The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Christian Bussau - One of the best experts on this subject based on the ideXlab platform.
-
new deep sea nematoda enoplida thoracostomopsidae oncholaimidae enchelidiidae from a manganese nodule area of the eastern south pacific
Zoologica Scripta, 1995Co-Authors: Christian BussauAbstract:Five new nematode species are described from a mangancsc nodule area of the abyssal eastern South Pacific: Enoploides Tyrannis sp. n., Paramesacanthion abyssorum sp. n., P. forcepssp. n. (all three Thoracostomopsidae), Phylloncholaimus immanis gen. et sp. n. (Oncholaimidac), and Eurystomina absoluta sp. n. (Enchelidiidae). They are characterized by large size (body length 5000–23000 μm), short tails (c = 17–33), and strongly cuticularizcd, barrel-shaped buccal cavities with large teeth. With the exception of one male of E. Tyrannis from the surface of a manganese nodule, all other specimens were found in the sediment. The new species are sporadic in distribution and represented by few individuals.
-
New deep‐sea Nematoda (Enoplida, Thoracostomopsidae, Oncholaimidae, Enchelidiidae) from a manganese nodule area of the eastern South Pacific*
Zoologica Scripta, 1995Co-Authors: Christian BussauAbstract:Five new nematode species are described from a mangancsc nodule area of the abyssal eastern South Pacific: Enoploides Tyrannis sp. n., Paramesacanthion abyssorum sp. n., P. forcepssp. n. (all three Thoracostomopsidae), Phylloncholaimus immanis gen. et sp. n. (Oncholaimidac), and Eurystomina absoluta sp. n. (Enchelidiidae). They are characterized by large size (body length 5000–23000 μm), short tails (c = 17–33), and strongly cuticularizcd, barrel-shaped buccal cavities with large teeth. With the exception of one male of E. Tyrannis from the surface of a manganese nodule, all other specimens were found in the sediment. The new species are sporadic in distribution and represented by few individuals.
Akira Kohyama - One of the best experts on this subject based on the ideXlab platform.
-
microstructural evolution analysis of nite sic sic composite using tem examination and dual ion irradiation
Journal of Nuclear Materials, 2007Co-Authors: Hirotatsu Kishimoto, Kazumi Ozawa, Okinobu Hashitomi, Akira KohyamaAbstract:Abstract Irradiation effects in a SiC/SiC composite reinforced by Tyranno-SA fibers and produced by an innovative processing method, nano-powder infiltration and transient eutectic phase (NITE) processing, were investigated. Dual-beam ion irradiation methods and energy-filtered transmission electron microscopy were used in the investigation. The NITE SiC matrix had dense, isotropic grains several hundreds nm in diameter. A small amount of secondary phases from residual additives were found within the SiC fiber bundles. Dual-ion irradiations achieved a dose of 60 dpa at 1200 °C. TEM investigation showed no significant modification by irradiation in either the Tyranno-SA fibers or the NITE SiC matrix, except for a small amount of micro-cavity formation. The synergistic effects of heavy irradiation and helium atoms in NITE SiC/SiC composites at elevated temperature are discussed.
-
preparation of sic sic composites by hot pressing using tyranno sa fiber as reinforcement
Journal of the American Ceramic Society, 2003Co-Authors: Shaoming Dong, Yutai Katoh, Akira KohyamaAbstract:The development of advanced Tyranno SA SiC fiber with a near-stoichiometric composition and a well-crystallized microstructure has made it possible to prepare SiC/SiC composites even under harsh conditions. To assess the reinforcing effectiveness of Tyranno SA fiber at high temperature under pressure, unidirectional SiC/SiC composites were prepared by hot pressing, using pyrolytic carbon (PyC)-coated Tyranno SA fiber as a reinforcement and nanopowder SiC with sintering additives for matrix formation. The effects of sintering conditions on the microstructural evolution and mechanical properties of the composites were characterized. As the sintering temperature increased (from 1720° to 1780°C) and the sintering pressure increased (from 15 to 20 MPa), the density of the composites gradually increased. Simultaneously, the elastic modulus, the proportional limit stress, and the strength, under both bend and tensile tests, also improved. At lower temperature and/or pressure, long fiber pullout was a predominant fracture behavior, indicating relatively weak fiber/matrix bonding. However, at high temperature and/or pressure, short fiber pullout became a main fracture characteristic, indicating relatively strong fiber/matrix bonding. These phenomena were also confirmed by the characteristics of the hysteresis loops derived from the stress–strain curves produced by a tensile test with unloading–reloading cycles. In the present investigation, the reinforcement of Tyranno SA fiber is effective for providing noncatastrophic fracture behavior to composites.
Cathie Vixguterl - One of the best experts on this subject based on the ideXlab platform.
-
influence of chemical and physical properties of the last generation of silicon carbide fibres on the mechanical behaviour of sic sic composite
Journal of The European Ceramic Society, 2012Co-Authors: E Buet, C Sauder, S Poissonnet, Patrice Brender, Roger Gadiou, Cathie VixguterlAbstract:Abstract SiC/SiC composites reinforced with near stoichiometric SiC ceramic fibres (Hi-Nicalon S and SA3 Tyranno fibres) are attractive materials to be used in nuclear environment. Netherless, their mechanical properties must be improved and controlled. For example, SA3 Tyranno fibres (TSA3) -reinforced composites exhibit a brittle behaviour whereas composites reinforced by Hi-Nicalon S (HNS) fibres exhibit a conventional damage tolerant response. This difference is related to the nature of the fibre/matrix (F/M) coupling. The aim of this work was to identify the SiC fibres characteristics influencing the F/M coupling and consequently the mechanical properties of the composites. The experimental results point out that the TSA3 fibres exhibit a granular and rough surface leading to an increase of the residual stress and the interfacial shear stress in the SiC/SiC composites. Beside the roughness, the experimental results also point out that the surface chemistry of the SiC fibres significantly influence the F/M bonding.
E Buet - One of the best experts on this subject based on the ideXlab platform.
-
influence of chemical and physical properties of the last generation of silicon carbide fibres on the mechanical behaviour of sic sic composite
Journal of The European Ceramic Society, 2012Co-Authors: E Buet, C Sauder, S Poissonnet, Patrice Brender, Roger Gadiou, Cathie VixguterlAbstract:Abstract SiC/SiC composites reinforced with near stoichiometric SiC ceramic fibres (Hi-Nicalon S and SA3 Tyranno fibres) are attractive materials to be used in nuclear environment. Netherless, their mechanical properties must be improved and controlled. For example, SA3 Tyranno fibres (TSA3) -reinforced composites exhibit a brittle behaviour whereas composites reinforced by Hi-Nicalon S (HNS) fibres exhibit a conventional damage tolerant response. This difference is related to the nature of the fibre/matrix (F/M) coupling. The aim of this work was to identify the SiC fibres characteristics influencing the F/M coupling and consequently the mechanical properties of the composites. The experimental results point out that the TSA3 fibres exhibit a granular and rough surface leading to an increase of the residual stress and the interfacial shear stress in the SiC/SiC composites. Beside the roughness, the experimental results also point out that the surface chemistry of the SiC fibres significantly influence the F/M bonding.
Shaoming Dong - One of the best experts on this subject based on the ideXlab platform.
-
preparation of sic sic composites by hot pressing using tyranno sa fiber as reinforcement
Journal of the American Ceramic Society, 2003Co-Authors: Shaoming Dong, Yutai Katoh, Akira KohyamaAbstract:The development of advanced Tyranno SA SiC fiber with a near-stoichiometric composition and a well-crystallized microstructure has made it possible to prepare SiC/SiC composites even under harsh conditions. To assess the reinforcing effectiveness of Tyranno SA fiber at high temperature under pressure, unidirectional SiC/SiC composites were prepared by hot pressing, using pyrolytic carbon (PyC)-coated Tyranno SA fiber as a reinforcement and nanopowder SiC with sintering additives for matrix formation. The effects of sintering conditions on the microstructural evolution and mechanical properties of the composites were characterized. As the sintering temperature increased (from 1720° to 1780°C) and the sintering pressure increased (from 15 to 20 MPa), the density of the composites gradually increased. Simultaneously, the elastic modulus, the proportional limit stress, and the strength, under both bend and tensile tests, also improved. At lower temperature and/or pressure, long fiber pullout was a predominant fracture behavior, indicating relatively weak fiber/matrix bonding. However, at high temperature and/or pressure, short fiber pullout became a main fracture characteristic, indicating relatively strong fiber/matrix bonding. These phenomena were also confirmed by the characteristics of the hysteresis loops derived from the stress–strain curves produced by a tensile test with unloading–reloading cycles. In the present investigation, the reinforcement of Tyranno SA fiber is effective for providing noncatastrophic fracture behavior to composites.
