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Options of preparation of tobermorite
Dlabajová, Lucie ; Másilko, Jiří (referee) ; Opravil, Tomáš (advisor)
The bachelor thesis deals with options of preparation of tobermorite. Tobermorite is a mineral, which, thanks to its composition and properties, is an important phase in aerated concrete. On the field of science and research, an attention has been drawn on tobermorite as an ion ex-changer. Synthesis of a pure mineral can cause problems with testing and improving its properties. Tobermorite crystallizes together with other calcium silicate hydrates from system CaO-SiO2-H2O during a hydrothermal reaction. This thesis mainly focuses on influence of choosing starting materials and their treatment before the hydrothermal synthesis. Other influences which are studied are conditions of hydrothermal processes and their influence on final products of hydrothermal synthesis. Phase composition of prepared samples was characterized by XRD and TG-DTA. As an additional analyze was used scanning electron microscopy (SEM).
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Application of a reusable vacuum membrane for production of fiber reinforced plastics
Talavášek, Václav ; Zouhar, Jan (referee) ; Gregor, Lukáš (advisor)
The thesis focuses on the manufacturing process of the composites with fiber reinforcement and polymer matrix. The theoretical part contains a description of conventional manufacturing processes. The experimental part of the thesis was based on the design modification of an old convention mold. The aim was to make design changes for the usage of a vacuum membrane. On the mold were made several tests. The goal was to find out the design faults of the mold. The next chapter focuses on the economic comparison of the conventional process and the reusable vacuum membrane process. The last chapter focuses on the design of a new mold, which is going to be utilized for mass production.
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Technology of manufacturing of carbon fibre composites by hot forming
Přikryl, Pavel ; Slaný, Martin (referee) ; Zouhar, Jan (advisor)
This master’s thesis deals with the composite materials and especially aims on the carbon and glass fiber composites. It points out different composition types and manufacturing methods which reflect in the different mechanical properties, final quality of the manufactured part and also in the manufacturing time. The practical part includes two particular manufacturing methods using prepregs, one cured in an autoclave and one by hot compression moulding.
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The technology of aerated concrete
Koutný, Ondřej ; Repka, Martin (referee) ; Opravil, Tomáš (advisor)
Civil engineering is integral part of industry in each developed country. Naturally the construction point does not play the main role here, but also the material of building segments. In last fifty years the new possibility has been discovered against classic brick in form of autoclaved aerated concrete. This material gathers its customers not only due to low weight and easy application with sufficient strength, but particularly due to excellent heat-insulation properties. Contemporary trend in research of aerated concrete points to application of alternative raws, as for example metakaoline, to improve final properties of product by preserving of current technology and price.
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Study of usabiliti of sands for preparation of aeroconcrete in hydrotermal condition
Straka, Radek ; Ptáček, Petr (referee) ; Opravil, Tomáš (advisor)
A building industry is expanding branch all the time and it intervenes in the life of everyone. Aeroconcrete is very attractive and actual subject nowadays because economy is important point of view of production. This material finds a wide-spread use thanks to its specific properties. The good manipulation and great thermal insulating properties are secured by its porous structure. Furthermore, proper material selection provides a saving of power of house for every customer demands. Due to aeroconcrete's sufficient compressive strength it is useful for both constructions and internal walls. Fundamental and very important for final material properties is raw material composition of aeroconcrete. A relationship between composition of filler (quartz sand) and resultant properties of aeroconcrete is an objective of the thesis.
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The optimization the production of selected medicinal substances
Fránek, Jan ; Ing.Oldrřich Smékal (referee) ; Omelková, Jiřina (advisor)
Mgr. Jan Fránek 2011: The optimization the production of selected medicinal substances The diploma thesis dealt with optimization of production of fingolimod by hydrogenation. During the optimization of production, there was reduction of benzylic hydroxygroup and nitrogroup of nitrofingotriol. Reduction of two different groups caused dividing process of hydrogenation into two phases. The original intention was to optimize production only in the autoclave, but the need of using acidic catalytical medium in first phase led to dividing the production into reduction in the reactor and following catalyzed hydrogenation, already in neutral conditions, in the autoclave. The way of preparation of active substance by using an autoclave had not been explored in detail before. Evaluation of optimization is a part of results. There are also production charges on pilot plant included in results. Because the results of procedure of the pilot unit were not uniform, it was necessary to continue in optimization even after finishing the production in pilot plant. Following procedure modified according to the latest experiments was passed to the operating process.
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Application of microwave heating for curing of adhesives and composite materials
Wagnerová, Klára ; Urík, Tomáš (referee) ; Klement, Josef (advisor)
This bachelor's thesis concerns the microwave technology and the possibilities for its use in the curing of adhesives and composite materials. The thesis is divided into two main parts. The first part summaries theoretical findings about microwave technology. There is the principle of microwave heating described as well as constructions of microwave devices. Also the possibilities of using this technology for the curing of composite structures are mentioned. The second part of the thesis is devoted to the practical verification of the theoretical assumptions.
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Design of autoclave
Poduška, Libor ; Létal, Tomáš (referee) ; Nekvasil, Richard (advisor)
Master thesis deals with general basic design od autoclaves. It deals with the design of an optimal design solution autoclave to set parameters with the design requirement of hermetic doors for loading the workpiece. This solution is analyzed regard to stable pressure vessels. The whole design is processed in parametric SolidWorks software with which they are executed and initial stress analysis of individual designs. Final strength FEM analysis is performed using Ansys. Some proposals are technical-economic evaluation.
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The technology of aerated concrete
Zezulová, Anežka ; Kalina, Lukáš (referee) ; Opravil, Tomáš (advisor)
The technology of aerated concrete is a topic that is permanently studied and developed because of the incessant demand for a building material which ensures relatively high strength at low volume weight. This bachelor’s thesis examines the influence of replacing a part of sand with another silica material – microsilica. The increase of mechanical strength is expected at the same volume weight. Microsilica contents around 98 % of amorphous silicon dioxide with a high specific surface area that is substantially higher than a specific surface area of a ground sand. The reactivity of silicon dioxide increases with a higher specific surface area and also with the creation of a mineral tobermorite, which is the keeper of the strength in autoclaved aerated concrete. Three types of microsilica were chosen to examine the influence of replacing a part of sand with microsilica according to their availability for manufacture: microsilica Sikron and Elkem 971 U, microsilica Grace Davison was tested only marginally. Tests were carried out to determine volume weight, compressive strength, phase composition (by X-Ray diffraction method), and the content of tobermorit (by TG-DTA method).
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