Dietary habits of Serbian preschool and schoolchildren with regard to food of animal origin

The goal of this study was to explore attitudes and habits of Serbian preschool and school children in consumption of meat products, milk and milk products, eggs and egg products and honey and bee products. The survey was conducted on a sample of 227 children, divided into three different age groups: preschool (ages 4-6), primary school I-IV grade (ages 7-11) and primary school V-VIII grade (ages 12-15). The results showed that all examined groups of children consumed meat products, milk and milk products, eggs and egg products, and honey and bee products. In all groups of children, the most frequently consumed food (among our food category choices) was dried ham (consumed by 19.64% of preschool children; 23.75% of schoolchildren from I-IV grade; 19.74% of schoolchildren from V-VIII grade). Fewer preschool children consumed sterilized milk compared to children of school age. The results showed that in all three groups of children, the most commonly consumed milk products were yoghurt (from 12.20 to 15.29% of children consumed these) and sour cream (from 11.57 to 12.74% of children consumed this), while kefir was the least-consumed product. In addition, there was no difference in consumption of boiled or fried eggs in the examined groups of children, while the consumption of egg products (mayonnaise) was higher in the group of preschool children than in the group of schoolchildren from V-VIII grade. Preschool children consumed honey 14.99% more often than schoolchildren from I-IV grade, and 14.49% more often than did schoolchildren from grade V-VIII

Preservation of meat and meat products using nanoencapsulated thyme and oregano essential oils

Among other plants, thyme and oregano are commonly used in Mediterranean cuisine, especially in meat dishes. Although the essential oils of these two plants possess great antimicrobial and antioxidative properties, their application as natural meat preservatives are limited due to hydrophobicity, sensitivity to external factors and interaction with food components. Furthermore, essential oils can have adverse impacts on meats organoleptic properties. A possible way to overcome these barriers is by incorporating essential oils into nanometric delivery systems. Nano-sizing essential oils increases their stability, protects them, and allows their controlled release. This enhances the bioavailability of the essential oils and reduces their possible adverse impact on meat products organoleptic properties by preventing their unwanted interactions with food components. The antibacterial and antioxidative effect of nanoencapsulated essential oils is confirmed in numerous studies, and some of them show that in this form, essential oils were potent in food models e.g. beef burgers, pate and rainbow trout. However, a more promising way to introduce nano forms of essential oils into foods is incorporating them in packaging systems

Chemical Analysis of Mortars of Archeological Samples form Mediana

The aim of this study was mineralogical and chemical analysis of mortar from the floor, ceiling and wall of Stibadium B, from the archaeological site of Mediana. ICP-OES and FTIR-spectroscopy were used to determine chemical composition and some major mineralogical species. The obtained results show that lime mortar is probably used. Large contribution of silicon- and aluminum-oxides, indicate the presence of quartz and clay minerals derived from the aggregate, river sand and crushed bricks. The obtained results also show large amount of iron, manganese and copper. The determinated metals in samples from floor and wall of Stibadium B, are mostly present in oxide fraction, while in sample from ceiling, they are mostly found in silicate fraction

determining the reliability function of the thermal power system in power plant "nikola tesla, block b1"

Representation of probabilistic technique for evaluation of thermal power system reliability is the main subject of this paper. The system of thermal power plant under study consists of three subsystems and the reliability assessment is based on a sixteen-year failure database. By applying the mathematical theory of reliability to exploitation research data and using complex two-parameter Weibull distribution, the theoretical reliability functions of specified system have been determined. Obtained probabilistic laws of failure occurrence have confirmed a hypothesis that the distribution of the observed random variable fully describes behaviour of such a system in terms of reliability. Shown results make possible to acquire a better knowledge of current state of the system, as well as a more accurate estimation of its behavior during future exploitation. Final benefit is opportunity for potential improvement of complex system maintenance policies aimed at the reduction of unexpected failure occurrences

Electrical Characteristics of Ho doped BaTiO3 Ceramics

In this paper, electrical characteristics of Ho2O3 doped BaTiO3 ceramics were shown, using new method for measuring samples. The BaTiO3 doped samples were sintered at 1320°C for 4 hours. The concentration of the additives were from 0.05 to 1.0 at% Ho. The density was ranged from 83% to 91% of theoretical density (TD). The samples of BaTiO3 ceramics doped with Ho2O3 are characterized by spherical and irregular polygonal grains. The average grain size for samples doped with low content of Ho2O3 (0.05 at% Ho) ranged from 10 μm to 30 μm. An increase in dopant concentration causes a decrease in the average grain size in the investigated samples. So it is for samples doped with 1.0 at% Ho, grain size range between less than 1 mm – 2 mm. The variation of dielectric permittivity with temperature were measured in the temperature range from 30°C to 180°C and the frequency range from 100 Hz to 1 MHz. For measurement electrical characteristic a new method was used, which implemented to automate the sampling and to enable measurement without a human factor. The software application is connected via USB communication to a microcontroller, which measures the temperature in the furnace. When the temperature reaches the defined value, the microcontroller sends information to the software application. Then the application through GPIB communication activates the LCR meter, which measures the defined parameters of the tested samples. Based on parameters such as dielectric constant (εr), tangent losses (tan δ) and impedance, the characteristics of the tested samples were determined. Using the Curie-Weiss law and modified Curie-Weiss law, based on the measured values of the parameters, the Curie constant and the exponent of nonlinearity were determined

determining the reliability function of the thermal power system in power plant "nikola tesla, block b1"

Representation of probabilistic technique for evaluation of thermal power system reliability is the main subject of this paper. The system of thermal power plant under study consists of three subsystems and the reliability assessment is based on a sixteen-year failure database. By applying the mathematical theory of reliability to exploitation research data and using complex two-parameter Weibull distribution, the theoretical reliability functions of specified system have been determined. Obtained probabilistic laws of failure occurrence have confirmed a hypothesis that the distribution of the observed random variable fully describes behaviour of such a system in terms of reliability. Shown results make possible to acquire a better knowledge of current state of the system, as well as a more accurate estimation of its behavior during future exploitation. Final benefit is opportunity for potential improvement of complex system maintenance policies aimed at the reduction of unexpected failure occurrences

The Socio-economic Nature of Small Farms

In this article, the essential socio-economic characteristics of small peasant farms are discussed. Among these characteristics, first place is given to the close relationship between the small agricultural farm and the family to which it belongs, a certain specific symbiosis which causes this farm to develop according to different principles than other economic units. Small, peasant farms are by their socio-economic essence of an expressly uncapitalistic nature. Their uncapitalistic nature is seen in the incentives with which their owners approach the production process as well as in the financial results materialized, the criterium of judged realized success on the farm, and other principles by which economic activities are managed. Although they possess a specific means of production, small peasants do not view any factor of production with the eyes of a capitalist. The negligible surface of land of which they have use they do not consider a source of land rent but rather a necessary field for the application of their labor. The modest capital which they have at their disposal does not serve them to realize profits in order to hire labor but instead, along with the application of their own labor, to provide the essential needs for their family’s existence. Managing by the force of their own labour, the small peasants do not judge results of the production process objectiyely, that is, on the basis of invested productive labour plus the time and energy involved, according to net revenue, but instead only according to productive labour, that is, to the achievement of some newly created value-income. K. Marx had already pointed to the peculiar manner, of evaluating success and achieved results in the production process of small peasants when he emphasized that despite the great individual value of the agricultural products from small farms, these products do not necessarily even contain the cost of production, even less the value of production and that, in contrast with farms managed in a capitalist manner, do not create an absolute land rent. In addition to this classical conception of land rent, a new, modified conception is advanced in this article by which even in small peasant agriculture, some form of absolute land rent exists which comes from titular ownership of land. The author also points to a new understanding of the problem of expanded production on small peasant farms and to other changes. But, despite significant technological and social changes, these farms have, nevertheless, maintained their uncapitalistic character

Determining reliability functions of steam turbine in power plant 'Nikola Tesla, block a4'

Determination of reliability indicators of steam turbine system in the thermal power plant 'Nikola Tesla, Block A4'during useful life period is based on a ten-year operational database. By implementation of mathematical theory of reliability to exploitation research data and using simple and complex two-parameter Weibull distribution, the theoretical reliability functions of the considered system are determined. The graphical method is applied to quantitatively determine reliability indicators. Obtained probabilistic laws of failure density and failure rate, according to which the random variable behaves, do not coincide completely with empirical distributions, regardless of whether the theoretical functions are obtained by simple or complex Weibull distribution