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Powertrain of in-line five-cylinder spark ignition engine
Hájek, Daniel ; Rauscher, Jaroslav (referee) ; Píštěk, Václav (advisor)
Objective of bachelor’s thesis is, for noted geometric, thermodynamic and operation parameters cylindrical unit of five-cylinder spark-ignition engine, perform calculation of thermodynamic cycle, project basic proportion of piston group and for noted operation modes perform strength check of connecting-rod eye. Rated value verify, if corresponded with true value of spark-ignition engine. In preamble is stated basic use of spark-ignition engines, their operation principle and design concept. The bachelor’s thesis is consists from description of calculation and supplement, where is calculation done. The calculation is consists from three parts. The first part is calculation of thermodynamic cycle, in the second part are calculated forces reacting to piston group and third part is strength calculation and check of connecting-rod eye. In the last part is results evaluation of calculation, show a methods of calculation and a new trends spark-ignition engine of evolution.
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Increasing SI Engine Performance by Turbocharging
Hájek, Daniel ; Beran, Martin (referee) ; Svída, David (advisor)
The master’s thesis deals with the question of petrol engine boosting by rotary turbochargers. The objective of the thesis is to project suitable turbocharger for defined single-cylinder petrol engine. After selecting the suitable turbocharger type it will follow the construction of the computational model of the single-cylinder turbocharged petrol engine in the Lotus Engine Simulation software. In the computational model is boost pressure regulated by the turbine waste gate valve. The result will be the boost pressure values scheme for the highest possible torque so that the maximum combustion pressures will not exceed the value of 9,5 MPa. There are summarized findings and results in the conclusion of the thesis.
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Experimental study of recombination of astrophysically relevant ions with electrons
Hájek, Daniel ; Dohnal, Petr (advisor) ; Rednyk, Serhiy (referee)
Chemical kinetics model for preparation of H2D+ and HD2 + recombination was created. Model predicted, how the chemistry inside of the apparatus will develop so the best initial conditions for the measurement could be set. Quality of our created model was tested by comparison with previous measurements. Afterward, concentration of H3 + ions in discharge was measured using absorption spectroscopy. During this measurement the kinetic temperature of ions was calculated using Doppler broadening of spectral lines. This measured temperature was compared to the one measured by a temperature sensor positioned on the discharge tube holder. Then, three measurements to find the dissociative recombination rate of kation H3 + were done. These measurements were done on temperatures near 60 K and on pressures of 450 Pa and 550 Pa. When the coefficient was measured, ternary recombination rate was subtracted. The obtained binary recombination rate coefficient was compared to previous measurements and to theory. Our recombination rate, taking uncertainty in to account, well agreed with measurement and theory.
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A comparison of selected anthropological theories in view of their pragmatic value
Hájek, Daniel ; Vrhel, František (advisor) ; Jakoubek, Marek (referee)
The study deals with the problem of applicability of two anthropological theories, structural functionalism and interpretive anthropology of Clifford Geertz. By applicability is meant what concrete difference using of one or the other theory brings about in ethnography. Each of the theories is at first thoroughly examined with emphasis on its possible aims, assumptions, and consequences for an ethnographer. Then each theory is put to test in examination of one particular ethnography associated with the theory. Evans-Pritchard's The Nuer serves as an instance of structural functionalism. Clifford Geertz's Negara as an example of interpretative analysis. Structural functionalism is shown to provide an ethnographer with a much more definite guidance which contributes to better possibilities of verification and comparability of the results than interpretive anthropology. Apart from the main subject, the study is concerned with more general questions, especially related to non-existence of a paradigm in anthropology and some of its causes.
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Comparison of Spengler's and Kroeber's Visions of Culture.
Hájek, Daniel ; Vrhel, František (advisor) ; Korecká, Zuzana (referee)
The thesis compares the concepts of culture of German historian Oswald Spengler and American anthropologist Alfred Louis Kroeber. Both authors shared interest in comparative study of civilizations and similar approaches to it, based on an assumption, that culture is a distinct level of reality, nonreductible to its parts, but on the contrary controlling them. This conception is sometimes refered to as superorganic. Each of the scholars compared here hit upon the idea by other ways, hence it carries some different implications for them. The concepts and related methods are analyzed in this work with focus on revealing their assumptions. The explicit comparison is made in the end of the work. Powered by TCPDF (www.tcpdf.org)
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Study of electron - ion recombination in low temperature plasma using Cavity Ring-Down Spectroscopy
Hájek, Daniel ; Dohnal, Petr (advisor) ; Rednyk, Serhiy (referee)
A kinetic model of the behavior of ions and electrons inside the apparatus designed to measure the recombination coefficient of H3O+ was created. This kinetic model showed what the ideal initial conditions in the apparatus would be in order to study recombination of H3O+ in stationary plasma afterglow. The program designed to fit the development of the H3O+ concentration was also verified. The program was tested whether it would be able to fit the recombination coefficient with sufficient accuracy. This program was also tested on data that was artificially edited adding normally distributed noise. Furthermore, calibration measurements of the water source were performed, using cavity ring-down spectroscopy. This measurement verified whether we were able to get the required amount of water into the apparatus. The measurements were performed at three different pressures, at each of which we were able to receive enough water from the source to the apparatus so that the measurement could proceed well according to the kinetic model.
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Further education of teachers teaching physical education at elementary and high schools in the Czech Republic
Hájek, Daniel ; Flemr, Libor (advisor) ; Suchý, Jiří (referee)
Title: Further education of teachers teaching physical education at elementary and high schools in the Czech Republic Objectives: One of the aims of this diploma thesis was to analyse the current offer of accredited educational events DVPP (further education of educational workers) in the field of physical education. We were interested in data concerning the form and focus of events, hourly subsidy, number of expected participants, and participation fee. Another aim of this thesis was to find out what attitude teachers of physical education have in relation to their further continuous education. Among other things, we were interested in how often they participate in this education and what forms of educational events they find most suitable regarding the subject of physical education. Methods: In the first phase, the data obtained from the databases of granted accreditations in the DVPP system managed by the Ministry of Education, Youth and Sports, were analysed. The data in the next part were obtained using an own questionnaire survey, which elementary and high school teachers of physical education have participated in. A total of 700 schools were addressed (25 elementary schools and 25 high schools from all regions of the Czech Republic). Results: Most accredited educational events were focused...
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An overview of the programmes supporting physical activity of children at elementary schools in the Czech Republic
Hájek, Daniel ; Flemr, Libor (advisor) ; Peřinová, Radka (referee)
Title: An overview of the programmes supporting physical activity of children at elementary schools in the Czech Republic Objectives: The aim of the thesis is to sum up most of the programmes that strive to improve physical activity of children at elementary schools in the Czech Republic. This overview should help the scholarly public to get to know which programmes are there for the support of physical activity and their subsequent interest in them. Methods: In the first part, the programmes which meet the set requirements, were looked up. Following sources were used to find these programmes: the Internet, websites of the organisations engaged in children sport education, addressing coordinators of the programmes etc. The data in the next part of the thesis were acquired using a form of which participants were the employees connected to those stated programmes. In total, 329 schools were approached and ca. 32 % of questionnaires were returned. Results: Overall, eight programmes were found and seven of them actively engaged in improving physical activity of the children at elementary schools in the Czech Republic. Out of all active programmes only two focus on the first grade of elementary schools as well as on the second grade. The rest of them are intended only for first grade students. The...
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