Droplet mobility on surfaces is often hampered by the pinning of the droplet’s contact line. External forces would be needed if motion is to continue. The development of Slippery Liquid-Infused Porous Surfaces (SLIPS) or Lubricant-Impregnated Surfaces (LIS) has since enabled the studies of droplets in low friction situations with virtually no contact angle hysteresis. This thesis presents three separate studies of droplet mobility in the absence of contact line pinning, made possible by the use of SLIPS/LIS. Firstly, the first study of evaporation of sessile droplet under true constant contact angle mode was demonstrated. The lack of contact line pinning meant that droplet’s contact line receded smoothly with no stick-slip stepwise retreat as it evaporated. The absence of a contact angle due to the presence of the wetting ridge around the droplet led to the concept of an extrapolated apparent contact angle. The subsequent study saw the experimental realisation of both inward and outward motion of droplet having an apparent contact angle above 90° confined in a wedge geometry formed by a pair of SLIPS/LIS. Out of equilibrium, droplet was free to travel within the wedge until settling at a prescribed location, regardless to its initial position. This enabled the accurate control over the transport and localisation of the droplet by a reconfiguration of the system. The lack of pinning also suggests that the dynamics of the droplet is dictated purely by viscous dissipation. The final study showed that SLIPS/LIS can be created on macro-patterned surfaces. The macro-patterning introduced menisci features in the impregnating liquid layer which interact with the wetting ridge around a droplet. These interactions were used to induce motion to the droplet. It was also found that accurate positioning of the droplet on an otherwise completely slippery surface can be achieved using well-defined surface topography.

The present research explores numerically and experimentally the process of melting and solidification of Phase Change Materials (PCM) in a latent heat thermal energy storage system (LHTESS). Further, the study will investigate various methods of intensification of heat transfer in such materials by means of metallic fins, filling particles or nanoparticles and by choosing the optimal system geometry for a rapid development of free convection flows during the melting process. The study includes three main parts. First, 3D CFD modelling was performed for the melting performance of a shell-and-tube thermal storage system with n-Octadecane as a PCM. The predicted model was in very good agreement with experimental data published in open literature. A series of numerical calculations were then undertaken to investigate the effect of nanoparticles on the heat transfer process. Dimensionless heat transfer correlations were derived for the system with Pure PCM and PCM mixed with nano-particles. In the second part of this study the experimental studies were carried out in order to investigate the performance of the laboratory thermal storage system with paraffin as the PCM. The thermal storage system was connected to evacuated tube solar collectors and its performance was evaluated in various conditions. 3D CFD model of the system was developed and numerical simulations were run for constant heat source conditions. Computational results were compared with experimental data obtained on the test rig at Northumbria University. Comparison revealed that the developed CFD model is capable to describe process of heat transfer in the system with high accuracy and therefore can be used with high confidence for modelling further cases. Finally, 3D CFD model was developed to predict the transient behaviour of a latent heat thermal energy storage system (LHTESS) in the form of a rectangular container with a central horizontal pipe surrounded by paraffin as PCM (melting temperature is 60 oC). Water was used as a heat transfer fluid (HTF). The enhancement of heat transfer in specific geometries by using external longitudinal fins on the tube and metallic porous matrix were numerically investigated. The influence of the number of fins and porosity of the matrix on the temperature distribution, melting process, melting time and natural convection phenomena were studied. Dimensionless heat transfer correlations were derived for calculation of the Nusselt number as function of Fourier, Stefan and Rayleigh numbers. These correlations to be used in the further designing process of similar thermal storage units at Northumbria University.

Submitted by Cátia Araújo (catia.araujo@unipampa.edu.br) on 2017-01-26T11:47:11Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Avaliação do potencial do uso da sílica de casca de arroz obtida através da queima controlada como substituição parcial ao cimento Portland na produção de concretos au.pdf: 5610666 bytes, checksum: 59bf1f9b8c485e95150b2a114381adde (MD5) / Approved for entry into archive by Cátia Araújo (catia.araujo@unipampa.edu.br) on 2017-01-26T11:47:27Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Avaliação do potencial do uso da sílica de casca de arroz obtida através da queima controlada como substituição parcial ao cimento Portland na produção de concretos au.pdf: 5610666 bytes, checksum: 59bf1f9b8c485e95150b2a114381adde (MD5) / Made available in DSpace on 2017-01-26T11:47:27Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Avaliação do potencial do uso da sílica de casca de arroz obtida através da queima controlada como substituição parcial ao cimento Portland na produção de concretos au.pdf: 5610666 bytes, checksum: 59bf1f9b8c485e95150b2a114381adde (MD5) Previous issue date: 2016-09-01 / O presente estudo tem como objetivo avaliar o potencial uso da Sílica de Casca de Arroz (SCA), obtida de queima controlada, como material de substituição parcial em massa ao Cimento Portland (CP) na produção de concretos autoadensáveis (CAA). A SCA empregada neste trabalho foi produzida em condições controladas em um sistema de combustão com leito fluidizado, tendo como resultado uma sílica altamente amorfa e de boa qualidade. Foram avaliados os resultados do comportamento reológico do CAA no estado fresco e a resistência mecânica no estado endurecido de um concreto de referência, sem o uso de SCA, e de cinco concretos produzidos a partir de substituições parciais de 5%, 10%, 15%, 20% e 25% de SCA em relação à quantidade de massa do cimento. Em todos os traços foram utilizado 15% de cinza volante (CV) adicionada à massa do material aglomerante, a fim de auxiliar na diminuição do atrito entre as partículas dos agregados com o cimento. O traço do concreto de referência foi obtido utilizando o procedimento de caráter experimental proposto pelo Método de Gomes. Este traço foi analisado também pelo Método do Empacotamento Compressível, sendo assim, definidos os outros traços com substituições. As amostras foram caracterizadas no estado fresco de acordo com a norma brasileira ABNT NBR 15823/2010, através de: ensaios de espalhamento no cone de Abrans e Anel “J”, de fluidez no funil “V” e habilidade passante na caixa “L” e caixa “U”. Os resultados mostram que os concretos produzidos com SCA possuem boa capacidade de fluidez. No estado endurecido foram verificadas as resistências mecânicas de compressão axial e tração por compressão diametral dos CAAs nas idades de 7, 28, 56 e 91 dias. Os resultados dos ensaios indicam que é possível substituir CP por SCA sem que haja prejuízo às características mecânicas dos CAAs e ainda obter ganhos técnicos e econômicos. O melhor concreto, levando em conta todos os aspectos estudados, foi com 15% de substituição de CP por SCA. / This study aims to evaluate the potential use of rice husk silica (RHS), obtained under controlled burning conditions, such as partial replacement material to the Portland Cement (PC) in the production of self-compacting concrete (SCC). The RHS employed in this study was produced under controlled conditions in a fluidized bed combustion system, resulting in highly amorphous silica and of good quality. We evaluated the results of the rheological behavior of SCC in the fresh state and strength in the hardened state of a reference concrete without the use of RHS and five concrete made from partial substitution 5%, 10%, 15%, 20% and 25% in RHS relative to the amount of concrete mass. In all traces were used 15% of Fly Ash (FA) is added to the mass of the binder material to assist in reducing friction between particles of the aggregates with cement. The trace of the reference concrete was obtained using the experimental procedure proposed by Gomes method. This trait was also analyzed by the method of packaging compressible and based on this method are defined partial strokes with other PC for RHS substitutions. After obtaining the characteristics of the materials and dosages of SCCs, these were featured in the fresh according to the Brazilian standard NBR 15823/2010, as follows: Spreading tests on cone Abrans and "J-ring", pour in "V-Funnel" and passing ability in the "L-box" and "U-box". The results shows that concrete made with RHS have good flow capacity. In the hardened state the mechanical resistances were checked axial compression and tension by diametrical compression of SCCs at the ages of 7, 28, 56 and 91 days. The test results indicate that it is possible to replace PC with RHS without prejudice to the characteristics of SCCs and still get technical and economic gains. The best concrete, taking into account all the points studied, was the one with replacement of 15% of PC for RHS.

Submitted by Cátia Araújo (catia.araujo@unipampa.edu.br) on 2017-01-26T12:08:41Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Caracterização físico-química do caroço de dendê visando futuras aplicações.pdf: 3013379 bytes, checksum: 6881e3fd3a9ca01e3fa557407b5ff1d0 (MD5) / Approved for entry into archive by Cátia Araújo (catia.araujo@unipampa.edu.br) on 2017-01-26T12:09:14Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Caracterização físico-química do caroço de dendê visando futuras aplicações.pdf: 3013379 bytes, checksum: 6881e3fd3a9ca01e3fa557407b5ff1d0 (MD5) / Made available in DSpace on 2017-01-26T12:09:14Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Caracterização físico-química do caroço de dendê visando futuras aplicações.pdf: 3013379 bytes, checksum: 6881e3fd3a9ca01e3fa557407b5ff1d0 (MD5) Previous issue date: 2016-09-16 / Ao longo do tempo, a preocupação da sociedade com o meio ambiente e a demanda por produtos ecologicamente corretos para serem utilizados em diferentes segmentos industriais aumentaram gradativamente. Considerando tal situação, este trabalho objetivou a caracterização do caroço de dendê (endocarpo), visando futuras aplicações, que poderá resultar em um subproduto. As analises se deram a partir de ensaios de termogravimétrica (TGA/DSC), analise físicas (massa especifica e dureza), difração de raio-x, infravermelho com transformada de Fourier, espectroscopia Raman e microscopia eletrônica de varredura. O caroço de dendê apresentou boa estabilidade térmica, tendo suas degradações iniciadas na faixa de 240ºC. O material evidenciou características de materiais amorfos, porem com alguns picos peculiares, identificando a presença predominante de fases especificas do oxido de silício e celulose. Os resultados obtidos de massa especifica e dureza foram avaliados e comparados com resultados publicados de outros encorpados ou materiais semelhantes. Considerando futuras aplicações, verificou-se que o material em estudo possui baixa atividade pozolanica permitindo seu emprego apenas como carga em compósitos a base de cimento Portland, não descartando a possibilidade de aplicação do mesmo em compósitos poliméricos. Todavia, e imprescindível que mais ensaios sejam realizados com investigações mais especificas para o uso do caroço de dendê com matéria-prima. / Throughout the time, the concern of the society to the environment and the demand for ecologically friendly products for use in different industrial segments increased gradually. Considering this situation, this study aimed to characterize the palm’s core, aiming future applications and may result in a byproduct. The analysis (density and hardness), x-ray diffraction, infrared Fourier transform spectroscopy, Raman spectroscopy and scanning electron microscopy. The palm’s core showed good thermal stability, and its degradations initiated at 240ºC range. The material showed characteristic of amorphous materials, but with some peculiar peaks, identifying the predominant presence of specific phases of silicon oxide and cellulose. The results of density and hardness were evaluated and compared with others results published about cores or similar materials. Considering future applications, it was found that the test material has low pozzolanic activity, allowing its use only as filler in composite cement-based Portland, not rejecting the possibility of applying in polymer composites. However, it is essential that more tests are carried out with more specific investigations into the use of palm’s core as raw material.

Submitted by Cátia Araújo (catia.araujo@unipampa.edu.br) on 2017-01-26T12:21:32Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Analise numérica e experimental da fratura em materiais quase frágeis.pdf: 6564317 bytes, checksum: 0170494c4f4ae0ff6e64f917d9bd4d0a (MD5) / Approved for entry into archive by Cátia Araújo (catia.araujo@unipampa.edu.br) on 2017-01-26T12:21:51Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Analise numérica e experimental da fratura em materiais quase frágeis.pdf: 6564317 bytes, checksum: 0170494c4f4ae0ff6e64f917d9bd4d0a (MD5) / Made available in DSpace on 2017-01-26T12:21:51Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Analise numérica e experimental da fratura em materiais quase frágeis.pdf: 6564317 bytes, checksum: 0170494c4f4ae0ff6e64f917d9bd4d0a (MD5) Previous issue date: 2016-05-09 / Neste trabalho, são realizados estudos experimentais e simulações de ensaios de tração simples para analisar a fratura em materiais quase frágeis. São utilizados três tipos de poliestireno expandido para a confecção de seis modelos de corpos de prova com variações dimensionais. Para evitar a repetitividade, são apresentados e discutidos os resultados experimentais e numéricos obtidos para um tipo de poliestireno expandido, os demais são apresentados no apêndice do trabalho. São analisadas as propriedades mecânicas dos materiais estudados, sendo esses dados posteriormente utilizados nas simulações realizadas através do método dos elementos discretos formados por barras (LDEM). Este método também e utilizado no ambiente do Abaqus para a realização de simulações nas quais uma parte do corpo de prova e modelada em elementos discretos e o restante em elementos finitos. Os ensaios experimentais de tração mostraram que os materiais sofrem um efeito de escala, sendo que os maiores corpos de prova apresentaram uma menor deformação de ruptura. O LDEM utilizado para simular esses ensaios mostrou-se uma boa ferramenta para analisar aa fratura e o efeito de escala em materiais quase frágeis, além disso, sua utilização no ambiente de Abaqus mostrou que os corpos de prova não deformam somente na região central. As simulações no LDEM e no LDEM-Abaqus mostraram que e possível simular somente a região central dos corpos de prova desde que sejam levados em conta os valores de energia elástica. Além disso, através de uma sub-rotina implementada no LDEM foi possível a criação de um mapa de dano da estrutura, possibilitando observar a localização do dano. / In the present work the experimental study and the simulation of simple tensile tests are carried out to analyze the fracture in quasi fragile materials. Three types of expanded polystyrene for the make six models of specimens with dimensional variations are used. However to avoid repetitiveness, is shown and discussed the experimental and numerical results obtained for one type of expanded polystyrene and the results for the other are shown in the appendices. It also analyzed the mechanical properties of the materials studied and the data is subsequently used in the simulations performed by the Lattice Discrete Element Method. It addition, this method is used in Abaqus environment for performing simulations in which part of the specimen is patterned into discrete elements and the remainder in finite elements. The tensile tests showed that the materials suffer a size effect, and the bigger specimens had a shown low rupture strain. The LDEM used to simulate the tests proved to be a good tool to analyze the fracture and size effect on quasi-fragile materials, moreover, their use in Abaqus environment showed that the samples do not strain only in the central region. Simulations in LDEM and LDEM-Abaqus showed that it is possible to simulate only the central region of the specimens provided that are not taken into account the values of elastic energy. Furthermore, by a subroutine implemented in LDEM it was possible to create a structure damage map, allowing observation of the location of the damage.

Submitted by Cátia Araújo (catia.araujo@unipampa.edu.br) on 2017-01-26T11:18:24Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Desenvolvimento de cerâmica refratária com fibra de aço e sílica residual proveniente da queima da casca de arroz.pdf: 5761236 bytes, checksum: a142f60a2f92e30742027abc659f21f3 (MD5) / Approved for entry into archive by Cátia Araújo (catia.araujo@unipampa.edu.br) on 2017-01-26T11:18:41Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Desenvolvimento de cerâmica refratária com fibra de aço e sílica residual proveniente da queima da casca de arroz.pdf: 5761236 bytes, checksum: a142f60a2f92e30742027abc659f21f3 (MD5) / Made available in DSpace on 2017-01-26T11:18:41Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Desenvolvimento de cerâmica refratária com fibra de aço e sílica residual proveniente da queima da casca de arroz.pdf: 5761236 bytes, checksum: a142f60a2f92e30742027abc659f21f3 (MD5) Previous issue date: 2015-02-05 / O Estado do Rio Grande do Sul apresenta um dos maiores índices de produção de arroz do país, e Alegrete é um dos municípios que lidera esta estatística. A casca de arroz é um dos subprodutos originados do beneficiamento do arroz, e é muito utilizada como fonte de energia térmica para a geração de energia elétrica. Após a queima é gerada a cinza da casca do arroz, rica em sílica. Sendo assim, o objetivo deste trabalho é diversificar o aproveitamento deste resíduo como matéria-prima alternativa para materiais cerâmicos refratários e agregar valor a este subproduto. Outro objetivo é aumentar as propriedades mecânicas de matrizes frágeis, que possuem uma tendência a falhar por fadiga e choque térmico, limitando a sua aplicabilidade. Foram fabricados materiais cerâmicos refratários com 80% de argila caulim, 20% de sílica da casca de arroz e fibras de aço em teores volumétricos de 3%, 6% e 9%. Realizaram-se ensaios de absorção de água, densidade aparente, porosidade aparente, resistência à compressão, tração direta, flexão em três pontos, ensaio de choque térmico e análise de microestrutura do material. Com a substituição de argila pela sílica, foram obtidas maior resistência mecânica, e maior tenacidade, possivelmente devido à diminuição da porosidade e pelo aumento do nível de vitrificação. A cerâmica com 9% de fibra obteve o melhor desempenho em relação à ductilidade, em razão do maior grau de deformação do material até o momento de ruptura. As cerâmicas com 3% de fibra e 6% de fibra apresentaram os melhores desempenhos frente ao choque térmico. Na análise da mineralogia do material após a sinterização, observou-se a formação de picos de mulita. Com a substituição da argila pela sílica foram identificados picos de cristobalita. / The State of Rio Grande do Sul presents one of the highest indices of rice production in the Country, and Alegrete is one of the towns that leads this statistics. Rice husk, is one of the byproducts originated from processing of rice, and is very used as thermal energy source to generate electricity. After firing generated rice husk ash, rich in silica. Thus, the aim of this work is to diversify the use of this waste as an alternative raw material for refractory ceramic materials and add value to this byproduct. Another objectiveis to increase the mechanical properties of brittle matrices that have tendency to fail by fatigue and thermal shock, limiting its applicability. Were manufactured refractory ceramic materials with 80% of kaolin clay, 20% rice husk silica, and steel fibers in volumetric concentrations of 3%, 6% and 9%. Tests about water absorption were done, apparent density, apparent porosity, compressive strength, direct traction, three points flexion, thermal shock test and analysis of the microstructure of the material. Replacing the clay by silica, was obtained greater strength, and greater toughness, possibly due to the decrease of the porosity and increasing the level of vitrifying. The ceramic with 9% fiber obtained the better performance relative for ductility, due to the higher degree of deformation of the material until the moment of rupture. The ceramic with 3% fiber and 6% fiber showed better performance front thermal shock. In mineralogical analysis of the material showed the formation of mullite peaks. With substituting the clay by silica cristobalite peak was identified.

Yes / This paper reports the testing of five reinforced concrete continuous beams strengthened in flexure with externally bonded carbon-fibre-reinforced polymer (CFRP) laminates. All beams had the same geometrical dimensions and internal steel reinforcement. The main parameters studied were the position and form of the CFRP laminates. Three of the beams were strengthened using different arrangements of CFRP plate reinforcement, and one was strengthened using CFRP sheets. The performance of the CFRP-strengthened beams was compared with that of an unstrengthened control beam. Peeling failure was the dominant mode of failure for all the strengthened beams tested. The beam strengthened with both top and bottom CFRP plates produced the highest load capacity. It was found that the longitudinal elastic shear stresses at the adhesive/concrete interface calculated at beam failure were close to the limiting value recommended in Concrete Society Technical Report 55.

<p>Solid state Friction stir welding (FSW) is of major interest in the welding of aluminium since it improves the joint properties. Many applications where Al-alloys are used are subject to varying load conditions, making fatigue failure a critical issue. In the scope of this thesis, the fatigue performance of friction stir welded AlMgSi-alloy 6082 has been investigated. Static and dynamic properties of different joint configurations and welds produced with varying process parameters have been determined. Microstructures of fractured surfaces have been studied to evaluate the effect of weld discontinuities on fatigue. The mechanical strength of the friction stir welds was set in relation to that of conventional fusion welds, and that of other FS welded Al-alloys.</p><p>The friction stir process produced aluminium butt welds with high and consistent fatigue strengths, which exceeded the strengths of similar fusion welded samples. A smooth weld geometry showed to be of great importance for the fatigue performance, favouring the friction stir welds. Welding speed in a tested range of 0.35-1.4 m/min had only a modest influence on the properties of the friction stir welds; properties were not deteriorating at the highest speed. The softening of the alloy around the weldline was modelled. A fair description of the hardness profiles across the weld was obtained. At a low and high welding speed a full and partial softening respectively was predicted, indicating that full softening is not required to obtain a flawless weld.</p><p>In case of friction stir overlap welds, tool design is even more important than in butt welding to secure weld quality. A broad tool shoulder with a concave pin end gave the best performance. In particular, the minimal influence on the sheet interface when welding with such a tool was beneficial for the fatigue strength. The stress distribution in overlap and T-type test specimens has been modelled. The stress intensity factors were determined. The corresponding crack propagation rates were in fair accordance with the experimental results. It was found that a simplified approach, developed to estimate ∆K for overlap spot welds, could be used also for friction stir overlap joints.</p>

Submitted by Cátia Araújo (catia.araujo@unipampa.edu.br) on 2017-01-26T11:52:00Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Extração e caracterização da fibra do pecíolo do Butiá Anão (Butia Lallemantii).pdf: 2993911 bytes, checksum: c76c7ef7bd5456adae0483a39ea06bb1 (MD5) / Approved for entry into archive by Cátia Araújo (catia.araujo@unipampa.edu.br) on 2017-01-26T11:52:17Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Extração e caracterização da fibra do pecíolo do Butiá Anão (Butia Lallemantii).pdf: 2993911 bytes, checksum: c76c7ef7bd5456adae0483a39ea06bb1 (MD5) / Made available in DSpace on 2017-01-26T11:52:17Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Extração e caracterização da fibra do pecíolo do Butiá Anão (Butia Lallemantii).pdf: 2993911 bytes, checksum: c76c7ef7bd5456adae0483a39ea06bb1 (MD5) Previous issue date: 2016-05-12 / A utilização de fibras vegetais como material de reforço em compósitos tem despertado interesse de empresas e pesquisadores de diversos ramos de atuação em resposta a preservação e minimização do impactos ambientais, além do desenvolvimento de comunidades locais, aproveitando o potencial de uso das espécies. Entre a grande variedade de fibras vegetais existentes, foi escolhida para ser caracterizada neste trabalho a fibra de Butiá-anão, espécie endêmica da região. O objetivo desta pesquisa foi desenvolver metodologia para obtenção das fibras do pecíolo do Butiá-anão e posterior caracterização das fibras. Inicialmente, os pecíolos do Butiá-anão foram esmagados com auxílio de uma calandra e tratados quimicamente em solução de hidróxido de sódio (NaOH) nas concentrações 2%, 6% e 12% que provocou o amolecimento dos pecíolos, com objetivo de retirar parcialmente a lignina e separar as fibras. Suas caracterizações se deram a partir de análises de termogravimetria (TGA), análise morfológica (teor de umidade, densidade, absorção de água), caracterização química pela determinação de seus principais constituintes (celulose, hemicelulose, lignina, extrativos, teor de cinzas), ensaios de tração e microscopia eletrônica de varredura. As fibras apresentaram boa estabilidade térmica, tendo suas degradações iniciadas na faixa de 250ºC. As fibras se comportaram fragilmente quando submetidas aos testes de tração, observando que a resistência mecânica diminuiu continuamente com a severidade do tratamento. Os resultados obtidos demostraram que os tratamentos químicos proporcionaram a redução de lignina e hemicelulose das fibras. A redução destas frações foi constatada também através de imagens de microscopia que mostraram as superfícies das fibras vegetais. Os resultados obtidos foram avaliados e comparados com resultados publicados de outras fibras vegetais, mostrando que as fibras de Butiá-anão tem potencialidades técnicas para utilização como reforço de compósitos poliméricos. / The use of vegetable fibers as reinforcement material in composites has attracted interest from companies and researchers from different areas of activity in response to preservation and minimization of environmental impacts, and the development of local communities, taking advantage of the potential use of species. Among the wide variety of existing vegetable fibers, was chosen in this work caracterization fiber Butiá-anão, species endemic to the region. The objective of this research was to develop a methodology to obtain the petiole fibers Butiá-anão and further characterization of the fibers. Initially, the petioles of the Butiá-anão were crushed with the aid of a calender and chemically treated with sodium hydroxide (NaOH) solution at concentrations of 2%, 6% and 12% which caused softening of the petioles, in order to partially remove the lignin and separate the fibers. His characterizations are given from thermogravimetric analysis (TGA), morphological analysis (moisture content, density, water absorption), chemical characterization by determination of its major constituents (cellulose, hemicelulose, lignin, extractives ash content) tensile tests and scanning electron microscopy. The fibers showed good thermal stability, and its degradations initiated at 250°C range. The fibers behaved weakly when subjected to tensile testing, noting that the strength continuously decreased with the severity of the treatment. The results demonstrated that chemical treatments resulted in a reduction of lignin and hemicellulose fibers. The reduction of these fractions was also observed by microscopy images showing the surfaces of vegetable fibers. The results wereevaluated and compared with other vegetable fibers published results showing that the Butiá-anão fibers techniques have potential for use as reinforcement of polymeric composites.

O espaço de discussão dos impactos sociais e ambientais das atividades humanas tem ganhado mais relevância nos últimos anos, dentro e fora da Universidade. A engenharia, como área do conhecimento que influencia fortemente o mercado da construção civil, que representa cerca de 10% do PIB nacional, tem uma responsabilidade na criação e fomento de espaços para estudo dessa questão. O Projeto Crescimento, objeto de estudo da pesquisa aqui colocada, tem o propósito de auxiliar nessa discussão, por meio da montagem de uma fábrica protótipo de peças cimentícias em local de alta vulnerabilidade social, com a função de aumentar de qualidade de vida daqueles que participam das atividades na fábrica e das comunidades em seu entorno, por meio do ofício e renda gerados, combinados com um programa de educação que sustenta a mudança em um nível mais profundo. A melhora proposta pode ser medida através de parâmetros objetivos e relatos subjetivos. A iniciativa se baseia na pesquisa em tecnologia de materiais e na produção dos mesmos, combinada com estudos de parâmetros de mercado da construção civil e na economia solidária. A economia solidária, por sua vez, está embasada em novas formas de pensar as relações econômicas e organizá-las no espaço e no tempo, visando uma distribuição do trabalho e seus resultados igualitária e com significado para aqueles que participam da cadeia de dado produto. O produto escolhido para iniciar o projeto foram as peças cimentícias, pela sua facilidade de produção, que pode ser realizada em locais de características variadas, o alto consumo no segmento da construção e a existência prévia de uma tecnologia já desenvolvida dentro do laboratório de microestruturas da Universidade de São Paulo. Além dos objetivos práticos da abertura da fábrica protótipo, a pesquisa se propõe a descrever as diversas maneiras encontradas de tornar o projeto viável, auxiliando na construção de um caminho mais claro para outras iniciativas similares. Dentro do escopo do estudo proposto, também consta o avanço na tecnologia previamente existente, por meio da criação de peças protótipo, foram obtidos os resultados relevantes em termos de desempenho de materiais, comparando-os com normas e requisitos nacionais e internacionais. Assim, foi criado um protótipo funcional de fábrica, com a participação dos moradores de rua da região do Glicério, no centro da cidade de São Paulo. Lá foram testados métodos produtivos, a robustez da fórmula desenvolvida e a inserção social do projeto. A partir da comparação entre os resultados obtidos em campo e em laboratório e das informações extraídas da literatura, espera-se avançar no modelo da economia solidária para eventualmente expandi-lo e aperfeiçoá-lo. / The discussion about the social and environmental impacts of human activity are becoming more relevant each year, inside and outside the scope of University and Industry. Engineering, as a knowledge that greatly influences the construction segment, which represents about 10% of the Brazil\'s GDP, has a responsibility in creating and promoting spaces for the discussion and study of this theme. The objective of the research here-by proposed is to add new information to this discussion by structuring a prototype of an advanced cementitious component factory in high social vulnerability areas, with the purpose of raising the quality of life of those participating in the production and the communities surrounding them, through the craft and pay generated, combined with an educational program, that subsidizes the project at a more profound level. The improvement can be measured with objective parameters and subjective narratives. This initiative is based on the materials research, combined with the study of the construction segment and the solidarity economy. Solidarity economy can be translated by rethinking economic organization and relations in space and time, aimed at a more egalitarian and meaningful distribution of work and its outcomes. The product chosen to start this project are cementitious artifacts, because of the possibility of a modular production, that can be structured in a wide variety of environments, its high consumption in the construction segment and the existence of a well-developed cement material technology, in the microstructure laboratory of the University of São Paulo. Aside from the practical objectives described, this research aims to describe the different ways of making this kind of project viable, there by contributing toward building a clearer path toward similar initiatives. Within the work scope, advancements in the material technology were made, through the production of prototypes, so that relevant data about performance could be obtained and compared with national and international standards. That way, a functioning factory prototype was structured with the collaboration of an organized group of homeless people in the Glicério region in the city center of São Paulo. It was there that the community receptivity, production methods and the cementitious formula\'s robustness were tested. By comparing the results obtained in the field research, in the laboratory, and the academic knowledge on the theme, it is hoped that advancements can be achieved in the materials research and the solidarity economy model.