Machining of Ceramic

Import 31/08/2009PAVLŮ, O. Obrábění keramiky. Ostrava: Katedra obrábění a montáže, Fakulta strojní, VŠB – Technická univerzita Ostrava, 2009, Bakalářská práce, vedoucí Doc. Ing. Vladimír Vrba, CSc. Bakalářská práce se zabývá vlivem parametrů obrábění na vznik trhlin v keramickém materiálu pro firmu CeramTec Czech Republic s.r.o. V úvodu je obecně zmíněna charakteristika daného problému. V další části jsou pak popsány vlastnosti materiálů. Dále pak obrábění, které je hlavní náplní bakalářské práce. V praktické části jsou popsány měření a výsledný vliv nastavení na vznik trhlin. Závěr patří zhodnocení této práce.PAVLŮ, O. Machining of Ceramic. Faculty of Mechanical Engineering VŠB – Technical University Ostrava, 2009, Bachelor Thesis, head: Doc. Ing. Vladimír Vrba, CSc. The bachelor theses deals with an influence of shaping parameters on crazing in ceramics for CeramTec Czech Republic s.r.o. The introduction of this bachelor theses includes the common characterization the query. In the other part are given an account of material properties. The next is tooling which is the main subject of this bachelor theses. In the practically part are described measurements and resulting influence of petting on crazing. The conclusion includes evaluation of this bachelor theses.345 - Katedra mechanické technologiedobř

REMEDIATION TECHNOLOGY OF CLOCHE REPLACEMENT FOR WW2 FORTIFICATION IN THE CZECH REPUBLIC

Nowadays many parts of the Czechoslovak border fortification built in 1935 – 1938 have been sold to the private owners who want to reconstruct it. One of the biggest problems while reconstructing these objects is missing cloches. The aim of this study is to find solution of this problem. Authors wanted to offer the owners (usually clubs of military history) authentic design of the cloche for low cost, high durability and full functionality of the cloche that enables installation of original weapons.A result of the work was a development of a technical solution of the cloche consisting of a replica of the upper part made of reinforced concrete in combination with lower part made of concrete. This unique technical solution was confirmed as an utility model CZ32920(U1). Remediation measure was approved by the team at the pillbox T-S 20 in Červený Kostelec in 2019

Negative political campaign on example of the Czech parliamentary election 2010

The diploma thesis "Negative political campaign on example of the Czech parliamentary election 2010" describes the concept of negative political campaign in both historical and theoretical context and afterwards it presents the concept in the Czech milieu on the example of Czech parliamentary election 2010. On the basis of primary literature is negative campaign defined and after that early examples in the United States of America and in Great Britain are described. Described are also reasons for its using, tactical functions, used techniques, the risks consequent upon its using as well as the academic studies, which are examining it. In the second part the context of development of negative campaign as well as the history of its using in Czech Republic are described and after that is negative campaign presented in details within the concrete case study of Czech parliamentary election 2010

Project Study of the Production Process Application Colourless Nanocoating on Pipes

Import 04/07/2011PAVLŮ, O. Projektová studie výrobního procesu aplikace transparentního nanopovlaku na roury, Ktedra mechanické technologie, Fakulta strojní VŠB – Technická univerzita Ostrava 2011. Diplomová práce, vedoucí: Podjuklová, J. V teoretické části mé diplomové práce se zabývám problémem aplikací nátěru na povrch. Jsou zde zmíněny vhodné předúpravy základního materiálu, tak i jeho vlastnosti. Dále v této části práce popisuji vhodnou aplikaci nátěrových hmot, tak i jimi samotnými. Experimentální část je zaměřena na kvalitu adheze mezi válcovanými trubami a nanopovlakem na bázi fosforečnanu zinečnatého. Je zde proveden rozbor základního materiálu, ale i rozbor povlaku. Samotné vzorky jsou podrobeny mřížkové a křížové zkoušce a jejich výsledky porovnány a vyhodnoceny. Na základě těchto výsledků je v projektové studii navržena lakovna trub. Uvádím v ní všechny zařízení z celého procesu, popisuji technologii lakování a časy, kterými je linka charakterizovaná.PAVLŮ, O. Project Study of the Production Process Application Colourless Nanocoating on Pipes, Department ofMechanical Technology VŠB – Technical University of Ostrava 2011. Thesis head: Podjuklová, J. In the theoretical part of my thesis deals with problems of application of paint to the surface. Are there suitable pre-mentioned basic material and its properties. Also in this section, I describe the appropriate application of paints, as well as by themselves. The experimental part is focused on the quality of adhesion between the rolled and trumpets Nanocoatings based on zinc phosphate. There is an analysis of the basic material, but also an analysis of the coating. The actual samples are subjected to lattice and cross-examination and the results compared and evaluated. Based on these results, the proposed project design paint shop ovens. I give her all the facilities of the whole process, describe the technology of paint and time, which is characterized by line.345 - Katedra mechanické technologiedobř

Soil organic matter quality of variously managed agricultural soil in the Czech Republic evaluated using DRIFT spectroscopy

This study focuses on the effect of agricultural soil management on soil organic matter (SOM) composition. The addition of manure and crop residues was tested under different pedoclimatic conditions. The quality of SOM was assessed using diffuse reflectance infrared spectroscopy. The following parameters were calculated from the spectra:   sum of aliphatic bands (ΣAL), aromatic bands at wave numbers 1 620 and 1 520 cm-1 (AR1620 and AR1520), potential wettability (PWI), organic matter quality (OMQ), and decomposability (DI) indexes. The addition of manure or crop residues may not cause fundamental changes in the qualitative composition of SOM. Rather, pedoclimatic conditions determine which components are fixed in the soil on a long-term scale. A dominant effect of soil type was found in the distribution of all spectral parameters studied using main effect ANOVA. The main differences between the soil types concern the aromatic, oxygen and nitrogen groups contained in the SOM. Chernozems are soils with higher OMQ and DI, whereas Cambisols are soils with low OMQ and DI and the highest PWI. The stabilisation of SOM in soils can thus be based on the biochemical persistence of organic molecules, their specific affinity for minerals and the formation of aggregates that protect enclosed SOM

Effects of slope and tree position on soil properties in a temperate deciduous forest

This paper examines changes in soil physical and chemical properties in relation to tree proximity on different slopes. Topsoil and subsoil were sampled at 12 research plots on four slope types, the soil pits being placed at the base of a tree (near tree, NT) and between the test tree and an adjacent tree (between trees, BT). We observed a significant decrease in vertical topsoil response to slope on lower, middle and upper slopes, and a decrease in fine roots (R < 2 mm) on flat ground. Overall, middle and lower slopes showed the highest similarity, and upper slopes and flat ground the least, with the greatest subsoil changes observed mainly on middle slopes and least on lower slopes. There was clear topographic dependence between subsoil water stable aggregates (WSA) and C dynamics, with BT total carbon (Ctot) higher on flat ground and lower on middle slopes; unlike topsoil, where the strongest WSA correlation was with distance from the tree. The highest N : OM (organic matter) ratios occurred on middle slopes facing north-west, and lowest on lower slopes facing north and flat ground. Our findings confirm the influence of slope type on soil characteristics, with NT soil supporting soil formation by transporting water to deeper layers, especially on slopes > 5°. These observations contribute to a better understanding of the dependence of soil properties on slope type and tree position when planning sustainable forest management

Fluorescent magnetic nanoparticles for cell labeling: Flux synthesis of manganite particles and novel functionalization of silica shell

International audienceNovel synthetic approaches for the development of multimodal imaging agents with high chemical stability are demonstrated. The magnetic cores are based on La0.63Sr0.37MnO3 manganite prepared as individual grains using a flux method followed by additional thermal treatment in a protective silica shell allowing to enhance their magnetic properties. The cores are then isolated and covered de novo with a hybrid silica layer formed through the hydrolysis and polycondensation of tetraethoxysilane and a fluorescent silane synthesized from rhodamine, piperazine spacer, and 3-iodopropyltrimethoxysilane. The aminoalkyltrialkoxysilanes are strictly avoided and the resulting particles are hydrolytically stable and do not release dye. The high colloidal stability of the material and the long durability of the fluorescence are reinforced by an additional silica layer on the surface of the particles. Structural and magnetic studies of the products using XRD, TEM, and SQUID magnetometry confirm the importance of the thermal treatment and demonstrate that no mechanical treatment is required for the flux-synthesized manganite. Detailed cell viability tests show negligible or very low toxicity at concentrations at which excellent labeling is achieved. Predominant localization of nanoparticles in lysosomes is confirmed by immunofluorescence staining. Relaxometric and biological studies suggest that the functionalized nanoparticles are suitable for imaging applications