Претрага
517 items
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Synthesis and characterization of high-pressure and high-temperature sphene (CaTiSiO5)
Jelena Pantić, Vladimir Urbanovich, Vesna Poharc-Logar, Bojan Jokić, Marija Stojmenović, Aleksandar Kremenović, Branko Matović (2014)Sphene (CaTiSiO5), a calcium titanosilicate ceramic has been prepared from a powder mixture of CaCO3, TiO2 and SiO2 using vibro-milling for homogenization and activation of precursors. During the highpressure and high-temperature synthesis (HPS) process at 4 GPa and 1,200 °C, sphene undergoes into phase transition, from room-temperature phase P21/a to high-temperature phase A2/a. Evidence of that structural phase transition is given in this paper using infrared, Raman spectroscopy and X-ray powder diffraction. Rietveld refinement was employed to get the ...Jelena Pantić, Vladimir Urbanovich, Vesna Poharc-Logar, Bojan Jokić, Marija Stojmenović, Aleksandar Kremenović, Branko Matović. "Synthesis and characterization of high-pressure and high-temperature sphene (CaTiSiO5)" in Physics and Chemistry of Minerals, Springer Science and Business Media LLC (2014). https://doi.org/10.1007/s00269-014-0693-x
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Properties of fly ash and slag from the power plants
This paper describes the physical, chemical and mineral properties of ash and slag, which were taken from thermal power plants Nikola Tesla A, Nikola Tesla B, Kostolac A and Kostolac B. The knowledge of the mineralogical material composition is important because the type of minerals directly determines the properties of the fly ash and slag and their possible application. Laboratory tests showed that ash and slag samples consist of the following minerals: amorphous materials, quartz, feldspar, mullite, melilite, cristobalite, ...fly ash, slag, physical composition, chemical composition, mineral composition, X-ray diffraction method... slag from PPNT A, PPNT B, PPKO A and PPKO B were determined by X-ray examinations. X-ray diffraction is a non-destructive ex- perimental method based on the diffraction of X-rays withcrystal lattice sized wavelengths. This method is primarily used for qual- ity analysis, due to the fact that it ...
... 2016 Available online October 20, 2016 Keywords: fly ash, slag, physical composition, chemical composition, mineral composition, X-ray diffraction method cal properties, chemical and mineral compositions of the fly ash from thermal power plants (PP) „Nikola Tesla A” (NT A), „Nikola Tesla ...
... compositionof minerals in the samples of the fly ash and slag are shown in Table 3. Comparing the results of test samples (Table 3) by the X-ray diffraction method it can be observed that: • all samples of ash contain a significant amount of amor- phous material (AM); • samples of ash from Obrenovac ...Miloš Šešlija, Aleksandra Rosić, Nebojša Radović, Milinko Vasić, Mitar Đogo, Milovan Jotić. "Properties of fly ash and slag from the power plants" in Geologia Croatica, Zagreb : Croatian Geological Survey (2016). https://doi.org/10.4154/gc.2016.26
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Surface functional groups and degree of carbonization of selected chars from different processes and feedstock
Marija Ilić, Franz-Hubert Haegel, Aleksandar Lolić, Zoran Nedić, Tomislav Tosti, Ivana Sredović Ignjatović, Andreas Linden, Nicolai D. Jablonowski, Heinrich Hartmann (2022)The knowledge ofthe structural and chemical properties of biochars is decisive for their application as technical products. For this reason, methods for the characterization of biochars that are generally applicable and allow quality control are highly desired. Several methods that have shown potential in other studies were used to investigate two activated carbons and seven biochars from different processes and feedstock. The chars were chosen to cover a wide range of chemical composition and structural properties as a hardness ...Biougalj, različiti procesi dobijanja, različite sirovine, površinski aktivne grupe, x-ray, FT-IR,XPS... HPO,x·12H»O. The recovery rate was determined by spiking the sample with standard solutions of phosphate that were added to 0.2 g of AC2. The average of three recovery values was 97.1%. The linearity of the method was assessed using ordinary least-square regression. X-ray diffraction. The X-ray ...
... for adequate results. The combination of X-ray photoelectron spectroscopy (XPS) and FT-IR spectroscopy allows a rough characterization of surface functional groups, but cannolt discriminate aliphatic and aromatic OH groups. FT-IR might be a suitable method for the quality control of biochars made ...
... analysis Data for the mass fraction X of the main elements related to the mass of the incinerated char are given in Table 2. The concentrations of other elements are listed in Table 3. The sum parameters XcHNos (sum of the main elements), X.; (sum of other elements), X (sum of all analyzed elements) ...Marija Ilić, Franz-Hubert Haegel, Aleksandar Lolić, Zoran Nedić, Tomislav Tosti, Ivana Sredović Ignjatović, Andreas Linden, Nicolai D. Jablonowski, Heinrich Hartmann. "Surface functional groups and degree of carbonization of selected chars from different processes and feedstock" in PLOS ONE (2022). https://doi.org/10.1371/journal.pone.0277365
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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... production were determined by X-ray studies at the Laboratory of Crystallography Faculty of Mining - Geology in Belgrade. X-ray diffraction is a non- destructive experimental method based on the usage of the diffraction of X-rays with crystal lattice sized wavelengths. This method is primarily used for quality ...
... 13286-41 Unbound and hydraulically bound mixters – Part 41: Test method for the determination of the compressive strength of hydraulically bound mixtures // (2003). [19] EN 13286-42 Unbound and hydraulically bound mixters – Part 42: Test method for the determination of the indirect tensile strength of ...
... environment without addition of binder (TA-P-7) X-ray examination has shown that the fly ash is mainly amorphous, but there are also present crystal phase feldspar, melilite, mulit, very little anhydrite and quartz (Fig. 1). Figure 1 The X-ray diagram of the sample, which is exposed for 7 ...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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The Newton method for solving nonlinear equations based on aggregation operators
Nebojša M. Ralević, Dejan Ćebić (2019)Nebojša M. Ralević, Dejan Ćebić. "The Newton method for solving nonlinear equations based on aggregation operators" in XLVI International Symposium on Operational Research SYM-OP-IS, Kladovo, 15-18.9.2019, Универзитет у Београду (2019)
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Definition of criteria and alternatives for choosing the optimal mining method deposits when applying multi: Criteria optimization, Belgrade, June 2024
Sanja Bajić, Dragoljub Bajić, Branko Gluščević, Radmila Gaćina, Josip Išek. "Definition of criteria and alternatives for choosing the optimal mining method deposits when applying multi: Criteria optimization, Belgrade, June 2024" in Podzemni radovi, Beograd, jun 2024, Centre for Evaluation in Education and Science (CEON/CEES) (2024). https://doi.org/10.5937/podrad2444071B
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The external aggregation Newton's method for solving nonlinear equations and applications
Marija Paunović, Dejan Ćebić, Nebojša Ralević. "The external aggregation Newton's method for solving nonlinear equations and applications" in The University Thought - Publication in Natural Sciences, Centre for Evaluation in Education and Science (CEON/CEES) (2020). https://doi.org/10.5937/univtho10-24982
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An optimal sixteenth order family of methods for solving nonlinear equations and their basins of attraction
Dejan Ćebić, Nebojša Ralević, Marina Marčeta. "An optimal sixteenth order family of methods for solving nonlinear equations and their basins of attraction" in Mathematical Communications (2020)
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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 ...... three groups (Table 1): Table 1. Group of parameters by selection method. Selection Method First Group Second Group Third Group Neely [6] x x Valentin [7] x x x Clegg [8] x x x 1 Espin [9] x 1 x 1 x Heinze [10] x x x Alemi [11–14] x x 1 priority. The first group (I) represents methods that use all ...
... the conceptual model of an expert system for optimized selection of an artificial lift method evaluation on the base of fuzzy interferences of the input data. Energies 2020, 13, 1758 5 of 15 Energies 2020, 13, x 5 of 15 Figure 1. The schematic diagram of the fuzzy model. Parameters (B and ...
... level of synthesis, A, B and C parameters are synthesized into the M (Figure 4).Energies 2020, 13, x 9 of 15 Figure 4. Hierarchical structure of fuzzy composition. Partial indicators of optimal method of selection, A, B and C, are presented as membership function μ: A = (μA1,…, μAj,…, μAn); B ...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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Underground loading-haulage equipment selection with application of topsis method with different weighting methods of criteria
The choice of adequate mining machines is one of the most complex problems in the underground exploitation of mineral raw materials. The weight of such a decision is reflected in the high prices of these machines and the occurrence of even greater costs during their use if their choice was wrongly conceived. There are numerous examples from practice in which such decisions were made solely on the basis of comparing the prices of machines, without considering any of the ...utovarno-transportna mehanizacija, izbor, TOPSIS, entropija, standardna devijacija, težina kriterijumaVladimir Krivošić, Luka Crnogorac, Rade Tokalić. "Underground loading-haulage equipment selection with application of topsis method with different weighting methods of criteria" in Underground mining engineering, University of Belgrade - Faculty of Mining and Geology (2024)
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Keyword Extraction from Parallel Abstracts of Scientific Publications
... sed keyword extraction method. The method is based on the structural and statistical properties of text represented as a complex network. The constructed parallel corpus of scientific abstracts with annotated keywords allows a better comparison of the performance of the method across languages since ...
... n of the selectivity-based keyword extraction method (SBKE) is available in [8]. However, in the following section we will explain the basic characteristics of the method to ensure the readability and completeness of the manuscript. 2.1 The SBKE Method The network or graph-based approach, where a network ...
... or removal of OOV keywords, reflecting the greediness of the SBKE method. Note that the SBKE method is designed as “greedy” and extracts as much candi- dates as possible, which can cause the over-generation problem. Still, the SBKE method can circumvent the overgeneration problem by simple tuning of the ...Slobodan Beliga, Olivera Kitanović, Ranka Stanković, Sanda Martinčić-Ipšić . "Keyword Extraction from Parallel Abstracts of Scientific Publications" in Sematic Keyword-Based Search on Structured Data Sources - Third International KEYSTONE Conference, IKC 2017 Gdańsk, Poland, September 11–12, 2017 Revised Selected Papers and COST Action IC1302 Reports, Springer (2017)
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Mean-based iterative methods for finding multiple roots in nonlinear chemistry problems
Dejan Ćebić, Nebojša M. Ralević (2021)Dejan Ćebić, Nebojša M. Ralević. "Mean-based iterative methods for finding multiple roots in nonlinear chemistry problems" in Journal of Mathematical Chemistry, Springer Science and Business Media LLC (2021). https://doi.org/10.1007/s10910-021-01253-3
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Assessing Criteria Weights by the Symmetry Point of Criterion (Novel SPC Method) - Application in the Efficiency Evaluation of the Mineral Deposit Multi-Criteria Partitioning Algorithm
Information about the relative importance of each criterion or the weights of criteria can have a significant influence on the ultimate rank of alternatives. Accordingly, assessing the weights of criteria is a very important task in solving multi-criteria decision-making problems. Three methods are commonly used for assessing the weights of criteria: objective, subjective, and integrated methods. In this study, an objective approach is proposed to assess the weights of criteria, called SPC method (Symmetry Point of Criterion). This point ...Вишекритеријумско одлучивање, тежине критеријума, тачка симетрије критеријума, налазиште минерала, алгоритам, процена учинкаZoran Gligorić, Miloš Gligorić, Igor Miljanović, Suzana Lutovac, Aleksandar Milutinović. "Assessing Criteria Weights by the Symmetry Point of Criterion (Novel SPC Method) - Application in the Efficiency Evaluation of the Mineral Deposit Multi-Criteria Partitioning Algorithm" in Computer Modeling in Engineering & Sciences (2023). https://doi.org/10.32604/cmes.2023.025021
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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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Determination the advantage of solution in Eastern Serbia using the FTOPSIS method and comparison with the TOPSIS method
Sandra Milutinović, Milena Kostović, Ivana Jovanović, Miomir Mikić, Daniel Kržanović. "Determination the advantage of solution in Eastern Serbia using the FTOPSIS method and comparison with the TOPSIS method" in 53 rd International October Conference on Mining and Metallurgy, 3-5 October 2022, Bor, Serbia, Mining and Metallurgy Institute Bor (2022)
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An Efficient Class of Iterative Root-Finding Methods with Applications
Dejan Ćebić, Nebojša Ralević (2021)Dejan Ćebić, Nebojša Ralević. "An Efficient Class of Iterative Root-Finding Methods with Applications" in 2021 IEEE 19th International Symposium on Intelligent Systems and Informatics (SISY), IEEE (2021). https://doi.org/10.1109/SISY52375.2021.9582495
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Novel Hybrid MPSI–MARA Decision-Making Model for Support System Selection in an Underground Mine
objektivne težine kriterijuma, MPSI metoda, višekriterijumsko odlučivanje, MARA metoda, izbor sistema podgrade, podzemna eksploatacijaMiloš Gligorić, Zoran Gligorić, Suzana Lutovac, Milanka Negovanović, Zlatko Langović. "Novel Hybrid MPSI–MARA Decision-Making Model for Support System Selection in an Underground Mine" in Systems, MDPI AG (2022). https://doi.org/10.3390/systems10060248
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Multi-Criteria Approach for Selecting Optimal Dozer Type in Open-Cast Coal Mining
Ivan Janković, Stevan Đenadić , Dragan Ignjatović , Predrag Jovančić , Tomislav Šubaranović, Ivica Ristović (2019)... mathematical calculations with the purpose of finding the optimal solution.Energies 2019, 12, x FOR PEER REVIEW 8 of 16 Figure 5. The structure of the model in choosing the dozers by applying the AHP method. The first step was to define the basic criteria (technical, economic, exploitation, survey) ...
... of this method. Another issue with this method is the lack of objectivity in expert opinion. The AHP method, in addition to the results represented in the paper, provides the conditions for a partial analysis of each criterion, which are analysed in a very simple way. In that way the method can be ...
... of the AHP method is its ability to identify and analyse the inconsistency of the decision-maker in the process of deciding on the priorities in the hierarchal structure. The general schematic display of the AHP method structure is shown in Figure 2. The goal (zero level) of the AHP method structure ...Ivan Janković, Stevan Đenadić , Dragan Ignjatović , Predrag Jovančić , Tomislav Šubaranović, Ivica Ristović . "Multi-Criteria Approach for Selecting Optimal Dozer Type in Open-Cast Coal Mining" in Energies, MDPI (2019). https://doi.org/https://doi.org/10.3390/en12122245
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Vulnerability Assessment as a Basis for Sanitary Zone Delineation of Karst Groundwater Sources—Blederija Spring Case Study
Примена метода рањивости подземних вода има велики значај код делинеације зона санитарне заштите карстних изворишта. Процена рањивости изворишта карстних подземних вода углавном је била базирана на Европском приступу (COST пројекат 620), који укључује анализу фактора К, који се односи на кретање подземне воде кроз засићену зону карстног система. У раду су примењене две методе за процену рањивости подземних вода - COP+K и TDM метода, како би се израдила најпогоднија карта рањивости изворишта која се може трансформисати у карту зона ...заштита изворишта карстних подземних вода, делинеација санитарних зона, COP+K метода, TDM метода, извориште подземних вода БледеријаVladimir Živanović, Nebojša Atanacković, Saša Stojadinović. "Vulnerability Assessment as a Basis for Sanitary Zone Delineation of Karst Groundwater Sources—Blederija Spring Case Study" in Water, MDPI AG (2021). https://doi.org/10.3390/w13192775
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Testing the energy value of different types of coal by the method of active thermography
In this paper, coal thermograms are presented and analyzed in order to determine their energy value. Two types of coal of different categories, brown and lignite, were selected for active thermographic imaging. The tested coal samples were processed before measurement so that they are similar in dimensions and have two plane-parallel smooth surfaces. The test samples were "primarily" heated under the same conditions and the process of their cooling was monitored by a thermal camera. "Then" they were cooled ...Stevan Đenadić, Ljubiša Tomić, Vesna Damnjanović, Predrag Jovančić, Dragutin Jovković. "Testing the energy value of different types of coal by the method of active thermography" in 9th International Scientific Conference on Defensive Technologies, Belgrade, Serbia, 15-16 October 2020, The Military Technical Institute (2020)