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Influence of pyrrolidone derivates on alkyd and polyurethane coatings.
Klímová, Edita ; Molliková, Eva (referee) ; Tulka, Jaromír (advisor)
The aim of this thesis was to append data on chemical resistance of coatings made of paints based on alkyd and polyurethane resins. In the theoretical part, relevant information on coatings, preparation of their systems, theory of solubilization and properties of solvents were collected and organized. Three N-derivates of pyrrolidone were chosen for the practical part. Their influence on particular alkyd and polyurethane coatings was studied with emphasis on time course of coatings degradation.
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Preparation and characterization of plasma activated water
Lemonová, Hana ; Klímová, Edita (referee) ; Krčma, František (advisor)
This bachelor thesis deals with suitable methods for plasma activated water preparation. The plasma activated water is a new way of the indirect plasma application for the treatment of biological materials like food or even for the direct application for therapeutic purposes. The theoretical part is focused on getting acquainted with plasma activated water and methods for its preparation, using various plasma systems. The detailed description of the plasma-liquid systems used during this thesis is given later. The selected physical chemical properties, namely conductivity, pH value and stability of hydrogen peroxide are presented in the results part. An important aspect of this work was to find suitable storage conditions for plasma activated water.
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Electric discharges in water and organic solutions
Klímová, Edita ; Brablec, Antonín (referee) ; Kozáková, Zdenka (advisor)
This work is focused on study of electrical discharges in liquids, especially in water solutions. Generation of the discharge in water solutions leads to simultaneous effect of UV radiation, shock waves, electrical field and most importantly, chemically reactive species. This can be utilized in many applications such as sterilization, degradation of organic waste products, lithotripsy or other medical applications. The experimental part is concentrated on a diaphragm arrangement of the reaction system. This means that the reactor is divided into two electrode reservoirs connected only through a small orifice in a dielectric barrier. This barrier is made of Macor® non-porous ceramics with thickness of 1 mm, with the diameter of the orifice 0.6 mm, in the first part of work. In the second part, ShapalTM-M ceramics of thickness 1.0 mm and orifice diameter 0.6 mm was used. The experimental part is divided into two sections. For both, NaCl is chosen as an electrolyte to set the initial conductivity of the tested solutions to the value of 400 S/cm. Supplied direct voltage is regulated to attain power of 100 W in the system. In the first part, effect of addition of chosen alcohols (ethanol, isopropylalcohol and glycerol) on the efficiency of the discharge in their water solutions is studied. For this purpose, a special glass reactor was designed and constructed. The efficiency of the discharge is measured by a spectroscopic determination of concentration of complex formed by a titanium reagent and hydrogen peroxide, which is generated during the discharge. The results show no positive effect of addition of extra OH group to the reaction through the alcohols. The use of isopropylalcohol causes even a significant decrease in the amount of hydrogen peroxide generated. The subject of the second part is a comparison of effect of different electrode materials on the discharge. The efficiency is measured by the same method as in the first part. Materials chosen were stainless steel, platinum, aluminium, copper and carbon. Each material shows different hydrogen peroxide production rate under the same parameters. The most perspective material seems to be carbon, as an inert material, that can be expected not to initiate any decomposition of hydrogen peroxide. The least favourable appears to be copper. When used, no production of hydrogen peroxide was observed in one of the electrode parts of the reactor.
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Preparation and characterization of plasma activated water
Lemonová, Hana ; Klímová, Edita (referee) ; Krčma, František (advisor)
This bachelor thesis deals with suitable methods for plasma activated water preparation. The plasma activated water is a new way of the indirect plasma application for the treatment of biological materials like food or even for the direct application for therapeutic purposes. The theoretical part is focused on getting acquainted with plasma activated water and methods for its preparation, using various plasma systems. The detailed description of the plasma-liquid systems used during this thesis is given later. The selected physical chemical properties, namely conductivity, pH value and stability of hydrogen peroxide are presented in the results part. An important aspect of this work was to find suitable storage conditions for plasma activated water.
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Electric discharges in water and organic solutions
Klímová, Edita ; Brablec, Antonín (referee) ; Kozáková, Zdenka (advisor)
This work is focused on study of electrical discharges in liquids, especially in water solutions. Generation of the discharge in water solutions leads to simultaneous effect of UV radiation, shock waves, electrical field and most importantly, chemically reactive species. This can be utilized in many applications such as sterilization, degradation of organic waste products, lithotripsy or other medical applications. The experimental part is concentrated on a diaphragm arrangement of the reaction system. This means that the reactor is divided into two electrode reservoirs connected only through a small orifice in a dielectric barrier. This barrier is made of Macor® non-porous ceramics with thickness of 1 mm, with the diameter of the orifice 0.6 mm, in the first part of work. In the second part, ShapalTM-M ceramics of thickness 1.0 mm and orifice diameter 0.6 mm was used. The experimental part is divided into two sections. For both, NaCl is chosen as an electrolyte to set the initial conductivity of the tested solutions to the value of 400 S/cm. Supplied direct voltage is regulated to attain power of 100 W in the system. In the first part, effect of addition of chosen alcohols (ethanol, isopropylalcohol and glycerol) on the efficiency of the discharge in their water solutions is studied. For this purpose, a special glass reactor was designed and constructed. The efficiency of the discharge is measured by a spectroscopic determination of concentration of complex formed by a titanium reagent and hydrogen peroxide, which is generated during the discharge. The results show no positive effect of addition of extra OH group to the reaction through the alcohols. The use of isopropylalcohol causes even a significant decrease in the amount of hydrogen peroxide generated. The subject of the second part is a comparison of effect of different electrode materials on the discharge. The efficiency is measured by the same method as in the first part. Materials chosen were stainless steel, platinum, aluminium, copper and carbon. Each material shows different hydrogen peroxide production rate under the same parameters. The most perspective material seems to be carbon, as an inert material, that can be expected not to initiate any decomposition of hydrogen peroxide. The least favourable appears to be copper. When used, no production of hydrogen peroxide was observed in one of the electrode parts of the reactor.
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Influence of pyrrolidone derivates on alkyd and polyurethane coatings.
Klímová, Edita ; Molliková, Eva (referee) ; Tulka, Jaromír (advisor)
The aim of this thesis was to append data on chemical resistance of coatings made of paints based on alkyd and polyurethane resins. In the theoretical part, relevant information on coatings, preparation of their systems, theory of solubilization and properties of solvents were collected and organized. Three N-derivates of pyrrolidone were chosen for the practical part. Their influence on particular alkyd and polyurethane coatings was studied with emphasis on time course of coatings degradation.
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