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Упит dcterms_subject_txt:hydrographic characteristics

412 items

  • Novi pristup proučavanju tekstura minerala značajnih za istraživanje rudnih ležišta

    Aleksandar Pačevski (2022)
    ... aleksandar.pacevski(ergf.bg.ac.rs Key words: texture, ore, microanalysis, pyrite The complete determination of a mineral composition and textural characteristics of the ores is crucial for correct interpretation of the ore-forming processes and genesis of ore deposits in general. The study of ore textures ...
    ... more complete interpretation of the ore textures, very important microscopic examinations are necessary, Which enable further insight into all characteristics of ore on a micrometer scale, and thus provide significantly more data important for investigating not only deposit genesis, but also possibilities ...

  • Потреба за израдом биланса и оценом расположивих резерви подземних вода Републике Србије

    Зоран Стевановић, Вељко Мариновић, Бранислав Петровић (2021)
    Природне карактеристике Србије, просторна дистрибуција ресурса водe и њихових корисника, као и међусобна интеракција коришћења, заштите вода, као и заштите од вода, условиле су да се подземне воде на читавој територији морају посматрати интегрално, јединствено, комплексно и рационално. Међутим, тренутно је у Републици Србији могуће дефинисати само одлике појединих издани и/или изворишта услед непостојања довољних података за свеобухватну анализу стања ресурса. За оцену притиска на квантитет ресурса подземних вода, што је обавеза према Оквирној директиви о водама ЕУ (ОДВ) ...
    подземни водни ресурси, биланс, расположиве резерве, одрживо управљање, Република Србија

  • Heavy metals in lignite and soil of Kostolac-Kovin coal basin, eastern Serbia - comparative analysis with selected cities in Serbia, region, Europe and world

    Bogoljub Vučković, Bojan Dimitrijević (2023)
    The Kostolac-Kovin coal basin with an area of 320 km2, with 5 separate layers of coal and with a total of about 5.7 Bt of geological resources and reserves represents an exceptional potential for coal production in Serbia. The coal resources listed in this way are not fully exploitable, but they represent potential for consideration. In this paper, we deal with the geochemical characteristics of coal seams and perform a comparative analysis of coal affectation on the environment. With ...
    lignite, heavy metals, concentrations
    ... resources listed in this way are not fully exploitable, but they represent potential for consideration. In this paper, we deal with the geochemical characteristics of coal seams and perform a comparative analysis of coal af}ectation on the environment. P/ith 155 analyzes of HM from coal, 45 from ash, 165 ...
    ... as numerous others for geotechnical and hydrogeological purposes. In the last ten years, special attention has been paid to the ecological characteristics of lignite, and the contents of HM have also been determined. Apart from coal, samples were also taken from all sediments in the horizontal and ...

  • Application of machine learning for diagnosing the operation of a deep well pump in oil production

    Maja Trikić (2024)
    This paper will thoroughly examine how machine learning can improve the diagnosis of deep well pumps by analyzing the role and function of the pumps, dynamograms, sensor technologies, and diagnostic methods.Our analysis will provide insights into modern techniques and approaches for enhancing the performance and reliability of oil production systems, targeting cost reduction and increased operational efficiency.
    deep well pump, dynamograms, machine learning, diagnostics of operating coditions,Random Forest, XGBoost
    ... calculated based on measured boundary values for the smooth rod stroke and load, dimensions and characteristics of the downhole pump, the kinematic assembly of the horsehead, and the characteristics of the sucker rods.To develop a mathematical model for a smart transmission system for diagnosing ...
    ... length of the smooth rod, and total expansion. When all other parameters are known, such as the kinematic characteristics of the horsehead, dimensions of the 14 downhole pump, characteristics of the sucker rods, and fluid specifics, the characteristic points of the dynamogram are calculated and ...
    ... image processing, when it comes to shape description, there are two options: representing the shape from external characteristics, 1.e., its edges, or from its internal characteristics. Given that dynamometric cards are closed contours that can be treated as images or symbols, representing the shape ...

  • ‘Blue-’ and ‘Brown-speckled’ pottery from Qalhât, the Sultanate of Oman (13–16th centuries): Comparison with traditional Omani 19–20 century productions

    Liliana Gianni, Hélène Renel, Aleksandar Kremenović, Philippe Colomban (2020)
    Representative ‘Blue speckled’ (13–16th centuries) and ‘Brown speckled’ (13–21st century) wares recovered from the excavations in Qalhât or collected around Bahlâ city (Sultanate of Oman) were characterized by XRPD, SEM-EDS, Raman/optical microspectroscopy, and thermal expansion. Minerals present in the body (quartz, augite and albite as major phases, calcite, dolomite, rutile, anatase, phosphate, hematite and magnetite as minor phases) were identified by XRPD and/or Raman spectroscopy. SEM-EDXS microanalysis was performed on the glazes in order to compare their composition, especially ...
    Firing, Glaze, Traditional ceramics, Provenance studies, Augite

  • First paleomagnetic and magnetic anisotropy results from Montenegrо - the coastal area

    Emö Márton, Vesna Cvetkov, Martin Đaković, Vesna Lesić, Slobodan Radusinović (2021)
    ... lineations, perfectly following the Dinaridic trend recognized in Croatia. Onelocality, the only one with moderate tilt and rather poor statistical characteristics suggestpost–Eocene CCW, while those with steep dips have well-defined paleomagnetic directions, whichare aligned with the intermediate AMS direction ...

  • 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

  • Reconstruction of the Tethys’ Waning in the Balkans

    Dejan Prelević, Kristijan Sokol, Ana Mladenović, Violeta Gajić, Vladica Cvetković (2024)

  • 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
    ... by frames, which makes it a flexible and open concept for knowledge representation. In the same way object characteristics are represented by their attributes, frame characteristics are represented by their slots. Namely, the slot values describe the attributes of the object (event or effect) ...
    ... to generate an overall evaluation of the general ventilation state of the mine as well as suggestions for the improvement of particular characteristics of the ventilation system. Figure 11. The VENTEX interface The approach to the realization of the expert system is based on a symbolic ...

  • Uniaxial compressive strength test before and after standard fire test on rock mass

    Stefan Mitrović, Goran Todorović, Bojan Kostić, Milica Mirković-Marjanović, Nikola Božović, Marija Krstić, Aleksandar Erić, Radovan Gospavić, Snežana Ilić, Aleksandar Kijanović (2022)
    ... grain size and orientation, number and arrangement of cracks and fissures. For the same rock, strength may be different, depending on physical characteristics. Heat of environment can affect structure of rock mass, which results in a change in uniaxial compressive strength of rock after fire. ...
    ... SRPS EN 1363-1, with the intention to test uniaxial compressive strength after standard fire test. For the sandstone rock mass of determined characteristics, for which it is determined uniaxial compressive strength before standard fire test and obtained results are shown in this paper, it is not possible ...

  • Trans-Lithospheric Diapirism as a Possible Mechanism for Ophiolite Emplacement?

    Nikola Stanković, Taras Gerya, Vladica Cvetković, Vesna Cvetkov (2024)

  • Influence of mono- and two-component organic modifiers on determination of lipophilicity of tetradentate Schiff bases

    Nikola Stevanović, Aleksandar Mijatović, Aleksandar Lolić, Mario Zlatović, Rada Baošić (2021)
    Ispitivani su uticaji primene mono- i dvokomponentnih organskih modifikatora na određivanje lipofilnosti 12 tetradentatnih Šifovih baza metodom reverzno-fazne tankoslojne hromatografije. Osnovni cilj je da se proceni tip interakcije između posmatranih jedinjenja i komponenti primenjenih hromatografskih sistema i uspostavi neki obrazac ponašanja kako bi se lakše izabrala kombinacija organskih modifikatora koji će simulirati interakciju u biološkim sistemima na osnovu činjenica da iste osnovne intermolekularne interakcije su odgovorne za ponašanje supstanci i u biološkom i u hromatografskom sistemu. Primenjeni organski modifikator ...
    Šifove baze, Lipofilnost, RP-TLC, Organski modifikatori

  • 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
    ... dered construction of the “Bezdan 1” PS. Figure 2 shows the lowering of the water table of the analyzed alternatives. For each alternative, the characteristics of the groundwater control system: the number of wells and their spatial distribution, and the time need- ed to achieve maximal lowering of the ...
    ... was the shortest time. Instead, the time was related to the analyzed conditions and the eleva- tion of the water table for each alternative. • Characteristics of the groundwater control system (K2), which included the number of components of the groundwater control system, where the sys- tem was analyzed ...
    ... 44/1. As a result, Alternative 2 was proposed for the groundwater control system associated with the “Be- zdan 1” PS, whose general and spatial characteristics are: 12 wells with individual capacity of 40 l/s and seven days to lower the water table. In some cases, the FAHP analysis can eliminate certain ...

  • Permanent GNSS monitoring of landslide Umka

    Mileva Samardžić Petrović, Jovan Popović, Uroš Đurić, Biljana Abolmasov, Marko Pejić, Miloš Marjanović (2020)
    Клизиште Умка је једно од највећих насељених активних клизишта у Србији. Активност клизишта Умка се прати већ више од 85 година, различитим геотехничким и геодетским техникама. Од 2010. године, активност kлизишта се континуирано прати у реалном времену аутоматизованим перманентним системом за праћење базираним на Глобалним навигационим сателитским системима (ГНСС). Поред тога, од 2018. године активност клизишта се додатно прати кинематичким ГНСС одређивањем положаја скупа карактеристичних тачака као и применом UAV фотограметрије. Главни циљ овог рада је приказ резултата опажања три ...
    клизиште, перманентно праћење, ГНСС
    ... g, Institute of Transportation CIP, The Highway Institute and company Vekom. The detailed descriptions of the technical part and the main characteristics of the established automated GNSS monitoring system can be find in Erić et al. [6]. Generally, the Umka monitoring system consists of GNSS network ...
    ... the processing results is higher for the horizontal displacements (5 mm) than the vertical (11 mm) and is conditioned by GNSS positioning characteristics, ie the fact that GNSS positioning precision is more than two times lower in height than horizontal position. Considering the dynamics of the ...
    ... sanacija klizišta, Bled, 1981, Knjiga 1:119–134 (in Serbian). [15] S. Ćorić, D. Božinović, V. Vujanić, M. Jotić and B. Jelisavac, “Geotechnical characteristics of old landslides in Belgrade area”, In: K. Senneset, Ed. in Proc. of the 7th International symposium on landslides, 1996, Vol 2, Balkema, Rotterdam ...

  • Non-Detonating Chemical Mixture for Non-Invasive Methods of Rock Breaking

    Lazar Kričak, Milanka Negovanović, Nikola Simić, Stefan Milanović (2024)
    Within the Innovation developed several different non-detonating chemical mixtures for non-invasive methods of rock breaking. Laboratory and polygon tests gave the satisfactory results and knowledge enough to start the practical experiments in the field. The basis of this innovation is a theoretical assumption that certain chemical mixtures release a large quantity of gases during combustion. If these gases are found in the enclosed space a growing pressure on the walls of the chamber in which combustion takes place will ...
    non-detonating, chemical mixture, rock breaking, borehole pressure

  • Petrographical and organic geochemical study of the subbituminous coal from the Dubrava field, Aleksinac basin (Serbia)

    Željana Sekulić, Ksenija Stojanović, Achim Bechtel, Reinhard Sachsenhofer, Miomir Petrović, Ivan Kojić, Dragana Životić (2019)
    ... and deposition of MM associated with smaller input of bacterial and algal OM and higher contribution of angiosperm vegetation. Very similar characteristics are observed for samples in coal layer, located within the lower oil shale package, suggesting the cyclic repetition of environmental conditions ...

  • Substitution reactions of some novel sterically hindered monofunctional Pd(II) complexes

    Aleksandar Mijatović, Jovana Bogojeski, Biljana Petrović, Živadin D. Bugarčić (2011)
    Reakcije supstitucije monofunkcionalnih kompleksa [(TLtBu)PdCl]+ i [Pd(tpdm)Cl]+, gde je TLtBu = 2,6-bis[(1,3-di-terc-butilimidazolin-2-imino)metil]piridin i tpdm = terpiridindimetan, sa nukleofilima kao što su: tiourea, I−, Br−, NO2−, piridin i dimetil-sulfoksid (DMSO) proučavani su u 0,1 M vodenom rastvoru NaClO4 u prisustvu 10 mM NaCl. Reakcije su sprovedene na tri različite temperature (288, 298 i 308 K) korišćenjem tehnike zaustavljenog protoka na različitim temperaturama. Reakcije supstitucije su praćene pod uslovima pseudo prvog reda sa velikim viškom nukleofila. Dobijeni rezultati pokazuju da kompleks ...
    Materials Chemistry, Inorganic Chemistry, Physical and Theoretical Chemistry
    ... reactivity of used ligands is: thiourea > I� > Br� > NO2 � > pyridine > DMSO. This order is in agreementwith their electronic and structural characteristics. Thenegative values reported for the entropy of activation confirmed the associative substitu- tionmode. These results are discussed in order to ...
    ... ligands is: Mechanism thiourea > I~ > Br- > NO” > pyridine > DMSO. This order is in agreement with their electronic and structural Reactivity characteristics. The negative values reported for the entropy of activation confirmed the associative substitu- tion mode. These results are discussed in order ...
    ... significant influence on the decreasing of the substitution rate. Having in mind that these complexes are novel, for better understanding of their characteristics we compared the rate con- stants for the substitution reactions with I� with earlier published values for some other sterically crowded monofunctional ...

  • Pokazatelji recentne tektonske aktivnosti u speleološkim objektima Dževrinske grede (istočna Srbija)

    Ana Mladenović, Jelena Ćalić (2022)
    Sistem Timočkog raseda predstavljen je sistemom desnih transkurentnih raseda generalnog pružanja sever – jug, koji su bili aktivni u periodu oligocena i miocena u okviru Karpato-balkanskog orogena. Početak njihove aktivnosti vezuje se za rotaciju tektonskih jedinica Karpato-balkanida (Dacia Mega Unit) oko rigidne Mezijske jedinice. Aktivnost ovih transkurentnih raseda je akomodirala ovu rotaciju, pa se smatra da je kumulativno kretanje duž Timočkog raseda tokom perioda njegove aktivnosti bilo do 100 km. Usled kompleksnih tektonskih rotacija, rasedi ovog sistema doveli su ...
    Тимочки расед, Џеврински расед, Балта расед, спелеолошки објекат

  • Determination of Mechanical Properties of Altered Dacite by Laboratory Methods

    Veljko Rupar, Vladimir Čebašek, Vladimir Milisavljević, Dejan Stevanović, Nikola Živanović (2021)
    This paper presents a methodology for determining the uniaxial and triaxial compressive strength of heterogeneous material composed of dacite (D) and altered dacite (AD). A zone of gradual transition from altered dacite to dacite was observed in the rock mass. The mechanical properties of the rock material in that zone were determined by laboratory tests of composite samples that consisted of rock material discs. However, the functional dependence on the strength parameter alteration of the rock material (UCS, intact ...
    Geology, Geotechnical Engineering, Engineering Geology
    ... Knowledge of mineralogical-petrographic characteristics of rock material is essential when testing mechanical properties. The results of previous research show that the val- ues compressive strength of rock material is significantly influenced by microstructural characteristics, the most important of which are: ...
    ... Correlation of mineralogical and textural characteristics with engineering properties of selected granitic rocks from Turkey. Eng. Geol. 1999, 51, 303–317. [CrossRef] 13. Yılmaz, N.G.; Goktan, R.M.; Kibici, Y. Relations between some quantitative petrographic characteristics and mechanical strength properties ...
    ... that the mechanical properties of the rock Minerals 2021, 11, 813 4 of 19 material are affected mainly by the mineralogical and petrographic characteristics of quartz and biotite. Figure 2. Analyzed open pit slope consisting of dacite with microscopic images of the material: (a) altered dacite and ...

  • Knowledge and Rule-Based Diacritic Restoration in Serbian

    Cvetana Krstev, Ranka Stanković, Duško Vitas (2018)
    In this paper we present a procedure for the restoration of diacritics in Serbian texts written using the degraded Latin alphabet. The procedure relies on the comprehensive lexical resources for Serbian: the morphological electronic dictionaries, the Corpus of Contemporary Serbian and local grammars. Dictionaries are used to identify possible candidates for the restoration, while the dataobtainedfromSrpKorandlocalgrammarsassistsinmakingadecisionbetween several candidates in cases of ambiguity. The evaluation results reveal that,dependingonthetext,accuracyrangesfrom95.03%to99.36%,whilethe precision (average 98.93%) is always higher than the recall (average 94.94%).
    diacritic restoration, morphological dictionary, corpus, word n-grams, local grammars
    ... terminology related to social, national and religious conflicts, extremism and terrorism, information security. The Table 1 contains quantitative characteristics of the above-mentioned resources. Table 1: RuThes-like Thesauri Thesaurus Number of Number of Number of concepts Text Entries Conceptual Relations ...
    ... was semi-automatically generated from the published version of RuThes (RuThes-lite 2.0) (Loukachevitch et al., 2018). Table 2: Quantitative characteristics of synsets and entries in RuWordNet Part of Speech Number of Number of Number of Synsets Unique Entries Senses Nouns 29,296 68,695 77,153 Verbs ...
    ... synsets were linked to each other with the relation of part-of-speech synonymy (cross-categorial synonymy). The Table 2 contains quantitative characteristics of the RuWordNet synsets, senses, and unique entries. The hyponym-hypernym relations were established between synsets of the same part of speech ...