Forms of cavernous weathering - tafoni and honeycombs - belong to long-term investigated and discussed phenomena in geology. The reason for the difference in size between few centimetres- long honeycombs and the several-metres-long tafoni has not been yet studied. In my master thesis I compared the hydraulic properties of rocks with developed honeycombs and tafoni. The research consists of field measurements (measurement of suction pressures and capillary water absorption using Karsten tube) and laboratory measurements on tafoni and honeycomb samples (retention curve measurement, capillary water absorption, water vapour diffusion rate and saturated hydraulic conductivity). I have been studing honeycombs from various sites in the Bohemian Cretaceous Basin and tafoni from three different sites: Carbon Arkoses near Kralupy nad Vltavou, Cambrian Sandstone in Petra (Jordan) and Tunnel Spring Tuff in Crystal Peak (Utah). The measurements showed that values of suction pressure are far higher inside tafoni than inside honeycombs. This observation corresponds to different retention curves of studied rocks: steeper retention curve for honeycomb's quartz sandstone than for fine-grained arkosic sandstones to arkoses with tafoni. In the other part of my research I have compared the properties of hydrophobic...

This work is focused on Density Functional Theory (DFT) calculations of oxygen vacancy diffusion barriers in mixed perovskite lead zirconate titanate and its pure counterparts. We found out that barrier heights are different in lead titanate and lead zirconate caused by the different localization of the excess electrons due to the oxygen vacancy formation. Diffusion barriers were also determined for titanium-rich mixed phases and compared to experimental values. This work contributes to clarify unusually low experimentally measured diffusion coefficients in PZT. We found out that the induced vacancy states are forming localized bonds to the lead atoms which causes the oxygen vacancies to become immobile due to the increase of the activation energy of the diffusion process.

Diploma thesis is about image sensor security. Goal of the thesis was study data integrity gained from the image sensors. Proposed method is about source camera identification from noise characteristics in image sensors. Research was about influence of denoising algorithms applied to digital images, which was acquired from 15 different image sensors. Finally the statistical evaluation had been done from computed results.

This master's thesis deals with a present problem of alternative dental fillings, which should replace amalgam fillings. Although there are health concerns about these alternative materials, especially resin composite fillings raise concerns, because they release potentionally harmful substances into the oral cavity. Accordingly even this medical device subjects various tests before releasing to the commercial market and one of these tests was carried out according to ČSN EN ISO 10993 and available scientific literature in the experimental part of this thesis. The amalgam controversy, substances used for manufacturing of resin dental fillings and analytical methods are described in the theoretical part of the thesis. In the experimental part of the thesis, 30 days long cumulative extraction experiments were carried out into various extraction mediums in order to assess suitability of new dental resin filling from ADM, a.s. by comparison with commercially available dental material from company GC EUROPE N.V. These samples were analysed by LC-MS and the amount of eluted substances from dental composites to extraction medium was quantified.

This master thesis focuses on dMRI (diffusion magnetic resonance imaging) and its dependance on diffusion in human brain tissue. It is described how to retrieve an image from gained data and its properties, advantages and disadvantages. It mentions problem in detecting kissing fibres due to its similarity with crossing fibres. Design of mathematical models of axons is decribed and suggested measurement to detect difference in signals for kissing and crossing fibres. It describes new simulator of diffusion-weighted MRI (dMRI) data which is able to generate it based on random walk algorithm with geometrical constraints not only for crossing fiber geometry, but also as o novelty for bending and kissing fiber geometries. This study contains results of simulations and disscusion about their usefulness with suggestions for simulator improvement. Simulated dMRI data shows significant difference in certain gradients. Data reconstruction shows, that these reults cannot be reconstructed into the same geometry as it was simulated for.

In thesis is dealt with problematic of how the value of air permeability may be affected by properties for water vapour diffusion with regard to OSB material There were chosen two main brands of OSB at Czech trade market Two specimens of OSB with different thickness were chosen for each brand. As a first the specimens were tested for air tightness to work out a value of air permeability for each specimen. Afterwords, the testing was conducted for gaining properties of water vapour diffusion on each specimen. As a final assessment was analysed the impact of properties of water vapour diffusion on the air tightness for each specimen. The general meaning of gaining higher air tightness with higher water vapour resistance was proved . It was shown that with raising thickness is usually gotten higher value of water vapour diffusion resistance. However it could not mean getting high air tightness. The crucial parameter is the quality of the material for gaining higher resistance against water vapour diffusion as well as for higher airtightness.

The aim of this work was to establish a comprehensive processing pipeline of cervical spinal cord HARDI dMRI data and T2-weighted anatomical MRI images in high-resolution. In the research part we provide description of anatomical data processing, theoretical background of dMRI, description of current approaches to 3D anisotropic diffusion estimation as well as current imaging methods of spinal cord axonal bundles. As one of the first in the world, we are investigating multiple-direction diffusion models for human in-vivo spinal cord white matter minority bundles imaging. We designed our own processing pipeline utilizing Spinal Cord Toolbox (SCT), FSL, in-house developer scripts and TORQUE-based batch system for grid computation, tested on real data from cervical spinal cord area between segments C4-C6 from 26 healthy volunteers. Designed processing pipeline with one non-automatic step, works from pre-processing to parcelation of selected spinal cord structures based on co-registration with anatomical spinal cord template for 25 subjects. One person data includes motion artifacts for which the proces failed. There are visible waves in sagittal images of some subjects caused probably by blood-vessel pulsing. Local quantification metrics of spinal cord anatomy (fractional anisotropy – FA, fractional volumes of first – f1 and second – f2 direction of anisotropic diffusion) from different parts (white matter, gray matter, cortico-spinal tract) and from different population groups (men vs. women), were extracted from dMRI data. As we expected, FA maps show visible decreases in areas of gray matter. We also detected second diffusion dirrection in slices, where the spinal roots come out. In some areas, fractional volume of second diffusion direction reaches up to 40% of the total component of the dMRI signal. All mentioned parameters probability density functions for all mentioned groups are non-normal distributions. Between male and female groups there were no significant distribution differences for f1 and f2 volumes. The distribution of FA values between men and women is statistically different. Unfortunatelly, there is a significant inter-subject variability in results, which has much higher dispersion than differences between different group distributions. Despite the inter-subject variability, this work significantly extends the knowledge about data acquisiton capabilities and MRI and dMRI data from cervical spinal cord image processing. This work also lays down foundations for utilization of the imaging method in future and planned clinical research, where it will be possible to test the alteration of the spinal cord anatomy on the minor secondary bundles separately.

The thesis is focused on consumer behavior in relation to electric vehicles. In the beginning, the issue of alternatively fuelled vehicle is briefly introduced, including the explanation how this product is supported by the European Union. The next part is devoted to the theoretical background applied in the work. After the theoretical part, there is the literature review followed by both, the qualitative and the quantitative investigation. The results obtained were compared with the results stemming from international research projects. In accordance with the Theory of Diffusion of Innovations, the participants of qualitative survey were labelled as innovators or early adopters, for whom technical knowledge is more important. But on the other hand, for later adopters, the interpersonal relationship is more important, as they can compensate the lack of technical knowledge this way. As follows from the results of qualitative survey, decision-making connected with the acquisition of electric vehicles is influenced by the overall awareness (or knowledge, experience), then by technical characteristics of the purchase together with economic factors and by the perceived expectations of other people. Most of participants have some knowledge about electric vehicles. They often mention barriers preventing...

This thesis is concerned with analysis and implementation of Time discontinuous Galerkin method. Important part of it is constructing of algorithm for solving nonlinear convection-diffusion equations, which combines Discontinuous Galerkin method in space (DGFEM) with Time discontinuous Galerkin method (TDG). Nonlinearity of the problem is overcome by damped Newton-like method. This approach provides easy adaptivity manipulation as well as high order approximation with respect to both space and time variables. The second part of the thesis is focused on Time discontinuous Galerkin method, applied to ordinary differential equations. It is shown that the solution of Time discontinuous Galerkin equals the solution obtained by Radau IIA implicit Runge-Kutta method in the roots of right Radau Quadrature. By virtue of this relation, error estimates of the order higher by one than the standard order can be obtained in these points. Furthermore, almost two times higher order can be achieved in the endpoints of the intervals of time discretization. Finally, the thesis deals with the phenomenon of stiffness, which may dramatically decrease the order of the applied method. The theoretical results are verified by numerical experiments. Powered by TCPDF (www.tcpdf.org)

The presented thesis deals with the utilization of TOF-LEIS analytical method in the area of nanostructure analysis. A new procedure for depth profiling of the elemental composition of the sample, based on the alternate measurement with the DSIMS method, was established. The TOF-LEIS method is able to detect the interface between the layers before its mixing by the ion beam of the DSIMS method. Furthermore, a procedure of TOF-LEIS spektra modification was established to obtain the actual concentration of elements in the sample by reduction of a multiple collision contribution. By comparison of TOF-LEIS spectra with the results received by the DSIMS method the ratio of molybdenum and silicon ion yields was obtained. In the next section advantages of the TOF-LEIS method in combination with XPS during analysis of thermal stability of gold nanoparticles are presented. The mutual complementarity of both methods is shown and final conclusions are supported by electron microscopy images. The final section deals with a newly assembled apparatus for the TOF-SARS analytical method and shows its possibilities regarding the detection of hydrogen on the graphene.