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321 items
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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 ...... increase corrosion, the number of artificial methods that can be used decreases in the production fluid. Parameter C2 represents solid particles. With the rise of solid particles in the production fluid, the number of artificial methods that can be used is reduced. Parameter C3 represents GOR. With ...
... overlap with some of the artificial lift methods represents the best solution for a new well. Figure 4. Hierarchical structure of fuzzy composition. Energies 2020, 13, 1758 9 of 15 The goal of this synthesis is to give a solution of optimization model. For example, if A1 is medium, A2 is high, ...
... temperature, (B4) fluid density, (B5) viscosity, and (B6) well deviation; • Production operating problem parameters (C), which are: (C1) corrosion, (C2) solid particles, (C3) gas oil ratio—GOR, (C4) paraffin, and (C5) water cut. Figure 1 shows the conceptual model of an expert system for optimized selection ...Miroslav Crnogorac, Miloš Tanasijević, Dušan Danilović, Vesna Karović Maričić, Branko Leković. "Selection of Artificial Lift Methods: A Brief Review and New Model Based on Fuzzy Logic" in Energies, MDPI AG (2020)
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Structural dissymmetrization of optically anisotropic Grs64±1Adr36±1Sps2 grandite from Meka Presedla (Kopaonik Mt., Serbia)
In this paper, grandite core with Grs64±1Adr36±1Sps2composition was crystallographically studied. This core represents zone A of the macroscopically visiblefive A–E zones of the optically anisotropic Grs58–64 Adr36–42Sps2 grandite. The applied procedure includes the detailed analysis of the powder diffraction patterns, and the Rietveld refinements of the crystal structures in a series of 18 space groups and two mixtures, which were followed by the comparative analysis of the R-values, site occupancy factors, and the bond lengths and angles. Synthesis of all ...Pavle Tančić, Aleksandar Kremenović, Predrag Vulić. "Structural dissymmetrization of optically anisotropic Grs64±1Adr36±1Sps2 grandite from Meka Presedla (Kopaonik Mt., Serbia)" in Powder Diffraction, Cambridge University Press (CUP) (2019). https://doi.org/10.1017/S0885715619000897
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A WebGIS Decision Support System for Management of Abandoned Mines
Ranka Stanković, Nikola Vulović, Nikola Lilić, Ivan Obradović, Radule Tošović, Milica Pešić-Georgiadis (2016)... relations among data, as well as quality of user interface featuring easy and simple search and display od structured data. Development of the software solution was compliant with recommendations related to spatial data infrastructure (SDI), which implements a framework of geographic data, metadata, users ...
... facility, legal and working status, and type of ownership. Energies 2016, 9, 567 8 of 14 Appropriate formulas were implemented in the software solution and the related calculation varies from simple to complex. As an example, we present simple formulas for score mapping to the range 0–100 for q ...
... n using free and open source technology that enables connection to similarly configured data exchange networks. This approach offers a long-term solution for the storage and exchange of data without commercial software. USGIN makes available, connects and opens the data related to the earth sciences ...Ranka Stanković, Nikola Vulović, Nikola Lilić, Ivan Obradović, Radule Tošović, Milica Pešić-Georgiadis. "A WebGIS Decision Support System for Management of Abandoned Mines" in Energies 7 no. 9 (2016): 567. https://doi.org/10.3390/en9070567
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Numeričko modelovanje povećanja iskorišćenja naftnih ležišta injektiranjem polimera i analiza osetljivosti parametara
Jana Šujica (2024)U toku proizvodnje jednog ležišta, nakon primene sekundarnih metoda iskorišćenja, velika količina nafte ostaje zarobljena u ležištu. Ovaj “problem” rešava se upotrebom tercijarnih metoda iskorišćenja.Tercijarne metode mogu se podeliti na: hemijske, termičke, mikrobiološke i metode utiskivanja gasova u uslovima mešanja i nemešanja.U ovom radu analiziraju se hemijske metode koje se odnose na injektiranje polimera u cilju povećanja iskorišćenja naftnog ležišta “X”. Simulacija je rađena u simulatoru “Tnavigator” na sintetičkom modelu u cilju definisanja stepena iskorišćenja naftnog ležišta “X” nakon ...... RUNSPEC ... anaaaaaakaaaaaaeaaaaaaaaaaakaiaoe 28 KK IDA 54 10 VOAAAAAA AAAAAA RAAAAA 28 3.3.3. PROPS a anaaaaaaaaaaaaa e a aaaaaaakataoi 28 3.3.4. SOLUTION ... anaaaaaaa a aaaaaaaaaaaaakaaaoi 32 KE JI „ 451 010 JAAAAAA 32 3.4. Postupak “mečovanja” podataka ...........aaaaaaaa a aanaatakataNoe 33 ...
... unos ključnih reči koje definišu sekcije modela. Model se sastoji od 9 sekcija, definisanih ključnim rečima: RUNSPEC, GRID, EDIT, PROPS, REGIONS, SOLUTION, SUMMARY, RECU i SCHEDULE. 3.3.1. RUNSPEC sekcija sadrži sve osnovne podatke, koji su potrebni za definisanje modela kao što su: naziv modela ...
... 83 sloj 14 83,38 sloj 15 64,19 U modelu je definisan samo jedan PVT region, prikazan na slici 3.3.3.3. Slika 3.3.3.3. PVT region 3.3.4. SOLUTION sekcija definiše početne uslove koji vladaju u ležištu kao i početni rastvorljivi gasni faktor za svaki region modela. S obzirom da je ležište male ...Jana Šujica. Numeričko modelovanje povećanja iskorišćenja naftnih ležišta injektiranjem polimera i analiza osetljivosti parametara, 2024
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Keyword-Based Search on Bilingual Digital Libraries
This paper outlines the main features of Biblisha, a tool that offers various possibilities of enhancing queries submitted to large collections of aligned parallel text residing in bilingual digital library. Biblishsa supports keyword queries as an intuitive way of specifying information needs. The keyword queries initiated, in Serbian or English, can be expanded, both semantically, morphologically and in other language, using different supporting monolingual and bilingual resources. Terminological and lexical resources are of various types, such as wordnets, electronic ...Ranka Stanković, Cvetana Krstev, Duško Vitas, Nikola Vulović, Olivera Kitanović. "Keyword-Based Search on Bilingual Digital Libraries" in Semantic Keyword-Based Search on Structured Data Sources - Second COST Action IC1302 International KEYSTONE Conference, IKC 2016, Springer (2017). https://doi.org/10.1007/978-3-319-53640-8_10
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An aproach to Implementation of blended learning in a university setting
... Belgrade, as a complementary approach to traditional face-to-face instruction. The initial platform for this blended learning approach was an in-house solution which has been successfully used for several years. From the academic 2010/11 year the approach was further enhanced by a gradual introduction ...
... be classified under blended learning, gradually evolved. Namely, the initial blended learning platform was developed as an in-house software solution, but starting with the academic year 2010/11, the open-source Moodle (Modular Object-Oriented Dynamic Learning Environment) platform was also ...Ivan Obradović, Ranka Stanković, Olivera Kitanović, Jelena Prodanović . "An aproach to Implementation of blended learning in a university setting" in Proceedings of the Second International Conference on e-Learning, eLearning 2011, September 2011, Belgrade, Serbia, Belgrade : Belgrade Metropolitan University (2011)
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The Usage of Various Lexical Resources and Tools to Improve the Performance of Web Search Engines
In this paper we present how resources and tools developed within the Human Language Technology Group at the University of Belgrade can be used for tuning queries before submitting them to a web search engine. We argue that the selection of words chosen for a query, which are of paramount importance for the quality of results obtained by the query, can be substantially improved by using various lexical resources, such as morphological dictionaries and wordnets. These dictionaries enable semantic ...LR web services, MultiWord Expressions & Collocations, Information Extraction, Information Retrieval... Serbian are now expanded with the usage of some sort of a stemmer. However, this approach solves the inflection problem only partially and the solution is far from systematic. As is often the case with stemmers, Google expands the query by including not only (some) inflective forms but also ...
... Since the latter structure is not very frequent in Serbian, the former is chosen that is also the correct one. In this particular case the latter solution would not yield erroneous results either since for query expansion we need only correctly inflected forms and not grammatical categories. ...Krstev Cvetana, Stanković Ranka, Vitas Duško, Obradović Ivan. "The Usage of Various Lexical Resources and Tools to Improve the Performance of Web Search Engines" in LREC 2008: Conference on Language Resources and Evaluation, Marrakesh, Morocco, May 2008, European Language Resources Association (ELRA) (2008)
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The Newton method for solving nonlinear equations based on aggregation operators
Nebojša M. Ralević, Dejan Ćebić (2019)Nebojša M. Ralević, Dejan Ćebić. "The Newton method for solving nonlinear equations based on aggregation operators" in XLVI International Symposium on Operational Research SYM-OP-IS, Kladovo, 15-18.9.2019, Универзитет у Београду (2019)
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OntoLex Publication Made Easy: A Dataset of Verbal Aspectual Pairs for Bosnian, Croatian and Serbian
Ovaj rad predstavlja novi jezički resurs za pretraživanje i istraživanje verbalnih aspektnih parova u BCS (bosanskom, hrvatskom i srpskom), kreiran korišćenjem principa Lingvističkih Povezanih Otvorenih Podataka (LLOD). Pošto ne postoji resurs koji bi pomogao učenicima bosanskog, hrvatskog i srpskog kao stranih jezika da prepoznaju aspekt glagola ili njegove parove, kreirali smo novi resurs koji će korisnicima pružiti informacije o aspektu, kao i link ka aspektnim parovima glagola. Ovaj resurs takođe sadrži spoljne linkove ka monolingvalnim rečnicima, Wordnetu i BabelNetu. ...Ranka Stanković, Maxim Ionov, Medina Bajtarević, Lorena Ninčević. "OntoLex Publication Made Easy: A Dataset of Verbal Aspectual Pairs for Bosnian, Croatian and Serbian" in Proceedings of the 9th Workshop on Linked Data in Linguistics @ LREC-COLING 2024, Turin, 20-25 May 2024, ELRA and ICCL (2024)
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Debris-flow Susceptibility Assessment in Flow-R: Ribnica River Case Study
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 ...Ksenija Micić, Miloš Marjanović, Biljana Abolmasov . "Debris-flow Susceptibility Assessment in Flow-R: Ribnica River Case Study" in Proceeding of the 6th Regional Symposium on Landslides in the Adriatic-Balkan Region, ReSyLAB 2024, University of Belgrade, Faculty of Mining and Geology (2024). https://doi.org/https://doi.org/10.18485/resylab.2024.6
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Evaluation And Perspectives Of Underground Coal Mines In Serbia
... multi-criteria decision-making approach introduced by Saaty [4]. The AHP method enables users to determine the weights of the parameters in the solution of a multi-criteria problem. In the AHP method, a hierarchical model consisting of objectives, criteria, sub-criteria and alternatives is used for ...Vladimir Milisavljević, Milena Lekić, Ivica Ristović, Vojin Čokorilo, Aleksandar Cvjetić. "Evaluation And Perspectives Of Underground Coal Mines In Serbia" in 7th Balkan Mining Congress Preceedings - BalkanMine2017, Prijedor, 11-13. oktobar 2017., Banjaluka : University of Banjalika, Faculty of Mining, RS, BiH (2017)
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Improving efficiency of thermal power plants through mine coal quality planning and control
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 ...Mirjana Banković, Dejan Stevanović, Milica Pešić, Aleksandra Tomašević, Ljiljana Kolonja. "Improving efficiency of thermal power plants through mine coal quality planning and control" in Thermal Science, Vinča Institute of Nuclear Sciences (2018). https://doi.org/10.2298/TSCI170605209B
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Simulation of Hydrogeological Environmental Discharge in Case of Interruption Constant Observations
Marina Čokorilo Ilić, Dragoljub Bajić, Miroslav Popović. "Simulation of Hydrogeological Environmental Discharge in Case of Interruption Constant Observations" in International Scientific Conference - Sinteza 2024, Belgrade, 16. maj 2024, Singidunum University (2024). https://doi.org/10.15308/Sinteza-2024-288-294
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Trans-Lithospheric Diapirism as a Possible Mechanism for Ophiolite Emplacement?
Nikola Stanković, Taras Gerya, Vladica Cvetković, Vesna Cvetkov. "Trans-Lithospheric Diapirism as a Possible Mechanism for Ophiolite Emplacement?" in EGU General Assembly 2024, Vienna, 14-19 April 2024, Göttingen : Copernicus GmbH (2024). https://doi.org/10.5194/egusphere-egu24-568
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Application of a Method for Intelligent Multi-Criteria Analysis of the Environmental Impact of Tailing Ponds in Northern Kosovo and Metohija
Gordana Milentijević, Blagoje Nedeljković, Milena Lekić, Zoran Nikić, Ivica Ristović, Jelena Đokić (2016)... for these alternatives are given in Figure 3. Figure 4 shows a diamond PROMETHEE solution. This solution shows partial PROMETHEE I and final ranking PROMETHEE II in a two-dimensional model. The PROMETHEE diamond solution is presented with the dot on (Phi+,Phi−) flat. The flat is at an angle of 45◦ so ...
... through which comes discharge of atmospheric waters from the landfill directly into the Ibar. Deposed flotation tailing is in general oxidized and solid [1]. č č č č đ ć ć ć đ đ ć Figure 2. Tailing pond Gornje Polje (a)—not active; and tailing pond Bostanište (b)—active. Flotation tailing ...
... Drainage water from the landfill is collected and taken directly into the Ibar. Surface of the tailing is oxidized and red. On the sides of the dam, solid parts are noticeable. Due to the fact that raising the upper level of the dam is no longer possible since its construction stability is in danger, there ...Gordana Milentijević, Blagoje Nedeljković, Milena Lekić, Zoran Nikić, Ivica Ristović, Jelena Đokić. "Application of a Method for Intelligent Multi-Criteria Analysis of the Environmental Impact of Tailing Ponds in Northern Kosovo and Metohija" in Energies, MDPI AG (2016). https://doi.org/10.3390/en9110935
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The subthermal potential of karstic groundwater of Kučaj–Beljanica region in Serbia estimated by the multivariate analysis
Earth-Surface Processes, Geology, Pollution, Soil Science, Water Science and Technology, Environmental Chemistry, Global and Planetary ChangeLjiljana Vasić, Dragana Ž. Živojinovic, Vladana Rajaković-Ognjanović, Huang Fen, Cao Jianhua. "The subthermal potential of karstic groundwater of Kučaj–Beljanica region in Serbia estimated by the multivariate analysis" in Environmental Earth Sciences, Springer Science and Business Media LLC (2021). https://doi.org/10.1007/s12665-021-09392-1
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Surface functional groups and degree of carbonization of selected chars from different processes and feedstock
Marija Ilić, Franz-Hubert Haegel, Aleksandar Lolić, Zoran Nedić, Tomislav Tosti, Ivana Sredović Ignjatović, Andreas Linden, Nicolai D. Jablonowski, Heinrich Hartmann (2022)The knowledge ofthe structural and chemical properties of biochars is decisive for their application as technical products. For this reason, methods for the characterization of biochars that are generally applicable and allow quality control are highly desired. Several methods that have shown potential in other studies were used to investigate two activated carbons and seven biochars from different processes and feedstock. The chars were chosen to cover a wide range of chemical composition and structural properties as a hardness ...Biougalj, različiti procesi dobijanja, različite sirovine, površinski aktivne grupe, x-ray, FT-IR,XPS... of HCI-treated char was shaken with 25 ml of0.05 mol1! NaOH for 24 h to extract organic components of low molecular weight. The solid was separated from the solution by filtration using 0.45 um nitrocellulose fil- ters. The absorbance at 250 nm (A250) was measured as a qualitative index of dissolved ...
... outside the bronze electrodes was only filled with electrolyte and the filling height of the solid material was about 2.5 cm. The exact height was measured with a caliper rule. Since the surface of the solid mixture was not exactly flat in the rectangular sample holder, the accuracy of the cell constant ...
... The materials were filled into the sample holders in portions. Therefor, some electrolyte was first poured into the sample holders and then the solid materials were added so that a slight excess ofliquid remained. This mixture was stirred with a spatula in PLOS ONE | hitps://doi.org/10.1371/journal ...Marija Ilić, Franz-Hubert Haegel, Aleksandar Lolić, Zoran Nedić, Tomislav Tosti, Ivana Sredović Ignjatović, Andreas Linden, Nicolai D. Jablonowski, Heinrich Hartmann. "Surface functional groups and degree of carbonization of selected chars from different processes and feedstock" in PLOS ONE (2022). https://doi.org/10.1371/journal.pone.0277365
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EUROLAN 2021: Introduction to Linked Data for Linguistics Online Training School
Prva škola za obuku polaznika koju je organizovala COST akcija NexusLinguarum održana je od 8. do 12. februara 2021. godine sa ciljem da studenti, istraživači i stručnjaci nauče osnove lingvističke nauke o podacima. Tokom obuke polaznici su se upoznali sa širokim spektrom tema: od semantičkog veba, RDF -a i ontologija, do modeliranja i pretraživanja jezičkih podataka pomoću najsavremenijih ontoloških modela i alata. Škola je održana u okviru serije letnjih škola EUROLAN-a i organizovalo ju je virtuelno (onlajn) nekoliko instituta; ...nauka o lingvističkim podacima, povezani podaci u lingvistici, jezički podaci, EUROLAN, NexusLinguarum, COST akcija, škola za obuku... and Corpus Information - Ontology-Lexica Community Group 116 Infotheca Vol. 21, No. 1, September 2021 Professional paper a chance to acquire a solid foundation before moving onto more complex sessions. The official program of the school is available online.13 As a follow up, the JeRTeh14 Language ...
... the lecturers proposed an exercise and offered a step-by-step walk-through for the participants to understand the methodology leading towards the solution. They also intro- duced the basic technology needed. Then, during the exercise session, the participants were asked to work on a particular task like ...Milan Dojchinovski, Julia Bosque Gil, Jorge Gracia, Ranka Stanković. "EUROLAN 2021: Introduction to Linked Data for Linguistics Online Training School" in Infotheca, Faculty of Philology, University of Belgrade (2021). https://doi.org/10.18485/infotheca.2021.21.1.7
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Geotechnical Conditions for Construction of Savski Trg Metro Station as a Part of the Belgrade Metro Line One
In order to solve serious traffic congestion in Belgrade, a number of studies regarding the Belgrade Metro construction have been carried out since 1973. However, only in 2019, the routes of the future metro lines 1 and 2 were de-fined as a part of the General Metro Construction Project. The lines are de-signed to intersect at the location of Sava Square, where an interchange met-ro station will be built. It represents a complex geotechnical structure consist-ing of three different ...Nemanja Stanic, Dragoslav Rakic, Josip Isek, Slavoljub Simic. "Geotechnical Conditions for Construction of Savski Trg Metro Station as a Part of the Belgrade Metro Line One" in Lecture Notes in Civil Engineering, Springer Nature Singapore (2024). https://doi.org/10.1007/978-981-97-8221-5_11
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Overcoming the Low Oral Bioavailability of Deuterated Pyrazoloquinolinone Ligand DK-I-60-3 by Nanonization: A Knowledge-Based Approach
Jelena R. Mitrović , Branka Divović-Matović, Daniel E. Knutson, Jelena B. Ðoković, Aleksandar Kremenović, Vladimir D. Dobričić, Danijela V. Randjelović, Ivana Pantelić, James M. Cook, Miroslav M. Savić, Snežana D. Savić (2021)Poor water solubility of new chemical entities is considered as one of the main obstacles in drug development, as it usually leads to low bioavailability after administration. To overcome these problems, the selection of the appropriate formulation technology needs to be based on the physicochemical properties of the drug and introduced in the early stages of drug research. One example of the new potential drug substance with poor solubility is DK-I-60-3, deuterated pyrazoloquinolinone, designed for the treatment of various neuropsychiatric ...... plasma and supernatants by solid-phase extraction using Oasis HLB cartridges (Waters Corporation, Milford, MA, USA). The cartridges were pre- Pharmaceutics 2021, 13, 1188 6 of 19 conditioned by methanol and water and then loaded with samples and internal standard solution, while the endogenous impurities ...
... approach. Generally, poorly soluble substances can be characterized as brick dust or grease balls depending on the limiting factor for the solubility: solid-state or solvation process [3,5]. Brick dust substances are poorly soluble in an aqueous environment as well as in lipids and organic solvents, and ...
... curve (AUC) in plasma were similar in the fasted and fed state (p = 0.998 and 0.100 for Cmax and AUC, respectively, Student t-test). In investigated solid tissues, although average values of AUC seem to be different, even two times higher in the group of fed animals, statistically the differences were ...Jelena R. Mitrović , Branka Divović-Matović, Daniel E. Knutson, Jelena B. Ðoković, Aleksandar Kremenović, Vladimir D. Dobričić, Danijela V. Randjelović, Ivana Pantelić, James M. Cook, Miroslav M. Savić, Snežana D. Savić. "Overcoming the Low Oral Bioavailability of Deuterated Pyrazoloquinolinone Ligand DK-I-60-3 by Nanonization: A Knowledge-Based Approach" in Pharmaceutics, MDPI, Basel, Switzerland (2021). https://doi.org/10.3390/pharmaceutics13081188