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Упит dcterms_subject_txt:quality of service

2855 items

  • Model of the Geomagnetic reference field of the Republic of Serbia

    Spomenko J. Mihajlović, Vesna Cvetkov (2024)

  • Testing the energy value of different types of coal by the method of active thermography

    Stevan Đenadić, Ljubiša Tomić, Vesna Damnjanović, Predrag Jovančić, Dragutin Jovković (2020)
    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 ...
    Infrared imaging, nondestructive testing, active thermography, coal.

  • Mesozoic carbonate rocks in Serbia used as dimension stone

    Vesna Matović, Tijana Vojnović Ćalić (2016)
    The building industry in Serbia uses, to a great extent, imported natural stone for architectural purposes. The significance of local deposits, particularly limestones, is not adequately perceived despite the country’s abundance of these valuable resources. Therefore, this study focuses on Serbia’s Mesozoic carbonate rocks, specifically on the deposits of four selected quarries: Klisura, Skrzut, Struganik, and Tisnica. The quality and prospects of the application of these limestones has not yet been the subject of a detailed, comprehensive investigation. Therefore, ...
    Ukrasni kamen, Mezozoik, Krečnjak, Srbija, Petrografija, Fizičko-mehanička svojstva
    ... investigation of quality in terms of the possibility of use has not yet been conducted. Although some indi- vidual limestone quarries have deposits of more than a million cubic metres, with the potential production capac- ity of approximately 10,000 m* of blocks and 15,000 m? of panels per year ...
    ... Klisura, Skrzut, Struganik, and Tisnica. The quality and prospects of the application of these limestones has not yet been the subject of a detailed, comprehensive investigation. Therefore, this research is primarily concerned with the examination of their petrological and physico-mechanical properties ...
    ... appearance and the decorative quality of the limestone (Fig. 2c). The amount of CaCOy in these limestones is high, from 97.46 to 99.96 %, and with a mean value of 98.76 %, they belong to pure limestones. With regards to textural features, coarseness and type of allochem, these limestones correspond ...

  • Properties of fly ash and slag from the power plants

    Miloš Šešlija, Aleksandra Rosić, Nebojša Radović, Milinko Vasić, Mitar Đogo, Milovan Jotić (2016)
    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
    ... composition is composed of the following chemi- cal components: SiO2, Al2O3, Fe2O3, CaO, MgO, SO3, S, Na2O and K2O. Results of laboratory tests show that fly ash and slag have variable chemical, mineralogical and physical properties that are dependent on the natural composition, quality of coal from basin ...
    ... composition and quality of coal for each specific coal basin, – dependencies between the chemical, mineral and physical properties make a good basis for predicting and solving- specific technological and ecological problems related to the use of ash and slag, – using different types of coal from Kolubara ...
    ... – Association of Civil Engineers and Technicians of Serbia, Belgrade. SRPS B.H8.359 (1973): Methods of analysis of coal and coke – Determination of chem- ical composition of fuel ash – General requirements. SRPS B.H8.360 (1973): Methods of analysis of coal and coke – Determination of silica (SiO2) ...

  • Application of stochastic models for mine planning and coal quality control

    Dejan Stevanović, Božo Kolonja, Ranka Stanković, Dinko Knežević, Mirjana Banković (2014)
    ... siderably, the quality of run of mine (ROM) coal composite will depend on both the quality and quantity of coal mined from each active bench. If it is desired to control the ROM coal quality, the rate of coal production from each active bucket wheel excavator (BWE) should be regulated. The effect of this approach ...
    ... Therefore, we de- scribe prediction of the performance of stock- piling systems for which reclaim slices include unequal amounts of material from the layers of material stacked, fig. 3. Quality of the reclaimed material is calcu- lated as the weighted average of pieces of the layers that are taken from the ...
    ... the layers of material stacked, fig. 3. Quality of the reclaimed material is calcu- lated as the weighted average of pieces of the layers that are taken from the bed. In this calcu- lation, each piece's quality is weighted by its volume. More precisely, let Xij be the average grade of the material ...

  • Parameter determination of soil oscillation law using quotient of the relative growth increments of oscillation velocity and reduced distances at “Nepričava“ open pit mine

    Suzana Lutovac, Sanja Bajić, Marina Ravilić, Radmila Gaćina (2015)
    ... effect of elastic seismic wave is movement of particles of the rock mass from its equilibrium position. Such oscillation of the rock mass particles is manifested as a shock and represents one of the negative effects of blasting. In order both to evaluate and control the seismic effect of blasting ...
    ... velocity of the rock mass and basic parameters affecting its magnitude, being: the amount of explosive, the distance from the blast site, characteristics of the rock mass and the type of blasting, it is the equation of M. A. Sadovski that is used most commonly. In this paper, the law of Sadovsky ...
    ... quotient of the relationship between relative growth of oscillation velocity of the rock mass and relative growth of reduced distances. Thereby, in a marginal case, a differential equation, whose general integral overlaps with the law of Sadovski, is obtained. Parameters n and K in the law of Sadovsky ...

  • Развој геолошког терминолошког речника ГеолИССТерм

    Ranka Stanković, Branislav Trivić, Olivera Kitanović, Branislav Blagojević, Velizar Nikolić (2011)
    ... . Thus, the expansion of the range of terms included in geolISS will continue to be a fundamentally and operationally important task, aimed primarily at a clearer determination of the geologic content and improving the quality of geologic data. Immediate and end users of the information system ...
    ... carried out by the Faculty of mining and geology, University of Belgrade, funded by the ministry of the environment and Spatial Planning of the republic of Serbia. A short history of geolISSTerm and an overview of the structure and the way of arranging terms, in view of the terminological resources and ...
    ... on of the geologic Information System of Serbia (geolISS) in mid- 2006 marked the beginning of development of the geologic terminology and nomenclature. The main aim of the development of this electronic resource was the creation of a standard dictionary of geologic terms for the purpose of providing ...

  • Groundwater gravitational circulation of Karst Veliko Vrelo and Malo Vrelo springs by isotope and the noble gas method: case study of the Beljanica Massif

    Ljiljana Vasić, Laszlo Palcsu, Huang Fen (2019)
    Earth-Surface Processes, Geology, Pollution, Soil Science, Water Science and Technology, Environmental Chemistry

  • Characterization and Environmental Evaluation of Recycled Aggregates from Construction and Demolition Waste in Belgrade City Area (Serbia)

    Filip Abramović, Miroslav Popović, Vladimir Simić, Vesna Matović, Radmila Šerović (2024)
    General Materials Science

  • Knowledge and Rule-Based Diacritic Restoration in Serbian

    Cvetana Krstev, Ranka Stanković, Duško Vitas (2018)
    In this paper we present a procedure for the restoration of diacritics in Serbian texts written using the degraded Latin alphabet. The procedure relies on the comprehensive lexical resources for Serbian: the morphological electronic dictionaries, the Corpus of Contemporary Serbian and local grammars. Dictionaries are used to identify possible candidates for the restoration, while the dataobtainedfromSrpKorandlocalgrammarsassistsinmakingadecisionbetween several candidates in cases of ambiguity. The evaluation results reveal that,dependingonthetext,accuracyrangesfrom95.03%to99.36%,whilethe precision (average 98.93%) is always higher than the recall (average 94.94%).
    diacritic restoration, morphological dictionary, corpus, word n-grams, local grammars
    ... The quality of the disambiguation proce- dure was previously evaluated as 75% (F-measure) for domain-specific thesauri (Security thesaurus and Sociopolitical thesaurus). Green and orange boxes on Fig. 4 show ambiguous words that were not disambiguated in the current processing. The quality of dis ...
    ... information-analytical systems as a tool of conceptual indexing and search, various forms of query expansion can be carried out. One of the main applications of RuThes-like ontologies is text categorization and other tasks of text analytics. The mainstream technology of automatic document categorization ...
    ... was semi-automatically generated from the published version of RuThes (RuThes-lite 2.0) (Loukachevitch et al., 2018). Table 2: Quantitative characteristics of synsets and entries in RuWordNet Part of Speech Number of Number of Number of Synsets Unique Entries Senses Nouns 29,296 68,695 77,153 Verbs ...

  • Project REASONING: Characterization and technological procedures for recycling and reusing of the rudnik mine flotation tailings

    Vesna Cvetkov, Vladimir Simić, Stefan Petrović, Filip Arnaut, Milena Kostović, Dragan Radulović, Jovica Stojanović, Vladimir Jovanović, Dejan Todorović, Nina Nikolić, Jelena Senćanski, Grozdanka Bogdanović, Dragana Marilović (2024)

  • Review: Methodological approaches and research techniques for addressing construction and remediation problems in karst reservoirs

    Saša Milanović, Ljiljana Vasić (2021)
    Earth and Planetary Sciences (miscellaneous), Water Science and Technology

  • Mineral and Thermal Waters of Serbia: Multivariate Statistical Approach to Hydrochemical Characterization

    Maja Todorović, Jana Štrbački, Marina Ćuk, Jakov Andrijašević, Jovana Šišović, Petar Papić (2016)

  • Mine ventilation system planning using genetic algorithms

    Nikola Lilić, Ranka Stanković, Ivan Obradović (1997)
    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 methods

  • Development of an Integrated Model for Open-Pit-Mine Discontinuous Haulage System Optimization

    Miodrag Čelebić, Dragoljub Bajić, Sanja Bajić, Mirjana Banković, Duško Torbica, Aleksej Milošević, Dejan Stevanović (2024)
    The selection of the optimal equipment for discontinuous haulage systems is one of the most important decisions that need to be made when an open-pit mine is designed. There are a number of influencing factors, including natural (geological and environmental), technical, economic, and social. Some of them can be expressed numerically, in certain units of measure, while others are descriptive and can be stated by linguistic variables depending on the circumstances of the project. These factors are characterized by ...
    rudarska mehanizacija, znanje eksperta, lingvističke varijable, FAHP

  • Open Educational Resources in Serbia

    Ivan Obradović, Ranka Stanković, Marija Blagojević, Danijela Milošević (2020)
    Open educational resources, BAEKTEL, Metadata portal
    ... enthusiasm of teachers and students. In recent times the concept of OER has been recognized as a very important part of teaching process through many initiatives, working groups… Learners Learners as initial target group for OER give valuable feedback about OER quality and improvement of current ...
    ... Module” at the Faculty of Technical Sciences Čačak. She holds certificates for training on Quality assurance in Higher Education by EFQUEL - European Foundation for Quality in e-Learning. She is the president of Balkan Distance Education Network BADEN, and editor in chief of BADEN Newsletter aiming ...
    ... Law on Foundations of Educational System, which regulates the preschool, primary and secondary education. Namely, in Article 46a of this Law, a Center for Educational Technology is envisaged within the Institute for Education Quality and Evaluation. With the competence of this Center, Item 4 ...

  • The analysis of the geothermal energy capacity for power generation in Serbia

    Jana Stojković, Goran Marinković, Petar Papić, Mihailo Milivojević, Maja Todorović, Marina Ćuk (2013)
    Renewable Energy, Sustainability and the Environment
    ... Report of Hydrochemical Investigations of Geothermal Water in Vranjska spa (in Serbian), Fac- ulty of Mining and Geology, University of Belgrade, Belgrade, Serbia, 1994 [13] Papi}, P., Scaling and Aggressive Properties of Mineral Waters of Serbia (in Serbian), Ph. D. thesis, Uni- versity of Belgrade ...
    ... 7.1 224.2 Heating Besides natural discharge of thermal water of the temperatures up to 83 °C, water of 111 °C flows out the wells VG-2 (1064 m) and VG-3 (1470 m) at the rate of 50 L/s in Vranjska Banja. The granitoid intrusion of Surdulica, a product of Tertiary magmatism, is believed re- sponsible ...
    ... ]UK a a University of Belgrade, Faculty of Mining and Geology, Belgrade, Serbia b Geological Survey of Serbia, Belgrade, Serbia Original scientific paper DOI: 10.2298/TSCI120215033S An estimate of deep groundwater temperature is necessary for the research and uti- lization of this geothermal resource ...

  • Influence of mono- and two-component organic modifiers on determination of lipophilicity of tetradentate Schiff bases

    Nikola Stevanović, Aleksandar Mijatović, Aleksandar Lolić, Mario Zlatović, Rada Baošić (2021)
    Ispitivani su uticaji primene mono- i dvokomponentnih organskih modifikatora na određivanje lipofilnosti 12 tetradentatnih Šifovih baza metodom reverzno-fazne tankoslojne hromatografije. Osnovni cilj je da se proceni tip interakcije između posmatranih jedinjenja i komponenti primenjenih hromatografskih sistema i uspostavi neki obrazac ponašanja kako bi se lakše izabrala kombinacija organskih modifikatora koji će simulirati interakciju u biološkim sistemima na osnovu činjenica da iste osnovne intermolekularne interakcije su odgovorne za ponašanje supstanci i u biološkom i u hromatografskom sistemu. Primenjeni organski modifikator ...
    Šifove baze, Lipofilnost, RP-TLC, Organski modifikatori

  • 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
    ... according to the type of pyrolysis. The quality of the spectra is considerably reduced in comparison with spectra of well-defined molecular compounds. The structural and reflective properties of the chars and the presence of a variety of overlaying bands lead to less resolved IR bands of relatively low ...
    ... methods. None of the spectroscopic methods was found to be suitable for the quality control of all types of chars. The most valuable results were obtained by chemical analysis that, however, required the complete determination of the main elements, including that of oxygen, and of inorganic components ...
    ... further reduce the quality of the spectra. All spectra contain positive or negative double peaks of CO, in air at about 2300 cm !. They are a consequence of the improper compensation of the back- ground spectra due to varying CO» content in air and/or a considerable intensity loss of IR radiation between ...

  • Arsenic in tape waters of the south Pannonian basin (Serbia) and arsenic risk assessment

    Petar Papić, Marina Ćuk, Maja Todorović, Jana Stojković, Bojan Hajdin, Nebojša Atanacković, Dušan Polomčić (2012)
    ... Directive 98/83/EC. Council Directive of 3 November 1998 on the quality of water intended for human consump- tion. Official Journal of the European, 1998. 24. REGULATION OF HYGIENIC CORRECTNESS OF DRINKING WATER. Official Gazette of the SFRY No. 42/98 and 44/99 25. WORLD HEALTH ORGANIZATION, Environmental ...
    ... probability of incidence of can- cer from chemical exposure. It is calculated using the fol- lowing formula: R=1-exp(-(SF · ADD) ...where: SF is the oral carcinogenic slope factor and for As, it is equal to 1.5 mg/kg·day. Results and Discussion Quality of Groundwater The quality of groundwater ...
    ... Occurrence in Groundwater of Srem District The Srem District of Vojvodina features groundwater of good quality, with arsenic concentrations falling within the allowed range and 77% of samples having arsenic concen- trations below 10 µg/L (Fig. 5). The most frequent causes of physicochemical non-compliance ...