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Упит dcterms_subject_txt:Earth-Surface Processes

362 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

  • 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
    ... obtain efficient communication between the symbolic and the numerical part of the system. In order to cope with this problem a separation of processes in coupled systems into independent modules is suggested. Furthermore, information interchange, i.e. communication among modules is strictly ...

  • Crystal structure of K3EuSi2O7

    Sabina Kovač, Predrag Dabić, Aleksandar Kremenović (2021)
    alkalni silikati elemenata retkih zemalja, kristalna struktura, sinteza metodom fluksa, rendgenska difrakcija na monokristalu
    ... them. Silicates containing the larger rare earth elements usually crystallize in a structure that contains the rare-earth cation in both a slightly distorted octahedral and an ideal trigonal prismatic coordination environment. Keywords: alkali rare-earth silicates; crystal structure; flux synthesis; ...
    ... (Received 18 February; Revised 15 March 2021; Accepted 31 March 2021) Abstract: As a part of the research of the flux technique for growing alkali rare- earth elements (REE) containing silicates, tripotassium europium disilicate, K3EuSi2O7, has been synthesized and characterized by single-crystal X-ray ...
    ... synthesis; single- crystal X-ray diffraction. INTRODUCTION Silicates containing rare-earth elements (REE silicates) are the subject of intense research in recent decades. Many studies were performed on REE silicates because of a wide range of optical and magnetic properties combined with high thermal ...

  • Rock slope stability analysis under Hoek–Brown failure criterion with different flow rules

    Svetlana Melentijević, Zoran Berisavljević, Dušan Berisavljević, Claudio Olalla Marañón (2024)
    The stability analysis of homogeneous rock slope following the Hoek–Brown failure criterion under the hypothesis of different flow rules is performed based on limit equilibrium and finite element methods. The applied failure criterion is the generalized Hoek–Brown that can be introduced as a shear/normal function in analysis applying different flow rules. The results are compared with those obtained by the application of equivalent shear strength parameters of the Mohr–Coulomb criterion, considering that this is still the most widely used ...
    Kružna klizna površ, Huk-Braunov kriterijum loma, Kriterijum popuštanja, Smičuća/normalna funkcija, Nivo napona, Verovatnoća i parametarska analiza

  • Razvoj integralnog modela za optimizaciju diskontinualnog sistema proizvodnje na površinskim kopovima nemetala

    Miodrag Čelebić (2024)
    Izbor optimalne mehanizacije u diskontinualnom sistemu transporta je jedna od najvažnijih odluka koju treba donijeti prilikom projektovanja površinskih kopova. Pri izboru optimalne mehanizacije, uticaj ima veliki broj faktora, kako prirodnih – geoloških i ekoloških, tako i tehničkih, ekonomskih i socijanih. Neki od njih se mogu izraziti numerički, u određenim mijernim jedinicama, a neki opisno, lingvističkim varijablama, shodno uslovima koji vladaju na rudnim ležištima, a koje karakterišu visok stepen neizvjesnosti i neodređenosti kako prilikom istraživanja, tako i tokom procesa eksploatacije ...
    izbor mehanizacije, tehnologija eksploatacije, diskontinualani sistem, ekspertsko odlučivanje, lingvističke varijable, MCDM, FAHP

  • Development of Open Educational Resources (OER) for Natural Language Processing

    Cvetana Krstev, Biljana Lazić, Ranka Stanković, Giovanni Schiuma, Miladin Kotorčević (2015)
    In this paper we present the development of an online course at the edX BAEKTEL platform named “Lexical Recognition in the Natural Language Processing (NLP)”. It is based on the course of the same name for PhD studies at the University of Belgrade, Faculty of Philology. There are not many courses in Computational Linguistics (CL) on OER platforms, and there is none in Serbian either for CL or NLP. We have developed this course in order to improve this ...
    E-Learning, Open Educational Resources, Computational Linguistics, Lexical Resources, edX
    ... principle of connecting the theory and practice is fulfilled by using the video tutorials. These tutorials are designed to present practical use of processes described in theoretical parts of lessons. Video tutorials are made by recording content of the screen and instructors voice. We concluded ...

  • Грешка инклинације код депозиционе реманетне магнетизације

    Mirko Petković, Vesna Cvetkov (2019)
    ... average remanence anisotropy of its individual magnetic particles, and correct for paleomagnetic inclination shallowing, Physics and Chemistry of the Earth 27, 1273 – 1279. 5. Jackson, M., Banerjee, S., Marvin, J., Lu, R., & Gruber, W., (1991) Detrital remanence, inclination errors, and anhysteretic ...
    ... rock complexes. The spatial position of the remanent magnetization vector is determined by the paleo declination and inclination. However, the processes of re-deposition, compaction and cementation of sediments lead to the deviation of the inclinations value from one that the sediments acquired during ...

  • 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
    ... of geothermal energy is radioactive decay that evolves within the planet some 6730 km under the surface. The Earth's crust is comparatively cold, except for the hot spots where magma is nearer the surface, and grows warmer with the depth. As to the utilization of the planet's heat, the efficiency of ...
    ... Solution of a mineral in ground- water, which mainly contains silicon, provides information about the temperature condition in rocks at which processes occur or have occurred in the past. Experiments have substantiated that solubility of a mineral depends on temperature; it is proportional with the ...

  • 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

  • Production of electricity from coal-fired power plants and accompanying CO2 emissions: comparison of EU-27 and US

    Uroš Djorgovski, Aleksandar Madžarević, Predrag Jovančić (2023)
    Even in the third decade of the 21st century, large power plants are still responsible for more than half of the electricity production in Europe and US. They predominantly use fossil fuels in their work, which results in the emission of pollutants into the air, soil and water. In addition to the production of electric energy, fossil fuels, including coal, are used for industrial purposes. Although the use of coal, especially in the countries of the European Union, is ...
    CO2, емисија, угаљ, термоелектрана, САД, ЕУ-27
    ... comfort in performing daily activities with an increasingly obvious pressure on the systematic reduction of the impact on the environment in the processes of production, transformation, and consumption of electricity. Total global energy-related greenhouse gas emissions rise by about 1% to a record ...

  • Konceptualni model hidrogeotermalnog sistema šire okoline Brusa - geološki, geofizički i hidrogeološki uslovi / Conceptual model of hydrothermal system of Brus area - geological, geophysical and hydrogeological condition

    Dejan Milenić, Ana Vranješ, Marinko Toljić, Ivana Vasiljević, Natalija Radosavljević, Matija Ognjanović (2024)
    Na širem području Brusa izvedena su naučna multidisciplinarna istraživanja za potrebe ocene geotermalnog potencijala sa zadatkom de9inisanja uslova formiranja geotermalnih i termomineralnih resursa. Interpretacijom podataka zaključeno je da je na predmetnom terenu formiran "hibridni" hidrogeotermalni sistem, koji sadrži elemente sistema u rov-strukturi i elemente konvektivnog hidrogeotermalnog sistema sa rezervoarom u pokrivaču granitoidne intruzije. Sistem čine dva nezavisna hidrogeotermalna rezervoara. Prvi rezervoar formiran je u gornjokrednim krečnjacima na dubini od oko 1550 m. Maksimalne prognozne temperature hidrogeotermalnih resursa u krečnjačkom ...
    hidrogeotermalni sistem, gornjokredni krečnjaci, trijaski mermeri, Brus

  • Prirodno prečišćavanje i stimulisana bioremedijacija podzemnih voda zagađenih naftnim ugljovodonicima

    Nenad M. Marić (2016-09-26)
    Disertacija se konceptualno sastoji iz dva dela kojima je obuhvaćen pasivan (prirodnoprečišćavanje) i aktivan remedijacioni pristup (stimulisana bioremedijacija) kodpodzemnih voda zagađenih naftnim ugljovodonicima.U prvom delu disertacije prikazani su rezultati osmatranja procesa prirodnogprečišćavanja u podzemnim vodama na lokaciji istorijskog zagađenja kerozinom.Tragovi zagađenja naftnim ugljovodonicima pronađeni su 20 godina nakon prosipanjakerozina. Ovo je stvorilo osnovu za proučavanje efekata dugotrajne izloženostipodzemnih voda procesima biodegradacije u terenskim uslovima. Uočeno je da sesnižene koncentracije elektron akceptora (O2, NO3-, SO42-) i povišene koncentracijemetaboličkih produkata biodegradacije ...
    podzemne vode, naftni ugljovodonici, kerozin, prirodno prečišćavanje,stimulisana bioremedijacija
    ... attenuation processes at a site of historical contamination by kerosene are presented. Traces of petroleum hydrocarbon contamination were found 20 years after the kerosene spill. This provided a basis for the monitoring of long term groundwater exposure to biodegradation processes in field conditions ...
    ... g postupka u našoj zemlji. Rezultati primene stimulisane bioremedijacije podzemnih voda na ovoj lokaciji publikovani su u časopisu Environmental Earth Sciences (Marić et al., 2015). 4.2.1. Opšte karakteristike područja istraživanja Fabrika tekstila "Nitex" nalazi se na rečnoj terasi, uz ...
    ... (2015) Enhanced in situ bioremediation of groundwater contaminated by petroleum hydrocarbons at the location of the Nitex textiles, Serbia. Environ Earth Sci (2015) 74, 5211–5219. 85. Marković B, Urošević M, Pavlović Z, Terzin V, Jovanoviž Ž, Karović J, Vujisić T, Antonijević R, Malešević M, Rakić ...

  • Selection of Artificial Lift Methods: A Brief Review and New Model Based on Fuzzy Logic

    Miroslav Crnogorac, Miloš Tanasijević, Dušan Danilović, Vesna Karović Maričić, Branko Leković (2020)
    Artificial lift methods have applications in oil wells where oil production is no longer possible due to natural reservoir energy, so this necessary energy is added by introducing lift methods. In order to achieve optimum production, the selection of an artificial lift method is very important. This paper uses fuzzy logic as a mathematical and conceptual model for selection of the optimal artificial lift method. The outcome or IF-THEN rules, as the central part of the model, is based ...
    mehaničke metode, proizvodnja nafte, fazi logika, donošenje odluka, optimizacija
    ... direction and j in a circular direction. Each of the five commonly used methods (GL, ESP, SRP, HP, PCP) defines a specific surface that is standard. The level of overlapping the surface, which represents the result for the new well and some of the standard surfaces, represents the level of applicability ...
    ... direction and j in a circular direction. Each of the five commonly used methods (GL, ESP, SRP, HP, PCP) defines a specific surface that is standard. The level of overlapping the surface, which represents the result for the new well and some of the standard surfaces, represents the level of applicability ...
    ... their center of mass with standard deviation. The first presented method gives results in percentage of surface overlapping for 5 oil exploitation method in comparison with new well resulting surface. The second method gives results that involves the center of mass (weighted mean of maximum) and Energies ...

  • Differently shaped nanocrystalline (Fe, Y)3O4 and its adsorption efficiency toward inorganic arsenic species

    Biljana P Dojčinović, Boštjan Jančar, Lotfi Bessais, Aleksandar Kremenović, Nataša P Jović-Jovičić, Predrag T Banković, Dalibor M Stanković, Miloš Ognjanović, Bratislav V Antić (2019)
    Herein we report effects of partial substitution of Fe3+ by Y3+ in magnetite (Fe3O4) on morphology and inorganic arsenic species adsorption efficiency of the Fe3−xYxO4 nanoparticles formed. The series of Fe3−xYxO4 (x=0.00, 0.042 and 0.084, labeled as Y00, Y05 and Y10, respectively) was synthesized using co-precipitation followed by microwave-hydrothermal treatment (MW) at 200°C. With increase of yttrium content(xvalue), both the morphological inhomogeneity of the samples and the fraction of spinel nanorods as compared to spinel pseudospherical particles increased. By ...
    microstructure, microwave-hydrothermal synthesis, adsorption, magnetic nanoparticles, arsenic

  • Age and microfacies of oceanic Upper Triassic radiolarite components from the Middle Jurassic ophiolitic mélange in the Zlatibor Mountains (Inner Dinarides, Serbia) and their provenance

    Hans-Juergen Gawlick, Nevenka Đerić, Sigrid Missoni, Nikita Bragin, Milan Sudar, Divna Jovanović (2017)
    Neo-Tethys, trench-like basins, synorogenic deposition, evolving thrust belt, Triassic palaeogeography
    ... St. 6, P.O.Box 62, 11120 Belgrade-35, Serbia 3Geological Institute, Russian Academy of Sciences, Pyzhevsky 7, 119017 Moscow, Russia “Centre of Earth Sciences, University of Vienna, Althanstr. 14, 1090 Vienna, Austria ŠSerbian Academy of Sciences and Arts, Knez Mihaila 35, 11000 Belgrade, Serbia ...
    ... of the Republic of Serbia, Project ON-176015 (NDJ, MS, DJ). The cooperation Leoben-Belgrade was sup- ported by the CEEPUS Network CIII-RO-0038 Earth-Science Studies in Central and South-Eastern Europe. The research work of N. Bragin was supported by Russian Governmental Assignment no. 0135 ...
    ... of Late Triassic distal periplatform limestones from the Northern Calcareous Alps (Kiilberstein Quarry, Berchtesgaden Hallstatt Zone). /nt. J. Earth Sci. 80, 108—129. Gawlick H.-J. & Frisch W. 2003: The Middle to Late Jurassic carbo- nate clastic radiolaritic flysch sediments in the Northern ...

  • Hidrogeohemija prirodnih radioaktivnih elemenata u podzemnim vodama Srbije

    Marina D. Ćuk (2018-02-23)
    Osnovni cilj doktorske disertacije predstavljao je definisanje prirodnih koncentracija (engl. background values) U, Th, i K u podzemnim vodama, i definisanje hidrogeohemijskih uslova koji utiču na distribuciju navedenih elemenata u podzemnim vodama...
    prirodni radioaktivni elementi, podzemna voda, geohemijske sredine, hidrogeohemijski uslovi, neparametarska statistička analiza, logistički model, hidrohemijsko modeliranje
    ... Compounds. The Actinide Aqueous Inorganic Complexes. IAEA, Wien. 49. Garven G. 1995. Continental-Scale Groundwater Flow and Geologic Processes. Annual Review of Earth And Planetary Sciences 23: 89 – 118. 50. Goldscheider N, Mádl-Szőnyi J, Erőss A, Schill E. 2010. Review: Thermal water resources ...
    ... Sciences and Arts, Belgrade, pp. 25 – 40. 79. Kawamoto T, Nakajima J, Reynard B, Toh H. 2015. Special issue ‘Geofluid processes in subduction zones and mantle dynamics’. Earth, Planets and Space 67: 46 – 53. 80. Kemp AIS, Hawkesworth CJ. 2004. Granitic Perspectives on the Generation and Secular ...
    ... of the Geochemical Processes Controlling the Distribution of Thorium in the Earth’s Crust and Australia’s Thorium Resources. Geoscience Australia Record 2008/05. 110. MIT OpenCourseWare. Trace-Element Geochemistry (pristupljeno 1.04.2014) http://ocw.mit.edu/courses/earth-atmospheric-and-pla ...

  • Towards a Mining Equipment Ontology

    Ranka Stanković, Ivan Obradović, Olivera Kitanović, Ljiljana Kolonja (2012)
    ... objects or entities) • Instances (individual entities) • Relations between entities • Properties of entities and their values • Functions and processes entities are involved in • Constraints and rules pertaining to entities Based on these elements an ontology offers a formal representation of knowledge ...

  • An aproach to Implementation of blended learning in a university setting

    Ivan Obradović, Ranka Stanković, Olivera Kitanović, Jelena Prodanović (2011)
    ... prevailing. Hence the term Web-based learning or Web- based education is now also frequently encountered. This concept encompasses all aspects and processes of education that use WWW as a communication medium as well as its supporting technology [1]. Within the interaction of ICT and education many ...

  • A Fuzzy Expert Model for Availability Evaluation

    Dejan Ivezić, Miloš Tanasijević, Predrag Jovančić, Radiša Đurić (2019)
    Each technical system within itself carries the great potential danger of possible occurrence of failure and damages. Mining machines are characteristic by great investment values, costs of unplanned shutdowns, complex working conditions, and environment and workers hazards. Systematic monitoring of the mining machinery is of great importance for the management of the mining companies. Availability is the overall concept of quality of service. Includes information regard to operating state, an idle state, a standby state and shut down. The ...
    raspoloživost, ekspertski sistem, fazi teorija, buldozeri
    ... Availability of bulldozers operating on surface lignite mines of Electric Power Industry of Serbia, which operate as auxiliary machines, is analyzed. Three different bulldozers (Liebherr - Lib, Dressta – Drs, Caterpillar - Cat), at three different surface mines (Drmno – D, Tamnava West Field – T ...
    ... reliable sources of information. The other approach is to use the experience of machine operators and workers in maintenance and logistics processes. The second approach is simpler and faster, and if it is verified by measured values it can be accepted as quite reliable. The implementation ...
    ... 572 0,84 III 2635 622 0,81 IV 2757 664 0,81 V 2008 343 0,85 V. CONCLUSION Bulldozers represent the most often utilized machinery on the surface mines. These machines are produced in large batches and it is very important to be selected in accordance with the working environment. Availability ...

  • Curcumin nanonization using an alternative small-scale production unit: selection of proper stabilizer applying basic physicochemical consideration and biological activity assessment of nanocrystals

    Ines Nikolić, Jelena Antić-Stanković, Dragana Božić, Danijela Ranđelović, Bojan Marković, Dominique Jasmin Lunter, Aleksandar Kremenović, Miroslav Savić, Snežana Savić (2020)
    As the number of poorly soluble drugs is increasing, nanocrystals have become very interesting due to wide range of application possibilities. Curcumin was used as a model active ingredient in this work. Even though it has many proven positive effects, due to its physicochemical issues, its possibilities have not been fully exploited. The goal of this work was to select optimal conditions for a top-down method for curcumin nanosuspension production, and to perform their comprehensive characterization applying complementary methodologies: ...
    nanocrystal, curcumin, top-down method, wetball milling