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The Study of ZnO Crystal Growth in Supersaturated Alkaline Solution
Bannert, Tomáš ; Máca, Josef (referee) ; Chladil, Ladislav (advisor)
This thesis deals with the study of growth of zinc oxide crystals from supersaturated solutions using a scanning electron microscope and XRD methods. The work is divided into a theoretical and an experimental part. The theoretical part analyses issues related to the principle of operation of electrochemical cells with an emphasis on Ni-Zn batteries and phenomena limiting the life and efficiency of Ni-Zn batteries with a focus on phenomena that affect precipitation processes of zinc oxide crystals. It also analyses and compares the appropriateness of the methods that have been used to study the growth of the prepared zinc oxide crystals. The experimental part describes the preparation of a supersaturated solution, the process of each analysis and its evaluation. The results of each method are compared with the theoretical assumptions and among themselves. The experimental part also contains a chapter dealing with the design of in situ X-ray diffraction analysis methods of the obtained zinc oxide crystals.
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Preparation and properties of porous zinc material
Ryšťák, Jaroslav ; Fintová, Stanislava (referee) ; Doležal, Pavel (advisor)
Bachelor thesis is focused on preparation of bulk material prepared from zinc powder by cold pressing followed by sintering. Topic of the work includes characterization of prepared material depending on the choice of the compaction process conditions. Bulk material is characterized by physical-mechanical tests, structure and porosity. Thesis solving and focuses on study and control of processes during bulk material preparation and description of the processes from physically-chemical point of view of the structure creation and final material properties.
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Powder metalurgically prepared materials based on Zn and Ca
Morcinek, Tomáš ; Hasoňová, Michaela (referee) ; Doležal, Pavel (advisor)
The topic of this bachelor thesis is a process of preparation and characterization of bulk material from zinc and calcium powder mixture by hot pressing. Materials thus prepared were evaluated in terms of their microstructure and physical-mechanical properties. The influence of calcium content in the material on physical-mechanical properties of the resulting structure was observed. The solution is focused on exploration of the influence of material composition in the process of preparation of bulk material, and description of these processes from the physical-chemical point of view on the structure formation and the resulting properties of the material.
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Preparation processes and properties of porous zinc material
Moleková, Kristína ; Březina, Matěj (referee) ; Hasoňová, Michaela (advisor)
Bachelor thesis occupy with preparation of porous material from zinc powder by cold pressing, cold pressing followed by sintering and hot pressing. This thesis contain both preparation of bulk material, and charakterization of materials based on the compaction process conditions. Impact of pressing process on subsequent progress of sintering and final attributes of materials is evaluated. Bulk material is characterized considering to structure, porosity, and physical-mechanical properties. Properties of final metarial will serve to optimize conditions for process of pressing and sintering.
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Use of pollution indices for evaluation of soil contamination
Čmelíková, Dorota ; Pavlovský, Jiří (referee) ; Doležalová Weissmannová, Helena (advisor)
This thesis focuses on heavy metal contamination of soil and the use of pollution indices for its evaluation. Two regions were selected for assessment and comparison. The chosen heavy metals were mercury, zinc, copper, lead and cadmium. These heavy metals were analysed in 15 samples from Kyjov nad 15 samples from Ostrava. Methods of analysis were AMA-254 and FAAS. The established concentrations were used to calculate pollution indices and for health risk assessment. Pollution in Kyjov was assessed as low to medium without any health risks. Ostrava region was assessed as moderately to highly polluted with a low health risk, especially for children.
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Study of the effect of myocardial fibrosis on elemental distribution in rat soft tissues using Laser Ablation ICP-MS
Machalová, Martina ; Zlámalová Gargošová, Helena (referee) ; Vašinová Galiová, Michaela (advisor)
The most common cause of death in the Czech Republic continue to be cardiovascular diseases. The field of heart failure therapy still keeps moving forward. Yet myocardial fibrosis is one of the consequences and causes of heart failure for which there exists no effective medical care. The solution would be predicting the advancement of fibrosis and a preventive therapy. Many medical methods are being developed now in this regard, and the element distribution in affected tissue could help them. That is the reason why this work centers on the research of the element distribution in rat hearts with an induced myocardial fibrosis. An influence of sample couloration on the analysis was observed during its course. Special attention was paid to the distribution of iron in the fibrotic tissue as well as to the comparisson of the images of myocardial fibrosis. It seems that the iron distribution specificly could be helpful in recognising a damaged myocardium.
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Influence of Zinc in Byproducts on Hydration and Properties of Blended Portlands Cements
Šilerová, Iva ; Palou, Martin (referee) ; Rovnaníková, Pavla (referee) ; Havlica, Jaromír (advisor)
The theme of this work is to monitor the effect of zinc on the properties of blended Portland cements. Zinc was tested in the form of two-soluble salts: Zn(NO3)22 H2O and ZnCl2 and a very slightly soluble compound ZnO. Blended cements were prepared by partial replacement with finely ground granulated blast furnace slag, high-temperature and fluidized bed combustion filter fly ash. Flow properties were studied on the prepared pastes. Impact on hydration reactions was examined by using of isothermal and isoperibolic calorimetry. Flexural and compressive strength were measured as mechanical properties of the prepared test specimens. The phase composition of the prepared composites and incorporation of zinc ions in the cement matrix via leaching tests and FTIR analyzes were also studied. Microstructure development of cement samples was tested by SEM analysis with EDS. Influence on ecotoxicity was also measured.
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Structure and mechanical properties of magnesium materials prepared by SPS
Pleskalová, Kateřina ; Hutařová, Simona (referee) ; Doležal, Pavel (advisor)
This diploma thesis deals with the processing of the magnesium-based powder materials with the addition of zinc by the spark plasma sintering. The aim of this thesis is to evaluate influence of sintering parameters and zinc content on the microstructure and mechanical properties of the material. First part of the thesis is literary research which is divided into two main chapters. The first chapter describes magnesium-based materials and mentions their use as biomaterials. The second chapter discusses powder metallurgy, specifically magnesium powders and spark plasma sintering. In the experimental part the powders were sintered at temperatures 300 °C and 400 °C and an analysis was performed using optical microscope, scanning electron microscope, then also EDS analysis and hardness, microhardness and three-point bending tests were performed. An increase in hardness was observed with increasing zinc content and with increasing sintering temperature. The flexural strength was higher for materials sintered at a temperature of 400 ° C.
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