Institute for Information Technologies, Kragujevac

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Institute for Information Technologies covers several different fields of scientific studies through the exchange of information technology which covers the Faculty of Science, technical-technological studies, medical studies, biotechnical and social studies. By covering different fields of studies, the Institution creates a collaboration between the research groups of every field mentioned above, and by doing so it provides a better quality in research. As a result of its activities, the Institution provides the possibility of multidisciplinary research and collaboration of different researches. By following all of the latest research trends in modern science, and with the constant growth of computer science along with informational-communicative technology, the main idea of the Institution will be to develop this type of network.

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Scientific research of the Institution is focused on fundamental, applied research and basic focused research. It covers research programs in the fields of technological development, programs for knowledge transfer, and the stimulative use of scientific research results.

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Analytical characterization of lichexanthone in lichen: HPLC, UV spectroscopic, and DFT analysis of lichexanthone extracted from Laurera benguelensis (Mull. Arg.) Zahlbr.
(2010) Marković, Zoran; Manojlovic, Nedeljko
Lichexanthone, the major pigment present in the extract of Laurera benguelensis (Mull. Arg.) Zahlbr., was extracted from lichen, purified, and characterized by high-performance liquid chromatography (HPLC) and ultraviolet (UV) spectroscopy. The geometry of the lichexanthone conformers was optimized at the B3LYP/6-31+G** level of theory. It was found that all conformations have similar energies and that the corresponding lichexanthone radical is planar. In spite of its planarity, there is no significant electron delocalization over the radical. The antioxidant properties of lichexanthone were investigated using the colorimetric assay as Trolox-equivalent antioxidant capacity and at B3LYP/6-31+G** level of theory. Both methods revealed that lichexanthone has weak antioxidant properties. The results confirm the potential of HPLC-UV analysis for taxonomic characterization of lichen species. © Springer-Verlag 2010.
Computer model and clinical relevance of abdominal aorta aneurysm with compliant nonlinear material wall
(2010) Isailovic, Velibor; Koncar, Igor; Veljkovic D.; Milašinović, Danko; Nikolic, Dalibor; Markovic M.; Davidovic L.; Kojić M.; Filipovic, Nenad
In the abdominal segment of the human aorta under a patient's average resting conditions, pulsatile blood flow exhibits complex laminar patterns with secondary flows induced by adjacent branches and irregular vessel geometries. The hyperelastic material model of aorta wall should be taken into account. Prediction of influence of dynamic blood flow on natural history of aneurysmatic disease and outcome of therapeutic procedures could contribute to treatment strategy and results. In this study we examined fluid-structure interaction of pulsatile blood flow in the specific patient threedimensional model of abdominal aortic aneurysms (AAAs). Numerical predictions of blood flow patterns and nonlinear wall stresses in AAAs are performed in compliant wall isotropic model using the finite element method. © 2010 IEEE.
Phenylselenoetherification of some Δ⁴-alkenols facilitated by pyridine and some Lewis acids
(2010) Šmit, Biljana; Bugarčić Z.
Studies on the phenylselenoetherification of some Δ4- alkenols in the presence of pyridine and some Lewis acids are described. All alkenols underwent intramolecular cyclization yielding corresponding tetrahydrofuran or tetrahydropyran derivatives. Yield and diastereomeric ratio of the cyclic products depend on counterion of selenylating reagent used. We found that external additives, such as pyridine and some Lewis acids coordinating to the electrophilic and/or nucleophilic species are used to control the course of cyclizations with high degrees of efficiency and improve the level of stereoinduction. © 2010 HeteroCorporation.
A simulation of neutron interaction from Am-Be source with the CR-39 detector
(2010) Milenković, Biljana; Nikezic, Dragoslav; Stevanović, Nenad
Presented in this paper is a simulation of the interaction of neutrons emitted from a cylindrical Am-Be source with a CR-39 detector. A Fortran90 program, called Neutron.f90, has been written to determine the specifications of secondary particles (alpha particle or proton) and the kinematics of the interactions. A Monte Carlo method was used to simulate which interactions occurred with the constituents of the CR-39 detector, H, C and O atoms. Due to the detector composition, elastic and nonelastic scattering of neutrons is possible. In this paper, nonelastic scattering includes: inelastic scattering; the emission of an alpha particle (n,α) reaction and the emission of a proton (n,p) reaction. Cross sections of other reactions are very small and negligible in comparison with the above mentioned. The energy deposited per unit mass per one neutron was calculated. In addition the contribution to the energy deposited by the alpha particles and protons were determined separately. The program Neutron.f90 computes the coordinates of points in which interactions occur i.e. where secondary particles appear. The energy and angular distributions of protons are also represented in this paper. Another Fortran90 program, called Track-Visibility.f90, was written to calculate the number of visible proton tracks and to calculate the energy deposited per one neutron per one visible track. © 2010 Published by Elsevier Ltd. All rights reserved.
Review of existing energy management standards and possibilities for its introduction in Serbia
(2010) Jelić, Dubravka; Gordić, Dušan; Babic, Milun; Končalović, Davor; Sustersic, Vanja
Until recent times, energy management practices primarily consisted in replacing inefficient equipment and then using any number of methods to estimate obtained savings. Experience shows that positive effects of energy efficient improvements were decreased over time. There have been significant efforts over the last decade to define appropriate standards and best practices and implement the consistent energy management system to increase and maintain the energy savings. The knowledge gained from thousands of energy efficient projects is driving a transition from traditional tactical practice (one-time build and forget projects) to energy management strategies proposed and endorsed by a number of international organizations. The current status of internationally developed energy management standards, including an analysis of their shared features and differences is presented in this paper. The purpose of the analysis is to describe the current state of best practices for this emerging area of energy efficiency policymaking in order to study the possibility of implementation of energy management standards in Serbia and to estimate the effects and the potential for energy saving that would be made by its implementation.
Development of energy management system - Case study of Serbian car manufacturer
(2010) Gordić, Dušan; Babic, Milun; Jovicic, Nemanja; Sustersic, Vanja; Končalović, Davor; Živković, Dubravka
The procedure of development of energy management system applied to an existing company (Serbian car producer Zastava) is shown in the paper. The aim of the paper is to provide a guideline for entrepreneurs in metal-working industry in implementing energy management system. First of all, paper includes: critical analysis of existing energy management system (energy matrix), principles of effective energy management organization (with energy manager and energy team in its structure) and energy management politics. Based on the results of energy auditing and performed technological and economical feasibility studies several energy saving measures related to different energy sources (steam, hot water, compressed air, electricity and water) were proposed, implemented and valuated. The proposed measures are not exclusively related to car assembly industry; they can be easily applied to other metal-working facilities with minor modifications. Such energy management system reduces energy costs and increase profitability of a factory. © 2010 Elsevier Ltd. All rights reserved.
Analysis of the electricity production potential in the case of retrofit of steam turbines in a district heating company
(2010) Babic, Milun; Gordić, Dušan; Živković, Dubravka; Končalović, Davor
Today, in Serbia there are several sites with installed combined heat and power facilities. The most of these plants, for various reasons, do not produce electricity. One such plant is Energetika (Kragujevac, Serbia), which is primarily a district heating company. Steam generator in the plant has been installed in the 1970's and has worked in one short period of time. Installed steam turbines are 8 MW and 20 MW rated power. Energetika in accordance with the general trend of increasing energy efficiency of production process initiated revitalization of the plant. This revitalization started with a study which approach and the results are briefly given in the paper. All results show that retrofit of facility should be acceptable for the management. Developed scenarios indicate that in the case of the limited resources optimal retrofit should start with smaller turbine (8 MW rated power) then after providing the funds should continue with the retrofit of 20 MW turbine.
Efficiency of IVUS guided procedures in center without previous experience
(2010) Tasic, Nevena; Tasic, Mladen; Jagić, Nikola; Miloradovic, Vladimir; Sreckovic, Miodrag; Nikolić, Dušan
Introduction of IVUS procedures in the routine practice is not yet achieved nor there are significant studies that dealt with examining the success of IVUS guided PCI, showed a significant advantage over conventional angiography guided PCI. On the other hand a number of smaller studies give results for the benefit of IVUS. The aim of the research is to check the effectiveness of IVUS guided PCI in the center with no previous experience in performing intravascular ultrasound diagnostics. © 2010 IEEE.
Analysis of forces and moments in gerotor pumps
(2010) Ivanović, Lozica; Devedzic G.; Miric N.; Cukovic, Sasa
This article presents the analyses of the forces and moments between gears in contact with a gerotor pump. The objective was to reach a more accurate solution for the problems related to load distribution in trochoidalpumpswith fixed shaft axes.Calculation of contact forces is complex due to the simultaneous contact of several trochoidal teeth during the load transfer and additional compressive fluid forces that act on the teeth flanks. A simple physical model and a suitable analytical model are used for this analysis. Compressive fluid forces are simulated with single force applied in the middle of the line that separates the suction and upward pressure zone. During the teeth engagement there is also a change in fluid volumes between teeth. This creates pressure change that needs to be considered and calculated at an arbitrary moment of the engagement process. Finite element analysis (FEA) was used to determine the reaction forces that depend on instantaneous moments as well. Analysis shows that if a chamber pressure variation is taken into account, higher values of driving moment and support reaction forces will be generated. Designers can use the obtained results to develop a higher efficiency gerotor pumps.
Heavy metals, organics and radioactivity in soil of western Serbia
(2010) Dugalic G.; Krstic, Dragana; Jelic M.; Nikezic, Dragoslav; Milenković, Biljana; Pucarević, Mira; Zeremski, Tijana
Western Serbia is a region well-known for potato production. Concentrations of selected metals, polycyclic aromatic hydrocarbons (PAHs) and radioactivity were measured in the soil in order to evaluate the quality and characteristics. The examined soils (Luvisol and Pseudogley) showed unsuitable agrochemical characteristics (acid reaction, low content of organic matter and potassium). Some samples contained Ni, Mn and Cr above the maximal permissible concentration (MPC). The average concentration of total PAHs was 1.92mg/kg, which is larger than the maximal permissible concentration in Serbia but below the threshold values in the European Union for food production. The average radioactivity of 238U, 226Ra, 232Th, 40K and the fission product 137Cs were 60.4±26.2, 33.2±13.4, 49.1±18.5, 379±108 and 36.4±23.3Bq/kg. Enhanced radioactivity in the soils was found. The total absorbed dose rate in air above the soil at 1m height calculated for western Serbia was 73.4nGy/h and the annual effective dose was 90μSv, which are similar to earlier reports for the study region. © 2010 Elsevier B.V.
Preface
(2010) De Abreu N.; Cvetković, Dragan; Gutman I.; Nikiforov V.
About creation and reached goals of development policy in the area of energy efficiency, environmental protection and sustainable development in the city of kragujevac
(2010) Babic, Milun; Milovanovic, Dobrica; Jovicic, Nebojsa; Gordić, Dušan; Despotovic, Milan; Sustersic, Vanja; Živković, Dubravka; Končalović, Davor; Boskovic, Goran
This paper presents a methodology development and the results achieved in the process of establishing energy management system in the city of Kragujevac (Serbia) and in its public services. The paper is an overview of influential factors in the field of energy management, analyzing their impact on raising the energy efficiency of individual utility service and the city of Kragujevac, as a whole. The paper also presents the most interesting scientific and research projects realized in the co-operation of several actors which were co-ordinated by Regional Euro Energy Efficiency Center Kragujevac. The municipal companies together with the city administration are the direct beneficiaries of the results realized in the following areas: - Development of energy management in municipalities and the establishment of energy planning atthe local level; - Improvement of municipal services by applying energy efficiency measures in public enterprises: Energetika (heating), Čistoća (communal waste management), and Vodovod i kanalizacija (water and waste water management).
Non-linear transient heat conduction analysis of insulation wall of tank for transportation of liquid aluminum
(2010) Aleksandar, Nikolic; Slavkovic, Radovan; Zivic, Fatima; Zivkovic, Miroslav
This paper deals with transient non-linear heat conduction through the insulation wall of the tank for transportation of liquid aluminum. Tanks designed for this purpose must satisfy certain requirements regarding temperature of loading and unloading, duringtransport. Basic theoretical equations are presented, which describe the problem of heat conduction finite element analysis, starting from the differential equation of energy balance, taking into account the initial and boundary conditions of the problem. General 3-D problem for heat conduction is considered, from which solutions for two- and one-dimensional heat conduction can be obtained, as special cases. Forming of the finite element matrices using Galerkin method is briefly described. The procedure for solving equations of energy balance is discussed, by methods of resolving iterative processes of non-linear transient heat conduction. Solution of this problem illustrates possibilities of PAK-T software package, such as materials properties, given as tabular data, or analytical functions. Software alsooffers the possibility to solve non-linear and transient problems with incremental methods. Obtained results for different thicknesses of the tank wall insulation materials enable its comparison in regards to given conditions.
Overview of a new method for designing high efficiency small hydro power plants
(2010) Babic, Milun; Gordić, Dušan; Živković, Dubravka; Končalović, Davor; Milovanovic, Dobrica; Jovicic, Nebojsa; Despotovic, Milan; Sustersic, Vanja
Significant number of research projects in the area of renewable energy sources (especially for small hydro power plants) has been made within the Department for Energy and Process Engineering and Regional Euro Energy Efficiency Center at Faculty of Mechanical Engineering (University of Kragujevac, Serbia) since early eighties. The results are various; numerous domestic and international recognition and technical performance tell about the success of the research. Research projects have been following the technical and technological development of research equipment and economy growth. This has led to the development of software for designing turbines of small hydro power plants. In order to notify the public about possibilities of our software, in this paper is briefly described a mathematical model and procedures for calculating and designing of small hydro power for known conditions. As an argument for assessing the validity and potentialof our research results is shown constructedsmall hydro power plant Bosnia 1, 2 x 100 kW power.
Alteration of oxidative stress parameters in red blood cells of rats after chronic in Vivo treatment with cisplatin and selenium
(2011) Marković, Snežana; Žižić, Jovana; Šeklić, Dragana; Obradović, Ana; Ćurčić Milutinović, Milena; Cvetkovic, Danijela; Đorđević, Nevena; Ognjanovic, Branka; Štajn A.
In this study we evaluated the possible protective effects of selenium (Se) on hematological and oxidative stress parameters in rats chronically treated with cisplatin (cisPt). Four groups of Wistar albino rats were examined: a control, untreated rats (I), rats treated with Se (II), rats treated with cisPt (III), and rats treated with Se and cisPt (IV). All animals were treated for 5 days successively and killed 24 h after the last treatment. Hematological and oxidative stress parameters were followed in whole blood and red blood cells (RBC). Results showed that the chronic application of Se was followed by a higher number of reticulocytes and platelets, increased lipid peroxidation and GSH content in the RBC. Cisplatin treatment induced depletion of RBC and platelet numbers and an elevation of the superoxide anion, nitrites and glutathione levels. Se and cisPt co-treatment was followed by an elevation of the hematological parameters and the recovery of the glutathione status when compared to the control and cisPt-treated rats.
Antioxidant, antimicrobial and antiproliferative activities of five lichen species
(2011) Mitrovic, Tatjana; Stamenković P.; Cvetković V.; Tosic I.; Stankovíc M.; Radojevic, Ivana; Stefanović, Olgica; Čomić, Ljiljana; Šeklić, Dragana; Ćurčić Milutinović, Milena; Marković, Snežana
The antioxidative, antimicrobial and antiproliferative potentials of the methanol extracts of the lichen species Parmelia sulcata, Flavoparmelia caperata, Evernia prunastri, Hypogymnia physodes and Cladonia foliacea were evaluated. The total phenolic content of the tested extracts varied from 78.12 to 141.59 mg of gallic acid equivalent (GA)/g of extract and the total flavonoid content from 20.14 to 44.43 mg of rutin equivalent (Ru)/g of extract. The antioxidant capacities of the lichen extracts were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging. Hypogymnia physodes with the highest phenolic content showed the strongest DPPH radical scavenging effect. Further, the antimicrobial potential of the lichen extracts was determined by a microdilution method on 29 microorganisms, including 15 strains of bacteria, 10 species of filamentous fungi and 4 yeast species. A high antimicrobial activity of all the tested extracts was observed with more potent inhibitory effects on the growth of Gram (+) bacteria. The highest antimicrobial activity among lichens was demonstrated by Hypogymnia physodes and Cladonia foliacea. Finally, the antiproliferative activity of the lichen extracts was explored on the colon cancer adenocarcinoma cell line HCT-116 by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) viability assay and acridine orange/ethidium bromide staining. The methanol extracts of Hypogymnia physodes and Cladonia foliacea showed a better cytotoxic activity than the other extracts. All lichen species showed the ability to induce apoptosis of HCT-116 cells. © 2011 by the authors; licensee MDPI, Basel, Switzerland.
DFT study on singlet diradical character of zethrenes
(2011) Markovic, Svetlana; Radenkovic, Slavko; Marković, Zoran; Gutman I.
© Pleiades Publishing, Ltd., 2011. The diradical character of zethrenes was investigated using a symmetry-broken UB3LYP/6-311G(d, p) method. The number of hexagons in the investigated molecules ranges from 6 to 12. It was found that all zethrenes are singlet diradicals, whose diradical character increases with the increasing size of the molecules. A singlet diradical structure provides a possibility for an electron pair to occupy different parts of space, and allows for achieving aromatic stabilization. It can be predicted, on the basis of the singlet–triplet values, that even higher zethrenes will be singlet, but not triplet molecules.
Kinetics and mechanism of the reactions of Ru(II)-arene complex with some biologically relevant ligands
(2011) Rilak, Ana; Petrović, Biljana; Grguric-Sipka, Sanja; Tesic, Zivoslav; Bugarčić Z.
The reactions of ruthenium(II)-arene complex [RuII(η 6-p-cym)(pydc)Cl] (where p-cym = p-isopropyl toluene, pydc = 2,3-pyridinedicarboxylato) with biologically nitrogen-donor nucleophiles, such as guanosine-5′-monophosphate (5′-GMP), guanosine (Guo) and l-histidine (l-His) were studied by UV-Vis spectrophotometry and 1H NMR spectroscopy. The reactions were studied at pH 2.5 and at 7.2. All reactions were followed under pseudo-first order conditions with large excess of the nucleophiles. The selected nucleophiles have a high affinity for Ru(II)-arene complex. The reactivity of the used ligands follow the same order at both pH values: Guo > 5′-GMP > l-His, while the reactions at pH 7.2 are always faster. The negative entropies of activation (ΔS≠) support an associative mode of activation. However, the rate constants obtained by 1H NMR at 295 K in D2O follow the same order of the ligand reactivity. The hydrolysis of the [RuII(η6-p- cym)(pydc)Cl] complex was very fast and completed by the time the first spectrum was measured. Addition of excess of NaCl to equilibrium solutions reversed the hydrolysis. © 2011 Elsevier Ltd. All rights reserved.
Local aromaticity in benzoand benzocyclobutadieno- annelated phenanthrenes
(2011) Balaban A.; Gutman I.; Markovic, Svetlana; Simijonović, Dušica; Đurđević Nikolić, Jelena
The effects of benzo- and benzocyclobutadieno-(BCBD-)annelation on the local aromaticityćof the central ring (X) of phenanthrene were examined. The local aromaticityćof the ring X was estimated using a graph-theory-based index and two geometrybasedćindices. DFT calculations of phenanthrene congeners showed that many of thesećmolecules are nonplanar, with significant steric strain. All three indices indicate thatćthe effect of benzo-annelation is opposite to that of BCBD-annelation. The deviation ofćsome phenanthrene derivatives from planarity does not influence the effects of annelation.ćThis finding is in accord with some previously reported studies on the dependencećof the aromaticity of the ring(s) on distortion from planarity. © Taylor & Francis Group, LLC.
Hydrolysis of the amide bond in N-acetylated l-methionylglycine catalyzed by various platinum(II) complexes under physiologically relevant conditions
(2011) Zivkovic, Marija; Ašanin, Darko; Rajković, Snežana; Djuran, Miloš
The hydrolytic reactions between various Pt(II) complexes of the type [Pt(L)Cl2] and [Pt(L)(CBDCA-O,O′] (L is ethylenediamine, en; (±)-trans-1,2-diaminocyclohexane, dach; (±)-1,2-propylenediamine, 1,2-pn and CBDCA is the 1,1-cyclobutanedicarboxylic anion) and the N-acetylated l-methionylglycine dipeptide (MeCOMet-Gly) were studied by 1H NMR spectroscopy. All reactions were realized at 37 °C with equimolar amounts of the Pt(II) complex and the dipeptide at pH 7.40 in 50 mM phosphate buffer in D2O. Under these experimental conditions, a very slow cleavage of the Met-Gly amide bond was observed and this hydrolytic reaction proceeds through the intermediate [Pt(L)(H2O)(MeCOMet-Gly-S)]+ complex. In general, it can be concluded that faster hydrolytic cleavage of the MeCOMet-Gly dipeptide was observed in the reaction with the chloride complex than with corresponding CBDCA Pt(II) complexes. The steric effects of the Pt(II) complex on the hydrolytic cleavage of the amide bond in the MeCOMet-Gly dipeptide were also investigated by 1H NMR spectroscopy. It was found that the rate of hydrolysis decreases as the steric bulk of the CBDCA and chlorido Pt(II) complexes increase (en > 1,2-pn > dach). These results contribute to a better understanding of the toxic side effects of Pt(II) antitumor drugs and should be taken into consideration when designing new potential Pt(II) antitumor drugs with preferably low toxic side effects. © 2011 Elsevier Ltd. All rights reserved.

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