Претрага
155 items
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Uniaxial compressive strength test before and after standard fire test on rock mass
Stefan Mitrović, Goran Todorović, Bojan Kostić, Milica Mirković-Marjanović, Nikola Božović, Marija Krstić, Aleksandar Erić, Radovan Gospavić, Snežana Ilić, Aleksandar Kijanović (2022)... AB HS TL V.C.", thermal power 296 kW manufactured by ECO FLAM. Two differential pressure transmitters type 6321 manufactured by TESTO (Germany), with a range of ± 100 Pa, inside furnace, were used to measure pressure. Inside furnace, temperature was measured in six places with a type K thermocouple ...
... different sizes, from 0.05 to 0.5 mm. The grains are mostly sub-rounded and partly un-rounded. Some have undulatory extincion due to the effect of pressure, which tells us that they are at least partly of metamorphic origin. The different size of this mineral, poorly sorted indicates a relatively short ...
... sample. After drying, and before testing, samples are stored at room temperature. Load on test specimen must be applied continuously, at a constant pressure increase of 1 ± 0,5 MPa/s. Maximum load must be accurately recorded. In Figure 2 samples prepared for uniaxial compressive strength test according ...Stefan Mitrović, Goran Todorović, Bojan Kostić, Milica Mirković-Marjanović, Nikola Božović, Marija Krstić, Aleksandar Erić, Radovan Gospavić, Snežana Ilić, Aleksandar Kijanović. "Uniaxial compressive strength test before and after standard fire test on rock mass" in Fifth symposium of the Macedonian Association for Geotechnics, Ohrid, North Macedonia, 23-25. 06. 2022, Macedonian Association for Geotechnics (2022)
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Mine ventilation system planning using genetic algorithms
The most common problem in contemporary mining practice related to the planning and analysis of ventilation systems is the optimization of partially regulated air distribution in mine ventilation networks. This paper presents a two step optimization procedure for partly regulated air distribution in mine ventilation networks. The first step is the determination of air distribution in all branches using the well known Hardy-Cross method. In the second step the distribution and parameters of air flow regulators with minimum engaged ...coal, lignite, and peat; ventilation systems; coal mining; underground mining; ventilation; mathematical models; design; air flow; optimization; calculation methodsNikola Lilić, Ranka Stanković, Ivan Obradović. "Mine ventilation system planning using genetic algorithms" in 6. international symposium on mine planning and equipment selection, Ostrava (Czech Republic), 3-6 Sep 1997, A.A. Balkema, Rotterdam (Netherlands) (1997)
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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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Hidraulički tranzijenti u karstnoj sredini tokom rada hidroelektrane
Maja Todorović, Marina Ćuk Đurović, Igor Jemcov. "Hidraulički tranzijenti u karstnoj sredini tokom rada hidroelektrane" in Knjiga apstrakata 10. Simpozijuma o zaštiti karsta, Zlatibor, 14-15. oktobar 2023., Beograd : Akademski speleološko–alpinistički klub (ASAK) (2023)
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Numerical modeling of Selanac debris flow propagation using SPH code
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 ...... either water or mud. If the shear resistance of the fluid phase can be neglected, the stress tensor in the mixture can be decomposed into a ‘pore pressure’ and an effective stress, and the mechanical behavior of the mixture can be described by a system of differential equations governing the dynamics ...
... and while mass is presented with particles of solid and fluid phase. Each particle has information about height, velocity as well as pore water pressure if coupled model is included. Geoflow SPH proposed by Pastor 2009, already has been used on different cases in the world (Pastor et al. 2015, 2009 ...
... depth averaged Biot-Zienkiewicz equations (Zienkiewicz and Schiomi, 1984) and it can be used with a variety of rheological laws and pore water pressure treatments. Two different meshes will be used, one to describe the terrain topography while the other consist of SPH nodes. Detailed discretization ...Jelka Krušić, Biljana Abolmasov, Miloš Marjanović, Manuel Pastor, Saeid M. Tayyebi . "Numerical modeling of Selanac debris flow propagation using SPH code" in SCG-XIII International Symposium on Landslides. Cartagena, Colombia- February 22-26, 2021, International Society for Soil Mechanics And Geotechnical Engineering (2021)
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Determination of Mechanical Properties of Altered Dacite by Laboratory Methods
This paper presents a methodology for determining the uniaxial and triaxial compressive strength of heterogeneous material composed of dacite (D) and altered dacite (AD). A zone of gradual transition from altered dacite to dacite was observed in the rock mass. The mechanical properties of the rock material in that zone were determined by laboratory tests of composite samples that consisted of rock material discs. However, the functional dependence on the strength parameter alteration of the rock material (UCS, intact ...... given by Hoek and Brown [20], where the values for the range of confining pressure are 0< σ3 < 0.5σci. During the test, the specimen first led to the hydrostatic stress state, i.e., with the increase in the confining pressure, the axial load of the sample increased in parallel until the hydrostatic state ...
... confining pressure. During the test, the axial loads of the sample to achieve the hydrostatic state were: 11.5; 22.9; 34.4; 45.8; 68.7 kN. After reaching the hydrostatic state, a further increase in the axial load was outstretched until the failure while maintaining a constant confining pressure. The equipment ...
... of the altered dacite to the mapped upper part of the dacite. Minerals 2021, 11, 813 3 of 19 Figure 1. Lithological column of the exploration borehole. Test samples D and AD undoubtedly show the same structural-textural character- istics, as well as the mineral composition. Only the intensities ...Veljko Rupar, Vladimir Čebašek, Vladimir Milisavljević, Dejan Stevanović, Nikola Živanović. "Determination of Mechanical Properties of Altered Dacite by Laboratory Methods" in Minerals, MDPI AG (2021). https://doi.org/10.3390/min11080813
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Analysis Of the Process Of Carbon Capture Utilization And Storage In Underground Reservoirs
John Nyame (2024)The importance of mitigating the effects of global climate change has necessitated an in-depth exploration of innovative strategies to reduce carbon dioxide (CO2) emissions. Among these strategies, Carbon Capture, Utilization, and Storage (CCUS) has emerged as a promising and transformative solution. This master thesis delves into the diverse realm of CCUS processes, aiming to unravel the positives challenges, and opportunities within this dynamic field. The analysis begins with a systematic examination of carbon capture technologies, encompassing post-combustion, pre-combustion, and oxy-fuel combustion ...... application of membrane technology for post-combustion CO- capture is very challenging mainly because of the low pressure of flue gas strcams. Membranes are more suitable for high- pressure precombustion processes. Membrane-based CO» separation involves multistage operation and streams recycling, which ...
... strongly dependent on reservoir temperature, pressure and crude oil composition. These mechanisms range from oil swelling and viscosity reduction for injection of immiscible fluids (at low pressures) to completely miscible displacement in high-pressure applications. In these applications, more than ...
... s. Characteristics of the adsorbents in addition to the process design influence the efficiency and economics of adsorption processes such as pressure/temperature swing adsorption. [32] Metrics for adsorption capture include high working capacity and selectivity, low cost, low regeneration r ...John Nyame. Analysis Of the Process Of Carbon Capture Utilization And Storage In Underground Reservoirs, 2024
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An oilfield in Libya: A new model to enhance waste water disposal
Dušan Danilović, Vesna Karović Maričić, Nori Elhaddad, Branko Leković. "An oilfield in Libya: A new model to enhance waste water disposal" in Energy & Environment (2016)
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Оцјена водопропусности понорске зоне Шуковићу (Цернићко поље) помоћу Лижоновог теста
One of the specificities of reservoirs forming in highly karstified terrains is reflected in the wide range of unknowns, specifically during reservoir formation, filling and operation. Unfortunately, despite complex research, many reservoirs constructed in karst terrains have problems with water losses from the reservoir to other aquifers due to ponor and ponor zones which are a common in the karst of Eastern Herzegovina. One of such zones is Šuković ponor located in the southern part of the Cerničko polje ...Петар Војновић, Саша Милановић, Љиљана Васић. "Оцјена водопропусности понорске зоне Шуковићу (Цернићко поље) помоћу Лижоновог теста " in Мултидисциплинарна конференција “Kарст 2022 - Значај, стање и перспективе коришћења и заштите ресурса у карсту", Српска академија наука и уметности (2022)
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Development and Application of Methodology for Quantification of Overbreaks in Hard Rock Tunnel Construction
A methodology for determining overbreaks in hard rock tunnel construction using the drill-and-blast technique is presented in this paper. The methodology was developed for and applied to crystalline medium- to thick-bedded limestone, but it can be used in any jointed hard rock mass. Overbreaks are inevitable in hard rock tunnelling in a low-confinement environment (shallow tunnels up to several hundred meters deep) as a result of wedge failures along unfavourably oriented discontinuities caused by blasting. It is widely accepted ...hard rock, drill-and-blast, geological overbreak, technological overbreak, stability criterion, discontinuity orientation, tunnel constructionZoran Berisavljević, Dragoljub Bajić, Vojkan Jovičić. "Development and Application of Methodology for Quantification of Overbreaks in Hard Rock Tunnel Construction" in Applied Sciences, MDPI (2023). https://doi.org/10.3390/app13031379
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Održiva eksploatacija izvorišta mineralnih voda na primeru Vrnjačke banje
Vladimir Živanović, Veselin Dragišić, Sava Magazinović, Jakov Andrijašević, Nebojša Atanacković (2022)Jedna od najznačajnijih i najposećenijih banja u Srbiji je Vrnjačka Banja koja je poznata po bogatstvu i dugoj istoriji korišćenja mineralnih voda. Obimna hidrogeološka istraživanja izvedena proteklih nekoliko decenija ukazala su na ograničenost rezervi mineralnih voda u uslovima dosta složene hidrogeološke građe područja pojavljivanja. Poslednjih godina eksploatacija ovog dragocenog resursa zadobija novu dimenziju, naročito nakon privatizacije pojedinih hotelskih kompleksa kada se povećavaju potrebe za mineralnim vodama i od kada počinje izrada novih vodozahvata što dovodi u pitanje održivu eksploataciju ...mineralne vode, izvorišta mineralnih voda, održivo korišćenje mineralnih voda, monitoring mineralnih voda, Vrnjačka BanjaVladimir Živanović, Veselin Dragišić, Sava Magazinović, Jakov Andrijašević, Nebojša Atanacković. "Održiva eksploatacija izvorišta mineralnih voda na primeru Vrnjačke banje" in Zbornik radova XVI srpskog Simpozijum o hidrogeologiji sa međunarodnim učešćem, Univerzitet u Beograd, Rudarsko-geološki fakultet (2022)
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Потреба за израдом биланса и оценом расположивих резерви подземних вода Републике Србије
Природне карактеристике Србије, просторна дистрибуција ресурса водe и њихових корисника, као и међусобна интеракција коришћења, заштите вода, као и заштите од вода, условиле су да се подземне воде на читавој територији морају посматрати интегрално, јединствено, комплексно и рационално. Међутим, тренутно је у Републици Србији могуће дефинисати само одлике појединих издани и/или изворишта услед непостојања довољних података за свеобухватну анализу стања ресурса. За оцену притиска на квантитет ресурса подземних вода, што је обавеза према Оквирној директиви о водама ЕУ (ОДВ) ...Зоран Стевановић, Вељко Мариновић, Бранислав Петровић. "Потреба за израдом биланса и оценом расположивих резерви подземних вода Републике Србије" in Записници Српског геолошког друштва, Српско геолошко друштво (2021)
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Geostatički proračuni sanacije klizišta šipovima
U ovom radu su, polazeći od rezultata geotehničkih istraživanja, prikazani geostatički proračuni sanacije klizišta vertikalnim šipovima. Metodologija proračuna je složena, jer podrazumeva interakciju klizišta i stabilizirajućih šipova. Stoga se simultano analiziraju stabilnost klizišta i stabilnost šipova. Prilikom određivanja bočne otpornosti tla oko šipova koristi se metoda Brinč Hansena koja uzima u obzir trodimenzionalne uslove u tlu i može da se primeni u složenim geološkim uslovima koji su česti u Srbiji. Analize stabilnosti klizišta vrše se odgovarajućim metodama granične ravnoteže. ...sanacija klizišta, interakcija klizišta i šipa, bočna otpornost šipova, stabilnost klizišta i šipova... kohezije (Brinč Hansen, 1961) Figure 3. Coefficient of lateral pressure which is dependent of cohesion (Brinch-Hansen, 1961) Slika 2. Koeficijent bočnog pritiska tla koji zavisi od vertikalnog, napona Figure 2. Coefficient of lateral pressure which is dependent of verftical stress (Brinch-Hansen, ...Slobodan Ćorić, Dragoslav Rakić, Dušan Berisavljević. "Geostatički proračuni sanacije klizišta šipovima" in Zbornik radova osmog naučno-stručnog međunarodnog savetovanja - Geotehnički aspekti građevinarstva, Savez građevinskih inženjera Srbije, (2019)
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Analysis and Calculation of MMRS and Primary Gas Distribution Network in Urban Environment – Case Study Kučevo
Aleksandar Madžarević, Pavle Janković (2022)Oblast primene prirodnog gasa je veoma široka. Kao energent može se koristiti za proizvodnju energije u elektranama, toplanama i postrojenjima za kombinovanu proizvodnju energije ili za zadovoljavanje različitih toplotnih potreba u industriji i širokoj potrošnji. Gas se može upotrebiti i kao sirovina u hemijskoj i petrohemijskoj industriji, a tokom poslednjih decenija nalazi primenu i u saobraćaju kao pogonsko gorivo u SUS motorima. Sa ekološkog stanovišta, prirodni gas predstavlja najprihvatljiviji izvor energije u poređenju sa drugim fosilnim gorivima. Pri sagorevanju ...Aleksandar Madžarević, Pavle Janković. "Analysis and Calculation of MMRS and Primary Gas Distribution Network in Urban Environment – Case Study Kučevo" in Međunarodni Kongres o procesnoj industriji - PROCESING '22, Beograd : SMEITS, Društvo za procesnu tehniku (2022)
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Синтеза и карактеризација керамике на бази сфена
Jelena R. Pantić (2015-07-10)Механохемијска активација стехиометријске смеше реактаната TiO2, SiO2 и CaCO3 показала се као веома успешна и једноставна метода за добијање сфена (CaTiSiO5). На основу мерења релативних густина свих синтерованих узорака установљено је да максималну густину од 93,9 % имају узорци који су активирани 30 минута и синтеровани на 1200 °С. Микроструктурном анализом, тј. анализом слика синтерованих узорака активираних 30 минута, које су добијене скенирајућом електронском микроскопијом, опажа се бимодална расподела величине зрна, са просечном величином од 3 μm, односно 5 ...сфен, механохемија, Ритвелдова метода, оптичка спектроскопија, микроструктурна анализа, фазна трансфоpмација, чврсти раствори... high pressure phases, mechanochemicaly activated sphene was treated by high pressure - high temperature synthesis process. Samples were sintered at pressure of 3.5±0.2 and 4.0±0.2 GPa and at temperature of 1100 and 1200±50 °C. The highest achieved densitу have samples sintered with pressure of ...
... at high pressure and high temperature. Am Mineral 85: 1465-1473. Kunz M. and Brown I.D. (1994) Out of center distortions around octahedrally coordinated d0-transition metals. J Solid State Chem 115: 395-406. Kunz M., Xirouchakis D., Lindsley D.H. and Hauserman D. (1996) High- pressure phase ...
... electron microscope, suggesting that the particles are composed of packed crystallites. Also, reduction of particle size occurred during high pressure compaction. Keywords: ѕphene, mechanochemistry, Rietveld refinement, optical spectroscopy, microstructural analysis, phase transition, solid ...Jelena R. Pantić. "Синтеза и карактеризација керамике на бази сфена" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2015-07-10)
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Синтеза и карактеризација керамике на бази сфена
Jelena R. Pantić (2015-07-10)Механохемијска активација стехиометријске смеше реактаната TiO2, SiO2 и CaCO3 показала се као веома успешна и једноставна метода за добијање сфена (CaTiSiO5). На основу мерења релативних густина свих синтерованих узорака установљено је да максималну густину од 93,9 % имају узорци који су активирани 30 минута и синтеровани на 1200 °С. Микроструктурном анализом, тј. анализом слика синтерованих узорака активираних 30 минута, које су добијене скенирајућом електронском микроскопијом, опажа се бимодална расподела величине зрна, са просечном величином од 3 μm, односно 5 ...сфен, механохемија, Ритвелдова метода, оптичка спектроскопија, микроструктурна анализа, фазна трансфоpмација, чврсти раствори... high pressure phases, mechanochemicaly activated sphene was treated by high pressure - high temperature synthesis process. Samples were sintered at pressure of 3.5±0.2 and 4.0±0.2 GPa and at temperature of 1100 and 1200±50 °C. The highest achieved densitу have samples sintered with pressure of ...
... at high pressure and high temperature. Am Mineral 85: 1465-1473. Kunz M. and Brown I.D. (1994) Out of center distortions around octahedrally coordinated d0-transition metals. J Solid State Chem 115: 395-406. Kunz M., Xirouchakis D., Lindsley D.H. and Hauserman D. (1996) High- pressure phase ...
... electron microscope, suggesting that the particles are composed of packed crystallites. Also, reduction of particle size occurred during high pressure compaction. Keywords: ѕphene, mechanochemistry, Rietveld refinement, optical spectroscopy, microstructural analysis, phase transition, solid ...Jelena R. Pantić. "Синтеза и карактеризација керамике на бази сфена" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2015-07-10)
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A Knowledge-Based Approach to Mine Ventilation Planning in Yugoslav Mining Practice
Ventilation system analysis is a complex process based on the calculation and analysis of numerous parameters. These problems can be successfully solved by the SimVent numerical package, but a full understanding and use of the obtained results require the involvement of an experienced specialist in the ventilation field. The solution was found in the creation of a hybrid system INVENTS, whose knowledge base represents a formalization of the expert knowledge in the mine ventilation field. In this paper, we ...... the pressure of the booster fan varies in wide limits of given values from 10 Pa to 600 Pa. The variable related to the location of the fan takes values from a predetermined set of branches where the introduction of booster fans is permitted (branches 1, 3, 5, 7, 9, 14, 15, 16). The pressure of the ...
... global structure of the mathematical model used as the basis for SimVent is composed of the following: (i) a block for the analysis of air flow and pressure distribution in the ventilation network, (ii) a block for the analysis of climate conditions in mine workings, (iii) a block for temperature and ...
... system state of the “Soko” mine the following measurements were initially undertaken: temperatures of the dry and wet bulb thermometer and barometric pressure in mine ventilation nodes were measured, as well as the air flow volumes in network branches. The data obtained were used as input for the ResNet ...Nikola Lilić, Ivan Obradović, Ranka Stanković. "A Knowledge-Based Approach to Mine Ventilation Planning in Yugoslav Mining Practice" in Mineral Resources Engineering 11 no. 4, Imperial College Press (2002): 361-382. https://doi.org/10.1142/S0950609802001014
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Application of Lignite Combustion Waste Slag Generated in Heating Plants as a Partial Replacement for Cement. Part II: Physical–Mechanical and Physical–Chemical Characterization of Mortar and Concrete
Milan Kragović, Nenad Ristić , Jelena Gulicovski, Andrijana Nedeljković, Snežana Pašalić, Ivica Ristović, Marija Stojmenović (2021)sagorevanje lignita, otpadna šljaka, zamena cementa, proizvodnja maltera i betona, fizičko-mehanička i fizičko-hemijska karakterizacija... measuring range of 0 to 250 kN of the compressive force and accuracy class 0.5%. Water absorption (determination of water absorption at atmospheric pressure) was determined according to EN 13755 and was conducted on the prisms with dimensions 40 mm × 40 mm × 160 mm. Prisms were firstly dried at the temperature ...
... The percentage difference of masses of a saturated and a dry sample, and the mass of the dry sample represents the water absorption at atmospheric pressure. Water absorption (determination of water absorption coefficient due to capillary action of hardened mortar) was performed according to standard ...
... a metal, cylindrical vessel with a capacity of 8 dm3. Air content in fresh concrete was determined according to standard EN 12350-7 by using the pressure method. For testing, an apparatus was used which consisted of a metal cylindrical vessel with a capacity of 8 dm3 and a special lid with a pump and ...Milan Kragović, Nenad Ristić , Jelena Gulicovski, Andrijana Nedeljković, Snežana Pašalić, Ivica Ristović, Marija Stojmenović . "Application of Lignite Combustion Waste Slag Generated in Heating Plants as a Partial Replacement for Cement. Part II: Physical–Mechanical and Physical–Chemical Characterization of Mortar and Concrete" in Minerals, MDPI (2021). https://doi.org/10.3390/min11090925
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From post-disaster landslides inventory to open landslides data
Biljana Abolmasov, Miloš Marjanović, Uroš Đurić, Jelka Krušić. "From post-disaster landslides inventory to open landslides data" in Proceedings of 3rd European Regional Conference of IAEG/ Athens/ Greece/ 6-10 October 2021, International Association for Engineering Geology and the Environment (2021)
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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 ...... Phil Wilson explained the HP [6]. As the main factors geographical and environmental restrictions were taken, the secondary factors were reservoir pressure, productivity index, the characteristics of reservoir fluids, and well productivity characteristics. The importance of this work is reflected in ...
... technical limitations of the methods applied. The parameters considered are: pump volume capacity, the depth in combination with the desired dynamic pressure at the bottom of the well, the deviation of the well, and characteristics of the reservoir. The second step further reduces the choice, based on ...
... parameters were not considered [11–14]. Input parameters can be grouped into three groups: I. Characteristics of reservoir, well and fluid (depth, pressure, production, and technical limitations of artificial lift methods) Energies 2020, 13, 1758 4 of 15 II. Conditions in which the well operates ...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)