Претрага

Упит dcterms_subject_txt:Nature and Landscape Conservation

2360 items

  • Design of a sucker rod pumping system

    Ana Ponoćko (2024)
    For a long time in the history of oil production, sucker rod pumps have been the first and in many cases the only choice when it comes to mechanical extraction methods. Proper selection of each individual element of the system enables optimization, which entails benefits in the form of increased efficiency and reduced costs. The first part of the paper presents the underground and surface equipment of the rod pump and describes the operation of the entire system. The ...
    sucker rod pump, fluid production, mechanical extraction methods,, Prosper, QROD, RODSTAR
    ... initial inertia when starting the motor — The requirement for reliable speed slip due to the cyclic nature of the load Speed slip fundamentally defines the difference between the motor's no-load speed and its speed under full load [3]. 4.3 Gearbox The gearbox reduces the number of revolutions of ...
    ... of increased efficiency and reduced costs. The first part of the paper presents the underground and surface equipment of the rod pump and describes the operation of the entire system. The second part involves an analysis and calculations using the "RODSTAR", "QRod" and "Prosper" software, which ...
    ... including: maximum stress, the range of maximum and minimum stress, and the number of strokes per minute. All these factors affect material fatigue and the potential for rod failure,. In some cases, to reduce loads and investments in the lifting assembly and to increase the depth of the pump installation ...

  • 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
    ... various lexical and syntactic features of the gold standard examples, classified them and compared the results with the control corpus (both gold and control corpus are presented in Section 4). The initial set of features was inspired by Kilgarriff et al. (2008) and Kosem (2017), and guided by rec ...
    ... ) in the sentence; and since examples should help the understanding of the definition, they must be easy to understand – which means that their syntactic structure should be simple and their lexis not too difficult and uncommon. Informativeness, typicality with naturalness, and intelligibility are ...
    ... while 5% had an insertion but were not shortened and 2% had both insertions and shortenings. The number of editorial examples was relatively small, and we have not used these in our test set. 2.3.5 What should a good example contain? As Atkins and Rundell (2008) point out, there is plenty of evidence ...

  • Investigation of nanostructured Ca0.9Er0.1MnO3 obtained by sucrose nitrate procedure

    Tijana B. Vlašković, Bojana Laban, Maja Milošević, Maria Čebela, Vladimir Dodevski, Milena Rosić (2023)
    ... Technology and Metallurgy Institute for Technology of Nuclear and Other Raw Mineral Materials PROGRAM AND THE BOOK OF ABSTRACTS Serbian Academy of Sciences and Arts, Knez Mihailova 35 Serbia, Belgrade, 18-–20. September 2023. Serbian Ceramic Society Conference ADVANCED CERAMICS AND APPLICATION ...
    ... Advanced Ceramics and Application : New Frontiers in Multifunctional Material Science and Processing (11 ; 2023 ; Beograd) Program ; and the Book of abstracts / Serbian Ceramic Society Conference Advanced Ceramics and Application XI New Frontiers in Multifunctional Material Science and Processing, Serbian ...
    ... ional Material Science and Processing Serbian Ceramic Society Institute of Technical Sciences of SASA Institute for Testing of Materials Institute of Chemistry Technology and Metallurgy Institute for Technology of Nuclear and Other Raw Mineral Materials PROGRAM AND THE BOOK OF ABSTRACTS ...

  • Approach to operational mine planning: Case study Tamnava West

    Dejan Stevanović, Mirjana Banković, Milica Pešić Georgiadis, Ranka Stanković (2014)
    ... problem owing to the variable nature of coal properties (heating value, sulfur, ash), even within the same coal seam. In order to ensure a normal and efficient operation of the power plants fed with coal it is necessary to reduce the variation of the coal and that is done through coal hom ...
    ... is especially important to have enough of in situ data, and to conduct quality operational planning. The importance of operational planning for coal quality control is stressed by Stevanović et. al. 7. Also due to the complex nature of coal operational planning, usage of specialized commercial ...
    ... allow less dilution effects and greater recovery of reserves. For the case of Tamnava West minimal minable thickens of coal seam was set to 0,5 m. The final design of benches is done in Minex. Although Minex has module for bench design, due to complex nature of bench geometry for Tamnava ...

  • Anisotropic grossular–andradite garnets: Evidence of two stage skarn evolution from Rudnik, Central Serbia

    Bojan Kostić, Danica Srećković-Batoćanin, Petyo Filipov, Pavle Tančić, Kristijan Sokol (2021)
    This paper presents LA-ICP-MS data for garnets from the Rudnik skarn deposit (Serbia), which range from Grs45–58Adr40–52Alm2–3 in the core and Adr70–97Grs2–29Sps1 in the rim displaying anisotropy and zoning. In spite of wide compositional variations the garnets near the end-member of andradite (Adr > 90) are generally isotropic. Fe-rich rims exhibit LREE depletion and flat HREE pattern with weak negative Eu anomaly, including higher As and W contents. On the other side, the Fe-poorer core shows flat REE pattern ...
    grandite, garnets, skarn, Rudnik
    ... be used as a guide in prospecting Cu-skarn deposits (Somarin 2004)? Use of the rare earth elements (REE) in studies of the nature and effects of hydrothermal alterations and hydrothermal sys- tems is a relatively new method as the REE were commonly regarded as insensitive to all, except to the hy ...
    ... Mining and Geology. Conditions for microanalysis were spot size 2 µm, an accele- rating voltage of 30 kV and a beam current of 10 nA, using natural and synthetic mineral standards including albite (Al, Si), wollastonite (Ca), titanium monoxide (Ti), chromium oxide (Cr), and manganese (Mn) and iron ...
    ... grossu- lar, almandine and spessartine components. REE and trace elements The REE patterns of the studied skarn garnets are norma- lized to the chondrite value of McDonough & Sun (1995) and shown in Fig. 5. Y being a pseudolanthanide was included and plotted between Dy and Ho. Different zones during ...

  • Extensive vibrations of the belt conveyer drive electromotor of a bucket wheel excavator as a result of intesified wear-and-tear of its mount support

    Vesna Damnjanović, Predrag Jovančić, Snežana Aleksandrović (2017)

  • Phase relations and physical indicators of municipal waste from old landfills in Serbia

    Dragoslav R Rakić, Irena G Basarić Ikodinović, Jovana M Janković, Tina D Đurić (2021)
    Due to certain similarities of municipal waste and soil, usually for the determination of basic parameters of physical state, laboratory and field tests which are common in geotechnical investigations are used. It is often to construct an apparatus for special purpose to perform some specific laboratory and field tests. Therefore, different values of indicators of municipal waste physical state can be found in the literature. The basic reasons should be found in different definitions and methods that researchers use ...
    municipal waste, moisture content, unit weight, specific gravity, grain size distribution, porosityGeneral Computer Science
    ... composition of municipal waste. 3.5 Porosity Due to the complex nature of municipal waste structure (within the individual components of waste material is an interspace filled with landfill leachate, landfill gas or with gas and leachate, cither free or 'captured” gas), porosity (m) can be analysed ...
    ... consistency, biodegradability etc. (Vosniakos and Patronic, 2009). Therefore, data on the composition, shape and size of n i Ra5 o — - particles in the landfill can be of great use in defining m:;';]on and selection || > M @523331 the phase composition and physical indicators of iušLte008| Y Horanalysis| ...
    ... G) m where: mx, mya — initial dry mass and mass of drained water Žuo, }a — Initial dry unit weight and dry unit weight in degradation stage no, n — initial porosity and porosity in a certain stage of degradation Wo, W — initial moisture and moisture content in a certain stage of degradation ...

  • Mesozoic carbonate rocks in Serbia used as dimension stone

    Vesna Matović, Tijana Vojnović Ćalić (2016)
    The building industry in Serbia uses, to a great extent, imported natural stone for architectural purposes. The significance of local deposits, particularly limestones, is not adequately perceived despite the country’s abundance of these valuable resources. Therefore, this study focuses on Serbia’s Mesozoic carbonate rocks, specifically on the deposits of four selected quarries: Klisura, Skrzut, Struganik, and Tisnica. The quality and prospects of the application of these limestones has not yet been the subject of a detailed, comprehensive investigation. Therefore, ...
    Ukrasni kamen, Mezozoik, Krečnjak, Srbija, Petrografija, Fizičko-mehanička svojstva
    ... the base of the column and it is characterised by unsorted and densely packed bioclasts (up to ! mm), rare intraclasts and oncoids arranged in sparitic cement. Dominant red nodular limestone, allochemmicrite (Packstone and Wa- ckestone microfacies), builds the second and the third package of ...
    ... suitable size) and market demand (Luodes et al. 2000). Despite the fact that concrete and glass were the prin- cipal materials in architectural design during the 1970s and 1980s, in the last three decades, the demand for dimension stone has continuously increased (Siegesmund and Sneth- lage ...
    ... the limestones” scope of application as dimension stone—-slabs for architectural cladding and paving for exterior and interior use—with the possible effect on Serbia's building and stone industry, and eventually the export market. @ Springer V. Matović, T. V. Ćalić Study area The study ...

  • The state and perspective of the natural gas sector in Serbia

    Dejan Ivezić, Marija Živković, Dušan Danilović, Aleksandar Madžarević, Miloš Tanasijević (2016)
    The strategy of long-term energy development of Serbia identifies an increase of share of natural gas in final energy consumption as one of the main aims. Serbia has signed a strategic agreement with the Russian Federation on cooperation in the oil and gas sector, within which the project South Stream pipeline is planned to be realized. In addition, the Republic of Serbia has signed the Treaty that establishes the Energy Community and accepted the obligation to implement the Energy ...
    Consumption, natural gas, scenarios of development

  • Production information system of the Pljevlja coal mine

    Božo Kolonja, Ranka Stanković, Filip Vuković (2018)

  • Improvement of geodatabase queries within GeolISS

    Ranka Stanković (2008)
    ... repository for digital archiving, query, retrieving, analysis and visualization of geological data. The development and implementation of the GeolISS is managed by a team from the Faculty of Mining and Geology of Belgrade University and financed by Ministry of the Environmental protection. The main ...
    ... field data records and measurements, the basis for classification, interpretations and modeling of geological features. Any observed property can be expressed as a text, number, picture and geometry (location). Spatial entity, which is treated as observation locations and mapped/interpreted ...
    ... criteria in the source and target language. A filtered TMX document is transformed into XML, TXT and HTML output files by XSLT transformations. The developed web application receives the user query, and subsequently uses the local web service WS4QE to expand the query and forward it to the Google ...

  • The effect of finite driving rate on avalanche distributions

    Sonja Radić, Sanja Janićević, Dragutin Jovković, Đorđe Spasojević (2021)
    Statistics, Probability and Uncertainty,Statistics and Probability,Statistical and Nonlinear Physics

  • LRMI markup of OER content within the BAEKTEL project

    Ranka Stanković, Daniela Carlucci, Olivera Kitanović, Nikola Vulović, Bojan Zlatić (2015)
    ... physical and virtual communities, where more and more are published as Open Educational Resources (OER). Nowadays, online searches for educational materials are conducted more often than a few years ago. Although Internet searches are easy and speedy, they are not always efficient and retrieve ...
    ... for terminological and linguistic support, such as query expansion, information retrieval, OER indexing, and the like. OER metadata include information such as resource title, author, subject, creation date and the like, which facilitates search, but also acquisition, use and reuse of learning ...
    ... way to add extra semantic information and extend HTML5. [12] Microdata is specified inside itemtype and itemprop attributes added to existing HTML elements; microformat keywords are added inside class attributes and RDFa relies on rel, typeof and property attributes added to existing ...

  • An intelligent hybrid system for surface coal mine safety analysis

    Nikola Lilić, Ivan Obradović, Aleksandar Cvjetić (2010)

  • Arsenic in tape waters of the south Pannonian basin (Serbia) and arsenic risk assessment

    Petar Papić, Marina Ćuk, Maja Todorović, Jana Stojković, Bojan Hajdin, Nebojša Atanacković, Dušan Polomčić (2012)
    ... this study, and consequently with higher estimated toxic and carcinogenic risk should be con- nected to the new treatment for water supply. The minimum As water gave HQ and R values of 0.29 and 0.13 per 1,000 persons, respectively, and the maximum As water resulted in HQ and R of 5.72 and 2.6 per 1,000 ...
    ... existence of toxic risk. Futhermore, in the study area the minimum As water gave HQ and R values of 0.29 and 0.13 per 1,000 persons, respectively, and the maximum As water resulted in HQ and R of 5.72 and 2.6 per 1,000 persons, and this should indicate the importance of developing a regional water sup- ply system ...
    ... Austria and Slovenia to the Carpathian Mountains in Romania. In the south, the basin is bordered by the North Dinarides in Croatia, Bosnia and Herzegovina, and Serbia, and in the north by the Tatras in Slovakia. The Danube River is also the western boundary toward Croatia, while to the north and northeast ...

  • 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
    ... in addition to the ash-water. Its amount is relatively small (below 10 %) and varies depending on several factors: the nature of the fly ash, the type of additive (hydrated lime or cement), the percentage of the additive and partly of the time of exposure. Fig. 7 presents the trend of calcite formed ...
    ... with the lime content and the control sample is calculated and is 0,966, and with the cement content and the control sample is 0,954. After the calculated coefficient values it is found that the samples with the lime and the cement belong to the very strong correlation group and differ by 1 %. ...
    ... that contain the cement and the lime as the binder (of 2, 4 and 6 %) and with the control sample (100 % of the ash). The linear dependence was made for all variants, and after that the correlation coefficient was calculated. The correlation coefficient is characterized and classified in the specific ...

  • 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
    ... match completely. Author Contributions: Conceptualization, M.T. and M.C.; methodology, M.T. and D.D.; supervision, V.K.M. and B.L.; validation, D.D. and V.K.M.; formal analysis and writing—original draft M.C. All authors have read and agreed to the published version of the manuscript. Funding: This ...
    ... 1988, Valentin and Hoffman created the OPUS Expert System program, which apart from the parameters of methods and characteristics of the well and reservoir, also takes into account economic aspects (costs) [7]. In 1994, Espin and a group of authors observed technical characteristics and then economic ...
    ... fluid and working conditions, as technical limitations of artificial lift methods. The expert reviews all the parameters and decides which is the best method [6,8,10,15]. The second group (II) is expert systems: these are programs that analyze all parameters, both technical and economic, and in the ...

  • A fuzzy-based decision support model for effectiveness evaluation - a case study of examination of bulldozers

    Miloš Tanasijević, Predrag Jovančić, Dejan Ivezić, Uglješa Bugarić, Radiša Đurić (2019)
    Effectiveness evaluation is one of the basic components of engineering asset management and maintenance engineering in general. Effectiveness is an overall concept representing a measurement of quality of service level for the analyzed engineering system. This concept contains a series of partial indicators relating to time in operation and time for maintenance activities, as well as functional properties of the system. This article describes the analysis and structuring of partial indicators, as well as the development of a model ...
    Efikasnost, Fazi zaključivanje, Prikupljanje podataka, Buldozer

  • Flyrock induced by blasting in surface mining

    Milanka Negovanović, Lazar Kričak, Snežana Ignjatović, Stefan Milanović, Jovan Marković, Nikola Simić, Rade Šarac (2022)
    Miniranje predstavlja i dalje najefikasniji i najjeftiniji način eksploatacije velikih količina čvrstih mineralnih sirovina na površinskim kopovima. Energija eksplozije se koristi za fragmentaciju čvrste stenske mase do zahtevane granulacije. Pored pozitivnih efekata miniranja, postoje i određeni neželjeni efekti svakog procesa miniranja koji se mogu javiti, a to su: potresi tla, razletanje komada stene, vazdušni udari, otrovni i zagušljivi gasovi i prašina. Razletanje komada stene je nekontrolisano izbacivanje fragmenata odminirane stenske mase i predstavlja jedan od glavnih izvora materijalne štete ...
    razletanje, bušenje, miniranje, površinska eksploatacija, bezbednost, nesreća

  • Towards translation of educational resources using GIZA++

    Ivan Obradović, Dalibor Vorkapić, Ranka Stanković, Nikola Vulović, Miladin Kotorčević (2016)
    ... of them hard to translate into and with relatively weak machine translation (MT) support. Phrase-based and syntax-based SMT models are developed to address language diversity and support the language independent nature of the methodology. For high-quality MT and to add value to existing infrastructure ...
    ... University of Belgrade, 2013. [20] D. Vitas and C. Krstev. “Construction and Exploitation of X-Serbian Bitexts”. In Cristina Vertan and Walther v. Hahn (eds.) Multilingual Processing in Eastern and Southern EU Languages: Low-Resourced Technologies and Translation, pp. 207-227, Cambridge Scholars ...
    ... combined into a feedback vector and used to refine parallel data and retrain translation models towards a more accurate second-phase translation output. The project results will be showcased and tested on the Iversity [4] MOOC platform and on the VideoLectures.NET digital video lecture library ...