Претрага
351 items
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Laboratory Testing of Nanosilica- Reinforced Silicate and Polyacrylamide Gels
Irina Zahirovic, Dušan Danilović, Milica Šuput Vranjin, Miloš Tripković. "Laboratory Testing of Nanosilica- Reinforced Silicate and Polyacrylamide Gels" in SPE Journal (2023)
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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 ...... Exergy loss (AEx loss), which indicates exergy destruction, necessarily occurs in systems because of heat transfer, fluid friction, and energy dissipation with respect to the surrounding environment. The following equations present the exergy loss in different equipment. The exergy loss in each ...
... to the calculation of the exergy loss for a pump. In contrast, the power produced in a turbine is subtracted from the exergy loss of a turbine Pump: AEX loss= n'(eXin-eXou)+W"p (11) Turbine: AEx loss=h(eXin-eXout)-W"'t (12) Heat exchanger: AEx loss= Žni=1ni(exi,in—exu,om) (13) Life ...
... žExergy gained Tl}ex = K ——— (6) žExergy expenditure Then, exergy gained in a system and exergy loss in each equipment are: žExergy gained=>Exergy expenditure-ž>Exergy loss (7) ž>Exergy loss=>h'id*eXin >h ou* eXouch2 ıQ ı *(1—To/Ti)+bj-W"j (8) Where; Ti -initial temperature To -final ...John Nyame. Analysis Of the Process Of Carbon Capture Utilization And Storage In Underground Reservoirs, 2024
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Design of a sucker rod pumping system
Ana Ponoćko (2024)For a long time in the history of oil production, sucker rod pumps have been the first and in many cases the only choice when it comes to mechanical extraction methods. Proper selection of each individual element of the system enables optimization, which entails benefits in the form of increased efficiency and reduced costs. The first part of the paper presents the underground and surface equipment of the rod pump and describes the operation of the entire system. The ...... qs= fluid loss trought the gap m*/d • K= empirical constant 11 • d= diameter of the plunger • Ap= pressure differential • G= clearance between the plunger and the cylinder • M= fluid viscosity • L=length ofthe plunger • Aand B= exponents The amount of leakage, or fluid loss through ...
... clearances from 0.001 in to 0.005 in. The amount of fluid leakage through the space (clearance) between the plunger and the cylinder is determined based on experimental data and is expressed in various forms. The general equation for fluid loss through the clearance between the plunger and the cylinder ...
... necessary to consider and determine the "damping force." Due to the pumping cycle, there is a continuous and irreversible loss of energy caused by the viscous forces of the fluid on the surface of the pump [15]. Final form of the One-Dimensional Wave Equation describing forces propagating along ...Ana Ponoćko. Design of a sucker rod pumping system, 2024
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Linear-motor plunger pump increases lifting efficiency
Bojan Martinović, Dušan Đekić, Dušan Danilović, Pavel Isaev. "Linear-motor plunger pump increases lifting efficiency" in Oil & Gas Journal (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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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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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 ...... system as acceptable, while the “air loss” characteristic was estimated as bad. The latter can be explained by considerable air loss in the system, which influences the effective utilization of the overall air stream, used for the ventilation of the pit. Total air loss in the ventilation system is very ...
... (Figs. 10 and 11). The air loss coefficient is calculated as a ratio of the volume of air loss and the total air flow volume. The value of this coefficient for the “Soko” mine ventilation system was 0.46 (19.6/42.4) which lead to an unfavorable estimation of the air loss characteristic of the ventilation ...
... value of the airflow loss frequency parameter in the system, which is the ratio of the number of air loss branches and the total number of branches, was 0.28 (5/18). This value also leads to an unfavourable estimation of the ventilation system state of the “Soko” mine when air loss is considered. When ...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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Laboratory testing of fly ash
Fly ash is one of the most common waste materials created by burning of coal. It is composed of smaller particles, consisting mainly of aluminosilicate glass, mullite and quartz, which are collected by electrostatic separators (filter) of gaseous products arising from the combustion of coal. This paper presents the pozzolanic properties, mechanical properties, chemical and mineral composition of fly ash obtained in the combustion process in a power plant Nikola Tesla A (PPNT A) with the addition of a ...chemical composition, fly ash, mechanical properties, mineral properties, pozzolanic properties, X-ray diffraction... samples with the lime have lower values (Fig. 8). The correlation coefficient with the cement content and the control sample is calculated and is 0,990, and with the lime content and the control sample is 0,899. After the calculated coefficient values it can be seen that the samples with the cement belong ...
... that contain the lime as the binder (Fig. 9). The correlation coefficient with the lime content and the control sample is calculated and is 0,966, and with the cement content and the control sample is 0,954. After the calculated coefficient values it is found that the samples with the lime and the ...
... that contain the lime as the binder (Fig. 11). The correlation coefficient with the lime content and the control sample is calculated and is 0,917, and with the cement content and the control sample is 0,686. After the calculated coefficient values it is obtained that the samples with the lime belong ...Miloš Šešlija, Aleksandra Rosić, Nebojša Radović, Milinko Vasić, Mitar Đogo, Milovan Jotić. "Laboratory testing of fly ash" in Tehnički vijesnik (2016). https://doi.org/10.17559/TV-20150317171035
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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... into account for the choice of analytical methods that allow its full characterization and quality control. None of the spectroscopic methods used in this study was suitable for the quality control of all types of chars. Other methods like thermochemical characterization and the quantitative de ...
... is best discussed by a van Krevelen diagram (Fig 2) [52,75]. All chars except PW700g show a higher H/C and a lower O/C ratio than expected for the loss of water from formal car- bohydrate (CH»O), the elementary building block of plant biomass, as represented by the 2.0 w= chars — — – line C ...
... combustion for the ash determination. Therefore, it cannot have been present as phosphate, but as phosphoric acid which decomposes above 213 "C by loss of water. The resulting P,O,o sublimes above 362 "C and is not part ofthe ash. Consequently, Y is lower than Y„„x for AC2 in contrast to all other ...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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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 ...Seyed Ali S. Razeghi. Razvoj modela upravljanja cirkulacijom u postupku bušenja korišćenjem neuro fazi sistema zaključivanja, Beograd : [S. Razeghi], 2022
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Complex geophysical survey on solving the problem of water loss in the karst terrain reservoir
Branislav Sretković, Dejan Vučković (2023)Geophysical surveys in karst terrain are always a specific challenge. Each of them requires a careful consideration of the problem, specific conditions on the ground, the selection of adequate methods applicable in that specific and unique karst area. But they should have one thing in common: a complex approach and looking at the problem from wider to narrower, with a gradual narrowing of the investigation area, increasing the spatial precision and resolution of the obtained data. On the example of ...Branislav Sretković, Dejan Vučković. "Complex geophysical survey on solving the problem of water loss in the karst terrain reservoir" in 8th Symposium Geoscience 2023, Bucharest, 9-11. November 2023, Bucharest : Editura Cetatea de Scaun (2023)
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1977 jovac landslide – a New Overlook on Environmental Effects and Material Loss
Jevremović Dragutin, Kostić Srđan (2011)Jevremović Dragutin, Kostić Srđan. "1977 jovac landslide – a New Overlook on Environmental Effects and Material Loss" in The Geology in Digital Age : proceedings of the 17th Meeting of the Association of European Geological Societies, MAEGS 17, Belgrade, [14-18. 09.] 2011., Belgrade:The Serbian Geological Society (2011): 14-18
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Determination of wather loss from reservoirs in less permeable karst aquifer- case example of left bank of Lazici dam- western Serbia
Jemcov Igor, Mladenović Ana, Pavlović Radmila, Trivić Branislav, Petrović Dragana, Petrović Rastko (2014)Jemcov Igor, Mladenović Ana, Pavlović Radmila, Trivić Branislav, Petrović Dragana, Petrović Rastko. "Determination of wather loss from reservoirs in less permeable karst aquifer- case example of left bank of Lazici dam- western Serbia" in Proceedings of International conference and field seminar „Karst without boundaries“, 11-15 June 2014, Trebinje, Dubrovnik, Trebinje:Grafokomerc (2014): 307-312
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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... s. lss aisesaa 9 Slika 6-3: Unos PVT osobina fluida |# \ Inflow Performance Relationship (IPR) Input (K-1.Out) (Matched PVT) || x Trarcient. Herizontai W/el -No ov Boundares | y Horizontal Vel - dP Fricion Loss 1n Welore Muti ayer -cP Loss n WWelRore Sinace |RF) Duslpercsity Herizontal ...
... koji je primenio glavni pokretač na pumpi predaje lopaticama radnog kola koje dalje predaju energiju fluidu, gde se povećava brzina kretanja fluida i tako sama kinetička energija fluida. Fluid velike brzine strujanja koji se ispušta pod uglom od horizontale zatim ulazi u lopatične kanale difuzora ...
... regulisana opštom energetskom Jednačinom koja opisuje očuvanje energije između dve tačke u fluidu koji teče. Ovo navodi da je promena energije u sadržaju fluida je jednak radu obavljenom na fluid. Fluid koji teče u pumpi može imati tri oblika energije: potencijalnu, kinetičku i pritisnu energiju ...Aleksandar Sredojević. Analiza softvera za projektovanje ESP sistema, 2024
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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 ...Стефан Петровић, Милош Велојић. "Значај петрографске анализе флуидних инклузија " in Записници српског геолошког друштва, Српско геолошко друштво, Београд (2022)
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Analysis and visualization of geophysical well-logging data from closely spaced boreholes
Geophysical logging measurements for determining the condition of the rock mass on the dam profile and locating the predisposed directions of water circulation and loss from the reservoir were conducted in four boreholes distributed at a close distance. The survey was carried out in a typical karst terrain, which is an additional challenge for defining the geological model, especially in terms of water retention. That kind of data set provides an excellent opportunity for a new approach to analysis ...... logging measurements for determining the condition of the rock mass on the dam profile and locating the predisposed directions of water circulation and loss from the reservoir were conducted in four boreholes distributed at a close distance. The survey was carrled out in a typical karst terrain, which ...
... be a very useful tool for analyzing the condition of a rock mass between boreholes, not only inside them. Key words: well-logging in karst, water loss, data correlation, data fusion INTRODUCTION The application of modern geophysical surveys in karst terrains is of particular importance when ...
... hydrogeological research, as well as based on the data from exploratory works during the construction of the dam itself, that determined the greatest loss of water takes place under the very body of the 100 concrete gravity dam, up to the depths that conventional surface geophysical methods cannot ...Branislav Sretković, Ivana Vasiljević, Dimitry Sidorov - Biryukov. "Analysis and visualization of geophysical well-logging data from closely spaced boreholes" in Vth Congress of the Geologists of the Republic of North Macedonia, Ohrid, Republic of North Macedonia, September 27-28, 2024, Macedonian Geological Society (2024)
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A proposal for the landslide damage questionnaire in suburban areas
Landslides are one of the most often natural disasters that have an extensive impact on society including loss of life, destruction of infrastructure and properties, damage to land and loss of natural resources. Landslide losses can significantly vary and they depend on a variety of different criteria such as the size and type of landslide, lithological setting of terrain, the terrain slope gradient, the quality of materials used for construction, and the construction typology. Damage from landslides is usually ...Uroš Đurić, Biljana Abolmasov, Miloš S. Marjanović, Sanja Jocković, Miloš D. Marjanović. "A proposal for the landslide damage questionnaire in suburban areas " in 5th Regional symposium on landslides in Adriatic–Balkan Region, 23-26 March 2022, Faculty of Civil Engineering, University of Rijeka and Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb (2022)
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Damage quantification of built stone on Dark Gate (Belgrade, Serbia): sample of damage index application for decay rate evaluation
The Dark Gate is the monument of culture, part of the cultural and historical complex of the Belgrade Fortress. It is constructed of limestone blocks that after 270 years of exposure to environmental conditions and different anthropogenic influences show wide ranges of decay forms. During 2007, detail registration of all built limestone microfacies and weathering forms was done using tools of monument mapping. A correlation scheme ‘‘intensity– damage category’’ was made according to the type, intensity, and distribution of ...... visible damage” was not observed. As far as groups of weathering forms are concerned, most dominant are loss of stone material, deposits in the form of crusts and detachment (Fig. 4). Loss of stone material is generally presented as surface recession and relief, only occasionally as outburst ...
... and very heavy damage are blocks with a significant loss of material that disrupts the original appearance of the stone element (Fig. 4b, d, f damage cate- gory 4 and 5 in Table 1). Moderate damage is manifested on stone blocks where loss of material is superficial (Fig. 4c, e damage category ...
... weathering features, it is evident that algal rudstone microfacies are characterized by loss of stone materials in forms of surface recession and outburst, while grainstone microfacies is marked by relief loss of stone materials and detachment of crust following by granular disintegration and flaking ...Maja Franković, Nevenka Novaković, Vesna Matović. "Damage quantification of built stone on Dark Gate (Belgrade, Serbia): sample of damage index application for decay rate evaluation" in Environmental Earth Sciences, Springer Science and Business Media LLC (2015). https://doi.org/10.1007/s12665-014-3843-z
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Increasing the Local Road Network Resilience from Natural Hazards in Municipalities in Serbia
Biljana Abolmasov, Miloš Marjanović, Ranka Stanković, Uroš Đurić, Nikola Vulović. "Increasing the Local Road Network Resilience from Natural Hazards in Municipalities in Serbia" in Progress in Landslide Research and Technology, Volume 3, Issue 1, Springer Cham. (2024). https://doi.org/https://doi.org/10.1007/978-3-031-55120-8_22
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Mineralogical study of clays from Dobrodo, Serbia, for use in ceramics
Maja Milošević, Predrag Dabić, Sabina Kovač, Lazar Kaluđerović, Mihovil Logar. "Mineralogical study of clays from Dobrodo, Serbia, for use in ceramics" in Clay Minerals, Mineralogical Society (2019). https://doi.org/10.1180/clm.2019.49