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Production and use of zinc alloy castings
Odehnal, Pavel ; Müller, Peter (referee) ; Pernica, Vítězslav (advisor)
The bachelor thesis focuses on the development of a literature search dealing with zinc production and its applications. The theoretical part is focused on the methods of production of pure zinc, the alloys used and the methods of processing of these alloys. Furthermore, selected branches of application of castings in industry are described. The work is supplemented by an experiment concerning the evaluation and remedy of defects occurring on the component.
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Production of castings from aluminum alloy Unifont 90
Chvátal, Pavel ; Lána, Ivo (referee) ; Kaňa, Václav (advisor)
The diploma project deals with the aluminum foundry alloy Unifont-90. The aim of the project was to observe the effect of different pouring temperature and wall thickness of the casting on the mechanical properties and microstructure of the material. The theoretical part of the project describes selected properties of aluminum foundry alloys and foundry processes used in their casting. In the experimental part, measurements of mechanical properties and microstructure of the material of the investigated Unifont-90 alloy took place.
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Bioavailability of magnesium and zinc from food supplements
Lindovský, Patrik ; Křikala, Jakub (referee) ; Diviš, Pavel (advisor)
This bachelor's thesis deals with the analysis of dietary supplements containing magnesium and zinc. The analysis examined the content of active substance and solubility in simulated gastric acid. The method used to analyze the active substance content was inductively coupled plasma optical emission spectrometry. This method was also used to determine the degree of solubility of the active substances. A total of thirteen different samples of dietary supplements were examined, all of which contained magnesium as the active ingredient and four of these samples additionally contained zinc. All samples contained the declared amount of magnesium. The zinc amount in food supplements was in accordance with the content stated on the label. In some samples the amount of zinc was determined to be lower, but the deviation from the declared amount did not exceed 14 %. Solubility tests have shown that some products do not contain a suitable type of coating to protect the active substance, which may cause a deterioration in bioavailability.
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Study of the content of risk elements in soils and plant material
Vlčková, Renáta ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
This bachelor thesis deals with the study of the content of selected heavy metals (Zn, Ni, Fe, Mn) in soils and mushrooms. The flame atomic absorption spectrometry method was used to determine the heavy metal content. Fungi and soil samples were collected at 18 sites in the Jeseníky region. The concentrations of heavy metals in the mushrooms were in the range from 140–582 mg/kg Zn, 48–380 mg/kg Fe, 5–19 mg/kg Mn and 3–8 mg/kg Ni. Zinc had the highest concentration value in all mushroom species. In soils, the concentrations of heavy metals ranged from 10–72 g/kg Fe, 52–1,000 mg/kg Mn, 29–115 mg/kg Zn and 6–50 mg/kg Ni. Iron was the most abundant element in the soils. Mushrooms contamination was assessed as a health risk in the study area. However, the pollution of forest soils was assessed as satisfactory and thus the productive function of the soil is not impaired. The type of forest cover was found to have minimal effect on the chemical composition of the soils.
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Possibilities of reducing zinc losses during heat treatment of ferrite ceramics
Buday, Patrik ; Šoukal, František (referee) ; Ptáček, Petr (advisor)
The diploma thesis is focused on the study of the influence of sintering temperature on the evaporation of zinc from Mn-Zn-ferrite ceramics. The main focus of the study is on the reaction kinetics of the zinc evaporation process, at the same time the aim of this work is to propose and verify a method that would limit the evaporation of zinc. The theoretical part summarizes the basic knowledge about the properties, classification, application, and production of Mn-Zn-ferrites. The end of the theoretical part describes the loss of zinc and a possible solution to this undesirable phonomenon. The beginning of the experimental part contains a summary of the principles of infrared spectroscopy, electron scanning microscopy, and X-ray crystallography. The experimental part of the diploma thesis is focused on the description of the production of ferrite samples, the characterization of the input material and the determination of the reaction kinetics of the sintering, and its comparison with the kinetics of the sample treated with a protective layer.
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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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Study of physiological changes in plants under stress by zinc ions
Adam, Rostislav ; Soudek, Petr (advisor) ; Petrová, Šárka (referee)
Heavy metals are part of us life for many centuries. Some of them are for living organism neccessary, but in large amount they have toxic effects. So we should decrease amount of heavy metals in the Environment. We have many way to do it. A relatively new way are the phytoremediation. If we would use the phytoremediation, we should know, what they do in plants. We must use specific plants, which are tolerant to certain heavy metal. If we would select a suitable plant, we have to try, how heavy metals in soil solution are toxic to plants. Zinc is no expection, although it is important part of many proteins. In plants it make rusty leaves and reduct aboveground and root biomass production. In hydroponic experiment I investigated that mallow Malva verticillata was very sensitive to low additon of Zn(NO3)2. The toxic efect appeared in 2 weeks. In sorghum Sorghum bicolor zinc show expressive toxic effect at concentration 1 mmol/l. I studied six cultivars of Sorghum bicolor, DSM 14-535, Expres, Honey Graze BMR, Nutri Honey, Sucrosorgho 506 and Sweet Virginia. According EC50 I as- sessed that the most sensitive was Sucrosorgho 506 and very tolerant were Nutri Honey and Sweet Virginia. Cultivar Nutri Honey was characteristic. It had the highest ratio concentration in shoot to concentration in root. I studied...
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Ability of copper chelators to interact with iron and zinc
Hanuščinová, Lucia ; Mladěnka, Přemysl (advisor) ; Čonka, Patrik (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Lucia Hanuščinová Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmDr., PhD. Title of diploma thesis: Ability of copper chelators to interact with iron and zinc Copper plays in the human organism a role of an element with indispensable significance, whose biological influence and effects depend on its quantity. With elevated concentrations in the human body, copper becomes toxic, resulting in pathological conditions. The most well-known diseases is the Wilson's disease, whose treatment consists of oral administration of chelators, i.e. chemical compounds, which are capable of binding copper ions in various proportions and eliminating them from the organism. Chelation therapy is currently the first choice after confirmation of the diagnosis. Chelation toxicity results from several factors, e.g. inhibition of copper dependent enzymes or low selectivity to metals. And precisely the selectivity of chelators is being discussed in this diploma thesis. An ideal chelator should not interact with any of the other physiological ions, that are necessary for the proper functioning of the organism. Five of the most frequently therapeutically or experimentally used substances /trientine, D-penicillamine,...
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Sol-gel synthesis of ternary ZnxTiyOz nanostructures for applications in solar cell technologies and photonics
Mrázek, Jan ; Nižňanský, Daniel (advisor) ; Pinkas, Jiří (referee) ; Pollert, Emil (referee)
The presented study deals with the sol-gel synthesis of nanocrystalline ternary phases of the general formula ZnxTiyOz, their characterization and potential application in photonics. Achieved results brings new fundamental knowledge about the processes leading to the formation of ZnxTiyOz nanocrystals from amorphous xerogels and gives novel information about structural and opto-electrical properties of prepared materials. Based on the presented results, most of all up-to-date reported ZnxTiyOz compounds with tailored nanocrystalline size and structure can be prepared as powders or thin films. Two sol-gel approaches based on the cluster process and direct heteronucleation were employed to prepare initial sol. Sols were optionally doped by Eu3+ ions to evaluate the effects of rare earth element to crystallization properties of formed compounds. In the first part of our study crystallization properties and structural evolution of thermally treated xerogels were analyzed. As a result a versatile method allowing the preparation of inverse spinel Zn2TiO4, cubic defect spinel ZnTiO3 and rhombohedral ZnTiO3 with tailored nanocrystal sizes was established. Initial composition and thermal annealing allow us to prepare selected ternary phase with tailored nanocrystal size ranging from tens of nanometers up to...
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Zinc induced activation of breast cancer cell lines and the involvement of Map kinase
Králová, Jarmila ; Čečková, Martina (advisor) ; Červený, Lukáš (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Jarmila Králová Supervisor: Dr. Kathryn Taylor, Ph.D., PharmDr. Martina Čečková, Ph.D. Title of diploma thesis: Zinc induced activation of breast cancer cell lines and the involvement of MAP kinase The aim of this work was to investigate the effect of zinc on various signalling pathways in breast carcinoma cell lines MCF7 and TamR cells. The differences between signalling pathways in MCF7 cell line and TamR cells were evaluated with a special focus on a role of MAP kinase, which activation is believed to be linked with malignant diseases. An effect of zinc on various cellular kinases in 0, 2, 5, 10, 15 and 20 minute of zinc treatment was analyzed in MCF7 cells transfected by wild and mutant type of ZIP 7, TamR cells and TamR cells pre-treated with MAP kinase inhibitor (PD) using the methods of western blotting and fluorescent microscopy. We show here the dependence of activation of pMAP kinase and other important oncogenic kinases (such as Lyn, Src and STAT3) on zinc release into cytoplasm. According to our results, MAP kinase is activated very upstream and it can stimulate many important protein kinases as Src Y418 , STAT3 S727 and Lyn Y396 in tamoxifen-resistant breast cancer...
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