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Methods for localization of pulsed broadband signal source
Machala, Petr ; Hadinec, Michal (referee) ; Drexler, Petr (advisor)
The topic of this barchelor’s thesis is the analysis of problems regarding localization of partial discharges (PD) and related PD recording, processing and interpretation in time and frequency domain. In majority of cases the occurrence of partial discharges refers to a certain defect in the measured device, therefore in practice (eg large equipment such as oil transformers) it appears to be very useful and economical to determine the exact position, where PDs are formed. To address these complex issues, it is necessary to design the entire measuring chain from PD detection to measured data processing and localization itself. In terms of data processing and PD localization many different localization and detection methods can be applied, some of them are presented in this documentation. These methods are gradually studied, implemented and afterwards tested using the input data of the experiment.
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Effect of compaction pressure to the electrochemical properties of the electrodes for Li-S accumulators
Jaššo, Kamil ; Tichý, Jiří (referee) ; Kazda, Tomáš (advisor)
The purpose of this diploma thesis is to describe the impact of compaction pressure on the electrochemical parameters of lithium-sulfur batteries. Theoretical part of this thesis contains briefly described terminology and general issues of batteries and their division. Every kind of battery is provided with a closer description of a specific battery type. A separate chapter is dedicated to lithium cells, mainly lithium-ion batteries. Considering various composition of lithium-ion batteries, this chapter deeply analyzes mostly used active materials of electrodes, used electrolytes and separators. Considering that the electrochemical principle of Li-S and Li-O batteries is different to Li-ion batteries, these accumulators of new generation are included in individual subhead. In the experimental part of this thesis are described methods used to measure electrochemical parameters of Li-S batteries. Next chapter contains description of preparing individual electrodes and their composition. Rest of the experimental part of my thesis is dedicated to the description of individual experiments and achieved results.
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Detection of paroxysmal atrial fibrillation and atrial flutter
Krmela, Jan ; Němcová, Andrea (referee) ; Smíšek, Radovan (advisor)
This bachelor thesis deals with the problem of atrial fibrillation and flutter, the pathophysiology of these arrhythmias and their automatic detection. It includes a theoretical introduction necessary to understand the basal anatomy of the heart, its function, the origin and description of the electrocardiogram and a chapter on cardiac arrhythmias. It also includes a review of automatic detection of atrial fibrillation. The databases used in the practical part of the thesis are also described. The implementation of heart rhythm classification and automatic detection of the beginning and end of paroxysmal episodes is performed in MATLAB environment, the proposed algorithm is tested on the described databases and the results are evaluated.
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Detection of paroxysmal atrial fibrillation and atrial flutter
Krmela, Jan ; Němcová, Andrea (referee) ; Smíšek, Radovan (advisor)
This bachelor thesis deals with the problem of atrial fibrillation and flutter, the pathophysiology of these arrhythmias and their automatic detection. It includes a theoretical introduction necessary to understand the basal anatomy of the heart, its function, the origin and description of the electrocardiogram and a chapter on cardiac arrhythmias. It also includes a review of automatic detection of atrial fibrillation. The databases used in the practical part of the thesis are also described. The implementation of heart rhythm classification and automatic detection of the beginning and end of paroxysmal episodes is performed in MATLAB environment, the proposed algorithm is tested on the described databases and the results are evaluated.
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Preparation and characterization of bis(terpyridyl)fluorene based polymers
Hrma, Martin ; Svoboda, Jan (advisor) ; Strachota, Adam (referee)
The diploma thesis presents the preparation of ,-bisterpyridinylfluorenes (unimers) containing fluorene unit in the central block either directly attached to terpyridine (tpy) end groups or via 1,4-phenylene or thiophene-2,5-diyl linker. Synthesized unimers were subsequently used for the preparation of metallo-supramolecular polymers with Zn2+ and Fe2+ ions. The prepared unimers were characterized by NMR, IR and HR-MS, their optical properties were investigated using absorption and emission spectroscopy and cyclic voltammetry. Molecular weight distribution for the prepared Fe-polymers was determined by GPC. The number-average degree of polymerization equal to 7 for an equimolar ratio between unimer and Fe2+ in a diluted solution was determined for polymers composed of unimer with thiophene-2,5- diyl linker. By using the viscometric measurements the ongoing constitutional dynamics in solutions of metallo-supramolecular polymers was proven. The overstoichiometric amount of metal ions in solution resulted in equilibrium shortening of the polymer chains together with end-capping of terminal tpy ligands by Mt2+ ions. Unimer with thiophene-2,5-diyl linker exhibited unique properties involving significantly red-shifted absorption and emission maxima, as well as the different behavior during assembling...
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Preparation and characterization of bis(terpyridyl)fluorene based polymers
Hrma, Martin
The diploma thesis presents the preparation of ,-bisterpyridinylfluorenes (unimers) containing fluorene unit in the central block either directly attached to terpyridine (tpy) end groups or via 1,4-phenylene or thiophene-2,5-diyl linker. Synthesized unimers were subsequently used for the preparation of metallo-supramolecular polymers with Zn2+ and Fe2+ ions. The prepared unimers were characterized by NMR, IR and HR-MS, their optical properties were investigated using absorption and emission spectroscopy and cyclic voltammetry. Molecular weight distribution for the prepared Fe-polymers was determined by GPC. The number-average degree of polymerization equal to 7 for an equimolar ratio between unimer and Fe2+ in a diluted solution was determined for polymers composed of unimer with thiophene-2,5- diyl linker. By using the viscometric measurements the ongoing constitutional dynamics in solutions of metallo-supramolecular polymers was proven. The overstoichiometric amount of metal ions in solution resulted in equilibrium shortening of the polymer chains together with end-capping of terminal tpy ligands by Mt2+ ions. Unimer with thiophene-2,5-diyl linker exhibited unique properties involving significantly red-shifted absorption and emission maxima, as well as the different behavior during assembling...
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Effect of Compaction Pressure to the Electrochemical Properties of the Electrodes for Li-S Accumulators
Jaššo, Kamil
Over the last decade, demand for batteries increased a lot thanks to the wearable devices and electric cars. The current trend in all industries is reducing the size and weight of batteries and increasing their capacity. The demand for even more powerful batteries is often faced with theoretical and practical limits of the technology. Battery industry compared to other industries is just slightly behind and batteries became a limiting factor for technologies.The purpose of this experiment is to describe the impact of compaction pressure on the electrochemical properties of the positive electrode for lithium-sulfur batteries.
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Možnosti fixace vzorků pro měření obsahu DNA u ryb průtokovou cytometrií
HUBÁLEK, Martin
This thesis aims to assess the possibility of the usage of various biological fixatives for fish cell and tissues samples in order to extend its storage for later flow cytometric measurement of DNA content. The model species chosen were sterlet and tench, from which three types of samples were obtained: blood and fin tissue of subadult / adult individuals and tail tissue of hatched larvae. Altogether 13 fixation methods were tested for each type of sample of both model species. Methods were chosen based upon their easy feasibility and low time-consumption. The samples were measured on flow cytometer in native state immediately after sampling and placing in physiological saline and after 1, 5 and 10 days of fixation during which they were stored in a fridge or in a freezer at -80 ?C. Their analysis was carried out simultaneously with standards native cells from tench fin tissue when investigating sterlet samples, and commercially available fixed trout erythrocytes for tench samples. A fluorochrome used was 4',6-diamidine-2'-phenylindole dihydrochloride (DAPI; with excitation/emission maxima 358 / 461 nm). Based on the evaluation of coefficients of variation (CV) of fixed samples and the changes in their fluorescence levels in comparison with native state, optimal procedures for extended storage of all types of samples from both model species are suggested.
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Preparation and characterization of bis(terpyridyl)fluorene based polymers
Hrma, Martin
The diploma thesis presents the preparation of ,-bisterpyridinylfluorenes (unimers) containing fluorene unit in the central block either directly attached to terpyridine (tpy) end groups or via 1,4-phenylene or thiophene-2,5-diyl linker. Synthesized unimers were subsequently used for the preparation of metallo-supramolecular polymers with Zn2+ and Fe2+ ions. The prepared unimers were characterized by NMR, IR and HR-MS, their optical properties were investigated using absorption and emission spectroscopy and cyclic voltammetry. Molecular weight distribution for the prepared Fe-polymers was determined by GPC. The number-average degree of polymerization equal to 7 for an equimolar ratio between unimer and Fe2+ in a diluted solution was determined for polymers composed of unimer with thiophene-2,5- diyl linker. By using the viscometric measurements the ongoing constitutional dynamics in solutions of metallo-supramolecular polymers was proven. The overstoichiometric amount of metal ions in solution resulted in equilibrium shortening of the polymer chains together with end-capping of terminal tpy ligands by Mt2+ ions. Unimer with thiophene-2,5-diyl linker exhibited unique properties involving significantly red-shifted absorption and emission maxima, as well as the different behavior during assembling...
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