Претрага
270 items
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Water in the Alluaudite Type-Compounds: Synthesis, Crystal Structure and Magnetic Properties of Co3(AsO4)0.5+x(HAsO4)2−x(H2AsO4)0.5+x[(H,□)0.5(H2O,H3O)0.5]2x+
In this study, a new cobalt arsenate belonging to the alluaudite supergroup compounds with the general formula of Co3(AsO4)0.5+x(HAsO4)2−x(H2AsO4)0.5+x[(H, )0.5(H2O,H3O)0.5]2x+ (denoted as CoAsAllu) was synthesized under hydrothermal conditions. Its crystal structure was determined by a room-temperature single-crystal X-ray diffraction analysis: space group C2/c, a = 11.6978(8), b = 12.5713(7), c = 6.7705(5) Å, b = 113.255(5)◦, V = 914.76(11) Å3, Z = 2 for As6H8Co6O25. It represents a new member of alluaudite-like protonated arsenates and the first alluaudite-like phase ...супергрупа алуаудита, арсенати прелазних метала, хидротермална синтеза, кристална структура, хидратисани хидрокси-арсенати, стехиометрија, магнетна својстваTamara Đorđević, Ljiljana Karanović, Marko Jagodič, Zvonko Jagličić. "Water in the Alluaudite Type-Compounds: Synthesis, Crystal Structure and Magnetic Properties of Co3(AsO4)0.5+x(HAsO4)2−x(H2AsO4)0.5+x[(H,□)0.5(H2O,H3O)0.5]2x+" in Minerals, MDPI AG (2021). https://doi.org/10.3390/min11121372
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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 ...... 3390/en13071758 www.mdpi.com/journal/energies Energies 2020, 13, 1758 2 of 15 unit search—OPUS, Sistema Experto de Levantamiento Artificial—SEDLA). Decision-making methods, such as the decision tree and the most recent multi-criteria analysis (Technique for Order Preference by Similarity to Ideal So ...
... VLR <0.1 Surface Infrastructure location offshore electrical power utility well service pulling unit Selection of mentioned method was done using an optimization model based on a multi-criteria analysis, specifically using the ELECTRE method [12]. The exploitation methods for application ...
... define a synthetic estimate. In this type of selection of the optimal artificial lift method, approaches based on the model of multiatributive and multi-criteria analyses are used, as well as those based on statistical data processing from engineering practice and expert systems. The selection of ...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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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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Bilingual lexical extraction based on word alignment for improving corpus search
Jelena Andonovski, Branislava Šandrih, Olivera Kitanović. "Bilingual lexical extraction based on word alignment for improving corpus search" in The Electronic Library, Emerald (2019). https://doi.org/10.1108/EL-03-2019-0056
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Punctuated, episodic magmatism and mineralization of the Rogozna skarn-hosted Au-Zn-Pb-Cu deposits revealed through high-precision U-Pb zircon geochronology
The subvolcanic regions of magmatic centers are commonly associated with alteration, mineralization, and economic ore deposits, however the duration and frequency of mineralizing pulses within the overall lifespan of these centers can be poorly defined. Therefore, models for the formation of mineral systems require more highprecision geochronology data to refine their evolutionary models. Rogozna Mountain and its eponymous magmatic complex, located in SW Serbia, hosts multiple base metal deposits associated with variable rock types and structural expressions and serves as a natural laboratory to ...Skarnovska mineralizacija, Magmatsko-hidrothermalni sistemi, Subvulcanske intruzije, geohronologija na cirkonima, CA-ID-TIMSSean P. Gaynor, Milorad D. Antić, Vladica Cvetković, Kristina Šarić, Urs Schaltegger. "Punctuated, episodic magmatism and mineralization of the Rogozna skarn-hosted Au-Zn-Pb-Cu deposits revealed through high-precision U-Pb zircon geochronology" in Ore Geology Reviews, Elsevier (2023). https://doi.org/https://doi.org/10.1016/j.oregeorev.2023.105775
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Effectiveness Analysis of Different Bucket-wheel Excavators
Coal production in open-pit lignite mines in the Republic of Serbia is performed with continuous work systems. In addition to coal production, the same systems are used for the exploitation of large quantities of overburden. According to the reliability concept, continuous systems are in linear connection. If the failure occurs in one part of the system, that will produce a downtime of the entire system. The initial and most important factor of continuous systems is the bucket-wheel excavator. It ...Stevan Đenadić, Predrag Jovančić, Dragan Ignjatović, Miloš Tanasijević, Filip Miletić. "Effectiveness Analysis of Different Bucket-wheel Excavators" in 8th International Conference Mining and Environmental Protection, Sokobanja, 22-25 September 2021, University of Belgrade, Faculty of Mining and Geology, Belgrade, Serbia (2021)
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Hypogene speleogenesis related to porphyry magmatic intrusions and its influence on subsequent karst evolution in the Peruvian high Andes
Alexander Klimchouk, David Evans, Sasa Milanovic, Cristian Bittencourt, Mauro Sanchez, F. Carlos Aguirre (2022)Alexander Klimchouk, David Evans, Sasa Milanovic, Cristian Bittencourt, Mauro Sanchez, F. Carlos Aguirre. "Hypogene speleogenesis related to porphyry magmatic intrusions and its influence on subsequent karst evolution in the Peruvian high Andes" in Geomorphology, Elsevier BV (2022). https://doi.org/10.1016/j.geomorph.2022.108488
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Značaj izvodjenja Proktorovog opita na komunalnom otpadu
Komunalni otpad predstavlja jedan od ključnih problema današnjice. U Srbiji je najčešći vid odlaganja otpada na komunalne deponije i zbog toga je bitno ispravno i sigurno ga skladištiti. Zbijanje komunalnog otpada predstavlja jednu od osnovnih komponenti procesa odlaganja. Kako bi se što bolje predvidelo ponašanje komunalnog otpada neophodno je pre zbijanja na terenu laboratorijski odrediti maksimalnu suvu zapreminsku težinu i optimalnu vlažnost. U dosadašnjoj praksi u svetu za to se koristi standardizovan Proktorov opit. U radu će biti prikazani ...... basic components of the disposal process. In order to better predict the behaviour of municipal waste, it is necessary to determine the maximum dry unit weight and optimal moisture content before compaction in the terrain, for which Standard Proctor test has been used in the world current practice ...Jovana Janković, Dragoslav Rakić, Tina Đurić, Irena Basarić Ikodinović, Laslo Čaki. "Značaj izvodjenja Proktorovog opita na komunalnom otpadu" in Zbornik radova osmog naučno-stručnog međunarodnog savetovanja - Geotehnički aspekti građevinarstva, Savez građevinskih inženjera Srbije (2019)
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Effects of Energy Production and Consumption on Air Pollution in Serbia
Marija Živković (2019)Energy production and combustion, mostly from unregulated or inefficient fuel combustion, are the single most important anthropogenic sources of air pollutant emissions. Energy sector in Serbia is highly fossil fuel intensive: 87.88% of energy consumed in Serbia is related to fossil fuels, while almost 95% of energy sources are combusted. In 2017. energy related carbon dioxide emission in Serbia is was 47.95 million tones. The main source of carbon dioxide emission was coal, responsible for almost 70% of energy ...... is no single level of emissions per unit of a specific fuel (emission factor) but, rather, a range of emission factors depending on such variables 4. Specific fuels play a key role in relation to certain types of air pollution, both in terms of emissions per unit of fuel consumed and in terms of their ...
... in wider context (Table 1) 10. Among presented countries Serbia has the highest value of TPES/GDP which indicates the highest energy consumption per unit of produced value and energy intensive industry. In the case of Germany the highest value of emission per capita indicates higher energy consumption ...Marija Živković. "Effects of Energy Production and Consumption on Air Pollution in Serbia" in Mining and Environmental Protection-MEP 2019, University of Belgrade, Faculty of Mining and Geology (2019)
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Paleomagnetic evidence for post-collisional Miocene clockwise rotation in the Serbian segment of the Vardar Zone and the Danubicum
Vesna Lesić, Emő Márton, Vesna Cvetkov, Dragana Tomić. "Paleomagnetic evidence for post-collisional Miocene clockwise rotation in the Serbian segment of the Vardar Zone and the Danubicum" in 26th IUGG General Assembly Prague, Czech Republic, International Union of Geodesy and Geophysics (2015)
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New data from the Lower Cretaceous carbonate platform deposits of Dimitrovgrad section (Southeastern Serbia)
... facies analyses, limestones, Getic, Serbia, carbonate platform. Lower Cretaceous carbonate platforms record distinctive facies in the area of Getic unit defined Beriasian, Valanginian, Hauterivian and Urgonian like facies. These deposits result from the continuous trend of shallow- water sedimentation ...Jelena Stefanović, Bojana Džinić, Giovanna Della Porta, Dejan Radivojević. "New data from the Lower Cretaceous carbonate platform deposits of Dimitrovgrad section (Southeastern Serbia)" in 90° Congresso della Società Geologica Italiana, Trieste, 14-16 septembar, 2021, Società Geologica Italiana (2021)
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Anisotropic grossular–andradite garnets: Evidence of two stage skarn evolution from Rudnik, Central Serbia
This paper presents LA-ICP-MS data for garnets from the Rudnik skarn deposit (Serbia), which range from Grs45–58Adr40–52Alm2–3 in the core and Adr70–97Grs2–29Sps1 in the rim displaying anisotropy and zoning. In spite of wide compositional variations the garnets near the end-member of andradite (Adr > 90) are generally isotropic. Fe-rich rims exhibit LREE depletion and flat HREE pattern with weak negative Eu anomaly, including higher As and W contents. On the other side, the Fe-poorer core shows flat REE pattern ...... or less terrigenous component. The carbonate unit is not of con- stant thickness in respect to the clastic ones, which are closer to the surface. Marlstones, almost pure limestones and transi- tional varieties were recognized within the carbonate unit, depending on the amount of clastic component ...
... al. 2008; Cvetković et al. 2016; Prelević et al. 2017). The Sava Zone (suture zone) separates the Carpatho–Balkan orogen (a part of the Dacia Mega-unit and Tisza), from the southerly and wes- terly Adria derived thrust sheets, namely the Dinarides (Pamić & Šparica 1983; Haas & Péró 2004). Trending ...
... Cr2O3 n.d. n.d. 0.01 0.03 Total 100.76 98.76 98.68 100.63 n.d. – not detected Garnet formula calculated on the basis of 12 oxygen atoms per formula unit (apfu) Si 2.991 2.962 3.012 3.015 Al 0.009 0.038 0.000 0.000 Sum 3.000 3.000 3.012 3.015 Al 1.198 0.588 0.961 0.060 Ti 0.000 0.041 0.000 0.012 Fe3+ ...Bojan Kostić, Danica Srećković-Batoćanin, Petyo Filipov, Pavle Tančić, Kristijan Sokol. "Anisotropic grossular–andradite garnets: Evidence of two stage skarn evolution from Rudnik, Central Serbia" in Geologica Carpathica, Central Library of the Slovak Academy of Sciences (2021). https://doi.org/10.31577/GeolCarp.72.1.2
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English for Geology Students. 1
Lidija Beko (2023)... Geological Wonders ... a 37 Profession – Mineralogist ............ii ... 38 Geology Mystery Files ... 39 Geology through Myths..............c. 42 • Unit 2 • FOSSILS THROUGH TIMES Partl FOSSILS THROUGH TIMES.............ta a 46 Vocabulary...........aa a ı 48 Reading Comprehension........... . ...
... Geology Mystery Files ... - 68 Geology through Myths..............a. 72 Part 1 Part 2 Part 3 Part 1 Part 2 Part 3 Table of contents • Unit 3 • TIME AND AGE – GEOLOGICAL THEORIES THROUGH TIMES CATASTROPHE OR UNIFORMITY?......... o 76 Vocabularyef.o.. ... . BOR e ake e v e u aR + 40 ...Lidija Beko. English for Geology Students. 1, Belgrade : The Faculty of Mining and Geology, 2023
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Polyhedral characteristics of the cosalite-type crystal structures
Sabina Kovač, Predrag Dabić, Aleksandar Kremenović, Aleksandar Pačevski, Ljiljana Karanović, Marko V. Rodić, Martina Tribus (2019)Sabina Kovač, Predrag Dabić, Aleksandar Kremenović, Aleksandar Pačevski, Ljiljana Karanović, Marko V. Rodić, Martina Tribus. "Polyhedral characteristics of the cosalite-type crystal structures" in The Canadian Mineralogist, Mineralogical Association of Canada (2019). https://doi.org/10.3749/canmin.1900017
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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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Kristalne strukture Cs2HoSi4O10F i Cs2TmSi4O10F
... X-ray diffraction analysis. They represent mutually isostructural compounds which crystallize in the orthorhombic space group Pnma with following unit cell parameters: a = 22.3809 (7), b = 8.8686 (3), c = 11.9827 (4) V = 2378.41 (14) 3, Z = 8 (for Cs2HoSi4O10F compound), a = 22.3447 (5), b = 8.8131 ...Predrag Dabić, Sabina Kovač, Aleksandar Kremenović. "Kristalne strukture Cs2HoSi4O10F i Cs2TmSi4O10F" in XXVII konferencija Srpskog kristalografskog društva, Kragujevac, 16-17. septembar 2021., Beograd : Srpsko kristalografsko društvo (2021)
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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. ...... Avala belongs to the Avala-Orešac structural unit characterized by blocky structure (MAROVIĆ & KNEŽEVIĆ, 1985; MAROVIĆ et al., 2007). According to MAROVIĆ & KNEŽEVIĆ (1985), TOLJIĆ (1996, 2016) and MAROVIĆ et al. (2007), the Avala-Orešac structural unit was dissected into smaller blocks by systems ...
... (2013) these clastites represent the final phase of pre-Badenian lacustrine sedimentation (Fig. 3c, d). At the same time, in this study, a similar unit was observed in boreholes BT1-2 and BT1-3 near Leštane. During exploratory drilling for the construction of the “Bubanj Potok” railway tunnel, it ...
... has a large spatial distribution and underlies the younger Miocene rocks. Unlike the overlying marine Badenian gravel, conglomerates and sands, this unit does not contain fossils and has a different colour and petrological content (DOLIĆ, 1997, 1998; RUNDIĆ et al., 2013). 4.1.2. The Middle Miocene ...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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Improving efficiency of thermal power plants through mine coal quality planning and control
Главни циљ контроле квалитета угља у рудницима лигнита је снабдевање термоелектрана угљем чији квалитет мора да се креће унутар одређених квалитативних ограничења. Карактеристике угља могу да утичу на ефикасност, поузданост и расположивост како котла тако и јединица за контролу емисије. У овом раду аутори су презентовали интегрисану симулацију рударског процеса као нови приступ у истраживању променљивости калоричне вредности угља приликом експлоатације комплексног лежишта лигнита. Резултати таквог приступа омогућавају драгоцен увид у перформансе континуалног рударског система у смислу контроле променљивости ...Mirjana Banković, Dejan Stevanović, Milica Pešić, Aleksandra Tomašević, Ljiljana Kolonja. "Improving efficiency of thermal power plants through mine coal quality planning and control" in Thermal Science, Vinča Institute of Nuclear Sciences (2018). https://doi.org/10.2298/TSCI170605209B
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On the distribution modulo 1 of the sum of powers of a Salem number
Dragan Stankov (2016)It is well known that the sequence of powers of a Salem number θ, modulo 1, is dense in the unit interval, but is not uniformly distributed. Generalizing a result of Dupain, we determine, explicitly, the repartition function of the sequence , where P is a polynomial with integer coefficients and θ is quartic. Also, we consider some examples to illustrate the method of determination.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. "On the distribution modulo 1 of the sum of powers of a Salem number" in Comptes rendus Mathematique (2016). https://doi.org/10.1016/j.crma.2016.03.012
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Analysis and Calculation of MMRS and Primary Gas Distribution Network in Urban Environment – Case Study Kučevo
Aleksandar Madžarević, Pavle Janković (2022)Oblast primene prirodnog gasa je veoma široka. Kao energent može se koristiti za proizvodnju energije u elektranama, toplanama i postrojenjima za kombinovanu proizvodnju energije ili za zadovoljavanje različitih toplotnih potreba u industriji i širokoj potrošnji. Gas se može upotrebiti i kao sirovina u hemijskoj i petrohemijskoj industriji, a tokom poslednjih decenija nalazi primenu i u saobraćaju kao pogonsko gorivo u SUS motorima. Sa ekološkog stanovišta, prirodni gas predstavlja najprihvatljiviji izvor energije u poređenju sa drugim fosilnim gorivima. Pri sagorevanju ...Aleksandar Madžarević, Pavle Janković. "Analysis and Calculation of MMRS and Primary Gas Distribution Network in Urban Environment – Case Study Kučevo" in Međunarodni Kongres o procesnoj industriji - PROCESING '22, Beograd : SMEITS, Društvo za procesnu tehniku (2022)