Physical Properties of Chocolate with Addition of Cocoa Butter Equivalent of Moderate Hardness

In this study, the fat phase of chocolate samples which contained cocoa butter from Ghana and cocoa butter equivalent (CBE) of moderate hardness was analyzed. Physical properties and shelf life of chocolate depend on the fat phase behavior as well as the amount and composition of added CBE. The laboratory-made chocolate samples were tempered at three different pre-crystallization temperatures (25, 27 and 29 °C), with three different concentrations of CBE, amounting to 3, 5 and 7 %, calculated on chocolate. The color and other physical attributes of chocolate samples were investigated by the following analytical methods: thermoreographic measurement, solid fat content (SFC) of chocolate, Blooming test (thermo-cycle test 32/20 °C) and color measurement. It was found that using CBE of moderate hardness did not change the melting properties of chocolate in relation to the investigated cocoa butter from Ghana (of moderate hardness). It was found that all three applied temperatures of pre-crystallization are optimum for the chocolate mass with the addition of the investigated CBE under the given measurement conditions. At all these temperatures, the chocolate had excellent fat bloom resistance.     

Potential contribution of bioethanol fuel to the transport sector of Vojvodina

The Autonomous Province of Vojvodina is an Autonomous Province in Serbia and it is an energy-deficient country. The indigenous reserves of oil and gas are limited and the country is heavily dependent on the import of oil. The oil import bill is a serious strain on the country's economy and has been deteriorating the balance of payments situation. The country has become increasingly more dependent on fossil fuels and its energy security hangs on the fragile supply of imported oil that is subject to disruptions and price volatility. The transport sector has a 26% share in the total commercial energy consumption in Vojvodina. About 0.62 million tons of gasoline were consumed by this sector in 2008. Gasoline consumption in the transport sector is also a major source of environmental degradation especially in urban areas. Consequently, Vojvodina needs to develop indigenous, environment-friendly energy resources, such as bioethanol, to meet its transport sector's energy needs. Vojvodina produces about 3 million tons of sugar beet every year. There is a vast potential for bioethanol production from molasses of sugar beet in the country. Bioethanol can be used in transport sector after blending with gasoline, in order to minimize gasoline consumption and associated economical and environmental impacts. This paper presents the assessment of the potential contribution of bioethanol in the transport sector of Vojvodina. It is concluded that 20% of annual gasoline consumption in transport sector could be met from ethanol by the year 2026.     

The effect of ageing temperature and time on the mechanical properties of Fe-NiCrMo alloys with different contents of δ ferrite

Laboratory cast alloys with 2–27% of δ ferrite were aged for up to 17,520 h in the temperature range 290–350 °C. Tensile and Charpy tests were performed at 22 and 290 °C on specimens aged for different times, and the microhardnesses of both constituents of the microstructure were determined for the alloy with 27% of δ ferrite. The effects of the content of δ ferrite, the ageing and testing temperature, and the ageing time on mechanical properties and notch toughness are presented and discussed.     

Characterization and quantification of folates produced by yeast strains isolated from kefir granules

For the first time to our knowledge, distribution and content of individual folate forms in kefir yeast strains were investigated. This was done using a validated method based on reversed-phase high performance liquid chromatography (HPLC) with fluorescence and diode array (DAD) detection. Eight kefir yeast strains, belonging to different Candida and Saccharomyces species, were isolated from Russian kefir granules. They were grown in synthetic media at standardized conditions before analysis. The average folate content for these yeast strains was 10,780±550 μg/100 g dry matter. In all yeast strains tested, the most abundant folate forms as percentages were 5-methyltetrahydrofolate (43–59%), and 5-formyltetrahydrofolate (23–38%), whereas tetrahydrafolate occurred in a lesser proportion (19–23%).     

Characterization of enzymatically synthesized amylopectin analogs via asymmetrical flow field flow fractionation

Asymmetrical flow field flow fractionation (AF4), when coupled with multi-angle laser light scattering (MALLS), is a very powerful technique for determination of the macromolecular structure of high molar mass (branched) polysaccharides. AF4 is a size fractionation technique just as size exclusion chromatography (SEC), nevertheless can overcome some crucial problems found in SEC analysis especially in starch like structures. This paper describes a detailed investigation of the macromolecular structure of two groups of well-defined synthetic amylopectin analogs – synthesized via an in vitro enzyme-catalyzed reaction using the enzymes phosphorylase b from rabbit muscle and Deinococcus geothermalis glycogen branching enzyme (Dg GBE). Size, molar mass distributions and structural data were studied by AF4 coupled with online quasi-elastic light scattering (QELS) and multi-angle light scattering (MALLS).     

Performance of Spectrum Sharing System in Gamma Shadowed Nakagami-<Emphasis Type="Italic">m</Emphasis> Fading Environment

In this paper, the performance of spectrum sharing system in composite Nakagami-m/gamma shadowed channels is analyzed. The environments (of primary and secondary users) corrupted only by noise or interference are considered in details. The novel analytical expressions for outage probability, moment generation function and ergodic capacity are derived in a form of fast-computable Meijer’s G functions, for both mentioned scenarios. Numerical results illustrate the impact of fading and shadowing phenomena on system performance, and appropriate comparison between noise- and interference-limited cases is presented.     

Residential satisfaction among young people in post-socialist countries: the case of Serbia

Change in labor markets, extended education period and economic instability are negatively influencing housing accessibility of young adults. In post-socialist countries, such as Serbia, the biggest issues are the lack of supply volume and diversity of government subsidized housing, as well as the soaring prices of the newly built homes. As a result, young people are relying on the unregulated private rental market or their families to help them enter homeownership and acquire residential independence. There is an apparent need for affordable housing or policies which are catering to young people’s needs. The relevant body of research has been using residential satisfaction approach to provide an evaluation of the variety of housing available to young tenants. Hence, the primary purpose of this paper is to identify the factors which are significantly related or can predict the higher residential satisfaction and can be beneficial to the future policy makers in Serbia. To assess the residential satisfaction, following variables were included: socioeconomic characteristics, residential status, current housing characteristics, problems faced in the current dwelling, housing attribute preferences, privacy perception, dwelling proximity, neighborhood attachment, as well as overall residential satisfaction. The findings indicate that young people in Serbia had average levels of satisfaction with their housing despite the various problems and lack of privacy they were facing in the apartments. Higher residential satisfaction in this research was significantly predicted by the marital status of our respondents (single people were more satisfied), homeownership tenancy status, independent living arrangement, larger apartment size, greater levels of privacy and higher neighborhood attachment.     

Association of toxic and essential metals with atopy markers and ventilatory lung function in women and men

The association of age, smoking, alcohol, superoxide dismutase (SOD), glutathione peroxidase (GPx), blood lead (BPb) and cadmium (BCd) levels, and serum levels of copper (SCu), zinc (SZn) and selenium (SSe) with atopic status and ventilatory function was examined in the groups of 166 women and 50 men with no occupational exposure to metals or other xenobiotics. Markers of atopy included serum total IgE, skin prick test (SPT) to common inhalatory allergens, non-specific nasal reactivity (NNR) and non-specific bronchial reactivity (NBR). Parameters of ventilatory function included forced vital capacity (FVC) and forced expiratory volume in the first second (FEV(1)). Significantly higher BPb, SZn, IgE and prevalence of positive SPT, and lower SCu and NNR was found in men than in women. Fifteen women taking female sex hormones (HT) had significantly higher SCu than women without HT. Regression models showed significant inverse associations between IgE and SCu (P=0.021) and NNR and SCu (P=0.044) in women. When excluding women with HT, the association of SCu and total IgE became of borderline significance (P=0.051), association between SCu and NNR disappeared, and significant positive association between total IgE and BPb emerged (P=0.046). In men, significant inverse association was found between positive SPT and SSe, and between NBR and SSe. A decrease in FVC% and FEV(1)% was associated with an increase in smoking intensity (P<0.001) and a decrease in SZn (P=0.043 and P=0.053, respectively). These results were observed at the levels of the metals comparable to those in general populations worldwide. The observed differences between men and women may partly be explained by different levels of relevant toxic and essential metals, and their combination. The role of female HT in associations of atopy markers and SCu should be further investigated.     

Radiochemical indoor environment and possible health risks in current building technology

Tremendous work of civil and environmental engineering has been focused on development of sustainable buildings. From economical and ecological viewpoint, this approach is a significant step forward, but the microenvironment created in such living surroundings may present a complex radiochemical setting, which could be a threat to the health of its occupants. This paper gives overview about levels of indoor radon, insight in risks related with radioactivity of fly ash and zircon, current application of nanoparticles and concrete additives in buildings and their possible impact on human health. As construction engineering is current producer of almost 50% of waste encouragement of incorporation of toxic and radioactive agents in buildings could in future demand redefinition of building construction waste as hazardous and special waste disposals. Collaboration between governmental and non-governmental bodies, manufacturers, scientific institutions, and chartered engineers is needed in order to find balance between quality of indoor air, and to enable maintaining of high health standards by application of non-toxic or non-carcinogenic building materials that meet energy efficiency, building structure stability and security requirements.