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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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A new solution-based synthesis method to produce a high quality Li 2 S–P 2 S 5 solid electrolyte was developed by using a strong nucleophile of LiC 2 H 5 .
In this work, the synthesis and characterization of a novel, low cost, amorphous wide-bandgap semiconductor via X-ray induced decomposition of strontium oxalate at high pressure have been demonstrated. By means of IR spectroscopy, the final product is identified as a mixture of strontium carbonate, strontium oxalate and CO-derived materials. Band gap measurements demonstrate that the final product exhibits a much lower band gap (2.45 eV) than the initial strontium oxalate powder (4.07 eV), suggesting that the synthesized material can be highly useful in electronic and optical applications.
A general synthesis method is demonstrated for producing PdM (M= Ag, Cu, Ni, and Y) nanowire networks. As a prototypical application, these nanowires are incorporated into polybenzimidazole to create mixed matrix membranes for H 2 /CO 2 separation.
A facile, scalable, wastewater-free synthesis of high energy density LiMn0.5Fe0.5PO4 (LMFP) cathodes with high electrode press density is achieved by employing the spinel LiMnFeO4 (LMFO) as a precursor.
Poly(acrylic acid) (PAA) and poly(vinylbenzoic acid) (PBA) were synthesized via reversible addition–fragmentation chain transfer (RAFT) polymerization and used as modulators for the synthesis of the metal–organic framework (MOF) UiO-66 (UiO = University of Oslo). Whereas typical syntheses of UiO-66 require large excesses of acid modulators, such as acetic acid or benzoic acid, to achieve controlled particle size and morphology of the resulting MOF particles, the use of polymerized acids allows for narrow particle size distributions at sub-stoichiometric quantities of modulator. Here, we show using scanning electron microscopy and dynamic light scattering techniques that polyacids can act as alternative modulators for the growth of UiO-66.
Irradiations of 239 Pu and 240 Pu targets with 48Ca beams aimed at the synthesis of Z=114 flerovium isotopes were performed at the Dubna Gas Filled Recoil Separator. A new spontaneously fissioning (SF) isotope 284 Fl was produced for the first time in the 240 Pu+ 48 Ca (250 MeV) and 239 Pu+ 48 Ca (245 MeV) reactions. The cross section of the 239 Pu( 48 Ca,3n) 284 Fl reaction channel was about 20 times lower than predicted by theoretical models and about 50 times lower than the maximum fusion-evaporation cross section for the 3n and 4n channels measured in the 244 Pu+ 48 Ca reaction. In the 240 Pu+ 48 Ca experiment, performed at 245 MeV in order to maximize the 3n-evaporation channel, three decay chains of 285 Fl were detected. The α-decay energy of 285 Fl was measured for the first time and decay properties of its descendants 281 Cn, 277 Ds, 273 Hs, 269 Sg, and 265 Rf were determined with higher accuracy. The assignment of SF events observed during the irradiation of the 240 Pu target with a 250 MeV 48 Ca beam to 284 Fl decay is presented and discussed. The cross sections at both 48 Ca energies are similar and exceed that observed in the reaction with the lighter isotope 239 Pu by a factor of 10. In conclusion, the decay properties of the synthesized nuclei and their production cross sections indicate a rapid decrease of stability of superheavy nuclei as the neutron number decreases from the predicted magic neutron number N = 184.
Abstract Permafrost thaw can alter the soil environment through changes in soil moisture, frequently resulting in soil saturation, a shift to anaerobic decomposition, and changes in the plant community. These changes, along with thawing of previously frozen organic material, can alter the form and magnitude of greenhouse gas production from permafrost ecosystems. We synthesized existing methane (CH 4 ) and carbon dioxide (CO 2 ) production measurements from anaerobic incubations of boreal and tundra soils from the geographic permafrost region to evaluate large‐scale controls of anaerobic CO 2 and CH 4 production and compare the relative importance of landscape‐level factors (e.g., vegetation type and landscape position), soil properties (e.g., pH, depth, and soil type), and soil environmental conditions (e.g., temperature and relative water table position). We found fivefold higher maximum CH 4 production per gram soil carbon from organic soils than mineral soils. Maximum CH 4 production from soils in the active layer (ground that thaws and refreezes annually) was nearly four times that of permafrost per gram soil carbon, and CH 4 production per gram soil carbon was two times greater from sites without permafrost than sites with permafrost. Maximum CH 4 and median anaerobic CO 2 production decreased with depth, while CO 2 :CH 4 production increased with depth. Maximum CH 4 production was highest in soils with herbaceous vegetation and soils that were either consistently or periodically inundated. This synthesis identifies the need to consider biome, landscape position, and vascular/moss vegetation types when modeling CH 4 production in permafrost ecosystems and suggests the need for longer‐term anaerobic incubations to fully capture CH 4 dynamics. Our results demonstrate that as climate warms in arctic and boreal regions, rates of anaerobic CO 2 and CH 4 production will increase, not only as a result of increased temperature, but also from shifts in vegetation and increased ground saturation that will accompany permafrost thaw.
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Co-gasification of biomass and coal in large-scale, Integrated Gasification Combined Cycle (IGCC) plants increases the efficiency and reduces the environmental impact of making synthesis gas ("syngas") that can be used in Coal-Biomass-to-Liquids (CBTL) processes for producing transportation fuels. However, the water-gas shift (WGS) and Fischer-Tropsch synthesis (FTS) catalysts used in these processes may be poisoned by multiple contaminants found in coal-biomass derived syngas; sulfur species, trace toxic metals, halides, nitrogen species, the vapors of alkali metals and their salts (e.g., KCl and NaCl), ammonia, and phosphorous. Thus, it is essential to develop a fundamental understanding of poisoning/inhibition mechanisms before investing in the development of any costly mitigation technologies. We therefore investigated the impact of potential contaminants (H 2 S, NH 3 , HCN, AsH 3 , PH 3 , HCl, NaCl, KCl, AS 3 , NH 4 NO 3 , NH 4 OH, KNO 3 , HBr, HF, and HNO 3 ) on the performance and lifetime of commercially available and generic (prepared in-house) WGS and FT catalysts.
The intergrowth of stable and metastable AgInS2 polymorphs was synthesized using a microwave-assisted synthesis. The samples were synthesized in water and in a deep eutectic solvent (DES) consisting of choline chloride and thiourea. An increase in the metal precursor concentration improved the crystallinity of the synthesized samples and affected the particle size. AgInS2 cannot be synthesized from crystalline binary Ag2S or In2S3 via this route. The solution synthesis reported here results in the intergrowth of the thermodynamically stable polymorph (space group I4¯2d, chalcopyrite structure) and the high-temperature polymorph (space group Pna21, wurtzite-like structure) that is metastable at room temperature. A scanning transmission microscopy (STEM) study revealed the intergrowth of tetragonal and orthorhombic polymorphs in a single particle and unambiguously established that the long-thought hexagonal wurtzite polymorph has pseudo-hexagonal symmetry and is best described with the orthorhombic unit cell. The solution-synthesized AgInS2 polymorphs intergrowth has slightly lower bandgap values in the range of 1.73 eV–1.91 eV compared to the previously reported values for tetragonal I4¯2d (1.86 eV) and orthorhombic Pna21 (1.98 eV) polymorphs.
A model is developed to describe the evolution of the protein synthesis system. The model is comprised of two independent autocatalytic systems, one including one gene (A-gene) and two activated amino acid polymerases (O and A-polymerases), and the other including the addition of another gene (N-gene) and a nucleotide polymerase. Simulation results have suggested that even a small enzymic activity and polymerase specificity could lead the system to the most accurate protein synthesis, as far as permitted by transitions to systems with higher accuracy.
Halobacterium saccharovorum synthesized ATP in response to a pH shift from 8 to 6.2. Synthesis was inhibited by carbonyl cyanide m-chloro-phenylhydrazone, dicyclohexylcarbodiimide, and azide. Nitrate, an inhibitor of the membrane-bound ATPase previously isolated from this organism, did not inhibit ATP synthesis. N-Ethymaleimide, which also inhibited this ATPase, stimulated the production of ATP. These observations suggested that H. saccharovorum synthesized and hydrolysed ATP using different enzymes and that the vacuolar-like ATPase activity previously described in H. saccharovorum was an ATPase whose function is yet to be identified.
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In this study, reaction steps of a process for synthesis of titanium oxycarbide from titanium slag were demonstrated. This process involves the reduction of titanium slag by a methane-hydrogen-argon mixture at 1473 K (1200 °C) and the leaching of the reduced products by hydrofluoric acid near room temperature to remove the main impurity (Fe{sub 3}Si). Some iron was formed by disproportionation of the main M{sub 3}O{sub 5} phase before gaseous reduction started. Upon reduction, more iron formed first, followed by reduction of titanium dioxide to suboxides and eventually oxycarbide.
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