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Упит dcterms_subject_txt:top-down method

509 items

  • Definition of Circulation Conditions and Groundwater Genesis of the Complex Krupaja Hydrogeological Karst System (Eastern Serbia)

    Ljiljana Vasić, Saša Milanović, Tina Dašić (2023)
    Management, Monitoring, Policy and Law,Renewable Energy, Sustainability and the Environment, Geography, Planning and Development, Building and Construction
    ... whose channels are predisposed by the NE-SW fault. The shallower channels go down to a depth of 20 m, and after 70 m, they exit into a dry siphon hall, while the deeper channel, according to the latest research, goes down to a depth of 123 m [7]. The quantity of water drained from this spring; ...
    ... tritium content was determined at all three locations. The T+He method was carried out only at the cold Krupaja Spring, with deep siphonal circulation, while the age of the Krupaja thermal spring was determined using the IMC method with age correction using the I5C /C contentin the rock and water ...
    ... i.e., the age of the water was calculated using, the ŽH/3He isotopic method (Table 3). According to the results, it was concluded that the groundwater age of the Krupaja Spring, is 26.1 years +/— 0.7 years. The ŠH/3He method gave the highest age of the young component in the groundwater sample that ...

  • 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

  • Parametri zbijanja komunalnog otpada određeni različitim laboratorijskim metodama

    Jovana M Janković Pantić, Dragoslav R Rakić, Irena G Basarić Ikodinović, Tina D Đurić, Snežana Bogdanović (2021)
    Zbijanje komunalnog otpada predstavlja jednu od osnovnih faza korišćenja komunalne deponije. Zbog toga je kao i kod drugih nasutih građevina, veoma korisno odrediti parametre zbijanja: maksimalnu suvu zapreminsku težinu (dmax) i optimalnu vlažnost (wopt). Dobijeni rezultati mogu da posluže prilikom projektovanja kapaciteta deponije kao i prilikom definisanja obradivosti otpada. U dosadašnjoj praksi najčešći način određivanja parametra zbijanja je standardna metoda (Proktorov opit) koja se koristi u mehanici tla, uz eventualnu redukciju energije zbijanja. Međutim, različiti tretmani komunalnog otpada na ...
    deponija komunalnog otpada, zbijanje, Proktorov opit, malj sa šiljcima
    ... capacity ог the landfill as well as when defining the workability of waste. In current practice, ће most common method ог determination compaction parameters is by standard method (Proctor compaction test) used јп soil mechanics, with еуепша! reduction of compaction епегру. Although this methodology ...

  • Geofizičko reflektivno sondiranje kao test integriteta betonskog šipa

    Jovo Jakišić (2024)
    Temelj predstavlja izuzetno bitan element svakog građevinskog objekta. Zbog toga je neophodno poštovati odgovarajuće standarde, u projektovanju i izvođenju temeljne konstrukcije.Šipovi predstavljaju jedan od načina dubokog fundiranja tj. temeljenja. Za svaki izvedeni šip pojedinačno neophodno je izvesti kontrolu kvaliteta. Postoji više postupaka kojima je mogućeizvršiti kontrolu kvaliteta, a jedan od njih je test integriteta šipa malom silom, koji je prikazan u ovom radu.Ovaj postupak se izvodi seizmometrijskom metodom, postupkom refleksije, koji je definisan međunarodnim standardom ASTM D5882.Podaci koji su prikazani ...
    temelj, šip, seizmometrijska metoda
    ... ASTM Standard su: - C 469 Test Method for Static Modulus of Elasticity and Poisson's Ratio of Concrete in Compression - D1I98 Methods of Static Tests of Timbers in Structural Sizes - D653 Terminology Relating to Soil, Rock, and Contained Fluids - D1II143 Method of Testing Piles Under Static Axial ...
    ... Axial Com- pressive Load - D4945 Test Method for High Strain Dynamic Testing of Piles Definicija izraza specifičnih za ovaj standard: - integritet šipova, n-kvalitativna procena fizičkih „dimezija, neprekidnost šipa i konzistencija materijala od kojeg je on napravljen. - impendasa šipa, ...
    ... Beograd Spasojević, A., 1994. Magistarski Rad: „Teorija ı primena propagacije naponskih talasa u ispitivanju šipova“ ASTM D5882-00 Standard Test Method for Low Strain Integritiy Testing of Piles PET User Manual. URL: www.piletest.com/products 22 IZJAVA Izjavljujem da sam samostalno izradio ...

  • Validation of vulnerability assessment by means of the Time Dependent, Model: case study from the Slovenian karst catchment

    Vladimir Živanović, Nataša Ravbar, Igor Jemcov (2019)
    Groundwater vulnerability assessment methods are continuously being developed and existing methods are very often modified to provide better simulation of natural protection conditions and more objective results. Most frequently used methods are based on calculation of predefined parameters influencing water infiltration and underground flow, which can often lead to bias conclusions related to vulnerability evaluations. Some other methods, like the Time Dependent Model (TDM) are based on an approach, where parametrization is obtained at the final stage of the ...
    Ocena ranjivosti podzemnih voda, karstne podzemne vode, TDM metoda, delineacija sanitarnih zona, Slovenački karst

  • Значај петрографске анализе флуидних инклузија

    Стефан Петровић, Милош Велојић (2022)
    У раду је истакнут значај петрографске анализе током истраживања флуидних инклузија и приказане могућности ове методе на примерима неких од карактеристичних петрографских појава из различитих минерала. Петрографска анализа је први корак у испитивању флуидних инклузија. Правилно спроведена, петрографска анализа омогућава одређивање генетске везе флуидних инклузија и минерала домаћина, препознавање карактеристика флуидних инклузија и релевантну интерпретацију података из наредних корака истраживања. Петрографском анализом се дефинишу: а) дистрибуција флуидних инклузија у минералу; б) облик, величина и фазни састав флуидних инклузија; в) групације ...
    петрографија, флуидне инклузије, флуиди, групације

  • 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
    ... Comparison of methods which can be used for choosing a recultivation solution Method Feature Advantage Disadvantage Partial ranking of the User-friendly outranking i ; method, completeness of Does not provide a clear method to actions, based on the : ; : . : : Promethee NH : ranking, partial and ...

  • Geotechnical conditions of “Debelo brdo” tunnel construction on the highway E-80: Nis-Merdare-Pristina (“Peace Highway”)

    Dragoslav Rakić, Irena Basarić Ikodinović, Radojica Lapčević, Dragan Lukić (2024)
    The construction of the highway E-80 has begun in Serbia, which will represent the traffic hub of the Western Balkans and will be part of the main regional transport network of Southeast Europe. Its total length through Serbia is 77 km, and one part of the route is designed through a typical plain terrain, while a larger part of the route passes through hilly terrain. The construction of the tunnel “Debelo brdo” is planned partly in an open cut ...
    „Debelo brdo“ tunnel, temporary slopes, open cut excavation, tunnel excavation, piles

  • Fuzzy Model for Risk Assessment of Machinery Failures

    Dejan V. Petrović, Miloš Tanasijević, Saša Stojadinović, Jelena Ivaz, Pavle Stojković (2020)
    The main goal of this research was the development of an algorithm for the implementation of negative risk parameters in a synthesis model for a risk level assessment for a specific machine used in the mining industry. Fuzzy sets and fuzzy logic theory, in combination with statistical methods, were applied to analyze the time picture state of the observed machine. Fuzzy logic is presented through fuzzy proposition and a fuzzy composition module. Using these tools, the symmetric position of the ...
    fazi teorija, rizik, otkaz rudarskih mašina
    ... defines the membership degree, that is, the membership function of the defined Symmetry 2020, 12, 525 10 of 26 fuzzy sets. The best-fit method (Least Squares Method) is the appropriate procedure to determine the membership function of specific fuzzy sets [33]: di(Ri, Hi) = [(Σ10 j=1(µjR − µjHi))]ˆ ...
    ... can lead to the same RPN value. [22,31]. The proposed method avoids this. The second advantage of the proposed model is in maximized objectivity (or avoidance of subjectivity) in proposition and composition. Fuzzy models which use AHP method (Analytic Hierarchy Process) in combination with fuzzy logic ...
    ... called risky events. In general, it can be said that an event that can influence the outcome of a defined objective (preventing, disabling, or slowing down the realization of a goal) can be considered a risky event. Managing, controlling, and monitoring the risk of mining machine failure is a highly complex ...

  • Using Lexical Resources for Irony and Sarcasm Classification

    Miljana Mladenović, Cvetana Krstev, Jelena Mitrović, Ranka Stanković (2017)
    The paper presents a language dependent model for classification of statements into ironic and non-ironic. The model uses various language resources: morphological dictionaries, sentiment lexicon, lexicon of markers and a WordNet based ontology. This approach uses various features: antonymous pairs obtained using the reasoning rules over the Serbian WordNet ontology (R), antonymous pairs in which one member has positive sentiment polarity (PPR), polarity of positive sentiment words (PSP), ordered sequence of sentiment tags (OSA), Part-of-Speech tags of words (POS) ...
    ... the best result (F1 = 80%) was achieved using the RF method over the corpus of #humor tweets, while authors in [6] used Support Vector Machine, Logistic Regression (LR), DT, RF and NB, and the best result (F1 = 74%) was achieved using the LR method with a combination of all sug- gested predictors. Pa ...
    ... expand the set of ontological rules to include procedures of generalization and specifications of con- cepts that are already included by the rules laid down by this system. Also, we should use more balanced datasets to achieve more reliable results. 6 CONCLUSIONS In this paper we have suggested and assessed ...
    ... positive polarity, if analysis and detection of the rhetorical figure irony had not been performed. In this paper, we suggest and assess an automatic method of detection of verbal irony using rules of ontological reasoning in the Serbian WordNet (SWN) ontology. In Section 2 we present how irony detection ...

  • Valorization of non-balanced coal reserves in Serbia for underground coal gasification

    David Petrović, Lazar Kričak, Milanka Negovanović, Stefan Milanović, Jovan Marković, Nikola Simić, Ljubisav Stamenić (2019)
    In the name of a better and safer energy future, it is our responsibility to focus our knowledge and activities to save on imported liquid and gas fossil fuels, as well as coal on which energy security of Serbia is based. The rationalization in the use of available energy resources certainly positively affects economy and the environment of a country. This paper indicates motivations for the application of the underground coal gasification process, as well as surface gasification for ...
    ugalj, gasifikacija, zaštita životne sredine, skladištenje, solarna
    ... additionally burn and accelerate the development of the firehead in the layer. The process of initiating the combustion of a gas generator basically comes down to the following: — usually a coke and a cartridge for ignition is introduced into the channel, which is intended for initiating the combustion ...
    ... combustion in TPP burners, nor sulfur oxides. Sulfur, which would possibly find itself near the gasificatiton zone, will remain bound in the form of down-forming sulfide compounds through the accompanying reactions in the UCG. To additionally support the environmentally friendly aspect of UCG in Serbia ...
    ... a coal gasification layer and consists of drilling vertical wells or boreholes that follow the coal layer. Pipes are placed into wells up to the top ofthe coal layer, and the contact of the pipe with the surrounding area is cemented, while borehole is not placed in the tube that is passing through ...

  • The Fuzzy–AHP Synthesis Model for Energy Security Assessment of the Serbian Natural Gas Sector

    Aleksandar R. Madžarević, Dejan D. Ivezić, Miloš L. Tanasijević, Marija A. Živković (2020)
    Natural gas is used for the production of almost 20% of total energy today. The natural gas security of the Republic of Serbia is an urgent strategic, political and security issue. Serbia is one of the most vulnerable countries in Southeast Europe, because it only has one supply route. This study is a contribution to efforts to better understand the factors affecting energy security through the implementation of a new methodology based on the fuzzy–AHP synthesis model for measuring ...
    energetska bezbednost, prirodni gas, fazi AHP, AHP višekriterijumska analiza, fazi teorija
    ... energy security. Some of the models for energy security assessment have originated from different scientific backgrounds. For example, the POLES-model, top-down economic model, operates with economic and demographic development as input parameters, to assess supply and demand of energy up until 2050 [35]. ...
    ... number of ranking methods in the literature. The analytic hierarchy process (AHP) method was used in this study. AHP is a mathematical method in multi-criteria decision-making (MCDM) that is most often used [60]. This method is characterized by the possibility to emphasize the influence of a partial indicator ...
    ... consistency index CR: CR = CI/RI (10) where: RI—empirical consistency index of the multi-criteria AHP method (for n = 3, RI = 0.58 [62]). The aforementioned ranking procedure using the AHP method was repeated for each partial indicator within each synthesis indicator. (IV) The fourth step in the formation ...

  • Model upravljanja investicionim projektima otvaranja površinskih kopova uglja

    Cvjetko P. Stojanović (2015-04-27)
    Brze promene u okruženju pred rukovodioce postavljaju mnogobrojne zahteve,pre svega, one koji se tiču ostvarenja ciljeva u zadatom vremenu i raspoloživimsredstvima što zahteva fleksibilan pristup u organizovanju aktivnosti i efikasnost unjihovom sprovođenju.Upravljanje projektima, bilo koje vrste, suštinski, predstavlja veoma složenproces odlučivanja uslovljen velikim brojem ulaznih faktora. Ti faktori treba daomoguće fokusiranje na prioritete i ciljeve, praćenje realizacije, fleksibilnost uprevazilaženju teškoća, prilagođavanje promenama, te kontrolu nad ostvarenimrezultatima. Ovakav način upravljanja zahteva korišćenje proverenih tehnika i alata tetimski rad angažovanih na ...
    Projekat, upravljanje, metodologija, površinska eksploatacija, model

  • Model upravljanja investicionim projektima otvaranja površinskih kopova uglja

    Cvjetko P. Stojanović (2015-04-27)
    Brze promene u okruženju pred rukovodioce postavljaju mnogobrojne zahteve,pre svega, one koji se tiču ostvarenja ciljeva u zadatom vremenu i raspoloživimsredstvima što zahteva fleksibilan pristup u organizovanju aktivnosti i efikasnost unjihovom sprovođenju.Upravljanje projektima, bilo koje vrste, suštinski, predstavlja veoma složenproces odlučivanja uslovljen velikim brojem ulaznih faktora. Ti faktori treba daomoguće fokusiranje na prioritete i ciljeve, praćenje realizacije, fleksibilnost uprevazilaženju teškoća, prilagođavanje promenama, te kontrolu nad ostvarenimrezultatima. Ovakav način upravljanja zahteva korišćenje proverenih tehnika i alata tetimski rad angažovanih na ...
    Projekat, upravljanje, metodologija, površinska eksploatacija, model

  • Razvoj modela upravljanja cirkulacijom u postupku bušenja korišćenjem neuro fazi sistema zaključivanja

    Seyed Ali S. Razeghi (2022)
    Gubitak isplake predstavlja nekontrolisano isticanje bušaćeg fluida kroz formacije kao što su kaverne, pukotine, ili drugi slojevi. Tradicionalne metode procene gubitka isplake se zasnivaju na primeni seizmičkih podataka ili pronalasku „mesta“ gubitka isplake na osnovu raspoloživih podataka iz susednih bušotina. Međutim, ove metode procene nisu pouzdane.‘ U disertaciji je izvršena analiza i procena uticaja parametara bušenja, geoloških faktora, karakteristika formacije i fluida na gubitak isplake kao i na formiranje fraktura u formacijama. Uspostavljeni su modeli koji podrazumevaju proces obrade ...
    naftna bušotina, gubitak isplake, fuzzy logika, ANFIS model

  • Improvement of geodatabase queries within GeolISS

    Ranka Stanković (2008)
    ... which are represented in a GIS by digital data. There are two general approaches used for storing data in a GIS: the raster and the vector method. The first method represents geological features as images, whereas the latter uses geometrical shapes, namely different types of geometrical objects, for ...
    ... (part of ESRI ArcGIS), with a list of selected layers of spatial data on the left-hand side and the corresponding map on the right-hand side. In the top part of the snapshot is the GeolISS toolbar that enables the selection of appropriate data management tools. The user can select one or more objects ...
    ... related attributes. Modern GIS technologies are based on digital information, with various methods used for creating digital data. The most common method of data creation is digitization, where a hard copy map or research plan is transferred to digital form by means of a computer-aided design program ...

  • Application of Expansive Mortars for the Formation of Artificial Screens During Blasting in Urban Areas

    Milanka Negovanović, Lazar Kričak, Stefan Milanović, Nikola Simić, Jelena Majstorović (2024)
    During construction of buildings in urban areas, sometimes there is a need to blast solid rock mass in the immediate vicinity of the surrounding buildings. In that case, the aim is not only to increase the efficiency of blasting, but also to reduce harmful effects of ground vibration induced by blasting. At the same time, it is very important to protect the buildings located in the safe zone from the blast site as well as remaining rock mass around ...
    expansive mortar, artificial screens, pressure, rock breaking, building foundation

  • Refinement of waste phosphogypsum from Prahovo, Serbia: characterization and assessment of application in civil engineering

    Josip Išek, Lazar Kaluđerović, Nikola Vuković, Maja Milošević, Ivana Vukašinović, Zorica Tomić (2020)
    γ-spectrometry, brushite, chukhrovite, phosphogypsum, radionuclides, recrystallization
    ... Th are transferred into the phos- phoric acid. Through these chemical processes, the secular equi- librium between the specific decay series breaks down. The main objective of this study was to extract and character- 23; ize purified gypsum, as well as phosphogypsum. A secondary ol radionuclide ...
    ... of the samples' containers, and the purified gypsum sample was measured once, after the con- tainer was sealed. By applying the y-spectrometry method, the activity concen- tration of _ŠU was determined from its decay products Th (63keV) and/or "Pa (1000 keV). The ecay products of ? Ra, _ Bi (609 ...
    ... similar result was obtained with calcium sulfate whiskers synthesized from flue gas desulfurization of gypsum using the atmospheric acidification method (Sun ef al., 2016). Whiteness index The WI of 52.5%, determined for raw phosphogypsum (PG1), is too low for potential use in some industries ...

  • Some models for determination of parameters of the soil oscillation law during blasting operations

    Suzana Lutovac, Dragan Medenica, Branko Gluščević, Rade Tokalić, Čedomir Beljić (2018)
    ... specific work environment and by particular blasting conditions. 2.2.1. Model 1—Determining the Parameters by Applying the Least Square Method The least square method is mainly used to obtain the parameters K and n representing a common model [5,6]. 2.2.2. Model 2—Determining the Parameters by Applying ...
    ... determination of parameters K and n in the Sadovskii equation. To determine the parameters in the Sadovskii formula, in addition to the usual least square method, two more new models were applied. In the models the parameters K and n were determined by applying the quotient of the relative growth of oscillation ...
    ... friction, φ = 52˝; ‚ porosity, p = 3.5%; ‚ velocity of longitudinal waves, cp = 2400.00 m/s; ‚ velocity of transverse waves, cs = 1400.00 m/s. 4.1.2. Method of Blasting in the Veliki Krivelj Open Pit The measurements of shocks resulting from blasting in the Veliki Krivelj Open Pit were performed during ...

  • Sinteza i karakterizacija nanoprahova u CeO2-Bi2O3 sistemu

    Marija D. Prekajski (2014-04-04)
    Nanoprahovi kristalnih faza iz serije čvrstih rastvora u pseudo-binarnom sistemuCeO2-Bi2O3 sintetisani su primenom jednostavne i ekonomične samopropagirajućemetode na sobnoj temperaturi korišćenjem nitrata metala i natrijum-hidroksida kaopolaznih supstanci. Osim krajnjih članova niza, CeO2 i niskotemperaturne polimorfnemodifikacije α-Bi2O3, sintetisani su i čvrsti rastvori nominalnog sastava Ce1-xBixO2-δ,gde je x = 0,1; 0,2; 0,3; 0,4; 0,5; 0,6; 0,7; 0,8; 0,9. Rezultati proučavanja metodomrendgenske difraktometrije na polikristalnom materijalu i ramanske spektroskopskeanalize pokazali su da su sintetisani prahovi sa nižim sadržajem bizmuta (x = 0,1 ...
    nanostrukturni materijali, čvrsti rastvori, CeO2, Bi2O3, rendgenskadifraktometrija praha, Ritveldova metoda, mikrostrukrurna analiza