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Упит dcterms_subject_txt:rock breakage by explosives

1093 items

  • 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

  • Natural two-dimensional pyrophyllite: Nanoscale lubricant, electrical insulator and easily-machinable material

    Borislav Vasić, Radoš Gajić, Ivana Milošević, Žarko Medić, Marina Blagojev, Marko Opačić, Aleksandar Kremenović, Dejan Lazić (2022)
    Pyrophyllite, with the chemical formula Al2Si4O10(OH)2, is a naturally occurring and abundant van der Waals mineral belonging to the group of phyllosilicates. It is very soft, layered crystal used for sculpting and an excellent electrical and thermal insulator aimed for the operation at high pressure and temperature. Here, for the first time, two-dimensional (2D) pyrophyllite obtained by both mechanical and liquid phase exfoliation is presented and investigated at the nanoscale. The layered structure provides low friction coefficient of around ...
    Atomic force microscopy, Insulating properties, Nanofriction and wear, Natural two dimensional materials, Phyllosilicates, Pyrophyllite

  • Споменица 1991. – 2015. година: 135 година геологије и 70 година рударства на Универзитету у Београду

    главни и одговорни уредник Душан Поломчић (2016)
    Рударско-геолошки факултет
    ... mining engineering, 21, Belgrade 2012. TORBICA S., LAPCEVIC V., 2014: Rock breakage by explosives. European Inter- national Journal of Science and Technology, 96–104. TORBICA S., LAPCEVIC V., 2014: Model for estimating blasted rock fragmentation. 14th SGEM GeoConference on Science and Technologies in ...
    ... kopa na stabilnost kosina. Tehnika, 4. TORBICA S., LAPCEVIC V., 2014: Rock breakage by explosives. European Inter- national Journal of Science and Technology, 96–104. TORBICA S., LAPCEVIC V., 2014: Model for estimating blasted rock fragmentation, 14th SGEM GeoConference on Science and Technologies In ...
    ... of the 34th Annual Conference on Explosives and Blasting Technique, 27.-30. January, New Orleans, LA, SAD, Vol. II, International Society of Explosives Engineers, pp. 265–272. MITROVIĆ S., KRIČAK L., NEGOVANOVIĆ M., JANKOVIĆ I., ZEKOVIĆ D., 2009: Influence of rock mass blastability on explosive energy ...

  • 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.

  • 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)
    Earth-Surface Processes

  • Building learning capacity by blending different sources of knowledge

    Ivan Obradović, Ranka Stanković, Olivera Kitanović, Dalibor Vorkapić (2016)
    ... 03:38:04 Building learning capacity by blending different sources of knowledge Ivan Obradović, Ranka Stanković, Olivera Kitanović, Dalibor Vorkapić Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Building learning capacity by blending different sources of knowledge ...
    ... on blending academic and entrepreneurial knowledge by means of technology enhanced learning. To that end a network of organizations is being formed where open educational resources will be published and shared. The main goals to be reached by this network, as well as its salient features are described ...
    ... that permits their free use, access, repurposing, reuse and redistribution by others with limited or no restrictions (Atkins et al., 2007). The OCW was initiated in 1999 with the publishing of videos of lectures online by the University of Tübingen in Germany. It gained impetus three years later ...

  • The Nooj System as Module within an Integrated Language Processing Environment

    Ranka Stanković, Duško Vitas, Cvetana Krstev (2008)
    NooJ, electronic dictionary, lexical resources
    ... tasks such as query expansion. By this we mean the techniques in which a query, serving as input to a document retriever, is transformed in some way in order to improve the performance of document retrieval. Namely, a search by a concept instead of a search by a single word form is recognized ...
    ... and expansion of queries by graphs and regular expressions. The integration of the morphological power of NooJ with the semantic and multilingual power of wordnets may best be illustrated by concordance production using various search requirements such as extraction by simple strings, lemmas (with ...
    ... Similarly, English query ‘document‘, is expanded by English wordnet to ‘document, written document, papers’ which is then transformed by ILI to a set of Serbian keywords: ‘dokument, papir, akt’ that can be further expanded to all inflectional form by NooJ inflectional graphs: ‘document, dokumenta ...

  • VENTEX: An Expert System for Mine Ventilation Systems Analysis

    Ranka Stanković, Nikola Lilić, Ivan Obradović (1996)
    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 ...
    ekspertni sistem, ventilacija
    ... statements and procedures are represented by frames, which makes it a flexible and open concept for knowledge representation. In the same way object characteristics are represented by their attributes, frame characteristics are represented by their slots. Namely, the slot values describe ...
    ... using applications by means of a high-level graphical environment. In the KAPPA-PC system, the components of the domain are represented by objects that can be either classes or instances within classes. The relationships among the objects in a model can be represented by linking them together ...
    ... Faculty of Mining and Geology in Belgrade. The problem-solving process in VENTEX unfolds by means of the KAPPA-PC backward chaining inference engine. Goals to be satisfied by backward chaining are defined by means of the goal editor as shown on /Fig. 9/. The goals in VENTEX pertain to estimation ...

  • Coupling of artificial intelligence methods in the development of hybrid intelligent systems

    Ranka Stanković, Ivan Obradović, Nikola Lilić (2001)
    In this paper we present an approach which couples various artificial intelligence (AI) methods in the solution of complex problems that cannot adequately be solved by a single AI method. We argue that the resulting, hybrid intelligent systems (HIS) can be successfully implemented with the use of available AI software libraries. Different coupling methods are analyzed and a classification of hybrid systems based on the chosen method is given. Two case studies of hybrid systems used in mining engineering ...
    hibridni inteligentni sistemi, spregnuti sistemi, metode veštačke inteligencije, rudarske primene veštačke inteligencije
    ... particular class of problems. Complex problems often cannot be solved by any of the existing AI methods alone. Hybrid intelligent systems [1] are an attempt to solve these complex problems by coupling two or more AI methods, but also by integrating AI methods and conventional computer systems, such as ...
    ... endangerment of an area by air pollution. The paper ends with a few concluding remarks. 2. Hybrid intelligent systems The motivation for coupling one or more AI methods into a hybrid system is, in general, one of the following [6]: 1) Function-replacing - enhancing one AI method by means of another ...
    ... usually consists of the following six stages: 1) Problem analysis; 2) Identification of the properties required by an intelligent method in order to solve the given problem, followed by the selection of appropriate method(s); 3) Selection of an appropriate hybrid system type; 4) Implementation; ...

  • The Usage of Various Lexical Resources and Tools to Improve the Performance of Web Search Engines

    Krstev Cvetana, Stanković Ranka, Vitas Duško, Obradović Ivan (2008)
    In this paper we present how resources and tools developed within the Human Language Technology Group at the University of Belgrade can be used for tuning queries before submitting them to a web search engine. We argue that the selection of words chosen for a query, which are of paramount importance for the quality of results obtained by the query, can be substantially improved by using various lexical resources, such as morphological dictionaries and wordnets. These dictionaries enable semantic ...
    LR web services, MultiWord Expressions & Collocations, Information Extraction, Information Retrieval
    ... ps between them. On the other hand, concepts are lexicalized by one or more synonymous words (simple or compound). For example, the concept of a “housing that someone is living in” is lexicalized by the word “house”, but also by “dwelling”, “home”, “domicile”, “abode”, “habitation” or “dwelling ...
    ... We argue that the selection of words chosen for a query, which are of paramount importance for the quality of results obtained by the query, can be substantially improved by using various lexical resources, such as morphological dictionaries and wordnets. These dictionaries enable semantic and morphological ...
    ... making the query bilingual. Problems encountered in retrieving documents of interest are discussed and illustrated by examples. A brief description of resources is given, followed by an outline of the web tool which enables their integration. Finally, a set of examples is chosen in order to illustrate ...

  • WS4LR - a Worksation for Lexical Resources

    Cvetana Krstev, Ranka Stanković, Duško Vitas, Ivan Obradović (2006)
    Lexical Resources, Wordnet, Serbian
    ... Each synset word or “literal” is denoted by a “literal string” followed by a “sense tag” which represents the specific sense of the literal string in that synset, pretty much as in any explanatory dictionary, where an entry corresponding to a word is followed by number of its possible meanings. Following ...
    ... ILI. The user can navigate through wordnets by following hypernym/hyponym relations. Synsets can be retrieved using various methods, from simple string matching to complex Xpath expressions, either predefined or specified by the user. For instance, by means of the Xpath expression “//SYNSET[DOM ...
    ... shortcoming and enable better exploitation of aligned texts as resources of great value. This is achieved by an integration of all the resources supported by WS4LR. It may best be illustrated by concordance production using various search criteria such as simple strings, lemmas (with all their inflectional ...

  • Quantitative analysis of syllable properties in Croatian, Serbian, Russian, and Ukrainian

    Biljana Rujević, Marija Kaplar, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Jan Mačutek (2021)
    slogovi, distribucija rang-preciznost, slovenski jezici

  • Legal framework for recultivation of degraded areas caused by mining exploitation

    Radmila Gaćina (2023)
    Prilikom površinske i podzemne eksploatacije uglja eksploatacioni sistemi oštećuju veće ili manje površine zemljišta. Iskustva pokazuju da su oštećenja zemljišta znatno veća kod površinske eksploatacije, gde je prostora degradiran ne samo u konturi rudnika i okoline, već se promene takođe dešavaju u prirodnom okruženju. U članku su predstavljeni rezultati studije zakonskih okvira rekultivacije u nekim zemljama sveta i u Srbiji. Praktično iskustvo rekultivacije pokazalo je da iskorišćenje i devastacija tokom rudarske aktivnosti predstavljaju opasnost ne samo za pogođena ...
    rekultivacija, melioracija, otkopavanje uglja, zakonska regulativa
    ... issued in 1988, the main differences can be summarized by the following several aspects: 1. The definition of the reclamation object is more comprehensive. In addition to the damaged land by production and construction activities, damaged land by natural disasters is taken into consideration: 2 ...
    ... Legal framework for recultivation of degraded areas caused by mining exploitation Radmila Gaćina Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Legal framework for recultivation of degraded areas caused by mining exploitation | Radmila Gaćina | Underground mining ...
    ... s regarding the protection of land from pollution and damage, as well as the mandatory undertaking of reclamation works, is regulated by several legal and by-laws, each of which, from its point of view, regulates this problem (Ivković at all, 2013). In the field of mining, the basis is the Law ...

  • 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
    ... affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). 1 Faculty of Technology ...
    ... reduced by 60% after the MICP treatment by Micrococcus sp. isolated from Microorganisms 2021, 9, 1691. https://doi.org/10.3390/microorganisms9081691 https://www.mdpi.com/journal/microorganisms microorganisms Article Comprehensive Profiling of Microbiologically Induced CaCO3 Precipitation by Ureolytic ...
    ... affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by / 4.0/). 1 Faculty of Technology Novi ...

  • Open Educational Resources in Serbia

    Ivan Obradović, Ranka Stanković, Marija Blagojević, Danijela Milošević (2020)
    Open educational resources, BAEKTEL, Metadata portal
    ... .org/) 4 Chapter # - will be assigend by editors The Platform provides intelligent search ordering by scoring resources against keywords on the basis of user search activity, preselected groups of resources, resource access level permissions by user group, multilinguality, allowing the ...
    ... portal there are currently 78 items indexed, classified by type as: Lessons (24), Exercises (21), Best Practices and case studies (17), Portal (11), Guidelines and other (5). Detailed statistics by target group is # - will be assigend by editors. OPEN EDUCATIONAL RESOURCES IN SERBIA 11 ...
    ... of BAEKTEL portal content by type Topics of content (titles and keywords) are visualised by a word cloud in Figure 3. It can be seen that computer science, modeling and language technologies are dominant. 12 Chapter # - will be assigend by editors ...

  • Numerical modeling of Selanac debris flow propagation using SPH code

    Jelka Krušić, Biljana Abolmasov, Miloš Marjanović, Manuel Pastor, Saeid M. Tayyebi (2021)
    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 ...
    debris flow, modelling, SPH code, DEM
    ... , Tonni, L., Drempetic, V. (2008) ‘’Mathematical, constitutive and numerical modelling of catastrophic landslides and related phenomena’’. Rock Mech Rock Eng 41:85–132. Pastor, M., Blanc, T., Haddad, B. et al. (2014). ‘’Depth Averaged Models for Fast Landslide Propagation: Mathematical, Rheological ...
    ... papers published under the Auspices of the ISSMGE and maintained by the Innovation and Development Committee of ISSMGE. The paper was published in the proceedings of the 13th International Symposium on Landslides and was edited by Miguel Angel Cabrera, Luis Felipe Prada-Sarmiento and Juan Montero ...
    ... was made by comparing against the field investigation and high resolution Digital Terrain Model (DTM), also. Final models show accurate results comparing to the depths in deposition zone, but actual run-out distance of debris flow was longer than the measured run-out distance obtained by the SPH ...

  • Mine surveying works for the purpose of excavating the remaining reserves of bauxite in the deposit of “Podbracan”

    Aleksandar Milutinović, Aleksandar Ganić, Thamer Rayes Diyab, Rade Tokalić, Meri Ganić (2015)
    ... gallery, by rock drilling of mining holes in the shape of semi-fan and blasting ("semi-fan"). Angle of blasting surface is 60°, while the internal distance between the semi- fans is 1.8m, which is the least resistance line at the same time. The transport and hauling of the ore is realized by the ...
    ... decided to excavate the remaining reserves by us- ing an underground method of mining. For the purpose of this, the Main Mining Design was elaborated (Faculty of Mining and Geology, 2008), whose technical and technological solutions were conditioned by the spatial position and geometry of the open ...
    ... sep. | 2015 4. Selection of opening and development solutions The opening, development and excavation concept is conditioned by the natural conditions of the deposit and by its technical and technological conditions. Figure 2 shows the mine layout with the existing and newly designed mine cham- ...

  • Cutting Resistance Laboratory Testing Methodology for Underwater Coal Mining

    Vladimir Čebašek, Veljko Rupar, Stevan Đenadić, Filip Miletić (2021)
    Geology,Geotechnical Engineering and Engineering Geology
    ... strength index proposed by Protodjakonow [1,14] were used. Rock material strength index, fpr, proposed by Protodjakonow is determined by the uniaxial compressive strength, σc (MPa), of the rock material, for which he gave the relationship: fpr = σc/10 (MPa) (1) Protodjakonow classifies the rocks and ...
    ... test: (a) rock or soil sample in triaxial test and (b) triaxial cell with sample [25,28,29]. The sample is also being loaded by a vertical force, by using a steel rod that passes through the top cap of the cell. In the second stage of the test, the rod gets pushed down, at a constant rate, by an electric ...
    ... mines. Nevertheless, the cutting resistance can only be determined by laboratory tests carried out on the drilling core samples or block-shaped rock material samples. The results of laboratory testing allow comparison with test results of rock samples from other mines in which bucket-wheel excavators are ...

  • SrpELTeC: A Serbian Literary Corpus for Distant Reading

    Ranka Stanković, Cvetana Krstev, Duško Vitas (2024)
    U članku je predstavljen SrpELTeC, korpus razvijen u okviru akcije COST Distant Reading for European Literary History (CA16204). Svi romani u SrpELTeC-u su odabrani, pripremljeni i obeleženi korišćenjem zajedničkih principa uspostavljenih za sve jezičke zbirke u Evropskoj zbirci književnog teksta (ELTeC). Navedeni su izazovi i rešenja u pripremi SrpELTeC od nule. Svi romani su ručno kodirani u TEI sa bogatim metapodacima i strukturnim napomenama. Automatska anotacija je uključivala POS-označavanje, lematizaciju i imenovane entitete, oslanjajući se na resurse za obradu ...
    digital humanities, Serbian literature, text corpora, distant reading , linked data, named entity recognition, text analytics

  • Terminology Acquisition and Description Using Lexical Resources and Local Grammars

    Cvetana Krstev, Ranka Stanković, Ivan Obradović, Biljana Lazić (2015)
    Acquisition of new terminology from specific domains and its adequate description within terminological dictionaries is a complex task, especially for languages that are morphologically complex such as Serbian. In this paper we present an approach to solving this task semi-automatically on basis of lexical resources and local grammars developed for Serbian. Special attention is given to automatic inflectional class prediction for simple adjectives and nouns and the use of syntactic graphs for extraction of Multi-Word Unit (MWU) candidates for ...
    ... the class N4X implies that MWUs belonging to it consist of a noun followed by two other components (separated by two separators) that do not inflect. The syntactic structure of these components can be a noun followed by two adjectives/nouns in the genitive case (e.g. eksploatacija mineralnih sirovina ...
    ... noun followed by two adjec- tives/nouns in the genitive case or in the in- strumental case; e.g. otkopavanje širokim čelom ‘broad forehead excavation’. b. NprepNp - A noun followed by a preposi- tional phrase; e.g. lanac sa grabuljama ‘chain with a rake’. 5. AXN2X – a noun preceded by an adjective ...
    ... preceded by two adjectives that agree with it in gender, number, case and animateness; e.g. površinski istražni radovi ‘surface exploration works’. 8. N6X - a noun followed by three words that do not inflect in the MWU. Three syntactic structures are possible: a. NNgiPrepNp - a noun followed by a noun ...