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Vinyl prepolymers - methods of preparation and application
Černý, Miroslav ; Petrůj, Jaroslav (referee) ; Kučera, František (advisor)
The theoretical part of this thesis is focused on bulk radical polymerization of styrene, methylmethacrylate, vinyltoluene and paramethylstyrene. It summarizes actual informations about kinetics and performance possibilities of bulk polymerization. Experimental part deals with polystyrene prepolymers preparation by bulk polymerization. The aim is to find optimal conditions for prepolymers preparation. Prepolymers should be usable for subsequent polymerization nearly up to 100% conversion. Conversion values were gravimetrically determined and molecular weights were obtained by viskosity measurements, which were realized by Ubbelohde viscometer. In the experimental part, there were performed simulations targeted on conversion dependence on time. The purpose was a prediction of monomer conversion at a given time during polymerization. Differences between reality and simulation were low in most of cases and the found form of kinetic behavior calculations provides satisfying results. In the conclusion of this thesis was suggested a new procedure for polystyrene prepolymers preparation.
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First-principles study of stability of solid crystals
Pleskot, Ondřej ; Šesták, Petr (referee) ; Černý, Miroslav (advisor)
This work deals with a modeling of an electronic structure of solid crystals. Specifically, densities of valence electrons, and the density of states are calculated using first-principles code VASP for three crystals representing three different types of bonding. These are the metal bonding in a crystal of aluminum, the covalent bonding in a diamond crystal, and an ionic bonding in the crystal of rock salt. From calculated values of stress and crystal energy are then determined some macroscopic parameters of crystals, such as the equilibrium lattice parameter, the bulk modulus and the theoretical strength under isotropic tension.
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Solution of modernization technology of part air-pump
Černý, Michal ; Dvořák, Jaromír (referee) ; Kalivoda, Milan (advisor)
The subject of this thesis is modernization of manufacturing process of air-pump component in a specific company. The work is focused on designing a new variant of the manufacturing process for mass production of the given component. The introduction evaluates the technology of product manufacture and describes the existing technologies of performed prototype production. The second chapter introduces a machine-tool, which will play the existing role of production, which will streamline the productivity of work, reduce the risk of human error and improve the quality of manufacturing accuracy. Further new tools are selected and a new production technology is designed. In conclusion, machine times and an overall design of production are evaluated.
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Design of hydraulic travel of reaper`s drive unit
Galda, Martin ; Černý, Michal (referee) ; Brandejs, Jan (advisor)
The goal of my bachelor work is Design of hydraulic travel of reaper`s drive unit on exploration of facts with these parameters: independent wheel drive, fluent speed regulation in both forward and reverse motion, speed 0-10 km/h. Briggs&Stratton I/C OHV AVS engine is used for working the machine. It's output is 8,46 kW. Dakr, s.r.o, company demanded, that approximately 20% of engines output is to be used for driving.
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Design of electrical travel of reaper`s drive unit
Otoupalík, Jan ; Černý, Michal (referee) ; Koutný, Daniel (advisor)
This bachelor thesis focuses on the design of electrical travel for universal mowing machine, which will be controlled remotely. Designed travel has independent wheel drive, the maximum speed of 10 km per hour and can be used in the terrain with a slope of 30°. The thesis deals with the determination the parameters of the travel, design of the possible electrical drive units and design with respect to the stability of the device. Another part of the thesis deals with the design of the travel and describes particular parts of the travel.
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Mechanical pretanning in sewage works
Černý, Marian ; Grosman, Martin (referee) ; Němec, Zdeněk (advisor)
The bachelor thesis contains a literature search dealing with mechanical equipment of waste water treatment plants. After introduction of waste treatment there is stated some description of technical and construction search of particular equipment, system of their operating, analysis of their operation parameters and their using on waste water treatment plants in this bachelor thesis. There are described typical ordering of particular equipment in to technological lines on waste water treatment plants. The bachelor thesis contains description of self-cleaning screen, hand skimmed screen, mechanical coarse screen, mechanical fine screen, equipment for grit and sand removing, skimmed cylinder strainers, screw conveyors, screw presses for screenings with washing and integrated coarse pre-treatment. There are published some schemes, sketches, photos and tables of technical parameters above mentioned equipment in this bachelor thesis. The sketches of technical drawing character are treated in Autodesk ACAD 2005 program.
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Utilization of light emitting diode lighting
Podola, David ; Černý, Michal (referee) ; Paloušek, David (advisor)
This bachelor thesis deals with problems of illumination by LED diodes. Basic concepts of lighting technology are defined in the first part. The second part is dealing with the construction of body LED diodes and explains the principle of white light formation to LED. Introduces problems of cooling. Gives an overview of the available power sources for LEDs. Provides an overview of how to control lighting by using motion sensors and presence sensors. Will be made basic economic balance sheet, which will evaluate the advantages of using LED sources. Attachments provide the LED catalogs of manufacturers, accessories for LED and comment on other sources of information.
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