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Упит dcterms_subject_txt:marginal costs,

125 items

  • Development of an integrated model for open-pit-mine discontinuous haulage system optimization

    Miodrag Čelebić, Dragoljub Bajić, Sanja Bajić, Mirjana Banković, Duško Torbica, Aleksej Milošević , Dejan Stevanović (2024)
    equipment selection, mine mechanization, expert judgment, linguistic variables, MCDM, FAHP

  • Sustainable Modularity Approach to Facilities Development Based on Geothermal Energy Potential

    Nataša Čuković-Ignjatović, Ana Vranješ, Dušan Ignjatović, Dejan Milenić, Olivera Krunić (2021)
    The study presented in this paper assessed the multidisciplinary approach of geothermal potential in the area of the most southeastern part of the Pannonian basin, focused on resources utilization. This study aims to present a method for the cascade use of geothermal energy as a source of thermal energy for space heating and cooling and as a resource for balneological purposes. Two particular sites were selected—one in a natural environment; the other within a small settlement. Geothermal resources come ...
    геотермална енергија, Панонски басен, геотермална каскада, енергетска ефикасност, бањски центри, балнеологија, биоклиматска архитектура, стратегије пасивног дизајнирања, модуларни објекти
    ... modules allowed for phase execution, which sig- nificantly reduced initial construction costs. This is even more important when the local community is funding or co-funding the facility since the median value of overall costs for 20 proposals included in the study (excluding the land, which is already publicly ...
    ... expected. The modular approach presented in this paper addresses the issues of flexibility in the use of certain features and mitigation of operating costs for periods of lower demand. High seasonal sensitivity implies that the facility may operate only during the summer, so providing thermal comfort and ...
    ... ed as being significantly seasonal, meaning that with this concept all of them may remain open to the public year round with optimized operational costs. The modular approach, which visually and functionally brings together nearly isolated open-door and enclosed spaces (Figure 11), provides a layout ...

  • Fragmentation Size Prediction of Blasted Material Using a Specialized Software for Drilling and Blasting

    Stefan Milanović, Nikola Simić, Lazar Kričak, Milanka Negovanović, Nikola Đokić, Miljan Gomilanović (2024)
    Design and optimizing the drilling and blasting parameters, should fill the requirements for the capacity, fragmentation size, and technical characteristics of loading and transport equipment, and enable a safe work at the open pit. Besides mentioned, it also achieves the minimal impact on the environment of the open pit and decreases the negative effects on the environment, especially in the blast vibration and flyrock. To obtain the best possible blasting effects and consider all the factors, a specialized software is ...
    optimization, O-Pitblast, drilling, blasting, fragmentation size

  • 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

  • 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 ...
    sucker rod pump, fluid production, mechanical extraction methods,, Prosper, QROD, RODSTAR
    ... Proper selection of each individual element ofthe 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 ...
    ... plunger and cylinder diameters. Larger plunger and cylinder dimensions allow for longer intervals between maintenance and reduced operational costs, especially in the exploitation of shallow oil wells and it is not a good choice in gassy wells. [1,3] Insert Pumps The primary difference between ...
    ... Electric motors are very suitable for driving rod pumps because the entire cycle is automated. The drawbacks include relatively high installation costs and electricity consumption when lifting a relatively high volume of fluid. There are also specific characteristics of electric motor operation ...

  • Mitigating hydrate formation in onshore gas wells: A case study on optimization techniques and prevention

    Milica Ješić, Bojan Martinović, Stefan Stančić, Miroslav Crnogorac, Dušan Danilović (2023)
    Gas wells, particularly those situated onshore, play a vital role in the global energy sector by supplying a significant portion of natural gas. However, operational challenges, notably gas hydrate formation, pose substantial issues, leading to complications such as flowline blockages and unexpected well shutdowns. Gas hydrates, crystalline structures resembling ice, ...
    Gas Well, Gas Hydrate Formation, Well Modeling, Well Performance Optimization, Choke Position Adjustments, Methanol Injection

  • A Fuzzy Expert Model for Availability Evaluation

    Dejan Ivezić, Miloš Tanasijević, Predrag Jovančić, Radiša Đurić (2019)
    Each technical system within itself carries the great potential danger of possible occurrence of failure and damages. Mining machines are characteristic by great investment values, costs of unplanned shutdowns, complex working conditions, and environment and workers hazards. Systematic monitoring of the mining machinery is of great importance for the management of the mining companies. Availability is the overall concept of quality of service. Includes information regard to operating state, an idle state, a standby state and shut down. The ...
    raspoloživost, ekspertski sistem, fazi teorija, buldozeri
    ... carries the great potential danger of possible occurrence of failure and damages. Mining machines are characteristic by great investment values, costs of unplanned shutdowns, complex working conditions, and environment and workers hazards. Systematic monitoring of the mining machinery is of great ...
    ... evidential reasoning. Reliability Engineering and System Safety, 47(2), 103-118, 1995. [9] Ignjatovic, D., Jovancic, P., Optimization of operation and costs of auxiliary mechanization in order to increase the utilization of overburden and coal systems on the open cast mines of Public Enterprise "Elek ...

  • Application of the Fuzzy Model in the Evaluation and Selection of Hydraulic Excavators on Open-Pit Lignite Mine

    Stevan Đenadić, Miloš Tanasijević, Vladimir Milisavljević, Dragan Ignjatović, Predrag Jovančić (2021)
    The production of lignite in large open-pit mines is mainly performed with continuously operating equipment, where bucket-wheel excavators, bucket-chain excavators, belt conveyors, and spreaders are the basic machines. Smaller machines, usually of discontinuous operating nature, are commonly categorized as auxiliary machines. This paper presents the research related to the analysis of auxiliary machine parameters with the case study for a hydraulic excavator. The purpose of the analysis was to develop a model of rating quality of service of the ...
    Fuzzy theory, hydraulic excavator, selection, quality of service, asset management

  • Self-Engineering: Possibilities for Maintenance Operations in the Mining Machines Industry

    Steven Manders, Milorad Pantelić, Vladimir Milisavljević, Alberto Martinetti (2021)
    Self-engineering is a relatively new branch of knowledge that aims to understand how systems could “autonomously” re-configure or repair themselves without the intervention of the operators. A direct field of application is within the maintenance spectrum. Having systems or machines capable of self-detecting or even self-repairing could represent a game-changer, in capital asset fields such as the mining industry in particular. This paper aims to investigate the possible benefits and challenges of self-engineering / self-maintenance concerning mining machines, specifically bucket-wheel ...
    self-engineering, self-maintenance, maintenance operations, mining industry, bucket-wheel excavator, gearbox revitalization

  • Application of VIКOR method in the selection of an optimal splution of excavation “Borska Reka” ore deposit

    Sanja Bajić, Dragoljub Bajić, Branko Glušćević, Radmila Gaćina (2023)

  • Indeksi kontrole održavanja i korišćenja rotornog bagera

    Jovana Mitrović, Predrag Jovančić, Dragan Ignjatović, Stevan Đenadić, Filip Miletić (2023)
    Razvoj površinske eksploatacije se u velikom stepenu zasniva na svestranoj mehanizaciji rudarskih radova. Kako bi se zadovoljili potrebni kapaciteti, neophodna je primena savremene mehanizacije, velikih kapaciteta i pouzdanosti u radu. Naime, sa stepenom povećanja mehanizovanosti radova smanjuje se broj zaposlenih radnika, povećava produktivnost rada, smanjuju troškovi po jedinici proizvoda, a samim tim i povećava ekonomičnost površinske eksploatacije. Predmet istraživanja su rotorni bageri SRs 1200 koji predstavljaju samohodne mašine kontinuiranog dejstva namenjene za otkopavanje jalovine i korisne supstance na površinskim ...
    rudarstvo, rotorni bager, indeksi održavanja, indeksi korišćenja, TOPSIS

  • Development of integrated fuzzy model for mine management optimization

    Miodrag Čelebić, Sanja Bajić, Dragoljub Bajić, Dejan Stevanović, Duško Torbica, Vladimir Malbašić (2023)
    fuzzy logika, višekriterijumsko odlučivanje, ocenjivanje eksperata
    ... decision making, Introduction. Mine management optimization, and thus the importance of mining. activity planning, stem from the fact that production costs are measured * Corresponding, author. DOT:10.7546/ CRABS.2023.09.12 1413 in enormous amounts of money. This industry hires a large number of ...
    ... are largely found at large depths, causing; certain mine management problems that need to be examined. On the one hand, this includes excavation costs, extractable ore reserves, and ore depletion during; the course of mining. On the other hand, a safe mining: technology and a healthy work environment ...

  • Application of stochastic models for mine planning and coal quality control

    Dejan Stevanović, Božo Kolonja, Ranka Stanković, Dinko Knežević, Mirjana Banković (2014)
    ... plant must include minimizing: (1) the expected (mean) costs of coal blending and (2) the variance of coal blending costs. The cost objective function includes coal purchasing cost, ash disposal cost, sulfur removal cost, and fuel switch- ing costs. Chance constraints include several risk measures, such ...
    ... selecting a proper pile size to meet an acceptable level of variability. The optimal size must be defined tak- ing into account capital and operational costs. The key message of stemming from the results in this paper is that the simulation model provides a useful decision support tool to compare opera- ...

  • Legal framework for recultivation of degraded areas caused by mining exploitation

    Radmila Gaćina (2023)
    Prilikom površinske i podzemne eksploatacije uglja eksploatacioni sistemi oštećuju veće ili manje površine zemljišta. Iskustva pokazuju da su oštećenja zemljišta znatno veća kod površinske eksploatacije, gde je prostora degradiran ne samo u konturi rudnika i okoline, već se promene takođe dešavaju u prirodnom okruženju. U članku su predstavljeni rezultati studije zakonskih okvira rekultivacije u nekim zemljama sveta i u Srbiji. Praktično iskustvo rekultivacije pokazalo je da iskorišćenje i devastacija tokom rudarske aktivnosti predstavljaju opasnost ne samo za pogođena ...
    rekultivacija, melioracija, otkopavanje uglja, zakonska regulativa
    ... ministry responsible for environmental protection. If liquidation or bankruptcy proceedings are opened against the holder of the exploitation, the costs of rehabilitation and recultivation of the land on which the exploitation was carried out will be covered as a matter of priority from the liquidation ...
    ... number of problems, especially in the phase of creating and approving project and technical documentation, because it requires more time and higher costs. Consequently, the field of reclamation should be regulated uniformly by the Mining Law, which would avoid unnecessary administration and would ...

  • Application of machine learning for diagnosing the operation of a deep well pump in oil production

    Maja Trikić (2024)
    This paper will thoroughly examine how machine learning can improve the diagnosis of deep well pumps by analyzing the role and function of the pumps, dynamograms, sensor technologies, and diagnostic methods.Our analysis will provide insights into modern techniques and approaches for enhancing the performance and reliability of oil production systems, targeting cost reduction and increased operational efficiency.
    deep well pump, dynamograms, machine learning, diagnostics of operating coditions,Random Forest, XGBoost
    ... that prevail in deep wells. Their ability to maintain a continuous flow of oil from depth to the surface directly impacts production efficiency and costs. Therefore, continuous monitoring and improvement of their performance is essential to ensure optimal operation and minimize failures.This paper ...
    ... surface, where it is further processed. The efficiency of their operation directly affects the amount of oil extracted and overall operational costs, making their analysis and optimization a key aspect of the industrial process.Furthermore, we will discuss dynamograms in deep well pump systems ...
    ... analysis, machine learning can help optimize maintenance scheduling, directing resources where they are most needed, thereby reducing downtime and costs. 4. Automatic calibration and adaptation Machine learning models can automatically adjust system parameters based on new data. For example, if ...

  • Life Cycle Assessment of Individual Wood Biomass Heating Systems in Households

    Boban Pavlović, Dejan Ivezić, Marija Živković (2020)
    The use of solid fuels (wood biomass and coal) for heating of households continues to be common practice within European countries. Solid fuel combustion in households contributes more than 46% to total emissions of fine particulate matter. In this study, a life-cycle assessment (LCA) of firewood-based and pellet-based heating systems is performed. These two systems represent two different types of individual wood biomass heating systems. In the case of the firewood-based heating systems, it is analyzed a typical stove ...
    Grejanje, Analiza životnog ciklusa, Drvna biomasa, Individualni sistemi grejanja
    ... energy consumption of HSs is calculated by using data from the available Energy Agency of the Republic of Serbia’s (AERS) report on the comparative costs of housing heating in the annual report [17]. The AERS’s methodology is based on the analysis of a typical flat of 60 m2 that is heated to 20°C for ...
    ... ch/site/assets/uploads/2018/05/SYR_AR5_FINAL_full _wcover.pdf (accessed 30 Sep. 2020). [17] AERS, Energy Agency of the Republic of Serbia (2018). Energy costs for heating residential space, AERS, Belgrade. (available only in Serbian)http://aers.rs/g/vesti/file/Dokumenti/grejanje.pdf (accessed 10 Sept. 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

  • Cutting Resistance Laboratory Testing Methodology for Underwater Coal Mining

    Vladimir Čebašek, Veljko Rupar, Stevan Đenadić, Filip Miletić (2021)
    Geology,Geotechnical Engineering and Engineering Geology
    ... bucket-wheel type UCW-450 has been in operation for over 20 years. Based on analyzing the bucket-wheel dredger performance, productivity, maintenance costs, and reliability, a rational decision was made: to rehabilitate the most essential parts of the dredge, including the bucket wheel and the gearbox. ...
    ... bucket-wheel type UCW-450 has been in operation for over 20 years. Based on analyzing the bucket-wheel dredger performance, productivity, maintenance costs, and reliability, a rational decision was made: to rehabilitate the most essential parts of the dredge, including the bucket wheel and the gearbox. ...
    ... a large difference in cutting resistance, which was especially manifested in the drop of bucket-wheel excavator productivity, increased maintenance costs, and lower reliability. According to the previous findings, there was a need to rehabilitate the most essential parts of the dredger, bucket wheel ...

  • A fuzzy-based decision support model for effectiveness evaluation - a case study of examination of bulldozers

    Miloš Tanasijević, Predrag Jovančić, Dejan Ivezić, Uglješa Bugarić, Radiša Đurić (2019)
    Effectiveness evaluation is one of the basic components of engineering asset management and maintenance engineering in general. Effectiveness is an overall concept representing a measurement of quality of service level for the analyzed engineering system. This concept contains a series of partial indicators relating to time in operation and time for maintenance activities, as well as functional properties of the system. This article describes the analysis and structuring of partial indicators, as well as the development of a model ...
    Efikasnost, Fazi zaključivanje, Prikupljanje podataka, Buldozer

  • Развој модела употребног квалитета помоћне механизације на површинским коповима лигнита

    Драгица Јагодић Крунић (2021)
    Тренутно стање помоћне механизације на површинским коповима лигнита је незадовољавајуће узроковано пре свега старошћу и неблаговременом заменом машима услед чега је расположивост недовољна а трошкови експлоатације и одржавања високи. Тренутно стање и захтеви који се постављају пред ове машине указују на неопходност оптимизације процеса управљања помоћном механизацијом. Одређивање оптималног времена замене и преосталих могућности је најодговорнији управљачки задатак који треба да буде заснован на свеобухватном сагледавању економских, техничких и других узрочно последичних веза. Са економског аспекта гледано треба одржавати ...
    помоћна механизација, употребни квалитет, ефективност, расположивост, сигурност функционисања, ризик, трошкови животног циклуса, фази логика, Монте Карло метода
    ... власништва (costs of ownership); Co – оперативни трошкови (operational costs), (Cf+Clo+Cpcm); Cf – трошкови погонске енергије (costs of fuel); Clo – трошкови мазива, уља, филтера итд. (costs of lubricants, oils, filters, etc.); Cpcm – трошкови превентивног и корективног одржавања (costs of preventive ...
    ... где су дате следеће ознаке за трошкове: Cow – трошкови власништва (costs of ownership), Co – оперативни трошкови (operational costs) , Cop – трошкови руковаоца (operator costs); Ct – укупни трошкови (total costs). Трошкови власништва Власник машине, у овом случају рударска ...
    ... Cgsp – бруто продајна цена (gross selling price) , Cc – трошкови комисије (commission costs) , Cmr – припремни трошкови (make-ready costs) , Ci – трошкови инфлације током периода власништва (inflation costs) , Crv – преостала вредност (residual value) . Вредност коју треба обновити кроз ...