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Упит dcterms_creator_txt:Zdravkov A.

1498 items

  • Integrated Stratigraphy of the Middle–Upper Jurassic of the Krížna Nappe, Tatra Mountains

    Renata Jach, Nevenka Đerić, Špela Goričan, Daniela Reháková (2014)
    carbon and oxygen isotopes, radiolarians, calcareous dinoflagellates, radiolarites, Krížna Nappe, West ern Carpathians, Tethys
    ... [wt%] +-Pk201O. + PR948 + Pk1808 radiolarian St om io sp ha er a mo lu cc an a m Co lo mi sp ha er a na gy i ua -— sa Sc hi zo sp ha er el la C o l o m i s p h a e r a pi en in en si s a < Pk35 A. radiolarian o mwp Zadnia Kopka Košcieliska section in the Western ...
    ... BHISSSBSEEE j sošBSSGčS Š <-Lb51 ŠŠEŠŠEEŠS·” zi III <—-Lb38 A. s*sqassgsoečge d446 BSSsaBSBESS Ha:FO:B:Bo-r:B Cume'Š_EB°E sžaRSŠsSsSBOVŠ s gm%š—„··· & S <-L183 A, HIRKEEE Kl —_u! A ŠES Š8 s 555 90 20 Š a ŠSE Š Š +—-L140 A Šš - <—-L58 A. B Sample | CaCO,{[wt%] Microfacies Calcareous din ...
    ... versus 6O is used routinely to assess a potential diagenetic imprint on the stable-isotope record (e.g., Banner and Hanson, 1990; Huck ef a/., 2013). A sig- nificant positive correlation between 8IO and 85C may suggest a diagenetic imprint. This is because of a simulta- neous decrease in both 6'5O ...

  • Analysis Of the Process Of Carbon Capture Utilization And Storage In Underground Reservoirs

    John Nyame (2024)
    The importance of mitigating the effects of global climate change has necessitated an in-depth exploration of innovative strategies to reduce carbon dioxide (CO2) emissions. Among these strategies, Carbon Capture, Utilization, and Storage (CCUS) has emerged as a promising and transformative solution. This master thesis delves into the diverse realm of CCUS processes, aiming to unravel the positives challenges, and opportunities within this dynamic field. The analysis begins with a systematic examination of carbon capture technologies, encompassing post-combustion, pre-combustion, and oxy-fuel combustion ...
    Carbon Capture, Utilization and Storage
    ... unit has a fluid knockout drum, a compressor, a cooler and a gas turbine driver. Again, the compressor train with its gas turbine drive was designed and installed as part of the much larger operations of preparing the whole field development. The 4 units cost around 79million USD. A highly deviated ...
    ... provided by a regenerable metal oxide catalyst [47]. For pre-combustion CO2 capture, chemical looping can be combined with IGCC to produce syngas as a valuable byproduct. These technologies use a metal oxide as an oxygen carrier to circulate oxygen between the air and fuel reactors. A challenge ...
    ... exergy difference between the inlet and outlet. Here, the power consumed in a pump is added to the calculation of the exergy loss for a pump. In contrast, the power produced in a turbine is subtracted from the exergy loss of a turbine Pump: AEX loss= n'(eXin-eXou)+W"p (11) Turbine: AEx loss ...

  • 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
    ... optical emission spectrometry (ICP-OES). A Perkin Elmer, Optima 4300 DV spectrometer equipped with an AS-93 plus autosampler was used with a sample flow 1.5 mL min-1 and a wet plasma aerosol. RESULTS AND DISCUSSION Since a major aim of this study was to provide a comprehensive view on the state of ...
    ... is becoming more and more relevant as a source of drink- ing water. Therefore, an appropriate water quality control is needed as a base for a sustainable usage of river water. Pollution of the aquatic environment caused by inorganic chemicals is con- sidered a major threat to aquatic organisms including ...
    ... means of a Van Veen grab from a depth of 1.20 m and at the third location (Kapetanija), from a depth of 3.50 m. Sediment samples from the two locations on the Danube River were taken from depths of 0.90 m (Batajnica) and 1.20 m (Vinča). The samples were kept in pre-cleaned vessels and stored at a temperature ...

  • A Description of Morphological Features of Serbian: a Revision using Feature System Declaration

    Cvetana Krstev, Ranka Stanković, Vitas Duško (2010)
    In this paper we discuss some well-known morphological descriptions used in various projects and applications (most notably MULTEXT-East and Unitex) and illustrate the encountered problems on Serbian. We have spotted four groups of problems: the lack of a value for an existing category, the lack of a category, the interdependence of values and categories lacking some description, and the lack of a support for some types of categories. At the same time, various descriptions often describe exactly the same ...
    Morphology, Lexicon, lexical database, Standards for LRs
    ... 03:28:09 A Description of Morphological Features of Serbian: a Revision using Feature System Declaration Cvetana Krstev, Ranka Stanković, Vitas Duško Дигитални репозиторијум Рударско-геолошког факултета Универзитета у Београду [ДР РГФ] A Description of Morphological Features of Serbian: a Revision ...
    ... Motivation Description of morphological features of a language is a prerequisite for many NLP applications. This description can be simple or complex depending both on a language and application in question. Considerable efforts in standardizing such a description were undertaken, but many applications ...
    ... problems on Serbian. We have spotted four groups of problems: the lack of a value for an existing category, the lack of a category, the interdependence of values and categories lacking some description, and the lack of a support for some types of categories. At the same time, various descriptions ...

  • ‘Blue-’ and ‘Brown-speckled’ pottery from Qalhât, the Sultanate of Oman (13–16th centuries): Comparison with traditional Omani 19–20 century productions

    Liliana Gianni, Hélène Renel, Aleksandar Kremenović, Philippe Colomban (2020)
    Representative ‘Blue speckled’ (13–16th centuries) and ‘Brown speckled’ (13–21st century) wares recovered from the excavations in Qalhât or collected around Bahlâ city (Sultanate of Oman) were characterized by XRPD, SEM-EDS, Raman/optical microspectroscopy, and thermal expansion. Minerals present in the body (quartz, augite and albite as major phases, calcite, dolomite, rutile, anatase, phosphate, hematite and magnetite as minor phases) were identified by XRPD and/or Raman spectroscopy. SEM-EDXS microanalysis was performed on the glazes in order to compare their composition, especially ...
    Firing, Glaze, Traditional ceramics, Provenance studies, Augite

  • Gate Road Support Deformation Forecasting Based on Multivariate Singular Spectrum Analysis and Fuzzy Time Series

    Luka Crnogorac, Rade Tokalić, Zoran Gligorić, Aleksandar Milutinović, Suzana Lutovac, Aleksandar Ganić (2021)
    Underground mining engineers and planners in our country are faced with extremely difficult working conditions and a continuous shortage of money. Production disruptions are frequent and can sometimes last more than a week. During this time, gate road support is additionally exposed to rock stress and the result is its progressive deformation and the loss of functionality of gate roads. In such an environment, it is necessary to develop a low-cost methodology to maintain a gate road support system. ...
    deformacije podgrade, lasersko skeniranje, višekanalna singularna spektralna analiza, prognoza, klasterisanje fuzzy vremenskih serija
    ... can be defined as a triplet (a, b, c). The corresponding membership function is defined as [24]: µA(∆v) =  0, ∆v < a ∆v−a b−a , a ≤ ∆v ≤ b c−∆v c−b , b ≤ ∆v ≤ c 0, ∆v > c , (21) Step 2: determine a fuzzy observation of displacement. Triangular fuzzy number O(t) =(a(t), b(t), c(t)) is ...
    ... linguistic variable. It can be defined as a triplet (a, b, c). The corresponding membership function is defined as [24]: 0, Av <a Av—a ac Step 2: determine a fuzzy observation of displacement. Triangular fuzzy number O(f) =(a(t), b(t), c(t)) is also used to represent ...
    ... [20-22]. A fuzzy set A of AViyx.n is defined as follows: Av Av Ad a — faldou) | fal 2) 4 falAbmn) Avi, Avi2 Aomn (15) where f4 is the membership function of A, and f4: AV — [0,1]. The symbol “+” de- notes the union operator. Membership function represents the degree of membership of Av; in A, where ...

  • Infotheca (Q25460443) in Wikidata

    Ranka Stanković, Lazar Davidović (2021)
    Vikipodaci su baza znanja Zadužbine Vikimedija koja predstavlja zajednički izvor različitih vrsta podataka koje koriste ne samo drugi Vikipedijini projekti, već sve više i brojne aplikacije semantičkog veba. U ovom radu ćemo prezentovati primer integracije Vikipodataka sa digitalnim bibliotekama i eksternim sistemima, kao i mogućnost ubrzanja pripreme i unosa podataka na primeru radova iz časopisa za digitalnu humanistiku Infoteka.
    semantički veb,otvoreni povezani podaci, vikpodaci,Infoteka, metapodaci časopisa
    ... of an item cam be a literal itself, that is, a character string (for instance: the length of the Danube is 2860 km) or a reference to some other item (the capital of Serbia is Belgrade, for example). An item can be described by a string of statements, each of which provides a fact or a piece of data about ...
    ... assigned a persistent identifier, a positive integer with an upper-case Q as a prefix, known as QID. This makes translation of the basic information necessary for recognizing a topic covered by an item without favouring any language whatsoever, the aim being to ensure the uniqueness of meaning of a particular ...
    ... item is, thus, linked to a unique identifier (QID), the identifier is, in turn, linked to the item’s corresponding title and description, so as to remove any ambiguity. An identifier of a data item (QID) can, in addition to being linked to a title and a description, have a number of aliases and statements ...

  • Keyword Extraction from Parallel Abstracts of Scientific Publications

    Slobodan Beliga, Olivera Kitanović, Ranka Stanković, Sanda Martinčić-Ipšić (2017)
    ... deriva- tionally related forms of a word to a common base form. Lemmatization is the process of grouping together the inflected forms of a word so they can be ana- lyzed as a single item, identified by the word’s lemma, or a dictionary form. Stemming usually refers to a process that chops off the ends ...
    ... method (algorithm) with a human annotation, precision is calculated as the number of keywords in the inter- section of a set of keywords annotated by a human (A) and a set of keywords annotated using algorithm (B) divided by the number of keywords annotated using the algorithm: P = A ∩ B B . (1) The recall ...
    ... recall is calculated as the number of keywords in the intersection of a set of keywords annotated by a human and a set of keywords annotated using the algorithm divided by the number of keywords annotated by a human: R = A ∩ B A . (2) The F1 score is the harmonic mean of precision and recall, calculated ...

  • A Twitter Corpus and Lexicon for Abusive Speech Detection in Serbian

    Danka Jokić, Ranka Stanković, Cvetana Krstev, Branislava Šandrih (2021)
    Uvredljivi govor na društvenim medijima, uključujući psovke, pogrdni govor i govor mržnje, dostigao je nivo pandemije. Sistem koji bi bio u stanju da detektuje takve tekstove mogao bi da pomogne da internet i društveni mediji postanu bolji virtuelni prostor sa više poštovanja. Istraživanja i komercijalna primena u ovoj oblasti do sada su bili fokusirani uglavnom na engleski jezik. Ovaj rad predstavlja rad na izgradnji AbCoSER-a, prvog korpusa uvredljivog govora na srpskom jeziku. Korpus se sastoji od 6.436 ručno označenih ...
    uvredljivi jezik, govor mržnje, srpski, tviter, leksikon, korpus
    ... ( in t w i t t e r corpus ) : lopov f r a c : f requency [ a : atv i tkoFrequency ; r d f : va lue "17"^^ xsd : i n t ] . # usage examples as a t t e s t a t i o n s : lopov f r a c : a t t e s t a t i o n attes tat ion_1324567 ; at tes tat ion_1324567 a f r a c : At t e s ta t i on ; c i t o : hasCitedEnt ...
    ... corpname=user%2Franka%2Fatwitco> ; r d f s : comment " Immoral or c r i m i n a l a c t i v i t i e s " ; f r a c : l o c u s : locus_2415677 ; f r a c : quotat ion " s v i p o l i t i č a r i su l o p o v i . " . : locus_2415677 a : Occurrence ; n i f : beginIndex 19 ; n i f : endIndex 25 . and emoticons ...
    ... would be as dear to me as Croatia.”); 3. Derogatory speech (DS), a tweet is used to attack or humiliate an individual or group in a general sense, not in a way hate speech does (e.g. “@USER To je jedna budala, ne veruj mu ništa.”/“@USER He’s a fool, don’t believe him.”) 4. Other (OTH), abusive speech that ...

  • 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
    ... Dehghani-Sanij, A.; Kazemi, A.; Bordbar, N.; Farshchi, M.; Elmi, M.; Gharali, K.; Dusseault, M.B. A comprehensive study of geothermal heating and cooling systems. Sustain. Cities Soc. 2019, 44, 793–818. [CrossRef] 7. Soltani, M.; Kashkooli, F.M.; Dehghani-Sanij, A.; Nokhosteen, A.; Ahmadi-Joughi, A.; Gharali ...
    ... n. 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 ...
    ... n. 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 ...

  • A Tel Platform Blending Academic And Entrepreneurial Knowledge

    Ivan Obradović, Ranka Stanković, Jelena Prodanović, Olivera Kitanović (2013)
    ... resource is the Serbian wordnet. A wordnet is composed of synsets, or sets of synonymous words representing a concept, with basic semantic relations between them forming a semantic network. Each synset word or “literal” is denoted by a “literal string” followed by a “sense tag” which represents ...
    ... the BAEKTEL language support system are managed by a web application (VebRanka), a web service (wsQueryExpand.asmx), an executable Windows application derived from our multipurpose tool LeXimir [10], and a function library (LeXimirCore), a component of LeXimir. The language support system ...
    ... technology plays a significant supportive role, thus encompassing the OER/OCW initiative. Goodyear and Retalis argue that designing usable, effective interactive TEL environments, such as BAEKTEL, in an efficient affordable way "is a demanding task, which requires creativity and a significant ...

  • 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
    ... several grades (given as linguistic variables) [4]. TABLE I. QUESTIONNAIRE FOR ASSESSMENT OF AVAILABILITY INDICATORS A n a ly st N o . A v a il a b il it y in d ic a to r Questionnaire: Bulldozer Liebherr – Drmno Open Pit Mine Grade: Excellent Good Average Adequate Poor ...
    ... into one overall (A). Identification of obtained results, for their easier interpretation, is presented at the end, as well as their comparative analysis. A. Proposition The first step in the making of expert model for A assessment is describing linguistic variables related to A itself and to ...
    ... function (1) of A of machine Liebherr-D in form: μA(Lib-D) = (0, 0.11, 0.475, 0.475, 0.14) E. Final Exam and Identification Best-fit method [1] and proposed A fuzzy set give the final availability assessment for the machine Liebherr-D: ⸹1(A(Lib-D), exc) = [S5 j=1 (µj A(Lib-D) - µj exc)]0 ...

  • Photocatalytic Activity of the V2O5 Catalyst toward Selected Pharmaceuticals and Their Mixture: Influence of the Molecular Structure on the Efficiency of the Process

    Sanja J. Armaković, Aleksandra Jovanoski Kostić, Andrijana Bilić, Maria M. Savanović, Nataša Tomić, Aleksandar Kremenović, Maja Šćepanović, Mirjana Grujić-Brojčin, Jovana Ćirković, Stevan Armaković (2023)
    Due to the inability of conventional wastewater treatment procedures to remove organic pharmaceutical pollutants, active pharmaceutical components remain in wastewater and even reach tap water. In terms of pharmaceutical pollutants, the scientific community focuses on -blockers due to their extensive (over)usage and moderately high solubility. In this study, the photocatalytic activity of V2O5 was investigated through the degradation of nadolol (NAD), pindolol (PIN), metoprolol (MET), and their mixture under ultraviolet (UV) irradiation in water. For the preparation of V2O5, facile ...
    DFT analysis, metoprolol, nadolol, nanomaterial characterization, photocatalysis, pindolol, β-blocker
    ... Figure 5. These modes are unambiguously assigned to o-V>Os structure [30,31]: ~104(A„), 146(Bye / Bae), 198 (A„/Bx»), 285 (Biy / Bae), 306 (A), 406 (Ay), 483 (A„), 528 (A„), 701 (Biy/ B»g), and 995 cm_! (Ae). A good agreement of the position of the Raman mode at 995 cm ! with corresponding bulk ...
    ... sample, Figure 2. Refined unit cell parameter values (a = 11.506 (2), b = 4.3708 (6), c = 3.5627 (4) A,V = 179.17 (4) A9) are in good agreement with reference values reported in upper mentioned PDF card (a = 11.5100, b = 4.3690, c = 3.5630 A, V = 179.173 A3). The significant presence of an amorphous ...
    ... with the absence of ~840 cm ! mode in the spectra of the catalyst, reveals a good crystallinity of the V>»Os phase [30—32]. A broad feature at ~1020 cm !1 may be ascribed to surface VOx species on V>Os [33]. R a m a n in te ns it y 100 200 300 400 500 600 700 800 900 1000 1100 1200 Raman ...

  • Хазард од клизишта у Србији у 21. веку

    Biljana Abolmasov (2019)
    клизишта, хазард од клизишта, промене климе
    ... seeedes Zenic: 110.0 as S$ 8 8&8 S§ 8 8 $8 $$ FS 8B BS HF SF FF 8 3 8 $8 § &§ &$ 8 &€ 8 8 8 8 8 8 8 B = = = = = = = = = = = = = = = = a a a a a a a a a a a a a a a a >» 6. 10 > , 15. 30. 5. 2014. 5. 21. > > > > , _ . > > Intergovernmental Panel on Climate Changes) > > > [27]. 80 ������ ������ �� ...
    ... 17�21. J Norway. A. A. Balkema, Rotterdam, Netherlands. Vol. I. 53�74. [31] Kru�i� J., Andrejev K., Abolmasov B., Marjanovi� M. (2017). Prelimin of the Selanac debris flow modelling in RAMS � a case study. Proce Regional Symposium on Landslides in the Adriatic-Balkan Region � A Landslide Research ...
    ...  ��������� ����› (R � ). 21. > 69 > 7 v v [8], [9], [10], [11], [12], [13], > _ > > 1 > [8] > > > ») (1)R = H > >», A , Vv. - > > (Landslifie Hazard > - > > >, > i P(A x PINx S H (2) > > >. 1 A, N e > Ss >» > (Landslide )Susceptibility > > > > > > , > , > > > > > (Exposure > (> > ) > / > Vulnerability > > ...

  • Mineral and Thermal Waters of Serbia: Multivariate Statistical Approach to Hydrochemical Characterization

    Maja Todorović, Jana Štrbački, Marina Ćuk, Jakov Andrijašević, Jovana Šišović, Petar Papić (2016)

  • Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae

    Hans Peter Nytoft, Geir Kildahl-Andersen, Sofie Lindström, Frode Rise, Achim Bechtel, Danica Mitrović, Nataša Đoković, Dragana Životić, Ksenija A. Stojanović (2019)
    Two previously unidentified dehydroabietane isomers were isolated from Miocene Serbian lignite and Rhaetian (Late Triassic) coaly mudstones from South Sweden and characterized using NMRspectroscopy as cis- and trans-dehydroicetexane. Both have a 9(10?20)-abeo-abietane or icetexane skeleton, consisting of a 6-7-6 tricyclic framework with seven carbons in ring B instead of the usual six in common diterpanes of the abietane-type. Dehydroicetexanes can be detected using GC-MS-MS in m/z 270?146 chromatograms without interference from dehydroabietane or other isomers. Dehydroicetexanes are often abundant ...
    Geochemistry and Petrology

  • Geotechnical Conditions for Construction of Savski Trg Metro Station as a Part of the Belgrade Metro Line One

    Nemanja Stanic, Dragoslav Rakic, Josip Isek, Slavoljub Simic (2024)
    In order to solve serious traffic congestion in Belgrade, a number of studies regarding the Belgrade Metro construction have been carried out since 1973. However, only in 2019, the routes of the future metro lines 1 and 2 were de-fined as a part of the General Metro Construction Project. The lines are de-signed to intersect at the location of Sava Square, where an interchange met-ro station will be built. It represents a complex geotechnical structure consist-ing of three different ...
    metro station, geotechnical modelling, displacements

  • The influence of Al<sup>3+</sup>ion on porcine pepsin activity<i>in vitro</i>

    Vesna M. Pavelkić, Kristina R. Gopcević, Danijela Z. Krstić, Marija A. Ilić (2008)
    The in vitro effect of Al3þ ions in the concentration range 1.7·1026M–8.7·1023M on pepsin activity at pH 2, via kinetic parameters and its electrophoretic mobility was evaluated. Kinetic study demonstrated the existence of an activation effect of Al3þ at pH 2 on pepsin molecule. Kinetic analysis with respect to concentrations of haemoglobin showed that Al3þ ions increase the maximal velocity (Vmax) and kcat values rather than apparent affinity for substrate (KS) implying the non-competitive nature of activation which indicated ...
    Пепсин, алуминијум, кинетика, активација, електрофоретска мобилност
    ... removal of 44 amino acids, from its amino terminus, to give a single chain enzyme with a low pl and three disulfide bridges. Each lobe of pepsin contains a catalytic aspartic acid residue Asp?? and Porcine pepsin A (EC 3.4.23.1), a prominent member of the aspartic protease, is the principal ...
    ... decreased in a dose dependent manner (Figure 5 B). Figures 5 A and B shows only UV spectra in a presence ofIO0mM AP?. IR studies. IR spectra of pepsin and haemoglobin in KBr matrices in absence (solid curve 1) and in a presence 1IOmM Al ions (dotted curve 2) are presented in Figures 6 A and B. ...
    ... slope or intercept), (I/A) against 1 / [Al3+], where A is defined as slope or intercept in the absence of activator (Al' + ions) minus that in its presence. (1,5, 10mM) and intensity of characteristic peaks have been decreased in a dose dependent manner (Figure 5 A). However, the presence of ...

  • An intelligent hybrid system for surface coal mine safety analysis

    Nikola Lilić, Ivan Obradović, Aleksandar Cvjetić (2010)

  • Crystallography and Surface Oxidation of Stoichiometric Arsenopyrite from Šumadija-Kopaonik Pb-Zn/Polymetallic Ore District (Serbia)

    Ivana Jelić, Aleksandar Pačevski, Aleksandar Kremenović, Aleš Šoster, Andreja Šestan, Janez Zavašnik (2023)
    The behaviour and stability of arsenopyrite largely depend on its crystal structure, but studies of crystallography and structural defects are scarce. For clarification, we investigated a series of natural arsenopyrite crystals from the polymetallic Pb-Zn-(±Cu,Ag,Au,Sb,Bi,W) Šumadija-Kopaonik ore district (Serbia) by powder X-ray diffraction (XRPD). Among them, samples from the Drenjak gold mineralisation showed near-stoichiometric FeAsS composition and were further investigated by conventional and high-resolution transmission electron microscopy methods. TEM revealed abundant planar crystallographic defects and epitaxial surface oxide layer ...
    Inorganic Chemistry, Condensed Matter Physics,General Materials Science, General Chemical Engineering, crystal structure, FeAsS, oxidation, TEM, XRPD
    ... average unit cell values calculated as a mean of 14 measurements are a = 5.748(06) A, b = 5.680(85) A, c = 5.775(42) A, and B = 112.05(95)?*. The calculated val- ues for Drenjak locality, the mean of four measurements, are: a = 5.744(8) A,b= 5.678(55) A, c=5.774(03) A, and P = 112.05(65)”. As reported ...
    ... electron diffraction (SAED) of the pristine, homogenous region of arsenopyrite crystal are a =5.75 A,b =5.68 A, c= 5.76 A, a, y = 90*, and 8 = 111.5 . - TEM analysis of analysed arsenopyrite confirms a monoclinic crystal system, space group P2y-. We identified numerous polysynthetic {101} twinning ...
    ... average unit cell parameters measured by XRPD of near-stoichiometric arsenopy- rite from the Drenjak locality, as a mean of four measurements, are a = 5.744(8) A, b =5.678(55) A, c = 5.774(03) A, ., y = 90*, and 8 = 112.05(65) ?*. - The unit cell values calculated from the thin TEM sample using selected ...