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Упит dcterms_subject_txt:Raw materials

365 items

  • Flyrock induced by blasting in surface mining

    Milanka Negovanović, Lazar Kričak, Snežana Ignjatović, Stefan Milanović, Jovan Marković, Nikola Simić, Rade Šarac (2022)
    Miniranje predstavlja i dalje najefikasniji i najjeftiniji način eksploatacije velikih količina čvrstih mineralnih sirovina na površinskim kopovima. Energija eksplozije se koristi za fragmentaciju čvrste stenske mase do zahtevane granulacije. Pored pozitivnih efekata miniranja, postoje i određeni neželjeni efekti svakog procesa miniranja koji se mogu javiti, a to su: potresi tla, razletanje komada stene, vazdušni udari, otrovni i zagušljivi gasovi i prašina. Razletanje komada stene je nekontrolisano izbacivanje fragmenata odminirane stenske mase i predstavlja jedan od glavnih izvora materijalne štete ...
    razletanje, bušenje, miniranje, površinska eksploatacija, bezbednost, nesreća

  • Application of Expansive Mortars for the Formation of Artificial Screens During Blasting in Urban Areas

    Milanka Negovanović, Lazar Kričak, Stefan Milanović, Nikola Simić, Jelena Majstorović (2024)
    During construction of buildings in urban areas, sometimes there is a need to blast solid rock mass in the immediate vicinity of the surrounding buildings. In that case, the aim is not only to increase the efficiency of blasting, but also to reduce harmful effects of ground vibration induced by blasting. At the same time, it is very important to protect the buildings located in the safe zone from the blast site as well as remaining rock mass around ...
    expansive mortar, artificial screens, pressure, rock breaking, building foundation

  • Structural characterization of traditional pottery produced from local clay, Rujište (Ražanj, Central Serbia), in an effort to preserve its geoheritage

    Maja Milošević, Biljana Đorđević, Alena Zdravković (2021)
    ... manufacture of traditional pottery, bread-baking pan called crepulja, prepared with raw local clays from Ražanj area in western Serbia, without any additional tempers added. Pottery manufacture with these specific raw materials and the final function of the product is closely connected, when material dictates ...
    ... Nothing else can be made from these raw clays, nor can these pots be made with the help of a mechanical device – a potter's wheel, which was empirically tested over the years. Investigation of the pottery was conducted to show the main characteristics of the raw clay body based on mineralogy and ...
    ... cathodoluminescence detector (CL) were applied to determine the morphology and grain size assessment of minerals as well as their chemical composition. Raw clay, from which investigated sample of pottery was produced, largely falls under Neogene sediments which are extensive in the area of Ražanj. Investigated ...

  • 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)

  • A hydrogeological model of the open-cast mine Tamnava - West Field (Kolubara Coal Basin, Serbia)

    Jelena Ratković, Dušan Polomčić, Dragoljub Bajić, Bojan Hajdin (2016)
    ... A hydrogeologic model is an interpretation of the dynamic and physical properties of a hydrogeologic system (American Society for Testing and Materials, 2014). According to Polomčić (2001), a hydrologic system is determined by: input elements, characteristics of the medium, processes that take place ...
    ... Yugoslav Opencast Mining Committee, pp. 293-300. 54 Ratković J., Polomčić D., Bajić D., Hajdin B. THE AMERICAN SOCIETY FOR TESTING AND MATERIALS (2016) Available from: http://www.astm.org/DATABASE.CART/WITHDRAWN/D5447.htm [Acessed 23/11/16]. ŠUBARANOVIĆ, T., PAVLOVIĆ, V. and POLOMČIĆ, D ...

  • FTIR spectroscopic study оf S-мetolachlor сorption оn inorganic and organically modified montmorillonite from Bogovina

    Lazar Kaluđerović, Zorica Tomić, Jelena Bogosavljević, Ljubomir Životić, Maja Milošević (2021)
    ... of herbicide S-metolachlor with inorganic and organically modified montmorillonite from Bogovina (Boljevac municipality, Serbia). MATERIALS AND ME THODS Materials HDTMA-bromide was obtained from Alfa-Aesar Chemical Company (Karlsruhe, Germany), with a purity of 98%. Phenyltrimethylammonium chloride ...
    ... chloride (PTMA) was supplied by the Tokyo Chemical Industry Company (Toshima, Kita-Ku, Tokyo, Japan), with a purity of 98%. A raw natural sample of bentonite was collected from the Bogovina locality (Serbia). Clay fraction, with montmorillonite as the dominant mineral, was separated using the d ...

  • Energetska bezbednost sektora prirodnog gasa Srbije

    Aleksandar Madžarević, Predrag Jovančić, Miroslav Crnogorac (2023)
    U prve dve decenije 21. veka obezbeđivanje sigurnosti snabdevanja prirodnim gasom domaćeg tržišta bio je jedan od prioriteta razvoja energetike Srbije. Istovremeno, aspekt sigurnog snabdevanja bio je neizostavni deo slagalice stvaranja energetske bezbednosti. Izražena uvozna zavisnost je dominantna karakteristika sektora prirodnog gasa, tačnije, Republika Srbija je snažno zavisna od ruskog gasa, sa više od 80% uvezenih količina gasa, a do pre dve godine snabdevala se isključivo kroz jednu interkonekciju. U radu se razmatra aktuelna situacija u sektoru prirodnog ...
    N-1, IDUPS, energetska bezbednost, sigurnost snabdevanja
    ... various studies and international projects. Since 2001, he owns State professional exam for the performance of workin the exploitation of mineral materials. Miroslav Crnogorac is an assistant professor at the Faculty of Mining and Geology, University of Belgrade. He graduated, completed his master's ...

  • Threshold-induced correlations in the Random Field Ising Model

    Sanja Janićević, Dragutin Jovković, Lasse Laurson, Đorđe Spasojević (2018)
    Multidisciplinary
    ... Examples of such systems stem from earthquakes'*” to neu- ronal networks”, from compression of wood samples! and porous materials**-~4 to deformation and fracture of stressed materials*>-*’, to name just a few. One very important common feature of these systems is that such avalanche-like signals appear ...
    ... Institute of Physics, Department of Applied Physics, Aalto University, P.O. Box 11100, 00076, Aalto, Espoo, Finland. Correspondence and requests for materials should be addressed to L.L. (email: lasse.laurson@aalto.fi) Received: 3 January 2018 Accepted: 22 January 2018 Published: xx xx xxxx OPEN ht ...
    ... Institute of Physics, Department of Applied Physics, Aalto University, P.O. Box 11100, 00076, Aalto, Espoo, Finland. Correspondence and requests for materials should be addressed to L.L. (email: lasse.laurson@aalto.fl) SCIENTIFIC REPORTS | (2018) 8:2571 | DOI:10.1038/s41598-018-20759-6 1 www.nature ...

  • Investigation of quantitative indicators of anisotropy based on longitudinal elastic waves propagation velocities with uncertainty

    Miloš Gligorić, Jelena Majstorović, Suzana Lutovac (2018)
    ... waves b) transversal waves Today, ultrasonic waves with frequency over 20 000 Hz are applied in elastic properties investigations of different materials, both in laboratories and „in situ“ conditions. At the end of the seventies in the last century for rock samples investigation (borehole core, ...
    ... u Beogradu – Rudarsko – geološki fakultet. JASIEHKO J. and STAWISKI B. (2001) Analysis of cracking plane geometry in old sandstone columns. Materials and Structures, 34, pp. 248–252. KAHRAMAN S. (2007) The correlations between the saturated and dry P-wave velocity of rocks. Ultrasonics, 46, ...

  • Adaptive neuro-fuzzy prediction of operation of the bucket wheel drive based on wear of cutting elements

    Filip Miletić, Predrag D. Jovančić, Milos Milovančević, Dragan Ignjatović (2020)
    The capacity of the rotor excavator depends largely on the operation of the subsystem for digging. There is a great contribution to the correct and sharp teeth when the capacity is the highest. In the function of time, the teeth become clogged due to abrasive wear, or changes in their geometric shape. To analyze the bucket wheel drive in depend on wear of the cutting elements in this study adaptive neuro fuzzy inference system (ANFIS) approach was implemented. ANFIS ...
    Pogon rotornog točka, habanje, rezni elementi, ANFIS

  • Analysis of the exhaust emissions inventory from auxiliary mining machines

    Stevan Đenadić, Aleksandar Mirković, Jovana Mitrović, Filip Miletić, Predrag Jovančić, Dragan Ignjatović (2023)
    Open-pit coal mines are equipped with a large number of mining machines and vehicles with diesel engines. Due to common daily operation of these machines and vehicles large amounts of exhaust gases which contain numerous pollutants are emitted into the atmosphere. The demand to reduce air pollution induced the activities in developed countries to map and calculate all gases emitted by industries to formulate and select adequate preventive activities. In collaboration with machine manufacturers, emission standards for off-road machines ...
    emissions, mining, auxiliary machines

  • BEYOND 2020 - Geology explorations and open pit activities affectation in reclamation designing in Kolubara Coal Mines (KCM) Serbia, new considerations

    Bojan Dimitrijević, Bogoljub Vučković, Radmila Gaćina (2023)
    Geology explorations in KCM runs from 1936. year up to these days and still ongoing. Results in >7,200 drill holes with ≈600,000 m of core drilling and gave lignite ore resources of > 4,1Bt, which 1,15Bt are excavated since 1986. of XIX up to early years of XXI century. For further mining operations in open pits stay 1,5Bt of lignite. Under waste heaps are ≈80 km2, additional 85 km2 should be filled. All of that masses/areas were, are ...

  • Application of geophysical and multispectral imagery data for predictive mapping of a complex geo-tectonic unit: a case study of the East Vardar Ophiolite Zone, North-Macedonia

    Filip Arnaut, Dragana Đurić, Uroš Đurić, Mileva Samardžić-Petrović, Igor Peshevski (2024)
    General Earth and Planetary Sciences
    ... units. Materials and methods The materials and methods chapter, and the results and dis- cussion chapter, follow Fig. 3, which displays the research workflow. Data sources, including multispectral satel- lite imaging, geophysical data, and geological data, are described in the materials and methods ...
    ... outcomes in the application of remote sensing for litho- logical mapping of surface occurrences, challenges arise in characterizing geological materials in areas covered with dense vegetation or sediments (Leverington and Moon 2012; Harris and Grunsky 2015; Kuhn et al 2018; Ge et al. 2022). In ...
    ... Science Informatics (2024) 17:1625–1644 Fig.3 Data acquisition, prepa- ration, machine learning model- ling and evaluation workflow 1629 Materials and methods || Data sources • Multispectral satellite imaging data - LANDSAT 7 ETM+ Da ta ac qu is it io n - Band ratio maps • Geophysics ...

  • Study of the Synergetic Effect of Co-Pyrolysis of Lignite and High-Density Polyethylene Aiming to Improve Utilization of Low-Rank Coal

    Ivan Kojić, Achim Bechtel, Nikoleta Aleksić, Dragana Životić, Snežana Trifunović, Gordana Gajica, Ksenija Stojanović (2021)
    Polimeri i plastika, opšta hemija
    ... coal/plastic blends. Namely, hydrocarbon plastic materials, PE, and PP can be the source of hydrogen during the pyrolysis of hydrogen depleted natural products such as coal and biomass. In this way, pyrolysis of mixtures of coal and plastic hydrocarbon materials (co-pyrolysis) results in a balance of carbon ...
    ... lignocellulosic wood flour particles of small (0.07–0.15 mm) and medium size (0.30–0.50 mm) [19]. Recycling of plastics and conversion of polymeric materials into useful products (via pyrolysis, hydrolysis, hydrogenation, and gasification) on the large scale has occurred for more than 25 years. Regarding ...
    ... contribute to the development of cost-effective and environmentally friendly processing of low-rank coal with simultaneous utilization of HDPE waste. 2. Materials and Methods 2.1. Samples The experiments were performed on lignite from the Smederevsko Pomoravlje field (Kostolac Basin, Serbia). A short outline ...

  • Application of machine learning for diagnosing the operation of a deep well pump in oil production

    Maja Trikić (2024)
    This paper will thoroughly examine how machine learning can improve the diagnosis of deep well pumps by analyzing the role and function of the pumps, dynamograms, sensor technologies, and diagnostic methods.Our analysis will provide insights into modern techniques and approaches for enhancing the performance and reliability of oil production systems, targeting cost reduction and increased operational efficiency.
    deep well pump, dynamograms, machine learning, diagnostics of operating coditions,Random Forest, XGBoost
    ... predict and detect faults, enabling timely actions and optimizing pump operation. Through these techniques, feature extraction helps in transforming raw data from dynamometric cards into useful information that can be used to enhance the performance and reliability of pumps.Machine learning involves ...
    ... LEARNING IN SUBMERSIBLE PUMPING ........a e 41 6.1 Sensor fault diagnostics.... 6.2. Condition diagnostics ... 6.3. Application of methods and materials.......aaaaaaaaaaa a naaaanaaaaaaaoi 45 6.3.1. Fundamentals of machine learning........aaaaaa a anaaaaaaaaoi 45 6.3.4. Hyperparameter tuning . ...
    ... that can be processed and displayed. F P= () 30 5.1.2. Types of pressure sensors 1.Piezoelectric sensors- These sensors use piezoclectric materials that generate an electrical voltage when exposed to mechanical stress, such as pressure. Piezoelectric sensors are more suitable for dynamic ...

  • Анализа рада дисконтинуалног система на основу симулације утовара и транспорта целог површинског копа

    Милош Јовановић (2024)
    У овом раду анализира се рад дисконтинуалног система утовара и транспорта на површинским коповима користећи софтверски пакет Haulsim. Циљ истраживања је побољшање ефикасности процеса транспорта и оптимизација коришћења ресурса. Симулација је спроведена за различите сценарије утовара и транспорта, укључујући варијације у броју возила, њиховој брзини, капацитету, као и рутама транспорта. Добијени резултати су показали значајне могућности за унапређење постојећих процедура и смањење трошкова. Дисконтинуални системи су сложени и захтевају пажљиву анализу како би се постигла максимална продуктивност и смањење ...
    анализа, симулација, оптимизација, ефикасност, Haulsim
    ... MojieJt TepeHa lt a a aaaaea a a aaaeaaaa a aaaaaaa a a aataoaaaaatatNoVı 36 Cyka 4.2. Hnirzten naHena Materials — kapakrepHcTHKC JaJIOBHHC ly aaanaaaaaaaakatotı 37 Cuka 4.3. Hnirzejn naHena Materials — kapakrepHcTHKE yrJba al aaaa a aaataaaaaaatNttı 37 Cyka 4.,4. Ilanejt 3a yHoc nmojlaTraKa O TpDa ...
    ... SwellFactor - Loose Densty Bank To Lgader Buccet 125 1.60| vi Bank To Truck Tray 130 1.54| m Close Cnuka 4.2. Hiszneo nanena Materials — kapakmepucmuke Janogune B Materials _ |} x + Properies | Loadzand Haulloading Times _ Load and Camy Loading Times Name Coal - Arthracite. Properties Sand with ...
    ... rparTehHM cJmHKaMa. 36 AHanuaa paja JUHCKOHTHHYy1aJIHOr CHCTeČMa Ha OCHOBy cuMynauuje yroBapa H TpaHciiopTa IIeJIOr IIOBpIIHHCKOT KOIIA B Materials _ a x +-m Properties | Load and HaulLoading Times — Load and Cary Loading Times |___Name Adive || 'Sand with Grave! - Dry Propertes ) Sand with ...

  • The Importance of Detailed Groundwater Monitoring for Underground Structure in Karst (Case Study: HPP Pirot, Southeastern Serbia)

    Marina Čokorilo Ilić, Ana Mladenović, Marina Ćuk, Igor Jemcov (2019)
    Geography, Planning and Development,Aquatic Science,Biochemistry,Water Science and Technology
    ... deeper hydrogeologic system characterized by hypogenic conditions. Water 2019, 11, 603 3 of 10 Figure 2. Geological map of the study area. 3. Materials and Methods Research activities and the selection of methods depended on the operating regime of the water-conveyance tunnel. The campaign lasted ...
    ... Specification, Performance, Production and Conformity, EN 206-1; NSAI: Northwood, Dublin, Ireland, 2002. 14. California Department of Transportation; Materials Engineering and Testing Services; Cossosion Technology Branch. Corrosion Guidelines; The California Department of Transportation: Sacramento, CA ...

  • Geoenvironmental Investigations at a Smelter Location in Bor (Serbia)

    Petar Papić, Zvonimir Milijić, Jana Stojković, Jovana Milosavljević, Maja Todorović, Marina Ćuk, Željko Kamberović (2014)

  • Application of the Fuzzy Model in the Evaluation and Selection of Hydraulic Excavators on Open-Pit Lignite Mine

    Stevan Đenadić, Miloš Tanasijević, Vladimir Milisavljević, Dragan Ignjatović, Predrag Jovančić (2021)
    The production of lignite in large open-pit mines is mainly performed with continuously operating equipment, where bucket-wheel excavators, bucket-chain excavators, belt conveyors, and spreaders are the basic machines. Smaller machines, usually of discontinuous operating nature, are commonly categorized as auxiliary machines. This paper presents the research related to the analysis of auxiliary machine parameters with the case study for a hydraulic excavator. The purpose of the analysis was to develop a model of rating quality of service of the ...
    Fuzzy theory, hydraulic excavator, selection, quality of service, asset management

  • Application of ERT in the study of debris-flow source area: Case study Selanac debris flow

    Dragana Đurić, Jelka Krušić, Biljana Abolmasov (2021)