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The paper discusses the extension of the Global Health Security (GHS) index with new non-medical predictors: Gross Domestic Product (GDP) per capita as a basic indicator of economic growth, Corruption Perception Index (CPI) and Democracy Index (DI) as significant indicators of social relations. This extension of the GHS index provides a more reliable model for predicting the ability of a country's health system to provide an adequate response in a pandemic crisis when human health is seriously endangered. Evaluation of the results of the extension of the GHS index by additional non-medical predictors was performed using multiple linear regression analysis (MLRA), both for the basic and for the extended model. The obtained values of the coefficient of determination (R2) indicate that the extended GHS model shows the same high level of fitting as the basic model, which confirms the justification of its extension. The research was conducted on the basis of available data for 42 European countries.

This paper presents the results of the research on the basic motivation of people to engage in scientific research and publication of the obtained results. The main problems regarding mentioned activities which occur today are manifested in the emergence of numerous frauds in the form of plagiarism, autoplagiarism, false publications and predatory publications. The most important purpose of publishing the scientific and research results is achieving their visibility. Visibility of a published result enables a critical review of its merits by other researchers through the utilization of the published results for the purpose of further research, i.e. their citation, which represents the most reliable criterion for measuring the quality of the published result. In this paper a comparative analysis of the most famous citation databases is presented which include Google Scholar Metrics (GSM), Clarivate Journal Citation Reports (JCR), SCimago Journal Ranking (SJR), Web of Science and Elsevier's SCOPUS database, in which the ranking of the quality of scientific publications is based on the so-called impact factor (IF). Furthermore, a very popular h-index is also described as an indicator of the results achieved by a particular researcher.

The paper presents the results of the SWOT - AHP model for prioritization of strategies for the development of viticulture in Jablanica District. On the basis of SWOT analysis, TOWS matrix was generated in which four possible strategies were defined based on the importance of sub-criteria under each SWOT criteria: SO1, WO1, ST1 and WT1 which enable the growth and development of viticulture in the region. Prioritization of the defined strategies was performed using multi-criteria Analytical Hierarchy Process (AHP) model based on the results of the SWOT analysis. The resulting prioritization WO1 → SO1 → WT1 → ST1 provides continuous performance improvement and growth of viticulture in the Jablanica District in the future.

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, 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.

Selective arsenic extraction from enargite based complex concentrate from Copper Mine in Bor (Serbia), using sodium hypochlorite as a leaching agent, was investigated in this paper. The aim was to assess the optimal conditions for the most efficient arsenic removal from the investigated concentrate, based on factorial design applied to experimentally obtained data. Five important factors with three factor levels were used as the input variables and experimentally obtained arsenic extraction yield was taken as the output variable. The first and the second final order model equations were obtained. It was found that the leaching temperature had the strongest effect on the arsenic extraction. The strongest positive interaction was between the sodium hypochlorite molar concentration and the stirring speed during extraction. [Projekat Ministarstva nauke Republike Srbije, br. TR 34023]

This paper presents the results of the tropospheric ozone concentration modeling as the dependence on volatile organic compounds - VOCs (Benzene, Toluene, m,p-Xylene, o-Xylene, Ethylbenzene); nonorganic compounds - NOx (NO, NO2, NOx, CO, H2S, SO2 and PM10) in the ambient air in parallel with the meteorological parameters: temperature, solar radiation, relative humidity, wind speed and direction. Modeling is based on measured results obtained during the year 2009. The measurements were performed at the measuring station located within an agricultural area, in vicinity of city of Zrenjanin (Serbian Banat, Serbia). Statistical analysis of obtained data, based on bivariate correlation analysis indicated that accurate modeling cannot be performed using linear statistics approach. Also, considering that almost all input variables have wide range of relative change (ratio of variance compared to range), nonlinear statistic analysis method based on only one rule describing the behavior of input variable, most certainly wouldn’t present accurate enough results. From that reason, modeling approach was based on Adaptive-Network-Based Fuzzy Inference System (ANFIS). Model obtained using ANFIS methodology resulted with high accuracy, with prediction potential of above 80%, considering that obtained determination coefficient for the final model was R2=0.802.

This paper presents the results of statistical modeling of the bauxite leaching process, as part of Bayer technology for an alumina production. Based on the data, collected during the period between 2008 - 2009 (659 days) from the industrial production in the alumina factory Birač, Zvornik (Bosnia and Herzegovina), the statistical modeling of the above mentioned process was performed. The dependant variable, which was the main target of the modeling procedure, was the degree of Al2O3 recovery from boehmite bauxite during the leaching process. The statistical model was developed as an attempt to define the dependence of the Al2O3 degree of recovery as a function of input variables of the leaching process: composition of bauxite, composition of the sodium aluminate solution and the caustic module of the solution before and after the leaching process. As the statistical modeling tools, Multiple Linear Regression Analysis (MLRA) and Artificial Neural Networks (ANNs) were used. The fitting level, obtained by using the MLRA, was R2 = 0.463, while ANN resulted with the value of R2 = 0.723. This way, the model, defined by using the ANN methodology, can be used for the efficient prediction of the Al2O3 degree of recovery as a function of the process inputs, under the industrial conditions of the alumina factory Birač, Zvornik. The proposed model also has got a universal character and, as such, is applicable in other factories practicing the Bayer technology for alumina production.

This paper presents the results of multi-linear regression analysis (MLRA) of the slag composition (SiO2, FeO, Fe3O4, CaO, Al2O3) and the content of copper in the matte on resulting copper content in the slag during smelting of the sulfide concentrates in the reverberatory furnace. When comparing results obtained with MLRA model calculations with values measured at industrial level high degree of fitting is obtained (R2 = 0.974). This indicates that slag composition and content of copper in the matte influences the copper losses in the waste slag with the probability of 95 %.

Life-cycle assessment (LCA) presents a relatively new approach, which allows comprehensive environmental consequences analysis of a product system over its entire life. This analysis is increasingly being used in the industry, as a tool for investigation of the influence of the product system on the environment, and serves as a protection and prevention tool in ecological management. This method is used to predict possible influences of a certain material to the environment through different development stages of the material. In LCA, the product systems are evaluated on a functionally equivalent basis, which, in this case, was 1000 cubic centimeters of an alloy. Two of the LCA phases, life-cycle inventory (LCA) and life-cycle impact assessment (LCIA), are needed to calculate the environmental impacts. Methodology of LCIA applied in this analysis aligns every input and output influence into 16 different categories, divided in two subcategories. The life-cycle assessment reaserch review of the leadfree solders Sn-Cu, SAC (Sn-Ag-Cu), BSA (Bi-Sb-Ag) and SABC (Sn-Ag-Bi-Cu) respectively, is given in this paper, from the environmental protection aspect starting from production, through application process and finally, reclamation at the end-of-life, i.e. recycling. There are several opportunities for reducing the overall environmental and human health impacts of solder used in electronics manufacturing based on the results of the LCA, such as: using secondary metals reclaimed through post-industrial recycling; power consumption reducing by replacing older, less efficient reflow assembly equipment, or by optimizing the current equipment to perform at the elevated temperatures required for lead-free soldering, etc. The LCA analysis was done comparatively in relation to widely used Sn-Pb solder material. Additionally, the impact factors of material consumption, energy use, water and air reserves, human health and ecotoxicity have been ALSO considered including the potentials for dissolution and recycling processes.

The results of an investigation of the mechanism and kinetics of the oxidation process of synthetic α-NiS are presented in this paper. The mechanism of α-NiS oxidation was investigated based on the comparative analysis of DTA-TG-DTG and XRD results, as well as the constructed phase stability diagrams (PSD) for the Ni-S-O system. The kinetic investigations of the oxidation process were performed under isothermal conditions (temperature range 823-1073 K). The obtained degrees of desulfurization were used in the calculation process according to the Sharp model and the kinetic parameters, inclu­ding the activation energies and the rate constants of the characteristic reac­tions, for the oxidation of α-NiS were determined. These results enabled the formulation of a kinetic equation for the desulfurization process: -ln (1 − α) = = k1τ = 27.89 exp(-9860/T)τ, with an activation energy of 82±4 kJ mol-1, for the first stage of the process and -ln (1 − α) = k2τ = 1.177 exp(-4810/T)τ, with an activation energy of 40±2 kJ mol-1, for the second stage.

The results of calculations of the thermodynamic properties of liquid Ag-In-Sb alloys are presented in this paper. The Redlich-Kister-Muggianu model was used for the calculations. Based on known thermodynamic data for constitutive binary systems and available experimental data for the investigated ternary system, the ternary interaction parameter for the liquid phase in the temperature range 1000-1200 K was determined. Comparison between experimental and calculated results showed their good mutual agreement.

The results of the calculation of the thermodynamic properties for liquid Ga-Sb-Tl alloys at the temperature 1073 K are presented in this paper. Initially, the most appropriate thermodynamic model for the investigated system was selected. Based on a comparison of the values calculated by different geometric models (Kohler, Muggianu, Toop, Hillert, Chou) with the existing experimental based data, asymmetric models of calculation were determined to give the best results. The asymmetric nature of the investigated ternary system was additionally confirmed by the Chou similarity coefficient concept. For these reasons, further complete thermodynamic calculations were performed according to the Hillert model in five sections of the ternary Ga-Sb-Tl system from each corner with the mole ratio of other two components being 9:1; 7:3; 5:5; 3:7 and 1:9. The obtained results include integral excess Gibbs energy dependences on composition for all the investigated sections. The calculated activity values at 1073 K for all components are given in the form of isoactivity diagrams. Comparison between the calculated and experimentally obtained gallium activities shows good agreement.

The kinetics of realgar (As2S2) oxidation was studied under isothermal and non-isothermal conditions. The obtained values of the activation energy indicate that the process occurs in the kinetic domainwith the realgar particles being converted to As2O3 and As4O6 (g). The very fast reaction rates were limited by the chemical reaction. The kinetic equation was found to be: –ln (1–α) = 4.56 x 103 x e(–8780/T) x t. The proposed reaction mechanism and chemical transformation investigated by ICP–AES, EDXRF and thermal analysis are discussed.

In this paper, results of copper - lead matte investigations are presented. Investigated copper-lead matte is intermediate product of lead production in TREPCA-Zvecan. In the first part of the paper characterization of starting material is presented, consisting of: chemical composition analysis (XRQ), sceaning electron microscopy (SEM) and diffractometry (XRD). Thermal properties of matte investigated were determined using differential thermal analysis (DTA) at characteristic temperatures. Using results of induced analysis, mechanism of matte oxidation process was determined. In second part of the paper kinetic parameters describing oxidative roasting and afterwards leaching in sulfuric acid of copper-lead mate are presented.

The calculations of thermodynamic properties in some gallium-based systems with a miscibility gap – Ga–Tl, Ga–Hg and Ga–Pb are presented in this paper. The determination of the gallium activities in the mentioned liquid alloys was based on their known phase diagrams using the Zhang-Chou method for calculating activities from phase diagrams involving two liquid or solid coexisting phases. The activities of gallium in Ga–Tl, Ga–Hg and Ga–Pb system were calculated in the 973–1273 K, 573–873 K and 1000–1100 K temperature ranges, respectively. The activities of the other component in all the investigated systems were obtained by the Gibbs-Duhem equation. The results of the calculations are compared with literature data.

Thermodynamic properties of binary Ga-Pb alloys were investigated experimentally and analytically. Quantitative differential thermal analysis was used for determination of integral mixing enthalpies for the gallium-reach alloys, at the constant temperature inside the liquid two-phase region. Calculation of gallium activities in the temperature range of 800-1000 K was done using Chou’s calculation model developed for binary systems with miscibility gap existence.

EMF measurement of the electrochemical cell with zirconia as solid electrolyte was performed to determine the gallium activity from 950 to 1150K in the entire composition range of liquid Ga-Pb alloys. In the whole concentration range, activity of Ga shows moderately positive deviations from ideality, and activity of Pb which is derived by Gibbs- Duhem equation shows also positive deviation from ideality. These are compared with published data obtained by different experimental methods.

Calculations of activities in Ga-Cd and Cu-Pb binary systems were done based on their known phase diagrams, using different calculation methods. First, activities of cadmium at 700 K and copper at 1263 K in Ca - Cd and Cu - Pb systems, respectively, were calculated by melting point depression method and Zhang-Chou method for binary systems with phase diagrams involving two liquid or solid coexisting phases. In order to obtain activity values in the entire composition range, these methods were applied in the definite parts of composition range in both investigating systems. The same procedure was done, using modified Rao- Belton method by Chou, who used Richardson assumption. Activities of the second component in both investigating systems were calculated by use of Gibbs-Duhem equation. All calculated results were compared with literature data and mutual comparison between applied methods was done.

The results of thermodynamic analysis of arsenic, antimony and bismuth distribution between copper matte and discard slag in reverberatory smelting at 1573 K are shown in this paper. On the basis of chemical analysis of the melt samples taken during stable operation of the reverb furnace No.2 in the Copper Smelter and Refinery, RTB Bor (Yugoslavia), the distribution coefficients of As, Sb, and Bi between copper matte and slag are calculated. The influence of the matte grade on the minor element distribution coefficients between copper matte and slag is also analyzed, as well as arsenic, antimony and bismuth distribution in slag.

The results of the determination of the thermodynamic properties for ternary systems Cr.Co.Me (Me = Mo, Al) using a new general solution model for the predictions are presented in this work. For five sections (with mole ratio Co :Me = 2:8, 4:6, 5:5, 6:4, 8:2) investigated in each ternary system at temperature of 2000 K, integral molar excess Gibbs energies and partial molar thermodynamic properties of chromium were calculated.