Дисертації з теми "Bamboo materials"
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Dixon, Patrick G. (Patrick Gary). "The structure and mechanical behavior of bamboo and bamboo products." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111242.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 199-215).
Bamboo is a unique lignocellulosic material with considerable potential in sustainable construction. Structural bamboo products are analogous to wood products, such as oriented strand board (OSB), but composed primarily of bamboo elements, as opposed to wood elements. Such products could extend the use of bamboo. The mechanical behavior of structural bamboo products in large part depends on that of bamboo tissue. In this thesis, the structure and mechanical properties of dry bamboo tissue are related. Cellular level models are developed and explored, with a focus on density. Density is a practical parameter: it corresponds to weight, and places bamboo in the broader context of cellular solids. Bamboo tissue is made up of parenchyma and vascular bundles, consisting of sclerenchyma fibers and vessels; the structure can be thought of as a fiber reinforced composite. There is a radial gradient in the volume fraction of vascular bundles as well as the fraction of quite solid sclerenchyma fibers within the vascular bundles, increasing from the inside to the outside of the culm wall. Longitudinal flexural properties (modulus of elasticity MOE and modulus of rupture MOR) and compressive strength increase with increasing sclerenchyma fiber volume fraction, indicating the mechanical importance of these fibers. The density also increases with increasing fiber volume fraction. Thus, these longitudinal mechanical properties increase with density. This suggests that in bamboo tissue density reflects the underlying sclerenchyma fiber volume fraction. For moso bamboo (Phyllostachys pubescens), the extrapolated cell wall longitudinal Young's modulus estimate from tests on small flexural specimens, 39.8 GPa, agrees well with the value of 36.6 GPa obtained from a simple cell wall model for the fibers. From mechanical tests of 3D printed models of bamboo parenchyma, an open-cell foam model seems appropriate for bamboo parenchyma. The densification of bamboo increases the longitudinal flexural properties, but natural bamboo at the same density of densified bamboo has higher properties. A multiscale model for wood OSB is adapted for bamboo OSB based on the natural tissue's structure and properties; this model gives a good description of the modulus of elasticity of bamboo OSB made with internode strands.
by Patrick G. Dixon.
Ph. D.
Aijazi, Arfa N. (Arfa Nawal). "Material characterization of Guadua bamboo and the environmental feasibility of structural bamboo products." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/80899.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (p. 52-55).
Bamboo has long been used in vernacular construction because of its high strength, rapid growth rate, and global abundance. Bamboo is increasingly being used in contemporary architecture as a sustainable alternative to wood and other building materials. Forming bamboo into a structural composite can improve mechanical performance, durability, and joining, which can open up new structural applications and design possibilities as well as remove the stigma that bamboo is the "poor man's timber". This study aims to characterize the radial and longitudinal variation in the microstructure and mechanical properties of Guadua bamboo (Guadua angustifolia kunth) in order to inform efficient material use in a composite. The study found a linear relationship between the MOE, MOR, and compression strength with density. Through analysis of micrographs, the density was correlated to the area fraction of sclerenchyma fiber sheaths. Results from nanoindentation confirmed that the fiber properties did not vary with position. Further the environmental impact in the form of exhaustion of energy found that processed bamboo had a mechanical advantage over raw bamboo culm and lower energy input in manufacturing but superior performance in comparison to wood composites.
by Arfa N. Aijazi.
S.B.
Dagilis, Trevor David. "Bamboo composite materials for low-cost housing." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0015/NQ54407.pdf.
Ahmad, Mansur. "Analysis of Calcutta bamboo for structural composite materials." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/28742.
Ph. D.
Gerhardt, Michael R. "Microstructure and mechanical properties of bamboo in compression." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/76122.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 34).
Bamboo has received much interest recently as a construction material due to its strength, rapid growth, and abundance in developing nations such as China, India, and Brazil. The main obstacle to the widespread use of bamboo as a structural material is the lack of adequate information on the mechanical properties of bamboo. In this work, the microstructure and mechanical properties of Phyllostachis dulcis bamboo are studied to help produce a model for the mechanical properties of bamboo. Specifically, a linear relationship is established between the density of bamboo samples, which is known to vary radially, and their strength in compression. Nanoindentation of vascular bundles in various positions in bamboo samples revealed that the Young's modulus and hardness of the bundles vary in the radial direction but not around the circumference. The compressive strength of bamboo samples was found to vary from 40 to 95 MPa, while nanoindentation results show the Young's modulus of vascular bundles ranges from 15 to 18 GPa and the hardness ranges from 380 to 530 MPa.
by Michael R. Gerhardt.
S.B.
Ross, Sheila. "Bamboo construction as a sustainable building technology from a structural and materials engineering perspective." Master's thesis, Faculty of Engineering and the Built Environment, 2021. http://hdl.handle.net/11427/33901.
García, Lina M. (Lina Mariá García De la Ossa). "Radial and longitudinal variation of the mechanical properties of bamboo." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/101858.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 47-48).
Although used for millennia, only recently has there been an increased interest in bamboo as a construction material for its economic, social and environmental benefits. For bamboo to be widely implemented in construction, however, there is a need to better understand the variation in the plant's mechanical properties. The microstructure of bamboo and the mechanical properties of the solid cell wall material of bamboo were characterized for use in models for the variation of the overall mechanical properties of bamboo as a function of radial and longitudinal position. The density of bamboo and the volume fraction of vascular bundles in the bamboo increases with radial position (away from the center of the culm) and decreases with height. Tensile tests follow the trends predicted by the models. Young's modulus and strength increase with radial position (away from the center of the culm). Values for Young's modulus were in the range of 5 to 40 GPa and values for strength varied from 100 to 400 MPa.
by Lina M. Garcia.
S.B.
Qian, Jun. "Investigation of crystallization of poly(3-hydroxybutyrate-CO-3-hydroxyvalerates) and their bamboo fiber reinforced composites." Online access for everyone, 2006. http://www.dissertations.wsu.edu/Thesis/Fall2006/J_Qian_120906.pdf.
Archila, Santos Hector Fabio. "Thermo-hydro-mechanically modified cross-laminated Guadua-bamboo panels." Thesis, University of Bath, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.675700.
Srikar, V. T. (Vengallatore Thattai) 1972. "Electromigration behavior and reliability of bamboo Al(Cu) interconnects for integrated circuits." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/85249.
Ellison, Rachel (Rachel M. ). "Mode II fracture mechanics of moso bamboo for application in novel engineering materials." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98653.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 32-34).
Bamboo has been used as a structural material for thousands of years. Recently there has been increasing interest in its use as a modem construction material. In this study, as part of a larger project to characterize the mechanical properties of Moso bamboo for application in the production of structural bamboo products (SBP), end-notched flexure (ENF) tests and three-point bending tests were performed to obtain the mode II interlaminar toughness (GIIc) and longitudinal Young's modulus (EL). It was found that known values for GIIc, include the pith (innermost layer) and cortex (outermost layer) of the bamboo culm in their calculations. The resulting value is, to a statistically significant degree (t = 5.0 x 10⁶), higher than that with the pith and cortex removed, as they typically will be in processing SBP. A new value, GIIc, = 630 +/- 155 J/m² , was established for specimens lacking the pith and cortex. Although no correlation was found between GIIc, and specimen density, it is suspected that a relationship does exist, and recommendations for further investigation are given.
by Rachel Ellison.
S.B.
Gough, Katherine. "From bamboo to bricks : self-help housing and the materials industry in urban Colombia." Thesis, University College London (University of London), 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416491.
Gu, Xingxing. "Environmentally-benign, Porous and Conductive Carbon Materials for Lithium-Sulphur Batteries." Thesis, Griffith University, 2017. http://hdl.handle.net/10072/366860.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
Full Text
Chan, Cameron D. "MECHANICAL OPTIMIZATION AND BUCKLING ANALYSIS OF BIO-COMPOSITES." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/877.
Matsuoka, Jéssica Harue. "Avaliação da eficiência do ácido pirolenhoso no tratamento preservativo de taliscas de bambu gigante contra a deterioração por fungos." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256852.
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
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Resumo: O bambu apresenta inúmeras características que o qualificam como um material versátil e que há milhares de anos vem servindo como matéria-prima para diversos fins, fazendo parte da história e da cultura de muitos povos. Muitas pesquisas vêm sendo realizadas acerca da utilização do bambu em setores diversos como da construção civil, movelaria e produção de celulose, visando à promoção de um desenvolvimento mais sustentável. Por se tratar de um recurso renovável, o uso do bambu tem o potencial de minimizar os impactos negativos ao meio ambiente e reduzir os custos da produção, além de apresentar excelentes propriedades físico-mecânicas. Dentre as espécies cultivadas no Brasil, o bambu gigante (Dendrocalamus giganteus Munro), de origem asiática, destaca-se na utilização para construção civil, em aplicações estruturais, arquitetônicas e em movelaria. No entanto, a baixa resistência natural da maioria das espécies ao ataque de organismos xilófagos é ainda uma das principais limitações ao seu uso, implicando em graves prejuízos econômicos. Por este motivo, muitos tratamentos preservativos vêm sendo desenvolvidos, com o intuito de prolongar a vida útil do bambu e aumentar sua resistência contra os agentes deterioradores. Este trabalho teve como objetivo identificar os principais gêneros de fungos deterioradores de bambu e desenvolver um método de tratamento preservativo que fosse eficiente no controle da deterioração do bambu por fungos e que minimizasse as características negativas inerentes aos tratamentos químicos ora existentes e ao impacto ambiental por eles causado. Desta forma, investigou-se a possibilidade de utilização do ácido pirolenhoso, produto obtido a partir do processo de carbonização de matéria vegetal. Foram testadas diversas concentrações e tempos de tratamento e realizados ensaios de apodrecimento acelerado em laboratório e ensaios não destrutivos e destrutivos para verificação da eficiência no controle à degradação por fungos. Os gêneros de fungos foram previamente isolados e identificados em ensaios de simulação de exposição em campo. Pela análise estatística dos resultados não houve diferença significativa entre os corpos-de-prova tratados e não tratados. Devido ao limitado período de 16 semanas de duração do ensaio, não foi possível avaliar a ação protetora do ácido pirolenhoso, nas concentrações e tempos de imersão utilizados, quanto à sua eficiência no tratamento preservativo das taliscas de bambu gigante contra deterioração por fungos
Abstract: Bamboo can be considered as a versatile material because of its many features and so it has been used for thousands of years serving as raw material to numerous uses, being part of many people's history and culture. Many researches have been conducted about bamboo uses in several areas, such as construction, furniture making and cellulose production, with the objective to promote a sustainable development, in which bamboo can substitute the conventional materials, especially wood. As bamboo is a renewable resource, it can reduce the negative impact to environment, minimize costs and also presents excellent physical and mechanical properties. There are many cultivated species in Brazil, such as the giant bamboo (Dendrocalamus giganteus Munro), an Asian specie that is largely used on construction, in structural and architectural applications and to furniture production. However, most species of bamboo has low natural resistance to the wood decay organisms, which still constitutes one of the major limitations to its use and can cause several economic damages. For this reason, many preservative treatments have been developing, aiming to increase bamboo life cycle and its resistance against decay agents. This work had as objective to identify the main genera of wood decaying fungi and develop an efficient preservative treatment method that controls fungal bamboo decay and minimize the negative features intrinsic to existing chemical treatment and the environmental impact caused by them as well. It was investigated the possibility of using a pyroligneous acid, which is obtained from the vegetal coal production process. Several concentrations and time of treatment were tested and specimens were submitted to an accelerated decay test in laboratory and non-destructive and destructive tests to verify the product efficiency against fungi decay. Fungi genera were previously isolated and identified through a test that simulated field exposure. The statistical analysis from the results indicated no significant difference between treated and non-treated specimens, however, due to the short period of 16 week of the essay, it wasn't possible to evaluate the protective activity of pyroligneous acid, for the concentrations and times of treatment applied to the strips, about its efficiency on preservative treatment against bamboo fungi decay
Mestrado
Construções Rurais e Ambiencia
Mestre em Engenharia Agrícola
Ballesté, Joan Font. "Desempenho construtivo de estruturas de cobertura com colmos de bambu." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/16/16132/tde-21122017-103248/.
The focus of this research is the study of the performance of bamboo in coverage structures. The architecture of the 21st century needs new production models and new materials to enable the sustainable development of the planet. Bamboo is a renewable material, with low production costs, positive ecological footprint and excellent physical-mechanical properties; but there is a rather general lack of knowledge about its use in civil construction. This gap is even greater when one tries to understand its structural behaviour over time. Among the various requirements to evaluate the performance of the material, when it is the structural element in a construction, two that stand out are essential: stability and durability. In this work, the understanding of the physical and mechanical behaviour of the material in the microscopic and macroscopic composition is sought first to delimit its structural safety, and secondly, examining the processes that, since the plants\'s growth until its usage in work, determine the useful life of the material. It is also analyzed the constructive practices and project actions that condition transversally these two performance requirements, along with a survey of case studies that aim to create new criteria of structure design and building solutions. This research seeks to export the strengths and weaknesses of the current construction with bamboo, so the first may be potentialized and the latter corrected.
Miskalo, Eugênio Polistchuk. "Avaliação do potencial de utilização de bambu (Dendrocalamus giganteus) na produção de painéis de partículas orientadas." Universidade Tecnológica Federal do Paraná, 2009. http://repositorio.utfpr.edu.br/jspui/handle/1/182.
The consumption of restored wood boards has increased, bringing along the use of woods derived from reforestation, traditionally from Pinus and Eucalyptus, composed of long and short fibers respectively, which demand the enlargement and replacement of the plantation areas quickly. In this essay, the main objective was to measure the potential application of the bamboo as an alternative to make boards of Oriented Strand Board – OSB. The kind of bamboo studied was the Dendrocalamus giganteus, which is made of medium strands. Boards were produced with 4, 6 and 8% contents of phenol-formaldehyde resin. The experimental work was divided in two stages. The purpose of the first stage was to study the variation of density and the relative highness of the bamboo studied, in order to separate particles with different characteristics, and proceed the selection of the stem part with density more similar to the one indicated by MALONEY, with the purpose of making boards with similar characteristics to Pinus OSB boards, using the same production technique. On the second stage, experimental planning was applied to obtain bamboo boards of particles with two slit orientation and three numbers of adhesive. The physical and mechanical tests were performed according to the European patterns EN 300/93 and American patterns ASTM 1037-1996. The results indicated that the boards made in bamboo at the tangential direction at 6% of resin is the most appropriate to produce on a large scale, considering that its yield and mechanical behavior is comparable to commercial OSB, in agreement to quoted patterns.
Knowlton, Brett D. (Brett Douglas). "The effects of grain structure and Cu distribution on the relability of near-bamboo Al-Cu alloy interconnects." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/10379.
ADNAN, ALI MUHAMMAD, and SARWAR MUHAMMAD IMRAN. "Sustainable and Environmental freindly fibers in Textile Fashion (A Study of Organic Cotton and Bamboo Fibers)." Thesis, Högskolan i Borås, Institutionen Textilhögskolan, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-20137.
Program: Magisterutbildning i Applied Textile Management
Barros, Andréa Carla de Almeida. "Estudos Sobre o Potencial do Bambu Guadua angustifolia Kunz. Para a Fitorremediação dos Metais Pesados Zinco e Cádmio." Universidade Federal de Alagoas, 2007. http://repositorio.ufal.br/handle/riufal/1067.
Fundação de Amparo a Pesquisa do Estado de Alagoas
A fitorremediação é considerada uma tecnologia economicamente promissora e ecologicamente correta porque utiliza processos físico-químicos e bioquímicos naturais para a limpeza de áreas degradadas. A Guadua angustifolia (Bambusoideae, Poacea), um bambu nativo da América do Sul e Central, que apresenta colmos robustos, altos e espinhosos, apresenta considerável potencial para a fitorremediação de metais tóxicos pelas seguintes razões: a) possui extraordinária capacidade de multiplicação e reprodução vegetativa; b) pode resgatar CO2 da atmosfera eficientemente, contribuindo para a diminuição do chamado 'efeito estufa'; c) não faz parte da cadeia alimentar; d) possui atributos ornamentais que podem ser utilizados no paisagismo de áreas poluídas, como aquelas previamente ocupadas pelos lixões; e) a biomassa aérea pode ser aproveitada na construção civil ou na indústria moveleira, após cumprido o papel fitoextrator. O objetivo do presente estudo foi investigar o potencial da G. angustifolia para a fitorremediação dos metais pesados zinco e cádmio. Os processos de absorção e translocação dos metais das raízes para as partes aéreas e sua distribuição nos diferentes tecidos foram analisados. Além disso, a produção de proteínas transportadoras de metal (fitoquelatinas) e a formação de complexos de metal com compostos orgânicos de baixo peso molecular foram investigados. Os experimentos com G. angustifolia foram conduzidos tanto em condições hidropônicas, quanto no solo. O solo artificialmente contaminado com soluções de sulfato de zinco ou cádmio foi distribuído em saquinhos de plástico perfurados. As mudas de bambu, previamente mantidas em vermiculita, foram transplantadas para o solo contaminado e conservadas na casa de vegetação, à temperatura ambiente, durante 180 dias, com regas periódicas. As plantas foram então lavadas e dessecadas à temperatura ambiente e as amostras de raízes, colmos, folhas e solo foram digeridas com uma mistura de ácido nítrico e ácido perclórico (3:1; v/v) durante 3 h à temperatura ambiente e posteriormente por 3 a 4 h à 120 °C. A determinação da concentração de zinco e cádmio nas diferentes amostras foi realizada através de espectroscopia de absorção atômica a 213,9 e 228,8 nm respectivamente. Com base nos valores médios absolutos da concentração, os fatores de bioconcentração (FBC) e de translocação (FT) foram calculados. O acúmulo de zinco e cádmio nas plantas cultivadas no solo obedeceram à ordem raízes > colmos > folhas. O acúmulo de zinco nas raízes do bambu foi de 57,2% (2720 mg/kg peso seco), enquanto que v nas partes aéreas foi de 42,8% (2032 mg/kg peso seco). O acúmulo de cádmio nas raízes foi de 79,9% (770 mg/kg) e nas partes aéreas foi de 20,1% (194 mg/kg). As análises demonstraram que ocorreu uma redução de 65,5% na concentração de zinco e 60,2% na concentração de cádmio, no solo contaminado, após o cultivo com bambu. No que diz respeito ao zinco, os altos valores de FBC (> 1) indicaram que as raízes e os tecidos aéreos ainda não haviam sido saturados e/ou os sistemas de transporte ainda estavam ativos nas condições experimentais empregadas e uma quantidade ainda maior de metal poderia ser absorvida e transportada. Com relação ao cádmio, os valores de FBC indicaram que ainda não havia ocorrido saturação e/ou a inativação dos sistemas de transporte nas raízes, ao contrário dos tecidos aéreos que já se encontravam saturados. Os valores de FT para ambos os metais foram baixos (< 1) indicando que o sistema de transporte de zinco e cádmio nos tecidos da G. angustifolia não são muito eficientes. Assim, a G. angustifolia atende um dos um dos critérios usados para definir plantas hiperacumuladoras, em que a concentração de zinco nas partes aéreas das plantas desenvolvidas em substrato contaminado foi aproximadamente 20.2 vezes maior do que o valor médio encontrado em plantas desenvolvidas em solos não poluídos, enquanto que a concentração de cádmio foi 194 vezes maior. Outras análises mostraram que a concentração de zinco no solo contaminado, que havia sido cultivado com bambu, foi reduzida em 65,5%, enquanto que o nível de cádmio foi reduzido em 60,2%. Um dos maiores obstáculos ao emprego da G. angustifolia para a fitorremediação desses metais parece estar relacionado com a translocação nos tecidos, principalmente dos colmos para as folhas. Embora esses aspectos limitam a aplicação da G. angustifolia na fitorremediação do zinco e cádmio, podemos afirmar que essa espécie apresenta grande potencial, visto que a maior parte da biomassa da planta é representada pelos colmos. Esse potencial poderia ser explorado através do uso de técnicas agronômicas adequadas para viabilizar o crescimento das plantas em solos poluídos e de técnicas de engenharia genética para facilitar a mobilidade dos metais das raízes para as folhas.
Lopez, Jay. "Optimizing the Mechanical Characteristics of Bamboo to Improve the Flexural Behavior for Biocomposite Structural Application." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/902.
Ostapiv, Fabiano [UNESP]. "Resistência mecânica do material compósito: madeira de eucalipto-lâmina de bambu." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/103757.
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Tanto o bambu como o eucalipto são importantes recursos florestais. As lâminas de bambu gigante, contínuas, largas e finas obtidas por processo de torneamento são um excelente material para revestir e reforçar madeira e painéis sarrafeados de eucalipto. Neste trabalho foram realizados ensaios de cisalhamento e tração normal na madeira de eucalipto de alta densidade com e sem o revestimento com lâminas de bambu. Foram produzidos painéis sarrafeados colados lateralmente (EGPs) de Eucalyptus saligna que foram ensaiados à flexão estática e a tração normal, segundo a norma NP EN 310, no sentido transversal do painel em que as ripas são coladas lateralmente. Verificou-se que as lâminas de bambu funcionaram como reforço mecânico para os casos de tração normal na madeira de eucalipto, mas que não houve reforço quando sujeita a esforços cisalhantes, independentemente da posição dos anéis de crescimento da madeira nas amostras. Neste caso as lâminas funcionaram apenas como revestimento. Verificou-se um comportamento frágil do painel sarrafeado de eucalipto durante sua ruptura a flexão no sentido transversal. Foram repetidos os ensaios para os painéis sarrafeados de eucalipto revestidos com lâminas de bambu gigante em dupla face. Verificou-se então um grande aumento na resistência mecânica à flexão estática no painel laminado. Com o reforço das lâminas houve uma mudança no comportamento do painel que deixou de romper de forma frágil passando a romper de modo dúctil, tornando o painel mais elástico e confiável ao uso. Além disso, foram estudadas as características de acabamento superficial das lâminas de bambu quando o material é submetido a processos de lixamento manual
Both bamboo and eucalyptus wood are important forest resources. The giant bamboo veneers continuous, wide and thin obtained by turning process are an excellent material for cover and reinforce the wood and laths edged glued panels (EGP) of Eucalyptus saligna. In this work was tested the eucalyptus wood of high density to shear and normal traction, then the eucaliptus wood was covered with layers of bamboo veneer and so repeated the same mechanic tests. Were produced panels EGP of eucalyptus that were tested for static bending, according to NP EN 310, in the direction that the laths are glued. It was found that bamboo veneers acted as mechanical reinforcement for the cases of normal traction in the eucalyptus wood, but there was no increase in eucalyptus wood subjected to shear efforts, regardless of the position of growth rings in wood samples. In this case the veneers functioned only as a coating. There was a fragile behavior of the panel EGP of eucalyptus during their break to shear efforts. The tests were repeated for the panels EGP coated with bamboo venners on double-sided. There was then a large increase in mechanical resistance to bending of laminated panel. With the increase obtained was a change in behavior of the panel that failed through the fragile break so ductile rupture, making the panel more elastic and reliable to use. Furthermore were studied the characteristics of roughness of the surface of bamboo veneer when the material is subjected to manual sanding processes
Guimarães, Ricardo José. "Avaliação do uso de bambu como estrutura em alvenaria de blocos de solo-cimento." Universidade Tecnológica Federal do Paraná, 2017. http://repositorio.utfpr.edu.br/jspui/handle/1/2705.
The use of materials that involve less energy in the production process, are more easily absorbed by nature and generate less pollutants and waste is of great interest for the future of the planet and its inhabitants. This paper presents themes of sustainability for civil construction, such as the potentialities and technical feasibility of an emerging material in Brazil, bamboo, which fits perfectly in the question, since it is an element that has good engineering properties and with great availability in rural areas. In addition to this, soil-cement blocks, so well used in today's buildings, also intended for sustainable buildings, are part of the research. In an experiment that sought to unite the academic teaching with practice, a prototype of wall in blocks of soil-cement structured with bamboo sticks was developed. The main elements of the research were the evaluation of the strengths of the compression-conditioned soilcement blocks, of bamboo to axial compression and bending, and of the combination of soil-cement / bamboo blocks. Results of 153 kN were obtained for the walls and 7.45 MPa for the soil cement blocks in the compression tests. In the bamboo compression tests, the obtained values resulted in 119.09 MPa and 96.21 MPa for test bodies with and without nodes, respectively. The results obtained in the tests developed with the materials separately and also from the set showed that both perfectly fit the one proposed in this work, which allows to consider adequate the methodology used in the preparation of the test bodies as well as in the execution of the related tests.
Ostapiv, Fabiano. "Resistência mecânica do material compósito : madeira de eucalipto-lâmina de bambu /." Guaratinguetá : [s.n.], 2011. http://hdl.handle.net/11449/103757.
Banca: Manoel Cléber de Sampaio Alves
Banca: Marcos Valério Ribeiro
Banca: Eduardo Mauro do Nascimento
Banca: Ivaldo de Domênico Valarelli
Resumo: Tanto o bambu como o eucalipto são importantes recursos florestais. As lâminas de bambu gigante, contínuas, largas e finas obtidas por processo de torneamento são um excelente material para revestir e reforçar madeira e painéis sarrafeados de eucalipto. Neste trabalho foram realizados ensaios de cisalhamento e tração normal na madeira de eucalipto de alta densidade com e sem o revestimento com lâminas de bambu. Foram produzidos painéis sarrafeados colados lateralmente (EGPs) de Eucalyptus saligna que foram ensaiados à flexão estática e a tração normal, segundo a norma NP EN 310, no sentido transversal do painel em que as ripas são coladas lateralmente. Verificou-se que as lâminas de bambu funcionaram como reforço mecânico para os casos de tração normal na madeira de eucalipto, mas que não houve reforço quando sujeita a esforços cisalhantes, independentemente da posição dos anéis de crescimento da madeira nas amostras. Neste caso as lâminas funcionaram apenas como revestimento. Verificou-se um comportamento frágil do painel sarrafeado de eucalipto durante sua ruptura a flexão no sentido transversal. Foram repetidos os ensaios para os painéis sarrafeados de eucalipto revestidos com lâminas de bambu gigante em dupla face. Verificou-se então um grande aumento na resistência mecânica à flexão estática no painel laminado. Com o reforço das lâminas houve uma mudança no comportamento do painel que deixou de romper de forma frágil passando a romper de modo dúctil, tornando o painel mais elástico e confiável ao uso. Além disso, foram estudadas as características de acabamento superficial das lâminas de bambu quando o material é submetido a processos de lixamento manual
Abstract: Both bamboo and eucalyptus wood are important forest resources. The giant bamboo veneers continuous, wide and thin obtained by turning process are an excellent material for cover and reinforce the wood and laths edged glued panels (EGP) of Eucalyptus saligna. In this work was tested the eucalyptus wood of high density to shear and normal traction, then the eucaliptus wood was covered with layers of bamboo veneer and so repeated the same mechanic tests. Were produced panels EGP of eucalyptus that were tested for static bending, according to NP EN 310, in the direction that the laths are glued. It was found that bamboo veneers acted as mechanical reinforcement for the cases of normal traction in the eucalyptus wood, but there was no increase in eucalyptus wood subjected to shear efforts, regardless of the position of growth rings in wood samples. In this case the veneers functioned only as a coating. There was a fragile behavior of the panel EGP of eucalyptus during their break to shear efforts. The tests were repeated for the panels EGP coated with bamboo venners on double-sided. There was then a large increase in mechanical resistance to bending of laminated panel. With the increase obtained was a change in behavior of the panel that failed through the fragile break so ductile rupture, making the panel more elastic and reliable to use. Furthermore were studied the characteristics of roughness of the surface of bamboo veneer when the material is subjected to manual sanding processes
Doutor
Radaik, Carlos Eduardo. "Cadeia produtiva do bambu como material construtivo e sua aplicação: estudos de caso no estado de São Paulo." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/102/102131/tde-31082018-150821/.
The focus of this research is the study of the bamboo productive chain as constructive material, investigating agents, activities and its processes. The architecture of the future needs new models and constructive materials to enable the sustainable development of the planet. The actual housing demand in Brazil and in the world, require from the civil construction sector a larger consumption of raw material and therefore producing a larger emission of CO2 and energy consumption. New materials that demand a smaller amount of energy and its production and a smaller residual generator are beginning to occupy a prominent position in the productive chain of the civil construction. In this context, the bamboo in natura shape is included in the construction materials of the future, because its physical-mechanical component, also environmental, economic and social component that could contribute in a positive manner. Architects and constructors, in Brazil and in other parts of the world, have considerably increased the use of bamboo; using it in residences, warehouses and even in large structures, although there is a widespread ignorance about its use in the civil construction. This gap is even larger when one seeks to understand its productive chain. The comprehension of its agents, processes and the use of non-conventional materials, such as bamboo, for a project conception is fundamental for the student and the professional development, whether an engineer or architect. The fieldwork, along with the theoretical referential studied, allowed the comprehension of the bamboo productive chain as a constructive material, besides to not follow the established standard in the literature, mainly with the relationship between agents and its processes involved directly in the transformation of the raw material, it presents in a unorganized and frail form, with a concentration of processes within few agents, resulting in little efficiency and hindering its development.
Palombini, Felipe Luis. "Design de estrutura biônica através de prototipagem e análise por elementos finitos baseada em microtomografia do bambu." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/153296.
Bamboo is considered one of the natural materials with the best strength-to-weight ratio. Among the features responsible for its properties are the sclerenchyma’s fiber bundles that protect the conducting elements of water and solutes in the plant, and are filled by parenchyma. Bamboo fibers are gradually distributed from the inner to the outer side of the plant, thus increasing the culm stiffness. However, the morphology of the section of the fiber bundles and the presence of the parenchymatic matrix in the stem have not been fully studied regarding its structural importance, neither applied in bionic structures. This study addresses the design of bionic structures based on the characterization of bamboo, by means of non-invasive techniques, rapid prototyping and finite element analysis. A bamboo sample (Bambusa tuldoides Munro) was col-lected and softening and drying protocols were followed for proper sectioning. The surface of the sample was analyzed by high-resolution X-ray microcomputed tomog-raphy. Resulting images allowed the segmentation of the sample’s constituent tissues and the characterization at a cellular level. The 3D models of the parenchyma and sclerenchyma were discretized for a non-linear finite element analysis. The results showed that the parenchyma is set as a low-density cellular matrix by distributing the stresses among all reinforcement elements in the plant, being considered a tissue with great structural importance. Likewise, the shape of the fiber bundles’ section showed superior mechanical performance compared to reference sections. Both characteris-tics were applied in the development of two bionic structures that were analyzed as more efficient than a literature model, and 3D printed for a visual analysis.
Mary, Wellington. "Ambiencia para morangueiro, em hidroponia, para a produção na entressafra e bambu como elemento construtivo para casa de vegetação." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257222.
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola
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Resumo: O uso da tecnologia do cultivo protegido e hidroponia no Brasil para a produção de hortaliças e plantas ornamentais passou por diversas fases de adaptação, visando sempre a atender às necessidades de oferta e qualidade dos produtos com a preocupação de se minimizar os custos de produção e os efeitos negativos do clima. A grande maioria destas adaptações partiu da iniciativa dos próprios agricultores, utilizando-se de diferentes materiais e outros artifícios para contornar problemas do seu dia-a-dia. Com os objetivos de analisar o sistema construtivo de estrutura de bambu para utilização em casa de vegetação e testar diferentes sistemas de controle ambiental, visando à produção na entressafra do morangueiro. Foram realizados cinco experimentos na área do campo experimental da Faculdade de Engenharia Agrícola/UNICAMP, no período compreendido entre Fevereiro de 2002 e Janeiro de 2004.No primeiro experimento testou-se o uso de vigas e colunas construídas com de colmos de bambu da espécie Bambusa tuldoides Munro. As vigas e colunas foram estruturadas com espaçadores de plástico, especificamente desenhados para facilitar e padronizar a construção, conferindo-lhe maior resistência e estabilidade. Foram avaliados três espaçamentos entre colunas (2,0; 2,5 e 3,0m) sob diferentes esforços de carga, dos quais o melhor resultado foi obtido com o espaçamento de 2,5m. Nos outros experimentos o objetivo foi estudar o controle ambiental aplicado ao cultivo do morangueiro para produção na entressafra no Estado de São Paulo, cultivado em sistema NFT e aeroponia sem e com zona de resfriamento. Foram avaliados: massa fresca de cada pseudofruto/planta e massa total de pseudofrutos/planta, número de pseudofrutos e de estolhos/planta. Utilizou-se as cultivares: Campinas; Sweet Charlie; Seascape; Oso Grande e Tudla. Também foi analisado o microclima gerado pelos sistemas aeropônicos A produtividade dos sistemas aeropônicos sem e com resfriamento foi inexpressiva, porém influenciaram sobre a temperatura da solução nutritiva e do microclima dentro das bancadas. Os tratamentos envolvendo o controle de fotoperíodo e vernalização promoveram a produção durante o período de entressafra
Abstract: The use of the hydroponic technology and the Brazilian horticulture and ornamental plants had many different phases of adaptation and always looking for the necessity to offer and the quality of the production with the concern to minimise the production cost. Also to at the negative effects of the climate. The majority of these adaptations start with the farmers and they used different materials to fix their day to day problems. With the objective to analyse the constructive system of the bamboo structure for use in the vegetation house and to test different environmental control systems with the aim to look at the production between the harvest of the strawberry plants. In the period between February 2002 and January 2004 five experiments of this type were carried out at the experimental station at the College of Agricultural/Unicamp Engineering. In the first experiment they tested the use of beams and columns of colmos of Bambusa tuldoides Munro species of bamboo. The beams and columns had been structured with plastic spacers specifically made to standardize the construction, due to greater resistance and stability. Three spaces between columns (2,0, 2,5 and 3,0m) under different load efforts had been evaluated, and the best result was obtained with the spacing of 2,5m. In the other experiments the objective was to study the ambient temperature control applied to the culture of the strawberry plants for production in the period between harvests in the state of São Paulo, cultivated in NFT system and aeroponics with and without and a cooling zone. They had evaluated cool and total mass of fruit/plant, the number of fruits and stolon/plant. The varieties used had been: Campinas; Sweet Charlie; Seascape; Oso Grande and Tudla. The microclimate generated for the aeropônico system with cooling zone was also analyzed. The treatments involving the control of photoperiod had promoted the production during the period of period between harvests. Despite the aeroponics systems with and without cooling, produced during the period between harvests, the productivity was good, however they had influenced inside on the temperature of the nutritional solution and the microclimate of the different plant groups
Doutorado
Construções Rurais e Ambiencia
Doutor em Engenharia Agrícola
Sweeney, Benjamin Andrew. "The Effect of Biocomposite Material In A Composite Structure Under Compression Loading." DigitalCommons@CalPoly, 2017. https://digitalcommons.calpoly.edu/theses/1932.
Andrade, Molina Vanessa Mishell. "Bambú en la construcción análisis de diferentes casos de estudio con sistemas constructivos en bambú." Master's thesis, Universidade de Évora, 2019. http://hdl.handle.net/10174/26322.
Nogueira, Cláudia de Lima. "Ciência do material bambu e tecnologia de sua aplicação em vigas laminadas coladas de seção transversal composta." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-19042013-100149/.
In this study it was evaluated the bamboo strength in the stages before and after mechanical processing in order to obtain basic references to study the mechanical properties of simple glued laminated beams of composite section and composed section as I joist, manufactured in laboratory scale. It started with the characterization of raw material as strip representing the crude bamboo culm wall, moved to the processed material as in the shape of laminas which were representing the majority of bamboo culm wall industrially useful and culminating to the manufacture and qualification of glued laminated beams. In the production of specimens of raw material it was maintained the original thickness for the strip except for a few ones which were produced to evaluate the radial shear strength in the inner and outer layers of the culm wall. The strips were machined on some machines to be turned into laminas that were the units for assembling composite sections by agglutination and adhesion under pressure in environmental conditions. It was also studied the node influence in the radial and tangential shear strength in both solid material and in the adhesive plan and in properties got from the bending tests. The geometry and dimensions of the shear specimens were adapted from ASTM D 905 and the bending from NBR 7190. Shear strength in the adhesive plane and bending property were determined following three combinations of contact faces on the gluing process using resorcinol-formaldehyde based adhesive. It was studied also the proper pressure for gluing the specimens and elect the most suitable for glued laminated beams. The intact specimens and failed on mechanical tests were observed under a Scanning Electron Microscope, Optical Microscope, Optical fluorescence microscope and stereomicroscope. It was observed huge variation of mechanical properties in both solid and composite materials, but in all cases there was considerable variability of strength data and in general the material without node was more resistant than with node. The ruptures mechanisms occurred most often in the parenchyma tissue by passing the fiber bundles and tend to follow the grain of the material by observing the rupture plane that only coincides with the plan designed to rupture when the specimen is done with precise consideration of grain orientation. The specimens manufactured with PVA adhesive and components with nodes responded satisfactorily to the low pressure bonding, while the specimens produced with internodes components performed better at high pressure. For specimens manufactured with resorcinol-formaldehyde adhesive the best gluing combination was given by the contact of outer laminas surfaces to each other. It was possible to observe the anchorage of the adhesive into the anatomical tissues by using optical microscopy and fluorescence optical microscopy. Glued laminated beams with composite cross section were tested in bending, but not failed by normal stresses, once there occurred only lateral instability during loading time. The I beams also showed low modulus of elasticity because the crush in the inferior flange was added by the measurement system to the bending deflection. In general the mechanical quality of the \"I\" joist can be considered very high with correct calculation of the moment of inertia of composite cross sections. The layers perpendicular to the beam axis both in web and in the flanges, were so efficient in absorbing the shear that there was no limitation of carrying load web-frange connection even with the beam working in a critical influence of high shear stresses.
Huang, Puxi. "Hygrothermal performance of Moso bamboo-based building material." Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.715306.
Kassa, Bewketu Z. "Bamboo: An Alternative Building Material for Urban Ethiopia." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/66.
He, Qian. "Étude sur le mécanisme d'activation du bois/bambou/adhésif et amélioration du collage induit par le champ électrique à haute tension." Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0147.
In this study, the advanced equipments were selected in order to investigate the effects of HVEF on the physicochemical properties of wood and bamboo, the effects of HVEF on the chemical structure and rheological properties of adhesives under a series of HVEF parameters. The aggregation effect of adhesive at bonding interface induced by HVEF has also been revealed and the micro-mechanical prediction model is established.The main conclusions of this study are as follows:1.After HVEF treatment, the surface activity of wood and bamboo increased significantly. Moreover, with the increase of voltage/time, the surface free radicals, O/C ratio and the number of oxygen groups increased significantly while the contact angle decreased. Under the condition of 60kV, the surface activity highly increased. The increment of free radicals was 26%, the decrease of initial contact angle was 22%, the decrease of equilibrium contact angle was 23%, the increment of free energy component was 43% ~ 75%, the increment of O/C ratio was 34%, the increment of oxygen-containing groups were 39% (C‒OH), 149% (C‒O or C=O) and 97% (O‒C=O), respectively. Therefore, under HVEF treatment, the physical and chemical properties of wood and bamboo can be significantly improved, which is conducive to improving the interphase properties of composite materials.2.With the increase of voltage/time, significantly improved inter-molecular reactions of urea formaldehyde resin and phenol formaldehyde resin were obtained. After 60kV/8 min treatment, significant increment of the characteristic peaks of C‒O groups were obtained. Under HVEF treatment, the temperature/frequency dependence of the rheological behaviors of the two resins changed significantly. Therefore, the degree of inter-molecular polymerization of phenol formaldehyde and urea formaldehyde resin can be significantly improved and the viscoelasticity of the resin can be improved under HVEF treatment.3.After HVEF treatment, the distribution of adhesive at the bonding interphase was continuous and uniform. The penetration depth was significantly reduced. The density and bonding strength at the bonding interphase were significantly increased, and the delamination rate was reduced. After treatment, the maximal density at interphase is 1081 kg/m3, which was 32% higher than the control. The bonding strength increased from 0.66MPa to 1.25MPa and the wood breaking rate increased to 85%, and the delamination rate decreased to 5.97%. For bamboo material, the bonding strength was significantly improved after HVEF treatment. The bonding strength of bamboo skin and bamboo skin was 9.51MPa, and the bamboo failure ratio was 60%. In the combination of bamboo pith and bamboo pith, the maximum bamboo failure ratio was 85%, which was increased by 70%. Therefore, under HVEF treatment, the continuous and uniform distribution of bonding interphase adhesives can be obtained, which can significantly improve the bonding performance of wood bamboo composite, and is conducive to the efficient utilization of wood bamboo composite.4. According to the vertical density profile at the bonding interface, the laminated stiffness and stress distribution model of the bonding interface has been established. The results showed that the relative error was less than ±15%. Based on the distribution model, the macroscopic mechanical properties of composite are predicted with the combination of composite mechanics and laminated plate theory, including elastic modulus, bending strength, shear modulus and shear strength. The results showed that the prediction error of mechanical properties is less than 30%. With the stiffness and strength distribution model, the effect of HVEF treatment can be quantitatively characterized and the mechanical properties of HVEF treated composites can be predicted. As a result, strengthening mechanism of bonding interphase can be revealed with the the stiffness and strength distribution model
Ferreira, Gisleiva Cristina dos Santos 1975. "Vigas de concreto armadas com taliscas de bambu Dendrocalamus Giganteus." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258260.
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
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Resumo: A utilização do bambu como elemento estrutural vem sendo estudada há dezenas de anos, apresentando excelentes resultados em relação às suas características físicas e mecânicas. Assim, alguns pesquisadores iniciaram nas últimas décadas estudos para viabilizar a aplicação do bambu como armadura em elementos de concreto. Neste sentido, este trabalho pretende apresentar soluções ao principal problema de utilização do bambu como armadura em elementos estruturais de concreto, um modelo de dimensionamento eficaz, determinado os Estados limites últimos e de utilização. Para tanto, escolheu-se a espécie de bambu Dendrocalamus giganteus (Gigante) devido suas dimensões e fácil obtenção em todo território do Brasil. Os colmos de bambu foram divididos em taliscas com seção transversal de 2 x 1 cm (largura x espessura). Em seguida, realizaram-se ensaios de caracterização física e mecânica, de acordo com procedimentos existentes na literatura e propostos neste trabalho. A partir dos resultados destes ensaios e dados propostos por FERREIRA (2002), foi realizado o dimensionamento teórico seguindo os procedimentos da NBR 6118 (2003). Para tanto, foi considerado o Estádio II, considerando-se como Estado limite último a deformação última do bambu igual a 2,0 ¿ e o encurtamento último do concreto igual a 3,5 ¿. Já para o Estado limite de utilização, foi determinada a força cortante máxima e o deslocamento vertical máximo. Foram confeccionadas 6 vigas com armadura longitudinal de taliscas de bambu retas e dobradas sem tratamento para melhorar a aderência. Os resultados indicaram possibilidades na utilização de taliscas de bambu como armadura em vigas de concreto, havendo a necessidade dos cálculos serem realizados conforme o Estádio II. A utilização da armadura de bambu dobrada proporcionou uma melhor distribuição das fissuras e conseqüentemente, uma melhor ancoragem da armadura
Abstract: The use of bamboo as a structural element has been studied for some years, presenting excellent results relating to its physical and mechanical characteristics. Therefore, some researches began in last decade¿s studies to apply bamboo as reinforcement in concrete elements. In this sense, this work has intended to present solutions to most common problem in the application of bamboo in structural concrete elements: an efficient calculus procedure, obtaining the limit states. Thus, it was chosen de Dendrocalamus giganteus specie because it¿s easy to find this specimen in Brazil and because of its dimensions. The bamboo caulis were cut in strips with 2 x1 cm cross section. Then it was realized physical and mechanical characterization tests, in accordance to literature proceedings ant methods proposed in this work. From this tests results and according to FERREIRA (2002), it was conducted the theorical calculus respecting NBR 6118 (2003). It was considered second state, determining as an ultimate limit state the ultimate deformation of the bamboo equal to 2,0¿. For the service limit state it was determined the maximum vertical displacement. It was constructed six beams with longitudinal reinforcement of bamboo strips without adherence treatment and without stirrups. Three of this beams had its strips bent. The results indicate the possibilities in the use of bamboo strips as reinforcement of concrete beams, following second state. The use of bent strips provided a better distribution of the cracks and consequently a better anchorage of the reinforcement
Doutorado
Arquitetura e Construção
Doutor em Engenharia Civil
RAMBO, CARLOS R. "Sintese e caracterizacao de ceramicas biomorficas." reponame:Repositório Institucional do IPEN, 2001. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10973.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
Holmström, Emelie. "Bambusa vulgaris as a roof material : A field study about bamboo age, treatment and the possibility to build with bamboo in Ghana." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-128814.
Silva, Rodolfo Gomes da. "Tratamento de bambu com ácido pirolenhoso contra a deterioração por brocas." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256862.
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
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Resumo: A concentração da população mundial em grandes centros urbanos gera uma imensa demanda por madeira, o que tem levado à devastação das florestas tropicais, causando a extinção de várias espécies. O bambu é uma alternativa à madeira convencionalmente utilizada na movelaria, na construção, na produção de energia, na fabricação de papel e celulose e em outras atividades industriais. Apesar das numerosas vantagens econômicas e ambientais do bambu, seu uso esbarra na limitada durabilidade natural da maioria das espécies. A deterioração do bambu, causada por agentes físicos, químicos e biológicos, faz com que esse vegetal seja considerado um material de baixa qualidade, criando a falsa ideia de que o bambu somente deveria ser usado quando da falta de materiais mais apropriados para determinados fins. Os principais agentes deterioradores do bambu são os fungos e os insetos, dentre os quais se destaca a broca do bambu. A proteção do bambu pode ser feita por meio do uso de diversos produtos dentre os quais se destaca o ácido pirolenhoso, obtido a partir da pirólise de madeira e de outros materiais vegetais. No presente trabalho, buscou-se avaliar a eficácia do tratamento aplicado a taliscas de bambu por cozimento em ácido pirolenhoso em três diferentes diluições (10, 20 e 30%) durante cinco intervalos de tempo (15, 30, 60, 120 e 180 minutos), buscandose a sua proteção contra a deterioração pela broca do bambu, avaliando-se o dano nas taliscas de bambu através das variações na massa e na velocidade do pulso ultrassônico (VPU) através dessas taliscas. Os experimentos de deterioração foram realizados durante 20 semanas. Os dados foram sujeitos a testes de correlação e interações entre as variáveis. O teste T pareado indicou haver diferença significativa entre as medidas de VPU e massa no início e depois de 20 semanas de ensaio. Em média, a VPU diminuiu e a massa aumentou, resultado este influenciado pela variação de umidade no período. Buscou-se, ainda, determinar a porcentagem de fibras em relação aos outros tecidos por meio de análise de imagens de cortes transversais dos corpos de prova. Por fim, buscou-se estabelecer um método eficiente de criação de Dinoderus minutus para ensaios de deterioração do bambu
Abstract: The concentration of worldwide population in large urban centers creates huge demand for timber, which can lead to devastation of the rainforest, resulting in the extinction of several species. Bamboo is an alternative to wood commonly used on furniture, building, power generation, pulp and paper and other industrial purposes. Despite its many economic and environmental advantages, the bamboo utilization is hampered by the low natural durability of most species. The bamboo deterioration by physical, chemical and biological agents, makes it to be considered a low quality material, creating the misconception that it should only be used in the abscence of appropriate materials for certain purposes. The major spoilage agents on the bamboo are the fungi and insects, among which stands out the powder-post beetle. The bamboo protection can be done through the use of various protective agents such as the pyroligneous acid, obtained by pyrolysis of wood and other plant materials. This study aimed to evaluate the efficacy of the treatment applied to bamboo splits cooked in pyroligneous acid at three different solutions (10, 20 and 30%) over five time intervals (15, 30, 60, 120 and 180 minutes) searching for the protection against the deterioration of the powder-post beetle by measuring the variation of the mass and the ultrasonic pulse velocity (UPV) across the strips. The deterioration assays were performed during 20 weeks. The data were subjected to correlation and interaction between variables tests. The two-sample pooled t-test indicated significant differences between the measures of UPV and mass at starting and after 20 weeks testing. On average, the UPV decreased and increased mass, a result influenced by the increasing relative moisture. The study also aimed to determine the fiber content by image analysis of transverse sections of the bamboo splits. Finally, the study sought to establish an efficient method of creating Dinoderus minutus for bamboo deterioration tests
Mestrado
Construções Rurais e Ambiencia
Mestre em Engenharia Agrícola
Nunes, Antônio Ricardo Sampaio. "Construindo com a natureza bambu : uma alternativa de ecodesenvolvimento." Universidade Federal de Sergipe, 2005. https://ri.ufs.br/handle/riufs/4337.
Este trabalho teve como objetivo investigar as possibilidades de aplicação do bambu como um material de construção em Sergipe, analisando-se os aspectos decorrentes do processo de uso, quais sejam: eficiência econômica, propriedades físicas e mecânicas do material, desempenho da mão de obra local, níveis de aceitação do material pela população usuária, desempenho estético do bambu na arquitetura e suas possibilidades de ecodesenvolvimento. O método empregado para esta investigação foi o da pesquisa-ação que utilizou uma ação coletiva planejada de caráter técnico, social e cultural, orientada em função da resolução de problemas conceituais e técnicos operacionais, levantados nas questões de pesquisa. A ação escolhida para se proceder a investigação que levaria a responder tais questões foi a construção de uma edificação cujo material aplicado seria prioritariamente o bambu. O local escolhido para construção foi o Horto do Diogo, situado na fazenda Oiteirinhos de propriedade da Petrobrás, no município de Carmópolis, estado de Sergipe, Brasil. Foi sob a perspectiva do ecodesenvolvimento que propomos investigar o uso do bambu como uma alternativa para o desenvolvimento com sustentabilidade ambiental contextualizando-o num processo tecnológico, social, econômico e cultural. O ecodesenvolvimento é o fundamento para o entendimento da ecotécnica como uma estratégia para superar as barreiras impostas pela economia de mercado dominante. Para o seu sucesso toma-se fundamental o desenvolvimento de tecnologias apropriadas que absorvam o melhor da diversidade tanto humana como natural de cada ecossistema (local ou regional) de forma particular. O bambu se revela como uma planta e um material de grandes potencialidades, sendo comprovadas nesta pesquisa, as suas propriedades físicas e mecânicas que o qualifica como um material de fácil uso por populações rurais ou periféricas de pequenas cidades, se afirmando como uma alternativa de desenvolvimento comunitário sustentável e ecodesenvolvimento.
Ramirez-Quintero, Deyber Alexander 1985. "Influência da granulometria do material inerte e da composição de misturas binárias contendo areia e partículas de bambu (in natura e carvão produto do processo pirolítico) sobre a fluidodinâmica de leitos fluidizados." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265823.
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: A aplicação de biomassas em processos de geração de energia como a combustão, pirólise e gaseificação, operando com a tecnologia de leito fluidizado, tem merecido atenção crescente nas últimas décadas. Esses sistemas necessitam da adição de partículas de material inerte que ajudam a promover uma fluidização estável, permitindo a melhoria da eficiência de tais processos. Dentre as biomassas com potencial para geração de energia sustentável está o bambu, material que apresenta propriedades semelhantes às de outras biomassas utilizadas em processos de geração de energia, com a vantagem de apresentar rápido crescimento, fácil propagação, regeneração vigorosa, maturidade rápida. O objetivo deste projeto foi estudar o comportamento fluidodinâmico de misturas de partículas de areia e bambu (in natura e na forma de carvão proveniente de processo de pirólise) visando à obtenção de parâmetros inerentes à fluidização dessas misturas, bem como analisar o efeito da degradação térmica da partícula de bambu sobre a fluidização do leito. A análise foi realizada a partir do levantamento experimental da curva fluidodinâmica em sistema de leito fluidizado operando a frio, com diferentes composições das misturas bambu-areia e carvão-areia. Adicionalmente foi verificada a influência do tamanho das partículas de areia e da altura estática do leito sobre a fluidodinâmica do leito. Os resultados mostraram que a melhor qualidade da fluidização do leito contendo partículas de bambu in natura foi obtida usando a areia identificada como areia 3 (diâmetro médio de 460 µm), relação entre a altura estática do leito e o diâmetro do leito igual à unidade (H/D = 1) e máximo teor de biomassa no leito igual a 5% (em massa). No entanto, esse tamanho areia não forneceu boas condições de fluidização para a mistura carvão-areia. A utilização da Umf do material inerte para o projeto de reatores de pirólise, utilizando partículas de bambu como combustível, não é recomendável, uma vez que a presença de apenas 5 % (em massa) de bambu in natura aumenta o valor da Umf em 20 %, enquanto que esse aumento é de 10 % no leito contendo carvão de bambu. Espera-se que os resultados obtidos neste estudo forneçam dados úteis para o projeto de reatores que utilizam a tecnologia de leito fluidizado. Pretende-se também contribuir para o entendimento da fluidodinâmica de sistemas que utilizam misturas de biomassas e areia para geração de energia
Abstract: The use of biomass in power generation processes such as combustion, pyrolysis and gasification, operating with the fluidized bed technology, has received increasing attention in recent decades. These systems require the addition of inert particles to promote a stable fluidization, allowing the improvement of process efficiency. Among the biomasses with potential for sustainable power generation is bamboo, which presents similar properties to other biomasses used in energy generation processes, with the advantage of rapid growth, easy propagation, vigorous regeneration and quick maturity. In addition, its properties allow the recovery of environmentally degraded areas. The objective of this research was to study the hydrodynamics behavior of fluidized beds composed by mixtures of sand and bamboo particles (in natura and in the form of coal from pyrolysis process). Parameters inherent to fluidization of these mixtures, as well as the effect of thermal degradation on the fluidization process of bamboo particles are analysed. The analysis was performed from hydrodynamics curves obtained in an experimental system operating at room temperature, with different compositions of bamboo in nature and bio-char in the bed. Additionally, the influences of sand particle size and static bed height on the fluidized bed hydrodynamics were verified. Results showed that the best quality of fluidization of the studied mixtures was achieved using sand particles 460 ?m diameter (sand 3), static bed height and column diameter ratio equal to unity (H/D = 1) and maximum weight fraction of bamboo in the bed equal to 5%. However, this size of sand particles did not provide a good quality of fluidization for coal-sand mixture. The Umf of the inert material is not recommended to be used in the design of pyrolysis reactors as the addition of 5 wt% of bamboo in natura in the bed causes an increment of 20 % on Umf while this increment is 10 % for the bed containing bamboo char. Results obtained from this study could provide useful data for the design of fluidized bed reactors that operate with bamboo particles. It is also intended to contribute on understanding the hydrodynamics behavior of fluidized beds using mixtures of biomass and sand for power generation
Mestrado
Termica e Fluidos
Mestre em Engenharia Mecânica
Oliver, Borrachero Bernardo Antonio. "Estudio de la utilización de fibras naturales en materiales compuestos laminados para fabricación de componentes de automoción." Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/165809.
[CA] L'evolució de la tendència del pensament de la gent als últims anys ha canviat, portant-nos a adquirir nous valors enfocats a la sostenibilitat dels recursos naturals i al respecte cap al medi ambient. A causa d'això, la perspectiva de producte s'ha vist afectada en tots els sectors, inclòs al sector de l'automoció. L'aparició de noves normes mediambientals han establit obligacions sobre els fabricants de vehicles respecte a la reducció de consum i emissions contaminants pel que cada vegada és més habitual identificar materials lleugers en vehicles d'ús quotidià amb la finalitat de millorar l'eficiència energètica a partir de la reducció de massa. El present estudi pretén avançar un pas més en la utilització de materials compostos centrant la seua temàtica en el desenvolupament de nous materials per a la fabricació de components de vehicles que permeten la reducció de consums des d'un punt de vista sostenible. Per a això es planteja l'aplicabilitat de nous materials compostos basats en la utilització de fibres naturals, que substituïsquen els materials emprats tradicionalment. En l'estudi es planteja la utilització d'una única matriu (epoxi) comú a tots els teixits naturals assajats que permeta realitzar un estudi comparatiu centrat en els teixits per obtindre un material compost eficient en la seua fabricació, ús i reciclatge, buscant l'equilibri entre densitat, cost, resistència i reciclabilitat. L'estudi ha consistit en la realització d'assajos de tracció, compressió, flexió, impacte, duresa, tallant i fatiga, a partir dels quals s'han pogut extraure les propietats mecàniques necessàries per a realitzar un model MEF uniaxial al programa ANSYS ACP, comparant resultats amb diferents orientacions de fibres. Després d'això, s'ha dimensionat un component utilitzant el model MEF uniaxial per a un estudi multiaxial. Aquest component s'ha fabricat i posteriorment s'ha assajat en un banc de fatiga amb la finalitat de contrastar els resultats del programa amb els obtinguts empíricament, i alhora ha servit per validar l'aplicació.
[EN] The evolution of the trend of people's thinking in recent years has changed, leading us to acquire new values focused on the sustainability of natural resources and respect for the environment. As a result, the product outlook has been affected in all sectors, including the automotive. The imposition of new environmental regulations has established obligations for vehicle manufacturers in terms of fuel consumption and polluting emissions, which is why it is increasingly common to identify lightweight materials in everyday vehicles, in order to improve energy efficiency through from mass reduction. This study seeks to advance the use of composite materials, focusing its theme on the development of new materials for the manufacture of structural vehicle components. For this, it is proposed the development of new composite materials based on the use of natural fibers is proposed to replace the materials traditionally used. In the work is proposed a comparative study focused on fabrics, using a single matrix (epoxy) common to all the test specimens, to obtain an efficient composite material in its manufacture, use and recycling, seeking the balance between density, cost, resistance and recyclability. During the development of the research, it has been necessary to perform tensile, compression, bending, impact, hardness, shear and fatigue tests to extract the mechanical properties necessary to make a uniaxial MEF model in the ANSYS ACP software, comparing results with different orientations fibers. After this, a component has been dimensioned using the uniaxial FEM model for a multiaxial study. This component has been manufactured and subsequently tested in a fatigue bench in order to compare the results of the software with those obtained empirically, and in turn validate the application.
Oliver Borrachero, BA. (2021). Estudio de la utilización de fibras naturales en materiales compuestos laminados para fabricación de componentes de automoción [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/165809
TESIS
Sánchez, Vivas Lorena. "Bamboo as a Sustainable Engineering Material: Mechanical Properties, Safety Factors, and Experimental Testing." Scholar Commons, 2019. https://scholarcommons.usf.edu/etd/7925.
Moraes, Maria Júlia Bassan de. "Estudo do potencial da cinza de folha de bambu para sua utilização como material pozolânico e sustentável em matrizes cimentantes /." Ilha Solteira, 2019. http://hdl.handle.net/11449/180946.
Resumo: O contexto mundial de preocupação em relação ao meio-ambiente, seu uso desenfreado e a emissão dos gases estufa, principalmente a emissão de dióxido de carbono destacou a importância da pesquisa para se buscar novas alternativas sustentáveis nos meios de produção, dentre eles se encaixa a indústria do cimento Portland. A proposta deste estudo é uma nova alternativa sustentável para a construção civil, estudando a cinza de folha de bambu (CFB) como material pozolânico para ser utilizado como substituição parcial do cimento Portland. A cinza de folha de bambu foi produzida através de um processo de autocombustão sem temperatura controlada, e foi caracterizada física e quimicamente através dos ensaios de Fluorescência de Raio – X (FRX), determinação do teor de sílica amorfa, Difratometria de Raio – X (DRX), Granulometria a Laser, Microscopia Eletrônica de Varredura por Emissão de Campo (FESEM), Espectroscopia de Infravermelho por Transformada de Fourier (FTIR) e Analise Termogravimétrica (TGA). Sua reatividade foi analisada através dos ensaios de condutividade elétrica e pH, ensaio de Frattini e pastas de Cal/CFB e Cimento/CFB, as quais foram submetidas aos ensaios de FTIR, TGA e FESEM. Para avaliar sua influência na argamassa no estado fresco e endurecido, foram realizados os ensaios de índice de consistência e o ensaio de resistência à compressão, comparando-se as argamassas com substituição parcial do cimento à uma argamassa controle, sem adição mineral. Já a influência da ci... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The global context of concern for the environment, its unrestrained use and emission of greenhouse gases, especially the emission of carbon dioxide, highlighted the importance of research to find new sustainable alternatives in the means of production, among them, the Portland cement industry. The proposal of this study is a new sustainable alternative for civil construction, studying bamboo leaf ash (BLA) as pozzolanic material to be used as partial replacement of Portland cement. The bamboo leaf ash was produced by a process of autocombustion without temperature control, and was characterized physically and chemically by means of X - Ray Fluorescence (FRX), determination of the amorphous silica content, X - Ray Diffractometry (XRD), Laser Granulometry, Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). The reactivity analysis was carried out by means of electrical conductivity and pH measurements, Frattini analysis and calcium hydroxide / CFB and Cement / CFB pastes, which were assessed by FTIR, TGA and FESEM analysis. In order to evaluate its influence on the mortar in the fresh and hardened states, the tests of consistency index and compressive strength were carried out, comparing mortars with cement partial replacement with a control mortar, without mineral addition. The influence of the ash on durability was analyzed by means of mercury intrusion porosimetry analysis (MIP) and acid ne... (Complete abstract click electronic access below)
Mestre
Juárez, González Diego Alonso. "Uso y rentabilidad del bambú como material estructural de construcción." Bachelor's thesis, Pontificia Universidad Católica del Perú, 2019. http://hdl.handle.net/20.500.12404/15946.
Тининика, Анастасія. "Сучасні тренди предметного дизайну (бамбук: звернення до ремесла)". Thesis, Київський національний університет технологій та дизайну, 2018. https://er.knutd.edu.ua/handle/123456789/10847.
The main characteristics of bamboo products are considered in the context of the cultural synthesis of traditions and innovations in subject design. The examples analyze the use of bamboo as an eco-material when creating articles of subject design.
Tranquilin, Ricardo Luis [UNESP]. "Estudo das propriedades microestruturais e ópticas do BaMoO4 processado em hidrotermal assistido por microondas." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/88504.
O estudo das propriedades fotoluminescentes nos diferentes materiais tanto orgânicos e inorgânicos tem despertado muito o interesse da comunidade científica. Dentre os molibdatos, destacamos o molibdato de bário (BAMoO4) devido suas propriedades ópticas e termoelétricas que junto com suas emissões luminescentes no azul, verde e laranja o tornam um importante material. Neste trabalho, pós de molibdato de bário foram sintetizados pelo método de coprecipitação e processados a 140 ºC por diferentes tempos, em hidrotermal assistido por irradiação de microondas. A caracterização dos pós foi realizada através de difração de raios - X, espectroscopia Raman, absorção na região do infravermelho. As análises microestruturais e morfológicas destes pós foram realizadas através das técnicas de microscopia eletrônica de varredura por canhão de elétrons e microscopia de Transmissão. As propriedades ópticas foram verificadas por meio da espectroscopia na região do ultravioleta visível e medidas de fotoluminescência.
The study of properties in different photoluminescent both organic and inorganic materials has attracted much interest form the scientific community. Among the molybdate,. the highlight of barium molybdate (BaMoO4) because their optical properties and thermoelectric that along with its luminescent emission in blue, green and orange make it an important material. In this work of barium molybdate were synthesized by co-precipitation method and processed at 140 ºC for diferent times in hydrothermal assisted by microwave irradiation. The characterization of powders was carried out by-ray diffraction - X, Raman spectroscopy, absorption in the infrared region. The micro structural and morphological analyses of these powders were performed using the techniques of field emission gun scanning electronic microscopy and by trasmission electronic microscopy. The optical properties were observed by spectroscopy in region the ultraviolet visible and measures of photoluminescence.
Correia, Viviane da Costa. "Produção de celulose nanofibrilada a partir de polpa organossolve de bambu para nanoreforço de compósitos cimentícios." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/74/74133/tde-04092015-104346/.
Low elastic modulus vegetable fibers are known for their ability to increase the energy absorbed by cement based materials while they are loaded, especially during the post-crack stage. The use of cellulose nanofibers may contribute for toughening of brittle matrices and improving particle packing by both pore refining and crack intercepting at nanoscale, with the corresponding energy absorption. Nanofibrillated cellulose comes from a natural, abundant and renewable resources, it has good mechanical peformance and high specific surface, which contributes to improve the adhesion between the cement particles. These factors justify the use of nanofibrillated cellulose and give rise to an alternative nanoreinforcement for cement based materials. Thus, the aim of this work was the production of the nanofibrillated cellulose from bamboo organosolv pulp, establishing the best condition for its production and subsequent use as reinforcement in hybrid composites (both nano and micro-scale reinforcement) compared to composites reinforced with only microfibers (pulp), produced by the slurry vacuum dewatering followed by pressing and extrusion methods. The nanofibrillated cellulose was produced submitting unbleached and bleached pulps to 5, 10, 15 and 20 nanofibrillated cycles by the grinding method. Chemical, physical and mechanical tests were carried out to define the optimal condition to nanofibrillation. The unbleached nanofibrillated cellulose produced by 10 cycles was defined as the best option to be used in hybrid composites, since their greater modulus of elasticity and, because of their greater structural chemical stability, higher resistance to degradation in alkaline environments. The composites were subjected to accelerated carbonation curing process to mitigate thedegradation of fiber by reducing the matrix pH and also to refine the pores. The composites were subjected to accelerated aging process by means of 200 wet and dry cycles to assess their degradation. The hybrid composites and the composites reinforced only with pulp at 28 days and after accelerated aging were subjected to physico-mechanical and microstructural tests to study the effect of the nanofibrillated cellulose on their properties. There was no difference in the physical properties of the hybrid composites and composites reinforced with only pulp, produced by the two processes at 28 days. For the slurry vacuum dewatering followed by pressing process, although useful for adjustments in the formulation and cure hybrid composite, there was no statistically significant contribution of the nanofibrillated cellulose in the formation of stress transfer bridges, and therefore without a corresponding increase in the mechanical strength of the composites. For the extruded composites, the nanofibrillated cellulose improved the mechanical behavior of the hybrid composite compared to the composite without nanofiber. This improvement may be associated with greater adherence between the nanofibrils and the cement matrix, which was confirmed by microstructural analysis (SEM) of the composites. After accelerated aging, the composites with and without nanofibers produced by the two processes showed no reduction in mechanical performance, which is attributed to the lower alkalinity provided by the accelerated carbonation.
Tirocchi, Martina. "Legno e bambù lamellare: materiali ecosostenibili a confronto nel caso studio di un garden office con prestazioni acustiche nella copertura." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/23709/.
Melo, Santino Loruan Silvestre de. "Investigação das propriedades mecânicas e adesão interfacial dos compósitos de polipropileno virgem e reciclado reforçados com fibras e microfibras de bambu." reponame:Repositório Institucional da UFC, 2016. http://www.repositorio.ufc.br/handle/riufc/18446.
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The development of renewable and biodegradable materials is undoubtedly one of the most important of research to reduce environmental impacts. Therefore, the development of materials that can replace the use of materials from fossil fuels with raw material biodegradable, and almost unlimited achievement, makes plant fibers are a promising reinforcement to non-biodegradable materials. In this study, bamboo fibers were used to reinforce composites. In order to improve the fiber / matrix adhesion, chemical modifications were made on the fiber surface. Bamboo microfibers were also found to produce micro-composites and evaluate the mechanical stability of these modified micro-composites, which has the advantage of orientation in all directions of the material. The mechanical properties of mercerized and acetylated fibers and their composites with virgin and recycled polypropylene were obtained to analyze the stress at break and elastic modulus were affected after the surface treatment applied to the fiber. Analyses by SEM revealed the degradation of fibers depending on chemical modification, indicating the phase-matrix adhesion of composites and micro-composites. The FTIR fibers showed the efficacy of mercerization and acetylation surface with the appearance / disappearance of bands in the range of 3300 cm-1-3700 cm-1 and also at 1750 cm-1. With fiber tensile tests, it could be seen as chemical procedures affect the mechanical stability of the fibers. X-ray diffraction (XRD) were used to verify the degree of crystallinity of the fibers and relate it to their final mechanical properties. The crystallinity index with increased NaOH concentration (in mercerising solution) and decreased over time with acetylation. Tensile tests of fibers and composites revealed the influence of chemical modifications on the fibers. When For a higher concentration of NaOH in solution, the fibers had a higher maximum stress at rupture. However, for a longer acetylation was lower maximum stress at rupture of those fibers. For the virgin polypropylene composites uni- and bidirectional caused mechanical reinforcement fibers in some guidelines, such as the one-way 0 °. In all composites with recycled matrix, the fibers have been proven effective in the mechanical reinforcement of composites, reinforcing the maximum stress at break of up to 350% for composites bi-directional fibers. The modification procedure by acetylation in composites was effective as the mechanical reinforcement compared to composites with only mercerized fibers.
O desenvolvimento de materiais renováveis e biodegradáveis é uma das importantes vertentes de pesquisa para a diminuição dos impactos ambientais. Logo, o desenvolvimento de materiais que possam substituir o uso de materiais provenientes de fração destilada do petróleo por matéria prima biodegradável, e de obtenção quase ilimitada, faz com que as fibras de origem vegetal sejam um promissor reforço de para materiais não biodegradáveis. Neste estudo, fibras de bambu foram utilizadas para reforço de compósitos. No intuito de melhorar a adesão fibra/matriz, modificações químicas foram realizadas na superfície da fibra. Microfibras de bambu também foram obtidas para produzir microcompósitos e assim avaliar a estabilidade desses microcompósitos modificados, que possuem a vantagem de orientação em todas as direções do material. As propriedades mecânicas das fibras mercerizadas e acetiladas bem como seus compósitos de polipropileno virgem e reciclado foram obtidas para analisar principalmente a resistência e módulo de elasticidade. Estas propriedades foram afetadas após o tratamento superficial aplicado à fibra, apresentando os efeitos das modificações superficiais das fibras. As análises em MEV revelaram a degradação das fibras vegetais consoante modificação química, indicando a aderência fase-matriz dos compósitos e microcompósitos. Os FTIR’s das fibras revelaram a eficácia do procedimento de mercerização e acetilação superficial com o surgimento/desaparecimento de bandas na faixa de 3300 cm-1 a 3700 cm-1 e também em 1750 cm-1. Com os ensaios de tração das fibras, pôde-se perceber como os procedimentos químicos afetaram a estabilidade mecânica das fibras. As difrações de raios-X (DRX) foram utilizadas para verificar o grau de cristalinidade das fibras e relacioná-lo com as suas propriedades mecânicas finais. Para as fibras mercerizadas, o índice de cristalinidade, proporcionalmente, aumentou com concentração de NaOH (em solução de mercerização) e diminuiu com tempo de acetilação. Os ensaios de tração em fibras e compósitos revelaram a influência das modificações químicas nas fibras. Quando houve maior concentração de NaOH em solução, as fibras apresentaram uma maior resistência, entretanto, para um maior tempo de acetilação, foi menor a tensão máxima na ruptura dessas mesmas fibras. Para o polipropileno virgem, os compósitos uni e bidirecionais provocaram reforço mecânico em algumas orientações de fibras, como nas unidirecionais a 0°. Em todos os compósitos com matriz reciclada, as fibras se mostraram eficazes no reforço mecânico dos compósitos produzidos, reforçando a tensão máxima na ruptura em até 350% para compósitos com fibras bidirecionais. O procedimento de modificação por acetilação nos compósitos foi eficaz quanto ao reforço mecânico comparativamente aos compósitos com fibras apenas mercerizadas.
Tranquilin, Ricardo Luis. "Estudo das propriedades microestruturais e ópticas do BaMoO4 processado em hidrotermal assistido por microondas /." Bauru : [s.n], 2009. http://hdl.handle.net/11449/88504.
Banca: Fenelon Martinho Lima Pontes
Banca: Alberthmeiry Teixeira Figueiredo
- O Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, PosMat, tem caráter institucional e integra as atividades de pesquisa em materiais de diversos campi da Unesp
Resumo: O estudo das propriedades fotoluminescentes nos diferentes materiais tanto orgânicos e inorgânicos tem despertado muito o interesse da comunidade científica. Dentre os molibdatos, destacamos o molibdato de bário (BAMoO4) devido suas propriedades ópticas e termoelétricas que junto com suas emissões luminescentes no azul, verde e laranja o tornam um importante material. Neste trabalho, pós de molibdato de bário foram sintetizados pelo método de coprecipitação e processados a 140 ºC por diferentes tempos, em hidrotermal assistido por irradiação de microondas. A caracterização dos pós foi realizada através de difração de raios - X, espectroscopia Raman, absorção na região do infravermelho. As análises microestruturais e morfológicas destes pós foram realizadas através das técnicas de microscopia eletrônica de varredura por canhão de elétrons e microscopia de Transmissão. As propriedades ópticas foram verificadas por meio da espectroscopia na região do ultravioleta visível e medidas de fotoluminescência.
Abstract: The study of properties in different photoluminescent both organic and inorganic materials has attracted much interest form the scientific community. Among the molybdate,. the highlight of barium molybdate (BaMoO4) because their optical properties and thermoelectric that along with its luminescent emission in blue, green and orange make it an important material. In this work of barium molybdate were synthesized by co-precipitation method and processed at 140 ºC for diferent times in hydrothermal assisted by microwave irradiation. The characterization of powders was carried out by-ray diffraction - X, Raman spectroscopy, absorption in the infrared region. The micro structural and morphological analyses of these powders were performed using the techniques of field emission gun scanning electronic microscopy and by trasmission electronic microscopy. The optical properties were observed by spectroscopy in region the ultraviolet visible and measures of photoluminescence.
Mestre
Cerrón, Oyague Tania Miluska. "Estrategias de arquitectura ecológica con bambú y el confort térmico, en el Parque Nacional del Manu, Cusco." Master's thesis, Universidad Ricardo Palma, 2016. http://cybertesis.urp.edu.pe/handle/urp/1022.