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Aggregation Behaviour of Polysaccharides in Aqueous Solutions
Mravec, Filip ; Valko, Marián (referee) ; Hrdlovič, Pavol (referee) ; Valko, Marián (referee) ; Pekař, Miloslav (advisor)
Tato práce je zaměřena na agregační chování nativního a hydrofobně modifikovaného hyaluronanu, v různých molekulových hmotnostech a stupních substituce, ve vodném prostředí. Pro studium bylo vybráno šest fluorescenčních sond s různými vlastnostmi (Pyren; Nilská červeň; Perylen; Akridinová oranž; 6-(p-Toluidino)-2-nafthalenesulfonová kyselina; PRODAN). a výsledky získané pomocí těchto sond byly porovnány s jednoduchým anionaktivním tenzidem (Dodecylsíran sodný). U všech použité sond byly testovány jejich spektrální vlastnosti v závislosti na polaritě okolí a/nebo na koncentraci. Pro stanovení vlastností nepolárního jádra hyaluronového agregátu byly vybrány dvě sondy (Pyren, Nilská červeň). U domén byly sledovány polarita a viskozita vnitřního prostředí a jejich závislost na iontové síle a teplotě. Pro modifikované hyaluronany bylo stanoveno, že jejich kritická agregační koncentrace klesá s rostoucí molekulovou hmotností a stupněm substituce. Pro vlastní doménu platí, že její kompaktnost roste s rostoucí iontovou silou, ale klesá s rostoucí teplotou.
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Electrode Materials for Li-S Batteries
Jaššo, Kamil ; Almáši,, Miroslav (referee) ; Syrový,, Tomáš (referee) ; Kazda, Tomáš (advisor)
This thesis is focused on the research of electrode materials for lithium-sulphur (Li-S) batteries, with an emphasis on the optimization of the process of preparation of positive electrodes through the modification of the individual technical steps of the manufacturing process and the selection of a suitable binder. The theoretical part of the thesis is devoted to terminology and battery issues with emphasis on Li-S batteries, their working principle, shortcomings, critical parameters for commercialization and existing research in this field. The practical part of the thesis deals with the influence of the compression pressure used in the production of positive electrodes on the electrochemical properties of the resulting Li-S cells. In the next part of the thesis, the influence of the binder used on the resulting electrochemical properties is investigated. In the following sections, the influence of the thickness of the electrode material layer and the ratio of its individual components (C/S) on the resulting electrochemical properties of the Li-S cell is analyzed. On the basis of the measured results, the optimum conditions for the preparation of the positive electrodes of the Li-S cells have been identified with respect to the individual technical steps of the manufacturing process.
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Analysis of the Language of Internet Forums, Twitter Messages and YouTube Video Comments
CHABR, Ondřej
This thesis deals with computer-mediated communication and the characteristics of language means which are typical for it. The analysis of language is based on a corpus of comments and posts from selected websites. Emphasis is placed on the occurrence of the most frequent features of communication with respect to sociolinguistics. The primary purpose of this study is to determine the language features which each community uses the most and subsequently to compare the individual communities and highlight the different aspects in their communication.
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Facebook English: on the specific features of English netspeak
Mišutková, Anna ; Malá, Markéta (advisor) ; Šaldová, Pavlína (referee)
The aim of this thesis is to describe the language of electronic communication ('netspeak') as one of the present trends of the development of English. The thesis is based on the hypothesis 'netspeak' represents an independent multimodal linguistic variety sharing some features with informal face-to-face conversation. For this purpose, the language of selected samples of the texts of English-speaking students of British universities obtained from the social network Facebook was studied. The qualitative and quantitative analysis of these data and their comparison with spoken form of standard English, namely with the spoken demographically sampled part of the British National Corpus, confirmed the hypothesis. ! Key words: netspeak, CMC, Facebook, emoticons, face-to-face communication, informal conversation
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Psychological aspects of membership in online communities
Janda, Marek ; Štětovská, Iva (advisor) ; Slaměník, Ivan (referee)
This thesis focuses on online communities - both their historic and current form. Various forms of communications are described, main focus is then given to identity online and self-presentation - various forms it can take, which expressive devices are used, how trustworthy is it and how is it perceived by other others. Influence of anonymity is mentioned. Empirical part of this work explores online friendship relations, cornerstone of the current wave of social networking services. It asks several questions about ways in which they affect communication between users. Relation between several factors (reciprocity, direction of initiation of said relation) and both quantity and frequency of communication between those users before and after that friendship is established.
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Aggregation Behaviour of Polysaccharides in Aqueous Solutions
Mravec, Filip ; Valko, Marián (referee) ; Hrdlovič, Pavol (referee) ; Valko, Marián (referee) ; Pekař, Miloslav (advisor)
Tato práce je zaměřena na agregační chování nativního a hydrofobně modifikovaného hyaluronanu, v různých molekulových hmotnostech a stupních substituce, ve vodném prostředí. Pro studium bylo vybráno šest fluorescenčních sond s různými vlastnostmi (Pyren; Nilská červeň; Perylen; Akridinová oranž; 6-(p-Toluidino)-2-nafthalenesulfonová kyselina; PRODAN). a výsledky získané pomocí těchto sond byly porovnány s jednoduchým anionaktivním tenzidem (Dodecylsíran sodný). U všech použité sond byly testovány jejich spektrální vlastnosti v závislosti na polaritě okolí a/nebo na koncentraci. Pro stanovení vlastností nepolárního jádra hyaluronového agregátu byly vybrány dvě sondy (Pyren, Nilská červeň). U domén byly sledovány polarita a viskozita vnitřního prostředí a jejich závislost na iontové síle a teplotě. Pro modifikované hyaluronany bylo stanoveno, že jejich kritická agregační koncentrace klesá s rostoucí molekulovou hmotností a stupněm substituce. Pro vlastní doménu platí, že její kompaktnost roste s rostoucí iontovou silou, ale klesá s rostoucí teplotou.
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