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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
371

A poética do pote / A poética do pote

Lorena D\'Arc Menezes de Oliveira 27 September 2011 (has links)
A dissertação apresentada compreende reflexões em torno do pote cerâmico relacionado à prática artística, tanto em meu processo de criação como na produção artística contemporânea. O pote no qual trabalho a minha poética parte da forma clássica da louçaria utilitária doméstica e é suporte para o desenvolvimento de uma prática em que ele se apresenta fora de sua aplicabilidade funcional ou de seu contexto original. A partir da forma da tigela, desenvolvo trabalhos através de múltiplos, uso recursos de impressões serigráficas e tipográficas e outras interferências, como o tricô, na tentativa de trazer outro olhar para o utensílio cerâmico. / The research presented includes discussions on the ceramic pot related to artistic practice, as in my creative process, as also in contemporary artistic production. The pot from my poetic work starts in the classical form of the domestic utilitarian pottery and its a support for the developing of a practice, where its shows outside of their applicability, function or original context. From the shape of the bowl I develop my work across multiples, I use resources of silk screen prints and others typographical interferences as knitting, trying to bring another look at the ceramic utensil.
372

Verres, vitrocéramique et céramique à base de TeO2 pour l'optique / TeO2-based glasses, glass-ceramics and ceramics for photonics

Dolhen, Morgane 07 December 2018 (has links)
Du fait de leur grande qualité optique, les monocristaux sont largement utilisés dans le domaine de la photonique, pour l’émission laser de puissance, la conversion de fréquence,.... Les monocristaux sont toutefois limités par leur mode fabrication qui est lent et onéreux et par la difficulté d’obtenir des pièces de grandes dimensions. Les verres tellurites sont des candidats de choix en raison de leur réponse non-linéaire élevée, leur mise en forme aisée et leur faible coût de production. Toutefois, pour certaines applications nécessitant des effets non-linéaires de second ordre, les verres ne peuvent pas être utilisés en raison de leur isotropie optique. Au cours de cette thèse, nous avons donc entrepris l’élaboration de composites vitrocéramiques tellurites composés de cristaux non-centrosymétriques capables de générer un signal de seconde harmonique. Les composites sont élaborés par co-frittage SPS d’une poudre de verre et de cristaux. Nous nous sommes également intéressés à la réalisation de céramiques transparentes tellurites pour l’élaboration de cavités lasers de dimensions millimétriques. Les matériaux tellurites sont en effet des candidats intéressants en raison de leurs indices de réfractions linéaires élevées et leurs basses énergies de phonon qui favorisent les transitions radiatives. Les céramiques transparentes ont été obtenues par un procédé innovant de cristallisation complète et congruente du verre qui allie la facilité de mise en forme du verre et les propriétés de la céramique finale. Nous avons également mise en œuvre la réalisation d’une nouvelle céramique transparente tellurate (TeVI) par frittage SPS d’une poudre céramique broyée. Les composés tellurates ont l’avantage de présenter de basses énergies de phonons et des propriétés diélectriques micro-ondes intéressantes. / Owing to thier high optical quality, single-crystals are widely used in photonics, for high power laser, frequency conversion… However, single-crystals are constrained by their manufacturing process which is slow and expensive and because it difficult to obtain large parts. Tellurite glasses are ideal candidate due to their high nonlinear response, the easy glass shaping and their low manufacturing cost. Nonetheless, for some kind of applications requiring second order nonlinear effects, glasses can’t be used because of their optical isotropy. During this thesis, we undertook the elaboration of tellurite glass-ceramics composites consisting of noncentrosymmetric crystals able to generate second harmonic signal. Composites are elaborated by SPS co-sintering of a glass powder and crystals. We are also interested in the elaboration of transparent tellurite ceramics in order to make millimetric laser cavities. Indeed, tellurite-based materials are interesting candidates owing to their high nonlinear refractive index and their low phonon energy, which favors radiative transitions. Transparent ceramics have been fabricated by an innovative way, the full and congruent crystallization of glass which combines the easy glass shaping and the properties of the final ceramic. We have also developed the elaboration of a new transparent tellurate ceramic (TeVI) by SPS sintering of a crushed ceramic powder. Tellurate compounds have the advantage of showing low phonon energy and interesting microwave dielectric properties.
373

Resíduos sólidos industriais do setor cerâmico: uma proposta para redução do impacto ambiental a partir do design e da tecnologia de impressão tridimensional / Industrial solid wastes from the ceramic industry: A proposal to reduce the environmental impact using design and 3D printing technology.

Ambrósio, Marcelo 06 November 2015 (has links)
A indústria de cerâmica branca de objetos decorativos e utilitários, produz diariamente um contingente significativo de resíduo de gesso, oriundo do descarte dos moldes, cuja vida útil é extremamente curta. A deposição desse material via de regra é feita em aterros sanitários, sem qualquer tipo de isolamento em células e sem observar as recomendações da Lei da Política Nacional de Resíduos Sólidos. De acordo com a hierarquia estabelecida pela lei, a supressão da geração dos resíduos sólidos aparece como alternativa prioritária do ponto de vista das boas práticas ambientais. É nessa perspectiva que a tecnologia de produção industrial computadorizada de objetos tridimensionais por deposição de matéria prima, surge como alternativa. A intenção desse trabalho é apresentar conceitos de produtos que potencializem o uso dessa tecnologia através de configurações formais inovadoras para o setor, eliminando a utilização do gesso em seu processo de fabricação além de avaliar os resultados obtidos através da análise dos protótipos fabricados. / White ceramic industry of decorative and utilitarian objects, produces daily a significant contingent of waste gypsum, originated from the disposal of moulds, whose lifespan is extremely short. Deposition of this material usually is made in landfills without any type of isolation cells and without observing the recommendations of the Law of the Brazilian solid waste Policy. According to the ranking established by law, the elimination of solid waste generation appears as a priority alternative in terms of good environmental practices. In this perspective, the technology of computerized industrial production of three-dimensional objects by deposition of raw material, is an alternative. The aim of this paper is to present product concepts that enhance the use of this technology through innovative formal settings for the sector and make an analysis about the results.
374

Effect of processing conditions and second-phase additives on thermoelectric properties of SrTiO3 based ceramics

Srivastava, Deepanshu January 2016 (has links)
Oxide ceramics have been increasingly researched for high temperature thermoelectric (TE) applications. SrTiO3 based materials are promising candidates due to its chemical and thermal stability. In this study, oxide ceramics of composition (1-x)SrTiO3-(x)La1/3NbO3 (0 smaller or equal to x smaller or equal to 0.3) were prepared by single-step solid state sintering in Ar/5%H2 at 1700 K. The density of all the samples prepared was above 90%. All the samples were predominantly single-phase compositions crystallised with a cubic structure in Pm ̅3m space group. The impact of oxygen deficiency, A-site vacancies and mixed oxidation states of Ti3+/Nb4+ on electrical and thermal transport properties was assessed. Optimum TE properties were obtained for x=0.2 (Sr0.8La0.067Ti0.8Nb0.2O(3-delta) = L2), which has 13.4% A-site vacancies. The ZT values improved from 0.2 to 0.27 at 1000 K, with an increase in sintering time from 8 hours to 48 hours, due to increased carrier concentration. Complex interplay of oxygen vacancies and excess donor substitution on A/B-sites of L2 (substituting 5-10% Sr/Ti with La/Nb) exhibited 35% improvement in ZT values, whilst maintaining the A-site vacancies and core-shell structures within grains, which reduced the thermal conductivity by ~50% compared to undoped SrTiO3 samples, due to strong phonon scattering. A facile method to incorporate metallic inclusions (2.5 wt% Fe/Cu) at grain boundaries in L2 ceramics is demonstrated. The modified compositions displayed a maximum ZT of ~0.37 at 1000 K for L2 samples containing metallic inclusions due to increased carrier concentration (5.5 x 10^21 carriers/cm^3) and carrier mobility (2.4 cm^2/(V.s).The addition of graphene/Graphene Oxide (GO) flakes in L2 ceramics has been investigated to improve the electrical conductivity of L2 composites without significantly increasing the thermal conductivity. Spark plasma sintering (SPS) of the composite powders at 1473 K and 50 MPa produced dense samples (>95% relative density) with a homogeneous dispersion of graphene/GO flakes, for loadings smaller or equal to 1.0 wt%. The effect of interaction and distribution of graphene/GO flakes within the ceramics on TE properties is investigated. The composite samples demonstrate anisotropic ZT values, with 20% improvement in the direction normal to the orientation of graphene flakes. A novel sintering method has been proposed which has strong industrial potential. The L2 based composites were sintered in Air at 1700 K (ramp rate: ±300 K/min), whilst samples were covered uniformly. Strong reducing conditions and evolution of secondary phases in the microstructure helped achieve, the very low electrical resistivity of ~3.0 x 10^(-6) ohm.m at room temperature. Secondary phases, sub-micron voids in the grains and A-site vacancies reduced the lattice thermal conductivity (~2.0 W/m.K), comparable to the lowest lattice thermal conductivity achievable (~1.5 W/m.K) at 1000 K and obtain a maximum ZT of 0.4 at 1000 K for L210G-Air/C composites.
375

Inspiration of architecture on contemporary ceramic art.

January 1997 (has links)
Wong Lai Ching. / Slides insert in pocket. / Thesis (M.F.A.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 45-46). / ABSTRACT / INTRODUCTION --- p.1 / Chapter Chapter 1 : --- SYMBIOSIS OF INSIDE AND OUTSIDE --- p.4 / -Transformation of vessel / Chapter Chapter 2 : --- THE CRISIS OF IDENTITY --- p.15 / -The magic of teapot / Chapter Chapter 3 : --- SITE - SPECIFIC WORK --- p.22 / -The giant in nature / Chapter Chapter 4 : --- METABOLISM --- p.35 / -Regeneration and process / CONCLUSION --- p.42 / BIBLIOGRAPHY AND REFERENCE --- p.45
376

Impactos ambientais causados pelas indústrias de cerâmica vermelha no Rio Grande do Sul

Manfredini, Constance January 2003 (has links)
A cadeia produtiva da construção civil está associada a grandes consumos de matérias-primas e energia, além de ser uma das maiores geradoras de resíduo, sendo responsável por parcela significativa dos impactos ambientais a nível global. Embora seja vasta a disponibilidade de literatura internacional a respeito de impactos ambientais causados por materiais de construção, a bibliografia nacional ainda é limitada. Este fato constitui uma barreira na determinação dos impactos ambientais causados por materiais de construção locais, e conseqüentemente os impactos causados pelas edificações e pelo setor da construção. Os materiais cerâmicos estão entre os mais tradicionais empregados na construção civil no Brasil, onde existem aproximadamente 11.000 indústrias, principalmente de pequeno e médio porte. No entanto o setor enfrenta uma série de problemas ambientais, econômicos e de qualidade dos produtos fabricados. Em 2000, o Núcleo Orientado para a Inovação da Edificação (NORIE), pertencente ao Departamento de Engenharia Civil da Universidade Federal do Rio Grande do Sul (UFRGS), iniciou uma pesquisa visando identificar de forma qualitativa e quantitativa os impactos ambientais causados pelo processo produtivo de materiais de cerâmica vermelha, para o Estado do Rio Grande do Sul. Este trabalho analisa os dados coletados em uma pesquisa realizada em 40 indústrias de cerâmica vermelha de diferentes escalas (com produção de 20.000 a 1.500.000 peças/mês) e utiliza a metodologia de Análise do Ciclo de Vida para obter resultados relativos a recursos naturais, fontes energéticas, geração de resíduos sólidos e emissões gasosas, relacionados a cada fase do processo produtivo. Os resultados obtidos revelam os impactos causados pelas indústrias de cerâmica vermelha no Rio Grande do Sul, apontando os aspectos positivos e negativos do processo. São também obtidos dados quantitativos com relação à energia incorporada nos produtos, através de informações coletadas nas indústrias. / The Building Construction supply chain is characterized by a high consumption of raw materials and energy and a high production of waste; being responsible for a significant share in the global environmental impact. Although being large the availability of international literature on environmental impacts determined by building materials, the existing literature on such impacts in Brazil is very limited. This constitutes a barrier to determine the environmental impact of local building materials, and consequently the impact caused by buildings and the building sector. Ceramic products are in the roll of the most traditional construction materials used in Brazil, where there are about 11,000 industries, mostly small and medium sized. However, the sector is going through environmental, economic and product quality problems. In 2000, NORIE, a section of the Department of Civil Engineering Department at UFRGS (Federal University of Rio Grande do Sul), started a research project aiming at identifying quantitative and qualitative environmental impacts caused by ceramic bricks, blocks and tiles production, in the State of Rio Grande do Sul, south of Brazil. This research analyses the collected data on a survey performed at 40 ceramic industries, with different scales (producing from 20,000 to 1,500,000 bricks/month), and uses LCA methodology to obtain results related to material and energy consumption, as well as waste emissions in each process step. The obtained results reveal the environmental impacts caused by ceramic bricks, blocks and tiles industries in Rio Grande do Sul, pointing out positive and negative production aspects. In addition, it was possible to estimate the embodied energy of local ceramic materials through the collected data.
377

Preparation and properties of CCTO ceramics. / Preparation and properties of CCTO ceramics.

January 2007 (has links)
Yuan, Wenxiang = CCTO陶瓷材料的制备和性质研究 / 苑文香. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 63-67). / Text in English; abstracts in English and Chinese. / Yuan, Wenxiang = CCTO tao ci cai liao de zhi bei he xing zhi yan jiu / Yuan Wenxiang. / Acknowledgement --- p.ii / Abstract --- p.iii / Contents --- p.v / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Structure --- p.1 / Chapter 1.3 --- Models --- p.3 / Chapter 1.3.1 --- Parallel RC --- p.3 / Chapter 1.3.2 --- Two parallel RCs in series --- p.5 / Chapter 1.4 --- Motivation --- p.7 / Chapter 1.5 --- Our work --- p.7 / Chapter Chapter 2 --- Experiment --- p.8 / Chapter 2.1 --- Sources and substrate --- p.8 / Chapter 2.2 --- Preparation of the CCTO samples --- p.8 / Chapter Chapter 3 --- Experimental equipment --- p.13 / Chapter 3.1 --- Furnace --- p.13 / Chapter 3.2 --- X-ray diffraction (XRD) --- p.13 / Chapter 3.3 --- Scanning electron microscopy (SEM) --- p.16 / Chapter 3.4 --- Impedance analyzers --- p.17 / Chapter Chapter 4 --- Selections of the experimental conditions --- p.18 / Chapter 4.1 --- Selection of calcining-process conditions --- p.18 / Chapter 4.1.1 --- Experimental results --- p.18 / Chapter 4.1.2 --- Comparison with the results of other research groups --- p.21 / Chapter 4.2 --- Selection of sintering-process conditions --- p.22 / Chapter 4.2.1 --- CuO volatilization --- p.22 / Chapter 4.2.2 --- CCTO decomposition --- p.24 / Chapter 4.3 --- Optimizing of the Cu/Ca ratio --- p.29 / Chapter Chapter 5 --- Results and discussion --- p.31 / Chapter 5.1 --- Properties of CCTO ceramics sintered at different temperatures for 10 h --- p.32 / Chapter 5.2 --- Properties of CCTO ceramics sintered for different durations at 1000°C --- p.43 / Chapter 5.3 --- Properties of CC3+ΧTO ceramics --- p.52 / Chapter 5.4 --- Discussion --- p.58 / Chapter Chapter 6 --- Conclusions --- p.61 / References --- p.63
378

Patologias no sistema de revestimento cerâmico: um estudo de caso em fachadas / Pathologies in ceramic tiling system: a case studies in facades

Pezzato, Leila Maria 04 March 2010 (has links)
A presente pesquisa tem como objetivo realizar uma revisão da literatura sobre as patologias do sistema revestimento cerâmico (SRC) a fim de contribuir com os estudos relacionados à temática. Além disso, buscou-se conhecer e analisar a realidade de um canteiro de obra de recuperação de fachadas com patologias no sistema de revestimento cerâmico e compreender como ocorre o processo de recuperação das mesmas. Este estudo foi dividido em duas etapas: uma revisão da literatura que procurou abranger o sistema revestimento cerâmico e as patologias do sistema revestimento cerâmico e uma pesquisa de campo que optou por realizar um estudo de caso em três edifícios, revestidos com cerâmica, localizados na cidade de Piracicaba, São Paulo. Os estudos de caso evidenciam a produção bibliográfica consultada. Nos três casos analisados ficou evidente a falta de formação dos profissionais envolvidos, faltando-lhes conhecimento aprofundado das patologias recorrentes e do entendimento de que o revestimento cerâmico constitui um sistema. O trabalho se refere a todos os profissionais que fazem parte da cadeia produtiva do setor, formada por fabricantes de placas cerâmicas, argamassas e rejuntes, projetistas-especificadores, engenheiros, arquitetos, mestres de obra e assentadores. Esta constatação comprova ser necessário investir na formação profissional e criar condições de qualificar os profissionais envolvidos para minimizar a quantidade de patologias relacionadas ao sistema de revestimento cerâmico e, especificamente, ao sistema de revestimento cerâmico de fachada. / The present research aims to review the current literature on ceramic tile system pathologies, with the intention to contribute with studies related to the theme. In order to do this, the work sought to understand and to analyses the reality of a specific site of ceramic tile facade recuperation. The work is divided in two parts. The first is a review of the literature on ceramic tile system pathologies. The second is based on field research of three case studies of buildings located in Piracicaba, São Paulo, all of which confirm the trends appointed by the literature review. In all case studies it can be noticed that professionals involved lack the proper knowledge of the most common pathologies and of the ceramic tiling as a system. The research comprehends all professionals present in the industry and along the chain of production for ceramic tiling: producers of dry-set mortar, ceramic tile and ceramic tile grouts, designers, architects, engineers, construction workers. This has confirmed that it is necessary to invest in a qualified professional education, so as to reduce pathologies related to the ceramic tile system and, specifically, ceramic tiled building facades.
379

Zuverlässigkeitsanalyse thermisch belasteter keramischer Mehrschichtbauteile : experimentelle und numerische Untersuchungen am Beispiel der Lambdasonde /

Hiller, Peter, January 1900 (has links)
Thesis--Technische Universität Hamburg. / Includes bibliographical references.
380

Shifting Allegiances at La Milpa, Belize: A Typological, Chronological, and Formal Analysis of the Ceramics

Sagebiel, Kerry Lynn January 2005 (has links)
The primary goal of this dissertation is to present an outline of the culture history of the site of La Milpa and its immediate sustaining area through the elaboration and elucidation of a ceramic chronology and typology. However, an equally important aspect of this dissertation is a thorough critique of the type-variety/mode (T-V) system of classification upon which Maya ceramic analysis has been based over the last forty years. The analysis presented here was completed using a relational database (Microsoft Access). By using this database program, it became clear that it is necessary to rethink the basis and use of the type-variety system and how (or whether) it can be adapted as a tool for use in database driven analysis.

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