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Monolayers of platinum nanoparticles prepared by dip-coating
Černohorský, Ondřej ; Grym, Jan ; Yatskiv, Roman ; Pham, V.H. ; Hudry, D. ; Dickerson, J.H.
Platinum is a transition metal known for its catalytic properties, which are further enhanced when employed in a nanoparticle form. We have recently shown that a monolayer of Pt nanoparticles deposited on semiconductor substrates forms high quality Schottky diodes, which were used in sensitive hydrogen sensors with a detection limit of 1 ppm of H-2 in N-2. Preparation of ordered monolayers of Pt nanoparticles is essential for the understanding of the behaviour of such an interface. To obtain a hexagonal closed-packed nanoparticle array, we prepared Pt nanoparticles stabilized by oleylamine and oleic acid with a narrow size distribution and uniform shapes. A monolayer prepared by dip-coating of Si substrate in the suspension containing Pt nanoparticles showed hexagonal arrangement within separate domains with the surface coverage up to 90%. The increase of the surface coverage with increasing withdrawal speed of the dip-coating process was observed
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THE INVESTIGATION OF AN Al7075 ALLOY PREPARED BY SPARK PLASMA SINTERING OF MILLED POWDERS
Molnárová, O. ; Málek, P. ; Nemeth, G. ; Kozlík, J. ; Lukáč, František ; Chráska, Tomáš ; Cinert, Jakub
Atomized powder of an Al7075 alloy was high energy ball milled at room and cryogenic temperatures and compacted by spark plasma sintering (SPS) method. The influence of processing parameters on phase composition and microstructure was studied by X-ray diffraction, light and scanning electron microscopy. The mechanical properties were characterized by microhardness measurements. The atomized powder contained a large volume fraction of intermetallic phases located predominantly in continuous layers separating cells or dendrites in the interior of individual powder particles. Consolidation by SPS destroyed partially this morphology and replaced it by individual particles located at boundaries of original powder particles, at cell boundaries or arranged in chains in previous dendritic regions. High energy milling destroyed most intermetallic particles and enriched the matrix by solute atoms. The high deformation energy introduced into the powder during milling enhanced microhardness up to 220 HV. Consolidation of milled powders by SPS led to the formation of very fine-grained structure with the grain size even below 1 μm and with the fraction of high-angle boundaries about 0.9. Two main types of heterogeneously distributed precipitates were found. The irregularly shaped precipitates with a size about 1 μm seemed to encompass areas with rod like nano-precipitates in most samples. A drop in microhardness to 118HV was observed after SPS, predominantly due to a release of introduced deformation energy.
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Monitoring and comparison of teaching athletics at elementary schools in the Czech Budejovice
SAJTL, Ondřej
The content of this thesis is monitoring and comparation of athletics education in basic schools in České Budějovice. Teoretical part includes the knowledge of health, fyzical activity, the importance of PE and athletics. We had made the questionare and according to this we found out the atributes of PE education in all schools. After that we made the spectrum which allowed us to compare all schools. The practical part is focused on data collection of each school. The result of individual questions and final results are shown in charts at the end.
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An impact of organic farming on soil quality
Matěchová, Martina ; Jakšík, Ondřej (advisor) ; Janků, Jaroslava (referee)
This work focuses on the system of organic agriculture and its impact on soil quality. It compares organic farming system with conventional. Both these systems are briefly described. There is also a list of soil quality indicators used for the soil quality is evaluation. The results of scientific studies, which dealt with different farming systems and their effects on soil properties, were discussed and evaluated.
Quality and fertile soil is crucial for production systems, however to define what means quality soil is very difficult. Therefore the number of quality indicators were established. The indicators can be grouped by their nature of soil properties they assess, such as physical, chemical and biological. Different techniques are adopted for soil quality evaluation.
Soil quality is affected by a lot of different factors. Anthropogenic activities are often considered as one of the most influential factor. The loss of soil fertility as well as other physical, chemical or biological deterioration of soil properties is called soil degradation.
The results of this study shown that careful tillage in organic farming could have positive effect or no effect on the biological and physical properties of soils. For some experiments there was an increased amount of soil organisms.
In the most experiments, application of organic fertilizers caused increase of organic matter and other essential nutrients. We conclude that under certain conditions with respect for the principles of organic farming the soil quality can be preserved or even improved, but in a longer timeframe.
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Synthesis of novel cytostatic deazapurine nucleosides and pronucleotides
Perlíková, Pavla ; Hocek, Michal (advisor) ; Jindřich, Jindřich (referee) ; Hlaváč, Jan (referee)
The synthetic routes to three types of phosphate prodrugs of 6-hetaryl-7-deazapurine ribonucleosides based on palladium-catalyzed cross-coupling reactions have been developed. CycloSal- and phosphoramidate pronucleotides and octadecyl phosphates derived from 6- hetaryl-7-deazapurine ribonucleosides were screened for their in vitro cytostatic activity. It was shown that cytostatic activity of cycloSal phosphates was similar or slightly lower compared to the parent nucleosides. Significant drop of cytostatic activity was observed in phosphoramidate pronucleotides. Octadecyl phosphates were devoid of any cytostatic activity. 6-Hetaryl-7-deazapurine ribonucleosides with bulky groups in position 6 showed very strong and selective inhibition of adenosine kinase from Mycobacterium tuberculosis. 2'-Modified 6-hetaryl-7-deazapurine nucleosides: 2'-O-methylribonucleosides, arabinonucleosides and 2'- deoxy-2'-fluororibonucleosides, were prepared by multistep functional group transformations from a ribonucleoside. The synthesis of 2'-deoxy-2',2'-difluoro-erythro-pentofuranosyl nucleosides was based on a glycosylation of 6-chloro-7-deazapurine with a sugar synthon followed by palladium-catalyzed cross-coupling reaction and deprotection. Despite the low yields and laborious separation of the anomers,...
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Sensory quality of chosen types of beer
Lišková, Michaela ; Divišová, Radka (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with the sensory guality of chosen types of beer. The teoretical part was focused on the production of malt and beer and raw materials needed and also an introduction to sensory analysis was described. The experimental part was focused on evaluation itself. Nineteen untrained assesors were invited for sensory evaluation, who evaluated five selected beer kinds using the preprepared form. Unstructured graphic scale with a verbal description of anchor points was used to evaluate the appearance and color, taste and odour, fullness, bite, foaming, bitterness and any off-taste or off-odour of each sample. Five-point category ordinal scale was used for assessment of the overal acceptability of the samples. Results of the analysis were then evaluated graphically and statistically.
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Gender stereotypes from teachers' approach to students at the Grammar School.
Mrůzková, Helena ; Havelková, Hana (advisor) ; Smetáčková, Irena (referee)
Gender stereotypes exist in society at large, and in the education system in particular. These stereotypes show the male as the dominant person, who works outside the home in often prestigious occupations. The female is usually showed as being subordinate and confined to the home. Moreover, these stereotypes give the fact that females choose predominantly humanistic and domestic sciences, while males choose science and technology. In my dissertation I analyze gender stereotypes that are in teachers' minds at the Grammar School. Eight teachers participated in this research, in eight different classes. The research is separated into three basic parts: videotyping of lessons and their analyze, the self-reflection from teachers and finally, individual interwiev between researcher and respondent that is also analysed in the name of gender stereotypes. The aim of my research is to analyze gender stereotypes from teachers to students with aspect of different access to girls and boys.
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Epididymal maturation – a crucial step in the post-testicular sperm development
Postlerová, Pavla ; Pohlová, Alžběta ; Zigo, Michal ; Jonáková, Věra
Mammalian spermatozoa after their development in testis undergo the post-testicular maturation in epididymis where acquire their fertilization ability and competence of movement. The epididymis is tissue with very active fluid-absorbing and fluid-secreting activity. Epididymal fluid contains ions and small molecules, proteins, glycoproteins and enzymes. The surface of spermatozoa is exposed directly to the epididymal fluid, and the sperm plasma membrane is significantly changed. Some testicular proteins are altered, masked, or replaced by new proteins/glycoproteins of epididymal origin. Several proteins produced by epididymis have been described in various mammalian species and shown to be associated with spermatozoa suggesting a role in the sperm maturation and/or sperm-egg binding and fusion. We isolated proteins from fluid, tissue and sperm of boar epididymis, and separated them by chromatographic and electrophoretic methods. We searched for known proteins using panel of antibodies and tested proteins of epididymal fluid for binding abilities. In the epididymis, we found proteins described as proteins of seminal plasma and associated with the sperm surface, such as spermadhesins, beta-microseminoprotein and acrosin inhibitor. These proteins were detected in epididymal sperm, fluid and tissue. We showed that some epididymal proteins may bind the spermatozoa and change the binding sites on the sperm surface. We determined and identified some proteins from boar epididymal fluid with affinity to heparin, hyaluronan and zona pellucida glycoproteins. These phenomena indicate that epididymal fluid proteins bind to the sperm surface during epididymal maturation and might subsequently play role in the sperm capacitation or sperm-zona pellucida binding.
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Personal and social development through dramatic improvisation
Gabrielová, Vanda ; Froněk, Jan (advisor) ; Raisová, Tereza (referee)
The author focuses in her work on the importance and possibilities of dramatic improvisation in the social-personal development of adults. She points out principles and rules of this method, which can help in the development of each person's potential. Subsequently, she concentrates especially on themes like barrier outdoing, self-confidence, single-mindedness, fantasy, emotion control, acting skills and the art of dialog. Furthermore, in the preparation and implementation of courses she emphasizes principles and methods in accordance with the didactic cycle C-M-I-A-R-E. Author presents requirements for instructors as well as overall organization of those courses. In conclusion, model exercises, which can be faced by participants of dramatic improvisation, are shown. Author then explains their purposes and analyzes them step by step.
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Valuation of PEBAL s.r.o.
Turza, Vladimír ; Brabenec, Tomáš (advisor) ; Keselý, Ladislav (referee)
The thesis aims to determine the equity value of the company PEBAL s. r. o. as of January 1st 2016. It is not separated into theoretical and practical part, because it is considered as fake appraisal of an expert. That is the reason why the whole thesis is practical with occasional theoretical background explanations. In the first part there is basic information provided about the appraised company along with its characteristics. Then financial analysis is carried out which will provide an overall picture of financial health of the company along with determination of competitors. Followed by strategical analysis which deals with the market as whole and predicts its future development as well as development of sales of the valued company. The next part consists of analysing and predicting value drivers and the overall financial plan. Result of the last part is the valuation itself applying discounted cash flow (DCF) method using discounts rate calculated earlier in the chapter. The final chapter also contains market valuation using method of comparable companies along with Monte Carlo simulation, that provides probability distribution of the value of the company.
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