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Heat treatement of tool steels
Kubín, Matěj ; Moravčík, Igor (referee) ; Jan, Vít (advisor)
This thesis deals with heat treatment of tool steels. The work is divided into two parts. The theoretical part includes marking, properties and theoretical processing of tool steels. It also contains the technique which is used for sample preparation. In the experimental part there is an examination of the two common sold drills. Samples were made from the drill, on which metallographic analysis and heat treatment was performed.
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Composite Dental Biomaterials - Structure, Analysis and Properties
Matoušek, Aleš ; Vaněk,, Jiří (referee) ; Lapčík,, Lubomír (referee) ; Cihlář, Jaroslav (advisor)
The aim of this work is to define relations between grain size and bioaktivity of oxide ceramics, specifically ZrO2, Al2O3 and HA. Ceramic materials with grain size from 100 nm up to 10 m, with various surface roughness, were tested for its bioactivity. Ceramography analysis was performed for all tested materials to precisely describe microstructures. Biological properties of the ceramic materials were tested via dilation tests directly in-vitro and by in-vitro extraction. Three cell culturing lines: osteoblast MG63, fibroblast L929, and epithelioid HeLa, were used for our testing. An influence of the grain size on the biological response was only found for the ceramic materials which had been thermally etched. The thermally etched nanocrystalline samples had larger areas covered by cells than ceramics with coarse grain microstructure. Biological tests on layered composites Al2O3×ZrO2 showed the cell selection determined by the type of material, where ZrO2 surfaces were preferably covered. Improved biological response of nanocrystalline ZrO2 was demonstrated on ceramic ZrO2, Al2O3 and SiO2 substrates with nanocrystalline coating of ZrO2. In this work a novel technological process for the formation of defect-free coatings was developed. Sintered coatings were tested using in-vitro technique with cell line HeLa, L929 and MG63 for up to 72 hours. The results of the biological tests of nanocrystalline coatings were consistent with results from the bulk nanocrystalline thermally etched ZrO2 ceramics.
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Light microscopy and its applications
Pokorný, Pavel ; Prochazka, David (referee) ; Lošťák, Martin (advisor)
This bachelor´s thesis describes problems of light microscopy for readers. Part of this bachelor´s thesis is dedicated to basic terms of the light microscopy. Next chapters are dedicated to observing techniques - brightfield illumination, darkfield illumination, oblique illumination, Rheinberg illumination, phase contrast, differential interference contrast, polarized light microscopy and fluorescence illumination.
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Microscopy: tool for material analysis
Pleskalová, Kateřina ; Řehořek, Lukáš (referee) ; Čupera, Jan (advisor)
This thesis deals with description of the microscopic techniques that are used to analyse materials. The introductory part briefly summarizes the history of microscopy. The first part of the thesis is focused on light microscopy and the confocal microscopy technique is more elaborated here. The second part of the thesis is focused on basic techniques of electron microscopy, which means transmission electron microscopy and scanning electron microscopy. At the end of each chapter, there is summarization of limits and advantages of these techniques. The preparation of metallographic samples is also briefly described for these microscopic techniques.
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Novel cancer biomarkers derived from quantitative phase imaging of biopsy cells
Plišková, Diana ; Týč, Matěj (referee) ; Kolářová, Jana (advisor)
The main objective of this work is the development of novel cancer biomarkers usable in personalized treatments. To understand why this issue is important, a brief description of cancer, including statistical results over the past years, is provided. The work also describes individual methods of light microscopy that can be used in cell analysis and subsequent image processing consisting of segmentation, tracking, feature extraction and classification. In this work, the main cell features, such as cell motility and shape, are presented. These features can be potential biomarkers in the treatment of cancer.
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Heat treatment of iron alloys with carbon
Kubíček, Antonín ; Štěpánek, Roman (referee) ; Čupera, Jan (advisor)
This thesis deals with the processes of heat treatment, their impacts on microstructure of iron alloys with carbon and their influence on hardness of these alloys. In the research part of this thesis are discussed the alloys, which are found within the Fe-Fe3C metastable system, principles and technologies of heat treatment processing with focus on the annealing, methods of microstructure examination and hardness measurement. In the experimental part is documented and evaluated the influence of various types of annealing on hypoeutectoid and hypereutectoid steels and the influence of graphitization on the hypoeutectic cast iron. The evaluation involves comparison of microstructures obtained by light and scanning electron microscopy and comparing the hardness in the green state and after annealing.
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The influence of alloying elements n the hardenability of carburization steels
Komoráš, Miroslav ; Helán, Jiří (referee) ; Jan, Vít (advisor)
This bachelor thesis is dealing with material analysis of cams used in radial hydraulic motors. The goal of this bachelor thesis is to identify root causes for not proper quenching of some parts made of material 34Cr4 by using microstructure analysis and hardness measurement. Theoretical part of thesis looks into influence of alloying particles on quenchability of carburizing steels, methods of heat treatment and carburizing. Experimental part follows up microstructure analysis and case depth hardness of analysed samples.
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Surface acoustic wave microfluidic chip for rapid cell sorting
Vejrosta, Jakub ; Maňka, Tadeáš ; Plichta, Tomáš ; Šerý, Mojmír
This work revolves around microfluidics and micro-objects manipulation in general. In our device, we are producing surface acoustic wave (SAW). The SAW can be used to sort particles by their size or physical properties and separate them. In medical analysis SAW on microfluidic chip can be used to pre-sorting of body fluids or blood serum for further optical or chemical analysis. The wave is produced by pair of interdigital transducers (IDTs), which are situated on opposite sides of microfluidic channel. As our active material we have used lithium niobate crystalline material for its great piezoelectric properties. This work is also the precursor for measuring the rheological properties of a medium, such as micro-viscosity, via the measurement of the trajectory of a flow trace.
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Využití elektronové a světelné mikroskopie pro analýzu tvrdokovových návarů
Cerman, Miloš
The topic of utilizing electron and light microscopy for analyzing hard metal overlays offers wide research opportunities that can lead to valuable insights in the field of materials engineering. The goal of this final thesis is to evaluate suitable parameters for the welding current to create optimal structural phases that can resist abrasive wear to the maximum extent. The crucial factor is the influence of the mixing of the welding metal and the formation of carbide compounds that are resistant to increased mechanical stress. The methodological approach includes preparing samples from hard metal elec-trodes of ledeburitic and martensitic types and their subsequent analysis using electron and light microscopy. Modern imaging analysis methods will be utilized to obtain accu-rate results that will enable the determination of the chemical composition and amount of carbides in the overlays. The results show that the mixing of the welding metal not only affects the formation of carbides but also the creation of the metallic matrix where carbide compounds are stored. This matrix also significantly affects the resistance to wear, as unsuitable chemical composition causes the carbides to be pulled directly from their anchoring profile. The quality of the overlay is also analyzed using microhardness of structural phases and abrasive wear on a grinding cloth.
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