Hydrogen barrier coatings and liners for steel pipelines

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Large Ecosystem Service Benefits of Assisted Natural Regeneration

China manages the largest monoculture plantations in the world, with 24% being Chinese fir plantations. Maximizing the ecosystem services of Chinese fir plantations has important implications in global carbon cycle and biodiversity protection. Assisted natural regeneration (ANR) is a practice to convert degraded lands into more productive forests with great ecosystems services. However, the quantitative understanding of ANR ecosystem service benefits is very limited. We conducted a comprehensive field manipulation experiment to evaluate the ANR potentials. We quantified and compared key ecosystem services including surface runoff, sediment yield, dissolved organic carbon export, plant diversity, and aboveground carbon accumulation of ANR of secondary forests dominated by Castanopsis carlesii to that of Chinese fir and C. carlesii plantations. Our results showed that ANR of C. carlesii forest reduced surface runoff and sediment yield up to 50% compared with other young plantations in the first 3 years and substantially increased plant diversity. ANR also reduced the export of dissolved organic carbon by 60–90% in the first 2 years. Aboveground biomass of the young ANR forest was approximately 3–4 times of that of other young plantations, while aboveground biomass of mature ANR forests was approximately 1.4 times of that of mature Chinese fir plantations of the same age. If all Chinese fir plantations in China were replaced by ANR forests, potentially 0.7 Pg more carbon will be stored in aboveground in one rotation (25 years). The results indicate that ANR triggers positive feedbacks among soil and water conservation, biodiversity protection, and biomass accumulation and thereby enhances ecosystem services

Feasibility study on dissimilar materials joint made by friction stir forming

M.S. University of Hawaii at Manoa 2014.Includes bibliographical references.The need to join dissimilar materials is common to many industry sectors as the current demand is for the products of enhanced performance, reduced cost, weight reduction, optimized of properties or the tailored of the properties for specific applications. This paper is focused on studying the different joint structures made from different material combinations by Friction Stir Forming process. At present, joining Al to steel are successfully joined by this process, the present paper investigates the possibility of making strong joints from Fe-Al, Mg-Steel, as well as Aluminum to carbon fiber composites (Al-CFRP) material combinations. The manufacturing industries are driven by using new lightweight material alternative to steel to form a thinner and stronger joint, which leads to a greater emphasis on the improvement of joining processes to allow interlocking formed by the material itself instead of using any rivets, bolts, adhesives, or any other mass addition. Friction Stir Forming is a relatively new process, which is an alternative to the mechanical fasteners. It is a process where the tool works heated materials into close contact, causing them to form a solid-state joint. No melting of materials occurs. Instead, the joint is formed by plastic deformation of the pieces. The previous part of the experiment is to define the important factors involved during the process, as well as the microstructure analysis on Al-Steel joint. Therefore, at this stage of the experiment, the joint made by Fe-Al, Mg-Steel, as well as Aluminum to carbon fiber composites (Al-CFRP) are studied. Our study showed that friction stir forming process could be carried out over a wide range of operating parameters. It is a process where the shape of the joint could be changed according to the design of anvil. By changing the joint shape, the strength and the quality could be affected. The friction stir forming joints are strong to satisfy the industry requirement. It is possible to form joints with lightweight materials using friction stir forming techniques. The material used to form the joint could affect the strength of the joint

Extremely High Strength and Work Hardening Ability in a Metastable High Entropy Alloy

This article studies the design of a transformation induced plasticity (TRIP) assisted high entropy alloy (HEA) with enhanced strength using two strands of motiviation

Hierarchical features infused heterogeneous grain structure for extraordinary strength-ductility synergy

A synergistic balance of strength and ductility was achieved in a prototypical fcc-based Al0.3CoCrFeNi complex concentrated alloy by incorporating hierarchical microstructural features into heterogeneous grain structure. Microstructural hierarchy was composed of different morphologies and size-scales of B2 precipitates and nano-twins that were incorporated in parent fcc matrix, which, additionally, was comprised of domains of fine and coarse grains. Strain partitioning between refined and coarse grains produced geometrically necessary dislocations during plastic deformation. This facilitated long-range back stresses during further deformation leading to simultaneous enhancement of strength and ductility. Furthermore, B2 precipitates complemented back stress and increased inherent matrix strength

Data from: Large ecosystem service benefits of assisted natural regeneration

China manages the largest monoculture plantations in the world, with 24% being Chinese fir plantations. Maximizing the ecosystem services of Chinese fir plantations has important implications in global carbon cycle and biodiversity protection. Assisted natural regeneration (ANR) is a practice to convert degraded lands into more productive forests with great ecosystems services. However, the quantitative understanding of ANR ecosystem service benefits is very limited. We conducted a comprehensive field manipulation experiment to evaluate the ANR potentials. We quantified and compared key ecosystem services including surface runoff, sediment yield, dissolved organic carbon export, plant diversity, and aboveground carbon accumulation of ANR of secondary forests dominated by Castanopsis carlesii to that of Chinese fir and C. carlesii plantations. Our results showed that ANR of C. carlesii forest reduced surface runoff and sediment yield up to 50% compared with other young plantations in the first 3 years and substantially increased plant diversity. ANR also reduced the export of dissolved organic carbon by 60–90% in the first 2 years. Aboveground biomass of the young ANR forest was approximately 3–4 times of that of other young plantations, while aboveground biomass of mature ANR forests was approximately 1.4 times of that of mature Chinese fir plantations of the same age. If all Chinese fir plantations in China were replaced by ANR forests, potentially 0.7 Pg more carbon will be stored in aboveground in one rotation (25 years). The results indicate that ANR triggers positive feedbacks among soil and water conservation, biodiversity protection, and biomass accumulation and thereby enhances ecosystem services