (1973). [7] SRPS B.H8.362. Methods of analysis of coal and coke - Determination of ferric oxide (Fe2O3) in ash from solid fuels. // ...
... // Belgrade (1973). [8] SRPS B.H8.363. Methods of analysis of coal and coke - Determination of titanium oxide (TiO2) in ash from solid fuels. // Belgrade (1973). [9] SRPS B.H8.364. Methods of analysis of coal and coke- Determination of aluminum oxide (Al2O3) in ash from solid fuels. // Belgrade ...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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Sinteza i karakterizacija nanoprahova u CeO2-Bi2O3 sistemu
Marija D. Prekajski (2014-04-04)Nanoprahovi kristalnih faza iz serije čvrstih rastvora u pseudo-binarnom sistemuCeO2-Bi2O3 sintetisani su primenom jednostavne i ekonomične samopropagirajućemetode na sobnoj temperaturi korišćenjem nitrata metala i natrijum-hidroksida kaopolaznih supstanci. Osim krajnjih članova niza, CeO2 i niskotemperaturne polimorfnemodifikacije α-Bi2O3, sintetisani su i čvrsti rastvori nominalnog sastava Ce1-xBixO2-δ,gde je x = 0,1; 0,2; 0,3; 0,4; 0,5; 0,6; 0,7; 0,8; 0,9. Rezultati proučavanja metodomrendgenske difraktometrije na polikristalnom materijalu i ramanske spektroskopskeanalize pokazali su da su sintetisani prahovi sa nižim sadržajem bizmuta (x = 0,1 ...nanostrukturni materijali, čvrsti rastvori, CeO2, Bi2O3, rendgenskadifraktometrija praha, Ritveldova metoda, mikrostrukrurna analizaMarija D. Prekajski. "Sinteza i karakterizacija nanoprahova u CeO2-Bi2O3 sistemu" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2014-04-04)
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Application of geophysical and multispectral imagery data for predictive mapping of a complex geo-tectonic unit: a case study of the East Vardar Ophiolite Zone, North-Macedonia
... highest among all models. @ Springer In addition to the statistical examination of evaluation metrics, an equally significant analysis pertains to the visual analysis of classification maps, i.e., predictive maps. The predictive maps of the chosen models for all three datasets are illustrated ...
... suitable class balance for the training dataset is a critical factor in achieving accurate ophiolite prediction with RF and KNN algorithms. The analysis of feature importance revealed that the Bouguer gravity anomaly map, total intensity of the Earth's magnetic field reduced to the pole map, distance ...
... fea- tures for predicting ophiolites within the EVZ. KNN showed poorer results compared to RF in terms of both the evaluation metrics and visual analysis of prediction maps. The methods applied in this research can be applied for predictive mapping of complex geo-tectonic units covered by dense vegetation ...Filip Arnaut, Dragana Đurić, Uroš Đurić, Mileva Samardžić-Petrović, Igor Peshevski. "Application of geophysical and multispectral imagery data for predictive mapping of a complex geo-tectonic unit: a case study of the East Vardar Ophiolite Zone, North-Macedonia" in Earth Science Informatics, Springer Science and Business Media LLC (2024). https://doi.org/10.1007/s12145-024-01243-4
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New insights into tectonic relations between the Eastern Vardar Ophiolitic and Serbo-Macedonian units: Inferences from a microtectonic study in central Serbia
Maja Maleš, Nikola Ranđelović, Nemanja Krstekanić, Bojan Kostić, Nikolina Ćirić, Uroš Stojadinović (2023)Источно-вардарски офиолити, Српско-македонска јединица, микротектонска анализа, каснојурска обдукција, пост-обдукционе деформацијеMaja Maleš, Nikola Ranđelović, Nemanja Krstekanić, Bojan Kostić, Nikolina Ćirić, Uroš Stojadinović. "New insights into tectonic relations between the Eastern Vardar Ophiolitic and Serbo-Macedonian units: Inferences from a microtectonic study in central Serbia" in Geološki anali Balkanskoga poluostrva (2023). https://doi.org/10.2298/GABP230130002M
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Аутоматска екстракција дефиниција – допринос убрзању израде речника
дескриптивни речници, метаанализа лексикографских дефиниција, аутоматска екстракција дефиниција, електронски речници, српски језикРада Стијовић, Цветана Крстев, Ранка Станковић. "Аутоматска екстракција дефиниција – допринос убрзању израде речника" in Лексикологија и лексикографија у светлу актуелних проблема, Институт за српски језик САНУ (2021)
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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)