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Analysis of operating fluids properties
Chrobák, Jan ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This diploma thesis is focused on introducing the mathematical and physical fundamentals of viskosity, density and refractive index of liquids and methods of its measurement. Based on available literatures specify review of areas in which the measurement of dynamic viscosity is used for evaluation the actual state of liquid materials. Discuss the possibility of using for example variables to determine the concentration of fat in milk and ethanol in alcoholic beverages. The sample of liquid to realize the practical measurements.
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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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Ferroelectrics in an electric field
Pavelka, Petr ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
The submitted thesis describes characteristics and use of ferroelectric materials which find their utilization in electrotechnical and electronics industry. The thesis is mainly aimed at their behaviour in the electrical field at various intensity. The method using an osciloscope is selected for measuring. For the main measuring in part of this thesis was produced experimental wafer with five samples which were subsequently mesuared. The VEE PRO program was used for creating of collecting datas for histeresis loop and it’s functionality was checked on wafer with five examples in measuring. During this measuring was also measured electric tension dependence of components of complex permittivity.
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Effects of electrical stress on properties of electrical insulating materials
Hangya, Josef ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
Diploma thesis treat of effect of direct, alternate and pulse electrical stress on the properties surveyed electrical insulating material. Object of this experiment is crystalline high-density polystyrene QUINN PS. To monitor the stress is used the method of dielectric relaxation spectroscopy. Under examinations are the resultant dielectric spectra, which constitute the frequency dependencies of components of complex permitivity. Samples of the selected material are exposed to effects of alternate and pulse electrical stress on the different intensities of the electric field. In the direct field are then monitored absorption characteristics and specific volume resistance of the samples.
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Impact of the climatic conditions upon the varnishes properties
Mikoláš, Jiří ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
This bachelor's project analysis influence of moisture absorption on dielectric properties of composite material, which was exposured various relative humidity. The composite material consist of epoxide varnish EPOXYLITE TSA 220S by company Epoxylite Ltd. with various weight percentage number micro-ground mica. This experiment was carried out by dielectric relaxation spectroscopy with frequency range from 100 Hz to 1 MHz. Elementary results of this project are composite material frequency dependencies of component part of complex permittivity.
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Thermal aging of nanocomposites
Janíček, Martin ; Rozsívalová, Zdenka (referee) ; Polsterová, Helena (advisor)
This thesis deals with issues of properties of nanocomposites and it´s heat aging. In the first part there are theoretically analysed some of the basic therms connected with nanocomposites. Also there are outlined basic methods of production of these matherials. The most important is specification of individual properties when bigger attention is gived to electrical properties. Practic part deals with heat aging of samples of nanocomposites filled with nanoparticles Al2O3. There was monitored impact of time of aging on values of internal resistance, dissipation factor and relative permitivity.
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Uncertainties of measurements of temperature
Staněk, Vladimír ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This work deals with various methods of temperature measurement and uncertainties of the measurements. The work is well-arranged the principles of temperature sensors. Under each of these sensors is this work subsequently divided into chapters, such as metal resistance, resistance semiconductor, monolithic PN, thermoelectric, expansion, special, and proximity sensors indicating temperatures. The next chapter also describes the calculation of the direct measurement uncertainties and practical example is shown in the measurement of temperatures in which the counting uncertainty.
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Determination of moisture content in electrical insulating materials
Šebesta, Petr ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This work is based on determination of moisture content in electrical insulating materials materials and ways to measure the moisture. In the theoretical section describes the methods of thermal analysis, and subsequently described in detail Thermogravimetry method, which is used in the measurement. Measurements are made using the Moisture Analyzer RADWAG 60 W/H connected with a PC, using a variety of samples from inorganic to organic. A great variety of samples was chosen because of demonstrations thermogravimetric methods and a better understanding of wetting and drying of different materials.
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Methodology for contactless measurement of temperature
Skalický, David ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This thesis deals with the issues of contactless measuring of temperatures and calibration of chosen temperature meter. The beginning of this thesis concerns physical laws and basic terms which are crucial for contactless measuring of temperatures. The following part gives the division of detectors and pyrometres for contactless measuring of temperatures. The conclusion of the theoretical part describes the advantages of these ways of measuring and practical use of them. The practical part deals with instruments that are accessible at Faculty of Electrical Engineering and Communication, their comparing and choice of the most advantageous meter for calibration. The following part is the implementation of the experiment related to contactless meassuring of temperatures. The conclusion of the practical part contains composition of optimized workplace for calibration of contactless temperature meters and the calibration of chosen temperature meters itself.
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