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The effect of stress on astrocytes and their function during brain development in adolescence
Veverka, Jakub ; Nekovářová, Tereza (advisor) ; Telenský, Petr (referee)
Astrocytes have perhaps been historically underestimated in their number of roles regarding brain homeostasis. Recent studies are identifying the pivotal role they play in brain restructuring and how possible disruption of their function could be a predisposing factor for numerous psychiatric diseases. Proper astrocytic function might be of increased significance in adolescence, when major heterochronic brain restructuring occurs, and external stressors are of magnified effect. Regarding the role of astrocytes in synaptic formation/degradation and synaptic cleft substance clearance, the dysfunction of their homeostatic pathways during such a crucial period may predispose the effected person to specific patterns of CNS development. This could prove to be important during the development or progression of psychiatric and psychological disorders. This work will focus on the role of astrocytes during pathologically stressful conditions, the alteration of their function and the researched causes for such events namely during the unique time period of adolescence. It will also comment on the possible effect of such events during adolescence on the appearance or progression of potential psychiatric or psychological disorders later in life. Key words: Astrocytes, stress, brain, adolescence, development
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Business Plan for New Enterprise
Nováková, Ivana ; Veverka, Jakub (referee) ; Khateb, Fabian (advisor)
The Master‘s thesis deals with processing of business plan of Florist's in Brankovice. The theoretical part describes the theoretical background needed to develop the business plan. The practical part includes marketing research, analysis of the interal and external enviroment and draft of the business plan.
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Powder feeding analysis in RF-ICP
Zlatník, Rostislav ; Veverka, Jakub (referee) ; Čížek, Jan (advisor)
The work is focused on the problematics of inductively coupled plasma, which is used for deposition of layers. We focused on two goals in the work. The first one focused on powder feeder, which is working on the vibration principle and is used in an apparatus that is using inductively coupled plasma. The aim is to determine its properties, dependence on different input parameters and working conditions. Is important to verify the suitability of its use for this kind of application. The assumption was to find the ideal configuration of the feeder for the given powder. After an overall assessment of the feeder properties, it was recognized as inappropriate for this application. The second goal is to spray tungsten layers with three different tungsten powders. Layers made with an inductively coupled plasma technology delivers promising results, but this issue needs to be intensively addressed in the future.
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Disintegration of sludge thickened by flotation
Veverka, Jakub ; Jecha, David (referee) ; Houdková, Lucie (advisor)
The main topic of this thesis is a research of influence of disintegration of sewage sludge on the production of biogas during the process of anaerobic fermentation. The theoretical part deals with issues and specific methods used during the process of waste water cleaning, furthermore it contains simplified description of waste water treatment plants and particular devices. The number of ways of processing sewage sludge and its potential utilization id also discussed. Following parts of the thesis analyze in detail my own process of anaerobic fermentation including important factors influencing this process. Comparison of aerobic and anaerobic fermentation and ecological perspective on the issue are included in this part. Another important part of the thesis deals with disintegration and description of the disintegration methods and devices. The fundamental part implies the analysis of the executed experiments. Experiments analyze the growth of biogas during anaerobic fermentation depending on the disintegration of sewage sludge. After that the evaluation of the experiments is stated together with economical calculations of the disintegration process executed in laboratory conditions.
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Domestic heat pump
Veverka, Jakub ; Joch, Lukáš (referee) ; Pospíšil, Jiří (advisor)
The aim of the Bachelor's thesis is the ,,Heat pumps and house heating " . The thesis is divided into four main parts. The first part briefly describes the principle of operation and the types of heat pumps (The variants are water to water, air to water, earth to water), including the advantages and disadvantages of their use. Heat pumps are effective solutions to home and hot water heating. The part describes the heat transfer between the condenser and the heating pipes. The second part includes a proposal for using the specific heat pump, a brief description of the selected object and calculate the heat loss. The third part pays attention to calculating the energy performance of buildings. Economic evaluation of the selected system and financial returns are contained in the fourth part of this work.
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Tungsten-steel and tungsten-chromium composites prepared by RF plasma spraying
Matějíček, Jiří ; Klečka, Jakub ; Čížek, Jan ; Veverka, Jakub ; Vilémová, Monika ; Chráska, Tomáš ; Ganesh, V.
For future fusion reactors, materials able to withstand harsh environments are needed. In particular, this concerns the plasma-facing components which are foreseen to consist of tungsten based plasma-facing armor and structural and cooling part made of steel. Currently, joining of these materials presents a significant challenge. The stress concentration at their interface, which arises due to thermal exposure and the difference in thermal and mechanical properties, can be reduced by composite/graded interlayers. Plasma spraying is among the prospective technologies for their preparation. In this work, tungsten-steel and tungsten-chromium composites were prepared by radio-frequency inductively coupled plasma (RF-ICP) spraying. Initial optimization of the spraying process for pure materials as well as their mixtures was carried out. Basic characterization of the layers for their structure, porosity and composition is presented.
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Thin nitride layers as permeation barriers
Veverka, Jakub ; Matějíček, Jiří ; Lukáč, František ; Pospíšil, D. ; Cvrček, L. ; Nemanič, V.
Permeation barriers represent one of the crucial fields in materials development for thermonuclear fusion. Primary objective of the barriers is to suppress the permeation of hydrogen isotopes (mainly tritium) from future thermonuclear fusion facilities. Secondary objective is to reduce their retention in structural materials. Expected reactor conditions put high demands on the material, as well as on the final barrier quality. Key properties are tritium permeation reduction, absence of defects (especially cracks), high-temperature stability and corrossion resistance, and compatibility with structural materials (mostly ferritic-martensitic steels). Thin nitride layers, identified as promising permeation barriers, were prepared by diffusion-based nitridation and physical vapour deposition (PVD), and characterized.
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Powder feeding analysis in RF-ICP
Zlatník, Rostislav ; Veverka, Jakub (referee) ; Čížek, Jan (advisor)
The work is focused on the problematics of inductively coupled plasma, which is used for deposition of layers. We focused on two goals in the work. The first one focused on powder feeder, which is working on the vibration principle and is used in an apparatus that is using inductively coupled plasma. The aim is to determine its properties, dependence on different input parameters and working conditions. Is important to verify the suitability of its use for this kind of application. The assumption was to find the ideal configuration of the feeder for the given powder. After an overall assessment of the feeder properties, it was recognized as inappropriate for this application. The second goal is to spray tungsten layers with three different tungsten powders. Layers made with an inductively coupled plasma technology delivers promising results, but this issue needs to be intensively addressed in the future.
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Alternative Methods of Permeation Barriers Preparation
Veverka, Jakub ; Matějíček, Jiří
Permeation barriers represent one of the crucial fields in materials development for thermonuclear fusion. Primary objective of the barriers is to suppress the permeation of hydrogen isotopes (mainly tritium) from future thermonuclear fusion facilities. Secondary objective is to reduce their retention in structural materials. Expected reactor conditions put high demands on the material, as well as on the final barrier quality. Key properties are tritium permeation reduction, absence of defects (especially cracks), high-temperature stability and corrossion resistance, and compatibility with structural materials (mostly ferritic-martensitic steels). Thin nitride layers, identified as promising permeation barriers, were prepared by diffusion-based nitridation and physical vapour deposition (PVD), and characterized.
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Disintegration of sludge thickened by flotation
Veverka, Jakub ; Jecha, David (referee) ; Houdková, Lucie (advisor)
The main topic of this thesis is a research of influence of disintegration of sewage sludge on the production of biogas during the process of anaerobic fermentation. The theoretical part deals with issues and specific methods used during the process of waste water cleaning, furthermore it contains simplified description of waste water treatment plants and particular devices. The number of ways of processing sewage sludge and its potential utilization id also discussed. Following parts of the thesis analyze in detail my own process of anaerobic fermentation including important factors influencing this process. Comparison of aerobic and anaerobic fermentation and ecological perspective on the issue are included in this part. Another important part of the thesis deals with disintegration and description of the disintegration methods and devices. The fundamental part implies the analysis of the executed experiments. Experiments analyze the growth of biogas during anaerobic fermentation depending on the disintegration of sewage sludge. After that the evaluation of the experiments is stated together with economical calculations of the disintegration process executed in laboratory conditions.
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