Additive manufacturing of Oxide Dispersion Strengthened (ODS) alloys

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Advanced titanium scaffolds obtained by directional freeze-drying: on the influence of processing conditions

Ministry of Science and Innovation of Spain under Grant No. MAT2010-20855Junta de Andalucía (Spain) / FEDER (EU), through the project Ref. P12-TEP-140

An evaluation of sampling methodology for assessing settlement of temperate fish in seagrass meadows

All demersal fish with planktonic larvae settle at some point early in life, generally around the transformation from larvae to juveniles or soon after. Sampling pre-settlement or very young, settled fish is challenging due to spatial concretions within the habitat and the pulsed, rapid nature of the settlement process. There is a lack of robust methods that enable this sampling, but information on the settlement, that represents a mortality bottleneck, is crucial for the follow-up of populations for fisheries and conservation purposes. An empirical evaluation of sampling methods has not been conducted in temperate habitats. Here, we compare six different sampling methods to collect pre- and post-settlement stages of fish to determine the best combination of techniques to utilise in Posidonia oceanica, an endemic Mediterranean seagrass that provides a key nursery habitat for coastal fish. We considered three types of pelagic nets (bongo net, neuston net and ring net), two types of light-traps (Quatrefoil and Ecocean CARE®) to sample pre-settled stages and a low-impact epibenthic trawl for recent settlers. Our results show a significantly different size-spectrum for each method, with a continuous range of sizes from 2 mm to 200 mm. The smallest sizes were collected by the bongo net, followed by the ring net, the neuston net, the Quatrefoil, the Ecocean and finally the epibenthic trawl. Our results suggest that an appropriate strategy for collecting and estimating the abundance of key littoral fish species around settlement size is the combination of the Ecocean light trap and the epibenthic trawl

PeroxiBase: a database with new tools for peroxidase family classification

Peroxidases (EC 1.11.1.x), which are encoded by small or large multigenic families, are involved in several important physiological and developmental processes. They use various peroxides as electron acceptors to catalyse a number of oxidative reactions and are present in almost all living organisms. We have created a peroxidase database (http://peroxibase.isb-sib.ch) that contains all identified peroxidase-encoding sequences (about 6000 sequences in 940 organisms). They are distributed between 11 superfamilies and about 60 subfamilies. All the sequences have been individually annotated and checked. PeroxiBase can be consulted using six major interlink sections ‘Classes', ‘Organisms', ‘Cellular localisations', ‘Inducers', ‘Repressors' and ‘Tissue types'. General documentation on peroxidases and PeroxiBase is accessible in the ‘Documents' section containing ‘Introduction', ‘Class description', ‘Publications' and ‘Links'. In addition to the database, we have developed a tool to classify peroxidases based on the PROSITE profile methodology. To improve their specificity and to prevent overlaps between closely related subfamilies the profiles were built using a new strategy based on the silencing of residues. This new profile construction method and its discriminatory capacity have been tested and validated using the different peroxidase families and subfamilies present in the database. The peroxidase classification tool called PeroxiScan is accessible at the following address: http://peroxibase.isb-sib.ch/peroxiscan.ph

Stress-induced martensitic transformations in NiTi and NiTi-TiC composites investigated by neutron diffraction

Superelastic NiTi (51.0 at% Ni) with 0, 10 and 20 vol% TiC particles were deformed under uniaxial compression as neutron diffraction spectra were simultaneously obtained. The experiments yielded in-situ measurements of the thermoelastic stress-induced transformation. A detailed Rietveld determination is made of the phase fractions and the evolving strains in the reinforcing TiC particles and the austenite as it transforms to martensite on loading (and its subsequent back transformation on unloading). These strains are used to shed light on the phenomenon of load transfer in composites where the matrix undergoes a stress-induced phase transformation

Metal grids with high-porous surface as structured catalysts: preparation, characterization and activity in propane total oxidation

Metal nickel and copper grids are shown to be suitable supports for structured combustion catalysts. The increase of sp. surface area (SSA) of metal grids was achieved due to the porous outer layer with the structure of Raney metal developed on the wire surface. Transition metals (Co, Cu, Mn, Cr) oxides were deposited as active components on the pre-oxidized support and tested in total propane oxidn. Cobalt oxide demonstrated the highest activity. Reductive pre-treatment in the flow of hydrogen resulted in a more active catalyst than the activation in oxygen atm. This effect was assigned to the partial redn. of Co3O4 until metallic Co, which was detected by XPS on the catalyst surface. Deactivation of the pre-reduced Co-oxide catalyst was obsd. during propane combustion in excess of oxygen and was ascribed to the oxidn. of partially reduced active phase. After 4 h on stream, the catalyst reached his steady-state and showed stable activity without further deactivation. The catalytic activity expressed in the terms of propane conversion was obsd. to depend on the propane/oxygen ratio. [on SciFinder (R)