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Influence of deposits on algae growth in a tubular photobioreactor
Vajaýová, Veronika ; Lošák, Pavel (referee) ; Naď, Martin (advisor)
The content of the theoretical part of this bachelor thesis is a description of the tubular pho-tobioreactors, comparison of the individual types of the cultivation devices, the fundamental parameters influencing the efficiency of biomass production, and problems of formation of deposits on the inner surface of the photobioreactor. The attention is focused on the effect of sediment formation on the growth of microalgae in the tubular photobioreactor. Since the sediments affect the resulting light intensity in the suspension in the tubes, this phenomenon is reflected in the overall cultivation efficiency and the biomass yield. The practical part presents the course of measurements performed in the vertical tubular photobioreactor designed for flue gas cleaning using the microalgae Chlorella pyrenoidos Chick (IPPAS C2). The aim was to solve the problem of foaming, which subsequently caused deposits in the system's tubes or other parts. To this end, two measures were tested: • the mechanical one in the form of a wire mesh, • the chemical one using sunflower oil. The measured values were the basis for determining the effect of deposits on light intensity and also served to evaluate the functionality of the tested measures.
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Impact of habitat type and long-term in vitro cultivation on photosynthetic characteristics of snow algae and their resistance to stress induced by UV radiation
Zázvorková, Michaela ; Nedbalová, Linda (advisor) ; Kvíderová, Jana (referee)
Snow algae are psychrophilic microorganisms, that inhabit snow fields in mountains and polar regions, which creates colored snow in good conditions. Most species belong to order Chlamydomonadales (Chlorophyta) with complicated life cycles, containing flagellates and immobile stages (cysts). Extreme environment of snow is characteristed by low temperature, problems with availability of water and lack of nutrition. Depending on location and phase of life cycle, snow algae have to deal with excess or lack of solar radiation, the important component of which is also dangerous UV radiation. The light conditions differ substantially from open location above the forest level or polar regions to forest habitats. In the first part of this work I compared reactions of photosynthetic apparatus of snow algae strains from forest and forestless habitats to different intensity of radiation, then I dealt with assessing any changes related to long-term cultivation in laboratory. Based on measurement of rapid light curves on PAM fluorometer I have determined some characteristics of photosynthetic apparatus of individual strains (parameters α and Ik), which indicate adaptation to low or high light intensity. For some strains, it was possible to compare the results obtained at a three-year interval. In the second part...
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Changes In Properties Of Perovskite Solar
Cells During Their Lifetime
Dvořák, Tomáš
This paper deals with the problematics of perovskite solar cells, which can be the next generation of photovoltaic solar cells. The objectives of this research are to analyse changes in perovskite solar cells. For measurements of electrical properties were used various methods such as I-V characteristic, intensity modulated photovoltage spectroscopy and dependence of photocurrent on light intensity. Measurements indicate considerable changes of performance, which resulted from aging of perovskite solar cells. Results suggest deeper observation of perovskite solar cells.
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Influence of experimental conditions on hatching of diapausing stages of the cladoceran Daphnia obtusa
Sailerová, Martina ; Petrusek, Adam (advisor) ; Vaníčková, Ivana (referee)
Diapause is often an adaptation for survival during periods of harsh environmental conditions. Some diapausing stages do not terminate the dormancy once the favourable conditions are restored. Such prolonged diapause may be enforced by environment if a diapausing stage cannot be reached by the cues inducing termination of dormancy. However, it may also be an advantageous bet-hedging strategy to allow only a fraction of dormant stages produced in any given season to hatch the next time conditions become favourable. I tested whether such strategy can be observed in hatching patterns of dormant eggs of Daphnia obtusa - a cladoceran occurring in small Central European temporary waters. I investigated the influence of intensity of illumination on hatching success, and effect of isolating the eggs encased in ephippia from the sediment. Fraction of eggs terminating diapause, fraction of embryos successfully leaving the egg membranes, and timing of the response were assessed at 15 ˚C under four intensities of illumination (100% = 35µmol.m2 .s-1 , 75%, 50%, 25%; photoperiod 12h light: 12h dark) and in complete darkness for 21 days. My results support previous suggestions that there is no genetically-fixed bet-hedging strategy in D. obtusa. I observed high proportion of eggs which terminated diapause in all...
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Datalogger
Štupák, Branislav ; Bejček, Ludvík (referee) ; Beneš, Petr (advisor)
The bachelor thesis deals with the datalogger development for monitoring roof constructions ambients of historical buildings. The device is made of microcontroller ATmega328P and is using simple principles of environment monitoring. The device saves measured data to SD card from air temperature, air humidity, light intensity, wood moisture and air flow sensors. In conclusion of the thesis are then succesfully tested and summarized the properties of designed datalogger’s sensors.
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Methods for evaluation of quality of automotive filters
Sedlák, Jiří ; Drexler, Petr (referee) ; Mikulka, Jan (advisor)
This bachelor thesis deals with theoretical research, description and design of three individual methods of defective air filters detection. Individual methods are described and compared in terms of their technical difficulty and expected efficiency. These methods are optical test, acoustic test, pressure test and the method of detection of gas CO2. All researched methods were proved practically and the measurements of detection of defective air filters were taken. The defect of air filter was detected by use of optical test.
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Efficient Computation of Lighting
Kubovčík, Tomáš ; Pečiva, Jan (referee) ; Milet, Tomáš (advisor)
This bachelor's thesis deals with efficient computation of lighting in graphics scenes containing many light sources. Basic lighting calculation techniques as well as techniques derived from them will be introduced. The main goal of this thesis is to investigate tiled shading and its optimalizations described more in detail in both theoretical and practical sections. Concluding part consists of experiments performed on this techniques measuring their efficiency as well as implementation details of some interesting or important parts of them.
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The Lighting Equipment Used in Modern Vehicles and the Measurement of the Range of Visibility of the Main Headlights
Martínek, Michal ; Kropáč, František (referee) ; Vémola, Aleš (advisor)
This magister’s thesis is about modern lighting of vehicles, the visual range and afterglow in poor visibility. The first part of the thesis provides a detailed analysis of the current situation and problems, including a comprehensive description of the sources of light radiation, lamps, structures, and describe the systems used in modern lighting technology of vehicles. In the second part of the thesis there are the scientific methods to determine the issue of visual range and afterglow of the headlights. The second part is about the application of acquired techniques to detect an afterglow and the visual range of vehicles with modern headlights with a light source with xenon lamp, compared with a vehicle with a halogen lamp and a vehicle with an older halogen headlight.
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Photoimpedace spectroscopy characterization of optical and electrical properties of the photovoltaic cells
Mocharová, Zuzana ; Chladil, Ladislav (referee) ; Novák, Vítězslav (advisor)
Diploma thesis mainly describes the theoretical knowledge of the topic photoimpedance spectroscopy characterization of optical and electrical properties of the photovoltaic cells, which contains development and princip of cells working, material properties of photovoltaic cells, explanation of electromagnetic waves, spectrophotometry and impedance spectroscopy, followed by a discription of the measuring device and used measuring methods. The experimental section for each measurement method describes the steps of setting the program, then the tables with measured values are involeved in some parts and a part of each method are summary graphs of measured values with subsequent evaluation.
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