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Design of asphalt concrete mixture and determinantion of the resistance against permanent deformation
Němec, Jan ; Matoušek, David (referee) ; Varaus, Michal (advisor)
This bachelor thesis deals with the problem regarding asphalt concrete mixtures, concretely ACO 11+. This type of mixture has low resistance to permanent deformation (rutting) while high temperatures are present. The binder and aggregate tests regarding physical and mechanical properties were carried out. Subsequently the new mixture was designed on the basis of stricter requirement for grading envelope and air void content. The design mixture was tested for resistance to permanent deformation. From the obtained results the change in the national annex of the standard ČSN EN 13108-1 is considered in terms of change in testing temperature for some kinds of binders. The same tests were conducted in others asphalt laboratories in the Czech Republic to ensure the maximum comparability.
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Design and evaluation of asphalt rubber mixture
Hotař, Petr ; Dašek, Ondřej (referee) ; Kudrna, Jan (advisor)
The aim of bachelor thesis is to design the asphalt concrete for very thin layers using asphalt rubber and to perform laboratory tests according to ČSN EN 13108-2 and TP 148. The work is based on the literature review and respects properties of asphalt rubber. The expected properties of asphalt concretes for very thin layers are summarized and evaluated.
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Study of the influence of the dielectrics on the optoelectronic properties of electroluminescent devices
Foldynová, Klára ; Novák, Vítězslav (referee) ; Vala, Martin (advisor)
This diploma thesis is studing the possibilities of influencing the optoelectric properties of printed light emitting panels, which work on the principle of electroluminescence excited by alternating electric field. The aim of this worrk is to monitor the influence od dielectric properties of electroluminescent phosphor binder on the targeted electroluminescence. In the theoretical part of this thesis, there are described principles of electroluminescence, suitable materials methods of characterization and preparation of panels using printing techniques. Experiment part contains electrical characterization of selected binders to determine their dielectric constants. Subsequently, printing pastes were formulated in different weight ratios of binder electroluminescent phosphor and model light-emitting panels were prepared. Optoelectric characterization was used to determine the change in irradiance. It was found that the dielectric properties of the binder significantly affect the resulting irradinace. It has same irradiance for a smaller amount od phosphor than with the binder with a low dielectric constant. The finding of this work can be used to improve the luminosity at the electroluminescent panels.
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Material properties research for use in high-temperature solar thermal storage tank
Šot, František ; Vala, Jiří (referee) ; TROJAN,, Karel (referee) ; Steuer,, Radek (referee) ; Šťastník, Stanislav (advisor)
The use of thermal storage energy, using phase change materials appears to be an effective way to store thermal energy storage with the benefits of the high amount of energy while maintaining isothermal nature of the process. PCM methods are used in latent thermal storage systems for heat pumps, as well as in solar engineering or for temperature control in spacecraft. The past decade has extended these principles for cooling and heating in the building. There are a number of PCM systems, which operate over a wide temperature range, are used in various applications. This document includes a brief overview of the development and analysis of available thermal storage working mainly on the principle of PCM.
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Actual trends in manufacturing of ceramic shell moulds
Jankůj, Luděk ; Soukupová, Lucie (referee) ; Horáček, Milan (advisor)
Final thesis deals with the properties and production of ceramic shell moulds for investment casting method. Literature search focuses on the core of the production this mould used for ceramic and refractory slurry spreading. Attention is also paid to the technology of its production, testing ceramic shell mould and defects caused by improper manufacturing process forms. Another part of the work is focused on current trends in the production of ceramic shell moulds. The last part describes the production of ceramic shell mould in the company Česká zbrojovka. The conclusion summarizes information of production and the recommended choice of materials and manufacturing processes for ceramic shell moulds for the issue.
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Binders for supercapacitors electrodes
Gottwald, Tomáš ; Dvořák, Petr (referee) ; Sedlaříková, Marie (advisor)
This work deals with the issues of useing binders for supercapacitor electrodes and optimizing the technological process for their production. The work focuses on optimizing the amount of binder used in order to acheive the most capacity. The methodology consists of creating an appropriate experimental electrode and subsequent measuring its associated capacity with AutoLab. This aproach leads to creating grafs which show the dependencies of capacity on the amount of binder used.
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Phosphate bond of foam filters and its influence on the technical properties
Langer, Jan ; Lang, Karel (referee) ; Sokolář, Radomír (advisor)
The theses deals with the preparation of phosphate binder. This binder provides not only high strength, but also high-heat resistance. The bond is made of acid phosphate and alumina. There should be substitute of alumina (Cr2O3) or the adition of its. The slurry was prepared according to the applicable procedures of Pyrotek. After this, the slurry was applied to the polyurethane foam, dried and kilned. The result is foam filter for aluminium casting.
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Resistance to freezing and thawing of hydraulically bound mixtures to roads
Švantner, Lukáš ; Mondschein,, Petr (referee) ; Stehlík, Dušan (advisor)
The theoretical part of this master’s thesis contain comparing the methods of endurance hydraulic bound mixtures of concrete recycles against influence of water and freeze in Czech republic and some other states of The European Union. The practical part is dedicated about laboratory testing concrete recycles with mixtures of binders and its endurance against the water and freeze cycles in Czech republic. In made rollers is compared the strength in pure compression with the strength in pure compression after freezing cycles. From the results of the exams is considered about suitability of using these hydraulic bound mixtures to road construction depending on the kind of use binder, amount of the binder and water. Results of this thesis will be used to revision of national postscript of technological norm ČSN 73 6124-1.
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Utilization possibilities of industry gypsum and secondary materials containing for preparation of composites
Weiglová, Jana ; Šoukal, František (referee) ; Opravil, Tomáš (advisor)
The work studies the possibilities of the utilization of secondary raw materials produced by power industry. It addresses mainly the gypsum by-products and fluidized coal combustion ash. As for the secondary raw materials the content of sulphites is observed and the dependences of their transformation to sulphides via natural oxidation by air oxygen or by addition of adequate oxidant are studied. The work follows with describing the effect of sulphides contained in raw materials on the mechanical properties of composites prepared from several various matrices such as alumina or portland cement, lime or portland clinker. As for pure portland clinker the ability to retard the setting is also observed. The amount of contained sulphites is measured volumetrically via indirect titration of iodine surplus by sodium thiosulphate with the starch size as the indicator.
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Development of ceramic shell for manufacturing of large Al investment castings
Hýbal, Ondřej ; Šmatelka, Jakub (referee) ; Horáček, Milan (advisor)
This diploma thesis deals with the choice of the most suitable composition of a ceramic shell mold for aluminum castings made by investment casting technology. The most suitable composition of the ceramic shells is chosen based on the results of the tests and from economic point of view. This thesis also deals with evaluation of the current conditions of the production of ceramic shells in Alucast, s.r.o and recommendations for stabilizing the process of manufacturing ceramic shell molds.
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