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Aplication of SPM in study and modification of ultrathin films Pt, Co and graphene
Lišková, Zuzana ; Červenka,, Jiří (referee) ; Bartošík, Miroslav (advisor)
This diploma thesis deals with the preparation of the very thin films and their investigation by scanning probe microscopy methods. The ultrathin films of Pt on Pt(111) were created by pulsed laser deposition and the ultrathin films of Co on Pt(111) were deposited by thermal evaporation. The coverage of the substrate was much smaller than one monolayer (in order of hundredths of monolayer). The nucleation theory was verified by these experiments using so-called Onset method. Further graphene sheets were prepared on layer of Si/SiO2 by the mechanical exfoliation from the graphite crystal. The fabricated graphene sheets were studied by micro-Raman spectroscopy, microreflectometry, atomic force microscopy and similar techniques. These methods proved the thinnest graphite layers were consisted of two graphene monolayers.
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Visualization and export outputs from functional magnetic resonance imaging
Přibyl, Jakub ; Gajdoš, Martin (referee) ; Slavíček, Tomáš (advisor)
Thesis discusses the principles and methodology for measuring functional magnetic resonance imaging (fMRI), basically the origin and use of BOLD signal types used experiments. Further attention is paid fMRI data processing and statistical analysis. Subsequent chapters are devoted to a brief description of the most common software tools used to analyze data from fMRI. The main section was to create a program in MATLAB with a detailed graphic user interface for easy visualization and export output from analyzes of fMRI data. The second half is devoted to describing the program developer and graphic user interface, including key functionality. The final section describes the application program with real data from clinical studies of dynamic connectivity and use in an international project APGem.
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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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A comparison of effective and functional connectivity methods in fMRI
Gajdoš, Martin ; Schwarz, Daniel (referee) ; Jan, Jiří (advisor)
Functional magnetic resonance imaging (fMRI) is recent important method, used in neuroimaging. The aim of this thesis is to develop software tool for comparison of two methods for functional and effective connectivity estimation. In this thesis are described the basics of magnetic resonance imaging, fMRI, basic terms of fMRI experiments and generally are described methods of functional and effective connectivity. Then are more detailed mentioned methods of dynamic causal modeling (DCM), Granger causal modeling (GCM) and independent component analysis (ICA). Practical implementation of DCM in toolbox SMP and ICA in toolbox GIFT is also mentioned. In purpose to describe behavior of DCM and GCM in dependence on several parameters are performed Monte Carlo simulations. Then the concept and realization of software tool for simulating connectivity and comparison of DCM and GCM are described. Finally results of DCM and GCM comparison and results of Monte Carlo simulations are discussed.
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Non-linear character of optical environment
Žáček, Martin ; Míča, Ivan (referee) ; Přinosil, Jiří (advisor)
This paper describes theoretical and application options of nonlinear effects in optical medium. Optical medium means fiber optics, because the fiber is the most employed optical medium at these days. Basic statements of this work are theoretical information with mathematical and physical expressions. These expressions defines nonlinear medium and effects which are founded here. These effects are split to second and third orders. Nonlinear effects of second orders are Second-harmonic Generation, Three-wave Mixing process. Nonlinear effects third orders are Third-harmonic Generation, Self-phase Modulation, Cross-phase Modulation, Four-wave Mixing and Degenerative Four-wave Mixing process. These effects are extended by scattering effects – Brillouin’s and Raman‘s Scattering. The next point discuss about optical communication system DWDM. DWDM uses dense wavelength multiplexing. Nonlinear effects have a few negative influences on these systems. There are requests for high bandwidth and communication speed. FWM and XPM limit these requests. They can invoke cross-talks. We support theoretical information with application examples and simulations at the end of this work. We use OptSim v.4.0 program. We are simulate FWM and XPM effect in depend on chromatical dispersion and power.
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Software for patients and brain regions selection suitable for analysis of connectivity in fMRI
Slavíček, Tomáš ; Lamoš, Martin (referee) ; Jan, Jiří (advisor)
The aim of this thesis is to create an exploratory tool for functional magnetic resonance imaging data, which allows quickly and easily making a selection of persons and areas suitable for group analysis of connectivity. In the first chapters of this work is mentioned history of brain research and comparison of methods used in functional imaging. Next they are discussed the theoretical basis of fMRI methods, such as the formation of BOLD signal, acquisition parameters of MRI images and methods for designing experiments. The following chapter describes in detail the analysis of recorded data from the pre-processing to the interpretation of results. The last chapter of the first part describes problems of group analysis in SPM8 software. The second half of this work is dedicated to the description of developed program from data input to saving the results, including detailed descriptions of key features. In conclusion, there is a chapter characterizing the application of developed program on real data from clinical studies, including the results and evaluation of the usability of program. The program will mainly be used in neuroscience research.
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Local characterization of electronic devices
Müller, Pavel ; Škarvada, Pavel (referee) ; Tománek, Pavel (advisor)
The development of micro and nanoelectronics and nanophotonics needs novel characterization techniques to ensure higher quality of designed devices. The thesis describes a use of Scanning Near-field Optical Microscopy (SNOM) in dimensional control and in local investigation of diverse physical parameters. As example of its potential, the correlation between object topography and reflection measurement of capacitors is shown.
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Improvement of control and analysis techniques of a SPM model
Štefko, Marcel ; Nováček, Zdeněk (referee) ; Šulc, Dalibor (advisor)
Bakalářská práce se zabývá zdokonalováním výukového modelu mikroskopu atomárních sil (AFM). Součástí práce je rešerše stávajících analogii mezi makroskopickými jevy a fenomény spojenými s mikroskopii rastrovací sondou. Dále byla vybrána vhodná analogie, která byla následně implementována do již existujícího modelu mikroskopu atomárních sil. Do modelu byl integrován i jednodeskový počítač, který zajistí ovládání i bez nutnosti připojení externího počítače. Na závěr byly vyhodnoceny vlastnosti použité sondy a analogie mezi modelem a skutečnými mikroskopy atomárních sil.
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Preparation and analysis of nanostructures in UHV conditions
Gloss, Jonáš ; Spousta, Jiří (referee) ; Mach, Jindřich (advisor)
Cílem této bakalářské práce bylo skoumání přípravy a analýzy nanostruktur v podmínkách vysokého vakua (VV). Teoretická část klade důraz na gallium nitridové (GaN) nanostruktury. Ty pak byly analyzovány rastrovacím tunelovacím mikroskopem (RTM). Aby bylo možné analyzovat připravené vzorky ve VV RTM, bylo provedeno elektrochemické leptání wolfrámového drátu. Tato práce zhrnuje postup k vytvoření wolfrámových hrotů pro RTM. Kapitola o výrobě wolfrámových hrotů zahrnuje popis princípu elektrochemického leptání. Obrázky vyleptaných hrotů byly provedeny pomocí rastrovacího elektronového mikroskopu. Zaostřování hrotů pak bylo vykonáno fokusovaným iontovým svazkem. V této práci je také představena metoda pro opětovné ostření RTM hrotů elektronovým svazkem, vykonávaná in-situ. Bylo dokázáno, že je možné rutinně obdržet wolfrámové hroty s poloměrem křivosti rádovo v nanometrech.
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Computer processing of tomography data
KONEČNÝ, Jan
Computer processing of tomography data Tomographs are one of the most important diagnostic devices, which are used in every hospital nowadays; they have already been so for a considerable period of time. The different types of tomographs and the processing of tomographic data and imaging of these data are the subject of this thesis. I have described the four most common types of tomography: X-ray Computed Tomography, Magnetic Resonance Imaging, Positron Emission Tomography and Single Photon Emission Computed Tomography. This thesis has described the basic principles of these devices, their technical parameters, their use and also different data formats, which are used for tomographic data. The practical part of my thesis is involved with software for viewing and processing of tomographic data. It specifically concerns freely available viewers such as MRIcro, ezDICOM, Amide, ImageJ and Gpetview. Their main functions and their pros and cons have also been described therein. The last part of my thesis has been devoted to SPM software that is used for an advanced processing of 3D tomographic data from PET, VBM and MRI as well as EEG and MEG imaging techniques. I have described these features and also those individual steps that are taken during the processing of particular sample data that has been taken from examinations on functional Magnetic Resonance Imaging. This thesis is addressed to all, those who want to learn more about tomographic data processing and mainly it should serve as an overview of free software for processing and viewing of these data.
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