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The influence of PEO source on nanofiber layer preparation
Grufíková, Jana ; Knotek,, Petr (referee) ; Knotková, Kateřina (advisor)
The electrospinning process of polymer solutions is affected by many different parameters that can be divided into solution parameters, process parameters, and ambient parameters. This study is focused on characteristics of a polymer and its solution, which are ranging into the solution parameters. The aim of this study is to compare poly(ethylene oxide) characteristics in the relation to electrospinning of hyaluronic acid, to find the difference between them using available analytic, thermic and spectral methods, and to define the influence of properties on polymeric solutions behavior during electrospinning. It was find that poly(ethylene oxides) obtained from two different sources behave differently in an electrostatic field, although their molar mass is declared as the same. It was also confirmed that the electrospinning process of polymeric solutions is affected mainly by their viscosity and conductivity. This two properties are determined especially by the molar mass of polymer and also by the content of impurities or content of some another polymer during electrospinning of mixed solution.
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Tracking the evolution and stability of metal nanoparticles in zeolites by in-situ heating electron microscopy
Krakl, František ; Mazur, Michal (advisor) ; Knotková, Kateřina (referee)
Zeolites, with their unique characteristics, such as microporosity, thermal stability, and shape selectivity, are used as a support for metal nanoparticles to enhance their catalytic properties. Metal nanoparticles have a large attainable surface in relation to their mass, thus volume. There are several ways of supporting metal on zeolites, such as ion-exchange, impregnation, or direct encapsulation during synthesis. The latter method provides the stability of metal, however, even the zeolite-encapsulated nanoparticles are not fully sinter-resistant, especially at high temperatures. Insights into the sintering mechanism is crucial for improvement of stability of supported metal catalysts. In this work platinum nanoparticles were directly introduced into chabazite (CHA) zeolite during hydrothermal synthesis. The goal of this thesis was to understand metal nanoparticle sintering mechanisms. the role of aluminium content in zeolite framework in the stabilisation of metal nanoparticles was described. The structure of prepared materials was confirmed by powder X-ray diffraction. Inductively coupled plasma mass spectrometry was used to determine the elemental composition of the materials and their distribution in crystals was mapped by energy dispersive X-ray spectroscopy in a scanning transmission...
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Využití bylin v procesu úsporného hospodaření s vodou
Knotková, Kateřina
The presented master study is focused on sustainable rain water management with emphasis on proper use of plants in the process. This thesis connects information from foreign countries and puts them into context of Czechclimatic conditions and Czechlegal and technical standards. It defines term “dešťový záhon“ (rain flower bed) as a landscape element for rainwater infiltration that combines aesthetical, ecological and water management functions. Technical aspect and assortment of usable plant species is critically evaluated. Suitable technical variants are “vsakovací průleh” (rain garden), “vsakovací průleh s rýhou” (bioretencion system) a “vsakovací průleh s rýhou a regulovaným odtokem” (bioretencion system). The study includes also few examples of realized rain water management solutions. Drought tolerant species looks surprisingly as most promising for use in “rain flower beds“. Combination of annual, biennial etc. plants is possible; however perennials are most promising, while shrubs and trees usage is limited. “Rain flower bed“ can be established by plantingor sowing. Both having its pros and cons the combination of these two approaches is apparently best, because sowing allows reduce initial costs of new greenery, while planted perennials prevents erosion and operate as structural plants. Additionally 30 plant species were tested, whether they are usable for direct sowing. Experiment was established within the grant project IGA - ZF/2018 - AP001 on April 2018 in Mendeleum grounds of Faculty of Horticulture, Lednice. Preliminary results show low germination rates that are significantly dependent on climatic conditions. Of the 30 only six can recommend for now: Achillea ptarmica, Asclepias tuberosa, Cichorium intybus, Coreopsis lanceolata ´Sterntaller´, Phuopsis stylosa, Oenothera biennis. Better results can be probably achieved by sowing plants in autumn, however results of the autumn part of the experiment will be known after submission of this work.
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The influence of PEO source on nanofiber layer preparation
Grufíková, Jana ; Knotek,, Petr (referee) ; Knotková, Kateřina (advisor)
The electrospinning process of polymer solutions is affected by many different parameters that can be divided into solution parameters, process parameters, and ambient parameters. This study is focused on characteristics of a polymer and its solution, which are ranging into the solution parameters. The aim of this study is to compare poly(ethylene oxide) characteristics in the relation to electrospinning of hyaluronic acid, to find the difference between them using available analytic, thermic and spectral methods, and to define the influence of properties on polymeric solutions behavior during electrospinning. It was find that poly(ethylene oxides) obtained from two different sources behave differently in an electrostatic field, although their molar mass is declared as the same. It was also confirmed that the electrospinning process of polymeric solutions is affected mainly by their viscosity and conductivity. This two properties are determined especially by the molar mass of polymer and also by the content of impurities or content of some another polymer during electrospinning of mixed solution.
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Popularization of history at the example of Lidice and Terezin
Knotková, Kateřina ; Macků, Lucie (advisor) ; Zychová, Jana (referee)
The essence of bachelor thesis Popularization of history at the example of Lidice and Terezín is to define the methods of presentation and popularization of Lidice Memorial and Terezín Memorial. The aim of the theoretical framework is mainly to outline the topic of collective memory in it´s basic forms. The topic continues with definitions of collective memory products as are collective trauma and politics of memory. The separate chapter is dedicated to the bearers of memory among which are museums, memorials, books, movies and internet. Last part is focused on historical context. The purpose of the practical framework is to apply the theoretical base on the mentioned memorials and to analyze their activities, which are helping to popularize history. The thesis presents form and appearance of the both memorials Terezín and Lidice, their projects, education programs and also movie and book production.
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