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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 469 records · Page 26

Data from Stewart et al. 2026 "Organic Colloid Composition in Variable-Redox Porewaters within a Mountainous Floodplain"

Redox gradients, often driven by changes in sediment moisture levels in porous, heterogeneous groundwater systems, create dynamic conditions that may promote the production and transport of colloids within natural waters. While much research has focused on the inorganic composition of colloids, the organic composition remains less well understood. Organic matter (OM) in colloids may associate with minerals, complex metal ions, and serve as an electron donor for microbial respiration; therefore, its composition is of high interest. We examined the composition of porewater OM along a redox gradient in a riparian soil located along the Slate River in Crested Butte, Colorado, USA as a function of depth (90, 130, 200, and 350 cm below ground surface). All depths were oxic to suboxic, except 200 cm, where the products of iron and sulfate reduction were observed concomitant with an increase in dissolved and/or colloidal OM, pH, alkalinity, and conductivity. We investigated the composition of porewater using correlated scanning transmission X-ray microscopy and transmission electron microscopy. We observed a change in the OM chemistry from carboxylate-rich at the 200 cm depth (where it was also enmeshed with non-crystalline iron) to phenol- and substituted-aromatic-rich at other depths. Radiocarbon dating revealed carbon in porewater at 200 cm was younger than depths above and below. Soil porewater can flow down into the underlaying gravel bed during baseflow conditions, thus we speculate whether riparian porewater could transport iron- and carboxylate-rich organic colloids into surrounding surface waters through the gravel bed conduit. This data package includes geochemical data (.csv) as a function of depth from porewaters in OBJ1. Measurements included are pH, conductivity, TOC, Fe concentration, sulfate concentration, dissolved oxygen. Additionally radiocarbon dating age of carbon in samples is provided. Additionally, this dataset contains metadata files (.csv) describing the methods, file contents, and column headers.

alpine floodplain↗

Imaging APO-BMI with Micro X-ray Computed Tomography (CT)

APO-BMI is a high-strength, high-temperature, and low-density foam comprised of 1,2-bis(2-aminophenylthio) ethane (APO-Link, formerly Apocure-601) and 4,4’-bismaleimidodiphenylmethane (BMI) that is used structural applications within the aerospace and weapons manufacturing sectors. APO-link is the diamine reagent used to synthesize BMI, a thermosetting resin. This resin can remain in a molten, flowing state for an extended period of time before crosslinking, allowing addition of glass or carbon microballoons to form its final structure. A portion of the current project was to observe the thermal effects on the structural integrity of the foam associated with exposure to an ion beam. Features within the foam were imaged using micro X-ray computed tomography (CT). The resulting imaging provided evidence that microballoon structure remained mostly intact at the points of failure, indicating that the failure of the material was occurring in the binder material.

36 MATERIALS SCIENCE↗

National Fire Protection Association Spurs the Safe Adoption of EVs Through Education and Outreach

As electric vehicles (EV) and their charging infrastructure steadily increase in popularity across the U.S., growing pains still exist, impeding their true potential for growth. The barriers include a general lack of knowledge around EV systems, range anxiety, electrical workplace safety practices, code compliance and inspection for charging stations, maintenance garages and workers, insurance concerns, and the potential risks associated with damaged lithium-ion batteries (fires, re-ignition, water immersion, and stranded energy).NFPA partnered with SMEs, training development organizations, and Clean City Coalitions to create a series of common online trainings for each EV ecosystem sector, educating communities on the realities of EV proliferation, myths, facts, statistics, codes, and basic information for each sector to become versed in EV knowledge. We also constructed a workshop program for the many EV stakeholders who should be involved in setting up a strategic, cohesive outlook for the participating towns and cities.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

The absorption-line spectrum of the quasi-stellar object PHL 957

Six high-dispersion spectra of the quasar PHL 957 are analyzed which were obtained with an integrating television system at the Coude focus of the 200-inch Hale telescope. One hundred seventy-nine absorption lines are found, and seven absorption-line redshift systems are identified. The system at z equals 2.3099 is shown to be most prominent, with 26 lines including a very strong L-alpha line. A system close to the emission redshift is found to be double, and many lines in all the systems are identified as Lyman alpha-beta pairs. Column densities and velocity dispersions are obtained from curves of growth for the major systems and the Lyman pairs. The system at z equals 2.3099 is found to resemble interstellar material in ionization and abundance ratios and constitutes strong evidence for absorption originating in a galaxy along the line of sight to the quasar. The double system is found to have higher ion states and is probably associated with the quasar.

Wingert, D. W.↗

The composition of corotating energetic particle streams

The relative abundances of 1.5 to 23 MeV/nucleon ions in corotating nucleon streams were compared with ion abundances in particle events associated with solar flares and with solar and solar wind abundances. He/O and C/O ratios were found to be a factor of the order two to three times greater in corotating streams than in flare associated events. The distribution of H/He ratios in corotating streams was found to be much narrower and of lower average value than in flare associated events. H/He in corotating energetic particle streams compared favorably both in lack of variability and numerical value to H/He in high speed solar wind plasma streams. This comparison suggested that the source population for the corotating energetic particles was the solar wind.

Mcguire, R. E.↗

The composition of corotating energetic particle streams

The relative abundances of 1.5-23 MeV per nucleon ions in corotating nucleon streams are compared with ion abundances in particle events associated with solar flares and with solar and solar wind abundances. He/O and C/O ratios are found to be a factor of the order 2-3 greater in corotating streams than in flare-associated events. The distribution of H/He ratios in corotating streams is found to be much narrower and of lower average value than in flare-associated events. H/He in corotating energetic particle streams compares favorably in both lack of variability and numerical value with H/He in high-speed solar wind plasma streams. The lack of variability suggests that the source population for the corotating energetic particles is the solar wind, a suggestion consistent with acceleration of the corotating particles in interplanetary space.

Mcguire, R. E.↗

An extreme ultraviolet spectrometer experiment for the Shuttle Get Away Special Program

An extreme ultraviolet (EUV) spectrometer experiment operated successfully during the STS-7 mission in an experiment to measure the global and diurnal variation of the EUV airglow. The spectrometer is an F 3.5 Wadsworth mount with mechanical collimator, a 75 x 75 mm grating, and a bare microchannel plate detector providing a spectral resolution of 7 X FWHM. Read-out of the signal is through discrete channels or resistive anode techniques. The experiment includes a microcomputer, 20 Mbit tape recorder, and a 28V, 40 Ahr silver-zinc battery. It is the first GAS payload to use an opening door. The spectrometer's 0.1 x 4.2 deg field of view is pointed vertically out of the shuttle bay. During the STS-7 flight data were acquired continuously for a period of 5 hours and 37 minutes, providing spectra of the 570 A to 850 A wavelength region of the airglow. Five diurnal cycles of the 584 A emission of neutral helium and the 834 A emission of ionized atomic oxygen were recorded. The experiment also recorded ion events and pressure pulses associated with thruster firings. The experiment is to fly again on Mission 41-F.

Conway, R. R.↗

The evolutionary development of high specific impulse electric thruster technology

Electric propulsion flight and technology demonstrations conducted primarily by Europe, Japan, China, the U.S., and the USSR are reviewed. Evolutionary mission applications for high specific impulse electric thruster systems are discussed, and the status of arcjet, ion, and magnetoplasmadynamic thrusters and associated power processor technologies are summarized.

Sovey, James S.↗

Electron acceleration by low frequency electric field fluctuations - Electron conics

Electron conics can be generated by fluctuations at roughly one Hz in a parallel electric field accelerating auroral electrons at altitudes of several thousand kilometers. The results from simulations including such time-varying electric fields are in good agreement with observed electron distributions. The simulation parameters are consistent with the ion beams and broadband waves associated with electron conics. Calculations are used to predict for example oscillations in the low altitude electron fluxes. These results can be used to compare different possible mechanisms for the generation of electron conics.

Andre, Mats↗

Evaluating auroral processes within a magnotospheric model

A summary of the research performed is included. Topics covered include magnetospheric model; association between discrete auroras and ion precipitation from the tail current sheet; auroral arc scale sizes and structures; polar cap size variation; low-altitude auroral boundary; auroral wave-particle interactions; thermospheric interactions; and the neutral wind 'flywheel'.

Lyons, L. R.↗

Origin of flux ropes in Venus' ionosphere

The joule dissipation inside flux ropes in Venus' ionosphere is so great that they must be formed near, and maintained at, the place where they are observed. Thus ropes are not formed by a Kelvin-Helmholtz instability of the ionopause. The hypothesis that ropes may be formed by the dynamo action of internal gravity waves in Venus' thermosphere (Luhmann and Elphic, 1985; Cole, 1993) is strengthened by discussion of a magnetic evolution equation which includes neutral air motion. However, the dynamo process would work only at altitudes at which v(sub in) is greater than or equal to omega(sub i). At altitudes or parts of a rope where v(sub in) is much less than omega(sub i), the process does not work. A solar wind dynamo is therefore examined to account for the ropes. Thereby a major new heat source for ions of the Venus ionosphere associated with the ropes is uncovered.

Cole, Keith D.↗

Alpha particle heating at comet-solar wind interaction regions

The satellite observations at comet Halley have shown strong heating of solar wind alpha particles over an extended region dominated by high-intensity, low-frequency turbulence. These waves are excited by the water group pickup ions and can energize the solar wind plasma by different heating processes. The alpha particle heating by the Landau damping of kinetic Alfven waves and the transit time damping of low-frequency hydromagnetic waves in this region of high plasma beta are studied in this paper. The Alfven wave heating was shown to be the dominant mechanism for the observed proton heating, but it is found to be insufficient to account for the observed alpha particle heating. The transit time damping due to the interaction of the ions with the electric fields associated with the magnetic field compressions of magnetohydrodynamic waves is found to heat the alpha particles preferentially over the protons. Comparison of the calculated heating times for the transit time damping with the observations from comet Halley shows good agreement. These processes contribute to the thermalization of the solar wind by the conversion of its directed energy into the thermal energy in the transition region at comet-solar wind interaction.

Sharma, A. S.↗

Modelling of the outer heliosphere

The interaction of the outflowing solar wind with the local interstellar medium (LISM) is complicated by many factors--the solar wind itself is a highly dynamical medium, interstellar neutral atoms can interact with the heliospheric boundaries in a complex fashion and the solar wind can be decelerated via mass-loading associated with pick-up ions, for example. Anomalous and galactic cosmic rays besides being modulated by the solar wind, may react back on the heliospheric boundaries leading to possibly significant structural modifications. These and other factors suggest that the physics of the outer heliosphere is strongly influenced by the properties of the very LISM and is quite different from the physics of the inner heliosphere. In this talk, we will try to synthesize the many recent developments in modelling the outer heliosphere and boundaries, encompassing both local and global models. Special emphasis will be placed on identifying those aspects of the various models which have observational implications.

Zank, G. P.↗

Magnetospheric Multiscale Observations of an Expanding Oxygen Wave in Magnetic Reconnection

Heavier plasma species such as oxygen ions can have a large impact on the magnetic reconnection process. It has been hypothesized that the acceleration of demagnetized oxygen ions by the Hall electric field will lead to the formation of an oxygen wave that expands into the exhaust. By comparing data from NASA's Magnetospheric Multiscale mission to a fully kinetic particle-in-cell simulation, we can for the first time provide observational evidence of such an expanding oxygen wave. The wave is characterized by an oxygen jet consisting of cold ions directed toward the neutral sheet associated with a density cavity. This density cavity forms as the EO are subject to collective acceleration by the Hall electric field leaving behind a region of low-density oxygen ions. Our results are important for the understanding of the role and effect of oxygen ions in magnetic reconnection.

Hakon Midthun Kolsto↗

Data-driven method to estimate contamination from light ion beam transmutation at colliders

Collisions of relativistic light ions, such as oxygen, neon, and magnesium, have been proposed as a way to examine the system-size dependence of dynamics typically associated with the quark-gluon plasma produced in collisions of heavier ions such as xenon, gold, or lead. Recent efforts at both the Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) have produced large datasets of proton-oxygen, oxygen-oxygen, and neon-neon collisions, catalyzing intense interest in experimental backgrounds associated with light-ion collisions. In particular, electromagnetic dissociation of light ions while they are circulating in a collider can result in beam contamination that is difficult to simulate precisely. Here we propose a data-driven method for evaluating the potential impact of beam contaminants on physics analyses. The method exploits the time dependence and smaller size of contaminant ion species to define control regions that can be used to quantify potential contamination effects. A simple model is used to illustrate the method and to study its robustness. Furthermore, this method can inform studies of recent LHC and RHIC data and could also be useful for future light-ion programs at the LHC and beyond.

Beam loss↗

Bands of ions and angular V's - A conjugate manifestation of ionospheric ion acceleration

Data from the hot plasma instruments on Dynamics Explorer 1 and 2 spacecraft have been used to study the injection, drift, and subsequent precipitation of suprathermal positive ions in the auroral zone. The observation at both high and low altitudes of electron inverted 'V' events in the boundary plasma sheet (BPS) and of ion 'bands' (energy decreasing with decreasing latitude) in the adjacent central plasma sheet (CPS) leads to the following ion injection model: upward-moving energetic ion beams are injected onto BPS magnetic field lines by the electrostatic potential drops associated with electron inverted V's. As the ion beams move toward the equator and into the conjugate hemisphere they are convected to lower latitudes and into the CPS. The energy-latitude dependence of the ion bands, coupled with concurrent ion convection measurements, indicate that the ion distributions are primarily O(+), in agreement with their postulated ionospheric source.

Winningham, J. D.↗

Multi‐Species Energy‐Banded Ions in the Ionosphere During the 21 January 2005 Magnetic Storm: Low‐Altitude Edge of the Warm Plasma Cloak

During the 21–22 January 2005 magnetic storm, the FAST satellite observed warm (< few keV) ions in discrete energy bands on the dayside at ∼3,000 km altitude for more than 6.5 hr. We suggest that the ionospheric energy-banded ions represent the low-altitude edge of the warm plasma cloak observed simultaneously by magnetospheric satellites. This is a clear example of the multi-species ion energy bands (10 eV to several keV) observed during strong magnetic storms by the FAST satellite, stretching from the diffuse auroral region to the plasmapause with lifetimes up to 12 hr. The close association of these energy-banded ions with magnetic storms, their broad latitudinal extent, and the presence of multiple ion species in the same energy band, rather than at the same velocity, indicate that this is a distinct phenomenon from other types of energy-banded ions. During the 21–22 January 2005 magnetic storm, the dayside ion energy band structures, centered at 10 eV (H + ), 40 eV (H + and He + ), and 160 eV (H + , He + , and O + ), were consistent with a “time-of-flight and velocity filter” formation process acting on a near-cusp, impulsive outflow of a <200 eV multi-species ion-source population, poleward and in the same hemisphere as FAST. Understanding the sources and dynamics of warm energy-banded ions and their linkage to the warm plasma cloak is important because during superstorms these ions are transported to L values as low as L ∼ 1.2 in the dawn sector, significantly altering the energetics of the mid-latitude ionosphere.

58 GEOSCIENCES↗

Possible in situ detection of K(2+) in the Jovian magnetosphere

During the Voyager 1 and 2 encounters with Jupiter in 1979 the positive ion composition of the cold thermal plasma in the Jovian plasma sheet and cold Io torus could be obtained when the plasma Mach number in the spacecraft rest frame was sufficiently large. Clear indication of an ionic species with a mass-to-charge ratio between 16 (O(+) and/or S(2+)) and 23 Na(+) is present in two spectra were acquired during apparent crossings of the plasma sheet in the middle magnetosphere. One interpretation is that the most likely identification of the ion is K(2+), even though there is no evidence in the data for K(+). Such an ion presence would be consistent with reports of neutral potassium associated with the Jovian system and originating at Io as well as with the identification of an ion with a similar mass-to-charge ratio at higher energies in the Ulysses data. An alternative interpretation is that the ion is a singly ionized molecular species associated with water products sputtered from Europa, a scenario which may also be consistent with the Ulysses data. However, other species present in the data and the low temperature favor the Iogenic potassium hypothesis.

Mcnutt, Ralph L, Jr.↗