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Упит dcterms_subject_txt:raw material

345 items

  • 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)
    ... Tunnel is being built by Chinese company CCCC, which is drilling and blasting material. Such material was delivered. The characterization of the rock material was performed. 2. EXPERIMENTAL RESEARCH 2.1. Material characterization, microscopic description Rock has a clastic, psammitic ...
    ... which results in a change in uniaxial compressive strength of rock after fire. Uniaxial compressive strength is an important parameter of rock material in the field of rock mechanics. It is the basic parameter for determining strength and classification of rock mass. It is determined experimentally ...
    ... rock is lower, it will have an impact on the tunnel structure, different measures will be required to ensure the excavation and a larger amount of material needed for construction of tunnel structure. Incidental actions in tunnels, such as fire, can also affect strength of surrounding rock. Due to ...

  • Sepiolite – a by-product of exploitation as a potential raw material in Serbian industry

    Radmila Gaćina, Katarina Urošević, Jelena Zakonović (2019)
    This paper gives a brief overview of the sepiolite deposits, the basic properties, and the possibilities of using this mineral. Particular attention is paid to sepiolites from domestic production, especially the use of sepiolites suitable for the development of small businesses and technologies, with a focus on environmental protection. Aim of this paper is to point out importance of this mineral and to draw attention to the use of domestic raw materials. With appropriate mechanical and chemical pretreatments, sepiolite is ...
    sepiolite, by-product, small-scale mine, marginal costs,

  • NMR kinetic studies of the interactions between [Ru(terpy)(bipy)(H2O)]2+ and some sulfur-donor ligands

    Aleksandar Mijatović, Biljana Šmit, Ana Rilak, Biljana Petrović, Dragan Čanović, Živadin D. Bugarčić (2012)
    Reakcije supstitucije monofunkcionalnog [Ru(terpi)(bipi)(H2O)]2+ kompleksa, gde je terpi = 2,2′:6′,2″-terpiridin i bipi = 2,2′-bipiridin, sa biološki relevantnim sumporo donorskim ligandima, kao što su tiourea, l-metionin, l-cistein i glutation, proučavane su u vodenim rastvorima tehnikom 1H i 13C NMR spektroskopije. Sve reakcije su proučavajne na pH 7,4, u prisustvu fosfatnog pufera, da bi se oponašalo fiziološko okruženje tokom procesa supstitucije. Reakcije se izvode na 295 K pod uslovima reakcija drugog reda. Uočeni rezultati pokazuju da brzina supstitucije snažno zavisi ...
    Materials Chemistry,Inorganic Chemistry,Physical and Theoretical Chemistry

  • 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

  • Callovian (Middle Jurassic) Sphriganaria (Brachiopoda) from the Jordan Valley (Middle East)

    Howard R. Feldman, Barbara V. Radulović, Fayez Ahmad (2023)
    Brachiopods, Middle Jurassic, Sphriganaria, shell microstructure, Ethiopian Province

  • 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
    ... chemical stabilization is used to improve the load-bearing capacity of the material. The foundation soil planum must meet the geometric requirements [3:6-6]: flatness of the soil material layer 30 mm/4 m; flatness of the stone material layer 50 mm/4 m; the maximum allowed deviation of the elevation of the ...
    ... construction of the embankment), or to change the volume due to additional compaction of the material, which inevitably leads to deformations, it is necessary to perform optimal compaction of the material. Within this paper, the technical regulations governing the control of compaction in the construction ...
    ... is used: capillary rise resistant material; unbound aggregate, grain size 0/125 mm; percentage of aggregate grains below 0.063 mm < 12%; percentage of aggregate grains below 0.02 mm < 5%; smaller contain more than 10% of fractions smaller than 0.02 mm. The material in the transition layer should meet ...

  • Mapping and classifying large deformation from digital imagery: application to analogue models of lithosphere deformation

    Taco Broerse, Nemanja Krstekanić, Cor Kasbergen, Ernst Willingshofer (2021)
    kontinentalna tektonika: kompresija, kontinentalna tektonika: ekstenzija, kontinentalna tektonika: transkurentni i transformni rasedi, pukotine, rasedi, zone snažnih deformacija, kinematika deformacija kore i omotača, teorijska mehanika, modelovanje
    ... these displacements to a Lagrangian (material-fixed) frame. Namely, we are primarily interested in the deformation of material, rather than the deformation at a location in space through which material advects. One can use the Eulerian displacements to follow material, provided that PIV-derived displacements ...
    ... relates the deformed state to the undeformed state. A material vector dX that runs from point P to Q (i.e. a side of a small material element) in the original configuration, to the material vector in the deformed configuration dx, with the material that first occupied points P and Q now in points p and ...
    ... at reverse faults, footwall material that was first at the surface will be buried by the hanging wall material and, therefore, no longer be at the surface. Subsequently, that material will no longer be visible with PIV, resulting in an accumulation of virtual material points at the fault trace. We ...

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

    Dejan Stevanović, Božo Kolonja, Ranka Stanković, Dinko Knežević, Mirjana Banković (2014)
    ... prediction of the performance of stock- piling systems for which reclaim slices include unequal amounts of material from the layers of material stacked, fig. 3. Quality of the reclaimed material is calcu- lated as the weighted average of pieces of the layers that are taken from the bed. In this calcu- ...
    ... prediction of the performance of stock- piling systems for which reclaim slices include unequal amounts of material from the layers of material stacked, fig. 3. Quality of the reclaimed material is calcu- lated as the weighted average of pieces of the layers that are taken from the bed. In this calcu- ...
    ... and added mass. The last variable can signifi- cantly reduce pile variability when a large material amount is homogenized, and variability among the lots decreases [4, 5]. The deposition sequence of the material also is able to affect grade predictability of each pile, requiring a more careful mining ...

  • Application of Lignite Combustion Waste Slag Generated in Heating Plants as a Partial Replacement for Cement. Part II: Physical–Mechanical and Physical–Chemical Characterization of Mortar and Concrete

    Milan Kragović, Nenad Ristić , Jelena Gulicovski, Andrijana Nedeljković, Snežana Pašalić, Ivica Ristović, Marija Stojmenović (2021)
    sagorevanje lignita, otpadna šljaka, zamena cementa, proizvodnja maltera i betona, fizičko-mehanička i fizičko-hemijska karakterizacija
    ... there is no planned waste disposal, in order to get a more realistic picture in terms of the quality of waste material, samples were taken by the square method from different places so that material of different ages was included. After sampling, the samples were mixed, homogenized and the required amount ...
    ... observed that with the increasing cement replacement by waste material, the strength of mortar specimens decreased at an early age (7 days). On the other hand, with increasing age (28 and 90 days) the strength of mortar with the waste material approached the values of the reference mortar. This is attributed ...
    ... mortars with a higher content of waste material is the lower quantity of free water necessary for the hydration of cement materials in the hardening period. Based on the results of concrete consistency testing, it can be concluded that as the content of waste material increased, the size of the slump decreased ...

  • The Importance of Geotechnical Investigations for the Construction of Transfer Station „Prelići“ on Landfill in Cacak – Serbia

    Dragoslav Rakić, Irena Basarić, Jovana Janković, Tina Đurić (2019)
    For the purpose of the facilities construction within the transfer station „Prelici“ in Cacak, specific geotechnical investigations were carried out based on which the technological project with the facilities schedule was developed. Significant deviations in relation to the presented results were determined during earthworks, so the additional geotechnical investigation works were carried out. Since the new investigation works have determined a different cross section of the terrain, it was proposed to move the planned facilities which led to the ...
    landfill, geotechnical investigations, transfer station
    ... municipal waste are multiple. From the point of view of achieving national goals, the level of recycling increases and obtains the necessary raw material for the work of the recycling industry. The mass and volume of the final disposed municipal waste are reduced, and therefore the operating costs ...
    ... into material of old municipal waste (MSW-kO), which was created by the former active waste disposal on the whole southern part of the site and into material made by remediation measures of this landfill area, i. e. its covering of inert material (MSW-prk). Both of these landfill material layers ...
    ... landfill, and ranges from 2.2 to 4.0 m (Figure 3). The inert earth material, which represents old waste cover (MSW-prk), is a clay-silty composition, black to dark brown, insufficiently compact and loose. It is mainly a construction material with rare fragments of brick and concrete, but gravel fragments ...

  • Cutting Resistance Laboratory Testing Methodology for Underwater Coal Mining

    Vladimir Čebašek, Veljko Rupar, Stevan Đenadić, Filip Miletić (2021)
    Geology,Geotechnical Engineering and Engineering Geology
    ... resistance of the excavator, values for rock material strength index proposed by Protodjakonow [1,14] were used. Rock material strength index, fpr, proposed by Protodjakonow is determined by the uniaxial compressive strength, σc (MPa), of the rock material, for which he gave the relationship: fpr = σc/10 ...
    ... ed 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 Works of Orenstein and Koppel developed a ...
    ... bucket knife or tooth in the laboratory on the drilling core samples or block-shaped rock material samples. Consequently, the testing method is most used for determination of the cutting resistance of the material to be excavated. 2. Coal Mining in Underwater Pit “Kovin” Exploration work in the coal ...

  • Geochemical study of U, Th and REE mineralizations in Jurassic sediments and hydrochemical characterization of groundwaters in Eastern Serbia – Case study: Plavna area

    Jovan Kovačević, Maja Todorović, Marina Ćuk, Petar Papić (2016)
    jurski sedimenti, uran, torijum, elementi retkih zemalja, podzemna voda, istočna Srbija

  • Natural two-dimensional pyrophyllite: Nanoscale lubricant, electrical insulator and easily-machinable material

    Borislav Vasić, Radoš Gajić, Ivana Milošević, Žarko Medić, Marina Blagojev, Marko Opačić, Aleksandar Kremenović, Dejan Lazić (2022)
    Pyrophyllite, with the chemical formula Al2Si4O10(OH)2, is a naturally occurring and abundant van der Waals mineral belonging to the group of phyllosilicates. It is very soft, layered crystal used for sculpting and an excellent electrical and thermal insulator aimed for the operation at high pressure and temperature. Here, for the first time, two-dimensional (2D) pyrophyllite obtained by both mechanical and liquid phase exfoliation is presented and investigated at the nanoscale. The layered structure provides low friction coefficient of around ...
    Atomic force microscopy, Insulating properties, Nanofriction and wear, Natural two dimensional materials, Phyllosilicates, Pyrophyllite

  • Damage quantification of built stone on Dark Gate (Belgrade, Serbia): sample of damage index application for decay rate evaluation

    Maja Franković, Nevenka Novaković, Vesna Matović (2015)
    The Dark Gate is the monument of culture, part of the cultural and historical complex of the Belgrade Fortress. It is constructed of limestone blocks that after 270 years of exposure to environmental conditions and different anthropogenic influences show wide ranges of decay forms. During 2007, detail registration of all built limestone microfacies and weathering forms was done using tools of monument mapping. A correlation scheme ‘‘intensity– damage category’’ was made according to the type, intensity, and distribution of ...
    Krečnjak, mapiranje, Indeks raspadanja, brzina raspadanja, progresija
    ... Degree-covering of surface Low Low High _ _ Mass of detaching stone material Medium · High _ Mass of detaching stone material High _ Thickness of the scales (mm) 10 Mass of detaching stone material Medium · High _ Number and dimensions of fissures – Small Low Low ...
    ... was not observed. As far as groups of weathering forms are concerned, most dominant are loss of stone material, deposits in the form of crusts and detachment (Fig. 4). Loss of stone material is generally presented as surface recession and relief, only occasionally as outburst. Black crusts and ...
    ... heavy damage are blocks with a significant loss of material that disrupts the original appearance of the stone element (Fig. 4b, d, f damage cate- gory 4 and 5 in Table 1). Moderate damage is manifested on stone blocks where loss of material is superficial (Fig. 4c, e damage category 3in Table ...

  • Production information system of the Pljevlja coal mine

    Božo Kolonja, Ranka Stanković, Filip Vuković (2018)

  • The impact of calculation of resources and reserves on mining activity in Serbia

    Jelena Zakonović, Katarina Urošević, Radmila Gaćina (2019)
    The appearance of interest of the world's most important mining companies i for investment in Serbia imposes the problem of harmonization of domestic legislation with foreign ones. In this paper, specific categorization and classification of mineral raw materials, which do not match in domestic and foreign practice, are treated. The existence of such a conflict of criteria in use for categorization and classification can lead to misunderstanding and create certain complications in business. The following sections outline some of ...
    geological exploration, deposits, solid mineral raw materials, mineral projects, mineral resources and reserves

  • Poboljšanje geotehničkih uslova izgradnje nasipa upotrebom geosintetika

    Anastasija Radovanović (2024)
    Za potrebe izrade rada na Master akademskim studijama ,,Rudarsko-geološkog fakulteta,,, studijskog programa Geotehnika, pod mentorstvom prof. dr Gordane Hadži-Niković , izvršena je detaljna analiza stabilnosti kosina nasipa na Vranjskoj petlji. Geotehnička istraţivanja i ispitivanja terena izveo je “Zavod za geotehniku iz Instituta za puteve a.d. Beograd”, a investitor je “Javno preduzeće, Putevi Srbije”.Metodološki pristup koji je korišćen za analizu stabilnosti kosina nasipa jeste kabinetsko istraživanje dostavljene dokumentacije i geostatički proračuni analize stabilnosti kosina nasipa, korišćenjem savremenih softverskih alata.Krajnji zaključak izvedenih istraţivanja je da ...
    tlo, nasip, analiza stabilnosti, faktor sigurnosti, geosintetici
    ... propisima za tlo sa uglom unutrašnjeg trenja o > 32, tako da preporučeni materijal zadovoljava minimalni faktor sigurnosti i mogao bi se ugraditi material lošijih fizičko-mehaničkih karakteristika. Rezultati su prikazani u Prilozima 7.17-7.24. Pored navedenih analiza i proračuna urađen je ı proračun ...
    ... 11 0 12 0 13 0 50 40 Safety Factor 0.000 0.500 1.000 1.500 2.000 2.500 3.000 3.500 i. Unit Weight 'Cohesion i 4.000 Material Name | Color (kN/m3) Strength Type (kN/m2) Phi | Water Surface | Hu Type | Ru 4.500 Nasip 18 Mohr-Coulomb 0 32 None o 5.000 al-prp 19 Mohr-Coulomb ...
    ... 1.500 2.000 2.500 3.000 3.500 4.000 4.500 5.000 5.500 6.000+ Prilog 7.2. Unit Weight (kN/m3) CCoohesion Color (kN/m2) Material Name Strength Type Phi | Water Surface Hu Type Nasip 18 Mohr-Coulomb 0 32 None o 19 Mohr-Coulomb 0 31 None 0 al-prp al-ps 19 Mohr-Coulomb 0 ...

  • Properties of fly ash and slag from the power plants

    Miloš Šešlija, Aleksandra Rosić, Nebojša Radović, Milinko Vasić, Mitar Đogo, Milovan Jotić (2016)
    This paper describes the physical, chemical and mineral properties of ash and slag, which were taken from thermal power plants Nikola Tesla A, Nikola Tesla B, Kostolac A and Kostolac B. The knowledge of the mineralogical material composition is important because the type of minerals directly determines the properties of the fly ash and slag and their possible application. Laboratory tests showed that ash and slag samples consist of the following minerals: amorphous materials, quartz, feldspar, mullite, melilite, cristobalite, ...
    fly ash, slag, physical composition, chemical composition, mineral composition, X-ray diffraction method
    ... The chemical properties of fly ash and slag are the most important indicator in the evaluation of their suitability as a building material. Know- ledge of the material mineralogical composition is significant be- cause the type of minerals directly determines the properties of fly ash and slag and ...
    ... in the environment. Slag is a mineral mixture that consists of ma- terial melted in the combustion process and other parts of non- combustible material. It falls through the latticed stokehole and is rapidly cooled and extinguished in water. The fly ash and slag landfills in Serbia occupy an area ...
    ... & ILIĆ, 2007). All the negative environmental indicators caused by fly ash and slag can be eliminated or reduced if they are used as build- ing material for road construction and other trafficked areas. The using of fly ash and slag as secondary materials for road construc- tions, saves huge amounts ...

  • 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

  • Manganese-pyromellitate complex as a precursor for preparation of spinel Mn3O4

    Lidija Radovanović, Željko Radovanović, Aleksandar Kremenović, Bojana Simović, Milica V. Vasić, Jelena Rogan (2022)
    In recent years, thermal decomposition studies of transition metal complexes with benzenepolycarboxylate ligands have become an area of a great importance due to the possibility of obtaining useful metal oxides with desirable electrical, magnetic and catalytic properties [1]. As a contrast to conventional methods for the preparation of metal oxides, such as hydrothermal or sol–gel treatment, thermolysis is faster, more efficient ...