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Study on the influence of plasma activated water on seed germination
Vozár, Tomáš ; Zlámalová Gargošová, Helena (referee) ; Kozáková, Zdenka (advisor)
This bachelor thesis deals with study on the influence of plasma activated water on wheat seed germination. After interaction with the plasma, the water changes its composition and obtain new properties that are useful in agriculture. The theoretical part is divided into two parts. The first part of the theory is dealing with basic knowledge about plasma, its properties, and possibilities of plasma generation in laboratory conditions. In the second part, the work deals with plasma activated water – PAW. The preparation of plasma activated water is described in details as well as its physical-chemical properties and composition with respect to the PAW possible applications. The aim of the experimental part of this work was to prepare plasma activated water in three different plasma systems and apply it on wheat seeds. These three ways of activation used direct and indirect interaction of plasma with water surface. After the seeds were germinated, the influence of plasma activated water on seed germination and quality of crops was observed and compared to control samples. The influence of different ways of water activation was also evaluated. Results show positive effects of plasma activated water on the seed germination and it also increased the quality of crops. Next steps in this research should be the transfer of this experiment from the laboratory scale on the Petri dish to the pot experiments in soil.
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Plasma activated water prepared by electrical discharge in liquids
Možíšová, Aneta ; Krčma, František (referee) ; Kozáková, Zdenka (advisor)
The aim of the diploma thesis is generation of active particles in plasma activated water (PAW) using a low-temperature plasma discharge. In this work I focus on the determination of hydrogen peroxide, nitrites and nitrates as active particles. The practical part is focused on a specific case of use of a plasma discharge in selected electrolytes dissolved in an aqueous solution. Here, three phosphates, differing in the number of acidic hydrogens, were selected for each experiment, and sodium chloride and tap water were compared for comparison. Phosphates were selected for their stable pH during plasma discharge in solution to monitor the effect of pH. The experiments were focused on investigating the stability of active particles in PAW, under which conditions is the highest production rate of these particles and what effect the pH value has on the result. It was found that hydrogen peroxide is generated the most in an alkaline environment but shows better stability in neutral. The concentration of generated nitrites is not high, but it shows stability, regardless of the polarity of the main electrode used for PAW generation. Nitrites were generated the most in alkaline environment and nitrates in acidic environment. One of the conclusions is that nitrates are not a very stable particle in PAW. Thanks to the activation and oxidation properties of plasma activated water, this method can be used in medicine or agriculture
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Study of plasma activated water influence on soil microorganisms
Poláková, Marianna ; Dvořáčková,, Helena (referee) ; Krčma, František (advisor)
Bachelor thesis is focused on the impact of plasma activated water on soil microorganisms. Reactive spieces of oxygen and nitrogen are present in plasma activated water, which are responsible for its biological and chemical properties. Thanks to its unique features, plasma activated water is used for therapeutic purpose or in agriculture. The theoretical part is concentrated on general information about soil, its properties and microorganisms found in it. Furthermore, it deals with basic information about plasma and sources used for its production. The last part presents the plasma activated water and its specific characteristics. Experimental part deals with the application of distilled water, plasma activated water and a mixture of distilled and plasma activated water on soil. In the first set of experiments, it was an application directly on the soil, the application to the soil extract was in the second set. Bacteria were inoculated on culture medium in concentrations 10-2, 10-4 and 10-6. The number of formed colonies was observed and then some microorganisms has been identified. Based on the results, it can be stated that plasma activated water had a positive effect on the microorganism colonies growth. However, the subject of further work will be to determine whether it is positive for pathogenic microorganisms or not.
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Preparation and characterization of plasma activated water for bio applications
Lemonová, Hana ; Matěj,, Klas (referee) ; Krčma, František (advisor)
The aim of this master thesis is the preparation and characterization of plasma activated water (PAW) prepared by dielectric barrier discharge at atmospheric pressure in air for the future applications in agriculture and medicine. The theoretical part is focused on plasma activated water and its effects on seeds and plants. The work also deals with the preparation and application of PAW in the world. Various types of plasma discharge configurations suitable for its preparation are described here. In the experimental part of the master thesis, distilled and tap water were chosen for activation. The concentrations of active particles in PAW generated by DBD such as nitrites, nitrates and hydrogen peroxide were determined. The value of the concentration of active particles changes probably due to mutual interactions when nitrites are oxidized by hydrogen peroxide to nitrates. Physical properties of PAW such as conductivity and pH were also characterized. After the preparation of PAW, the conductivity increases due to the increase in the concentration of active particles formed by dissociation and ionization of water molecules by plasma. The particles presented in the air, which are dissociated and ionized by plasma, also diffuse into the liquid, and contribute to this increase. The decrease in pH also corresponds to an increase in the concentration of hydrogen ions and the formation of nitric acids. Another aspect of this work was to study plasma activated water during the first eight hours after its preparation and to determine its properties. We have found that PAW prepared from tap water retains its characteristic properties for at least 8 hours and distilled water for 6 hours. In the master thesis, the analysis of plasma discharge was performed using optical emission spectroscopy. OES measurements were performed in the wavelength range 300 to 800 nm. The second positive nitrogen system (N2 (C 3u) N2 (B 3g)) and the first positive nitrogen system (N2 (B 3g) N2 (A 3+u)) were identified in the overview spectrum. Molecular nitrogen ions, OH· radicals, atomic oxygen and atomic hydrogen can be observed in the spectrum, too. The dielectric barrier discharge was also captured using a high-speed camera, and the recording shows the occurrence of multiple discharges that are spatially as well as temporary unstable.
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Characterization of plasma activated water for biomedical applications
Šindelková, Kateřina ; Dzik, Petr (referee) ; Kozáková, Zdenka (advisor)
The aim of this master thesis is to characterize plasma activated water (PAW) prepared in various plasma systems using direct and indirect interaction of plasma with liquid or its surface. Plasma was generated by electric discharges at atmospheric pressure. The prepared plasma-activated water was studied with respect to its use in biomedical applications. The theoretical part deals with plasma activated water. It contains a description of the PAW preparation, its characterization in terms of produced particles or its physico-chemical properties. Also, methods for antimicrobial activity estimation or colorimetric determination of produced particles are described in this section. In the experimental part of this work, the types of discharges that were used for the PAW preparation and their comparison are presented. Two types of liquids were selected for the activation, namely distilled and tap water. Subsequently, concentrations of selected reactive particles in PAW (hydrogen peroxide, nitrates and nitrites) produced in three different plasma systems were determined. Besides the comparison of reactive particles production in various systems, their time stability was studied as well. Over time after the PAW preparation, the values of active particles concentrations have changed due to mutual interactions between the particles. Mainly, nitrites were oxidized to nitrates or vice versa depending on the PAW type and other conditions. Part of the work was also monitoring selected physical properties of PAW, namely pH value and specific conductivity. It has been found that PAW does not retain its activated properties for too long, depending on the type of preparation and methods of storage. Therefore, one of the important goals of this work was to determine and compare suitable storage conditions for PAW with respect to its potential biomedical applications.
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Hydrogen peroxide generation by the microwave plasma jet
Staškovanová, Denisa ; Mazánková, Věra (referee) ; Kozáková, Zdenka (advisor)
This Bachelor thesis deals with the generation of hydrogen peroxide by the microwave plasma jet in distilled and tap water. The main goal was to characterize the amount of generated hydrogen peroxide depending on various experimental conditions and to determine its stability. A titanium reagent was used to determine if hydrogen peroxide was present in the sample. The method for determination of hydrogen peroxide concentration was spectrophotometry. In conclusion, differences in the concentration of hydrogen peroxide are formulated according to the change in experimental conditions, its stability in plasma activated water and stability in complex with the titanium reagent. Differences between the generation in distilled and tap water are also described.
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Comparison of plasma activated water quality prepared by different plasma systems
Staškovanová, Denisa ; Krčma, František (referee) ; Kozáková, Zdenka (advisor)
This diploma thesis deals with generation of reactive species (hydrogen peroxide, nitrates, nitrites) using various plasma systems in distilled and tap water. Prepared plasma activated water differs in the way the plasma is applied, namely plasma above the water surface, plasma inside water or bubbling of plasma gaseous products into water. The main goal is to determine the amount of species produced in different plasma systems and compare them with each other. The effect of ozonizer experimental conditions on the generated amount of reactive species is also monitored.
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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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Assessment of the ecotoxic effect of plasma-activated solutions
Belisová, Mária ; Šimečková,, Jana (referee) ; Zlámalová Gargošová, Helena (advisor)
This master‘s thesis deals with ecotoxicity assessment of plasma-activated solutions. Various plasma-activated solutions were prepared in the experiments. In the vast majority of tests, it was plasma-activated tap water – PAW. Depending on the test organism, dilution water was further processed, namely dilution water for Thamnocephalus platyurus and Daphnia magna. In this master‘s thesis the ecotoxicological effects were assessed through aquatic ecotoxicity tests with an aquatic plant Lemna minor, on a crustaceans T. platyurus and D. magna and on agricultural crops Lactuca sativa and Allium cepa L. . Crustaceans are fresh-water organisms on which the water contamination can be quickly and quite easily assessed. These plasma-activated solutions were also tested for acute ecotoxicity of soil organisms by ecotoxicological contact tests with Eisenia fetida, springtails Folsomia candida and seeds of L. sativa. Tests on T. platyurus and D. magna were performed in time intervals and a change in mortality was observed depending on PAW concentration. If the test results allowed, the LC50, IC50, A and NR escapism values were calculated. When the measured and calculated values did not allow such a calculation, the overall effect of PAW on organisms was assessed and a significant difference was calculated for the L.sativa root growth inhibition test. The final results showed that PAW has an ecotoxic effect on aquatic organisms, while it has rather beneficial effects on terrestrial organisms.
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Study of plasma activated water influence on soil microorganisms
Lungová, Tereza ; Šimečková,, Jana (referee) ; Krčma, František (advisor)
The bachelor thesis deals with the effects of plasma activated water on microorganisms found in the brown earth sample. The theoretical part is divided into two parts. The first part focuses on the analysis of soil and microorganisms living in it. The second part deals with the general properties of plasma and the formation of plasma-activated water. In the experimental part of this work, plasma-activated water was applied to the leachate of soil microorganisms and also directly to a selected soil sample in various concentrations. Subsequently the effect on the viability of soil microorganisms and the composition of soil microorganisms was observed. Based on the results from the practical part, it was found that plasma-activated water has no significant positive or negative effect on soil microorganisms. For this reason, it will be necessary to focus on specific types of microorganisms in further research.
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