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Mechanical propertties gel polymer aprotic electrolytes
Bárta, Vladimír ; Musil, Michal (referee) ; Sedlaříková, Marie (advisor)
This work deals with the measurement of electrical conductivity and mechanical properties of gel polymer electrolyte containing Lithium ion and their preparation. The theoretical part deals with the development of gel polymer electrolyte, their use and methods of measurement of electrical conductivity and mechanical properties. In the experimental part describes the preparation of gel electrolyte, the measurement of electrical conductivity, temperature dependence and the measurement of mechanical properties.
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Compatibility of selected dental alloys with magnetic resonance imaging
Linetskiy, Igor ; Hubálková, Hana (advisor) ; Suchánek, Jakub (referee) ; Dostálová, Taťjana (referee)
Magnetic resonance imaging (MRI) is one of the up-to-date and perspective methods of diagnostic medical imaging. It is highly valued for absence of ionizing radiation, non-invasiveness, acquiring of highly accurate images of hard and especially soft tissues in any plane. It is a method of choice in central nervous system imaging. Nowadays it is used in diagnostics of other diseases in the maxillofacial area. The major shortcoming of MRI is interaction of magnetic fields of MRI system with metallic objects present in human body. As a result, this may lead to their heating, movement, and also to imaging artifacts. Since different metallic constructions (fixed bridges, dental implants, splints, plates, orthodontic appliances, etc.) are often used in the contemporary dentistry, the problem of their compatibility with MRI is relevant. The aim of this study was to validate the compatibility of dental alloys with MRI, classify the materials according to the degree of compatibility and to establish the range of their possible negative impact on quality of MRI in head and neck area. In order to find dental metals and alloys, General Health Insurance Company code- list, catalogues of manufacturers' and Prague dental labs were used. Measurement methods of magnetic susceptibility (MS), electric conductivity...
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Changes of physical-chemical parameters of surface water in context with hydrological extremes. Application in the Rolava River catchment.
Šajnarová, Lucie ; Matoušková, Milada (advisor) ; Havlíková, Petra (referee)
6 Abstract The diploma thesis deals with changes in the physico-chemical parameters of surface flows in response to extremes, especially increased flows due to higher precipitation totals or melting snow. The basin of the upper Rolava with peat bogs in the basin and minimal anthropogenic influence was used. The main goal of the work was the analysis of the behavior of electrical conductivity during events when there was an increase in flow rates and the categorization of individual events according to this behavior. Furthermore, the influence of the pre-condition of the watershed on the events and the subsequent behavior of the electrical conductivity was also investigated. The 10-minute electrical conductivity and flow data from the automatic stations of the ecohydrology team of the Faculty of Science, UK, or ČHMÚ were used. Among the methods are data homogenization, construction of hysteresis loops, categorization of loops, calculation of indices for hysteresis loops and PCA analysis for the pre-condition of the watershed. In most cases, a reverse relationship of electrical conductivity behavior was observed during these events, the most common types of electrical conductivity behavior during flow increases include a slow decrease in conductivity with minimum values after the peak of flow (in light...
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Development of grounding enhancing cement composite mixture
Sochor, David ; Dohnálek,, Pavel (referee) ; Drochytka, Rostislav (advisor)
The diploma thesis deals with the development of a conductive cement composite grounding mixture for protection of building structures in areas with low conductivity. The theoretical part is focused mainly on the methods of buildings protections against lightning and overvoltage. The aim of this is to create a conductive composite with the possible use of secondary raw materials, which have a low electrical impedance value. The conclusion of the thesis is devoted to the evaluation of the efficiency of newly designed conductive composites and their possibility of incorporation into building protection systems against lightning or overvoltage.
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Silicate Conductive Composites with Graphite Fillers
Baránek, Šimon ; Drochytka, Rostislav
Electroconductive composites are modern materials that are commonly used in many industries such as construction industry and machine-building industry. For example, these materials can be useful as sensors for monitoring changes in constructions, shielding stray currents from electrification networks, shielding electromagnetic radiation in operating rooms, cathodic protection against moisture or overvoltage protection of buildings. The topic of this post is the research of electrically conductive silicate composites with graphite-based fillers. In this research, composites with different ratios and types of graphite were tested and electroconductive properties such as impedance were monitored, as well as physical-mechanical properties such as strength. It was found that by adding 10 wt. graphite into the mixture reduces the impedance of the composites by 50 % and the compressive strength is reduced by approximately 40 %.
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Impacts of hydrological extremes on surface water quality in headwater areas. Application in the model study area of the upper Rolava catchment.
Šajnarová, Lucie ; Matoušková, Milada (advisor) ; Havlíková, Petra (referee)
Precipitation-runoff extremes in the source areas have a significant effect on changes in the geochemism of surface waters, which also affect peatlands in the basin. The main goals of this theses include research literature on the topic of changes in the geochemism of surface waters in spring areas with peat bogs in the basin in response to precipitation-runoff extremes. Furthermore, an analysis of runoff and precipitation conditions in the hydrological years 2018, 2019 and 2020 and an analysis of changes in water quality parameters depending on precipitation-runoff extremes for the period from 2013 to 2020 were performed. The relationship between conductivity and flow was monitored using hysteresis loops. The work used data from the experimental profile of KFGG PřF UK on the Slatinný potok and data on flows for the profile Chaloupky in the Rolava from ČHMÚ. The results show that the relationship between conductivity and flow can be analyzed using hysteresis loops, especially in the period with a rapid increase in flow and their shape changes depending on the reconditioning of the basin. Flow dependence was also observed for other parameters, such as iron. Keywords: hydrological drought, flood, surface water quality, peat bog, electrical conductivity, hysteresis loop
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Gel aprotic electrolytes with tetraalkylamonium salts
Michalec, Juraj ; Veselkova, Iuliia (referee) ; Sedlaříková, Marie (advisor)
The essence of this graduate thesis is to summarize knowledge about the aprotic gel electrolytes. In the graduate thesis, there are explained methods for mensuration electrochemical properties of the aprotic gel electrolytes. In the theoretical part, I focus on the knowledge related to gel polymeric electrolytes, their history, properties, mechanisms and application. In the experimental part, I describe the preparation of the samples of the gel polymeric electrolytes, in which I evaluate their properties, electrical conductivity and potencial window.
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Effects of soil management on soil quality near Šardičky village
Schneiderová, Šárka ; Doležal, Petr (referee) ; Kameníčková, Ivana (advisor)
This diploma thesis is focused on influence of reduced tillage technology of soil processing on it´s near-surface soil layer (0 to 10 cm). The research was carried out on agricultural land near Šardičky village, where company ZEMO spol. s r.o. provides long-term use of reduced tillage technology. In 2016 the soil quality in this site was evaluated by using physical and hydrophysical parameters, results are presented in the previous bachelor thesis "Selected hydrophysical parameters as indicators of soil quality.". In diploma thesis in addition chemical and other hydrophysical properties have been evaluated to provide a comprehensive assessment of soil quality. In 2016, poppy seed was grown on this site and spring barley was grown in 2017 and 2018. Grab samples and intact soil cores were taken during the vegetation period of the crop. After three years of experimental research, in which I participated, it is possible to assess the development of individual parameters and the influence of reduced tillage technology on near-surface soil layer. The theoretical part of the diploma thesis deals with the description of the reduced tillage technology and problematics of the determination of soil parameters, which are used for evaluation of the quality of the near-surface layer. The practical part deals with evaluation of these parameters according to various authors and describes the development of soil quality during years 2016, 2017 and 2018.
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Manufacture of castings from electrical copper
Janský, Vojtěch ; Lána, Ivo (referee) ; Záděra, Antonín (advisor)
The goal of this thesis is to verify influence of conditions of metallurgical treatment, used foundry technology and conditions of solidification on electrical conductivity of pure copper castings. The experiment part observe differenec between alloy melting under normal pressure and in a vacuum and betwwen casting provided with chill, insulation and natural enviroment of mould.
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