Претрага
402 items
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Convective heat transfer in centrifugal pumps lifted wells: the case of South-Eastern Europe waxy wells
Electric submersible pumps (ESP) are applied in wells where additional energy is needed to ensure discharge of the fluid to the surface through the tubing. At the discharge side of the pump the fluid has bigger velocity, thus the pump induces a forced convection between the fluid and the tubing inner surface. Understanding of convective heat transfer in wellbores and analyses of influential parameters provides a possibility to optimise value of convective heat transfer coefficient in order to avoid ...Bojan Martinovic, Marija Živković, Branko Grubač. "Convective heat transfer in centrifugal pumps lifted wells: the case of South-Eastern Europe waxy wells" in International Journal of Oil, Gas and Coal Technology, Inderscience Publishers (2021). https://doi.org/10.1504/IJOGCT.2021.10043281
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Polimorfne promene materije nastale mlevenjem minerala
Milan Petrov, Ljubiša Andrić, Milena Kostović, Vladimir Jovanović, Dragan Radulović, Dejan Todorović, Branislav Ivošević (2023)U radu su prikazani rezultati istraživanja iz oblasti usitnjavanja, sakupljani duži niz godina, u Institutu za tehnologiju nuklearnih i drugih mineralnih sirovina. Poznato je da se područja sa frekfencijama preko 3·1011 do 3·1014 Hz nalaze u elektromagnetnom spektru infracrvenog i daleko infracrvenog emitovanog ili apsorbovanog zračenja. U radu su prikazani rezultati kada se materijal i kugle u mlinu nalaze na jednoj od pomenutih frekfencija, što nam omogućava da pomoću Borovog uslova frekfencija pristupimo izračunavanju emitovanih i apsorbovanih molarnih energija ...Milan Petrov, Ljubiša Andrić, Milena Kostović, Vladimir Jovanović, Dragan Radulović, Dejan Todorović, Branislav Ivošević. "Polimorfne promene materije nastale mlevenjem minerala" in X Kolokvijum o pripremi mineralnih sirovina univerzitet u beogradu, Rudarsko-geološki fakultet, 08.12.2023., Beograd : Univerzitet u Beogradu, Rudarsko-geološki fakultet (2023)
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Specific electrical conductivity in epikarst groundwater of the eastern Suva Planina mt.
Branislav Petrović (2022)The epikarst is a part of the karst outcrop that is located within the unsaturated zone and represents a complex point of contact and mixing of unconsolidated material from the terrain surface. The correct and complete perception of epikarst, its degree of development and the presence on the limestone terrain can be achieved with a multidisciplinary approach. The study area for the applied multidisciplinary research was the Eastern part of karst massif Suva Planina Mt. One important part of ...Branislav Petrović. "Specific electrical conductivity in epikarst groundwater of the eastern Suva Planina mt." in KARST 2022: "Importance, State of the Art, and Prospective of Utilization and Protection of Resources in Karst", Serbian Academy of Sciences and Arts (SASA) (2022)
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A new copper(II) arsenate, Na2Cu3(AsO3OH)4·4H2O containing discrete [Cu3O12]18− units: Synthesis, crystal structure and magnetic properties
Single crystals of the new disodium tricopper(II) tetrakis(hydrogenarsenate(V)) tetrahydrate, Na2Cu3(AsO3OH)4·4H2O were grown under hydrothermal conditions. The compound was characterized by room-temperature single-crystal X-ray diffraction, SEM-EDS analysis, Raman spectroscopy and magnetic susceptibility measurements. Na2Cu3(AsO3OH)4·4H2O represents a new layered structure-type [space group P21/c, a = 8.7089(17), b = 9.7452(19), c = 9.3353(19) Å, β = 92.63(3)°, V = 791.4(3) Å3, Z = 4]. The layers are normal to [100] and are composed of the isolated Cu3O12 units interconnected by AsO3OH coordination ...Na2Cu3(AsO3OH)4•4H2O, хидротермална синтеза, кристална структура, хидрирани хидрокси-арсенати, магнетна својстваTamara Đorđević, Ljiljana Karanović, Zvonko Jagličić. "A new copper(II) arsenate, Na2Cu3(AsO3OH)4·4H2O containing discrete [Cu3O12]18− units: Synthesis, crystal structure and magnetic properties" in Journal of Solid State Chemistry, Elsevier BV (2018). https://doi.org/10.1016/j.jssc.2018.05.024
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A contribution to the understanding of hydrochemical properties of thermomineral water on the L’dži locality (eastern part of North Macedonia)
Hristina Petrova, Katarzyna Wątor, Piotr Rusiniak, Boris Vakanjac, Vesna Ristić Vakanjac, Ewa Kmiecik (2023)Regarding the aspect of mineral, thermo-mineral, and thermal waters, on the territory of the Republic of North Macedonia, there are 65 registered locations, of which 8 are categorized as spas. This includes the Kežovica spa, also known as the Štipska spa. In the vicinity of Kežovica Spa is the thermo-mineral L’Dži spring with mineralization around 1.3 g/L and the water temperature at the time of sampling was 50.1 °C. Spring L’Dži is generated by a fault structure and is ...Hristina Petrova, Katarzyna Wątor, Piotr Rusiniak, Boris Vakanjac, Vesna Ristić Vakanjac, Ewa Kmiecik. "A contribution to the understanding of hydrochemical properties of thermomineral water on the L’dži locality (eastern part of North Macedonia)" in National Conference with International Participation “GEOSCIENCES 2023”, Review of the Bulgarian Geological Society, Sofia : Bulgarian Geological Society (2023)
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Fluid inclusion study in quartz of the Rudnik Pb-Zn-Cu-Ag skarn deposit, Serbia
Six types of fluid inclusions were identified in three growth zones of hydrothermal quartz from the Rudnik skarn deposit. In the core zone, primary two-phase fluid inclusions of high (type 1) and moderate salinity (type 2) homogenized to liquid between 350-430 °C and 340-420 °C, respectively. Raman analysis revealed that the vapour phases are a CO2-CH4 gas mixture, with a predominance of CO2. The core contains and dispersed vapour-rich fluid inclusions of low salinity (type 3) composed of CO2-CH4-H2S ...Stefan Petrović, Ronald J. Bakker, Vladica Cvetković, Rade Jelenković. "Fluid inclusion study in quartz of the Rudnik Pb-Zn-Cu-Ag skarn deposit, Serbia" in Mineral Resources in a Changing World-17th SGA Biennial Meeting, Zurich, between 28th August and 1st September 2023, Genéve : Society for Geology Applied to Mineral Deposits (2023)
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Geotehnički uslovi rekonstrukcije Zavičajnog muzeja u Jagodini
Milan Tokanović (2024)U radu su prikazana geotehnička istraživanja za potrebe rekonstrukcije Zavičajnog muzeja Jagodina.Zavičajni muzej u ulici Kneginje Milice br.82 u Jagodini, ima ozbiljna oštećenja pojedinih delova konstrukcije koja su nastala na objektu tokom više od 80 godina eksploatacije.Kako bi se trajno rešio problem dinamičke stabilnosti i statičke održivosti konstruktivnog sistema objekta,neophodno je bilo definisanje geotehničkih uslova u zoni interakcije prirodne sredine i konstrukcije predmetnog objekta.Izvedena su terenska i laboratorijska ispitivanja na osnovu kojih su dobijene geotehničke podloge. Na osnovu dobijenih geotehničkih podloga ...geotehnička istraživanja, Zavičajni muzej, temelji, fundiranje, nosivost, sleganje, istražne jame, laboratorijska geomehanička ispitivanja, Jagodina... mesecima, kada su temperature niske, relativna vlažnost vazduha je najveća, a tokom leta najniža. Sa prosečnom vlažnošću od 84%, decembar je najvlažniji, a jun sa 64%, najsušniji mesec. Najviše je padavina u maju (83mm), a najmanje u februaru (35mm). Vetrovi su veoma važan faktor jer izazivaju razlike ...
... Katedra za geotehniku temperatura iznosi od 11,2%C do 11,7%C, a najtopliji mesec je jul, sa prosečnom temperaturom od 22,2"C. Najhladniji mesec je januar, sa temperaturama od 0 do 8%C. Prodor hladnih vazdušnih masa sa severa i toplih sa juga uslovljavaju ovakav raspored temperature. U zimskim mesecima ...
... VIJALNI SEDIMENTI (dpr) Ovaj tip sedimenata starijeg kvartara ima veće rasprostranjenje, naročito sa desne strane Velike Morave. Sa izdvojenom nižom terasom ovi sedimenti bi pripali istom i nešto mlađem stadijumu razvoja rečnce doline, a razlikuju se uglavnom morfološki. Deluvijalno-proluvijalni ...Milan Tokanović. Geotehnički uslovi rekonstrukcije Zavičajnog muzeja u Jagodini, 2024
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The interaction of organoselenium trans-palladium(II) complexes toward small-biomolecules and CT-DNA
Serija organoselenijum trans-paladijum(II) kompleksa 1 (bis(2-(fenilselanilmetil)oksolan)dihloropaladijum(II)), 2 (bis(2-(fenilselanilmetil)oksan)dihloropaladijum(II)) i 3 (bis(2) ,2-dimetil-3-(fenilselanil)oksan)dihloropaladijum(II)) su korišćeni za ispitivanje reaktivnosti ovog specifičnog tipa kompleksa prema različitim bio-molekulima. Ovaj sistem je od posebnog interesa jer se jako malo zna o supstitucionim reakcijam organoselenijum paladijum(II) kompleksa sa trans konfiguracijom. Zamena koordinovanog hlorida sa serijom malih bio-molekula (l-Met, l-His, l-Cis, GSH i 5′-GMP) proučavana je pod uslovima pseudo-prvog reda kao funkcija koncentracije nukleofila i temperature korišćenjem tehnika zaustavljenog toka. Rezultati za proučavane komplekse ukazuju da ...Vera M. Divac, Aleksandar Mijatović, Marina D. Kostić, Jovana Bogojeski. "The interaction of organoselenium trans-palladium(II) complexes toward small-biomolecules and CT-DNA" in Inorganica Chimica Acta, Elsevier BV (2017). https://doi.org/10.1016/j.ica.2017.07.012
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3D modeling and monitoring of karst system as a base for its evaluation and utilization: a case study from eastern Serbia
Earth-Surface Processes, Geology, Pollution, Soil Science, Water Science and Technology, Environmental Chemistry, Global and Planetary ChangeSaša Milanović, Zoran Stevanović, Ljiljana Vasić, Vesna Ristić-Vakanjac. "3D modeling and monitoring of karst system as a base for its evaluation and utilization: a case study from eastern Serbia" in Environmental Earth Sciences, Springer Science and Business Media LLC (2013). https://doi.org/10.1007/s12665-013-2591-9
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Alpine thermal events in the central Serbo-Macedonian Massif (southeastern Serbia)
Milorad D. Antić, Alexandre Kounov, Branislav Trivić, Andreas Wetzel, Irena Peytcheva, Albrecht von Quadt (2015)Milorad D. Antić, Alexandre Kounov, Branislav Trivić, Andreas Wetzel, Irena Peytcheva, Albrecht von Quadt. "Alpine thermal events in the central Serbo-Macedonian Massif (southeastern Serbia)" in International Journal of Earth Sciences, Springer Science and Business Media LLC (2015). https://doi.org/10.1007/s00531-015-1266-z
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Threshold-induced correlations in the Random Field Ising Model
... Behavior of the Two-Dimensional Nonequilibrium Zero-Temperature Random Field Ising Model. Phys. Rev. Lett. 106, 175701 (2011). 10. Spasojević, D., Janićević, S. & Knežević, M. Avalanche Distributions in the Two-Dimensional Nonequilibrium Zero-Temperature Random Field Ising Model. Phys. Rev. E 84, 051119 ...
... two-dimensional nonequilibrium zero- temperature random-�eld Ising model. Phys. Rev. E 89, 012118 (2014). 34. Spasojević, D., Mijatović, S., Navas-Portella, V. & Vives, E. Crossover from three-dimensional to two-dimensional systems in the nonequilibrium zero-temperature random-�eld Ising model. Phys. Rev ...
... Behavior of the Two-Dimensional Nonequilibrium Zero-Temperature Random Field Ising Model. Phys. Rev. Lett. 106, 175701 (2011). 10. Spasojevi¢, D., Janicevic, S. & KnezZevi¢, M. Avalanche Distributions in the Two-Dimensional Nonequilibrium Zero-Temperature Random Field Ising Model. Phys. Rev. E 84, 051119 ...Sanja Janićević, Dragutin Jovković, Lasse Laurson, Đorđe Spasojević. "Threshold-induced correlations in the Random Field Ising Model" in Scientific Reports, Springer Science and Business Media LLC (2018). https://doi.org/10.1038/s41598-018-20759-6
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Geothermal potential, chemical characteristic and utilization of groundwater in Serbia
To collect and unify data about all geothermal resources in Serbia, a database was formed. The database allows us to perceive the geothermal resources of Serbia and their potential for utilization. Based on the data available in the geothermal database, the estimated temperatures of reservoirs, heat power, and geothermal energy utilization were calculated. The database contains 293 geothermal records (springs, boreholes) registered at 160 locations, with groundwater temperatures in the range between 20 and 111 °C. The maximum expected ...Geothermal database, Geothermal resources, Geothermal potential, Hydrochemistry, Hierarchical cluster analysis, SerbiaTanja Petrović Pantić, Katarina Atanasković Samolov, Jana Štrbački, Milan Tomić. "Geothermal potential, chemical characteristic and utilization of groundwater in Serbia" in Environmental Earth Sciences, Springer Link (2021). https://doi.org/https://doi.org/10.1007/s12665-021-09985-w
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Merenje u naftnom rudarstvu
Snežana Aleksandrović, Branko Leković (2020)Snežana Aleksandrović, Branko Leković. Merenje u naftnom rudarstvu, Beograd : Univerzitet u Beogradu, Rudarsko-geološki fakultet, 2020
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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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Unusually sluggish microemulsion system with water, toluene and a technical branched alkyl polyethoxylate
Marija Ilić, Franz-Hubert Haegel, Vesna Pavelkić, Snežana Zlatanović, Zoran Marković, Aleksandar Cvjetić (2015)Microemulsion systems with water, toluene and nonionic surfactants are interesting for application due to the excellent solvent properties of aromatic hydrocarbons. In this study, the pseudo-binary phase diagram (“fish-diagram”) of such a ternary system was investigated using a branched technical alkyl polyethoxylate. Lutensol ON 50 (i-C10E5) was considered a suitable surfactant. The system with technical branched i-C10E5 exhibits very long, and for compositions near optimum solubilization, i.e., the minimum content of surfactant needed for a bicontinuous microemulsion, extremely long ...микроемулзија, толуен, оксоалкохол етоксилат, термодинамичка стабилност, тернарни фазни дијаграми, дијаграми „fish“Marija Ilić, Franz-Hubert Haegel, Vesna Pavelkić, Snežana Zlatanović, Zoran Marković, Aleksandar Cvjetić. "Unusually sluggish microemulsion system with water, toluene and a technical branched alkyl polyethoxylate" in Chemical Industry and Chemical Engineering Quarterly (2015). https://doi.org/10.2298/CICEQ141012045I
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Hydrothermal Synthesized and Alkaline Activated Carbons Prepared from Glucose and Fructose—Detailed Characterization and Testing in Heavy Metals and Methylene Blue Removal
Sanja Krstić, Milan Kragović, Maja Pagnacco, Vladimir Dodevski, Branka Kaluđerović, Miloš Momčilović, Ivica Ristović, Marija Stojmenović (2018)glukoza, fruktoza, аktivni ugalj, hidrotermalni tretman, aktivacija hidroksida, teški metali, metilen plavo... boiling point of K is close to 750 ◦C (temperature of activation), it is possible that potassium remains in the activated carbon structure and changes it [60–62]. On the other side, the boiling points of the Li and Na are much higher than activation temperature, so the possibility of their entering into ...
... hydroxides (KOH, NaOH and LiOH) as activation agents. Chemical activation was performed by dry mixing of selected precursor and hydroxide at room temperature with the ratio 1:3. Subsequently, the mixed samples were activated in a horizontal tube furnace (Protherm Furnaces, model PTF 16/38/250, Ankara, ...
... obtained by this procedure were designated as AC@G–T–N2–t–XOH and AC@F–T–N2–t–XOH, where G and F are precursors, N2 is activation gas, T and t are temperature and time of activation while XOH represent activation agents (X = Li, Na, K). During activations the following yields were obtained: 6.0; 7.9 and ...Sanja Krstić, Milan Kragović, Maja Pagnacco, Vladimir Dodevski, Branka Kaluđerović, Miloš Momčilović, Ivica Ristović, Marija Stojmenović . "Hydrothermal Synthesized and Alkaline Activated Carbons Prepared from Glucose and Fructose—Detailed Characterization and Testing in Heavy Metals and Methylene Blue Removal" in Minerals, MDPI (2018)
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Uticaj raspadanja na stabilnost kosina u mekoj stenskoj masi
Anđela Despotov (2024)U radu je opisano ponašanje mekih stenskih masa koje su izložene porecesu raspadanja tokom određenog vremenskog perioda. Meke stenske predstavljaju kritične vrste stenskih masa pošto izazivaju različite probleme tokom izvođenja građevinskih radova. Meke stene mogu biti sedimentne stene, raspadnute metamorfne i magmatske stene. Odlikuju se niskim vrednostima čvrstoće, visokom deformabilnošću, visokom plastičnošću, podložne su dezintegraciji i fizičko-hemijskom raspadanju, odnosno ubrzanom dejstvu površinskog raspadanja usled atmosferskih uticaja.Za klasifikaciju mekih stenskih masa koriste se modifikovane verzije već postojećih klasifikacionih sistema. Jedan ...... 20-30m. Temperatura je takođe važan faktor, Jer može uticati na brzinu raspadanja (brzinu hemijskih reakcija). Ovo je ı razlog zašto se hemijsko raspadanje može očekivati u tropskim oblastima sa toplim i vlažnim periodima, a ne u polarnim ili planinskim oblastima sa niskom temperaturom i malom ...
... 1) Sa slike 8 se može videti da uglovi qi i q» predstavljaju uglove smičuće otpornosti za niske 1 visoke nivoe normalnih napona, gde je ugao Qr= Q+i i o= Q. Kohezija se takođe može predstaviti za niske i visoke nivoe napona (ci i c2). Slika 8. a) Model progresivnog raspadanja (omekšanja) laminiranog ...
... korenja biljaka. U slučaju temperaturnih promena postoje dnevne ı godišnje promene temperature, pri čemu dolazi do različitih odnosa linearnog i zapreminskog širenja kod različitih minerala, a dnevna kolebanja temperature imaju uticaj do par desetina centimetara. Do kakvih efekata će doći zavisi od ...Anđela Despotov. Uticaj raspadanja na stabilnost kosina u mekoj stenskoj masi, 2024
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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... 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 on a Finnigan Trace MS, ThermoQuest ...
... μm particle size (Core- shell type) at a temperature of 25 °C using an acetonitrile (ACN)/water mixture at a flow of 0.25 mL min-1 (t0: 40 % of ACN, t20: 90 % of ACN). Nitrogen was used as the nebulising gas at a pressure of 25 psi, drying gas (N2) temperature and flow were 350 °C and 10 L min-1, r ...
... approxi- mately 20 cm below the water surface nearby the river bank and bottled in pre-cleaned flasks. The sample material was stored in the dark at a temperature of approximately 4 °C. Before extraction and TOC determination, all water samples were filtered through pre-cleaned What- man GF/F filters (0.45 ...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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Influence of Post-Synthesis Treatments on the Properties of Brushite/Monetite Powders
Željko Radovanović, Lidija Radovanović, Aleksandar Kremenović, Đorđe Janaćković, Rada Petrović (2022)Dicalcium phosphate (DP) materials, of which brushite and monetite were the most known, have been intensively studied for several decades because of excellent resorptive and osteoconductive properties that can satisfy the requirements needed for various medical applications, such as bone cements, coatings of metallic implants and bone grafts ...Željko Radovanović, Lidija Radovanović, Aleksandar Kremenović, Đorđe Janaćković, Rada Petrović. "Influence of Post-Synthesis Treatments on the Properties of Brushite/Monetite Powders " in Second International Conference on Electron Microscopy of Nanostructures ELMINA 2022, August 22nd–26th, 2022, Belgrade, Serbia, Serbian Academy of Sciences and Arts Knez Mihailova 35, 11000 Belgrade, Serbia (2022)
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Micro- to nanoscale textures of gold in arsenopyrite and scorodite from the As-Au-Bi assemblage of Drenjak locality (Serbia)
Ivana Jelić, Janez Zavašnik, Marina Lazarov, Alena Zdravković, Sabina Kovač, Jovica Stojanović, Aleksandar Pačevski (2023)Arsenopyrite and pyrite are important carriers of Au that is present in the form of microscopic and “invisible” gold. Such gold can be expected to be released upon the process of oxidation of these sulfides. In studied gold mineralization at Drenjak, related to the granitoids of the Oligocene-Miocene Kopaonik Ore District, the main arsenopyrite-pyrite-(bismuthinite) sulfide assemblage was formed in the quartz bodies and partly replaced by scorodite (FeAsO4·2H2O) and Bi-arsenate. With only up to 5 ppm of gold recorded ...Ivana Jelić, Janez Zavašnik, Marina Lazarov, Alena Zdravković, Sabina Kovač, Jovica Stojanović, Aleksandar Pačevski. "Micro- to nanoscale textures of gold in arsenopyrite and scorodite from the As-Au-Bi assemblage of Drenjak locality (Serbia)" in Ore Geology Reviews, Elsevier BV (2023). https://doi.org/10.1016/j.oregeorev.2023.105711