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Study of electrical properties of nanocomposites
Ovsík, Jiří ; Rozsívalová, Zdenka (referee) ; Polsterová, Helena (advisor)
The present work deals with the electrical properties of nanocomposite materials. Samples for the experiment are made of epoxy resin as a matrix and oxides TiO2, Al2O3, WO3, SiO2 as nanofillers in 0.5 and 1 percent performance. The experimental samples are measured in temperature and frequency dependence of relative permittivity, dissipation factor, rezistivity and are broken down by the influence of filler on the electrical properties of the polymer. Attention is also paid to the mechanical properties of nanocomposites.
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Measurement of HV equipments by electronic bridge.
Kumičák, Ivan ; Pelikán, Luděk (referee) ; Krbal, Michal (advisor)
The main idea of this thesis is measurements of dielectric materials by using a device Tettex. The thesis is about basic physic properties of dielectric materials. The determination of a dielectric material is considered. The behavior of these materials in electrical fields and reasons, those can have an influence on it, are considered as well. In the text are described measuring methods of chosen parameters of dielectric materials by device Tettex and its functional principles. There are an evaluation of measurements, which were done, and a discussion about achieved results.
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Measurement of dielectric properties of liquid fuels for automotive power units
Redr, Martin ; Čech, Ondřej (referee) ; Chladil, Ladislav (advisor)
This bachelor thesis dealt with measuring of dielectric properties of propellants. The aim of the thesis was to find out differences between dielectric quantities of propellants from various manufacturers and in different proportions of refined to so-called bio-components. The theoretical physical principles of dielectric substances – permittivity and dissipation factor were described. In the thesis the most famous electrical insulation fluids whose dielectric characteristics are similar as propellants were mentioned. Furthermore, the study about dielectric properties of propellants and chosen fuels on the Czech market were mentioned. In the experimental part of the thesis, selected fuel samples at varying frequency and temperature were measured. These results were then evaluated and compared.
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Study of alternative electroinsulating liquids properties
Bannert, Tomáš ; Hylský, Josef (referee) ; Frk, Martin (advisor)
This bachelor´s thesis is dealing with the study of alternative electrical insulating properties of the materials used in the electronics industry, particularly liquids based on natural esters and especially their constituents in the form of higher fatty acids and esters. The work is divided into theoretical and practical part. The theoretical part deals with the characterization of vegetable oils, their constituents and mineral oils, their comparison in terms of electrical and non-electrical properties and current state of the use of vegetable oils and their constituents in the electronics industry. Further it’s dealing with analysis of diagnostic methods for these characteristics. In the experimental part were analyzed electrical and non-electrical properties of selected samples of vegetable oils, their constituents and mineral oils such as the density, the dynamic viscosity and the complex permittivity and its parts as relative permittivity and loss number. Evaluations of the results of each group are compared with each other.
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Mica modified electroinsulating varnishes
Mrkos, Pavel ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
This master´s thesis deals with influence of mica content on the electrical properties of electrical insulating varnishes, particularly in the polyester resin Dolphon XL 2102. It focuses on diagnostic methods and testing the properties of electroinsulating varnishes. Examines the potential benefits of micronised mica in order to achieve better electrical insulation properties of the system compared to the matrix. The composite material consists of polyester resin Dolphon XL 2102, which is modified different mass percentage of micronized mica. The results of this project are frequency dependencies of real and imaginary parts of complex permitivity of varnish component.
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Degradation test of polymer material
Darebný, Tomáš ; Špinka, Jiří (referee) ; Vaněk, Jiří (advisor)
Basic knowledge of photovoltaic energy transformation, devices and materials, used in photovoltaics are summarized in this bachelor’s thesis. Sort of degradation factors of the photovoltaic panels and the norm ČSN EN 61215, are described there. The main purpose of this research is monitoring the change of volume and surface resistivity of selected covering materials. These covering materials were influenced of increased humidity.
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Study of electric properties of composite
Macháček, Miroslav ; Havlíček, Svatopluk (referee) ; Polsterová, Helena (advisor)
This work deals with issues of composite materials. The general aim is to observe how the amout of filling infuence dielectric spectrum which is measured on prepared samples. For this purpose had been created variety of a samples with different percentage of filling with mica. Measured values had been compared with theoretically values, determinated using mixture formulas.
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Preparation of Epoxy Based Insulating Materials Filled by Nanoparticles
Mockovčiak, Kristian ; Čech, Ondřej (referee) ; Chladil, Ladislav (advisor)
The present thesis deals with the preparation of epoxy insulating materials filled with nanoparticles and its electrical properties. Experimental samples are made of epoxy resin as a matrix and titanium dioxide nanoparticles (TiO2) as nanofillers in 0.5, 1 and 3 percent filling. Temperature dependencies of internal resistivity, relative permittivity and loss factor are measured on nanocomposite samples. The influence of the filler on the resulting electrical properties of the polymer used is discussed.
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Influence of the Temperature on the Dielectric properties epoxy with ground mica
Ráček, Tomáš ; Havlíček, Svatopluk (referee) ; Polsterová, Helena (advisor)
The paper is focused on theoretical analysis of the basic characteristics of dielectrics, especially on the examination of these qualities at samples of epoxy sealing compound filled with powder mica, and their dependance on the temperature and the content of filling in the material. The measured quantities are inner resistivity, relative permitivity, and loss factor. The paper also deals with the sensitivity of the material to humidity, and through the influence of humidity to the other measured quantities.
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Study of electric properties of nanocomposites
Libra, Miroslav ; Rozsívalová, Zdenka (referee) ; Polsterová, Helena (advisor)
The present master´s thesis deals with the electrical properties of nanocomposite materials. Samples for the experiment are made epoxi resin and oxides TiO2 and Al2O3 as nanofillers in different percent performace. The samples nanocomposites are measured temperature dependence of the resistivity inside, dissipation factor and relative permittivity. It discusses the effect of the filler on the resulting electrical properties of the polymer.
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