|
|
|
| Registros recuperados: 36 | |
|
|
| Christoforo,André L.; Panzera,Tulio H.; Neto Junior,Carlito Calil; Demarzo,Mauro A.; Ribeiro Filho,Sérgio L. M.; Toniolo,Luiz E.; Amstalden,Rogério A. S.; Lahr,Francisco A. R.. |
| This study aims to present an alternative calculation methodology based on the Least Squares Method for determining the modulus of elasticity in bending wooden beams of structural dimensions. The equations developed require knowledge of three or five points measured in displacements along the piece, allowing greater reliability on the response variable, using the statistical bending test at three points and non-destructively, resulting from imposition of measures from small displacements L/300 and L/200, the largest being stipulated by the Brazilian norm NBR 7190:1997. The woods tested were Angico, Cumaru, Garapa and Jatoba. Besides obtaining the modulus of elasticity through the alternative methodology proposed, these were also obtained employing the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Wood; Beam theory; Modulus of elasticity; Least Squares Method. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162014000100016 |
| |
|
|
| Galván Escobedo, Iris Grisel. |
| El Museo Nacional de las Culturas (MNC) ubicado en el centro histórico de la ciudad de México, es un edificio que fue construido en 1734 sobre los restos de la antigua ciudad de México -Tenochtitlán habitada por los mexicas (1324-1521). En el MNC se realizaron excavaciones arqueológicas con el objeto de recuperar información histórica relacionada con el sitio, tendientes a una restauración integral del edificio y su posterior adecuación museográfica. De los trabajos arqueológicos se derivó esta tesis que tuvo como finalidad recuperar los restos vegetales contenidos en los depósitos sedimentológicos de las excavaciones arqueológicas, para establecer las condiciones paleoecológicas de la región y el posible uso de plantas. Se analizaron 50 muestras de... |
|
Palavras-chave: Arqueobotánica; Sedimentos; Semillas; Maderas; Polen; Archaeobotany; Sediments; Seeds; Wood; Pollen; Maestría; Botánica. |
| Ano: 2010 |
URL: http://hdl.handle.net/10521/142 |
| |
|
|
| Galván Escobedo, Iris Grisel. |
| El Museo Nacional de las Culturas (MNC) ubicado en el centro histórico de la ciudad de México, es un edificio que fue construido en 1734 sobre los restos de la antigua ciudad de México -Tenochtitlán habitada por los mexicas (1324-1521). En el MNC se realizaron excavaciones arqueológicas con el objeto de recuperar información histórica relacionada con el sitio, tendientes a una restauración integral del edificio y su posterior adecuación museográfica. De los trabajos arqueológicos se derivó esta tesis que tuvo como finalidad recuperar los restos vegetales contenidos en los depósitos sedimentológicos de las excavaciones arqueológicas, para establecer las condiciones paleoecológicas de la región y el posible uso de plantas. Se analizaron 50 muestras de... |
|
Palavras-chave: Arqueobotánica; Sedimentos; Semillas; Maderas; Polen; Archaeobotany; Sediments; Seeds; Wood; Pollen; Maestría; Botánica. |
| Ano: 2010 |
URL: http://hdl.handle.net/10521/142 |
| |
|
| |
|
| |
|
|
| Osterkamp,Isa Carla; Lara,Daniela Müller de; Gonçalves,Thaís Alves Pereira; Kauffmann,Marjorie; Périco,Eduardo; Stülp,Simone; Machado,Neli Teresinha Galarce; Uhl,Dieter; Jasper,André. |
| ABSTRACT Charcoal is widely accepted as evidence of the occurrence of palaeo-wildfire. Although fossil charcoal remains have been used in many studies, investigation into the anatomical changes occurring during charring are few. The present study analyses changes in selected anatomical characters during artificial charring of modern wood of three species of the genus Araucaria (i.e. Araucaria angustifolia, Araucaria bidwillii and Araucaria columnaris). Wood samples of the studied species was charred under controlled conditions at varying temperatures. Measurements of anatomical features of uncharred wood and artificial charcoal were statistically analysed. The anatomical changes were statistically correlated with charring temperatures and most of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anatomy; Araucariaceae; Araucaria angustifolia; Araucaria bidwillii; Araucaria columnaris; Charcoal; Wood. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062018000200198 |
| |
|
|
| Zanuncio,Antônio José Vinha; Carvalho,Amélia Guimarães; Carneiro,Angélica de Cassia Oliveira; Valenzuela,Paulina; Gacitúa,William; Leite,Fernando Palha; Colodette,Jorge Luiz. |
| Abstract: The objective of this work was to test a new methodology to assess the resistance of trees to wind damage and determine the characteristics that increase clone resistance to winds. Tree resistance to breakage, basic density, ultrastructure, anatomy, mechanical properties, and wood growth stress have been evaluated in seven Eucalyptus grandis × Eucalyptus urophylla clones, collected from a region with a high incidence of wind damage. The Pearson correlation coefficient between the tree resistance to breakage and the ratio between the area damaged by the winds and the total planted area was -0.839, showing the efficiency of the methodology adopted and that high breaking strength results in a smaller area affected by wind damage. Trees with a high... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Eucalyptus grandis × Eucalyptus urophylla; Basic density; Cell wall fraction; Cell wall ultrastructure; Fiber; Wood. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2017001100969 |
| |
|
| |
|
|
| da Silva Leonardo, Fernanda Viana; Rocha, Henrique Figueiredo; Hurtado de Mendoza, Zaira Morais dos Santos. |
| Os compostos quinônicos, em sua grande parte, são gerados na fração extrativos das madeiras, em um sistema biológico complexo e variável. Por não fazerem parte da parede celular, eles recebem o nome de compostos secundários. Na literatura tem indicações de uso em diversos segmentos, que vão desde a indústria alimentícia até a indústria farmacêutica. Dentro da área de utilização industrial da madeira, eles são pouco desejáveis, visto que são tratados apenas como substâncias acidentais nas cadeias produtoras de celulose, papel, carvão vegetal e serraria. Apesar de sua pouca quantidade em relação aos outros compostos químicos chamados de fundamentais, essas substâncias vem recebendo atenção especial dos pesquisadores, revelando uma gama diversificada de... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Recursos Florestais Produtos florestais; Madeira; Tecnologia Forest products; Wood; Technology. |
| Ano: 2015 |
URL: http://pfb.cnpf.embrapa.br/pfb/index.php/pfb/article/view/816 |
| |
|
|
| Cruz, M.. |
| En la Isla Baltra, entre abril a agosto/89 se pusieron once tipos de diferentes maderas expuestas al medio ambiente marino, habiéndose encontrado 7 organismos que degradaron la madera, de los cuales 6 son moluscos bivalvos: Bankia carinata, B. gouldi, Lyrodus medilobata, l. pedicellatus, Teredo bartschi, T. furcifera y un isópodo del género limnoria. De los Bivalvos perforadores, T. furcífera ha sido la especie más abundante y frecuente, seguida de L. pedicellatus. Las especies ovadas que se encontraron fueron: T. furcífera, L. pedicellatus, L. medilobata y T. bartschi, de las cuales T. furcífera se presentó como la más abundante y frecuente. la madera que presentó el mayor número de hembras con huevos fue el laurel. De los 11 tipos de maderas expuestos al... |
| Tipo: Journal Contribution |
Palavras-chave: Marine molluscs; Fouling organisms; Islands; Wood; Islands; Wood; Http://aims.fao.org/aos/agrovoc/c_3962; Http://aims.fao.org/aos/agrovoc/c_8421. |
| Ano: 1996 |
URL: http://hdl.handle.net/1834/2193 |
| |
|
| |
|
|
| Christoforo,André L.; Panzera,Tulio H.; Lahr,Francisco A. R.. |
| ABSTRACT According to the ABNT NBR 7190: 1997 standard, tensile strength of wood samples shall be defined as the ratio between the ultimate strength from a stress test and the specimen cross-sectional area (350 mm2). However, due to the complex wood anatomy and experimental difficulties, the fractured surface in tested samples are not perpendicular to the loading direction; therefore, such fractured surface becomes larger than the sample cross section, overestimating tensile strength by this method. Using an alternative approach, we aimed to determine the approximate fracture surface of wood specimens subjected to tensile test. For this purpose, we used the least square method to estimate tensile strength of four hardwood species, which were equally... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tensile Strength; Wood; Hardwood; Least Square Method. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000400533 |
| |
|
|
| Christoforo,André L.; Almeida,Andrea de S.; Lanini,Tamiris L. S.; Nogueira,Rodrigo de S.; Lahr,Francisco A. R.. |
| ABSTRACT For safety reasons, wood strength values, essential for structural dimensioning, are calculated based on the characteristic value, which corresponds to the 5% percentile of a given probability distribution model. For small samples, the Brazilian normative document ABNT NBR 7190 establishes an estimator of the characteristic wood strength, which can provide a significantly different result from the characteristic value coming from a suitable model of probability distribution. The main objective of this study was to evaluate the best probability distribution model (normal, lognormal, Weibull, and exponential) and the subsequent calculation of the characteristic value indicated by ABNT NBR 7190 (1997), allowing to evaluate its accuracy, being also... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Wood; Compression; Traction; Shear; Probability distribution; Characteristic value. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000100127 |
| |
|
| |
|
| |
|
|
| Cruz, M.; Torres, G.; Villamar, F.. |
| Se identifican 12 especies de moluscos bivalvos perforadores de la madera Rhyzophora harrisonii (Mangle) en la costa ecuatoriana, de las cuales 11 especies son primeros registros para el Ecuador, ampliándose de esta manera su distribución anterior. Se describen las principales características taxonómicas de cada género y especie encontrada, agregándose dibujos de las paletas que se usaron en la identificación. Los resultados se presentan en gráficos, figuras, histogramas, tablas y mapas de distribución areal de las especies. en las conclusiones se discuten detalles que se han encontrado en los puertos de Esmeraldas, Manta, Salinas, Posorja y Base Naval Sur (Golfo de Guayaquil interior), completándose esta información con recomendaciones para cada puerto. |
| Tipo: Journal Contribution |
Palavras-chave: Marine molluscs; Fouling organisms; New records; Wood; Wood; Http://aims.fao.org/aos/agrovoc/c_8421. |
| Ano: 1987 |
URL: http://hdl.handle.net/1834/2132 |
| |
|
| |
|
| |
| Registros recuperados: 36 | |
|
|
|
