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History and current Situation of Winter swimming in Czechoslovakia and Bohemia
Řehulka, Filip ; Miler, Tomáš (advisor) ; Parkan, František (referee)
Title History and current Situation of Winter swimming in Czechoslovakia and Bohemia Goals To Gather availlable informations on the historical development of hardening as swimming in our country. Using the literature related to winter swimming, completed by medical literature. Method A historical method is used to capture the history of hardening in Czechoslovakia and Bohemia in chronological order. The main goal of this method is displaying whole in its main features for better and clearer understanding of this topic. Results Complete fragmented history of the winter swimming in our country and provide a more detailed view of the meaning of the hardening. Key words Hardening, History, Swimming, Winter swimming
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A transcriptomic-based comparison of barley cultivars differing with respect to their low temperature acclimation capacity
Janská, Anna ; Ovesná, Jaroslava (advisor) ; Vaňková, Radomíra (referee) ; Honys, David (referee)
The PhD thesis is focused on a transcriptomics-based comparison of barley cultivars differing with respect to their low temperature acclimation capacity, with a particular focus on genes transcribed in the leaf and crown. The crown was of interest because of its importance for the winter survival of the plant. To involve both the first and the second phase of hardening, the test plants were exposed first to +3řC for 21 days, followed by - 3řC for one day. Freezing damage was assessed by measuring electrolyte leakage (Papers 2 and 3), using a modified version of a protocol developed by Prášil and Zámečník (1998). The same protocol was adapted to evaluate crown regrowth (Paper 2); for this purpose, the plants were cooled, then replanted and cut above the crown, and their survival rate calculated over the following week. Each RNA sample was queried by hybridization to an Affymetrix 22 K Barley1 GeneChip Genome Array (Close et al. 2004). The data were statistically analysed with the help of the software packages R, MAS 5.0 (Ihaka & Gentleman 1996) (Papers 2 and 3), Gene Spring GX 7.3 (Agilent Technologies, Santa Clara CA) and MapMan (Thimm et al. 2004; Usadel et al. 2005) (Paper 2), the "Self-Organizing Maps" algorithm (Kohonen et al. 1996) (Paper 3) and MIPS FunCat (Ruepp et al. 2004) (Paper 2). Paper...
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Heat treatement of gear steels
Šnevajs, Matěj ; Řehořek, Lukáš (referee) ; Jan, Vít (advisor)
This bachelor thesis deals with suitable types of heat and heat-chemical treating of case hardening steel for production of gear wheels. The experimental part focuses on examination of two specific gear wheels made of 14 224 and ZF1A steel, which were donated by the company TATRA TRUCKS a.s. This bachelor thesis presents results of their hardenability, microstructure, hardness and microhardness of the case hardening layer.
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Optimalisation of heat treeatment of steel - 27MnCrB5-2
Černín, Jiří ; Němec, Karel (referee) ; Věchet, Stanislav (advisor)
This bachelor’s thesis deal with heat treatment of bor steel, 27MnCrB5-2. The work contains assessment and further proposal of new suitable form fot heat treatment. With request for the most possible hardness and preservation optimal scale of tenacity and reasonable price. Teoretical part describes basic information about heat treatment. In the practical part was investigate sttructure, hardness and chemical composition of six samples.
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Analysis of cracking of aluminium profiles during bending process
Kalivoda, Ondřej ; Šebek, František (referee) ; Vosynek, Petr (advisor)
The presented thesis was created in cooperation with Siemens, s.r.o. and deals with the analysis of the bending of aluminium sheets. These products are used as conductors of electrical energy. The problem happened when the bending angle was 90 ° when there was a violation outside of the bend. The aim of the thesis is to verify whether the bend is correctly designed using analytical and empirical relations and the finite element method. Because of the requirement for running numerical simulation on one of the freely available software the Salome Meca program environment was used. The results of numerical simulation did not confirm that the violation should occur. In deeper analysis appeared doubts whether it is possible to correctly evaluated result only by data from tensile test. In the final part, there are recommended some experiments which would be necessary for the correct calibration of the ductil fracture criteria.
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Tube Flaring Technology under Dynamic Conditions
Macháček, David ; Forejt, Milan (referee) ; Peterková, Eva (advisor)
This master thesis is divided into three main parts. In first part is more closely described the method of tube flaring. Tube flaring was chosen for analysis of biaxial stress, in this thesis particularly in the presence of high strain rate. In the second part is more closely described influence of high strain rate on the forming process. There is described influence of high strain rate on behavior of the material, hardening, change of quasi-static yield strength to the dynamic yield strength, influence of high strain rate on the microstructure and more. During the description of these processes there is effort to describe the cause of these changes as well. For this task was used domestic and foreign literature, as well as peer review papers whose authors study intensively this problematic. Besides all of the above there is also derived the velocity of elastic and plastic wave. In the end is evaluated experiment, in which was done tube flaring, which is part of this master thesis. Results from the 3D optical system ARAMIS are interpreted with the help of Microsoft Excel, where the chosen results were used as the input to the equations modified for the dynamic loading.
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Methods of secondary influencing steel and steel ingot structures
Šprta, Pavel ; Pernica, Vítězslav (referee) ; Blažík, Petr (advisor)
This bachelor’s thesis deals with heat treatment of steels. Iron-carbon diagram and basics of heat treatment are described in the beginning of the literature search. Further the thesis focuses on austenitization and changes during decomposition of austenite. Introduction to transformation diagrams and their use is also included in this thesis. At the end the thesis focuses on description of individual heat treating methods. The experimental section contains metallographic analysis of 4 samples made of low carbon steel.
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The Study of Productions Operation Management
Petřek, Martin ; Kouřil, Karel (referee) ; Jurová, Marie (advisor)
The thesis dwells about methodics of processing an order in the company: Hardening shop Frydrych s.r.o. while respecting all the demands on the technological process of thermal and thermo-chemical manipulation as annealing, tempering and cementing. On the bases of the analyse and documental procedures the thesis is unraveling a concept for elimination of absences in the sphere of processing the order also as booking, invoicing and evaluating.
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Low Temperature and Cryogenic Treatment of Casehardened Parts
Bílková, Lenka ; Juliš, Martin (referee) ; Kouřil, Miloslav (advisor)
This work deals with the assessment of the influence of low-temperature treatment on the structure and properties of casehardened surface layer of parts. The objective was to assess whether low-temperature treatment is sufficient, insufficient, or unnecessary for the given purpose. Gears which form a part of Zetor tractors gear boxes were used as samples. Thirteen pairs of frozen and non-frozen samples were used; they were taken from production batches throughout 2007, their hardness was assessed and furthermore, the experiment itself, freezing casehardened and hardened samples to different temperatures reaching as low as -196°C, was carried out. A moderate increase in hardness was registered with the majority of the frozen samples, which proved the effectiveness of the low-temperature treatment.
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