Academy of Science and Arts of the Republic of Srpska

Banja Luka, Bosnia and Herzegovina

Academy of Science and Arts of the Republic of Srpska

Banja Luka, Bosnia and Herzegovina
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Rakovic D.,University of Belgrade | Dugic M.,University of Kragujevac | Jeknic-Dugic J.,University of Niš | Plavsic M.,University of Belgrade | And 3 more authors.
BioMed Research International | Year: 2014

In the context of the macroscopic quantum phenomena of the second kind, we hereby seek for a solution-in-principle of the long standing problem of the polymer folding, which was considered by Levinthal as (semi)classically intractable. To illuminate it, we applied quantum-chemical and quantum decoherence approaches to conformational transitions. Our analyses imply the existence of novel macroscopic quantum biomolecular phenomena, with biomolecular chain folding in an open environment considered as a subtle interplay between energy and conformation eigenstates of this biomolecule, governed by quantum-chemical and quantum decoherence laws. On the other hand, within an open biological cell, a system of all identical (noninteracting and dynamically noncoupled) biomolecular proteins might be considered as corresponding spatial quantum ensemble of these identical biomolecular processors, providing spatially distributed quantum solution to a single corresponding biomolecular chain folding, whose density of conformational states might be represented as Hopfield-like quantum-holographic associative neural network too (providing an equivalent global quantum-informational alternative to standard molecular-biology local biochemical approach in biomolecules and cells and higher hierarchical levels of organism, as well). © 2014 Dejan Raković et al.

Keselj D.M.,University of East Sarajevo | Lazic D.Z.,University of East Sarajevo | Zivkovic Z.D.,University of Belgrade | Skundric B.T.,Academy of science and Arts of the Republic of Srpska | And 2 more authors.
Hemijska Industrija | Year: 2016

The paper presents mathematical models which describe the dependence between water sorption capacity, on one hand, and the degree of crystallinity and the content of Na2O and Al2O3 in NaY zeolite, on the other. NaY was synthesized from sodium aluminate solution, water glass and sulfuric acid under different conditions of crystallization. The obtained zeolite powders underwent chemical analysis (Na2O and Al2O3), water sorption capacity (WSC), as well as diffraction analysis which served to determine the degree of crystallinity (CD). Zeolite powder samples had the following values: for the content of Na2O from 13.81 to 16.14%, for Al2O3 from 21.58 to 27.17%, degree of crystallinity from 58.70 to 114.00 and WSC from 21.32 to 36.59%, and regression analysis lead to the conclusion that there is a significant correlation between water sorption capacity and the degree of crystallinity, unlike the contents of Na2O and Al2O3 in the zeolite powder, whose correlation with water sorption capacity was neglibile. The mathematical model obtained by linear regression analysis had a high R2 = 0.796, where as non-linear regressional analysis produced a better mathematical model R2 = 0.912, where water sorption capacity was expressed through a quadratic model. © 2016, Association of Chemists and Chemical Engineers of Serbia. All rights reserved.

Jacimovski S.K.,Academy of Criminalistic and Police Studies | Sajfert V.D.,University of Novi Sad | Rakovic D.I.,University of Belgrade | Setrajcicd J.P.,University of Novi Sad | Setrajcicd J.P.,Academy of science and Arts of the Republic of Srpska
Digest Journal of Nanomaterials and Biostructures | Year: 2012

We have transformed the Scott's model of protein Hamiltonian to metastable form, by means of double coherent unitary transformation. It turned out that in metastable Hamiltonian the number of quasi particles is not conserved due to the forming of pairs of excitations. The energies of pairs are found and their population is quoted. It is interesting that elementary excitations of metastable state behave similarly as excitations of molecular vibration field as well as excitations of electromagnetic field.

Tomic M.,NanoLab, Inc. | Muncan J.,NanoLab, Inc. | Stamenkovic D.,Optix | Jokanovic M.,Academy of science and Arts of the Republic of Srpska | Matija L.,NanoLab, Inc.
Journal of Physics: Conference Series | Year: 2013

Since materials on nanoscale have different characteristics from materials on macro scale their biocompatibility should be precisely and specifically investigated. Fullerenes, the third carbon allotrope, are one of the most used nanomaterials. The least stable and the most common is fullerene C60. One of the main disadvantages of fullerene is its low solubility in water. In order to make it soluble, it must be functionalized with polar groups such as -OH and -COOH. From all the water soluble fullerenes the most important ones are those with -OH groups attached named fullerols. We have developed new materials for contact lenses by adding fullerene (C60) and fullerol (C 60(OH)24) into PMMA. The aim of our investigation was to compare the influences of those materials on aqueous solutions similar to tear film. For the analysis of the solutions we used opto-magnetic imaging and IR spectroscopy. The acquired spectrums were commented and compared with the standard contact lens material, which was analyzed by the same methods. The ISO 10993 cytotoxicity test on extract of nanophotonic material with incorporated C60 was done as well. This research contributes to better understanding of the biocompatibility of new rigid gas permeable contact lens materials. © IOP Publishing Ltd 2013.

Armakovic S.,University of Novi Sad | Armakovic S.J.,University of Novi Sad | Pelemis S.,University of East Sarajevo | Mirjanic D.,University of Banja Luka | Mirjanic D.,Academy of science and Arts of the Republic of Srpska
Physical Chemistry Chemical Physics | Year: 2016

We investigate the influence of sumanene modifications on its adsorption properties towards the hydrogen molecule. The benzylic positions of sumanene were substituted with boron and nitrogen atoms, which changed its hydrogen storage properties. H2 binding energies were calculated using the LMP2, DFT and DFT-D3 approaches with several exchange-correlation functionals and the results indicate a physisorption mechanism. Physisorption was confirmed by fragment analysis and special attention was paid to non-covalent interactions. All non-covalent interactions, based on reduced density gradient surfaces, were identified and calculated for better understanding of the adsorption mechanism. Moreover, the significance of charge separation by inducing boron and nitrogen atoms is emphasized and special attention is paid to the z-component of the dipole moment of sumanene derivatives. © the Owner Societies.

Setrajcic J.P.,University of Novi Sad | Setrajcic J.P.,Academy of science and Arts of the Republic of Srpska | Markoski B.,University of Novi Sad | Rodic D.,University of Novi Sad | And 5 more authors.
Nanoscience and Nanotechnology Letters | Year: 2013

Electronic components are used today in extreme physical conditions and in that sense, ultrathin dielectric crystalline films could be used as surface layers for electronic component protection. Calculating dynamical permittivity by the single-pole Green's functions it was shown that the threshold of light absorption can be moved along frequencies, changing the film thickness and the intensity of boundary perturbations. We study the basic micro and macroscopic physical characteristics of symmetric ultrathin molecular crystalline films and one can see that essential optical properties of these systems arise with perturbation conditions, which appear at their surface layers. Depending on the values of the parameters of surface interactions, certain energy levels can lie outside the energy band of the ideal crystal, so there appear the surface localized states of excitons. Characteristic resonant peaks appear in the dependence of dielectric permittivity and absorption index (extinction coefficient) of ultrathin film on frequency of external electro-magnetic field. Copyright © 2013 American Scientific Publishers. All rights reserved.

Vulic D.,University of Banja Luka | Vulic D.,Center for Medical Research Banja Luka | Vulic D.,Academy of Science and Arts of the Republic of Srpska | Secerov-Zecevic D.,Academy of Science and Arts of the Republic of Srpska | And 3 more authors.
Current Cardiovascular Risk Reports | Year: 2012

One of the major risk factors that may promote atherogenesis is chronic stress. War and its consequences are powerful stress factors. Wars fought all over the world have changed global life conditions. A war is a mass disaster with several effects (death, injury, loss of close persons, exposure to various tortures, home eviction, exile, rapid impoverishment, social uncertainty) that brings tremendous suffering to the population affected. Stress causes increased concentrations of catecholamine and corticosteroid hormones in blood, which may lead to atherosclerosis and hypertension. On the behavioral side, stress is associated with smoking and alcohol abuse, which favors the development of cardiovascular disease. According to these indicators, we can see that chronic stress can promote all other factors of atherogenesis (hypertension, lipid metabolism, smoking, obesity due to improper diet and inadequate physical activity). Finally, increased cardiac mortality has been associated with the stress from war, particular from post-traumatic stress disorder. Further studies and possibly clinical trials to intervene on persons with war stress are warranted to best identify those at highest risk where intervention may be helpful to reduce subsequent cardiovascular events. © 2012 Springer Science+Business Media, LLC.

Milosavljevic D.D.,University of Niš | Pavlovic T.M.,University of Niš | Mirjanic D.L.J.,Academy of science and Arts of the Republic of Srpska | Divnic D.,Academy of science and Arts of the Republic of Srpska
Renewable and Sustainable Energy Reviews | Year: 2016

This paper focuses on the current state and perspectives of the application of PV solar plants in the Republic of Srpska. Further, the paper provides information on the PV application in Europe, geographical position, solar potential and Renewable Sources of Energy (RSE) legislative in the Republic of Srpska. Special attention is drawn to a 2.08 kWp PV solar plant installed on the building of the Academy of Sciences and Arts of the Republic of Srpska (ASARS) in Banja Luka. Experimental results obtained researching the influence of the climate conditions on the performance characteristics of PV plant on the ASARS building in Banja Luka in 2014 are given as well. It was found that the annual mean value of the energy efficiency of PV plant on the ASARS building in Banja Luka was 14.77% and that with the increase of the ambient temperature it decreased. The annual mean value of the performance ratio of PV plant was 95.9%, of the capacity factor 11.7% and of the specific yield factor 84.57 kWh/kWp. The presented results can be useful for the people working on the theory, planning, constructing, design and/or application of the PV based electricity generation systems in the Republic of Srpska. © 2016 Elsevier Ltd

Pavlovic T.M.,University of Niš | Milosavljevic D.D.,University of Niš | Mirjanic D.,Academy of science and Arts of the Republic of Srpska | Pantic L.S.,University of Niš | And 2 more authors.
Renewable and Sustainable Energy Reviews | Year: 2013

The paper focuses on the possibilities of generating electrical energy by means of on-grid PV solar systems of 1 kW in the Republic of Srpska (Bosnia and Herzegovina). The paper proceeds to tackle with the legislative concerning renewable sources of energy and current state of the use of PV systems in the Republic of Srpska and Bosnia and Herzegovina, climate conditions and energy potential of the renewable sources in the Republic of Srpska. Based on PVGIS program, the results of calculation of the yearly average values of the optimal panel inclination, solar irradiation on the horizontal, vertical and optimally inclined plane, ratio of diffuse to global solar irradiation, linke turbidity, average daytime temperature and 24 h average of temperature for 13 cities in the Republic of Srpska are given. Total for year sum of global irradiation per square meter received by the modules of the optimally inclined fixed PV solar plants of 1 kW, optimally inclined one-axis and dual-axis tracking PV solar plants of 1 kW, and total for year electricity production of different types of PV solar plant of 1 kW for 13 cities in the Republic of Srpska, obtained by PVGIS are given. Comparison of the total for year electricity production of different types of PV solar plant of 1 kW with monocrystaline silicon, CdTe and CIS solar modules, respective, to 13 cities in the Republic of Srpska are given. Calculations performed by PVGIS program have shown that irrespectable of the type of PV solar plants, most electrical energy in the Republic of Srpska can be generated by means of PV solar plants with CdTe solar cells. Some practical data and considerations given in this paper can be used by a customer or company keen to invest in the PV sector in the Republic of Srpska. © 2012 Elsevier Ltd. All rights reserved.

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