Authors:I. Mitrović, J. Grahovac, J. Dodić, A. Jokić, Z. Rončević, and M. Grahovac
The surplus of waste glycerol, by-product of the biodiesel production process, is available at the global market. Some species of the genera Streptomyces have the ability to assimilate glycerol and convert it into valuable metabolic products. In the present study, the ability of Streptomyces hygroscopicus to assimilate waste glycerol and convert it into metabolic compounds with antifungal activity against four phytopathogenic fungi obtained from apple fruit samples expressing rot symptoms, was investigated. Production of antifungal metabolites by S. hygroscopicus was carried out in 3 l stirred tank bioreactor through 7 days. Fermentation was carried out at 27 °C with aeration rate of 1.5 vvm and agitation rate of 100 r.p.m. The aim of this work was to analyse bioprocess parameters and to determine at which stage of bioprocess the production of antifungal metabolites occurs. Activity of the cultivation liquid on two isolates of Alternaria alternata and two isolates of Fusarium avenaceum were determined every 12 h using in vitro well diffusion method. It was found that the maximum production of antifungal metabolites occurred at 108 hour of cultivation. Formed inhibition zones have shown that the produced antifungal metabolites have high efficacy on tested phytopathogenic fungi (inhibition zone diameter higher than 35 mm for all test organisms).
Due to the shift in consumer behaviour, the proportion of well informed, conscious consumers has been growing steadily, and functional foods with their capacity to protect health have been gaining more and more ground. To achieve market success in the field of functional foods, producers should be able to communicate information effectively concerning health issues and their newly developed product should indeed meet consumer expectations. The aim of our study was to identify and define the components of the dimensions of consumer attitudes in Hungary together with the barriers and motivators of health behaviour. Our research also examined how these factors influence consumer willingness to consume functional foods. Our surveys were carried out in focus groups of health-conscious (n=8) and not health-conscious (n=8) consumers. Our findings confirmed the adequacy of the international dual model, regarding the attitudes of Hungarian consumers towards functional food. Moreover, we also explored the most popular health food categories and sources of information on nutrition.
Authors:A. Kumar, J.P.S. Gill, J.S. Bedi, and P.K. Chhuneja
Indiscriminate use of antibiotics in apicultural practices may lead to contamination of otherwise healthy and naturally produced honey. Contamination not only affects honey quality but also pose significant health risks to consumers. In this context, one hundred raw honey samples from India were analysed for presence of antibiotic residues. For determination of oxytetracycline and erythromycin, high performance liquid chromatography and for chloramphenicol, enzyme immunoassay based validated procedures were used. Oxytetracycline and erythromycin with concentrations above maximum tolerance limits were detected in 24% and 2% samples, respectively. None of the samples contained chloramphenicol residues. Although, total dietary intake of detected antibiotics through honey was found to be <1% of their acceptable daily intake values, the presence of antibiotics in honey is an alarming health concern for people following customary honey feeding. The outcomes underline the need of inter-sectoral approaches to create awareness among beekeepers regarding health risks associated with residues of antibiotics in honey and merits of approved apicultural practices. Therefore, to meet global food safety requirements, continual residue monitoring schemes along with enlightenment of beekeepers on scientific beehive management and risks associated with incautious apicultural practices are of vital importance.
Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.
Authors:Kristóf Roland Horváth and István Kistelegdi
First Hungarian Active House refurbishment won the Active House Award and the Energy Globe Hungary prize in 2017. This paper provides insight into the renewal design process of the typical home from the 70’s under disadvantageous site conditions. Dynamic thermal simulations helped to gain insight into space organization and building envelope concepts and their effects on comfort and energy performance. The Active House Standard was applied to evaluate the calculation results. The most advantageous concept was selected for final design elaboration and construction. The implemented building proved that in the refurbishment process it is possible to achieve highest level of efficiency in operation energy consumption with positive yearly balance by simultaneously being able to rearrange the complete interior space and as a consequence the building shape and envelope into a competitive design at international level.
During sketch design stage for the new block of the University of Pécs, Medical School comfort and lighting simulations were applied to quantify optimization strategies. Simulation cases about shading possibilities, façade glazing ratios and internal heat storage masses evaluate the impact of illumination, solar gains, loads and heat transmission on visual and thermal comfort. The goal was to select the most favorable comfort, coupled with maximum reduction of investment costs. Concepts represent 14% (shading), 10% (reduced wall-window ratio), 11% (slabs without suspended ceilings), and 17% (combined wall-window ratio and thermal mass) improvement in thermal comfort performance, and it was proposed for further design.
The aim of the research is to make a comparison between system integrated measurement technologies in the field of engineering education in order to the students getting more detailed knowledge about the high level problem solving. A comparative case study was conducted with 3 different types of systems, as follows: Beckhoff, National Instruments, and HBM. The criteria of the systems are determined based on experience and the importance level of them was calculated by preference matrix. The ranks of the alternatives are calculated by Kesselring method, which provides the effectiveness value of the systems compared to the benchmark. The result of the paper shows a suitable method for selecting engineering systems.
Authors:Boubekeur Djail, Walid Khaled Hidouci, and Malik Loudini
In wireless sensors networks, data are sensed and recorded as databases, and then acceded by relational queries. Joins are queries that are largely used. Joins collect data from several nodes’ table. These are operations that typically consume a lot of energy because they generate a large number of messages in the network. Researchers worked to decrease this consumed energy. Many strategies were proposed in this way, but most of them addressed only binary joins. N-way joins received few interests. N-way joins perform join operations between more than two tables. They cause greater energy consumption. Additionally, the number of execution order is very important; it grows exponentially with the number of considered tables.
Authors:Zuzana Németová, Silvia Kohnová, and Romana Marková
Regional flood frequency analysis is considered to be an important and popular method for estimating different hydrological variables at ungauged sites. The estimation of the index flood is the essential problem when this method is applied. The objective of the study is a comparison of the estimation of the mean annual flood (or index flood) by using two approaches based on the ‘so-called’ index flood method and top-kriging. The concept behind these methods permits estimating the mean annual flood at ungauged locations using information taken from gauged sites located within the same homogeneous pooling groups. The study area comprises 104 gauging stations on the whole territory of Slovakia. The observation period of the annual maximum discharges of the selected stations was from 1961-2010. The identification of the homogeneous pooling group was performed using a non-hierarchical k-means clustering algorithm. The optimal number of clusters is determined by the Silhouette method. As a result, eight homogeneous pooling group clusters were identified. Finally, the results of the estimated mean annual floods using the index flood method and top-kriging were compared with the observed data. Top-kriging provided better results than the classical index flood method for estimating the mean annual flood at ungauged sites.
This paper presents a design procedure of a switched-mode power converter, the well-known synchronous buck converter: the calculating method, and how to choose the parts of the converter are presented in detail, like the inductor, the capacitor and the semiconductors as well as the design of the state feedback. During the design process the efficiency and the high switching frequency are very important: the switching semiconductors are Gallium Nitride based. Then, a linear-quadratic regulator is designed and applied to the particular case of a buck converter.