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Analysis of friction welding by SFW process
Šajkovics, Patrik ; Mrňa, Libor (referee) ; Kubíček, Jaroslav (advisor)
Bachelor thesis developed in the bachelor study focuses on the analysis of friction welding by SFW process. The work is focused on a detailed description of the principle of technology SFW and its other modification. It describes the microstructure of the welds and it depends on the mechanical properties. Were summarized advantages and disadvantages, industries which the SFW used, suitable materials for welding and material of welding tools. SFW technology is focused on non-ferrous metals and their alloys, but the conclusion is also mentioned steel welding technology SFW and material of tools are suitable.
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Weldability of steels for steam turbine parts
Jech, David ; Hutařová, Simona (referee) ; Juliš, Martin (advisor)
The aim of contemporary standard welding technologies is to create compact welds with high value of solidity and toughness in laboratorial and operational conditions. This welding technology is asserted in new creep - resisting steels on basis of steel CrMoV and CrMoNiV, which have high value of solidity and creep - resistance. The thesis deals with problems connected with the weldability of steels for steam turbine rotors and it´s aim is to interpret the structural and mechanical features of the weld joint for material combinations under consideration. For the assessment of weld joint features has been used measuring of micro hardness and hardness according to Vickers, microstructure was observed by methods of light microscopy.
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Preparation of bioceramic materials for medical applications
Doboš, Petr ; Šoukal, František (referee) ; Palou, Martin (advisor)
The aim of this work was to prepare hydroxyapatite powder by sol-gel and precipitation method. Then, the powders were pressed and sintered at 500 °C, 800 °C and 1100 °C. These samples of HAP were analyzed by FTIR, XRD, SEM methods. The microstructure measurement by SEM indicates that the size HAP particles varies from micro to nano meter. The average size of dominant particles is determined around 5 – 8 µm with surrounding fine particles of 1 µm size. The in vitro bioactivity of HAP samples was investigated by immersing them in Simulated Blood Fluid for 4 weeks. The work reports the result of mikrostructure analysis of samples after immersion. The bioactivity was influenced by the sintering temperature. It is evident, that the layer of the new hydroxyapatite phase formed during immersion on the surface of initial HAP samples changes with temperatures.
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Microstructure and Mechanical Properties of Steels
Stavinoha, Jakub ; Pavloušková, Zina (referee) ; Molliková, Eva (advisor)
This bachelor’s thesis is concerned with studies of relationships between grain size and mechanical properties of steels. Theoretical part deals with structure of the steels, with reaction of the material to the external stress, methods of estimating the grains size and strain-stress diagrams. In the practical part there are evaluated scratch patterns and strain-stress diagrams of steel C10E4Cu3+N. The conclusion of thesis includes the evaluations of the results from practical part and comparison with the theoretical part.
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The Structure and Properties of Cast Ceramic EUCOR
Klimentová, Jiřina ; Trunec, Martin (referee) ; Pavloušková, Zina (advisor)
The diploma thesis deals with cast ceramics EUCOR which can be described as three-phase system, composed of corundum, baddelyite and a glassy phase. The study was focused on the analysis of structure and phase composition of the material, together with the assessment of their influence on the basic mechanical characteristics. The techniques of light and scanning electron microscopy were used together with energy-dispersive microanalysis, X-ray diffraction and microhardness measurement.
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Comparison of microstructure of standard and modified fly ash autoclaved aerated concrete
Fleischhacker, Ján ; Kulísek, Karel (referee) ; Drochytka, Rostislav (advisor)
Nowadays, the amount of produced fly ash and fluidized ash is huge, so it is important to find ways of its proper use.Significant influence in field of fly ash consumption is production of autoclaved aerated concrete. Most important factor in production is properties of raw materials such as mineralogical and chemical composition. The study of raw materials is important to understand the mechanism of hydratation, tobermorite formation and mineralogy of final product. In present study, we investigate influence of raw materials to mineralogy of autoclaved aerated concrete, significantly to influence of fluidized ash on quality of autoclaved aerated concrete. Closure of study is design of the methodology, specialized in field of bachelor’s thesis study.
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Artificial stone - methods of preparation and properties
Pluskalová, Barbora ; Bayer, Patrik (referee) ; Rovnaník, Pavel (advisor)
The aim of the thesis „Artificial stone – Methods of preparation and it´s properties“ deals with the various methods and issues concerning the preparation of artificial stone. The thesis presents the summary of materials and various methods suitable for the preparation and points out mechanical properties, including durability of material, which serves as an alternative to natural stone. Further on, the thesis deals with the studies of binding systems based on geopolymers, which are used for the artificial stone preparation. This part of the thesis is associated with the experimental part, which is aimed at choosing the suitable mixing ratio of binder to aggregate in the artificial stone based on metakaolin geopolymer. According to the results of mechanical tests and aesthetic impression the author chose the best composition and then created a decorative element.
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Czech-Spanish and Spanish-Czech printed dictionaries
BRABCOVÁ, Eva
The theme of this Bachelor thesis is the description of the Czech-Spanish and Spanish-Czech printed dictionaries. The work is divided into two parts - theoretical and practical. In the theoretical part we dealt with the form and the content of bilingual dictionaries, with its macrostructure and microstructure. In the second part which is practical we analyzed selected Czech-Spanish and Spanish-Czech dictionaries and we compared its elements of structure. After the analysis of each dictionary we mentioned the evaluation of the dictionary. At the end of the work we summarized the evaluations. We mainly used the dictionaries containing commonly used vocabulary. Smaller part of the analyzed dictionaries is focused on economic vocabulary.
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