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Fate of micropollutants during vermicomposting
Grasserová, Alena ; Cajthaml, Tomáš (advisor) ; Macek, Tomáš (referee) ; Lhotský, Ondřej (referee)
Vermicomposting is recently becoming a rather popular environmentally friendly technique for stabilizing biowaste, including sewage sludge. There is an effort to utilize the sewage sludge as fertilizer on agricultural land. But apart from nutrients, the sludge also contains harmful pollutants, which subsequently after its deposition on fields can be taken up by plants and organisms contaminating the food chains. Micropollutants, the substances that can be found throughout the environment in trace concentrations, are one of the pollutants occurring in sludge. It is for example pharmaceuticals and personal care products, per- and polyfluoroalkyl substances, or pesticides. Their negative effects are known - they can be for instance endocrine disruption, antibiotic resistance, or the development of cancer. Although the deposition of sewage sludge on fields as a fertilizer is one of the main introduction routes of micropollutants to the environment, the content of micropollutants before deposition is not monitored nor regulated. This dissertation focuses on the fate of micropollutants during vermicomposting, especially in sewage sludge substrates. The vermicomposting method was applied to stabilize coffee spent grounds and sewage sludge obtained from distinct wastewater treatment plants mixed with...
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Belt conveyor for recycle aggregate
Macek, Tomáš ; Škopán, Miroslav (referee) ; Malášek, Jiří (advisor)
This work deals with design of belt conveyor for transport of recycled aggregate. The first part of the work thesis describes the belt conveyor and gives an overview of manufacturers of belt conveyors. In the next part there is a functional calculation according to ISO ČSN 5048 is performed from the specified parameters, which are the length of the conveyor, the height difference and transport performance. Further, there is the design of the individual components of the belt conveyor is made. In the last part, there is the strength control of the driven drum and the driven drum axis is performed. Work is completed with drawing documentation.
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Design of pneumatic cylinder testing equipment
Macek, Tomáš ; Pavlík, Jan (referee) ; Tůma, Zdeněk (advisor)
This diploma thesis deals with the design of test equipment for selected types of pneumatic cylinders. In the first, theoretical, part of the work is an analysis of the current state of knowledge in the field of pneumatic cylinders. Furthermore, the problems in the field of measurement and testing of pneumatic components are described here, selected linear position sensors are also described herein too. The second, practical, part deals with the choice of a suitable design variant and the actual solution of the test equipment design. A pneumatic circuit is also designed here. Part of the work is a 3D model of the test equipment and drawing documentation. The conclusion of the work is devoted to the overall evaluation of the work and recommendations for practice.
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Log-optimal approach in betting, compound events
Macek, Tomáš ; Kupsa, Michal (advisor) ; Večeř, Jan (referee)
In this Thesis we deal with the log-optimal betting approach. The goal is to maximize the gambler's wealth in the long term. In the course of the Thesis, we will work our way from the basic cases to a completely general problem, while the task is always to obtain a log-optimal betting strategy. For the simplest cases, we use the connection to information theory, and for others we will formulate and prove a version of the Karush-Kuhn-Tucker conditions suitable precisely for the log-optimal betting aproach. In this work, we focus primarily on the tree betting scheme and we will derive the algorithm for obtaining the log-optimal strategy of any betting opportunity from the tree betting scheme, which co- vers a large variety of betting opportunities. We will then use this algorithm to program an application in Python, which will print out the log-optimal strategy of a given betting opportunity to the user. Finally, we will verify that the obtained results correspond to the Kelly criterion and we will show several examples of the use of the Thesis. 1
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The Psychological Aspects of Navigation of the Blind
Franc, Jakub ; Kebza, Vladimír (advisor) ; Horáková Hoskovcová, Simona (referee) ; Macek, Tomáš (referee)
This dissertation thesis addresses the area of spatial navigation of the blind. The author theoretically deals with a complex interplay of psychological functions involved in spatial navigation with respect to the specific conditions of the blind. The empirical part of the thesis presents an experimental study in the population of the blind (N=44). This study focuses on effects of the stress recovery phase from shortly increased stress levels on the process of learning a new route. The experiment is placed in real-world settings and overcomes some of the methodological flaws typical for this research domain. The research evidence suggests that the recovery phase from shortly increased stress levels hinders the development of procedural knowledge of the route. However, this deterioration in route knowledge is not associated with the effects of the strsss phase itself, but affects only the recovery phase part of the route in which stress levels are returning to their original baseline levels (not necessarily the level of the resting conditions). Besides its theoretical conclusions, the value of the presented thesis is in its contribution to the advancements of research methods in the given field. The outcomes of this work are practically applicable to the development of navigation aids for the blind....
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Structure and biocatalytic properties of nitrilases from filamentous fungi
Křenková, Alena ; Martínková, Ludmila (advisor) ; Macek, Tomáš (referee) ; Klempier, Norbert (referee)
Filamentous fungi are alongside bacteria a rich source of nitrilases that can be used for biotechnological purposes. There is a large number of sequences of putative nitrilases in databases, but few of these enzymes have been expressed, purified and characterized. According to the sequences in GenBank database, synthetic genes of putative nitrilases from Aspergillus niger CBS 513.88 and Neurospora crassa OR74A were designed, expressed in Escherichia coli and the nitrilases produced were purified and characterized. The effect of chaperone-assisted nitrilase expression was also examined using a set of commercial chaperone plasmids. The structural properties of nitrilases were examined using various methods, such as homology modelling, sedimentation velocity analysis or electron microscopy. Recombinant nitrilase production was compared to their production by native producers - filamentous fungi. The cultivation of native producers was rather difficult and nitrilase production was very low, therefore, the advantage of using prokaryotic expression system was highlighted. Nitrilases with amino acids close to the catalytic cysteine replaced were prepared in order to study the effects of certain amino acids on the activity, chemoselectivity and enantioselectivity of nitrilases. The catalytic properties of...
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Fungal Biodegradation of Endocrine Disruptors
Křesinová, Zdena ; Cajthaml, Tomáš (advisor) ; Macek, Tomáš (referee) ; Smrček, Stanislav (referee)
This dissertation thesis contains scientific results attained in the field of bioremediation. The major part of the results has been published in international journals in 7 papers. In addition, relevant yet unpublished results have been included too. The first thematic part describes the screening of the degradation ability of white rot fungi (WRF). In the screening, several endocrine-disrupting compounds (EDs; bisphenol A, triclosan, 4-nonylphenol and 17α-ethinylestradiol) were degraded by 8 different fungal strains in the presence of liquid medium. The most promising strains were used for the degradation of an ED mixture (synthetic and natural estrogens) in the presence of a straw substrate. Attention was paid to the evaluation of stimulation or suppression of enzyme activities during the biodegradation processes and changes in residual estrogenic activity. Pleurotus ostreatus, Irpex lacteus and Trametes versicolor showed the highest degradation ability under both cultivation conditions. On the contrary, Phanerochaete chrysosporium, to date the most studied representative of white rot fungi, did not degrade bisphenol A and 17α-ethinylestradiol (EE2) at all. Two review articles have been published to summarize the origin, presence and biodegradation of EDs, mainly EE2, in the environment. The...
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Mechanism of microbial biodegradation of polychlorinated biphenyls
Šrédlová, Kamila ; Cajthaml, Tomáš (advisor) ; Kočí, Vladimír (referee) ; Macek, Tomáš (referee)
Polychlorinated biphenyls (PCBs) are chlorinated organic compounds, which belong to persistent organic pollutants and exhibit various modes of toxic action, including mutagenicity, carcinogenicity, and endocrine disruption. PCBs were manufactured during the 20th century in many countries and extensively used due to their advantageous physicochemical properties. PCBs mostly served as insulating liquids in electrical equipment; however, they were also utilized in many open applications. Despite the worldwide ban on PCB manufacture imposed at the end of the 20th century, the contamination of the environment persists to this day as a result of their recalcitrance. Moreover, PCBs are still being inadvertently produced during many industrial activities. Because of their stability, the breakdown of PCBs in nature is extremely slow. This dissertation thesis focuses on the study of PCB biodegradation by ligninolytic fungi. This group of microorganisms belongs to the most promising, especially in regard to the degradation of organic pollutants. The biodegradation mechanism of PCBs was studied in vitro, including the identification of degradation intermediates. Laccase, an enzyme expressed by the oyster mushroom (strain Pleurotus ostreatus 3004), was able to degrade hydroxylated PCBs. In addition, chlorinated...
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