Parrotfish chew on coral, producing hundreds of pounds of sand each year. Mapping the microstructure of parrotfish teeth, scientists found bundles of crystals interwoven like chain mail. The results provide a blueprint for creating ultra-durable materials for mechanical components that undergo repetitive contact, movement, and abrasion. ... Read more »
Researchers have discovered some good news regarding corals: the mechanism by which their exoskeletons grow may help them resist the effects of ocean acidification. The discovery, made with PEEM studies, has ramifications not only for the health of coral reefs, but for applications such as 3D printing as well.
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A parrotfish’s hardy teeth allow it to chomp on coral all day long, ultimately grinding it up through digestion into fine sand. Researchers wanting to see how the fine crystal structure of parrotfish teeth contribute to their incredible strength were able to visualize the orientation of individual crystals, which showed their intricately woven structure. ... Read more »
Skeletons of Stylophora pistillata corals form by the attachment of amorphous calcium carbonate precursor particles, formed within the coral tissue, to the coral skeleton surface. This mechanism is faster than the precipitation of ions from solution and may render the corals less susceptible to ocean acidification than previously assumed. ... Read more »
Researchers used x-ray microdiffraction to trace the complex sequences of crystal growth in concrete from ancient Roman pier and breakwater sites. The results indicate that minerals continue to form over millennia as seawater percolates through, reinforcing the cementing matrix in a kind of regenerative process. ... Read more »
A new look inside 2,000-year-old concrete—made from volcanic ash, lime (the product of baked limestone), and seawater—has provided new clues to the evolving chemistry and mineral cements that allow ancient harbor structures to withstand the test of time. ... Read more »
A small amount of compressive strain turns a nonmetallic form of tin into a 3D topological Dirac semimetal—a kind of “supermetal” with very high electron mobility. With its rich topological phase diagram, the material shows promise for both novel physics and eventual device applications.
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A group of scientists used Laue x-ray microdiffraction at the ALS to probe plastic deformation mechanisms at the nanoscale. Their findings may overturn conventional theory and reshape our understanding of the mechanical behavior of a host of nanocrystalline metals. ... Read more »
Researchers have shown that the thickness of the nacre, or mother-of-pearl, that lines the insides of mollusk shells can be used to estimate ocean temperatures as far back as the early Jurassic period. X-ray studies of modern and ancient shells help establish the method’s feasibility. ... Read more »
Laser 3D printing is a promising way to repair machine parts (such as jet-engine turbine blades) made of single-crystal superalloys. But microstructural inhomogeneities created by the high-power laser are a major reliability concern, so researchers employed x-ray Laue microdiffraction to probe the microstructure. ... Read more »