Претрага

Упит dcterms_subject_txt:borehole pressure

172 items

  • The analysis of the geothermal energy capacity for power generation in Serbia

    Jana Stojković, Goran Marinković, Petar Papić, Mihailo Milivojević, Maja Todorović, Marina Ćuk (2013)
    Renewable Energy, Sustainability and the Environment
    ... dioxide pressure. This gave a more realistic temperature estimate than in other sources, because calcite deposition was prevented which would have given higher fluid temperature [12, 13]. Different researchers reported sensitiv- ity of the Na-K-Ca geothermometer to the partial pressure of CO2 [14] ...
    ... resource in Serbia. The highest measured temperature of geothermal water, published in the Geothermal Atlas of Vojvodina, is 82 °C in NE Banat (Vrbica, borehole Vbc 1/H). The potential sources are able to yield groundwater of 100-150 °C temperatures from a depth of 2-3 km. These tempera- tures regrettably ...
    ... solubility; sol- ubility in water of different silica forms (quartz, chalcedony, and amorphous silica) were mea- sured in relation to temperature and pressure. This geothermometer is used for the fluids hotter than 150 °C. For lower fluid temperatures, chalcedony is used, which controls the amount of dis- ...

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

    David Petrović, Lazar Kričak, Milanka Negovanović, Stefan Milanović, Jovan Marković, Nikola Simić, Ljubisav Stamenić (2019)
    In the name of a better and safer energy future, it is our responsibility to focus our knowledge and activities to save on imported liquid and gas fossil fuels, as well as coal on which energy security of Serbia is based. The rationalization in the use of available energy resources certainly positively affects economy and the environment of a country. This paper indicates motivations for the application of the underground coal gasification process, as well as surface gasification for ...
    ugalj, gasifikacija, zaštita životne sredine, skladištenje, solarna
    ... textile soaked with petroleum could be used by throwing it into the injection borehole under the pressure of the gasifica- tion agent such as air or oxygen. To start the UCG process, the bottom of the borehole is adjusted to about 0.5 m from the bottom of the coal layer. To form a channel ...
    ... cracks in the deep rock formations through which gases flow. The coal layer is usually ignited by inserting a hot coke through the borehole and blowing the low pressure air. Instead of firing coal layer with the coke at high temperatures, a – — —- 225 – — — Product gas W j ii manifold 75 75 i 75 ...
    ... nearly hor- izontal borehole drilled through the coal layer, which connects the vertical boreholes. The first step in drilling involves the drilling: of injection and production bore- holes. In order to achieve the most efficient use of coal resources, the borehole grid is drilled through ...

  • Стратешко планирање функционалности подземних просторија моделом прогнозе деформација

    Лука Црногорац (2023)
    Релативно велике деформације подградне конструкције у подземним рудницима угља у Републици Србији представљају један од главних проблема за постизање планиране производње угља. Деформације подграде су директна последица статичких и динамичких оптерећења стенске масе и у многоме зависе и од времена трајања изложености подграде утицају подземног притиска. Код ниско механизованог радног процеса долази до повећаног излагања подземних просторија утицају подземног притиска услед дугог производног циклуса који је често пропраћен застојима у раду. Веома често подземне просторије се санирају и по ...
    подземне просторије, подграда, прогноза деформација, стратешко планирање

  • Mine ventilation system planning using genetic algorithms

    Nikola Lilić, Ranka Stanković, Ivan Obradović (1997)
    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 methods

  • 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 ...

  • Simulation of Hydrogeological Environmental Discharge in Case of Interruption Constant Observations

    Marina Čokorilo Ilić, Dragoljub Bajić, Miroslav Popović (2024)
    Monitoring Network, data, hydrogeological environment, tunnel, simulation

  • Избор одговарајуће механичке методе

    Анастасија Мирјанић (2024)
    Експлоатација нафте и гаса кључна је за задовољење глобалних енергетских потреба. Различите методе се користе за ефикасно вађење тих природних ресурса из земљe. Механичке методе експлоатације, које укључују различите врсте пумпи и компресора, играју значајну улогу у овом процесу. У нафтној индустрији, ефикасно вађење нафте и гаса зависи од избора одговарајуће технологије пумпања. Две од најраспрострањенијих технологија су дубинске пумпе са клипним шипкама (енгл. Sucker rod pumps- SRP) и електричне потапајуће пумпе (енгл. Electrical submersible pump- ESP). Овај завршни рад ће ...
    дубинске пумпе са клипним шипкама, замена, електрична потапајућа пумпа, производња, бушотина

  • Hidraulički tranzijenti u karstnoj sredini tokom rada hidroelektrane

    Maja Todorović, Marina Ćuk Đurović, Igor Jemcov (2023)

  • Numerical modeling of Selanac debris flow propagation using SPH code

    Jelka Krušić, Biljana Abolmasov, Miloš Marjanović, Manuel Pastor, Saeid M. Tayyebi (2021)
    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 ...
    debris flow, modelling, SPH code, DEM
    ... 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 ...

  • Determination of Mechanical Properties of Altered Dacite by Laboratory Methods

    Veljko Rupar, Vladimir Čebašek, Vladimir Milisavljević, Dejan Stevanović, Nikola Živanović (2021)
    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 ...
    Geology, Geotechnical Engineering, Engineering Geology
    ... 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 ...

  • 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 ...
    Carbon Capture, Utilization and Storage
    ... 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 ...

  • An oilfield in Libya: A new model to enhance waste water disposal

    Dušan Danilović, Vesna Karović Maričić, Nori Elhaddad, Branko Leković (2016)
    нафта, лежишне воде, припрема

  • Geotechnical Conditions for Construction of Savski Trg Metro Station as a Part of the Belgrade Metro Line One

    Nemanja Stanic, Dragoslav Rakic, Josip Isek, Slavoljub Simic (2024)
    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 ...
    metro station, geotechnical modelling, displacements

  • Оцјена водопропусности понорске зоне Шуковићу (Цернићко поље) помоћу Лижоновог теста

    Петар Војновић, Саша Милановић, Љиљана Васић (2022)
    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 ...
    карст, Шуковића понор, Церничко поље, водопропусност, Лижонов тест

  • Development and Application of Methodology for Quantification of Overbreaks in Hard Rock Tunnel Construction

    Zoran Berisavljević, Dragoljub Bajić, Vojkan Jovičić (2023)
    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 construction

  • 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 Banja

  • Geostatički proračuni sanacije klizišta šipovima

    Slobodan Ćorić, Dragoslav Rakić, Dušan Berisavljević (2019)
    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, ...

  • Потреба за израдом биланса и оценом расположивих резерви подземних вода Републике Србије

    Зоран Стевановић, Вељко Мариновић, Бранислав Петровић (2021)
    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) ...
    подземни водни ресурси, биланс, расположиве резерве, одрживо управљање, Република Србија

  • 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 ...
    distribucija gasa, projektovanje gasovoda, analiza potrošnje

  • 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 ...