Made available in DSpace on 2014-06-11T19:31:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-06-02Bitstream added on 2014-06-13T21:02:05Z : No. of bitstreams: 1 alves_al_dr_bauru.pdf: 8448992 bytes, checksum: 6f09d8f5231cbff24cebe7da8169bbec (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Compósitos condutores são materiais preparados para combinar as propriedades físicas dos polímeros com partículas condutivas. Neste trabalho, são apresentadas a preparação e caracterização de compósitos condutores contendo borracha natural (BN), raspa de couro (RC) e negro de fumo (NF). As Amostras foram conformadas em diferentes percentuais em massa dos constituintes BN, RC e NF: 38/60/2.0; 37.5/60/2.5; 37/60/3.0 e 36.5/60/3.5, respectivamente, aplicando uma pressão de 12 toneladas durante o 5 minutos à temperatura de 160°C, resultando em membranas com boa qualidade e com a espessura desejada. Os compósitos BN/RC/NF foram caracterizados por microscopia óptica (MO), microscopia eletrônica varredura (MEV), Microscopia de Força Atômica (AFM), espectroscopia Raman e infravermelho, termogravimetria (TG), calorimetria exploratória de varredura (DSC), análise dinâmico mecânica (DMA), testes mecânicos (Tensão versus deformação) e medidas de condutividade elétrica. A presença do NF no compósitos BN/ RC/NF, promoveu uma condutividade elétrica da ordem de 1.5x10-3 S.cm-1. Os ensaios mecânicos mostram que o compósito BN/RC/NF possui propriedades físicas intermediárias entre as membranas de BN e o couro. Verificou-se que as membranas do compósito BN/RC/NF são de baixo custo, e podem ser facilmente preparadas. Estes compósitos apresentaram boa estabilidade térmica, adequadas propriedade mecânica e condutividade elétrica, e são apropriadas para produzir luvas, mantas e pisos antiestáticos. Além disso, o compósito BN/RC/NF são obtidos a partir de resíduos de curtumes de couro contribuindo para a redução de um problema ambiental. / Conductive composites are materials prepared combining the physical properties of polymers and conductive particles. In this work the preparation and characterization of conducting composites containing natural rubber (NR), leather residue (LR) and carbon black (CB) are presented. Samples were conformed in different percentages of mass of the NR, LR and CB constituents: 38/60/2.0; 37.5/60/2.5; 37/60/3.0 and 36.5/60/3.5, respectively, applying a pressure of 12 tons during 5 minutes at the temperature of 160°C, resulting in membranes with good quality and with the desired thickness. The NR/LR/CB composites were characterized using optical microscopy (OM), scanning electronic microscopy (SEM), atomic force microscopy (AFM), Raman and infrared spectroscopy, thermogravimetry (TG), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), mechanical test (stress vs. strain) and he electric conductivity measurements. The presence of the CB in composites NR/LR/CB provided an electric conductivity of the order of 1.5x10-3 S.cm-1. Mechanical tests show that the NR/LR/CB composites have intermediate properties between the membranes of NR and the leather. It was found that NR/LR/CB membranes can be easily prepared with very low cost. They presented good thermal stability, adequate mechanical and electric conductivity properties that are appropriate to produce gloves, blankets and antistatic floors. In addition, the NR/LR/CB composites are obtained from leather residues from tanneries contributing for the reduction of an environmental problem.

As sucatas eletrônicas são hoje consideradas como matéria prima de alto valor agregado e economicamente viável, devido à presença de metais preciosos (e.g. prata, ouro, platina e paládio) em sua composição. Em geral, a comercialização é baseada no teor de metais preciosos e cobre, sendo assim, as análises químicas desempenham papel fundamental nesse ambiente de negócios. O método mais empregado para esse tipo de análise, considerado padrão é o Fire Assay, que consiste na extração dos analitos da matriz tornando determinação final praticamente livre de interferências. Entretanto o Fire Assay é um método susceptível a erros sistemáticos devido ao grande número de etapas, lento, caro e ambientalmente insustentável devido à quantidade de reagentes utilizados e resíduos gerados (e.g. chumbo). Diante dessas importantes desvantagens, o desenvolvimento de métodos que apresentem exatidão, precisão, boa frequência analítica, custo e que gere poucos resíduos se tornam necessários para a melhoria do controle de qualidade desses materiais. Sendo assim, o objetivo dessa pesquisa foi o desenvolvimento de método para a determinação simultânea de Au, Ag e Pd por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) e espectroscopia de fluorescência de raios-x por comprimento de ondas (WDSXRF), usando diferentes estratégias de preparação de amostras. As sucatas eletrônicas se caracterizam por serem heterogêneas, além disso, o material possui grande quantidade de metais como Al, Cu e Fe na composição fazendo com que a comunição seja um elemento chave no método e determinante da frequência analítica. Considerando esta dificuldade as amostras foram moídas em moinho oscilatório de discos de em diferentes tempos a fim de se investigar a influencia do tamanho de partículas para estudo de representatividade e precisão além da influencia do tamanho de partículas nas determinações por WDSXRF devido ao efeito sombra. Para os analises por WDSXRF as amostras com 40 minutos de moagem e preparadas com fusão com ferro e enxofre demonstraram boas correlações quando comprados ao Fire Assay. As dissoluções das amostras para analises em ICP OES ocorreu em duas etapas, a 1ª com HNO3 (aquecimento em chapa) para evitar passivação do ouro e a 2ª com 10 ml de água régia, usando o programa do forno de micro-ondas, com rampa de 160 °C a 210 °C (30 min). Foi observado que o excesso de Cl- formou complexos que inibiram perdas de Ag+ pro precipitação. As soluções finais foram analisadas no ICP OES e as concentrações obtidas foram comparadas ao método de Fire Assay. O método proposto mostrou boa correção para todos os elementos ao método padrão. A reprodutibilidade para Au foi de 4,1% (n=15 amostras) e a recuperação média comparada ao método padrão foi de 102%. Com base nos resultados obtidos pode-se dizer que o método proposto é comparável ao Fire Assay quanto à precisão e limites de detecção, apresentando melhores respostas quanto à frequência analítica, custo e geração de resíduos / Electronic scraps are today considered as raw material of high added value and economically viable, due to the presence of precious metals (e.g. silver, gold, platinum and palladium) in your composition. In general, the marketing is based on the content of precious metals and copper, therefore, chemical analysis plays a key role in this business environment. The method employed for this kind of analysis, considered standard, is the Fire Assay, which consists of the extraction of analytes in the array, making final determination virtually free of interference. However the Fire Assay is a method susceptible to systematic errors due to the large number of steps, slow, expensive and environmentally unsustainable due to the amount of reagents used and waste generated (e.g. lead). On these important disadvantages, the development of methods which have accuracy, precision, good analytical cost and frequency that generate few residues become necessary for the improvement of the quality control of these materials. Therefore, the objective of this research was the development of method for the simultaneous determination of Au, Ag and Pd by optical emission spectrometry with inductively coupled plasma (ICP OES) and fluorescence spectroscopy for x-ray wavelengths (WDSXRF), using different sampling strategies. Electronic scraps are characterized for being heterogeneous, in addition, the material possesses large amount of metals such as Al, Cu and Fe in the composition so that the communication is a key element in determining the frequency and analytical method. Considering this difficulty the samples were ground into oscillatory grinder discs at different times in order to investigate the influence of the particle size for study of representativeness and accuracy beyond the influence of the particle size determination by WDSXRF due to the shadow effect. For the analysis by WDSXRF samples with 40 minutes of grinding and prepared with merger with iron and sulfur showed good correlations when purchased the Fire Assay. The dissolutions of the samples for analysis in ICP-OES occurred in two steps, first with HNO3 (heating plate) to avoid gold passivation and the 2nd with 10 ml of aqua regia, by using the microwave oven, with 160 °C ramp to 210 °C (30 min). It was observed that the excess of Cl-formed complex that inhibit loss of Ag+ by precipitation. The final solutions were analysed at the ICP OES and the concentrations obtained were compared to the method of Fire Assay. The proposed method showed good fix for all elements to the standard method. Reproducibility for Au was 4.1% (n = 15 samples) and the average recovery compared to the standard method was 102%. Based on the results obtained can be said that the proposed method is comparable to the Fire Assay for accuracy and limits of detection, showing best answers regarding the analytical frequency, cost and waste generation.

Abstract In general, plastic materials can be classified into two categories: "thermoplastic" and "thermosetting plastic", the former is usually recyclable, when the latter isn¡¦t, and which results the solid waste problem. In the same way in thermoplastic divided into: generic plastic, generic engineering plastic, high-performance engineering plastic three categories. As technology advances, a variety of industries flourish as the world trend, various products are gradually moves forward. To improve performance, high-performance engineering plastic is more widely used and occupied part of the product cost. However, all the using of high-performance engineering plastic in Taiwan relies on imports, as any discarded after use like bury or burn in the landfill and incinerator results waste of resources and pollution problems. Therefore, recycling has become an important tool to make full use of limited resources. In literature review, we discuss the theory of technological innovation, according to the data of high-performance engineering plastic scrap recovery industry, using the AHP model to identify key success factors, as a supplementary tool for corporate decision-making to reduce costs and increase product competitiveness. After the AHP analysis, this study found that high-performance engineering plastic scrap recovery industry in the technology innovation process should emphasize the principles according to the order of (1) Technology Innovation Strategy (2) Technology Innovation Investment (3) Sources of Technology Innovation (4) Organization Design and Culture, and found the indicators to access each of these four principles. Which allows us to create higher value, to maximize corporate profits, and lower raw material costs of manufacturing, to achieve great competitive in the market share when countries around the world are now confronted with the rising pressure of increasing oil prices and actively promoting the environmental protection, energy conservation, and carbon reduction.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

No description available.

This thesis focuses on the experimental studies conducted on the development of low-cost seismic base isolation pads using scrap automobile tires. Seismic base isolation is a well-defined building protection system against earthquakes, on which numerous studies have been conducted. The majority of the previous studies focus on the performance improvement of the base isolation systems. However, this study aims at cost and weight reduction of seismic base isolation pads by recycling otherwise useless material: scrap tires. Elastomer-based isolators have been heavily studied and used for the last 25 years. Steel or fiber reinforcement inside the elastomer isolators provides high vertical stiffness, whereas rubber segments between reinforcement layers provide low horizontal stiffness for the seismic base isolation. Since 1960&rsquo / s, automobile tires have been produced by means of vulcanizing rubber with steel mesh in different forms which have a similar effect as the steel plates or fibers inside the conventional elastomer-based isolators. Therefore, rectangular shaped layers cut from tread sections of used tires and then piled on top of each other can function as an elastomeric bearing. Since the tires are being designed for friction, load transfer between scrap tire layers would be large enough to keep all layers intact. A minimal slip generated between the piled layers at high strain rates may even help to dissipate some extra energy. Axial compression, dynamic free vibration, static shear and shaking table tests have been conducted on Scrap Tire Pads (STP) prepared by using different tire brands for different number of layers and orientations. The results have shown that the average shear modulus of STPs change between 0.9MPa and 1.85MPa. At the end of the dynamic tests it has been noticed that the lateral stiffness of STPs can be simply adjusted by changing the number of tread layers placed on top of each other. The amount of wire mesh inside the tire tread layers is relatively low compared to the steel plates in regular elastomeric pads / consequently, axial load capacity of STPs has been found to be around 8.0MPa. Static large deformation shear experiments have been performed to obtain the horizontal stiffness and shear modulus values at high strains and the results are tabulated in the manuscript. Steel and rubber layers are produced separately and just put on top of each other without any adhesive to form the &frac14 / scaled versions of STPs which were used to isolate a &frac14 / scaled masonry house on the shaking table available in METU Structural Laboratory. The experiment showed that non-vulcanized rubber-steel layers put on top of each other can also be used to isolate structures. In conclusion, STPs may be used as a low-cost alternative to conventional elastomer-based pads for seismic isolation of massive structures (e.g. stone wall rural masonry) or for temperature induced deformation compensation of rural bridges. STP usage is demonstrated using three hypothetical design examples in the manuscript.

京都大学 / 新制・課程博士 / 博士(エネルギー科学) / 甲第23999号 / エネ博第435号 / 新制||エネ||82(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻 / (主査)教授 野平 俊之, 教授 萩原 理加, 教授 宇田 哲也 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

Made available in DSpace on 2014-10-09T12:44:56Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:50Z (GMT). No. of bitstreams: 1 07011.pdf: 7802124 bytes, checksum: c62d7e8f87af8c7b183c8aa37b808bff (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Este trabalho buscou analisar dois materiais para fabricação de navalhas para corte de sucata, de forma a identificar aquele que melhor atenda às solicitações de desgaste dentro de um custo competitivo. Foram realizados testes comparativos de desempenho entre navalhas de aço AISI S1 e SAE 4340, sendo este último o material base utilizado atualmente para a fabricação de navalhas para corte de sucata na Gerdau Aços Especiais Charqueadas. O estudo foi realizado durante o processamento de sucata em uma Prensa Tesoura Harris BSH 1123, sendo que as medições de desgaste foram realizadas nas arestas de corte com a utilização de um relógio comparador. Os resultados mostram que o aço ferramenta, apesar de seu elevado custo e necessidade de maior controle durante o tratamento térmico, é superior em todos os aspectos, apresentando a metade do desgaste do aço ligado quando utilizado nas mesmas condições e trazendo benefícios operacionais como a redução do tempo de troca das navalhas, sendo o material mais indicado para este fim. / Performance trials were carried out to identify the most suitable material for the manufacturing of blades for scrap cutting considering resistance for wear specifications as well as competitive cost. The materials tested were AISI S1 and SAE 4340, being the latter the material currently used for this application at Gerdau Aços Especiais Charqueadas. The study was conducted during scrap processing in a Harris BSH 1123 shearing press. In order to measure the cutting edge wear, a dial gauge was employed. The results show that the tool steel, despite its higher cost and more complex heat treatment process, is superior for all analyzed aspects, presenting less than half of the wear shown by the low alloyed steel when processing scrap under the same conditions. Other additional operational benefits also were obtained as a decrease in the set up time, being the material of choice for this task.

O setor siderúrgico é um grande consumidor de energia e envolve grandes volumes de insumos, emissões de poluentes e resíduos sólidos. As usinas siderúrgicas semi-integradas são recicladoras de aço, tendo a sucata como sua principal matéria-prima. Os trituradores de sucata são utilizados para minimizar as impurezas e ajustar as dimensões da sucata. Esta etapa de separação gera um grande volume de resíduos que não são aproveitados no processo siderúrgico. Assim, o objetivo deste trabalho foi caracterizar as frações do resíduo de um triturador de sucata de uma indústria siderúrgica da região do Vale dos Sinos-RS, para fins de um posterior reaproveitamento. Através de estudos de otimização do equipamento foi possível separar o material em quatro frações <20 mm (funil), >20 e <30 mm (EC1), >30 e <100 mm (EC2) e >100 mm (TC9). Estas frações foram analisadas em relação à composição das amostras, distribuição granulométrica, análise térmica, análise imediata, análise elementar, análise do poder calorífico superior, microscopia eletrônica de varredura (MEV) e a concentração de metais. Pode se concluir que a fração fina (<20 mm), possui potencial para incorporação em blocos cerâmicos estruturais. A fração entre 20 mm e 30 mm apresentam características compatíveis para o uso na indústria cimenteira. As amostras de maior granulometria, fração entre 30 e 100 mm e > 100 mm, apresentam potencial de uso para o reaproveitamento energético. Apontou-se oportunidade na recuperação de ferrosos e não ferrosos em todas as frações estudadas. Para o reaproveitamento do resíduo do shredder é necessário a separação deste em granulometrias diferentes. / The steel sector is a major consumer of energy and involves large volumes of inputs, pollutant emissions and solid waste. The semi-integrated steel mills are steel recyclers, with scrap as their main raw material. Scrap grinders are used to minimize impurities and adjust scrap dimensions. This separation stage generates a large volume of waste that is not used in the steelmaking process. Therefore, the objective of this work was to characterize the fractions of the waste from a scrap crusher from a steel industry in the Vale dos Sinos-RS region, for purposes of subsequent reuse. By means of equipment optimization studies it was possible to separate the material into four fractions <20 mm (funnel),> 20 and <30 mm (EC1),> 30 and <100 mm (EC2) and> 100 mm (TC9). These fractions were analyzed in relation to the composition of the samples, particle size distribution, thermal analysis, immediate analysis, elemental analysis, higher calorific value analysis, scanning electron microscopy (SEM) and metal concentration. It can be concluded that the fine fraction (<20 mm) has potential for incorporation of the raw material for the production of structural ceramic blocks. The smaller fractions (<20 mm and <30 mm) have compatible characteristics for use in the cement industry. Samples with higher grain size (> 30 mm and> 100 mm) show potential for use in energy recovery. It was pointed out an opportunity in the recovery of ferrous and non-ferrous in all fractions studied. For the reuse of the shredder residue it is necessary to separate it in different granulometry.