Претрага

Упит dcterms_subject_txt:Economics and Econometrics

2341 items

  • 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 ...

  • Adaptive neuro-fuzzy prediction of operation of the bucket wheel drive based on wear of cutting elements

    Filip Miletić, Predrag D. Jovančić, Milos Milovančević, Dragan Ignjatović (2020)
    The capacity of the rotor excavator depends largely on the operation of the subsystem for digging. There is a great contribution to the correct and sharp teeth when the capacity is the highest. In the function of time, the teeth become clogged due to abrasive wear, or changes in their geometric shape. To analyze the bucket wheel drive in depend on wear of the cutting elements in this study adaptive neuro fuzzy inference system (ANFIS) approach was implemented. ANFIS ...
    Pogon rotornog točka, habanje, rezni elementi, ANFIS

  • Split-Desktop software for the analysis of fragment size distribution of blasted rock mass

    Milanka Negovanović, Lazar Kričak, Stefan Milanović, Jovan Marković, Nikola Simić, Snežana Ignjatović (2023)
    Drobljenje stena je najvažniji pokazatelj u proceni efekata miniranja pri proizvodnom miniranju u površinskoj eksploataciji. Stepen drobljenja stena ima veliki uticaj na efikasnost daljih operacija utovara, transporta, drobljenja i mlevenja. Optimalno drobljenje stena pri proizvodnom miniranju utiče na smanjenje ukupnih troškova proizvodnje. Stoga je pouzdana procena veličine drobljenja odminirane stenske mase veoma važno pitanje, ne samo u operacijama miniranja, već i u rudarskoj proizvodnji. Za predviđanje distribucije veličine komada odminirane stenske mase postoje različiti empirijski modeli. KUZ-RAM model omogućava ...
    Split-Desktop softver, drobljenje stena, miniranje, analiza, digitalna obrada fotografija

  • Results of comprehensive monitoring activities on Umka landslide, Belgrade, Serbia

    Biljana Abolmasov, Uroš Đurić (2021)
    klizišta, monitoring
    ... Faculty of Mining and Geology, Serbia, biljana.abolmasov@rgf.bg.ac.rs 2University of Belgrade, Faculty of Civil Engineering, Serbia, udjuric@grf.bg.ac.rs Background The Umka landslide is the deepest and biggest active landslide in the Republic of Serbia and has been investigated and monitored by ...
    ... will be focused on results and experience gained from automated Global Navigation Satellite System (GNSS) monitoring network data, PSInSAR data analysis from Sentinel1 radar satellite images, conventional geodetic monitoring network data and UAV imaging, processing and data analysis in the last six ...
    ... monitoring: automated GNSS monitorong network, geodetic benchmark survey monitoring, UAV imaging with photogrammetric processing and analysis, and PSInSAR data processing and analysis. Common to all implemented monitoring techniques is to measure displacement of the observed points (dx, dy, dz) on the ...

  • Strain partitioning around an indenter during oroclinal bending: kinematics of the Circum-Moesian fault system of the Carpatho-Balkanides

    Nemanja Krstekanić, Liviu Matenco, Uroš Stojadinović, Ernst Willingshofer, Marinko Toljić, Daan Tamminga (2021)
    ... of a foreland-convex orocline, situated in the north and east and a backarc-convexorocline situated in the south and west. The southern orocline of the Carpatho-Balkanides orogenformed during the Cretaceous closure of the Alpine Tethys Ocean and collision of the Dacia mega-unit with the Moesian Platform ...
    ... ing processes, the Carpathianssubduction and Miocene slab retreat in the West and East Carpathians have driven the formationof the backarc-convex oroclinal bending in the south and west. The orocline formed duringclockwise rotation of the Dacia mega-unit and coeval docking against the Moesian indenter ...
    ... South Carpathians and with a large late Oligocene – middleMiocene Circum-Moesian fault system that affected the orogenic system surrounding the MoesianPlatform along its southern, western and northern margins. This fault system is composed ofvarious segments that have different and contrasting types ...

  • Paleomagnetic evidence for post-collisional Miocene clockwise rotation in the Serbian segment of the Vardar Zone and the Danubicum

    Vesna Lesić, Emő Márton, Vesna Cvetkov, Dragana Tomić (2015)

  • Aлтерације перидотита контролисане карактером флуида на примеру харцбургита Рудника - Серпентинизација или талкизација?

    Стефан Петровић, Наталија Батоћанин (2020)
    У раду су приказани резултати испитивања серпентинисаних харцбургита Брђана (43°58'45.1" СГШ, 20°25'12.6" ИГД) и талкизираних харцбургита откривених у интервалу 429-559.8 m у истражној бушотини 330А/18 (44°07'33.2" СГШ, 20°30'28.5" ИГД) на Руднику. Узорци оба локалитета показују карактеристике резидуалних харцбургита из омотача, односно тектонита; лепидобластичне, бластозрнасте, или порфирокластичне структуре и масивне текстуре. Серпентинисани харцбургити и серпентинити Брђана су изграђени од серпентина, ретких реликата оливина и ортопироксена, акцесорног спинела, и веома ретког секундарног магнезита и магнетита. Најдоминантнији састојак (местимично гради и преко ...
    Рудник, Брђани, харцбургити, серпентинити, талк
    ... (hornfels and skarn), and acid and ultrabasic igneous rocks. Low-grade metamorphosed coarse-grained rocks include sandstones and conglomerates of preserved primary protolith textures. The alternation of skarn and hornfelses represents the most abundant lithology. It is cut by apophyses and a quartzlatite ...
    ... blastogranular or porphyroclastic texture and massive structure. Serpentinized harzburgites and serpentinites from Brdjani consist of serpentine, scarce relics from olivine and orthopyroxene, accessory spinel and very seldom secondary magnesite and magnetite. The prevailing constituent (sporadically ...
    ... verlite and dunite are subordinated, whereas feldspar-peridotites are extremely limited. All rocks are more or less serpentinized in the Maljen massif and almost completely transformed into serpentinites in the Mts. Suvobor. Mineral composition and the source of samples from Brdjani and Rudnik were ...

  • New data on Mesozoic Radiolaria of Serbia and Bosnia, and implications for the age and evolution of oceanic volcanic rocks in the Central and Northern Balkans

    Valentina Vishnevskaya, Nevenka Djerić, G.S. Zakariadze (2009)
    Geochemistry and Petrology, Geology

  • Geology of the southern part of the Sava-Vardar zone: new constraints from the Klepa Mts.

    Dejan Prelević, Ana Mladenović, Violeta Gajić, Milena Dunčić, Blažo Boev (2024)
    Tethys closure, Scaglia Rossa, intracontinental basalts
    ... carbonate rocks arc represented by reddish, locally pinkish, or grey, light grey hemipelagic and pelagic biomicrites with rich planktonic and · benthic · foraminiferal associations. and othcr diverse micro- and macrofossil assemblages (calcareous nannoplankton, calcified radiolarians, palynomorphs ...
    ... which encompasses the Dinaric, Carpathian, and Balkan double-verging Alpine orogenic belt, remains a topic of ongoing debate ({1], [2] and references therein). This orogenic system arose from thc closure of the northern branch of the Neotethys Ocean and subsequent collision-related processes. Key ...
    ... unique opportunity to study the nature and timing of the final closure of the Neotethys Ocean. The Klepa Mountains, situated in the central part of North Macedonia, form a block extending: 5-6 km NNW-SSE and 1-2 km WSW-ENE, reaching a hecight of 1150 m a.s.l. and serving as a prominent landmark in ...

  • Upper Cretaceous scaglia type limestone from Klepa Mts. (North Macedonia) - sedimentology and biostratigraphy

    Violeta Gajić, Milena Dunčić, Ana Mladenović, Dejan Prelević (2024)
    The research area is located in the central part of North Macedonia, in the area of the Klepa Mts. Based on sedimentological, micropaleontological and biostratigraphical investigations of samples from both the east and west side of the Klepa Mts., sedimentary rocks of the Upper Creaceous age are determined. During the latest Cretaceous, this area was dominated by the sedimentation of dominantly carbonate rocks with variable amounts of clastic components. From the tectonic point of view, investigated area belongs to the ...

  • Negative Impact of Backwater Levels of Danube River and its Tributaries to the Groundwater Regime in Meliorated Riverside Areas

    Predrag Pajić, Uroš Urošević, Dušan Polomčić, Milan Dimkić (2016)
    This paper describes updated calculation methodology of Danube backwater impact, occurred as a consequence of “Đerdap I” hydropower plant operation, onto the meliorated riverside areas. This methodology is based on hydrodynamic analysis of groundwater regime (size, duration, level and inflow changes) and quantification of melioration areas impairment which is caused by “Đerdap I” hydropower plant operation. By comparing the groundwater regime elements, obtained by variant hydrodynamic calculation in mathematical models for natural – not backed up and actual – ...
    HPP ''Djerdap 1'', backwater influence, groundwater regime, hydrodynamic analysis, melioration area, drainage system, additional energy engagement

  • Application of Expansive Mortars for the Formation of Artificial Screens During Blasting in Urban Areas

    Milanka Negovanović, Lazar Kričak, Stefan Milanović, Nikola Simić, Jelena Majstorović (2024)
    During construction of buildings in urban areas, sometimes there is a need to blast solid rock mass in the immediate vicinity of the surrounding buildings. In that case, the aim is not only to increase the efficiency of blasting, but also to reduce harmful effects of ground vibration induced by blasting. At the same time, it is very important to protect the buildings located in the safe zone from the blast site as well as remaining rock mass around ...
    expansive mortar, artificial screens, pressure, rock breaking, building foundation

  • Application of the Fuzzy Model in the Evaluation and Selection of Hydraulic Excavators on Open-Pit Lignite Mine

    Stevan Đenadić, Miloš Tanasijević, Vladimir Milisavljević, Dragan Ignjatović, Predrag Jovančić (2021)
    The production of lignite in large open-pit mines is mainly performed with continuously operating equipment, where bucket-wheel excavators, bucket-chain excavators, belt conveyors, and spreaders are the basic machines. Smaller machines, usually of discontinuous operating nature, are commonly categorized as auxiliary machines. This paper presents the research related to the analysis of auxiliary machine parameters with the case study for a hydraulic excavator. The purpose of the analysis was to develop a model of rating quality of service of the ...
    Fuzzy theory, hydraulic excavator, selection, quality of service, asset management

  • Serbian Society of Geomorphologists

    Dragana Đurić, Jelena Ćalić (2019)

  • A contribution to the knowledge of facial diversity of Badenian sediments in the Belgrade area

    Filip Anđelković, Dejan Radivojević (2018)
    baden, Beograd, facije, facijalna raznovrsnost, sedimenti
    ... erates  (on  Kalemegdan  and  in Rakovica  stream)  and  poorly  cemented  sandstones  and  sands  (type  locality  is  in  Rakovica  stream).  The  conglomerates  contain  numerous  Ostrea  shells  and  represent  a  basal  series.  According to Anđelković M. and Anđelković J., they mark the second ...
    ... composed of Mesozoic  sediments, ophiolites  and ophiolitic mélange, Cretaceous  to Paleogene  flysch  sediments  and  Lower Miocene  continental  sediments.  The  diversified  basin  basement  and  tectonic  processes during the Badenian led to the horizontal and vertical facial changes. Badenian sediments are  ...
    ... „Leitherkalk“  (Gruber,  1988)  or  „Leitha  limestones“)  and  Rakovica  clastic  sedi‐ ments (sands and conglomerates). There are two additonal facies in the Belgrade area, Višnjica clays and  Konjarnik schlier, but they have limited exposure and were inaccessible at the time of field exploration.  Th ...

  • The final closure of the Vardar Ocean: paleomagnetic, AMS and structural results

    Emö Márton, Marinko Toljić, Vesna Lesić, Vesna Cvetkov (2020)
    ... folded during the Upper Cretaceous and Paleogene and the paleomagneticsignals, which exhibit smeared distribution close to the present N, are of post-folding age. TheAMS foliation and bedding planes are sub-parallel, thus the deformation must have been weak.Fold axes and AMS lineations are roughly N-S oriented ...
    ... recently published and new paleomagnetic, AMS results in combination withstructural observations will be presented from Upper Cretaceous sediments and Oligocene–Lower Miocene igneous rocks representing the areas bordering the Sava zone from the westernand eastern sides, respectively and from the upper ...
    ... of the flanking areas and the general NE-SW orientation of thecompressional stress field outside of the zone. Acknowledgement. This work was financially supported by the National Development andInnovation Office of Hungary, project K 128625 and by the Ministry of Education and Science of theRepublic ...

  • Evidence for Badenian marine transgression in Belgrade (Serbia)

    Filip Anđelković, Dejan Radivojević (2019)
    ... Tašmajdan limestones, Višnjica clays and Konjarnik schlier (Anđelković M., 1987; Anđelković, M.&Anđelković, J., 1997; Anđelković F. & Radivojević, 2018). Of these, clastics (conglomerates, sands and sandstones) and limestones (mostly subreefal) have the greatest extent and palaeogeographic significance ...
    ... Mediterranean is the cause for the partial isolation and fall of salinity (Rögl, 1999). REFERENCES Anđelković, M. 1987. Geology of the wider Belgrade area – Geology and geodynamics. Institute for regional geology and palaeontology, Faculty of Mining and Geology, p. 428 (in Serbian) Anđelković, M., Anđelković ...
    ... Belgrade Faculty of Mining and Geology archives faculty publications available in open access, as well as the employees' publications. - The Repository is available at: www.dr.rgf.bg.ac.rs Evidence for Badenian marine transgression in Belgrade (Serbia) Filip Anđelković1 and Dejan Radivojević1 1University ...

  • A Knowledge-Based Approach to Mine Ventilation Planning in Yugoslav Mining Practice

    Nikola Lilić, Ivan Obradović, Ranka Stanković (2002)
    Ventilation system analysis is a complex process based on the calculation and analysis of numerous parameters. These problems can be successfully solved by the SimVent numerical package, but a full understanding and use of the obtained results require the involvement of an experienced specialist in the ventilation field. The solution was found in the creation of a hybrid system INVENTS, whose knowledge base represents a formalization of the expert knowledge in the mine ventilation field. In this paper, we ...
    ... structure and user interface. 1. Introduction The methodology of mine ventilation planning and design in contemporary Yugoslav mining theory and practice differs substantially from the traditional approach. Novel approaches take full advantage of the possibilities offered by computer hard- ware and software ...
    ... ward and easy manipulation of input data and control over different components of the problem-solving process. Through the interface the system also offers suggestions and recommendations to the user for the improvement of the overall performance of the mine ventilation system (Figs. 12 and 13). ...
    ... Design and Development (Macmillan Publishing Company, New York, 1994). 3. J. S. Kowalik (ed.), Coupling Symbolic and Numerical Computing in Expert Systems (North-Holland, Amsterdam, 1986). 4. N. Lilic, R. Stanković and I. Obradović, A hybrid system for mine ventilation systems planning and analysis ...

  • Отпад из процеса сагоревања угља као сировина за добијање елемената ретких земаља

    Бојан Земљак (2024)
    Због великог броја индустрија у којима се користе ови ресурси, глобална економија се у великој мери ослања на елементе ретких земаља. Елементи ретких земаља су есенцијална сировина — материјал за развој савремених технологија, али у односу на њихову огромну потражњу, њихово вађење је ограничено и повезано је са значајним утицајима на животну средину. Због њихове ограничене доступности, проблема који се јављају при процесима експлоатације, све више и више земаља почиње да тражи повољније могућности вађења елемената [REE] из секундарних ...
    Елементи ретких земаља, резерве, употреба, представници и методе опоравка елемената ретких земаља
    ... Kleit, A.N. and Nieto, A., 2017. An economics strategy for criticality— Application to rare earth element Yttrium in new lighting technology and its sustainable availability. Renewable and Sustainable Energy Reviews, 77, p.899-915. [151] Alves Dias, P., Bobba, S., Carrara, S. and Plazzotta, B ...
    ... between trivalent and tetravalent metallic cerium and other f-elements: stability study of various lanthanide-and actinide-halides and- oxides. Journal of Physics and Chemistry of Solids, 39(5), p.467-484. #1 [41] Zych, A.K., 2011. Luminescence properties of Ce3+, Pr3+ and Nd3+ activated ...
    ... , Wall, F. and Merriman, D., 2018. The rare earth elements: demand, global resources, and challenges for resourcing future generations. Nafura/ Resources Research, 27, p.201-216. [9] Kursun Unver, I. and Terzi, M., 2018. Distribution of trace elements in coal and coal fly ash and their recovery ...

  • Synthesis, characterization and photocatalytic examination of Co0.9Ho0.1MoO4 nanopowders

    Milena Rosić, Maja Milošević, Maria Čebela, Vladimir Dodevski, Vesna Lojpur, Radomir Ljupković, Aleksandra Zarubica (2023)
    ... microscopy (FESEM), and nitrogen adsorption method. The photocatalytic activity of acquired Cop.Hop , MoO, nanopowders was estimated by the photocatalytic degradation of crystal violet in aqueous solution. A simple and effective . method for controlling: the composition and morphology of Cop ...
    ... та у Београду [ДР РГФ] Synthesis, characterization and photocatalytic examination of Co0.9Ho0.1MoO4 nanopowders | Milena Rosić, Maja Milošević, Maria Čebela, Vladimir Dodevski, Vesna Lojpur, Radomir Ljupković, Aleksandra Zarubica | Programme and the book of abstracts 7th Conference of The Serbian Society ...
    ... Serbia For Publisher Dr Dragica Stanković Printing layout Dr. Jelena Maletaškić, Vladimir V. Srdić Press Faculty of Technology and Metalurgy, Research and Development Centre of Printing Technology, Karnegieva 4, Belgrade, Serbia Published: 2023 Circulation: 120 copies CIP – Karanorusanuuja ...