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Metal-organic networks on graphene surfaces
Kurowská, Anna ; Průša, Stanislav (referee) ; Čechal, Jan (advisor)
Molecular self-assembly is a spontaneous association of molecules and atoms into well-defined supramolecular structures. Understanding this process is key for preparation of structures with atomic precision. This thesis studies the supramolecular structure of tetrakyanochinodimetan molecules (TCNQ) and iron atoms on graphene grown on iridium crystal with the (111) surface. The surface analysis was performed by scanning tunneling microscopy, low-energy electron microscopy and x-ray photoelectron spectroscopy. The thesis introduces the growth process of a good quality graphene on Ir(111) and the synthesis of Fe-TCNQ networks 20 nm x 20 nm large and describes their structural properties. Three preferential orientations of Fe-TCNQ on graphene were identified. The networks will be used in follow-up studies targeting their magnetic properties.
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Light diffraction and interference in laboratory exercises
Dvořák, Tomáš ; Šicner, Jiří (referee) ; Škarvada, Pavel (advisor)
The main purpose of this semestral project is suggestion and construction the laboratory task for measuring interference and diffraction of light, which would be teached in laboratory of physics. According to gained informations about optical phenomenon, the physical construction of the laboratory task was made. Subsequently the CMOS camera was connected and installed. There was also developed a software for controlling this camera. Software is able to control all supported functions of camera, capture and save samples from live recording and show the intensity decomposition of captured images. The most important function of developed software is ability to measure distances between particular diffraction local extremes.
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Modification of construction of the device for measuring laser light scattering from rough surfaces
Jaworková, Magdalena ; Klapetek, Petr (referee) ; Ohlídal, Miloslav (advisor)
This diploma thesis deals with a design modification of detection part of the laboratory instrument for measuring the topography of rough surfaces – laser goniometric scatterometer (SM II). Design modification is based on replacement of so far used detector instead for the detector of higher quality with better measurement parameters. The first part of the diploma thesis contains theoretical basics, which are necessary to understand the relationship between scalar diffraction theory and scattering measurements of monochromatic light. The emphasis is on the importance of choosing appropriate detection coordinates, which are affecting the aberrations of detected diffracted light. The practical part is dedicated to improving the sensitivity of the detection part of the scatterometer SM II that is used in The laboratory of coherence optics at IFE FME BUT. This part justifies the choice of the detector which predetermines both the use of optical elements and the overall design of the detection part as the goniometer.
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Design and testing of XRD holder for post-mortem analysis of li-ion battery electrodes performed in an inert atmosphere
Klvač, Ondřej ; Chladil, Ladislav (referee) ; Čech, Ondřej (advisor)
The work describes the design and manufacturing of a test device for post-mortem measurements of electrodes of electrochemical cells using X-ray diffraction spectroscopy. The theoretical part describes the diffractometer Rigaku Miniflex 600, for which the product is intended. At the same time, an overview of solutions in various applications is processed here in the form of a recherche. The practical part documents the current development of a new cell, on which tests were performed. Here is an overview of the influence of gases and insulating materials on the resulting data, especially distortion and attenuation. Subsequently, a new design with improved hermetic insulation and sample displacement error correction is described. The principle of operation of the manufactured cell, including the control unit and software, is elaborated in the form of technical documentation. Finally, the functionality is verified by comparing the diffractograms of the powder standards and the graphite electrodes.
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Simulation of Mach Zehnder interferometer
Rozsypal, Filip ; Münster, Petr (referee) ; Čučka, Milan (advisor)
This bachelor thesis deals with the simulations of Mach-Zehnder and Michelson interferometer. These simulations are realized by VPIphotoncs and MatLab. The thesis also describes the optical and physical phenomena, the usage and the principle of operation of interferometers and results of measurements with validation of the basic work of both interferometers.
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Measurement of the Mechanical Stability of Buildings and Consoles Used for the FSO Links
Kočvara, Pavel ; Němeček, Jiří (referee) ; Wilfert, Otakar (advisor)
The Master's thesis deals with the determination of measurement method of deflection the axis of the optical beam from its ideal position, which is caused by action of force of strong winds affecting the positional stability of the building or supporting structure (tower) used for placement of FSO links'heads. The thesis informs the readers about the other causes of deflection of beam axis in a real environment, about methods of determining the position of the beam axis in the plane perpendicular to the beam axis and the basic properties and parameters of the Gauss beams, including the phenomenon of diffraction on the output aperture of the laser transmitter.
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High Temperature Deformation Mechanisms
Heczko, Milan ; Gröger,, Roman (referee) ; Spätig, Philipp (referee) ; Kruml, Tomáš (advisor)
Dvě pokročilé vysoce legované austenitické oceli s Fe-Ni-Cr matricí byly studovány za podmínek nízkocyklové únavy jak za pokojové tak vysoké teploty. Široká škála experimentálních a charakterizačních nástrojů byla použita ke studiu vzájemně souvisejících aspektů zahrnujících chemické složení slitin, mikrostrukturu, deformační mechanismy a celkovou odezvu materiálů na externě působící zatížení. Klíčové mechanismy a faktory definující mechanické vlastnosti a výkonnost v reálném provozu byly analyzovány a diskutovány v souvislosti s materiálovým designem. • Standardní únavové experimenty byly provedeny za pokojové teploty a teploty 700°C. Byly získány křivky cyklického zpevnění/změkčení, cyklické deformační křivky, Coffin-Manson a Wöhlerovy křivky. • Ke studiu změn mikrostrukturního stavu slitin v důsledku cyklického zatěžování za pokojové a zvýšené teploty byla použita široká škála technik charakterizace pomocí elektronové mikroskopie. • Únavové chování, pevnost a cyklická plastická odezva studovaných materiálů byla vysvětlena v souvislosti s mikrostrukturními změnami a mikrostrukturními aspekty deformačních mechanismů jak za pokojové tak za zvýšených teplot. • Bylo zjištěno, že Sanicro 25 vykazuje nejvyšší pevnostní charakteristiky ze všech materiálů stejné třídy. Výjimečné vlastnosti této slitiny jsou spojeny s populacemi dvou typů nanočástic, koherentními precipitáty bohatými na měď a nanočásticemi typu MX s charakteristikou disperzoidu. Tyto nanočástice mají klíčový vliv na pevnost a celkovou cyklickou odezvu. V důsledku interakcí s precipitáty způsobujících zachytávání je pohyb dislokací v Sanicro 25 významně zpomalen, což vede k potlačení normálních procesů zotavení obvykle vedoucích ke změně uspořádání dislokační struktury tak, aby byla celková vnitřní energie systému co nejnižší. Takové uspořádání je tvořeno například dislokačními buňkami. Jelikož jsou procesy zotavení potlačeny, dislokační struktura za vysokých teplot je charakteristická homogenní distribucí dislokací o vysoké hustotě s velkou mírou vzájemných interakcí. V kombinaci s dalšími mechanismy zpevnění jako jsou precipitáty a substituční prvky v tuhém roztoku, tyto deformační mechanismy vedou k významnému zvýšení cyklické pevnosti za vysokých teplot.
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Fresnel Incoherent Correlation Holography (FINCH)
Bouchal, Petr ; Slabý, Tomáš (referee) ; Chmelík, Radim (advisor)
In the Bachelor's thesis, the recently proposed method known as Fresnel Incoherent Correlation Holography (FINCH) is examined both theoretically and experimentally. Its main advantage consists in a possibility to realize holographic reconstruction of 3D objects illuminated by incoherent light. In FINCH, the object recording is performed applying methods of optical holography and digital diffractive optics. The object reconstruction is realized numerically and utilizes principles of digital holography. In experiments, the modern optoelectronic devices known as Spatial Light Modulators are effectively used. The Bachelor's thesis includes a short review including description of the basic principles of FINCH but its own contribution consists in the mathematical description of the method and creation of the numerical simulation model in Matlab. The main result of the thesis is design and realization of experiments enabling verification of the method. In the Bachelor's thesis, results of two independent experiments realized with different types of Spatial Light Modulators HOLOEYE and HAMAMATSU are presented. An agreement of experimental results with theoretical predictions is very good. A short discussion of the obtained results, further research topics and FINCH applications is also included in the Bachelors's Thesis.
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Particle size of solid ash
Lochman, Petr ; Špiláček, Michal (referee) ; Hrnčířová, Michaela (advisor)
This bachelor thesis deals with possible ways of analyzing the size of solid particles of ash and their effect on the environment. The first half is devoted to combustion, ash formation and fuels, which are commonly used for energy production. The second half is devoted to a practical analysis of solid particles of different ash samples and their subsequent evaluation.
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Optical Field Evaluations for Hologram Synthesis
Fedorko, Matúš ; Polok, Lukáš (referee) ; Zemčík, Pavel (advisor)
The primary concern of this work is computer generated holography, in particular accelerating computation of synthetic holograms by means of modern-day massively parallel graphics chips. It starts by introducing fundamental holography principles together with mathematical and physical concepts behind it. Following discussion then deals with OpenCL, which is a relatively new, but well recognized standard for GP-GPU programming. Finally, the last two chapters of this work give an overview of problem analysis and its implementation in C++.
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