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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Metody pro hodnocení životaschopnosti Xanthomonas euvesicatoria po ošetření nízkoteplotním plazmatem / Methods for viability evaluation of Xanthomonas vesicatoria after low temperature plasma treatment

ZEMANOVÁ, Marta January 2017 (has links)
The thesis deals with methods for viability evaluation of the phytopathogenic bacterium Xanthomonas euvesicatoria after low-temperature plasma treatment. Low-temperature plasma produced by Gliding Arc experimental device was used for treatment of X. euvesicatoria. The viability of the bacterial cells was assessed using a scanning electron microscope (SEM) and by measuring of the fluorescence in the Smart-DART device using PrestoBlue chemical reagent. Methodology has been optimised for the sample preparation for the treatment by low temperature plasma and used for evaluation of applied methods. Lethal effect of gliding arc plasma to this gram-negative bacteria was verified by SEM which showed. There is significant structural changes on the cell surface. Viability assessment of X. euvesicatoria using Smart-DART device is a fast, time-saving and inexpensive evaluation of cell viability. The great advantage of this device is its ability to measure the fluorescence in real time. The disadvantage of this method is lower reliability in current stage of research.
2

Gliding Arc / Gliding Arc

KALA, Jaroslav January 2012 (has links)
The thesis is focused on increasing the surface tension of polyethylen, using plasma. A gliding arc was chosen for this surface modi cation. The theoretical part includes an overview of gas discharges, their classi cation, properties and technical applications, and deals with an in uence of surface tension on surface modi cations of materials. The experiment is explained in the practical part, a jet analysis carried out before the experiment is described. Results of the experiment are presented.
3

Využití atmosférického plazmového zdroje GA při ošetřování obilovin / Cereals treatment by using of GA atmospheric plasma source

HAVELKA, Zbyněk January 2013 (has links)
This thesis contains a brief summary of the theoretical applications of plasma discharges, and a description of the principle Gliding Arc plasma source. The practical part is focused on the research of the influence ofcereal seed treatment using plasma discharge on their nutritional value (dry matter, ash, protein and fiber). In the conclusion of this thesis is evaluation of the whole experiment.
4

Pokročilé oxidační procesy v environmentálních aplikacích / Advanced oxidation processes in environmental applications

OLŠAN, Pavel January 2013 (has links)
The aim of this thesis is the study of application of the synergistic effects of various advanced oxidation processes (AOP) used for decomposition of chemical compounds resistant to biodegradation. The synergistic effect of photocatalytically active material and low temperature plasma were tested in my thesis. Model substances with photocatalytically active material were exposed to atmospheric plasma discharge (Gliding Arc) in order to improve generation of the active hydroxyl groups and oxidation processes. The first chapter of the theoretical part summarizes the knowledge of advanced oxidation processes, their principles and utilization. Next chapters are dedicated to basic summary of titanium dioxide and types of creating the thin films. The last part of theoretical chapter describes the types of plasma discharges. The experimental part describes the equipment for decomposition of chemical compounds resistant to biodegradation using AOP. Next chapter of the experimental part is dedicated to decomposition of organic dye AO7 and antibiotic Verapamil hydrochloride. The last chapter summarizes the results of the experiments.
5

Etude des procédés plasmas dans l'élimination des polluants organiques persistants dans les effluents aqueux / Study of process plasmas in elimination of the persistent organic polutants in the aqueous effluents

Koyaouili, Thierry-Jocker 12 December 2016 (has links)
Ces travaux de recherche ont permis de comparer la performance de réacteur glidarc première et deuxième génération pour le traitement de l'eau polluée. Le réacteur DBD pointe/plan a été également développe. L'étude de caractérisation de transfert de matière dans les réacteurs glidarc ainsi que de l'efficacité énergétique ont montre que le reacteur glidarc de la première génération est plus performant que celui de la deuxième génération. La différence entre ces deux reacteurs est due par le temps de contact plasma solution et le phénomène transfert gaz-liquide. Notons cependant que la conversion du phénol est majoritairement réalisée avec les espèces nitrogènes. La modélisation numérique sous COMSOL a confirme le mécanisme de conversion du phénol propose. L'étude paramétrique d'élimination de l'acide acétique avec le réacteur DBD pointe/plan a montre que le générateur de haute fréquence (40 kHz) dégage énormément de chaleur qui contribue certainement au transfert de matière du polluant de la solution vers le gaz. il est donc envisageable d'apporter l'énergie petit a petit au système en utilisant le générateur de basse fréquence (500 Hz). / These research tasks made it possible to compare the performance of reactors gliding arcs first and second generation for the water treatment polluted. A reactor DBB point/plane was also developed. The study of characterization of transfer of matter in the rectors gliding arc as of the energy effectiveness showed that the engine gliding arc first generation is performent than that of the second generation. The difference between these two reactors must by the time of contact plasma solution and the phenomenon gas-liquid transfer. Let us note however that the conversion of phenol is mainly carried out with the species nitrogens. The numerical modeling under Comsol confirmed the mechanism of conversion of phenol proposed. The parametric study of elimination of the acetic acid with reactor DBD point/plane showed that the high frequency generator (40 kHz) releases enormously from heat which contributes certainly to the transfer of matter of the pollutant of the solution towards gas. It is thus possible to bring energy gradually to the system by using the low frequency generator (500 Hz) However, energy efficiency study has shown that low-frequency generator (500Hz) is more efficient than the high-frequency generator (40kHz). Which is justified by the fact that the energy consumed by the power of high-frequency generator is higher, making it uncompetitive.
6

Využití automatického robotického systému pro povrchovou úpravu materiálů / Use of automated robotic system for surface treatment of materials

PROLL, Jan January 2012 (has links)
In this thesis I deal with the project of a robotic apparatus that could be used for material treatment by using the gliding arc discharge as well as the appropriate design and choice of materials for the atmospheric pressure discharge jet with regards to a possibility of an industrial use. The input and output parameters were studied, such as the air flow regulation with regards to cooling, the design and choice of materials. Then I observed the temperatures near electrodes depending on the air flow. The applicability of the created atmospheric discharge was taken into account.
7

Studium produktů chemických reakcí v prebiotických atmosférách / Study of chemical reactions products in the prebiotic atmospheres

Manduchová, Ivana January 2018 (has links)
The diploma thesis is focused on the study of chemical reaction products in prebiotic atmospheres. The theoretical part deals with the main theories of composing the atmosphere of the early Earth, hypotheses of the origin of life and genetic code in the form of RNA, the atmosphere of the moon Titan and the basic characteristics of the gliding arc discharge, and the analytical techniques used in the diploma thesis. In the experimental part, study of products was carried out by experimental atmospheric simulations in a special stainless steel reactor in various mixtures of gases N2, CH4, CO2 and O2. The electrical discharge for atmospheric simulation was generated by an electrode configuration for the gliding arc discharge and glow discharge. Detection and identification of chemical reaction products was performed by Gas Chromatography with Mass Spectrometry (GC-MS) and Flame Ionization Detector (GC-FID), Testo 350 M/XL and Proton Transfer Reaction Mass Spectrometry (PTR-MS). A theoretical kinetic model was created to predict and confirm the detected products. During the experiments, the dependence of the product intensity on changes in the composition of the gaseous mixture and the applied value of the electric current was also observed.
8

Studium rozkladu těkavých uhlovodíků v nerovnovážném plazmatu klouzavého obloukového výboje za atmosférického tlaku / Study of volatile hydrocarbon decomposition in non-thermal plasma of gliding arc at atmospheric pressure

Töröková, Lucie January 2008 (has links)
Diploma thesis deals with gliding arc discharge in non-equilibrium plasma, its properties and usage for dissociation of volatile organic compounds. Plasma techniques create a perspective alternative to classical methods such as adsorption, biofilters, thermal processes, freezing and condensation. The method used for analysis of dissociation products is described in the theoretical part as well. Method is gas chromatography and it is combined with mass spectroscopy. The experimental part contains the overall description of GlidArc reactor where volatile organic compounds were dissociated. The volatile organic compound is brought into the reactor from the reservoir by carrier gas (nitrogen); synthetic air was used as working gas. The reactor is connected to the device for sampling. This device has several openings for sampling by SPME fibre method, sorption tubes method and a special opening for probe entry from the device Testo 350 M/XL, which enables instant analysis of low-molecular compounds. GC-MS was used for determination of high-molecular products of dissociation. Products sorbed on SPME fibres were analysed directly, compounds sorbed by active carbon were extracted by carbon disulphide. Samples obtained using SPME fibres were analysed. The major products of the dissociaton were found due to this analysis, those major products are in the case of hexane: pentanal, 4 methyl-3-pentanal, 2-butoxy-ethanol, pentane a 2-hexene. Major products detected when dissociating cyclohexane were: l,3-dimethyl-butane, propanal, cyklohexanone, 5-hexenal a 2-pentyn-1-ol. Major products of xylene dissociation were methyl-benzene, benzaldehyde, 4-methyl-benzaldehyde, 1-nitroethyl-benzene a benzenmethanol. After analysis obtained using sorption tubes showed that mainly the dissociated compound was sorbed, but the products of the dissociation were presented in too low concentration for an adequate analysis. For that reason the sorption tubes were used only for quantitative determination of the compounds depending on the power supply. The dependence of the dissociation of the compounds on the power supply was observed using SPME fibres which were used for quantitative determination. The Results obtained by both obtained techniques were almost in accordance. Speaking of low-molecular compounds, dissociation of all compounds gave the same products, i.e. carbon dioxide, hydrogen, nitrogen oxide, nitrogen dioxide and water. The results show that the dissociation of VOC gives - besides many potentially dangerous dissociation products - significant amounts of nitrogen oxides which is harmful to the environment. Hence it is necessary to be concerned with problems studied in the future mainly with respect to limitation of NOx generation. It will be possible to optimalize the conditions of the VOC dissociation on the basis of future kinetic analysis.
9

Studium působení plazmatu na roztoky chininu / Study of plasma effects on quinine solutions

Procházková, Michaela January 2020 (has links)
This diploma thesis focuses on quinine solutions and quality of these solutions after applying plasma discharge. These electric discharges can be used to destroy some substances from the water. The theoretical part is focused on description of electric discharges in liquids and on the properties of quinine. In the experimental part, the properties of quinine solutions containing different electrolytes were analysed by UV-VIS spectrophotometer and fluorescence spectroscopy. Two different types of configurations of plasma discharges in liquids were used. Solutions were compared on the base of different concentration of quinine, different electrolytes, different configurations of plasma discharges and pH values of the solutions. Furthermore, the experimental work focuses on quinine solutions with the sodium nitrate. The time instability of the solutions was analysed. Also, the influence of the solution age and different types of the plasma discharge on the excitation and emission spectra of quinine were investigated.

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