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Relationship between macro- and microscopic sings of alkali-silica reactivity in concrete
Burdová, Anna ; Přikryl, Richard (advisor) ; Martinec, Petr (referee)
This thesis deals with deterioration observed in cement-concrete cover (CBK) for three selected road sections of highways in the Czech Republic. The main objective was to determine whether concrete failure arose due to alkali-silica reaction, or other mechanism. The deterioration of concrete failure was observed in the macroscopic and microscopic scale. The mostly macroscopically observed deterioration of the concrete were cracks breaking the surface and inner parts of concrete. In micro- scale the microcracks and alcali-silica gels were observed. The CBK deterioration was quantitatively determined by three main parameters: specific length of microcracks on the CBK surface, specific length of microcracks in the drill cores and volume of alcali-silica gels and microcracks in thin sections. According to these indicators it was possible to distinguish two different types of CBK deteriorations. (1) Degradation mainly associated by alkali-silica reaction (observed on highways D11 - Vrbová Lhota and D1) and (2) degradation connected with another mechanism (cycles of freezing and thawing, mechanical degradation) was observed on the highway D5.
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Preparation of ultra sharp tips for STM TERS applications
Šilhan, Lukáš ; Man, Ondřej (referee) ; Jan, Vít (advisor)
The goal of this bachelor thesis is preparation of Au tips by electrochemical etching. The theoretical part deals with comparison of microscopy techniques for materials surface characterization and Raman spectroscopy. The experimental part is focused on the settings of optimal etching parametres to gain appropriate geometry of fabricated tips. Function of tips is verified by evaluation of data gained by experimental measuring with this tips. Prepared tips are suitable for applications such as STM and TERS.
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Three-Dimensional Reconstruction of Image in Digital Holographic Microscopy
Týč, Matěj ; Karásek,, Vítězslav (referee) ; Martišek, Dalibor (referee) ; Chmelík, Radim (advisor)
This thesis deals with the topic of 3D image processing for digital holographic microscopy - numerical refocusing. This method allows to perform mathematically accurate defocus correction on image of a sample captured away from the sample plane and it was applicable only for images that were made made using coherent illumination source. It has been generalized to a form in which it is also applicable to devices that use incoherent (non-monochromatic or extended) illumination sources. Another presented achievement concerns hologram processing. The advanced hologram processing method enables obtaining more data mainly concerning precision of quantities from one hologram — normally, one would have to capture multiple holograms to get those. Both methods have been verified experimentally.
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Three-dimensional reconstruction of image in digital holographic microscopy
Týč, Matěj ; Chmelík, Radim (advisor)
This thesis deals with the topic of 3D image processing for digital holographic microscopy - numerical refocusing. This method allows to perform mathematically accurate defocus correction on image of a sample captured away from the sample plane and it was applicable only for images that were made made using coherent illumination source. It has been generalized to a form in which it is also applicable to devices that use incoherent (non-monochromatic or extended) illumination sources. Another presented achievement concerns hologram processing. The advanced hologram processing method enables obtaining more data mainly concerning precision of quantities from one hologram — normally, one would have to capture multiple holograms to get those. Both methods have been verified experimentally.
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Design of electron microscope
Havlíček, Petr ; Kobosil, Karel (referee) ; Zvonek, Miroslav (advisor)
The aim of my Master's thesis is the design of a scanning electron microscope. The designed concept presents an innovative approach to the problems and respects all technical, ergonomic and aesthetical demands made on it. The main creative part of design process starting from the concept development and ending up with the final solution is preceded by a background research study including a historical, technical and design analysis of the electron microscope. The conclusion of my Master's thesis analyses the final design, its character and its contribution in broader context.
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Accuracy of measurement on workshop microscope
Pernikář, Václav ; Jarošová, Jana (referee) ; Bumbálek, Leoš (advisor)
This thesis deals with the performance of the measurement accuracy in the optical measuring systems. The first part describes basic principles of metrology and the guidelines of the expression of uncertainty and the factors which influence measurement result. The second part classifies optical measuring systems and describes some measuring principles of them. The final part compares two optical gauges and the evaluation of some of their characteristics through the use of very simple experiments.
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The Influence of Fines on Pore System of Concrete
Elfmarková, Veronika ; Smolka, Hynek (referee) ; Hela, Rudolf (advisor)
Literature does not provide a satisfactory answer to maximum and minimum particle size or the particle size of the mortar phase especially for optimal porosity of concrete. To overcome the shortcomings of the design methods were thought to design a new method for design of concrete mix. This idea is based on a complex analysis of powder materials (determination of granular properties, shape factor of fillers, porosity, packing of powder materials, surface area, etc.) and subsequently to assess the influence to pore system of concrete and physical and mechanical properties in hardened state of concrete. In this work are presented and analyzed two types of fillers – fly ash and limestone dust.
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Contrast in image acquired by ionization detector in VP SEM
Goroš, Pavel ; Čudek, Pavel (referee) ; Jirák, Josef (advisor)
This work deal with problems of investigation materials electron beam. This project is focuses on investigation materials by the help of method environmental scan electron microscopy (ESEM) and describes her patterns. The perfection of ESEM excel above all at studies non - conducting or water containing, often biological samples. These samples not to be in no way prepared or cut – and – dries, in contradistinction to classical scanning electron microscope and thanks is under investigation their native surface structure without desiccation breaking. The general aim is determination of contrast in image acquired by ionization detector.
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Phosphate binders
Kalina, Lukáš ; Ptáček, Petr (referee) ; Šoukal, František (advisor)
The work deals with the preparation and study of polyphosphate composites. Aluminum phosphates provide some unusual properties like high-heat resistance in terms of inorganic binders. The addition of chromium in the form of Cr2O3 or directly the bond with the aluminum-chromium-phosphate can improve the properties of this binder. Highly viscous Al2Cr(H2PO4)9 and Al3Cr(H2PO4)12 binders were prepared by dissolving Al(OH)3 and CrO3 in 85% phosphoric acid, and mixed with Al2O3 and Cr2O3 fillers. The composites were cured in the furnace at 150 °C for 24 h under pressure of 10 MPa. During the annealing at temperatures up to 1 500 °C changes in chemical structure of the cured composites were observed, leading to the understanding of the creation of crystalline phases and their eventual changes. The characterization of binders was mainly based on FT-IR, EDAX, TG-DTA and optical microscopy analyses.
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Interactions of aminoclays with natural polyelectrolytes
Jančík Procházková, Anna ; Mravec, Filip (referee) ; Pekař, Miloslav (advisor)
This thesis deals with the preparation of products of interactions of aminoclay with natural polyelectrolytes. Sodium hyaluronate was chosen as the natural polyelectrolyte. The concentration and volume ratio of solutions of aminoclay and natural polyelectrolyte which led to the formation of any type of product were studied. The resulting coagulates were characterized by microscopy, FTIR spectroscopy and rheology. Furthermore the possibility of interactions with fluorescent probes was studied.
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