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Упит dcterms_subject_txt:metoda Null Space Monte Carlo

320 items

  • Синтеза и карактеризација керамике на бази сфена

    Jelena R. Pantić (2015-07-10)
    Механохемијска активација стехиометријске смеше реактаната TiO2, SiO2 и CaCO3 показала се као веома успешна и једноставна метода за добијање сфена (CaTiSiO5). На основу мерења релативних густина свих синтерованих узорака установљено је да максималну густину од 93,9 % имају узорци који су активирани 30 минута и синтеровани на 1200 °С. Микроструктурном анализом, тј. анализом слика синтерованих узорака активираних 30 минута, које су добијене скенирајућом електронском микроскопијом, опажа се бимодална расподела величине зрна, са просечном величином од 3 μm, односно 5 ...
    сфен, механохемија, Ритвелдова метода, оптичка спектроскопија, микроструктурна анализа, фазна трансфоpмација, чврсти раствори
    ... првенствено као метода за идентификацију фаза. Развој Ритвелдове методе (Rietveld 1967; Rietveld 1969), рачунарске технике и одговарајућих програма који користе ову методу (један од њих је и FullProf) омогућио је решавање и утачњавање структура поликристалних материјала. Ритвелдову методу користе још ...
    ... величине кристалита добијене Ритвелдовом методом, што показује да су зрна у ствари агломерати, састављени од неколико кристалита. Tакође, процес синтеровања под притиском доводи по смањења величине кристалита. Кључне речи: сфен, механохемија, Ритвелдова метода, оптичка спектроскопија, микроструктурна ...
    ... оксидација итд.) сигнал даје позитивне ΔТ вредности (Scott, 2000; Hemminger et Sarge, 1998). ДТА методом се прате фазни прелази, топлотни капацитет, температура и енталпија прелаза. Предности ДTA методе су што може да се користи на врло високим температурама, и што су инструменти врло осетљиви. ...

  • Geotechnical effects of municipal solid waste destruction with different compaction methods

    Jovana M Janković Pantić, Dragoslav R Rakić, Irena G Basarić Ikodinović, Tina D Đurić, Gordana Hadži-Niković (2022)
    Disposal of waste in municipal solid waste landfills is the only way of waste disposal in Serbia, with daily compaction and covering with soil material. Due to less space for the construction of new landfills, it is necessary to use their maximum capacity. Well-compacted municipal solid waste takes up less volume and enables safer storage, so it is useful to previously determine the compaction parameters in the laboratory: maximum dry unit weight (γdmax) and optimal water content (wopt). In ...
    komunalni otpad, zbijanje, Proktorov opit, malj sa šiljcima

  • Life Cycle Assessment of Individual Wood Biomass Heating Systems in Households

    Boban Pavlović, Dejan Ivezić, Marija Živković (2020)
    The use of solid fuels (wood biomass and coal) for heating of households continues to be common practice within European countries. Solid fuel combustion in households contributes more than 46% to total emissions of fine particulate matter. In this study, a life-cycle assessment (LCA) of firewood-based and pellet-based heating systems is performed. These two systems represent two different types of individual wood biomass heating systems. In the case of the firewood-based heating systems, it is analyzed a typical stove ...
    Grejanje, Analiza životnog ciklusa, Drvna biomasa, Individualni sistemi grejanja
    ... ISO 14000 and it deals with the comparative LCA of HSs throughout all stages of HSs’ lifetime. The exact data on the structure of energy use for space heating by the fuel and type of HS are not available in Serbia. For that reason, the inventory data of each phase of the LC process is collected through ...
    ... Households 431 3.1 Case study details For a detailed LCA study, it is obligatory to consider the operational period of HSs for a specific living space. The operating energy consumption of HSs is calculated by using data from the available Energy Agency of the Republic of Serbia’s (AERS) report on ...
    ... value) of each fuel. It is assumed that the period of use of the appliances is 20 years. Table 1 shows the estimated annual amount of fuels needed for space heating [18] in the case of firewood and wood pellet HSs for a typical flat [17]. The adopted efficiency data are based on [17] because manufacturers ...

  • An update on the mineral-like Sr-containing transition metal arsenates

    Tamara Đorđević, Ljiljana Karanović (2021)
    We report on the crystal structures of three novel synthetic SrM-arsenates (M = Ni and Fe3+), isostructural or structurally related to the minerals from tsumcorite, carminite and brackebuschite groups. They were synthesised under mild hydrothermal conditions and further characterised using single-crystal X-ray diffraction (SXRD), scanning electron microscopy with energy dispersive spectroscopy (SEMEDS) and Raman spectroscopy. SXRD and SEM-EDS yielded formulae: (I) SrNi2(AsO4)2·2H2O, (II) Sr1.4Fe3+ 1.6(AsO4)2(OH)1.6 and (III) SrFe3+(AsO4)(AsO3OH). All three structures are built up of slightly distorted MO6 octahedra ...
    арсенати метала, кристална структура, дифракција рендгенских зрака на монокристалима, хидротермална синтеза, Раманова спектроскопија, релевантна једињења у животној средини, арсенeochemistry and Petrology

  • Crystallography and Surface Oxidation of Stoichiometric Arsenopyrite from Šumadija-Kopaonik Pb-Zn/Polymetallic Ore District (Serbia)

    Ivana Jelić, Aleksandar Pačevski, Aleksandar Kremenović, Aleš Šoster, Andreja Šestan, Janez Zavašnik (2023)
    The behaviour and stability of arsenopyrite largely depend on its crystal structure, but studies of crystallography and structural defects are scarce. For clarification, we investigated a series of natural arsenopyrite crystals from the polymetallic Pb-Zn-(±Cu,Ag,Au,Sb,Bi,W) Šumadija-Kopaonik ore district (Serbia) by powder X-ray diffraction (XRPD). Among them, samples from the Drenjak gold mineralisation showed near-stoichiometric FeAsS composition and were further investigated by conventional and high-resolution transmission electron microscopy methods. TEM revealed abundant planar crystallographic defects and epitaxial surface oxide layer ...
    Inorganic Chemistry, Condensed Matter Physics,General Materials Science, General Chemical Engineering, crystal structure, FeAsS, oxidation, TEM, XRPD
    ... arsenopyrite is closely related to the orthorhombic marcasite [10] and tetragonal rutile [9]. Our observations confirm a monoclinic crystal system, space group P2; /c [9]. As observed on the experimental Kikuchi lines image (Figure 4b,c), the whole pattern symmetry is m (Figure 4a,b), and the arsenopyrite ...
    ... the TEM analysis closely resembles the marcasite prototype structure (Figure 4d). We interpret the occurrence of the forbidden hk0 reflections (space-group absences) observed in the experimental SAED (Figure 4a) to occur due to twinning [10]. Figure 4. (a) SAED pattern indexed for arsenopyrite ...
    ... , with the corresponding, (b) CBED pattern showing Kikuchi lines. (c) Simulated SAED and CBED (threshold 55%, intensity factor 1%, squares are space group absences). (d) Arsenopyrite crystal structure in the same orientation left to right: ball-stick model, coordination tetrahedra model, Fe-tetrahedra ...

  • Understanding the effect of synthesis and sintering temperature on the functional properties of barium titanate/cobalt ferrite composites

    Marija Šuljagić, Aleksandar Kremenović, Ivan Petronijević, Adis Džunuzović, Miljana Mirković, Vladimir Pavlović, Ljubica Anđelković (2023)
    To investigate the effect of synthesis procedure and sintering temperature on the functional properties of perovskite/spinel ceramics, BaTiO3/CoFe2O4 composites were prepared by thermal decomposition, coprecipitation, and microemulsion method, and sintered at 1150°C and 1300°C. The phase composition and morphology of as-prepared powders as well as sintered ceramics were thoroughly examined by X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM) coupled with electron dispersive spectroscopy (EDS). The dielectric and ferroelectric measurements were performed in detail. Generally, the ...
    Perovskite/spinel ceramics, Multiferroic, Sintering, Influence of synthesis method

  • Depth geological relations of the wider area of Belgrade - based on the wells and geophysical data

    Đorđe Marinović, Ljupko Rundić (2020)
    Предметна референца обухвата простор шире околине Београда укупне површине око 2.000 km2. Аутори су објединили капиталне геолошке и геофизичке податке обезбеђене површинским истраживањима и мултидисциплинарним елементима из 52 бушотинe са дубинама између 33 и 2.733 m. Конкретни палеонтолошки налази специјализованих аналитичара са детерминацијом макро и микрофауне и флоре, презентовани су како из неогених формација тако и из басенске подине. Осим конвенционалних петролошких описа стена цитиране су и микроскопске детерминације интрузивних и екструзивних магматита. Из затвореног басенског простора корелативно су ...
    неоген, дубинска разграничења, геофизички показатељи, структурно-палеогеографска интерпретација

  • Classifying large strains from digital imagery: application to analogue models of lithosphere deformation

    Taco Broerse, Nemanja Krstekanić, Cor Kasbergen, Ernst Willingshofer (2021)
    ... describesdisplacement in a spatial reference, and material moves through the area in view, displacementsat any given time refer to fixed locations in space, and not to specific material points. Byreconstructing the path of material, we can follow small regions of material while they translate,rotate and ...

  • Water in the Alluaudite Type-Compounds: Synthesis, Crystal Structure and Magnetic Properties of Co3(AsO4)0.5+x(HAsO4)2−x(H2AsO4)0.5+x[(H,□)0.5(H2O,H3O)0.5]2x+

    Tamara Đorđević, Ljiljana Karanović, Marko Jagodič, Zvonko Jagličić (2021)
    In this study, a new cobalt arsenate belonging to the alluaudite supergroup compounds with the general formula of Co3(AsO4)0.5+x(HAsO4)2−x(H2AsO4)0.5+x[(H, )0.5(H2O,H3O)0.5]2x+ (denoted as CoAsAllu) was synthesized under hydrothermal conditions. Its crystal structure was determined by a room-temperature single-crystal X-ray diffraction analysis: space group C2/c, a = 11.6978(8), b = 12.5713(7), c = 6.7705(5) Å, b = 113.255(5)◦, V = 914.76(11) Å3, Z = 2 for As6H8Co6O25. It represents a new member of alluaudite-like protonated arsenates and the first alluaudite-like phase ...
    супергрупа алуаудита, арсенати прелазних метала, хидротермална синтеза, кристална структура, хидратисани хидрокси-арсенати, стехиометрија, магнетна својства

  • Determining the Impact of Cutting Elements State on the Bucket–Wheel Excavator Vibration and Energy Consumption

    Filip Miletić, Predrag Jovančić, Miloš Milovančević, Miloš Tanasijević, Stevan Đenadić (2022)
    Background There are two types of specifc sizes’ measurements. The frst is the measurement of energy consumption in a working technological process, and the second is the measurement of vibration, which is displayed over amplitudes of speed. There is an interplay between these two processes. Increasing the power consumption, the value of the vibration speed amplitudes increases. Purpose The process of the determination of machining parameters was based on minimizing the power consumption and vibration of the cutting tool, ...
    merenje, potrošnja energije, vibracije, radni vek reznog elementa

  • Conversion of land areas after coal mine closure and reclamation

    Radmila Gaćina, Bojan Dimitrijević, Sanja Bajić (2023)
    Otkopavanje uglja površinski i podzemno praćeno je degradacijom zemljišta, promenom formiranja predela i izmenom flore i faune. Od velikog značaja je razvoj novih naučno utemeljenih pristupa obnovljanje antropogeno poremećenih predela zasnovanih na formiranju rekultivacionih i rudarskih tehnologija. Apsolutno je neophodno obezbediti sveobuhvatno kvalitetno očuvanje zemljišnih i vodnih resursa i odrediti rekultivisano zemljište za novu namenu. U ovom članku je dat pregled najpopularnijih metoda rekultivacije zemljišta i mogućnosti rekultivacije zemljišta nakon završetka rekultivacije i zatvaranja rudnika uglja.
    rekultivacija, melioracija, revitalizacija, otkopavanje uglja, održivi razvoj
    ... considering the topographical changes of the green space that would directly affect the degradation of agricultural lands. Predictions of the effects on the environment are very important and present the concern in the sense of the loss of surface area and space for living. The study on the environment has ...
    ... same time further harmonizing it with the relevant EU legislation [10]. Basic decisions on the national level are sometimes contradictory and leave space for discussion about the energy strategy in Europe. On the one side, the coal phasc-out gathers pace. Most EU countries have announced the national ...

  • A comparison between ARIMA, LSTM, ARIMA-LSTM and SSA for cross-border rail freight traffic forecasting: the case of Alpine-Western Balkan Rail Freight Corridor

    Miloš Milenković, Miloš Gligorić, Nebojša Bojović, Zoran Gligorić (2023)
    železnica, prekogranični teretni saobraćaj, ARIMA, LSTM, SSA

  • Strategic Environmental Assessment in the Application of Preventive Protection for Wind Farm Noise—Case Study: Maestrale Ring Wind Farm

    Boško D. Josimović, Aleksandar Cvjetić, Božidar Manić (2021)
    Determining the spatial position of wind turbines is the initial and most important phase in the development of a wind farm project. In this sensitive phase, all potential problems that may arise in the later stages of project development should be prevented by means of spatial and urban planning instruments. This makes it possible to achieve maximum use of the potential of wind in a particular space and, thus, fulfil the technical and economic requirements of the project while ...
    Energija,energetski inženjering i elektroenergetska tehnologija,obnovljivi izvori energije, održivost i životna sredina,električni i elektronski inženjering,kontrola i optimizacija,inženjering
    ... while respecting the capac- ity of the space and involving the public in all phases of developing and adopting the SEA. In this context, SEA makes a significant contribution to the decision-making process with regard to the future development of a particular space [15] and it is an important instru- ...
    ... prevented by means of spatial and urban planning instruments. This makes it possible to achieve maximum use of the potential of wind in a particular space and, thus, fulfil the technical and economic requirements of the project while re- specting the goals of environmental protection in that same area ...
    ... Plan of the Maestrale Ring wind farm). Criteria Rank Description Magnitude of Impact Significant −3 Significantly burdens the capacity of the space (increase in noise levels at recep- tors over 4 dB compared to Limit values for the noise indicators (LVNI) Greater −2 Disturbs the environment ...

  • Machine learning based landslide assessment of the Belgrade metropolitan area: Pixel resolution effects and a cross-scaling concept

    Uroš Đurić, Miloš Marjanović, Zoran Radić, Biljana Abolmasov (2019)
    Improvements of Machine Learning-based landslide prediction models can be made by optimizing scale, customizing training samples to provide sets with the best examples, feature selection, etc. Herein, a novel approach, named Cross-Scaling, is proposed that includes the mixing of training and testing set resolutions. Hypothetically, training on a coarser resolution dataset and testing the model on a finer resolution should help the algorithm to better generalize ambiguous examples of landslide classes and yield fewer over/underestimations in the model. This ...
    klizišta, podložnost, mašinsko učenje

  • Improvement of geodatabase queries within GeolISS

    Ranka Stanković (2008)
    ... can be part of a relational table as a normal column and processes using a multitude of operators. The space required for storage and sharing of vector data is usually much smaller than the space required for raster data. Another advantage of vector data is that they can be easily updated and maintained ...
    ... vector data model to represent reality. Raster data sets record a value for each point in the area of interest, which may require more storage space than the representation in vector format that stores only the Ranka Stanković 66 necessary data. Vector data can be displayed as vector graphics ...

  • 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
    ... secondary technical limitations, such as temperature limitations, operator training, availability of the main source of energy, fluid, surface conditions (space limitations, noise, visibility, safety), and additional limitations at the bottom of the well (high gas-liquid ratio—GLR, scale, sand, corrosion) ...

  • Kristalne strukture Cs2HoSi4O10F i Cs2TmSi4O10F

    Predrag Dabić, Sabina Kovač, Aleksandar Kremenović (2021)
    ... were determined by single-crystal X-ray diffraction analysis. They represent mutually isostructural compounds which crystallize in the orthorhombic space group Pnma with following unit cell parameters: a = 22.3809 (7), b = 8.8686 (3), c = 11.9827 (4) V = 2378.41 (14) 3, Z = 8 (for Cs2HoSi4O10F compound) ...
    ... dobijena su dva jedinjenja do tada nepoznatog hemijskog sastava - Cs2HoSi4O10F i Cs2TmSi4O10F, u obliku monokristala. Jedinjenja su sintetisana metodom rasta kristala iz visokotemperaturnog rastvora (Tmax = 1373 K) koriste i REE2O3 (REE = Ho, Tm), SiO2 i CsF kao polazne suptance. Kristalne strukture ...

  • Određivanje zbijenosti starog komunalnog otpada

    Jovana Janković, Dragoslav Rakić, Irena Basarić Ikodinović, Tina Đurić (2021)
    Bez obzira na savremene tretmane komunalnog otpada u svetu, u Srbiji je i dalje najčešći vid odlaganja na komunalne deponije, pa zbijanje otpada predstavlja jednu od ključnih faza formiranja deponije. Na ovaj način znatno se smanjuje zapremina otpada, ubrzava proces degradacije i produžava radni vek deponije. Zbog toga su geotehničke karakteristike komunalnog otpada prilikom zbijanja, veoma bitne kako u fazi projektovanja tako i u fazi izgradnje deponije i optimizacije prostora. Tu se pre svega misli na maksimalnu suvu zapreminsku ...
    komunalni otpad, deponija, Proktorov opit, optimalna vlažnost, maksimalna suva zapreminska težina

  • Rift sequence stratigraphy and its contribution to source rock understanding – Serbian part of Pannonian Basin

    Filip Anđelković, Dejan Radivojević (2018)
    ... sional mechanism (Matenco and Radivojević, 2012). The analysis of syn-kinematic reflectors demonstrates that normal faulting migrates in time and space and took place on a wide Miocene time interval (roughly 20–5.5 Ma) (Matenco and Radivojević, 2012). The most prolific source rocks in Serbian part ...

  • Geotehnički efekti razaranja komunalnog otpada različitim postupcima zbijanja

    Jovana M. Janković Pantić (2022)
    Odlaganje otpada na komunalne deponije predstavlja osnovni način zbrinjavanja otpada u Srbiji. Kako bi se prostor za deponovanje materijala racionalno koristio potrebno ga je svakodnevno zbijati sa unapred definisanom količinom vode koja se dodaje. Dobro zbijeni komunalni otpad zauzima manju zapreminu i omogućuje sigurnije skladištenje, pa je korisno prethodno laboratorijski odrediti parametre zbijanja: maksimalnu suvu zapreminsku težinu (dmax) i optimalnu vlažnost (wopt). U Srbiji do sada nisu određivani parametri zbijanja, dok je u svetu primenjivana standardna metoda (Proktorov opit) ...
    komunalna deponija, zbijanje, Proktorov opit, malj sa šiljcima, koeficijent razaranja