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Упит dcterms_subject_txt:limit ratio

226 items

  • 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
    ... since 2011. After more than 20 years of planning, Serbia is in the position to solve the problem of uneven consumption (winter/ summer consumption ratio is approximately 4:1). Also, the benefits of using storage are related to the improvement of security of supply (storage can provide approximately 20% ...

  • Debris-flow Susceptibility Assessment in Flow-R: Ribnica River Case Study

    Ksenija Micić, Miloš Marjanović, Biljana Abolmasov (2024)
    Debris flows are among the most dangerous erosional geohazards due to the fast rate of movement and long runout zones. Even though the initiation can be triggered in mountainous areas, inhabited and with steep slopes, their propagation and deposition can endanger not only buildings and infrastructure in the urbanized areas, but also threaten human lives. As these initiation areas usually represent unattainable terrains with rapid vegetation cover development, field observations and aerial photo analysis become high-demanding tasks. Consequently, medium-to-regional ...
    tečenje drobine, Flow-R, procena podložnosti, empirijski model

  • A necessary and sufficient condition for an algebraic integer to be a Salem number

    Dragan Stankov (2019)
    We present a necessary and sufficient condition for a root greater than unity of a monic reciprocal polynomial of an even degree at least four, with integer coefficients, to be a Salem number. This condition requires that the minimal polynomial of some power of the algebraic integer has a linear coefficient that is relatively large. We also determine the probability that an arbitrary power of a Salem number, of certain small degrees, satisfies this condition.
    Algebraic integer, the house of algebraic integer, maximal modulus, reciprocal polynomial, primitive polynomial, Schinzel-Zassenhaus conjecture, Mahler measure, method of least squares, cyclotomic polynomials
    ... probability for d = 8, 10. Theorem 1.2. Let τ be a Salem number of degree d, n, n0 ∈ N and let Pn(x) be the minimal polynomial of τn. Let pd denotes the limit of the probability that coefficients of Pn(x) satisfy (1.2) when n ≥ n0 is randomly chosen, as n0 approaches infinity. Then: (1) p4 is equal to 1/3 ...
    ... D − 1 . When n0 tends to infinity we obtain −1 < s1 < 1 i.e. −1/2 < cos θ1 < 1/2. It follows that π/3 < θ1 < 2π/3 or 4π/3 < θ1 < 5π/3 so that the limit of the probability has to be p4 = 2π/3 2π = 1 3 . 222 Dragan Stankov (2). Using (2.1) with d = 6 and the definition of D we have Pn(x) = (x2 ...
    ... t1Ot2 plane such that for every point (s1, s2) ∈ S there is unique (t1, t2) ∈ T where (2.11) t1 = arccos(s1/2), t2 = arccos(s2/2), using (2.8). The ratio of the area of T to the area of all possible values (t1, t2), i.e. π2, is equal to the probability p6. Since s2 = Fi(s1) it follows that t2 = arccos(Fi(2 ...

  • Detecting the boundaries of gravity anomaly sources using the vertical and tilt derivative

    Snežana Ignjatović, Ivana Vasiljević, Branislav Sretković ( 2024 )
    In geophysical exploration, it is important to define the boundaries of anomaly sources that are not visible on the surface. Information about the boundaries of sources can help during geophysical geological modeling of the survey area. A model of the survey area can help in better defining the geological structure and geological development of an exploration area. This paper presents how the procedures of vertical and tilt derivative on gravity data can help to detect the ...
    gravitacioni podaci, granica, sliv Žagubice

  • A multi-criteria approach for assessing the potential of renewable energy sources for electricity generation: Case Serbia

    Boban Pavlović, Dejan Ivezić, Marija Živković (2021)
    When assessing the potential of renewable energy alternatives for electricity generation, it is necessary to implement a multi-perspective approach that includes economic, technical, environmental, and socio-political criteria. For the evaluation of criteria and alternatives, the Fuzzy Analytical Hierarchy Process (FAHP) method is applied. The obtained weights are formed according to the values of energy indicators and expert judgments. The use of a fuzzy numerical value scale for the assessment of expert judgments and energy indicators provides a more sensitive ...
    Proizvodnja električne energije, Obnovljivi izvori energije, Višekriterijumsko odlučivanje, Srbija

  • Multihazard Exposure Assessment on the Valjevo City Road Network

    Miloš Marjanović, Biljana Abolmasov, Svetozar Milenković, Uroš Đurić, Jelka Krušić, Mileva Samardžić Petrović (2019)
    Prirodni hazardi, izloženost, klizišta, poplave, bujice, GIS, R
    ... scale of influ- ence. It is inversely symmetric (aij 5 aji 5 1) in respect to the main matrix diagonal. For the final AHP model, the CR (consistency ratio) was also calculated (Saaty & Vargas, 2001). The consistency index, CI, is calculated as: CI5 λmax � nð Þ n2 1ð Þ (31-3) where λmax is the principal ...
    ... principal eigenvalue, value of the judgment matrix. This CI can be com- pared with that of a random matrix RI with equation: CR5 CI RI (31-4) The ratio derived, CI/RI, is termed the CR. Saaty and Vargas (2001) suggest the value of CR should be less than 0.1. This depicts whether the interdependences ...

  • Method validation and geochemical modelling of chromium speciation in natural waters

    Piotr Rusiniak, Katarzyna Wątor, Ewa Kmiecik, Vesna Ristić Vakanjac (2024)
    The study focuses on validating reference methods such as ICP-OES and ICP-MS for detecting ultratrace levels of chromium in groundwater, where concentrations are typically very low. Additionally, it verifies a hyphenated technique, IC-ICP-MS, for determining naturally occurring Cr(VI) in tested waters. The validation process involved various chromium analysis variants, including isotopes 52Cr and 53Cr in ICP-MS and IC-ICP-MS techniques, along with specific emission lines in the ICPOES technique. Statistical data processing revealed that the achieved limits of quantification for ...
    шестовалентни хром, ИЦ-ИЦП-МС, технике са цртицама, геохемијско моделирање, анализа спецификација, валидација методе

  • Analiza softvera za projektovanje ESP sistema

    Aleksandar Sredojević (2024)
    U momentu kada pritisak na dnu bušotine nije dovoljan da savlada ukupne gubitke pritisaka od dna bušotine do separatora, proizvodnja pomoću ležišne energije nije više moguća i bušotina prestaje sa eruptivnim radom. Kako bi ponovo omogućili proizvodnju fluida iz bušotine, potrebno je primeniti neke od mehaničkih metoda eksploatacije. Najprimenljivije mehaničke metode eksploatacije su: gas lift (GL), dubinske pumpe sa klipnim šipkama (SRP), električne uronjene centrifugalne pumpe (ESP), zavojne pumpe (PCP) i hidraulične pumpe (HP). Jadna od tih metoda koja ...
    električna centrifugalna pumpa (ESP), proizvodnja fluida, mehaničke metode eksploatacije, Prosper, Pipesim
    ... zasnovane na terenskim podacima obično su ograničene na male ı srednje protoke nafte, ali obuhvataju širok opseg odnosa gas/tečnost (GLR-Gas Liquid Ratio), ova dva parametra su najvažnija u primeni krivi gradijenta (Michael G., Curtis H., W., 1991). Istorijski, razvoj ovih inženjerskih alata započeo ...
    ... statički pritisak na dnu, Hronologija merenja (vreme, dubine merenja, vrednosti), Temperatura na dnu bušotine, Željena proizvodnja, GLR-gas-liquid ratio (odnos gasa i fluida), Procenat vode. Osobine bušotinskog fluida Specifična težina vode, API nafte ili specifična težina, Specifična težina ...
    ... e AII correlations require hydrocarbon liquids at stock tank conditions except Mechanistic and API-14B Bean size: 46 mm - Critical pressure ratio: (e•) Specify ) Calculate 0.53 Tolerance: 0.5 % ~ Upstream pipe ID: mm d Slika 6–15: Prikaz prozora za unos površinske dizne |+ Data comparison ...

  • 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
    ... iCAP 6500 Duo ICP-OES spectrometer (Thermo Fisher Scientific, UK) equipped with a RACID86 charge injector device (CID) detector. The detection limit for the elements analysed was ~0.1 mg L . The digestion was performed in an Advanced Microwave Digestion System (ETHOS 1, Milestone, Italy) using ...
    ... Racq = Caa + 143 · Cm + 0.077 · k (1) where Cga, Crh and Ćk are the activity concentrations of ? “Ra, 5Th and “K in Bq kg", respectively. The limit for Ra,q is 370 Bq kg !, set by the report of the Organisation for Economic Co-operation and Development (OECD, 1979). To assess the radiological ...
    ... BDL 0.15 BDL Total 100.00” 100.00 100.00 100.00 “Calculated by stoichiometry. PQuantitative results normalized to 100%. BDL = below detection limit. Table 3. Chemical compositions of the samples investigated, obtained by ICP-OES analysis. Elements Units PG1 PG1P Na ppm 94.54 14.52 Mg ppm ...

  • Improving efficiency of thermal power plants through mine coal quality planning and control

    Mirjana Banković, Dejan Stevanović, Milica Pešić, Aleksandra Tomašević, Ljiljana Kolonja (2018)
    Главни циљ контроле квалитета угља у рудницима лигнита је снабдевање термоелектрана угљем чији квалитет мора да се креће унутар одређених квалитативних ограничења. Карактеристике угља могу да утичу на ефикасност, поузданост и расположивост како котла тако и јединица за контролу емисије. У овом раду аутори су презентовали интегрисану симулацију рударског процеса као нови приступ у истраживању променљивости калоричне вредности угља приликом експлоатације комплексног лежишта лигнита. Резултати таквог приступа омогућавају драгоцен увид у перформансе континуалног рударског система у смислу контроле променљивости ...
    mine planning, variability of coal quality, simulation, coal blending
    ... induced-draft fans. Pyrite causes excessive wear of the pulverize internals. Ash, sulphur and moisture directly affect the heating value of the coal and limit the capacity of the combustion system. The SO2 emission reduction is usually achieved either with the installation of flue gas desulphurization systems ...
    ... out as follows: (6) finish if the height of the region does not exceed two minimal sub-bench height; (7) the minimal number of sub-benches, M, is ratio of the total height of the region and sub-benches maximum height, considering the first and the last sub-bench constraints; (8) the maximum number ...

  • NMR kinetic studies of the interactions between [Ru(terpy)(bipy)(H2O)]2+ and some sulfur-donor ligands

    Aleksandar Mijatović, Biljana Šmit, Ana Rilak, Biljana Petrović, Dragan Čanović, Živadin D. Bugarčić (2012)
    Reakcije supstitucije monofunkcionalnog [Ru(terpi)(bipi)(H2O)]2+ kompleksa, gde je terpi = 2,2′:6′,2″-terpiridin i bipi = 2,2′-bipiridin, sa biološki relevantnim sumporo donorskim ligandima, kao što su tiourea, l-metionin, l-cistein i glutation, proučavane su u vodenim rastvorima tehnikom 1H i 13C NMR spektroskopije. Sve reakcije su proučavajne na pH 7,4, u prisustvu fosfatnog pufera, da bi se oponašalo fiziološko okruženje tokom procesa supstitucije. Reakcije se izvode na 295 K pod uslovima reakcija drugog reda. Uočeni rezultati pokazuju da brzina supstitucije snažno zavisi ...
    Materials Chemistry,Inorganic Chemistry,Physical and Theoretical Chemistry
    ... [Ru(terpy)(bipy)(H2O] 2+ complex with L-Met, L-Cys, GSH and thiourea were studied by 1H NMR spectros- copy. First, these reactions are followed in a 1:1 M ratio in D2O at Fig. 3. The changes of chemical shifts of Hd proton of terpyridine as a function of pD for the [Ru(terpy)(bipy)(H2O)] 2+ complex at 295 ...

  • Structural and geochronological constraints from the Drina-Ivanjica thrust sheet (Western Serbia): implications for the Cretaceous–Paleogene tectonics of the Internal Dinarides

    Kristof Porkoláb, Szilvia Kövér, Zsolt Benkó, Gabor Héja, Melinda Fialowski, Balázs Soós, Nataša Gerzina Spajić, Nevenka Đerić, László Fodor (2019)
    Internal Dinarides, Drina-Ivanjica thrust sheet, Deformation history, K–Ar dating, Obduction, Structural analysis
    ... and N-S). The age of D, strike-slip movements has a possible upper limit, since Miocene formations seem to seal Dx strike-slip faults (Fig.2a), however satisfying evidences are lacking. Direct evidence for the lower limit is lacking due to the absence of Paleogene rocks in the study area ...
    ... area. However we speculate using an indirect argument for the lower limit on the basis of regional forcing factors. It has been shown that indentation tectonics and related shortening in the Alps resulted in lateral wrenching in the Dinarides and the development of NW-SE striking dextral systems ...
    ... vacuum system by St-700 and Ti-getters. The isotopic composition of the spiked Ar was measured by a Nier-type mass spectrometer. The atmospheric Ar ratio was analyzed cach day during the measurement period and averaged 295.6 + 1.85 (1o) for 60 independent determi- nations. All isotope measurements ...

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

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

  • Mechanosynthesis and structural characterization of nanocrystalline Ce1–Y O2– (x=0.1–0.35) solid solutions

    Martin Fabián, Bratislav Antić, Vladimír Girman, Milica Vučinić-Vasić, Aleksandar Kremenović, Shigeru Suzuki, Horst Hahn, Vladimír Šepelák (2015)
    A series of nanostructuredfluorite-type Ce1–xYxO2–δ (0rxr0.35) solid solutions, prepared via highenergy milling of the CeO2/Y2O3mixtures, are investigated by XRD, HR-TEM, EDS and Raman spectroscopy. For thefirst time, complementary information on both the long-range and short-range structural features of mechanosynthesized Ce1–xYxO2–δ, obtained by Rietveld analysis of XRD data and Raman spectroscopy, is provided. The lattice parameters of the as-prepared solid solutions decrease with increasing yttrium content. Rietveld refinements of the XRD data reveal increase in microstrains in the host ceria ...
    Ceria, Yttrium, Solid solution, Mechanosynthesis, Oxygen vacancy, Nanocrystalline material

  • 2D geoelectrical resistivity tomography application at the former city waste dump "Ada Huja": Eco-geological problem

    Branislav Sretenović, Filip Arnaut, Ivana Vasiljević, Vesna Cvetkov (2019)
    2D inversion, geoelectrical method, Wenner array, ecology, Ada Huja

  • Serbian NER&Beyond: The Archaic and the Modern Intertwinned

    Branislava Šandrih Todorović, Cvetana Krstev, Ranka Stanković, Milica Ikonić Nešić (2021)
    U ovom radu predstavljamo srpski književni korpus koji se razvija pod okriljem COST Akcije „Distant Reading for European Literary History” CA16204. Koristeći ovaj korpus romana napisanih pre više od jednog veka, razvili smo i učinili javno dostupnim Sistem za prepoznavanje imenovanih entiteta (NER) obučen da prepozna 7 različitih tipova imenovanih entiteta, sa konvolucionom neuronskom mrežom (CNN), koja ima F1 rezultat od ≈91% na test skupu podataka. Ovaj model je dalje ocenjen na posebnom skupu podataka za evaluaciju. Završavamo poređenje ...

  • Development and Evaluation of Three Named Entity Recognition Systems for Serbian - The Case of Personal Names

    Branislava Šandrih, Cvetana Krstev, Ranka Stanković (2019)
    In this paper we present a rule- and lexicon-based system for the recognition of Named Entities (NE) in Serbian news paper texts that was used to prepare a gold standard annotated with personal names. It was further used to prepare training sets for four different levels of annota tion, which were further used to train two Named Entity Recognition (NER) sys tems: Stanford and spaCy. All obtained models, together with a rule- and lexicon based system were evaluated on ...
    NER, Named Entity Recognition Systems, Serbian, Personal Names

  • Arsenic in Tap Water of Serbia´s South Pannonian Basin and Arsenic Risk Assessment

    Petar Papić, Marina Ćuk, Maja Todorović, Jana Stojković, Bojan Hajdin, Nebojša Atanacković, Dušan Polomčić (2012)
    kvalitet podzemnih voda, arsen, analiza rizika, Panonski Basen

  • Back-arc underplating provided crustal accretion affecting topography and sedimentation in the Adria microplate

    Paolo Mancinelli, Vittorio Scisciani, Cristina Pauselli, Gérard M. Stampfli, Fabio Speranza, Ivana Vasiljević (2021)
    Supported by evidence of deep crustal sources for the observed magnetic anomalies in Central Italy and by outcropping gabbros in the Croatian archipelago, we model the observed gravity and magnetic anomalies in the Central Adriatic Sea and surroundings. We suggest that the major magnetic anomalies in the area are related to a wide underplating and propose that this volume represents the first stage of the back-arc Adria continental breakup in Early Permian times. During the Palaeotethys-Adria collision, underplating has ...
    Underplating, akrecija kore, Magnetske anomalije, Jadranska ploča
    ... back-arc area are still questioned. Traditionally, the distinctive features of magmatic underplating are high seismic P- and S- wave velocities and high ratio of P- to S-wave velocities of the intruded volume compared to surrounding crust (Thybo and Artemieva, 2013). More general, the products and crustal ...
    ... Areas bounded by white dashed lines locate the volumes considered for estimation of the volume of the magnetic sources. Vertical-to-horizontal scale ratio across the modeled sections is 0.5. Reference starting values for the Moho depth across the modeled area are from literature (Scarascia et al., 1998; ...

  • A new species and genus of Lower Jurassic rhynchonellide (Brachiopoda) from Livari (Rumija Mountain, Montenegro): taxonomic implications of the shell microstructure

    Barbara V. Radulović, Michael R. Sandy, Peter Schaaf (2024)
    brachiopods, liassic, skadarirhynchia, prionorhynchia, cuneirhynchia, Dinaric carbonate platform