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Structural and Chemical Aspects of Calcium Phosphate Formation in Tooth Enamel
Kallistová, Anna ; Skála, Roman (advisor) ; Frýda, Jiří (referee) ; Oldak, Janet (referee)
Tooth enamel is the hardest and most resistant highly mineralized inorganic component in mammalian bodies that significantly affects both the life quality and expectancy of an indi- vidual. Its specific qualitative properties are given by the biomineralization process responsible for its formation. In this process the mineralization of hydroxyapatite (HAp), the only inor- ganic phase composing the mammalian hard tissues, is controlled by activity of enamel-forming cells ameloblasts and their products. Over the past years, the studies of enamel matrix pro- teins, their structure, composition and function has become the prevalent field of experimental investigation. However, unique enamel qualities, which enable the teeth to withstand high pressure and stress demands, cannot be accurately assessed without the thorough systematical study of its mineral compound. In this thesis, I focus on the crystallographic and compositional characteristics of enamel hydroxyapatite and their influence on the mechanical properties of teeth. Obtained results are discussed in context of developmental and adaptation dynamics of mammalian species. The main aspect of the work is to extend our knowledge about the protein-mediated mineraliza- tion process from the perspective of inorganic compound and its contribution to the...
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Thermobarometry of ultramafic rocks in ophiolites of the Vardar Zone in FYR Macedonia
Fikar, Lukáš ; Skála, Roman (advisor) ; Kallistová, Anna (referee)
This thesis is divided into review section followed by an experimental part. The first part focuses on geothermobarometry, illustrates its history and provides its detailed principles. Furthermore, it discusses various possibilities of the use of different mineral assemblages for purposes of thermometry and barometry. This part puts an emphasis on exchange reactions, the role of solvus in themometry, reactions based on weight transfers, and reactions involving gas phases. A chapter on Macedonian geography and regional geology provides a detailed description of the Vardar ophiolite belt, which was the source of the samples used in experimental part of the thesis, and its relationship toand other geological units in Macedonia, namely the Eastern Vardar Ophiolite zones, the Kopaonik unit, and the western part of the Vardar Ophiolite zone. Finally, a process of exsolution in subsolidus, which is impostant for the group of pyroxenes, is discussed. The area of interest is the use of the process of exsolution in thermometry. The thermodynamic conditions for exsolution are important features of the exsolution. The experimental part of the thesis includes a description of the samples and results of chemical analyses carried out with an electron probe microanalyzer. Chemical data were processed with two...
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Crystal chemistry of pyroxenes and amphiboles from the České středohoří
Kallistová, Anna ; Skála, Roman (advisor) ; Ulrych, Jaromír (referee)
Contents of major, minor and trace elements in clinopyroxenes and clinoamphiboles of basanites, volcanoclastics, essexites, sodalitic syenites, and monzodiorites of the České středohoří Mts. has been determined using an electrone microprobe and LA-ICP-MS techniques. Composition of clinopyroxenes corresponds to either diopside or augite and clinoamphiboles can be classified as kaersutite or pargasite. Some pyroxenes display pronounced sector zoning showing increased contents of Mg and Si in pyramidal sectors whereas prismatic sectors show Fe, Ti and Al enrichment. Chemical composition of both sectors corresponds to diopside. Growth zoning has been found in the samples from basanites and volcanoclastics. Grain cores display the chemistry of augite and towards the rim the chemical composition changes to diopside. Samples have also been analyzed by powder and single crystal X-ray diffraction techniques. Samples of pyroxenes appear to be either pure or they contain negligible admixtures of phlogopite. Samples of amphiboles are also either without any admixtures or they show contamination by low amounts of diopside or augite, or phlogopite may rarely be encountered. Mutual relationship between the size of the unit cell parameters b and and substitutions in M1,2,3 and A sites has been observed. Longer mean T-O...
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