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Viscoelastic properties of hydrogels depending on relative humidity
Kouřilová, Ludmila ; Heger, Richard (referee) ; Smilek, Jiří (advisor)
This bachelor thesis is mainly aimed on the determination of the dependence of the viscoelastic properties of physically crosslinked hydrogels on the relative humidity controlled by humidity cell (as an accessory to a rotary rheometer), or the desiccator with the drying medium. The main objective was to optimise the methodology of the humidity cell for the rheological determination of the viscoelastic properties of hydrogel materials as a function of relative humidity and to verify experimental setup on the agarose hydrogel. The results showed that the agarose hydrogel gradually loses its dispersion medium after exposure to chosen relative humidity, resulting in a loss of contact between the upper rheometer sensor and the sample when measured with the standard measurement gap control setting, which is constant during the measurement. The setting of the control of normal force proved to be an appropriate solution, which has led to a gradual reduction in the height of the upper rheometer sensor in an attempt to keep the normal force at the desired level during the drying of the hydrogel. A humidity cell proves to be an appropriate method for determining the dependence of the viscoelastic properties of hydrogels on relative humidity. Unlike the use of a desiccator with drying medium, the drying of the hydrogel sample does not result in such rapid drying that it breaks the texture on its surface. Another advantage of a humidity cell is the ability to maintain the desired relative humidity value even if the gel begins to release dispersion medium into its surroundings, which was not possible with a desiccator with drying medium.
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Passivation of the active layer in perovskite solar cells with inverted architecture
Babincová, Kristina ; Zmeškal, Oldřich (referee) ; Pospíšil, Jan (advisor)
The topic of this work is the passivation of the active layer of perovskite solar cells with an inverted structure. The work is divided into theoretical and experimental part. The theoretical part describes in particular the passivation and modification of the perovskite layer as well as the characteristic properties of perovskite, including structure and stability. The experimental part deals with the preparation of photovoltaic cells with an inverted structure. For the characterization of photovoltaic cells, reference samples were prepared and their active layer was modified by plasma. The most used deposition technique for the preparation of layers was the spin coating method. From the performed experiments it can be concluded that the preparation of samples and their subsequent modification under laboratory conditions does not lead to the improvement of the final parameters of photovoltaic conversion. By transferring the sample preparation and passivation of the active layer to an inert atmosphere, it was possible to produce cells with higher efficiencies (compared to the reference sample), around 10 %. Another advantage of this plasma treatment of the active layer is that it also improves the stability of the prepared structures, which even after a few days in air show almost 80 % of the original efficiency.
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Klasifikace korozního poškození historického olova a systém prostředků pro jeho konzervaci
Kouřil, Milan ; Ďurovič, Michal ; Bartl, Benjamin ; Strachotová, Kristýna Charlotte ; Msallamová, Šárka
Mnohé muzejní a archivní instituce se v současnosti potkávají s problematikou koroze olověných sbírkových předmětů, uložených v depozitářích, způsobenou citlivostí olova vůči těkavým organickým sloučeninám (VOC), zejména vůči kyselině octové. Zvláštní skupinou těchto olověných předmětů jsou olověné buly (kovové pečeti), které bývají obvykle připojeny k pergamenovým listinám pomocí textilního závěsného materiálu. Metodika zavádí systém kategorizace korozního poškození olověných pečetí a hodnocení podmínek jejich uložení a navrhuje postupy konzervačních opatření vhodné pro možné varianty výsledky průzkumu stavu pečetí a expozičních podmínek. Navržené konzervační postupy jsou založeny především na eliminaci agresivních složek prostředí volbou vhodných obalových materiálů a použitím sorbentů.
Fulltext:  PDF; PDF
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Cafe indoor air quality assesment
Jüthner, Ludvík ; Zíková, Naděžda (advisor) ; Mašková, Ludmila (referee)
Cafes are specific places with increasing popularity these days. However, the spaces used mainly for meetings, work or studying have not been yet explored in detail from the microclimate point of view, although suboptimal microclimatic conditions can have a negative effect not only on employees but also on customers. The bachelor thesis deals with an evaluation of air quality in coffee shops and juxtaposes its findings with the legislation that defines beneficial conditions for the particular environment. The aim of the thesis is to determine whether the values of temperature, relative moisture including the concentration of PM2,5 and carbon dioxide, based on an example of three specific coffee shops situated in the center of Prague, correspond with the acceptable standard quotes stipulated by the law. To that end, the author explores three assumptions: 1) the selected spaces are not strictly controlled by the Public Health Authority in comparison for instance with hospitals and therefore the recorded values do not correspond with the regulations, 2) the number of people worsens the CO2 values and 3) coffee shops with an entrance facing a busy street show a higher concentration of PM2,5. The results were achieved by experimental measuring in Winter months. The theoretical part defines the concept...
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Analysis of Data to Solve Problems with Humidity in Buildings
Nečasová, Klára ; Korček, Pavol (referee) ; Kořenek, Jan (advisor)
The aim of this work was to solve problems with excessive humidity in buildings using data analysis. The theoretical part of the work deals with impacts of excessive humidity on the health of building occupants and also the condition of the building structure. Data mining methods including classification, prediction, and clustering are described together with model evaluation and selection. The practical part focuses on hardware platform description and measurement scenarios. Key parameters affecting indoor relative humidity are indoor and outdoor temperature and outdoor relative humidity. The long-term measurement of the mentioned parameters was performed using the set of sensors and BeeeOn system. Measured data was used to design a system for event detection related to a humidity change. The approach to air change regulation in the room was based on natural ventilation.
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Environment of archives
Onderek, Aleš ; Počinková, Marcela (referee) ; Rubinová, Olga (advisor)
The thesis focuses on the way inventories are stored in depositories. Later on, it develops a project of the air-conditioning system in the archive. The last part of the thesis deals with an experiment which examines the interior environment of the depository.
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