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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS2019

Cardiopulmonary Inflammatory Response to Meteorite Dust Exposures - Implications for Human Health on Earth and Beyond

This year marks the 50th anniversary of Apollo 11, the first time humans set foot on the Moon. The Apollo missions not only help answer questions related to our solar system, they also highlight many hazards associated with human space travel. One major concern is the effect of extraterrestrial dust on astronaut health. In an effort to expand upon previous work indicating lunar dust is respirable and reactive, the authors initiated an extensive study evaluating the role of a particulate’s innate geochemical features (e.g., bulk chemistry, internal composition, morphology, size, and reactivity) in generating adverse toxicological responses in vitro and in vivo. To allow for a broader planetary and geochemical assessment, seven samples were evaluated: six meteorites from either the Moon, Mars, or Asteroid 4 Vesta and a terrestrial basalt analogue. Even with the relatively small geochemical differences (all samples basaltic in nature), significant difference in cardiopulmonary inflammatory markers developed in both single exposure and multiple exposure studies. More specifically: 1) the single exposure studies reveal relationships between toxicity and a meteorite sample’s origin, its pre-ejected state (weathered versus un-weathered), and geochemical features (e.g. bulk iron content) and 2) multiple exposure studies reveal a correlation with particle derived reactive oxygen species (ROS) formation and neutrophil infiltration. Extended human exploration will further increase the probability of inadvertent and repeated exposures to extraterrestrial dusts. This comprehensive dataset allows for not only the toxicological evaluation of extraterrestrial materials but also clarifies important correlations between geochemistry and health. The utilization of an array of extraterrestrial samples from Moon, Mars, and asteroid 4Vesta will enable the development of a geochemical based toxicological hazard model that can be used for: 1) mission planning, 2) rapid risk assessment in cases of unexpected exposures, and 3) evaluation of the efficacy of various in situ techniques in gauging surface dust toxicity. Furthermore, by better understanding the importance of geochemical features on exposure related health outcomes in space, it is possible to better understand of the deleterious nature of dust exposure on Earth.

Harrington, A. D.↗
NASA NTRS1978

Stratospheric trace gas sampling with chemical absorption filters

Recent interest in stratospheric chemistry, sparked in part by the suggested roles of atomic chlorine (Cl) and nitrogen oxides (NOx) in the catalytic destruction of ozone (O3), has made sampling and measurement of trace constituents above the tropopause highly desirable. An ongoing research program in the In Situ Studies Project at the National Center for Atmospheric Research carries out aircraft and balloon-borne stratospheric chemical sampling at regular intervals by using chemically impregnated filters to collect particles and reactive gases.

Bonelli, J. E.↗
NASA NTRS1990

Simulation studies of plasma waves in the electron foreshock - The transition from reactive to kinetic instability

Particle simulation experiments were used to analyze the electron beam-plasma instability. It is shown that there is a transition from the reactive state of the electron beam-plasma instability to the kinetic instability of Langmuir waves. Quantitative tests, which include an evaluation of the dispersion relation for the evolving non-Maxwellian beam distribution, show that a quasi-linear theory describes the onset of this transition and applies again fully to the kinetic stage. This stage is practically identical to the late stage seen in simulations of plasma waves in the electron foreshock described by Dum (1990).

Dum, C. T.↗
DOE OSTI2025

Influence of Gel Formation on the Heterogeneous Oxidation of Organic Aerosol

Recent work has shown that divalent cations can perturb the viscosity and phase state of oxygenated organic particles in unexpected ways, sometimes leading to the formation of gel states. Despite the prevalence of divalent cations and oxygenated organic molecules in atmospheric aerosol, particularly in marine environments, the influence of gel states on the reaction rates is not well established. Here, in this work, we measure and compare the impact of viscosity and gel formation on the ozonolysis chemistry of aerosol particles containing the unsaturated, oxygenated organic species ascorbic acid (AA). AA serves as an excellent proxy compound for highly oxidized molecules in the atmosphere. We measured the hygroscopic growth, phase state, viscosity, and water diffusion rate in binary particles containing AA and water and in ternary particles with an additional co-solute of either ammonium sulfate or CaCl 2 . These measurements reveal gel formation in particles mixed with CaCl 2 , as particles become rigid but allow for relatively rapid diffusion rates of water, consistent with previous observations of gel behavior. We measured the rate of ozonolysis of these particles under a range of relative humidity (RH) conditions, showing a clear decrease in the rate with decreasing RH, consistent with the increase in viscosity and slowed diffusion. Notably, we measured the rate of ozonolysis of particles existing in a gel state, showing that following an initial period of decay, the rate of reaction arrests, indicating that the organic material in the solid state is protected from the reaction. This work shows that viscous particles and gel particles exhibit different reactivity toward heterogeneous oxidants, with significant implications for how we understand the chemical evolution of aerosol particles in the atmosphere.

gels↗
NASA NTRS1985

Decomposition of ethylene on small Pd particles

New results have been obtained which contribute to the understanding of hydrocarbon reactions on the surface of highly dispersed metal systems. Small particle of Pd were grown by electron beam evaporation on cleavage planes of high purity natural mica under ultrahigh vacuum conditions. Samples were subsequently characterized by transmission electron microscopy. Average particle sizes ranged from about 1 to 10 nm diameter. The chemisoption and decomposition of C2H4 on the Pd particles was studied using Auger electron spectroscopy and flash thermal desorption. It is shown that (a) C2H4 decomposes on Pd particles at room temperature, (b) specific surface sites are causing decomposition, and (c) the proportion of such active sites is significantly greater for the smaller metal particles. This enhanced reactivity may be due to an increase in the density of step, corner, and edge sites with a decrease in particle size.

Durrer, W. G.↗
DOE OSTI2024

Aircraft Measurements from a U.S. Western Wildfire Demonstrating Day and Night Differences in the Chemical Composition and Optical Properties of Biomass Burning Aerosols and Their Atmospheric Evolution

The composition and transformations of biomass burning aerosols (BBA) have been measured onboard the NOAA Twin Otter research aircraft during the Fire Influence on Regional to Global Environments and Air Quality field study. Here, we analyze real-time aerosol mass spectrometry measurements across three flights during the afternoon, late afternoon, and night of August 28, 2019, for one midsized wildfire. Analysis of several metrics showed that the aerosol composition and optical properties varied depending on the burning conditions at the fire zone and the time of day the BBA was emitted, with substantial variations in the available sunlight. The total aerosol mass loadings were dominated by organic components with a much smaller contribution from inorganic species. A gradual buildup of organic material was observed during the afternoon as the plume aged, indicating the condensation of photochemically formed low-volatility oxidized organic compounds. Highly hygroscopic ammonium nitrate was the main inorganic component, suggesting potential water content in BBA particles and the likelihood of their aqueous-phase reactivity. Depletions of particle-phase NO 3 – and Cl – relative to carbon monoxide were observed in the late afternoon and nighttime plumes, respectively, aligning with known gas-particle partitioning thermodynamics and the heterogeneous chemistry of dissolved nitrate and chloride. The wavelength-dependent light absorption by aerosol species was higher for the plume sampled at night and showed no significant changes with plume age, despite observed trends in composition and mass downwind. These differences in particle composition and optical properties demonstrate that the processes involved in BBA aging are not uniform for the same wildfire over the course of the day and depend highly on when the BBA was emitted, as well as the burning phase at the emissions source.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Tuning Catalytic Reactivity via Wetting Control through Oxygen Vacancies: Ru Clusters on Anatase TiO 2 and CeO 2 Supports

The shape of supported metal particles regulates their catalytic reactivity and is determined by the degree of wetting between the metal particle and the support surface. Flattened particles that wet support surfaces were reported in various catalytic systems, particularly in the subnanometer size regime. Such consequential metal–support wetting phenomena are poorly understood, and methods to study them on powder catalysts under realistic conditions are lacking. Here, we investigate the size-dependent wetting behaviors of Ru particles on two reducible-oxide supports, anatase TiO 2 (TiO 2 -A) and CeO 2 , under reducing catalytic conditions. X-ray absorption spectroscopy (XAS), low-energy ion scattering (LEIS), and density functional theory (DFT) are combined to determine the shape of Ru particles. Ru particles remain three-dimensional without wetting the TiO 2 -A support within the coverage range studied (0.06–0.98 Ru nm –2 ). In contrast, at low coverages (<0.25 Ru nm –2 ), Ru wets the CeO 2 support to form flat, disordered structures. The higher wettability of CeO 2 than TiO 2 -A is attributed to oxygen vacancies in the near-surface region. The shape difference between small Ru particles or clusters on the two supports leads to drastically contrasting catalytic reactivities in polyolefin hydrogenolysis, despite similar diameters. As a result, this work highlights the implications of metal–support wetting, or cluster shape, on catalytic behaviors of small metal clusters, while establishing the foundation for future systematic studies of such a phenomenon in realistic systems, by delivering a multitechnique methodology and revealing governing fundamental principles.

42 ENGINEERING↗
NASA NTRS2003

Carbon Nanotube Synthesis in a Flame with Independently Prepared Laser-Ablated Catalyst Particles

Laser ablation has been used ex situ to create metal nanoparticles for introduction into a reactive pyrolysis flame. By prior synthesis of the metal nanoparticles, the effects of the reactive gases can be clearly separated from the pyrolysis chemistry of a solvent carrier, as when nebulized solutions are used. Moreover, varying reactivity issues associated with particle growth and size are bypassed. Our results show that Fe selectively reacts with CO to produce nanotubes, whereas Ni selectively reacts with C2H2 to produce nanofibers. These observations are interpreted through the donation and withdrawal of electron density between the adsorbate's molecular orbitals and surface atoms of the metal nanoparticle. The rate of reaction of Ni with only C2H2 is found to be greater than the rate with C2H2 and CO. This suggests that CO inhibits the Ni-catalyzed reaction.

Nanotubes, Carbon/chemistry/ultrastructure↗
DOE OSTI2024

Synergetic Effects of Soil Organic Matter Components During Interactions with Minerals

Mineral-associated soil organic matter (SOM) is critical for stabilizing organic carbon and mitigating climate change. However, mineral-SOM interactions at the molecular scale, particularly synergetic adsorption through organic-organic interaction on the mineral surface known as organic multilayering, remain poorly understood. This study investigates the impact of organic multilayering on mineral-SOM interactions, by integrating macroscale experiments and molecular-scale simulations that assess the individual and sequential adsorption of major SOM compounds – lauric acid (lipid), pentaglycine (amino acid), trehalose (carbohydrate), and lignin onto soil minerals. Ferrihydrite, Al-hydroxide, and calcite are exposed to SOM compounds to determine adsorption affinities and binding energies. Results show that lauric acid has 20-40 times higher K d than pentaglycine, following the order K d (ferrihydrite) > K d (Al-hydroxide) >> K d (calcite). Molecular-scale simulations confirm that lauric acid has a higher binding energy (30.8 kcal/mol) on ferrihydrite than pentaglycine (6.0 kcal/mol), attributed to lipid hydrophobicity. The lower binding energy of pentaglycine results from its hydrophilic amide groups, facilitating partitioning into water. Sequential experiments examine how the first layer of lipid or amino acid affects the adsorption of carbohydrate/lignin, which show little or no individual adsorption affinities. Macroscale results reveal that lipid and amino acid adsorption induce ferrihydrite particle repulsion increasing reactive surface area and enhancing carbohydrate/lignin adsorption independently and synergistically through organic multilayering. Molecular-scale results reveal that amino acid adsorbed on ferrihydrite interacts more readily with lignin macroaggregates (preformed in solution) than with individual lignin units, indicating organic multilayering via H-bonding. Further, these findings reveal the molecular mechanisms of SOM-mineral interactions, crucial for enhancing soil carbon stabilization.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1984

Interactions of the marine phosphorus and carbon cycles

About 30 to 50% of the fluvial P-input to the oceans derives from release of reactive-P from particles during their passage through estuaries. The input is matched by P-removal into three approximately equivalent sink: (1) burial in phosphorites on productive shelves; (2) burial with (org) in the deep-sea; and (3) burial with biogenic calcite in the deep-sea. The P/C burial ratio in these three phases is very different: P/C (org) approximately .004; P/C (CaCO3) approximately .001; and P/C (PHOS) approximately .03. The removal mechanisms are all coupled to primary production in the surface ocean, but the details of the feedback mechanisms controlling the steady-state nutrient and carbon budgets in the sea are doscured by lack of knowledge of how the P/C ratios in the sinks adjust, and how shifts in oceanic nutrients affect oceanic ecology and the relative fraction of biogenic CaCO3 and (org) production.

Froelich, P. N.↗
NASA NTRS2001

Environmental Impact Overview

Aircraft emissions are deposited throughout the atmosphere, and at the lower stratosphere and upper troposphere they have greater potential to change ozone abundance and affect climate. There are significant uncertainties arising from the incomplete knowledge of the composition and evolution of the exhaust emissions, particularly regarding reactive trace species, particles, and their gaseous precursors. NASA Glenn Research Center at Lewis Field has considered its role in answering these challenges and has been committed to strengthening its aerosol/particulate research capabilities with initial emphasis on establishing advanced measurement systems and a particulate database. Activities currently supported by the NASA Ultra-Efficient Engine Technology (UEET) Program and accomplishment up to date will be described.

Peddie, Catherine↗
NASA NTRS2020

The interactive global fire module pyrE (v1.0)

Fires affect the composition of the atmosphere and Earth’s radiation balance by emitting a suite of reactive gases and particles. An interactive fire module in an Earth system model (ESM) allows us to study the natural and anthropogenic drivers, feedbacks, and interactions of open fires. To do so, we have developed pyrE, the NASA GISS (Goddard Institute for Space Studies) interactive fire emissions *module. The pyrE module is driven by environmental variables like flammability and cloud-to-ground lightning, calculated by the GISS ModelE ESM, and parameterized by anthropogenic impacts based on population density data. Fire emissions are generated from the flaming phase in pyrE (active fires). Using pyrE, we examine fire occurrence, regional fire suppression, burned area, fire emissions, and how it all affects atmospheric composition. To do so, we evaluate pyrE by comparing it to satellite-based datasets of fire count, burned area, fire emissions, and aerosol optical depth (AOD). We demonstrate pyrE’s ability to simulate the daily and seasonal cycles of open fires and resulting emissions. Our results indicate that interactive fire emissions are biased low by 32 %–42 %, depending on emitted species, compared to the GFED4s (Global Fire Emissions Database) inventory. The bias in emissions drives underestimation in column densities, which is diluted by natural and anthropogenic emissions sources and production and loss mechanisms. Regionally, the resulting AOD of a simulation with interactive fire emissions is underestimated mostly over Indonesia compared to a simulation with GFED4s emissions and to MODIS AOD. In other parts of the world pyrE’s performance in terms of AOD is marginal to a simulation with prescribed fire emissions.

Fires↗
NASA NTRS2009

Understanding the Reactivity of Lunar Dust for Future Lunar Missions

During the Apollo missions, dust was found to cause numerous problems for various instruments and systems. Additionally, the dust may have caused momentary health issues for some of the astronauts. Therefore, the plan to resume robotic and manned missions to the Moon in the next decade has led to a renewed interest in the properties of lunar dust, ranging from geological to chemical to toxicological. An important property to understand is the reactivity of the dust particles. Due to the lack of an atmosphere on the Moon, there is nothing to protect the lunar soil from ultraviolet radiation, solar wind, and meteorite impacts. These processes could all serve to activate the soil, or produce reactive surface species. On the Moon, these species can be maintained for millennia without oxygen or water vapor present to satisfy the broken bonds. Unfortunately, the Apollo dust samples that were returned to Earth were inadvertently exposed to the atmosphere, causing them to lose their reactive characteristics. In order to aid in the preparation of mitigation techniques prior to returning to the Moon, we measured the ability of lunar dust, lunar dust simulant, and quartz samples to produce hydroxyl radicals in solution[1]. As a first approximation of meteorite impacts on the lunar surface, we ground samples using a mortar and pestle. Our initial studies showed that all three test materials (lunar dust (62241), lunar dust simulant (JSC-1Avf), and quartz) produced hydroxyl radicals after grinding and mixing with water. However, the radical production of the ground lunar dust was approximately 10-fold and 3-fold greater than quartz and JSC-1 Avf, respectively. These reactivity differences between the different samples did not correlate with differences in specific surface area. The increased reactivity produced for the quartz by grinding was attributed to the presence of silicon- or oxygen-based radicals on the surface, as had been seen previously[2]. These radicals may also play a part in the reactivity of the lunar dust and lunar simulant. However, other factors would seem to be required to account for the greatly increased reactivity of the lunar soil. It was proposed that nanometer-size Fe 0 (zero valent) particles in the lunar soil might play a role, as they are not present in quartz or lunar dust simulant. The present work has been performed with the aim of understanding the origin of the considerable reactivity of lunar dust[3]. We have ground 8 lunar soils of varying maturity and source (highland or mare) and measured the hydroxyl-radical production and decay of the reactivity. It was determined that there is a direct correlation between the reactivity and the amount of nanophase metallic iron particles (as a function of soil maturity, I s/FeO, in which Is is the amount of iron present as nanophase iron particles present and FeO is the total iron content) in the samples; thus, the highland soils, with their lesser total FeO content, are less reactive than ground mare soils. Additionally, grinding of nanophase iron simulant [4] showed reactivity in line with the lunar soils and much greater than lunar dust simulant or quartz. Studies aimed at determining the time required to deactivate the reactive soils in a habitable environment showed that the average time to reach 50% of the initial reactivity was approximately 3.5 hours. However, even after one week, none of the soils had returned completely to its unground level of reactivity. In contrast to the reactivity results, there was no obvious correlation between the maturity of the soil and its deactivation time. These results provide the first chemical reactivity and persistence values as an important property of lunar soils, data that is paramount as mankind prepares to return to the Moon.

Wallace, William↗
NASA NTRS1976

Gas interaction effects on lunar bonded particles and their implications

Results are reported for an experimental investigation of gas-interaction effects on different Apollo 11 and Apollo 12 lunar-soil samples containing bonded particles. In the experiments, lunar fines were exposed to pure O2, pure water vapor, HCl, NH3, N2, HCOOH, and CH3NH2, in order to observe whether bonded particles would separate. In addition, repeated gas adsorption/desorption measurements were performed to determine the nature and reactive properties of the particle surfaces, and surface areas were measured for comparison with analogous terrestrial samples to determine whether the surface areas of highly radiation-damaged particles were larger or smaller. It is found that N2 is apparently ineffective in separating bonded particles and that the ratio of Apollo 11 to Apollo 12 bonded particles separated by a particular gas exposure ranges from 2.5 to 3.0. Possible reasons for differences in material surface properties at the two Apollo sites are considered, and it is concluded that material from a certain depth at some other site was transported to the Apollo 12 site and mixed with the original material in recent years (considerably less than 2000 years ago).

Mukherjee, N. R.↗
NASA NTRS1998

Particle Engulfment and Pushing by Solidification Interfaces: Ground Experiments - Part 1

Directional solidification experiments have been carried out to determine the pushing/engulfment transition for two different metal/particle systems. The systems chosen were aluminum/zirconia particles and zinc/zirconia particles. Pure metals (99.999% Al and 99.95% Zn) and spherical particles (500 microns in diameter) were used. The particles were non-reactive with the matrices within the temperature range of interest. The experiments were conducted such as to insure a planar solid/liquid interface during solidification. Particle location before and after processing was evaluated by X-ray transmission microscopy for the Al/ZrO2 samples. All samples were characterized by optical metallography after processing. A clear methodology for the experiment evaluation was developed to unambiguously interpret the occurrence of the pushing/engulfment transition. It was found that the critical velocity for engulfment ranges from 1.9 to 2.4 micron/s for Al/ZrO2 and from 1.9 to 2.9 microns/s for Zn/ZrO2.

Juretzko, Frank R.↗
NASA NTRSDate not supplied

Ignition of Metals in Heated Supersonic Particle Impact with Inert Particulate

The conventional understanding of particle impact ignition characteristic elements relies on the following principles: 1) flammable particulate (except in the case of titanium and aluminum target materials); 2) gas velocity greater than 100 ft/s; 3) Impact point ranging from 45° to perpendicular to the path of the particle [1]; 4) flammable target material. To test assumptions about particulate flammability being necessary for particle impact ignition of less reactive target materials, such as Inconel 718, testing was performed with inert particulate. Supersonic particle impact testing was conducted with heated gas and 1500-µm sapphire particulate on various target materials: 304 stainless steel, wrought and selective laser melted Inconel 718, and Monel 400. Posttest characterization of impact craters was performed on each type of metallic target sample, including surface characterization performed by light optical microscopy and scanning electron microscopy with energy dispersive spectroscopy. Full consumption of the stainless steel and wrought Inconel 718 targets were noted to occur with sequential impacts. The results of testing will be discussed in detail, as well as recommendations for updating the understanding of the particle impact ignition mechanism.

Particle Impact↗
DOE OSTI2025

Motion Dynamics of Motile Microbes in Pore-Networks and its Implications for Reactive Transport Processes

This report outlines new methods to improve simulations of microbial transport and microbially mediated reactions in porous media. A range of experimental, modeling, and machine learning tools are introduced to make these simulations faster, more reliable, and useful for real-world applications. At the microscopic level, the study investigates how different types of bacteria move through confined spaces. A new artificial intelligence tool called DeepTrackStat, is introduced to track motions dynamics as observed in videos of particles migrating through pore networks. This tool is especially helpful for studying fast-moving microbes and requires less computing power than traditional tracking methods. At larger scales, the research looks at how microbes and chemicals interact in zones where surface water and groundwater meet. To connect the small- and large-scale findings, the study presents a neural network model called STAMNet. This tool helps scale up detailed small-scale microbial motion behaviors to predict large-scale environmental changes more efficiently. By combining lab experiments, computer models, and artificial intelligence, the research presented supports smarter environmental decision-making, especially in bioremediation of contaminated groundwater and protection of water quality.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Decoding Gas Evolution Pathways and Interfacial Chemistry in Layered Oxide Cathodes for Safer Sodium‐Ion Batteries

Sodium-ion batteries (SIBs) are attractive for the low cost and abundance of sodium. Yet, gas evolution—a critical challenge in SIBs—remains underexplored. Here, online electrochemical mass spectrometry is used to probe gas evolution in layered oxide cathodes with various compositions, cutoff voltages, dopants, and particle morphologies. Compared to LiNiO 2 (LNO), NaNiO 2 releases more gas, even at lower states of charge, due to the higher covalency of Ni─O bond caused by the more ionic Na─O bond through the inductive effect. Among Co, Mn, Al, and Mg, Mn and Mg doping suppress gas release most effectively by enhancing the metal-oxygen bond strength. NaNi 1/3 Fe 1/3 Mn 1/3 O 2 (NFM) cathodes synthesized via coprecipitation (CP-NFM) and solid-state routes exhibit distinct particle morphologies; CP-NFM exhibits more gas evolution, yet secondary particle morphology helps reduce it through differential cathode-electrolyte reactivity between inner and outer primary particles. Among Li, Ti, Mg, and Cu doping in NFM, Li has the largest effect, reducing gas levels comparable to LNO. Nuclear magnetic resonance and X-ray photoelectron spectroscopies reveal that electrolyte solvent decomposition mainly produces organic-rich cathode-electrolyte interphase (CEI) rather than soluble species. NaPF 6 salt further exacerbates cathode-electrolyte reactions, forming surface Na 2 O species. The findings provide actionable guidance for designing safer, durable SIBs.

25 ENERGY STORAGE↗