In this thesis, it is aimed to design lithium extraction from boron clays using statistical design of experiments and robust design methodologies. There are several factors affecting extraction of lithium from clays. The most important of these factors have been limited to a number of six which have been gypsum to clay ratio, roasting temperature, roasting time, leaching solid to liquid ratio, leaching time and limestone to clay ratio. For every factor, three levels have been chosen and an experiment has been designed. After performing three replications for each of the experimental run, signal to noise ratio transformation, ANOVA, regression analysis and response surface methodology have been applied on the results of the experiments. Optimization and confirmation experiments have been made sequentially to find factor settings that maximize lithium extraction with minimal variation. The mean of the maximum extraction has been observed as 83.81% with a standard deviation of 4.89 and the 95% prediction interval for the mean extraction is (73.729, 94.730). This result is in agreement with the studies that have been made in the literature. However / this study is unique in the sense that lithium is extracted from boron clays by using limestone directly from the nature, and gypsum as a waste product of boric acid production. Since these two materials add about 20% cost to the extraction process, the results of this study become important. Moreover, in this study it has been shown that statistical design of experiments help mining industry to reduce the need for standardization.

Thesis (Ph. D.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed March 2, 2009) Includes bibliographical references (p. 216-220).

Thesis (M.S.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (M.S.)--University of Missouri--Rolla, 2007. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed October 24, 2007) Includes bibliographical references.

Submitted by FLAVIO YOSHIKAZU YUKITA null (fyukita@ig.com.br) on 2017-12-18T01:04:18Z No. of bitstreams: 1 Dissertação Flávio Y Yukita.pdf: 4681342 bytes, checksum: d4cc7096fcb5b77eaadcf13d564a0748 (MD5) / Approved for entry into archive by Pamella Benevides Gonçalves null (pamella@feg.unesp.br) on 2017-12-18T12:23:01Z (GMT) No. of bitstreams: 1 yukita_fy_dr_guara.pdf: 4681342 bytes, checksum: d4cc7096fcb5b77eaadcf13d564a0748 (MD5) / Made available in DSpace on 2017-12-18T12:23:01Z (GMT). No. of bitstreams: 1 yukita_fy_dr_guara.pdf: 4681342 bytes, checksum: d4cc7096fcb5b77eaadcf13d564a0748 (MD5) Previous issue date: 2017-12-04 / Na busca pela competitividade, muitas empresas acabam adotando estratégias muito semelhantes baseadas nas práticas mais usuais e difundidas em seus respectivos negócios. Além dos recursos financeiros em si, as empresas também investem tempo e esforços para atingir desempenhos semelhantes às mais competitivas, as quais julgam ser o “benchmarking”, ou seja, a referência em seus negócios. Entretanto, buscar somente se espelhar nas melhores práticas das empresas de referência não possibilita tornar-se líder no negócio, pois para tanto seriam necessários outros ingredientes, outras estratégias que façam a diferença. Quando direcionado o foco para o produto em si, no caso deste estudo em específico da indústria automobilística que é um segmento bastante competitivo no mundo, faz-se necessário estratégias muito mais sofisticadas ou muitas vezes ainda inexistentes. Mencionado por diversos líderes e executivos de grandes empresas multinacionais como uma metodologia eficaz, o Design for Six Sigma, ou simplesmente DFSS, possibilita aprofundamentos e desdobramentos muito importantes para o entendimento dos mercados, de seus clientes, das suas necessidades e anseios. Pela flexibilidade do uso da metodologia do DFSS, torna-se possível desenvolver propostas e soluções para um dos diferenciais mais importantes neste mercado competitivo, a inovação. Em função da subjetividade presente sob alguns aspectos do conceito deste diferencial, propôs-se adotar a lógica fuzzy para se trabalhar com as variáveis mais importantes de natureza linguística e, combinado à relação sinal ruído de Taguchi, mensurar de forma quantitativa o grau de inovação inerentes aos produtos. Com este modelamento, validado por meio da análise de diversos sistemas veiculares que evoluíram ao longo da história automobilística, torna-se possível comparar produtos correntes com novas ideias e propostas do ponto de vista da inovação, fornecendo assim subsídios úteis para o processo de tomada de decisão / To pursue the competitiveness, many companies end up adopting similar strategies based on the most common and disseminated practices in their respective business. Beyond the financial resources, the companies also invest time and efforts in order to achieve similar performances of the most competitive ones which they deem to be "benchmarking", i.e. the reference in your business. However, simply adopting the best practices of those reference companies will not allow become a leader in their businesses, since it would require other ingredients, other strategies that make the difference. When it focuses on the product itself, specifically in the case of this study about the automotive industry, which is a very competitive segment in the world, it is necessary much more sophisticated strategies or even non-existent yet. Mentioned by several leaders and executives of multinational companies as an efficient methodology, the Design for Six Sigma, or simply DFSS, enables to understand their markets, their customers, respective necessities and yearnings, in a deep way and their deployments as well. By the flexibility of using DFSS methodology, it becomes possible to develop proposals and solutions to one of the most important differentials in this competitive market, the innovation. Due to the subjectivity around some aspects of the concept of that differential, it is proposed to adopt the fuzzy logic, to work on the most important linguistic variables and, combined with the Taguchi’s signal to noise relation, quantitatively measure the degree of innovation inherent in the products. By this modeling, validated through the analysis of several vehicular systems that have evolved throughout the automobile history, it becomes possible to compare current products with new ideas and proposals from the point of view of innovation, thus providing useful inputs to the decision-making process

Orientador: Vicente Afonso Ventrella / Resumo: A soldagem é um processo de fabricação utilizado em geral para união de peças e quando utiliza o laser como fonte de calor, denomina-se soldagem a laser. Um tipo bem conhecido é a soldagem a laser Nd:YAG pulsado, utilizado em diferentes tipos de materiais. Um dos materiais mais utilizados na engenharia é o aço inoxidável que possui alta resistência à corrosão, como por exemplo o aço AISI 904L, muito utilizado em tanques de armazenamento de ácido sulfúrico e fosfórico além de ampla aplicação na indústria petroquímica. Conduziu-se uma soldagem à laser Nd: YAG pulsado em chapas de aço inoxidável AISI 904L com espessura de 3 mm, variando-se quatro fatores tais como Potência de pico (PP) , Largura temporal (w), Frequência (F) e Velocidade de soldagem (S), todos eles distribuidos em três níveis de variação. Foi feito um Planejamento Experimental através do Método Taguchi, utilizando-se uma matriz ortogonal L9 e portanto realizando-se 9 experimentos em condições diferentes. A soldagem foi executada em atmosfera protetora com gás Argônio com fluxo de gás de 15 l/min, com deslocamento automatizado. A energia de cada pulso variou de 30 a 38,4J e a energia de soldagem entre 1,5 e 3,2 kJ/mm; as taxas de sobreposição variaram de 60 a 83%. As amostras foram preparadas para metalografia e atacadas com Ácido Oxálico 10% eletrolítico, com 6V e 7 segundos. Apesar da maioria das amostras romperem na Zona Fundida (ZF), a resistência mecânica ficou muito próxima do valor encontrado para o Metal B... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Welding is a manufacturing process used for joing parts and when a laser is utilized as a heat source, its called Laser Welding. A very known type is the pulsed Nd: YAG Laser Welding, that is used in many different kinds of materials. One of the most applied materials in engineering is the stainless steel that is highly corrosion resistant, for example the AISI 904L that is frequent used in sulfuric and phosphoric acid storage tanks, besides the petrochemical industry. Was carried out a pulsed Nd:YAG laser welding in AISI 904L stainless steel sheets with 3 mm of thickness, varying four factors such as Peak Power (PP), Time width (w), Frequency (F) and Welding Velocity (v), all of them distributed in three levels. A Design of Experiment was made through the Taguchi Method, using a L9 ortogonal array and therefore conducting nine experiments in different conditions. The welding was performed in argon gas flow of 15l/min, with automatic displacement. Pulse energy varied since 30 to 38,4J and welding energy from 1,5 to 3,2 kJ/mm; the overlay rates varied between 60 and 83%. Samples were prepared for metallography and etched with Oxalic Acid 10%, eletrolitic in 6v and 7 seconds. Although most of the samples broke in the Weld Zone (WZ), the mechanical resistance stayed very closer to the values found in Base Metal (BM). For BM, TZ and WZ, the mean values of hardness was 215, 242 and 238 HV respectively, pointing a homogeneous welding wherein the WZ presented only austenitic phase a... (Complete abstract click electronic access below) / Mestre

Tese (Doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. / Made available in DSpace on 2012-10-17T04:33:52Z (GMT). No. of bitstreams: 0Bitstream added on 2016-01-08T23:50:48Z : No. of bitstreams: 1 138275.pdf: 13252459 bytes, checksum: 3084f310694bfa5dc4c2d69c3acb2988 (MD5)

This thesis reviews Quality Function Deployment (QFD) and its relation with the Total Quality Management philosophy. In particular the thesis focuses on the inherent drawbacks of QFD and it investigates potential techniques and methods that could be integrated with QFD to overcome some of its problems. Fuzzy Logic/Fuzzy Sets and the Taguchi Method are identified as techniques and methods to be incorporated within the QFD process to provide a more consistent, quantitative and rigorous method to analyse subjective data in the QFD charts. Two approaches are developed that integrate Fuzzy Logic and Fuzzy Set theory with QFD to identify and rectify inconsistencies in the input data in the QFD charts. Another approach that integrates the Taguchi Method and QFD is further developed to set more precise technical target values in the QFD chart. Case studies are used to illustrate the results of the developed Fuzzy-QFD and the QFD-Taguchi approaches. The synergistic approaches take into account nteractions between requirements, which are not utilised in the traditional QFD charts. In addition, it was found that the resulting data in the QFD charts are sensitive to the interaction in the correlation matrices, therefore another method is also proposed to detect inconsistencies in the correlation matrices by utilising an inference mechanism and multi-valued logic theory. An integrated systems approach to QFD is eventually developed that forms a synergy between QFD, Fuzzy Logic/Fuzzy sets and the Taguchi Method. This results in a superior approach that combines the inherent benefits of each of the individual approaches. The integrated systems approach to QFD is a generic approach that can be used for other case studies provided that in addition to the relationship matrix and customer importance ratings, the correlation matrices and benchmarking data are readily available. As a result of this research, the subjectivity and ill-defined data in the QFD process have been partially resolved by the application of Fuzzy Logic/Fuzzy sets. The QFD analysis has been made more rigorous by integrating it to more quantitative techniques (Fuzzy Logic/Fuzzy sets) and method (Taguchi Method). It has been identified that demands are dependent on each other in the QFD charts and how including these dependencies in the problem can change the results. This problem has been addressed by considering interactions between the demands in the Fuzzy-QFD and QFD-Taguchi approaches developed. These interactions between demands have been identified and dealt with in the developed approaches, such that they no longer provide sub-optimal solutions.

Dissertação (mestrado) - Pontifícia Universidade Católica do Paraná, Curitiba, 2008 / Bibliografia: f. 134-139 / Robustez, no contexto de gerenciamento da cadeia de suprimentos, tem conotação de capacidade de Cadeia de Suprimentos em suportar pequenas variações do ambiente, variações de fatores não controláveis, sem que seu desempenho caminhe para níveis fora dos li / Robustness in the context of supply chain management, has connotation of Supply Chain ability to support small variations in the environment, changes in factors not controllable, without which their performance levels to walk out of bounds for what was de

Dissertação (mestrado) - Pontifícia Universidade Católica do Paraná, Curitiba, 2009 / Bibliografia: f. 85-89 / A concorrência no segmento de distribuição de encomendas, no mercado mundial de correios esta cada vez mais acirrada. Hoje em dia o cliente busca um serviço com o menor preço, uma maior qualidade, melhor atendimento e o melhor prazo de entrega. Neste cená / The concurrence of the distribution segment to orders in the mail world market is increasingly getting sturdier and sturdier. Currently the client seeks for a service with the lowest price, higher quality, better service and the best delivery term. In thi