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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Caracterização tecnológica da madeira de Corymbia maculata, Eucalyptus cloeziana e E. resinifera para a aplicação no design de Produtos de Maior Valor Agregado (PMVA) / Technological characterization of wood Corymbia maculata, Eucalyptus cloeziana and E. resinifera for application in the design of High Value Added Products (HVAP)

Leite, Marta Karina 19 November 2013 (has links)
As áreas de plantações florestais existentes no país são insuficientes para o atendimento da demanda por madeira nos mais diversos segmentos, sendo que, para a indústria de produtos de maior valor agregado (PMVA) e construção civil, de modo geral, a madeira é, em geral, procedente da exploração não sustentável das florestas naturais. O uso da madeira de reflorestamento é uma possível alternativa de disponibilização de madeira de qualidade, adequada aos requisitos tecnológicos dos PMVA, sem colocar em risco de extinção as espécies nativas. Neste contexto, o presente trabalho teve como principal objetivo caracterizar tecnologicamente madeira de três espécies exóticas com boa possibilidade de reflorestamento na região sudeste do país, sendo elas, de Corymbia maculata, Eucalyptus cloeziana e E. resinifera, para aplicação da madeira no design de PMVA. Os ensaios laboratoriais compreenderam em caracterizar a madeira quanto suas propriedades (i) organolépticas - cor; (ii) físicas - densidade básica, umidade e variação dimensional volumétrica; (iii) anatômicas - frequência de vasos, diâmetro de lume, espessura de parede da fibra e comprimento de fibras; (iv) mecânicas - MOR e MOE para flexão estática e compressão paralela, resistência à tração normal e cisalhamento e dureza Janka, além de (v) qualidade de superfície com acabamento em filme - rugosidade, resistência do filme ao impacto, ao risco, à abrasão e à mancha. Os resultados de avaliação da cor indicaram diferença de tonalidade e cor entre as espécies. A avaliação física indicou uma semelhança na densidade básica das madeiras das espécies analisadas, de médio a baixo teor de umidade e variação dimensional favorável para aplicação em PMVA. Na caracterização das propriedades mecânicas os resultados de MOR e MOE foram similares às madeiras consideradas nobres e utilizadas em PMVA. Nos ensaios de qualidade de superfície, os resultados encontrados para rugosidade foram bastante satisfatórios, compreendendo às classes N5 a N9 da NBR 8404/1984, com alta possibilidade de aplicação em produtos que requerem boa qualidade de superfície. Os resultados permitem concluir que as três espécies estudadas tem alto potencial para aplicação no design em PMVA. / The areas of forest plantations in the country are insufficient to meet the demand for wood in various segments, how to the industry of Products with Higher Added Value (HVAP) and construction, generally, the wood is, coming from unsustainable exploitation of natural forests. The use of wood from reforestation is a possible alternative for the provision of quality wood suitable to the technological requirements of PMVA without putting endangered native species. In this context, the present study aimed to characterize technologically three wooden exotic species with good potential for reforestation in the southeast of the country, being, Corymbia maculata, Eucalyptus cloeziana and E. resinifera for application the wood to design HVAP. The laboratory tests are understood in timber characteristics how in this properties (i) organoleptic properties - color, (ii) physical - Basic density , moisture content and volumetric dimensional variation, and (iii) anatomical - frequency vessel, lumen diameter , wall thickness of the fiber and fiber length, (iv) mechanical - MOR and MOE for bending and compression tests, tensile normal and shear and Janka hardness, and (v) quality of surface finish film - roughness , film resistance to impact, to risk, to abrasion and stain. The color evaluation results showed a difference the tone and color among species. The physical evaluation indicated a similarity in the basic density of wood species analyzed, medium to low moisture content and dimensional variation favorable for application in HVAP. The characterization of the mechanical properties of the MOR and MOE results were similar to those considered noble woods and used in HVAP. In tests if surface quality, the results were quite satisfactory for roughness, comprising rating N5 to N9 NBR 8404/1984, with a high possibility of application in products that require good surface quality. The results indicate that the three species has high potential for application to design HVAP.
2

Caracterização tecnológica da madeira de Corymbia maculata, Eucalyptus cloeziana e E. resinifera para a aplicação no design de Produtos de Maior Valor Agregado (PMVA) / Technological characterization of wood Corymbia maculata, Eucalyptus cloeziana and E. resinifera for application in the design of High Value Added Products (HVAP)

Marta Karina Leite 19 November 2013 (has links)
As áreas de plantações florestais existentes no país são insuficientes para o atendimento da demanda por madeira nos mais diversos segmentos, sendo que, para a indústria de produtos de maior valor agregado (PMVA) e construção civil, de modo geral, a madeira é, em geral, procedente da exploração não sustentável das florestas naturais. O uso da madeira de reflorestamento é uma possível alternativa de disponibilização de madeira de qualidade, adequada aos requisitos tecnológicos dos PMVA, sem colocar em risco de extinção as espécies nativas. Neste contexto, o presente trabalho teve como principal objetivo caracterizar tecnologicamente madeira de três espécies exóticas com boa possibilidade de reflorestamento na região sudeste do país, sendo elas, de Corymbia maculata, Eucalyptus cloeziana e E. resinifera, para aplicação da madeira no design de PMVA. Os ensaios laboratoriais compreenderam em caracterizar a madeira quanto suas propriedades (i) organolépticas - cor; (ii) físicas - densidade básica, umidade e variação dimensional volumétrica; (iii) anatômicas - frequência de vasos, diâmetro de lume, espessura de parede da fibra e comprimento de fibras; (iv) mecânicas - MOR e MOE para flexão estática e compressão paralela, resistência à tração normal e cisalhamento e dureza Janka, além de (v) qualidade de superfície com acabamento em filme - rugosidade, resistência do filme ao impacto, ao risco, à abrasão e à mancha. Os resultados de avaliação da cor indicaram diferença de tonalidade e cor entre as espécies. A avaliação física indicou uma semelhança na densidade básica das madeiras das espécies analisadas, de médio a baixo teor de umidade e variação dimensional favorável para aplicação em PMVA. Na caracterização das propriedades mecânicas os resultados de MOR e MOE foram similares às madeiras consideradas nobres e utilizadas em PMVA. Nos ensaios de qualidade de superfície, os resultados encontrados para rugosidade foram bastante satisfatórios, compreendendo às classes N5 a N9 da NBR 8404/1984, com alta possibilidade de aplicação em produtos que requerem boa qualidade de superfície. Os resultados permitem concluir que as três espécies estudadas tem alto potencial para aplicação no design em PMVA. / The areas of forest plantations in the country are insufficient to meet the demand for wood in various segments, how to the industry of Products with Higher Added Value (HVAP) and construction, generally, the wood is, coming from unsustainable exploitation of natural forests. The use of wood from reforestation is a possible alternative for the provision of quality wood suitable to the technological requirements of PMVA without putting endangered native species. In this context, the present study aimed to characterize technologically three wooden exotic species with good potential for reforestation in the southeast of the country, being, Corymbia maculata, Eucalyptus cloeziana and E. resinifera for application the wood to design HVAP. The laboratory tests are understood in timber characteristics how in this properties (i) organoleptic properties - color, (ii) physical - Basic density , moisture content and volumetric dimensional variation, and (iii) anatomical - frequency vessel, lumen diameter , wall thickness of the fiber and fiber length, (iv) mechanical - MOR and MOE for bending and compression tests, tensile normal and shear and Janka hardness, and (v) quality of surface finish film - roughness , film resistance to impact, to risk, to abrasion and stain. The color evaluation results showed a difference the tone and color among species. The physical evaluation indicated a similarity in the basic density of wood species analyzed, medium to low moisture content and dimensional variation favorable for application in HVAP. The characterization of the mechanical properties of the MOR and MOE results were similar to those considered noble woods and used in HVAP. In tests if surface quality, the results were quite satisfactory for roughness, comprising rating N5 to N9 NBR 8404/1984, with a high possibility of application in products that require good surface quality. The results indicate that the three species has high potential for application to design HVAP.
3

Étude du potentiel d'une souche albinos de Ceratocystis resinifera pour la protection biologique du bois contre le bleuissement

Morin, Chantal 11 April 2018 (has links)
Malgré le fait que la coloration de l'aubier par les champignons de bleuissement affecte seulement l'esthétique du bois sans altérer ses propriétés, elle abaisse sa valeur marchande et freine son exportation, causant des pertes financières importantes à l'industrie forestière. L'utilisation de souches albinos (non pigmentées) de champignons de bleuissement est une approche de lutte biologique prometteuse permettant de traiter les billots immédiatement après la coupe. L'objectif principal de ce projet de doctorat était donc de développer une souche albinos d'une espèce à croissance rapide, le Ceratocystis resinifera, afin de l'utiliser comme agent biologique de protection du bois contre le bleuissement. À partir d'ascospores de C. resinifera, nous avons réussi à isoler une souche albinos que nous avons nommée Kasper. Le potentiel de Kasper à prévenir le bleuissement du bois a été testé et comparé à celui de Cartapip-97, un agent de lutte biologique disponible sur le marché pour prévenir le bleuissement des billots de pin tordu et de pin rouge. Lors d'essais en laboratoire, Kasper a réduit jusqu'à 94.4% le bleuissement de billots d'épinette blanche, soit plus efficacement que Cartapip-97. Lors de quatre essais effectués sur le terrain dans la région de Québec, Kasper a permis de réduire jusqu'à 80% le bleuissement de billots d'épinette noire. Dans tous les cas, l'albinos de C. resinifera a été plus efficace que Cartapip-97 à l'exception d'un seul essai. Ces résultats suggèrent que des souches albinos dérivées du champignon C. resinifera pourraient être une source additionnelle d'agents de lutte biologique contre le bleuissement du bois. Pour s'assurer de l'innocuité environnementale de Kasper, des tests ont été effectués pour évaluer le pouvoir pathogène de ce dernier et de souches sauvages de C. resinifera sur des plants de conifères et de feuillus. C. resinifera a démontré un pouvoir pathogène parfois négligeable, parfois relativement élevé selon les conditions. Cependant, nous ne connaissons pas encore la nature des insectes vecteurs de C. resinifera, bien que cela semble peu probable que se soient des scolytes primaires capables d'attaquer des arbres sains. Nous n'avons donc pas pu conclure sur le risque de l'application opérationnelle de Kasper. Une étude sur la génétique et la structure des populations de C. resinifera a aussi été réalisée pour évaluer le risque d'utiliser Kasper à la grandeur du Canada et de perturber l'écologie de populations locales au cas où Kasper proviendrait d'une population génétiquement distincte des autres populations canadiennes. L'ADN de 129 isolats de C. resinifera provenant de neufs sites à travers le Canada a été amplifié avec 13 amorces qui ont généré 108 marqueurs RAPD (19 polymorphes, 54 allèles rares et 35 monomorphes). Les analyses de la fréquence allélique de ces marqueurs ont révélé une faible diversité génétique (//s = 0.045) ainsi qu'une différentiation génétique (OST= 27.4%) entre les populations de l'Est et celles de l'Ouest du Canada. La différentiation suggère la présence d'une barrière reproductive géographique située dans les Prairies canadiennes où la présence de plante-hôtes y est plus restreinte. Cependant, selon les analyses, cette barrière ne serait pas complètement impénétrable. / Sapstain of wood caused by ophiostomatoid fungi does not affect the structural properties of wood but, since it alters its appearance, it nevertheless reduces the value of wood products, thereby inducing considerable financial losses to the wood products industry. The application of albino strains derived from sapstain fungi is a promising biological control strategy against sapstain of wood. Therefore, the main objective of this Ph.D project was to develop an albino strain of an aggressive saspstain fungus, such as Ceratocystis resinifera, to prevent sapstain in freshly felled logs. We recovered an albino strain, named Kasper, from ascospores of C. resinifera and we tested its potential in preventing sapstain and compared its performance with an albino strain of O. piliferum, commercially available under the trade name Cartapip 97 as a biological control agent against sapstain on lodgepole pine and red pine logs. In a laboratory trial, Kasper reduced sapstain of white spruce logs up to 94.4% and was more efficient than Cartapip-97. In field trials conducted in an area north of Québec City, Kasper reduced sapstain of black spruce up to 80%. In three out of four field trials, Kasper was significantly more efficient than Cartapip-97 in reducing sapstain development. The exception was encountered in a 2003 trial conducted in a sawmill yard where Kasper did not reduce sapstain. These results suggest albino strains derived from C. resinifera might be an additional source of potential biocontrol agents against sapstain. To ensure the environmental innocuousness of large-scale applications of Kasper, we tested the pathogenicity of both wild-type and albino strains of C. resinifera in five greenhouse trials and in one field trial. This fungus showed weak to moderate pathogenic ability depending on conditions. However, we cannot conclude about the risk of using Kasper as a protective agent on logs since the nature of its insect vectors still remains unknown, although it is suspected to be fungal feeding insects that rarely attack healthy living trees. The development of a biological control agent derived from C. resinifera should include an assessment of the genetic variability and population structure of this fungus. This type of study, which is required for registration issues in countries such as Canada, would also help prevent the introduction of new genetic material into local populations, if Kasper were found to be genetically distinct. DNA of 129 isolates of C. resinifera from nine Canadian populations was amplifïed with 13 primers that generated 108 RAPD markers. The analysis of allelic frequencies showed an overall low genetic diversity among isolates (//s = 0.045). A notable genetic differentiation (OST= 27.4%) was nevertheless observed between Eastern and Western populations. This barrier of gene flow may resuit from the absence of host and intensive agriculture across the Great Plains but analysis suggested that this barrier is not totally impenetrable.

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