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Minimizing the effect of interference on wireless network
Doležal, Jan ; Kyselák, Martin (referee) ; Škorpil, Vladislav (advisor)
This thesis is concerned the technology with technologies of transfer through wireless devices. It is about possibilities of optimization of transfer in wireless net, especially of the reduction of interference influence. The first part is about theory and the standards development of wireless technology. There are methods and principles used in wireless technologies. The second part is a practical measuring and testing of an internal wireless net, with the emphasis being on the source of interference influence. Measuring was focused on interference between access points and was not about meteorological influence. It continues with theory and testing of interference of the microwave oven in our wireless net. Then, it is a practical demonstration of interference in an external environment. There are practical examples of interference between different providers’ nets on the same area and solutions to prevent or to cancel this interference. In next part of work the wireless net is parsed and described in a given territory. Here is described the way how to precede the reciprocal interference and eventually how this mutual disturbance suppress. Consequently, our net is optimized for customer growth and for today’s options of newer and more powerful components for wireless transfer. Finally there are two laboratory tasks. The first one is about practical measuring and testing of wireless net’s parameters and the second one is about simulation of wireless networks in the Opnet program.
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Photocatalytic properties of hybrid titania-silica layers
Zbořilová, Zdeňka ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
This diploma thesis is focused on the preparation of hybrid titania-silica layers. Titanium tetraisopropoxide and tetraethyl orthosilicate with Levasil were used as the precursors for TiO2 and SiO2 synthesis, respectively. The layers were deposited on substrates by material printing. Furthermore, this work is focused on study of the photocatalytic activity of prepared titania/silica hybrid layers. Photocatalytic activity of prepared layers was studied by measuring the oxidation of 2,6-dichlorindofenolu, oxidative degradation of stearic acid and oxidation of terephthalic acid. The influence of hybrid layers number on the photocatalytic activity was investigated.
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Photocatalytic activity of titania multilayer printed structures
Potočková, Lucie ; Pekárková, Jana (referee) ; Dzik, Petr (advisor)
This thesis deals with the preparation of titanium dioxide films by the sol-gel process. Films were deposited by material printing on soda-lime glass plates. The thickness of layers was directed by repeated printing. Thus were prepared multi-layered TiO2 coatings. The surface topology of films was investigated by optical microscopy and scanning electron microscopy. The photocatalytic activity of these coatings was studied on a model compound 2,6-dichlorineindophenol. The influence of the number of TiO2 layers and the intensity of UV irradiation on the size of 2,6-dichlorineindophenol degradation rate constant was monitored. The photo-induced hydrophilic properties of prepared coatings were studied as well.
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Synthesis and study of fluorinated organic materials for electronic and optoelectronic applications
Halaksa, Roman ; Pospíšilík, Karel (referee) ; Krajčovič, Jozef (advisor)
This essay deals with polyfluorinated aromatic compounds, as a strong electronacceptor units and with its incorporation into advanced monomeric and oligomeric systems. It deals with theoretical aspects of structure of mentioned building units, which shove, that it could be really progressive. Also examples of so far synthesized molecules, that can be found in literature, are included. The second part of essay deals with synthesis of main intermediates via Kumada cross-coupling and with synthesis of tetrafluorophenylene bridged thiophene trimmers via Stille cross-coupling.
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Monitoring of photocatalytic activity using redox dyes
Uhrová, Ivana ; Drbohlavová, Jana (referee) ; Veselý, Michal (advisor)
The bachelor thesis deals with assessment of photocatalytic activity of titanium dioxide. The easiest and simultaneously the quickest way is bleaching of indicator ink based on redox dye. The theoretical part contains characteristics of several similar dyes and a description of ink-structure effect on total bleaching speed. The experimental part elaborately describes bleaching of indicator ink based on redox dye 2,6 dichloroindophenol, depending on the number of ink layers on photocatalytic active surface as well as on total amount of glycerol.
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Monitoring of photocatalytic activity
Jurášek, Martin ; Drbohlavová, Jana (referee) ; Veselý, Michal (advisor)
Bachelors thesis deals with kinetics of redox dye 2,6-dichloroindophenol degradation. Thanks to photo-reduced form is colourless, it’s suitable to use it for photocatalytic activity rapid assessment of the thin titanium dioxide layers. The thin layers of TiO2 were prepared using nano-crystalline titanium dioxide suspension with amorphous silica. These layers, including layers of redox dye, were deposited by material printing process. The rate of redox dye photo-reduction was monitored in dependence of number of thin titanium dioxide layers at different UV irradiance. Redox dye concentration was studied using UV-VIS spectroscopy.
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Administrative and storage building in Kunratice, implementation of carcass substructure
Herůfek, Marek ; Liška, Pavel (referee) ; Kovářová, Barbora (advisor)
Content of bachelor work is civil-technological project of substructure in administrative and storage object in Kunratice close to Praha. Project contains technological prescriptions of drilled piles, groundwork and lime stabilisation. Another parts are inspection and testing plans, situation of building with wide detentions of transport routes, bill of quantities, schedule of work, catalog of mechanization, safety during work and organization of construction.
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