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Ultrasound in material diagnostics
Kristek, Michal ; Frk, Martin (referee) ; Kazelle, Jiří (advisor)
Objectives of the semestral project are to study the physical basis of ultra acoustic and comprehend the basics of ultrasound usage in diagnostic of materials. I should also become familiar with functions and usage of ultrasound device EPOCH LT made by OLYMPUS and perform measurement of thickness and speed of ultrasound spreading in selected materials.
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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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Optimisation of the house heating by use of the renewable energy sources
Husák, Ondřej ; Frk, Martin (referee) ; Křivík, Petr (advisor)
The thesis contains is familiar with the issues of renewable energy and global warming. Assessing the use of these resources in households in the Czech Republic. The selected family house, perform measurements on the existing heating system. In conclusion, there is suggestions for optimalization system houses, the possibility of linking the with renewable energy sources and an assessment of economic turn.
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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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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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Piezoelectricity in technical practice
Škarabelová, Lenka ; Frk, Martin (referee) ; Kazelle, Jiří (advisor)
Bachelor's thesis is dedicated to the study of the principle and possibilities of use of the piezoelectric effect. Since the use of piezoelectric effect in electrical engineering is very extensive, the main focus is placed on the ability to exploit this effect in the field of ultrasonic and piezoelectric resonators. Next aim of this work is practically and theoretically to get acquainted with the measurement of small changes in weight, using electrochemical quartz crystal microbalance (EQCM), also with an ultrasonic equipment from company Olympus and ultrasonic defectoscopy for detection of possible imperfections in the material and their evaluation.
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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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