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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 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Powder Characterization Inter-Comparison

We performed qualitative and quantitative image analysis on SEM images for 5 uranium samples. Qualitative assessment was completed using the lexicon of Tamasi et al. 2017 on a subset of images from each sample to provide an overall morphological profile of each material. Quantitative analysis of the particles was done using the Morphological Analysis for Materials Attribution, or MAMA, software. We performed particle analysis primarily on samples labeled U Mo, U Si, and UO 2 . Samples labeled ADU and DU Ox were not prioritized for quantitative analysis due to staffing and time it took to segment these images. Two lab analysts worked on this effort, one focusing on the qualitative assessment and the other focusing on the quantitative assessment.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2023

E-Area Low-Level Waste Facility Multitiered Groundwater and Intruder Radionuclide Screening

Solid Waste Management (SWM) operates the E-Area Low-Level Waste Facility (ELLWF) where low level on-site and off-site solid waste streams are buried. The facility has been in operation since late 1994 and is currently projected to remain in operation until 2065. This facility can accommodate a broad range of waste forms resulting from the six different types of disposal unit (DU) options (i.e., varying degrees of engineered barriers → trenches to concrete vaults). This facility is currently operating under a Performance Assessment (PA) issued back in 2008 (WSRC 2008), along with several subsequent supporting Special Analyses (SAs). The Savannah River National Laboratory (SRNL) developed the prior PAs and SAs and was tasked to update the facility’s upcoming PA, most likely to be issued during FY2023. For operating the E-Area facility, a Consolidated Waste Tracking System (CWTS) is actively employed by waste generators where every radionuclide entering the facility, to be buried in one of its many DUs1, must be either directly or indirectly tracked. Since there are many radionuclides in existence (>3,000), the International Commission on Radiological Protection (ICRP), specially ICRP Publication 107, has provided guidance on the subset of radionuclides requiring further assessment in landfills such as the ELLWF. The ICRP 107 publication provides critical radiological information on 1,252 radionuclides consisting of 97 elements. This database, along with the current dose coefficients that have been developed for these radionuclides in DOE-STD-1196-2011 (DOE 2011), is the critical starting point for developing a consistent inventory limit system.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2025

Templates for Risk Informed Assurance with Curvature Embeddings (TRACE)

We investigate recovery of geometric structure from networks embedded in manifolds with spatially varying curvature, extending the constant-curvature framework of Lubold et al. (2023). Our work supports cascade risk assessment in critical infrastructure through the Templates for Risk-informed Assurance with Curvature Embeddings (TRACE) framework. Simulations on a bi-modal Gaussian surface show that constant-curvature methods yield weighted averages shaped by clique patterns, while hierarchical clustering identifies distinct regimes. Localized estimation, however, reveals boundary contamination in transitional regions. To address heterogeneity, we develop distance metrics for graphs with edge and node features, proving their metric validity, and validate them via deterministic graph generation from canonical tilings. We further propose a diffusion-based anomaly detection approach that treats networks as glued manifolds, using curvature discontinuities to detect structural anomalies. Employing the carré-du-champ operator and scalar curvature, we achieve robust anomaly discrimination, demonstrated on the Singapore Water Treatment (SWaT) dataset with joint network-traffic and sensor features. Integration with TRACE reveals how curvature shapes cascade dynamics: positive curvature impedes, while negative curvature accelerates propagation. This geometric perspective provides interpretable risk metrics and visualization tools for critical infrastructure managers. While full validation remains ongoing, our contributions establish a rigorous foundation for geometric analysis of network resilience and cascade vulnerability.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2022

R-Value Measurements Performed on Actinide Targets Irradiated using the GODIVA IV Critical Assembly in FY22

The separation and characterization of two irradiated uranium targets, a depleted uranium (DU) and a highly enriched uranium (HEU) target as well as a plutonium (Pu) target, was conducted in April of 2022. The three targets were assembled at Los Alamos National Laboratory (LANL) and irradiated using the GODIVA critical assembly at the National Criticality Experiments Research Center (NCERC). Splits of the dissolved targets were received by Pacific Northwest National Laboratory (PNNL) after which the PNNL and LANL teams chemically separated the solutions using independent separation schemes and analyzed the separated fractions for short lived actinides and fission products. Chemical separations were traced with stable or radioactive tracers to allow for the determination of chemical yields, analyzing using either inductively coupled plasma optical emission spectroscopy (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS) or gamma emission analysis (GEA) depending on the nature of the tracer. The Pu target solution was traced with stable elements at LANL to follow elemental fractionation during a Pu removal step. Many analytical techniques were used by PNNL including kinetic phosphorescence analysis (KPA), ICP-OES, ICP-MS, GEA, and thermal ionization mass spectrometry (TIMS) depending on the analyte’s need.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2026

ZPRD Database: ZPPR-15 Monte Carlo Results

The ZPPR-15 experiments [1] were mockups of a 330 MWe Integral Fast Reactor (IFR). The ZPPR-15 assembly consisted of a clean, two zone, approximately circular core surrounded by a thin depleted uranium (DU) blanket with sodium (Na) cooling and a thick stainless steel reflector. The ZPPR-15 program was conducted in four phases: A, B, C, and D. Each phase was marked by a particular composition of the reference assembly, with the last three being representative of the three stages of the IFR fuel cycle. This report documents all MCNP [2] runs of the ZPPR-15 loadings that were included in the ZPRD database on GitLab. In the present work, eigenvalues and associated standard deviations were computed for each ZPPR-15 loading with the use of the three data libraries (ENDF/B-VII.0 [3], ENDF/B-VII.1 [4] and ENDF/B-VIII.0 [5]). Relevant results from the obtained outputs are also discussed in this report with two main objectives: a) provide and evaluate updated calculated values with respect to previous reports, notably Refs. [6] and [7] that were based on the use of the ENDF/B-VII.0 library. b) address any change in the observed reactivity effects relevant to the analysis of the experimental data when a different data library is used (previously reported results were mostly based on the use of ENDF/B-VII.0 data only).

Aliberti, Gerardo↗
DOE OSTI2021

SPRUCE Diurnal and Seasonal Patterns of Water Potential in S1 Bog and SPRUCE Experimental Plot Vegetation beginning in 2010

This data set reports on water potential from excised terminal shoots or leaves (Mainthemum only) of vegetation at the SPRUCE site located in the S1 bog. Pretreatment measurements were collected from outside plots within the S1 bog. Post treatments were collected from inside SPRUCE plots. Water potential was measured on the overstory canopy species, consisting of the evergreen Picea mariana (Mill.) B.S.P. (black spruce) and deciduous Larix laricina (Du Roi) K. Koch (tamarack) trees, and ericaceous shrubs < 1 m tall, consisting of the evergreen Rhododendron groenlandicum (Oeder) Kron & Judd (Labrador tea) and Chamaedaphne calyculata (L.) Moench. (leatherleaf). Some measurement campaigns also included the evergreen Kalmia polifolia, Wangenh. (bog laurel), the deciduous Vaccinium angustifolium (Aiton) (blueberry), and the herbaceous Maianthemum trifolium (L.) Sloboda (three-leaf false Solomon’s seal). This dataset contains one data file in comma-separated (*.csv) format. This is the second release of water potential data from the site with additional data from 2018 and 2019. These data cover 2010-06-22 to 2019-07-16. Further results will be added to this data set and released to the public periodically as quality assurance and publication of results are accomplished. There are 10 experimental plots in SPRUCE: five temperature treatments (+0, +2.25, +4.5, +6.75, +9°C) at ambient CO2, and the same five temperature treatments at elevated CO2 (+500 ppm). These data span the pre- and post-treatment periods when enclosed plots were exposed to warming and elevated carbon dioxide (CO2) within the SPRUCE experiment. The pretreatment samples were collected from south end of the S1 bog prior to SPRUCE boardwalk construction, then throughout the bog once the boardwalks were completed.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Dataset for "Bioaerosols are the dominant source of warm-temperature immersion-mode INPs and drive uncertainties in INP predictability

Ice nucleating particles (INPs) are a rare subset of atmospheric aerosol that can initiate primary ice formation and thus trigger cloud glaciation. The re is a significant gap between our ability to measure INPs and to predict their concentrations and variability in large-scale weather and climate models. Accurate simulation of I NPs requires simulation of their major particle sources, as well as representative parameterizations of IN efficiency. Thus, there is a need for measurements of INP concentrations , delineated by particle type, to validate and improve model prediction of INP concentrations. Here we present a novel method for speciating INP concentrations into the relative c ontributions from dust, sea spray aerosol (SSA), and bioaerosol using single particle measurements. In a field campaign at Bodega Bay (coastal California), we find that bioaerosol s were the primary source of INPs between -12 and -20 ?C, while dust was a relatively minor source and SSA did not contribute significantly. We show that recent INP parameterizati ons for dust and SSA accurately predict ambient INP concentrations for these particle types. Finally, we use the speciated INP concentrations to evaluate the simulation of INPs at Bodega Bay, using a Lagrangian approach to connect the locally-observed aerosol with regionally-widespread emissions parameterizations. We find that we can skillfully simulate du st and SSA INPs, but not bioaerosol INPs. This points to a need for additional research to identify the major factors controlling the emissions and INP efficiency of bioaerosol IN Ps in order to develop improved parameterizations and enable their improved representation in models.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

APOGEE Data and Spectral Analysis from SDSS Data Release 16: Seven Years of Observations Including First Results from APOGEE-South

The spectral analysis and data products in Data Release 16 (DR16; 2019 December) from the high-resolution near-infrared Apache Point Observatory Galactic Evolution Experiment (APOGEE)-2/Sloan Digital Sky Survey (SDSS)-IV survey are described. Compared to the previous APOGEE data release (DR14; 2017 July), APOGEE DR16 includes about 200,000 new stellar spectra, of which 100,000 are from a new southern APOGEE instrument mounted on the 2.5 m du Pont telescope at Las Campanas Observatory in Chile. DR16 includes all data taken up to 2018 August, including data released in previous data releases. All of the data have been re-reduced and re-analyzed using the latest pipelines, resulting in a total of 473,307 spectra of 437,445 stars. Changes to the analysis methods for this release include, but are not limited to, the use of MARCS model atmospheres for calculation of the entire main grid of synthetic spectra used in the analysis, a new method for filling “holes” in the grids due to unconverged model atmospheres, and a new scheme for continuum normalization. Abundances of the neutron-capture element Ce are included for the first time. A new scheme for estimating uncertainties of the derived quantities using stars with multiple observations has been applied, and calibrated values of surface gravities for dwarf stars are now supplied. Compared to DR14, the radial velocities derived for this release more closely match those in the Gaia DR2 database, and a clear improvement in the spectral analysis of the coolest giants can be seen. The reduced spectra as well as the result of the analysis can be downloaded using links provided on the SDSS DR16 web page.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1980

Comments on numerical solution of boundary value problems of the Laplace equation and calculation of eigenvalues by the grid method

The mathematics involved in numerically solving for the plane boundary value of the Laplace equation by the grid method is developed. The approximate solution of a boundary value problem for the domain of the Laplace equation by the grid method consists of finding u at the grid corner which satisfies the equation at the internal corners (u=Du) and certain boundary value conditions at the boundary corners.

Lyusternik, L. A.↗
NASA NTRS1980

High-resolution Lyman-alpha filtergrams of the sun

The results of an experiment, conducted jointly by the Lockheed Palo Alto Research Laboratory and the Laboratoire de Physique Stellaire et Planetaire du CNRS, which investigated the transition-region plasma and the geometry of coronal active regions, in relation to models of the high-temperature layers, are presented. A Black Brant rocket was used to obtain 1-arc sec resolution L-alpha pictures of the sun, which revealed small scale features not seen previously at this wavelength, that delineate the geometry of the magnetic field in the chromosphere and in the corona. It is concluded that these observations might provide a new way of observing the upper chromosphere and corona, and that they provide direct evidence of the inhomogeneous character of the chromosphere and of the dominant role of the magnetic field

Bonnet, R. M.↗
NASA NTRS1985

Develop and demonstrate manufacturing processes for fabricating graphite filament reinforced polymide (Gr/PI) composite structural elements

A study was conducted to assess the merits of using graphite/polyimide, NR-150B2 resin, for structural applications on advanced space launch vehicles. The program was divided into two phases: (1) Fabrication Process Development; and (2) Demonstration Components. The first phase of the program involved the selection of a graphite fiber, quality assurance of the NR-150B2 polyimide resin, and the quality assurance of the graphite/polyimide prepreg. In the second phase of the program, a limited number of components were fabricated before the NR-150B2 resin system was removed from the market by the supplier, Du Pont. The advancement of the NR-150B2 polyimide resin binder was found to vary significantly based on previous time and temperature history during the prepregging operation. Strength retention at 316C (600F) was found to be 50% that of room temperature strength. However, the composite would retain its initial strength after 200 hours exposure at 316C (600F). Basic chemistry studies are required for determining NR-150B2 resin binder quality assurance parameters. Graphite fibers are available that can withstand high temperature cure and postcure cycles.

Chase, V. A.↗
NASA NTRS1984

Reduction of astrographic catalogues

An automatic program for the reduction of overlapping Carte du Ciel plates is described. The projection and transformation equations are given and the RAA subprogram flow is outlined. The program was applied to two different sets of data, namely to nine overlapping plates of the Cape Zone of the CdC, and to fifteen plates taken with the CIDA-refractor of the open cluster Tr10.

Stock, J.↗
NASA NTRS1985

Effect of low-velocity or ballistic impact damage on the strength of thin composite and aluminum shear panels

Impact tests were conducted on shear panels fabricated from 6061-T6 aluminum and from woven fabric prepreg of Du Pont Kevlara fiber/epoxy resin and graphite fiber/epoxy resin. The shear panels consisted of three different composite laminates and one aluminum material configuration. Three panel aspect ratios were evaluated for each material configuration. Composite panels were impacted with a 1.27-cm (0.05-in) diameter aluminum sphere at low velocities of 46 m/sec (150 ft/sec) and 67 m/sec (220 ft/sec). Ballistic impact conditions consisted of a tumbled 0.50-caliber projectile impacting loaded composite and aluminum shear panels. The results of these tests indicate that ballistic threshold load (the lowest load which will result in immediate failure upon penetration by the projectile) varied between 0.44 and 0.61 of the average failure load of undamaged panels. The residual strengths of the panels after ballistic impact varied between 0.55 and 0.75 of the average failure strength of the undamaged panels. The low velocity impacts at 67 m/sec (220 ft/sec) caused a 15 to 20 percent reduction in strength, whereas the impacts at 46 m/sec (150 ft/sec) resulted in negligible strength loss. Good agreement was obtained between the experimental failure strengths and the predicted strength with the point stress failure criterion.

Farley, G. L.↗
NASA NTRS1985

Polyimide matrix resins for up to 700 deg F service

TRW is in the process of data accumulation that strongly indicates that incorporation of the perfluorsisopropylidene linkage in molecular structures other than those employed in DU Pont's NR-150B polyimides likewise yield polymers demonstrating extremely high thermo-oxidative stability. Polyimide synthetic and characterization studies conducted to date on new polymers incorporating the perfluoroisopropylidene linkage are presented and discussed.

Jones, R. J.↗
NASA NTRS1984

Users guide: Steady-state aerodynamic-loads program for shuttle TPS tiles

A user's guide for the computer program that calculates the steady-state aerodynamic loads on the Shuttle thermal-protection tiles is presented. The main element in the program is the MITAS-II, Martin Marietta Interactive Thermal Analysis System. The MITAS-II is used to calculate the mass flow in a nine-tile model designed to simulate conditions duing a Shuttle flight. The procedures used to execute the program using the MITAS-II software are described. A list of the necessry software and data files along with a brief description of their functions is given. The format of the data file containing the surface pressure data is specified. The interpolation techniques used to calculate the pressure profile over the tile matrix are briefly described. In addition, the output from a sample run is explained. The actual output and the procedure file used to execute the program at NASA Langley Research Center on a CDC CYBER-175 are provided in the appendices.

Kerr, P. A.↗
NASA NTRS1985

Perturbations of the Richardson number field by gravity waves

An analytic solution is presented for a stratified fluid of arbitrary constant Richardson number. By computer aided analysis the perturbation fields, including that of the Richardson number can be calculated. The results of the linear analytic model were compared with nonlinear simulations, leading to the following conclusions: (1) the perturbations in the Richardson number field, when small, are produced primarily by the perturbations of the shear; (2) perturbations of in the Richardson number field, even when small, are not symmetric, the increase being significantly larger than the decrease (the linear analytic solution and the nonlinear simulations both confirm this result); (3) as the perturbations grow, this asymmetry increases, but more so in the nonlinear simulations than in the linear analysis; (4) for large perturbations of the shear flow, the static stability, as represented by N2, is the dominating mechanism, becoming zero or negative, and producing convective overturning; and (5) the convectional measure of linearity in lee wave theory, NH/U, is no longer the critical parameter (it is suggested that (H/u sub 0) (du sub 0/dz) takes on this role in a shearing flow).

Wurtele, M. G.↗
NASA NTRS1985

Morphological and physical characteristics of the Virgo Cluster - First results from the Las Campanas photographic survey

Preliminary results are presented of a photographic survey of the Virgo cluster to the faintest convenient limit of the Las Campanas du Pont 2.5 m reflector, performed in order to study the complexity of both the surface and velocity distributions within the central 6 degree radius region. The survey is described and the resulting Catalog is discussed, and the frequency of galaxy types found and listed in the Catalog is described. The physical properties of the dwarfs are summarized, and luminosity functions are given separately for each morphological type. The progressive change of (MBT) faintward along the morphological sequence from Sc I through Sm and Im types is shown, leading to a calibration of the de Vaucouleurs Lambda luminosity index and a determination of its intrinsic dispersion. The preliminary results on the distribution of galaxies of all types in the two principal subclustering regions found are summarized, and the velocity distributions over the face of the 6 degree core are discussed for the various galaxy types.

Sandage, A.↗
NASA NTRS1986

NOAA 26.5 Ah LEO characterization test

The General Electric (GE) 26.5 Ah NOAA-G flight nickel-cadmium cells were obtained from RCA-Astro Electronics to undergo performance characterization testing at the Goddard Space Flight Center (GSFC). This lot of cells was manufactured with passivated positive plate, to control nickel structure attack duing active material impregnation, and less electrolyte than normal (less than 3cc/Ah). The cells were tested in a parametric low Earth orbit (LEO) cycling regime that was previously used to test and characterize standard 50 Ah cells. Life cycle testing at the Naval Weapons Support Center (NWSC), in Crane, followed. The results of the test showed nominal performance in comparison with previous test data on the standard 50. Life cycle testing in the NOAA orbital regime is continuing at NWSC.

Morrow, G. W.↗