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Optical characterization of advanced nanomaterials with a high lateral resolution
Liška, Petr ; Münz, Filip (referee) ; Dvořák, Petr (advisor)
Advanced nanomaterials show a significant improvement in certain physical or functional properties compared to conventional materials. Such advanced materials are, for example, lead halide perovskites (LHP). It is a group of hybrid organic-inorganic materials with a direct bandgap exhibiting unique optical properties. The high quantum efficiency of photoluminescence makes nanocrystals or thin films of LHP suitable candidates for the production of light-emitting diodes, solar cells and LCD displays. Their inexpensive and simple fabrication together with their unique optical properties makes LHP one of the most developed materials of the last decade. This diploma thesis aims to study the optical properties of CsPbBr3 perovskite nanocrystals using high lateral resolution methods. CsPbBr3 perovskite nanocrystals show intense anti-Stokes photoluminescence. These nanocrystals can emit light with a lower wavelength than that of the light that causes their photoluminescence. The nanocrystals are prepared in two different ways: by evaporation or by crystallization of the precursor in a solution of dimethylformamide. The morphology, photoluminescence properties and chemical composition of individual nanocrystals are studied. Each nanocrystal is studied individually and its size, shape, photoluminescence properties and chemical compounds are determined, which leads to a deeper understanding of the anti-Stokes photoluminescence of perovskite nanocrystals.
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Study of elektrode materials based on manganese dioxide
Kos, Lukáš ; Dvořák, Petr (referee) ; Novák, Vítězslav (advisor)
This work deals with the production and use of catalytic materials in fuel cells. The basic focus of work is the production of samples of catalytic materials based on manganese dioxide-enriched mixtures of different dopants. Samples subsequently made to measure, compare with other samples and determine whether the samples are enriched with dopants better than samples without dopant. According to information received, then determine whether they are suitable for use in fuel cells.
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Supercapacitor cycling device
Hába, Roman ; Kunovjánek, Miroslav (referee) ; Dvořák, Petr (advisor)
The supercapacitor is a perspective electrical component reaching very large capacity. Currently is beeing worked on improving its parameters. These parameters are needed to test. Charging and discharging of the supercapacitor is theoretically fully reversible process. However, real supercapacitor accompanies ageing of the electrolyte and electrodes, lead to reduction of the capacity. The aim of this work is to design a device that expose supercapacitor to accelerated ageing, which will facilitate the assessment of ageing commercial and laboratory made supercapacitors.
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The Business Plan for the Development of Small Business
Dvořák, Petr ; Kozák, Petr (referee) ; Bayerová, Vladimíra (advisor)
This thesis deals with the suggestion of a business plan, which is used for the development of small business. The thesis analyzes the present situation of the company by analyzing of the internal and external surroundings. The aim is to suggest changes and choose the appropriate strategy for the development of small business. The proposal is analyze the possibility of transformation of the business entity to a limited liability company and the possibility of obtaining the operating and investment loan.
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Matched Filter
Dvořák, Petr ; Sysel, Petr (referee) ; Číž, Radim (advisor)
The main objective of this work is to study methods of reducing BER and suggest possible resolution of matched filter. In the first part, the methods are theoretically analyzed and subsequently their function models are sugested in the computer programme Matlab Simulink. On these models, the behaviour for different input values is simulated and on their basis, the output depending on probability of the false income on SNR for each of models is worked out. In the second part, the design of the laboratory preparation with a view to the matched filter is described. This suggestion is divided into the parts which are subsequently described and outputs from the implementation of the suggested resolution are added. Thereinafter, the implementation of the proposed resolution and the results achieved at measurement of the realized produkt are closely described. This product is to be made for educational and laboratory purposes in terms of lessons The Theory of Communication.
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Study of Properties of Surface Plasmon Polariton by Using Scanning Near-Field Optical Microscopy
Neuman, Tomáš ; Kalousek, Radek (referee) ; Dvořák, Petr (advisor)
This bachelor`s thesis deals with the study of properties of surface plasmon polaritons (SPPs) propagating along the metal - dielectric interface. The interference of SPPs was experimentally examined by a scanning near-field optical microscope (SNOM) on plasmonic structures prepared by focused ion beam (FIB) etching. Interference patterns caused by SPPs propagating from prepared excitation slits were observed. Detected interference patterns were theoretically discussed. Finally, the sensitivity of the SPP coupling on the polarization of the excitation laser beam was experimentally confirmed.
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The equipment of social care at Svitavy – building technology design
Dvořák, Petr ; Hrůza,, Jaroslav (referee) ; Hrazdil, Václav (advisor)
Diploma thesis deals with a building technological project – Social care Institucion in Svitavy. It is about a new building of retimerent home with ground plan creating a letter „ U“. The building is dilated into 3 parts: Unit „A“,Unit „B“, Unit „C“. The aim of diploma thesis is construction desing which covers site facilities technological standart, inspecting and testing plan, time and finenciel plan.A part of thesis is also specializacion in thermal protection cres.
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Wireless temperature sensor with high temperature warning indicator
Dvořák, Petr ; Petržela, Jiří (referee) ; Hruboš, Zdeněk (advisor)
This thesis deals with a proposal of a wireless temperature-sensitive element at high temperature. It analyses some different variants of the temperature sensors. Furthermore, the thesis describes the Industry Science Medical (ISM) bands, in which it will be possible to communicate with the wireless communication modules. These wireless modules are discussed and described. By the devices „the transmitter and the receiver" it is focused on the communication of the microcontroller Atmel with the wireless modules, with the temperature sensors, microswitches on the control and display unit (LCD).
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Small Unmanned Aerial Vehicle for vegetation monitoring
Trojánek, Tomáš ; Pejchar, Jan (referee) ; Dvořák, Petr (advisor)
The aim of this thesis was to select the most appropriate platforms for the fulfillment of required flight mission. The first part reviews available unmanned vehicles suitable for vegetation monitoring and includes both commercially available and self-made types. There are presented basic parameters, recommended equipment and tested configuration of each platform. The second part includes graphical comparison of all models in different categories and the most suitable platform has been selected on its basis. The model project which is based on the selected platform is presented in the final section.
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Nanophotonics
Dvořák, Petr ; Rezek, Bohuslav (referee) ; PhD, Jakub Dostálek, (referee) ; Šikola, Tomáš (advisor)
This thesis deals with an experimental research of the surface plasmon polaritons (SPPs) using Scanning Near-field Optical Microscopy (SNOM). The first chapter provides theoretical background and a description of most of the physical phenomena and relevant dependencies studied in this work. These dependencies include the dependence of the resulting SPP image on homogeneity, polarization, wavelength and phase of the illumination, on the geometry of the interference structures and on the tilt of the sample with respect to the illumination. Further, this work presents a new experimental method which, using the numerical simulations or SNOM measurements, allows to estimate the sensitivity of SNOM probe to detect the individual electric intensity components of the near-field. At the end of the thesis, the work presents a new microscopic technique which enables a 3D quantitative imaging of phase distribution above the plasmonic metasurfaces.
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