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Effect of heat treatments on the microstructure and hardness of high-entropy alloy
Jesenská, Mária Ľudmila ; Adam, Ondřej (referee) ; Moravčíková de Almeida Gouvea, Larissa (advisor)
V tejto práci je študovaná neekviatomická Al0.2Co1.5CrFeNi1.5Ti vysoko entropická zliatina, ktorá bola vyrobená pomocou vákuového indukčného tavenia. Zliatina v odliatom stave bola analyzovaná a tepelne spracovaná pri teplote 1000 °C po dobu 5h, a následne podrobená tepelnému spracovaniu pri teplote 750 °C po dobu ďalších 5h, s cieľom skúmania vplyvu teploty a doby tepelného spracovania na fázové zloženie, mikroštruktúru a mechanické vlastnosti. Na vyhodnotenie možných fáz prítomných v zliatine bol použitý pseudobinárny fázový diagram (CALPHAD). Mikroštruktúra zliatin bola charakterizovaná a chemicky analyzovaná pomocou röntgenovej difrakcie (XRD), elektrónovej mikroskopie (SEM) a energeticky disperznej spektroskopie. Výsledné vyhodnotenie tvrdosti materiálu prebehlo pomocou skúšok mikrotvrdosti a nanoindentácie.
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Identification of yeasts from interspecific varieties of grapes
Sadel, Peter ; Omelková, Jiřina (referee) ; Vránová, Dana (advisor)
The main goal of my diploma thesis was to identify and characterize yeasts from must Hibernal and also collection yeasts by using methods called RFLP-PCR (Restriction Fragment Length Polymorphism - Polymerase Chain Reaction). Theory was the first part of my diploma thesis which dealt with wine, yeasts and molecular methods. Theory section was followed by experimental section divided into two parts. The main goal of the first part was to characterize and identify yeasts from must Hibernal by using PCR and RFLP-PCR methods. In the samples there were found yeasts Saccharomyces and Pichia. The second experimental part of my diploma thesis had a goal to extend the database of new yeasts using the same methods mentioned in the first part of experimental section.
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Preparation and Characterization of Biochar - the Effect of Pyrolysis Conditions and the Source of Used Biomass
Novotný, Maximilián ; Pořízka, Jaromír (referee) ; Kalina, Michal (advisor)
This diploma thesis is focused on preparation of biochar samples, which were characterized to reveal influence of preparation conditions on biochar properties physical-chemical properties. Preparation conditions covered temperature range of 400 °C to 700 °C and 2 different residence times were used. Biochars from each source biomass has its own characteristics, however the similiarities between biochars from different sources were found. Biochar yields were specified and the minimum yield was at least 24 %. Analysis on content revealed, that oat brans, mixed wood and corn residue contain a lot of organic matter, relatively, and also contains a lot of organic carbon. Results of structural analysis confirmed individual structural properties, porosity and content of function groups in particular. Influence of higher pyrolysis temperature results in slightly lower yields, however it provides products with higher content of organic carbon and higher surface area, in majority of cases. Subsequently, it was found out that short residence time of 10 minutes does not have to be enough for all used biomasses. On the basis of gained data, the preparation or production can be optimalized in effort to make usage of residue biomass more effective in different application, not only in agronomy sector.
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Preparation and Characterization of Biochar - the Effect of Pyrolysis Conditions and the Source of Used Biomass
Novotný, Maximilián ; Pořízka, Jaromír (referee) ; Kalina, Michal (advisor)
This diploma thesis is focused on preparation of biochar samples, which were characterized to reveal influence of preparation conditions on biochar properties physical-chemical properties. Preparation conditions covered temperature range of 400 °C to 700 °C and 2 different residence times were used. Biochars from each source biomass has its own characteristics, however the similiarities between biochars from different sources were found. Biochar yields were specified and the minimum yield was at least 24 %. Analysis on content revealed, that oat brans, mixed wood and corn residue contain a lot of organic matter, relatively, and also contains a lot of organic carbon. Results of structural analysis confirmed individual structural properties, porosity and content of function groups in particular. Influence of higher pyrolysis temperature results in slightly lower yields, however it provides products with higher content of organic carbon and higher surface area, in majority of cases. Subsequently, it was found out that short residence time of 10 minutes does not have to be enough for all used biomasses. On the basis of gained data, the preparation or production can be optimalized in effort to make usage of residue biomass more effective in different application, not only in agronomy sector.
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|
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Effect of heat treatments on the microstructure and hardness of high-entropy alloy
Jesenská, Mária Ľudmila ; Adam, Ondřej (referee) ; Moravčíková de Almeida Gouvea, Larissa (advisor)
V tejto práci je študovaná neekviatomická Al0.2Co1.5CrFeNi1.5Ti vysoko entropická zliatina, ktorá bola vyrobená pomocou vákuového indukčného tavenia. Zliatina v odliatom stave bola analyzovaná a tepelne spracovaná pri teplote 1000 °C po dobu 5h, a následne podrobená tepelnému spracovaniu pri teplote 750 °C po dobu ďalších 5h, s cieľom skúmania vplyvu teploty a doby tepelného spracovania na fázové zloženie, mikroštruktúru a mechanické vlastnosti. Na vyhodnotenie možných fáz prítomných v zliatine bol použitý pseudobinárny fázový diagram (CALPHAD). Mikroštruktúra zliatin bola charakterizovaná a chemicky analyzovaná pomocou röntgenovej difrakcie (XRD), elektrónovej mikroskopie (SEM) a energeticky disperznej spektroskopie. Výsledné vyhodnotenie tvrdosti materiálu prebehlo pomocou skúšok mikrotvrdosti a nanoindentácie.
|
|
|
Identification of yeasts from interspecific varieties of grapes
Sadel, Peter ; Omelková, Jiřina (referee) ; Vránová, Dana (advisor)
The main goal of my diploma thesis was to identify and characterize yeasts from must Hibernal and also collection yeasts by using methods called RFLP-PCR (Restriction Fragment Length Polymorphism - Polymerase Chain Reaction). Theory was the first part of my diploma thesis which dealt with wine, yeasts and molecular methods. Theory section was followed by experimental section divided into two parts. The main goal of the first part was to characterize and identify yeasts from must Hibernal by using PCR and RFLP-PCR methods. In the samples there were found yeasts Saccharomyces and Pichia. The second experimental part of my diploma thesis had a goal to extend the database of new yeasts using the same methods mentioned in the first part of experimental section.
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