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Упит dcterms_subject_txt:Standards for LRs

1407 items

  • Geotechnical aspects for construction of bank revetment along the Sava river for the “Belgrade waterfront”

    Rakić Dragoslav, Basarić Irena, Stanić Nemanja, Filipović Vladimir, Berisavljević Dušan (2018)

  • Design and drilling of wells in formations with high pressure

    Vojin Solomun (2024)
    Objectives of this Thesis are to: - Develop an awareness of the challenges presented from elevated temperatures and pressures in well construction. - Learn the key differences between ―normal‖ condition wells and HPHT wells. - Understand some of the indicators of thermal- and pressure-related problems. - Understand the responses which may be made to mitigate high pressure and high temperature ,,HPHT‘‘ challenges while drilling wells. HPHT wells are an unavoidable consequence of the ever expanding search for oil and gas resources around the world. As wells are ...
    HPHT, well, challenges, design, oil and gas
    ... is fit-for-service in deeper, HPHT wells. The HPHT and deepwater well standards follow the publication in 2013 of a related document, API Standard 53, Blowout Prevention Equipment Systems for Drilling Wells. Norwegian Oil and Gas association, Guideline no. 117, Recommended guidelines for Well ...
    ... DS-1. UK Oil and Gas OP071, Guidelines for the suspension and abandonment of wells, Issue 4, July 2012 and Guidelines on qualification of materials for the suspension and abandonment of wells. At present, no design guidelines or standards have been developed for 2070 bar surface equipment, especially ...
    ... strength accepted in conventional sour environments meeting Canadian IRP 1.8 Compliance. Grades to 120 are available for milder environments but may not meet any industry standards for sour service. With the deep setting of the surface casing, larger drill strings are often used. The use of 168.275 ...

  • Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae

    Hans Peter Nytoft, Geir Kildahl-Andersen, Sofie Lindström, Frode Rise, Achim Bechtel, Danica Mitrović, Nataša Đoković, Dragana Životić, Ksenija A. Stojanović (2019)
    Two previously unidentified dehydroabietane isomers were isolated from Miocene Serbian lignite and Rhaetian (Late Triassic) coaly mudstones from South Sweden and characterized using NMRspectroscopy as cis- and trans-dehydroicetexane. Both have a 9(10?20)-abeo-abietane or icetexane skeleton, consisting of a 6-7-6 tricyclic framework with seven carbons in ring B instead of the usual six in common diterpanes of the abietane-type. Dehydroicetexanes can be detected using GC-MS-MS in m/z 270?146 chromatograms without interference from dehydroabietane or other isomers. Dehydroicetexanes are often abundant ...
    Geochemistry and Petrology

  • Regional Slope Stability Analysis in Landslide Hazard Assessment Context, North Macedonia Example

    Miloš Marjanović, Biljana Abolmasov, Igor Peshevski, James Reeves, Irena Georgievska (2020)

  • Adaptive neuro-fuzzy prediction of operation of the bucket wheel drive based on wear of cutting elements

    Filip Miletić, Predrag D. Jovančić, Milos Milovančević, Dragan Ignjatović (2020)
    The capacity of the rotor excavator depends largely on the operation of the subsystem for digging. There is a great contribution to the correct and sharp teeth when the capacity is the highest. In the function of time, the teeth become clogged due to abrasive wear, or changes in their geometric shape. To analyze the bucket wheel drive in depend on wear of the cutting elements in this study adaptive neuro fuzzy inference system (ANFIS) approach was implemented. ANFIS ...
    Pogon rotornog točka, habanje, rezni elementi, ANFIS

  • A Knowledge-Based Approach to Mine Ventilation Planning in Yugoslav Mining Practice

    Nikola Lilić, Ivan Obradović, Ranka Stanković (2002)
    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 ...
    ... interface forms for the ResNet software package. • VENTEX, the diagnostic expert system for the analysis of ventilation systems are developed for IBM PC and compatible computer systems. The object-oriented approach in system structuring and modeling1 was used as the strategy for defining the model ...
    ... 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 heat depression analysis ...
    ... system. The system offers safe data archiving for complex data models as this one, as well as all procedures for data manipulation. The use of SQL as a standard query language for data manipulation secures the openness of the hybrid system INVENTS for a connection with different environments. Figure ...

  • Numerical Models of Debris Flows with Entrainment Analysis-Case Studies from the Republic of Serbia

    Jelka Krušić , Biljana Abolmasov, Miloš Marjanović (2021)
    The results of material entrainment analysis in RAMMS debris flow software, as well as numerical models of final flow heights for two case studies from the Republic of Serbia are presented. Both of debris flow cases started with initial sliding of huge volume block, prolonging to behave as flowing process. Results of the analysis showed that entrainment material affects final results of transportation model, runout distance, deposition area and volume of debris flow. In both cases entrainment volume is very ...
    tecišta, zadržavanje nanosa, RAMMS, validacija

  • The optimization of auxiliary machinery in open-cast lignite mines: a case study of bulldozers

    Dragan Ignjatović, Predrag Jovančić, Stevan Đenadić, Ivan Janković, Ivica Ristović (2019)
    One of the most important prerequisites for the successful operation of the open-cast lignite mine is to carry out all the auxiliary works timely with the necessary quality. The most important and most commonly used auxiliary machines are bulldozers. Engaging time of bulldozers use is in direct relation with the coefficients of the time and capacity utilization of the continuous system for the excavation of coal and tailings, which indicates their importance. More than 100 bulldozers have been hired ...
    open-cast coal mine, auxiliary works, bulldozers, optimization, availability
    ... average costs for strong and very strong dozers operating on open- cast lignite mine: e Average costs for strong dozers are 63.75 €/mh; e Average costs for very strong dozers are 95.12 €/mh. 288 Limiting costs based оп these уајџез аге defined for strong dozers at 70 C/mh and for уегу strong dozers ...
    ... Kolubara basin during ј1751 ten years of operation This diagram (Figure 7) is used for further analysis related to optimal replacement time. Lower limit of availability for dozer replacement is 0.80. This is limit value for linear correlation of time categories — time in operation, time of planned and ...
    ... and Occupational Safety” (TR 33039), “Developed new methods for diagnosis and examination mechanical structures” (TR 35040) and a part of the project “Research on possibility for AT (Advanced Technology) rockbolting application in mines for the purpose of increasing work safety and production efficiency” ...

  • Spatial distribution of major and trace elements in artificial lakes in Serbia: health risk indices and suitability of water for drinking and irrigation purposes

    Goran Marković, Aleksandar Ž. Kostić, Nebojša Đ. Pantelić, Radojka Maletić, Jana Štrbački, Jovan Cakić, Lazar Kaluđerović, Biljana P. Dojčinović, Angelo Maria Giuffrè, Jelena B. Popović-Djordjević (2023)
    Lakes and reservoirs are the main water resources for household, irrigation, and industrial use. Hence, it is necessary to control water pollution and have reliable information on water quality, which refers to its suitability for a particular purpose. The main objective of this study was to evaluate the suitability of water for drinking and irrigation purposes from ten artificial lakes on the territory of the Republic of Serbia. The physicochemical parameters were determined using standard analytical methods, whereas the ...
    Management, Monitoring, Policy and Law, Pollution, General Environmental Science, General Medicine

  • Projecting short to medium-term effects of carbon emissions trading on Serbia's GDP

    Boban Pavlović, Nikola Trtica (2024)
    This paper presents an approach to assess the short to medium-term effects of the Emissions Trading System (ETS), an economic and climate policy instrument aimed at reducing greenhouse gas emissions, on GDP from the expenditure side. The analysis focuses on Serbia’s electricity sector, which relies heavily on lignite-based pro duction dominated by state-owned enterprises. The obtained projections suggest that in the short term, the introduction of an ETS may lead to slower GDP growth compared to official forecasts. However, ...
    ETS, BDP - rashodni pristup, cene električne energije
    ... to introduce short-term carbon pricing and a middle to long-term ETS are necessary for each Western Balkan economy. The Action Plan for implementing the Sofia Declaration es- tablishes an indicative timeframe for aligning with the EU ETS or introducing other carbon pricing instruments by 2024 (Regional ...
    ... the case study, available historical data, projections from relevant institutions for the economy and energy sectors, and the period for which the analysis was conducted, the assumptions on which the approach for the case study is based are. 1. Revenue from the ETS will be utilized to promote ...
    ... by 2030. When defining input data for the projection of electricity consump- tion by end-users, finding specific elasticity values for electricity con- sumption in Serbian households is challenging due to limited publicly available studies. Previous studies for other countries indicate low electricity ...

  • Polyhedral characteristics of the cosalite-type crystal structures

    Sabina Kovač, Predrag Dabić, Aleksandar Kremenović, Aleksandar Pačevski, Ljiljana Karanović, Marko V. Rodić, Martina Tribus (2019)
    kristalna struktura, kozalit, poliedarske karakteristike

  • VENTEX: An Expert System for Mine Ventilation Systems Analysis

    Ranka Stanković, Nikola Lilić, Ivan Obradović (1996)
    Analiza sistema za ventilaciju je komleksan proces, koji bazira na proračunu brojnih parametara, koji se odnose na: stanje mreže, provetrenost, stabilnost sistema, gubitke vazduha, klimatske uslove, gasno stanje, ugroženost od požara i opasne prašine. Navedeni problemi se uspešno rešavaju paketom SimVent, ali potpuno razumevanje i korišćenje dobijenih rezultata zahteva angažovanje iskusnog specijaliste iz oblasti ventilacije. Rešenje je nađeno u kreiranju ekspertnog sistema VENTEX, čija je baza znanja formalizacija ekspertskog znanja iz oblasti ventilacije rudnika. U radu je prikazana metodologija ...
    ekspertni sistem, ventilacija
    ... Измењено: 2023-10-14 04:20:47 VENTEX: An Expert System for Mine Ventilation Systems Analysis Ranka Stanković, Nikola Lilić, Ivan Obradović Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] VENTEX: An Expert System for Mine Ventilation Systems Analysis | Ranka Stanković ...
    ... ventilation systems analysis is the evaluation of the general ventilation state of the mine. An appropriate and reliable solution for this problem is vital for the safety of the working process in mines with underground exploitation. Contemporary mining theory already operates with a number ...
    ... interface and a working memory, but also a module for the interface with SimVent numerical routines, the simulation routines themselves, and a data base used by these routines /Fig. 3/. The main purpose of the user interface is to provide means for a successful dialogue, i.e. an exchange of ...

  • Models of Determining the Parameters of Rock Mass Oscillation Equation with Experimental and Mass Blastings

    Suzana Lutovac, Branko Gluščević, Rade Tokalić, Jelena Majstorović, Čedomir Beljić (2018)
    ... Minerals 2018, 8, 70 2 of 18 that this is the parameter which best defines danger from shock and damages it may cause. Due to that, adequate standards for the protection from shock are based on data that refer to oscillation velocity [2,3]. As the relation between the rock mass oscillation velocity ...
    ... . . , vN be the rock mass oscillation velocity values obtained for corresponding reduced distances R1, R2, . . . , RN. Proceeding from the equation for the rock mass oscillation velocity, given by the Equation (1) we can assume, that for pairs (Rm, vm) the following relations are valid: vm = K·Rm −n ...
    ... blasting conditions and geological characteristics of the rock mass, and it is determined based on trial blasting for a specific work environment. Thus, this paper offers analysis of the method for determination of parameters of the rock mass oscillation equation, which are conditioned by rock mass properties ...

  • Spatial and temporal variability of precipitation in Serbia for the period 1961-2020

    Boško Milanović, Phillip Schuster, Milan Radovanović, Vesna Ristić Vakanjac, Shristoph Schneider (2017)
    У овом раду анализиране су месечне, сезонске и годишње суме падавина у Србији за период 1961–2010. Географска ширина, дужина и надморска висина 421 падавинске станице и карактеристике терена у њиховом блиском окружењу (нагиб и аспект терена у радијусу од 10 км око станице) коришћене су за развој регресионог модела на основу којег је прорачуната просторна расподела падавина. Приказан је просторни распоред годишњих, јунских (максималне вредности за скоро све станице) и фебруарских (минималне вредности за скоро све станице) падавина. Годишње ...
    padavine, distribucija godišnjih padavina, distribucija mesečnih padavina, Republika Srbija

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

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

  • 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
    ... carried out. For that purpose, the optimal conditions for the practical application in mortar and concrete production are defined. Tests related to the use of waste slag as a partial replacement for cement in the production of mortars and concrete are performed in accordance with certain standards, and the ...
    ... determined in accordance with standard EN 1015-10, on the specimens used for testing of mechanical strengths, e.g., on the prisms with dimensions 40 mm × 40 mm × 160 mm. Flexural strength was determined in accordance with standards EN 196-1, EN 1015-11 and was tested on the prisms with dimensions 40 mm ...
    ... 003. Superplasticizer was used for the improvement of the consistency of fresh concrete and the same quantity was added to all concrete mixtures. Mix proportions of concrete mixtures for 1 m3 of concrete are given in Table 3. Table 3. Mix proportion of concrete mixtures for 1 m3 of concrete. Component ...

  • An Efficient Class of Iterative Root-Finding Methods with Applications

    Dejan Ćebić, Nebojša Ralević (2021)

  • Spatial assessment of the areas sensitive to degradation in the rural area of the municipality Čukarica

    Natalija Momirović, Ratko Kadović, Veljko Perović, Miloš Marjanović, Aleksandar Baumgertel (2019)
    Nature and Landscape Conservation, Soil Science, Agronomy and Crop Science, Water Science and Technology

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

    Mirjana Banković, Dejan Stevanović, Milica Pešić, Aleksandra Tomašević, Ljiljana Kolonja (2018)
    Главни циљ контроле квалитета угља у рудницима лигнита је снабдевање термоелектрана угљем чији квалитет мора да се креће унутар одређених квалитативних ограничења. Карактеристике угља могу да утичу на ефикасност, поузданост и расположивост како котла тако и јединица за контролу емисије. У овом раду аутори су презентовали интегрисану симулацију рударског процеса као нови приступ у истраживању променљивости калоричне вредности угља приликом експлоатације комплексног лежишта лигнита. Резултати таквог приступа омогућавају драгоцен увид у перформансе континуалног рударског система у смислу контроле променљивости ...
    mine planning, variability of coal quality, simulation, coal blending

  • The subthermal potential of karstic groundwater of Kučaj–Beljanica region in Serbia estimated by the multivariate analysis

    Ljiljana Vasić, Dragana Ž. Živojinovic, Vladana Rajaković-Ognjanović, Huang Fen, Cao Jianhua (2021)
    Earth-Surface Processes, Geology, Pollution, Soil Science, Water Science and Technology, Environmental Chemistry, Global and Planetary Change