Претрага
174 items
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Razvoj modela upravljanja cirkulacijom u postupku bušenja korišćenjem neuro fazi sistema zaključivanja
Seyed Ali S. Razeghi (2022)Gubitak isplake predstavlja nekontrolisano isticanje bušaćeg fluida kroz formacije kao što su kaverne, pukotine, ili drugi slojevi. Tradicionalne metode procene gubitka isplake se zasnivaju na primeni seizmičkih podataka ili pronalasku „mesta“ gubitka isplake na osnovu raspoloživih podataka iz susednih bušotina. Međutim, ove metode procene nisu pouzdane.‘ U disertaciji je izvršena analiza i procena uticaja parametara bušenja, geoloških faktora, karakteristika formacije i fluida na gubitak isplake kao i na formiranje fraktura u formacijama. Uspostavljeni su modeli koji podrazumevaju proces obrade ...Seyed Ali S. Razeghi. Razvoj modela upravljanja cirkulacijom u postupku bušenja korišćenjem neuro fazi sistema zaključivanja, Beograd : [S. Razeghi], 2022 M70
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Sprega neuronskih mreža i numeričkih modela zadefinisanje sigurnih rastojanja kod razletanja komada pri miniranju
Saša S. Stojadinović (2013-09-16)Doktorska disertacija sa navedenim naslovom prezentuje rezultate istraživanjaproblema razletanja komada pri miniranjima. Cilj istraživanja bio je kreiranje opšteg iuniverzalno primenljivog modela za prognozu maksimalnih dometa razletelih komada idefinisanje sigurnih rastojanja. Kombinacijomterenskih istraživanja, numerikogmodeliranja balistikih trajektorija razletelih komada i adaptivne prirode neuronskihmreža definisan je koncept neuro-numerike sprege. Sprega je objedinila univerzalnuprimenljivost numerikog modela i sposobnost prilagoavanja neuronskih mrežalokalnim uslovima u opšti model za prognozu maksimalnih dometa razletelih komada.Za potrebe sprege, a kao integralni deo disertacije, razvijen je metod za odreivanjekoeficijenta ...Razletanje, miniranje, domet, sigurna rastojanja, numeriki modeli,neuronske mreže, sprega, verifikacijaSaša S. Stojadinović. "Sprega neuronskih mreža i numeričkih modela zadefinisanje sigurnih rastojanja kod razletanja komada pri miniranju" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2013-09-16)
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Određivanje teorijskog termičkog potencijala napuštenih naftnih i gasnih bušotina
Marija Ilić, Marija Živković, Dušan Danilović, Miroslav Crnogorac, Vesna Karović Maričić, Lola Tomić (2023)U Srbiji postoji oko 1.200 napuštenih naftnih i gasnih bušotina, koje imaju značajan potencijal za proizvodnju toplotne energije. Napuštene bušotine, u zavisnosti od lokacije gde se nalaze i termičkog potencija sa kojim raspolažu, se mogu koristiti za proizvodnju toplotne energije ili električne energije, ili za kombinovanu proizvodnju električne i toplotne energije. Toplotna enegija koja je proizvedena iz napuštenih bušotina dobija se korišćenjem geotermalne energije, pa se i električna i /ili toplotna energija koja bi se dobila korišćenjem takvih toplotnih izvora bilansira ...Marija Ilić, Marija Živković, Dušan Danilović, Miroslav Crnogorac, Vesna Karović Maričić, Lola Tomić. "Određivanje teorijskog termičkog potencijala napuštenih naftnih i gasnih bušotina" in Tehnika, Savez inženjera i tehničara Srbije (2023). https://doi.org/10.5937/tehnika2306667I М53
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Testing the energy value of different types of coal by the method of active thermography
In this paper, coal thermograms are presented and analyzed in order to determine their energy value. Two types of coal of different categories, brown and lignite, were selected for active thermographic imaging. The tested coal samples were processed before measurement so that they are similar in dimensions and have two plane-parallel smooth surfaces. The test samples were "primarily" heated under the same conditions and the process of their cooling was monitored by a thermal camera. "Then" they were cooled ...Stevan Đenadić, Ljubiša Tomić, Vesna Damnjanović, Predrag Jovančić, Dragutin Jovković. "Testing the energy value of different types of coal by the method of active thermography" in 9th International Scientific Conference on Defensive Technologies, Belgrade, Serbia, 15-16 October 2020, The Military Technical Institute (2020) М33
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Sentiment Analysis of Serbian Old Novels
In this paper we present first study of Sentiment Analysis (SA) of Serbian novels from the 1840-1920 period. The preparation of sentiment lexicon was based on three existing lexicons: NRC, AFFIN and Bing with additional extensive corrections. The first phase of dataset refinement included filtering the word that are not found in Serbian morphological dictionary and in second automatic POS tagging and lemma were manually corrected. The polarity lexicon was extracted and transformed into ontolex-lemon and published as initial ...Ranka Stanković, Miloš Košprdić, Milica Ikonić Nešić, Tijana Radović. "Sentiment Analysis of Serbian Old Novels" in Proceedings of the 2nd Workshop on Sentiment Analysis and Linguistic Linked Data, June 2022, Marseille, France, European Language Resources Association (2022) М33
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A new polymorph of Ba(AsO3OH): Synthesis, crystal structure and vibrational spectra
Tamara Đorđević, Ljiljana Karanović (2010)A new monoclinic polymorph of Ba(AsO3OH) was synthesized under hydrothermal conditions. It represents a previously unknown structure type. Its crystal structure was determined from a racemic twin using single-crystal X-ray diffraction data collected at 120 and 293 K [space group P21, a=7.2149(14)/7.2370(2), b=7.7028(15)/7.7133(2), c=21.7385(43)/21.8079(5) Å, β=95.95(3)/96.073(1)1, V=1201.6(4)/1210.51(5) Å3, Z=12]. The crystal structure of P21-Ba(AsO3OH) has a layered character and is built up of four types of regularly alternating layers parallel to (0 0 1). Every AsO3OH tetrahedron is chelating to two Ba atoms and ...Ba(AsO3OH), хидротермална синтеза, структурна анализа монокристала, Раманска спектроскопија, инфрацрвена спектроскопија, водоничне везе, хидрогенарсенати земноалкалних металаTamara Đorđević, Ljiljana Karanović. "A new polymorph of Ba(AsO3OH): Synthesis, crystal structure and vibrational spectra" in Journal of Solid State Chemistry, Elsevier BV (2010). https://doi.org/10.1016/j.jssc.2010.09.027 М22
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Method validation and geochemical modelling of chromium speciation in natural waters
The study focuses on validating reference methods such as ICP-OES and ICP-MS for detecting ultratrace levels of chromium in groundwater, where concentrations are typically very low. Additionally, it verifies a hyphenated technique, IC-ICP-MS, for determining naturally occurring Cr(VI) in tested waters. The validation process involved various chromium analysis variants, including isotopes 52Cr and 53Cr in ICP-MS and IC-ICP-MS techniques, along with specific emission lines in the ICPOES technique. Statistical data processing revealed that the achieved limits of quantification for ...шестовалентни хром, ИЦ-ИЦП-МС, технике са цртицама, геохемијско моделирање, анализа спецификација, валидација методеPiotr Rusiniak, Katarzyna Wątor, Ewa Kmiecik, Vesna Ristić Vakanjac. "Method validation and geochemical modelling of chromium speciation in natural waters" in Scientific Reports, Springer Science and Business Media LLC (2024). https://doi.org/10.1038/s41598-024-77425-3 М21
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Development of a new system of solid ionic conductors based on multi-doped ceria for application in IT-SOFCs
Marija Stojmenović, Neda Nišić, Milan Zunić, Francesco Basoli, Jelena Gulicovki, Ivica Ristović, Milan Kragović (2022)Nanodimenzionisana multi-dopirana cerija sa sastavom Ce0.8Nd0.0025Sm0.0025Gd0.005Di0.095I0.095O2-d (CNSDI) kao perspektivni čvrsti jonski provodnik je dobijen modifikovanim glicin-nitratnim postupkom (MGNP) i samopropagirajućom reakcijom na sobnoj temperaturi (SPRT). Presovani peleti oba praha su sinterovani na 1550 °C za 2 h u vazdušnoj atmosferi. Dobijeni sinterovani uzorci su okarakterisani KSRPD, Raman spektroskopijom, FESEM, EDS i EIS metode. Uprkos visokoj temperaturi sinterovanja, KSRPD i FESEM analize uzorci su potvrdili odgovarajuće dimenzije zrna sa strukturom fluorita. Ukupna koncentracija uvedenih dodataka (k = 0,2) u strukturi ...Marija Stojmenović, Neda Nišić, Milan Zunić, Francesco Basoli, Jelena Gulicovki, Ivica Ristović, Milan Kragović. "Development of a new system of solid ionic conductors based on multi-doped ceria for application in IT-SOFCs" in Processing and Application of Ceramics, National Library of Serbia (2022). https://doi.org/10.2298/PAC2204391S М23
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Water in the Alluaudite Type-Compounds: Synthesis, Crystal Structure and Magnetic Properties of Co3(AsO4)0.5+x(HAsO4)2−x(H2AsO4)0.5+x[(H,□)0.5(H2O,H3O)0.5]2x+
In this study, a new cobalt arsenate belonging to the alluaudite supergroup compounds with the general formula of Co3(AsO4)0.5+x(HAsO4)2−x(H2AsO4)0.5+x[(H, )0.5(H2O,H3O)0.5]2x+ (denoted as CoAsAllu) was synthesized under hydrothermal conditions. Its crystal structure was determined by a room-temperature single-crystal X-ray diffraction analysis: space group C2/c, a = 11.6978(8), b = 12.5713(7), c = 6.7705(5) Å, b = 113.255(5)◦, V = 914.76(11) Å3, Z = 2 for As6H8Co6O25. It represents a new member of alluaudite-like protonated arsenates and the first alluaudite-like phase ...супергрупа алуаудита, арсенати прелазних метала, хидротермална синтеза, кристална структура, хидратисани хидрокси-арсенати, стехиометрија, магнетна својстваTamara Đorđević, Ljiljana Karanović, Marko Jagodič, Zvonko Jagličić. "Water in the Alluaudite Type-Compounds: Synthesis, Crystal Structure and Magnetic Properties of Co3(AsO4)0.5+x(HAsO4)2−x(H2AsO4)0.5+x[(H,□)0.5(H2O,H3O)0.5]2x+" in Minerals, MDPI AG (2021). https://doi.org/10.3390/min11121372 М22
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Distribution of Potentially Toxic Elements in the City of Zintan and Its Surroundings (Northwestern Libya) by Surface Soil Sampling
Boris Vakanjac, Zorana Naunović, Vesna Ristić Vakanjac, Tanita Đumić, Saša Bakrač, Jana Štrbački, Vuk Gajić, Taher Mohamed Alzarog (2023)The study area is the city of Zintan, in northwestern Libya, which has grown over the past 30 years. Its current population is roughly 30,000. Although the city is in part commercial, most of the population engages in agriculture and primarily grows cereal crops (wheat and barley). The demand of the growing city for agricultural products has increased, intensifying the use of fertilizers, pesticides, and insecticides. Consequently, concentrations of potentially toxic elements (PTE) in the soil have increased. To ...Boris Vakanjac, Zorana Naunović, Vesna Ristić Vakanjac, Tanita Đumić, Saša Bakrač, Jana Štrbački, Vuk Gajić, Taher Mohamed Alzarog. "Distribution of Potentially Toxic Elements in the City of Zintan and Its Surroundings (Northwestern Libya) by Surface Soil Sampling" in Minerals, MDPI AG (2023). https://doi.org/10.3390/min13081048 М22
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Sastav i teksture minerala FeO-Fe2O3-TiO2 sistema u vulkanskim stenama i porfirskim ležištima bakra Borske metalogenetske zone
Aleksandar Luković (2021)Proces obrazovanja minerala iz sistema FeO-Fe2O3-TiO2 u uzorcima vulkanskih stena i porfirskih orudnjenja borske zone prikazan kroz pojavu magnetita/hematita i njihovih alteracija. Minerali ove zone su ispitivani optičkim metodama (odbijena i propuštena svetlost), SEM-EDS/BSD, XRPD, LA-ICP-MS metodama. Rezultati ispitivanja su, pored glavnih Fe – Ti oksida, otkrili prisustvo ferijskog ilmenita u hornblenda andezitima I vulkanske faze kao i magnetita sa većim koncetracija Cr u zoni zlotske magnetne anomalije. Ispitivanje uzoraka iz bušotina porfirskih sistema borske zone otkriva postojanje nekoliko ...Aleksandar Luković. Sastav i teksture minerala FeO-Fe2O3-TiO2 sistema u vulkanskim stenama i porfirskim ležištima bakra Borske metalogenetske zone, Beograd : [A. Luković], 2021 M70
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Recent advances made by reaction experiments on melting of heavily metasomatized hydrous mantle
Dejan Prelević, Michael W. Förster, Stephan Buhre, Fatma Gülmez, Tobias Grützner, Yu Wang, Stephen F. Foley (2024)Mantle-derived magmas are traditionally assumed to originate by melting of an upper mantle consisting of uniform spinel- or garnet peridotite dominated by olivine. However, extensive studies of mantle-derived basalts suggest that the mantle is more mineralogically heterogeneous, so that the genesis of even the most common magmas requires consideration of mixed source regions within the mantle involving pyroxenites and hydrous minerals. We refer to these with the group term metasomes. However, most experimental studies on mantle melting have assumed ...Dejan Prelević, Michael W. Förster, Stephan Buhre, Fatma Gülmez, Tobias Grützner, Yu Wang, Stephen F. Foley. "Recent advances made by reaction experiments on melting of heavily metasomatized hydrous mantle" in Earth-Science Reviews (2024) М21а
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VENTEX: An Expert System for Mine Ventilation Systems Analysis
Analiza sistema za ventilaciju je komleksan proces, koji bazira na proračunu brojnih parametara, koji se odnose na: stanje mreže, provetrenost, stabilnost sistema, gubitke vazduha, klimatske uslove, gasno stanje, ugroženost od požara i opasne prašine. Navedeni problemi se uspešno rešavaju paketom SimVent, ali potpuno razumevanje i korišćenje dobijenih rezultata zahteva angažovanje iskusnog specijaliste iz oblasti ventilacije. Rešenje je nađeno u kreiranju ekspertnog sistema VENTEX, čija je baza znanja formalizacija ekspertskog znanja iz oblasti ventilacije rudnika. U radu je prikazana metodologija ...Ranka Stanković, Nikola Lilić, Ivan Obradović. "VENTEX: An Expert System for Mine Ventilation Systems Analysis" in YU Info '96 Brezovica, Društvo za informacione sisteme i računarske mreže (1996) М63
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Geološko-geofizički model dela Timočkog magmatskog kompleksa
Snežana M. Ignjatović (2014-06-30)Timočki magmatski kompleks (TMK) u geotektonskom smislu pripada KarpatoBalkanidimaistočne Srbije, koji su deo Tekijsko-Dakijske jedinice. TMK je nastaotokom kontinuirane vulkanske aktivnosti, koja je trajala oko deset miliona godina iodvijala se generalno u tri faze (Zimmerman et al., 2008, Kolb et al., 2013, Banješević,2006). Pomeranje vulkanskog fronta je išlo od istoka ka zapadu (von Quadt et al., 2002,2003, 2007). Ovaj kompleks pripada tetijskom evroazijskom metalogenetskom pojasu usvetu poznat po ležištima bakra i zlata (Janković, 1990).U doktorskoj disertaciji su prikazani rezultati ...Timočki magmatski kompleks, aeromagnetska istraživanja, gravimetrijskaistraživanja, 2D geološko-geofizički model, Valja Strž, magmatsko teloSnežana M. Ignjatović. "Geološko-geofizički model dela Timočkog magmatskog kompleksa" in Универзитет у Београду, Универзитет у Београду, Рударско-геолошки факултет (2014-06-30)