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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 649 records · Page 36
All sourcesNASA NTRSDOE OSTI
NASA NTRS2005

Nature of the South Pole on Mars Determined by Topographic Forcing of Atmosphere Dynamics

Introduction: The observed Springtime (Ls approx. 200) surface albedo in the Martian southern polar region is shown in Figure 1. In general, the hemisphere west of Hellas is marked by relatively high values of surface albedo. In contrast, the hemisphere east of Hellas contains extensive regions of very low surface albedo. One of the brightest features within the western hemisphere is the South Pole Residual Cap (SPRC). The dark region, which dominates the eastern hemisphere, is the "Cryptic" region[1]. The nature of the SPRC has been the source of considerable debate since its identification as CO2 ice by the Viking spacecraft. Two fundamental questions still exist regarding the SPRC s formation, location and stability. First, why is the SPRC offset from the geographic pole? There are no local topographic features or surface properties that can account for the offset in the SPRC. Second, does the SPRC represent a large or a small reservoir of CO2? If the former, then it could possibly buffer the surface pressure. If the latter, then the SPRC may not survive every year.

Colaprete, A.↗
NASA NTRS2012

Using the XMM-Newton Optical Monitor to Study Cluster Galaxy Evolution

We explore the application of XMM Newton Optical Monitor (XMM-OM) ultraviolet (UV) data to study galaxy evolution. Our sample is constructed as the intersection of all Abell clusters with z < 0.05 and having archival XMM-OM data in either the UVM2 or UVW1 filters, plus optical and UV photometry from the Sloan Digital Sky Survey and GALEX, respectively. The 11 resulting clusters include 726 galaxies with measured redshifts, 520 of which have redshifts placing them within their parent Abell clusters. We develop procedures for manipulating the XMM-OM images and measuring galaxy photometry from them, and we confirm our results via comparison with published catalogs. Color-magnitude diagrams (CMDs) constructed using the XMM-OM data along with SDSS optical data show promise for evolutionary studies, with good separation between red and blue sequences and real variation in the width of the red sequence that is likely indicative of differences in star formation history. This is particularly true for UVW1 data, as the relative abundance of data collected using this filter and its depth make it an attractive choice. Available tools that use stellar synthesis libraries to fit the UV and optical photometric data may also be used, thereby better describing star formation history within the past billion years and providing estimates of total stellar mass that include contributions from young stars. Finally, color-color diagrams that include XMM-OM UV data appear useful to the photometric identification of both extragalactic and stellar sources.

Miller, Neal A.↗
NASA NTRS2013

Tool for Automated Retrieval of Generic Event Tracks (TARGET)

Methods have been developed to identify and track tornado-producing mesoscale convective systems (MCSs) automatically over the continental United States, in order to facilitate systematic studies of these powerful and often destructive events. Several data sources were combined to ensure event identification accuracy. Records of watches and warnings issued by National Weather Service (NWS), and tornado locations and tracks from the Tornado History Project (THP) were used to locate MCSs in high-resolution precipitation observations and GOES infrared (11-micron) Rapid Scan Operation (RSO) imagery. Thresholds are then applied to the latter two data sets to define MCS events and track their developments. MCSs produce a broad range of severe convective weather events that are significantly affecting the living conditions of the populations exposed to them. Understanding how MCSs grow and develop could help scientists improve their weather prediction models, and also provide tools to decision-makers whose goals are to protect populations and their property. Associating storm cells across frames of remotely sensed images poses a difficult problem because storms evolve, split, and merge. Any storm-tracking method should include the following processes: storm identification, storm tracking, and quantification of storm intensity and activity. The spatiotemporal coordinates of the tracks will enable researchers to obtain other coincident observations to conduct more thorough studies of these events. In addition to their tracked locations, their areal extents, precipitation intensities, and accumulations all as functions of their evolutions in time were also obtained and recorded for these events. All parameters so derived can be catalogued into a moving object database (MODB) for custom queries. The purpose of this software is to provide a generalized, cross-platform, pluggable tool for identifying events within a set of scientific data based upon specified criteria with the possibility of storing identified events into a searchable database. The core of the application uses an implementation of the connected component labeling (CCL) algorithm to identify areas of interest, then uses a set of criteria to establish spatial and temporal relationships between identified components. The CCL algorithm is used for identifying objects within images for computer vision. This application applies it to scientific data sets using arbitrary criteria. The most novel concept was applying a generalized CCL implementation to scientific data sets for establishing events both spatially and temporally. The combination of several existing concepts (pluggable components, generalized CCL algorithm, etc.) into one application is also novel. In addition, how the system is designed, i.e., its extensibility with pluggable components, and its configurability with a simple configuration file, is innovative. This allows the system to be applied to new scenarios with ease.

Clune, Thomas↗
NASA NTRS2012

The Geometric Factor of Electrostatic Plasma Analyzers: A Case Study from the Fast Plasma Investigation for the Magnetospheric Multiscale mission

We report our findings comparing the geometric factor (GF) as determined from simulations and laboratory measurements of the new Dual Electron Spectrometer (DES) being developed at NASA Goddard Space Flight Center as part of the Fast Plasma Investigation on NASA's Magnetospheric Multiscale mission. Particle simulations are increasingly playing an essential role in the design and calibration of electrostatic analyzers, facilitating the identification and mitigation of the many sources of systematic error present in laboratory calibration. While equations for laboratory measurement of the Geometric Factpr (GF) have been described in the literature, these are not directly applicable to simulation since the two are carried out under substantially different assumptions and conditions, making direct comparison very challenging. Starting from first principles, we derive generalized expressions for the determination of the GF in simulation and laboratory, and discuss how we have estimated errors in both cases. Finally, we apply these equations to the new DES instrument and show that the results agree within errors. Thus we show that the techniques presented here will produce consistent results between laboratory and simulation, and present the first description of the performance of the new DES instrument in the literature.

Magnetospheric Multiscale Mission↗
NASA NTRS2016

Mineralogy, Provenance, and Diagenesis of a Potassic Basaltic Sandstone on Mars: CheMin X-Ray Diffraction of the Windjana Sample (Kimberley Area, Gale Crater)

The Windjana drill sample, a sandstone of the Dillinger member (Kimberley formation, Gale Crater, Mars), was analyzed by CheMin X-ray diffraction (XRD) in the MSL Curiosity rover. From Rietveld refinements of its XRD pattern, Windjana contains the following: sanidine (21% weight, approximately Or(sub 95)); augite (20%); magnetite (12%); pigeonite; olivine; plagioclase; amorphous and smectitic material (approximately 25%); and percent levels of others including ilmenite, fluorapatite, and bassanite. From mass balance on the Alpha Proton X-ray Spectrometer (APXS) chemical analysis, the amorphous material is Fe rich with nearly no other cations-like ferrihydrite. The Windjana sample shows little alteration and was likely cemented by its magnetite and ferrihydrite. From ChemCam Laser-Induced Breakdown Spectrometer (LIBS) chemical analyses, Windjana is representative of the Dillinger and Mount Remarkable members of the Kimberley formation. LIBS data suggest that the Kimberley sediments include at least three chemical components. The most K-rich targets have 5.6% K2O, approximately 1.8 times that of Windjana, implying a sediment component with greater than 40% sanidine, e.g., a trachyte. A second component is rich in mafic minerals, with little feldspar (like a shergottite). A third component is richer in plagioclase and in Na2O, and is likely to be basaltic. The K-rich sediment component is consistent with APXS and ChemCam observations of K-rich rocks elsewhere in Gale Crater. The source of this sediment component was likely volcanic. The presence of sediment from many igneous sources, in concert with Curiosity's identifications of other igneous materials (e.g.,mugearite), implies that the northern rim of Gale Crater exposes a diverse igneous complex, at least as diverse as that found in similar-age terranes on Earth.

Treiman, Allan H.↗
DOE OSTI2022

Scaling Building Energy Audits through Machine Learning Methods on Novel Drone Image Data

Building energy audits are time-consuming and labor-intensive. This paper describes a new method using machine learning (ML) techniques on novel data sources (drone images) to improve the identification of building characteristics and retrofit opportunities, and thereby reduce the effort for audits. The new ML method includes: (1) Building footprint extraction using line extraction, polygonization, and polygon-merging, (2) Building envelope extraction using PIX4d modeling software to reconstruct a building 3D model, (3) Visualization tool for viewing images from the 3D model, (4) Window-to-wall ratio (WWR) using state-of-art deep neural network semantic segmentation, (5) Envelope thermal anomaly detection using an unsupervised machine learning clustering algorithm, and (6) Rooftop energy equipment detection based on an object detection algorithm. The testing of this method involved a comparison of additional ML-generated information overlaid on current ‘state-of-practice’ audit and remote assessment baselines using evaluation metrics: labor time and associated cost, marginal benefits of using ML-generated information in workflows for audits and remote assessments, integration potential with existing processes and tools, and replicability/scalability of the method. In two test buildings in California that had comprehensive drawings and meter data available, the ML method effectively generated a building footprint, envelope, rooftop equipment, WWR, and locations of envelope thermal anomalies. Projected target segments of the ML method are sites with minimal drawings and energy data, and underserved sectors such as multistoried housing, disadvantaged communities, and schools for which the ML method can enable identification of building asset characteristics and prioritization of envelope retrofits and decentralized energy equipment retrofits.

Singh, Reshma↗
DOE OSTI2022

Energy-resolved mass spectrometry as a tool for identification of lignin depolymerization products

Lignin is the largest source of bio-based aromatic compounds in nature, and its valorization is essential to the sustainability of lignocellulosic biorefining. Characterizing lignin-derived compounds remains challenging due to the heterogeneity of this biopolymer. Tandem mass spectrometry is a promising tool for lignin structural analytics, as fragmentation patterns of model compounds can be extrapolated to identify characteristic moieties in complex samples. This work extends previous resonance excitation type collision-induced dissociation (CID) methods that identified lignin oligomers containing β-Ο-4, β-5, and β-β bonds, to also identify characteristics of 5-5, β-1, and 4-Ο-5 dimers, enabled by quadrupole time-of-flight (QTOF) CID with energy-resolved mass spectrometry (ERMS). Overall, beam type ERMS offers in-depth structural information and could ultimately contribute to tools for high-throughput lignin dimer identification.

09 BIOMASS FUELS↗
NASA NTRS1984

The HEAO A-1 X-ray source catalog

The catalog of X-ray sources detected during the NRL Large Area Sky Survey (LASS) with the HEAO 1 satellite is presented. The catalog is derived from the first six months of data from HEAO 1 and includes sources detected during one full scan. Positions and intensities for a total of 842 different sources are included, with a limiting flux of 250 nJy at 5 keV. The catalog is more than 90 percent complete at a flux level equivalent to 1.5 microjoules at 5 keV for a Crab-like spectrum. Cross-references with published literature are provided and coincidental identifications are proposed for some of the sources which have been never studied before. A cross-sectional line drawing of the sensor module of HEAO I is also provided.

Wood, K. S.↗
NASA NTRS2009

NEOCAM: Near Earth Object Chemical Analysis Mission: Bridging the Gulf between Telescopic Observations and the Chemical and Mineralogical Compositions of Asteroids or Diogenes A: Diagnostic Observation of the Geology of Near Earth Spectrally-Classified Asteroids

Studies of meteorites have yielded a wealth of scientific information based on highly detailed chemical and isotopic studies possible only in sophisticated terrestrial laboratories. Telescopic studies have revealed an enormous (greater than 10(exp 5)) number of physical objects ranging in size from a few tens of meters to several hundred kilometers, orbiting not only in the traditional asteroid belt between Mars and Jupiter but also throughout the inner solar system. Many of the largest asteroids are classed into taxonomic groups based on their observed spectral properties and are designated as C, D. X, S or V types (as well as a wide range in sub-types). These objects are certainly the sources far the meteorites in our laboratories, but which asteroids are the sources for which meteorites? Spectral classes are nominally correlated to the chemical composition and physical characteristics of the asteroid itself based on studies of the spectral changes induced in meteorites due to exposure to a simulated space environment. While laboratory studies have produced some notable successes (e.g. the identification of the asteroid Vesta as the source of the H, E and D meteorite classes), it is unlikely that we have samples of each asteroidal spectral type in our meteorite collection. The correlation of spectral type and composition for many objects will therefore remain uncertain until we can return samples of specific asteroid types to Earth for analyses. The best candidates for sample return are asteroids that already come close to the Earth. Asteroids in orbit near 1 A.U. have been classified into three groups (Aten, Apollo & Amor) based on their orbital characteristics. These Near Earth Objects (NEOs) contain representatives of virtually all spectral types and sub-types of the asteroid population identified to date. Because of their close proximity to Earth, NEOs are prime targets for asteroid missions such as the NEAR-Shoemaker NASA Discovery Mission to Eros and the Japanese Hyabusa Mission to Itokawa. Also due to their close proximity to Earth, NEOs constitute the most likely set of celestial objects that will impact us in the relatively near future.

Nuth, Joseph A.↗
NASA NTRS1976

Optical identification of A0620-00

Identification of the optical counterpart to the transient X-ray source A0620-00 was made using image tube photography. Spectra taken subsequent to the identification showed no stellar absorption or emission features. Photometric data gave a V magnitude of 11.2 + or - .1. This is about 8 magnitudes brighter than the object appears on the Palomar Sky Survey.

Wolfson, R.↗
NASA NTRS1999

The Nature of the Unidentified EUV Sources: Accreting Isolated Neutron Stars?

The aims of this project were: (1) to investigate the nature of the EUVE (Extreme Ultraviolet Explorer Satellite) 'NOID' sources, objects detected in the EUV bandpass but with no previous identification at optical or other energies; (2) to study the possible association of NOID sources with nearby, isolated neutron stars among the 1e9 predicted to exist in the Galaxy. These dead radio pulsars have not been detected so far in large numbers, but accretion from the interstellar medium can make them bright at EUV wavelengths; and (3) to use the EUVE data to set constraints on neutron star evolution, accretion physics and population properties. The original objectives of our program remain relevant. Indeed, the level of research in this area has increased substantially since our proposal was submitted as a result of new data from the ROSAT (Roentgen Satellite).

Madau, Piero↗
DOE OSTI2026

Carbon source–driven metabolic and regulatory remodeling defines phenomic states in Lipomyces starkeyi

Lipomyces is a genus of oleaginous yeasts with potential for contributing to reliable biomanufacturing supply chains. However, progress in advanced strain designs and engineering efforts are still constrained by a lack of understanding of the underlying molecular drivers of Lipomyces phenotypes. To address this gap, we collected a suite of multi-omic data to dissect how carbon source availability reshapes the metabolic network, lipid allocation, and regulatory architecture of Lipomyces starkeyi. We observed that glucose promotes biosynthetic and proliferative processes supported by abundant energy and carbon intermediates, xylose enhances redox-balancing mechanisms centered on the pentose phosphate pathway, and glycerol activates respiratory metabolism, ß-oxidation, and the glyoxylate cycle. Lipid species distributions remained consistent in both nitrogen replete and depleted conditions across the carbon sources, indicating robust production mechanisms. Regulatory protein identification and network analysis revealed glycerol-driven respiratory growth favors regulatory programs integrating stress tolerance, redox balance, and lipid-associated metabolism, whereas xylose growth activates compensatory transcriptional responses aimed at maintaining mitochondrial function. Nitrogen limitation modulates the strength of these responses but does not fundamentally alter their direction, reinforcing carbon source as the dominant driver of regulatory architecture. Taken together, this data enhances the understanding of Lipomyces molecular rearrangements and provides a foundation for further development of predictive phenotypic tools in this genus.

Biotechnology↗
DOE OSTI2016

THE SCUBA-2 COSMOLOGY LEGACY SURVEY: MULTIWAVELENGTH COUNTERPARTS TO 10{sup 3} SUBMILLIMETER GALAXIES IN THE UKIDSS-UDS FIELD

We present multiwavelength identifications for the counterparts of 1088 submillimeter sources detected at 850 μm in the SCUBA-2 Cosmology Legacy Survey study of the UKIRT Infrared Deep Sky Survey-Ultra-Deep Survey (UDS) field. By utilizing an Atacama Large Millimeter Array (ALMA) pilot study on a subset of our bright SCUBA-2 sample as a training set, along with the deep optical–near-infrared (OIR) data available in this field, we develop a novel technique, Optical–IR Triple Color (OIRTC), using z − K, K − [3.6], [3.6] − [4.5] colors to select the candidate submillimeter galaxy (SMG) counterparts. By combining radio identification and the OIRTC technique, we find counterpart candidates for 80% of the Class = 1 ≥ 4σ SCUBA-2 sample, defined as those that are covered by both radio and OIR imaging and the base sample for our scientific analyses. Based on the ALMA training set, we expect the accuracy of these identifications to be 82% ± 20%, with a completeness of 69% ± 16%, essentially as accurate as the traditional p-value technique but with higher completeness. We find that the fraction of SCUBA-2 sources having candidate counterparts is lower for fainter 850 μm sources, and we argue that for follow-up observations sensitive to SMGs with S{sub 850} ≳ 1 mJy across the whole ALMA beam, the fraction with multiple counterparts is likely to be >40% for SCUBA-2 sources at S{sub 850} ≳ 4 mJy. We find that the photometric redshift distribution for the SMGs is well fit by a lognormal distribution, with a median redshift of z = 2.3 ± 0.1. After accounting for the sources without any radio and/or OIRTC counterpart, we estimate the median redshift to be z = 2.6 ± 0.1 for SMGs with S{sub 850} > 1 mJy. We also use this new large sample to study the clustering of SMGs and the far-infrared properties of the unidentified submillimeter sources by stacking their Herschel SPIRE far-infrared emission.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

Expectation-propagation for weak radionuclide identification at radiation portal monitors

We propose a sparsity-promoting Bayesian algorithm capable of identifying radionuclide signatures from weak sources in the presence of a high radiation background. The proposed method is relevant to radiation identification for security applications. In such scenarios, the background typically consists of terrestrial, cosmic, and cosmogenic radiation that may cause false positive responses. We evaluate the new Bayesian approach using gamma-ray data and are able to identify weapons-grade plutonium, masked by naturally-occurring radioactive material (NORM), in a measurement time of a few seconds. We demonstrate this identification capability using organic scintillators (stilbene crystals and EJ-309 liquid scintillators), which do not provide direct, high-resolution, source spectroscopic information. Compared to the EJ-309 detector, the stilbene-based detector exhibits a lower identification error, on average, owing to its better energy resolution. Organic scintillators are used within radiation portal monitors to detect gamma rays emitted from conveyances crossing ports of entry. The described method is therefore applicable to radiation portal monitors deployed in the field and could improve their threat discrimination capability by minimizing “nuisance” alarms produced either by NORM-bearing materials found in shipped cargoes, such as ceramics and fertilizers, or radionuclides in recently treated nuclear medicine patients.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
NASA NTRS1983

X-ray observations of M33 with the high resolution imager on the Einstein Observatory

Three observations, separated by 6 months, of the Local Group galaxy M33 using the high resolution imager (HRI) on the Einstein Observatory are reported. Eight X-ray sources with luminosites ranging from 8 x 10 to the 36th to 1.2 x 10 to the 39th ergs/s have been detected. For seven of these sources, finding charts with positions accurate to less than 5 arcsec are provided. The X-ray properties and possible identifications are discussed for the eight HRI-detected sources and for two other sources, previously described by Long et al. (1981), for which upper limits are provided. It is found that most of the sources are associated with Population I markers. One source may be coincident with an optical supernova remnant. The most luminous source (by a factor of at least 25) is that associated with the optical nucleus. Because the X-ray flux from the nucleus decreased by a factor of 1/2 between the first and second observations, it is most likely that a single, compact object is responsible for the X-ray emission. It is possible that this source may be an active galactic nucleus, a massive binary X-ray source, or a low-mass X-ray binary such as are found in globular clusters within the Galaxy.

Markert, T. H.↗
DOE OSTI2020

Impedance localization and identification

The beam coupling impedance represents one of the sources of potential beam instabilities in particle accelerators. The localization of large coupling impedance sources is therefore very important in order to focus the efforts for mitigation measures when these are needed. In this work we will focus on the common methods adopted to quantify the transverse impedance of a particle accelerator both from the global and the local point of views. This activity can be performed in both bunched and coasting beams following different strategies.

43 PARTICLE ACCELERATORS↗