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Utilization of hydrodynamic cavitation for water treatment
Balko, Marek ; Kozák, Jiří (referee) ; Rudolf, Pavel (advisor)
This bachelor thesis deals with the observation of features of cavitation with emphasis on the hydrodynamical cavitation and its use for eliminating unwanted and badly degradable compounds from water. Thanks to high temperature and pressures that are present at a colapse of cavitation bubbles the water decomposes into highly reactive hydroxile radicals which are able to decompose even. This effect can furthermore be strenghtened by the use of advanced oxidation processes – AOP. The experimental part of thesis is dedicated to examining a ability of hydrodynamical cavitation degrade particular chemical substance from water, namely estrogen.
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Mechanical properties of cell membranes
Pírková, Marcela ; Pochylý, František (referee) ; Fialová, Simona (advisor)
This thesis is a research character focused on the analysis of mechanical properties of cell membranes. The main aim is to find methods that will break the structure of the membranes. In addition, the thesis deals with the microorganisms living in the reservoirs of the Czech Republic, the existing methods of water purification and the specific properties of microorganisms membranes. In the experimental part there is an attempt of hydrodynamic cavitation, the whole process is tested on biomass of cyanobacteria.
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Application of cavitation in industrial processes
Hamar, Oliver ; Tancjurová, Jana (referee) ; Rudolf, Pavel (advisor)
The bachelor thesis deals with the research of the application potential of cavitation technologies in various industries. Thanks to its properties, cavitation seems to be a promising tool for streamlining a large number of industrial processes in several aspects. The first part deals with the theoretical description of the cavitation phenomenon, its negatives and methods of their detection. The second part focuses on the analysis of possible usage areas of cavitation technologies and the ways of generating the cavitation, focusing on current research and findings in the area of hydrodynamic cavitation application.
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Dynamics of cavitating flow behind the orifice
Kubina, Dávid ; Kozák, Jiří (referee) ; Rudolf, Pavel (advisor)
Cavitating flow through five perforated plates with different number of holes with preserved constant flow cross-section area in sum were experimentally examined. Dynamic characteristics such as dependence of pressure amplitudes and dominant frequencies on cavitation number in all regimes of cavitating flow: incipient cavitation, partial cavitation, fully developed cavitation and supercavitation are obtained. For determination of dominant frequencies several pressure transducers in two regimes of measurement were used. Results were validated with frequency spectra obtained from picture analysis based on high-speed camera records.
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Cavitating flow in perforated disc
Kubina, Dávid ; Kozák, Jiří (referee) ; Rudolf, Pavel (advisor)
The main goal of this bachelor thesis is to measure hydraulic characteristics of five round plates perforated with several circle orifices installed in the pipeline. The main condition was to preserve constant cross section of the holes in sum. Theoretical part of the thesis is focused on the basics of hydrodynamic cavitation and its practical usage in the industry. The experimental part of the paper deals with hydraulic characteristics of each shield perforated by varying number of orifices and also includes mutual comparison. Also high speed camera was used to detect the length of cavitation zone, although these results are not included in the conclusion of the thesis.
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Venturi nozzle shape influence on hydrodynamic cavitation
Mračko, Patrik ; Balko, Marek (referee) ; Rudolf, Pavel (advisor)
Thesis focuses on the influence of various differently shaped diffusers of Venturi nozzle on the cavitation, which occurs during flow of liquid through said nozzle. Several models with different shapes of diffuser's wall were designed. Cavitation in these models was then investigated with numerical calculation. Two physical nozzles were made according to designed models and tested on experimental circuit. As part of the experiment, the cavitation inside the nozzles was measured with flow of liquid corresponding to a large range of cavitation numbers. Results of this experiment were used to determine which model of the nozzle is more effective in creation of a cavitating flow.
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Dissolved gas effect on hydrodynamic cavitation
Piňos, Ondřej ; Fialová, Simona (referee) ; Rudolf, Pavel (advisor)
Thesis is focused on hydrodynamic cavitation in gas saturated liquid flowing in microfluidic circuit with Ventruri noozle. Thesis describes theoretical base in fields of: gas saturation of liquids, cavitation inception, diffusion mechanisms and cavitation collapses. In practical part experiment on microfluidic circuit was done. In pressurised tank liquid was saturated by gas, after letting the mixture into noozle we observed beginning of cavitation by acoustic and visual way. Inception of cavitation was also observed by -\sigma graphs. With increasing pressure in tank we observed developed cavitation, its persistivity was compared with increasing amount of gas in liquid. Measured values are supported by theoretical part of thesis. There was nonconformity in comparison of demineralised water and tap water saturated by air, where demineralised water cavitated during higher cavitation numbers for saturating pressures of 4 and 6 kPa. Further research could focus on undersaturated water as well as on better control of water properties, especially on number of nuclei within.
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Application of hydrodynamic cavitation in brewing
Štěrba, Jiří
The aim of this work is to apply these advantages in the brewery industry. In the field of beer brewing, we would like to investigate several phenomenona, such as the isomerization of bitter hop acids, the reduction of gluten concentration or the cell-walls breakdown.
Plný tet:  PDF
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Study of plasma activated water properties
Maďarová, Štefánia ; Trunec, David (referee) ; Mazánková, Věra (advisor)
ABSTRAKT The goal of the diploma thesis was to carry out professional research focused on the formation of chemically active particles in plasma and their identification. The experiment was performed for the preparation of plasma activated water (PAW), using a hydrodynamic cavitation plasma jet device (HCPJ). The main goal of the experimental part of the thesis was the analysis and determination of the concentration of active particles generated during the experiment. The active particles I dealt with in my work were nitrates, nitrites and hydrogen peroxide. Samples of commercial (Danube) water, treated distilled water, treated tap water and treated Mixbed water were analysed. In addition to the production of reactive particles, their temporal stability was also studied. The samples were stored at room temperature. As the samples aged, the concentration values of the active particles changed due to mutual interactions between the particles, when nitrites were oxidized to nitrates. Physical properties of PAW, pH value and conductivity were monitored in the work. After PAW preparation, the conductivity increases due to the increase in the concentration of active particles created during the dissociation and ionization of water molecules by plasma treatment. The particles present in the air contribute to the increase in conductivity, they dissociate and ionize the plasma, which diffuse into the liquid. A drop in pH is the cause of an increase in the concentration of hydrogen ions and the formation of nitric acids. It was found that PAW does not retain its activated effects for too long, with aging the concentration of active particles decreased. The theoretical part is focused on plasma-activated water, its preparation, produced particles and their stability. The work also describes the use and application of PAW in agriculture, biomedicine and other industries. Various types of plasma discharge preparation are described. I also deal with the preparation of Mixbed water from Danube water. In the diploma thesis, we analyzed the plasma discharge using optical emission spectroscopy (OES). The measurement by OES was in the range of wavelengths from 200 to 1100 nm. The measurement by OES was in the range of wavelengths from 200 to 1100 nm. In the overview spectrum using tap water measured in the visible region, H-alpha, H-beta, H-gamma can be seen.
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Removal of organic pollution using advanced oxidation processes
Přibilová, Petra ; Kučerík, Jiří (referee) ; Chýlková, Jaromíra (referee) ; Opatřilová, Radka (advisor)
The presented doctoral thesis deals with the use of advanced oxidation processes combining hydrodynamic cavitation (HC) to produce hydroxyl and sulfur-based radicals. The investigated micropollutants are selected natural estrogens estrone (E1), 17-estradiol (E2), estriol (E3) and synthetic 17-ethinylestradiol (EE2). The theoretical section includes information on the properties of estrogens, their occurrence and effects in the environment on non-target organisms across trophic levels; and list of options for their removal from wastewater. The advanced oxidation processes themselves are also discussed and current knowledge in this area is summarised. In the research section, used analytical methods (LC-MS/MS and spectrophotometry), designs of individual experiments and results of tested processes are described. In addition monitoring the efficiency of different combinations of hydrodynamic cavitation and other agent and the suitability of the materials used on the experimental unit were also investigated. The sorption/desorption onto the surface of selected plastic materials (SBR, EPDM, PTFE, Tygon S3TM, PVDF and PVC) was also evaluated. Based on the results, the material for the unit - on which the degradation experiments were carried out - was selected. The methods chosen for the removal of estrogens from water were HC/H2 O2 , HC/O3, HC/percarbonate, HC/persulfate, hydrodynamic cavitation alone, and H2O2 alone. The design of the experiments was created to minimize the time required to treat the water, ideally one cycle per unit (4 seconds), which corresponds to the flow-through arrangement of the system.
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