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Symmetry Group Analysis of Suddenly Accelerated Flow Past a Flat Plate
Tesař, Václav
Modern symmetry group theory provides constructive procedures for finding similarity transformations and invariants, leading to fundamental change in the similarity solutions of shear flows, based so far on inspection analysis, ad hoc assumptions, and physical considerations. The new approach is here demonstrated on classical Stokes' (1851) problem of the suddenly accelerated flow above a stationary flat plate, with the gradual growth of boundary layer thickness.
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Slowly rotating sources around static black holes
Čížek, Pavel ; Semerák, Oldřich (advisor) ; Ledvinka, Tomáš (referee)
In this thesis we study the possibility of perturbative solution of the Einstein equations in the case of stationary and axially symmetric metric. The method is motivated by the pursuit of describing the astrophysically important system of a black hole surrounded by a thin disc or a ring. A Schwarzschild black hole is thus considered as a central source, with a light and/or slowly rotating disc around. We show that the metric can be found in terms of perturbative expansions in relative disc mass or in inverted distance from the hole, and point out where problems occur. The approach can be applied to a disc "given in advance" as well as in the "self-consistent" case when the disc elements orbit on circular geodesics in the desired total eld. It can also be generalised to the discs composed of more dust components.
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The Black and Red lists of the Giant Mountains flora: Do the extinct and endangered plants have common properties?
Blahník, Jan ; Čihař, Martin (referee) ; Krahulec, František (advisor)
A list of extinct and endangered species of the Giant Mountains was published in 2009, which presents a uniform view of vascular plants on the Polish and the Czech sides of the mountains. This Bachelor's Thesis is focused on the most endangered and the extinct species, for which common properties were sought, while it was not clear, whether such properties actually existed. The Bachelor's Thesis evaluates factors that could be traced in literature. Data concerning the type of propagation, which is of key importance for the maintenance of species, however, are not stated in literature for the absolute majority of cases. Easily traceable data concerned the properties of the subsoil, biotope types and properties, life form (was not eventually evaluated), phytogeographic areas, degrees of vegetation and endemism. It cannot be expected that a comparison of the results would show conformity anywhere in the region of 100%, yet certain signs of common properties can be deduced from some results. For example, for one-fifth to one-third of C1 and A1 category species a common property is an acid substrate, 30-40% of C1 category species occur in oreophytic areas, for some 30% of extinct and endangered species, the common sign is their occurrence in meadow sites, 30-40% of critically endangered species occur in...
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Analysis of the Lambing Process in Suffolk Ewes
ŠULCOVÁ, Veronika
The Suffolk is the most well-known of the English lowland sheep breeds. A black-faced sheep with short-stapled wool, the breed is used primarily for meat production. The Suffolk is classified as one of the breeds with the best ability to fatten and its meat yield is approximately 60%. The breed is characterised by its good adaptability to different climate and breeding conditions and overall good health. The ewes are known for their high fertility rate, shorter oestrus cycle, excellent maternal instincts, and high milk production. As a result of these characteristics, the Suffolk has become a very popular breed around the world. This thesis focuses on the breeding of Suffolk sheep as one of the best breeds for the production of slaughter lambs. The thesis also looks at reproduction as a part of sheep breeding, as well as at the factors that have an effect on pregnancy, the birthing process, and the newborn lamb. The main objective of this thesis was to process the lambing data for a specific herd of Suffolk sheep, including performing an evaluation of the basic reproductive indicators, calculating the birth weight of lambs, and determining the ideal age for including ewes in the breeding herd. The basic reproductive indicators include fertility, fertilisation, breeding intensity, and weaned lamb production. In the studied herd of sheep, these indicators were calculated as follows: fertility 182%; fertilisation 91%; breeding intensity 155%; and weaned lamb production 159%. The average birth weight of the lambs was 3.9 kg and the average optimal age for inclusion in the breeding herd was determined to be 17.5 months.
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Chaos in motion around black holes
Suková, Petra ; Semerák, Oldřich (advisor) ; Šubr, Ladislav (referee)
The geodesic motion around Kerr black holes is regular, but this may change when an additional source is present, even if the space-time symmetry were not lowered. In this thesis we study the eect of a simple (static and axially symmetric) additional source on geodesic dynamics in the eld of a Schwarzschild black hole. In the static case the complete space-time can be described by an exact solution of Einstein equations thanks to a relatively simple superposition of the central-black-hole and the external-source metrics. Following the astrophysical motivation, we will specically consider, as the external source, the thin ring (linear source) of the Bach-Weyl type and innite thin discs (planar sources) of several types (inverted counter-rotating discs of Morgan and Morgan and the discs with power-law radial shape of density). The results may be relevant e.g. for a long-term behaviour of discrete sources (stars) in the eld of a very massive black hole in a galactic nucleus, surrounded by an accretion disc and/or by a massive toroid.
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Callitrichidae - trade, captive breeding, distribution pattern
FOLEJTAROVÁ, Lucie
This work is focused on working with available information about biology, about conditions of population in free nature, about endanger and protection (mainly CITES, IUCN) of tribe called Callitrichidae. Then it valuates and elaborates the international trade based on information from the database CITIES during the years 1977 2013. Results are rated in case of business reasons, origin of specimen, structure of commodities, lands of import and export. Among the critical endagered species belong Leontopithecus caissara (Black-faced Lion Tamarin) with the estimated population in free nature of just only 400 pieces, Saguinus oedipus (Cotton-headed Tamarin) with the population in free nature about 6000 pieces. Trade with Common Marmoset (Callithrix jacchus), which is classified as not endangered, makes 81% of the trade. Mostly reasons of this trade are commerce, science, zoo and medical reasons since 1990s. Most of these pieces come from breeding in captivity and they are mostly samples and then living pieces. The biggest importers are USA and Switzerland. The biggest exporters are Germany and Great Britain. South Afrika is the biggest exporter of living pieces and Germany and Great Britain are the biggest exporters of samples.
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Children's View of Narration in Selected Pieces of Anglo-American Prose
BRABCOVÁ, Petra
The presented thesis focuses on the phenomenon of child narrator/protagonist in the role of the main actor and intermediary of fictional world in literature for adults. The first chapter is devoted mainly to the theoretical concept of narrator as a significant narratological category. The second chapter presents literature for children and youth in comparison to literature primarily intended for adult readers and looks for their mutual inspirations. Above all, the concept of children aspect is defined. In the practical part, the thesis aims for stylistic analysis, thematic interpretation and comparison of four narrative texts from Anglophone literature. These are The Bluest Eye by Toni Morrison, Black Swan Green by David Mitchell, Pigeon English by Stephen Kelman and Cormac McCarthy's The Road. These texts, having a child narrator/protagonist in common, are not primarily intended to be read by children. I see this as a certain strategy of writers, which however fully functions only in such a case, when the authenticity of child narrator/protagonist is maintained. Thus, such elements which we could connect with the concept of children aspect are deliberately used there. My objective is therefore to link the concept of children aspect with a specifically defined literature for adults. I also inquire why child narrators/protagonists are used in literature for adults and what their functions are, how and to what extent can a child narrator/protagonist convey fictional world, what the children in the followed texts are like, how the perceive the world around them, how they impart to us what they see, think and feel, and what possibilities of description of the world through a child's eyes it offers to authors.
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Transmission of sound pressure from a static source of sound
KAMARÝT, Jan
I chosed a packing machine as a static source of the sound for my mesurement of sound pressure. The machine was located in a potato warehouse owned by Agricultural company of Čechtice. At the first time I described the packing machine and then I described the entire packing process for better imagination how this machine works and where were the acoustic emissins coming from. The first practical part of this thesis was measuring sound preassure levels near around the machine and at the operator position. The second part of measuring was at the operator position and in some other places. This measurement took eight hours in each spot. Then I calculated equivalent values from the numbers and I measured and compared them with hygienic limits. I found out that there was no need to take steps to reduce noise, because the machine didn´t exceed the noise level.
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Distribution of wild cucumber, Echinocystis lobata Torr. et A. Gray, in the Hradec Králové region.
HOLEČKOVÁ, Veronika
The aim of this work was elaboration of known locations invasive liana Echinocystis lobata (Michx.) Torr. et A. Gray in Královéhradecký region, but completion of new locations from my own cross ? country research too. I have acquired 42 locations by literal excerption, three new locations by my own cross ? country research and next three locations by contacting several persons. Primary distribution area is in North America, but currently in the Czech Republic it takes place very fast, mainly off shores of rivers or brooks. From here this species is expanding to surroudings, first of all along water corse, on meadows and dust ? hole. I would like to show the reality how dangerous this species can be for natural habitats.
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Monitoring patient´s radiation load during mamograph screening
HÁJKOVÁ, Michala
The development of mammography equipment made it possible to reduce the amount of radiation necessary for mammography exams. On the other hand the demands on image resolution have been growing, which means that the average amount of radiation has actually increased. It is necessary to decrease the irradiation amount during screening as much as possible without jeopardising image quality. When using a modern mammography system, the medium dose of irradiation absorbed by the gland is approximately 1 {--} 1.5 mGy for each picture. Patients can undergo as many as 25 mammography exams in their lifetime and therefore it is necessary to reduce the irradiation to an acceptable minimum. In 1631 patients underoing mammography screening, the following relations for the cranio-caudal projection of the left Braest were evaluated: the dependence of a mean mammary gland dose on the compressed Brest thickness and on mAs. The largest group in the monitored set was between 50 {--} 54 years of age and the age of the mammography screening clients examined for the first time was between 45 {--} 49 years. In my work I recommended a program for the calculation of glandular irradiation, which is available on the Internet for free and I did not detect elevated ``diagnostic reference levels.{\crqq}
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