Conjoint analysis is a popular method in consumer preferences research. One of the factors that caused the increasing popularity of this method in recent years is wide use of hierarchical Bayesian models which has been found invaluable in solving the problem of how to obtain reliable estimates of individual preferences without need for overloading respondents with too many conjoint tasks. First goal of my dissertation was to confirm whether the use of Bayesian models is the best choice under all circumstances or whether there are some limitations of this approach. For this purpose I conducted a study based on simulated datasets. Algorithm used enabled generation of datasets that differed in several parameters of interest but which were most comparable in other aspects. Results show that hierarchical models represent choice leading to highest accuracy in predicting respondents' choices in holdout tasks. Use of hierarchical models is most beneficial in the situation of strongly heterogeneous population yet limited amount of available data. In these cases we are able to capture the structure of heterogeneity with significantly lower number of choice task necessary from each respondent. Second goal of the dissertation was to answer the question whether we can increase also the effectiveness of the questioning in conjoint analysis by adding several direct questions. Suggested hybrid choice-based conjoint method (HCBC) combines conjoint analysis tasks with direct questions regarding the preference of levels for each attribute. These are used during the estimation of the model and for increasing the effectiveness if the conjoint analysis tasks design. The HCBC was compared with traditional choice-based conjoint (CBC) and adaptive choice-based conjoint (ACBC) based on practical study involving 421 respondents randomly assigned in one of three test groups. Suggested method has been found as useful alternative that can help with reducing number of choice task needed and as a solution for some situations when diverse importance of the attributes tested does not allow for indirect estimation of preferences with respect to all attributes tested.

The problematics of weldability of heterogeneous welds of aluminium and titanium alloys produced by electron beam welding is discussed in this work. Homogenous welds of selected alloys were analyzed in the first stage. Welding of these materials relates to formation of intermetallic phases at the interface of base materials due to differences in physical, chemical and metallurgical properties of base materials. One of the prerequisites for producing high quality weld joints is to find optimal process parameters. The influence of selected process parameters to integrity, structure and mechanical properties of heterogeneous Al/Ti joints is evaluated.

This thesis is focused on assessment of fracture behaviour of heterogeneous welded joint. The goal is to determine fracture behaviour at the interface of ferritic base metal and austenitic weld metal at temperature of 255°C. This kind of weld is widely used at energy industry. Fracture toughness was evaluated using CT specimens with size 0,5T in order to determine the initiation values of stable crack propagation. Fracture behaviour of the weld is correlated with results of metallography and fractography analysis. Both light and scanning electron microscopy is used for fractography analysis. An assessment of fracture behaviour of the interface of the weld joint is first of all connected with a need of suitable location of cycled crack to the interface of metals. In the case of well-prepared crack the lowest values of J-integral are observed. In other cases of slight crack deviation from the notch plane fracture values increase. Due to a large scatter of mechanical properties of heterogeneous weld joints an increased number of test specimens is needed to obtain relevant and conservative fracture toughness values. Correlation of fracture toughness with the results of fractography analysis leads to clarification of the crack trajectory and to description of fracture mechanism.

This Master´s thesis deals with heterogeneous photochlorination of polyolefins and especially with the photochlorination of polypropylene itself. In the theoretical part the available information about properties, manufactory and application of chlorinated polyolefins, specifically polyethylene and polypropylene, is provided. The basic principles of the photochemistry are described, which are further applied to the issue of photochemistry chain reactions and photochemical halogenations, mainly photochlorinations. The practical part includes design and realization of few types of equipment for the heterogeneous photochlorination of polypropylene done at low temperatures (to 50° C) by gaseous chlorine in bulk or chlorine suspended in suspension of PP in CCl4. Series of chlorination was accomplished, which was varied in the type of PP, in the way of dosage Cl2 and in the period of high pressure mercury lamp irradiation (1–90 minutes). The chlorine content in prepared samples was determined by the gravimetry with ATR-FTIR spectroscopy, as well as by the Shöniger combustion method. Their accuracies were than compared. The chlorine content dependence on the period of chlorination and on the porosity of initial PP was established.

The first part of the thesis discuss general characterization of heterogeneous processes in silicates. This part is focused on kinetics of heterogeneous processes and mathematical description of reactions time behavior. The other part describes important technologies in silicate industry such as sintering, solid matter decomposition, transition modification, etc. Another chapter deals mineralogy, structure and properties of eminent silicate raw materials. Emphases is given to characterization of clay minerals and their utilising. The experimental part handle the analytic techniques used for investigation of thermal decompostion, dehydroxylation, crystalization of Al-Si spinel phase and sintering process of washed kaolin Sedlec Ia from the region Carlsbad (Czech Republic). Concluding chapter reports on results of experimental work.

Disertační práce se zabývá kryptografickými protokoly poskytující ochranu soukromí, které jsou určeny pro zabezpečení komunikačních a informačních systémů tvořících heterogenní sítě. Práce se zaměřuje především na možnosti využití nekonvenčních kryptografických prostředků, které poskytují rozšířené bezpečnostní požadavky, jako je například ochrana soukromí uživatelů komunikačního systému. V práci je stanovena výpočetní náročnost kryptografických a matematických primitiv na různých zařízeních, které se podílí na zabezpečení heterogenní sítě. Hlavní cíle práce se zaměřují na návrh pokročilých kryptografických protokolů poskytujících ochranu soukromí. V práci jsou navrženy celkově tři protokoly, které využívají skupinových podpisů založených na bilineárním párování pro zajištění ochrany soukromí uživatelů. Tyto navržené protokoly zajišťují ochranu soukromí a nepopiratelnost po celou dobu datové komunikace spolu s autentizací a integritou přenášených zpráv. Pro navýšení výkonnosti navržených protokolů je využito optimalizačních technik, např. dávkového ověřování, tak aby protokoly byly praktické i pro heterogenní sítě.

At present, the issue of occurrence of female sex hormones, estrogens and progestogens, in aquatic ecosystems is often discussed by experts and the general public. These substances of steroid structure can be difficult to remove completely by conventional wastewater and drinking water treatment technologies. In given context advanced oxidation processes based on in situ generation of highly reactive hydroxyl radicals can be a suitable technique. This thesis deals with the study of kinetics and degradation products of photocatalytic decomposition of seven female sex hormones (estrone, -estradiol, estriol, ethinylestradiol, diethylstilbestrol, progesterone and norethindrone). Experiments were conducted in a laboratory glass reactor, which was equipped with an energy efficient UV-A LED light source (365 nm emission wavelength) and an immobilised photocatalyst in a form of TiO2 five-layer film deposited on glass. Model samples of water with the initial hormone concentration of 1 mg·L-1 were used and the degradation process was monitored by an HPLC-MS method. In the given system all compounds of interest except estriol had very significant tendency to be adsorb. In the case of estriol the formal rate constant of photocatalytic decomposition was determined based on the Langmuir-Hinshelwood model for two different initial concentrations, 0.5527 hour-1 (1 mg·L-1) and 0.1929 hour-1 (5 mg·L-1), and by comparison of these values it was found that the higher degraded compound concentration, the slower decomposition (fivefold increase of the initial concentration resulted in the constant decrease to almost one-third). Moreover nine degradation products of estriol photocatalytic decomposition were recorded and their structure was designed based on mass spectra. In the second thematic part of the thesis attention was paid to development of a SPE-HPLC-MS method for simultaneous determination of female sex hormones in water ecosystems, with emphasis on an extraction part optimization. The final samples treatment process included besides extraction with Supel™ Select HLB 200 mg SPE cartridges also mechanical impurities removal, hormones extraction from solids trapped on filtration material, sample acidification and extract purification with Supelclean™ ENVI-Florisil® cartridges. Optimised method was used for determination of female sex hormones in two Brno rivers, Svitava and Svratka. In the most cases the concentration was below the detection or quantification limit.

This dissertation thesis deals with determination of the mechanical properties of weld materials based on instrumented hardness test. This work was caused by the research project between IAM Brno Ltd and CEZ corp., when the task was to develop a methodology for evaluation of mechanical material properties using NDT methods. For these reasons the development of methodology is reflected especially for use in practice focusing to determining the mechanical properties of the heterogeneous weld joint on the assembled equipment. The mechanical material properties are determined by carrying out non-destructive tests of the instrumented Vickers hardness. The developed methodology for determining of basic mechanical properties is based on the principle of inverse FEM modeling of the instrumented hardness tests, when output of the testing is indentation curve and measured surface imprint after unloading. The basic material mechanical properties are achieved by comparing the outputs of the experimental instrumented hardness tests and the outputs of the modeled hardness test using FEM.

We investigate a nonlinear reaction-diffusion system coupled with convection- diffusion system. This combined system corresponds to physical description of heteroge- neous catalysis when the flow of bulk-constituents is driven by a given stationary velocity field; diverse mechanisms between bulk- and surface-parts of the model-domain are de- scribed by Langmuir-Hinshelwood absorption kinetics; and the irreversible reactions on the catalytic walls meets the law of mass action with quadratic rate. The first part of the thesis is focused on analytical results; in Chapter 2 we prove existence and unique- ness of a mild solution for so-called near-by problem using nonlinear semigroup theory; in Chapter 3 we investigate the weak formulation of the problem. We prove an existence of a weak solution for little modified problem which, under an assumption, coincides with the original problem. In the second part of the thesis (Chapter 4) we numerically investigate the evolution of the bio-diesel microreactor. We compute numerical solutions using several methods and we test the results by analytical and physical conditions; with the aim to find the most efficient way to compute precise and physically correct solution. Keywords: heterogeneous catalysis, coupled reaction-diffusion/convection-diffusion system, nonlinear...

Title: Role of surface defects in ceria-based catalysis Author: Andrii Tovt Department: Department of Surface and Plasma Science Supervisor of the doctoral thesis: doc. Mgr. Josef Mysliveček Ph.D., Department of Surface and Plasma Science Abstract: This work concentrates on the analysis of fundamental physicochemical properties of Pt-CeOx, single-atom Pt1 /CeOx, and inverse CeOx/Cu(111) catalysts. Preparation method for stabilized atomically-dispersed Pt2+ ions on ceria was developed and adsorption sites for Pt ions were thoroughly studied using advanced surface science techniques supported by theoretical methods. The mechanism of Pt2+ stabilization on ceria steps was revealed and the step capacity towards Pt2+ ions was estimated. Also, the preparation method for well-ordered cerium oxide ultrathin films with different stoichiometry and ordering of surface oxygen vacancies was developed, and the Ceria/Cu(111) interaction was investigated. Key words: heterogeneous catalysis, model systems, single-atom catalysis, platinum ions, cerium oxide.