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Упит dcterms_subject_txt:well-logging in karst

1998 items

  • Simple 2D Gravity-density inversion for modeling of the sedimentary basin basement

    Ivana Vasiljević, Snežana Ignjatović, Dragana Đurić, (2019)

  • Some examples of interactions between certain rare earth elements and soil

    Zlatko Nikolovski, Jelena Isailović, Dejan Jeremić, Sabina Kovač, Ilija Brčeski (2021)
    Freundlich adsorption isotherm, sequential extraction, metallic ions, ICP-OES
    ... has been tested as well as the quantity in which these elements are bound to soil and later on extracted in solutions. The objective was to determine the soil capacity for disposal, first of all, of the electronic waste that contains these elements and to assume their fate in the environment. ...
    ... ns available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs ACCEPTED MANUSCRIPT This is an early electronic version of an as-received manuscript that has been accepted for publication in the Journal of ...
    ... of sand, clay and humus soil has been shown in Fig. 1. Fig. 1. X-ray diffractograms of powdered samples of sand, clay and humus type of soil Table IV shows the mineral phases of the samples and their presence in the tested samples as well as the phase designations used on the diffractograms ...

  • 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

  • Split-Desktop software for the analysis of fragment size distribution of blasted rock mass

    Milanka Negovanović, Lazar Kričak, Stefan Milanović, Jovan Marković, Nikola Simić, Snežana Ignjatović (2023)
    Drobljenje stena je najvažniji pokazatelj u proceni efekata miniranja pri proizvodnom miniranju u površinskoj eksploataciji. Stepen drobljenja stena ima veliki uticaj na efikasnost daljih operacija utovara, transporta, drobljenja i mlevenja. Optimalno drobljenje stena pri proizvodnom miniranju utiče na smanjenje ukupnih troškova proizvodnje. Stoga je pouzdana procena veličine drobljenja odminirane stenske mase veoma važno pitanje, ne samo u operacijama miniranja, već i u rudarskoj proizvodnji. Za predviđanje distribucije veličine komada odminirane stenske mase postoje različiti empirijski modeli. KUZ-RAM model omogućava ...
    Split-Desktop softver, drobljenje stena, miniranje, analiza, digitalna obrada fotografija

  • Tectono-lithostratigraphic model of the Northern Banat Miocene sediments (Pannonian Basin, Serbia)

    Dejan Radivojević, Ljupko Rundić (2017)
    ... Basin lies in southeastern Europe and extends over several countries. °e area of interest represents the most attention-grabbing part of Pannonian Basin in Serbia due to its hydrocarbon potential as well as for complex geology and presence of deepest depressions. °e hydrocarbon exploration in this area ...
    ... Basin lies in southeastern Europe and extends over several countries. The area of interest represents the most attention-grabbing part of Pannonian Basin in Serbia due to its hydrocarbon potential as well as for complex geology and presence of deepest depressions. The hydrocarbon exploration in this area ...
    ... dr.rgf.bg.ac.rs The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs 53 7th International Workshop | Neogene of Central ...

  • Cutting Resistance Laboratory Testing Methodology for Underwater Coal Mining

    Vladimir Čebašek, Veljko Rupar, Stevan Đenadić, Filip Miletić (2021)
    Geology,Geotechnical Engineering and Engineering Geology
    ... dr.rgf.bg.ac.rs The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs minerals Article Cutting Resistance Laboratory Testing ...
    ... soil tests. Up to date, there are no well-defined and accepted laboratory testing methods to determine the cutting resistance of a material to be excavated, even though several labora- tory methods are available to determine the cutting resistance of the material in the seams of surface mines. The Lübeck ...
    ... Resistance Testing Up to date, there are no well-defined and accepted testing methods to determine the cutting resistance of a material to be excavated. However, several laboratory methods are available to determine the cutting resistance of the material in the seams of surface mines. Nevertheless, the ...

  • Kinetics, mechanism, and equilibrium studies of the reactions between a ruthenium(II) complex and some nitrogen- and sulfur-donor nucleophiles

    Aleksandar M. Mijatović, Ratomir M. Jelić, Jovana Bogojeski, Živadin D. Bugarčić, Biljana Petrović (2013)
    Kinetika i mehanizam reakcija supstitucije između [Ru(trpi)(bpi)Cl]+ sa nukleofilima gvanozin-5′-monofosfatom, L-histidinom, tioureom i dimetilsulfoksidom proučavani su spektrofotometrijski u 0,1 M NaClO4 na 310 K. Red reaktivnosti za odabrane ligande je: tiourea > gvanozin-5′-monofosfat > L-histidin > DMSO. Ovaj red je povezan sa elektronskim, strukturnim i hemijskim karakteristikama kompleksa i nukleofila. Reakcija supstitucije sa tioureom je proučavana na tri različite temperature (288, 298 i 310 K). Negativna entropija aktivacije DS = potvrđuje asocijativni način aktivacije. Formiranje kompleksa [Ru(trpi)(bpi)H2O]2+ sa ligandima ...
    Kinetika, Ravnoteža, Ru(II), L-Histidin, Guanozin-5' -monofosfat, Dimetilsulfoksid, Tiourea
    ... for the selected systems are given in Table 2, while the distributions are shown in Figs. 6 and 7 (Sup- plementary Material, Figs. 3S and 4S). It is well known that 50-GMP can coordinate to metal ions via N1 and N7 positions, but binding through the N7 position in a neutral or weakly acidic medium ...
    ... that 50-GMP reacts very slowly. But, besides nitrogen donor atoms in the structure of the purine base and the well-known coordination to metal ions via N7 atoms, this nucleotide could be bound to Ru(II) via phosphate oxygen atoms as well. This kind of coordination has been already published for some ...
    ... dr.rgf.bg.ac.rs The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs ORIGINAL PAPER Kinetics, mechanism, and equilibrium ...

  • Age of the Jurassic hemipelagic sediments from the Ljubiš area (Zlatibor Mt., SW Serbia)

    Nikita Bragin, Nevenka Đerić (2020)
    Radiolaria, Dinarides, Jurassic, stratigraphy, Serbia
    ... dr.rgf.bg.ac.rs The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs 2020 | 73/3 | 143–151 | 6 Figs. | 1 Tab. | 2 Pls. ...
    ... species also in association with younger radiolarians in several samples indicat­ ing that this species may also be present in younger deposits – Callovian and even in the lower Oxfordian (GAWLICK, pers. comm.). Other taxa have broad stratigraphic ranges: Helveto- capsa matsuokai was found in the middle-late ...
    ... established for the first time. Radiolarite formations in this scheme are most com­ mon in the Middle and Upper Jurassic deposits. Biostratigraphic data of these numerous formations are variable. In some instances they are very comprehensive, while in the other cases they are scarce or rare. Some formations ...

  • Distribution of Uranium and Rare Elements in Radioactive Phosphate-Bearing Anomalies in Southeast Mongolia

    Boris Vakanjac, Neil Rutherford, Vesna Ristić Vakanjac, Tanita Đumić, Suzana Đorđević Milošević (2020)
    Soviet and Mongolian geologists initiated geological exploration of Mongolia for minerals after World War II (1945). These activities lasted until the breakup of the USSR in 1991. As part of this exploration systematic uranium and rare element exploration was undertaken across Mongolia. New exploration resumed in Mongolia at the beginning of the 21st century for a range of ore and mineral deposit styles including uranium, coal, base and precious metals and Fe-ore. This was generally undertaken by Western-based companies. This ...
    uran, radioaktivnost, kreda, retki elementi, fosfati, anomalije, Dornogobi

  • The State and Perspective of Belgrade District Heating System Development

    Dejan Ivezić, Marija Živković, Aleksandar Madžarević, Fethi Silajdžić, Samra Arnaut, Goran Đelić (2019)
    District heating (DH) system in Belgrade provides energy for heating of more than 21 million m2 in households (app. 50% of all households), public, commercial and industry sectors. Public Utility Company “Beogradske elektrane” is responsible for all segments of the DH system operation. The system is fueled mostly by natural gas. The share of renewables is negligible. The research analyzes effects of implementation of two main projects proposed in the Development Strategy of the PUC - the introduction of ...
    daljinsko grejanje, Beograd, razvoj
    ... Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs Dejan Ivezić is Professor in Energy and Sustainable Development at University of Belgrade – Faculty of Mining ...
    ... proposed in the Development Strategy of the PUC - the introduction of heat energy produced in Thermal power plant “Nikola Tesla A” (600 MW) and in CHP waste incineration plant in Vinča (56.5 MW). These projects are analyzed from energy and environmental aspects. Projections of fuel mix in Belgrade ...
    ... Mining and Geology, Head of the Center for Energy. He has more than 20 years of experience in research and involvement in Serbian energy planning and policy making. The State and Perspective of Belgrade District Heating System Development Dejan Ivezić (presenter)1, Marija Živković1, Aleksandar Madžarević1 ...

  • Alpine thermal events in the central Serbo-Macedonian Massif (southeastern Serbia)

    Milorad D. Antić, Alexandre Kounov, Branislav Trivić, Andreas Wetzel, Irena Peytcheva, Albrecht von Quadt (2015)
    General Earth and Planetary Sciences

  • Stratigraphy and microfossils (radiolarians and planktonic foraminifers) of the Upper Cretaceous (upper Santonian–lower Campanian) Struganik limestone (Western Serbia)

    Liubov G. Bragina, Nikita Yu. Bragin, Ludmila F. Kopayevich, Nevenka Đerić, Nataša Gerzina Spajić (2019)
    Paleontology, Stratigraphy, Ecology, Evolution, Behavior and Systematics

  • Multihazard Exposure Assessment on the Valjevo City Road Network

    Miloš Marjanović, Biljana Abolmasov, Svetozar Milenković, Uroš Đurić, Jelka Krušić, Mileva Samardžić Petrović (2019)
    Prirodni hazardi, izloženost, klizišta, poplave, bujice, GIS, R

  • Design of a sucker rod pumping system

    Ana Ponoćko (2024)
    For a long time in the history of oil production, sucker rod pumps have been the first and in many cases the only choice when it comes to mechanical extraction methods. Proper selection of each individual element of the system enables optimization, which entails benefits in the form of increased efficiency and reduced costs. The first part of the paper presents the underground and surface equipment of the rod pump and describes the operation of the entire system. The ...
    sucker rod pump, fluid production, mechanical extraction methods,, Prosper, QROD, RODSTAR
    ... R-rod T-tubing Example of a deep well pump designation according to API standards: 25 – 150– RHAM-12-5-2 21 3.2 Gas anchors Gas separators remove as much gas from the fluid in the well as possible before it enters the pump. The presence of free gas in the cylinder not only reduces the pump's ...
    ... Figure Well XX-1 in QRod 46 6.4 . Comparison of results from RODSTAR, PROSPER AND QROD Table 6.2. Output Well XX-1 Method Results RODSTAR PROSPER QROD m3/D 103 110 10.51 Peak pol.rod load (N} N 24158 25574 21211 _ Min.pol. rod load (N} N 13944 11260.3 16230 Nm 2797 5658 200 In this ...
    ... n of sucker rods in practice includes: [3]. 25 — 19.0 mm (3/4 in) x 15.9 mm (5/8 in) — 22.2 mm (7/8 in) x 19.0 mm (3/4 in) — 25.4 mm (l in) x 22.2 mm (7/8 in) — 22.2 mm (7/8 in) x 19.0 mm (3/4 in) x 15.9 mm (5/8 in) — 25.4 mm (1 in) x 22.2 mm (7/8 in) x 19.0 mm (3/4 in) [3] 3.4 Tubing ...

  • Geotechnical Conditions for Construction of Savski Trg Metro Station as a Part of the Belgrade Metro Line One

    Nemanja Stanic, Dragoslav Rakic, Josip Isek, Slavoljub Simic (2024)
    In order to solve serious traffic congestion in Belgrade, a number of studies regarding the Belgrade Metro construction have been carried out since 1973. However, only in 2019, the routes of the future metro lines 1 and 2 were de-fined as a part of the General Metro Construction Project. The lines are de-signed to intersect at the location of Sava Square, where an interchange met-ro station will be built. It represents a complex geotechnical structure consist-ing of three different ...
    metro station, geotechnical modelling, displacements

  • Fuzzy expert analysis of the severity of mining machinery failure

    Dejan V. Petrović, Miloš Tanasijević, Saša Stojadinović, Jelena Ivaz, Pavle Stojković (2020)
    Mining machinery failure is almost an everyday occurrence. Usually the failures bare certain consequences, which require additional financial costs to repair and restore the system to its operational state. The consequences are viewed through negative and damaging effects a failure has on the machine, health and safety of the employees, work environment, and on the environment. The removal of the consequences of the failure requires additional financial investment, which has a negative impact on the company’s business. In order ...
    Severity of failure, Severity of failure assessment, Mining machinery, Fuzzy sets, Fuzzy logic

  • Determining the Availability of Continuous Systems at Open Pits Applying Fuzzy Logic

    Miljan Gomilanović, Miloš Tanasijević, Saša Stepanović (2022)
    This work presents a model for determining the availability of continuous systems at open pits by applying fuzzy logic and fuzzy inference systems. The applied model was formed by the synthesis of independent partial indicators of availability. The model is based on an expert system for assessing the availability of continuous mining systems. The availability of the system, as a complex state parameter, is decomposed into the partial indicators, reliability, and convenience of maintenance, and the fuzzy compositions, used ...
    системи, континуални систем експоатације, површински коп, рударство, расположивост, фази логика, max–min композиција, min–max композиција

  • 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
    ... D, recorded data about uptime (t1) and downtime (t2) are available. These data for 5 years are presented in Table 2, as well as calculated values (as a quotient of uptime and total time in operations) of availability for three types of bulldozers - for each year and the average [9]. Obtained results ...
    ... dr.rgf.bg.ac.rs The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs 978-1-7281-0702-8/19/$31.00 ©2019 IEEE A Fuzzy Expert ...
    ... one overall (A). Identification of obtained results, for their easier interpretation, is presented at the end, as well as their comparative analysis. A. Proposition The first step in the making of expert model for A assessment is describing linguistic variables related to A itself and to R, M ...

  • Machine learning based landslide assessment of the Belgrade metropolitan area: Pixel resolution effects and a cross-scaling concept

    Uroš Đurić, Miloš Marjanović, Zoran Radić, Biljana Abolmasov (2019)
    Improvements of Machine Learning-based landslide prediction models can be made by optimizing scale, customizing training samples to provide sets with the best examples, feature selection, etc. Herein, a novel approach, named Cross-Scaling, is proposed that includes the mixing of training and testing set resolutions. Hypothetically, training on a coarser resolution dataset and testing the model on a finer resolution should help the algorithm to better generalize ambiguous examples of landslide classes and yield fewer over/underestimations in the model. This ...
    klizišta, podložnost, mašinsko učenje

  • Palaeoflora of Kamenica (Pranjani Basin, western Serbia)

    Zorica Lazarević, Ljubica Milovanović, Jelena Milivojević, Ivana Vasiljević (2019)
    Palaeofloras of the Paleogene in Serbia are relatively rare, especially in comparison with floras from Neogene sediments. Most Paleogene phytoas sociations from the territory of Serbia existed in a dry and warm climate. The youngest Paleogene phytoassociation originates from the Pranjani Basin (Western Serbia), locality Kamenica. The age of this palaeoflora is determined as Late Oligocene. This fossil plant assemblage is different from other Paleo gene phytoassociations.The palaeoflora from Kamenica is characterized with leaf imprints larger than in other ...
    макрофлора, млађи олигоцен, Прањански басен, Каменица
    ... oldest horizon is located in the western part of the basin (the village of Kamenica) and it consists of well cemented conglomerates and breccias lying directly over the peridotite-serpentine rock. above them is a sequence of alternating sandstones, con- glomerates and marlstones. Well preserved remains of ...
    ... dr.rgf.bg.ac.rs The Digital repository of The University of Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs 53 Palaeoflora of Kamenica (Pranjani Basin, western ...
    ... - mitic limestones and shales as well as one interca- lation of tuffits. The third horizon consists of marls and shales (ereMIja et al., 1977). The fossil fish Smerdis minutus (BLaINvILLe) (aN - đeLKOvIć, 1989) was found in the first horizon’s marls. This finding confirms the Oli gocene age of the sediments ...