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Electrical properties analysis of epoxy resins with various fillers
Horák, Luděk ; Kazelle, Jiří (referee) ; Frk, Martin (advisor)
Presented bachelor thesis is focused on studying electroinsulating epoxy resin-based sealings. It describes the chemical composition, production, properties and measuring methods of basic electric quantities of these materials. This work also embodies a preparation of composite epoxy resin samples with different kinds of micro-ground siliceous sand as a filling. The samples given are measured on the temperature dependency of relative permitivity, dissipation factor and inner resistivity.
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Additives effect on electrical properties of the epoxy resins
Šebesta, Petr ; Kazelle, Jiří (referee) ; Frk, Martin (advisor)
Work was carried out in collaboration with SYNPO, Inc. Pardubice, which provided samples resins with various additives for measurement. The work is divided into three theoretical and one practical chapters. The first chapter focuses on dielectrics in general. It deals with their properties and storyline running in them. The second chapter discusses epoxy resins, their formulation, production and application in manufacturing. The third chapter offers a view of the measurement methods used for diagnosing electrical dielectrics. The practical part describes the preparation of samples and their composition, and consequently their measurement with the evaluation of measurement data.
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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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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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Application possibilities of refractometer for liquids diagnostics
Macháč, Milan ; Kazelle, Jiří (referee) ; Frk, Martin (advisor)
This bachelor thesis focuses on application possibilities of refractometer for liquids diagnostics. The first part of the thesis focuses on the theoretical basics propagation of electromagnetic waves. The next section focuses on the measurement of refractive index, refractometry, a description of each type refractometers and short introduction to interferometry. The penultimate chapter is devoted to an application using a refractometer and what can measure and calculate. The last chapter is a practical part, there is described a calibration process, the measured values of the refractive index of liquids and evaluate the results.
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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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Solder Joint Reliability Prediction
Stejskal, Petr ; Skočil, Vlastimil (referee) ; Hovorka, Ladislav (referee) ; Kazelle, Jiří (advisor)
The thesis deals issue of the solder joint reliability and diagnostics. The manufacturing technology of electronics currently features a very high level of perfection. A large number of electrical devices ends its functional life due to solder joint failure. The objective of presented research consists studies of processes taking place in the solder joint due to soldering and after soldering. To this end, I will employ several methods of diagnostics. Noise based methods of solder joint measurement was evaluated. Based on a detailed study and understanding of processes it can be solder joint reliability predicted.
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Study of Metal Oxides and Hydroxides in Aqueous Solutions
Špičák, Petr ; Trnková, Libuše (referee) ; Kadlec, Jaromír (referee) ; Kazelle, Jiří (advisor)
This dissertation work deals with analysis of nickel hydroxide phases, their oxidation compounds, their stability and degradation mechanisms of electrochemically more active alpha phase on standard beta phase. The active material was prepared by both methods, electrodeposition and chemical precipitation. Main analysis method was Electrochemical Quartz Crystal Microbalance in combination with common analytical methods (cyclic voltammetry, potenciometry) can resolute between alpha and beta phases and quantitatively describe differences in main reaction by monitoring mass changes in the active material. Poor stability of the ?-Ni(OH)2 were improved by adding cations with valence two three and four into the structure instead of Ni atoms. The most important role plays cobalt and its hydroxide. Totally new way is to use titanium in combination with other cations. In electrolyte the most significant addition is LiOH, which has beneficial influent on cycle ability, stability in strong alkaline medium and cycle life.
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Study of Electrochemical Insertion Cations to the Oxides of Transitive Metals
Svoboda, Vít ; Kadlec, Jaromír (referee) ; Trnková, Libuše (referee) ; Kazelle, Jiří (advisor)
Electrochromic devices are based on the intercalation processes to the active layer mostly WO3. The optical properties of active layer are changed by intercalation ions from the electrolyte. For that purpose are used Li ions. The mass of thin layer can be observed by the QCM method. This method is based on the changes of the resonance frequency of a quartz crystal resonator. The investigated substance is deposited on the surface of the resonator. Various metals (Pt, Au, Ag) and their compounds should be plated on the resonator. Most frequently, the resonators for the frequency 5,0 MHz are used. This frequency change is used for the detection of chemical changes of the electrode surface and is very sensitive.
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Measurment of Equivalent Circuit of Piezoelectric Resonator
Vomočil, Vojtěch ; Frk, Martin (referee) ; Kazelle, Jiří (advisor)
This theis deals with the general overview of the piezoelectric theory, focused both on the mathematical description and on the attributes of piezoelectric materials. It further focuses on the description of piezoelectric resonators with a more detailed explantation of their equivalent scheme and measurement methods of its single elements. The practical part of the thesis rests on the proposal of a measurement apparatus which will serve to measuring the equivalent circuit piezoelectric resonator elements. The realization of the apparatus and its functionality testing are described. In the experimental part of the thesis, the measured rates are processed and levels of the electric equivalent circuit elements of the used piesoelectric resonator for the basic and the two higher closest resonance frequency are set. The measured results are compiled into a standard measurement protocol. This thesis should place basics to the growing laboratory. It should also be a source of necessary theoretical and practical information for this lab.
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