• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 53
  • 45
  • 18
  • 12
  • 6
  • 4
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 163
  • 30
  • 16
  • 13
  • 12
  • 11
  • 11
  • 11
  • 11
  • 11
  • 11
  • 11
  • 11
  • 10
  • 10
  • 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.
111

Innovative masonry shell construction in India's evolving building crafts : a case for tile vaulting

Jalia, Aftab January 2017 (has links)
This thesis uses the lens of building technology to examine cultural exchange and its relationship to the building crafts. By focusing on masonry vaulting in India, my research brings together two worlds – one that shines light on the variety of innovative masonry shell construction techniques that exist in the county and another that seeks to evaluate the scope of tile vaulting, an over 600-year old Mediterranean building technique, within India’s evolving building crafts culture. This thesis is organized in three parts: PART ONE Tile Vaulting and Relevance Today | A Brief History of Masonry Shells in India Part one introduces tile vaulting’s unique principles compared to other vaulting traditions while contextualizing its relevance to present day India. A survey of varied masonry vaulting techniques and modules, endemic and imported, practiced across India is presented against the backdrop of what is a predominantly reinforced concrete-based construction industry. PART TWO Modules, Methods and Motivations The second part of this research comprises case studies that include some of India’s most iconic buildings such as the Villa Sarabhai by Le Corbusier, the National Institute of Design by Gautam Sarabhai and Sangath by B.V. Doshi, each of which employed innovative construction techniques for its vaults. The production and use of the enigmatic ceramic fuses in India is examined for the first time alongside their indigenous cousins: burnt clay tubes. Together with Muzaffarnagar vaulting, the case studies reveal cultural motivations for architectural expression and production in postcolonial India. PART THREE Prototypes | Comparatives | Limitations & Extension of Research Part three presents five tile vaulting prototypes in India constructed with local artisans to gain understanding of its cultural reception, assess effective transfer of skills and potential internalisation. Recommendations for tile vaulting’s potential uptake into mainstream architectural production is evaluated by comparing findings against prevalent building methods and by contextualizing current architectural trends and social policy. Limitations and scope for extension of research are also discussed.
112

Caso Paiol de Telha: uma história dos descendentes de negros escravizados frente à expropriação de terras em Guarapuava, PR

Sene, Roberto Revelino 26 March 2008 (has links)
Made available in DSpace on 2017-07-21T14:42:50Z (GMT). No. of bitstreams: 1 Roberto Rivelino.pdf: 422733 bytes, checksum: 77fed3b0307296c397430575889bad71 (MD5) Previous issue date: 2008-03-26 / This dissertation presents the Case Storeroom of Tile, looking for to contemplate on a history of the black’s descendants of enslaved front to the expropriation of lands in Guarapuava, PR. We discussed some of the arguments during the research on the processes of construction of identities and of social organization in the disputes for lands in the State of Paraná, in Guarapuava, also detaching the black's roll in the Brazilian society. We problematized the historical visions about the relationship existent among slaves and their lord, considering how these visions started composing the main ideas about the formation of the Brazilian people, as well as its influence in specific cases as the one of the Storeroom of Tile. Starting from this case, we tried, to present a history so called “the minorities” and how these minorities are treated in the dynamics of the social processes, focusing our study in the form how that group of descendants of enslaves of the interior of paraná molded their strategies of defense, survival and reply to the system, forming their own identity trying to insert in the local society. For the historical reconstruction of the Case Storeroom of Tile, we studied mainly a dossier prepared by the Pastoral Commission of the Earth, analyzing the speeches and the approaches used in it to justify the organization of a movement with juridical existence in order to claim the inherited and expropriated lands, the ‘Association Heleodoro Storeroom of Tile’, whose actions we tried to understand and to problematize, studying which are their inspiring sources related to the movements of afro-descendants, syndical and country workers without land demands. This research brings us to understand that the traditional families of Guarapuava created a net of power in order to isolate and expropriate blacks-descendants of having their lands. Today these lands are occupied by the “Cooperativa Agrária Mista de Entre Rios”, descendants of European immigrants, showing that some groups are considered by the elite of the local society as worthy of be landowners, in a context where the economical expropriation of afro-descendants people go trough ethnical questions and racial prejudices are deep-rooted in the regional history / Esta dissertação apresenta o Caso Paiol de Telha, buscando refletir sobre uma história dos descendentes de negros escravizados frente à expropriação de terras em Guarapuava, PR. Discutimos alguns dos argumentos levantados durante a pesquisa sobre os processos de construção de identidades e de organização social nas disputas por terras no Estado do Paraná, em Guarapuava, também destacando o papel do negro na sociedade brasileira. Problematizamos as visões históricas sobre o relacionamento existente entre os escravizados e seus senhores, tentando considerar como estas visões passaram a compor as idéias em circulação sobre a formação do povo brasileiro, bem como sua influência em casos específicos como o do Paiol de Telha. Buscamos, a partir deste caso, apresentar uma história das chamadas minorias e como estas são tratadas na dinâmica dos processos sociais, focalizando nosso estudo na forma como esse grupo de descendentes de escravizados do interior paranaense moldou suas estratégias de defesa, sobrevivência e contestação ao sistema, formando uma identidade própria para tentar se inserir na sociedade local. Para essa reconstrução histórica do Caso Paiol de Telha, estudamos principalmente um dossiê elaborado pela Comissão Pastoral da Terra, analisando os discursos e as abordagens usadas nele para justificar a organização de um movimento com existência civil de reivindicação das terras herdadas e expropriadas, a Associação Heleodoro Paiol de Telha, cujas ações tentamos compreender e problematizar, estudando quais suas fontes inspiradoras relacionadas às demandas dos movimentos negro, sindical e de trabalhadores rurais sem terra. A pesquisa nos levou a compreender que as famílias conservadoras de Guarapuava criaram uma rede de poder para isolar e expropriar os negros descendentes de escravizados que eram herdeiros de terras. Apontou-se o fato de que hoje estas estão ocupadas pela Cooperativa Agrária Mista de Entre Rios, de descendentes de imigrantes europeus, demonstrando que grupos são considerados pela elite da sociedade local como dignos de serem proprietários de terras, num contexto em que a expropriação econômica de afrodescendentes se cruza com questões étnicas e preconceitos raciais enraizados na história regional.
113

Investigation Of Strenghthening Techniques Using Pseudo-dynamic Testing

Kurt, Efe Gokce 01 June 2010 (has links) (PDF)
Pseudo-dynamic testing was employed to observe the seismic performance of three different retrofit methods on two story three bay reinforced concrete frame structures. The three test frames have hollow clay tile (HCT) infills in the central bay. All of the test frames represent the seismic deficiencies of the Turkish construction practice such as use of plain reinforcing bars, low strength concrete and insufficient confining steel. Two non-invasive and occupant friendly retrofit schemes suggested in the Turkish Earthquake Code, namely use of Fiber Reinforced Polymers and precast concrete panels integrated on the HCT infills and traditional approach of adding concrete infill wall were employed. Specimens were subjected to three different scale levels of North-South component of Duzce ground motion. Reference specimen experienced severe damage at 100% scale level and reached collapse stage due to the loss of integrity of the infill wall and significant damage on the boundary columns. The retrofitted test structures were able to survive the highest level 140% Duzce ground motion. Test results confirmed the success of the retrofit methods for simulated earthquake loads.
114

国分尼寺の造営過程に関する基礎的考察

Kajiwara, Yoshimitsu, 梶原, 義実 31 March 2014 (has links)
No description available.
115

O Design de superfície nos ladrilhos hidráulicos: um estudo do Patrimônio Industrial Campinense. / The design of surface in the hydraulic tiles: a study of the Industrial Patrimony from Campina Grande - Paraíba - Brazil.

MEDEIROS, Arthur Thiago Thamay. 10 June 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-06-10T17:35:13Z No. of bitstreams: 1 ARTHUR THIAGO THAMAY MEDEIROS - DISSERTAÇÃO PPGDsign 2018..pdf: 119262402 bytes, checksum: 2bbca76fb01ef0bbd2554ccff0da302d (MD5) / Made available in DSpace on 2018-06-10T17:35:13Z (GMT). No. of bitstreams: 1 ARTHUR THIAGO THAMAY MEDEIROS - DISSERTAÇÃO PPGDsign 2018..pdf: 119262402 bytes, checksum: 2bbca76fb01ef0bbd2554ccff0da302d (MD5) Previous issue date: 2018-02-27 / A presente pesquisa apresenta uma análise visual dp ladrilho hidráulico de Campina Grande, abrangendo os exemplares da Fábrica Metro Materiais, a antiga "Fábrica de Mosaicos Resistência", inaugurada em 1947. Popularmente conhecido como mosaicos, essa tipologia de revestimento foi um elemento construtivo importante na constituição histórica da arquitetura de Campina. A cidade foi palco de grande desenvolvimento em diversos setores industriais e, por isso, torna-se importante a investigação da trajetória das fábricas de ladrilhos hidráulicos que funcionaram no município. A pesquisa investiga os padrões e demais aspectos iconográficos dos ladrilhos produzidos pela Fábrica Metro, com o objetivo de analisar, registrar e compreender os desenhos de maneira técnico-construtiva. Justifica-se a pesquisa, conforme o seu valor científico e académico, devido à escassez de literatura sobre o tema de análises visuais a respeito desses artefatos, resultando na preservação dos modelos, através do registro do patrimônio industrial campinense abordado na pesquisa. Assim, a contribuição dos resultados, bem como os conceitos apresentados sobre as técnicas de composição dos ladrilhos hidráulicos, abre caminhos para conhecimentos que podem ser aplicados em demais projetos distintos na área do design de superfície. / The present research presents a visual analysis of the hydraulic tile of Campina Grande, covering the examples of the Metro Materiais Factory, the former "Fábrica de Mosaicos Resistência", inaugurated in 1947. Popularly known as mosaics, this type of tile coating was an important constructive element in the historical constitution of the Campina architecture. The city was a stage of great development in several industrial sectors and, therefore, it becomes important to investigate the trajectory of the hydraulic tile factories that worked in the municipality. The research investigates the patterns and other iconographic aspects of the tiles produced by Metro Materiais, with the purpose of analyzing, registering and understanding the drawings in a technical-constructive manner. The research, according to its scientific and academic value, is justified due to the scarcity of literature on the subject of visual analysis regarding these artrfacts, resulting in the preservation of the models, through the record of the Campina Grande's industrial patrimony studied in the research. Thus, the contribution of the results, as well as the concepts presented on the techniques of composition of the hydraulic tiles, opens paths for knowledge that can be applied in other projects in the area of surface design
116

Efeito da adi??o de cargas minerais leves na resist?ncia mec?nica de grautes para cimenta??o de po?os offshore

Cabral, Kleber Cavalcanti 22 July 2011 (has links)
Made available in DSpace on 2014-12-17T14:09:13Z (GMT). No. of bitstreams: 1 KleberCC_TESE.pdf: 2548288 bytes, checksum: f214aa096a5ffb2a48cfa0e23356dfc4 (MD5) Previous issue date: 2011-07-22 / The preparation of cement slurries for offshore well cementing involves mixing all solid components to be added to the mixing water on the platform. The aim of this work was to study the formulation of pre-prepared dry mixtures, or grouts, for offshore oilwell cementing. The addition of mineral fillers in the strength of lightweight grouts applied for depths down to 400 m under water depths of 500 m was investigated. Lightweight materials and fine aggregates were selected. For the choice of starting materials, a study of the pozzolanic activity of low-cost fillers such as porcelain tile residue, microsilica and diatomaceous earth was carried out by X-ray diffraction and mechanical strength tests. Hardened grouts containing porcelain tile residue and microsilica depicted high strength at early ages. Based on such preliminary investigation, a study of the mechanical strength of grouts with density 1.74 g/cm3 (14.5 lb/gal) cured initially at 27 ?C was performed using cement, microsilica, porcelain tile residue and an anti-foaming agent. The results showed that the mixture containing 7% of porcelain tile residue and 7% of microsilica was the one with the highest compressive strength after curing for 24 hours. This composition was chosen to be studied and adapted for offshore conditions based on testes performed at 4 ?C. The grout containing cement, 7% of porcelain tile residue, 7% of active silica and admixtures (CaCl2), anti-foaming and dispersant resulted satisfactory rheology and mechanical strength after curing for 24 hours of curing / A prepara??o de pastas de cimento para po?os offshore envolve a mistura de todos os componentes s?lidos da pasta e a prepara??o da ?gua de mistura feita na pr?pria plataforma. O objetivo desse trabalho ? apresentar um estudo de formula??o de misturas secas pr?preparadas, ou grautes, para a cimenta??o de po?os offshore. Foi avaliado o efeito da adi??o de cargas minerais leves na resist?ncia mec?nica de grautes para cimenta??o prim?ria inicial (at? 400 m) com l?minas d ?gua acima de 500 m. Foi realizada uma sele??o de materiais leves e finos, em substitui??o aos agregados utilizados nos grautes da constru??o civil. Para a escolha dos materiais de partida, primeiramente foi realizado um estudo da atividade pozol?nica de materiais de baixo custo, como res?duo cer?mico de porcelanato, s?lica ativa e diatomita, por meio de difratometria de raios X e resist?ncia mec?nica ? compress?o. Verificou-se que as misturas com adi??o de res?duo de porcelanato e s?lica ativa apresentaram maiores resist?ncias nas primeiras idades. Com isso, foi desenvolvido um estudo da resist?ncia mec?nica ? compress?o de grautes com massa espec?fica 1,74 g/cm3 (14,5 lb/gal), curadas, inicialmente, a 27?C e compostas por cimento, res?duo de porcelanato e s?lica ativa, aditivadas com anti-espumante. Os resultados revelaram que a mistura com 7% de res?duo de porcelanato e 7% de s?lica ativa foi a que apresentou a maior resist?ncia mec?nica ? compress?o em ensaio realizado com 24 horas de cura. Escolhida a composi??o a ser estudada, ela foi adaptada ?s condi??es de po?o offshore, cujos ensaios foram realizados a 4?C. A mistura composta por cimento, 7% de res?duo de porcelanato e 7% de s?lica ativa foi aditivada com acelerador de pega (CaCl2), anti-espumante e dispersante. Os ensaios revelaram que essa composi??o mostrou-se satisfat?ria quanto ? resist?ncia mec?nica ? compress?o com 24 horas de cura, reologia, tempo de pega e volume de ?gua livre
117

Obten??o de placas cer?mico a partir de formula??es de massas triaxiais de res?duos de caulim, chamote de telha e cinza vegetal

Cunha, Jos? Eduardo Vilar 10 August 2009 (has links)
Made available in DSpace on 2014-12-17T14:57:49Z (GMT). No. of bitstreams: 1 JoseEVC_capa_ate_resumo.pdf: 114113 bytes, checksum: 65c5a81ce8eceb533010608034415ec0 (MD5) Previous issue date: 2009-08-10 / The production of red ceramic is an industrial activity that causes an intense impact. The manufacture of its products considerably increases the demand for natural resources, mainly with the extraction of raw material. The ceramic material produced generates waste, such as ash firewood and chamote. The residue from the beneficiation of kaolin is deposited in a poor, degrades the environment and contaminate water sources and soil, constituting in this manner, ecological disasters. The main objective of this work is to develop the formulation of a ceramic product consisting solely of industrial solid wastes, from ceramic tiles, (chamote) residue of kaolin and ash firewood. It is assumed that this product made in the laboratory can be used in coatings, wall and floor. The aim is to facilitate the replacement of the raw material of original composition of a ceramic body, for waste, while the process of production equal to the conventionally used, so that the properties of the product are reproduced. This work is characterized waste as its chemical composition, analysis of particle size, X-ray diffraction and thermal behavior. Several formulations were studied. The mass of waste was prepared by dry process, pressed to 25 MPa, and then burned in muffle type oven to 850, 950, 1050 and 1150 ?C. The results showed that it is technically possible to produce porous tiles only with waste. It was found that the formulations of bodies play a key role in the properties of the final product, as well as the sintering temperature and heating rates. RN in the waste of kaolin is estimated at 15,000 t/month, about 3,000 gray t/month and chamote with 10 million pieces/month damaged. The presence of carbonates of calcium and magnesium at 1050 ? C results in an appropriate porosity and mechanical strength. The formulation M3JE, composed of 69% waste of kaolin, 7.7% and 23.3% of chamote of gray, became suitable for porous materials with the strength and absorption within the level of national and international standards / A produ??o de cer?mica vermelha ? uma atividade industrial que provoca um intenso impacto ambiental. A confec??o de seus produtos aumenta sobremaneira a demanda por recursos naturais, principalmente com a extra??o da mat?ria prima, argila. O material cer?mico produzido gera res?duo, como o chamote e a cinza vegetal. O res?duo proveniente do beneficiamento do caulim que ? depositado de forma inadequada degrada o meio ambiente e contamina os mananciais da ?gua e do solo, constituindo dessa maneira, desastres ecol?gicos. O principal objetivo deste trabalho ? desenvolver formula??o de um produto cer?mico constitu?do exclusivamente de res?duos s?lidos industriais, oriundos de telhas cer?micas, (chamote), res?duo de caulim e cinza vegetal. Presume-se que este produto confeccionado em laborat?rio possa ser aproveitado em revestimentos de parede e piso. Pretende-se assim viabilizar a substitui??o das mat?rias-primas da composi??o original de uma massa cer?mica, por res?duos, mantendo-se o processo de produ??o igual ao convencionalmente utilizado, a fim de que as propriedades do produto sejam reproduzidas. No presente trabalho caracteriza-se os res?duos quanto a sua composi??o qu?mica, an?lise de tamanho de part?cula, difra??o de raios X e comportamento t?rmico. Diversas formula??es foram estudadas. A massa de res?duos foi preparada pelo processo via seca com corpos de provas prensados a 25 MPa, posteriormente queimados em forno mufla a 850, 950, 1050 e 1150 ?C. Os resultados obtidos evidenciaram tecnicamente que ? poss?vel se produzir placas cer?micas porosos exclusivamente com res?duos. Verificou-se que as formula??es das massas desempenham um papel fundamental nas propriedades do produto final, assim como as temperaturas de sinteriza??o e taxas de aquecimento. No RN os res?duos de caulim s?o estimados em 15000 t/m?s, a cinza com aproximadamente 3000 t/m?s e o chamote com 10 milh?es pe?as/m?s danificadas. A presen?a de carbonatos de c?lcio e magn?sio em 1050 ?C resulta em uma adequada porosidade e resist?ncia mec?nica. A formula??o M3JE, composta de 69% de res?duo de caulim, 7,7% de chamote e 23,3 % de cinza, se tornou adequado aos materiais porosos, com a resist?ncia mec?nica e absor??o dentro do patamar das normas nacionais e internacionais
118

Estudo da formula??o de massas cer?micas provenientes da regi?o do Serid?-RN para fabrica??o de telhas

Andrade, Felipe Lira Formiga 06 March 2009 (has links)
Made available in DSpace on 2014-12-17T14:57:50Z (GMT). No. of bitstreams: 1 FelipeLFA.pdf: 4959653 bytes, checksum: 0da7f126d56ee6a849bfaf9a5d53da1d (MD5) Previous issue date: 2009-03-06 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This work has for objective study compared the characteristics and technological properties of ceramic bodies from the region of Serid?-RN. The region under study has identified 23 cities where they were 80 ceramics industries. To define the universe of search, there was a survey of pottery that are part of APL Serid? next to the IEL. The characteristics and operating conditions of ceramics industries of the region were identified through a socio-economic questionnaire applied locally, which addressed issues such as: profiles of companies, production process etc. The analysis of information collected from 24 companies identified in seven cities shows that the vast majority of industries is small, with family structure, obsolete equipment and labo, little qualified. Most of the pottery works with low technical knowledge, poor control of the production process and product technology. The raw collected were submitted to analysis of X ray diffraction, chemical composition, termical analysis, particle size distribution and plasticity. Then were produced five formulations and made by uniaxial pressure at 25 MPa for firing in temperatures varying from 850 to 1050 ?C. The firing technological properties evaluated were: mass loss to fire, lineal shrinkage, apparent density, apparent porosity, water absorption and flexural strength (3 points). The results indicated that the raw materials from the region have significant similarities in the composition chemical and mineralogical. Furthermore, it indicates the possibility of the use of cycles of firing faster and efficient than the current, limited to some clay mass burning of certain conditions / Este trabalho teve como objetivo estudar comparativamente as caracter?sticas e propriedades tecnol?gicas de massas cer?micas para telhas da regi?o do Serid?-RN. A Regi?o em estudo possui 23 munic?pios onde foram identificadas 80 ind?strias cer?micas. Para defini??o do universo da pesquisa, fez-se um levantamento das olarias que fazem parte da APL Serid? junto ao IEL do Estado. As caracter?sticas e condi??es de funcionamento das ind?strias cer?micas da regi?o foram identificadas atrav?s de um question?rio s?cio-econ?mico aplicado in loco, que abordava aspectos como: perfil das empresas, processo produtivo etc. A an?lise das informa??es coletadas em 23 empresas identificadas em sete munic?pios permite concluir que a grande maioria das ind?strias ? de pequeno porte, com estrutura familiar, equipamentos obsoletos e m?o-de-obra pouco qualificada. Grande parte das olarias opera com baixo conhecimento t?cnico, prec?rios controles do processo produtivo e tecnol?gico dos produtos. As mat?rias-primas coletadas foram submetidas a ensaios de difra??o de raios X, composi??o qu?mica, an?lise t?rmica, distribui??o de tamanho de part?culas e plasticidade. Em seguida foram produzidas cinco formula??es e confeccionados corpos-de-prova por prensagem uniaxial a 25 MPa para queima variando de 850 ?C a 1050?C. As propriedades tecnol?gicas de queima avaliadas foram: perda de massa ao fogo, retra??o linear, massa espec?fica aparente, porosidade aparente, absor??o de ?gua e carga de ruptura ? flex?o (3 pontos). Os resultados indicaram que as mat?rias-primas provenientes da regi?o apresentam significativas semelhan?as quanto ? composi??o qu?mica e mineral?gica. Al?m disso, indica-se a possibilidade da utiliza??o de ciclos de queima mais r?pidos e eficientes que os atuais, limitando algumas massas argilosas para certas condi??es de queima
119

Estudo do potencial de utiliza??o do res?duo da extra??o de esmeraldas na fabrica??o de cer?mica de revestimento / Study of the potential use of waste from the extraction of emerald in the manufacture of ceramic tile

Cavalcante, Ronaldo Fonseca 09 March 2010 (has links)
Made available in DSpace on 2014-12-17T14:57:56Z (GMT). No. of bitstreams: 1 RonaldoFC_DISSERT.pdf: 4616662 bytes, checksum: 0873d4d0b759a28864c474fb890be216 (MD5) Previous issue date: 2010-03-09 / Universidade Federal do Rio Grande do Norte / Companies involved in emerald mining and treatment represent an important area of industrial development in Brazil, with significative contribution to the worldwide production of such mineral. As a result, large volumes of emerald waste are constantly generated and abandoned in the environment, negatively contributing to its preservation. By the other side the interest of the use of mining waste as additive in ceramic products has been growing from researchers in recent years. The ceramic industry is constantly seeking to the marked amplification for the sector and perfecting the quality of the products and to increase the variety of applications. The technology of obtaining of ceramic tiles that uses mining residues assists market niches little explored. In this scenario, the objective of the present study was to characterize the residue generated from emerald mining as well as to assess its potential use as raw material for the production of ceramic tiles. Ceramic mixtures were prepared from raw materials characterized by X-ray fluorescence, X-ray diffraction, particle size analysis and thermal analysis. Five compositions were prepared using emerald residue contents of 0%, 10%, 20%, 30% and 40%. Samples were uniaxially pressed, fired at 1000, 1100 and 1200?C and characterized aiming at establishing their mineralogical composition, water absorption, apparent porosity, specific mass, linear retraction and modulus of rupture. The results shows that the emerald residue, basically consisted of 73% of (SiO2 + Al2O3) and 17,77% of (MgO + Na2O+ K2O) (that facilitates sintering), can be added to the ceramic tile materials with no detrimental effect on the properties of the sintered products / Empresas envolvidas na minera??o de esmeralda e beneficiamento representam uma importante ?rea de desenvolvimento industrial no Brasil, com significativa contribui??o para a produ??o mundial desse min?rio. Como resultado, grandes volumes de res?duos de esmeralda s?o constantemente gerados e abandonados no ambiente, contribuindo negativamente para a sua preserva??o. Por outro lado o interesse no uso do res?duo de minera??o como aditivo na produ??o de material cer?mico tem crescido entre os pesquisadores nos ?ltimos anos. A ind?stria cer?mica est? constantemente buscando a amplia??o do mercado para o setor e tentando aperfei?oar a qualidade dos produtos e aumentar a variedade de aplica??es. A tecnologia de obten??o de cer?mica de revestimento que usa res?duos de minera??o ? um mercado ainda pouco explorado. Neste cen?rio, o objetivo do presente estudo foi caracterizar o res?duo gerado a partir de minera??o de esmeralda, bem como para avaliar seu potencial uso como mat?ria-prima para a produ??o de revestimentos cer?micos. Misturas cer?micas foram preparadas a partir de mat?rias-primas caracterizadas por fluoresc?ncia de raios X, difra??o de raios X, an?lise granulom?trica e an?lise t?rmica. Cinco composi??es foram preparadas utilizando ?ndices de res?duos de esmeraldas de 0%, 10%, 20%, 30% e 40%. As amostras foram prensadas uniaxialmente, sinterizadas em 1000, 1100 e 1200 ? C e caracterizadas visando estabelecer sua composi??o mineral?gica, absor??o de ?gua, porosidade aparente, massa espec?fica, retra??o linear e m?dulo de ruptura. Os resultados mostraram que o res?duo de esmeraldas composto basicamente de 73% de (SiO2 + Al2O3) e 17,77% de (MgO+Na2O+K2O) (que facilitam a sinteriza??o) pode ser incorporado na massa de revestimento cer?mico sem comprometimento das propriedades do produto sinterizado
120

Contribution à la théorie des langages de tuiles / Contribution to the theory of tile languages

Dubourg, Etienne 12 July 2016 (has links)
Les tuiles sont des structures finies, linéaires ou arborescentes, possédantune notion de chevauchement. Elles sont utiles en informatique pourreprésenter des objets musicaux, comme étudié par Janin [2016]. Nous étudieronsles ensembles de tuiles, en particulier comme représentations d’objetsalgébriques, en se basant sur la théorie des semigroupes inversifs.Nos principaux objets d’étude seront les langages de tuiles, et les reconnaisseursappropriés, que l’on peut définir en adaptant aux tuiles des notionsbien connues sur les langages de mots. Nous nous intéresserons à la reconnaissancepar automate, en présentant des automates sur les tuiles linéaires etarborescentes. Nous remarquerons les limites de la puissance de tels automates.Tandis que la notion de reconnaissance par morphisme de monoïdes estinadaptée aux langages de tuiles, nous définirons celle de reconnaissabilité parprémorphisme, ou quasi-reconnaissabilité. Nous étudierons les liens entre quasireconnaissabilitéet reconnaissabilité par automate de tuile.Nous explorerons enfin les propriétés de clôtures de l’ensemble de langagesde tuiles reconnus par automate, et de ceux reconnus par prémorphisme. Ladernière partie sera essentiellement consacrée aux tuiles linéaires, et présenterale monoïde des décompositions restreintes, un outil pour le produit de langagesde tuiles linéaires. / Tiles are finite, linear or tree-like structures, with a notion of overlapping.In computer science, they offer a useful way to represent musical objects,as studied by Janin [2016]. We will study the sets of tiles, especially asrepresentations of algebraic objects, based on the theory of inverse semigroups.Our main focus will be languages of tiles, and the appropriate recognizers,than can be defined by the adaptation to tiles of well-known notions over languagesof words. We will look into the recognition by automata, by presentingautomata over linear and tree-like tiles. We will remark the limits of the powerof such automata.While the notion of recognizability by morphisms is unsuitable to languagesof tiles, we will define recognizability by premorphisms, or quasi-recognizability.We will study the links between quasi-recognizability and recognizability bytile automata.We will finally look into the closure properties of the set of tile languages recognizedby automata, and of the set of quasi-recognizable languages. The lastpart will be dedicated to linear tiles, and will present the monoid of restricteddecompositions, a tool for the product of linear tile languages.

Page generated in 0.0669 seconds