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At least 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Vitrification of Hanford Tank 241-AP-105 Waste at 7 M Na and Equivalent Simulant

Hanford Site nuclear waste is to be vitrified at the Waste Treatment and Immobilization Plant (WTP), which is a part of the safe and efficient retrieval, treatment, and disposal mission of the U.S. Department of Energy Office of River Protection. Hanford tank 241-AP-105 (referred to herein as AP-105) is one of the initial Hanford radioactive tank wastes planned to be processed and vitrified. A portion of AP-105 waste was retrieved by Washington River Protection Solutions, LLC (WRPS) and transferred to Pacific Northwest National Laboratory (PNNL). The waste went through dilution by Columbia River water to reach a target sodium (Na) concentration of 7 M, solids filtration, and cesium removal by ion exchange. A glass composition was calculated from the Kim et al. glass models to satisfy the WTP baseline requirements based on the as-received sample and the target dilution to 7 M, from which a simulant was calculated and glass forming chemical (GFC) additions were determined to form a liquid/solids mixture called melter feed. To prepare for the processing of the 7 M Na AP-105 waste melter feed and learn about the production expectations, the melter feed simulant of 7 M Na AP-105 waste was processed in a non-radioactive, continuous laboratory-scale melter (CLSM) system.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

Effect of Cationic (Na + ) and Anionic (F – ) Co-Doping on the Structural and Electrochemical Properties of LiNi 1/3 Mn 1/3 Co 1/3 O 2 Cathode Material for Lithium-Ion Batteries

Elemental doping for substituting lithium or oxygen sites has become a simple and effective technique to improve the electrochemical performance of layered cathode materials. Compared with single-element doping, this work presents an unprecedented contribution to the study of the effect of Na + /F – co-doping on the structure and electrochemical performance of LiNi 1/3 Mn 1/3 Co 1/3 O 2 . The co-doped Li 1-z Na z Ni 1/3 Mn 1/3 Co 1/3 O 2-z F z (z = 0.025) and pristine LiNi 1/3 Co 1/3 Mn 1/3 O 2 materials were synthesized via the sol–gel method using EDTA as a chelating agent. Structural analyses, carried out by X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy, revealed that the Na + and F – dopants were successfully incorporated into the Li and O sites, respectively. The co-doping resulted in larger Li-slab spacing, a lower degree of cation mixing, and the stabilization of the surface structure, which substantially enhanced the cycling stability and rate capability of the cathode material. The Na/F co-doped LiNi 1/3 Mn 1/3 Co 1/3 O 2 electrode delivered an initial specific capacity of 142 mAh g –1 at a 1C rate (178 mAh g –1 at 0.1C), and it maintained 50% of its initial capacity after 1000 charge–discharge cycles at a 1C rate.

25 ENERGY STORAGE↗
DOE OSTI2020

Proton Decay of 21 Na for 20 Ne Energy Levels

The 24 Mg(p,α) 21 Na transfer reaction has been previously studied for a spectroscopic study of 21 Na. In this follow-up analysis, the proton decays of the excited states of the radionuclide 21 Na, which were measured simultaneously, are reported. By investigating the coincidence between the reaction α-particles and decay protons, we were able to identify three groups of events that are associated with the energy levels in 20 Ne. The 20 Ne excitation energy plot was obtained as a result. Here, the four lowest known energy levels in 20 Ne (the ground state and excited states at E x = 1.633, 4.247 and 4.966 MeV) were clearly observed.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
NASA NTRS1976

Interstellar absorption in intercloud regions. II - Detection of the Na I lines

The weak interstellar absorption lines of Na I, Ca II, and H I formed in the intercloud medium toward seven nearly unreddened stars are analyzed. Together with the widths of the Na I and Ca II lines, the Na I/H column-density ratios determine limits on the temperature of the absorbing gas, while the Ca II/H ratios establish limits on its calcium depletion. If the electron density is about 0.02 per cu cm in the absorbing regions, two of the seven temperatures are between 3200 K and 6000 K, while three others exceed lower limits ranging from 1400 K to 6500 A. The calcium depletions generally are less severe than in a typical cloud by at least an order of magnitude.

Hobbs, L. M.↗
NASA NTRS1978

Kinetic measurements of bone mineral metabolism: The use of Na-22 as a tracer for long-term bone mineral turnover studies

Sodium-22 was studied as a tracer for bone mineral metabolism in rats and dogs. When incorporated into bone during growth from birth to adulthood, the bone becomes uniformly tagged with (22)Na which is released through the metabolic turnover of the bone. The (22)Na which is not incorporated in the bone matrix is rapidly excreted within a few days when animals are fed high but nontoxic levels of NaCl. The (22)Na tracer can be used to measure bone mineral loss in animals during space flight and in research on bone disease.

Palmer, H. E.↗
NASA NTRS1979

The use of Na-22 as a tracer for long-term bone mineral turnover studies.

Sodium-22 has been studied as a tracer for bone mineral metabolism in rats and dogs. When incorporated into bone during growth from birth to adulthood, the bone becomes uniformly tagged with Na-22, which is released through the metabolic turnover of the bone. The Na-22 not incorporated in the bone matrix is rapidly excreted within a few days when animals are fed high, but nontoxic levels of NaCl. The Na-22 tracer can be used to measure bone mineral loss in animals during space flight and in research on bone disease.

Palmer, H. E.↗
NASA NTRS1980

Na+ and Ca2+ ingestion - Plasma volume-electrolyte distribution at rest and exercise

The effects of hypernatremia and hypercalcemia on plasma volume and electrolyte distribution during rest, exercise and recovery in cool and hot environments are investigated. Plasma volume, protein and electrolytes were measured in two groups of five men in the supine position during rest, exercise at 40-47% maximal oxygen consumption and recovery in 26.5 C and 39.4 C environments, after ingestion in the rest period of 16-17 ml/kg hypertonic NaCl, isotonic NaCl or hypertonic calcium gluconate solutions. During the rest period, it is found that the hypertonic Ca drink prevents any rise in plasma volume in both cool and hot environments, while hypertonic Na retarded hypervolemia only in the cool environment and consumption of both isotonic and hypertonic Na in the heat resulted in a hypervolemic response twice as great as that in the cool environment. During exercise and recovery, plasma volume is found to be greatest after drinking hypertonic Na in the heat, while the normal hypervolemic responses during exercise were not influenced by drink composition. Results suggest that hypertonic drinks may be better for maintaining plasma volumes during exercise in the heat.

Greenleaf, J. E.↗
NASA NTRS1984

Cellular localization of Na(+), K(+)-ATPase in the mammalian vestibular system

Two different, but complementary, procedures for cellular localization of Na+, K+-ATPase in the guinea pig vestibular system were employed. One of these techniques, devised by Stirling, depends upon the well documented ability of the specific inhibitor ouabain to bind selectively to Na+,K+-ATPase, blocking catalytic activity. Microdisected vestibular tissues are incubated with tritium-labelled (3H-) ouabain, and regions with a high concentration of Na+,K+-ATPase are subsequently identified by light microscope autoradiography. A second method, originated by Ernst, detects inorganic phosphate released from an artificial substrate (nitrophenyl phosphate) by catalytic activity of the enzyme. In the presence of strontium ion, phosphate is precipitated near regions of high activity, then converted to a product which may finally be visualized in the electron microscope. This cytochemical enzymatic reaction is inhibited by ouabain.

Kerr, T. P.↗
NASA NTRS1985

Molecular dynamics test of the Brownian description of Na(+) motion in water

The present paper provides the results of molecular dynamics calculations on a Na(+) ion in aqueous solution. Attention is given to the sodium-oxygen and sodium-hydrogen radial distribution functions, the velocity autocorrelation function for the Na(+) ion, the autocorrelation function of the force on the stationary ion, and the accuracy of Brownian motion assumptions which are basic to hydrodynamic models of ion dyanmics in solution. It is pointed out that the presented calculations provide accurate data for testing theories of ion dynamics in solution. The conducted tests show that it is feasible to calculate Brownian friction constants for ions in aqueous solutions. It is found that for Na(+) under the considered conditions the Brownian mobility is in error by only 60 percent.

Wilson, M. A.↗
NASA NTRS1987

Gamma-ray constraints on Na-22 yields in nova explosions

The longitudinal distribution of diffuse 1.275 MeV emission produced by the decay of interstellar Na-22 generated by a limited class of energetic novae-accreting ONeMg white dwarfs is modeled. The probability distributions for the locations of disk novae are derived as functions of Galactocentric cylindrical coordinates. The occurrence rate for novae of all classes in the Galactic disk is about 30/yr. An occurrence rate of about 16/yr is found for spheroid novae of all classes. By comparing these simulation results with HEAO 3 upper limits on diffuse 1.275 MeV emission, upper limits of (3-5.6) x 10 to the -7th solar mass are determined for the mean Na-22 yield for energetic novae generated by accreting ONeMg white dwarfs. These Na-22 limits constrain future models of explosive nucleosynthesis in energetic nova explosions.

Higdon, J. C.↗
NASA NTRS1988

Gamma-ray limits on Na-22 production in novae

Data accumulated from 1980 to 1987 by the gamma-ray spectrometer aboard the SMM are analyzed to search for annual increases at 1.275 MeV as evidence of Na-22 decay in the Galactic center region and in the ejecta of recent individual novae. No evidence of any 1.275 MeV emission of celestial origin is found. A limit of 3 x 10 to the -6th solar mass is placed on the accumulated Na-22 from many novae occurring near the Galactic center, and a limit of 7 x 10 to the -7th solar mass is placed on the mass of Na-22 ejected by the closest of the recent neon-rich novae.

Leising, Mark D.↗
NASA NTRS1990

Two-frequency lidar technique for mesospheric Na temperature measurements

This paper describes a new two-frequency lidar for measuring Na temperature profiles. The laser oscillator is tuned to the two operating frequencies by observing the Doppler-free structure of the Na D2 fluorescence spectrum in a vapor cell. The lidar technique and initial observations of the temperature profile between 82 and 102 km are described. Absolute temperature accuracies at the Na layer peak of better than + or - 3 K with a vertical resolution of 1 km and an integration period of approximately 5 min were achieved.

She, C. Y.↗
NASA NTRS1991

Further high-resolution Na I observations of the local interstellar medium

High-resolution absorption measurements of the interstellar Na I D lines at 5890 A observed toward 27 early-type stars in the local interstellar medium (LISM) are presented. These results are combined with other high-resolution sodium measurements to map the space distribution of neutral sodium column density for some 118 stars out to less than 200 pc. These measurements indicate an upper limit to the neutral sodium column density of log N(Na I) less than 10.0/sq cm can be inferred out to a distance of 50 pc in most directions in the LISM. Also, the rarefield region of the Local Bubble may extend beyond 60 pc in at least 35 percent of the directions sampled thus far. Evidence is shown for a ubiquitous, comoving vector for neutral NaI gas clouds in the LISM which is in a different direction to LISM vectors previously reported for more ionized local gas clouds. A comparison of the measured sodium columns with those of interstellar Ca II for a sample of 12 stars within 95 pc results in a ratio of Na I/Ca II less than 0.5 for most stars. This value implies that there could be warm, neutral gas with T of about 12,500 K beyond 50 pc in the LISM.

Welsh, B. Y.↗
NASA NTRS1993

Maintaining the Na atmosphere of Mercury

The possible sources of the Na atmosphere of Mercury are calculatively studied. The likely structure, composition, and temperature of the planet's upper crust is examined along with the probable flux of Na from depth by grain boundary diffusion and by Knudsen flow. The creation of fresh regolith is considered along with mechanisms for supplying Na from the surface to the exosphere. The implications of the calculations for the probable abundances in the regolith are discussed.

Killen, Rosemary M.↗
NASA NTRS1993

Optical studies of interstellar material in low density regions of the Galaxy. I - A survey of interstellar Na I and Ca II absorption toward 57 distant stars

We present high-resolution spectra of the Na I D and Ca II K lines toward 57 late-O and early-B stars along extended (d greater than 1 kpc) low-density paths through the Milky Way disk and halo. The sight lines preferentially sample diffuse gas in the interstellar medium (ISM) along interarm, Galactic center, and high latitude directions. We measure equivalent widths, apparent column densities, and absorption component structure. The Ca II to Na I ratios presented as a function of velocity for each sight line exhibit variations due to elemental depletion, ionization, and density enhancements. Absorption along high latitude sight lines is kinematically simpler than it is along interarm and Galactic center sight lines. Galactic rotation noticeably broadens the absorption profiles of distant stars located in these latter directions. Along several sight lines, we see Ca II absorption at velocities corresponding to large distances (/z/ about 1 kpc) from the Galactic plane. The effects of differences in the Ca II and Na I scale heights and nonzero velocity dispersions are readily apparent in the data. Brief notes are given for several sight lines with interesting absorption properties.

Sembach, K. R.↗
NASA NTRS1994

Semi-volatiles at Mercury: Sodium (Na) and potassium (K)

Several lines of evidence now suggest that Mercury is a planet rich in moderately-volatile elements such as Na and K. Recent mid-infrared spectral observations of Mercury's equatorial and mid-latitude region near 120 degrees mercurian longitude indicate the presence of plagioclase feldspar. Spectra of Mercury's surface exhibit spectral activity similar to labradorite (plagioclase feldspar with NaAlSi3O8: 30-50 percent) and bytownite (NaAlSi3O8: 10-30 percent). These surface studies were stimulated by the relatively large abundance of Na and K observed in Mercury's atmosphere. An enhanced column of K is observed at the longitudes of Caloris Basin and of the antipodal terrain. Extreme heating at these 'hot' longitudes and severe fracturing suffered from the large impact event could lead to enhanced outgassing from surface or subsurface materials. Alternatively, sputtering from a surface enriched in K could be the source of the observed enhancement. Recent microwave measurements of Mercury also give indirect evidence of a mercurian regolith less FeO-rich than the Moon. An anomalously high index of refraction derived from the whole-disk integrated phase curve of Danjon may also be indicative of surface sulfides contributing to a regolith that is moderately volatile-rich. The recent exciting observations of radar-bright spots at high latitudes also indicate that a substance of high volume scattering, like ice, is present in shadowed regions. Other radar-bright spots have been seen at locations of Na enhancements on the atmosphere. All combined, these pieces of evidence point to a planet that is not severely depleted in volatiles or semi-volatiles.

Sprague, A.↗
NASA NTRS1994

The local distribution of Na I interstellar gas

We present high-resolution absorption measurements (lambda/Delta lambda approximately 75,000) of the interstellar Na I D lines at 5890 A toward 80 southern hemisphere early-type stars located in the local interstellar medium (LISM). Combining these results with other sodium measurements taken from the literature, we produce galactic maps of the distribution of neutral sodium column density for a total of 293 stars generally lying within approximately 250 pc of the Sun. These maps reveal the approximate shape of the mid-plane contours of the rarefied region of interstellar space termed the Local Bubble. Its shape is seen as highly asymmetric, with a radius ranging from 30 to 300 pc, and with an average radius of 60 pc. Similar plots of the Galactic mid-plane distribution of sources emitting extreme ultraviolet radiation show that they also trace out similar contours of the Local Bubble derived from Na I absorption measurements. We conclude that the Local Bubble absorption interface can be represented by a hydrogen column density, Nu(sub ETA) = 2 x 10(exp 19) cm(exp -2), which explains both the local distribution of Na I absorption and the observed galactic distribution of extreme ultraviolet sources. The derived mid-plane contours of the Bubble generally reproduce the large-scale features carved out in the interstellar medium by several nearby galactic shell structures.

Welsh, B. Y.↗
DOE OSTI2020

Materials Data on Na(CuS)4 by Materials Project

Na(CuS)4 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Na1+ is bonded to six equivalent S2- atoms to form NaS6 octahedra that share corners with six equivalent CuS4 tetrahedra and edges with six equivalent NaS6 octahedra. All Na–S bond lengths are 2.93 Å. There are two inequivalent Cu+1.75+ sites. In the first Cu+1.75+ site, Cu+1.75+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with three equivalent NaS6 octahedra, corners with three equivalent SCu3S tetrahedra, and corners with six equivalent CuS4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. There are three shorter (2.33 Å) and one longer (2.34 Å) Cu–S bond lengths. In the second Cu+1.75+ site, Cu+1.75+ is bonded in a trigonal planar geometry to three equivalent S2- atoms. All Cu–S bond lengths are 2.23 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to three equivalent Cu+1.75+ and one S2- atom to form SCu3S tetrahedra that share corners with three equivalent CuS4 tetrahedra and corners with six equivalent SCu3S tetrahedra. The S–S bond length is 2.11 Å. In the second S2- site, S2- is bonded in a 7-coordinate geometry to three equivalent Na1+ and four Cu+1.75+ atoms.

36 MATERIALS SCIENCE↗