Results for “HoEr” | Engineering Papers

DOE OSTI2020

Materials Data on HoEr by Materials Project

ErHo is Magnesium-derived structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Er is bonded to six equivalent Er and six equivalent Ho atoms to form ErHo6Er6 cuboctahedra that share corners with eighteen equivalent ErHo6Er6 cuboctahedra, edges with six equivalent ErHo6Er6 cuboctahedra, edges with twelve equivalent HoHo6Er6 cuboctahedra, faces with eight equivalent ErHo6Er6 cuboctahedra, and faces with twelve equivalent HoHo6Er6 cuboctahedra. All Er–Er bond lengths are 3.57 Å. All Er–Ho bond lengths are 3.51 Å. Ho is bonded to six equivalent Er and six equivalent Ho atoms to form HoHo6Er6 cuboctahedra that share corners with eighteen equivalent HoHo6Er6 cuboctahedra, edges with six equivalent HoHo6Er6 cuboctahedra, edges with twelve equivalent ErHo6Er6 cuboctahedra, faces with eight equivalent HoHo6Er6 cuboctahedra, and faces with twelve equivalent ErHo6Er6 cuboctahedra. All Ho–Ho bond lengths are 3.57 Å.

36 MATERIALS SCIENCE↗

DOE OSTI2021

Carbonate-hosted microbial communities are prolific and pervasive methane oxidizers at geologically diverse marine methane seep sites

At marine methane seeps, vast quantities of methane move through the shallow subseafloor, where it is largely consumed by microbial communities. This process plays an important role in global methane dynamics, but we have yet to identify all of the methane sinks in the deep sea. Here, we conducted a continental-scale survey of seven geologically diverse seafloor seeps and found that carbonate rocks from all sites host methane-oxidizing microbial communities with substantial methanotrophic potential. In laboratory-based mesocosm incubations, chimney-like carbonates from the newly described Point Dume seep off the coast of Southern California exhibited the highest rates of anaerobic methane oxidation measured to date. After a thorough analysis of physicochemical, electrical, and biological factors, we attribute this substantial metabolic activity largely to higher cell density, mineral composition, kinetic parameters including an elevated V max , and the presence of specific microbial lineages. Our data also suggest that other features, such as electrical conductance, rock particle size, and microbial community alpha diversity, may influence a sample’s methanotrophic potential, but these factors did not demonstrate clear patterns with respect to methane oxidation rates. Based on the apparent pervasiveness within seep carbonates of microbial communities capable of performing anaerobic oxidation of methane, as well as the frequent occurrence of carbonates at seeps, we suggest that rock-hosted methanotrophy may be an important contributor to marine methane consumption.

58 GEOSCIENCES↗