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Analysis of the properties of liquid crystalline materials
Bodeček, Martin ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
Master´s thesis covers introduction to the problems of materials with specific proprieties named liquid crystals. Theoretic part features primary fission these materials, theirs mechanical, electrotechnical and optical characteristics. Interesting chapter is description choice application including perhaps most interesting using liquid crystals - liquid crystal display. In this trend continues experimental part too, where there are first mentioned characteristics LCD, and after it alone metering capacitive characteristics display with active matrix. Main attention in experiment is however concentraded on evaluation frequency analysis of components complex permittivity regarding in plant temperature on submitted sample liquid crystals.
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Computer modelling of courses of complex permittivity
Frybert, Jan ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
The aim of this work was to create the program for modelling of frequencies courses of complex permittivity parts according to the basic empirical functions, which are described distribution of relaxation time. The main attention is concentrated on the influence of particular parameters on the courses of real and imaginary parts of complex permittivity. Whole program is written in Borland Builder C++.
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Effects of climatic conditions on the properties of butadiene oligomers
Baťa, David ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
The bachelor thesis is conversant of monitoring dielectric material properties in AC electric field. The electrical properties of variety liquid oligobutadiens includes are studying in their practical applications. Experimentally there are verified and analyzed influences of the climatic factors especially temperature and ultraviolet radiation on the frequency dependencies of complex permittivity parts with respect to present various functional groups in oligobutadiene chains.
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Dielectric properties of liquid insulators
Jahn, Michal ; Starý, Jiří (referee) ; Špinka, Jiří (advisor)
This master‘s thesis deals with measurement of liquid dielectric materials (insulators). Above all, it is the different kinds of clean and drinking water, but also transformer oils. There was done theoretical information retrieval about the given topic in this project and on the basis of theory there were realized the relevant measurements of selected properties of liquid dielectric, such as permittivity, capacitance, loss number, conductivity, but also temperature dependence of these parameters. The measurements were realized with the help of product manufactured at the faculty FEKT VUT and with the help of measuring system AGILENT 16452A. The measured results were evaluated, graphically processed and compared.
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Influence of curing parameters on the properties of insulating varnishes
Paščinský, Jiří ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
The bachelor thesis submitted deals with properties of electro-insulating lacquer hardenable by ultraviolent radiation and temperature. Within the theoretical part a summary of electro-insulating lacquers used in electrotechnics has been elaborated. Chemical changes that take place in this material group have been described during hardening process. A method of dielectric relaxation spectroscopy specifically focused on mathematic and physical description of polarisation and conductive mechanisms taking place in the structure of the given material has been closely studied. In the experimental part a workplace for hardening and long-term exposition of lacquered samples during simultaneous effect of various climatic elements has been designed and built. The selected electric and mechanical properties have been monitored on three sets of experimental samples prepared by means of different methodical procedures. The results gained have been mathematically evaluated and physically interpreted in term of methodical procedure of hardening and different temperature of measurement.
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