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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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Beginning teacher of (not only) biology
Nedavašková, Michaela ; Rajsiglová, Ina (advisor) ; Kotvaltová Sezemská, Karolína (referee)
This work provides an insight into the professional start of beginning teachers which is key for their future direction. It turns out that many teachers leave the profession during the first years. The first part defines the concept of the induction period and highlights its importance, describes the role of the mentor and school management, and then the difficulties and needs of beginning teachers. The second part is devoted to the German and Swedish educational systems and primarily focuses on their approaches and ways of induction of beginning teachers. Germany was chosen based on its unique system of two-phase teacher education and Sweden as a representative of the Nordic countries investing a significant proportion of its government budget into education. Key words: beginning teacher, induction period, mentoring, induction of beginning teachers
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Drop-out of the beginning teachers
Krejčová, Martina ; Zvírotský, Michal (advisor) ; Thorovská, Alena (referee)
The Diploma thesis focuses on the drop-out of beginning teachers. Theoretical part elaborates on the phenomenon of drop-out, it describes the reasons why the beginning teachers leave and why they are the group of teachers which is the most threatened by drop-out. Furthermore, this part describes problems that beginning teachers have to deal with and the most frequent reasons for leaving the profession, their rate and consequences of drop-out. The end of the theoretical part presents options and suggestions that would help solve this problem. The empirical part of the thesis is realized by an on-line questionnaire and in-depth interviews. The research focuses on four main aspects: 1 - the motivation to study the teaching and to practise it, 2 - the main reasons for new teachers to leave, 3 - the possibilities to prevent drop-out and 4 - whether the respondents continue to work with children or not. Last but not least, the research focuses on the possibilities that would help respondents to stay in the profession. The results of the research confirm the reasons for quiting as described by literature. The qualitative description of the reasons for drop-outs provides a deeper understanding of how they interact in an institutional, interactive and cultural level. KEYWORDS Induction period, teacher...
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Evaluation of stability of selected vegetable oils
Němečková, Lenka ; Lehocký,, Marián (referee) ; Zemanová, Jana (advisor)
This diploma thesis is focused on issues concerning the stability of selected vegetable oils which are used in cosmetic industry. The stability of eight oils without additives were determined by a differential scanning calorimeter. In the first phase, the temperatures of oil degradation were determined for different rates of heating, i.e. nonisothermal stabilities. They were consequetly used to calculate isothermal stabilities alias induction periods. The calculation of induction periods was completed by using integral isoconversional methods, which applied four different temperature functions. One of the temperature functions corresponded to Arrhenius equation while the others to non-Arrhenius functions. The confrontation of induction periods under standart conditions showed that an optimal temperature function to calculate oil stabilities is one of the non-Arrhenius functions in exponential form. We can state that all oils are degraded by similar, if not the same, mechanism. The specified stabilities, in periods of months, have proved the importance of using stabilizers and other additives in the commercial and technological use of vegetable oils.
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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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