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Antennas for energy transmission along the car roof
Škoda, Adam ; Hebelka, Vladimír (referee) ; Vélim, Jan (advisor)
The presented master’s thesis deals with antennas transmitting energy along conductive materials. Surface waves are used for energy transmission. According to its properties, the horn antenna was chosen for the problem solution. This thesis includes the theoretical analysis of surface waves, waveguides and horn antennas. The concept of antennas includes the comparison of two different materials and two different frequencies. From the set of 8GHz antennas, the structure of two antennas where one wearing the other was chosen as the most suitable. The FoamClad material was also selected due to achievement of better parameters and properties then material CuClad. This structure was designed by two identical horn antennas where the energy between them is transmitted via slot. The suitable feeding and parallel plates were designed, and further the current structure was modified to SIW structure. The designed antenna was manufactured and its properties were measured for further comparison with simulation results. Furthermore, achieved differences between simulated and real antenna are discussed.
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Modelling of a heat water exchanger and its regulation
Černík, Michal ; Kaczmarczyk, Václav (referee) ; Mihálik, Ondrej (advisor)
The thesis deals with the modelling of a hot water heat exchanger station and its control. It includes project documentation, with theoretical and practical part. The theoretical part is dealing with theoretical knowledge about every used element that is used in the design. The practical part deals with the implementation of the electrical wiring of the station, its connection with the control automaton, design of the mathematical model, simulation and design of the controller.
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Photogeneration of Charge Carriers in Organic Semiconductors
Heinrichová, Patricie ; Kratochvílová, Irena (referee) ; Cimrová,, Věra (referee) ; Weiter, Martin (advisor)
The interest in the detail knowledge about elementary electronic processes during photogeneration of charge carriers, which allow achieving higher efficiency of organic solar cells, grows with advent of the commercial organic solar cells production. The thesis is focused on study of photogeneration of charge carriers in organic semiconductors, especially in -conjugated polymer materials. First part of the thesis summarized state of the art in studies of photogeneration of charge carriers in polymer solar cells. Subsequent experimental and results part are focused on study of polymeric solar cells prepared from electron donor polymers MDMO-PPV, Tg-PPV, PCDTBT and PCBTDPP and electron acceptor derivates of fullerenes PC60BM and PC70BM. Results of the thesis are divided in tree main parts: 1) study of charge transfer between electron donor and electron acceptor materials by optical methods, 2) study of charge transfer between electron donor and electron acceptor materials by optoelectrical methods and 3) development of organic solar cells on flexible substrates. The last part is focused largely on deposition methods of active materials thin layer.
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Kinetics of photochromic reactions in thin polymeric layers
Zeman, Vojtěch ; Weiter, Martin (referee) ; Vala, Martin (advisor)
The thesis is aimed to the study of spiropyrane behavior in polymeric matrix of poly(N-vinylkarbazole) (PVK) and poly[2-methoxy-5-(3´,7´-dimethyloctyloxy)-1,4-fenylenvinylene)] (MDMO-PPV). The photochromic transformation of spiropyrane to its isomeric merocyanine form (SPMC) was studied by absorption and emission spectroscopy. It was found, that photochromic reaction is markedly dependent on the environment. In the PVK polymer, which don’t absorb in the visible region, a high yield of photochromic reaction was achieved. Both, absorption and emission spectrums were observed for this system. From the measurement of time dependencies of the fotochromic reaction, the activation energy of the reverse reaction was determined. A different behavior, particularly in emissive spectrums, was found for the MDMO-PPV polymer doped with spiropyrane. Instead of formation of new band of merocyanine, decrease of the polymer fluorescence was observed. Subsequently, we studied the interaction between the polymeric matrix and the photochromic spiropyrane using fluorescence quenching method. On the basis of energy transfer theory, a critical radius of the fluorescence quenching sphere in solution and in solid was determined.
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In-car wireless power transfer
Cupal, Miroslav ; Polívka, Milan (referee) ; Raida, Zbyněk (advisor)
The thesis is focused on the design of antennas for wireless power transfer inside a car near the frequency of 8 GHz. In the last century, a number of scientists dealt with wireless transmission of energy with high power and long distances. Currently, attention is given to methods capable of transmitting energy with good effectively over a distance of meters for charging mobile devices, wireless sensors and other devices with low power consumption.
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Effect of EU doping on the optical properties of ZnO nanorods prepared by chemical bath deposition
Yatskiv, Roman ; Bašinová, Nikola ; Grym, Jan ; Vaniš, Jan
We report on the properties of Eu-doped ZnO nanorods prepared by chemical bath deposition from aqueous solutions in an autoclave. The autoclave enables to grow the nanorods above the boiling point of water. The nanorods were characterized by scanning electron microscopy, secondary ion mass spectroscopy, and low temperature photoluminescence spectroscopy. Under the UV light excitation, the nanorods show a strong blue emission at 450 nm, which is associated with the 4f(6)5d - 4f(4) transitions of Eu2+ ions. We discuss the mechanisms responsible for the blue luminescence. We further clarify how the growth parameters affect the morphology and the optical properties of the nanorods. Growth temperatures above the boiling point of water significantly influence the intensity ratio of the near band edge emission to the deep level emission and greatly enhance optical quality of the nanorods.
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Analysis of powertrain systems of drilling equipment
Klíč, Zdeněk ; Pokorný, Přemysl (referee) ; Mergl, Václav (advisor)
This bachelor's thesis deals with powertrain systems of drilling rigs intended for construction work. The powertrain systems are divided according to the energy they used and then analyzed. This analysis includes a description of the important components in the systems, schematic images indicating the principle, a description of operations, power transfer, and specific examples of machines using each of the systems. The next part focuses on a summary of the pros and cons. The knowledge gained relates to modern drilling rigs with an emphasis on environmental friendliness. The result of the work is the generalization of this issue and the disclosure of a more detailed solution for individual systems.
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Organic luminophores with long wavelenght emission
Kolaříková, Adéla ; Kratochvíl, Matouš (referee) ; Vala, Martin (advisor)
This bachelor thesis studies the possibility of achieving intense fluorescence in the red region of the spectrum using Förster resonance energy transfer (FRET) in nanoparticles. First, the optical properties of organic molecules that could be suitable for the creation of a so-called host-guest (HG) system consisting of an acceptor-donor pair were studied. The molecules studied were based on derivatives of diphenylstilbene containing the electron-donor group diphenylamine (DPA-DPS), which is linked to a differing electron-acceptor group via a -conjugated double bond system. The acceptor groups used, i.e., indandione (-IOO), vinyl ( V) and di(methoxycarbonyl)vinyl (-V(COOMe)2), differ from each other in structure and polarity, which was reflected by a change in the position of the fluorescence spectrum. In the HG systems studied, DPA-DPS-IOO always served as the guest (G1) and DPA-DPS-V and DPA-DPS-V(COOMe)2 always served as the host (H1 or H2). Nanoparticles from these substances (G1H1 and G1H2) were prepared by the nanoprecipitation method. FRET was observed for both of these systems. Upon excitation of the matrix, the energy was transferred to the guest G1, which subsequently fluoresced in the long-wavelength region. Furthermore, an increase in the quantum yield of the guest fluorescence was also observed for the nanoparticles formed from the G1H2 system, from 7% (powder) and 3.1% (nanoparticles) to 14% compared to both the powder form and nanoparticles formed from the guest alone. No increase in the quantum yield of guest fluorescence was observed for the nanoparticles of the G1H1 system. The results indicated that FRET can be an effective tool in developing nanoparticles exhibiting intense long-wavelength fluorescence for imaging.
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Heat Exchanger Regulation
Černík, M. ; Mihálik, O.
The work deals with the design of a laboratory task including model of heat exchanger station. It includes project documentation, with theoretical and practical part. The theoretical part is concerned with theoretical knowledge about every element used in the design. Practical part deals with the control unit of the station and the simulation of heat exchanger.
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