Претрага
2747 items
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Low-temperature phase transition and magnetic properties of K3YbSi2O7
Predrag Dabić, Volker Kahlenberg, Biljana Krüger, Marko Rodić, Sabina Kovač, Jovan Blanuša, Zvonko Jagličić, Ljiljana Karanović, Václav Petříček, Aleksandar Kremenović (2021)alkalni silikati elemenata retkih zemalja, fazni prelazi, magnetne karakteristike, razdvajanje kristalnog polja, silikati lantanica... magnetic properties of K3YbSi2O7 was examined. 2. Experimental 2.1. Synthesis and crystallization of K3YbSi2O7 Single crystals were obtained during a high-temperature flux synthesis experiment using 0.0942 g of a nutrient consisting of a mixture of Yb2O3 (Sigma-Aldrich, 99.99%) and SiO2 (Merck, ...
... magnetic properties of K;YbSi,0O7 was examined. 2. Experimental 2.1. Synthesis and crystallization of K;YbSi,O7 Single crystals were obtained during a high-temperature flux synthesis experiment using 0.0942¢ of a nutrient consisting of a mixture of Yb,O3 (Sigma-Aldrich, 99.99%) and SiO, (Merck, p.a.) in ...
... no apparent influence of the phase transformation on its magnetic properties. Analysis of the magnetization data revealed the positions of the three lowest crystal field levels of the Yb3+ cations, as well as the corresponding projections of their angular momentum on the direction of the magnetic ...Predrag Dabić, Volker Kahlenberg, Biljana Krüger, Marko Rodić, Sabina Kovač, Jovan Blanuša, Zvonko Jagličić, Ljiljana Karanović, Václav Petříček, Aleksandar Kremenović. "Low-temperature phase transition and magnetic properties of K3YbSi2O7" in Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials, International Union of Crystallography (IUCr) (2021). https://doi.org/10.1107/S2052520621006077
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An oilfield in Libya: A new model to enhance waste water disposal
Dušan Danilović, Vesna Karović Maričić, Nori Elhaddad, Branko Leković. "An oilfield in Libya: A new model to enhance waste water disposal" in Energy & Environment (2016)
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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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Assessments of effects of implementation of strategic plans for development of Belgrade District heating system
The district heating system (DHS) is one of the key elements of the Belgrade energy system. Overview of the current state and basic characteristics of the DHS are presented in this paper. The focus is on the planned development of DHS and on the analyses of effects of realization of measures and projects defined by strategic documents related to DHS which are adopted by city authorities (Development Strategy of DHS and Strategy of Belgrade Development). Two exploratory scenarios were ...Dejan Ivezić, Marija Živković, Aleksandar Madžarević, Miodrag Grujić. "Assessments of effects of implementation of strategic plans for development of Belgrade District heating system" in Sustainable Cities and Society, Elsevier BV (2020). https://doi.org/10.1016/j.scs.2020.102304
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Geoenvironmental Investigations at a Smelter Location in Bor (Serbia)
Petar Papić, Zvonimir Milijić, Jana Stojković, Jovana Milosavljević, Maja Todorović, Marina Ćuk, Željko Kamberović (2014)Petar Papić, Zvonimir Milijić, Jana Stojković, Jovana Milosavljević, Maja Todorović, Marina Ćuk, Željko Kamberović. "Geoenvironmental Investigations at a Smelter Location in Bor (Serbia)" in Challenges : Sustainable Land Management – Climate Change, Advances in Geoecology 43, Catena Verlag GMBH (2014)
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Influence of DEM resolution on numerical modelling of debris flows in RAMMS - Selanac case study
Debris flows induced by intensive rainfall represent very hazardous phenomena in many parts of the World. Methods for prediction of runout distance of flow like mass movements are different and depending on the input data, rheology, and available or appropriate numerical solution. However, sometimes it is not easy to obtain pre event and post event high-resolution data in the rural or mountainous area. Thus, the topology of terrain is the most important input parameter for the every real case ...... Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs Influence of DEM resolution on numerical modelling of debris flows ...
... 2023-10-14 04:19:41 Influence of DEM resolution on numerical modelling of debris flows in RAMMS - Selanac case study Jelka Krušić, Biljana Abolmasov, Mileva Samardžić Petrović Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Influence of DEM resolution on numerical ...
... results (Krušić et al, 2018). The influence of topology resolution data on erosion/deposition model was also tested. Figure 4a) Calculation of deference in topography before and after the activation of the debris flow, b) Pleiades image after the event and position of defined release area Source ...Jelka Krušić, Biljana Abolmasov, Mileva Samardžić Petrović. "Influence of DEM resolution on numerical modelling of debris flows in RAMMS - Selanac case study" in 4th Regional Symposium on Landslides in the Adriatic Balkan Region, 23-25 October 2019, Sarajevo, Bosnia and Herzegovina, Geotechnical Society of Bosnia and Herzegovina (2019). https://doi.org/ 10.35123/ReSyLAB_2019
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A necessary and sufficient condition for an algebraic integer to be a Salem number
Dragan Stankov (2019)We present a necessary and sufficient condition for a root greater than unity of a monic reciprocal polynomial of an even degree at least four, with integer coefficients, to be a Salem number. This condition requires that the minimal polynomial of some power of the algebraic integer has a linear coefficient that is relatively large. We also determine the probability that an arbitrary power of a Salem number, of certain small degrees, satisfies this condition.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. "A necessary and sufficient condition for an algebraic integer to be a Salem number" in Journal de theorie des nombres de Bordeaux (2019). https://doi.org/10.5802/jtnb.1076
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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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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 ...... rules. An example of such a method is CalcEstimateVN which estimates the state of the ventilation network on basis of several parameters and their mutual relationships /Fig. 7/. Figure 7. The CalcEstimateVN Method Since all rules in the system do not have to be related to particular objects ...
... Diagonals class, namely the ratio of the number of diagonals to the total number of branches. Figure 6. The Diagonals:Delta Slot Besides the usual slot facets such as type, min- max value and cardinality the slot features a call for a specific method (Calculate Delta) which will be activated ...
... CalculateDelta method will be activated if at any point the value of the slot is required and the slot is empty (with no value assigned). It has already been mentioned that methods in KAPPA-PC can also describe more complex knowledge within the object which takes the form of IF-THEN rules ...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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Analysis of a simplified model for determining rock mass oscillation velocity at the Kovilovača open pit
... parameters by applying the least square method. The Least Square Method is mainly used to obtain the parameters K and n which represents a common model. Model 2 — Determining the parameters through the application of quotient of products of the same number of reduced distances and oscillation velocities ...
... oscillation and oscillation of construction objects [1-3]. Parameter for estimating of the seismic action of blasting, that is commonly used, represents the rock mass oscillation velocity. As the relation between rock mass oscillation velocity and the basic parameters that influence its magnitude, most ...
... velocity equation defines velocity alteration of rock mass oscillation depending on distance, explosive amount, properties of rock material and blasting method. The equation, defined in this way, offers the possibility to determine the seismic effect of blasting towards a structure, whereby the connection ...Suzana Lutovac, Miloš Gligorić, Jelena Majstorović, Luka Crnogorac. "Analysis of a simplified model for determining rock mass oscillation velocity at the Kovilovača open pit" in 9th International Conference Mining and Environmental protection MEP, 24 – 27 May 2023, Sokobanja, Serbia, Belgrade : University of Belgrade-Faculty of mining and geology (2023)
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Numerical modeling of Selanac debris flow propagation using SPH code
The Selanac debris flow is a very huge event triggered after extreme rainfall caused by Cyclone Tamara activity in the Republic of Serbia in May 2014. The Selanac case study was already modelling in different programs using Voellmy rheology assumptions like RAMMS software. In this paper research are focusing particularly on the process of debris flowing from initiation zone to main deposition area using Geoflow SPH two-phase model considering frictional rheology law. Main rheological parameters are back-calculated using also ...... smoothing length of the domain of influence. This mesh-less method makes SPH well adapted to modelling problems involving large deformations and free surface problems, as the complex re- meshing process is avoided. The SPH model proposed by Pastor et al. (2009), defines propagations of mass as mixture ...
... ović, M. (2019).‘’Influence of DEM resolution on numerical modelling of debris flows in RAMMS - Selanac case study’’, Proceeding of the 4th Regional Symposium on Landslides in the Adriatic - Balkan Region, ReSyLAB, Sarajevo.1: 163-167. Legros, F. (2002). ‘’The mobility of long-runout landslides’’ ...
... mixture of soil and water particles with calculation of velocity. In addition, calculation of pore water pressures propagation is possible to be obtained using Finite Difference Method coupled with two- phase model. Herein, just results of two-phase model propagation will be presented. The main equations ...Jelka Krušić, Biljana Abolmasov, Miloš Marjanović, Manuel Pastor, Saeid M. Tayyebi . "Numerical modeling of Selanac debris flow propagation using SPH code" in SCG-XIII International Symposium on Landslides. Cartagena, Colombia- February 22-26, 2021, International Society for Soil Mechanics And Geotechnical Engineering (2021)
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Control of substructure construction of railways in the Republic of Serbia
Контрола збијености природног тла (у ископу) или збијеног у насипу при изградњи саобраћајница представља један од основних облика контроле квалитета доњег строја. Код изградње брзих саобраћајница (аутопутеви и брза железница) приоритет је постизање високог нивоа контроле извршених радова. У циљу онемогућавања диференцијалног слегања (при изградњи насипа), или промене запремине услед допунског збијања материјала, које неминовно доводе до деформација, потребно је извршити оптимално збијање материјала. У оквиру овог рада приказује се техничка регулатива која регулише контролу збијености при изградњи железничке ...... adopted for the control of compaction of the substructure of railway tracks by the dynamic method with a light falling weight (Light Weight Deflectometer) device on the JŽ railway network. In 2012, the Regulations on the design of reconstruction and construction of specific elements of the railway infr ...
... modulus of deformation Evd are not even listed, so based on the application of these Regulations, they are not even authoritative. Applying only this method, which has a high percentage of subjectivity (depending on the expertise of the examiner) can have a number of negative consequences, some of which ...
... control of compaction of the substrate of railway tracks by the dynamic method with a device with a light falling weight on the JŽ railway network, Official Gazette ZJŽ No. 1/2006, Belgrade, Serbia, 2006. [2] Regulations on the design of reconstruction and construction of certain elements of the railway ...Dragan Lukić, Dragoslav Rakić, Irena Basarić Ikodinović. "Control of substructure construction of railways in the Republic of Serbia" in International Conference On Contemporary Theory and Practice in Construction XV, Banja Luka 16-17 jun 2022., University of Banja Luka Faculty of Architecture, Civil Engineering and Geodesy (2022)
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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... 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 effects of surrounding soil and can be applied in complex geological conditions which are very often in Serbia. The ...
... together with piles, contribute to a target value of safety factor of the landslide. Accordingly, all relevant factors are presented in the paper. KEY WORDS: landslide stabilization, landslide-pile interaction, lateral resistance of piles, stability of landslide and piles 294 UVOD Prilikom sanacije ...
... (Brinč Hansen, 1961) Figure 3. Coefficient of lateral pressure which is dependent of cohesion (Brinch-Hansen, 1961) Slika 2. Koeficijent bočnog pritiska tla koji zavisi od vertikalnog, napona Figure 2. Coefficient of lateral pressure which is dependent of verftical stress (Brinch-Hansen, 1961) ...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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Mineral and Thermal Waters of Serbia: Multivariate Statistical Approach to Hydrochemical Characterization
Maja Todorović, Jana Štrbački, Marina Ćuk, Jakov Andrijašević, Jovana Šišović, Petar Papić . "Mineral and Thermal Waters of Serbia: Multivariate Statistical Approach to Hydrochemical Characterization" in Mineral and Thermal Waters of Southeastern Europe, Springer International Publishing (2016). https://doi.org/10.1007/978-3-319-25379-4
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Trans-Lithospheric Diapirism as a Possible Mechanism for Ophiolite Emplacement?
Nikola Stanković, Taras Gerya, Vladica Cvetković, Vesna Cvetkov. "Trans-Lithospheric Diapirism as a Possible Mechanism for Ophiolite Emplacement?" in EGU General Assembly 2024, Vienna, 14-19 April 2024, Göttingen : Copernicus GmbH (2024). https://doi.org/10.5194/egusphere-egu24-568
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Characterization of biochar surface functional groups
In this work, biochar originating from paper fibres was examined. Biochar was prepared via pyrolysis method at 550°C. Oxygen-containing functional groups on biochar surface were determined. The surface functional groups of biochar were analysed by Fourier transform infrared spectroscopy. The amount of oxygen-containing functional groups was performed with Boehm titration. The total acidity of biochar was mostly attributed to carboxylic and lactonic groups.Marija Ilić, Vesna Pavelkić, Aleksandar Lolić, Branko Leković. "Characterization of biochar surface functional groups" in Šesti Naučno-stručni skup Politehnika, Beograd, 10. decembar 2021., Beograd : Akademija tehničkih strukovnih studija (2021)
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Cytotoxic activity of tetradentate Schiff Base Copper(II) complexes
Istraživanje kompleksa bakra kao potencijalnih antikancerogenih agenasa nudi ohrabrujuće perspektive u odnosu na komplekse platine (II) računajući na smanjenu toksičnost, novi mehanizam delovanja, različit spektar aktivnosti i perspektivu neunakrsne rezistencije. Kompleksi Šifovih baza bakra(II) koji sadrže tetradentatne ligande acac2en tipa (acac2en (1); tfacac2en (3), acactfacacen (4), acacphacacen (6)) pokazali su važnu antioksidativnu aktivnost, visok potencijal za interakciju sa HSA i DNK, u prethodnim studijama. Zbog toga je bilo interesantno ispitati i uporediti potencijal antikancerogene aktivnosti in vitro, u odnosu ...Nevenka Gligorijević, Aleksandar Mijatović, Sandra Aranđelović, Rada Baošić . "Cytotoxic activity of tetradentate Schiff Base Copper(II) complexes" in The European Association for Cancer Research 2021 , eacr2021.org/sponsorship (2021)
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Temperature induced evolution of nanostructured Ni0.9Zn0.1O
Kremenović Aleksandar, Antić Bratislav, Vučinić-Vasić Milica, Colomban Philippe, Jovalekić Čedomir, Bibić Nataša, Kahlenberg Volker, Leoni Matteo (2010)The crystal structure and microstructure of as-prepared and annealed Ni0.9Zn0.1O were refined at room temperature in both the Fm (3) over barm and R (3) over barm space groups. It is shown that below the Neel point (458 K), where magnetic ordering triggers the presence of a trigonal strain, the common usage of a higher-symmetry non-admissible space group for crystal structure and microstructure analysis via the Rietveld method may result in both an incorrect structure description and incorrect microstructure ...Kremenović Aleksandar, Antić Bratislav, Vučinić-Vasić Milica, Colomban Philippe, Jovalekić Čedomir, Bibić Nataša, Kahlenberg Volker, Leoni Matteo. "Temperature induced evolution of nanostructured Ni0.9Zn0.1O" in Journal of Applied Crystallography no. 43, Denmark: Blackwell Munksgaard (2010). https://doi.org/10.1107/S0021889810019163
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Resource-based WordNet Augmentation and Enrichment
In this paper we present an approach to support production of synsets for SerbianWordNet(SerWN)byadjustingPrincetonWordNet(PWN)synsetsusing several bilingual English-Serbian resources. PWN synset definitions were automatically translated and post-edited, if needed, while candidate literals for Serbian synsets were obtained automatically from a list of translational equivalents compiled form bilingual resources. Preliminary results obtained from a setof1248selectedPWNsynsetsshowthattheproducedSerbiansynsetscontain 4024 literals, out of which 2278 were offered by the system we present in this paper, whereas experts added the remaining 1746. Approximately one half of ...... non-English wordnets are concerned, one of the common approaches to wordnet enhancement is the use of a developed wordnet (most commonly PWN) as the basic source for enrichment, and a method for aligning the synsets of the two wordnets, such as the ILI. Automatic alignment of synsets belonging to different ...
... ness of the method is strongly correlated with the comprehensiveness of the resource used in the alignment process (Hristea, 2007). Different methods and resources can be used for alignment. One of the common approaches is to take PWN as the source for alignment, and a bilingual dictionary of English ...
... languages. Vintar and Fišer (2017) proposed a method to enrich the Slovenian WordNet (sloWNet) with domain-specific single and multi- word expressions. They used a large monolingual Slovene corpus of texts to extract terminology from the domain of informatics, and a parallel English-Slovene corpus ...Ranka Stanković, Miljana Mladenović, Ivan Obradović, Marko Vitas, Cvetana Krstev. "Resource-based WordNet Augmentation and Enrichment" in Proceedings of the Third International Conference Computational Linguistics in Bulgaria (CLIB 2018), May 27-29, 2018, Sofia, Bulgaria, Sofia : The Institute for Bulgarian Language Prof. Lyubomir Andreychin, Bulgarian Academy of Sciences (2018)
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Application of the Fuzzy theory in the evaluation of operating parameters of auxiliary mechanization on open-cast coal mine, case study: pipelayers
Achieved operating parameters are the main indicator of the work quality and selection of mining machines. The effectiveness of a coal mine is correlated with the availability of basic and auxiliary machines. The main task of auxiliary machines in lignite mines is to achieve optimal working conditions. From an economic point of view, auxiliary machines generate up to 20% of the lignite mines' total costs. These are the primary reasons for analyzing their current work and making decisions in ...Stevan Djenadić, Miloš Tanasijević, Filip Miletić, Predrag Jovančić. "Application of the Fuzzy theory in the evaluation of operating parameters of auxiliary mechanization on open-cast coal mine, case study: pipelayers" in 8th Balkan Mining Congress, Belgrade, September 28-30, Rudarski instutut (2022)