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Упит dcterms_subject_txt:well-logging in karst

1998 items

  • Extensive vibrations of the belt conveyer drive electromotor of a bucket wheel excavator as a result of intesified wear-and-tear of its mount support

    Vesna Damnjanović, Predrag Jovančić, Snežana Aleksandrović (2017)

  • Synthesis and characterization of high-pressure and high-temperature sphene (CaTiSiO5)

    Jelena Pantić, Vladimir Urbanovich, Vesna Poharc-Logar, Bojan Jokić, Marija Stojmenović, Aleksandar Kremenović, Branko Matović (2014)
    Sphene (CaTiSiO5), a calcium titanosilicate ceramic has been prepared from a powder mixture of CaCO3, TiO2 and SiO2 using vibro-milling for homogenization and activation of precursors. During the highpressure and high-temperature synthesis (HPS) process at 4 GPa and 1,200 °C, sphene undergoes into phase transition, from room-temperature phase P21/a to high-temperature phase A2/a. Evidence of that structural phase transition is given in this paper using infrared, Raman spectroscopy and X-ray powder diffraction. Rietveld refinement was employed to get the ...
    Sphene, Phase transition, Raman spectroscopy, X-ray diffraction, SEM, IR

  • Approach to operational mine planning: Case study Tamnava West

    Dejan Stevanović, Mirjana Banković, Milica Pešić Georgiadis, Ranka Stanković (2014)
    ... wheel excavator (BWE) which is based on individually excavation of one cut. In this sense every mining block is divided in several cuts, and BWE excavation is conducted from top cut Figure 8. Technology of BWE is very well explained by many authors 8, 9. Figure 8. Mining block division ...
    ... 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 Approach to operational mine planning: Case study ...
    ... on which exploitation is carried out are often, small in size, with poor quality and with complex structure and geometry, often in locations that have unfavorable infrastructure, or in regions with significant political instability. In the vast majority, mining projects, that guarantee the ...

  • Hyperpycnites within the Devonian-Carboniferous flysch of the Carpatho-Balkanides (Kostadinovica, eastern Serbia)

    Miloš Radonjić (2020)
    This study presents new discoveries of vascular plants and the trace fossil Dictyodora liebeana (GEINITZ) from the Devonian–Carboniferous Kučaj-Zvonce flysch of the Carpatho-Balkanides and the implications of this fossil association for its sedimentary setting. The occurrence of the described plant debris in a deep-marine environment indicates the presence of hyperpycnites within the siliciclastic turbidites exposed at the Kostadinovica locality. The sedimentological data and the characteristics of the fossil material support the proposed model in which the sediment was at ...
    Mississippian flora, Dictyodora liebeana (GEINITZ), hyperpycnites, Kučaj-Zvonce flysch, Carpatho-Balkanides
    ... repeating thin bedded sandstones and silt- stones (Fig. 6a, c). Grading in the sandstone beds is normal or not visible while sorting of the grains is well to very well developed. Internal sedimentary structures are partially exposed in sand- stones and are represented by parallel lamination and wavy lami- ...
    ... 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 | 131–142 | 12 Figs. | www.geologia-croatica ...
    ... thin-sections (Fig.10g, h). (h) Thin-section showing the position of the traces in laminated siltstones viewed in non-polarized light. (h) Thin-section showing plant detritus in fine-grained sediment above D. liebeana viewed in non-polarized light. G eo lo g ia C ro a tica Radonjić Miloš: Hyperpycnites ...

  • Hydrothermal Synthesized and Alkaline Activated Carbons Prepared from Glucose and Fructose—Detailed Characterization and Testing in Heavy Metals and Methylene Blue Removal

    Sanja Krstić, Milan Kragović, Maja Pagnacco, Vladimir Dodevski, Branka Kaluđerović, Miloš Momčilović, Ivica Ristović, Marija Stojmenović (2018)
    glukoza, fruktoza, аktivni ugalj, hidrotermalni tretman, aktivacija hidroksida, teški metali, metilen plavo
    ... detailed characterization as well. In the presented paper, activated carbons were prepared by hydrothermal synthesis from easily accessible, eco-friendly and low-cost materials (glucose and fructose) and activated with different hydroxides in order to get the best properties for use in removal different (inorganic ...
    ... presence of amorphous carbon in all three AC@G–T–N2–t–XOH samples [49]. The XRPD diagrams presented in Figure 2b for AC@F–T–N2–t–XOH showed sharp and well-defined peaks, which indicate that besides amorphous, presence of a defined (crystal) structural arrangement occurs in all three fructose samples. ...
    ... According to the database in international center for diffraction data (ICDD), the peak positions indicate the presence of carbonates (X2CO3) (ICDD 01-074-6256) as well as oxides (X2O) (ICDD 01-072-1216) [50] (X is Li, Na or K) in form of crystal phases in all samples obtained from fructose. The most ...

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

    Dragana Đurić, Jelka Krušić, Biljana Abolmasov (2021)

  • Mineralogical study of clays from Dobrodo, Serbia, for use in ceramics

    Maja Milošević, Predrag Dabić, Sabina Kovač, Lazar Kaluđerović, Mihovil Logar (2019)
    keramika, glina, Dobrodo, mineralogija, sirovina, Srbija

  • Vebran Web Services for Corpus Query Expansion

    Ranka Stanković, Miloš Utvić (2020)
    U ovom radu se govori o razvoju veb usluga Vebran i njihovoj primeni u poboljšanju pretraživanja korpusa. Veb-servisi Vebran koriste se za konsultovanje spoljnih leksičkih izvora za srpski jezik (uglavnom elektronski morfološki rečnici i srpski Vordnet) i proširivanje korisničkih upita radi dobijanja relevantnijih rezultata iz srpskih korpusa.
    corpus search, web service, Serbian lexical resources, query expansion
    ... translation of the basic synsets in the PWN 3.0, the hypernym/hyponym relations in SWN mirror its hierarchical structure. Other relations are implemented more freely, depend- ing on specific lexicalizations in Serbian. These relations include antonymy, meronymy, as well as some cross-part of speech relations ...
    ... text belongs, as well as an indicator whether corpus text is written in Serbian or represents a translation from another language. The SrpKor2013 is not structurally annotated, although some or all lev- els of the text structure (section, title, paragraph, sentence) are annotated in some particular corpus ...
    ... Terminological resources Termi9 application supports the development of terminological dictionar- ies in various fields (mathematics, agronomy, mining), as well as the process- ing and presentation of terms in Serbian and English. Termi has been recently supplemented by the general Serbian-German bilingual ...

  • Projected changes in air temperature, precipitation and aridity in Serbia in the 21st century

    Boško Milovanović, Sebastian Schubert, Milan Radovanović, Vesna Ristić Vakanjac, Christoph Schneider (2021)
    In this study, the projected changes of the average monthly and annual air temperatures, precipitation amounts and De Martonne aridity index in Serbia in the 21st century are examined. For that purpose, the spatial distribution of air temperature and precipitation amount is statistically modelled using data of 64 climatologic stations and 421 precipitation stations for the period 1976–2005 using multiple linear regression. The De Martonne aridity index is calculated from the spatially distributed data. In order to obtain regional ...
    21 vek, temperatura vazduha, klimatske promene, De Martonne-ov indeks ardinosti, padavine, Srbija

  • Microstructural and magnetic properties of electrospun hematite/cuprospinel composites

    Mira Ristić, Aleksandar Kremenović, Michael Reissner, Željka Petrović, Svetozar Musić (2020)
    Phase composition, microstructural and magnetic properties of electrospun hematite/cuprospinel composites were investigated. Samples were synthesized starting with 0 to 10 mol% of copper relative to iron. The round shape of reference electrospun fbres was preserved upon their heating up to 600 °C in air, whereas at 700 °C hollow substructure was additionally formed. In these reference samples the presence of hematite phase was detected by XRPD. A small amount (traces) of Fe3O4 /γ-Fe2O3 was also found, due to the ...
    Electrical and Electronic Engineering, Condensed Matter Physics, Atomic and Molecular Physics and Optics, Electronic, Optical and Magnetic Materials

  • Environmental Energy Security Indicators as Tools for Environmental Protection

    Aleksandar Madžarević, Dejan Ivezić, Marija Živković , Miloš Tansijević (2019)
    Еколошка прихватљивост је постала незаменљив синтезни показатељ сваке валидне енергетске анализе у последње две-три деценије. Енергетска безбедност је у директној хармонији с еколошком прихватљивошћу кроз многе прописане политичке циљеве, економске користи, правне тековине итд. Индикатори еколошке сигурности представљају један од основних елемената за одређивање енергетске безбедности и снажне алате за усмеравање енергетског сектора ка одрживом развоју. У овом раду, анализа је била концентрисана на показатеље енергетске безбедности у области животне средине који се односе на сектор природног гаса у ...
    енергетска безбедност, еколошки енергетски индикатори, заштита животне средине, еколошка прихватљивост
    ... developing countries and, in energy terms, the demand for available energy is growing intensively [7]. In general, energy security is inextricably linked to the national security of a country and as such, can be considered in the context of general national state security as well as independently [8] ...
    ... 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 1 7th International Symposium MINING AND ...
    ... availability of energy resources are taken into account, as well as using them by type and intensity, economic growth, demographic indicators, political priorities and energy scenarios [2-4]. One of the key elements of energy policy in the Republic of Serbia, which has been actively promoted, is ...

  • Single and multi-phase inclusions in garnets from the Lešnica alluvion in the Internal Dinarides, Serbia

    Maja Milošević, Bojan Kostić (2021)
    ... 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 EGU21-2423 https://doi.org/10.5194/egusphere-egu21-2423 ...
    ... multi-phase inclusions in garnets from the Lešnica alluvion in the Internal Dinarides, Serbia Maja Milošević, Bojan Kostić Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Single and multi-phase inclusions in garnets from the Lešnica alluvion in the Internal Dinarides ...
    ... Attribution 4.0 License. Single and multi-phase inclusions in garnets from the Lešnicaalluvion in the Internal Dinarides, Serbia Maja Milošević and Bojan Kostić University of Belgrade, Faculty of Mining and Geology, Belgrade, Serbia Inclusions in garnets from the river Lešnica alluvion (Cer mountain area ...

  • 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
    ... model. The system structure and the main architectural components as well as their relation to the goal decomposition are described in Section 3. Implementation issues are discussed in Section 4, followed by a conclusion in the last section. 2. A FORMALIZATION OF VENTILATION STATE EVALUATION ...
    ... related to an object in the model /Fig. 1/. Thus both the procedural and declarative knowledge related to a class object could be represented. Such a modified OOA model was the used for the representation of the mine ventilation evaluation strategy as well as the other objects in the system and ...
    ... (event or effect) represented by the frame, as well as the relations of this frame to other frames in the system. The frame system is a hierarchical structure incorporating inheritance as an important property. Slots of a frame can obtain values in several different ways. Since the frame system ...

  • Comprehensive Profiling of Microbiologically Induced CaCO3 Precipitation by Ureolytic Bacillus Isolates from Alkaline Soils

    Olja Šovljanski, Lato Pezo, Jovana Stanojev, Branimir Bajac, Sabina Kovač, Elvira Tóth, Ivan Ristić, Ana Tomić, Aleksandra Ranitović, Dragoljub Cvetković, Siniša Markov (2021)
    MICP process, kinetic study, calcite, vaterite, MALDI-TOF identification, Bacillus licheniformis, Sporosarcina pasteurii
    ... were previously reported in scientific literature and described characteristics are in correlation with the obtained in this study. Briefly, B. muralis isolated from historical building material [31], as well as soil isolates B. muralis and B. licheniformis showed high potential in inducing precipitation ...
    ... growth in anaerobic conditions. The bacterial cultures were streaked onto TSA with an addition of 20% Urea and incubated for 5 days at 30 ◦C in the anaerobic jar. Sporulation rates for selected strains as well as reference cultures were examined at 30 ◦C on two different pH values (7.3 and 9.3) in TSB with ...
    ... induced CaCO3 precipitation (MICP) is a well-known bio-based solution with application in environmental, geotechnical, and civil engineering. The significance of the MICP has increased explorations of process efficiency and specificity via natural bacterial isolates. In this study, comprehensive profiling ...

  • Application of stochastic models for mine planning and coal quality control

    Dejan Stevanović, Božo Kolonja, Ranka Stanković, Dinko Knežević, Mirjana Banković (2014)
    ... 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 APPLICATION OF STOCHASTIC MODELS FOR MINE PLANNING ...
    ... mineralization and equipment performance is required in short range than medium range planning. Operational planning is concerned with daily or weekly requirements of the mine. Proper operational planning must conform to short term mine plans as well as satisfying many practical details that are unique ...
    ... s in out where is the number of layers05. , (5) By grouping exploitation mining blocks and forming a pile, the average grade of this pile is closer to the planned mean if compared to the grades of each individual block which com- prise the pile. This phenomenon of variance reduction is well known ...

  • 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
    ... power utility well service pulling unit Energies 2020, 13, x 10 of 15 4. Application of Conceptual Model for the Selection of an Artificial Lift Method at the Test Well GL oil well in Salman oil field in Iran has been chosen as a test well. The Salman oil field data are given in Table 4. Table ...
    ... Application of Conceptual Model for the Selection of an Artificial Lift Method at the Test Well GL oil well in Salman oil field in Iran has been chosen as a test well. The Salman oil field data are given in Table 4. Selection of mentioned method was done using an optimization model based on a mul ...
    ... of reservoir fluids, and well productivity characteristics. The importance of this work is reflected in the fact that for the first time the limits of the application of artificial lift methods as well as their advantages and disadvantages were defined in one place [6]. In 1988, E.P. Valentin and ...

  • 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
    ... n [2,9]. Most lignite is used in thermal power plants. In contrast to lignite consumption in thermal power plants, where lignite burns completely at high temperatures and where air pollution is controlled using electrostatic and bag-filtering dust precipitators, as well as flue gas desulphurization systems ...
    ... lignite and HDPE, shown in Figure 1a,b, as well as the fact that coal exists in a plastic state under such conditions [34]. The lignite/HDPE mass ratio was chosen based on our preliminary studies and literature data, which indicated that the maximum synergetic effect is observed in mixtures containing between ...
    ... compounds detected in lignite and its pyrolysates, differences in TICs of aromatic fractions of lignite and lignite/HDPE pyrolysates are evident (Figures S5 and S6; Table 8). This is reflected through the variations in contents of phenanthrene relative to its methylated derivatives, as well as the phenanthrene ...

  • Lower Berriasian ammonites from Dedina (Golubac Mountains, eastern Serbia) and their biostratigraphic implication

    Zdenek Vasícek , Dragoman Rabrenović, Petr Skupien, Barbara Radulović (2023)
    Ammonites, Taxonomy, Lower Berriasian, Getic, Northern Tethys, Serbia
    ... Remarks and relations. Ammonites carpathicus is a well-defined species. However, its systematic affiliation is highly disputed. The placement of the above species in the genus Strambergella has recently been discussed in detail by Frau et al. (2016a). In contrast to Frau et al. (2016a, p. 139), H ...
    ... and colleagues from Charles University in Prague, the Czech Academy of Sciences and the Geologic Survey in Brno. The studied collection (359 pieces) consists only of crushed, sometimes also laterally deformed, predominantly fragmentary ammonites, as well as external moulds and impressions. Only ...
    ... Substeueroceras is a well defined genus, endemic of the Andean Substeueroceras broyonense Hoedemaeker et al., 2016 basins. The independence from the other Andean genus Paro- Fig. 5B don_mceras Was discussed in Parent et AL. [201?' 2015), much more 1939 Neocomites beneckei (Jacob) in Roman and Mazenot; ...

  • Surface functional groups and degree of carbonization of selected chars from different processes and feedstock

    Marija Ilić, Franz-Hubert Haegel, Aleksandar Lolić, Zoran Nedić, Tomislav Tosti, Ivana Sredović Ignjatović, Andreas Linden, Nicolai D. Jablonowski, Heinrich Hartmann (2022)
    The knowledge ofthe structural and chemical properties of biochars is decisive for their application as technical products. For this reason, methods for the characterization of biochars that are generally applicable and allow quality control are highly desired. Several methods that have shown potential in other studies were used to investigate two activated carbons and seven biochars from different processes and feedstock. The chars were chosen to cover a wide range of chemical composition and structural properties as a hardness ...
    Biougalj, različiti procesi dobijanja, različite sirovine, površinski aktivne grupe, x-ray, FT-IR,XPS
    ... 9) and PW700g (7.9) is also in accordance with this finding. The pyrochars made at lower temperature release less ions corre- sponding to low ash content in SW500f as well as in BW550 and the dominant content of SIO> in the ash of HW500f. The leachate of ACI with high content of Al and Si has a ...
    ... the intensities in different wavenumber ranges, and it is therefore impossible to present the FT-IR spectra in a single plot. For this reason, they are compared according to the type of pyrolysis. The quality of the spectra is considerably reduced in comparison with spectra of well-defined molecular ...
    ... HCI. This absorption is due to C-O stretching vibrations in alcohols [85]. The bands of HW500fin this spectral region are less well resolved probably due to the presence of Si-O vibrations of quartz [88] that is present in this biochar in larger amount (see Fig 3 and Table 3). The bands at 859 ...

  • Contribution to the geotechnical classification of municipal waste landfills in Serbia

    Dragoslav Rakić, Irena Basarić, Laslo Čaki, Slobodan Ćorić (2018)
    Management, Monitoring, Policy and Law, Nature and Landscape Conservation, Geochemistry and Petrology, Waste Management and Disposal,Geotechnical Engineering and Engineering Geology,Water Science and Technology,Environmental Chemistry,Environmental Engineering