Spelling suggestions: "subject:"keramik""
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Zdice - výsledky záchranného archeologického výzkumu knovízské kultury / Zdice - results of the excavation of a Knovíz culture settlementŠITNER, Marek January 2015 (has links)
The thesis presents results of the excavation of an early bronze aged settlement on the cadaster of Zdice in Beroun region. The detailed analysis of its pottery complex provides a base for chronological determination of the settlement and defines its components. Special attention is also paid to the issue of settlement burials of Urnfield culture.
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Životní styl měšťanů ve středověkých Českých Budějovicích. Analýza archeologického materiálu z Hroznové ulice, domu čp. 23 / The lifestyle of burghers in the medieval town of České Budějovice. An analysis of archaeological material from Hroznová Street, house no. 23KOCINA, Jan January 2016 (has links)
The aim of the work is to broaden the knowledge of historical bourgeois material culture in the centre of České Budějovice. The analysis focuses on pottery wares and other material obtained during the rescue archaeological excavation on the plot of house no. 23. The morphological as well as technological characteristics of the assemblage under study are observed and provide a better understanding of the evolution and transformation of the material culture of the medieval city.
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Interpretace přírodní formy jako výtvarného artefaktu / Interpretation of a Natural form as a Pictorial ArtefactMONDLOVÁ, Erika January 2015 (has links)
The thesis deals with the historical development of applied arts and the plant motifs of decorative creation. There is also mentioned the problem of the natural geometric decorative motifs development and the difference between the functional and decorative artefact. Then there are described the sources of inspiration, which were used as basis for the practical part. Description of the practical part deals with the production of ceramic artefacts, then with the problem of colours and in the end it describes the installation of light into one of the objects, which is the decorative light.
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Keramika na 1. stupni ZŠ / Ceramics for the First Grade of Primary SchoolFRAŇKOVÁ, Magdalena January 2016 (has links)
At the beginning of the theoretical part the objects and tasks of the theses are defined. There are also described the teaching methods of project teaching at the primary schools. History of ceramics from all over the world from the Neolithic period is an integral part of the theoretical part. The forming techniques, modeling, glazing and burning techniques are described as well. In the practical part ten ceramics themes to the project teaching at the first grade of primary school are designed. There is a didactic documentation for teachers for each theme.
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Kouzlo psaného slova / Magic of writing wordDVOŘÁKOVÁ, Iveta January 2012 (has links)
Thesis magic of the written word is concerned with the changing letters in historical context. It is divided into two parts. The theoretical part informs about the development and use of fonts, writing techniques and cultural influences. It also describes the types described that most influenced the view of the future font. The practical part shows a set of twelve ceramic wall reliefs. Individual reliefs represent the most significant architect in writing and given time stage. The layout concept is based on the perception of the general public.
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"Střípky safari"- mozaikové obrazy, diptych / "Crocks of Safari"-mosaic images, a diptychDOULÍKOVÁ, Radka January 2010 (has links)
My graduation thesis is called {\clq}qCrocks of Safari`` and it is divided into two main segments. The First part is theoretical which explains my inspiration, choice of theme and material, method of working - starting with design, ending with final artwork and its installation. It also considers the techniques of mosaic creation. It includes image documentation, which enriches and completes the text. The Second part is practical which includes its own graphic creation. That is two mosaic images made out of combined material {--} ceramics and glass (mirror) inserted into a metal frame. It features graphic structures and elements of an African fauna. It specifically interprets cut outs from herd of zebras and their typical stripes. My goal was to create abstract images where you can feel the character of used material and harmony of natural structures.
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Studie syntéz a přípravy bezolovnaté keramiky (Ba,Ca)(Ti,Zr)O3 v závislosti na struktuře a výsledných vlastností / Study of the synthesis and processing conditions on the structure and properties of (Ba,Ca)(Ti,Zr)O3 lead-free ceramicsBijalwan, Vijay January 2018 (has links)
V poslední době je snahou nahradit klasickou komerční olovnatou piezoelektrickou keramiku bezolovnatou, z důvodu zvýšeného zájmu o ochranu životního prostředí a zdraví. Různé typy materiálů již byly navrženy, jako například (K, Na) NbO3 (KNN), (Bi, Na) TiO3 (BNT), (Bi, Na) TiO3 – BaTiO3 (BNT-BT), ale jejich piezoelektrické vlastnosti zatím nedosáhly takových hodnot jako u olovnatý chkeramik (např. olovnatý titanát olova ((Pb Zr)TiO3). Nejvíce se olovnatým materiálů blíží bezolovnatý systém na bázi (1-x)Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 nebo (Ba, Ca) (Zr, Ti) O3 ((1-x)BZT-xBCT, BCZT) a to díky vysokým piezoelektrickým a dielektrickým parametrům. Nevýhodou tohoto prostředku je jeho velmi vysoká teplota slinování (1520 ° C) za účelem dosažení vysokých piezoelektrických vlastností (např. Piezoelektrické konstanty d33 > 600 pC / N). Tato práce se zabývá bezolovnatou keramikou na bázi BCZT, její výrobou a vylepšením piezoelektrických vlastností dopováním CeO2. Přidáním CeO2 (y wt.%) do (Ba0.85Ca0.15) (Zr0.1Ti0.9) O3 se výrazně snížila slinovací teplota a došlo ke zhutnění při 1350°C. U této kompozice se Curieova teplota pohybovala kolem TC~105°C a velikost zrn byla v rozmezí ~ 10-13 m. Fázový přechod z romboedrické struktury na tetragonální (R-T) byl zjištěn pomocí rentgenové spektroskopie u y = 0 - 0.1 wt.%, což koreluje s výsledky Ramanovy spektrální analýzy. Mikrostrukturní a strukturní charakteristiky byly detailně studovány v korelaci s dielektrickými, feroelektrickými a piezoelektrickými vlastnostmi. Nejlepší funkční vlastnosti byly dosaženy pro keramiku BCZT – 0.07 wt.% CeO2. Tato keramika vykazovala piezoelektrický nábojový koeficient d33 = 507±20pC/N, elektromechanický planární koeficient kp = 51.8 %, dielektrickou konstantu r = 4091±100, ztrátový činitel tan = 0.02, remanentní polarizaci Pr = 13.58C/cm2, intenzitu koercitivního pole EC = 2.13kV/cm při normovaném napětí, d33* nebo Smax/Emax = 840pm/V. Dvoustupňovou kalcinační technikou bylo docíleno homogenního růstu zrn s vysokou relativní hustotou (~ 99% teoretické hustoty). Tato kompozice BCZT- CeO2 vykazovala stálé feroelektrické, dielektrické a piezoelektrické vlastností i při velikosti zrn 10 µm. Bezolovnatá piezoelektrická keramika (Ba0.85Ca0.15-y Cey) (Zr0.1Ti0.9) O3 (BCCeZT) byla dále dopována CeO2 s cílem substituce Ce4+ v místě A krystalické mřížky. Posunutí rentgenových vrcholů k vyšším úhlům naznačuje kontrakce mřížky, což by mohlo způsobit obsazení iontů ceru v místech A této soustavy. Bylo zjištěno, že velikost zrn kolem 10 - 12 m je významná pro vysokou piezoaktivitu bezolovnaté BCCeZT keramiky. Nejvyšší piezoelektrické vlastnosti tato keramika vykazovala při y;Ce = 0.00135 a slinovaná na teplotě 1350°C/4h, kdy piezoelektrické parametry byly d33 = 501±10 pC/N, kp = 38.5±1.92 %, Pr = 12.19 C/cm2, TC = 108.1 °C a s maximální deformací S do 0.14 %. Pro další studium substituce v místě A, byly vyrobeny keramické materiály (Ba1-x-y Cax Cey) (Zr0.1 Ti0.9) O3 (x:Ca = 0.05, 0.10, 0.15, 0.20 a y;Ce = 0.00135). Opět se ukázalo, že pokud byla velikost zrn ~13um, tak keramika vykazovala vysoké piezoelektrické vlastnosti (d33 = 457pC/N) pro x = 0.15 % kalcinované na teplotě 1425 °C. Když se se velikost zrn zvýšila nad 16 um, piezoelektrický nábojový koeficient d33 klesl na 200 pC/N. Rentgenová analýza ukázala změnu fázové struktury z rombické na tetragonální při zvýšení obsahu vápníku.
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Efektivní obrábění nových keramických materiálů / On the Effective Machining of New Ceramic MaterialsSámelová, Vendula January 2019 (has links)
Advanced ceramics have long held the front of the list of promising materials for high-tech applications. The most common problem is the high cost of design, production and machining of advanced ceramics parts. The main sense of advanced ceramics processing techniques development is affordable, high-volume production. The dissertation is focused on SiC silicon carbide grinding. SiC is used in the design of machine parts due to its excellent properties The deep knowledge of the diamond wheel grinding process is important because it is one of the finishing methods and therefore has a direct impact on the quality and strength of the SiC parts. The key issue here is the overall surface quality of the parts after diamond wheel grinding and the knowledge of the factors that influence the surface quality. These include, in particular, grinding vibrations. The main purpose of the thesis is to create a system of specific scientific and technical information, which will allow applying optimal technological procedures in the processing of ceramic components. The theoretical part of the thesis contains an analysis of the current state of the art in the advanced ceramics machining area, detailed analysis of the ceramics grinding with diamond grinding wheels, signal analysis theory and analysis of surface quality assessment methods. The experimental part contains analysis and discussion of the results obtained during the monitoring of the silicon carbide grinding process with a diamond grinding wheel. Various diagnostic methods have confirmed the presence of vibrations at a frequency close to the speed frequency of the grinding wheel, which had a significant, negative effect on the samples surface quality. Vibration diagnostics has identified a specific source of vibration (clamping of the workpiece) and it has been removed subsequently.
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Žárovzdorné materiály na bázi oxidu hlinitého pro bezcementové aplikace / Alumina based refractories for noncement applicationBöhm, Petr January 2020 (has links)
The thesis deals with the possibility of bonding the ceramic mixture by a sol-gel method, Colloidal alumina was used as the sol and the gelation was performed by changing the ionic strength or pH. The influence of different gelling agents (NaCl, NH4Cl, NH3, MgO a CO(NH)) on the gellation time and on the course of the gelation was compared. The aim of the work is the preparation of refractory monolith with the highest packing desity possible, which was solved by modeling the granulometric curve of the solid part of the ceramic mixture based on alumina. The thesis also describes the behavior of prepared gels during thermal processing of ceramics. Subsequently the resulting structure of prepared ceramic bodies was monitored.
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Využití slídového separátu z plavení kaolinu / Utilization of mica separated from washed kaolinVaculík, Josef January 2020 (has links)
The Master’s Thesis aims to laboratory test the possibilities of utilization mica separate, which arises during the process of floating kaolin as a by-product together with sand. Mica and sand are then separated by flotation or vibration. The mica separate thus formed was subjected to analysis. XRD and heating microscopy methods were used for analysis. Subsequently, experiments with mica separation as a filler in composites based on epoxy resins were set up and performed. Furthermore, the separate was tested as a part of plasters and visual building elements. Last but not least, the separate was mixed into the ceramic, which was then subjected to firing in the selected mode. The diploma thesis provides a comprehensive overview of the above-mentioned possibilities of using mica separation, which is based on a sufficient amount of experimental data.
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