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Nanotechnology in construction of sensors for detection of hydrogen
Macháčková, Marina ; Hrdý, Radim (referee) ; Hubálek, Jaromír (advisor)
Aligned arrays of nanostructures has recently attracted great interest because of their unique properties and potential use in a broad range of technological applications. The nanostructures can be employed when it is essential to create large surface on a small area in electronic device as sensor technology or energetics e.g. solar panels. One of the simplest and low-cost methods of fabricating nanostructures is template-assisted electrochemical deposition. This method also enables good control over the nanostructure dimensions and can be used to deposit a wide range of materials. The proposed method consists of two steps. At first, a non-conductive nanoporous template has to be created and then nanostructures are formed by electrodeposition into the template which is coated with a metal on one of its sides or placed on a metal surface.
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Lignite hydrocolloids
Macháčková, Mirka ; Taraba, Boleslav (referee) ; Pekař, Miloslav (advisor)
This diploma thesis deals with the study of non-energy use of lignite. The main objective was to find an optimal recipe for the preparation of liquid and semi-solid (paste) hydrocolloids from the South Moravian lignite using the planetary mill and select the suitable dispersion medium with emphasis on possible use in agriculture. The used solutions were 10, 20 a 40 % w/w solutions of urea; 5, 10 a 15 % w/w solutions of citric acid; 1, 5 a 10 % w/w solutions of potassium chloride and deionized water. The best weight ratio for the preparation of lignite hydrocolloids is 1 part of lignite and 2 parts of the solution. The next part of this work is the isolation of humic acid from lignite hydrocolloids. The weight of isolated humic acids and amount of ash were compared to the used lignite hydrocolloids. Rheological behavior, particle size distribution, stability and thermal stablity of prepared lignite hydrocolloids were investigated. Correlation microscopy was used for determining elemental composition of selected location in the sample of lignite hydrocolloid.
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Development of non-energy use of lignite
Macháčková, Mirka ; Sedláček, Petr (referee) ; Pekař, Miloslav (advisor)
This bachelor thesis deals with the study of non-energetic use of lignite. The use as a sorbent is one of many possibilities. Sorption of chloride and sodium ions was carried out on natural lignite from the South Moravian, lignite washed with deionized water and lignite enriched with calcium ions. The experiments were realized monitoring pH, electrical conductivity, amounts of sodium and chloride ions in the prepared samples. Chemical oxygen demand was determined in the extract of lignite. This measurement was carried out in accordance with norm ČSN 83 0540-8 Chemical and physical analysis of waste water: Determination of dichromate oxidability. For use in agriculture were investigating the possibility of preparation of humic hydrocolloids by high speed dispergator and planetary mill. The ideal ratio of lignite and water was determined. The liquid and solid humic hydrocolloids were prepared by mechanochemical activation the lignite. These were characterized - particle size, UV-VIS spectroscopy of prepared extracts and sedimentation.
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Impact of input parameters variation on fabrication of nanoporous alumina
Hriczo, Filip ; Macháčková, Marina (referee) ; Hrdý, Radim (advisor)
This thesis examines and tests acids and conditions, which make the production of nanoporous ceramic at the thin aluminium layer the most effective and provide the highest quality. This paper describes the production of nanoporous structures with pore size 15-400 nm, depending on the electrolyte. Creating a regular hexagonal structure by electrochemical oxidation is dependent on many parameters that affect the regularity of structure and parameters of the ceramics produced. They were investigated primarily by changes in temperature and input voltage. All results were examined by SEM analysis.
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Descriptor lists for irises, peonies and daylilies in the Průhonice Botanic Garden
Sekerka, Pavel ; Blažek, Milan ; Blažková, Uljana ; Caspers, Zuzana ; Macháčková, Markéta ; Fáberová, I. ; Papoušková, L. ; Matiska, P. ; Koudela, M.
In 2015, the Council of Plants Genetic Resources agreed to include genus Hemerocallis (daylily) and genus Paeonia (peony) into the collections of genetic resources of the National Program. In addition to the selection of plants suitable for the National Program, we started to prepare descriptor lists for these genera in cooperation with students of the Department of Horticulture Faculty of Agrobiology, Food and Natural Resources Czech University of Life Science, Prague. The descriptor list was supposed to cover botanical characteristics of wild species as well as the advanced garden ornamental varieties, because the species of peonies and daylilieas are medicinal plants and it is therefore appropriate to incorporate them in the National Program. At the same time, it turned out that the descriptor list used for Iris is intended primarily for bearded irises (Iris subgen. Iris). However, in the last twenty years, the Czech breeders have specialized also in other groups of irises, especially in Siberian and Japanese irises and Spuria group, which don’t have any beard on outer tepals and have other differerent characteristics from the subgenus Iris. Therefore, we have decided to extend the existing descriptor list to cover the whole genus except bulb irises.
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The Experience of Nonbinary Individuals with Self-Presentation and Gender Expression (from a Phenomenological Perspective)
Novotný, Ondřej ; Smetáčková, Irena (advisor) ; Macháčková, Marcela (referee)
This bachelor's thesis explores lived experiences of individuals who identify as non-binary, both in personal spheres and social interactions. It defines the concept of gender and examines related concepts such as its development, roles, stereotypes, and its socially constructed nature, as well as its interaction with social and personal identity. It briefly touches on androgyny and gender-aschematicity and their potential positive impact on society through reducing the salience of gender stereotypes, by promoting more flexible notions of gender. In the empirical section, the thesis analyses the narratives of four non- binary informants (obtained through semi-structured interviews) using interpretive phenomenological analysis. It specifically focuses on self-presentation and gender expression in relation to authenticity, studying the interaction between the self and the social environment. The thesis highlights the variability in experiences among these four individuals and summarizes their experiences into emergent themes and subthemes. Through description and interpretation, it seeks to elucidate and explain the individual experiences of the informants. Various common themes arise, such as: (1) the relationship between pressure exerted on the individual and the perceived need to challenge...
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Analysis of biologically active substances from medical mushrooms
Macháčková, Mirka ; Bendová, Agáta (referee) ; Hoová, Julie (advisor)
This bachelor thesis deals with the benefits of mushrooms for the human body and with the important substances that are contained in them and give them properties that cannot be found in any other natural food component in such a complex design. Specifically, the mushrooms discussed in the thesis belong to rare species of mushrooms, not only because of their rare occurrence in nature, but mainly because of their unmistakable positive properties. In the theoretical part of the thesis, the basic characteristics of fungi, structural features and basic division were described. Further, the theoretical part discusses the characteristics of individual rare mushrooms that were selected for further observation. It deals mainly with their occurrence, positive impact on the human body and their practical use. This section also deals with the chemical composition of mushrooms, specifically the contained and immunologically active substances. Last but not least, the theoretical part describes important microorganisms that were used in measuring antimicrobial activity in the practical part of this work. The practical part of the thesis was devoted to the preparation of mushroom extracts from reishi, shiitake, oyster mushroom and Judas ear mushrooms using three different solvents. It optimizes methods for the determination of nutritionally important substances by selecting appropriate solvents that were able to positively influence the yield when determining the mushroom content. It is also engaged in testing antioxidant activity, determination of content and antimicrobial activity. Based on these measurements, it was proved that all the above-mentioned active substances are present in different concentrations in the mushrooms studied. Mushroom powders or their extracts can subsequently be used alone as dietary supplements or as an additive to foods with low nutritional value.
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