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Increasing the life of cutting blades
Rohlínková, Marie ; Lidmila, Zdeněk (referee) ; Podaný, Kamil (advisor)
Thesis suggest possible methods of increasing the life of a cutting blade, which is made of steel 19 733 and is used for cutting stator laminations from silicon materials. Mentioned metal sheets are very hard which leads to higher demands on cutting blades. The optimal method chosen, as based on studies of relevant literature, was ion nitriding which provides increase in surface hardness to 64 HRC. Increase in surface hardness while also preserving the toughness of the core was further confirmed by an experimental measurement of hardness, which was measured on two samples. First sample was left in the original state and the second sample was ion nitrided. According to the scratch pattern the thickness of nitrided layer is 0.1 mm.
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On the modern surface treatment of pressure casting dies
Černý, Štěpán ; Sliwková, Petra (referee) ; Píška, Miroslav (advisor)
Bachelor thesis is focused on the influence of surface treatments due to prolonging life and decreasing an amount of service hours on the die casting molds of aluminium alloys. Theoretical analysis of the problem deals with the requirements for tools materials used for making these moulds. Furthermore it deals with the materials which are most commonly used in their production and the species of aluminium alloys which are most commonly casted. The second part of this thesis, which is discussed in detail, deals with design solution regarding to usage of surface finishes on the moulds for die casting and their specific properties. Another part of this thesis contains experimental tests where was measured selected coating in order to determine its behaviour during the casting cycles with a focus on increasing lifetime of the mould insert, also reducing the amount of glued metal on the walls and finally improving the surface of casted part. It was found, according the analysis results, that the TiAlN coating helped to reduce the amount of glued metal on the mould walls. This also helped to reduce the amount of service intervals. On the other side for achieving much better results is better to use TiB2 coating. It has been experimentally confirmed that the TiAlN coating is not suitable for using in die casting moulds of aluminium alloys.
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Influence of range of reconstruction on the price of building construction
Hasilík, Jakub ; Kaláb, Petr (referee) ; Aigel, Petr (advisor)
This diploma thesis deals with the influence of range of reconstruction on the price of building construction. Effect of the extent of reconstruction consists in comparing of the total costs of the bridge during reconstruction of the top of the bridge leaving the main structure and during the reconstruction realized with the exchange of the main supporting structure. The total costs incurred are expected for 60 years.
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Methods of environmentally friendly carcass disposal
Blažek, Pavel ; Kropáč, Jiří (referee) ; Novotný, Pavel (advisor)
In the thesis we deal with a summary of all available methods of disposal of environmentally friendly vehicles that are currently available. Addressing this problem is to find appropriate procedure, thereby simplifying and reducing the cost of processing vehicles. We also deal with this issue in terms of legislative, therefore a summary of the law on dealing with waste vehicles. The aim of this work is to introduce the methods of processing whole vehicles as well as various parts of cars and find the most appropriate methods of disposal
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Influence of detergents on the accelarated lifetime tests of PE pipes grades.
Štolfová, Kristýna ; Přikryl, Zdeněk (referee) ; Nezbedová, Eva (advisor)
This thesis studies the lifetime of the PE pipes materials. For determination of the lifetime one of the standard accelerated tests (Full Notch Creep test) was used. The main goal is to assess the influence of different types of detergents on lifetime. Specimen preparation and measurement procedure corresponding to the relevant ISO standard (ISO 16770: Plastics - Determination of environmental stress cracking (ESC) of Polyethylene (PE) - Full Notch Creep Test (FNCT)). Air, distilled water, Arkopal N 090 and Arkopal N 110 were used as detergents.
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Stress and strength analysis of steam turbine valve
Kořínek, Tomáš ; Vosynek, Petr (referee) ; Petruška, Jindřich (advisor)
This diploma thesis deals with the determination of lifetime and computational modeling of stress strain states arising in the body of the steam turbine valve. Due to the high temperature of the inlet steam, the creep of the material which fundamentally affects its final lifetime is also considered in the calculation. The lifetime is evaluated by four different procedures using the finite element method via the ANSYS software. The results are compared at the end of this work. One of the chapters is focused on solving the problem of the creep in the ANSYS software environment.
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Návrh silového členu simulátoru zátěže pro dlouhodobé zkoušky VTG aktuátoru
VANĚK, Daniel
The topic of diploma thesis is focused on the design of the life of the power member of the preparation with springs (the load simulator). The preparation is used for long-term testing of VTG (Variable Turbinen Geometrie) actuators. The diploma thesis follows the author's bachelor's thesis (Vaněk, 2019). The theoretical part is focused on the fatigue of the material, the geometry of the used springs, the decomposition of the test profile using the Rain flow method and the Matlab (interactive software). The practical part of that thesis deals with the analysis of the test profile, the calculation of the accumulation of damage and the statistical evaluation of the service life of the used springs.
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Brand quality ŽIVOTNOST PLUS
BRABCOVÁ, Kristýna
The work analyses the attitude of the holders and representatives of the general pu- blic to this brand. It also deals with the overall problems of product life. The research is based on a questionnaire survey method. In conclusion, the strengths and weaknesses of the brand of the Quality Vitality plus are summarized and the basic recommendations are outlined.
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The effect of oxygen on the triplet state lifetime of carotenoids in photosynthetic complexes
Vahalová, Petra ; Pšenčík, Jakub (advisor) ; Bína, David (referee)
The aim of this study was to find a suitable method of preparation of anaerobic conditions in or- der to determine intrinsic lifetimes of carotenoid triplet states in photosynthetic light-harvesting complexes. We have compared the following three methods: (1) blowing an inert gas (nitrogen) above the surface of a liquid sample, (2) removing oxygen by means of chemical reactions catalyzed by glucose oxidase and catalase and (3) use of sodium dithionite. Each method was first tested on meso-tetra (4-sulfonatophenyl) porphine and then applied on the main light-harvesting complex of Amphidinium carterae. The lifetimes of the triplet states of carotenoids in the light-harvesting complex were determined from kinetics measured directly by a photomultiplier tube and from transient absorption spectra measured at different delays after the excitation pulse by an intensi- fied CCD camera. The effects of the used substances on the sample stability were evaluated by measuring steady-state absorption spectra and pH. Blowing the sample with nitrogen was time- consuming and less efficient in attaining anaerobic conditions compared to the other two methods. In contrast, anaerobic conditions were obtained in a relatively short time after the application of so- dium dithionite; however, it caused acidification of the sample ralated...
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