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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 1,027 records · Page 57
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Mu2e straw tube tracker gas flow quality control

Here, we present a tracker gas flow quality control method developed for the Mu2e straw tube tracker. Using time-dependent current measurements, we quantify the onset time of ionization gain induced by an 55 F source during gas exchange, which is correlated to the gas conductance in the straw. This allows for the identification of channels with inadequate flow. This approach is broadly applicable to other gaseous detectors that require high-channel-count screening.

Flow↗
DOE OSTI2019

Investigating the Effectiveness of P/S Amplitude Ratios for Local Distance Event Discrimination

The ability to discriminate between underground explosions and earthquakes is an important operation for global security and test-ban-treaty monitoring, and seismology plays a key role in this endeavor. The use of seismic P- to S-wave amplitude ratios has been demonstrated to be an effective discriminant at regional distances for a variety of emplacement conditions and test sites around the world. Increasing interest in detecting and discriminating smaller events, both for purposes of nuclear monitoring and seismic hazard estimation, requires the use of data with shorter event-to-station paths. At these local distances (≤ 200 km), the use of P/S ratios for event discrimination is poorly studied compared with regional distances (200-1500 km). The path averaging that allows for relatively simple corrections to P/S ratios to remove bias from along-path structural differences at regional distances may be insufficient to remove enough scatter from the ratios to allow for accurate event identification at local distances. We use data from a series of chemical explosions detonated as part of the Source Physics Experiment at the Nevada National Security Site in southern Nevada and surrounding seismicity to investigate the discrimination performance of P/S ratios at local distances. We find that discrimination at individual stations is highly variable, regardless of frequency. Network averaging of ratios improves discrimination performance above 6 Hz, as a result of the reduction of scatter among the earthquake ratios. Furthermore, azimuthal and distance–limited averaging suggests that explosion ratios are affected by a complicated source and path relationship that may lead to substantial variability in local P/S ratios at different locations.

58 GEOSCIENCES↗
DOE OSTI2025

SITCOMTN-163: Source Selection for Abell 360 in LSSTComCam Data Preview 1

We cover the source selection done for the Abell 360 LSSTComCam cluster study focusing on color and photo-z cuts. Identification of cluster members via the red sequence and photo-z offers a science focused validation of photometry with LSSTComCam. We are able to cross-match with DESI spectroscopic redshifts to offer an independent validation suite on photo-z estimates. We make various color and photo-z cuts to generate N(z)s and shear profiles. We find that both cuts are quite robust to various choices made and can produce a shear profile for Abell 360. Both methods should be applicable to generating a consistent mass estimate for the cluster.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1971

Tranquillity Base map.

A comparison of the qualities of photographs taken by astronauts Armstrong and Aldrin from Tranquillity Base and of photographs taken from the Lunar Module window, in terms of valuable information. The latter, found to be more reliable than the former, are used as the primary source in compiling the Tranquillity Base Surface and Experiment Locations Map. The former are rated as excellent for identification purposes and are used in locating supplemental details. However, the geometry obtained on most of these latter frames is believed to be less reliable because of large changes in vertical angles.

Arant, W. H.↗
NASA NTRS1976

Directory of aerospace safety specialized information sources, volume 2

A handbook of organizations and experts in specific and well-defined areas of safety technology is presented. It is designed for the safety specialist as an aid for locating both information sources and individual points of contact (experts) in engineering related fields. The file covers sources of data in aerospace design, tests, and operations, as well as information on hazard and failure cause identification, accident analysis, and materials characteristics. Other related areas include the handling and transportation of hazardous chemicals, radioactive isotopes, and liquified natural gases.

Rubinstein, R. I.↗
NASA NTRS1978

Advanced designs for fluid flow visualization

Research was carried out on existing and new designs for minimally intrusive measurement of flow fields in the Geophysical Fluid Flow Cell and the proposed Atmospheric General Circulation Experiment. The following topics are discussed: (1) identification and removal of foreign particles, (2) search for higher dielectric photochromic solutions, (3) selection of uv light source, (4) analysis of refractive techniques and (5) examination of fresnel lens applicability.

Source record↗
NASA NTRS1981

Discovery of a protostar in the Large Magellanic Cloud

A near infrared search of the H II region/molecular cloud complex N159 in the Large Magellanic Cloud has revealed a very red (H-K = 2.1, K-L-prime = 2.7) compact object. The location, brightness, color and 2.1-2.4 micron spectrum of this source suggest that it is very young, and similar to the galactic infrared protostars. This is the first identification of an infrared protostar in an external galaxy. Its discovery provides direct evidence of current star formation in the Large Magellanic Cloud, and suggests that regions of star formation in external galaxies will appear similar to those in the Milky Way.

Gatley, I.↗
NASA NTRS1983

The exciting stars of Herbig-Haro objects

Accurate astrometry and infrared photometry are presented for 16 objects that are believed to represent the exciting stars for Herbig-Haro (HH) objects in their vicinities. These identifications are made on the bases of steeply rising energy distributions, proper motions of HH objects, alignment of sources with HH objects, or far-infrared emission. Exciting stars for the following HH objects are newly discovered or recognized: HH 17; HH 31; HH 32; HH 33 and 40; HH 34; HH 38 and 43; HH group 14 in NGC 2264; RNO 40; RNO 43; and GGD 33a, 33b, and 35. Geometrical alignments of some sources with HH objects support the view that young stars are capable of channeling kinetic energy into small solid angles, as does the fact that some sources are slightly displaced from the apices of fan nebulae (HH 17, R Mon, Haro 6-10). These exciting stars span a wide range of bolometric luminosity, although all are likely to be very young.

Cohen, M.↗
NASA NTRS1983

A survey by HEAO 1 of clusters of galaxies. III - The complete Abell catalog

A catalog of 128 X-ray emitting clusters, including the Virgo Cluster, is presented. Ninety-one of these are new identifications. The catalog was obtained by searching the HEAO 1 survey observations for coincidences of X-ray sources with Abell clusters. The distribution of these sources in the sky has been examined in search of associations with other Abell clusters, with a null result. The X-ray luminosity has been correlated with cluster richness, but no association with Bautz-Morgan class has been found. The cluster luminosity function has been evaluated, and using this function the contribution of clusters to the diffuse X-ray background radiation has been estimated. It amounts to less than 15% at 2 keV and 3% at 6 keV.

Johnson, M. W.↗
NASA NTRS1990

Infrared images of merging galaxies

Infrared imaging of interacting galaxies is especially interesting because their optical appearance is often so chaotic due to extinction by dust and emission from star formation regions, that it is impossible to locate the nuclei or determine the true stellar distribution. However, at near-infrared wavelengths extinction is considerably reduced, and most of the flux from galaxies originates from red giant stars that comprise the dominant stellar component by mass. Thus near infrared images offer the opportunity to study directly components of galactic structure which are otherwise inaccessible. Such images may ultimately provide the framework in which to understand the activity taking place in many of the mergers with high Infrared Astronomy Satellite (IRAS) luminosities. Infrared images have been useful in identifying double structures in the nuclei of interacting galaxies which have not even been hinted at by optical observations. A striking example of this is given by the K images of Arp 220. Graham et al. (1990) have used high resolution imaging to show that it has a double nucleus coincident with the radio sources in the middle of the dust lane. The results suggest that caution should be applied in the identification of optical bright spots as multiple nuclei in the absence of other evidence. They also illustrate the advantages of using infrared imaging to study the underlying structure in merging galaxies. The authors have begun a program to take near infrared images of galaxies which are believed to be mergers of disk galaxies because they have tidal tails and filaments. In many of these the merger is thought to have induced exceptionally luminous infrared emission (cf. Joseph and Wright 1985, Sanders et al. 1988). Although the optical images of the galaxies show spectacular dust lanes and filaments, the K images all have a very smooth distribution of light with an apparently single nucleus.

Wright, G. S.↗
NASA NTRS2006

Herschel and the Molecular Universe

Over the next decade, space-based missions will open up the universe to high spatial and spectral resolution studies at infrared and submillimeter wavelengths. This will allow us to study, in much greater detail, the composition and the origin and evolution of molecules in space. Moreover, molecular transitions in these spectral ranges provide a sensitive probe of the dynamics and the physical and chemical conditions in a wide range of objects at scales ranging from budding planetary systems to galactic and extragalactic sizes. Hence, these missions provide us with the tools to study key astrophysical and astrochemical processes involved in the formation and evolution of planets, stars, and galaxies. These new missions can be expected to lead to the detection of many thousands of new spectral features. Identification, analysis and interpretation of these features in terms of the physical and chemical characteristics of the astronomical sources will require detailed astronomical modeling tools supported by laboratory measurements and theoretical studies of chemical reactions and collisional excitation rates on species of astrophysical relevance. These data will have to be made easily accessible to the scientific community through web-based data archives. In this paper, we will review the Herschel mission and its expected impact on our understanding of the molecular universe.

Tielens, A. G. G. M.↗
NASA NTRS2006

The Swift/BAT Hard X-Ray Survey

The BAT instrument on Swift is a wide field (70 deg. '100 deg.) coded aperture instrument with a CdZnTe detector array sensitive to energies of 14-200 keV. Each day, the BAT survey typically covers 60% of the sky to a detection limit of 30 millicrab. BAT makes hard X-ray light curves of similar sensitivity and coverage to the X-ray light curves from XTE/ASM, but in an energy range where sources show remarkably different behavior. Integrating the BAT data produces an all sky map with a source detection limit at 15 months of a few 10(exp -11) ergs per square centimeter per second, depending on the exposure. This is the first uniform all-sky survey at energies high enough to be unaffected by absorption since HEAO 1 in 1977-8. BAT has detected greater than 200 AGN and greater than 180 galactic sources. At high galactic latitudes, the BAT sources are usually easy to identify, but many are heavily absorbed and there are a few quite surprising identifications. The BAT selected galaxies can be used to calculate LogN/LogS and the luminosity function for AGN which are complete and free from common systematics. Several crucial parameters for understanding the cosmic hard x-ray background are now determined.

Tueller, Jack↗
DOE OSTI2016

Identification of two mechanisms for current production in a biharmonic flashing electron ratchet

Ratchets rectify the motion of randomly moving particles, which are driven by isotropic sources of energy such as thermal and chemical energy, without applying a net, time-averaged force between source and drain. We describe the behavior of a damped electron, modeled by a quantum Lindblad master equation, within a flashing ratchet (a one-dimensional potential that oscillates between a flat surface and a periodic asymmetric surface). By investigating the complete space of all biharmonic potential shapes and a large range of oscillation frequencies, two modes of ratchet operation, differentiated by their oscillation frequencies (relative to the rate of electron relaxation), are identified. Slow-oscillating, strong friction ratchets operate by a classical, overdamped mechanism. In fast-oscillating, weak friction ratchets, current is primarily produced when the frequency of the oscillating potential is resonant with the beating of the electron wave function in the potential well. The shape of the ratchet potential determines the direction of the current (and, in some cases, straightforwardly accounts for current reversals), but the maximum achievable current at any shape is controlled by the degree of friction applied to the electron.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
NASA NTRS2004

A Detection of the Same Hot Plasma in the Corona: During a CME and Later at Ulysses

We show direct evidence for the same very hot plasma being detected remotely from SOHO in the corona and subsequently, at Ulysses in the solar wind. This is, to our knowledge, the first time that such an unambiguous identification has been made in the case of hot plasma. This detection complements studies correlating other plasma and field properties observed to the properties measured at the source in the corona. This observation takes advantage of a SOHO-Sun-Ulysses quadrature, during which the Sun-Ulysses included angle is $90^\circ$ and it is possible to observe with Ulysses instruments the same plasma that has previously been remotely observed with SOHO instruments in the corona on the limb of the Sun. The identification builds on an existing base of separate SOHO and interplanetary detections of hot plasma. SOHO/UVCS has found evidence for very hot coronal plasma in current sheets in the aftermath of CMEs in the [Fe XVIII] $\lambda$ \AA\ line, implying a temperature on the order of $6\times 10(exp 6)$ K. This temperature is unusually high even for active regions, but is compatible with the high temperature predicted in current sheets. In the solar wind, ACE data from early 1998 to middle 2000 revealed high frozen-in Fe charge state in many cases to be present in interplanetary plasma.

Suess, S. T.↗
DOE OSTI2016

ALMA spectroscopic survey in the Hubble Ultra Deep Field: survey description

We present the rationale for and the observational description of ASPECS: the ALMA SPECtroscopic Survey in the Hubble Ultra-Deep Field (UDF), the cosmological deep field that has the deepest multi-wavelength data available. Our overarching goal is to obtain an unbiased census of molecular gas and dust continuum emission in high-redshift (z > 0.5) galaxies. The ∼1′ region covered within the UDF was chosen to overlap with the deepest available imaging from the Hubble Space Telescope. Our ALMA observations consist of full frequency scans in band 3 (84–115 GHz) and band 6 (212–272 GHz) at approximately uniform line sensitivity (L{sub CO}{sup ′} ∼ 2 × 10{sup 9} K km s{sup −1} pc{sup 2}), and continuum noise levels of 3.8 μJy beam{sup −1} and 12.7 μJy beam{sup −1}, respectively. The molecular surveys cover the different rotational transitions of the CO molecule, leading to essentially full redshift coverage. The [C ii] emission line is also covered at redshifts 6.0<z<8.0. We present a customized algorithm to identify line candidates in the molecular line scans and quantify our ability to recover artificial sources from our data. Based on whether multiple CO lines are detected, and whether optical spectroscopic redshifts as well as optical counterparts exist, we constrain the most likely line identification. We report 10 (11) CO line candidates in the 3 mm (1 mm) band, and our statistical analysis shows that <4 of these (in each band) are likely spurious. Less than one-third of the total CO flux in the low-J CO line candidates are from sources that are not associated with an optical/NIR counterpart. We also present continuum maps of both the band 3 and band 6 observations. The data presented here form the basis of a number of dedicated studies that are presented in subsequent papers.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2023

Molecular identification of wines using in situ liquid SIMS and PCA analysis

Composition analysis in wine is gaining increasing attention because it can provide information about the wine quality, source, and nutrition. In this work, in situ liquid secondary ion mass spectrometry (SIMS) was applied to 14 representative wines, including six wines manufactured by a manufacturer in Washington State, United States, four Cabernet Sauvignon wines, and four Chardonnay wines from other different manufacturers and locations. In situ liquid SIMS has the unique advantage of simultaneously examining both organic and inorganic compositions from liquid samples. Principal component analysis (PCA) of SIMS spectra showed that red and white wines can be clearly differentiated according to their aromatic and oxygen-contained organic species. Furthermore, the identities of different wines, especially the same variety of wines, can be enforced with a combination of both organic and inorganic species. Meanwhile, in situ liquid SIMS is sample-friendly, so liquid samples can be directly analyzed without any prior sample dilution or separation. Taken together, we demonstrate the great potential of in situ liquid SIMS in applications related to the molecular investigation of various liquid samples in food science.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Quantum Chemistry Calculations for Metabolomics

A primary goal of metabolomics and exposomics studies is to fully characterize the small molecule composition of complex biological and environmental samples. However, despite advances in analytical technologies over the past two decades, the majority of small molecules in complex samples are not readily identifiable due to the immense structural and chemical diversi-ty present within the metabolome and exposome. Current gold-standard identification methods rely on reference libraries built using authentic chemical materials (“standards”), which are not available for most molecules. Computational quantum chemis-try methods, which can be used to calculate chemical properties that are then measured by analytical platforms, offer an alter-native route for building reference libraries, i.e., in silico libraries for “standards-free” identification. In this review, we cover the major roadblocks currently facing metabolomics and discuss applications where quantum chemistry calculations offer a solu-tion. Several successful examples for nuclear magnetic resonance spectroscopy, ion mobility spectrometry, infrared spectros-copy, and mass spectrometry methods are reviewed. Finally, we consider current best practices, sources of error, and provide an outlook for quantum chemistry calculations in metabolomics and exposomics studies. We expect this review will inspire researchers in the field of small molecule identification to accelerate adoption of in silico methods for generation of reference libraries and to add quantum chemistry calculations as another tool at their disposal to characterize complex samples.

Metabolism↗