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125 items

  • Izbor rotornih bagera za proces revitalizacije: primer rotornih bagera SRs 1200 u rudarskom basenu Kolubara

    Predrag Jovančić, Dragan Ignjatović, Stevan Đenadić, Filip Miletić, Goran Todorović, Dragan Novaković (2020)
    Revitalizacija je proces ili skup tehničkih zahvata na mašini kojim se vrši zamena svih dotrajalih ili oštećenih delova metalne konstrukcije. Sastavni deo procesa revitalizacije je i modernizacija zastarele elektro-mašinske opreme. Principi revitalizacije sasvim sigurno nisu sadržani u okviru redovnog godišnjeg ili dnevnog održavanja. Oni predstavljaju održavanje onih veličina koje su značajne za mašinu kao celinu (u ovom slučaju rotorni bager). U ovom radu su analizirani rotorni bageri oznake SRs 1200. Na površinskim kopovima rudarskog basena Kolubara takvih bagera ima ...
    Rotorni bageri, revitalizacija, SRs1200

  • 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)
    ... to the migration into groundwater (Cohen et al., 1986). The reduced inhibitory activity requires repetition of treatment, which leads to increased costs and a negative impact on the environment. Therefore, attempts were made to create a formulation that would lead to an improvement in the inhibitory ...

  • Regional Slope Stability Analysis in Landslide Hazard Assessment Context, North Macedonia Example

    Miloš Marjanović, Biljana Abolmasov, Igor Peshevski, James Reeves, Irena Georgievska (2020)

  • Fuzzy optimization in hydrodynamic analysis of groundwater control systems: Case study of the pumping station “Bezdan 1”, Serbia

    Dragoljub Bajić, Dušan Polomčić (2014)
    A groundwater control system was designed to lower the water table and allow the pumping sta-tion “Bezdan 1” to be built. Based on a hydrodynamic analysis that suggested three alternative solutions, mul-ticriteria optimization was applied to select the best alternative. The fuzzy analytic hierarchy process methodwas used, based on triangular fuzzy numbers. An assessment of the various factors that influenced the selec-tion of the best alternative, as well as fuzzy optimization calculations, yielded the “weights” of the alternativesand the ...
    groundwater lowering, groundwater management scenario, fuzzy analytic hierarchy process,expert knowledge, triangular fuzzy numbers, linguistic variables
    ... eness and flexibility assessed. In the present study, as the number of wells increased, so did capital expendi- ture and operating and maintenance costs. However, it should be noted that in some cases the construction of wells is more economical than the pumping time. Flexibility included the ability ...

  • Towards Better Valorisation of Industrial Minerals andRocks in Serbia—Case Study of Industrial Clays

    Vladimir Simić, Dragana Životić, Zoran Miladinović (2021)
    Management, Monitoring, Policy and Law,Nature and Landscape Conservation
    ... of small thickness, mostly medium or poor quality of raw materials, and underground method of exploitation (Table 3). In addition, high transport costs prevent potential exports, and domestic utilisation is impossible without bentonite processing plants and related industry that would use the final ...
    ... is additionally complicated by the underdeveloped market due to recession in Serbian and surrounding economies and industries, and high transport costs in case of possible export of IMR. Figure 1. Interrelation between the origin of a mineral deposit and economic geology. 4.1. Permitting in Serbia ...

  • Model za optimizaciju graničnog saržaja metala u rudi u funkciji dugoročnog planiranja površinskih kopova

    Daniel P. Kržanović (2016-06-14)
    Optimizacija graničnog sadržaja metala u rudi jedan je od osnovnih koraka u planiranju i dizajniranju površinskih kopova i ima za cilj postizanje maksimalne neto sadašnje vrednosti (NPV). Iz tog razloga, optimizacija graničnog sadržaja i danas je predmet mnogih istraživanja u rudarskoj nauci, sa ciljem rešavanja praktičnih problema u eksploataciji ležišta.Dugoročno planiranje eksploatacije na površinskim kopovima podrazumeva sagledavanje svih relevantih parametara i faktora (geologije rudnog ležišta, tehnologije proizvodnog procesa, kapaciteta otkopavanja i prerade, troškova, cena metala, iskorišćenja i dr) kako ...
    površinski kop, dugoročno planiranje, optimizacija graničnog sadržaja, maksimizacija neto sadašnje vrednosti (NPV).
    ... capacity of mining and processing, costs, metal prices, recovery, etc.) for maximum profit of mining project. By applying various methods and optimization algorithms, which are used today in the modern software tools, it is possible to manage the production costs and revenues or economy of operation ...
    ... optimizaciji graničnog sadržaja u monometaličnim ležištima uvođenjem dve vrste pseudo troškovaa: troškova odlaganja (engl. Delay costs) i troškova promene (engl. Change costs). Whittle je kasnije razvio metodu za optimizaciju graničnog sadržaja, koja predstavlja modifikovanu metodu Lane, i koja je i ...
    ... Cash costs) koji su proporcionalni količini otkopane i prerađene rude. Primer: troškovi goriva, ulja i maziva, guma i dr. 2 ) Troškovi gotovine koji su proporcionalni vremenu. Primer: troškovi održavanja. 3 ) Pseudo troškovi koje nazivamo troškovi odlaganja (kašnjenja) (engl. Delay costs). 4 ...

  • The state and perspective of the natural gas sector in Serbia

    Dejan Ivezić, Marija Živković, Dušan Danilović, Aleksandar Madžarević, Miloš Tanasijević (2016)
    The strategy of long-term energy development of Serbia identifies an increase of share of natural gas in final energy consumption as one of the main aims. Serbia has signed a strategic agreement with the Russian Federation on cooperation in the oil and gas sector, within which the project South Stream pipeline is planned to be realized. In addition, the Republic of Serbia has signed the Treaty that establishes the Energy Community and accepted the obligation to implement the Energy ...
    Consumption, natural gas, scenarios of development

  • Prognoza operativne efikasnosti aktivnog podzemnog rudnika zasnovana na teoriji sivih sistema

    Svetlana M. Štrbac-Savić (2016-06-10)
    Efikasnost predstavlja preduslov za opstanak svake rudarske kompanije, posebno u uslovima izuzetno konkurentnog trţišnog okruţenja kao što je to rudarska industrija. Efikasnost oznaĉava sposobnost kompanije da ispuni svoje kratkoroĉne ili dugoroĉne ciljeve. Operativna efikasnost se definiše kao odnos izmeĊu ulaznih parametara potrebnih za odvijanje proizvodnje i pokazatelja dobijenih proizvodnjom. U kontekstu rudarskog poslovanja, operativna efikasnost se odnosi na vreme potrebno da se mineralno dobro transformiše u novĉana sredstva. Visoka operativna efikasnost se postiţe kada se ostvari prava kombinacija karakteristika ...
    podzemni rudnik, operativna efikasnost, prognoza, teorija sivih sistema, stohastiĉke diferencijalne jednaĉine, simulacija
    ... indirectly associated with the forecasting process. This paper investigates the relationship between ore production rate, fixed costs, revenues, production costs, working days, and degree of use of production capacity, as input variables, and Degree of Operating Leverage (DOL) as indicator of ...
    ... reversion process, normal and uniform distribution. Geometric Brownian motion is used to define future values of production costs. Values of ore production rate, fixed costs, working days, and degree of use of production capacity are estimated by expert‘s knowledge. By simulating a forecasting ...

  • Mechanosynthesis and structural characterization of nanocrystalline Ce1–Y O2– (x=0.1–0.35) solid solutions

    Martin Fabián, Bratislav Antić, Vladimír Girman, Milica Vučinić-Vasić, Aleksandar Kremenović, Shigeru Suzuki, Horst Hahn, Vladimír Šepelák (2015)
    A series of nanostructuredfluorite-type Ce1–xYxO2–δ (0rxr0.35) solid solutions, prepared via highenergy milling of the CeO2/Y2O3mixtures, are investigated by XRD, HR-TEM, EDS and Raman spectroscopy. For thefirst time, complementary information on both the long-range and short-range structural features of mechanosynthesized Ce1–xYxO2–δ, obtained by Rietveld analysis of XRD data and Raman spectroscopy, is provided. The lattice parameters of the as-prepared solid solutions decrease with increasing yttrium content. Rietveld refinements of the XRD data reveal increase in microstrains in the host ceria ...
    Ceria, Yttrium, Solid solution, Mechanosynthesis, Oxygen vacancy, Nanocrystalline material

  • Flood protection and water utilization of karst poljes: example of Gatačko Polje, Eastern Herzegovina

    Tina Dašić, Ljiljana Vasić (2020)
    Earth-Surface Processes,Geology, Pollution, Soil Science, Water Science and Technology, Environmental Chemistry,Global and Planetary Change

  • 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 ...

  • Soil oscillation law parameter determination with the application of Lagrange’s theorem at “Kovilovača“ open pit

    Suzana Lutovac, Nebojša Vidanović, Čedomir Beljić, Zoran Gligorić (2015)
    ... as a method of extraction of mineral raw materials have a growing application with the aim to increase the quantity of blasted mass, and to reduce costs of production as well. Increas- ing the quantity of blasted mass requires the use of large amounts of explosives, leading to an increase in the negative ...

  • The application of ArcGIS for assessing the potential of solar energy in urban area: The case of Vranje

    Boban Pavlović, Milica Pešić-Georgiadis (2019)
    In order to determine the solar energy potential for a specified location, it is crucial to consider the latitude, altitude, slope, terrain morphology, atmospheric conditions, etc. Such a complex calculation and mapping of solar energy can be done using the ArcGIS geoprocessing tool, named Area Solar Radiation (ASR). By using the ASR tool, supported with the adequate input data, it is possible to calculate the maximum solar radiation energy (irradiation) for a defined area and for a specified time ...
    Obnovljivi izvori energije, potencijal solarne energije, GIS, mapiranje solarnog potencijala
    ... environmental impact, show low levels of development. The utilization of other renewable sources of energy, such as wind, solar, and geothermal, is marginal (Lewis M., 2018). The estimated potential can have a considerable contribution to the lesser utilization of fossil fuels, as well as the i ...
    ... measured data from the meteorological stations. Such data can provide better precision in the evaluation of the solar energy potential. However, high costs of installation and maintenance of the meteorological stations promoted the development of ##different methods to estimate the global solar irradiation ...

  • Open Educational Resources in Serbia

    Ivan Obradović, Ranka Stanković, Marija Blagojević, Danijela Milošević (2020)
    Open educational resources, BAEKTEL, Metadata portal
    ... will be assigend by editors. OPEN EDUCATIONAL RESOURCES IN SERBIA 21 learning materials, effective assessment) while managing the associated costs through increased use of resource-based learning (Butcher, 2011). The transformative educational potential of OER revolves around three related ...

  • 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
    ... products and are positioned as leading importers on the world stone market. The high production and processing capacities, along with low labour costs, in countries such as China, India, Brazil, or South Korea, are out-competing the local stone industries of other countries with a wide range of ...

  • Remedijacija otpadnih voda Rudnika prirodnim zeolitom

    Igor Veličković (2024)
    U radu je razmatrano prečišćavanje otpadnih flotacijskih voda sa područja rudnika Rudnik prirodnim zeolitskim tufom sa planine Jastrebac. Prečišćavanje otpadnih flotacijskih voda sa područja rudnika Rudnik prirodnim zeoliskim tufom sa obronaka planine Jastrebac pokazala se veoma efikasnom. Naime, u tri otpadne flotacijske vode utvrđen je povišen sadržaj arsena, hroma, gvožđa, mangana, kao i nikla. Jednostavnim tretmanom zeolitskim tufom iz ovih voda uklonjeni su svi ovi elementi. Sadržaji gvožđe i mangana su sniženi od 95 do 99 %, dok su ...
    flotation waste water, zeolite tuff, purification
    ... was surface modified. In this final work, preference is given to natural zeolitic tuff, because apart from exploitation, there are no additional costs for separation and/or modification, and the efficiency of removing. toxic elements is quite satisfactory. Key words: /flotation waste water, zeolite ...

  • Multiple-Criteria Decision-Making in Mine Development Planning

    Sanja Bajić (2023)
    The Borska Reka ore deposit is an experimental location where developed methodologies have been applied. It is the largest ore body within the Bor mining complex, which has been the subject of numerous studies and analyses for more than three decades. The paper focuses on the application of FAHP and the VIKOR method to address ranking of alternatives and select the optimal mining method by means of fuzzy multicriteria optimization.

  • Assessments of effects of implementation of strategic plans for development of Belgrade District heating system

    Dejan Ivezić, Marija Živković, Aleksandar Madžarević, Miodrag Grujić (2020)
    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 ...
    Daljinsko grejanje, LEAP, Primarni energetski faktor, Uvozna zavisnost, CO2 emisija

  • Damage quantification of built stone on Dark Gate (Belgrade, Serbia): sample of damage index application for decay rate evaluation

    Maja Franković, Nevenka Novaković, Vesna Matović (2015)
    The Dark Gate is the monument of culture, part of the cultural and historical complex of the Belgrade Fortress. It is constructed of limestone blocks that after 270 years of exposure to environmental conditions and different anthropogenic influences show wide ranges of decay forms. During 2007, detail registration of all built limestone microfacies and weathering forms was done using tools of monument mapping. A correlation scheme ‘‘intensity– damage category’’ was made according to the type, intensity, and distribution of ...
    Krečnjak, mapiranje, Indeks raspadanja, brzina raspadanja, progresija
    ... stone block on the monument, quantity of conservation material needed to carry out necessary conservation-restoration treatment, as well as the costs of intervention could be more precisely assessed. Among 409 immovable cultural monuments established in Belgarde, Belgrade fortress is one of ...

  • 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