Претрага

Упит dcterms_subject_txt:General Materials Science

841 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
    ... should ensure adequate clearance and fluid flow with minimal pressure drop. The API specification pertains only to the dimensions and not to the materials of the component. The ball and seating nipple constitute the valve. API valves are designed to operate within API valve bodies. Additional ...
    ... tubing string, allowing for partial replacement of damaged underground equipment and reducing maintenance time. The option to choose different materials for the moving and stationary parts of the pump, along with a variety of design solutions, makes this type of pump adaptable to different exploitation ...
    ... through the space (clearance) between the plunger and the cylinder is determined based on experimental data and is expressed in various forms. The general equation for fluid loss through the clearance between the plunger and the cylinder is given by [15,19]: dAxAp*6B „ d4 H*L qs =K 3.1 • qs= fluid ...

  • The interaction of organoselenium trans-palladium(II) complexes toward small-biomolecules and CT-DNA

    Vera M. Divac, Aleksandar Mijatović, Marina D. Kostić, Jovana Bogojeski (2017)
    Serija organoselenijum trans-paladijum(II) kompleksa 1 (bis(2-(fenilselanilmetil)oksolan)dihloropaladijum(II)), 2 (bis(2-(fenilselanilmetil)oksan)dihloropaladijum(II)) i 3 (bis(2) ,2-dimetil-3-(fenilselanil)oksan)dihloropaladijum(II)) su korišćeni za ispitivanje reaktivnosti ovog specifičnog tipa kompleksa prema različitim bio-molekulima. Ovaj sistem je od posebnog interesa jer se jako malo zna o supstitucionim reakcijam organoselenijum paladijum(II) kompleksa sa trans konfiguracijom. Zamena koordinovanog hlorida sa serijom malih bio-molekula (l-Met, l-His, l-Cis, GSH i 5′-GMP) proučavana je pod uslovima pseudo-prvog reda kao funkcija koncentracije nukleofila i temperature korišćenjem tehnika zaustavljenog toka. Rezultati za proučavane komplekse ukazuju da ...
    Pd(II), Selen, Substitucija, Kinetika, Mehanizam

  • Two approaches to compilation of bilingual multi-word terminology lists from lexical resources

    Branislava Šandrih, Cvetana Krstev, Ranka Stanković (2020)
    In this paper, we present two approaches and the implemented system for bilingual terminology extraction that rely on an aligned bilingual domain corpus, a terminology extractor for a target language, and a tool for chunk alignment. The two approaches differ in the way terminology for the source language is obtained: the first relies on an existing domain terminology lexicon, while the second one uses a term extraction tool. For both approaches, four experiments were performed with two parameters being ...
    Linguistics and Language,Software,Artificial Intelligence,Language and Linguistics

  • Ефикасност дистрибуције и коришћења природног гаса у домаћинствима

    Dejan Brkić (2010-03-30)
    Природни гас ће се у будућности све више користити као енергент за подмиривање грејних потреба становништва у српским градовима. Стога је потребно изнаћи најповољнији начин употребе природног гаса. Природни гас се може користити за подмирење грејних потреба становништва на два дијаметрално супростављена начина, и то директно, тако што би се гас директно уводио у зграде путем дистрибутивног система за снабдевање гасом и затим сагоревао у гасном котлу којим је сваки стан опремљен (гасни дистрибутивни систем), или индиректно, тако што ...
    prirоdni gаs, distribuciја gаsа,grејаnjе, cеvоvоdi, cеvоvоdnе mrеžе,fаktоr trеnjа pri prоtоku fluidа,urbаnizаm
    ... nt of  Energy, Water and Environment Systems (2009) научни скуп у организацији UNESCO  (United Nation Education, Science and Culture Organization) и TWAS (Third World  Academy of Science), Дубровник, Хрватска, 29. септембар‐4. октобар 2009,  уредници: Звонимир Гузовић, Невен Дуић, Марко Бан (ISBN 97 ...
    ...  (на српском)  227. Rao, A.R., Kumar, B. 2007. Friction factor for turbulent pipe flow. Preprint: Division of  Mechanical Science, Civil Engineering, Indian Institute of Science, Bangalore, India, ID  Code 9587, (from: http://eprints.iisc.ernet.in/9587/) (на енглеском)  228. Ramalingam, D., Lingireddy ...
    ... 64. Caillol, J.M. 2003. Some applications of the Lambert W function to classical statistical  mechanics. Journal of Physics A: Mathematical and General 36(42), 10431–10442. (на  енглеском)  65. Calzetta, E. 2009. Friction factor for turbulent flow in rough pipes from Heisenberg’s  closure hypothesis ...

  • Ефикасност дистрибуције и коришћења природног гаса у домаћинствима

    Dejan Brkić (2010-03-30)
    Природни гас ће се у будућности све више користити као енергент за подмиривање грејних потреба становништва у српским градовима. Стога је потребно изнаћи најповољнији начин употребе природног гаса. Природни гас се може користити за подмирење грејних потреба становништва на два дијаметрално супростављена начина, и то директно, тако што би се гас директно уводио у зграде путем дистрибутивног система за снабдевање гасом и затим сагоревао у гасном котлу којим је сваки стан опремљен (гасни дистрибутивни систем), или индиректно, тако што ...
    prirоdni gаs, distribuciја gаsа,grејаnjе, cеvоvоdi, cеvоvоdnе mrеžе,fаktоr trеnjа pri prоtоku fluidа,urbаnizаm
    ... nt of  Energy, Water and Environment Systems (2009) научни скуп у организацији UNESCO  (United Nation Education, Science and Culture Organization) и TWAS (Third World  Academy of Science), Дубровник, Хрватска, 29. септембар‐4. октобар 2009,  уредници: Звонимир Гузовић, Невен Дуић, Марко Бан (ISBN 97 ...
    ...  (на српском)  227. Rao, A.R., Kumar, B. 2007. Friction factor for turbulent pipe flow. Preprint: Division of  Mechanical Science, Civil Engineering, Indian Institute of Science, Bangalore, India, ID  Code 9587, (from: http://eprints.iisc.ernet.in/9587/) (на енглеском)  228. Ramalingam, D., Lingireddy ...
    ... 64. Caillol, J.M. 2003. Some applications of the Lambert W function to classical statistical  mechanics. Journal of Physics A: Mathematical and General 36(42), 10431–10442. (на  енглеском)  65. Calzetta, E. 2009. Friction factor for turbulent flow in rough pipes from Heisenberg’s  closure hypothesis ...

  • Optimisation of underground mine decline development system using genetic algorithm

    Zoran Gligorić, Aleksandar Ganić, Rade Tokalić, Aleksandar Milutinović (2014)
    ... slope that can be handled by loaded mine truck in a safe way. Decline optimisation is concerned of determination of locations of SBP and UMCP. A general design optimisation problem is formulated as follows: Optimisation of underground mine decline ... ...
    ... (2014) A novel hybrid genetic differential evolution algorithm for constrained optimization problems. International Journal of Advanced Computer Science and Applications, 3 (6), pp.6-12. 2 BRAZIL, M. et al. (2003) Optimising Declines in Underground Mines. Mining Technology. 112 (3), pp.164-170 ...

  • The optimization of auxiliary machinery in open-cast lignite mines: a case study of bulldozers

    Dragan Ignjatović, Predrag Jovančić, Stevan Đenadić, Ivan Janković, Ivica Ristović (2019)
    One of the most important prerequisites for the successful operation of the open-cast lignite mine is to carry out all the auxiliary works timely with the necessary quality. The most important and most commonly used auxiliary machines are bulldozers. Engaging time of bulldozers use is in direct relation with the coefficients of the time and capacity utilization of the continuous system for the excavation of coal and tailings, which indicates their importance. More than 100 bulldozers have been hired ...
    open-cast coal mine, auxiliary works, bulldozers, optimization, availability
    ... g application in mines for the purpose of increasing work safety and production efficiency” (TR 33025), financed by the Ministry of Education and Science of the Republic of Serbia within the framework of Programme of research in the field of technological development for the period 2011-2019. REFERENCES ...

  • Energetska efikasnost elektromotora na površinskim kopovima

    Snežana Aleksandrović, Ilija Jeftenić (2023)

  • Improving Document Retrieval in Large Domain Specific Textual Databases Using Lexical Resources

    Ranka Stanković, Cvetana Krstev, Ivan Obradović, Olivera Kitanović (2017)
    Large collections of textual documents represent an example of big data that requires the solution of three basic problems: the representation of documents, the representation of information needs and the matching of the two representations. This paper outlines the introduction of document indexing as a possible solution to document representation. Documents within a large textual database developed for geological projects in the Republic of Serbia for many years were indexed using methods developed within digital humanities: bag-of-words and named ...
    ... search retrieves only 169 of them, some of which refer to a municipality council, others to salt. Faceted search in general improves ranking within the initial system. Namely, if a “general search” is performed instead of a faceted search for the query “Tamnava or Ub and coal or lignite” the document “Coal ...
    ... retrieval results of indexed documents for a specific query and the results were compared with the initial retrieval system that was already in place. In general, a significant improvement has been achieved according to the standard information retrieval performance measures, where the InQuery method performed ...
    ... retrieval results of indexed documents for a specific query and the results were compared with the initial retrieval system that was already in place. In general, a significant improvement has been achieved according to the standard information retrieval performance measures, where the InQuery method performed ...

  • Analiza primenjenih metoda za transport parafinske nafte

    Dunja Milojević (2024)
    Sadržaj parafina u nafti ima dominantan uticaj na svojstva parafinskih nafti. Taloženje parafina, odnosno taloženje čvrstih čestica parafinskog voska, predstavlja ozbiljan globalni problem tokom proizvodnje i transporta sirove nafte. Samo taloženje voska zavisi od termodinamičkih faktora, poput temperature, pritiska i sastava nafte. Transport nafte cevovodima je uobičajeni proces transporta u naftnoj industriji. Kada prilikom cevovodnog transporta parafinske sirove nafte, dođe do prekida protoka i hlađenja nafte ispod temperature stinjavanja, parafini će kristalisati, pri čemu će doći do, geliranja celokupne transportovane ...
    nafta, parafinski vosak, taloženje, transport, naftovod
    ... Tehnika - Klektrotehnika, 60, str. 606-610. 9. Doeble, K. (2018). Wax Deposition as a Function of Flow Regimes. Norway: Norwegian University of Science and Technology. 10.Elmabrouk Ali Elhaddad, E. (2014). NOV!I MODEL ZA POSTIZANJE OPTIMALNE PROIZVODNJE NA NAFTNOM POLJU AMAL. Beograd: Univerzitet ...
    ... fakultet. 11. Guozhong, Z., & Gang, L. (2010). Study on the wax deposition of waxy crude in pipelines and its application. Journa! of Petroleum Science and Engineering. 12.iStock. (n.d.). Oil pipeline images. Preuzeto sa istock: https://www.istockphoto.com/search/2/image- film?phrase=oil%20 ...
    ... 60(1-2), str. 10-14. 18.Stubsjden, M. (2013). Analytical and Numerical Modeling of Paraffin Wax in Pipelines. Norway: Norwegian University of Science and Technology. 19. Tolmač, J. (2020). Opfimizacija termičkih i hidrauličkih parametara transporta sirove nafte cevima. Zrenjanin: Univerzitet ...

  • Претрага корпуса заснована на употреби екстерних лексичких ресурса путем веб-сервиса

    Милош Утвић, Ранка Станковић, Александра Томашевић, Михаило Шкорић, Биљана Лазић (2019)
    У раду се разматра хибридни приступ претрази корпуса, илустрован на примеру алатки OCWB и NoSketch Engine, примењених на специјални корпус из области рударства (РудКор) и Корпус савременог српског језика (СрпКор). Разматрани приступ комбинује постојеће могућности алатки OCWB и NoSketch Engine, које своју претрагу заснивају на лингвистичкој анотацији корпуса, са новим могућностима претраге у виду консултовања екстерних језичких ресурса (морфолошки електронски речници српског језика и лексичка база података Српски ворднет). Хибридни приступ је реализован надоградњом вебсучеља која поменуте алатке користе ...
    корпус, рударство, претраживање информација, проширивање упита, лексички ресурси, лексичке релације
    ... Pavlović-Lažetić, Duško Vitas and Ivan Obradović, “Using Textual and Lexical Resources in Developing Ser- bian Wordnet”, Romanian Journal of Information Science and Technology, 7/1–2, 147–161. Крстев 2008: Cvetana Krstev, Processing of Serbian — Automata, Texts and Elec- tronic Dictionaries. Belgrade: Faculty ...
    ... In: N. Nguyen, R. Kowalczyk, A. Pinto, J. Cardoso (eds) Transactions on Computational Collective Intel- ligence XXVI, Lecture Notes in Computer Science, 10190, Cham: Springer, 162–185. DOI: 10.1007/978-3-319-59268-8_8, https:/doi.org/10.1007/978- 3-319-59268-8_8. Станковић и др. 2018: Ranka Stanković ...

  • Hidrogeohemija prirodnih radioaktivnih elemenata u podzemnim vodama Srbije

    Marina D. Ćuk (2018-02-23)
    Osnovni cilj doktorske disertacije predstavljao je definisanje prirodnih koncentracija (engl. background values) U, Th, i K u podzemnim vodama, i definisanje hidrogeohemijskih uslova koji utiču na distribuciju navedenih elemenata u podzemnim vodama...
    prirodni radioaktivni elementi, podzemna voda, geohemijske sredine, hidrogeohemijski uslovi, neparametarska statistička analiza, logistički model, hidrohemijsko modeliranje
    ... large-scale groundwater bodies in Northern Italy. Science of The Total Environment 425: 9 – 19. 114. Molinari A, Chidichimo F, Straface S, Guadagnin A. 2014. Assessment of natural background levels in potentially contaminated coastal aquifers. Science of the Total Environment 476/477: 38 – 48. ...
    ... nlm.nih.gov/pubmed/?term=Liu%20J%5Bauth%5D http://www.ncbi.nlm.nih.gov/pubmed/?term=Merchant%20N%5Bauth%5D 170 100. Marinović Đ. 1982. The general geological and hydrogeological conditions in the province of Vojvodina. Proceedings. VII Yugoslav Symposium of hydrogeology and engineering geology ...
    ... (Toth 1970, 1971, 1972). Koncept regionalnog toka podzemnih voda je tokom poslednjih 50 godina napravio značajan http://www.sciencedirect.com/science/article/pii/S167498711100020X#bib36 23 napredak u hidrogeologiji posluživši kao osnova za izradu velikog broja konceptualnih modela. Cirkulacija ...

  • Процена ризика од загађивања водних ресурса под утицајем напуштених рударских радова на простору Србије

    Nebojša B. Atanacković (2018-08-31)
    Велики број напуштених рударских радова и ограничена средства за рекултивацијуи ремедијацију деградираних простора подстакле су развој метода за издвајањеприоритетних локација на које је потребно усмерити даља истраживања. У датомконтексту, у склопу израде дисертације спроведене су научно-истраживачкеактивности које су за предмет имале анализу утицаја значајнијих напуштенихрударских радова на водне ресурсе на простору Србије јужно од Саве и Дунава.Разматрање предметне проблематике извршено је кроз развој и примену семи-квантитативне методологије за анализу ризика од загађивања површинских иподземних вода на регионалној размери. Примењена ...
    анализа ризика, водни ресурси, водна тела, рудничке воде, рударскиотпад, аналитички хијерархијски процеси, кластер анализа, математичка теоријаатрибута, функције припадности, семи-квантитативне методе
    ... applications and trends. Science of The Total Environment 409(19): 3578-3594. doi 10.1016/j.scitotenv.2011.06.022 70. Hudson-Edwards K.A., Macklin M.G., Brewer P.A. and Dennis I.A. (2008) Assessment of Metal Mining-Contaminated River Sediments in England and Wales. Science Report: SC030136/SR4. ...
    ... Зборник радова XVI Конгрес геолога Србије, Доњи Милановац. 101. Markowski A.S. & Mannanb M.S. (2008) Fuzzy risk matrix. Journal of Hazardous Materials 159: 152–157. doi 10.1016/j.jhazmat.2008.03.055 102. Massart D.L. and Kaufman L. (1983) The Interpretation of Analytical Chemical Data by the Use ...
    ... Vulnerability and Risk Mapping for the Protection of Carbonate (Karstic) Aquifers. Final report COST action 620. European Commission, Directorate-General for Research, Brüssel. 194. Živanović V., Dragišić V., Atanacković N., Ninković S., Magazinović S. (2015) Izrada karte rizika od zagađivanja podzemnih ...

  • Методологија интегралне анализе сценарија енергетског развоја

    Александар Маџаревић (2019)
    енергетска безбедност, сценарио развоја, фази логика, сигурност снабдевања, доступност, расположивост, природни гас
    ... доступно на: https://www.sciencedirect.com/science/article/pii/S0301421509000640 Lisiakiewicz R., Poland's conception of European security and Russia, Communist and Post-Communist Studies, Article in press, 2018., доступно на: https://www.sciencedirect.com/science/article/pii/S0967067X18300199 Bouwmeester ...
    ... https://www.sciencedirect.com/science/article/pii/S030142151730174X Richter P.M., Holz F., All quiet on the eastern front? Disruption scenarios of Russian natural gas supply to Europe, Energy Policy, Volume 80, 2015, pp. 177-189, доступно на: https://www.sciencedirect.com/science/article/pii/S0301421515000336 ...
    ... w.sciencedirect.com/science/article/pii/S1877042815031262 АЛЕКСАНДАР МАЏАРЕВИЋ 183 ЛИТЕРАТУРА Tsereteli M., Can Russia's Quest for the New International Order Succeed?, Orbis, Volume 62/2, 2018, pp. 204-219, доступно на: https://www.sciencedirect.com/science/article/pii/S0030438718300085 ...

  • Gate Road Support Deformation Forecasting Based on Multivariate Singular Spectrum Analysis and Fuzzy Time Series

    Luka Crnogorac, Rade Tokalić, Zoran Gligorić, Aleksandar Milutinović, Suzana Lutovac, Aleksandar Ganić (2021)
    Underground mining engineers and planners in our country are faced with extremely difficult working conditions and a continuous shortage of money. Production disruptions are frequent and can sometimes last more than a week. During this time, gate road support is additionally exposed to rock stress and the result is its progressive deformation and the loss of functionality of gate roads. In such an environment, it is necessary to develop a low-cost methodology to maintain a gate road support system. ...
    deformacije podgrade, lasersko skeniranje, višekanalna singularna spektralna analiza, prognoza, klasterisanje fuzzy vremenskih serija
    ... based on a support vector machine, for tunnel surrounding rock displacement forecasting. This paper is divided into five sections. In the section Materials and Methods, we de- scribe the model of forecasting based on observed data and multivariate singular spectrum analysis. We introduce the fuzzy time ...
    ... be concluded that the model is reliable and applicable for solving real-time problems in terms of predicting gate road support deformations. 2. Materials and Methods 2.1. Dynamic of Support Deformations The dynamic behavior of support is induced by the rock stress surrounding the gate road. Deformation ...
    ... Economics Data. J. Syst. Sci. Complex. 2009, 22, 372–394. [CrossRef] 14. Hassani, H.; Mahmoudvand, R. Multivariate Singular Spectrum Analysis: A General View and New Vector Forecasting Approach. Int. J. Energy Stat. 2013, 1, 55–83. [CrossRef] 15. Kalantari, M.; Hassani, H. Automatic Grouping in Singular ...

  • 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

  • Business Models for Small-scale Biomass Projects Development

    Dejan Ivezić, Miodrag Gluščević, Marija Živković (2019)
    Biomass is recognized as the most promising renewable energy source in Serbia. The share of biomass in Serbian final energy consumption is over 10%, but mostly related to traditional use in stoves and ovens. One of the main obstacles for wider implementation of contemporary biomass facilities is the inexperience of consumers and stakeholders in the implementation of “innovative” business models, especially in the cases of small-scale projects. In this paper, three different business models (public utility company, energy cooperative ...

  • Numerical modeling of Selanac debris flow propagation using SPH code

    Jelka Krušić, Biljana Abolmasov, Miloš Marjanović, Manuel Pastor, Saeid M. Tayyebi (2021)
    The Selanac debris flow is a very huge event triggered after extreme rainfall caused by Cyclone Tamara activity in the Republic of Serbia in May 2014. The Selanac case study was already modelling in different programs using Voellmy rheology assumptions like RAMMS software. In this paper research are focusing particularly on the process of debris flowing from initiation zone to main deposition area using Geoflow SPH two-phase model considering frictional rheology law. Main rheological parameters are back-calculated using also ...
    debris flow, modelling, SPH code, DEM
    ... Japan and the UNDP Office in Serbia (grant No 00094641). All activities are also a part of the Project TR36009 funded by the Ministry of Education, Science and Technological Development of the Republic of Serbia. 7 REFERENCES Chen, C. and Ling, C.H. (1996). ‘’Granular-Flow Rheology: Role of Shear-Rate ...

  • Self-Engineering: Possibilities for Maintenance Operations in the Mining Machines Industry

    Steven Manders, Milorad Pantelić, Vladimir Milisavljević, Alberto Martinetti (2021)
    Self-engineering is a relatively new branch of knowledge that aims to understand how systems could “autonomously” re-configure or repair themselves without the intervention of the operators. A direct field of application is within the maintenance spectrum. Having systems or machines capable of self-detecting or even self-repairing could represent a game-changer, in capital asset fields such as the mining industry in particular. This paper aims to investigate the possible benefits and challenges of self-engineering / self-maintenance concerning mining machines, specifically bucket-wheel ...
    self-engineering, self-maintenance, maintenance operations, mining industry, bucket-wheel excavator, gearbox revitalization

  • Mikroorganizmi - biohidrogeološki indikatori odabranih pojava mineralnih voda Srbije

    Vladimir Šaraba (2021)
    Sa namerom definisanja hidrogeološke uloge i značaja mikrobiološkog diverziteta odabranih pojava mineralnih voda Srbije, primenom sistema biodetektora, dokazano je prisustvo gvožđevitih, sulfato-redukujućih, sluz-produkujućih, heterotrofnih aerobnih i denitrifikacionih bakterija, na osnovu čega je proračunat rizik od razvoja procesa biokorozije i biohemijske inkrustacije, te zdravstveni rizik. Uz procenu rizika, izvedene su analize skenirajuće elektronske mikroskopije biofilmova i hidrogeohemijsko modeliranje, te makroskopska, otpička i difrakciona ispitivanja naslaga inkrustacije, dok je fizičko-hemijskim analizama utvrđena vrednost ukupne mineralizacije iznad 1 g/L, kao i povišeni ...
    biohidrogeologija, SEM analize, makroskopska i optička ispitivanja, rendgenska difrakcija praha, hidrogeohemijsko modeliranje, BART analize, metabarkoding analize mikrobioma, fizičko-hemijske analize, starenje bunara (biokorozija, biohemijska inkrustacija i biozarastanje), zdravstveni rizik
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    ... 1016/B978-0-12- 800021-2.00025-X Blackwood, D. J. (2020). An electrochemist perspective of microbiologically influenced corrosion. Corrosion and Materials Degradation, 1 (1), 59-76. Botelho, G. R., & Mendonça-Hagler, L. C. (2006). Fluorescent Pseudomonads associated with the rhizosphere of crops: ...
    ... E. (2000). Influence of carbon source on nitrate removal of contaminated groundwater in a denitrifying submerged filter. Journal of hazardous materials, 80 (1-3), 69-80. Gordanić, V., Jovanović, D., & Ćirić, A. (2004). Geoecological radioactive risks in the area of Boranja gradiorite massif. Мин ...