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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 811 records · Page 45
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Microbial Community Composition in Deep‐Subsurface Reservoir Fluids Reveals Natural Interwell Connectivity

Abstract The identification of natural fractures and the wells they connect is crucial for the development of geological reservoirs because it may have an important impact on reservoir model construction and hydraulic fracture propagation. In this study we investigated the use of a novel data source, the microbial community composition in the reservoir formation fluids, for identification of interwell connectivity caused by natural fractures. We verified this concept at a newly developed mesoscale enhanced geothermal system (EGS) field testbed located 4,850 ft (1,478 m) beneath ground surface at the Sanford Underground Research Facility in Lead, SD. Fluids produced at or near the EGS testbed were sampled and subjected to high‐throughput 16S rRNA gene amplicon sequencing to analyze the microbial community profile therein. Despite the typically substantial heterogeneity across the community profiles of samples spatially distributed (10 m to 1.9 km apart) throughout the site, samples from two wells at the EGS testbed showed highly similar microbial community composition, suggesting the two wells intersected the same natural fracture. This evidence of natural connectivity between the two wells at the EGS testbed was later corroborated by core log analysis and sewer camera surveys into the boreholes. Besides the field case described in this study, microbial community composition as a reservoir diagnostic tool would be applicable in a much broader context such as unconventional hydrocarbon exploitation, groundwater reservoir characterization, and environmental remediation, adding valuable “hard” data capable of pinpointing the origins of fluids unambiguously.

Zhang, Yuran↗
NASA NTRS1995

A catalog of far-ultraviolet point sources detected with the fast FAUST Telescope on ATLAS-1

We list the photometric measurements of point sources made by the Far Ultraviolet Space Telescope (FAUST) when it flew on the ATLAS-1 space shuttle mission. The list contains 4698 Galactic and extragalactic objects detected in 22 wide-field images of the sky. At the locations surveyed, this catalog reaches a limiting magnitude approximately a factor of 10 fainter than the previous UV all-sky survey, TDl. The catalog limit is approximately 1 x 10(exp -14) ergs A sq cm/s, although it is not complete to this level. We list for each object the position, FUV flux, the error in flux, and where possible an identification from catalogs of nearby stars and galaxies. These catalogs include the Michigan HD (MHD) and HD, SAO, the HIPPARCOS Input Catalog, the Position and Proper Motion Catalog, the TD1 Catalog, the McCook and Sion Catalog of white dwarfs, and the RC3 Catalog of Galaxies. We identify 2239 FAUST sources with objects in the stellar catalogs and 172 with galaxies in the RC3 catalog. We estimate the number of sources with incorrect identifications to be less than 2%.

Bowyer, Stuart↗
NASA NTRS1976

Discovery of a nonsolar extreme-ultraviolet source

Results are reported for observations of EUV emission from an extrasolar object which were made with a grazing-incidence telescope during the Apollo-Soyuz mission. The total energy flux in the spectral band between 170 and 620 A is estimated to be approximately 4 by 10 to the -9th power erg/sq cm per sec. It is shown that the data support the identification of the EUV object with the ultrasoft X-ray source in Coma Berenices. The source of both emissions is suggested to be the hot white dwarf HZ 43, located at right ascension 13 hr 43 min and declination +29 deg 22 min (1950). The temperature of HZ 43 is estimated as 110,000 K, giving it the highest temperature of any known white dwarf.

Lampton, M.↗
NASA NTRS1972

Identification of the X-ray pulsar in Hercules: A new optical pulsar

A series of photographic, photoelectric, and spectroscopic observations beginning June 1, 1972 has led to the optical identification of Her X-1 (2U 1705 + 34), a pulsed X-ray source in an eclipsing binary system, with the thirteenth magnitude blue variable star HZ Herculis. The detection of optical pulses at the frequency of the X-ray pulsar on three nights makes the identification conclusive and establishes HZ Her as the second known optical pulsar. The strength of the optical pulses may be correlated with the orbital phase but is not obviously related to the high or low intensity states of the X-ray source.

Davidsen, A.↗
NASA NTRS2015

Investigation of the Makeup, Source, and Removal Strategies for Total Organic Carbon in the Oxygen Generation System Recirculation Loop

Since 2007, the Oxygen Generation System (OGS) on board the International Space Station (ISS) has been producing oxygen for crew respiration via water electrolysis. As water is consumed in the OGS recirculating water loop, make-up water is furnished by the ISS potable water bus. A rise in Total Organic Carbon (TOC) was observed beginning in February, 2011, which continues through the present date. Increasing TOC is of concern because the organic constituents responsible for the TOC were unknown and had not been identified; hence their impacts on the operation of the electrolytic cell stack components and on microorganism growth rates and types are unknown. Identification of the compounds responsible for the TOC increase, their sources, and estimates of their loadings in the OGA as well as possible mitigation strategies are presented.

Bowman, Elizabeth M.↗
DOE OSTI2015

Organic liquid scintillation detectors for on-the-fly neutron/gamma alarming and radionuclide identification in a pedestrian radiation portal monitor

Here, we present new experimental results from a radiation portal monitor based on the use of organic liquid scintillators. The system was tested as part of a 3 He-free radiation portal monitor testing campaign at the European Commission’s Joint Research Centre in Ispra, Italy, in February 2014. The radiation portal monitor was subjected to a wide range of test conditions described in ANSI N42.35, including a variety of gamma-ray sources and a 20,000 n/s 252 Cf source. A false alarm test tested whether radiation portal monitors ever alarmed in the presence of only natural background. The University of Michigan Detection for Nuclear Nonproliferation Group’s system triggered zero false alarms in 2739 trials. It consistently alarmed on a variety of gamma-ray sources travelling at 1.2 m/s at a 70 cm source to detector distance. The neutron source was detected at speeds up to 3 m/s and in configurations with up to 8 cm of high density polyethylene shielding. The success of on-the-fly radionuclide identification varied with the gamma-ray source measured as well as with which of two radionuclide identification methods was used. Both methods used a least squares comparison between the measured pulse height distributions to library spectra to pick the best match. The methods varied in how the pulse height distributions were modified prior to the least squares comparison. Correct identification rates were as high as 100% for highly enriched uranium, but as low as 50% for 241 Am. Lastly, both radionuclide identification algorithms produced mixed results, but the concept of using liquid scintillation detectors for gamma-ray and neutron alarming in radiation portal monitor was validated.

3He replacement technology↗
DOE OSTI2017

The IceCube realtime alert system

Although high-energy astrophysical neutrinos were discovered in 2013, their origin is still unknown. Aiming for the identification of an electromagnetic counterpart of a rapidly fading source, we have implemented a realtime analysis framework for the IceCube neutrino observatory. Several analyses selecting neutrinos of astrophysical origin are now operating in realtime at the detector site in Antarctica and are producing alerts for the community to enable rapid follow-up observations. The goal of these observations is to locate the astrophysical objects responsible for these neutrino signals. This paper highlights the infrastructure in place both at the South Pole site and at IceCube facilities in the north that have enabled this fast follow-up program to be implemented. Additionally, this paper presents the first realtime analyses to be activated within this framework, highlights their sensitivities to astrophysical neutrinos and background event rates, and presents an outlook for future discoveries.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

Stereoscopic high-speed microscopy to understand transient internal flow processes in high-pressure nozzles

The flow and cavitation behavior inside fuel injectors is known to affect spray development, mixing and combustion characteristics. We discuss that while diesel fuel injectors with converging and hydro-eroded holes are generally known to limit cavitation and feature higher discharge coefficients during the steady period of injection, less is known about the flow during transient periods corresponding to needle opening and closing. Multiple injection strategies involve short injections, multiplying these aspects and giving them a growing importance as part of the fuel delivery process. In this study, single-hole transparent nozzles were manufactured with the same hole inlet radius and diameter as the Engine Combustion Network Spray D nozzle, mounted to a modified version of a common-rail Spray A injector body and needle. Needle opening and closing periods were visualized with stereoscopic high-speed microscopy at injection pressures relevant to modern diesel engines. Time-resolved sac pressure was extracted via elastic deformation analysis of the transparent nozzles. Sources of cavitation were observed and tracked, enabling the identification of a gas exchange process after the end of injection with ingestion of chamber gas into the sac and orifice. We observed that the gas exchange contributed widely to disrupting the start of injection and outlet flow during the subsequent injection event.

42 ENGINEERING↗
DOE OSTI2021

AutoCCS: automated collision cross-section calculation software for ion mobility spectrometry–mass spectrometry

Abstract Motivation Ion mobility spectrometry (IMS) separations are increasingly used in conjunction with mass spectrometry (MS) for separation and characterization of ionized molecular species. Information obtained from IMS measurements includes the ion’s collision cross section (CCS), which reflects its size and structure and constitutes a descriptor for distinguishing similar species in mixtures that cannot be separated using conventional approaches. Incorporating CCS into MS-based workflows can improve the specificity and confidence of molecular identification. At present, there is no automated, open-source pipeline for determining CCS of analyte ions in both targeted and untargeted fashion, and intensive user-assisted processing with vendor software and manual evaluation is often required. Results We present AutoCCS, an open-source software to rapidly determine CCS values from IMS-MS measurements. We conducted various IMS experiments in different formats to demonstrate the flexibility of AutoCCS for automated CCS calculation: (i) stepped-field methods for drift tube-based IMS (DTIMS), (ii) single-field methods for DTIMS (supporting two calibration methods: a standard and a new enhanced method) and (iii) linear calibration for Bruker timsTOF and non-linear calibration methods for traveling wave based-IMS in Waters Synapt and Structures for Lossless Ion Manipulations. We demonstrated that AutoCCS offers an accurate and reproducible determination of CCS for both standard and unknown analyte ions in various IMS-MS platforms, IMS-field methods, ionization modes and collision gases, without requiring manual processing. Availability and implementation https://github.com/PNNL-Comp-Mass-Spec/AutoCCS. Supplementary information Supplementary data are available at Bioinformatics online. Demo datasets are publicly available at MassIVE (Dataset ID: MSV000085979).

47 OTHER INSTRUMENTATION↗
DOE OSTI2015

GADRAS Isotope ID User's Manual for Analysis of Gamma-Ray Measurements and API for Linux and Android

Isotope identification algorithms that are contained in the Gamma Detector Response and Analysis Software (GADRAS) can be used for real-time stationary measurement and search applications on platforms operating under Linux or Android operating systems. Since the background radiation can vary considerably due to variations in naturally-occurring radioactive materials (NORM), spectral algorithms can be substantially more sensitive to threat materials than search algorithms based strictly on count rate. Specific isotopes or interest can be designated for the search algorithm, which permits suppression of alarms for non-threatening sources, such as such as medical radionuclides. The same isotope identification algorithms that are used for search applications can also be used to process static measurements. The isotope identification algorithms follow the same protocols as those used by the Windows version of GADRAS, so files that are created under the Windows interface can be copied directly to processors on fielded sensors. The analysis algorithms contain provisions for gain adjustment and energy linearization, which enables direct processing of spectra as they are recorded by multichannel analyzers. Gain compensation is performed by utilizing photo-peaks in background spectra. Incorporation of this energy calibration tasks into the analysis algorithm also eliminates one of the more difficult challenges associated with development of radiation detection equipment.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2022

Low Pathogenicity H7N3 Avian Influenza Viruses Have Higher Within-Host Genetic Diversity Than a Closely Related High Pathogenicity H7N3 Virus in Infected Turkeys and Chickens

Within-host viral diversity offers a view into the early stages of viral evolution occurring after a virus infects a host. In recent years, advances in deep sequencing have allowed for routine identification of low-frequency variants, which are important sources of viral genetic diversity and can potentially emerge as a major virus population under certain conditions. We examined within-host viral diversity in turkeys and chickens experimentally infected with closely related H7N3 avian influenza viruses (AIVs), specifically one high pathogenicity AIV (HPAIV) and two low pathogenicity AIV (LPAIVs) with different neuraminidase protein stalk lengths. Consistent with the high mutation rates of AIVs, an abundance of intra-host single nucleotide variants (iSNVs) at low frequencies of 2–10% was observed in all samples collected. Furthermore, a small number of common iSNVs were observed between turkeys and chickens, and between directly inoculated and contact-exposed birds. Notably, the LPAIVs have significantly higher iSNV diversities and frequencies of nonsynonymous changes than the HPAIV in both turkeys and chickens. These findings highlight the dynamics of AIV populations within hosts and the potential impact of genetic changes, including mutations in the hemagglutinin gene that confers the high pathogenicity pathotype, on AIV virus populations and evolution.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Infrared Galaxies Detected by the Atacama Cosmology Telescope

We report on 167 infrared (IR) galaxies selected by AKARI and IRAS and detected in the Atacama Cosmology Telescope (ACT) Data Release 5 (DR5) sky maps at the 98, 150, and 220 GHz frequency bands. Of these detections, 134 (80%) of the millimeter counterparts are first-time identifications with ACT. We expand the previous ACT extragalactic source catalogs, by including new 98 GHz detections and measurements from ACT DR5. We also report flux density measurements at the 98, 150, and 220 GHz frequency bands. We compute α 98-150 , α 98-220 , and α 150-220 millimeter-wave spectral indices and far-IR to millimeter-wave spectral indices between 90 μm and 98, 150, and 220 GHz. We specify the galaxy type, based on α 150-220 . We combine publicly available multiwavelength data—including ultraviolet, optical, near-IR, mid-IR, far-IR, and the millimeter measurements obtained in this work—and perform spectral energy distribution (SED) fitting with CIGALE. With the radio emission decomposition advantage of CIGALE V2022.0, we identify the origins of the millimeter emissions for 69 galaxies in our sample. Our analysis also shows that millimeter data alone indicates the need for a radio synchrotron component in the SEDs that are produced by active galactic nuclei (AGNs) and/or star formation. We present SEDs and measured physical properties of these galaxies, such as the dust luminosity, AGN luminosity, the total IR luminosity, and the ratio of the IR and radio luminosity. We quantify the relationships between the total IR luminosity and the millimeter-band luminosities, which can be used in the absence of SED analysis.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1972

Amino acid precursors in lunar samples.

The use of hot water to extract lunar samples, followed by the hydrolysis of the aqueous extract, appears to be the method of choice for identification and quantitation of amino acid precursors in extraterrestrial sources. The net inferences from the analyses to date are (1) that amino acid precursors are verifiably present in lunar dust, and (2) that they are quite certainly not the consequence of contamination by terrestrial organisms, including man. It is suggested that prebiotic evolutionary pathways such as have been traversed on the earth were terminated on the moon for lack of sufficient water. Although some or all of the amino acid precursors may be indigenous, the low level observed suggests that they may also result from onfall of organic compounds from interstellar matter, comets, tails, solar wind, or meteorites.

Fox, S. W.↗
NASA NTRS1974

X-ray observations of the supernova remnant IC 443

Presented observation data from OSO-7 are shown to confirm the identification of IC 443 as an X-ray source, with a spectrum which is consistent with either thermal bremsstrahlung or a power law. These data lead to an age of 3400 years for IC 443, much younger than previous estimates.

Winkler, P. F., Jr.↗
NASA NTRS1975

Lunar cartographic dossier, volume 1

The dossier is designed to provide an up to date summary of the extent and quality of cartographic information as well as describing materials available to support lunar scientific investigation and study. It covers the specific photographic, selenodetic and cartographic data considered to be of continuing significance to users of lunar cartographic information. Historical background data is included. Descriptive and evaluative information is presented concerning lunar maps, photomaps and photo mosaics. Discussion comprises identification of series or individual sheet characteristics, control basis, source materials and compilation methodology used. The global, regional and local selenodetic control are described which were produced for lunar feature location in support of lunar mapping or positional study. Further discussion covers the fundamental basis for each control system, number of points produced, techniques employed and evaluated accuracy. Although lunar photography is an informational source rather than a cartographic product, a photography section was included to facilitate correlation to the mapping and control works described. Description of lunar photographic systems, photography and photo support data are presented from a cartographic-photogrammetric viewpoint with commentary on cartographic applications.

Schimerman, L. A.↗
NASA NTRS1979

Remote Sensing and Problems of the Hydrosphere

A discussion of freshwater and marine systems is presented including areas of the classification of lakes, identification and quantification of major functional groups of phytoplankton, sources and sinks of biochemical factors, and temporal and regional variability of surface features. Atmospheric processes linked to hydrospheric process through the transfer of matter via aerosols and gases are discussed. Particle fluxes to the aquatic environment and global geochemical problems are examined.

Goldberg, E. D.↗
NASA NTRS1982

Report of the Subpanel on Error Characterization and Error Budgets

The state of knowledge of both user positioning requirements and error models of current and proposed satellite systems is reviewed. In particular the error analysis models for LANDSAT D are described. Recommendations are given concerning the geometric error model for the thematic mapper; interactive user involvement in system error budgeting and modeling and verification on real data sets; and the identification of a strawman mission for modeling key error sources.

Source record↗
NASA NTRS1983

Voyager orbit determination at Jupiter

This paper summarizes the Voyager 1 and Voyager 2 orbit determination activity extending from encounter minus 60 days to the Jupiter encounter, and includes quantitative results and conclusions derived from mission experiences. The major topics covered include an identification and quantification of the major orbit determination error sources and a review of salient orbit determination results from encounter, with emphasis on the Jupiter approach phase orbit determination. Special attention is paid to the use of combined spacecraft-based optical observations and earth-based radiometric observations to achieve accurate orbit determination during the Jupiter encounter approach phase.

Campbell, J. K.↗