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Упит dcterms_subject_txt:Earth and Planetary Sciences (miscellaneous)

2210 items

  • A Fuzzy Expert Model for Availability Evaluation

    Dejan Ivezić, Miloš Tanasijević, Predrag Jovančić, Radiša Đurić (2019)
    Each technical system within itself carries the great potential danger of possible occurrence of failure and damages. Mining machines are characteristic by great investment values, costs of unplanned shutdowns, complex working conditions, and environment and workers hazards. Systematic monitoring of the mining machinery is of great importance for the management of the mining companies. Availability is the overall concept of quality of service. Includes information regard to operating state, an idle state, a standby state and shut down. The ...
    raspoloživost, ekspertski sistem, fazi teorija, buldozeri
    ... variables related to A itself and to R, M and S. It is necessary to describe five linguistic variables i.e. fuzzy sets: poor, adequate, average, good and excellent. Fuzzy sets are in triangular form, and they are presented in relation to membership function (μ) and measurement units of A indicators ...
    ... in terms of R, with grades "good" in extent of 40% and “average” in extent of 60%; M as "average" in extent of 100% and S as "adequate" in extent of 100%; machine Dressta as "average" in all terms and Caterpillar as "good" in terms of R and S and "excellent" in term of M. This can be written in the ...
    ... breakdowns and delays. The availability is commonly used as a measure of dependability. Availability is expressed by quantitative indicators, and these indicators are measures of dependability and quality of service. Availability performance has a decisive influence on the dependability and the quality ...

  • Production of electricity from coal-fired power plants and accompanying CO2 emissions: comparison of EU-27 and US

    Uroš Djorgovski, Aleksandar Madžarević, Predrag Jovančić (2023)
    Even in the third decade of the 21st century, large power plants are still responsible for more than half of the electricity production in Europe and US. They predominantly use fossil fuels in their work, which results in the emission of pollutants into the air, soil and water. In addition to the production of electric energy, fossil fuels, including coal, are used for industrial purposes. Although the use of coal, especially in the countries of the European Union, is ...
    CO2, емисија, угаљ, термоелектрана, САД, ЕУ-27
    ... regions and sectors. CO> emissions increased in North America and Asia (excluding the People's Republic of China), to a greater extent than emissions reductions in Europe and China. At the global level, CO>» emissions from electricity generation and the transport sector increased by 261 Mt and 254 ...
    ... air, soil, and water. Sector of production and use of coal also provides Jobs to around 230.000 people in mines and power plants across 31 regions and 11 EU countries [8]. Table 1. The US coal consumption in 2021 [6] Electric power | Industrial total | Commercial | Residential and transportation' ...
    ... led by increased Asian market and economic development. Global demand for electricity increased by 2.7% [4]. This paper analyzes production and emissions of CO in sector of electricity in two big worlds region - EU-27 and US. The emission of CO> in EU-27 and US in last 30 years are anatomized ...

  • 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
    ... of the substructure with defined criteria. The compaction and bearing capacity of the earth carcass layers is assessed by the static deformation modulus Ev2, which is determined by the test plate, while the control is performed by the dynamic deformation modulus Evd, which is determined by the light ...
    ... open track tracks and main tracks on main railways Ev2 > 80 MN/m2, Ev2/ 5 MN/m2, Rc* for the construction and improvement of open railway tracks and main tracks on regional railways Ev2 > 60 MN/m2, Ev2/Ev1 m2, Rc* for the construction and improvement of tracks on local railways and secondary tracks ...
    ... the standard and technical conditions (harmonized with the standard) determine in examination process the zone where soil homogeneity is ensured (by granulometric composition and moisture) and in statistically reliable research conditions. Perform the necessary tests and correlations and, based on them ...

  • Towards a Mining Equipment Ontology

    Ranka Stanković, Ivan Obradović, Olivera Kitanović, Ljiljana Kolonja (2012)
    ... management and maintenance. Basically, IT is introduced through computer-aided information systems, with the aim of securing reliable information for management and decision making in mining engineering systems [2]. Various IT maintenance support systems and tools have been developed and implemented ...
    ... entities and their values • Functions and processes entities are involved in • Constraints and rules pertaining to entities Based on these elements an ontology offers a formal representation of knowledge, through a vocabulary containing a set of concepts, semantic relationships between them and simple ...
    ... range of the data, number of decimals, and its rank for presentation in the analysis. Figure 5: Panel for defining constructive and technological equipment parameters Figure 5 depicts a panel used for overview and entry of data in technological systems and equipment assigned to them. The left ...

  • Razvoj ARCGIS geobaze površinskog kopa korišćenjem UML CASE alata

    Aleksandra Tomašević, Ljiljana Kolonja, Ivan Obradović, Ranka Stanković, Olivera Kitanović (2012)
    ... properties and relations with other objects. GIS allows users to create queries, analyze spatial information, manage data and maps, and present results of all these operations. GIS enable the user to create regional and detailed maps of both active and prospective open pits, model the geology and the terrain ...
    ... geometry (data defining the shape and size of an entity and its position in space) and topology (data defining relations between different geographic entities). Consequently, there are three basic groups of data in a GIS, namely: vector data, attribute data and raster data. Geodatabase development ...
    ... development reduces data redundancy and enables better documenting and maintenance of the entire system. The general strategy for using UML CASE tools for design and development of geodatabases entails the use of UML for defining the database schema, creation of classes, and only after that, filling with ...

  • Mitigating hydrate formation in onshore gas wells: A case study on optimization techniques and prevention

    Milica Ješić, Bojan Martinović, Stefan Stančić, Miroslav Crnogorac, Dušan Danilović (2023)
    Gas wells, particularly those situated onshore, play a vital role in the global energy sector by supplying a significant portion of natural gas. However, operational challenges, notably gas hydrate formation, pose substantial issues, leading to complications such as flowline blockages and unexpected well shutdowns. Gas hydrates, crystalline structures resembling ice, ...
    Gas Well, Gas Hydrate Formation, Well Modeling, Well Performance Optimization, Choke Position Adjustments, Methanol Injection

  • Maturation and isotopic changes of individual hydrocarbons in lignite lithotypes through diagenesis and early catagenesis

    Ivan Kojić, Achim Bechtel, Reinhard Sachsenhofer, Dragana Životić, Ksenija Stojanović (2019)
    ... fractions of lignite extracts and pyrolysis prođucts are садајепе and retene. The matunty ratios based оп trimethyinaphthalenes (ТММЕ) and tetramethyinaphthalenes (TeMNr) slightly increase from Pyr400 to Pyr500. The same 15 тејајед to methylfluorene (МЕ) гано (2-+3-MF)/(1-+4-MF) and methyiphenanthrene (МР) ...
    ... Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs MATURATION AND ISOTOPIC СНАМСбЕ5 ОЕ INDIVIDUAL HYDROCARBONS IN LIGNITE LITHOTYPES THROUGH DIAGENESIS AND EARLY CATAGENESIS ...
    ... 400 "С and 500 %C. Aliphatic апд aromatic fractions isolated from lignite extracts and hquid pyrolysis prođucts were analyzed by gas chromatography-mass spectrometry. Carbon isotope determinations (65С) of indiviđual compounds in these fractions were also performed. Compositions ог апрћанс and aromatic ...

  • Evaluation of the effects of wastewater heat pump integration into district heating systems by simulation

    Dejan Ivezić, Marija Živković, Dimitrije Manić, Aleksandar Madžarević, Boban Pavlović, Dušan Danilović (2023)
    The integration of wastewater heat pumps (using purified water) in district heating systems is analyzed in this paper. The simulation procedure is proposed to analyze the impacts of stochasticity of purified water temperature and flow to heat pump integration and operation. The analysis includes calculation of the daily and seasonal coefficient of performance, as well as fossil fuel savings and CO2 emission reduction due to wastewater heat pump use. The proposed procedure is implemented for the case study in ...
    otpadne vode, toplotna pumpa, daljinsko grejanje, simulacija

  • Coal homogenization stockyard sizing “Tamnava – Zapad” case study

    Božo Kolonja, Dinko Knežević, Ranka Stanković, Dejan Stevanović, Detlef Trummer (2016)
    ... can be used to calculate, plan, control and predict the quality of ore being stacked and/or reclaimed with a great degree of accuracy. Robinson (2004) presents mathematical and computer models for the geometry of a stockpile, using both actual grade data and a variogram to describe the input variation ...
    ... chevron and window methods. Given than the windrow method is technologically more complex and requires the use of more complicated and more expensive machines, the chevron method is generally more desirable. There is no general rule defining which number of layer is considered small and which ...
    ... causes problems in organizing operations at the stockyard and arranging coal stacking and reclaiming. Namely, the rule is that piles are alternately filled and emptied, so that when the pile is being filled it is filled completely, and emptied completely when being emptied. In the example of coal ...

  • A comparative study of the molecular and isotopic composition of biomarkers in immature oil shale (Aleksinac deposit, Serbia) and its liquid pyrolysis products (open and closed systems)

    Gordana Gajica, Aleksandra Šajnović, Ksenija Stojanović, Jan Schwarzbauer, Aleksandar Kostić, Branimir Jovančićević (2021)
    The molecular and isotopic composition of biomarkers in initial bitumen isolated from immature (0.41% Rr) oil shale samples (Aleksinac deposit) and liquid products obtained by pyrolysis in open (OS) and closed (CS) systems are studied. The influence of pyrolysis type and variations of kerogen type on biomarkers composition and their isotopic signatures in liquid products is determined. The applicability of pyrolysis type, numerous biomarkers and carbon isotopic compositions (δ13C) of n-alkanes in liquid pyrolysates is established. Pyrolysis experiments were ...
    Uljni šejl, Aleksinac, organska supstanca, otvoreni i zatvoreni sistem pirolize, biomarkeri, izotopski sastav ugljjenika

  • 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

  • From DELA Based Dictionary to Leximirka Lexical Database

    Biljana Lazić, Mihailo Škorić (2020)
    In this paper, we will present an approach in transforming Serbian language Morphological dictionaries from a DELA text format to a lexical database dubbed Leximirka. Considering the benefits of storing data within a database when compared to storing them in textual documents, we will outline some of the functionality that the database has made possible. We will also show how hand-made rules that use category labels lexical entries are marked with can be used to link lexical entries. ...
    Morfološki rečnici, jezički resursi, Leksimirka
    ... simple and multiword units. The basic components of the simple word morphological vocabulary system are DELAS (fr. DELA de formes simple) and DELAF (fr. DELA de formes Fléchies) (Courtois and Silberztein, 1990). A single DELAS entry consists of a word lemma and its inflective, semantic, and syntactic ...
    ... compound nouns “NC” and grammatical categories for the masculine “m”, the plural “p”, accusative case “4” and the animateness tag for living beings - “v”. For the sake of simplicity, semantic and domain markers were omitted in the example. All types of dictionaries were stored and used in the form of ...
    ... from the morphological dictionaries and to make them in- teroperable and reusable. Three standards for lexical information have been considered: Guidelines for Electronic Text Encoding and Interchange, Text Encoding Initiative (TEI)3, Lexical Markup Framework (LMF)4 and the Lemon model5. Although Chapter ...

  • The Potential of Biomarkers to Distinguish Lower and Middle Miocene Lignites from the Coal-Mining District of Lusatia

    I. Kojic, J. Kus, D. Zivotic, K. Stojanovic (2021)
    ... Cupressaceae and Phyllocladaceae, whereas cuparene and dehydroicetexane are specific for Cupressaceae (Nytoft et al., 2019). Slight input of aquatic macrophytes and ferns is also evident. The degrees of aromatization of diterpenoids and non-hopanoid pentacyclic triterpenoids (Stojanović and Životić ...
    ... greater contribution of angiosperms. The contents of C27 and C29 n-alkanes in relation to C31 and C33 homologues imply similar impact of forested and reed-mire vegetation. The presence of tricyclic (abietane, pimarane, isopimarane) and tetracyclic (phyllocladane, bayerane, kaurane) diterpenoids ...
    ... DISTINGUISH LOWER AND MIDDLE MIOCENE LIGNITES FROM THE COAL-MINING DISTRICT OF LUSATIA I. Kojić1, J. Kus2, D. Životić1, K. Stojanović1 1University of Belgrade, Serbia 2Federal Institute for Geosciences and Natural Resources, Germany The organic geochemical study of Lower and Middle Miocene ...

  • Advantages and Disadvantages of a Parallel and Zigzag Method of Acquisition in Walking Mode in Magnetometric Archeological Research

    Mirko Petković, Vesna Cvetkov, Branislav Sretenović (2014)
    магнетометријска испитивања, цик-цак и паралелна аквизиција у ходајућем моду, линеарне аномалије, археологија
    ... entation of the traverses and a combination of with and without Global Positioning System (GPS). The sampling time was set to 1 s and the dis- tance between the traverses to 1 m in order to obtain a regular data grid with the same spacing between the points along the x and y directions. DATA ACQUISITION ...
    ... orientation of profi les, and all the data Archaeology and Science 10 (2014) 96 Petković et al - Advantages and Disadvantages of a Parallel...(93-110) Fig. 3 Contour m ap of a vertical gradient of TM I in N -S orientation. K ey as for Fig 1. 97 Archaeology and Science 10 (2014)Petković et ...
    ... 99 Archaeology and Science 10 (2014)Petković et al - Advantages and Disadvantages of a Parallel...(93-110) Fig. 5 Contour m ap of a vertical gradient of TM I in E-W orientation. K ey as for Fig 1. Archaeology and Science 10 (2014) 100 Petković et al - Advantages and Disadvantages of a Parallel ...

  • Application of ERT in the study of debris-flow source area: Case study Selanac debris flow

    Dragana Đurić, Jelka Krušić, Biljana Abolmasov (2021)

  • 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
    ... (more detailed coordinates in the Gauss-Kruger coordinate system are given in Figures 2 and 3). Figure 1. Position and spatial organization of the planned Maestrale Ring wind farm. (Source: Google Earth with modifications). According to the concept of the planning document, the wind farm is ...
    ... , hospital zones and convalescent homes, cultural and historical sites, large parks 50 40 2 Tourist areas, camps and school zones 50 45 3 Residential areas 55 45 4 Business/residential and commercial/residential areas and children’s playgrounds 60 50 5 Town/city center, business, adm ...
    ... possible negative effects on human health, which Pedersen and Waye [30] classify into three groups: subjective effect (discomfort, disturbance and dissatisfaction); interference with certain daily activities (speech, sleep and learning); and physiological effect (anxiety, tinnitus, or in the worst ...

  • Mine surveying works for the purpose of excavating the remaining reserves of bauxite in the deposit of “Podbracan”

    Aleksandar Milutinović, Aleksandar Ganić, Thamer Rayes Diyab, Rade Tokalić, Meri Ganić (2015)
    ... are vastly spread both horizontally and vertically (approximately 300m in thickness) and discordantly lies over the older beds. They are consisted of sandy and grav- elly clays, clayly and ironaceus quartz sands and semi-consolidated sand- stones, laterally and vertically shifting on the bauxite ...
    ... adit (GIP) to the surface, and afterwards with the same truck to the ore dump location. A special feature of this project requires an analytical and systematic approach when de�ning the existing spatial position and geometry, and setting out structures designed at and under the terrain surface ...
    ... mining and surveying tasks during the pre-project and project stage of mining, as well as during the construction of mining facilities and excavation of mineral resources. Speci�c features of the project concerning excavation of the remaining reserves of bauxite in the deposit of "Podbracan", and in this ...

  • Synergy between the mineral deposit exploration and geothermal resources assessment on the example of "Valjevo" boron and lithium deposit in Serbia

    Nebojša Atanacković, Vladimir Živanović, Ana Vranješ, Sava Magazinović, Marinko Toljić, Ana Arifović, Branislav Potić (2023)
    Exploration of mineral deposits involves a collection of vast data sets on geological characteristics of the area. These data can largely contribute to the assessment of the geothermal potential, which can lead to an increase in the share of geothermal resources in the energy mix of the extractive industry and the local community. On the example of the "Valjevo" B-Li deposit, data on structural settings and previous hydrogeological investigations were combined with the results of resource drilling and geophysical ...
    Geothermal assessment, Mineral deposit exploration, Geothermal potential, Serbia
    ... Mionica and surrounding settlements. Karst groundwater under artesian pressure and elevated temperatures (17–37 "C) are taped with wells drilled below the Miocene cover in the surrounding. settlements of Paštrić, Sanković and Petnica. 3. MATERIALS AND METHODS Considering the available data and the ...
    ... probertite, ulexite, sirlezite, massive borax and Li-bearing smectite and silinaite minerals, deposited in three main zones: Borate zone, Borax zone and Lithium-borate zone. The basin basement in the north part is dominated by lower Triassic clastic and Paleozoic metamorphic sediments, while to the ...
    ... deposit exploration and geothermal resources assessment on the example of "Valjevo" boron and lithium deposit in Serbia | Nebojša Atanacković, Vladimir Živanović, Ana Vranješ, Sava Magazinović, Marinko Toljić, Ana Arifović, Branislav Potić | Proceedings 9th International Conference mining and environmental ...

  • Cutting Resistance Laboratory Testing Methodology for Underwater Coal Mining

    Vladimir Čebašek, Veljko Rupar, Stevan Đenadić, Filip Miletić (2021)
    Geology,Geotechnical Engineering and Engineering Geology
    ... Validation, V.R., S.Ð., and F.M.; Formal analysis, V.R.; Investigation, V.Č. and V.R.; Resources, V.Č. and V.R.; Data curation, V.R., S.Ð., and F.M.; Writing—original draft preparation, V.Č.; Writing—review and editing, V.R.; Visualization, S.Ð. and F.M. All authors have read and agreed to the published ...
    ... FL—lateral, and FFT—forward thrust). In the past, the relationship between digging material and specific digging resistance for wheel operation has been analyzed both theoretically and practically. The most critical researchers have been Himmel, Limbrek and Marcelli, Brach, Dombrowski, and Kubec [1,14] ...
    ... with 38 mm in diameter and 76 mm in height. The samples were subjected to the confining pressure equal to σ3 = 400, 800, and 1600 kPa. A vertical force loaded the samples, and the vertical deformation rate was constant. The vertical force is measured using a compression ring, and the vertical movement ...

  • The application of ArcGIS for assessing the potential of solar energy in urban area: The case of Vranje

    Boban Pavlović, Milica Pešić-Georgiadis (2019)
    In order to determine the solar energy potential for a specified location, it is crucial to consider the latitude, altitude, slope, terrain morphology, atmospheric conditions, etc. Such a complex calculation and mapping of solar energy can be done using the ArcGIS geoprocessing tool, named Area Solar Radiation (ASR). By using the ASR tool, supported with the adequate input data, it is possible to calculate the maximum solar radiation energy (irradiation) for a defined area and for a specified time ...
    Obnovljivi izvori energije, potencijal solarne energije, GIS, mapiranje solarnog potencijala
    ... radiation is the primary source of energy for many physical and biological processes on Earth and it is one of the basic preconditions for the existence of the living world. In essence, energy received from the Sun is in the form of light and thermal energy. When considering the total impact of the ...
    ... (Diro,), with a centroid at zenith angle (0) and azimuth angle (a), is calculated using the following equation (3): Diroa = Scomt * BpmĆ) * SunDuroa * SunGapo, * cos(Angine,) (3) where: Scomst = The solar flux outside the atnosphere at the mean earth-sun distance, known as solar constant. ...
    ... energy, and energy in biomass and · fossil fuels, · captured · through photosynthesis. For the purpose of heating and electricity production, the application of solar panels (solar thermal panels for heating: water and PhotoVoltaic (PV) solar panels for electricity 325 production) and the ...