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At least 865 records · Page 48
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on CuAg5As3O11 by Materials Project

Ag5CuAs3O11 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are five inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 5-coordinate geometry to six O2- atoms. There are a spread of Ag–O bond distances ranging from 2.40–2.99 Å. In the second Ag1+ site, Ag1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Ag–O bond distances ranging from 2.32–2.70 Å. In the third Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Ag–O bond distances ranging from 2.30–2.62 Å. In the fourth Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to six O2- atoms. There are a spread of Ag–O bond distances ranging from 2.41–3.04 Å. In the fifth Ag1+ site, Ag1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Ag–O bond distances ranging from 2.39–2.54 Å. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to six O2- atoms to form distorted CuO6 octahedra that share corners with six AsO4 tetrahedra. There are a spread of Cu–O bond distances ranging from 1.96–2.60 Å. In the second Cu2+ site, Cu2+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.95 Å) and two longer (1.97 Å) Cu–O bond length. There are three inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share a cornercorner with one CuO6 octahedra and a cornercorner with one AsO4 tetrahedra. The corner-sharing octahedral tilt angles are 54°. There are a spread of As–O bond distances ranging from 1.70–1.82 Å. In the second As5+ site, As5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of As–O bond distances ranging from 1.72–1.76 Å. In the third As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two equivalent CuO6 octahedra and a cornercorner with one AsO4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of As–O bond distances ranging from 1.70–1.81 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded to three Ag1+ and one As5+ atom to form distorted corner-sharing OAg3As tetrahedra. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two Ag1+, one Cu2+, and one As5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Ag1+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ag1+, one Cu2+, and one As5+ atom. In the fifth O2- site, O2- is bonded to two Ag1+, one Cu2+, and one As5+ atom to form distorted corner-sharing OCuAg2As tetrahedra. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Ag1+ and two As5+ atoms. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to four Ag1+ and one As5+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to three Ag1+ and one As5+ atom. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to three Ag1+ and one As5+ atom. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to two Ag1+, one Cu2+, and one As5+ atom. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to one Ag1+, one Cu2+, and one As5+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS2000

Independent controls for neocortical neuron production and histogenetic cell death

We estimated the proportion of cells eliminated by histogenetic cell death during the first 2 postnatal weeks in areas 1, 3 and 40 of the mouse parietal neocortex. For each layer and for the subcortical white matter in each neocortical area, the number of dying cells per mm(2) was calculated and the proportionate cell death for each day of the 2-week interval was estimated. The data show that cell death proceeds essentially uniformly across the neocortical areas and layers and that it does not follow either the spatiotemporal gradient of cell cycle progression in the pseudostratified ventricular epithelium of the cerebral wall, the source of neocortical neurons, or the 'inside-out' neocortical neuronogenetic sequence. Therefore, we infer that the control mechanisms of neocortical histogenetic cell death are independent of mechanisms controlling neuronogenesis or neuronal migration but may be associated with the ingrowth, expansion and a system-wide matching of neuronal connectivity. Copyright 2000 S. Karger AG, Basel.

NASA Discipline Cell Biology↗
DOE OSTI2020

Materials Data on AgMo3P3O16 by Materials Project

Mo3AgP3O16 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are three inequivalent Mo+5.33+ sites. In the first Mo+5.33+ site, Mo+5.33+ is bonded to six O2- atoms to form distorted MoO6 octahedra that share corners with five PO4 tetrahedra. There are a spread of Mo–O bond distances ranging from 1.70–2.27 Å. In the second Mo+5.33+ site, Mo+5.33+ is bonded to five O2- atoms to form MoO5 trigonal bipyramids that share a cornercorner with one MoO6 octahedra and corners with three PO4 tetrahedra. The corner-sharing octahedral tilt angles are 36°. There are a spread of Mo–O bond distances ranging from 1.70–2.05 Å. In the third Mo+5.33+ site, Mo+5.33+ is bonded to six O2- atoms to form distorted MoO6 octahedra that share corners with four PO4 tetrahedra and a cornercorner with one MoO5 trigonal bipyramid. There are a spread of Mo–O bond distances ranging from 1.71–2.33 Å. Ag1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ag–O bond distances ranging from 2.40–2.73 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three MoO6 octahedra and a cornercorner with one MoO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 34–46°. There are a spread of P–O bond distances ranging from 1.54–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four MoO6 octahedra. The corner-sharing octahedra tilt angles range from 19–50°. There are a spread of P–O bond distances ranging from 1.53–1.56 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent MoO6 octahedra and corners with two equivalent MoO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 37–40°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mo+5.33+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mo+5.33+ and one P5+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Mo+5.33+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mo+5.33+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mo+5.33+ and one Ag1+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mo+5.33+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Mo+5.33+ atoms. In the eighth O2- site, O2- is bonded in a single-bond geometry to one Mo+5.33+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mo+5.33+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to one Mo+5.33+, one Ag1+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mo+5.33+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to one Mo+5.33+, one Ag1+, and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted single-bond geometry to one Mo+5.33+, one Ag1+, and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a single-bond geometry to one Mo+5.33+ atom. In the fifteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Mo+5.33+, one Ag1+, and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Mo+5.33+, one Ag1+, and one P5+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS2010

Development of Gradient Compression Garments for Protection Against Post Flight Orthostatic Intolerance

Orthostatic intolerance after space flight is still an issue for astronaut health. No in-flight countermeasure has been 100% effective to date. NASA currently uses an inflatable anti-gravity suit (AGS) during reentry, but this device is uncomfortable and loses effectiveness upon egress from the Shuttle. The Russian Space Agency currently uses a mechanical counter-pressure garment (Kentavr) that is difficult to adjust alone, and prolonged use may result in painful swelling at points where the garment is not continuous (feet, knees, and groin). To improve comfort, reduce upmass and stowage requirements, and control fabrication and maintenance costs, we have been evaluating a variety of gradient compression, mechanical counter-pressure garments, constructed from spandex and nylon, as a possible replacement for the current AGS. We have examined comfort and cardiovascular responses to knee-high garments in normovolemic subjects; thigh-high garments in hypovolemic subjects and in astronauts after space flight; and 1-piece, breast-high garments in hypovolemic subjects. These gradient compression garments provide 55 mmHg of compression over the ankle, decreasing linearly to ~35 mmHg at the knee. In thigh-high versions the compression continues to decrease to ~20 mmHg at the top of the leg, and for breast-high versions, to ~15 mmHg over the abdomen. Measures of efficacy include increased tilt survival time, elevated blood pressure and stroke volume, and lower heart-rate response to orthostatic stress. Results from these studies indicate that the greater the magnitude of compression and the greater the area of coverage, the more effective the compression garment becomes. Therefore, we are currently testing a 3-piece breast-high compression garment on astronauts after short-duration flight. We chose a 3-piece garment consisting of thigh-high stockings and shorts, because it is easy to don and comfortable to wear, and should provide the same level of protection as the 1-piece breast-high garments evaluated in hypovolemic test subjects.

Stenger, M. B.↗
DOE OSTI2022

Potential Biocontrol Activities of Populus Endophytes against Several Plant Pathogens Using Different Inhibitory Mechanisms

The plant microbiome can be used to bolster plant defense against abiotic and biotic stresses. Some strains of endophytes, the microorganisms within plants, can directly inhibit the growth of plant fungal pathogens. A previously isolated endophyte from wild Populus (poplar), WPB of the species Burkholderia vietnamiensis, had robust in vitro antifungal activity against pathogen strains that are highly virulent and of concern to Pacific Northwest agriculture: Rhizoctonia solani AG-8, Fusarium culmorum 70110023, and Gaemannomyces graminis var. tritici (Ggt) ARS-A1, as well as activity against the oomycete, Pythium ultimum 217. A direct screening method was developed for isolation of additional anti-fungal endophytes from wild poplar extracts. By challenging pathogens directly with dilute extracts, eleven isolates were found to be inhibitory to at least two plant pathogen strains and were therefore chosen for further characterization. Genomic analysis was conducted to determine if these endophyte strains harbored genes known to be involved in antimicrobial activities. The newly isolated Bacillus strains had gene clusters for production of bacillomycin, fengicyn, and bacillibactin, while the gene cluster for the synthesis of sessilin, viscosin and tolaasin were found in the Pseudomonas strains. The biosynthesis gene cluster for occidiofungin (ocf) was present in the Burkholderia vietnamiensis WPB genome, and an ocf deletion mutant lost inhibitory activity against 3 of the 4 pathogens. The new isolates lacked the gene cluster for occidiofungin implying they employ different modes of action. Other symbiotic traits including nitrogen fixation, phosphate solubilization, and the production of auxins and siderophores were investigated. Although it will be necessary to conduct in vivo tests of the candidates with pathogen-infected agricultural crops, the wild poplar tree microbiome may be a rich source of beneficial endophyte strains with potential for biocontrol applications against a variety of pathogens and utilizing varying modes of action.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS2006

Carbon-Nanotube-Carpet Heat-Transfer Pads

Microscopic thermal-contact pads that include carpet-like arrays of carbon nanotubes have been invented for dissipating heat generated in integrated circuits and similarly sized single electronic components. The need for these or other innovative thermal-contact pads arises because the requisite high thermal conductances cannot be realized by scaling conventional macroscopic thermal-contact pads down to microscopic sizes. Overcoming limitations of conventional thermal-contact materials and components, the carbon-nanotube thermal-contact pads offer the high thermal conductivities needed to accommodate the high local thermal power densities of modern electronic circuits, without need for large clamping pressures, extreme smoothness of surfaces in contact, or gap-filling materials (e.g., thermally conductive greases) to ensure adequate thermal contact. Moreover, unlike some conventional thermal-contact components, these pads are reusable. The figure depicts a typical pad according to the invention, in contact with a rough surface on an electronic component that is to be cooled. Through reversible bending and buckling of carbon nanotubes at asperities on the rough surface, the pad yields sufficiently, under relatively low contact pressure, that thermal contact is distributed to many locations on the surface to be cooled, including valleys where contact would not ordinarily occur in conventional clamping of rigid surfaces. Hence, the effective thermal-contact area is greater than that achievable through scaling down of a macroscopic thermal-contact pad. The extremely high longitudinal thermal conductivities of the carbon nanotubes are utilized to conduct heat away from potential hot spots on the surface to be cooled. The fibers protrude from a layer of a filler material (Cu, Ag, Au, or metal-particle- filled gels), which provides both mechanical support to maintain the carbon nanotubes in alignment and thermal conductivity to enhance the diffusion of concentrated heat from the nanotubes into the larger adjacent volume of a heat sink. The array of carbon nanotubes, the filler material, and the heat sink are parts of a unitary composite structure that is fabricated as follows: 1. Using techniques that have been reported previously, the array of substantially perpendicularly oriented carbon nanotubes is grown on a metal, silicon, or other suitable thermally conductive substrate that is intended to become the heat sink. 2. By means of chemical vapor deposition, physical vapor deposition, plasma deposition, ion sputtering, electrochemical deposition, or casting from a liquid phase, some or all of the interstitial volume between carbon nanotubes is filled with the aforementioned layer of mechanically supporting, thermally conductive material. 3. To cause the carbon nanotubes to protrude the desired length from the filler material, an outer layer of filler is removed by mechanical polishing, chemical mechanical polishing, wet chemical etching, electrochemical etching, or dry plasma etching.

Li, Jun↗
DOE OSTI2022

Effect of silver($\mathrm{I}$) ion reduction on the selectivity of olefins, paraffins, and aromatic compounds by gas chromatographic stationary phases consisting of silver($\mathrm{I}$) salts in ionic liquids

We report the olefin/paraffin selectivity offered by ionic liquid (IL) stationary phases can be enhanced through the addition of silver(I) ion, which is well-known to undergo selective complexation with unsaturated compounds. However, such stationary phases often suffer from the loss of chromatographic selectivity as silver(I) ion can be reduced to elemental silver. To maintain the separation performance of silver(I) ion/IL stationary phases, an understanding of factors and conditions that promote the reduction of silver(I) ion is needed. In this study, capillary gas chromatography columns featuring a stationary phase consisting of the 1-decyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C 10 MIM + ][NTf 2 - ]) IL impregnated with [Ag + ][NTf 2 - ] were examined to investigate the effects of temperature, hydrogen content in exposure gas stream, and time of heating/exposure events on olefin selectivity. Retention factors of representative analytes, such as C 6 olefins and paraffins as well as aromatic compounds, were measured after subjecting the columns to the aforementioned conditions, followed by an evaluation of selectivity factors over time. Selectivity factors of olefins and aromatic compounds were observed to decrease significantly when the stationary phases were heated to temperatures higher than 110°C as well as being subjected to mixed gas streams containing greater than 50 mol% of hydrogen. As constant column heating temperatures were applied under exposure gas mixtures containing hydrogen and nitrogen, a gradual decrease in analyte selectivity factors was observed under prolonged periods of time. However, application of a ternary gas mixture comprised of 25/50/25 mol% hydrogen/nitrogen/methane resulted in an increase in the 3-hexyne/cis-2-hexene selectivity when measured at 120°C for 60 h, due to a smaller decrease in the retention factor of 3-hexyne compared to cis-2-hexene.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRSDate not supplied

X-Ray Computed Tomography During Preliminary Examination of Apollo Drive Tube 73001

Introduction: Starting in 2019, the Apollo Next Generation Sample Analysis (ANGSA) Program has enabled consortium studies of specially curated Apollo samples that were previously unstudied (or under studied). This began with unsealed core tube 73002 [1,2] that is the upper part of a station 3 double drive tube. More recently the pro-gram extended to the study of a variety of frozen Apollo 17 samples [3], as well as the gas extraction [4] and dis-section [5] of 73001, the lower half of the station 3 double drive tube, that was sealed under vacuum on the Moon. In this abstract we will examine the role of X-ray Computed Tomography (XCT) during the preliminary examination process for sealed core 73001, including: (1) engineering scans to aid in understanding the gas extraction process, whole-core scanning prior to opening to inform extrusion and dissection work, and (3) individual particle scanning to characterize rock fragment lithologies for follow on studies. Methodology: Sample 73001 is a 33 cm long, 4 cm diameter regolith sample collected inside a drive tube (~1 mm aluminum walls). That drive tube was sealed inside a 0.5 mm thick stainless steel (SS) Core Sample Vacuum Container (CSVC). XCT scans for engineering purposes were done on the Nikon XTH 320 system at Johnson Space Center using the 225 kV multi-metal reflection source at 215 kV, 179 A, and a 38.49 m voxel size. Individual >4 mm particles separated from the core during processing (then triply sealed in Teflon bags) were also scanned at JSC using the 180 kV source at 90 kV, 33 A, and a 2.98 – 10.65 m voxel size. Whole-core scans were done at the University of Texas High-Resolution X-ray Computed Tomography Facility (UTCT) on the 225 kV reflection source on the North Star Imaging cabinet XCT system. These scans included: (1) a series of 9 overlapping super-resolution scans each covering a ~4 cm length of the tube at 190 kV, 180 µA, and a 12.9 µm voxel size and (2) a lower resolution continuous helical scan of the entire core at 190 kV, 180 µA, and a 51.8 µm voxel size. Progress and Results: Before piercing and extracting the gas from sample 73001, an XCT scan of the bottom portion of the CSVC was used to confirm the location of the Teflon cap on the inner drive tube, to ensure it was not accidentally pierced during gas extraction. Similarly, after piercing, the bottom and top portions of the CSVC were scanned in order to capture engineering knowledge about the results of the piercing process, as well as the metal knife edge vacuum seal (SS into In-Ag alloy). Both scans will provide constraints on future work of this type, particularly for samples collected during the Artemis mission. Another finding from these "engineering" scans was that the device in the drive tube that immobilizes the regolith (the keeper) was not seated in the tube properly. This meant that (1) the drive tube could not be removed from the CSVC for the trip to UTCT, and (2) the procedure for opening and extruding the drive tube had to be modified. Had either of these things not been known prior to opening the CSVC, it could have led to an inability to XCT scan the whole core at high resolution and/or potential disruption of the core stratigraphy during extrusion. At UTCT, the entire length of the core was scanned at high resolution (12.9 microns per voxel). This scan serves multiple purposes: (1) A lower resolution (and uncorrected) version of these scans stitched together was used to help inform the processors of potential pitfalls during extrusion and dissection; and (2) the full resolution corrected data will serve as the permanent in situ record of the stratigraphy of the sample and will enable future researchers to perform a variety of analyses. So far, 92 of the 121 >4 mm particles separated during dissection pass 1 of sample 73001 have been individually scanned. These scans clearly show the lithology of each particle while keeping the particles in pristine condition. Because of the dust adhering to particle exteriors it would otherwise be impossible to determine lithologies in a non-contaminating way. Thus far the types of lithologies seen in sample 73001 (e.g., regolith breccias, impact-melt breccias, agglutinates, and basalts) are similar to those previously identified in sample 73002 [2]. By the time of the meeting, all particles from all 3 dissection passes will have been scanned and statistics on the different lithologies in 73001 compiled. References: [1] Shearer et al. (2020) 51st LPSC, abstract 1181. [2] Zeigler et al. (2020) 51st LPSC, abstract 3023. [3] Kent et al. (2022) This Volume. [4] McDonald et al. (2022) European Lunar Symposium. [5] Gross et al (2022) This volume.

Moon↗
DOE OSTI2023

Arabinogalactan Structures of Repetitive Serine-Hydroxyproline Glycomodule Expressed by Arabidopsis Cell Suspension Cultures

Arabinogalactan-proteins (AGPs) are members of the hydroxyproline-rich glycoprotein (HRGP) superfamily. They are heavily glycosylated with arabinogalactans, which are usually composed of a β-1,3-linked galactan backbone with 6-O-linked galactosyl, oligo-1,6-galactosyl, or 1,6-galactan side chains that are further decorated with arabinosyl, glucuronosyl, rhamnosyl, and/or fucosyl residues. Here, our work with Hyp-O-polysaccharides isolated from (Ser-Hyp)32-EGFP (enhanced green fluorescent protein) fusion glycoproteins overexpressed in transgenic Arabidopsis suspension culture is consistent with the common structural features of AGPs isolated from tobacco. In addition, this work confirms the presence of β-1,6-linkage on the galactan backbone identified previously in AGP fusion glycoproteins expressed in tobacco suspension culture. Furthermore, the AGPs expressed in Arabidopsis suspension culture lack terminal-rhamnosyl residues and have a much lower level of glucuronosylation compared with those expressed in tobacco suspension culture. These differences not only suggest the presence of distinct glycosyl transferases for AGP glycosylation in the two systems, but also indicate the existence of minimum AG structures for type II AG functional features.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2024

Technical note: Optimizing the in situ cosmogenic 36 Cl extraction and measurement workflow for geologic applications

Abstract. In situ cosmogenic 36Cl analysis by accelerator mass spectrometry (AMS) is routinely employed to date Quaternary surfaces and assess rates of landscape evolution. However, standard laboratory preparation procedures for 36Cl dating require the addition of large amounts of isotopically enriched chlorine spike solution; these solutions are expensive and increasingly difficult to acquire from commercial sources. In addition, the typical workflow for 36Cl dating involves measuring both 35Cl/37Cl and 36Cl/Cl concurrently on the high-energy (post-accelerator) end of the AMS system, but 35Cl/37Cl determinations using this technique can be complicated by isotope fractionation and system memory during measurement. The traditional workflow also does not provide 36Cl extraction laboratories with the data needed to calculate native Cl concentrations in advance of 36Cl/Cl measurements. In light of these concerns, we present an improved workflow for extracting and measuring chlorine in geologic materials. Our initial step is to characterize 35Cl/37Cl on sample aliquots of up to ∼1 g prepared in Ag(Cl, Br) matrices, which greatly reduces the amount of isotopically enriched spike solution required to measure native Cl content in each sample. To avoid potential issues with isotope fractionation through the accelerator, 35Cl/37Cl is measured on the low-energy, pre-accelerator end of the AMS line. Then, for 36Cl/Cl measurements, we extract Cl as AgCl or Ag(Cl, Br) in analytical batches with a consistent total Cl load across all samples; this step is intended to minimize source memory effects during 36Cl/Cl measurements and allows the preparation of AMS standards that are customized to match known Cl contents in the samples. To assess the efficacy of this extraction and measurement workflow, we compare chlorine isotope ratio measurements on seven geologic samples prepared using standard procedures and the updated workflow. Measurements of 35Cl/37Cl and 36Cl/Cl are consistent between the two workflows, and 35Cl/37Cl values measured using our methods have considerably higher precision than those measured following standard protocols. The chemical preparation and measurement workflow presented here (1) reduces the amount of isotopically enriched chlorine spike used per rock sample by up to 95 %; (2) identifies rocks with high native Cl concentrations, which may be lower priority for 36Cl surface exposure dating, at an early stage of analysis; and (3) allows laboratory users to maintain control over the total chlorine content within and across analytical batches. These methods can be incorporated into existing laboratory and AMS protocols for 36Cl analyses and will increase the accessibility of 36Cl dating for geologic applications.

58 GEOSCIENCES↗
DOE OSTI2020

Materials Data on Ag8Sb5As3S16 by Materials Project

Ag8Sb5As3S16 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Ag–S bond distances ranging from 2.62–3.47 Å. In the second Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to six S2- atoms. There are a spread of Ag–S bond distances ranging from 2.62–3.48 Å. In the third Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Ag–S bond distances ranging from 2.60–3.48 Å. In the fourth Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Ag–S bond distances ranging from 2.60–3.46 Å. In the fifth Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Ag–S bond distances ranging from 2.57–3.35 Å. In the sixth Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Ag–S bond distances ranging from 2.55–3.36 Å. In the seventh Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Ag–S bond distances ranging from 2.56–3.37 Å. In the eighth Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Ag–S bond distances ranging from 2.56–3.37 Å. There are five inequivalent Sb+3.40+ sites. In the first Sb+3.40+ site, Sb+3.40+ is bonded in a distorted square pyramidal geometry to five S2- atoms. There are a spread of Sb–S bond distances ranging from 2.50–3.06 Å. In the second Sb+3.40+ site, Sb+3.40+ is bonded in a 4-coordinate geometry to four S2- atoms. There are a spread of Sb–S bond distances ranging from 2.51–2.86 Å. In the third Sb+3.40+ site, Sb+3.40+ is bonded in a 4-coordinate geometry to four S2- atoms. There are a spread of Sb–S bond distances ranging from 2.51–2.83 Å. In the fourth Sb+3.40+ site, Sb+3.40+ is bonded in a 4-coordinate geometry to four S2- atoms. There are a spread of Sb–S bond distances ranging from 2.51–2.91 Å. In the fifth Sb+3.40+ site, Sb+3.40+ is bonded in a 4-coordinate geometry to four S2- atoms. There are a spread of Sb–S bond distances ranging from 2.48–3.16 Å. There are three inequivalent As+2.33+ sites. In the first As+2.33+ site, As+2.33+ is bonded in a 3-coordinate geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.27–2.34 Å. In the second As+2.33+ site, As+2.33+ is bonded in a distorted T-shaped geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.27–2.34 Å. In the third As+2.33+ site, As+2.33+ is bonded in a 3-coordinate geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.27–2.34 Å. There are sixteen inequivalent S2- sites. In the first S2- site, S2- is bonded to two Ag1+ and two Sb+3.40+ atoms to form distorted corner-sharing SAg2Sb2 tetrahedra. In the second S2- site, S2- is bonded in a 5-coordinate geometry to two Ag1+ and three Sb+3.40+ atoms. In the third S2- site, S2- is bonded to two Ag1+ and two Sb+3.40+ atoms to form distorted corner-sharing SAg2Sb2 tetrahedra. In the fourth S2- site, S2- is bonded to two Ag1+ and two Sb+3.40+ atoms to form distorted corner-sharing SAg2Sb2 tetrahedra. In the fifth S2- site, S2- is bonded to two Ag1+, one Sb+3.40+, and one As+2.33+ atom to form distorted corner-sharing SAg2SbAs tetrahedra. In the sixth S2- site, S2- is bonded to two Ag1+, one Sb+3.40+, and one As+2.33+ atom to form distorted corner-sharing SAg2SbAs tetrahedra. In the seventh S2- site, S2- is bonded to two Ag1+ and two Sb+3.40+ atoms to form distorted corner-sharing SAg2Sb2 tetrahedra. In the eighth S2- site, S2- is bonded to two Ag1+, one Sb+3.40+, and one As+2.33+ atom to form distorted corner-sharing SAg2SbAs tetrahedra. In the ninth S2- site, S2- is bonded in a 4-coordinate geometry to four Ag1+ and one As+2.33+ atom. In the tenth S2- site, S2- is bonded in a 4-coordinate geometry to four Ag1+ and one As+2.33+ atom. In the eleventh S2- site, S2- is bonded in a 4-coordinate geometry to four Ag1+ and one As+2.33+ atom. In the twelfth S2- site, S2- is bonded in a 6-coordinate geometry to four Ag1+ and two Sb+3.40+ atoms. In the thirteenth S2- site, S2- is bonded in a 6-coordinate geometry to four Ag1+ and two Sb+3.40+ atoms. In the fourteenth S2- site, S2- is bonded in a 6-coordinate geometry to four Ag1+, one Sb+3.40+, and one As+2.33+ atom. In the fifteenth S2- site, S2- is bonded in a 6-coordinate geometry to four Ag1+, one Sb+3.40+, and one As+2.33+ atom. In the sixteenth S2- site, S2- is bonded in a 6-coordinate geometry to four Ag1+, one Sb+3.40+, and one As+2.33+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cu2Ag5Se4NO15 by Materials Project

Ag5Cu2NSe4O15 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are five inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to six O2- atoms. There are a spread of Ag–O bond distances ranging from 2.33–2.99 Å. In the second Ag1+ site, Ag1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Ag–O bond distances ranging from 2.35–2.77 Å. In the third Ag1+ site, Ag1+ is bonded in a distorted linear geometry to two O2- atoms. Both Ag–O bond lengths are 2.41 Å. In the fourth Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Ag–O bond distances ranging from 2.22–2.76 Å. In the fifth Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Ag–O bond distances ranging from 2.21–2.77 Å. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded in a distorted square co-planar geometry to four O2- atoms. There is three shorter (1.98 Å) and one longer (1.99 Å) Cu–O bond length. In the second Cu2+ site, Cu2+ is bonded in an octahedral geometry to six O2- atoms. There are a spread of Cu–O bond distances ranging from 2.00–2.53 Å. N5+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.26–1.28 Å. There are four inequivalent Se4+ sites. In the first Se4+ site, Se4+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There is two shorter (1.74 Å) and one longer (1.75 Å) Se–O bond length. In the second Se4+ site, Se4+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There is one shorter (1.74 Å) and two longer (1.75 Å) Se–O bond length. In the third Se4+ site, Se4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There is two shorter (1.73 Å) and one longer (1.76 Å) Se–O bond length. In the fourth Se4+ site, Se4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.72–1.76 Å. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Ag1+, one Cu2+, and one Se4+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ag1+, one Cu2+, and one Se4+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two Ag1+, one Cu2+, and one Se4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two Ag1+, one Cu2+, and one Se4+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Ag1+, one Cu2+, and one Se4+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to two Ag1+, one Cu2+, and one Se4+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ag1+ and one Se4+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ag1+ and one Se4+ atom. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ag1+, one Cu2+, and one Se4+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ag1+, one Cu2+, and one Se4+ atom. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to one Ag1+, one Cu2+, and one Se4+ atom. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to one Ag1+, one Cu2+, and one Se4+ atom. In the thirteenth O2- site, O2- is bonded in a distorted single-bond geometry to one N5+ atom. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to two Ag1+ and one N5+ atom. In the fifteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Ag1+ and one N5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AgAsO3 by Materials Project

AgAsO3 crystallizes in the orthorhombic Pca2_1 space group. The structure is three-dimensional. there are six inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 2-coordinate geometry to four O2- atoms. There are a spread of Ag–O bond distances ranging from 2.26–2.64 Å. In the second Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Ag–O bond distances ranging from 2.27–2.72 Å. In the third Ag1+ site, Ag1+ is bonded in a 2-coordinate geometry to seven O2- atoms. There are a spread of Ag–O bond distances ranging from 2.27–2.97 Å. In the fourth Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to seven O2- atoms. There are a spread of Ag–O bond distances ranging from 2.39–3.15 Å. In the fifth Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Ag–O bond distances ranging from 2.31–2.63 Å. In the sixth Ag1+ site, Ag1+ is bonded to five O2- atoms to form distorted AgO5 trigonal bipyramids that share a cornercorner with one AsO6 octahedra and corners with five AsO4 tetrahedra. The corner-sharing octahedral tilt angles are 58°. There are a spread of Ag–O bond distances ranging from 2.33–2.81 Å. There are six inequivalent As5+ sites. In the first As5+ site, As5+ is bonded to six O2- atoms to form AsO6 octahedra that share corners with two equivalent AsO6 octahedra, corners with four AsO4 tetrahedra, and a cornercorner with one AgO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 47°. There are a spread of As–O bond distances ranging from 1.83–1.90 Å. In the second As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two AsO6 octahedra and corners with two equivalent AgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of As–O bond distances ranging from 1.70–1.77 Å. In the third As5+ site, As5+ is bonded to six O2- atoms to form AsO6 octahedra that share corners with two equivalent AsO6 octahedra and corners with four AsO4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. There are a spread of As–O bond distances ranging from 1.85–1.89 Å. In the fourth As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two AsO6 octahedra and a cornercorner with one AgO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of As–O bond distances ranging from 1.69–1.77 Å. In the fifth As5+ site, As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with two AsO6 octahedra and corners with two equivalent AgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 53–55°. There are a spread of As–O bond distances ranging from 1.69–1.78 Å. In the sixth As5+ site, As5+ is bonded to four O2- atoms to form corner-sharing AsO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–55°. There are a spread of As–O bond distances ranging from 1.69–1.78 Å. There are eighteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ag1+ and two As5+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Ag1+ and two As5+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Ag1+ and one As5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ag1+ and two As5+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Ag1+ and two As5+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ag1+ and two As5+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to three Ag1+ and one As5+ atom. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to three Ag1+ and one As5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ag1+ and two As5+ atoms. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to two Ag1+ and one As5+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ag1+ and two As5+ atoms. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ag1+ and two As5+ atoms. In the thirteenth O2- site, O2- is bonded in a 1-coordinate geometry to three Ag1+ and one As5+ atom. In the fourteenth O2- site, O2- is bonded in a trigonal planar geometry to two Ag1+ and one As5+ atom. In the fifteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Ag1+ and two As5+ atoms. In the sixteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ag1+ and one As5+ atom. In the seventeenth O2- site, O2- is bonded in a bent 120 degrees geometry to two As5+ atoms. In the eighteenth O2- site, O2- is bonded in a 4-coordinate geometry to three Ag1+ and one As5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on V12Ag5O32 by Materials Project

V12Ag5O32 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are nine inequivalent V+4.92+ sites. In the first V+4.92+ site, V+4.92+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of V–O bond distances ranging from 1.66–2.02 Å. In the second V+4.92+ site, V+4.92+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of V–O bond distances ranging from 1.66–2.01 Å. In the third V+4.92+ site, V+4.92+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of V–O bond distances ranging from 1.66–2.02 Å. In the fourth V+4.92+ site, V+4.92+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.63–2.28 Å. In the fifth V+4.92+ site, V+4.92+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.63–2.28 Å. In the sixth V+4.92+ site, V+4.92+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.65–2.31 Å. In the seventh V+4.92+ site, V+4.92+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.66–2.40 Å. In the eighth V+4.92+ site, V+4.92+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.67–2.37 Å. In the ninth V+4.92+ site, V+4.92+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 1.66–2.41 Å. There are four inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded to six O2- atoms to form edge-sharing AgO6 octahedra. There are a spread of Ag–O bond distances ranging from 2.46–2.54 Å. In the second Ag1+ site, Ag1+ is bonded to six O2- atoms to form edge-sharing AgO6 octahedra. There are a spread of Ag–O bond distances ranging from 2.45–2.55 Å. In the third Ag1+ site, Ag1+ is bonded to six O2- atoms to form edge-sharing AgO6 octahedra. There are a spread of Ag–O bond distances ranging from 2.46–2.53 Å. In the fourth Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Ag–O bond distances ranging from 2.23–2.77 Å. There are twenty-four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one V+4.92+ and one Ag1+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one V+4.92+ and one Ag1+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one V+4.92+ and one Ag1+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two V+4.92+ and one Ag1+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two V+4.92+ and one Ag1+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two V+4.92+ and one Ag1+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two V+4.92+ and one Ag1+ atom. In the eighth O2- site, O2- is bonded in a bent 120 degrees geometry to two V+4.92+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to two V+4.92+ and one Ag1+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three V+4.92+ atoms. In the eleventh O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three V+4.92+ atoms. In the twelfth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three V+4.92+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to three V+4.92+ atoms. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to three V+4.92+ atoms. In the fifteenth O2- site, O2- is bonded in a 3-coordinate geometry to three V+4.92+ atoms. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to four V+4.92+ atoms. In the seventeenth O2- site, O2- is bonded in a 2-coordinate geometry to four V+4.92+ atoms. In the eighteenth O2- site, O2- is bonded in a 2-coordinate geometry to four V+4.92+ atoms. In the nineteenth O2- site, O2- is bonded in a distorted single-bond geometry to one V+4.92+ and two equivalent Ag1+ atoms. In the twentieth O2- site, O2- is bonded in a distorted single-bond geometry to one V+4.92+ and two equivalent Ag1+ atoms. In the twenty-first O2- site, O2- is bonded in a distorted single-bond geometry to one V+4.92+ and two Ag1+ atoms. In the twenty-second O2- site, O2- is bonded in a distorted single-bond geometry to one V+4.92+ and two equivalent Ag1+ atoms. In the twenty-third O2- site, O2- is bonded in a distorted single-bond geometry to one V+4.92+ and three Ag1+ atoms. In the twenty-fourth O2- site, O2- is bonded in a distorted single-bond geometry to one V+4.92+ and two Ag1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Benzenesulfonamide Derivatives as Complexants and Extractants for Addressing the Mercury Problem at the Savannah River Site

Mercury (Hg) is a major global pollutant arising from both natural and anthropogenic sources. Its widespread use in medicinal and industrial applications makes it a common chemical exposure and environmental pollutant. It can exist in several forms which include: Metallic mercury (Hg{sup 0}), mercurous (Hg{sub 2}{sup 2+}), mercuric salts (Hg{sup 2+}), and organic mercury (e.g. CH{sub 3}Hg{sup +}), with the latter being the most toxic of all the species. Due to mercury's high toxicity, new approaches towards its detection has received significant attention in the scientific community. Mercury exposure at the Savannah River Site (SRS) has been a recent concern especially with increasing amounts of organic mercury in the saltstone. It originates mainly from its use as an acidic dissolution catalyst of aluminum cladding from target fuels within the uranium and plutonium processing operations [1]. It is present to an amount of about 60 metric tons in the high-level waste (HLW) tanks. Organic Mercury species have been found in low activity waste (LAW) at the site that eventually ends up in the saltstone. Therefore, there is a need for: i) Converting organic mercury to other less toxic forms and ii) Complexation and removal of Hg prior of disposal of LAW in saltstone. Various methods have been developed for selective sensing of mercury in the presence of other toxic metals. These methods include using ligands that can form organo-soluble metal complexes with different optical and spectroscopic properties that can be used for toxic metal sensing. In 2005, our group pioneered an ion-exchange extraction method, in which o-phenylenediamine-derived disulfonamides were used to complex and selectively extract and sense Pb{sup 2+} from aqueous solutions into an organic phase [2,3]. Herein, a disulfonamide and a bis-dansylamide have been shown to extract, complex and sense Hg(II). Ligand 1: The crystal structure of the disulfonamide-Hg complex confirms the complexation of Hg(II) with the ligand. Complexation was corroborated by the {sup 1}H-NMR spectra obtained after contacting solutions of various concentrations of Hg{sup 2+} with 2 mM ligand in chloroform. Distinct resonances are observed at Hg/L ratio of 0.5 that are also observed for the isolated 1:2 complex. In the presence of excess mercury, new resonances, as well as the movement of Et{sub 3}N resonances indicate the formation of a different Hg-sulfonamide-triethylamine complex, presumably having 1:1 Hg:L stoichiometry. The electronic spectra of aqueous phases after extraction show that there was no free ligand absorption at 0.5 eq of Hg, indicating a complete complexation. Complexation was also confirmed by the UV-visible titrations with Hg{sup 2+} at constant ligand concentration. pH-dependent extraction carried out shows that extraction of Hg(II) by ligand 1 was over 90% for most alkaline pHs. Ligand 2: The crystal structure of the Ligand 2 complex formed with Hg(OAc){sub 2} shows a remarkable coordination pattern with 4:2 metal:ligand stoichiometry. The fluorescent bis-dansyl disulfonamide derivative was found to complex and sense HgCl{sub 2} and Hg(OAc){sub 2} by demonstrating fluorescence quenching upon Hg(II) addition in comparison with other metals (Zn(II), Cd(II), Pb(II)). No were observed for Cu(II), Ag(I) and Co(II). We have shown the complexation of Hg(II) by a disulfonamide and a bis-dansyl disulfonamide ligand using several spectroscopic methods. Ligand 1 was able to extract mercury into chloroform and form a complex in the presence of excess mercury by synergistic complexation with triethylamine acting as a co-ligand. X-ray and NMR both confirm a 1:2 HgL{sub 2} stoichiometry. Ligand 2 can be used for sensing of Hg(II) as fluorescence quenching was observed after addition of Hg(II)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Materials Data on Ag3Bi7S12 by Materials Project

Ag3Bi7S12 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded to six S2- atoms to form AgS6 octahedra that share corners with two equivalent BiS6 octahedra, corners with four equivalent BiS5 square pyramids, edges with two equivalent AgS6 octahedra, and edges with six equivalent BiS5 square pyramids. The corner-sharing octahedral tilt angles are 54°. There are two shorter (2.54 Å) and four longer (2.90 Å) Ag–S bond lengths. In the second Ag1+ site, Ag1+ is bonded to six S2- atoms to form AgS6 octahedra that share corners with five BiS6 octahedra, edges with four equivalent AgS6 octahedra, and edges with eight BiS6 octahedra. The corner-sharing octahedra tilt angles range from 4–8°. There are a spread of Ag–S bond distances ranging from 2.63–3.05 Å. There are four inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with two equivalent BiS6 octahedra, corners with three equivalent AgS6 octahedra, edges with three equivalent AgS6 octahedra, and edges with seven BiS6 octahedra. The corner-sharing octahedra tilt angles range from 4–8°. There are a spread of Bi–S bond distances ranging from 2.77–2.98 Å. In the second Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with two equivalent BiS6 octahedra, corners with four equivalent AgS6 octahedra, edges with six equivalent AgS6 octahedra, and edges with six BiS6 octahedra. The corner-sharing octahedra tilt angles range from 4–8°. There are two shorter (2.81 Å) and four longer (2.87 Å) Bi–S bond lengths. In the third Bi3+ site, Bi3+ is bonded to five S2- atoms to form distorted BiS5 square pyramids that share corners with two equivalent AgS6 octahedra, corners with two equivalent BiS6 octahedra, edges with three equivalent AgS6 octahedra, and edges with four equivalent BiS5 square pyramids. The corner-sharing octahedra tilt angles range from 14–65°. There are a spread of Bi–S bond distances ranging from 2.63–2.85 Å. In the fourth Bi3+ site, Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share a cornercorner with one AgS6 octahedra, corners with three BiS6 octahedra, corners with two equivalent BiS5 square pyramids, edges with two equivalent AgS6 octahedra, and edges with five BiS6 octahedra. The corner-sharing octahedra tilt angles range from 4–54°. There are a spread of Bi–S bond distances ranging from 2.66–3.00 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to three Bi3+ atoms. In the second S2- site, S2- is bonded to one Ag1+ and four Bi3+ atoms to form SAgBi4 square pyramids that share corners with three SAg3Bi3 octahedra, corners with two equivalent SAgBi3 tetrahedra, edges with five SAg3Bi3 octahedra, and edges with two equivalent SAgBi4 square pyramids. The corner-sharing octahedra tilt angles range from 3–5°. In the third S2- site, S2- is bonded to one Ag1+ and three Bi3+ atoms to form distorted SAgBi3 tetrahedra that share a cornercorner with one SAg2Bi4 octahedra, corners with six SAgBi4 square pyramids, corners with three equivalent SAgBi3 tetrahedra, and edges with three equivalent SAg2Bi3 square pyramids. The corner-sharing octahedral tilt angles are 0°. In the fourth S2- site, S2- is bonded to three equivalent Ag1+ and three Bi3+ atoms to form SAg3Bi3 octahedra that share corners with four SAg3Bi3 octahedra, a cornercorner with one SAgBi4 square pyramid, edges with ten SAg3Bi3 octahedra, and edges with two equivalent SAgBi4 square pyramids. The corner-sharing octahedra tilt angles range from 0–7°. In the fifth S2- site, S2- is bonded to two equivalent Ag1+ and four Bi3+ atoms to form SAg2Bi4 octahedra that share corners with three SAg3Bi3 octahedra, corners with two equivalent SAgBi4 square pyramids, a cornercorner with one SAgBi3 tetrahedra, edges with seven SAg3Bi3 octahedra, and edges with three equivalent SAgBi4 square pyramids. The corner-sharing octahedra tilt angles range from 0–7°. In the sixth S2- site, S2- is bonded to two equivalent Ag1+ and three equivalent Bi3+ atoms to form distorted SAg2Bi3 square pyramids that share corners with two equivalent SAg2Bi3 square pyramids, corners with four equivalent SAgBi3 tetrahedra, edges with five equivalent SAg2Bi3 square pyramids, and edges with three equivalent SAgBi3 tetrahedra.

36 MATERIALS SCIENCE↗
NASA NTRSDate not supplied

X-Ray Computed Tomography of Apollo Drive Tube 73001 as Part of the Apollo Next Generation Sample Analysis Program

Introduction: Starting in 2019, the Apollo Next Generation Sample Analysis (ANGSA) Program has enabled consortium studies of specially curated Apollo samples that were previously unstudied (or under studied). This program was intended as a participating scientist program for these Apollo samples, as well as a preparation for upcoming lunar sample return missions (e.g., Artemis). The work began with studies of unsealed core tube 73002 [1,2] that is the upper ~35 cm of an Apollo 17 double drive tube (~70 cm total depth) collected on the landslide deposit near Lara Crater at Station 3 in the Taurus Littrow Valley. More recently the program extended to the study of a variety of frozen Apollo 17 samples [3], as well as the gas extraction [4] and dissection [5] of 73001, the lower half of the station 3 double drive tube. Sample 73001 was sealed under vacuum on the Moon in a Core Sample Vacuum Container (CSVC). In this abstract we will examine the role of X-ray Computed Tomography (XCT) during the preliminary examination process for sealed core 73001, including: (1) engineering scans to aid in understanding the gas extraction process, (2) whole-core scanning prior to opening to inform extrusion and dissection work, and (3) individual particle scanning to characterize rock fragment lithologies for follow on studies. Methodology: Sample 73001 is a 33 cm long, 4 cm diameter regolith sample collected inside a lunar drive tube (~1 mm aluminum walls). That drive tube was sealed inside a 0.5 mm thick stainless steel (SS) CSVC. XCT scans for engineering purposes were done on the Nikon XTH 320 system at Johnson Space Center using the 225 kV multi-metal reflection source at 215 kV, 179 A, and a 38.49 m voxel size. Individual >4 mm particles separated from the core during processing (then triply sealed in Teflon bags) were also scanned at JSC using the 180 kV source at 90 kV, 33 A, and a 2.98 – 10.65 m voxel size. Whole-core scans were done at the University of Texas High-Resolution X-ray Computed Tomography Facility (UTCT) on the 225 kV reflection source on the North Star Imaging cabinet XCT system. These scans included: (1) a series of 9 overlapping super-resolution scans each covering a ~4 cm length of the tube at 190 kV, 180 µA, and a 12.9 µm voxel size and (2) a lower resolution continuous helical scan of the entire core at 190 kV, 180 µA, and a 51.8 µm voxel size. Progress and Results: Before piercing and extracting the gas from sample 73001, an XCT scan of the bottom portion of the CSVC was used to confirm the location of the Teflon cap on the inner drive tube and whether there was an “air” gap between the Teflon cap and the CSVC. This was to ensure the Teflon cap (which immobilized the soil inside the drive tube) was not accidentally pierced during gas extraction. Similarly, after piercing, the bottom and top portions of the CSVC were scanned in order to capture engineering knowledge about the results of the piercing process, as well as the metal knife edge vacuum seal (SS into an In-Ag alloy). Both scans will provide constraints on future work of this type, both for the design of tools used on the lunar surface during Artemis, as well as how we open future samples of this type. An unexpected finding from these engineering scans was that the device in the drive tube that immobilizes the regolith (the keeper) was not seated in the tube properly. This meant that (1) the drive tube could not be removed from the CSVC for the trip to UTCT, and (2) the procedure for opening and extruding the drive tube had to be modified. Had either of these things not been known prior to opening the CSVC, it could have led to an inability to XCT scan the whole core at high resolution and/or potential disruption of the core stratigraphy during extrusion. At UTCT, the entire length of the core was scanned at high resolution (12.9 microns per voxel). This scan serves multiple purposes: (1) A lower resolution (and uncorrected) version of these scans stitched together was used to help inform the processors of potential pitfalls during extrusion and dissection (voids, angular fragments at the edges of the sample, etc.); and (2) the full resolution corrected data will serve as the permanent in situ record of the stratigraphy of the sample and will enable future researchers to perform a variety of analyses. All 121 >4 mm particles separated during dissection pass 1 of sample 73001 have been individually scanned. These scans clearly show the lithology of each particle while keeping the particles in pristine condition (they are individually triply bagged in Teflon within our N2 purged processing cabinets). Because of the dust adhering to particle exteriors, it would otherwise be impossible to determine lithologies in a non-contaminating way. Thus far the types of lithologies seen in sample 73001 (e.g., regolith breccias, impact-melt breccias, agglutinates, and bas-alts) are similar to those previously identified in sample 73002 [2]. By the time of the meeting, all particles from all 3 dissection passes will have been scanned and statistics on the different lithologies in 73001 compiled. References: [1] Shearer et al. (2020) 51st LPSC, abstract 1181. [2] Zeigler et al. (2020) 51st LPSC, abstract 3023. [3] Kent et al. (2022) This Volume. [4] McDonald et al. (2022) European Lunar Symposium. [5] Gross et al (2022) This volume.

Moon↗
NASA NTRS2003

Truly Incomplete and Complex Chromosomal Exchanges in Human Fibroblast Cells Exposed In Situ to Energetic Heavy Ions

Confluent human fibroblast cells (AG 1522) were irradiated with gamma rays, 490 MeV/nucleon Si, or with Fe ions at either 200 or 500 MeV/nucleon. The cells were allowed to repair at 37 C for 24 hours after exposure, and a chemically induced premature chromosome condensation (PCC) technique was used to condense chromosomes in the G2 phase of the cell cycle. Incomplete and complex exchanges were analyzed in the irradiated samples. In order to verify that chromosomal breaks were truly unrejoined, chromosome aberrations were analyzed using a combination of whole chromosome specific probes and probes specific for the telomere region of the chromosome. Results showed that the frequency of unrejoined chromosome breaks was higher after high-LET radiation, and consequently, the ratio of incomplete to complete exchanges increased steadily with LET up to 440 keV/micron, the highest LET value in the present study. For samples exposed to 200 MeV/nucleon Fe ions, chromosome aberrations were analyzed using the multicolor FISH (mFISH) technique that allow identification of both complex and truly incomplete exchanges. Results of the mFISH study showed that 0.7 and 3 Gy dose of the Fe ions produced similar ratios of complex to simple exchanges and incomplete to complete exchanges, values for which were higher than those obtained after a 6 Gy gamma exposure. After 0.7 Gy of Fe ions, most complex aberrations were found to involve three or four chromosomes, which is a likely indication of the maximum number of chromosome domains traversed by a single Fe ion track.

Wu, Honglu↗