Rađanje van braka u Srbiji: nedovoljno istražen fenomen / Nonmarital Fertility in Serbia: An Under-Researched Phenomenon

U Srbiji je, kao i širom Evrope, u poslednjih nekoliko decenija prisutan trend porasta vanbračnog fertiliteta. U 2017. godini je van braka rođeno 26% dece. U radu se sagledavaju osnovne karakteristike vanbračnog rađanja, na osnovu zvaničnih statističkih podataka i rezultata kvalitativnog istraživanja autora. O tome koliko se vanbračnih rađanja odvija u okviru vanbračnih zajednica a koliko među samohranim majkama, usled nedostatka statističkih podataka, zaključuje se indirektno. Rezultati analize ukazuju na nepovoljan socioekonomski položaj mnogih majki i dece rođene van braka. Stoga se ukazuje na potrebu institucionalnih mera podrške jednoroditeljskim porodicama. Takođe, naglašava se potreba produbljivanja znanja i povećanje obuhvata i kvaliteta podataka vezanih za fenomen vanbračnih rađanja

Examining Mental Health and Well-being Provision in Schools in Europe: Methodological Approach

Schools are considered an ideal setting for community-based mental health and well-being interventions for young people. However, in spite of extensive literature examining the effectiveness of such interventions, very few studies have investigated existing mental health and well-being provision in schools. The current study aims to extend such previous research by surveying primary and secondary schools to investigate the nature of available provision in nine European countries (Germany, Ireland, the Netherlands, Poland, Serbia, Spain, Sweden, the UK and Ukraine). Furthermore, the study aims to investigate potential barriers to mental health and well-being provision and compare provision within and between countries

The effects of thermistor linearization techniques on the T-history characterization of phase change materials

Phase Change Materials (PCMs) are increasingly being used in the area of energy sustainability. Thermal characterization is a prerequisite for any reliable utilization of these materials. Current characterization methods including the well-known T-history method depend on accurate temperature measurements. This paper investigates the impact of different thermistor linearization techniques on the temperature uncertainty in the T-history characterization of PCMs. Thermistor sensors and two linearization techniques were evaluated in terms of achievable temperature accuracy through consideration of both, non-linearity and self-heating errors. T-history measurements of RT21 (RUBITHERM ® GmbH) PCM were performed. Temperature measurement results on the RT21 sample suggest that the Serial-Parallel Resistor (SPR) 1 linearization technique gives better uncertainty (less than ±0.1°C) in comparison with the Wheatstone Bridge (WB) 1 technique (up to ±1.5°C). These results may considerably influence the usability of latent heat storage density of PCMs in the certain temperature range. They could also provide a solid base for the development of a T-history measuring device. © 2012 Elsevier Ltd. All rights reserved

The potential of different plant species for nickel accumulation

Contamination of the environment with toxic heavy metals is a mayor environmental problem. Aimed to find effective and economical attractive solutions for environment cleaning, scientists intensively evolve various phytoremediation techniques. Nickel is one of the essential micronutrients for plants, animals, and humans, but toxic at elevated concentrations. Also, it belongs to a group of heavy metals. In respect of the fact that Ni uptake relies upon plant species and that some of them show hyperaccumulation effects, the aim of our study was to analyse Ni concentration in certain plant species affected by Ni contamination of air and surface soil. Ni deposition in the air was below 60 mu g/m(2)/month, while Ni content in the soil was between 42 and 150 mu g/g. Average Ni content in plants ranged from 0. 1 to 5. 0 mu g/g. Regardless the analysed locality, the highest Ni (7.1 mu g/g) was obtained with the hogweed, whereas the lowest (4.5 mu g/g) with the vines. Ambrosia artemis folia and Taraxum officinale accumulated the greatest amounts of Ni (10. 72 and 10. 61 mu g/g, respectively). It may be concluded that the analysed plant species exhibit various phytoremediation potential for Ni under the same ecological conditions

Photocatalytic activity of ZnO-PEO composites

The removal of organic pollutants from wastewater is very important for environmental protection. During the years different methods have been developed and applied on wastewater treatment. Between those methods a heterogeneous photocatalysis has received extensive attention since it allows a complete mineralization of pollutants. ZnO-based materials has established role in heterogeneous photocatalysis. However, major drawback of ZnO is a band energy gap of 3.37 eV (368 nm) which restricts the material to absorb only UV light. Since sunlight is a source of clean and cheap energy, where UV light makes no more than 3–5% while visible light is about 45% of the total sunlight, it is highly desirable to synthesize ZnO-based materials capable for visible light photocatalysis. To modify the optical absorption properties and improving the visible light photocatalytic activity of ZnO materials several approaches have been applied: (1) metal ion doping, (2) nonmetal doping, (3) defect induced doping, (4) surface sensitization of ZnO particles to extend the spectral response into the visible region, (5) band gap modification by creation of oxygen vacancies and oxygen sub-stoichiometry, etc. In this study, ZnO powder with nanospherical morphology was synthesized by microwave processing. In the continuation, the synthesized powder was used for preparation of composites with polyethylene oxide (PEO). PEO powders with three different molecular mass (200.000, 600.000 and 900.000) were used for composites preparation. The phase purity and crystal structure of the composites were investigated by X-ray diffraction and Raman spectroscopy. The particles morphology and size distributions were studied by FE–SEM and laser diffraction particle size analyzer, respectively. The optical properties were studied using UV–Vis diffuse reflectance and photoluminescence spectroscopy. The photocatalytic activity of ZnO-PEO composites was examined via decomposition of methylene blue (MB) under direct sunlight irradiation. A large efficiency of MB degradation was found after 6 h of irradiation. An enhanced optical and photocatalytical properties of ZnO-PEO composites were attributed to: (1) lattice defects introduced in crystal structure of ZnO by fast microwave processing, and (2) surface sensitization by polyethylene oxide (PEO)

Fazi relacijske jednačine i nejednačine i njihova primena u analizi podataka

The subject of this thesis is the development of algorithms for computing the greatest solutions to systems of fuzzy relational equations and inequalities and application of these solutions in the analysis of one-mode and multi-mode fuzzy social networks. In addition, some problems of finding structural similarities (regular equivalences) between the actors of various networks have been considered, and have been employed for determination of connected positions in these networks

Heavy metals in the leaves of tree species paulownia elongata syhu in the region of the city of Belgrade

Based on the analysis of the heavy metal content (Zn, Fe, Pb, Cu, Ni, Cr Mn, Cd, As, Hg) in leaves of the trees growing in the urban part of the city of Belgrade, wider city area and rural area it may be noted that the content of Fe, Pb, Ni, Cr and Cd increases going from rural to urban area. The obtained results may be related to the increased air pollution in urban and suburban areas where some of these heavy metals appear as a direct consequence of fuel combustion. The level of tolerance of the species Paulownia elongata S.Y.HU towards air pollution represents the basis for its development and survival in urban conditions as well as setting up of tree alleys and forming wind protection zones along main traffic lines

Metaphysical meaning of light in literary prose of Nikola Milošević; Метафизический смьсл светлости в художественной прозе Николи Милошевича

Никола Милошевић, знаменити професор Филолошког факултета Универзитета у Београду и редовни члан Српске академије наука и уметности, умро је, као што је познато, 24. јануара 2007. године. Радован Биговић је, поводом његове смрти, рекао да ће се његово огромно дело тек проучавати и да ће, као такво, сигурно бити предмет озбиљних научних студија и књига. Свако ко је слушао предавања Николе Милошевића или читао његове књиге осећао је и нехотице харизматичност његових речи. Вођени дивљењем према његовој личности и делу, и сами смо се упустили у истраживања извесних аспеката његовог дела. Напоредо са другим његовим делима, нашу пажњу све време привлачила је његова уметничка проза која обухвата, пре свега четири романа која је објавио...As it is known Nikola Milošević, a renowned professor at the Faculty of Philology, Belgrade University and a full member of Serbian Academy of Sciences and Arts, died on January 24, 2007. Upon the news of his death Radovan Bigović said that his immense work would yet to be explored and therefore he would be the topic of many studies and a lot of books. All those who attended the lectures of Nikola Milošević or have read his books could detect, though unintentionally, the charisma of his words. Inspired by his personality and his work, I have olso delved into studying certain aspects of his work. My attention has been primarily focused on his literary prose chiefly consisting of for novels published. Having read his own books and the books written on him, I got the impression that no one had examined the theme of light in his literary prose. It is doubtless that the theme deserves to be explored. I suggest that the title of the thesis should be Metaphysical Meaning of Light in Literary Prose of Nikola Milošević..

The Study of Capacitance Change during Electrolyte Penetration through Carbon-Supported Hydrous Ruthenium Oxide Prepared by the Sol-Gel Procedure

The changes in capacitive behavior of C/HxRuOy composite material prepared by impregnating the Vulcan® XC 72R carbon black with oxide sols of different particle size are investigated as the electrolyte penetrates through the thin layer of the Nafion®-covered composite. The techniques of cyclic voltammetry and electrochemical impedance spectroscopy are used. Results of the investigation reveal the influence of potential cycling and the exposure time to the electrolyte on registered capacitive characteristics of composite. The cycling in a wide potential range causes the decrease in energy storage ability which depends on oxide particle size. Impedance measurements, however, show that the ability initially decreases and subsequently increases during exposure to the electrolyte as the consequence of the presence of Nafion® top-layer. Due to wettability and resistance issues, Nafion® top-layer can affect the pseudo-capacitive characteristics, and the energy storage ability of the composite consequently decreases

Analiza prodrlog elektromagnetskog polja mobilnog telefona korišćenjem numeričkog modela dečije glave za različite mikrotalasne podopsege

The research work presented here was aimed at obtaining the new results related to the calculation of penetrated electromagnetic field from a mobile phone and its spatial distribution inside a child’s head. Several numerical models were developed for the purpose of investigating the effects of mobile phone radiation. A comprehensive 3D numerical model was developed, which corresponds to the anatomical and morphological properties of a seven years-old child head by size and shape. An adult head model was created for the purpose of examining the different effects of electromagnetic radiation on children and adults. Also, in line with the trend of increased use of mobile phones for internet access and viewing/reading of the content on the device display, a child eye model with appropriate anatomical and morphological characteristics was developed to match such use. The source of electromagnetic radiation has been created to match the shape of a contemporary smart phone, and it contains the housing with a display and the antenna. The research involved a simulation of operational conditions of the phone at several different frequencies – both at currently used and at upcoming 5G network frequencies. For assumed level of device output power, high values of electric field intensity and specific absorption rate (SAR), exceeding the allowed reference levels and base limitations were found in some tissues/organs inside the child head model. Higher than allowed electric field and SAR levels were also found for millimetre wave frequency ranges but they are concentrated in narrow layers near the very surface of the model, whereby the exceeding SAR level is even more noticeable. Higher values of electric field intensity and SAR are present in the child head model to a greater extent compared to the adult head model, due to anatomical and geometrical differences between child and adult head models. The research also shows that the morphological properties of children’s tissues and organs influence the increase of SAR values