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Photobiological safety evaluation of light sources for household use
Jelínek, Jakub ; Motyčka, Martin (referee) ; Štěpánek, Jaroslav (advisor)
This thesis deals with the photobiological safety of light sources used for household lighting. The theoretical part of the thesis is devoted to areas related to photobiological safety, such as the basic description of vision functions, the description of light sources, as well as methods of measurement and evaluation. In the practical part, the spectrum of individual light sources is measured, from which the irradiance limits are calculated, according to which the source is assigned to the appropriate group of hazards.
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Effects of climatic conditions on the properties of butadiene oligomers
Baťa, David ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
The bachelor thesis is conversant of monitoring dielectric material properties in AC electric field. The electrical properties of variety liquid oligobutadiens includes are studying in their practical applications. Experimentally there are verified and analyzed influences of the climatic factors especially temperature and ultraviolet radiation on the frequency dependencies of complex permittivity parts with respect to present various functional groups in oligobutadiene chains.
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Methods of assessing the increase in the durability of concrete products with a painted surface with a subsequent cure
Minaříková, Kateřina ; Eger, Lukáš (referee) ; Hubáček, Adam (advisor)
This diploma thesis is focused on the description and summary of existing knowledge about vibro-pressed concrete products with treated surface with protective coating, that is hardering by ultravioled and infrared radiation. The theoretical part describes the production of vibro-presses products, possible wayt of finishing the surface including the description of the most commonly used materials and the methods of application and hardering of protrctive coating on the surface. Another point of the theoretical part is creating of lime efflorescence on the concrete surface and their subsequent disappearance. The experimental part of the thesis is ficused on obtaining information about the properties of the modified pavements by these techologies and comparing the acquired properties with the charakteristice of the reference pavements that do not have any protective coating on their surface.
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Possibilities of increasing the durability of concrete products based technologies hardening their surface
Minaříková, Kateřina ; Eger, Lukáš (referee) ; Hubáček, Adam (advisor)
In the last years, we focus on higher quality of surfaces in the field of vibro-pressed concrete products. Therefore, there are products with specially modified backing layer in the market where there is implemented impregnation coating on the surface that is cured by ultraviolet and infrared radiation. The primary objective of my thesis is summary of the existing knowledge about vibro-pressed concrete products that are modified by these technologies. I will especially focus on description and efficiency of using particular methods, principals of curing surfaces and other modification of concrete product’s surfaces with emphasis on its durability. There will be examined in the laboratory conditions some of the characteristics of these vibro-pressed concrete products as resistance of surfaces against water effects and chemical defrosting substances, water absorption of surfaces, abrasion resistance, slip resistance, as well as risk reduction of creating lime efflorescence on the concrete surfaces.
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Analysis of degradation mechanisms oligobutadienes
Baťa, David ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This work deals with the studies of liquid oligobutadiens properties in AC electric field by dielectric relaxation spectroscopy method. The current issue in the diagnosis of oligomeric and polymeric materials during the activity of various degradation factors and options of their alleviation and suppression was studied. The existing apparatus is modified for monitoring possibilities of polymeric materials during the action of various degradation and operational factors. Effect of climatic factors are experimentally investigated, especially UV radiation and temperature on the course of the frequency dependence of complex permittivity components with respect to the different composition and length of the polymer chain.
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Power supply for medium pressure UV lamps
Hurdálek, Tomáš ; Zemánek, Miroslav (referee) ; Boušek, Jaroslav (advisor)
UV radiation has a very wide range of uses in industrial production and disinfection. At present, medium-pressure mercury lamps are used for the reliable generation of UV radiation. The aim of this work is to get acquainted with the principle of individual types of lamps and methods of controlling their power and to design an electronic ballast with continuous power control and, if necessary, verify the correct function of its most important parts.
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Assessing the impact of the closing of paint and lacquer surfaces on the durability of concrete products
Zubkova, Ekaterina ; Eger, Lukáš (referee) ; Hubáček, Adam (advisor)
This diploma thesis is focused on studying the influence of different types of surface treatments on vibropressed product. The main goal is to characterize surface treatments consisting of application of surface coatings that are hardened by infrared or ultraviolet radiation. Theoretical part gives specifications already known methods for surface finishing. Briefly describes selected types of prefabricated concrete parts and specificate the requirements for these products. It also describes used test methods. The experimental part was aimed at establishing the effectiveness of changing properties concrete products by adding coatings on their surface. This was achieved by testing the properties of concrete paving blocks with modified surfaces and testing of reference blocks that did not have any surface treatment followed by mutual comparison of the results.
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Study of properties of Fiber-Reinforced Polymers
Fojtášek, Martin ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
Bachelor thesis deals with monitoring the properties of the FRP reinforcement when exposed to aggressive environments that cause degradation. In the theoretical part of this thesis there are described the method of production, the most commonly used types of FRP profiles, the composition of the FRP profiles, durability of FRP profiles against the action of aggressive environment and durability of the FRP material in the damage environment. Further more there are briefly described the most common types of tests on FRP profiles. In the experimental part of this thesis there are defined conditions for laboratory testing of FRP samples, which were stored in an alkaline environment at temperatures of 20 degrees, 40 degrees and 60 degrees. These samples of the FRP were stored and tested after 90 days. Subsequently there are described the changes of the physical properties of rebar in a time when saving in an aggressive environment.
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Photobiological safety of light sources and lighting systems
Štěpánek, Jaroslav ; Krbal, Michal (referee) ; Škoda, Jan (advisor)
The thesis deals with the problems of the photobiological lamp and lamps systems safety. It is divided into theoretical and practical parts. The theoretical part touches the basic knowledge concerning the eye and vision, eye and skin diseases caused by excessive exposure to non-ionizing radiation. And besides that there are described the sources of light causing the possible exposure and further more it includes the methodology of measurement and evaluation of photobiological safety. The practical part investigates a measurement of the spectrum of light sources. The measured data are evaluated according to the methods mentioned in the theoretical part.
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Pattern as a functional trait, case study on Mallomonas chrysophytes
Knotek, Petr ; Němcová, Yvonne (advisor) ; Rychtecký, Pavel (referee)
The patterns that can be admired on the surface of many living creatures are also found in many microscopic organisms outside of the macroscopic world we are familiar with. However, their significance and function are yet little understood compared to those of the macroscopic world. In diatoms (Bacillariophyceae) and coccoliths (Haptophyceae), several hypotheses have already been developed concerning the function of their patterned shells. One hypothesis considers the shell as a photonic entity that could reflect UV radiation away from the cell. Others focus more on its mechanical properties, which are among the most impressive within biological structures. Silica-scaled chrysophytes (Synurales, Stramenopiles) also possess a complex shell (or scale-case). Cells are covered with scales (about 4 µm in size) that are very regularly arranged and form a siliceous scale-case on the surface. The pattern on the scales is species-specific and has undergone gradual modification during evolution. This work aims to assess whether the patterning of siliceous scales in the order Synurales can be considered a functional trait or it is a result of neutral evolution. To test the possible photonic properties of the patterned structures, a pair of growth experiments were performed. The experimental cultures were...
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