The current concern with the environment promotes the development of new technologies for production with use of alternative materials, from renewable resources, and changes in production processes, having as main obj...The current concern with the environment promotes the development of new technologies for production with use of alternative materials, from renewable resources, and changes in production processes, having as main objective the reduction of environmental impact. One of the alternatives for cleaner production is the use of castor oil derivatives instead of non-renewable sources, such as adhesives based on PVA （polyvinyl acetate）, applied in the manufacturing process of glued laminated bamboo. Based on the versatility of the bamboo laminate and the castor oil, and from the perspective of sustainability, this study aims to contribute to the application of new materials and processes, used in the manufacturing industry, by proposing the use of the polyurethane adhesive based on castor oil for glued laminated bamboo manufacturing, which can later be used in the manufacture of several products. To verify the applicability of the polyurethane adhesive based on castor oil in the glued laminated bamboo manufacture, mechanical tests of traction and shearing of the glue sheet were performed in specimens of the said material, and the results were compared with the Cascorez 2590 and Waterbond adhesives. The results showed that the polyurethane adhesive based on castor oil, in the traction test, has superior performance than the Waterbond adhesive and slightly below than the Cascorez 2590 adhesive, but in the shear test, the polyurethane adhesive based on castor oil presented a slightly inferior performance than the other two adhesives used in the comparison.展开更多
Copper （Cu） contamination in the environment has been increased during the years with agricultural and industrial activities. Biotechnological approaches are needed for bioremediation in these areas. The aims of thi...Copper （Cu） contamination in the environment has been increased during the years with agricultural and industrial activities. Biotechnological approaches are needed for bioremediation in these areas. The aims of this study were i） to evaluate the phytoreme- diation capacity of the high-yielding bioenergy plant castor bean （Ricinus communis L.） in vineyard soils （Inceptisol and Mollisol） contaminated with Cu and a Cu mining waste; ii） to characterize the castor bean as a Cu phytoremediation plant; and iii） to evaluate the nutrient uptake by castor bean. Castor bean plants cultivated in soil with toxic levels of Cu for 57 d exhibited high phytomass production, a high tolerance index of roots＇ fresh mass and shoots＇ dry mass, a high level of Cu phytoaccumulation in the roots and also, a robust capacity for Cu phytostabilization. Furthermore, castor bean plants did not significantly deplete soil nutrients （such as N, P, and Mg） during cultivation. Plants cultivated in Inceptisol, Mollisol and Cu mining waste exhibited a strong potential for Cu phytoaccumulation, with values of 5900, 3 052 and 2805 g ha-1, respectively. In addition, the castor bean＇s elevated phytomass production and strong growth in Cu-contaminated soils indicated a high level of Cu phytoaccumulation and a potential application in biofuels. These findings indicate that the castor bean is a efficient hyperaccumulator of Cu and a potential candidate plant for the phytoremediation of Cu-contaminated soil.展开更多
文摘The current concern with the environment promotes the development of new technologies for production with use of alternative materials, from renewable resources, and changes in production processes, having as main objective the reduction of environmental impact. One of the alternatives for cleaner production is the use of castor oil derivatives instead of non-renewable sources, such as adhesives based on PVA （polyvinyl acetate）, applied in the manufacturing process of glued laminated bamboo. Based on the versatility of the bamboo laminate and the castor oil, and from the perspective of sustainability, this study aims to contribute to the application of new materials and processes, used in the manufacturing industry, by proposing the use of the polyurethane adhesive based on castor oil for glued laminated bamboo manufacturing, which can later be used in the manufacture of several products. To verify the applicability of the polyurethane adhesive based on castor oil in the glued laminated bamboo manufacture, mechanical tests of traction and shearing of the glue sheet were performed in specimens of the said material, and the results were compared with the Cascorez 2590 and Waterbond adhesives. The results showed that the polyurethane adhesive based on castor oil, in the traction test, has superior performance than the Waterbond adhesive and slightly below than the Cascorez 2590 adhesive, but in the shear test, the polyurethane adhesive based on castor oil presented a slightly inferior performance than the other two adhesives used in the comparison.
基金Supported by the Coordenao de Aperfeic oamento de Pessoal de N'vel Superior (CAPES) of Brazil and the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) of Brazil
文摘Copper （Cu） contamination in the environment has been increased during the years with agricultural and industrial activities. Biotechnological approaches are needed for bioremediation in these areas. The aims of this study were i） to evaluate the phytoreme- diation capacity of the high-yielding bioenergy plant castor bean （Ricinus communis L.） in vineyard soils （Inceptisol and Mollisol） contaminated with Cu and a Cu mining waste; ii） to characterize the castor bean as a Cu phytoremediation plant; and iii） to evaluate the nutrient uptake by castor bean. Castor bean plants cultivated in soil with toxic levels of Cu for 57 d exhibited high phytomass production, a high tolerance index of roots＇ fresh mass and shoots＇ dry mass, a high level of Cu phytoaccumulation in the roots and also, a robust capacity for Cu phytostabilization. Furthermore, castor bean plants did not significantly deplete soil nutrients （such as N, P, and Mg） during cultivation. Plants cultivated in Inceptisol, Mollisol and Cu mining waste exhibited a strong potential for Cu phytoaccumulation, with values of 5900, 3 052 and 2805 g ha-1, respectively. In addition, the castor bean＇s elevated phytomass production and strong growth in Cu-contaminated soils indicated a high level of Cu phytoaccumulation and a potential application in biofuels. These findings indicate that the castor bean is a efficient hyperaccumulator of Cu and a potential candidate plant for the phytoremediation of Cu-contaminated soil.
