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Functionalized hyper-cross-linked porous polyacetylenes
Havelková, Lucie ; Sedláček, Jan (advisor) ; Brožek, Jiří (referee) ; Balcar, Hynek (referee)
An atom-economic one-step chain-growth coordination homopolymerization providing high yields of functionalized hyper-cross-linked polyacetylenes with permanent micro/mesoporous texture and specific surface area up to 1062 m2 /g was introduced and optimized. Substituted 1,3-diethynylbenzenes served as monomers simultaneously providing functionalization and hyper-cross-linking of the networks. The homopolymerization was compatible with the heteroatom groups of the monomers and allowed to prepare polyacetylene networks with the wide spectrum of univalent functional groups: -F, -Cl, -Br, -NO2, -COOCH3, -CH2OH, -COOH and -CH=O decorating the aromatic segments of the networks in a high extent (7.87 mmol/g). A novel two-step synthesis of functionalized hyper-cross-linked polyacetylenes was introduced combining chain-growth coordination polymerization of acetylenic monomers and covalent templating using acetal and Schiff base protecting groups. By postpolymerization hydrolytic removal of the protecting segments from the primary networks, the networks with a high content (up to 9.61 mmol/g) of univalent functional groups -CH2OH, -CH=O and -NH2 were prepared. These groups were placed either on the cross-linking or linear (aromatic and aliphatic) network segments, even in the vicinity of the main...
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Hybrid materials with improved thermomechanical properties
Perchacz, Magdalena ; Beneš, Hynek (advisor) ; Vlček, Tomáš (referee) ; Brožek, Jiří (referee)
Epoxy resins have been broadly used in the industry for adhesives, laminates, coatings, composites, encapsulation of electronic devices, printed circuit boards, etc. Despite their excellent adhesion to different materials, heat and chemical resistance and good mechanical properties, they also exhibit few drawbacks like brittleness, high thermal expansion coefficient (CTE), poor resistance to crack initiation and growth. Therefore, the thesis is focused on the preparation of epoxy-silica hybrid materials exhibiting improved thermomechanical properties compared to the neat epoxides, without impairing their beneficial features. The main synthetic route of epoxy-silica hybrids' preparation has been the sol-gel process of alkoxysilanes, allowing either in-situ formation of high purity and homogeneity silica particles or creation of various siloxane structures in a form of liquid (sol) silica-based precursors. The sol-gel method, on one hand, helps to omit too high viscosity of nanofiller suspension and energy-intensive nanofiller dispergation problems, but on the other hand, is often associated with necessity to use solvents and to remove formed volatiles. Therefore, in the first part of the thesis, a simple solvent-free sol-gel procedure, enabling to minimize the side-effect of solvent evaporation and...
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Analysis of avalanche activity in Giant Mountains during 1999 - 2009
Veselá, Veronika ; Vomáčko, Ladislav (advisor) ; Brožek, Jiří (referee)
Title: Analysis of the avalanche situation in the Giant Mountains in the period 1999-2009 Objectives of work: Evaluation of weather and terrain conditions in the Czech part of Giant Mountains and the resulting avalanche situation arising. methods: Text analysis and documents relating to the issue lunge avalanches, time series analysis of monitoring weather and snow conditions in the years 1999/2009, the method of interview. results: After each day I announced to assess weather and snow in the winter seasons in 1999-2009. I compared the individual avalanche paths, their parameters and frequency of avalanches falls depending on conditions. Keywords Avalanche, the classification of avalanches, avalanche path, cadastre of avalanche, weather, Giant, climatic conditions
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Exogenous factors selected for the development of football talent
Brožek, Jan ; Perič, Tomáš (advisor) ; Kokštejn, Jakub (referee)
Title: Exogenous factors selected for the development of football talent Targets: The aim of this study was to characterize selected exogenous factors influencing the development of football talent. Find out how and how much these factors influence the football talents in the Czech Republic. Methods: In the work was used qualitative research. Structured interview method was applied to obtain information from agents and football coaches of youth teams. The questionnaire method with open questions was applied to the football talent and stakeholders of football grounds. Comparison method was used to compare the information. Results: The results summarize the degree of influence and share of each factor in the development of football talent in the Czech Republic. Results from questionnaires and interviews are presented in a written summary and presented in the same order in which questions were asked. Keywords: Talent, football, football agent
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Care of plastic bookbindings - conditions of storage, handling and access
Vávrová, Petra ; Neoralová, Jitka ; Knotek, Vítězslav ; Šipošová, Nikola ; Novotná, Dana ; Sharai, Hanna ; Brožek, Jiří, ; Kalousková, Radka ; Malinová, Lenka
Metodika obsahuje informace o plastech vyskytujících se v knihovních fondech a faktorech iniciujících degradační procesy i jejich charakteristické projevy. Jsou představena opatření a strategie manipulace a ukládání knihovních fondů s ohledem na přítomnost syntetických materiálů.
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Restoration and conservation of synthetic binding elements of modern library collection
Vávrová, Petra ; Neoralová, Jitka ; Knotek, Vítězslav ; Šipošová, Nikola ; Novotná, Dana ; Sharai, Hanna ; Brožek, Jiří, ; Kalousková, Radka ; Malinová, Lenka
Cílem daného památkového postupu je přiblížení problematiky péče o knižní vazby obsahující syntetické materiály. Památkový postup reprezentuje výsledky vývoje a ověření metodik a pracovních postupů konzervace a restaurování syntetických materiálů v novodobém knihovním fondu. Dále se památkový postup zaměřuje na popis restaurátorských postupů, k nimž lze přistoupit při výskytu popsaných poškození. Rovněž jsou zde uvedeny doporučené podmínky uložení vazeb se syntetickými prvky a podmínky vystavování vazeb tohoto typu.
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Methodology of plastic bookbindings survey in the modern library collection
Vávrová, Petra ; Neoralová, Jitka ; Novotná, Dana ; Šipošová, Nikola ; Sharai, Hanna ; Knotek, Vítězslav ; Komárek, Josef, ; Brožek, Jiří, ; Kalousková, Radka ; Malinová, Lenka
Cílem předložené metodiky je návodný postup, jak pomocí uvedených technik a metod získat informaci o složení a charakteru syntetických materiálů ve fondu, identifikovat druh materiálu a na základě informací z dalších zdrojů získat přehled o rizicích ovlivňující dobrý fyzický stav fondu. Získané informace umožní kvalifikovaně rozhodnout o způsobu další péče o tyto sbírky. Představená metodika je zaměřena na identifikaci druhů plastů vjemovou i instrumentální, která je nezbytná k eliminaci negativních důsledků degradace plastů v knižní vazbě.
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Microwave-assisted preparation of polymer materials
Bujok, Sonia ; Beneš, Hynek (advisor) ; Brožek, Jiří (referee) ; Duchet-Rumeau, Jannick (referee)
Bearing in mind environmental concerns and global trends in ecology, biodegradable polyesters have gained enormous attention as alternative to non-biodegradable, commercial polymers used mainly in packaging industry contributing to the worldwide environment pollution. However, substitution of conventional polymers with biodegradable polyesters is limited due to their inferior mechanical and barrier properties, which can be improved by the introduction of relatively small content of non-toxic nanofillers. Nevertheless, environmental pollution is not only affected by material itself, but also manufacturing and processing sector in terms of energy sustainability. In case of the latter, low energetic processes are nowadays preferential. Thus, using microwave irradiation as the more efficient energy source, which can lead to shortening of process time, has become currently investigated subject. In this thesis, microwave-assisted in-situ synthesis of biodegradable nanocomposites based on polycaprolactone and non-toxic clay nanoparticles (layered double hydroxides) was studied and described in detail in four subsections (4.1-4.4). The first subsection (4.1) describes one-pot synthesis of Mg2+ /Al3+ layered double hydroxides functionalized with highly microwave-absorbing ionic liquids. In order to improve...
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