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Technology of Galvanic Anodization of Non-ferrous Materials and Its Alloys
Remešová, Michaela ; Hadraba,, Hynek (referee) ; Čelko, Ladislav (advisor)
The thesis is focused on the theoretical description of the technology of anodizing of aluminium, magnesium, zinc and their alloys. In this work, methods for formation of oxide layers and the used chemical processes are described in detail. The experimental part of this work deals with formation of oxide layers on aluminium, magnesium and zinc of high purity under different conditions. Oxide layers of different thicknesses were created on all three experimental materials. Aluminium was anodized in a bath of 10% H2SO4, magnesium in the bath of 1 mol/dm3 NaOH, and zinc in the bath of 0.5 mol/dm3 NaOH. Processes were carried out at laboratory temperature. On the aluminium, continuous oxide layer was formed. Furthermore rule "312" was verified, that can indicatively be used for calculating the thickness of the resulting oxide layer on the aluminium. When using lower current of 0.08 and 0.2 A for magnesium anodizing, dark colored layer was created comparing to higher current of 0.5 A. More rough appearance of the oxide layer was produced with increasing voltage. Further, it was observed for magnesium that the resulting layer comprises of two sublayers. For zinc, black colored layer was created when the voltage 20 V and current from 0.4 to 0.5 A were used. In the layer, two sublayers were also observed. For lower voltage and current (0.05 A, 0.17 V), formation of the oxide layer on the zinc does not occur, but the crystallographic etching was observed.
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Representation of selected elements in human hair
Jochimová, Eva ; Janoušková, Eva (referee) ; Zemanová, Jana (advisor)
Hair is an excellent matrix for monitoring trace elements and minerals in the body. To long-term changes in concentration of elements in the body are reflected in their value in her hair, so the assessment of the organism from the mineral analysis of hair is a very suitable method. This method is widely used in toxicological testing and forensics. This work deals with the analysis of Mg, K, Fe, Zn, Mn, Se, As, Cd and Pb in 100 samples by ICP-MS. It is a male hair samples with the age range 19 – 74 years. Analysis of hair revealed that concentrations of individual elements are moving in a narrow range of values. Values of older age category are in some case significantly deflective.
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The significance of magnesium for human health
Škeřík, Jan ; Hrstka, Miroslav (referee) ; Vránová, Dana (advisor)
Aim of this bachelor thesis was to compare different forms of magnesium. The characteristics and history of magnesium was briefly described at the beginning of the theoretical part. The following chapters explain the importance of magnesium in the body, hypomagnesemia, hypermagnesemia. Another section describes magnesium effect on various diseases, increased intake of magnesium and magnesium metabolism. The ninth and tenth chapter describes the effects of nicotine and alcohol on the metabolism of magnesium and magnesium content in drinking and mineral water. Conclusion of the theoretical part is dedicated to the description of the analytical methods of dosage forms. At the heart of the practical part was using several commonly used methods to determine best magnesium addition. It was the method of determination of the mass uniformity, determining magnesium contents in the tablet, the determination of disintegration, dissolution determination and hardness determination.
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Applications of magnesium alloys
Köhler, Tomáš ; Ročňáková, Ivana (referee) ; Němec, Karel (advisor)
This bachelor thesis includes basic knowledge of magnesium and its alloys. It also deals with their properties, division, and possibilities of heat treatment. The thesis then summarizes the application of magnesium alloys in individual branches of industries. With their usage for particular parts, a comparison with other construction materials, including the evaluation of using magnesium alloys and their advantages and disadvantages, is conducted.
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Microstructure and mechanical properties of biodegradable magnesium alloys
Faltejsek, Petr ; Ročňáková, Ivana (referee) ; Horynová, Miroslava (advisor)
The objective of this bachelor thesis is to create a summary of materials for biomedical applications, comparison of biodegradable and biocompatible materials and also summarization of biodegradable magnesium based alloys. The thesis has four parts. The first contains a description of each group of biomaterials. The second part is focused on magnesium and its alloys, including the evaluation of individual alloys with regard to biomedical applications. The third part contains information about the types of corrosion of magnesium and its alloys and various influences on the corrosion. The last part is focused on the influence of alloying elements on the human body.
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Application of magnesium alloys castings
Pernica, Vítězslav ; Liškutín, Petr (referee) ; Roučka, Jaromír (advisor)
Magnesium alloys are still idle in technical applications because of their properties. The history of metal is not very old, the first application of its alloy started on the beginning of the 20th century. Magnesium is very light. Its weight is about one third less than the weight of aluminum and it is the third most frequented structural metal. However its preparation and processing can be problematical because magnesium has high affinity to oxygen. It causes intensive burning. During the century of stature have been improved both production and alloys. The usage of magnesium alloys took more importance and it is the most used alloy in automotive field sofar. Recently its demand expands mainly in electrotechnics. Next usage we can find in aeronautics, energetics, military and many other branches.
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Disorders of mineral metabolism in cattle
KADLECOVÁ, Lenka
My Bachelor thesis is divided into the theoretical and practical part. The goal of the theoretical part is to elaborate the bibliography dealing with significant production diseases of cattle with emphasis on the disorders of the metabolism of mineral substances especially of calcium, phosphorus and magnesium. The bibliography contains a description of the symptoms, therapies and the prevention of particular diseases. The practical part of my Bachelor thesis includes two areas of findings. The first part focuses on the intake of the minerals substances in question contained in food and mineral supplements in dairy cows on the farm Horní Staňkov. The second part follows the contents of mineral substances and alkaline phosphatase in the blood plasma and urine of dairy cows. Based on the examination of blood plasma and urine an overview of the level of saturation with macroelements in dairy cows was made.
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Seasonal dynamics of selected blood parametres of selected flesh breeds of sheep bred in foothills conditions
ŽÁČKOVÁ, Klára
Sheep breeding is nowadays a developing branch of agriculture again. There is a lot of different breed and they react distinctly on the same conditions of the enviroment. Sheep of breeds charollais, suffolk, šumavská ovce and valaška bred in similar conditions were observed in spring and autumn of years 2007 and 2008. In these seasons were taking blood samples (from {$\pm$}7{--}24) ewes and lambs and were analyzed in hematology laboratory. There were determined haemoglobin level, haematocrit indicator, erytrocytes and leucocytes levels, glucose, cholesterol, triglycerides levels, urea and plasmatic proteins, activity of ALP and GMT enzymes, phosphor, calcium, magnesium, zinc and copper levels. The main objective of this project was determine seasonal changes in observed parametres. Next objectives were determine different changes in blood parametres in different breeds and different aimes of breeds. There were recognized that all the observed breeds don`t react the same way on similar conditions. There were not provably determined seasonal changes in observed parametres, but average Hb level was higher in autumn than in spring. Urea level was conversely higher in spring season than in autumn. The demostrable fact is, that the similar conditions induce different answers not only in different breeds but also in different aimes of breeds.
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