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Factors affecting the quality of machined surfaces after milling operation
Černý, Libor ; Jaroš, Aleš (referee) ; Fiala, Zdeněk (advisor)
This diploma thesis deals with the final quality of the surface under variable working conditions during milling. The first part deals with the definition of qualitative parameters describing surface properties. This is followed by a brief description of the cutting resistance measurements. The thesis is complemented by experimental verification using front milling and its evaluation. The aim of the experiment is to determine the dependence of the surface quality and the size of cutting resistors under the variable working conditions of the machine that do not make a common part of the manufacturing processes.
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Characterization of ultra-thin polymer films on solid substrates using different physical techniques
Pop-Georgievski, Ognen ; Rypáček, František (advisor) ; Adam, Pavel (referee) ; Werner, Carsten (referee)
The presented doctoral research was aimed at preparation and characterization of ultra thin polymer films on solid substrates using different physical techniques. Each of these physical techniques probes selectively different characteristics of the films. While some of the techniques are strong in the predetermination of some unique properties of the layers, they might be limited and give no specific/conclusive information about some other important characteristics. Therefore, only the combination of the techniques provides a profound picture of the thickness, architecture, composition and functionality of the films/layers. This combined characterization approach elucidates in details the physical characteristics and the mechanisms responsible for the unique behavior of different polymer films/layers in the application that they are intended for. In the thesis, of particular interest were films of high biomedical, biotechnological and tissue engineering importance, such as: 1. poly(lactide) films formed by grafting "from-" a silanized alacrite thin films (L605 Co-based super alloy), 2. polydopamine (PDA) films that could serve as substrate independent mod- ification platform for further surface modification steps, 3. poly(ethylene oxide)films formed by "grafting to-" PDA modified surfaces, 4....
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Study of chemical cleaning of surfaces by LEIS method
Staněk, Jan ; Polčák, Josef (referee) ; Bábor, Petr (advisor)
This thesis deal with studying chemical etched surfaces of cadmium telluride crystals (CdTe crystals) by low-energy ion scattering spectroscopy (LEIS method). In the theoretical part, there is description of physical essence of LEIS method, including experimental arrangement of Qtac100 instrument, on which the experiment is measured. The LEIS method is also compared with X-ray photoelectron spectroscopy (XPS). There is summary of properties and structure of CdTe crystals including principle of X-ray detectors, which are the primary use of the crystals. In experimental part there is a description of measuring process, starting with a calibration measurement, ongoing with a chemical etching and ending with a surface analysis. There are examples of LEIS spectra with comments and interpretation including comparison with XPS data.
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Surface analysis using low-coherence interferometry
Pikálek, Tomáš ; Novák, Jiří (referee) ; Buchta, Zdeněk (advisor)
This thesis deals with low-coherence interferometry, laser interferometry and its combination intended to be used for contactless surface analysis. It outlines theoretical background of laser interferometry and low-coherence interferometry and describes in detail interference fringe center detection techniques used in low-coherence interferometry and their implementation into MATLAB environment. All these techniques theoretically described were analyzed to evaluate their measurement accuracy, resistance to optical dispersion and computational complexity in order to choose the most appropriate technique to be involved into the experiment. Furthermore, the thesis describes design of an experimental setup for optical surface analysis combining laser interferometry and low-coherence interferometry. There are presented experimental results and its comparison with the reference measurement. Overall measurement uncertainty is calculated and discussed too.
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Computer controlled SEM with Schottky cathode for imaging in slow and Auger electrons
Hrnčiřík, Petr ; Müllerová, Ilona
The ultrahighvacuum Scanning Electron Microscope has been built using the column of an old prototype (later produced as Tesla BS 350), some spare parts for BS 350 and new components, including computer controlled electronics. The whole vacuum system was extensively reconstructed, too. The Schottky cathode was introduced into the microscope instead of the original cold field emission gun. The advantage of this system includes a high current density, higher stability and lower vacuum demands at comparable performance as regards the resolution. Therefore it is possible to practice surface analysis with Auger electrons at a high resolution. The microscope was also adapted to the operation with slow and very slow electrons, again at high resolution, so that these two methods can be in situ compared.
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