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Roughness measurement with laser profilometry
Mach, Radoslav ; Frk, Martin (referee) ; Hejátková, Edita (advisor)
The bachelor thesis deals with technology of laser profilometry for material roughness measurements purposes. The theoretical part deals with all aspects of the issue in an effective way and highlights the essential characteristics of used components and material roughness. The focus of this work is in first step to describe the external factors affecting the visual image processing such as increasing of environment temperature and its effect for a camera sensors. And particularly the relationship between CMOS and CCD technologies. The second step is for measuring roughness parameters of materials, such as metal, wood, rubber and plastic with three different lasers. Results demonstrate correlation between the wavelengths of the used laser lights with particular materials.
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Calibration of contact and non-contact thermometers
Skalický, David ; Kazelle, Jiří (referee) ; Frk, Martin (advisor)
This work deals with the calibration of contact and contactless thermometers. The theoretical part describes physical laws, which are important for contact and contactless measuring of temperature, requirements for thermometers, suitability of use different types of thermometers and materials used for construction of temperature sensors. The following part describes metrology with the focus on metrology system of the Czech Republic. This thesis also describes errors and uncertainties of measurments, especially on their division, sources of uncertainties and methodology of type A and type B uncertainty determination. The practical part is focused on the calibration of thermometers within the Czech Metrological Institute and the Faculty of Electrical Engineering and Communication in Brno.
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Nanocomposite varnishes
Hlavčo, Tomáš ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This work deals with issues of nanoparts and nanotechnology and it’s applications in the sphere of dielectrics. Primary objective has been to make series of varnish samples filled with nanoparts. Then we have measured dependencies of absorber and resorber currents and we have been monitoring changes of dielectric properties against unfulfilled samples. Used materials were epoxy resin TSA 220S filled with nanoparts of silicon oxide.
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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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Analysis of the rheological properties of vegetable oils and their components
Divílek, Petr ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This Master’s thesis is dealing with theoretical analysis of vegetable, mineral oils and synthetic fluids, and with measuring of density and viscosity of selected samples of electric insulating fluids. The main part of the thesis is focused on vegetable oils and their elements called fatty acids. Those are more detail described in separate capitols. In those capitols is described their utilization in engineering practice with focus on energetics, where vegetable oils are used in larger scale. In experimental part of the work is measurement of density and dynamic viscosity. Viscosity was measured on two different machines, first the Hoppler viscometer and on vibrating viscometer. Results of these measurement are evaluated in tables and graphs.
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Thermal degradation of alternative electrical insulating liquids
Vodička, Tomáš ; Kazelle, Jiří (referee) ; Frk, Martin (advisor)
This thesis deals with alternative thermal degradation of electrical insulating liquids. The theoretical part describes the current state of the problem, electrical insulating liquids, their classification and types. There are described properties of electrical insulating liquids, their models of aging and diagnostic methods in accordance with the appropriate standards. In the practical part are chosen by representatives of alternative electrical insulating liquids and there are determined their dielectric characteristics in the initial state. According to the measured values is chosen five candidates for which it is designed and implemented an accelerated degradation test. During the test are measured dielectric parameters of the selected oils. Measured dependencies are mathematically approximated. In conclusion, the results are compared and physically interpreted in view of oxidation stability.
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Determination of material volume expansion
Silvestr, Jiří ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This Bachelor’s thesis deals with the temperature dependence of the density of solid and liquid materials. First of all I measured the density of solid and liquid materials, from which I made an overview. In the next section I focused on application of volumetric and length expansion in practice and made a table of densities of materials and their appropriate temperature coefficients of volumetric or length expansion. Last section focuses on the practical measurement with one of the methods and their automation.
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Dielectric properties of thermally aged slot insulations
Přikryl, Tomáš ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
Bachelor's thesis monitor changes in the basic properties of dielectric isolation on the basis of polyester film during the humidity changes. The samples of material were measured time according rechargeable inab and dischargable ivyb currents in humidities 0 %, 33 %, 75 %, 95 % and ambient temperature. Further work is monitored by the time dependence of internal rezistivity depending on the time of ageing and relative humidity. The subject of experiments is material ISONOM NKN 2039 companie ISOVOLTA Elektroisolierstaffe.
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Properties of aprotic electrolytes for lithium-ion accumulators
Staněk, Vladimír ; Máca, Josef (referee) ; Frk, Martin (advisor)
The present work deals with the properties of suitable electrolytes for lithium-ion batteries. The first part described in the current issue of electrolytes for lithium-ion batteries, types of solvents and their properties and methods of measurement properties. The second part is devoted to the measurement of the properties of solvents and electrolytes such as relative permittivity, density and viscosity. Measurement of relative permittivity was focused on the measurement of the solvent mixture with varying the percentage of the solvent. Viscosity and density were measured on a solvent with a lithium salt added (final electrolyte).
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