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Inkjet prints ageing by ozone and light
Pasečná, Klára ; Jančovičová, Viera (referee) ; Veselý, Michal (advisor)
This thesis is focused on the effect of ozone on ink-jet prints. The knowledge about print technologies, materials for ink-jet printing, influence of environmental factors on the prints degradation and the methods of print lifetime estimation are discussed in the theoretical part of the thesis. Test-charts of 108 samples of C, M, Y primary colours and their overprints were prepared. I used two types of papers designed for ink-jet printing. These samples were exposed the effect of ozone in various concentrations to perform an accelerated aging experiment. Optical density values, La*b* coordinates, colour difference values were calculated from the measured spectral data. Changes of colours of the ink due to ozone exposure were determined and discussed. The validity of the reciprocal law due to ozone exposure was studied, too. The reciprocal behaviour was not confirmed for both types of the studied papers.
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The application of chlorine for public swimming pool water disinfection
Wagnerová, Andrea ; Svoboda, František (referee) ; Biela, Renata (advisor)
The bachelor thesis focuses on issues surrounding disinfectants of swimming pool water. The dissertation examines various chlorine based disinfectants as well as chlorine free disinfectants. Part of the thesis compares advantages and disadvantages of different possibilities of securing hygienic swimming pool water. Several complexes of public swimming pools in Brno and its neighbourhood were visited in order to examine the methods of disinfection, which are currently used at those swimming pools. Disinfectants based on chlorine are currently used the most for swimming pool water.
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Barrier properties of varnishes for protection of photographs
Lokotschová, Radka ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
In this diploma thesis the basic principles of inkjet print, ink composition, print media and degradation mechanisms of ink dyes are summarized. The thesis deals with study of varnish barrier properties in coloured inkjet prints. Permeability of water vapour and oxygen (parts of atmosphere) depending on different coatings are tested there. In addition the influence of ozone on degradation of dyes was studied, while ozone was permeating through barrier varnish layer of inkjet print. Ozone plays an important role in degradation processes of the inkjet prints and it also causes a gas-fading. Concentrations of acting ozone were established by iodometric titration. Simultaneously kinetics of degradation of Orange 7 was studied on indicator papers.
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Generation of ozone by photochemical processes in CO2
Kucserová, Aneta ; Salyk, Ota (referee) ; Mazánková, Věra (advisor)
The bachelor thesis deals with the measurement of ozone concentration, which was produced by dielectric barrier discharge, corona discharge and UV lamp. The concentration of ozone in the air was also measured. The theoretical part deals with the basic properties of ozone, its use and determination of concentration by various methods. In the experimental part, ozone generation is described by the above-mentioned discharges.
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Assemblage and testing of the device for water ozonizing and its application for silicon wafer cleaning
Ředina, Dalibor ; Mikulík, Petr (referee) ; Voborný, Stanislav (advisor)
Deionised-ozonated water, so-called DIO3 appears to be an ideal alternative for usage in semiconductor industry. The utilisation of DIO3 for removal of photoresist from silicon wafers is faster, cheaper, and more environmental-friendly compared to classical technology based on mixture of sulphuric acid with hydrogen peroxide, so-called SPM. The diploma thesis deals firstly with research into ozone and ozonated water and their possible applications. Next sections describe two prototypes of generators for DIO3, that were assembled in CSVG a.s. Testing of parameters for generators on dissolved-ozone concentration is also a part of this thesis. Moreover, thesis involves tests, that were carrier out in ON Semiconductor in Rožnov pod Radhoštěm. These tests compare efficiency of cleaning by classical technology based on SPM and DIO3 approach.
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Survey of kinetics of spontaneous ozone decay in water
Fendrych, Adam ; Mergl, Václav (referee) ; Mega, Jaroslav (advisor)
In the general part of this diploma thesis are presented technical information collected on the issue of spontaneous decay of ozone in water solution and problems with analytical monitoring of these processes. Particular attention is paid to influence of pH value, bicarbonate and peroxide concentration on ozone decay kinetics. Experimental part is focused on the use of spectrophotometry in the study of chemical reactions associated with the spontaneous decay of ozone in distilled and tap water depending on pH and temperature after saturating of water by ozone prepared from air and pure oxygen. Direct photometry in UV range of spectrum (at 260 nm) was used to monitoring of ozone decomposition kinetics.
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Design and Operation of Water Disinfections Plants
Krupicová, Simona ; Rajnochová, Markéta (referee) ; Kučera, Tomáš (advisor)
In the first part of my bachelor thesis I deal with individual disinfectants used for hygienic supply of drinking water based on chlorine and without chlorine. Then I mention the operation without chlorine disinfectants. In the second part of this thesis I describe individual plants using various disinfection methods and at the end of the thesis I compare these methods and use it in practice.
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Use of active oxygen for car air conditioning cleaning
Zapletal, Adam ; Dřímal, Jiří (referee) ; Štětina, Josef (advisor)
The diploma thesis deals with the cleaning of car air conditioning system with ozone. The aim is to design equipment for ozone production, its location and cleaning algorithm. The thesis is divided into two parts. The introductory theoretical part describes the principle of operation of conventional automotive air conditioning, then discusses the methods of pollution and solutions to remove these pollutions. The theoretical part ends with a summary of information on ozone. The practical part is continuously followed by the design of device for the ozone production directly in the car. The final part deals with the location of such a device in a car, measuring its parameters and evaluating the results.
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Temperature influence on ozone generation and decomposition on solid surfaces
Krejsková, Eliška ; Dřímal,, Jiří (referee) ; Kozáková, Zdenka (advisor)
This master’s thesis is focused on a study of temperature influence on ozone generation and decomposition by chosen solid surfaces. Ozone is unstable gas that is decomposed spontaneously. This decomposition can be accelerated by various factors such as increase in temperature or reaction with other substances. The aim of this study is to determinate how fast the ozone decomposition proceeds at different temperatures and how the homogenous decomposition of ozone is accelerated by heterogeneous processes on the walls of solid materials. Currently in practise ozone is used in many areas and the finding of the rate of its decomposition can help to increase efficiency of its production and subsequent specific applications. In the theoretical part of the thesis, these points are described: important properties of ozone, possibilities of its utilization, the ozone generation, some methods of determination of the ozone concentration, ozone relationship to various solid surfaces and present theoretical knowledge about the effect of temperature on the ozone generation and decomposition. In the experimental part, the rate of the ozone decomposition in reaction tubes made of copper and iron of two different surface to volume ratios was investigated at temperatures of 10, 25, 40, 55, 70 and 85 °C. Ozone generated from oxygen was closed in the reaction tube and the decrease of its concentration during the time was observed by absorption spectroscopy. From obtained exponential dependencies, the rate constants at different conditions of this experiment were evaluated. The rate of ozone decomposition significantly increased with higher temperature. The fastest ozone decomposition took place in the iron tube of larger inner diameter (8 mm).
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Degradation of Inkjet Printouts
Stančík, Jiří ; Kaplanová, Marie (referee) ; Čeppan, Michal (referee) ; Veselý, Michal (advisor)
Inkjet printing technology became a popular technology for printing digital photographs in the last decade. There is a big variety of both original and alternative (cheaper) inks and print media for the consumers. But there is a question if the cheaper material provides also comparable printout quality. For this reason, it is important to test the properties of such inkjet printouts. There are several ways how to test the lightfastness of the printouts: long term storage under environmental conditions, or short, accelerated ageing tests. The stability of printouts is affected by many factors, such as ink-receiving layer, ink composition, UV and visible light intensity and air pollutants concentration in the environment. Some inkjet printouts exposed to light usually undergo surprisingly fast fading, but light is not the only dangerous condition for inkjet printout. The two types of test targets printed with dyebased inkjet inks on various paper types were subjected to both accelerated test in a xenon test chamber and light and environmental pollutants long-term test in a sunny indoor corridor. The values of light intensity were continuously monitored and samples properties were regularly measured with a spectrophotometer. Another type of testing included accelerated ozone ageing of inkjet dyes. The colour gamuts and gamut volumes were calculated from collected spectral data. Total colour difference E*ab was also evaluated, its increase served as a tool for finding the formal printout degradation rate constant. It was found out that the dyes in ink-receiving layers of printouts underwent significant degradation in all tested conditions. The degradation rate depended on the type of used print media. The reciprocity behaviour of printouts was also studied. Recent inkjet printouts testing miss some actual ISO norm which should show the way of effective lightfastness evaluation. One of the main aims of this work was to find some new and alternative ways of inkjet printouts lightfastness evaluation. The method of printed inks concentration determination from the test charts spectrophotometric measurements was also proposed.
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