Претрага

Упит dcterms_subject_txt:mechanical extraction methods,

567 items

  • Metodologija proračuna sanacije klizišta šipovima

    Slobodan Ćorić, Dragoslav Rakić, Stanko Ćorić, Dušan Berisavljević (2022)
    Klizišta u Srbiji, u najvećem broju slučajeva, jako zavise od geoloških uslova u terenu i svako klizište ima svoje specifičnosti koje moraju da se odrede geotehničkim istraživanjima. Stoga su u radu prvo prikazane osnovne karakteristike klizišta u Srbiji, kao i postupci njihovog istraživanja. Zatim su prikazani proračuni sanacije klizišta vertikalnim šipovima. Metodologija proračuna je složena, jer podrazumeva interakciju klizišta i stabilizirajućih šipova. Prilikom određivanja bočne otpornosti tla oko šipova koristi se metoda Brinč Hansena koja uzima u obzir trodimenzionalne ...
    klizišta, geotehnička istraživanja, bočna nosivost šipova, interakcija klizišta i šipa, analiza stabilnosti

  • Просторна анализа епикарста у оквиру карстног система источног дела Суве планине

    Бранислав Петровић, Зоран Стевановић, Вељко Мариновић, Снежана Игњатовић (2022)
    Епикарст представља највиши део стенске масе који је изложен карстификацији, при чему су главне карактеристике епикарста акумулирање подземне воде и стварање услова за формирање концентрисаних токова у подини ове зоне. У досадашњој пракси истраживања епикарста углавном су коришћене индиректне методе: даљинска детекција, анализа хидрограма карстних врела, хидрохемијске и изотопске анализе, па чак и опити трасирања, док је са друге стране јако мали број истраживача изучавао епикарст директним теренским истраживањима. У раду je приказана иновирана методологија истраживања епикарста, која користи ...
    епикарст, даљинска детекција, геоелектрична истраживања, Сува планина

  • Analiza uslova formiranja oticaja reke Resave (istočna Srbija)

    Vesna Ristić Vakanjac, Marina Mitrašinović, Veljko Marinović, Saša Milanović, Ljiljana Vasić, Branislav Petrović, Petar Vojnović (2023)
    Reka Resava zbog veličine sliva i količine vode koju daje Velikoj Moravi predstavlja jednu od najznačajnijih njenih desnih pritoka. U okviru njenog sliva jasno se izdvajaju gornji, geomorfološki raznolik deo sliva, koji je uglavnom izgrađen od karbonatnih sedimenata, i donji deo koji pripada Velikomoravskom basenu. Proticaj reke Resave se beleži u profilima Manastir Manasija koji kontroliše gornji deo sliva u iznosu od 358 km2 i Svilajnac, koji se nalazi na oko 3.5 km pre njenog ušća i koji kontroliše ...

  • Analysis and visualization of geophysical well-logging data from closely spaced boreholes

    Branislav Sretković, Ivana Vasiljević, Dimitry Sidorov - Biryukov (2024)
    Geophysical logging measurements for determining the condition of the rock mass on the dam profile and locating the predisposed directions of water circulation and loss from the reservoir were conducted in four boreholes distributed at a close distance. The survey was carried out in a typical karst terrain, which is an additional challenge for defining the geological model, especially in terms of water retention. That kind of data set provides an excellent opportunity for a new approach to analysis ...
    well-logging in karst, water loss, data correlation, data fusion
    ... the degree of karstification of underlying carbonate rocks (Hussain et al., 2020). Compared to some other geophysical methods (primarily electrometric and seismic methods), which are standardly used in projects to solve the problem of water losses from reservoirs, geophysical well logging ...
    ... greatest loss of water takes place under the very body of the 100 concrete gravity dam, up to the depths that conventional surface geophysical methods cannot reach. Analysis of the standard geophysical logging data provided significant insight into the state of the rock mass under the dam body ...
    ... their detection and determination of their character in terms of predisposition to water circulation is a key task of geophysical surveys. METHODS OF INVESTIGATION Analyzed data set consisted of four logs: spontaneous potential (SP), long-normal resistivity (Ln), short-normal resistivity ...

  • Development of the Cost-Based Model for Monitoring the Lifetime of the Earth Moving Machines

    Ugljesa Bugarić, Milos Tanasijević, Stevan Djenadić, Dragan Ignjatović, Ivan Janković (2022)
    This paper presents the model for the identification of reference points on the lifetime curve of engineering systems. This curve commonly represents the increase and decline of failure in relation to time. A direct correlation between failure rate and costs is assumed in this paper, therefore, statistical and empirical analysis of costs provided reference points. This approach is used for positioning stages of the engineering system’s lifetime with a minimal number of failures and costs, regardless of whether these ...
    Electrical and Electronic Engineering,Industrial and Manufacturing Engineering, Control and Optimization, Mechanical Engineering, Computer Science (miscellaneous), Control and Systems Engineering

  • Hydrochemical indicators of groundwater flow in the area of “Čukaru Peki” Cu-Au underground mine in eastern Serbia

    Nebojša Atanacković, Vladimir Živanović, Jana Štrbački, Veselin Dragišić, Ivana Cvejić (2022)
    The physical and chemical properties of groundwater, together with the groundwater levels regime and rock hydraulic properties, are often used to understand and conceptualize the hydrogeological system. Prediction of the influence of mining works on groundwater, and vice versa, is a challenge due to significantly altered groundwater flow patterns in the raw materials exploitation areas in relation to natural conditions. Therefore, multiple parameters are assessed and monitored before and during exploitation to properly characterize and quantify the system for ...
    mine water, hydrogeology, multivariant statistics, groundwater inflow, water quality

  • Sitni, ali bitni: uloga sitnih sisara, herpetofaune i mekušaca u rekonstrukciji pleistocenskih paleosredina

    Katarina Bogićević, Draženko Nenadić, Dragana Đurić, Mihajlo Jovanović, Aleksandra Savković (2023)
    Fosilni ostaci životinja i biljaka imaju važnu ulogu u rekonstrukciji pleistocenskih paleosredina. U ovom radu opisan je značaj tri grupe životinja: sitnih sisara, herpetofaune I mekušaca. Mada je za rekonstrukciju važan sastav čitave asocijacije, nalasci pojedinih vrsta mogu biti dovoljno indikativni da otkriju tip staništa ili klimatske uslove. Posebnu teškoću pri rekonstrukciji paleosredina u Srbiji predstavlja činjenica da klimatske promene na Balkanskom poluostrvu nisu bile tako oštre kao u srednjoj i zapadnoj Evropi, pa ne postoji drastična razlika u ...
    ... interpret the palaeoecological conditions of the researched area using different methods. Each of the described methods has its advantages and disadvantages. Therefore, it is useful to combine different types of methods for greater accuracy. Acknowledgement: This work was funded through the NEEMO ...
    ... of Serbia. 2. Kongres geologa Bosne ı Hercegovine, Zbornik radova 6, knjiga sažetaka, Laktaši 2-4. oktobar, 173-177. 7. Ratnikov, V.Yu., (1996): Methods of Paleogeographic reconstructions based up on fossil remains of amphibians and reptiles of the Late Cenozoic of the East European platform. Pal ...
    ... example, colder periods are characterized by a wider distribution of steppe species, while in warmer periods forest dwellers are more common. Methods of reconstruction: The simplest and at the same time the most frequently used method for habitat type reconstruction is the method of ecological ...

  • Vulnerability Assessment as a Basis for Sanitary Zone Delineation of Karst Groundwater Sources—Blederija Spring Case Study

    Vladimir Živanović, Nebojša Atanacković, Saša Stojadinović (2021)
    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 Бледерија

  • 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
    ... activities do not end with the extraction of mineral resources. Rehabilitation represents an integral part of mining activity and mines operators are required under law to rehabilitate excavated sites. The surface affected mining must be rehabilitated as soon as the extraction work permits. Recultivation ...

  • Флотабилност халкопирита из полиметаличне руде рудника „Рудник”

    Ђурица Н. Никшић (2022)
    The doctoral dissertation Chalcopyrite flotability from polymetallic "Rudnik" mine ore consists of two parts. The first part is a general part in which the theoretical foundations of the flotation concentration process, the flotation properties of chalcopyrite, the influence of certain flotation reagents and the mechanism of action on the flotation properties of chalcopyrite are presented. This part also describes the process of flotation concentration of polymetallic ore from the "Rudnik" mine. The second part is ...
    Халкопирит, флотацијска концентрација, KAX, NaCN, pH пулпе

  • Pregled hidrodinamičkih istraživanja bunara sa horizontalnim drenovima numeričkim metodama

    Đorđije Božović, Dušan Polomčić, Dragoljub Bajić (2020)
    U radu je predstavljen pregled odabranih hidrodinamičkih istraživanja realizovanih primenom numeričkih metoda simulacije kretanja podzemnih voda pod uticajem rada bunara sa horizontalnim drenovima. Na osnovu pristupa u matematičkom i hidrauličkom tretiranju, kao i numeričkoj simulaciji bunara sa horizontalnim drenovima na modelima, predstavljeni su najznačajniji aspekti izrade hidrodinamičkih modela ovog kompleksnog tipa vodozahvatnog objekta. Metodologija obuhvata izbor: a) graničnih uslova za simulaciju prirodnih granica, izvora prihranjivanja i dreniranja izdani; b) primenjivanog stepena diskretizacije prostora obuhvaćenog modelom u planu i profilu; ...
    horizontalni bunari, hidraulika bunara, analitički modeli, numerički modeli, hidrodinamičko modeliranje podzemnih voda

  • Дефинисање археолошких објеката на локалитету Кремените њиве применом Ојлерове 3Д деконволуције на магнетометријске податке

    Весна Цветков, Илија Васиљевић, Бранислав Сретеновић, Весна Дамњановић (2018)
    ... RESULTS AND DISCUSSION    Testing  Standard and  Located O3DD on  synthetic data has  shown  that both methods  succes‐ sfully determine the depths to the sources. For shallow sources, both methods give good results, except  that O3DD Locator gives the exact positions of the edges of the source, whi ...
    ... ctrical resistance were used, while in the  fifties also started the magnetic measurements for the same purpose. The frequent use of geophysical  methods in archeology has encouraged the development of the techniques of research, data processing  and  interpretation of  results, which  led  to a new ...
    ... olution  (O3DD) was used on  magnetic data. In order to get the best input parameters, O3DD testing was first performed on synthetic  models.  METHODS    Magnetic measurements are based on the measurement of the Earth's magnetic field. The unit  is Tesla T, but as this unit  is great for application ...

  • 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

  • Postojeće stanje i budući trendovi u preventivnoj zaštiti podzemnih voda Srbije

    Vladimir Živanović (2022)
    Podzemne vode predstavljaju osnovni, a u mnogim zemljama i jedini resurs za javno vodosnabdevanje stanovništva tako da zaštita podzemnih voda predstavlja bitan preduslov za njihovo dugotrajno i održivo korišćenje. Kako u svetu, tako i u Srbiji, zaštita podzemnih voda se najvećim delom svodi na primenu preventivnih mera zaštite. Kod planiranja zaštite većih prostora sve više se koriste metode za ocenu ranjivosti podzemnih voda. Njihova primena je posebno naglašena u karstnim područjima zato što se tu izdvajaju delovi terena sa ...
    Zaštita podzemnih voda, karte ranjivosti podzemnih voda, karta hazarda, karte rizika od kontaminacije, monitoring podzemnih voda, Srbija

  • Regionalna karakterizacija karstnih podzemnih voda dela centralnog Balkana u funkciji njihovog održivog korišćenja i menadžmenta

    Veljko J. Marinović (2022)
    Karstne podzemne vode koristi oko 700 miliona ljudi na svetu, čime je njihov značaj za svetsko stanovništvo nemerljiv. U sklopu doktorske disertacije vršena su istraživanja i analize karstnih sistema dela centralnog Balkana (Srbije, Crne Gore i Savskog sliva Bosne i Hercegovine), kako bi se evaluirao ovaj dragoceni resurs. Analize su vršene na primerima karstnih sistema vrela Perućac, Seljašnica, Mokra i Mlava (Srbija), Oko Bijele i Rijeka Crnojevića (Crna Gora) i vrelo Bosne (Bosna i Hercegovina), kao i na regionalnom ...
    karstni sistem, podzemna voda, pritisci na kvantitet i kvalitet, menadžment podzemnih vodnih resursa

  • Determination of the groundwater-leakage mechanism (binary mixing) in a karstic dam site using thermometry and isotope approach (HPP Visegrad, Bosnia, and Herzegovina)

    Ljiljana Vasić, Saša Milanović, Anita Puskás-Preszner, Laszlo Palcsu (2020)
    Earth-Surface Processes,Geology, Pollution, Soil Science, Water Science and Technology, Environmental Chemistry, Global and Planetary Change

  • 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
    ... research, and it is found very suitable in different parts of fluid mechanics. Its main difference from other most used methods like finite element and finite difference methods, is in absence of numerical grid, and while mass is presented with particles of solid and fluid phase. Each particle has ...
    ... Aspects’’. Arch Computat Methods Eng 22, 67–104. Pastor, M., Haddad, B., Sorbino, G., Cuomo, S., and Drempetic, V. (2009). ‘’A depth integrated, coupled SPH model for flow-like landslides and related phenomena’’. International Journal on Numerical Analysis and Methods in Geomechanics, 33(2): ...
    ... of the fluid phase can be neglected, the stress tensor in the mixture can be decomposed into a ‘pore pressure’ and an effective stress, and the mechanical behavior of the mixture can be described by a system of differential equations governing the dynamics of each of the phases as well as the coupling ...

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

    Jelena Ratković, Dušan Polomčić, Dragoljub Bajić, Bojan Hajdin (2016)
    ... Conference on Sustainable Development of Energy Water and Environmental Systems. Ohrid, Republic of Macedonia, 01-07 July, 2012. Zagreb: Faculty of Mechanical Engineering and Naval Architecture, pp. 236-237. POLOMČIĆ, D. et al. (2013a) Multiannual effects of Peštan source operation in the function ...
    ... World War II, it has produced more than 580,000,000 tons of coal. Every other kilowatt in Serbia comes from KCB’s lignite (brown coal). A daily extraction rate of as much as 100,000 tons of coal ensures reliable operation of the thermal power plants Nikola Tesla and Veliki Crljeni. KCB has been ...
    ... recharge and discharge in the form of model inflow and outflow. Given that there is a groundwater control system in place, the rate of groundwater extraction is greater than the rate of aquifer recharge (422.78 l/s vs 452.15 l/s). Analysis of the boundary conditions of the hydrogeologic system included ...

  • Crystallography and Surface Oxidation of Stoichiometric Arsenopyrite from Šumadija-Kopaonik Pb-Zn/Polymetallic Ore District (Serbia)

    Ivana Jelić, Aleksandar Pačevski, Aleksandar Kremenović, Aleš Šoster, Andreja Šestan, Janez Zavašnik (2023)
    The behaviour and stability of arsenopyrite largely depend on its crystal structure, but studies of crystallography and structural defects are scarce. For clarification, we investigated a series of natural arsenopyrite crystals from the polymetallic Pb-Zn-(±Cu,Ag,Au,Sb,Bi,W) Šumadija-Kopaonik ore district (Serbia) by powder X-ray diffraction (XRPD). Among them, samples from the Drenjak gold mineralisation showed near-stoichiometric FeAsS composition and were further investigated by conventional and high-resolution transmission electron microscopy methods. TEM revealed abundant planar crystallographic defects and epitaxial surface oxide layer ...
    Inorganic Chemistry, Condensed Matter Physics,General Materials Science, General Chemical Engineering, crystal structure, FeAsS, oxidation, TEM, XRPD
    ... showed near-stoichiometric FeAsS composition and were further investigated by conventional and high-resolution transmission electron microscopy methods. TEM revealed abundant planar crystallographic defects and epitaxial surface oxide layer formation upon air exposure. Our findings present the ...
    ... samples from (c) Drenjak and (d) Sastavci locations, the latter showing visible zoning due to non-homogenous chemical composition. 2. Materials and Methods The mineralised samples and ores from the Šumadija-Kopaonik ore district were sampled in the last twenty years during several field excursions ...
    ... monoclinic P2,/c [9] 5.7612 5.6841 5.7674 111.721 175.456 monoclinic P2,/c TEM study 5.75 5.68 5.76 1115 175.03 monoclinic P2/c Further, the TEM methods allow for obtaining convergent beam electron diffraction (CBED) patterns for further insight into the crystal structure and direct microscopic obser- ...

  • 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
    ... precise information can be expen- sive to obtain. Proposed for future study are other multicriteria optimization methods and decision-mak- ing approaches, to compare several different methods and present the results in parallel. The FAHP analysis used in the present study can be recommended for other fields ...
    ... decision- making concept that integrated the fuzzy theory with the analytic hierarchic process. Additionally, CHANG et al. (2003) introduced statistical methods to FAHP, for selecting the criterion that affected the end result (i.e. selection of alternative). Among the FAHP approaches mentioned above, the ...
    ... the weight priority vectors are defined as follows: Step 5. The ultimate values of the weights are ob- tained applying one of the normalization methods: • The additive normalization method (SAATY 1980), or • The weighted least squares method (CHU et al. 1979), the logarithmic least squares method ...