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Use of copolymer polyhydroxyalkanoates in development of intelligent packaging
Kreuzerová, Monika ; Kalina, Michal (referee) ; Sedláček, Petr (advisor)
This bachelor thesis deals with the preparation and characterization of copolymers P(3HB-co-4HB). The theoretical part discusses polyhydroxyalcanolates (PHA), where their structure, properties and synthesis are described and subsequently the selected copolymers, which contain monomeric units 3HB, are listed. Furthermore, the review part is processed for the current state of the issue, which states the use of copolymers PHA and current research work on the incorporation of active substances into copolymers. The aim of this work was to characterize and compare the created P(3HB) and P(3HB-co-4HB) foils with a 4HB monomeric unit of 65,25 % and 43,61 % and subsequently determine the potential of foil usability as intelligent packaging materials. First, PHA were subjected to gas chromatography, SEC-MALS, FTIR and DSC analysis. In the second part of the thesis, the permeability of foils to water vapor and the release of model active substances from PHA foils was studied. For this purpose, two active substances (curcumin and salicylic acid) were selected, which were incorporated into a film of homopolymer P(3HB) and two copolymers with a proportion of 4HB of 65,25 % and 43,61 %. In foils prepared from copolymers, the active substances diffusion was faster than in P(3HB). Within the copolymers, P(3HB-co-43,61%4HB) released substances at a higher speed, due to the greater crystallinity of a copolymer containing 65,25 % 4HB.
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Use of copolymer polyhydroxyalkanoates in development of intelligent packaging
Kreuzerová, Monika ; Kalina, Michal (referee) ; Sedláček, Petr (advisor)
This bachelor thesis deals with the preparation and characterization of copolymers P(3HB-co-4HB). The theoretical part discusses polyhydroxyalcanolates (PHA), where their structure, properties and synthesis are described and subsequently the selected copolymers, which contain monomeric units 3HB, are listed. Furthermore, the review part is processed for the current state of the issue, which states the use of copolymers PHA and current research work on the incorporation of active substances into copolymers. The aim of this work was to characterize and compare the created P(3HB) and P(3HB-co-4HB) foils with a 4HB monomeric unit of 65,25 % and 43,61 % and subsequently determine the potential of foil usability as intelligent packaging materials. First, PHA were subjected to gas chromatography, SEC-MALS, FTIR and DSC analysis. In the second part of the thesis, the permeability of foils to water vapor and the release of model active substances from PHA foils was studied. For this purpose, two active substances (curcumin and salicylic acid) were selected, which were incorporated into a film of homopolymer P(3HB) and two copolymers with a proportion of 4HB of 65,25 % and 43,61 %. In foils prepared from copolymers, the active substances diffusion was faster than in P(3HB). Within the copolymers, P(3HB-co-43,61%4HB) released substances at a higher speed, due to the greater crystallinity of a copolymer containing 65,25 % 4HB.
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Golden foils from Borg - iconographical and religious analysis
Gorroňová, Marianna ; Starý, Jiří (advisor) ; Janák, Jiří (referee)
5A Abstract This work gives the analysis of iconographic elements which are found on five gold foils. These foils depict two figures which look at each other from their profile. Foils were found in the foundations of the chieftain house in Lofot's islands in Northern Norway, which is from the Migration to the Viking period. For the reason of analysis the author demonstrates three main groups of gold objects - gold bracteates, gold foils and one medallion. On these objects we can find a pair of two figures and these objects were found in Scandinavia. The author presents here the context of such finds, iconographic elements and academic interpretations of the depiction. Author compares the elements such as type of foil, appearance of eyes, posture of man and woman, their dress and haidress with 91 foils from Scandinavia, and also with bracteates and other objects. She notices the partial concordance among these elements and the other objects and she seeks the iconographic essence and function of each foil from Borg which is later confronted with the theories of the influence of religion. Because of lack of attributes on the foils, the author's assumption is that there is no general depiction of gods on the foil. On the other hand, each foil has its own story showing people from their common life. According to...
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Golden foils from Borg - iconographical and religious analysis
Gorroňová, Marianna ; Starý, Jiří (advisor) ; Janák, Jiří (referee)
5A Abstract This work gives the analysis of iconographic elements which are found on five gold foils. These foils depict two figures which look at each other from their profile. Foils were found in the foundations of the chieftain house in Lofot's islands in Northern Norway, which is from the Migration to the Viking period. For the reason of analysis the author demonstrates three main groups of gold objects - gold bracteates, gold foils and one medallion. On these objects we can find a pair of two figures and these objects were found in Scandinavia. The author presents here the context of such finds, iconographic elements and academic interpretations of the depiction. Author compares the elements such as type of foil, appearance of eyes, posture of man and woman, their dress and haidress with 91 foils from Scandinavia, and also with bracteates and other objects. She notices the partial concordance among these elements and the other objects and she seeks the iconographic essence and function of each foil from Borg which is later confronted with the theories of the influence of religion. Because of lack of attributes on the foils, the author's assumption is that there is no general depiction of gods on the foil. On the other hand, each foil has its own story showing people from their common life. According to...
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