In vitro antioxidant activity of honeydew and multifloral types of honey from Serbia

Antioxidant properties of fifteen multifloral and honeydew types of honey from Serbia were assessed by determination of ferric-reducing antioxidant power (FRAP assay) and 2,2- diphenyl-1-picrylhydrazyl free radical scavenging ability (DPPH assay), with respect to their total polyphenol content and colour intensity. The results of this study showed that total polyphenol content, antioxidant activity and colour intensity varied widely among different samples, even within the same type of honey. All investigated parameters were strongly dependent on geographic origin of samples, further emphasizing the importance of their detailed chemical characterisation. In general, polyphenolic content in investigated samples of honey, expressed as catechin equivalents, ranged from 480.2 to 1861.1 mg/kg. The ferric-reducing antioxidant power of honey tended to be lower in brighter and higher in darker samples, varying between 489.6 and 3089.8 μmol Fe(II) per 100 g of honey. The correlation between the colour and antioxidant activity never reached statistical significance in the case of honeydew type of honey, which was opposed to a trend observed in the case of multifloral honey. [Projekat Ministarstva nauke Republike Srbije, br. 143012

Administrativno-teritorijalna organizacija i lokalna samouprava u Vidovdanskom ustavu

The subject of research in the doctoral dissertation „Administrative-territorial organization and local selfgovernment in the Vidovdan Constitution“ is the process of normative constitution of the Yugoslav model of local self-government and its territorial organization in the period from the Vidovdan Constitution in 1921 to the establishment of the Januar 6 dictatorship in 1929. The research is structured through six thematic units in which the factors that influenced the building of local self-government and its administrative-territorial component during the third decade of the XX century in the Kingdom of Serbs, Croats and Slovenes are analyzed in a scientifically based way. The research was conducted in a broader socio-political context in order to gain and clearer picture of the determination of individual groups that took part in the constitutional and legislative process. An overview of the various political options in the Constituent Assembly and their mutual relationship is given because in that political prism and should look for the basis on which the Vidovdan Constitution and later legislation were built. The concept of local self-government established by the Constitution, is the result of the ideological orientation of the ruling parties, the Radical and Democratic, and attractiveness of the Frenc model and which the state exercises strong control over local authorities. The review of the constitutional debate, first in the Constitutional Committee, and then in the Assembly, aims to point out the process of partial evolution in certain issues and the factors that influenced the final formation of the administrative-territorial organization and principles of local self-government in the Constitution. The last chapter of the dissertation is dedicated to the analysis of the regulations of the Decree on the division of land into areas, the Law of General Administration, nad the Law on Regional and District Self-Government, which implemented the Vidovdan Constitution in one of its key segments. The reasons that led to the introduction of regional self-government only in 1927 are especially explained. The intention of the constitution-maker and legislator in the Kingdom of Serbs, Croats and Slovenes to influence the overall integration of the Yugoslav populacion through the adopted concept of administrative-territorial division and local self-government runs through the entire research

Correlation Between Morphology and Structure of Galvanostatically Electrodeposited Tin Dendrites

Tin dendrites found wide application in various industries.1 They can be obtained by both non-electrochemical and electrochemical methods of synthesis. In this study, they were produced by a galvanostatic regime of electrolysis from alkaline hydroxide solution at a current density of –3 mA cm–2 , 1.5 times larger than the limiting diffusion current density, with an amount of the electricity of 200 and 400 mC. In the dependence of an amount of the passed electricity, Sn dendrites of various morphology and crystal orientation were obtained: the fern-like dendrites predominantly oriented in (220), (440) crystal planes are obtained with 200 mC and the spear-like and the dendrites with prismatic branches showing the strong (200),(400) preferred orientationwere obtained with 400 mC. The strong correlation between morphology and structure of Sn dendrites is established and it can be explained by analysis of chronopotentiometry response obtained at the given current density and by morphological and structural analyses of Sn dendrites obtained by a potentiostatic regime at cathodic potentials corresponding to values attained after the passed amount of the electricity of 200 and 400 mC. The chronopotentiometry response after spent 200 mC was dominantly in the (–1600 – 1740) mV vs. Ag/AgCl range, and the fern-like dendrites with the strong (220), (440) preferred orientation were obtained in this potential range. After spent 400 mC, the chronopotentiometry response was about –1200 mV vs. Ag/AgCl, and the spear-like and the dendrites with prismatic branches with the strong (200),(400) preferred orientationwere obtained at this cathodic potential

Attitudes of Consumers from Educons University toward Advertising through Sport among the Question how Often they Participate in Sports Activities

This research was aimed at gaining relevant knowledge about the attitudes of Educons University consumers toward advertising through sport among the question how often they participate in sports activities. The sample included 200 students from Faculty of sport and tourism in Novi Sad, divided into six subsample groups: consumers who do not participate in sport activities at all, then consumers who participate in sport activities less than ones a month, next 1–4 a month, 5–10 a month, 11–20 a month, as well as consumers participate in sport activities more than 20 times a month. The sample of variables contained the system of three general attitudes which were modelled by seven-point Likert scale. The results of the measuring were analyzed by multivariate analysis (MANOVA) and univariate analysis (ANOVA) and Post Hoc test. Based on the statistical analyses it was found that significant differences occur at multivariate level, as well as between all three variables at a significance level of p=.000. Hence, it is interesting to highlight that it was found there are significant differences showed up between the consumers who participate in various sports activities. The significant differences were found in one of three variables, while the consumers who participate less than 4 times a moths had much more negative attitudes toward advertising though sport

Attitudes of Consumers from University of Novi Sad toward Advertising through Sport among the Question how Often they Participate in Sports Activities

This research was aimed at gaining relevant knowledge about the attitudes of University of Novi Sad consumers toward advertising through sport among the question how often they participate in sports activities. The sample included 168 students from Faculti of Sporth and Physical Education in Novi Sad, divided into six subsample groups: consumers who do not participate in sport activities at all, then consumers who participate in sport activities less than ones a month, next 1–4 a month, 5–10 a month, 11–20 a month, as well as consumers participate in sport activities more than 20 times a month. The sample of variables contained the system of three general attitudes which were modelled by seven-point Likert scale. The results of the measuring were analyzed by multivariate analysis (MANOVA) and univariate analysis (ANOVA) and Post Hoc test. Based on the statistical analyses it was found that significant differences occur at multivariate level, as well as between all three variables at a significance level of p=.000. Hence, it is interesting to highlight that it was found there are significant differences showed up between the consumers who participate in various sports activities. The significant differences were found in one of three variables, while the consumers who participate less than 4 times a moths had much more negative attitudes toward advertising though sport

Design of PtSnZn Nanocatalysts for Anodic Reactions in Fuel Cells

In order to achieve widespread application of fuel cell technology, the development of an efficient and economical catalyst is a crucial step. Reducing the diameter of catalyst particles, producing particles with a specific orientation surface, and alloying noble metals with less expensive metals are possible approaches to improve catalyst performance. This study will be focused on novel ways for creating PtSnZn catalysts that are more effective for the anodic reactions in fuel cell such are methanol, ethanol and formic acid oxidation reactions. PtZn and PtSnZn nanoparticles were produced using the microwave assisted polyol method and were supported on high surface area carbon Vulcan XC-72R material. The electrochemical behavior of synthesized catalysts was investigated utilizing the cyclic voltammetry, chronoamperometric technique, and electro-oxidation of adsorbed CO. To determine the catalyst's physicochemical characteristics, X-ray diffraction (XRD), transmission electron microscopy analysis (TEM), and thermogravimetric analysis (TGA) were used. High catalytic activity of the PtSnZn/C catalysts was achieved thanks to the benefits of microwave synthesis and carefully adjusted metal alloying

Residual life estimation of a thermal power plant component: The high-pressure turbine housing case

This study focuses on the estimation of residual life of damaged thermal power plant components. The high-pressure turbine housing was chosen as an example of thermal power plant component where, during the years of exploitation, damage appeared in the form of dominant crack. Residual life estimation procedure, based upon experimental and numerical methods has been introduced and applied. Material properties were determined experimentally both at room and operating temperature, while all necessary calculations were performed by the special finite element method, so-called X-FEM. The residual life estimation of the damaged high-pressure turbine housing was performed by applying the Paris's law for crack growth analysis

Influence of Ni2+/Co2+ ratio in electrolyte on morphology, structure and magnetic properties of electrolytically produced Ni−Co alloy powders

Nickel−cobalt (Ni−Co) alloy powders were produced galvanostatically by using sulphate electrolytes with various ratios of Ni2+/Co2+ (mole ratios). The morphology, phase structure, chemical composition and magnetic properties were examined by scanning electron microscope (SEM), X-ray diffractometer (XRD), atomic emission spectrometer (AES), and SQUID-based magnetometer, respectively. Morphology of the particles changed from cauliflower-like and dendritic to coral-like and spongy-like ones with increasing Ni2+/Co2+ ratio from 0.25 to 4.0. XRD analysis of the Ni−Co powders revealed that the decrease of Ni2+/Co2+ ratios (the increase of Co content) caused a change of structure from face centered cubic (FCC) obtained for the ratios of 4.0, 1.5 and 0.67 to a mixture of FCC and hexagonal closed-packed (HCP) phases for the ratio of 0.25. The increasing content of nickel led to change of mechanism of electrolysis from irregular (up to ~40 wt.% Ni in the electrolytes) to close to equilibrium (between ~40 and 60 wt.% Ni in the electrolytes) and anomalous co-deposition (over 60 wt.% Ni in the electrolytes) type. All of the obtained Ni−Co alloy samples behaved as soft magnetic materials while their magnetic parameters showed immediate composition dependence since both coercivity and saturation magnetization almost linearly increased with increase of the Co content

Machinability assesment procedure of superalloys

Postupak ocene obradljivosti superlegura mašinskom obradom je postupak u kome se primenjuju tri kriterijuma obradljivosti: ocena obradljivosti preko postojanosti alata, ocena obradljivosti preko temperatura pri mašinskoj obradi rezanjem i ocena obradljivosti na osnovu oblika i stepena deformisanosti strugotine. Za određivanje ovih ocena korišćeni su eksperimentalni podaci dobijeni snimanjem toka habanja alata, merenjem temperatura u zoni rezanja i određivanjem vrednosti faktora sabijanja strugotine pri obradi superlegura na bazi nikla IN-100 i MAR-M247.The machinability assessment procedure of superalloys is a procedure in which three machinability criteria are applied: machinability assessment based on tool stability, machinability assessment based on cutting temperatures and machinability assessment based on the shape and degree of chip deformation. To determine these assesments, experimental data obtained by recording tool wear process, measuring temperatures in the cutting zone and determining the value of the chip compaction factor when processing nickel-based superalloys IN-100 and MAR-M247 were used.Broj prijave: П-2021/0356Podaci o nosiocu prava: INSTITUT ZA NUKLEARNE NAUKE „VINČA“ – INSTITUT OD NACIONALNOG ZNAČAJA ZA REPUBLIKU SRBIJU, UNIVERZITETA U BEOGRADU (CENTAR ZA SINTEZU, PROCESIRANJE I KARAKTERIZACIJU MATERIJALA ZA PRIMENU U EKSTREMNIM USLOVIMA-CEXTREME LAB), Mike Petrovića Alasa 12-14, 11351 Beograd-Vinča, RSPriznati datum podnošenja prijave: 18.03.202

Correlation of Morphology and Crystal Structure of Metal Powders Produced by Electrolysis Processes

In this review paper, morphologies of metal powders produced by the constant (potentiostatic and galvanostatic) regimes of electrolysis from aqueous electrolytes are correlated with their crystal structure at the semiquantitative level. The main parameters affecting the shape of powder particles are the exchange current density (rate of electrochemical process) and overpotential for hydrogen evolution reaction. Depending on them, various shapes of dendrites (the needles, the two-dimensional (2D) fern-like, and the three-dimensional (3D) pine-like dendrites), and the particles formed under vigorous hydrogen evolution (cauliflower-like and spongy-like particles) are produced by these regimes of electrolysis. By decreasing the exchange current density value, the crystal structure of the powder particles is changed from the strong (111) preferred orientation obtained for the needle-like (silver) and the 2D (lead) dendrites to the randomly orientated crystallites in particles with the spherical morphology (the 3D dendrites and the cauliflower-like and the spongylike particles). The formation of metal powders by molten salt electrolysis and by electrolysis in deep eutectic solvents (DESs) and the crystallographic aspects of dendritic growth are also mentioned in this review