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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on TeC6(ClF7)2 by Materials Project

(CF2)2(CF3)2C2Te(ClF2)2 crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of eight difluoromethane molecules, eight fluoroform molecules, and four C2Te(ClF2)2 clusters. In each C2Te(ClF2)2 cluster, C3+ is bonded in a water-like geometry to one Te2- and two F1- atoms. The C–Te bond length is 2.34 Å. Both C–F bond lengths are 1.35 Å. Te2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent C3+ and two equivalent Cl1- atoms. Both Te–Cl bond lengths are 2.49 Å. Cl1- is bonded in a distorted single-bond geometry to one Te2- atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one C3+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one C3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AgH8C7S2O2F7 by Materials Project

AgC4H8(SO)2(CF2)2CF3 crystallizes in the orthorhombic Pca2_1 space group. The structure is two-dimensional and consists of eight difluoromethane molecules; four fluoroform molecules; and one AgC4H8(SO)2 sheet oriented in the (0, 0, 1) direction. In the AgC4H8(SO)2 sheet, Ag1+ is bonded to three S2- and one O2- atom to form distorted corner-sharing AgS3O tetrahedra. All Ag–S bond lengths are 2.62 Å. The Ag–O bond length is 2.35 Å. There are four inequivalent C+0.86+ sites. In the first C+0.86+ site, C+0.86+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.27 Å) C–O bond length. In the second C+0.86+ site, C+0.86+ is bonded in a trigonal non-coplanar geometry to three H1+ and one S2- atom. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. The C–S bond length is 1.81 Å. In the third C+0.86+ site, C+0.86+ is bonded in a trigonal non-coplanar geometry to three H1+ and one S2- atom. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. The C–S bond length is 1.82 Å. In the fourth C+0.86+ site, C+0.86+ is bonded in a distorted water-like geometry to two H1+ and two S2- atoms. Both C–H bond lengths are 1.10 Å. There is one shorter (1.81 Å) and one longer (1.83 Å) C–S bond length. There are eight inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Ag1+ and two C+0.86+ atoms to form distorted corner-sharing SAg2C2 tetrahedra. In the second S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to one Ag1+ and two C+0.86+ atoms. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Ag1+ and one C+0.86+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+0.86+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgH16C4S4N2(O4F3)4 by Materials Project

MgH4S4(NO4)2(CHF3)2(CF2)2(H2O)4(HF)2(O2)2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four difluoromethane molecules, four fluoroform molecules, four hydrofluoric acid molecules, four hydrogen peroxide molecules, eight water molecules, and two MgH4S4(NO4)2 clusters. In each MgH4S4(NO4)2 cluster, Mg2+ is bonded in a distorted linear geometry to two equivalent O2- atoms. Both Mg–O bond lengths are 1.91 Å. N5+ is bonded in a distorted trigonal planar geometry to one H1+, one S, and one O2- atom. The N–H bond length is 1.09 Å. The N–S bond length is 1.69 Å. The N–O bond length is 1.24 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one N5+ atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one S atom. The H–S bond length is 1.34 Å. There are two inequivalent S sites. In the first S site, S is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of S–O bond distances ranging from 1.49–1.57 Å. In the second S site, S is bonded in a 2-coordinate geometry to one N5+, one H1+, and one O2- atom. The S–O bond length is 2.41 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to one Mg2+ and one S atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two S atoms. In the third O2- site, O2- is bonded in a single-bond geometry to one S atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one N5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe2C9O7F4 by Materials Project

(Fe(CO)3)2CO(CF2)2 crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of eight difluoromethane molecules, four formaldehyde molecules, and eight Fe(CO)3 clusters. In four of the Fe(CO)3 clusters, Fe3+ is bonded in a 3-coordinate geometry to three C+1.33+ atoms. There is one shorter (1.80 Å) and two longer (1.82 Å) Fe–C bond length. There are two inequivalent C+1.33+ sites. In the first C+1.33+ site, C+1.33+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. In the second C+1.33+ site, C+1.33+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In four of the Fe(CO)3 clusters, Fe3+ is bonded in a 3-coordinate geometry to three C+1.33+ atoms. There is one shorter (1.80 Å) and two longer (1.82 Å) Fe–C bond length. There are two inequivalent C+1.33+ sites. In the first C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. In the second C+1.33+ site, C+1.33+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CIF5 by Materials Project

CF2(CIF5)2CIF4IF4 crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one difluoromethane molecule, one CIF4 cluster, two CIF5 clusters, and one IF4 cluster. In the CIF4 cluster, C is bonded in a water-like geometry to one I and two F atoms. The C–I bond length is 2.21 Å. There is one shorter (1.32 Å) and one longer (1.33 Å) C–F bond length. I is bonded in a distorted T-shaped geometry to one C and two F atoms. There are one shorter (2.00 Å) and one longer (2.02 Å) I–F bond lengths. There are four inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one I atom. In the second F site, F is bonded in a single-bond geometry to one I atom. In the third F site, F is bonded in a single-bond geometry to one C atom. In the fourth F site, F is bonded in a single-bond geometry to one C atom. In each CIF5 cluster, C is bonded in a trigonal non-coplanar geometry to one I and three F atoms. The C–I bond length is 2.22 Å. All C–F bond lengths are 1.34 Å. I is bonded in a distorted T-shaped geometry to one C and two F atoms. There are one shorter (2.01 Å) and one longer (2.04 Å) I–F bond lengths. There are five inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one C atom. In the second F site, F is bonded in a single-bond geometry to one I atom. In the third F site, F is bonded in a single-bond geometry to one C atom. In the fourth F site, F is bonded in a single-bond geometry to one C atom. In the fifth F site, F is bonded in a single-bond geometry to one I atom. In the IF4 cluster, I is bonded in a distorted rectangular see-saw-like geometry to four F atoms. There are a spread of I–F bond distances ranging from 1.95–1.97 Å. There are four inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one I atom. In the second F site, F is bonded in a single-bond geometry to one I atom. In the third F site, F is bonded in a single-bond geometry to one I atom. In the fourth F site, F is bonded in a single-bond geometry to one I atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgH16C4S4N2(O4F3)4 by Materials Project

MgH4S2(NO3)2(CF2)2(CH4O3F4)2(H2O)2(SO)2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four difluoromethane molecules, four sulfur monoxide molecules, four water molecules, four CH4O3F4 clusters, and two MgH4S2(NO3)2 clusters. In each CH4O3F4 cluster, C4+ is bonded in a tetrahedral geometry to one H1+ and three F1- atoms. The C–H bond length is 1.10 Å. There is two shorter (1.36 Å) and one longer (1.37 Å) C–F bond length. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a linear geometry to one O2- and one F1- atom. The H–O bond length is 1.35 Å. The H–F bond length is 1.04 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C4+ atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one O2- and one F1- atom. The O–O bond length is 1.23 Å. The O–F bond length is 2.98 Å. In the second O2- site, O2- is bonded in a distorted linear geometry to one O2- and one F1- atom. The O–F bond length is 2.80 Å. In the third O2- site, O2- is bonded in a trigonal non-coplanar geometry to three H1+ atoms. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one C4+ and one O2- atom. In the second F1- site, F1- is bonded in a single-bond geometry to one H1+ and one O2- atom. In the third F1- site, F1- is bonded in a single-bond geometry to one C4+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one C4+ atom. In each MgH4S2(NO3)2 cluster, Mg2+ is bonded in a square co-planar geometry to four O2- atoms. There are two shorter (2.02 Å) and two longer (2.19 Å) Mg–O bond lengths. N5+ is bonded in a bent 120 degrees geometry to one H1+ and one S atom. The N–H bond length is 1.05 Å. The N–S bond length is 1.55 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one N5+ atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one S atom. The H–S bond length is 1.38 Å. S is bonded in a trigonal non-coplanar geometry to one N5+, one H1+, and one O2- atom. The S–O bond length is 1.53 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to one Mg2+ and one S atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mg2+ and one O2- atom. The O–O bond length is 1.26 Å. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one O2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg(C2F3)2 by Materials Project

Hg(CF)2(CF2)2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two difluoromethane molecules and one Hg(CF)2 cluster. In the Hg(CF)2 cluster, Hg2+ is bonded in a distorted linear geometry to two equivalent C1+ atoms. Both Hg–C bond lengths are 2.09 Å. C1+ is bonded in a distorted single-bond geometry to one Hg2+ and one F1- atom. The C–F bond length is 1.38 Å. F1- is bonded in a single-bond geometry to one C1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C5F6 by Materials Project

(C)2(CF2)3 crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of forty-eight difluoromethane molecules and thirty-two medicinal charcoal molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3F5 by Materials Project

(CF2)2CF crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of sixteen difluoromethane molecules and eight fluoromethane molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CuC9S2NF10 by Materials Project

CuC5NS2(CF2)2(CF3)2 crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of eight difluoromethane molecules, eight fluoroform molecules, and four CuC5NS2 clusters. In each CuC5NS2 cluster, Cu1+ is bonded in a 4-coordinate geometry to two equivalent S2- atoms. Both Cu–S bond lengths are 2.32 Å. There are three inequivalent C+1.78+ sites. In the first C+1.78+ site, C+1.78+ is bonded in a single-bond geometry to one C+1.78+ and one N3- atom. The C–C bond length is 1.28 Å. The C–N bond length is 1.32 Å. In the second C+1.78+ site, C+1.78+ is bonded in a single-bond geometry to one C+1.78+ atom. In the third C+1.78+ site, C+1.78+ is bonded in a trigonal planar geometry to one N3- and two equivalent S2- atoms. The C–N bond length is 1.50 Å. Both C–S bond lengths are 1.66 Å. N3- is bonded in a trigonal planar geometry to three C+1.78+ atoms. S2- is bonded in a 2-coordinate geometry to one Cu1+ and one C+1.78+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on C3F5 by Materials Project

(CF2)2CF crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of sixteen difluoromethane molecules and eight fluoromethane molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AsC3S3NF10 by Materials Project

CAsNS3F6(CF2)2 crystallizes in the monoclinic P2_1/c space group. The structure is one-dimensional and consists of eight difluoromethane molecules and two CAsNS3F6 ribbons oriented in the (0, 1, 0) direction. In each CAsNS3F6 ribbon, C4+ is bonded in a distorted single-bond geometry to one N1- and one S2- atom. The C–N bond length is 1.29 Å. The C–S bond length is 1.75 Å. As5+ is bonded in an octahedral geometry to six F1- atoms. There are a spread of As–F bond distances ranging from 1.76–1.82 Å. N1- is bonded in a distorted bent 120 degrees geometry to one C4+ and one S2- atom. The N–S bond length is 1.60 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a single-bond geometry to one N1- and one S2- atom. The S–S bond length is 2.12 Å. In the second S2- site, S2- is bonded in a 1-coordinate geometry to two S2- and three F1- atoms. The S–S bond length is 2.04 Å. There are a spread of S–F bond distances ranging from 2.68–3.28 Å. In the third S2- site, S2- is bonded in a 1-coordinate geometry to one C4+ and one S2- atom. There are six inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one As5+ atom. In the second F1- site, F1- is bonded in a distorted single-bond geometry to one As5+ and one S2- atom. In the third F1- site, F1- is bonded in a single-bond geometry to one As5+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one As5+ and one S2- atom. In the fifth F1- site, F1- is bonded in a single-bond geometry to one As5+ atom. In the sixth F1- site, F1- is bonded in a single-bond geometry to one As5+ and one S2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgH16C4S4N2(O4F3)4 by Materials Project

MgN2H10S4(O5F)2(CHF3)2(CF2)2(H2O)2(O2)2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four difluoromethane molecules, four fluoroform molecules, four hydrogen peroxide molecules, four water molecules, and two MgN2H10S4(O5F)2 clusters. In each MgN2H10S4(O5F)2 cluster, Mg2+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are two shorter (1.99 Å) and two longer (2.05 Å) Mg–O bond lengths. N5+ is bonded in a trigonal planar geometry to one H1+, one S, and one O2- atom. The N–H bond length is 1.44 Å. The N–S bond length is 1.70 Å. The N–O bond length is 1.22 Å. There are five inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a distorted single-bond geometry to one O2- and one F1- atom. The H–O bond length is 1.00 Å. The H–F bond length is 1.58 Å. In the second H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.03 Å) and one longer (1.59 Å) H–O bond length. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fourth H1+ site, H1+ is bonded in a linear geometry to one N5+ and one F1- atom. The H–F bond length is 1.04 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one S atom. The H–S bond length is 1.36 Å. There are two inequivalent S sites. In the first S site, S is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of S–O bond distances ranging from 1.46–1.81 Å. In the second S site, S is bonded in a distorted water-like geometry to one N5+ and one H1+ atom. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to one Mg2+ and one S atom. In the second O2- site, O2- is bonded in a distorted water-like geometry to three H1+ atoms. In the third O2- site, O2- is bonded in a single-bond geometry to one S atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Mg2+, one H1+, and one S atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one N5+ atom. F1- is bonded in a distorted single-bond geometry to two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on GeC4(BrF5)2 by Materials Project

GeBr2(CF2)2(CF3)2 crystallizes in the tetragonal P4_32_12 space group. The structure is zero-dimensional and consists of four dibromogermane molecules, eight difluoromethane molecules, and eight fluoroform molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2021

AmeriFlux FLUXNET-1F US-CF1 CAF-LTAR Cook East

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-CF1 CAF-LTAR Cook East. This is the FLUXNET version of the carbon flux data for the site US-CF1 CAF-LTAR Cook East produced by applying the standard ONEFlux (1F) software. Site Description - CF1 has operated since May 2017 at the R.J. Cook Agronomy Farm outside of Pullman, Washington, and monitors the no-till side of a paired-catchment study that is part of the Longterm Agroecosystem Research (LTAR) site common experiment. CF1 is located in “Cook East,” a field that has been in no-till management since 1998, and represents the Alternative treatment of the LTAR common experiment. It is paired with the CF2 tower location in “Cook West,” which has been in conventional tillage since prior to 1998 and represents the Prevalent treatments of the common experiment. Cook Agronomy Farm is in the high precipitation agroecological zone of the Columbia Plateau’s dryland cropping region. Crop rotations are wheat-based and include winter wheat, spring wheat, chickpea, spring canola, and winter peas. Wheat is the principal cash crop, with other crops grown in rotation for diversity, nutrient, and pest management. Soils are predominantly silt loam texture Mollisols in the Palouse, Thatuna, Naff soil series. The CF1 tower replaced US-RC1, which operated 2012-2016 in a neighboring field that was also in no-till management since 1998. CF1 and RC1 have distinct footprints, aspects, and soil series compositions.

Phillips, Claire L.↗
DOE OSTI2026

AmeriFlux FLUXNET-1F US-RC2 Cook Agronomy Farm - Conventional Till

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-RC2 Cook Agronomy Farm - Conventional Till. This is the FLUXNET version of the carbon flux data for the site US-RC2 Cook Agronomy Farm - Conventional Till produced by applying the standard ONEFlux (1F) software. Site Description - RC2 operated from 2013-2016 at the R.J. Cook Agronomy Farm, as part of a cluster of 5 towers (RC1 to RC5) operated for the Regional Approaches to Climate Change (REACCH) USDA-supported research project. The tower predates the Longterm Agroecosystem Research (LTAR) site common experiment, which was established in nearby fields at the Cook Agronomy Farm in 2017. Cook Agronomy Farm is in the high-precipitation agroecological zone of the Columbia Plateau’s dryland cropping region. Wheat-based crop rotations are grown annually. RC2 had conventional tillage management (reduced-till) since at least 1998. It was contrasted with RC1, which had no-till management over the same time period. RC2 captured the same tillage practices as the US-CF2 site established in 2017 as part of LTAR common experiment. However, the towers have distinct footprints, aspects, and soil series composition.

Chi, Jinshu [The Hong Kong University of Science a↗
DOE OSTI2025

PFAS Removal by Ion Exchange Resins: Background and Knowledge Gaps with Respect to the Hanford Site

Per- and polyfluoroalkyl substances (PFAS) have been a rising concern for the past two decades, with the United States Department of Defense and Environmental Protection Agency investing millions of dollars in research into remediation and clean-up technologies. Due to the environmental persistence, toxicity, biological uptake, and ongoing changes in both federal and state regulatory space, understanding the fate and transport of PFAS compounds has been of growing concern to the US Department of Energy (DOE). The DOE’s Hanford Site is investigating historical use of PFAS and will be doing site characterization for PFAS. Thus, PFAS have not yet been identified as a contaminant concern in regulatory documents. Based on historical records that mention the discharge of aqueous film-forming foam containing PFAS and having on-site fire stations (a risk factor for PFAS contamination), it seems likely that environmental releases of PFAS may have occurred. Pump and treat (P&T) remediation is the selected remedy for multiple groundwater contaminant plumes at Hanford. These P&T systems use ion exchange (IX) as a component of aboveground treatment, with the specific resins depending on the target contaminants. There is potential that these IX resins may be able to remove PFAS from groundwater, but investigation is needed to understand affinity/selectivity and removal capacity given the groundwater composition and the operating conditions. This report provides background on PFAS uses and chemistry, then provides a review of IX resin applications for PFAS, identifying knowledge gaps. Recommendations are provided regarding research needed to address knowledge gaps and acquire information needed to propose IX as a future PFAS remediation technology at the Hanford Site, as well as other U.S. Department of Energy sites. Generally, PFAS compounds are fluorinated substances that contain at least one fully fluorinated methyl or methylene carbon – with a few noted exceptions, any chemical with at least a perfluorinated methyl group (–CF3) or a perfluorinated methylene group (–CF2–) is a PFAS. These chemical compounds are characterized as non-biodegradable, non-reactive, non-photolytic, and hydrolysis resistant. This makes them highly recalcitrant within the environment, however polyfluoroalkyl materials are less recalcitrant as the carbon chains contain C–H bonds which are more easily broken than carbon – fluorine (C–F) bonds. The backbone carbon structures are commonly punctuated with a head group, the most well-known of them are perfluorooctanesulfonic acid and perfluorooctanoic acid, which possess a sulfonate and a carboxylate group, respectively. IX resins are marketed for the removal of PFAS from water systems and industrial water, however, the mechanism of removal is not as well understood as for anion or cation removal. A better understanding of the mechanism of removal would enable the development of IX resins that have improved specificity for PFAS removal. Four knowledge gaps were identified: 1) the effect of dissolved ions on the IX resin PFAS removal effectiveness, 2) the effect of additional primary contaminants of concern (PCOCs) or secondary contaminants of concern (SCOCs) on the effectiveness of PFAS via IX resin, 3) the mechanisms of PFAS removal from water, and 4) practical solutions to IX resin regeneration and waste disposal.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS1988

Mixing ratios of trace gases in the austral polar atmosphere during August and September of 1987

Mixing ratios are presented for a number of long-lived trace gases in the austral polar atmosphere during August and September of 1987. The recent discovery of a 12-year trend of increasing depletion of ozone over the Antarctic Continent in the spring of each year led to numerous theoretical interpretations and several scientific expeditions to the region. The results herein were obtained as part of a major effort involving penetration of the region of ozone depletion by NASA's multi-instrumented aircraft. One of the 14 instruments on the high-altitude ER-2 aircraft collected pressurized air samples between latitudes of 53 degrees and 72 degrees south at pressure altitudes up to 21 km in a series of 12 flights from Punta Arenas, Chile, over the Palmer Peninsula. The sampling system, located in the nose section of ER-2, has an inlet tube in the free airstream, a metal-bellows air pump, and 14 specially treated 1.6 l stainless-steel canisters for containing the pressurized air at 350 kPa. A typical flight profile consisted of a southbound path on the 428 K potential temperature surface, a descent to a pressure altitude of 13.7 km, a climb to the 460 K surface, and return on this surface. Mixing ratios for the trace gases were obtained from gas chromatographic analyses of the pressurized air samples. Of the species measured, the mixing ratios for CH4, CO, N2O, CF2 Cl2, CFCl3, CH3, CCl3, CCl4, and C2F3Cl3 are reported here.

Vedder, James F.↗