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Material Characterization and Modeling of Interband Cascade Light Emitting Diodes
Herzánová, Kristína ; Bastard, Gérald (referee) ; Detz, Hermann (advisor)
Tato práce se zaměřuje na charakterizaci materiálů a ztrátových mechanismů heterostruktur používaných v mezipásových kaskádových zařízeních a na modelování mezi-pásových kaskádových elektroluminiscenčních diod (ICLED). Mezipásová kaskádová zařízení, zejména lasery a elektroluminiscenční diody, mají zásadní význam pro fotonické aplikace ve střední infračervené oblasti vzhledem k jejich efektivitě a možnosti integrace do fotonických obvodů. Studie zahrnuje extrakci materiálových parametrů ze spektroskopické elipsometrie a FTIR měření a rozšíření stávajícího transportního modelu o zářivé rekombinační procesy, konkrétně o spontánní emisi v ICLED. Z různých ztrátových mechanismů v těchto zařízeních byla zvláštní pozornost věnována valenční mezipásové absorpci, která zhoršuje výkon mezipámových kaskádových zařízení v oblasti středních infračervených vlnových délek nad 4 m. Výsledky získané na základě experimentální charakterizace vlnovodů tvořených mezipásovými kaskádovými lasery (ICL) zkoumající jejich přenosové ztráty prokázaly vliv valenční mezipásové absorpce za různých operativních podmínek. Tento výzkum přispívá k optimalizaci struktur mezi-pásových kaskádových struktur, která vede ke zvýšení výkonu a širší použitelnosti v oblasti detekce, monitorování životního prostředí a biomedicínské diagnostiky.
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Lanthanidocenes and their Precursors Synthesis
Kašpárek, Vít ; Hermanová, Soňa (referee) ; Richtera, Lukáš (advisor)
The first section of this bachelor’s thesis aims on a theoretical basis used to characterize new preparation substances, especially x-ray diffraction, infrared spectroscopy, Raman spectroscopy and nuclear magnetic resonance spectroscopy. The next section deals with the basic structural types of lanthanidocenes according to the substituted ligands. The last theoretical section deals with work in the gloves box and the preparation of the laboratory glasses for the work in the inert atmosphere. The aim of the experimental section was the synthesis of methoxyethane, characterization of its purity using FT-IR and its next usage in the change of organic ligands in structure of (C5Me5)SmCl2Li(OEt2)2.
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Characterisation of alcoholic beverages by means of spectrospic methods
Fajtl, Zdeněk ; Omelka, Ladislav (referee) ; Polovka, Martin (advisor)
The bachelor’s project is focused on the problem of determination of thermo-oxidative stability of mixed Radler - type drinks with low alcohol content. The project consists of both, theoretical and practical parts. The theoretical part describes the basic technological procedures used in the production of lager-type beer and also mixed drinks of Radler type. It also deals with the issue of antioxidants and/or oxidative processes with specific focus on beer and its components. The author also pays attention to spectroscopic methods, which are recently extensively applied to characterize different qualitative and quantitative parameters of foods; predominantly UV-VIS, IR and EPR spectroscopy. These methods were chosen with respect to the topic being studied. In the experimental part, the application of EPR spectroscopy and spin traps methods for the characterization of thermo-oxidative stability of the selected group of commercially available samples of Radler-type beer is presented. The values of the induction periods which were taken as a measure of thermo-oxidative stability, are compared, both for the group of Radler-type beers under study and for the commercially available samples of typical lager-type beers of identical producers, which were taken as for reference.
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Characterisation of alcoholic beverages by means of spectrospic methods
Fajtl, Zdeněk ; Omelka, Ladislav (referee) ; Polovka, Martin (advisor)
The bachelor’s project is focused on the problem of determination of thermo-oxidative stability of mixed Radler - type drinks with low alcohol content. The project consists of both, theoretical and practical parts. The theoretical part describes the basic technological procedures used in the production of lager-type beer and also mixed drinks of Radler type. It also deals with the issue of antioxidants and/or oxidative processes with specific focus on beer and its components. The author also pays attention to spectroscopic methods, which are recently extensively applied to characterize different qualitative and quantitative parameters of foods; predominantly UV-VIS, IR and EPR spectroscopy. These methods were chosen with respect to the topic being studied. In the experimental part, the application of EPR spectroscopy and spin traps methods for the characterization of thermo-oxidative stability of the selected group of commercially available samples of Radler-type beer is presented. The values of the induction periods which were taken as a measure of thermo-oxidative stability, are compared, both for the group of Radler-type beers under study and for the commercially available samples of typical lager-type beers of identical producers, which were taken as for reference.
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Lanthanidocenes and their Precursors Synthesis
Kašpárek, Vít ; Hermanová, Soňa (referee) ; Richtera, Lukáš (advisor)
The first section of this bachelor’s thesis aims on a theoretical basis used to characterize new preparation substances, especially x-ray diffraction, infrared spectroscopy, Raman spectroscopy and nuclear magnetic resonance spectroscopy. The next section deals with the basic structural types of lanthanidocenes according to the substituted ligands. The last theoretical section deals with work in the gloves box and the preparation of the laboratory glasses for the work in the inert atmosphere. The aim of the experimental section was the synthesis of methoxyethane, characterization of its purity using FT-IR and its next usage in the change of organic ligands in structure of (C5Me5)SmCl2Li(OEt2)2.
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