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Coating properties of cutting tools carbide
Doležalová, Petra ; Bumbálek, Bohumil (referee) ; Osička, Karel (advisor)
Diploma thesis is divided into two parts. The first part is focused on theoretical description of coating methods, on currently used coatings, their properties and it is also focused on description of methods, which are used for analyzing each property. The second part focuses on testing of coatings and analyzing of the values obtained from experiments. The aim of this thesis is then to compare the properties of the tested coatings.
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Reoxidation in steel
Kotásek, Petr ; Veselý, Pavel (referee) ; Šenberger, Jaroslav (advisor)
This work is about development and methodology verification of data collection which will be used in the research of the reoxidation in steel castings. To examine reoxidation rate will be measured oxygen activity in the furnace, in the ladle and in the mould. Next it will be evaluated the chemical structure of mould slag, the chemical changes of steel and measured the volume and the area of the casting defects. Each technique is briefly described by the principle of measurement and each method has the results which are analysed. In the conclusion the experiment is summarized and there are mentioned the observations from this experiment.
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Elimination of degradation processes of metallic thin films
Danovič, Jakub ; Šubarda, Jiří (referee) ; Šimonová, Lucie (advisor)
This work deals with issues of thin films, their behaviour in different enviroments and protection of theese films against unwanted degradation processes. Metal thin films are made by special physical or chemical methods in the presence of vacuum. Deposition is performed on properly cleaned substrate made of different materials, for example glass, ceramics or another metal. Theese films degrades under the influence of moisture, heat and other. There are several types of films on different bases made to prevent thin films against degradation.
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Influence of Inert Atmosphere on Surface Wetting in Lead Free Soldering
Nestrojil, Michal ; Špinka, Jiří (referee) ; Starý, Jiří (advisor)
This master´s thesis dealing with study of influence of inert atmosphere on the wettability of soldered surfaces. The theoretical part is discussed the issue of the soldering, solder joint, oxidation, and inert atmosphere. The glass cover with internal inert gas preheating for the wetting balance testing was prepared in the practical part. With this adjustment were realised tests, in which was examined the effect of the inert gases on the wettability of different materials combination. Further experiments were focused on plasma surface cleaning as possible flux substitution. The evaluation of these experiments were discussed in the end of this master´s thesis. Some of topics were designed for further experiments.
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Kinetics of benzo[a]pyrene destruction and identification of its products
Ryšavý, Jan ; Kolek, Emil (referee) ; Šimko, Peter (advisor)
This diploma thesis is focused on the study of conditions of benzo[a]pyrene, one of the major contaminant of foods, photodegradation under different conditions (solvents with different polarity, light sources, presence of antioxidants). In another part of the thesis, the degradation process of benzo[a]pyrene at various concentrations was studied, in order to characterise the kinetic aspects of photoinduced degradation. The attempt to identify the products of benzo[a]pyrene photodegradation was performed involving methods of gas chromatography and high performance liquid chromatography coupled with mass detectors, as well.
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Study of AlSi protective coating after degradation
Vítková, Gabriela ; Řičánková, Veronika (referee) ; Hutařová, Simona (advisor)
Materials used for high temperature applications works in a very aggressive environment (oxidation, hot corrosion, erosion, fatigue, creep). Demands on these materials are very high. Nickel-based superalloys show the certain stability in this environment. Improved resistance to oxidation and hot corrosion can be achieved by using protective layers such as diffusion barriers. This thesis is focused on changes of microstructure and properties of AlSi layer applied by „slurry“ method on nickel-based superalloy Inconel 713 LC, due to long-term thermal exposition at 800, 900 a 1000 °C.
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The problems of fenol sorption from waste water
Židek, Michal ; Pavlovský,, Jiří (referee) ; Doležalová Weissmannová, Helena (advisor)
The bachelor work deals of sorption of phenol from waste water. In theoretical part the basic characteristic of phenol, their effects and presence in environmental compounds are described. The possibility of removal phenol from waste water in waste water treatment is also described. The adsorption process of removal phenol introduced too. The analysis current adsorbents using in removal phenol from aqueous solutions and characteristic properties are also presented in relation to materials on the base of clay minerals. The experimental part is focused on the possibility of removal phenol from aqueous solution via adsorption mechanism under various pH conditions.
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Testing of polymeric materials under climatic conditions of Antarctica
Mičkal, Petr ; Sluková, Michaela (referee) ; Krmíček, Lukáš (advisor)
The bachelor's thesis generally deals with polymer materials and evaluates the possibility of testing their resistance to extreme climates of Antarctica. Described herein are various polymer materials, their characteristics, structure, properties and more thorough and detailed descriptions of selected polymers. The next section describes the basic types of degradation these polymers are exposed to, when facing the extreme conditions of the Antarctic climate. The practical part contains evaluations of tests made on the degraded polymer materials that were collected in Antarctica during the southern Antarctic season of 2013-2014 by Ing. Bc. Pavel Kapler, Ph.D, who is a superintendent at the Czech scientific station JG Mendel.
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Comparison of Dry and Wet Oxidation Process during Low Pressure Boron Diffusion with BBR3 in Solar Cell Production
Mojrová, B.
This paper deals with replacing a dry oxidation with a wet oxidation process during low pressure diffusion using boron tribromide (BBr3) in solar cell production. Because the liquid boron trioxide (B2O3), a product of a chemical reaction during diffusion, condenses apart from wafers on walls of quartz tube, it is essential to clean the tube after diffusion. This could be done by evaporation of water into the tube after unload or, in order to make the production time shorter, by replacing the dry oxidation with wet oxidation process. In this paper a comparison of the wet and dry oxidation is given with regard to the solar cell production.
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Electrochemistry of Flavonolignans and their Interactions with DNA and Proteins
Pyszková, M. ; Zatloukalová, M. ; Biedermann, David ; Křen, Vladimír ; Ulrichová, J. ; Ramešová, Šárka ; Sokolová, Romana ; Vacek, J.
Electrochemical oxidation of flavonolignans silybin, silydianin, silychristin and their 2,3-dehydroderivatives, was studied using ex situ and in situ cyclic and square wave voltammetry at pyrolytic graphite electrode. The pilot results presented here could be used for further investigation of mechanism of oxidation and reactivity of flavonolignans to DNA and proteins.
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