Претрага
547 items
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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... characterization of sphene based ceramics Jelena R. Pantić Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Синтеза и карактеризација керамике на бази сфена;Synthesis and characterization of sphene based ceramics | Jelena R. Pantić | Универзитет у Београду | 2015-07-10 ...
... ШКИ ФАКУЛТЕТ Јелена Р. Пантић СИНТЕЗА И КАРАКТЕРИЗАЦИЈА КЕРАМИКЕ НА БАЗИ СФЕНА докторска дисертација Београд, 2015 UNIVERSITY OF BELGRADE FACULTY OF MINING AND GEOLOGY Jelena R. Pantić SYNTHESIS AND ...
... верзије докторског рада Име и презиме аутора Јелена Пантић Број индекса 814/2010 Студијски програм Докторске акадамске студије Наслов рада | Синтеза и карактеризација керамике Ha бази сфена Ментор Проф. др. Александар Кременовић Потписани/а Јелена Пантић Изјављујем да је штампана верзија ...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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Challenges in using wastewater heat pumps in district heating systems
Dejan Ivezić, Marija Živković, Aleksandar Madžarević, Boban Pavlović, Dušan Danilović, Dimitrije Manić (2022)Decarbonization of district heating systems requires ensuring significant amounts of renewable energy available in the proximity of the district heating network. One of the promising solutions is the utilization of purified water from wastewater treatment plants by heat pumps. However, as a heat source, wastewater treatment plants are characterized by annual variability of the flow and temperature of purified water. The consequence is the variability of recoverable heat potential. In this paper, the effect of variability is analyzed for ...Dejan Ivezić, Marija Živković, Aleksandar Madžarević, Boban Pavlović, Dušan Danilović, Dimitrije Manić. "Challenges in using wastewater heat pumps in district heating systems" in 20th International Conference on Thermal Science and Engineering of Serbia, Niš, Serbia, October 18 – 21, 2022, Faculty of Mechanical Engineering in Niš (2022)
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Preliminary impact assessment of No2 emission from a heating plant on air pollution: case of Zemun, Serbia
The aim of this paper is to provide a preliminary evaluation of the impact caused by NO2 emissions from a heating plant on the local air quality. To model the spatial distribution of NO2 emissions from the heating plant, the AERMOD model was employed. The evaluation was conducted by analyzing and contrasting the simulated NO2 concentration from the heating plant with the overall NO2 concentration recorded at the nearest monitoring station over the entire heating season. The study focused ...Boban Pavlović, Uroš Pantelić, Marija Živković, Dejan Ivezić. "Preliminary impact assessment of No2 emission from a heating plant on air pollution: case of Zemun, Serbia" in Environmental Engineering and Management Journal (2023). https://doi.org/10.30638/eemj.2023.086
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Dynamic and Static Elastic Properties - Laboratory Investigations of Metamorphites of the "Vranjska Banja" Series
Metamorphites of the series “Vranjska banja” built predominantly of high crystallinity schist series, alternately layered double mica, gneiss, leptonite and micaschist. For the construction of the “Prvonek” dam were carried out laboratory investigations of dynamic and static elastic properties on micashist and gneiss samples in the perpendicular and parallel direction to the foliation. These investigations provided monitoring of the rock mass anisotropy properties and greater reliability of the design parameteres. As the design of mining and construction facilities becomes ...Jelena Majstorović, Bojan Dimitrijević, Suzana Lutovac, Snežana Savković, Miloš Gligorić. "Dynamic and Static Elastic Properties - Laboratory Investigations of Metamorphites of the "Vranjska Banja" Series" in XVI International Conference of the Open and Underwater Mining of Minerals, Scientific and technical union of mining, geology and metallurgy (2021)
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Mogućnost korelacije zatezne čvrstoće i dinamičkih svojstava belog venčačkog mermera
Zatezna čvrstoća se koristi pri dimenzionisanju komora (raspona između stubova), određivanju rezne sile na bagerima, izračunavanja efekata miniranja itd. Iskustvo je pokazalo da zatezna čvrstoća stena predstavlja 10-15% jednoosne č vrstoće na pritisak. Za preciznije određivane ovog parametra pristupa se laboratorijskim ispitivanjima, direktim ili indireknim metodama. U ovom radu su prikazana ispitivanja zatezne čvrstoće indirektnom metodom na uzorcima belog meremera ležišta Venčac. Pre utrđivanja zatezne čvrstoće, na svakom probnom telu izvršeno je merenje brzine longitudinalnih elastičnih talasa. Na osnovu ...Jelena Majstorović, Vladimir Čebašek, Veljko Rupar, Nebojša Gojković. "Mogućnost korelacije zatezne čvrstoće i dinamičkih svojstava belog venčačkog mermera" in Inženjerski problemi u mekim stenama - Druga konferencija regionalnih geotehničkih društav, Specijalizovana konferencija ISRM-aa, Друштво за геотехника на Македонија (2022)
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Challenges of Energy Transition in the Individual Heating Sector
U radu su prikazani rezultati istraživanja i ankete koja je sprovedena 2020. godine u domaćinstvima sa individualnim sistemima grejanja u Srbiji. Cilj ankete je bio da se sagleda stanje individualnih sistema grejanja, ali i stavovi vlasnika sistema vezano za energetsku tranziciju. Rezultati ukazuju na zastarelost sistema grejanja, nisku efikasnost, nedovoljna ulaganja u primenu mera energetske efikasnosti i nedostatak finansijskih sredstava za ulaganje u održivo grejanje. Osnovni prioriteti kod izbora načina grejanja jesu troškovi kupovine sistema i troškovi energenta, dok ...Boban Pavlović, Dejan Ivezić, Marija Živković. "Challenges of Energy Transition in the Individual Heating Sector" in Energija, ekonomija, ekologija, University Library in Kragujevac (2022). https://doi.org/10.46793/EEE22-1.17P
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Transition pathways of household heating in Serbia: Analysis based on an agent-based model
To explore pathways of the energy transition of household heating, an agent-based simulation model was developed for the case of the Serbian household sector. The model is focused on individual entities (households) with the objective to explore the effects of policy instruments on energy transition in households with individual heating systems. Empirically collected survey data were used as input for households’ attitudes towards sustainable heating. Simulations showed that the proposed instruments would lead to higher heating efficiency and less ...energetska tranzicija, modeliranje bazirano na agentima, sistemi grejanja, sektor domaćinstva, obnovljivi izvori energije, emisija CO2Boban Pavlović, Dejan Ivezić, Marija Živković. "Transition pathways of household heating in Serbia: Analysis based on an agent-based model" in Renewable and Sustainable Energy Reviews, Elsevier BV (2022). https://doi.org/10.1016/j.rser.2022.112506
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Integrated energy planning approach for accelerating energy transition of households
The success of energy transition planning depends on several influential and variable factors that need to be considered and tracked in modeling to support policymakers. Expert-based energy models are mainly developed following the assumptions of experts and, in most cases, a limited number of stakeholders. This top-down modeling approach will provide satisfactory results in centrally managed energy sectors (electricity generation and distribution, district heating, etc.), where further decisions could be projected relatively precisely. However, the same approach will not ...Energetsko planiranje, Integrisano energetsko modeliranje, Energetska tranzicija, Domaćinstva, Individualno grejanje, LEAPBoban Pavlović, Marija Živković, Dejan Ivezić. "Integrated energy planning approach for accelerating energy transition of households" in Energy Reports, Elsevier BV (2023). https://doi.org/10.1016/j.egyr.2023.11.016
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History of the development of the hydrodynamic model of the open pit mine “Drmno”, Serbia
With the creation of a hydrodynamic model, the need for it usually ceases until some next moment when the model needs to be updated and used for the set task for the necessary project documentation or dedicated studies. It is relatively rare that almost every year the model is improved and used for forecast calculations. The paper presents the basic characteristics and development of the hydrodynamic model of the open pit mine “Drmno” for 25 years. This open pit ...Dušan Polomčić, Jelena Ratković, Vesan Ristić Vakanjac. "History of the development of the hydrodynamic model of the open pit mine “Drmno”, Serbia" in National Conference with International Participation “GEOSCIENCES 2023”, Review of the Bulgarian Geological Society , Sofia : Bulgarian Geological Society (2023)
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The Impact Assessment of NO2 Emission from District Heating Plant on Local Air Quality, the Case of Zemun, Belgrade
The Belgrade district heating system relies on fossil fuels in heat production, where natural gas has the largest share of around 95% and fuel oil with around 4.4%. The Zemun heating plant is completely fueled with fuel oil. Currently, it is the largest plant that is not fueled with natural gas. The objective of this paper is to assess the impact of NO2 from the Zemun heating plant on local air quality by analyzing and comparing the concentration of ...NO2, Zagađenje vazduha, Kvalitet vazduh na lokalnom nivou, Model disperzije, AERMOD, Daljinsko grejanje, BeogradBoban Pavlović, Uroš Pantelić, Marija Živković, Dejan Ivezić. "The Impact Assessment of NO2 Emission from District Heating Plant on Local Air Quality, the Case of Zemun, Belgrade" in Conference on Sustainable Development of Energy, Water and Environment Systems, Dubrovnik, 10.10.-15.10.2021., University of Zagreb, Zagreb, Croatia; Instituto Superior Técnico, Lisbon, Portugal (2021)
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Effect of Properties of Working Fluids on the Efficiency of a Low-Temperature Organic Rankine Cycle
Decarbonization of all segments of energy systems, both on the supply and demand side, is one of the main goals of the energy transition. Electricity supply in the future will largely rely on generation from intermittent energy sources: wind and solar. Locally available, non-utilized alternative low-temperature energy sources as hydro-geothermal wells, and abounded oil and gas wells, have the potential to provide continual energy production over the year. Electricity generation from these energy sources is carried out with working ...Marija Živković, Aleksandar Mijatović, Dejan Ivezić, Boban Pavlović. "Effect of Properties of Working Fluids on the Efficiency of a Low-Temperature Organic Rankine Cycle" in The 21st International Conference on Thermal Science and Engineering of Serbia, Niš, Serbia, October 2024, University of Niš, Faculty of Mechanical Engineering in Niš (2024)
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Identification of the Best Available Renewable Energy Source for Electricity Production in Serbia
Around 2/3 of electricity production in Serbia originates from coal-fired thermal power plants. The most significant domestic coal deposits are lignite deposits, a type of low -quality coal that causes negative health, climate and environmental impacts during the combustion. To reduce those negative impacts on domestic electricity production and to promote environmental awareness, the Serbian Energy Sector Development Strategy and the National Action Plan for Use of Renewable Energy Sources indicate the plan for increasing the share of ...Strategija obnovljive energije, Održiva energija, Proizvodnja električne energije, Solarna energija, Biomasa, Hidroenergije, Energija vetra... Production in Serbia Boban Pavlović, Dejan Ivezić, Marija Živković Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] Identification of the Best Available Renewable Energy Source for Electricity Production in Serbia | Boban Pavlović, Dejan Ivezić, Marija Živković ...Boban Pavlović, Dejan Ivezić, Marija Živković. "Identification of the Best Available Renewable Energy Source for Electricity Production in Serbia" in Conference on Sustainable Development of Energy, Water and Environment Systems, Sarajevo, 28.6.-2.7.2020., Faculty of Mechanical Engineering and Naval Architecture, Zagreb (2020)
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Correlation of uniaxial compressive strength with the dynamic elastic modulus, p –wave velocity and s –wave velocity of different rock types
Knowing mechanical properties of rocks incorporated with ultrasonic waves velocities investigations provide a secure basis for mine modelling. Uniaxial compressive strength, dynamic elastic modulus and ultrasonic waves velocities are just some of the rock properties that indicate on presence of discontinuities, stratification and fissures of rocks. Determining the relationship of these rock properties testing the rock samples that are corresponding to different rock types extracted from different mineral deposits represents the core of this study. In this paper, we ...Jelena Majstorović, Miloš Gligorić, Suzana Lutovac, Milanka Negovanović, Luka Crnogorac. "Correlation of uniaxial compressive strength with the dynamic elastic modulus, p –wave velocity and s –wave velocity of different rock types" in Underground mining engineering, Рударско - геолошки факултет - Београд (2019)
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Estimating hydraulic parameters for the complex hydrodynamic models
Hydrodynamic models have usually been calibrated manually, by trial-and-error, with different values of hydraulic parameters and hydraulic characteristics of boundary conditions. This method of calibration and estimation of hydraulic parameters requires an extensive knowledge and experience of experts, but whether the resulting solution includes an optimal set of parameters still remains an open question. An optimization method founded upon the Gauss-Marquardt-Levenberg algorithm, along with PEST software based on that algorithm, introduces automation of model calibration with regularization, which substantially ...Dušan Polomčić, Dragoljub Bajić, Jelena Ratković, Bojan Hajdin. "Estimating hydraulic parameters for the complex hydrodynamic models" in Mining and Metallurgy Engineering Bor, Centre for Evaluation in Education and Science (CEON/CEES) (2018). https://doi.org/10.5937/mmeb1704029P
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Agent-based modeling as a support to an expert-based approach: Exploring individual heating systems transition
Expert-based energy scenarios are mainly developed following assumptions of experts and, in most cases, a limited number of stakeholders. Such an approach will provide satisfactory results in centrally managed energy sectors where further decisions could be envisaged relatively precisely (electricity production/distribution, district heating systems, etc.). The same approach will provide more uncertain outcomes of future energy structure in the household sector, where decisions related to consumption, selection of energy source, or application of specific technology are made by numerous ...Energetska tranzicija, Grejanje domaćinstava, Individualni sistemi grejanja, Energetsko planiranje, Integrisano energetsko planiranje, ABM, LEAP, SrbijaBoban Pavlović, Marija Živković, Dejan Ivezić. "Agent-based modeling as a support to an expert-based approach: Exploring individual heating systems transition" in South East European Conference on Sustainable Development of Energy, Water and Environment Systems 22 – 26 May 2022, Vlorë, Albania, Faculty of Mechanical Engineering and Naval Architecture, Zagreb (2022)
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Mathematical modeling to define catchment size and real evapotranspiration (case study: Andrića karst spring, Western Serbia)
Marina Čokorilo Ilić, Vesna Ristić Vakanjac, Dušan Polomčić, Dragoljub Bajić, Jelena Ratković, Bojan Hajdin (2018)Water resources in karst are extremely important sources of drinking water supply. The quality of groundwater formed in karst aquifers is generally high and in most cases only chlorination is required. However, from a hydrogeological perspective, these water resources are the least studied. Often only basic information is available on catchment size, groundwater reserves (dynamic and static, if any) and groundwater balance. Detailed hydrogeological investigations and long-term monitoring of karst spring discharges are needed to acquire such information. In ...Marina Čokorilo Ilić, Vesna Ristić Vakanjac, Dušan Polomčić, Dragoljub Bajić, Jelena Ratković, Bojan Hajdin. "Mathematical modeling to define catchment size and real evapotranspiration (case study: Andrića karst spring, Western Serbia)" in National Conference with international participation “Geosciences 2018”, Bulgarian Geological Sciety (2018)
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Град Охрид и Извештај о одржаним међународним конференцијама “SDEWES” и “BALWOIS” на Охриду (Македонија)
Представљан је рад SDEWES и BALWOIS конференције које су одржане нa Охриду. Дат је увид у рад и развој ових конференција, као и утисака и искустава учесника, представника Департмана за хидрогеологију, Рударско-Геолошког факултета. Акценат је стављен на секцију која се бави одрживим развојем водних ресурса, уз прилог о самом Охриду због његовог геолошког и хидрогеолошког значаја и чињенице да је познати туристички центар, седиште бројних конгреса и конференција из области вода, управо због своје интересантне историје и природних ...Драгољуб Бајић, Јелена Зарић, Весна Ристић Вакањац, Душан Поломчић, Марина Чокорило Илић. "Град Охрид и Извештај о одржаним међународним конференцијама “SDEWES” и “BALWOIS” на Охриду (Македонија)" in Записници Српског Геолошког Друштва за 2013. годину, Српско геолошко друштво (2014)
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Simulation of groundwater regime and quantification of groundwater balance by means of hydrodynamic analysis: Case of open-cast mine 'Jakovačka Kumša'
Hidrodinamička analiza, kao metodološki postupak, korišćena je za simulaciju režima i kvantifikaciju bilansa podzemnih voda na širem području Površinskog kopa „Jakovačka Kumša“. Istražni prostor obuhvata i deo beogradskog izvorišta podzemnih voda koje se nalazi u neposrednoj blizini površinskog kopa, u priobalju reke Save. Na površinskom kopu se vrši eksploatacija peska, koji se koristi kao građevinski materijal. Analizom i sintezom podataka koji se odnose na geološke i hidrogeološke ka-rakteristike područja, u radu je prikazan trodimenzionalni hidrogeološki model istražnog područja. Prevođenje ...hidrogeološki model, hidrodinamički model, izvorište podzemnih voda, numerička metoda konačnih razlika, ModflowDušan Polomčić, Dragoljub Bajić, Jelena Ratković, Đorđije Božović, Predrag Pajić. "Simulation of groundwater regime and quantification of groundwater balance by means of hydrodynamic analysis: Case of open-cast mine 'Jakovačka Kumša'" in Tehnika, Centre for Evaluation in Education and Science (CEON/CEES) (2019). https://doi.org/10.5937/tehnika1901056P
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Određivanje prostorne distribucije vrednosti hidrauličkih parametara izdani: primer površinskog kopa „Radljevo“
Najčešće se kalibracija hidrodinamičkih modela vršila manuelno - „probanjem“ sa različitim vrednostima hidrauličkih parametara i hidrauličkih karakteristika graničnih uslova. Ovakav način rada zahteva veliko znanje i iskustvo eksperta, pri čemu ostaje otvoreno pitanje da li dobijeno rešenje ima optimalan skup parametara. Primenom optimizacione metode, koja se zasniva na Gauss-Marquardt-Levenberg-ovom algoritmu, i PEST softvera, ...Dragoljub Bajić, Dušan Polomčić, Jelena Ratković, Predrag Pajić. "Određivanje prostorne distribucije vrednosti hidrauličkih parametara izdani: primer površinskog kopa „Radljevo“" in 9. Međunarodni simpozijum o upravljanju podzemnim resursima, Zaječar 2019., Megatrend Univerzitet, Fakultet za menadžment, Zaječar (2019)
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A contribution to the understanding of the discharge dynamics and water balance of the karst spring Gornji Dušnik (Suva Planina)
A sufficiently long time-series of daily discharges is needed to assess the discharge dynamics and calculate the water balance equation parameters of a spring (river source). The paper assumes that a catchment is gauged if a time-series of observations of at least 30 years is available, which is a rare case in Serbia. One-year monitoring is often set up to verify the reserves of a water source or spring intended for capture. Monitoring ceases after the final report is ...Aleksandar Tanasković, Vesna Ristić Vakanjac, Dušan Polomčić, Jelena Ratković. "A contribution to the understanding of the discharge dynamics and water balance of the karst spring Gornji Dušnik (Suva Planina)" in National Conference with International Participation “GEOSCIENCES 2023”, Review of the Bulgarian Geological Society, Sofia : Bulgarian Geological Society (2023)