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Presence of heavy metals in vicinity of the roads in Brno
Brzobohatý, Jan ; Adamec, Vladimír (referee) ; Doležalová Weissmannová, Helena (advisor)
Diploma thesis deals with the risk assessment of metals in soils near roads in the city of Brno. For samples collection has been chosen twenty-five localities which were divided into five groups depending on the traffic load, in order to compare the impact of transport on the risk of soil contamination with metals. In the soil samples were determined levels of six hazardous metals (Cd, Hg, Pb, Zn, Ni, Cu). Lead, zinc, nickel and copper were determined by the flame atomic absorption spectrometry (F-AAS), cadmium by the electrotermic atomic absorption spectrometry (ET-AAS) and mercury by the advanced mercury analyzer AMA 254.
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The effect of lubricant contamination and degradation on lubricating film behavior
Strnad, Jan ; Dzimko, Marián (referee) ; Omasta, Milan (advisor)
Lubrication contamination and degradation is one of the major causes of unexpected failure of tribological nodes. As a result, different levels of maintenance are introduced in practice, leading to a longer service life of the lubricated node. These systems often include sophisticated on-line diagnostic tools that can be used to evaluate a sample of a lubricant using certain variables such as viscosity, number of particles, humidity, dielectric constant, etc. Based on changes of these variables some systems can make corrective measures such as filtering or complete replacement of lubricant. Therefore, the aim of this experimental thesis is to determine the influence of lubrication contamination (solid particles, moisture) and degradation (oxidation) on the lubricating film behavior with respect to its limit bearing capacity. To examine the thickness of the lubricating film, friction and wear, an optical and MTM tribometer, in the ball-on-disc configuration, was used.
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Influence of the grease aging to its behavior in the vicinity of the elastohydrodynamic contact
Navrátil, Marek ; Dzimko, Marián (referee) ; Košťál, David (advisor)
This thesis aims to describe the differences in grease behaviour caused by degradation. Observation of EHL contact and its surroundings is done using optical fluorescence, which allows to measure lubricant thickness even if it is discontinuous and air is present. New grease is observed, along with samples aged in bearings. One sample was worked for 1000 hours, which was the planned duration of the experiment. Two other samples were stopped prematurely after approx. 900 hours. Several possible age-related factors were examined and strong link between contamination and grease behaviour was found. In observed cases, contamination was identified to be the leading cause of lubricant shortage near EHL contact, which is one of possible bearing failure causes. The results expand existing knowledge about grease lubrication topic, but much further research is needed.
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Ecotoxicological evaluation of biochar via organism Folsomia candida
Marcinko, Juraj ; Procházková, Petra (referee) ; Zlámalová Gargošová, Helena (advisor)
The aim of this bachelor thesis was to ecotoxicologically evaluate selected biochar samples and to assess, using a test organism, the possible long-term and short-term effects on soil invertebrates. One of the possible uses of biomass is to convert it into biochar with subsequent application to soil. Soil fauna may be affected after biochar application, therefore ecotoxicological tests in a contact arrangement were chosen. Folsomia candida was used as the test organism. Short-term effects were recorded through escape tests, specifically low abundance of organisms in samples (I) and (T). Significant preference of organisms was observed for sample (O). Samples (I) and (T) had a further impact on the survival of organisms and on the quality of reproduction, where in some cases this caused a resolute impact. Sample (O), at different concentration levels, had no effect on the test organisms. The results of these tests approximate how soil invertebrates could be affected after biochar application.
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Growth of 3D Structures Induced by Electron Beam on Ceramic Substrates
Bukvišová, Kristýna ; Čechal, Jan (referee) ; Salamon, David (advisor)
Vystaví-li se vzorek působení elektronového svazku, dojde na jeho povrchu ke strukturním změnám. Jednou z těchto změn je vertikální růst 3D struktur na keramických materiálech. V práci jsou zkoumány podmínky nutné pro takový proces. Nárůst teploty často zapříčiní povrchové změny, proto je v práci proveden výpočet ohřevu materiálu elektronovým svazkem. Dále je zkoumán vliv různých parametrů svazku na růst 3D struktur, závislost objemu a rozměrů je analyzována pomocí AFM. Výsledný odhad nárůstu teploty se pohybuje v řádech jednotek, maximálně desítek K. Výrazný objemový růst je pozorován pro nízká urychlovací napětí a malé proudy. Výška vzniklých struktur dosahuje 100 nm za minutu a je nepřímo úměrná velikosti proudu.
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Decontamination of Persons at Medical Facilites during CBR Events
Magulová, Eva ; Urbánek, Pavel (referee) ; Rosická, Zdena (advisor)
The aim of this work is the effort to bring new insight into the possibility of decontamination in healthcare facilities. In the first part are briefly explained keywords. The second part is a brief preview of the sarin attack in the Tokyo metro and the cooperation of Japanese rescue system in this event. It is followed by estimated procedure of integrated rescue system of the Czech Republic at the same event in the Czech Republic. Then is a proposal of some problems arising from improvised decontamination in the unequipped hospital and a proposal for the possible course of decontamination in a medical device.
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The study of contamination of forested areas of the Czech Republic by mercury
Trávníčková, Gabriela ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
This bachelor thesis deals with the issue of mercury in the environment. It focuses on determining the concentration of total mercury in edible mushrooms and in the soil in 12 localities in the Jeseníky Mountains. A single-purpose absorption spectrometer AMA 254 was used to determine the mercury content. The sites where sampling took place were divided into 6 sites with spruce stand and 6 sites with beech stand. No relationship was found between the type of stand and the amount of accumulated mercury in the mushrooms. On a representative sample of yellow-boletus mushrooms found in each locality, it was found that the higher the amount of mercury in the mushroom, the lower the amount of mercury in the soil. The fungi are therefore able to accumulate mercury from the environment. Thus, they can become a potential source of intoxication when ingested. The mobility of heavy metals in the soils depends on many soil properties (pH, carbon and sulfur content). Metals form more soluble compounds in lower pH environments. The soil pH was very low and the lower the soil pH, the higher mercury concentration in the soil. This fact could be supported by acid fallout. The relationship between the mercury content and the carbon content of the soil confirmed that carbon has the ability to bind mercury. The higher the amount of carbon in the soil, the higher the amount of mercury.
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Drinking water contamination in water supply system
Černíková, Eva ; Třasoňová, Pavla (referee) ; Ručka, Jan (advisor)
The aim of this thesis is to consider the possible causes and consequences of contamination of drinking water in the water supply system. In the introduction are general information about the problems with water supply and some new approaches to water distribution system. In the next part there are described components of the water supply system and how they work. There are also described problems of drinking water contamination in water supply system. What are the mechanisms, what causes the turbidity and which microorganisms are the most common source of infections. In the final part there are described individual cases of drinking water contamination and what were the consequences. In the beginning there is a short form to every case which provides you a quick orientation in the problem.
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Assessment of soils and sediments contamination by heavy metals in the region Jihlava river
Marek, Milan ; Adamec, Vladimír (referee) ; Doležalová Weissmannová, Helena (advisor)
This diploma thesis deals with a potential contamination of hazardous metals of soil and sediments. The metals cadmium, copper, lead and mercury were chosen, their specification, limited concentration and methods of determination are also described in thesis. City Jihlava and its surroundings were chosen for evaluating pollution of the soil and sediments in this area. In collected samples of the soil and sediments presence of copper, cadmium, lead and mercury were detected via atomic absorption spectrometry (F-AAS, ET-AAS, AMA 254). The metal pollution of soils and sediments by hazardous elements in Jihlava River and in Jihlava region was evaluated.
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