Претрага
334 items
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Pećina Peštera kod Laznice - primer razvića speleoloških objekata u zoni raseda (rasednoj breči)
Mihajlo Mandić, Ana Mladenović (2022)Pećina Peštera se nalazi istočno od sela Laznica kod Žagubice. Iako lako pristupačna za posetioce i istraživače, do sada nije bila predmet detaljnijih istraživanja. Pominje se samo u prikazu arheološki interesantnih objekata okoline Žagubice, ali sa svedenim i uglavnom netačnim podacima o morfološkim karakteristikama. Speleološki značaj joj daje, pored relativno velikih dimenzija dvorane, njen razvoj u tektonski veoma oštećenoj zoni ukrštanja dva raseda što za posledicu ima potpunu dezintegraciju stenske mase u breču. Proces karstifikacije breče formira specifične morfološke ...Mihajlo Mandić, Ana Mladenović. "Pećina Peštera kod Laznice - primer razvića speleoloških objekata u zoni raseda (rasednoj breči)" in Zbornik 9. Simpozijuma o zaštiti karsta, Beograd : Akademski speleološko-alpinistički klub (2022)
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Flyrock Induced by Blasting in Surface Mining
Milanka Negovanović, Lazar Kričak, Snežana Ignjatović, Stefan Milanović, Jovan Marković, Nikola Simić, Rade Šarac (2022)Минирање представља и даље најефикаснији и најјефтинији начин експлоатације великих количина чврстих минералних сировина на површинским коповима. Енергија експлозије се користи за фрагментацију чврсте стенске масе до захтеване гранулације. Поред позитивних ефеката минирања, постоје и одређени нежељени ефекти сваког процеса минирања који се могу јавити, а то су: потреси тла, разлетање комада стене, ваздушни удари, отровни и загушљиви гасови и прашина. Разлетање комада стене је неконтролисано избацивање фрагмената одминиране стенске масе и представља један од главних извора материјалне ...Milanka Negovanović, Lazar Kričak, Snežana Ignjatović, Stefan Milanović, Jovan Marković, Nikola Simić, Rade Šarac. "Flyrock Induced by Blasting in Surface Mining" in 8th Balkan Mining Congress, Belgrade, September 28-30, 2022, Mining Institute Ltd, Belgrade (2022)
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The role of non-covalent intermolecular interactions on the diversity of crystal packing in supramolecular dihalopyridine–silver(i) nitrate complexes
Sunčica Roca, Lucija Hok, Robert Vianello, Mladen Borovina, Marijana Đaković, Ljiljana Karanović, Dražen Vikić-Topić, Zora Popović (2020)Six novel 1 : 2 complexes of silver(I) nitrate with 2,5-, 2,6- and 3,5-dihalopyridines (halo stands for chlorine and bromine) were prepared by the reaction of an aqueous solution of AgNO3 and the corresponding pyridine derivative in a water–alcohol solution. In spite of having analogous empirical formulae, they reveal intriguing structural differences, except [Ag(NO3)(2,5-Cl2py)2]n (1) and [Ag(NO3)(2,5-Br2py)2]n (4), which are isostructural. In contrast, [Ag(NO3)(3,5-Cl2py)2]2 (3) is dimeric, while its Br analogue [Ag(NO3)(3,5-Br2py)2]n (6) is polymeric in nature, being the ...Sunčica Roca, Lucija Hok, Robert Vianello, Mladen Borovina, Marijana Đaković, Ljiljana Karanović, Dražen Vikić-Topić, Zora Popović. "The role of non-covalent intermolecular interactions on the diversity of crystal packing in supramolecular dihalopyridine–silver(i) nitrate complexes" in CrystEngComm, Royal Society of Chemistry (RSC) (2020). https://doi.org/10.1039/D0CE01257B
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Effects of bentonite binder dosage on the properties of green limestone pellets
Vladimir Jovanović, Dinko Knežević, Živko Sekulić, Milan Kragović, Jovica Stojanović, Slavica Mihajlović, Dragana Nišić, Dragan Radulović, Branislav Ivošević, Milan Petrov (2016)This paper presents the results of tests carried out to determine how the dosage of bentonite added as binder, affects the properties of green pellets made of the limestone fines that originate from Lithothamnium limestone processing. Bentonite was added to limestone in different mass fractions (1, 2.5, 5 and 10%), whereas all the other parameters of the pelletizing process remained constant. The aim of pelletizing was to consolidate limestone fines and form mechanically stable pellets, provided that all the ...Vladimir Jovanović, Dinko Knežević, Živko Sekulić, Milan Kragović, Jovica Stojanović, Slavica Mihajlović, Dragana Nišić, Dragan Radulović, Branislav Ivošević, Milan Petrov. "Effects of bentonite binder dosage on the properties of green limestone pellets" in Chemical Industry, Beograd : National Library of Serbia (2016). https://doi.org/10.2298/HEMIND160210023J
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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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Optimizacija ugla nagiba generalne kosine unutrašnjeg odlagališta površinskog kopa Tamnava-Zapad
Formiranje geomehanički tabilnih unutrašnjih odlagališta otkrivke ima izuzetno značajnu ulogu pri projektovanju i planiranju razvoja površinskih kopova uglja sa aspekta preraspodele masa otkrivke, dinamike eksploatacije, ekoloških zahteva, rudarskih rizika i troškova. Uvećanje zavodnjenosti unutrašnjeg odlagališta otkrivke površinskog kopa Tamnava-Zapadno Polje, kao posledica globalnih klimatskih promena sa pojavom katastrofalnih obimnih padavina i velike poplave, dovelo je i do značajnih ali i trajnih promena geomehaničkih karakteristika materijala, umanjenja stabilnosti generalne kosine unutrašnjeg odlagališta i znatnog povećanja rudarskog rizika. Inovirane varijantne ...Natalija Pavlović, Branko Petrović, Tomislav Šubaranović, Ivan Janković. "Optimizacija ugla nagiba generalne kosine unutrašnjeg odlagališta površinskog kopa Tamnava-Zapad" in 15. Međunarodna konferencija o površinskoj eksploataciji OMC 2022, Zlatibor, 12.-15.10.2022., Jugoslovenski komitet za površinsku eksploataciju (2022)
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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... y-to create a new representation of the contour, according to equation (10). z(k) — (Xx — X-) + j(yk — y-) (10) A common boundary-based shape descriptor is the Fourier descriptor. With this representation, according to equation (10) and using the discrete Fourier transform (DET), it is possible ...
... difficulty of placing sensors inside the well, Gibbs and Neely developed a method for calculating the downhole dynamometric card using the damped wave equation. Unlike the surface card, the downhole card better reflects pump operating conditions, reducing the likelihood of errors in visual interpretation ...
... to smaller 48 values, meaning that the F1 score is high only if both precision and recall are high. The formula for the F1 score is shown in Equation (4). 2*precision*recall (4) Faiscor = — precision+recall Unlike binary classification, in multi-class classification, the F1 score is calculated ...Maja Trikić. Application of machine learning for diagnosing the operation of a deep well pump in oil production, 2024
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Groundwater gravitational circulation of Karst Veliko Vrelo and Malo Vrelo springs by isotope and the noble gas method: case study of the Beljanica Massif
Earth-Surface Processes, Geology, Pollution, Soil Science, Water Science and Technology, Environmental ChemistryLjiljana Vasić, Laszlo Palcsu, Huang Fen. "Groundwater gravitational circulation of Karst Veliko Vrelo and Malo Vrelo springs by isotope and the noble gas method: case study of the Beljanica Massif" in Environmental Earth Sciences, Springer Science and Business Media LLC (2019). https://doi.org/10.1007/s12665-019-8294-0
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Environmental Energy Security Indicators as Tools for Environmental Protection
Еколошка прихватљивост је постала незаменљив синтезни показатељ сваке валидне енергетске анализе у последње две-три деценије. Енергетска безбедност је у директној хармонији с еколошком прихватљивошћу кроз многе прописане политичке циљеве, економске користи, правне тековине итд. Индикатори еколошке сигурности представљају један од основних елемената за одређивање енергетске безбедности и снажне алате за усмеравање енергетског сектора ка одрживом развоју. У овом раду, анализа је била концентрисана на показатеље енергетске безбедности у области животне средине који се односе на сектор природног гаса у ...енергетска безбедност, еколошки енергетски индикатори, заштита животне средине, еколошка прихватљивост... consumption. The table 6 present energy produced by natural gas consumption. This table also shows the amount of CO2 emitted using a carbon dioxide (equation 1) emission factor related to the natural gas consumption. It should be noted that this partial indicator does not look at the total absolute value ...
... factor can be determined as: 𝒌𝑪𝑶𝟐 = 𝟑. 𝟔𝟕 ∙ 𝒈𝒄𝑯 (1) where: gc is mass fraction of fuel carbon in fuel, 3.67 is stoichiometric coefficient, H - thermal power of fuel (MJ / kg). The CO2 emission factors per unit of ...Aleksandar Madžarević, Dejan Ivezić, Marija Živković , Miloš Tansijević. "Environmental Energy Security Indicators as Tools for Environmental Protection" in Mining and Environmental Protection-MEP 2019, University of Belgrade, Faculty of Mining and Geology (2019)
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Determining the Groundwater Balance and Radius of Influence Using Hydrodynamic Modeling: the Case Study of the Groundwater Source “Šumice” (Kikinda, Serbia)
A groundwater flow model was developed to simulate groundwater extraction from the public water supply source of the City of Kikinda. The hydrodynamic model includes the municipal groundwater source of Kikinda (Šumice and the Jezero Well), but also an extended area where there are groundwater sources that provide water supply to three factories: (MSK, TM and LŽT - Kikinda). Hydrodynamic modeling, based on the numerical method of finite differences will show the groundwater balance of the sources in the ...... Assuming Darcian unsteady-state three-dimensional flow and based on the major hypotheses of this method (linear form of the sink term in the mass transfer equation and negligible order of magnitude of dispersion effects), the particle tracking method for the determination of the radius of influence ...Dušan Polomčić, Dragoljub Bajić, Jelena Zarić. "Determining the Groundwater Balance and Radius of Influence Using Hydrodynamic Modeling: the Case Study of the Groundwater Source “Šumice” (Kikinda, Serbia)" in Journal of Sustainable Development of Energy, Water and Environment Systems (2015). https://doi.org/10.13044/j.sdewes.2015.03.0017
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Rock excavation methods in urban areas
Stefan Milanović, Lazar Kričak, Milanka Negovanović, Nikola Simić, Jovan Marković, Nikola Đokić (2023)Povećan obim građevinskih radova, koji podrazumevaju izgradnju novih stambenih i poslovnih objekata, hotela, garaža, tržnih centara i slično, sve je češći u urbanim sredinama. Ovakvi radovi sve više dolaze u kontakt sa različitom vrstom problema prilikom izgradnje, kao jedan od tih problema izdvajamo pojavu čvrste stenske mase prilikom otkopavanja na lokacijama izgradnje budućih objekata predviđenih građevinskim projektom. Prilikom izgradnje objekata tj. dela objekta koji podrazumeva podzemne prostorije nekog objekta, potrebno je vršiti iskop materijala na lokaciji, međutim taj materijal ...Stefan Milanović, Lazar Kričak, Milanka Negovanović, Nikola Simić, Jovan Marković, Nikola Đokić. "Rock excavation methods in urban areas" in Podzemni radovi, Beograd : Rudarsko-geološki fakultet (2023). https://doi.org/10.5937/podrad2342047m
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Просторна анализа епикарста у оквиру карстног система источног дела Суве планине
Епикарст представља највиши део стенске масе који је изложен карстификацији, при чему су главне карактеристике епикарста акумулирање подземне воде и стварање услова за формирање концентрисаних токова у подини ове зоне. У досадашњој пракси истраживања епикарста углавном су коришћене индиректне методе: даљинска детекција, анализа хидрограма карстних врела, хидрохемијске и изотопске анализе, па чак и опити трасирања, док је са друге стране јако мали број истраживача изучавао епикарст директним теренским истраживањима. У раду je приказана иновирана методологија истраживања епикарста, која користи ...Бранислав Петровић, Зоран Стевановић, Вељко Мариновић, Снежана Игњатовић. "Просторна анализа епикарста у оквиру карстног система источног дела Суве планине" in XVI српски симпозијум о хидрогеологији са међународним учешћем, Универзитет у Београду, Рударско-геолошки факултет (2022)
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Age of the Jurassic hemipelagic sediments from the Ljubiš area (Zlatibor Mt., SW Serbia)
Nikita Bragin, Nevenka Đerić (2020)... represented by various co loured radiolarites with intercalated mass transport deposits and turbidites in the upper part and dated by radiolarians and fora minifers (RADOIĆIĆ et al., 2009). According to GAWLICK et al. (2017) the mass transport deposits in the upper part of the Gonje Formation ( ...
... Bathonian-Oxfordian. The new biostratigraphic data clearly show the onset of tectonic motion in the Middle Jurassic, documented by the presence of mass trans- port deposits intercalated in the radiolarite successions. This suggests a Middle Jurassic onset of ophiolite obduction which triggered the ...
... visible at the surface. A geological column of the section is shown in Fig. 4. The section begins with a twometre thick unit consisting of calcareous mass transport deposits and turbidites intercalated with darkgrey radiolarites (GAWLICK et al., 2017) (Unit 1). Five metres of dark greenish- grey ...Nikita Bragin, Nevenka Đerić. "Age of the Jurassic hemipelagic sediments from the Ljubiš area (Zlatibor Mt., SW Serbia)" in Geologia Croatica, Croatian Geological Survey (2020). https://doi.org/10.4154/gc.2020.11
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Definition of groundwater genesis and circulation conditions of the complex hydrogeological karst system Mlava–Belosavac–Belosavac-2 (eastern Serbia)
Ljiljana Vasić, Saša Milanović, Zoran Stevanović, Laszlo Palcsu. "Definition of groundwater genesis and circulation conditions of the complex hydrogeological karst system Mlava–Belosavac–Belosavac-2 (eastern Serbia)" in Carbonates and Evaporites, Springer Science and Business Media LLC (2020). https://doi.org/10.1007/s13146-020-00550-3
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The Importance of Geotechnical Investigations for the Construction of Transfer Station „Prelići“ on Landfill in Cacak – Serbia
For the purpose of the facilities construction within the transfer station „Prelici“ in Cacak, specific geotechnical investigations were carried out based on which the technological project with the facilities schedule was developed. Significant deviations in relation to the presented results were determined during earthworks, so the additional geotechnical investigation works were carried out. Since the new investigation works have determined a different cross section of the terrain, it was proposed to move the planned facilities which led to the ...... number of waste) and qualitative prevention (avoiding and reducing of harmful effects). Basically, quantitative prevention means: reducing the total mass of municipal waste and finding ways to recycle secondary raw materials from municipal waste (Rakic, Milovanovic & Jakovljevic, 2011). In this regard ...
... equipment into the urban industrial environment. In addition, an analysis of the available waste composition data and their comparison with the total mass of waste with data from different parts of the world and the average data for Serbia. 4. ANALYSIS OF GEOTECHNICAL CONDITIONS FOR THE CONSTRUCTION ...
... view of achieving national goals, the level of recycling increases and obtains the necessary raw material for the work of the recycling industry. The mass and volume of the final disposed municipal waste are reduced, and therefore the operating costs. From the aspect of local self-government, the way ...Dragoslav Rakić, Irena Basarić, Jovana Janković, Tina Đurić. "The Importance of Geotechnical Investigations for the Construction of Transfer Station „Prelići“ on Landfill in Cacak – Serbia" in 17th International waste management and landfill symposium, Proceedings SARDINIA 2019, CISA Publisher (2019)
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Дефинисање геотехничких параметара еолских седимената земуснког платоа на основу лабораторијских и теренских SPT испитивања
Ђорђе Крзман (2024)Циљ овог рада је био да се одреде геотехничке караткеристике предметног терена што представља полазну основу за рационално пројектовање и градњу. Истражним бушењем утврђено је да предметни терен изграђују четри лесна хоризонта и три слоја погребене земље до дубине од 22-23 m. Лабораторијским испитивањем добијени су ефективни параметри смичуће чврстоће, где се кохезија најчешће креће између c’=14 и 18 kPa, а угао унутрашњег трења f'= 25 - 30 °. Теренска SPT испитивањем уз коришћење прихваћених корелација у геотехничкој пракси ...... yellowish-gray in color, it contains carbonate concretions of size 0.5-1cm, sometimes up to 10cm, which in the lower part make up 10-50% of the total mass. BW2s (97,91 / kb 'G G+ 0 Lr '0 9+ 0 Gp /S i+ } Sr :/ 8L +L oc :0 gv +0 Gk E' 6e Z+ | Gb '6 9 < < Z6 '9 bE +| < Z6 '9 ...
... the veins, and in the lower parts concretions. Colors yellowish to light brown, with tubular macropores about 2 mm wide, rarely fissured, hard in mass. When it is soaked, it tears off along the cracks. Sensitive to supplementary wetting. FIOTPEBEHA 3EMJbA HPYyTA: ne6rbuHe 0.5-2m, jaBrba ce waeh)y ...
... porosity, subordinately contains cracks along wWhich it separates. Dark-red and brown in color, enriched with iron and manganese hydroxides, hard in mass, very friable when wet. TIECOMJJI - III nJECHVI XOPM3OHT: ne6rbuHe 3-5M, aanexe uaMehy koTa 80-87, ca npocnojuva necka viaeh)y 86-87MHB. Jlecovna ...Ђорђе Крзман. Дефинисање геотехничких параметара еолских седимената земуснког платоа на основу лабораторијских и теренских SPT испитивања, 2024
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Punctuated, episodic magmatism and mineralization of the Rogozna skarn-hosted Au-Zn-Pb-Cu deposits revealed through high-precision U-Pb zircon geochronology
The subvolcanic regions of magmatic centers are commonly associated with alteration, mineralization, and economic ore deposits, however the duration and frequency of mineralizing pulses within the overall lifespan of these centers can be poorly defined. Therefore, models for the formation of mineral systems require more highprecision geochronology data to refine their evolutionary models. Rogozna Mountain and its eponymous magmatic complex, located in SW Serbia, hosts multiple base metal deposits associated with variable rock types and structural expressions and serves as a natural laboratory to ...Skarnovska mineralizacija, Magmatsko-hidrothermalni sistemi, Subvulcanske intruzije, geohronologija na cirkonima, CA-ID-TIMSSean P. Gaynor, Milorad D. Antić, Vladica Cvetković, Kristina Šarić, Urs Schaltegger. "Punctuated, episodic magmatism and mineralization of the Rogozna skarn-hosted Au-Zn-Pb-Cu deposits revealed through high-precision U-Pb zircon geochronology" in Ore Geology Reviews, Elsevier (2023). https://doi.org/https://doi.org/10.1016/j.oregeorev.2023.105775
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Evaluation of the effects of wastewater heat pump integration into district heating systems by simulation
Dejan Ivezić, Marija Živković, Dimitrije Manić, Aleksandar Madžarević, Boban Pavlović, Dušan Danilović (2023)The integration of wastewater heat pumps (using purified water) in district heating systems is analyzed in this paper. The simulation procedure is proposed to analyze the impacts of stochasticity of purified water temperature and flow to heat pump integration and operation. The analysis includes calculation of the daily and seasonal coefficient of performance, as well as fossil fuel savings and CO2 emission reduction due to wastewater heat pump use. The proposed procedure is implemented for the case study in ...Dejan Ivezić, Marija Živković, Dimitrije Manić, Aleksandar Madžarević, Boban Pavlović, Dušan Danilović. "Evaluation of the effects of wastewater heat pump integration into district heating systems by simulation" in Thermal Science, National Library of Serbia (2023). https://doi.org/10.2298/TSCI220813168I
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Actual contamination of the Danube and Sava rivers at Belgrade (2013)
Milan Antonijević, Marija Arsović, Josef Cáslavský, Vesna Cvetković, Predrag Dabić, Mladen Franko, Gordana Ilić, Milena Ivanovic, Nevena Ivanović, Milica Kosovac, Dragana Medić, Slobodan Najdanović, Milica Nikolić, Jovana Novaković, Tatjana Radovanović, Djurdjina Ranić, Bojan Šajatović, Gorica Špijunović, Ivana Stankov, Jelena Tošović, Polonca Trebse, Olivera Vasiljević, Jan Schwarzbauer (2014)rečni sistemi, stanje zagađenja, organski zagađivači, teški metali, skrining analize, non-target screening... inter-scan time of 0.1 s. Identification of the organic compounds. The EI+-mass spectra were compared with spectra of reference compounds from mass spectral databases (NIST/EPA/NIH Mass Spectral Library NIST05, Wiley/NBS Registry of Mass Spectral Data, 7th electronic version) and gas chromatographic retention ...
... injection into the gas chromatograph (GC), all of the extracts were reduced to a volume of 50 µL at room temperature. For the gas chroma- tographic–mass spectrometric (GC–MS) analyses, the extracts were reduced to a volume of 20 µL at room temperature. GC–MS analyses. GC–MS analysis was performed ...
... 45 μm and transferred to low-volume autosampler vials. HPLC–ESI-MS analyses. An Agilent 1100 HPLC system with an Agilent 6320 spherical ion trap mass spectrometer and electrospray ionization was used. The hormones were sepa- rated on a Phenomenex Kinetex C18 column, 100 Å, 150×3 mm, 2.6 μm particle ...Milan Antonijević, Marija Arsović, Josef Cáslavský, Vesna Cvetković, Predrag Dabić, Mladen Franko, Gordana Ilić, Milena Ivanovic, Nevena Ivanović, Milica Kosovac, Dragana Medić, Slobodan Najdanović, Milica Nikolić, Jovana Novaković, Tatjana Radovanović, Djurdjina Ranić, Bojan Šajatović, Gorica Špijunović, Ivana Stankov, Jelena Tošović, Polonca Trebse, Olivera Vasiljević, Jan Schwarzbauer. "Actual contamination of the Danube and Sava rivers at Belgrade (2013)" in Journal of the Serbian Chemical Society, National Library of Serbia (2014). https://doi.org/10.2298/JSC131105014A
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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 ...Лука Црногорац. Стратешко планирање функционалности подземних просторија моделом прогнозе деформација, Београд : [Л. Црногорац], 2023