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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 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Engineered Barrier System Research Activities at SNL: FY25 Report

This report describes research and development (R&D) activities conducted at Sandia National Laboratories (SNL) during Fiscal Year 2025 (FY25) specifically related to the Engineered Barrier System (EBS) Properties & Processes Work Package in the Spent Fuel and High-Level Waste Disposition (SFHLWD) Campaign supported by the United States (U.S.) Department of Energy (DOE). SNL activities focus on understanding EBS component evolution and interactions within the EBS, as well as interactions between the host media and the EBS. The team represented in this report consists of individuals from SNL, Argonne National Laboratory (Advanced Photon Source), and Vanderbilt University. The activities represented in this report include development of anion sorbent materials for buffer formulations, properties of pure bentonite and bentonite mixtures, and characterization of cement interfaces relevant to the EBS. The SNL EBS activities also leverage interactions with EBS teams from other national laboratories, and international collaborations to ensure that the DOE program is active and abreast of the latest advances in nuclear waste disposal.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS2013

Characterizing the Phyllosilicates and Amorphous Phases Found by MSL Using Laboratory XRD and EGA Measurements of Natural and Synthetic Materials

The Curiosity Rover landed on the Peace Vallis alluvial fan in Gale crater on August 5, 2012. A primary mission science objective is to search for past habitable environments, and, in particular, to assess the role of past water. Identifying the minerals and mineraloids that result from aqueous alteration at Gale crater is essential for understanding past aqueous processes at the MSL landing site and hence for interpreting the site's potential habitability. X-ray diffraction (XRD) data from the CheMin instrument and evolved gas analyses (EGA) from the SAM instrument have helped the MSL science team identify phases that resulted from aqueous processes: phyllosilicates and amorphous phases were measure in two drill samples (John Klein and Cumberland) obtained from the Sheepbed Member, Yellowknife Bay Fm., which is believed to represent a fluvial-lacustrine environment. A third set of analyses was obtained from scoop samples from the Rocknest sand shadow. Chemical data from the APXS instrument have helped constrain the chemical compositions of these secondary phases and suggest that the phyllosilicate component is Mg-enriched and the amorphous component is Fe-enriched, relatively Si-poor, and S- and H-bearing. To refine the phyllosilicate and amorphous components in the samples measured by MSL, we measured XRD and EGA data for a variety of relevant natural terrestrial phyllosilicates and synthetic mineraloids in laboratory testbeds of the CheMin and SAM instruments. Specifically, Mg-saturated smectites and vermiculites were measured with XRD at low relative humidity to understand the behavior of the 001 reflections under Mars-like conditions. Our laboratory XRD measurements suggest that interlayer cation composition affects the hydration state of swelling clays at low RH and, thus, the 001 peak positions. XRD patterns of synthetic amorphous materials, including allophane, ferrihydrite, and hisingerite were used in full-pattern fitting (FULLPAT) models to help determine the types and abundances of amorphous phases in the martian rocks and sand shadow. These models suggest that the rocks and sand shadow are composed of approx 30% amorphous phases. Sulfate-adsorbed allophane and ferrihydrite were measured by EGA to further understand the speciation of the sulfur present in the amorphous component. These data indicate that sulfate adsorbed onto the surfaces of amorphous phases could explain a portion of the SO2 evolution in the Rocknest SAM data. The additional constraints placed on the mineralogy and chemistry of the aqueous alteration phases through our laboratory measurements can help us better understand the nature of the fluids that affected the different samples and devise a history of aqueous alteration for the Sheepbed Member of the Yellowknife Bay Fm. at Gale crater.

Rampe, Elizabeth B.↗
NASA NTRS1985

The spatial evolution of energetic electrons and plasma waves during the steady state beam plasma discharge

Experiments, involving the injection of energetic (keV) electron beams into the ionosphere-upper atmosphere system from rocket-borne electron guns, have provided evidence for the occurrence of strong beam-plasma interactions (BPI) both near to and remote from the injection point. However, the flight experiments have not provided clear and unambiguous evidence for the basic physical processes which produce the variety of confusing signatures. A laboratory experimental program was initiated to clarify some of a number of ambiguities regarding the obtained results. The present investigation is concerned with some experimental studies of the evolution of both the beam energy spectrum and the local wave amplitude-frequency spectrum at increasing axial distances from the electron gun for a variety of experimental conditions. The results of the studies show that the high frequency beam-plasma interaction represents the most important process.

Llobet, X.↗
NASA NTRS1990

Evolution paths for advanced automation

As Space Station Freedom (SSF) evolves, increased automation and autonomy will be required to meet Space Station Freedom Program (SSFP) objectives. As a precursor to the use of advanced automation within the SSFP, especially if it is to be used on SSF (e.g., to automate the operation of the flight systems), the underlying technologies will need to be elevated to a high level of readiness to ensure safe and effective operations. Ground facilities supporting the development of these flight systems -- from research and development laboratories through formal hardware and software development environments -- will be responsible for achieving these levels of technology readiness. These facilities will need to evolve support the general evolution of the SSFP. This evolution will include support for increasing the use of advanced automation. The SSF Advanced Development Program has funded a study to define evolution paths for advanced automaton within the SSFP's ground-based facilities which will enable, promote, and accelerate the appropriate use of advanced automation on-board SSF. The current capability of the test beds and facilities, such as the Software Support Environment, with regard to advanced automation, has been assessed and their desired evolutionary capabilities have been defined. Plans and guidelines for achieving this necessary capability have been constructed. The approach taken has combined indepth interviews of test beds personnel at all SSF Work Package centers with awareness of relevant state-of-the-art technology and technology insertion methodologies. Key recommendations from the study include advocating a NASA-wide task force for advanced automation, and the creation of software prototype transition environments to facilitate the incorporation of advanced automation in the SSFP.

Healey, Kathleen J.↗
NASA NTRS1981

Evolution of the atmosphere of Venus

The photochemistry of the stratosphere of Venus was modeled using an updated and expanded chemical scheme, and the results of recent laboratory studies. The model satisfactorily accounts for the observations of CO, O2, (1) and SO2 in the stratosphere. Oxygen, derived from CO2 photolysis, is primarily consumed by CO2 recombination and oxidation of SO2 to H2SO4. Photolysis of HCl in the upper stratosphere provides a major source of odd hydrogen radicals essential for the catalytic oxidation of CO. Oxidation of SO2 by O occurs in the lower stratosphere, with the O-O bond broken by S + O2 and SO + HO2. The sensitivity of stratospheric chemistry to ambient H2 abundance was studied and the model prefers the high value (1 10 ppm) recently inferred from the Pioneer Venus ionospheric measurements. The importance of the photochemical production of S2O, (SO)2, S2, H2S2O2 and H2S2O3 is speculated. A number of previously unsuspected similarities between the chemistry of the stratospheres of Venus and the Earth, presented and discussed.

Yung, Y. L.↗
NASA NTRS1989

The nitrogen cycle on Mars

Nirtogen is an essential element for the evolution of life, because it is found in a variety of biologically important molecules. Therefore, N is an important element to study from a exobiological perspective. In particular, fixed nitrogen is the biologically useful form of nitrogen. Fixed nitrogen is generally defines as NH3, NH4(+), NO(x), or N that is chemically bound to either inorganic or organic molecules, and releasable by hydrolysis to NH3 or NH4(+). On Earth, the vast majority of nitrogen exists as N2 in the atmosphere, and not in the fixes form. On early Mars the same situations probably existed. The partial pressure of N2 on early Mars was thought to be 18 mb, significantly less than that of Earth. Dinitrogen can be fixed abiotically by several mechanisms. These mechanisms include thernal shock from meteoritic infall and lightning, as well as the interaction of light and sand containing TiO2 which produces NH3 that would be rapidly destroyed by photolysis and reaction with OH radicals. These mechanisms could have been operative on primitive Mars.The chemical processes effecting these compounds and possible ways of fixing or burying N in the Martian environment are described. Data gathered in this laboratory suggest that the low abundance of nitrogen along (compared to primitive Earth) may not significantly deter the origin and early evolution of a nitrogen utilizing organisms. However, the conditions on current Mars with respect to nitrogen are quite different, and organisms may not be able to utilize all of the available nitrogen.

Mancinelli, Rocco L.↗
DOE OSTI2025

Total absorption spectroscopy for the 𝛽 + decay strength distribution of 60 Ga

𝛽-decay properties play an important role in most astrophysical processes. In the absence of experimental data, astrophysical models rely on global theoretical calculations to provide the relevant properties. It is therefore important to provide strong experimental constraints when possible. In the case of 𝛽-decay, the most sensitive probe is the 𝛽-decay strength distribution. We report here on the first measurement of the latter quantity for the 𝛽 + decay of 60 Ga using the total absorption spectroscopy technique. The experimental results are compared to theoretical calculations often used in astrophysical models, namely the shell model and the quasiparticle random phase approximation (QRPA), as well as an extension of QRPA that includes higher-order nucleonic calculations. Both models are in reasonable agreement with the experimental results.

59 ≤ A ≤ 89↗
DOE OSTI2025

4D Observations of the initiation of abnormal grain growth in commercially pure Ni

Abnormal grain growth (AGG), where a small fraction of grains grow faster than others, is critical to predict because it can significantly impact material properties. However, the mechanism behind AGG remains unclear. In this study, laboratory-based x-ray diffraction contrast tomography (LabDCT) is employed to non-destructively track the 3D microstructural evolution of high-purity nickel during the onset of AGG at 800 °C. The initial microstructure state is used to test hypothesized microstructure predictors of the initiation of AGG. The change in grain size was not related to the initial grain size or normalized integral mean curvature. Additionally, the grain boundary energy distributions of abnormal grains were indistinguishable from those of control groups exhibiting normal grain growth. However, the grains that later became abnormal exhibit large areas of asymmetric tilt boundaries that were previously found to be fast. This 3D microstructure dataset is useful to investigate new hypotheses for the initiation of AGG.

36 MATERIALS SCIENCE↗
DOE OSTI2024

A theoretical/computational framework to measure SiO2 and MgO viscosity at high pressure

The convection of the mantle of Earth and super-Earths is important for many terrestrial phenomena, from plate tectonics to outgassing. Rheological properties, such as viscosity, regulate the transport of thermal energy and mass. However, the viscosity of mantle-relevant materials, such as MgO, at relevant pressures (>120 GPa) are not well constrained. The objective of this work was to develop a computational platform to simulate novel experiments aiming to measure the viscosity of MgO at high pressures. Experiments performed by our collaborators at Johns Hopkins University and Lawrence Livermore National Laboratory use the OMEGA EP laser facility to shock a corrugated MgO interface to 170 GPa, with resulting velocity evolution governed by the viscous Richtmyer-Meshkov instability. We used an in-house hydrocode to simulate this process and thus provide a bound on viscosity by comparing our simulations results to these experiments, as well as to examine the physical processes at play. We simulated the experiments with different values of MgO viscosity (from inviscid to 10,000 Pa∙s) while taking into account the unsteady laser pulse, the material's equation of state, and the rate-dependent constitutive relation for MgO, and the materials' equations of state. Our results suggest that MgO at these conditions has a viscosity within an order of magnitude of 5000 Pa∙s.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
NASA NTRS1973

Numerical simulation of small-scale thermal convection in the atmosphere

A Boussinesq system is integrated numerically in three dimensions and time in a study of nonhydrostatic convection in the atmosphere. Simulation of cloud convection is achieved by the inclusion of parametrized effects of latent heat and small-scale turbulence. The results are compared with the cell structure observed in Rayleigh-Benard laboratory conversion experiments in air. At a Rayleigh number of 4000, the numerical model adequately simulates the experimentally observed evolution, including some prominent transients of a flow from a randomly perturbed initial conductive state into the final state of steady large-amplitude two-dimensional rolls. At Rayleigh number 9000, the model reproduces the experimentally observed unsteady equilibrium of vertically coherent oscillatory waves superimposed on rolls.

Somerville, R. C. J.↗
NASA NTRS2015

Organics in Space: Results from Space Exposure Platforms and Nanosatellites

A series of successful laboratory astrophysics experiments performed on International Space Station(ISS) external platforms such as EXPOSE have provided insights into the evolution of organic and biological materials in space and planetary environments. The study of the reactions, destruction, and longevity of organics in the space environment is of fundamental interest. To provide an accurate outer space environment for extended durations, exposure experiments in low Earth orbit have been conducted in the last decades in order to examine the consequences of actual space conditions including combinations of solar and cosmic radiation, space vacuum, and microgravity. The OOREOS (OrganismORganic Exposure to Orbital Stresses) nanosatellite studied in situ during the 6-month primary and 1-year extended mission the photochemical processing of selected PAHs in low Earth orbit (650 km altitude); results were autonomously telemetered to Earth. We report on the methods and flight preparation of samples for space exposure platforms and results on the stability of organic thin-films. The UV-vis degradation process of thin-films was recorded over time, which revealed intriguing and counter-intuitive photolytic kinetics that will be re-investigated on the ISS in a space environment.

Space weathering↗
NASA NTRS1992

Evolution of the Space Station Freedom module pattern

A reanalysis of the evolution configuration module pattern for Space Station Freedom is presented. The module pattern is to consist of one habitation module, one airlock, one cupola, two Space Shuttle Orbiter pressurized docking adapters, one assured crew return vehicle, and one pressurized logistics module. Three laboratory modules are also included. A phased plan has been developed on the basis of utilization analysis being performed and derived through actual and projected user mission requirements for the growth of pressurized elements. The evolution requirement impacts to the module pattern are outlined. Application of the growth philosophy and the physical limitations resulted in a number of core element ground rules for module pattern growth. Nodes and modules are to be grown symmetrically in order to optimize poor flight control characteristics and maximize the capability for crew dual egress between elements. Core module pattern elements are not to be grown along Y-Y axis from nodes 1 or 2 due to physical clearance problems with the thermal control system radiators operational envelope.

Gould, Marston↗
NASA NTRS1978

Screening materials for smoke evolution

The density of smoke produced by burning or smoldering materials is a factor that affects the ability of occupants to escape from a burning structure and the effectiveness of firefighters. Accordingly, considerable effort is being spent on developing materials that minimize the amount of smoke without impairing their performance characteristics. In the present paper, laboratory tests on such materials are described and evaluated. It is seen that the National Bureau of Standards smoke test and the Ohio State University release-rate test are the most promising for screening materials for smoke evolution. It is shown that, for plastics, smoke obscuration is a more realistic concern than smoke toxicity.

Hilado, C. J.↗
NASA NTRSDate not supplied

The Aguas Zarcas Breccia - Similarities to Surface Features of C-Complex Asteroids Ryugu and Bennu

Knowledge of the materials originally present in the proto-solar nebula is one of the most significant constraints for models concerning the formation of our solar system. The physicochemical properties of these original materials can be determined through two distinct and complementary approaches: astronomical observations of nascent stellar systems and the dense clouds from which they originated; and laboratory studies of available astromaterials such as meteorites, interplanetary dust particles, comets, as well as returned mission samples (e.g., from Hayabusa -1 -2;OSIRIS -Rex). Laboratory study of these extraterrestrial materials provides valuable information about the first solids portion of the early solar system and their evolution. Here, we present petrographic and mineralogical characteristics of the polymic beccias Aguas Zarcas based on the research results of [1].On April 23, 2019, at 21:07 local time, a meteorite fall occurred in Aguas Zarcas, San Carlos County, Alajuela province, Costa Rica. The rapid recovery of this brecciated carbonaceous chondrite after its fall provides an opportunity to study a freshly fallen, relatively uncontaminated, and highly brecciated meteorite to compare with samples returned by theHayabusa2 and OSIRIS-REx spacecraft from C-group asteroids. The study includes several pre-rain fragments [1].The X-ray Computed Tomography (XCT) results show many different lithologies. We describe the petrography and mineralogy of five different lithologies of the Aguas Zarcas meteorite. We also present data on bulk oxygen isotopes. We describe all fragments in detail and attempt to classify each lithology in order to understand the origin and formation history of the Aguas Zarcas parent body. Our results show that some lithologies of Aguas Zarcas are similar to those in CM chondrites, but others are unique. The different lithologies [1] also represent different degrees of hydration and heating, which are good analogues for the types of materials returned by the Bennu and Ryugu asteroids. Spectroscopic observations of the Ryugu and Bennu asteroids compared to laboratory measurements of meteorites suggest that the asteroids have some similarities to heated CM, heated CI, or CI chondrites[2-5]. Both asteroids are thought to be composed of materials altered by aqueous alteration (e.g., [5]) and formed by reaccretion after destruction by impacts and brecciation (e.g., [6-7]). Considering the different lithologies in Aguas Zarcas [2] and other CM chondrites [8-9], these types of carbonaceous chondrites can be considered good analogues for samples from the Ryugu and Bennu asteroids. The presence of unique and rare lithologies in the Aguas Zarcas, different from the typical CM chondrite lithologies, suggests complex mixing of different materials in a highly dynamic environment.

Imene Kerraouch↗
NASA NTRS1989

The evolution of ecological tolerance in prokaryotes

The ecological ranges of Archaeobacteria and Eubacteria are constrained by a requirement for liquid water and the physico-chemical stability limits of biomolecules, but within this broad envelope, prokaryotes have evolved adaptations that permit them to tolerate a remarkable spectrum of habitats. Laboratory experiments indicate that prokaryotes can adapt rapidly to novel environmental conditions, yet geological studies suggest early diversification and long-term stasis within the prokaryotic kingdoms. These apparently contradictory perspectives can be reconciled by understanding that, in general, rates and patterns of prokaryotic evolution reflect the developmental history of the Earth's surface environments. Our understanding of modern microbial ecology provides a lens through which our accumulating knowledge of physiology, molecular phylogeny and the Earth's history can be integrated and focussed on the phenomenon of prokaryotic evolution.

NASA Discipline Number 52-30↗
DOE OSTI2026

Mathematical modelling of the concave front in the adjacent high explosive detonation problem

This study presents an analysis of the transition-zone in adjacent high explosive (HE) detonation problems which uses a $D, 𝜅, \dot{D}$ relationship, where $D$ is the detonation front-normal velocity, 𝜅 is the detonation front curvature and $\dot{D}$ is the time derivative of detonation front-normal velocity. Our approach extends the traditional $(D, 𝜅)$ model to accurately predict the behaviour of both diverging and converging detonation shock fronts. Our findings affirm that a hyperbolic type of front evolution equation, enhanced with wave acceleration, provides a robust framework for modelling complex shock front dynamics in HE materials. This approach not only captures the natural effects of straightness and boundary slope jumps in the transition-zone but also bridges the gap between mathematical predictions and experimental observations, offering insights into the behaviour of both diverging and converging detonation propagations in a homogeneous HE.

acceleration↗
DOE OSTI2025

An investigation of the physical and chemical changes of Pd nanoparticles on carbon supports in response to the release of hydrogen from aqueous formate solutions

Palladium nanoparticles on carbon supports (Pd/C) are effective for catalyzing hydrogen release from aqueous formate solutions but typically suffer from a gradual decrease of activity. This study finds two primary factors influencing activity: (i) the number of available surface Pd sites, and (ii) metal-support interactions which depend on the nature of the C support. We propose that the Pd/C catalyst is structure insensitive and undergoes Ostwald ripening to yield an active ‘conditioned’ catalyst with dispersion plateauing between ca. 15–20 %. Contrary to earlier studies, in-situ XANES experiments show that PdO is not an active catalyst for formate dehydrogenation. Calcination of Pd/C before dehydrogenation increases the catalytic activity which suggests a beneficial, albeit temporary, modification of the metal support interaction. N-containing supports minimize nanoparticle growth and also increase activity through a metal-support interaction. In conclusion, these findings advance our understanding of catalyst evolution and stability in formate dehydrogenation systems.

Formate dehydrogenation↗