|
|
Thick-film sensors for heavy metals detection
Gajdoš, Libor ; Majzlíková, Petra (referee) ; Prášek, Jan (advisor)
This project describes the possibilities of heavy metals detections in solutions using differential pulse voltammetry with tree-electrode electrochemical thick-film sensors. In the theoretical part, the thick-film technology is described as well as thick-film pastes’ types and compositions, followed by introduction to electrochemistry and electro-analytical methods of measurement. This project also describes the three measured heavy metals – cadmium, lead and copper. In the practical part, heavy metals’ ions detection in solutions using carbon working electrode and determination of the detection limit and sensitivity are described and discussed. Finally the evaluation of obtained results and results comparison to hygienic limits are included.
|
|
|
Corrosion layers removal in low-pressure plasma
Kujawa, Adam ; Grossmannová, Hana (referee) ; Krčma, František (advisor)
A plasmachemical reduction of corrosion layers on copper was studied. In this case two series of copper samples were prepared and putted in two corrosive environments for one week. The first corrosive environment contained a concentrated nitric acid and the second environment contained a concentrated sulfuric acid. Samples thus prepared were ready to be plasmachemicaly treated. The plasmachemical reductions took place in low-temperature, low-pressure, non-isothermal, high-frequency-inducted hydrogen plasma on the Faculty of Chemistry in University of Technology in Brno. The discharge was generated in continual or pulse mode with changeable pulse ratio. To monitor the reduction process an optical emission spectroscopy was used. The radiation from plasma discharge was measured by an optical spectrometer in the intervals of 1 to 10 minutes. An object of our concern in collected spectrum was the radiation of OH radicals with electromagnetical wavelenght in a range of 305 – 330 nm, and which were produced in a reaction between the hydrogen radicals and the oxygen atoms, contained in the corosion layers. A rotation temperature of plasma was calculated from the spectrums of OH radicals in a dependence of discharge conditions. Gathered findings will give us a better knowing of this conservation technique, that is used for treatment of the corroded surfaces of the archeological artifacts, and will also allow more provident appliance of this method on a copper historical objects.
|
|
|
Reconstruction of the town spa in Malé Svatoňovice
Macek, Štěpán ; Špiller, Martin (referee) ; Guzdek, Adam (advisor) ; Kalousek, Lubor (advisor)
The aim of the bachelor thesis was to prepare a documentation for building permits and a part of the documentation for the building construction on the basis of an architectural study, developed in the „AG35 – Monuments Restoration Studio“ module. The topic of the studio work was to think about the appropriate use of a listed building in the historic center of the village of Malé Svatoňovice and to create an architectural study. I have proposed the following concept. The building should serve as a municipal house, so I have concentrated the corresponding functions here: the municipal office, the ceremonial hall, the museum, doctors labs, cosmetics, the pharmacy and finally the spa, which had a long tradition here. When restoring an object, I proceed synthetically. I examine the quality and preservation of individual layers. Then I highlight the best of each one. If some layer have not been preserved, but still have had its qualities, I remind it in a new language. I think it was Tadao Ando who said, "If the genius loci is to be legible, it must be revived and provoked by inventive inputs." I combine modern with historical using timelessness.
|
|
|
Options for increasing the efficiency of small motors.
Kusý, Karel ; Janda, Marcel (referee) ; Hájek, Vítězslav (advisor)
This bachelor thesis concerns itself with the possibilities of achieving higher efficiency of small asynchronous motors and their manufacturing costs. The following chapters describe the design, function and principles of speed regulation of the asynchronous motor. Next, losses that occur during motor operation and ways of reducing them, are described. The last chapter of the thesis addreses factors that influence the manufacturing costs of the asynchornous motor and evaluates the material costs of one modified motor.
|
|
| |
|
|
Metals Transport in the System Soil/Plant. Comparison of the Active and Passive Sampling Method (The Diffusive Gradients in Thin Films Technique)
Trávníčková, Jana ; Janoš, Pavel (referee) ; Chýlková, Jaromíra (referee) ; Čelechovská, Olga (referee) ; Dočekalová, Hana (advisor)
The doctoral thesis deals with comparison between copper uptake by radish (Raphanus sativus L.) and concentration of copper measured by a DGT-device and concentration of copper obtained by extraction with generally used extraction agents (HNO3, NaNO3 and water). Plants were cultivated in pot experiments on a tested non-treated and gradually spiked soil. The amount of copper was determined in various part of radish (whole plant, above- and below-ground part) after mineralization in the APION mineralizer by ET – AAS. The highest concentration was in belowground part, especially in root tissues and sheel of root bulb. It confirms copper is associated with cell walls. The amount of copper taken by radish up does not pass beyond sanitary standards not even in spiked soils and consummation of radish is not unhealthy. Good correlations were found between copper concentration in radish and the amount of copper extracted with HNO3, NaNO3 and water and the amount found in soil solution. Results of extraction with HNO3 confirmed the amount of copper was stable in spiked soils during the pot experiments. The DGT experiments have shown that the rate of resupply from the solid phase to soil solution is constant during the deployment time. Whereas the release of copper decreases after 24 hours in natural soil. Copper added to soil in form of cupric ions is present in the different form after one month-equilibration than copper present in unspiked soils. The results obtained by DGT measurements were approximately up to two orders of magnitude lower than copper concentration obtained by leaching with sodium nitrate. The extraction with sodium nitrate does not provide true reflection of metal availability to plant root system and soil microorganism. High values of correlation coefficients (R2 > 0,9) were found between concentration of copper in radish plant and the concentration of copper in soil solution measured by DGT technique. Concentration of copper in soil solution was three times higher than concentration measured by DGT technique. Soil solution contains species of copper that are not measured by DGT technique and available to plants. Concentration of metals obtained by DGT measurements is more closely to real concentration of bioavailable forms of metal in soil. Therefore it is possible to recommend the DGT technique as a technique for determination of bioavailable forms of copper in soils.
|
|
|
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.
|
|
|
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.
|
|
|
Cathedral today
Rampáčková, Monika ; Mléčka, Jan (referee) ; Štěpán, Marek (advisor)
The master's thesis deals with famous Notre-Dame de Paris, which was destroyed by fire in 2019. The work focuses specifically on the design of completion of the construction. The cathedral is situated in the historical centre of Paris on the Île de la Cité. A lot of damage was caused to the building after the devastating fire on 15 April 2019. The aim of the thesis was to create a spiritual place that would maintain its past, but at the same time manage to follow ecological solutions in the present. The new design of the attic creates a sacred place, in which we realize the importance of faith and the peace of God. The cathedral is open to the general public ? religious people from all over the world come here to experience the love, joy and happiness that the cathedral invokes. The whole attic can be described as an open space, which symbolizes infinity or immortality from the religious point of view. It represents the connection of the past, present and future. The space is designed to hold priestly celebrations and to be open for the public. It can also be used for various events, such as exhibitions of sculptures that survived the fire.
|
|
|
Calorimetric study of interactions of humic substances with metal ions
Solná, Irena ; Pospíšilová, Ľubica (referee) ; Klučáková, Martina (advisor)
The main object of the diploma thesis is study of interaction beetween humic acids and selected metal ions using calorimetric titration. The research about reactivity of humic substances is done comparing the different models used to describe the variety of properties of humic substances. In experimental part the methods of FT-IR spektrometry, potenciometric and conductometric titration are used to recieve the total acidity and carboxylic acidity of lignite humic acid. The optimalization of isothermic titration calorimetry is done to be used within study of reactivity of humic acids, revealing the best correlation with sols of studied humic acid. The basic organic compounds were used including benzoic acid, ftalic acid, salycilic acid, pyrocatechol and phenol as models of bonding groups in humic acids. The reaction enthalpy was calculated from the titration of models and results were compared with semiempiric quantum chemistry calculations following INDO method.
|
guest ::
