This diploma thesis follows the degradation of inkjet print by ultraviolet radiation and ozone effect for different types of papers. Colour test charts for the evaluation of accelerated ageing effect of ultraviolet light and gas fading were designed. These test charts were printed by dye-based inks on selected receiving media and exposed to ozone-enriched environment, UV radiation and their combination. The colorimetric values L* a* b* were calculated from spectral data of all patches of the test charts. The ozone effect on the prints was evaluated in the terms of total colour difference and dye concentration. The degradation of dye caused by ozone was observed also in a long-term period, after the contact of sample with ozone was terminated. Results of printed samples accelerated ageing by UV radiation and those that were influenced by the ozone effect were evaluated in the same way. It was found out that UV radiation and ozone treatment have a different effect on the degradation of dyes. The degradation rate is also strongly influenced by the receiving layer composition of papers used for inkjet printing. Also the catalytic effect of dyes was evaluated.

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.

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.

This diploma thesis deals with the impact of pollutants on colour photography made by inkjet printing technology. There are summarized basic principles of inkjet printing, composition of inks and negative factors influencing the printout quality. The ozone was studied in the experimental part, because it has the stongest degrading effect of all common pollutants. The accelerated ageing test with changing the concentration of ozone and the time of exposure was performed. The test scales were made by using two different inks. The L*a*b* values and optical densities of selected fields were calculated from the reflectance spectra of 918 colour fileds. The colour gamut and its volume were calculated from the L*a*b* values. The changes of colour gamut volume correlated with the changes of optical densities. It emerged that using the colour gamut as the instrument of evaluation of the inkjet printout dyes degradation rate is eligible and it is suitable to recommend this method for the ozone accelerated tests.

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).

This diploma thesis is occupy by assesment optimum method straining of tyres and then constructional concept of test cell for ozone degradation of rubber tyres with sizes from 13” to 15”. The final aim of this diploma thesis is construction of test cell which is based on choice of optimum method straining of tyres. The next output of this diploma thesis is concept of unit for ozone degaradation of tyres.

Relationship between the UV index and selected parameters Abstract Ultraviolet radiation (UV radiation) is a shortwave radiation with wavelengths from 100 to 400 nm. This radiation has both positive and negative effects on living organisms and human health. Therefor the so-called UV index (UVI), characterizing the biological effect of UV radiation on human health was defined in 1994. This thesis aims to evaluate the link between selected factors (total ozone column, solar elevation angel, cloudiness and altitude) and the UVI values. Observed data at four stations in Czechia (Hradec Králové, Košetice, Kuchařovice, Labská bouda) and SYNOP reports from the four nearest stations during the period 2010−2017 were used. The Sun elevation (angle of Sun ray) has the strongest effect on the UVI values. The highest UVI values are generally reached at high angels when the Sun rays go the shortest path through the atmosphere. The increase of the UVI is exponential, from an angle of 30ř the increase is approximately linear. The UVI values increase on average by 0.8 at the Hradec Králové station and by 0.9 at the Labská bouda station for angle increasing by 5ř. The effect of clouds is significant and depends on the height and the clouds amount. High level clouds reduce UVI negligible, overcast sky by only 15 %. Medium and...

This diploma thesis is focused on the study of the influence of advanced oxidation processes on degradation of organic dyes. The field of AOP – very effective physically-chemical methods of wastewater treatment – includes application of strong oxidation agents, UV and ionizing radiation and electrical discharges. For this thesis, two of these methods were chosen – the application of oxidation agent (ozone) and UV radiation. Along with electrolysis, which is mentioned rather marginally in this thesis (it is the subject of the previous thesis), these phenomena are products of electrical discharge in water, where they participate in the processes of degradation in a different way. For all measurement series, two direct azo dyes were chosen as model substances – C.I. Direct Blue 106 and C.I. Direct Red 79. The ozonizer, in which either oxygen or synthetic or technical air were loaded as carrier gases, was used for degradation of dyes by ozone. The generated ozone was loaded into the bubbling vessel with dye solution of different initial concentration (10–130 mg.dm-3), which was followed by other bubbling vessel with KI solution for the next analytical determination of the amount of generated ozone. The other parameters changed were the gas flow (1–2 dm3.min-1), ozonizer output (minimal and maximal), type of dye, pH value of the solution (neutral or acid) and additional electrolyte (NaCl, Na2SO4 or any). The reactor for the study of the influence of UV radiation on degradation of dyes was an UV sterilizer into which the equivalent volume of dye solution was added. The possibilities of experimental settings were limited and only the type of dye, an additional electrolyte and pH value of the dye solution were adjusted (as in the case of ozone). Several series of samples were measured with various input conditions which more or less influenced the degradation of investigated dyes in this experiment. It was found that for both used methods the Direct Blue 106 dye was more degradable (with significantly better results for ozone than for UV radiation). The degradation of Direct Red 79 dye proceeded only by ozone treatment, in the case of the application of UV radiation no degradation occurred. By investigation of the influence of initial concentration of dye on its degradation, it was confirmed that with the initial concentration enhancement the final concentration rises as well, whereas in low concentrations (10–50 mg.dm-3) the initial concentration has no effect. The addition of an electrolyte had an accelerating effect on dye degradation in both methods (NaCl and also Na2SO4 showed similar results though the degradation proceeded in different ways). The addition of HCl accelerated the degradation only in the case of UV radiation; during the application of ozone the pH level of the system did not have any influence on the degradation. Oxygen and synthetic air had the strongest effect on ozone degradation (comparable results); in the case of technical air the final dye concentration was higher up to 30 %. The gas flow of 1.5 dm3.min-1 was stated as optimal with the ozonizer output 30 W (maximal). At minimal power the ozonizer produced very low amount of ozone.

The main content of of this thesis is a construction design and analysis of a machine for cutting tires. The resulting solution emerges from the design options and the option that meets the best selection criteria is chosen. Then the thesis stops for a while at the choice of cutting technology and tries to exemine its suitability for cutting tires. In its other part there is an attempt to clarify the relevant parts of the machine, where the benefits of three-dimensional views is used. Basic design and check calculations are done in the selected machine parts.