Претрага
950 items
-
Centar za hidrogeologiju karsta - 15 godina nauke i struke
... underwater camera for wells with a rotating lens. The CKH has: a camera for recording exploratory wells with a small diameter of up to 50 mm to a depth of 300 m, 4 vertical cameras (diameter 50-70 mm) with high resolution for recording to depths of 300 and 500 m and a camera with a rotating lens for ...
... Serbia, SGS, and CKH. It took place from June 14 to 20, 2019. Aweek with karst “A week with Karst, one of numerous activities to celebrate the International Year of Caves and Karst, was organized by CKH from June 1 to 7, 2021, with three separate events: a. CEKA 2021, from June 1 to 4, 2021, which ...
... exploitation objects The CKH is also equipped with the most modern portable field pumps for sampling groundwater from exploratory wells: Booster pump "Gigant". These are light autonomous pumps with the ability to sample water up to 60 m from wells with a diameter of only 50 mm. In addition to these ...urednici Saša Milanović, Ljiljana Vasić, Zoran Stevanović, Branislav Petrović. Centar za hidrogeologiju karsta - 15 godina nauke i struke, Beograd : Univerzitet u Beogradu, Rudarsko-geološki fakultet, Centar za hidrogeologiju karsta, 2023
-
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 ...... groundwater source, operating two production wells with a total capacity of 54 l/s; the TM groundwater source, using a single production well with a discharge rate of 35 l/s; and the LŽT - Kikinda groundwater source, which operated two production wells with a total capacity of 50 l/s. Effective ...
... protection zone [13]. Particle tracking can be used for various purposes. The backward particle tracking method with an uncertainty analysis of porosity, applying a Monte Carlo approach, with Geographic Information System (GIS) support, is a useful tool for delineating groundwater protection zones [14] ...
... (metres above sea level). The canal widths were specified according to a topographic map, with an elevation 0.5 m less than the minimum canal water level, and the thickness of the bottom canal layer of 0.15 m, with a hydraulic conductivity of 1 × 10-6 m/s. Using the same boundary condition (head-dependent ...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
-
Application of Gel for Water Shutoff: A Case Study of Kelebija Oil Field
This paper focuses on the results of water shutoff operations using DSGA polymer gel in the Kelebija oil field. The methodology of candidate wells selection and the manner of performing the operation will also be included. The Kelebija oil field is characterized by a complex reservoir system with heterogeneous layers of different permeability and dual porosity, which led to the early breakthrough of water. For the last 25 years, average water cut was above 90%. Implementation of water shutoff ...intervención de pozos petroleros, reservoir characterization, production control, well logging, downhole intervention, enhanced recovery, complex reservoir, reservoir surveillance, water shut-off, upstream oil & gasIrina Zahirovic, Petar Skrobonja, Dušan Danilović. "Application of Gel for Water Shutoff: A Case Study of Kelebija Oil Field" in SPE Production & Operations, SPE (2022). https://doi.org/10.2118/209590-PA
-
The use of biological markers in determination of origin and type of organic matter in the Tisza river sediments
Snežana Štrbac, Gordana Gajica, Aleksandra Šajnović, Nebojša Vasić, Ksenija Stojanović, Branimir Jovančićević (2013)The objective of the study was to determine the origin and type of organic matter (OM) of the Tisza recent sediments along the distance of 153 km through the territory of Serbia. For this purpose group organic-geochemical parameters and biomarker compositions were used. All samples contain approximately same amount of OM, which was deposited under uniform, slightly reducing conditions. Based on the distribution of n-alkanes, the origin and type of OM could not be precisely estimated. However, n-alkane patterns ...... The saturated hydrocarbon fraction was eluted with n-hexane, aromatic hydrocarbons with mixture of n-hexane and dichloro- methane (4:1 volume ratio) and the NSO fractions (polar fraction, which contains nitrogen, sulphur, and oxygen compounds) with mixture of dichloromethane and methanol (1:1 volume ...
... removal of carbonates with 1:3 diluted hydrochloric acid. The measurements were realized using a Vario EL III, CHNS/O elemental analyzer, Elementar Analysensysteme GmbH. Soluble organic matter (bitumen) was extracted (36 h) from pulverized samples using a Soxhlet apparatus with an azeotropic mixture ...
... hydrocarbons were low, which is in accordance with the low maturity of the surface sedimentary organic matter (Table II). The contents of nitrogen and sulphur were also relatively uniform. The content of sulphur did not exceed 0.1 %, indicating that pollution with sulphur compounds could be discounted. ...Snežana Štrbac, Gordana Gajica, Aleksandra Šajnović, Nebojša Vasić, Ksenija Stojanović, Branimir Jovančićević. "The use of biological markers in determination of origin and type of organic matter in the Tisza river sediments" in Journal of Serbian Chemical Society, Beograd : Srpsko hemijsko društvo (2013). https://doi.org/10.2298/JSC130614087S
-
On the compatibility of lexical resources for NooJ
Lexical resources for many languages are provided for the NooJ linguistic development environment. Meta-data descriptions of morphosyntactic and semantic properties of these languages and their resources are a mandatory part of each language module. In this paper we analyze how well the meta-data actually describe resources for a chosen subset of languages and to what extent are they compatible across languages to support multilingual processing. We show that there is place for improvement in both directions.... and the order they were applied for Proceedings of the 2011 International NooJ Conference 7 languages with more than one dictionary and morphology graph. Hence, they should be taken with a grain of salt. An interesting result of the analysis was that categories exist in dictionaries that ...
... +Hum 3661 HumColl +HumColl 20 +HumColl 139 +CollHum 94 Table 5. NooJ expressions used with noun patterns Another experiment along the same lines was performed with NooJ graphs. In order to analyze the results of the application of same/similar graphs in the text, a simplified ...
... expected for NooJ to become an open source product running on various platforms, independent from Microsoft OS and its components, albeit compatible with them. From the point of view of Serbian, there was additional interest in this issue in view of the fact that the development of a new Serbian module ...Ranka Stanković, Miloš Utvić, Duško Vitas, Cvetana Krstev, Ivan Obradović. "On the compatibility of lexical resources for NooJ" in Automatic Processing of Various Levels of Linguistic Phenomena: Selected Papers from the 2011 International Nooj Conference, Cambridge Scholars Publishing (2012): 96-108
-
A necessary and sufficient condition for an algebraic integer to be a Salem number
Dragan Stankov (2019)We present a necessary and sufficient condition for a root greater than unity of a monic reciprocal polynomial of an even degree at least four, with integer coefficients, to be a Salem number. This condition requires that the minimal polynomial of some power of the algebraic integer has a linear coefficient that is relatively large. We also determine the probability that an arbitrary power of a Salem number, of certain small degrees, satisfies this condition.Algebraic integer, the house of algebraic integer, maximal modulus, reciprocal polynomial, primitive polynomial, Schinzel-Zassenhaus conjecture, Mahler measure, method of least squares, cyclotomic polynomialsDragan Stankov. "A necessary and sufficient condition for an algebraic integer to be a Salem number" in Journal de theorie des nombres de Bordeaux (2019). https://doi.org/10.5802/jtnb.1076
-
Modern self-propelled surface drill rigs for drilling small diameter holes in mining and construction operations
Milanka Negovanović, Lazar Kričak (2021)Приликом одређених рударских или грађевинских радова потребно је извршити минирање применом бушотина малог пречника. Раније, бушење бушотина малих пречника се изводило углавном ручним бушилицама или лаким лафетним бушилицама нa одређеним нoсачима. Проблеми у овим случајевима били су капацитет бушења, бушење већих дужина бушотина и посебно безбедност оператера на неприступачним теренима, где је његово присуство било неопходно. Данас постоје модерне самоходне бушилице за бушење минских бушотина малог пречника, које су у потпуности даљински управљане. Радио даљинска контрола омогућава да се ...Бушилице,бушотине малог пречника, бушење, минирање,изградња,минирање негабарита, радио даљинска контролаMilanka Negovanović, Lazar Kričak . "Modern self-propelled surface drill rigs for drilling small diameter holes in mining and construction operations" in 8th International Conference Mining And Environmental Protection, Sokobanja, 22 – 25th September 2021 SERBIA,, University of Belgrade, Faculty of Mining and Geology, Belgrade, Serbia (2021)
-
Influence of geological substrate on runoff formation, a case study: small river catchments in southeastern Serbia of similar size and with comparable pluviographic regimes
Vesna Ristić Vakanjac, Veljko Marinović, Nikola Milovanović, Marina Čokorilo Ilić, Boris Vakanjac, Jugoslav Nikolić, Saša Bakrač (2022)We are witnessing climate change that is happening both, globally and, at the regionally - or local level. As a result of expected climate change in Southeast Europe, in the first place are the distributions of precipitation within the year (frequent extreme events are present) and then the increase in temperature, which already has a significant impact on evapotranspiration and runoff formed in a particular catchment area. In addition to climatic factors, the geological structure, i.e. the hydrogeological characteristics ...Vesna Ristić Vakanjac, Veljko Marinović, Nikola Milovanović, Marina Čokorilo Ilić, Boris Vakanjac, Jugoslav Nikolić, Saša Bakrač. "Influence of geological substrate on runoff formation, a case study: small river catchments in southeastern Serbia of similar size and with comparable pluviographic regimes" in XXII International Congress of the Carpathian Balkan Geological Association (CBGA), Sofia : Bulgarian Academy of Sciences (2022)
-
Optimisation of underground mine decline development system using genetic algorithm
... (3–dimensional underground space) there is a point through which we can connect all ore bodies with surface portal (or surface breakout point, SBP) and afterward with mineral processing facility (MPF), with minimum costs. This point is called underground mass concentration point (UMCP). Basic hypothesis ...
... stochastic techniques whose search methods model a natural evolution. The genetic algorithms start with randomly chosen parent chromosomes from the search space to create a population. They work with chromosome genotype. The population evolves toward the better chromosomes by applying genetic operators ...
... The selection occurs with a given probability on the base of fitness functions. The fitness function plays a role of the environment to distinguish between good and bad solutions. The recombination is carried out after selection process is finished. It combines, with predefined probability ...Zoran Gligorić, Aleksandar Ganić, Rade Tokalić, Aleksandar Milutinović. "Optimisation of underground mine decline development system using genetic algorithm" in Underground mining engineering, Beograd : Univerzitet u Beogradu – Rudarsko–geološki fakultet (2014)
-
Available technological procedures for capturing CO2 in the industrial and power generation sectors
Climate change is a major environmental issue caused by anthropogenic emissions of greenhouse gases. Capturing CO2 and storing it in suitable geological formations is one of the main technological solutions that can provide mitigation of CO2 emission into the atmosphere. Capturing CO2 represents the first phase in process of carbon capture and storage, and includes the application of various technologies for the separation of CO2 produced in the energy and industrial sectors. There are four main systems for capturing ...... procedures for separation of CO2 that includes adsorption, absorption, membrane-based separation and cryogenic distillation, with en emphasis on technical challenges along with advantages and disadvantages. mailto:dusan.danilovic@rgf.bg.ac.rs mailto:branko.lekovic@rgf.bg.ac.rs mailto:miroslav.crnogorac@rgf ...
... There are various commercially available technological procedures that could be employed with post-combustion capture, but the preferred and the most advanced post-combustion option is chemical absorption with amine solvents [6,8]. Post-combustion CO2 capture is advantageous because it can be integrated ...
... consumption, high regeneration rate, simplicity in application with wide temperature and pressure range and low investment costs [24,28]. The main drawback of this technological process is that it can be applied in the case of flue gases with low CO2 concentration [28]. For the reason that power plants ...Lola Tomić, Vesna Karović Maričić, Dušan Danilović, Branko Leković, Miroslav Crnogorac. "Available technological procedures for capturing CO2 in the industrial and power generation sectors" in 8th International Conference Mining and Environmental Protection, 22 – 25th September 2021, Serbia, Univerzitet u Beogradu, Rudarsko-geološki fakultet (2021)
-
Field Zoning According to the Possibility of Applying Mechanized Excavation With a Longwall Below the Town of Gacko
Dragana Savić, Jelena Majstorović (2021)Mogućnost povećanja korišćenja resursa čvrstog energetskog goriva u procesu rešavanja energetske krize koja je sve prisutnija u širem regionu, jeste pravi izazov rudarske nauke. Podzemna eksploatacija uglja je složen proizvodni proces koji objedinjuje više tehnoloških postupaka u jedinstvenu celinu: izradu podzemnih prostorija, otkopavanje, transport i izvoz, ventilaciju proizvodnog sistema, odvodnjavanje, servisiranje objekata i sistema, zaštitu i sigurnost rada. Jedan od osnovnih problema koji prati podzemnu eksploataciju uglja jeste stabilnost podzemnih prostorija i deformacije na površini terena, jer su podzemne ...mehanizovano otkopavanje, mehanizovano široko čelo, zoniranje terena, modeliranje, stabilnost, sleganje, stabilnost kosinaDragana Savić, Jelena Majstorović. "Field Zoning According to the Possibility of Applying Mechanized Excavation With a Longwall Below the Town of Gacko" in 10 th International Conference Coal 2021 Zlatibor, 13-16 October 2021, Jugoslovenski komitet za površinsku eksploataciju (2021)
-
Serbian ELTeC Sub-Collection in Wikidata
This paper presents an example of integration of Wikidata with digital libraries and external systems, as well as some best practices for speeding up the process of data preparation and import to Wikidata, on the use case of SrpELTeC, Serbian subcollection of the ELTeC multilingual collection (European Literary Text Collection). After preliminary work on the manual Wikidata population with SrpELTeC novels, the goal was to automate the process of preparing and importing information, so different solutions were analysed and ...Milica Ikonić Nešić, Ranka Stanković, Biljana Rujević. "Serbian ELTeC Sub-Collection in Wikidata" in Infotheca, Faculty of Philology, University of Belgrade (2021). https://doi.org/10.18485/infotheca.2021.21.2.4
-
Manganese-pyromellitate complex as a precursor for preparation of spinel Mn3O4
Lidija Radovanović, Željko Radovanović, Aleksandar Kremenović, Bojana Simović, Milica V. Vasić, Jelena Rogan (2022)In recent years, thermal decomposition studies of transition metal complexes with benzenepolycarboxylate ligands have become an area of a great importance due to the possibility of obtaining useful metal oxides with desirable electrical, magnetic and catalytic properties [1]. As a contrast to conventional methods for the preparation of metal oxides, such as hydrothermal or sol–gel treatment, thermolysis is faster, more efficient ...Lidija Radovanović, Željko Radovanović, Aleksandar Kremenović, Bojana Simović, Milica V. Vasić, Jelena Rogan. "Manganese-pyromellitate complex as a precursor for preparation of spinel Mn3O4 " in XIV Conference of chemists, technologists and environmentalists of Republic of Srpska, Academy of sciences and arts of the Republic of Srpska, Banja Luka, Republic of Srpska, B&H, October 21st-22nd, 2022, University in Banjaluka, Faculty of Technology (2022)
-
Investigation of nanostructured Ca0.9Er0.1MnO3 obtained by sucrose nitrate procedure
Tijana B. Vlašković, Bojana Laban, Maja Milošević, Maria Čebela, Vladimir Dodevski, Milena Rosić (2023)... Serbia, P.O. Box 522, 11001 Belgrade, Serbia,University of Belgrade Nano-crystalline CaooEro,, MnOa oxide with a perovskite structure was synthesized by the sucrose nitrate procedure (SNP), with the help of sucrose, which plays the role of fuel and complexant. Other chemicals used are calcium nitrate ...
... purpose, two geometries of specimens were used. Flat specimens with crack loaded in tension and ring specimens loaded on the inner wall. To understand the influence of geometry, specimens and their identical models were tested with three different ratios between the width of the test specimens ...
... »O, erbium nitrate pentahydrate Er(NOay)ax5H»O. Metal nitrates and sucrose were mixed in stoichiometric ratios, in order to obtain a perovskite with a crystalline structure. The resulting: CapEro,, MnOxy is calcined for 15 minutes in the temperature range from 800% to 1000%. Diffraction thermal ...Tijana B. Vlašković, Bojana Laban, Maja Milošević, Maria Čebela, Vladimir Dodevski, Milena Rosić. "Investigation of nanostructured Ca0.9Er0.1MnO3 obtained by sucrose nitrate procedure" in Program ; and the Book of abstracts The Eleventh Serbian Ceramic Society Conference »Advanced Ceramics and Application« September 18-20, 2023 Serbian Academy of Sciences and Arts, Belgrade, Serbia , Belgrade : Serbian Academy of Sciences and Art Serbia (2023)
-
Sinteza i strukturna karakterizacija novih cezijumskih i kalijumskih silikata sa elementima retkih zemalja
Predrag Z. Dabić (2022)Predmet i ciljevi naučnog istraživanja ove doktorske disertacije su sinteza i strukturna karakterizacija novih cezijumskih i kalijumskih silikata sa elementima retkih zemalja. Istraživanja su izvedena u okviru sistema SiO2–REE2O3–XF, gde REE predstavlja trovalentni katjon elementa retkih zemalja (Sc, Y, Sm, Eu, Gd, Ho, Er, Tm, Yb, Lu), dok X predstavlja jednovalentni katjon alkalnih metala (K, Cs). Rad na disertaciji bio je fokusiran na sintezu monokristala, određivanje kristalnih struktura, kao i na kristalografsko i kristalohemijsko ispitivanje sintetisanih monokristala. Monokristali su sintetisani ...alkalni silikati elemenata retkih zemalja, kristalna struktura, sinteza metodom fluksa, rendgenska difrakcija na monokristalu, elementi retkih zemaljaPredrag Z. Dabić. Sinteza i strukturna karakterizacija novih cezijumskih i kalijumskih silikata sa elementima retkih zemalja, Beograd : P. Dabić, 2022
-
Epidotizacija sanidina u kvarclatitima Grota
Propilitska alteracija je veoma česta u gornjokredno-tercijarnim vulkanitima Srbije. Kvarclatiti Grota, otkriveni na dubini od oko 550 m u jednoj od istražnih bušotina su holokristalaste porfirske strukture sa fenokristalima sanidina dimenzija i do 1,5 x 2 cm. Optičkim ispitivanjima su u kvarclatitu potvrdjeni i elementi sitaste, pojkilitske i glomeroporfirske strukture. Kao fenokristali prisutni su sanidin, plagioklas, kvarc, biotit i amfiboli. Sekundarni minerali su hlorit, epidot, coisit, Fe-hidroksidi, redak kalcit i ilit. U fenokristalima sanidina se zapažaju „lepeze“ izduženih kristala ...Danica Srećković-Batoćanin, Suzana Erić, Nikola Novičić, Nikola Pašajlić, Natalija Batoćanin. "Epidotizacija sanidina u kvarclatitima Grota" in III Congress of Geologists of Bosnia and Herzegovina with international participation, Neum, 21. – 23.09.2023, Ilidža : Udruženje/udruga geologa u Bosni i Hercegovini (2023)
-
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
-
Assessments of effects of implementation of strategic plans for development of Belgrade District heating system
The district heating system (DHS) is one of the key elements of the Belgrade energy system. Overview of the current state and basic characteristics of the DHS are presented in this paper. The focus is on the planned development of DHS and on the analyses of effects of realization of measures and projects defined by strategic documents related to DHS which are adopted by city authorities (Development Strategy of DHS and Strategy of Belgrade Development). Two exploratory scenarios were ...Dejan Ivezić, Marija Živković, Aleksandar Madžarević, Miodrag Grujić. "Assessments of effects of implementation of strategic plans for development of Belgrade District heating system" in Sustainable Cities and Society, Elsevier BV (2020). https://doi.org/10.1016/j.scs.2020.102304
-
An aproach to Implementation of blended learning in a university setting
... support the teaching process at FMG, starting with an outline of FMG CMS (Course Management System) – an in-house developed web portal for courses, which we describe in the next Section. In Section 3 we cover the general Moodle issues, starting with a brief overview of some technical aspects, followed ...
... period, a total of 15 courses were created on Moodle during the academic year 2010/11, with about 450 students enrolled. As in other similar products, different user roles are available in Moodle, with each role having its specific permissions. Besides the administrator, the two most important ...
... instruction class, so that the students can get prepared for it. For each of the 15 instructional weeks, a lesson with the content presented in the classroom lecture is available, often with additional multimedia content. The lesson content is basically what students need to prepare for the oral exam ...Ivan Obradović, Ranka Stanković, Olivera Kitanović, Jelena Prodanović . "An aproach to Implementation of blended learning in a university setting" in Proceedings of the Second International Conference on e-Learning, eLearning 2011, September 2011, Belgrade, Serbia, Belgrade : Belgrade Metropolitan University (2011)
-
Using Query Expansion for Cross-Lingual Mathematical Terminology Extraction
Velislava Stoykova, Ranka Stanković (2018)Velislava Stoykova, Ranka Stanković. "Using Query Expansion for Cross-Lingual Mathematical Terminology Extraction" in Advances in Intelligent Systems and Computing, Springer International Publishing (2018). https://doi.org/10.1007/978-3-319-91189-2_16