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ECG generator for equipment testing
Čech, Petr ; Rampl, Ivan (referee) ; Chmelař, Milan (advisor)
This diploma thesis is focused on testing ECG monitors and ECG instruments. There are discussed origin and charakteristics of ECG signal. The ECG signal is presented by standard leads. This is the reason, why the way of making leads is mentioned. One chapter is aimed at generating ECG signal. There are set requierements for the ECG generator. These requierements results from ECG instrument possibilities and from ECG signal character. Next part of this diploma thesis includes hardware design of each part of the system. The system was designed with respect to mobility and 12-leads systems compatibility. Finaly the thesis includes design of the controll software.
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Heavy metal contamination of selected Brno city localities
Šebková, Michaela ; Sommer, Lumír (referee) ; Dočekalová, Hana (advisor)
The aim of this work is to study the soil and plant contamination by heavy metals (lead, cadmium and mercury) in five selected places of Brno city. The sampling place Opuštěná represents the heavily polluted locality with high traffic density situated in the city centre. Sampling places Vídeňská and Podstránská belong to medium polluted localities, that are situated close to frequented roads. Relatively clean localities are represented by Musorgského and Šrámkova places, which are situated in peripheral city district with smaller traffic density. Soil and plants were sampled at two time periods (November 2008 and January 2009). Average amounts of mercury, cadmium and lead in collected soil samples are lower then limits of the Directive number 13/1994 of the Code of Ministry of the Environment. The content of heavy metals in soils corresponds to the sampling place. The highest value of metals content was found in the soil sampled at Opuštěná site. The content of lead and mercury in leaves of common dandelion was higher than the content in roots. In the case of cadmium the situation was opposite, the highest content was measured in underground part of the plant. It was found, that the content of heavy metals in leafy and underground part showed only small difference between sampling places. Nevertheless, the locality Opuštěná is found again as the highest contaminated place. Values of pH of collected soil samples were ranged in neutral area between 7 and 7,5.
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Additional Treatment of Drinking Water at the Point of Consumption
Hrubý, Ladislav ; Biela, Renata (referee) ; Kučera, Tomáš (advisor)
This bachelor’s thesis deals with problem of pollution in drinking water during its transport towards consumers. It particularly deals issues with heavy metals such as lead, copper and sums up methods which can be used when trying to remove such metals at water connections or taps. Next, particular filter materials are described together with processes that happen during filtration. Finally, a short experiment has been performed for finding out the most appropriate filter material.
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Fixation of the lead in alkali activated materials based on different types of ashes
Cába, Vladislav ; Kalina, Lukáš (referee) ; Koplík, Jan (advisor)
The aim of this work was to develop an alkali activated matrix based mainly on fly ash, to determine the ability to fix lead in these matrices, the impact of added lead on mechanical properties and to reveal the way of lead fixation in these matrices. The matrices consisted mainly of fly ash (four from fluidized bed combustion, one pulverized coal combustion) with an admixture of blast furnace slag and sodium silicate as an activator. Lechates were prepared on the basis of the ČSN EN - 12457-4 standard, lead concentrations in them were measured using an atomic emission spectrometer with inductively coupled plasma. The strengths of the samples were measured after 28 days. Images, element maps and element spectra were taken to determine the structure using a scanning electron microscope with an electron dispersion spectrometer, the samples were analyzed on an infrared spectrometer with a Furier transform, X-ray diffraction analysis and electron spectroscopy for chemical analysis were also used. The individual measurements showed that lead is accumulated in the form of hydroxide. The impact of lead doping on strength of the matrix was different for individual samples. Matrices from both types of fly ash released minimal amounts of lead into leachates, so it is possible to use them to fixate lead.
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Use of pollution indices for evaluation of soil contamination
Čmelíková, Dorota ; Pavlovský, Jiří (referee) ; Doležalová Weissmannová, Helena (advisor)
This thesis focuses on heavy metal contamination of soil and the use of pollution indices for its evaluation. Two regions were selected for assessment and comparison. The chosen heavy metals were mercury, zinc, copper, lead and cadmium. These heavy metals were analysed in 15 samples from Kyjov nad 15 samples from Ostrava. Methods of analysis were AMA-254 and FAAS. The established concentrations were used to calculate pollution indices and for health risk assessment. Pollution in Kyjov was assessed as low to medium without any health risks. Ostrava region was assessed as moderately to highly polluted with a low health risk, especially for children.
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Low pressure plasma application for the surface cleaning of archaeological objects
Bubnová, Kateřina ; Grossmannová, Hana (referee) ; Krčma, František (advisor)
This diploma thesis builds on my bachelor thesis, which was focused on the application of low-pressure hydrogen plasma and argon-hydrogen plasma on layers of corrosion products. According to results of the experiments, an appropriate temperature for plasma chemical treatment of lead samples was detected. However, the process of corrosion removal through plasma chemical treatment needs to be further optimized to prevent potential damage to the original historical artefacts. Optimization of the treatment process is therefore the main subject of this work’s research. The model samples with artificial corrosion layers with dual composition were prepared. These samples were put to desiccator with sand and organic acid. The samples corroded in environment of acetic acid or formic acid with the aim of creating the corrosion, which would be at least partially simulated with corrosion on the original artefacts. The process of corrosion lasted for eleven months. After that, the samples were dried out under reduced pressure, put to the protecting foil with humid and oxygen absorbers. In contrast with my bachelor thesis where the continuous regime was chosen for the treatment, the pulse regime with three different condition settings is used. Process of experiment was monitored by OES, surface of samples was analyzed by SEM, EDX, XRD methods. Results from experiments with model samples were used for treatment of original artefacts with missing documentation, so their eventual damaging was acceptable.
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Environmental Aspects of Pyrotechnic Mixtures.
Mešková, Michala ; Bednařík, Karel (referee) ; Friedl, Zdeněk (advisor)
The submitted bachelor thesis deals with the study of pyrotechnic compositions and their influence on the health and environment. It explains the nature and ingredients used in pyrotechnic compositions. During burning these compositions release different compounds, toxic or non-toxic into the atmosphere in large quantities. In this work the issue of toxicity of selected alkali, alkaline earth metals and the other harmful metals was explored. The pyrotechnic compositions containing Ba, As, Pb and Cd were investigated in more detail. When burning the pyrotechnic compositions release noxious substances into the air first. Then these substances reach due to wet or dry transport mechanism the other components of the environment and mix with them. These compounds have diverse negative effects both on humans and the environment and other animals.
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Determination of lead in lung and brain samples of experimental mice after the inhalation of nanoparticles
Demydenko, Yana ; Zlámalová Gargošová, Helena (referee) ; Vašinová Galiová, Michaela (advisor)
Lead is a heavy toxic metal whose nanoparticles are present in the air due to combustion processes. Data on the safe concentration of lead nanoparticles for human health have not been sufficiently investigated. Previous studies in experimental mice have shown that inhalation of lead nanoparticles first damages lungs and kidneys, then liver, spleen and brain. With prolonged exposure, lead accumulates in the teeth and bones. This bachelor thesis is focused on monitoring of the lead content in lung and brain samples of experimental mice after different periods of nanoparticle inhalation. The aim of this bachelor thesis was to develop an analytical method for the determination of lead in biological samples using atomic absorption spectrometry with electrothermal atomization (ET-AAS). In this work, a decomposition method for mineralization of the biological matrix in a microwave mineralizer was proposed, and a procedure for the determination of lead using ET-AAS was further developed. The determination of lead at 217 nm using the NH4H2PO4/Mg(NO3)2 matrix modifier was verified by analysis of certified reference materials. Analysis of organ samples from experimental mice confirmed the detoxification mechanism in exposed individuals with a dependence on the time since the end of inhalation of lead nanoparticles.
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