|
|
Degradation of epoxy resins vith various aditives by solar radiation
Škarabelová, Lenka ; Novák, Vítězslav (referee) ; Kazelle, Jiří (advisor)
This master’s thesis is focused on the study of chemical and physical properties of dielectric materials with main focus on epoxy resins. It includes possible processes that can influence the properties of epoxy resins, both processes that improve polymer properties and processes that cause material degradation. Next part of the thesis is a description of diagnostic methods suitable for measurement of basic electrical quantities of material and design of a suitable method for measuring properties of epoxy resins with different additives, influencing the samples by solar radiation. At the end, the work includes an experiment dedicated to the degradation of epoxy resins with various additives by solar radiation and the evaluation of the experiment.
|
|
| |
|
|
Comparation of the properties of the perovskit photovoltaic cells
Mudroch, Michal ; Kazelle, Jiří (referee) ; Novák, Vítězslav (advisor)
In this bachelor’s thesis it is introduced production technology and conversion of electromagnetic radiation into electric energy employing perovskites. In this paper are also described known types of perovskite photovoltaic cell structures and materials that are used to produce them. Furthermore, the theoretical part describes properties of perovskite photovoltaic cells, measured electric quantities and methods of measurement such as photospectroscopy photoimpedance spectroscopy and impedance spectroscopy that are also used to analyze cells functionality. In the following practical part is described fabrication of perovskite cells and evaluation of measured results of the perovskite cell.
|
|
|
Cooling of Two-channel audio power-amplifier using FVM
Němec, Radek ; Kazelle, Jiří (referee) ; Vyroubal, Petr (advisor)
This bachelor´s thesis is dealing with the design and construction of two-channel audio Leach type power-amplifier, including the necessary additional components and subsequent design of the amplifier cooling using Flow Simulation tool included in the SolidWorks design system. The opening chapters is about theoretical analysis of audio amplifiers, heat transfer and description of SolidWorks design system. The main part of this thesis contains the design and construction of amplifier and design of each variants of amplifier cooling, including the best variation designed. The last part of the thesis is about assembling the amplifier and evaluation of economic aspects of its production.
|
|
|
Drying and preheating in potting process of epoxides
Matoušová, Klára ; Novák, Vítězslav (referee) ; Kazelle, Jiří (advisor)
The bachelor's thesis is dealing with the defects in epoxy resin flooded transformer devices. Since these can be damaged severely in terms of quality by numerous forces, the main focus is dedicated to the impact of moisture. The thesis describes the manufacturing technology including the methods applied and materials used. It further encompasses the composition of epoxy resin and the mechanisms used for their hardening processes. Additionally, the description of the moisture, the impact of adverse forces and the method of their elimination using drying is presented. In the experimental part of the paper, a moisture of the banding materials was measured. On the basis of the results acquired, the paper reaches a conclusion on the ideal time frame of drying, the sufficiency of materials in terms of drying and in two cases two substitutes for contemporary uneasily dryable samples were considered.
|
|
|
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.
|
|
|
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.
|
|
|
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.
|
|
|
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.
|
|
|
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.
|
guest ::
