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| Registros recuperados: 12 | |
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| Davies, Peter. |
| This paper describes the influence of seawater ageing on composites used in a range of marine structures, from boats to tidal turbines. Accounting for environmental degradation is an essential element in the multi-scale modelling of composite materials but it requires reliable test data input. The traditional approach to account for ageing effects, based on testing samples after immersion for different periods, is evolving towards coupled studies involving strong interactions between water diffusion and mechanical loading. These can provide a more realistic estimation of long-term behaviour but still require some form of acceleration if useful data, for 20 year lifetimes or more, are to be obtained in a reasonable time. In order to validate extrapolations... |
| Tipo: Text |
Palavras-chave: Seawater; Immersion; Durability; Damage; Coupling. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00340/45167/44603.pdf |
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| Davies, Peter; Arhant, Mael. |
| The recent introduction of liquid acrylic thermoplastic matrix resins which can impregnate fibre reinforcements using traditional infusion moulding offers significant potential for future composite structures in marine applications, such as marine energy devices. However, to date very few results are available to evaluate the long term durability of these composites in a marine environment. This paper describes results from a series of cyclic loading tests on glass and carbon fibre reinforced acrylic composites under both tension and four point flexural loading. Tests were performed before and after aging in natural seawater. The results were compared to results for a glass/epoxy used today in marine structures, and show a lower loss of both static and... |
| Tipo: Text |
Palavras-chave: Acrylic; Fatigue; Immersion; Seawater. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00444/55596/57249.pdf |
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| Silva,Rodrigo J. da; Ferreira Junior,José M.; Silva,Flavia A.; Santos,Antonio C. M. dos; Lima,Saulo de O.; Silva,Rubens R. da. |
| ABSTRACT The development and survival of Eucalyptus urograndis plants may be influenced by products based on humic fractions of the organic matter, purified MAP and soil conditioners, such as hydrogel. Thus, the present study aimed to evaluate the effect of the commercial products Fertiactyl®, based on humic substances, purified MAP and hydrogel on the post-planting development and survival of Eucalyptus urograndis. The experiment was conducted in a randomized block design, with 25 treatments and four replicates, each of which consisted of 6 plants. The immersion of the tubes in solution with doses of Fertiactyl® and purified MAP promoted the increase in the development and survival of the plants. In the preparation of the hydrogel, the use of solution... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Electrical conductivity; Hydration; Immersion. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000700625 |
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| Davies, Peter; Le Gac, Pierre-yves; Le Gall, Maelenn. |
| A new matrix resin was recently introduced for composite materials, based on acrylic resin chemistry allowing standard room temperature infusion techniques to be used to produce recyclable thermoplastic composites. This is a significant advance, particularly for more environmentally-friendly production of large marine structures such as boats. However, for such applications it is essential to demonstrate that composites produced with these resins resist sea water exposure in service. This paper presents results from a wet aging study of unreinforced acrylic and glass and carbon fibre reinforced acrylic composites. It is shown that the acrylic matrix resin is very stable in seawater, showing lower property losses after seawater aging than those of a... |
| Tipo: Text |
Palavras-chave: Acrylic; Thermoplastic; Infusion; Seawater; Immersion. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00347/45815/45541.pdf |
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| Le Guen-geffroy, Antoine; Davies, Peter; Le Gac, Pierre Yves; Habert, Bertrand. |
| Carbon fiber reinforced composite materials are finding new applications in highly loaded marine structures such as tidal turbine blades and marine propellers. Such applications require long-term damage resistance while being subjected to continuous seawater immersion. However, few data exist on which to base material selection and design. This paper provides a set of results from interlaminar fracture tests on specimens before and after seawater ageing. The focus is on delamination as this is the main failure mechanism for laminated composites under out-of-plane loading. Results show that there are two contributions to changes in fracture toughness during an accelerated wet ageing program: effects due to water and effects due to physical ageing. These are... |
| Tipo: Text |
Palavras-chave: Composite; Delamination; Seawater; Immersion; Ageing. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00652/76410/77458.pdf |
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| Ferraz, Denes; Ramalho, Werther Pereira; Vale, Luís Sérgio Rodrigues. |
| The production of forest species that present seedlings with exogenous dormancy is limited by low germination rates, which can be overcome by rupturing or weakening the tegument. This study aimed to evaluate the efficiency of low-cost methods of overcoming dormancy and determine the effect of storage on the seeds of Enterolobium contortisiliquum. Four storage periods were used, freshly collected seeds (0), stored for 6, 12 and 18 months, and four methods were applied, mechanical scarification and immersion in water (EI), mechanical scarification (ES), immersion in water (IM) and control (TE). We obtained the percentage values of seedling emergence (EP) and the mean emergence time (TME). Conductivity and moisture were obtained as indicators of the physical... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Exogenous dormancy; Immersion; Mechanical scarification; Leguminous plants; Seedling production; Pacara earpod tree.. |
| Ano: 2019 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/42602 |
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| Ferraz, Denes; Ramalho, Werther Pereira; Vale, Luís Sérgio Rodrigues. |
| The production of forest species that present seedlings with exogenous dormancy is limited by low germination rates, which can be overcome by rupturing or weakening the tegument. This study aimed to evaluate the efficiency of low-cost methods of overcoming dormancy and determine the effect of storage on the seeds of Enterolobium contortisiliquum. Four storage periods were used, freshly collected seeds (0), stored for 6, 12 and 18 months, and four methods were applied, mechanical scarification and immersion in water (EI), mechanical scarification (ES), immersion in water (IM) and control (TE). We obtained the percentage values of seedling emergence (EP) and the mean emergence time (TME). Conductivity and moisture were obtained as indicators of the physical... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Exogenous dormancy; Immersion; Mechanical scarification; Leguminous plants; Seedling production; Pacara earpod tree.. |
| Ano: 2019 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/42602 |
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| Registros recuperados: 12 | |
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