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Preparation and testing of SNOM probes
Bobek, Juraj ; Pavera, Michal (referee) ; Spousta, Jiří (advisor)
The area of research that deals with surface modification and preparation of nanostructures is still very unexplored. And only a little contribution to this field is discussed in this bachelor thesis. Its goal is to manufacture and to test a probe made off hollow optical fibre that is used in Scanning Probe Microscopy. Optical fibre parameters in combination with proper and unique techniques allow the breakthrough off very interesting applications. It's worth mentioning the gas injection in the proximity of the surface of a sample (GIS) and thus its modification by use of electrons (FEBID), ions (FIBID) or laser beams.
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The Use of AFM Measurement Method in Crystalline Silicon Solar Cells Technology
Mojrová, Barbora ; Boušek, Jaroslav (referee) ; Hégr, Ondřej (advisor)
This thesis deals with the use of Atomic Force Microscopy (AFM) and Kelvin Probe Force Microscopy (KPFM) in solar cells production. Both techniques measure surface properties using interactions between surface and tip that progressively scans entire surface of the sample. Atomic force microscopy allows three dimensional imaging of surface structure. Kelvin probe force microscopy is used to measure the contact potential difference on the sample surface. There are described experimental measurements of monocrystalline and multicrystalline substrates after various etching processes using AFM. By using KPFM the contact potential difference was measured on dielectric layers PSG, SiOX, SiNX and Al2O3 and on selective emitter structures. All experiments described in this work were carried out at the Solartec Ltd. workplace and they completely correspond with the actual technology of crystalline solar cells production.
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Assemblage and testing of the device for water ozonizing and its application for silicon wafer cleaning
Ředina, Dalibor ; Mikulík, Petr (referee) ; Voborný, Stanislav (advisor)
Deionised-ozonated water, so-called DIO3 appears to be an ideal alternative for usage in semiconductor industry. The utilisation of DIO3 for removal of photoresist from silicon wafers is faster, cheaper, and more environmental-friendly compared to classical technology based on mixture of sulphuric acid with hydrogen peroxide, so-called SPM. The diploma thesis deals firstly with research into ozone and ozonated water and their possible applications. Next sections describe two prototypes of generators for DIO3, that were assembled in CSVG a.s. Testing of parameters for generators on dissolved-ozone concentration is also a part of this thesis. Moreover, thesis involves tests, that were carrier out in ON Semiconductor in Rožnov pod Radhoštěm. These tests compare efficiency of cleaning by classical technology based on SPM and DIO3 approach.
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Noise and artifact suppression in fMRI data based on multi-echo data and independent component analysis
Pospíšil, Jan ; Gajdoš, Martin (referee) ; Mikl, Michal (advisor)
The main task of this work is to design an algorithm for suppressing unwanted noise and artifacts in fMRI data using the analysis of independent components and multi-echo data. The theoretical part deals with the basic principles of magnetic resonance, including construction and image data processing. The practical part presents a pilot design of a method inspired by a professional publication in the Matlab software environment, where this design is subsequently tested on real fMRI data provided by the Laboratory of Multimodal and Functional Imaging, CEITEC MU.
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Processing of MREG MRI data
Lampert, Frederik ; Mikl, Michal (referee) ; Gajdoš, Martin (advisor)
MR-encephalography (MREG) is an innovative method of ultrafast magnetic resonance imaging. Most of the publications about this method are concerning about acquisition and reconstruction of raw data. Studies dedicated to standardization of preprocessing MREG data have not been published yet, which led to motivation of creating this bachelor thesis. The main goal of this thesis is to set an optimal way of preprocessing MREG data, which could be advised for future studies utilizing this method. The main goal of this work was divided into several subgoals, consisting of making a literary review, implementation of general method for data preprocessing and suggesting an alternative ways of data preprocessing and their implementation into MATLAB programming language. Suggested ways of data preprocessing were evaluated by created criteria, described in this work. Results of the evaluation were discussed and interpreted by graphs. Based on the results of the evaluation, an optimal way for preprocessing data was set. It consists of movement and geometric distortion correction accomplished by SPM Realign & UNWARP function, spatial normalisation to EPI MNI template and spatial smoothing by Gaussian kernel.
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Nonlinear phenomena in optical fibers
Burian, Radek ; Horváth, Tomáš (referee) ; Münster, Petr (advisor)
The subject of this thesis is to describe nonlinear phenomena in the optic fiber. The theoretical part describes a principle of transmission in optical fibers. Optics modules, fibers and their parameters are described marginally. Except nonlinear phenomena, there is also described linear phenomena such as attenuation, dispersion, scattering. In terms of nonlinear phenomena there is described second order phenomena such as Second harmonic generation (SHG), Sum and difference harmonic generation (SFG and DFG) and third order phenomena, such as Kerr effect, Third harmonic generation (THG), Four-wave mixing (FWM) and Cross phase modulation (XPM). There are also described nonlinear scattering, such as Raman´s and Brillouin´s scattering. The Four-wave mixing is simulated in the first half of the practical part. Four-wave mixing occurs in DWMD systems, where can invoke cross-talks between channels. In the second half of the practical part is measured this nonlinear phenomenon. The aim of the measurement is to understand the behaviour of the FWM and find the way how to eliminate its power. The Four-wave mixing measurement is based on the simulation. Second measurement is designed for Brillouin scattering. The conclusion from simulated and laboratory part from both measurements are compared with theoretical knowledge.
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Multifunctional SNOM probes of new generation for correlative SEM/SPM measurements
Zezulka, Lukáš ; Kolíbal, Miroslav (referee) ; Spousta, Jiří (advisor)
Práce se věnuje návrhu multifunkční SNOM sondy pro korelativní SEM/SPM měření využívající dutého optického vlákna s plným jádrem. V rešerši jsou prozkoumány možné způsoby výroby SNOM hrotů na dutém optickém vlákně, využití dutých kapilár pro přívod pracovních tekutin ke vzorku a možnosti přívodu potenciálového rozdílu ke vzorku pomocí kapilár vyplněných vodivým materiálem. Dále je v práci prezentován vyvinutý způsob výroby unikátních SNOM hrotů a celý koncept je ověřen provedenými korelativními měřeními. Následně jsou diskutované problémy spojené s výrobou a měřeními.
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Tool for analysis of subject's movements in functional magnetic resonance measurements.
Šejnoha, Radim ; Lamoš, Martin (referee) ; Gajdoš, Martin (advisor)
This diploma thesis deals with an analysis of subject’s movement during measurements with funcional magnetic resonance imaging (fMRI). It focuses on methods of a movement artifacts detection and their removal in fMRI images. Thesis deals with metrics which are used for the movement rate of measured subjects evaluation. Metrics and a correction of movement are implemented into the programme in MATLAB. Comparison of subjects suffering from Parkinson’s disease with a group of healthy control was carried out. Tresholds of individual metrics were suggested and a criterion for the removal of subjects with high movement rate was determined.
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Mechanical excitation of self sensing SPM probes
Novotný, Ondřej ; Piastek, Jakub (referee) ; Pavera, Michal (advisor)
This bachelor thesis deals with the development of the SPM microscope probe holder which is designed for mechanical excitation of the probes. The first part of the thesis focuses on the description of physical theory, such as the principle of atomic force microscopy, the function of piezoceramics and the description of used quartz tunning fork based probes. The second part describes the gradual development and design of the new probe holder. Testing of the designed probe holder and comparison of mechanical and electric excitation is depicted at the end of this work. The designed probe holder was manufactured, the assembly procedure was described, and the drawings of the individual parts were created.
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Advanced SPM techniques for measuring electrical properties of materials
Kramář, Jan ; Konečný, Martin (referee) ; Pavera, Michal (advisor)
This bachelor thesis is concerned about development of local electric properties characterization technique of sample in contact mode of Atomic Force Microscopy. The research part describes the most expanded techniques of characterization of local electric properties using Scanning Probe Microscopy. For realization was chosen Scanning Spreading Resistance Microscopy. Important part of this technique is current amplifier. For that reason, operational amplifiers, circuits with them and implementation of new amplifier on microscop are described. Last chapter is dedicated to description of samples, which were used to test functionality of the amplifier and technique.
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