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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2010

Nuclear Data Sheets for A = 30

Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for {sup 30}F, {sup 30}Ne, {sup 30}Na, {sup 30}Mg, {sup 30}Al, {sup 30}Si, {sup 30}P, {sup 30}S, and {sup 30}Cl. This evaluation for A=30 supersedes the previous evaluation 1998En04. However, some additional information for these nuclides can be found in earlier evaluations 1990En08 and 1978En02. Highlights of this publication are the following: The latest studies (2010StZZ, 2010De26) by fusion evaporation reaction of {sup 14}C and {sup 18}O using GAMMASPHERE array, consisted of 101 Compton-suppressed HPGe detectors, provided new data for {sup 30}Al, {sup 30}Si, and {sup 30}Mg nuclides and extended the level scheme to higher spin states. 2010Se07 reported a new level at 4814(3) keV for {sup 30}S nuclide studied by the {sup 32}S(p,t) reaction. It did not observe the 5168(6) keV level that was reported earlier as a possible doublet by 2007Ba69. In the absence of further experiment, 2010Se07 considers the level as one of the doublets.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2018

CO 2 -H 2 O capture and cyclability on sodium cobaltate at low temperatures (30-80 ºC); experimental and theoretical analysis

Sodium cobaltate (NaCoO2) was analyzed for CO 2 cyclic carbonation-decarbonation process at low temperatures (30–80 ºC) with relative humidity (RH) values between 0 and 80 %, using water vapor as catalytic intermediate. The presence of H 2 O clearly enhanced the CO 2 capture at T < 100 °C, compared to dry conditions, where the amount of CO 2 captured increased as a function of relative humidity. These improvements were attributed to NaHCO 3 and Na 2 CO 3 formation during carbonation. In the NaHCO 3 case, water vapor becomes part of carbonation, favoring reactivity. After the carbonation analysis, decarbonation process was analyzed using a N 2 flow, where results evidenced that only NaHCO 3 decomposition took place at low temperatures, producing NaOH and CO 2 . This result indicates that NaCoO 2 can be partially regenerated, suggesting a possible CO 2 cyclic carbonation. CO 2 carbonation–decarbonation tests were performed, confirming cyclic capacity and stability. Moreover, NaCoO 2 sample was modified adding different transition metals (Fe, Cu and Ni), trying to improve CO 2 -H 2 O sorption under similar physicochemical conditions. Results indicated that Fe-containing samples presented the best properties. Lastly, CO 2 partial pressure effect was analyzed on NaCoO 2 and Fe-containing samples using similar relative humidities.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2010

Evaluation of cytotoxicity and oxidative DNA damaging effects of di(2-ethylhexyl)-phthalate (DEHP) and mono(2-ethylhexyl)-phthalate (MEHP) on MA-10 Leydig cells and protection by selenium

Di(2-ethylhexyl)-phthalate (DEHP) is the most abundantly used phthalate derivative, inevitable environmental exposure of which is suspected to contribute to the increasing incidence of testicular dysgenesis syndrome in humans. Oxidative stress and mitochondrial dysfunction in germ cells are suggested to contribute to phthalate-induced disruption of spermatogenesis in rodents, and Leydig cells are one of the main targets of phthalates' testicular toxicity. Selenium is known to be involved in the modulation of intracellular redox equilibrium, and plays a critical role in testis, sperm, and reproduction. This study was aimed to investigate the oxidative stress potential of DEHP and its consequences in testicular cells, and examine the possible protective effects of selenium using the MA-10 mouse Leydig tumor cell line as a model. In the presence and absence of selenium compounds [30 nM sodium selenite (SS), and 10 {mu}M selenomethionine (SM)], the effects of exposure to DEHP and its main metabolite mono(2-ethylhexyl)-phthalate (MEHP) on the cell viability, enzymatic and non-enzymatic antioxidant status, ROS production, p53 expression, and DNA damage by alkaline Comet assay were investigated. The overall results of this study demonstrated the cytotoxicity and genotoxicity potential of DEHP, where MEHP was found to be more potent than the parent compound. SS and SM produced almost the same level of protection against antioxidant status modifying effects, ROS and p53 inducing potentials, and DNA damaging effects of the two phthalate derivatives. It was thus shown that DEHP produced oxidative stress in MA-10 cells, and selenium supplementation appeared to be an effective redox regulator in the experimental conditions used in this study, emphasizing the critical importance of the appropriate selenium status.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Regenerable solvents mediate accelerated low temperature CO 2 capture and carbon mineralization of ash and nano-scale calcium carbonate formation

The dual need to remove CO 2 from our emissions and treat alkaline industrial residues such as ash materials motivate the design of innovative pathways to simultaneously capture and convert CO 2 into mineralized carbonates. Direct carbon mineralization is one approach that addresses the need to simultaneously treat alkaline industrial residues and mineralize CO 2 emissions. Low CO 2 solubility in water and slow kinetics at ambient temperature have challenged the direct carbon mineralization of alkaline industrial residues. Here, to address these challenges, the use of CO 2 capture solvents that enhance CO 2 solubility and facilitate accelerated carbon mineralization of fly ash at temperatures below 90 °C is investigated. Calcium carbonate formation results in the inherent regeneration of the solvent. The carbon mineralization extents of non-calcium carbonate content in fly ash were 50% and 51% and in waste ash were 58% and 62% in 2.5 M sodium glycinate and 30 wt% MEA solutions, respectively. The experiments were performed at 50 °C for 3 hours with CO 2 partial pressure of 1 atm in a continuously stirred slurry environment with 15 wt.% solid. Furthermore, nanoscale CaCO 3 is successfully synthesized from dissolved calcium using CO 2 -loaded sodium glycinate and surfactants such as CTAB (Cetyl Trimethyl Ammonium Bromide). Surfactants such as CTAB bind to the calcium carbonate surface and regulate the growth of calcium carbonate particles. These innovative approaches demonstrate the feasibility of directly storing CO 2 in fly ash and waste ash as calcium carbonate and producing nanoscale calcium carbonate using regenerable CO 2 capture solvents.

42 ENGINEERING↗
DOE OSTI2022

Process development for recovering critical elements from acid mine drainage

The rapid development of advanced technologies has increased the demand for critical elements, such as Mn, Co, and Ni. For this work, a systematic study was conducted to develop a process for producing high-purity Mn, Co, and Ni products from an acid mine drainage (AMD). As major contaminants, Fe and Al in the solution were sequentially precipitated and eliminated by elevating the pH to around 4.00 and 6.50, respectively. After that, a pre-concentrated slurry containing 3,794 mg/L Mn, 59 mg/L Co, 127 mg/L Ni, and 300 mg/L Zn was obtained by collecting the precipitates formed in the pH range of 6.50 to 10.00. The pH of the pre-concentrated slurry was decreased to around 5.00 by adding HCl to re-dissolve Co, Ni, and Zn for further purification. At this pH, greater than 50% of Mn remained undissolved, and filtration of the undissolved material resulted in a product with around 30 wt.% Mn. Sodium sulfide was added into the re-dissolved solution to selectively precipitate Co, Ni, and Zn while remaining Mn in the solution. Almost 100% of Co, Ni, and Zn but only around 15% of Mn were precipitated using a sulfur to metal molar ratio of 1 at pH 4.00. The sulfide precipitate was calcined at 200 °C for 2 h and then completely dissolved in 1.2 M HCl. The critical elements existing in the dissolved solution were efficiently separated using a two-stage solvent extraction process. Ultimately, Co and Ni products with almost 94% and 100% purity were obtained by sulfide and alkaline precipitation, respectively.

42 ENGINEERING↗
DOE OSTI2018

Fungal spores as a source of sodium salt particles in the Amazon basin

Salt containing aerosols play important roles in atmospheric chemistry and cloud formation, hence understanding and observationally constraining their sources are vital. In the Amazon basin, particles containing mixed sodium salts are routinely attributed to marine aerosols transported from the Atlantic Ocean. Here, using detailed chemical imaging analysis, we show that fungal spores emitted by the forest biosphere contribute to at least 30% (by number) of sodium salt particles observed in the central Amazon basin. Hydration experiments, using environmental microreactors complemented with micro32 spectroscopy analysis, we show that sodium-containing fungal spores have higher hygroscopic growth than sodium-free spores and their sodium content determines their growth factors. Modeling results suggest that fungal spores account for ~62% of the total sodium mass during the wet season and that their fractional contribution increases during nighttime. In sharp contrast with the assumption that sodium-containing aerosols arise solely from marine sources, our results suggest that locally-emitted fungal spores containing sodium contribute substantially to the number and mass of coarse particles containing Na and Cl (similar to sea salt). Furthermore, their role in cloud formation and contribution to salt cycles and the terrestrial ecosystem in the Amazon basin warrant further consideration.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Fundamental Study on Effects of Borate on the Sorption of Cesium ions to Calcium Silicate Hydrate - 18068

The effects of borate on the formation of calcium silicate hydrate (C-S-H) and the Cs sorption behavior were examined by the sorption experiments without drying process. C-S-H was prepared by mixing calcium oxide, fumed silica, and sodium-borate solution in a glove bag filled with nitrogen gas. The volume of sodium borate solution was 30 mL, in order to adjust the liquid/solid weight ratio to 20. The Ca/Si molar ratio of C-S-H was adjusted so as to be 0.4, 0.8, 1.2, and 1.6. The concentration of sodium borate was set to the range from 0 to 600 mM in the sample solution. The solution of cesium chloride was added to the each sample for setting the initial concentration of Cs ions to 1 mM. The samples were cured in a shaking chamber at 298 K and 120 strokes/min during 7 days. In addition, for estimating the curing-period dependencies, the curing period was set to the range from 0.5 to 28 days for the condition of 0 M or 400 M sodium borate. In the results, under the conditions of the borate concentration up to 200 mM, the sorption behavior of Cs ions to C-S-H was hardly different from those without borate, while the sorption ratio of Cs ions for the borate concentration of 400 mM or more decreased by down to 46% compared with the blank samples. However, the sorption ratio of Cs ions in the case of 400 mM borate increased and reached as much as that for the blank sample until 28 days. Besides, the Raman spectra of solid phase showed that the peak derived from boric acid or borate (calcium borate or calcium borosilicate hydrate) appeared under the high concentration conditions of borate, and the peak of the silica chain of C-S-H was weakened. Considering the practical concentration of borate and much longer period for the performance assessment of the solidified wastes, the immobilization properties for Cs ions of cementitious materials contained borate will be kept appropriately in the disposal system for low-level wastes. (authors)

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Synthesis and Characterization of a Novel pH-Sensitive Aluminum Crosslinked Carboxymethyl Tragacanth Beads for Extended and Enteric Drug Delivery

Carboxymethyl tragacanth (CM-TG) with a DS of 1.2 was synthesized and characterized for drug delivery using diclofenac sodium as a model drug. The mixture of CM-TG and drug was ionically crosslinked using aluminum chloride to form drug-loaded beads. The concentrations of 10 and 20% w/w solution of CM-TG were found to produce beads with acceptable qualities. The beads exhibited pH-dependent swelling. The highest swelling was observed at pH 6.8 which evidences the possibility to release the drug in the colon. FT-IR and TGA confirmed carboxymethylation of tragacanth and the absence of drug-polymer interaction. The diclofenac sodium entrapment efficiency was 30–35% while the loading varies from 4.5 to 18% w/w based upon the drug-polymer ratio. The beads could extend the drug release up to 180 min at pH 6.8. The pH-responsive CM-TG hydrogel beads are biocompatible and could be exploited as a new excipient in developing enteric release formulations.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Simple but tricky: Investigations of terephthalic acid purity obtained from mixed PET waste

In this study, we report for the first time, the basic depolymerization of mixed waste-polyethylene terephthalate (PET) by hydrolysis and subsequent terephthalic acid monomer recovery at high purity using benign reaction conditions. Several conditions were tested for depolymerization such as PET chips size, concentration of aqueous sodium hydroxide (20 or 30%), organic co-solvent (ethylene glycol or ethanol), temperature at which the reaction was run and duration of the heating. More importantly, several batches of PET were utilized as starting materials including a commercial PET, chopped PET obtained from clean bottles whose caps and labels were removed and the purity of the product from each condition was evaluated via nuclear magnetic resonance (1HNMR and 13CNMR), differential scanning calorimetry (DSC) and powder Xray diffraction (XRD). Unsurprisingly, the conversion of PET is dependent on the particle size varying from 100% conversion for fine powder to 73% conversion for (300 µm, mesh 6 – 20 or mesh 14-20). Ethanol appears to be more efficient as a co-solvent than ethylene glycol, with higher PET depolymerization conversions (94% versus 75-80%), shorter reaction times (2h versus 6h) and lower temperatures (80 °C versus 110 °C). The terephthalic acid (TPA) recovered appeared to have only subtle differences among the batches, most notably a pink color when the reaction was run in ethanol/base. The DSC of the compounds produced in ethylene glycol water appear to display a melting point (280-288 °C) while the samples prepared in ethanol as well as a commercial sample did not. Overall, the purity of the various TPA batches is comparable, and similar to commercial TPA, demonstrating the utility of the method to depolymerize realistic waste streams. The method is simple, demonstrated on multigram scale (15-30g) and allows for the complete removal of waste other than PET unaffected by alkaline conditions.

Cosimbescu, Lelia↗
NASA NTRS1975

Third harmonic generation in phase-matched alkali metal vapors

We report improvements in conversion efficiency for third harmonic generation in sodium and rubidium vapor. 30-psec pulses of radiation at 1.064 micron have been converted to 0.3547 micron with an energy conversion efficiency of 10%. Factors limiting conversion efficiency are discussed.

Bloom, D. M.↗
DOE OSTI2025

FY24 Task 4: Studies of Phosphate and Fluoride Solubility for Dissolution of High Phosphate Tank Waste

Knowledge gaps have been identified in phosphate solubility in almost every single- and multi-component system, and particularly for aluminate in phosphate/hydroxide, where uncertainties in predicted values of aluminum solubility are greater than 50%. Solubility data of multicomponent, aqueous electrolytes containing sodium hydroxide, sodium fluoride, sodium phosphate, sodium nitrite, sodium nitrate, and dissolved gibbsite are also sparse. For example, for solutions of (i) sodium nitrate and sodium phosphate, data are only available at 30 and 50 °C, and for (ii) dissolved gibbsite in sodium hydroxide and sodium phosphate, only two data points are available at 20 and 40 °C. There is no data available on mixtures of sodium hydroxide, sodium phosphate, sodium fluoride, and dissolved gibbsite. These knowledge gaps were identified in a technical review of waste solubility data and the impact of dilution on solution stabilities and will be addressed in this work to predict aluminum hydroxide and sodium phosphate solubility in multicomponent electrolytes upon dilution, and upon variation of temperature. Results will provide the technical basis to develop accurate models for (i) gibbsite solubility and mass transfer of aluminum between solid and liquid forms following the sluicing of sludge and saltcake with water; and (ii) further blending of these suspensions with bismuth from bismuth phosphate waste, and zirconium and uranium left from the fuel decladding. This work will be essential to developing a disposition path for retrieval solutions from bismuth phosphate wastes. This effort would also support sludge washing to further reduce phosphate concentration if that process were to be added back to the flowsheet in the future.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS1979

Jovian sodium emission from Region C2

Observations of emission from sodium presumed to have been ejected from Io in the orbital plane of the Gallilean satellites and extending outward to at least 35 Jupiter radii are reported. Spectra of the sodium D line were observed to have an intensity of 20 to 30 R. Mechanisms for the escape of sodium from Io after sputtering from the surface are: (1) ejection from Io at velocities greater than Jupiter escape velocity, (2) ejection at velocities corresponding to orbits with apoapses of 35 Jupiter radii, and (3) ionization followed by magnetic field sweeping and recombination. The relative contributions of each mechanism are estimated and used to predict the sodium emission intensity at 35 Jupiter radii to be 7 to 8 R, a value considered to be in reasonable agreement with observations. Observations of emission line width and the correlation of intensity with the orbital phase of Io would provide further means of evaluating the proposed mechanisms of sodium ejection.

Pilcher, C. B.↗
DOE OSTI2014

Preparation of polyaniline/sodium alanate hybrid using a spray-drying process

Nowadays, hydrogen is highly interesting as an energy source, in particular in the automotive field. In fact, hydrogen is attractive as a fuel because it prevents air pollution and greenhouse emissions. One of the main problems with the utilization of hydrogen as a fuel is its on-board storage. The purpouse of this work was to develop a new hybrid material consisting of a polyaniline matrix with sodium alanate (NaAlH{sub 4}) using a spray-drying process. The polyaniline used for this experiment was synthesized by following a well-established method for the synthesis of the emeraldine base form of polyaniline using dodecylbenzenesulfonic acid as dopant. Micro particles of polyaniline/sodium alanate hybrids with 30 and 50 wt% of sodium alanate were prepared by using a spray-drying technique. Dilute solutions of polyaniline/sodium alanate were first prepared, 10g of the solid materials were mixed with 350 ml of toluene under stirring at room temperature for 24h and the solutions were dried using spray-dryer (Büchi, Switzerland) with 115°C of an inlet temperature. The hybrids were analyzed by differential scanning calorimetry, FT-IR and scanning electron microscopy (SEM). The addition of sodium alanate decreased the glass transition temperature of the hybrids when compared to neat polyaniline. FT-IR spectrum analysis was performed to identify the bonding environment of the synthesized material and was observed that simply physically mixture occurred between polyaniline and sodium alanate. The SEM images of the hybrids showed the formation of microspheres with sodium alanate dispersed in the polymer matrix.

08 HYDROGEN↗
NASA NTRS1997

Planetary Aeronomy and Related Studies

Mercury atmosphere - Sprague and Hunten, in collaboration with Katharina Lodders of Washington University, proposed, mainly on cosmochemical grounds, that S atoms are an important constituent of the atmosphere (30 times more abundant than sodium). This paper has appeared in Icarus. We also suggest that condensed sulfur is an excellent candidate for the radar-bright polar caps, more plausible than water ice because the latter is only barely stable even in permanently-shadowed craters. The best prospect for detection of the vapor is through its resonance lines, a triplet near 1814 A. Mercury is too close to the Sun to be observed by any existing space telescope, but there is some prospect that the search could be made from a Shuttle-based spectrograph such as Lyle Broadfoot's USTAR. Sprague and Hunten have completed an elaborate data analysis of over 100 measurements of the Na D lines, obtained with the 61-inch telescope and our echelle spectrograph. Full account has been taken of the radiative-transfer problem that arises because the Na atmosphere is not optically thin. The output of this code is used in another program that makes an elaborate inverse interpolation in two angles and optical depth and computes the effect of the seeing (always bad for Mercury). The seeing is determined by fitting cuts across a computed image to part of the spectrum adjacent to the sodium lines, and typically ranges from slightly less than 4 arcsec to worse than 6 (diameter at l/e of a Gaussian). The final result is a list of Na abundances, with some information on spatial distribution. One particularly interesting result of further analysis is a strong abundance maximum in the morning relative to the afternoon, confirming an earlier result for potassium, based on much fewer measurements. The analysis are completed during the extension of the present grant. This work depends heavily on the Hapke parameters used to estimate the reflectance of Mercury's surface. The paper by Domingue et al. examines the credibility of the available parameters, which are derived from disk-unresolved photometry, and concludes that errors in the derived Na abundances could be as great as 30%.

Hunten, D. M.↗
DOE OSTI2023

Tellurium Corrosion of Type 304/304L Stainless Steel, Iron, Chromium, and Nickel in High-Temperature Liquid Sodium

Investigating tellurium (Te) corrosion on structural materials is crucial for sodium-cooled fast reactors (SFRs) due to radionuclide presence and knowledge gaps. In this study, Type 304/304L stainless steel (SS304), chromium (Cr), iron (Fe), and nickel (Ni) samples were immersed in low-oxygen environments with Te in liquid sodium at 773 K for 30 days. At 10 ppm oxygen, SS304 showed multiple oxide layers, including a compact NaCrO 2 interlayer and porous Na-Fe-Ni-O outer layers. Tellurium penetrated through the porous layers but was hindered by the NaCrO 2 interlayer. At 0.01 ppm oxygen, Cr had no oxide layer, while Fe and Ni had unstable ones. Tellurium-induced pitting was deeper in Fe and Ni compared to Cr. Oxygen levels and Cr composition are critical factors affecting stable oxide compound layer formation and mitigating Te-induced pitting.

36 MATERIALS SCIENCE↗