734 resultados para Guadua angustifolia


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Nowadays, bamboo is being studied because of their strength properties according with their specific mass and speed of growth, which makes it an important alternative as a new resource that will help reduce pressure on forests and helpping them favoring the minimization of uncontrolled deforestation in many regions of Brazil. This study aimed, in general, to analyze physical and mechanical properties of the material with the divulgation of its potential for industrial application. To do so, in this research were determined in relation to the physical properties, moisture content, dimensional stability and the apparent densities and the mechanics and basic, just a tension parallel to grain, in order to observe the interference of various kinds of treatments (chemical, thermal and natural) on the strength and modulus of elasticity in this request. The species used was the Guadua angustifolia, a species native of Brazil. All tests were performed at Universidade Estadual Paulista - Campus Experimental Itapeva in the laboratory of Materials Properties. The methodology used for testing of moisture, density and tension parallel to grain were based on NBR 7190/1997 for the wood, and dimensional stability tests were based on much the same as in COPANT 462/1972 (South American) . The preservative treatments conducted followed the recommendation of each manufacturer. The values obtained in tests of physical properties were satisfactory especially with respect to density and dimensional stability analyzed by the coefficient of anisotropy, showed that, compared to wood, excellent quality for the shrinkage test, obtaining a coefficient of 1.2. With respect to parallel tensile tests to fibre results showed, in most cases, that test specimens with the presence of us have lower values of resistance and modulus of elasticity when compared with those without us. In the treatment of thermal-treatment there was an apparent treatment there was an apparent increase in...

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La Guadua (Guadua angustifolia Kunth) es una de las especies forestales más características de Colombia. Perteneciente a la familia del bambú, ésta planta nativa de Colombia usada en la construcción permite una reducción de costos, garantizados, entre otras ventajas, por sus propiedades físico-mecánicas de flexibilidad, resistencia, dureza, efecto climatizado y sismo resistencia. En el proyecto se plantea inicialmente un estudio de la Guadua como material estructural. Se estudiará su anatomía, sus propiedades físicas y mecánicas así como la normativa existente que rige su uso en construcción y por último se darán algunos ejemplos en los que se puede comprobar su uso en la actualidad. Posteriormente se procederá al desarrollo del proyecto cuya finalidad es el diseño de una estructura modular multifuncional que se necesita para llevarla a cabo en un proyecto de cooperación localizado en Neiva (Colombia). El proyecto incluirá todos los documentos necesarios para un trabajo de estas características: memoria, pliego de condiciones técnicas, presupuesto, planos, así como el Estudio de Seguridad y Salud Laboral. Como solución a las necesidades planteadas en el proyecto de cooperación, se realizará el diseño de dos estructuras modulares cuya finalidad sea las de uso como oficina y como almacén. Se aplicará para su cálculo el CTE cómo normativa de construcción, pero apoyándose en algunos parámetros en la NSR-10, estableciendo una comparativa posterior entre ambas normativas. Debido a la importancia de la acción sísmica en Colombia se comprobará la resistencia sísmica del módulo diseñado según el “Manual de Construcción, evaluación y rehabilitación sismo resistente de viviendas de mampostería” creado por la Asociación Colombiana de Ingeniería Sísmica. Basándose en este manual se definirán los tipos de uniones más favorables sísmicamente de los módulos con el diseño de una cercha auxiliar necesaria según el tipo de unión. ABSTRACT PROJECT: Structural applications of the guadua (Guadua angustifolia Kunth). Project of modular multifunctional structure in Colombia Guadua (Guadua angustifolia Kunth) is one of the forest species more characteristics of Colombia. Pertaining to the family of the bamboo, this one native plant of Colombia used in the construction allows a reduction of costs, guaranteed, among others advantages, by its physic mechanical properties of flexibility, resistance, hardness, climatic effect and earthquake resistance. The project initially considers a study of the Guadua as structural material. We will study its anatomy, its physical and mechanical properties as well as the existing norm that governs its use in construction and finally some examples will be provided in which its actual use can be verified. Later on, we will proceed with the development of the project which purpose is the design of a multifunctional modular structure required to in a project of cooperation located in Neiva (Colombia). The project will include all the necessary documents for a work of these characteristics: memory, technical specifications, budget, drawings, as well as the Security and Labor Health Study. In order to satisfy the needs raised in the cooperation project, we will undertake the design of two modular structures with the purpose to be used as office and warehouse. The construction normative CTE will be applied for its calculation, but some parameters will be based in the NSR-10, establishing a comparison between both norms. Due to the importance of the seismic action in Colombia, the seismic resistance of the module will be verified according to the “Manual of Construction, evaluation and rehabilitation resistant earthquake of rubblework houses” created by the Colombian Association of Seismic Engineering,. We will also use this Manual to define the types of unions more favorable from seismic point of view, designing the required auxiliary segments according to the type of union.

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Se presenta la composición química de los extractos de bambú (Guadua angustifolia). Se realizó un muestreo aleatorio en el Jardín Botánico de la Universidad Tecnológica de Pereira (Colombia) de guaduas maduras y sobremaduras, combinando diafragma, nudo y entrenudo con cepa, basa y sobrebasa, obteniendo un total de 54 muestras. Las muestras se cortaron para obtener discos de unos 2-3 cm de altura, separando nudos, diafragmas y entrenudos. Las muestras trituradas se tamizan y se pesan alícuotas de 3-5 gramos para la extracción. Las extracciones se realizaron por ultrasonidos, con Soxhlet y con extractor Randall con los disolventes éter de petróleo 40-60 C, acetona, metanol y agua secuencialmente. Los extractos se analizaron por cromatografía de gases- espectrometría de masas y HPLC. El contenido total de extractos es del orden del 11,1% en los nudos, 16,5% en los entrenudos y 28,3% en los diafragmas. Entre los compuestos identificados se encuentran esteroles, vitamina E, hidrocarburos saturados, 4 hidroxi- 4 metil- 2 pentanona, neofitadieno, vitamina E, fenoles, aldehidos, los ácidos palmítico y linoleico y dietilenglicol.

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Bamboo has been studied because of its peculiar mechanical properties and numerous possibilities of use, besides being a fast-growing grass and short cutting cycle. This study aimed to analyze the mechanical characteristics of wood-bamboo composite material, where the samples were developed from the combination of layers of bamboo as a structural reinforcement in solid pieces of pine and EGP panel parts. The species of wood used was Pinus taeda, and the bamboo species Guadua angustifolia and Dendrocalamus giganteus. All work was conducted at the Universidade Estadual Paulista - UNESP in the laboratory of Physical and Mechanical Properties of Wood. Tests including the density and tension parallel to grain of the bamboo species used and the static bending of composites in order to use this in the furniture industry. For the tests have been used as a basis the requirements of the normative document NBR 7190/97. The values obtained in the tests showed a significant increase in strength and stiffness compared to unreinforced parts, where there was an increase in MOE and MOR in static bending in all specimens used in evidence. The results showed the possibility of reducing sections in furniture components and the possibility of improving the mechanical properties of parts with defects found in wood of Pinus Itapeva region of São Paulo

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Phytochemical investigation of Kadsura angustifolia led to the isolation and identification of 26 lignans and two triterpenoids, including I I new lignans named kadangustins A-K (1-11). The structures and stereochemistry of 1-11 were elucidated by. analys

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Os projetos com espécies nativas dependem da disponibilidade de sementes e mudas nas quantidades requeridas e com a qualidade apropriada. O mercado, contudo, não oferece sementes de inúmeras espécies, e para a maioria inexistem estudos visando conhecer a distribuição espacial dos genótipos nas populações naturais, informação indispensável para formação de lotes de sementes com qualidade genética, entre as quais o vassourão-branco (Piptocarpha angustifolia Dúsen ex Malme). O vassourão-branco é comum nas clareiras, capoeirões e no estrato secundário da Floresta com Araucária. Além das aptidões madeireiras e para recuperação ambiental, apresenta potencial para compor sistemas silvipastoris. O objetivo deste trabalho foi quantificar a diversidade genética intra e inter-populacional. As árvores amostradas de vassourão-branco, das quais foram coletadas folhas para extração do DNA genômico, estão localizadas em fragmentos florestais em Curitiba e São José dos Pinhais, PR, e Rio Negrinho, SC. Para extração do DNA genômico, foram utilizadas duas folhas com tecido jovem, pesando aproximadamente dois gramas, que foram maceradas em almofariz após adição de nitrogênio líquido. A extração do DNA genômico das folhas do vassourão-branco foi eficiente com qualidade e nas quantidades requeridas para execução da metodologia da PCR-RAPD. As diversidades genéticas entre as populações de Rio Negrinho, e Curitiba e entre São José dos Pinhais, e Rio Negrinho, foi moderada, contudo, entre Curitiba e São José dos Pinhais foi grande. A correlação entre a distância geográfica e dissimilaridade genética entre as populações foi baixa. Não houve correlação entre a distância física e a similaridade genética entre as árvores amostradas nas três populações. A maior parte da diversidade genética encontra-se dentro das populações.

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35 hojas : ilustraciones, fotografías.