4 research outputs found
TRY plant trait database â enhanced coverage and open access
Plant traitsâthe morphological, anatomical, physiological, biochemical and phenological characteristics of plantsâdetermine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of traitâbased plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traitsâalmost complete coverage for âplant growth formâ. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and traitâenvironmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Improved mechanical and wear properties of H13 tool steel by nitrogen-expanded martensite using current-controlled plasma nitriding
Nitrogen-expanded martensite is a crystalline structure formed by incorporating nitrogen atoms into the interstitial sites of martensitic steels. It has recently gained significant industrial attention due to its excellent mechanical and wear-resistance properties. However, the major challenge in synthesizing nitrogen-expanded martensite is obtaining a phase free of iron or chromium nitrides precipitates. In this study, the effects of varying temperature (460, 480, and 500 °C) and plasma current density (0.5, 1.0, and 1.5 mA/cm2) during plasma nitriding of H13 tool steel were investigated to evaluate their influence on crystalline phases. The results of X-ray diffraction analysis indicate that expanded martensite free of nitride precipitates can be obtained at a temperature of 480 °C and low current density. Moreover, wear analysis using a ball-on-disk wear tester showed that the lowest wear rates were achieved under similar conditions. Grazing incidence X-ray diffraction analysis revealed that the outer region of the nitrided zone had a disordered structure, which could be attributed to a nano crystallization process. The nanoindentation analysis demonstrated that the expanded martensite phase has rigid-elastic properties characterized by high elastic energy (144.5 nJ) and high resistance to plastic deformation