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New gel electrolytes
Sumka, Martin ; Jahn, Michal (referee) ; Sedlaříková, Marie (advisor)
This master´s thesis deals with the properties of gel polymer electrolytes, brief characteristics of other types of electrolytes and materials that are used for preparing polymer electrolytes. The thesis explains the use of the gel electrolytes in practice, the current conduction in the electrolytes and the properties of ionic liquids, and flame retardants. This thesis also focuses on methods of measurement of mechanical properties of gel polymer electrolytes. The practical part is focused on preparation of methacrylate gel electrolytes and their modifications with the use of flame retardant - triethyl phosphate (TEP) and ionic liquid - 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (Emim TFSI). In this part there are evaluations of their potential funcionality (potential window) and specific conductance conductivity using the method LSV (linear sweep voltammetry) and impedance spectroscopy. The practical part also includes a thermal analysis of selected samples by TGA, DTA and EGA methods.
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Simulation of steady-state and dynamic behavior of low-temperature fuel cell
Smugala, Ondrej ; Radil, Lukáš (referee) ; Ptáček, Michal (advisor)
This bachelor´s thesis is concerned with mathematic modelling of low temperature proton exchange membrane fuel cell (PEMFC). First part of the thesis is focused on explaining the principle of production of electricity by this type of source. The main advantages and disadvantages of this technology are presented there. A division of fuel cells according to the stack temperature and the kind of used electrolyte is also made in this part. Typical technical information is mentioned for every type of fuel cell. The rest of thesis is concerned with the PEMFC. Firstly there is a description of construction of fuel cell and a presentation of applications in the industry. The second part of work includes a mathematical description of steady and dynamic behavior of fuel cell which is based on relations among fundamental parameters and quantities. The other part contains all results of simulation which was made on a model created in Matlab Simulink. Comparison of the results of real measurement with the results of simulation which was performed on a modified model is provided in the last part of thesis.
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Testing of Surge Arresters
Jeřábek, Lukáš ; Paar, Martin (referee) ; Krbal, Michal (advisor)
This bachelor's thesis is devoted to metal oxide surge arresters. After historical and theoretical introduction, which explains their principles and describes their characteristical properties, analysis of the standard IEC 60099-4 and testing according to the standard with focus on the type tests follows. This chapter is also amended with review of the standard's imperfections and with its most probable future development. The work concludes with a market survey, a review of the largest manufacturers and a comparison of their products.
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Low ESR meter controlled by the microcontroller
Giemza, Michal ; Adámek, Martin (referee) ; Šteffan, Pavel (advisor)
This thesis describes the design and realization of the equivalent series resistance meter of capacitors. The first part discussed the theoretical issue of the equivalent series resistance of capacitor and chooses an appropriate measuring method. The second part describes the design of functional blocks of the meter and describes the realization of the final meter by the circuit and software page. The last section describes the measurement on real capacitors and its results.
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The influence of iron on nickel accumulator charging
Mičák, Tomáš ; Čech, Ondřej (referee) ; Pléha, David (advisor)
This bachelor's thesis is dealing with a problematics of iron influence on charging of accumulator, more precisely on its cathode. The theory describes comparision of an accumulators at our market, important properties of Ni-Cd accumulators, their function principle, events happening during charge-discharge cycles of Ni-Cd cells and measuring method that will be used to verify of the iron influence. The practical part deals with the influence of iron on the development of oxygen during process of battery charging, on how iron affects the potential shift of oxygen gassing and how temperature affects this event.
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Low temperature fuel cell for ultra-light-plane
Hladiš, Lukáš ; Brázdil, Marian (referee) ; Pospíšil, Jiří (advisor)
This thesis deals with the concept of propulsion for ultralight plane with using fuel cells technology. Here are described the individual kinds of fuel cells and possible fuel. Furthermore it is listed the calculation of low-temperature fuel cell H2 - O2 with polymeric membrane (PEM). The thesis includes also a part with the design drawings of the proposed solutions.
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Progress in technology of mold milling with coated profile tools
Doležel, Ondřej ; Bumbálek, Bohumil (referee) ; Píška, Miroslav (advisor)
This diploma thesis is involved in possible development of different types of milling molds coated with modern plows. The first part is devoted to an analysis of contemporary trends in forms production technology. The analysis includes the different types of machines and tools for making various kinds of molds and dies. Another part deals with design of dies for sheet metal shears. The thesis continues by design of the production procedure after heat treatment and finishing die by miling. For milling of die are designed miling tools, the NC program and the possible development of manufacturing the die using a new machining center and the possibility of production optimization. The penultimate point of the thesis is technical and economical evaluation of the direction of development and comparison of positives and negatoves of each method. At the final evaluation is all summed up.
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Stability of cathode materials for Li-ion accumulators
Janíček, Zdeněk ; Libich, Jiří (referee) ; Sedlaříková, Marie (advisor)
This diploma thesis focuses on study of positive electrode materials for Li-Ion batteries. Our aim are intercalation materials whose are really perspective materials whose are widely used in this case. The theoretical part of my thesis focus on basic study of Li-ion batteries and their parameters. We studied charging and discharging processes. AFM and SEM were used as additional techniques for study LiCoO2 a Li0,975K0,025CoO2. We tested lifetime and stability of electrode as a perspective material for electrode for Li-ion batteries.
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The cycle modes of lead-acid batteries
Mičák, Tomáš ; Tošer, Pavel (referee) ; Vaculík, Sebastian (advisor)
Main goal of the diploma thesis is to examine lead-acid accumulator and to study cycling modes in different setups. Theoretical part describes history, types of maintenance-free batteries, degradation mechanisms and possibilities to remove them. Practical part involves the production of electrodes and experimental cell, composition of active mass and measurement of internal resistance. Different configurations for deep cycling are researched as well. The results of the work are summarized and commented at the conclusion of the thesis.
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