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At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on CeMg(N3O13)2 by Materials Project

MgO8Ce(NO3)6 is alpha Niobium phosphide-like structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of two Ce(NO3)6 clusters and two MgO8 clusters. In each Ce(NO3)6 cluster, Ce is bonded in a cuboctahedral geometry to twelve O atoms. There are a spread of Ce–O bond distances ranging from 2.53–2.62 Å. There are three inequivalent N sites. In the first N site, N is bonded in a trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.23–1.29 Å. In the second N site, N is bonded in a trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.24–1.28 Å. In the third N site, N is bonded in a trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.24–1.29 Å. There are nine inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to one Ce and one N atom. In the second O site, O is bonded in a single-bond geometry to one N atom. In the third O site, O is bonded in a distorted single-bond geometry to one Ce and one N atom. In the fourth O site, O is bonded in a distorted single-bond geometry to one Ce and one N atom. In the fifth O site, O is bonded in a distorted single-bond geometry to one Ce and one N atom. In the sixth O site, O is bonded in a single-bond geometry to one N atom. In the seventh O site, O is bonded in a distorted water-like geometry to one Ce and one N atom. In the eighth O site, O is bonded in a single-bond geometry to one N atom. In the ninth O site, O is bonded in a distorted single-bond geometry to one Ce and one N atom. In each MgO8 cluster, Mg is bonded in an octahedral geometry to six O atoms. There are a spread of Mg–O bond distances ranging from 2.08–2.22 Å. There are four inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one O atom. The O–O bond length is 1.24 Å. In the second O site, O is bonded in a 2-coordinate geometry to one Mg and one O atom. The O–O bond length is 1.30 Å. In the third O site, O is bonded in a 2-coordinate geometry to one Mg and one O atom. In the fourth O site, O is bonded in a distorted bent 120 degrees geometry to one Mg and one O atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ThZn(N3O13)2 by Materials Project

Th(NO3)6ZnO6O2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four water molecules, two Th(NO3)6 clusters, and two zinc;hexahydrate molecules. In each Th(NO3)6 cluster, Th is bonded in a cuboctahedral geometry to twelve O atoms. There are a spread of Th–O bond distances ranging from 2.54–2.64 Å. There are three inequivalent N sites. In the first N site, N is bonded in a trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.25–1.28 Å. In the second N site, N is bonded in a trigonal planar geometry to three O atoms. There is one shorter (1.22 Å) and two longer (1.29 Å) N–O bond length. In the third N site, N is bonded in a trigonal planar geometry to three O atoms. There is one shorter (1.25 Å) and two longer (1.27 Å) N–O bond length. There are nine inequivalent O sites. In the first O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the second O site, O is bonded in a single-bond geometry to one N atom. In the third O site, O is bonded in a single-bond geometry to one N atom. In the fourth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the fifth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the sixth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom. In the seventh O site, O is bonded in a single-bond geometry to one N atom. In the eighth O site, O is bonded in a distorted water-like geometry to one Th and one N atom. In the ninth O site, O is bonded in a distorted single-bond geometry to one Th and one N atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ErN7O15 by Materials Project

Er(NO3)5N2 crystallizes in the trigonal P3_1 space group. The structure is zero-dimensional and consists of six ammonia molecules and three Er(NO3)5 clusters. In each Er(NO3)5 cluster, Er3+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Er–O bond distances ranging from 2.40–2.53 Å. There are five inequivalent N+3.86+ sites. In the first N+3.86+ site, N+3.86+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.23 Å) and two longer (1.28 Å) N–O bond length. In the second N+3.86+ site, N+3.86+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.23 Å) and two longer (1.28 Å) N–O bond length. In the third N+3.86+ site, N+3.86+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.23 Å) and two longer (1.28 Å) N–O bond length. In the fourth N+3.86+ site, N+3.86+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.23–1.28 Å. In the fifth N+3.86+ site, N+3.86+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.23 Å) and two longer (1.28 Å) N–O bond length. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Er3+ and one N+3.86+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one N+3.86+ atom. In the third O2- site, O2- is bonded in a distorted water-like geometry to one Er3+ and one N+3.86+ atom. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one Er3+ and one N+3.86+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Er3+ and one N+3.86+ atom. In the sixth O2- site, O2- is bonded in a distorted L-shaped geometry to one Er3+ and one N+3.86+ atom. In the seventh O2- site, O2- is bonded in a single-bond geometry to one N+3.86+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to one Er3+ and one N+3.86+ atom. In the ninth O2- site, O2- is bonded in a single-bond geometry to one N+3.86+ atom. In the tenth O2- site, O2- is bonded in a distorted water-like geometry to one Er3+ and one N+3.86+ atom. In the eleventh O2- site, O2- is bonded in a single-bond geometry to one N+3.86+ atom. In the twelfth O2- site, O2- is bonded in a distorted water-like geometry to one Er3+ and one N+3.86+ atom. In the thirteenth O2- site, O2- is bonded in a single-bond geometry to one N+3.86+ atom. In the fourteenth O2- site, O2- is bonded in a distorted L-shaped geometry to one Er3+ and one N+3.86+ atom. In the fifteenth O2- site, O2- is bonded in a distorted single-bond geometry to one Er3+ and one N+3.86+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ag(NO2)3 by Materials Project

(Ag(NO3)2)2N2 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of four ammonia molecules and two Ag(NO3)2 sheets oriented in the (0, 0, 1) direction. In each Ag(NO3)2 sheet, Ag1+ is bonded in a 4-coordinate geometry to six O2- atoms. There are a spread of Ag–O bond distances ranging from 2.19–2.91 Å. There are two inequivalent N+3.67+ sites. In the first N+3.67+ site, N+3.67+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.22 Å) and two longer (1.29 Å) N–O bond length. In the second N+3.67+ site, N+3.67+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.23–1.29 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Ag1+ and one N+3.67+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Ag1+ and one N+3.67+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Ag1+ and one N+3.67+ atom. In the fourth O2- site, O2- is bonded in a distorted L-shaped geometry to one Ag1+ and one N+3.67+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one N+3.67+ atom. In the sixth O2- site, O2- is bonded in a bent 120 degrees geometry to one Ag1+ and one N+3.67+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CrP2H16N3O10 by Materials Project

CrP2H14(NO3)3H2O crystallizes in the monoclinic P2_1/c space group. The structure is one-dimensional and consists of four water molecules and two CrP2H14(NO3)3 ribbons oriented in the (0, 1, 0) direction. In each CrP2H14(NO3)3 ribbon, Cr3+ is bonded to three N3- and three O2- atoms to form CrN3O3 octahedra that share corners with two PO4 tetrahedra. There are one shorter (2.11 Å) and two longer (2.12 Å) Cr–N bond lengths. There are one shorter (2.00 Å) and two longer (2.01 Å) Cr–O bond lengths. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one CrN3O3 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. There are a spread of P–O bond distances ranging from 1.51–1.65 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one CrN3O3 octahedra and a cornercorner with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. There are a spread of P–O bond distances ranging from 1.51–1.62 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted trigonal non-coplanar geometry to one Cr3+ and three H1+ atoms. All N–H bond lengths are 1.03 Å. In the second N3- site, N3- is bonded in a distorted trigonal non-coplanar geometry to one Cr3+ and three H1+ atoms. All N–H bond lengths are 1.03 Å. In the third N3- site, N3- is bonded in a distorted trigonal non-coplanar geometry to one Cr3+ and three H1+ atoms. All N–H bond lengths are 1.03 Å. There are fourteen inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.06 Å) and one longer (1.44 Å) H–O bond length. 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 (1.53 Å) H–O bond length. In the third H1+ site, H1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.62 Å) H–O bond length. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the eleventh H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the twelfth H1+ site, H1+ is bonded in a single-bond geometry to one N3- atom. In the thirteenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fourteenth 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 nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr3+ and one P5+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one P5+ and one H1+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one P5+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Cr3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a single-bond geometry to one P5+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to one P5+ and one H1+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cr3+ and two H1+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pu(N4O9)2 by Materials Project

Pu(NO3)6N2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four ammonia molecules and two Pu(NO3)6 clusters. In each Pu(NO3)6 cluster, Pu4+ is bonded in a cuboctahedral geometry to twelve O2- atoms. There are a spread of Pu–O bond distances ranging from 2.44–2.48 Å. There are three inequivalent N4+ sites. In the first N4+ site, N4+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.22 Å) and two longer (1.29 Å) N–O bond length. In the second N4+ site, N4+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.22–1.29 Å. In the third N4+ site, N4+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.21–1.30 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Pu4+ and one N4+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Pu4+ and one N4+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one Pu4+ and one N4+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one N4+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Pu4+ and one N4+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one Pu4+ and one N4+ atom. In the seventh O2- site, O2- is bonded in a single-bond geometry to one N4+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to one Pu4+ and one N4+ atom. In the ninth O2- site, O2- is bonded in a single-bond geometry to one N4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(NO5)2 by Materials Project

Sr(NO3)2(O2)2 crystallizes in the monoclinic C2/c space group. The structure is one-dimensional and consists of eight hydrogen peroxide molecules and two Sr(NO3)2 ribbons oriented in the (1, 0, 1) direction. In each Sr(NO3)2 ribbon, Sr is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Sr–O bond distances ranging from 2.57–2.73 Å. N is bonded in a trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.23–1.32 Å. There are three inequivalent O sites. In the first O site, O is bonded in a distorted water-like geometry to one Sr and one N atom. In the second O site, O is bonded in a 1-coordinate geometry to two equivalent Sr and one N atom. In the third O site, O is bonded in a single-bond geometry to one N atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cd(NO4)2 by Materials Project

Cd(NO3)2O2 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of four hydrogen peroxide molecules and two Cd(NO3)2 sheets oriented in the (0, 0, 1) direction. In each Cd(NO3)2 sheet, Cd is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Cd–O bond distances ranging from 2.25–2.51 Å. There are two inequivalent N sites. In the first N site, N is bonded in a trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.23–1.31 Å. In the second N site, N is bonded in a trigonal planar geometry to three O atoms. There are a spread of N–O bond distances ranging from 1.26–1.28 Å. There are six inequivalent O sites. In the first O site, O is bonded in a water-like geometry to one Cd and one N atom. In the second O site, O is bonded in a bent 120 degrees geometry to one Cd and one N atom. In the third O site, O is bonded in a single-bond geometry to one N atom. In the fourth O site, O is bonded in a water-like geometry to one Cd and one N atom. In the fifth O site, O is bonded in a bent 120 degrees geometry to one Cd and one N atom. In the sixth O site, O is bonded in a distorted L-shaped geometry to one Cd and one N atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LuN7O15 by Materials Project

Lu(NO3)5N2 crystallizes in the trigonal P3_1 space group. The structure is zero-dimensional and consists of six ammonia molecules and three Lu(NO3)5 clusters. In each Lu(NO3)5 cluster, Lu3+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Lu–O bond distances ranging from 2.36–2.51 Å. There are five inequivalent N+3.86+ sites. In the first N+3.86+ site, N+3.86+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.23 Å) and two longer (1.28 Å) N–O bond length. In the second N+3.86+ site, N+3.86+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.23 Å) and two longer (1.28 Å) N–O bond length. In the third N+3.86+ site, N+3.86+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.23–1.29 Å. In the fourth N+3.86+ site, N+3.86+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.23–1.28 Å. In the fifth N+3.86+ site, N+3.86+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.22 Å) and two longer (1.28 Å) N–O bond length. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Lu3+ and one N+3.86+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one N+3.86+ atom. In the third O2- site, O2- is bonded in a distorted water-like geometry to one Lu3+ and one N+3.86+ atom. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one Lu3+ and one N+3.86+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Lu3+ and one N+3.86+ atom. In the sixth O2- site, O2- is bonded in a distorted L-shaped geometry to one Lu3+ and one N+3.86+ atom. In the seventh O2- site, O2- is bonded in a single-bond geometry to one N+3.86+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to one Lu3+ and one N+3.86+ atom. In the ninth O2- site, O2- is bonded in a single-bond geometry to one N+3.86+ atom. In the tenth O2- site, O2- is bonded in a distorted water-like geometry to one Lu3+ and one N+3.86+ atom. In the eleventh O2- site, O2- is bonded in a single-bond geometry to one N+3.86+ atom. In the twelfth O2- site, O2- is bonded in a distorted water-like geometry to one Lu3+ and one N+3.86+ atom. In the thirteenth O2- site, O2- is bonded in a single-bond geometry to one N+3.86+ atom. In the fourteenth O2- site, O2- is bonded in a distorted L-shaped geometry to one Lu3+ and one N+3.86+ atom. In the fifteenth O2- site, O2- is bonded in a distorted single-bond geometry to one Lu3+ and one N+3.86+ atom.

36 MATERIALS SCIENCE↗
NASA NTRS1986

N2O5 photolysis products investigated by fluorescence and optoacoustic techniques

Pulsed laser photolysis of N2O5 near 290 nm, coupled with fluorescence detection (calibrated by NO2 photoloysis), showed that the O(P-3) quantum yield is not more than 0.1. A pulsed laser optoacoustic technique in a flow tube was tested by photolysis of NO2 and then applied to N2O5. Nitric oxide was added to react with NO3 free radicals; the resulting increase in the optoacoustic signal confirmed the presence of NO3 free radicals. Based on the relative optoacoustic signals observed for NO2 and N2O5, the quantum yield for NO3 production is 0.8 + or - 0.2.

Barker, J. R.↗
NASA NTRS1989

Regulation of nitrogen uptake and assimilation: Effects of nitrogen source, root-zone pH, and aerial CO2 concentration on growth and productivity of soybeans

An important feature of controlled-environment crop production systems such as those to be used for life support of crews during space exploration is the efficient utilization of nitrogen supplies. Making decisions about the best sources of these supplies requires research into the relationship between nitrogen source and the physiological processes which regulate vegetative and reproductive plant growth. Work done in four areas within this research objective is reported: (1) experiments on the effects of root-zone pH on preferential utilization of NO3(-) versus NH4(+) nitrogen; (2) investigation of processes at the whole-plant level that regulate nitrogen uptake; (3) studies of the effects of atmospheric CO2 and NO3(-) supply on the growth of soybeans; and (4) examination of the role of NO3(-) uptake in enhancement of root respiration.

Raper, C. D.↗
NASA NTRS1997

Environmental modification of yield and nutrient composition of 'Waldmann's Green' leaf lettuce

Leaf number, dry weight, and nutrient composition of Lactuca sativa L. cv. Waldmann's Green leaves were compared following 9 days of treatment in a controlled environment room under various combinations of photosynthetic photon flux (PPF:350 vs 800 micromoles m-2 s-1), atmospheric CO2 level (ambient vs 1500 micromoles mol-1), and single-strength (1X:15 mM) vs double-strength (2X:30 mM) nitrogen (N) as NO3- alone or as NH4(+) + NO3- (1:5 molar ratio). CO2 enrichment greatly enhanced leaf number under all PPF and N conditions, but increased leaf dry weight only at high PPF. Conditions favoring high photosynthesis enhanced leaf starch content 3-fold, and protein content increased as much as 64% with 2X NH4(+)+NO3-. Free sugar content was 6 to 9% of leaf dry weight for all treatment combinations, while fat was 1.5 to 3.5%. Ash content varied from 15 to 20% of leaf dry weight. Modified controlled environments can be used to enhance the nutritional content as well as the yield of crops to be used for life support in space-deployed, self-sustaining human habitats. Leaf lettuce is a useful model crop for demonstrating the potential of nutritional value added by environmental manipulation.

Non-NASA Center↗
NASA NTRS1991

Increase in nitrate uptake by soybean plants during interruption of the dark period with low intensity light

Diurnal patterns of net NO3- uptake by nonnodulated soybean [Glycine max (L.) Merr. cv. Ransom] plants growing in flowing hydroponic culture at 26 and 16 degrees C root temperatures were measured at hourly intervals during alternate days of a 12-day growth period. Ion chromatography was used to determine removal of NO3- from the culture solution. Day and night periods of 9 and 15 h were used during growth. The night period included two 6-h dark periods and an intervening 3-h period of night interruption by incandescent lamps to effect a long-day photoperiod and repress floral initiation. At both root temperatures, the average specific rates of NO3- uptake were twice as great during the night interruption period as during the day period; they were greater during the day period than during the dark periods; and they were greater during the dark period immediately following the day period than during the later dark period that followed the night interruption. While these average patterns were repetitious among days, measured rates of uptake varied hourly and included intervals of net efflux scattered through the day period and more frequently through the 2 dark periods. Root temperature did not affect the average daily specific rates of uptake or the qualitative relationships among day, dark and night interruption periods of the diurnal cycle.

Non-NASA Center↗
NASA NTRS2003

Global and Regional Decreases in Tropospheric Oxidants from Photochemical Effects of Aerosols

We evaluate the sensitivity of tropospheric OH, O3, and O3 precursors to photochemical effects of aerosols not usually included in global models: (1) aerosol scattering and absorption of ultraviolet radiation and (2) reactive uptake of HO', NO2, and NO3. Our approach is to couple a global 3-D model of tropospheric chemistry (GEOS- CHEM) with aerosol fields from a global 3-D aerosol model (GOCART). Reactive uptake by aerosols is computed using reaction probabilities from a recent review (gamma(sub HO2) = 0.2, gamma(sub NO2) = 10(exp -4), gamma(sub NO3) = l0(exp -3). Aerosols decrease the O3 - O((sup 1)D) photolysis frequency by 5-20% at the surface throughout the Northern Hemisphere (largely due to mineral dust) and by a factor of 2 in biomass burning regions (largely due to black carbon). Aerosol uptake of HO2 accounts for 10-40% of total HOx radical ((triple bonds)OH + peroxy) loss in the boundary layer over polluted continental regions (largely due to sulfate and organic carbon) and for more than 70% over tropical biomass burning regions (largely due to organic carbon). Uptake of NO2 and NO3 accounts for 10-20% of total HNO3 production over biomass burning regions and less elsewhere. Annual mean OH concentrations decrease by 9% globally and by 5-35% in the boundary layer over the Northern Hemisphere. Simulated CO increases by 5- 15 ppbv in the remote Northern Hemisphere, improving agreement with observations. Simulated boundary layer O3 decreases by 15- 45 ppbv over India during the biomass burning season in March and by 5-9 ppbv over northern Europe in August, again improving comparison with observations. We find that particulate matter controls would increase surface O3 over Europe and other industrial regions.

Martin, Randall V.↗
NASA NTRS2003

Aerosol Chemical Composition in Asian Continental Outflow during the TRACE-P Campaign: Comparison with PEM-West B

Aerosol associated soluble ions and the radionuclide tracers (7)Be and (210)Pb were quantified in 414 filter samples collected in spring 2001 from the DC-8 during the Transport and Chemical Evolution over the Pacific (TRACE-P) campaign. Binning the data into near Asia (flights from Hong Kong and Japan) and remote Pacific (all other flights) revealed large enhancements of NO3(-), SO4(-), C2O4(-), NH4(+), K(+), Mg2(+), and Ca2(+) near Asia. The boundary layer and lower troposphere were most strongly influenced by continental outflow, and the largest enhancements were seen in Ca2(+) (a dust tracer) and NO3(-) (reflecting uptake of HNO3 onto the dust). Comparing the TRACE P near Asia bin with earlier results from the same region during PEM-West B (in 1994) shows at least twofold enhancements during TRACE P in most of the ions listed above. Calcium and NO3(-) were most enhanced in this comparison as well (more than sevenfold higher in the boundary layer and threefold higher in the lower troposphere). Independent estimation of Asian emissions of gaseous precursors of the aerosol-associated ions suggest only small changes between the two missions, and precipitation fields do not suggest any significant difference in the efficiency of the primary sink, precipitation scavenging. It thus appears that with the possible exception of dust, the enhancements of aerosol-associated species during TRACE P cannot be explained by stronger sources or weaker sinks. We argue that the enhancements largely reflect the fact that TRACE P focused on characterizing Asian outflow, and thus the DC-8 was more frequently flown into regions that were influenced by well-organized flow off the continent.

Dibb, Jack E.↗
NASA NTRSDate not supplied

Double ChemFET for the In-Line Monitoring of Silver Dosing in Potable Water Systems

With NASA Advanced Exploration Systems (AES) Life Support Systems (LSS) baselining ionic silver (Ag+) as the biocide of choice, development in silver monitoring technologies becomes necessary to monitor and control Ag+ release. Ion-selctive field effect transistors (ISFETs) and chemically-sensitive field effect transistors (ChemFETs) are capable of selective detection of Ag+ with reversible and low detection limit responses. However, one major hurdle to ChemFET technologies is the requirement of a reference electrode, which can leak its fill solution into the potable water system and is prone to drift requiring frequent calibration. To circumvent this issue, we are developing a double chemically-sensitive field effect transistor (dChemFET). The dChemFET uses a second ChemFET to selectively monitor the counter ion and serves in place of the reference electrode. We report our work in developing the dChemFET, starting with the development of the Ag+ and NO3- ion selective memberanes (ISMs) to be used in the ChemFETs. The Ag+ ISM has a detection range of 50-105 ppb . The counter ion ISM, NO3- ISM, has shown a detection range of 400-105 ppb. NO3- ISMs are limited in detecting at lower ppb levels required for the dChemFET application on the potable water system. In response to this issue, we also report our studies in using the Ag+ ISM to measure deionized (DI) water as a reference measurement to be implemented in-line before the Ag+ is dosed.

Lance Dean Delzeit↗
NASA NTRSDate not supplied

Double ChemFET for the In-Line Monitoring of Silver Dosing in Potable Water Systems

With NASA Advanced Exploration Systems (AES) Life Support Systems (LSS)baselining ionic silver (Ag+) as the biocide of choice, development in silver monitoring technologies becomes necessary to monitor and control Ag+ release. Ion-selective field effect transistors (ISFETs) and chemically-sensitive field effect transistors (ChemFETs) are capable of selective detection of Ag+ with reversible and low detection limit responses. However, one major hurdle to ChemFET technologies is the requirement of a reference electrode, which can leak its fill solution into the potable water system and is prone to drift requiring frequent calibration. To circumvent this issue, a double chemically-sensitive field effect transistor (dChemFET) is proposed. The dChemFET uses a second ChemFET to selectively monitor the counter ion and serves in place of the reference electrode. This work reports on the development of the dChemFET, starting with the development of the Ag+ andNO3- ion selective membranes (ISMs) to be used in the ChemFETs. The Ag+ ISM was tested in 50-105 ppb Ag+ and showed linear, sub-Nernstian response. The NO3- ISM was tested in50-500 ppb silver ion equivalents of nitrate ion (Ag+ equiv. of NO3-) and shows linear, sub-Nernstian response as well . However, the Ag+ and NO3- ISMs face significant challenges in terms of drift that obstruct its application for long-term monitoring, but it can serve as a starting point for demonstrating the dChemFET proof of concept.

John Abdou↗
DOE OSTI2021

Gas-Phase Stability of Large Lanthanide:Ligand Clusters Evaluated Using Collision-Induced Dissociation

Introduction In the reprocessing of f-elements present in used nuclear fuels, a variety of diglycolamides (DGA’s) are used as extractants for actinide partitioning. In particular, the Actinide-Lanthanide Separation (ALSEP) process typically utilizes either the N,N,N’,N’-tetraoctyl diglycolamide (TODGA) or N,N,N',N'-tetra-2-ethylhexyl diglycolamide (T2EHDGA) extractant ligands following the partitioning of uranium and plutonium from used nuclear fuel. To better understand fundamental interactions in these processes, covalent bonding of several f-elements with diglycolamides, primarily TODGA, is investigated in the gas phase using nanospray ionization and a quadrupole time-of-flight mass spectrometer. Further, analysis of the identity and relative strength of the cluster is enabled by MS2 isolation and collision induced dissociation. Methods Metal ion cluster analysis was completed using a Bruker (Billerica, MA, USA) mircOTOF-Q II quadrupole time-of-flight mass spectrometer with a CaptiveSpray nanospray ion source. Detection was accomplished using positive ionization mode. Metal: ligand solutions were assembled as 30 µM europium nitrate, samarium nitrate, cerium nitrate, or holmium nitrate and 3 µM DGA in acetonitrile or a 50:50 mixture of acetonitrile: isopropanol. Preliminary data The samarium cluster experiments yielded clusters with a samarium:TODGA ratio of up to 1:7 able to be isolated and evidence of greater ratios present in the mass spectrum. This is surprising, as metal clusters are not expected to have a coordination space able to accommodate this many TODGA ligands, due to its size and tridenticity. Collisional activation of [Sm(TODGA)3]3+ suggested loss of a TODGA radical cation, in addition to ligand fragmentation. In contrast, activation of clusters with higher Sm:TODGA ratios resulted in loss of entire ligands, with no evidence of fragmentation. A lower collision energy was required to remove ligands as the number of bound TODGAs increased, suggesting that in larger clusters, ligands are more delicately complexed to the metal. In addition, several clusters were observed with the composition [Sm(NO3)x(TODGA)n x]+3 x. With a single nitrate ion, clusters with up to six TODGAs were able to be isolated. In a similar pattern to the samarium clusters containing only TODGA, less collision energy was required to eliminate one or more TODGAs with increasing size. Clusters with composition [Sm(NO3)(TODGA)n-1]2+ appeared in lower abundance and were more collisionally stable than [Sm(TODGA)n]3+ clusters. With two nitrate ions, only clusters with a single TODGA were able to be isolated. Analogous europium experiments resulted in similar clusters. Ratios of up to 1:7 Eu:TODGA and clusters with one nitrate and up to five TODGAs were isolated. In clusters with two nitrate ions, only one or two TODGAs were observed to be bound. Similar to samarium, MS2 experiments with the Eu clusters suggested that larger clusters required less collision energy to eliminate TODGA. Europium clusters with the composition [Eu(NO3)(TODGA)n-1]2+ were observed in greater abundance and with greater stability than the equivalent cluster with the composition [Eu(TODGA)n]3+. Novel Aspect These are the first reported Ln:TODGA clusters, allowing us to begin to investigate intrinsic complexation of lanthanides with process-relevant ligands.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗