CONCURRENT VALIDITY OF THE STUDENT TEACHER PROFESSIONAL IDENTITY SCALE

The main purpose of study was to examine concurrent validity of the Student Teachers Professional Identity Scale–STPIS (Fisherman and Abbot, 1998) that was for the first time used in Serbia. Indicators of concurrent validity was established by correlation with student teacher self-reported well-being, self-esteem, burnout stress and resilience. Based on the results we can conclude that the STPIS meets the criterion of concurrent validity. The implications of these results are important for researchers and decisions makers in teacher education

COMPARISON OF LINEAR AND NONLINEAR STATISTICS METHODS APPLIED IN INDUSTRIAL PROCESS MODELING PROCEDURE

This paper presents the comparison of Multiple Linear Regression Analysis (MLRA) and Artificial Neural Networks (ANN) as the statistical analysis tools. Most influential statistical parameters for choosing right modeling tool are evaluated in this investigation. Investigation was performed on real statistical data set obtained after measurements of the process parameters underindustrial conditions

Informisanost roditelja o značaju oralnog zdravlja dece predškolskog uzrasta - stavovi roditelja i socio-ekonomski status

Introduction: Oral health is closely related in several ways to the general health of each person. Certain habits, attitudes and behaviors related to oral health begin to form very early in the process of primary socialization, so that the family largely participates in their formation. The aim of this paper is to determine the correlation between parents' attitudes to the difficulties in the care of the teeth and the knowledge of the parents of preschool children about the importance of oral health and their socioeconomic status in Jagodina and Pirot. Methods: The research was designed as a cross-sectional study using the method of interviews with parents adapted for epidemiological research on the ground. The technique of surveying and scaling was used. The questionnaire was used as a research instrument, while the data on the oral health of the examined children were obtained by the usual dental examinations, according to the methodology of the World Health Organisation for pre-school children. Results: The highest coefficient b is 0.429, which is the value for the environmental variable. This single variable contributes most to explaining the dependent variable. A smaller b coefficient for the sex of the child (b=0.286) indicates a smaller contribution. The smallest contribution is made by the variables monthly income and family type. Statistically significant indicators of the correlation of parents' attitudes with educational and economic status of the parents (maternal education status and total monthly income) were obtained. Conclusion: Attitudes on the health of the mouth and teeth of the interviewed parents and their children are directly related to their health habits, attitudes and behavior: the presence of the risk of occurrence of oral diseases in children shows a high percentage expected in view of the health habits, attitudes and behavior of the parents, as well as their socio-economic status.Uvod: Oralno zdravlje je višestruko i tesno povezano sa opštim zdravljem svake osobe. Određene navike, stavovi i ponašanje u vezi sa oralnim zdravljem počinju da se formiraju vrlo rano, u procesu primarne socijalizacije, tako da porodica najvećim delom učestvuje u njihovom formiranju. Cilj ovog rada je utvrđivanje povezanosti između stavova roditelja o poteškoćama u nezi zuba i znanja roditelja dece predškolskog uzrasta o značaju oralnog zdravlja i njihovog socioekonomskog statusa u Jagodini i Pirotu. Materijal i metode: Istraživanje je oblikovano kao studija preseka, metodom intervjua sa roditeljima prilagođene za epidemiološko istraživanje na terenu. Korišćena je tehnika anketiranja i skaliranja. Kao instrument istraživanja korišćen je upitnik, dok su podaci o oralnom zdravlju ispitivane dece dobijeni uobičajenim stomatološkim pregledima, prema metodologiji Svetske Zdravstvene Organizacije za predškolsku decu. Rezultati: Najveći koeficijent b iznosi 0.429, što je vrednost za promenljivu životna sredina. Ova promenljiva pojedinačno najviše doprinosi objašnjavanju zavisne varijable. Manji b koeficijent za pol deteta (b=0.286) ukazuje na manji doprinos. Najmanji doprinos daju promenljive mesečni prihodi i tip porodice. Dobijeni su statistički značajni pokazatelji povezanosti stavova roditelja sa obrazovnim i ekonomskim statusom roditelja (obrazovnim statusom majke i ukupnim mesečnim prihodima). Zaključak: Stavovi o zdravlju usta i zuba anketiranih roditelja i njihove dece u direktnom su odnosu s njihovim zdravstvenim navikama, stavovima i ponašanjem: prisutstvo rizika za pojavu oralnih oboljenja kod dece u visokom je procentu očekivan s obzirom na zdravstvene navike, stavove i ponašanje roditelja, kao i na njihov socio-ekonomski status

Formation of Disperse Silver Deposits by the Electrodeposition Processes at High Overpotentials

In this study, electrodeposition of silver from nitrate solution at the high overpotentials was analyzed. Morphologies of silver deposits obtained at the different overpotentials and with the different electrodeposition times were examined using the technique of scanning electron microscopy (SEM). The different disperse morphological forms, such as granules, needle-like and spongy-dendritic ones were formed during silver electrodeposition from this solution. The size of granules decreased and their number increased with the increase of overpotential of electrodeposition. With the increasing overpotential, the induction time for the appearance of spongy-dendritic forms decreased with a tendency to increase their ramification. Mathematic model describing the mechanism of metal electrodeposition at the high overpotentials is proposed and discussed on the basis of the obtained silver surface morphology

TECHNOLOGICAL PROCESS MODELING AIMING TO IMPROVE ITS OPERATIONS MANAGEMENT

This paper presents the modeling procedure of one real technological system. In this study, thecopper extraction from the copper flotation waste generated at the Bor Copper Mine (Serbia), werethe object of modeling. Sufficient data base for statistical modeling was constructed using theorthogonal factorial design of the experiments. Mathematical model of investigated system wasdeveloped using the combination of linear and multiple linear statistical analysis approach. Thepurpose of such a model is obtaining optimal states of the system that enable efficient operationsmanagement. Besides technological and economical, ecological parameters of the process wereconsidered as crucial input variables

Variability of carbon emission factors from lignite of the Kostolac basin in time

This paper presents experimental tests of lignite from the Kostolac open-pit mine, used to operate the boiler of the Kostolac B2 thermal power plant in 2022. Experimental tests were conducted to determine the emission characteristics and carbon emission factor and compare these values with those taken and determined in 2016. A total of 31 samples taken in April 2022 were tested. As with our previous work, the experimental methodology includes proximate analysis, ultimate analysis and determination of calorific value, for the 'as received', 'as determined' and dry basis. Corresponding correlations were established for the tested Kostolac lignite. The emission characteristics of the Kostolac lignite from 2022 were compared with the corresponding values from 2016. Certain changes in the values of the carbon emission factor over time are a regular phenomenon and therefore periodic sampling and experimental determinations are inevitable to follow the changes in the values. For this change in coal properties, new values for the carbon emission factor are proposed, which should be used to calculate the total carbon dioxide emissions in the last period

Overpotential controls the morphology of electrolytically produced copper dendritic forms

The morphologies of copper dendritic forms obtained in both potentiostatic and galvanostatic regimes of electrolysis with various amounts of the electricity were analyzed by the scanning electron microscopy (SEM) technique. Irrespective of amount of passed electricity, 3D (three dimensional) pine-like dendrites with sharp tips were formed in the potentiostatic regime of electrolysis. On the other hand, the amount of passed electricity had a strong effect on the shape of the 3D pine-like dendrites formed in the galvanostatic regime of electrolysis. Dendrites with sharp tips were formed with smaller amount of passed electricity, while dendrites with globular tips were formed with larger amounts. The change in the shape of the galvanostatically synthesized 3D pine-like dendrites was explained by comparison with copper deposits obtained potentiostatically at overpotentials that corresponded to the final overpotentials during galvanostatic regime of electrolysis for the analyzed amounts of electricity. Based on the similarity of the obtained morphologies at the macro level, it was concluded that the overpotential plays a crucial role in the formation of the electrolytically synthesized dendrites and that the controlled conditions of electrolysis could represent a suitable way for a synthesis of spherical Cu particles by electrolysis

Numerical modeling of disperse material evaporation in axisymmetric thermal plasma reactor

A numerical 3D Euler-Lagrangian stochastic-deterministic (LSD) model of two-phase flow laden with solid particles was developed. The model includes the relevant physical effects, namely phase interaction, panicle dispersion by turbulence, lift forces, particle-particle collisions, particle-wall collisions, heat and mass transfer between phases, melting and evaporation of particles, vapour diffusion in the gas flow. It was applied to simulate the processes in thermal plasma reactors, designed for the production of the ceramic powders. Paper presents results of extensive numerical simulation provided (a) to determine critical mechanism of interphase heat and mass transfer in plasma flows, (b) to show relative influence of some plasma reactor parameters on solid precursor evaporation efficiency: 1 - inlet plasma temperature, 2 - inlet plasma velocity, 3 - particle initial diameter, 4 - particle injection angle a, and 5 - reactor wall temperature, (c) to analyze the possibilities for high evaporation efficiency of different starting solid precursors (Si, Al, Ti, and B2O3 powder), and (d) to compare different plasma reactor configurations in conjunction with disperse material evaporation efficiency