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Упит dcterms_subject_txt:grain size distribution

508 items

  • Mechanosynthesis and structural characterization of nanocrystalline Ce1–Y O2– (x=0.1–0.35) solid solutions

    Martin Fabián, Bratislav Antić, Vladimír Girman, Milica Vučinić-Vasić, Aleksandar Kremenović, Shigeru Suzuki, Horst Hahn, Vladimír Šepelák (2015)
    A series of nanostructuredfluorite-type Ce1–xYxO2–δ (0rxr0.35) solid solutions, prepared via highenergy milling of the CeO2/Y2O3mixtures, are investigated by XRD, HR-TEM, EDS and Raman spectroscopy. For thefirst time, complementary information on both the long-range and short-range structural features of mechanosynthesized Ce1–xYxO2–δ, obtained by Rietveld analysis of XRD data and Raman spectroscopy, is provided. The lattice parameters of the as-prepared solid solutions decrease with increasing yttrium content. Rietveld refinements of the XRD data reveal increase in microstrains in the host ceria ...
    Ceria, Yttrium, Solid solution, Mechanosynthesis, Oxygen vacancy, Nanocrystalline material

  • 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

  • A Knowledge-Based Approach to Mine Ventilation Planning in Yugoslav Mining Practice

    Nikola Lilić, Ivan Obradović, Ranka Stanković (2002)
    Ventilation system analysis is a complex process based on the calculation and analysis of numerous parameters. These problems can be successfully solved by the SimVent numerical package, but a full understanding and use of the obtained results require the involvement of an experienced specialist in the ventilation field. The solution was found in the creation of a hybrid system INVENTS, whose knowledge base represents a formalization of the expert knowledge in the mine ventilation field. In this paper, we ...
    ... the user interface of SimVent realized using Visual Basic and the Gene-Hunter dynamic library, giving a solution for the distribution and size of Table 2. The air distribution obtained by GA. Branch Inlet-Outlet R(Ns2/m8) Q(m3/s) p(Pa) NVP(Pa) pr(Pa) pbf(Pa) No. Node 1 1–2 0.41 34.93 500.85 187.2 ...
    ... ed Approach to Mine Ventilation Planning 377 of the location and size of booster fans in the “Soko” mine ventilation system, us- ing another AI method, the genetic algorithm (GA).6,12,13 A canonic scheme giving airflow distribution in the “Soko” mine is given in Fig. 14. The location of ex- ploitation ...
    ... important are the following: • determining air flow distribution throughout the ventilation network, • simulation of climate conditions in mine workings, • modeling of fire incidence in the ventilation network, as well as • gas distribution in the network. The results obtained through SimVent’s ...

  • Preliminary regional landslide susceptibility assessment using limited data

    Igor Peshevski, Milorad Jovanovski, Biljana Abolmasov, Jovan Papic, Uroš Đurić, Miloš Marjanović, Ubydul Haque, Natasha Nedelkovska (2019)
    In this paper a heuristic approach for preliminary regional landslide susceptibility assessment using limited amount of data is presented. It is called arbitrary polynomial method and takes into account 5 landslide conditioning parameters: lithology, slope inclination, average annual rainfall, land use and maximum expected seismic intensity. According to the method, in the first stage, a gradation is performed for each of the carefully selected conditioning parameters by assigning so called rating points to the grid cells on which the ...
    klizišta, podložnost
    ... relation to the change in size of the zones with high and very high susceptibility (in relation to the initial basic models TLSR100/500) and compare these with the change in number of landslides, then it can be seen that different models show changes from –1.83% to 1.68% for the size and –2.64% to 1.71% ...
    ... most significant change in size of the area un- der high and very high susceptibility, and the least change in number of landslides in these zones, both with negative trends. On the other hand, the models WAP-TLSR100 and WAP- TLSR500 show the most significant decrease in size of the area, but in this ...
    ... cor- relation with a positive trend of increase both in the size and num- ber of landslides. This leads to the conclusion that the model WSI-TLSR100 is the most suitable to be applied for this particular case study re- gion, since the size of the area under high and very high suscep- tibility has reduced ...

  • 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

  • SASA Dictionary as the Gold Standard for Good Dictionary Examples for Serbian

    Ranka Stanković, Branislava Šandrih, Rada Stijović, Cvetana Krstev, Duško Vitas, Aleksandra Marković (2019)
    У овом раду представљамо модел за избор добрих примера за речник српског језика и развој иницијалних компоненти модела. Метода која се користи заснива се на детаљној анализи различитих лексичких и синтактичких карактеристика у корпусу састављених од примера из пет дигитализованих свезака речника САНУ. Почетни скуп функција био је инспирисан сличним приступом и за друге језике. Дистрибуција карактеристика примера из овог корпуса упоређује се са карактеристиком дистрибуције узорака реченица ексцерпираних из корпуса који садрже различите текстове. Анализа је показала да ...
    Српски, добри примери из речника, аутоматизација израде речника, издвајање својстава, Машинско учење
    ... of eLex 2019 Figure 3: Boxplot of sentence (example) length (in number of characters) per partition. The distribution of punctuation marks (normalized on sentence size) is presented in Figure 4 on the left: dictionary examples have less punctuation marks than the control corpus. The average ...
    ... dictionary. The initial set of features was inspired by a similar approach for other languages. The feature distribution of examples from this corpus is compared with the feature distribution of sentence samples extracted from corpora comprising various texts. The analysis showed that there is a group ...
    ... traditional practice of dictionary example selection. Section 3 presents a part of the feature distribution analysis of examples from five SASA dictionary volumes, while a comparison with feature distribution in sentence samples extracted from corpora is given in Section 4. The research focused on the ...

  • Determining the Groundwater Balance and Radius of Influence Using Hydrodynamic Modeling: the Case Study of the Groundwater Source “Šumice” (Kikinda, Serbia)

    Dušan Polomčić, Dragoljub Bajić, Jelena Zarić (2015)
    A groundwater flow model was developed to simulate groundwater extraction from the public water supply source of the City of Kikinda. The hydrodynamic model includes the municipal groundwater source of Kikinda (Šumice and the Jezero Well), but also an extended area where there are groundwater sources that provide water supply to three factories: (MSK, TM and LŽT - Kikinda). Hydrodynamic modeling, based on the numerical method of finite differences will show the groundwater balance of the sources in the ...
    Water supply, Aquifer, Flow, Groundwater regime, Numerical modeling, Particle tracking
    ... the grain-size distribution of the water-bearing horizons, which also include the studied aquifer, the material of the water-bearing formation is represented by fine- and medium-grain sands (uniformity coefficient: Cu = d60/d10 = 2-3 mm with d50 = 0.1-0.3 mm, where d is particle/grain size: d10 ...
    ... sands, there are microgranular sediments: loamy sand, loessial clays, clays, and sandy clays. The transitions to fine-grain sediments are often gradual. Figure 2. Distribution of wells at the groundwater source of Šumice Journal of Sustainable Development of Energy, Water and Environment ...
    ... d10, d50 and d60 represents a grain diameter for which 10%, 50% and 60% of the sample will be finer than it or using another words, 10%, 50% and 60% of the sample by weight is smaller than diameter d10, d50 and d60). According to pumping test data, the transmissibility coefficient in the extended ...

  • Laboratory testing of fly ash

    Miloš Šešlija, Aleksandra Rosić, Nebojša Radović, Milinko Vasić, Mitar Đogo, Milovan Jotić (2016)
    Fly ash is one of the most common waste materials created by burning of coal. It is composed of smaller particles, consisting mainly of aluminosilicate glass, mullite and quartz, which are collected by electrostatic separators (filter) of gaseous products arising from the combustion of coal. This paper presents the pozzolanic properties, mechanical properties, chemical and mineral composition of fly ash obtained in the combustion process in a power plant Nikola Tesla A (PPNT A) with the addition of a ...
    chemical composition, fly ash, mechanical properties, mineral properties, pozzolanic properties, X-ray diffraction
    ... Positive after 15 days 10 3000 10000 15 4000 15000 The intensity of these processes depends largely on the ash fineness (particle size and particle size distribution), so that the pozzolanic reactivity increases with the specific surface of ash. International standard ASTM C 311 describes the procedures ...
    ... in mind that the tests are not carried out on samples of the ash that was previously fragmented, but the patterns of the original particle size distribution, the results are favorable. Compressive strength and tensile strength were tested for samples in S1 and S2, taken from the thermal PPNT A and ...
    ... fly ash has pozzolanic properties and is in Class 5 of pozzolanic materials. The tests were performed on samples of the original particle size distribution, which were not pre-shredded. 3.5 Mechanical properties of fly ash 3.5.1 Compressive strength – uniaxial strength After 7 days in a wet ...

  • Early–Middle Jurassic brachiopods from Ponor Mountain, Western Balkan Mountains, Bulgaria; taxonomy, biostratigraphy and occurrence in the context of the early Toarcian Oceanic Anoxic Event

    Barbara V. Radulović, Lubomir S. Metodiev, Neda Motchurova-Dekova, Platon Tchoumatchenco (2023)
    Brachiopods, taxonomy, biostratigraphy, early Toarcian Anoxic Event, Bulgaria

  • BaTiO3/NixZn1−xFe2O4 (x = 0, 0.5, 1) Composites Synthesized by Thermal Decomposition: Magnetic, Dielectric and Ferroelectric Properties

    Marija Šuljagić, Ivan Petronijević, Miljana M. Mirković, Aleksandar Kremenović, Adis Džunuzović, Vladimir B. Pavlović, Aleksandra Kalezić-Glišović, Ljubica Andjelković (2023)
    To investigate the influence of spinel structure and sintering temperature on the functional properties of BaTiO3/NixZn1−xFe2O4 (x = 0, 0.5, 1), NiFe2O4, ZnFe2O4, and Ni0.5Zn0.5Fe2O4 were in situ prepared by thermal decomposition onto BaTiO3 surface from acetylacetonate precursors. As-prepared powders were additionally sintered at 1150 °C and 1300 °C. X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM) coupled with electron dispersive spectroscopy (EDS) were used for the detailed examination of phase composition and morphology. The magnetic, dielectric, and ...
    ferroelectric, dielectric properties, magnetic properties, titanate/ferrite composites, phase composition
    ... (T), but several of them whose distribution can be presented with mean relaxation time (Tp = wpfl). This is characteristic of non-Debye relaxation in which the depression angle (0) relates to the distribution width of the relaxation time due to the non-uniform grain boundary structure of the samples ...
    ... FeaOu shell, and vice versa [68]. Mass magnetization values at room temperature for the sintered samples are listed in Table 2. Microstructure (grain size) and phase composition, as well as their interplay guuide the magnetization process and influence magnetic properties in general [69]. With an ...
    ... latter case and in comparison, to BaTiOyx /NiFe>»Ou and BaTiOa / ZnFe>»Ox, mass magnetization enhancement can be explained by the most significant grain size incre- ment as the sintering, temperature increased, Figure 4 and Table 2. The change in mass magnetization value in the temperature range from ...

  • Using Query Expansion for Cross-Lingual Mathematical Terminology Extraction

    Velislava Stoykova, Ranka Stanković (2018)

  • 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
    ... and corners become less sharp during the time. On the other hand, crystals induced by B. lentus cells have evident different particle size distribution since the size of the obtained forms varies the most for both samples during the incubation period. The morphology of CaCO3 Microorganisms 2021, 9 ...
    ... crystals during the incubation of B. simplex undergoes changes from the flower-like calcite to more rhombohedral shapes with constant particle size distribution. Similar spherical aggregates were observed for B. firmus during the MICP process. The regular rhombohedral morphology was observed for crystals ...
    ... pasteurii DSM 33; 2— B. muralis; 3—B. lentus; 4—B. simplex; 5—B. firmus; 6—B. licheniformis; black arrow—1st day; red arrow—14th day). The particle size distribution was narrow for referent strain S. pasteurii DSM 33 pre- cipitates, with sizes ranging from 3 to 5 µm, confirming the phase characterization above ...

  • 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
    ... ash and slag; • chemical analyzes of the ash and slag; • mineralogical tests of the ash and slag. The humidity samples, density of solid particles, grain size composition and pH value tests were done to determine the phy si- Figure 3. Location and coal �elds of the Kostolac basin (STOJANOVIĆ et al., ...
    ... slag. Sample humidity was examined according to the standard EN 1328-1, the solid particles volume weight test followed the standard EN 1097-7, grain size composi- tion was tested according to EN 933-1, EN 451-2 and SRPS U. B1.018., and the pH value test was done according to SRPS H. C8.209. All the ...
    ... Determination of fineness by wet sieving. EN 933-1 (1997): Tests for geometrical properties of aggregates – Part 1: Determination of particle size distribution – Sieving method. EN 1097-7 (1999): Tests for mechanical and physical properties of aggregates – Part 7: Determination of the particle density ...

  • 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
    ... feldspars and lithic fragments. Finer rocks are represented by siltstones or mudstones. Way up criteria (primarily the fining upward trend of grain size, relations of erosive/gradual transitions and the relationships of cross-lamination within beds) were used to recognize the (Fig. 1a, b). In terms ...
    ... lower part of unit B. Sedimentary structures of the finer-grained inter- Figure 3. A sedimentological column of the Kostadinovica succession. Grain size is shown on the right-hand side of the column (si – siltstones, f – fine- grained sandstone, m – medium-grained sandstone, c – coarse-grained sand- ...
    ... Croatica 73/3134 vals of this unit are obscured by cleavage, but wavy and rhythmic parallel lamination is recognized along with minute variations of grain size of the different lamina. Sandstone layers appear either as intervals of graded turbidite units or solitary structureless beds. Turbidite beds ...

  • 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 ...
    ... minimum value prescribed for Ev2. When creating a transition layer, the following 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% ...

  • 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

  • A hydrogeological model of the open-cast mine Tamnava - West Field (Kolubara Coal Basin, Serbia)

    Jelena Ratković, Dušan Polomčić, Dragoljub Bajić, Bojan Hajdin (2016)
    ... the northwest, where they join the sands of the lower aquifer. The grain-size distribution of the intermediate aquifer is relatively homogeneous in both vertical and horizontal directions, the sands are fine-grain and medium-grain, and the hydraulic conductivity is about 1x10-5 m/s. The intermediate ...
    ... strata. In the extended zone of the study area (Fig. 2), these deposits contain alluvial and terrace riverine-lacustrine sediments made up of medium- grain gravels and sandy gravels (river terraces and alluvial plains - riverbed sediments of the Kolubara, the Kladnica, the Turija and the Peštan). There ...
    ... The upper aquifer at Tamnava - West Field is largely comprised of alluvial and riverine/lacustrine terrace sediments - terrace gravels of various grain sizes in both A hydrogeological model of the open-cast mine… 47 vertical and horizontal directions. Well pumping tests have been conducted and ...

  • Assessments of effects of implementation of strategic plans for development of Belgrade District heating system

    Dejan Ivezić, Marija Živković, Aleksandar Madžarević, Miodrag Grujić (2020)
    The district heating system (DHS) is one of the key elements of the Belgrade energy system. Overview of the current state and basic characteristics of the DHS are presented in this paper. The focus is on the planned development of DHS and on the analyses of effects of realization of measures and projects defined by strategic documents related to DHS which are adopted by city authorities (Development Strategy of DHS and Strategy of Belgrade Development). Two exploratory scenarios were ...
    Daljinsko grejanje, LEAP, Primarni energetski faktor, Uvozna zavisnost, CO2 emisija

  • An arid phase in the Internal Dinarides during the early to middle Miocene: Inferences from Mg-clays in the Pranjani Basin (Serbia)

    N. Andrić-Tomašević, V. Simić, O. Mandic, D. Životić, M. Suárez, E. García-Romero (2020)
    Paleontology,Earth-Surface Processes,Ecology, Evolution, Behavior and Systematics,Oceanography

  • On the distribution modulo 1 of the sum of powers of a Salem number

    Dragan Stankov (2016)
    It is well known that the sequence of powers of a Salem number θ, modulo 1, is dense in the unit interval, but is not uniformly distributed. Generalizing a result of Dupain, we determine, explicitly, the repartition function of the sequence , where P is a polynomial with integer coefficients and θ is quartic. Also, we consider some examples to illustrate the method of determination.
    Algebraic integer, the house of algebraic integer, maximal modulus, reciprocal polynomial, primitive polynomial, Schinzel-Zassenhaus conjecture, Mahler measure, method of least squares, cyclotomic polynomials