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Optimization of LoRaWAN transmitter final stage
Hrbek, Tomáš ; Prokeš, Aleš (referee) ; Hanák, Pavel (advisor)
This diploma thesis deals with optimization of transmitter amplifier parameters for LoRaWAN network. The issue of optimization is first based on the conditions of ETSI EN 300 220, which takes into account the eventuality of interference the adjacent channels in the band. The optimizations are designed specifically for the Qorvo RF5110g integrated circuit, so that the amplifier meets the requirements of the above standard at the limit of the maximum allowed output power and also with respect to radio ecology.
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Differential and pseudo-differential filtering circuits
Hrbek, Tomáš ; Bečková, Zuzana (referee) ; Jeřábek, Jan (advisor)
This bachelor thesis deals with analog frequency filters operating in differential and pseudodifferential mode. It is focused on active filters second order that use modern active elements. For specific solution is analyzed the ability to control filter parameters. It also deals with the design of fully differential filters and transformations from non-differential filters. The thesis analyzes three specific filtering solutions with which ideal simulations and simulations using third order models are performed. A printed circuit is constructed for one filter solution, its parameters are measured and compared with simulations.
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Investigation of Ir(Ox)-Ru(Oy) thin-film catalysts for oxygen evolution reaction in proton exchange membrane water electrolyzers
Hrbek, Tomáš ; Kúš, Peter (advisor)
The main focus of this work is the investigation of the anode catalysts for the Proton Exchange Membrane Water Electrolyzers (PEM-WEs). PEM-WEs play a pivotal role in the hydrogen economy concept as they allow water decomposition into oxygen and hydrogen. However, their operation requires expensive noble metal catalysts, i.e., iridium or platinum. This issue has yet to be solved to mass-produce PEM-WEs. Consequently, our main objective is to reduce the amount of iridium on the anode of PEM-WEs. We addressed this objective by two distinct approaches: morphological and chemical. With the morphological approach, plasma etching of the membrane and the magnetron sputtering of CeO2 served to increase the membrane's active surface. Hence we improved the catalysts utilization. With the chemical approach, we focused on the catalyst itself. Thus, we replaced the pure iridium catalyst with a bimetallic iridium- ruthenium one. Therefore, the activity of the catalyst was enhanced while its price got reduced. To explain and describe the catalyst's behavior, we used various electrochemical methods and surface analysis techniques. Finally, we combined both approaches to obtain one active, stable, and low-iridium-loading anode catalyst for PEM-WE.
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Application for an appeal review on the points of law in civil procedure
Hrbek, Tomáš ; Winterová, Alena (advisor) ; Smolík, Petr (referee)
This thesis focuses on the effective regulation of the application for an appeal review reflecting it from the point of its value background, historical development and the relevant case-law. With an intention to point out the necessary backing for the critical assessment of specific elements and the present form of the application for an appeal review in a civil procedure as a whole, the thesis deals with the theoretical basis of the legal remedies in the civil procedure and with the role of the application for an appeal review in their effective regulation. In the thesis, particular attention is paid to the purposes of the application for an appeal review, i.e. to the unification of the case-law and the protection of the rights of an individual in a particular case, as far as to their relation to the legal certainty resulting from the final decisions, which the use of the application for an appeal review undermines. The thesis contains the general conclusions on the relationship between these values and the conclusions on the appropriateness of the regulation of the particular elements of the application for an appeal review, which are connected with these values. A special chapter of this thesis deals with the history of the appeals focusing only on that facts and legal constructs, which are...
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Investigation of Ir(Ox)-Ru(Oy) thin-film catalysts for oxygen evolution reaction in proton exchange membrane water electrolyzers
Hrbek, Tomáš ; Kúš, Peter (advisor) ; Bystroň, Tomáš (referee)
The main focus of this master thesis is the investigation of the anode catalysts for the Proton Exchange Membrane Water Electrolyzers (PEM-WEs). PEM-WEs play a pivotal role in the hydrogen economy concept as they allow water decomposition into oxygen and hydrogen. However, their operation requires expensive noble metal catalysts, i.e., iridium or platinum. This issue has yet to be solved to mass-produce PEM-WEs. Consequently, our main objective is to reduce the amount of iridium on the anode of PEM-WEs. We addressed this objective by two distinct approaches: morphological and chemical. With the morphological approach, plasma etching of the membrane and the magnetron sput- tering of CeO2 served to increase the membrane's active surface. Hence we improved the catalysts utilization. With the chemical approach, we focused on the catalyst itself. Thus, we replaced the pure iridium catalyst with a bimetallic iridium-ruthenium one. Therefore, the activity of the catalyst was enhanced while its price got reduced. To ex- plain and describe the catalyst's behavior, we used various electrochemical methods and surface analysis techniques. Finally, we combined both approaches to obtain one active, stable, and low-iridium-loading anode catalyst for PEM-WE.
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Optimization of LoRaWAN transmitter final stage
Hrbek, Tomáš ; Prokeš, Aleš (referee) ; Hanák, Pavel (advisor)
This diploma thesis deals with optimization of transmitter amplifier parameters for LoRaWAN network. The issue of optimization is first based on the conditions of ETSI EN 300 220, which takes into account the eventuality of interference the adjacent channels in the band. The optimizations are designed specifically for the Qorvo RF5110g integrated circuit, so that the amplifier meets the requirements of the above standard at the limit of the maximum allowed output power and also with respect to radio ecology.
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Study of the effect of thin film catalyst morphology on efficiency of water electrolyzer with proton conducting membrane
Hrbek, Tomáš ; Matolín, Vladimír (advisor) ; Nováková, Jaroslava (referee)
Title: Study of the effect of thin film catalyst morphology on efficiency of water electrolyzer with proton conducting membrane Author: Tomáš Hrbek Department: Department of Surface and Plasma Science Supervisor: prof. RNDr. Vladimír Matolín, DrSc., Department of Surface and Plasma Science Abstract: This bachelor thesis deals with the possibility of reducing the amount of noble metals in catalytic layers of proton exchange water electrolyzer (PEM-WE). The PEM-WE is an important unit of hydrogen economy as it allows storage of excess energy from renewable sources in the form of chemical energy. In the first part, etched membrane electrolyzers were prepared and tested, membrane etching is a previously unpublished procedure leading to a reduction of the amount of catalyst. Etched membranes were studied by scanning electron microscopy and, consequently tested in real working conditions in electrolyzers. In the second part of the work; Ir and IrO2 were compared as catalysts for PEM-WE anode. Their in-cell performance was tested directly in the electrolysers and in controlled condition by rotating disk electrode. Keywords: electrolyzer, magnetron sputtering, thin-layer catalyst, etched mem- brane PEM, Ir vs. IrO2
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Differential and pseudo-differential filtering circuits
Hrbek, Tomáš ; Bečková, Zuzana (referee) ; Jeřábek, Jan (advisor)
This bachelor thesis deals with analog frequency filters operating in differential and pseudodifferential mode. It is focused on active filters second order that use modern active elements. For specific solution is analyzed the ability to control filter parameters. It also deals with the design of fully differential filters and transformations from non-differential filters. The thesis analyzes three specific filtering solutions with which ideal simulations and simulations using third order models are performed. A printed circuit is constructed for one filter solution, its parameters are measured and compared with simulations.
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Application for an appeal review on the points of law in civil procedure
Hrbek, Tomáš ; Winterová, Alena (advisor) ; Smolík, Petr (referee)
This thesis focuses on the effective regulation of the application for an appeal review reflecting it from the point of its value background, historical development and the relevant case-law. With an intention to point out the necessary backing for the critical assessment of specific elements and the present form of the application for an appeal review in a civil procedure as a whole, the thesis deals with the theoretical basis of the legal remedies in the civil procedure and with the role of the application for an appeal review in their effective regulation. In the thesis, particular attention is paid to the purposes of the application for an appeal review, i.e. to the unification of the case-law and the protection of the rights of an individual in a particular case, as far as to their relation to the legal certainty resulting from the final decisions, which the use of the application for an appeal review undermines. The thesis contains the general conclusions on the relationship between these values and the conclusions on the appropriateness of the regulation of the particular elements of the application for an appeal review, which are connected with these values. A special chapter of this thesis deals with the history of the appeals focusing only on that facts and legal constructs, which are...
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