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Ionizing radiation as a topic of environmental education
VANĚČEK, Marcel
Ionizing radiation is a physical factor that has a significant effect on human health. An average person on Earth is irradiated at an average of 2.4 mSv per year. Most of this dose comes from natural sources, especially radon. High levels of radon are the second most common cause of lung cancer after smoking. At present there is an increase in exposure from medical sources which in some developed countries may equal to exposure from natural sources. Basic knowledge about sources of ionizing radiation, its effects and protection against it should be known to all high school students. The diploma thesis focuses on ionizing radiation from the perspective of high school teachers and students. It is divided into two main parts. In the first theoretical part the issue of ionizing radiation as a physical factor affecting human health is discussed. It describes the origin of ionizing radiation, basic concepts such as radioactivity and half-life, there are different types of radiation, individual sources, effects and protection against it. The second practical part is focused on examining the knowledge of high school students on this issue. The work tries to solve several goals. The first goal of the thesis is analysing the approach of high school teachers to information about the topic of ionizing radiation. The second goal is to verify the knowledge of high school students. The third goal is to evaluate whether high school students have a better knowledge of the topic of ionizing radiation than grammar school students. The fourth and last goal of the diploma thesis is to write a freely accessible material about the topic of ionizing radiation for high school teachers and students. This material will serve as an information source during the creation of the educational material for teachers teaching on the topic of ionizing radiation, but it can also be used by students while preparing seminar papers.
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Nuclear accidents and subsequent measures to protect the population
SVITÁK, Daniel
This bachelor thesis deals with the protection of the population and subsequent measures in the event of a radiation emergency. When comparing the two largest nuclear accidents (Chernobyl and Fukushima), a great similarity was found not only in the implementation of safeguard measures, but also in the errors made by the responsible authorities. By comparing these events, we could answer the question of how the approach to protecting the population differed in the bipolar division of the world from the perspective of the "Eastern", which is represented by the former USSR and the view of the "Western" represented by Japan. With the resulting analysis, we confirmed that in both the USSR and Japan, this approach differed only in the source of the likely risk, which was given greater attention than the other risks. In case of comparison of the measures of protection of the population of the Czech Republic, which are mentioned in the emergency plans, with those introduced in the world in the case of The RMU, we concluded that the measures of the Czech Republic are on the same level and can be considered as a world standard. To support the resulting claims, the measures introduced at the Fukushima RMU are compared with those during the 2015 Zone Temelín emergency exercise. An integral part is the evaluation of the level of information of the Czech population in the field of protection of the population. An analysis of the results of the supplementary questionnaire survey confirmed the claim of low level of information of the inhabitants of the Czech Republic. Therefore, the work will also focus on the need to raise public awareness in the field of population protection and propose measures to raise the level of information to the required level.
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Adaptive radiation of the genus Rattus
Skalíková, Hana ; Frynta, Daniel (advisor) ; Mazoch, Vladimír (referee)
Rats are an important group of rodents originating and living mainly in southeast Asia. They are important pests and reservoirs of zoonosis. Yet, about many species we only have basic information. Here, I summarized available information about 66 species of the genus Rattus and 10 species of the genus Bandicota, Diplothrix, Limnomys, Nesokia and Tarsomys. I focused on distribution, ecology and morphology (body lenght, tail lenght, hind food lenght and ear lenght) and their mutual relationships. The body lenght differs beetwen phylogenetic lineages and beetwen habitats. The other morphological characters (tail lenght, hind food lenght and ear lenght) correlated with body lenght. Further, I describe an adaptive radiation of rats. Rats are separated into several lineages, diferring in their geographic distribution and ecology. Moreover, many species are commensal, that is benefiting from close relationship with humans. Commensalism species can be found in several lineages of rats, therefore commensalism probably developped independently more than once. The commencalism was origined several times. I discuse why are some commensal species more successful than others. Key words: adaptive radiation, Bandicota, commensal species, ecomorphology, Rattus, rodents, southeast Asia
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Bird diversity and diversification: Different processes converging to the same pattern?
Černá, Vladimíra ; Storch, David (advisor) ; Hulva, Pavel (referee)
Latitudinal diversity gradient is one of the oldest known trends in the distribution of life on the Earth. Scientists have been trying to find causes of its formation for more than two hundred years. There are several hypotheses suggested to explain this gradient. Recently, it is one of the main themes of discussion among ecologists and evolutionary biologists. By this Thesis, I will try to contribute to understanding of processes that generate the latitudinal diversity gradient. Particularly, I study if there is a relationship between ambient temperature and diversification rate. Is this relationship different for individual groups of animals? I choose birds as a model group. Specifically, these six families of birds: Accipitridae, Columbidae, Furnariidae, Picidae, Psittacidae and Strigidae. These groups include more than 1500 species. Each of them has the same universal gradient of diversity, with the highest diversity concentrated in the tropics. My objective was to find out, whether the universal gradients of bird's diversity had been shaped by the same historical processes. Or alternatively, whether different evolutionary trajectories had converged to the same gradients. The main outcome of my work is a discovery that some of the selected families diversified faster in warmer climates...
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Simplified modelling of tube bank heat exchanger in CFD
Cacková, Tereza ; Juřena, Tomáš (referee) ; Vondál, Jiří (advisor)
The master thesis deals with the replacement of heat exchanger surfaces during simulations in the ANSYS Fluent. The aim of this work is to find a simplified model of the heat exchanger usable for flow simulations in large process and energy units, where it is not possible to model the entire heat exchanger in detail. The calculation procedures are applied to „tube bank” heat exchanger. The master thesis is divided into three parts. First part deals with pressure losses. The "porous zone" approach is used as a replacement for the heat exchanger surface. In the second part, the heat transfer by convection and conduction through the heat exchanger is replaced by the "Heat Exchanger" module. The third part examines the influence of material properties, heat source and fixed temperatures on incident radiation. All calculations resulting from the methods are performed using a script that prepares the output data in format suitable for insertion into ANSYS Fluent. A simplification, which faithfully replaces a fully modeled heat exchanger, has been found in all three parts of the thesis.
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Adaptive radiation of the genus Rattus
Skalíková, Hana ; Frynta, Daniel (advisor) ; Mazoch, Vladimír (referee)
Rats are an important group of rodents originating and living mainly in southeast Asia. They are important pests and reservoirs of zoonosis. Yet, about many species we only have basic information. Here, I summarized available information about 66 species of the genus Rattus and 10 species of the genus Bandicota, Diplothrix, Limnomys, Nesokia and Tarsomys. I focused on distribution, ecology and morphology (body lenght, tail lenght, hind food lenght and ear lenght) and their mutual relationships. The body lenght differs beetwen phylogenetic lineages and beetwen habitats. The other morphological characters (tail lenght, hind food lenght and ear lenght) correlated with body lenght. Further, I describe an adaptive radiation of rats. Rats are separated into several lineages, diferring in their geographic distribution and ecology. Moreover, many species are commensal, that is benefiting from close relationship with humans. Commensalism species can be found in several lineages of rats, therefore commensalism probably developped independently more than once. The commencalism was origined several times. I discuse why are some commensal species more successful than others. Key words: adaptive radiation, Bandicota, commensal species, ecomorphology, Rattus, rodents, southeast Asia
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New Trends in Ionizing Radiation Shielding Research and Development
Vláčil, Martin ; Šťastný, Ondřej (referee) ; Katovský, Karel (advisor)
This thesis deals with the problem of shielding ionizing radiation which is a beam that has enough energy to ionize an atom or a molecule of an irradiated substance. This radiation can occur in nuclear facilities such as a nuclear power plant, a particle accelerator, or in X-rays in healthcare. Until now, standard shielding materials, most often lead or concrete, have been used to protect against ionizing radiation. New trends are therefore trying to replace these materials with lighter, more effective and harmless materials. The practical part is focused on measure the data to obtain the basic properties of shielding materials, such as the attenuation factor and the buildup factor. A measuring platform is described here, which can be used to measure the data needed to calculate the attenuation factor and the buildup factor. The measurement results are compared with tabular values to determine the accuracy of the measurements. Furthermore, the results of measurements of five concrete materials from the company MICo, spol. s r.o. To obtain theoretical values, the simulation program MCNP6 was used, in which it is possible to create a model of the measuring platform, which was used in practical measurements. Next the shielding material, source and detector are defined. The result lead again to the data needed to determine the attenuation factor. The results of measurement and simulation data in MCNP6 are evaluated and graphically processed into such a form that it is possible to compare the properties of shielding materials with each other.
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Investigation of impact of radiant heating and cooling on car driver thermal comfort
Pavlík, Vojtěch ; Tuhovčák, Ján (referee) ; Fišer, Jan (advisor)
This diploma thesis is focused on the matter of radiation heating, thermal comfort maintenance and setting optimal operation parameters for heating system equipped with radiation panels. The research section summarizes the effects most important for thermal comfort, methods of its determination, heat exchange distribution between the human body and its environment, and technical possibilities of heating car interiors. The central points of this work are the simulation of car interiors heated with radiation panels and the evaluation of thermal comfort with a virtual mannequin. Thermal state was determined via the equivalent temperature and thermal comfort zones diagram (method by O.H. Nilsson). Forty-two simulated scenarios led us to conclude that thermal comfort is not possible to obtain with panels exuding a maximum temperature of 43 °C and the combination of several heat sources is required. Nevertheless radiation heating considerably contributes to energy savings without the loss of thermal comfort in assessed car.
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The effects of ionizing radiation on semiconductor devices properties
Yermalayeva, Darya ; Šteffan, Pavel (referee) ; Musil, Vladislav (advisor)
This master’s thesis deals with the problematics of influence of ionizing radiation on semiconductor devices and their properties. The aim of the thesis is to analyze the different types of radiation that can occur in the areas of application of these components. In the second part, the degradation processes are explored, with emphasis on the influence caused by the radiation dose. Also, the displacement damage and SEE effects are described, but just slightly, because they are not part of this work. The third part describes the device design process and harmful effects, that have to be considered during the design phase. In the forth and the fifth parts of this work were done modeling of radiation effects (influence of dose rate, Single-Event Upset and Total Ionizing Dose) in PSpice program and was carried out the possibility of designing a simple dosimeter with silicon diode. In conclusion, the results of the thesis are summarized and evaluated.
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Evolutionary history of Orchidaceae in the Mediterranean basin
Jankolová, Lucie ; Ponert, Jan (advisor) ; Chrtek, Jindřich (referee)
The matter of this text is the Orchidaceae family occuring mainly in the Mediterranean basin. The selected genera from the Orchidinae subtribe are discuted, namely it is about Anacamptis, Neotinea, Ophrys, Orchis and Serapias genera. Different genera of this family have tendency to diversify to a different extent, some of them content thousands of taxa, another have orderly onely few dozens of them. The work is therefore focused on the genera themselves and on the factors, that may have had any influence on their diversification. Key words: evolution, radiation, mediterranean climate, Orchidaceae, diversification, diversity, Mediterranean basin
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