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Abstract

Tendencies of foodborne outbreaks show that the number of illnesses caused by Campylobacter spp. has been increasing recently in the European Union and in Hungary as well. However, the epidemiological statuses of Member States are diverse. There are several aspects to be investigated by competent authorities before the introduction of interventions. Methods supporting food safety decision making range from quick and easy techniques to complex, resource consuming approaches. The aim of the present study was the implementation of an evaluation and ranking system for a risk and its causes occurring in the broiler production chain. Data and information available in scientific literature were converted to a structured easy-to-use evaluation that supports decision making and helps structured data processing.

Open access

Abstract

The aim of this research was to assess the consumer habits of lactose sensitive persons in case of lactose-free products and their other shopping aspects for development of new, dairy-based lactose-free products. The research was based on face-to-face questionnaire survey, and those who declared to be lactose sensitive were analysed. Among them, only half of the women (49.3%) and one third of the men (34.6%) were medically proven lactose sensitive, so more than half of the respondents declared themselves affected on the basis of self-diagnosis. Our results show that reliably regular customers of lactose-free products are women and persons with medical diagnosis, high educational degree, and under the age of 30. The lactose-free consumer group prefers the following product features: lactose-free label; rich in calcium, vitamins, and fibre, and free of carbohydrate, sugar, and gluten. Only two-thirds of lactose sensitive customers (66.7%) consume lactose-free products regularly, so it can be assumed that the level of knowledge of this disease, its treatment, and the importance of lactose-free dairy products among these persons is insufficient. This could be solved with education, advertisement, and other information opportunities.

Open access

Abstract

Mathematical methods take an important part in reconstruction technologies of radiographic image. Back projection, iterative, and analytical (Two-dimensional Fourier, Filtered Back Projection) methods are the most important procedures for image reconstruction. Whenever there exists numerous projections, analytical methods have a great performance in speed and accuracy and due to these advantages they are comprehensively used for X-ray imaging. One of the widespread used methods in tomographic image reconstruction is Filtered Back Projection (FBP) algorithm. This paper presents an application of this reconstruction algorithm for a generated image of the object. Shepp-Logan filter is used to form the filtered back projection image and performance improvement is investigated. The obtained images indicate that FBP algorithm can be substantial for various applications in the field of medicine and industry.

Open access

Abstract

The aim of this research was to study the effect of micro- and industrial scale malting on the folate content of barley. Two malting barley varieties (one spring and one winter) were studied, applying the same technology. Furthermore, a roasting experiment was carried out at given temperatures for different time periods. The total folate content was determined by microbiological method. The folate content of the barleys was between 10.1 and 23.4 µg/100 g dry matter. For micro- and industrial scale, malting folate content increased 6.5–8-fold and 4–7-fold, respectively, during the malting process. An unexpected result was observed during industrial malting: the folate content increased during kilning by 18–35%, unlike micro scale malting, where a 15–20% decrease was observed. Results obtained during roasting showed that folic acid content did not decrease when roasted for 20 min at 100 °C, but it decreased linearly with increasing temperature. Folate is completely degraded in 20 min at 200 °C. It can be stated that barley malt can serve as a relatively good source of folate, but barley variety and malting technology have significant impact on it.

Open access
Pollack Periodica
Authors: Mohammad Reza Ganjali Bonjar, Kristóf Roland Horváth, Bálint Baranyai, and István Kistelegdi

Abstract

The purpose of this research is the application of a passive design strategy for office buildings, the wall-window-ratio optimization under moderate climate. A simplified thermal and lighting simulation model of an office research building served as reference testbed for thermal comfort, daylight factor and illuminance as well as heating, cooling and lighting energy demand assessment. These six performance types of similarly oriented room groups are evaluated via a self-developed weighting process to determine the orientation dependent optimal wall-window-ratio of all room groups. This multi objective optimization applies in a broad range of office buildings under moderate climate.

Open access

Abstract

The objective of this study was to use matrix-assisted laser desorption ionisation–time of flight mass spectrometry (MALDI-TOF MS) for the identification of ovine-associated staphylococci. Presumptive Staphylococcus isolates were recovered from ovine udder surface (US), individual raw milk, bulk tank milk, and cheese samples and were characterised by conventional phenotypic methods. A total of 69 bacterial isolates were further confirmed by MALDI-TOF MS. Forty-two (60.9%) of 69 isolates were successfully identified on genus and species level. Two thirds (n = 28) of the 42 identified isolates were shown to be Staphylococcus spp. These 28 staphylococcal isolates formed two clusters, one consisting of 22 Staphylococcus aureus strains and the other composed of 6 non-aureus staphylococci, including S. simulans (n = 3), S. auricularis, S. equorum, and S. haemolyticus. MALDI-TOF MS has proven to be a reliable tool for the identification of staphylococci from raw sheep's milk, especially bulk tank milk; however, currently it appears to be less useful for the identification of bacterial isolates originating from ovine US samples. This is the first study to evaluate the applicability of MALDI-TOF MS for identification of Staphylococcus spp. in ovine raw milk, cheese, and US samples in Hungary.

Open access

Abstract

The efficiency of the most modern photovoltaic cells currently reaches 40–45%, which is achieved by concentrator systems. However, despite better device efficiencies concentrator photovoltaic cells have major drawback, namely the high amount of waste heat, which requires new cooling solutions.

This paper gives a short overview of the current cooling techniques and proposes a novel microchannel cooling solution for concentrator photovoltaic cells. In the concept, the microscale channels are integrated into the backside metallization of the PV device. The paper gives a description of the technological process that can be used to produce microchannels on the back of solar cells and shows the optimization of the channels to achieve optimal cooling performance.

Open access

Abstract

Nowadays, digital technology and measurement are improving to measure some systems in accurate conditions without errors. From these improvements and developments, it is necessary to analyse performances and condition of bicycle and biker before high level computations. In this experimental investigation, a high quality and very light bicycle and a well-equipped trained biker were trained to test the system with different road and region conditions. The purpose of this investigation is to predict unwanted conditions of bicycle before computations and activity. Otherwise, this kind of experimental trained testing will give some information from unwanted bicycle accidents. Moreover, in this experimental work, a power meter and measurement instrument with sensors are used to measure real time parameters. As can be concluded from experimental results and the analysis, the proposed work has a good design and analysis for good material bicycles. The displacement analysis is also outlined with load of a 63 kg biker.

Open access

Abstract

Presence of pathogenic strains of Escherichia coli in foodstuffs may pose a health risk for a consumer. Therefore, knowledge on the effect of environmental factors on the growth ability of E. coli is of great importance. In this work, the effect of incubation temperature (6–46 °C) and the combined effect of temperature and water activity (0.991–0.930) on the growth dynamic of E. coli PSII were analysed. Based on the growth curves obtained, growth parameters were calculated by using the Baranyi D-model. Growth parameters were further analysed in secondary phase of predictive modelling. Using the CM model that describes the effect of combined factors, cardinal values (T min = 4.8 ± 0.4 °C, T opt = 41.1 ± 0.8 °C, T max = 48.3 ± 0.9 °C, a wmin = 0.932 ± 0.001, and a wopt = 0.997 ± 0.003) for the isolate were calculated. Under optimal conditions, the specific growth rate is µ opt = 2.84 ± 0.08 h−1. The results obtained may contribute to the assessment of the risk associated with the possible E. coli presence in raw materials and to the search for preventive measures with defined degree of accuracy and reliability.

Open access

Abstract

A numerical simulation procedure is presented to predict residual stress states in multi-pass welds in oil transportation pipes. In this paper, a two-dimensional thermo-mechanical finite element model is used to calculate the temperature distribution, hardness, and the distribution of residual stresses during multi-pass welding of pipes of dissimilar metals and varying thicknesses. In this model, the temperature dependence of the thermal and mechanical properties of the material was considered. The present model was validated using the hardness measurement. Good agreement was found between the measurement and the numerical simulation results. The simulated result shows that the two-dimensional model can be effectively used to simulate the hardness test and predict the residual stress in the pipe weld. The simulation results and measurements suggest that the model with moving heat source can obtain a good prediction of residual welding stress. Both the two-dimensional and the three-dimensional modeling can be used to estimate the residual stresses in different weld regions and help saving time.

Open access