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All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Close out the Critical Commitment for System Wide Safety’s Technical Challenge 3 (TC 3)

- Deliver validated methods and recommended practices to reduce certification costs for ground and onboard vehicle guidance and control systems through expanded acceptability of analysis as evidence for certification FY 2022. - Communicate results to maximize public awareness of the research and transfer capabilities via a set of on-demand training seminars and supporting materials including reports, publications and open source software codes where applicable.

Joseph C Coughlan↗
DOE OSTI2020

DOE Zero Energy Ready Home Case Study HIA 2020: TC Legend Homes, Everson Net Positive, Everson, WA

Case study of a DOE 2020 Housing Innovation Award winning custom home in a cold climate that got a HERS -19 with PV, with 2,538 square feet and a large south-facing roof, which is designed to hold over 80 solar panels, and the large south-facing windows, bringing in sunlight to warm the concrete floors and provide passive solar heating.

Building America, residential construction, home b↗
DOE OSTI2020

Materials Data on Tc6BiO18 by Materials Project

Tc6BiO18 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are twelve inequivalent Tc+5.50+ sites. In the first Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 30–41°. There are a spread of Tc–O bond distances ranging from 1.84–2.03 Å. In the second Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 31–54°. There are a spread of Tc–O bond distances ranging from 1.81–2.12 Å. In the third Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 28–52°. There are a spread of Tc–O bond distances ranging from 1.84–2.07 Å. In the fourth Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 30–52°. There are a spread of Tc–O bond distances ranging from 1.84–2.06 Å. In the fifth Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 30–53°. There are a spread of Tc–O bond distances ranging from 1.86–2.06 Å. In the sixth Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 28–52°. There are a spread of Tc–O bond distances ranging from 1.88–2.01 Å. In the seventh Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 31–52°. There are a spread of Tc–O bond distances ranging from 1.84–2.14 Å. In the eighth Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 31–38°. There are a spread of Tc–O bond distances ranging from 1.85–2.00 Å. In the ninth Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 30–53°. There are a spread of Tc–O bond distances ranging from 1.85–2.08 Å. In the tenth Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 25–53°. There are a spread of Tc–O bond distances ranging from 1.87–2.01 Å. In the eleventh Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 25–54°. There are a spread of Tc–O bond distances ranging from 1.83–2.09 Å. In the twelfth Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 30–53°. There are a spread of Tc–O bond distances ranging from 1.86–2.04 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Bi–O bond distances ranging from 2.16–2.97 Å. In the second Bi3+ site, Bi3+ is bonded in a distorted hexagonal planar geometry to six O2- atoms. There are a spread of Bi–O bond distances ranging from 2.19–2.87 Å. There are thirty-six inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Tc+5.50+ and one Bi3+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two Tc+5.50+ and one Bi3+ atom. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Tc+5.50+ and one Bi3+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the thirteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the fourteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Tc+5.50+ and one Bi3+ atom. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to two Tc+5.50+ and one Bi3+ atom. In the seventeenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Tc+5.50+ and one Bi3+ atom. In the eighteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the nineteenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Tc+5.50+ and one Bi3+ atom. In the twentieth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the twenty-first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Tc+5.50+ and one Bi3+ atom. In the twenty-second O2- site, O2- is bonded in a 2-coordinate geometry to two Tc+5.50+ and one Bi3+ atom. In the twenty-third O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the twenty-fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the twenty-fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the twenty-sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the twenty-seventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Tc+5.50+ and one Bi3+ atom. In the twenty-eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the twenty-ninth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the thirtieth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the thirty-first O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the thirty-second O2- site, O2- is bonded in a 3-coordinate geometry to two Tc+5.50+ and one Bi3+ atom. In the thirty-third O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the thirty-fourth O2- site, O2- is bonded in a 2-coordinate geometry to two Tc+5.50+ and one Bi3+ atom. In the thirty-fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the thirty-sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tc3Pd by Materials Project

Tc3Pd crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are seven inequivalent Tc+0.67- sites. In the first Tc+0.67- site, Tc+0.67- is bonded to nine Tc+0.67- and three equivalent Pd2+ atoms to form a mixture of edge, face, and corner-sharing TcTc9Pd3 cuboctahedra. There are three shorter (2.72 Å) and six longer (2.74 Å) Tc–Tc bond lengths. All Tc–Pd bond lengths are 2.81 Å. In the second Tc+0.67- site, Tc+0.67- is bonded to twelve Tc+0.67- atoms to form TcTc12 cuboctahedra that share corners with six equivalent TcTc12 cuboctahedra, edges with eighteen TcTc9Pd3 cuboctahedra, and faces with eighteen TcTc9Pd3 cuboctahedra. All Tc–Tc bond lengths are 2.74 Å. In the third Tc+0.67- site, Tc+0.67- is bonded to nine Tc+0.67- and three equivalent Pd2+ atoms to form a mixture of edge, face, and corner-sharing TcTc9Pd3 cuboctahedra. There are three shorter (2.72 Å) and six longer (2.74 Å) Tc–Tc bond lengths. All Tc–Pd bond lengths are 2.81 Å. In the fourth Tc+0.67- site, Tc+0.67- is bonded to sixteen Tc+0.67- atoms to form a mixture of edge, face, and corner-sharing TcTc16 cuboctahedra. There are a spread of Tc–Tc bond distances ranging from 2.72–5.48 Å. In the fifth Tc+0.67- site, Tc+0.67- is bonded to nine Tc+0.67- and three equivalent Pd2+ atoms to form TcTc9Pd3 cuboctahedra that share corners with seventeen TcTc9Pd3 cuboctahedra, edges with sixteen TcTc9Pd3 cuboctahedra, and faces with fifteen TcTc16 cuboctahedra. All Tc–Tc bond lengths are 2.74 Å. All Tc–Pd bond lengths are 2.81 Å. In the sixth Tc+0.67- site, Tc+0.67- is bonded to twelve Tc+0.67- atoms to form TcTc12 cuboctahedra that share corners with eleven TcTc13Pd3 cuboctahedra, edges with sixteen TcTc9Pd3 cuboctahedra, and faces with twenty-one TcTc13Pd3 cuboctahedra. There are six shorter (2.72 Å) and six longer (2.74 Å) Tc–Tc bond lengths. In the seventh Tc+0.67- site, Tc+0.67- is bonded to thirteen Tc+0.67- and three equivalent Pd2+ atoms to form TcTc13Pd3 cuboctahedra that share corners with seventeen TcTc9Pd3 cuboctahedra, edges with twenty TcTc9Pd3 cuboctahedra, and faces with twenty-five TcTc13Pd3 cuboctahedra. There are a spread of Tc–Tc bond distances ranging from 2.74–5.48 Å. All Tc–Pd bond lengths are 2.81 Å. There are two inequivalent Pd2+ sites. In the first Pd2+ site, Pd2+ is bonded in a 6-coordinate geometry to six equivalent Tc+0.67- atoms. In the second Pd2+ site, Pd2+ is bonded in a 6-coordinate geometry to six Tc+0.67- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zn7Tc by Materials Project

TcZn7 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Tc is bonded to twelve Zn atoms to form TcZn12 cuboctahedra that share corners with twelve equivalent TcZn12 cuboctahedra, edges with twenty-four ZnZn10Tc2 cuboctahedra, and faces with eighteen ZnZn10Tc2 cuboctahedra. All Tc–Zn bond lengths are 2.74 Å. There are twenty-five inequivalent Zn sites. In the first Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. All Zn–Zn bond lengths are 2.74 Å. In the second Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. All Zn–Zn bond lengths are 2.74 Å. In the third Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. All Zn–Zn bond lengths are 2.74 Å. In the fourth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn12 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. All Zn–Zn bond lengths are 2.74 Å. In the fifth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. All Zn–Zn bond lengths are 2.74 Å. In the sixth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. All Zn–Zn bond lengths are 2.74 Å. In the seventh Zn site, Zn is bonded to twelve Zn atoms to form ZnZn12 cuboctahedra that share corners with twelve equivalent ZnZn12 cuboctahedra, edges with twenty-four ZnZn10Tc2 cuboctahedra, faces with six equivalent TcZn12 cuboctahedra, and faces with twelve ZnZn10Tc2 cuboctahedra. All Zn–Zn bond lengths are 2.74 Å. In the eighth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. All Zn–Zn bond lengths are 2.74 Å. In the ninth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. All Zn–Zn bond lengths are 2.74 Å. In the tenth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn12 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. Both Zn–Tc bond lengths are 2.74 Å. All Zn–Zn bond lengths are 2.74 Å. In the eleventh Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. Both Zn–Tc bond lengths are 2.74 Å. All Zn–Zn bond lengths are 2.74 Å. In the twelfth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. Both Zn–Tc bond lengths are 2.74 Å. Both Zn–Zn bond lengths are 2.74 Å. In the thirteenth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. Both Zn–Tc bond lengths are 2.74 Å. Both Zn–Zn bond lengths are 2.74 Å. In the fourteenth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. Both Zn–Tc bond lengths are 2.74 Å. All Zn–Zn bond lengths are 2.74 Å. In the fifteenth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. Both Zn–Tc bond lengths are 2.74 Å. All Zn–Zn bond lengths are 2.74 Å. In the sixteenth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. All Zn–Zn bond lengths are 2.74 Å. In the seventeenth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. All Zn–Zn bond lengths are 2.74 Å. In the eighteenth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. Both Zn–Tc bond lengths are 2.74 Å. All Zn–Zn bond lengths are 2.74 Å. In the nineteenth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. Both Zn–Tc bond lengths are 2.74 Å. All Zn–Zn bond lengths are 2.74 Å. In the twentieth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. Both Zn–Tc bond lengths are 2.74 Å. All Zn–Zn bond lengths are 2.74 Å. In the twenty-first Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. Both Zn–Tc bond lengths are 2.74 Å. All Zn–Zn bond lengths are 2.74 Å. In the twenty-second Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn12 cuboctahedra. Both Zn–Tc bond lengths are 2.74 Å. All Zn–Zn bond lengths are 2.74 Å. In the twenty-third Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. Both Zn–Tc bond lengths are 2.74 Å. All Zn–Zn bond lengths are 2.74 Å. In the twenty-fourth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. Both Zn–Zn bond lengths are 2.74 Å. In the twenty-fifth Zn site, Zn is bonded to two equivalent Tc and ten Zn atoms to form ZnZn10Tc2 cuboctahedra that share corners with twelve ZnZn10Tc2 cuboctahedra, edges with four equivalent TcZn12 cuboctahedra, edges with twenty ZnZn10Tc2 cuboctahedra, faces with two equivalent TcZn12 cuboctahedra, and faces with sixteen ZnZn10Tc2 cuboctahedra. Both Zn–Zn bond lengths are 2.74 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Identification and Quantification of Technetium Species in Hanford Waste Tank AN-102

Technetium-99 (Tc) generated from the fission of 235U and 239Pu in high yields is one of the most difficult contaminants to be addressed at the U.S. Department of Energy Hanford Site. In strongly alkaline solutions typifying Hanford tank waste, Tc exists as pertechnetate (TcO4-) (oxidation state VII) as well as in reduced forms (oxidation state < VII) collectively known as non-pertechnetate species. Designing strategies for effective Tc management, including separation and immobilization, necessitates understanding the molecular structure of the non- pertechnetate species and their identification in the actual tank waste samples, which would facilitate development of new treatment technologies effective for dissimilar Tc species. Toward this objective, a spectroscopic library of the Tc(I) [fac-Tc(CO)3]+ and Tc(IV, VII) compounds was generated using a range of techniques and applied to the characterization of the actual tank waste supernatant collected from the tank 241-AN-102 at Hanford, WA. A sample of the 241-AN-102 tank waste supernatant was processed to adjust Na concentration to about 5.6 M and remove 137Cs by spherical resorcinol-formaldehyde (sRF) ion exchange resin. Cesium-loaded sRF column was eluted with 0.5 M HNO3. As received AN-102, Cs-depleted AN-102 effluent, and sRF eluate fractions were comprehensively characterized for chemical composition and speciation of Tc using 99Tc nuclear magnetic resonance spectroscopy and X-ray absorption spectroscopy. It was demonstrated for the first time that non-pertechnetate Tc present in the 241-AN-102 tank waste is composed of several low-valent Tc species, including the Tc(I) [fac-Tc(CO)3]+ and Tc(IV) compounds. This is the second experimental observation of the [fac-Tc(CO)3]+ species in the Hanford tank waste and the first demonstration of multiple forms of non-pertechnetate species existing simultaneously in the waste, cumulatively highlighting their importance for the waste processing.

Low Activity Waste (LAW), High Level Waste, nuclea↗
NASA NTRSDate not supplied

Generation of Continental Scale Percent Tree Cover Product Using Deep-learning and Multi-scale Remote Sensing Data

Spatially explicit percent tree cover (TC) estimation is critical for mapping forest aboveground biomass and its dynamics. While various TC products have been developed, there has not been a generalized framework that can be applied to diverse terrestrial ecosystems due to underlain extreme complexities. Deep learning algorithms can learn a spatial pattern and radiometric characteristics of tree canopy as a robust approximation of physical or empirical models, and thus have emerged as promising and efficient tools for large-scale TC mapping. In this study, we synergistically use very high-resolution aerial imageries (National Agriculture Imagery Program, NAIP) and medium resolution Landsat data to map continental-scale TC (CONUS and Mexico) through a hierarchical deep learning approach (Convolutional Neural Network), i.e., NAIP TC generated from a NAIP model is utilized to train a Landsat model. The produced TC product (hereafter, NEX-TC) is able to capture the spatial pattern of TC distribution and its changes driven by natural disturbance and human land management. We further explore and analyze the reliability and potential uncertainty of the NEX-TC by comparing it to lidar- (lidar-TC), National Land Cover Database (NLCD-TC), and MODIS Vegetation Continuous Field (MODIS-TC). This evaluation practice reveals that TC products based on passive optical sensors tend to underestimate TC across all land cover types while Landsat-based TCs (i.e., NEX-TC & NLCD-TC) perform better than the coarser MODIS TC estimate. Our results show that the NEX-TC is generally comparable to NLCD-TC but it particularly outperforms NLCD-TC and MODIS-TC over the dense forests where lidar-TC indicates >80% TC. These results indicate that our hierarchical deep learning approach and TC product will be effective and useful for characterizing large-scale tree cover and possibly associated carbon dynamics.

Landsat↗
DOE OSTI2020

Materials Data on Tc6BiO18 by Materials Project

Tc6BiO18 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are four inequivalent Tc+5.50+ sites. In the first Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 35–38°. There are a spread of Tc–O bond distances ranging from 1.87–1.95 Å. In the second Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 35–51°. There are a spread of Tc–O bond distances ranging from 1.85–2.00 Å. In the third Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 30–54°. There are a spread of Tc–O bond distances ranging from 1.86–2.02 Å. In the fourth Tc+5.50+ site, Tc+5.50+ is bonded to six O2- atoms to form corner-sharing TcO6 octahedra. The corner-sharing octahedra tilt angles range from 30–54°. There are a spread of Tc–O bond distances ranging from 1.87–2.05 Å. Bi3+ is bonded in a hexagonal planar geometry to six O2- atoms. There are a spread of Bi–O bond distances ranging from 2.42–2.45 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two Tc+5.50+ and one Bi3+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Tc+5.50+ atoms. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Tc+5.50+ and one Bi3+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Tc+5.50+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Tc+5.50+ and one Bi3+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Tc+5.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Structural Investigation of Technetium Dibutylphosphate Species Using X-ray Absorption Fine Structure Spectroscopy

The speciation of Tc after the extraction of Tc(IV) from H 2 O and 1 M HNO 3 by dibutylphosphoric acid (HDBP) in dodecane has been studied by X-ray absorption fine structure (XAFS) spectroscopy. Results show the formation of dimeric species with Tc 2 O 2 and Tc 2 O units, and the formulas [Tc 2 O 2 (DBP·HDBP) 4 ] (1) and [Tc 2 O(NO 3 ) 2 (DBP) 2 (DBP·HDBP) 2 ] (2) were, respectively, proposed for the species extracted from H 2 O and 1 M HNO 3 . The interatomic Tc–Tc distances found in the Tc 2 O 2 and Tc 2 O units [2.55(3) and 3.57(4) Å, respectively] are similar to the ones found in Tc(IV) dinuclear species. It is likely that the speciation of Tc(IV) in dodecane is due to the extraction of a species with a Tc 2 O unit for (2) and to the redissolution of a Tc(IV)-DBP solid for (1). The XAFS results for (1) and (2) were compared to that obtained for the extraction of Tc(IV) with TBP/HDBP/dodecane from 0.5 M HNO 3 , (3) which highlight the formation of Tc mononuclear nitrate species {i.e. [Tc(NO 3 ) 3 (DBP)] or [Tc(NO 3 ) 2 (DBP·HDBP)]}. These results confirm the importance of the preparation and speciation of the Tc(IV) aqueous solutions prior to extraction and how much this influences and drives the final Tc speciation in organic extraction. Here, these studies outline the complexity of Tc separation chemistry and provide insights into the behavior of Tc during the reprocessing of used nuclear fuel.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗