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Interference in the photochemical generation of volatile Se species using TiO2 photocatalyst
Nentvich, Daniel ; Nováková, Eliška (advisor) ; Hraníček, Jakub (referee)
The diploma thesis deals with the study of interferences in the method of UV-photochemical vapour generation of volatile Se species in formic acid media catalysed by nanocrystalline titanium dioxide. High resolution continuum source atomic absorption spectrometry was used for detection. It was observed that SeVI was less resistant to pH change relative to SeIV , while at pH = 2.3, a 20% increase in response was observed for this specie. It was further observed that both the generated volatile SeIV and SeVI species are resistant to UV radiation in the gas phase. The Cu2+ and Ag+ ions were particularly significant interferents in the SeIV determination. Interference behaviour was also observed for Cd2+ ions and silver nanoparticles. In the case of Cd2+ ions, the generation of cadmium selenide was likely observed. For Zn2+ , Fe2+ , Co2+ ions, there was an increase in response of more than 30% and 40%, in case of Ni2+ ions. The Co2+ and Ni2+ ions were chosen as reaction modifiers. For the UV-photochemical vapour generation of selenium species with photocatalyst and reaction modifiers, there was a 4-fold improvement in detection limits and limits of quantification compared to the method without these modifiers. In addition, the overall generation efficiencies for SeIV (64.7 %) and SeVI (68.6 %) were...
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Demonstration kit for fiber optic sensing system
Beránek, Karel ; Klíčník, Ondřej (referee) ; Dejdar, Petr (advisor)
This bachelor thesis focuses on the design and implementation of a~demonstration kit for a~fiber optic sensing system. The thesis includes a~theoretical analysis of optical phenomena such as polarization, dispersion, and interference, which are crucial to understanding the principles of fiber optic sensors. The designed sensing system comprises a~Mach-Zehnder interferometer, a~UP-Board development kit, an external 24-bit sound card, and a~touch display. The practical part of the thesis is focused on the construction of the enclosure using 3D printing, the integration of individual components, the design of a~custom application, and the testing of the system. The results of this work contribute to the development of knowledge in the field of fiber optic sensors and can be utilized in both academic and industrial settings.
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Effect of electromagnetic compatibility on the operation of automotive LED drivers
Vinklerová, Viktorie ; Šteffan, Pavel (referee) ; Levek, Vladimír (advisor)
The diploma thesis deals with electromagnetic compatibility, its bonds, measuring devices and interference sensors. Furthermore, the thesis includes a discussion of nearfield probes, standards CISPR25 and TEM chamber methods. It describes two integrated circuits NCV78964 and NCV78514 LED drivers from onsemi and their modules. The aim of the work is to design the measurements, then to implement and evaluate them. Finally, to optimize the operating parameters of the drivers with respect to both EMC and driver functionality.
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Fiber Optic Michelson Interferometer
Dorazin, David
The aim of this paper is to theoretically desribe function of the Optic fiber Michelson interferometer and its parts with description of the most important issues which can occure due to bad design. Second part of this paper is dedicated to simulation of the optic fiber Michelson interefometer in professional simulation software VPIphotonics.
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Coexistence of LoRa and Wi-Fi in the RF band 2.4 GHz
Kaučiarik, Filip ; Miloš, Jiří (referee) ; Polák, Ladislav (advisor)
Diplomová práca sa zaoberá štúdiom koexistencie, ktorá môže nastať medzi bezdrôtovými komunikačnými systémami LoRa a Wi-Fi v bezlicenčnom ISM pásme 2,4 GHz. V teoretickej časti práce sú stručne popísané fyzické vrstvy obidvoch systémov. Následne sú definované spoločné frekvenčné pásma a koexistenčné scenáre, ktoré môžu vzniknúť medzi uvažovanými systémami v spoločnom rádiofrekvenčnom (RF) pásme. V experimentálnej časti práce je prezentované laboratórne meracie pracovisko, ktoré bolo navrhnuté na meranie rôznych koexistenčných scenárov medzi technológiou LoRa a Wi-Fi. Funkčnosť navrhnutej koncepcie je overená experimentálnym meraním. Výsledky meraní sú detailne komentované a prezentované. Je navrhnutá laboratórna úloha a vzorový protokol pre vzdelávacie účely v Laboratóriu Mobilných a Bezdrôtových komunikácií.
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Michelson's interferometer
Rýc, Jan ; Klusáček, Stanislav (referee) ; Havránek, Zdeněk (advisor)
The diploma work deals with techniques of optical contactless distance and velocity measurement. A basic summary of the methods are involved. The problematic of interferometric methods for vibration measurements is analysed in detail. It contains division of interferometers, description of their function principles and also chapters dealing with elements used in interferometers such as lasers, photodetectors and elements in the ray optical way - polarizers, retarders, optical isolators. The vibration and length measurement methods are described, as well as the conception of homodyne and heterodyne detection. Part of this work focuses on the quadrature signal processing and on the proposal of algorithm for demodulation of velocity/displacement and undergoing simple motioning object deviation. This algorithm is implemented in Labview and the whole software instrument served also for visualisation of measured data of the interferometer model constructed in the laboratory. The way how to build up a model, its setting and two possible configurations suitable for homodyne detection are described. Model of interferometer is built-up on the optical breadboard. Particular components are fixed by the help of mounts. The model and software enable to measure the velocity and the vibration deviation with the light wavelength exactness. Functionality and the exactness of the laboratory model are verified by vibrometer. Effects on the measurement uncertainty are discussed here and ways how to restrain them are proposed.
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Electromagnetic interference and pacemakers
Kulík, Jindřich ; Richter, Miloslav (referee) ; Havlíková, Marie (advisor)
This thesis deals with electromagnetic compatibility of implantable electro-medical devices using in cardiology. The main aim of this thesis is detection of the resistance of implantable pacemakers (PM) and implantable cardioverter defibrillators (ICD) to the electromagnetic interference. In the first part of this thesis, a function of the heart, which is necessary for understanding of PM and ICD operation, is described. The function and construction of PM and ICD is detailed in the theoretical part as well. The next part is focused on the electromagnetic compatibility. The next part is description of the measurement method and the experimental arrangement used for practical experiments with electromagnetic resistance of PM and ICD.
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Radio Access Network of a Cellular Network
Duda, Michal ; Novotný, Vít (referee) ; Krkoš, Radko (advisor)
The aim of the work is the radio access network of mobile networks second, third and fourth generation. The main objective is a description of the radio access network of the second, third and fourth generation, their elements, interfaces and signaling procedures. The next part describes the emergency services and the architecture of the fourth generation mobile networks. The practical part is then devoted to identify actions needed to prepare radio access network to testing emergency services, identify actions needed to conversion of transport protocol fixed part of the radio access network from IPv4 to IPv6 and describe the intervention to radio access network to change the active segment of the core network.
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