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Упит dcterms_subject_txt:fragmentation size

320 items

  • Filter rules for soil and geosynthetics

    Dragoslav Rakic, Irena Basaric Ikodinovic, Milenko Ljubojev (2021)
    Štetni efekti izazvani strujanjem vode kroz različite građevine (brane, nasipi i sl.) uspešno se rešavaju ugradnjom različitih filterskih slojeva. Osnovne funkcije filterskih slojeva su brza evakuacija vode uz sprečavanje unutrašnje erozije i iznošenje sitnih čestica tla. Ovi filterski slojevi najčešće se grade od krupnozrnih materijala (pesak, šljunak, kameni agregati), ali se pored prirodnih materijala sve više koriste i veštački geosintetički materijali. U radu su prikazana osnovna filtarska pravila koja treba ispoštovati da bi se izvelo uspešno projektovanje različitih filtracionih ...
    filter, baza, granulometrijski sastav, vodopropustljivosti, stabilnosti, začepljenje, izdržljivost

  • Geochemical evaluation of dolostone deposits in Montenegro: Implications for potential industrial applications

    Darko Bozovic, Vladimir Simic, Dragan Radulovic, Slobodan Radusinovic, Vesna Matovic, Anja Terzic (2024)
    This study presents a unique model for assessing the dependability of continuous parts of combined systems in open-pit mining through the application of fuzzy logic. Continuous sub-systems as part of the combined system of coal exploitation in surface mines have the basic function of ensuring safe operation, high capacity with high reliability, and low costs. These subsystems are usually part of the thermal power plant’s coal supply system and ensure stable fuel supply. The model integrates various independent partial ...
    примарне сировине, минералогија, физичко-механичка својства, технолошка својства, наука о материјалима

  • Adsorption and degradation of some psychiatric drugs by sol-gel synthesized titania-based photocatalysts: influence of tungsten and sodium content

    Nina L. Finčur, Maja J. Šćepanović, Mirjana Grujić-Brojčin, Biljana F. Abramović, Jugoslav B. Krstić, Aleksandar Kremenović, Tatjana Srećković, Aleksandar Golubović (2019)
    Mesoporous anatase nanopowders were doped with 0.05−0.5 mol% of W6, in order to obtain more efficient photocatalyst than TiO2 Degussa P25 in the degradation of amitriptyline (AMI) under simulated solar irradiation (SSI). Dominant XRPD peaks were ascribed to anatase phase, with additional peaks which could correspond to brookite, TiO2 bronze and sodium titanate, Na2Ti9O19. The Raman scattering measurements have confirmed anatase as dominant phase, with broad Raman feature at ~270 cm−1 possibly related to Ti–O–Na stretching vibration. All W-doped ...
    Sol-gel synthesis, Doped titania nanopowders, XRPD, Raman spectroscopy, Adsorption and photocatalytic degradation, Psychiatric drugs

  • Micro- to nanoscale textures of gold in arsenopyrite and scorodite from the As-Au-Bi assemblage of Drenjak locality (Serbia)

    Ivana Jelić, Janez Zavašnik, Marina Lazarov, Alena Zdravković, Sabina Kovač, Jovica Stojanović, Aleksandar Pačevski (2023)
    Arsenopyrite and pyrite are important carriers of Au that is present in the form of microscopic and “invisible” gold. Such gold can be expected to be released upon the process of oxidation of these sulfides. In studied gold mineralization at Drenjak, related to the granitoids of the Oligocene-Miocene Kopaonik Ore District, the main arsenopyrite-pyrite-(bismuthinite) sulfide assemblage was formed in the quartz bodies and partly replaced by scorodite (FeAsO4·2H2O) and Bi-arsenate. With only up to 5 ppm of gold recorded ...
    Economic Geology, Geochemistry and Petrology, Geology

  • 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

  • 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)
    ... of this mineral during transport. The rock fragments are rounded, sometimes jagged, up to 0.1 mm in size. There are also fragments of carbonate rocks, which do not differ from other grains in size and shape. The mentioned diversity indicates a wider area of erosion from different types of rocks ...
    ... Uniaxial compressive strength testing is a parameter that is determined experimentally. It depends on the structure of the rock mass, grain size and orientation, number and arrangement of cracks and fissures. For the same rock, strength may be different, depending on physical characteristics ...
    ... . Some have undulatory extincion due to the effect of pressure, which tells us that they are at least partly of metamorphic origin. The different size of this mineral, poorly sorted indicates a relatively short transport of the material. Crystal fragments are less presented, mostly small and ...

  • Димензионисање система завојних пумпи

    Марија Дивац (2024)
    Овај завршни рад се бави димензионисањем система завојних пумпи (Progressive Cavity Pumps - PCP) које се широко користе у нафтној и гасној индустрији, нарочито за подизање тешких и вискозних флуида. Завојне пумпе су се показале као ефикасно решење у бушотинама са сложеним условима,захваљујући својој способности да транспортују флуиде са високим садржајем чврстих честица и гаса.Рад обухвата анализу кључних параметара као што су вискозност, густина, дубина бушотине и притисак, који су пресудни за избор одговарајуће пумпе.Применом софтверског алата извршена је ...
    завојне пумпе, димензионисање, експлоатација нафте, вискозни флуиди, софтверска симулација, PCP пумпе
    ... A MMain Contactor Size: 38 A Delta Contactor Size: 38 A Star Contactor Size: 25 A Overioad Relay Size: 18 to25 Amps Required Cable Size: 3CxCopper 25 Samm Recommended Cable Size' 3CxCopper 25 Samm cCable Gland Size 25 MM Terminal Block Size: 63 A Cable Lug Size 25 samm Recommended ...
    ... d Crimping Tool: 16X25 MM Control Wiring Cable Size: 1.5 sSamm Power Wiring Cable Size' Copper 25 Samm 23 7. SAKUbYUAK V OBOM Ppajiy JeTaJbHO je aHajmnHpaH Hpomnec JHMcCH3HOHHCaHba CHcTeMa 3aBOJHHX HyMmu (Progressive Cavity Pumps - PCP) y Korrekcry Ha(THe H racHc HHJIyCTpHJe, Ca IIOCeCOHHM ...

  • State and perspective of individual household heating in Serbia: A survey-based study

    Boban Pavlović, Dejan Ivezić, Marija Živković (2021)
    This paper presents the results of the household survey on individual household heating systems in Serbia. The survey was conducted in the period October to December 2020 with the participation of 1100 households with individual household heating systems. The information collected in the questionnaire can be separated into three main parts: basic household data, current heating system characteristics, and households’ perceptions and attitudes. The survey results provide unique and comprehensive information concerning individual household heating systems and the main ...
    Domaćinstva, Individualni sistemi grejanja, Korišćenje energije, Stavovi potrošača, Anketa, Srbija

  • Characterization and Environmental Evaluation of Recycled Aggregates from Construction and Demolition Waste in Belgrade City Area (Serbia)

    Filip Abramović, Miroslav Popović, Vladimir Simić, Vesna Matović, Radmila Šerović (2024)
    General Materials Science

  • Overwiew of In-Pit Crushing & Conveying Technology in Open Pit Mines

    Ali Nasirinezhad, Dejan Stevanović, Dragan Ignjatović, Petar Marković (2021)
    The conditions under which contemporary surface mining operations is carried out obviously becoming increasingly complex. In such complex conditions, the optimization of haulage systems as the technological phase with the largest share in the total operating costs, is very important from the aspect of achieving profitability of the mining project. In a large number of cases, the application of traditional haulage systems with trucks (as the most dominant type of haulage in open pit mines) does not lead to ...
    In Pit Crushing and Conveying, IPCC, open pit mining, haulage, optimization, costs saving

  • 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

  • Opremanje bušotine X zavojnom pumpom

    Milan Filipović (2024)
    Ovaj rad se bavi osnovnim pojmovima i karakteristikama zavojnih pumpi.Prikazan je sklop zavojnih pumpi i njena prateća oprema. Objašnjen je princip rada zavojnih pumpi kao i uloga svakog mašinskog elementa koji se nalazi u pumpi. Razmotrene su prednosti i nedostaci primene ovih primarnih mehaničkih metoda eksploatacije ugljovodonika. Dat je uvid u inovativna rešenja problematike primene zavojnih pumpi. Na konkretnom primeru bušotine X su prikazani problemi kao i rešenja primene ovih primarnih mehaničkih metoda u praksi. Napravljena je detaljna analiza ...
    zavojne pumpe, oprema, primarne mehaničke metode, ugljovodonici, analiza rada
    ... 40 A Main Contactor Size: 38 A Delta Contactor Size: 38 A Star Contactor Size: 25 A Overload Relay Size: 18to 25 Amps Required Cable Size: 3CxCopper 25 Sqmm Recommended Cable Size: 3CxCopper 25 Sqmm Cable Gland Size 25 MM Terminal Block Size: 63 A Cable Lug Size: 25 Sqmm Recommended ...
    ... Recommended Crimping Tool: 16X25 MM Control Wiring Cable Size: 1.5 Sqmm Power Wiring Cable Size: Copper 25 Sqmm Slika 22 Karakteristike električnog-napojnog kabla Na osnovu rezultata proračuna prikazanom na slici 22, usvaja se kabl prečnika od 26mm. Sa prečnikom tubinga od 114.3mm ı pumpom ~76.2mm, ...

  • Frequency and Length of Syllables in Serbian

    Marija Radojičić, Biljana Lazić, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Ján Mačutek, Lívia Leššová (2019)
    Basic analyses of several properties of syllables (the rank-frequency distribution, the distribution of length, and the relation between length and frequency) in Serbian is presented. The syllabification algorithm used combines the maximum onset principle and the sonority hierarchy. Results indicate that syllables behave similarly to words as far as mathematical models are concerned, but values of parameters in models for syllables are quite different from those for words.
    frekvencije slogova, dužina slogova, srpski jezik
    ... words. The trend of the empirical repeat rate (𝑅𝑅 = (∑ 𝑓 )/𝑁 , with 𝐾 being the inventory size, 𝑁 the sample size, and 𝑓 , 𝑖 = 1,… , 𝐾 the frequencies) to decrease with the increasing inventory size is presented e.g. by Kelih (2013) for graphemes; it can be presumed that, in general, the less ...
    ... one of words. The trend of the empirical repeat rate (RR = (i, f,7)/N2, with K being the inventory size, N the sample size, and f;, i= 1,...,K the frequencies) to decrease with the increasing inventory size is presented e.g. by Kelih (2013) for graphemes; it can be presumed that, in general, the less different ...
    ... the discrepancy coefficient 𝐶 = 𝜒 /𝑁, where 𝜒 is the value of the test statistic from the Pearson 𝜒 goodness-of-fit test and 𝑁 is the sample size. As a rule of thumb, the fit is considered satisfactory if 𝐶 < 0.02 (Mačutek & Wimmer, 2013). Strauss et al. (2008, p. 11) formulated the hypothesis ...

  • Definisanje parametara čvrstoće na smicanje kod izvođenja kosina u ispucalom stenskom masivu

    Zoran M. Berisavljević (2016-04-01)
    Definisanje parametara čvrstoće na smicanje ispucalih stenskih masa predstavlja jedanod najzahtevnijih zadataka mehanike stena. Geotehnička istraživanja su uglavnomograničena na rezultate laboratorijskih ispitivanja malih makroskopski homogenihuzoraka, sa kojih se vrši ekstrapolacija rezultata na terensku razmeru. Ispitivanja semogu vršiti in situ, ali su i ona ograničena veličinom korišćene aparature imikrolokacijom na kojoj se vrše ispitivanja. Pored toga, moguće je vršiti različitaispitivanja na fizičkim modelima, koja su veoma složena i skupa. Ekstrapolacijapodataka sa malog uzorka na terensku razmeru daje mnogo bolje rezultate ...
    naponsko stanje, ispucalost, heterogenost, čvrstoća na smicanje, geološki indeksčvrstoće, Hoek-Brownov materijal, kompozitni uzorci, dezintegracija, povratna analiza

  • Quantitative analysis of syllable properties in Croatian, Serbian, Russian, and Ukrainian

    Biljana Rujević, Marija Kaplar, Sebastijan Kaplar, Ranka Stanković, Ivan Obradović, Jan Mačutek (2021)
    slogovi, distribucija rang-preciznost, slovenski jezici

  • Дефинисање геотехничких параметара еолских седимената земуснког платоа на основу лабораторијских и теренских SPT испитивања

    Ђорђе Крзман (2024)
    Циљ овог рада је био да се одреде геотехничке караткеристике предметног терена што представља полазну основу за рационално пројектовање и градњу. Истражним бушењем утврђено је да предметни терен изграђују четри лесна хоризонта и три слоја погребене земље до дубине од 22-23 m. Лабораторијским испитивањем добијени су ефективни параметри смичуће чврстоће, где се кохезија најчешће креће између c’=14 и 18 kPa, а угао унутрашњег трења f'= 25 - 30 °. Теренска SPT испитивањем уз коришћење прихваћених корелација у геотехничкој пракси ...
    лес, лабораторија, SPT, корелације, параметри
    ... interlayers of sand– |Detween 86-87m above sea level. Loess-like deposits have an uneven dusty composition, locally they |contain concretions 1-2 cm in size, tiny plant fibers and traces of Mn and Fe oxides. They have fine tubular porosity, appear compact, have a higher degree of humidity than upper sediments ...
    ... |BURIED SOIL - HORIZON III: les between elevation 80-81 (+ 1.5m). It has a silty clay composition, with |rare carbonate concretions up to 1 cm in size, carbonate scrams along cracks, Fe and Mn oxide staining. |Dark red to brown color, small tubular and fissured porosity, hard, crumbly, frinble. ...
    ... are of an uneven, silly, sandy composition, most often clayey, they contain carbonate in fhe form of mossy |accumulations and concretions 1-3 cm in size, as well as staining, stains and scraps of Mn and Fe oxides. | ney are easily destroyed to silt particles, they are wetted soft and soft plastic, ...

  • Control of substructure construction of railways in the Republic of Serbia

    Dragan Lukić, Dragoslav Rakić, Irena Basarić Ikodinović (2022)
    Контрола збијености природног тла (у ископу) или збијеног у насипу при изградњи саобраћајница представља један од основних облика контроле квалитета доњег строја. Код изградње брзих саобраћајница (аутопутеви и брза железница) приоритет је постизање високог нивоа контроле извршених радова. У циљу онемогућавања диференцијалног слегања (при изградњи насипа), или промене запремине услед допунског збијања материјала, које неминовно доводе до деформација, потребно је извршити оптимално збијање материјала. У оквиру овог рада приказује се техничка регулатива која регулише контролу збијености при изградњи железничке ...
    доњи строј, техничка регулатива, насип, збијеност, контрола
    ... provided that it does not contain more than 3% of grains up to 0.02 mm in size, which achieves safety against frost. The granulometric composition should meet the filter criteria in relation to the underlying layer. The maximum grain size is up to 60 mm, water permeability -4 m/s at the degree of compaction ...
    ... CONFERENCE ON CONTEMPORARY THEORY AND PRACTICE IN CONSTRUCTION XV the degree of compaction Rc* is applied here on the soil with a maximum grain size of 5 mm, and in relation to the maximum value of the unit weight in the dry state obtained by the experiment of laboratory compaction according to ...
    ... conditions for the quality of the material installed in the layers of the substructure in terms of the value of the degree of compaction Rc*, ie the size of the deformation modulus Ev2, are determined by the standard SRPS U.E1.010 and SRPS U.B1.047. When building new and improving and renovating existing ...

  • Correlation Between Dynamic CBR and Compaction and Bearing Capacity of Pavement Foundation Layers

    Milan Bogdanović, Snežana Bogdanović, Dragoslav Rakić, Irena Basarić Ikodinović (2024)
    This paper presents a dynamic California Bearing Ratio (CBRd) device that can be used on a prepared pavement foundation layer to obtain a certain parameter of the tested material in the laboratory and in situ in a direct and fast way. For the selected natural material (gravel), it is shown that the laboratory CBRd can be used to estimate the compaction and bearing capacity, because it correlates well with the parameters of the standard and modifed Proctor compaction tests. ...
    korelacija parametara, donji slojevi saobraćajnica, laboratorijska i terenska ispitivanja, dinamički kalifornijski indeks nosivosti CBRd
    ... ISO 14688-2:2018 did not indicate significant differences in the grain size distribution, and it was determined that the material is natural mineral soil, sandy gravel (Sa-Gr), and non-plastic, where one grain size or a grain size range (0.1-0.5 mm) predominates, while some intermediate grain sizes ...
    ... at a temporary landfill at 'Batajnica Inter- modal Terminal in Belgrade. The same material was used for laboratory and in-situ testing. The grain size distribution was determined on the basis of three representative samples in accordance with SRPS EN ISO 17892-4:2017. The identification-classification ...
    ... in the final layer of the substrate (subgrade). CBR;y is a complex measure of the strength of a material, and depends on factors such as the grain size distribution, shape, and roughness of the grain, water content, and compaction, and can be expressed in the range of 20% < CBR, < 150% [6]. A ...

  • Development of an integrated model for open-pit-mine discontinuous haulage system optimization

    Miodrag Čelebić, Dragoljub Bajić, Sanja Bajić, Mirjana Banković, Duško Torbica, Aleksej Milošević , Dejan Stevanović (2024)
    equipment selection, mine mechanization, expert judgment, linguistic variables, MCDM, FAHP

  • Cultural Heritage and Protection of Hand-Wheeled Pottery Manufacture in Western Serbia: Characteristics of Zlakusa Pottery Based on Sem-Eds and Optical Microscopy

    Milošević Maja, Zdravković Alena, Đordjević Biljana, Jelić Ivana (2021)
    ... Observed pores in sample 1 are of random orientation and size, indicating slower rotations of the potter’s wheel during the manufacturing process. Sample 2 has a specific fluid-structure that is consistent with the way it was fabricated. By the size and orientation of the pores, it is evident that ...