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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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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Rotational excitation and de-excitation of magnesium mono-sulphide (MgS) by He collisions

ABSTRACT Magnesium mono-sulphide (MgS) plays a crucial role in astrochemical processes, particularly in the interstellar medium (ISM), where metal-sulphur chemistry influences molecular formation and evolution. This work presents a detailed study of the rotational excitation and de-excitation of MgS through collisions with helium (He) atoms, the second most abundant species in the ISM after hydrogen, which includes both atomic (H) and molecular forms (H2). The focus on MgS–He collisions arises from He's high abundance, chemical inertness, and simpler electronic structure, which make it well suited for quantum scattering calculations. These characteristics establish He as an ideal candidate for initial studies, providing fundamental data for future investigations involving H2. The study uses quantum scattering methods to calculate the collisional rate coefficients over a broad temperature range. These rates are critical for interpreting observational data on MgS and predicting its abundance in space. The interaction potential between MgS and He is calculated using the rigid rotor approximation and the Jacobi coordinate system, employing the CCSD(T)-F12a/aug-cc-pVTZ method for accurate two-dimensional potential energy surface. The study explores the anisotropic nature of the MgS–He interaction, which favours odd Δj rotational transitions at low collision energies. The inelastic cross-sections for rotational transitions involving up to 16 rotational levels of MgS were computed up to 1000 cm−1, enabling the calculation of rate coefficients up to 150 K for Δj = ±1, ±2, and ± 3 rotational transitions. The results show that Δj = 1 transitions dominate at low temperatures, while Δj = 2 transitions become more significant at higher temperatures. This study provides valuable data for interpreting future astrophysical observations of MgS. The findings also propose new rotational transitions for MgS detection in space, enhancing our ability to track and study this molecule in various cosmic environments.

Hendaoui, Hamza (ORCID:0000000218641872)↗
DOE OSTI2021

Caught in motion: human NTHL1 undergoes interdomain rearrangement necessary for catalysis

Abstract Base excision repair (BER) is the main pathway protecting cells from the continuous damage to DNA inflicted by reactive oxygen species. BER is initiated by DNA glycosylases, each of which repairs a particular class of base damage. NTHL1, a bifunctional DNA glycosylase, possesses both glycolytic and β-lytic activities with a preference for oxidized pyrimidine substrates. Defects in human NTHL1 drive a class of polyposis colorectal cancer. We report the first X-ray crystal structure of hNTHL1, revealing an open conformation not previously observed in the bacterial orthologs. In this conformation, the six-helical barrel domain comprising the helix-hairpin-helix (HhH) DNA binding motif is tipped away from the iron sulphur cluster-containing domain, requiring a conformational change to assemble a catalytic site upon DNA binding. We found that the flexibility of hNTHL1 and its ability to adopt an open configuration can be attributed to an interdomain linker. Swapping the human linker sequence for that of Escherichia coli yielded a protein chimera that crystallized in a closed conformation and had a reduced activity on lesion-containing DNA. This large scale interdomain rearrangement during catalysis is unprecedented for a HhH superfamily DNA glycosylase and provides important insight into the molecular mechanism of hNTHL1.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Sulfurospirillum diekertiae sp. nov., a tetrachloroethene-respiring bacterium isolated from contaminated soil

Two anaerobic, tetrachloroethene- (PCE-) respiring bacterial isolates, designated strain ACS DCE T and strain ACS TCE , were characterized using a polyphasic approach. Cells were Gram-stain-negative, motile, non-spore-forming and shared a vibrioid- to spirillum-shaped morphology. Optimum growth occurred at 30°C and 0.1–0.4% salinity. The pH range for growth was pH 5.5–7.5, with an optimum at pH 7.2. Hydrogen, formate, pyruvate and lactate as electron donors supported respiratory reductive dechlorination of PCE to cis-1,2-dichloroethene (cDCE) in strain ACS DCE T and of PCE to trichloroethene (TCE) in strain ACS TCE . Both strains were able to grow with pyruvate under microaerobic conditions. Nitrate, elemental sulphur, and thiosulphate were alternative electron acceptors. Autotrophic growth was not observed and acetate served as carbon source for both strains. The major cellular fatty acids were C 16:1 ω7c, C 16:0 , C 14:0 and C 18:1 ω7c. Both genomes feature a circular plasmid. Strains ACS DCE T and ACS TCE were previously assigned to the candidate species 'Sulfurospirillum acididehalogenans'. Here, based on key genomic features and pairwise comparisons of whole-genome sequences, including average nucleotide identity, digital DNA–DNA hybridization and average amino acid identity, strains ACS DCE T and ACS TCE , 'Ca. Sulfurospirillum diekertiae' strains SL2-1 and SL2-2, and the unclassified Sulfurospirillum sp. strain SPD-1 are grouped into one distinct species separate from previously described Sulfurospirillum species. Compared to Sulfurospirillum multivorans and Sulfurospirillum halorespirans, which dechlorinate PCE to cDCE without substantial TCE accumulation, these five strains produce TCE or cDCE as the end product. In addition, some cellular fatty acids (e.g., C 16:0 3OH, C 17:0 iso 3OH, C 17:0 2OH) were detected in strains ACS DCE T and ACS TCE but not in other Sulfurospirillum species. On the basis of phylogenetic, physiological and phenotypic characteristics, 'Ca. Sulfurospirillum acididehalogenans' and 'Ca. Sulfurospirillum diekertiae' are proposed to be merged into one novel species within the genus Sulfurospirillum, for which the name Sulfurospirillum diekertiae sp. nov. is proposed. Finally, the type strain is ACS DCE T (=JCM 33349 T = KCTC 15819 T =CGMCC 1.5292 T ).

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

Identifying Potential Geochemical and Microbial Impacts of Hydrogen Storage in a Deep Saline Aquifer

Hydrogen is valuable commodity and a promising energy carrier for variable energy production. Storage of hydrogen may occur through injection of hydrogen or a hydrogen/methane gas blend in subsurface reservoirs. However, the geochemical and biological reactions that may impact the stored hydrogen are not yet understood. Therefore, we collected samples from a deep storage aquifer located in the St. Peter Formation in southern Illinois. The reservoir material was primarily quartz with sulphur and iron deposits, while the major constituents of the fluid were chloride and sulphate. 16S rRNA gene amplicon sequencing revealed a low biomass microbial community that contained no obvious hydrogen-consuming bacteria. Next, we enriched a field sample to increase the biomass and completed a metagenomic analysis, finding a low number of genes present that are associated with hydrogen consumption. Then, we completed a series of reactor experiments under reservoir conditions with 15% H2/85% CH4 gas simulating a short-term hydrogen storage, high withdrawal scenario. We found minimal changes in the geochemistry or microbiology for the reactor experiments. This work suggests that short-term storage may be highly successful, although significant additional work needs to be completed in order to accurately evaluate the risks associated with long-term hydrogen storage scenarios. It is essential we continue to expand our understanding of the dynamics present in saline aquifers and provide new insights into how hydrogen storage may impact underground geological storage environments.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Untargeted metabolomics reveals anion and organ‐specific metabolic responses of salinity tolerance in willow

SUMMARY Willows can alleviate soil salinisation while generating sustainable feedstock for biorefinery, yet the metabolomic adaptations underlying their tolerance remain poorly understood.Salix miyabeanawas treated with two environmentally abundant salts, NaCl and Na 2 SO 4 , in a 12‐week pot trial. Willows tolerated salts across all treatments (up to 9.1 dS m −1 soil EC e ), maintaining biomass while selectively partitioning ions, confining Na + to roots and accumulating Cl − and in the canopy and adapting to osmotic stress via reduced stomatal conductance. Untargeted metabolomics captured >5000 putative compounds, including 278 core willow metabolome compounds constitutively produced across organs. Across all treatments, salinity drove widespread metabolic reprogramming, altering 28% of the overall metabolome, with organ‐tailored strategies. Comparing salt forms at equimolar sodium, shared differentially abundant metabolites were limited to 3% of the metabolome, representing the generalised salinity response, predominantly in roots. Anion‐specific metabolomic responses were extensive. NaCl reduced carbohydrates and tricarboxylic acid cycle intermediates, suggesting potential carbon and energy resource pressure, and accumulated root structuring compounds, antioxidant flavonoids, and fatty acids. Na 2 SO 4 salinity triggered accumulation of sulphur‐containing larger peptides, suggesting excess sulphate incorporation leverages ion toxicity to produce specialised salt‐tolerance‐associated metabolites. This high‐depth picture of the willow metabolome underscores the importance of capturing plant adaptations to salt stress at organ scale and considering ion‐specific contributions to soil salinity.

Plant Sciences↗
DOE OSTI2020

EARLY HAWAIIANS AND VOLCANIC HEAT

This research serves as the first-known compilation of accounts of early Hawaiians using volcanic heat. Western explorers in the 1800s wrote about native Hawaiians near $K\bar{i}lauea$ Volcano using volcanic heat for cooking and bathing. They cooked their food wrapped in leaves underground or above a steam crack at Sulphur Banks, $K\bar{i}lauea$ Iki, and the $N\bar{a}pau$ Crater Trail. Early Hawaiians bathed in the warm waters of Waiwelawela for health. To confirm the presence of volcanic heat, this study used geothermal resource maps by the Hawai‘i Play Fairway project. According to a probability map for volcanic heat, the areas where Hawaiians used volcanic heat have a probability of volcanic heat of 0.8 to 1.0. On a map with temperatures of water wells, water wells close to where Hawaiians used volcanic heat have elevated temperatures. Historically, the areas where Hawaiians used volcanic heat experienced volcanic steam release, volcanic eruptions, and lava flows.

Geology↗
DOE OSTI2020

The Nuclei Of Atoms In The Third Period Of The Periodic Table Of Elements (Monograph No.3)

Nuclei are shown for the elements sodium, magnesium, aluminum, silicon, phosphorus, sulphur, chlorine, and argon. Individual nucleons are not identified as protons or neutrons. Nucleons are illustrated using a sphere schematic of the wave functions of singular, linear, and tetrahedral nucleon arrangements. Nucleon arrangements in protium, deuteron, triton, helion, and alpha are shown as building blocks in the nuclei of elements in the third period of the periodic table of elements.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Boson Fermion Nuclei Energy Levels In The Third Period Of The Periodic Table Of Elements (Monograph No.5)

The boson fermion nucleus (BFN) energy level is shown for sodium, magnesium, aluminum, silicon, phosphorus, sulphur, chlorine, and argon. The BFN energy levels are compared to the energy levels in the shell nuclear model. Individual nucleon fermions in the BFN make minor contributions to the nucleus energy level. Nucleons rearrange into boson structures during stellar nucleosynthesis and condense into the lowest-level energy state. Deconstruction of the BFN structure and conversion to a shell or liquid-drop model brings about a higher energy state. This is not favored in nature.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Biomass Combustion in a Circulating Fluidized Bed Combustor

Interest in circulating fluidized bed (CFB) boilers as a power generation technology has skyrocketed in recent years because of several advantages this technology offers over conventional boilers, such as increased gas-solid mixing resulting in higher combustion efficiency and the ability to use lower quality fuels. CFB combustors are operated at lower temperatures than conventional thermal power generation combustors, thus reducing NO x emissions. SO 2 emissions are conveniently controlled through the addition of Ca-based sulphur sorbents within the combustor. This report summarizes the current modeling effort on a 50 kW th CFB combustor with a diameter of 10 cm and a height of 5 m; designed, built, and operated at CanmetENERGY in Ottawa, Canada employing the multiphase particle-in-cell (PIC) approach in the open-source Multiphase Flow with Interphase eXchanges (MFiX) Software Suite. The MFiX-PIC model parameters for the simulation are tuned against cold-flow experiments from CanmetENERGY using 9 kg of olivine sand as the inert bed material. It is shown that for the relatively coarse fluid meshes and large parcel sizes necessitated by the scale of the simulation, filter size dependent corrections to the drag law must be incorporated to ensure accuracy of the simulation results. The validated cold flow model is extended to simulate reacting flow with torrefied hardwood as the feedstock and to validate the combustion reaction scheme. The species concentrations at the riser outlet are compared against CanmetENERGY’s experiments and show satisfactory agreement. The simulations demonstrate the ability of MFiX-PIC to accurately capture the physics and chemistry of a circulating fluidized bed combustor at bench scales, which can be further extended to pilot- and industrial-scale systems.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2024

Engineered living materials for capture, conversion, and recycling technologies

Continued dependence on crude oil and natural gas resources for fossil fuels has caused global atmospheric carbon dioxide (CO 2 ) emissions to increase to record-setting proportions. There is an urgent need for efficient and inexpensive carbon sequestration systems to mitigate large-scale CO 2 emissions from industrial flue gas. Carbonic anhydrase (CA) has shown high potential for enhanced CO 2 capture applications compared to conventional absorption-based methods currently utilized in various industrial settings. This study aims to understand structural aspects that contribute to the stability of CA enzymes critical for their applications in industrial processes, which require the ability to withstand conditions different from their native environments. Here, we evaluated the thermostability and enzyme activity of mesophilic and thermophilic CA variants at different temperature conditions and in the presence of atmospheric gas pollutants like nitrogen oxides (NO x ) and sulphur oxides (SO x ). Based on our enzyme activity assays and molecular dynamics simulations, we see increased conformational stability and CA activity levels in thermostable CA variants incubated week-long at different temperature conditions. The thermostable CA variants also retained high levels of CA activity despite changes in solution pH due to increasing NO x and SO x concentrations. Furthermore, a loss of CA activity was observed only at high concentrations of NO x /SO x that possibly can be minimized with appropriate buffered solutions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Bryan Mound Collar Compression Study

This report presents a study of collar compression for the wells at the Bryan Mound site. The study includes a comprehensive review of all available Multi-Arm Caliper (MAC) logs from the site, which has been used to identify specific wells that are experiencing casing restrictions at collar joints. Additional site-wide analysis of Bryan Mound well temperature data, proximity to sulphur wells, pulsed eddy current (PEC) logs, and a general spatial analysis has been included.

02 PETROLEUM↗
NASA NTRS1970

Intumescent Coatings as Fire Retardants

Fire-retardant paint, when activated by the heat of fire, reacts to form a thick, low-density, polymeric coating or char layer. Water vapor and sulphur dioxide are released during the intumescent reaction.

Fish, R. H.↗
NASA NTRS1973

Research for applications of remote sensing to state and local governments (ARSIG)

Remote sensing and its application to problems confronted by local and state planners are reported. The added dimension of remote sensing as a data gathering tool has been explored identifying pertinent land use factors associated with urban growth such as soil associations, soil capability, vegetation distribution, and flood prone areas. Remote sensing within rural agricultural setting has also been utilized to determine irrigation runoff volumes, cropping patterns, and land use. A variety of data sources including U-2 70 mm multispectral black and white photography, RB-57 9-inch color IR, HyAC panoramic color IR and ERTS-1 imagery have been used over selected areas of Arizona including Tucson, Arizona (NASA Test Site #30) and the Sulphur Springs Valley.

Foster, K. E.↗
NASA NTRS1973

Grain boundary mobility in anion doped MgO

Certain anions OH(-), F(-) and Gl(-) are shown to enhance grain growth in MgO. The magnitude of their effect decreases in the order in which the anions are listed and depends on their location (solid-solution, second phase) in the MgO lattice. As most anions exhibit relatively high vapor pressures at sintering temperatures, they retard densification and invariably promote residual porosity. The role of anions on grain growth rates was studied in relation to their effect on pore mobility and pore removal; the atomic process controlling the actual rates was determined from observed kinetics in conjunction with the microstructural features. With respect to controlling mechanisms, the effects of all anions are not the same. OH(-) and F(-) control behavior through creation of a defect structure and a grain boundary liquid phase while Cl(-) promotes matter transport within pores by evaporation-condensation. Studies on an additional anion, S to the minus 2nd power gave results which were no different from undoped MgO, possibly because of evaporative losses during hot pressing. Hence, the effect of sulphur is negligible or undetermined.

Kapadia, C. M.↗
NASA NTRS1974

Optical properties of particles in planetary atmospheres - Laboratory studies

The laboratory techniques employed for the determination of optical constants are discussed briefly. The values obtained for the real n and imaginary k parts of the refractive indices of water, ice, and liquid ammonia are presented graphically. Work currently in progress on solid ammonia and on sulphuric acid is discussed. Other approaches to studies of the properties of aerosols in planetary atmospheres are presented briefly.

Williams, D.↗
NASA NTRS1975

Interpretation of Mariner 10 infrared observations of Venus

The infrared radiometer experiment on Mariner 10 measured limb-darkening curves for Venus in two spectral intervals, one near 11 microns and the other near 45 microns. These are analyzed in terms of the vertical opacity profile at each wavelength over a limited altitude range, approximately 60 to 80 km above the surface of the planet. Accurate multiple-scattering calculations are used to show that both opacity profiles are consistent with a model containing a cloud of sulphuric acid droplets with radii of 1.1 microns and a small amount of water vapor. Profiles of particle number density and humidity vs height are presented.

Taylor, F. W.↗