9 research outputs found
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The impact of atmospheric boundary layer, opening configuration and presence of animals on the ventilation of a cattle barn
Naturally ventilated livestock buildings (NVLB) represent one of the most significant sources of ammonia emissions. However, even the dispersion of passive gas in an NVLB is still not well understood. In this paper, we present a detailed investigation of passive pollutant dispersion in a model of a cattle barn using the wind tunnel experiment method. We simulated the pollution of the barn by a ground-level planar source. We used the time-resolved particle image velocimetry (TR-PIV) and the fast flame ionisation detector (FFID) to study the flow and dispersion processes at high spatial and temporal resolution. We employed the Proper Orthogonal Decomposition (POD) and Oscillating Patterns Decomposition (OPD) methods to detect the coherent structures of the flow. The results show that the type of atmospheric boundary layer (ABL) and sidewall opening height have a significant impact on the pollutant dispersion in the barn, while the presence of animals and doors openings are insignificant under conditions of winds perpendicular to the sidewall openings. We found that the dynamic coherent structures, developed by the Kelvin-Helmholtz instability, contribute to the pollutant transport in the barn. We demonstrate that in any of the studied cases the pollutant was not well mixed within the barn and that a significant underestimation (up to by a factor 3) of the barn ventilation might be obtained using, e.g. tracer gas method. © 2020 The Author
Study of antioxidant and antimicrobial properties of grapevine seeds, grape and rosehip pressing
In our experiment, we studied the antimicrobial and antioxidative effect of phytogenic additives. Three additives (grapevine seeds, grape and rosehip pressings) were selected to be monitored. The extracts about concentrations of 1:3 and 1:5 were prepared from them. The monitoring of antimicrobial properties was focused on the pathogenic bacteria Clostridium perfringens and Escherichia coli causing a serious disease in avian species. The bacteria were prepared in the dilutions of 102, 104 and 106. The antimicrobial effect was observed in the inhibition zones. The antioxidant activity was determined using DPPH method within the antioxidant analysis. Furthermore, the content of flavanols, hydroxycinnamic acids and the total content of polyphenolic compounds was also determined. In the monitoring of the antimicrobial effect of grapevine seeds, grape and rosehip pressings at E. coli, a reduced growth of KTJ (colony forming units) was observed in the disk area during the dilution of 106 and 104. Reduced growth of C. perfringens at a dilution of 106 was noticed using the extracts of grapevine seeds and grape pressings. Low reduced growth of C. perfringens at a dilution of 106 was found out using rosehip pressings. In a dilution of 102 and 104 in C. perfringens and 102 in E. Coli, a very low increase of KTJ was observed therefore the zones of inhibition were not possible to measure. In all monitored additives, the antimicrobial effect was proved. The additives reduced the growth of pathogenic E. coli and C. perfringens. Within the antioxidant analysis, the highest antioxidant activity was found out in grapevine seeds (7.021 g.L-1 GAE), which also contained the highest content of flavanols (3000 times higher than the rosehip pressings and 300 times higher than grapevine seeds pressings), hydroxycinnamic acids (1000 times higher than in grape pressings and 7600 times higher than in rosehip pressings) and the total content of polyphenolic compounds (580 times higher than grape pressings and 2000 times higher than the rosehip pressings) of the monitored additives
Influence of garlic extract on antioxidant status of chicken
In 2006 the European Union banned the feeding of antibiotic growth promoters because of possible risk of drug resistance in human pathogens bacteria. This is the reason for the study of various phytogenic additives and their extracts as a natural source of biologically important compounds. Antimicrobial substances are a commonly included in chicken feed rations. They are used mainly as prevention against various diseases, and also to stimulate growth. The beneficial effects of garlic on animal organism resulting from their antimicrobial, antioxidative and antihypertensive properities. Studies focused on growth, conversion and meat quality of different types of animals indicate its positive effects. In our experiment we studied the influence of garlic extract in a dose of 0, 10 g and 15 g per 1 kg of chicken feed mixture. We focused on weight gains and antioxidant status of an organism. The experiment took 39 days. 54 seven-day-old chickens were included in the experiment. The chickens were weighed once a week, when aged 11, 17, 24, 31 and 38 days, at the same time of the day. The chickens had ad libitum access to feed ration and water. The chickens were taken blood sample at the end of the experiment when 39 days old. Their antioxidant status were measured using ABTS, FRAP and DPPH methods. Our results show that owing to higher concentration of garlic extract in feed ration the antioxidant status of observed chickens was increased. DPPH method showed an increase in antioxidant status of both experimental groups by 38% (a group with a dose of 10 g/kg of mixture) and by 46% (a group with a dose of 15 g/kg of mixture) compared to the control group. When using FRAP method, antioxidant status of both G10 and G15 groups increased by 24%, resp. 16%. No evidential differences in antioxidant activity between the experimental groups and control group were found using ABTS method. The supplement of garlic extract into a feed ration did not have any influence on weight gains of chickens. © 2014 Potravinarstvo
Effect of chamomile supplements to feeding doses on antimicrobial parameters in poultry
Due to a ban of use of antibiotic growth promoters in the poultry industry it is necessary to look for alternative solutions. The use of some herbs showing antimicrobial effects can be one of such alternatives. In this experiment, effects of three different concentrations of chamomile (Matricaria chamomilla) extract, (0.3%; 0.6% and 1.2%) in feeding doses on the microbial population in the gastrointestinal tract of growing broiler chickens were studied. The main attention was paid to the population of Clostridium perfringens and to numbers of coliform microbes. Clostridia were cultivated under anaerobic conditions at 46 °C on the Tryptone Sulfite Neomycin (TSN) agar for a period of 24 hours. Coliform microbes were grown on the violet red bile lactose (VRBL) agar at 37 °C for a period of 24 hours. The experiment lasted 39 days and involved 80 chicks that were slaughtered in the course of their growth period at the age of 18, 25, 32 and 39 days; there were 5 chicks in each group. The obtained results indicated that increasing doses of chamomile in the feeding ration decreased numbers of coliform microbes in the digestive tract of chicks and also reduced the population of C. perfingens. © 2014 Potravinarstvo
Proceedings of the 12th International Conference on Kinanthropology
Proceedings of the 12th Conference of Sport and Quality of Life 2019 gatheres submissions of participants of the conference. Every submission is the result of positive evaluation by reviewers from the corresponding field. Conference is divided into sections – Analysis of human movement; Sport training, nutrition and regeneration; Sport and social sciences; Active ageing and sarcopenia; Strength and conditioning training; section for PhD students
Group Physical Activities during the After-School Program
Závěrečná práce se zaměřuje na rozšíření nabídky aktivního trávení volného času, ovlivnění postojů k pohybovým aktivitám u žáků ve školní družině a jejich životního stylu. Teoretická část práce objasňuje význam pohybu v životě člověka. Popisuje, jak lze rozvíjet pohybové dovednosti, jakými jsou bruslení a míčové hry, a sociální dovednosti u dětí mladšího školního věku. V naplánovaném projektu jsou popsány konkrétní příklady cvičení a her realizovaných v bloku bruslení a bloku míčových her. Tyto hry jsou vhodné pro rozvoj základních pohybových dovedností žáků mladšího školního věku, pomáhají k nácviku seberegulace, zvládání stresu, úspěchu i neúspěchu. Projekt rozšiřuje nabídku volnočasových aktivit na základní škole, poskytuje pedagogům další prostor pro rozvoj sociálních dovedností žáků, možnost rozvoje mezitřídních vztahů a vazeb a v neposlední řadě též nabízí další možnosti pro podporu vnitřní motivace žáka. V závěru je zhodnocena realizace projektu, zásadně ovlivněná uzavřením škol na jaře 2020 v souvislosti s pandemií Covid-19.This thesis focuses on enhancing the variety of active leisure time activities and influencing attitudes to physical activities of students within specific school groups and their lifestyles. The theoretical part of the work clarifies the importance of movement in daily life. It describes how movement skills such as ice skating, ball games and social skills can be developed in younger school-age children. The planned project describes specific examples of exercises and games implemented in the ice skating and ball game sections. These games are suitable for the development of basic movement skills in younger school age pupils, they help to practice self-regulation, stress management, success and failure. The project expounds the offer of leisure activities at the primary school level, provides teachers with additional framework for the development of pupil's social skills, the possibility of developing interclass relationships with social ties and, last but not least, offers other opportunities to support the pupil's internal motivation. In the end, the implementation of the project and it's evaluation was fundamentally affected by the closure of schools in the spring of 2020 in connection with the Covid-19 pandemic
Flow structures stability analysis in a model of a cattle barn using oscillating pattern decomposition method
A model of a cattle barn and a part-depth atmospheric boundary layer were scaled down to 1:50 to simulate the natural ventilation in a wind tunnel. We studied the impact of three opening configurations (entirely, half and quarterly open, which represented 0.7, 0.35 and 0.17 wall porosity, respectively), on the mean flow and the stability of the flow structures in the barn using time-resolved PIV technique and oscillating pattern decomposition method (OPD). While we observed the most-energy-containing structures (POD modes) in the case of the half opening, the most stable structures (OPD modes) correspond to the fully open case. We found that the stability of the structures increases with the opening width (wall porosity), and the highest frequency of these structures was 11 Hz